1 /* Gimple decl, type, and expression support functions.
2
3 Copyright (C) 2007-2022 Free Software Foundation, Inc.
4 Contributed by Aldy Hernandez <aldyh@redhat.com>
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 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "backend.h"
26 #include "tree.h"
27 #include "gimple.h"
28 #include "stringpool.h"
29 #include "gimple-ssa.h"
30 #include "fold-const.h"
31 #include "tree-eh.h"
32 #include "gimplify.h"
33 #include "stor-layout.h"
34 #include "demangle.h"
35 #include "hash-set.h"
36 #include "rtl.h"
37 #include "tree-pass.h"
38 #include "stringpool.h"
39 #include "attribs.h"
40 #include "target.h"
41
42 /* ----- Type related ----- */
43
44 /* Return true if the conversion from INNER_TYPE to OUTER_TYPE is a
45 useless type conversion, otherwise return false.
46
47 This function implicitly defines the middle-end type system. With
48 the notion of 'a < b' meaning that useless_type_conversion_p (a, b)
49 holds and 'a > b' meaning that useless_type_conversion_p (b, a) holds,
50 the following invariants shall be fulfilled:
51
52 1) useless_type_conversion_p is transitive.
53 If a < b and b < c then a < c.
54
55 2) useless_type_conversion_p is not symmetric.
56 From a < b does not follow a > b.
57
58 3) Types define the available set of operations applicable to values.
59 A type conversion is useless if the operations for the target type
60 is a subset of the operations for the source type. For example
61 casts to void* are useless, casts from void* are not (void* can't
62 be dereferenced or offsetted, but copied, hence its set of operations
63 is a strict subset of that of all other data pointer types). Casts
64 to const T* are useless (can't be written to), casts from const T*
65 to T* are not. */
66
67 bool
useless_type_conversion_p(tree outer_type,tree inner_type)68 useless_type_conversion_p (tree outer_type, tree inner_type)
69 {
70 /* Do the following before stripping toplevel qualifiers. */
71 if (POINTER_TYPE_P (inner_type)
72 && POINTER_TYPE_P (outer_type))
73 {
74 /* Do not lose casts between pointers to different address spaces. */
75 if (TYPE_ADDR_SPACE (TREE_TYPE (outer_type))
76 != TYPE_ADDR_SPACE (TREE_TYPE (inner_type)))
77 return false;
78 /* Do not lose casts to function pointer types. */
79 if ((TREE_CODE (TREE_TYPE (outer_type)) == FUNCTION_TYPE
80 || TREE_CODE (TREE_TYPE (outer_type)) == METHOD_TYPE)
81 && !(TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE
82 || TREE_CODE (TREE_TYPE (inner_type)) == METHOD_TYPE))
83 return false;
84 }
85
86 /* From now on qualifiers on value types do not matter. */
87 inner_type = TYPE_MAIN_VARIANT (inner_type);
88 outer_type = TYPE_MAIN_VARIANT (outer_type);
89
90 if (inner_type == outer_type)
91 return true;
92
93 /* Changes in machine mode are never useless conversions because the RTL
94 middle-end expects explicit conversions between modes. */
95 if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type))
96 return false;
97
98 /* If both the inner and outer types are integral types, then the
99 conversion is not necessary if they have the same mode and
100 signedness and precision, and both or neither are boolean. */
101 if (INTEGRAL_TYPE_P (inner_type)
102 && INTEGRAL_TYPE_P (outer_type))
103 {
104 /* Preserve changes in signedness or precision. */
105 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
106 || TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
107 return false;
108
109 /* Preserve conversions to/from BOOLEAN_TYPE if types are not
110 of precision one. */
111 if (((TREE_CODE (inner_type) == BOOLEAN_TYPE)
112 != (TREE_CODE (outer_type) == BOOLEAN_TYPE))
113 && TYPE_PRECISION (outer_type) != 1)
114 return false;
115
116 /* We don't need to preserve changes in the types minimum or
117 maximum value in general as these do not generate code
118 unless the types precisions are different. */
119 return true;
120 }
121
122 /* Scalar floating point types with the same mode are compatible. */
123 else if (SCALAR_FLOAT_TYPE_P (inner_type)
124 && SCALAR_FLOAT_TYPE_P (outer_type))
125 return true;
126
127 /* Fixed point types with the same mode are compatible. */
128 else if (FIXED_POINT_TYPE_P (inner_type)
129 && FIXED_POINT_TYPE_P (outer_type))
130 return TYPE_SATURATING (inner_type) == TYPE_SATURATING (outer_type);
131
132 /* We need to take special care recursing to pointed-to types. */
133 else if (POINTER_TYPE_P (inner_type)
134 && POINTER_TYPE_P (outer_type))
135 {
136 /* We do not care for const qualification of the pointed-to types
137 as const qualification has no semantic value to the middle-end. */
138
139 /* Otherwise pointers/references are equivalent. */
140 return true;
141 }
142
143 /* Recurse for complex types. */
144 else if (TREE_CODE (inner_type) == COMPLEX_TYPE
145 && TREE_CODE (outer_type) == COMPLEX_TYPE)
146 return useless_type_conversion_p (TREE_TYPE (outer_type),
147 TREE_TYPE (inner_type));
148
149 /* Recurse for vector types with the same number of subparts. */
150 else if (TREE_CODE (inner_type) == VECTOR_TYPE
151 && TREE_CODE (outer_type) == VECTOR_TYPE)
152 return (known_eq (TYPE_VECTOR_SUBPARTS (inner_type),
153 TYPE_VECTOR_SUBPARTS (outer_type))
154 && useless_type_conversion_p (TREE_TYPE (outer_type),
155 TREE_TYPE (inner_type))
156 && targetm.compatible_vector_types_p (inner_type, outer_type));
157
158 else if (TREE_CODE (inner_type) == ARRAY_TYPE
159 && TREE_CODE (outer_type) == ARRAY_TYPE)
160 {
161 /* Preserve various attributes. */
162 if (TYPE_REVERSE_STORAGE_ORDER (inner_type)
163 != TYPE_REVERSE_STORAGE_ORDER (outer_type))
164 return false;
165 if (TYPE_STRING_FLAG (inner_type) != TYPE_STRING_FLAG (outer_type))
166 return false;
167
168 /* Conversions from array types with unknown extent to
169 array types with known extent are not useless. */
170 if (!TYPE_DOMAIN (inner_type) && TYPE_DOMAIN (outer_type))
171 return false;
172
173 /* Nor are conversions from array types with non-constant size to
174 array types with constant size or to different size. */
175 if (TYPE_SIZE (outer_type)
176 && TREE_CODE (TYPE_SIZE (outer_type)) == INTEGER_CST
177 && (!TYPE_SIZE (inner_type)
178 || TREE_CODE (TYPE_SIZE (inner_type)) != INTEGER_CST
179 || !tree_int_cst_equal (TYPE_SIZE (outer_type),
180 TYPE_SIZE (inner_type))))
181 return false;
182
183 /* Check conversions between arrays with partially known extents.
184 If the array min/max values are constant they have to match.
185 Otherwise allow conversions to unknown and variable extents.
186 In particular this declares conversions that may change the
187 mode to BLKmode as useless. */
188 if (TYPE_DOMAIN (inner_type)
189 && TYPE_DOMAIN (outer_type)
190 && TYPE_DOMAIN (inner_type) != TYPE_DOMAIN (outer_type))
191 {
192 tree inner_min = TYPE_MIN_VALUE (TYPE_DOMAIN (inner_type));
193 tree outer_min = TYPE_MIN_VALUE (TYPE_DOMAIN (outer_type));
194 tree inner_max = TYPE_MAX_VALUE (TYPE_DOMAIN (inner_type));
195 tree outer_max = TYPE_MAX_VALUE (TYPE_DOMAIN (outer_type));
196
197 /* After gimplification a variable min/max value carries no
198 additional information compared to a NULL value. All that
199 matters has been lowered to be part of the IL. */
200 if (inner_min && TREE_CODE (inner_min) != INTEGER_CST)
201 inner_min = NULL_TREE;
202 if (outer_min && TREE_CODE (outer_min) != INTEGER_CST)
203 outer_min = NULL_TREE;
204 if (inner_max && TREE_CODE (inner_max) != INTEGER_CST)
205 inner_max = NULL_TREE;
206 if (outer_max && TREE_CODE (outer_max) != INTEGER_CST)
207 outer_max = NULL_TREE;
208
209 /* Conversions NULL / variable <- cst are useless, but not
210 the other way around. */
211 if (outer_min
212 && (!inner_min
213 || !tree_int_cst_equal (inner_min, outer_min)))
214 return false;
215 if (outer_max
216 && (!inner_max
217 || !tree_int_cst_equal (inner_max, outer_max)))
218 return false;
219 }
220
221 /* Recurse on the element check. */
222 return useless_type_conversion_p (TREE_TYPE (outer_type),
223 TREE_TYPE (inner_type));
224 }
225
226 else if ((TREE_CODE (inner_type) == FUNCTION_TYPE
227 || TREE_CODE (inner_type) == METHOD_TYPE)
228 && TREE_CODE (inner_type) == TREE_CODE (outer_type))
229 {
230 tree outer_parm, inner_parm;
231
232 /* If the return types are not compatible bail out. */
233 if (!useless_type_conversion_p (TREE_TYPE (outer_type),
234 TREE_TYPE (inner_type)))
235 return false;
236
237 /* Method types should belong to a compatible base class. */
238 if (TREE_CODE (inner_type) == METHOD_TYPE
239 && !useless_type_conversion_p (TYPE_METHOD_BASETYPE (outer_type),
240 TYPE_METHOD_BASETYPE (inner_type)))
241 return false;
242
243 /* A conversion to an unprototyped argument list is ok. */
244 if (!prototype_p (outer_type))
245 return true;
246
247 /* If the unqualified argument types are compatible the conversion
248 is useless. */
249 if (TYPE_ARG_TYPES (outer_type) == TYPE_ARG_TYPES (inner_type))
250 return true;
251
252 for (outer_parm = TYPE_ARG_TYPES (outer_type),
253 inner_parm = TYPE_ARG_TYPES (inner_type);
254 outer_parm && inner_parm;
255 outer_parm = TREE_CHAIN (outer_parm),
256 inner_parm = TREE_CHAIN (inner_parm))
257 if (!useless_type_conversion_p
258 (TYPE_MAIN_VARIANT (TREE_VALUE (outer_parm)),
259 TYPE_MAIN_VARIANT (TREE_VALUE (inner_parm))))
260 return false;
261
262 /* If there is a mismatch in the number of arguments the functions
263 are not compatible. */
264 if (outer_parm || inner_parm)
265 return false;
266
267 /* Defer to the target if necessary. */
268 if (TYPE_ATTRIBUTES (inner_type) || TYPE_ATTRIBUTES (outer_type))
269 return comp_type_attributes (outer_type, inner_type) != 0;
270
271 return true;
272 }
273
274 /* For aggregates we rely on TYPE_CANONICAL exclusively and require
275 explicit conversions for types involving to be structurally
276 compared types. */
277 else if (AGGREGATE_TYPE_P (inner_type)
278 && TREE_CODE (inner_type) == TREE_CODE (outer_type))
279 return TYPE_CANONICAL (inner_type)
280 && TYPE_CANONICAL (inner_type) == TYPE_CANONICAL (outer_type);
281
282 else if (TREE_CODE (inner_type) == OFFSET_TYPE
283 && TREE_CODE (outer_type) == OFFSET_TYPE)
284 return useless_type_conversion_p (TREE_TYPE (outer_type),
285 TREE_TYPE (inner_type))
286 && useless_type_conversion_p
287 (TYPE_OFFSET_BASETYPE (outer_type),
288 TYPE_OFFSET_BASETYPE (inner_type));
289
290 return false;
291 }
292
293
294 /* ----- Decl related ----- */
295
296 /* Set sequence SEQ to be the GIMPLE body for function FN. */
297
298 void
gimple_set_body(tree fndecl,gimple_seq seq)299 gimple_set_body (tree fndecl, gimple_seq seq)
300 {
301 struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
302 if (fn == NULL)
303 {
304 /* If FNDECL still does not have a function structure associated
305 with it, then it does not make sense for it to receive a
306 GIMPLE body. */
307 gcc_assert (seq == NULL);
308 }
309 else
310 fn->gimple_body = seq;
311 }
312
313
314 /* Return the body of GIMPLE statements for function FN. After the
315 CFG pass, the function body doesn't exist anymore because it has
316 been split up into basic blocks. In this case, it returns
317 NULL. */
318
319 gimple_seq
gimple_body(tree fndecl)320 gimple_body (tree fndecl)
321 {
322 struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
323 return fn ? fn->gimple_body : NULL;
324 }
325
326 /* Return true when FNDECL has Gimple body either in unlowered
327 or CFG form. */
328 bool
gimple_has_body_p(tree fndecl)329 gimple_has_body_p (tree fndecl)
330 {
331 struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
332 return (gimple_body (fndecl) || (fn && fn->cfg && !(fn->curr_properties & PROP_rtl)));
333 }
334
335 /* Return a printable name for symbol DECL. */
336
337 const char *
gimple_decl_printable_name(tree decl,int verbosity)338 gimple_decl_printable_name (tree decl, int verbosity)
339 {
340 if (!DECL_NAME (decl))
341 return NULL;
342
343 if (HAS_DECL_ASSEMBLER_NAME_P (decl) && DECL_ASSEMBLER_NAME_SET_P (decl))
344 {
345 int dmgl_opts = DMGL_NO_OPTS;
346
347 if (verbosity >= 2)
348 {
349 dmgl_opts = DMGL_VERBOSE
350 | DMGL_ANSI
351 | DMGL_GNU_V3
352 | DMGL_RET_POSTFIX;
353 if (TREE_CODE (decl) == FUNCTION_DECL)
354 dmgl_opts |= DMGL_PARAMS;
355 }
356
357 const char *mangled_str
358 = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME_RAW (decl));
359 const char *str = cplus_demangle_v3 (mangled_str, dmgl_opts);
360 return str ? str : mangled_str;
361 }
362
363 return IDENTIFIER_POINTER (DECL_NAME (decl));
364 }
365
366
367 /* Create a new VAR_DECL and copy information from VAR to it. */
368
369 tree
copy_var_decl(tree var,tree name,tree type)370 copy_var_decl (tree var, tree name, tree type)
371 {
372 tree copy = build_decl (DECL_SOURCE_LOCATION (var), VAR_DECL, name, type);
373
374 TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (var);
375 TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (var);
376 DECL_NOT_GIMPLE_REG_P (copy) = DECL_NOT_GIMPLE_REG_P (var);
377 DECL_ARTIFICIAL (copy) = DECL_ARTIFICIAL (var);
378 DECL_IGNORED_P (copy) = DECL_IGNORED_P (var);
379 DECL_CONTEXT (copy) = DECL_CONTEXT (var);
380 TREE_USED (copy) = 1;
381 DECL_SEEN_IN_BIND_EXPR_P (copy) = 1;
382 DECL_ATTRIBUTES (copy) = DECL_ATTRIBUTES (var);
383 if (DECL_USER_ALIGN (var))
384 {
385 SET_DECL_ALIGN (copy, DECL_ALIGN (var));
386 DECL_USER_ALIGN (copy) = 1;
387 }
388
389 copy_warning (copy, var);
390 return copy;
391 }
392
393 /* Strip off a legitimate source ending from the input string NAME of
394 length LEN. Rather than having to know the names used by all of
395 our front ends, we strip off an ending of a period followed by
396 up to four characters. (like ".cpp".) */
397
398 static inline void
remove_suffix(char * name,int len)399 remove_suffix (char *name, int len)
400 {
401 int i;
402
403 for (i = 2; i < 7 && len > i; i++)
404 {
405 if (name[len - i] == '.')
406 {
407 name[len - i] = '\0';
408 break;
409 }
410 }
411 }
412
413 /* Create a new temporary name with PREFIX. Return an identifier. */
414
415 static GTY(()) unsigned int tmp_var_id_num;
416
417 tree
create_tmp_var_name(const char * prefix)418 create_tmp_var_name (const char *prefix)
419 {
420 char *tmp_name;
421
422 if (prefix)
423 {
424 char *preftmp = ASTRDUP (prefix);
425
426 remove_suffix (preftmp, strlen (preftmp));
427 clean_symbol_name (preftmp);
428
429 prefix = preftmp;
430 }
431
432 ASM_FORMAT_PRIVATE_NAME (tmp_name, prefix ? prefix : "T", tmp_var_id_num++);
433 return get_identifier (tmp_name);
434 }
435
436 /* Create a new temporary variable declaration of type TYPE.
437 Do NOT push it into the current binding. */
438
439 tree
create_tmp_var_raw(tree type,const char * prefix)440 create_tmp_var_raw (tree type, const char *prefix)
441 {
442 tree tmp_var;
443
444 tmp_var = build_decl (input_location,
445 VAR_DECL, prefix ? create_tmp_var_name (prefix) : NULL,
446 type);
447
448 /* The variable was declared by the compiler. */
449 DECL_ARTIFICIAL (tmp_var) = 1;
450 /* And we don't want debug info for it. */
451 DECL_IGNORED_P (tmp_var) = 1;
452 /* And we don't want even the fancy names of those printed in
453 -fdump-final-insns= dumps. */
454 DECL_NAMELESS (tmp_var) = 1;
455
456 /* Make the variable writable. */
457 TREE_READONLY (tmp_var) = 0;
458
459 DECL_EXTERNAL (tmp_var) = 0;
460 TREE_STATIC (tmp_var) = 0;
461 TREE_USED (tmp_var) = 1;
462
463 return tmp_var;
464 }
465
466 /* Create a new temporary variable declaration of type TYPE. DO push the
467 variable into the current binding. Further, assume that this is called
468 only from gimplification or optimization, at which point the creation of
469 certain types are bugs. */
470
471 tree
create_tmp_var(tree type,const char * prefix)472 create_tmp_var (tree type, const char *prefix)
473 {
474 tree tmp_var;
475
476 /* We don't allow types that are addressable (meaning we can't make copies),
477 or incomplete. We also used to reject every variable size objects here,
478 but now support those for which a constant upper bound can be obtained.
479 The processing for variable sizes is performed in gimple_add_tmp_var,
480 point at which it really matters and possibly reached via paths not going
481 through this function, e.g. after direct calls to create_tmp_var_raw. */
482 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
483
484 tmp_var = create_tmp_var_raw (type, prefix);
485 gimple_add_tmp_var (tmp_var);
486 return tmp_var;
487 }
488
489 /* Create a new temporary variable declaration of type TYPE by calling
490 create_tmp_var and if TYPE is a vector or a complex number, mark the new
491 temporary as gimple register. */
492
493 tree
create_tmp_reg(tree type,const char * prefix)494 create_tmp_reg (tree type, const char *prefix)
495 {
496 return create_tmp_var (type, prefix);
497 }
498
499 /* Create a new temporary variable declaration of type TYPE by calling
500 create_tmp_var and if TYPE is a vector or a complex number, mark the new
501 temporary as gimple register. */
502
503 tree
create_tmp_reg_fn(struct function * fn,tree type,const char * prefix)504 create_tmp_reg_fn (struct function *fn, tree type, const char *prefix)
505 {
506 tree tmp;
507
508 tmp = create_tmp_var_raw (type, prefix);
509 gimple_add_tmp_var_fn (fn, tmp);
510
511 return tmp;
512 }
513
514
515 /* ----- Expression related ----- */
516
517 /* Extract the operands and code for expression EXPR into *SUBCODE_P,
518 *OP1_P, *OP2_P and *OP3_P respectively. */
519
520 void
extract_ops_from_tree(tree expr,enum tree_code * subcode_p,tree * op1_p,tree * op2_p,tree * op3_p)521 extract_ops_from_tree (tree expr, enum tree_code *subcode_p, tree *op1_p,
522 tree *op2_p, tree *op3_p)
523 {
524 *subcode_p = TREE_CODE (expr);
525 switch (get_gimple_rhs_class (*subcode_p))
526 {
527 case GIMPLE_TERNARY_RHS:
528 {
529 *op1_p = TREE_OPERAND (expr, 0);
530 *op2_p = TREE_OPERAND (expr, 1);
531 *op3_p = TREE_OPERAND (expr, 2);
532 break;
533 }
534 case GIMPLE_BINARY_RHS:
535 {
536 *op1_p = TREE_OPERAND (expr, 0);
537 *op2_p = TREE_OPERAND (expr, 1);
538 *op3_p = NULL_TREE;
539 break;
540 }
541 case GIMPLE_UNARY_RHS:
542 {
543 *op1_p = TREE_OPERAND (expr, 0);
544 *op2_p = NULL_TREE;
545 *op3_p = NULL_TREE;
546 break;
547 }
548 case GIMPLE_SINGLE_RHS:
549 {
550 *op1_p = expr;
551 *op2_p = NULL_TREE;
552 *op3_p = NULL_TREE;
553 break;
554 }
555 default:
556 gcc_unreachable ();
557 }
558 }
559
560 /* Extract operands for a GIMPLE_COND statement out of COND_EXPR tree COND. */
561
562 void
gimple_cond_get_ops_from_tree(tree cond,enum tree_code * code_p,tree * lhs_p,tree * rhs_p)563 gimple_cond_get_ops_from_tree (tree cond, enum tree_code *code_p,
564 tree *lhs_p, tree *rhs_p)
565 {
566 gcc_assert (COMPARISON_CLASS_P (cond)
567 || TREE_CODE (cond) == TRUTH_NOT_EXPR
568 || is_gimple_min_invariant (cond)
569 || SSA_VAR_P (cond));
570 gcc_checking_assert (!tree_could_throw_p (cond));
571
572 extract_ops_from_tree (cond, code_p, lhs_p, rhs_p);
573
574 /* Canonicalize conditionals of the form 'if (!VAL)'. */
575 if (*code_p == TRUTH_NOT_EXPR)
576 {
577 *code_p = EQ_EXPR;
578 gcc_assert (*lhs_p && *rhs_p == NULL_TREE);
579 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
580 }
581 /* Canonicalize conditionals of the form 'if (VAL)' */
582 else if (TREE_CODE_CLASS (*code_p) != tcc_comparison)
583 {
584 *code_p = NE_EXPR;
585 gcc_assert (*lhs_p && *rhs_p == NULL_TREE);
586 *rhs_p = build_zero_cst (TREE_TYPE (*lhs_p));
587 }
588 }
589
590 /* Return true if T is a valid LHS for a GIMPLE assignment expression. */
591
592 bool
is_gimple_lvalue(tree t)593 is_gimple_lvalue (tree t)
594 {
595 return (is_gimple_addressable (t)
596 || TREE_CODE (t) == WITH_SIZE_EXPR
597 /* These are complex lvalues, but don't have addresses, so they
598 go here. */
599 || TREE_CODE (t) == BIT_FIELD_REF);
600 }
601
602 /* Helper for is_gimple_condexpr and is_gimple_condexpr_for_cond. */
603
604 static bool
is_gimple_condexpr_1(tree t,bool allow_traps,bool allow_cplx)605 is_gimple_condexpr_1 (tree t, bool allow_traps, bool allow_cplx)
606 {
607 tree op0;
608 return (is_gimple_val (t)
609 || (COMPARISON_CLASS_P (t)
610 && (allow_traps || !tree_could_throw_p (t))
611 && ((op0 = TREE_OPERAND (t, 0)), true)
612 && (allow_cplx || TREE_CODE (TREE_TYPE (op0)) != COMPLEX_TYPE)
613 && is_gimple_val (op0)
614 && is_gimple_val (TREE_OPERAND (t, 1))));
615 }
616
617 /* Return true if T is a GIMPLE condition. */
618
619 bool
is_gimple_condexpr(tree t)620 is_gimple_condexpr (tree t)
621 {
622 /* Always split out _Complex type compares since complex lowering
623 doesn't handle this case. */
624 return is_gimple_condexpr_1 (t, true, false);
625 }
626
627 /* Like is_gimple_condexpr, but does not allow T to trap. */
628
629 bool
is_gimple_condexpr_for_cond(tree t)630 is_gimple_condexpr_for_cond (tree t)
631 {
632 return is_gimple_condexpr_1 (t, false, true);
633 }
634
635 /* Return true if T is a gimple address. */
636
637 bool
is_gimple_address(const_tree t)638 is_gimple_address (const_tree t)
639 {
640 tree op;
641
642 if (TREE_CODE (t) != ADDR_EXPR)
643 return false;
644
645 op = TREE_OPERAND (t, 0);
646 while (handled_component_p (op))
647 {
648 if ((TREE_CODE (op) == ARRAY_REF
649 || TREE_CODE (op) == ARRAY_RANGE_REF)
650 && !is_gimple_val (TREE_OPERAND (op, 1)))
651 return false;
652
653 op = TREE_OPERAND (op, 0);
654 }
655
656 if (CONSTANT_CLASS_P (op)
657 || TREE_CODE (op) == TARGET_MEM_REF
658 || TREE_CODE (op) == MEM_REF)
659 return true;
660
661 switch (TREE_CODE (op))
662 {
663 case PARM_DECL:
664 case RESULT_DECL:
665 case LABEL_DECL:
666 case FUNCTION_DECL:
667 case VAR_DECL:
668 case CONST_DECL:
669 return true;
670
671 default:
672 return false;
673 }
674 }
675
676 /* Return true if T is a gimple invariant address. */
677
678 bool
is_gimple_invariant_address(const_tree t)679 is_gimple_invariant_address (const_tree t)
680 {
681 const_tree op;
682
683 if (TREE_CODE (t) != ADDR_EXPR)
684 return false;
685
686 op = strip_invariant_refs (TREE_OPERAND (t, 0));
687 if (!op)
688 return false;
689
690 if (TREE_CODE (op) == MEM_REF)
691 {
692 const_tree op0 = TREE_OPERAND (op, 0);
693 return (TREE_CODE (op0) == ADDR_EXPR
694 && (CONSTANT_CLASS_P (TREE_OPERAND (op0, 0))
695 || decl_address_invariant_p (TREE_OPERAND (op0, 0))));
696 }
697
698 return CONSTANT_CLASS_P (op) || decl_address_invariant_p (op);
699 }
700
701 /* Return true if T is a gimple invariant address at IPA level
702 (so addresses of variables on stack are not allowed). */
703
704 bool
is_gimple_ip_invariant_address(const_tree t)705 is_gimple_ip_invariant_address (const_tree t)
706 {
707 const_tree op;
708
709 if (TREE_CODE (t) != ADDR_EXPR)
710 return false;
711
712 op = strip_invariant_refs (TREE_OPERAND (t, 0));
713 if (!op)
714 return false;
715
716 if (TREE_CODE (op) == MEM_REF)
717 {
718 const_tree op0 = TREE_OPERAND (op, 0);
719 return (TREE_CODE (op0) == ADDR_EXPR
720 && (CONSTANT_CLASS_P (TREE_OPERAND (op0, 0))
721 || decl_address_ip_invariant_p (TREE_OPERAND (op0, 0))));
722 }
723
724 return CONSTANT_CLASS_P (op) || decl_address_ip_invariant_p (op);
725 }
726
727 /* Return true if T is a GIMPLE minimal invariant. It's a restricted
728 form of function invariant. */
729
730 bool
is_gimple_min_invariant(const_tree t)731 is_gimple_min_invariant (const_tree t)
732 {
733 if (TREE_CODE (t) == ADDR_EXPR)
734 return is_gimple_invariant_address (t);
735
736 return is_gimple_constant (t);
737 }
738
739 /* Return true if T is a GIMPLE interprocedural invariant. It's a restricted
740 form of gimple minimal invariant. */
741
742 bool
is_gimple_ip_invariant(const_tree t)743 is_gimple_ip_invariant (const_tree t)
744 {
745 if (TREE_CODE (t) == ADDR_EXPR)
746 return is_gimple_ip_invariant_address (t);
747
748 return is_gimple_constant (t);
749 }
750
751 /* Return true if T is a non-aggregate register variable. */
752
753 bool
is_gimple_reg(tree t)754 is_gimple_reg (tree t)
755 {
756 if (virtual_operand_p (t))
757 return false;
758
759 if (TREE_CODE (t) == SSA_NAME)
760 return true;
761
762 if (!is_gimple_variable (t))
763 return false;
764
765 if (!is_gimple_reg_type (TREE_TYPE (t)))
766 return false;
767
768 /* A volatile decl is not acceptable because we can't reuse it as
769 needed. We need to copy it into a temp first. */
770 if (TREE_THIS_VOLATILE (t))
771 return false;
772
773 /* We define "registers" as things that can be renamed as needed,
774 which with our infrastructure does not apply to memory. */
775 if (needs_to_live_in_memory (t))
776 return false;
777
778 /* Hard register variables are an interesting case. For those that
779 are call-clobbered, we don't know where all the calls are, since
780 we don't (want to) take into account which operations will turn
781 into libcalls at the rtl level. For those that are call-saved,
782 we don't currently model the fact that calls may in fact change
783 global hard registers, nor do we examine ASM_CLOBBERS at the tree
784 level, and so miss variable changes that might imply. All around,
785 it seems safest to not do too much optimization with these at the
786 tree level at all. We'll have to rely on the rtl optimizers to
787 clean this up, as there we've got all the appropriate bits exposed. */
788 if (TREE_CODE (t) == VAR_DECL && DECL_HARD_REGISTER (t))
789 return false;
790
791 /* Variables can be marked as having partial definitions, avoid
792 putting them into SSA form. */
793 return !DECL_NOT_GIMPLE_REG_P (t);
794 }
795
796
797 /* Return true if T is a GIMPLE rvalue, i.e. an identifier or a constant. */
798
799 bool
is_gimple_val(tree t)800 is_gimple_val (tree t)
801 {
802 /* Make loads from volatiles and memory vars explicit. */
803 if (is_gimple_variable (t)
804 && is_gimple_reg_type (TREE_TYPE (t))
805 && !is_gimple_reg (t))
806 return false;
807
808 return (is_gimple_variable (t) || is_gimple_min_invariant (t));
809 }
810
811 /* Similarly, but accept hard registers as inputs to asm statements. */
812
813 bool
is_gimple_asm_val(tree t)814 is_gimple_asm_val (tree t)
815 {
816 if (TREE_CODE (t) == VAR_DECL && DECL_HARD_REGISTER (t))
817 return true;
818
819 return is_gimple_val (t);
820 }
821
822 /* Return true if T is a GIMPLE minimal lvalue. */
823
824 bool
is_gimple_min_lval(tree t)825 is_gimple_min_lval (tree t)
826 {
827 if (!(t = CONST_CAST_TREE (strip_invariant_refs (t))))
828 return false;
829 return (is_gimple_id (t) || TREE_CODE (t) == MEM_REF);
830 }
831
832 /* Return true if T is a valid function operand of a CALL_EXPR. */
833
834 bool
is_gimple_call_addr(tree t)835 is_gimple_call_addr (tree t)
836 {
837 return (TREE_CODE (t) == OBJ_TYPE_REF || is_gimple_val (t));
838 }
839
840 /* Return true if T is a valid address operand of a MEM_REF. */
841
842 bool
is_gimple_mem_ref_addr(tree t)843 is_gimple_mem_ref_addr (tree t)
844 {
845 return (is_gimple_reg (t)
846 || TREE_CODE (t) == INTEGER_CST
847 || (TREE_CODE (t) == ADDR_EXPR
848 && (CONSTANT_CLASS_P (TREE_OPERAND (t, 0))
849 || decl_address_invariant_p (TREE_OPERAND (t, 0)))));
850 }
851
852 /* Hold trees marked addressable during expand. */
853
854 static hash_set<tree> *mark_addressable_queue;
855
856 /* Mark X as addressable or queue it up if called during expand. We
857 don't want to apply it immediately during expand because decls are
858 made addressable at that point due to RTL-only concerns, such as
859 uses of memcpy for block moves, and TREE_ADDRESSABLE changes
860 is_gimple_reg, which might make it seem like a variable that used
861 to be a gimple_reg shouldn't have been an SSA name. So we queue up
862 this flag setting and only apply it when we're done with GIMPLE and
863 only RTL issues matter. */
864
865 static void
mark_addressable_1(tree x)866 mark_addressable_1 (tree x)
867 {
868 if (!currently_expanding_to_rtl)
869 {
870 TREE_ADDRESSABLE (x) = 1;
871 return;
872 }
873
874 if (!mark_addressable_queue)
875 mark_addressable_queue = new hash_set<tree>();
876 mark_addressable_queue->add (x);
877 }
878
879 /* Adaptor for mark_addressable_1 for use in hash_set traversal. */
880
881 bool
mark_addressable_2(tree const & x,void * ATTRIBUTE_UNUSED=NULL)882 mark_addressable_2 (tree const &x, void * ATTRIBUTE_UNUSED = NULL)
883 {
884 mark_addressable_1 (x);
885 return false;
886 }
887
888 /* Mark all queued trees as addressable, and empty the queue. To be
889 called right after clearing CURRENTLY_EXPANDING_TO_RTL. */
890
891 void
flush_mark_addressable_queue()892 flush_mark_addressable_queue ()
893 {
894 gcc_assert (!currently_expanding_to_rtl);
895 if (mark_addressable_queue)
896 {
897 mark_addressable_queue->traverse<void*, mark_addressable_2> (NULL);
898 delete mark_addressable_queue;
899 mark_addressable_queue = NULL;
900 }
901 }
902
903 /* Mark X addressable. Unlike the langhook we expect X to be in gimple
904 form and we don't do any syntax checking. */
905
906 void
mark_addressable(tree x)907 mark_addressable (tree x)
908 {
909 if (TREE_CODE (x) == WITH_SIZE_EXPR)
910 x = TREE_OPERAND (x, 0);
911 while (handled_component_p (x))
912 x = TREE_OPERAND (x, 0);
913 if ((TREE_CODE (x) == MEM_REF
914 || TREE_CODE (x) == TARGET_MEM_REF)
915 && TREE_CODE (TREE_OPERAND (x, 0)) == ADDR_EXPR)
916 x = TREE_OPERAND (TREE_OPERAND (x, 0), 0);
917 if (!VAR_P (x)
918 && TREE_CODE (x) != PARM_DECL
919 && TREE_CODE (x) != RESULT_DECL)
920 return;
921 mark_addressable_1 (x);
922
923 /* Also mark the artificial SSA_NAME that points to the partition of X. */
924 if (TREE_CODE (x) == VAR_DECL
925 && !DECL_EXTERNAL (x)
926 && !TREE_STATIC (x)
927 && cfun->gimple_df != NULL
928 && cfun->gimple_df->decls_to_pointers != NULL)
929 {
930 tree *namep = cfun->gimple_df->decls_to_pointers->get (x);
931 if (namep)
932 mark_addressable_1 (*namep);
933 }
934 }
935
936 /* Returns true iff T is a valid RHS for an assignment to a renamed
937 user -- or front-end generated artificial -- variable. */
938
939 bool
is_gimple_reg_rhs(tree t)940 is_gimple_reg_rhs (tree t)
941 {
942 return get_gimple_rhs_class (TREE_CODE (t)) != GIMPLE_INVALID_RHS;
943 }
944
945 #include "gt-gimple-expr.h"
946