xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/df-scan.c (revision cef8759bd76c1b621f8eab8faa6f208faabc2e15)
1 /* Scanning of rtl for dataflow analysis.
2    Copyright (C) 1999-2017 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 
38 
39 /* The set of hard registers in eliminables[i].from. */
40 
41 static HARD_REG_SET elim_reg_set;
42 
43 /* Initialize ur_in and ur_out as if all hard registers were partially
44    available.  */
45 
46 struct df_collection_rec
47 {
48   auto_vec<df_ref, 128> def_vec;
49   auto_vec<df_ref, 32> use_vec;
50   auto_vec<df_ref, 32> eq_use_vec;
51   auto_vec<df_mw_hardreg *, 32> mw_vec;
52 };
53 
54 static void df_ref_record (enum df_ref_class, struct df_collection_rec *,
55 			   rtx, rtx *,
56 			   basic_block, struct df_insn_info *,
57 			   enum df_ref_type, int ref_flags);
58 static void df_def_record_1 (struct df_collection_rec *, rtx *,
59 			     basic_block, struct df_insn_info *,
60 			     int ref_flags);
61 static void df_defs_record (struct df_collection_rec *, rtx,
62 			    basic_block, struct df_insn_info *,
63 			    int ref_flags);
64 static void df_uses_record (struct df_collection_rec *,
65 			    rtx *, enum df_ref_type,
66 			    basic_block, struct df_insn_info *,
67 			    int ref_flags);
68 
69 static void df_install_ref_incremental (df_ref);
70 static void df_insn_refs_collect (struct df_collection_rec*,
71 				  basic_block, struct df_insn_info *);
72 static void df_canonize_collection_rec (struct df_collection_rec *);
73 
74 static void df_get_regular_block_artificial_uses (bitmap);
75 static void df_get_eh_block_artificial_uses (bitmap);
76 
77 static void df_record_entry_block_defs (bitmap);
78 static void df_record_exit_block_uses (bitmap);
79 static void df_get_exit_block_use_set (bitmap);
80 static void df_get_entry_block_def_set (bitmap);
81 static void df_grow_ref_info (struct df_ref_info *, unsigned int);
82 static void df_ref_chain_delete_du_chain (df_ref);
83 static void df_ref_chain_delete (df_ref);
84 
85 static void df_refs_add_to_chains (struct df_collection_rec *,
86 				   basic_block, rtx_insn *, unsigned int);
87 
88 static bool df_insn_refs_verify (struct df_collection_rec *, basic_block,
89 				 rtx_insn *, bool);
90 static void df_entry_block_defs_collect (struct df_collection_rec *, bitmap);
91 static void df_exit_block_uses_collect (struct df_collection_rec *, bitmap);
92 static void df_install_ref (df_ref, struct df_reg_info *,
93 			    struct df_ref_info *, bool);
94 
95 static int df_ref_compare (df_ref, df_ref);
96 static int df_ref_ptr_compare (const void *, const void *);
97 static int df_mw_compare (const df_mw_hardreg *, const df_mw_hardreg *);
98 static int df_mw_ptr_compare (const void *, const void *);
99 
100 static void df_insn_info_delete (unsigned int);
101 
102 /* Indexed by hardware reg number, is true if that register is ever
103    used in the current function.
104 
105    In df-scan.c, this is set up to record the hard regs used
106    explicitly.  Reload adds in the hard regs used for holding pseudo
107    regs.  Final uses it to generate the code in the function prologue
108    and epilogue to save and restore registers as needed.  */
109 
110 static bool regs_ever_live[FIRST_PSEUDO_REGISTER];
111 
112 /* Flags used to tell df_refs_add_to_chains() which vectors it should copy. */
113 static const unsigned int copy_defs = 0x1;
114 static const unsigned int copy_uses = 0x2;
115 static const unsigned int copy_eq_uses = 0x4;
116 static const unsigned int copy_mw = 0x8;
117 static const unsigned int copy_all = copy_defs | copy_uses | copy_eq_uses
118 | copy_mw;
119 
120 /*----------------------------------------------------------------------------
121    SCANNING DATAFLOW PROBLEM
122 
123    There are several ways in which scanning looks just like the other
124    dataflow problems.  It shares the all the mechanisms for local info
125    as well as basic block info.  Where it differs is when and how often
126    it gets run.  It also has no need for the iterative solver.
127 ----------------------------------------------------------------------------*/
128 
129 /* Problem data for the scanning dataflow function.  */
130 struct df_scan_problem_data
131 {
132   object_allocator<df_base_ref> *ref_base_pool;
133   object_allocator<df_artificial_ref> *ref_artificial_pool;
134   object_allocator<df_regular_ref> *ref_regular_pool;
135   object_allocator<df_insn_info> *insn_pool;
136   object_allocator<df_reg_info> *reg_pool;
137   object_allocator<df_mw_hardreg> *mw_reg_pool;
138 
139   bitmap_obstack reg_bitmaps;
140   bitmap_obstack insn_bitmaps;
141 };
142 
143 /* Internal function to shut down the scanning problem.  */
144 static void
145 df_scan_free_internal (void)
146 {
147   struct df_scan_problem_data *problem_data
148     = (struct df_scan_problem_data *) df_scan->problem_data;
149 
150   free (df->def_info.refs);
151   free (df->def_info.begin);
152   free (df->def_info.count);
153   memset (&df->def_info, 0, (sizeof (struct df_ref_info)));
154 
155   free (df->use_info.refs);
156   free (df->use_info.begin);
157   free (df->use_info.count);
158   memset (&df->use_info, 0, (sizeof (struct df_ref_info)));
159 
160   free (df->def_regs);
161   df->def_regs = NULL;
162   free (df->use_regs);
163   df->use_regs = NULL;
164   free (df->eq_use_regs);
165   df->eq_use_regs = NULL;
166   df->regs_size = 0;
167   DF_REG_SIZE (df) = 0;
168 
169   free (df->insns);
170   df->insns = NULL;
171   DF_INSN_SIZE () = 0;
172 
173   free (df_scan->block_info);
174   df_scan->block_info = NULL;
175   df_scan->block_info_size = 0;
176 
177   bitmap_clear (&df->hardware_regs_used);
178   bitmap_clear (&df->regular_block_artificial_uses);
179   bitmap_clear (&df->eh_block_artificial_uses);
180   BITMAP_FREE (df->entry_block_defs);
181   BITMAP_FREE (df->exit_block_uses);
182   bitmap_clear (&df->insns_to_delete);
183   bitmap_clear (&df->insns_to_rescan);
184   bitmap_clear (&df->insns_to_notes_rescan);
185 
186   delete problem_data->ref_base_pool;
187   delete problem_data->ref_artificial_pool;
188   delete problem_data->ref_regular_pool;
189   delete problem_data->insn_pool;
190   delete problem_data->reg_pool;
191   delete problem_data->mw_reg_pool;
192   bitmap_obstack_release (&problem_data->reg_bitmaps);
193   bitmap_obstack_release (&problem_data->insn_bitmaps);
194   free (df_scan->problem_data);
195 }
196 
197 
198 /* Free basic block info.  */
199 
200 static void
201 df_scan_free_bb_info (basic_block bb, void *vbb_info)
202 {
203   struct df_scan_bb_info *bb_info = (struct df_scan_bb_info *) vbb_info;
204   unsigned int bb_index = bb->index;
205   rtx_insn *insn;
206 
207   FOR_BB_INSNS (bb, insn)
208     if (INSN_P (insn))
209       df_insn_info_delete (INSN_UID (insn));
210 
211   if (bb_index < df_scan->block_info_size)
212     bb_info = df_scan_get_bb_info (bb_index);
213 
214   /* Get rid of any artificial uses or defs.  */
215   df_ref_chain_delete_du_chain (bb_info->artificial_defs);
216   df_ref_chain_delete_du_chain (bb_info->artificial_uses);
217   df_ref_chain_delete (bb_info->artificial_defs);
218   df_ref_chain_delete (bb_info->artificial_uses);
219   bb_info->artificial_defs = NULL;
220   bb_info->artificial_uses = NULL;
221 }
222 
223 
224 /* Allocate the problem data for the scanning problem.  This should be
225    called when the problem is created or when the entire function is to
226    be rescanned.  */
227 void
228 df_scan_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
229 {
230   struct df_scan_problem_data *problem_data;
231   unsigned int insn_num = get_max_uid () + 1;
232   basic_block bb;
233 
234   /* Given the number of pools, this is really faster than tearing
235      everything apart.  */
236   if (df_scan->problem_data)
237     df_scan_free_internal ();
238 
239   problem_data = XNEW (struct df_scan_problem_data);
240   df_scan->problem_data = problem_data;
241   df_scan->computed = true;
242 
243   problem_data->ref_base_pool = new object_allocator<df_base_ref>
244     ("df_scan ref base");
245   problem_data->ref_artificial_pool = new object_allocator<df_artificial_ref>
246     ("df_scan ref artificial");
247   problem_data->ref_regular_pool = new object_allocator<df_regular_ref>
248     ("df_scan ref regular");
249   problem_data->insn_pool = new object_allocator<df_insn_info>
250     ("df_scan insn");
251   problem_data->reg_pool = new object_allocator<df_reg_info>
252     ("df_scan reg");
253   problem_data->mw_reg_pool = new object_allocator<df_mw_hardreg>
254     ("df_scan mw_reg");
255 
256   bitmap_obstack_initialize (&problem_data->reg_bitmaps);
257   bitmap_obstack_initialize (&problem_data->insn_bitmaps);
258 
259   insn_num += insn_num / 4;
260   df_grow_reg_info ();
261 
262   df_grow_insn_info ();
263   df_grow_bb_info (df_scan);
264 
265   FOR_ALL_BB_FN (bb, cfun)
266     {
267       unsigned int bb_index = bb->index;
268       struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb_index);
269       bb_info->artificial_defs = NULL;
270       bb_info->artificial_uses = NULL;
271     }
272 
273   bitmap_initialize (&df->hardware_regs_used, &problem_data->reg_bitmaps);
274   bitmap_initialize (&df->regular_block_artificial_uses, &problem_data->reg_bitmaps);
275   bitmap_initialize (&df->eh_block_artificial_uses, &problem_data->reg_bitmaps);
276   df->entry_block_defs = BITMAP_ALLOC (&problem_data->reg_bitmaps);
277   df->exit_block_uses = BITMAP_ALLOC (&problem_data->reg_bitmaps);
278   bitmap_initialize (&df->insns_to_delete, &problem_data->insn_bitmaps);
279   bitmap_initialize (&df->insns_to_rescan, &problem_data->insn_bitmaps);
280   bitmap_initialize (&df->insns_to_notes_rescan, &problem_data->insn_bitmaps);
281   df_scan->optional_p = false;
282 }
283 
284 
285 /* Free all of the data associated with the scan problem.  */
286 
287 static void
288 df_scan_free (void)
289 {
290   if (df_scan->problem_data)
291     df_scan_free_internal ();
292 
293   if (df->blocks_to_analyze)
294     {
295       BITMAP_FREE (df->blocks_to_analyze);
296       df->blocks_to_analyze = NULL;
297     }
298 
299   free (df_scan);
300 }
301 
302 /* Dump the preamble for DF_SCAN dump. */
303 static void
304 df_scan_start_dump (FILE *file ATTRIBUTE_UNUSED)
305 {
306   int i;
307   int dcount = 0;
308   int ucount = 0;
309   int ecount = 0;
310   int icount = 0;
311   int ccount = 0;
312   basic_block bb;
313   rtx_insn *insn;
314 
315   fprintf (file, ";;  invalidated by call \t");
316   df_print_regset (file, regs_invalidated_by_call_regset);
317   fprintf (file, ";;  hardware regs used \t");
318   df_print_regset (file, &df->hardware_regs_used);
319   fprintf (file, ";;  regular block artificial uses \t");
320   df_print_regset (file, &df->regular_block_artificial_uses);
321   fprintf (file, ";;  eh block artificial uses \t");
322   df_print_regset (file, &df->eh_block_artificial_uses);
323   fprintf (file, ";;  entry block defs \t");
324   df_print_regset (file, df->entry_block_defs);
325   fprintf (file, ";;  exit block uses \t");
326   df_print_regset (file, df->exit_block_uses);
327   fprintf (file, ";;  regs ever live \t");
328   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
329     if (df_regs_ever_live_p (i))
330       fprintf (file, " %d [%s]", i, reg_names[i]);
331   fprintf (file, "\n;;  ref usage \t");
332 
333   for (i = 0; i < (int)df->regs_inited; i++)
334     if (DF_REG_DEF_COUNT (i) || DF_REG_USE_COUNT (i) || DF_REG_EQ_USE_COUNT (i))
335       {
336 	const char * sep = "";
337 
338 	fprintf (file, "r%d={", i);
339 	if (DF_REG_DEF_COUNT (i))
340 	  {
341 	    fprintf (file, "%dd", DF_REG_DEF_COUNT (i));
342 	    sep = ",";
343 	    dcount += DF_REG_DEF_COUNT (i);
344 	  }
345 	if (DF_REG_USE_COUNT (i))
346 	  {
347 	    fprintf (file, "%s%du", sep, DF_REG_USE_COUNT (i));
348 	    sep = ",";
349 	    ucount += DF_REG_USE_COUNT (i);
350 	  }
351 	if (DF_REG_EQ_USE_COUNT (i))
352 	  {
353 	    fprintf (file, "%s%de", sep, DF_REG_EQ_USE_COUNT (i));
354 	    ecount += DF_REG_EQ_USE_COUNT (i);
355 	  }
356 	fprintf (file, "} ");
357       }
358 
359   FOR_EACH_BB_FN (bb, cfun)
360     FOR_BB_INSNS (bb, insn)
361       if (INSN_P (insn))
362 	{
363 	  if (CALL_P (insn))
364 	    ccount++;
365 	  else
366 	    icount++;
367 	}
368 
369   fprintf (file, "\n;;    total ref usage %d{%dd,%du,%de}"
370 		 " in %d{%d regular + %d call} insns.\n",
371 		 dcount + ucount + ecount, dcount, ucount, ecount,
372 		 icount + ccount, icount, ccount);
373 }
374 
375 /* Dump the bb_info for a given basic block. */
376 static void
377 df_scan_start_block (basic_block bb, FILE *file)
378 {
379   struct df_scan_bb_info *bb_info
380     = df_scan_get_bb_info (bb->index);
381 
382   if (bb_info)
383     {
384       fprintf (file, ";; bb %d artificial_defs: ", bb->index);
385       df_refs_chain_dump (bb_info->artificial_defs, true, file);
386       fprintf (file, "\n;; bb %d artificial_uses: ", bb->index);
387       df_refs_chain_dump (bb_info->artificial_uses, true, file);
388       fprintf (file, "\n");
389     }
390 #if 0
391   {
392     rtx_insn *insn;
393     FOR_BB_INSNS (bb, insn)
394       if (INSN_P (insn))
395 	df_insn_debug (insn, false, file);
396   }
397 #endif
398 }
399 
400 static const struct df_problem problem_SCAN =
401 {
402   DF_SCAN,                    /* Problem id.  */
403   DF_NONE,                    /* Direction.  */
404   df_scan_alloc,              /* Allocate the problem specific data.  */
405   NULL,                       /* Reset global information.  */
406   df_scan_free_bb_info,       /* Free basic block info.  */
407   NULL,                       /* Local compute function.  */
408   NULL,                       /* Init the solution specific data.  */
409   NULL,                       /* Iterative solver.  */
410   NULL,                       /* Confluence operator 0.  */
411   NULL,                       /* Confluence operator n.  */
412   NULL,                       /* Transfer function.  */
413   NULL,                       /* Finalize function.  */
414   df_scan_free,               /* Free all of the problem information.  */
415   NULL,                       /* Remove this problem from the stack of dataflow problems.  */
416   df_scan_start_dump,         /* Debugging.  */
417   df_scan_start_block,        /* Debugging start block.  */
418   NULL,                       /* Debugging end block.  */
419   NULL,                       /* Debugging start insn.  */
420   NULL,                       /* Debugging end insn.  */
421   NULL,                       /* Incremental solution verify start.  */
422   NULL,                       /* Incremental solution verify end.  */
423   NULL,                       /* Dependent problem.  */
424   sizeof (struct df_scan_bb_info),/* Size of entry of block_info array.  */
425   TV_DF_SCAN,                 /* Timing variable.  */
426   false                       /* Reset blocks on dropping out of blocks_to_analyze.  */
427 };
428 
429 
430 /* Create a new DATAFLOW instance and add it to an existing instance
431    of DF.  The returned structure is what is used to get at the
432    solution.  */
433 
434 void
435 df_scan_add_problem (void)
436 {
437   df_add_problem (&problem_SCAN);
438 }
439 
440 
441 /*----------------------------------------------------------------------------
442    Storage Allocation Utilities
443 ----------------------------------------------------------------------------*/
444 
445 
446 /* First, grow the reg_info information.  If the current size is less than
447    the number of pseudos, grow to 25% more than the number of
448    pseudos.
449 
450    Second, assure that all of the slots up to max_reg_num have been
451    filled with reg_info structures.  */
452 
453 void
454 df_grow_reg_info (void)
455 {
456   unsigned int max_reg = max_reg_num ();
457   unsigned int new_size = max_reg;
458   struct df_scan_problem_data *problem_data
459     = (struct df_scan_problem_data *) df_scan->problem_data;
460   unsigned int i;
461 
462   if (df->regs_size < new_size)
463     {
464       new_size += new_size / 4;
465       df->def_regs = XRESIZEVEC (struct df_reg_info *, df->def_regs, new_size);
466       df->use_regs = XRESIZEVEC (struct df_reg_info *, df->use_regs, new_size);
467       df->eq_use_regs = XRESIZEVEC (struct df_reg_info *, df->eq_use_regs,
468 				    new_size);
469       df->def_info.begin = XRESIZEVEC (unsigned, df->def_info.begin, new_size);
470       df->def_info.count = XRESIZEVEC (unsigned, df->def_info.count, new_size);
471       df->use_info.begin = XRESIZEVEC (unsigned, df->use_info.begin, new_size);
472       df->use_info.count = XRESIZEVEC (unsigned, df->use_info.count, new_size);
473       df->regs_size = new_size;
474     }
475 
476   for (i = df->regs_inited; i < max_reg; i++)
477     {
478       struct df_reg_info *reg_info;
479 
480       // TODO
481       reg_info = problem_data->reg_pool->allocate ();
482       memset (reg_info, 0, sizeof (struct df_reg_info));
483       df->def_regs[i] = reg_info;
484       reg_info = problem_data->reg_pool->allocate ();
485       memset (reg_info, 0, sizeof (struct df_reg_info));
486       df->use_regs[i] = reg_info;
487       reg_info = problem_data->reg_pool->allocate ();
488       memset (reg_info, 0, sizeof (struct df_reg_info));
489       df->eq_use_regs[i] = reg_info;
490       df->def_info.begin[i] = 0;
491       df->def_info.count[i] = 0;
492       df->use_info.begin[i] = 0;
493       df->use_info.count[i] = 0;
494     }
495 
496   df->regs_inited = max_reg;
497 }
498 
499 
500 /* Grow the ref information.  */
501 
502 static void
503 df_grow_ref_info (struct df_ref_info *ref_info, unsigned int new_size)
504 {
505   if (ref_info->refs_size < new_size)
506     {
507       ref_info->refs = XRESIZEVEC (df_ref, ref_info->refs, new_size);
508       memset (ref_info->refs + ref_info->refs_size, 0,
509 	      (new_size - ref_info->refs_size) *sizeof (df_ref));
510       ref_info->refs_size = new_size;
511     }
512 }
513 
514 
515 /* Check and grow the ref information if necessary.  This routine
516    guarantees total_size + BITMAP_ADDEND amount of entries in refs
517    array.  It updates ref_info->refs_size only and does not change
518    ref_info->total_size.  */
519 
520 static void
521 df_check_and_grow_ref_info (struct df_ref_info *ref_info,
522 			    unsigned bitmap_addend)
523 {
524   if (ref_info->refs_size < ref_info->total_size + bitmap_addend)
525     {
526       int new_size = ref_info->total_size + bitmap_addend;
527       new_size += ref_info->total_size / 4;
528       df_grow_ref_info (ref_info, new_size);
529     }
530 }
531 
532 
533 /* Grow the ref information.  If the current size is less than the
534    number of instructions, grow to 25% more than the number of
535    instructions.  */
536 
537 void
538 df_grow_insn_info (void)
539 {
540   unsigned int new_size = get_max_uid () + 1;
541   if (DF_INSN_SIZE () < new_size)
542     {
543       new_size += new_size / 4;
544       df->insns = XRESIZEVEC (struct df_insn_info *, df->insns, new_size);
545       memset (df->insns + df->insns_size, 0,
546 	      (new_size - DF_INSN_SIZE ()) *sizeof (struct df_insn_info *));
547       DF_INSN_SIZE () = new_size;
548     }
549 }
550 
551 
552 
553 
554 /*----------------------------------------------------------------------------
555    PUBLIC INTERFACES FOR SMALL GRAIN CHANGES TO SCANNING.
556 ----------------------------------------------------------------------------*/
557 
558 /* Rescan all of the block_to_analyze or all of the blocks in the
559    function if df_set_blocks if blocks_to_analyze is NULL;  */
560 
561 void
562 df_scan_blocks (void)
563 {
564   basic_block bb;
565 
566   df->def_info.ref_order = DF_REF_ORDER_NO_TABLE;
567   df->use_info.ref_order = DF_REF_ORDER_NO_TABLE;
568 
569   df_get_regular_block_artificial_uses (&df->regular_block_artificial_uses);
570   df_get_eh_block_artificial_uses (&df->eh_block_artificial_uses);
571 
572   bitmap_ior_into (&df->eh_block_artificial_uses,
573 		   &df->regular_block_artificial_uses);
574 
575   /* ENTRY and EXIT blocks have special defs/uses.  */
576   df_get_entry_block_def_set (df->entry_block_defs);
577   df_record_entry_block_defs (df->entry_block_defs);
578   df_get_exit_block_use_set (df->exit_block_uses);
579   df_record_exit_block_uses (df->exit_block_uses);
580   df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK));
581   df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK));
582 
583   /* Regular blocks */
584   FOR_EACH_BB_FN (bb, cfun)
585     {
586       unsigned int bb_index = bb->index;
587       df_bb_refs_record (bb_index, true);
588     }
589 }
590 
591 /* Create new refs under address LOC within INSN.  This function is
592    only used externally.  REF_FLAGS must be either 0 or DF_REF_IN_NOTE,
593    depending on whether LOC is inside PATTERN (INSN) or a note.  */
594 
595 void
596 df_uses_create (rtx *loc, rtx_insn *insn, int ref_flags)
597 {
598   gcc_assert (!(ref_flags & ~DF_REF_IN_NOTE));
599   df_uses_record (NULL, loc, DF_REF_REG_USE,
600                   BLOCK_FOR_INSN (insn),
601                   DF_INSN_INFO_GET (insn),
602                   ref_flags);
603 }
604 
605 static void
606 df_install_ref_incremental (df_ref ref)
607 {
608   struct df_reg_info **reg_info;
609   struct df_ref_info *ref_info;
610   df_ref *ref_ptr;
611   bool add_to_table;
612 
613   rtx_insn *insn = DF_REF_INSN (ref);
614   basic_block bb = BLOCK_FOR_INSN (insn);
615 
616   if (DF_REF_REG_DEF_P (ref))
617     {
618       reg_info = df->def_regs;
619       ref_info = &df->def_info;
620       ref_ptr = &DF_INSN_DEFS (insn);
621       add_to_table = ref_info->ref_order != DF_REF_ORDER_NO_TABLE;
622     }
623   else if (DF_REF_FLAGS (ref) & DF_REF_IN_NOTE)
624     {
625       reg_info = df->eq_use_regs;
626       ref_info = &df->use_info;
627       ref_ptr = &DF_INSN_EQ_USES (insn);
628       switch (ref_info->ref_order)
629 	{
630 	case DF_REF_ORDER_UNORDERED_WITH_NOTES:
631 	case DF_REF_ORDER_BY_REG_WITH_NOTES:
632 	case DF_REF_ORDER_BY_INSN_WITH_NOTES:
633 	  add_to_table = true;
634 	  break;
635 	default:
636 	  add_to_table = false;
637 	  break;
638 	}
639     }
640   else
641     {
642       reg_info = df->use_regs;
643       ref_info = &df->use_info;
644       ref_ptr = &DF_INSN_USES (insn);
645       add_to_table = ref_info->ref_order != DF_REF_ORDER_NO_TABLE;
646     }
647 
648   /* Do not add if ref is not in the right blocks.  */
649   if (add_to_table && df->analyze_subset)
650     add_to_table = bitmap_bit_p (df->blocks_to_analyze, bb->index);
651 
652   df_install_ref (ref, reg_info[DF_REF_REGNO (ref)], ref_info, add_to_table);
653 
654   if (add_to_table)
655     switch (ref_info->ref_order)
656       {
657       case DF_REF_ORDER_UNORDERED_WITH_NOTES:
658       case DF_REF_ORDER_BY_REG_WITH_NOTES:
659       case DF_REF_ORDER_BY_INSN_WITH_NOTES:
660 	ref_info->ref_order = DF_REF_ORDER_UNORDERED_WITH_NOTES;
661 	break;
662       default:
663 	ref_info->ref_order = DF_REF_ORDER_UNORDERED;
664 	break;
665       }
666 
667   while (*ref_ptr && df_ref_compare (*ref_ptr, ref) < 0)
668     ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
669 
670   DF_REF_NEXT_LOC (ref) = *ref_ptr;
671   *ref_ptr = ref;
672 
673 #if 0
674   if (dump_file)
675     {
676       fprintf (dump_file, "adding ref ");
677       df_ref_debug (ref, dump_file);
678     }
679 #endif
680   /* By adding the ref directly, df_insn_rescan my not find any
681      differences even though the block will have changed.  So we need
682      to mark the block dirty ourselves.  */
683   if (!DEBUG_INSN_P (DF_REF_INSN (ref)))
684     df_set_bb_dirty (bb);
685 }
686 
687 
688 
689 /*----------------------------------------------------------------------------
690    UTILITIES TO CREATE AND DESTROY REFS AND CHAINS.
691 ----------------------------------------------------------------------------*/
692 
693 static void
694 df_free_ref (df_ref ref)
695 {
696   struct df_scan_problem_data *problem_data
697     = (struct df_scan_problem_data *) df_scan->problem_data;
698 
699   switch (DF_REF_CLASS (ref))
700     {
701     case DF_REF_BASE:
702       problem_data->ref_base_pool->remove ((df_base_ref *) (ref));
703       break;
704 
705     case DF_REF_ARTIFICIAL:
706       problem_data->ref_artificial_pool->remove
707 	((df_artificial_ref *) (ref));
708       break;
709 
710     case DF_REF_REGULAR:
711       problem_data->ref_regular_pool->remove
712 	((df_regular_ref *) (ref));
713       break;
714     }
715 }
716 
717 
718 /* Unlink and delete REF at the reg_use, reg_eq_use or reg_def chain.
719    Also delete the def-use or use-def chain if it exists.  */
720 
721 static void
722 df_reg_chain_unlink (df_ref ref)
723 {
724   df_ref next = DF_REF_NEXT_REG (ref);
725   df_ref prev = DF_REF_PREV_REG (ref);
726   int id = DF_REF_ID (ref);
727   struct df_reg_info *reg_info;
728   df_ref *refs = NULL;
729 
730   if (DF_REF_REG_DEF_P (ref))
731     {
732       int regno = DF_REF_REGNO (ref);
733       reg_info = DF_REG_DEF_GET (regno);
734       refs = df->def_info.refs;
735     }
736   else
737     {
738       if (DF_REF_FLAGS (ref) & DF_REF_IN_NOTE)
739 	{
740 	  reg_info = DF_REG_EQ_USE_GET (DF_REF_REGNO (ref));
741 	  switch (df->use_info.ref_order)
742 	    {
743 	    case DF_REF_ORDER_UNORDERED_WITH_NOTES:
744 	    case DF_REF_ORDER_BY_REG_WITH_NOTES:
745 	    case DF_REF_ORDER_BY_INSN_WITH_NOTES:
746 	      refs = df->use_info.refs;
747 	      break;
748 	    default:
749 	      break;
750 	    }
751 	}
752       else
753 	{
754 	  reg_info = DF_REG_USE_GET (DF_REF_REGNO (ref));
755 	  refs = df->use_info.refs;
756 	}
757     }
758 
759   if (refs)
760     {
761       if (df->analyze_subset)
762 	{
763 	  if (bitmap_bit_p (df->blocks_to_analyze, DF_REF_BBNO (ref)))
764 	    refs[id] = NULL;
765 	}
766       else
767 	refs[id] = NULL;
768     }
769 
770   /* Delete any def-use or use-def chains that start here. It is
771      possible that there is trash in this field.  This happens for
772      insns that have been deleted when rescanning has been deferred
773      and the chain problem has also been deleted.  The chain tear down
774      code skips deleted insns.  */
775   if (df_chain && DF_REF_CHAIN (ref))
776     df_chain_unlink (ref);
777 
778   reg_info->n_refs--;
779   if (DF_REF_FLAGS_IS_SET (ref, DF_HARD_REG_LIVE))
780     {
781       gcc_assert (DF_REF_REGNO (ref) < FIRST_PSEUDO_REGISTER);
782       df->hard_regs_live_count[DF_REF_REGNO (ref)]--;
783     }
784 
785   /* Unlink from the reg chain.  If there is no prev, this is the
786      first of the list.  If not, just join the next and prev.  */
787   if (prev)
788     DF_REF_NEXT_REG (prev) = next;
789   else
790     {
791       gcc_assert (reg_info->reg_chain == ref);
792       reg_info->reg_chain = next;
793     }
794   if (next)
795     DF_REF_PREV_REG (next) = prev;
796 
797   df_free_ref (ref);
798 }
799 
800 /* Initialize INSN_INFO to describe INSN.  */
801 
802 static void
803 df_insn_info_init_fields (df_insn_info *insn_info, rtx_insn *insn)
804 {
805   memset (insn_info, 0, sizeof (struct df_insn_info));
806   insn_info->insn = insn;
807 }
808 
809 /* Create the insn record for INSN.  If there was one there, zero it
810    out.  */
811 
812 struct df_insn_info *
813 df_insn_create_insn_record (rtx_insn *insn)
814 {
815   struct df_scan_problem_data *problem_data
816     = (struct df_scan_problem_data *) df_scan->problem_data;
817   struct df_insn_info *insn_rec;
818 
819   df_grow_insn_info ();
820   insn_rec = DF_INSN_INFO_GET (insn);
821   if (!insn_rec)
822     {
823       insn_rec = problem_data->insn_pool->allocate ();
824       DF_INSN_INFO_SET (insn, insn_rec);
825     }
826   df_insn_info_init_fields (insn_rec, insn);
827   return insn_rec;
828 }
829 
830 
831 /* Delete all du chain (DF_REF_CHAIN()) of all refs in the ref chain.  */
832 
833 static void
834 df_ref_chain_delete_du_chain (df_ref ref)
835 {
836   for (; ref; ref = DF_REF_NEXT_LOC (ref))
837     /* CHAIN is allocated by DF_CHAIN. So make sure to
838        pass df_scan instance for the problem.  */
839     if (DF_REF_CHAIN (ref))
840       df_chain_unlink (ref);
841 }
842 
843 
844 /* Delete all refs in the ref chain.  */
845 
846 static void
847 df_ref_chain_delete (df_ref ref)
848 {
849   df_ref next;
850   for (; ref; ref = next)
851     {
852       next = DF_REF_NEXT_LOC (ref);
853       df_reg_chain_unlink (ref);
854     }
855 }
856 
857 
858 /* Delete the hardreg chain.  */
859 
860 static void
861 df_mw_hardreg_chain_delete (struct df_mw_hardreg *hardregs)
862 {
863   struct df_scan_problem_data *problem_data
864     = (struct df_scan_problem_data *) df_scan->problem_data;
865   df_mw_hardreg *next;
866 
867   for (; hardregs; hardregs = next)
868     {
869       next = DF_MWS_NEXT (hardregs);
870       problem_data->mw_reg_pool->remove (hardregs);
871     }
872 }
873 
874 /* Remove the contents of INSN_INFO (but don't free INSN_INFO itself).  */
875 
876 static void
877 df_insn_info_free_fields (df_insn_info *insn_info)
878 {
879   /* In general, notes do not have the insn_info fields
880      initialized.  However, combine deletes insns by changing them
881      to notes.  How clever.  So we cannot just check if it is a
882      valid insn before short circuiting this code, we need to see
883      if we actually initialized it.  */
884   df_mw_hardreg_chain_delete (insn_info->mw_hardregs);
885 
886   if (df_chain)
887     {
888       df_ref_chain_delete_du_chain (insn_info->defs);
889       df_ref_chain_delete_du_chain (insn_info->uses);
890       df_ref_chain_delete_du_chain (insn_info->eq_uses);
891     }
892 
893   df_ref_chain_delete (insn_info->defs);
894   df_ref_chain_delete (insn_info->uses);
895   df_ref_chain_delete (insn_info->eq_uses);
896 }
897 
898 /* Delete all of the refs information from the insn with UID.
899    Internal helper for df_insn_delete, df_insn_rescan, and other
900    df-scan routines that don't have to work in deferred mode
901    and do not have to mark basic blocks for re-processing.  */
902 
903 static void
904 df_insn_info_delete (unsigned int uid)
905 {
906   struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
907 
908   bitmap_clear_bit (&df->insns_to_delete, uid);
909   bitmap_clear_bit (&df->insns_to_rescan, uid);
910   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
911   if (insn_info)
912     {
913       struct df_scan_problem_data *problem_data
914 	= (struct df_scan_problem_data *) df_scan->problem_data;
915 
916       df_insn_info_free_fields (insn_info);
917       problem_data->insn_pool->remove (insn_info);
918       DF_INSN_UID_SET (uid, NULL);
919     }
920 }
921 
922 /* Delete all of the refs information from INSN, either right now
923    or marked for later in deferred mode.  */
924 
925 void
926 df_insn_delete (rtx_insn *insn)
927 {
928   unsigned int uid;
929   basic_block bb;
930 
931   gcc_checking_assert (INSN_P (insn));
932 
933   if (!df)
934     return;
935 
936   uid = INSN_UID (insn);
937   bb = BLOCK_FOR_INSN (insn);
938 
939   /* ??? bb can be NULL after pass_free_cfg.  At that point, DF should
940      not exist anymore (as mentioned in df-core.c: "The only requirement
941      [for DF] is that there be a correct control flow graph."  Clearly
942      that isn't the case after pass_free_cfg.  But DF is freed much later
943      because some back-ends want to use DF info even though the CFG is
944      already gone.  It's not clear to me whether that is safe, actually.
945      In any case, we expect BB to be non-NULL at least up to register
946      allocation, so disallow a non-NULL BB up to there.  Not perfect
947      but better than nothing...  */
948   gcc_checking_assert (bb != NULL || reload_completed);
949 
950   df_grow_bb_info (df_scan);
951   df_grow_reg_info ();
952 
953   /* The block must be marked as dirty now, rather than later as in
954      df_insn_rescan and df_notes_rescan because it may not be there at
955      rescanning time and the mark would blow up.
956      DEBUG_INSNs do not make a block's data flow solution dirty (at
957      worst the LUIDs are no longer contiguous).  */
958   if (bb != NULL && NONDEBUG_INSN_P (insn))
959     df_set_bb_dirty (bb);
960 
961   /* The client has deferred rescanning.  */
962   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
963     {
964       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
965       if (insn_info)
966 	{
967 	  bitmap_clear_bit (&df->insns_to_rescan, uid);
968 	  bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
969 	  bitmap_set_bit (&df->insns_to_delete, uid);
970 	}
971       if (dump_file)
972 	fprintf (dump_file, "deferring deletion of insn with uid = %d.\n", uid);
973       return;
974     }
975 
976   if (dump_file)
977     fprintf (dump_file, "deleting insn with uid = %d.\n", uid);
978 
979   df_insn_info_delete (uid);
980 }
981 
982 
983 /* Free all of the refs and the mw_hardregs in COLLECTION_REC.  */
984 
985 static void
986 df_free_collection_rec (struct df_collection_rec *collection_rec)
987 {
988   unsigned int ix;
989   struct df_scan_problem_data *problem_data
990     = (struct df_scan_problem_data *) df_scan->problem_data;
991   df_ref ref;
992   struct df_mw_hardreg *mw;
993 
994   FOR_EACH_VEC_ELT (collection_rec->def_vec, ix, ref)
995     df_free_ref (ref);
996   FOR_EACH_VEC_ELT (collection_rec->use_vec, ix, ref)
997     df_free_ref (ref);
998   FOR_EACH_VEC_ELT (collection_rec->eq_use_vec, ix, ref)
999     df_free_ref (ref);
1000   FOR_EACH_VEC_ELT (collection_rec->mw_vec, ix, mw)
1001     problem_data->mw_reg_pool->remove (mw);
1002 
1003   collection_rec->def_vec.release ();
1004   collection_rec->use_vec.release ();
1005   collection_rec->eq_use_vec.release ();
1006   collection_rec->mw_vec.release ();
1007 }
1008 
1009 /* Rescan INSN.  Return TRUE if the rescanning produced any changes.  */
1010 
1011 bool
1012 df_insn_rescan (rtx_insn *insn)
1013 {
1014   unsigned int uid = INSN_UID (insn);
1015   struct df_insn_info *insn_info = NULL;
1016   basic_block bb = BLOCK_FOR_INSN (insn);
1017   struct df_collection_rec collection_rec;
1018 
1019   if ((!df) || (!INSN_P (insn)))
1020     return false;
1021 
1022   if (!bb)
1023     {
1024       if (dump_file)
1025 	fprintf (dump_file, "no bb for insn with uid = %d.\n", uid);
1026       return false;
1027     }
1028 
1029   /* The client has disabled rescanning and plans to do it itself.  */
1030   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1031     return false;
1032 
1033   df_grow_bb_info (df_scan);
1034   df_grow_reg_info ();
1035 
1036   insn_info = DF_INSN_UID_SAFE_GET (uid);
1037 
1038   /* The client has deferred rescanning.  */
1039   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1040     {
1041       if (!insn_info)
1042 	{
1043 	  insn_info = df_insn_create_insn_record (insn);
1044 	  insn_info->defs = 0;
1045 	  insn_info->uses = 0;
1046 	  insn_info->eq_uses = 0;
1047 	  insn_info->mw_hardregs = 0;
1048 	}
1049       if (dump_file)
1050 	fprintf (dump_file, "deferring rescan insn with uid = %d.\n", uid);
1051 
1052       bitmap_clear_bit (&df->insns_to_delete, uid);
1053       bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1054       bitmap_set_bit (&df->insns_to_rescan, INSN_UID (insn));
1055       return false;
1056     }
1057 
1058   bitmap_clear_bit (&df->insns_to_delete, uid);
1059   bitmap_clear_bit (&df->insns_to_rescan, uid);
1060   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1061   if (insn_info)
1062     {
1063       int luid;
1064       bool the_same = df_insn_refs_verify (&collection_rec, bb, insn, false);
1065       /* If there's no change, return false. */
1066       if (the_same)
1067 	{
1068 	  df_free_collection_rec (&collection_rec);
1069 	  if (dump_file)
1070 	    fprintf (dump_file, "verify found no changes in insn with uid = %d.\n", uid);
1071 	  return false;
1072 	}
1073       if (dump_file)
1074 	fprintf (dump_file, "rescanning insn with uid = %d.\n", uid);
1075 
1076       /* There's change - we need to delete the existing info.
1077 	 Since the insn isn't moved, we can salvage its LUID.  */
1078       luid = DF_INSN_LUID (insn);
1079       df_insn_info_free_fields (insn_info);
1080       df_insn_info_init_fields (insn_info, insn);
1081       DF_INSN_LUID (insn) = luid;
1082     }
1083   else
1084     {
1085       struct df_insn_info *insn_info = df_insn_create_insn_record (insn);
1086       df_insn_refs_collect (&collection_rec, bb, insn_info);
1087       if (dump_file)
1088 	fprintf (dump_file, "scanning new insn with uid = %d.\n", uid);
1089     }
1090 
1091   df_refs_add_to_chains (&collection_rec, bb, insn, copy_all);
1092   if (!DEBUG_INSN_P (insn))
1093     df_set_bb_dirty (bb);
1094 
1095   return true;
1096 }
1097 
1098 /* Same as df_insn_rescan, but don't mark the basic block as
1099    dirty.  */
1100 
1101 bool
1102 df_insn_rescan_debug_internal (rtx_insn *insn)
1103 {
1104   unsigned int uid = INSN_UID (insn);
1105   struct df_insn_info *insn_info;
1106 
1107   gcc_assert (DEBUG_INSN_P (insn)
1108 	      && VAR_LOC_UNKNOWN_P (INSN_VAR_LOCATION_LOC (insn)));
1109 
1110   if (!df)
1111     return false;
1112 
1113   insn_info = DF_INSN_UID_SAFE_GET (INSN_UID (insn));
1114   if (!insn_info)
1115     return false;
1116 
1117   if (dump_file)
1118     fprintf (dump_file, "deleting debug_insn with uid = %d.\n", uid);
1119 
1120   bitmap_clear_bit (&df->insns_to_delete, uid);
1121   bitmap_clear_bit (&df->insns_to_rescan, uid);
1122   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1123 
1124   if (insn_info->defs == 0
1125       && insn_info->uses == 0
1126       && insn_info->eq_uses == 0
1127       && insn_info->mw_hardregs == 0)
1128     return false;
1129 
1130   df_mw_hardreg_chain_delete (insn_info->mw_hardregs);
1131 
1132   if (df_chain)
1133     {
1134       df_ref_chain_delete_du_chain (insn_info->defs);
1135       df_ref_chain_delete_du_chain (insn_info->uses);
1136       df_ref_chain_delete_du_chain (insn_info->eq_uses);
1137     }
1138 
1139   df_ref_chain_delete (insn_info->defs);
1140   df_ref_chain_delete (insn_info->uses);
1141   df_ref_chain_delete (insn_info->eq_uses);
1142 
1143   insn_info->defs = 0;
1144   insn_info->uses = 0;
1145   insn_info->eq_uses = 0;
1146   insn_info->mw_hardregs = 0;
1147 
1148   return true;
1149 }
1150 
1151 
1152 /* Rescan all of the insns in the function.  Note that the artificial
1153    uses and defs are not touched.  This function will destroy def-use
1154    or use-def chains.  */
1155 
1156 void
1157 df_insn_rescan_all (void)
1158 {
1159   bool no_insn_rescan = false;
1160   bool defer_insn_rescan = false;
1161   basic_block bb;
1162   bitmap_iterator bi;
1163   unsigned int uid;
1164   bitmap_head tmp;
1165 
1166   bitmap_initialize (&tmp, &df_bitmap_obstack);
1167 
1168   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1169     {
1170       df_clear_flags (DF_NO_INSN_RESCAN);
1171       no_insn_rescan = true;
1172     }
1173 
1174   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1175     {
1176       df_clear_flags (DF_DEFER_INSN_RESCAN);
1177       defer_insn_rescan = true;
1178     }
1179 
1180   bitmap_copy (&tmp, &df->insns_to_delete);
1181   EXECUTE_IF_SET_IN_BITMAP (&tmp, 0, uid, bi)
1182     {
1183       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1184       if (insn_info)
1185 	df_insn_info_delete (uid);
1186     }
1187 
1188   bitmap_clear (&tmp);
1189   bitmap_clear (&df->insns_to_delete);
1190   bitmap_clear (&df->insns_to_rescan);
1191   bitmap_clear (&df->insns_to_notes_rescan);
1192 
1193   FOR_EACH_BB_FN (bb, cfun)
1194     {
1195       rtx_insn *insn;
1196       FOR_BB_INSNS (bb, insn)
1197 	{
1198 	  df_insn_rescan (insn);
1199 	}
1200     }
1201 
1202   if (no_insn_rescan)
1203     df_set_flags (DF_NO_INSN_RESCAN);
1204   if (defer_insn_rescan)
1205     df_set_flags (DF_DEFER_INSN_RESCAN);
1206 }
1207 
1208 
1209 /* Process all of the deferred rescans or deletions.  */
1210 
1211 void
1212 df_process_deferred_rescans (void)
1213 {
1214   bool no_insn_rescan = false;
1215   bool defer_insn_rescan = false;
1216   bitmap_iterator bi;
1217   unsigned int uid;
1218   bitmap_head tmp;
1219 
1220   bitmap_initialize (&tmp, &df_bitmap_obstack);
1221 
1222   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1223     {
1224       df_clear_flags (DF_NO_INSN_RESCAN);
1225       no_insn_rescan = true;
1226     }
1227 
1228   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1229     {
1230       df_clear_flags (DF_DEFER_INSN_RESCAN);
1231       defer_insn_rescan = true;
1232     }
1233 
1234   if (dump_file)
1235     fprintf (dump_file, "starting the processing of deferred insns\n");
1236 
1237   bitmap_copy (&tmp, &df->insns_to_delete);
1238   EXECUTE_IF_SET_IN_BITMAP (&tmp, 0, uid, bi)
1239     {
1240       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1241       if (insn_info)
1242 	df_insn_info_delete (uid);
1243     }
1244 
1245   bitmap_copy (&tmp, &df->insns_to_rescan);
1246   EXECUTE_IF_SET_IN_BITMAP (&tmp, 0, uid, bi)
1247     {
1248       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1249       if (insn_info)
1250 	df_insn_rescan (insn_info->insn);
1251     }
1252 
1253   bitmap_copy (&tmp, &df->insns_to_notes_rescan);
1254   EXECUTE_IF_SET_IN_BITMAP (&tmp, 0, uid, bi)
1255     {
1256       struct df_insn_info *insn_info = DF_INSN_UID_SAFE_GET (uid);
1257       if (insn_info)
1258 	df_notes_rescan (insn_info->insn);
1259     }
1260 
1261   if (dump_file)
1262     fprintf (dump_file, "ending the processing of deferred insns\n");
1263 
1264   bitmap_clear (&tmp);
1265   bitmap_clear (&df->insns_to_delete);
1266   bitmap_clear (&df->insns_to_rescan);
1267   bitmap_clear (&df->insns_to_notes_rescan);
1268 
1269   if (no_insn_rescan)
1270     df_set_flags (DF_NO_INSN_RESCAN);
1271   if (defer_insn_rescan)
1272     df_set_flags (DF_DEFER_INSN_RESCAN);
1273 
1274   /* If someone changed regs_ever_live during this pass, fix up the
1275      entry and exit blocks.  */
1276   if (df->redo_entry_and_exit)
1277     {
1278       df_update_entry_exit_and_calls ();
1279       df->redo_entry_and_exit = false;
1280     }
1281 }
1282 
1283 
1284 /* Count the number of refs. Include the defs if INCLUDE_DEFS. Include
1285    the uses if INCLUDE_USES. Include the eq_uses if
1286    INCLUDE_EQ_USES.  */
1287 
1288 static unsigned int
1289 df_count_refs (bool include_defs, bool include_uses,
1290 	       bool include_eq_uses)
1291 {
1292   unsigned int regno;
1293   int size = 0;
1294   unsigned int m = df->regs_inited;
1295 
1296   for (regno = 0; regno < m; regno++)
1297     {
1298       if (include_defs)
1299 	size += DF_REG_DEF_COUNT (regno);
1300       if (include_uses)
1301 	size += DF_REG_USE_COUNT (regno);
1302       if (include_eq_uses)
1303 	size += DF_REG_EQ_USE_COUNT (regno);
1304     }
1305   return size;
1306 }
1307 
1308 
1309 /* Take build ref table for either the uses or defs from the reg-use
1310    or reg-def chains.  This version processes the refs in reg order
1311    which is likely to be best if processing the whole function.  */
1312 
1313 static void
1314 df_reorganize_refs_by_reg_by_reg (struct df_ref_info *ref_info,
1315 				  bool include_defs,
1316 				  bool include_uses,
1317 				  bool include_eq_uses)
1318 {
1319   unsigned int m = df->regs_inited;
1320   unsigned int regno;
1321   unsigned int offset = 0;
1322   unsigned int start;
1323 
1324   if (df->changeable_flags & DF_NO_HARD_REGS)
1325     {
1326       start = FIRST_PSEUDO_REGISTER;
1327       memset (ref_info->begin, 0, sizeof (int) * FIRST_PSEUDO_REGISTER);
1328       memset (ref_info->count, 0, sizeof (int) * FIRST_PSEUDO_REGISTER);
1329     }
1330   else
1331     start = 0;
1332 
1333   ref_info->total_size
1334     = df_count_refs (include_defs, include_uses, include_eq_uses);
1335 
1336   df_check_and_grow_ref_info (ref_info, 1);
1337 
1338   for (regno = start; regno < m; regno++)
1339     {
1340       int count = 0;
1341       ref_info->begin[regno] = offset;
1342       if (include_defs)
1343 	{
1344 	  df_ref ref = DF_REG_DEF_CHAIN (regno);
1345 	  while (ref)
1346 	    {
1347 	      ref_info->refs[offset] = ref;
1348 	      DF_REF_ID (ref) = offset++;
1349 	      count++;
1350 	      ref = DF_REF_NEXT_REG (ref);
1351 	      gcc_checking_assert (offset < ref_info->refs_size);
1352 	    }
1353 	}
1354       if (include_uses)
1355 	{
1356 	  df_ref ref = DF_REG_USE_CHAIN (regno);
1357 	  while (ref)
1358 	    {
1359 	      ref_info->refs[offset] = ref;
1360 	      DF_REF_ID (ref) = offset++;
1361 	      count++;
1362 	      ref = DF_REF_NEXT_REG (ref);
1363 	      gcc_checking_assert (offset < ref_info->refs_size);
1364 	    }
1365 	}
1366       if (include_eq_uses)
1367 	{
1368 	  df_ref ref = DF_REG_EQ_USE_CHAIN (regno);
1369 	  while (ref)
1370 	    {
1371 	      ref_info->refs[offset] = ref;
1372 	      DF_REF_ID (ref) = offset++;
1373 	      count++;
1374 	      ref = DF_REF_NEXT_REG (ref);
1375 	      gcc_checking_assert (offset < ref_info->refs_size);
1376 	    }
1377 	}
1378       ref_info->count[regno] = count;
1379     }
1380 
1381   /* The bitmap size is not decremented when refs are deleted.  So
1382      reset it now that we have squished out all of the empty
1383      slots.  */
1384   ref_info->table_size = offset;
1385 }
1386 
1387 
1388 /* Take build ref table for either the uses or defs from the reg-use
1389    or reg-def chains.  This version processes the refs in insn order
1390    which is likely to be best if processing some segment of the
1391    function.  */
1392 
1393 static void
1394 df_reorganize_refs_by_reg_by_insn (struct df_ref_info *ref_info,
1395 				   bool include_defs,
1396 				   bool include_uses,
1397 				   bool include_eq_uses)
1398 {
1399   bitmap_iterator bi;
1400   unsigned int bb_index;
1401   unsigned int m = df->regs_inited;
1402   unsigned int offset = 0;
1403   unsigned int r;
1404   unsigned int start
1405     = (df->changeable_flags & DF_NO_HARD_REGS) ? FIRST_PSEUDO_REGISTER : 0;
1406 
1407   memset (ref_info->begin, 0, sizeof (int) * df->regs_inited);
1408   memset (ref_info->count, 0, sizeof (int) * df->regs_inited);
1409 
1410   ref_info->total_size = df_count_refs (include_defs, include_uses, include_eq_uses);
1411   df_check_and_grow_ref_info (ref_info, 1);
1412 
1413   EXECUTE_IF_SET_IN_BITMAP (df->blocks_to_analyze, 0, bb_index, bi)
1414     {
1415       basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
1416       rtx_insn *insn;
1417       df_ref def, use;
1418 
1419       if (include_defs)
1420 	FOR_EACH_ARTIFICIAL_DEF (def, bb_index)
1421 	  {
1422 	    unsigned int regno = DF_REF_REGNO (def);
1423 	    ref_info->count[regno]++;
1424 	  }
1425       if (include_uses)
1426 	FOR_EACH_ARTIFICIAL_USE (use, bb_index)
1427 	  {
1428 	    unsigned int regno = DF_REF_REGNO (use);
1429 	    ref_info->count[regno]++;
1430 	  }
1431 
1432       FOR_BB_INSNS (bb, insn)
1433 	{
1434 	  if (INSN_P (insn))
1435 	    {
1436 	      struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
1437 
1438 	      if (include_defs)
1439 		FOR_EACH_INSN_INFO_DEF (def, insn_info)
1440 		  {
1441 		    unsigned int regno = DF_REF_REGNO (def);
1442 		    ref_info->count[regno]++;
1443 		  }
1444 	      if (include_uses)
1445 		FOR_EACH_INSN_INFO_USE (use, insn_info)
1446 		  {
1447 		    unsigned int regno = DF_REF_REGNO (use);
1448 		    ref_info->count[regno]++;
1449 		  }
1450 	      if (include_eq_uses)
1451 		FOR_EACH_INSN_INFO_EQ_USE (use, insn_info)
1452 		  {
1453 		    unsigned int regno = DF_REF_REGNO (use);
1454 		    ref_info->count[regno]++;
1455 		  }
1456 	    }
1457 	}
1458     }
1459 
1460   for (r = start; r < m; r++)
1461     {
1462       ref_info->begin[r] = offset;
1463       offset += ref_info->count[r];
1464       ref_info->count[r] = 0;
1465     }
1466 
1467   EXECUTE_IF_SET_IN_BITMAP (df->blocks_to_analyze, 0, bb_index, bi)
1468     {
1469       basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
1470       rtx_insn *insn;
1471       df_ref def, use;
1472 
1473       if (include_defs)
1474 	FOR_EACH_ARTIFICIAL_DEF (def, bb_index)
1475 	  {
1476 	    unsigned int regno = DF_REF_REGNO (def);
1477 	    if (regno >= start)
1478 	      {
1479 		unsigned int id
1480 		  = ref_info->begin[regno] + ref_info->count[regno]++;
1481 		DF_REF_ID (def) = id;
1482 		ref_info->refs[id] = def;
1483 	      }
1484 	  }
1485       if (include_uses)
1486 	FOR_EACH_ARTIFICIAL_USE (use, bb_index)
1487 	  {
1488 	    unsigned int regno = DF_REF_REGNO (def);
1489 	    if (regno >= start)
1490 	      {
1491 		unsigned int id
1492 		  = ref_info->begin[regno] + ref_info->count[regno]++;
1493 		DF_REF_ID (use) = id;
1494 		ref_info->refs[id] = use;
1495 	      }
1496 	  }
1497 
1498       FOR_BB_INSNS (bb, insn)
1499 	{
1500 	  if (INSN_P (insn))
1501 	    {
1502 	      struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
1503 
1504 	      if (include_defs)
1505 		FOR_EACH_INSN_INFO_DEF (def, insn_info)
1506 		  {
1507 		    unsigned int regno = DF_REF_REGNO (def);
1508 		    if (regno >= start)
1509 		      {
1510 			unsigned int id
1511 			  = ref_info->begin[regno] + ref_info->count[regno]++;
1512 			DF_REF_ID (def) = id;
1513 			ref_info->refs[id] = def;
1514 		      }
1515 		  }
1516 	      if (include_uses)
1517 		FOR_EACH_INSN_INFO_USE (use, insn_info)
1518 		  {
1519 		    unsigned int regno = DF_REF_REGNO (use);
1520 		    if (regno >= start)
1521 		      {
1522 			unsigned int id
1523 			  = ref_info->begin[regno] + ref_info->count[regno]++;
1524 			DF_REF_ID (use) = id;
1525 			ref_info->refs[id] = use;
1526 		      }
1527 		  }
1528 	      if (include_eq_uses)
1529 		FOR_EACH_INSN_INFO_EQ_USE (use, insn_info)
1530 		  {
1531 		    unsigned int regno = DF_REF_REGNO (use);
1532 		    if (regno >= start)
1533 		      {
1534 			unsigned int id
1535 			  = ref_info->begin[regno] + ref_info->count[regno]++;
1536 			DF_REF_ID (use) = id;
1537 			ref_info->refs[id] = use;
1538 		      }
1539 		  }
1540 	    }
1541 	}
1542     }
1543 
1544   /* The bitmap size is not decremented when refs are deleted.  So
1545      reset it now that we have squished out all of the empty
1546      slots.  */
1547 
1548   ref_info->table_size = offset;
1549 }
1550 
1551 /* Take build ref table for either the uses or defs from the reg-use
1552    or reg-def chains.  */
1553 
1554 static void
1555 df_reorganize_refs_by_reg (struct df_ref_info *ref_info,
1556 			   bool include_defs,
1557 			   bool include_uses,
1558 			   bool include_eq_uses)
1559 {
1560   if (df->analyze_subset)
1561     df_reorganize_refs_by_reg_by_insn (ref_info, include_defs,
1562 				       include_uses, include_eq_uses);
1563   else
1564     df_reorganize_refs_by_reg_by_reg (ref_info, include_defs,
1565 				       include_uses, include_eq_uses);
1566 }
1567 
1568 
1569 /* Add the refs in REF_VEC to the table in REF_INFO starting at OFFSET.  */
1570 static unsigned int
1571 df_add_refs_to_table (unsigned int offset,
1572 		      struct df_ref_info *ref_info,
1573 		      df_ref ref)
1574 {
1575   for (; ref; ref = DF_REF_NEXT_LOC (ref))
1576     if (!(df->changeable_flags & DF_NO_HARD_REGS)
1577 	|| (DF_REF_REGNO (ref) >= FIRST_PSEUDO_REGISTER))
1578       {
1579 	ref_info->refs[offset] = ref;
1580 	DF_REF_ID (ref) = offset++;
1581       }
1582   return offset;
1583 }
1584 
1585 
1586 /* Count the number of refs in all of the insns of BB. Include the
1587    defs if INCLUDE_DEFS. Include the uses if INCLUDE_USES. Include the
1588    eq_uses if INCLUDE_EQ_USES.  */
1589 
1590 static unsigned int
1591 df_reorganize_refs_by_insn_bb (basic_block bb, unsigned int offset,
1592 			       struct df_ref_info *ref_info,
1593 			       bool include_defs, bool include_uses,
1594 			       bool include_eq_uses)
1595 {
1596   rtx_insn *insn;
1597 
1598   if (include_defs)
1599     offset = df_add_refs_to_table (offset, ref_info,
1600 				   df_get_artificial_defs (bb->index));
1601   if (include_uses)
1602     offset = df_add_refs_to_table (offset, ref_info,
1603 				   df_get_artificial_uses (bb->index));
1604 
1605   FOR_BB_INSNS (bb, insn)
1606     if (INSN_P (insn))
1607       {
1608 	unsigned int uid = INSN_UID (insn);
1609 	if (include_defs)
1610 	  offset = df_add_refs_to_table (offset, ref_info,
1611 					 DF_INSN_UID_DEFS (uid));
1612 	if (include_uses)
1613 	  offset = df_add_refs_to_table (offset, ref_info,
1614 					 DF_INSN_UID_USES (uid));
1615 	if (include_eq_uses)
1616 	  offset = df_add_refs_to_table (offset, ref_info,
1617 					 DF_INSN_UID_EQ_USES (uid));
1618       }
1619   return offset;
1620 }
1621 
1622 
1623 /* Organize the refs by insn into the table in REF_INFO.  If
1624    blocks_to_analyze is defined, use that set, otherwise the entire
1625    program.  Include the defs if INCLUDE_DEFS. Include the uses if
1626    INCLUDE_USES. Include the eq_uses if INCLUDE_EQ_USES.  */
1627 
1628 static void
1629 df_reorganize_refs_by_insn (struct df_ref_info *ref_info,
1630 			    bool include_defs, bool include_uses,
1631 			    bool include_eq_uses)
1632 {
1633   basic_block bb;
1634   unsigned int offset = 0;
1635 
1636   ref_info->total_size = df_count_refs (include_defs, include_uses, include_eq_uses);
1637   df_check_and_grow_ref_info (ref_info, 1);
1638   if (df->blocks_to_analyze)
1639     {
1640       bitmap_iterator bi;
1641       unsigned int index;
1642 
1643       EXECUTE_IF_SET_IN_BITMAP (df->blocks_to_analyze, 0, index, bi)
1644 	{
1645 	  offset = df_reorganize_refs_by_insn_bb (BASIC_BLOCK_FOR_FN (cfun,
1646 								      index),
1647 						  offset, ref_info,
1648 						  include_defs, include_uses,
1649 						  include_eq_uses);
1650 	}
1651 
1652       ref_info->table_size = offset;
1653     }
1654   else
1655     {
1656       FOR_ALL_BB_FN (bb, cfun)
1657 	offset = df_reorganize_refs_by_insn_bb (bb, offset, ref_info,
1658 						include_defs, include_uses,
1659 						include_eq_uses);
1660       ref_info->table_size = offset;
1661     }
1662 }
1663 
1664 
1665 /* If the use refs in DF are not organized, reorganize them.  */
1666 
1667 void
1668 df_maybe_reorganize_use_refs (enum df_ref_order order)
1669 {
1670   if (order == df->use_info.ref_order)
1671     return;
1672 
1673   switch (order)
1674     {
1675     case DF_REF_ORDER_BY_REG:
1676       df_reorganize_refs_by_reg (&df->use_info, false, true, false);
1677       break;
1678 
1679     case DF_REF_ORDER_BY_REG_WITH_NOTES:
1680       df_reorganize_refs_by_reg (&df->use_info, false, true, true);
1681       break;
1682 
1683     case DF_REF_ORDER_BY_INSN:
1684       df_reorganize_refs_by_insn (&df->use_info, false, true, false);
1685       break;
1686 
1687     case DF_REF_ORDER_BY_INSN_WITH_NOTES:
1688       df_reorganize_refs_by_insn (&df->use_info, false, true, true);
1689       break;
1690 
1691     case DF_REF_ORDER_NO_TABLE:
1692       free (df->use_info.refs);
1693       df->use_info.refs = NULL;
1694       df->use_info.refs_size = 0;
1695       break;
1696 
1697     case DF_REF_ORDER_UNORDERED:
1698     case DF_REF_ORDER_UNORDERED_WITH_NOTES:
1699       gcc_unreachable ();
1700       break;
1701     }
1702 
1703   df->use_info.ref_order = order;
1704 }
1705 
1706 
1707 /* If the def refs in DF are not organized, reorganize them.  */
1708 
1709 void
1710 df_maybe_reorganize_def_refs (enum df_ref_order order)
1711 {
1712   if (order == df->def_info.ref_order)
1713     return;
1714 
1715   switch (order)
1716     {
1717     case DF_REF_ORDER_BY_REG:
1718       df_reorganize_refs_by_reg (&df->def_info, true, false, false);
1719       break;
1720 
1721     case DF_REF_ORDER_BY_INSN:
1722       df_reorganize_refs_by_insn (&df->def_info, true, false, false);
1723       break;
1724 
1725     case DF_REF_ORDER_NO_TABLE:
1726       free (df->def_info.refs);
1727       df->def_info.refs = NULL;
1728       df->def_info.refs_size = 0;
1729       break;
1730 
1731     case DF_REF_ORDER_BY_INSN_WITH_NOTES:
1732     case DF_REF_ORDER_BY_REG_WITH_NOTES:
1733     case DF_REF_ORDER_UNORDERED:
1734     case DF_REF_ORDER_UNORDERED_WITH_NOTES:
1735       gcc_unreachable ();
1736       break;
1737     }
1738 
1739   df->def_info.ref_order = order;
1740 }
1741 
1742 
1743 /* Change all of the basic block references in INSN to use the insn's
1744    current basic block.  This function is called from routines that move
1745    instructions from one block to another.  */
1746 
1747 void
1748 df_insn_change_bb (rtx_insn *insn, basic_block new_bb)
1749 {
1750   basic_block old_bb = BLOCK_FOR_INSN (insn);
1751   struct df_insn_info *insn_info;
1752   unsigned int uid = INSN_UID (insn);
1753 
1754   if (old_bb == new_bb)
1755     return;
1756 
1757   set_block_for_insn (insn, new_bb);
1758 
1759   if (!df)
1760     return;
1761 
1762   if (dump_file)
1763     fprintf (dump_file, "changing bb of uid %d\n", uid);
1764 
1765   insn_info = DF_INSN_UID_SAFE_GET (uid);
1766   if (insn_info == NULL)
1767     {
1768       if (dump_file)
1769 	fprintf (dump_file, "  unscanned insn\n");
1770       df_insn_rescan (insn);
1771       return;
1772     }
1773 
1774   if (!INSN_P (insn))
1775     return;
1776 
1777   df_set_bb_dirty (new_bb);
1778   if (old_bb)
1779     {
1780       if (dump_file)
1781 	fprintf (dump_file, "  from %d to %d\n",
1782 		 old_bb->index, new_bb->index);
1783       df_set_bb_dirty (old_bb);
1784     }
1785   else
1786     if (dump_file)
1787       fprintf (dump_file, "  to %d\n", new_bb->index);
1788 }
1789 
1790 
1791 /* Helper function for df_ref_change_reg_with_loc.  */
1792 
1793 static void
1794 df_ref_change_reg_with_loc_1 (struct df_reg_info *old_df,
1795 			      struct df_reg_info *new_df,
1796 			      unsigned int new_regno, rtx loc)
1797 {
1798   df_ref the_ref = old_df->reg_chain;
1799 
1800   while (the_ref)
1801     {
1802       if ((!DF_REF_IS_ARTIFICIAL (the_ref))
1803 	  && DF_REF_LOC (the_ref)
1804 	  && (*DF_REF_LOC (the_ref) == loc))
1805 	{
1806 	  df_ref next_ref = DF_REF_NEXT_REG (the_ref);
1807 	  df_ref prev_ref = DF_REF_PREV_REG (the_ref);
1808 	  df_ref *ref_ptr;
1809 	  struct df_insn_info *insn_info = DF_REF_INSN_INFO (the_ref);
1810 
1811 	  DF_REF_REGNO (the_ref) = new_regno;
1812 	  DF_REF_REG (the_ref) = regno_reg_rtx[new_regno];
1813 
1814 	  /* Pull the_ref out of the old regno chain.  */
1815 	  if (prev_ref)
1816 	    DF_REF_NEXT_REG (prev_ref) = next_ref;
1817 	  else
1818 	    old_df->reg_chain = next_ref;
1819 	  if (next_ref)
1820 	    DF_REF_PREV_REG (next_ref) = prev_ref;
1821 	  old_df->n_refs--;
1822 
1823 	  /* Put the ref into the new regno chain.  */
1824 	  DF_REF_PREV_REG (the_ref) = NULL;
1825 	  DF_REF_NEXT_REG (the_ref) = new_df->reg_chain;
1826 	  if (new_df->reg_chain)
1827 	    DF_REF_PREV_REG (new_df->reg_chain) = the_ref;
1828 	  new_df->reg_chain = the_ref;
1829 	  new_df->n_refs++;
1830 	  if (DF_REF_BB (the_ref))
1831 	    df_set_bb_dirty (DF_REF_BB (the_ref));
1832 
1833 	  /* Need to sort the record again that the ref was in because
1834 	     the regno is a sorting key.  First, find the right
1835 	     record.  */
1836 	  if (DF_REF_REG_DEF_P (the_ref))
1837 	    ref_ptr = &insn_info->defs;
1838 	  else if (DF_REF_FLAGS (the_ref) & DF_REF_IN_NOTE)
1839 	    ref_ptr = &insn_info->eq_uses;
1840 	  else
1841 	    ref_ptr = &insn_info->uses;
1842 	  if (dump_file)
1843 	    fprintf (dump_file, "changing reg in insn %d\n",
1844 		     DF_REF_INSN_UID (the_ref));
1845 
1846 	  /* Stop if we find the current reference or where the reference
1847 	     needs to be.  */
1848 	  while (*ref_ptr != the_ref && df_ref_compare (*ref_ptr, the_ref) < 0)
1849 	    ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
1850 	  if (*ref_ptr != the_ref)
1851 	    {
1852 	      /* The reference needs to be promoted up the list.  */
1853 	      df_ref next = DF_REF_NEXT_LOC (the_ref);
1854 	      DF_REF_NEXT_LOC (the_ref) = *ref_ptr;
1855 	      *ref_ptr = the_ref;
1856 	      do
1857 		ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
1858 	      while (*ref_ptr != the_ref);
1859 	      *ref_ptr = next;
1860 	    }
1861 	  else if (DF_REF_NEXT_LOC (the_ref)
1862 		   && df_ref_compare (the_ref, DF_REF_NEXT_LOC (the_ref)) > 0)
1863 	    {
1864 	      /* The reference needs to be demoted down the list.  */
1865 	      *ref_ptr = DF_REF_NEXT_LOC (the_ref);
1866 	      do
1867 		ref_ptr = &DF_REF_NEXT_LOC (*ref_ptr);
1868 	      while (*ref_ptr && df_ref_compare (the_ref, *ref_ptr) > 0);
1869 	      DF_REF_NEXT_LOC (the_ref) = *ref_ptr;
1870 	      *ref_ptr = the_ref;
1871 	    }
1872 
1873 	  the_ref = next_ref;
1874 	}
1875       else
1876 	the_ref = DF_REF_NEXT_REG (the_ref);
1877     }
1878 }
1879 
1880 
1881 /* Change the regno of register LOC to NEW_REGNO and update the df
1882    information accordingly.  Refs that do not match LOC are not changed
1883    which means that artificial refs are not changed since they have no loc.
1884    This call is to support the SET_REGNO macro. */
1885 
1886 void
1887 df_ref_change_reg_with_loc (rtx loc, unsigned int new_regno)
1888 {
1889   unsigned int old_regno = REGNO (loc);
1890   if (old_regno == new_regno)
1891     return;
1892 
1893   if (df)
1894     {
1895       df_grow_reg_info ();
1896 
1897       df_ref_change_reg_with_loc_1 (DF_REG_DEF_GET (old_regno),
1898 				    DF_REG_DEF_GET (new_regno),
1899 				    new_regno, loc);
1900       df_ref_change_reg_with_loc_1 (DF_REG_USE_GET (old_regno),
1901 				    DF_REG_USE_GET (new_regno),
1902 				    new_regno, loc);
1903       df_ref_change_reg_with_loc_1 (DF_REG_EQ_USE_GET (old_regno),
1904 				    DF_REG_EQ_USE_GET (new_regno),
1905 				    new_regno, loc);
1906     }
1907   set_mode_and_regno (loc, GET_MODE (loc), new_regno);
1908 }
1909 
1910 
1911 /* Delete the mw_hardregs that point into the eq_notes.  */
1912 
1913 static void
1914 df_mw_hardreg_chain_delete_eq_uses (struct df_insn_info *insn_info)
1915 {
1916   struct df_mw_hardreg **mw_ptr = &insn_info->mw_hardregs;
1917   struct df_scan_problem_data *problem_data
1918     = (struct df_scan_problem_data *) df_scan->problem_data;
1919 
1920   while (*mw_ptr)
1921     {
1922       df_mw_hardreg *mw = *mw_ptr;
1923       if (mw->flags & DF_REF_IN_NOTE)
1924 	{
1925 	  *mw_ptr = DF_MWS_NEXT (mw);
1926 	  problem_data->mw_reg_pool->remove (mw);
1927 	}
1928       else
1929 	mw_ptr = &DF_MWS_NEXT (mw);
1930     }
1931 }
1932 
1933 
1934 /* Rescan only the REG_EQUIV/REG_EQUAL notes part of INSN.  */
1935 
1936 void
1937 df_notes_rescan (rtx_insn *insn)
1938 {
1939   struct df_insn_info *insn_info;
1940   unsigned int uid = INSN_UID (insn);
1941 
1942   if (!df)
1943     return;
1944 
1945   /* The client has disabled rescanning and plans to do it itself.  */
1946   if (df->changeable_flags & DF_NO_INSN_RESCAN)
1947     return;
1948 
1949   /* Do nothing if the insn hasn't been emitted yet.  */
1950   if (!BLOCK_FOR_INSN (insn))
1951     return;
1952 
1953   df_grow_bb_info (df_scan);
1954   df_grow_reg_info ();
1955 
1956   insn_info = DF_INSN_UID_SAFE_GET (INSN_UID (insn));
1957 
1958   /* The client has deferred rescanning.  */
1959   if (df->changeable_flags & DF_DEFER_INSN_RESCAN)
1960     {
1961       if (!insn_info)
1962 	{
1963 	  insn_info = df_insn_create_insn_record (insn);
1964 	  insn_info->defs = 0;
1965 	  insn_info->uses = 0;
1966 	  insn_info->eq_uses = 0;
1967 	  insn_info->mw_hardregs = 0;
1968 	}
1969 
1970       bitmap_clear_bit (&df->insns_to_delete, uid);
1971       /* If the insn is set to be rescanned, it does not need to also
1972 	 be notes rescanned.  */
1973       if (!bitmap_bit_p (&df->insns_to_rescan, uid))
1974 	bitmap_set_bit (&df->insns_to_notes_rescan, INSN_UID (insn));
1975       return;
1976     }
1977 
1978   bitmap_clear_bit (&df->insns_to_delete, uid);
1979   bitmap_clear_bit (&df->insns_to_notes_rescan, uid);
1980 
1981   if (insn_info)
1982     {
1983       basic_block bb = BLOCK_FOR_INSN (insn);
1984       rtx note;
1985       struct df_collection_rec collection_rec;
1986       unsigned int i;
1987 
1988       df_mw_hardreg_chain_delete_eq_uses (insn_info);
1989       df_ref_chain_delete (insn_info->eq_uses);
1990       insn_info->eq_uses = NULL;
1991 
1992       /* Process REG_EQUIV/REG_EQUAL notes */
1993       for (note = REG_NOTES (insn); note;
1994 	   note = XEXP (note, 1))
1995 	{
1996 	  switch (REG_NOTE_KIND (note))
1997 	    {
1998 	    case REG_EQUIV:
1999 	    case REG_EQUAL:
2000 	      df_uses_record (&collection_rec,
2001 			      &XEXP (note, 0), DF_REF_REG_USE,
2002 			      bb, insn_info, DF_REF_IN_NOTE);
2003 	    default:
2004 	      break;
2005 	    }
2006 	}
2007 
2008       /* Find some place to put any new mw_hardregs.  */
2009       df_canonize_collection_rec (&collection_rec);
2010       struct df_mw_hardreg **mw_ptr = &insn_info->mw_hardregs, *mw;
2011       FOR_EACH_VEC_ELT (collection_rec.mw_vec, i, mw)
2012 	{
2013 	  while (*mw_ptr && df_mw_compare (*mw_ptr, mw) < 0)
2014 	    mw_ptr = &DF_MWS_NEXT (*mw_ptr);
2015 	  DF_MWS_NEXT (mw) = *mw_ptr;
2016 	  *mw_ptr = mw;
2017 	  mw_ptr = &DF_MWS_NEXT (mw);
2018 	}
2019       df_refs_add_to_chains (&collection_rec, bb, insn, copy_eq_uses);
2020     }
2021   else
2022     df_insn_rescan (insn);
2023 
2024 }
2025 
2026 
2027 /*----------------------------------------------------------------------------
2028    Hard core instruction scanning code.  No external interfaces here,
2029    just a lot of routines that look inside insns.
2030 ----------------------------------------------------------------------------*/
2031 
2032 
2033 /* Return true if the contents of two df_ref's are identical.
2034    It ignores DF_REF_MARKER.  */
2035 
2036 static bool
2037 df_ref_equal_p (df_ref ref1, df_ref ref2)
2038 {
2039   if (!ref2)
2040     return false;
2041 
2042   if (ref1 == ref2)
2043     return true;
2044 
2045   if (DF_REF_CLASS (ref1) != DF_REF_CLASS (ref2)
2046       || DF_REF_REGNO (ref1) != DF_REF_REGNO (ref2)
2047       || DF_REF_REG (ref1) != DF_REF_REG (ref2)
2048       || DF_REF_TYPE (ref1) != DF_REF_TYPE (ref2)
2049       || ((DF_REF_FLAGS (ref1) & ~(DF_REF_REG_MARKER + DF_REF_MW_HARDREG))
2050 	  != (DF_REF_FLAGS (ref2) & ~(DF_REF_REG_MARKER + DF_REF_MW_HARDREG)))
2051       || DF_REF_BB (ref1) != DF_REF_BB (ref2)
2052       || DF_REF_INSN_INFO (ref1) != DF_REF_INSN_INFO (ref2))
2053     return false;
2054 
2055   switch (DF_REF_CLASS (ref1))
2056     {
2057     case DF_REF_ARTIFICIAL:
2058     case DF_REF_BASE:
2059       return true;
2060 
2061     case DF_REF_REGULAR:
2062       return DF_REF_LOC (ref1) == DF_REF_LOC (ref2);
2063 
2064     default:
2065       gcc_unreachable ();
2066     }
2067   return false;
2068 }
2069 
2070 
2071 /* Compare REF1 and REF2 for sorting.  This is only called from places
2072    where all of the refs are of the same type, in the same insn, and
2073    have the same bb.  So these fields are not checked.  */
2074 
2075 static int
2076 df_ref_compare (df_ref ref1, df_ref ref2)
2077 {
2078   if (DF_REF_CLASS (ref1) != DF_REF_CLASS (ref2))
2079     return (int)DF_REF_CLASS (ref1) - (int)DF_REF_CLASS (ref2);
2080 
2081   if (DF_REF_REGNO (ref1) != DF_REF_REGNO (ref2))
2082     return (int)DF_REF_REGNO (ref1) - (int)DF_REF_REGNO (ref2);
2083 
2084   if (DF_REF_TYPE (ref1) != DF_REF_TYPE (ref2))
2085     return (int)DF_REF_TYPE (ref1) - (int)DF_REF_TYPE (ref2);
2086 
2087   if (DF_REF_REG (ref1) != DF_REF_REG (ref2))
2088     return (int)DF_REF_ORDER (ref1) - (int)DF_REF_ORDER (ref2);
2089 
2090   /* Cannot look at the LOC field on artificial refs.  */
2091   if (DF_REF_CLASS (ref1) != DF_REF_ARTIFICIAL
2092       && DF_REF_LOC (ref1) != DF_REF_LOC (ref2))
2093     return (int)DF_REF_ORDER (ref1) - (int)DF_REF_ORDER (ref2);
2094 
2095   if (DF_REF_FLAGS (ref1) != DF_REF_FLAGS (ref2))
2096     {
2097       /* If two refs are identical except that one of them has is from
2098 	 a mw and one is not, we need to have the one with the mw
2099 	 first.  */
2100       if (DF_REF_FLAGS_IS_SET (ref1, DF_REF_MW_HARDREG) ==
2101 	  DF_REF_FLAGS_IS_SET (ref2, DF_REF_MW_HARDREG))
2102 	return DF_REF_FLAGS (ref1) - DF_REF_FLAGS (ref2);
2103       else if (DF_REF_FLAGS_IS_SET (ref1, DF_REF_MW_HARDREG))
2104 	return -1;
2105       else
2106 	return 1;
2107     }
2108 
2109   return (int)DF_REF_ORDER (ref1) - (int)DF_REF_ORDER (ref2);
2110 }
2111 
2112 /* Like df_ref_compare, but compare two df_ref* pointers R1 and R2.  */
2113 
2114 static int
2115 df_ref_ptr_compare (const void *r1, const void *r2)
2116 {
2117   return df_ref_compare (*(const df_ref *) r1, *(const df_ref *) r2);
2118 }
2119 
2120 /* Sort and compress a set of refs.  */
2121 
2122 static void
2123 df_sort_and_compress_refs (vec<df_ref, va_heap> *ref_vec)
2124 {
2125   unsigned int count;
2126   unsigned int i;
2127   unsigned int dist = 0;
2128 
2129   count = ref_vec->length ();
2130 
2131   /* If there are 1 or 0 elements, there is nothing to do.  */
2132   if (count < 2)
2133     return;
2134   else if (count == 2)
2135     {
2136       df_ref r0 = (*ref_vec)[0];
2137       df_ref r1 = (*ref_vec)[1];
2138       if (df_ref_compare (r0, r1) > 0)
2139 	std::swap ((*ref_vec)[0], (*ref_vec)[1]);
2140     }
2141   else
2142     {
2143       for (i = 0; i < count - 1; i++)
2144 	{
2145 	  df_ref r0 = (*ref_vec)[i];
2146 	  df_ref r1 = (*ref_vec)[i + 1];
2147 	  if (df_ref_compare (r0, r1) >= 0)
2148 	    break;
2149 	}
2150       /* If the array is already strictly ordered,
2151          which is the most common case for large COUNT case
2152          (which happens for CALL INSNs),
2153          no need to sort and filter out duplicate.
2154          Simply return the count.
2155          Make sure DF_GET_ADD_REFS adds refs in the increasing order
2156          of DF_REF_COMPARE.  */
2157       if (i == count - 1)
2158         return;
2159       ref_vec->qsort (df_ref_ptr_compare);
2160     }
2161 
2162   for (i=0; i<count-dist; i++)
2163     {
2164       /* Find the next ref that is not equal to the current ref.  */
2165       while (i + dist + 1 < count
2166 	     && df_ref_equal_p ((*ref_vec)[i],
2167 				(*ref_vec)[i + dist + 1]))
2168 	{
2169 	  df_free_ref ((*ref_vec)[i + dist + 1]);
2170 	  dist++;
2171 	}
2172       /* Copy it down to the next position.  */
2173       if (dist && i + dist + 1 < count)
2174 	(*ref_vec)[i + 1] = (*ref_vec)[i + dist + 1];
2175     }
2176 
2177   count -= dist;
2178   ref_vec->truncate (count);
2179 }
2180 
2181 
2182 /* Return true if the contents of two df_ref's are identical.
2183    It ignores DF_REF_MARKER.  */
2184 
2185 static bool
2186 df_mw_equal_p (struct df_mw_hardreg *mw1, struct df_mw_hardreg *mw2)
2187 {
2188   if (!mw2)
2189     return false;
2190   return (mw1 == mw2) ||
2191     (mw1->mw_reg == mw2->mw_reg
2192      && mw1->type == mw2->type
2193      && mw1->flags == mw2->flags
2194      && mw1->start_regno == mw2->start_regno
2195      && mw1->end_regno == mw2->end_regno);
2196 }
2197 
2198 
2199 /* Compare MW1 and MW2 for sorting.  */
2200 
2201 static int
2202 df_mw_compare (const df_mw_hardreg *mw1, const df_mw_hardreg *mw2)
2203 {
2204   if (mw1->type != mw2->type)
2205     return mw1->type - mw2->type;
2206 
2207   if (mw1->flags != mw2->flags)
2208     return mw1->flags - mw2->flags;
2209 
2210   if (mw1->start_regno != mw2->start_regno)
2211     return mw1->start_regno - mw2->start_regno;
2212 
2213   if (mw1->end_regno != mw2->end_regno)
2214     return mw1->end_regno - mw2->end_regno;
2215 
2216   if (mw1->mw_reg != mw2->mw_reg)
2217     return mw1->mw_order - mw2->mw_order;
2218 
2219   return 0;
2220 }
2221 
2222 /* Like df_mw_compare, but compare two df_mw_hardreg** pointers R1 and R2.  */
2223 
2224 static int
2225 df_mw_ptr_compare (const void *m1, const void *m2)
2226 {
2227   return df_mw_compare (*(const df_mw_hardreg *const *) m1,
2228 			*(const df_mw_hardreg *const *) m2);
2229 }
2230 
2231 /* Sort and compress a set of refs.  */
2232 
2233 static void
2234 df_sort_and_compress_mws (vec<df_mw_hardreg *, va_heap> *mw_vec)
2235 {
2236   unsigned int count;
2237   struct df_scan_problem_data *problem_data
2238     = (struct df_scan_problem_data *) df_scan->problem_data;
2239   unsigned int i;
2240   unsigned int dist = 0;
2241 
2242   count = mw_vec->length ();
2243   if (count < 2)
2244     return;
2245   else if (count == 2)
2246     {
2247       struct df_mw_hardreg *m0 = (*mw_vec)[0];
2248       struct df_mw_hardreg *m1 = (*mw_vec)[1];
2249       if (df_mw_compare (m0, m1) > 0)
2250         {
2251           struct df_mw_hardreg *tmp = (*mw_vec)[0];
2252 	  (*mw_vec)[0] = (*mw_vec)[1];
2253 	  (*mw_vec)[1] = tmp;
2254         }
2255     }
2256   else
2257     mw_vec->qsort (df_mw_ptr_compare);
2258 
2259   for (i=0; i<count-dist; i++)
2260     {
2261       /* Find the next ref that is not equal to the current ref.  */
2262       while (i + dist + 1 < count
2263 	     && df_mw_equal_p ((*mw_vec)[i], (*mw_vec)[i + dist + 1]))
2264 	{
2265 	  problem_data->mw_reg_pool->remove ((*mw_vec)[i + dist + 1]);
2266 	  dist++;
2267 	}
2268       /* Copy it down to the next position.  */
2269       if (dist && i + dist + 1 < count)
2270 	(*mw_vec)[i + 1] = (*mw_vec)[i + dist + 1];
2271     }
2272 
2273   count -= dist;
2274   mw_vec->truncate (count);
2275 }
2276 
2277 
2278 /* Sort and remove duplicates from the COLLECTION_REC.  */
2279 
2280 static void
2281 df_canonize_collection_rec (struct df_collection_rec *collection_rec)
2282 {
2283   df_sort_and_compress_refs (&collection_rec->def_vec);
2284   df_sort_and_compress_refs (&collection_rec->use_vec);
2285   df_sort_and_compress_refs (&collection_rec->eq_use_vec);
2286   df_sort_and_compress_mws (&collection_rec->mw_vec);
2287 }
2288 
2289 
2290 /* Add the new df_ref to appropriate reg_info/ref_info chains.  */
2291 
2292 static void
2293 df_install_ref (df_ref this_ref,
2294 		struct df_reg_info *reg_info,
2295 		struct df_ref_info *ref_info,
2296 		bool add_to_table)
2297 {
2298   unsigned int regno = DF_REF_REGNO (this_ref);
2299   /* Add the ref to the reg_{def,use,eq_use} chain.  */
2300   df_ref head = reg_info->reg_chain;
2301 
2302   reg_info->reg_chain = this_ref;
2303   reg_info->n_refs++;
2304 
2305   if (DF_REF_FLAGS_IS_SET (this_ref, DF_HARD_REG_LIVE))
2306     {
2307       gcc_assert (regno < FIRST_PSEUDO_REGISTER);
2308       df->hard_regs_live_count[regno]++;
2309     }
2310 
2311   gcc_checking_assert (DF_REF_NEXT_REG (this_ref) == NULL
2312 		       && DF_REF_PREV_REG (this_ref) == NULL);
2313 
2314   DF_REF_NEXT_REG (this_ref) = head;
2315 
2316   /* We cannot actually link to the head of the chain.  */
2317   DF_REF_PREV_REG (this_ref) = NULL;
2318 
2319   if (head)
2320     DF_REF_PREV_REG (head) = this_ref;
2321 
2322   if (add_to_table)
2323     {
2324       gcc_assert (ref_info->ref_order != DF_REF_ORDER_NO_TABLE);
2325       df_check_and_grow_ref_info (ref_info, 1);
2326       DF_REF_ID (this_ref) = ref_info->table_size;
2327       /* Add the ref to the big array of defs.  */
2328       ref_info->refs[ref_info->table_size] = this_ref;
2329       ref_info->table_size++;
2330     }
2331   else
2332     DF_REF_ID (this_ref) = -1;
2333 
2334   ref_info->total_size++;
2335 }
2336 
2337 
2338 /* This function takes one of the groups of refs (defs, uses or
2339    eq_uses) and installs the entire group into the insn.  It also adds
2340    each of these refs into the appropriate chains.  */
2341 
2342 static df_ref
2343 df_install_refs (basic_block bb,
2344 		 const vec<df_ref, va_heap> *old_vec,
2345 		 struct df_reg_info **reg_info,
2346 		 struct df_ref_info *ref_info,
2347 		 bool is_notes)
2348 {
2349   unsigned int count = old_vec->length ();
2350   if (count)
2351     {
2352       bool add_to_table;
2353       df_ref this_ref;
2354       unsigned int ix;
2355 
2356       switch (ref_info->ref_order)
2357 	{
2358 	case DF_REF_ORDER_UNORDERED_WITH_NOTES:
2359 	case DF_REF_ORDER_BY_REG_WITH_NOTES:
2360 	case DF_REF_ORDER_BY_INSN_WITH_NOTES:
2361 	  ref_info->ref_order = DF_REF_ORDER_UNORDERED_WITH_NOTES;
2362 	  add_to_table = true;
2363 	  break;
2364 	case DF_REF_ORDER_UNORDERED:
2365 	case DF_REF_ORDER_BY_REG:
2366 	case DF_REF_ORDER_BY_INSN:
2367 	  ref_info->ref_order = DF_REF_ORDER_UNORDERED;
2368 	  add_to_table = !is_notes;
2369 	  break;
2370 	default:
2371 	  add_to_table = false;
2372 	  break;
2373 	}
2374 
2375       /* Do not add if ref is not in the right blocks.  */
2376       if (add_to_table && df->analyze_subset)
2377 	add_to_table = bitmap_bit_p (df->blocks_to_analyze, bb->index);
2378 
2379       FOR_EACH_VEC_ELT (*old_vec, ix, this_ref)
2380 	{
2381 	  DF_REF_NEXT_LOC (this_ref) = (ix + 1 < old_vec->length ()
2382 					? (*old_vec)[ix + 1]
2383 					: NULL);
2384 	  df_install_ref (this_ref, reg_info[DF_REF_REGNO (this_ref)],
2385 			  ref_info, add_to_table);
2386 	}
2387       return (*old_vec)[0];
2388     }
2389   else
2390     return 0;
2391 }
2392 
2393 
2394 /* This function takes the mws installs the entire group into the
2395    insn.  */
2396 
2397 static struct df_mw_hardreg *
2398 df_install_mws (const vec<df_mw_hardreg *, va_heap> *old_vec)
2399 {
2400   unsigned int count = old_vec->length ();
2401   if (count)
2402     {
2403       for (unsigned int i = 0; i < count - 1; i++)
2404 	DF_MWS_NEXT ((*old_vec)[i]) = (*old_vec)[i + 1];
2405       DF_MWS_NEXT ((*old_vec)[count - 1]) = 0;
2406       return (*old_vec)[0];
2407     }
2408   else
2409     return 0;
2410 }
2411 
2412 
2413 /* Add a chain of df_refs to appropriate ref chain/reg_info/ref_info
2414    chains and update other necessary information.  */
2415 
2416 static void
2417 df_refs_add_to_chains (struct df_collection_rec *collection_rec,
2418 		       basic_block bb, rtx_insn *insn, unsigned int flags)
2419 {
2420   if (insn)
2421     {
2422       struct df_insn_info *insn_rec = DF_INSN_INFO_GET (insn);
2423       /* If there is a vector in the collection rec, add it to the
2424 	 insn.  A null rec is a signal that the caller will handle the
2425 	 chain specially.  */
2426       if (flags & copy_defs)
2427 	{
2428 	  gcc_checking_assert (!insn_rec->defs);
2429 	  insn_rec->defs
2430 	    = df_install_refs (bb, &collection_rec->def_vec,
2431 			       df->def_regs,
2432 			       &df->def_info, false);
2433 	}
2434       if (flags & copy_uses)
2435 	{
2436 	  gcc_checking_assert (!insn_rec->uses);
2437 	  insn_rec->uses
2438 	    = df_install_refs (bb, &collection_rec->use_vec,
2439 			       df->use_regs,
2440 			       &df->use_info, false);
2441 	}
2442       if (flags & copy_eq_uses)
2443 	{
2444 	  gcc_checking_assert (!insn_rec->eq_uses);
2445 	  insn_rec->eq_uses
2446 	    = df_install_refs (bb, &collection_rec->eq_use_vec,
2447 			       df->eq_use_regs,
2448 			       &df->use_info, true);
2449 	}
2450       if (flags & copy_mw)
2451 	{
2452 	  gcc_checking_assert (!insn_rec->mw_hardregs);
2453 	  insn_rec->mw_hardregs
2454 	    = df_install_mws (&collection_rec->mw_vec);
2455 	}
2456     }
2457   else
2458     {
2459       struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb->index);
2460 
2461       gcc_checking_assert (!bb_info->artificial_defs);
2462       bb_info->artificial_defs
2463 	= df_install_refs (bb, &collection_rec->def_vec,
2464 			   df->def_regs,
2465 			   &df->def_info, false);
2466       gcc_checking_assert (!bb_info->artificial_uses);
2467       bb_info->artificial_uses
2468 	= df_install_refs (bb, &collection_rec->use_vec,
2469 			   df->use_regs,
2470 			   &df->use_info, false);
2471     }
2472 }
2473 
2474 
2475 /* Allocate a ref and initialize its fields.  */
2476 
2477 static df_ref
2478 df_ref_create_structure (enum df_ref_class cl,
2479 			 struct df_collection_rec *collection_rec,
2480 			 rtx reg, rtx *loc,
2481 			 basic_block bb, struct df_insn_info *info,
2482 			 enum df_ref_type ref_type,
2483 			 int ref_flags)
2484 {
2485   df_ref this_ref = NULL;
2486   unsigned int regno = REGNO (GET_CODE (reg) == SUBREG ? SUBREG_REG (reg) : reg);
2487   struct df_scan_problem_data *problem_data
2488     = (struct df_scan_problem_data *) df_scan->problem_data;
2489 
2490   switch (cl)
2491     {
2492     case DF_REF_BASE:
2493       this_ref = (df_ref) (problem_data->ref_base_pool->allocate ());
2494       gcc_checking_assert (loc == NULL);
2495       break;
2496 
2497     case DF_REF_ARTIFICIAL:
2498       this_ref = (df_ref) (problem_data->ref_artificial_pool->allocate ());
2499       this_ref->artificial_ref.bb = bb;
2500       gcc_checking_assert (loc == NULL);
2501       break;
2502 
2503     case DF_REF_REGULAR:
2504       this_ref = (df_ref) (problem_data->ref_regular_pool->allocate ());
2505       this_ref->regular_ref.loc = loc;
2506       gcc_checking_assert (loc);
2507       break;
2508     }
2509 
2510   DF_REF_CLASS (this_ref) = cl;
2511   DF_REF_ID (this_ref) = -1;
2512   DF_REF_REG (this_ref) = reg;
2513   DF_REF_REGNO (this_ref) =  regno;
2514   DF_REF_TYPE (this_ref) = ref_type;
2515   DF_REF_INSN_INFO (this_ref) = info;
2516   DF_REF_CHAIN (this_ref) = NULL;
2517   DF_REF_FLAGS (this_ref) = ref_flags;
2518   DF_REF_NEXT_REG (this_ref) = NULL;
2519   DF_REF_PREV_REG (this_ref) = NULL;
2520   DF_REF_ORDER (this_ref) = df->ref_order++;
2521 
2522   /* We need to clear this bit because fwprop, and in the future
2523      possibly other optimizations sometimes create new refs using ond
2524      refs as the model.  */
2525   DF_REF_FLAGS_CLEAR (this_ref, DF_HARD_REG_LIVE);
2526 
2527   /* See if this ref needs to have DF_HARD_REG_LIVE bit set.  */
2528   if (regno < FIRST_PSEUDO_REGISTER
2529       && !DF_REF_IS_ARTIFICIAL (this_ref)
2530       && !DEBUG_INSN_P (DF_REF_INSN (this_ref)))
2531     {
2532       if (DF_REF_REG_DEF_P (this_ref))
2533 	{
2534 	  if (!DF_REF_FLAGS_IS_SET (this_ref, DF_REF_MAY_CLOBBER))
2535 	    DF_REF_FLAGS_SET (this_ref, DF_HARD_REG_LIVE);
2536 	}
2537       else if (!(TEST_HARD_REG_BIT (elim_reg_set, regno)
2538 		 && (regno == FRAME_POINTER_REGNUM
2539 		     || regno == ARG_POINTER_REGNUM)))
2540 	DF_REF_FLAGS_SET (this_ref, DF_HARD_REG_LIVE);
2541     }
2542 
2543   if (collection_rec)
2544     {
2545       if (DF_REF_REG_DEF_P (this_ref))
2546 	collection_rec->def_vec.safe_push (this_ref);
2547       else if (DF_REF_FLAGS (this_ref) & DF_REF_IN_NOTE)
2548 	collection_rec->eq_use_vec.safe_push (this_ref);
2549       else
2550 	collection_rec->use_vec.safe_push (this_ref);
2551     }
2552   else
2553     df_install_ref_incremental (this_ref);
2554 
2555   return this_ref;
2556 }
2557 
2558 
2559 /* Create new references of type DF_REF_TYPE for each part of register REG
2560    at address LOC within INSN of BB.  */
2561 
2562 
2563 static void
2564 df_ref_record (enum df_ref_class cl,
2565 	       struct df_collection_rec *collection_rec,
2566                rtx reg, rtx *loc,
2567 	       basic_block bb, struct df_insn_info *insn_info,
2568 	       enum df_ref_type ref_type,
2569 	       int ref_flags)
2570 {
2571   unsigned int regno;
2572 
2573   gcc_checking_assert (REG_P (reg) || GET_CODE (reg) == SUBREG);
2574 
2575   regno = REGNO (GET_CODE (reg) == SUBREG ? SUBREG_REG (reg) : reg);
2576   if (regno < FIRST_PSEUDO_REGISTER)
2577     {
2578       struct df_mw_hardreg *hardreg = NULL;
2579       struct df_scan_problem_data *problem_data
2580         = (struct df_scan_problem_data *) df_scan->problem_data;
2581       unsigned int i;
2582       unsigned int endregno;
2583       df_ref ref;
2584 
2585       if (GET_CODE (reg) == SUBREG)
2586 	{
2587 	  regno += subreg_regno_offset (regno, GET_MODE (SUBREG_REG (reg)),
2588 					SUBREG_BYTE (reg), GET_MODE (reg));
2589 	  endregno = regno + subreg_nregs (reg);
2590 	}
2591       else
2592 	endregno = END_REGNO (reg);
2593 
2594       /*  If this is a multiword hardreg, we create some extra
2595 	  datastructures that will enable us to easily build REG_DEAD
2596 	  and REG_UNUSED notes.  */
2597       if (collection_rec
2598 	  && (endregno != regno + 1) && insn_info)
2599 	{
2600 	  /* Sets to a subreg of a multiword register are partial.
2601 	     Sets to a non-subreg of a multiword register are not.  */
2602 	  if (GET_CODE (reg) == SUBREG)
2603 	    ref_flags |= DF_REF_PARTIAL;
2604 	  ref_flags |= DF_REF_MW_HARDREG;
2605 
2606 	  hardreg = problem_data->mw_reg_pool->allocate ();
2607 	  hardreg->type = ref_type;
2608 	  hardreg->flags = ref_flags;
2609 	  hardreg->mw_reg = reg;
2610 	  hardreg->start_regno = regno;
2611 	  hardreg->end_regno = endregno - 1;
2612 	  hardreg->mw_order = df->ref_order++;
2613 	  collection_rec->mw_vec.safe_push (hardreg);
2614 	}
2615 
2616       for (i = regno; i < endregno; i++)
2617 	{
2618 	  ref = df_ref_create_structure (cl, collection_rec, regno_reg_rtx[i], loc,
2619 					 bb, insn_info, ref_type, ref_flags);
2620 
2621           gcc_assert (ORIGINAL_REGNO (DF_REF_REG (ref)) == i);
2622 	}
2623     }
2624   else
2625     {
2626       df_ref_create_structure (cl, collection_rec, reg, loc, bb, insn_info,
2627 			       ref_type, ref_flags);
2628     }
2629 }
2630 
2631 
2632 /* A set to a non-paradoxical SUBREG for which the number of word_mode units
2633    covered by the outer mode is smaller than that covered by the inner mode,
2634    is a read-modify-write operation.
2635    This function returns true iff the SUBREG X is such a SUBREG.  */
2636 
2637 bool
2638 df_read_modify_subreg_p (rtx x)
2639 {
2640   unsigned int isize, osize;
2641   if (GET_CODE (x) != SUBREG)
2642     return false;
2643   isize = GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)));
2644   osize = GET_MODE_SIZE (GET_MODE (x));
2645   return isize > osize
2646 	 && isize > REGMODE_NATURAL_SIZE (GET_MODE (SUBREG_REG (x)));
2647 }
2648 
2649 
2650 /* Process all the registers defined in the rtx pointed by LOC.
2651    Autoincrement/decrement definitions will be picked up by df_uses_record.
2652    Any change here has to be matched in df_find_hard_reg_defs_1.  */
2653 
2654 static void
2655 df_def_record_1 (struct df_collection_rec *collection_rec,
2656                  rtx *loc, basic_block bb, struct df_insn_info *insn_info,
2657 		 int flags)
2658 {
2659   rtx dst = *loc;
2660 
2661   /* It is legal to have a set destination be a parallel. */
2662   if (GET_CODE (dst) == PARALLEL)
2663     {
2664       int i;
2665       for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
2666 	{
2667 	  rtx temp = XVECEXP (dst, 0, i);
2668 	  gcc_assert (GET_CODE (temp) == EXPR_LIST);
2669 	  df_def_record_1 (collection_rec, &XEXP (temp, 0),
2670 			   bb, insn_info, flags);
2671 	}
2672       return;
2673     }
2674 
2675   if (GET_CODE (dst) == STRICT_LOW_PART)
2676     {
2677       flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL | DF_REF_STRICT_LOW_PART;
2678 
2679       loc = &XEXP (dst, 0);
2680       dst = *loc;
2681     }
2682 
2683   if (GET_CODE (dst) == ZERO_EXTRACT)
2684     {
2685       flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL | DF_REF_ZERO_EXTRACT;
2686 
2687       loc = &XEXP (dst, 0);
2688       dst = *loc;
2689     }
2690 
2691   /* At this point if we do not have a reg or a subreg, just return.  */
2692   if (REG_P (dst))
2693     {
2694       df_ref_record (DF_REF_REGULAR, collection_rec,
2695 		     dst, loc, bb, insn_info, DF_REF_REG_DEF, flags);
2696 
2697       /* We want to keep sp alive everywhere - by making all
2698 	 writes to sp also use of sp. */
2699       if (REGNO (dst) == STACK_POINTER_REGNUM)
2700 	df_ref_record (DF_REF_BASE, collection_rec,
2701 		       dst, NULL, bb, insn_info, DF_REF_REG_USE, flags);
2702     }
2703   else if (GET_CODE (dst) == SUBREG && REG_P (SUBREG_REG (dst)))
2704     {
2705       if (df_read_modify_subreg_p (dst))
2706 	flags |= DF_REF_READ_WRITE | DF_REF_PARTIAL;
2707 
2708       flags |= DF_REF_SUBREG;
2709 
2710       df_ref_record (DF_REF_REGULAR, collection_rec,
2711 		     dst, loc, bb, insn_info, DF_REF_REG_DEF, flags);
2712     }
2713 }
2714 
2715 
2716 /* Process all the registers defined in the pattern rtx, X.  Any change
2717    here has to be matched in df_find_hard_reg_defs.  */
2718 
2719 static void
2720 df_defs_record (struct df_collection_rec *collection_rec,
2721                 rtx x, basic_block bb, struct df_insn_info *insn_info,
2722 		int flags)
2723 {
2724   RTX_CODE code = GET_CODE (x);
2725   int i;
2726 
2727   switch (code)
2728     {
2729     case SET:
2730       df_def_record_1 (collection_rec, &SET_DEST (x), bb, insn_info, flags);
2731       break;
2732 
2733     case CLOBBER:
2734       flags |= DF_REF_MUST_CLOBBER;
2735       df_def_record_1 (collection_rec, &XEXP (x, 0), bb, insn_info, flags);
2736       break;
2737 
2738     case COND_EXEC:
2739       df_defs_record (collection_rec, COND_EXEC_CODE (x),
2740 		      bb, insn_info, DF_REF_CONDITIONAL);
2741       break;
2742 
2743     case PARALLEL:
2744       for (i = 0; i < XVECLEN (x, 0); i++)
2745 	df_defs_record (collection_rec, XVECEXP (x, 0, i),
2746 			bb, insn_info, flags);
2747       break;
2748     default:
2749       /* No DEFs to record in other cases */
2750       break;
2751     }
2752 }
2753 
2754 /* Set bits in *DEFS for hard registers found in the rtx DST, which is the
2755    destination of a set or clobber.  This has to match the logic in
2756    df_defs_record_1.  */
2757 
2758 static void
2759 df_find_hard_reg_defs_1 (rtx dst, HARD_REG_SET *defs)
2760 {
2761   /* It is legal to have a set destination be a parallel. */
2762   if (GET_CODE (dst) == PARALLEL)
2763     {
2764       int i;
2765       for (i = XVECLEN (dst, 0) - 1; i >= 0; i--)
2766 	{
2767 	  rtx temp = XVECEXP (dst, 0, i);
2768 	  gcc_assert (GET_CODE (temp) == EXPR_LIST);
2769 	  df_find_hard_reg_defs_1 (XEXP (temp, 0), defs);
2770 	}
2771       return;
2772     }
2773 
2774   if (GET_CODE (dst) == STRICT_LOW_PART)
2775       dst = XEXP (dst, 0);
2776 
2777   if (GET_CODE (dst) == ZERO_EXTRACT)
2778       dst = XEXP (dst, 0);
2779 
2780   /* At this point if we do not have a reg or a subreg, just return.  */
2781   if (REG_P (dst) && HARD_REGISTER_P (dst))
2782     SET_HARD_REG_BIT (*defs, REGNO (dst));
2783   else if (GET_CODE (dst) == SUBREG
2784 	   && REG_P (SUBREG_REG (dst)) && HARD_REGISTER_P (dst))
2785     SET_HARD_REG_BIT (*defs, REGNO (SUBREG_REG (dst)));
2786 }
2787 
2788 /* Set bits in *DEFS for hard registers defined in the pattern X.  This
2789    has to match the logic in df_defs_record.  */
2790 
2791 static void
2792 df_find_hard_reg_defs (rtx x, HARD_REG_SET *defs)
2793 {
2794   RTX_CODE code = GET_CODE (x);
2795   int i;
2796 
2797   switch (code)
2798     {
2799     case SET:
2800       df_find_hard_reg_defs_1 (SET_DEST (x), defs);
2801       break;
2802 
2803     case CLOBBER:
2804       df_find_hard_reg_defs_1 (XEXP (x, 0), defs);
2805       break;
2806 
2807     case COND_EXEC:
2808       df_find_hard_reg_defs (COND_EXEC_CODE (x), defs);
2809       break;
2810 
2811     case PARALLEL:
2812       for (i = 0; i < XVECLEN (x, 0); i++)
2813 	df_find_hard_reg_defs (XVECEXP (x, 0, i), defs);
2814       break;
2815     default:
2816       /* No DEFs to record in other cases */
2817       break;
2818     }
2819 }
2820 
2821 
2822 /* Process all the registers used in the rtx at address LOC.  */
2823 
2824 static void
2825 df_uses_record (struct df_collection_rec *collection_rec,
2826                 rtx *loc, enum df_ref_type ref_type,
2827 		basic_block bb, struct df_insn_info *insn_info,
2828 		int flags)
2829 {
2830   RTX_CODE code;
2831   rtx x;
2832 
2833  retry:
2834   x = *loc;
2835   if (!x)
2836     return;
2837   code = GET_CODE (x);
2838   switch (code)
2839     {
2840     case LABEL_REF:
2841     case SYMBOL_REF:
2842     case CONST:
2843     CASE_CONST_ANY:
2844     case PC:
2845     case CC0:
2846     case ADDR_VEC:
2847     case ADDR_DIFF_VEC:
2848       return;
2849 
2850     case CLOBBER:
2851       /* If we are clobbering a MEM, mark any registers inside the address
2852 	 as being used.  */
2853       if (MEM_P (XEXP (x, 0)))
2854 	df_uses_record (collection_rec,
2855 			&XEXP (XEXP (x, 0), 0),
2856 			DF_REF_REG_MEM_STORE,
2857 		        bb, insn_info,
2858 			flags);
2859 
2860       /* If we're clobbering a REG then we have a def so ignore.  */
2861       return;
2862 
2863     case MEM:
2864       df_uses_record (collection_rec,
2865 		      &XEXP (x, 0), DF_REF_REG_MEM_LOAD,
2866 		      bb, insn_info, flags & DF_REF_IN_NOTE);
2867       return;
2868 
2869     case SUBREG:
2870       /* While we're here, optimize this case.  */
2871       flags |= DF_REF_PARTIAL;
2872       /* In case the SUBREG is not of a REG, do not optimize.  */
2873       if (!REG_P (SUBREG_REG (x)))
2874 	{
2875 	  loc = &SUBREG_REG (x);
2876 	  df_uses_record (collection_rec, loc, ref_type, bb, insn_info, flags);
2877 	  return;
2878 	}
2879       /* Fall through */
2880 
2881     case REG:
2882       df_ref_record (DF_REF_REGULAR, collection_rec,
2883 		     x, loc, bb, insn_info,
2884 		     ref_type, flags);
2885       return;
2886 
2887     case SIGN_EXTRACT:
2888     case ZERO_EXTRACT:
2889       {
2890         df_uses_record (collection_rec,
2891                         &XEXP (x, 1), ref_type, bb, insn_info, flags);
2892         df_uses_record (collection_rec,
2893                         &XEXP (x, 2), ref_type, bb, insn_info, flags);
2894 
2895         /* If the parameters to the zero or sign extract are
2896            constants, strip them off and recurse, otherwise there is
2897            no information that we can gain from this operation.  */
2898         if (code == ZERO_EXTRACT)
2899           flags |= DF_REF_ZERO_EXTRACT;
2900         else
2901           flags |= DF_REF_SIGN_EXTRACT;
2902 
2903         df_uses_record (collection_rec,
2904                         &XEXP (x, 0), ref_type, bb, insn_info, flags);
2905         return;
2906       }
2907       break;
2908 
2909     case SET:
2910       {
2911 	rtx dst = SET_DEST (x);
2912 	gcc_assert (!(flags & DF_REF_IN_NOTE));
2913 	df_uses_record (collection_rec,
2914 			&SET_SRC (x), DF_REF_REG_USE, bb, insn_info, flags);
2915 
2916 	switch (GET_CODE (dst))
2917 	  {
2918 	    case SUBREG:
2919 	      if (df_read_modify_subreg_p (dst))
2920 		{
2921 		  df_uses_record (collection_rec, &SUBREG_REG (dst),
2922 				  DF_REF_REG_USE, bb, insn_info,
2923 				  flags | DF_REF_READ_WRITE | DF_REF_SUBREG);
2924 		  break;
2925 		}
2926 	      /* Fall through.  */
2927 	    case REG:
2928 	    case PARALLEL:
2929 	    case SCRATCH:
2930 	    case PC:
2931 	    case CC0:
2932 		break;
2933 	    case MEM:
2934 	      df_uses_record (collection_rec, &XEXP (dst, 0),
2935 			      DF_REF_REG_MEM_STORE, bb, insn_info, flags);
2936 	      break;
2937 	    case STRICT_LOW_PART:
2938 	      {
2939 		rtx *temp = &XEXP (dst, 0);
2940 		/* A strict_low_part uses the whole REG and not just the
2941 		 SUBREG.  */
2942 		dst = XEXP (dst, 0);
2943 		df_uses_record (collection_rec,
2944 				(GET_CODE (dst) == SUBREG) ? &SUBREG_REG (dst) : temp,
2945 				DF_REF_REG_USE, bb, insn_info,
2946 				DF_REF_READ_WRITE | DF_REF_STRICT_LOW_PART);
2947 	      }
2948 	      break;
2949 	    case ZERO_EXTRACT:
2950 	      {
2951 		df_uses_record (collection_rec, &XEXP (dst, 1),
2952 				DF_REF_REG_USE, bb, insn_info, flags);
2953 		df_uses_record (collection_rec, &XEXP (dst, 2),
2954 				DF_REF_REG_USE, bb, insn_info, flags);
2955                 if (GET_CODE (XEXP (dst,0)) == MEM)
2956                   df_uses_record (collection_rec, &XEXP (dst, 0),
2957                                   DF_REF_REG_USE, bb, insn_info,
2958                                   flags);
2959                 else
2960                   df_uses_record (collection_rec, &XEXP (dst, 0),
2961                                   DF_REF_REG_USE, bb, insn_info,
2962                                   DF_REF_READ_WRITE | DF_REF_ZERO_EXTRACT);
2963 	      }
2964 	      break;
2965 
2966 	    default:
2967 	      gcc_unreachable ();
2968 	  }
2969 	return;
2970       }
2971 
2972     case RETURN:
2973     case SIMPLE_RETURN:
2974       break;
2975 
2976     case ASM_OPERANDS:
2977     case UNSPEC_VOLATILE:
2978     case TRAP_IF:
2979     case ASM_INPUT:
2980       {
2981 	/* Traditional and volatile asm instructions must be
2982 	   considered to use and clobber all hard registers, all
2983 	   pseudo-registers and all of memory.  So must TRAP_IF and
2984 	   UNSPEC_VOLATILE operations.
2985 
2986 	   Consider for instance a volatile asm that changes the fpu
2987 	   rounding mode.  An insn should not be moved across this
2988 	   even if it only uses pseudo-regs because it might give an
2989 	   incorrectly rounded result.
2990 
2991 	   However, flow.c's liveness computation did *not* do this,
2992 	   giving the reasoning as " ?!? Unfortunately, marking all
2993 	   hard registers as live causes massive problems for the
2994 	   register allocator and marking all pseudos as live creates
2995 	   mountains of uninitialized variable warnings."
2996 
2997 	   In order to maintain the status quo with regard to liveness
2998 	   and uses, we do what flow.c did and just mark any regs we
2999 	   can find in ASM_OPERANDS as used.  In global asm insns are
3000 	   scanned and regs_asm_clobbered is filled out.
3001 
3002 	   For all ASM_OPERANDS, we must traverse the vector of input
3003 	   operands.  We can not just fall through here since then we
3004 	   would be confused by the ASM_INPUT rtx inside ASM_OPERANDS,
3005 	   which do not indicate traditional asms unlike their normal
3006 	   usage.  */
3007 	if (code == ASM_OPERANDS)
3008 	  {
3009 	    int j;
3010 
3011 	    for (j = 0; j < ASM_OPERANDS_INPUT_LENGTH (x); j++)
3012 	      df_uses_record (collection_rec, &ASM_OPERANDS_INPUT (x, j),
3013 			      DF_REF_REG_USE, bb, insn_info, flags);
3014 	    return;
3015 	  }
3016 	break;
3017       }
3018 
3019     case VAR_LOCATION:
3020       df_uses_record (collection_rec,
3021 		      &PAT_VAR_LOCATION_LOC (x),
3022 		      DF_REF_REG_USE, bb, insn_info, flags);
3023       return;
3024 
3025     case PRE_DEC:
3026     case POST_DEC:
3027     case PRE_INC:
3028     case POST_INC:
3029     case PRE_MODIFY:
3030     case POST_MODIFY:
3031       gcc_assert (!DEBUG_INSN_P (insn_info->insn));
3032       /* Catch the def of the register being modified.  */
3033       df_ref_record (DF_REF_REGULAR, collection_rec, XEXP (x, 0), &XEXP (x, 0),
3034 		     bb, insn_info,
3035 		     DF_REF_REG_DEF,
3036                      flags | DF_REF_READ_WRITE | DF_REF_PRE_POST_MODIFY);
3037 
3038       /* ... Fall through to handle uses ...  */
3039 
3040     default:
3041       break;
3042     }
3043 
3044   /* Recursively scan the operands of this expression.  */
3045   {
3046     const char *fmt = GET_RTX_FORMAT (code);
3047     int i;
3048 
3049     for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
3050       {
3051 	if (fmt[i] == 'e')
3052 	  {
3053 	    /* Tail recursive case: save a function call level.  */
3054 	    if (i == 0)
3055 	      {
3056 		loc = &XEXP (x, 0);
3057 		goto retry;
3058 	      }
3059 	    df_uses_record (collection_rec, &XEXP (x, i), ref_type,
3060 			    bb, insn_info, flags);
3061 	  }
3062 	else if (fmt[i] == 'E')
3063 	  {
3064 	    int j;
3065 	    for (j = 0; j < XVECLEN (x, i); j++)
3066 	      df_uses_record (collection_rec,
3067 			      &XVECEXP (x, i, j), ref_type,
3068 			      bb, insn_info, flags);
3069 	  }
3070       }
3071   }
3072 
3073   return;
3074 }
3075 
3076 
3077 /* For all DF_REF_CONDITIONAL defs, add a corresponding uses.  */
3078 
3079 static void
3080 df_get_conditional_uses (struct df_collection_rec *collection_rec)
3081 {
3082   unsigned int ix;
3083   df_ref ref;
3084 
3085   FOR_EACH_VEC_ELT (collection_rec->def_vec, ix, ref)
3086     {
3087       if (DF_REF_FLAGS_IS_SET (ref, DF_REF_CONDITIONAL))
3088         {
3089           df_ref use;
3090 
3091           use = df_ref_create_structure (DF_REF_CLASS (ref), collection_rec, DF_REF_REG (ref),
3092 					 DF_REF_LOC (ref), DF_REF_BB (ref),
3093 					 DF_REF_INSN_INFO (ref), DF_REF_REG_USE,
3094 					 DF_REF_FLAGS (ref) & ~DF_REF_CONDITIONAL);
3095           DF_REF_REGNO (use) = DF_REF_REGNO (ref);
3096         }
3097     }
3098 }
3099 
3100 
3101 /* Get call's extra defs and uses (track caller-saved registers). */
3102 
3103 static void
3104 df_get_call_refs (struct df_collection_rec *collection_rec,
3105                   basic_block bb,
3106                   struct df_insn_info *insn_info,
3107                   int flags)
3108 {
3109   rtx note;
3110   bool is_sibling_call;
3111   unsigned int i;
3112   HARD_REG_SET defs_generated;
3113   HARD_REG_SET fn_reg_set_usage;
3114 
3115   CLEAR_HARD_REG_SET (defs_generated);
3116   df_find_hard_reg_defs (PATTERN (insn_info->insn), &defs_generated);
3117   is_sibling_call = SIBLING_CALL_P (insn_info->insn);
3118   get_call_reg_set_usage (insn_info->insn, &fn_reg_set_usage,
3119 			  regs_invalidated_by_call);
3120 
3121   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3122     {
3123       if (i == STACK_POINTER_REGNUM)
3124 	/* The stack ptr is used (honorarily) by a CALL insn.  */
3125 	df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3126 		       NULL, bb, insn_info, DF_REF_REG_USE,
3127 		       DF_REF_CALL_STACK_USAGE | flags);
3128       else if (global_regs[i])
3129 	{
3130 	  /* Calls to const functions cannot access any global registers and
3131 	     calls to pure functions cannot set them.  All other calls may
3132 	     reference any of the global registers, so they are recorded as
3133 	     used. */
3134 	  if (!RTL_CONST_CALL_P (insn_info->insn))
3135 	    {
3136 	      df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3137 			     NULL, bb, insn_info, DF_REF_REG_USE, flags);
3138 	      if (!RTL_PURE_CALL_P (insn_info->insn))
3139 		df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3140 			       NULL, bb, insn_info, DF_REF_REG_DEF, flags);
3141 	    }
3142 	}
3143       else if (TEST_HARD_REG_BIT (fn_reg_set_usage, i)
3144 	       /* no clobbers for regs that are the result of the call */
3145 	       && !TEST_HARD_REG_BIT (defs_generated, i)
3146 	       && (!is_sibling_call
3147 		   || !bitmap_bit_p (df->exit_block_uses, i)
3148 		   || refers_to_regno_p (i, crtl->return_rtx)))
3149 	  df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3150 			 NULL, bb, insn_info, DF_REF_REG_DEF,
3151 			 DF_REF_MAY_CLOBBER | flags);
3152     }
3153 
3154   /* Record the registers used to pass arguments, and explicitly
3155      noted as clobbered.  */
3156   for (note = CALL_INSN_FUNCTION_USAGE (insn_info->insn); note;
3157        note = XEXP (note, 1))
3158     {
3159       if (GET_CODE (XEXP (note, 0)) == USE)
3160         df_uses_record (collection_rec, &XEXP (XEXP (note, 0), 0),
3161 			DF_REF_REG_USE, bb, insn_info, flags);
3162       else if (GET_CODE (XEXP (note, 0)) == CLOBBER)
3163 	{
3164 	  if (REG_P (XEXP (XEXP (note, 0), 0)))
3165 	    {
3166 	      unsigned int regno = REGNO (XEXP (XEXP (note, 0), 0));
3167 	      if (!TEST_HARD_REG_BIT (defs_generated, regno))
3168 		df_defs_record (collection_rec, XEXP (note, 0), bb,
3169 				insn_info, flags);
3170 	    }
3171 	  else
3172 	    df_uses_record (collection_rec, &XEXP (note, 0),
3173 		            DF_REF_REG_USE, bb, insn_info, flags);
3174 	}
3175     }
3176 
3177   return;
3178 }
3179 
3180 /* Collect all refs in the INSN. This function is free of any
3181    side-effect - it will create and return a lists of df_ref's in the
3182    COLLECTION_REC without putting those refs into existing ref chains
3183    and reg chains. */
3184 
3185 static void
3186 df_insn_refs_collect (struct df_collection_rec *collection_rec,
3187 		      basic_block bb, struct df_insn_info *insn_info)
3188 {
3189   rtx note;
3190   bool is_cond_exec = (GET_CODE (PATTERN (insn_info->insn)) == COND_EXEC);
3191 
3192   /* Clear out the collection record.  */
3193   collection_rec->def_vec.truncate (0);
3194   collection_rec->use_vec.truncate (0);
3195   collection_rec->eq_use_vec.truncate (0);
3196   collection_rec->mw_vec.truncate (0);
3197 
3198   /* Process REG_EQUIV/REG_EQUAL notes.  */
3199   for (note = REG_NOTES (insn_info->insn); note;
3200        note = XEXP (note, 1))
3201     {
3202       switch (REG_NOTE_KIND (note))
3203         {
3204         case REG_EQUIV:
3205         case REG_EQUAL:
3206           df_uses_record (collection_rec,
3207                           &XEXP (note, 0), DF_REF_REG_USE,
3208                           bb, insn_info, DF_REF_IN_NOTE);
3209           break;
3210         case REG_NON_LOCAL_GOTO:
3211           /* The frame ptr is used by a non-local goto.  */
3212           df_ref_record (DF_REF_BASE, collection_rec,
3213                          regno_reg_rtx[FRAME_POINTER_REGNUM],
3214                          NULL, bb, insn_info,
3215                          DF_REF_REG_USE, 0);
3216 	  if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
3217 	    df_ref_record (DF_REF_BASE, collection_rec,
3218 			   regno_reg_rtx[HARD_FRAME_POINTER_REGNUM],
3219 			   NULL, bb, insn_info,
3220 			   DF_REF_REG_USE, 0);
3221           break;
3222         default:
3223           break;
3224         }
3225     }
3226 
3227   int flags = (is_cond_exec) ? DF_REF_CONDITIONAL : 0;
3228   /* For CALL_INSNs, first record DF_REF_BASE register defs, as well as
3229      uses from CALL_INSN_FUNCTION_USAGE. */
3230   if (CALL_P (insn_info->insn))
3231     df_get_call_refs (collection_rec, bb, insn_info, flags);
3232 
3233   if (asm_noperands (PATTERN (insn_info->insn)) >= 0)
3234     for (unsigned i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3235       if (global_regs[i])
3236        {
3237          /* As with calls, asm statements reference all global regs. */
3238          df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3239                         NULL, bb, insn_info, DF_REF_REG_USE, flags);
3240          df_ref_record (DF_REF_BASE, collection_rec, regno_reg_rtx[i],
3241                         NULL, bb, insn_info, DF_REF_REG_DEF, flags);
3242        }
3243 
3244   /* Record other defs.  These should be mostly for DF_REF_REGULAR, so
3245      that a qsort on the defs is unnecessary in most cases.  */
3246   df_defs_record (collection_rec,
3247 		  PATTERN (insn_info->insn), bb, insn_info, 0);
3248 
3249   /* Record the register uses.  */
3250   df_uses_record (collection_rec,
3251 		  &PATTERN (insn_info->insn), DF_REF_REG_USE, bb, insn_info, 0);
3252 
3253   /* DF_REF_CONDITIONAL needs corresponding USES. */
3254   if (is_cond_exec)
3255     df_get_conditional_uses (collection_rec);
3256 
3257   df_canonize_collection_rec (collection_rec);
3258 }
3259 
3260 /* Recompute the luids for the insns in BB.  */
3261 
3262 void
3263 df_recompute_luids (basic_block bb)
3264 {
3265   rtx_insn *insn;
3266   int luid = 0;
3267 
3268   df_grow_insn_info ();
3269 
3270   /* Scan the block an insn at a time from beginning to end.  */
3271   FOR_BB_INSNS (bb, insn)
3272     {
3273       struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
3274       /* Inserting labels does not always trigger the incremental
3275 	 rescanning.  */
3276       if (!insn_info)
3277 	{
3278 	  gcc_assert (!INSN_P (insn));
3279 	  insn_info = df_insn_create_insn_record (insn);
3280 	}
3281 
3282       DF_INSN_INFO_LUID (insn_info) = luid;
3283       if (INSN_P (insn))
3284 	luid++;
3285     }
3286 }
3287 
3288 
3289 /* Collect all artificial refs at the block level for BB and add them
3290    to COLLECTION_REC.  */
3291 
3292 static void
3293 df_bb_refs_collect (struct df_collection_rec *collection_rec, basic_block bb)
3294 {
3295   collection_rec->def_vec.truncate (0);
3296   collection_rec->use_vec.truncate (0);
3297   collection_rec->eq_use_vec.truncate (0);
3298   collection_rec->mw_vec.truncate (0);
3299 
3300   if (bb->index == ENTRY_BLOCK)
3301     {
3302       df_entry_block_defs_collect (collection_rec, df->entry_block_defs);
3303       return;
3304     }
3305   else if (bb->index == EXIT_BLOCK)
3306     {
3307       df_exit_block_uses_collect (collection_rec, df->exit_block_uses);
3308       return;
3309     }
3310 
3311   if (bb_has_eh_pred (bb))
3312     {
3313       unsigned int i;
3314       /* Mark the registers that will contain data for the handler.  */
3315       for (i = 0; ; ++i)
3316 	{
3317 	  unsigned regno = EH_RETURN_DATA_REGNO (i);
3318 	  if (regno == INVALID_REGNUM)
3319 	    break;
3320 	  df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[regno], NULL,
3321 			 bb, NULL, DF_REF_REG_DEF, DF_REF_AT_TOP);
3322 	}
3323     }
3324 
3325   /* Add the hard_frame_pointer if this block is the target of a
3326      non-local goto.  */
3327   if (bb->flags & BB_NON_LOCAL_GOTO_TARGET)
3328     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, hard_frame_pointer_rtx, NULL,
3329 		   bb, NULL, DF_REF_REG_DEF, DF_REF_AT_TOP);
3330 
3331   /* Add the artificial uses.  */
3332   if (bb->index >= NUM_FIXED_BLOCKS)
3333     {
3334       bitmap_iterator bi;
3335       unsigned int regno;
3336       bitmap au = bb_has_eh_pred (bb)
3337 	? &df->eh_block_artificial_uses
3338 	: &df->regular_block_artificial_uses;
3339 
3340       EXECUTE_IF_SET_IN_BITMAP (au, 0, regno, bi)
3341 	{
3342 	  df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[regno], NULL,
3343 			 bb, NULL, DF_REF_REG_USE, 0);
3344 	}
3345     }
3346 
3347   df_canonize_collection_rec (collection_rec);
3348 }
3349 
3350 
3351 /* Record all the refs within the basic block BB_INDEX and scan the instructions if SCAN_INSNS.  */
3352 
3353 void
3354 df_bb_refs_record (int bb_index, bool scan_insns)
3355 {
3356   basic_block bb = BASIC_BLOCK_FOR_FN (cfun, bb_index);
3357   rtx_insn *insn;
3358   int luid = 0;
3359 
3360   if (!df)
3361     return;
3362 
3363   df_collection_rec collection_rec;
3364   df_grow_bb_info (df_scan);
3365   if (scan_insns)
3366     /* Scan the block an insn at a time from beginning to end.  */
3367     FOR_BB_INSNS (bb, insn)
3368       {
3369 	struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
3370 	gcc_assert (!insn_info);
3371 
3372 	insn_info = df_insn_create_insn_record (insn);
3373 	if (INSN_P (insn))
3374 	  {
3375 	    /* Record refs within INSN.  */
3376 	    DF_INSN_INFO_LUID (insn_info) = luid++;
3377 	    df_insn_refs_collect (&collection_rec, bb, DF_INSN_INFO_GET (insn));
3378 	    df_refs_add_to_chains (&collection_rec, bb, insn, copy_all);
3379 	  }
3380 	DF_INSN_INFO_LUID (insn_info) = luid;
3381       }
3382 
3383   /* Other block level artificial refs */
3384   df_bb_refs_collect (&collection_rec, bb);
3385   df_refs_add_to_chains (&collection_rec, bb, NULL, copy_all);
3386 
3387   /* Now that the block has been processed, set the block as dirty so
3388      LR and LIVE will get it processed.  */
3389   df_set_bb_dirty (bb);
3390 }
3391 
3392 
3393 /* Get the artificial use set for a regular (i.e. non-exit/non-entry)
3394    block. */
3395 
3396 static void
3397 df_get_regular_block_artificial_uses (bitmap regular_block_artificial_uses)
3398 {
3399 #ifdef EH_USES
3400   unsigned int i;
3401 #endif
3402 
3403   bitmap_clear (regular_block_artificial_uses);
3404 
3405   if (reload_completed)
3406     {
3407       if (frame_pointer_needed)
3408 	bitmap_set_bit (regular_block_artificial_uses, HARD_FRAME_POINTER_REGNUM);
3409     }
3410   else
3411     /* Before reload, there are a few registers that must be forced
3412        live everywhere -- which might not already be the case for
3413        blocks within infinite loops.  */
3414     {
3415       unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3416 
3417       /* Any reference to any pseudo before reload is a potential
3418 	 reference of the frame pointer.  */
3419       bitmap_set_bit (regular_block_artificial_uses, FRAME_POINTER_REGNUM);
3420 
3421       if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
3422 	bitmap_set_bit (regular_block_artificial_uses,
3423 			HARD_FRAME_POINTER_REGNUM);
3424 
3425       /* Pseudos with argument area equivalences may require
3426 	 reloading via the argument pointer.  */
3427       if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3428 	  && fixed_regs[ARG_POINTER_REGNUM])
3429 	bitmap_set_bit (regular_block_artificial_uses, ARG_POINTER_REGNUM);
3430 
3431       /* Any constant, or pseudo with constant equivalences, may
3432 	 require reloading from memory using the pic register.  */
3433       if (picreg != INVALID_REGNUM
3434 	  && fixed_regs[picreg])
3435 	bitmap_set_bit (regular_block_artificial_uses, picreg);
3436     }
3437   /* The all-important stack pointer must always be live.  */
3438   bitmap_set_bit (regular_block_artificial_uses, STACK_POINTER_REGNUM);
3439 
3440 #ifdef EH_USES
3441   /* EH_USES registers are used:
3442      1) at all insns that might throw (calls or with -fnon-call-exceptions
3443 	trapping insns)
3444      2) in all EH edges
3445      3) to support backtraces and/or debugging, anywhere between their
3446 	initialization and where they the saved registers are restored
3447 	from them, including the cases where we don't reach the epilogue
3448 	(noreturn call or infinite loop).  */
3449   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3450     if (EH_USES (i))
3451       bitmap_set_bit (regular_block_artificial_uses, i);
3452 #endif
3453 }
3454 
3455 
3456 /* Get the artificial use set for an eh block. */
3457 
3458 static void
3459 df_get_eh_block_artificial_uses (bitmap eh_block_artificial_uses)
3460 {
3461   bitmap_clear (eh_block_artificial_uses);
3462 
3463   /* The following code (down through the arg_pointer setting APPEARS
3464      to be necessary because there is nothing that actually
3465      describes what the exception handling code may actually need
3466      to keep alive.  */
3467   if (reload_completed)
3468     {
3469       if (frame_pointer_needed)
3470 	{
3471 	  bitmap_set_bit (eh_block_artificial_uses, FRAME_POINTER_REGNUM);
3472 	  if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
3473 	    bitmap_set_bit (eh_block_artificial_uses,
3474 			    HARD_FRAME_POINTER_REGNUM);
3475 	}
3476       if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3477 	  && fixed_regs[ARG_POINTER_REGNUM])
3478 	bitmap_set_bit (eh_block_artificial_uses, ARG_POINTER_REGNUM);
3479     }
3480 }
3481 
3482 
3483 
3484 /*----------------------------------------------------------------------------
3485    Specialized hard register scanning functions.
3486 ----------------------------------------------------------------------------*/
3487 
3488 
3489 /* Mark a register in SET.  Hard registers in large modes get all
3490    of their component registers set as well.  */
3491 
3492 static void
3493 df_mark_reg (rtx reg, void *vset)
3494 {
3495   bitmap_set_range ((bitmap) vset, REGNO (reg), REG_NREGS (reg));
3496 }
3497 
3498 
3499 /* Set the bit for regs that are considered being defined at the entry. */
3500 
3501 static void
3502 df_get_entry_block_def_set (bitmap entry_block_defs)
3503 {
3504   rtx r;
3505   int i;
3506 
3507   bitmap_clear (entry_block_defs);
3508 
3509   /* For separate shrink-wrapping we use LIVE to analyze which basic blocks
3510      need a prologue for some component to be executed before that block,
3511      and we do not care about any other registers.  Hence, we do not want
3512      any register for any component defined in the entry block, and we can
3513      just leave all registers undefined.  */
3514   if (df_scan->local_flags & DF_SCAN_EMPTY_ENTRY_EXIT)
3515     return;
3516 
3517   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3518     {
3519       if (global_regs[i])
3520 	bitmap_set_bit (entry_block_defs, i);
3521       if (FUNCTION_ARG_REGNO_P (i))
3522 	bitmap_set_bit (entry_block_defs, INCOMING_REGNO (i));
3523     }
3524 
3525   /* The always important stack pointer.  */
3526   bitmap_set_bit (entry_block_defs, STACK_POINTER_REGNUM);
3527 
3528   /* Once the prologue has been generated, all of these registers
3529      should just show up in the first regular block.  */
3530   if (targetm.have_prologue () && epilogue_completed)
3531     {
3532       /* Defs for the callee saved registers are inserted so that the
3533 	 pushes have some defining location.  */
3534       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3535 	if ((call_used_regs[i] == 0) && (df_regs_ever_live_p (i)))
3536 	  bitmap_set_bit (entry_block_defs, i);
3537     }
3538 
3539   r = targetm.calls.struct_value_rtx (current_function_decl, true);
3540   if (r && REG_P (r))
3541     bitmap_set_bit (entry_block_defs, REGNO (r));
3542 
3543   /* If the function has an incoming STATIC_CHAIN, it has to show up
3544      in the entry def set.  */
3545   r = targetm.calls.static_chain (current_function_decl, true);
3546   if (r && REG_P (r))
3547     bitmap_set_bit (entry_block_defs, REGNO (r));
3548 
3549   if ((!reload_completed) || frame_pointer_needed)
3550     {
3551       /* Any reference to any pseudo before reload is a potential
3552 	 reference of the frame pointer.  */
3553       bitmap_set_bit (entry_block_defs, FRAME_POINTER_REGNUM);
3554 
3555       /* If they are different, also mark the hard frame pointer as live.  */
3556       if (!HARD_FRAME_POINTER_IS_FRAME_POINTER
3557 	  && !LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM))
3558 	bitmap_set_bit (entry_block_defs, HARD_FRAME_POINTER_REGNUM);
3559     }
3560 
3561   /* These registers are live everywhere.  */
3562   if (!reload_completed)
3563     {
3564       /* Pseudos with argument area equivalences may require
3565 	 reloading via the argument pointer.  */
3566       if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3567 	  && fixed_regs[ARG_POINTER_REGNUM])
3568 	bitmap_set_bit (entry_block_defs, ARG_POINTER_REGNUM);
3569 
3570       /* Any constant, or pseudo with constant equivalences, may
3571 	 require reloading from memory using the pic register.  */
3572       unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3573       if (picreg != INVALID_REGNUM
3574 	  && fixed_regs[picreg])
3575 	bitmap_set_bit (entry_block_defs, picreg);
3576     }
3577 
3578 #ifdef INCOMING_RETURN_ADDR_RTX
3579   if (REG_P (INCOMING_RETURN_ADDR_RTX))
3580     bitmap_set_bit (entry_block_defs, REGNO (INCOMING_RETURN_ADDR_RTX));
3581 #endif
3582 
3583   targetm.extra_live_on_entry (entry_block_defs);
3584 }
3585 
3586 
3587 /* Return the (conservative) set of hard registers that are defined on
3588    entry to the function.
3589    It uses df->entry_block_defs to determine which register
3590    reference to include.  */
3591 
3592 static void
3593 df_entry_block_defs_collect (struct df_collection_rec *collection_rec,
3594 			     bitmap entry_block_defs)
3595 {
3596   unsigned int i;
3597   bitmap_iterator bi;
3598 
3599   EXECUTE_IF_SET_IN_BITMAP (entry_block_defs, 0, i, bi)
3600     {
3601       df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[i], NULL,
3602 		     ENTRY_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_DEF, 0);
3603     }
3604 
3605   df_canonize_collection_rec (collection_rec);
3606 }
3607 
3608 
3609 /* Record the (conservative) set of hard registers that are defined on
3610    entry to the function.  */
3611 
3612 static void
3613 df_record_entry_block_defs (bitmap entry_block_defs)
3614 {
3615   struct df_collection_rec collection_rec;
3616   df_entry_block_defs_collect (&collection_rec, entry_block_defs);
3617 
3618   /* Process bb_refs chain */
3619   df_refs_add_to_chains (&collection_rec,
3620 			 BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK),
3621 			 NULL,
3622 			 copy_defs);
3623 }
3624 
3625 
3626 /* Update the defs in the entry block.  */
3627 
3628 void
3629 df_update_entry_block_defs (void)
3630 {
3631   bitmap_head refs;
3632   bool changed = false;
3633 
3634   bitmap_initialize (&refs, &df_bitmap_obstack);
3635   df_get_entry_block_def_set (&refs);
3636   if (df->entry_block_defs)
3637     {
3638       if (!bitmap_equal_p (df->entry_block_defs, &refs))
3639 	{
3640 	  struct df_scan_bb_info *bb_info = df_scan_get_bb_info (ENTRY_BLOCK);
3641 	  df_ref_chain_delete_du_chain (bb_info->artificial_defs);
3642 	  df_ref_chain_delete (bb_info->artificial_defs);
3643 	  bb_info->artificial_defs = NULL;
3644 	  changed = true;
3645 	}
3646     }
3647   else
3648     {
3649       struct df_scan_problem_data *problem_data
3650 	= (struct df_scan_problem_data *) df_scan->problem_data;
3651 	gcc_unreachable ();
3652       df->entry_block_defs = BITMAP_ALLOC (&problem_data->reg_bitmaps);
3653       changed = true;
3654     }
3655 
3656   if (changed)
3657     {
3658       df_record_entry_block_defs (&refs);
3659       bitmap_copy (df->entry_block_defs, &refs);
3660       df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, ENTRY_BLOCK));
3661     }
3662   bitmap_clear (&refs);
3663 }
3664 
3665 
3666 /* Set the bit for regs that are considered being used at the exit. */
3667 
3668 static void
3669 df_get_exit_block_use_set (bitmap exit_block_uses)
3670 {
3671   unsigned int i;
3672   unsigned int picreg = PIC_OFFSET_TABLE_REGNUM;
3673 
3674   bitmap_clear (exit_block_uses);
3675 
3676   /* For separate shrink-wrapping we use LIVE to analyze which basic blocks
3677      need an epilogue for some component to be executed after that block,
3678      and we do not care about any other registers.  Hence, we do not want
3679      any register for any component seen as used in the exit block, and we
3680      can just say no registers at all are used.  */
3681   if (df_scan->local_flags & DF_SCAN_EMPTY_ENTRY_EXIT)
3682     return;
3683 
3684   /* Stack pointer is always live at the exit.  */
3685   bitmap_set_bit (exit_block_uses, STACK_POINTER_REGNUM);
3686 
3687   /* Mark the frame pointer if needed at the end of the function.
3688      If we end up eliminating it, it will be removed from the live
3689      list of each basic block by reload.  */
3690 
3691   if ((!reload_completed) || frame_pointer_needed)
3692     {
3693       bitmap_set_bit (exit_block_uses, FRAME_POINTER_REGNUM);
3694 
3695       /* If they are different, also mark the hard frame pointer as live.  */
3696       if (!HARD_FRAME_POINTER_IS_FRAME_POINTER
3697 	  && !LOCAL_REGNO (HARD_FRAME_POINTER_REGNUM))
3698 	bitmap_set_bit (exit_block_uses, HARD_FRAME_POINTER_REGNUM);
3699     }
3700 
3701   /* Many architectures have a GP register even without flag_pic.
3702      Assume the pic register is not in use, or will be handled by
3703      other means, if it is not fixed.  */
3704   if (!PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
3705       && picreg != INVALID_REGNUM
3706       && fixed_regs[picreg])
3707     bitmap_set_bit (exit_block_uses, picreg);
3708 
3709   /* Mark all global registers, and all registers used by the
3710      epilogue as being live at the end of the function since they
3711      may be referenced by our caller.  */
3712   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3713     if (global_regs[i] || EPILOGUE_USES (i))
3714       bitmap_set_bit (exit_block_uses, i);
3715 
3716   if (targetm.have_epilogue () && epilogue_completed)
3717     {
3718       /* Mark all call-saved registers that we actually used.  */
3719       for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3720 	if (df_regs_ever_live_p (i) && !LOCAL_REGNO (i)
3721 	    && !TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
3722 	  bitmap_set_bit (exit_block_uses, i);
3723     }
3724 
3725   /* Mark the registers that will contain data for the handler.  */
3726   if (reload_completed && crtl->calls_eh_return)
3727     for (i = 0; ; ++i)
3728       {
3729 	unsigned regno = EH_RETURN_DATA_REGNO (i);
3730 	if (regno == INVALID_REGNUM)
3731 	  break;
3732 	bitmap_set_bit (exit_block_uses, regno);
3733       }
3734 
3735 #ifdef EH_RETURN_STACKADJ_RTX
3736   if ((!targetm.have_epilogue () || ! epilogue_completed)
3737       && crtl->calls_eh_return)
3738     {
3739       rtx tmp = EH_RETURN_STACKADJ_RTX;
3740       if (tmp && REG_P (tmp))
3741 	df_mark_reg (tmp, exit_block_uses);
3742     }
3743 #endif
3744 
3745   if ((!targetm.have_epilogue () || ! epilogue_completed)
3746       && crtl->calls_eh_return)
3747     {
3748       rtx tmp = EH_RETURN_HANDLER_RTX;
3749       if (tmp && REG_P (tmp))
3750 	df_mark_reg (tmp, exit_block_uses);
3751     }
3752 
3753   /* Mark function return value.  */
3754   diddle_return_value (df_mark_reg, (void*) exit_block_uses);
3755 }
3756 
3757 
3758 /* Return the refs of hard registers that are used in the exit block.
3759    It uses df->exit_block_uses to determine register to include.  */
3760 
3761 static void
3762 df_exit_block_uses_collect (struct df_collection_rec *collection_rec, bitmap exit_block_uses)
3763 {
3764   unsigned int i;
3765   bitmap_iterator bi;
3766 
3767   EXECUTE_IF_SET_IN_BITMAP (exit_block_uses, 0, i, bi)
3768     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[i], NULL,
3769 		   EXIT_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_USE, 0);
3770 
3771   /* It is deliberate that this is not put in the exit block uses but
3772      I do not know why.  */
3773   if (FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3774       && reload_completed
3775       && !bitmap_bit_p (exit_block_uses, ARG_POINTER_REGNUM)
3776       && bb_has_eh_pred (EXIT_BLOCK_PTR_FOR_FN (cfun))
3777       && fixed_regs[ARG_POINTER_REGNUM])
3778     df_ref_record (DF_REF_ARTIFICIAL, collection_rec, regno_reg_rtx[ARG_POINTER_REGNUM], NULL,
3779 		   EXIT_BLOCK_PTR_FOR_FN (cfun), NULL, DF_REF_REG_USE, 0);
3780 
3781   df_canonize_collection_rec (collection_rec);
3782 }
3783 
3784 
3785 /* Record the set of hard registers that are used in the exit block.
3786    It uses df->exit_block_uses to determine which bit to include.  */
3787 
3788 static void
3789 df_record_exit_block_uses (bitmap exit_block_uses)
3790 {
3791   struct df_collection_rec collection_rec;
3792   df_exit_block_uses_collect (&collection_rec, exit_block_uses);
3793 
3794   /* Process bb_refs chain */
3795   df_refs_add_to_chains (&collection_rec,
3796 			 BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK),
3797 			 NULL,
3798 			 copy_uses);
3799 }
3800 
3801 
3802 /* Update the uses in the exit block.  */
3803 
3804 void
3805 df_update_exit_block_uses (void)
3806 {
3807   bitmap_head refs;
3808   bool changed = false;
3809 
3810   bitmap_initialize (&refs, &df_bitmap_obstack);
3811   df_get_exit_block_use_set (&refs);
3812   if (df->exit_block_uses)
3813     {
3814       if (!bitmap_equal_p (df->exit_block_uses, &refs))
3815 	{
3816 	  struct df_scan_bb_info *bb_info = df_scan_get_bb_info (EXIT_BLOCK);
3817 	  df_ref_chain_delete_du_chain (bb_info->artificial_uses);
3818 	  df_ref_chain_delete (bb_info->artificial_uses);
3819 	  bb_info->artificial_uses = NULL;
3820 	  changed = true;
3821 	}
3822     }
3823   else
3824     {
3825       struct df_scan_problem_data *problem_data
3826 	= (struct df_scan_problem_data *) df_scan->problem_data;
3827 	gcc_unreachable ();
3828       df->exit_block_uses = BITMAP_ALLOC (&problem_data->reg_bitmaps);
3829       changed = true;
3830     }
3831 
3832   if (changed)
3833     {
3834       df_record_exit_block_uses (&refs);
3835       bitmap_copy (df->exit_block_uses,& refs);
3836       df_set_bb_dirty (BASIC_BLOCK_FOR_FN (cfun, EXIT_BLOCK));
3837     }
3838   bitmap_clear (&refs);
3839 }
3840 
3841 static bool initialized = false;
3842 
3843 
3844 /* Initialize some platform specific structures.  */
3845 
3846 void
3847 df_hard_reg_init (void)
3848 {
3849   int i;
3850   static const struct {const int from, to; } eliminables[] = ELIMINABLE_REGS;
3851 
3852   if (initialized)
3853     return;
3854 
3855   /* Record which registers will be eliminated.  We use this in
3856      mark_used_regs.  */
3857   CLEAR_HARD_REG_SET (elim_reg_set);
3858 
3859   for (i = 0; i < (int) ARRAY_SIZE (eliminables); i++)
3860     SET_HARD_REG_BIT (elim_reg_set, eliminables[i].from);
3861 
3862   initialized = true;
3863 }
3864 
3865 
3866 /* Recompute the parts of scanning that are based on regs_ever_live
3867    because something changed in that array.  */
3868 
3869 void
3870 df_update_entry_exit_and_calls (void)
3871 {
3872   basic_block bb;
3873 
3874   df_update_entry_block_defs ();
3875   df_update_exit_block_uses ();
3876 
3877   /* The call insns need to be rescanned because there may be changes
3878      in the set of registers clobbered across the call.  */
3879   FOR_EACH_BB_FN (bb, cfun)
3880     {
3881       rtx_insn *insn;
3882       FOR_BB_INSNS (bb, insn)
3883 	{
3884 	  if (INSN_P (insn) && CALL_P (insn))
3885 	    df_insn_rescan (insn);
3886 	}
3887     }
3888 }
3889 
3890 
3891 /* Return true if hard REG is actually used in the some instruction.
3892    There are a fair number of conditions that affect the setting of
3893    this array.  See the comment in df.h for df->hard_regs_live_count
3894    for the conditions that this array is set. */
3895 
3896 bool
3897 df_hard_reg_used_p (unsigned int reg)
3898 {
3899   return df->hard_regs_live_count[reg] != 0;
3900 }
3901 
3902 
3903 /* A count of the number of times REG is actually used in the some
3904    instruction.  There are a fair number of conditions that affect the
3905    setting of this array.  See the comment in df.h for
3906    df->hard_regs_live_count for the conditions that this array is
3907    set. */
3908 
3909 
3910 unsigned int
3911 df_hard_reg_used_count (unsigned int reg)
3912 {
3913   return df->hard_regs_live_count[reg];
3914 }
3915 
3916 
3917 /* Get the value of regs_ever_live[REGNO].  */
3918 
3919 bool
3920 df_regs_ever_live_p (unsigned int regno)
3921 {
3922   return regs_ever_live[regno];
3923 }
3924 
3925 
3926 /* Set regs_ever_live[REGNO] to VALUE.  If this cause regs_ever_live
3927    to change, schedule that change for the next update.  */
3928 
3929 void
3930 df_set_regs_ever_live (unsigned int regno, bool value)
3931 {
3932   if (regs_ever_live[regno] == value)
3933     return;
3934 
3935   regs_ever_live[regno] = value;
3936   if (df)
3937     df->redo_entry_and_exit = true;
3938 }
3939 
3940 
3941 /* Compute "regs_ever_live" information from the underlying df
3942    information.  Set the vector to all false if RESET.  */
3943 
3944 void
3945 df_compute_regs_ever_live (bool reset)
3946 {
3947   unsigned int i;
3948   bool changed = df->redo_entry_and_exit;
3949 
3950   if (reset)
3951     memset (regs_ever_live, 0, sizeof (regs_ever_live));
3952 
3953   for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
3954     if ((!regs_ever_live[i]) && df_hard_reg_used_p (i))
3955       {
3956 	regs_ever_live[i] = true;
3957 	changed = true;
3958       }
3959   if (changed)
3960     df_update_entry_exit_and_calls ();
3961   df->redo_entry_and_exit = false;
3962 }
3963 
3964 
3965 /*----------------------------------------------------------------------------
3966   Dataflow ref information verification functions.
3967 
3968   df_reg_chain_mark (refs, regno, is_def, is_eq_use)
3969   df_reg_chain_verify_unmarked (refs)
3970   df_refs_verify (vec<stack, va_df_ref>, ref*, bool)
3971   df_mws_verify (mw*, mw*, bool)
3972   df_insn_refs_verify (collection_rec, bb, insn, bool)
3973   df_bb_refs_verify (bb, refs, bool)
3974   df_bb_verify (bb)
3975   df_exit_block_bitmap_verify (bool)
3976   df_entry_block_bitmap_verify (bool)
3977   df_scan_verify ()
3978 ----------------------------------------------------------------------------*/
3979 
3980 
3981 /* Mark all refs in the reg chain.  Verify that all of the registers
3982 are in the correct chain.  */
3983 
3984 static unsigned int
3985 df_reg_chain_mark (df_ref refs, unsigned int regno,
3986 		   bool is_def, bool is_eq_use)
3987 {
3988   unsigned int count = 0;
3989   df_ref ref;
3990   for (ref = refs; ref; ref = DF_REF_NEXT_REG (ref))
3991     {
3992       gcc_assert (!DF_REF_IS_REG_MARKED (ref));
3993 
3994       /* If there are no def-use or use-def chains, make sure that all
3995 	 of the chains are clear.  */
3996       if (!df_chain)
3997 	gcc_assert (!DF_REF_CHAIN (ref));
3998 
3999       /* Check to make sure the ref is in the correct chain.  */
4000       gcc_assert (DF_REF_REGNO (ref) == regno);
4001       if (is_def)
4002 	gcc_assert (DF_REF_REG_DEF_P (ref));
4003       else
4004 	gcc_assert (!DF_REF_REG_DEF_P (ref));
4005 
4006       if (is_eq_use)
4007 	gcc_assert ((DF_REF_FLAGS (ref) & DF_REF_IN_NOTE));
4008       else
4009 	gcc_assert ((DF_REF_FLAGS (ref) & DF_REF_IN_NOTE) == 0);
4010 
4011       if (DF_REF_NEXT_REG (ref))
4012 	gcc_assert (DF_REF_PREV_REG (DF_REF_NEXT_REG (ref)) == ref);
4013       count++;
4014       DF_REF_REG_MARK (ref);
4015     }
4016   return count;
4017 }
4018 
4019 
4020 /* Verify that all of the registers in the chain are unmarked.  */
4021 
4022 static void
4023 df_reg_chain_verify_unmarked (df_ref refs)
4024 {
4025   df_ref ref;
4026   for (ref = refs; ref; ref = DF_REF_NEXT_REG (ref))
4027     gcc_assert (!DF_REF_IS_REG_MARKED (ref));
4028 }
4029 
4030 
4031 /* Verify that NEW_REC and OLD_REC have exactly the same members. */
4032 
4033 static bool
4034 df_refs_verify (const vec<df_ref, va_heap> *new_rec, df_ref old_rec,
4035 		bool abort_if_fail)
4036 {
4037   unsigned int ix;
4038   df_ref new_ref;
4039 
4040   FOR_EACH_VEC_ELT (*new_rec, ix, new_ref)
4041     {
4042       if (old_rec == NULL || !df_ref_equal_p (new_ref, old_rec))
4043 	{
4044 	  if (abort_if_fail)
4045 	    gcc_assert (0);
4046 	  else
4047 	    return false;
4048 	}
4049 
4050       /* Abort if fail is called from the function level verifier.  If
4051 	 that is the context, mark this reg as being seem.  */
4052       if (abort_if_fail)
4053 	{
4054 	  gcc_assert (DF_REF_IS_REG_MARKED (old_rec));
4055 	  DF_REF_REG_UNMARK (old_rec);
4056 	}
4057 
4058       old_rec = DF_REF_NEXT_LOC (old_rec);
4059     }
4060 
4061   if (abort_if_fail)
4062     gcc_assert (old_rec == NULL);
4063   else
4064     return old_rec == NULL;
4065   return false;
4066 }
4067 
4068 
4069 /* Verify that NEW_REC and OLD_REC have exactly the same members. */
4070 
4071 static bool
4072 df_mws_verify (const vec<df_mw_hardreg *, va_heap> *new_rec,
4073 	       struct df_mw_hardreg *old_rec,
4074 	       bool abort_if_fail)
4075 {
4076   unsigned int ix;
4077   struct df_mw_hardreg *new_reg;
4078 
4079   FOR_EACH_VEC_ELT (*new_rec, ix, new_reg)
4080     {
4081       if (old_rec == NULL || !df_mw_equal_p (new_reg, old_rec))
4082 	{
4083 	  if (abort_if_fail)
4084 	    gcc_assert (0);
4085 	  else
4086 	    return false;
4087 	}
4088       old_rec = DF_MWS_NEXT (old_rec);
4089     }
4090 
4091   if (abort_if_fail)
4092     gcc_assert (old_rec == NULL);
4093   else
4094     return old_rec == NULL;
4095   return false;
4096 }
4097 
4098 
4099 /* Return true if the existing insn refs information is complete and
4100    correct. Otherwise (i.e. if there's any missing or extra refs),
4101    return the correct df_ref chain in REFS_RETURN.
4102 
4103    If ABORT_IF_FAIL, leave the refs that are verified (already in the
4104    ref chain) as DF_REF_MARKED(). If it's false, then it's a per-insn
4105    verification mode instead of the whole function, so unmark
4106    everything.
4107 
4108    If ABORT_IF_FAIL is set, this function never returns false.  */
4109 
4110 static bool
4111 df_insn_refs_verify (struct df_collection_rec *collection_rec,
4112 		     basic_block bb,
4113                      rtx_insn *insn,
4114 		     bool abort_if_fail)
4115 {
4116   bool ret1, ret2, ret3, ret4;
4117   unsigned int uid = INSN_UID (insn);
4118   struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
4119 
4120   df_insn_refs_collect (collection_rec, bb, insn_info);
4121 
4122   /* Unfortunately we cannot opt out early if one of these is not
4123      right because the marks will not get cleared.  */
4124   ret1 = df_refs_verify (&collection_rec->def_vec, DF_INSN_UID_DEFS (uid),
4125 			 abort_if_fail);
4126   ret2 = df_refs_verify (&collection_rec->use_vec, DF_INSN_UID_USES (uid),
4127 			 abort_if_fail);
4128   ret3 = df_refs_verify (&collection_rec->eq_use_vec, DF_INSN_UID_EQ_USES (uid),
4129 			 abort_if_fail);
4130   ret4 = df_mws_verify (&collection_rec->mw_vec, DF_INSN_UID_MWS (uid),
4131 		       abort_if_fail);
4132   return (ret1 && ret2 && ret3 && ret4);
4133 }
4134 
4135 
4136 /* Return true if all refs in the basic block are correct and complete.
4137    Due to df_ref_chain_verify, it will cause all refs
4138    that are verified to have DF_REF_MARK bit set.  */
4139 
4140 static bool
4141 df_bb_verify (basic_block bb)
4142 {
4143   rtx_insn *insn;
4144   struct df_scan_bb_info *bb_info = df_scan_get_bb_info (bb->index);
4145   struct df_collection_rec collection_rec;
4146 
4147   gcc_assert (bb_info);
4148 
4149   /* Scan the block, one insn at a time, from beginning to end.  */
4150   FOR_BB_INSNS_REVERSE (bb, insn)
4151     {
4152       if (!INSN_P (insn))
4153         continue;
4154       df_insn_refs_verify (&collection_rec, bb, insn, true);
4155       df_free_collection_rec (&collection_rec);
4156     }
4157 
4158   /* Do the artificial defs and uses.  */
4159   df_bb_refs_collect (&collection_rec, bb);
4160   df_refs_verify (&collection_rec.def_vec, df_get_artificial_defs (bb->index), true);
4161   df_refs_verify (&collection_rec.use_vec, df_get_artificial_uses (bb->index), true);
4162   df_free_collection_rec (&collection_rec);
4163 
4164   return true;
4165 }
4166 
4167 
4168 /* Returns true if the entry block has correct and complete df_ref set.
4169    If not it either aborts if ABORT_IF_FAIL is true or returns false.  */
4170 
4171 static bool
4172 df_entry_block_bitmap_verify (bool abort_if_fail)
4173 {
4174   bitmap_head entry_block_defs;
4175   bool is_eq;
4176 
4177   bitmap_initialize (&entry_block_defs, &df_bitmap_obstack);
4178   df_get_entry_block_def_set (&entry_block_defs);
4179 
4180   is_eq = bitmap_equal_p (&entry_block_defs, df->entry_block_defs);
4181 
4182   if (!is_eq && abort_if_fail)
4183     {
4184       fprintf (stderr, "entry_block_defs = ");
4185       df_print_regset (stderr, &entry_block_defs);
4186       fprintf (stderr, "df->entry_block_defs = ");
4187       df_print_regset (stderr, df->entry_block_defs);
4188       gcc_assert (0);
4189     }
4190 
4191   bitmap_clear (&entry_block_defs);
4192 
4193   return is_eq;
4194 }
4195 
4196 
4197 /* Returns true if the exit block has correct and complete df_ref set.
4198    If not it either aborts if ABORT_IF_FAIL is true or returns false. */
4199 
4200 static bool
4201 df_exit_block_bitmap_verify (bool abort_if_fail)
4202 {
4203   bitmap_head exit_block_uses;
4204   bool is_eq;
4205 
4206   bitmap_initialize (&exit_block_uses, &df_bitmap_obstack);
4207   df_get_exit_block_use_set (&exit_block_uses);
4208 
4209   is_eq = bitmap_equal_p (&exit_block_uses, df->exit_block_uses);
4210 
4211   if (!is_eq && abort_if_fail)
4212     {
4213       fprintf (stderr, "exit_block_uses = ");
4214       df_print_regset (stderr, &exit_block_uses);
4215       fprintf (stderr, "df->exit_block_uses = ");
4216       df_print_regset (stderr, df->exit_block_uses);
4217       gcc_assert (0);
4218     }
4219 
4220   bitmap_clear (&exit_block_uses);
4221 
4222   return is_eq;
4223 }
4224 
4225 
4226 /* Return true if df_ref information for all insns in all blocks are
4227    correct and complete.  */
4228 
4229 void
4230 df_scan_verify (void)
4231 {
4232   unsigned int i;
4233   basic_block bb;
4234   bitmap_head regular_block_artificial_uses;
4235   bitmap_head eh_block_artificial_uses;
4236 
4237   if (!df)
4238     return;
4239 
4240   /* Verification is a 4 step process. */
4241 
4242   /* (1) All of the refs are marked by going through the reg chains.  */
4243   for (i = 0; i < DF_REG_SIZE (df); i++)
4244     {
4245       gcc_assert (df_reg_chain_mark (DF_REG_DEF_CHAIN (i), i, true, false)
4246 		  == DF_REG_DEF_COUNT (i));
4247       gcc_assert (df_reg_chain_mark (DF_REG_USE_CHAIN (i), i, false, false)
4248 		  == DF_REG_USE_COUNT (i));
4249       gcc_assert (df_reg_chain_mark (DF_REG_EQ_USE_CHAIN (i), i, false, true)
4250 		  == DF_REG_EQ_USE_COUNT (i));
4251     }
4252 
4253   /* (2) There are various bitmaps whose value may change over the
4254      course of the compilation.  This step recomputes them to make
4255      sure that they have not slipped out of date.  */
4256   bitmap_initialize (&regular_block_artificial_uses, &df_bitmap_obstack);
4257   bitmap_initialize (&eh_block_artificial_uses, &df_bitmap_obstack);
4258 
4259   df_get_regular_block_artificial_uses (&regular_block_artificial_uses);
4260   df_get_eh_block_artificial_uses (&eh_block_artificial_uses);
4261 
4262   bitmap_ior_into (&eh_block_artificial_uses,
4263 		   &regular_block_artificial_uses);
4264 
4265   /* Check artificial_uses bitmaps didn't change. */
4266   gcc_assert (bitmap_equal_p (&regular_block_artificial_uses,
4267 			      &df->regular_block_artificial_uses));
4268   gcc_assert (bitmap_equal_p (&eh_block_artificial_uses,
4269 			      &df->eh_block_artificial_uses));
4270 
4271   bitmap_clear (&regular_block_artificial_uses);
4272   bitmap_clear (&eh_block_artificial_uses);
4273 
4274   /* Verify entry block and exit block. These only verify the bitmaps,
4275      the refs are verified in df_bb_verify.  */
4276   df_entry_block_bitmap_verify (true);
4277   df_exit_block_bitmap_verify (true);
4278 
4279   /* (3) All of the insns in all of the blocks are traversed and the
4280      marks are cleared both in the artificial refs attached to the
4281      blocks and the real refs inside the insns.  It is a failure to
4282      clear a mark that has not been set as this means that the ref in
4283      the block or insn was not in the reg chain.  */
4284 
4285   FOR_ALL_BB_FN (bb, cfun)
4286     df_bb_verify (bb);
4287 
4288   /* (4) See if all reg chains are traversed a second time.  This time
4289      a check is made that the marks are clear. A set mark would be a
4290      from a reg that is not in any insn or basic block.  */
4291 
4292   for (i = 0; i < DF_REG_SIZE (df); i++)
4293     {
4294       df_reg_chain_verify_unmarked (DF_REG_DEF_CHAIN (i));
4295       df_reg_chain_verify_unmarked (DF_REG_USE_CHAIN (i));
4296       df_reg_chain_verify_unmarked (DF_REG_EQ_USE_CHAIN (i));
4297     }
4298 }
4299