xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/df-scan.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /* Scanning of rtl for dataflow analysis.
2    Copyright (C) 1999-2015 Free Software Foundation, Inc.
3    Originally contributed by Michael P. Hayes
4              (m.hayes@elec.canterbury.ac.nz, mhayes@redhat.com)
5    Major rewrite contributed by Danny Berlin (dberlin@dberlin.org)
6              and Kenneth Zadeck (zadeck@naturalbridge.com).
7 
8 This file is part of GCC.
9 
10 GCC is free software; you can redistribute it and/or modify it under
11 the terms of the GNU General Public License as published by the Free
12 Software Foundation; either version 3, or (at your option) any later
13 version.
14 
15 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
16 WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18 for more details.
19 
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3.  If not see
22 <http://www.gnu.org/licenses/>.  */
23 
24 #include "config.h"
25 #include "system.h"
26 #include "coretypes.h"
27 #include "tm.h"
28 #include "rtl.h"
29 #include "tm_p.h"
30 #include "insn-config.h"
31 #include "recog.h"
32 #include "hashtab.h"
33 #include "hash-set.h"
34 #include "machmode.h"
35 #include "vec.h"
36 #include "double-int.h"
37 #include "input.h"
38 #include "alias.h"
39 #include "symtab.h"
40 #include "wide-int.h"
41 #include "inchash.h"
42 #include "hard-reg-set.h"
43 #include "input.h"
44 #include "function.h"
45 #include "regs.h"
46 #include "alloc-pool.h"
47 #include "flags.h"
48 #include "predict.h"
49 #include "dominance.h"
50 #include "cfg.h"
51 #include "basic-block.h"
52 #include "sbitmap.h"
53 #include "bitmap.h"
54 #include "dumpfile.h"
55 #include "tree.h"
56 #include "target.h"
57 #include "target-def.h"
58 #include "df.h"
59 #include "emit-rtl.h"  /* FIXME: Can go away once crtl is moved to rtl.h.  */
60 
61 
62 typedef struct df_mw_hardreg *df_mw_hardreg_ptr;
63 
64 
65 #ifndef HAVE_epilogue
66 #define HAVE_epilogue 0
67 #endif
68 #ifndef HAVE_prologue
69 #define HAVE_prologue 0
70 #endif
71 #ifndef HAVE_sibcall_epilogue
72 #define HAVE_sibcall_epilogue 0
73 #endif
74 
75 #ifndef EPILOGUE_USES
76 #define EPILOGUE_USES(REGNO)  0
77 #endif
78 
79 /* The set of hard registers in eliminables[i].from. */
80 
81 static HARD_REG_SET elim_reg_set;
82 
83 /* Initialize ur_in and ur_out as if all hard registers were partially
84    available.  */
85 
86 struct df_collection_rec
87 {
88   auto_vec<df_ref, 128> def_vec;
89   auto_vec<df_ref, 32> use_vec;
90   auto_vec<df_ref, 32> eq_use_vec;
91   auto_vec<df_mw_hardreg_ptr, 32> mw_vec;
92 };
93 
94 static void df_ref_record (enum df_ref_class, struct df_collection_rec *,
95 			   rtx, rtx *,
96 			   basic_block, struct df_insn_info *,
97 			   enum df_ref_type, int ref_flags);
98 static void df_def_record_1 (struct df_collection_rec *, rtx *,
99 			     basic_block, struct df_insn_info *,
100 			     int ref_flags);
101 static void df_defs_record (struct df_collection_rec *, rtx,
102 			    basic_block, struct df_insn_info *,
103 			    int ref_flags);
104 static void df_uses_record (struct df_collection_rec *,
105 			    rtx *, enum df_ref_type,
106 			    basic_block, struct df_insn_info *,
107 			    int ref_flags);
108 
109 static void df_install_ref_incremental (df_ref);
110 static void df_insn_refs_collect (struct df_collection_rec*,
111 				  basic_block, struct df_insn_info *);
112 static void df_canonize_collection_rec (struct df_collection_rec *);
113 
114 static void df_get_regular_block_artificial_uses (bitmap);
115 static void df_get_eh_block_artificial_uses (bitmap);
116 
117 static void df_record_entry_block_defs (bitmap);
118 static void df_record_exit_block_uses (bitmap);
119 static void df_get_exit_block_use_set (bitmap);
120 static void df_get_entry_block_def_set (bitmap);
121 static void df_grow_ref_info (struct df_ref_info *, unsigned int);
122 static void df_ref_chain_delete_du_chain (df_ref);
123 static void df_ref_chain_delete (df_ref);
124 
125 static void df_refs_add_to_chains (struct df_collection_rec *,
126 				   basic_block, rtx_insn *, unsigned int);
127 
128 static bool df_insn_refs_verify (struct df_collection_rec *, basic_block,
129 				 rtx_insn *, bool);
130 static void df_entry_block_defs_collect (struct df_collection_rec *, bitmap);
131 static void df_exit_block_uses_collect (struct df_collection_rec *, bitmap);
132 static void df_install_ref (df_ref, struct df_reg_info *,
133 			    struct df_ref_info *, bool);
134 
135 static int df_ref_compare (df_ref, df_ref);
136 static int df_ref_ptr_compare (const void *, const void *);
137 static int df_mw_compare (const df_mw_hardreg *, const df_mw_hardreg *);
138 static int df_mw_ptr_compare (const void *, const void *);
139 
140 static void df_insn_info_delete (unsigned int);
141 
142 /* Indexed by hardware reg number, is true if that register is ever
143    used in the current function.
144 
145    In df-scan.c, this is set up to record the hard regs used
146    explicitly.  Reload adds in the hard regs used for holding pseudo
147    regs.  Final uses it to generate the code in the function prologue
148    and epilogue to save and restore registers as needed.  */
149 
150 static bool regs_ever_live[FIRST_PSEUDO_REGISTER];
151 
152 /* Flags used to tell df_refs_add_to_chains() which vectors it should copy. */
153 static const unsigned int copy_defs = 0x1;
154 static const unsigned int copy_uses = 0x2;
155 static const unsigned int copy_eq_uses = 0x4;
156 static const unsigned int copy_mw = 0x8;
157 static const unsigned int copy_all = copy_defs | copy_uses | copy_eq_uses
158 | copy_mw;
159 
160 /*----------------------------------------------------------------------------
161    SCANNING DATAFLOW PROBLEM
162 
163    There are several ways in which scanning looks just like the other
164    dataflow problems.  It shares the all the mechanisms for local info
165    as well as basic block info.  Where it differs is when and how often
166    it gets run.  It also has no need for the iterative solver.
167 ----------------------------------------------------------------------------*/
168 
169 /* Problem data for the scanning dataflow function.  */
170 struct df_scan_problem_data
171 {
172   alloc_pool ref_base_pool;
173   alloc_pool ref_artificial_pool;
174   alloc_pool ref_regular_pool;
175   alloc_pool insn_pool;
176   alloc_pool reg_pool;
177   alloc_pool mw_reg_pool;
178   bitmap_obstack reg_bitmaps;
179   bitmap_obstack insn_bitmaps;
180 };
181 
182 typedef struct df_scan_bb_info *df_scan_bb_info_t;
183 
184 
185 /* Internal function to shut down the scanning problem.  */
186 static void
187 df_scan_free_internal (void)
188 {
189   struct df_scan_problem_data *problem_data
190     = (struct df_scan_problem_data *) df_scan->problem_data;
191 
192   free (df->def_info.refs);
193   free (df->def_info.begin);
194   free (df->def_info.count);
195   memset (&df->def_info, 0, (sizeof (struct df_ref_info)));
196 
197   free (df->use_info.refs);
198   free (df->use_info.begin);
199   free (df->use_info.count);
200   memset (&df->use_info, 0, (sizeof (struct df_ref_info)));
201 
202   free (df->def_regs);
203   df->def_regs = NULL;
204   free (df->use_regs);
205   df->use_regs = NULL;
206   free (df->eq_use_regs);
207   df->eq_use_regs = NULL;
208   df->regs_size = 0;
209   DF_REG_SIZE (df) = 0;
210 
211   free (df->insns);
212   df->insns = NULL;
213   DF_INSN_SIZE () = 0;
214 
215   free (df_scan->block_info);
216   df_scan->block_info = NULL;
217   df_scan->block_info_size = 0;
218 
219   bitmap_clear (&df->hardware_regs_used);
220   bitmap_clear (&df->regular_block_artificial_uses);
221   bitmap_clear (&df->eh_block_artificial_uses);
222   BITMAP_FREE (df->entry_block_defs);
223   BITMAP_FREE (df->exit_block_uses);
224   bitmap_clear (&df->insns_to_delete);
225   bitmap_clear (&df->insns_to_rescan);
226   bitmap_clear (&df->insns_to_notes_rescan);
227 
228   free_alloc_pool (problem_data->ref_base_pool);
229   free_alloc_pool (problem_data->ref_artificial_pool);
230   free_alloc_pool (problem_data->ref_regular_pool);
231   free_alloc_pool (problem_data->insn_pool);
232   free_alloc_pool (problem_data->reg_pool);
233   free_alloc_pool (problem_data->mw_reg_pool);
234   bitmap_obstack_release (&problem_data->reg_bitmaps);
235   bitmap_obstack_release (&problem_data->insn_bitmaps);
236   free (df_scan->problem_data);
237 }
238 
239 
240 /* Free basic block info.  */
241 
242 static void
243 df_scan_free_bb_info (basic_block bb, void *vbb_info)
244 {
245   struct df_scan_bb_info *bb_info = (struct df_scan_bb_info *) vbb_info;
246   unsigned int bb_index = bb->index;
247   rtx_insn *insn;
248 
249   FOR_BB_INSNS (bb, insn)
250     if (INSN_P (insn))
251       df_insn_info_delete (INSN_UID (insn));
252 
253   if (bb_index < df_scan->block_info_size)
254     bb_info = df_scan_get_bb_info (bb_index);
255 
256   /* Get rid of any artificial uses or defs.  */
257   df_ref_chain_delete_du_chain (bb_info->artificial_defs);
258   df_ref_chain_delete_du_chain (bb_info->artificial_uses);
259   df_ref_chain_delete (bb_info->artificial_defs);
260   df_ref_chain_delete (bb_info->artificial_uses);
261   bb_info->artificial_defs = NULL;
262   bb_info->artificial_uses = NULL;
263 }
264 
265 
266 /* Allocate the problem data for the scanning problem.  This should be
267    called when the problem is created or when the entire function is to
268    be rescanned.  */
269 void
270 df_scan_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
271 {
272   struct df_scan_problem_data *problem_data;
273   unsigned int insn_num = get_max_uid () + 1;
274   unsigned int block_size = 512;
275   basic_block bb;
276 
277   /* Given the number of pools, this is really faster than tearing
278      everything apart.  */
279   if (df_scan->problem_data)
280     df_scan_free_internal ();
281 
282   problem_data = XNEW (struct df_scan_problem_data);
283   df_scan->problem_data = problem_data;
284   df_scan->computed = true;
285 
286   problem_data->ref_base_pool
287     = create_alloc_pool ("df_scan ref base",
288 			 sizeof (struct df_base_ref), block_size);
289   problem_data->ref_artificial_pool
290     = create_alloc_pool ("df_scan ref artificial",
291 			 sizeof (struct df_artificial_ref), block_size);
292   problem_data->ref_regular_pool
293     = create_alloc_pool ("df_scan ref regular",
294 			 sizeof (struct df_regular_ref), block_size);
295   problem_data->insn_pool
296     = create_alloc_pool ("df_scan insn",
297 			 sizeof (struct df_insn_info), block_size);
298   problem_data->reg_pool
299     = create_alloc_pool ("df_scan reg",
300 			 sizeof (struct df_reg_info), block_size);
301   problem_data->mw_reg_pool
302     = create_alloc_pool ("df_scan mw_reg",
303 			 sizeof (struct df_mw_hardreg), block_size / 16);
304 
305   bitmap_obstack_initialize (&problem_data->reg_bitmaps);
306   bitmap_obstack_initialize (&problem_data->insn_bitmaps);
307 
308   insn_num += insn_num / 4;
309   df_grow_reg_info ();
310 
311   df_grow_insn_info ();
312   df_grow_bb_info (df_scan);
313 
314   FOR_ALL_BB_FN (bb, cfun)
315     {
316       unsigned int bb_index = bb->index;
317       struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb_index);
318       bb_info->artificial_defs = NULL;
319       bb_info->artificial_uses = NULL;
320     }
321 
322   bitmap_initialize (&df->hardware_regs_used, &problem_data->reg_bitmaps);
323   bitmap_initialize (&df->regular_block_artificial_uses, &problem_data->reg_bitmaps);
324   bitmap_initialize (&df->eh_block_artificial_uses, &problem_data->reg_bitmaps);
325   df->entry_block_defs = BITMAP_ALLOC (&problem_data->reg_bitmaps);
326   df->exit_block_uses = BITMAP_ALLOC (&problem_data->reg_bitmaps);
327   bitmap_initialize (&df->insns_to_delete, &problem_data->insn_bitmaps);
328   bitmap_initialize (&df->insns_to_rescan, &problem_data->insn_bitmaps);
329   bitmap_initialize (&df->insns_to_notes_rescan, &problem_data->insn_bitmaps);
330   df_scan->optional_p = false;
331 }
332 
333 
334 /* Free all of the data associated with the scan problem.  */
335 
336 static void
337 df_scan_free (void)
338 {
339   if (df_scan->problem_data)
340     df_scan_free_internal ();
341 
342   if (df->blocks_to_analyze)
343     {
344       BITMAP_FREE (df->blocks_to_analyze);
345       df->blocks_to_analyze = NULL;
346     }
347 
348   free (df_scan);
349 }
350 
351 /* Dump the preamble for DF_SCAN dump. */
352 static void
353 df_scan_start_dump (FILE *file ATTRIBUTE_UNUSED)
354 {
355   int i;
356   int dcount = 0;
357   int ucount = 0;
358   int ecount = 0;
359   int icount = 0;
360   int ccount = 0;
361   basic_block bb;
362   rtx_insn *insn;
363 
364   fprintf (file, ";;  invalidated by call \t");
365   df_print_regset (file, regs_invalidated_by_call_regset);
366   fprintf (file, ";;  hardware regs used \t");
367   df_print_regset (file, &df->hardware_regs_used);
368   fprintf (file, ";;  regular block artificial uses \t");
369   df_print_regset (file, &df->regular_block_artificial_uses);
370   fprintf (file, ";;  eh block artificial uses \t");
371   df_print_regset (file, &df->eh_block_artificial_uses);
372   fprintf (file, ";;  entry block defs \t");
373   df_print_regset (file, df->entry_block_defs);
374   fprintf (file, ";;  exit block uses \t");
375   df_print_regset (file, df->exit_block_uses);
376   fprintf (file, ";;  regs ever live \t");
377   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
378     if (df_regs_ever_live_p (i))
379       fprintf (file, " %d[%s]", i, reg_names[i]);
380   fprintf (file, "\n;;  ref usage \t");
381 
382   for (i = 0; i < (int)df->regs_inited; i++)
383     if (DF_REG_DEF_COUNT (i) || DF_REG_USE_COUNT (i) || DF_REG_EQ_USE_COUNT (i))
384       {
385 	const char * sep = "";
386 
387 	fprintf (file, "r%d={", i);
388 	if (DF_REG_DEF_COUNT (i))
389 	  {
390 	    fprintf (file, "%dd", DF_REG_DEF_COUNT (i));
391 	    sep = ",";
392 	    dcount += DF_REG_DEF_COUNT (i);
393 	  }
394 	if (DF_REG_USE_COUNT (i))
395 	  {
396 	    fprintf (file, "%s%du", sep, DF_REG_USE_COUNT (i));
397 	    sep = ",";
398 	    ucount += DF_REG_USE_COUNT (i);
399 	  }
400 	if (DF_REG_EQ_USE_COUNT (i))
401 	  {
402 	    fprintf (file, "%s%de", sep, DF_REG_EQ_USE_COUNT (i));
403 	    ecount += DF_REG_EQ_USE_COUNT (i);
404 	  }
405 	fprintf (file, "} ");
406       }
407 
408   FOR_EACH_BB_FN (bb, cfun)
409     FOR_BB_INSNS (bb, insn)
410       if (INSN_P (insn))
411 	{
412 	  if (CALL_P (insn))
413 	    ccount++;
414 	  else
415 	    icount++;
416 	}
417 
418   fprintf (file, "\n;;    total ref usage %d{%dd,%du,%de}"
419 		 " in %d{%d regular + %d call} insns.\n",
420 		 dcount + ucount + ecount, dcount, ucount, ecount,
421 		 icount + ccount, icount, ccount);
422 }
423 
424 /* Dump the bb_info for a given basic block. */
425 static void
426 df_scan_start_block (basic_block bb, FILE *file)
427 {
428   struct df_scan_bb_info *bb_info
429     = df_scan_get_bb_info (bb->index);
430 
431   if (bb_info)
432     {
433       fprintf (file, ";; bb %d artificial_defs: ", bb->index);
434       df_refs_chain_dump (bb_info->artificial_defs, true, file);
435       fprintf (file, "\n;; bb %d artificial_uses: ", bb->index);
436       df_refs_chain_dump (bb_info->artificial_uses, true, file);
437       fprintf (file, "\n");
438     }
439 #if 0
440   {
441     rtx_insn *insn;
442     FOR_BB_INSNS (bb, insn)
443       if (INSN_P (insn))
444 	df_insn_debug (insn, false, file);
445   }
446 #endif
447 }
448 
449 static struct df_problem problem_SCAN =
450 {
451   DF_SCAN,                    /* Problem id.  */
452   DF_NONE,                    /* Direction.  */
453   df_scan_alloc,              /* Allocate the problem specific data.  */
454   NULL,                       /* Reset global information.  */
455   df_scan_free_bb_info,       /* Free basic block info.  */
456   NULL,                       /* Local compute function.  */
457   NULL,                       /* Init the solution specific data.  */
458   NULL,                       /* Iterative solver.  */
459   NULL,                       /* Confluence operator 0.  */
460   NULL,                       /* Confluence operator n.  */
461   NULL,                       /* Transfer function.  */
462   NULL,                       /* Finalize function.  */
463   df_scan_free,               /* Free all of the problem information.  */
464   NULL,                       /* Remove this problem from the stack of dataflow problems.  */
465   df_scan_start_dump,         /* Debugging.  */
466   df_scan_start_block,        /* Debugging start block.  */
467   NULL,                       /* Debugging end block.  */
468   NULL,                       /* Debugging start insn.  */
469   NULL,                       /* Debugging end insn.  */
470   NULL,                       /* Incremental solution verify start.  */
471   NULL,                       /* Incremental solution verify end.  */
472   NULL,                       /* Dependent problem.  */
473   sizeof (struct df_scan_bb_info),/* Size of entry of block_info array.  */
474   TV_DF_SCAN,                 /* Timing variable.  */
475   false                       /* Reset blocks on dropping out of blocks_to_analyze.  */
476 };
477 
478 
479 /* Create a new DATAFLOW instance and add it to an existing instance
480    of DF.  The returned structure is what is used to get at the
481    solution.  */
482 
483 void
484 df_scan_add_problem (void)
485 {
486   df_add_problem (&problem_SCAN);
487 }
488 
489 
490 /*----------------------------------------------------------------------------
491    Storage Allocation Utilities
492 ----------------------------------------------------------------------------*/
493 
494 
495 /* First, grow the reg_info information.  If the current size is less than
496    the number of pseudos, grow to 25% more than the number of
497    pseudos.
498 
499    Second, assure that all of the slots up to max_reg_num have been
500    filled with reg_info structures.  */
501 
502 void
503 df_grow_reg_info (void)
504 {
505   unsigned int max_reg = max_reg_num ();
506   unsigned int new_size = max_reg;
507   struct df_scan_problem_data *problem_data
508     = (struct df_scan_problem_data *) df_scan->problem_data;
509   unsigned int i;
510 
511   if (df->regs_size < new_size)
512     {
513       new_size += new_size / 4;
514       df->def_regs = XRESIZEVEC (struct df_reg_info *, df->def_regs, new_size);
515       df->use_regs = XRESIZEVEC (struct df_reg_info *, df->use_regs, new_size);
516       df->eq_use_regs = XRESIZEVEC (struct df_reg_info *, df->eq_use_regs,
517 				    new_size);
518       df->def_info.begin = XRESIZEVEC (unsigned, df->def_info.begin, new_size);
519       df->def_info.count = XRESIZEVEC (unsigned, df->def_info.count, new_size);
520       df->use_info.begin = XRESIZEVEC (unsigned, df->use_info.begin, new_size);
521       df->use_info.count = XRESIZEVEC (unsigned, df->use_info.count, new_size);
522       df->regs_size = new_size;
523     }
524 
525   for (i = df->regs_inited; i < max_reg; i++)
526     {
527       struct df_reg_info *reg_info;
528 
529       reg_info = (struct df_reg_info *) pool_alloc (problem_data->reg_pool);
530       memset (reg_info, 0, sizeof (struct df_reg_info));
531       df->def_regs[i] = reg_info;
532       reg_info = (struct df_reg_info *) pool_alloc (problem_data->reg_pool);
533       memset (reg_info, 0, sizeof (struct df_reg_info));
534       df->use_regs[i] = reg_info;
535       reg_info = (struct df_reg_info *) pool_alloc (problem_data->reg_pool);
536       memset (reg_info, 0, sizeof (struct df_reg_info));
537       df->eq_use_regs[i] = reg_info;
538       df->def_info.begin[i] = 0;
539       df->def_info.count[i] = 0;
540       df->use_info.begin[i] = 0;
541       df->use_info.count[i] = 0;
542     }
543 
544   df->regs_inited = max_reg;
545 }
546 
547 
548 /* Grow the ref information.  */
549 
550 static void
551 df_grow_ref_info (struct df_ref_info *ref_info, unsigned int new_size)
552 {
553   if (ref_info->refs_size < new_size)
554     {
555       ref_info->refs = XRESIZEVEC (df_ref, ref_info->refs, new_size);
556       memset (ref_info->refs + ref_info->refs_size, 0,
557 	      (new_size - ref_info->refs_size) *sizeof (df_ref));
558       ref_info->refs_size = new_size;
559     }
560 }
561 
562 
563 /* Check and grow the ref information if necessary.  This routine
564    guarantees total_size + BITMAP_ADDEND amount of entries in refs
565    array.  It updates ref_info->refs_size only and does not change
566    ref_info->total_size.  */
567 
568 static void
569 df_check_and_grow_ref_info (struct df_ref_info *ref_info,
570 			    unsigned bitmap_addend)
571 {
572   if (ref_info->refs_size < ref_info->total_size + bitmap_addend)
573     {
574       int new_size = ref_info->total_size + bitmap_addend;
575       new_size += ref_info->total_size / 4;
576       df_grow_ref_info (ref_info, new_size);
577     }
578 }
579 
580 
581 /* Grow the ref information.  If the current size is less than the
582    number of instructions, grow to 25% more than the number of
583    instructions.  */
584 
585 void
586 df_grow_insn_info (void)
587 {
588   unsigned int new_size = get_max_uid () + 1;
589   if (DF_INSN_SIZE () < new_size)
590     {
591       new_size += new_size / 4;
592       df->insns = XRESIZEVEC (struct df_insn_info *, df->insns, new_size);
593       memset (df->insns + df->insns_size, 0,
594 	      (new_size - DF_INSN_SIZE ()) *sizeof (struct df_insn_info *));
595       DF_INSN_SIZE () = new_size;
596     }
597 }
598 
599 
600 
601 
602 /*----------------------------------------------------------------------------
603    PUBLIC INTERFACES FOR SMALL GRAIN CHANGES TO SCANNING.
604 ----------------------------------------------------------------------------*/
605 
606 /* Rescan all of the block_to_analyze or all of the blocks in the
607    function if df_set_blocks if blocks_to_analyze is NULL;  */
608 
609 void
610 df_scan_blocks (void)
611 {
612   basic_block bb;
613 
614   df->def_info.ref_order = DF_REF_ORDER_NO_TABLE;
615   df->use_info.ref_order = DF_REF_ORDER_NO_TABLE;
616 
617   df_get_regular_block_artificial_uses (&df->regular_block_artificial_uses);
618   df_get_eh_block_artificial_uses (&df->eh_block_artificial_uses);
619 
620   bitmap_ior_into (&df->eh_block_artificial_uses,
621 		   &df->regular_block_artificial_uses);
622 
623   /* ENTRY and EXIT blocks have special defs/uses.  */
624   df_get_entry_block_def_set (df->entry_block_defs);
625   df_record_entry_block_defs (df->entry_block_defs);
626   df_get_exit_block_use_set (df->exit_block_uses);
627   df_record_exit_block_uses (df->exit_block_uses);
628   df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK));
629   df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK));
630 
631   /* Regular blocks */
632   FOR_EACH_BB_FN (bb, cfun)
633     {
634       unsigned int bb_index = bb->index;
635       df_bb_refs_record (bb_index, true);
636     }
637 }
638 
639 /* Create new refs under address LOC within INSN.  This function is
640    only used externally.  REF_FLAGS must be either 0 or DF_REF_IN_NOTE,
641    depending on whether LOC is inside PATTERN (INSN) or a note.  */
642 
643 void
644 df_uses_create (rtx *loc, rtx_insn *insn, int ref_flags)
645 {
646   gcc_assert (!(ref_flags & ~DF_REF_IN_NOTE));
647   df_uses_record (NULL, loc, DF_REF_REG_USE,
648                   BLOCK_FOR_INSN (insn),
649                   DF_INSN_INFO_GET (insn),
650                   ref_flags);
651 }
652 
653 static void
654 df_install_ref_incremental (df_ref ref)
655 {
656   struct df_reg_info **reg_info;
657   struct df_ref_info *ref_info;
658   df_ref *ref_ptr;
659   bool add_to_table;
660 
661   rtx_insn *insn = DF_REF_INSN (ref);
662   basic_block bb = BLOCK_FOR_INSN (insn);
663 
664   if (DF_REF_REG_DEF_P (ref))
665     {
666       reg_info = df->def_regs;
667       ref_info = &df->def_info;
668       ref_ptr = &DF_INSN_DEFS (insn);
669       add_to_table = ref_info->ref_order != DF_REF_ORDER_NO_TABLE;
670     }
671   else if (DF_REF_FLAGS (ref) & DF_REF_IN_NOTE)
672     {
673       reg_info = df->eq_use_regs;
674       ref_info = &df->use_info;
675       ref_ptr = &DF_INSN_EQ_USES (insn);
676       switch (ref_info->ref_order)
677 	{
678 	case DF_REF_ORDER_UNORDERED_WITH_NOTES:
679 	case DF_REF_ORDER_BY_REG_WITH_NOTES:
680 	case DF_REF_ORDER_BY_INSN_WITH_NOTES:
681 	  add_to_table = true;
682 	  break;
683 	default:
684 	  add_to_table = false;
685 	  break;
686 	}
687     }
688   else
689     {
690       reg_info = df->use_regs;
691       ref_info = &df->use_info;
692       ref_ptr = &DF_INSN_USES (insn);
693       add_to_table = ref_info->ref_order != DF_REF_ORDER_NO_TABLE;
694     }
695 
696   /* Do not add if ref is not in the right blocks.  */
697   if (add_to_table && df->analyze_subset)
698     add_to_table = bitmap_bit_p (df->blocks_to_analyze, bb->index);
699 
700   df_install_ref (ref, reg_info[DF_REF_REGNO (ref)], ref_info, add_to_table);
701 
702   if (add_to_table)
703     switch (ref_info->ref_order)
704       {
705       case DF_REF_ORDER_UNORDERED_WITH_NOTES:
706       case DF_REF_ORDER_BY_REG_WITH_NOTES:
707       case DF_REF_ORDER_BY_INSN_WITH_NOTES:
708 	ref_info->ref_order = DF_REF_ORDER_UNORDERED_WITH_NOTES;
709 	break;
710       default:
711 	ref_info->ref_order = DF_REF_ORDER_UNORDERED;
712 	break;
713       }
714 
715   while (*ref_ptr && df_ref_compare (*ref_ptr, ref) < 0)
716     ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
717 
718   DF_REF_NEXT_LOC (ref) = *ref_ptr;
719   *ref_ptr = ref;
720 
721 #if 0
722   if (dump_file)
723     {
724       fprintf (dump_file, "adding ref ");
725       df_ref_debug (ref, dump_file);
726     }
727 #endif
728   /* By adding the ref directly, df_insn_rescan my not find any
729      differences even though the block will have changed.  So we need
730      to mark the block dirty ourselves.  */
731   if (!DEBUG_INSN_P (DF_REF_INSN (ref)))
732     df_set_bb_dirty (bb);
733 }
734 
735 
736 
737 /*----------------------------------------------------------------------------
738    UTILITIES TO CREATE AND DESTROY REFS AND CHAINS.
739 ----------------------------------------------------------------------------*/
740 
741 static void
742 df_free_ref (df_ref ref)
743 {
744   struct df_scan_problem_data *problem_data
745     = (struct df_scan_problem_data *) df_scan->problem_data;
746 
747   switch (DF_REF_CLASS (ref))
748     {
749     case DF_REF_BASE:
750       pool_free (problem_data->ref_base_pool, ref);
751       break;
752 
753     case DF_REF_ARTIFICIAL:
754       pool_free (problem_data->ref_artificial_pool, ref);
755       break;
756 
757     case DF_REF_REGULAR:
758       pool_free (problem_data->ref_regular_pool, ref);
759       break;
760     }
761 }
762 
763 
764 /* Unlink and delete REF at the reg_use, reg_eq_use or reg_def chain.
765    Also delete the def-use or use-def chain if it exists.  */
766 
767 static void
768 df_reg_chain_unlink (df_ref ref)
769 {
770   df_ref next = DF_REF_NEXT_REG (ref);
771   df_ref prev = DF_REF_PREV_REG (ref);
772   int id = DF_REF_ID (ref);
773   struct df_reg_info *reg_info;
774   df_ref *refs = NULL;
775 
776   if (DF_REF_REG_DEF_P (ref))
777     {
778       int regno = DF_REF_REGNO (ref);
779       reg_info = DF_REG_DEF_GET (regno);
780       refs = df->def_info.refs;
781     }
782   else
783     {
784       if (DF_REF_FLAGS (ref) & DF_REF_IN_NOTE)
785 	{
786 	  reg_info = DF_REG_EQ_USE_GET (DF_REF_REGNO (ref));
787 	  switch (df->use_info.ref_order)
788 	    {
789 	    case DF_REF_ORDER_UNORDERED_WITH_NOTES:
790 	    case DF_REF_ORDER_BY_REG_WITH_NOTES:
791 	    case DF_REF_ORDER_BY_INSN_WITH_NOTES:
792 	      refs = df->use_info.refs;
793 	      break;
794 	    default:
795 	      break;
796 	    }
797 	}
798       else
799 	{
800 	  reg_info = DF_REG_USE_GET (DF_REF_REGNO (ref));
801 	  refs = df->use_info.refs;
802 	}
803     }
804 
805   if (refs)
806     {
807       if (df->analyze_subset)
808 	{
809 	  if (bitmap_bit_p (df->blocks_to_analyze, DF_REF_BBNO (ref)))
810 	    refs[id] = NULL;
811 	}
812       else
813 	refs[id] = NULL;
814     }
815 
816   /* Delete any def-use or use-def chains that start here. It is
817      possible that there is trash in this field.  This happens for
818      insns that have been deleted when rescanning has been deferred
819      and the chain problem has also been deleted.  The chain tear down
820      code skips deleted insns.  */
821   if (df_chain && DF_REF_CHAIN (ref))
822     df_chain_unlink (ref);
823 
824   reg_info->n_refs--;
825   if (DF_REF_FLAGS_IS_SET (ref, DF_HARD_REG_LIVE))
826     {
827       gcc_assert (DF_REF_REGNO (ref) < FIRST_PSEUDO_REGISTER);
828       df->hard_regs_live_count[DF_REF_REGNO (ref)]--;
829     }
830 
831   /* Unlink from the reg chain.  If there is no prev, this is the
832      first of the list.  If not, just join the next and prev.  */
833   if (prev)
834     DF_REF_NEXT_REG (prev) = next;
835   else
836     {
837       gcc_assert (reg_info->reg_chain == ref);
838       reg_info->reg_chain = next;
839     }
840   if (next)
841     DF_REF_PREV_REG (next) = prev;
842 
843   df_free_ref (ref);
844 }
845 
846 
847 /* Create the insn record for INSN.  If there was one there, zero it
848    out.  */
849 
850 struct df_insn_info *
851 df_insn_create_insn_record (rtx_insn *insn)
852 {
853   struct df_scan_problem_data *problem_data
854     = (struct df_scan_problem_data *) df_scan->problem_data;
855   struct df_insn_info *insn_rec;
856 
857   df_grow_insn_info ();
858   insn_rec = DF_INSN_INFO_GET (insn);
859   if (!insn_rec)
860     {
861       insn_rec = (struct df_insn_info *) pool_alloc (problem_data->insn_pool);
862       DF_INSN_INFO_SET (insn, insn_rec);
863     }
864   memset (insn_rec, 0, sizeof (struct df_insn_info));
865   insn_rec->insn = insn;
866   return insn_rec;
867 }
868 
869 
870 /* Delete all du chain (DF_REF_CHAIN()) of all refs in the ref chain.  */
871 
872 static void
873 df_ref_chain_delete_du_chain (df_ref ref)
874 {
875   for (; ref; ref = DF_REF_NEXT_LOC (ref))
876     /* CHAIN is allocated by DF_CHAIN. So make sure to
877        pass df_scan instance for the problem.  */
878     if (DF_REF_CHAIN (ref))
879       df_chain_unlink (ref);
880 }
881 
882 
883 /* Delete all refs in the ref chain.  */
884 
885 static void
886 df_ref_chain_delete (df_ref ref)
887 {
888   df_ref next;
889   for (; ref; ref = next)
890     {
891       next = DF_REF_NEXT_LOC (ref);
892       df_reg_chain_unlink (ref);
893     }
894 }
895 
896 
897 /* Delete the hardreg chain.  */
898 
899 static void
900 df_mw_hardreg_chain_delete (struct df_mw_hardreg *hardregs)
901 {
902   struct df_scan_problem_data *problem_data
903     = (struct df_scan_problem_data *) df_scan->problem_data;
904   df_mw_hardreg *next;
905 
906   for (; hardregs; hardregs = next)
907     {
908       next = DF_MWS_NEXT (hardregs);
909       pool_free (problem_data->mw_reg_pool, hardregs);
910     }
911 }
912 
913 
914 /* Delete all of the refs information from the insn with UID.
915    Internal helper for df_insn_delete, df_insn_rescan, and other
916    df-scan routines that don't have to work in deferred mode
917    and do not have to mark basic blocks for re-processing.  */
918 
919 static void
920 df_insn_info_delete (unsigned int uid)
921 {
922   struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
923 
924   bitmap_clear_bit (&df->insns_to_delete, uid);
925   bitmap_clear_bit (&df->insns_to_rescan, uid);
926   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
927   if (insn_info)
928     {
929       struct df_scan_problem_data *problem_data
930 	= (struct df_scan_problem_data *) df_scan->problem_data;
931 
932       /* In general, notes do not have the insn_info fields
933 	 initialized.  However, combine deletes insns by changing them
934 	 to notes.  How clever.  So we cannot just check if it is a
935 	 valid insn before short circuiting this code, we need to see
936 	 if we actually initialized it.  */
937       df_mw_hardreg_chain_delete (insn_info->mw_hardregs);
938 
939       if (df_chain)
940 	{
941 	  df_ref_chain_delete_du_chain (insn_info->defs);
942 	  df_ref_chain_delete_du_chain (insn_info->uses);
943 	  df_ref_chain_delete_du_chain (insn_info->eq_uses);
944 	}
945 
946       df_ref_chain_delete (insn_info->defs);
947       df_ref_chain_delete (insn_info->uses);
948       df_ref_chain_delete (insn_info->eq_uses);
949 
950       pool_free (problem_data->insn_pool, insn_info);
951       DF_INSN_UID_SET (uid, NULL);
952     }
953 }
954 
955 /* Delete all of the refs information from INSN, either right now
956    or marked for later in deferred mode.  */
957 
958 void
959 df_insn_delete (rtx_insn *insn)
960 {
961   unsigned int uid;
962   basic_block bb;
963 
964   gcc_checking_assert (INSN_P (insn));
965 
966   if (!df)
967     return;
968 
969   uid = INSN_UID (insn);
970   bb = BLOCK_FOR_INSN (insn);
971 
972   /* ??? bb can be NULL after pass_free_cfg.  At that point, DF should
973      not exist anymore (as mentioned in df-core.c: "The only requirement
974      [for DF] is that there be a correct control flow graph."  Clearly
975      that isn't the case after pass_free_cfg.  But DF is freed much later
976      because some back-ends want to use DF info even though the CFG is
977      already gone.  It's not clear to me whether that is safe, actually.
978      In any case, we expect BB to be non-NULL at least up to register
979      allocation, so disallow a non-NULL BB up to there.  Not perfect
980      but better than nothing...  */
981   gcc_checking_assert (bb != NULL || reload_completed);
982 
983   df_grow_bb_info (df_scan);
984   df_grow_reg_info ();
985 
986   /* The block must be marked as dirty now, rather than later as in
987      df_insn_rescan and df_notes_rescan because it may not be there at
988      rescanning time and the mark would blow up.
989      DEBUG_INSNs do not make a block's data flow solution dirty (at
990      worst the LUIDs are no longer contiguous).  */
991   if (bb != NULL && NONDEBUG_INSN_P (insn))
992     df_set_bb_dirty (bb);
993 
994   /* The client has deferred rescanning.  */
995   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
996     {
997       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
998       if (insn_info)
999 	{
1000 	  bitmap_clear_bit (&df->insns_to_rescan, uid);
1001 	  bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1002 	  bitmap_set_bit (&df->insns_to_delete, uid);
1003 	}
1004       if (dump_file)
1005 	fprintf (dump_file, "deferring deletion of insn with uid = %d.\n", uid);
1006       return;
1007     }
1008 
1009   if (dump_file)
1010     fprintf (dump_file, "deleting insn with uid = %d.\n", uid);
1011 
1012   df_insn_info_delete (uid);
1013 }
1014 
1015 
1016 /* Free all of the refs and the mw_hardregs in COLLECTION_REC.  */
1017 
1018 static void
1019 df_free_collection_rec (struct df_collection_rec *collection_rec)
1020 {
1021   unsigned int ix;
1022   struct df_scan_problem_data *problem_data
1023     = (struct df_scan_problem_data *) df_scan->problem_data;
1024   df_ref ref;
1025   struct df_mw_hardreg *mw;
1026 
1027   FOR_EACH_VEC_ELT (collection_rec->def_vec, ix, ref)
1028     df_free_ref (ref);
1029   FOR_EACH_VEC_ELT (collection_rec->use_vec, ix, ref)
1030     df_free_ref (ref);
1031   FOR_EACH_VEC_ELT (collection_rec->eq_use_vec, ix, ref)
1032     df_free_ref (ref);
1033   FOR_EACH_VEC_ELT (collection_rec->mw_vec, ix, mw)
1034     pool_free (problem_data->mw_reg_pool, mw);
1035 
1036   collection_rec->def_vec.release ();
1037   collection_rec->use_vec.release ();
1038   collection_rec->eq_use_vec.release ();
1039   collection_rec->mw_vec.release ();
1040 }
1041 
1042 /* Rescan INSN.  Return TRUE if the rescanning produced any changes.  */
1043 
1044 bool
1045 df_insn_rescan (rtx_insn *insn)
1046 {
1047   unsigned int uid = INSN_UID (insn);
1048   struct df_insn_info *insn_info = NULL;
1049   basic_block bb = BLOCK_FOR_INSN (insn);
1050   struct df_collection_rec collection_rec;
1051 
1052   if ((!df) || (!INSN_P (insn)))
1053     return false;
1054 
1055   if (!bb)
1056     {
1057       if (dump_file)
1058 	fprintf (dump_file, "no bb for insn with uid = %d.\n", uid);
1059       return false;
1060     }
1061 
1062   /* The client has disabled rescanning and plans to do it itself.  */
1063   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1064     return false;
1065 
1066   df_grow_bb_info (df_scan);
1067   df_grow_reg_info ();
1068 
1069   insn_info = DF_INSN_UID_SAFE_GET (uid);
1070 
1071   /* The client has deferred rescanning.  */
1072   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1073     {
1074       if (!insn_info)
1075 	{
1076 	  insn_info = df_insn_create_insn_record (insn);
1077 	  insn_info->defs = 0;
1078 	  insn_info->uses = 0;
1079 	  insn_info->eq_uses = 0;
1080 	  insn_info->mw_hardregs = 0;
1081 	}
1082       if (dump_file)
1083 	fprintf (dump_file, "deferring rescan insn with uid = %d.\n", uid);
1084 
1085       bitmap_clear_bit (&df->insns_to_delete, uid);
1086       bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1087       bitmap_set_bit (&df->insns_to_rescan, INSN_UID (insn));
1088       return false;
1089     }
1090 
1091   bitmap_clear_bit (&df->insns_to_delete, uid);
1092   bitmap_clear_bit (&df->insns_to_rescan, uid);
1093   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1094   if (insn_info)
1095     {
1096       int luid;
1097       bool the_same = df_insn_refs_verify (&collection_rec, bb, insn, false);
1098       /* If there's no change, return false. */
1099       if (the_same)
1100 	{
1101 	  df_free_collection_rec (&collection_rec);
1102 	  if (dump_file)
1103 	    fprintf (dump_file, "verify found no changes in insn with uid = %d.\n", uid);
1104 	  return false;
1105 	}
1106       if (dump_file)
1107 	fprintf (dump_file, "rescanning insn with uid = %d.\n", uid);
1108 
1109       /* There's change - we need to delete the existing info.
1110 	 Since the insn isn't moved, we can salvage its LUID.  */
1111       luid = DF_INSN_LUID (insn);
1112       df_insn_info_delete (uid);
1113       df_insn_create_insn_record (insn);
1114       DF_INSN_LUID (insn) = luid;
1115     }
1116   else
1117     {
1118       struct df_insn_info *insn_info = df_insn_create_insn_record (insn);
1119       df_insn_refs_collect (&collection_rec, bb, insn_info);
1120       if (dump_file)
1121 	fprintf (dump_file, "scanning new insn with uid = %d.\n", uid);
1122     }
1123 
1124   df_refs_add_to_chains (&collection_rec, bb, insn, copy_all);
1125   if (!DEBUG_INSN_P (insn))
1126     df_set_bb_dirty (bb);
1127 
1128   return true;
1129 }
1130 
1131 /* Same as df_insn_rescan, but don't mark the basic block as
1132    dirty.  */
1133 
1134 bool
1135 df_insn_rescan_debug_internal (rtx_insn *insn)
1136 {
1137   unsigned int uid = INSN_UID (insn);
1138   struct df_insn_info *insn_info;
1139 
1140   gcc_assert (DEBUG_INSN_P (insn)
1141 	      && VAR_LOC_UNKNOWN_P (INSN_VAR_LOCATION_LOC (insn)));
1142 
1143   if (!df)
1144     return false;
1145 
1146   insn_info = DF_INSN_UID_SAFE_GET (INSN_UID (insn));
1147   if (!insn_info)
1148     return false;
1149 
1150   if (dump_file)
1151     fprintf (dump_file, "deleting debug_insn with uid = %d.\n", uid);
1152 
1153   bitmap_clear_bit (&df->insns_to_delete, uid);
1154   bitmap_clear_bit (&df->insns_to_rescan, uid);
1155   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1156 
1157   if (insn_info->defs == 0
1158       && insn_info->uses == 0
1159       && insn_info->eq_uses == 0
1160       && insn_info->mw_hardregs == 0)
1161     return false;
1162 
1163   df_mw_hardreg_chain_delete (insn_info->mw_hardregs);
1164 
1165   if (df_chain)
1166     {
1167       df_ref_chain_delete_du_chain (insn_info->defs);
1168       df_ref_chain_delete_du_chain (insn_info->uses);
1169       df_ref_chain_delete_du_chain (insn_info->eq_uses);
1170     }
1171 
1172   df_ref_chain_delete (insn_info->defs);
1173   df_ref_chain_delete (insn_info->uses);
1174   df_ref_chain_delete (insn_info->eq_uses);
1175 
1176   insn_info->defs = 0;
1177   insn_info->uses = 0;
1178   insn_info->eq_uses = 0;
1179   insn_info->mw_hardregs = 0;
1180 
1181   return true;
1182 }
1183 
1184 
1185 /* Rescan all of the insns in the function.  Note that the artificial
1186    uses and defs are not touched.  This function will destroy def-use
1187    or use-def chains.  */
1188 
1189 void
1190 df_insn_rescan_all (void)
1191 {
1192   bool no_insn_rescan = false;
1193   bool defer_insn_rescan = false;
1194   basic_block bb;
1195   bitmap_iterator bi;
1196   unsigned int uid;
1197   bitmap_head tmp;
1198 
1199   bitmap_initialize (&tmp, &df_bitmap_obstack);
1200 
1201   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1202     {
1203       df_clear_flags (DF_NO_INSN_RESCAN);
1204       no_insn_rescan = true;
1205     }
1206 
1207   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1208     {
1209       df_clear_flags (DF_DEFER_INSN_RESCAN);
1210       defer_insn_rescan = true;
1211     }
1212 
1213   bitmap_copy (&tmp, &df->insns_to_delete);
1214   EXECUTE_IF_SET_IN_BITMAP (&tmp, 0, uid, bi)
1215     {
1216       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1217       if (insn_info)
1218 	df_insn_info_delete (uid);
1219     }
1220 
1221   bitmap_clear (&tmp);
1222   bitmap_clear (&df->insns_to_delete);
1223   bitmap_clear (&df->insns_to_rescan);
1224   bitmap_clear (&df->insns_to_notes_rescan);
1225 
1226   FOR_EACH_BB_FN (bb, cfun)
1227     {
1228       rtx_insn *insn;
1229       FOR_BB_INSNS (bb, insn)
1230 	{
1231 	  df_insn_rescan (insn);
1232 	}
1233     }
1234 
1235   if (no_insn_rescan)
1236     df_set_flags (DF_NO_INSN_RESCAN);
1237   if (defer_insn_rescan)
1238     df_set_flags (DF_DEFER_INSN_RESCAN);
1239 }
1240 
1241 
1242 /* Process all of the deferred rescans or deletions.  */
1243 
1244 void
1245 df_process_deferred_rescans (void)
1246 {
1247   bool no_insn_rescan = false;
1248   bool defer_insn_rescan = false;
1249   bitmap_iterator bi;
1250   unsigned int uid;
1251   bitmap_head tmp;
1252 
1253   bitmap_initialize (&tmp, &df_bitmap_obstack);
1254 
1255   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1256     {
1257       df_clear_flags (DF_NO_INSN_RESCAN);
1258       no_insn_rescan = true;
1259     }
1260 
1261   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1262     {
1263       df_clear_flags (DF_DEFER_INSN_RESCAN);
1264       defer_insn_rescan = true;
1265     }
1266 
1267   if (dump_file)
1268     fprintf (dump_file, "starting the processing of deferred insns\n");
1269 
1270   bitmap_copy (&tmp, &df->insns_to_delete);
1271   EXECUTE_IF_SET_IN_BITMAP (&tmp, 0, uid, bi)
1272     {
1273       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1274       if (insn_info)
1275 	df_insn_info_delete (uid);
1276     }
1277 
1278   bitmap_copy (&tmp, &df->insns_to_rescan);
1279   EXECUTE_IF_SET_IN_BITMAP (&tmp, 0, uid, bi)
1280     {
1281       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1282       if (insn_info)
1283 	df_insn_rescan (insn_info->insn);
1284     }
1285 
1286   bitmap_copy (&tmp, &df->insns_to_notes_rescan);
1287   EXECUTE_IF_SET_IN_BITMAP (&tmp, 0, uid, bi)
1288     {
1289       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1290       if (insn_info)
1291 	df_notes_rescan (insn_info->insn);
1292     }
1293 
1294   if (dump_file)
1295     fprintf (dump_file, "ending the processing of deferred insns\n");
1296 
1297   bitmap_clear (&tmp);
1298   bitmap_clear (&df->insns_to_delete);
1299   bitmap_clear (&df->insns_to_rescan);
1300   bitmap_clear (&df->insns_to_notes_rescan);
1301 
1302   if (no_insn_rescan)
1303     df_set_flags (DF_NO_INSN_RESCAN);
1304   if (defer_insn_rescan)
1305     df_set_flags (DF_DEFER_INSN_RESCAN);
1306 
1307   /* If someone changed regs_ever_live during this pass, fix up the
1308      entry and exit blocks.  */
1309   if (df->redo_entry_and_exit)
1310     {
1311       df_update_entry_exit_and_calls ();
1312       df->redo_entry_and_exit = false;
1313     }
1314 }
1315 
1316 
1317 /* Count the number of refs. Include the defs if INCLUDE_DEFS. Include
1318    the uses if INCLUDE_USES. Include the eq_uses if
1319    INCLUDE_EQ_USES.  */
1320 
1321 static unsigned int
1322 df_count_refs (bool include_defs, bool include_uses,
1323 	       bool include_eq_uses)
1324 {
1325   unsigned int regno;
1326   int size = 0;
1327   unsigned int m = df->regs_inited;
1328 
1329   for (regno = 0; regno < m; regno++)
1330     {
1331       if (include_defs)
1332 	size += DF_REG_DEF_COUNT (regno);
1333       if (include_uses)
1334 	size += DF_REG_USE_COUNT (regno);
1335       if (include_eq_uses)
1336 	size += DF_REG_EQ_USE_COUNT (regno);
1337     }
1338   return size;
1339 }
1340 
1341 
1342 /* Take build ref table for either the uses or defs from the reg-use
1343    or reg-def chains.  This version processes the refs in reg order
1344    which is likely to be best if processing the whole function.  */
1345 
1346 static void
1347 df_reorganize_refs_by_reg_by_reg (struct df_ref_info *ref_info,
1348 				  bool include_defs,
1349 				  bool include_uses,
1350 				  bool include_eq_uses)
1351 {
1352   unsigned int m = df->regs_inited;
1353   unsigned int regno;
1354   unsigned int offset = 0;
1355   unsigned int start;
1356 
1357   if (df->changeable_flags & DF_NO_HARD_REGS)
1358     {
1359       start = FIRST_PSEUDO_REGISTER;
1360       memset (ref_info->begin, 0, sizeof (int) * FIRST_PSEUDO_REGISTER);
1361       memset (ref_info->count, 0, sizeof (int) * FIRST_PSEUDO_REGISTER);
1362     }
1363   else
1364     start = 0;
1365 
1366   ref_info->total_size
1367     = df_count_refs (include_defs, include_uses, include_eq_uses);
1368 
1369   df_check_and_grow_ref_info (ref_info, 1);
1370 
1371   for (regno = start; regno < m; regno++)
1372     {
1373       int count = 0;
1374       ref_info->begin[regno] = offset;
1375       if (include_defs)
1376 	{
1377 	  df_ref ref = DF_REG_DEF_CHAIN (regno);
1378 	  while (ref)
1379 	    {
1380 	      ref_info->refs[offset] = ref;
1381 	      DF_REF_ID (ref) = offset++;
1382 	      count++;
1383 	      ref = DF_REF_NEXT_REG (ref);
1384 	      gcc_checking_assert (offset < ref_info->refs_size);
1385 	    }
1386 	}
1387       if (include_uses)
1388 	{
1389 	  df_ref ref = DF_REG_USE_CHAIN (regno);
1390 	  while (ref)
1391 	    {
1392 	      ref_info->refs[offset] = ref;
1393 	      DF_REF_ID (ref) = offset++;
1394 	      count++;
1395 	      ref = DF_REF_NEXT_REG (ref);
1396 	      gcc_checking_assert (offset < ref_info->refs_size);
1397 	    }
1398 	}
1399       if (include_eq_uses)
1400 	{
1401 	  df_ref ref = DF_REG_EQ_USE_CHAIN (regno);
1402 	  while (ref)
1403 	    {
1404 	      ref_info->refs[offset] = ref;
1405 	      DF_REF_ID (ref) = offset++;
1406 	      count++;
1407 	      ref = DF_REF_NEXT_REG (ref);
1408 	      gcc_checking_assert (offset < ref_info->refs_size);
1409 	    }
1410 	}
1411       ref_info->count[regno] = count;
1412     }
1413 
1414   /* The bitmap size is not decremented when refs are deleted.  So
1415      reset it now that we have squished out all of the empty
1416      slots.  */
1417   ref_info->table_size = offset;
1418 }
1419 
1420 
1421 /* Take build ref table for either the uses or defs from the reg-use
1422    or reg-def chains.  This version processes the refs in insn order
1423    which is likely to be best if processing some segment of the
1424    function.  */
1425 
1426 static void
1427 df_reorganize_refs_by_reg_by_insn (struct df_ref_info *ref_info,
1428 				   bool include_defs,
1429 				   bool include_uses,
1430 				   bool include_eq_uses)
1431 {
1432   bitmap_iterator bi;
1433   unsigned int bb_index;
1434   unsigned int m = df->regs_inited;
1435   unsigned int offset = 0;
1436   unsigned int r;
1437   unsigned int start
1438     = (df->changeable_flags & DF_NO_HARD_REGS) ? FIRST_PSEUDO_REGISTER : 0;
1439 
1440   memset (ref_info->begin, 0, sizeof (int) * df->regs_inited);
1441   memset (ref_info->count, 0, sizeof (int) * df->regs_inited);
1442 
1443   ref_info->total_size = df_count_refs (include_defs, include_uses, include_eq_uses);
1444   df_check_and_grow_ref_info (ref_info, 1);
1445 
1446   EXECUTE_IF_SET_IN_BITMAP (df->blocks_to_analyze, 0, bb_index, bi)
1447     {
1448       basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
1449       rtx_insn *insn;
1450       df_ref def, use;
1451 
1452       if (include_defs)
1453 	FOR_EACH_ARTIFICIAL_DEF (def, bb_index)
1454 	  {
1455 	    unsigned int regno = DF_REF_REGNO (def);
1456 	    ref_info->count[regno]++;
1457 	  }
1458       if (include_uses)
1459 	FOR_EACH_ARTIFICIAL_USE (use, bb_index)
1460 	  {
1461 	    unsigned int regno = DF_REF_REGNO (use);
1462 	    ref_info->count[regno]++;
1463 	  }
1464 
1465       FOR_BB_INSNS (bb, insn)
1466 	{
1467 	  if (INSN_P (insn))
1468 	    {
1469 	      struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
1470 
1471 	      if (include_defs)
1472 		FOR_EACH_INSN_INFO_DEF (def, insn_info)
1473 		  {
1474 		    unsigned int regno = DF_REF_REGNO (def);
1475 		    ref_info->count[regno]++;
1476 		  }
1477 	      if (include_uses)
1478 		FOR_EACH_INSN_INFO_USE (use, insn_info)
1479 		  {
1480 		    unsigned int regno = DF_REF_REGNO (use);
1481 		    ref_info->count[regno]++;
1482 		  }
1483 	      if (include_eq_uses)
1484 		FOR_EACH_INSN_INFO_EQ_USE (use, insn_info)
1485 		  {
1486 		    unsigned int regno = DF_REF_REGNO (use);
1487 		    ref_info->count[regno]++;
1488 		  }
1489 	    }
1490 	}
1491     }
1492 
1493   for (r = start; r < m; r++)
1494     {
1495       ref_info->begin[r] = offset;
1496       offset += ref_info->count[r];
1497       ref_info->count[r] = 0;
1498     }
1499 
1500   EXECUTE_IF_SET_IN_BITMAP (df->blocks_to_analyze, 0, bb_index, bi)
1501     {
1502       basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
1503       rtx_insn *insn;
1504       df_ref def, use;
1505 
1506       if (include_defs)
1507 	FOR_EACH_ARTIFICIAL_DEF (def, bb_index)
1508 	  {
1509 	    unsigned int regno = DF_REF_REGNO (def);
1510 	    if (regno >= start)
1511 	      {
1512 		unsigned int id
1513 		  = ref_info->begin[regno] + ref_info->count[regno]++;
1514 		DF_REF_ID (def) = id;
1515 		ref_info->refs[id] = def;
1516 	      }
1517 	  }
1518       if (include_uses)
1519 	FOR_EACH_ARTIFICIAL_USE (use, bb_index)
1520 	  {
1521 	    unsigned int regno = DF_REF_REGNO (def);
1522 	    if (regno >= start)
1523 	      {
1524 		unsigned int id
1525 		  = ref_info->begin[regno] + ref_info->count[regno]++;
1526 		DF_REF_ID (use) = id;
1527 		ref_info->refs[id] = use;
1528 	      }
1529 	  }
1530 
1531       FOR_BB_INSNS (bb, insn)
1532 	{
1533 	  if (INSN_P (insn))
1534 	    {
1535 	      struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
1536 
1537 	      if (include_defs)
1538 		FOR_EACH_INSN_INFO_DEF (def, insn_info)
1539 		  {
1540 		    unsigned int regno = DF_REF_REGNO (def);
1541 		    if (regno >= start)
1542 		      {
1543 			unsigned int id
1544 			  = ref_info->begin[regno] + ref_info->count[regno]++;
1545 			DF_REF_ID (def) = id;
1546 			ref_info->refs[id] = def;
1547 		      }
1548 		  }
1549 	      if (include_uses)
1550 		FOR_EACH_INSN_INFO_USE (use, insn_info)
1551 		  {
1552 		    unsigned int regno = DF_REF_REGNO (use);
1553 		    if (regno >= start)
1554 		      {
1555 			unsigned int id
1556 			  = ref_info->begin[regno] + ref_info->count[regno]++;
1557 			DF_REF_ID (use) = id;
1558 			ref_info->refs[id] = use;
1559 		      }
1560 		  }
1561 	      if (include_eq_uses)
1562 		FOR_EACH_INSN_INFO_EQ_USE (use, insn_info)
1563 		  {
1564 		    unsigned int regno = DF_REF_REGNO (use);
1565 		    if (regno >= start)
1566 		      {
1567 			unsigned int id
1568 			  = ref_info->begin[regno] + ref_info->count[regno]++;
1569 			DF_REF_ID (use) = id;
1570 			ref_info->refs[id] = use;
1571 		      }
1572 		  }
1573 	    }
1574 	}
1575     }
1576 
1577   /* The bitmap size is not decremented when refs are deleted.  So
1578      reset it now that we have squished out all of the empty
1579      slots.  */
1580 
1581   ref_info->table_size = offset;
1582 }
1583 
1584 /* Take build ref table for either the uses or defs from the reg-use
1585    or reg-def chains.  */
1586 
1587 static void
1588 df_reorganize_refs_by_reg (struct df_ref_info *ref_info,
1589 			   bool include_defs,
1590 			   bool include_uses,
1591 			   bool include_eq_uses)
1592 {
1593   if (df->analyze_subset)
1594     df_reorganize_refs_by_reg_by_insn (ref_info, include_defs,
1595 				       include_uses, include_eq_uses);
1596   else
1597     df_reorganize_refs_by_reg_by_reg (ref_info, include_defs,
1598 				       include_uses, include_eq_uses);
1599 }
1600 
1601 
1602 /* Add the refs in REF_VEC to the table in REF_INFO starting at OFFSET.  */
1603 static unsigned int
1604 df_add_refs_to_table (unsigned int offset,
1605 		      struct df_ref_info *ref_info,
1606 		      df_ref ref)
1607 {
1608   for (; ref; ref = DF_REF_NEXT_LOC (ref))
1609     if (!(df->changeable_flags & DF_NO_HARD_REGS)
1610 	|| (DF_REF_REGNO (ref) >= FIRST_PSEUDO_REGISTER))
1611       {
1612 	ref_info->refs[offset] = ref;
1613 	DF_REF_ID (ref) = offset++;
1614       }
1615   return offset;
1616 }
1617 
1618 
1619 /* Count the number of refs in all of the insns of BB. Include the
1620    defs if INCLUDE_DEFS. Include the uses if INCLUDE_USES. Include the
1621    eq_uses if INCLUDE_EQ_USES.  */
1622 
1623 static unsigned int
1624 df_reorganize_refs_by_insn_bb (basic_block bb, unsigned int offset,
1625 			       struct df_ref_info *ref_info,
1626 			       bool include_defs, bool include_uses,
1627 			       bool include_eq_uses)
1628 {
1629   rtx_insn *insn;
1630 
1631   if (include_defs)
1632     offset = df_add_refs_to_table (offset, ref_info,
1633 				   df_get_artificial_defs (bb->index));
1634   if (include_uses)
1635     offset = df_add_refs_to_table (offset, ref_info,
1636 				   df_get_artificial_uses (bb->index));
1637 
1638   FOR_BB_INSNS (bb, insn)
1639     if (INSN_P (insn))
1640       {
1641 	unsigned int uid = INSN_UID (insn);
1642 	if (include_defs)
1643 	  offset = df_add_refs_to_table (offset, ref_info,
1644 					 DF_INSN_UID_DEFS (uid));
1645 	if (include_uses)
1646 	  offset = df_add_refs_to_table (offset, ref_info,
1647 					 DF_INSN_UID_USES (uid));
1648 	if (include_eq_uses)
1649 	  offset = df_add_refs_to_table (offset, ref_info,
1650 					 DF_INSN_UID_EQ_USES (uid));
1651       }
1652   return offset;
1653 }
1654 
1655 
1656 /* Organize the refs by insn into the table in REF_INFO.  If
1657    blocks_to_analyze is defined, use that set, otherwise the entire
1658    program.  Include the defs if INCLUDE_DEFS. Include the uses if
1659    INCLUDE_USES. Include the eq_uses if INCLUDE_EQ_USES.  */
1660 
1661 static void
1662 df_reorganize_refs_by_insn (struct df_ref_info *ref_info,
1663 			    bool include_defs, bool include_uses,
1664 			    bool include_eq_uses)
1665 {
1666   basic_block bb;
1667   unsigned int offset = 0;
1668 
1669   ref_info->total_size = df_count_refs (include_defs, include_uses, include_eq_uses);
1670   df_check_and_grow_ref_info (ref_info, 1);
1671   if (df->blocks_to_analyze)
1672     {
1673       bitmap_iterator bi;
1674       unsigned int index;
1675 
1676       EXECUTE_IF_SET_IN_BITMAP (df->blocks_to_analyze, 0, index, bi)
1677 	{
1678 	  offset = df_reorganize_refs_by_insn_bb (BASIC_BLOCK_FOR_FN (cfun,
1679 								      index),
1680 						  offset, ref_info,
1681 						  include_defs, include_uses,
1682 						  include_eq_uses);
1683 	}
1684 
1685       ref_info->table_size = offset;
1686     }
1687   else
1688     {
1689       FOR_ALL_BB_FN (bb, cfun)
1690 	offset = df_reorganize_refs_by_insn_bb (bb, offset, ref_info,
1691 						include_defs, include_uses,
1692 						include_eq_uses);
1693       ref_info->table_size = offset;
1694     }
1695 }
1696 
1697 
1698 /* If the use refs in DF are not organized, reorganize them.  */
1699 
1700 void
1701 df_maybe_reorganize_use_refs (enum df_ref_order order)
1702 {
1703   if (order == df->use_info.ref_order)
1704     return;
1705 
1706   switch (order)
1707     {
1708     case DF_REF_ORDER_BY_REG:
1709       df_reorganize_refs_by_reg (&df->use_info, false, true, false);
1710       break;
1711 
1712     case DF_REF_ORDER_BY_REG_WITH_NOTES:
1713       df_reorganize_refs_by_reg (&df->use_info, false, true, true);
1714       break;
1715 
1716     case DF_REF_ORDER_BY_INSN:
1717       df_reorganize_refs_by_insn (&df->use_info, false, true, false);
1718       break;
1719 
1720     case DF_REF_ORDER_BY_INSN_WITH_NOTES:
1721       df_reorganize_refs_by_insn (&df->use_info, false, true, true);
1722       break;
1723 
1724     case DF_REF_ORDER_NO_TABLE:
1725       free (df->use_info.refs);
1726       df->use_info.refs = NULL;
1727       df->use_info.refs_size = 0;
1728       break;
1729 
1730     case DF_REF_ORDER_UNORDERED:
1731     case DF_REF_ORDER_UNORDERED_WITH_NOTES:
1732       gcc_unreachable ();
1733       break;
1734     }
1735 
1736   df->use_info.ref_order = order;
1737 }
1738 
1739 
1740 /* If the def refs in DF are not organized, reorganize them.  */
1741 
1742 void
1743 df_maybe_reorganize_def_refs (enum df_ref_order order)
1744 {
1745   if (order == df->def_info.ref_order)
1746     return;
1747 
1748   switch (order)
1749     {
1750     case DF_REF_ORDER_BY_REG:
1751       df_reorganize_refs_by_reg (&df->def_info, true, false, false);
1752       break;
1753 
1754     case DF_REF_ORDER_BY_INSN:
1755       df_reorganize_refs_by_insn (&df->def_info, true, false, false);
1756       break;
1757 
1758     case DF_REF_ORDER_NO_TABLE:
1759       free (df->def_info.refs);
1760       df->def_info.refs = NULL;
1761       df->def_info.refs_size = 0;
1762       break;
1763 
1764     case DF_REF_ORDER_BY_INSN_WITH_NOTES:
1765     case DF_REF_ORDER_BY_REG_WITH_NOTES:
1766     case DF_REF_ORDER_UNORDERED:
1767     case DF_REF_ORDER_UNORDERED_WITH_NOTES:
1768       gcc_unreachable ();
1769       break;
1770     }
1771 
1772   df->def_info.ref_order = order;
1773 }
1774 
1775 
1776 /* Change all of the basic block references in INSN to use the insn's
1777    current basic block.  This function is called from routines that move
1778    instructions from one block to another.  */
1779 
1780 void
1781 df_insn_change_bb (rtx_insn *insn, basic_block new_bb)
1782 {
1783   basic_block old_bb = BLOCK_FOR_INSN (insn);
1784   struct df_insn_info *insn_info;
1785   unsigned int uid = INSN_UID (insn);
1786 
1787   if (old_bb == new_bb)
1788     return;
1789 
1790   set_block_for_insn (insn, new_bb);
1791 
1792   if (!df)
1793     return;
1794 
1795   if (dump_file)
1796     fprintf (dump_file, "changing bb of uid %d\n", uid);
1797 
1798   insn_info = DF_INSN_UID_SAFE_GET (uid);
1799   if (insn_info == NULL)
1800     {
1801       if (dump_file)
1802 	fprintf (dump_file, "  unscanned insn\n");
1803       df_insn_rescan (insn);
1804       return;
1805     }
1806 
1807   if (!INSN_P (insn))
1808     return;
1809 
1810   df_set_bb_dirty (new_bb);
1811   if (old_bb)
1812     {
1813       if (dump_file)
1814 	fprintf (dump_file, "  from %d to %d\n",
1815 		 old_bb->index, new_bb->index);
1816       df_set_bb_dirty (old_bb);
1817     }
1818   else
1819     if (dump_file)
1820       fprintf (dump_file, "  to %d\n", new_bb->index);
1821 }
1822 
1823 
1824 /* Helper function for df_ref_change_reg_with_loc.  */
1825 
1826 static void
1827 df_ref_change_reg_with_loc_1 (struct df_reg_info *old_df,
1828 			      struct df_reg_info *new_df,
1829 			      int new_regno, rtx loc)
1830 {
1831   df_ref the_ref = old_df->reg_chain;
1832 
1833   while (the_ref)
1834     {
1835       if ((!DF_REF_IS_ARTIFICIAL (the_ref))
1836 	  && DF_REF_LOC (the_ref)
1837 	  && (*DF_REF_LOC (the_ref) == loc))
1838 	{
1839 	  df_ref next_ref = DF_REF_NEXT_REG (the_ref);
1840 	  df_ref prev_ref = DF_REF_PREV_REG (the_ref);
1841 	  df_ref *ref_ptr;
1842 	  struct df_insn_info *insn_info = DF_REF_INSN_INFO (the_ref);
1843 
1844 	  DF_REF_REGNO (the_ref) = new_regno;
1845 	  DF_REF_REG (the_ref) = regno_reg_rtx[new_regno];
1846 
1847 	  /* Pull the_ref out of the old regno chain.  */
1848 	  if (prev_ref)
1849 	    DF_REF_NEXT_REG (prev_ref) = next_ref;
1850 	  else
1851 	    old_df->reg_chain = next_ref;
1852 	  if (next_ref)
1853 	    DF_REF_PREV_REG (next_ref) = prev_ref;
1854 	  old_df->n_refs--;
1855 
1856 	  /* Put the ref into the new regno chain.  */
1857 	  DF_REF_PREV_REG (the_ref) = NULL;
1858 	  DF_REF_NEXT_REG (the_ref) = new_df->reg_chain;
1859 	  if (new_df->reg_chain)
1860 	    DF_REF_PREV_REG (new_df->reg_chain) = the_ref;
1861 	  new_df->reg_chain = the_ref;
1862 	  new_df->n_refs++;
1863 	  if (DF_REF_BB (the_ref))
1864 	    df_set_bb_dirty (DF_REF_BB (the_ref));
1865 
1866 	  /* Need to sort the record again that the ref was in because
1867 	     the regno is a sorting key.  First, find the right
1868 	     record.  */
1869 	  if (DF_REF_REG_DEF_P (the_ref))
1870 	    ref_ptr = &insn_info->defs;
1871 	  else if (DF_REF_FLAGS (the_ref) & DF_REF_IN_NOTE)
1872 	    ref_ptr = &insn_info->eq_uses;
1873 	  else
1874 	    ref_ptr = &insn_info->uses;
1875 	  if (dump_file)
1876 	    fprintf (dump_file, "changing reg in insn %d\n",
1877 		     DF_REF_INSN_UID (the_ref));
1878 
1879 	  /* Stop if we find the current reference or where the reference
1880 	     needs to be.  */
1881 	  while (*ref_ptr != the_ref && df_ref_compare (*ref_ptr, the_ref) < 0)
1882 	    ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
1883 	  if (*ref_ptr != the_ref)
1884 	    {
1885 	      /* The reference needs to be promoted up the list.  */
1886 	      df_ref next = DF_REF_NEXT_LOC (the_ref);
1887 	      DF_REF_NEXT_LOC (the_ref) = *ref_ptr;
1888 	      *ref_ptr = the_ref;
1889 	      do
1890 		ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
1891 	      while (*ref_ptr != the_ref);
1892 	      *ref_ptr = next;
1893 	    }
1894 	  else if (DF_REF_NEXT_LOC (the_ref)
1895 		   && df_ref_compare (the_ref, DF_REF_NEXT_LOC (the_ref)) > 0)
1896 	    {
1897 	      /* The reference needs to be demoted down the list.  */
1898 	      *ref_ptr = DF_REF_NEXT_LOC (the_ref);
1899 	      do
1900 		ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
1901 	      while (*ref_ptr && df_ref_compare (the_ref, *ref_ptr) > 0);
1902 	      DF_REF_NEXT_LOC (the_ref) = *ref_ptr;
1903 	      *ref_ptr = the_ref;
1904 	    }
1905 
1906 	  the_ref = next_ref;
1907 	}
1908       else
1909 	the_ref = DF_REF_NEXT_REG (the_ref);
1910     }
1911 }
1912 
1913 
1914 /* Change the regno of all refs that contained LOC from OLD_REGNO to
1915    NEW_REGNO.  Refs that do not match LOC are not changed which means
1916    that artificial refs are not changed since they have no loc.  This
1917    call is to support the SET_REGNO macro. */
1918 
1919 void
1920 df_ref_change_reg_with_loc (int old_regno, int new_regno, rtx loc)
1921 {
1922   if ((!df) || (old_regno == -1) || (old_regno == new_regno))
1923     return;
1924 
1925   df_grow_reg_info ();
1926 
1927   df_ref_change_reg_with_loc_1 (DF_REG_DEF_GET (old_regno),
1928 				DF_REG_DEF_GET (new_regno), new_regno, loc);
1929   df_ref_change_reg_with_loc_1 (DF_REG_USE_GET (old_regno),
1930 				DF_REG_USE_GET (new_regno), new_regno, loc);
1931   df_ref_change_reg_with_loc_1 (DF_REG_EQ_USE_GET (old_regno),
1932 				DF_REG_EQ_USE_GET (new_regno), new_regno, loc);
1933 }
1934 
1935 
1936 /* Delete the mw_hardregs that point into the eq_notes.  */
1937 
1938 static void
1939 df_mw_hardreg_chain_delete_eq_uses (struct df_insn_info *insn_info)
1940 {
1941   struct df_mw_hardreg **mw_ptr = &insn_info->mw_hardregs;
1942   struct df_scan_problem_data *problem_data
1943     = (struct df_scan_problem_data *) df_scan->problem_data;
1944 
1945   while (*mw_ptr)
1946     {
1947       df_mw_hardreg *mw = *mw_ptr;
1948       if (mw->flags & DF_REF_IN_NOTE)
1949 	{
1950 	  *mw_ptr = DF_MWS_NEXT (mw);
1951 	  pool_free (problem_data->mw_reg_pool, mw);
1952 	}
1953       else
1954 	mw_ptr = &DF_MWS_NEXT (mw);
1955     }
1956 }
1957 
1958 
1959 /* Rescan only the REG_EQUIV/REG_EQUAL notes part of INSN.  */
1960 
1961 void
1962 df_notes_rescan (rtx_insn *insn)
1963 {
1964   struct df_insn_info *insn_info;
1965   unsigned int uid = INSN_UID (insn);
1966 
1967   if (!df)
1968     return;
1969 
1970   /* The client has disabled rescanning and plans to do it itself.  */
1971   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1972     return;
1973 
1974   /* Do nothing if the insn hasn't been emitted yet.  */
1975   if (!BLOCK_FOR_INSN (insn))
1976     return;
1977 
1978   df_grow_bb_info (df_scan);
1979   df_grow_reg_info ();
1980 
1981   insn_info = DF_INSN_UID_SAFE_GET (INSN_UID (insn));
1982 
1983   /* The client has deferred rescanning.  */
1984   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1985     {
1986       if (!insn_info)
1987 	{
1988 	  insn_info = df_insn_create_insn_record (insn);
1989 	  insn_info->defs = 0;
1990 	  insn_info->uses = 0;
1991 	  insn_info->eq_uses = 0;
1992 	  insn_info->mw_hardregs = 0;
1993 	}
1994 
1995       bitmap_clear_bit (&df->insns_to_delete, uid);
1996       /* If the insn is set to be rescanned, it does not need to also
1997 	 be notes rescanned.  */
1998       if (!bitmap_bit_p (&df->insns_to_rescan, uid))
1999 	bitmap_set_bit (&df->insns_to_notes_rescan, INSN_UID (insn));
2000       return;
2001     }
2002 
2003   bitmap_clear_bit (&df->insns_to_delete, uid);
2004   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
2005 
2006   if (insn_info)
2007     {
2008       basic_block bb = BLOCK_FOR_INSN (insn);
2009       rtx note;
2010       struct df_collection_rec collection_rec;
2011       unsigned int i;
2012 
2013       df_mw_hardreg_chain_delete_eq_uses (insn_info);
2014       df_ref_chain_delete (insn_info->eq_uses);
2015       insn_info->eq_uses = NULL;
2016 
2017       /* Process REG_EQUIV/REG_EQUAL notes */
2018       for (note = REG_NOTES (insn); note;
2019 	   note = XEXP (note, 1))
2020 	{
2021 	  switch (REG_NOTE_KIND (note))
2022 	    {
2023 	    case REG_EQUIV:
2024 	    case REG_EQUAL:
2025 	      df_uses_record (&collection_rec,
2026 			      &XEXP (note, 0), DF_REF_REG_USE,
2027 			      bb, insn_info, DF_REF_IN_NOTE);
2028 	    default:
2029 	      break;
2030 	    }
2031 	}
2032 
2033       /* Find some place to put any new mw_hardregs.  */
2034       df_canonize_collection_rec (&collection_rec);
2035       struct df_mw_hardreg **mw_ptr = &insn_info->mw_hardregs, *mw;
2036       FOR_EACH_VEC_ELT (collection_rec.mw_vec, i, mw)
2037 	{
2038 	  while (*mw_ptr && df_mw_compare (*mw_ptr, mw) < 0)
2039 	    mw_ptr = &DF_MWS_NEXT (*mw_ptr);
2040 	  DF_MWS_NEXT (mw) = *mw_ptr;
2041 	  *mw_ptr = mw;
2042 	  mw_ptr = &DF_MWS_NEXT (mw);
2043 	}
2044       df_refs_add_to_chains (&collection_rec, bb, insn, copy_eq_uses);
2045     }
2046   else
2047     df_insn_rescan (insn);
2048 
2049 }
2050 
2051 
2052 /*----------------------------------------------------------------------------
2053    Hard core instruction scanning code.  No external interfaces here,
2054    just a lot of routines that look inside insns.
2055 ----------------------------------------------------------------------------*/
2056 
2057 
2058 /* Return true if the contents of two df_ref's are identical.
2059    It ignores DF_REF_MARKER.  */
2060 
2061 static bool
2062 df_ref_equal_p (df_ref ref1, df_ref ref2)
2063 {
2064   if (!ref2)
2065     return false;
2066 
2067   if (ref1 == ref2)
2068     return true;
2069 
2070   if (DF_REF_CLASS (ref1) != DF_REF_CLASS (ref2)
2071       || DF_REF_REGNO (ref1) != DF_REF_REGNO (ref2)
2072       || DF_REF_REG (ref1) != DF_REF_REG (ref2)
2073       || DF_REF_TYPE (ref1) != DF_REF_TYPE (ref2)
2074       || ((DF_REF_FLAGS (ref1) & ~(DF_REF_REG_MARKER + DF_REF_MW_HARDREG))
2075 	  != (DF_REF_FLAGS (ref2) & ~(DF_REF_REG_MARKER + DF_REF_MW_HARDREG)))
2076       || DF_REF_BB (ref1) != DF_REF_BB (ref2)
2077       || DF_REF_INSN_INFO (ref1) != DF_REF_INSN_INFO (ref2))
2078     return false;
2079 
2080   switch (DF_REF_CLASS (ref1))
2081     {
2082     case DF_REF_ARTIFICIAL:
2083     case DF_REF_BASE:
2084       return true;
2085 
2086     case DF_REF_REGULAR:
2087       return DF_REF_LOC (ref1) == DF_REF_LOC (ref2);
2088 
2089     default:
2090       gcc_unreachable ();
2091     }
2092   return false;
2093 }
2094 
2095 
2096 /* Compare REF1 and REF2 for sorting.  This is only called from places
2097    where all of the refs are of the same type, in the same insn, and
2098    have the same bb.  So these fields are not checked.  */
2099 
2100 static int
2101 df_ref_compare (df_ref ref1, df_ref ref2)
2102 {
2103   if (DF_REF_CLASS (ref1) != DF_REF_CLASS (ref2))
2104     return (int)DF_REF_CLASS (ref1) - (int)DF_REF_CLASS (ref2);
2105 
2106   if (DF_REF_REGNO (ref1) != DF_REF_REGNO (ref2))
2107     return (int)DF_REF_REGNO (ref1) - (int)DF_REF_REGNO (ref2);
2108 
2109   if (DF_REF_TYPE (ref1) != DF_REF_TYPE (ref2))
2110     return (int)DF_REF_TYPE (ref1) - (int)DF_REF_TYPE (ref2);
2111 
2112   if (DF_REF_REG (ref1) != DF_REF_REG (ref2))
2113     return (int)DF_REF_ORDER (ref1) - (int)DF_REF_ORDER (ref2);
2114 
2115   /* Cannot look at the LOC field on artificial refs.  */
2116   if (DF_REF_CLASS (ref1) != DF_REF_ARTIFICIAL
2117       && DF_REF_LOC (ref1) != DF_REF_LOC (ref2))
2118     return (int)DF_REF_ORDER (ref1) - (int)DF_REF_ORDER (ref2);
2119 
2120   if (DF_REF_FLAGS (ref1) != DF_REF_FLAGS (ref2))
2121     {
2122       /* If two refs are identical except that one of them has is from
2123 	 a mw and one is not, we need to have the one with the mw
2124 	 first.  */
2125       if (DF_REF_FLAGS_IS_SET (ref1, DF_REF_MW_HARDREG) ==
2126 	  DF_REF_FLAGS_IS_SET (ref2, DF_REF_MW_HARDREG))
2127 	return DF_REF_FLAGS (ref1) - DF_REF_FLAGS (ref2);
2128       else if (DF_REF_FLAGS_IS_SET (ref1, DF_REF_MW_HARDREG))
2129 	return -1;
2130       else
2131 	return 1;
2132     }
2133 
2134   return (int)DF_REF_ORDER (ref1) - (int)DF_REF_ORDER (ref2);
2135 }
2136 
2137 /* Like df_ref_compare, but compare two df_ref* pointers R1 and R2.  */
2138 
2139 static int
2140 df_ref_ptr_compare (const void *r1, const void *r2)
2141 {
2142   return df_ref_compare (*(const df_ref *) r1, *(const df_ref *) r2);
2143 }
2144 
2145 static void
2146 df_swap_refs (vec<df_ref, va_heap> *ref_vec, int i, int j)
2147 {
2148   df_ref tmp = (*ref_vec)[i];
2149   (*ref_vec)[i] = (*ref_vec)[j];
2150   (*ref_vec)[j] = tmp;
2151 }
2152 
2153 /* Sort and compress a set of refs.  */
2154 
2155 static void
2156 df_sort_and_compress_refs (vec<df_ref, va_heap> *ref_vec)
2157 {
2158   unsigned int count;
2159   unsigned int i;
2160   unsigned int dist = 0;
2161 
2162   count = ref_vec->length ();
2163 
2164   /* If there are 1 or 0 elements, there is nothing to do.  */
2165   if (count < 2)
2166     return;
2167   else if (count == 2)
2168     {
2169       df_ref r0 = (*ref_vec)[0];
2170       df_ref r1 = (*ref_vec)[1];
2171       if (df_ref_compare (r0, r1) > 0)
2172         df_swap_refs (ref_vec, 0, 1);
2173     }
2174   else
2175     {
2176       for (i = 0; i < count - 1; i++)
2177 	{
2178 	  df_ref r0 = (*ref_vec)[i];
2179 	  df_ref r1 = (*ref_vec)[i + 1];
2180 	  if (df_ref_compare (r0, r1) >= 0)
2181 	    break;
2182 	}
2183       /* If the array is already strictly ordered,
2184          which is the most common case for large COUNT case
2185          (which happens for CALL INSNs),
2186          no need to sort and filter out duplicate.
2187          Simply return the count.
2188          Make sure DF_GET_ADD_REFS adds refs in the increasing order
2189          of DF_REF_COMPARE.  */
2190       if (i == count - 1)
2191         return;
2192       ref_vec->qsort (df_ref_ptr_compare);
2193     }
2194 
2195   for (i=0; i<count-dist; i++)
2196     {
2197       /* Find the next ref that is not equal to the current ref.  */
2198       while (i + dist + 1 < count
2199 	     && df_ref_equal_p ((*ref_vec)[i],
2200 				(*ref_vec)[i + dist + 1]))
2201 	{
2202 	  df_free_ref ((*ref_vec)[i + dist + 1]);
2203 	  dist++;
2204 	}
2205       /* Copy it down to the next position.  */
2206       if (dist && i + dist + 1 < count)
2207 	(*ref_vec)[i + 1] = (*ref_vec)[i + dist + 1];
2208     }
2209 
2210   count -= dist;
2211   ref_vec->truncate (count);
2212 }
2213 
2214 
2215 /* Return true if the contents of two df_ref's are identical.
2216    It ignores DF_REF_MARKER.  */
2217 
2218 static bool
2219 df_mw_equal_p (struct df_mw_hardreg *mw1, struct df_mw_hardreg *mw2)
2220 {
2221   if (!mw2)
2222     return false;
2223   return (mw1 == mw2) ||
2224     (mw1->mw_reg == mw2->mw_reg
2225      && mw1->type == mw2->type
2226      && mw1->flags == mw2->flags
2227      && mw1->start_regno == mw2->start_regno
2228      && mw1->end_regno == mw2->end_regno);
2229 }
2230 
2231 
2232 /* Compare MW1 and MW2 for sorting.  */
2233 
2234 static int
2235 df_mw_compare (const df_mw_hardreg *mw1, const df_mw_hardreg *mw2)
2236 {
2237   if (mw1->type != mw2->type)
2238     return mw1->type - mw2->type;
2239 
2240   if (mw1->flags != mw2->flags)
2241     return mw1->flags - mw2->flags;
2242 
2243   if (mw1->start_regno != mw2->start_regno)
2244     return mw1->start_regno - mw2->start_regno;
2245 
2246   if (mw1->end_regno != mw2->end_regno)
2247     return mw1->end_regno - mw2->end_regno;
2248 
2249   if (mw1->mw_reg != mw2->mw_reg)
2250     return mw1->mw_order - mw2->mw_order;
2251 
2252   return 0;
2253 }
2254 
2255 /* Like df_mw_compare, but compare two df_mw_hardreg** pointers R1 and R2.  */
2256 
2257 static int
2258 df_mw_ptr_compare (const void *m1, const void *m2)
2259 {
2260   return df_mw_compare (*(const df_mw_hardreg *const *) m1,
2261 			*(const df_mw_hardreg *const *) m2);
2262 }
2263 
2264 /* Sort and compress a set of refs.  */
2265 
2266 static void
2267 df_sort_and_compress_mws (vec<df_mw_hardreg_ptr, va_heap> *mw_vec)
2268 {
2269   unsigned int count;
2270   struct df_scan_problem_data *problem_data
2271     = (struct df_scan_problem_data *) df_scan->problem_data;
2272   unsigned int i;
2273   unsigned int dist = 0;
2274 
2275   count = mw_vec->length ();
2276   if (count < 2)
2277     return;
2278   else if (count == 2)
2279     {
2280       struct df_mw_hardreg *m0 = (*mw_vec)[0];
2281       struct df_mw_hardreg *m1 = (*mw_vec)[1];
2282       if (df_mw_compare (m0, m1) > 0)
2283         {
2284           struct df_mw_hardreg *tmp = (*mw_vec)[0];
2285 	  (*mw_vec)[0] = (*mw_vec)[1];
2286 	  (*mw_vec)[1] = tmp;
2287         }
2288     }
2289   else
2290     mw_vec->qsort (df_mw_ptr_compare);
2291 
2292   for (i=0; i<count-dist; i++)
2293     {
2294       /* Find the next ref that is not equal to the current ref.  */
2295       while (i + dist + 1 < count
2296 	     && df_mw_equal_p ((*mw_vec)[i], (*mw_vec)[i + dist + 1]))
2297 	{
2298 	  pool_free (problem_data->mw_reg_pool,
2299 		     (*mw_vec)[i + dist + 1]);
2300 	  dist++;
2301 	}
2302       /* Copy it down to the next position.  */
2303       if (dist && i + dist + 1 < count)
2304 	(*mw_vec)[i + 1] = (*mw_vec)[i + dist + 1];
2305     }
2306 
2307   count -= dist;
2308   mw_vec->truncate (count);
2309 }
2310 
2311 
2312 /* Sort and remove duplicates from the COLLECTION_REC.  */
2313 
2314 static void
2315 df_canonize_collection_rec (struct df_collection_rec *collection_rec)
2316 {
2317   df_sort_and_compress_refs (&collection_rec->def_vec);
2318   df_sort_and_compress_refs (&collection_rec->use_vec);
2319   df_sort_and_compress_refs (&collection_rec->eq_use_vec);
2320   df_sort_and_compress_mws (&collection_rec->mw_vec);
2321 }
2322 
2323 
2324 /* Add the new df_ref to appropriate reg_info/ref_info chains.  */
2325 
2326 static void
2327 df_install_ref (df_ref this_ref,
2328 		struct df_reg_info *reg_info,
2329 		struct df_ref_info *ref_info,
2330 		bool add_to_table)
2331 {
2332   unsigned int regno = DF_REF_REGNO (this_ref);
2333   /* Add the ref to the reg_{def,use,eq_use} chain.  */
2334   df_ref head = reg_info->reg_chain;
2335 
2336   reg_info->reg_chain = this_ref;
2337   reg_info->n_refs++;
2338 
2339   if (DF_REF_FLAGS_IS_SET (this_ref, DF_HARD_REG_LIVE))
2340     {
2341       gcc_assert (regno < FIRST_PSEUDO_REGISTER);
2342       df->hard_regs_live_count[regno]++;
2343     }
2344 
2345   gcc_checking_assert (DF_REF_NEXT_REG (this_ref) == NULL
2346 		       && DF_REF_PREV_REG (this_ref) == NULL);
2347 
2348   DF_REF_NEXT_REG (this_ref) = head;
2349 
2350   /* We cannot actually link to the head of the chain.  */
2351   DF_REF_PREV_REG (this_ref) = NULL;
2352 
2353   if (head)
2354     DF_REF_PREV_REG (head) = this_ref;
2355 
2356   if (add_to_table)
2357     {
2358       gcc_assert (ref_info->ref_order != DF_REF_ORDER_NO_TABLE);
2359       df_check_and_grow_ref_info (ref_info, 1);
2360       DF_REF_ID (this_ref) = ref_info->table_size;
2361       /* Add the ref to the big array of defs.  */
2362       ref_info->refs[ref_info->table_size] = this_ref;
2363       ref_info->table_size++;
2364     }
2365   else
2366     DF_REF_ID (this_ref) = -1;
2367 
2368   ref_info->total_size++;
2369 }
2370 
2371 
2372 /* This function takes one of the groups of refs (defs, uses or
2373    eq_uses) and installs the entire group into the insn.  It also adds
2374    each of these refs into the appropriate chains.  */
2375 
2376 static df_ref
2377 df_install_refs (basic_block bb,
2378 		 const vec<df_ref, va_heap> *old_vec,
2379 		 struct df_reg_info **reg_info,
2380 		 struct df_ref_info *ref_info,
2381 		 bool is_notes)
2382 {
2383   unsigned int count = old_vec->length ();
2384   if (count)
2385     {
2386       bool add_to_table;
2387       df_ref this_ref;
2388       unsigned int ix;
2389 
2390       switch (ref_info->ref_order)
2391 	{
2392 	case DF_REF_ORDER_UNORDERED_WITH_NOTES:
2393 	case DF_REF_ORDER_BY_REG_WITH_NOTES:
2394 	case DF_REF_ORDER_BY_INSN_WITH_NOTES:
2395 	  ref_info->ref_order = DF_REF_ORDER_UNORDERED_WITH_NOTES;
2396 	  add_to_table = true;
2397 	  break;
2398 	case DF_REF_ORDER_UNORDERED:
2399 	case DF_REF_ORDER_BY_REG:
2400 	case DF_REF_ORDER_BY_INSN:
2401 	  ref_info->ref_order = DF_REF_ORDER_UNORDERED;
2402 	  add_to_table = !is_notes;
2403 	  break;
2404 	default:
2405 	  add_to_table = false;
2406 	  break;
2407 	}
2408 
2409       /* Do not add if ref is not in the right blocks.  */
2410       if (add_to_table && df->analyze_subset)
2411 	add_to_table = bitmap_bit_p (df->blocks_to_analyze, bb->index);
2412 
2413       FOR_EACH_VEC_ELT (*old_vec, ix, this_ref)
2414 	{
2415 	  DF_REF_NEXT_LOC (this_ref) = (ix + 1 < old_vec->length ()
2416 					? (*old_vec)[ix + 1]
2417 					: NULL);
2418 	  df_install_ref (this_ref, reg_info[DF_REF_REGNO (this_ref)],
2419 			  ref_info, add_to_table);
2420 	}
2421       return (*old_vec)[0];
2422     }
2423   else
2424     return 0;
2425 }
2426 
2427 
2428 /* This function takes the mws installs the entire group into the
2429    insn.  */
2430 
2431 static struct df_mw_hardreg *
2432 df_install_mws (const vec<df_mw_hardreg_ptr, va_heap> *old_vec)
2433 {
2434   unsigned int count = old_vec->length ();
2435   if (count)
2436     {
2437       for (unsigned int i = 0; i < count - 1; i++)
2438 	DF_MWS_NEXT ((*old_vec)[i]) = (*old_vec)[i + 1];
2439       DF_MWS_NEXT ((*old_vec)[count - 1]) = 0;
2440       return (*old_vec)[0];
2441     }
2442   else
2443     return 0;
2444 }
2445 
2446 
2447 /* Add a chain of df_refs to appropriate ref chain/reg_info/ref_info
2448    chains and update other necessary information.  */
2449 
2450 static void
2451 df_refs_add_to_chains (struct df_collection_rec *collection_rec,
2452 		       basic_block bb, rtx_insn *insn, unsigned int flags)
2453 {
2454   if (insn)
2455     {
2456       struct df_insn_info *insn_rec = DF_INSN_INFO_GET (insn);
2457       /* If there is a vector in the collection rec, add it to the
2458 	 insn.  A null rec is a signal that the caller will handle the
2459 	 chain specially.  */
2460       if (flags & copy_defs)
2461 	{
2462 	  gcc_checking_assert (!insn_rec->defs);
2463 	  insn_rec->defs
2464 	    = df_install_refs (bb, &collection_rec->def_vec,
2465 			       df->def_regs,
2466 			       &df->def_info, false);
2467 	}
2468       if (flags & copy_uses)
2469 	{
2470 	  gcc_checking_assert (!insn_rec->uses);
2471 	  insn_rec->uses
2472 	    = df_install_refs (bb, &collection_rec->use_vec,
2473 			       df->use_regs,
2474 			       &df->use_info, false);
2475 	}
2476       if (flags & copy_eq_uses)
2477 	{
2478 	  gcc_checking_assert (!insn_rec->eq_uses);
2479 	  insn_rec->eq_uses
2480 	    = df_install_refs (bb, &collection_rec->eq_use_vec,
2481 			       df->eq_use_regs,
2482 			       &df->use_info, true);
2483 	}
2484       if (flags & copy_mw)
2485 	{
2486 	  gcc_checking_assert (!insn_rec->mw_hardregs);
2487 	  insn_rec->mw_hardregs
2488 	    = df_install_mws (&collection_rec->mw_vec);
2489 	}
2490     }
2491   else
2492     {
2493       struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb->index);
2494 
2495       gcc_checking_assert (!bb_info->artificial_defs);
2496       bb_info->artificial_defs
2497 	= df_install_refs (bb, &collection_rec->def_vec,
2498 			   df->def_regs,
2499 			   &df->def_info, false);
2500       gcc_checking_assert (!bb_info->artificial_uses);
2501       bb_info->artificial_uses
2502 	= df_install_refs (bb, &collection_rec->use_vec,
2503 			   df->use_regs,
2504 			   &df->use_info, false);
2505     }
2506 }
2507 
2508 
2509 /* Allocate a ref and initialize its fields.  */
2510 
2511 static df_ref
2512 df_ref_create_structure (enum df_ref_class cl,
2513 			 struct df_collection_rec *collection_rec,
2514 			 rtx reg, rtx *loc,
2515 			 basic_block bb, struct df_insn_info *info,
2516 			 enum df_ref_type ref_type,
2517 			 int ref_flags)
2518 {
2519   df_ref this_ref = NULL;
2520   int regno = REGNO (GET_CODE (reg) == SUBREG ? SUBREG_REG (reg) : reg);
2521   struct df_scan_problem_data *problem_data
2522     = (struct df_scan_problem_data *) df_scan->problem_data;
2523 
2524   switch (cl)
2525     {
2526     case DF_REF_BASE:
2527       this_ref = (df_ref) pool_alloc (problem_data->ref_base_pool);
2528       gcc_checking_assert (loc == NULL);
2529       break;
2530 
2531     case DF_REF_ARTIFICIAL:
2532       this_ref = (df_ref) pool_alloc (problem_data->ref_artificial_pool);
2533       this_ref->artificial_ref.bb = bb;
2534       gcc_checking_assert (loc == NULL);
2535       break;
2536 
2537     case DF_REF_REGULAR:
2538       this_ref = (df_ref) pool_alloc (problem_data->ref_regular_pool);
2539       this_ref->regular_ref.loc = loc;
2540       gcc_checking_assert (loc);
2541       break;
2542     }
2543 
2544   DF_REF_CLASS (this_ref) = cl;
2545   DF_REF_ID (this_ref) = -1;
2546   DF_REF_REG (this_ref) = reg;
2547   DF_REF_REGNO (this_ref) =  regno;
2548   DF_REF_TYPE (this_ref) = ref_type;
2549   DF_REF_INSN_INFO (this_ref) = info;
2550   DF_REF_CHAIN (this_ref) = NULL;
2551   DF_REF_FLAGS (this_ref) = ref_flags;
2552   DF_REF_NEXT_REG (this_ref) = NULL;
2553   DF_REF_PREV_REG (this_ref) = NULL;
2554   DF_REF_ORDER (this_ref) = df->ref_order++;
2555 
2556   /* We need to clear this bit because fwprop, and in the future
2557      possibly other optimizations sometimes create new refs using ond
2558      refs as the model.  */
2559   DF_REF_FLAGS_CLEAR (this_ref, DF_HARD_REG_LIVE);
2560 
2561   /* See if this ref needs to have DF_HARD_REG_LIVE bit set.  */
2562   if (regno < FIRST_PSEUDO_REGISTER
2563       && !DF_REF_IS_ARTIFICIAL (this_ref)
2564       && !DEBUG_INSN_P (DF_REF_INSN (this_ref)))
2565     {
2566       if (DF_REF_REG_DEF_P (this_ref))
2567 	{
2568 	  if (!DF_REF_FLAGS_IS_SET (this_ref, DF_REF_MAY_CLOBBER))
2569 	    DF_REF_FLAGS_SET (this_ref, DF_HARD_REG_LIVE);
2570 	}
2571       else if (!(TEST_HARD_REG_BIT (elim_reg_set, regno)
2572 		 && (regno == FRAME_POINTER_REGNUM
2573 		     || regno == ARG_POINTER_REGNUM)))
2574 	DF_REF_FLAGS_SET (this_ref, DF_HARD_REG_LIVE);
2575     }
2576 
2577   if (collection_rec)
2578     {
2579       if (DF_REF_REG_DEF_P (this_ref))
2580 	collection_rec->def_vec.safe_push (this_ref);
2581       else if (DF_REF_FLAGS (this_ref) & DF_REF_IN_NOTE)
2582 	collection_rec->eq_use_vec.safe_push (this_ref);
2583       else
2584 	collection_rec->use_vec.safe_push (this_ref);
2585     }
2586   else
2587     df_install_ref_incremental (this_ref);
2588 
2589   return this_ref;
2590 }
2591 
2592 
2593 /* Create new references of type DF_REF_TYPE for each part of register REG
2594    at address LOC within INSN of BB.  */
2595 
2596 
2597 static void
2598 df_ref_record (enum df_ref_class cl,
2599 	       struct df_collection_rec *collection_rec,
2600                rtx reg, rtx *loc,
2601 	       basic_block bb, struct df_insn_info *insn_info,
2602 	       enum df_ref_type ref_type,
2603 	       int ref_flags)
2604 {
2605   unsigned int regno;
2606 
2607   gcc_checking_assert (REG_P (reg) || GET_CODE (reg) == SUBREG);
2608 
2609   regno = REGNO (GET_CODE (reg) == SUBREG ? SUBREG_REG (reg) : reg);
2610   if (regno < FIRST_PSEUDO_REGISTER)
2611     {
2612       struct df_mw_hardreg *hardreg = NULL;
2613       struct df_scan_problem_data *problem_data
2614         = (struct df_scan_problem_data *) df_scan->problem_data;
2615       unsigned int i;
2616       unsigned int endregno;
2617       df_ref ref;
2618 
2619       if (GET_CODE (reg) == SUBREG)
2620 	{
2621 	  regno += subreg_regno_offset (regno, GET_MODE (SUBREG_REG (reg)),
2622 					SUBREG_BYTE (reg), GET_MODE (reg));
2623 	  endregno = regno + subreg_nregs (reg);
2624 	}
2625       else
2626 	endregno = END_HARD_REGNO (reg);
2627 
2628       /*  If this is a multiword hardreg, we create some extra
2629 	  datastructures that will enable us to easily build REG_DEAD
2630 	  and REG_UNUSED notes.  */
2631       if (collection_rec
2632 	  && (endregno != regno + 1) && insn_info)
2633 	{
2634 	  /* Sets to a subreg of a multiword register are partial.
2635 	     Sets to a non-subreg of a multiword register are not.  */
2636 	  if (GET_CODE (reg) == SUBREG)
2637 	    ref_flags |= DF_REF_PARTIAL;
2638 	  ref_flags |= DF_REF_MW_HARDREG;
2639 
2640 	  hardreg = (struct df_mw_hardreg *) pool_alloc (problem_data->mw_reg_pool);
2641 	  hardreg->type = ref_type;
2642 	  hardreg->flags = ref_flags;
2643 	  hardreg->mw_reg = reg;
2644 	  hardreg->start_regno = regno;
2645 	  hardreg->end_regno = endregno - 1;
2646 	  hardreg->mw_order = df->ref_order++;
2647 	  collection_rec->mw_vec.safe_push (hardreg);
2648 	}
2649 
2650       for (i = regno; i < endregno; i++)
2651 	{
2652 	  ref = df_ref_create_structure (cl, collection_rec, regno_reg_rtx[i], loc,
2653 					 bb, insn_info, ref_type, ref_flags);
2654 
2655           gcc_assert (ORIGINAL_REGNO (DF_REF_REG (ref)) == i);
2656 	}
2657     }
2658   else
2659     {
2660       df_ref_create_structure (cl, collection_rec, reg, loc, bb, insn_info,
2661 			       ref_type, ref_flags);
2662     }
2663 }
2664 
2665 
2666 /* A set to a non-paradoxical SUBREG for which the number of word_mode units
2667    covered by the outer mode is smaller than that covered by the inner mode,
2668    is a read-modify-write operation.
2669    This function returns true iff the SUBREG X is such a SUBREG.  */
2670 
2671 bool
2672 df_read_modify_subreg_p (rtx x)
2673 {
2674   unsigned int isize, osize;
2675   if (GET_CODE (x) != SUBREG)
2676     return false;
2677   isize = GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)));
2678   osize = GET_MODE_SIZE (GET_MODE (x));
2679   return isize > osize
2680 	 && isize > REGMODE_NATURAL_SIZE (GET_MODE (SUBREG_REG (x)));
2681 }
2682 
2683 
2684 /* Process all the registers defined in the rtx pointed by LOC.
2685    Autoincrement/decrement definitions will be picked up by df_uses_record.
2686    Any change here has to be matched in df_find_hard_reg_defs_1.  */
2687 
2688 static void
2689 df_def_record_1 (struct df_collection_rec *collection_rec,
2690                  rtx *loc, basic_block bb, struct df_insn_info *insn_info,
2691 		 int flags)
2692 {
2693   rtx dst = *loc;
2694 
2695   /* It is legal to have a set destination be a parallel. */
2696   if (GET_CODE (dst) == PARALLEL)
2697     {
2698       int i;
2699       for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
2700 	{
2701 	  rtx temp = XVECEXP (dst, 0, i);
2702 	  gcc_assert (GET_CODE (temp) == EXPR_LIST);
2703 	  df_def_record_1 (collection_rec, &XEXP (temp, 0),
2704 			   bb, insn_info, flags);
2705 	}
2706       return;
2707     }
2708 
2709   if (GET_CODE (dst) == STRICT_LOW_PART)
2710     {
2711       flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL | DF_REF_STRICT_LOW_PART;
2712 
2713       loc = &XEXP (dst, 0);
2714       dst = *loc;
2715     }
2716 
2717   if (GET_CODE (dst) == ZERO_EXTRACT)
2718     {
2719       flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL | DF_REF_ZERO_EXTRACT;
2720 
2721       loc = &XEXP (dst, 0);
2722       dst = *loc;
2723     }
2724 
2725   /* At this point if we do not have a reg or a subreg, just return.  */
2726   if (REG_P (dst))
2727     {
2728       df_ref_record (DF_REF_REGULAR, collection_rec,
2729 		     dst, loc, bb, insn_info, DF_REF_REG_DEF, flags);
2730 
2731       /* We want to keep sp alive everywhere - by making all
2732 	 writes to sp also use of sp. */
2733       if (REGNO (dst) == STACK_POINTER_REGNUM)
2734 	df_ref_record (DF_REF_BASE, collection_rec,
2735 		       dst, NULL, bb, insn_info, DF_REF_REG_USE, flags);
2736     }
2737   else if (GET_CODE (dst) == SUBREG && REG_P (SUBREG_REG (dst)))
2738     {
2739       if (df_read_modify_subreg_p (dst))
2740 	flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL;
2741 
2742       flags |= DF_REF_SUBREG;
2743 
2744       df_ref_record (DF_REF_REGULAR, collection_rec,
2745 		     dst, loc, bb, insn_info, DF_REF_REG_DEF, flags);
2746     }
2747 }
2748 
2749 
2750 /* Process all the registers defined in the pattern rtx, X.  Any change
2751    here has to be matched in df_find_hard_reg_defs.  */
2752 
2753 static void
2754 df_defs_record (struct df_collection_rec *collection_rec,
2755                 rtx x, basic_block bb, struct df_insn_info *insn_info,
2756 		int flags)
2757 {
2758   RTX_CODE code = GET_CODE (x);
2759   int i;
2760 
2761   switch (code)
2762     {
2763     case SET:
2764       df_def_record_1 (collection_rec, &SET_DEST (x), bb, insn_info, flags);
2765       break;
2766 
2767     case CLOBBER:
2768       flags |= DF_REF_MUST_CLOBBER;
2769       df_def_record_1 (collection_rec, &XEXP (x, 0), bb, insn_info, flags);
2770       break;
2771 
2772     case COND_EXEC:
2773       df_defs_record (collection_rec, COND_EXEC_CODE (x),
2774 		      bb, insn_info, DF_REF_CONDITIONAL);
2775       break;
2776 
2777     case PARALLEL:
2778       for (i = 0; i < XVECLEN (x, 0); i++)
2779 	df_defs_record (collection_rec, XVECEXP (x, 0, i),
2780 			bb, insn_info, flags);
2781       break;
2782     default:
2783       /* No DEFs to record in other cases */
2784       break;
2785     }
2786 }
2787 
2788 /* Set bits in *DEFS for hard registers found in the rtx DST, which is the
2789    destination of a set or clobber.  This has to match the logic in
2790    df_defs_record_1.  */
2791 
2792 static void
2793 df_find_hard_reg_defs_1 (rtx dst, HARD_REG_SET *defs)
2794 {
2795   /* It is legal to have a set destination be a parallel. */
2796   if (GET_CODE (dst) == PARALLEL)
2797     {
2798       int i;
2799       for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
2800 	{
2801 	  rtx temp = XVECEXP (dst, 0, i);
2802 	  gcc_assert (GET_CODE (temp) == EXPR_LIST);
2803 	  df_find_hard_reg_defs_1 (XEXP (temp, 0), defs);
2804 	}
2805       return;
2806     }
2807 
2808   if (GET_CODE (dst) == STRICT_LOW_PART)
2809       dst = XEXP (dst, 0);
2810 
2811   if (GET_CODE (dst) == ZERO_EXTRACT)
2812       dst = XEXP (dst, 0);
2813 
2814   /* At this point if we do not have a reg or a subreg, just return.  */
2815   if (REG_P (dst) && HARD_REGISTER_P (dst))
2816     SET_HARD_REG_BIT (*defs, REGNO (dst));
2817   else if (GET_CODE (dst) == SUBREG
2818 	   && REG_P (SUBREG_REG (dst)) && HARD_REGISTER_P (dst))
2819     SET_HARD_REG_BIT (*defs, REGNO (SUBREG_REG (dst)));
2820 }
2821 
2822 /* Set bits in *DEFS for hard registers defined in the pattern X.  This
2823    has to match the logic in df_defs_record.  */
2824 
2825 static void
2826 df_find_hard_reg_defs (rtx x, HARD_REG_SET *defs)
2827 {
2828   RTX_CODE code = GET_CODE (x);
2829   int i;
2830 
2831   switch (code)
2832     {
2833     case SET:
2834       df_find_hard_reg_defs_1 (SET_DEST (x), defs);
2835       break;
2836 
2837     case CLOBBER:
2838       df_find_hard_reg_defs_1 (XEXP (x, 0), defs);
2839       break;
2840 
2841     case COND_EXEC:
2842       df_find_hard_reg_defs (COND_EXEC_CODE (x), defs);
2843       break;
2844 
2845     case PARALLEL:
2846       for (i = 0; i < XVECLEN (x, 0); i++)
2847 	df_find_hard_reg_defs (XVECEXP (x, 0, i), defs);
2848       break;
2849     default:
2850       /* No DEFs to record in other cases */
2851       break;
2852     }
2853 }
2854 
2855 
2856 /* Process all the registers used in the rtx at address LOC.  */
2857 
2858 static void
2859 df_uses_record (struct df_collection_rec *collection_rec,
2860                 rtx *loc, enum df_ref_type ref_type,
2861 		basic_block bb, struct df_insn_info *insn_info,
2862 		int flags)
2863 {
2864   RTX_CODE code;
2865   rtx x;
2866 
2867  retry:
2868   x = *loc;
2869   if (!x)
2870     return;
2871   code = GET_CODE (x);
2872   switch (code)
2873     {
2874     case LABEL_REF:
2875     case SYMBOL_REF:
2876     case CONST:
2877     CASE_CONST_ANY:
2878     case PC:
2879     case CC0:
2880     case ADDR_VEC:
2881     case ADDR_DIFF_VEC:
2882       return;
2883 
2884     case CLOBBER:
2885       /* If we are clobbering a MEM, mark any registers inside the address
2886 	 as being used.  */
2887       if (MEM_P (XEXP (x, 0)))
2888 	df_uses_record (collection_rec,
2889 			&XEXP (XEXP (x, 0), 0),
2890 			DF_REF_REG_MEM_STORE,
2891 		        bb, insn_info,
2892 			flags);
2893 
2894       /* If we're clobbering a REG then we have a def so ignore.  */
2895       return;
2896 
2897     case MEM:
2898       df_uses_record (collection_rec,
2899 		      &XEXP (x, 0), DF_REF_REG_MEM_LOAD,
2900 		      bb, insn_info, flags & DF_REF_IN_NOTE);
2901       return;
2902 
2903     case SUBREG:
2904       /* While we're here, optimize this case.  */
2905       flags |= DF_REF_PARTIAL;
2906       /* In case the SUBREG is not of a REG, do not optimize.  */
2907       if (!REG_P (SUBREG_REG (x)))
2908 	{
2909 	  loc = &SUBREG_REG (x);
2910 	  df_uses_record (collection_rec, loc, ref_type, bb, insn_info, flags);
2911 	  return;
2912 	}
2913       /* ... Fall through ...  */
2914 
2915     case REG:
2916       df_ref_record (DF_REF_REGULAR, collection_rec,
2917 		     x, loc, bb, insn_info,
2918 		     ref_type, flags);
2919       return;
2920 
2921     case SIGN_EXTRACT:
2922     case ZERO_EXTRACT:
2923       {
2924         df_uses_record (collection_rec,
2925                         &XEXP (x, 1), ref_type, bb, insn_info, flags);
2926         df_uses_record (collection_rec,
2927                         &XEXP (x, 2), ref_type, bb, insn_info, flags);
2928 
2929         /* If the parameters to the zero or sign extract are
2930            constants, strip them off and recurse, otherwise there is
2931            no information that we can gain from this operation.  */
2932         if (code == ZERO_EXTRACT)
2933           flags |= DF_REF_ZERO_EXTRACT;
2934         else
2935           flags |= DF_REF_SIGN_EXTRACT;
2936 
2937         df_uses_record (collection_rec,
2938                         &XEXP (x, 0), ref_type, bb, insn_info, flags);
2939         return;
2940       }
2941       break;
2942 
2943     case SET:
2944       {
2945 	rtx dst = SET_DEST (x);
2946 	gcc_assert (!(flags & DF_REF_IN_NOTE));
2947 	df_uses_record (collection_rec,
2948 			&SET_SRC (x), DF_REF_REG_USE, bb, insn_info, flags);
2949 
2950 	switch (GET_CODE (dst))
2951 	  {
2952 	    case SUBREG:
2953 	      if (df_read_modify_subreg_p (dst))
2954 		{
2955 		  df_uses_record (collection_rec, &SUBREG_REG (dst),
2956 				  DF_REF_REG_USE, bb, insn_info,
2957 				  flags | DF_REF_READ_WRITE | DF_REF_SUBREG);
2958 		  break;
2959 		}
2960 	      /* Fall through.  */
2961 	    case REG:
2962 	    case PARALLEL:
2963 	    case SCRATCH:
2964 	    case PC:
2965 	    case CC0:
2966 		break;
2967 	    case MEM:
2968 	      df_uses_record (collection_rec, &XEXP (dst, 0),
2969 			      DF_REF_REG_MEM_STORE, bb, insn_info, flags);
2970 	      break;
2971 	    case STRICT_LOW_PART:
2972 	      {
2973 		rtx *temp = &XEXP (dst, 0);
2974 		/* A strict_low_part uses the whole REG and not just the
2975 		 SUBREG.  */
2976 		dst = XEXP (dst, 0);
2977 		df_uses_record (collection_rec,
2978 				(GET_CODE (dst) == SUBREG) ? &SUBREG_REG (dst) : temp,
2979 				DF_REF_REG_USE, bb, insn_info,
2980 				DF_REF_READ_WRITE | DF_REF_STRICT_LOW_PART);
2981 	      }
2982 	      break;
2983 	    case ZERO_EXTRACT:
2984 	      {
2985 		df_uses_record (collection_rec, &XEXP (dst, 1),
2986 				DF_REF_REG_USE, bb, insn_info, flags);
2987 		df_uses_record (collection_rec, &XEXP (dst, 2),
2988 				DF_REF_REG_USE, bb, insn_info, flags);
2989                 if (GET_CODE (XEXP (dst,0)) == MEM)
2990                   df_uses_record (collection_rec, &XEXP (dst, 0),
2991                                   DF_REF_REG_USE, bb, insn_info,
2992                                   flags);
2993                 else
2994                   df_uses_record (collection_rec, &XEXP (dst, 0),
2995                                   DF_REF_REG_USE, bb, insn_info,
2996                                   DF_REF_READ_WRITE | DF_REF_ZERO_EXTRACT);
2997 	      }
2998 	      break;
2999 
3000 	    default:
3001 	      gcc_unreachable ();
3002 	  }
3003 	return;
3004       }
3005 
3006     case RETURN:
3007     case SIMPLE_RETURN:
3008       break;
3009 
3010     case ASM_OPERANDS:
3011     case UNSPEC_VOLATILE:
3012     case TRAP_IF:
3013     case ASM_INPUT:
3014       {
3015 	/* Traditional and volatile asm instructions must be
3016 	   considered to use and clobber all hard registers, all
3017 	   pseudo-registers and all of memory.  So must TRAP_IF and
3018 	   UNSPEC_VOLATILE operations.
3019 
3020 	   Consider for instance a volatile asm that changes the fpu
3021 	   rounding mode.  An insn should not be moved across this
3022 	   even if it only uses pseudo-regs because it might give an
3023 	   incorrectly rounded result.
3024 
3025 	   However, flow.c's liveness computation did *not* do this,
3026 	   giving the reasoning as " ?!? Unfortunately, marking all
3027 	   hard registers as live causes massive problems for the
3028 	   register allocator and marking all pseudos as live creates
3029 	   mountains of uninitialized variable warnings."
3030 
3031 	   In order to maintain the status quo with regard to liveness
3032 	   and uses, we do what flow.c did and just mark any regs we
3033 	   can find in ASM_OPERANDS as used.  In global asm insns are
3034 	   scanned and regs_asm_clobbered is filled out.
3035 
3036 	   For all ASM_OPERANDS, we must traverse the vector of input
3037 	   operands.  We can not just fall through here since then we
3038 	   would be confused by the ASM_INPUT rtx inside ASM_OPERANDS,
3039 	   which do not indicate traditional asms unlike their normal
3040 	   usage.  */
3041 	if (code == ASM_OPERANDS)
3042 	  {
3043 	    int j;
3044 
3045 	    for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++)
3046 	      df_uses_record (collection_rec, &ASM_OPERANDS_INPUT (x, j),
3047 			      DF_REF_REG_USE, bb, insn_info, flags);
3048 	    return;
3049 	  }
3050 	break;
3051       }
3052 
3053     case VAR_LOCATION:
3054       df_uses_record (collection_rec,
3055 		      &PAT_VAR_LOCATION_LOC (x),
3056 		      DF_REF_REG_USE, bb, insn_info, flags);
3057       return;
3058 
3059     case PRE_DEC:
3060     case POST_DEC:
3061     case PRE_INC:
3062     case POST_INC:
3063     case PRE_MODIFY:
3064     case POST_MODIFY:
3065       gcc_assert (!DEBUG_INSN_P (insn_info->insn));
3066       /* Catch the def of the register being modified.  */
3067       df_ref_record (DF_REF_REGULAR, collection_rec, XEXP (x, 0), &XEXP (x, 0),
3068 		     bb, insn_info,
3069 		     DF_REF_REG_DEF,
3070                      flags | DF_REF_READ_WRITE | DF_REF_PRE_POST_MODIFY);
3071 
3072       /* ... Fall through to handle uses ...  */
3073 
3074     default:
3075       break;
3076     }
3077 
3078   /* Recursively scan the operands of this expression.  */
3079   {
3080     const char *fmt = GET_RTX_FORMAT (code);
3081     int i;
3082 
3083     for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3084       {
3085 	if (fmt[i] == 'e')
3086 	  {
3087 	    /* Tail recursive case: save a function call level.  */
3088 	    if (i == 0)
3089 	      {
3090 		loc = &XEXP (x, 0);
3091 		goto retry;
3092 	      }
3093 	    df_uses_record (collection_rec, &XEXP (x, i), ref_type,
3094 			    bb, insn_info, flags);
3095 	  }
3096 	else if (fmt[i] == 'E')
3097 	  {
3098 	    int j;
3099 	    for (j = 0; j < XVECLEN (x, i); j++)
3100 	      df_uses_record (collection_rec,
3101 			      &XVECEXP (x, i, j), ref_type,
3102 			      bb, insn_info, flags);
3103 	  }
3104       }
3105   }
3106 
3107   return;
3108 }
3109 
3110 
3111 /* For all DF_REF_CONDITIONAL defs, add a corresponding uses.  */
3112 
3113 static void
3114 df_get_conditional_uses (struct df_collection_rec *collection_rec)
3115 {
3116   unsigned int ix;
3117   df_ref ref;
3118 
3119   FOR_EACH_VEC_ELT (collection_rec->def_vec, ix, ref)
3120     {
3121       if (DF_REF_FLAGS_IS_SET (ref, DF_REF_CONDITIONAL))
3122         {
3123           df_ref use;
3124 
3125           use = df_ref_create_structure (DF_REF_CLASS (ref), collection_rec, DF_REF_REG (ref),
3126 					 DF_REF_LOC (ref), DF_REF_BB (ref),
3127 					 DF_REF_INSN_INFO (ref), DF_REF_REG_USE,
3128 					 DF_REF_FLAGS (ref) & ~DF_REF_CONDITIONAL);
3129           DF_REF_REGNO (use) = DF_REF_REGNO (ref);
3130         }
3131     }
3132 }
3133 
3134 
3135 /* Get call's extra defs and uses (track caller-saved registers). */
3136 
3137 static void
3138 df_get_call_refs (struct df_collection_rec *collection_rec,
3139                   basic_block bb,
3140                   struct df_insn_info *insn_info,
3141                   int flags)
3142 {
3143   rtx note;
3144   bool is_sibling_call;
3145   unsigned int i;
3146   HARD_REG_SET defs_generated;
3147   HARD_REG_SET fn_reg_set_usage;
3148 
3149   CLEAR_HARD_REG_SET (defs_generated);
3150   df_find_hard_reg_defs (PATTERN (insn_info->insn), &defs_generated);
3151   is_sibling_call = SIBLING_CALL_P (insn_info->insn);
3152   get_call_reg_set_usage (insn_info->insn, &fn_reg_set_usage,
3153 			  regs_invalidated_by_call);
3154 
3155   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3156     {
3157       if (i == STACK_POINTER_REGNUM)
3158 	/* The stack ptr is used (honorarily) by a CALL insn.  */
3159 	df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3160 		       NULL, bb, insn_info, DF_REF_REG_USE,
3161 		       DF_REF_CALL_STACK_USAGE | flags);
3162       else if (global_regs[i])
3163 	{
3164 	  /* Calls to const functions cannot access any global registers and
3165 	     calls to pure functions cannot set them.  All other calls may
3166 	     reference any of the global registers, so they are recorded as
3167 	     used. */
3168 	  if (!RTL_CONST_CALL_P (insn_info->insn))
3169 	    {
3170 	      df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3171 			     NULL, bb, insn_info, DF_REF_REG_USE, flags);
3172 	      if (!RTL_PURE_CALL_P (insn_info->insn))
3173 		df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3174 			       NULL, bb, insn_info, DF_REF_REG_DEF, flags);
3175 	    }
3176 	}
3177       else if (TEST_HARD_REG_BIT (fn_reg_set_usage, i)
3178 	       /* no clobbers for regs that are the result of the call */
3179 	       && !TEST_HARD_REG_BIT (defs_generated, i)
3180 	       && (!is_sibling_call
3181 		   || !bitmap_bit_p (df->exit_block_uses, i)
3182 		   || refers_to_regno_p (i, crtl->return_rtx)))
3183 	  df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3184 			 NULL, bb, insn_info, DF_REF_REG_DEF,
3185 			 DF_REF_MAY_CLOBBER | flags);
3186     }
3187 
3188   /* Record the registers used to pass arguments, and explicitly
3189      noted as clobbered.  */
3190   for (note = CALL_INSN_FUNCTION_USAGE (insn_info->insn); note;
3191        note = XEXP (note, 1))
3192     {
3193       if (GET_CODE (XEXP (note, 0)) == USE)
3194         df_uses_record (collection_rec, &XEXP (XEXP (note, 0), 0),
3195 			DF_REF_REG_USE, bb, insn_info, flags);
3196       else if (GET_CODE (XEXP (note, 0)) == CLOBBER)
3197 	{
3198 	  if (REG_P (XEXP (XEXP (note, 0), 0)))
3199 	    {
3200 	      unsigned int regno = REGNO (XEXP (XEXP (note, 0), 0));
3201 	      if (!TEST_HARD_REG_BIT (defs_generated, regno))
3202 		df_defs_record (collection_rec, XEXP (note, 0), bb,
3203 				insn_info, flags);
3204 	    }
3205 	  else
3206 	    df_uses_record (collection_rec, &XEXP (note, 0),
3207 		            DF_REF_REG_USE, bb, insn_info, flags);
3208 	}
3209     }
3210 
3211   return;
3212 }
3213 
3214 /* Collect all refs in the INSN. This function is free of any
3215    side-effect - it will create and return a lists of df_ref's in the
3216    COLLECTION_REC without putting those refs into existing ref chains
3217    and reg chains. */
3218 
3219 static void
3220 df_insn_refs_collect (struct df_collection_rec *collection_rec,
3221 		      basic_block bb, struct df_insn_info *insn_info)
3222 {
3223   rtx note;
3224   bool is_cond_exec = (GET_CODE (PATTERN (insn_info->insn)) == COND_EXEC);
3225 
3226   /* Clear out the collection record.  */
3227   collection_rec->def_vec.truncate (0);
3228   collection_rec->use_vec.truncate (0);
3229   collection_rec->eq_use_vec.truncate (0);
3230   collection_rec->mw_vec.truncate (0);
3231 
3232   /* Process REG_EQUIV/REG_EQUAL notes.  */
3233   for (note = REG_NOTES (insn_info->insn); note;
3234        note = XEXP (note, 1))
3235     {
3236       switch (REG_NOTE_KIND (note))
3237         {
3238         case REG_EQUIV:
3239         case REG_EQUAL:
3240           df_uses_record (collection_rec,
3241                           &XEXP (note, 0), DF_REF_REG_USE,
3242                           bb, insn_info, DF_REF_IN_NOTE);
3243           break;
3244         case REG_NON_LOCAL_GOTO:
3245           /* The frame ptr is used by a non-local goto.  */
3246           df_ref_record (DF_REF_BASE, collection_rec,
3247                          regno_reg_rtx[FRAME_POINTER_REGNUM],
3248                          NULL, bb, insn_info,
3249                          DF_REF_REG_USE, 0);
3250 #if !HARD_FRAME_POINTER_IS_FRAME_POINTER
3251           df_ref_record (DF_REF_BASE, collection_rec,
3252                          regno_reg_rtx[HARD_FRAME_POINTER_REGNUM],
3253                          NULL, bb, insn_info,
3254                          DF_REF_REG_USE, 0);
3255 #endif
3256           break;
3257         default:
3258           break;
3259         }
3260     }
3261 
3262   /* For CALL_INSNs, first record DF_REF_BASE register defs, as well as
3263      uses from CALL_INSN_FUNCTION_USAGE. */
3264   if (CALL_P (insn_info->insn))
3265     df_get_call_refs (collection_rec, bb, insn_info,
3266 		      (is_cond_exec) ? DF_REF_CONDITIONAL : 0);
3267 
3268   /* Record other defs.  These should be mostly for DF_REF_REGULAR, so
3269      that a qsort on the defs is unnecessary in most cases.  */
3270   df_defs_record (collection_rec,
3271 		  PATTERN (insn_info->insn), bb, insn_info, 0);
3272 
3273   /* Record the register uses.  */
3274   df_uses_record (collection_rec,
3275 		  &PATTERN (insn_info->insn), DF_REF_REG_USE, bb, insn_info, 0);
3276 
3277   /* DF_REF_CONDITIONAL needs corresponding USES. */
3278   if (is_cond_exec)
3279     df_get_conditional_uses (collection_rec);
3280 
3281   df_canonize_collection_rec (collection_rec);
3282 }
3283 
3284 /* Recompute the luids for the insns in BB.  */
3285 
3286 void
3287 df_recompute_luids (basic_block bb)
3288 {
3289   rtx_insn *insn;
3290   int luid = 0;
3291 
3292   df_grow_insn_info ();
3293 
3294   /* Scan the block an insn at a time from beginning to end.  */
3295   FOR_BB_INSNS (bb, insn)
3296     {
3297       struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
3298       /* Inserting labels does not always trigger the incremental
3299 	 rescanning.  */
3300       if (!insn_info)
3301 	{
3302 	  gcc_assert (!INSN_P (insn));
3303 	  insn_info = df_insn_create_insn_record (insn);
3304 	}
3305 
3306       DF_INSN_INFO_LUID (insn_info) = luid;
3307       if (INSN_P (insn))
3308 	luid++;
3309     }
3310 }
3311 
3312 
3313 /* Collect all artificial refs at the block level for BB and add them
3314    to COLLECTION_REC.  */
3315 
3316 static void
3317 df_bb_refs_collect (struct df_collection_rec *collection_rec, basic_block bb)
3318 {
3319   collection_rec->def_vec.truncate (0);
3320   collection_rec->use_vec.truncate (0);
3321   collection_rec->eq_use_vec.truncate (0);
3322   collection_rec->mw_vec.truncate (0);
3323 
3324   if (bb->index == ENTRY_BLOCK)
3325     {
3326       df_entry_block_defs_collect (collection_rec, df->entry_block_defs);
3327       return;
3328     }
3329   else if (bb->index == EXIT_BLOCK)
3330     {
3331       df_exit_block_uses_collect (collection_rec, df->exit_block_uses);
3332       return;
3333     }
3334 
3335 #ifdef EH_RETURN_DATA_REGNO
3336   if (bb_has_eh_pred (bb))
3337     {
3338       unsigned int i;
3339       /* Mark the registers that will contain data for the handler.  */
3340       for (i = 0; ; ++i)
3341 	{
3342 	  unsigned regno = EH_RETURN_DATA_REGNO (i);
3343 	  if (regno == INVALID_REGNUM)
3344 	    break;
3345 	  df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[regno], NULL,
3346 			 bb, NULL, DF_REF_REG_DEF, DF_REF_AT_TOP);
3347 	}
3348     }
3349 #endif
3350 
3351   /* Add the hard_frame_pointer if this block is the target of a
3352      non-local goto.  */
3353   if (bb->flags & BB_NON_LOCAL_GOTO_TARGET)
3354     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, hard_frame_pointer_rtx, NULL,
3355 		   bb, NULL, DF_REF_REG_DEF, DF_REF_AT_TOP);
3356 
3357   /* Add the artificial uses.  */
3358   if (bb->index >= NUM_FIXED_BLOCKS)
3359     {
3360       bitmap_iterator bi;
3361       unsigned int regno;
3362       bitmap au = bb_has_eh_pred (bb)
3363 	? &df->eh_block_artificial_uses
3364 	: &df->regular_block_artificial_uses;
3365 
3366       EXECUTE_IF_SET_IN_BITMAP (au, 0, regno, bi)
3367 	{
3368 	  df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[regno], NULL,
3369 			 bb, NULL, DF_REF_REG_USE, 0);
3370 	}
3371     }
3372 
3373   df_canonize_collection_rec (collection_rec);
3374 }
3375 
3376 
3377 /* Record all the refs within the basic block BB_INDEX and scan the instructions if SCAN_INSNS.  */
3378 
3379 void
3380 df_bb_refs_record (int bb_index, bool scan_insns)
3381 {
3382   basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
3383   rtx_insn *insn;
3384   int luid = 0;
3385 
3386   if (!df)
3387     return;
3388 
3389   df_collection_rec collection_rec;
3390   df_grow_bb_info (df_scan);
3391   if (scan_insns)
3392     /* Scan the block an insn at a time from beginning to end.  */
3393     FOR_BB_INSNS (bb, insn)
3394       {
3395 	struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
3396 	gcc_assert (!insn_info);
3397 
3398 	insn_info = df_insn_create_insn_record (insn);
3399 	if (INSN_P (insn))
3400 	  {
3401 	    /* Record refs within INSN.  */
3402 	    DF_INSN_INFO_LUID (insn_info) = luid++;
3403 	    df_insn_refs_collect (&collection_rec, bb, DF_INSN_INFO_GET (insn));
3404 	    df_refs_add_to_chains (&collection_rec, bb, insn, copy_all);
3405 	  }
3406 	DF_INSN_INFO_LUID (insn_info) = luid;
3407       }
3408 
3409   /* Other block level artificial refs */
3410   df_bb_refs_collect (&collection_rec, bb);
3411   df_refs_add_to_chains (&collection_rec, bb, NULL, copy_all);
3412 
3413   /* Now that the block has been processed, set the block as dirty so
3414      LR and LIVE will get it processed.  */
3415   df_set_bb_dirty (bb);
3416 }
3417 
3418 
3419 /* Get the artificial use set for a regular (i.e. non-exit/non-entry)
3420    block. */
3421 
3422 static void
3423 df_get_regular_block_artificial_uses (bitmap regular_block_artificial_uses)
3424 {
3425 #ifdef EH_USES
3426   unsigned int i;
3427 #endif
3428 
3429   bitmap_clear (regular_block_artificial_uses);
3430 
3431   if (reload_completed)
3432     {
3433       if (frame_pointer_needed)
3434 	bitmap_set_bit (regular_block_artificial_uses, HARD_FRAME_POINTER_REGNUM);
3435     }
3436   else
3437     /* Before reload, there are a few registers that must be forced
3438        live everywhere -- which might not already be the case for
3439        blocks within infinite loops.  */
3440     {
3441       unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3442 
3443       /* Any reference to any pseudo before reload is a potential
3444 	 reference of the frame pointer.  */
3445       bitmap_set_bit (regular_block_artificial_uses, FRAME_POINTER_REGNUM);
3446 
3447 #if !HARD_FRAME_POINTER_IS_FRAME_POINTER
3448       bitmap_set_bit (regular_block_artificial_uses, HARD_FRAME_POINTER_REGNUM);
3449 #endif
3450 
3451 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3452       /* Pseudos with argument area equivalences may require
3453 	 reloading via the argument pointer.  */
3454       if (fixed_regs[ARG_POINTER_REGNUM])
3455 	bitmap_set_bit (regular_block_artificial_uses, ARG_POINTER_REGNUM);
3456 #endif
3457 
3458       /* Any constant, or pseudo with constant equivalences, may
3459 	 require reloading from memory using the pic register.  */
3460       if (picreg != INVALID_REGNUM
3461 	  && fixed_regs[picreg])
3462 	bitmap_set_bit (regular_block_artificial_uses, picreg);
3463     }
3464   /* The all-important stack pointer must always be live.  */
3465   bitmap_set_bit (regular_block_artificial_uses, STACK_POINTER_REGNUM);
3466 
3467 #ifdef EH_USES
3468   /* EH_USES registers are used:
3469      1) at all insns that might throw (calls or with -fnon-call-exceptions
3470 	trapping insns)
3471      2) in all EH edges
3472      3) to support backtraces and/or debugging, anywhere between their
3473 	initialization and where they the saved registers are restored
3474 	from them, including the cases where we don't reach the epilogue
3475 	(noreturn call or infinite loop).  */
3476   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3477     if (EH_USES (i))
3478       bitmap_set_bit (regular_block_artificial_uses, i);
3479 #endif
3480 }
3481 
3482 
3483 /* Get the artificial use set for an eh block. */
3484 
3485 static void
3486 df_get_eh_block_artificial_uses (bitmap eh_block_artificial_uses)
3487 {
3488   bitmap_clear (eh_block_artificial_uses);
3489 
3490   /* The following code (down through the arg_pointer setting APPEARS
3491      to be necessary because there is nothing that actually
3492      describes what the exception handling code may actually need
3493      to keep alive.  */
3494   if (reload_completed)
3495     {
3496       if (frame_pointer_needed)
3497 	{
3498 	  bitmap_set_bit (eh_block_artificial_uses, FRAME_POINTER_REGNUM);
3499 #if !HARD_FRAME_POINTER_IS_FRAME_POINTER
3500 	  bitmap_set_bit (eh_block_artificial_uses, HARD_FRAME_POINTER_REGNUM);
3501 #endif
3502 	}
3503 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3504       if (fixed_regs[ARG_POINTER_REGNUM])
3505 	bitmap_set_bit (eh_block_artificial_uses, ARG_POINTER_REGNUM);
3506 #endif
3507     }
3508 }
3509 
3510 
3511 
3512 /*----------------------------------------------------------------------------
3513    Specialized hard register scanning functions.
3514 ----------------------------------------------------------------------------*/
3515 
3516 
3517 /* Mark a register in SET.  Hard registers in large modes get all
3518    of their component registers set as well.  */
3519 
3520 static void
3521 df_mark_reg (rtx reg, void *vset)
3522 {
3523   bitmap set = (bitmap) vset;
3524   int regno = REGNO (reg);
3525 
3526   gcc_assert (GET_MODE (reg) != BLKmode);
3527 
3528   if (regno < FIRST_PSEUDO_REGISTER)
3529     {
3530       int n = hard_regno_nregs[regno][GET_MODE (reg)];
3531       bitmap_set_range (set, regno, n);
3532     }
3533   else
3534     bitmap_set_bit (set, regno);
3535 }
3536 
3537 
3538 /* Set the bit for regs that are considered being defined at the entry. */
3539 
3540 static void
3541 df_get_entry_block_def_set (bitmap entry_block_defs)
3542 {
3543   rtx r;
3544   int i;
3545 
3546   bitmap_clear (entry_block_defs);
3547 
3548   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3549     {
3550       if (global_regs[i])
3551 	bitmap_set_bit (entry_block_defs, i);
3552       if (FUNCTION_ARG_REGNO_P (i))
3553 	bitmap_set_bit (entry_block_defs, INCOMING_REGNO (i));
3554     }
3555 
3556   /* The always important stack pointer.  */
3557   bitmap_set_bit (entry_block_defs, STACK_POINTER_REGNUM);
3558 
3559   /* Once the prologue has been generated, all of these registers
3560      should just show up in the first regular block.  */
3561   if (HAVE_prologue && epilogue_completed)
3562     {
3563       /* Defs for the callee saved registers are inserted so that the
3564 	 pushes have some defining location.  */
3565       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3566 	if ((call_used_regs[i] == 0) && (df_regs_ever_live_p (i)))
3567 	  bitmap_set_bit (entry_block_defs, i);
3568     }
3569 
3570   r = targetm.calls.struct_value_rtx (current_function_decl, true);
3571   if (r && REG_P (r))
3572     bitmap_set_bit (entry_block_defs, REGNO (r));
3573 
3574   /* If the function has an incoming STATIC_CHAIN, it has to show up
3575      in the entry def set.  */
3576   r = targetm.calls.static_chain (current_function_decl, true);
3577   if (r && REG_P (r))
3578     bitmap_set_bit (entry_block_defs, REGNO (r));
3579 
3580   if ((!reload_completed) || frame_pointer_needed)
3581     {
3582       /* Any reference to any pseudo before reload is a potential
3583 	 reference of the frame pointer.  */
3584       bitmap_set_bit (entry_block_defs, FRAME_POINTER_REGNUM);
3585 #if !HARD_FRAME_POINTER_IS_FRAME_POINTER
3586       /* If they are different, also mark the hard frame pointer as live.  */
3587       if (!LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM))
3588 	bitmap_set_bit (entry_block_defs, HARD_FRAME_POINTER_REGNUM);
3589 #endif
3590     }
3591 
3592   /* These registers are live everywhere.  */
3593   if (!reload_completed)
3594     {
3595 #ifdef PIC_OFFSET_TABLE_REGNUM
3596       unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3597 #endif
3598 
3599 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3600       /* Pseudos with argument area equivalences may require
3601 	 reloading via the argument pointer.  */
3602       if (fixed_regs[ARG_POINTER_REGNUM])
3603 	bitmap_set_bit (entry_block_defs, ARG_POINTER_REGNUM);
3604 #endif
3605 
3606 #ifdef PIC_OFFSET_TABLE_REGNUM
3607       /* Any constant, or pseudo with constant equivalences, may
3608 	 require reloading from memory using the pic register.  */
3609       if (picreg != INVALID_REGNUM
3610 	  && fixed_regs[picreg])
3611 	bitmap_set_bit (entry_block_defs, picreg);
3612 #endif
3613     }
3614 
3615 #ifdef INCOMING_RETURN_ADDR_RTX
3616   if (REG_P (INCOMING_RETURN_ADDR_RTX))
3617     bitmap_set_bit (entry_block_defs, REGNO (INCOMING_RETURN_ADDR_RTX));
3618 #endif
3619 
3620   targetm.extra_live_on_entry (entry_block_defs);
3621 }
3622 
3623 
3624 /* Return the (conservative) set of hard registers that are defined on
3625    entry to the function.
3626    It uses df->entry_block_defs to determine which register
3627    reference to include.  */
3628 
3629 static void
3630 df_entry_block_defs_collect (struct df_collection_rec *collection_rec,
3631 			     bitmap entry_block_defs)
3632 {
3633   unsigned int i;
3634   bitmap_iterator bi;
3635 
3636   EXECUTE_IF_SET_IN_BITMAP (entry_block_defs, 0, i, bi)
3637     {
3638       df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[i], NULL,
3639 		     ENTRY_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_DEF, 0);
3640     }
3641 
3642   df_canonize_collection_rec (collection_rec);
3643 }
3644 
3645 
3646 /* Record the (conservative) set of hard registers that are defined on
3647    entry to the function.  */
3648 
3649 static void
3650 df_record_entry_block_defs (bitmap entry_block_defs)
3651 {
3652   struct df_collection_rec collection_rec;
3653   df_entry_block_defs_collect (&collection_rec, entry_block_defs);
3654 
3655   /* Process bb_refs chain */
3656   df_refs_add_to_chains (&collection_rec,
3657 			 BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK),
3658 			 NULL,
3659 			 copy_defs);
3660 }
3661 
3662 
3663 /* Update the defs in the entry block.  */
3664 
3665 void
3666 df_update_entry_block_defs (void)
3667 {
3668   bitmap_head refs;
3669   bool changed = false;
3670 
3671   bitmap_initialize (&refs, &df_bitmap_obstack);
3672   df_get_entry_block_def_set (&refs);
3673   if (df->entry_block_defs)
3674     {
3675       if (!bitmap_equal_p (df->entry_block_defs, &refs))
3676 	{
3677 	  struct df_scan_bb_info *bb_info = df_scan_get_bb_info (ENTRY_BLOCK);
3678 	  df_ref_chain_delete_du_chain (bb_info->artificial_defs);
3679 	  df_ref_chain_delete (bb_info->artificial_defs);
3680 	  bb_info->artificial_defs = NULL;
3681 	  changed = true;
3682 	}
3683     }
3684   else
3685     {
3686       struct df_scan_problem_data *problem_data
3687 	= (struct df_scan_problem_data *) df_scan->problem_data;
3688 	gcc_unreachable ();
3689       df->entry_block_defs = BITMAP_ALLOC (&problem_data->reg_bitmaps);
3690       changed = true;
3691     }
3692 
3693   if (changed)
3694     {
3695       df_record_entry_block_defs (&refs);
3696       bitmap_copy (df->entry_block_defs, &refs);
3697       df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK));
3698     }
3699   bitmap_clear (&refs);
3700 }
3701 
3702 
3703 /* Set the bit for regs that are considered being used at the exit. */
3704 
3705 static void
3706 df_get_exit_block_use_set (bitmap exit_block_uses)
3707 {
3708   unsigned int i;
3709   unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3710 
3711   bitmap_clear (exit_block_uses);
3712 
3713   /* Stack pointer is always live at the exit.  */
3714   bitmap_set_bit (exit_block_uses, STACK_POINTER_REGNUM);
3715 
3716   /* Mark the frame pointer if needed at the end of the function.
3717      If we end up eliminating it, it will be removed from the live
3718      list of each basic block by reload.  */
3719 
3720   if ((!reload_completed) || frame_pointer_needed)
3721     {
3722       bitmap_set_bit (exit_block_uses, FRAME_POINTER_REGNUM);
3723 #if !HARD_FRAME_POINTER_IS_FRAME_POINTER
3724       /* If they are different, also mark the hard frame pointer as live.  */
3725       if (!LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM))
3726 	bitmap_set_bit (exit_block_uses, HARD_FRAME_POINTER_REGNUM);
3727 #endif
3728     }
3729 
3730   /* Many architectures have a GP register even without flag_pic.
3731      Assume the pic register is not in use, or will be handled by
3732      other means, if it is not fixed.  */
3733   if (!PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
3734       && picreg != INVALID_REGNUM
3735       && fixed_regs[picreg])
3736     bitmap_set_bit (exit_block_uses, picreg);
3737 
3738   /* Mark all global registers, and all registers used by the
3739      epilogue as being live at the end of the function since they
3740      may be referenced by our caller.  */
3741   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3742     if (global_regs[i] || EPILOGUE_USES (i))
3743       bitmap_set_bit (exit_block_uses, i);
3744 
3745   if (HAVE_epilogue && epilogue_completed)
3746     {
3747       /* Mark all call-saved registers that we actually used.  */
3748       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3749 	if (df_regs_ever_live_p (i) && !LOCAL_REGNO (i)
3750 	    && !TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
3751 	  bitmap_set_bit (exit_block_uses, i);
3752     }
3753 
3754 #ifdef EH_RETURN_DATA_REGNO
3755   /* Mark the registers that will contain data for the handler.  */
3756   if (reload_completed && crtl->calls_eh_return)
3757     for (i = 0; ; ++i)
3758       {
3759 	unsigned regno = EH_RETURN_DATA_REGNO (i);
3760 	if (regno == INVALID_REGNUM)
3761 	  break;
3762 	bitmap_set_bit (exit_block_uses, regno);
3763       }
3764 #endif
3765 
3766 #ifdef EH_RETURN_STACKADJ_RTX
3767   if ((!HAVE_epilogue || ! epilogue_completed)
3768       && crtl->calls_eh_return)
3769     {
3770       rtx tmp = EH_RETURN_STACKADJ_RTX;
3771       if (tmp && REG_P (tmp))
3772 	df_mark_reg (tmp, exit_block_uses);
3773     }
3774 #endif
3775 
3776 #ifdef EH_RETURN_HANDLER_RTX
3777   if ((!HAVE_epilogue || ! epilogue_completed)
3778       && crtl->calls_eh_return)
3779     {
3780       rtx tmp = EH_RETURN_HANDLER_RTX;
3781       if (tmp && REG_P (tmp))
3782 	df_mark_reg (tmp, exit_block_uses);
3783     }
3784 #endif
3785 
3786   /* Mark function return value.  */
3787   diddle_return_value (df_mark_reg, (void*) exit_block_uses);
3788 }
3789 
3790 
3791 /* Return the refs of hard registers that are used in the exit block.
3792    It uses df->exit_block_uses to determine register to include.  */
3793 
3794 static void
3795 df_exit_block_uses_collect (struct df_collection_rec *collection_rec, bitmap exit_block_uses)
3796 {
3797   unsigned int i;
3798   bitmap_iterator bi;
3799 
3800   EXECUTE_IF_SET_IN_BITMAP (exit_block_uses, 0, i, bi)
3801     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[i], NULL,
3802 		   EXIT_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_USE, 0);
3803 
3804 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3805   /* It is deliberate that this is not put in the exit block uses but
3806      I do not know why.  */
3807   if (reload_completed
3808       && !bitmap_bit_p (exit_block_uses, ARG_POINTER_REGNUM)
3809       && bb_has_eh_pred (EXIT_BLOCK_PTR_FOR_FN (cfun))
3810       && fixed_regs[ARG_POINTER_REGNUM])
3811     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[ARG_POINTER_REGNUM], NULL,
3812 		   EXIT_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_USE, 0);
3813 #endif
3814 
3815   df_canonize_collection_rec (collection_rec);
3816 }
3817 
3818 
3819 /* Record the set of hard registers that are used in the exit block.
3820    It uses df->exit_block_uses to determine which bit to include.  */
3821 
3822 static void
3823 df_record_exit_block_uses (bitmap exit_block_uses)
3824 {
3825   struct df_collection_rec collection_rec;
3826   df_exit_block_uses_collect (&collection_rec, exit_block_uses);
3827 
3828   /* Process bb_refs chain */
3829   df_refs_add_to_chains (&collection_rec,
3830 			 BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK),
3831 			 NULL,
3832 			 copy_uses);
3833 }
3834 
3835 
3836 /* Update the uses in the exit block.  */
3837 
3838 void
3839 df_update_exit_block_uses (void)
3840 {
3841   bitmap_head refs;
3842   bool changed = false;
3843 
3844   bitmap_initialize (&refs, &df_bitmap_obstack);
3845   df_get_exit_block_use_set (&refs);
3846   if (df->exit_block_uses)
3847     {
3848       if (!bitmap_equal_p (df->exit_block_uses, &refs))
3849 	{
3850 	  struct df_scan_bb_info *bb_info = df_scan_get_bb_info (EXIT_BLOCK);
3851 	  df_ref_chain_delete_du_chain (bb_info->artificial_uses);
3852 	  df_ref_chain_delete (bb_info->artificial_uses);
3853 	  bb_info->artificial_uses = NULL;
3854 	  changed = true;
3855 	}
3856     }
3857   else
3858     {
3859       struct df_scan_problem_data *problem_data
3860 	= (struct df_scan_problem_data *) df_scan->problem_data;
3861 	gcc_unreachable ();
3862       df->exit_block_uses = BITMAP_ALLOC (&problem_data->reg_bitmaps);
3863       changed = true;
3864     }
3865 
3866   if (changed)
3867     {
3868       df_record_exit_block_uses (&refs);
3869       bitmap_copy (df->exit_block_uses,& refs);
3870       df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK));
3871     }
3872   bitmap_clear (&refs);
3873 }
3874 
3875 static bool initialized = false;
3876 
3877 
3878 /* Initialize some platform specific structures.  */
3879 
3880 void
3881 df_hard_reg_init (void)
3882 {
3883 #ifdef ELIMINABLE_REGS
3884   int i;
3885   static const struct {const int from, to; } eliminables[] = ELIMINABLE_REGS;
3886 #endif
3887   if (initialized)
3888     return;
3889 
3890   /* Record which registers will be eliminated.  We use this in
3891      mark_used_regs.  */
3892   CLEAR_HARD_REG_SET (elim_reg_set);
3893 
3894 #ifdef ELIMINABLE_REGS
3895   for (i = 0; i < (int) ARRAY_SIZE (eliminables); i++)
3896     SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from);
3897 #else
3898   SET_HARD_REG_BIT (elim_reg_set, FRAME_POINTER_REGNUM);
3899 #endif
3900 
3901   initialized = true;
3902 }
3903 
3904 
3905 /* Recompute the parts of scanning that are based on regs_ever_live
3906    because something changed in that array.  */
3907 
3908 void
3909 df_update_entry_exit_and_calls (void)
3910 {
3911   basic_block bb;
3912 
3913   df_update_entry_block_defs ();
3914   df_update_exit_block_uses ();
3915 
3916   /* The call insns need to be rescanned because there may be changes
3917      in the set of registers clobbered across the call.  */
3918   FOR_EACH_BB_FN (bb, cfun)
3919     {
3920       rtx_insn *insn;
3921       FOR_BB_INSNS (bb, insn)
3922 	{
3923 	  if (INSN_P (insn) && CALL_P (insn))
3924 	    df_insn_rescan (insn);
3925 	}
3926     }
3927 }
3928 
3929 
3930 /* Return true if hard REG is actually used in the some instruction.
3931    There are a fair number of conditions that affect the setting of
3932    this array.  See the comment in df.h for df->hard_regs_live_count
3933    for the conditions that this array is set. */
3934 
3935 bool
3936 df_hard_reg_used_p (unsigned int reg)
3937 {
3938   return df->hard_regs_live_count[reg] != 0;
3939 }
3940 
3941 
3942 /* A count of the number of times REG is actually used in the some
3943    instruction.  There are a fair number of conditions that affect the
3944    setting of this array.  See the comment in df.h for
3945    df->hard_regs_live_count for the conditions that this array is
3946    set. */
3947 
3948 
3949 unsigned int
3950 df_hard_reg_used_count (unsigned int reg)
3951 {
3952   return df->hard_regs_live_count[reg];
3953 }
3954 
3955 
3956 /* Get the value of regs_ever_live[REGNO].  */
3957 
3958 bool
3959 df_regs_ever_live_p (unsigned int regno)
3960 {
3961   return regs_ever_live[regno];
3962 }
3963 
3964 
3965 /* Set regs_ever_live[REGNO] to VALUE.  If this cause regs_ever_live
3966    to change, schedule that change for the next update.  */
3967 
3968 void
3969 df_set_regs_ever_live (unsigned int regno, bool value)
3970 {
3971   if (regs_ever_live[regno] == value)
3972     return;
3973 
3974   regs_ever_live[regno] = value;
3975   if (df)
3976     df->redo_entry_and_exit = true;
3977 }
3978 
3979 
3980 /* Compute "regs_ever_live" information from the underlying df
3981    information.  Set the vector to all false if RESET.  */
3982 
3983 void
3984 df_compute_regs_ever_live (bool reset)
3985 {
3986   unsigned int i;
3987   bool changed = df->redo_entry_and_exit;
3988 
3989   if (reset)
3990     memset (regs_ever_live, 0, sizeof (regs_ever_live));
3991 
3992   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3993     if ((!regs_ever_live[i]) && df_hard_reg_used_p (i))
3994       {
3995 	regs_ever_live[i] = true;
3996 	changed = true;
3997       }
3998   if (changed)
3999     df_update_entry_exit_and_calls ();
4000   df->redo_entry_and_exit = false;
4001 }
4002 
4003 
4004 /*----------------------------------------------------------------------------
4005   Dataflow ref information verification functions.
4006 
4007   df_reg_chain_mark (refs, regno, is_def, is_eq_use)
4008   df_reg_chain_verify_unmarked (refs)
4009   df_refs_verify (vec<stack, va_df_ref>, ref*, bool)
4010   df_mws_verify (mw*, mw*, bool)
4011   df_insn_refs_verify (collection_rec, bb, insn, bool)
4012   df_bb_refs_verify (bb, refs, bool)
4013   df_bb_verify (bb)
4014   df_exit_block_bitmap_verify (bool)
4015   df_entry_block_bitmap_verify (bool)
4016   df_scan_verify ()
4017 ----------------------------------------------------------------------------*/
4018 
4019 
4020 /* Mark all refs in the reg chain.  Verify that all of the registers
4021 are in the correct chain.  */
4022 
4023 static unsigned int
4024 df_reg_chain_mark (df_ref refs, unsigned int regno,
4025 		   bool is_def, bool is_eq_use)
4026 {
4027   unsigned int count = 0;
4028   df_ref ref;
4029   for (ref = refs; ref; ref = DF_REF_NEXT_REG (ref))
4030     {
4031       gcc_assert (!DF_REF_IS_REG_MARKED (ref));
4032 
4033       /* If there are no def-use or use-def chains, make sure that all
4034 	 of the chains are clear.  */
4035       if (!df_chain)
4036 	gcc_assert (!DF_REF_CHAIN (ref));
4037 
4038       /* Check to make sure the ref is in the correct chain.  */
4039       gcc_assert (DF_REF_REGNO (ref) == regno);
4040       if (is_def)
4041 	gcc_assert (DF_REF_REG_DEF_P (ref));
4042       else
4043 	gcc_assert (!DF_REF_REG_DEF_P (ref));
4044 
4045       if (is_eq_use)
4046 	gcc_assert ((DF_REF_FLAGS (ref) & DF_REF_IN_NOTE));
4047       else
4048 	gcc_assert ((DF_REF_FLAGS (ref) & DF_REF_IN_NOTE) == 0);
4049 
4050       if (DF_REF_NEXT_REG (ref))
4051 	gcc_assert (DF_REF_PREV_REG (DF_REF_NEXT_REG (ref)) == ref);
4052       count++;
4053       DF_REF_REG_MARK (ref);
4054     }
4055   return count;
4056 }
4057 
4058 
4059 /* Verify that all of the registers in the chain are unmarked.  */
4060 
4061 static void
4062 df_reg_chain_verify_unmarked (df_ref refs)
4063 {
4064   df_ref ref;
4065   for (ref = refs; ref; ref = DF_REF_NEXT_REG (ref))
4066     gcc_assert (!DF_REF_IS_REG_MARKED (ref));
4067 }
4068 
4069 
4070 /* Verify that NEW_REC and OLD_REC have exactly the same members. */
4071 
4072 static bool
4073 df_refs_verify (const vec<df_ref, va_heap> *new_rec, df_ref old_rec,
4074 		bool abort_if_fail)
4075 {
4076   unsigned int ix;
4077   df_ref new_ref;
4078 
4079   FOR_EACH_VEC_ELT (*new_rec, ix, new_ref)
4080     {
4081       if (old_rec == NULL || !df_ref_equal_p (new_ref, old_rec))
4082 	{
4083 	  if (abort_if_fail)
4084 	    gcc_assert (0);
4085 	  else
4086 	    return false;
4087 	}
4088 
4089       /* Abort if fail is called from the function level verifier.  If
4090 	 that is the context, mark this reg as being seem.  */
4091       if (abort_if_fail)
4092 	{
4093 	  gcc_assert (DF_REF_IS_REG_MARKED (old_rec));
4094 	  DF_REF_REG_UNMARK (old_rec);
4095 	}
4096 
4097       old_rec = DF_REF_NEXT_LOC (old_rec);
4098     }
4099 
4100   if (abort_if_fail)
4101     gcc_assert (old_rec == NULL);
4102   else
4103     return old_rec == NULL;
4104   return false;
4105 }
4106 
4107 
4108 /* Verify that NEW_REC and OLD_REC have exactly the same members. */
4109 
4110 static bool
4111 df_mws_verify (const vec<df_mw_hardreg_ptr, va_heap> *new_rec,
4112 	       struct df_mw_hardreg *old_rec,
4113 	       bool abort_if_fail)
4114 {
4115   unsigned int ix;
4116   struct df_mw_hardreg *new_reg;
4117 
4118   FOR_EACH_VEC_ELT (*new_rec, ix, new_reg)
4119     {
4120       if (old_rec == NULL || !df_mw_equal_p (new_reg, old_rec))
4121 	{
4122 	  if (abort_if_fail)
4123 	    gcc_assert (0);
4124 	  else
4125 	    return false;
4126 	}
4127       old_rec = DF_MWS_NEXT (old_rec);
4128     }
4129 
4130   if (abort_if_fail)
4131     gcc_assert (old_rec == NULL);
4132   else
4133     return old_rec == NULL;
4134   return false;
4135 }
4136 
4137 
4138 /* Return true if the existing insn refs information is complete and
4139    correct. Otherwise (i.e. if there's any missing or extra refs),
4140    return the correct df_ref chain in REFS_RETURN.
4141 
4142    If ABORT_IF_FAIL, leave the refs that are verified (already in the
4143    ref chain) as DF_REF_MARKED(). If it's false, then it's a per-insn
4144    verification mode instead of the whole function, so unmark
4145    everything.
4146 
4147    If ABORT_IF_FAIL is set, this function never returns false.  */
4148 
4149 static bool
4150 df_insn_refs_verify (struct df_collection_rec *collection_rec,
4151 		     basic_block bb,
4152                      rtx_insn *insn,
4153 		     bool abort_if_fail)
4154 {
4155   bool ret1, ret2, ret3, ret4;
4156   unsigned int uid = INSN_UID (insn);
4157   struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
4158 
4159   df_insn_refs_collect (collection_rec, bb, insn_info);
4160 
4161   /* Unfortunately we cannot opt out early if one of these is not
4162      right because the marks will not get cleared.  */
4163   ret1 = df_refs_verify (&collection_rec->def_vec, DF_INSN_UID_DEFS (uid),
4164 			 abort_if_fail);
4165   ret2 = df_refs_verify (&collection_rec->use_vec, DF_INSN_UID_USES (uid),
4166 			 abort_if_fail);
4167   ret3 = df_refs_verify (&collection_rec->eq_use_vec, DF_INSN_UID_EQ_USES (uid),
4168 			 abort_if_fail);
4169   ret4 = df_mws_verify (&collection_rec->mw_vec, DF_INSN_UID_MWS (uid),
4170 		       abort_if_fail);
4171   return (ret1 && ret2 && ret3 && ret4);
4172 }
4173 
4174 
4175 /* Return true if all refs in the basic block are correct and complete.
4176    Due to df_ref_chain_verify, it will cause all refs
4177    that are verified to have DF_REF_MARK bit set.  */
4178 
4179 static bool
4180 df_bb_verify (basic_block bb)
4181 {
4182   rtx_insn *insn;
4183   struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb->index);
4184   struct df_collection_rec collection_rec;
4185 
4186   gcc_assert (bb_info);
4187 
4188   /* Scan the block, one insn at a time, from beginning to end.  */
4189   FOR_BB_INSNS_REVERSE (bb, insn)
4190     {
4191       if (!INSN_P (insn))
4192         continue;
4193       df_insn_refs_verify (&collection_rec, bb, insn, true);
4194       df_free_collection_rec (&collection_rec);
4195     }
4196 
4197   /* Do the artificial defs and uses.  */
4198   df_bb_refs_collect (&collection_rec, bb);
4199   df_refs_verify (&collection_rec.def_vec, df_get_artificial_defs (bb->index), true);
4200   df_refs_verify (&collection_rec.use_vec, df_get_artificial_uses (bb->index), true);
4201   df_free_collection_rec (&collection_rec);
4202 
4203   return true;
4204 }
4205 
4206 
4207 /* Returns true if the entry block has correct and complete df_ref set.
4208    If not it either aborts if ABORT_IF_FAIL is true or returns false.  */
4209 
4210 static bool
4211 df_entry_block_bitmap_verify (bool abort_if_fail)
4212 {
4213   bitmap_head entry_block_defs;
4214   bool is_eq;
4215 
4216   bitmap_initialize (&entry_block_defs, &df_bitmap_obstack);
4217   df_get_entry_block_def_set (&entry_block_defs);
4218 
4219   is_eq = bitmap_equal_p (&entry_block_defs, df->entry_block_defs);
4220 
4221   if (!is_eq && abort_if_fail)
4222     {
4223       fprintf (stderr, "entry_block_defs = ");
4224       df_print_regset (stderr, &entry_block_defs);
4225       fprintf (stderr, "df->entry_block_defs = ");
4226       df_print_regset (stderr, df->entry_block_defs);
4227       gcc_assert (0);
4228     }
4229 
4230   bitmap_clear (&entry_block_defs);
4231 
4232   return is_eq;
4233 }
4234 
4235 
4236 /* Returns true if the exit block has correct and complete df_ref set.
4237    If not it either aborts if ABORT_IF_FAIL is true or returns false. */
4238 
4239 static bool
4240 df_exit_block_bitmap_verify (bool abort_if_fail)
4241 {
4242   bitmap_head exit_block_uses;
4243   bool is_eq;
4244 
4245   bitmap_initialize (&exit_block_uses, &df_bitmap_obstack);
4246   df_get_exit_block_use_set (&exit_block_uses);
4247 
4248   is_eq = bitmap_equal_p (&exit_block_uses, df->exit_block_uses);
4249 
4250   if (!is_eq && abort_if_fail)
4251     {
4252       fprintf (stderr, "exit_block_uses = ");
4253       df_print_regset (stderr, &exit_block_uses);
4254       fprintf (stderr, "df->exit_block_uses = ");
4255       df_print_regset (stderr, df->exit_block_uses);
4256       gcc_assert (0);
4257     }
4258 
4259   bitmap_clear (&exit_block_uses);
4260 
4261   return is_eq;
4262 }
4263 
4264 
4265 /* Return true if df_ref information for all insns in all blocks are
4266    correct and complete.  */
4267 
4268 void
4269 df_scan_verify (void)
4270 {
4271   unsigned int i;
4272   basic_block bb;
4273   bitmap_head regular_block_artificial_uses;
4274   bitmap_head eh_block_artificial_uses;
4275 
4276   if (!df)
4277     return;
4278 
4279   /* Verification is a 4 step process. */
4280 
4281   /* (1) All of the refs are marked by going through the reg chains.  */
4282   for (i = 0; i < DF_REG_SIZE (df); i++)
4283     {
4284       gcc_assert (df_reg_chain_mark (DF_REG_DEF_CHAIN (i), i, true, false)
4285 		  == DF_REG_DEF_COUNT (i));
4286       gcc_assert (df_reg_chain_mark (DF_REG_USE_CHAIN (i), i, false, false)
4287 		  == DF_REG_USE_COUNT (i));
4288       gcc_assert (df_reg_chain_mark (DF_REG_EQ_USE_CHAIN (i), i, false, true)
4289 		  == DF_REG_EQ_USE_COUNT (i));
4290     }
4291 
4292   /* (2) There are various bitmaps whose value may change over the
4293      course of the compilation.  This step recomputes them to make
4294      sure that they have not slipped out of date.  */
4295   bitmap_initialize (&regular_block_artificial_uses, &df_bitmap_obstack);
4296   bitmap_initialize (&eh_block_artificial_uses, &df_bitmap_obstack);
4297 
4298   df_get_regular_block_artificial_uses (&regular_block_artificial_uses);
4299   df_get_eh_block_artificial_uses (&eh_block_artificial_uses);
4300 
4301   bitmap_ior_into (&eh_block_artificial_uses,
4302 		   &regular_block_artificial_uses);
4303 
4304   /* Check artificial_uses bitmaps didn't change. */
4305   gcc_assert (bitmap_equal_p (&regular_block_artificial_uses,
4306 			      &df->regular_block_artificial_uses));
4307   gcc_assert (bitmap_equal_p (&eh_block_artificial_uses,
4308 			      &df->eh_block_artificial_uses));
4309 
4310   bitmap_clear (&regular_block_artificial_uses);
4311   bitmap_clear (&eh_block_artificial_uses);
4312 
4313   /* Verify entry block and exit block. These only verify the bitmaps,
4314      the refs are verified in df_bb_verify.  */
4315   df_entry_block_bitmap_verify (true);
4316   df_exit_block_bitmap_verify (true);
4317 
4318   /* (3) All of the insns in all of the blocks are traversed and the
4319      marks are cleared both in the artificial refs attached to the
4320      blocks and the real refs inside the insns.  It is a failure to
4321      clear a mark that has not been set as this means that the ref in
4322      the block or insn was not in the reg chain.  */
4323 
4324   FOR_ALL_BB_FN (bb, cfun)
4325     df_bb_verify (bb);
4326 
4327   /* (4) See if all reg chains are traversed a second time.  This time
4328      a check is made that the marks are clear. A set mark would be a
4329      from a reg that is not in any insn or basic block.  */
4330 
4331   for (i = 0; i < DF_REG_SIZE (df); i++)
4332     {
4333       df_reg_chain_verify_unmarked (DF_REG_DEF_CHAIN (i));
4334       df_reg_chain_verify_unmarked (DF_REG_USE_CHAIN (i));
4335       df_reg_chain_verify_unmarked (DF_REG_EQ_USE_CHAIN (i));
4336     }
4337 }
4338