xref: /dragonfly/contrib/gcc-8.0/gcc/df-scan.c (revision 3d33658b)
1 /* Scanning of rtl for dataflow analysis.
2    Copyright (C) 1999-2018 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 "backend.h"
28 #include "target.h"
29 #include "rtl.h"
30 #include "tree.h"
31 #include "df.h"
32 #include "memmodel.h"
33 #include "tm_p.h"
34 #include "regs.h"
35 #include "emit-rtl.h"  /* FIXME: Can go away once crtl is moved to rtl.h.  */
36 #include "dumpfile.h"
37 #include "calls.h"
38 
39 
40 /* The set of hard registers in eliminables[i].from. */
41 
42 static HARD_REG_SET elim_reg_set;
43 
44 /* Initialize ur_in and ur_out as if all hard registers were partially
45    available.  */
46 
47 struct df_collection_rec
48 {
49   auto_vec<df_ref, 128> def_vec;
50   auto_vec<df_ref, 32> use_vec;
51   auto_vec<df_ref, 32> eq_use_vec;
52   auto_vec<df_mw_hardreg *, 32> mw_vec;
53 };
54 
55 static void df_ref_record (enum df_ref_class, struct df_collection_rec *,
56 			   rtx, rtx *,
57 			   basic_block, struct df_insn_info *,
58 			   enum df_ref_type, int ref_flags);
59 static void df_def_record_1 (struct df_collection_rec *, rtx *,
60 			     basic_block, struct df_insn_info *,
61 			     int ref_flags);
62 static void df_defs_record (struct df_collection_rec *, rtx,
63 			    basic_block, struct df_insn_info *,
64 			    int ref_flags);
65 static void df_uses_record (struct df_collection_rec *,
66 			    rtx *, enum df_ref_type,
67 			    basic_block, struct df_insn_info *,
68 			    int ref_flags);
69 
70 static void df_install_ref_incremental (df_ref);
71 static void df_insn_refs_collect (struct df_collection_rec*,
72 				  basic_block, struct df_insn_info *);
73 static void df_canonize_collection_rec (struct df_collection_rec *);
74 
75 static void df_get_regular_block_artificial_uses (bitmap);
76 static void df_get_eh_block_artificial_uses (bitmap);
77 
78 static void df_record_entry_block_defs (bitmap);
79 static void df_record_exit_block_uses (bitmap);
80 static void df_get_exit_block_use_set (bitmap);
81 static void df_get_entry_block_def_set (bitmap);
82 static void df_grow_ref_info (struct df_ref_info *, unsigned int);
83 static void df_ref_chain_delete_du_chain (df_ref);
84 static void df_ref_chain_delete (df_ref);
85 
86 static void df_refs_add_to_chains (struct df_collection_rec *,
87 				   basic_block, rtx_insn *, unsigned int);
88 
89 static bool df_insn_refs_verify (struct df_collection_rec *, basic_block,
90 				 rtx_insn *, bool);
91 static void df_entry_block_defs_collect (struct df_collection_rec *, bitmap);
92 static void df_exit_block_uses_collect (struct df_collection_rec *, bitmap);
93 static void df_install_ref (df_ref, struct df_reg_info *,
94 			    struct df_ref_info *, bool);
95 
96 static int df_ref_compare (df_ref, df_ref);
97 static int df_ref_ptr_compare (const void *, const void *);
98 static int df_mw_compare (const df_mw_hardreg *, const df_mw_hardreg *);
99 static int df_mw_ptr_compare (const void *, const void *);
100 
101 static void df_insn_info_delete (unsigned int);
102 
103 /* Indexed by hardware reg number, is true if that register is ever
104    used in the current function.
105 
106    In df-scan.c, this is set up to record the hard regs used
107    explicitly.  Reload adds in the hard regs used for holding pseudo
108    regs.  Final uses it to generate the code in the function prologue
109    and epilogue to save and restore registers as needed.  */
110 
111 static bool regs_ever_live[FIRST_PSEUDO_REGISTER];
112 
113 /* Flags used to tell df_refs_add_to_chains() which vectors it should copy. */
114 static const unsigned int copy_defs = 0x1;
115 static const unsigned int copy_uses = 0x2;
116 static const unsigned int copy_eq_uses = 0x4;
117 static const unsigned int copy_mw = 0x8;
118 static const unsigned int copy_all = copy_defs | copy_uses | copy_eq_uses
119 | copy_mw;
120 
121 /*----------------------------------------------------------------------------
122    SCANNING DATAFLOW PROBLEM
123 
124    There are several ways in which scanning looks just like the other
125    dataflow problems.  It shares the all the mechanisms for local info
126    as well as basic block info.  Where it differs is when and how often
127    it gets run.  It also has no need for the iterative solver.
128 ----------------------------------------------------------------------------*/
129 
130 /* Problem data for the scanning dataflow function.  */
131 struct df_scan_problem_data
132 {
133   object_allocator<df_base_ref> *ref_base_pool;
134   object_allocator<df_artificial_ref> *ref_artificial_pool;
135   object_allocator<df_regular_ref> *ref_regular_pool;
136   object_allocator<df_insn_info> *insn_pool;
137   object_allocator<df_reg_info> *reg_pool;
138   object_allocator<df_mw_hardreg> *mw_reg_pool;
139 
140   bitmap_obstack reg_bitmaps;
141   bitmap_obstack insn_bitmaps;
142 };
143 
144 /* Internal function to shut down the scanning problem.  */
145 static void
146 df_scan_free_internal (void)
147 {
148   struct df_scan_problem_data *problem_data
149     = (struct df_scan_problem_data *) df_scan->problem_data;
150 
151   free (df->def_info.refs);
152   free (df->def_info.begin);
153   free (df->def_info.count);
154   memset (&df->def_info, 0, (sizeof (struct df_ref_info)));
155 
156   free (df->use_info.refs);
157   free (df->use_info.begin);
158   free (df->use_info.count);
159   memset (&df->use_info, 0, (sizeof (struct df_ref_info)));
160 
161   free (df->def_regs);
162   df->def_regs = NULL;
163   free (df->use_regs);
164   df->use_regs = NULL;
165   free (df->eq_use_regs);
166   df->eq_use_regs = NULL;
167   df->regs_size = 0;
168   DF_REG_SIZE (df) = 0;
169 
170   free (df->insns);
171   df->insns = NULL;
172   DF_INSN_SIZE () = 0;
173 
174   free (df_scan->block_info);
175   df_scan->block_info = NULL;
176   df_scan->block_info_size = 0;
177 
178   bitmap_clear (&df->hardware_regs_used);
179   bitmap_clear (&df->regular_block_artificial_uses);
180   bitmap_clear (&df->eh_block_artificial_uses);
181   BITMAP_FREE (df->entry_block_defs);
182   BITMAP_FREE (df->exit_block_uses);
183   bitmap_clear (&df->insns_to_delete);
184   bitmap_clear (&df->insns_to_rescan);
185   bitmap_clear (&df->insns_to_notes_rescan);
186 
187   delete problem_data->ref_base_pool;
188   delete problem_data->ref_artificial_pool;
189   delete problem_data->ref_regular_pool;
190   delete problem_data->insn_pool;
191   delete problem_data->reg_pool;
192   delete problem_data->mw_reg_pool;
193   bitmap_obstack_release (&problem_data->reg_bitmaps);
194   bitmap_obstack_release (&problem_data->insn_bitmaps);
195   free (df_scan->problem_data);
196 }
197 
198 
199 /* Free basic block info.  */
200 
201 static void
202 df_scan_free_bb_info (basic_block bb, void *vbb_info)
203 {
204   struct df_scan_bb_info *bb_info = (struct df_scan_bb_info *) vbb_info;
205   unsigned int bb_index = bb->index;
206   rtx_insn *insn;
207 
208   FOR_BB_INSNS (bb, insn)
209     if (INSN_P (insn))
210       df_insn_info_delete (INSN_UID (insn));
211 
212   if (bb_index < df_scan->block_info_size)
213     bb_info = df_scan_get_bb_info (bb_index);
214 
215   /* Get rid of any artificial uses or defs.  */
216   df_ref_chain_delete_du_chain (bb_info->artificial_defs);
217   df_ref_chain_delete_du_chain (bb_info->artificial_uses);
218   df_ref_chain_delete (bb_info->artificial_defs);
219   df_ref_chain_delete (bb_info->artificial_uses);
220   bb_info->artificial_defs = NULL;
221   bb_info->artificial_uses = NULL;
222 }
223 
224 
225 /* Allocate the problem data for the scanning problem.  This should be
226    called when the problem is created or when the entire function is to
227    be rescanned.  */
228 void
229 df_scan_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
230 {
231   struct df_scan_problem_data *problem_data;
232   unsigned int insn_num = get_max_uid () + 1;
233   basic_block bb;
234 
235   /* Given the number of pools, this is really faster than tearing
236      everything apart.  */
237   if (df_scan->problem_data)
238     df_scan_free_internal ();
239 
240   problem_data = XNEW (struct df_scan_problem_data);
241   df_scan->problem_data = problem_data;
242   df_scan->computed = true;
243 
244   problem_data->ref_base_pool = new object_allocator<df_base_ref>
245     ("df_scan ref base");
246   problem_data->ref_artificial_pool = new object_allocator<df_artificial_ref>
247     ("df_scan ref artificial");
248   problem_data->ref_regular_pool = new object_allocator<df_regular_ref>
249     ("df_scan ref regular");
250   problem_data->insn_pool = new object_allocator<df_insn_info>
251     ("df_scan insn");
252   problem_data->reg_pool = new object_allocator<df_reg_info>
253     ("df_scan reg");
254   problem_data->mw_reg_pool = new object_allocator<df_mw_hardreg>
255     ("df_scan mw_reg");
256 
257   bitmap_obstack_initialize (&problem_data->reg_bitmaps);
258   bitmap_obstack_initialize (&problem_data->insn_bitmaps);
259 
260   insn_num += insn_num / 4;
261   df_grow_reg_info ();
262 
263   df_grow_insn_info ();
264   df_grow_bb_info (df_scan);
265 
266   FOR_ALL_BB_FN (bb, cfun)
267     {
268       unsigned int bb_index = bb->index;
269       struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb_index);
270       bb_info->artificial_defs = NULL;
271       bb_info->artificial_uses = NULL;
272     }
273 
274   bitmap_initialize (&df->hardware_regs_used, &problem_data->reg_bitmaps);
275   bitmap_initialize (&df->regular_block_artificial_uses, &problem_data->reg_bitmaps);
276   bitmap_initialize (&df->eh_block_artificial_uses, &problem_data->reg_bitmaps);
277   df->entry_block_defs = BITMAP_ALLOC (&problem_data->reg_bitmaps);
278   df->exit_block_uses = BITMAP_ALLOC (&problem_data->reg_bitmaps);
279   bitmap_initialize (&df->insns_to_delete, &problem_data->insn_bitmaps);
280   bitmap_initialize (&df->insns_to_rescan, &problem_data->insn_bitmaps);
281   bitmap_initialize (&df->insns_to_notes_rescan, &problem_data->insn_bitmaps);
282   df_scan->optional_p = false;
283 }
284 
285 
286 /* Free all of the data associated with the scan problem.  */
287 
288 static void
289 df_scan_free (void)
290 {
291   if (df_scan->problem_data)
292     df_scan_free_internal ();
293 
294   if (df->blocks_to_analyze)
295     {
296       BITMAP_FREE (df->blocks_to_analyze);
297       df->blocks_to_analyze = NULL;
298     }
299 
300   free (df_scan);
301 }
302 
303 /* Dump the preamble for DF_SCAN dump. */
304 static void
305 df_scan_start_dump (FILE *file ATTRIBUTE_UNUSED)
306 {
307   int i;
308   int dcount = 0;
309   int ucount = 0;
310   int ecount = 0;
311   int icount = 0;
312   int ccount = 0;
313   basic_block bb;
314   rtx_insn *insn;
315 
316   fprintf (file, ";;  invalidated by call \t");
317   df_print_regset (file, regs_invalidated_by_call_regset);
318   fprintf (file, ";;  hardware regs used \t");
319   df_print_regset (file, &df->hardware_regs_used);
320   fprintf (file, ";;  regular block artificial uses \t");
321   df_print_regset (file, &df->regular_block_artificial_uses);
322   fprintf (file, ";;  eh block artificial uses \t");
323   df_print_regset (file, &df->eh_block_artificial_uses);
324   fprintf (file, ";;  entry block defs \t");
325   df_print_regset (file, df->entry_block_defs);
326   fprintf (file, ";;  exit block uses \t");
327   df_print_regset (file, df->exit_block_uses);
328   fprintf (file, ";;  regs ever live \t");
329   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
330     if (df_regs_ever_live_p (i))
331       fprintf (file, " %d [%s]", i, reg_names[i]);
332   fprintf (file, "\n;;  ref usage \t");
333 
334   for (i = 0; i < (int)df->regs_inited; i++)
335     if (DF_REG_DEF_COUNT (i) || DF_REG_USE_COUNT (i) || DF_REG_EQ_USE_COUNT (i))
336       {
337 	const char * sep = "";
338 
339 	fprintf (file, "r%d={", i);
340 	if (DF_REG_DEF_COUNT (i))
341 	  {
342 	    fprintf (file, "%dd", DF_REG_DEF_COUNT (i));
343 	    sep = ",";
344 	    dcount += DF_REG_DEF_COUNT (i);
345 	  }
346 	if (DF_REG_USE_COUNT (i))
347 	  {
348 	    fprintf (file, "%s%du", sep, DF_REG_USE_COUNT (i));
349 	    sep = ",";
350 	    ucount += DF_REG_USE_COUNT (i);
351 	  }
352 	if (DF_REG_EQ_USE_COUNT (i))
353 	  {
354 	    fprintf (file, "%s%de", sep, DF_REG_EQ_USE_COUNT (i));
355 	    ecount += DF_REG_EQ_USE_COUNT (i);
356 	  }
357 	fprintf (file, "} ");
358       }
359 
360   FOR_EACH_BB_FN (bb, cfun)
361     FOR_BB_INSNS (bb, insn)
362       if (INSN_P (insn))
363 	{
364 	  if (CALL_P (insn))
365 	    ccount++;
366 	  else
367 	    icount++;
368 	}
369 
370   fprintf (file, "\n;;    total ref usage %d{%dd,%du,%de}"
371 		 " in %d{%d regular + %d call} insns.\n",
372 		 dcount + ucount + ecount, dcount, ucount, ecount,
373 		 icount + ccount, icount, ccount);
374 }
375 
376 /* Dump the bb_info for a given basic block. */
377 static void
378 df_scan_start_block (basic_block bb, FILE *file)
379 {
380   struct df_scan_bb_info *bb_info
381     = df_scan_get_bb_info (bb->index);
382 
383   if (bb_info)
384     {
385       fprintf (file, ";; bb %d artificial_defs: ", bb->index);
386       df_refs_chain_dump (bb_info->artificial_defs, true, file);
387       fprintf (file, "\n;; bb %d artificial_uses: ", bb->index);
388       df_refs_chain_dump (bb_info->artificial_uses, true, file);
389       fprintf (file, "\n");
390     }
391 #if 0
392   {
393     rtx_insn *insn;
394     FOR_BB_INSNS (bb, insn)
395       if (INSN_P (insn))
396 	df_insn_debug (insn, false, file);
397   }
398 #endif
399 }
400 
401 static const struct df_problem problem_SCAN =
402 {
403   DF_SCAN,                    /* Problem id.  */
404   DF_NONE,                    /* Direction.  */
405   df_scan_alloc,              /* Allocate the problem specific data.  */
406   NULL,                       /* Reset global information.  */
407   df_scan_free_bb_info,       /* Free basic block info.  */
408   NULL,                       /* Local compute function.  */
409   NULL,                       /* Init the solution specific data.  */
410   NULL,                       /* Iterative solver.  */
411   NULL,                       /* Confluence operator 0.  */
412   NULL,                       /* Confluence operator n.  */
413   NULL,                       /* Transfer function.  */
414   NULL,                       /* Finalize function.  */
415   df_scan_free,               /* Free all of the problem information.  */
416   NULL,                       /* Remove this problem from the stack of dataflow problems.  */
417   df_scan_start_dump,         /* Debugging.  */
418   df_scan_start_block,        /* Debugging start block.  */
419   NULL,                       /* Debugging end block.  */
420   NULL,                       /* Debugging start insn.  */
421   NULL,                       /* Debugging end insn.  */
422   NULL,                       /* Incremental solution verify start.  */
423   NULL,                       /* Incremental solution verify end.  */
424   NULL,                       /* Dependent problem.  */
425   sizeof (struct df_scan_bb_info),/* Size of entry of block_info array.  */
426   TV_DF_SCAN,                 /* Timing variable.  */
427   false                       /* Reset blocks on dropping out of blocks_to_analyze.  */
428 };
429 
430 
431 /* Create a new DATAFLOW instance and add it to an existing instance
432    of DF.  The returned structure is what is used to get at the
433    solution.  */
434 
435 void
436 df_scan_add_problem (void)
437 {
438   df_add_problem (&problem_SCAN);
439 }
440 
441 
442 /*----------------------------------------------------------------------------
443    Storage Allocation Utilities
444 ----------------------------------------------------------------------------*/
445 
446 
447 /* First, grow the reg_info information.  If the current size is less than
448    the number of pseudos, grow to 25% more than the number of
449    pseudos.
450 
451    Second, assure that all of the slots up to max_reg_num have been
452    filled with reg_info structures.  */
453 
454 void
455 df_grow_reg_info (void)
456 {
457   unsigned int max_reg = max_reg_num ();
458   unsigned int new_size = max_reg;
459   struct df_scan_problem_data *problem_data
460     = (struct df_scan_problem_data *) df_scan->problem_data;
461   unsigned int i;
462 
463   if (df->regs_size < new_size)
464     {
465       new_size += new_size / 4;
466       df->def_regs = XRESIZEVEC (struct df_reg_info *, df->def_regs, new_size);
467       df->use_regs = XRESIZEVEC (struct df_reg_info *, df->use_regs, new_size);
468       df->eq_use_regs = XRESIZEVEC (struct df_reg_info *, df->eq_use_regs,
469 				    new_size);
470       df->def_info.begin = XRESIZEVEC (unsigned, df->def_info.begin, new_size);
471       df->def_info.count = XRESIZEVEC (unsigned, df->def_info.count, new_size);
472       df->use_info.begin = XRESIZEVEC (unsigned, df->use_info.begin, new_size);
473       df->use_info.count = XRESIZEVEC (unsigned, df->use_info.count, new_size);
474       df->regs_size = new_size;
475     }
476 
477   for (i = df->regs_inited; i < max_reg; i++)
478     {
479       struct df_reg_info *reg_info;
480 
481       // TODO
482       reg_info = problem_data->reg_pool->allocate ();
483       memset (reg_info, 0, sizeof (struct df_reg_info));
484       df->def_regs[i] = reg_info;
485       reg_info = problem_data->reg_pool->allocate ();
486       memset (reg_info, 0, sizeof (struct df_reg_info));
487       df->use_regs[i] = reg_info;
488       reg_info = problem_data->reg_pool->allocate ();
489       memset (reg_info, 0, sizeof (struct df_reg_info));
490       df->eq_use_regs[i] = reg_info;
491       df->def_info.begin[i] = 0;
492       df->def_info.count[i] = 0;
493       df->use_info.begin[i] = 0;
494       df->use_info.count[i] = 0;
495     }
496 
497   df->regs_inited = max_reg;
498 }
499 
500 
501 /* Grow the ref information.  */
502 
503 static void
504 df_grow_ref_info (struct df_ref_info *ref_info, unsigned int new_size)
505 {
506   if (ref_info->refs_size < new_size)
507     {
508       ref_info->refs = XRESIZEVEC (df_ref, ref_info->refs, new_size);
509       memset (ref_info->refs + ref_info->refs_size, 0,
510 	      (new_size - ref_info->refs_size) *sizeof (df_ref));
511       ref_info->refs_size = new_size;
512     }
513 }
514 
515 
516 /* Check and grow the ref information if necessary.  This routine
517    guarantees total_size + BITMAP_ADDEND amount of entries in refs
518    array.  It updates ref_info->refs_size only and does not change
519    ref_info->total_size.  */
520 
521 static void
522 df_check_and_grow_ref_info (struct df_ref_info *ref_info,
523 			    unsigned bitmap_addend)
524 {
525   if (ref_info->refs_size < ref_info->total_size + bitmap_addend)
526     {
527       int new_size = ref_info->total_size + bitmap_addend;
528       new_size += ref_info->total_size / 4;
529       df_grow_ref_info (ref_info, new_size);
530     }
531 }
532 
533 
534 /* Grow the ref information.  If the current size is less than the
535    number of instructions, grow to 25% more than the number of
536    instructions.  */
537 
538 void
539 df_grow_insn_info (void)
540 {
541   unsigned int new_size = get_max_uid () + 1;
542   if (DF_INSN_SIZE () < new_size)
543     {
544       new_size += new_size / 4;
545       df->insns = XRESIZEVEC (struct df_insn_info *, df->insns, new_size);
546       memset (df->insns + df->insns_size, 0,
547 	      (new_size - DF_INSN_SIZE ()) *sizeof (struct df_insn_info *));
548       DF_INSN_SIZE () = new_size;
549     }
550 }
551 
552 
553 
554 
555 /*----------------------------------------------------------------------------
556    PUBLIC INTERFACES FOR SMALL GRAIN CHANGES TO SCANNING.
557 ----------------------------------------------------------------------------*/
558 
559 /* Rescan all of the block_to_analyze or all of the blocks in the
560    function if df_set_blocks if blocks_to_analyze is NULL;  */
561 
562 void
563 df_scan_blocks (void)
564 {
565   basic_block bb;
566 
567   df->def_info.ref_order = DF_REF_ORDER_NO_TABLE;
568   df->use_info.ref_order = DF_REF_ORDER_NO_TABLE;
569 
570   df_get_regular_block_artificial_uses (&df->regular_block_artificial_uses);
571   df_get_eh_block_artificial_uses (&df->eh_block_artificial_uses);
572 
573   bitmap_ior_into (&df->eh_block_artificial_uses,
574 		   &df->regular_block_artificial_uses);
575 
576   /* ENTRY and EXIT blocks have special defs/uses.  */
577   df_get_entry_block_def_set (df->entry_block_defs);
578   df_record_entry_block_defs (df->entry_block_defs);
579   df_get_exit_block_use_set (df->exit_block_uses);
580   df_record_exit_block_uses (df->exit_block_uses);
581   df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK));
582   df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK));
583 
584   /* Regular blocks */
585   FOR_EACH_BB_FN (bb, cfun)
586     {
587       unsigned int bb_index = bb->index;
588       df_bb_refs_record (bb_index, true);
589     }
590 }
591 
592 /* Create new refs under address LOC within INSN.  This function is
593    only used externally.  REF_FLAGS must be either 0 or DF_REF_IN_NOTE,
594    depending on whether LOC is inside PATTERN (INSN) or a note.  */
595 
596 void
597 df_uses_create (rtx *loc, rtx_insn *insn, int ref_flags)
598 {
599   gcc_assert (!(ref_flags & ~DF_REF_IN_NOTE));
600   df_uses_record (NULL, loc, DF_REF_REG_USE,
601                   BLOCK_FOR_INSN (insn),
602                   DF_INSN_INFO_GET (insn),
603                   ref_flags);
604 }
605 
606 static void
607 df_install_ref_incremental (df_ref ref)
608 {
609   struct df_reg_info **reg_info;
610   struct df_ref_info *ref_info;
611   df_ref *ref_ptr;
612   bool add_to_table;
613 
614   rtx_insn *insn = DF_REF_INSN (ref);
615   basic_block bb = BLOCK_FOR_INSN (insn);
616 
617   if (DF_REF_REG_DEF_P (ref))
618     {
619       reg_info = df->def_regs;
620       ref_info = &df->def_info;
621       ref_ptr = &DF_INSN_DEFS (insn);
622       add_to_table = ref_info->ref_order != DF_REF_ORDER_NO_TABLE;
623     }
624   else if (DF_REF_FLAGS (ref) & DF_REF_IN_NOTE)
625     {
626       reg_info = df->eq_use_regs;
627       ref_info = &df->use_info;
628       ref_ptr = &DF_INSN_EQ_USES (insn);
629       switch (ref_info->ref_order)
630 	{
631 	case DF_REF_ORDER_UNORDERED_WITH_NOTES:
632 	case DF_REF_ORDER_BY_REG_WITH_NOTES:
633 	case DF_REF_ORDER_BY_INSN_WITH_NOTES:
634 	  add_to_table = true;
635 	  break;
636 	default:
637 	  add_to_table = false;
638 	  break;
639 	}
640     }
641   else
642     {
643       reg_info = df->use_regs;
644       ref_info = &df->use_info;
645       ref_ptr = &DF_INSN_USES (insn);
646       add_to_table = ref_info->ref_order != DF_REF_ORDER_NO_TABLE;
647     }
648 
649   /* Do not add if ref is not in the right blocks.  */
650   if (add_to_table && df->analyze_subset)
651     add_to_table = bitmap_bit_p (df->blocks_to_analyze, bb->index);
652 
653   df_install_ref (ref, reg_info[DF_REF_REGNO (ref)], ref_info, add_to_table);
654 
655   if (add_to_table)
656     switch (ref_info->ref_order)
657       {
658       case DF_REF_ORDER_UNORDERED_WITH_NOTES:
659       case DF_REF_ORDER_BY_REG_WITH_NOTES:
660       case DF_REF_ORDER_BY_INSN_WITH_NOTES:
661 	ref_info->ref_order = DF_REF_ORDER_UNORDERED_WITH_NOTES;
662 	break;
663       default:
664 	ref_info->ref_order = DF_REF_ORDER_UNORDERED;
665 	break;
666       }
667 
668   while (*ref_ptr && df_ref_compare (*ref_ptr, ref) < 0)
669     ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
670 
671   DF_REF_NEXT_LOC (ref) = *ref_ptr;
672   *ref_ptr = ref;
673 
674 #if 0
675   if (dump_file)
676     {
677       fprintf (dump_file, "adding ref ");
678       df_ref_debug (ref, dump_file);
679     }
680 #endif
681   /* By adding the ref directly, df_insn_rescan my not find any
682      differences even though the block will have changed.  So we need
683      to mark the block dirty ourselves.  */
684   if (!DEBUG_INSN_P (DF_REF_INSN (ref)))
685     df_set_bb_dirty (bb);
686 }
687 
688 
689 
690 /*----------------------------------------------------------------------------
691    UTILITIES TO CREATE AND DESTROY REFS AND CHAINS.
692 ----------------------------------------------------------------------------*/
693 
694 static void
695 df_free_ref (df_ref ref)
696 {
697   struct df_scan_problem_data *problem_data
698     = (struct df_scan_problem_data *) df_scan->problem_data;
699 
700   switch (DF_REF_CLASS (ref))
701     {
702     case DF_REF_BASE:
703       problem_data->ref_base_pool->remove ((df_base_ref *) (ref));
704       break;
705 
706     case DF_REF_ARTIFICIAL:
707       problem_data->ref_artificial_pool->remove
708 	((df_artificial_ref *) (ref));
709       break;
710 
711     case DF_REF_REGULAR:
712       problem_data->ref_regular_pool->remove
713 	((df_regular_ref *) (ref));
714       break;
715     }
716 }
717 
718 
719 /* Unlink and delete REF at the reg_use, reg_eq_use or reg_def chain.
720    Also delete the def-use or use-def chain if it exists.  */
721 
722 static void
723 df_reg_chain_unlink (df_ref ref)
724 {
725   df_ref next = DF_REF_NEXT_REG (ref);
726   df_ref prev = DF_REF_PREV_REG (ref);
727   int id = DF_REF_ID (ref);
728   struct df_reg_info *reg_info;
729   df_ref *refs = NULL;
730 
731   if (DF_REF_REG_DEF_P (ref))
732     {
733       int regno = DF_REF_REGNO (ref);
734       reg_info = DF_REG_DEF_GET (regno);
735       refs = df->def_info.refs;
736     }
737   else
738     {
739       if (DF_REF_FLAGS (ref) & DF_REF_IN_NOTE)
740 	{
741 	  reg_info = DF_REG_EQ_USE_GET (DF_REF_REGNO (ref));
742 	  switch (df->use_info.ref_order)
743 	    {
744 	    case DF_REF_ORDER_UNORDERED_WITH_NOTES:
745 	    case DF_REF_ORDER_BY_REG_WITH_NOTES:
746 	    case DF_REF_ORDER_BY_INSN_WITH_NOTES:
747 	      refs = df->use_info.refs;
748 	      break;
749 	    default:
750 	      break;
751 	    }
752 	}
753       else
754 	{
755 	  reg_info = DF_REG_USE_GET (DF_REF_REGNO (ref));
756 	  refs = df->use_info.refs;
757 	}
758     }
759 
760   if (refs)
761     {
762       if (df->analyze_subset)
763 	{
764 	  if (bitmap_bit_p (df->blocks_to_analyze, DF_REF_BBNO (ref)))
765 	    refs[id] = NULL;
766 	}
767       else
768 	refs[id] = NULL;
769     }
770 
771   /* Delete any def-use or use-def chains that start here. It is
772      possible that there is trash in this field.  This happens for
773      insns that have been deleted when rescanning has been deferred
774      and the chain problem has also been deleted.  The chain tear down
775      code skips deleted insns.  */
776   if (df_chain && DF_REF_CHAIN (ref))
777     df_chain_unlink (ref);
778 
779   reg_info->n_refs--;
780   if (DF_REF_FLAGS_IS_SET (ref, DF_HARD_REG_LIVE))
781     {
782       gcc_assert (DF_REF_REGNO (ref) < FIRST_PSEUDO_REGISTER);
783       df->hard_regs_live_count[DF_REF_REGNO (ref)]--;
784     }
785 
786   /* Unlink from the reg chain.  If there is no prev, this is the
787      first of the list.  If not, just join the next and prev.  */
788   if (prev)
789     DF_REF_NEXT_REG (prev) = next;
790   else
791     {
792       gcc_assert (reg_info->reg_chain == ref);
793       reg_info->reg_chain = next;
794     }
795   if (next)
796     DF_REF_PREV_REG (next) = prev;
797 
798   df_free_ref (ref);
799 }
800 
801 /* Initialize INSN_INFO to describe INSN.  */
802 
803 static void
804 df_insn_info_init_fields (df_insn_info *insn_info, rtx_insn *insn)
805 {
806   memset (insn_info, 0, sizeof (struct df_insn_info));
807   insn_info->insn = insn;
808 }
809 
810 /* Create the insn record for INSN.  If there was one there, zero it
811    out.  */
812 
813 struct df_insn_info *
814 df_insn_create_insn_record (rtx_insn *insn)
815 {
816   struct df_scan_problem_data *problem_data
817     = (struct df_scan_problem_data *) df_scan->problem_data;
818   struct df_insn_info *insn_rec;
819 
820   df_grow_insn_info ();
821   insn_rec = DF_INSN_INFO_GET (insn);
822   if (!insn_rec)
823     {
824       insn_rec = problem_data->insn_pool->allocate ();
825       DF_INSN_INFO_SET (insn, insn_rec);
826     }
827   df_insn_info_init_fields (insn_rec, insn);
828   return insn_rec;
829 }
830 
831 
832 /* Delete all du chain (DF_REF_CHAIN()) of all refs in the ref chain.  */
833 
834 static void
835 df_ref_chain_delete_du_chain (df_ref ref)
836 {
837   for (; ref; ref = DF_REF_NEXT_LOC (ref))
838     /* CHAIN is allocated by DF_CHAIN. So make sure to
839        pass df_scan instance for the problem.  */
840     if (DF_REF_CHAIN (ref))
841       df_chain_unlink (ref);
842 }
843 
844 
845 /* Delete all refs in the ref chain.  */
846 
847 static void
848 df_ref_chain_delete (df_ref ref)
849 {
850   df_ref next;
851   for (; ref; ref = next)
852     {
853       next = DF_REF_NEXT_LOC (ref);
854       df_reg_chain_unlink (ref);
855     }
856 }
857 
858 
859 /* Delete the hardreg chain.  */
860 
861 static void
862 df_mw_hardreg_chain_delete (struct df_mw_hardreg *hardregs)
863 {
864   struct df_scan_problem_data *problem_data
865     = (struct df_scan_problem_data *) df_scan->problem_data;
866   df_mw_hardreg *next;
867 
868   for (; hardregs; hardregs = next)
869     {
870       next = DF_MWS_NEXT (hardregs);
871       problem_data->mw_reg_pool->remove (hardregs);
872     }
873 }
874 
875 /* Remove the contents of INSN_INFO (but don't free INSN_INFO itself).  */
876 
877 static void
878 df_insn_info_free_fields (df_insn_info *insn_info)
879 {
880   /* In general, notes do not have the insn_info fields
881      initialized.  However, combine deletes insns by changing them
882      to notes.  How clever.  So we cannot just check if it is a
883      valid insn before short circuiting this code, we need to see
884      if we actually initialized it.  */
885   df_mw_hardreg_chain_delete (insn_info->mw_hardregs);
886 
887   if (df_chain)
888     {
889       df_ref_chain_delete_du_chain (insn_info->defs);
890       df_ref_chain_delete_du_chain (insn_info->uses);
891       df_ref_chain_delete_du_chain (insn_info->eq_uses);
892     }
893 
894   df_ref_chain_delete (insn_info->defs);
895   df_ref_chain_delete (insn_info->uses);
896   df_ref_chain_delete (insn_info->eq_uses);
897 }
898 
899 /* Delete all of the refs information from the insn with UID.
900    Internal helper for df_insn_delete, df_insn_rescan, and other
901    df-scan routines that don't have to work in deferred mode
902    and do not have to mark basic blocks for re-processing.  */
903 
904 static void
905 df_insn_info_delete (unsigned int uid)
906 {
907   struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
908 
909   bitmap_clear_bit (&df->insns_to_delete, uid);
910   bitmap_clear_bit (&df->insns_to_rescan, uid);
911   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
912   if (insn_info)
913     {
914       struct df_scan_problem_data *problem_data
915 	= (struct df_scan_problem_data *) df_scan->problem_data;
916 
917       df_insn_info_free_fields (insn_info);
918       problem_data->insn_pool->remove (insn_info);
919       DF_INSN_UID_SET (uid, NULL);
920     }
921 }
922 
923 /* Delete all of the refs information from INSN, either right now
924    or marked for later in deferred mode.  */
925 
926 void
927 df_insn_delete (rtx_insn *insn)
928 {
929   unsigned int uid;
930   basic_block bb;
931 
932   gcc_checking_assert (INSN_P (insn));
933 
934   if (!df)
935     return;
936 
937   uid = INSN_UID (insn);
938   bb = BLOCK_FOR_INSN (insn);
939 
940   /* ??? bb can be NULL after pass_free_cfg.  At that point, DF should
941      not exist anymore (as mentioned in df-core.c: "The only requirement
942      [for DF] is that there be a correct control flow graph."  Clearly
943      that isn't the case after pass_free_cfg.  But DF is freed much later
944      because some back-ends want to use DF info even though the CFG is
945      already gone.  It's not clear to me whether that is safe, actually.
946      In any case, we expect BB to be non-NULL at least up to register
947      allocation, so disallow a non-NULL BB up to there.  Not perfect
948      but better than nothing...  */
949   gcc_checking_assert (bb != NULL || reload_completed);
950 
951   df_grow_bb_info (df_scan);
952   df_grow_reg_info ();
953 
954   /* The block must be marked as dirty now, rather than later as in
955      df_insn_rescan and df_notes_rescan because it may not be there at
956      rescanning time and the mark would blow up.
957      DEBUG_INSNs do not make a block's data flow solution dirty (at
958      worst the LUIDs are no longer contiguous).  */
959   if (bb != NULL && NONDEBUG_INSN_P (insn))
960     df_set_bb_dirty (bb);
961 
962   /* The client has deferred rescanning.  */
963   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
964     {
965       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
966       if (insn_info)
967 	{
968 	  bitmap_clear_bit (&df->insns_to_rescan, uid);
969 	  bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
970 	  bitmap_set_bit (&df->insns_to_delete, uid);
971 	}
972       if (dump_file)
973 	fprintf (dump_file, "deferring deletion of insn with uid = %d.\n", uid);
974       return;
975     }
976 
977   if (dump_file)
978     fprintf (dump_file, "deleting insn with uid = %d.\n", uid);
979 
980   df_insn_info_delete (uid);
981 }
982 
983 
984 /* Free all of the refs and the mw_hardregs in COLLECTION_REC.  */
985 
986 static void
987 df_free_collection_rec (struct df_collection_rec *collection_rec)
988 {
989   unsigned int ix;
990   struct df_scan_problem_data *problem_data
991     = (struct df_scan_problem_data *) df_scan->problem_data;
992   df_ref ref;
993   struct df_mw_hardreg *mw;
994 
995   FOR_EACH_VEC_ELT (collection_rec->def_vec, ix, ref)
996     df_free_ref (ref);
997   FOR_EACH_VEC_ELT (collection_rec->use_vec, ix, ref)
998     df_free_ref (ref);
999   FOR_EACH_VEC_ELT (collection_rec->eq_use_vec, ix, ref)
1000     df_free_ref (ref);
1001   FOR_EACH_VEC_ELT (collection_rec->mw_vec, ix, mw)
1002     problem_data->mw_reg_pool->remove (mw);
1003 
1004   collection_rec->def_vec.release ();
1005   collection_rec->use_vec.release ();
1006   collection_rec->eq_use_vec.release ();
1007   collection_rec->mw_vec.release ();
1008 }
1009 
1010 /* Rescan INSN.  Return TRUE if the rescanning produced any changes.  */
1011 
1012 bool
1013 df_insn_rescan (rtx_insn *insn)
1014 {
1015   unsigned int uid = INSN_UID (insn);
1016   struct df_insn_info *insn_info = NULL;
1017   basic_block bb = BLOCK_FOR_INSN (insn);
1018   struct df_collection_rec collection_rec;
1019 
1020   if ((!df) || (!INSN_P (insn)))
1021     return false;
1022 
1023   if (!bb)
1024     {
1025       if (dump_file)
1026 	fprintf (dump_file, "no bb for insn with uid = %d.\n", uid);
1027       return false;
1028     }
1029 
1030   /* The client has disabled rescanning and plans to do it itself.  */
1031   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1032     return false;
1033 
1034   df_grow_bb_info (df_scan);
1035   df_grow_reg_info ();
1036 
1037   insn_info = DF_INSN_UID_SAFE_GET (uid);
1038 
1039   /* The client has deferred rescanning.  */
1040   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1041     {
1042       if (!insn_info)
1043 	{
1044 	  insn_info = df_insn_create_insn_record (insn);
1045 	  insn_info->defs = 0;
1046 	  insn_info->uses = 0;
1047 	  insn_info->eq_uses = 0;
1048 	  insn_info->mw_hardregs = 0;
1049 	}
1050       if (dump_file)
1051 	fprintf (dump_file, "deferring rescan insn with uid = %d.\n", uid);
1052 
1053       bitmap_clear_bit (&df->insns_to_delete, uid);
1054       bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1055       bitmap_set_bit (&df->insns_to_rescan, INSN_UID (insn));
1056       return false;
1057     }
1058 
1059   bitmap_clear_bit (&df->insns_to_delete, uid);
1060   bitmap_clear_bit (&df->insns_to_rescan, uid);
1061   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1062   if (insn_info)
1063     {
1064       int luid;
1065       bool the_same = df_insn_refs_verify (&collection_rec, bb, insn, false);
1066       /* If there's no change, return false. */
1067       if (the_same)
1068 	{
1069 	  df_free_collection_rec (&collection_rec);
1070 	  if (dump_file)
1071 	    fprintf (dump_file, "verify found no changes in insn with uid = %d.\n", uid);
1072 	  return false;
1073 	}
1074       if (dump_file)
1075 	fprintf (dump_file, "rescanning insn with uid = %d.\n", uid);
1076 
1077       /* There's change - we need to delete the existing info.
1078 	 Since the insn isn't moved, we can salvage its LUID.  */
1079       luid = DF_INSN_LUID (insn);
1080       df_insn_info_free_fields (insn_info);
1081       df_insn_info_init_fields (insn_info, insn);
1082       DF_INSN_LUID (insn) = luid;
1083     }
1084   else
1085     {
1086       struct df_insn_info *insn_info = df_insn_create_insn_record (insn);
1087       df_insn_refs_collect (&collection_rec, bb, insn_info);
1088       if (dump_file)
1089 	fprintf (dump_file, "scanning new insn with uid = %d.\n", uid);
1090     }
1091 
1092   df_refs_add_to_chains (&collection_rec, bb, insn, copy_all);
1093   if (!DEBUG_INSN_P (insn))
1094     df_set_bb_dirty (bb);
1095 
1096   return true;
1097 }
1098 
1099 /* Same as df_insn_rescan, but don't mark the basic block as
1100    dirty.  */
1101 
1102 bool
1103 df_insn_rescan_debug_internal (rtx_insn *insn)
1104 {
1105   unsigned int uid = INSN_UID (insn);
1106   struct df_insn_info *insn_info;
1107 
1108   gcc_assert (DEBUG_INSN_P (insn)
1109 	      && VAR_LOC_UNKNOWN_P (INSN_VAR_LOCATION_LOC (insn)));
1110 
1111   if (!df)
1112     return false;
1113 
1114   insn_info = DF_INSN_UID_SAFE_GET (INSN_UID (insn));
1115   if (!insn_info)
1116     return false;
1117 
1118   if (dump_file)
1119     fprintf (dump_file, "deleting debug_insn with uid = %d.\n", uid);
1120 
1121   bitmap_clear_bit (&df->insns_to_delete, uid);
1122   bitmap_clear_bit (&df->insns_to_rescan, uid);
1123   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1124 
1125   if (insn_info->defs == 0
1126       && insn_info->uses == 0
1127       && insn_info->eq_uses == 0
1128       && insn_info->mw_hardregs == 0)
1129     return false;
1130 
1131   df_mw_hardreg_chain_delete (insn_info->mw_hardregs);
1132 
1133   if (df_chain)
1134     {
1135       df_ref_chain_delete_du_chain (insn_info->defs);
1136       df_ref_chain_delete_du_chain (insn_info->uses);
1137       df_ref_chain_delete_du_chain (insn_info->eq_uses);
1138     }
1139 
1140   df_ref_chain_delete (insn_info->defs);
1141   df_ref_chain_delete (insn_info->uses);
1142   df_ref_chain_delete (insn_info->eq_uses);
1143 
1144   insn_info->defs = 0;
1145   insn_info->uses = 0;
1146   insn_info->eq_uses = 0;
1147   insn_info->mw_hardregs = 0;
1148 
1149   return true;
1150 }
1151 
1152 
1153 /* Rescan all of the insns in the function.  Note that the artificial
1154    uses and defs are not touched.  This function will destroy def-use
1155    or use-def chains.  */
1156 
1157 void
1158 df_insn_rescan_all (void)
1159 {
1160   bool no_insn_rescan = false;
1161   bool defer_insn_rescan = false;
1162   basic_block bb;
1163   bitmap_iterator bi;
1164   unsigned int uid;
1165 
1166   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1167     {
1168       df_clear_flags (DF_NO_INSN_RESCAN);
1169       no_insn_rescan = true;
1170     }
1171 
1172   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1173     {
1174       df_clear_flags (DF_DEFER_INSN_RESCAN);
1175       defer_insn_rescan = true;
1176     }
1177 
1178   auto_bitmap tmp (&df_bitmap_obstack);
1179   bitmap_copy (tmp, &df->insns_to_delete);
1180   EXECUTE_IF_SET_IN_BITMAP (tmp, 0, uid, bi)
1181     {
1182       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1183       if (insn_info)
1184 	df_insn_info_delete (uid);
1185     }
1186 
1187   bitmap_clear (&df->insns_to_delete);
1188   bitmap_clear (&df->insns_to_rescan);
1189   bitmap_clear (&df->insns_to_notes_rescan);
1190 
1191   FOR_EACH_BB_FN (bb, cfun)
1192     {
1193       rtx_insn *insn;
1194       FOR_BB_INSNS (bb, insn)
1195 	{
1196 	  df_insn_rescan (insn);
1197 	}
1198     }
1199 
1200   if (no_insn_rescan)
1201     df_set_flags (DF_NO_INSN_RESCAN);
1202   if (defer_insn_rescan)
1203     df_set_flags (DF_DEFER_INSN_RESCAN);
1204 }
1205 
1206 
1207 /* Process all of the deferred rescans or deletions.  */
1208 
1209 void
1210 df_process_deferred_rescans (void)
1211 {
1212   bool no_insn_rescan = false;
1213   bool defer_insn_rescan = false;
1214   bitmap_iterator bi;
1215   unsigned int uid;
1216 
1217   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1218     {
1219       df_clear_flags (DF_NO_INSN_RESCAN);
1220       no_insn_rescan = true;
1221     }
1222 
1223   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1224     {
1225       df_clear_flags (DF_DEFER_INSN_RESCAN);
1226       defer_insn_rescan = true;
1227     }
1228 
1229   if (dump_file)
1230     fprintf (dump_file, "starting the processing of deferred insns\n");
1231 
1232   auto_bitmap tmp (&df_bitmap_obstack);
1233   bitmap_copy (tmp, &df->insns_to_delete);
1234   EXECUTE_IF_SET_IN_BITMAP (tmp, 0, uid, bi)
1235     {
1236       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1237       if (insn_info)
1238 	df_insn_info_delete (uid);
1239     }
1240 
1241   bitmap_copy (tmp, &df->insns_to_rescan);
1242   EXECUTE_IF_SET_IN_BITMAP (tmp, 0, uid, bi)
1243     {
1244       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1245       if (insn_info)
1246 	df_insn_rescan (insn_info->insn);
1247     }
1248 
1249   bitmap_copy (tmp, &df->insns_to_notes_rescan);
1250   EXECUTE_IF_SET_IN_BITMAP (tmp, 0, uid, bi)
1251     {
1252       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1253       if (insn_info)
1254 	df_notes_rescan (insn_info->insn);
1255     }
1256 
1257   if (dump_file)
1258     fprintf (dump_file, "ending the processing of deferred insns\n");
1259 
1260   bitmap_clear (&df->insns_to_delete);
1261   bitmap_clear (&df->insns_to_rescan);
1262   bitmap_clear (&df->insns_to_notes_rescan);
1263 
1264   if (no_insn_rescan)
1265     df_set_flags (DF_NO_INSN_RESCAN);
1266   if (defer_insn_rescan)
1267     df_set_flags (DF_DEFER_INSN_RESCAN);
1268 
1269   /* If someone changed regs_ever_live during this pass, fix up the
1270      entry and exit blocks.  */
1271   if (df->redo_entry_and_exit)
1272     {
1273       df_update_entry_exit_and_calls ();
1274       df->redo_entry_and_exit = false;
1275     }
1276 }
1277 
1278 
1279 /* Count the number of refs. Include the defs if INCLUDE_DEFS. Include
1280    the uses if INCLUDE_USES. Include the eq_uses if
1281    INCLUDE_EQ_USES.  */
1282 
1283 static unsigned int
1284 df_count_refs (bool include_defs, bool include_uses,
1285 	       bool include_eq_uses)
1286 {
1287   unsigned int regno;
1288   int size = 0;
1289   unsigned int m = df->regs_inited;
1290 
1291   for (regno = 0; regno < m; regno++)
1292     {
1293       if (include_defs)
1294 	size += DF_REG_DEF_COUNT (regno);
1295       if (include_uses)
1296 	size += DF_REG_USE_COUNT (regno);
1297       if (include_eq_uses)
1298 	size += DF_REG_EQ_USE_COUNT (regno);
1299     }
1300   return size;
1301 }
1302 
1303 
1304 /* Take build ref table for either the uses or defs from the reg-use
1305    or reg-def chains.  This version processes the refs in reg order
1306    which is likely to be best if processing the whole function.  */
1307 
1308 static void
1309 df_reorganize_refs_by_reg_by_reg (struct df_ref_info *ref_info,
1310 				  bool include_defs,
1311 				  bool include_uses,
1312 				  bool include_eq_uses)
1313 {
1314   unsigned int m = df->regs_inited;
1315   unsigned int regno;
1316   unsigned int offset = 0;
1317   unsigned int start;
1318 
1319   if (df->changeable_flags & DF_NO_HARD_REGS)
1320     {
1321       start = FIRST_PSEUDO_REGISTER;
1322       memset (ref_info->begin, 0, sizeof (int) * FIRST_PSEUDO_REGISTER);
1323       memset (ref_info->count, 0, sizeof (int) * FIRST_PSEUDO_REGISTER);
1324     }
1325   else
1326     start = 0;
1327 
1328   ref_info->total_size
1329     = df_count_refs (include_defs, include_uses, include_eq_uses);
1330 
1331   df_check_and_grow_ref_info (ref_info, 1);
1332 
1333   for (regno = start; regno < m; regno++)
1334     {
1335       int count = 0;
1336       ref_info->begin[regno] = offset;
1337       if (include_defs)
1338 	{
1339 	  df_ref ref = DF_REG_DEF_CHAIN (regno);
1340 	  while (ref)
1341 	    {
1342 	      ref_info->refs[offset] = ref;
1343 	      DF_REF_ID (ref) = offset++;
1344 	      count++;
1345 	      ref = DF_REF_NEXT_REG (ref);
1346 	      gcc_checking_assert (offset < ref_info->refs_size);
1347 	    }
1348 	}
1349       if (include_uses)
1350 	{
1351 	  df_ref ref = DF_REG_USE_CHAIN (regno);
1352 	  while (ref)
1353 	    {
1354 	      ref_info->refs[offset] = ref;
1355 	      DF_REF_ID (ref) = offset++;
1356 	      count++;
1357 	      ref = DF_REF_NEXT_REG (ref);
1358 	      gcc_checking_assert (offset < ref_info->refs_size);
1359 	    }
1360 	}
1361       if (include_eq_uses)
1362 	{
1363 	  df_ref ref = DF_REG_EQ_USE_CHAIN (regno);
1364 	  while (ref)
1365 	    {
1366 	      ref_info->refs[offset] = ref;
1367 	      DF_REF_ID (ref) = offset++;
1368 	      count++;
1369 	      ref = DF_REF_NEXT_REG (ref);
1370 	      gcc_checking_assert (offset < ref_info->refs_size);
1371 	    }
1372 	}
1373       ref_info->count[regno] = count;
1374     }
1375 
1376   /* The bitmap size is not decremented when refs are deleted.  So
1377      reset it now that we have squished out all of the empty
1378      slots.  */
1379   ref_info->table_size = offset;
1380 }
1381 
1382 
1383 /* Take build ref table for either the uses or defs from the reg-use
1384    or reg-def chains.  This version processes the refs in insn order
1385    which is likely to be best if processing some segment of the
1386    function.  */
1387 
1388 static void
1389 df_reorganize_refs_by_reg_by_insn (struct df_ref_info *ref_info,
1390 				   bool include_defs,
1391 				   bool include_uses,
1392 				   bool include_eq_uses)
1393 {
1394   bitmap_iterator bi;
1395   unsigned int bb_index;
1396   unsigned int m = df->regs_inited;
1397   unsigned int offset = 0;
1398   unsigned int r;
1399   unsigned int start
1400     = (df->changeable_flags & DF_NO_HARD_REGS) ? FIRST_PSEUDO_REGISTER : 0;
1401 
1402   memset (ref_info->begin, 0, sizeof (int) * df->regs_inited);
1403   memset (ref_info->count, 0, sizeof (int) * df->regs_inited);
1404 
1405   ref_info->total_size = df_count_refs (include_defs, include_uses, include_eq_uses);
1406   df_check_and_grow_ref_info (ref_info, 1);
1407 
1408   EXECUTE_IF_SET_IN_BITMAP (df->blocks_to_analyze, 0, bb_index, bi)
1409     {
1410       basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
1411       rtx_insn *insn;
1412       df_ref def, use;
1413 
1414       if (include_defs)
1415 	FOR_EACH_ARTIFICIAL_DEF (def, bb_index)
1416 	  {
1417 	    unsigned int regno = DF_REF_REGNO (def);
1418 	    ref_info->count[regno]++;
1419 	  }
1420       if (include_uses)
1421 	FOR_EACH_ARTIFICIAL_USE (use, bb_index)
1422 	  {
1423 	    unsigned int regno = DF_REF_REGNO (use);
1424 	    ref_info->count[regno]++;
1425 	  }
1426 
1427       FOR_BB_INSNS (bb, insn)
1428 	{
1429 	  if (INSN_P (insn))
1430 	    {
1431 	      struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
1432 
1433 	      if (include_defs)
1434 		FOR_EACH_INSN_INFO_DEF (def, insn_info)
1435 		  {
1436 		    unsigned int regno = DF_REF_REGNO (def);
1437 		    ref_info->count[regno]++;
1438 		  }
1439 	      if (include_uses)
1440 		FOR_EACH_INSN_INFO_USE (use, insn_info)
1441 		  {
1442 		    unsigned int regno = DF_REF_REGNO (use);
1443 		    ref_info->count[regno]++;
1444 		  }
1445 	      if (include_eq_uses)
1446 		FOR_EACH_INSN_INFO_EQ_USE (use, insn_info)
1447 		  {
1448 		    unsigned int regno = DF_REF_REGNO (use);
1449 		    ref_info->count[regno]++;
1450 		  }
1451 	    }
1452 	}
1453     }
1454 
1455   for (r = start; r < m; r++)
1456     {
1457       ref_info->begin[r] = offset;
1458       offset += ref_info->count[r];
1459       ref_info->count[r] = 0;
1460     }
1461 
1462   EXECUTE_IF_SET_IN_BITMAP (df->blocks_to_analyze, 0, bb_index, bi)
1463     {
1464       basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
1465       rtx_insn *insn;
1466       df_ref def, use;
1467 
1468       if (include_defs)
1469 	FOR_EACH_ARTIFICIAL_DEF (def, bb_index)
1470 	  {
1471 	    unsigned int regno = DF_REF_REGNO (def);
1472 	    if (regno >= start)
1473 	      {
1474 		unsigned int id
1475 		  = ref_info->begin[regno] + ref_info->count[regno]++;
1476 		DF_REF_ID (def) = id;
1477 		ref_info->refs[id] = def;
1478 	      }
1479 	  }
1480       if (include_uses)
1481 	FOR_EACH_ARTIFICIAL_USE (use, bb_index)
1482 	  {
1483 	    unsigned int regno = DF_REF_REGNO (def);
1484 	    if (regno >= start)
1485 	      {
1486 		unsigned int id
1487 		  = ref_info->begin[regno] + ref_info->count[regno]++;
1488 		DF_REF_ID (use) = id;
1489 		ref_info->refs[id] = use;
1490 	      }
1491 	  }
1492 
1493       FOR_BB_INSNS (bb, insn)
1494 	{
1495 	  if (INSN_P (insn))
1496 	    {
1497 	      struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
1498 
1499 	      if (include_defs)
1500 		FOR_EACH_INSN_INFO_DEF (def, insn_info)
1501 		  {
1502 		    unsigned int regno = DF_REF_REGNO (def);
1503 		    if (regno >= start)
1504 		      {
1505 			unsigned int id
1506 			  = ref_info->begin[regno] + ref_info->count[regno]++;
1507 			DF_REF_ID (def) = id;
1508 			ref_info->refs[id] = def;
1509 		      }
1510 		  }
1511 	      if (include_uses)
1512 		FOR_EACH_INSN_INFO_USE (use, insn_info)
1513 		  {
1514 		    unsigned int regno = DF_REF_REGNO (use);
1515 		    if (regno >= start)
1516 		      {
1517 			unsigned int id
1518 			  = ref_info->begin[regno] + ref_info->count[regno]++;
1519 			DF_REF_ID (use) = id;
1520 			ref_info->refs[id] = use;
1521 		      }
1522 		  }
1523 	      if (include_eq_uses)
1524 		FOR_EACH_INSN_INFO_EQ_USE (use, insn_info)
1525 		  {
1526 		    unsigned int regno = DF_REF_REGNO (use);
1527 		    if (regno >= start)
1528 		      {
1529 			unsigned int id
1530 			  = ref_info->begin[regno] + ref_info->count[regno]++;
1531 			DF_REF_ID (use) = id;
1532 			ref_info->refs[id] = use;
1533 		      }
1534 		  }
1535 	    }
1536 	}
1537     }
1538 
1539   /* The bitmap size is not decremented when refs are deleted.  So
1540      reset it now that we have squished out all of the empty
1541      slots.  */
1542 
1543   ref_info->table_size = offset;
1544 }
1545 
1546 /* Take build ref table for either the uses or defs from the reg-use
1547    or reg-def chains.  */
1548 
1549 static void
1550 df_reorganize_refs_by_reg (struct df_ref_info *ref_info,
1551 			   bool include_defs,
1552 			   bool include_uses,
1553 			   bool include_eq_uses)
1554 {
1555   if (df->analyze_subset)
1556     df_reorganize_refs_by_reg_by_insn (ref_info, include_defs,
1557 				       include_uses, include_eq_uses);
1558   else
1559     df_reorganize_refs_by_reg_by_reg (ref_info, include_defs,
1560 				       include_uses, include_eq_uses);
1561 }
1562 
1563 
1564 /* Add the refs in REF_VEC to the table in REF_INFO starting at OFFSET.  */
1565 static unsigned int
1566 df_add_refs_to_table (unsigned int offset,
1567 		      struct df_ref_info *ref_info,
1568 		      df_ref ref)
1569 {
1570   for (; ref; ref = DF_REF_NEXT_LOC (ref))
1571     if (!(df->changeable_flags & DF_NO_HARD_REGS)
1572 	|| (DF_REF_REGNO (ref) >= FIRST_PSEUDO_REGISTER))
1573       {
1574 	ref_info->refs[offset] = ref;
1575 	DF_REF_ID (ref) = offset++;
1576       }
1577   return offset;
1578 }
1579 
1580 
1581 /* Count the number of refs in all of the insns of BB. Include the
1582    defs if INCLUDE_DEFS. Include the uses if INCLUDE_USES. Include the
1583    eq_uses if INCLUDE_EQ_USES.  */
1584 
1585 static unsigned int
1586 df_reorganize_refs_by_insn_bb (basic_block bb, unsigned int offset,
1587 			       struct df_ref_info *ref_info,
1588 			       bool include_defs, bool include_uses,
1589 			       bool include_eq_uses)
1590 {
1591   rtx_insn *insn;
1592 
1593   if (include_defs)
1594     offset = df_add_refs_to_table (offset, ref_info,
1595 				   df_get_artificial_defs (bb->index));
1596   if (include_uses)
1597     offset = df_add_refs_to_table (offset, ref_info,
1598 				   df_get_artificial_uses (bb->index));
1599 
1600   FOR_BB_INSNS (bb, insn)
1601     if (INSN_P (insn))
1602       {
1603 	unsigned int uid = INSN_UID (insn);
1604 	if (include_defs)
1605 	  offset = df_add_refs_to_table (offset, ref_info,
1606 					 DF_INSN_UID_DEFS (uid));
1607 	if (include_uses)
1608 	  offset = df_add_refs_to_table (offset, ref_info,
1609 					 DF_INSN_UID_USES (uid));
1610 	if (include_eq_uses)
1611 	  offset = df_add_refs_to_table (offset, ref_info,
1612 					 DF_INSN_UID_EQ_USES (uid));
1613       }
1614   return offset;
1615 }
1616 
1617 
1618 /* Organize the refs by insn into the table in REF_INFO.  If
1619    blocks_to_analyze is defined, use that set, otherwise the entire
1620    program.  Include the defs if INCLUDE_DEFS. Include the uses if
1621    INCLUDE_USES. Include the eq_uses if INCLUDE_EQ_USES.  */
1622 
1623 static void
1624 df_reorganize_refs_by_insn (struct df_ref_info *ref_info,
1625 			    bool include_defs, bool include_uses,
1626 			    bool include_eq_uses)
1627 {
1628   basic_block bb;
1629   unsigned int offset = 0;
1630 
1631   ref_info->total_size = df_count_refs (include_defs, include_uses, include_eq_uses);
1632   df_check_and_grow_ref_info (ref_info, 1);
1633   if (df->blocks_to_analyze)
1634     {
1635       bitmap_iterator bi;
1636       unsigned int index;
1637 
1638       EXECUTE_IF_SET_IN_BITMAP (df->blocks_to_analyze, 0, index, bi)
1639 	{
1640 	  offset = df_reorganize_refs_by_insn_bb (BASIC_BLOCK_FOR_FN (cfun,
1641 								      index),
1642 						  offset, ref_info,
1643 						  include_defs, include_uses,
1644 						  include_eq_uses);
1645 	}
1646 
1647       ref_info->table_size = offset;
1648     }
1649   else
1650     {
1651       FOR_ALL_BB_FN (bb, cfun)
1652 	offset = df_reorganize_refs_by_insn_bb (bb, offset, ref_info,
1653 						include_defs, include_uses,
1654 						include_eq_uses);
1655       ref_info->table_size = offset;
1656     }
1657 }
1658 
1659 
1660 /* If the use refs in DF are not organized, reorganize them.  */
1661 
1662 void
1663 df_maybe_reorganize_use_refs (enum df_ref_order order)
1664 {
1665   if (order == df->use_info.ref_order)
1666     return;
1667 
1668   switch (order)
1669     {
1670     case DF_REF_ORDER_BY_REG:
1671       df_reorganize_refs_by_reg (&df->use_info, false, true, false);
1672       break;
1673 
1674     case DF_REF_ORDER_BY_REG_WITH_NOTES:
1675       df_reorganize_refs_by_reg (&df->use_info, false, true, true);
1676       break;
1677 
1678     case DF_REF_ORDER_BY_INSN:
1679       df_reorganize_refs_by_insn (&df->use_info, false, true, false);
1680       break;
1681 
1682     case DF_REF_ORDER_BY_INSN_WITH_NOTES:
1683       df_reorganize_refs_by_insn (&df->use_info, false, true, true);
1684       break;
1685 
1686     case DF_REF_ORDER_NO_TABLE:
1687       free (df->use_info.refs);
1688       df->use_info.refs = NULL;
1689       df->use_info.refs_size = 0;
1690       break;
1691 
1692     case DF_REF_ORDER_UNORDERED:
1693     case DF_REF_ORDER_UNORDERED_WITH_NOTES:
1694       gcc_unreachable ();
1695       break;
1696     }
1697 
1698   df->use_info.ref_order = order;
1699 }
1700 
1701 
1702 /* If the def refs in DF are not organized, reorganize them.  */
1703 
1704 void
1705 df_maybe_reorganize_def_refs (enum df_ref_order order)
1706 {
1707   if (order == df->def_info.ref_order)
1708     return;
1709 
1710   switch (order)
1711     {
1712     case DF_REF_ORDER_BY_REG:
1713       df_reorganize_refs_by_reg (&df->def_info, true, false, false);
1714       break;
1715 
1716     case DF_REF_ORDER_BY_INSN:
1717       df_reorganize_refs_by_insn (&df->def_info, true, false, false);
1718       break;
1719 
1720     case DF_REF_ORDER_NO_TABLE:
1721       free (df->def_info.refs);
1722       df->def_info.refs = NULL;
1723       df->def_info.refs_size = 0;
1724       break;
1725 
1726     case DF_REF_ORDER_BY_INSN_WITH_NOTES:
1727     case DF_REF_ORDER_BY_REG_WITH_NOTES:
1728     case DF_REF_ORDER_UNORDERED:
1729     case DF_REF_ORDER_UNORDERED_WITH_NOTES:
1730       gcc_unreachable ();
1731       break;
1732     }
1733 
1734   df->def_info.ref_order = order;
1735 }
1736 
1737 
1738 /* Change all of the basic block references in INSN to use the insn's
1739    current basic block.  This function is called from routines that move
1740    instructions from one block to another.  */
1741 
1742 void
1743 df_insn_change_bb (rtx_insn *insn, basic_block new_bb)
1744 {
1745   basic_block old_bb = BLOCK_FOR_INSN (insn);
1746   struct df_insn_info *insn_info;
1747   unsigned int uid = INSN_UID (insn);
1748 
1749   if (old_bb == new_bb)
1750     return;
1751 
1752   set_block_for_insn (insn, new_bb);
1753 
1754   if (!df)
1755     return;
1756 
1757   if (dump_file)
1758     fprintf (dump_file, "changing bb of uid %d\n", uid);
1759 
1760   insn_info = DF_INSN_UID_SAFE_GET (uid);
1761   if (insn_info == NULL)
1762     {
1763       if (dump_file)
1764 	fprintf (dump_file, "  unscanned insn\n");
1765       df_insn_rescan (insn);
1766       return;
1767     }
1768 
1769   if (!INSN_P (insn))
1770     return;
1771 
1772   df_set_bb_dirty (new_bb);
1773   if (old_bb)
1774     {
1775       if (dump_file)
1776 	fprintf (dump_file, "  from %d to %d\n",
1777 		 old_bb->index, new_bb->index);
1778       df_set_bb_dirty (old_bb);
1779     }
1780   else
1781     if (dump_file)
1782       fprintf (dump_file, "  to %d\n", new_bb->index);
1783 }
1784 
1785 
1786 /* Helper function for df_ref_change_reg_with_loc.  */
1787 
1788 static void
1789 df_ref_change_reg_with_loc_1 (struct df_reg_info *old_df,
1790 			      struct df_reg_info *new_df,
1791 			      unsigned int new_regno, rtx loc)
1792 {
1793   df_ref the_ref = old_df->reg_chain;
1794 
1795   while (the_ref)
1796     {
1797       if ((!DF_REF_IS_ARTIFICIAL (the_ref))
1798 	  && DF_REF_LOC (the_ref)
1799 	  && (*DF_REF_LOC (the_ref) == loc))
1800 	{
1801 	  df_ref next_ref = DF_REF_NEXT_REG (the_ref);
1802 	  df_ref prev_ref = DF_REF_PREV_REG (the_ref);
1803 	  df_ref *ref_ptr;
1804 	  struct df_insn_info *insn_info = DF_REF_INSN_INFO (the_ref);
1805 
1806 	  DF_REF_REGNO (the_ref) = new_regno;
1807 	  DF_REF_REG (the_ref) = regno_reg_rtx[new_regno];
1808 
1809 	  /* Pull the_ref out of the old regno chain.  */
1810 	  if (prev_ref)
1811 	    DF_REF_NEXT_REG (prev_ref) = next_ref;
1812 	  else
1813 	    old_df->reg_chain = next_ref;
1814 	  if (next_ref)
1815 	    DF_REF_PREV_REG (next_ref) = prev_ref;
1816 	  old_df->n_refs--;
1817 
1818 	  /* Put the ref into the new regno chain.  */
1819 	  DF_REF_PREV_REG (the_ref) = NULL;
1820 	  DF_REF_NEXT_REG (the_ref) = new_df->reg_chain;
1821 	  if (new_df->reg_chain)
1822 	    DF_REF_PREV_REG (new_df->reg_chain) = the_ref;
1823 	  new_df->reg_chain = the_ref;
1824 	  new_df->n_refs++;
1825 	  if (DF_REF_BB (the_ref))
1826 	    df_set_bb_dirty (DF_REF_BB (the_ref));
1827 
1828 	  /* Need to sort the record again that the ref was in because
1829 	     the regno is a sorting key.  First, find the right
1830 	     record.  */
1831 	  if (DF_REF_REG_DEF_P (the_ref))
1832 	    ref_ptr = &insn_info->defs;
1833 	  else if (DF_REF_FLAGS (the_ref) & DF_REF_IN_NOTE)
1834 	    ref_ptr = &insn_info->eq_uses;
1835 	  else
1836 	    ref_ptr = &insn_info->uses;
1837 	  if (dump_file)
1838 	    fprintf (dump_file, "changing reg in insn %d\n",
1839 		     DF_REF_INSN_UID (the_ref));
1840 
1841 	  /* Stop if we find the current reference or where the reference
1842 	     needs to be.  */
1843 	  while (*ref_ptr != the_ref && df_ref_compare (*ref_ptr, the_ref) < 0)
1844 	    ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
1845 	  if (*ref_ptr != the_ref)
1846 	    {
1847 	      /* The reference needs to be promoted up the list.  */
1848 	      df_ref next = DF_REF_NEXT_LOC (the_ref);
1849 	      DF_REF_NEXT_LOC (the_ref) = *ref_ptr;
1850 	      *ref_ptr = the_ref;
1851 	      do
1852 		ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
1853 	      while (*ref_ptr != the_ref);
1854 	      *ref_ptr = next;
1855 	    }
1856 	  else if (DF_REF_NEXT_LOC (the_ref)
1857 		   && df_ref_compare (the_ref, DF_REF_NEXT_LOC (the_ref)) > 0)
1858 	    {
1859 	      /* The reference needs to be demoted down the list.  */
1860 	      *ref_ptr = DF_REF_NEXT_LOC (the_ref);
1861 	      do
1862 		ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
1863 	      while (*ref_ptr && df_ref_compare (the_ref, *ref_ptr) > 0);
1864 	      DF_REF_NEXT_LOC (the_ref) = *ref_ptr;
1865 	      *ref_ptr = the_ref;
1866 	    }
1867 
1868 	  the_ref = next_ref;
1869 	}
1870       else
1871 	the_ref = DF_REF_NEXT_REG (the_ref);
1872     }
1873 }
1874 
1875 
1876 /* Change the regno of register LOC to NEW_REGNO and update the df
1877    information accordingly.  Refs that do not match LOC are not changed
1878    which means that artificial refs are not changed since they have no loc.
1879    This call is to support the SET_REGNO macro. */
1880 
1881 void
1882 df_ref_change_reg_with_loc (rtx loc, unsigned int new_regno)
1883 {
1884   unsigned int old_regno = REGNO (loc);
1885   if (old_regno == new_regno)
1886     return;
1887 
1888   if (df)
1889     {
1890       df_grow_reg_info ();
1891 
1892       df_ref_change_reg_with_loc_1 (DF_REG_DEF_GET (old_regno),
1893 				    DF_REG_DEF_GET (new_regno),
1894 				    new_regno, loc);
1895       df_ref_change_reg_with_loc_1 (DF_REG_USE_GET (old_regno),
1896 				    DF_REG_USE_GET (new_regno),
1897 				    new_regno, loc);
1898       df_ref_change_reg_with_loc_1 (DF_REG_EQ_USE_GET (old_regno),
1899 				    DF_REG_EQ_USE_GET (new_regno),
1900 				    new_regno, loc);
1901     }
1902   set_mode_and_regno (loc, GET_MODE (loc), new_regno);
1903 }
1904 
1905 
1906 /* Delete the mw_hardregs that point into the eq_notes.  */
1907 
1908 static void
1909 df_mw_hardreg_chain_delete_eq_uses (struct df_insn_info *insn_info)
1910 {
1911   struct df_mw_hardreg **mw_ptr = &insn_info->mw_hardregs;
1912   struct df_scan_problem_data *problem_data
1913     = (struct df_scan_problem_data *) df_scan->problem_data;
1914 
1915   while (*mw_ptr)
1916     {
1917       df_mw_hardreg *mw = *mw_ptr;
1918       if (mw->flags & DF_REF_IN_NOTE)
1919 	{
1920 	  *mw_ptr = DF_MWS_NEXT (mw);
1921 	  problem_data->mw_reg_pool->remove (mw);
1922 	}
1923       else
1924 	mw_ptr = &DF_MWS_NEXT (mw);
1925     }
1926 }
1927 
1928 
1929 /* Rescan only the REG_EQUIV/REG_EQUAL notes part of INSN.  */
1930 
1931 void
1932 df_notes_rescan (rtx_insn *insn)
1933 {
1934   struct df_insn_info *insn_info;
1935   unsigned int uid = INSN_UID (insn);
1936 
1937   if (!df)
1938     return;
1939 
1940   /* The client has disabled rescanning and plans to do it itself.  */
1941   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1942     return;
1943 
1944   /* Do nothing if the insn hasn't been emitted yet.  */
1945   if (!BLOCK_FOR_INSN (insn))
1946     return;
1947 
1948   df_grow_bb_info (df_scan);
1949   df_grow_reg_info ();
1950 
1951   insn_info = DF_INSN_UID_SAFE_GET (INSN_UID (insn));
1952 
1953   /* The client has deferred rescanning.  */
1954   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1955     {
1956       if (!insn_info)
1957 	{
1958 	  insn_info = df_insn_create_insn_record (insn);
1959 	  insn_info->defs = 0;
1960 	  insn_info->uses = 0;
1961 	  insn_info->eq_uses = 0;
1962 	  insn_info->mw_hardregs = 0;
1963 	}
1964 
1965       bitmap_clear_bit (&df->insns_to_delete, uid);
1966       /* If the insn is set to be rescanned, it does not need to also
1967 	 be notes rescanned.  */
1968       if (!bitmap_bit_p (&df->insns_to_rescan, uid))
1969 	bitmap_set_bit (&df->insns_to_notes_rescan, INSN_UID (insn));
1970       return;
1971     }
1972 
1973   bitmap_clear_bit (&df->insns_to_delete, uid);
1974   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1975 
1976   if (insn_info)
1977     {
1978       basic_block bb = BLOCK_FOR_INSN (insn);
1979       rtx note;
1980       struct df_collection_rec collection_rec;
1981       unsigned int i;
1982 
1983       df_mw_hardreg_chain_delete_eq_uses (insn_info);
1984       df_ref_chain_delete (insn_info->eq_uses);
1985       insn_info->eq_uses = NULL;
1986 
1987       /* Process REG_EQUIV/REG_EQUAL notes */
1988       for (note = REG_NOTES (insn); note;
1989 	   note = XEXP (note, 1))
1990 	{
1991 	  switch (REG_NOTE_KIND (note))
1992 	    {
1993 	    case REG_EQUIV:
1994 	    case REG_EQUAL:
1995 	      df_uses_record (&collection_rec,
1996 			      &XEXP (note, 0), DF_REF_REG_USE,
1997 			      bb, insn_info, DF_REF_IN_NOTE);
1998 	    default:
1999 	      break;
2000 	    }
2001 	}
2002 
2003       /* Find some place to put any new mw_hardregs.  */
2004       df_canonize_collection_rec (&collection_rec);
2005       struct df_mw_hardreg **mw_ptr = &insn_info->mw_hardregs, *mw;
2006       FOR_EACH_VEC_ELT (collection_rec.mw_vec, i, mw)
2007 	{
2008 	  while (*mw_ptr && df_mw_compare (*mw_ptr, mw) < 0)
2009 	    mw_ptr = &DF_MWS_NEXT (*mw_ptr);
2010 	  DF_MWS_NEXT (mw) = *mw_ptr;
2011 	  *mw_ptr = mw;
2012 	  mw_ptr = &DF_MWS_NEXT (mw);
2013 	}
2014       df_refs_add_to_chains (&collection_rec, bb, insn, copy_eq_uses);
2015     }
2016   else
2017     df_insn_rescan (insn);
2018 
2019 }
2020 
2021 
2022 /*----------------------------------------------------------------------------
2023    Hard core instruction scanning code.  No external interfaces here,
2024    just a lot of routines that look inside insns.
2025 ----------------------------------------------------------------------------*/
2026 
2027 
2028 /* Return true if the contents of two df_ref's are identical.
2029    It ignores DF_REF_MARKER.  */
2030 
2031 static bool
2032 df_ref_equal_p (df_ref ref1, df_ref ref2)
2033 {
2034   if (!ref2)
2035     return false;
2036 
2037   if (ref1 == ref2)
2038     return true;
2039 
2040   if (DF_REF_CLASS (ref1) != DF_REF_CLASS (ref2)
2041       || DF_REF_REGNO (ref1) != DF_REF_REGNO (ref2)
2042       || DF_REF_REG (ref1) != DF_REF_REG (ref2)
2043       || DF_REF_TYPE (ref1) != DF_REF_TYPE (ref2)
2044       || ((DF_REF_FLAGS (ref1) & ~(DF_REF_REG_MARKER + DF_REF_MW_HARDREG))
2045 	  != (DF_REF_FLAGS (ref2) & ~(DF_REF_REG_MARKER + DF_REF_MW_HARDREG)))
2046       || DF_REF_BB (ref1) != DF_REF_BB (ref2)
2047       || DF_REF_INSN_INFO (ref1) != DF_REF_INSN_INFO (ref2))
2048     return false;
2049 
2050   switch (DF_REF_CLASS (ref1))
2051     {
2052     case DF_REF_ARTIFICIAL:
2053     case DF_REF_BASE:
2054       return true;
2055 
2056     case DF_REF_REGULAR:
2057       return DF_REF_LOC (ref1) == DF_REF_LOC (ref2);
2058 
2059     default:
2060       gcc_unreachable ();
2061     }
2062   return false;
2063 }
2064 
2065 
2066 /* Compare REF1 and REF2 for sorting.  This is only called from places
2067    where all of the refs are of the same type, in the same insn, and
2068    have the same bb.  So these fields are not checked.  */
2069 
2070 static int
2071 df_ref_compare (df_ref ref1, df_ref ref2)
2072 {
2073   if (DF_REF_CLASS (ref1) != DF_REF_CLASS (ref2))
2074     return (int)DF_REF_CLASS (ref1) - (int)DF_REF_CLASS (ref2);
2075 
2076   if (DF_REF_REGNO (ref1) != DF_REF_REGNO (ref2))
2077     return (int)DF_REF_REGNO (ref1) - (int)DF_REF_REGNO (ref2);
2078 
2079   if (DF_REF_TYPE (ref1) != DF_REF_TYPE (ref2))
2080     return (int)DF_REF_TYPE (ref1) - (int)DF_REF_TYPE (ref2);
2081 
2082   if (DF_REF_REG (ref1) != DF_REF_REG (ref2))
2083     return (int)DF_REF_ORDER (ref1) - (int)DF_REF_ORDER (ref2);
2084 
2085   /* Cannot look at the LOC field on artificial refs.  */
2086   if (DF_REF_CLASS (ref1) != DF_REF_ARTIFICIAL
2087       && DF_REF_LOC (ref1) != DF_REF_LOC (ref2))
2088     return (int)DF_REF_ORDER (ref1) - (int)DF_REF_ORDER (ref2);
2089 
2090   if (DF_REF_FLAGS (ref1) != DF_REF_FLAGS (ref2))
2091     {
2092       /* If two refs are identical except that one of them has is from
2093 	 a mw and one is not, we need to have the one with the mw
2094 	 first.  */
2095       if (DF_REF_FLAGS_IS_SET (ref1, DF_REF_MW_HARDREG) ==
2096 	  DF_REF_FLAGS_IS_SET (ref2, DF_REF_MW_HARDREG))
2097 	return DF_REF_FLAGS (ref1) - DF_REF_FLAGS (ref2);
2098       else if (DF_REF_FLAGS_IS_SET (ref1, DF_REF_MW_HARDREG))
2099 	return -1;
2100       else
2101 	return 1;
2102     }
2103 
2104   return (int)DF_REF_ORDER (ref1) - (int)DF_REF_ORDER (ref2);
2105 }
2106 
2107 /* Like df_ref_compare, but compare two df_ref* pointers R1 and R2.  */
2108 
2109 static int
2110 df_ref_ptr_compare (const void *r1, const void *r2)
2111 {
2112   return df_ref_compare (*(const df_ref *) r1, *(const df_ref *) r2);
2113 }
2114 
2115 /* Sort and compress a set of refs.  */
2116 
2117 static void
2118 df_sort_and_compress_refs (vec<df_ref, va_heap> *ref_vec)
2119 {
2120   unsigned int count;
2121   unsigned int i;
2122   unsigned int dist = 0;
2123 
2124   count = ref_vec->length ();
2125 
2126   /* If there are 1 or 0 elements, there is nothing to do.  */
2127   if (count < 2)
2128     return;
2129   else if (count == 2)
2130     {
2131       df_ref r0 = (*ref_vec)[0];
2132       df_ref r1 = (*ref_vec)[1];
2133       if (df_ref_compare (r0, r1) > 0)
2134 	std::swap ((*ref_vec)[0], (*ref_vec)[1]);
2135     }
2136   else
2137     {
2138       for (i = 0; i < count - 1; i++)
2139 	{
2140 	  df_ref r0 = (*ref_vec)[i];
2141 	  df_ref r1 = (*ref_vec)[i + 1];
2142 	  if (df_ref_compare (r0, r1) >= 0)
2143 	    break;
2144 	}
2145       /* If the array is already strictly ordered,
2146          which is the most common case for large COUNT case
2147          (which happens for CALL INSNs),
2148          no need to sort and filter out duplicate.
2149          Simply return the count.
2150          Make sure DF_GET_ADD_REFS adds refs in the increasing order
2151          of DF_REF_COMPARE.  */
2152       if (i == count - 1)
2153         return;
2154       ref_vec->qsort (df_ref_ptr_compare);
2155     }
2156 
2157   for (i=0; i<count-dist; i++)
2158     {
2159       /* Find the next ref that is not equal to the current ref.  */
2160       while (i + dist + 1 < count
2161 	     && df_ref_equal_p ((*ref_vec)[i],
2162 				(*ref_vec)[i + dist + 1]))
2163 	{
2164 	  df_free_ref ((*ref_vec)[i + dist + 1]);
2165 	  dist++;
2166 	}
2167       /* Copy it down to the next position.  */
2168       if (dist && i + dist + 1 < count)
2169 	(*ref_vec)[i + 1] = (*ref_vec)[i + dist + 1];
2170     }
2171 
2172   count -= dist;
2173   ref_vec->truncate (count);
2174 }
2175 
2176 
2177 /* Return true if the contents of two df_ref's are identical.
2178    It ignores DF_REF_MARKER.  */
2179 
2180 static bool
2181 df_mw_equal_p (struct df_mw_hardreg *mw1, struct df_mw_hardreg *mw2)
2182 {
2183   if (!mw2)
2184     return false;
2185   return (mw1 == mw2) ||
2186     (mw1->mw_reg == mw2->mw_reg
2187      && mw1->type == mw2->type
2188      && mw1->flags == mw2->flags
2189      && mw1->start_regno == mw2->start_regno
2190      && mw1->end_regno == mw2->end_regno);
2191 }
2192 
2193 
2194 /* Compare MW1 and MW2 for sorting.  */
2195 
2196 static int
2197 df_mw_compare (const df_mw_hardreg *mw1, const df_mw_hardreg *mw2)
2198 {
2199   if (mw1->type != mw2->type)
2200     return mw1->type - mw2->type;
2201 
2202   if (mw1->flags != mw2->flags)
2203     return mw1->flags - mw2->flags;
2204 
2205   if (mw1->start_regno != mw2->start_regno)
2206     return mw1->start_regno - mw2->start_regno;
2207 
2208   if (mw1->end_regno != mw2->end_regno)
2209     return mw1->end_regno - mw2->end_regno;
2210 
2211   if (mw1->mw_reg != mw2->mw_reg)
2212     return mw1->mw_order - mw2->mw_order;
2213 
2214   return 0;
2215 }
2216 
2217 /* Like df_mw_compare, but compare two df_mw_hardreg** pointers R1 and R2.  */
2218 
2219 static int
2220 df_mw_ptr_compare (const void *m1, const void *m2)
2221 {
2222   return df_mw_compare (*(const df_mw_hardreg *const *) m1,
2223 			*(const df_mw_hardreg *const *) m2);
2224 }
2225 
2226 /* Sort and compress a set of refs.  */
2227 
2228 static void
2229 df_sort_and_compress_mws (vec<df_mw_hardreg *, va_heap> *mw_vec)
2230 {
2231   unsigned int count;
2232   struct df_scan_problem_data *problem_data
2233     = (struct df_scan_problem_data *) df_scan->problem_data;
2234   unsigned int i;
2235   unsigned int dist = 0;
2236 
2237   count = mw_vec->length ();
2238   if (count < 2)
2239     return;
2240   else if (count == 2)
2241     {
2242       struct df_mw_hardreg *m0 = (*mw_vec)[0];
2243       struct df_mw_hardreg *m1 = (*mw_vec)[1];
2244       if (df_mw_compare (m0, m1) > 0)
2245         {
2246           struct df_mw_hardreg *tmp = (*mw_vec)[0];
2247 	  (*mw_vec)[0] = (*mw_vec)[1];
2248 	  (*mw_vec)[1] = tmp;
2249         }
2250     }
2251   else
2252     mw_vec->qsort (df_mw_ptr_compare);
2253 
2254   for (i=0; i<count-dist; i++)
2255     {
2256       /* Find the next ref that is not equal to the current ref.  */
2257       while (i + dist + 1 < count
2258 	     && df_mw_equal_p ((*mw_vec)[i], (*mw_vec)[i + dist + 1]))
2259 	{
2260 	  problem_data->mw_reg_pool->remove ((*mw_vec)[i + dist + 1]);
2261 	  dist++;
2262 	}
2263       /* Copy it down to the next position.  */
2264       if (dist && i + dist + 1 < count)
2265 	(*mw_vec)[i + 1] = (*mw_vec)[i + dist + 1];
2266     }
2267 
2268   count -= dist;
2269   mw_vec->truncate (count);
2270 }
2271 
2272 
2273 /* Sort and remove duplicates from the COLLECTION_REC.  */
2274 
2275 static void
2276 df_canonize_collection_rec (struct df_collection_rec *collection_rec)
2277 {
2278   df_sort_and_compress_refs (&collection_rec->def_vec);
2279   df_sort_and_compress_refs (&collection_rec->use_vec);
2280   df_sort_and_compress_refs (&collection_rec->eq_use_vec);
2281   df_sort_and_compress_mws (&collection_rec->mw_vec);
2282 }
2283 
2284 
2285 /* Add the new df_ref to appropriate reg_info/ref_info chains.  */
2286 
2287 static void
2288 df_install_ref (df_ref this_ref,
2289 		struct df_reg_info *reg_info,
2290 		struct df_ref_info *ref_info,
2291 		bool add_to_table)
2292 {
2293   unsigned int regno = DF_REF_REGNO (this_ref);
2294   /* Add the ref to the reg_{def,use,eq_use} chain.  */
2295   df_ref head = reg_info->reg_chain;
2296 
2297   reg_info->reg_chain = this_ref;
2298   reg_info->n_refs++;
2299 
2300   if (DF_REF_FLAGS_IS_SET (this_ref, DF_HARD_REG_LIVE))
2301     {
2302       gcc_assert (regno < FIRST_PSEUDO_REGISTER);
2303       df->hard_regs_live_count[regno]++;
2304     }
2305 
2306   gcc_checking_assert (DF_REF_NEXT_REG (this_ref) == NULL
2307 		       && DF_REF_PREV_REG (this_ref) == NULL);
2308 
2309   DF_REF_NEXT_REG (this_ref) = head;
2310 
2311   /* We cannot actually link to the head of the chain.  */
2312   DF_REF_PREV_REG (this_ref) = NULL;
2313 
2314   if (head)
2315     DF_REF_PREV_REG (head) = this_ref;
2316 
2317   if (add_to_table)
2318     {
2319       gcc_assert (ref_info->ref_order != DF_REF_ORDER_NO_TABLE);
2320       df_check_and_grow_ref_info (ref_info, 1);
2321       DF_REF_ID (this_ref) = ref_info->table_size;
2322       /* Add the ref to the big array of defs.  */
2323       ref_info->refs[ref_info->table_size] = this_ref;
2324       ref_info->table_size++;
2325     }
2326   else
2327     DF_REF_ID (this_ref) = -1;
2328 
2329   ref_info->total_size++;
2330 }
2331 
2332 
2333 /* This function takes one of the groups of refs (defs, uses or
2334    eq_uses) and installs the entire group into the insn.  It also adds
2335    each of these refs into the appropriate chains.  */
2336 
2337 static df_ref
2338 df_install_refs (basic_block bb,
2339 		 const vec<df_ref, va_heap> *old_vec,
2340 		 struct df_reg_info **reg_info,
2341 		 struct df_ref_info *ref_info,
2342 		 bool is_notes)
2343 {
2344   unsigned int count = old_vec->length ();
2345   if (count)
2346     {
2347       bool add_to_table;
2348       df_ref this_ref;
2349       unsigned int ix;
2350 
2351       switch (ref_info->ref_order)
2352 	{
2353 	case DF_REF_ORDER_UNORDERED_WITH_NOTES:
2354 	case DF_REF_ORDER_BY_REG_WITH_NOTES:
2355 	case DF_REF_ORDER_BY_INSN_WITH_NOTES:
2356 	  ref_info->ref_order = DF_REF_ORDER_UNORDERED_WITH_NOTES;
2357 	  add_to_table = true;
2358 	  break;
2359 	case DF_REF_ORDER_UNORDERED:
2360 	case DF_REF_ORDER_BY_REG:
2361 	case DF_REF_ORDER_BY_INSN:
2362 	  ref_info->ref_order = DF_REF_ORDER_UNORDERED;
2363 	  add_to_table = !is_notes;
2364 	  break;
2365 	default:
2366 	  add_to_table = false;
2367 	  break;
2368 	}
2369 
2370       /* Do not add if ref is not in the right blocks.  */
2371       if (add_to_table && df->analyze_subset)
2372 	add_to_table = bitmap_bit_p (df->blocks_to_analyze, bb->index);
2373 
2374       FOR_EACH_VEC_ELT (*old_vec, ix, this_ref)
2375 	{
2376 	  DF_REF_NEXT_LOC (this_ref) = (ix + 1 < old_vec->length ()
2377 					? (*old_vec)[ix + 1]
2378 					: NULL);
2379 	  df_install_ref (this_ref, reg_info[DF_REF_REGNO (this_ref)],
2380 			  ref_info, add_to_table);
2381 	}
2382       return (*old_vec)[0];
2383     }
2384   else
2385     return 0;
2386 }
2387 
2388 
2389 /* This function takes the mws installs the entire group into the
2390    insn.  */
2391 
2392 static struct df_mw_hardreg *
2393 df_install_mws (const vec<df_mw_hardreg *, va_heap> *old_vec)
2394 {
2395   unsigned int count = old_vec->length ();
2396   if (count)
2397     {
2398       for (unsigned int i = 0; i < count - 1; i++)
2399 	DF_MWS_NEXT ((*old_vec)[i]) = (*old_vec)[i + 1];
2400       DF_MWS_NEXT ((*old_vec)[count - 1]) = 0;
2401       return (*old_vec)[0];
2402     }
2403   else
2404     return 0;
2405 }
2406 
2407 
2408 /* Add a chain of df_refs to appropriate ref chain/reg_info/ref_info
2409    chains and update other necessary information.  */
2410 
2411 static void
2412 df_refs_add_to_chains (struct df_collection_rec *collection_rec,
2413 		       basic_block bb, rtx_insn *insn, unsigned int flags)
2414 {
2415   if (insn)
2416     {
2417       struct df_insn_info *insn_rec = DF_INSN_INFO_GET (insn);
2418       /* If there is a vector in the collection rec, add it to the
2419 	 insn.  A null rec is a signal that the caller will handle the
2420 	 chain specially.  */
2421       if (flags & copy_defs)
2422 	{
2423 	  gcc_checking_assert (!insn_rec->defs);
2424 	  insn_rec->defs
2425 	    = df_install_refs (bb, &collection_rec->def_vec,
2426 			       df->def_regs,
2427 			       &df->def_info, false);
2428 	}
2429       if (flags & copy_uses)
2430 	{
2431 	  gcc_checking_assert (!insn_rec->uses);
2432 	  insn_rec->uses
2433 	    = df_install_refs (bb, &collection_rec->use_vec,
2434 			       df->use_regs,
2435 			       &df->use_info, false);
2436 	}
2437       if (flags & copy_eq_uses)
2438 	{
2439 	  gcc_checking_assert (!insn_rec->eq_uses);
2440 	  insn_rec->eq_uses
2441 	    = df_install_refs (bb, &collection_rec->eq_use_vec,
2442 			       df->eq_use_regs,
2443 			       &df->use_info, true);
2444 	}
2445       if (flags & copy_mw)
2446 	{
2447 	  gcc_checking_assert (!insn_rec->mw_hardregs);
2448 	  insn_rec->mw_hardregs
2449 	    = df_install_mws (&collection_rec->mw_vec);
2450 	}
2451     }
2452   else
2453     {
2454       struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb->index);
2455 
2456       gcc_checking_assert (!bb_info->artificial_defs);
2457       bb_info->artificial_defs
2458 	= df_install_refs (bb, &collection_rec->def_vec,
2459 			   df->def_regs,
2460 			   &df->def_info, false);
2461       gcc_checking_assert (!bb_info->artificial_uses);
2462       bb_info->artificial_uses
2463 	= df_install_refs (bb, &collection_rec->use_vec,
2464 			   df->use_regs,
2465 			   &df->use_info, false);
2466     }
2467 }
2468 
2469 
2470 /* Allocate a ref and initialize its fields.  */
2471 
2472 static df_ref
2473 df_ref_create_structure (enum df_ref_class cl,
2474 			 struct df_collection_rec *collection_rec,
2475 			 rtx reg, rtx *loc,
2476 			 basic_block bb, struct df_insn_info *info,
2477 			 enum df_ref_type ref_type,
2478 			 int ref_flags)
2479 {
2480   df_ref this_ref = NULL;
2481   unsigned int regno = REGNO (GET_CODE (reg) == SUBREG ? SUBREG_REG (reg) : reg);
2482   struct df_scan_problem_data *problem_data
2483     = (struct df_scan_problem_data *) df_scan->problem_data;
2484 
2485   switch (cl)
2486     {
2487     case DF_REF_BASE:
2488       this_ref = (df_ref) (problem_data->ref_base_pool->allocate ());
2489       gcc_checking_assert (loc == NULL);
2490       break;
2491 
2492     case DF_REF_ARTIFICIAL:
2493       this_ref = (df_ref) (problem_data->ref_artificial_pool->allocate ());
2494       this_ref->artificial_ref.bb = bb;
2495       gcc_checking_assert (loc == NULL);
2496       break;
2497 
2498     case DF_REF_REGULAR:
2499       this_ref = (df_ref) (problem_data->ref_regular_pool->allocate ());
2500       this_ref->regular_ref.loc = loc;
2501       gcc_checking_assert (loc);
2502       break;
2503     }
2504 
2505   DF_REF_CLASS (this_ref) = cl;
2506   DF_REF_ID (this_ref) = -1;
2507   DF_REF_REG (this_ref) = reg;
2508   DF_REF_REGNO (this_ref) =  regno;
2509   DF_REF_TYPE (this_ref) = ref_type;
2510   DF_REF_INSN_INFO (this_ref) = info;
2511   DF_REF_CHAIN (this_ref) = NULL;
2512   DF_REF_FLAGS (this_ref) = ref_flags;
2513   DF_REF_NEXT_REG (this_ref) = NULL;
2514   DF_REF_PREV_REG (this_ref) = NULL;
2515   DF_REF_ORDER (this_ref) = df->ref_order++;
2516 
2517   /* We need to clear this bit because fwprop, and in the future
2518      possibly other optimizations sometimes create new refs using ond
2519      refs as the model.  */
2520   DF_REF_FLAGS_CLEAR (this_ref, DF_HARD_REG_LIVE);
2521 
2522   /* See if this ref needs to have DF_HARD_REG_LIVE bit set.  */
2523   if (regno < FIRST_PSEUDO_REGISTER
2524       && !DF_REF_IS_ARTIFICIAL (this_ref)
2525       && !DEBUG_INSN_P (DF_REF_INSN (this_ref)))
2526     {
2527       if (DF_REF_REG_DEF_P (this_ref))
2528 	{
2529 	  if (!DF_REF_FLAGS_IS_SET (this_ref, DF_REF_MAY_CLOBBER))
2530 	    DF_REF_FLAGS_SET (this_ref, DF_HARD_REG_LIVE);
2531 	}
2532       else if (!(TEST_HARD_REG_BIT (elim_reg_set, regno)
2533 		 && (regno == FRAME_POINTER_REGNUM
2534 		     || regno == ARG_POINTER_REGNUM)))
2535 	DF_REF_FLAGS_SET (this_ref, DF_HARD_REG_LIVE);
2536     }
2537 
2538   if (collection_rec)
2539     {
2540       if (DF_REF_REG_DEF_P (this_ref))
2541 	collection_rec->def_vec.safe_push (this_ref);
2542       else if (DF_REF_FLAGS (this_ref) & DF_REF_IN_NOTE)
2543 	collection_rec->eq_use_vec.safe_push (this_ref);
2544       else
2545 	collection_rec->use_vec.safe_push (this_ref);
2546     }
2547   else
2548     df_install_ref_incremental (this_ref);
2549 
2550   return this_ref;
2551 }
2552 
2553 
2554 /* Create new references of type DF_REF_TYPE for each part of register REG
2555    at address LOC within INSN of BB.  */
2556 
2557 
2558 static void
2559 df_ref_record (enum df_ref_class cl,
2560 	       struct df_collection_rec *collection_rec,
2561                rtx reg, rtx *loc,
2562 	       basic_block bb, struct df_insn_info *insn_info,
2563 	       enum df_ref_type ref_type,
2564 	       int ref_flags)
2565 {
2566   unsigned int regno;
2567 
2568   gcc_checking_assert (REG_P (reg) || GET_CODE (reg) == SUBREG);
2569 
2570   regno = REGNO (GET_CODE (reg) == SUBREG ? SUBREG_REG (reg) : reg);
2571   if (regno < FIRST_PSEUDO_REGISTER)
2572     {
2573       struct df_mw_hardreg *hardreg = NULL;
2574       struct df_scan_problem_data *problem_data
2575         = (struct df_scan_problem_data *) df_scan->problem_data;
2576       unsigned int i;
2577       unsigned int endregno;
2578       df_ref ref;
2579 
2580       if (GET_CODE (reg) == SUBREG)
2581 	{
2582 	  regno += subreg_regno_offset (regno, GET_MODE (SUBREG_REG (reg)),
2583 					SUBREG_BYTE (reg), GET_MODE (reg));
2584 	  endregno = regno + subreg_nregs (reg);
2585 	}
2586       else
2587 	endregno = END_REGNO (reg);
2588 
2589       /*  If this is a multiword hardreg, we create some extra
2590 	  datastructures that will enable us to easily build REG_DEAD
2591 	  and REG_UNUSED notes.  */
2592       if (collection_rec
2593 	  && (endregno != regno + 1) && insn_info)
2594 	{
2595 	  /* Sets to a subreg of a multiword register are partial.
2596 	     Sets to a non-subreg of a multiword register are not.  */
2597 	  if (GET_CODE (reg) == SUBREG)
2598 	    ref_flags |= DF_REF_PARTIAL;
2599 	  ref_flags |= DF_REF_MW_HARDREG;
2600 
2601 	  hardreg = problem_data->mw_reg_pool->allocate ();
2602 	  hardreg->type = ref_type;
2603 	  hardreg->flags = ref_flags;
2604 	  hardreg->mw_reg = reg;
2605 	  hardreg->start_regno = regno;
2606 	  hardreg->end_regno = endregno - 1;
2607 	  hardreg->mw_order = df->ref_order++;
2608 	  collection_rec->mw_vec.safe_push (hardreg);
2609 	}
2610 
2611       for (i = regno; i < endregno; i++)
2612 	{
2613 	  ref = df_ref_create_structure (cl, collection_rec, regno_reg_rtx[i], loc,
2614 					 bb, insn_info, ref_type, ref_flags);
2615 
2616           gcc_assert (ORIGINAL_REGNO (DF_REF_REG (ref)) == i);
2617 	}
2618     }
2619   else
2620     {
2621       df_ref_create_structure (cl, collection_rec, reg, loc, bb, insn_info,
2622 			       ref_type, ref_flags);
2623     }
2624 }
2625 
2626 
2627 /* Process all the registers defined in the rtx pointed by LOC.
2628    Autoincrement/decrement definitions will be picked up by df_uses_record.
2629    Any change here has to be matched in df_find_hard_reg_defs_1.  */
2630 
2631 static void
2632 df_def_record_1 (struct df_collection_rec *collection_rec,
2633                  rtx *loc, basic_block bb, struct df_insn_info *insn_info,
2634 		 int flags)
2635 {
2636   rtx dst = *loc;
2637 
2638   /* It is legal to have a set destination be a parallel. */
2639   if (GET_CODE (dst) == PARALLEL)
2640     {
2641       int i;
2642       for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
2643 	{
2644 	  rtx temp = XVECEXP (dst, 0, i);
2645 	  gcc_assert (GET_CODE (temp) == EXPR_LIST);
2646 	  df_def_record_1 (collection_rec, &XEXP (temp, 0),
2647 			   bb, insn_info, flags);
2648 	}
2649       return;
2650     }
2651 
2652   if (GET_CODE (dst) == STRICT_LOW_PART)
2653     {
2654       flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL | DF_REF_STRICT_LOW_PART;
2655 
2656       loc = &XEXP (dst, 0);
2657       dst = *loc;
2658     }
2659 
2660   if (GET_CODE (dst) == ZERO_EXTRACT)
2661     {
2662       flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL | DF_REF_ZERO_EXTRACT;
2663 
2664       loc = &XEXP (dst, 0);
2665       dst = *loc;
2666     }
2667 
2668   /* At this point if we do not have a reg or a subreg, just return.  */
2669   if (REG_P (dst))
2670     {
2671       df_ref_record (DF_REF_REGULAR, collection_rec,
2672 		     dst, loc, bb, insn_info, DF_REF_REG_DEF, flags);
2673 
2674       /* We want to keep sp alive everywhere - by making all
2675 	 writes to sp also use of sp. */
2676       if (REGNO (dst) == STACK_POINTER_REGNUM)
2677 	df_ref_record (DF_REF_BASE, collection_rec,
2678 		       dst, NULL, bb, insn_info, DF_REF_REG_USE, flags);
2679     }
2680   else if (GET_CODE (dst) == SUBREG && REG_P (SUBREG_REG (dst)))
2681     {
2682       if (read_modify_subreg_p (dst))
2683 	flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL;
2684 
2685       flags |= DF_REF_SUBREG;
2686 
2687       df_ref_record (DF_REF_REGULAR, collection_rec,
2688 		     dst, loc, bb, insn_info, DF_REF_REG_DEF, flags);
2689     }
2690 }
2691 
2692 
2693 /* Process all the registers defined in the pattern rtx, X.  Any change
2694    here has to be matched in df_find_hard_reg_defs.  */
2695 
2696 static void
2697 df_defs_record (struct df_collection_rec *collection_rec,
2698                 rtx x, basic_block bb, struct df_insn_info *insn_info,
2699 		int flags)
2700 {
2701   RTX_CODE code = GET_CODE (x);
2702   int i;
2703 
2704   switch (code)
2705     {
2706     case SET:
2707       df_def_record_1 (collection_rec, &SET_DEST (x), bb, insn_info, flags);
2708       break;
2709 
2710     case CLOBBER:
2711       flags |= DF_REF_MUST_CLOBBER;
2712       df_def_record_1 (collection_rec, &XEXP (x, 0), bb, insn_info, flags);
2713       break;
2714 
2715     case COND_EXEC:
2716       df_defs_record (collection_rec, COND_EXEC_CODE (x),
2717 		      bb, insn_info, DF_REF_CONDITIONAL);
2718       break;
2719 
2720     case PARALLEL:
2721       for (i = 0; i < XVECLEN (x, 0); i++)
2722 	df_defs_record (collection_rec, XVECEXP (x, 0, i),
2723 			bb, insn_info, flags);
2724       break;
2725     default:
2726       /* No DEFs to record in other cases */
2727       break;
2728     }
2729 }
2730 
2731 /* Set bits in *DEFS for hard registers found in the rtx DST, which is the
2732    destination of a set or clobber.  This has to match the logic in
2733    df_defs_record_1.  */
2734 
2735 static void
2736 df_find_hard_reg_defs_1 (rtx dst, HARD_REG_SET *defs)
2737 {
2738   /* It is legal to have a set destination be a parallel. */
2739   if (GET_CODE (dst) == PARALLEL)
2740     {
2741       int i;
2742       for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
2743 	{
2744 	  rtx temp = XVECEXP (dst, 0, i);
2745 	  gcc_assert (GET_CODE (temp) == EXPR_LIST);
2746 	  df_find_hard_reg_defs_1 (XEXP (temp, 0), defs);
2747 	}
2748       return;
2749     }
2750 
2751   if (GET_CODE (dst) == STRICT_LOW_PART)
2752       dst = XEXP (dst, 0);
2753 
2754   if (GET_CODE (dst) == ZERO_EXTRACT)
2755       dst = XEXP (dst, 0);
2756 
2757   /* At this point if we do not have a reg or a subreg, just return.  */
2758   if (REG_P (dst) && HARD_REGISTER_P (dst))
2759     SET_HARD_REG_BIT (*defs, REGNO (dst));
2760   else if (GET_CODE (dst) == SUBREG
2761 	   && REG_P (SUBREG_REG (dst)) && HARD_REGISTER_P (dst))
2762     SET_HARD_REG_BIT (*defs, REGNO (SUBREG_REG (dst)));
2763 }
2764 
2765 /* Set bits in *DEFS for hard registers defined in the pattern X.  This
2766    has to match the logic in df_defs_record.  */
2767 
2768 static void
2769 df_find_hard_reg_defs (rtx x, HARD_REG_SET *defs)
2770 {
2771   RTX_CODE code = GET_CODE (x);
2772   int i;
2773 
2774   switch (code)
2775     {
2776     case SET:
2777       df_find_hard_reg_defs_1 (SET_DEST (x), defs);
2778       break;
2779 
2780     case CLOBBER:
2781       df_find_hard_reg_defs_1 (XEXP (x, 0), defs);
2782       break;
2783 
2784     case COND_EXEC:
2785       df_find_hard_reg_defs (COND_EXEC_CODE (x), defs);
2786       break;
2787 
2788     case PARALLEL:
2789       for (i = 0; i < XVECLEN (x, 0); i++)
2790 	df_find_hard_reg_defs (XVECEXP (x, 0, i), defs);
2791       break;
2792     default:
2793       /* No DEFs to record in other cases */
2794       break;
2795     }
2796 }
2797 
2798 
2799 /* Process all the registers used in the rtx at address LOC.  */
2800 
2801 static void
2802 df_uses_record (struct df_collection_rec *collection_rec,
2803                 rtx *loc, enum df_ref_type ref_type,
2804 		basic_block bb, struct df_insn_info *insn_info,
2805 		int flags)
2806 {
2807   RTX_CODE code;
2808   rtx x;
2809 
2810  retry:
2811   x = *loc;
2812   if (!x)
2813     return;
2814   code = GET_CODE (x);
2815   switch (code)
2816     {
2817     case LABEL_REF:
2818     case SYMBOL_REF:
2819     case CONST:
2820     CASE_CONST_ANY:
2821     case PC:
2822     case CC0:
2823     case ADDR_VEC:
2824     case ADDR_DIFF_VEC:
2825       return;
2826 
2827     case CLOBBER:
2828       /* If we are clobbering a MEM, mark any registers inside the address
2829 	 as being used.  */
2830       if (MEM_P (XEXP (x, 0)))
2831 	df_uses_record (collection_rec,
2832 			&XEXP (XEXP (x, 0), 0),
2833 			DF_REF_REG_MEM_STORE,
2834 		        bb, insn_info,
2835 			flags);
2836 
2837       /* If we're clobbering a REG then we have a def so ignore.  */
2838       return;
2839 
2840     case MEM:
2841       df_uses_record (collection_rec,
2842 		      &XEXP (x, 0), DF_REF_REG_MEM_LOAD,
2843 		      bb, insn_info, flags & DF_REF_IN_NOTE);
2844       return;
2845 
2846     case SUBREG:
2847       /* While we're here, optimize this case.  */
2848       flags |= DF_REF_PARTIAL;
2849       /* In case the SUBREG is not of a REG, do not optimize.  */
2850       if (!REG_P (SUBREG_REG (x)))
2851 	{
2852 	  loc = &SUBREG_REG (x);
2853 	  df_uses_record (collection_rec, loc, ref_type, bb, insn_info, flags);
2854 	  return;
2855 	}
2856       /* Fall through */
2857 
2858     case REG:
2859       df_ref_record (DF_REF_REGULAR, collection_rec,
2860 		     x, loc, bb, insn_info,
2861 		     ref_type, flags);
2862       return;
2863 
2864     case SIGN_EXTRACT:
2865     case ZERO_EXTRACT:
2866       {
2867         df_uses_record (collection_rec,
2868                         &XEXP (x, 1), ref_type, bb, insn_info, flags);
2869         df_uses_record (collection_rec,
2870                         &XEXP (x, 2), ref_type, bb, insn_info, flags);
2871 
2872         /* If the parameters to the zero or sign extract are
2873            constants, strip them off and recurse, otherwise there is
2874            no information that we can gain from this operation.  */
2875         if (code == ZERO_EXTRACT)
2876           flags |= DF_REF_ZERO_EXTRACT;
2877         else
2878           flags |= DF_REF_SIGN_EXTRACT;
2879 
2880         df_uses_record (collection_rec,
2881                         &XEXP (x, 0), ref_type, bb, insn_info, flags);
2882         return;
2883       }
2884       break;
2885 
2886     case SET:
2887       {
2888 	rtx dst = SET_DEST (x);
2889 	gcc_assert (!(flags & DF_REF_IN_NOTE));
2890 	df_uses_record (collection_rec,
2891 			&SET_SRC (x), DF_REF_REG_USE, bb, insn_info, flags);
2892 
2893 	switch (GET_CODE (dst))
2894 	  {
2895 	    case SUBREG:
2896 	      if (read_modify_subreg_p (dst))
2897 		{
2898 		  df_uses_record (collection_rec, &SUBREG_REG (dst),
2899 				  DF_REF_REG_USE, bb, insn_info,
2900 				  flags | DF_REF_READ_WRITE | DF_REF_SUBREG);
2901 		  break;
2902 		}
2903 	      /* Fall through.  */
2904 	    case REG:
2905 	    case PARALLEL:
2906 	    case SCRATCH:
2907 	    case PC:
2908 	    case CC0:
2909 		break;
2910 	    case MEM:
2911 	      df_uses_record (collection_rec, &XEXP (dst, 0),
2912 			      DF_REF_REG_MEM_STORE, bb, insn_info, flags);
2913 	      break;
2914 	    case STRICT_LOW_PART:
2915 	      {
2916 		rtx *temp = &XEXP (dst, 0);
2917 		/* A strict_low_part uses the whole REG and not just the
2918 		 SUBREG.  */
2919 		dst = XEXP (dst, 0);
2920 		df_uses_record (collection_rec,
2921 				(GET_CODE (dst) == SUBREG) ? &SUBREG_REG (dst) : temp,
2922 				DF_REF_REG_USE, bb, insn_info,
2923 				DF_REF_READ_WRITE | DF_REF_STRICT_LOW_PART);
2924 	      }
2925 	      break;
2926 	    case ZERO_EXTRACT:
2927 	      {
2928 		df_uses_record (collection_rec, &XEXP (dst, 1),
2929 				DF_REF_REG_USE, bb, insn_info, flags);
2930 		df_uses_record (collection_rec, &XEXP (dst, 2),
2931 				DF_REF_REG_USE, bb, insn_info, flags);
2932                 if (GET_CODE (XEXP (dst,0)) == MEM)
2933                   df_uses_record (collection_rec, &XEXP (dst, 0),
2934                                   DF_REF_REG_USE, bb, insn_info,
2935                                   flags);
2936                 else
2937                   df_uses_record (collection_rec, &XEXP (dst, 0),
2938                                   DF_REF_REG_USE, bb, insn_info,
2939                                   DF_REF_READ_WRITE | DF_REF_ZERO_EXTRACT);
2940 	      }
2941 	      break;
2942 
2943 	    default:
2944 	      gcc_unreachable ();
2945 	  }
2946 	return;
2947       }
2948 
2949     case RETURN:
2950     case SIMPLE_RETURN:
2951       break;
2952 
2953     case ASM_OPERANDS:
2954     case UNSPEC_VOLATILE:
2955     case TRAP_IF:
2956     case ASM_INPUT:
2957       {
2958 	/* Traditional and volatile asm instructions must be
2959 	   considered to use and clobber all hard registers, all
2960 	   pseudo-registers and all of memory.  So must TRAP_IF and
2961 	   UNSPEC_VOLATILE operations.
2962 
2963 	   Consider for instance a volatile asm that changes the fpu
2964 	   rounding mode.  An insn should not be moved across this
2965 	   even if it only uses pseudo-regs because it might give an
2966 	   incorrectly rounded result.
2967 
2968 	   However, flow.c's liveness computation did *not* do this,
2969 	   giving the reasoning as " ?!? Unfortunately, marking all
2970 	   hard registers as live causes massive problems for the
2971 	   register allocator and marking all pseudos as live creates
2972 	   mountains of uninitialized variable warnings."
2973 
2974 	   In order to maintain the status quo with regard to liveness
2975 	   and uses, we do what flow.c did and just mark any regs we
2976 	   can find in ASM_OPERANDS as used.  In global asm insns are
2977 	   scanned and regs_asm_clobbered is filled out.
2978 
2979 	   For all ASM_OPERANDS, we must traverse the vector of input
2980 	   operands.  We can not just fall through here since then we
2981 	   would be confused by the ASM_INPUT rtx inside ASM_OPERANDS,
2982 	   which do not indicate traditional asms unlike their normal
2983 	   usage.  */
2984 	if (code == ASM_OPERANDS)
2985 	  {
2986 	    int j;
2987 
2988 	    for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++)
2989 	      df_uses_record (collection_rec, &ASM_OPERANDS_INPUT (x, j),
2990 			      DF_REF_REG_USE, bb, insn_info, flags);
2991 	    return;
2992 	  }
2993 	break;
2994       }
2995 
2996     case VAR_LOCATION:
2997       df_uses_record (collection_rec,
2998 		      &PAT_VAR_LOCATION_LOC (x),
2999 		      DF_REF_REG_USE, bb, insn_info, flags);
3000       return;
3001 
3002     case PRE_DEC:
3003     case POST_DEC:
3004     case PRE_INC:
3005     case POST_INC:
3006     case PRE_MODIFY:
3007     case POST_MODIFY:
3008       gcc_assert (!DEBUG_INSN_P (insn_info->insn));
3009       /* Catch the def of the register being modified.  */
3010       df_ref_record (DF_REF_REGULAR, collection_rec, XEXP (x, 0), &XEXP (x, 0),
3011 		     bb, insn_info,
3012 		     DF_REF_REG_DEF,
3013                      flags | DF_REF_READ_WRITE | DF_REF_PRE_POST_MODIFY);
3014 
3015       /* ... Fall through to handle uses ...  */
3016 
3017     default:
3018       break;
3019     }
3020 
3021   /* Recursively scan the operands of this expression.  */
3022   {
3023     const char *fmt = GET_RTX_FORMAT (code);
3024     int i;
3025 
3026     for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3027       {
3028 	if (fmt[i] == 'e')
3029 	  {
3030 	    /* Tail recursive case: save a function call level.  */
3031 	    if (i == 0)
3032 	      {
3033 		loc = &XEXP (x, 0);
3034 		goto retry;
3035 	      }
3036 	    df_uses_record (collection_rec, &XEXP (x, i), ref_type,
3037 			    bb, insn_info, flags);
3038 	  }
3039 	else if (fmt[i] == 'E')
3040 	  {
3041 	    int j;
3042 	    for (j = 0; j < XVECLEN (x, i); j++)
3043 	      df_uses_record (collection_rec,
3044 			      &XVECEXP (x, i, j), ref_type,
3045 			      bb, insn_info, flags);
3046 	  }
3047       }
3048   }
3049 
3050   return;
3051 }
3052 
3053 
3054 /* For all DF_REF_CONDITIONAL defs, add a corresponding uses.  */
3055 
3056 static void
3057 df_get_conditional_uses (struct df_collection_rec *collection_rec)
3058 {
3059   unsigned int ix;
3060   df_ref ref;
3061 
3062   FOR_EACH_VEC_ELT (collection_rec->def_vec, ix, ref)
3063     {
3064       if (DF_REF_FLAGS_IS_SET (ref, DF_REF_CONDITIONAL))
3065         {
3066           df_ref use;
3067 
3068           use = df_ref_create_structure (DF_REF_CLASS (ref), collection_rec, DF_REF_REG (ref),
3069 					 DF_REF_LOC (ref), DF_REF_BB (ref),
3070 					 DF_REF_INSN_INFO (ref), DF_REF_REG_USE,
3071 					 DF_REF_FLAGS (ref) & ~DF_REF_CONDITIONAL);
3072           DF_REF_REGNO (use) = DF_REF_REGNO (ref);
3073         }
3074     }
3075 }
3076 
3077 
3078 /* Get call's extra defs and uses (track caller-saved registers). */
3079 
3080 static void
3081 df_get_call_refs (struct df_collection_rec *collection_rec,
3082                   basic_block bb,
3083                   struct df_insn_info *insn_info,
3084                   int flags)
3085 {
3086   rtx note;
3087   bool is_sibling_call;
3088   unsigned int i;
3089   HARD_REG_SET defs_generated;
3090   HARD_REG_SET fn_reg_set_usage;
3091 
3092   CLEAR_HARD_REG_SET (defs_generated);
3093   df_find_hard_reg_defs (PATTERN (insn_info->insn), &defs_generated);
3094   is_sibling_call = SIBLING_CALL_P (insn_info->insn);
3095   get_call_reg_set_usage (insn_info->insn, &fn_reg_set_usage,
3096 			  regs_invalidated_by_call);
3097 
3098   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3099     {
3100       if (i == STACK_POINTER_REGNUM)
3101 	/* The stack ptr is used (honorarily) by a CALL insn.  */
3102 	df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3103 		       NULL, bb, insn_info, DF_REF_REG_USE,
3104 		       DF_REF_CALL_STACK_USAGE | flags);
3105       else if (global_regs[i])
3106 	{
3107 	  /* Calls to const functions cannot access any global registers and
3108 	     calls to pure functions cannot set them.  All other calls may
3109 	     reference any of the global registers, so they are recorded as
3110 	     used. */
3111 	  if (!RTL_CONST_CALL_P (insn_info->insn))
3112 	    {
3113 	      df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3114 			     NULL, bb, insn_info, DF_REF_REG_USE, flags);
3115 	      if (!RTL_PURE_CALL_P (insn_info->insn))
3116 		df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3117 			       NULL, bb, insn_info, DF_REF_REG_DEF, flags);
3118 	    }
3119 	}
3120       else if (TEST_HARD_REG_BIT (fn_reg_set_usage, i)
3121 	       /* no clobbers for regs that are the result of the call */
3122 	       && !TEST_HARD_REG_BIT (defs_generated, i)
3123 	       && (!is_sibling_call
3124 		   || !bitmap_bit_p (df->exit_block_uses, i)
3125 		   || refers_to_regno_p (i, crtl->return_rtx)))
3126 	  df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3127 			 NULL, bb, insn_info, DF_REF_REG_DEF,
3128 			 DF_REF_MAY_CLOBBER | flags);
3129     }
3130 
3131   /* Record the registers used to pass arguments, and explicitly
3132      noted as clobbered.  */
3133   for (note = CALL_INSN_FUNCTION_USAGE (insn_info->insn); note;
3134        note = XEXP (note, 1))
3135     {
3136       if (GET_CODE (XEXP (note, 0)) == USE)
3137         df_uses_record (collection_rec, &XEXP (XEXP (note, 0), 0),
3138 			DF_REF_REG_USE, bb, insn_info, flags);
3139       else if (GET_CODE (XEXP (note, 0)) == CLOBBER)
3140 	{
3141 	  if (REG_P (XEXP (XEXP (note, 0), 0)))
3142 	    {
3143 	      unsigned int regno = REGNO (XEXP (XEXP (note, 0), 0));
3144 	      if (!TEST_HARD_REG_BIT (defs_generated, regno))
3145 		df_defs_record (collection_rec, XEXP (note, 0), bb,
3146 				insn_info, flags);
3147 	    }
3148 	  else
3149 	    df_uses_record (collection_rec, &XEXP (note, 0),
3150 		            DF_REF_REG_USE, bb, insn_info, flags);
3151 	}
3152     }
3153 
3154   return;
3155 }
3156 
3157 /* Collect all refs in the INSN. This function is free of any
3158    side-effect - it will create and return a lists of df_ref's in the
3159    COLLECTION_REC without putting those refs into existing ref chains
3160    and reg chains. */
3161 
3162 static void
3163 df_insn_refs_collect (struct df_collection_rec *collection_rec,
3164 		      basic_block bb, struct df_insn_info *insn_info)
3165 {
3166   rtx note;
3167   bool is_cond_exec = (GET_CODE (PATTERN (insn_info->insn)) == COND_EXEC);
3168 
3169   /* Clear out the collection record.  */
3170   collection_rec->def_vec.truncate (0);
3171   collection_rec->use_vec.truncate (0);
3172   collection_rec->eq_use_vec.truncate (0);
3173   collection_rec->mw_vec.truncate (0);
3174 
3175   /* Process REG_EQUIV/REG_EQUAL notes.  */
3176   for (note = REG_NOTES (insn_info->insn); note;
3177        note = XEXP (note, 1))
3178     {
3179       switch (REG_NOTE_KIND (note))
3180         {
3181         case REG_EQUIV:
3182         case REG_EQUAL:
3183           df_uses_record (collection_rec,
3184                           &XEXP (note, 0), DF_REF_REG_USE,
3185                           bb, insn_info, DF_REF_IN_NOTE);
3186           break;
3187         case REG_NON_LOCAL_GOTO:
3188           /* The frame ptr is used by a non-local goto.  */
3189           df_ref_record (DF_REF_BASE, collection_rec,
3190                          regno_reg_rtx[FRAME_POINTER_REGNUM],
3191                          NULL, bb, insn_info,
3192                          DF_REF_REG_USE, 0);
3193 	  if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
3194 	    df_ref_record (DF_REF_BASE, collection_rec,
3195 			   regno_reg_rtx[HARD_FRAME_POINTER_REGNUM],
3196 			   NULL, bb, insn_info,
3197 			   DF_REF_REG_USE, 0);
3198           break;
3199         default:
3200           break;
3201         }
3202     }
3203 
3204   int flags = (is_cond_exec) ? DF_REF_CONDITIONAL : 0;
3205   /* For CALL_INSNs, first record DF_REF_BASE register defs, as well as
3206      uses from CALL_INSN_FUNCTION_USAGE. */
3207   if (CALL_P (insn_info->insn))
3208     df_get_call_refs (collection_rec, bb, insn_info, flags);
3209 
3210   if (asm_noperands (PATTERN (insn_info->insn)) >= 0)
3211     for (unsigned i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3212       if (global_regs[i])
3213        {
3214          /* As with calls, asm statements reference all global regs. */
3215          df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3216                         NULL, bb, insn_info, DF_REF_REG_USE, flags);
3217          df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3218                         NULL, bb, insn_info, DF_REF_REG_DEF, flags);
3219        }
3220 
3221   /* Record other defs.  These should be mostly for DF_REF_REGULAR, so
3222      that a qsort on the defs is unnecessary in most cases.  */
3223   df_defs_record (collection_rec,
3224 		  PATTERN (insn_info->insn), bb, insn_info, 0);
3225 
3226   /* Record the register uses.  */
3227   df_uses_record (collection_rec,
3228 		  &PATTERN (insn_info->insn), DF_REF_REG_USE, bb, insn_info, 0);
3229 
3230   /* DF_REF_CONDITIONAL needs corresponding USES. */
3231   if (is_cond_exec)
3232     df_get_conditional_uses (collection_rec);
3233 
3234   df_canonize_collection_rec (collection_rec);
3235 }
3236 
3237 /* Recompute the luids for the insns in BB.  */
3238 
3239 void
3240 df_recompute_luids (basic_block bb)
3241 {
3242   rtx_insn *insn;
3243   int luid = 0;
3244 
3245   df_grow_insn_info ();
3246 
3247   /* Scan the block an insn at a time from beginning to end.  */
3248   FOR_BB_INSNS (bb, insn)
3249     {
3250       struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
3251       /* Inserting labels does not always trigger the incremental
3252 	 rescanning.  */
3253       if (!insn_info)
3254 	{
3255 	  gcc_assert (!INSN_P (insn));
3256 	  insn_info = df_insn_create_insn_record (insn);
3257 	}
3258 
3259       DF_INSN_INFO_LUID (insn_info) = luid;
3260       if (INSN_P (insn))
3261 	luid++;
3262     }
3263 }
3264 
3265 
3266 /* Collect all artificial refs at the block level for BB and add them
3267    to COLLECTION_REC.  */
3268 
3269 static void
3270 df_bb_refs_collect (struct df_collection_rec *collection_rec, basic_block bb)
3271 {
3272   collection_rec->def_vec.truncate (0);
3273   collection_rec->use_vec.truncate (0);
3274   collection_rec->eq_use_vec.truncate (0);
3275   collection_rec->mw_vec.truncate (0);
3276 
3277   if (bb->index == ENTRY_BLOCK)
3278     {
3279       df_entry_block_defs_collect (collection_rec, df->entry_block_defs);
3280       return;
3281     }
3282   else if (bb->index == EXIT_BLOCK)
3283     {
3284       df_exit_block_uses_collect (collection_rec, df->exit_block_uses);
3285       return;
3286     }
3287 
3288   if (bb_has_eh_pred (bb))
3289     {
3290       unsigned int i;
3291       /* Mark the registers that will contain data for the handler.  */
3292       for (i = 0; ; ++i)
3293 	{
3294 	  unsigned regno = EH_RETURN_DATA_REGNO (i);
3295 	  if (regno == INVALID_REGNUM)
3296 	    break;
3297 	  df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[regno], NULL,
3298 			 bb, NULL, DF_REF_REG_DEF, DF_REF_AT_TOP);
3299 	}
3300     }
3301 
3302   /* Add the hard_frame_pointer if this block is the target of a
3303      non-local goto.  */
3304   if (bb->flags & BB_NON_LOCAL_GOTO_TARGET)
3305     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, hard_frame_pointer_rtx, NULL,
3306 		   bb, NULL, DF_REF_REG_DEF, DF_REF_AT_TOP);
3307 
3308   /* Add the artificial uses.  */
3309   if (bb->index >= NUM_FIXED_BLOCKS)
3310     {
3311       bitmap_iterator bi;
3312       unsigned int regno;
3313       bitmap au = bb_has_eh_pred (bb)
3314 	? &df->eh_block_artificial_uses
3315 	: &df->regular_block_artificial_uses;
3316 
3317       EXECUTE_IF_SET_IN_BITMAP (au, 0, regno, bi)
3318 	{
3319 	  df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[regno], NULL,
3320 			 bb, NULL, DF_REF_REG_USE, 0);
3321 	}
3322     }
3323 
3324   df_canonize_collection_rec (collection_rec);
3325 }
3326 
3327 
3328 /* Record all the refs within the basic block BB_INDEX and scan the instructions if SCAN_INSNS.  */
3329 
3330 void
3331 df_bb_refs_record (int bb_index, bool scan_insns)
3332 {
3333   basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
3334   rtx_insn *insn;
3335   int luid = 0;
3336 
3337   if (!df)
3338     return;
3339 
3340   df_collection_rec collection_rec;
3341   df_grow_bb_info (df_scan);
3342   if (scan_insns)
3343     /* Scan the block an insn at a time from beginning to end.  */
3344     FOR_BB_INSNS (bb, insn)
3345       {
3346 	struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
3347 	gcc_assert (!insn_info);
3348 
3349 	insn_info = df_insn_create_insn_record (insn);
3350 	if (INSN_P (insn))
3351 	  {
3352 	    /* Record refs within INSN.  */
3353 	    DF_INSN_INFO_LUID (insn_info) = luid++;
3354 	    df_insn_refs_collect (&collection_rec, bb, DF_INSN_INFO_GET (insn));
3355 	    df_refs_add_to_chains (&collection_rec, bb, insn, copy_all);
3356 	  }
3357 	DF_INSN_INFO_LUID (insn_info) = luid;
3358       }
3359 
3360   /* Other block level artificial refs */
3361   df_bb_refs_collect (&collection_rec, bb);
3362   df_refs_add_to_chains (&collection_rec, bb, NULL, copy_all);
3363 
3364   /* Now that the block has been processed, set the block as dirty so
3365      LR and LIVE will get it processed.  */
3366   df_set_bb_dirty (bb);
3367 }
3368 
3369 
3370 /* Get the artificial use set for a regular (i.e. non-exit/non-entry)
3371    block. */
3372 
3373 static void
3374 df_get_regular_block_artificial_uses (bitmap regular_block_artificial_uses)
3375 {
3376 #ifdef EH_USES
3377   unsigned int i;
3378 #endif
3379 
3380   bitmap_clear (regular_block_artificial_uses);
3381 
3382   if (reload_completed)
3383     {
3384       if (frame_pointer_needed)
3385 	bitmap_set_bit (regular_block_artificial_uses, HARD_FRAME_POINTER_REGNUM);
3386     }
3387   else
3388     /* Before reload, there are a few registers that must be forced
3389        live everywhere -- which might not already be the case for
3390        blocks within infinite loops.  */
3391     {
3392       unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3393 
3394       /* Any reference to any pseudo before reload is a potential
3395 	 reference of the frame pointer.  */
3396       bitmap_set_bit (regular_block_artificial_uses, FRAME_POINTER_REGNUM);
3397 
3398       if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
3399 	bitmap_set_bit (regular_block_artificial_uses,
3400 			HARD_FRAME_POINTER_REGNUM);
3401 
3402       /* Pseudos with argument area equivalences may require
3403 	 reloading via the argument pointer.  */
3404       if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3405 	  && fixed_regs[ARG_POINTER_REGNUM])
3406 	bitmap_set_bit (regular_block_artificial_uses, ARG_POINTER_REGNUM);
3407 
3408       /* Any constant, or pseudo with constant equivalences, may
3409 	 require reloading from memory using the pic register.  */
3410       if (picreg != INVALID_REGNUM
3411 	  && fixed_regs[picreg])
3412 	bitmap_set_bit (regular_block_artificial_uses, picreg);
3413     }
3414   /* The all-important stack pointer must always be live.  */
3415   bitmap_set_bit (regular_block_artificial_uses, STACK_POINTER_REGNUM);
3416 
3417 #ifdef EH_USES
3418   /* EH_USES registers are used:
3419      1) at all insns that might throw (calls or with -fnon-call-exceptions
3420 	trapping insns)
3421      2) in all EH edges
3422      3) to support backtraces and/or debugging, anywhere between their
3423 	initialization and where they the saved registers are restored
3424 	from them, including the cases where we don't reach the epilogue
3425 	(noreturn call or infinite loop).  */
3426   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3427     if (EH_USES (i))
3428       bitmap_set_bit (regular_block_artificial_uses, i);
3429 #endif
3430 }
3431 
3432 
3433 /* Get the artificial use set for an eh block. */
3434 
3435 static void
3436 df_get_eh_block_artificial_uses (bitmap eh_block_artificial_uses)
3437 {
3438   bitmap_clear (eh_block_artificial_uses);
3439 
3440   /* The following code (down through the arg_pointer setting APPEARS
3441      to be necessary because there is nothing that actually
3442      describes what the exception handling code may actually need
3443      to keep alive.  */
3444   if (reload_completed)
3445     {
3446       if (frame_pointer_needed)
3447 	{
3448 	  bitmap_set_bit (eh_block_artificial_uses, FRAME_POINTER_REGNUM);
3449 	  if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
3450 	    bitmap_set_bit (eh_block_artificial_uses,
3451 			    HARD_FRAME_POINTER_REGNUM);
3452 	}
3453       if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3454 	  && fixed_regs[ARG_POINTER_REGNUM])
3455 	bitmap_set_bit (eh_block_artificial_uses, ARG_POINTER_REGNUM);
3456     }
3457 }
3458 
3459 
3460 
3461 /*----------------------------------------------------------------------------
3462    Specialized hard register scanning functions.
3463 ----------------------------------------------------------------------------*/
3464 
3465 
3466 /* Mark a register in SET.  Hard registers in large modes get all
3467    of their component registers set as well.  */
3468 
3469 static void
3470 df_mark_reg (rtx reg, void *vset)
3471 {
3472   bitmap_set_range ((bitmap) vset, REGNO (reg), REG_NREGS (reg));
3473 }
3474 
3475 
3476 /* Set the bit for regs that are considered being defined at the entry. */
3477 
3478 static void
3479 df_get_entry_block_def_set (bitmap entry_block_defs)
3480 {
3481   rtx r;
3482   int i;
3483 
3484   bitmap_clear (entry_block_defs);
3485 
3486   /* For separate shrink-wrapping we use LIVE to analyze which basic blocks
3487      need a prologue for some component to be executed before that block,
3488      and we do not care about any other registers.  Hence, we do not want
3489      any register for any component defined in the entry block, and we can
3490      just leave all registers undefined.  */
3491   if (df_scan->local_flags & DF_SCAN_EMPTY_ENTRY_EXIT)
3492     return;
3493 
3494   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3495     {
3496       if (global_regs[i])
3497 	bitmap_set_bit (entry_block_defs, i);
3498       if (FUNCTION_ARG_REGNO_P (i))
3499 	bitmap_set_bit (entry_block_defs, INCOMING_REGNO (i));
3500     }
3501 
3502   /* The always important stack pointer.  */
3503   bitmap_set_bit (entry_block_defs, STACK_POINTER_REGNUM);
3504 
3505   /* Once the prologue has been generated, all of these registers
3506      should just show up in the first regular block.  */
3507   if (targetm.have_prologue () && epilogue_completed)
3508     {
3509       /* Defs for the callee saved registers are inserted so that the
3510 	 pushes have some defining location.  */
3511       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3512 	if ((call_used_regs[i] == 0) && (df_regs_ever_live_p (i)))
3513 	  bitmap_set_bit (entry_block_defs, i);
3514     }
3515 
3516   r = targetm.calls.struct_value_rtx (current_function_decl, true);
3517   if (r && REG_P (r))
3518     bitmap_set_bit (entry_block_defs, REGNO (r));
3519 
3520   /* If the function has an incoming STATIC_CHAIN, it has to show up
3521      in the entry def set.  */
3522   r = rtx_for_static_chain (current_function_decl, true);
3523   if (r && REG_P (r))
3524     bitmap_set_bit (entry_block_defs, REGNO (r));
3525 
3526   if ((!reload_completed) || frame_pointer_needed)
3527     {
3528       /* Any reference to any pseudo before reload is a potential
3529 	 reference of the frame pointer.  */
3530       bitmap_set_bit (entry_block_defs, FRAME_POINTER_REGNUM);
3531 
3532       /* If they are different, also mark the hard frame pointer as live.  */
3533       if (!HARD_FRAME_POINTER_IS_FRAME_POINTER
3534 	  && !LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM))
3535 	bitmap_set_bit (entry_block_defs, HARD_FRAME_POINTER_REGNUM);
3536     }
3537 
3538   /* These registers are live everywhere.  */
3539   if (!reload_completed)
3540     {
3541       /* Pseudos with argument area equivalences may require
3542 	 reloading via the argument pointer.  */
3543       if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3544 	  && fixed_regs[ARG_POINTER_REGNUM])
3545 	bitmap_set_bit (entry_block_defs, ARG_POINTER_REGNUM);
3546 
3547       /* Any constant, or pseudo with constant equivalences, may
3548 	 require reloading from memory using the pic register.  */
3549       unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3550       if (picreg != INVALID_REGNUM
3551 	  && fixed_regs[picreg])
3552 	bitmap_set_bit (entry_block_defs, picreg);
3553     }
3554 
3555 #ifdef INCOMING_RETURN_ADDR_RTX
3556   if (REG_P (INCOMING_RETURN_ADDR_RTX))
3557     bitmap_set_bit (entry_block_defs, REGNO (INCOMING_RETURN_ADDR_RTX));
3558 #endif
3559 
3560   targetm.extra_live_on_entry (entry_block_defs);
3561 }
3562 
3563 
3564 /* Return the (conservative) set of hard registers that are defined on
3565    entry to the function.
3566    It uses df->entry_block_defs to determine which register
3567    reference to include.  */
3568 
3569 static void
3570 df_entry_block_defs_collect (struct df_collection_rec *collection_rec,
3571 			     bitmap entry_block_defs)
3572 {
3573   unsigned int i;
3574   bitmap_iterator bi;
3575 
3576   EXECUTE_IF_SET_IN_BITMAP (entry_block_defs, 0, i, bi)
3577     {
3578       df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[i], NULL,
3579 		     ENTRY_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_DEF, 0);
3580     }
3581 
3582   df_canonize_collection_rec (collection_rec);
3583 }
3584 
3585 
3586 /* Record the (conservative) set of hard registers that are defined on
3587    entry to the function.  */
3588 
3589 static void
3590 df_record_entry_block_defs (bitmap entry_block_defs)
3591 {
3592   struct df_collection_rec collection_rec;
3593   df_entry_block_defs_collect (&collection_rec, entry_block_defs);
3594 
3595   /* Process bb_refs chain */
3596   df_refs_add_to_chains (&collection_rec,
3597 			 BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK),
3598 			 NULL,
3599 			 copy_defs);
3600 }
3601 
3602 
3603 /* Update the defs in the entry block.  */
3604 
3605 void
3606 df_update_entry_block_defs (void)
3607 {
3608   bool changed = false;
3609 
3610   auto_bitmap refs (&df_bitmap_obstack);
3611   df_get_entry_block_def_set (refs);
3612   if (df->entry_block_defs)
3613     {
3614       if (!bitmap_equal_p (df->entry_block_defs, refs))
3615 	{
3616 	  struct df_scan_bb_info *bb_info = df_scan_get_bb_info (ENTRY_BLOCK);
3617 	  df_ref_chain_delete_du_chain (bb_info->artificial_defs);
3618 	  df_ref_chain_delete (bb_info->artificial_defs);
3619 	  bb_info->artificial_defs = NULL;
3620 	  changed = true;
3621 	}
3622     }
3623   else
3624     {
3625       struct df_scan_problem_data *problem_data
3626 	= (struct df_scan_problem_data *) df_scan->problem_data;
3627 	gcc_unreachable ();
3628       df->entry_block_defs = BITMAP_ALLOC (&problem_data->reg_bitmaps);
3629       changed = true;
3630     }
3631 
3632   if (changed)
3633     {
3634       df_record_entry_block_defs (refs);
3635       bitmap_copy (df->entry_block_defs, refs);
3636       df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK));
3637     }
3638 }
3639 
3640 
3641 /* Set the bit for regs that are considered being used at the exit. */
3642 
3643 static void
3644 df_get_exit_block_use_set (bitmap exit_block_uses)
3645 {
3646   unsigned int i;
3647   unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3648 
3649   bitmap_clear (exit_block_uses);
3650 
3651   /* For separate shrink-wrapping we use LIVE to analyze which basic blocks
3652      need an epilogue for some component to be executed after that block,
3653      and we do not care about any other registers.  Hence, we do not want
3654      any register for any component seen as used in the exit block, and we
3655      can just say no registers at all are used.  */
3656   if (df_scan->local_flags & DF_SCAN_EMPTY_ENTRY_EXIT)
3657     return;
3658 
3659   /* Stack pointer is always live at the exit.  */
3660   bitmap_set_bit (exit_block_uses, STACK_POINTER_REGNUM);
3661 
3662   /* Mark the frame pointer if needed at the end of the function.
3663      If we end up eliminating it, it will be removed from the live
3664      list of each basic block by reload.  */
3665 
3666   if ((!reload_completed) || frame_pointer_needed)
3667     {
3668       bitmap_set_bit (exit_block_uses, FRAME_POINTER_REGNUM);
3669 
3670       /* If they are different, also mark the hard frame pointer as live.  */
3671       if (!HARD_FRAME_POINTER_IS_FRAME_POINTER
3672 	  && !LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM))
3673 	bitmap_set_bit (exit_block_uses, HARD_FRAME_POINTER_REGNUM);
3674     }
3675 
3676   /* Many architectures have a GP register even without flag_pic.
3677      Assume the pic register is not in use, or will be handled by
3678      other means, if it is not fixed.  */
3679   if (!PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
3680       && picreg != INVALID_REGNUM
3681       && fixed_regs[picreg])
3682     bitmap_set_bit (exit_block_uses, picreg);
3683 
3684   /* Mark all global registers, and all registers used by the
3685      epilogue as being live at the end of the function since they
3686      may be referenced by our caller.  */
3687   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3688     if (global_regs[i] || EPILOGUE_USES (i))
3689       bitmap_set_bit (exit_block_uses, i);
3690 
3691   if (targetm.have_epilogue () && epilogue_completed)
3692     {
3693       /* Mark all call-saved registers that we actually used.  */
3694       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3695 	if (df_regs_ever_live_p (i) && !LOCAL_REGNO (i)
3696 	    && !TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
3697 	  bitmap_set_bit (exit_block_uses, i);
3698     }
3699 
3700   /* Mark the registers that will contain data for the handler.  */
3701   if (reload_completed && crtl->calls_eh_return)
3702     for (i = 0; ; ++i)
3703       {
3704 	unsigned regno = EH_RETURN_DATA_REGNO (i);
3705 	if (regno == INVALID_REGNUM)
3706 	  break;
3707 	bitmap_set_bit (exit_block_uses, regno);
3708       }
3709 
3710 #ifdef EH_RETURN_STACKADJ_RTX
3711   if ((!targetm.have_epilogue () || ! epilogue_completed)
3712       && crtl->calls_eh_return)
3713     {
3714       rtx tmp = EH_RETURN_STACKADJ_RTX;
3715       if (tmp && REG_P (tmp))
3716 	df_mark_reg (tmp, exit_block_uses);
3717     }
3718 #endif
3719 
3720   if ((!targetm.have_epilogue () || ! epilogue_completed)
3721       && crtl->calls_eh_return)
3722     {
3723       rtx tmp = EH_RETURN_HANDLER_RTX;
3724       if (tmp && REG_P (tmp))
3725 	df_mark_reg (tmp, exit_block_uses);
3726     }
3727 
3728   /* Mark function return value.  */
3729   diddle_return_value (df_mark_reg, (void*) exit_block_uses);
3730 }
3731 
3732 
3733 /* Return the refs of hard registers that are used in the exit block.
3734    It uses df->exit_block_uses to determine register to include.  */
3735 
3736 static void
3737 df_exit_block_uses_collect (struct df_collection_rec *collection_rec, bitmap exit_block_uses)
3738 {
3739   unsigned int i;
3740   bitmap_iterator bi;
3741 
3742   EXECUTE_IF_SET_IN_BITMAP (exit_block_uses, 0, i, bi)
3743     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[i], NULL,
3744 		   EXIT_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_USE, 0);
3745 
3746   /* It is deliberate that this is not put in the exit block uses but
3747      I do not know why.  */
3748   if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3749       && reload_completed
3750       && !bitmap_bit_p (exit_block_uses, ARG_POINTER_REGNUM)
3751       && bb_has_eh_pred (EXIT_BLOCK_PTR_FOR_FN (cfun))
3752       && fixed_regs[ARG_POINTER_REGNUM])
3753     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[ARG_POINTER_REGNUM], NULL,
3754 		   EXIT_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_USE, 0);
3755 
3756   df_canonize_collection_rec (collection_rec);
3757 }
3758 
3759 
3760 /* Record the set of hard registers that are used in the exit block.
3761    It uses df->exit_block_uses to determine which bit to include.  */
3762 
3763 static void
3764 df_record_exit_block_uses (bitmap exit_block_uses)
3765 {
3766   struct df_collection_rec collection_rec;
3767   df_exit_block_uses_collect (&collection_rec, exit_block_uses);
3768 
3769   /* Process bb_refs chain */
3770   df_refs_add_to_chains (&collection_rec,
3771 			 BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK),
3772 			 NULL,
3773 			 copy_uses);
3774 }
3775 
3776 
3777 /* Update the uses in the exit block.  */
3778 
3779 void
3780 df_update_exit_block_uses (void)
3781 {
3782   bool changed = false;
3783 
3784   auto_bitmap refs (&df_bitmap_obstack);
3785   df_get_exit_block_use_set (refs);
3786   if (df->exit_block_uses)
3787     {
3788       if (!bitmap_equal_p (df->exit_block_uses, refs))
3789 	{
3790 	  struct df_scan_bb_info *bb_info = df_scan_get_bb_info (EXIT_BLOCK);
3791 	  df_ref_chain_delete_du_chain (bb_info->artificial_uses);
3792 	  df_ref_chain_delete (bb_info->artificial_uses);
3793 	  bb_info->artificial_uses = NULL;
3794 	  changed = true;
3795 	}
3796     }
3797   else
3798     {
3799       struct df_scan_problem_data *problem_data
3800 	= (struct df_scan_problem_data *) df_scan->problem_data;
3801 	gcc_unreachable ();
3802       df->exit_block_uses = BITMAP_ALLOC (&problem_data->reg_bitmaps);
3803       changed = true;
3804     }
3805 
3806   if (changed)
3807     {
3808       df_record_exit_block_uses (refs);
3809       bitmap_copy (df->exit_block_uses, refs);
3810       df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK));
3811     }
3812 }
3813 
3814 static bool initialized = false;
3815 
3816 
3817 /* Initialize some platform specific structures.  */
3818 
3819 void
3820 df_hard_reg_init (void)
3821 {
3822   int i;
3823   static const struct {const int from, to; } eliminables[] = ELIMINABLE_REGS;
3824 
3825   if (initialized)
3826     return;
3827 
3828   /* Record which registers will be eliminated.  We use this in
3829      mark_used_regs.  */
3830   CLEAR_HARD_REG_SET (elim_reg_set);
3831 
3832   for (i = 0; i < (int) ARRAY_SIZE (eliminables); i++)
3833     SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from);
3834 
3835   initialized = true;
3836 }
3837 
3838 
3839 /* Recompute the parts of scanning that are based on regs_ever_live
3840    because something changed in that array.  */
3841 
3842 void
3843 df_update_entry_exit_and_calls (void)
3844 {
3845   basic_block bb;
3846 
3847   df_update_entry_block_defs ();
3848   df_update_exit_block_uses ();
3849 
3850   /* The call insns need to be rescanned because there may be changes
3851      in the set of registers clobbered across the call.  */
3852   FOR_EACH_BB_FN (bb, cfun)
3853     {
3854       rtx_insn *insn;
3855       FOR_BB_INSNS (bb, insn)
3856 	{
3857 	  if (INSN_P (insn) && CALL_P (insn))
3858 	    df_insn_rescan (insn);
3859 	}
3860     }
3861 }
3862 
3863 
3864 /* Return true if hard REG is actually used in the some instruction.
3865    There are a fair number of conditions that affect the setting of
3866    this array.  See the comment in df.h for df->hard_regs_live_count
3867    for the conditions that this array is set. */
3868 
3869 bool
3870 df_hard_reg_used_p (unsigned int reg)
3871 {
3872   return df->hard_regs_live_count[reg] != 0;
3873 }
3874 
3875 
3876 /* A count of the number of times REG is actually used in the some
3877    instruction.  There are a fair number of conditions that affect the
3878    setting of this array.  See the comment in df.h for
3879    df->hard_regs_live_count for the conditions that this array is
3880    set. */
3881 
3882 
3883 unsigned int
3884 df_hard_reg_used_count (unsigned int reg)
3885 {
3886   return df->hard_regs_live_count[reg];
3887 }
3888 
3889 
3890 /* Get the value of regs_ever_live[REGNO].  */
3891 
3892 bool
3893 df_regs_ever_live_p (unsigned int regno)
3894 {
3895   return regs_ever_live[regno];
3896 }
3897 
3898 
3899 /* Set regs_ever_live[REGNO] to VALUE.  If this cause regs_ever_live
3900    to change, schedule that change for the next update.  */
3901 
3902 void
3903 df_set_regs_ever_live (unsigned int regno, bool value)
3904 {
3905   if (regs_ever_live[regno] == value)
3906     return;
3907 
3908   regs_ever_live[regno] = value;
3909   if (df)
3910     df->redo_entry_and_exit = true;
3911 }
3912 
3913 
3914 /* Compute "regs_ever_live" information from the underlying df
3915    information.  Set the vector to all false if RESET.  */
3916 
3917 void
3918 df_compute_regs_ever_live (bool reset)
3919 {
3920   unsigned int i;
3921   bool changed = df->redo_entry_and_exit;
3922 
3923   if (reset)
3924     memset (regs_ever_live, 0, sizeof (regs_ever_live));
3925 
3926   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3927     if ((!regs_ever_live[i]) && df_hard_reg_used_p (i))
3928       {
3929 	regs_ever_live[i] = true;
3930 	changed = true;
3931       }
3932   if (changed)
3933     df_update_entry_exit_and_calls ();
3934   df->redo_entry_and_exit = false;
3935 }
3936 
3937 
3938 /*----------------------------------------------------------------------------
3939   Dataflow ref information verification functions.
3940 
3941   df_reg_chain_mark (refs, regno, is_def, is_eq_use)
3942   df_reg_chain_verify_unmarked (refs)
3943   df_refs_verify (vec<stack, va_df_ref>, ref*, bool)
3944   df_mws_verify (mw*, mw*, bool)
3945   df_insn_refs_verify (collection_rec, bb, insn, bool)
3946   df_bb_refs_verify (bb, refs, bool)
3947   df_bb_verify (bb)
3948   df_exit_block_bitmap_verify (bool)
3949   df_entry_block_bitmap_verify (bool)
3950   df_scan_verify ()
3951 ----------------------------------------------------------------------------*/
3952 
3953 
3954 /* Mark all refs in the reg chain.  Verify that all of the registers
3955 are in the correct chain.  */
3956 
3957 static unsigned int
3958 df_reg_chain_mark (df_ref refs, unsigned int regno,
3959 		   bool is_def, bool is_eq_use)
3960 {
3961   unsigned int count = 0;
3962   df_ref ref;
3963   for (ref = refs; ref; ref = DF_REF_NEXT_REG (ref))
3964     {
3965       gcc_assert (!DF_REF_IS_REG_MARKED (ref));
3966 
3967       /* If there are no def-use or use-def chains, make sure that all
3968 	 of the chains are clear.  */
3969       if (!df_chain)
3970 	gcc_assert (!DF_REF_CHAIN (ref));
3971 
3972       /* Check to make sure the ref is in the correct chain.  */
3973       gcc_assert (DF_REF_REGNO (ref) == regno);
3974       if (is_def)
3975 	gcc_assert (DF_REF_REG_DEF_P (ref));
3976       else
3977 	gcc_assert (!DF_REF_REG_DEF_P (ref));
3978 
3979       if (is_eq_use)
3980 	gcc_assert ((DF_REF_FLAGS (ref) & DF_REF_IN_NOTE));
3981       else
3982 	gcc_assert ((DF_REF_FLAGS (ref) & DF_REF_IN_NOTE) == 0);
3983 
3984       if (DF_REF_NEXT_REG (ref))
3985 	gcc_assert (DF_REF_PREV_REG (DF_REF_NEXT_REG (ref)) == ref);
3986       count++;
3987       DF_REF_REG_MARK (ref);
3988     }
3989   return count;
3990 }
3991 
3992 
3993 /* Verify that all of the registers in the chain are unmarked.  */
3994 
3995 static void
3996 df_reg_chain_verify_unmarked (df_ref refs)
3997 {
3998   df_ref ref;
3999   for (ref = refs; ref; ref = DF_REF_NEXT_REG (ref))
4000     gcc_assert (!DF_REF_IS_REG_MARKED (ref));
4001 }
4002 
4003 
4004 /* Verify that NEW_REC and OLD_REC have exactly the same members. */
4005 
4006 static bool
4007 df_refs_verify (const vec<df_ref, va_heap> *new_rec, df_ref old_rec,
4008 		bool abort_if_fail)
4009 {
4010   unsigned int ix;
4011   df_ref new_ref;
4012 
4013   FOR_EACH_VEC_ELT (*new_rec, ix, new_ref)
4014     {
4015       if (old_rec == NULL || !df_ref_equal_p (new_ref, old_rec))
4016 	{
4017 	  if (abort_if_fail)
4018 	    gcc_assert (0);
4019 	  else
4020 	    return false;
4021 	}
4022 
4023       /* Abort if fail is called from the function level verifier.  If
4024 	 that is the context, mark this reg as being seem.  */
4025       if (abort_if_fail)
4026 	{
4027 	  gcc_assert (DF_REF_IS_REG_MARKED (old_rec));
4028 	  DF_REF_REG_UNMARK (old_rec);
4029 	}
4030 
4031       old_rec = DF_REF_NEXT_LOC (old_rec);
4032     }
4033 
4034   if (abort_if_fail)
4035     gcc_assert (old_rec == NULL);
4036   else
4037     return old_rec == NULL;
4038   return false;
4039 }
4040 
4041 
4042 /* Verify that NEW_REC and OLD_REC have exactly the same members. */
4043 
4044 static bool
4045 df_mws_verify (const vec<df_mw_hardreg *, va_heap> *new_rec,
4046 	       struct df_mw_hardreg *old_rec,
4047 	       bool abort_if_fail)
4048 {
4049   unsigned int ix;
4050   struct df_mw_hardreg *new_reg;
4051 
4052   FOR_EACH_VEC_ELT (*new_rec, ix, new_reg)
4053     {
4054       if (old_rec == NULL || !df_mw_equal_p (new_reg, old_rec))
4055 	{
4056 	  if (abort_if_fail)
4057 	    gcc_assert (0);
4058 	  else
4059 	    return false;
4060 	}
4061       old_rec = DF_MWS_NEXT (old_rec);
4062     }
4063 
4064   if (abort_if_fail)
4065     gcc_assert (old_rec == NULL);
4066   else
4067     return old_rec == NULL;
4068   return false;
4069 }
4070 
4071 
4072 /* Return true if the existing insn refs information is complete and
4073    correct. Otherwise (i.e. if there's any missing or extra refs),
4074    return the correct df_ref chain in REFS_RETURN.
4075 
4076    If ABORT_IF_FAIL, leave the refs that are verified (already in the
4077    ref chain) as DF_REF_MARKED(). If it's false, then it's a per-insn
4078    verification mode instead of the whole function, so unmark
4079    everything.
4080 
4081    If ABORT_IF_FAIL is set, this function never returns false.  */
4082 
4083 static bool
4084 df_insn_refs_verify (struct df_collection_rec *collection_rec,
4085 		     basic_block bb,
4086                      rtx_insn *insn,
4087 		     bool abort_if_fail)
4088 {
4089   bool ret1, ret2, ret3;
4090   unsigned int uid = INSN_UID (insn);
4091   struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
4092 
4093   df_insn_refs_collect (collection_rec, bb, insn_info);
4094 
4095   /* Unfortunately we cannot opt out early if one of these is not
4096      right and abort_if_fail is set because the marks will not get cleared.  */
4097   ret1 = df_refs_verify (&collection_rec->def_vec, DF_INSN_UID_DEFS (uid),
4098 			 abort_if_fail);
4099   if (!ret1 && !abort_if_fail)
4100     return false;
4101   ret2 = df_refs_verify (&collection_rec->use_vec, DF_INSN_UID_USES (uid),
4102 			 abort_if_fail);
4103   if (!ret2 && !abort_if_fail)
4104     return false;
4105   ret3 = df_refs_verify (&collection_rec->eq_use_vec, DF_INSN_UID_EQ_USES (uid),
4106 			 abort_if_fail);
4107   if (!ret3 && !abort_if_fail)
4108     return false;
4109   if (! df_mws_verify (&collection_rec->mw_vec, DF_INSN_UID_MWS (uid),
4110 		       abort_if_fail))
4111     return false;
4112   return (ret1 && ret2 && ret3);
4113 }
4114 
4115 
4116 /* Return true if all refs in the basic block are correct and complete.
4117    Due to df_ref_chain_verify, it will cause all refs
4118    that are verified to have DF_REF_MARK bit set.  */
4119 
4120 static bool
4121 df_bb_verify (basic_block bb)
4122 {
4123   rtx_insn *insn;
4124   struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb->index);
4125   struct df_collection_rec collection_rec;
4126 
4127   gcc_assert (bb_info);
4128 
4129   /* Scan the block, one insn at a time, from beginning to end.  */
4130   FOR_BB_INSNS_REVERSE (bb, insn)
4131     {
4132       if (!INSN_P (insn))
4133         continue;
4134       df_insn_refs_verify (&collection_rec, bb, insn, true);
4135       df_free_collection_rec (&collection_rec);
4136     }
4137 
4138   /* Do the artificial defs and uses.  */
4139   df_bb_refs_collect (&collection_rec, bb);
4140   df_refs_verify (&collection_rec.def_vec, df_get_artificial_defs (bb->index), true);
4141   df_refs_verify (&collection_rec.use_vec, df_get_artificial_uses (bb->index), true);
4142   df_free_collection_rec (&collection_rec);
4143 
4144   return true;
4145 }
4146 
4147 
4148 /* Returns true if the entry block has correct and complete df_ref set.
4149    If not it either aborts if ABORT_IF_FAIL is true or returns false.  */
4150 
4151 static bool
4152 df_entry_block_bitmap_verify (bool abort_if_fail)
4153 {
4154   bool is_eq;
4155 
4156   auto_bitmap entry_block_defs (&df_bitmap_obstack);
4157   df_get_entry_block_def_set (entry_block_defs);
4158 
4159   is_eq = bitmap_equal_p (entry_block_defs, df->entry_block_defs);
4160 
4161   if (!is_eq && abort_if_fail)
4162     {
4163       fprintf (stderr, "entry_block_defs = ");
4164       df_print_regset (stderr, entry_block_defs);
4165       fprintf (stderr, "df->entry_block_defs = ");
4166       df_print_regset (stderr, df->entry_block_defs);
4167       gcc_assert (0);
4168     }
4169 
4170   return is_eq;
4171 }
4172 
4173 
4174 /* Returns true if the exit block has correct and complete df_ref set.
4175    If not it either aborts if ABORT_IF_FAIL is true or returns false. */
4176 
4177 static bool
4178 df_exit_block_bitmap_verify (bool abort_if_fail)
4179 {
4180   bool is_eq;
4181 
4182   auto_bitmap exit_block_uses (&df_bitmap_obstack);
4183   df_get_exit_block_use_set (exit_block_uses);
4184 
4185   is_eq = bitmap_equal_p (exit_block_uses, df->exit_block_uses);
4186 
4187   if (!is_eq && abort_if_fail)
4188     {
4189       fprintf (stderr, "exit_block_uses = ");
4190       df_print_regset (stderr, exit_block_uses);
4191       fprintf (stderr, "df->exit_block_uses = ");
4192       df_print_regset (stderr, df->exit_block_uses);
4193       gcc_assert (0);
4194     }
4195 
4196   return is_eq;
4197 }
4198 
4199 
4200 /* Return true if df_ref information for all insns in all blocks are
4201    correct and complete.  */
4202 
4203 void
4204 df_scan_verify (void)
4205 {
4206   unsigned int i;
4207   basic_block bb;
4208 
4209   if (!df)
4210     return;
4211 
4212   /* Verification is a 4 step process. */
4213 
4214   /* (1) All of the refs are marked by going through the reg chains.  */
4215   for (i = 0; i < DF_REG_SIZE (df); i++)
4216     {
4217       gcc_assert (df_reg_chain_mark (DF_REG_DEF_CHAIN (i), i, true, false)
4218 		  == DF_REG_DEF_COUNT (i));
4219       gcc_assert (df_reg_chain_mark (DF_REG_USE_CHAIN (i), i, false, false)
4220 		  == DF_REG_USE_COUNT (i));
4221       gcc_assert (df_reg_chain_mark (DF_REG_EQ_USE_CHAIN (i), i, false, true)
4222 		  == DF_REG_EQ_USE_COUNT (i));
4223     }
4224 
4225   /* (2) There are various bitmaps whose value may change over the
4226      course of the compilation.  This step recomputes them to make
4227      sure that they have not slipped out of date.  */
4228   auto_bitmap regular_block_artificial_uses (&df_bitmap_obstack);
4229   auto_bitmap eh_block_artificial_uses (&df_bitmap_obstack);
4230 
4231   df_get_regular_block_artificial_uses (regular_block_artificial_uses);
4232   df_get_eh_block_artificial_uses (eh_block_artificial_uses);
4233 
4234   bitmap_ior_into (eh_block_artificial_uses,
4235 		   regular_block_artificial_uses);
4236 
4237   /* Check artificial_uses bitmaps didn't change. */
4238   gcc_assert (bitmap_equal_p (regular_block_artificial_uses,
4239 			      &df->regular_block_artificial_uses));
4240   gcc_assert (bitmap_equal_p (eh_block_artificial_uses,
4241 			      &df->eh_block_artificial_uses));
4242 
4243   /* Verify entry block and exit block. These only verify the bitmaps,
4244      the refs are verified in df_bb_verify.  */
4245   df_entry_block_bitmap_verify (true);
4246   df_exit_block_bitmap_verify (true);
4247 
4248   /* (3) All of the insns in all of the blocks are traversed and the
4249      marks are cleared both in the artificial refs attached to the
4250      blocks and the real refs inside the insns.  It is a failure to
4251      clear a mark that has not been set as this means that the ref in
4252      the block or insn was not in the reg chain.  */
4253 
4254   FOR_ALL_BB_FN (bb, cfun)
4255     df_bb_verify (bb);
4256 
4257   /* (4) See if all reg chains are traversed a second time.  This time
4258      a check is made that the marks are clear. A set mark would be a
4259      from a reg that is not in any insn or basic block.  */
4260 
4261   for (i = 0; i < DF_REG_SIZE (df); i++)
4262     {
4263       df_reg_chain_verify_unmarked (DF_REG_DEF_CHAIN (i));
4264       df_reg_chain_verify_unmarked (DF_REG_USE_CHAIN (i));
4265       df_reg_chain_verify_unmarked (DF_REG_EQ_USE_CHAIN (i));
4266     }
4267 }
4268