xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/tree.c (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /* Language-independent node constructors for parse phase of GNU compiler.
2    Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3    1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4    Free Software Foundation, Inc.
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12 
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
16 for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3.  If not see
20 <http://www.gnu.org/licenses/>.  */
21 
22 /* This file contains the low level primitives for operating on tree nodes,
23    including allocation, list operations, interning of identifiers,
24    construction of data type nodes and statement nodes,
25    and construction of type conversion nodes.  It also contains
26    tables index by tree code that describe how to take apart
27    nodes of that code.
28 
29    It is intended to be language-independent, but occasionally
30    calls language-dependent routines defined (for C) in typecheck.c.  */
31 
32 #include "config.h"
33 #include "system.h"
34 #include "coretypes.h"
35 #include "tm.h"
36 #include "flags.h"
37 #include "tree.h"
38 #include "real.h"
39 #include "tm_p.h"
40 #include "function.h"
41 #include "obstack.h"
42 #include "toplev.h"
43 #include "ggc.h"
44 #include "hashtab.h"
45 #include "output.h"
46 #include "target.h"
47 #include "langhooks.h"
48 #include "tree-inline.h"
49 #include "tree-iterator.h"
50 #include "basic-block.h"
51 #include "tree-flow.h"
52 #include "params.h"
53 #include "pointer-set.h"
54 #include "fixed-value.h"
55 #include "tree-pass.h"
56 #include "langhooks-def.h"
57 #include "diagnostic.h"
58 #include "cgraph.h"
59 #include "timevar.h"
60 #include "except.h"
61 #include "debug.h"
62 #include "intl.h"
63 
64 /* Tree code classes.  */
65 
66 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) TYPE,
67 #define END_OF_BASE_TREE_CODES tcc_exceptional,
68 
69 const enum tree_code_class tree_code_type[] = {
70 #include "all-tree.def"
71 };
72 
73 #undef DEFTREECODE
74 #undef END_OF_BASE_TREE_CODES
75 
76 /* Table indexed by tree code giving number of expression
77    operands beyond the fixed part of the node structure.
78    Not used for types or decls.  */
79 
80 #define DEFTREECODE(SYM, NAME, TYPE, LENGTH) LENGTH,
81 #define END_OF_BASE_TREE_CODES 0,
82 
83 const unsigned char tree_code_length[] = {
84 #include "all-tree.def"
85 };
86 
87 #undef DEFTREECODE
88 #undef END_OF_BASE_TREE_CODES
89 
90 /* Names of tree components.
91    Used for printing out the tree and error messages.  */
92 #define DEFTREECODE(SYM, NAME, TYPE, LEN) NAME,
93 #define END_OF_BASE_TREE_CODES "@dummy",
94 
95 const char *const tree_code_name[] = {
96 #include "all-tree.def"
97 };
98 
99 #undef DEFTREECODE
100 #undef END_OF_BASE_TREE_CODES
101 
102 /* Each tree code class has an associated string representation.
103    These must correspond to the tree_code_class entries.  */
104 
105 const char *const tree_code_class_strings[] =
106 {
107   "exceptional",
108   "constant",
109   "type",
110   "declaration",
111   "reference",
112   "comparison",
113   "unary",
114   "binary",
115   "statement",
116   "vl_exp",
117   "expression"
118 };
119 
120 /* obstack.[ch] explicitly declined to prototype this.  */
121 extern int _obstack_allocated_p (struct obstack *h, void *obj);
122 
123 #ifdef GATHER_STATISTICS
124 /* Statistics-gathering stuff.  */
125 
126 int tree_node_counts[(int) all_kinds];
127 int tree_node_sizes[(int) all_kinds];
128 
129 /* Keep in sync with tree.h:enum tree_node_kind.  */
130 static const char * const tree_node_kind_names[] = {
131   "decls",
132   "types",
133   "blocks",
134   "stmts",
135   "refs",
136   "exprs",
137   "constants",
138   "identifiers",
139   "perm_tree_lists",
140   "temp_tree_lists",
141   "vecs",
142   "binfos",
143   "ssa names",
144   "constructors",
145   "random kinds",
146   "lang_decl kinds",
147   "lang_type kinds",
148   "omp clauses",
149 };
150 #endif /* GATHER_STATISTICS */
151 
152 /* Unique id for next decl created.  */
153 static GTY(()) int next_decl_uid;
154 /* Unique id for next type created.  */
155 static GTY(()) int next_type_uid = 1;
156 /* Unique id for next debug decl created.  Use negative numbers,
157    to catch erroneous uses.  */
158 static GTY(()) int next_debug_decl_uid;
159 
160 /* Since we cannot rehash a type after it is in the table, we have to
161    keep the hash code.  */
162 
163 struct GTY(()) type_hash {
164   unsigned long hash;
165   tree type;
166 };
167 
168 /* Initial size of the hash table (rounded to next prime).  */
169 #define TYPE_HASH_INITIAL_SIZE 1000
170 
171 /* Now here is the hash table.  When recording a type, it is added to
172    the slot whose index is the hash code.  Note that the hash table is
173    used for several kinds of types (function types, array types and
174    array index range types, for now).  While all these live in the
175    same table, they are completely independent, and the hash code is
176    computed differently for each of these.  */
177 
178 static GTY ((if_marked ("type_hash_marked_p"), param_is (struct type_hash)))
179      htab_t type_hash_table;
180 
181 /* Hash table and temporary node for larger integer const values.  */
182 static GTY (()) tree int_cst_node;
183 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
184      htab_t int_cst_hash_table;
185 
186 /* Hash table for optimization flags and target option flags.  Use the same
187    hash table for both sets of options.  Nodes for building the current
188    optimization and target option nodes.  The assumption is most of the time
189    the options created will already be in the hash table, so we avoid
190    allocating and freeing up a node repeatably.  */
191 static GTY (()) tree cl_optimization_node;
192 static GTY (()) tree cl_target_option_node;
193 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
194      htab_t cl_option_hash_table;
195 
196 /* General tree->tree mapping  structure for use in hash tables.  */
197 
198 
199 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
200      htab_t debug_expr_for_decl;
201 
202 static GTY ((if_marked ("tree_map_marked_p"), param_is (struct tree_map)))
203      htab_t value_expr_for_decl;
204 
205 static GTY ((if_marked ("tree_priority_map_marked_p"),
206 	     param_is (struct tree_priority_map)))
207   htab_t init_priority_for_decl;
208 
209 static void set_type_quals (tree, int);
210 static int type_hash_eq (const void *, const void *);
211 static hashval_t type_hash_hash (const void *);
212 static hashval_t int_cst_hash_hash (const void *);
213 static int int_cst_hash_eq (const void *, const void *);
214 static hashval_t cl_option_hash_hash (const void *);
215 static int cl_option_hash_eq (const void *, const void *);
216 static void print_type_hash_statistics (void);
217 static void print_debug_expr_statistics (void);
218 static void print_value_expr_statistics (void);
219 static int type_hash_marked_p (const void *);
220 static unsigned int type_hash_list (const_tree, hashval_t);
221 static unsigned int attribute_hash_list (const_tree, hashval_t);
222 
223 tree global_trees[TI_MAX];
224 tree integer_types[itk_none];
225 
226 unsigned char tree_contains_struct[MAX_TREE_CODES][64];
227 
228 /* Number of operands for each OpenMP clause.  */
229 unsigned const char omp_clause_num_ops[] =
230 {
231   0, /* OMP_CLAUSE_ERROR  */
232   1, /* OMP_CLAUSE_PRIVATE  */
233   1, /* OMP_CLAUSE_SHARED  */
234   1, /* OMP_CLAUSE_FIRSTPRIVATE  */
235   2, /* OMP_CLAUSE_LASTPRIVATE  */
236   4, /* OMP_CLAUSE_REDUCTION  */
237   1, /* OMP_CLAUSE_COPYIN  */
238   1, /* OMP_CLAUSE_COPYPRIVATE  */
239   1, /* OMP_CLAUSE_IF  */
240   1, /* OMP_CLAUSE_NUM_THREADS  */
241   1, /* OMP_CLAUSE_SCHEDULE  */
242   0, /* OMP_CLAUSE_NOWAIT  */
243   0, /* OMP_CLAUSE_ORDERED  */
244   0, /* OMP_CLAUSE_DEFAULT  */
245   3, /* OMP_CLAUSE_COLLAPSE  */
246   0  /* OMP_CLAUSE_UNTIED   */
247 };
248 
249 const char * const omp_clause_code_name[] =
250 {
251   "error_clause",
252   "private",
253   "shared",
254   "firstprivate",
255   "lastprivate",
256   "reduction",
257   "copyin",
258   "copyprivate",
259   "if",
260   "num_threads",
261   "schedule",
262   "nowait",
263   "ordered",
264   "default",
265   "collapse",
266   "untied"
267 };
268 
269 
270 /* Return the tree node structure used by tree code CODE.  */
271 
272 static inline enum tree_node_structure_enum
273 tree_node_structure_for_code (enum tree_code code)
274 {
275   switch (TREE_CODE_CLASS (code))
276     {
277     case tcc_declaration:
278       {
279 	switch (code)
280 	  {
281 	  case FIELD_DECL:
282 	    return TS_FIELD_DECL;
283 	  case PARM_DECL:
284 	    return TS_PARM_DECL;
285 	  case VAR_DECL:
286 	    return TS_VAR_DECL;
287 	  case LABEL_DECL:
288 	    return TS_LABEL_DECL;
289 	  case RESULT_DECL:
290 	    return TS_RESULT_DECL;
291 	  case DEBUG_EXPR_DECL:
292 	    return TS_DECL_WRTL;
293 	  case CONST_DECL:
294 	    return TS_CONST_DECL;
295 	  case TYPE_DECL:
296 	    return TS_TYPE_DECL;
297 	  case FUNCTION_DECL:
298 	    return TS_FUNCTION_DECL;
299 	  default:
300 	    return TS_DECL_NON_COMMON;
301 	  }
302       }
303     case tcc_type:
304       return TS_TYPE;
305     case tcc_reference:
306     case tcc_comparison:
307     case tcc_unary:
308     case tcc_binary:
309     case tcc_expression:
310     case tcc_statement:
311     case tcc_vl_exp:
312       return TS_EXP;
313     default:  /* tcc_constant and tcc_exceptional */
314       break;
315     }
316   switch (code)
317     {
318       /* tcc_constant cases.  */
319     case INTEGER_CST:		return TS_INT_CST;
320     case REAL_CST:		return TS_REAL_CST;
321     case FIXED_CST:		return TS_FIXED_CST;
322     case COMPLEX_CST:		return TS_COMPLEX;
323     case VECTOR_CST:		return TS_VECTOR;
324     case STRING_CST:		return TS_STRING;
325       /* tcc_exceptional cases.  */
326     case ERROR_MARK:		return TS_COMMON;
327     case IDENTIFIER_NODE:	return TS_IDENTIFIER;
328     case TREE_LIST:		return TS_LIST;
329     case TREE_VEC:		return TS_VEC;
330     case SSA_NAME:		return TS_SSA_NAME;
331     case PLACEHOLDER_EXPR:	return TS_COMMON;
332     case STATEMENT_LIST:	return TS_STATEMENT_LIST;
333     case BLOCK:			return TS_BLOCK;
334     case CONSTRUCTOR:		return TS_CONSTRUCTOR;
335     case TREE_BINFO:		return TS_BINFO;
336     case OMP_CLAUSE:		return TS_OMP_CLAUSE;
337     case OPTIMIZATION_NODE:	return TS_OPTIMIZATION;
338     case TARGET_OPTION_NODE:	return TS_TARGET_OPTION;
339 
340     default:
341       gcc_unreachable ();
342     }
343 }
344 
345 
346 /* Initialize tree_contains_struct to describe the hierarchy of tree
347    nodes.  */
348 
349 static void
350 initialize_tree_contains_struct (void)
351 {
352   unsigned i;
353 
354 #define MARK_TS_BASE(C)					\
355   do {							\
356     tree_contains_struct[C][TS_BASE] = 1;		\
357   } while (0)
358 
359 #define MARK_TS_COMMON(C)				\
360   do {							\
361     MARK_TS_BASE (C);					\
362     tree_contains_struct[C][TS_COMMON] = 1;		\
363   } while (0)
364 
365 #define MARK_TS_DECL_MINIMAL(C)				\
366   do {							\
367     MARK_TS_COMMON (C);					\
368     tree_contains_struct[C][TS_DECL_MINIMAL] = 1;	\
369   } while (0)
370 
371 #define MARK_TS_DECL_COMMON(C)				\
372   do {							\
373     MARK_TS_DECL_MINIMAL (C);				\
374     tree_contains_struct[C][TS_DECL_COMMON] = 1;	\
375   } while (0)
376 
377 #define MARK_TS_DECL_WRTL(C)				\
378   do {							\
379     MARK_TS_DECL_COMMON (C);				\
380     tree_contains_struct[C][TS_DECL_WRTL] = 1;		\
381   } while (0)
382 
383 #define MARK_TS_DECL_WITH_VIS(C)			\
384   do {							\
385     MARK_TS_DECL_WRTL (C);				\
386     tree_contains_struct[C][TS_DECL_WITH_VIS] = 1;	\
387   } while (0)
388 
389 #define MARK_TS_DECL_NON_COMMON(C)			\
390   do {							\
391     MARK_TS_DECL_WITH_VIS (C);				\
392     tree_contains_struct[C][TS_DECL_NON_COMMON] = 1;	\
393   } while (0)
394 
395   for (i = ERROR_MARK; i < LAST_AND_UNUSED_TREE_CODE; i++)
396     {
397       enum tree_code code;
398       enum tree_node_structure_enum ts_code;
399 
400       code = (enum tree_code) i;
401       ts_code = tree_node_structure_for_code (code);
402 
403       /* Mark the TS structure itself.  */
404       tree_contains_struct[code][ts_code] = 1;
405 
406       /* Mark all the structures that TS is derived from.  */
407       switch (ts_code)
408 	{
409 	case TS_COMMON:
410 	  MARK_TS_BASE (code);
411 	  break;
412 
413 	case TS_INT_CST:
414 	case TS_REAL_CST:
415 	case TS_FIXED_CST:
416 	case TS_VECTOR:
417 	case TS_STRING:
418 	case TS_COMPLEX:
419 	case TS_IDENTIFIER:
420 	case TS_DECL_MINIMAL:
421 	case TS_TYPE:
422 	case TS_LIST:
423 	case TS_VEC:
424 	case TS_EXP:
425 	case TS_SSA_NAME:
426 	case TS_BLOCK:
427 	case TS_BINFO:
428 	case TS_STATEMENT_LIST:
429 	case TS_CONSTRUCTOR:
430 	case TS_OMP_CLAUSE:
431 	case TS_OPTIMIZATION:
432 	case TS_TARGET_OPTION:
433 	  MARK_TS_COMMON (code);
434 	  break;
435 
436 	case TS_DECL_COMMON:
437 	  MARK_TS_DECL_MINIMAL (code);
438 	  break;
439 
440 	case TS_DECL_WRTL:
441 	  MARK_TS_DECL_COMMON (code);
442 	  break;
443 
444 	case TS_DECL_NON_COMMON:
445 	  MARK_TS_DECL_WITH_VIS (code);
446 	  break;
447 
448 	case TS_DECL_WITH_VIS:
449 	case TS_PARM_DECL:
450 	case TS_LABEL_DECL:
451 	case TS_RESULT_DECL:
452 	case TS_CONST_DECL:
453 	  MARK_TS_DECL_WRTL (code);
454 	  break;
455 
456 	case TS_FIELD_DECL:
457 	  MARK_TS_DECL_COMMON (code);
458 	  break;
459 
460 	case TS_VAR_DECL:
461 	  MARK_TS_DECL_WITH_VIS (code);
462 	  break;
463 
464 	case TS_TYPE_DECL:
465 	case TS_FUNCTION_DECL:
466 	  MARK_TS_DECL_NON_COMMON (code);
467 	  break;
468 
469 	default:
470 	  gcc_unreachable ();
471 	}
472     }
473 
474   /* Basic consistency checks for attributes used in fold.  */
475   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_NON_COMMON]);
476   gcc_assert (tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_NON_COMMON]);
477   gcc_assert (tree_contains_struct[TYPE_DECL][TS_DECL_NON_COMMON]);
478   gcc_assert (tree_contains_struct[CONST_DECL][TS_DECL_COMMON]);
479   gcc_assert (tree_contains_struct[VAR_DECL][TS_DECL_COMMON]);
480   gcc_assert (tree_contains_struct[PARM_DECL][TS_DECL_COMMON]);
481   gcc_assert (tree_contains_struct[RESULT_DECL][TS_DECL_COMMON]);
482   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_COMMON]);
483   gcc_assert (tree_contains_struct[TYPE_DECL][TS_DECL_COMMON]);
484   gcc_assert (tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_COMMON]);
485   gcc_assert (tree_contains_struct[LABEL_DECL][TS_DECL_COMMON]);
486   gcc_assert (tree_contains_struct[FIELD_DECL][TS_DECL_COMMON]);
487   gcc_assert (tree_contains_struct[CONST_DECL][TS_DECL_WRTL]);
488   gcc_assert (tree_contains_struct[VAR_DECL][TS_DECL_WRTL]);
489   gcc_assert (tree_contains_struct[PARM_DECL][TS_DECL_WRTL]);
490   gcc_assert (tree_contains_struct[RESULT_DECL][TS_DECL_WRTL]);
491   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_WRTL]);
492   gcc_assert (tree_contains_struct[LABEL_DECL][TS_DECL_WRTL]);
493   gcc_assert (tree_contains_struct[CONST_DECL][TS_DECL_MINIMAL]);
494   gcc_assert (tree_contains_struct[VAR_DECL][TS_DECL_MINIMAL]);
495   gcc_assert (tree_contains_struct[PARM_DECL][TS_DECL_MINIMAL]);
496   gcc_assert (tree_contains_struct[RESULT_DECL][TS_DECL_MINIMAL]);
497   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_MINIMAL]);
498   gcc_assert (tree_contains_struct[TYPE_DECL][TS_DECL_MINIMAL]);
499   gcc_assert (tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_MINIMAL]);
500   gcc_assert (tree_contains_struct[LABEL_DECL][TS_DECL_MINIMAL]);
501   gcc_assert (tree_contains_struct[FIELD_DECL][TS_DECL_MINIMAL]);
502   gcc_assert (tree_contains_struct[VAR_DECL][TS_DECL_WITH_VIS]);
503   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_DECL_WITH_VIS]);
504   gcc_assert (tree_contains_struct[TYPE_DECL][TS_DECL_WITH_VIS]);
505   gcc_assert (tree_contains_struct[TRANSLATION_UNIT_DECL][TS_DECL_WITH_VIS]);
506   gcc_assert (tree_contains_struct[VAR_DECL][TS_VAR_DECL]);
507   gcc_assert (tree_contains_struct[FIELD_DECL][TS_FIELD_DECL]);
508   gcc_assert (tree_contains_struct[PARM_DECL][TS_PARM_DECL]);
509   gcc_assert (tree_contains_struct[LABEL_DECL][TS_LABEL_DECL]);
510   gcc_assert (tree_contains_struct[RESULT_DECL][TS_RESULT_DECL]);
511   gcc_assert (tree_contains_struct[CONST_DECL][TS_CONST_DECL]);
512   gcc_assert (tree_contains_struct[TYPE_DECL][TS_TYPE_DECL]);
513   gcc_assert (tree_contains_struct[FUNCTION_DECL][TS_FUNCTION_DECL]);
514   gcc_assert (tree_contains_struct[IMPORTED_DECL][TS_DECL_MINIMAL]);
515   gcc_assert (tree_contains_struct[IMPORTED_DECL][TS_DECL_COMMON]);
516 
517 #undef MARK_TS_BASE
518 #undef MARK_TS_COMMON
519 #undef MARK_TS_DECL_MINIMAL
520 #undef MARK_TS_DECL_COMMON
521 #undef MARK_TS_DECL_WRTL
522 #undef MARK_TS_DECL_WITH_VIS
523 #undef MARK_TS_DECL_NON_COMMON
524 }
525 
526 
527 /* Init tree.c.  */
528 
529 void
530 init_ttree (void)
531 {
532   /* Initialize the hash table of types.  */
533   type_hash_table = htab_create_ggc (TYPE_HASH_INITIAL_SIZE, type_hash_hash,
534 				     type_hash_eq, 0);
535 
536   debug_expr_for_decl = htab_create_ggc (512, tree_map_hash,
537 					 tree_map_eq, 0);
538 
539   value_expr_for_decl = htab_create_ggc (512, tree_map_hash,
540 					 tree_map_eq, 0);
541   init_priority_for_decl = htab_create_ggc (512, tree_priority_map_hash,
542 					    tree_priority_map_eq, 0);
543 
544   int_cst_hash_table = htab_create_ggc (1024, int_cst_hash_hash,
545 					int_cst_hash_eq, NULL);
546 
547   int_cst_node = make_node (INTEGER_CST);
548 
549   cl_option_hash_table = htab_create_ggc (64, cl_option_hash_hash,
550 					  cl_option_hash_eq, NULL);
551 
552   cl_optimization_node = make_node (OPTIMIZATION_NODE);
553   cl_target_option_node = make_node (TARGET_OPTION_NODE);
554 
555   /* Initialize the tree_contains_struct array.  */
556   initialize_tree_contains_struct ();
557   lang_hooks.init_ts ();
558 }
559 
560 
561 /* The name of the object as the assembler will see it (but before any
562    translations made by ASM_OUTPUT_LABELREF).  Often this is the same
563    as DECL_NAME.  It is an IDENTIFIER_NODE.  */
564 tree
565 decl_assembler_name (tree decl)
566 {
567   if (!DECL_ASSEMBLER_NAME_SET_P (decl))
568     lang_hooks.set_decl_assembler_name (decl);
569   return DECL_WITH_VIS_CHECK (decl)->decl_with_vis.assembler_name;
570 }
571 
572 /* Compare ASMNAME with the DECL_ASSEMBLER_NAME of DECL.  */
573 
574 bool
575 decl_assembler_name_equal (tree decl, const_tree asmname)
576 {
577   tree decl_asmname = DECL_ASSEMBLER_NAME (decl);
578   const char *decl_str;
579   const char *asmname_str;
580   bool test = false;
581 
582   if (decl_asmname == asmname)
583     return true;
584 
585   decl_str = IDENTIFIER_POINTER (decl_asmname);
586   asmname_str = IDENTIFIER_POINTER (asmname);
587 
588 
589   /* If the target assembler name was set by the user, things are trickier.
590      We have a leading '*' to begin with.  After that, it's arguable what
591      is the correct thing to do with -fleading-underscore.  Arguably, we've
592      historically been doing the wrong thing in assemble_alias by always
593      printing the leading underscore.  Since we're not changing that, make
594      sure user_label_prefix follows the '*' before matching.  */
595   if (decl_str[0] == '*')
596     {
597       size_t ulp_len = strlen (user_label_prefix);
598 
599       decl_str ++;
600 
601       if (ulp_len == 0)
602 	test = true;
603       else if (strncmp (decl_str, user_label_prefix, ulp_len) == 0)
604 	decl_str += ulp_len, test=true;
605       else
606 	decl_str --;
607     }
608   if (asmname_str[0] == '*')
609     {
610       size_t ulp_len = strlen (user_label_prefix);
611 
612       asmname_str ++;
613 
614       if (ulp_len == 0)
615 	test = true;
616       else if (strncmp (asmname_str, user_label_prefix, ulp_len) == 0)
617 	asmname_str += ulp_len, test=true;
618       else
619 	asmname_str --;
620     }
621 
622   if (!test)
623     return false;
624   return strcmp (decl_str, asmname_str) == 0;
625 }
626 
627 /* Hash asmnames ignoring the user specified marks.  */
628 
629 hashval_t
630 decl_assembler_name_hash (const_tree asmname)
631 {
632   if (IDENTIFIER_POINTER (asmname)[0] == '*')
633     {
634       const char *decl_str = IDENTIFIER_POINTER (asmname) + 1;
635       size_t ulp_len = strlen (user_label_prefix);
636 
637       if (ulp_len == 0)
638 	;
639       else if (strncmp (decl_str, user_label_prefix, ulp_len) == 0)
640 	decl_str += ulp_len;
641 
642       return htab_hash_string (decl_str);
643     }
644 
645   return htab_hash_string (IDENTIFIER_POINTER (asmname));
646 }
647 
648 /* Compute the number of bytes occupied by a tree with code CODE.
649    This function cannot be used for nodes that have variable sizes,
650    including TREE_VEC, STRING_CST, and CALL_EXPR.  */
651 size_t
652 tree_code_size (enum tree_code code)
653 {
654   switch (TREE_CODE_CLASS (code))
655     {
656     case tcc_declaration:  /* A decl node */
657       {
658 	switch (code)
659 	  {
660 	  case FIELD_DECL:
661 	    return sizeof (struct tree_field_decl);
662 	  case PARM_DECL:
663 	    return sizeof (struct tree_parm_decl);
664 	  case VAR_DECL:
665 	    return sizeof (struct tree_var_decl);
666 	  case LABEL_DECL:
667 	    return sizeof (struct tree_label_decl);
668 	  case RESULT_DECL:
669 	    return sizeof (struct tree_result_decl);
670 	  case CONST_DECL:
671 	    return sizeof (struct tree_const_decl);
672 	  case TYPE_DECL:
673 	    return sizeof (struct tree_type_decl);
674 	  case FUNCTION_DECL:
675 	    return sizeof (struct tree_function_decl);
676 	  case DEBUG_EXPR_DECL:
677 	    return sizeof (struct tree_decl_with_rtl);
678 	  default:
679 	    return sizeof (struct tree_decl_non_common);
680 	  }
681       }
682 
683     case tcc_type:  /* a type node */
684       return sizeof (struct tree_type);
685 
686     case tcc_reference:   /* a reference */
687     case tcc_expression:  /* an expression */
688     case tcc_statement:   /* an expression with side effects */
689     case tcc_comparison:  /* a comparison expression */
690     case tcc_unary:       /* a unary arithmetic expression */
691     case tcc_binary:      /* a binary arithmetic expression */
692       return (sizeof (struct tree_exp)
693 	      + (TREE_CODE_LENGTH (code) - 1) * sizeof (tree));
694 
695     case tcc_constant:  /* a constant */
696       switch (code)
697 	{
698 	case INTEGER_CST:	return sizeof (struct tree_int_cst);
699 	case REAL_CST:		return sizeof (struct tree_real_cst);
700 	case FIXED_CST:		return sizeof (struct tree_fixed_cst);
701 	case COMPLEX_CST:	return sizeof (struct tree_complex);
702 	case VECTOR_CST:	return sizeof (struct tree_vector);
703 	case STRING_CST:	gcc_unreachable ();
704 	default:
705 	  return lang_hooks.tree_size (code);
706 	}
707 
708     case tcc_exceptional:  /* something random, like an identifier.  */
709       switch (code)
710 	{
711 	case IDENTIFIER_NODE:	return lang_hooks.identifier_size;
712 	case TREE_LIST:		return sizeof (struct tree_list);
713 
714 	case ERROR_MARK:
715 	case PLACEHOLDER_EXPR:	return sizeof (struct tree_common);
716 
717 	case TREE_VEC:
718 	case OMP_CLAUSE:	gcc_unreachable ();
719 
720 	case SSA_NAME:		return sizeof (struct tree_ssa_name);
721 
722 	case STATEMENT_LIST:	return sizeof (struct tree_statement_list);
723 	case BLOCK:		return sizeof (struct tree_block);
724 	case CONSTRUCTOR:	return sizeof (struct tree_constructor);
725 	case OPTIMIZATION_NODE: return sizeof (struct tree_optimization_option);
726 	case TARGET_OPTION_NODE: return sizeof (struct tree_target_option);
727 
728 	default:
729 	  return lang_hooks.tree_size (code);
730 	}
731 
732     default:
733       gcc_unreachable ();
734     }
735 }
736 
737 /* Compute the number of bytes occupied by NODE.  This routine only
738    looks at TREE_CODE, except for those nodes that have variable sizes.  */
739 size_t
740 tree_size (const_tree node)
741 {
742   const enum tree_code code = TREE_CODE (node);
743   switch (code)
744     {
745     case TREE_BINFO:
746       return (offsetof (struct tree_binfo, base_binfos)
747 	      + VEC_embedded_size (tree, BINFO_N_BASE_BINFOS (node)));
748 
749     case TREE_VEC:
750       return (sizeof (struct tree_vec)
751 	      + (TREE_VEC_LENGTH (node) - 1) * sizeof (tree));
752 
753     case STRING_CST:
754       return TREE_STRING_LENGTH (node) + offsetof (struct tree_string, str) + 1;
755 
756     case OMP_CLAUSE:
757       return (sizeof (struct tree_omp_clause)
758 	      + (omp_clause_num_ops[OMP_CLAUSE_CODE (node)] - 1)
759 	        * sizeof (tree));
760 
761     default:
762       if (TREE_CODE_CLASS (code) == tcc_vl_exp)
763 	return (sizeof (struct tree_exp)
764 		+ (VL_EXP_OPERAND_LENGTH (node) - 1) * sizeof (tree));
765       else
766 	return tree_code_size (code);
767     }
768 }
769 
770 /* Return a newly allocated node of code CODE.  For decl and type
771    nodes, some other fields are initialized.  The rest of the node is
772    initialized to zero.  This function cannot be used for TREE_VEC or
773    OMP_CLAUSE nodes, which is enforced by asserts in tree_code_size.
774 
775    Achoo!  I got a code in the node.  */
776 
777 tree
778 make_node_stat (enum tree_code code MEM_STAT_DECL)
779 {
780   tree t;
781   enum tree_code_class type = TREE_CODE_CLASS (code);
782   size_t length = tree_code_size (code);
783 #ifdef GATHER_STATISTICS
784   tree_node_kind kind;
785 
786   switch (type)
787     {
788     case tcc_declaration:  /* A decl node */
789       kind = d_kind;
790       break;
791 
792     case tcc_type:  /* a type node */
793       kind = t_kind;
794       break;
795 
796     case tcc_statement:  /* an expression with side effects */
797       kind = s_kind;
798       break;
799 
800     case tcc_reference:  /* a reference */
801       kind = r_kind;
802       break;
803 
804     case tcc_expression:  /* an expression */
805     case tcc_comparison:  /* a comparison expression */
806     case tcc_unary:  /* a unary arithmetic expression */
807     case tcc_binary:  /* a binary arithmetic expression */
808       kind = e_kind;
809       break;
810 
811     case tcc_constant:  /* a constant */
812       kind = c_kind;
813       break;
814 
815     case tcc_exceptional:  /* something random, like an identifier.  */
816       switch (code)
817 	{
818 	case IDENTIFIER_NODE:
819 	  kind = id_kind;
820 	  break;
821 
822 	case TREE_VEC:
823 	  kind = vec_kind;
824 	  break;
825 
826 	case TREE_BINFO:
827 	  kind = binfo_kind;
828 	  break;
829 
830 	case SSA_NAME:
831 	  kind = ssa_name_kind;
832 	  break;
833 
834 	case BLOCK:
835 	  kind = b_kind;
836 	  break;
837 
838 	case CONSTRUCTOR:
839 	  kind = constr_kind;
840 	  break;
841 
842 	default:
843 	  kind = x_kind;
844 	  break;
845 	}
846       break;
847 
848     default:
849       gcc_unreachable ();
850     }
851 
852   tree_node_counts[(int) kind]++;
853   tree_node_sizes[(int) kind] += length;
854 #endif
855 
856   if (code == IDENTIFIER_NODE)
857     t = (tree) ggc_alloc_zone_pass_stat (length, &tree_id_zone);
858   else
859     t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
860 
861   memset (t, 0, length);
862 
863   TREE_SET_CODE (t, code);
864 
865   switch (type)
866     {
867     case tcc_statement:
868       TREE_SIDE_EFFECTS (t) = 1;
869       break;
870 
871     case tcc_declaration:
872       if (CODE_CONTAINS_STRUCT (code, TS_DECL_COMMON))
873 	{
874 	  if (code == FUNCTION_DECL)
875 	    {
876 	      DECL_ALIGN (t) = FUNCTION_BOUNDARY;
877 	      DECL_MODE (t) = FUNCTION_MODE;
878 	    }
879 	  else
880 	    DECL_ALIGN (t) = 1;
881 	}
882       DECL_SOURCE_LOCATION (t) = input_location;
883       if (TREE_CODE (t) == DEBUG_EXPR_DECL)
884 	DECL_UID (t) = --next_debug_decl_uid;
885       else
886 	DECL_UID (t) = next_decl_uid++;
887       if (TREE_CODE (t) == LABEL_DECL)
888 	LABEL_DECL_UID (t) = -1;
889 
890       break;
891 
892     case tcc_type:
893       TYPE_UID (t) = next_type_uid++;
894       TYPE_ALIGN (t) = BITS_PER_UNIT;
895       TYPE_USER_ALIGN (t) = 0;
896       TYPE_MAIN_VARIANT (t) = t;
897       TYPE_CANONICAL (t) = t;
898 
899       /* Default to no attributes for type, but let target change that.  */
900       TYPE_ATTRIBUTES (t) = NULL_TREE;
901       targetm.set_default_type_attributes (t);
902 
903       /* We have not yet computed the alias set for this type.  */
904       TYPE_ALIAS_SET (t) = -1;
905       break;
906 
907     case tcc_constant:
908       TREE_CONSTANT (t) = 1;
909       break;
910 
911     case tcc_expression:
912       switch (code)
913 	{
914 	case INIT_EXPR:
915 	case MODIFY_EXPR:
916 	case VA_ARG_EXPR:
917 	case PREDECREMENT_EXPR:
918 	case PREINCREMENT_EXPR:
919 	case POSTDECREMENT_EXPR:
920 	case POSTINCREMENT_EXPR:
921 	  /* All of these have side-effects, no matter what their
922 	     operands are.  */
923 	  TREE_SIDE_EFFECTS (t) = 1;
924 	  break;
925 
926 	default:
927 	  break;
928 	}
929       break;
930 
931     default:
932       /* Other classes need no special treatment.  */
933       break;
934     }
935 
936   return t;
937 }
938 
939 /* Return a new node with the same contents as NODE except that its
940    TREE_CHAIN is zero and it has a fresh uid.  */
941 
942 tree
943 copy_node_stat (tree node MEM_STAT_DECL)
944 {
945   tree t;
946   enum tree_code code = TREE_CODE (node);
947   size_t length;
948 
949   gcc_assert (code != STATEMENT_LIST);
950 
951   length = tree_size (node);
952   t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
953   memcpy (t, node, length);
954 
955   TREE_CHAIN (t) = 0;
956   TREE_ASM_WRITTEN (t) = 0;
957   TREE_VISITED (t) = 0;
958   if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
959     *DECL_VAR_ANN_PTR (t) = 0;
960 
961   if (TREE_CODE_CLASS (code) == tcc_declaration)
962     {
963       if (code == DEBUG_EXPR_DECL)
964 	DECL_UID (t) = --next_debug_decl_uid;
965       else
966 	DECL_UID (t) = next_decl_uid++;
967       if ((TREE_CODE (node) == PARM_DECL || TREE_CODE (node) == VAR_DECL)
968 	  && DECL_HAS_VALUE_EXPR_P (node))
969 	{
970 	  SET_DECL_VALUE_EXPR (t, DECL_VALUE_EXPR (node));
971 	  DECL_HAS_VALUE_EXPR_P (t) = 1;
972 	}
973       if (TREE_CODE (node) == VAR_DECL && DECL_HAS_INIT_PRIORITY_P (node))
974 	{
975 	  SET_DECL_INIT_PRIORITY (t, DECL_INIT_PRIORITY (node));
976 	  DECL_HAS_INIT_PRIORITY_P (t) = 1;
977 	}
978     }
979   else if (TREE_CODE_CLASS (code) == tcc_type)
980     {
981       TYPE_UID (t) = next_type_uid++;
982       /* The following is so that the debug code for
983 	 the copy is different from the original type.
984 	 The two statements usually duplicate each other
985 	 (because they clear fields of the same union),
986 	 but the optimizer should catch that.  */
987       TYPE_SYMTAB_POINTER (t) = 0;
988       TYPE_SYMTAB_ADDRESS (t) = 0;
989 
990       /* Do not copy the values cache.  */
991       if (TYPE_CACHED_VALUES_P(t))
992 	{
993 	  TYPE_CACHED_VALUES_P (t) = 0;
994 	  TYPE_CACHED_VALUES (t) = NULL_TREE;
995 	}
996     }
997 
998   return t;
999 }
1000 
1001 /* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
1002    For example, this can copy a list made of TREE_LIST nodes.  */
1003 
1004 tree
1005 copy_list (tree list)
1006 {
1007   tree head;
1008   tree prev, next;
1009 
1010   if (list == 0)
1011     return 0;
1012 
1013   head = prev = copy_node (list);
1014   next = TREE_CHAIN (list);
1015   while (next)
1016     {
1017       TREE_CHAIN (prev) = copy_node (next);
1018       prev = TREE_CHAIN (prev);
1019       next = TREE_CHAIN (next);
1020     }
1021   return head;
1022 }
1023 
1024 
1025 /* Create an INT_CST node with a LOW value sign extended.  */
1026 
1027 tree
1028 build_int_cst (tree type, HOST_WIDE_INT low)
1029 {
1030   /* Support legacy code.  */
1031   if (!type)
1032     type = integer_type_node;
1033 
1034   return build_int_cst_wide (type, low, low < 0 ? -1 : 0);
1035 }
1036 
1037 /* Create an INT_CST node with a LOW value zero extended.  */
1038 
1039 tree
1040 build_int_cstu (tree type, unsigned HOST_WIDE_INT low)
1041 {
1042   return build_int_cst_wide (type, low, 0);
1043 }
1044 
1045 /* Create an INT_CST node with a LOW value in TYPE.  The value is sign extended
1046    if it is negative.  This function is similar to build_int_cst, but
1047    the extra bits outside of the type precision are cleared.  Constants
1048    with these extra bits may confuse the fold so that it detects overflows
1049    even in cases when they do not occur, and in general should be avoided.
1050    We cannot however make this a default behavior of build_int_cst without
1051    more intrusive changes, since there are parts of gcc that rely on the extra
1052    precision of the integer constants.  */
1053 
1054 tree
1055 build_int_cst_type (tree type, HOST_WIDE_INT low)
1056 {
1057   unsigned HOST_WIDE_INT low1;
1058   HOST_WIDE_INT hi;
1059 
1060   gcc_assert (type);
1061 
1062   fit_double_type (low, low < 0 ? -1 : 0, &low1, &hi, type);
1063 
1064   return build_int_cst_wide (type, low1, hi);
1065 }
1066 
1067 /* Create an INT_CST node of TYPE and value HI:LOW.  The value is truncated
1068    and sign extended according to the value range of TYPE.  */
1069 
1070 tree
1071 build_int_cst_wide_type (tree type,
1072 			 unsigned HOST_WIDE_INT low, HOST_WIDE_INT high)
1073 {
1074   fit_double_type (low, high, &low, &high, type);
1075   return build_int_cst_wide (type, low, high);
1076 }
1077 
1078 /* These are the hash table functions for the hash table of INTEGER_CST
1079    nodes of a sizetype.  */
1080 
1081 /* Return the hash code code X, an INTEGER_CST.  */
1082 
1083 static hashval_t
1084 int_cst_hash_hash (const void *x)
1085 {
1086   const_tree const t = (const_tree) x;
1087 
1088   return (TREE_INT_CST_HIGH (t) ^ TREE_INT_CST_LOW (t)
1089 	  ^ htab_hash_pointer (TREE_TYPE (t)));
1090 }
1091 
1092 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1093    is the same as that given by *Y, which is the same.  */
1094 
1095 static int
1096 int_cst_hash_eq (const void *x, const void *y)
1097 {
1098   const_tree const xt = (const_tree) x;
1099   const_tree const yt = (const_tree) y;
1100 
1101   return (TREE_TYPE (xt) == TREE_TYPE (yt)
1102 	  && TREE_INT_CST_HIGH (xt) == TREE_INT_CST_HIGH (yt)
1103 	  && TREE_INT_CST_LOW (xt) == TREE_INT_CST_LOW (yt));
1104 }
1105 
1106 /* Create an INT_CST node of TYPE and value HI:LOW.
1107    The returned node is always shared.  For small integers we use a
1108    per-type vector cache, for larger ones we use a single hash table.  */
1109 
1110 tree
1111 build_int_cst_wide (tree type, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
1112 {
1113   tree t;
1114   int ix = -1;
1115   int limit = 0;
1116 
1117   gcc_assert (type);
1118 
1119   switch (TREE_CODE (type))
1120     {
1121     case POINTER_TYPE:
1122     case REFERENCE_TYPE:
1123       /* Cache NULL pointer.  */
1124       if (!hi && !low)
1125 	{
1126 	  limit = 1;
1127 	  ix = 0;
1128 	}
1129       break;
1130 
1131     case BOOLEAN_TYPE:
1132       /* Cache false or true.  */
1133       limit = 2;
1134       if (!hi && low < 2)
1135 	ix = low;
1136       break;
1137 
1138     case INTEGER_TYPE:
1139     case OFFSET_TYPE:
1140       if (TYPE_UNSIGNED (type))
1141 	{
1142 	  /* Cache 0..N */
1143 	  limit = INTEGER_SHARE_LIMIT;
1144 	  if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
1145 	    ix = low;
1146 	}
1147       else
1148 	{
1149 	  /* Cache -1..N */
1150 	  limit = INTEGER_SHARE_LIMIT + 1;
1151 	  if (!hi && low < (unsigned HOST_WIDE_INT)INTEGER_SHARE_LIMIT)
1152 	    ix = low + 1;
1153 	  else if (hi == -1 && low == -(unsigned HOST_WIDE_INT)1)
1154 	    ix = 0;
1155 	}
1156       break;
1157 
1158     case ENUMERAL_TYPE:
1159       break;
1160 
1161     default:
1162       gcc_unreachable ();
1163     }
1164 
1165   if (ix >= 0)
1166     {
1167       /* Look for it in the type's vector of small shared ints.  */
1168       if (!TYPE_CACHED_VALUES_P (type))
1169 	{
1170 	  TYPE_CACHED_VALUES_P (type) = 1;
1171 	  TYPE_CACHED_VALUES (type) = make_tree_vec (limit);
1172 	}
1173 
1174       t = TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix);
1175       if (t)
1176 	{
1177 	  /* Make sure no one is clobbering the shared constant.  */
1178 	  gcc_assert (TREE_TYPE (t) == type);
1179 	  gcc_assert (TREE_INT_CST_LOW (t) == low);
1180 	  gcc_assert (TREE_INT_CST_HIGH (t) == hi);
1181 	}
1182       else
1183 	{
1184 	  /* Create a new shared int.  */
1185 	  t = make_node (INTEGER_CST);
1186 
1187 	  TREE_INT_CST_LOW (t) = low;
1188 	  TREE_INT_CST_HIGH (t) = hi;
1189 	  TREE_TYPE (t) = type;
1190 
1191 	  TREE_VEC_ELT (TYPE_CACHED_VALUES (type), ix) = t;
1192 	}
1193     }
1194   else
1195     {
1196       /* Use the cache of larger shared ints.  */
1197       void **slot;
1198 
1199       TREE_INT_CST_LOW (int_cst_node) = low;
1200       TREE_INT_CST_HIGH (int_cst_node) = hi;
1201       TREE_TYPE (int_cst_node) = type;
1202 
1203       slot = htab_find_slot (int_cst_hash_table, int_cst_node, INSERT);
1204       t = (tree) *slot;
1205       if (!t)
1206 	{
1207 	  /* Insert this one into the hash table.  */
1208 	  t = int_cst_node;
1209 	  *slot = t;
1210 	  /* Make a new node for next time round.  */
1211 	  int_cst_node = make_node (INTEGER_CST);
1212 	}
1213     }
1214 
1215   return t;
1216 }
1217 
1218 /* Builds an integer constant in TYPE such that lowest BITS bits are ones
1219    and the rest are zeros.  */
1220 
1221 tree
1222 build_low_bits_mask (tree type, unsigned bits)
1223 {
1224   unsigned HOST_WIDE_INT low;
1225   HOST_WIDE_INT high;
1226   unsigned HOST_WIDE_INT all_ones = ~(unsigned HOST_WIDE_INT) 0;
1227 
1228   gcc_assert (bits <= TYPE_PRECISION (type));
1229 
1230   if (bits == TYPE_PRECISION (type)
1231       && !TYPE_UNSIGNED (type))
1232     {
1233       /* Sign extended all-ones mask.  */
1234       low = all_ones;
1235       high = -1;
1236     }
1237   else if (bits <= HOST_BITS_PER_WIDE_INT)
1238     {
1239       low = all_ones >> (HOST_BITS_PER_WIDE_INT - bits);
1240       high = 0;
1241     }
1242   else
1243     {
1244       bits -= HOST_BITS_PER_WIDE_INT;
1245       low = all_ones;
1246       high = all_ones >> (HOST_BITS_PER_WIDE_INT - bits);
1247     }
1248 
1249   return build_int_cst_wide (type, low, high);
1250 }
1251 
1252 /* Checks that X is integer constant that can be expressed in (unsigned)
1253    HOST_WIDE_INT without loss of precision.  */
1254 
1255 bool
1256 cst_and_fits_in_hwi (const_tree x)
1257 {
1258   if (TREE_CODE (x) != INTEGER_CST)
1259     return false;
1260 
1261   if (TYPE_PRECISION (TREE_TYPE (x)) > HOST_BITS_PER_WIDE_INT)
1262     return false;
1263 
1264   return (TREE_INT_CST_HIGH (x) == 0
1265 	  || TREE_INT_CST_HIGH (x) == -1);
1266 }
1267 
1268 /* Return a new VECTOR_CST node whose type is TYPE and whose values
1269    are in a list pointed to by VALS.  */
1270 
1271 tree
1272 build_vector (tree type, tree vals)
1273 {
1274   tree v = make_node (VECTOR_CST);
1275   int over = 0;
1276   tree link;
1277 
1278   TREE_VECTOR_CST_ELTS (v) = vals;
1279   TREE_TYPE (v) = type;
1280 
1281   /* Iterate through elements and check for overflow.  */
1282   for (link = vals; link; link = TREE_CHAIN (link))
1283     {
1284       tree value = TREE_VALUE (link);
1285 
1286       /* Don't crash if we get an address constant.  */
1287       if (!CONSTANT_CLASS_P (value))
1288 	continue;
1289 
1290       over |= TREE_OVERFLOW (value);
1291     }
1292 
1293   TREE_OVERFLOW (v) = over;
1294   return v;
1295 }
1296 
1297 /* Return a new VECTOR_CST node whose type is TYPE and whose values
1298    are extracted from V, a vector of CONSTRUCTOR_ELT.  */
1299 
1300 tree
1301 build_vector_from_ctor (tree type, VEC(constructor_elt,gc) *v)
1302 {
1303   tree list = NULL_TREE;
1304   unsigned HOST_WIDE_INT idx;
1305   tree value;
1306 
1307   FOR_EACH_CONSTRUCTOR_VALUE (v, idx, value)
1308     list = tree_cons (NULL_TREE, value, list);
1309   return build_vector (type, nreverse (list));
1310 }
1311 
1312 /* Return a new CONSTRUCTOR node whose type is TYPE and whose values
1313    are in the VEC pointed to by VALS.  */
1314 tree
1315 build_constructor (tree type, VEC(constructor_elt,gc) *vals)
1316 {
1317   tree c = make_node (CONSTRUCTOR);
1318   TREE_TYPE (c) = type;
1319   CONSTRUCTOR_ELTS (c) = vals;
1320   return c;
1321 }
1322 
1323 /* Build a CONSTRUCTOR node made of a single initializer, with the specified
1324    INDEX and VALUE.  */
1325 tree
1326 build_constructor_single (tree type, tree index, tree value)
1327 {
1328   VEC(constructor_elt,gc) *v;
1329   constructor_elt *elt;
1330   tree t;
1331 
1332   v = VEC_alloc (constructor_elt, gc, 1);
1333   elt = VEC_quick_push (constructor_elt, v, NULL);
1334   elt->index = index;
1335   elt->value = value;
1336 
1337   t = build_constructor (type, v);
1338   TREE_CONSTANT (t) = TREE_CONSTANT (value);
1339   return t;
1340 }
1341 
1342 
1343 /* Return a new CONSTRUCTOR node whose type is TYPE and whose values
1344    are in a list pointed to by VALS.  */
1345 tree
1346 build_constructor_from_list (tree type, tree vals)
1347 {
1348   tree t, val;
1349   VEC(constructor_elt,gc) *v = NULL;
1350   bool constant_p = true;
1351 
1352   if (vals)
1353     {
1354       v = VEC_alloc (constructor_elt, gc, list_length (vals));
1355       for (t = vals; t; t = TREE_CHAIN (t))
1356 	{
1357 	  constructor_elt *elt = VEC_quick_push (constructor_elt, v, NULL);
1358 	  val = TREE_VALUE (t);
1359 	  elt->index = TREE_PURPOSE (t);
1360 	  elt->value = val;
1361 	  if (!TREE_CONSTANT (val))
1362 	    constant_p = false;
1363 	}
1364     }
1365 
1366   t = build_constructor (type, v);
1367   TREE_CONSTANT (t) = constant_p;
1368   return t;
1369 }
1370 
1371 /* Return a new FIXED_CST node whose type is TYPE and value is F.  */
1372 
1373 tree
1374 build_fixed (tree type, FIXED_VALUE_TYPE f)
1375 {
1376   tree v;
1377   FIXED_VALUE_TYPE *fp;
1378 
1379   v = make_node (FIXED_CST);
1380   fp = GGC_NEW (FIXED_VALUE_TYPE);
1381   memcpy (fp, &f, sizeof (FIXED_VALUE_TYPE));
1382 
1383   TREE_TYPE (v) = type;
1384   TREE_FIXED_CST_PTR (v) = fp;
1385   return v;
1386 }
1387 
1388 /* Return a new REAL_CST node whose type is TYPE and value is D.  */
1389 
1390 tree
1391 build_real (tree type, REAL_VALUE_TYPE d)
1392 {
1393   tree v;
1394   REAL_VALUE_TYPE *dp;
1395   int overflow = 0;
1396 
1397   /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
1398      Consider doing it via real_convert now.  */
1399 
1400   v = make_node (REAL_CST);
1401   dp = GGC_NEW (REAL_VALUE_TYPE);
1402   memcpy (dp, &d, sizeof (REAL_VALUE_TYPE));
1403 
1404   TREE_TYPE (v) = type;
1405   TREE_REAL_CST_PTR (v) = dp;
1406   TREE_OVERFLOW (v) = overflow;
1407   return v;
1408 }
1409 
1410 /* Return a new REAL_CST node whose type is TYPE
1411    and whose value is the integer value of the INTEGER_CST node I.  */
1412 
1413 REAL_VALUE_TYPE
1414 real_value_from_int_cst (const_tree type, const_tree i)
1415 {
1416   REAL_VALUE_TYPE d;
1417 
1418   /* Clear all bits of the real value type so that we can later do
1419      bitwise comparisons to see if two values are the same.  */
1420   memset (&d, 0, sizeof d);
1421 
1422   real_from_integer (&d, type ? TYPE_MODE (type) : VOIDmode,
1423 		     TREE_INT_CST_LOW (i), TREE_INT_CST_HIGH (i),
1424 		     TYPE_UNSIGNED (TREE_TYPE (i)));
1425   return d;
1426 }
1427 
1428 /* Given a tree representing an integer constant I, return a tree
1429    representing the same value as a floating-point constant of type TYPE.  */
1430 
1431 tree
1432 build_real_from_int_cst (tree type, const_tree i)
1433 {
1434   tree v;
1435   int overflow = TREE_OVERFLOW (i);
1436 
1437   v = build_real (type, real_value_from_int_cst (type, i));
1438 
1439   TREE_OVERFLOW (v) |= overflow;
1440   return v;
1441 }
1442 
1443 /* Return a newly constructed STRING_CST node whose value is
1444    the LEN characters at STR.
1445    The TREE_TYPE is not initialized.  */
1446 
1447 tree
1448 build_string (int len, const char *str)
1449 {
1450   tree s;
1451   size_t length;
1452 
1453   /* Do not waste bytes provided by padding of struct tree_string.  */
1454   length = len + offsetof (struct tree_string, str) + 1;
1455 
1456 #ifdef GATHER_STATISTICS
1457   tree_node_counts[(int) c_kind]++;
1458   tree_node_sizes[(int) c_kind] += length;
1459 #endif
1460 
1461   s = ggc_alloc_tree (length);
1462 
1463   memset (s, 0, sizeof (struct tree_common));
1464   TREE_SET_CODE (s, STRING_CST);
1465   TREE_CONSTANT (s) = 1;
1466   TREE_STRING_LENGTH (s) = len;
1467   memcpy (s->string.str, str, len);
1468   s->string.str[len] = '\0';
1469 
1470   return s;
1471 }
1472 
1473 /* Return a newly constructed COMPLEX_CST node whose value is
1474    specified by the real and imaginary parts REAL and IMAG.
1475    Both REAL and IMAG should be constant nodes.  TYPE, if specified,
1476    will be the type of the COMPLEX_CST; otherwise a new type will be made.  */
1477 
1478 tree
1479 build_complex (tree type, tree real, tree imag)
1480 {
1481   tree t = make_node (COMPLEX_CST);
1482 
1483   TREE_REALPART (t) = real;
1484   TREE_IMAGPART (t) = imag;
1485   TREE_TYPE (t) = type ? type : build_complex_type (TREE_TYPE (real));
1486   TREE_OVERFLOW (t) = TREE_OVERFLOW (real) | TREE_OVERFLOW (imag);
1487   return t;
1488 }
1489 
1490 /* Return a constant of arithmetic type TYPE which is the
1491    multiplicative identity of the set TYPE.  */
1492 
1493 tree
1494 build_one_cst (tree type)
1495 {
1496   switch (TREE_CODE (type))
1497     {
1498     case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
1499     case POINTER_TYPE: case REFERENCE_TYPE:
1500     case OFFSET_TYPE:
1501       return build_int_cst (type, 1);
1502 
1503     case REAL_TYPE:
1504       return build_real (type, dconst1);
1505 
1506     case FIXED_POINT_TYPE:
1507       /* We can only generate 1 for accum types.  */
1508       gcc_assert (ALL_SCALAR_ACCUM_MODE_P (TYPE_MODE (type)));
1509       return build_fixed (type, FCONST1(TYPE_MODE (type)));
1510 
1511     case VECTOR_TYPE:
1512       {
1513 	tree scalar, cst;
1514 	int i;
1515 
1516 	scalar = build_one_cst (TREE_TYPE (type));
1517 
1518 	/* Create 'vect_cst_ = {cst,cst,...,cst}'  */
1519 	cst = NULL_TREE;
1520 	for (i = TYPE_VECTOR_SUBPARTS (type); --i >= 0; )
1521 	  cst = tree_cons (NULL_TREE, scalar, cst);
1522 
1523 	return build_vector (type, cst);
1524       }
1525 
1526     case COMPLEX_TYPE:
1527       return build_complex (type,
1528 			    build_one_cst (TREE_TYPE (type)),
1529 			    fold_convert (TREE_TYPE (type), integer_zero_node));
1530 
1531     default:
1532       gcc_unreachable ();
1533     }
1534 }
1535 
1536 /* Build a BINFO with LEN language slots.  */
1537 
1538 tree
1539 make_tree_binfo_stat (unsigned base_binfos MEM_STAT_DECL)
1540 {
1541   tree t;
1542   size_t length = (offsetof (struct tree_binfo, base_binfos)
1543 		   + VEC_embedded_size (tree, base_binfos));
1544 
1545 #ifdef GATHER_STATISTICS
1546   tree_node_counts[(int) binfo_kind]++;
1547   tree_node_sizes[(int) binfo_kind] += length;
1548 #endif
1549 
1550   t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
1551 
1552   memset (t, 0, offsetof (struct tree_binfo, base_binfos));
1553 
1554   TREE_SET_CODE (t, TREE_BINFO);
1555 
1556   VEC_embedded_init (tree, BINFO_BASE_BINFOS (t), base_binfos);
1557 
1558   return t;
1559 }
1560 
1561 
1562 /* Build a newly constructed TREE_VEC node of length LEN.  */
1563 
1564 tree
1565 make_tree_vec_stat (int len MEM_STAT_DECL)
1566 {
1567   tree t;
1568   int length = (len - 1) * sizeof (tree) + sizeof (struct tree_vec);
1569 
1570 #ifdef GATHER_STATISTICS
1571   tree_node_counts[(int) vec_kind]++;
1572   tree_node_sizes[(int) vec_kind] += length;
1573 #endif
1574 
1575   t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
1576 
1577   memset (t, 0, length);
1578 
1579   TREE_SET_CODE (t, TREE_VEC);
1580   TREE_VEC_LENGTH (t) = len;
1581 
1582   return t;
1583 }
1584 
1585 /* Return 1 if EXPR is the integer constant zero or a complex constant
1586    of zero.  */
1587 
1588 int
1589 integer_zerop (const_tree expr)
1590 {
1591   STRIP_NOPS (expr);
1592 
1593   return ((TREE_CODE (expr) == INTEGER_CST
1594 	   && TREE_INT_CST_LOW (expr) == 0
1595 	   && TREE_INT_CST_HIGH (expr) == 0)
1596 	  || (TREE_CODE (expr) == COMPLEX_CST
1597 	      && integer_zerop (TREE_REALPART (expr))
1598 	      && integer_zerop (TREE_IMAGPART (expr))));
1599 }
1600 
1601 /* Return 1 if EXPR is the integer constant one or the corresponding
1602    complex constant.  */
1603 
1604 int
1605 integer_onep (const_tree expr)
1606 {
1607   STRIP_NOPS (expr);
1608 
1609   return ((TREE_CODE (expr) == INTEGER_CST
1610 	   && TREE_INT_CST_LOW (expr) == 1
1611 	   && TREE_INT_CST_HIGH (expr) == 0)
1612 	  || (TREE_CODE (expr) == COMPLEX_CST
1613 	      && integer_onep (TREE_REALPART (expr))
1614 	      && integer_zerop (TREE_IMAGPART (expr))));
1615 }
1616 
1617 /* Return 1 if EXPR is an integer containing all 1's in as much precision as
1618    it contains.  Likewise for the corresponding complex constant.  */
1619 
1620 int
1621 integer_all_onesp (const_tree expr)
1622 {
1623   int prec;
1624   int uns;
1625 
1626   STRIP_NOPS (expr);
1627 
1628   if (TREE_CODE (expr) == COMPLEX_CST
1629       && integer_all_onesp (TREE_REALPART (expr))
1630       && integer_zerop (TREE_IMAGPART (expr)))
1631     return 1;
1632 
1633   else if (TREE_CODE (expr) != INTEGER_CST)
1634     return 0;
1635 
1636   uns = TYPE_UNSIGNED (TREE_TYPE (expr));
1637   if (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
1638       && TREE_INT_CST_HIGH (expr) == -1)
1639     return 1;
1640   if (!uns)
1641     return 0;
1642 
1643   /* Note that using TYPE_PRECISION here is wrong.  We care about the
1644      actual bits, not the (arbitrary) range of the type.  */
1645   prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)));
1646   if (prec >= HOST_BITS_PER_WIDE_INT)
1647     {
1648       HOST_WIDE_INT high_value;
1649       int shift_amount;
1650 
1651       shift_amount = prec - HOST_BITS_PER_WIDE_INT;
1652 
1653       /* Can not handle precisions greater than twice the host int size.  */
1654       gcc_assert (shift_amount <= HOST_BITS_PER_WIDE_INT);
1655       if (shift_amount == HOST_BITS_PER_WIDE_INT)
1656 	/* Shifting by the host word size is undefined according to the ANSI
1657 	   standard, so we must handle this as a special case.  */
1658 	high_value = -1;
1659       else
1660 	high_value = ((HOST_WIDE_INT) 1 << shift_amount) - 1;
1661 
1662       return (TREE_INT_CST_LOW (expr) == ~(unsigned HOST_WIDE_INT) 0
1663 	      && TREE_INT_CST_HIGH (expr) == high_value);
1664     }
1665   else
1666     return TREE_INT_CST_LOW (expr) == ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
1667 }
1668 
1669 /* Return 1 if EXPR is an integer constant that is a power of 2 (i.e., has only
1670    one bit on).  */
1671 
1672 int
1673 integer_pow2p (const_tree expr)
1674 {
1675   int prec;
1676   HOST_WIDE_INT high, low;
1677 
1678   STRIP_NOPS (expr);
1679 
1680   if (TREE_CODE (expr) == COMPLEX_CST
1681       && integer_pow2p (TREE_REALPART (expr))
1682       && integer_zerop (TREE_IMAGPART (expr)))
1683     return 1;
1684 
1685   if (TREE_CODE (expr) != INTEGER_CST)
1686     return 0;
1687 
1688   prec = TYPE_PRECISION (TREE_TYPE (expr));
1689   high = TREE_INT_CST_HIGH (expr);
1690   low = TREE_INT_CST_LOW (expr);
1691 
1692   /* First clear all bits that are beyond the type's precision in case
1693      we've been sign extended.  */
1694 
1695   if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1696     ;
1697   else if (prec > HOST_BITS_PER_WIDE_INT)
1698     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1699   else
1700     {
1701       high = 0;
1702       if (prec < HOST_BITS_PER_WIDE_INT)
1703 	low &= ~((HOST_WIDE_INT) (-1) << prec);
1704     }
1705 
1706   if (high == 0 && low == 0)
1707     return 0;
1708 
1709   return ((high == 0 && (low & (low - 1)) == 0)
1710 	  || (low == 0 && (high & (high - 1)) == 0));
1711 }
1712 
1713 /* Return 1 if EXPR is an integer constant other than zero or a
1714    complex constant other than zero.  */
1715 
1716 int
1717 integer_nonzerop (const_tree expr)
1718 {
1719   STRIP_NOPS (expr);
1720 
1721   return ((TREE_CODE (expr) == INTEGER_CST
1722 	   && (TREE_INT_CST_LOW (expr) != 0
1723 	       || TREE_INT_CST_HIGH (expr) != 0))
1724 	  || (TREE_CODE (expr) == COMPLEX_CST
1725 	      && (integer_nonzerop (TREE_REALPART (expr))
1726 		  || integer_nonzerop (TREE_IMAGPART (expr)))));
1727 }
1728 
1729 /* Return 1 if EXPR is the fixed-point constant zero.  */
1730 
1731 int
1732 fixed_zerop (const_tree expr)
1733 {
1734   return (TREE_CODE (expr) == FIXED_CST
1735 	  && double_int_zero_p (TREE_FIXED_CST (expr).data));
1736 }
1737 
1738 /* Return the power of two represented by a tree node known to be a
1739    power of two.  */
1740 
1741 int
1742 tree_log2 (const_tree expr)
1743 {
1744   int prec;
1745   HOST_WIDE_INT high, low;
1746 
1747   STRIP_NOPS (expr);
1748 
1749   if (TREE_CODE (expr) == COMPLEX_CST)
1750     return tree_log2 (TREE_REALPART (expr));
1751 
1752   prec = TYPE_PRECISION (TREE_TYPE (expr));
1753   high = TREE_INT_CST_HIGH (expr);
1754   low = TREE_INT_CST_LOW (expr);
1755 
1756   /* First clear all bits that are beyond the type's precision in case
1757      we've been sign extended.  */
1758 
1759   if (prec == 2 * HOST_BITS_PER_WIDE_INT)
1760     ;
1761   else if (prec > HOST_BITS_PER_WIDE_INT)
1762     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1763   else
1764     {
1765       high = 0;
1766       if (prec < HOST_BITS_PER_WIDE_INT)
1767 	low &= ~((HOST_WIDE_INT) (-1) << prec);
1768     }
1769 
1770   return (high != 0 ? HOST_BITS_PER_WIDE_INT + exact_log2 (high)
1771 	  : exact_log2 (low));
1772 }
1773 
1774 /* Similar, but return the largest integer Y such that 2 ** Y is less
1775    than or equal to EXPR.  */
1776 
1777 int
1778 tree_floor_log2 (const_tree expr)
1779 {
1780   int prec;
1781   HOST_WIDE_INT high, low;
1782 
1783   STRIP_NOPS (expr);
1784 
1785   if (TREE_CODE (expr) == COMPLEX_CST)
1786     return tree_log2 (TREE_REALPART (expr));
1787 
1788   prec = TYPE_PRECISION (TREE_TYPE (expr));
1789   high = TREE_INT_CST_HIGH (expr);
1790   low = TREE_INT_CST_LOW (expr);
1791 
1792   /* First clear all bits that are beyond the type's precision in case
1793      we've been sign extended.  Ignore if type's precision hasn't been set
1794      since what we are doing is setting it.  */
1795 
1796   if (prec == 2 * HOST_BITS_PER_WIDE_INT || prec == 0)
1797     ;
1798   else if (prec > HOST_BITS_PER_WIDE_INT)
1799     high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
1800   else
1801     {
1802       high = 0;
1803       if (prec < HOST_BITS_PER_WIDE_INT)
1804 	low &= ~((HOST_WIDE_INT) (-1) << prec);
1805     }
1806 
1807   return (high != 0 ? HOST_BITS_PER_WIDE_INT + floor_log2 (high)
1808 	  : floor_log2 (low));
1809 }
1810 
1811 /* Return 1 if EXPR is the real constant zero.  Trailing zeroes matter for
1812    decimal float constants, so don't return 1 for them.  */
1813 
1814 int
1815 real_zerop (const_tree expr)
1816 {
1817   STRIP_NOPS (expr);
1818 
1819   return ((TREE_CODE (expr) == REAL_CST
1820 	   && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst0)
1821 	   && !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
1822 	  || (TREE_CODE (expr) == COMPLEX_CST
1823 	      && real_zerop (TREE_REALPART (expr))
1824 	      && real_zerop (TREE_IMAGPART (expr))));
1825 }
1826 
1827 /* Return 1 if EXPR is the real constant one in real or complex form.
1828    Trailing zeroes matter for decimal float constants, so don't return
1829    1 for them.  */
1830 
1831 int
1832 real_onep (const_tree expr)
1833 {
1834   STRIP_NOPS (expr);
1835 
1836   return ((TREE_CODE (expr) == REAL_CST
1837 	   && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst1)
1838 	   && !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
1839 	  || (TREE_CODE (expr) == COMPLEX_CST
1840 	      && real_onep (TREE_REALPART (expr))
1841 	      && real_zerop (TREE_IMAGPART (expr))));
1842 }
1843 
1844 /* Return 1 if EXPR is the real constant two.  Trailing zeroes matter
1845    for decimal float constants, so don't return 1 for them.  */
1846 
1847 int
1848 real_twop (const_tree expr)
1849 {
1850   STRIP_NOPS (expr);
1851 
1852   return ((TREE_CODE (expr) == REAL_CST
1853 	   && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconst2)
1854 	   && !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
1855 	  || (TREE_CODE (expr) == COMPLEX_CST
1856 	      && real_twop (TREE_REALPART (expr))
1857 	      && real_zerop (TREE_IMAGPART (expr))));
1858 }
1859 
1860 /* Return 1 if EXPR is the real constant minus one.  Trailing zeroes
1861    matter for decimal float constants, so don't return 1 for them.  */
1862 
1863 int
1864 real_minus_onep (const_tree expr)
1865 {
1866   STRIP_NOPS (expr);
1867 
1868   return ((TREE_CODE (expr) == REAL_CST
1869 	   && REAL_VALUES_EQUAL (TREE_REAL_CST (expr), dconstm1)
1870 	   && !(DECIMAL_FLOAT_MODE_P (TYPE_MODE (TREE_TYPE (expr)))))
1871 	  || (TREE_CODE (expr) == COMPLEX_CST
1872 	      && real_minus_onep (TREE_REALPART (expr))
1873 	      && real_zerop (TREE_IMAGPART (expr))));
1874 }
1875 
1876 /* Nonzero if EXP is a constant or a cast of a constant.  */
1877 
1878 int
1879 really_constant_p (const_tree exp)
1880 {
1881   /* This is not quite the same as STRIP_NOPS.  It does more.  */
1882   while (CONVERT_EXPR_P (exp)
1883 	 || TREE_CODE (exp) == NON_LVALUE_EXPR)
1884     exp = TREE_OPERAND (exp, 0);
1885   return TREE_CONSTANT (exp);
1886 }
1887 
1888 /* Return first list element whose TREE_VALUE is ELEM.
1889    Return 0 if ELEM is not in LIST.  */
1890 
1891 tree
1892 value_member (tree elem, tree list)
1893 {
1894   while (list)
1895     {
1896       if (elem == TREE_VALUE (list))
1897 	return list;
1898       list = TREE_CHAIN (list);
1899     }
1900   return NULL_TREE;
1901 }
1902 
1903 /* Return first list element whose TREE_PURPOSE is ELEM.
1904    Return 0 if ELEM is not in LIST.  */
1905 
1906 tree
1907 purpose_member (const_tree elem, tree list)
1908 {
1909   while (list)
1910     {
1911       if (elem == TREE_PURPOSE (list))
1912 	return list;
1913       list = TREE_CHAIN (list);
1914     }
1915   return NULL_TREE;
1916 }
1917 
1918 /* Returns element number IDX (zero-origin) of chain CHAIN, or
1919    NULL_TREE.  */
1920 
1921 tree
1922 chain_index (int idx, tree chain)
1923 {
1924   for (; chain && idx > 0; --idx)
1925     chain = TREE_CHAIN (chain);
1926   return chain;
1927 }
1928 
1929 /* Return nonzero if ELEM is part of the chain CHAIN.  */
1930 
1931 int
1932 chain_member (const_tree elem, const_tree chain)
1933 {
1934   while (chain)
1935     {
1936       if (elem == chain)
1937 	return 1;
1938       chain = TREE_CHAIN (chain);
1939     }
1940 
1941   return 0;
1942 }
1943 
1944 /* Return the length of a chain of nodes chained through TREE_CHAIN.
1945    We expect a null pointer to mark the end of the chain.
1946    This is the Lisp primitive `length'.  */
1947 
1948 int
1949 list_length (const_tree t)
1950 {
1951   const_tree p = t;
1952 #ifdef ENABLE_TREE_CHECKING
1953   const_tree q = t;
1954 #endif
1955   int len = 0;
1956 
1957   while (p)
1958     {
1959       p = TREE_CHAIN (p);
1960 #ifdef ENABLE_TREE_CHECKING
1961       if (len % 2)
1962 	q = TREE_CHAIN (q);
1963       gcc_assert (p != q);
1964 #endif
1965       len++;
1966     }
1967 
1968   return len;
1969 }
1970 
1971 /* Returns the number of FIELD_DECLs in TYPE.  */
1972 
1973 int
1974 fields_length (const_tree type)
1975 {
1976   tree t = TYPE_FIELDS (type);
1977   int count = 0;
1978 
1979   for (; t; t = TREE_CHAIN (t))
1980     if (TREE_CODE (t) == FIELD_DECL)
1981       ++count;
1982 
1983   return count;
1984 }
1985 
1986 /* Returns the first FIELD_DECL in the TYPE_FIELDS of the RECORD_TYPE or
1987    UNION_TYPE TYPE, or NULL_TREE if none.  */
1988 
1989 tree
1990 first_field (const_tree type)
1991 {
1992   tree t = TYPE_FIELDS (type);
1993   while (t && TREE_CODE (t) != FIELD_DECL)
1994     t = TREE_CHAIN (t);
1995   return t;
1996 }
1997 
1998 /* Concatenate two chains of nodes (chained through TREE_CHAIN)
1999    by modifying the last node in chain 1 to point to chain 2.
2000    This is the Lisp primitive `nconc'.  */
2001 
2002 tree
2003 chainon (tree op1, tree op2)
2004 {
2005   tree t1;
2006 
2007   if (!op1)
2008     return op2;
2009   if (!op2)
2010     return op1;
2011 
2012   for (t1 = op1; TREE_CHAIN (t1); t1 = TREE_CHAIN (t1))
2013     continue;
2014   TREE_CHAIN (t1) = op2;
2015 
2016 #ifdef ENABLE_TREE_CHECKING
2017   {
2018     tree t2;
2019     for (t2 = op2; t2; t2 = TREE_CHAIN (t2))
2020       gcc_assert (t2 != t1);
2021   }
2022 #endif
2023 
2024   return op1;
2025 }
2026 
2027 /* Return the last node in a chain of nodes (chained through TREE_CHAIN).  */
2028 
2029 tree
2030 tree_last (tree chain)
2031 {
2032   tree next;
2033   if (chain)
2034     while ((next = TREE_CHAIN (chain)))
2035       chain = next;
2036   return chain;
2037 }
2038 
2039 /* Reverse the order of elements in the chain T,
2040    and return the new head of the chain (old last element).  */
2041 
2042 tree
2043 nreverse (tree t)
2044 {
2045   tree prev = 0, decl, next;
2046   for (decl = t; decl; decl = next)
2047     {
2048       next = TREE_CHAIN (decl);
2049       TREE_CHAIN (decl) = prev;
2050       prev = decl;
2051     }
2052   return prev;
2053 }
2054 
2055 /* Return a newly created TREE_LIST node whose
2056    purpose and value fields are PARM and VALUE.  */
2057 
2058 tree
2059 build_tree_list_stat (tree parm, tree value MEM_STAT_DECL)
2060 {
2061   tree t = make_node_stat (TREE_LIST PASS_MEM_STAT);
2062   TREE_PURPOSE (t) = parm;
2063   TREE_VALUE (t) = value;
2064   return t;
2065 }
2066 
2067 /* Build a chain of TREE_LIST nodes from a vector.  */
2068 
2069 tree
2070 build_tree_list_vec_stat (const VEC(tree,gc) *vec MEM_STAT_DECL)
2071 {
2072   tree ret = NULL_TREE;
2073   tree *pp = &ret;
2074   unsigned int i;
2075   tree t;
2076   for (i = 0; VEC_iterate (tree, vec, i, t); ++i)
2077     {
2078       *pp = build_tree_list_stat (NULL, t PASS_MEM_STAT);
2079       pp = &TREE_CHAIN (*pp);
2080     }
2081   return ret;
2082 }
2083 
2084 /* Return a newly created TREE_LIST node whose
2085    purpose and value fields are PURPOSE and VALUE
2086    and whose TREE_CHAIN is CHAIN.  */
2087 
2088 tree
2089 tree_cons_stat (tree purpose, tree value, tree chain MEM_STAT_DECL)
2090 {
2091   tree node;
2092 
2093   node = (tree) ggc_alloc_zone_pass_stat (sizeof (struct tree_list), &tree_zone);
2094 
2095   memset (node, 0, sizeof (struct tree_common));
2096 
2097 #ifdef GATHER_STATISTICS
2098   tree_node_counts[(int) x_kind]++;
2099   tree_node_sizes[(int) x_kind] += sizeof (struct tree_list);
2100 #endif
2101 
2102   TREE_SET_CODE (node, TREE_LIST);
2103   TREE_CHAIN (node) = chain;
2104   TREE_PURPOSE (node) = purpose;
2105   TREE_VALUE (node) = value;
2106   return node;
2107 }
2108 
2109 /* Return the elements of a CONSTRUCTOR as a TREE_LIST.  */
2110 
2111 tree
2112 ctor_to_list (tree ctor)
2113 {
2114   tree list = NULL_TREE;
2115   tree *p = &list;
2116   unsigned ix;
2117   tree purpose, val;
2118 
2119   FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), ix, purpose, val)
2120     {
2121       *p = build_tree_list (purpose, val);
2122       p = &TREE_CHAIN (*p);
2123     }
2124 
2125   return list;
2126 }
2127 
2128 /* Return the values of the elements of a CONSTRUCTOR as a vector of
2129    trees.  */
2130 
2131 VEC(tree,gc) *
2132 ctor_to_vec (tree ctor)
2133 {
2134   VEC(tree, gc) *vec = VEC_alloc (tree, gc, CONSTRUCTOR_NELTS (ctor));
2135   unsigned int ix;
2136   tree val;
2137 
2138   FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), ix, val)
2139     VEC_quick_push (tree, vec, val);
2140 
2141   return vec;
2142 }
2143 
2144 /* Return the size nominally occupied by an object of type TYPE
2145    when it resides in memory.  The value is measured in units of bytes,
2146    and its data type is that normally used for type sizes
2147    (which is the first type created by make_signed_type or
2148    make_unsigned_type).  */
2149 
2150 tree
2151 size_in_bytes (const_tree type)
2152 {
2153   tree t;
2154 
2155   if (type == error_mark_node)
2156     return integer_zero_node;
2157 
2158   type = TYPE_MAIN_VARIANT (type);
2159   t = TYPE_SIZE_UNIT (type);
2160 
2161   if (t == 0)
2162     {
2163       lang_hooks.types.incomplete_type_error (NULL_TREE, type);
2164       return size_zero_node;
2165     }
2166 
2167   return t;
2168 }
2169 
2170 /* Return the size of TYPE (in bytes) as a wide integer
2171    or return -1 if the size can vary or is larger than an integer.  */
2172 
2173 HOST_WIDE_INT
2174 int_size_in_bytes (const_tree type)
2175 {
2176   tree t;
2177 
2178   if (type == error_mark_node)
2179     return 0;
2180 
2181   type = TYPE_MAIN_VARIANT (type);
2182   t = TYPE_SIZE_UNIT (type);
2183   if (t == 0
2184       || TREE_CODE (t) != INTEGER_CST
2185       || TREE_INT_CST_HIGH (t) != 0
2186       /* If the result would appear negative, it's too big to represent.  */
2187       || (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0)
2188     return -1;
2189 
2190   return TREE_INT_CST_LOW (t);
2191 }
2192 
2193 /* Return the maximum size of TYPE (in bytes) as a wide integer
2194    or return -1 if the size can vary or is larger than an integer.  */
2195 
2196 HOST_WIDE_INT
2197 max_int_size_in_bytes (const_tree type)
2198 {
2199   HOST_WIDE_INT size = -1;
2200   tree size_tree;
2201 
2202   /* If this is an array type, check for a possible MAX_SIZE attached.  */
2203 
2204   if (TREE_CODE (type) == ARRAY_TYPE)
2205     {
2206       size_tree = TYPE_ARRAY_MAX_SIZE (type);
2207 
2208       if (size_tree && host_integerp (size_tree, 1))
2209 	size = tree_low_cst (size_tree, 1);
2210     }
2211 
2212   /* If we still haven't been able to get a size, see if the language
2213      can compute a maximum size.  */
2214 
2215   if (size == -1)
2216     {
2217       size_tree = lang_hooks.types.max_size (type);
2218 
2219       if (size_tree && host_integerp (size_tree, 1))
2220 	size = tree_low_cst (size_tree, 1);
2221     }
2222 
2223   return size;
2224 }
2225 
2226 /* Returns a tree for the size of EXP in bytes.  */
2227 
2228 tree
2229 tree_expr_size (const_tree exp)
2230 {
2231   if (DECL_P (exp)
2232       && DECL_SIZE_UNIT (exp) != 0)
2233     return DECL_SIZE_UNIT (exp);
2234   else
2235     return size_in_bytes (TREE_TYPE (exp));
2236 }
2237 
2238 /* Return the bit position of FIELD, in bits from the start of the record.
2239    This is a tree of type bitsizetype.  */
2240 
2241 tree
2242 bit_position (const_tree field)
2243 {
2244   return bit_from_pos (DECL_FIELD_OFFSET (field),
2245 		       DECL_FIELD_BIT_OFFSET (field));
2246 }
2247 
2248 /* Likewise, but return as an integer.  It must be representable in
2249    that way (since it could be a signed value, we don't have the
2250    option of returning -1 like int_size_in_byte can.  */
2251 
2252 HOST_WIDE_INT
2253 int_bit_position (const_tree field)
2254 {
2255   return tree_low_cst (bit_position (field), 0);
2256 }
2257 
2258 /* Return the byte position of FIELD, in bytes from the start of the record.
2259    This is a tree of type sizetype.  */
2260 
2261 tree
2262 byte_position (const_tree field)
2263 {
2264   return byte_from_pos (DECL_FIELD_OFFSET (field),
2265 			DECL_FIELD_BIT_OFFSET (field));
2266 }
2267 
2268 /* Likewise, but return as an integer.  It must be representable in
2269    that way (since it could be a signed value, we don't have the
2270    option of returning -1 like int_size_in_byte can.  */
2271 
2272 HOST_WIDE_INT
2273 int_byte_position (const_tree field)
2274 {
2275   return tree_low_cst (byte_position (field), 0);
2276 }
2277 
2278 /* Return the strictest alignment, in bits, that T is known to have.  */
2279 
2280 unsigned int
2281 expr_align (const_tree t)
2282 {
2283   unsigned int align0, align1;
2284 
2285   switch (TREE_CODE (t))
2286     {
2287     CASE_CONVERT:  case NON_LVALUE_EXPR:
2288       /* If we have conversions, we know that the alignment of the
2289 	 object must meet each of the alignments of the types.  */
2290       align0 = expr_align (TREE_OPERAND (t, 0));
2291       align1 = TYPE_ALIGN (TREE_TYPE (t));
2292       return MAX (align0, align1);
2293 
2294     case SAVE_EXPR:         case COMPOUND_EXPR:       case MODIFY_EXPR:
2295     case INIT_EXPR:         case TARGET_EXPR:         case WITH_CLEANUP_EXPR:
2296     case CLEANUP_POINT_EXPR:
2297       /* These don't change the alignment of an object.  */
2298       return expr_align (TREE_OPERAND (t, 0));
2299 
2300     case COND_EXPR:
2301       /* The best we can do is say that the alignment is the least aligned
2302 	 of the two arms.  */
2303       align0 = expr_align (TREE_OPERAND (t, 1));
2304       align1 = expr_align (TREE_OPERAND (t, 2));
2305       return MIN (align0, align1);
2306 
2307       /* FIXME: LABEL_DECL and CONST_DECL never have DECL_ALIGN set
2308 	 meaningfully, it's always 1.  */
2309     case LABEL_DECL:     case CONST_DECL:
2310     case VAR_DECL:       case PARM_DECL:   case RESULT_DECL:
2311     case FUNCTION_DECL:
2312       gcc_assert (DECL_ALIGN (t) != 0);
2313       return DECL_ALIGN (t);
2314 
2315     default:
2316       break;
2317     }
2318 
2319   /* Otherwise take the alignment from that of the type.  */
2320   return TYPE_ALIGN (TREE_TYPE (t));
2321 }
2322 
2323 /* Return, as a tree node, the number of elements for TYPE (which is an
2324    ARRAY_TYPE) minus one. This counts only elements of the top array.  */
2325 
2326 tree
2327 array_type_nelts (const_tree type)
2328 {
2329   tree index_type, min, max;
2330 
2331   /* If they did it with unspecified bounds, then we should have already
2332      given an error about it before we got here.  */
2333   if (! TYPE_DOMAIN (type))
2334     return error_mark_node;
2335 
2336   index_type = TYPE_DOMAIN (type);
2337   min = TYPE_MIN_VALUE (index_type);
2338   max = TYPE_MAX_VALUE (index_type);
2339 
2340   /* TYPE_MAX_VALUE may not be set if the array has unknown length.  */
2341   if (!max)
2342     return error_mark_node;
2343 
2344   return (integer_zerop (min)
2345 	  ? max
2346 	  : fold_build2 (MINUS_EXPR, TREE_TYPE (max), max, min));
2347 }
2348 
2349 /* If arg is static -- a reference to an object in static storage -- then
2350    return the object.  This is not the same as the C meaning of `static'.
2351    If arg isn't static, return NULL.  */
2352 
2353 tree
2354 staticp (tree arg)
2355 {
2356   switch (TREE_CODE (arg))
2357     {
2358     case FUNCTION_DECL:
2359       /* Nested functions are static, even though taking their address will
2360 	 involve a trampoline as we unnest the nested function and create
2361 	 the trampoline on the tree level.  */
2362       return arg;
2363 
2364     case VAR_DECL:
2365       return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2366 	      && ! DECL_THREAD_LOCAL_P (arg)
2367 	      && ! DECL_DLLIMPORT_P (arg)
2368 	      ? arg : NULL);
2369 
2370     case CONST_DECL:
2371       return ((TREE_STATIC (arg) || DECL_EXTERNAL (arg))
2372 	      ? arg : NULL);
2373 
2374     case CONSTRUCTOR:
2375       return TREE_STATIC (arg) ? arg : NULL;
2376 
2377     case LABEL_DECL:
2378     case STRING_CST:
2379       return arg;
2380 
2381     case COMPONENT_REF:
2382       /* If the thing being referenced is not a field, then it is
2383 	 something language specific.  */
2384       gcc_assert (TREE_CODE (TREE_OPERAND (arg, 1)) == FIELD_DECL);
2385 
2386       /* If we are referencing a bitfield, we can't evaluate an
2387 	 ADDR_EXPR at compile time and so it isn't a constant.  */
2388       if (DECL_BIT_FIELD (TREE_OPERAND (arg, 1)))
2389 	return NULL;
2390 
2391       return staticp (TREE_OPERAND (arg, 0));
2392 
2393     case BIT_FIELD_REF:
2394       return NULL;
2395 
2396     case MISALIGNED_INDIRECT_REF:
2397     case ALIGN_INDIRECT_REF:
2398     case INDIRECT_REF:
2399       return TREE_CONSTANT (TREE_OPERAND (arg, 0)) ? arg : NULL;
2400 
2401     case ARRAY_REF:
2402     case ARRAY_RANGE_REF:
2403       if (TREE_CODE (TYPE_SIZE (TREE_TYPE (arg))) == INTEGER_CST
2404 	  && TREE_CODE (TREE_OPERAND (arg, 1)) == INTEGER_CST)
2405 	return staticp (TREE_OPERAND (arg, 0));
2406       else
2407 	return NULL;
2408 
2409     case COMPOUND_LITERAL_EXPR:
2410       return TREE_STATIC (COMPOUND_LITERAL_EXPR_DECL (arg)) ? arg : NULL;
2411 
2412     default:
2413       return NULL;
2414     }
2415 }
2416 
2417 
2418 
2419 
2420 /* Return whether OP is a DECL whose address is function-invariant.  */
2421 
2422 bool
2423 decl_address_invariant_p (const_tree op)
2424 {
2425   /* The conditions below are slightly less strict than the one in
2426      staticp.  */
2427 
2428   switch (TREE_CODE (op))
2429     {
2430     case PARM_DECL:
2431     case RESULT_DECL:
2432     case LABEL_DECL:
2433     case FUNCTION_DECL:
2434       return true;
2435 
2436     case VAR_DECL:
2437       if (((TREE_STATIC (op) || DECL_EXTERNAL (op))
2438            && !DECL_DLLIMPORT_P (op))
2439           || DECL_THREAD_LOCAL_P (op)
2440           || DECL_CONTEXT (op) == current_function_decl
2441           || decl_function_context (op) == current_function_decl)
2442         return true;
2443       break;
2444 
2445     case CONST_DECL:
2446       if ((TREE_STATIC (op) || DECL_EXTERNAL (op))
2447           || decl_function_context (op) == current_function_decl)
2448         return true;
2449       break;
2450 
2451     default:
2452       break;
2453     }
2454 
2455   return false;
2456 }
2457 
2458 /* Return whether OP is a DECL whose address is interprocedural-invariant.  */
2459 
2460 bool
2461 decl_address_ip_invariant_p (const_tree op)
2462 {
2463   /* The conditions below are slightly less strict than the one in
2464      staticp.  */
2465 
2466   switch (TREE_CODE (op))
2467     {
2468     case LABEL_DECL:
2469     case FUNCTION_DECL:
2470     case STRING_CST:
2471       return true;
2472 
2473     case VAR_DECL:
2474       if (((TREE_STATIC (op) || DECL_EXTERNAL (op))
2475            && !DECL_DLLIMPORT_P (op))
2476           || DECL_THREAD_LOCAL_P (op))
2477         return true;
2478       break;
2479 
2480     case CONST_DECL:
2481       if ((TREE_STATIC (op) || DECL_EXTERNAL (op)))
2482         return true;
2483       break;
2484 
2485     default:
2486       break;
2487     }
2488 
2489   return false;
2490 }
2491 
2492 
2493 /* Return true if T is function-invariant (internal function, does
2494    not handle arithmetic; that's handled in skip_simple_arithmetic and
2495    tree_invariant_p).  */
2496 
2497 static bool tree_invariant_p (tree t);
2498 
2499 static bool
2500 tree_invariant_p_1 (tree t)
2501 {
2502   tree op;
2503 
2504   if (TREE_CONSTANT (t)
2505       || (TREE_READONLY (t) && !TREE_SIDE_EFFECTS (t)))
2506     return true;
2507 
2508   switch (TREE_CODE (t))
2509     {
2510     case SAVE_EXPR:
2511       return true;
2512 
2513     case ADDR_EXPR:
2514       op = TREE_OPERAND (t, 0);
2515       while (handled_component_p (op))
2516 	{
2517 	  switch (TREE_CODE (op))
2518 	    {
2519 	    case ARRAY_REF:
2520 	    case ARRAY_RANGE_REF:
2521 	      if (!tree_invariant_p (TREE_OPERAND (op, 1))
2522 		  || TREE_OPERAND (op, 2) != NULL_TREE
2523 		  || TREE_OPERAND (op, 3) != NULL_TREE)
2524 		return false;
2525 	      break;
2526 
2527 	    case COMPONENT_REF:
2528 	      if (TREE_OPERAND (op, 2) != NULL_TREE)
2529 		return false;
2530 	      break;
2531 
2532 	    default:;
2533 	    }
2534 	  op = TREE_OPERAND (op, 0);
2535 	}
2536 
2537       return CONSTANT_CLASS_P (op) || decl_address_invariant_p (op);
2538 
2539     default:
2540       break;
2541     }
2542 
2543   return false;
2544 }
2545 
2546 /* Return true if T is function-invariant.  */
2547 
2548 static bool
2549 tree_invariant_p (tree t)
2550 {
2551   tree inner = skip_simple_arithmetic (t);
2552   return tree_invariant_p_1 (inner);
2553 }
2554 
2555 /* Wrap a SAVE_EXPR around EXPR, if appropriate.
2556    Do this to any expression which may be used in more than one place,
2557    but must be evaluated only once.
2558 
2559    Normally, expand_expr would reevaluate the expression each time.
2560    Calling save_expr produces something that is evaluated and recorded
2561    the first time expand_expr is called on it.  Subsequent calls to
2562    expand_expr just reuse the recorded value.
2563 
2564    The call to expand_expr that generates code that actually computes
2565    the value is the first call *at compile time*.  Subsequent calls
2566    *at compile time* generate code to use the saved value.
2567    This produces correct result provided that *at run time* control
2568    always flows through the insns made by the first expand_expr
2569    before reaching the other places where the save_expr was evaluated.
2570    You, the caller of save_expr, must make sure this is so.
2571 
2572    Constants, and certain read-only nodes, are returned with no
2573    SAVE_EXPR because that is safe.  Expressions containing placeholders
2574    are not touched; see tree.def for an explanation of what these
2575    are used for.  */
2576 
2577 tree
2578 save_expr (tree expr)
2579 {
2580   tree t = fold (expr);
2581   tree inner;
2582 
2583   /* If the tree evaluates to a constant, then we don't want to hide that
2584      fact (i.e. this allows further folding, and direct checks for constants).
2585      However, a read-only object that has side effects cannot be bypassed.
2586      Since it is no problem to reevaluate literals, we just return the
2587      literal node.  */
2588   inner = skip_simple_arithmetic (t);
2589   if (TREE_CODE (inner) == ERROR_MARK)
2590     return inner;
2591 
2592   if (tree_invariant_p_1 (inner))
2593     return t;
2594 
2595   /* If INNER contains a PLACEHOLDER_EXPR, we must evaluate it each time, since
2596      it means that the size or offset of some field of an object depends on
2597      the value within another field.
2598 
2599      Note that it must not be the case that T contains both a PLACEHOLDER_EXPR
2600      and some variable since it would then need to be both evaluated once and
2601      evaluated more than once.  Front-ends must assure this case cannot
2602      happen by surrounding any such subexpressions in their own SAVE_EXPR
2603      and forcing evaluation at the proper time.  */
2604   if (contains_placeholder_p (inner))
2605     return t;
2606 
2607   t = build1 (SAVE_EXPR, TREE_TYPE (expr), t);
2608   SET_EXPR_LOCATION (t, EXPR_LOCATION (expr));
2609 
2610   /* This expression might be placed ahead of a jump to ensure that the
2611      value was computed on both sides of the jump.  So make sure it isn't
2612      eliminated as dead.  */
2613   TREE_SIDE_EFFECTS (t) = 1;
2614   return t;
2615 }
2616 
2617 /* Look inside EXPR and into any simple arithmetic operations.  Return
2618    the innermost non-arithmetic node.  */
2619 
2620 tree
2621 skip_simple_arithmetic (tree expr)
2622 {
2623   tree inner;
2624 
2625   /* We don't care about whether this can be used as an lvalue in this
2626      context.  */
2627   while (TREE_CODE (expr) == NON_LVALUE_EXPR)
2628     expr = TREE_OPERAND (expr, 0);
2629 
2630   /* If we have simple operations applied to a SAVE_EXPR or to a SAVE_EXPR and
2631      a constant, it will be more efficient to not make another SAVE_EXPR since
2632      it will allow better simplification and GCSE will be able to merge the
2633      computations if they actually occur.  */
2634   inner = expr;
2635   while (1)
2636     {
2637       if (UNARY_CLASS_P (inner))
2638 	inner = TREE_OPERAND (inner, 0);
2639       else if (BINARY_CLASS_P (inner))
2640 	{
2641 	  if (tree_invariant_p (TREE_OPERAND (inner, 1)))
2642 	    inner = TREE_OPERAND (inner, 0);
2643 	  else if (tree_invariant_p (TREE_OPERAND (inner, 0)))
2644 	    inner = TREE_OPERAND (inner, 1);
2645 	  else
2646 	    break;
2647 	}
2648       else
2649 	break;
2650     }
2651 
2652   return inner;
2653 }
2654 
2655 
2656 /* Return which tree structure is used by T.  */
2657 
2658 enum tree_node_structure_enum
2659 tree_node_structure (const_tree t)
2660 {
2661   const enum tree_code code = TREE_CODE (t);
2662   return tree_node_structure_for_code (code);
2663 }
2664 
2665 /* Set various status flags when building a CALL_EXPR object T.  */
2666 
2667 static void
2668 process_call_operands (tree t)
2669 {
2670   bool side_effects = TREE_SIDE_EFFECTS (t);
2671   bool read_only = false;
2672   int i = call_expr_flags (t);
2673 
2674   /* Calls have side-effects, except those to const or pure functions.  */
2675   if ((i & ECF_LOOPING_CONST_OR_PURE) || !(i & (ECF_CONST | ECF_PURE)))
2676     side_effects = true;
2677   /* Propagate TREE_READONLY of arguments for const functions.  */
2678   if (i & ECF_CONST)
2679     read_only = true;
2680 
2681   if (!side_effects || read_only)
2682     for (i = 1; i < TREE_OPERAND_LENGTH (t); i++)
2683       {
2684 	tree op = TREE_OPERAND (t, i);
2685 	if (op && TREE_SIDE_EFFECTS (op))
2686 	  side_effects = true;
2687 	if (op && !TREE_READONLY (op) && !CONSTANT_CLASS_P (op))
2688 	  read_only = false;
2689       }
2690 
2691   TREE_SIDE_EFFECTS (t) = side_effects;
2692   TREE_READONLY (t) = read_only;
2693 }
2694 
2695 /* Return 1 if EXP contains a PLACEHOLDER_EXPR; i.e., if it represents a size
2696    or offset that depends on a field within a record.  */
2697 
2698 bool
2699 contains_placeholder_p (const_tree exp)
2700 {
2701   enum tree_code code;
2702 
2703   if (!exp)
2704     return 0;
2705 
2706   code = TREE_CODE (exp);
2707   if (code == PLACEHOLDER_EXPR)
2708     return 1;
2709 
2710   switch (TREE_CODE_CLASS (code))
2711     {
2712     case tcc_reference:
2713       /* Don't look at any PLACEHOLDER_EXPRs that might be in index or bit
2714 	 position computations since they will be converted into a
2715 	 WITH_RECORD_EXPR involving the reference, which will assume
2716 	 here will be valid.  */
2717       return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
2718 
2719     case tcc_exceptional:
2720       if (code == TREE_LIST)
2721 	return (CONTAINS_PLACEHOLDER_P (TREE_VALUE (exp))
2722 		|| CONTAINS_PLACEHOLDER_P (TREE_CHAIN (exp)));
2723       break;
2724 
2725     case tcc_unary:
2726     case tcc_binary:
2727     case tcc_comparison:
2728     case tcc_expression:
2729       switch (code)
2730 	{
2731 	case COMPOUND_EXPR:
2732 	  /* Ignoring the first operand isn't quite right, but works best.  */
2733 	  return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1));
2734 
2735 	case COND_EXPR:
2736 	  return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
2737 		  || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1))
2738 		  || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 2)));
2739 
2740 	case SAVE_EXPR:
2741 	  /* The save_expr function never wraps anything containing
2742 	     a PLACEHOLDER_EXPR. */
2743 	  return 0;
2744 
2745 	default:
2746 	  break;
2747 	}
2748 
2749       switch (TREE_CODE_LENGTH (code))
2750 	{
2751 	case 1:
2752 	  return CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0));
2753 	case 2:
2754 	  return (CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 0))
2755 		  || CONTAINS_PLACEHOLDER_P (TREE_OPERAND (exp, 1)));
2756 	default:
2757 	  return 0;
2758 	}
2759 
2760     case tcc_vl_exp:
2761       switch (code)
2762 	{
2763 	case CALL_EXPR:
2764 	  {
2765 	    const_tree arg;
2766 	    const_call_expr_arg_iterator iter;
2767 	    FOR_EACH_CONST_CALL_EXPR_ARG (arg, iter, exp)
2768 	      if (CONTAINS_PLACEHOLDER_P (arg))
2769 		return 1;
2770 	    return 0;
2771 	  }
2772 	default:
2773 	  return 0;
2774 	}
2775 
2776     default:
2777       return 0;
2778     }
2779   return 0;
2780 }
2781 
2782 /* Return true if any part of the computation of TYPE involves a
2783    PLACEHOLDER_EXPR.  This includes size, bounds, qualifiers
2784    (for QUAL_UNION_TYPE) and field positions.  */
2785 
2786 static bool
2787 type_contains_placeholder_1 (const_tree type)
2788 {
2789   /* If the size contains a placeholder or the parent type (component type in
2790      the case of arrays) type involves a placeholder, this type does.  */
2791   if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
2792       || CONTAINS_PLACEHOLDER_P (TYPE_SIZE_UNIT (type))
2793       || (TREE_TYPE (type) != 0
2794 	  && type_contains_placeholder_p (TREE_TYPE (type))))
2795     return true;
2796 
2797   /* Now do type-specific checks.  Note that the last part of the check above
2798      greatly limits what we have to do below.  */
2799   switch (TREE_CODE (type))
2800     {
2801     case VOID_TYPE:
2802     case COMPLEX_TYPE:
2803     case ENUMERAL_TYPE:
2804     case BOOLEAN_TYPE:
2805     case POINTER_TYPE:
2806     case OFFSET_TYPE:
2807     case REFERENCE_TYPE:
2808     case METHOD_TYPE:
2809     case FUNCTION_TYPE:
2810     case VECTOR_TYPE:
2811       return false;
2812 
2813     case INTEGER_TYPE:
2814     case REAL_TYPE:
2815     case FIXED_POINT_TYPE:
2816       /* Here we just check the bounds.  */
2817       return (CONTAINS_PLACEHOLDER_P (TYPE_MIN_VALUE (type))
2818 	      || CONTAINS_PLACEHOLDER_P (TYPE_MAX_VALUE (type)));
2819 
2820     case ARRAY_TYPE:
2821       /* We're already checked the component type (TREE_TYPE), so just check
2822 	 the index type.  */
2823       return type_contains_placeholder_p (TYPE_DOMAIN (type));
2824 
2825     case RECORD_TYPE:
2826     case UNION_TYPE:
2827     case QUAL_UNION_TYPE:
2828       {
2829 	tree field;
2830 
2831 	for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
2832 	  if (TREE_CODE (field) == FIELD_DECL
2833 	      && (CONTAINS_PLACEHOLDER_P (DECL_FIELD_OFFSET (field))
2834 		  || (TREE_CODE (type) == QUAL_UNION_TYPE
2835 		      && CONTAINS_PLACEHOLDER_P (DECL_QUALIFIER (field)))
2836 		  || type_contains_placeholder_p (TREE_TYPE (field))))
2837 	    return true;
2838 
2839 	return false;
2840       }
2841 
2842     default:
2843       gcc_unreachable ();
2844     }
2845 }
2846 
2847 bool
2848 type_contains_placeholder_p (tree type)
2849 {
2850   bool result;
2851 
2852   /* If the contains_placeholder_bits field has been initialized,
2853      then we know the answer.  */
2854   if (TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) > 0)
2855     return TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) - 1;
2856 
2857   /* Indicate that we've seen this type node, and the answer is false.
2858      This is what we want to return if we run into recursion via fields.  */
2859   TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = 1;
2860 
2861   /* Compute the real value.  */
2862   result = type_contains_placeholder_1 (type);
2863 
2864   /* Store the real value.  */
2865   TYPE_CONTAINS_PLACEHOLDER_INTERNAL (type) = result + 1;
2866 
2867   return result;
2868 }
2869 
2870 /* Push tree EXP onto vector QUEUE if it is not already present.  */
2871 
2872 static void
2873 push_without_duplicates (tree exp, VEC (tree, heap) **queue)
2874 {
2875   unsigned int i;
2876   tree iter;
2877 
2878   for (i = 0; VEC_iterate (tree, *queue, i, iter); i++)
2879     if (simple_cst_equal (iter, exp) == 1)
2880       break;
2881 
2882   if (!iter)
2883     VEC_safe_push (tree, heap, *queue, exp);
2884 }
2885 
2886 /* Given a tree EXP, find all occurences of references to fields
2887    in a PLACEHOLDER_EXPR and place them in vector REFS without
2888    duplicates.  Also record VAR_DECLs and CONST_DECLs.  Note that
2889    we assume here that EXP contains only arithmetic expressions
2890    or CALL_EXPRs with PLACEHOLDER_EXPRs occurring only in their
2891    argument list.  */
2892 
2893 void
2894 find_placeholder_in_expr (tree exp, VEC (tree, heap) **refs)
2895 {
2896   enum tree_code code = TREE_CODE (exp);
2897   tree inner;
2898   int i;
2899 
2900   /* We handle TREE_LIST and COMPONENT_REF separately.  */
2901   if (code == TREE_LIST)
2902     {
2903       FIND_PLACEHOLDER_IN_EXPR (TREE_CHAIN (exp), refs);
2904       FIND_PLACEHOLDER_IN_EXPR (TREE_VALUE (exp), refs);
2905     }
2906   else if (code == COMPONENT_REF)
2907     {
2908       for (inner = TREE_OPERAND (exp, 0);
2909 	   REFERENCE_CLASS_P (inner);
2910 	   inner = TREE_OPERAND (inner, 0))
2911 	;
2912 
2913       if (TREE_CODE (inner) == PLACEHOLDER_EXPR)
2914 	push_without_duplicates (exp, refs);
2915       else
2916 	FIND_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), refs);
2917    }
2918   else
2919     switch (TREE_CODE_CLASS (code))
2920       {
2921       case tcc_constant:
2922 	break;
2923 
2924       case tcc_declaration:
2925 	/* Variables allocated to static storage can stay.  */
2926         if (!TREE_STATIC (exp))
2927 	  push_without_duplicates (exp, refs);
2928 	break;
2929 
2930       case tcc_expression:
2931 	/* This is the pattern built in ada/make_aligning_type.  */
2932 	if (code == ADDR_EXPR
2933 	    && TREE_CODE (TREE_OPERAND (exp, 0)) == PLACEHOLDER_EXPR)
2934 	  {
2935 	    push_without_duplicates (exp, refs);
2936 	    break;
2937 	  }
2938 
2939         /* Fall through...  */
2940 
2941       case tcc_exceptional:
2942       case tcc_unary:
2943       case tcc_binary:
2944       case tcc_comparison:
2945       case tcc_reference:
2946 	for (i = 0; i < TREE_CODE_LENGTH (code); i++)
2947 	  FIND_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, i), refs);
2948 	break;
2949 
2950       case tcc_vl_exp:
2951 	for (i = 1; i < TREE_OPERAND_LENGTH (exp); i++)
2952 	  FIND_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, i), refs);
2953 	break;
2954 
2955       default:
2956 	gcc_unreachable ();
2957       }
2958 }
2959 
2960 /* Given a tree EXP, a FIELD_DECL F, and a replacement value R,
2961    return a tree with all occurrences of references to F in a
2962    PLACEHOLDER_EXPR replaced by R.  Also handle VAR_DECLs and
2963    CONST_DECLs.  Note that we assume here that EXP contains only
2964    arithmetic expressions or CALL_EXPRs with PLACEHOLDER_EXPRs
2965    occurring only in their argument list.  */
2966 
2967 tree
2968 substitute_in_expr (tree exp, tree f, tree r)
2969 {
2970   enum tree_code code = TREE_CODE (exp);
2971   tree op0, op1, op2, op3;
2972   tree new_tree;
2973 
2974   /* We handle TREE_LIST and COMPONENT_REF separately.  */
2975   if (code == TREE_LIST)
2976     {
2977       op0 = SUBSTITUTE_IN_EXPR (TREE_CHAIN (exp), f, r);
2978       op1 = SUBSTITUTE_IN_EXPR (TREE_VALUE (exp), f, r);
2979       if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
2980 	return exp;
2981 
2982       return tree_cons (TREE_PURPOSE (exp), op1, op0);
2983     }
2984   else if (code == COMPONENT_REF)
2985     {
2986       tree inner;
2987 
2988       /* If this expression is getting a value from a PLACEHOLDER_EXPR
2989 	 and it is the right field, replace it with R.  */
2990       for (inner = TREE_OPERAND (exp, 0);
2991 	   REFERENCE_CLASS_P (inner);
2992 	   inner = TREE_OPERAND (inner, 0))
2993 	;
2994 
2995       /* The field.  */
2996       op1 = TREE_OPERAND (exp, 1);
2997 
2998       if (TREE_CODE (inner) == PLACEHOLDER_EXPR && op1 == f)
2999 	return r;
3000 
3001       /* If this expression hasn't been completed let, leave it alone.  */
3002       if (TREE_CODE (inner) == PLACEHOLDER_EXPR && !TREE_TYPE (inner))
3003 	return exp;
3004 
3005       op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3006       if (op0 == TREE_OPERAND (exp, 0))
3007 	return exp;
3008 
3009       new_tree
3010 	= fold_build3 (COMPONENT_REF, TREE_TYPE (exp), op0, op1, NULL_TREE);
3011    }
3012   else
3013     switch (TREE_CODE_CLASS (code))
3014       {
3015       case tcc_constant:
3016 	return exp;
3017 
3018       case tcc_declaration:
3019 	if (exp == f)
3020 	  return r;
3021 	else
3022 	  return exp;
3023 
3024       case tcc_expression:
3025 	if (exp == f)
3026 	  return r;
3027 
3028         /* Fall through...  */
3029 
3030       case tcc_exceptional:
3031       case tcc_unary:
3032       case tcc_binary:
3033       case tcc_comparison:
3034       case tcc_reference:
3035 	switch (TREE_CODE_LENGTH (code))
3036 	  {
3037 	  case 0:
3038 	    return exp;
3039 
3040 	  case 1:
3041 	    op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3042 	    if (op0 == TREE_OPERAND (exp, 0))
3043 	      return exp;
3044 
3045 	    new_tree = fold_build1 (code, TREE_TYPE (exp), op0);
3046 	    break;
3047 
3048 	  case 2:
3049 	    op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3050 	    op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
3051 
3052 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
3053 	      return exp;
3054 
3055 	    new_tree = fold_build2 (code, TREE_TYPE (exp), op0, op1);
3056 	    break;
3057 
3058 	  case 3:
3059 	    op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3060 	    op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
3061 	    op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
3062 
3063 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3064 		&& op2 == TREE_OPERAND (exp, 2))
3065 	      return exp;
3066 
3067 	    new_tree = fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
3068 	    break;
3069 
3070 	  case 4:
3071 	    op0 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 0), f, r);
3072 	    op1 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 1), f, r);
3073 	    op2 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 2), f, r);
3074 	    op3 = SUBSTITUTE_IN_EXPR (TREE_OPERAND (exp, 3), f, r);
3075 
3076 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3077 		&& op2 == TREE_OPERAND (exp, 2)
3078 		&& op3 == TREE_OPERAND (exp, 3))
3079 	      return exp;
3080 
3081 	    new_tree
3082 	      = fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
3083 	    break;
3084 
3085 	  default:
3086 	    gcc_unreachable ();
3087 	  }
3088 	break;
3089 
3090       case tcc_vl_exp:
3091 	{
3092 	  int i;
3093 
3094 	  new_tree = NULL_TREE;
3095 
3096 	  /* If we are trying to replace F with a constant, inline back
3097 	     functions which do nothing else than computing a value from
3098 	     the arguments they are passed.  This makes it possible to
3099 	     fold partially or entirely the replacement expression.  */
3100 	  if (CONSTANT_CLASS_P (r) && code == CALL_EXPR)
3101 	    {
3102 	      tree t = maybe_inline_call_in_expr (exp);
3103 	      if (t)
3104 		return SUBSTITUTE_IN_EXPR (t, f, r);
3105 	    }
3106 
3107 	  for (i = 1; i < TREE_OPERAND_LENGTH (exp); i++)
3108 	    {
3109 	      tree op = TREE_OPERAND (exp, i);
3110 	      tree new_op = SUBSTITUTE_IN_EXPR (op, f, r);
3111 	      if (new_op != op)
3112 		{
3113 		  if (!new_tree)
3114 		    new_tree = copy_node (exp);
3115 		  TREE_OPERAND (new_tree, i) = new_op;
3116 		}
3117 	    }
3118 
3119 	  if (new_tree)
3120 	    {
3121 	      new_tree = fold (new_tree);
3122 	      if (TREE_CODE (new_tree) == CALL_EXPR)
3123 		process_call_operands (new_tree);
3124 	    }
3125 	  else
3126 	    return exp;
3127 	}
3128 	break;
3129 
3130       default:
3131 	gcc_unreachable ();
3132       }
3133 
3134   TREE_READONLY (new_tree) |= TREE_READONLY (exp);
3135   return new_tree;
3136 }
3137 
3138 /* Similar, but look for a PLACEHOLDER_EXPR in EXP and find a replacement
3139    for it within OBJ, a tree that is an object or a chain of references.  */
3140 
3141 tree
3142 substitute_placeholder_in_expr (tree exp, tree obj)
3143 {
3144   enum tree_code code = TREE_CODE (exp);
3145   tree op0, op1, op2, op3;
3146   tree new_tree;
3147 
3148   /* If this is a PLACEHOLDER_EXPR, see if we find a corresponding type
3149      in the chain of OBJ.  */
3150   if (code == PLACEHOLDER_EXPR)
3151     {
3152       tree need_type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
3153       tree elt;
3154 
3155       for (elt = obj; elt != 0;
3156 	   elt = ((TREE_CODE (elt) == COMPOUND_EXPR
3157 		   || TREE_CODE (elt) == COND_EXPR)
3158 		  ? TREE_OPERAND (elt, 1)
3159 		  : (REFERENCE_CLASS_P (elt)
3160 		     || UNARY_CLASS_P (elt)
3161 		     || BINARY_CLASS_P (elt)
3162 		     || VL_EXP_CLASS_P (elt)
3163 		     || EXPRESSION_CLASS_P (elt))
3164 		  ? TREE_OPERAND (elt, 0) : 0))
3165 	if (TYPE_MAIN_VARIANT (TREE_TYPE (elt)) == need_type)
3166 	  return elt;
3167 
3168       for (elt = obj; elt != 0;
3169 	   elt = ((TREE_CODE (elt) == COMPOUND_EXPR
3170 		   || TREE_CODE (elt) == COND_EXPR)
3171 		  ? TREE_OPERAND (elt, 1)
3172 		  : (REFERENCE_CLASS_P (elt)
3173 		     || UNARY_CLASS_P (elt)
3174 		     || BINARY_CLASS_P (elt)
3175 		     || VL_EXP_CLASS_P (elt)
3176 		     || EXPRESSION_CLASS_P (elt))
3177 		  ? TREE_OPERAND (elt, 0) : 0))
3178 	if (POINTER_TYPE_P (TREE_TYPE (elt))
3179 	    && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (elt)))
3180 		== need_type))
3181 	  return fold_build1 (INDIRECT_REF, need_type, elt);
3182 
3183       /* If we didn't find it, return the original PLACEHOLDER_EXPR.  If it
3184 	 survives until RTL generation, there will be an error.  */
3185       return exp;
3186     }
3187 
3188   /* TREE_LIST is special because we need to look at TREE_VALUE
3189      and TREE_CHAIN, not TREE_OPERANDS.  */
3190   else if (code == TREE_LIST)
3191     {
3192       op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_CHAIN (exp), obj);
3193       op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_VALUE (exp), obj);
3194       if (op0 == TREE_CHAIN (exp) && op1 == TREE_VALUE (exp))
3195 	return exp;
3196 
3197       return tree_cons (TREE_PURPOSE (exp), op1, op0);
3198     }
3199   else
3200     switch (TREE_CODE_CLASS (code))
3201       {
3202       case tcc_constant:
3203       case tcc_declaration:
3204 	return exp;
3205 
3206       case tcc_exceptional:
3207       case tcc_unary:
3208       case tcc_binary:
3209       case tcc_comparison:
3210       case tcc_expression:
3211       case tcc_reference:
3212       case tcc_statement:
3213 	switch (TREE_CODE_LENGTH (code))
3214 	  {
3215 	  case 0:
3216 	    return exp;
3217 
3218 	  case 1:
3219 	    op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
3220 	    if (op0 == TREE_OPERAND (exp, 0))
3221 	      return exp;
3222 
3223 	    new_tree = fold_build1 (code, TREE_TYPE (exp), op0);
3224 	    break;
3225 
3226 	  case 2:
3227 	    op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
3228 	    op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
3229 
3230 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1))
3231 	      return exp;
3232 
3233 	    new_tree = fold_build2 (code, TREE_TYPE (exp), op0, op1);
3234 	    break;
3235 
3236 	  case 3:
3237 	    op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
3238 	    op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
3239 	    op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
3240 
3241 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3242 		&& op2 == TREE_OPERAND (exp, 2))
3243 	      return exp;
3244 
3245 	    new_tree = fold_build3 (code, TREE_TYPE (exp), op0, op1, op2);
3246 	    break;
3247 
3248 	  case 4:
3249 	    op0 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 0), obj);
3250 	    op1 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 1), obj);
3251 	    op2 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 2), obj);
3252 	    op3 = SUBSTITUTE_PLACEHOLDER_IN_EXPR (TREE_OPERAND (exp, 3), obj);
3253 
3254 	    if (op0 == TREE_OPERAND (exp, 0) && op1 == TREE_OPERAND (exp, 1)
3255 		&& op2 == TREE_OPERAND (exp, 2)
3256 		&& op3 == TREE_OPERAND (exp, 3))
3257 	      return exp;
3258 
3259 	    new_tree
3260 	      = fold (build4 (code, TREE_TYPE (exp), op0, op1, op2, op3));
3261 	    break;
3262 
3263 	  default:
3264 	    gcc_unreachable ();
3265 	  }
3266 	break;
3267 
3268       case tcc_vl_exp:
3269 	{
3270 	  int i;
3271 
3272 	  new_tree = NULL_TREE;
3273 
3274 	  for (i = 1; i < TREE_OPERAND_LENGTH (exp); i++)
3275 	    {
3276 	      tree op = TREE_OPERAND (exp, i);
3277 	      tree new_op = SUBSTITUTE_PLACEHOLDER_IN_EXPR (op, obj);
3278 	      if (new_op != op)
3279 		{
3280 		  if (!new_tree)
3281 		    new_tree = copy_node (exp);
3282 		  TREE_OPERAND (new_tree, i) = new_op;
3283 		}
3284 	    }
3285 
3286 	  if (new_tree)
3287 	    {
3288 	      new_tree = fold (new_tree);
3289 	      if (TREE_CODE (new_tree) == CALL_EXPR)
3290 		process_call_operands (new_tree);
3291 	    }
3292 	  else
3293 	    return exp;
3294 	}
3295 	break;
3296 
3297       default:
3298 	gcc_unreachable ();
3299       }
3300 
3301   TREE_READONLY (new_tree) |= TREE_READONLY (exp);
3302   return new_tree;
3303 }
3304 
3305 /* Stabilize a reference so that we can use it any number of times
3306    without causing its operands to be evaluated more than once.
3307    Returns the stabilized reference.  This works by means of save_expr,
3308    so see the caveats in the comments about save_expr.
3309 
3310    Also allows conversion expressions whose operands are references.
3311    Any other kind of expression is returned unchanged.  */
3312 
3313 tree
3314 stabilize_reference (tree ref)
3315 {
3316   tree result;
3317   enum tree_code code = TREE_CODE (ref);
3318 
3319   switch (code)
3320     {
3321     case VAR_DECL:
3322     case PARM_DECL:
3323     case RESULT_DECL:
3324       /* No action is needed in this case.  */
3325       return ref;
3326 
3327     CASE_CONVERT:
3328     case FLOAT_EXPR:
3329     case FIX_TRUNC_EXPR:
3330       result = build_nt (code, stabilize_reference (TREE_OPERAND (ref, 0)));
3331       break;
3332 
3333     case INDIRECT_REF:
3334       result = build_nt (INDIRECT_REF,
3335 			 stabilize_reference_1 (TREE_OPERAND (ref, 0)));
3336       break;
3337 
3338     case COMPONENT_REF:
3339       result = build_nt (COMPONENT_REF,
3340 			 stabilize_reference (TREE_OPERAND (ref, 0)),
3341 			 TREE_OPERAND (ref, 1), NULL_TREE);
3342       break;
3343 
3344     case BIT_FIELD_REF:
3345       result = build_nt (BIT_FIELD_REF,
3346 			 stabilize_reference (TREE_OPERAND (ref, 0)),
3347 			 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
3348 			 stabilize_reference_1 (TREE_OPERAND (ref, 2)));
3349       break;
3350 
3351     case ARRAY_REF:
3352       result = build_nt (ARRAY_REF,
3353 			 stabilize_reference (TREE_OPERAND (ref, 0)),
3354 			 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
3355 			 TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
3356       break;
3357 
3358     case ARRAY_RANGE_REF:
3359       result = build_nt (ARRAY_RANGE_REF,
3360 			 stabilize_reference (TREE_OPERAND (ref, 0)),
3361 			 stabilize_reference_1 (TREE_OPERAND (ref, 1)),
3362 			 TREE_OPERAND (ref, 2), TREE_OPERAND (ref, 3));
3363       break;
3364 
3365     case COMPOUND_EXPR:
3366       /* We cannot wrap the first expression in a SAVE_EXPR, as then
3367 	 it wouldn't be ignored.  This matters when dealing with
3368 	 volatiles.  */
3369       return stabilize_reference_1 (ref);
3370 
3371       /* If arg isn't a kind of lvalue we recognize, make no change.
3372 	 Caller should recognize the error for an invalid lvalue.  */
3373     default:
3374       return ref;
3375 
3376     case ERROR_MARK:
3377       return error_mark_node;
3378     }
3379 
3380   TREE_TYPE (result) = TREE_TYPE (ref);
3381   TREE_READONLY (result) = TREE_READONLY (ref);
3382   TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (ref);
3383   TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (ref);
3384 
3385   return result;
3386 }
3387 
3388 /* Subroutine of stabilize_reference; this is called for subtrees of
3389    references.  Any expression with side-effects must be put in a SAVE_EXPR
3390    to ensure that it is only evaluated once.
3391 
3392    We don't put SAVE_EXPR nodes around everything, because assigning very
3393    simple expressions to temporaries causes us to miss good opportunities
3394    for optimizations.  Among other things, the opportunity to fold in the
3395    addition of a constant into an addressing mode often gets lost, e.g.
3396    "y[i+1] += x;".  In general, we take the approach that we should not make
3397    an assignment unless we are forced into it - i.e., that any non-side effect
3398    operator should be allowed, and that cse should take care of coalescing
3399    multiple utterances of the same expression should that prove fruitful.  */
3400 
3401 tree
3402 stabilize_reference_1 (tree e)
3403 {
3404   tree result;
3405   enum tree_code code = TREE_CODE (e);
3406 
3407   /* We cannot ignore const expressions because it might be a reference
3408      to a const array but whose index contains side-effects.  But we can
3409      ignore things that are actual constant or that already have been
3410      handled by this function.  */
3411 
3412   if (tree_invariant_p (e))
3413     return e;
3414 
3415   switch (TREE_CODE_CLASS (code))
3416     {
3417     case tcc_exceptional:
3418     case tcc_type:
3419     case tcc_declaration:
3420     case tcc_comparison:
3421     case tcc_statement:
3422     case tcc_expression:
3423     case tcc_reference:
3424     case tcc_vl_exp:
3425       /* If the expression has side-effects, then encase it in a SAVE_EXPR
3426 	 so that it will only be evaluated once.  */
3427       /* The reference (r) and comparison (<) classes could be handled as
3428 	 below, but it is generally faster to only evaluate them once.  */
3429       if (TREE_SIDE_EFFECTS (e))
3430 	return save_expr (e);
3431       return e;
3432 
3433     case tcc_constant:
3434       /* Constants need no processing.  In fact, we should never reach
3435 	 here.  */
3436       return e;
3437 
3438     case tcc_binary:
3439       /* Division is slow and tends to be compiled with jumps,
3440 	 especially the division by powers of 2 that is often
3441 	 found inside of an array reference.  So do it just once.  */
3442       if (code == TRUNC_DIV_EXPR || code == TRUNC_MOD_EXPR
3443 	  || code == FLOOR_DIV_EXPR || code == FLOOR_MOD_EXPR
3444 	  || code == CEIL_DIV_EXPR || code == CEIL_MOD_EXPR
3445 	  || code == ROUND_DIV_EXPR || code == ROUND_MOD_EXPR)
3446 	return save_expr (e);
3447       /* Recursively stabilize each operand.  */
3448       result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)),
3449 			 stabilize_reference_1 (TREE_OPERAND (e, 1)));
3450       break;
3451 
3452     case tcc_unary:
3453       /* Recursively stabilize each operand.  */
3454       result = build_nt (code, stabilize_reference_1 (TREE_OPERAND (e, 0)));
3455       break;
3456 
3457     default:
3458       gcc_unreachable ();
3459     }
3460 
3461   TREE_TYPE (result) = TREE_TYPE (e);
3462   TREE_READONLY (result) = TREE_READONLY (e);
3463   TREE_SIDE_EFFECTS (result) = TREE_SIDE_EFFECTS (e);
3464   TREE_THIS_VOLATILE (result) = TREE_THIS_VOLATILE (e);
3465 
3466   return result;
3467 }
3468 
3469 /* Low-level constructors for expressions.  */
3470 
3471 /* A helper function for build1 and constant folders.  Set TREE_CONSTANT,
3472    and TREE_SIDE_EFFECTS for an ADDR_EXPR.  */
3473 
3474 void
3475 recompute_tree_invariant_for_addr_expr (tree t)
3476 {
3477   tree node;
3478   bool tc = true, se = false;
3479 
3480   /* We started out assuming this address is both invariant and constant, but
3481      does not have side effects.  Now go down any handled components and see if
3482      any of them involve offsets that are either non-constant or non-invariant.
3483      Also check for side-effects.
3484 
3485      ??? Note that this code makes no attempt to deal with the case where
3486      taking the address of something causes a copy due to misalignment.  */
3487 
3488 #define UPDATE_FLAGS(NODE)  \
3489 do { tree _node = (NODE); \
3490      if (_node && !TREE_CONSTANT (_node)) tc = false; \
3491      if (_node && TREE_SIDE_EFFECTS (_node)) se = true; } while (0)
3492 
3493   for (node = TREE_OPERAND (t, 0); handled_component_p (node);
3494        node = TREE_OPERAND (node, 0))
3495     {
3496       /* If the first operand doesn't have an ARRAY_TYPE, this is a bogus
3497 	 array reference (probably made temporarily by the G++ front end),
3498 	 so ignore all the operands.  */
3499       if ((TREE_CODE (node) == ARRAY_REF
3500 	   || TREE_CODE (node) == ARRAY_RANGE_REF)
3501 	  && TREE_CODE (TREE_TYPE (TREE_OPERAND (node, 0))) == ARRAY_TYPE)
3502 	{
3503 	  UPDATE_FLAGS (TREE_OPERAND (node, 1));
3504 	  if (TREE_OPERAND (node, 2))
3505 	    UPDATE_FLAGS (TREE_OPERAND (node, 2));
3506 	  if (TREE_OPERAND (node, 3))
3507 	    UPDATE_FLAGS (TREE_OPERAND (node, 3));
3508 	}
3509       /* Likewise, just because this is a COMPONENT_REF doesn't mean we have a
3510 	 FIELD_DECL, apparently.  The G++ front end can put something else
3511 	 there, at least temporarily.  */
3512       else if (TREE_CODE (node) == COMPONENT_REF
3513 	       && TREE_CODE (TREE_OPERAND (node, 1)) == FIELD_DECL)
3514 	{
3515 	  if (TREE_OPERAND (node, 2))
3516 	    UPDATE_FLAGS (TREE_OPERAND (node, 2));
3517 	}
3518       else if (TREE_CODE (node) == BIT_FIELD_REF)
3519 	UPDATE_FLAGS (TREE_OPERAND (node, 2));
3520     }
3521 
3522   node = lang_hooks.expr_to_decl (node, &tc, &se);
3523 
3524   /* Now see what's inside.  If it's an INDIRECT_REF, copy our properties from
3525      the address, since &(*a)->b is a form of addition.  If it's a constant, the
3526      address is constant too.  If it's a decl, its address is constant if the
3527      decl is static.  Everything else is not constant and, furthermore,
3528      taking the address of a volatile variable is not volatile.  */
3529   if (TREE_CODE (node) == INDIRECT_REF)
3530     UPDATE_FLAGS (TREE_OPERAND (node, 0));
3531   else if (CONSTANT_CLASS_P (node))
3532     ;
3533   else if (DECL_P (node))
3534     tc &= (staticp (node) != NULL_TREE);
3535   else
3536     {
3537       tc = false;
3538       se |= TREE_SIDE_EFFECTS (node);
3539     }
3540 
3541 
3542   TREE_CONSTANT (t) = tc;
3543   TREE_SIDE_EFFECTS (t) = se;
3544 #undef UPDATE_FLAGS
3545 }
3546 
3547 /* Build an expression of code CODE, data type TYPE, and operands as
3548    specified.  Expressions and reference nodes can be created this way.
3549    Constants, decls, types and misc nodes cannot be.
3550 
3551    We define 5 non-variadic functions, from 0 to 4 arguments.  This is
3552    enough for all extant tree codes.  */
3553 
3554 tree
3555 build0_stat (enum tree_code code, tree tt MEM_STAT_DECL)
3556 {
3557   tree t;
3558 
3559   gcc_assert (TREE_CODE_LENGTH (code) == 0);
3560 
3561   t = make_node_stat (code PASS_MEM_STAT);
3562   TREE_TYPE (t) = tt;
3563 
3564   return t;
3565 }
3566 
3567 tree
3568 build1_stat (enum tree_code code, tree type, tree node MEM_STAT_DECL)
3569 {
3570   int length = sizeof (struct tree_exp);
3571 #ifdef GATHER_STATISTICS
3572   tree_node_kind kind;
3573 #endif
3574   tree t;
3575 
3576 #ifdef GATHER_STATISTICS
3577   switch (TREE_CODE_CLASS (code))
3578     {
3579     case tcc_statement:  /* an expression with side effects */
3580       kind = s_kind;
3581       break;
3582     case tcc_reference:  /* a reference */
3583       kind = r_kind;
3584       break;
3585     default:
3586       kind = e_kind;
3587       break;
3588     }
3589 
3590   tree_node_counts[(int) kind]++;
3591   tree_node_sizes[(int) kind] += length;
3592 #endif
3593 
3594   gcc_assert (TREE_CODE_LENGTH (code) == 1);
3595 
3596   t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
3597 
3598   memset (t, 0, sizeof (struct tree_common));
3599 
3600   TREE_SET_CODE (t, code);
3601 
3602   TREE_TYPE (t) = type;
3603   SET_EXPR_LOCATION (t, UNKNOWN_LOCATION);
3604   TREE_OPERAND (t, 0) = node;
3605   TREE_BLOCK (t) = NULL_TREE;
3606   if (node && !TYPE_P (node))
3607     {
3608       TREE_SIDE_EFFECTS (t) = TREE_SIDE_EFFECTS (node);
3609       TREE_READONLY (t) = TREE_READONLY (node);
3610     }
3611 
3612   if (TREE_CODE_CLASS (code) == tcc_statement)
3613     TREE_SIDE_EFFECTS (t) = 1;
3614   else switch (code)
3615     {
3616     case VA_ARG_EXPR:
3617       /* All of these have side-effects, no matter what their
3618 	 operands are.  */
3619       TREE_SIDE_EFFECTS (t) = 1;
3620       TREE_READONLY (t) = 0;
3621       break;
3622 
3623     case MISALIGNED_INDIRECT_REF:
3624     case ALIGN_INDIRECT_REF:
3625     case INDIRECT_REF:
3626       /* Whether a dereference is readonly has nothing to do with whether
3627 	 its operand is readonly.  */
3628       TREE_READONLY (t) = 0;
3629       break;
3630 
3631     case ADDR_EXPR:
3632       if (node)
3633 	recompute_tree_invariant_for_addr_expr (t);
3634       break;
3635 
3636     default:
3637       if ((TREE_CODE_CLASS (code) == tcc_unary || code == VIEW_CONVERT_EXPR)
3638 	  && node && !TYPE_P (node)
3639 	  && TREE_CONSTANT (node))
3640 	TREE_CONSTANT (t) = 1;
3641       if (TREE_CODE_CLASS (code) == tcc_reference
3642 	  && node && TREE_THIS_VOLATILE (node))
3643 	TREE_THIS_VOLATILE (t) = 1;
3644       break;
3645     }
3646 
3647   return t;
3648 }
3649 
3650 #define PROCESS_ARG(N)				\
3651   do {						\
3652     TREE_OPERAND (t, N) = arg##N;		\
3653     if (arg##N &&!TYPE_P (arg##N))		\
3654       {						\
3655         if (TREE_SIDE_EFFECTS (arg##N))		\
3656 	  side_effects = 1;			\
3657         if (!TREE_READONLY (arg##N)		\
3658 	    && !CONSTANT_CLASS_P (arg##N))	\
3659 	  read_only = 0;			\
3660         if (!TREE_CONSTANT (arg##N))		\
3661 	  constant = 0;				\
3662       }						\
3663   } while (0)
3664 
3665 tree
3666 build2_stat (enum tree_code code, tree tt, tree arg0, tree arg1 MEM_STAT_DECL)
3667 {
3668   bool constant, read_only, side_effects;
3669   tree t;
3670 
3671   gcc_assert (TREE_CODE_LENGTH (code) == 2);
3672 
3673   if ((code == MINUS_EXPR || code == PLUS_EXPR || code == MULT_EXPR)
3674       && arg0 && arg1 && tt && POINTER_TYPE_P (tt)
3675       /* When sizetype precision doesn't match that of pointers
3676          we need to be able to build explicit extensions or truncations
3677 	 of the offset argument.  */
3678       && TYPE_PRECISION (sizetype) == TYPE_PRECISION (tt))
3679     gcc_assert (TREE_CODE (arg0) == INTEGER_CST
3680 		&& TREE_CODE (arg1) == INTEGER_CST);
3681 
3682   if (code == POINTER_PLUS_EXPR && arg0 && arg1 && tt)
3683     gcc_assert (POINTER_TYPE_P (tt) && POINTER_TYPE_P (TREE_TYPE (arg0))
3684 		&& INTEGRAL_TYPE_P (TREE_TYPE (arg1))
3685 		&& useless_type_conversion_p (sizetype, TREE_TYPE (arg1)));
3686 
3687   t = make_node_stat (code PASS_MEM_STAT);
3688   TREE_TYPE (t) = tt;
3689 
3690   /* Below, we automatically set TREE_SIDE_EFFECTS and TREE_READONLY for the
3691      result based on those same flags for the arguments.  But if the
3692      arguments aren't really even `tree' expressions, we shouldn't be trying
3693      to do this.  */
3694 
3695   /* Expressions without side effects may be constant if their
3696      arguments are as well.  */
3697   constant = (TREE_CODE_CLASS (code) == tcc_comparison
3698 	      || TREE_CODE_CLASS (code) == tcc_binary);
3699   read_only = 1;
3700   side_effects = TREE_SIDE_EFFECTS (t);
3701 
3702   PROCESS_ARG(0);
3703   PROCESS_ARG(1);
3704 
3705   TREE_READONLY (t) = read_only;
3706   TREE_CONSTANT (t) = constant;
3707   TREE_SIDE_EFFECTS (t) = side_effects;
3708   TREE_THIS_VOLATILE (t)
3709     = (TREE_CODE_CLASS (code) == tcc_reference
3710        && arg0 && TREE_THIS_VOLATILE (arg0));
3711 
3712   return t;
3713 }
3714 
3715 
3716 tree
3717 build3_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3718 	     tree arg2 MEM_STAT_DECL)
3719 {
3720   bool constant, read_only, side_effects;
3721   tree t;
3722 
3723   gcc_assert (TREE_CODE_LENGTH (code) == 3);
3724   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
3725 
3726   t = make_node_stat (code PASS_MEM_STAT);
3727   TREE_TYPE (t) = tt;
3728 
3729   read_only = 1;
3730 
3731   /* As a special exception, if COND_EXPR has NULL branches, we
3732      assume that it is a gimple statement and always consider
3733      it to have side effects.  */
3734   if (code == COND_EXPR
3735       && tt == void_type_node
3736       && arg1 == NULL_TREE
3737       && arg2 == NULL_TREE)
3738     side_effects = true;
3739   else
3740     side_effects = TREE_SIDE_EFFECTS (t);
3741 
3742   PROCESS_ARG(0);
3743   PROCESS_ARG(1);
3744   PROCESS_ARG(2);
3745 
3746   if (code == COND_EXPR)
3747     TREE_READONLY (t) = read_only;
3748 
3749   TREE_SIDE_EFFECTS (t) = side_effects;
3750   TREE_THIS_VOLATILE (t)
3751     = (TREE_CODE_CLASS (code) == tcc_reference
3752        && arg0 && TREE_THIS_VOLATILE (arg0));
3753 
3754   return t;
3755 }
3756 
3757 tree
3758 build4_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3759 	     tree arg2, tree arg3 MEM_STAT_DECL)
3760 {
3761   bool constant, read_only, side_effects;
3762   tree t;
3763 
3764   gcc_assert (TREE_CODE_LENGTH (code) == 4);
3765 
3766   t = make_node_stat (code PASS_MEM_STAT);
3767   TREE_TYPE (t) = tt;
3768 
3769   side_effects = TREE_SIDE_EFFECTS (t);
3770 
3771   PROCESS_ARG(0);
3772   PROCESS_ARG(1);
3773   PROCESS_ARG(2);
3774   PROCESS_ARG(3);
3775 
3776   TREE_SIDE_EFFECTS (t) = side_effects;
3777   TREE_THIS_VOLATILE (t)
3778     = (TREE_CODE_CLASS (code) == tcc_reference
3779        && arg0 && TREE_THIS_VOLATILE (arg0));
3780 
3781   return t;
3782 }
3783 
3784 tree
3785 build5_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3786 	     tree arg2, tree arg3, tree arg4 MEM_STAT_DECL)
3787 {
3788   bool constant, read_only, side_effects;
3789   tree t;
3790 
3791   gcc_assert (TREE_CODE_LENGTH (code) == 5);
3792 
3793   t = make_node_stat (code PASS_MEM_STAT);
3794   TREE_TYPE (t) = tt;
3795 
3796   side_effects = TREE_SIDE_EFFECTS (t);
3797 
3798   PROCESS_ARG(0);
3799   PROCESS_ARG(1);
3800   PROCESS_ARG(2);
3801   PROCESS_ARG(3);
3802   PROCESS_ARG(4);
3803 
3804   TREE_SIDE_EFFECTS (t) = side_effects;
3805   TREE_THIS_VOLATILE (t)
3806     = (TREE_CODE_CLASS (code) == tcc_reference
3807        && arg0 && TREE_THIS_VOLATILE (arg0));
3808 
3809   return t;
3810 }
3811 
3812 tree
3813 build6_stat (enum tree_code code, tree tt, tree arg0, tree arg1,
3814 	     tree arg2, tree arg3, tree arg4, tree arg5 MEM_STAT_DECL)
3815 {
3816   bool constant, read_only, side_effects;
3817   tree t;
3818 
3819   gcc_assert (code == TARGET_MEM_REF);
3820 
3821   t = make_node_stat (code PASS_MEM_STAT);
3822   TREE_TYPE (t) = tt;
3823 
3824   side_effects = TREE_SIDE_EFFECTS (t);
3825 
3826   PROCESS_ARG(0);
3827   PROCESS_ARG(1);
3828   PROCESS_ARG(2);
3829   PROCESS_ARG(3);
3830   PROCESS_ARG(4);
3831   if (code == TARGET_MEM_REF)
3832     side_effects = 0;
3833   PROCESS_ARG(5);
3834 
3835   TREE_SIDE_EFFECTS (t) = side_effects;
3836   TREE_THIS_VOLATILE (t)
3837     = (code == TARGET_MEM_REF
3838        && arg5 && TREE_THIS_VOLATILE (arg5));
3839 
3840   return t;
3841 }
3842 
3843 /* Similar except don't specify the TREE_TYPE
3844    and leave the TREE_SIDE_EFFECTS as 0.
3845    It is permissible for arguments to be null,
3846    or even garbage if their values do not matter.  */
3847 
3848 tree
3849 build_nt (enum tree_code code, ...)
3850 {
3851   tree t;
3852   int length;
3853   int i;
3854   va_list p;
3855 
3856   gcc_assert (TREE_CODE_CLASS (code) != tcc_vl_exp);
3857 
3858   va_start (p, code);
3859 
3860   t = make_node (code);
3861   length = TREE_CODE_LENGTH (code);
3862 
3863   for (i = 0; i < length; i++)
3864     TREE_OPERAND (t, i) = va_arg (p, tree);
3865 
3866   va_end (p);
3867   return t;
3868 }
3869 
3870 /* Similar to build_nt, but for creating a CALL_EXPR object with
3871    ARGLIST passed as a list.  */
3872 
3873 tree
3874 build_nt_call_list (tree fn, tree arglist)
3875 {
3876   tree t;
3877   int i;
3878 
3879   t = build_vl_exp (CALL_EXPR, list_length (arglist) + 3);
3880   CALL_EXPR_FN (t) = fn;
3881   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
3882   for (i = 0; arglist; arglist = TREE_CHAIN (arglist), i++)
3883     CALL_EXPR_ARG (t, i) = TREE_VALUE (arglist);
3884   return t;
3885 }
3886 
3887 /* Similar to build_nt, but for creating a CALL_EXPR object with a
3888    tree VEC.  */
3889 
3890 tree
3891 build_nt_call_vec (tree fn, VEC(tree,gc) *args)
3892 {
3893   tree ret, t;
3894   unsigned int ix;
3895 
3896   ret = build_vl_exp (CALL_EXPR, VEC_length (tree, args) + 3);
3897   CALL_EXPR_FN (ret) = fn;
3898   CALL_EXPR_STATIC_CHAIN (ret) = NULL_TREE;
3899   for (ix = 0; VEC_iterate (tree, args, ix, t); ++ix)
3900     CALL_EXPR_ARG (ret, ix) = t;
3901   return ret;
3902 }
3903 
3904 /* Create a DECL_... node of code CODE, name NAME and data type TYPE.
3905    We do NOT enter this node in any sort of symbol table.
3906 
3907    LOC is the location of the decl.
3908 
3909    layout_decl is used to set up the decl's storage layout.
3910    Other slots are initialized to 0 or null pointers.  */
3911 
3912 tree
3913 build_decl_stat (location_t loc, enum tree_code code, tree name,
3914     		 tree type MEM_STAT_DECL)
3915 {
3916   tree t;
3917 
3918   t = make_node_stat (code PASS_MEM_STAT);
3919   DECL_SOURCE_LOCATION (t) = loc;
3920 
3921 /*  if (type == error_mark_node)
3922     type = integer_type_node; */
3923 /* That is not done, deliberately, so that having error_mark_node
3924    as the type can suppress useless errors in the use of this variable.  */
3925 
3926   DECL_NAME (t) = name;
3927   TREE_TYPE (t) = type;
3928 
3929   if (code == VAR_DECL || code == PARM_DECL || code == RESULT_DECL)
3930     layout_decl (t, 0);
3931 
3932   return t;
3933 }
3934 
3935 /* Builds and returns function declaration with NAME and TYPE.  */
3936 
3937 tree
3938 build_fn_decl (const char *name, tree type)
3939 {
3940   tree id = get_identifier (name);
3941   tree decl = build_decl (input_location, FUNCTION_DECL, id, type);
3942 
3943   DECL_EXTERNAL (decl) = 1;
3944   TREE_PUBLIC (decl) = 1;
3945   DECL_ARTIFICIAL (decl) = 1;
3946   TREE_NOTHROW (decl) = 1;
3947 
3948   return decl;
3949 }
3950 
3951 
3952 /* BLOCK nodes are used to represent the structure of binding contours
3953    and declarations, once those contours have been exited and their contents
3954    compiled.  This information is used for outputting debugging info.  */
3955 
3956 tree
3957 build_block (tree vars, tree subblocks, tree supercontext, tree chain)
3958 {
3959   tree block = make_node (BLOCK);
3960 
3961   BLOCK_VARS (block) = vars;
3962   BLOCK_SUBBLOCKS (block) = subblocks;
3963   BLOCK_SUPERCONTEXT (block) = supercontext;
3964   BLOCK_CHAIN (block) = chain;
3965   return block;
3966 }
3967 
3968 expanded_location
3969 expand_location (source_location loc)
3970 {
3971   expanded_location xloc;
3972   if (loc <= BUILTINS_LOCATION)
3973     {
3974       xloc.file = loc == UNKNOWN_LOCATION ? NULL : _("<built-in>");
3975       xloc.line = 0;
3976       xloc.column = 0;
3977       xloc.sysp = 0;
3978     }
3979   else
3980     {
3981       const struct line_map *map = linemap_lookup (line_table, loc);
3982       xloc.file = map->to_file;
3983       xloc.line = SOURCE_LINE (map, loc);
3984       xloc.column = SOURCE_COLUMN (map, loc);
3985       xloc.sysp = map->sysp != 0;
3986     };
3987   return xloc;
3988 }
3989 
3990 
3991 /* Like SET_EXPR_LOCATION, but make sure the tree can have a location.
3992 
3993    LOC is the location to use in tree T.  */
3994 
3995 void
3996 protected_set_expr_location (tree t, location_t loc)
3997 {
3998   if (t && CAN_HAVE_LOCATION_P (t))
3999     SET_EXPR_LOCATION (t, loc);
4000 }
4001 
4002 /* Return a declaration like DDECL except that its DECL_ATTRIBUTES
4003    is ATTRIBUTE.  */
4004 
4005 tree
4006 build_decl_attribute_variant (tree ddecl, tree attribute)
4007 {
4008   DECL_ATTRIBUTES (ddecl) = attribute;
4009   return ddecl;
4010 }
4011 
4012 /* Borrowed from hashtab.c iterative_hash implementation.  */
4013 #define mix(a,b,c) \
4014 { \
4015   a -= b; a -= c; a ^= (c>>13); \
4016   b -= c; b -= a; b ^= (a<< 8); \
4017   c -= a; c -= b; c ^= ((b&0xffffffff)>>13); \
4018   a -= b; a -= c; a ^= ((c&0xffffffff)>>12); \
4019   b -= c; b -= a; b = (b ^ (a<<16)) & 0xffffffff; \
4020   c -= a; c -= b; c = (c ^ (b>> 5)) & 0xffffffff; \
4021   a -= b; a -= c; a = (a ^ (c>> 3)) & 0xffffffff; \
4022   b -= c; b -= a; b = (b ^ (a<<10)) & 0xffffffff; \
4023   c -= a; c -= b; c = (c ^ (b>>15)) & 0xffffffff; \
4024 }
4025 
4026 
4027 /* Produce good hash value combining VAL and VAL2.  */
4028 hashval_t
4029 iterative_hash_hashval_t (hashval_t val, hashval_t val2)
4030 {
4031   /* the golden ratio; an arbitrary value.  */
4032   hashval_t a = 0x9e3779b9;
4033 
4034   mix (a, val, val2);
4035   return val2;
4036 }
4037 
4038 /* Produce good hash value combining VAL and VAL2.  */
4039 hashval_t
4040 iterative_hash_host_wide_int (HOST_WIDE_INT val, hashval_t val2)
4041 {
4042   if (sizeof (HOST_WIDE_INT) == sizeof (hashval_t))
4043     return iterative_hash_hashval_t (val, val2);
4044   else
4045     {
4046       hashval_t a = (hashval_t) val;
4047       /* Avoid warnings about shifting of more than the width of the type on
4048          hosts that won't execute this path.  */
4049       int zero = 0;
4050       hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 8 + zero));
4051       mix (a, b, val2);
4052       if (sizeof (HOST_WIDE_INT) > 2 * sizeof (hashval_t))
4053 	{
4054 	  hashval_t a = (hashval_t) (val >> (sizeof (hashval_t) * 16 + zero));
4055 	  hashval_t b = (hashval_t) (val >> (sizeof (hashval_t) * 24 + zero));
4056 	  mix (a, b, val2);
4057 	}
4058       return val2;
4059     }
4060 }
4061 
4062 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
4063    is ATTRIBUTE and its qualifiers are QUALS.
4064 
4065    Record such modified types already made so we don't make duplicates.  */
4066 
4067 tree
4068 build_type_attribute_qual_variant (tree ttype, tree attribute, int quals)
4069 {
4070   if (! attribute_list_equal (TYPE_ATTRIBUTES (ttype), attribute))
4071     {
4072       hashval_t hashcode = 0;
4073       tree ntype;
4074       enum tree_code code = TREE_CODE (ttype);
4075 
4076       /* Building a distinct copy of a tagged type is inappropriate; it
4077 	 causes breakage in code that expects there to be a one-to-one
4078 	 relationship between a struct and its fields.
4079 	 build_duplicate_type is another solution (as used in
4080 	 handle_transparent_union_attribute), but that doesn't play well
4081 	 with the stronger C++ type identity model.  */
4082       if (TREE_CODE (ttype) == RECORD_TYPE
4083 	  || TREE_CODE (ttype) == UNION_TYPE
4084 	  || TREE_CODE (ttype) == QUAL_UNION_TYPE
4085 	  || TREE_CODE (ttype) == ENUMERAL_TYPE)
4086 	{
4087 	  warning (OPT_Wattributes,
4088 		   "ignoring attributes applied to %qT after definition",
4089 		   TYPE_MAIN_VARIANT (ttype));
4090 	  return build_qualified_type (ttype, quals);
4091 	}
4092 
4093       ttype = build_qualified_type (ttype, TYPE_UNQUALIFIED);
4094       ntype = build_distinct_type_copy (ttype);
4095 
4096       TYPE_ATTRIBUTES (ntype) = attribute;
4097 
4098       hashcode = iterative_hash_object (code, hashcode);
4099       if (TREE_TYPE (ntype))
4100 	hashcode = iterative_hash_object (TYPE_HASH (TREE_TYPE (ntype)),
4101 					  hashcode);
4102       hashcode = attribute_hash_list (attribute, hashcode);
4103 
4104       switch (TREE_CODE (ntype))
4105 	{
4106 	case FUNCTION_TYPE:
4107 	  hashcode = type_hash_list (TYPE_ARG_TYPES (ntype), hashcode);
4108 	  break;
4109 	case ARRAY_TYPE:
4110 	  if (TYPE_DOMAIN (ntype))
4111 	    hashcode = iterative_hash_object (TYPE_HASH (TYPE_DOMAIN (ntype)),
4112 					      hashcode);
4113 	  break;
4114 	case INTEGER_TYPE:
4115 	  hashcode = iterative_hash_object
4116 	    (TREE_INT_CST_LOW (TYPE_MAX_VALUE (ntype)), hashcode);
4117 	  hashcode = iterative_hash_object
4118 	    (TREE_INT_CST_HIGH (TYPE_MAX_VALUE (ntype)), hashcode);
4119 	  break;
4120 	case REAL_TYPE:
4121 	case FIXED_POINT_TYPE:
4122 	  {
4123 	    unsigned int precision = TYPE_PRECISION (ntype);
4124 	    hashcode = iterative_hash_object (precision, hashcode);
4125 	  }
4126 	  break;
4127 	default:
4128 	  break;
4129 	}
4130 
4131       ntype = type_hash_canon (hashcode, ntype);
4132 
4133       /* If the target-dependent attributes make NTYPE different from
4134 	 its canonical type, we will need to use structural equality
4135 	 checks for this type. */
4136       if (TYPE_STRUCTURAL_EQUALITY_P (ttype)
4137           || !targetm.comp_type_attributes (ntype, ttype))
4138 	SET_TYPE_STRUCTURAL_EQUALITY (ntype);
4139       else if (TYPE_CANONICAL (ntype) == ntype)
4140 	TYPE_CANONICAL (ntype) = TYPE_CANONICAL (ttype);
4141 
4142       ttype = build_qualified_type (ntype, quals);
4143     }
4144   else if (TYPE_QUALS (ttype) != quals)
4145     ttype = build_qualified_type (ttype, quals);
4146 
4147   return ttype;
4148 }
4149 
4150 
4151 /* Return a type like TTYPE except that its TYPE_ATTRIBUTE
4152    is ATTRIBUTE.
4153 
4154    Record such modified types already made so we don't make duplicates.  */
4155 
4156 tree
4157 build_type_attribute_variant (tree ttype, tree attribute)
4158 {
4159   return build_type_attribute_qual_variant (ttype, attribute,
4160 					    TYPE_QUALS (ttype));
4161 }
4162 
4163 
4164 /* Reset all the fields in a binfo node BINFO.  We only keep
4165    BINFO_VIRTUALS, which is used by gimple_fold_obj_type_ref.  */
4166 
4167 static void
4168 free_lang_data_in_binfo (tree binfo)
4169 {
4170   unsigned i;
4171   tree t;
4172 
4173   gcc_assert (TREE_CODE (binfo) == TREE_BINFO);
4174 
4175   BINFO_VTABLE (binfo) = NULL_TREE;
4176   BINFO_BASE_ACCESSES (binfo) = NULL;
4177   BINFO_INHERITANCE_CHAIN (binfo) = NULL_TREE;
4178   BINFO_SUBVTT_INDEX (binfo) = NULL_TREE;
4179 
4180   for (i = 0; VEC_iterate (tree, BINFO_BASE_BINFOS (binfo), i, t); i++)
4181     free_lang_data_in_binfo (t);
4182 }
4183 
4184 
4185 /* Reset all language specific information still present in TYPE.  */
4186 
4187 static void
4188 free_lang_data_in_type (tree type)
4189 {
4190   gcc_assert (TYPE_P (type));
4191 
4192   /* Give the FE a chance to remove its own data first.  */
4193   lang_hooks.free_lang_data (type);
4194 
4195   TREE_LANG_FLAG_0 (type) = 0;
4196   TREE_LANG_FLAG_1 (type) = 0;
4197   TREE_LANG_FLAG_2 (type) = 0;
4198   TREE_LANG_FLAG_3 (type) = 0;
4199   TREE_LANG_FLAG_4 (type) = 0;
4200   TREE_LANG_FLAG_5 (type) = 0;
4201   TREE_LANG_FLAG_6 (type) = 0;
4202 
4203   if (TREE_CODE (type) == FUNCTION_TYPE)
4204     {
4205       /* Remove the const and volatile qualifiers from arguments.  The
4206 	 C++ front end removes them, but the C front end does not,
4207 	 leading to false ODR violation errors when merging two
4208 	 instances of the same function signature compiled by
4209 	 different front ends.  */
4210       tree p;
4211 
4212       for (p = TYPE_ARG_TYPES (type); p; p = TREE_CHAIN (p))
4213 	{
4214 	  tree arg_type = TREE_VALUE (p);
4215 
4216 	  if (TYPE_READONLY (arg_type) || TYPE_VOLATILE (arg_type))
4217 	    {
4218 	      int quals = TYPE_QUALS (arg_type)
4219 			  & ~TYPE_QUAL_CONST
4220 			  & ~TYPE_QUAL_VOLATILE;
4221 	      TREE_VALUE (p) = build_qualified_type (arg_type, quals);
4222 	      free_lang_data_in_type (TREE_VALUE (p));
4223 	    }
4224 	}
4225     }
4226 
4227   /* Remove members that are not actually FIELD_DECLs from the field
4228      list of an aggregate.  These occur in C++.  */
4229   if (RECORD_OR_UNION_TYPE_P (type))
4230     {
4231       tree prev, member;
4232 
4233       /* Note that TYPE_FIELDS can be shared across distinct
4234 	 TREE_TYPEs.  Therefore, if the first field of TYPE_FIELDS is
4235 	 to be removed, we cannot set its TREE_CHAIN to NULL.
4236 	 Otherwise, we would not be able to find all the other fields
4237 	 in the other instances of this TREE_TYPE.
4238 
4239 	 This was causing an ICE in testsuite/g++.dg/lto/20080915.C.  */
4240       prev = NULL_TREE;
4241       member = TYPE_FIELDS (type);
4242       while (member)
4243 	{
4244 	  if (TREE_CODE (member) == FIELD_DECL)
4245 	    {
4246 	      if (prev)
4247 		TREE_CHAIN (prev) = member;
4248 	      else
4249 		TYPE_FIELDS (type) = member;
4250 	      prev = member;
4251 	    }
4252 
4253 	  member = TREE_CHAIN (member);
4254 	}
4255 
4256       if (prev)
4257 	TREE_CHAIN (prev) = NULL_TREE;
4258       else
4259 	TYPE_FIELDS (type) = NULL_TREE;
4260 
4261       TYPE_METHODS (type) = NULL_TREE;
4262       if (TYPE_BINFO (type))
4263 	free_lang_data_in_binfo (TYPE_BINFO (type));
4264     }
4265   else
4266     {
4267       /* For non-aggregate types, clear out the language slot (which
4268 	 overloads TYPE_BINFO).  */
4269       TYPE_LANG_SLOT_1 (type) = NULL_TREE;
4270     }
4271 
4272   if (debug_info_level < DINFO_LEVEL_TERSE
4273       || (TYPE_CONTEXT (type)
4274 	  && TREE_CODE (TYPE_CONTEXT (type)) != FUNCTION_DECL
4275 	  && TREE_CODE (TYPE_CONTEXT (type)) != NAMESPACE_DECL))
4276     TYPE_CONTEXT (type) = NULL_TREE;
4277 
4278   if (debug_info_level < DINFO_LEVEL_TERSE)
4279     TYPE_STUB_DECL (type) = NULL_TREE;
4280 }
4281 
4282 
4283 /* Return true if DECL may need an assembler name to be set.  */
4284 
4285 static inline bool
4286 need_assembler_name_p (tree decl)
4287 {
4288   /* Only FUNCTION_DECLs and VAR_DECLs are considered.  */
4289   if (TREE_CODE (decl) != FUNCTION_DECL
4290       && TREE_CODE (decl) != VAR_DECL)
4291     return false;
4292 
4293   /* If DECL already has its assembler name set, it does not need a
4294      new one.  */
4295   if (!HAS_DECL_ASSEMBLER_NAME_P (decl)
4296       || DECL_ASSEMBLER_NAME_SET_P (decl))
4297     return false;
4298 
4299   /* Abstract decls do not need an assembler name.  */
4300   if (DECL_ABSTRACT (decl))
4301     return false;
4302 
4303   /* For VAR_DECLs, only static, public and external symbols need an
4304      assembler name.  */
4305   if (TREE_CODE (decl) == VAR_DECL
4306       && !TREE_STATIC (decl)
4307       && !TREE_PUBLIC (decl)
4308       && !DECL_EXTERNAL (decl))
4309     return false;
4310 
4311   if (TREE_CODE (decl) == FUNCTION_DECL)
4312     {
4313       /* Do not set assembler name on builtins.  Allow RTL expansion to
4314 	 decide whether to expand inline or via a regular call.  */
4315       if (DECL_BUILT_IN (decl)
4316 	  && DECL_BUILT_IN_CLASS (decl) != BUILT_IN_FRONTEND)
4317 	return false;
4318 
4319       /* Functions represented in the callgraph need an assembler name.  */
4320       if (cgraph_get_node (decl) != NULL)
4321 	return true;
4322 
4323       /* Unused and not public functions don't need an assembler name.  */
4324       if (!TREE_USED (decl) && !TREE_PUBLIC (decl))
4325 	return false;
4326     }
4327 
4328   return true;
4329 }
4330 
4331 
4332 /* Remove all the non-variable decls from BLOCK.  LOCALS is the set of
4333    variables in DECL_STRUCT_FUNCTION (FN)->local_decls.  Every decl
4334    in BLOCK that is not in LOCALS is removed.  */
4335 
4336 static void
4337 free_lang_data_in_block (tree fn, tree block, struct pointer_set_t *locals)
4338 {
4339   tree *tp, t;
4340 
4341   tp = &BLOCK_VARS (block);
4342   while (*tp)
4343     {
4344       if (!pointer_set_contains (locals, *tp))
4345 	*tp = TREE_CHAIN (*tp);
4346       else
4347 	tp = &TREE_CHAIN (*tp);
4348     }
4349 
4350   for (t = BLOCK_SUBBLOCKS (block); t; t = BLOCK_CHAIN (t))
4351     free_lang_data_in_block (fn, t, locals);
4352 }
4353 
4354 
4355 /* Reset all language specific information still present in symbol
4356    DECL.  */
4357 
4358 static void
4359 free_lang_data_in_decl (tree decl)
4360 {
4361   gcc_assert (DECL_P (decl));
4362 
4363   /* Give the FE a chance to remove its own data first.  */
4364   lang_hooks.free_lang_data (decl);
4365 
4366   TREE_LANG_FLAG_0 (decl) = 0;
4367   TREE_LANG_FLAG_1 (decl) = 0;
4368   TREE_LANG_FLAG_2 (decl) = 0;
4369   TREE_LANG_FLAG_3 (decl) = 0;
4370   TREE_LANG_FLAG_4 (decl) = 0;
4371   TREE_LANG_FLAG_5 (decl) = 0;
4372   TREE_LANG_FLAG_6 (decl) = 0;
4373 
4374   /* Identifiers need not have a type.  */
4375   if (DECL_NAME (decl))
4376     TREE_TYPE (DECL_NAME (decl)) = NULL_TREE;
4377 
4378   /* Ignore any intervening types, because we are going to clear their
4379      TYPE_CONTEXT fields.  */
4380   if (TREE_CODE (decl) != FIELD_DECL
4381       && TREE_CODE (decl) != FUNCTION_DECL)
4382     DECL_CONTEXT (decl) = decl_function_context (decl);
4383 
4384   if (DECL_CONTEXT (decl)
4385       && TREE_CODE (DECL_CONTEXT (decl)) == NAMESPACE_DECL)
4386     DECL_CONTEXT (decl) = NULL_TREE;
4387 
4388  if (TREE_CODE (decl) == VAR_DECL)
4389    {
4390      tree context = DECL_CONTEXT (decl);
4391 
4392      if (context)
4393        {
4394 	 enum tree_code code = TREE_CODE (context);
4395 	 if (code == FUNCTION_DECL && DECL_ABSTRACT (context))
4396 	   {
4397 	     /* Do not clear the decl context here, that will promote
4398 	        all vars to global ones.  */
4399 	     DECL_INITIAL (decl) = NULL_TREE;
4400 	   }
4401 
4402 	 if (TREE_STATIC (decl))
4403 	   DECL_CONTEXT (decl) = NULL_TREE;
4404        }
4405    }
4406 
4407  /* ???  We could free non-constant DECL_SIZE, DECL_SIZE_UNIT
4408     and DECL_FIELD_OFFSET.  But it's cheap enough to not do
4409     that and refrain from adding workarounds to dwarf2out.c  */
4410 
4411  /* DECL_FCONTEXT is only used for debug info generation.  */
4412  if (TREE_CODE (decl) == FIELD_DECL
4413      && debug_info_level < DINFO_LEVEL_TERSE)
4414    DECL_FCONTEXT (decl) = NULL_TREE;
4415 
4416  if (TREE_CODE (decl) == FUNCTION_DECL)
4417     {
4418       if (gimple_has_body_p (decl))
4419 	{
4420 	  tree t;
4421 	  struct pointer_set_t *locals;
4422 
4423 	  /* If DECL has a gimple body, then the context for its
4424 	     arguments must be DECL.  Otherwise, it doesn't really
4425 	     matter, as we will not be emitting any code for DECL.  In
4426 	     general, there may be other instances of DECL created by
4427 	     the front end and since PARM_DECLs are generally shared,
4428 	     their DECL_CONTEXT changes as the replicas of DECL are
4429 	     created.  The only time where DECL_CONTEXT is important
4430 	     is for the FUNCTION_DECLs that have a gimple body (since
4431 	     the PARM_DECL will be used in the function's body).  */
4432 	  for (t = DECL_ARGUMENTS (decl); t; t = TREE_CHAIN (t))
4433 	    DECL_CONTEXT (t) = decl;
4434 
4435 	  /* Collect all the symbols declared in DECL.  */
4436 	  locals = pointer_set_create ();
4437 	  t = DECL_STRUCT_FUNCTION (decl)->local_decls;
4438 	  for (; t; t = TREE_CHAIN (t))
4439 	    {
4440 	      pointer_set_insert (locals, TREE_VALUE (t));
4441 
4442 	      /* All the local symbols should have DECL as their
4443 		 context.  */
4444 	      DECL_CONTEXT (TREE_VALUE (t)) = decl;
4445 	    }
4446 
4447 	  /* Get rid of any decl not in local_decls.  */
4448 	  free_lang_data_in_block (decl, DECL_INITIAL (decl), locals);
4449 
4450 	  pointer_set_destroy (locals);
4451 	}
4452 
4453       /* DECL_SAVED_TREE holds the GENERIC representation for DECL.
4454 	 At this point, it is not needed anymore.  */
4455       DECL_SAVED_TREE (decl) = NULL_TREE;
4456     }
4457   else if (TREE_CODE (decl) == VAR_DECL)
4458     {
4459       tree expr = DECL_DEBUG_EXPR (decl);
4460       if (expr
4461 	  && TREE_CODE (expr) == VAR_DECL
4462 	  && !TREE_STATIC (expr) && !DECL_EXTERNAL (expr))
4463 	SET_DECL_DEBUG_EXPR (decl, NULL_TREE);
4464 
4465       if (DECL_EXTERNAL (decl)
4466 	  && (!TREE_STATIC (decl) || !TREE_READONLY (decl)))
4467 	DECL_INITIAL (decl) = NULL_TREE;
4468     }
4469   else if (TREE_CODE (decl) == TYPE_DECL)
4470     {
4471       DECL_INITIAL (decl) = NULL_TREE;
4472 
4473       /* DECL_CONTEXT is overloaded as DECL_FIELD_CONTEXT for
4474 	 FIELD_DECLs, which should be preserved.  Otherwise,
4475 	 we shouldn't be concerned with source-level lexical
4476 	 nesting beyond this point. */
4477       DECL_CONTEXT (decl) = NULL_TREE;
4478     }
4479 }
4480 
4481 
4482 /* Data used when collecting DECLs and TYPEs for language data removal.  */
4483 
4484 struct free_lang_data_d
4485 {
4486   /* Worklist to avoid excessive recursion.  */
4487   VEC(tree,heap) *worklist;
4488 
4489   /* Set of traversed objects.  Used to avoid duplicate visits.  */
4490   struct pointer_set_t *pset;
4491 
4492   /* Array of symbols to process with free_lang_data_in_decl.  */
4493   VEC(tree,heap) *decls;
4494 
4495   /* Array of types to process with free_lang_data_in_type.  */
4496   VEC(tree,heap) *types;
4497 };
4498 
4499 
4500 /* Save all language fields needed to generate proper debug information
4501    for DECL.  This saves most fields cleared out by free_lang_data_in_decl.  */
4502 
4503 static void
4504 save_debug_info_for_decl (tree t)
4505 {
4506   /*struct saved_debug_info_d *sdi;*/
4507 
4508   gcc_assert (debug_info_level > DINFO_LEVEL_TERSE && t && DECL_P (t));
4509 
4510   /* FIXME.  Partial implementation for saving debug info removed.  */
4511 }
4512 
4513 
4514 /* Save all language fields needed to generate proper debug information
4515    for TYPE.  This saves most fields cleared out by free_lang_data_in_type.  */
4516 
4517 static void
4518 save_debug_info_for_type (tree t)
4519 {
4520   /*struct saved_debug_info_d *sdi;*/
4521 
4522   gcc_assert (debug_info_level > DINFO_LEVEL_TERSE && t && TYPE_P (t));
4523 
4524   /* FIXME.  Partial implementation for saving debug info removed.  */
4525 }
4526 
4527 
4528 /* Add type or decl T to one of the list of tree nodes that need their
4529    language data removed.  The lists are held inside FLD.  */
4530 
4531 static void
4532 add_tree_to_fld_list (tree t, struct free_lang_data_d *fld)
4533 {
4534   if (DECL_P (t))
4535     {
4536       VEC_safe_push (tree, heap, fld->decls, t);
4537       if (debug_info_level > DINFO_LEVEL_TERSE)
4538 	save_debug_info_for_decl (t);
4539     }
4540   else if (TYPE_P (t))
4541     {
4542       VEC_safe_push (tree, heap, fld->types, t);
4543       if (debug_info_level > DINFO_LEVEL_TERSE)
4544 	save_debug_info_for_type (t);
4545     }
4546   else
4547     gcc_unreachable ();
4548 }
4549 
4550 /* Push tree node T into FLD->WORKLIST.  */
4551 
4552 static inline void
4553 fld_worklist_push (tree t, struct free_lang_data_d *fld)
4554 {
4555   if (t && !is_lang_specific (t) && !pointer_set_contains (fld->pset, t))
4556     VEC_safe_push (tree, heap, fld->worklist, (t));
4557 }
4558 
4559 
4560 /* Operand callback helper for free_lang_data_in_node.  *TP is the
4561    subtree operand being considered.  */
4562 
4563 static tree
4564 find_decls_types_r (tree *tp, int *ws, void *data)
4565 {
4566   tree t = *tp;
4567   struct free_lang_data_d *fld = (struct free_lang_data_d *) data;
4568 
4569   if (TREE_CODE (t) == TREE_LIST)
4570     return NULL_TREE;
4571 
4572   /* Language specific nodes will be removed, so there is no need
4573      to gather anything under them.  */
4574   if (is_lang_specific (t))
4575     {
4576       *ws = 0;
4577       return NULL_TREE;
4578     }
4579 
4580   if (DECL_P (t))
4581     {
4582       /* Note that walk_tree does not traverse every possible field in
4583 	 decls, so we have to do our own traversals here.  */
4584       add_tree_to_fld_list (t, fld);
4585 
4586       fld_worklist_push (DECL_NAME (t), fld);
4587       fld_worklist_push (DECL_CONTEXT (t), fld);
4588       fld_worklist_push (DECL_SIZE (t), fld);
4589       fld_worklist_push (DECL_SIZE_UNIT (t), fld);
4590 
4591       /* We are going to remove everything under DECL_INITIAL for
4592 	 TYPE_DECLs.  No point walking them.  */
4593       if (TREE_CODE (t) != TYPE_DECL)
4594 	fld_worklist_push (DECL_INITIAL (t), fld);
4595 
4596       fld_worklist_push (DECL_ATTRIBUTES (t), fld);
4597       fld_worklist_push (DECL_ABSTRACT_ORIGIN (t), fld);
4598 
4599       if (TREE_CODE (t) == FUNCTION_DECL)
4600 	{
4601 	  fld_worklist_push (DECL_ARGUMENTS (t), fld);
4602 	  fld_worklist_push (DECL_RESULT (t), fld);
4603 	}
4604       else if (TREE_CODE (t) == TYPE_DECL)
4605 	{
4606 	  fld_worklist_push (DECL_ARGUMENT_FLD (t), fld);
4607 	  fld_worklist_push (DECL_VINDEX (t), fld);
4608 	}
4609       else if (TREE_CODE (t) == FIELD_DECL)
4610 	{
4611 	  fld_worklist_push (DECL_FIELD_OFFSET (t), fld);
4612 	  fld_worklist_push (DECL_BIT_FIELD_TYPE (t), fld);
4613 	  fld_worklist_push (DECL_QUALIFIER (t), fld);
4614 	  fld_worklist_push (DECL_FIELD_BIT_OFFSET (t), fld);
4615 	  fld_worklist_push (DECL_FCONTEXT (t), fld);
4616 	}
4617       else if (TREE_CODE (t) == VAR_DECL)
4618 	{
4619 	  fld_worklist_push (DECL_SECTION_NAME (t), fld);
4620 	  fld_worklist_push (DECL_COMDAT_GROUP (t), fld);
4621 	}
4622 
4623       if (TREE_CODE (t) != FIELD_DECL)
4624 	fld_worklist_push (TREE_CHAIN (t), fld);
4625       *ws = 0;
4626     }
4627   else if (TYPE_P (t))
4628     {
4629       /* Note that walk_tree does not traverse every possible field in
4630 	 types, so we have to do our own traversals here.  */
4631       add_tree_to_fld_list (t, fld);
4632 
4633       if (!RECORD_OR_UNION_TYPE_P (t))
4634 	fld_worklist_push (TYPE_CACHED_VALUES (t), fld);
4635       fld_worklist_push (TYPE_SIZE (t), fld);
4636       fld_worklist_push (TYPE_SIZE_UNIT (t), fld);
4637       fld_worklist_push (TYPE_ATTRIBUTES (t), fld);
4638       fld_worklist_push (TYPE_POINTER_TO (t), fld);
4639       fld_worklist_push (TYPE_REFERENCE_TO (t), fld);
4640       fld_worklist_push (TYPE_NAME (t), fld);
4641       fld_worklist_push (TYPE_MINVAL (t), fld);
4642       if (!RECORD_OR_UNION_TYPE_P (t))
4643 	fld_worklist_push (TYPE_MAXVAL (t), fld);
4644       fld_worklist_push (TYPE_MAIN_VARIANT (t), fld);
4645       fld_worklist_push (TYPE_NEXT_VARIANT (t), fld);
4646       fld_worklist_push (TYPE_CONTEXT (t), fld);
4647       fld_worklist_push (TYPE_CANONICAL (t), fld);
4648 
4649       if (RECORD_OR_UNION_TYPE_P (t) && TYPE_BINFO (t))
4650 	{
4651 	  unsigned i;
4652 	  tree tem;
4653 	  for (i = 0; VEC_iterate (tree, BINFO_BASE_BINFOS (TYPE_BINFO (t)),
4654 				   i, tem); ++i)
4655 	    fld_worklist_push (TREE_TYPE (tem), fld);
4656 	  tem = BINFO_VIRTUALS (TYPE_BINFO (t));
4657 	  if (tem
4658 	      /* The Java FE overloads BINFO_VIRTUALS for its own purpose.  */
4659 	      && TREE_CODE (tem) == TREE_LIST)
4660 	    do
4661 	      {
4662 		fld_worklist_push (TREE_VALUE (tem), fld);
4663 		tem = TREE_CHAIN (tem);
4664 	      }
4665 	    while (tem);
4666 	}
4667       if (RECORD_OR_UNION_TYPE_P (t))
4668 	{
4669 	  tree tem;
4670 	  /* Push all TYPE_FIELDS - there can be interleaving interesting
4671 	     and non-interesting things.  */
4672 	  tem = TYPE_FIELDS (t);
4673 	  while (tem)
4674 	    {
4675 	      if (TREE_CODE (tem) == FIELD_DECL)
4676 		fld_worklist_push (tem, fld);
4677 	      tem = TREE_CHAIN (tem);
4678 	    }
4679 	}
4680 
4681       fld_worklist_push (TREE_CHAIN (t), fld);
4682       *ws = 0;
4683     }
4684   else if (TREE_CODE (t) == BLOCK)
4685     {
4686       tree tem;
4687       for (tem = BLOCK_VARS (t); tem; tem = TREE_CHAIN (tem))
4688 	fld_worklist_push (tem, fld);
4689       for (tem = BLOCK_SUBBLOCKS (t); tem; tem = BLOCK_CHAIN (tem))
4690 	fld_worklist_push (tem, fld);
4691       fld_worklist_push (BLOCK_ABSTRACT_ORIGIN (t), fld);
4692     }
4693 
4694   fld_worklist_push (TREE_TYPE (t), fld);
4695 
4696   return NULL_TREE;
4697 }
4698 
4699 
4700 /* Find decls and types in T.  */
4701 
4702 static void
4703 find_decls_types (tree t, struct free_lang_data_d *fld)
4704 {
4705   while (1)
4706     {
4707       if (!pointer_set_contains (fld->pset, t))
4708 	walk_tree (&t, find_decls_types_r, fld, fld->pset);
4709       if (VEC_empty (tree, fld->worklist))
4710 	break;
4711       t = VEC_pop (tree, fld->worklist);
4712     }
4713 }
4714 
4715 /* Translate all the types in LIST with the corresponding runtime
4716    types.  */
4717 
4718 static tree
4719 get_eh_types_for_runtime (tree list)
4720 {
4721   tree head, prev;
4722 
4723   if (list == NULL_TREE)
4724     return NULL_TREE;
4725 
4726   head = build_tree_list (0, lookup_type_for_runtime (TREE_VALUE (list)));
4727   prev = head;
4728   list = TREE_CHAIN (list);
4729   while (list)
4730     {
4731       tree n = build_tree_list (0, lookup_type_for_runtime (TREE_VALUE (list)));
4732       TREE_CHAIN (prev) = n;
4733       prev = TREE_CHAIN (prev);
4734       list = TREE_CHAIN (list);
4735     }
4736 
4737   return head;
4738 }
4739 
4740 
4741 /* Find decls and types referenced in EH region R and store them in
4742    FLD->DECLS and FLD->TYPES.  */
4743 
4744 static void
4745 find_decls_types_in_eh_region (eh_region r, struct free_lang_data_d *fld)
4746 {
4747   switch (r->type)
4748     {
4749     case ERT_CLEANUP:
4750       break;
4751 
4752     case ERT_TRY:
4753       {
4754 	eh_catch c;
4755 
4756 	/* The types referenced in each catch must first be changed to the
4757 	   EH types used at runtime.  This removes references to FE types
4758 	   in the region.  */
4759 	for (c = r->u.eh_try.first_catch; c ; c = c->next_catch)
4760 	  {
4761 	    c->type_list = get_eh_types_for_runtime (c->type_list);
4762 	    walk_tree (&c->type_list, find_decls_types_r, fld, fld->pset);
4763 	  }
4764       }
4765       break;
4766 
4767     case ERT_ALLOWED_EXCEPTIONS:
4768       r->u.allowed.type_list
4769 	= get_eh_types_for_runtime (r->u.allowed.type_list);
4770       walk_tree (&r->u.allowed.type_list, find_decls_types_r, fld, fld->pset);
4771       break;
4772 
4773     case ERT_MUST_NOT_THROW:
4774       walk_tree (&r->u.must_not_throw.failure_decl,
4775 		 find_decls_types_r, fld, fld->pset);
4776       break;
4777     }
4778 }
4779 
4780 
4781 /* Find decls and types referenced in cgraph node N and store them in
4782    FLD->DECLS and FLD->TYPES.  Unlike pass_referenced_vars, this will
4783    look for *every* kind of DECL and TYPE node reachable from N,
4784    including those embedded inside types and decls (i.e,, TYPE_DECLs,
4785    NAMESPACE_DECLs, etc).  */
4786 
4787 static void
4788 find_decls_types_in_node (struct cgraph_node *n, struct free_lang_data_d *fld)
4789 {
4790   basic_block bb;
4791   struct function *fn;
4792   tree t;
4793 
4794   find_decls_types (n->decl, fld);
4795 
4796   if (!gimple_has_body_p (n->decl))
4797     return;
4798 
4799   gcc_assert (current_function_decl == NULL_TREE && cfun == NULL);
4800 
4801   fn = DECL_STRUCT_FUNCTION (n->decl);
4802 
4803   /* Traverse locals. */
4804   for (t = fn->local_decls; t; t = TREE_CHAIN (t))
4805     find_decls_types (TREE_VALUE (t), fld);
4806 
4807   /* Traverse EH regions in FN.  */
4808   {
4809     eh_region r;
4810     FOR_ALL_EH_REGION_FN (r, fn)
4811       find_decls_types_in_eh_region (r, fld);
4812   }
4813 
4814   /* Traverse every statement in FN.  */
4815   FOR_EACH_BB_FN (bb, fn)
4816     {
4817       gimple_stmt_iterator si;
4818       unsigned i;
4819 
4820       for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si))
4821 	{
4822 	  gimple phi = gsi_stmt (si);
4823 
4824 	  for (i = 0; i < gimple_phi_num_args (phi); i++)
4825 	    {
4826 	      tree *arg_p = gimple_phi_arg_def_ptr (phi, i);
4827 	      find_decls_types (*arg_p, fld);
4828 	    }
4829 	}
4830 
4831       for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
4832 	{
4833 	  gimple stmt = gsi_stmt (si);
4834 
4835 	  for (i = 0; i < gimple_num_ops (stmt); i++)
4836 	    {
4837 	      tree arg = gimple_op (stmt, i);
4838 	      find_decls_types (arg, fld);
4839 	    }
4840 	}
4841     }
4842 }
4843 
4844 
4845 /* Find decls and types referenced in varpool node N and store them in
4846    FLD->DECLS and FLD->TYPES.  Unlike pass_referenced_vars, this will
4847    look for *every* kind of DECL and TYPE node reachable from N,
4848    including those embedded inside types and decls (i.e,, TYPE_DECLs,
4849    NAMESPACE_DECLs, etc).  */
4850 
4851 static void
4852 find_decls_types_in_var (struct varpool_node *v, struct free_lang_data_d *fld)
4853 {
4854   find_decls_types (v->decl, fld);
4855 }
4856 
4857 /* If T needs an assembler name, have one created for it.  */
4858 
4859 void
4860 assign_assembler_name_if_neeeded (tree t)
4861 {
4862   if (need_assembler_name_p (t))
4863     {
4864       /* When setting DECL_ASSEMBLER_NAME, the C++ mangler may emit
4865 	 diagnostics that use input_location to show locus
4866 	 information.  The problem here is that, at this point,
4867 	 input_location is generally anchored to the end of the file
4868 	 (since the parser is long gone), so we don't have a good
4869 	 position to pin it to.
4870 
4871 	 To alleviate this problem, this uses the location of T's
4872 	 declaration.  Examples of this are
4873 	 testsuite/g++.dg/template/cond2.C and
4874 	 testsuite/g++.dg/template/pr35240.C.  */
4875       location_t saved_location = input_location;
4876       input_location = DECL_SOURCE_LOCATION (t);
4877 
4878       decl_assembler_name (t);
4879 
4880       input_location = saved_location;
4881     }
4882 }
4883 
4884 
4885 /* Free language specific information for every operand and expression
4886    in every node of the call graph.  This process operates in three stages:
4887 
4888    1- Every callgraph node and varpool node is traversed looking for
4889       decls and types embedded in them.  This is a more exhaustive
4890       search than that done by find_referenced_vars, because it will
4891       also collect individual fields, decls embedded in types, etc.
4892 
4893    2- All the decls found are sent to free_lang_data_in_decl.
4894 
4895    3- All the types found are sent to free_lang_data_in_type.
4896 
4897    The ordering between decls and types is important because
4898    free_lang_data_in_decl sets assembler names, which includes
4899    mangling.  So types cannot be freed up until assembler names have
4900    been set up.  */
4901 
4902 static void
4903 free_lang_data_in_cgraph (void)
4904 {
4905   struct cgraph_node *n;
4906   struct varpool_node *v;
4907   struct free_lang_data_d fld;
4908   tree t;
4909   unsigned i;
4910   alias_pair *p;
4911 
4912   /* Initialize sets and arrays to store referenced decls and types.  */
4913   fld.pset = pointer_set_create ();
4914   fld.worklist = NULL;
4915   fld.decls = VEC_alloc (tree, heap, 100);
4916   fld.types = VEC_alloc (tree, heap, 100);
4917 
4918   /* Find decls and types in the body of every function in the callgraph.  */
4919   for (n = cgraph_nodes; n; n = n->next)
4920     find_decls_types_in_node (n, &fld);
4921 
4922   for (i = 0; VEC_iterate (alias_pair, alias_pairs, i, p); i++)
4923     find_decls_types (p->decl, &fld);
4924 
4925   /* Find decls and types in every varpool symbol.  */
4926   for (v = varpool_nodes_queue; v; v = v->next_needed)
4927     find_decls_types_in_var (v, &fld);
4928 
4929   /* Set the assembler name on every decl found.  We need to do this
4930      now because free_lang_data_in_decl will invalidate data needed
4931      for mangling.  This breaks mangling on interdependent decls.  */
4932   for (i = 0; VEC_iterate (tree, fld.decls, i, t); i++)
4933     assign_assembler_name_if_neeeded (t);
4934 
4935   /* Traverse every decl found freeing its language data.  */
4936   for (i = 0; VEC_iterate (tree, fld.decls, i, t); i++)
4937     free_lang_data_in_decl (t);
4938 
4939   /* Traverse every type found freeing its language data.  */
4940   for (i = 0; VEC_iterate (tree, fld.types, i, t); i++)
4941     free_lang_data_in_type (t);
4942 
4943   pointer_set_destroy (fld.pset);
4944   VEC_free (tree, heap, fld.worklist);
4945   VEC_free (tree, heap, fld.decls);
4946   VEC_free (tree, heap, fld.types);
4947 }
4948 
4949 
4950 /* Free resources that are used by FE but are not needed once they are done. */
4951 
4952 static unsigned
4953 free_lang_data (void)
4954 {
4955   unsigned i;
4956 
4957   /* If we are the LTO frontend we have freed lang-specific data already.  */
4958   if (in_lto_p
4959       || !flag_generate_lto)
4960     return 0;
4961 
4962   /* Allocate and assign alias sets to the standard integer types
4963      while the slots are still in the way the frontends generated them.  */
4964   for (i = 0; i < itk_none; ++i)
4965     if (integer_types[i])
4966       TYPE_ALIAS_SET (integer_types[i]) = get_alias_set (integer_types[i]);
4967 
4968   /* Traverse the IL resetting language specific information for
4969      operands, expressions, etc.  */
4970   free_lang_data_in_cgraph ();
4971 
4972   /* Create gimple variants for common types.  */
4973   ptrdiff_type_node = integer_type_node;
4974   fileptr_type_node = ptr_type_node;
4975   if (TREE_CODE (boolean_type_node) != BOOLEAN_TYPE
4976       || (TYPE_MODE (boolean_type_node)
4977 	  != mode_for_size (BOOL_TYPE_SIZE, MODE_INT, 0))
4978       || TYPE_PRECISION (boolean_type_node) != 1
4979       || !TYPE_UNSIGNED (boolean_type_node))
4980     {
4981       boolean_type_node = make_unsigned_type (BOOL_TYPE_SIZE);
4982       TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
4983       TYPE_MAX_VALUE (boolean_type_node) = build_int_cst (boolean_type_node, 1);
4984       TYPE_PRECISION (boolean_type_node) = 1;
4985       boolean_false_node = TYPE_MIN_VALUE (boolean_type_node);
4986       boolean_true_node = TYPE_MAX_VALUE (boolean_type_node);
4987     }
4988 
4989   /* Unify char_type_node with its properly signed variant.  */
4990   if (TYPE_UNSIGNED (char_type_node))
4991     unsigned_char_type_node = char_type_node;
4992   else
4993     signed_char_type_node = char_type_node;
4994 
4995   /* Reset some langhooks.  Do not reset types_compatible_p, it may
4996      still be used indirectly via the get_alias_set langhook.  */
4997   lang_hooks.callgraph.analyze_expr = NULL;
4998   lang_hooks.dwarf_name = lhd_dwarf_name;
4999   lang_hooks.decl_printable_name = gimple_decl_printable_name;
5000   lang_hooks.set_decl_assembler_name = lhd_set_decl_assembler_name;
5001   lang_hooks.fold_obj_type_ref = gimple_fold_obj_type_ref;
5002 
5003   /* Reset diagnostic machinery.  */
5004   diagnostic_starter (global_dc) = default_diagnostic_starter;
5005   diagnostic_finalizer (global_dc) = default_diagnostic_finalizer;
5006   diagnostic_format_decoder (global_dc) = default_tree_printer;
5007 
5008   return 0;
5009 }
5010 
5011 
5012 struct simple_ipa_opt_pass pass_ipa_free_lang_data =
5013 {
5014  {
5015   SIMPLE_IPA_PASS,
5016   "*free_lang_data",			/* name */
5017   NULL,					/* gate */
5018   free_lang_data,			/* execute */
5019   NULL,					/* sub */
5020   NULL,					/* next */
5021   0,					/* static_pass_number */
5022   TV_IPA_FREE_LANG_DATA,		/* tv_id */
5023   0,	                                /* properties_required */
5024   0,					/* properties_provided */
5025   0,					/* properties_destroyed */
5026   0,					/* todo_flags_start */
5027   TODO_ggc_collect			/* todo_flags_finish */
5028  }
5029 };
5030 
5031 /* Return nonzero if IDENT is a valid name for attribute ATTR,
5032    or zero if not.
5033 
5034    We try both `text' and `__text__', ATTR may be either one.  */
5035 /* ??? It might be a reasonable simplification to require ATTR to be only
5036    `text'.  One might then also require attribute lists to be stored in
5037    their canonicalized form.  */
5038 
5039 static int
5040 is_attribute_with_length_p (const char *attr, int attr_len, const_tree ident)
5041 {
5042   int ident_len;
5043   const char *p;
5044 
5045   if (TREE_CODE (ident) != IDENTIFIER_NODE)
5046     return 0;
5047 
5048   p = IDENTIFIER_POINTER (ident);
5049   ident_len = IDENTIFIER_LENGTH (ident);
5050 
5051   if (ident_len == attr_len
5052       && strcmp (attr, p) == 0)
5053     return 1;
5054 
5055   /* If ATTR is `__text__', IDENT must be `text'; and vice versa.  */
5056   if (attr[0] == '_')
5057     {
5058       gcc_assert (attr[1] == '_');
5059       gcc_assert (attr[attr_len - 2] == '_');
5060       gcc_assert (attr[attr_len - 1] == '_');
5061       if (ident_len == attr_len - 4
5062 	  && strncmp (attr + 2, p, attr_len - 4) == 0)
5063 	return 1;
5064     }
5065   else
5066     {
5067       if (ident_len == attr_len + 4
5068 	  && p[0] == '_' && p[1] == '_'
5069 	  && p[ident_len - 2] == '_' && p[ident_len - 1] == '_'
5070 	  && strncmp (attr, p + 2, attr_len) == 0)
5071 	return 1;
5072     }
5073 
5074   return 0;
5075 }
5076 
5077 /* Return nonzero if IDENT is a valid name for attribute ATTR,
5078    or zero if not.
5079 
5080    We try both `text' and `__text__', ATTR may be either one.  */
5081 
5082 int
5083 is_attribute_p (const char *attr, const_tree ident)
5084 {
5085   return is_attribute_with_length_p (attr, strlen (attr), ident);
5086 }
5087 
5088 /* Given an attribute name and a list of attributes, return a pointer to the
5089    attribute's list element if the attribute is part of the list, or NULL_TREE
5090    if not found.  If the attribute appears more than once, this only
5091    returns the first occurrence; the TREE_CHAIN of the return value should
5092    be passed back in if further occurrences are wanted.  */
5093 
5094 tree
5095 lookup_attribute (const char *attr_name, tree list)
5096 {
5097   tree l;
5098   size_t attr_len = strlen (attr_name);
5099 
5100   for (l = list; l; l = TREE_CHAIN (l))
5101     {
5102       gcc_assert (TREE_CODE (TREE_PURPOSE (l)) == IDENTIFIER_NODE);
5103       if (is_attribute_with_length_p (attr_name, attr_len, TREE_PURPOSE (l)))
5104 	return l;
5105     }
5106   return NULL_TREE;
5107 }
5108 
5109 /* Remove any instances of attribute ATTR_NAME in LIST and return the
5110    modified list.  */
5111 
5112 tree
5113 remove_attribute (const char *attr_name, tree list)
5114 {
5115   tree *p;
5116   size_t attr_len = strlen (attr_name);
5117 
5118   for (p = &list; *p; )
5119     {
5120       tree l = *p;
5121       gcc_assert (TREE_CODE (TREE_PURPOSE (l)) == IDENTIFIER_NODE);
5122       if (is_attribute_with_length_p (attr_name, attr_len, TREE_PURPOSE (l)))
5123 	*p = TREE_CHAIN (l);
5124       else
5125 	p = &TREE_CHAIN (l);
5126     }
5127 
5128   return list;
5129 }
5130 
5131 /* Return an attribute list that is the union of a1 and a2.  */
5132 
5133 tree
5134 merge_attributes (tree a1, tree a2)
5135 {
5136   tree attributes;
5137 
5138   /* Either one unset?  Take the set one.  */
5139 
5140   if ((attributes = a1) == 0)
5141     attributes = a2;
5142 
5143   /* One that completely contains the other?  Take it.  */
5144 
5145   else if (a2 != 0 && ! attribute_list_contained (a1, a2))
5146     {
5147       if (attribute_list_contained (a2, a1))
5148 	attributes = a2;
5149       else
5150 	{
5151 	  /* Pick the longest list, and hang on the other list.  */
5152 
5153 	  if (list_length (a1) < list_length (a2))
5154 	    attributes = a2, a2 = a1;
5155 
5156 	  for (; a2 != 0; a2 = TREE_CHAIN (a2))
5157 	    {
5158 	      tree a;
5159 	      for (a = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
5160 					 attributes);
5161 		   a != NULL_TREE;
5162 		   a = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (a2)),
5163 					 TREE_CHAIN (a)))
5164 		{
5165 		  if (TREE_VALUE (a) != NULL
5166 		      && TREE_CODE (TREE_VALUE (a)) == TREE_LIST
5167 		      && TREE_VALUE (a2) != NULL
5168 		      && TREE_CODE (TREE_VALUE (a2)) == TREE_LIST)
5169 		    {
5170 		      if (simple_cst_list_equal (TREE_VALUE (a),
5171 						 TREE_VALUE (a2)) == 1)
5172 			break;
5173 		    }
5174 		  else if (simple_cst_equal (TREE_VALUE (a),
5175 					     TREE_VALUE (a2)) == 1)
5176 		    break;
5177 		}
5178 	      if (a == NULL_TREE)
5179 		{
5180 		  a1 = copy_node (a2);
5181 		  TREE_CHAIN (a1) = attributes;
5182 		  attributes = a1;
5183 		}
5184 	    }
5185 	}
5186     }
5187   return attributes;
5188 }
5189 
5190 /* Given types T1 and T2, merge their attributes and return
5191   the result.  */
5192 
5193 tree
5194 merge_type_attributes (tree t1, tree t2)
5195 {
5196   return merge_attributes (TYPE_ATTRIBUTES (t1),
5197 			   TYPE_ATTRIBUTES (t2));
5198 }
5199 
5200 /* Given decls OLDDECL and NEWDECL, merge their attributes and return
5201    the result.  */
5202 
5203 tree
5204 merge_decl_attributes (tree olddecl, tree newdecl)
5205 {
5206   return merge_attributes (DECL_ATTRIBUTES (olddecl),
5207 			   DECL_ATTRIBUTES (newdecl));
5208 }
5209 
5210 #if TARGET_DLLIMPORT_DECL_ATTRIBUTES
5211 
5212 /* Specialization of merge_decl_attributes for various Windows targets.
5213 
5214    This handles the following situation:
5215 
5216      __declspec (dllimport) int foo;
5217      int foo;
5218 
5219    The second instance of `foo' nullifies the dllimport.  */
5220 
5221 tree
5222 merge_dllimport_decl_attributes (tree old, tree new_tree)
5223 {
5224   tree a;
5225   int delete_dllimport_p = 1;
5226 
5227   /* What we need to do here is remove from `old' dllimport if it doesn't
5228      appear in `new'.  dllimport behaves like extern: if a declaration is
5229      marked dllimport and a definition appears later, then the object
5230      is not dllimport'd.  We also remove a `new' dllimport if the old list
5231      contains dllexport:  dllexport always overrides dllimport, regardless
5232      of the order of declaration.  */
5233   if (!VAR_OR_FUNCTION_DECL_P (new_tree))
5234     delete_dllimport_p = 0;
5235   else if (DECL_DLLIMPORT_P (new_tree)
5236      	   && lookup_attribute ("dllexport", DECL_ATTRIBUTES (old)))
5237     {
5238       DECL_DLLIMPORT_P (new_tree) = 0;
5239       warning (OPT_Wattributes, "%q+D already declared with dllexport attribute: "
5240 	      "dllimport ignored", new_tree);
5241     }
5242   else if (DECL_DLLIMPORT_P (old) && !DECL_DLLIMPORT_P (new_tree))
5243     {
5244       /* Warn about overriding a symbol that has already been used, e.g.:
5245            extern int __attribute__ ((dllimport)) foo;
5246 	   int* bar () {return &foo;}
5247 	   int foo;
5248       */
5249       if (TREE_USED (old))
5250 	{
5251 	  warning (0, "%q+D redeclared without dllimport attribute "
5252 		   "after being referenced with dll linkage", new_tree);
5253 	  /* If we have used a variable's address with dllimport linkage,
5254 	      keep the old DECL_DLLIMPORT_P flag: the ADDR_EXPR using the
5255 	      decl may already have had TREE_CONSTANT computed.
5256 	      We still remove the attribute so that assembler code refers
5257 	      to '&foo rather than '_imp__foo'.  */
5258 	  if (TREE_CODE (old) == VAR_DECL && TREE_ADDRESSABLE (old))
5259 	    DECL_DLLIMPORT_P (new_tree) = 1;
5260 	}
5261 
5262       /* Let an inline definition silently override the external reference,
5263 	 but otherwise warn about attribute inconsistency.  */
5264       else if (TREE_CODE (new_tree) == VAR_DECL
5265 	       || !DECL_DECLARED_INLINE_P (new_tree))
5266 	warning (OPT_Wattributes, "%q+D redeclared without dllimport attribute: "
5267 		  "previous dllimport ignored", new_tree);
5268     }
5269   else
5270     delete_dllimport_p = 0;
5271 
5272   a = merge_attributes (DECL_ATTRIBUTES (old), DECL_ATTRIBUTES (new_tree));
5273 
5274   if (delete_dllimport_p)
5275     {
5276       tree prev, t;
5277       const size_t attr_len = strlen ("dllimport");
5278 
5279       /* Scan the list for dllimport and delete it.  */
5280       for (prev = NULL_TREE, t = a; t; prev = t, t = TREE_CHAIN (t))
5281 	{
5282 	  if (is_attribute_with_length_p ("dllimport", attr_len,
5283 					  TREE_PURPOSE (t)))
5284 	    {
5285 	      if (prev == NULL_TREE)
5286 		a = TREE_CHAIN (a);
5287 	      else
5288 		TREE_CHAIN (prev) = TREE_CHAIN (t);
5289 	      break;
5290 	    }
5291 	}
5292     }
5293 
5294   return a;
5295 }
5296 
5297 /* Handle a "dllimport" or "dllexport" attribute; arguments as in
5298    struct attribute_spec.handler.  */
5299 
5300 tree
5301 handle_dll_attribute (tree * pnode, tree name, tree args, int flags,
5302 		      bool *no_add_attrs)
5303 {
5304   tree node = *pnode;
5305   bool is_dllimport;
5306 
5307   /* These attributes may apply to structure and union types being created,
5308      but otherwise should pass to the declaration involved.  */
5309   if (!DECL_P (node))
5310     {
5311       if (flags & ((int) ATTR_FLAG_DECL_NEXT | (int) ATTR_FLAG_FUNCTION_NEXT
5312 		   | (int) ATTR_FLAG_ARRAY_NEXT))
5313 	{
5314 	  *no_add_attrs = true;
5315 	  return tree_cons (name, args, NULL_TREE);
5316 	}
5317       if (TREE_CODE (node) == RECORD_TYPE
5318 	  || TREE_CODE (node) == UNION_TYPE)
5319 	{
5320 	  node = TYPE_NAME (node);
5321 	  if (!node)
5322 	    return NULL_TREE;
5323 	}
5324       else
5325 	{
5326 	  warning (OPT_Wattributes, "%qE attribute ignored",
5327 		   name);
5328 	  *no_add_attrs = true;
5329 	  return NULL_TREE;
5330 	}
5331     }
5332 
5333   if (TREE_CODE (node) != FUNCTION_DECL
5334       && TREE_CODE (node) != VAR_DECL
5335       && TREE_CODE (node) != TYPE_DECL)
5336     {
5337       *no_add_attrs = true;
5338       warning (OPT_Wattributes, "%qE attribute ignored",
5339 	       name);
5340       return NULL_TREE;
5341     }
5342 
5343   if (TREE_CODE (node) == TYPE_DECL
5344       && TREE_CODE (TREE_TYPE (node)) != RECORD_TYPE
5345       && TREE_CODE (TREE_TYPE (node)) != UNION_TYPE)
5346     {
5347       *no_add_attrs = true;
5348       warning (OPT_Wattributes, "%qE attribute ignored",
5349 	       name);
5350       return NULL_TREE;
5351     }
5352 
5353   is_dllimport = is_attribute_p ("dllimport", name);
5354 
5355   /* Report error on dllimport ambiguities seen now before they cause
5356      any damage.  */
5357   if (is_dllimport)
5358     {
5359       /* Honor any target-specific overrides. */
5360       if (!targetm.valid_dllimport_attribute_p (node))
5361 	*no_add_attrs = true;
5362 
5363      else if (TREE_CODE (node) == FUNCTION_DECL
5364 	        && DECL_DECLARED_INLINE_P (node))
5365 	{
5366 	  warning (OPT_Wattributes, "inline function %q+D declared as "
5367 		  " dllimport: attribute ignored", node);
5368 	  *no_add_attrs = true;
5369 	}
5370       /* Like MS, treat definition of dllimported variables and
5371 	 non-inlined functions on declaration as syntax errors. */
5372      else if (TREE_CODE (node) == FUNCTION_DECL && DECL_INITIAL (node))
5373 	{
5374 	  error ("function %q+D definition is marked dllimport", node);
5375 	  *no_add_attrs = true;
5376 	}
5377 
5378      else if (TREE_CODE (node) == VAR_DECL)
5379 	{
5380 	  if (DECL_INITIAL (node))
5381 	    {
5382 	      error ("variable %q+D definition is marked dllimport",
5383 		     node);
5384 	      *no_add_attrs = true;
5385 	    }
5386 
5387 	  /* `extern' needn't be specified with dllimport.
5388 	     Specify `extern' now and hope for the best.  Sigh.  */
5389 	  DECL_EXTERNAL (node) = 1;
5390 	  /* Also, implicitly give dllimport'd variables declared within
5391 	     a function global scope, unless declared static.  */
5392 	  if (current_function_decl != NULL_TREE && !TREE_STATIC (node))
5393 	    TREE_PUBLIC (node) = 1;
5394 	}
5395 
5396       if (*no_add_attrs == false)
5397         DECL_DLLIMPORT_P (node) = 1;
5398     }
5399   else if (TREE_CODE (node) == FUNCTION_DECL
5400 	   && DECL_DECLARED_INLINE_P (node))
5401     /* An exported function, even if inline, must be emitted.  */
5402     DECL_EXTERNAL (node) = 0;
5403 
5404   /*  Report error if symbol is not accessible at global scope.  */
5405   if (!TREE_PUBLIC (node)
5406       && (TREE_CODE (node) == VAR_DECL
5407 	  || TREE_CODE (node) == FUNCTION_DECL))
5408     {
5409       error ("external linkage required for symbol %q+D because of "
5410 	     "%qE attribute", node, name);
5411       *no_add_attrs = true;
5412     }
5413 
5414   /* A dllexport'd entity must have default visibility so that other
5415      program units (shared libraries or the main executable) can see
5416      it.  A dllimport'd entity must have default visibility so that
5417      the linker knows that undefined references within this program
5418      unit can be resolved by the dynamic linker.  */
5419   if (!*no_add_attrs)
5420     {
5421       if (DECL_VISIBILITY_SPECIFIED (node)
5422 	  && DECL_VISIBILITY (node) != VISIBILITY_DEFAULT)
5423 	error ("%qE implies default visibility, but %qD has already "
5424 	       "been declared with a different visibility",
5425 	       name, node);
5426       DECL_VISIBILITY (node) = VISIBILITY_DEFAULT;
5427       DECL_VISIBILITY_SPECIFIED (node) = 1;
5428     }
5429 
5430   return NULL_TREE;
5431 }
5432 
5433 #endif /* TARGET_DLLIMPORT_DECL_ATTRIBUTES  */
5434 
5435 /* Set the type qualifiers for TYPE to TYPE_QUALS, which is a bitmask
5436    of the various TYPE_QUAL values.  */
5437 
5438 static void
5439 set_type_quals (tree type, int type_quals)
5440 {
5441   TYPE_READONLY (type) = (type_quals & TYPE_QUAL_CONST) != 0;
5442   TYPE_VOLATILE (type) = (type_quals & TYPE_QUAL_VOLATILE) != 0;
5443   TYPE_RESTRICT (type) = (type_quals & TYPE_QUAL_RESTRICT) != 0;
5444   TYPE_ADDR_SPACE (type) = DECODE_QUAL_ADDR_SPACE (type_quals);
5445 }
5446 
5447 /* Returns true iff CAND is equivalent to BASE with TYPE_QUALS.  */
5448 
5449 bool
5450 check_qualified_type (const_tree cand, const_tree base, int type_quals)
5451 {
5452   return (TYPE_QUALS (cand) == type_quals
5453 	  && TYPE_NAME (cand) == TYPE_NAME (base)
5454 	  /* Apparently this is needed for Objective-C.  */
5455 	  && TYPE_CONTEXT (cand) == TYPE_CONTEXT (base)
5456 	  && attribute_list_equal (TYPE_ATTRIBUTES (cand),
5457 				   TYPE_ATTRIBUTES (base)));
5458 }
5459 
5460 /* Return a version of the TYPE, qualified as indicated by the
5461    TYPE_QUALS, if one exists.  If no qualified version exists yet,
5462    return NULL_TREE.  */
5463 
5464 tree
5465 get_qualified_type (tree type, int type_quals)
5466 {
5467   tree t;
5468 
5469   if (TYPE_QUALS (type) == type_quals)
5470     return type;
5471 
5472   /* Search the chain of variants to see if there is already one there just
5473      like the one we need to have.  If so, use that existing one.  We must
5474      preserve the TYPE_NAME, since there is code that depends on this.  */
5475   for (t = TYPE_MAIN_VARIANT (type); t; t = TYPE_NEXT_VARIANT (t))
5476     if (check_qualified_type (t, type, type_quals))
5477       return t;
5478 
5479   return NULL_TREE;
5480 }
5481 
5482 /* Like get_qualified_type, but creates the type if it does not
5483    exist.  This function never returns NULL_TREE.  */
5484 
5485 tree
5486 build_qualified_type (tree type, int type_quals)
5487 {
5488   tree t;
5489 
5490   /* See if we already have the appropriate qualified variant.  */
5491   t = get_qualified_type (type, type_quals);
5492 
5493   /* If not, build it.  */
5494   if (!t)
5495     {
5496       t = build_variant_type_copy (type);
5497       set_type_quals (t, type_quals);
5498 
5499       if (TYPE_STRUCTURAL_EQUALITY_P (type))
5500 	/* Propagate structural equality. */
5501 	SET_TYPE_STRUCTURAL_EQUALITY (t);
5502       else if (TYPE_CANONICAL (type) != type)
5503 	/* Build the underlying canonical type, since it is different
5504 	   from TYPE. */
5505 	TYPE_CANONICAL (t) = build_qualified_type (TYPE_CANONICAL (type),
5506 						   type_quals);
5507       else
5508 	/* T is its own canonical type. */
5509 	TYPE_CANONICAL (t) = t;
5510 
5511     }
5512 
5513   return t;
5514 }
5515 
5516 /* Create a new distinct copy of TYPE.  The new type is made its own
5517    MAIN_VARIANT. If TYPE requires structural equality checks, the
5518    resulting type requires structural equality checks; otherwise, its
5519    TYPE_CANONICAL points to itself. */
5520 
5521 tree
5522 build_distinct_type_copy (tree type)
5523 {
5524   tree t = copy_node (type);
5525 
5526   TYPE_POINTER_TO (t) = 0;
5527   TYPE_REFERENCE_TO (t) = 0;
5528 
5529   /* Set the canonical type either to a new equivalence class, or
5530      propagate the need for structural equality checks. */
5531   if (TYPE_STRUCTURAL_EQUALITY_P (type))
5532     SET_TYPE_STRUCTURAL_EQUALITY (t);
5533   else
5534     TYPE_CANONICAL (t) = t;
5535 
5536   /* Make it its own variant.  */
5537   TYPE_MAIN_VARIANT (t) = t;
5538   TYPE_NEXT_VARIANT (t) = 0;
5539 
5540   /* Note that it is now possible for TYPE_MIN_VALUE to be a value
5541      whose TREE_TYPE is not t.  This can also happen in the Ada
5542      frontend when using subtypes.  */
5543 
5544   return t;
5545 }
5546 
5547 /* Create a new variant of TYPE, equivalent but distinct.  This is so
5548    the caller can modify it. TYPE_CANONICAL for the return type will
5549    be equivalent to TYPE_CANONICAL of TYPE, indicating that the types
5550    are considered equal by the language itself (or that both types
5551    require structural equality checks). */
5552 
5553 tree
5554 build_variant_type_copy (tree type)
5555 {
5556   tree t, m = TYPE_MAIN_VARIANT (type);
5557 
5558   t = build_distinct_type_copy (type);
5559 
5560   /* Since we're building a variant, assume that it is a non-semantic
5561      variant. This also propagates TYPE_STRUCTURAL_EQUALITY_P. */
5562   TYPE_CANONICAL (t) = TYPE_CANONICAL (type);
5563 
5564   /* Add the new type to the chain of variants of TYPE.  */
5565   TYPE_NEXT_VARIANT (t) = TYPE_NEXT_VARIANT (m);
5566   TYPE_NEXT_VARIANT (m) = t;
5567   TYPE_MAIN_VARIANT (t) = m;
5568 
5569   return t;
5570 }
5571 
5572 /* Return true if the from tree in both tree maps are equal.  */
5573 
5574 int
5575 tree_map_base_eq (const void *va, const void *vb)
5576 {
5577   const struct tree_map_base  *const a = (const struct tree_map_base *) va,
5578     *const b = (const struct tree_map_base *) vb;
5579   return (a->from == b->from);
5580 }
5581 
5582 /* Hash a from tree in a tree_map.  */
5583 
5584 unsigned int
5585 tree_map_base_hash (const void *item)
5586 {
5587   return htab_hash_pointer (((const struct tree_map_base *)item)->from);
5588 }
5589 
5590 /* Return true if this tree map structure is marked for garbage collection
5591    purposes.  We simply return true if the from tree is marked, so that this
5592    structure goes away when the from tree goes away.  */
5593 
5594 int
5595 tree_map_base_marked_p (const void *p)
5596 {
5597   return ggc_marked_p (((const struct tree_map_base *) p)->from);
5598 }
5599 
5600 unsigned int
5601 tree_map_hash (const void *item)
5602 {
5603   return (((const struct tree_map *) item)->hash);
5604 }
5605 
5606 /* Return the initialization priority for DECL.  */
5607 
5608 priority_type
5609 decl_init_priority_lookup (tree decl)
5610 {
5611   struct tree_priority_map *h;
5612   struct tree_map_base in;
5613 
5614   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
5615   in.from = decl;
5616   h = (struct tree_priority_map *) htab_find (init_priority_for_decl, &in);
5617   return h ? h->init : DEFAULT_INIT_PRIORITY;
5618 }
5619 
5620 /* Return the finalization priority for DECL.  */
5621 
5622 priority_type
5623 decl_fini_priority_lookup (tree decl)
5624 {
5625   struct tree_priority_map *h;
5626   struct tree_map_base in;
5627 
5628   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
5629   in.from = decl;
5630   h = (struct tree_priority_map *) htab_find (init_priority_for_decl, &in);
5631   return h ? h->fini : DEFAULT_INIT_PRIORITY;
5632 }
5633 
5634 /* Return the initialization and finalization priority information for
5635    DECL.  If there is no previous priority information, a freshly
5636    allocated structure is returned.  */
5637 
5638 static struct tree_priority_map *
5639 decl_priority_info (tree decl)
5640 {
5641   struct tree_priority_map in;
5642   struct tree_priority_map *h;
5643   void **loc;
5644 
5645   in.base.from = decl;
5646   loc = htab_find_slot (init_priority_for_decl, &in, INSERT);
5647   h = (struct tree_priority_map *) *loc;
5648   if (!h)
5649     {
5650       h = GGC_CNEW (struct tree_priority_map);
5651       *loc = h;
5652       h->base.from = decl;
5653       h->init = DEFAULT_INIT_PRIORITY;
5654       h->fini = DEFAULT_INIT_PRIORITY;
5655     }
5656 
5657   return h;
5658 }
5659 
5660 /* Set the initialization priority for DECL to PRIORITY.  */
5661 
5662 void
5663 decl_init_priority_insert (tree decl, priority_type priority)
5664 {
5665   struct tree_priority_map *h;
5666 
5667   gcc_assert (VAR_OR_FUNCTION_DECL_P (decl));
5668   h = decl_priority_info (decl);
5669   h->init = priority;
5670 }
5671 
5672 /* Set the finalization priority for DECL to PRIORITY.  */
5673 
5674 void
5675 decl_fini_priority_insert (tree decl, priority_type priority)
5676 {
5677   struct tree_priority_map *h;
5678 
5679   gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
5680   h = decl_priority_info (decl);
5681   h->fini = priority;
5682 }
5683 
5684 /* Print out the statistics for the DECL_DEBUG_EXPR hash table.  */
5685 
5686 static void
5687 print_debug_expr_statistics (void)
5688 {
5689   fprintf (stderr, "DECL_DEBUG_EXPR  hash: size %ld, %ld elements, %f collisions\n",
5690 	   (long) htab_size (debug_expr_for_decl),
5691 	   (long) htab_elements (debug_expr_for_decl),
5692 	   htab_collisions (debug_expr_for_decl));
5693 }
5694 
5695 /* Print out the statistics for the DECL_VALUE_EXPR hash table.  */
5696 
5697 static void
5698 print_value_expr_statistics (void)
5699 {
5700   fprintf (stderr, "DECL_VALUE_EXPR  hash: size %ld, %ld elements, %f collisions\n",
5701 	   (long) htab_size (value_expr_for_decl),
5702 	   (long) htab_elements (value_expr_for_decl),
5703 	   htab_collisions (value_expr_for_decl));
5704 }
5705 
5706 /* Lookup a debug expression for FROM, and return it if we find one.  */
5707 
5708 tree
5709 decl_debug_expr_lookup (tree from)
5710 {
5711   struct tree_map *h, in;
5712   in.base.from = from;
5713 
5714   h = (struct tree_map *) htab_find_with_hash (debug_expr_for_decl, &in,
5715 					       htab_hash_pointer (from));
5716   if (h)
5717     return h->to;
5718   return NULL_TREE;
5719 }
5720 
5721 /* Insert a mapping FROM->TO in the debug expression hashtable.  */
5722 
5723 void
5724 decl_debug_expr_insert (tree from, tree to)
5725 {
5726   struct tree_map *h;
5727   void **loc;
5728 
5729   h = GGC_NEW (struct tree_map);
5730   h->hash = htab_hash_pointer (from);
5731   h->base.from = from;
5732   h->to = to;
5733   loc = htab_find_slot_with_hash (debug_expr_for_decl, h, h->hash, INSERT);
5734   *(struct tree_map **) loc = h;
5735 }
5736 
5737 /* Lookup a value expression for FROM, and return it if we find one.  */
5738 
5739 tree
5740 decl_value_expr_lookup (tree from)
5741 {
5742   struct tree_map *h, in;
5743   in.base.from = from;
5744 
5745   h = (struct tree_map *) htab_find_with_hash (value_expr_for_decl, &in,
5746 					       htab_hash_pointer (from));
5747   if (h)
5748     return h->to;
5749   return NULL_TREE;
5750 }
5751 
5752 /* Insert a mapping FROM->TO in the value expression hashtable.  */
5753 
5754 void
5755 decl_value_expr_insert (tree from, tree to)
5756 {
5757   struct tree_map *h;
5758   void **loc;
5759 
5760   h = GGC_NEW (struct tree_map);
5761   h->hash = htab_hash_pointer (from);
5762   h->base.from = from;
5763   h->to = to;
5764   loc = htab_find_slot_with_hash (value_expr_for_decl, h, h->hash, INSERT);
5765   *(struct tree_map **) loc = h;
5766 }
5767 
5768 /* Hashing of types so that we don't make duplicates.
5769    The entry point is `type_hash_canon'.  */
5770 
5771 /* Compute a hash code for a list of types (chain of TREE_LIST nodes
5772    with types in the TREE_VALUE slots), by adding the hash codes
5773    of the individual types.  */
5774 
5775 static unsigned int
5776 type_hash_list (const_tree list, hashval_t hashcode)
5777 {
5778   const_tree tail;
5779 
5780   for (tail = list; tail; tail = TREE_CHAIN (tail))
5781     if (TREE_VALUE (tail) != error_mark_node)
5782       hashcode = iterative_hash_object (TYPE_HASH (TREE_VALUE (tail)),
5783 					hashcode);
5784 
5785   return hashcode;
5786 }
5787 
5788 /* These are the Hashtable callback functions.  */
5789 
5790 /* Returns true iff the types are equivalent.  */
5791 
5792 static int
5793 type_hash_eq (const void *va, const void *vb)
5794 {
5795   const struct type_hash *const a = (const struct type_hash *) va,
5796     *const b = (const struct type_hash *) vb;
5797 
5798   /* First test the things that are the same for all types.  */
5799   if (a->hash != b->hash
5800       || TREE_CODE (a->type) != TREE_CODE (b->type)
5801       || TREE_TYPE (a->type) != TREE_TYPE (b->type)
5802       || !attribute_list_equal (TYPE_ATTRIBUTES (a->type),
5803 				 TYPE_ATTRIBUTES (b->type))
5804       || (TREE_CODE (a->type) != COMPLEX_TYPE
5805           && TYPE_NAME (a->type) != TYPE_NAME (b->type)))
5806     return 0;
5807 
5808   /* Be careful about comparing arrays before and after the element type
5809      has been completed; don't compare TYPE_ALIGN unless both types are
5810      complete.  */
5811   if (COMPLETE_TYPE_P (a->type) && COMPLETE_TYPE_P (b->type)
5812       && (TYPE_ALIGN (a->type) != TYPE_ALIGN (b->type)
5813 	  || TYPE_MODE (a->type) != TYPE_MODE (b->type)))
5814     return 0;
5815 
5816   switch (TREE_CODE (a->type))
5817     {
5818     case VOID_TYPE:
5819     case COMPLEX_TYPE:
5820     case POINTER_TYPE:
5821     case REFERENCE_TYPE:
5822       return 1;
5823 
5824     case VECTOR_TYPE:
5825       return TYPE_VECTOR_SUBPARTS (a->type) == TYPE_VECTOR_SUBPARTS (b->type);
5826 
5827     case ENUMERAL_TYPE:
5828       if (TYPE_VALUES (a->type) != TYPE_VALUES (b->type)
5829 	  && !(TYPE_VALUES (a->type)
5830 	       && TREE_CODE (TYPE_VALUES (a->type)) == TREE_LIST
5831 	       && TYPE_VALUES (b->type)
5832 	       && TREE_CODE (TYPE_VALUES (b->type)) == TREE_LIST
5833 	       && type_list_equal (TYPE_VALUES (a->type),
5834 				   TYPE_VALUES (b->type))))
5835 	return 0;
5836 
5837       /* ... fall through ... */
5838 
5839     case INTEGER_TYPE:
5840     case REAL_TYPE:
5841     case BOOLEAN_TYPE:
5842       return ((TYPE_MAX_VALUE (a->type) == TYPE_MAX_VALUE (b->type)
5843 	       || tree_int_cst_equal (TYPE_MAX_VALUE (a->type),
5844 				      TYPE_MAX_VALUE (b->type)))
5845 	      && (TYPE_MIN_VALUE (a->type) == TYPE_MIN_VALUE (b->type)
5846 		  || tree_int_cst_equal (TYPE_MIN_VALUE (a->type),
5847 					 TYPE_MIN_VALUE (b->type))));
5848 
5849     case FIXED_POINT_TYPE:
5850       return TYPE_SATURATING (a->type) == TYPE_SATURATING (b->type);
5851 
5852     case OFFSET_TYPE:
5853       return TYPE_OFFSET_BASETYPE (a->type) == TYPE_OFFSET_BASETYPE (b->type);
5854 
5855     case METHOD_TYPE:
5856       return (TYPE_METHOD_BASETYPE (a->type) == TYPE_METHOD_BASETYPE (b->type)
5857 	      && (TYPE_ARG_TYPES (a->type) == TYPE_ARG_TYPES (b->type)
5858 		  || (TYPE_ARG_TYPES (a->type)
5859 		      && TREE_CODE (TYPE_ARG_TYPES (a->type)) == TREE_LIST
5860 		      && TYPE_ARG_TYPES (b->type)
5861 		      && TREE_CODE (TYPE_ARG_TYPES (b->type)) == TREE_LIST
5862 		      && type_list_equal (TYPE_ARG_TYPES (a->type),
5863 					  TYPE_ARG_TYPES (b->type)))));
5864 
5865     case ARRAY_TYPE:
5866       return TYPE_DOMAIN (a->type) == TYPE_DOMAIN (b->type);
5867 
5868     case RECORD_TYPE:
5869     case UNION_TYPE:
5870     case QUAL_UNION_TYPE:
5871       return (TYPE_FIELDS (a->type) == TYPE_FIELDS (b->type)
5872 	      || (TYPE_FIELDS (a->type)
5873 		  && TREE_CODE (TYPE_FIELDS (a->type)) == TREE_LIST
5874 		  && TYPE_FIELDS (b->type)
5875 		  && TREE_CODE (TYPE_FIELDS (b->type)) == TREE_LIST
5876 		  && type_list_equal (TYPE_FIELDS (a->type),
5877 				      TYPE_FIELDS (b->type))));
5878 
5879     case FUNCTION_TYPE:
5880       if (TYPE_ARG_TYPES (a->type) == TYPE_ARG_TYPES (b->type)
5881 	  || (TYPE_ARG_TYPES (a->type)
5882 	      && TREE_CODE (TYPE_ARG_TYPES (a->type)) == TREE_LIST
5883 	      && TYPE_ARG_TYPES (b->type)
5884 	      && TREE_CODE (TYPE_ARG_TYPES (b->type)) == TREE_LIST
5885 	      && type_list_equal (TYPE_ARG_TYPES (a->type),
5886 				  TYPE_ARG_TYPES (b->type))))
5887 	break;
5888       return 0;
5889 
5890     default:
5891       return 0;
5892     }
5893 
5894   if (lang_hooks.types.type_hash_eq != NULL)
5895     return lang_hooks.types.type_hash_eq (a->type, b->type);
5896 
5897   return 1;
5898 }
5899 
5900 /* Return the cached hash value.  */
5901 
5902 static hashval_t
5903 type_hash_hash (const void *item)
5904 {
5905   return ((const struct type_hash *) item)->hash;
5906 }
5907 
5908 /* Look in the type hash table for a type isomorphic to TYPE.
5909    If one is found, return it.  Otherwise return 0.  */
5910 
5911 tree
5912 type_hash_lookup (hashval_t hashcode, tree type)
5913 {
5914   struct type_hash *h, in;
5915 
5916   /* The TYPE_ALIGN field of a type is set by layout_type(), so we
5917      must call that routine before comparing TYPE_ALIGNs.  */
5918   layout_type (type);
5919 
5920   in.hash = hashcode;
5921   in.type = type;
5922 
5923   h = (struct type_hash *) htab_find_with_hash (type_hash_table, &in,
5924 						hashcode);
5925   if (h)
5926     return h->type;
5927   return NULL_TREE;
5928 }
5929 
5930 /* Add an entry to the type-hash-table
5931    for a type TYPE whose hash code is HASHCODE.  */
5932 
5933 void
5934 type_hash_add (hashval_t hashcode, tree type)
5935 {
5936   struct type_hash *h;
5937   void **loc;
5938 
5939   h = GGC_NEW (struct type_hash);
5940   h->hash = hashcode;
5941   h->type = type;
5942   loc = htab_find_slot_with_hash (type_hash_table, h, hashcode, INSERT);
5943   *loc = (void *)h;
5944 }
5945 
5946 /* Given TYPE, and HASHCODE its hash code, return the canonical
5947    object for an identical type if one already exists.
5948    Otherwise, return TYPE, and record it as the canonical object.
5949 
5950    To use this function, first create a type of the sort you want.
5951    Then compute its hash code from the fields of the type that
5952    make it different from other similar types.
5953    Then call this function and use the value.  */
5954 
5955 tree
5956 type_hash_canon (unsigned int hashcode, tree type)
5957 {
5958   tree t1;
5959 
5960   /* The hash table only contains main variants, so ensure that's what we're
5961      being passed.  */
5962   gcc_assert (TYPE_MAIN_VARIANT (type) == type);
5963 
5964   if (!lang_hooks.types.hash_types)
5965     return type;
5966 
5967   /* See if the type is in the hash table already.  If so, return it.
5968      Otherwise, add the type.  */
5969   t1 = type_hash_lookup (hashcode, type);
5970   if (t1 != 0)
5971     {
5972 #ifdef GATHER_STATISTICS
5973       tree_node_counts[(int) t_kind]--;
5974       tree_node_sizes[(int) t_kind] -= sizeof (struct tree_type);
5975 #endif
5976       return t1;
5977     }
5978   else
5979     {
5980       type_hash_add (hashcode, type);
5981       return type;
5982     }
5983 }
5984 
5985 /* See if the data pointed to by the type hash table is marked.  We consider
5986    it marked if the type is marked or if a debug type number or symbol
5987    table entry has been made for the type.  This reduces the amount of
5988    debugging output and eliminates that dependency of the debug output on
5989    the number of garbage collections.  */
5990 
5991 static int
5992 type_hash_marked_p (const void *p)
5993 {
5994   const_tree const type = ((const struct type_hash *) p)->type;
5995 
5996   return ggc_marked_p (type) || TYPE_SYMTAB_POINTER (type);
5997 }
5998 
5999 static void
6000 print_type_hash_statistics (void)
6001 {
6002   fprintf (stderr, "Type hash: size %ld, %ld elements, %f collisions\n",
6003 	   (long) htab_size (type_hash_table),
6004 	   (long) htab_elements (type_hash_table),
6005 	   htab_collisions (type_hash_table));
6006 }
6007 
6008 /* Compute a hash code for a list of attributes (chain of TREE_LIST nodes
6009    with names in the TREE_PURPOSE slots and args in the TREE_VALUE slots),
6010    by adding the hash codes of the individual attributes.  */
6011 
6012 static unsigned int
6013 attribute_hash_list (const_tree list, hashval_t hashcode)
6014 {
6015   const_tree tail;
6016 
6017   for (tail = list; tail; tail = TREE_CHAIN (tail))
6018     /* ??? Do we want to add in TREE_VALUE too? */
6019     hashcode = iterative_hash_object
6020       (IDENTIFIER_HASH_VALUE (TREE_PURPOSE (tail)), hashcode);
6021   return hashcode;
6022 }
6023 
6024 /* Given two lists of attributes, return true if list l2 is
6025    equivalent to l1.  */
6026 
6027 int
6028 attribute_list_equal (const_tree l1, const_tree l2)
6029 {
6030   return attribute_list_contained (l1, l2)
6031 	 && attribute_list_contained (l2, l1);
6032 }
6033 
6034 /* Given two lists of attributes, return true if list L2 is
6035    completely contained within L1.  */
6036 /* ??? This would be faster if attribute names were stored in a canonicalized
6037    form.  Otherwise, if L1 uses `foo' and L2 uses `__foo__', the long method
6038    must be used to show these elements are equivalent (which they are).  */
6039 /* ??? It's not clear that attributes with arguments will always be handled
6040    correctly.  */
6041 
6042 int
6043 attribute_list_contained (const_tree l1, const_tree l2)
6044 {
6045   const_tree t1, t2;
6046 
6047   /* First check the obvious, maybe the lists are identical.  */
6048   if (l1 == l2)
6049     return 1;
6050 
6051   /* Maybe the lists are similar.  */
6052   for (t1 = l1, t2 = l2;
6053        t1 != 0 && t2 != 0
6054         && TREE_PURPOSE (t1) == TREE_PURPOSE (t2)
6055         && TREE_VALUE (t1) == TREE_VALUE (t2);
6056        t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2));
6057 
6058   /* Maybe the lists are equal.  */
6059   if (t1 == 0 && t2 == 0)
6060     return 1;
6061 
6062   for (; t2 != 0; t2 = TREE_CHAIN (t2))
6063     {
6064       const_tree attr;
6065       /* This CONST_CAST is okay because lookup_attribute does not
6066 	 modify its argument and the return value is assigned to a
6067 	 const_tree.  */
6068       for (attr = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)),
6069 				    CONST_CAST_TREE(l1));
6070 	   attr != NULL_TREE;
6071 	   attr = lookup_attribute (IDENTIFIER_POINTER (TREE_PURPOSE (t2)),
6072 				    TREE_CHAIN (attr)))
6073 	{
6074 	  if (TREE_VALUE (t2) != NULL
6075 	      && TREE_CODE (TREE_VALUE (t2)) == TREE_LIST
6076 	      && TREE_VALUE (attr) != NULL
6077 	      && TREE_CODE (TREE_VALUE (attr)) == TREE_LIST)
6078 	    {
6079 	      if (simple_cst_list_equal (TREE_VALUE (t2),
6080 					 TREE_VALUE (attr)) == 1)
6081 		break;
6082 	    }
6083 	  else if (simple_cst_equal (TREE_VALUE (t2), TREE_VALUE (attr)) == 1)
6084 	    break;
6085 	}
6086 
6087       if (attr == 0)
6088 	return 0;
6089     }
6090 
6091   return 1;
6092 }
6093 
6094 /* Given two lists of types
6095    (chains of TREE_LIST nodes with types in the TREE_VALUE slots)
6096    return 1 if the lists contain the same types in the same order.
6097    Also, the TREE_PURPOSEs must match.  */
6098 
6099 int
6100 type_list_equal (const_tree l1, const_tree l2)
6101 {
6102   const_tree t1, t2;
6103 
6104   for (t1 = l1, t2 = l2; t1 && t2; t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
6105     if (TREE_VALUE (t1) != TREE_VALUE (t2)
6106 	|| (TREE_PURPOSE (t1) != TREE_PURPOSE (t2)
6107 	    && ! (1 == simple_cst_equal (TREE_PURPOSE (t1), TREE_PURPOSE (t2))
6108 		  && (TREE_TYPE (TREE_PURPOSE (t1))
6109 		      == TREE_TYPE (TREE_PURPOSE (t2))))))
6110       return 0;
6111 
6112   return t1 == t2;
6113 }
6114 
6115 /* Returns the number of arguments to the FUNCTION_TYPE or METHOD_TYPE
6116    given by TYPE.  If the argument list accepts variable arguments,
6117    then this function counts only the ordinary arguments.  */
6118 
6119 int
6120 type_num_arguments (const_tree type)
6121 {
6122   int i = 0;
6123   tree t;
6124 
6125   for (t = TYPE_ARG_TYPES (type); t; t = TREE_CHAIN (t))
6126     /* If the function does not take a variable number of arguments,
6127        the last element in the list will have type `void'.  */
6128     if (VOID_TYPE_P (TREE_VALUE (t)))
6129       break;
6130     else
6131       ++i;
6132 
6133   return i;
6134 }
6135 
6136 /* Nonzero if integer constants T1 and T2
6137    represent the same constant value.  */
6138 
6139 int
6140 tree_int_cst_equal (const_tree t1, const_tree t2)
6141 {
6142   if (t1 == t2)
6143     return 1;
6144 
6145   if (t1 == 0 || t2 == 0)
6146     return 0;
6147 
6148   if (TREE_CODE (t1) == INTEGER_CST
6149       && TREE_CODE (t2) == INTEGER_CST
6150       && TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
6151       && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2))
6152     return 1;
6153 
6154   return 0;
6155 }
6156 
6157 /* Nonzero if integer constants T1 and T2 represent values that satisfy <.
6158    The precise way of comparison depends on their data type.  */
6159 
6160 int
6161 tree_int_cst_lt (const_tree t1, const_tree t2)
6162 {
6163   if (t1 == t2)
6164     return 0;
6165 
6166   if (TYPE_UNSIGNED (TREE_TYPE (t1)) != TYPE_UNSIGNED (TREE_TYPE (t2)))
6167     {
6168       int t1_sgn = tree_int_cst_sgn (t1);
6169       int t2_sgn = tree_int_cst_sgn (t2);
6170 
6171       if (t1_sgn < t2_sgn)
6172 	return 1;
6173       else if (t1_sgn > t2_sgn)
6174 	return 0;
6175       /* Otherwise, both are non-negative, so we compare them as
6176 	 unsigned just in case one of them would overflow a signed
6177 	 type.  */
6178     }
6179   else if (!TYPE_UNSIGNED (TREE_TYPE (t1)))
6180     return INT_CST_LT (t1, t2);
6181 
6182   return INT_CST_LT_UNSIGNED (t1, t2);
6183 }
6184 
6185 /* Returns -1 if T1 < T2, 0 if T1 == T2, and 1 if T1 > T2.  */
6186 
6187 int
6188 tree_int_cst_compare (const_tree t1, const_tree t2)
6189 {
6190   if (tree_int_cst_lt (t1, t2))
6191     return -1;
6192   else if (tree_int_cst_lt (t2, t1))
6193     return 1;
6194   else
6195     return 0;
6196 }
6197 
6198 /* Return 1 if T is an INTEGER_CST that can be manipulated efficiently on
6199    the host.  If POS is zero, the value can be represented in a single
6200    HOST_WIDE_INT.  If POS is nonzero, the value must be non-negative and can
6201    be represented in a single unsigned HOST_WIDE_INT.  */
6202 
6203 int
6204 host_integerp (const_tree t, int pos)
6205 {
6206   if (t == NULL_TREE)
6207     return 0;
6208 
6209   return (TREE_CODE (t) == INTEGER_CST
6210 	  && ((TREE_INT_CST_HIGH (t) == 0
6211 	       && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) >= 0)
6212 	      || (! pos && TREE_INT_CST_HIGH (t) == -1
6213 		  && (HOST_WIDE_INT) TREE_INT_CST_LOW (t) < 0
6214 		  && (!TYPE_UNSIGNED (TREE_TYPE (t))
6215 		      || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
6216 			  && TYPE_IS_SIZETYPE (TREE_TYPE (t)))))
6217 	      || (pos && TREE_INT_CST_HIGH (t) == 0)));
6218 }
6219 
6220 /* Return the HOST_WIDE_INT least significant bits of T if it is an
6221    INTEGER_CST and there is no overflow.  POS is nonzero if the result must
6222    be non-negative.  We must be able to satisfy the above conditions.  */
6223 
6224 HOST_WIDE_INT
6225 tree_low_cst (const_tree t, int pos)
6226 {
6227   gcc_assert (host_integerp (t, pos));
6228   return TREE_INT_CST_LOW (t);
6229 }
6230 
6231 /* Return the most significant bit of the integer constant T.  */
6232 
6233 int
6234 tree_int_cst_msb (const_tree t)
6235 {
6236   int prec;
6237   HOST_WIDE_INT h;
6238   unsigned HOST_WIDE_INT l;
6239 
6240   /* Note that using TYPE_PRECISION here is wrong.  We care about the
6241      actual bits, not the (arbitrary) range of the type.  */
6242   prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (t))) - 1;
6243   rshift_double (TREE_INT_CST_LOW (t), TREE_INT_CST_HIGH (t), prec,
6244 		 2 * HOST_BITS_PER_WIDE_INT, &l, &h, 0);
6245   return (l & 1) == 1;
6246 }
6247 
6248 /* Return an indication of the sign of the integer constant T.
6249    The return value is -1 if T < 0, 0 if T == 0, and 1 if T > 0.
6250    Note that -1 will never be returned if T's type is unsigned.  */
6251 
6252 int
6253 tree_int_cst_sgn (const_tree t)
6254 {
6255   if (TREE_INT_CST_LOW (t) == 0 && TREE_INT_CST_HIGH (t) == 0)
6256     return 0;
6257   else if (TYPE_UNSIGNED (TREE_TYPE (t)))
6258     return 1;
6259   else if (TREE_INT_CST_HIGH (t) < 0)
6260     return -1;
6261   else
6262     return 1;
6263 }
6264 
6265 /* Return the minimum number of bits needed to represent VALUE in a
6266    signed or unsigned type, UNSIGNEDP says which.  */
6267 
6268 unsigned int
6269 tree_int_cst_min_precision (tree value, bool unsignedp)
6270 {
6271   int log;
6272 
6273   /* If the value is negative, compute its negative minus 1.  The latter
6274      adjustment is because the absolute value of the largest negative value
6275      is one larger than the largest positive value.  This is equivalent to
6276      a bit-wise negation, so use that operation instead.  */
6277 
6278   if (tree_int_cst_sgn (value) < 0)
6279     value = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (value), value);
6280 
6281   /* Return the number of bits needed, taking into account the fact
6282      that we need one more bit for a signed than unsigned type.  */
6283 
6284   if (integer_zerop (value))
6285     log = 0;
6286   else
6287     log = tree_floor_log2 (value);
6288 
6289   return log + 1 + !unsignedp;
6290 }
6291 
6292 /* Compare two constructor-element-type constants.  Return 1 if the lists
6293    are known to be equal; otherwise return 0.  */
6294 
6295 int
6296 simple_cst_list_equal (const_tree l1, const_tree l2)
6297 {
6298   while (l1 != NULL_TREE && l2 != NULL_TREE)
6299     {
6300       if (simple_cst_equal (TREE_VALUE (l1), TREE_VALUE (l2)) != 1)
6301 	return 0;
6302 
6303       l1 = TREE_CHAIN (l1);
6304       l2 = TREE_CHAIN (l2);
6305     }
6306 
6307   return l1 == l2;
6308 }
6309 
6310 /* Return truthvalue of whether T1 is the same tree structure as T2.
6311    Return 1 if they are the same.
6312    Return 0 if they are understandably different.
6313    Return -1 if either contains tree structure not understood by
6314    this function.  */
6315 
6316 int
6317 simple_cst_equal (const_tree t1, const_tree t2)
6318 {
6319   enum tree_code code1, code2;
6320   int cmp;
6321   int i;
6322 
6323   if (t1 == t2)
6324     return 1;
6325   if (t1 == 0 || t2 == 0)
6326     return 0;
6327 
6328   code1 = TREE_CODE (t1);
6329   code2 = TREE_CODE (t2);
6330 
6331   if (CONVERT_EXPR_CODE_P (code1) || code1 == NON_LVALUE_EXPR)
6332     {
6333       if (CONVERT_EXPR_CODE_P (code2)
6334 	  || code2 == NON_LVALUE_EXPR)
6335 	return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6336       else
6337 	return simple_cst_equal (TREE_OPERAND (t1, 0), t2);
6338     }
6339 
6340   else if (CONVERT_EXPR_CODE_P (code2)
6341 	   || code2 == NON_LVALUE_EXPR)
6342     return simple_cst_equal (t1, TREE_OPERAND (t2, 0));
6343 
6344   if (code1 != code2)
6345     return 0;
6346 
6347   switch (code1)
6348     {
6349     case INTEGER_CST:
6350       return (TREE_INT_CST_LOW (t1) == TREE_INT_CST_LOW (t2)
6351 	      && TREE_INT_CST_HIGH (t1) == TREE_INT_CST_HIGH (t2));
6352 
6353     case REAL_CST:
6354       return REAL_VALUES_IDENTICAL (TREE_REAL_CST (t1), TREE_REAL_CST (t2));
6355 
6356     case FIXED_CST:
6357       return FIXED_VALUES_IDENTICAL (TREE_FIXED_CST (t1), TREE_FIXED_CST (t2));
6358 
6359     case STRING_CST:
6360       return (TREE_STRING_LENGTH (t1) == TREE_STRING_LENGTH (t2)
6361 	      && ! memcmp (TREE_STRING_POINTER (t1), TREE_STRING_POINTER (t2),
6362 			 TREE_STRING_LENGTH (t1)));
6363 
6364     case CONSTRUCTOR:
6365       {
6366 	unsigned HOST_WIDE_INT idx;
6367 	VEC(constructor_elt, gc) *v1 = CONSTRUCTOR_ELTS (t1);
6368 	VEC(constructor_elt, gc) *v2 = CONSTRUCTOR_ELTS (t2);
6369 
6370 	if (VEC_length (constructor_elt, v1) != VEC_length (constructor_elt, v2))
6371 	  return false;
6372 
6373         for (idx = 0; idx < VEC_length (constructor_elt, v1); ++idx)
6374 	  /* ??? Should we handle also fields here? */
6375 	  if (!simple_cst_equal (VEC_index (constructor_elt, v1, idx)->value,
6376 				 VEC_index (constructor_elt, v2, idx)->value))
6377 	    return false;
6378 	return true;
6379       }
6380 
6381     case SAVE_EXPR:
6382       return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6383 
6384     case CALL_EXPR:
6385       cmp = simple_cst_equal (CALL_EXPR_FN (t1), CALL_EXPR_FN (t2));
6386       if (cmp <= 0)
6387 	return cmp;
6388       if (call_expr_nargs (t1) != call_expr_nargs (t2))
6389 	return 0;
6390       {
6391 	const_tree arg1, arg2;
6392 	const_call_expr_arg_iterator iter1, iter2;
6393 	for (arg1 = first_const_call_expr_arg (t1, &iter1),
6394 	       arg2 = first_const_call_expr_arg (t2, &iter2);
6395 	     arg1 && arg2;
6396 	     arg1 = next_const_call_expr_arg (&iter1),
6397 	       arg2 = next_const_call_expr_arg (&iter2))
6398 	  {
6399 	    cmp = simple_cst_equal (arg1, arg2);
6400 	    if (cmp <= 0)
6401 	      return cmp;
6402 	  }
6403 	return arg1 == arg2;
6404       }
6405 
6406     case TARGET_EXPR:
6407       /* Special case: if either target is an unallocated VAR_DECL,
6408 	 it means that it's going to be unified with whatever the
6409 	 TARGET_EXPR is really supposed to initialize, so treat it
6410 	 as being equivalent to anything.  */
6411       if ((TREE_CODE (TREE_OPERAND (t1, 0)) == VAR_DECL
6412 	   && DECL_NAME (TREE_OPERAND (t1, 0)) == NULL_TREE
6413 	   && !DECL_RTL_SET_P (TREE_OPERAND (t1, 0)))
6414 	  || (TREE_CODE (TREE_OPERAND (t2, 0)) == VAR_DECL
6415 	      && DECL_NAME (TREE_OPERAND (t2, 0)) == NULL_TREE
6416 	      && !DECL_RTL_SET_P (TREE_OPERAND (t2, 0))))
6417 	cmp = 1;
6418       else
6419 	cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6420 
6421       if (cmp <= 0)
6422 	return cmp;
6423 
6424       return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t2, 1));
6425 
6426     case WITH_CLEANUP_EXPR:
6427       cmp = simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6428       if (cmp <= 0)
6429 	return cmp;
6430 
6431       return simple_cst_equal (TREE_OPERAND (t1, 1), TREE_OPERAND (t1, 1));
6432 
6433     case COMPONENT_REF:
6434       if (TREE_OPERAND (t1, 1) == TREE_OPERAND (t2, 1))
6435 	return simple_cst_equal (TREE_OPERAND (t1, 0), TREE_OPERAND (t2, 0));
6436 
6437       return 0;
6438 
6439     case VAR_DECL:
6440     case PARM_DECL:
6441     case CONST_DECL:
6442     case FUNCTION_DECL:
6443       return 0;
6444 
6445     default:
6446       break;
6447     }
6448 
6449   /* This general rule works for most tree codes.  All exceptions should be
6450      handled above.  If this is a language-specific tree code, we can't
6451      trust what might be in the operand, so say we don't know
6452      the situation.  */
6453   if ((int) code1 >= (int) LAST_AND_UNUSED_TREE_CODE)
6454     return -1;
6455 
6456   switch (TREE_CODE_CLASS (code1))
6457     {
6458     case tcc_unary:
6459     case tcc_binary:
6460     case tcc_comparison:
6461     case tcc_expression:
6462     case tcc_reference:
6463     case tcc_statement:
6464       cmp = 1;
6465       for (i = 0; i < TREE_CODE_LENGTH (code1); i++)
6466 	{
6467 	  cmp = simple_cst_equal (TREE_OPERAND (t1, i), TREE_OPERAND (t2, i));
6468 	  if (cmp <= 0)
6469 	    return cmp;
6470 	}
6471 
6472       return cmp;
6473 
6474     default:
6475       return -1;
6476     }
6477 }
6478 
6479 /* Compare the value of T, an INTEGER_CST, with U, an unsigned integer value.
6480    Return -1, 0, or 1 if the value of T is less than, equal to, or greater
6481    than U, respectively.  */
6482 
6483 int
6484 compare_tree_int (const_tree t, unsigned HOST_WIDE_INT u)
6485 {
6486   if (tree_int_cst_sgn (t) < 0)
6487     return -1;
6488   else if (TREE_INT_CST_HIGH (t) != 0)
6489     return 1;
6490   else if (TREE_INT_CST_LOW (t) == u)
6491     return 0;
6492   else if (TREE_INT_CST_LOW (t) < u)
6493     return -1;
6494   else
6495     return 1;
6496 }
6497 
6498 /* Return true if CODE represents an associative tree code.  Otherwise
6499    return false.  */
6500 bool
6501 associative_tree_code (enum tree_code code)
6502 {
6503   switch (code)
6504     {
6505     case BIT_IOR_EXPR:
6506     case BIT_AND_EXPR:
6507     case BIT_XOR_EXPR:
6508     case PLUS_EXPR:
6509     case MULT_EXPR:
6510     case MIN_EXPR:
6511     case MAX_EXPR:
6512       return true;
6513 
6514     default:
6515       break;
6516     }
6517   return false;
6518 }
6519 
6520 /* Return true if CODE represents a commutative tree code.  Otherwise
6521    return false.  */
6522 bool
6523 commutative_tree_code (enum tree_code code)
6524 {
6525   switch (code)
6526     {
6527     case PLUS_EXPR:
6528     case MULT_EXPR:
6529     case MIN_EXPR:
6530     case MAX_EXPR:
6531     case BIT_IOR_EXPR:
6532     case BIT_XOR_EXPR:
6533     case BIT_AND_EXPR:
6534     case NE_EXPR:
6535     case EQ_EXPR:
6536     case UNORDERED_EXPR:
6537     case ORDERED_EXPR:
6538     case UNEQ_EXPR:
6539     case LTGT_EXPR:
6540     case TRUTH_AND_EXPR:
6541     case TRUTH_XOR_EXPR:
6542     case TRUTH_OR_EXPR:
6543       return true;
6544 
6545     default:
6546       break;
6547     }
6548   return false;
6549 }
6550 
6551 /* Generate a hash value for an expression.  This can be used iteratively
6552    by passing a previous result as the VAL argument.
6553 
6554    This function is intended to produce the same hash for expressions which
6555    would compare equal using operand_equal_p.  */
6556 
6557 hashval_t
6558 iterative_hash_expr (const_tree t, hashval_t val)
6559 {
6560   int i;
6561   enum tree_code code;
6562   char tclass;
6563 
6564   if (t == NULL_TREE)
6565     return iterative_hash_hashval_t (0, val);
6566 
6567   code = TREE_CODE (t);
6568 
6569   switch (code)
6570     {
6571     /* Alas, constants aren't shared, so we can't rely on pointer
6572        identity.  */
6573     case INTEGER_CST:
6574       val = iterative_hash_host_wide_int (TREE_INT_CST_LOW (t), val);
6575       return iterative_hash_host_wide_int (TREE_INT_CST_HIGH (t), val);
6576     case REAL_CST:
6577       {
6578 	unsigned int val2 = real_hash (TREE_REAL_CST_PTR (t));
6579 
6580 	return iterative_hash_hashval_t (val2, val);
6581       }
6582     case FIXED_CST:
6583       {
6584 	unsigned int val2 = fixed_hash (TREE_FIXED_CST_PTR (t));
6585 
6586 	return iterative_hash_hashval_t (val2, val);
6587       }
6588     case STRING_CST:
6589       return iterative_hash (TREE_STRING_POINTER (t),
6590 			     TREE_STRING_LENGTH (t), val);
6591     case COMPLEX_CST:
6592       val = iterative_hash_expr (TREE_REALPART (t), val);
6593       return iterative_hash_expr (TREE_IMAGPART (t), val);
6594     case VECTOR_CST:
6595       return iterative_hash_expr (TREE_VECTOR_CST_ELTS (t), val);
6596 
6597     case SSA_NAME:
6598       /* we can just compare by pointer.  */
6599       return iterative_hash_host_wide_int (SSA_NAME_VERSION (t), val);
6600 
6601     case TREE_LIST:
6602       /* A list of expressions, for a CALL_EXPR or as the elements of a
6603 	 VECTOR_CST.  */
6604       for (; t; t = TREE_CHAIN (t))
6605 	val = iterative_hash_expr (TREE_VALUE (t), val);
6606       return val;
6607     case CONSTRUCTOR:
6608       {
6609 	unsigned HOST_WIDE_INT idx;
6610 	tree field, value;
6611 	FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), idx, field, value)
6612 	  {
6613 	    val = iterative_hash_expr (field, val);
6614 	    val = iterative_hash_expr (value, val);
6615 	  }
6616 	return val;
6617       }
6618     case FUNCTION_DECL:
6619       /* When referring to a built-in FUNCTION_DECL, use the __builtin__ form.
6620 	 Otherwise nodes that compare equal according to operand_equal_p might
6621 	 get different hash codes.  However, don't do this for machine specific
6622 	 or front end builtins, since the function code is overloaded in those
6623 	 cases.  */
6624       if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL
6625 	  && built_in_decls[DECL_FUNCTION_CODE (t)])
6626 	{
6627 	  t = built_in_decls[DECL_FUNCTION_CODE (t)];
6628 	  code = TREE_CODE (t);
6629 	}
6630       /* FALL THROUGH */
6631     default:
6632       tclass = TREE_CODE_CLASS (code);
6633 
6634       if (tclass == tcc_declaration)
6635 	{
6636 	  /* DECL's have a unique ID */
6637 	  val = iterative_hash_host_wide_int (DECL_UID (t), val);
6638 	}
6639       else
6640 	{
6641 	  gcc_assert (IS_EXPR_CODE_CLASS (tclass));
6642 
6643 	  val = iterative_hash_object (code, val);
6644 
6645 	  /* Don't hash the type, that can lead to having nodes which
6646 	     compare equal according to operand_equal_p, but which
6647 	     have different hash codes.  */
6648 	  if (CONVERT_EXPR_CODE_P (code)
6649 	      || code == NON_LVALUE_EXPR)
6650 	    {
6651 	      /* Make sure to include signness in the hash computation.  */
6652 	      val += TYPE_UNSIGNED (TREE_TYPE (t));
6653 	      val = iterative_hash_expr (TREE_OPERAND (t, 0), val);
6654 	    }
6655 
6656 	  else if (commutative_tree_code (code))
6657 	    {
6658 	      /* It's a commutative expression.  We want to hash it the same
6659 		 however it appears.  We do this by first hashing both operands
6660 		 and then rehashing based on the order of their independent
6661 		 hashes.  */
6662 	      hashval_t one = iterative_hash_expr (TREE_OPERAND (t, 0), 0);
6663 	      hashval_t two = iterative_hash_expr (TREE_OPERAND (t, 1), 0);
6664 	      hashval_t t;
6665 
6666 	      if (one > two)
6667 		t = one, one = two, two = t;
6668 
6669 	      val = iterative_hash_hashval_t (one, val);
6670 	      val = iterative_hash_hashval_t (two, val);
6671 	    }
6672 	  else
6673 	    for (i = TREE_OPERAND_LENGTH (t) - 1; i >= 0; --i)
6674 	      val = iterative_hash_expr (TREE_OPERAND (t, i), val);
6675 	}
6676       return val;
6677       break;
6678     }
6679 }
6680 
6681 /* Generate a hash value for a pair of expressions.  This can be used
6682    iteratively by passing a previous result as the VAL argument.
6683 
6684    The same hash value is always returned for a given pair of expressions,
6685    regardless of the order in which they are presented.  This is useful in
6686    hashing the operands of commutative functions.  */
6687 
6688 hashval_t
6689 iterative_hash_exprs_commutative (const_tree t1,
6690                                   const_tree t2, hashval_t val)
6691 {
6692   hashval_t one = iterative_hash_expr (t1, 0);
6693   hashval_t two = iterative_hash_expr (t2, 0);
6694   hashval_t t;
6695 
6696   if (one > two)
6697     t = one, one = two, two = t;
6698   val = iterative_hash_hashval_t (one, val);
6699   val = iterative_hash_hashval_t (two, val);
6700 
6701   return val;
6702 }
6703 
6704 /* Constructors for pointer, array and function types.
6705    (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are
6706    constructed by language-dependent code, not here.)  */
6707 
6708 /* Construct, lay out and return the type of pointers to TO_TYPE with
6709    mode MODE.  If CAN_ALIAS_ALL is TRUE, indicate this type can
6710    reference all of memory. If such a type has already been
6711    constructed, reuse it.  */
6712 
6713 tree
6714 build_pointer_type_for_mode (tree to_type, enum machine_mode mode,
6715 			     bool can_alias_all)
6716 {
6717   tree t;
6718 
6719   if (to_type == error_mark_node)
6720     return error_mark_node;
6721 
6722   /* If the pointed-to type has the may_alias attribute set, force
6723      a TYPE_REF_CAN_ALIAS_ALL pointer to be generated.  */
6724   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (to_type)))
6725     can_alias_all = true;
6726 
6727   /* In some cases, languages will have things that aren't a POINTER_TYPE
6728      (such as a RECORD_TYPE for fat pointers in Ada) as TYPE_POINTER_TO.
6729      In that case, return that type without regard to the rest of our
6730      operands.
6731 
6732      ??? This is a kludge, but consistent with the way this function has
6733      always operated and there doesn't seem to be a good way to avoid this
6734      at the moment.  */
6735   if (TYPE_POINTER_TO (to_type) != 0
6736       && TREE_CODE (TYPE_POINTER_TO (to_type)) != POINTER_TYPE)
6737     return TYPE_POINTER_TO (to_type);
6738 
6739   /* First, if we already have a type for pointers to TO_TYPE and it's
6740      the proper mode, use it.  */
6741   for (t = TYPE_POINTER_TO (to_type); t; t = TYPE_NEXT_PTR_TO (t))
6742     if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
6743       return t;
6744 
6745   t = make_node (POINTER_TYPE);
6746 
6747   TREE_TYPE (t) = to_type;
6748   SET_TYPE_MODE (t, mode);
6749   TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
6750   TYPE_NEXT_PTR_TO (t) = TYPE_POINTER_TO (to_type);
6751   TYPE_POINTER_TO (to_type) = t;
6752 
6753   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
6754     SET_TYPE_STRUCTURAL_EQUALITY (t);
6755   else if (TYPE_CANONICAL (to_type) != to_type)
6756     TYPE_CANONICAL (t)
6757       = build_pointer_type_for_mode (TYPE_CANONICAL (to_type),
6758 				     mode, can_alias_all);
6759 
6760   /* Lay out the type.  This function has many callers that are concerned
6761      with expression-construction, and this simplifies them all.  */
6762   layout_type (t);
6763 
6764   return t;
6765 }
6766 
6767 /* By default build pointers in ptr_mode.  */
6768 
6769 tree
6770 build_pointer_type (tree to_type)
6771 {
6772   addr_space_t as = to_type == error_mark_node? ADDR_SPACE_GENERIC
6773 					      : TYPE_ADDR_SPACE (to_type);
6774   enum machine_mode pointer_mode = targetm.addr_space.pointer_mode (as);
6775   return build_pointer_type_for_mode (to_type, pointer_mode, false);
6776 }
6777 
6778 /* Same as build_pointer_type_for_mode, but for REFERENCE_TYPE.  */
6779 
6780 tree
6781 build_reference_type_for_mode (tree to_type, enum machine_mode mode,
6782 			       bool can_alias_all)
6783 {
6784   tree t;
6785 
6786   if (to_type == error_mark_node)
6787     return error_mark_node;
6788 
6789   /* If the pointed-to type has the may_alias attribute set, force
6790      a TYPE_REF_CAN_ALIAS_ALL pointer to be generated.  */
6791   if (lookup_attribute ("may_alias", TYPE_ATTRIBUTES (to_type)))
6792     can_alias_all = true;
6793 
6794   /* In some cases, languages will have things that aren't a REFERENCE_TYPE
6795      (such as a RECORD_TYPE for fat pointers in Ada) as TYPE_REFERENCE_TO.
6796      In that case, return that type without regard to the rest of our
6797      operands.
6798 
6799      ??? This is a kludge, but consistent with the way this function has
6800      always operated and there doesn't seem to be a good way to avoid this
6801      at the moment.  */
6802   if (TYPE_REFERENCE_TO (to_type) != 0
6803       && TREE_CODE (TYPE_REFERENCE_TO (to_type)) != REFERENCE_TYPE)
6804     return TYPE_REFERENCE_TO (to_type);
6805 
6806   /* First, if we already have a type for pointers to TO_TYPE and it's
6807      the proper mode, use it.  */
6808   for (t = TYPE_REFERENCE_TO (to_type); t; t = TYPE_NEXT_REF_TO (t))
6809     if (TYPE_MODE (t) == mode && TYPE_REF_CAN_ALIAS_ALL (t) == can_alias_all)
6810       return t;
6811 
6812   t = make_node (REFERENCE_TYPE);
6813 
6814   TREE_TYPE (t) = to_type;
6815   SET_TYPE_MODE (t, mode);
6816   TYPE_REF_CAN_ALIAS_ALL (t) = can_alias_all;
6817   TYPE_NEXT_REF_TO (t) = TYPE_REFERENCE_TO (to_type);
6818   TYPE_REFERENCE_TO (to_type) = t;
6819 
6820   if (TYPE_STRUCTURAL_EQUALITY_P (to_type))
6821     SET_TYPE_STRUCTURAL_EQUALITY (t);
6822   else if (TYPE_CANONICAL (to_type) != to_type)
6823     TYPE_CANONICAL (t)
6824       = build_reference_type_for_mode (TYPE_CANONICAL (to_type),
6825 				       mode, can_alias_all);
6826 
6827   layout_type (t);
6828 
6829   return t;
6830 }
6831 
6832 
6833 /* Build the node for the type of references-to-TO_TYPE by default
6834    in ptr_mode.  */
6835 
6836 tree
6837 build_reference_type (tree to_type)
6838 {
6839   addr_space_t as = to_type == error_mark_node? ADDR_SPACE_GENERIC
6840 					      : TYPE_ADDR_SPACE (to_type);
6841   enum machine_mode pointer_mode = targetm.addr_space.pointer_mode (as);
6842   return build_reference_type_for_mode (to_type, pointer_mode, false);
6843 }
6844 
6845 /* Build a type that is compatible with t but has no cv quals anywhere
6846    in its type, thus
6847 
6848    const char *const *const *  ->  char ***.  */
6849 
6850 tree
6851 build_type_no_quals (tree t)
6852 {
6853   switch (TREE_CODE (t))
6854     {
6855     case POINTER_TYPE:
6856       return build_pointer_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
6857 					  TYPE_MODE (t),
6858 					  TYPE_REF_CAN_ALIAS_ALL (t));
6859     case REFERENCE_TYPE:
6860       return
6861 	build_reference_type_for_mode (build_type_no_quals (TREE_TYPE (t)),
6862 				       TYPE_MODE (t),
6863 				       TYPE_REF_CAN_ALIAS_ALL (t));
6864     default:
6865       return TYPE_MAIN_VARIANT (t);
6866     }
6867 }
6868 
6869 /* Create a type of integers to be the TYPE_DOMAIN of an ARRAY_TYPE.
6870    MAXVAL should be the maximum value in the domain
6871    (one less than the length of the array).
6872 
6873    The maximum value that MAXVAL can have is INT_MAX for a HOST_WIDE_INT.
6874    We don't enforce this limit, that is up to caller (e.g. language front end).
6875    The limit exists because the result is a signed type and we don't handle
6876    sizes that use more than one HOST_WIDE_INT.  */
6877 
6878 tree
6879 build_index_type (tree maxval)
6880 {
6881   tree itype = make_node (INTEGER_TYPE);
6882 
6883   TREE_TYPE (itype) = sizetype;
6884   TYPE_PRECISION (itype) = TYPE_PRECISION (sizetype);
6885   TYPE_MIN_VALUE (itype) = size_zero_node;
6886   TYPE_MAX_VALUE (itype) = fold_convert (sizetype, maxval);
6887   SET_TYPE_MODE (itype, TYPE_MODE (sizetype));
6888   TYPE_SIZE (itype) = TYPE_SIZE (sizetype);
6889   TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (sizetype);
6890   TYPE_ALIGN (itype) = TYPE_ALIGN (sizetype);
6891   TYPE_USER_ALIGN (itype) = TYPE_USER_ALIGN (sizetype);
6892 
6893   if (host_integerp (maxval, 1))
6894     return type_hash_canon (tree_low_cst (maxval, 1), itype);
6895   else
6896     {
6897       /* Since we cannot hash this type, we need to compare it using
6898 	 structural equality checks. */
6899       SET_TYPE_STRUCTURAL_EQUALITY (itype);
6900       return itype;
6901     }
6902 }
6903 
6904 /* Builds a signed or unsigned integer type of precision PRECISION.
6905    Used for C bitfields whose precision does not match that of
6906    built-in target types.  */
6907 tree
6908 build_nonstandard_integer_type (unsigned HOST_WIDE_INT precision,
6909 				int unsignedp)
6910 {
6911   tree itype = make_node (INTEGER_TYPE);
6912 
6913   TYPE_PRECISION (itype) = precision;
6914 
6915   if (unsignedp)
6916     fixup_unsigned_type (itype);
6917   else
6918     fixup_signed_type (itype);
6919 
6920   if (host_integerp (TYPE_MAX_VALUE (itype), 1))
6921     return type_hash_canon (tree_low_cst (TYPE_MAX_VALUE (itype), 1), itype);
6922 
6923   return itype;
6924 }
6925 
6926 /* Create a range of some discrete type TYPE (an INTEGER_TYPE,
6927    ENUMERAL_TYPE or BOOLEAN_TYPE), with low bound LOWVAL and
6928    high bound HIGHVAL.  If TYPE is NULL, sizetype is used.  */
6929 
6930 tree
6931 build_range_type (tree type, tree lowval, tree highval)
6932 {
6933   tree itype = make_node (INTEGER_TYPE);
6934 
6935   TREE_TYPE (itype) = type;
6936   if (type == NULL_TREE)
6937     type = sizetype;
6938 
6939   TYPE_MIN_VALUE (itype) = fold_convert (type, lowval);
6940   TYPE_MAX_VALUE (itype) = highval ? fold_convert (type, highval) : NULL;
6941 
6942   TYPE_PRECISION (itype) = TYPE_PRECISION (type);
6943   SET_TYPE_MODE (itype, TYPE_MODE (type));
6944   TYPE_SIZE (itype) = TYPE_SIZE (type);
6945   TYPE_SIZE_UNIT (itype) = TYPE_SIZE_UNIT (type);
6946   TYPE_ALIGN (itype) = TYPE_ALIGN (type);
6947   TYPE_USER_ALIGN (itype) = TYPE_USER_ALIGN (type);
6948 
6949   if (host_integerp (lowval, 0) && highval != 0 && host_integerp (highval, 0))
6950     return type_hash_canon (tree_low_cst (highval, 0)
6951 			    - tree_low_cst (lowval, 0),
6952 			    itype);
6953   else
6954     return itype;
6955 }
6956 
6957 /* Return true if the debug information for TYPE, a subtype, should be emitted
6958    as a subrange type.  If so, set LOWVAL to the low bound and HIGHVAL to the
6959    high bound, respectively.  Sometimes doing so unnecessarily obfuscates the
6960    debug info and doesn't reflect the source code.  */
6961 
6962 bool
6963 subrange_type_for_debug_p (const_tree type, tree *lowval, tree *highval)
6964 {
6965   tree base_type = TREE_TYPE (type), low, high;
6966 
6967   /* Subrange types have a base type which is an integral type.  */
6968   if (!INTEGRAL_TYPE_P (base_type))
6969     return false;
6970 
6971   /* Get the real bounds of the subtype.  */
6972   if (lang_hooks.types.get_subrange_bounds)
6973     lang_hooks.types.get_subrange_bounds (type, &low, &high);
6974   else
6975     {
6976       low = TYPE_MIN_VALUE (type);
6977       high = TYPE_MAX_VALUE (type);
6978     }
6979 
6980   /* If the type and its base type have the same representation and the same
6981      name, then the type is not a subrange but a copy of the base type.  */
6982   if ((TREE_CODE (base_type) == INTEGER_TYPE
6983        || TREE_CODE (base_type) == BOOLEAN_TYPE)
6984       && int_size_in_bytes (type) == int_size_in_bytes (base_type)
6985       && tree_int_cst_equal (low, TYPE_MIN_VALUE (base_type))
6986       && tree_int_cst_equal (high, TYPE_MAX_VALUE (base_type)))
6987     {
6988       tree type_name = TYPE_NAME (type);
6989       tree base_type_name = TYPE_NAME (base_type);
6990 
6991       if (type_name && TREE_CODE (type_name) == TYPE_DECL)
6992 	type_name = DECL_NAME (type_name);
6993 
6994       if (base_type_name && TREE_CODE (base_type_name) == TYPE_DECL)
6995 	base_type_name = DECL_NAME (base_type_name);
6996 
6997       if (type_name == base_type_name)
6998 	return false;
6999     }
7000 
7001   if (lowval)
7002     *lowval = low;
7003   if (highval)
7004     *highval = high;
7005   return true;
7006 }
7007 
7008 /* Just like build_index_type, but takes lowval and highval instead
7009    of just highval (maxval).  */
7010 
7011 tree
7012 build_index_2_type (tree lowval, tree highval)
7013 {
7014   return build_range_type (sizetype, lowval, highval);
7015 }
7016 
7017 /* Construct, lay out and return the type of arrays of elements with ELT_TYPE
7018    and number of elements specified by the range of values of INDEX_TYPE.
7019    If such a type has already been constructed, reuse it.  */
7020 
7021 tree
7022 build_array_type (tree elt_type, tree index_type)
7023 {
7024   tree t;
7025   hashval_t hashcode = 0;
7026 
7027   if (TREE_CODE (elt_type) == FUNCTION_TYPE)
7028     {
7029       error ("arrays of functions are not meaningful");
7030       elt_type = integer_type_node;
7031     }
7032 
7033   t = make_node (ARRAY_TYPE);
7034   TREE_TYPE (t) = elt_type;
7035   TYPE_DOMAIN (t) = index_type;
7036   TYPE_ADDR_SPACE (t) = TYPE_ADDR_SPACE (elt_type);
7037   layout_type (t);
7038 
7039   /* If the element type is incomplete at this point we get marked for
7040      structural equality.  Do not record these types in the canonical
7041      type hashtable.  */
7042   if (TYPE_STRUCTURAL_EQUALITY_P (t))
7043     return t;
7044 
7045   hashcode = iterative_hash_object (TYPE_HASH (elt_type), hashcode);
7046   if (index_type)
7047     hashcode = iterative_hash_object (TYPE_HASH (index_type), hashcode);
7048   t = type_hash_canon (hashcode, t);
7049 
7050   if (TYPE_CANONICAL (t) == t)
7051     {
7052       if (TYPE_STRUCTURAL_EQUALITY_P (elt_type)
7053 	  || (index_type && TYPE_STRUCTURAL_EQUALITY_P (index_type)))
7054 	SET_TYPE_STRUCTURAL_EQUALITY (t);
7055       else if (TYPE_CANONICAL (elt_type) != elt_type
7056 	       || (index_type && TYPE_CANONICAL (index_type) != index_type))
7057 	TYPE_CANONICAL (t)
7058 	  = build_array_type (TYPE_CANONICAL (elt_type),
7059 			      index_type ? TYPE_CANONICAL (index_type) : NULL);
7060     }
7061 
7062   return t;
7063 }
7064 
7065 /* Recursively examines the array elements of TYPE, until a non-array
7066    element type is found.  */
7067 
7068 tree
7069 strip_array_types (tree type)
7070 {
7071   while (TREE_CODE (type) == ARRAY_TYPE)
7072     type = TREE_TYPE (type);
7073 
7074   return type;
7075 }
7076 
7077 /* Computes the canonical argument types from the argument type list
7078    ARGTYPES.
7079 
7080    Upon return, *ANY_STRUCTURAL_P will be true iff either it was true
7081    on entry to this function, or if any of the ARGTYPES are
7082    structural.
7083 
7084    Upon return, *ANY_NONCANONICAL_P will be true iff either it was
7085    true on entry to this function, or if any of the ARGTYPES are
7086    non-canonical.
7087 
7088    Returns a canonical argument list, which may be ARGTYPES when the
7089    canonical argument list is unneeded (i.e., *ANY_STRUCTURAL_P is
7090    true) or would not differ from ARGTYPES.  */
7091 
7092 static tree
7093 maybe_canonicalize_argtypes(tree argtypes,
7094 			    bool *any_structural_p,
7095 			    bool *any_noncanonical_p)
7096 {
7097   tree arg;
7098   bool any_noncanonical_argtypes_p = false;
7099 
7100   for (arg = argtypes; arg && !(*any_structural_p); arg = TREE_CHAIN (arg))
7101     {
7102       if (!TREE_VALUE (arg) || TREE_VALUE (arg) == error_mark_node)
7103 	/* Fail gracefully by stating that the type is structural.  */
7104 	*any_structural_p = true;
7105       else if (TYPE_STRUCTURAL_EQUALITY_P (TREE_VALUE (arg)))
7106 	*any_structural_p = true;
7107       else if (TYPE_CANONICAL (TREE_VALUE (arg)) != TREE_VALUE (arg)
7108 	       || TREE_PURPOSE (arg))
7109 	/* If the argument has a default argument, we consider it
7110 	   non-canonical even though the type itself is canonical.
7111 	   That way, different variants of function and method types
7112 	   with default arguments will all point to the variant with
7113 	   no defaults as their canonical type.  */
7114         any_noncanonical_argtypes_p = true;
7115     }
7116 
7117   if (*any_structural_p)
7118     return argtypes;
7119 
7120   if (any_noncanonical_argtypes_p)
7121     {
7122       /* Build the canonical list of argument types.  */
7123       tree canon_argtypes = NULL_TREE;
7124       bool is_void = false;
7125 
7126       for (arg = argtypes; arg; arg = TREE_CHAIN (arg))
7127         {
7128           if (arg == void_list_node)
7129             is_void = true;
7130           else
7131             canon_argtypes = tree_cons (NULL_TREE,
7132                                         TYPE_CANONICAL (TREE_VALUE (arg)),
7133                                         canon_argtypes);
7134         }
7135 
7136       canon_argtypes = nreverse (canon_argtypes);
7137       if (is_void)
7138         canon_argtypes = chainon (canon_argtypes, void_list_node);
7139 
7140       /* There is a non-canonical type.  */
7141       *any_noncanonical_p = true;
7142       return canon_argtypes;
7143     }
7144 
7145   /* The canonical argument types are the same as ARGTYPES.  */
7146   return argtypes;
7147 }
7148 
7149 /* Construct, lay out and return
7150    the type of functions returning type VALUE_TYPE
7151    given arguments of types ARG_TYPES.
7152    ARG_TYPES is a chain of TREE_LIST nodes whose TREE_VALUEs
7153    are data type nodes for the arguments of the function.
7154    If such a type has already been constructed, reuse it.  */
7155 
7156 tree
7157 build_function_type (tree value_type, tree arg_types)
7158 {
7159   tree t;
7160   hashval_t hashcode = 0;
7161   bool any_structural_p, any_noncanonical_p;
7162   tree canon_argtypes;
7163 
7164   if (TREE_CODE (value_type) == FUNCTION_TYPE)
7165     {
7166       error ("function return type cannot be function");
7167       value_type = integer_type_node;
7168     }
7169 
7170   /* Make a node of the sort we want.  */
7171   t = make_node (FUNCTION_TYPE);
7172   TREE_TYPE (t) = value_type;
7173   TYPE_ARG_TYPES (t) = arg_types;
7174 
7175   /* If we already have such a type, use the old one.  */
7176   hashcode = iterative_hash_object (TYPE_HASH (value_type), hashcode);
7177   hashcode = type_hash_list (arg_types, hashcode);
7178   t = type_hash_canon (hashcode, t);
7179 
7180   /* Set up the canonical type. */
7181   any_structural_p   = TYPE_STRUCTURAL_EQUALITY_P (value_type);
7182   any_noncanonical_p = TYPE_CANONICAL (value_type) != value_type;
7183   canon_argtypes = maybe_canonicalize_argtypes (arg_types,
7184 						&any_structural_p,
7185 						&any_noncanonical_p);
7186   if (any_structural_p)
7187     SET_TYPE_STRUCTURAL_EQUALITY (t);
7188   else if (any_noncanonical_p)
7189     TYPE_CANONICAL (t) = build_function_type (TYPE_CANONICAL (value_type),
7190 					      canon_argtypes);
7191 
7192   if (!COMPLETE_TYPE_P (t))
7193     layout_type (t);
7194   return t;
7195 }
7196 
7197 /* Build variant of function type ORIG_TYPE skipping ARGS_TO_SKIP.  */
7198 
7199 tree
7200 build_function_type_skip_args (tree orig_type, bitmap args_to_skip)
7201 {
7202   tree new_type = NULL;
7203   tree args, new_args = NULL, t;
7204   tree new_reversed;
7205   int i = 0;
7206 
7207   for (args = TYPE_ARG_TYPES (orig_type); args && args != void_list_node;
7208        args = TREE_CHAIN (args), i++)
7209     if (!bitmap_bit_p (args_to_skip, i))
7210       new_args = tree_cons (NULL_TREE, TREE_VALUE (args), new_args);
7211 
7212   new_reversed = nreverse (new_args);
7213   if (args)
7214     {
7215       if (new_reversed)
7216         TREE_CHAIN (new_args) = void_list_node;
7217       else
7218 	new_reversed = void_list_node;
7219     }
7220 
7221   /* Use copy_node to preserve as much as possible from original type
7222      (debug info, attribute lists etc.)
7223      Exception is METHOD_TYPEs must have THIS argument.
7224      When we are asked to remove it, we need to build new FUNCTION_TYPE
7225      instead.  */
7226   if (TREE_CODE (orig_type) != METHOD_TYPE
7227       || !bitmap_bit_p (args_to_skip, 0))
7228     {
7229       new_type = build_distinct_type_copy (orig_type);
7230       TYPE_ARG_TYPES (new_type) = new_reversed;
7231     }
7232   else
7233     {
7234       new_type
7235         = build_distinct_type_copy (build_function_type (TREE_TYPE (orig_type),
7236 							 new_reversed));
7237       TYPE_CONTEXT (new_type) = TYPE_CONTEXT (orig_type);
7238     }
7239 
7240   /* This is a new type, not a copy of an old type.  Need to reassociate
7241      variants.  We can handle everything except the main variant lazily.  */
7242   t = TYPE_MAIN_VARIANT (orig_type);
7243   if (orig_type != t)
7244     {
7245       TYPE_MAIN_VARIANT (new_type) = t;
7246       TYPE_NEXT_VARIANT (new_type) = TYPE_NEXT_VARIANT (t);
7247       TYPE_NEXT_VARIANT (t) = new_type;
7248     }
7249   else
7250     {
7251       TYPE_MAIN_VARIANT (new_type) = new_type;
7252       TYPE_NEXT_VARIANT (new_type) = NULL;
7253     }
7254   return new_type;
7255 }
7256 
7257 /* Build variant of function type ORIG_TYPE skipping ARGS_TO_SKIP.
7258 
7259    Arguments from DECL_ARGUMENTS list can't be removed now, since they are
7260    linked by TREE_CHAIN directly.  It is caller responsibility to eliminate
7261    them when they are being duplicated (i.e. copy_arguments_for_versioning).  */
7262 
7263 tree
7264 build_function_decl_skip_args (tree orig_decl, bitmap args_to_skip)
7265 {
7266   tree new_decl = copy_node (orig_decl);
7267   tree new_type;
7268 
7269   new_type = TREE_TYPE (orig_decl);
7270   if (prototype_p (new_type))
7271     new_type = build_function_type_skip_args (new_type, args_to_skip);
7272   TREE_TYPE (new_decl) = new_type;
7273 
7274   /* For declarations setting DECL_VINDEX (i.e. methods)
7275      we expect first argument to be THIS pointer.   */
7276   if (bitmap_bit_p (args_to_skip, 0))
7277     DECL_VINDEX (new_decl) = NULL_TREE;
7278 
7279   /* When signature changes, we need to clear builtin info.  */
7280   if (DECL_BUILT_IN (new_decl) && !bitmap_empty_p (args_to_skip))
7281     {
7282       DECL_BUILT_IN_CLASS (new_decl) = NOT_BUILT_IN;
7283       DECL_FUNCTION_CODE (new_decl) = (enum built_in_function) 0;
7284     }
7285   return new_decl;
7286 }
7287 
7288 /* Build a function type.  The RETURN_TYPE is the type returned by the
7289    function. If VAARGS is set, no void_type_node is appended to the
7290    the list. ARGP muse be alway be terminated be a NULL_TREE.  */
7291 
7292 static tree
7293 build_function_type_list_1 (bool vaargs, tree return_type, va_list argp)
7294 {
7295   tree t, args, last;
7296 
7297   t = va_arg (argp, tree);
7298   for (args = NULL_TREE; t != NULL_TREE; t = va_arg (argp, tree))
7299     args = tree_cons (NULL_TREE, t, args);
7300 
7301   if (vaargs)
7302     {
7303       last = args;
7304       if (args != NULL_TREE)
7305 	args = nreverse (args);
7306       gcc_assert (args != NULL_TREE && last != void_list_node);
7307     }
7308   else if (args == NULL_TREE)
7309     args = void_list_node;
7310   else
7311     {
7312       last = args;
7313       args = nreverse (args);
7314       TREE_CHAIN (last) = void_list_node;
7315     }
7316   args = build_function_type (return_type, args);
7317 
7318   return args;
7319 }
7320 
7321 /* Build a function type.  The RETURN_TYPE is the type returned by the
7322    function.  If additional arguments are provided, they are
7323    additional argument types.  The list of argument types must always
7324    be terminated by NULL_TREE.  */
7325 
7326 tree
7327 build_function_type_list (tree return_type, ...)
7328 {
7329   tree args;
7330   va_list p;
7331 
7332   va_start (p, return_type);
7333   args = build_function_type_list_1 (false, return_type, p);
7334   va_end (p);
7335   return args;
7336 }
7337 
7338 /* Build a variable argument function type.  The RETURN_TYPE is the
7339    type returned by the function.  If additional arguments are provided,
7340    they are additional argument types.  The list of argument types must
7341    always be terminated by NULL_TREE.  */
7342 
7343 tree
7344 build_varargs_function_type_list (tree return_type, ...)
7345 {
7346   tree args;
7347   va_list p;
7348 
7349   va_start (p, return_type);
7350   args = build_function_type_list_1 (true, return_type, p);
7351   va_end (p);
7352 
7353   return args;
7354 }
7355 
7356 /* Build a METHOD_TYPE for a member of BASETYPE.  The RETTYPE (a TYPE)
7357    and ARGTYPES (a TREE_LIST) are the return type and arguments types
7358    for the method.  An implicit additional parameter (of type
7359    pointer-to-BASETYPE) is added to the ARGTYPES.  */
7360 
7361 tree
7362 build_method_type_directly (tree basetype,
7363 			    tree rettype,
7364 			    tree argtypes)
7365 {
7366   tree t;
7367   tree ptype;
7368   int hashcode = 0;
7369   bool any_structural_p, any_noncanonical_p;
7370   tree canon_argtypes;
7371 
7372   /* Make a node of the sort we want.  */
7373   t = make_node (METHOD_TYPE);
7374 
7375   TYPE_METHOD_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
7376   TREE_TYPE (t) = rettype;
7377   ptype = build_pointer_type (basetype);
7378 
7379   /* The actual arglist for this function includes a "hidden" argument
7380      which is "this".  Put it into the list of argument types.  */
7381   argtypes = tree_cons (NULL_TREE, ptype, argtypes);
7382   TYPE_ARG_TYPES (t) = argtypes;
7383 
7384   /* If we already have such a type, use the old one.  */
7385   hashcode = iterative_hash_object (TYPE_HASH (basetype), hashcode);
7386   hashcode = iterative_hash_object (TYPE_HASH (rettype), hashcode);
7387   hashcode = type_hash_list (argtypes, hashcode);
7388   t = type_hash_canon (hashcode, t);
7389 
7390   /* Set up the canonical type. */
7391   any_structural_p
7392     = (TYPE_STRUCTURAL_EQUALITY_P (basetype)
7393        || TYPE_STRUCTURAL_EQUALITY_P (rettype));
7394   any_noncanonical_p
7395     = (TYPE_CANONICAL (basetype) != basetype
7396        || TYPE_CANONICAL (rettype) != rettype);
7397   canon_argtypes = maybe_canonicalize_argtypes (TREE_CHAIN (argtypes),
7398 						&any_structural_p,
7399 						&any_noncanonical_p);
7400   if (any_structural_p)
7401     SET_TYPE_STRUCTURAL_EQUALITY (t);
7402   else if (any_noncanonical_p)
7403     TYPE_CANONICAL (t)
7404       = build_method_type_directly (TYPE_CANONICAL (basetype),
7405 				    TYPE_CANONICAL (rettype),
7406 				    canon_argtypes);
7407   if (!COMPLETE_TYPE_P (t))
7408     layout_type (t);
7409 
7410   return t;
7411 }
7412 
7413 /* Construct, lay out and return the type of methods belonging to class
7414    BASETYPE and whose arguments and values are described by TYPE.
7415    If that type exists already, reuse it.
7416    TYPE must be a FUNCTION_TYPE node.  */
7417 
7418 tree
7419 build_method_type (tree basetype, tree type)
7420 {
7421   gcc_assert (TREE_CODE (type) == FUNCTION_TYPE);
7422 
7423   return build_method_type_directly (basetype,
7424 				     TREE_TYPE (type),
7425 				     TYPE_ARG_TYPES (type));
7426 }
7427 
7428 /* Construct, lay out and return the type of offsets to a value
7429    of type TYPE, within an object of type BASETYPE.
7430    If a suitable offset type exists already, reuse it.  */
7431 
7432 tree
7433 build_offset_type (tree basetype, tree type)
7434 {
7435   tree t;
7436   hashval_t hashcode = 0;
7437 
7438   /* Make a node of the sort we want.  */
7439   t = make_node (OFFSET_TYPE);
7440 
7441   TYPE_OFFSET_BASETYPE (t) = TYPE_MAIN_VARIANT (basetype);
7442   TREE_TYPE (t) = type;
7443 
7444   /* If we already have such a type, use the old one.  */
7445   hashcode = iterative_hash_object (TYPE_HASH (basetype), hashcode);
7446   hashcode = iterative_hash_object (TYPE_HASH (type), hashcode);
7447   t = type_hash_canon (hashcode, t);
7448 
7449   if (!COMPLETE_TYPE_P (t))
7450     layout_type (t);
7451 
7452   if (TYPE_CANONICAL (t) == t)
7453     {
7454       if (TYPE_STRUCTURAL_EQUALITY_P (basetype)
7455 	  || TYPE_STRUCTURAL_EQUALITY_P (type))
7456 	SET_TYPE_STRUCTURAL_EQUALITY (t);
7457       else if (TYPE_CANONICAL (TYPE_MAIN_VARIANT (basetype)) != basetype
7458 	       || TYPE_CANONICAL (type) != type)
7459 	TYPE_CANONICAL (t)
7460 	  = build_offset_type (TYPE_CANONICAL (TYPE_MAIN_VARIANT (basetype)),
7461 			       TYPE_CANONICAL (type));
7462     }
7463 
7464   return t;
7465 }
7466 
7467 /* Create a complex type whose components are COMPONENT_TYPE.  */
7468 
7469 tree
7470 build_complex_type (tree component_type)
7471 {
7472   tree t;
7473   hashval_t hashcode;
7474 
7475   gcc_assert (INTEGRAL_TYPE_P (component_type)
7476 	      || SCALAR_FLOAT_TYPE_P (component_type)
7477 	      || FIXED_POINT_TYPE_P (component_type));
7478 
7479   /* Make a node of the sort we want.  */
7480   t = make_node (COMPLEX_TYPE);
7481 
7482   TREE_TYPE (t) = TYPE_MAIN_VARIANT (component_type);
7483 
7484   /* If we already have such a type, use the old one.  */
7485   hashcode = iterative_hash_object (TYPE_HASH (component_type), 0);
7486   t = type_hash_canon (hashcode, t);
7487 
7488   if (!COMPLETE_TYPE_P (t))
7489     layout_type (t);
7490 
7491   if (TYPE_CANONICAL (t) == t)
7492     {
7493       if (TYPE_STRUCTURAL_EQUALITY_P (component_type))
7494 	SET_TYPE_STRUCTURAL_EQUALITY (t);
7495       else if (TYPE_CANONICAL (component_type) != component_type)
7496 	TYPE_CANONICAL (t)
7497 	  = build_complex_type (TYPE_CANONICAL (component_type));
7498     }
7499 
7500   /* We need to create a name, since complex is a fundamental type.  */
7501   if (! TYPE_NAME (t))
7502     {
7503       const char *name;
7504       if (component_type == char_type_node)
7505 	name = "complex char";
7506       else if (component_type == signed_char_type_node)
7507 	name = "complex signed char";
7508       else if (component_type == unsigned_char_type_node)
7509 	name = "complex unsigned char";
7510       else if (component_type == short_integer_type_node)
7511 	name = "complex short int";
7512       else if (component_type == short_unsigned_type_node)
7513 	name = "complex short unsigned int";
7514       else if (component_type == integer_type_node)
7515 	name = "complex int";
7516       else if (component_type == unsigned_type_node)
7517 	name = "complex unsigned int";
7518       else if (component_type == long_integer_type_node)
7519 	name = "complex long int";
7520       else if (component_type == long_unsigned_type_node)
7521 	name = "complex long unsigned int";
7522       else if (component_type == long_long_integer_type_node)
7523 	name = "complex long long int";
7524       else if (component_type == long_long_unsigned_type_node)
7525 	name = "complex long long unsigned int";
7526       else
7527 	name = 0;
7528 
7529       if (name != 0)
7530 	TYPE_NAME (t) = build_decl (UNKNOWN_LOCATION, TYPE_DECL,
7531 	    			    get_identifier (name), t);
7532     }
7533 
7534   return build_qualified_type (t, TYPE_QUALS (component_type));
7535 }
7536 
7537 /* If TYPE is a real or complex floating-point type and the target
7538    does not directly support arithmetic on TYPE then return the wider
7539    type to be used for arithmetic on TYPE.  Otherwise, return
7540    NULL_TREE.  */
7541 
7542 tree
7543 excess_precision_type (tree type)
7544 {
7545   if (flag_excess_precision != EXCESS_PRECISION_FAST)
7546     {
7547       int flt_eval_method = TARGET_FLT_EVAL_METHOD;
7548       switch (TREE_CODE (type))
7549 	{
7550 	case REAL_TYPE:
7551 	  switch (flt_eval_method)
7552 	    {
7553 	    case 1:
7554 	      if (TYPE_MODE (type) == TYPE_MODE (float_type_node))
7555 		return double_type_node;
7556 	      break;
7557 	    case 2:
7558 	      if (TYPE_MODE (type) == TYPE_MODE (float_type_node)
7559 		  || TYPE_MODE (type) == TYPE_MODE (double_type_node))
7560 		return long_double_type_node;
7561 	      break;
7562 	    default:
7563 	      gcc_unreachable ();
7564 	    }
7565 	  break;
7566 	case COMPLEX_TYPE:
7567 	  if (TREE_CODE (TREE_TYPE (type)) != REAL_TYPE)
7568 	    return NULL_TREE;
7569 	  switch (flt_eval_method)
7570 	    {
7571 	    case 1:
7572 	      if (TYPE_MODE (TREE_TYPE (type)) == TYPE_MODE (float_type_node))
7573 		return complex_double_type_node;
7574 	      break;
7575 	    case 2:
7576 	      if (TYPE_MODE (TREE_TYPE (type)) == TYPE_MODE (float_type_node)
7577 		  || (TYPE_MODE (TREE_TYPE (type))
7578 		      == TYPE_MODE (double_type_node)))
7579 		return complex_long_double_type_node;
7580 	      break;
7581 	    default:
7582 	      gcc_unreachable ();
7583 	    }
7584 	  break;
7585 	default:
7586 	  break;
7587 	}
7588     }
7589   return NULL_TREE;
7590 }
7591 
7592 /* Return OP, stripped of any conversions to wider types as much as is safe.
7593    Converting the value back to OP's type makes a value equivalent to OP.
7594 
7595    If FOR_TYPE is nonzero, we return a value which, if converted to
7596    type FOR_TYPE, would be equivalent to converting OP to type FOR_TYPE.
7597 
7598    OP must have integer, real or enumeral type.  Pointers are not allowed!
7599 
7600    There are some cases where the obvious value we could return
7601    would regenerate to OP if converted to OP's type,
7602    but would not extend like OP to wider types.
7603    If FOR_TYPE indicates such extension is contemplated, we eschew such values.
7604    For example, if OP is (unsigned short)(signed char)-1,
7605    we avoid returning (signed char)-1 if FOR_TYPE is int,
7606    even though extending that to an unsigned short would regenerate OP,
7607    since the result of extending (signed char)-1 to (int)
7608    is different from (int) OP.  */
7609 
7610 tree
7611 get_unwidened (tree op, tree for_type)
7612 {
7613   /* Set UNS initially if converting OP to FOR_TYPE is a zero-extension.  */
7614   tree type = TREE_TYPE (op);
7615   unsigned final_prec
7616     = TYPE_PRECISION (for_type != 0 ? for_type : type);
7617   int uns
7618     = (for_type != 0 && for_type != type
7619        && final_prec > TYPE_PRECISION (type)
7620        && TYPE_UNSIGNED (type));
7621   tree win = op;
7622 
7623   while (CONVERT_EXPR_P (op))
7624     {
7625       int bitschange;
7626 
7627       /* TYPE_PRECISION on vector types has different meaning
7628 	 (TYPE_VECTOR_SUBPARTS) and casts from vectors are view conversions,
7629 	 so avoid them here.  */
7630       if (TREE_CODE (TREE_TYPE (TREE_OPERAND (op, 0))) == VECTOR_TYPE)
7631 	break;
7632 
7633       bitschange = TYPE_PRECISION (TREE_TYPE (op))
7634 		   - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0)));
7635 
7636       /* Truncations are many-one so cannot be removed.
7637 	 Unless we are later going to truncate down even farther.  */
7638       if (bitschange < 0
7639 	  && final_prec > TYPE_PRECISION (TREE_TYPE (op)))
7640 	break;
7641 
7642       /* See what's inside this conversion.  If we decide to strip it,
7643 	 we will set WIN.  */
7644       op = TREE_OPERAND (op, 0);
7645 
7646       /* If we have not stripped any zero-extensions (uns is 0),
7647 	 we can strip any kind of extension.
7648 	 If we have previously stripped a zero-extension,
7649 	 only zero-extensions can safely be stripped.
7650 	 Any extension can be stripped if the bits it would produce
7651 	 are all going to be discarded later by truncating to FOR_TYPE.  */
7652 
7653       if (bitschange > 0)
7654 	{
7655 	  if (! uns || final_prec <= TYPE_PRECISION (TREE_TYPE (op)))
7656 	    win = op;
7657 	  /* TYPE_UNSIGNED says whether this is a zero-extension.
7658 	     Let's avoid computing it if it does not affect WIN
7659 	     and if UNS will not be needed again.  */
7660 	  if ((uns
7661 	       || CONVERT_EXPR_P (op))
7662 	      && TYPE_UNSIGNED (TREE_TYPE (op)))
7663 	    {
7664 	      uns = 1;
7665 	      win = op;
7666 	    }
7667 	}
7668     }
7669 
7670   /* If we finally reach a constant see if it fits in for_type and
7671      in that case convert it.  */
7672   if (for_type
7673       && TREE_CODE (win) == INTEGER_CST
7674       && TREE_TYPE (win) != for_type
7675       && int_fits_type_p (win, for_type))
7676     win = fold_convert (for_type, win);
7677 
7678   return win;
7679 }
7680 
7681 /* Return OP or a simpler expression for a narrower value
7682    which can be sign-extended or zero-extended to give back OP.
7683    Store in *UNSIGNEDP_PTR either 1 if the value should be zero-extended
7684    or 0 if the value should be sign-extended.  */
7685 
7686 tree
7687 get_narrower (tree op, int *unsignedp_ptr)
7688 {
7689   int uns = 0;
7690   int first = 1;
7691   tree win = op;
7692   bool integral_p = INTEGRAL_TYPE_P (TREE_TYPE (op));
7693 
7694   while (TREE_CODE (op) == NOP_EXPR)
7695     {
7696       int bitschange
7697 	= (TYPE_PRECISION (TREE_TYPE (op))
7698 	   - TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (op, 0))));
7699 
7700       /* Truncations are many-one so cannot be removed.  */
7701       if (bitschange < 0)
7702 	break;
7703 
7704       /* See what's inside this conversion.  If we decide to strip it,
7705 	 we will set WIN.  */
7706 
7707       if (bitschange > 0)
7708 	{
7709 	  op = TREE_OPERAND (op, 0);
7710 	  /* An extension: the outermost one can be stripped,
7711 	     but remember whether it is zero or sign extension.  */
7712 	  if (first)
7713 	    uns = TYPE_UNSIGNED (TREE_TYPE (op));
7714 	  /* Otherwise, if a sign extension has been stripped,
7715 	     only sign extensions can now be stripped;
7716 	     if a zero extension has been stripped, only zero-extensions.  */
7717 	  else if (uns != TYPE_UNSIGNED (TREE_TYPE (op)))
7718 	    break;
7719 	  first = 0;
7720 	}
7721       else /* bitschange == 0 */
7722 	{
7723 	  /* A change in nominal type can always be stripped, but we must
7724 	     preserve the unsignedness.  */
7725 	  if (first)
7726 	    uns = TYPE_UNSIGNED (TREE_TYPE (op));
7727 	  first = 0;
7728 	  op = TREE_OPERAND (op, 0);
7729 	  /* Keep trying to narrow, but don't assign op to win if it
7730 	     would turn an integral type into something else.  */
7731 	  if (INTEGRAL_TYPE_P (TREE_TYPE (op)) != integral_p)
7732 	    continue;
7733 	}
7734 
7735       win = op;
7736     }
7737 
7738   if (TREE_CODE (op) == COMPONENT_REF
7739       /* Since type_for_size always gives an integer type.  */
7740       && TREE_CODE (TREE_TYPE (op)) != REAL_TYPE
7741       && TREE_CODE (TREE_TYPE (op)) != FIXED_POINT_TYPE
7742       /* Ensure field is laid out already.  */
7743       && DECL_SIZE (TREE_OPERAND (op, 1)) != 0
7744       && host_integerp (DECL_SIZE (TREE_OPERAND (op, 1)), 1))
7745     {
7746       unsigned HOST_WIDE_INT innerprec
7747 	= tree_low_cst (DECL_SIZE (TREE_OPERAND (op, 1)), 1);
7748       int unsignedp = (DECL_UNSIGNED (TREE_OPERAND (op, 1))
7749 		       || TYPE_UNSIGNED (TREE_TYPE (TREE_OPERAND (op, 1))));
7750       tree type = lang_hooks.types.type_for_size (innerprec, unsignedp);
7751 
7752       /* We can get this structure field in a narrower type that fits it,
7753 	 but the resulting extension to its nominal type (a fullword type)
7754 	 must satisfy the same conditions as for other extensions.
7755 
7756 	 Do this only for fields that are aligned (not bit-fields),
7757 	 because when bit-field insns will be used there is no
7758 	 advantage in doing this.  */
7759 
7760       if (innerprec < TYPE_PRECISION (TREE_TYPE (op))
7761 	  && ! DECL_BIT_FIELD (TREE_OPERAND (op, 1))
7762 	  && (first || uns == DECL_UNSIGNED (TREE_OPERAND (op, 1)))
7763 	  && type != 0)
7764 	{
7765 	  if (first)
7766 	    uns = DECL_UNSIGNED (TREE_OPERAND (op, 1));
7767 	  win = fold_convert (type, op);
7768 	}
7769     }
7770 
7771   *unsignedp_ptr = uns;
7772   return win;
7773 }
7774 
7775 /* Nonzero if integer constant C has a value that is permissible
7776    for type TYPE (an INTEGER_TYPE).  */
7777 
7778 int
7779 int_fits_type_p (const_tree c, const_tree type)
7780 {
7781   tree type_low_bound, type_high_bound;
7782   bool ok_for_low_bound, ok_for_high_bound, unsc;
7783   double_int dc, dd;
7784 
7785   dc = tree_to_double_int (c);
7786   unsc = TYPE_UNSIGNED (TREE_TYPE (c));
7787 
7788   if (TREE_CODE (TREE_TYPE (c)) == INTEGER_TYPE
7789       && TYPE_IS_SIZETYPE (TREE_TYPE (c))
7790       && unsc)
7791     /* So c is an unsigned integer whose type is sizetype and type is not.
7792        sizetype'd integers are sign extended even though they are
7793        unsigned. If the integer value fits in the lower end word of c,
7794        and if the higher end word has all its bits set to 1, that
7795        means the higher end bits are set to 1 only for sign extension.
7796        So let's convert c into an equivalent zero extended unsigned
7797        integer.  */
7798     dc = double_int_zext (dc, TYPE_PRECISION (TREE_TYPE (c)));
7799 
7800 retry:
7801   type_low_bound = TYPE_MIN_VALUE (type);
7802   type_high_bound = TYPE_MAX_VALUE (type);
7803 
7804   /* If at least one bound of the type is a constant integer, we can check
7805      ourselves and maybe make a decision. If no such decision is possible, but
7806      this type is a subtype, try checking against that.  Otherwise, use
7807      fit_double_type, which checks against the precision.
7808 
7809      Compute the status for each possibly constant bound, and return if we see
7810      one does not match. Use ok_for_xxx_bound for this purpose, assigning -1
7811      for "unknown if constant fits", 0 for "constant known *not* to fit" and 1
7812      for "constant known to fit".  */
7813 
7814   /* Check if c >= type_low_bound.  */
7815   if (type_low_bound && TREE_CODE (type_low_bound) == INTEGER_CST)
7816     {
7817       dd = tree_to_double_int (type_low_bound);
7818       if (TREE_CODE (type) == INTEGER_TYPE
7819 	  && TYPE_IS_SIZETYPE (type)
7820 	  && TYPE_UNSIGNED (type))
7821 	dd = double_int_zext (dd, TYPE_PRECISION (type));
7822       if (unsc != TYPE_UNSIGNED (TREE_TYPE (type_low_bound)))
7823 	{
7824 	  int c_neg = (!unsc && double_int_negative_p (dc));
7825 	  int t_neg = (unsc && double_int_negative_p (dd));
7826 
7827 	  if (c_neg && !t_neg)
7828 	    return 0;
7829 	  if ((c_neg || !t_neg) && double_int_ucmp (dc, dd) < 0)
7830 	    return 0;
7831 	}
7832       else if (double_int_cmp (dc, dd, unsc) < 0)
7833 	return 0;
7834       ok_for_low_bound = true;
7835     }
7836   else
7837     ok_for_low_bound = false;
7838 
7839   /* Check if c <= type_high_bound.  */
7840   if (type_high_bound && TREE_CODE (type_high_bound) == INTEGER_CST)
7841     {
7842       dd = tree_to_double_int (type_high_bound);
7843       if (TREE_CODE (type) == INTEGER_TYPE
7844 	  && TYPE_IS_SIZETYPE (type)
7845 	  && TYPE_UNSIGNED (type))
7846 	dd = double_int_zext (dd, TYPE_PRECISION (type));
7847       if (unsc != TYPE_UNSIGNED (TREE_TYPE (type_high_bound)))
7848 	{
7849 	  int c_neg = (!unsc && double_int_negative_p (dc));
7850 	  int t_neg = (unsc && double_int_negative_p (dd));
7851 
7852 	  if (t_neg && !c_neg)
7853 	    return 0;
7854 	  if ((t_neg || !c_neg) && double_int_ucmp (dc, dd) > 0)
7855 	    return 0;
7856 	}
7857       else if (double_int_cmp (dc, dd, unsc) > 0)
7858 	return 0;
7859       ok_for_high_bound = true;
7860     }
7861   else
7862     ok_for_high_bound = false;
7863 
7864   /* If the constant fits both bounds, the result is known.  */
7865   if (ok_for_low_bound && ok_for_high_bound)
7866     return 1;
7867 
7868   /* Perform some generic filtering which may allow making a decision
7869      even if the bounds are not constant.  First, negative integers
7870      never fit in unsigned types, */
7871   if (TYPE_UNSIGNED (type) && !unsc && double_int_negative_p (dc))
7872     return 0;
7873 
7874   /* Second, narrower types always fit in wider ones.  */
7875   if (TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (c)))
7876     return 1;
7877 
7878   /* Third, unsigned integers with top bit set never fit signed types.  */
7879   if (! TYPE_UNSIGNED (type) && unsc)
7880     {
7881       int prec = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (c))) - 1;
7882       if (prec < HOST_BITS_PER_WIDE_INT)
7883 	{
7884 	  if (((((unsigned HOST_WIDE_INT) 1) << prec) & dc.low) != 0)
7885 	    return 0;
7886         }
7887       else if (((((unsigned HOST_WIDE_INT) 1)
7888 		 << (prec - HOST_BITS_PER_WIDE_INT)) & dc.high) != 0)
7889 	return 0;
7890     }
7891 
7892   /* If we haven't been able to decide at this point, there nothing more we
7893      can check ourselves here.  Look at the base type if we have one and it
7894      has the same precision.  */
7895   if (TREE_CODE (type) == INTEGER_TYPE
7896       && TREE_TYPE (type) != 0
7897       && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (type)))
7898     {
7899       type = TREE_TYPE (type);
7900       goto retry;
7901     }
7902 
7903   /* Or to fit_double_type, if nothing else.  */
7904   return !fit_double_type (dc.low, dc.high, &dc.low, &dc.high, type);
7905 }
7906 
7907 /* Stores bounds of an integer TYPE in MIN and MAX.  If TYPE has non-constant
7908    bounds or is a POINTER_TYPE, the maximum and/or minimum values that can be
7909    represented (assuming two's-complement arithmetic) within the bit
7910    precision of the type are returned instead.  */
7911 
7912 void
7913 get_type_static_bounds (const_tree type, mpz_t min, mpz_t max)
7914 {
7915   if (!POINTER_TYPE_P (type) && TYPE_MIN_VALUE (type)
7916       && TREE_CODE (TYPE_MIN_VALUE (type)) == INTEGER_CST)
7917     mpz_set_double_int (min, tree_to_double_int (TYPE_MIN_VALUE (type)),
7918 			TYPE_UNSIGNED (type));
7919   else
7920     {
7921       if (TYPE_UNSIGNED (type))
7922 	mpz_set_ui (min, 0);
7923       else
7924 	{
7925 	  double_int mn;
7926 	  mn = double_int_mask (TYPE_PRECISION (type) - 1);
7927 	  mn = double_int_sext (double_int_add (mn, double_int_one),
7928 				TYPE_PRECISION (type));
7929 	  mpz_set_double_int (min, mn, false);
7930 	}
7931     }
7932 
7933   if (!POINTER_TYPE_P (type) && TYPE_MAX_VALUE (type)
7934       && TREE_CODE (TYPE_MAX_VALUE (type)) == INTEGER_CST)
7935     mpz_set_double_int (max, tree_to_double_int (TYPE_MAX_VALUE (type)),
7936 			TYPE_UNSIGNED (type));
7937   else
7938     {
7939       if (TYPE_UNSIGNED (type))
7940 	mpz_set_double_int (max, double_int_mask (TYPE_PRECISION (type)),
7941 			    true);
7942       else
7943 	mpz_set_double_int (max, double_int_mask (TYPE_PRECISION (type) - 1),
7944 			    true);
7945     }
7946 }
7947 
7948 /* Return true if VAR is an automatic variable defined in function FN.  */
7949 
7950 bool
7951 auto_var_in_fn_p (const_tree var, const_tree fn)
7952 {
7953   return (DECL_P (var) && DECL_CONTEXT (var) == fn
7954 	  && ((((TREE_CODE (var) == VAR_DECL && ! DECL_EXTERNAL (var))
7955 		|| TREE_CODE (var) == PARM_DECL)
7956 	       && ! TREE_STATIC (var))
7957 	      || TREE_CODE (var) == LABEL_DECL
7958 	      || TREE_CODE (var) == RESULT_DECL));
7959 }
7960 
7961 /* Subprogram of following function.  Called by walk_tree.
7962 
7963    Return *TP if it is an automatic variable or parameter of the
7964    function passed in as DATA.  */
7965 
7966 static tree
7967 find_var_from_fn (tree *tp, int *walk_subtrees, void *data)
7968 {
7969   tree fn = (tree) data;
7970 
7971   if (TYPE_P (*tp))
7972     *walk_subtrees = 0;
7973 
7974   else if (DECL_P (*tp)
7975 	   && auto_var_in_fn_p (*tp, fn))
7976     return *tp;
7977 
7978   return NULL_TREE;
7979 }
7980 
7981 /* Returns true if T is, contains, or refers to a type with variable
7982    size.  For METHOD_TYPEs and FUNCTION_TYPEs we exclude the
7983    arguments, but not the return type.  If FN is nonzero, only return
7984    true if a modifier of the type or position of FN is a variable or
7985    parameter inside FN.
7986 
7987    This concept is more general than that of C99 'variably modified types':
7988    in C99, a struct type is never variably modified because a VLA may not
7989    appear as a structure member.  However, in GNU C code like:
7990 
7991      struct S { int i[f()]; };
7992 
7993    is valid, and other languages may define similar constructs.  */
7994 
7995 bool
7996 variably_modified_type_p (tree type, tree fn)
7997 {
7998   tree t;
7999 
8000 /* Test if T is either variable (if FN is zero) or an expression containing
8001    a variable in FN.  */
8002 #define RETURN_TRUE_IF_VAR(T)						\
8003   do { tree _t = (T);							\
8004     if (_t && _t != error_mark_node && TREE_CODE (_t) != INTEGER_CST	\
8005         && (!fn || walk_tree (&_t, find_var_from_fn, fn, NULL)))	\
8006       return true;  } while (0)
8007 
8008   if (type == error_mark_node)
8009     return false;
8010 
8011   /* If TYPE itself has variable size, it is variably modified.  */
8012   RETURN_TRUE_IF_VAR (TYPE_SIZE (type));
8013   RETURN_TRUE_IF_VAR (TYPE_SIZE_UNIT (type));
8014 
8015   switch (TREE_CODE (type))
8016     {
8017     case POINTER_TYPE:
8018     case REFERENCE_TYPE:
8019     case VECTOR_TYPE:
8020       if (variably_modified_type_p (TREE_TYPE (type), fn))
8021 	return true;
8022       break;
8023 
8024     case FUNCTION_TYPE:
8025     case METHOD_TYPE:
8026       /* If TYPE is a function type, it is variably modified if the
8027 	 return type is variably modified.  */
8028       if (variably_modified_type_p (TREE_TYPE (type), fn))
8029 	  return true;
8030       break;
8031 
8032     case INTEGER_TYPE:
8033     case REAL_TYPE:
8034     case FIXED_POINT_TYPE:
8035     case ENUMERAL_TYPE:
8036     case BOOLEAN_TYPE:
8037       /* Scalar types are variably modified if their end points
8038 	 aren't constant.  */
8039       RETURN_TRUE_IF_VAR (TYPE_MIN_VALUE (type));
8040       RETURN_TRUE_IF_VAR (TYPE_MAX_VALUE (type));
8041       break;
8042 
8043     case RECORD_TYPE:
8044     case UNION_TYPE:
8045     case QUAL_UNION_TYPE:
8046       /* We can't see if any of the fields are variably-modified by the
8047 	 definition we normally use, since that would produce infinite
8048 	 recursion via pointers.  */
8049       /* This is variably modified if some field's type is.  */
8050       for (t = TYPE_FIELDS (type); t; t = TREE_CHAIN (t))
8051 	if (TREE_CODE (t) == FIELD_DECL)
8052 	  {
8053 	    RETURN_TRUE_IF_VAR (DECL_FIELD_OFFSET (t));
8054 	    RETURN_TRUE_IF_VAR (DECL_SIZE (t));
8055 	    RETURN_TRUE_IF_VAR (DECL_SIZE_UNIT (t));
8056 
8057 	    if (TREE_CODE (type) == QUAL_UNION_TYPE)
8058 	      RETURN_TRUE_IF_VAR (DECL_QUALIFIER (t));
8059 	  }
8060 	break;
8061 
8062     case ARRAY_TYPE:
8063       /* Do not call ourselves to avoid infinite recursion.  This is
8064 	 variably modified if the element type is.  */
8065       RETURN_TRUE_IF_VAR (TYPE_SIZE (TREE_TYPE (type)));
8066       RETURN_TRUE_IF_VAR (TYPE_SIZE_UNIT (TREE_TYPE (type)));
8067       break;
8068 
8069     default:
8070       break;
8071     }
8072 
8073   /* The current language may have other cases to check, but in general,
8074      all other types are not variably modified.  */
8075   return lang_hooks.tree_inlining.var_mod_type_p (type, fn);
8076 
8077 #undef RETURN_TRUE_IF_VAR
8078 }
8079 
8080 /* Given a DECL or TYPE, return the scope in which it was declared, or
8081    NULL_TREE if there is no containing scope.  */
8082 
8083 tree
8084 get_containing_scope (const_tree t)
8085 {
8086   return (TYPE_P (t) ? TYPE_CONTEXT (t) : DECL_CONTEXT (t));
8087 }
8088 
8089 /* Return the innermost context enclosing DECL that is
8090    a FUNCTION_DECL, or zero if none.  */
8091 
8092 tree
8093 decl_function_context (const_tree decl)
8094 {
8095   tree context;
8096 
8097   if (TREE_CODE (decl) == ERROR_MARK)
8098     return 0;
8099 
8100   /* C++ virtual functions use DECL_CONTEXT for the class of the vtable
8101      where we look up the function at runtime.  Such functions always take
8102      a first argument of type 'pointer to real context'.
8103 
8104      C++ should really be fixed to use DECL_CONTEXT for the real context,
8105      and use something else for the "virtual context".  */
8106   else if (TREE_CODE (decl) == FUNCTION_DECL && DECL_VINDEX (decl))
8107     context
8108       = TYPE_MAIN_VARIANT
8109 	(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (decl)))));
8110   else
8111     context = DECL_CONTEXT (decl);
8112 
8113   while (context && TREE_CODE (context) != FUNCTION_DECL)
8114     {
8115       if (TREE_CODE (context) == BLOCK)
8116 	context = BLOCK_SUPERCONTEXT (context);
8117       else
8118 	context = get_containing_scope (context);
8119     }
8120 
8121   return context;
8122 }
8123 
8124 /* Return the innermost context enclosing DECL that is
8125    a RECORD_TYPE, UNION_TYPE or QUAL_UNION_TYPE, or zero if none.
8126    TYPE_DECLs and FUNCTION_DECLs are transparent to this function.  */
8127 
8128 tree
8129 decl_type_context (const_tree decl)
8130 {
8131   tree context = DECL_CONTEXT (decl);
8132 
8133   while (context)
8134     switch (TREE_CODE (context))
8135       {
8136       case NAMESPACE_DECL:
8137       case TRANSLATION_UNIT_DECL:
8138 	return NULL_TREE;
8139 
8140       case RECORD_TYPE:
8141       case UNION_TYPE:
8142       case QUAL_UNION_TYPE:
8143 	return context;
8144 
8145       case TYPE_DECL:
8146       case FUNCTION_DECL:
8147 	context = DECL_CONTEXT (context);
8148 	break;
8149 
8150       case BLOCK:
8151 	context = BLOCK_SUPERCONTEXT (context);
8152 	break;
8153 
8154       default:
8155 	gcc_unreachable ();
8156       }
8157 
8158   return NULL_TREE;
8159 }
8160 
8161 /* CALL is a CALL_EXPR.  Return the declaration for the function
8162    called, or NULL_TREE if the called function cannot be
8163    determined.  */
8164 
8165 tree
8166 get_callee_fndecl (const_tree call)
8167 {
8168   tree addr;
8169 
8170   if (call == error_mark_node)
8171     return error_mark_node;
8172 
8173   /* It's invalid to call this function with anything but a
8174      CALL_EXPR.  */
8175   gcc_assert (TREE_CODE (call) == CALL_EXPR);
8176 
8177   /* The first operand to the CALL is the address of the function
8178      called.  */
8179   addr = CALL_EXPR_FN (call);
8180 
8181   STRIP_NOPS (addr);
8182 
8183   /* If this is a readonly function pointer, extract its initial value.  */
8184   if (DECL_P (addr) && TREE_CODE (addr) != FUNCTION_DECL
8185       && TREE_READONLY (addr) && ! TREE_THIS_VOLATILE (addr)
8186       && DECL_INITIAL (addr))
8187     addr = DECL_INITIAL (addr);
8188 
8189   /* If the address is just `&f' for some function `f', then we know
8190      that `f' is being called.  */
8191   if (TREE_CODE (addr) == ADDR_EXPR
8192       && TREE_CODE (TREE_OPERAND (addr, 0)) == FUNCTION_DECL)
8193     return TREE_OPERAND (addr, 0);
8194 
8195   /* We couldn't figure out what was being called.  */
8196   return NULL_TREE;
8197 }
8198 
8199 /* Print debugging information about tree nodes generated during the compile,
8200    and any language-specific information.  */
8201 
8202 void
8203 dump_tree_statistics (void)
8204 {
8205 #ifdef GATHER_STATISTICS
8206   int i;
8207   int total_nodes, total_bytes;
8208 #endif
8209 
8210   fprintf (stderr, "\n??? tree nodes created\n\n");
8211 #ifdef GATHER_STATISTICS
8212   fprintf (stderr, "Kind                   Nodes      Bytes\n");
8213   fprintf (stderr, "---------------------------------------\n");
8214   total_nodes = total_bytes = 0;
8215   for (i = 0; i < (int) all_kinds; i++)
8216     {
8217       fprintf (stderr, "%-20s %7d %10d\n", tree_node_kind_names[i],
8218 	       tree_node_counts[i], tree_node_sizes[i]);
8219       total_nodes += tree_node_counts[i];
8220       total_bytes += tree_node_sizes[i];
8221     }
8222   fprintf (stderr, "---------------------------------------\n");
8223   fprintf (stderr, "%-20s %7d %10d\n", "Total", total_nodes, total_bytes);
8224   fprintf (stderr, "---------------------------------------\n");
8225   ssanames_print_statistics ();
8226   phinodes_print_statistics ();
8227 #else
8228   fprintf (stderr, "(No per-node statistics)\n");
8229 #endif
8230   print_type_hash_statistics ();
8231   print_debug_expr_statistics ();
8232   print_value_expr_statistics ();
8233   lang_hooks.print_statistics ();
8234 }
8235 
8236 #define FILE_FUNCTION_FORMAT "_GLOBAL__%s_%s"
8237 
8238 /* Generate a crc32 of a string.  */
8239 
8240 unsigned
8241 crc32_string (unsigned chksum, const char *string)
8242 {
8243   do
8244     {
8245       unsigned value = *string << 24;
8246       unsigned ix;
8247 
8248       for (ix = 8; ix--; value <<= 1)
8249   	{
8250   	  unsigned feedback;
8251 
8252   	  feedback = (value ^ chksum) & 0x80000000 ? 0x04c11db7 : 0;
8253  	  chksum <<= 1;
8254  	  chksum ^= feedback;
8255   	}
8256     }
8257   while (*string++);
8258   return chksum;
8259 }
8260 
8261 /* P is a string that will be used in a symbol.  Mask out any characters
8262    that are not valid in that context.  */
8263 
8264 void
8265 clean_symbol_name (char *p)
8266 {
8267   for (; *p; p++)
8268     if (! (ISALNUM (*p)
8269 #ifndef NO_DOLLAR_IN_LABEL	/* this for `$'; unlikely, but... -- kr */
8270 	    || *p == '$'
8271 #endif
8272 #ifndef NO_DOT_IN_LABEL		/* this for `.'; unlikely, but...  */
8273 	    || *p == '.'
8274 #endif
8275 	   ))
8276       *p = '_';
8277 }
8278 
8279 /* Generate a name for a special-purpose function function.
8280    The generated name may need to be unique across the whole link.
8281    TYPE is some string to identify the purpose of this function to the
8282    linker or collect2; it must start with an uppercase letter,
8283    one of:
8284    I - for constructors
8285    D - for destructors
8286    N - for C++ anonymous namespaces
8287    F - for DWARF unwind frame information.  */
8288 
8289 tree
8290 get_file_function_name (const char *type)
8291 {
8292   char *buf;
8293   const char *p;
8294   char *q;
8295 
8296   /* If we already have a name we know to be unique, just use that.  */
8297   if (first_global_object_name)
8298     p = q = ASTRDUP (first_global_object_name);
8299   /* If the target is handling the constructors/destructors, they
8300      will be local to this file and the name is only necessary for
8301      debugging purposes.  */
8302   else if ((type[0] == 'I' || type[0] == 'D') && targetm.have_ctors_dtors)
8303     {
8304       const char *file = main_input_filename;
8305       if (! file)
8306 	file = input_filename;
8307       /* Just use the file's basename, because the full pathname
8308 	 might be quite long.  */
8309       p = strrchr (file, '/');
8310       if (p)
8311 	p++;
8312       else
8313 	p = file;
8314       p = q = ASTRDUP (p);
8315     }
8316   else
8317     {
8318       /* Otherwise, the name must be unique across the entire link.
8319 	 We don't have anything that we know to be unique to this translation
8320 	 unit, so use what we do have and throw in some randomness.  */
8321       unsigned len;
8322       const char *name = weak_global_object_name;
8323       const char *file = main_input_filename;
8324 
8325       if (! name)
8326 	name = "";
8327       if (! file)
8328 	file = input_filename;
8329 
8330       len = strlen (file);
8331       q = (char *) alloca (9 * 2 + len + 1);
8332       memcpy (q, file, len + 1);
8333 
8334       sprintf (q + len, "_%08X_%08X", crc32_string (0, name),
8335 	       crc32_string (0, get_random_seed (false)));
8336 
8337       p = q;
8338     }
8339 
8340   clean_symbol_name (q);
8341   buf = (char *) alloca (sizeof (FILE_FUNCTION_FORMAT) + strlen (p)
8342 			 + strlen (type));
8343 
8344   /* Set up the name of the file-level functions we may need.
8345      Use a global object (which is already required to be unique over
8346      the program) rather than the file name (which imposes extra
8347      constraints).  */
8348   sprintf (buf, FILE_FUNCTION_FORMAT, type, p);
8349 
8350   return get_identifier (buf);
8351 }
8352 
8353 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
8354 
8355 /* Complain that the tree code of NODE does not match the expected 0
8356    terminated list of trailing codes. The trailing code list can be
8357    empty, for a more vague error message.  FILE, LINE, and FUNCTION
8358    are of the caller.  */
8359 
8360 void
8361 tree_check_failed (const_tree node, const char *file,
8362 		   int line, const char *function, ...)
8363 {
8364   va_list args;
8365   const char *buffer;
8366   unsigned length = 0;
8367   int code;
8368 
8369   va_start (args, function);
8370   while ((code = va_arg (args, int)))
8371     length += 4 + strlen (tree_code_name[code]);
8372   va_end (args);
8373   if (length)
8374     {
8375       char *tmp;
8376       va_start (args, function);
8377       length += strlen ("expected ");
8378       buffer = tmp = (char *) alloca (length);
8379       length = 0;
8380       while ((code = va_arg (args, int)))
8381 	{
8382 	  const char *prefix = length ? " or " : "expected ";
8383 
8384 	  strcpy (tmp + length, prefix);
8385 	  length += strlen (prefix);
8386 	  strcpy (tmp + length, tree_code_name[code]);
8387 	  length += strlen (tree_code_name[code]);
8388 	}
8389       va_end (args);
8390     }
8391   else
8392     buffer = "unexpected node";
8393 
8394   internal_error ("tree check: %s, have %s in %s, at %s:%d",
8395 		  buffer, tree_code_name[TREE_CODE (node)],
8396 		  function, trim_filename (file), line);
8397 }
8398 
8399 /* Complain that the tree code of NODE does match the expected 0
8400    terminated list of trailing codes. FILE, LINE, and FUNCTION are of
8401    the caller.  */
8402 
8403 void
8404 tree_not_check_failed (const_tree node, const char *file,
8405 		       int line, const char *function, ...)
8406 {
8407   va_list args;
8408   char *buffer;
8409   unsigned length = 0;
8410   int code;
8411 
8412   va_start (args, function);
8413   while ((code = va_arg (args, int)))
8414     length += 4 + strlen (tree_code_name[code]);
8415   va_end (args);
8416   va_start (args, function);
8417   buffer = (char *) alloca (length);
8418   length = 0;
8419   while ((code = va_arg (args, int)))
8420     {
8421       if (length)
8422 	{
8423 	  strcpy (buffer + length, " or ");
8424 	  length += 4;
8425 	}
8426       strcpy (buffer + length, tree_code_name[code]);
8427       length += strlen (tree_code_name[code]);
8428     }
8429   va_end (args);
8430 
8431   internal_error ("tree check: expected none of %s, have %s in %s, at %s:%d",
8432 		  buffer, tree_code_name[TREE_CODE (node)],
8433 		  function, trim_filename (file), line);
8434 }
8435 
8436 /* Similar to tree_check_failed, except that we check for a class of tree
8437    code, given in CL.  */
8438 
8439 void
8440 tree_class_check_failed (const_tree node, const enum tree_code_class cl,
8441 			 const char *file, int line, const char *function)
8442 {
8443   internal_error
8444     ("tree check: expected class %qs, have %qs (%s) in %s, at %s:%d",
8445      TREE_CODE_CLASS_STRING (cl),
8446      TREE_CODE_CLASS_STRING (TREE_CODE_CLASS (TREE_CODE (node))),
8447      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
8448 }
8449 
8450 /* Similar to tree_check_failed, except that instead of specifying a
8451    dozen codes, use the knowledge that they're all sequential.  */
8452 
8453 void
8454 tree_range_check_failed (const_tree node, const char *file, int line,
8455 			 const char *function, enum tree_code c1,
8456 			 enum tree_code c2)
8457 {
8458   char *buffer;
8459   unsigned length = 0;
8460   unsigned int c;
8461 
8462   for (c = c1; c <= c2; ++c)
8463     length += 4 + strlen (tree_code_name[c]);
8464 
8465   length += strlen ("expected ");
8466   buffer = (char *) alloca (length);
8467   length = 0;
8468 
8469   for (c = c1; c <= c2; ++c)
8470     {
8471       const char *prefix = length ? " or " : "expected ";
8472 
8473       strcpy (buffer + length, prefix);
8474       length += strlen (prefix);
8475       strcpy (buffer + length, tree_code_name[c]);
8476       length += strlen (tree_code_name[c]);
8477     }
8478 
8479   internal_error ("tree check: %s, have %s in %s, at %s:%d",
8480 		  buffer, tree_code_name[TREE_CODE (node)],
8481 		  function, trim_filename (file), line);
8482 }
8483 
8484 
8485 /* Similar to tree_check_failed, except that we check that a tree does
8486    not have the specified code, given in CL.  */
8487 
8488 void
8489 tree_not_class_check_failed (const_tree node, const enum tree_code_class cl,
8490 			     const char *file, int line, const char *function)
8491 {
8492   internal_error
8493     ("tree check: did not expect class %qs, have %qs (%s) in %s, at %s:%d",
8494      TREE_CODE_CLASS_STRING (cl),
8495      TREE_CODE_CLASS_STRING (TREE_CODE_CLASS (TREE_CODE (node))),
8496      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
8497 }
8498 
8499 
8500 /* Similar to tree_check_failed but applied to OMP_CLAUSE codes.  */
8501 
8502 void
8503 omp_clause_check_failed (const_tree node, const char *file, int line,
8504                          const char *function, enum omp_clause_code code)
8505 {
8506   internal_error ("tree check: expected omp_clause %s, have %s in %s, at %s:%d",
8507 		  omp_clause_code_name[code], tree_code_name[TREE_CODE (node)],
8508 		  function, trim_filename (file), line);
8509 }
8510 
8511 
8512 /* Similar to tree_range_check_failed but applied to OMP_CLAUSE codes.  */
8513 
8514 void
8515 omp_clause_range_check_failed (const_tree node, const char *file, int line,
8516 			       const char *function, enum omp_clause_code c1,
8517 			       enum omp_clause_code c2)
8518 {
8519   char *buffer;
8520   unsigned length = 0;
8521   unsigned int c;
8522 
8523   for (c = c1; c <= c2; ++c)
8524     length += 4 + strlen (omp_clause_code_name[c]);
8525 
8526   length += strlen ("expected ");
8527   buffer = (char *) alloca (length);
8528   length = 0;
8529 
8530   for (c = c1; c <= c2; ++c)
8531     {
8532       const char *prefix = length ? " or " : "expected ";
8533 
8534       strcpy (buffer + length, prefix);
8535       length += strlen (prefix);
8536       strcpy (buffer + length, omp_clause_code_name[c]);
8537       length += strlen (omp_clause_code_name[c]);
8538     }
8539 
8540   internal_error ("tree check: %s, have %s in %s, at %s:%d",
8541 		  buffer, omp_clause_code_name[TREE_CODE (node)],
8542 		  function, trim_filename (file), line);
8543 }
8544 
8545 
8546 #undef DEFTREESTRUCT
8547 #define DEFTREESTRUCT(VAL, NAME) NAME,
8548 
8549 static const char *ts_enum_names[] = {
8550 #include "treestruct.def"
8551 };
8552 #undef DEFTREESTRUCT
8553 
8554 #define TS_ENUM_NAME(EN) (ts_enum_names[(EN)])
8555 
8556 /* Similar to tree_class_check_failed, except that we check for
8557    whether CODE contains the tree structure identified by EN.  */
8558 
8559 void
8560 tree_contains_struct_check_failed (const_tree node,
8561 				   const enum tree_node_structure_enum en,
8562 				   const char *file, int line,
8563 				   const char *function)
8564 {
8565   internal_error
8566     ("tree check: expected tree that contains %qs structure, have %qs in %s, at %s:%d",
8567      TS_ENUM_NAME(en),
8568      tree_code_name[TREE_CODE (node)], function, trim_filename (file), line);
8569 }
8570 
8571 
8572 /* Similar to above, except that the check is for the bounds of a TREE_VEC's
8573    (dynamically sized) vector.  */
8574 
8575 void
8576 tree_vec_elt_check_failed (int idx, int len, const char *file, int line,
8577 			   const char *function)
8578 {
8579   internal_error
8580     ("tree check: accessed elt %d of tree_vec with %d elts in %s, at %s:%d",
8581      idx + 1, len, function, trim_filename (file), line);
8582 }
8583 
8584 /* Similar to above, except that the check is for the bounds of the operand
8585    vector of an expression node EXP.  */
8586 
8587 void
8588 tree_operand_check_failed (int idx, const_tree exp, const char *file,
8589 			   int line, const char *function)
8590 {
8591   int code = TREE_CODE (exp);
8592   internal_error
8593     ("tree check: accessed operand %d of %s with %d operands in %s, at %s:%d",
8594      idx + 1, tree_code_name[code], TREE_OPERAND_LENGTH (exp),
8595      function, trim_filename (file), line);
8596 }
8597 
8598 /* Similar to above, except that the check is for the number of
8599    operands of an OMP_CLAUSE node.  */
8600 
8601 void
8602 omp_clause_operand_check_failed (int idx, const_tree t, const char *file,
8603 			         int line, const char *function)
8604 {
8605   internal_error
8606     ("tree check: accessed operand %d of omp_clause %s with %d operands "
8607      "in %s, at %s:%d", idx + 1, omp_clause_code_name[OMP_CLAUSE_CODE (t)],
8608      omp_clause_num_ops [OMP_CLAUSE_CODE (t)], function,
8609      trim_filename (file), line);
8610 }
8611 #endif /* ENABLE_TREE_CHECKING */
8612 
8613 /* Create a new vector type node holding SUBPARTS units of type INNERTYPE,
8614    and mapped to the machine mode MODE.  Initialize its fields and build
8615    the information necessary for debugging output.  */
8616 
8617 static tree
8618 make_vector_type (tree innertype, int nunits, enum machine_mode mode)
8619 {
8620   tree t;
8621   hashval_t hashcode = 0;
8622 
8623   t = make_node (VECTOR_TYPE);
8624   TREE_TYPE (t) = TYPE_MAIN_VARIANT (innertype);
8625   SET_TYPE_VECTOR_SUBPARTS (t, nunits);
8626   SET_TYPE_MODE (t, mode);
8627 
8628   if (TYPE_STRUCTURAL_EQUALITY_P (innertype))
8629     SET_TYPE_STRUCTURAL_EQUALITY (t);
8630   else if (TYPE_CANONICAL (innertype) != innertype
8631 	   || mode != VOIDmode)
8632     TYPE_CANONICAL (t)
8633       = make_vector_type (TYPE_CANONICAL (innertype), nunits, VOIDmode);
8634 
8635   layout_type (t);
8636 
8637   {
8638     tree index = build_int_cst (NULL_TREE, nunits - 1);
8639     tree array = build_array_type (TYPE_MAIN_VARIANT (innertype),
8640 				   build_index_type (index));
8641     tree rt = make_node (RECORD_TYPE);
8642 
8643     TYPE_FIELDS (rt) = build_decl (UNKNOWN_LOCATION, FIELD_DECL,
8644 				   get_identifier ("f"), array);
8645     DECL_CONTEXT (TYPE_FIELDS (rt)) = rt;
8646     layout_type (rt);
8647     TYPE_DEBUG_REPRESENTATION_TYPE (t) = rt;
8648     /* In dwarfout.c, type lookup uses TYPE_UID numbers.  We want to output
8649        the representation type, and we want to find that die when looking up
8650        the vector type.  This is most easily achieved by making the TYPE_UID
8651        numbers equal.  */
8652     TYPE_UID (rt) = TYPE_UID (t);
8653   }
8654 
8655   hashcode = iterative_hash_host_wide_int (VECTOR_TYPE, hashcode);
8656   hashcode = iterative_hash_host_wide_int (nunits, hashcode);
8657   hashcode = iterative_hash_host_wide_int (mode, hashcode);
8658   hashcode = iterative_hash_object (TYPE_HASH (TREE_TYPE (t)), hashcode);
8659   t = type_hash_canon (hashcode, t);
8660 
8661   /* We have built a main variant, based on the main variant of the
8662      inner type. Use it to build the variant we return.  */
8663   if ((TYPE_ATTRIBUTES (innertype) || TYPE_QUALS (innertype))
8664       && TREE_TYPE (t) != innertype)
8665     return build_type_attribute_qual_variant (t,
8666 					      TYPE_ATTRIBUTES (innertype),
8667 					      TYPE_QUALS (innertype));
8668 
8669   return t;
8670 }
8671 
8672 static tree
8673 make_or_reuse_type (unsigned size, int unsignedp)
8674 {
8675   if (size == INT_TYPE_SIZE)
8676     return unsignedp ? unsigned_type_node : integer_type_node;
8677   if (size == CHAR_TYPE_SIZE)
8678     return unsignedp ? unsigned_char_type_node : signed_char_type_node;
8679   if (size == SHORT_TYPE_SIZE)
8680     return unsignedp ? short_unsigned_type_node : short_integer_type_node;
8681   if (size == LONG_TYPE_SIZE)
8682     return unsignedp ? long_unsigned_type_node : long_integer_type_node;
8683   if (size == LONG_LONG_TYPE_SIZE)
8684     return (unsignedp ? long_long_unsigned_type_node
8685             : long_long_integer_type_node);
8686 
8687   if (unsignedp)
8688     return make_unsigned_type (size);
8689   else
8690     return make_signed_type (size);
8691 }
8692 
8693 /* Create or reuse a fract type by SIZE, UNSIGNEDP, and SATP.  */
8694 
8695 static tree
8696 make_or_reuse_fract_type (unsigned size, int unsignedp, int satp)
8697 {
8698   if (satp)
8699     {
8700       if (size == SHORT_FRACT_TYPE_SIZE)
8701 	return unsignedp ? sat_unsigned_short_fract_type_node
8702 			 : sat_short_fract_type_node;
8703       if (size == FRACT_TYPE_SIZE)
8704 	return unsignedp ? sat_unsigned_fract_type_node : sat_fract_type_node;
8705       if (size == LONG_FRACT_TYPE_SIZE)
8706 	return unsignedp ? sat_unsigned_long_fract_type_node
8707 			 : sat_long_fract_type_node;
8708       if (size == LONG_LONG_FRACT_TYPE_SIZE)
8709 	return unsignedp ? sat_unsigned_long_long_fract_type_node
8710 			 : sat_long_long_fract_type_node;
8711     }
8712   else
8713     {
8714       if (size == SHORT_FRACT_TYPE_SIZE)
8715 	return unsignedp ? unsigned_short_fract_type_node
8716 			 : short_fract_type_node;
8717       if (size == FRACT_TYPE_SIZE)
8718 	return unsignedp ? unsigned_fract_type_node : fract_type_node;
8719       if (size == LONG_FRACT_TYPE_SIZE)
8720 	return unsignedp ? unsigned_long_fract_type_node
8721 			 : long_fract_type_node;
8722       if (size == LONG_LONG_FRACT_TYPE_SIZE)
8723 	return unsignedp ? unsigned_long_long_fract_type_node
8724 			 : long_long_fract_type_node;
8725     }
8726 
8727   return make_fract_type (size, unsignedp, satp);
8728 }
8729 
8730 /* Create or reuse an accum type by SIZE, UNSIGNEDP, and SATP.  */
8731 
8732 static tree
8733 make_or_reuse_accum_type (unsigned size, int unsignedp, int satp)
8734 {
8735   if (satp)
8736     {
8737       if (size == SHORT_ACCUM_TYPE_SIZE)
8738 	return unsignedp ? sat_unsigned_short_accum_type_node
8739 			 : sat_short_accum_type_node;
8740       if (size == ACCUM_TYPE_SIZE)
8741 	return unsignedp ? sat_unsigned_accum_type_node : sat_accum_type_node;
8742       if (size == LONG_ACCUM_TYPE_SIZE)
8743 	return unsignedp ? sat_unsigned_long_accum_type_node
8744 			 : sat_long_accum_type_node;
8745       if (size == LONG_LONG_ACCUM_TYPE_SIZE)
8746 	return unsignedp ? sat_unsigned_long_long_accum_type_node
8747 			 : sat_long_long_accum_type_node;
8748     }
8749   else
8750     {
8751       if (size == SHORT_ACCUM_TYPE_SIZE)
8752 	return unsignedp ? unsigned_short_accum_type_node
8753 			 : short_accum_type_node;
8754       if (size == ACCUM_TYPE_SIZE)
8755 	return unsignedp ? unsigned_accum_type_node : accum_type_node;
8756       if (size == LONG_ACCUM_TYPE_SIZE)
8757 	return unsignedp ? unsigned_long_accum_type_node
8758 			 : long_accum_type_node;
8759       if (size == LONG_LONG_ACCUM_TYPE_SIZE)
8760 	return unsignedp ? unsigned_long_long_accum_type_node
8761 			 : long_long_accum_type_node;
8762     }
8763 
8764   return make_accum_type (size, unsignedp, satp);
8765 }
8766 
8767 /* Create nodes for all integer types (and error_mark_node) using the sizes
8768    of C datatypes.  The caller should call set_sizetype soon after calling
8769    this function to select one of the types as sizetype.  */
8770 
8771 void
8772 build_common_tree_nodes (bool signed_char, bool signed_sizetype)
8773 {
8774   error_mark_node = make_node (ERROR_MARK);
8775   TREE_TYPE (error_mark_node) = error_mark_node;
8776 
8777   initialize_sizetypes (signed_sizetype);
8778 
8779   /* Define both `signed char' and `unsigned char'.  */
8780   signed_char_type_node = make_signed_type (CHAR_TYPE_SIZE);
8781   TYPE_STRING_FLAG (signed_char_type_node) = 1;
8782   unsigned_char_type_node = make_unsigned_type (CHAR_TYPE_SIZE);
8783   TYPE_STRING_FLAG (unsigned_char_type_node) = 1;
8784 
8785   /* Define `char', which is like either `signed char' or `unsigned char'
8786      but not the same as either.  */
8787   char_type_node
8788     = (signed_char
8789        ? make_signed_type (CHAR_TYPE_SIZE)
8790        : make_unsigned_type (CHAR_TYPE_SIZE));
8791   TYPE_STRING_FLAG (char_type_node) = 1;
8792 
8793   short_integer_type_node = make_signed_type (SHORT_TYPE_SIZE);
8794   short_unsigned_type_node = make_unsigned_type (SHORT_TYPE_SIZE);
8795   integer_type_node = make_signed_type (INT_TYPE_SIZE);
8796   unsigned_type_node = make_unsigned_type (INT_TYPE_SIZE);
8797   long_integer_type_node = make_signed_type (LONG_TYPE_SIZE);
8798   long_unsigned_type_node = make_unsigned_type (LONG_TYPE_SIZE);
8799   long_long_integer_type_node = make_signed_type (LONG_LONG_TYPE_SIZE);
8800   long_long_unsigned_type_node = make_unsigned_type (LONG_LONG_TYPE_SIZE);
8801 
8802   /* Define a boolean type.  This type only represents boolean values but
8803      may be larger than char depending on the value of BOOL_TYPE_SIZE.
8804      Front ends which want to override this size (i.e. Java) can redefine
8805      boolean_type_node before calling build_common_tree_nodes_2.  */
8806   boolean_type_node = make_unsigned_type (BOOL_TYPE_SIZE);
8807   TREE_SET_CODE (boolean_type_node, BOOLEAN_TYPE);
8808   TYPE_MAX_VALUE (boolean_type_node) = build_int_cst (boolean_type_node, 1);
8809   TYPE_PRECISION (boolean_type_node) = 1;
8810 
8811   /* Fill in the rest of the sized types.  Reuse existing type nodes
8812      when possible.  */
8813   intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 0);
8814   intHI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (HImode), 0);
8815   intSI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (SImode), 0);
8816   intDI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (DImode), 0);
8817   intTI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (TImode), 0);
8818 
8819   unsigned_intQI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (QImode), 1);
8820   unsigned_intHI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (HImode), 1);
8821   unsigned_intSI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (SImode), 1);
8822   unsigned_intDI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (DImode), 1);
8823   unsigned_intTI_type_node = make_or_reuse_type (GET_MODE_BITSIZE (TImode), 1);
8824 
8825   access_public_node = get_identifier ("public");
8826   access_protected_node = get_identifier ("protected");
8827   access_private_node = get_identifier ("private");
8828 }
8829 
8830 /* Call this function after calling build_common_tree_nodes and set_sizetype.
8831    It will create several other common tree nodes.  */
8832 
8833 void
8834 build_common_tree_nodes_2 (int short_double)
8835 {
8836   /* Define these next since types below may used them.  */
8837   integer_zero_node = build_int_cst (NULL_TREE, 0);
8838   integer_one_node = build_int_cst (NULL_TREE, 1);
8839   integer_minus_one_node = build_int_cst (NULL_TREE, -1);
8840 
8841   size_zero_node = size_int (0);
8842   size_one_node = size_int (1);
8843   bitsize_zero_node = bitsize_int (0);
8844   bitsize_one_node = bitsize_int (1);
8845   bitsize_unit_node = bitsize_int (BITS_PER_UNIT);
8846 
8847   boolean_false_node = TYPE_MIN_VALUE (boolean_type_node);
8848   boolean_true_node = TYPE_MAX_VALUE (boolean_type_node);
8849 
8850   void_type_node = make_node (VOID_TYPE);
8851   layout_type (void_type_node);
8852 
8853   /* We are not going to have real types in C with less than byte alignment,
8854      so we might as well not have any types that claim to have it.  */
8855   TYPE_ALIGN (void_type_node) = BITS_PER_UNIT;
8856   TYPE_USER_ALIGN (void_type_node) = 0;
8857 
8858   null_pointer_node = build_int_cst (build_pointer_type (void_type_node), 0);
8859   layout_type (TREE_TYPE (null_pointer_node));
8860 
8861   ptr_type_node = build_pointer_type (void_type_node);
8862   const_ptr_type_node
8863     = build_pointer_type (build_type_variant (void_type_node, 1, 0));
8864   fileptr_type_node = ptr_type_node;
8865 
8866   float_type_node = make_node (REAL_TYPE);
8867   TYPE_PRECISION (float_type_node) = FLOAT_TYPE_SIZE;
8868   layout_type (float_type_node);
8869 
8870   double_type_node = make_node (REAL_TYPE);
8871   if (short_double)
8872     TYPE_PRECISION (double_type_node) = FLOAT_TYPE_SIZE;
8873   else
8874     TYPE_PRECISION (double_type_node) = DOUBLE_TYPE_SIZE;
8875   layout_type (double_type_node);
8876 
8877   long_double_type_node = make_node (REAL_TYPE);
8878   TYPE_PRECISION (long_double_type_node) = LONG_DOUBLE_TYPE_SIZE;
8879   layout_type (long_double_type_node);
8880 
8881   float_ptr_type_node = build_pointer_type (float_type_node);
8882   double_ptr_type_node = build_pointer_type (double_type_node);
8883   long_double_ptr_type_node = build_pointer_type (long_double_type_node);
8884   integer_ptr_type_node = build_pointer_type (integer_type_node);
8885 
8886   /* Fixed size integer types.  */
8887   uint32_type_node = build_nonstandard_integer_type (32, true);
8888   uint64_type_node = build_nonstandard_integer_type (64, true);
8889 
8890   /* Decimal float types. */
8891   dfloat32_type_node = make_node (REAL_TYPE);
8892   TYPE_PRECISION (dfloat32_type_node) = DECIMAL32_TYPE_SIZE;
8893   layout_type (dfloat32_type_node);
8894   SET_TYPE_MODE (dfloat32_type_node, SDmode);
8895   dfloat32_ptr_type_node = build_pointer_type (dfloat32_type_node);
8896 
8897   dfloat64_type_node = make_node (REAL_TYPE);
8898   TYPE_PRECISION (dfloat64_type_node) = DECIMAL64_TYPE_SIZE;
8899   layout_type (dfloat64_type_node);
8900   SET_TYPE_MODE (dfloat64_type_node, DDmode);
8901   dfloat64_ptr_type_node = build_pointer_type (dfloat64_type_node);
8902 
8903   dfloat128_type_node = make_node (REAL_TYPE);
8904   TYPE_PRECISION (dfloat128_type_node) = DECIMAL128_TYPE_SIZE;
8905   layout_type (dfloat128_type_node);
8906   SET_TYPE_MODE (dfloat128_type_node, TDmode);
8907   dfloat128_ptr_type_node = build_pointer_type (dfloat128_type_node);
8908 
8909   complex_integer_type_node = build_complex_type (integer_type_node);
8910   complex_float_type_node = build_complex_type (float_type_node);
8911   complex_double_type_node = build_complex_type (double_type_node);
8912   complex_long_double_type_node = build_complex_type (long_double_type_node);
8913 
8914 /* Make fixed-point nodes based on sat/non-sat and signed/unsigned.  */
8915 #define MAKE_FIXED_TYPE_NODE(KIND,SIZE) \
8916   sat_ ## KIND ## _type_node = \
8917     make_sat_signed_ ## KIND ## _type (SIZE); \
8918   sat_unsigned_ ## KIND ## _type_node = \
8919     make_sat_unsigned_ ## KIND ## _type (SIZE); \
8920   KIND ## _type_node = make_signed_ ## KIND ## _type (SIZE); \
8921   unsigned_ ## KIND ## _type_node = \
8922     make_unsigned_ ## KIND ## _type (SIZE);
8923 
8924 #define MAKE_FIXED_TYPE_NODE_WIDTH(KIND,WIDTH,SIZE) \
8925   sat_ ## WIDTH ## KIND ## _type_node = \
8926     make_sat_signed_ ## KIND ## _type (SIZE); \
8927   sat_unsigned_ ## WIDTH ## KIND ## _type_node = \
8928     make_sat_unsigned_ ## KIND ## _type (SIZE); \
8929   WIDTH ## KIND ## _type_node = make_signed_ ## KIND ## _type (SIZE); \
8930   unsigned_ ## WIDTH ## KIND ## _type_node = \
8931     make_unsigned_ ## KIND ## _type (SIZE);
8932 
8933 /* Make fixed-point type nodes based on four different widths.  */
8934 #define MAKE_FIXED_TYPE_NODE_FAMILY(N1,N2) \
8935   MAKE_FIXED_TYPE_NODE_WIDTH (N1, short_, SHORT_ ## N2 ## _TYPE_SIZE) \
8936   MAKE_FIXED_TYPE_NODE (N1, N2 ## _TYPE_SIZE) \
8937   MAKE_FIXED_TYPE_NODE_WIDTH (N1, long_, LONG_ ## N2 ## _TYPE_SIZE) \
8938   MAKE_FIXED_TYPE_NODE_WIDTH (N1, long_long_, LONG_LONG_ ## N2 ## _TYPE_SIZE)
8939 
8940 /* Make fixed-point mode nodes based on sat/non-sat and signed/unsigned.  */
8941 #define MAKE_FIXED_MODE_NODE(KIND,NAME,MODE) \
8942   NAME ## _type_node = \
8943     make_or_reuse_signed_ ## KIND ## _type (GET_MODE_BITSIZE (MODE ## mode)); \
8944   u ## NAME ## _type_node = \
8945     make_or_reuse_unsigned_ ## KIND ## _type \
8946       (GET_MODE_BITSIZE (U ## MODE ## mode)); \
8947   sat_ ## NAME ## _type_node = \
8948     make_or_reuse_sat_signed_ ## KIND ## _type \
8949       (GET_MODE_BITSIZE (MODE ## mode)); \
8950   sat_u ## NAME ## _type_node = \
8951     make_or_reuse_sat_unsigned_ ## KIND ## _type \
8952       (GET_MODE_BITSIZE (U ## MODE ## mode));
8953 
8954   /* Fixed-point type and mode nodes.  */
8955   MAKE_FIXED_TYPE_NODE_FAMILY (fract, FRACT)
8956   MAKE_FIXED_TYPE_NODE_FAMILY (accum, ACCUM)
8957   MAKE_FIXED_MODE_NODE (fract, qq, QQ)
8958   MAKE_FIXED_MODE_NODE (fract, hq, HQ)
8959   MAKE_FIXED_MODE_NODE (fract, sq, SQ)
8960   MAKE_FIXED_MODE_NODE (fract, dq, DQ)
8961   MAKE_FIXED_MODE_NODE (fract, tq, TQ)
8962   MAKE_FIXED_MODE_NODE (accum, ha, HA)
8963   MAKE_FIXED_MODE_NODE (accum, sa, SA)
8964   MAKE_FIXED_MODE_NODE (accum, da, DA)
8965   MAKE_FIXED_MODE_NODE (accum, ta, TA)
8966 
8967   {
8968     tree t = targetm.build_builtin_va_list ();
8969 
8970     /* Many back-ends define record types without setting TYPE_NAME.
8971        If we copied the record type here, we'd keep the original
8972        record type without a name.  This breaks name mangling.  So,
8973        don't copy record types and let c_common_nodes_and_builtins()
8974        declare the type to be __builtin_va_list.  */
8975     if (TREE_CODE (t) != RECORD_TYPE)
8976       t = build_variant_type_copy (t);
8977 
8978     va_list_type_node = t;
8979   }
8980 }
8981 
8982 /* A subroutine of build_common_builtin_nodes.  Define a builtin function.  */
8983 
8984 static void
8985 local_define_builtin (const char *name, tree type, enum built_in_function code,
8986                       const char *library_name, int ecf_flags)
8987 {
8988   tree decl;
8989 
8990   decl = add_builtin_function (name, type, code, BUILT_IN_NORMAL,
8991 			       library_name, NULL_TREE);
8992   if (ecf_flags & ECF_CONST)
8993     TREE_READONLY (decl) = 1;
8994   if (ecf_flags & ECF_PURE)
8995     DECL_PURE_P (decl) = 1;
8996   if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
8997     DECL_LOOPING_CONST_OR_PURE_P (decl) = 1;
8998   if (ecf_flags & ECF_NORETURN)
8999     TREE_THIS_VOLATILE (decl) = 1;
9000   if (ecf_flags & ECF_NOTHROW)
9001     TREE_NOTHROW (decl) = 1;
9002   if (ecf_flags & ECF_MALLOC)
9003     DECL_IS_MALLOC (decl) = 1;
9004 
9005   built_in_decls[code] = decl;
9006   implicit_built_in_decls[code] = decl;
9007 }
9008 
9009 /* Call this function after instantiating all builtins that the language
9010    front end cares about.  This will build the rest of the builtins that
9011    are relied upon by the tree optimizers and the middle-end.  */
9012 
9013 void
9014 build_common_builtin_nodes (void)
9015 {
9016   tree tmp, tmp2, ftype;
9017 
9018   if (built_in_decls[BUILT_IN_MEMCPY] == NULL
9019       || built_in_decls[BUILT_IN_MEMMOVE] == NULL)
9020     {
9021       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
9022       tmp = tree_cons (NULL_TREE, const_ptr_type_node, tmp);
9023       tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
9024       ftype = build_function_type (ptr_type_node, tmp);
9025 
9026       if (built_in_decls[BUILT_IN_MEMCPY] == NULL)
9027 	local_define_builtin ("__builtin_memcpy", ftype, BUILT_IN_MEMCPY,
9028 			      "memcpy", ECF_NOTHROW);
9029       if (built_in_decls[BUILT_IN_MEMMOVE] == NULL)
9030 	local_define_builtin ("__builtin_memmove", ftype, BUILT_IN_MEMMOVE,
9031 			      "memmove", ECF_NOTHROW);
9032     }
9033 
9034   if (built_in_decls[BUILT_IN_MEMCMP] == NULL)
9035     {
9036       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
9037       tmp = tree_cons (NULL_TREE, const_ptr_type_node, tmp);
9038       tmp = tree_cons (NULL_TREE, const_ptr_type_node, tmp);
9039       ftype = build_function_type (integer_type_node, tmp);
9040       local_define_builtin ("__builtin_memcmp", ftype, BUILT_IN_MEMCMP,
9041 			    "memcmp", ECF_PURE | ECF_NOTHROW);
9042     }
9043 
9044   if (built_in_decls[BUILT_IN_MEMSET] == NULL)
9045     {
9046       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
9047       tmp = tree_cons (NULL_TREE, integer_type_node, tmp);
9048       tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
9049       ftype = build_function_type (ptr_type_node, tmp);
9050       local_define_builtin ("__builtin_memset", ftype, BUILT_IN_MEMSET,
9051 			    "memset", ECF_NOTHROW);
9052     }
9053 
9054   if (built_in_decls[BUILT_IN_ALLOCA] == NULL)
9055     {
9056       tmp = tree_cons (NULL_TREE, size_type_node, void_list_node);
9057       ftype = build_function_type (ptr_type_node, tmp);
9058       local_define_builtin ("__builtin_alloca", ftype, BUILT_IN_ALLOCA,
9059 			    "alloca",
9060 			    ECF_MALLOC | (flag_stack_check ? 0 : ECF_NOTHROW));
9061     }
9062 
9063   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
9064   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
9065   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
9066   ftype = build_function_type (void_type_node, tmp);
9067   local_define_builtin ("__builtin_init_trampoline", ftype,
9068 			BUILT_IN_INIT_TRAMPOLINE,
9069 			"__builtin_init_trampoline", ECF_NOTHROW);
9070 
9071   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
9072   ftype = build_function_type (ptr_type_node, tmp);
9073   local_define_builtin ("__builtin_adjust_trampoline", ftype,
9074 			BUILT_IN_ADJUST_TRAMPOLINE,
9075 			"__builtin_adjust_trampoline",
9076 			ECF_CONST | ECF_NOTHROW);
9077 
9078   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
9079   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
9080   ftype = build_function_type (void_type_node, tmp);
9081   local_define_builtin ("__builtin_nonlocal_goto", ftype,
9082 			BUILT_IN_NONLOCAL_GOTO,
9083 			"__builtin_nonlocal_goto",
9084 			ECF_NORETURN | ECF_NOTHROW);
9085 
9086   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
9087   tmp = tree_cons (NULL_TREE, ptr_type_node, tmp);
9088   ftype = build_function_type (void_type_node, tmp);
9089   local_define_builtin ("__builtin_setjmp_setup", ftype,
9090 			BUILT_IN_SETJMP_SETUP,
9091 			"__builtin_setjmp_setup", ECF_NOTHROW);
9092 
9093   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
9094   ftype = build_function_type (ptr_type_node, tmp);
9095   local_define_builtin ("__builtin_setjmp_dispatcher", ftype,
9096 			BUILT_IN_SETJMP_DISPATCHER,
9097 			"__builtin_setjmp_dispatcher",
9098 			ECF_PURE | ECF_NOTHROW);
9099 
9100   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
9101   ftype = build_function_type (void_type_node, tmp);
9102   local_define_builtin ("__builtin_setjmp_receiver", ftype,
9103 			BUILT_IN_SETJMP_RECEIVER,
9104 			"__builtin_setjmp_receiver", ECF_NOTHROW);
9105 
9106   ftype = build_function_type (ptr_type_node, void_list_node);
9107   local_define_builtin ("__builtin_stack_save", ftype, BUILT_IN_STACK_SAVE,
9108 			"__builtin_stack_save", ECF_NOTHROW);
9109 
9110   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
9111   ftype = build_function_type (void_type_node, tmp);
9112   local_define_builtin ("__builtin_stack_restore", ftype,
9113 			BUILT_IN_STACK_RESTORE,
9114 			"__builtin_stack_restore", ECF_NOTHROW);
9115 
9116   ftype = build_function_type (void_type_node, void_list_node);
9117   local_define_builtin ("__builtin_profile_func_enter", ftype,
9118 			BUILT_IN_PROFILE_FUNC_ENTER, "profile_func_enter", 0);
9119   local_define_builtin ("__builtin_profile_func_exit", ftype,
9120 			BUILT_IN_PROFILE_FUNC_EXIT, "profile_func_exit", 0);
9121 
9122   /* If there's a possibility that we might use the ARM EABI, build the
9123     alternate __cxa_end_cleanup node used to resume from C++ and Java.  */
9124   if (targetm.arm_eabi_unwinder)
9125     {
9126       ftype = build_function_type (void_type_node, void_list_node);
9127       local_define_builtin ("__builtin_cxa_end_cleanup", ftype,
9128 			    BUILT_IN_CXA_END_CLEANUP,
9129 			    "__cxa_end_cleanup", ECF_NORETURN);
9130     }
9131 
9132   tmp = tree_cons (NULL_TREE, ptr_type_node, void_list_node);
9133   ftype = build_function_type (void_type_node, tmp);
9134   local_define_builtin ("__builtin_unwind_resume", ftype,
9135 			BUILT_IN_UNWIND_RESUME,
9136 			(USING_SJLJ_EXCEPTIONS
9137 			 ? "_Unwind_SjLj_Resume" : "_Unwind_Resume"),
9138 			ECF_NORETURN);
9139 
9140   /* The exception object and filter values from the runtime.  The argument
9141      must be zero before exception lowering, i.e. from the front end.  After
9142      exception lowering, it will be the region number for the exception
9143      landing pad.  These functions are PURE instead of CONST to prevent
9144      them from being hoisted past the exception edge that will initialize
9145      its value in the landing pad.  */
9146   tmp = tree_cons (NULL_TREE, integer_type_node, void_list_node);
9147   ftype = build_function_type (ptr_type_node, tmp);
9148   local_define_builtin ("__builtin_eh_pointer", ftype, BUILT_IN_EH_POINTER,
9149 			"__builtin_eh_pointer", ECF_PURE | ECF_NOTHROW);
9150 
9151   tmp2 = lang_hooks.types.type_for_mode (targetm.eh_return_filter_mode (), 0);
9152   ftype = build_function_type (tmp2, tmp);
9153   local_define_builtin ("__builtin_eh_filter", ftype, BUILT_IN_EH_FILTER,
9154 			"__builtin_eh_filter", ECF_PURE | ECF_NOTHROW);
9155 
9156   tmp = tree_cons (NULL_TREE, integer_type_node, void_list_node);
9157   tmp = tree_cons (NULL_TREE, integer_type_node, tmp);
9158   ftype = build_function_type (void_type_node, tmp);
9159   local_define_builtin ("__builtin_eh_copy_values", ftype,
9160 			BUILT_IN_EH_COPY_VALUES,
9161 			"__builtin_eh_copy_values", ECF_NOTHROW);
9162 
9163   /* Complex multiplication and division.  These are handled as builtins
9164      rather than optabs because emit_library_call_value doesn't support
9165      complex.  Further, we can do slightly better with folding these
9166      beasties if the real and complex parts of the arguments are separate.  */
9167   {
9168     int mode;
9169 
9170     for (mode = MIN_MODE_COMPLEX_FLOAT; mode <= MAX_MODE_COMPLEX_FLOAT; ++mode)
9171       {
9172 	char mode_name_buf[4], *q;
9173 	const char *p;
9174 	enum built_in_function mcode, dcode;
9175 	tree type, inner_type;
9176 
9177 	type = lang_hooks.types.type_for_mode ((enum machine_mode) mode, 0);
9178 	if (type == NULL)
9179 	  continue;
9180 	inner_type = TREE_TYPE (type);
9181 
9182 	tmp = tree_cons (NULL_TREE, inner_type, void_list_node);
9183 	tmp = tree_cons (NULL_TREE, inner_type, tmp);
9184 	tmp = tree_cons (NULL_TREE, inner_type, tmp);
9185 	tmp = tree_cons (NULL_TREE, inner_type, tmp);
9186 	ftype = build_function_type (type, tmp);
9187 
9188         mcode = ((enum built_in_function)
9189 		 (BUILT_IN_COMPLEX_MUL_MIN + mode - MIN_MODE_COMPLEX_FLOAT));
9190         dcode = ((enum built_in_function)
9191 		 (BUILT_IN_COMPLEX_DIV_MIN + mode - MIN_MODE_COMPLEX_FLOAT));
9192 
9193         for (p = GET_MODE_NAME (mode), q = mode_name_buf; *p; p++, q++)
9194 	  *q = TOLOWER (*p);
9195 	*q = '\0';
9196 
9197 	built_in_names[mcode] = concat ("__mul", mode_name_buf, "3", NULL);
9198         local_define_builtin (built_in_names[mcode], ftype, mcode,
9199 			      built_in_names[mcode], ECF_CONST | ECF_NOTHROW);
9200 
9201 	built_in_names[dcode] = concat ("__div", mode_name_buf, "3", NULL);
9202         local_define_builtin (built_in_names[dcode], ftype, dcode,
9203 			      built_in_names[dcode], ECF_CONST | ECF_NOTHROW);
9204       }
9205   }
9206 }
9207 
9208 /* HACK.  GROSS.  This is absolutely disgusting.  I wish there was a
9209    better way.
9210 
9211    If we requested a pointer to a vector, build up the pointers that
9212    we stripped off while looking for the inner type.  Similarly for
9213    return values from functions.
9214 
9215    The argument TYPE is the top of the chain, and BOTTOM is the
9216    new type which we will point to.  */
9217 
9218 tree
9219 reconstruct_complex_type (tree type, tree bottom)
9220 {
9221   tree inner, outer;
9222 
9223   if (TREE_CODE (type) == POINTER_TYPE)
9224     {
9225       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9226       outer = build_pointer_type_for_mode (inner, TYPE_MODE (type),
9227 					   TYPE_REF_CAN_ALIAS_ALL (type));
9228     }
9229   else if (TREE_CODE (type) == REFERENCE_TYPE)
9230     {
9231       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9232       outer = build_reference_type_for_mode (inner, TYPE_MODE (type),
9233 					     TYPE_REF_CAN_ALIAS_ALL (type));
9234     }
9235   else if (TREE_CODE (type) == ARRAY_TYPE)
9236     {
9237       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9238       outer = build_array_type (inner, TYPE_DOMAIN (type));
9239     }
9240   else if (TREE_CODE (type) == FUNCTION_TYPE)
9241     {
9242       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9243       outer = build_function_type (inner, TYPE_ARG_TYPES (type));
9244     }
9245   else if (TREE_CODE (type) == METHOD_TYPE)
9246     {
9247       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9248       /* The build_method_type_directly() routine prepends 'this' to argument list,
9249          so we must compensate by getting rid of it.  */
9250       outer
9251 	= build_method_type_directly
9252 	    (TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (type))),
9253 	     inner,
9254 	     TREE_CHAIN (TYPE_ARG_TYPES (type)));
9255     }
9256   else if (TREE_CODE (type) == OFFSET_TYPE)
9257     {
9258       inner = reconstruct_complex_type (TREE_TYPE (type), bottom);
9259       outer = build_offset_type (TYPE_OFFSET_BASETYPE (type), inner);
9260     }
9261   else
9262     return bottom;
9263 
9264   return build_type_attribute_qual_variant (outer, TYPE_ATTRIBUTES (type),
9265 					    TYPE_QUALS (type));
9266 }
9267 
9268 /* Returns a vector tree node given a mode (integer, vector, or BLKmode) and
9269    the inner type.  */
9270 tree
9271 build_vector_type_for_mode (tree innertype, enum machine_mode mode)
9272 {
9273   int nunits;
9274 
9275   switch (GET_MODE_CLASS (mode))
9276     {
9277     case MODE_VECTOR_INT:
9278     case MODE_VECTOR_FLOAT:
9279     case MODE_VECTOR_FRACT:
9280     case MODE_VECTOR_UFRACT:
9281     case MODE_VECTOR_ACCUM:
9282     case MODE_VECTOR_UACCUM:
9283       nunits = GET_MODE_NUNITS (mode);
9284       break;
9285 
9286     case MODE_INT:
9287       /* Check that there are no leftover bits.  */
9288       gcc_assert (GET_MODE_BITSIZE (mode)
9289 		  % TREE_INT_CST_LOW (TYPE_SIZE (innertype)) == 0);
9290 
9291       nunits = GET_MODE_BITSIZE (mode)
9292 	       / TREE_INT_CST_LOW (TYPE_SIZE (innertype));
9293       break;
9294 
9295     default:
9296       gcc_unreachable ();
9297     }
9298 
9299   return make_vector_type (innertype, nunits, mode);
9300 }
9301 
9302 /* Similarly, but takes the inner type and number of units, which must be
9303    a power of two.  */
9304 
9305 tree
9306 build_vector_type (tree innertype, int nunits)
9307 {
9308   return make_vector_type (innertype, nunits, VOIDmode);
9309 }
9310 
9311 /* Similarly, but takes the inner type and number of units, which must be
9312    a power of two.  */
9313 
9314 tree
9315 build_opaque_vector_type (tree innertype, int nunits)
9316 {
9317   tree t;
9318   innertype = build_distinct_type_copy (innertype);
9319   t = make_vector_type (innertype, nunits, VOIDmode);
9320   TYPE_VECTOR_OPAQUE (t) = true;
9321   return t;
9322 }
9323 
9324 
9325 /* Given an initializer INIT, return TRUE if INIT is zero or some
9326    aggregate of zeros.  Otherwise return FALSE.  */
9327 bool
9328 initializer_zerop (const_tree init)
9329 {
9330   tree elt;
9331 
9332   STRIP_NOPS (init);
9333 
9334   switch (TREE_CODE (init))
9335     {
9336     case INTEGER_CST:
9337       return integer_zerop (init);
9338 
9339     case REAL_CST:
9340       /* ??? Note that this is not correct for C4X float formats.  There,
9341 	 a bit pattern of all zeros is 1.0; 0.0 is encoded with the most
9342 	 negative exponent.  */
9343       return real_zerop (init)
9344 	&& ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (init));
9345 
9346     case FIXED_CST:
9347       return fixed_zerop (init);
9348 
9349     case COMPLEX_CST:
9350       return integer_zerop (init)
9351 	|| (real_zerop (init)
9352 	    && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (TREE_REALPART (init)))
9353 	    && ! REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (TREE_IMAGPART (init))));
9354 
9355     case VECTOR_CST:
9356       for (elt = TREE_VECTOR_CST_ELTS (init); elt; elt = TREE_CHAIN (elt))
9357 	if (!initializer_zerop (TREE_VALUE (elt)))
9358 	  return false;
9359       return true;
9360 
9361     case CONSTRUCTOR:
9362       {
9363 	unsigned HOST_WIDE_INT idx;
9364 
9365 	FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (init), idx, elt)
9366 	  if (!initializer_zerop (elt))
9367 	    return false;
9368 	return true;
9369       }
9370 
9371     default:
9372       return false;
9373     }
9374 }
9375 
9376 /* Build an empty statement at location LOC.  */
9377 
9378 tree
9379 build_empty_stmt (location_t loc)
9380 {
9381   tree t = build1 (NOP_EXPR, void_type_node, size_zero_node);
9382   SET_EXPR_LOCATION (t, loc);
9383   return t;
9384 }
9385 
9386 
9387 /* Build an OpenMP clause with code CODE.  LOC is the location of the
9388    clause.  */
9389 
9390 tree
9391 build_omp_clause (location_t loc, enum omp_clause_code code)
9392 {
9393   tree t;
9394   int size, length;
9395 
9396   length = omp_clause_num_ops[code];
9397   size = (sizeof (struct tree_omp_clause) + (length - 1) * sizeof (tree));
9398 
9399   t = GGC_NEWVAR (union tree_node, size);
9400   memset (t, 0, size);
9401   TREE_SET_CODE (t, OMP_CLAUSE);
9402   OMP_CLAUSE_SET_CODE (t, code);
9403   OMP_CLAUSE_LOCATION (t) = loc;
9404 
9405 #ifdef GATHER_STATISTICS
9406   tree_node_counts[(int) omp_clause_kind]++;
9407   tree_node_sizes[(int) omp_clause_kind] += size;
9408 #endif
9409 
9410   return t;
9411 }
9412 
9413 /* Build a tcc_vl_exp object with code CODE and room for LEN operands.  LEN
9414    includes the implicit operand count in TREE_OPERAND 0, and so must be >= 1.
9415    Except for the CODE and operand count field, other storage for the
9416    object is initialized to zeros.  */
9417 
9418 tree
9419 build_vl_exp_stat (enum tree_code code, int len MEM_STAT_DECL)
9420 {
9421   tree t;
9422   int length = (len - 1) * sizeof (tree) + sizeof (struct tree_exp);
9423 
9424   gcc_assert (TREE_CODE_CLASS (code) == tcc_vl_exp);
9425   gcc_assert (len >= 1);
9426 
9427 #ifdef GATHER_STATISTICS
9428   tree_node_counts[(int) e_kind]++;
9429   tree_node_sizes[(int) e_kind] += length;
9430 #endif
9431 
9432   t = (tree) ggc_alloc_zone_pass_stat (length, &tree_zone);
9433 
9434   memset (t, 0, length);
9435 
9436   TREE_SET_CODE (t, code);
9437 
9438   /* Can't use TREE_OPERAND to store the length because if checking is
9439      enabled, it will try to check the length before we store it.  :-P  */
9440   t->exp.operands[0] = build_int_cst (sizetype, len);
9441 
9442   return t;
9443 }
9444 
9445 
9446 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE
9447    and FN and a null static chain slot.  ARGLIST is a TREE_LIST of the
9448    arguments.  */
9449 
9450 tree
9451 build_call_list (tree return_type, tree fn, tree arglist)
9452 {
9453   tree t;
9454   int i;
9455 
9456   t = build_vl_exp (CALL_EXPR, list_length (arglist) + 3);
9457   TREE_TYPE (t) = return_type;
9458   CALL_EXPR_FN (t) = fn;
9459   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
9460   for (i = 0; arglist; arglist = TREE_CHAIN (arglist), i++)
9461     CALL_EXPR_ARG (t, i) = TREE_VALUE (arglist);
9462   process_call_operands (t);
9463   return t;
9464 }
9465 
9466 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
9467    FN and a null static chain slot.  NARGS is the number of call arguments
9468    which are specified as "..." arguments.  */
9469 
9470 tree
9471 build_call_nary (tree return_type, tree fn, int nargs, ...)
9472 {
9473   tree ret;
9474   va_list args;
9475   va_start (args, nargs);
9476   ret = build_call_valist (return_type, fn, nargs, args);
9477   va_end (args);
9478   return ret;
9479 }
9480 
9481 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
9482    FN and a null static chain slot.  NARGS is the number of call arguments
9483    which are specified as a va_list ARGS.  */
9484 
9485 tree
9486 build_call_valist (tree return_type, tree fn, int nargs, va_list args)
9487 {
9488   tree t;
9489   int i;
9490 
9491   t = build_vl_exp (CALL_EXPR, nargs + 3);
9492   TREE_TYPE (t) = return_type;
9493   CALL_EXPR_FN (t) = fn;
9494   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
9495   for (i = 0; i < nargs; i++)
9496     CALL_EXPR_ARG (t, i) = va_arg (args, tree);
9497   process_call_operands (t);
9498   return t;
9499 }
9500 
9501 /* Build a CALL_EXPR of class tcc_vl_exp with the indicated RETURN_TYPE and
9502    FN and a null static chain slot.  NARGS is the number of call arguments
9503    which are specified as a tree array ARGS.  */
9504 
9505 tree
9506 build_call_array_loc (location_t loc, tree return_type, tree fn,
9507 		      int nargs, const tree *args)
9508 {
9509   tree t;
9510   int i;
9511 
9512   t = build_vl_exp (CALL_EXPR, nargs + 3);
9513   TREE_TYPE (t) = return_type;
9514   CALL_EXPR_FN (t) = fn;
9515   CALL_EXPR_STATIC_CHAIN (t) = NULL_TREE;
9516   for (i = 0; i < nargs; i++)
9517     CALL_EXPR_ARG (t, i) = args[i];
9518   process_call_operands (t);
9519   SET_EXPR_LOCATION (t, loc);
9520   return t;
9521 }
9522 
9523 /* Like build_call_array, but takes a VEC.  */
9524 
9525 tree
9526 build_call_vec (tree return_type, tree fn, VEC(tree,gc) *args)
9527 {
9528   tree ret, t;
9529   unsigned int ix;
9530 
9531   ret = build_vl_exp (CALL_EXPR, VEC_length (tree, args) + 3);
9532   TREE_TYPE (ret) = return_type;
9533   CALL_EXPR_FN (ret) = fn;
9534   CALL_EXPR_STATIC_CHAIN (ret) = NULL_TREE;
9535   for (ix = 0; VEC_iterate (tree, args, ix, t); ++ix)
9536     CALL_EXPR_ARG (ret, ix) = t;
9537   process_call_operands (ret);
9538   return ret;
9539 }
9540 
9541 
9542 /* Returns true if it is possible to prove that the index of
9543    an array access REF (an ARRAY_REF expression) falls into the
9544    array bounds.  */
9545 
9546 bool
9547 in_array_bounds_p (tree ref)
9548 {
9549   tree idx = TREE_OPERAND (ref, 1);
9550   tree min, max;
9551 
9552   if (TREE_CODE (idx) != INTEGER_CST)
9553     return false;
9554 
9555   min = array_ref_low_bound (ref);
9556   max = array_ref_up_bound (ref);
9557   if (!min
9558       || !max
9559       || TREE_CODE (min) != INTEGER_CST
9560       || TREE_CODE (max) != INTEGER_CST)
9561     return false;
9562 
9563   if (tree_int_cst_lt (idx, min)
9564       || tree_int_cst_lt (max, idx))
9565     return false;
9566 
9567   return true;
9568 }
9569 
9570 /* Returns true if it is possible to prove that the range of
9571    an array access REF (an ARRAY_RANGE_REF expression) falls
9572    into the array bounds.  */
9573 
9574 bool
9575 range_in_array_bounds_p (tree ref)
9576 {
9577   tree domain_type = TYPE_DOMAIN (TREE_TYPE (ref));
9578   tree range_min, range_max, min, max;
9579 
9580   range_min = TYPE_MIN_VALUE (domain_type);
9581   range_max = TYPE_MAX_VALUE (domain_type);
9582   if (!range_min
9583       || !range_max
9584       || TREE_CODE (range_min) != INTEGER_CST
9585       || TREE_CODE (range_max) != INTEGER_CST)
9586     return false;
9587 
9588   min = array_ref_low_bound (ref);
9589   max = array_ref_up_bound (ref);
9590   if (!min
9591       || !max
9592       || TREE_CODE (min) != INTEGER_CST
9593       || TREE_CODE (max) != INTEGER_CST)
9594     return false;
9595 
9596   if (tree_int_cst_lt (range_min, min)
9597       || tree_int_cst_lt (max, range_max))
9598     return false;
9599 
9600   return true;
9601 }
9602 
9603 /* Return true if T (assumed to be a DECL) must be assigned a memory
9604    location.  */
9605 
9606 bool
9607 needs_to_live_in_memory (const_tree t)
9608 {
9609   if (TREE_CODE (t) == SSA_NAME)
9610     t = SSA_NAME_VAR (t);
9611 
9612   return (TREE_ADDRESSABLE (t)
9613 	  || is_global_var (t)
9614 	  || (TREE_CODE (t) == RESULT_DECL
9615 	      && aggregate_value_p (t, current_function_decl)));
9616 }
9617 
9618 /* There are situations in which a language considers record types
9619    compatible which have different field lists.  Decide if two fields
9620    are compatible.  It is assumed that the parent records are compatible.  */
9621 
9622 bool
9623 fields_compatible_p (const_tree f1, const_tree f2)
9624 {
9625   if (!operand_equal_p (DECL_FIELD_BIT_OFFSET (f1),
9626 			DECL_FIELD_BIT_OFFSET (f2), OEP_ONLY_CONST))
9627     return false;
9628 
9629   if (!operand_equal_p (DECL_FIELD_OFFSET (f1),
9630                         DECL_FIELD_OFFSET (f2), OEP_ONLY_CONST))
9631     return false;
9632 
9633   if (!types_compatible_p (TREE_TYPE (f1), TREE_TYPE (f2)))
9634     return false;
9635 
9636   return true;
9637 }
9638 
9639 /* Locate within RECORD a field that is compatible with ORIG_FIELD.  */
9640 
9641 tree
9642 find_compatible_field (tree record, tree orig_field)
9643 {
9644   tree f;
9645 
9646   for (f = TYPE_FIELDS (record); f ; f = TREE_CHAIN (f))
9647     if (TREE_CODE (f) == FIELD_DECL
9648 	&& fields_compatible_p (f, orig_field))
9649       return f;
9650 
9651   /* ??? Why isn't this on the main fields list?  */
9652   f = TYPE_VFIELD (record);
9653   if (f && TREE_CODE (f) == FIELD_DECL
9654       && fields_compatible_p (f, orig_field))
9655     return f;
9656 
9657   /* ??? We should abort here, but Java appears to do Bad Things
9658      with inherited fields.  */
9659   return orig_field;
9660 }
9661 
9662 /* Return value of a constant X and sign-extend it.  */
9663 
9664 HOST_WIDE_INT
9665 int_cst_value (const_tree x)
9666 {
9667   unsigned bits = TYPE_PRECISION (TREE_TYPE (x));
9668   unsigned HOST_WIDE_INT val = TREE_INT_CST_LOW (x);
9669 
9670   /* Make sure the sign-extended value will fit in a HOST_WIDE_INT.  */
9671   gcc_assert (TREE_INT_CST_HIGH (x) == 0
9672 	      || TREE_INT_CST_HIGH (x) == -1);
9673 
9674   if (bits < HOST_BITS_PER_WIDE_INT)
9675     {
9676       bool negative = ((val >> (bits - 1)) & 1) != 0;
9677       if (negative)
9678 	val |= (~(unsigned HOST_WIDE_INT) 0) << (bits - 1) << 1;
9679       else
9680 	val &= ~((~(unsigned HOST_WIDE_INT) 0) << (bits - 1) << 1);
9681     }
9682 
9683   return val;
9684 }
9685 
9686 /* Return value of a constant X and sign-extend it.  */
9687 
9688 HOST_WIDEST_INT
9689 widest_int_cst_value (const_tree x)
9690 {
9691   unsigned bits = TYPE_PRECISION (TREE_TYPE (x));
9692   unsigned HOST_WIDEST_INT val = TREE_INT_CST_LOW (x);
9693 
9694 #if HOST_BITS_PER_WIDEST_INT > HOST_BITS_PER_WIDE_INT
9695   gcc_assert (HOST_BITS_PER_WIDEST_INT >= 2 * HOST_BITS_PER_WIDE_INT);
9696   val |= (((unsigned HOST_WIDEST_INT) TREE_INT_CST_HIGH (x))
9697 	  << HOST_BITS_PER_WIDE_INT);
9698 #else
9699   /* Make sure the sign-extended value will fit in a HOST_WIDE_INT.  */
9700   gcc_assert (TREE_INT_CST_HIGH (x) == 0
9701 	      || TREE_INT_CST_HIGH (x) == -1);
9702 #endif
9703 
9704   if (bits < HOST_BITS_PER_WIDEST_INT)
9705     {
9706       bool negative = ((val >> (bits - 1)) & 1) != 0;
9707       if (negative)
9708 	val |= (~(unsigned HOST_WIDEST_INT) 0) << (bits - 1) << 1;
9709       else
9710 	val &= ~((~(unsigned HOST_WIDEST_INT) 0) << (bits - 1) << 1);
9711     }
9712 
9713   return val;
9714 }
9715 
9716 /* If TYPE is an integral type, return an equivalent type which is
9717     unsigned iff UNSIGNEDP is true.  If TYPE is not an integral type,
9718     return TYPE itself.  */
9719 
9720 tree
9721 signed_or_unsigned_type_for (int unsignedp, tree type)
9722 {
9723   tree t = type;
9724   if (POINTER_TYPE_P (type))
9725     {
9726       /* If the pointer points to the normal address space, use the
9727 	 size_type_node.  Otherwise use an appropriate size for the pointer
9728 	 based on the named address space it points to.  */
9729       if (!TYPE_ADDR_SPACE (TREE_TYPE (t)))
9730 	t = size_type_node;
9731       else
9732 	return lang_hooks.types.type_for_size (TYPE_PRECISION (t), unsignedp);
9733     }
9734 
9735   if (!INTEGRAL_TYPE_P (t) || TYPE_UNSIGNED (t) == unsignedp)
9736     return t;
9737 
9738   return lang_hooks.types.type_for_size (TYPE_PRECISION (t), unsignedp);
9739 }
9740 
9741 /* Returns unsigned variant of TYPE.  */
9742 
9743 tree
9744 unsigned_type_for (tree type)
9745 {
9746   return signed_or_unsigned_type_for (1, type);
9747 }
9748 
9749 /* Returns signed variant of TYPE.  */
9750 
9751 tree
9752 signed_type_for (tree type)
9753 {
9754   return signed_or_unsigned_type_for (0, type);
9755 }
9756 
9757 /* Returns the largest value obtainable by casting something in INNER type to
9758    OUTER type.  */
9759 
9760 tree
9761 upper_bound_in_type (tree outer, tree inner)
9762 {
9763   unsigned HOST_WIDE_INT lo, hi;
9764   unsigned int det = 0;
9765   unsigned oprec = TYPE_PRECISION (outer);
9766   unsigned iprec = TYPE_PRECISION (inner);
9767   unsigned prec;
9768 
9769   /* Compute a unique number for every combination.  */
9770   det |= (oprec > iprec) ? 4 : 0;
9771   det |= TYPE_UNSIGNED (outer) ? 2 : 0;
9772   det |= TYPE_UNSIGNED (inner) ? 1 : 0;
9773 
9774   /* Determine the exponent to use.  */
9775   switch (det)
9776     {
9777     case 0:
9778     case 1:
9779       /* oprec <= iprec, outer: signed, inner: don't care.  */
9780       prec = oprec - 1;
9781       break;
9782     case 2:
9783     case 3:
9784       /* oprec <= iprec, outer: unsigned, inner: don't care.  */
9785       prec = oprec;
9786       break;
9787     case 4:
9788       /* oprec > iprec, outer: signed, inner: signed.  */
9789       prec = iprec - 1;
9790       break;
9791     case 5:
9792       /* oprec > iprec, outer: signed, inner: unsigned.  */
9793       prec = iprec;
9794       break;
9795     case 6:
9796       /* oprec > iprec, outer: unsigned, inner: signed.  */
9797       prec = oprec;
9798       break;
9799     case 7:
9800       /* oprec > iprec, outer: unsigned, inner: unsigned.  */
9801       prec = iprec;
9802       break;
9803     default:
9804       gcc_unreachable ();
9805     }
9806 
9807   /* Compute 2^^prec - 1.  */
9808   if (prec <= HOST_BITS_PER_WIDE_INT)
9809     {
9810       hi = 0;
9811       lo = ((~(unsigned HOST_WIDE_INT) 0)
9812 	    >> (HOST_BITS_PER_WIDE_INT - prec));
9813     }
9814   else
9815     {
9816       hi = ((~(unsigned HOST_WIDE_INT) 0)
9817 	    >> (2 * HOST_BITS_PER_WIDE_INT - prec));
9818       lo = ~(unsigned HOST_WIDE_INT) 0;
9819     }
9820 
9821   return build_int_cst_wide (outer, lo, hi);
9822 }
9823 
9824 /* Returns the smallest value obtainable by casting something in INNER type to
9825    OUTER type.  */
9826 
9827 tree
9828 lower_bound_in_type (tree outer, tree inner)
9829 {
9830   unsigned HOST_WIDE_INT lo, hi;
9831   unsigned oprec = TYPE_PRECISION (outer);
9832   unsigned iprec = TYPE_PRECISION (inner);
9833 
9834   /* If OUTER type is unsigned, we can definitely cast 0 to OUTER type
9835      and obtain 0.  */
9836   if (TYPE_UNSIGNED (outer)
9837       /* If we are widening something of an unsigned type, OUTER type
9838 	 contains all values of INNER type.  In particular, both INNER
9839 	 and OUTER types have zero in common.  */
9840       || (oprec > iprec && TYPE_UNSIGNED (inner)))
9841     lo = hi = 0;
9842   else
9843     {
9844       /* If we are widening a signed type to another signed type, we
9845 	 want to obtain -2^^(iprec-1).  If we are keeping the
9846 	 precision or narrowing to a signed type, we want to obtain
9847 	 -2^(oprec-1).  */
9848       unsigned prec = oprec > iprec ? iprec : oprec;
9849 
9850       if (prec <= HOST_BITS_PER_WIDE_INT)
9851 	{
9852 	  hi = ~(unsigned HOST_WIDE_INT) 0;
9853 	  lo = (~(unsigned HOST_WIDE_INT) 0) << (prec - 1);
9854 	}
9855       else
9856 	{
9857 	  hi = ((~(unsigned HOST_WIDE_INT) 0)
9858 		<< (prec - HOST_BITS_PER_WIDE_INT - 1));
9859 	  lo = 0;
9860 	}
9861     }
9862 
9863   return build_int_cst_wide (outer, lo, hi);
9864 }
9865 
9866 /* Return nonzero if two operands that are suitable for PHI nodes are
9867    necessarily equal.  Specifically, both ARG0 and ARG1 must be either
9868    SSA_NAME or invariant.  Note that this is strictly an optimization.
9869    That is, callers of this function can directly call operand_equal_p
9870    and get the same result, only slower.  */
9871 
9872 int
9873 operand_equal_for_phi_arg_p (const_tree arg0, const_tree arg1)
9874 {
9875   if (arg0 == arg1)
9876     return 1;
9877   if (TREE_CODE (arg0) == SSA_NAME || TREE_CODE (arg1) == SSA_NAME)
9878     return 0;
9879   return operand_equal_p (arg0, arg1, 0);
9880 }
9881 
9882 /* Returns number of zeros at the end of binary representation of X.
9883 
9884    ??? Use ffs if available?  */
9885 
9886 tree
9887 num_ending_zeros (const_tree x)
9888 {
9889   unsigned HOST_WIDE_INT fr, nfr;
9890   unsigned num, abits;
9891   tree type = TREE_TYPE (x);
9892 
9893   if (TREE_INT_CST_LOW (x) == 0)
9894     {
9895       num = HOST_BITS_PER_WIDE_INT;
9896       fr = TREE_INT_CST_HIGH (x);
9897     }
9898   else
9899     {
9900       num = 0;
9901       fr = TREE_INT_CST_LOW (x);
9902     }
9903 
9904   for (abits = HOST_BITS_PER_WIDE_INT / 2; abits; abits /= 2)
9905     {
9906       nfr = fr >> abits;
9907       if (nfr << abits == fr)
9908 	{
9909 	  num += abits;
9910 	  fr = nfr;
9911 	}
9912     }
9913 
9914   if (num > TYPE_PRECISION (type))
9915     num = TYPE_PRECISION (type);
9916 
9917   return build_int_cst_type (type, num);
9918 }
9919 
9920 
9921 #define WALK_SUBTREE(NODE)				\
9922   do							\
9923     {							\
9924       result = walk_tree_1 (&(NODE), func, data, pset, lh);	\
9925       if (result)					\
9926 	return result;					\
9927     }							\
9928   while (0)
9929 
9930 /* This is a subroutine of walk_tree that walks field of TYPE that are to
9931    be walked whenever a type is seen in the tree.  Rest of operands and return
9932    value are as for walk_tree.  */
9933 
9934 static tree
9935 walk_type_fields (tree type, walk_tree_fn func, void *data,
9936 		  struct pointer_set_t *pset, walk_tree_lh lh)
9937 {
9938   tree result = NULL_TREE;
9939 
9940   switch (TREE_CODE (type))
9941     {
9942     case POINTER_TYPE:
9943     case REFERENCE_TYPE:
9944       /* We have to worry about mutually recursive pointers.  These can't
9945 	 be written in C.  They can in Ada.  It's pathological, but
9946 	 there's an ACATS test (c38102a) that checks it.  Deal with this
9947 	 by checking if we're pointing to another pointer, that one
9948 	 points to another pointer, that one does too, and we have no htab.
9949 	 If so, get a hash table.  We check three levels deep to avoid
9950 	 the cost of the hash table if we don't need one.  */
9951       if (POINTER_TYPE_P (TREE_TYPE (type))
9952 	  && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (type)))
9953 	  && POINTER_TYPE_P (TREE_TYPE (TREE_TYPE (TREE_TYPE (type))))
9954 	  && !pset)
9955 	{
9956 	  result = walk_tree_without_duplicates (&TREE_TYPE (type),
9957 						 func, data);
9958 	  if (result)
9959 	    return result;
9960 
9961 	  break;
9962 	}
9963 
9964       /* ... fall through ... */
9965 
9966     case COMPLEX_TYPE:
9967       WALK_SUBTREE (TREE_TYPE (type));
9968       break;
9969 
9970     case METHOD_TYPE:
9971       WALK_SUBTREE (TYPE_METHOD_BASETYPE (type));
9972 
9973       /* Fall through.  */
9974 
9975     case FUNCTION_TYPE:
9976       WALK_SUBTREE (TREE_TYPE (type));
9977       {
9978 	tree arg;
9979 
9980 	/* We never want to walk into default arguments.  */
9981 	for (arg = TYPE_ARG_TYPES (type); arg; arg = TREE_CHAIN (arg))
9982 	  WALK_SUBTREE (TREE_VALUE (arg));
9983       }
9984       break;
9985 
9986     case ARRAY_TYPE:
9987       /* Don't follow this nodes's type if a pointer for fear that
9988 	 we'll have infinite recursion.  If we have a PSET, then we
9989 	 need not fear.  */
9990       if (pset
9991 	  || (!POINTER_TYPE_P (TREE_TYPE (type))
9992 	      && TREE_CODE (TREE_TYPE (type)) != OFFSET_TYPE))
9993 	WALK_SUBTREE (TREE_TYPE (type));
9994       WALK_SUBTREE (TYPE_DOMAIN (type));
9995       break;
9996 
9997     case OFFSET_TYPE:
9998       WALK_SUBTREE (TREE_TYPE (type));
9999       WALK_SUBTREE (TYPE_OFFSET_BASETYPE (type));
10000       break;
10001 
10002     default:
10003       break;
10004     }
10005 
10006   return NULL_TREE;
10007 }
10008 
10009 /* Apply FUNC to all the sub-trees of TP in a pre-order traversal.  FUNC is
10010    called with the DATA and the address of each sub-tree.  If FUNC returns a
10011    non-NULL value, the traversal is stopped, and the value returned by FUNC
10012    is returned.  If PSET is non-NULL it is used to record the nodes visited,
10013    and to avoid visiting a node more than once.  */
10014 
10015 tree
10016 walk_tree_1 (tree *tp, walk_tree_fn func, void *data,
10017 	     struct pointer_set_t *pset, walk_tree_lh lh)
10018 {
10019   enum tree_code code;
10020   int walk_subtrees;
10021   tree result;
10022 
10023 #define WALK_SUBTREE_TAIL(NODE)				\
10024   do							\
10025     {							\
10026        tp = & (NODE);					\
10027        goto tail_recurse;				\
10028     }							\
10029   while (0)
10030 
10031  tail_recurse:
10032   /* Skip empty subtrees.  */
10033   if (!*tp)
10034     return NULL_TREE;
10035 
10036   /* Don't walk the same tree twice, if the user has requested
10037      that we avoid doing so.  */
10038   if (pset && pointer_set_insert (pset, *tp))
10039     return NULL_TREE;
10040 
10041   /* Call the function.  */
10042   walk_subtrees = 1;
10043   result = (*func) (tp, &walk_subtrees, data);
10044 
10045   /* If we found something, return it.  */
10046   if (result)
10047     return result;
10048 
10049   code = TREE_CODE (*tp);
10050 
10051   /* Even if we didn't, FUNC may have decided that there was nothing
10052      interesting below this point in the tree.  */
10053   if (!walk_subtrees)
10054     {
10055       /* But we still need to check our siblings.  */
10056       if (code == TREE_LIST)
10057 	WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
10058       else if (code == OMP_CLAUSE)
10059 	WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10060       else
10061 	return NULL_TREE;
10062     }
10063 
10064   if (lh)
10065     {
10066       result = (*lh) (tp, &walk_subtrees, func, data, pset);
10067       if (result || !walk_subtrees)
10068         return result;
10069     }
10070 
10071   switch (code)
10072     {
10073     case ERROR_MARK:
10074     case IDENTIFIER_NODE:
10075     case INTEGER_CST:
10076     case REAL_CST:
10077     case FIXED_CST:
10078     case VECTOR_CST:
10079     case STRING_CST:
10080     case BLOCK:
10081     case PLACEHOLDER_EXPR:
10082     case SSA_NAME:
10083     case FIELD_DECL:
10084     case RESULT_DECL:
10085       /* None of these have subtrees other than those already walked
10086 	 above.  */
10087       break;
10088 
10089     case TREE_LIST:
10090       WALK_SUBTREE (TREE_VALUE (*tp));
10091       WALK_SUBTREE_TAIL (TREE_CHAIN (*tp));
10092       break;
10093 
10094     case TREE_VEC:
10095       {
10096 	int len = TREE_VEC_LENGTH (*tp);
10097 
10098 	if (len == 0)
10099 	  break;
10100 
10101 	/* Walk all elements but the first.  */
10102 	while (--len)
10103 	  WALK_SUBTREE (TREE_VEC_ELT (*tp, len));
10104 
10105 	/* Now walk the first one as a tail call.  */
10106 	WALK_SUBTREE_TAIL (TREE_VEC_ELT (*tp, 0));
10107       }
10108 
10109     case COMPLEX_CST:
10110       WALK_SUBTREE (TREE_REALPART (*tp));
10111       WALK_SUBTREE_TAIL (TREE_IMAGPART (*tp));
10112 
10113     case CONSTRUCTOR:
10114       {
10115 	unsigned HOST_WIDE_INT idx;
10116 	constructor_elt *ce;
10117 
10118 	for (idx = 0;
10119 	     VEC_iterate(constructor_elt, CONSTRUCTOR_ELTS (*tp), idx, ce);
10120 	     idx++)
10121 	  WALK_SUBTREE (ce->value);
10122       }
10123       break;
10124 
10125     case SAVE_EXPR:
10126       WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, 0));
10127 
10128     case BIND_EXPR:
10129       {
10130 	tree decl;
10131 	for (decl = BIND_EXPR_VARS (*tp); decl; decl = TREE_CHAIN (decl))
10132 	  {
10133 	    /* Walk the DECL_INITIAL and DECL_SIZE.  We don't want to walk
10134 	       into declarations that are just mentioned, rather than
10135 	       declared; they don't really belong to this part of the tree.
10136 	       And, we can see cycles: the initializer for a declaration
10137 	       can refer to the declaration itself.  */
10138 	    WALK_SUBTREE (DECL_INITIAL (decl));
10139 	    WALK_SUBTREE (DECL_SIZE (decl));
10140 	    WALK_SUBTREE (DECL_SIZE_UNIT (decl));
10141 	  }
10142 	WALK_SUBTREE_TAIL (BIND_EXPR_BODY (*tp));
10143       }
10144 
10145     case STATEMENT_LIST:
10146       {
10147 	tree_stmt_iterator i;
10148 	for (i = tsi_start (*tp); !tsi_end_p (i); tsi_next (&i))
10149 	  WALK_SUBTREE (*tsi_stmt_ptr (i));
10150       }
10151       break;
10152 
10153     case OMP_CLAUSE:
10154       switch (OMP_CLAUSE_CODE (*tp))
10155 	{
10156 	case OMP_CLAUSE_PRIVATE:
10157 	case OMP_CLAUSE_SHARED:
10158 	case OMP_CLAUSE_FIRSTPRIVATE:
10159 	case OMP_CLAUSE_COPYIN:
10160 	case OMP_CLAUSE_COPYPRIVATE:
10161 	case OMP_CLAUSE_IF:
10162 	case OMP_CLAUSE_NUM_THREADS:
10163 	case OMP_CLAUSE_SCHEDULE:
10164 	  WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, 0));
10165 	  /* FALLTHRU */
10166 
10167 	case OMP_CLAUSE_NOWAIT:
10168 	case OMP_CLAUSE_ORDERED:
10169 	case OMP_CLAUSE_DEFAULT:
10170 	case OMP_CLAUSE_UNTIED:
10171 	  WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10172 
10173 	case OMP_CLAUSE_LASTPRIVATE:
10174 	  WALK_SUBTREE (OMP_CLAUSE_DECL (*tp));
10175 	  WALK_SUBTREE (OMP_CLAUSE_LASTPRIVATE_STMT (*tp));
10176 	  WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10177 
10178 	case OMP_CLAUSE_COLLAPSE:
10179 	  {
10180 	    int i;
10181 	    for (i = 0; i < 3; i++)
10182 	      WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, i));
10183 	    WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10184 	  }
10185 
10186 	case OMP_CLAUSE_REDUCTION:
10187 	  {
10188 	    int i;
10189 	    for (i = 0; i < 4; i++)
10190 	      WALK_SUBTREE (OMP_CLAUSE_OPERAND (*tp, i));
10191 	    WALK_SUBTREE_TAIL (OMP_CLAUSE_CHAIN (*tp));
10192 	  }
10193 
10194 	default:
10195 	  gcc_unreachable ();
10196 	}
10197       break;
10198 
10199     case TARGET_EXPR:
10200       {
10201 	int i, len;
10202 
10203 	/* TARGET_EXPRs are peculiar: operands 1 and 3 can be the same.
10204 	   But, we only want to walk once.  */
10205 	len = (TREE_OPERAND (*tp, 3) == TREE_OPERAND (*tp, 1)) ? 2 : 3;
10206 	for (i = 0; i < len; ++i)
10207 	  WALK_SUBTREE (TREE_OPERAND (*tp, i));
10208 	WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, len));
10209       }
10210 
10211     case DECL_EXPR:
10212       /* If this is a TYPE_DECL, walk into the fields of the type that it's
10213 	 defining.  We only want to walk into these fields of a type in this
10214 	 case and not in the general case of a mere reference to the type.
10215 
10216 	 The criterion is as follows: if the field can be an expression, it
10217 	 must be walked only here.  This should be in keeping with the fields
10218 	 that are directly gimplified in gimplify_type_sizes in order for the
10219 	 mark/copy-if-shared/unmark machinery of the gimplifier to work with
10220 	 variable-sized types.
10221 
10222 	 Note that DECLs get walked as part of processing the BIND_EXPR.  */
10223       if (TREE_CODE (DECL_EXPR_DECL (*tp)) == TYPE_DECL)
10224 	{
10225 	  tree *type_p = &TREE_TYPE (DECL_EXPR_DECL (*tp));
10226 	  if (TREE_CODE (*type_p) == ERROR_MARK)
10227 	    return NULL_TREE;
10228 
10229 	  /* Call the function for the type.  See if it returns anything or
10230 	     doesn't want us to continue.  If we are to continue, walk both
10231 	     the normal fields and those for the declaration case.  */
10232 	  result = (*func) (type_p, &walk_subtrees, data);
10233 	  if (result || !walk_subtrees)
10234 	    return result;
10235 
10236 	  result = walk_type_fields (*type_p, func, data, pset, lh);
10237 	  if (result)
10238 	    return result;
10239 
10240 	  /* If this is a record type, also walk the fields.  */
10241 	  if (RECORD_OR_UNION_TYPE_P (*type_p))
10242 	    {
10243 	      tree field;
10244 
10245 	      for (field = TYPE_FIELDS (*type_p); field;
10246 		   field = TREE_CHAIN (field))
10247 		{
10248 		  /* We'd like to look at the type of the field, but we can
10249 		     easily get infinite recursion.  So assume it's pointed
10250 		     to elsewhere in the tree.  Also, ignore things that
10251 		     aren't fields.  */
10252 		  if (TREE_CODE (field) != FIELD_DECL)
10253 		    continue;
10254 
10255 		  WALK_SUBTREE (DECL_FIELD_OFFSET (field));
10256 		  WALK_SUBTREE (DECL_SIZE (field));
10257 		  WALK_SUBTREE (DECL_SIZE_UNIT (field));
10258 		  if (TREE_CODE (*type_p) == QUAL_UNION_TYPE)
10259 		    WALK_SUBTREE (DECL_QUALIFIER (field));
10260 		}
10261 	    }
10262 
10263 	  /* Same for scalar types.  */
10264 	  else if (TREE_CODE (*type_p) == BOOLEAN_TYPE
10265 		   || TREE_CODE (*type_p) == ENUMERAL_TYPE
10266 		   || TREE_CODE (*type_p) == INTEGER_TYPE
10267 		   || TREE_CODE (*type_p) == FIXED_POINT_TYPE
10268 		   || TREE_CODE (*type_p) == REAL_TYPE)
10269 	    {
10270 	      WALK_SUBTREE (TYPE_MIN_VALUE (*type_p));
10271 	      WALK_SUBTREE (TYPE_MAX_VALUE (*type_p));
10272 	    }
10273 
10274 	  WALK_SUBTREE (TYPE_SIZE (*type_p));
10275 	  WALK_SUBTREE_TAIL (TYPE_SIZE_UNIT (*type_p));
10276 	}
10277       /* FALLTHRU */
10278 
10279     default:
10280       if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
10281 	{
10282 	  int i, len;
10283 
10284 	  /* Walk over all the sub-trees of this operand.  */
10285 	  len = TREE_OPERAND_LENGTH (*tp);
10286 
10287 	  /* Go through the subtrees.  We need to do this in forward order so
10288 	     that the scope of a FOR_EXPR is handled properly.  */
10289 	  if (len)
10290 	    {
10291 	      for (i = 0; i < len - 1; ++i)
10292 		WALK_SUBTREE (TREE_OPERAND (*tp, i));
10293 	      WALK_SUBTREE_TAIL (TREE_OPERAND (*tp, len - 1));
10294 	    }
10295 	}
10296       /* If this is a type, walk the needed fields in the type.  */
10297       else if (TYPE_P (*tp))
10298 	return walk_type_fields (*tp, func, data, pset, lh);
10299       break;
10300     }
10301 
10302   /* We didn't find what we were looking for.  */
10303   return NULL_TREE;
10304 
10305 #undef WALK_SUBTREE_TAIL
10306 }
10307 #undef WALK_SUBTREE
10308 
10309 /* Like walk_tree, but does not walk duplicate nodes more than once.  */
10310 
10311 tree
10312 walk_tree_without_duplicates_1 (tree *tp, walk_tree_fn func, void *data,
10313 				walk_tree_lh lh)
10314 {
10315   tree result;
10316   struct pointer_set_t *pset;
10317 
10318   pset = pointer_set_create ();
10319   result = walk_tree_1 (tp, func, data, pset, lh);
10320   pointer_set_destroy (pset);
10321   return result;
10322 }
10323 
10324 
10325 tree *
10326 tree_block (tree t)
10327 {
10328   char const c = TREE_CODE_CLASS (TREE_CODE (t));
10329 
10330   if (IS_EXPR_CODE_CLASS (c))
10331     return &t->exp.block;
10332   gcc_unreachable ();
10333   return NULL;
10334 }
10335 
10336 /* Build and return a TREE_LIST of arguments in the CALL_EXPR exp.
10337    FIXME: don't use this function.  It exists for compatibility with
10338    the old representation of CALL_EXPRs where a list was used to hold the
10339    arguments.  Places that currently extract the arglist from a CALL_EXPR
10340    ought to be rewritten to use the CALL_EXPR itself.  */
10341 tree
10342 call_expr_arglist (tree exp)
10343 {
10344   tree arglist = NULL_TREE;
10345   int i;
10346   for (i = call_expr_nargs (exp) - 1; i >= 0; i--)
10347     arglist = tree_cons (NULL_TREE, CALL_EXPR_ARG (exp, i), arglist);
10348   return arglist;
10349 }
10350 
10351 
10352 /* Create a nameless artificial label and put it in the current
10353    function context.  The label has a location of LOC.  Returns the
10354    newly created label.  */
10355 
10356 tree
10357 create_artificial_label (location_t loc)
10358 {
10359   tree lab = build_decl (loc,
10360       			 LABEL_DECL, NULL_TREE, void_type_node);
10361 
10362   DECL_ARTIFICIAL (lab) = 1;
10363   DECL_IGNORED_P (lab) = 1;
10364   DECL_CONTEXT (lab) = current_function_decl;
10365   return lab;
10366 }
10367 
10368 /*  Given a tree, try to return a useful variable name that we can use
10369     to prefix a temporary that is being assigned the value of the tree.
10370     I.E. given  <temp> = &A, return A.  */
10371 
10372 const char *
10373 get_name (tree t)
10374 {
10375   tree stripped_decl;
10376 
10377   stripped_decl = t;
10378   STRIP_NOPS (stripped_decl);
10379   if (DECL_P (stripped_decl) && DECL_NAME (stripped_decl))
10380     return IDENTIFIER_POINTER (DECL_NAME (stripped_decl));
10381   else
10382     {
10383       switch (TREE_CODE (stripped_decl))
10384 	{
10385 	case ADDR_EXPR:
10386 	  return get_name (TREE_OPERAND (stripped_decl, 0));
10387 	default:
10388 	  return NULL;
10389 	}
10390     }
10391 }
10392 
10393 /* Return true if TYPE has a variable argument list.  */
10394 
10395 bool
10396 stdarg_p (tree fntype)
10397 {
10398   function_args_iterator args_iter;
10399   tree n = NULL_TREE, t;
10400 
10401   if (!fntype)
10402     return false;
10403 
10404   FOREACH_FUNCTION_ARGS(fntype, t, args_iter)
10405     {
10406       n = t;
10407     }
10408 
10409   return n != NULL_TREE && n != void_type_node;
10410 }
10411 
10412 /* Return true if TYPE has a prototype.  */
10413 
10414 bool
10415 prototype_p (tree fntype)
10416 {
10417   tree t;
10418 
10419   gcc_assert (fntype != NULL_TREE);
10420 
10421   t = TYPE_ARG_TYPES (fntype);
10422   return (t != NULL_TREE);
10423 }
10424 
10425 /* If BLOCK is inlined from an __attribute__((__artificial__))
10426    routine, return pointer to location from where it has been
10427    called.  */
10428 location_t *
10429 block_nonartificial_location (tree block)
10430 {
10431   location_t *ret = NULL;
10432 
10433   while (block && TREE_CODE (block) == BLOCK
10434 	 && BLOCK_ABSTRACT_ORIGIN (block))
10435     {
10436       tree ao = BLOCK_ABSTRACT_ORIGIN (block);
10437 
10438       while (TREE_CODE (ao) == BLOCK
10439 	     && BLOCK_ABSTRACT_ORIGIN (ao)
10440 	     && BLOCK_ABSTRACT_ORIGIN (ao) != ao)
10441 	ao = BLOCK_ABSTRACT_ORIGIN (ao);
10442 
10443       if (TREE_CODE (ao) == FUNCTION_DECL)
10444 	{
10445 	  /* If AO is an artificial inline, point RET to the
10446 	     call site locus at which it has been inlined and continue
10447 	     the loop, in case AO's caller is also an artificial
10448 	     inline.  */
10449 	  if (DECL_DECLARED_INLINE_P (ao)
10450 	      && lookup_attribute ("artificial", DECL_ATTRIBUTES (ao)))
10451 	    ret = &BLOCK_SOURCE_LOCATION (block);
10452 	  else
10453 	    break;
10454 	}
10455       else if (TREE_CODE (ao) != BLOCK)
10456 	break;
10457 
10458       block = BLOCK_SUPERCONTEXT (block);
10459     }
10460   return ret;
10461 }
10462 
10463 
10464 /* If EXP is inlined from an __attribute__((__artificial__))
10465    function, return the location of the original call expression.  */
10466 
10467 location_t
10468 tree_nonartificial_location (tree exp)
10469 {
10470   location_t *loc = block_nonartificial_location (TREE_BLOCK (exp));
10471 
10472   if (loc)
10473     return *loc;
10474   else
10475     return EXPR_LOCATION (exp);
10476 }
10477 
10478 
10479 /* These are the hash table functions for the hash table of OPTIMIZATION_NODEq
10480    nodes.  */
10481 
10482 /* Return the hash code code X, an OPTIMIZATION_NODE or TARGET_OPTION code.  */
10483 
10484 static hashval_t
10485 cl_option_hash_hash (const void *x)
10486 {
10487   const_tree const t = (const_tree) x;
10488   const char *p;
10489   size_t i;
10490   size_t len = 0;
10491   hashval_t hash = 0;
10492 
10493   if (TREE_CODE (t) == OPTIMIZATION_NODE)
10494     {
10495       p = (const char *)TREE_OPTIMIZATION (t);
10496       len = sizeof (struct cl_optimization);
10497     }
10498 
10499   else if (TREE_CODE (t) == TARGET_OPTION_NODE)
10500     {
10501       p = (const char *)TREE_TARGET_OPTION (t);
10502       len = sizeof (struct cl_target_option);
10503     }
10504 
10505   else
10506     gcc_unreachable ();
10507 
10508   /* assume most opt flags are just 0/1, some are 2-3, and a few might be
10509      something else.  */
10510   for (i = 0; i < len; i++)
10511     if (p[i])
10512       hash = (hash << 4) ^ ((i << 2) | p[i]);
10513 
10514   return hash;
10515 }
10516 
10517 /* Return nonzero if the value represented by *X (an OPTIMIZATION or
10518    TARGET_OPTION tree node) is the same as that given by *Y, which is the
10519    same.  */
10520 
10521 static int
10522 cl_option_hash_eq (const void *x, const void *y)
10523 {
10524   const_tree const xt = (const_tree) x;
10525   const_tree const yt = (const_tree) y;
10526   const char *xp;
10527   const char *yp;
10528   size_t len;
10529 
10530   if (TREE_CODE (xt) != TREE_CODE (yt))
10531     return 0;
10532 
10533   if (TREE_CODE (xt) == OPTIMIZATION_NODE)
10534     {
10535       xp = (const char *)TREE_OPTIMIZATION (xt);
10536       yp = (const char *)TREE_OPTIMIZATION (yt);
10537       len = sizeof (struct cl_optimization);
10538     }
10539 
10540   else if (TREE_CODE (xt) == TARGET_OPTION_NODE)
10541     {
10542       xp = (const char *)TREE_TARGET_OPTION (xt);
10543       yp = (const char *)TREE_TARGET_OPTION (yt);
10544       len = sizeof (struct cl_target_option);
10545     }
10546 
10547   else
10548     gcc_unreachable ();
10549 
10550   return (memcmp (xp, yp, len) == 0);
10551 }
10552 
10553 /* Build an OPTIMIZATION_NODE based on the current options.  */
10554 
10555 tree
10556 build_optimization_node (void)
10557 {
10558   tree t;
10559   void **slot;
10560 
10561   /* Use the cache of optimization nodes.  */
10562 
10563   cl_optimization_save (TREE_OPTIMIZATION (cl_optimization_node));
10564 
10565   slot = htab_find_slot (cl_option_hash_table, cl_optimization_node, INSERT);
10566   t = (tree) *slot;
10567   if (!t)
10568     {
10569       /* Insert this one into the hash table.  */
10570       t = cl_optimization_node;
10571       *slot = t;
10572 
10573       /* Make a new node for next time round.  */
10574       cl_optimization_node = make_node (OPTIMIZATION_NODE);
10575     }
10576 
10577   return t;
10578 }
10579 
10580 /* Build a TARGET_OPTION_NODE based on the current options.  */
10581 
10582 tree
10583 build_target_option_node (void)
10584 {
10585   tree t;
10586   void **slot;
10587 
10588   /* Use the cache of optimization nodes.  */
10589 
10590   cl_target_option_save (TREE_TARGET_OPTION (cl_target_option_node));
10591 
10592   slot = htab_find_slot (cl_option_hash_table, cl_target_option_node, INSERT);
10593   t = (tree) *slot;
10594   if (!t)
10595     {
10596       /* Insert this one into the hash table.  */
10597       t = cl_target_option_node;
10598       *slot = t;
10599 
10600       /* Make a new node for next time round.  */
10601       cl_target_option_node = make_node (TARGET_OPTION_NODE);
10602     }
10603 
10604   return t;
10605 }
10606 
10607 /* Determine the "ultimate origin" of a block.  The block may be an inlined
10608    instance of an inlined instance of a block which is local to an inline
10609    function, so we have to trace all of the way back through the origin chain
10610    to find out what sort of node actually served as the original seed for the
10611    given block.  */
10612 
10613 tree
10614 block_ultimate_origin (const_tree block)
10615 {
10616   tree immediate_origin = BLOCK_ABSTRACT_ORIGIN (block);
10617 
10618   /* output_inline_function sets BLOCK_ABSTRACT_ORIGIN for all the
10619      nodes in the function to point to themselves; ignore that if
10620      we're trying to output the abstract instance of this function.  */
10621   if (BLOCK_ABSTRACT (block) && immediate_origin == block)
10622     return NULL_TREE;
10623 
10624   if (immediate_origin == NULL_TREE)
10625     return NULL_TREE;
10626   else
10627     {
10628       tree ret_val;
10629       tree lookahead = immediate_origin;
10630 
10631       do
10632 	{
10633 	  ret_val = lookahead;
10634 	  lookahead = (TREE_CODE (ret_val) == BLOCK
10635 		       ? BLOCK_ABSTRACT_ORIGIN (ret_val) : NULL);
10636 	}
10637       while (lookahead != NULL && lookahead != ret_val);
10638 
10639       /* The block's abstract origin chain may not be the *ultimate* origin of
10640 	 the block. It could lead to a DECL that has an abstract origin set.
10641 	 If so, we want that DECL's abstract origin (which is what DECL_ORIGIN
10642 	 will give us if it has one).  Note that DECL's abstract origins are
10643 	 supposed to be the most distant ancestor (or so decl_ultimate_origin
10644 	 claims), so we don't need to loop following the DECL origins.  */
10645       if (DECL_P (ret_val))
10646 	return DECL_ORIGIN (ret_val);
10647 
10648       return ret_val;
10649     }
10650 }
10651 
10652 /* Return true if T1 and T2 are equivalent lists.  */
10653 
10654 bool
10655 list_equal_p (const_tree t1, const_tree t2)
10656 {
10657   for (; t1 && t2; t1 = TREE_CHAIN (t1) , t2 = TREE_CHAIN (t2))
10658     if (TREE_VALUE (t1) != TREE_VALUE (t2))
10659       return false;
10660   return !t1 && !t2;
10661 }
10662 
10663 /* Return true iff conversion in EXP generates no instruction.  Mark
10664    it inline so that we fully inline into the stripping functions even
10665    though we have two uses of this function.  */
10666 
10667 static inline bool
10668 tree_nop_conversion (const_tree exp)
10669 {
10670   tree outer_type, inner_type;
10671 
10672   if (!CONVERT_EXPR_P (exp)
10673       && TREE_CODE (exp) != NON_LVALUE_EXPR)
10674     return false;
10675   if (TREE_OPERAND (exp, 0) == error_mark_node)
10676     return false;
10677 
10678   outer_type = TREE_TYPE (exp);
10679   inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));
10680 
10681   /* Use precision rather then machine mode when we can, which gives
10682      the correct answer even for submode (bit-field) types.  */
10683   if ((INTEGRAL_TYPE_P (outer_type)
10684        || POINTER_TYPE_P (outer_type)
10685        || TREE_CODE (outer_type) == OFFSET_TYPE)
10686       && (INTEGRAL_TYPE_P (inner_type)
10687 	  || POINTER_TYPE_P (inner_type)
10688 	  || TREE_CODE (inner_type) == OFFSET_TYPE))
10689     return TYPE_PRECISION (outer_type) == TYPE_PRECISION (inner_type);
10690 
10691   /* Otherwise fall back on comparing machine modes (e.g. for
10692      aggregate types, floats).  */
10693   return TYPE_MODE (outer_type) == TYPE_MODE (inner_type);
10694 }
10695 
10696 /* Return true iff conversion in EXP generates no instruction.  Don't
10697    consider conversions changing the signedness.  */
10698 
10699 static bool
10700 tree_sign_nop_conversion (const_tree exp)
10701 {
10702   tree outer_type, inner_type;
10703 
10704   if (!tree_nop_conversion (exp))
10705     return false;
10706 
10707   outer_type = TREE_TYPE (exp);
10708   inner_type = TREE_TYPE (TREE_OPERAND (exp, 0));
10709 
10710   return (TYPE_UNSIGNED (outer_type) == TYPE_UNSIGNED (inner_type)
10711 	  && POINTER_TYPE_P (outer_type) == POINTER_TYPE_P (inner_type));
10712 }
10713 
10714 /* Strip conversions from EXP according to tree_nop_conversion and
10715    return the resulting expression.  */
10716 
10717 tree
10718 tree_strip_nop_conversions (tree exp)
10719 {
10720   while (tree_nop_conversion (exp))
10721     exp = TREE_OPERAND (exp, 0);
10722   return exp;
10723 }
10724 
10725 /* Strip conversions from EXP according to tree_sign_nop_conversion
10726    and return the resulting expression.  */
10727 
10728 tree
10729 tree_strip_sign_nop_conversions (tree exp)
10730 {
10731   while (tree_sign_nop_conversion (exp))
10732     exp = TREE_OPERAND (exp, 0);
10733   return exp;
10734 }
10735 
10736 static GTY(()) tree gcc_eh_personality_decl;
10737 
10738 /* Return the GCC personality function decl.  */
10739 
10740 tree
10741 lhd_gcc_personality (void)
10742 {
10743   if (!gcc_eh_personality_decl)
10744     gcc_eh_personality_decl
10745       = build_personality_function (USING_SJLJ_EXCEPTIONS
10746 				    ? "__gcc_personality_sj0"
10747 				    : "__gcc_personality_v0");
10748 
10749   return gcc_eh_personality_decl;
10750 }
10751 
10752 #include "gt-tree.h"
10753