1 /* Scanning of rtl for dataflow analysis.
2    Copyright (C) 1999-2019 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
df_scan_free_internal(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
df_scan_free_bb_info(basic_block bb,void * vbb_info)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
df_scan_alloc(bitmap all_blocks ATTRIBUTE_UNUSED)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
df_scan_free(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
df_scan_start_dump(FILE * file ATTRIBUTE_UNUSED)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
df_scan_start_block(basic_block bb,FILE * file)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
df_scan_add_problem(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
df_grow_reg_info(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
df_grow_ref_info(struct df_ref_info * ref_info,unsigned int new_size)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
df_check_and_grow_ref_info(struct df_ref_info * ref_info,unsigned bitmap_addend)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
df_grow_insn_info(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
df_scan_blocks(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
df_uses_create(rtx * loc,rtx_insn * insn,int ref_flags)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
df_install_ref_incremental(df_ref ref)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
df_free_ref(df_ref ref)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
df_reg_chain_unlink(df_ref ref)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
df_insn_info_init_fields(df_insn_info * insn_info,rtx_insn * insn)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 *
df_insn_create_insn_record(rtx_insn * insn)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
df_ref_chain_delete_du_chain(df_ref ref)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
df_ref_chain_delete(df_ref ref)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
df_mw_hardreg_chain_delete(struct df_mw_hardreg * hardregs)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
df_insn_info_free_fields(df_insn_info * insn_info)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
df_insn_info_delete(unsigned int uid)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
df_insn_delete(rtx_insn * insn)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
df_free_collection_rec(struct df_collection_rec * collection_rec)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
df_insn_rescan(rtx_insn * insn)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
df_insn_rescan_debug_internal(rtx_insn * insn)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
df_insn_rescan_all(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
df_process_deferred_rescans(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
df_count_refs(bool include_defs,bool include_uses,bool include_eq_uses)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
df_reorganize_refs_by_reg_by_reg(struct df_ref_info * ref_info,bool include_defs,bool include_uses,bool include_eq_uses)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
df_reorganize_refs_by_reg_by_insn(struct df_ref_info * ref_info,bool include_defs,bool include_uses,bool include_eq_uses)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
df_reorganize_refs_by_reg(struct df_ref_info * ref_info,bool include_defs,bool include_uses,bool include_eq_uses)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
df_add_refs_to_table(unsigned int offset,struct df_ref_info * ref_info,df_ref ref)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
df_reorganize_refs_by_insn_bb(basic_block bb,unsigned int offset,struct df_ref_info * ref_info,bool include_defs,bool include_uses,bool include_eq_uses)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
df_reorganize_refs_by_insn(struct df_ref_info * ref_info,bool include_defs,bool include_uses,bool include_eq_uses)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
df_maybe_reorganize_use_refs(enum df_ref_order order)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
df_maybe_reorganize_def_refs(enum df_ref_order order)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
df_insn_change_bb(rtx_insn * insn,basic_block new_bb)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
df_ref_change_reg_with_loc_1(struct df_reg_info * old_df,struct df_reg_info * new_df,unsigned int new_regno,rtx loc)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
df_ref_change_reg_with_loc(rtx loc,unsigned int new_regno)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
df_mw_hardreg_chain_delete_eq_uses(struct df_insn_info * insn_info)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
df_notes_rescan(rtx_insn * insn)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
df_ref_equal_p(df_ref ref1,df_ref ref2)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
df_ref_compare(df_ref ref1,df_ref ref2)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
df_ref_ptr_compare(const void * r1,const void * r2)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
df_sort_and_compress_refs(vec<df_ref,va_heap> * ref_vec)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
df_mw_equal_p(struct df_mw_hardreg * mw1,struct df_mw_hardreg * mw2)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
df_mw_compare(const df_mw_hardreg * mw1,const df_mw_hardreg * mw2)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   return mw1->mw_order - mw2->mw_order;
2212 }
2213 
2214 /* Like df_mw_compare, but compare two df_mw_hardreg** pointers R1 and R2.  */
2215 
2216 static int
df_mw_ptr_compare(const void * m1,const void * m2)2217 df_mw_ptr_compare (const void *m1, const void *m2)
2218 {
2219   return df_mw_compare (*(const df_mw_hardreg *const *) m1,
2220 			*(const df_mw_hardreg *const *) m2);
2221 }
2222 
2223 /* Sort and compress a set of refs.  */
2224 
2225 static void
df_sort_and_compress_mws(vec<df_mw_hardreg *,va_heap> * mw_vec)2226 df_sort_and_compress_mws (vec<df_mw_hardreg *, va_heap> *mw_vec)
2227 {
2228   unsigned int count;
2229   struct df_scan_problem_data *problem_data
2230     = (struct df_scan_problem_data *) df_scan->problem_data;
2231   unsigned int i;
2232   unsigned int dist = 0;
2233 
2234   count = mw_vec->length ();
2235   if (count < 2)
2236     return;
2237   else if (count == 2)
2238     {
2239       struct df_mw_hardreg *m0 = (*mw_vec)[0];
2240       struct df_mw_hardreg *m1 = (*mw_vec)[1];
2241       if (df_mw_compare (m0, m1) > 0)
2242         {
2243           struct df_mw_hardreg *tmp = (*mw_vec)[0];
2244 	  (*mw_vec)[0] = (*mw_vec)[1];
2245 	  (*mw_vec)[1] = tmp;
2246         }
2247     }
2248   else
2249     mw_vec->qsort (df_mw_ptr_compare);
2250 
2251   for (i=0; i<count-dist; i++)
2252     {
2253       /* Find the next ref that is not equal to the current ref.  */
2254       while (i + dist + 1 < count
2255 	     && df_mw_equal_p ((*mw_vec)[i], (*mw_vec)[i + dist + 1]))
2256 	{
2257 	  problem_data->mw_reg_pool->remove ((*mw_vec)[i + dist + 1]);
2258 	  dist++;
2259 	}
2260       /* Copy it down to the next position.  */
2261       if (dist && i + dist + 1 < count)
2262 	(*mw_vec)[i + 1] = (*mw_vec)[i + dist + 1];
2263     }
2264 
2265   count -= dist;
2266   mw_vec->truncate (count);
2267 }
2268 
2269 
2270 /* Sort and remove duplicates from the COLLECTION_REC.  */
2271 
2272 static void
df_canonize_collection_rec(struct df_collection_rec * collection_rec)2273 df_canonize_collection_rec (struct df_collection_rec *collection_rec)
2274 {
2275   df_sort_and_compress_refs (&collection_rec->def_vec);
2276   df_sort_and_compress_refs (&collection_rec->use_vec);
2277   df_sort_and_compress_refs (&collection_rec->eq_use_vec);
2278   df_sort_and_compress_mws (&collection_rec->mw_vec);
2279 }
2280 
2281 
2282 /* Add the new df_ref to appropriate reg_info/ref_info chains.  */
2283 
2284 static void
df_install_ref(df_ref this_ref,struct df_reg_info * reg_info,struct df_ref_info * ref_info,bool add_to_table)2285 df_install_ref (df_ref this_ref,
2286 		struct df_reg_info *reg_info,
2287 		struct df_ref_info *ref_info,
2288 		bool add_to_table)
2289 {
2290   unsigned int regno = DF_REF_REGNO (this_ref);
2291   /* Add the ref to the reg_{def,use,eq_use} chain.  */
2292   df_ref head = reg_info->reg_chain;
2293 
2294   reg_info->reg_chain = this_ref;
2295   reg_info->n_refs++;
2296 
2297   if (DF_REF_FLAGS_IS_SET (this_ref, DF_HARD_REG_LIVE))
2298     {
2299       gcc_assert (regno < FIRST_PSEUDO_REGISTER);
2300       df->hard_regs_live_count[regno]++;
2301     }
2302 
2303   gcc_checking_assert (DF_REF_NEXT_REG (this_ref) == NULL
2304 		       && DF_REF_PREV_REG (this_ref) == NULL);
2305 
2306   DF_REF_NEXT_REG (this_ref) = head;
2307 
2308   /* We cannot actually link to the head of the chain.  */
2309   DF_REF_PREV_REG (this_ref) = NULL;
2310 
2311   if (head)
2312     DF_REF_PREV_REG (head) = this_ref;
2313 
2314   if (add_to_table)
2315     {
2316       gcc_assert (ref_info->ref_order != DF_REF_ORDER_NO_TABLE);
2317       df_check_and_grow_ref_info (ref_info, 1);
2318       DF_REF_ID (this_ref) = ref_info->table_size;
2319       /* Add the ref to the big array of defs.  */
2320       ref_info->refs[ref_info->table_size] = this_ref;
2321       ref_info->table_size++;
2322     }
2323   else
2324     DF_REF_ID (this_ref) = -1;
2325 
2326   ref_info->total_size++;
2327 }
2328 
2329 
2330 /* This function takes one of the groups of refs (defs, uses or
2331    eq_uses) and installs the entire group into the insn.  It also adds
2332    each of these refs into the appropriate chains.  */
2333 
2334 static df_ref
df_install_refs(basic_block bb,const vec<df_ref,va_heap> * old_vec,struct df_reg_info ** reg_info,struct df_ref_info * ref_info,bool is_notes)2335 df_install_refs (basic_block bb,
2336 		 const vec<df_ref, va_heap> *old_vec,
2337 		 struct df_reg_info **reg_info,
2338 		 struct df_ref_info *ref_info,
2339 		 bool is_notes)
2340 {
2341   unsigned int count = old_vec->length ();
2342   if (count)
2343     {
2344       bool add_to_table;
2345       df_ref this_ref;
2346       unsigned int ix;
2347 
2348       switch (ref_info->ref_order)
2349 	{
2350 	case DF_REF_ORDER_UNORDERED_WITH_NOTES:
2351 	case DF_REF_ORDER_BY_REG_WITH_NOTES:
2352 	case DF_REF_ORDER_BY_INSN_WITH_NOTES:
2353 	  ref_info->ref_order = DF_REF_ORDER_UNORDERED_WITH_NOTES;
2354 	  add_to_table = true;
2355 	  break;
2356 	case DF_REF_ORDER_UNORDERED:
2357 	case DF_REF_ORDER_BY_REG:
2358 	case DF_REF_ORDER_BY_INSN:
2359 	  ref_info->ref_order = DF_REF_ORDER_UNORDERED;
2360 	  add_to_table = !is_notes;
2361 	  break;
2362 	default:
2363 	  add_to_table = false;
2364 	  break;
2365 	}
2366 
2367       /* Do not add if ref is not in the right blocks.  */
2368       if (add_to_table && df->analyze_subset)
2369 	add_to_table = bitmap_bit_p (df->blocks_to_analyze, bb->index);
2370 
2371       FOR_EACH_VEC_ELT (*old_vec, ix, this_ref)
2372 	{
2373 	  DF_REF_NEXT_LOC (this_ref) = (ix + 1 < old_vec->length ()
2374 					? (*old_vec)[ix + 1]
2375 					: NULL);
2376 	  df_install_ref (this_ref, reg_info[DF_REF_REGNO (this_ref)],
2377 			  ref_info, add_to_table);
2378 	}
2379       return (*old_vec)[0];
2380     }
2381   else
2382     return 0;
2383 }
2384 
2385 
2386 /* This function takes the mws installs the entire group into the
2387    insn.  */
2388 
2389 static struct df_mw_hardreg *
df_install_mws(const vec<df_mw_hardreg *,va_heap> * old_vec)2390 df_install_mws (const vec<df_mw_hardreg *, va_heap> *old_vec)
2391 {
2392   unsigned int count = old_vec->length ();
2393   if (count)
2394     {
2395       for (unsigned int i = 0; i < count - 1; i++)
2396 	DF_MWS_NEXT ((*old_vec)[i]) = (*old_vec)[i + 1];
2397       DF_MWS_NEXT ((*old_vec)[count - 1]) = 0;
2398       return (*old_vec)[0];
2399     }
2400   else
2401     return 0;
2402 }
2403 
2404 
2405 /* Add a chain of df_refs to appropriate ref chain/reg_info/ref_info
2406    chains and update other necessary information.  */
2407 
2408 static void
df_refs_add_to_chains(struct df_collection_rec * collection_rec,basic_block bb,rtx_insn * insn,unsigned int flags)2409 df_refs_add_to_chains (struct df_collection_rec *collection_rec,
2410 		       basic_block bb, rtx_insn *insn, unsigned int flags)
2411 {
2412   if (insn)
2413     {
2414       struct df_insn_info *insn_rec = DF_INSN_INFO_GET (insn);
2415       /* If there is a vector in the collection rec, add it to the
2416 	 insn.  A null rec is a signal that the caller will handle the
2417 	 chain specially.  */
2418       if (flags & copy_defs)
2419 	{
2420 	  gcc_checking_assert (!insn_rec->defs);
2421 	  insn_rec->defs
2422 	    = df_install_refs (bb, &collection_rec->def_vec,
2423 			       df->def_regs,
2424 			       &df->def_info, false);
2425 	}
2426       if (flags & copy_uses)
2427 	{
2428 	  gcc_checking_assert (!insn_rec->uses);
2429 	  insn_rec->uses
2430 	    = df_install_refs (bb, &collection_rec->use_vec,
2431 			       df->use_regs,
2432 			       &df->use_info, false);
2433 	}
2434       if (flags & copy_eq_uses)
2435 	{
2436 	  gcc_checking_assert (!insn_rec->eq_uses);
2437 	  insn_rec->eq_uses
2438 	    = df_install_refs (bb, &collection_rec->eq_use_vec,
2439 			       df->eq_use_regs,
2440 			       &df->use_info, true);
2441 	}
2442       if (flags & copy_mw)
2443 	{
2444 	  gcc_checking_assert (!insn_rec->mw_hardregs);
2445 	  insn_rec->mw_hardregs
2446 	    = df_install_mws (&collection_rec->mw_vec);
2447 	}
2448     }
2449   else
2450     {
2451       struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb->index);
2452 
2453       gcc_checking_assert (!bb_info->artificial_defs);
2454       bb_info->artificial_defs
2455 	= df_install_refs (bb, &collection_rec->def_vec,
2456 			   df->def_regs,
2457 			   &df->def_info, false);
2458       gcc_checking_assert (!bb_info->artificial_uses);
2459       bb_info->artificial_uses
2460 	= df_install_refs (bb, &collection_rec->use_vec,
2461 			   df->use_regs,
2462 			   &df->use_info, false);
2463     }
2464 }
2465 
2466 
2467 /* Allocate a ref and initialize its fields.  */
2468 
2469 static df_ref
df_ref_create_structure(enum df_ref_class cl,struct df_collection_rec * collection_rec,rtx reg,rtx * loc,basic_block bb,struct df_insn_info * info,enum df_ref_type ref_type,int ref_flags)2470 df_ref_create_structure (enum df_ref_class cl,
2471 			 struct df_collection_rec *collection_rec,
2472 			 rtx reg, rtx *loc,
2473 			 basic_block bb, struct df_insn_info *info,
2474 			 enum df_ref_type ref_type,
2475 			 int ref_flags)
2476 {
2477   df_ref this_ref = NULL;
2478   unsigned int regno = REGNO (GET_CODE (reg) == SUBREG ? SUBREG_REG (reg) : reg);
2479   struct df_scan_problem_data *problem_data
2480     = (struct df_scan_problem_data *) df_scan->problem_data;
2481 
2482   switch (cl)
2483     {
2484     case DF_REF_BASE:
2485       this_ref = (df_ref) (problem_data->ref_base_pool->allocate ());
2486       gcc_checking_assert (loc == NULL);
2487       break;
2488 
2489     case DF_REF_ARTIFICIAL:
2490       this_ref = (df_ref) (problem_data->ref_artificial_pool->allocate ());
2491       this_ref->artificial_ref.bb = bb;
2492       gcc_checking_assert (loc == NULL);
2493       break;
2494 
2495     case DF_REF_REGULAR:
2496       this_ref = (df_ref) (problem_data->ref_regular_pool->allocate ());
2497       this_ref->regular_ref.loc = loc;
2498       gcc_checking_assert (loc);
2499       break;
2500     }
2501 
2502   DF_REF_CLASS (this_ref) = cl;
2503   DF_REF_ID (this_ref) = -1;
2504   DF_REF_REG (this_ref) = reg;
2505   DF_REF_REGNO (this_ref) =  regno;
2506   DF_REF_TYPE (this_ref) = ref_type;
2507   DF_REF_INSN_INFO (this_ref) = info;
2508   DF_REF_CHAIN (this_ref) = NULL;
2509   DF_REF_FLAGS (this_ref) = ref_flags;
2510   DF_REF_NEXT_REG (this_ref) = NULL;
2511   DF_REF_PREV_REG (this_ref) = NULL;
2512   DF_REF_ORDER (this_ref) = df->ref_order++;
2513 
2514   /* We need to clear this bit because fwprop, and in the future
2515      possibly other optimizations sometimes create new refs using ond
2516      refs as the model.  */
2517   DF_REF_FLAGS_CLEAR (this_ref, DF_HARD_REG_LIVE);
2518 
2519   /* See if this ref needs to have DF_HARD_REG_LIVE bit set.  */
2520   if (regno < FIRST_PSEUDO_REGISTER
2521       && !DF_REF_IS_ARTIFICIAL (this_ref)
2522       && !DEBUG_INSN_P (DF_REF_INSN (this_ref)))
2523     {
2524       if (DF_REF_REG_DEF_P (this_ref))
2525 	{
2526 	  if (!DF_REF_FLAGS_IS_SET (this_ref, DF_REF_MAY_CLOBBER))
2527 	    DF_REF_FLAGS_SET (this_ref, DF_HARD_REG_LIVE);
2528 	}
2529       else if (!(TEST_HARD_REG_BIT (elim_reg_set, regno)
2530 		 && (regno == FRAME_POINTER_REGNUM
2531 		     || regno == ARG_POINTER_REGNUM)))
2532 	DF_REF_FLAGS_SET (this_ref, DF_HARD_REG_LIVE);
2533     }
2534 
2535   if (collection_rec)
2536     {
2537       if (DF_REF_REG_DEF_P (this_ref))
2538 	collection_rec->def_vec.safe_push (this_ref);
2539       else if (DF_REF_FLAGS (this_ref) & DF_REF_IN_NOTE)
2540 	collection_rec->eq_use_vec.safe_push (this_ref);
2541       else
2542 	collection_rec->use_vec.safe_push (this_ref);
2543     }
2544   else
2545     df_install_ref_incremental (this_ref);
2546 
2547   return this_ref;
2548 }
2549 
2550 
2551 /* Create new references of type DF_REF_TYPE for each part of register REG
2552    at address LOC within INSN of BB.  */
2553 
2554 
2555 static void
df_ref_record(enum df_ref_class cl,struct df_collection_rec * collection_rec,rtx reg,rtx * loc,basic_block bb,struct df_insn_info * insn_info,enum df_ref_type ref_type,int ref_flags)2556 df_ref_record (enum df_ref_class cl,
2557 	       struct df_collection_rec *collection_rec,
2558                rtx reg, rtx *loc,
2559 	       basic_block bb, struct df_insn_info *insn_info,
2560 	       enum df_ref_type ref_type,
2561 	       int ref_flags)
2562 {
2563   unsigned int regno;
2564 
2565   gcc_checking_assert (REG_P (reg) || GET_CODE (reg) == SUBREG);
2566 
2567   regno = REGNO (GET_CODE (reg) == SUBREG ? SUBREG_REG (reg) : reg);
2568   if (regno < FIRST_PSEUDO_REGISTER)
2569     {
2570       struct df_mw_hardreg *hardreg = NULL;
2571       struct df_scan_problem_data *problem_data
2572         = (struct df_scan_problem_data *) df_scan->problem_data;
2573       unsigned int i;
2574       unsigned int endregno;
2575       df_ref ref;
2576 
2577       if (GET_CODE (reg) == SUBREG)
2578 	{
2579 	  regno += subreg_regno_offset (regno, GET_MODE (SUBREG_REG (reg)),
2580 					SUBREG_BYTE (reg), GET_MODE (reg));
2581 	  endregno = regno + subreg_nregs (reg);
2582 	}
2583       else
2584 	endregno = END_REGNO (reg);
2585 
2586       /*  If this is a multiword hardreg, we create some extra
2587 	  datastructures that will enable us to easily build REG_DEAD
2588 	  and REG_UNUSED notes.  */
2589       if (collection_rec
2590 	  && (endregno != regno + 1) && insn_info)
2591 	{
2592 	  /* Sets to a subreg of a multiword register are partial.
2593 	     Sets to a non-subreg of a multiword register are not.  */
2594 	  if (GET_CODE (reg) == SUBREG)
2595 	    ref_flags |= DF_REF_PARTIAL;
2596 	  ref_flags |= DF_REF_MW_HARDREG;
2597 
2598 	  hardreg = problem_data->mw_reg_pool->allocate ();
2599 	  hardreg->type = ref_type;
2600 	  hardreg->flags = ref_flags;
2601 	  hardreg->mw_reg = reg;
2602 	  hardreg->start_regno = regno;
2603 	  hardreg->end_regno = endregno - 1;
2604 	  hardreg->mw_order = df->ref_order++;
2605 	  collection_rec->mw_vec.safe_push (hardreg);
2606 	}
2607 
2608       for (i = regno; i < endregno; i++)
2609 	{
2610 	  ref = df_ref_create_structure (cl, collection_rec, regno_reg_rtx[i], loc,
2611 					 bb, insn_info, ref_type, ref_flags);
2612 
2613           gcc_assert (ORIGINAL_REGNO (DF_REF_REG (ref)) == i);
2614 	}
2615     }
2616   else
2617     {
2618       df_ref_create_structure (cl, collection_rec, reg, loc, bb, insn_info,
2619 			       ref_type, ref_flags);
2620     }
2621 }
2622 
2623 
2624 /* Process all the registers defined in the rtx pointed by LOC.
2625    Autoincrement/decrement definitions will be picked up by df_uses_record.
2626    Any change here has to be matched in df_find_hard_reg_defs_1.  */
2627 
2628 static void
df_def_record_1(struct df_collection_rec * collection_rec,rtx * loc,basic_block bb,struct df_insn_info * insn_info,int flags)2629 df_def_record_1 (struct df_collection_rec *collection_rec,
2630                  rtx *loc, basic_block bb, struct df_insn_info *insn_info,
2631 		 int flags)
2632 {
2633   rtx dst = *loc;
2634 
2635   /* It is legal to have a set destination be a parallel. */
2636   if (GET_CODE (dst) == PARALLEL)
2637     {
2638       int i;
2639       for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
2640 	{
2641 	  rtx temp = XVECEXP (dst, 0, i);
2642 	  gcc_assert (GET_CODE (temp) == EXPR_LIST);
2643 	  df_def_record_1 (collection_rec, &XEXP (temp, 0),
2644 			   bb, insn_info, flags);
2645 	}
2646       return;
2647     }
2648 
2649   if (GET_CODE (dst) == STRICT_LOW_PART)
2650     {
2651       flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL | DF_REF_STRICT_LOW_PART;
2652 
2653       loc = &XEXP (dst, 0);
2654       dst = *loc;
2655     }
2656 
2657   if (GET_CODE (dst) == ZERO_EXTRACT)
2658     {
2659       flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL | DF_REF_ZERO_EXTRACT;
2660 
2661       loc = &XEXP (dst, 0);
2662       dst = *loc;
2663     }
2664 
2665   /* At this point if we do not have a reg or a subreg, just return.  */
2666   if (REG_P (dst))
2667     {
2668       df_ref_record (DF_REF_REGULAR, collection_rec,
2669 		     dst, loc, bb, insn_info, DF_REF_REG_DEF, flags);
2670 
2671       /* We want to keep sp alive everywhere - by making all
2672 	 writes to sp also use of sp. */
2673       if (REGNO (dst) == STACK_POINTER_REGNUM)
2674 	df_ref_record (DF_REF_BASE, collection_rec,
2675 		       dst, NULL, bb, insn_info, DF_REF_REG_USE, flags);
2676     }
2677   else if (GET_CODE (dst) == SUBREG && REG_P (SUBREG_REG (dst)))
2678     {
2679       if (read_modify_subreg_p (dst))
2680 	flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL;
2681 
2682       flags |= DF_REF_SUBREG;
2683 
2684       df_ref_record (DF_REF_REGULAR, collection_rec,
2685 		     dst, loc, bb, insn_info, DF_REF_REG_DEF, flags);
2686     }
2687 }
2688 
2689 
2690 /* Process all the registers defined in the pattern rtx, X.  Any change
2691    here has to be matched in df_find_hard_reg_defs.  */
2692 
2693 static void
df_defs_record(struct df_collection_rec * collection_rec,rtx x,basic_block bb,struct df_insn_info * insn_info,int flags)2694 df_defs_record (struct df_collection_rec *collection_rec,
2695                 rtx x, basic_block bb, struct df_insn_info *insn_info,
2696 		int flags)
2697 {
2698   RTX_CODE code = GET_CODE (x);
2699   int i;
2700 
2701   switch (code)
2702     {
2703     case SET:
2704       df_def_record_1 (collection_rec, &SET_DEST (x), bb, insn_info, flags);
2705       break;
2706 
2707     case CLOBBER:
2708       flags |= DF_REF_MUST_CLOBBER;
2709       df_def_record_1 (collection_rec, &XEXP (x, 0), bb, insn_info, flags);
2710       break;
2711 
2712     case COND_EXEC:
2713       df_defs_record (collection_rec, COND_EXEC_CODE (x),
2714 		      bb, insn_info, DF_REF_CONDITIONAL);
2715       break;
2716 
2717     case PARALLEL:
2718       for (i = 0; i < XVECLEN (x, 0); i++)
2719 	df_defs_record (collection_rec, XVECEXP (x, 0, i),
2720 			bb, insn_info, flags);
2721       break;
2722     default:
2723       /* No DEFs to record in other cases */
2724       break;
2725     }
2726 }
2727 
2728 /* Set bits in *DEFS for hard registers found in the rtx DST, which is the
2729    destination of a set or clobber.  This has to match the logic in
2730    df_defs_record_1.  */
2731 
2732 static void
df_find_hard_reg_defs_1(rtx dst,HARD_REG_SET * defs)2733 df_find_hard_reg_defs_1 (rtx dst, HARD_REG_SET *defs)
2734 {
2735   /* It is legal to have a set destination be a parallel. */
2736   if (GET_CODE (dst) == PARALLEL)
2737     {
2738       int i;
2739       for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
2740 	{
2741 	  rtx temp = XVECEXP (dst, 0, i);
2742 	  gcc_assert (GET_CODE (temp) == EXPR_LIST);
2743 	  df_find_hard_reg_defs_1 (XEXP (temp, 0), defs);
2744 	}
2745       return;
2746     }
2747 
2748   if (GET_CODE (dst) == STRICT_LOW_PART)
2749       dst = XEXP (dst, 0);
2750 
2751   if (GET_CODE (dst) == ZERO_EXTRACT)
2752       dst = XEXP (dst, 0);
2753 
2754   /* At this point if we do not have a reg or a subreg, just return.  */
2755   if (REG_P (dst) && HARD_REGISTER_P (dst))
2756     SET_HARD_REG_BIT (*defs, REGNO (dst));
2757   else if (GET_CODE (dst) == SUBREG
2758 	   && REG_P (SUBREG_REG (dst)) && HARD_REGISTER_P (dst))
2759     SET_HARD_REG_BIT (*defs, REGNO (SUBREG_REG (dst)));
2760 }
2761 
2762 /* Set bits in *DEFS for hard registers defined in the pattern X.  This
2763    has to match the logic in df_defs_record.  */
2764 
2765 static void
df_find_hard_reg_defs(rtx x,HARD_REG_SET * defs)2766 df_find_hard_reg_defs (rtx x, HARD_REG_SET *defs)
2767 {
2768   RTX_CODE code = GET_CODE (x);
2769   int i;
2770 
2771   switch (code)
2772     {
2773     case SET:
2774       df_find_hard_reg_defs_1 (SET_DEST (x), defs);
2775       break;
2776 
2777     case CLOBBER:
2778     case CLOBBER_HIGH:
2779       df_find_hard_reg_defs_1 (XEXP (x, 0), defs);
2780       break;
2781 
2782     case COND_EXEC:
2783       df_find_hard_reg_defs (COND_EXEC_CODE (x), defs);
2784       break;
2785 
2786     case PARALLEL:
2787       for (i = 0; i < XVECLEN (x, 0); i++)
2788 	df_find_hard_reg_defs (XVECEXP (x, 0, i), defs);
2789       break;
2790     default:
2791       /* No DEFs to record in other cases */
2792       break;
2793     }
2794 }
2795 
2796 
2797 /* Process all the registers used in the rtx at address LOC.  */
2798 
2799 static void
df_uses_record(struct df_collection_rec * collection_rec,rtx * loc,enum df_ref_type ref_type,basic_block bb,struct df_insn_info * insn_info,int flags)2800 df_uses_record (struct df_collection_rec *collection_rec,
2801                 rtx *loc, enum df_ref_type ref_type,
2802 		basic_block bb, struct df_insn_info *insn_info,
2803 		int flags)
2804 {
2805   RTX_CODE code;
2806   rtx x;
2807 
2808  retry:
2809   x = *loc;
2810   if (!x)
2811     return;
2812   code = GET_CODE (x);
2813   switch (code)
2814     {
2815     case LABEL_REF:
2816     case SYMBOL_REF:
2817     case CONST:
2818     CASE_CONST_ANY:
2819     case PC:
2820     case CC0:
2821     case ADDR_VEC:
2822     case ADDR_DIFF_VEC:
2823       return;
2824 
2825     case CLOBBER:
2826       /* If we are clobbering a MEM, mark any registers inside the address
2827 	 as being used.  */
2828       if (MEM_P (XEXP (x, 0)))
2829 	df_uses_record (collection_rec,
2830 			&XEXP (XEXP (x, 0), 0),
2831 			DF_REF_REG_MEM_STORE,
2832 		        bb, insn_info,
2833 			flags);
2834 
2835       /* If we're clobbering a REG then we have a def so ignore.  */
2836       return;
2837 
2838     case CLOBBER_HIGH:
2839       gcc_assert (REG_P (XEXP (x, 0)));
2840       return;
2841 
2842     case MEM:
2843       df_uses_record (collection_rec,
2844 		      &XEXP (x, 0), DF_REF_REG_MEM_LOAD,
2845 		      bb, insn_info, flags & DF_REF_IN_NOTE);
2846       return;
2847 
2848     case SUBREG:
2849       /* While we're here, optimize this case.  */
2850       flags |= DF_REF_PARTIAL;
2851       /* In case the SUBREG is not of a REG, do not optimize.  */
2852       if (!REG_P (SUBREG_REG (x)))
2853 	{
2854 	  loc = &SUBREG_REG (x);
2855 	  df_uses_record (collection_rec, loc, ref_type, bb, insn_info, flags);
2856 	  return;
2857 	}
2858       /* Fall through */
2859 
2860     case REG:
2861       df_ref_record (DF_REF_REGULAR, collection_rec,
2862 		     x, loc, bb, insn_info,
2863 		     ref_type, flags);
2864       return;
2865 
2866     case SIGN_EXTRACT:
2867     case ZERO_EXTRACT:
2868       {
2869         df_uses_record (collection_rec,
2870                         &XEXP (x, 1), ref_type, bb, insn_info, flags);
2871         df_uses_record (collection_rec,
2872                         &XEXP (x, 2), ref_type, bb, insn_info, flags);
2873 
2874         /* If the parameters to the zero or sign extract are
2875            constants, strip them off and recurse, otherwise there is
2876            no information that we can gain from this operation.  */
2877         if (code == ZERO_EXTRACT)
2878           flags |= DF_REF_ZERO_EXTRACT;
2879         else
2880           flags |= DF_REF_SIGN_EXTRACT;
2881 
2882         df_uses_record (collection_rec,
2883                         &XEXP (x, 0), ref_type, bb, insn_info, flags);
2884         return;
2885       }
2886       break;
2887 
2888     case SET:
2889       {
2890 	rtx dst = SET_DEST (x);
2891 	gcc_assert (!(flags & DF_REF_IN_NOTE));
2892 	df_uses_record (collection_rec,
2893 			&SET_SRC (x), DF_REF_REG_USE, bb, insn_info, flags);
2894 
2895 	switch (GET_CODE (dst))
2896 	  {
2897 	    case SUBREG:
2898 	      if (read_modify_subreg_p (dst))
2899 		{
2900 		  df_uses_record (collection_rec, &SUBREG_REG (dst),
2901 				  DF_REF_REG_USE, bb, insn_info,
2902 				  flags | DF_REF_READ_WRITE | DF_REF_SUBREG);
2903 		  break;
2904 		}
2905 	      /* Fall through.  */
2906 	    case REG:
2907 	    case PARALLEL:
2908 	    case SCRATCH:
2909 	    case PC:
2910 	    case CC0:
2911 		break;
2912 	    case MEM:
2913 	      df_uses_record (collection_rec, &XEXP (dst, 0),
2914 			      DF_REF_REG_MEM_STORE, bb, insn_info, flags);
2915 	      break;
2916 	    case STRICT_LOW_PART:
2917 	      {
2918 		rtx *temp = &XEXP (dst, 0);
2919 		/* A strict_low_part uses the whole REG and not just the
2920 		 SUBREG.  */
2921 		dst = XEXP (dst, 0);
2922 		df_uses_record (collection_rec,
2923 				(GET_CODE (dst) == SUBREG) ? &SUBREG_REG (dst) : temp,
2924 				DF_REF_REG_USE, bb, insn_info,
2925 				DF_REF_READ_WRITE | DF_REF_STRICT_LOW_PART);
2926 	      }
2927 	      break;
2928 	    case ZERO_EXTRACT:
2929 	      {
2930 		df_uses_record (collection_rec, &XEXP (dst, 1),
2931 				DF_REF_REG_USE, bb, insn_info, flags);
2932 		df_uses_record (collection_rec, &XEXP (dst, 2),
2933 				DF_REF_REG_USE, bb, insn_info, flags);
2934                 if (GET_CODE (XEXP (dst,0)) == MEM)
2935                   df_uses_record (collection_rec, &XEXP (dst, 0),
2936                                   DF_REF_REG_USE, bb, insn_info,
2937                                   flags);
2938                 else
2939                   df_uses_record (collection_rec, &XEXP (dst, 0),
2940                                   DF_REF_REG_USE, bb, insn_info,
2941                                   DF_REF_READ_WRITE | DF_REF_ZERO_EXTRACT);
2942 	      }
2943 	      break;
2944 
2945 	    default:
2946 	      gcc_unreachable ();
2947 	  }
2948 	return;
2949       }
2950 
2951     case RETURN:
2952     case SIMPLE_RETURN:
2953       break;
2954 
2955     case ASM_OPERANDS:
2956     case UNSPEC_VOLATILE:
2957     case TRAP_IF:
2958     case ASM_INPUT:
2959       {
2960 	/* Traditional and volatile asm instructions must be
2961 	   considered to use and clobber all hard registers, all
2962 	   pseudo-registers and all of memory.  So must TRAP_IF and
2963 	   UNSPEC_VOLATILE operations.
2964 
2965 	   Consider for instance a volatile asm that changes the fpu
2966 	   rounding mode.  An insn should not be moved across this
2967 	   even if it only uses pseudo-regs because it might give an
2968 	   incorrectly rounded result.
2969 
2970 	   However, flow.c's liveness computation did *not* do this,
2971 	   giving the reasoning as " ?!? Unfortunately, marking all
2972 	   hard registers as live causes massive problems for the
2973 	   register allocator and marking all pseudos as live creates
2974 	   mountains of uninitialized variable warnings."
2975 
2976 	   In order to maintain the status quo with regard to liveness
2977 	   and uses, we do what flow.c did and just mark any regs we
2978 	   can find in ASM_OPERANDS as used.  In global asm insns are
2979 	   scanned and regs_asm_clobbered is filled out.
2980 
2981 	   For all ASM_OPERANDS, we must traverse the vector of input
2982 	   operands.  We cannot just fall through here since then we
2983 	   would be confused by the ASM_INPUT rtx inside ASM_OPERANDS,
2984 	   which do not indicate traditional asms unlike their normal
2985 	   usage.  */
2986 	if (code == ASM_OPERANDS)
2987 	  {
2988 	    int j;
2989 
2990 	    for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++)
2991 	      df_uses_record (collection_rec, &ASM_OPERANDS_INPUT (x, j),
2992 			      DF_REF_REG_USE, bb, insn_info, flags);
2993 	    return;
2994 	  }
2995 	break;
2996       }
2997 
2998     case VAR_LOCATION:
2999       df_uses_record (collection_rec,
3000 		      &PAT_VAR_LOCATION_LOC (x),
3001 		      DF_REF_REG_USE, bb, insn_info, flags);
3002       return;
3003 
3004     case PRE_DEC:
3005     case POST_DEC:
3006     case PRE_INC:
3007     case POST_INC:
3008     case PRE_MODIFY:
3009     case POST_MODIFY:
3010       gcc_assert (!DEBUG_INSN_P (insn_info->insn));
3011       /* Catch the def of the register being modified.  */
3012       df_ref_record (DF_REF_REGULAR, collection_rec, XEXP (x, 0), &XEXP (x, 0),
3013 		     bb, insn_info,
3014 		     DF_REF_REG_DEF,
3015                      flags | DF_REF_READ_WRITE | DF_REF_PRE_POST_MODIFY);
3016 
3017       /* ... Fall through to handle uses ...  */
3018 
3019     default:
3020       break;
3021     }
3022 
3023   /* Recursively scan the operands of this expression.  */
3024   {
3025     const char *fmt = GET_RTX_FORMAT (code);
3026     int i;
3027 
3028     for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3029       {
3030 	if (fmt[i] == 'e')
3031 	  {
3032 	    /* Tail recursive case: save a function call level.  */
3033 	    if (i == 0)
3034 	      {
3035 		loc = &XEXP (x, 0);
3036 		goto retry;
3037 	      }
3038 	    df_uses_record (collection_rec, &XEXP (x, i), ref_type,
3039 			    bb, insn_info, flags);
3040 	  }
3041 	else if (fmt[i] == 'E')
3042 	  {
3043 	    int j;
3044 	    for (j = 0; j < XVECLEN (x, i); j++)
3045 	      df_uses_record (collection_rec,
3046 			      &XVECEXP (x, i, j), ref_type,
3047 			      bb, insn_info, flags);
3048 	  }
3049       }
3050   }
3051 
3052   return;
3053 }
3054 
3055 
3056 /* For all DF_REF_CONDITIONAL defs, add a corresponding uses.  */
3057 
3058 static void
df_get_conditional_uses(struct df_collection_rec * collection_rec)3059 df_get_conditional_uses (struct df_collection_rec *collection_rec)
3060 {
3061   unsigned int ix;
3062   df_ref ref;
3063 
3064   FOR_EACH_VEC_ELT (collection_rec->def_vec, ix, ref)
3065     {
3066       if (DF_REF_FLAGS_IS_SET (ref, DF_REF_CONDITIONAL))
3067         {
3068           df_ref use;
3069 
3070           use = df_ref_create_structure (DF_REF_CLASS (ref), collection_rec, DF_REF_REG (ref),
3071 					 DF_REF_LOC (ref), DF_REF_BB (ref),
3072 					 DF_REF_INSN_INFO (ref), DF_REF_REG_USE,
3073 					 DF_REF_FLAGS (ref) & ~DF_REF_CONDITIONAL);
3074           DF_REF_REGNO (use) = DF_REF_REGNO (ref);
3075         }
3076     }
3077 }
3078 
3079 
3080 /* Get call's extra defs and uses (track caller-saved registers). */
3081 
3082 static void
df_get_call_refs(struct df_collection_rec * collection_rec,basic_block bb,struct df_insn_info * insn_info,int flags)3083 df_get_call_refs (struct df_collection_rec *collection_rec,
3084                   basic_block bb,
3085                   struct df_insn_info *insn_info,
3086                   int flags)
3087 {
3088   rtx note;
3089   bool is_sibling_call;
3090   unsigned int i;
3091   HARD_REG_SET defs_generated;
3092   HARD_REG_SET fn_reg_set_usage;
3093 
3094   CLEAR_HARD_REG_SET (defs_generated);
3095   df_find_hard_reg_defs (PATTERN (insn_info->insn), &defs_generated);
3096   is_sibling_call = SIBLING_CALL_P (insn_info->insn);
3097   get_call_reg_set_usage (insn_info->insn, &fn_reg_set_usage,
3098 			  regs_invalidated_by_call);
3099 
3100   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3101     {
3102       if (i == STACK_POINTER_REGNUM)
3103 	/* The stack ptr is used (honorarily) by a CALL insn.  */
3104 	df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3105 		       NULL, bb, insn_info, DF_REF_REG_USE,
3106 		       DF_REF_CALL_STACK_USAGE | flags);
3107       else if (global_regs[i])
3108 	{
3109 	  /* Calls to const functions cannot access any global registers and
3110 	     calls to pure functions cannot set them.  All other calls may
3111 	     reference any of the global registers, so they are recorded as
3112 	     used. */
3113 	  if (!RTL_CONST_CALL_P (insn_info->insn))
3114 	    {
3115 	      df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3116 			     NULL, bb, insn_info, DF_REF_REG_USE, flags);
3117 	      if (!RTL_PURE_CALL_P (insn_info->insn))
3118 		df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3119 			       NULL, bb, insn_info, DF_REF_REG_DEF, flags);
3120 	    }
3121 	}
3122       else if (TEST_HARD_REG_BIT (fn_reg_set_usage, i)
3123 	       /* no clobbers for regs that are the result of the call */
3124 	       && !TEST_HARD_REG_BIT (defs_generated, i)
3125 	       && (!is_sibling_call
3126 		   || !bitmap_bit_p (df->exit_block_uses, i)
3127 		   || refers_to_regno_p (i, crtl->return_rtx)))
3128 	  df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3129 			 NULL, bb, insn_info, DF_REF_REG_DEF,
3130 			 DF_REF_MAY_CLOBBER | flags);
3131     }
3132 
3133   /* Record the registers used to pass arguments, and explicitly
3134      noted as clobbered.  */
3135   for (note = CALL_INSN_FUNCTION_USAGE (insn_info->insn); note;
3136        note = XEXP (note, 1))
3137     {
3138       gcc_assert (GET_CODE (XEXP (note, 0)) != CLOBBER_HIGH);
3139       if (GET_CODE (XEXP (note, 0)) == USE)
3140         df_uses_record (collection_rec, &XEXP (XEXP (note, 0), 0),
3141 			DF_REF_REG_USE, bb, insn_info, flags);
3142       else if (GET_CODE (XEXP (note, 0)) == CLOBBER)
3143 	{
3144 	  if (REG_P (XEXP (XEXP (note, 0), 0)))
3145 	    {
3146 	      unsigned int regno = REGNO (XEXP (XEXP (note, 0), 0));
3147 	      if (!TEST_HARD_REG_BIT (defs_generated, regno))
3148 		df_defs_record (collection_rec, XEXP (note, 0), bb,
3149 				insn_info, flags);
3150 	    }
3151 	  else
3152 	    df_uses_record (collection_rec, &XEXP (note, 0),
3153 		            DF_REF_REG_USE, bb, insn_info, flags);
3154 	}
3155     }
3156 
3157   return;
3158 }
3159 
3160 /* Collect all refs in the INSN. This function is free of any
3161    side-effect - it will create and return a lists of df_ref's in the
3162    COLLECTION_REC without putting those refs into existing ref chains
3163    and reg chains. */
3164 
3165 static void
df_insn_refs_collect(struct df_collection_rec * collection_rec,basic_block bb,struct df_insn_info * insn_info)3166 df_insn_refs_collect (struct df_collection_rec *collection_rec,
3167 		      basic_block bb, struct df_insn_info *insn_info)
3168 {
3169   rtx note;
3170   bool is_cond_exec = (GET_CODE (PATTERN (insn_info->insn)) == COND_EXEC);
3171 
3172   /* Clear out the collection record.  */
3173   collection_rec->def_vec.truncate (0);
3174   collection_rec->use_vec.truncate (0);
3175   collection_rec->eq_use_vec.truncate (0);
3176   collection_rec->mw_vec.truncate (0);
3177 
3178   /* Process REG_EQUIV/REG_EQUAL notes.  */
3179   for (note = REG_NOTES (insn_info->insn); note;
3180        note = XEXP (note, 1))
3181     {
3182       switch (REG_NOTE_KIND (note))
3183         {
3184         case REG_EQUIV:
3185         case REG_EQUAL:
3186           df_uses_record (collection_rec,
3187                           &XEXP (note, 0), DF_REF_REG_USE,
3188                           bb, insn_info, DF_REF_IN_NOTE);
3189           break;
3190         case REG_NON_LOCAL_GOTO:
3191           /* The frame ptr is used by a non-local goto.  */
3192           df_ref_record (DF_REF_BASE, collection_rec,
3193                          regno_reg_rtx[FRAME_POINTER_REGNUM],
3194                          NULL, bb, insn_info,
3195                          DF_REF_REG_USE, 0);
3196 	  if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
3197 	    df_ref_record (DF_REF_BASE, collection_rec,
3198 			   regno_reg_rtx[HARD_FRAME_POINTER_REGNUM],
3199 			   NULL, bb, insn_info,
3200 			   DF_REF_REG_USE, 0);
3201           break;
3202         default:
3203           break;
3204         }
3205     }
3206 
3207   int flags = (is_cond_exec) ? DF_REF_CONDITIONAL : 0;
3208   /* For CALL_INSNs, first record DF_REF_BASE register defs, as well as
3209      uses from CALL_INSN_FUNCTION_USAGE. */
3210   if (CALL_P (insn_info->insn))
3211     df_get_call_refs (collection_rec, bb, insn_info, flags);
3212 
3213   /* Record other defs.  These should be mostly for DF_REF_REGULAR, so
3214      that a qsort on the defs is unnecessary in most cases.  */
3215   df_defs_record (collection_rec,
3216 		  PATTERN (insn_info->insn), bb, insn_info, 0);
3217 
3218   /* Record the register uses.  */
3219   df_uses_record (collection_rec,
3220 		  &PATTERN (insn_info->insn), DF_REF_REG_USE, bb, insn_info, 0);
3221 
3222   /* DF_REF_CONDITIONAL needs corresponding USES. */
3223   if (is_cond_exec)
3224     df_get_conditional_uses (collection_rec);
3225 
3226   df_canonize_collection_rec (collection_rec);
3227 }
3228 
3229 /* Recompute the luids for the insns in BB.  */
3230 
3231 void
df_recompute_luids(basic_block bb)3232 df_recompute_luids (basic_block bb)
3233 {
3234   rtx_insn *insn;
3235   int luid = 0;
3236 
3237   df_grow_insn_info ();
3238 
3239   /* Scan the block an insn at a time from beginning to end.  */
3240   FOR_BB_INSNS (bb, insn)
3241     {
3242       struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
3243       /* Inserting labels does not always trigger the incremental
3244 	 rescanning.  */
3245       if (!insn_info)
3246 	{
3247 	  gcc_assert (!INSN_P (insn));
3248 	  insn_info = df_insn_create_insn_record (insn);
3249 	}
3250 
3251       DF_INSN_INFO_LUID (insn_info) = luid;
3252       if (INSN_P (insn))
3253 	luid++;
3254     }
3255 }
3256 
3257 
3258 /* Collect all artificial refs at the block level for BB and add them
3259    to COLLECTION_REC.  */
3260 
3261 static void
df_bb_refs_collect(struct df_collection_rec * collection_rec,basic_block bb)3262 df_bb_refs_collect (struct df_collection_rec *collection_rec, basic_block bb)
3263 {
3264   collection_rec->def_vec.truncate (0);
3265   collection_rec->use_vec.truncate (0);
3266   collection_rec->eq_use_vec.truncate (0);
3267   collection_rec->mw_vec.truncate (0);
3268 
3269   if (bb->index == ENTRY_BLOCK)
3270     {
3271       df_entry_block_defs_collect (collection_rec, df->entry_block_defs);
3272       return;
3273     }
3274   else if (bb->index == EXIT_BLOCK)
3275     {
3276       df_exit_block_uses_collect (collection_rec, df->exit_block_uses);
3277       return;
3278     }
3279 
3280   if (bb_has_eh_pred (bb))
3281     {
3282       unsigned int i;
3283       /* Mark the registers that will contain data for the handler.  */
3284       for (i = 0; ; ++i)
3285 	{
3286 	  unsigned regno = EH_RETURN_DATA_REGNO (i);
3287 	  if (regno == INVALID_REGNUM)
3288 	    break;
3289 	  df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[regno], NULL,
3290 			 bb, NULL, DF_REF_REG_DEF, DF_REF_AT_TOP);
3291 	}
3292     }
3293 
3294   /* Add the hard_frame_pointer if this block is the target of a
3295      non-local goto.  */
3296   if (bb->flags & BB_NON_LOCAL_GOTO_TARGET)
3297     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, hard_frame_pointer_rtx, NULL,
3298 		   bb, NULL, DF_REF_REG_DEF, DF_REF_AT_TOP);
3299 
3300   /* Add the artificial uses.  */
3301   if (bb->index >= NUM_FIXED_BLOCKS)
3302     {
3303       bitmap_iterator bi;
3304       unsigned int regno;
3305       bitmap au = bb_has_eh_pred (bb)
3306 	? &df->eh_block_artificial_uses
3307 	: &df->regular_block_artificial_uses;
3308 
3309       EXECUTE_IF_SET_IN_BITMAP (au, 0, regno, bi)
3310 	{
3311 	  df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[regno], NULL,
3312 			 bb, NULL, DF_REF_REG_USE, 0);
3313 	}
3314     }
3315 
3316   df_canonize_collection_rec (collection_rec);
3317 }
3318 
3319 
3320 /* Record all the refs within the basic block BB_INDEX and scan the instructions if SCAN_INSNS.  */
3321 
3322 void
df_bb_refs_record(int bb_index,bool scan_insns)3323 df_bb_refs_record (int bb_index, bool scan_insns)
3324 {
3325   basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
3326   rtx_insn *insn;
3327   int luid = 0;
3328 
3329   if (!df)
3330     return;
3331 
3332   df_collection_rec collection_rec;
3333   df_grow_bb_info (df_scan);
3334   if (scan_insns)
3335     /* Scan the block an insn at a time from beginning to end.  */
3336     FOR_BB_INSNS (bb, insn)
3337       {
3338 	struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
3339 	gcc_assert (!insn_info);
3340 
3341 	insn_info = df_insn_create_insn_record (insn);
3342 	if (INSN_P (insn))
3343 	  {
3344 	    /* Record refs within INSN.  */
3345 	    DF_INSN_INFO_LUID (insn_info) = luid++;
3346 	    df_insn_refs_collect (&collection_rec, bb, DF_INSN_INFO_GET (insn));
3347 	    df_refs_add_to_chains (&collection_rec, bb, insn, copy_all);
3348 	  }
3349 	DF_INSN_INFO_LUID (insn_info) = luid;
3350       }
3351 
3352   /* Other block level artificial refs */
3353   df_bb_refs_collect (&collection_rec, bb);
3354   df_refs_add_to_chains (&collection_rec, bb, NULL, copy_all);
3355 
3356   /* Now that the block has been processed, set the block as dirty so
3357      LR and LIVE will get it processed.  */
3358   df_set_bb_dirty (bb);
3359 }
3360 
3361 
3362 /* Get the artificial use set for a regular (i.e. non-exit/non-entry)
3363    block. */
3364 
3365 static void
df_get_regular_block_artificial_uses(bitmap regular_block_artificial_uses)3366 df_get_regular_block_artificial_uses (bitmap regular_block_artificial_uses)
3367 {
3368 #ifdef EH_USES
3369   unsigned int i;
3370 #endif
3371 
3372   bitmap_clear (regular_block_artificial_uses);
3373 
3374   if (reload_completed)
3375     {
3376       if (frame_pointer_needed)
3377 	bitmap_set_bit (regular_block_artificial_uses, HARD_FRAME_POINTER_REGNUM);
3378     }
3379   else
3380     /* Before reload, there are a few registers that must be forced
3381        live everywhere -- which might not already be the case for
3382        blocks within infinite loops.  */
3383     {
3384       unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3385 
3386       /* Any reference to any pseudo before reload is a potential
3387 	 reference of the frame pointer.  */
3388       bitmap_set_bit (regular_block_artificial_uses, FRAME_POINTER_REGNUM);
3389 
3390       if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
3391 	bitmap_set_bit (regular_block_artificial_uses,
3392 			HARD_FRAME_POINTER_REGNUM);
3393 
3394       /* Pseudos with argument area equivalences may require
3395 	 reloading via the argument pointer.  */
3396       if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3397 	  && fixed_regs[ARG_POINTER_REGNUM])
3398 	bitmap_set_bit (regular_block_artificial_uses, ARG_POINTER_REGNUM);
3399 
3400       /* Any constant, or pseudo with constant equivalences, may
3401 	 require reloading from memory using the pic register.  */
3402       if (picreg != INVALID_REGNUM
3403 	  && fixed_regs[picreg])
3404 	bitmap_set_bit (regular_block_artificial_uses, picreg);
3405     }
3406   /* The all-important stack pointer must always be live.  */
3407   bitmap_set_bit (regular_block_artificial_uses, STACK_POINTER_REGNUM);
3408 
3409 #ifdef EH_USES
3410   /* EH_USES registers are used:
3411      1) at all insns that might throw (calls or with -fnon-call-exceptions
3412 	trapping insns)
3413      2) in all EH edges
3414      3) to support backtraces and/or debugging, anywhere between their
3415 	initialization and where they the saved registers are restored
3416 	from them, including the cases where we don't reach the epilogue
3417 	(noreturn call or infinite loop).  */
3418   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3419     if (EH_USES (i))
3420       bitmap_set_bit (regular_block_artificial_uses, i);
3421 #endif
3422 }
3423 
3424 
3425 /* Get the artificial use set for an eh block. */
3426 
3427 static void
df_get_eh_block_artificial_uses(bitmap eh_block_artificial_uses)3428 df_get_eh_block_artificial_uses (bitmap eh_block_artificial_uses)
3429 {
3430   bitmap_clear (eh_block_artificial_uses);
3431 
3432   /* The following code (down through the arg_pointer setting APPEARS
3433      to be necessary because there is nothing that actually
3434      describes what the exception handling code may actually need
3435      to keep alive.  */
3436   if (reload_completed)
3437     {
3438       if (frame_pointer_needed)
3439 	{
3440 	  bitmap_set_bit (eh_block_artificial_uses, FRAME_POINTER_REGNUM);
3441 	  if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
3442 	    bitmap_set_bit (eh_block_artificial_uses,
3443 			    HARD_FRAME_POINTER_REGNUM);
3444 	}
3445       if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3446 	  && fixed_regs[ARG_POINTER_REGNUM])
3447 	bitmap_set_bit (eh_block_artificial_uses, ARG_POINTER_REGNUM);
3448     }
3449 }
3450 
3451 
3452 
3453 /*----------------------------------------------------------------------------
3454    Specialized hard register scanning functions.
3455 ----------------------------------------------------------------------------*/
3456 
3457 
3458 /* Mark a register in SET.  Hard registers in large modes get all
3459    of their component registers set as well.  */
3460 
3461 static void
df_mark_reg(rtx reg,void * vset)3462 df_mark_reg (rtx reg, void *vset)
3463 {
3464   bitmap_set_range ((bitmap) vset, REGNO (reg), REG_NREGS (reg));
3465 }
3466 
3467 
3468 /* Set the bit for regs that are considered being defined at the entry. */
3469 
3470 static void
df_get_entry_block_def_set(bitmap entry_block_defs)3471 df_get_entry_block_def_set (bitmap entry_block_defs)
3472 {
3473   rtx r;
3474   int i;
3475 
3476   bitmap_clear (entry_block_defs);
3477 
3478   /* For separate shrink-wrapping we use LIVE to analyze which basic blocks
3479      need a prologue for some component to be executed before that block,
3480      and we do not care about any other registers.  Hence, we do not want
3481      any register for any component defined in the entry block, and we can
3482      just leave all registers undefined.  */
3483   if (df_scan->local_flags & DF_SCAN_EMPTY_ENTRY_EXIT)
3484     return;
3485 
3486   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3487     {
3488       if (global_regs[i])
3489 	bitmap_set_bit (entry_block_defs, i);
3490       if (FUNCTION_ARG_REGNO_P (i))
3491 	bitmap_set_bit (entry_block_defs, INCOMING_REGNO (i));
3492     }
3493 
3494   /* The always important stack pointer.  */
3495   bitmap_set_bit (entry_block_defs, STACK_POINTER_REGNUM);
3496 
3497   /* Once the prologue has been generated, all of these registers
3498      should just show up in the first regular block.  */
3499   if (targetm.have_prologue () && epilogue_completed)
3500     {
3501       /* Defs for the callee saved registers are inserted so that the
3502 	 pushes have some defining location.  */
3503       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3504 	if ((call_used_regs[i] == 0) && (df_regs_ever_live_p (i)))
3505 	  bitmap_set_bit (entry_block_defs, i);
3506     }
3507 
3508   r = targetm.calls.struct_value_rtx (current_function_decl, true);
3509   if (r && REG_P (r))
3510     bitmap_set_bit (entry_block_defs, REGNO (r));
3511 
3512   /* If the function has an incoming STATIC_CHAIN, it has to show up
3513      in the entry def set.  */
3514   r = rtx_for_static_chain (current_function_decl, true);
3515   if (r && REG_P (r))
3516     bitmap_set_bit (entry_block_defs, REGNO (r));
3517 
3518   if ((!reload_completed) || frame_pointer_needed)
3519     {
3520       /* Any reference to any pseudo before reload is a potential
3521 	 reference of the frame pointer.  */
3522       bitmap_set_bit (entry_block_defs, FRAME_POINTER_REGNUM);
3523 
3524       /* If they are different, also mark the hard frame pointer as live.  */
3525       if (!HARD_FRAME_POINTER_IS_FRAME_POINTER
3526 	  && !LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM))
3527 	bitmap_set_bit (entry_block_defs, HARD_FRAME_POINTER_REGNUM);
3528     }
3529 
3530   /* These registers are live everywhere.  */
3531   if (!reload_completed)
3532     {
3533       /* Pseudos with argument area equivalences may require
3534 	 reloading via the argument pointer.  */
3535       if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3536 	  && fixed_regs[ARG_POINTER_REGNUM])
3537 	bitmap_set_bit (entry_block_defs, ARG_POINTER_REGNUM);
3538 
3539       /* Any constant, or pseudo with constant equivalences, may
3540 	 require reloading from memory using the pic register.  */
3541       unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3542       if (picreg != INVALID_REGNUM
3543 	  && fixed_regs[picreg])
3544 	bitmap_set_bit (entry_block_defs, picreg);
3545     }
3546 
3547 #ifdef INCOMING_RETURN_ADDR_RTX
3548   if (REG_P (INCOMING_RETURN_ADDR_RTX))
3549     bitmap_set_bit (entry_block_defs, REGNO (INCOMING_RETURN_ADDR_RTX));
3550 #endif
3551 
3552   targetm.extra_live_on_entry (entry_block_defs);
3553 }
3554 
3555 
3556 /* Return the (conservative) set of hard registers that are defined on
3557    entry to the function.
3558    It uses df->entry_block_defs to determine which register
3559    reference to include.  */
3560 
3561 static void
df_entry_block_defs_collect(struct df_collection_rec * collection_rec,bitmap entry_block_defs)3562 df_entry_block_defs_collect (struct df_collection_rec *collection_rec,
3563 			     bitmap entry_block_defs)
3564 {
3565   unsigned int i;
3566   bitmap_iterator bi;
3567 
3568   EXECUTE_IF_SET_IN_BITMAP (entry_block_defs, 0, i, bi)
3569     {
3570       df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[i], NULL,
3571 		     ENTRY_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_DEF, 0);
3572     }
3573 
3574   df_canonize_collection_rec (collection_rec);
3575 }
3576 
3577 
3578 /* Record the (conservative) set of hard registers that are defined on
3579    entry to the function.  */
3580 
3581 static void
df_record_entry_block_defs(bitmap entry_block_defs)3582 df_record_entry_block_defs (bitmap entry_block_defs)
3583 {
3584   struct df_collection_rec collection_rec;
3585   df_entry_block_defs_collect (&collection_rec, entry_block_defs);
3586 
3587   /* Process bb_refs chain */
3588   df_refs_add_to_chains (&collection_rec,
3589 			 BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK),
3590 			 NULL,
3591 			 copy_defs);
3592 }
3593 
3594 
3595 /* Update the defs in the entry block.  */
3596 
3597 void
df_update_entry_block_defs(void)3598 df_update_entry_block_defs (void)
3599 {
3600   bool changed = false;
3601 
3602   auto_bitmap refs (&df_bitmap_obstack);
3603   df_get_entry_block_def_set (refs);
3604   if (df->entry_block_defs)
3605     {
3606       if (!bitmap_equal_p (df->entry_block_defs, refs))
3607 	{
3608 	  struct df_scan_bb_info *bb_info = df_scan_get_bb_info (ENTRY_BLOCK);
3609 	  df_ref_chain_delete_du_chain (bb_info->artificial_defs);
3610 	  df_ref_chain_delete (bb_info->artificial_defs);
3611 	  bb_info->artificial_defs = NULL;
3612 	  changed = true;
3613 	}
3614     }
3615   else
3616     {
3617       struct df_scan_problem_data *problem_data
3618 	= (struct df_scan_problem_data *) df_scan->problem_data;
3619 	gcc_unreachable ();
3620       df->entry_block_defs = BITMAP_ALLOC (&problem_data->reg_bitmaps);
3621       changed = true;
3622     }
3623 
3624   if (changed)
3625     {
3626       df_record_entry_block_defs (refs);
3627       bitmap_copy (df->entry_block_defs, refs);
3628       df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK));
3629     }
3630 }
3631 
3632 
3633 /* Set the bit for regs that are considered being used at the exit. */
3634 
3635 static void
df_get_exit_block_use_set(bitmap exit_block_uses)3636 df_get_exit_block_use_set (bitmap exit_block_uses)
3637 {
3638   unsigned int i;
3639   unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3640 
3641   bitmap_clear (exit_block_uses);
3642 
3643   /* For separate shrink-wrapping we use LIVE to analyze which basic blocks
3644      need an epilogue for some component to be executed after that block,
3645      and we do not care about any other registers.  Hence, we do not want
3646      any register for any component seen as used in the exit block, and we
3647      can just say no registers at all are used.  */
3648   if (df_scan->local_flags & DF_SCAN_EMPTY_ENTRY_EXIT)
3649     return;
3650 
3651   /* Stack pointer is always live at the exit.  */
3652   bitmap_set_bit (exit_block_uses, STACK_POINTER_REGNUM);
3653 
3654   /* Mark the frame pointer if needed at the end of the function.
3655      If we end up eliminating it, it will be removed from the live
3656      list of each basic block by reload.  */
3657 
3658   if ((!reload_completed) || frame_pointer_needed)
3659     {
3660       bitmap_set_bit (exit_block_uses, FRAME_POINTER_REGNUM);
3661 
3662       /* If they are different, also mark the hard frame pointer as live.  */
3663       if (!HARD_FRAME_POINTER_IS_FRAME_POINTER
3664 	  && !LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM))
3665 	bitmap_set_bit (exit_block_uses, HARD_FRAME_POINTER_REGNUM);
3666     }
3667 
3668   /* Many architectures have a GP register even without flag_pic.
3669      Assume the pic register is not in use, or will be handled by
3670      other means, if it is not fixed.  */
3671   if (!PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
3672       && picreg != INVALID_REGNUM
3673       && fixed_regs[picreg])
3674     bitmap_set_bit (exit_block_uses, picreg);
3675 
3676   /* Mark all global registers, and all registers used by the
3677      epilogue as being live at the end of the function since they
3678      may be referenced by our caller.  */
3679   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3680     if (global_regs[i] || EPILOGUE_USES (i))
3681       bitmap_set_bit (exit_block_uses, i);
3682 
3683   if (targetm.have_epilogue () && epilogue_completed)
3684     {
3685       /* Mark all call-saved registers that we actually used.  */
3686       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3687 	if (df_regs_ever_live_p (i) && !LOCAL_REGNO (i)
3688 	    && !TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
3689 	  bitmap_set_bit (exit_block_uses, i);
3690     }
3691 
3692   /* Mark the registers that will contain data for the handler.  */
3693   if (reload_completed && crtl->calls_eh_return)
3694     for (i = 0; ; ++i)
3695       {
3696 	unsigned regno = EH_RETURN_DATA_REGNO (i);
3697 	if (regno == INVALID_REGNUM)
3698 	  break;
3699 	bitmap_set_bit (exit_block_uses, regno);
3700       }
3701 
3702 #ifdef EH_RETURN_STACKADJ_RTX
3703   if ((!targetm.have_epilogue () || ! epilogue_completed)
3704       && crtl->calls_eh_return)
3705     {
3706       rtx tmp = EH_RETURN_STACKADJ_RTX;
3707       if (tmp && REG_P (tmp))
3708 	df_mark_reg (tmp, exit_block_uses);
3709     }
3710 #endif
3711 
3712   if ((!targetm.have_epilogue () || ! epilogue_completed)
3713       && crtl->calls_eh_return)
3714     {
3715       rtx tmp = EH_RETURN_HANDLER_RTX;
3716       if (tmp && REG_P (tmp))
3717 	df_mark_reg (tmp, exit_block_uses);
3718     }
3719 
3720   /* Mark function return value.  */
3721   diddle_return_value (df_mark_reg, (void*) exit_block_uses);
3722 }
3723 
3724 
3725 /* Return the refs of hard registers that are used in the exit block.
3726    It uses df->exit_block_uses to determine register to include.  */
3727 
3728 static void
df_exit_block_uses_collect(struct df_collection_rec * collection_rec,bitmap exit_block_uses)3729 df_exit_block_uses_collect (struct df_collection_rec *collection_rec, bitmap exit_block_uses)
3730 {
3731   unsigned int i;
3732   bitmap_iterator bi;
3733 
3734   EXECUTE_IF_SET_IN_BITMAP (exit_block_uses, 0, i, bi)
3735     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[i], NULL,
3736 		   EXIT_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_USE, 0);
3737 
3738   /* It is deliberate that this is not put in the exit block uses but
3739      I do not know why.  */
3740   if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3741       && reload_completed
3742       && !bitmap_bit_p (exit_block_uses, ARG_POINTER_REGNUM)
3743       && bb_has_eh_pred (EXIT_BLOCK_PTR_FOR_FN (cfun))
3744       && fixed_regs[ARG_POINTER_REGNUM])
3745     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[ARG_POINTER_REGNUM], NULL,
3746 		   EXIT_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_USE, 0);
3747 
3748   df_canonize_collection_rec (collection_rec);
3749 }
3750 
3751 
3752 /* Record the set of hard registers that are used in the exit block.
3753    It uses df->exit_block_uses to determine which bit to include.  */
3754 
3755 static void
df_record_exit_block_uses(bitmap exit_block_uses)3756 df_record_exit_block_uses (bitmap exit_block_uses)
3757 {
3758   struct df_collection_rec collection_rec;
3759   df_exit_block_uses_collect (&collection_rec, exit_block_uses);
3760 
3761   /* Process bb_refs chain */
3762   df_refs_add_to_chains (&collection_rec,
3763 			 BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK),
3764 			 NULL,
3765 			 copy_uses);
3766 }
3767 
3768 
3769 /* Update the uses in the exit block.  */
3770 
3771 void
df_update_exit_block_uses(void)3772 df_update_exit_block_uses (void)
3773 {
3774   bool changed = false;
3775 
3776   auto_bitmap refs (&df_bitmap_obstack);
3777   df_get_exit_block_use_set (refs);
3778   if (df->exit_block_uses)
3779     {
3780       if (!bitmap_equal_p (df->exit_block_uses, refs))
3781 	{
3782 	  struct df_scan_bb_info *bb_info = df_scan_get_bb_info (EXIT_BLOCK);
3783 	  df_ref_chain_delete_du_chain (bb_info->artificial_uses);
3784 	  df_ref_chain_delete (bb_info->artificial_uses);
3785 	  bb_info->artificial_uses = NULL;
3786 	  changed = true;
3787 	}
3788     }
3789   else
3790     {
3791       struct df_scan_problem_data *problem_data
3792 	= (struct df_scan_problem_data *) df_scan->problem_data;
3793 	gcc_unreachable ();
3794       df->exit_block_uses = BITMAP_ALLOC (&problem_data->reg_bitmaps);
3795       changed = true;
3796     }
3797 
3798   if (changed)
3799     {
3800       df_record_exit_block_uses (refs);
3801       bitmap_copy (df->exit_block_uses, refs);
3802       df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK));
3803     }
3804 }
3805 
3806 static bool initialized = false;
3807 
3808 
3809 /* Initialize some platform specific structures.  */
3810 
3811 void
df_hard_reg_init(void)3812 df_hard_reg_init (void)
3813 {
3814   int i;
3815   static const struct {const int from, to; } eliminables[] = ELIMINABLE_REGS;
3816 
3817   if (initialized)
3818     return;
3819 
3820   /* Record which registers will be eliminated.  We use this in
3821      mark_used_regs.  */
3822   CLEAR_HARD_REG_SET (elim_reg_set);
3823 
3824   for (i = 0; i < (int) ARRAY_SIZE (eliminables); i++)
3825     SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from);
3826 
3827   initialized = true;
3828 }
3829 
3830 
3831 /* Recompute the parts of scanning that are based on regs_ever_live
3832    because something changed in that array.  */
3833 
3834 void
df_update_entry_exit_and_calls(void)3835 df_update_entry_exit_and_calls (void)
3836 {
3837   basic_block bb;
3838 
3839   df_update_entry_block_defs ();
3840   df_update_exit_block_uses ();
3841 
3842   /* The call insns need to be rescanned because there may be changes
3843      in the set of registers clobbered across the call.  */
3844   FOR_EACH_BB_FN (bb, cfun)
3845     {
3846       rtx_insn *insn;
3847       FOR_BB_INSNS (bb, insn)
3848 	{
3849 	  if (INSN_P (insn) && CALL_P (insn))
3850 	    df_insn_rescan (insn);
3851 	}
3852     }
3853 }
3854 
3855 
3856 /* Return true if hard REG is actually used in the some instruction.
3857    There are a fair number of conditions that affect the setting of
3858    this array.  See the comment in df.h for df->hard_regs_live_count
3859    for the conditions that this array is set. */
3860 
3861 bool
df_hard_reg_used_p(unsigned int reg)3862 df_hard_reg_used_p (unsigned int reg)
3863 {
3864   return df->hard_regs_live_count[reg] != 0;
3865 }
3866 
3867 
3868 /* A count of the number of times REG is actually used in the some
3869    instruction.  There are a fair number of conditions that affect the
3870    setting of this array.  See the comment in df.h for
3871    df->hard_regs_live_count for the conditions that this array is
3872    set. */
3873 
3874 
3875 unsigned int
df_hard_reg_used_count(unsigned int reg)3876 df_hard_reg_used_count (unsigned int reg)
3877 {
3878   return df->hard_regs_live_count[reg];
3879 }
3880 
3881 
3882 /* Get the value of regs_ever_live[REGNO].  */
3883 
3884 bool
df_regs_ever_live_p(unsigned int regno)3885 df_regs_ever_live_p (unsigned int regno)
3886 {
3887   return regs_ever_live[regno];
3888 }
3889 
3890 
3891 /* Set regs_ever_live[REGNO] to VALUE.  If this cause regs_ever_live
3892    to change, schedule that change for the next update.  */
3893 
3894 void
df_set_regs_ever_live(unsigned int regno,bool value)3895 df_set_regs_ever_live (unsigned int regno, bool value)
3896 {
3897   if (regs_ever_live[regno] == value)
3898     return;
3899 
3900   regs_ever_live[regno] = value;
3901   if (df)
3902     df->redo_entry_and_exit = true;
3903 }
3904 
3905 
3906 /* Compute "regs_ever_live" information from the underlying df
3907    information.  Set the vector to all false if RESET.  */
3908 
3909 void
df_compute_regs_ever_live(bool reset)3910 df_compute_regs_ever_live (bool reset)
3911 {
3912   unsigned int i;
3913   bool changed = df->redo_entry_and_exit;
3914 
3915   if (reset)
3916     memset (regs_ever_live, 0, sizeof (regs_ever_live));
3917 
3918   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3919     if ((!regs_ever_live[i]) && df_hard_reg_used_p (i))
3920       {
3921 	regs_ever_live[i] = true;
3922 	changed = true;
3923       }
3924   if (changed)
3925     df_update_entry_exit_and_calls ();
3926   df->redo_entry_and_exit = false;
3927 }
3928 
3929 
3930 /*----------------------------------------------------------------------------
3931   Dataflow ref information verification functions.
3932 
3933   df_reg_chain_mark (refs, regno, is_def, is_eq_use)
3934   df_reg_chain_verify_unmarked (refs)
3935   df_refs_verify (vec<stack, va_df_ref>, ref*, bool)
3936   df_mws_verify (mw*, mw*, bool)
3937   df_insn_refs_verify (collection_rec, bb, insn, bool)
3938   df_bb_refs_verify (bb, refs, bool)
3939   df_bb_verify (bb)
3940   df_exit_block_bitmap_verify (bool)
3941   df_entry_block_bitmap_verify (bool)
3942   df_scan_verify ()
3943 ----------------------------------------------------------------------------*/
3944 
3945 
3946 /* Mark all refs in the reg chain.  Verify that all of the registers
3947 are in the correct chain.  */
3948 
3949 static unsigned int
df_reg_chain_mark(df_ref refs,unsigned int regno,bool is_def,bool is_eq_use)3950 df_reg_chain_mark (df_ref refs, unsigned int regno,
3951 		   bool is_def, bool is_eq_use)
3952 {
3953   unsigned int count = 0;
3954   df_ref ref;
3955   for (ref = refs; ref; ref = DF_REF_NEXT_REG (ref))
3956     {
3957       gcc_assert (!DF_REF_IS_REG_MARKED (ref));
3958 
3959       /* If there are no def-use or use-def chains, make sure that all
3960 	 of the chains are clear.  */
3961       if (!df_chain)
3962 	gcc_assert (!DF_REF_CHAIN (ref));
3963 
3964       /* Check to make sure the ref is in the correct chain.  */
3965       gcc_assert (DF_REF_REGNO (ref) == regno);
3966       if (is_def)
3967 	gcc_assert (DF_REF_REG_DEF_P (ref));
3968       else
3969 	gcc_assert (!DF_REF_REG_DEF_P (ref));
3970 
3971       if (is_eq_use)
3972 	gcc_assert ((DF_REF_FLAGS (ref) & DF_REF_IN_NOTE));
3973       else
3974 	gcc_assert ((DF_REF_FLAGS (ref) & DF_REF_IN_NOTE) == 0);
3975 
3976       if (DF_REF_NEXT_REG (ref))
3977 	gcc_assert (DF_REF_PREV_REG (DF_REF_NEXT_REG (ref)) == ref);
3978       count++;
3979       DF_REF_REG_MARK (ref);
3980     }
3981   return count;
3982 }
3983 
3984 
3985 /* Verify that all of the registers in the chain are unmarked.  */
3986 
3987 static void
df_reg_chain_verify_unmarked(df_ref refs)3988 df_reg_chain_verify_unmarked (df_ref refs)
3989 {
3990   df_ref ref;
3991   for (ref = refs; ref; ref = DF_REF_NEXT_REG (ref))
3992     gcc_assert (!DF_REF_IS_REG_MARKED (ref));
3993 }
3994 
3995 
3996 /* Verify that NEW_REC and OLD_REC have exactly the same members. */
3997 
3998 static bool
df_refs_verify(const vec<df_ref,va_heap> * new_rec,df_ref old_rec,bool abort_if_fail)3999 df_refs_verify (const vec<df_ref, va_heap> *new_rec, df_ref old_rec,
4000 		bool abort_if_fail)
4001 {
4002   unsigned int ix;
4003   df_ref new_ref;
4004 
4005   FOR_EACH_VEC_ELT (*new_rec, ix, new_ref)
4006     {
4007       if (old_rec == NULL || !df_ref_equal_p (new_ref, old_rec))
4008 	{
4009 	  if (abort_if_fail)
4010 	    gcc_assert (0);
4011 	  else
4012 	    return false;
4013 	}
4014 
4015       /* Abort if fail is called from the function level verifier.  If
4016 	 that is the context, mark this reg as being seem.  */
4017       if (abort_if_fail)
4018 	{
4019 	  gcc_assert (DF_REF_IS_REG_MARKED (old_rec));
4020 	  DF_REF_REG_UNMARK (old_rec);
4021 	}
4022 
4023       old_rec = DF_REF_NEXT_LOC (old_rec);
4024     }
4025 
4026   if (abort_if_fail)
4027     gcc_assert (old_rec == NULL);
4028   else
4029     return old_rec == NULL;
4030   return false;
4031 }
4032 
4033 
4034 /* Verify that NEW_REC and OLD_REC have exactly the same members. */
4035 
4036 static bool
df_mws_verify(const vec<df_mw_hardreg *,va_heap> * new_rec,struct df_mw_hardreg * old_rec,bool abort_if_fail)4037 df_mws_verify (const vec<df_mw_hardreg *, va_heap> *new_rec,
4038 	       struct df_mw_hardreg *old_rec,
4039 	       bool abort_if_fail)
4040 {
4041   unsigned int ix;
4042   struct df_mw_hardreg *new_reg;
4043 
4044   FOR_EACH_VEC_ELT (*new_rec, ix, new_reg)
4045     {
4046       if (old_rec == NULL || !df_mw_equal_p (new_reg, old_rec))
4047 	{
4048 	  if (abort_if_fail)
4049 	    gcc_assert (0);
4050 	  else
4051 	    return false;
4052 	}
4053       old_rec = DF_MWS_NEXT (old_rec);
4054     }
4055 
4056   if (abort_if_fail)
4057     gcc_assert (old_rec == NULL);
4058   else
4059     return old_rec == NULL;
4060   return false;
4061 }
4062 
4063 
4064 /* Return true if the existing insn refs information is complete and
4065    correct. Otherwise (i.e. if there's any missing or extra refs),
4066    return the correct df_ref chain in REFS_RETURN.
4067 
4068    If ABORT_IF_FAIL, leave the refs that are verified (already in the
4069    ref chain) as DF_REF_MARKED(). If it's false, then it's a per-insn
4070    verification mode instead of the whole function, so unmark
4071    everything.
4072 
4073    If ABORT_IF_FAIL is set, this function never returns false.  */
4074 
4075 static bool
df_insn_refs_verify(struct df_collection_rec * collection_rec,basic_block bb,rtx_insn * insn,bool abort_if_fail)4076 df_insn_refs_verify (struct df_collection_rec *collection_rec,
4077 		     basic_block bb,
4078                      rtx_insn *insn,
4079 		     bool abort_if_fail)
4080 {
4081   bool ret1, ret2, ret3;
4082   unsigned int uid = INSN_UID (insn);
4083   struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
4084 
4085   df_insn_refs_collect (collection_rec, bb, insn_info);
4086 
4087   /* Unfortunately we cannot opt out early if one of these is not
4088      right and abort_if_fail is set because the marks will not get cleared.  */
4089   ret1 = df_refs_verify (&collection_rec->def_vec, DF_INSN_UID_DEFS (uid),
4090 			 abort_if_fail);
4091   if (!ret1 && !abort_if_fail)
4092     return false;
4093   ret2 = df_refs_verify (&collection_rec->use_vec, DF_INSN_UID_USES (uid),
4094 			 abort_if_fail);
4095   if (!ret2 && !abort_if_fail)
4096     return false;
4097   ret3 = df_refs_verify (&collection_rec->eq_use_vec, DF_INSN_UID_EQ_USES (uid),
4098 			 abort_if_fail);
4099   if (!ret3 && !abort_if_fail)
4100     return false;
4101   if (! df_mws_verify (&collection_rec->mw_vec, DF_INSN_UID_MWS (uid),
4102 		       abort_if_fail))
4103     return false;
4104   return (ret1 && ret2 && ret3);
4105 }
4106 
4107 
4108 /* Return true if all refs in the basic block are correct and complete.
4109    Due to df_ref_chain_verify, it will cause all refs
4110    that are verified to have DF_REF_MARK bit set.  */
4111 
4112 static bool
df_bb_verify(basic_block bb)4113 df_bb_verify (basic_block bb)
4114 {
4115   rtx_insn *insn;
4116   struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb->index);
4117   struct df_collection_rec collection_rec;
4118 
4119   gcc_assert (bb_info);
4120 
4121   /* Scan the block, one insn at a time, from beginning to end.  */
4122   FOR_BB_INSNS_REVERSE (bb, insn)
4123     {
4124       if (!INSN_P (insn))
4125         continue;
4126       df_insn_refs_verify (&collection_rec, bb, insn, true);
4127       df_free_collection_rec (&collection_rec);
4128     }
4129 
4130   /* Do the artificial defs and uses.  */
4131   df_bb_refs_collect (&collection_rec, bb);
4132   df_refs_verify (&collection_rec.def_vec, df_get_artificial_defs (bb->index), true);
4133   df_refs_verify (&collection_rec.use_vec, df_get_artificial_uses (bb->index), true);
4134   df_free_collection_rec (&collection_rec);
4135 
4136   return true;
4137 }
4138 
4139 
4140 /* Returns true if the entry block has correct and complete df_ref set.
4141    If not it either aborts if ABORT_IF_FAIL is true or returns false.  */
4142 
4143 static bool
df_entry_block_bitmap_verify(bool abort_if_fail)4144 df_entry_block_bitmap_verify (bool abort_if_fail)
4145 {
4146   bool is_eq;
4147 
4148   auto_bitmap entry_block_defs (&df_bitmap_obstack);
4149   df_get_entry_block_def_set (entry_block_defs);
4150 
4151   is_eq = bitmap_equal_p (entry_block_defs, df->entry_block_defs);
4152 
4153   if (!is_eq && abort_if_fail)
4154     {
4155       fprintf (stderr, "entry_block_defs = ");
4156       df_print_regset (stderr, entry_block_defs);
4157       fprintf (stderr, "df->entry_block_defs = ");
4158       df_print_regset (stderr, df->entry_block_defs);
4159       gcc_assert (0);
4160     }
4161 
4162   return is_eq;
4163 }
4164 
4165 
4166 /* Returns true if the exit block has correct and complete df_ref set.
4167    If not it either aborts if ABORT_IF_FAIL is true or returns false. */
4168 
4169 static bool
df_exit_block_bitmap_verify(bool abort_if_fail)4170 df_exit_block_bitmap_verify (bool abort_if_fail)
4171 {
4172   bool is_eq;
4173 
4174   auto_bitmap exit_block_uses (&df_bitmap_obstack);
4175   df_get_exit_block_use_set (exit_block_uses);
4176 
4177   is_eq = bitmap_equal_p (exit_block_uses, df->exit_block_uses);
4178 
4179   if (!is_eq && abort_if_fail)
4180     {
4181       fprintf (stderr, "exit_block_uses = ");
4182       df_print_regset (stderr, exit_block_uses);
4183       fprintf (stderr, "df->exit_block_uses = ");
4184       df_print_regset (stderr, df->exit_block_uses);
4185       gcc_assert (0);
4186     }
4187 
4188   return is_eq;
4189 }
4190 
4191 
4192 /* Return true if df_ref information for all insns in all blocks are
4193    correct and complete.  */
4194 
4195 void
df_scan_verify(void)4196 df_scan_verify (void)
4197 {
4198   unsigned int i;
4199   basic_block bb;
4200 
4201   if (!df)
4202     return;
4203 
4204   /* Verification is a 4 step process. */
4205 
4206   /* (1) All of the refs are marked by going through the reg chains.  */
4207   for (i = 0; i < DF_REG_SIZE (df); i++)
4208     {
4209       gcc_assert (df_reg_chain_mark (DF_REG_DEF_CHAIN (i), i, true, false)
4210 		  == DF_REG_DEF_COUNT (i));
4211       gcc_assert (df_reg_chain_mark (DF_REG_USE_CHAIN (i), i, false, false)
4212 		  == DF_REG_USE_COUNT (i));
4213       gcc_assert (df_reg_chain_mark (DF_REG_EQ_USE_CHAIN (i), i, false, true)
4214 		  == DF_REG_EQ_USE_COUNT (i));
4215     }
4216 
4217   /* (2) There are various bitmaps whose value may change over the
4218      course of the compilation.  This step recomputes them to make
4219      sure that they have not slipped out of date.  */
4220   auto_bitmap regular_block_artificial_uses (&df_bitmap_obstack);
4221   auto_bitmap eh_block_artificial_uses (&df_bitmap_obstack);
4222 
4223   df_get_regular_block_artificial_uses (regular_block_artificial_uses);
4224   df_get_eh_block_artificial_uses (eh_block_artificial_uses);
4225 
4226   bitmap_ior_into (eh_block_artificial_uses,
4227 		   regular_block_artificial_uses);
4228 
4229   /* Check artificial_uses bitmaps didn't change. */
4230   gcc_assert (bitmap_equal_p (regular_block_artificial_uses,
4231 			      &df->regular_block_artificial_uses));
4232   gcc_assert (bitmap_equal_p (eh_block_artificial_uses,
4233 			      &df->eh_block_artificial_uses));
4234 
4235   /* Verify entry block and exit block. These only verify the bitmaps,
4236      the refs are verified in df_bb_verify.  */
4237   df_entry_block_bitmap_verify (true);
4238   df_exit_block_bitmap_verify (true);
4239 
4240   /* (3) All of the insns in all of the blocks are traversed and the
4241      marks are cleared both in the artificial refs attached to the
4242      blocks and the real refs inside the insns.  It is a failure to
4243      clear a mark that has not been set as this means that the ref in
4244      the block or insn was not in the reg chain.  */
4245 
4246   FOR_ALL_BB_FN (bb, cfun)
4247     df_bb_verify (bb);
4248 
4249   /* (4) See if all reg chains are traversed a second time.  This time
4250      a check is made that the marks are clear. A set mark would be a
4251      from a reg that is not in any insn or basic block.  */
4252 
4253   for (i = 0; i < DF_REG_SIZE (df); i++)
4254     {
4255       df_reg_chain_verify_unmarked (DF_REG_DEF_CHAIN (i));
4256       df_reg_chain_verify_unmarked (DF_REG_USE_CHAIN (i));
4257       df_reg_chain_verify_unmarked (DF_REG_EQ_USE_CHAIN (i));
4258     }
4259 }
4260