comparison gcc/df-problems.c @ 0:a06113de4d67

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author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Fri, 17 Jul 2009 14:47:48 +0900
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1 /* Standard problems for dataflow support routines.
2 Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
3 2008, 2009 Free Software Foundation, Inc.
4 Originally contributed by Michael P. Hayes
5 (m.hayes@elec.canterbury.ac.nz, mhayes@redhat.com)
6 Major rewrite contributed by Danny Berlin (dberlin@dberlin.org)
7 and Kenneth Zadeck (zadeck@naturalbridge.com).
8
9 This file is part of GCC.
10
11 GCC is free software; you can redistribute it and/or modify it under
12 the terms of the GNU General Public License as published by the Free
13 Software Foundation; either version 3, or (at your option) any later
14 version.
15
16 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
17 WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with GCC; see the file COPYING3. If not see
23 <http://www.gnu.org/licenses/>. */
24
25 #include "config.h"
26 #include "system.h"
27 #include "coretypes.h"
28 #include "tm.h"
29 #include "rtl.h"
30 #include "tm_p.h"
31 #include "insn-config.h"
32 #include "recog.h"
33 #include "function.h"
34 #include "regs.h"
35 #include "output.h"
36 #include "alloc-pool.h"
37 #include "flags.h"
38 #include "hard-reg-set.h"
39 #include "basic-block.h"
40 #include "sbitmap.h"
41 #include "bitmap.h"
42 #include "timevar.h"
43 #include "df.h"
44 #include "except.h"
45 #include "dce.h"
46 #include "vecprim.h"
47
48 /* Note that turning REG_DEAD_DEBUGGING on will cause
49 gcc.c-torture/unsorted/dump-noaddr.c to fail because it prints
50 addresses in the dumps. */
51 #if 0
52 #define REG_DEAD_DEBUGGING
53 #endif
54
55 #define DF_SPARSE_THRESHOLD 32
56
57 static bitmap seen_in_block = NULL;
58 static bitmap seen_in_insn = NULL;
59
60
61 /*----------------------------------------------------------------------------
62 Public functions access functions for the dataflow problems.
63 ----------------------------------------------------------------------------*/
64 /* Get the live at out set for BB no matter what problem happens to be
65 defined. This function is used by the register allocators who
66 choose different dataflow problems depending on the optimization
67 level. */
68
69 bitmap
70 df_get_live_out (basic_block bb)
71 {
72 gcc_assert (df_lr);
73
74 if (df_live)
75 return DF_LIVE_OUT (bb);
76 else
77 return DF_LR_OUT (bb);
78 }
79
80 /* Get the live at in set for BB no matter what problem happens to be
81 defined. This function is used by the register allocators who
82 choose different dataflow problems depending on the optimization
83 level. */
84
85 bitmap
86 df_get_live_in (basic_block bb)
87 {
88 gcc_assert (df_lr);
89
90 if (df_live)
91 return DF_LIVE_IN (bb);
92 else
93 return DF_LR_IN (bb);
94 }
95
96 /*----------------------------------------------------------------------------
97 Utility functions.
98 ----------------------------------------------------------------------------*/
99
100 /* Generic versions to get the void* version of the block info. Only
101 used inside the problem instance vectors. */
102
103 /* Grow the bb_info array. */
104
105 void
106 df_grow_bb_info (struct dataflow *dflow)
107 {
108 unsigned int new_size = last_basic_block + 1;
109 if (dflow->block_info_size < new_size)
110 {
111 new_size += new_size / 4;
112 dflow->block_info = XRESIZEVEC (void *, dflow->block_info, new_size);
113 memset (dflow->block_info + dflow->block_info_size, 0,
114 (new_size - dflow->block_info_size) *sizeof (void *));
115 dflow->block_info_size = new_size;
116 }
117 }
118
119 /* Dump a def-use or use-def chain for REF to FILE. */
120
121 void
122 df_chain_dump (struct df_link *link, FILE *file)
123 {
124 fprintf (file, "{ ");
125 for (; link; link = link->next)
126 {
127 fprintf (file, "%c%d(bb %d insn %d) ",
128 DF_REF_REG_DEF_P (link->ref) ? 'd' : 'u',
129 DF_REF_ID (link->ref),
130 DF_REF_BBNO (link->ref),
131 DF_REF_IS_ARTIFICIAL (link->ref) ? -1 : DF_REF_INSN_UID (link->ref));
132 }
133 fprintf (file, "}");
134 }
135
136
137 /* Print some basic block info as part of df_dump. */
138
139 void
140 df_print_bb_index (basic_block bb, FILE *file)
141 {
142 edge e;
143 edge_iterator ei;
144
145 fprintf (file, "\n( ");
146 FOR_EACH_EDGE (e, ei, bb->preds)
147 {
148 basic_block pred = e->src;
149 fprintf (file, "%d%s ", pred->index, e->flags & EDGE_EH ? "(EH)" : "");
150 }
151 fprintf (file, ")->[%d]->( ", bb->index);
152 FOR_EACH_EDGE (e, ei, bb->succs)
153 {
154 basic_block succ = e->dest;
155 fprintf (file, "%d%s ", succ->index, e->flags & EDGE_EH ? "(EH)" : "");
156 }
157 fprintf (file, ")\n");
158 }
159
160
161
162 /* Make sure that the seen_in_insn and seen_in_block sbitmaps are set
163 up correctly. */
164
165 static void
166 df_set_seen (void)
167 {
168 seen_in_block = BITMAP_ALLOC (&df_bitmap_obstack);
169 seen_in_insn = BITMAP_ALLOC (&df_bitmap_obstack);
170 }
171
172
173 static void
174 df_unset_seen (void)
175 {
176 BITMAP_FREE (seen_in_block);
177 BITMAP_FREE (seen_in_insn);
178 }
179
180
181
182 /*----------------------------------------------------------------------------
183 REACHING DEFINITIONS
184
185 Find the locations in the function where each definition site for a
186 pseudo reaches. In and out bitvectors are built for each basic
187 block. The id field in the ref is used to index into these sets.
188 See df.h for details.
189 ----------------------------------------------------------------------------*/
190
191 /* This problem plays a large number of games for the sake of
192 efficiency.
193
194 1) The order of the bits in the bitvectors. After the scanning
195 phase, all of the defs are sorted. All of the defs for the reg 0
196 are first, followed by all defs for reg 1 and so on.
197
198 2) There are two kill sets, one if the number of defs is less or
199 equal to DF_SPARSE_THRESHOLD and another if the number of defs is
200 greater.
201
202 <= : Data is built directly in the kill set.
203
204 > : One level of indirection is used to keep from generating long
205 strings of 1 bits in the kill sets. Bitvectors that are indexed
206 by the regnum are used to represent that there is a killing def
207 for the register. The confluence and transfer functions use
208 these along with the bitmap_clear_range call to remove ranges of
209 bits without actually generating a knockout vector.
210
211 The kill and sparse_kill and the dense_invalidated_by_call and
212 sparse_invalidated_by_call both play this game. */
213
214 /* Private data used to compute the solution for this problem. These
215 data structures are not accessible outside of this module. */
216 struct df_rd_problem_data
217 {
218 /* The set of defs to regs invalidated by call. */
219 bitmap sparse_invalidated_by_call;
220 /* The set of defs to regs invalidate by call for rd. */
221 bitmap dense_invalidated_by_call;
222 /* An obstack for the bitmaps we need for this problem. */
223 bitmap_obstack rd_bitmaps;
224 };
225
226 /* Set basic block info. */
227
228 static void
229 df_rd_set_bb_info (unsigned int index,
230 struct df_rd_bb_info *bb_info)
231 {
232 gcc_assert (df_rd);
233 gcc_assert (index < df_rd->block_info_size);
234 df_rd->block_info[index] = bb_info;
235 }
236
237
238 /* Free basic block info. */
239
240 static void
241 df_rd_free_bb_info (basic_block bb ATTRIBUTE_UNUSED,
242 void *vbb_info)
243 {
244 struct df_rd_bb_info *bb_info = (struct df_rd_bb_info *) vbb_info;
245 if (bb_info)
246 {
247 BITMAP_FREE (bb_info->kill);
248 BITMAP_FREE (bb_info->sparse_kill);
249 BITMAP_FREE (bb_info->gen);
250 BITMAP_FREE (bb_info->in);
251 BITMAP_FREE (bb_info->out);
252 pool_free (df_rd->block_pool, bb_info);
253 }
254 }
255
256
257 /* Allocate or reset bitmaps for DF_RD blocks. The solution bits are
258 not touched unless the block is new. */
259
260 static void
261 df_rd_alloc (bitmap all_blocks)
262 {
263 unsigned int bb_index;
264 bitmap_iterator bi;
265 struct df_rd_problem_data *problem_data;
266
267 if (!df_rd->block_pool)
268 df_rd->block_pool = create_alloc_pool ("df_rd_block pool",
269 sizeof (struct df_rd_bb_info), 50);
270
271 if (df_rd->problem_data)
272 {
273 problem_data = (struct df_rd_problem_data *) df_rd->problem_data;
274 bitmap_clear (problem_data->sparse_invalidated_by_call);
275 bitmap_clear (problem_data->dense_invalidated_by_call);
276 }
277 else
278 {
279 problem_data = XNEW (struct df_rd_problem_data);
280 df_rd->problem_data = problem_data;
281
282 bitmap_obstack_initialize (&problem_data->rd_bitmaps);
283 problem_data->sparse_invalidated_by_call
284 = BITMAP_ALLOC (&problem_data->rd_bitmaps);
285 problem_data->dense_invalidated_by_call
286 = BITMAP_ALLOC (&problem_data->rd_bitmaps);
287 }
288
289 df_grow_bb_info (df_rd);
290
291 /* Because of the clustering of all use sites for the same pseudo,
292 we have to process all of the blocks before doing the
293 analysis. */
294
295 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
296 {
297 struct df_rd_bb_info *bb_info = df_rd_get_bb_info (bb_index);
298 if (bb_info)
299 {
300 bitmap_clear (bb_info->kill);
301 bitmap_clear (bb_info->sparse_kill);
302 bitmap_clear (bb_info->gen);
303 }
304 else
305 {
306 bb_info = (struct df_rd_bb_info *) pool_alloc (df_rd->block_pool);
307 df_rd_set_bb_info (bb_index, bb_info);
308 bb_info->kill = BITMAP_ALLOC (&problem_data->rd_bitmaps);
309 bb_info->sparse_kill = BITMAP_ALLOC (&problem_data->rd_bitmaps);
310 bb_info->gen = BITMAP_ALLOC (&problem_data->rd_bitmaps);
311 bb_info->in = BITMAP_ALLOC (&problem_data->rd_bitmaps);
312 bb_info->out = BITMAP_ALLOC (&problem_data->rd_bitmaps);
313 }
314 }
315 df_rd->optional_p = true;
316 }
317
318
319 /* Process a list of DEFs for df_rd_bb_local_compute. */
320
321 static void
322 df_rd_bb_local_compute_process_def (struct df_rd_bb_info *bb_info,
323 df_ref *def_rec,
324 enum df_ref_flags top_flag)
325 {
326 while (*def_rec)
327 {
328 df_ref def = *def_rec;
329 if (top_flag == (DF_REF_FLAGS (def) & DF_REF_AT_TOP))
330 {
331 unsigned int regno = DF_REF_REGNO (def);
332 unsigned int begin = DF_DEFS_BEGIN (regno);
333 unsigned int n_defs = DF_DEFS_COUNT (regno);
334
335 if ((!(df->changeable_flags & DF_NO_HARD_REGS))
336 || (regno >= FIRST_PSEUDO_REGISTER))
337 {
338 /* Only the last def(s) for a regno in the block has any
339 effect. */
340 if (!bitmap_bit_p (seen_in_block, regno))
341 {
342 /* The first def for regno in insn gets to knock out the
343 defs from other instructions. */
344 if ((!bitmap_bit_p (seen_in_insn, regno))
345 /* If the def is to only part of the reg, it does
346 not kill the other defs that reach here. */
347 && (!(DF_REF_FLAGS (def) &
348 (DF_REF_PARTIAL | DF_REF_CONDITIONAL | DF_REF_MAY_CLOBBER))))
349 {
350 if (n_defs > DF_SPARSE_THRESHOLD)
351 {
352 bitmap_set_bit (bb_info->sparse_kill, regno);
353 bitmap_clear_range(bb_info->gen, begin, n_defs);
354 }
355 else
356 {
357 bitmap_set_range (bb_info->kill, begin, n_defs);
358 bitmap_clear_range (bb_info->gen, begin, n_defs);
359 }
360 }
361
362 bitmap_set_bit (seen_in_insn, regno);
363 /* All defs for regno in the instruction may be put into
364 the gen set. */
365 if (!(DF_REF_FLAGS (def)
366 & (DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER)))
367 bitmap_set_bit (bb_info->gen, DF_REF_ID (def));
368 }
369 }
370 }
371 def_rec++;
372 }
373 }
374
375 /* Compute local reaching def info for basic block BB. */
376
377 static void
378 df_rd_bb_local_compute (unsigned int bb_index)
379 {
380 basic_block bb = BASIC_BLOCK (bb_index);
381 struct df_rd_bb_info *bb_info = df_rd_get_bb_info (bb_index);
382 rtx insn;
383
384 bitmap_clear (seen_in_block);
385 bitmap_clear (seen_in_insn);
386
387 /* Artificials are only hard regs. */
388 if (!(df->changeable_flags & DF_NO_HARD_REGS))
389 df_rd_bb_local_compute_process_def (bb_info,
390 df_get_artificial_defs (bb_index),
391 0);
392
393 FOR_BB_INSNS_REVERSE (bb, insn)
394 {
395 unsigned int uid = INSN_UID (insn);
396
397 if (!INSN_P (insn))
398 continue;
399
400 df_rd_bb_local_compute_process_def (bb_info,
401 DF_INSN_UID_DEFS (uid), 0);
402
403 /* This complex dance with the two bitmaps is required because
404 instructions can assign twice to the same pseudo. This
405 generally happens with calls that will have one def for the
406 result and another def for the clobber. If only one vector
407 is used and the clobber goes first, the result will be
408 lost. */
409 bitmap_ior_into (seen_in_block, seen_in_insn);
410 bitmap_clear (seen_in_insn);
411 }
412
413 /* Process the artificial defs at the top of the block last since we
414 are going backwards through the block and these are logically at
415 the start. */
416 if (!(df->changeable_flags & DF_NO_HARD_REGS))
417 df_rd_bb_local_compute_process_def (bb_info,
418 df_get_artificial_defs (bb_index),
419 DF_REF_AT_TOP);
420 }
421
422
423 /* Compute local reaching def info for each basic block within BLOCKS. */
424
425 static void
426 df_rd_local_compute (bitmap all_blocks)
427 {
428 unsigned int bb_index;
429 bitmap_iterator bi;
430 unsigned int regno;
431 struct df_rd_problem_data *problem_data
432 = (struct df_rd_problem_data *) df_rd->problem_data;
433 bitmap sparse_invalidated = problem_data->sparse_invalidated_by_call;
434 bitmap dense_invalidated = problem_data->dense_invalidated_by_call;
435
436 df_set_seen ();
437
438 df_maybe_reorganize_def_refs (DF_REF_ORDER_BY_REG);
439
440 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
441 {
442 df_rd_bb_local_compute (bb_index);
443 }
444
445 /* Set up the knockout bit vectors to be applied across EH_EDGES. */
446 EXECUTE_IF_SET_IN_BITMAP (regs_invalidated_by_call_regset, 0, regno, bi)
447 {
448 if (DF_DEFS_COUNT (regno) > DF_SPARSE_THRESHOLD)
449 bitmap_set_bit (sparse_invalidated, regno);
450 else
451 bitmap_set_range (dense_invalidated,
452 DF_DEFS_BEGIN (regno),
453 DF_DEFS_COUNT (regno));
454 }
455 df_unset_seen ();
456 }
457
458
459 /* Initialize the solution bit vectors for problem. */
460
461 static void
462 df_rd_init_solution (bitmap all_blocks)
463 {
464 unsigned int bb_index;
465 bitmap_iterator bi;
466
467 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
468 {
469 struct df_rd_bb_info *bb_info = df_rd_get_bb_info (bb_index);
470
471 bitmap_copy (bb_info->out, bb_info->gen);
472 bitmap_clear (bb_info->in);
473 }
474 }
475
476 /* In of target gets or of out of source. */
477
478 static void
479 df_rd_confluence_n (edge e)
480 {
481 bitmap op1 = df_rd_get_bb_info (e->dest->index)->in;
482 bitmap op2 = df_rd_get_bb_info (e->src->index)->out;
483
484 if (e->flags & EDGE_FAKE)
485 return;
486
487 if (e->flags & EDGE_EH)
488 {
489 struct df_rd_problem_data *problem_data
490 = (struct df_rd_problem_data *) df_rd->problem_data;
491 bitmap sparse_invalidated = problem_data->sparse_invalidated_by_call;
492 bitmap dense_invalidated = problem_data->dense_invalidated_by_call;
493 bitmap_iterator bi;
494 unsigned int regno;
495 bitmap tmp = BITMAP_ALLOC (&df_bitmap_obstack);
496
497 bitmap_copy (tmp, op2);
498 bitmap_and_compl_into (tmp, dense_invalidated);
499
500 EXECUTE_IF_SET_IN_BITMAP (sparse_invalidated, 0, regno, bi)
501 {
502 bitmap_clear_range (tmp,
503 DF_DEFS_BEGIN (regno),
504 DF_DEFS_COUNT (regno));
505 }
506 bitmap_ior_into (op1, tmp);
507 BITMAP_FREE (tmp);
508 }
509 else
510 bitmap_ior_into (op1, op2);
511 }
512
513
514 /* Transfer function. */
515
516 static bool
517 df_rd_transfer_function (int bb_index)
518 {
519 struct df_rd_bb_info *bb_info = df_rd_get_bb_info (bb_index);
520 unsigned int regno;
521 bitmap_iterator bi;
522 bitmap in = bb_info->in;
523 bitmap out = bb_info->out;
524 bitmap gen = bb_info->gen;
525 bitmap kill = bb_info->kill;
526 bitmap sparse_kill = bb_info->sparse_kill;
527
528 if (bitmap_empty_p (sparse_kill))
529 return bitmap_ior_and_compl (out, gen, in, kill);
530 else
531 {
532 struct df_rd_problem_data *problem_data;
533 bool changed = false;
534 bitmap tmp;
535
536 /* Note that TMP is _not_ a temporary bitmap if we end up replacing
537 OUT with TMP. Therefore, allocate TMP in the RD bitmaps obstack. */
538 problem_data = (struct df_rd_problem_data *) df_rd->problem_data;
539 tmp = BITMAP_ALLOC (&problem_data->rd_bitmaps);
540
541 bitmap_copy (tmp, in);
542 EXECUTE_IF_SET_IN_BITMAP (sparse_kill, 0, regno, bi)
543 {
544 bitmap_clear_range (tmp,
545 DF_DEFS_BEGIN (regno),
546 DF_DEFS_COUNT (regno));
547 }
548 bitmap_and_compl_into (tmp, kill);
549 bitmap_ior_into (tmp, gen);
550 changed = !bitmap_equal_p (tmp, out);
551 if (changed)
552 {
553 BITMAP_FREE (out);
554 bb_info->out = tmp;
555 }
556 else
557 BITMAP_FREE (tmp);
558 return changed;
559 }
560 }
561
562
563 /* Free all storage associated with the problem. */
564
565 static void
566 df_rd_free (void)
567 {
568 struct df_rd_problem_data *problem_data
569 = (struct df_rd_problem_data *) df_rd->problem_data;
570
571 if (problem_data)
572 {
573 free_alloc_pool (df_rd->block_pool);
574 bitmap_obstack_release (&problem_data->rd_bitmaps);
575
576 df_rd->block_info_size = 0;
577 free (df_rd->block_info);
578 free (df_rd->problem_data);
579 }
580 free (df_rd);
581 }
582
583
584 /* Debugging info. */
585
586 static void
587 df_rd_start_dump (FILE *file)
588 {
589 struct df_rd_problem_data *problem_data
590 = (struct df_rd_problem_data *) df_rd->problem_data;
591 unsigned int m = DF_REG_SIZE(df);
592 unsigned int regno;
593
594 if (!df_rd->block_info)
595 return;
596
597 fprintf (file, ";; Reaching defs:\n\n");
598
599 fprintf (file, " sparse invalidated \t");
600 dump_bitmap (file, problem_data->sparse_invalidated_by_call);
601 fprintf (file, " dense invalidated \t");
602 dump_bitmap (file, problem_data->dense_invalidated_by_call);
603
604 for (regno = 0; regno < m; regno++)
605 if (DF_DEFS_COUNT (regno))
606 fprintf (file, "%d[%d,%d] ", regno,
607 DF_DEFS_BEGIN (regno),
608 DF_DEFS_COUNT (regno));
609 fprintf (file, "\n");
610
611 }
612
613
614 /* Debugging info at top of bb. */
615
616 static void
617 df_rd_top_dump (basic_block bb, FILE *file)
618 {
619 struct df_rd_bb_info *bb_info = df_rd_get_bb_info (bb->index);
620 if (!bb_info || !bb_info->in)
621 return;
622
623 fprintf (file, ";; rd in \t(%d)\n", (int) bitmap_count_bits (bb_info->in));
624 dump_bitmap (file, bb_info->in);
625 fprintf (file, ";; rd gen \t(%d)\n", (int) bitmap_count_bits (bb_info->gen));
626 dump_bitmap (file, bb_info->gen);
627 fprintf (file, ";; rd kill\t(%d)\n", (int) bitmap_count_bits (bb_info->kill));
628 dump_bitmap (file, bb_info->kill);
629 }
630
631
632 /* Debugging info at top of bb. */
633
634 static void
635 df_rd_bottom_dump (basic_block bb, FILE *file)
636 {
637 struct df_rd_bb_info *bb_info = df_rd_get_bb_info (bb->index);
638 if (!bb_info || !bb_info->out)
639 return;
640
641 fprintf (file, ";; rd out \t(%d)\n", (int) bitmap_count_bits (bb_info->out));
642 dump_bitmap (file, bb_info->out);
643 }
644
645 /* All of the information associated with every instance of the problem. */
646
647 static struct df_problem problem_RD =
648 {
649 DF_RD, /* Problem id. */
650 DF_FORWARD, /* Direction. */
651 df_rd_alloc, /* Allocate the problem specific data. */
652 NULL, /* Reset global information. */
653 df_rd_free_bb_info, /* Free basic block info. */
654 df_rd_local_compute, /* Local compute function. */
655 df_rd_init_solution, /* Init the solution specific data. */
656 df_worklist_dataflow, /* Worklist solver. */
657 NULL, /* Confluence operator 0. */
658 df_rd_confluence_n, /* Confluence operator n. */
659 df_rd_transfer_function, /* Transfer function. */
660 NULL, /* Finalize function. */
661 df_rd_free, /* Free all of the problem information. */
662 df_rd_free, /* Remove this problem from the stack of dataflow problems. */
663 df_rd_start_dump, /* Debugging. */
664 df_rd_top_dump, /* Debugging start block. */
665 df_rd_bottom_dump, /* Debugging end block. */
666 NULL, /* Incremental solution verify start. */
667 NULL, /* Incremental solution verify end. */
668 NULL, /* Dependent problem. */
669 TV_DF_RD, /* Timing variable. */
670 true /* Reset blocks on dropping out of blocks_to_analyze. */
671 };
672
673
674
675 /* Create a new DATAFLOW instance and add it to an existing instance
676 of DF. The returned structure is what is used to get at the
677 solution. */
678
679 void
680 df_rd_add_problem (void)
681 {
682 df_add_problem (&problem_RD);
683 }
684
685
686
687 /*----------------------------------------------------------------------------
688 LIVE REGISTERS
689
690 Find the locations in the function where any use of a pseudo can
691 reach in the backwards direction. In and out bitvectors are built
692 for each basic block. The regno is used to index into these sets.
693 See df.h for details.
694 ----------------------------------------------------------------------------*/
695
696 /* Private data used to verify the solution for this problem. */
697 struct df_lr_problem_data
698 {
699 bitmap *in;
700 bitmap *out;
701 };
702
703
704 /* Set basic block info. */
705
706 static void
707 df_lr_set_bb_info (unsigned int index,
708 struct df_lr_bb_info *bb_info)
709 {
710 gcc_assert (df_lr);
711 gcc_assert (index < df_lr->block_info_size);
712 df_lr->block_info[index] = bb_info;
713 }
714
715
716 /* Free basic block info. */
717
718 static void
719 df_lr_free_bb_info (basic_block bb ATTRIBUTE_UNUSED,
720 void *vbb_info)
721 {
722 struct df_lr_bb_info *bb_info = (struct df_lr_bb_info *) vbb_info;
723 if (bb_info)
724 {
725 BITMAP_FREE (bb_info->use);
726 BITMAP_FREE (bb_info->def);
727 BITMAP_FREE (bb_info->in);
728 BITMAP_FREE (bb_info->out);
729 pool_free (df_lr->block_pool, bb_info);
730 }
731 }
732
733
734 /* Allocate or reset bitmaps for DF_LR blocks. The solution bits are
735 not touched unless the block is new. */
736
737 static void
738 df_lr_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
739 {
740 unsigned int bb_index;
741 bitmap_iterator bi;
742
743 if (!df_lr->block_pool)
744 df_lr->block_pool = create_alloc_pool ("df_lr_block pool",
745 sizeof (struct df_lr_bb_info), 50);
746
747 df_grow_bb_info (df_lr);
748
749 EXECUTE_IF_SET_IN_BITMAP (df_lr->out_of_date_transfer_functions, 0, bb_index, bi)
750 {
751 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (bb_index);
752 if (bb_info)
753 {
754 bitmap_clear (bb_info->def);
755 bitmap_clear (bb_info->use);
756 }
757 else
758 {
759 bb_info = (struct df_lr_bb_info *) pool_alloc (df_lr->block_pool);
760 df_lr_set_bb_info (bb_index, bb_info);
761 bb_info->use = BITMAP_ALLOC (NULL);
762 bb_info->def = BITMAP_ALLOC (NULL);
763 bb_info->in = BITMAP_ALLOC (NULL);
764 bb_info->out = BITMAP_ALLOC (NULL);
765 }
766 }
767
768 df_lr->optional_p = false;
769 }
770
771
772 /* Reset the global solution for recalculation. */
773
774 static void
775 df_lr_reset (bitmap all_blocks)
776 {
777 unsigned int bb_index;
778 bitmap_iterator bi;
779
780 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
781 {
782 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (bb_index);
783 gcc_assert (bb_info);
784 bitmap_clear (bb_info->in);
785 bitmap_clear (bb_info->out);
786 }
787 }
788
789
790 /* Compute local live register info for basic block BB. */
791
792 static void
793 df_lr_bb_local_compute (unsigned int bb_index)
794 {
795 basic_block bb = BASIC_BLOCK (bb_index);
796 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (bb_index);
797 rtx insn;
798 df_ref *def_rec;
799 df_ref *use_rec;
800
801 /* Process the registers set in an exception handler. */
802 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
803 {
804 df_ref def = *def_rec;
805 if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
806 {
807 unsigned int dregno = DF_REF_REGNO (def);
808 bitmap_set_bit (bb_info->def, dregno);
809 bitmap_clear_bit (bb_info->use, dregno);
810 }
811 }
812
813 /* Process the hardware registers that are always live. */
814 for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
815 {
816 df_ref use = *use_rec;
817 /* Add use to set of uses in this BB. */
818 if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0)
819 bitmap_set_bit (bb_info->use, DF_REF_REGNO (use));
820 }
821
822 FOR_BB_INSNS_REVERSE (bb, insn)
823 {
824 unsigned int uid = INSN_UID (insn);
825
826 if (!INSN_P (insn))
827 continue;
828
829 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
830 {
831 df_ref def = *def_rec;
832 /* If the def is to only part of the reg, it does
833 not kill the other defs that reach here. */
834 if (!(DF_REF_FLAGS (def) & (DF_REF_PARTIAL | DF_REF_CONDITIONAL)))
835 {
836 unsigned int dregno = DF_REF_REGNO (def);
837 bitmap_set_bit (bb_info->def, dregno);
838 bitmap_clear_bit (bb_info->use, dregno);
839 }
840 }
841
842 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
843 {
844 df_ref use = *use_rec;
845 /* Add use to set of uses in this BB. */
846 bitmap_set_bit (bb_info->use, DF_REF_REGNO (use));
847 }
848 }
849
850 /* Process the registers set in an exception handler or the hard
851 frame pointer if this block is the target of a non local
852 goto. */
853 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
854 {
855 df_ref def = *def_rec;
856 if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
857 {
858 unsigned int dregno = DF_REF_REGNO (def);
859 bitmap_set_bit (bb_info->def, dregno);
860 bitmap_clear_bit (bb_info->use, dregno);
861 }
862 }
863
864 #ifdef EH_USES
865 /* Process the uses that are live into an exception handler. */
866 for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
867 {
868 df_ref use = *use_rec;
869 /* Add use to set of uses in this BB. */
870 if (DF_REF_FLAGS (use) & DF_REF_AT_TOP)
871 bitmap_set_bit (bb_info->use, DF_REF_REGNO (use));
872 }
873 #endif
874
875 /* If the df_live problem is not defined, such as at -O0 and -O1, we
876 still need to keep the luids up to date. This is normally done
877 in the df_live problem since this problem has a forwards
878 scan. */
879 if (!df_live)
880 df_recompute_luids (bb);
881 }
882
883
884 /* Compute local live register info for each basic block within BLOCKS. */
885
886 static void
887 df_lr_local_compute (bitmap all_blocks ATTRIBUTE_UNUSED)
888 {
889 unsigned int bb_index;
890 bitmap_iterator bi;
891
892 bitmap_clear (df->hardware_regs_used);
893
894 /* The all-important stack pointer must always be live. */
895 bitmap_set_bit (df->hardware_regs_used, STACK_POINTER_REGNUM);
896
897 /* Before reload, there are a few registers that must be forced
898 live everywhere -- which might not already be the case for
899 blocks within infinite loops. */
900 if (!reload_completed)
901 {
902 /* Any reference to any pseudo before reload is a potential
903 reference of the frame pointer. */
904 bitmap_set_bit (df->hardware_regs_used, FRAME_POINTER_REGNUM);
905
906 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
907 /* Pseudos with argument area equivalences may require
908 reloading via the argument pointer. */
909 if (fixed_regs[ARG_POINTER_REGNUM])
910 bitmap_set_bit (df->hardware_regs_used, ARG_POINTER_REGNUM);
911 #endif
912
913 /* Any constant, or pseudo with constant equivalences, may
914 require reloading from memory using the pic register. */
915 if ((unsigned) PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM
916 && fixed_regs[PIC_OFFSET_TABLE_REGNUM])
917 bitmap_set_bit (df->hardware_regs_used, PIC_OFFSET_TABLE_REGNUM);
918 }
919
920 EXECUTE_IF_SET_IN_BITMAP (df_lr->out_of_date_transfer_functions, 0, bb_index, bi)
921 {
922 if (bb_index == EXIT_BLOCK)
923 {
924 /* The exit block is special for this problem and its bits are
925 computed from thin air. */
926 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (EXIT_BLOCK);
927 bitmap_copy (bb_info->use, df->exit_block_uses);
928 }
929 else
930 df_lr_bb_local_compute (bb_index);
931 }
932
933 bitmap_clear (df_lr->out_of_date_transfer_functions);
934 }
935
936
937 /* Initialize the solution vectors. */
938
939 static void
940 df_lr_init (bitmap all_blocks)
941 {
942 unsigned int bb_index;
943 bitmap_iterator bi;
944
945 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
946 {
947 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (bb_index);
948 bitmap_copy (bb_info->in, bb_info->use);
949 bitmap_clear (bb_info->out);
950 }
951 }
952
953
954 /* Confluence function that processes infinite loops. This might be a
955 noreturn function that throws. And even if it isn't, getting the
956 unwind info right helps debugging. */
957 static void
958 df_lr_confluence_0 (basic_block bb)
959 {
960 bitmap op1 = df_lr_get_bb_info (bb->index)->out;
961 if (bb != EXIT_BLOCK_PTR)
962 bitmap_copy (op1, df->hardware_regs_used);
963 }
964
965
966 /* Confluence function that ignores fake edges. */
967
968 static void
969 df_lr_confluence_n (edge e)
970 {
971 bitmap op1 = df_lr_get_bb_info (e->src->index)->out;
972 bitmap op2 = df_lr_get_bb_info (e->dest->index)->in;
973
974 /* Call-clobbered registers die across exception and call edges. */
975 /* ??? Abnormal call edges ignored for the moment, as this gets
976 confused by sibling call edges, which crashes reg-stack. */
977 if (e->flags & EDGE_EH)
978 bitmap_ior_and_compl_into (op1, op2, regs_invalidated_by_call_regset);
979 else
980 bitmap_ior_into (op1, op2);
981
982 bitmap_ior_into (op1, df->hardware_regs_used);
983 }
984
985
986 /* Transfer function. */
987
988 static bool
989 df_lr_transfer_function (int bb_index)
990 {
991 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (bb_index);
992 bitmap in = bb_info->in;
993 bitmap out = bb_info->out;
994 bitmap use = bb_info->use;
995 bitmap def = bb_info->def;
996
997 return bitmap_ior_and_compl (in, use, out, def);
998 }
999
1000
1001 /* Run the fast dce as a side effect of building LR. */
1002
1003 static void
1004 df_lr_finalize (bitmap all_blocks)
1005 {
1006 df_lr->solutions_dirty = false;
1007 if (df->changeable_flags & DF_LR_RUN_DCE)
1008 {
1009 run_fast_df_dce ();
1010
1011 /* If dce deletes some instructions, we need to recompute the lr
1012 solution before proceeding further. The problem is that fast
1013 dce is a pessimestic dataflow algorithm. In the case where
1014 it deletes a statement S inside of a loop, the uses inside of
1015 S may not be deleted from the dataflow solution because they
1016 were carried around the loop. While it is conservatively
1017 correct to leave these extra bits, the standards of df
1018 require that we maintain the best possible (least fixed
1019 point) solution. The only way to do that is to redo the
1020 iteration from the beginning. See PR35805 for an
1021 example. */
1022 if (df_lr->solutions_dirty)
1023 {
1024 df_clear_flags (DF_LR_RUN_DCE);
1025 df_lr_alloc (all_blocks);
1026 df_lr_local_compute (all_blocks);
1027 df_worklist_dataflow (df_lr, all_blocks, df->postorder, df->n_blocks);
1028 df_lr_finalize (all_blocks);
1029 df_set_flags (DF_LR_RUN_DCE);
1030 }
1031 }
1032 }
1033
1034
1035 /* Free all storage associated with the problem. */
1036
1037 static void
1038 df_lr_free (void)
1039 {
1040 if (df_lr->block_info)
1041 {
1042 unsigned int i;
1043 for (i = 0; i < df_lr->block_info_size; i++)
1044 {
1045 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (i);
1046 if (bb_info)
1047 {
1048 BITMAP_FREE (bb_info->use);
1049 BITMAP_FREE (bb_info->def);
1050 BITMAP_FREE (bb_info->in);
1051 BITMAP_FREE (bb_info->out);
1052 }
1053 }
1054 free_alloc_pool (df_lr->block_pool);
1055
1056 df_lr->block_info_size = 0;
1057 free (df_lr->block_info);
1058 }
1059
1060 BITMAP_FREE (df_lr->out_of_date_transfer_functions);
1061 free (df_lr);
1062 }
1063
1064
1065 /* Debugging info at top of bb. */
1066
1067 static void
1068 df_lr_top_dump (basic_block bb, FILE *file)
1069 {
1070 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (bb->index);
1071 struct df_lr_problem_data *problem_data;
1072 if (!bb_info || !bb_info->in)
1073 return;
1074
1075 fprintf (file, ";; lr in \t");
1076 df_print_regset (file, bb_info->in);
1077 if (df_lr->problem_data)
1078 {
1079 problem_data = (struct df_lr_problem_data *)df_lr->problem_data;
1080 fprintf (file, ";; old in \t");
1081 df_print_regset (file, problem_data->in[bb->index]);
1082 }
1083 fprintf (file, ";; lr use \t");
1084 df_print_regset (file, bb_info->use);
1085 fprintf (file, ";; lr def \t");
1086 df_print_regset (file, bb_info->def);
1087 }
1088
1089
1090 /* Debugging info at bottom of bb. */
1091
1092 static void
1093 df_lr_bottom_dump (basic_block bb, FILE *file)
1094 {
1095 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (bb->index);
1096 struct df_lr_problem_data *problem_data;
1097 if (!bb_info || !bb_info->out)
1098 return;
1099
1100 fprintf (file, ";; lr out \t");
1101 df_print_regset (file, bb_info->out);
1102 if (df_lr->problem_data)
1103 {
1104 problem_data = (struct df_lr_problem_data *)df_lr->problem_data;
1105 fprintf (file, ";; old out \t");
1106 df_print_regset (file, problem_data->out[bb->index]);
1107 }
1108 }
1109
1110
1111 /* Build the datastructure to verify that the solution to the dataflow
1112 equations is not dirty. */
1113
1114 static void
1115 df_lr_verify_solution_start (void)
1116 {
1117 basic_block bb;
1118 struct df_lr_problem_data *problem_data;
1119 if (df_lr->solutions_dirty)
1120 {
1121 df_lr->problem_data = NULL;
1122 return;
1123 }
1124
1125 /* Set it true so that the solution is recomputed. */
1126 df_lr->solutions_dirty = true;
1127
1128 problem_data = XNEW (struct df_lr_problem_data);
1129 df_lr->problem_data = problem_data;
1130 problem_data->in = XNEWVEC (bitmap, last_basic_block);
1131 problem_data->out = XNEWVEC (bitmap, last_basic_block);
1132
1133 FOR_ALL_BB (bb)
1134 {
1135 problem_data->in[bb->index] = BITMAP_ALLOC (NULL);
1136 problem_data->out[bb->index] = BITMAP_ALLOC (NULL);
1137 bitmap_copy (problem_data->in[bb->index], DF_LR_IN (bb));
1138 bitmap_copy (problem_data->out[bb->index], DF_LR_OUT (bb));
1139 }
1140 }
1141
1142
1143 /* Compare the saved datastructure and the new solution to the dataflow
1144 equations. */
1145
1146 static void
1147 df_lr_verify_solution_end (void)
1148 {
1149 struct df_lr_problem_data *problem_data;
1150 basic_block bb;
1151
1152 if (df_lr->problem_data == NULL)
1153 return;
1154
1155 problem_data = (struct df_lr_problem_data *)df_lr->problem_data;
1156
1157 if (df_lr->solutions_dirty)
1158 /* Do not check if the solution is still dirty. See the comment
1159 in df_lr_finalize for details. */
1160 df_lr->solutions_dirty = false;
1161 else
1162 FOR_ALL_BB (bb)
1163 {
1164 if ((!bitmap_equal_p (problem_data->in[bb->index], DF_LR_IN (bb)))
1165 || (!bitmap_equal_p (problem_data->out[bb->index], DF_LR_OUT (bb))))
1166 {
1167 /*df_dump (stderr);*/
1168 gcc_unreachable ();
1169 }
1170 }
1171
1172 /* Cannot delete them immediately because you may want to dump them
1173 if the comparison fails. */
1174 FOR_ALL_BB (bb)
1175 {
1176 BITMAP_FREE (problem_data->in[bb->index]);
1177 BITMAP_FREE (problem_data->out[bb->index]);
1178 }
1179
1180 free (problem_data->in);
1181 free (problem_data->out);
1182 free (problem_data);
1183 df_lr->problem_data = NULL;
1184 }
1185
1186
1187 /* All of the information associated with every instance of the problem. */
1188
1189 static struct df_problem problem_LR =
1190 {
1191 DF_LR, /* Problem id. */
1192 DF_BACKWARD, /* Direction. */
1193 df_lr_alloc, /* Allocate the problem specific data. */
1194 df_lr_reset, /* Reset global information. */
1195 df_lr_free_bb_info, /* Free basic block info. */
1196 df_lr_local_compute, /* Local compute function. */
1197 df_lr_init, /* Init the solution specific data. */
1198 df_worklist_dataflow, /* Worklist solver. */
1199 df_lr_confluence_0, /* Confluence operator 0. */
1200 df_lr_confluence_n, /* Confluence operator n. */
1201 df_lr_transfer_function, /* Transfer function. */
1202 df_lr_finalize, /* Finalize function. */
1203 df_lr_free, /* Free all of the problem information. */
1204 NULL, /* Remove this problem from the stack of dataflow problems. */
1205 NULL, /* Debugging. */
1206 df_lr_top_dump, /* Debugging start block. */
1207 df_lr_bottom_dump, /* Debugging end block. */
1208 df_lr_verify_solution_start,/* Incremental solution verify start. */
1209 df_lr_verify_solution_end, /* Incremental solution verify end. */
1210 NULL, /* Dependent problem. */
1211 TV_DF_LR, /* Timing variable. */
1212 false /* Reset blocks on dropping out of blocks_to_analyze. */
1213 };
1214
1215
1216 /* Create a new DATAFLOW instance and add it to an existing instance
1217 of DF. The returned structure is what is used to get at the
1218 solution. */
1219
1220 void
1221 df_lr_add_problem (void)
1222 {
1223 df_add_problem (&problem_LR);
1224 /* These will be initialized when df_scan_blocks processes each
1225 block. */
1226 df_lr->out_of_date_transfer_functions = BITMAP_ALLOC (NULL);
1227 }
1228
1229
1230 /* Verify that all of the lr related info is consistent and
1231 correct. */
1232
1233 void
1234 df_lr_verify_transfer_functions (void)
1235 {
1236 basic_block bb;
1237 bitmap saved_def;
1238 bitmap saved_use;
1239 bitmap saved_adef;
1240 bitmap saved_ause;
1241 bitmap all_blocks;
1242
1243 if (!df)
1244 return;
1245
1246 saved_def = BITMAP_ALLOC (NULL);
1247 saved_use = BITMAP_ALLOC (NULL);
1248 saved_adef = BITMAP_ALLOC (NULL);
1249 saved_ause = BITMAP_ALLOC (NULL);
1250 all_blocks = BITMAP_ALLOC (NULL);
1251
1252 FOR_ALL_BB (bb)
1253 {
1254 struct df_lr_bb_info *bb_info = df_lr_get_bb_info (bb->index);
1255 bitmap_set_bit (all_blocks, bb->index);
1256
1257 if (bb_info)
1258 {
1259 /* Make a copy of the transfer functions and then compute
1260 new ones to see if the transfer functions have
1261 changed. */
1262 if (!bitmap_bit_p (df_lr->out_of_date_transfer_functions,
1263 bb->index))
1264 {
1265 bitmap_copy (saved_def, bb_info->def);
1266 bitmap_copy (saved_use, bb_info->use);
1267 bitmap_clear (bb_info->def);
1268 bitmap_clear (bb_info->use);
1269
1270 df_lr_bb_local_compute (bb->index);
1271 gcc_assert (bitmap_equal_p (saved_def, bb_info->def));
1272 gcc_assert (bitmap_equal_p (saved_use, bb_info->use));
1273 }
1274 }
1275 else
1276 {
1277 /* If we do not have basic block info, the block must be in
1278 the list of dirty blocks or else some one has added a
1279 block behind our backs. */
1280 gcc_assert (bitmap_bit_p (df_lr->out_of_date_transfer_functions,
1281 bb->index));
1282 }
1283 /* Make sure no one created a block without following
1284 procedures. */
1285 gcc_assert (df_scan_get_bb_info (bb->index));
1286 }
1287
1288 /* Make sure there are no dirty bits in blocks that have been deleted. */
1289 gcc_assert (!bitmap_intersect_compl_p (df_lr->out_of_date_transfer_functions,
1290 all_blocks));
1291
1292 BITMAP_FREE (saved_def);
1293 BITMAP_FREE (saved_use);
1294 BITMAP_FREE (saved_adef);
1295 BITMAP_FREE (saved_ause);
1296 BITMAP_FREE (all_blocks);
1297 }
1298
1299
1300
1301 /*----------------------------------------------------------------------------
1302 LIVE AND MUST-INITIALIZED REGISTERS.
1303
1304 This problem first computes the IN and OUT bitvectors for the
1305 must-initialized registers problems, which is a forward problem.
1306 It gives the set of registers for which we MUST have an available
1307 definition on any path from the entry block to the entry/exit of
1308 a basic block. Sets generate a definition, while clobbers kill
1309 a definition.
1310
1311 In and out bitvectors are built for each basic block and are indexed by
1312 regnum (see df.h for details). In and out bitvectors in struct
1313 df_live_bb_info actually refers to the must-initialized problem;
1314
1315 Then, the in and out sets for the LIVE problem itself are computed.
1316 These are the logical AND of the IN and OUT sets from the LR problem
1317 and the must-initialized problem.
1318 ----------------------------------------------------------------------------*/
1319
1320 /* Private data used to verify the solution for this problem. */
1321 struct df_live_problem_data
1322 {
1323 bitmap *in;
1324 bitmap *out;
1325 };
1326
1327 /* Scratch var used by transfer functions. This is used to implement
1328 an optimization to reduce the amount of space used to compute the
1329 combined lr and live analysis. */
1330 static bitmap df_live_scratch;
1331
1332 /* Set basic block info. */
1333
1334 static void
1335 df_live_set_bb_info (unsigned int index,
1336 struct df_live_bb_info *bb_info)
1337 {
1338 gcc_assert (df_live);
1339 gcc_assert (index < df_live->block_info_size);
1340 df_live->block_info[index] = bb_info;
1341 }
1342
1343
1344 /* Free basic block info. */
1345
1346 static void
1347 df_live_free_bb_info (basic_block bb ATTRIBUTE_UNUSED,
1348 void *vbb_info)
1349 {
1350 struct df_live_bb_info *bb_info = (struct df_live_bb_info *) vbb_info;
1351 if (bb_info)
1352 {
1353 BITMAP_FREE (bb_info->gen);
1354 BITMAP_FREE (bb_info->kill);
1355 BITMAP_FREE (bb_info->in);
1356 BITMAP_FREE (bb_info->out);
1357 pool_free (df_live->block_pool, bb_info);
1358 }
1359 }
1360
1361
1362 /* Allocate or reset bitmaps for DF_LIVE blocks. The solution bits are
1363 not touched unless the block is new. */
1364
1365 static void
1366 df_live_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
1367 {
1368 unsigned int bb_index;
1369 bitmap_iterator bi;
1370
1371 if (!df_live->block_pool)
1372 df_live->block_pool = create_alloc_pool ("df_live_block pool",
1373 sizeof (struct df_live_bb_info), 100);
1374 if (!df_live_scratch)
1375 df_live_scratch = BITMAP_ALLOC (NULL);
1376
1377 df_grow_bb_info (df_live);
1378
1379 EXECUTE_IF_SET_IN_BITMAP (df_live->out_of_date_transfer_functions, 0, bb_index, bi)
1380 {
1381 struct df_live_bb_info *bb_info = df_live_get_bb_info (bb_index);
1382 if (bb_info)
1383 {
1384 bitmap_clear (bb_info->kill);
1385 bitmap_clear (bb_info->gen);
1386 }
1387 else
1388 {
1389 bb_info = (struct df_live_bb_info *) pool_alloc (df_live->block_pool);
1390 df_live_set_bb_info (bb_index, bb_info);
1391 bb_info->kill = BITMAP_ALLOC (NULL);
1392 bb_info->gen = BITMAP_ALLOC (NULL);
1393 bb_info->in = BITMAP_ALLOC (NULL);
1394 bb_info->out = BITMAP_ALLOC (NULL);
1395 }
1396 }
1397 df_live->optional_p = (optimize <= 1);
1398 }
1399
1400
1401 /* Reset the global solution for recalculation. */
1402
1403 static void
1404 df_live_reset (bitmap all_blocks)
1405 {
1406 unsigned int bb_index;
1407 bitmap_iterator bi;
1408
1409 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
1410 {
1411 struct df_live_bb_info *bb_info = df_live_get_bb_info (bb_index);
1412 gcc_assert (bb_info);
1413 bitmap_clear (bb_info->in);
1414 bitmap_clear (bb_info->out);
1415 }
1416 }
1417
1418
1419 /* Compute local uninitialized register info for basic block BB. */
1420
1421 static void
1422 df_live_bb_local_compute (unsigned int bb_index)
1423 {
1424 basic_block bb = BASIC_BLOCK (bb_index);
1425 struct df_live_bb_info *bb_info = df_live_get_bb_info (bb_index);
1426 rtx insn;
1427 df_ref *def_rec;
1428 int luid = 0;
1429
1430 FOR_BB_INSNS (bb, insn)
1431 {
1432 unsigned int uid = INSN_UID (insn);
1433 struct df_insn_info *insn_info = DF_INSN_UID_GET (uid);
1434
1435 /* Inserting labels does not always trigger the incremental
1436 rescanning. */
1437 if (!insn_info)
1438 {
1439 gcc_assert (!INSN_P (insn));
1440 insn_info = df_insn_create_insn_record (insn);
1441 }
1442
1443 DF_INSN_INFO_LUID (insn_info) = luid;
1444 if (!INSN_P (insn))
1445 continue;
1446
1447 luid++;
1448 for (def_rec = DF_INSN_INFO_DEFS (insn_info); *def_rec; def_rec++)
1449 {
1450 df_ref def = *def_rec;
1451 unsigned int regno = DF_REF_REGNO (def);
1452
1453 if (DF_REF_FLAGS_IS_SET (def,
1454 DF_REF_PARTIAL | DF_REF_CONDITIONAL))
1455 /* All partial or conditional def
1456 seen are included in the gen set. */
1457 bitmap_set_bit (bb_info->gen, regno);
1458 else if (DF_REF_FLAGS_IS_SET (def, DF_REF_MUST_CLOBBER))
1459 /* Only must clobbers for the entire reg destroy the
1460 value. */
1461 bitmap_set_bit (bb_info->kill, regno);
1462 else if (! DF_REF_FLAGS_IS_SET (def, DF_REF_MAY_CLOBBER))
1463 bitmap_set_bit (bb_info->gen, regno);
1464 }
1465 }
1466
1467 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
1468 {
1469 df_ref def = *def_rec;
1470 bitmap_set_bit (bb_info->gen, DF_REF_REGNO (def));
1471 }
1472 }
1473
1474
1475 /* Compute local uninitialized register info. */
1476
1477 static void
1478 df_live_local_compute (bitmap all_blocks ATTRIBUTE_UNUSED)
1479 {
1480 unsigned int bb_index;
1481 bitmap_iterator bi;
1482
1483 df_grow_insn_info ();
1484
1485 EXECUTE_IF_SET_IN_BITMAP (df_live->out_of_date_transfer_functions,
1486 0, bb_index, bi)
1487 {
1488 df_live_bb_local_compute (bb_index);
1489 }
1490
1491 bitmap_clear (df_live->out_of_date_transfer_functions);
1492 }
1493
1494
1495 /* Initialize the solution vectors. */
1496
1497 static void
1498 df_live_init (bitmap all_blocks)
1499 {
1500 unsigned int bb_index;
1501 bitmap_iterator bi;
1502
1503 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
1504 {
1505 struct df_live_bb_info *bb_info = df_live_get_bb_info (bb_index);
1506 struct df_lr_bb_info *bb_lr_info = df_lr_get_bb_info (bb_index);
1507
1508 /* No register may reach a location where it is not used. Thus
1509 we trim the rr result to the places where it is used. */
1510 bitmap_and (bb_info->out, bb_info->gen, bb_lr_info->out);
1511 bitmap_clear (bb_info->in);
1512 }
1513 }
1514
1515 /* Forward confluence function that ignores fake edges. */
1516
1517 static void
1518 df_live_confluence_n (edge e)
1519 {
1520 bitmap op1 = df_live_get_bb_info (e->dest->index)->in;
1521 bitmap op2 = df_live_get_bb_info (e->src->index)->out;
1522
1523 if (e->flags & EDGE_FAKE)
1524 return;
1525
1526 bitmap_ior_into (op1, op2);
1527 }
1528
1529
1530 /* Transfer function for the forwards must-initialized problem. */
1531
1532 static bool
1533 df_live_transfer_function (int bb_index)
1534 {
1535 struct df_live_bb_info *bb_info = df_live_get_bb_info (bb_index);
1536 struct df_lr_bb_info *bb_lr_info = df_lr_get_bb_info (bb_index);
1537 bitmap in = bb_info->in;
1538 bitmap out = bb_info->out;
1539 bitmap gen = bb_info->gen;
1540 bitmap kill = bb_info->kill;
1541
1542 /* We need to use a scratch set here so that the value returned from
1543 this function invocation properly reflects if the sets changed in
1544 a significant way; i.e. not just because the lr set was anded
1545 in. */
1546 bitmap_and (df_live_scratch, gen, bb_lr_info->out);
1547 /* No register may reach a location where it is not used. Thus
1548 we trim the rr result to the places where it is used. */
1549 bitmap_and_into (in, bb_lr_info->in);
1550
1551 return bitmap_ior_and_compl (out, df_live_scratch, in, kill);
1552 }
1553
1554
1555 /* And the LR info with the must-initialized registers, to produce the LIVE info. */
1556
1557 static void
1558 df_live_finalize (bitmap all_blocks)
1559 {
1560
1561 if (df_live->solutions_dirty)
1562 {
1563 bitmap_iterator bi;
1564 unsigned int bb_index;
1565
1566 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
1567 {
1568 struct df_lr_bb_info *bb_lr_info = df_lr_get_bb_info (bb_index);
1569 struct df_live_bb_info *bb_live_info = df_live_get_bb_info (bb_index);
1570
1571 /* No register may reach a location where it is not used. Thus
1572 we trim the rr result to the places where it is used. */
1573 bitmap_and_into (bb_live_info->in, bb_lr_info->in);
1574 bitmap_and_into (bb_live_info->out, bb_lr_info->out);
1575 }
1576
1577 df_live->solutions_dirty = false;
1578 }
1579 }
1580
1581
1582 /* Free all storage associated with the problem. */
1583
1584 static void
1585 df_live_free (void)
1586 {
1587 if (df_live->block_info)
1588 {
1589 unsigned int i;
1590
1591 for (i = 0; i < df_live->block_info_size; i++)
1592 {
1593 struct df_live_bb_info *bb_info = df_live_get_bb_info (i);
1594 if (bb_info)
1595 {
1596 BITMAP_FREE (bb_info->gen);
1597 BITMAP_FREE (bb_info->kill);
1598 BITMAP_FREE (bb_info->in);
1599 BITMAP_FREE (bb_info->out);
1600 }
1601 }
1602
1603 free_alloc_pool (df_live->block_pool);
1604 df_live->block_info_size = 0;
1605 free (df_live->block_info);
1606
1607 if (df_live_scratch)
1608 BITMAP_FREE (df_live_scratch);
1609 }
1610 BITMAP_FREE (df_live->out_of_date_transfer_functions);
1611 free (df_live);
1612 }
1613
1614
1615 /* Debugging info at top of bb. */
1616
1617 static void
1618 df_live_top_dump (basic_block bb, FILE *file)
1619 {
1620 struct df_live_bb_info *bb_info = df_live_get_bb_info (bb->index);
1621 struct df_live_problem_data *problem_data;
1622
1623 if (!bb_info || !bb_info->in)
1624 return;
1625
1626 fprintf (file, ";; live in \t");
1627 df_print_regset (file, bb_info->in);
1628 if (df_live->problem_data)
1629 {
1630 problem_data = (struct df_live_problem_data *)df_live->problem_data;
1631 fprintf (file, ";; old in \t");
1632 df_print_regset (file, problem_data->in[bb->index]);
1633 }
1634 fprintf (file, ";; live gen \t");
1635 df_print_regset (file, bb_info->gen);
1636 fprintf (file, ";; live kill\t");
1637 df_print_regset (file, bb_info->kill);
1638 }
1639
1640
1641 /* Debugging info at bottom of bb. */
1642
1643 static void
1644 df_live_bottom_dump (basic_block bb, FILE *file)
1645 {
1646 struct df_live_bb_info *bb_info = df_live_get_bb_info (bb->index);
1647 struct df_live_problem_data *problem_data;
1648
1649 if (!bb_info || !bb_info->out)
1650 return;
1651
1652 fprintf (file, ";; live out \t");
1653 df_print_regset (file, bb_info->out);
1654 if (df_live->problem_data)
1655 {
1656 problem_data = (struct df_live_problem_data *)df_live->problem_data;
1657 fprintf (file, ";; old out \t");
1658 df_print_regset (file, problem_data->out[bb->index]);
1659 }
1660 }
1661
1662
1663 /* Build the datastructure to verify that the solution to the dataflow
1664 equations is not dirty. */
1665
1666 static void
1667 df_live_verify_solution_start (void)
1668 {
1669 basic_block bb;
1670 struct df_live_problem_data *problem_data;
1671 if (df_live->solutions_dirty)
1672 {
1673 df_live->problem_data = NULL;
1674 return;
1675 }
1676
1677 /* Set it true so that the solution is recomputed. */
1678 df_live->solutions_dirty = true;
1679
1680 problem_data = XNEW (struct df_live_problem_data);
1681 df_live->problem_data = problem_data;
1682 problem_data->in = XNEWVEC (bitmap, last_basic_block);
1683 problem_data->out = XNEWVEC (bitmap, last_basic_block);
1684
1685 FOR_ALL_BB (bb)
1686 {
1687 problem_data->in[bb->index] = BITMAP_ALLOC (NULL);
1688 problem_data->out[bb->index] = BITMAP_ALLOC (NULL);
1689 bitmap_copy (problem_data->in[bb->index], DF_LIVE_IN (bb));
1690 bitmap_copy (problem_data->out[bb->index], DF_LIVE_OUT (bb));
1691 }
1692 }
1693
1694
1695 /* Compare the saved datastructure and the new solution to the dataflow
1696 equations. */
1697
1698 static void
1699 df_live_verify_solution_end (void)
1700 {
1701 struct df_live_problem_data *problem_data;
1702 basic_block bb;
1703
1704 if (df_live->problem_data == NULL)
1705 return;
1706
1707 problem_data = (struct df_live_problem_data *)df_live->problem_data;
1708
1709 FOR_ALL_BB (bb)
1710 {
1711 if ((!bitmap_equal_p (problem_data->in[bb->index], DF_LIVE_IN (bb)))
1712 || (!bitmap_equal_p (problem_data->out[bb->index], DF_LIVE_OUT (bb))))
1713 {
1714 /*df_dump (stderr);*/
1715 gcc_unreachable ();
1716 }
1717 }
1718
1719 /* Cannot delete them immediately because you may want to dump them
1720 if the comparison fails. */
1721 FOR_ALL_BB (bb)
1722 {
1723 BITMAP_FREE (problem_data->in[bb->index]);
1724 BITMAP_FREE (problem_data->out[bb->index]);
1725 }
1726
1727 free (problem_data->in);
1728 free (problem_data->out);
1729 free (problem_data);
1730 df_live->problem_data = NULL;
1731 }
1732
1733
1734 /* All of the information associated with every instance of the problem. */
1735
1736 static struct df_problem problem_LIVE =
1737 {
1738 DF_LIVE, /* Problem id. */
1739 DF_FORWARD, /* Direction. */
1740 df_live_alloc, /* Allocate the problem specific data. */
1741 df_live_reset, /* Reset global information. */
1742 df_live_free_bb_info, /* Free basic block info. */
1743 df_live_local_compute, /* Local compute function. */
1744 df_live_init, /* Init the solution specific data. */
1745 df_worklist_dataflow, /* Worklist solver. */
1746 NULL, /* Confluence operator 0. */
1747 df_live_confluence_n, /* Confluence operator n. */
1748 df_live_transfer_function, /* Transfer function. */
1749 df_live_finalize, /* Finalize function. */
1750 df_live_free, /* Free all of the problem information. */
1751 df_live_free, /* Remove this problem from the stack of dataflow problems. */
1752 NULL, /* Debugging. */
1753 df_live_top_dump, /* Debugging start block. */
1754 df_live_bottom_dump, /* Debugging end block. */
1755 df_live_verify_solution_start,/* Incremental solution verify start. */
1756 df_live_verify_solution_end, /* Incremental solution verify end. */
1757 &problem_LR, /* Dependent problem. */
1758 TV_DF_LIVE, /* Timing variable. */
1759 false /* Reset blocks on dropping out of blocks_to_analyze. */
1760 };
1761
1762
1763 /* Create a new DATAFLOW instance and add it to an existing instance
1764 of DF. The returned structure is what is used to get at the
1765 solution. */
1766
1767 void
1768 df_live_add_problem (void)
1769 {
1770 df_add_problem (&problem_LIVE);
1771 /* These will be initialized when df_scan_blocks processes each
1772 block. */
1773 df_live->out_of_date_transfer_functions = BITMAP_ALLOC (NULL);
1774 }
1775
1776
1777 /* Set all of the blocks as dirty. This needs to be done if this
1778 problem is added after all of the insns have been scanned. */
1779
1780 void
1781 df_live_set_all_dirty (void)
1782 {
1783 basic_block bb;
1784 FOR_ALL_BB (bb)
1785 bitmap_set_bit (df_live->out_of_date_transfer_functions,
1786 bb->index);
1787 }
1788
1789
1790 /* Verify that all of the lr related info is consistent and
1791 correct. */
1792
1793 void
1794 df_live_verify_transfer_functions (void)
1795 {
1796 basic_block bb;
1797 bitmap saved_gen;
1798 bitmap saved_kill;
1799 bitmap all_blocks;
1800
1801 if (!df)
1802 return;
1803
1804 saved_gen = BITMAP_ALLOC (NULL);
1805 saved_kill = BITMAP_ALLOC (NULL);
1806 all_blocks = BITMAP_ALLOC (NULL);
1807
1808 df_grow_insn_info ();
1809
1810 FOR_ALL_BB (bb)
1811 {
1812 struct df_live_bb_info *bb_info = df_live_get_bb_info (bb->index);
1813 bitmap_set_bit (all_blocks, bb->index);
1814
1815 if (bb_info)
1816 {
1817 /* Make a copy of the transfer functions and then compute
1818 new ones to see if the transfer functions have
1819 changed. */
1820 if (!bitmap_bit_p (df_live->out_of_date_transfer_functions,
1821 bb->index))
1822 {
1823 bitmap_copy (saved_gen, bb_info->gen);
1824 bitmap_copy (saved_kill, bb_info->kill);
1825 bitmap_clear (bb_info->gen);
1826 bitmap_clear (bb_info->kill);
1827
1828 df_live_bb_local_compute (bb->index);
1829 gcc_assert (bitmap_equal_p (saved_gen, bb_info->gen));
1830 gcc_assert (bitmap_equal_p (saved_kill, bb_info->kill));
1831 }
1832 }
1833 else
1834 {
1835 /* If we do not have basic block info, the block must be in
1836 the list of dirty blocks or else some one has added a
1837 block behind our backs. */
1838 gcc_assert (bitmap_bit_p (df_live->out_of_date_transfer_functions,
1839 bb->index));
1840 }
1841 /* Make sure no one created a block without following
1842 procedures. */
1843 gcc_assert (df_scan_get_bb_info (bb->index));
1844 }
1845
1846 /* Make sure there are no dirty bits in blocks that have been deleted. */
1847 gcc_assert (!bitmap_intersect_compl_p (df_live->out_of_date_transfer_functions,
1848 all_blocks));
1849 BITMAP_FREE (saved_gen);
1850 BITMAP_FREE (saved_kill);
1851 BITMAP_FREE (all_blocks);
1852 }
1853
1854 /*----------------------------------------------------------------------------
1855 CREATE DEF_USE (DU) and / or USE_DEF (UD) CHAINS
1856
1857 Link either the defs to the uses and / or the uses to the defs.
1858
1859 These problems are set up like the other dataflow problems so that
1860 they nicely fit into the framework. They are much simpler and only
1861 involve a single traversal of instructions and an examination of
1862 the reaching defs information (the dependent problem).
1863 ----------------------------------------------------------------------------*/
1864
1865 #define df_chain_problem_p(FLAG) (((enum df_chain_flags)df_chain->local_flags)&(FLAG))
1866
1867 /* Create a du or ud chain from SRC to DST and link it into SRC. */
1868
1869 struct df_link *
1870 df_chain_create (df_ref src, df_ref dst)
1871 {
1872 struct df_link *head = DF_REF_CHAIN (src);
1873 struct df_link *link = (struct df_link *) pool_alloc (df_chain->block_pool);
1874
1875 DF_REF_CHAIN (src) = link;
1876 link->next = head;
1877 link->ref = dst;
1878 return link;
1879 }
1880
1881
1882 /* Delete any du or ud chains that start at REF and point to
1883 TARGET. */
1884 static void
1885 df_chain_unlink_1 (df_ref ref, df_ref target)
1886 {
1887 struct df_link *chain = DF_REF_CHAIN (ref);
1888 struct df_link *prev = NULL;
1889
1890 while (chain)
1891 {
1892 if (chain->ref == target)
1893 {
1894 if (prev)
1895 prev->next = chain->next;
1896 else
1897 DF_REF_CHAIN (ref) = chain->next;
1898 pool_free (df_chain->block_pool, chain);
1899 return;
1900 }
1901 prev = chain;
1902 chain = chain->next;
1903 }
1904 }
1905
1906
1907 /* Delete a du or ud chain that leave or point to REF. */
1908
1909 void
1910 df_chain_unlink (df_ref ref)
1911 {
1912 struct df_link *chain = DF_REF_CHAIN (ref);
1913 while (chain)
1914 {
1915 struct df_link *next = chain->next;
1916 /* Delete the other side if it exists. */
1917 df_chain_unlink_1 (chain->ref, ref);
1918 pool_free (df_chain->block_pool, chain);
1919 chain = next;
1920 }
1921 DF_REF_CHAIN (ref) = NULL;
1922 }
1923
1924
1925 /* Copy the du or ud chain starting at FROM_REF and attach it to
1926 TO_REF. */
1927
1928 void
1929 df_chain_copy (df_ref to_ref,
1930 struct df_link *from_ref)
1931 {
1932 while (from_ref)
1933 {
1934 df_chain_create (to_ref, from_ref->ref);
1935 from_ref = from_ref->next;
1936 }
1937 }
1938
1939
1940 /* Remove this problem from the stack of dataflow problems. */
1941
1942 static void
1943 df_chain_remove_problem (void)
1944 {
1945 bitmap_iterator bi;
1946 unsigned int bb_index;
1947
1948 /* Wholesale destruction of the old chains. */
1949 if (df_chain->block_pool)
1950 free_alloc_pool (df_chain->block_pool);
1951
1952 EXECUTE_IF_SET_IN_BITMAP (df_chain->out_of_date_transfer_functions, 0, bb_index, bi)
1953 {
1954 rtx insn;
1955 df_ref *def_rec;
1956 df_ref *use_rec;
1957 basic_block bb = BASIC_BLOCK (bb_index);
1958
1959 if (df_chain_problem_p (DF_DU_CHAIN))
1960 for (def_rec = df_get_artificial_defs (bb->index); *def_rec; def_rec++)
1961 DF_REF_CHAIN (*def_rec) = NULL;
1962 if (df_chain_problem_p (DF_UD_CHAIN))
1963 for (use_rec = df_get_artificial_uses (bb->index); *use_rec; use_rec++)
1964 DF_REF_CHAIN (*use_rec) = NULL;
1965
1966 FOR_BB_INSNS (bb, insn)
1967 {
1968 unsigned int uid = INSN_UID (insn);
1969
1970 if (INSN_P (insn))
1971 {
1972 if (df_chain_problem_p (DF_DU_CHAIN))
1973 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
1974 DF_REF_CHAIN (*def_rec) = NULL;
1975 if (df_chain_problem_p (DF_UD_CHAIN))
1976 {
1977 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
1978 DF_REF_CHAIN (*use_rec) = NULL;
1979 for (use_rec = DF_INSN_UID_EQ_USES (uid); *use_rec; use_rec++)
1980 DF_REF_CHAIN (*use_rec) = NULL;
1981 }
1982 }
1983 }
1984 }
1985
1986 bitmap_clear (df_chain->out_of_date_transfer_functions);
1987 df_chain->block_pool = NULL;
1988 }
1989
1990
1991 /* Remove the chain problem completely. */
1992
1993 static void
1994 df_chain_fully_remove_problem (void)
1995 {
1996 df_chain_remove_problem ();
1997 BITMAP_FREE (df_chain->out_of_date_transfer_functions);
1998 free (df_chain);
1999 }
2000
2001
2002 /* Create def-use or use-def chains. */
2003
2004 static void
2005 df_chain_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
2006 {
2007 df_chain_remove_problem ();
2008 df_chain->block_pool = create_alloc_pool ("df_chain_block pool",
2009 sizeof (struct df_link), 50);
2010 df_chain->optional_p = true;
2011 }
2012
2013
2014 /* Reset all of the chains when the set of basic blocks changes. */
2015
2016 static void
2017 df_chain_reset (bitmap blocks_to_clear ATTRIBUTE_UNUSED)
2018 {
2019 df_chain_remove_problem ();
2020 }
2021
2022
2023 /* Create the chains for a list of USEs. */
2024
2025 static void
2026 df_chain_create_bb_process_use (bitmap local_rd,
2027 df_ref *use_rec,
2028 enum df_ref_flags top_flag)
2029 {
2030 bitmap_iterator bi;
2031 unsigned int def_index;
2032
2033 while (*use_rec)
2034 {
2035 df_ref use = *use_rec;
2036 unsigned int uregno = DF_REF_REGNO (use);
2037 if ((!(df->changeable_flags & DF_NO_HARD_REGS))
2038 || (uregno >= FIRST_PSEUDO_REGISTER))
2039 {
2040 /* Do not want to go through this for an uninitialized var. */
2041 int count = DF_DEFS_COUNT (uregno);
2042 if (count)
2043 {
2044 if (top_flag == (DF_REF_FLAGS (use) & DF_REF_AT_TOP))
2045 {
2046 unsigned int first_index = DF_DEFS_BEGIN (uregno);
2047 unsigned int last_index = first_index + count - 1;
2048
2049 EXECUTE_IF_SET_IN_BITMAP (local_rd, first_index, def_index, bi)
2050 {
2051 df_ref def;
2052 if (def_index > last_index)
2053 break;
2054
2055 def = DF_DEFS_GET (def_index);
2056 if (df_chain_problem_p (DF_DU_CHAIN))
2057 df_chain_create (def, use);
2058 if (df_chain_problem_p (DF_UD_CHAIN))
2059 df_chain_create (use, def);
2060 }
2061 }
2062 }
2063 }
2064
2065 use_rec++;
2066 }
2067 }
2068
2069
2070 /* Create chains from reaching defs bitmaps for basic block BB. */
2071
2072 static void
2073 df_chain_create_bb (unsigned int bb_index)
2074 {
2075 basic_block bb = BASIC_BLOCK (bb_index);
2076 struct df_rd_bb_info *bb_info = df_rd_get_bb_info (bb_index);
2077 rtx insn;
2078 bitmap cpy = BITMAP_ALLOC (NULL);
2079 df_ref *def_rec;
2080
2081 bitmap_copy (cpy, bb_info->in);
2082 bitmap_set_bit (df_chain->out_of_date_transfer_functions, bb_index);
2083
2084 /* Since we are going forwards, process the artificial uses first
2085 then the artificial defs second. */
2086
2087 #ifdef EH_USES
2088 /* Create the chains for the artificial uses from the EH_USES at the
2089 beginning of the block. */
2090
2091 /* Artificials are only hard regs. */
2092 if (!(df->changeable_flags & DF_NO_HARD_REGS))
2093 df_chain_create_bb_process_use (cpy,
2094 df_get_artificial_uses (bb->index),
2095 DF_REF_AT_TOP);
2096 #endif
2097
2098 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
2099 {
2100 df_ref def = *def_rec;
2101 if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
2102 {
2103 unsigned int dregno = DF_REF_REGNO (def);
2104 if (!(DF_REF_FLAGS (def) & (DF_REF_PARTIAL | DF_REF_CONDITIONAL)))
2105 bitmap_clear_range (cpy,
2106 DF_DEFS_BEGIN (dregno),
2107 DF_DEFS_COUNT (dregno));
2108 bitmap_set_bit (cpy, DF_REF_ID (def));
2109 }
2110 }
2111
2112 /* Process the regular instructions next. */
2113 FOR_BB_INSNS (bb, insn)
2114 {
2115 df_ref *def_rec;
2116 unsigned int uid = INSN_UID (insn);
2117
2118 if (!INSN_P (insn))
2119 continue;
2120
2121 /* Now scan the uses and link them up with the defs that remain
2122 in the cpy vector. */
2123
2124 df_chain_create_bb_process_use (cpy, DF_INSN_UID_USES (uid), 0);
2125
2126 if (df->changeable_flags & DF_EQ_NOTES)
2127 df_chain_create_bb_process_use (cpy, DF_INSN_UID_EQ_USES (uid), 0);
2128
2129
2130 /* Since we are going forwards, process the defs second. This
2131 pass only changes the bits in cpy. */
2132 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
2133 {
2134 df_ref def = *def_rec;
2135 unsigned int dregno = DF_REF_REGNO (def);
2136 if ((!(df->changeable_flags & DF_NO_HARD_REGS))
2137 || (dregno >= FIRST_PSEUDO_REGISTER))
2138 {
2139 if (!(DF_REF_FLAGS (def) & (DF_REF_PARTIAL | DF_REF_CONDITIONAL)))
2140 bitmap_clear_range (cpy,
2141 DF_DEFS_BEGIN (dregno),
2142 DF_DEFS_COUNT (dregno));
2143 if (!(DF_REF_FLAGS (def)
2144 & (DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER)))
2145 bitmap_set_bit (cpy, DF_REF_ID (def));
2146 }
2147 }
2148 }
2149
2150 /* Create the chains for the artificial uses of the hard registers
2151 at the end of the block. */
2152 if (!(df->changeable_flags & DF_NO_HARD_REGS))
2153 df_chain_create_bb_process_use (cpy,
2154 df_get_artificial_uses (bb->index),
2155 0);
2156
2157 BITMAP_FREE (cpy);
2158 }
2159
2160 /* Create def-use chains from reaching use bitmaps for basic blocks
2161 in BLOCKS. */
2162
2163 static void
2164 df_chain_finalize (bitmap all_blocks)
2165 {
2166 unsigned int bb_index;
2167 bitmap_iterator bi;
2168
2169 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
2170 {
2171 df_chain_create_bb (bb_index);
2172 }
2173 }
2174
2175
2176 /* Free all storage associated with the problem. */
2177
2178 static void
2179 df_chain_free (void)
2180 {
2181 free_alloc_pool (df_chain->block_pool);
2182 BITMAP_FREE (df_chain->out_of_date_transfer_functions);
2183 free (df_chain);
2184 }
2185
2186
2187 /* Debugging info. */
2188
2189 static void
2190 df_chain_top_dump (basic_block bb, FILE *file)
2191 {
2192 if (df_chain_problem_p (DF_DU_CHAIN))
2193 {
2194 rtx insn;
2195 df_ref *def_rec = df_get_artificial_defs (bb->index);
2196 if (*def_rec)
2197 {
2198
2199 fprintf (file, ";; DU chains for artificial defs\n");
2200 while (*def_rec)
2201 {
2202 df_ref def = *def_rec;
2203 fprintf (file, ";; reg %d ", DF_REF_REGNO (def));
2204 df_chain_dump (DF_REF_CHAIN (def), file);
2205 fprintf (file, "\n");
2206 def_rec++;
2207 }
2208 }
2209
2210 FOR_BB_INSNS (bb, insn)
2211 {
2212 if (INSN_P (insn))
2213 {
2214 struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
2215 def_rec = DF_INSN_INFO_DEFS (insn_info);
2216 if (*def_rec)
2217 {
2218 fprintf (file, ";; DU chains for insn luid %d uid %d\n",
2219 DF_INSN_INFO_LUID (insn_info), INSN_UID (insn));
2220
2221 while (*def_rec)
2222 {
2223 df_ref def = *def_rec;
2224 fprintf (file, ";; reg %d ", DF_REF_REGNO (def));
2225 if (DF_REF_FLAGS (def) & DF_REF_READ_WRITE)
2226 fprintf (file, "read/write ");
2227 df_chain_dump (DF_REF_CHAIN (def), file);
2228 fprintf (file, "\n");
2229 def_rec++;
2230 }
2231 }
2232 }
2233 }
2234 }
2235 }
2236
2237
2238 static void
2239 df_chain_bottom_dump (basic_block bb, FILE *file)
2240 {
2241 if (df_chain_problem_p (DF_UD_CHAIN))
2242 {
2243 rtx insn;
2244 df_ref *use_rec = df_get_artificial_uses (bb->index);
2245
2246 if (*use_rec)
2247 {
2248 fprintf (file, ";; UD chains for artificial uses\n");
2249 while (*use_rec)
2250 {
2251 df_ref use = *use_rec;
2252 fprintf (file, ";; reg %d ", DF_REF_REGNO (use));
2253 df_chain_dump (DF_REF_CHAIN (use), file);
2254 fprintf (file, "\n");
2255 use_rec++;
2256 }
2257 }
2258
2259 FOR_BB_INSNS (bb, insn)
2260 {
2261 if (INSN_P (insn))
2262 {
2263 struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
2264 df_ref *eq_use_rec = DF_INSN_INFO_EQ_USES (insn_info);
2265 use_rec = DF_INSN_INFO_USES (insn_info);
2266 if (*use_rec || *eq_use_rec)
2267 {
2268 fprintf (file, ";; UD chains for insn luid %d uid %d\n",
2269 DF_INSN_INFO_LUID (insn_info), INSN_UID (insn));
2270
2271 while (*use_rec)
2272 {
2273 df_ref use = *use_rec;
2274 fprintf (file, ";; reg %d ", DF_REF_REGNO (use));
2275 if (DF_REF_FLAGS (use) & DF_REF_READ_WRITE)
2276 fprintf (file, "read/write ");
2277 df_chain_dump (DF_REF_CHAIN (use), file);
2278 fprintf (file, "\n");
2279 use_rec++;
2280 }
2281 while (*eq_use_rec)
2282 {
2283 df_ref use = *eq_use_rec;
2284 fprintf (file, ";; eq_note reg %d ", DF_REF_REGNO (use));
2285 df_chain_dump (DF_REF_CHAIN (use), file);
2286 fprintf (file, "\n");
2287 eq_use_rec++;
2288 }
2289 }
2290 }
2291 }
2292 }
2293 }
2294
2295
2296 static struct df_problem problem_CHAIN =
2297 {
2298 DF_CHAIN, /* Problem id. */
2299 DF_NONE, /* Direction. */
2300 df_chain_alloc, /* Allocate the problem specific data. */
2301 df_chain_reset, /* Reset global information. */
2302 NULL, /* Free basic block info. */
2303 NULL, /* Local compute function. */
2304 NULL, /* Init the solution specific data. */
2305 NULL, /* Iterative solver. */
2306 NULL, /* Confluence operator 0. */
2307 NULL, /* Confluence operator n. */
2308 NULL, /* Transfer function. */
2309 df_chain_finalize, /* Finalize function. */
2310 df_chain_free, /* Free all of the problem information. */
2311 df_chain_fully_remove_problem,/* Remove this problem from the stack of dataflow problems. */
2312 NULL, /* Debugging. */
2313 df_chain_top_dump, /* Debugging start block. */
2314 df_chain_bottom_dump, /* Debugging end block. */
2315 NULL, /* Incremental solution verify start. */
2316 NULL, /* Incremental solution verify end. */
2317 &problem_RD, /* Dependent problem. */
2318 TV_DF_CHAIN, /* Timing variable. */
2319 false /* Reset blocks on dropping out of blocks_to_analyze. */
2320 };
2321
2322
2323 /* Create a new DATAFLOW instance and add it to an existing instance
2324 of DF. The returned structure is what is used to get at the
2325 solution. */
2326
2327 void
2328 df_chain_add_problem (enum df_chain_flags chain_flags)
2329 {
2330 df_add_problem (&problem_CHAIN);
2331 df_chain->local_flags = (unsigned int)chain_flags;
2332 df_chain->out_of_date_transfer_functions = BITMAP_ALLOC (NULL);
2333 }
2334
2335 #undef df_chain_problem_p
2336
2337
2338 /*----------------------------------------------------------------------------
2339 BYTE LEVEL LIVE REGISTERS
2340
2341 Find the locations in the function where any use of a pseudo can
2342 reach in the backwards direction. In and out bitvectors are built
2343 for each basic block. There are two mapping functions,
2344 df_byte_lr_get_regno_start and df_byte_lr_get_regno_len that are
2345 used to map regnos into bit vector positions.
2346
2347 This problem differs from the regular df_lr function in the way
2348 that subregs, *_extracts and strict_low_parts are handled. In lr
2349 these are consider partial kills, here, the exact set of bytes is
2350 modeled. Note that any reg that has none of these operations is
2351 only modeled with a single bit since all operations access the
2352 entire register.
2353
2354 This problem is more brittle that the regular lr. It currently can
2355 be used in dce incrementally, but cannot be used in an environment
2356 where insns are created or modified. The problem is that the
2357 mapping of regnos to bitmap positions is relatively compact, in
2358 that if a pseudo does not do any of the byte wise operations, only
2359 one slot is allocated, rather than a slot for each byte. If insn
2360 are created, where a subreg is used for a reg that had no subregs,
2361 the mapping would be wrong. Likewise, there are no checks to see
2362 that new pseudos have been added. These issues could be addressed
2363 by adding a problem specific flag to not use the compact mapping,
2364 if there was a need to do so.
2365
2366 ----------------------------------------------------------------------------*/
2367
2368 /* Private data used to verify the solution for this problem. */
2369 struct df_byte_lr_problem_data
2370 {
2371 /* Expanded versions of bitvectors used in lr. */
2372 bitmap invalidated_by_call;
2373 bitmap hardware_regs_used;
2374
2375 /* Indexed by regno, this is true if there are subregs, extracts or
2376 strict_low_parts for this regno. */
2377 bitmap needs_expansion;
2378
2379 /* The start position and len for each regno in the various bit
2380 vectors. */
2381 unsigned int* regno_start;
2382 unsigned int* regno_len;
2383 /* An obstack for the bitmaps we need for this problem. */
2384 bitmap_obstack byte_lr_bitmaps;
2385 };
2386
2387
2388 /* Get the starting location for REGNO in the df_byte_lr bitmaps. */
2389
2390 int
2391 df_byte_lr_get_regno_start (unsigned int regno)
2392 {
2393 struct df_byte_lr_problem_data *problem_data
2394 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;;
2395 return problem_data->regno_start[regno];
2396 }
2397
2398
2399 /* Get the len for REGNO in the df_byte_lr bitmaps. */
2400
2401 int
2402 df_byte_lr_get_regno_len (unsigned int regno)
2403 {
2404 struct df_byte_lr_problem_data *problem_data
2405 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;;
2406 return problem_data->regno_len[regno];
2407 }
2408
2409
2410 /* Set basic block info. */
2411
2412 static void
2413 df_byte_lr_set_bb_info (unsigned int index,
2414 struct df_byte_lr_bb_info *bb_info)
2415 {
2416 gcc_assert (df_byte_lr);
2417 gcc_assert (index < df_byte_lr->block_info_size);
2418 df_byte_lr->block_info[index] = bb_info;
2419 }
2420
2421
2422 /* Free basic block info. */
2423
2424 static void
2425 df_byte_lr_free_bb_info (basic_block bb ATTRIBUTE_UNUSED,
2426 void *vbb_info)
2427 {
2428 struct df_byte_lr_bb_info *bb_info = (struct df_byte_lr_bb_info *) vbb_info;
2429 if (bb_info)
2430 {
2431 BITMAP_FREE (bb_info->use);
2432 BITMAP_FREE (bb_info->def);
2433 BITMAP_FREE (bb_info->in);
2434 BITMAP_FREE (bb_info->out);
2435 pool_free (df_byte_lr->block_pool, bb_info);
2436 }
2437 }
2438
2439
2440 /* Check all of the refs in REF_REC to see if any of them are
2441 extracts, subregs or strict_low_parts. */
2442
2443 static void
2444 df_byte_lr_check_regs (df_ref *ref_rec)
2445 {
2446 struct df_byte_lr_problem_data *problem_data
2447 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
2448
2449 for (; *ref_rec; ref_rec++)
2450 {
2451 df_ref ref = *ref_rec;
2452 if (DF_REF_FLAGS_IS_SET (ref, DF_REF_SIGN_EXTRACT
2453 | DF_REF_ZERO_EXTRACT
2454 | DF_REF_STRICT_LOW_PART)
2455 || GET_CODE (DF_REF_REG (ref)) == SUBREG)
2456 bitmap_set_bit (problem_data->needs_expansion, DF_REF_REGNO (ref));
2457 }
2458 }
2459
2460
2461 /* Expand bitmap SRC which is indexed by regno to DEST which is indexed by
2462 regno_start and regno_len. */
2463
2464 static void
2465 df_byte_lr_expand_bitmap (bitmap dest, bitmap src)
2466 {
2467 struct df_byte_lr_problem_data *problem_data
2468 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
2469 bitmap_iterator bi;
2470 unsigned int i;
2471
2472 bitmap_clear (dest);
2473 EXECUTE_IF_SET_IN_BITMAP (src, 0, i, bi)
2474 {
2475 bitmap_set_range (dest, problem_data->regno_start[i],
2476 problem_data->regno_len[i]);
2477 }
2478 }
2479
2480
2481 /* Allocate or reset bitmaps for DF_BYTE_LR blocks. The solution bits are
2482 not touched unless the block is new. */
2483
2484 static void
2485 df_byte_lr_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
2486 {
2487 unsigned int bb_index;
2488 bitmap_iterator bi;
2489 basic_block bb;
2490 unsigned int regno;
2491 unsigned int index = 0;
2492 unsigned int max_reg = max_reg_num();
2493 struct df_byte_lr_problem_data *problem_data
2494 = problem_data = XNEW (struct df_byte_lr_problem_data);
2495
2496 df_byte_lr->problem_data = problem_data;
2497
2498 if (!df_byte_lr->block_pool)
2499 df_byte_lr->block_pool = create_alloc_pool ("df_byte_lr_block pool",
2500 sizeof (struct df_byte_lr_bb_info), 50);
2501
2502 df_grow_bb_info (df_byte_lr);
2503
2504 /* Create the mapping from regnos to slots. This does not change
2505 unless the problem is destroyed and recreated. In particular, if
2506 we end up deleting the only insn that used a subreg, we do not
2507 want to redo the mapping because this would invalidate everything
2508 else. */
2509
2510 bitmap_obstack_initialize (&problem_data->byte_lr_bitmaps);
2511 problem_data->regno_start = XNEWVEC (unsigned int, max_reg);
2512 problem_data->regno_len = XNEWVEC (unsigned int, max_reg);
2513 problem_data->hardware_regs_used = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
2514 problem_data->invalidated_by_call = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
2515 problem_data->needs_expansion = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
2516
2517 /* Discover which regno's use subregs, extracts or
2518 strict_low_parts. */
2519 FOR_EACH_BB (bb)
2520 {
2521 rtx insn;
2522 FOR_BB_INSNS (bb, insn)
2523 {
2524 if (INSN_P (insn))
2525 {
2526 struct df_insn_info *insn_info = DF_INSN_INFO_GET (insn);
2527 df_byte_lr_check_regs (DF_INSN_INFO_DEFS (insn_info));
2528 df_byte_lr_check_regs (DF_INSN_INFO_USES (insn_info));
2529 }
2530 }
2531 bitmap_set_bit (df_byte_lr->out_of_date_transfer_functions, bb->index);
2532 }
2533
2534 bitmap_set_bit (df_byte_lr->out_of_date_transfer_functions, ENTRY_BLOCK);
2535 bitmap_set_bit (df_byte_lr->out_of_date_transfer_functions, EXIT_BLOCK);
2536
2537 /* Allocate the slots for each regno. */
2538 for (regno = 0; regno < max_reg; regno++)
2539 {
2540 int len;
2541 problem_data->regno_start[regno] = index;
2542 if (bitmap_bit_p (problem_data->needs_expansion, regno))
2543 len = GET_MODE_SIZE (GET_MODE (regno_reg_rtx[regno]));
2544 else
2545 len = 1;
2546
2547 problem_data->regno_len[regno] = len;
2548 index += len;
2549 }
2550
2551 df_byte_lr_expand_bitmap (problem_data->hardware_regs_used,
2552 df->hardware_regs_used);
2553 df_byte_lr_expand_bitmap (problem_data->invalidated_by_call,
2554 regs_invalidated_by_call_regset);
2555
2556 EXECUTE_IF_SET_IN_BITMAP (df_byte_lr->out_of_date_transfer_functions, 0, bb_index, bi)
2557 {
2558 struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
2559 if (bb_info)
2560 {
2561 bitmap_clear (bb_info->def);
2562 bitmap_clear (bb_info->use);
2563 }
2564 else
2565 {
2566 bb_info = (struct df_byte_lr_bb_info *) pool_alloc (df_byte_lr->block_pool);
2567 df_byte_lr_set_bb_info (bb_index, bb_info);
2568 bb_info->use = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
2569 bb_info->def = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
2570 bb_info->in = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
2571 bb_info->out = BITMAP_ALLOC (&problem_data->byte_lr_bitmaps);
2572 }
2573 }
2574
2575 df_byte_lr->optional_p = true;
2576 }
2577
2578
2579 /* Reset the global solution for recalculation. */
2580
2581 static void
2582 df_byte_lr_reset (bitmap all_blocks)
2583 {
2584 unsigned int bb_index;
2585 bitmap_iterator bi;
2586
2587 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
2588 {
2589 struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
2590 gcc_assert (bb_info);
2591 bitmap_clear (bb_info->in);
2592 bitmap_clear (bb_info->out);
2593 }
2594 }
2595
2596
2597 /* Compute local live register info for basic block BB. */
2598
2599 static void
2600 df_byte_lr_bb_local_compute (unsigned int bb_index)
2601 {
2602 struct df_byte_lr_problem_data *problem_data
2603 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
2604 basic_block bb = BASIC_BLOCK (bb_index);
2605 struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
2606 rtx insn;
2607 df_ref *def_rec;
2608 df_ref *use_rec;
2609
2610 /* Process the registers set in an exception handler. */
2611 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
2612 {
2613 df_ref def = *def_rec;
2614 if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
2615 {
2616 unsigned int dregno = DF_REF_REGNO (def);
2617 unsigned int start = problem_data->regno_start[dregno];
2618 unsigned int len = problem_data->regno_len[dregno];
2619 bitmap_set_range (bb_info->def, start, len);
2620 bitmap_clear_range (bb_info->use, start, len);
2621 }
2622 }
2623
2624 /* Process the hardware registers that are always live. */
2625 for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
2626 {
2627 df_ref use = *use_rec;
2628 /* Add use to set of uses in this BB. */
2629 if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0)
2630 {
2631 unsigned int uregno = DF_REF_REGNO (use);
2632 unsigned int start = problem_data->regno_start[uregno];
2633 unsigned int len = problem_data->regno_len[uregno];
2634 bitmap_set_range (bb_info->use, start, len);
2635 }
2636 }
2637
2638 FOR_BB_INSNS_REVERSE (bb, insn)
2639 {
2640 unsigned int uid = INSN_UID (insn);
2641
2642 if (!INSN_P (insn))
2643 continue;
2644
2645 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
2646 {
2647 df_ref def = *def_rec;
2648 /* If the def is to only part of the reg, it does
2649 not kill the other defs that reach here. */
2650 if (!(DF_REF_FLAGS (def) & (DF_REF_CONDITIONAL)))
2651 {
2652 unsigned int dregno = DF_REF_REGNO (def);
2653 unsigned int start = problem_data->regno_start[dregno];
2654 unsigned int len = problem_data->regno_len[dregno];
2655 unsigned int sb;
2656 unsigned int lb;
2657 if (!df_compute_accessed_bytes (def, DF_MM_MUST, &sb, &lb))
2658 {
2659 start += sb;
2660 len = lb - sb;
2661 }
2662 if (len)
2663 {
2664 bitmap_set_range (bb_info->def, start, len);
2665 bitmap_clear_range (bb_info->use, start, len);
2666 }
2667 }
2668 }
2669
2670 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
2671 {
2672 df_ref use = *use_rec;
2673 unsigned int uregno = DF_REF_REGNO (use);
2674 unsigned int start = problem_data->regno_start[uregno];
2675 unsigned int len = problem_data->regno_len[uregno];
2676 unsigned int sb;
2677 unsigned int lb;
2678 if (!df_compute_accessed_bytes (use, DF_MM_MAY, &sb, &lb))
2679 {
2680 start += sb;
2681 len = lb - sb;
2682 }
2683 /* Add use to set of uses in this BB. */
2684 if (len)
2685 bitmap_set_range (bb_info->use, start, len);
2686 }
2687 }
2688
2689 /* Process the registers set in an exception handler or the hard
2690 frame pointer if this block is the target of a non local
2691 goto. */
2692 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
2693 {
2694 df_ref def = *def_rec;
2695 if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
2696 {
2697 unsigned int dregno = DF_REF_REGNO (def);
2698 unsigned int start = problem_data->regno_start[dregno];
2699 unsigned int len = problem_data->regno_len[dregno];
2700 bitmap_set_range (bb_info->def, start, len);
2701 bitmap_clear_range (bb_info->use, start, len);
2702 }
2703 }
2704
2705 #ifdef EH_USES
2706 /* Process the uses that are live into an exception handler. */
2707 for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
2708 {
2709 df_ref use = *use_rec;
2710 /* Add use to set of uses in this BB. */
2711 if (DF_REF_FLAGS (use) & DF_REF_AT_TOP)
2712 {
2713 unsigned int uregno = DF_REF_REGNO (use);
2714 unsigned int start = problem_data->regno_start[uregno];
2715 unsigned int len = problem_data->regno_len[uregno];
2716 bitmap_set_range (bb_info->use, start, len);
2717 }
2718 }
2719 #endif
2720 }
2721
2722
2723 /* Compute local live register info for each basic block within BLOCKS. */
2724
2725 static void
2726 df_byte_lr_local_compute (bitmap all_blocks ATTRIBUTE_UNUSED)
2727 {
2728 unsigned int bb_index;
2729 bitmap_iterator bi;
2730
2731 EXECUTE_IF_SET_IN_BITMAP (df_byte_lr->out_of_date_transfer_functions, 0, bb_index, bi)
2732 {
2733 if (bb_index == EXIT_BLOCK)
2734 {
2735 /* The exit block is special for this problem and its bits are
2736 computed from thin air. */
2737 struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (EXIT_BLOCK);
2738 df_byte_lr_expand_bitmap (bb_info->use, df->exit_block_uses);
2739 }
2740 else
2741 df_byte_lr_bb_local_compute (bb_index);
2742 }
2743
2744 bitmap_clear (df_byte_lr->out_of_date_transfer_functions);
2745 }
2746
2747
2748 /* Initialize the solution vectors. */
2749
2750 static void
2751 df_byte_lr_init (bitmap all_blocks)
2752 {
2753 unsigned int bb_index;
2754 bitmap_iterator bi;
2755
2756 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
2757 {
2758 struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
2759 bitmap_copy (bb_info->in, bb_info->use);
2760 bitmap_clear (bb_info->out);
2761 }
2762 }
2763
2764
2765 /* Confluence function that processes infinite loops. This might be a
2766 noreturn function that throws. And even if it isn't, getting the
2767 unwind info right helps debugging. */
2768 static void
2769 df_byte_lr_confluence_0 (basic_block bb)
2770 {
2771 struct df_byte_lr_problem_data *problem_data
2772 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
2773 bitmap op1 = df_byte_lr_get_bb_info (bb->index)->out;
2774 if (bb != EXIT_BLOCK_PTR)
2775 bitmap_copy (op1, problem_data->hardware_regs_used);
2776 }
2777
2778
2779 /* Confluence function that ignores fake edges. */
2780
2781 static void
2782 df_byte_lr_confluence_n (edge e)
2783 {
2784 struct df_byte_lr_problem_data *problem_data
2785 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
2786 bitmap op1 = df_byte_lr_get_bb_info (e->src->index)->out;
2787 bitmap op2 = df_byte_lr_get_bb_info (e->dest->index)->in;
2788
2789 /* Call-clobbered registers die across exception and call edges. */
2790 /* ??? Abnormal call edges ignored for the moment, as this gets
2791 confused by sibling call edges, which crashes reg-stack. */
2792 if (e->flags & EDGE_EH)
2793 bitmap_ior_and_compl_into (op1, op2, problem_data->invalidated_by_call);
2794 else
2795 bitmap_ior_into (op1, op2);
2796
2797 bitmap_ior_into (op1, problem_data->hardware_regs_used);
2798 }
2799
2800
2801 /* Transfer function. */
2802
2803 static bool
2804 df_byte_lr_transfer_function (int bb_index)
2805 {
2806 struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb_index);
2807 bitmap in = bb_info->in;
2808 bitmap out = bb_info->out;
2809 bitmap use = bb_info->use;
2810 bitmap def = bb_info->def;
2811
2812 return bitmap_ior_and_compl (in, use, out, def);
2813 }
2814
2815
2816 /* Free all storage associated with the problem. */
2817
2818 static void
2819 df_byte_lr_free (void)
2820 {
2821 struct df_byte_lr_problem_data *problem_data
2822 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
2823
2824
2825 if (df_byte_lr->block_info)
2826 {
2827 free_alloc_pool (df_byte_lr->block_pool);
2828 df_byte_lr->block_info_size = 0;
2829 free (df_byte_lr->block_info);
2830 }
2831
2832 BITMAP_FREE (df_byte_lr->out_of_date_transfer_functions);
2833 bitmap_obstack_release (&problem_data->byte_lr_bitmaps);
2834 free (problem_data->regno_start);
2835 free (problem_data->regno_len);
2836 free (problem_data);
2837 free (df_byte_lr);
2838 }
2839
2840
2841 /* Debugging info at top of bb. */
2842
2843 static void
2844 df_byte_lr_top_dump (basic_block bb, FILE *file)
2845 {
2846 struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb->index);
2847 if (!bb_info || !bb_info->in)
2848 return;
2849
2850 fprintf (file, ";; blr in \t");
2851 df_print_byte_regset (file, bb_info->in);
2852 fprintf (file, ";; blr use \t");
2853 df_print_byte_regset (file, bb_info->use);
2854 fprintf (file, ";; blr def \t");
2855 df_print_byte_regset (file, bb_info->def);
2856 }
2857
2858
2859 /* Debugging info at bottom of bb. */
2860
2861 static void
2862 df_byte_lr_bottom_dump (basic_block bb, FILE *file)
2863 {
2864 struct df_byte_lr_bb_info *bb_info = df_byte_lr_get_bb_info (bb->index);
2865 if (!bb_info || !bb_info->out)
2866 return;
2867
2868 fprintf (file, ";; blr out \t");
2869 df_print_byte_regset (file, bb_info->out);
2870 }
2871
2872
2873 /* All of the information associated with every instance of the problem. */
2874
2875 static struct df_problem problem_BYTE_LR =
2876 {
2877 DF_BYTE_LR, /* Problem id. */
2878 DF_BACKWARD, /* Direction. */
2879 df_byte_lr_alloc, /* Allocate the problem specific data. */
2880 df_byte_lr_reset, /* Reset global information. */
2881 df_byte_lr_free_bb_info, /* Free basic block info. */
2882 df_byte_lr_local_compute, /* Local compute function. */
2883 df_byte_lr_init, /* Init the solution specific data. */
2884 df_worklist_dataflow, /* Worklist solver. */
2885 df_byte_lr_confluence_0, /* Confluence operator 0. */
2886 df_byte_lr_confluence_n, /* Confluence operator n. */
2887 df_byte_lr_transfer_function, /* Transfer function. */
2888 NULL, /* Finalize function. */
2889 df_byte_lr_free, /* Free all of the problem information. */
2890 df_byte_lr_free, /* Remove this problem from the stack of dataflow problems. */
2891 NULL, /* Debugging. */
2892 df_byte_lr_top_dump, /* Debugging start block. */
2893 df_byte_lr_bottom_dump, /* Debugging end block. */
2894 NULL, /* Incremental solution verify start. */
2895 NULL, /* Incremental solution verify end. */
2896 NULL, /* Dependent problem. */
2897 TV_DF_BYTE_LR, /* Timing variable. */
2898 false /* Reset blocks on dropping out of blocks_to_analyze. */
2899 };
2900
2901
2902 /* Create a new DATAFLOW instance and add it to an existing instance
2903 of DF. The returned structure is what is used to get at the
2904 solution. */
2905
2906 void
2907 df_byte_lr_add_problem (void)
2908 {
2909 df_add_problem (&problem_BYTE_LR);
2910 /* These will be initialized when df_scan_blocks processes each
2911 block. */
2912 df_byte_lr->out_of_date_transfer_functions = BITMAP_ALLOC (NULL);
2913 }
2914
2915
2916 /* Simulate the effects of the defs of INSN on LIVE. */
2917
2918 void
2919 df_byte_lr_simulate_defs (rtx insn, bitmap live)
2920 {
2921 struct df_byte_lr_problem_data *problem_data
2922 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
2923 df_ref *def_rec;
2924 unsigned int uid = INSN_UID (insn);
2925
2926 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
2927 {
2928 df_ref def = *def_rec;
2929
2930 /* If the def is to only part of the reg, it does
2931 not kill the other defs that reach here. */
2932 if (!(DF_REF_FLAGS (def) & DF_REF_CONDITIONAL))
2933 {
2934 unsigned int dregno = DF_REF_REGNO (def);
2935 unsigned int start = problem_data->regno_start[dregno];
2936 unsigned int len = problem_data->regno_len[dregno];
2937 unsigned int sb;
2938 unsigned int lb;
2939 if (!df_compute_accessed_bytes (def, DF_MM_MUST, &sb, &lb))
2940 {
2941 start += sb;
2942 len = lb - sb;
2943 }
2944
2945 if (len)
2946 bitmap_clear_range (live, start, len);
2947 }
2948 }
2949 }
2950
2951
2952 /* Simulate the effects of the uses of INSN on LIVE. */
2953
2954 void
2955 df_byte_lr_simulate_uses (rtx insn, bitmap live)
2956 {
2957 struct df_byte_lr_problem_data *problem_data
2958 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
2959 df_ref *use_rec;
2960 unsigned int uid = INSN_UID (insn);
2961
2962 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
2963 {
2964 df_ref use = *use_rec;
2965 unsigned int uregno = DF_REF_REGNO (use);
2966 unsigned int start = problem_data->regno_start[uregno];
2967 unsigned int len = problem_data->regno_len[uregno];
2968 unsigned int sb;
2969 unsigned int lb;
2970
2971 if (!df_compute_accessed_bytes (use, DF_MM_MAY, &sb, &lb))
2972 {
2973 start += sb;
2974 len = lb - sb;
2975 }
2976
2977 /* Add use to set of uses in this BB. */
2978 if (len)
2979 bitmap_set_range (live, start, len);
2980 }
2981 }
2982
2983
2984 /* Apply the artificial uses and defs at the top of BB in a forwards
2985 direction. */
2986
2987 void
2988 df_byte_lr_simulate_artificial_refs_at_top (basic_block bb, bitmap live)
2989 {
2990 struct df_byte_lr_problem_data *problem_data
2991 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
2992 df_ref *def_rec;
2993 #ifdef EH_USES
2994 df_ref *use_rec;
2995 #endif
2996 int bb_index = bb->index;
2997
2998 #ifdef EH_USES
2999 for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
3000 {
3001 df_ref use = *use_rec;
3002 if (DF_REF_FLAGS (use) & DF_REF_AT_TOP)
3003 {
3004 unsigned int uregno = DF_REF_REGNO (use);
3005 unsigned int start = problem_data->regno_start[uregno];
3006 unsigned int len = problem_data->regno_len[uregno];
3007 bitmap_set_range (live, start, len);
3008 }
3009 }
3010 #endif
3011
3012 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
3013 {
3014 df_ref def = *def_rec;
3015 if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
3016 {
3017 unsigned int dregno = DF_REF_REGNO (def);
3018 unsigned int start = problem_data->regno_start[dregno];
3019 unsigned int len = problem_data->regno_len[dregno];
3020 bitmap_clear_range (live, start, len);
3021 }
3022 }
3023 }
3024
3025
3026 /* Apply the artificial uses and defs at the end of BB in a backwards
3027 direction. */
3028
3029 void
3030 df_byte_lr_simulate_artificial_refs_at_end (basic_block bb, bitmap live)
3031 {
3032 struct df_byte_lr_problem_data *problem_data
3033 = (struct df_byte_lr_problem_data *)df_byte_lr->problem_data;
3034 df_ref *def_rec;
3035 df_ref *use_rec;
3036 int bb_index = bb->index;
3037
3038 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
3039 {
3040 df_ref def = *def_rec;
3041 if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
3042 {
3043 unsigned int dregno = DF_REF_REGNO (def);
3044 unsigned int start = problem_data->regno_start[dregno];
3045 unsigned int len = problem_data->regno_len[dregno];
3046 bitmap_clear_range (live, start, len);
3047 }
3048 }
3049
3050 for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
3051 {
3052 df_ref use = *use_rec;
3053 if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0)
3054 {
3055 unsigned int uregno = DF_REF_REGNO (use);
3056 unsigned int start = problem_data->regno_start[uregno];
3057 unsigned int len = problem_data->regno_len[uregno];
3058 bitmap_set_range (live, start, len);
3059 }
3060 }
3061 }
3062
3063
3064
3065 /*----------------------------------------------------------------------------
3066 This problem computes REG_DEAD and REG_UNUSED notes.
3067 ----------------------------------------------------------------------------*/
3068
3069 static void
3070 df_note_alloc (bitmap all_blocks ATTRIBUTE_UNUSED)
3071 {
3072 df_note->optional_p = true;
3073 }
3074
3075 #ifdef REG_DEAD_DEBUGGING
3076 static void
3077 df_print_note (const char *prefix, rtx insn, rtx note)
3078 {
3079 if (dump_file)
3080 {
3081 fprintf (dump_file, "%s %d ", prefix, INSN_UID (insn));
3082 print_rtl (dump_file, note);
3083 fprintf (dump_file, "\n");
3084 }
3085 }
3086 #endif
3087
3088
3089 /* After reg-stack, the x86 floating point stack regs are difficult to
3090 analyze because of all of the pushes, pops and rotations. Thus, we
3091 just leave the notes alone. */
3092
3093 #ifdef STACK_REGS
3094 static inline bool
3095 df_ignore_stack_reg (int regno)
3096 {
3097 return regstack_completed
3098 && IN_RANGE (regno, FIRST_STACK_REG, LAST_STACK_REG);
3099 }
3100 #else
3101 static inline bool
3102 df_ignore_stack_reg (int regno ATTRIBUTE_UNUSED)
3103 {
3104 return false;
3105 }
3106 #endif
3107
3108
3109 /* Remove all of the REG_DEAD or REG_UNUSED notes from INSN and add
3110 them to OLD_DEAD_NOTES and OLD_UNUSED_NOTES. */
3111
3112 static void
3113 df_kill_notes (rtx insn, rtx *old_dead_notes, rtx *old_unused_notes)
3114 {
3115 rtx *pprev = &REG_NOTES (insn);
3116 rtx link = *pprev;
3117 rtx dead = NULL;
3118 rtx unused = NULL;
3119
3120 while (link)
3121 {
3122 switch (REG_NOTE_KIND (link))
3123 {
3124 case REG_DEAD:
3125 /* After reg-stack, we need to ignore any unused notes
3126 for the stack registers. */
3127 if (df_ignore_stack_reg (REGNO (XEXP (link, 0))))
3128 {
3129 pprev = &XEXP (link, 1);
3130 link = *pprev;
3131 }
3132 else
3133 {
3134 rtx next = XEXP (link, 1);
3135 #ifdef REG_DEAD_DEBUGGING
3136 df_print_note ("deleting: ", insn, link);
3137 #endif
3138 XEXP (link, 1) = dead;
3139 dead = link;
3140 *pprev = link = next;
3141 }
3142 break;
3143
3144 case REG_UNUSED:
3145 /* After reg-stack, we need to ignore any unused notes
3146 for the stack registers. */
3147 if (df_ignore_stack_reg (REGNO (XEXP (link, 0))))
3148 {
3149 pprev = &XEXP (link, 1);
3150 link = *pprev;
3151 }
3152 else
3153 {
3154 rtx next = XEXP (link, 1);
3155 #ifdef REG_DEAD_DEBUGGING
3156 df_print_note ("deleting: ", insn, link);
3157 #endif
3158 XEXP (link, 1) = unused;
3159 unused = link;
3160 *pprev = link = next;
3161 }
3162 break;
3163
3164 default:
3165 pprev = &XEXP (link, 1);
3166 link = *pprev;
3167 break;
3168 }
3169 }
3170
3171 *old_dead_notes = dead;
3172 *old_unused_notes = unused;
3173 }
3174
3175
3176 /* Set a NOTE_TYPE note for REG in INSN. Try to pull it from the OLD
3177 list, otherwise create a new one. */
3178
3179 static inline rtx
3180 df_set_note (enum reg_note note_type, rtx insn, rtx old, rtx reg)
3181 {
3182 rtx curr = old;
3183 rtx prev = NULL;
3184
3185 while (curr)
3186 if (XEXP (curr, 0) == reg)
3187 {
3188 if (prev)
3189 XEXP (prev, 1) = XEXP (curr, 1);
3190 else
3191 old = XEXP (curr, 1);
3192 XEXP (curr, 1) = REG_NOTES (insn);
3193 REG_NOTES (insn) = curr;
3194 return old;
3195 }
3196 else
3197 {
3198 prev = curr;
3199 curr = XEXP (curr, 1);
3200 }
3201
3202 /* Did not find the note. */
3203 add_reg_note (insn, note_type, reg);
3204 return old;
3205 }
3206
3207 /* A subroutine of df_set_unused_notes_for_mw, with a selection of its
3208 arguments. Return true if the register value described by MWS's
3209 mw_reg is known to be completely unused, and if mw_reg can therefore
3210 be used in a REG_UNUSED note. */
3211
3212 static bool
3213 df_whole_mw_reg_unused_p (struct df_mw_hardreg *mws,
3214 bitmap live, bitmap artificial_uses)
3215 {
3216 unsigned int r;
3217
3218 /* If MWS describes a partial reference, create REG_UNUSED notes for
3219 individual hard registers. */
3220 if (mws->flags & DF_REF_PARTIAL)
3221 return false;
3222
3223 /* Likewise if some part of the register is used. */
3224 for (r = mws->start_regno; r <= mws->end_regno; r++)
3225 if (bitmap_bit_p (live, r)
3226 || bitmap_bit_p (artificial_uses, r))
3227 return false;
3228
3229 gcc_assert (REG_P (mws->mw_reg));
3230 return true;
3231 }
3232
3233 /* Set the REG_UNUSED notes for the multiword hardreg defs in INSN
3234 based on the bits in LIVE. Do not generate notes for registers in
3235 artificial uses. DO_NOT_GEN is updated so that REG_DEAD notes are
3236 not generated if the reg is both read and written by the
3237 instruction.
3238 */
3239
3240 static rtx
3241 df_set_unused_notes_for_mw (rtx insn, rtx old, struct df_mw_hardreg *mws,
3242 bitmap live, bitmap do_not_gen,
3243 bitmap artificial_uses)
3244 {
3245 unsigned int r;
3246
3247 #ifdef REG_DEAD_DEBUGGING
3248 if (dump_file)
3249 fprintf (dump_file, "mw_set_unused looking at mws[%d..%d]\n",
3250 mws->start_regno, mws->end_regno);
3251 #endif
3252
3253 if (df_whole_mw_reg_unused_p (mws, live, artificial_uses))
3254 {
3255 unsigned int regno = mws->start_regno;
3256 old = df_set_note (REG_UNUSED, insn, old, mws->mw_reg);
3257
3258 #ifdef REG_DEAD_DEBUGGING
3259 df_print_note ("adding 1: ", insn, REG_NOTES (insn));
3260 #endif
3261 bitmap_set_bit (do_not_gen, regno);
3262 /* Only do this if the value is totally dead. */
3263 }
3264 else
3265 for (r = mws->start_regno; r <= mws->end_regno; r++)
3266 {
3267 if (!bitmap_bit_p (live, r)
3268 && !bitmap_bit_p (artificial_uses, r))
3269 {
3270 old = df_set_note (REG_UNUSED, insn, old, regno_reg_rtx[r]);
3271 #ifdef REG_DEAD_DEBUGGING
3272 df_print_note ("adding 2: ", insn, REG_NOTES (insn));
3273 #endif
3274 }
3275 bitmap_set_bit (do_not_gen, r);
3276 }
3277 return old;
3278 }
3279
3280
3281 /* A subroutine of df_set_dead_notes_for_mw, with a selection of its
3282 arguments. Return true if the register value described by MWS's
3283 mw_reg is known to be completely dead, and if mw_reg can therefore
3284 be used in a REG_DEAD note. */
3285
3286 static bool
3287 df_whole_mw_reg_dead_p (struct df_mw_hardreg *mws,
3288 bitmap live, bitmap artificial_uses,
3289 bitmap do_not_gen)
3290 {
3291 unsigned int r;
3292
3293 /* If MWS describes a partial reference, create REG_DEAD notes for
3294 individual hard registers. */
3295 if (mws->flags & DF_REF_PARTIAL)
3296 return false;
3297
3298 /* Likewise if some part of the register is not dead. */
3299 for (r = mws->start_regno; r <= mws->end_regno; r++)
3300 if (bitmap_bit_p (live, r)
3301 || bitmap_bit_p (artificial_uses, r)
3302 || bitmap_bit_p (do_not_gen, r))
3303 return false;
3304
3305 gcc_assert (REG_P (mws->mw_reg));
3306 return true;
3307 }
3308
3309 /* Set the REG_DEAD notes for the multiword hardreg use in INSN based
3310 on the bits in LIVE. DO_NOT_GEN is used to keep REG_DEAD notes
3311 from being set if the instruction both reads and writes the
3312 register. */
3313
3314 static rtx
3315 df_set_dead_notes_for_mw (rtx insn, rtx old, struct df_mw_hardreg *mws,
3316 bitmap live, bitmap do_not_gen,
3317 bitmap artificial_uses)
3318 {
3319 unsigned int r;
3320
3321 #ifdef REG_DEAD_DEBUGGING
3322 if (dump_file)
3323 {
3324 fprintf (dump_file, "mw_set_dead looking at mws[%d..%d]\n do_not_gen =",
3325 mws->start_regno, mws->end_regno);
3326 df_print_regset (dump_file, do_not_gen);
3327 fprintf (dump_file, " live =");
3328 df_print_regset (dump_file, live);
3329 fprintf (dump_file, " artificial uses =");
3330 df_print_regset (dump_file, artificial_uses);
3331 }
3332 #endif
3333
3334 if (df_whole_mw_reg_dead_p (mws, live, artificial_uses, do_not_gen))
3335 {
3336 /* Add a dead note for the entire multi word register. */
3337 old = df_set_note (REG_DEAD, insn, old, mws->mw_reg);
3338 #ifdef REG_DEAD_DEBUGGING
3339 df_print_note ("adding 1: ", insn, REG_NOTES (insn));
3340 #endif
3341 }
3342 else
3343 {
3344 for (r = mws->start_regno; r <= mws->end_regno; r++)
3345 if (!bitmap_bit_p (live, r)
3346 && !bitmap_bit_p (artificial_uses, r)
3347 && !bitmap_bit_p (do_not_gen, r))
3348 {
3349 old = df_set_note (REG_DEAD, insn, old, regno_reg_rtx[r]);
3350 #ifdef REG_DEAD_DEBUGGING
3351 df_print_note ("adding 2: ", insn, REG_NOTES (insn));
3352 #endif
3353 }
3354 }
3355 return old;
3356 }
3357
3358
3359 /* Create a REG_UNUSED note if necessary for DEF in INSN updating
3360 LIVE. Do not generate notes for registers in ARTIFICIAL_USES. */
3361
3362 static rtx
3363 df_create_unused_note (rtx insn, rtx old, df_ref def,
3364 bitmap live, bitmap artificial_uses)
3365 {
3366 unsigned int dregno = DF_REF_REGNO (def);
3367
3368 #ifdef REG_DEAD_DEBUGGING
3369 if (dump_file)
3370 {
3371 fprintf (dump_file, " regular looking at def ");
3372 df_ref_debug (def, dump_file);
3373 }
3374 #endif
3375
3376 if (!(bitmap_bit_p (live, dregno)
3377 || (DF_REF_FLAGS (def) & DF_REF_MW_HARDREG)
3378 || bitmap_bit_p (artificial_uses, dregno)
3379 || df_ignore_stack_reg (dregno)))
3380 {
3381 rtx reg = (DF_REF_LOC (def))
3382 ? *DF_REF_REAL_LOC (def): DF_REF_REG (def);
3383 old = df_set_note (REG_UNUSED, insn, old, reg);
3384 #ifdef REG_DEAD_DEBUGGING
3385 df_print_note ("adding 3: ", insn, REG_NOTES (insn));
3386 #endif
3387 }
3388
3389 return old;
3390 }
3391
3392
3393 /* Recompute the REG_DEAD and REG_UNUSED notes and compute register
3394 info: lifetime, bb, and number of defs and uses for basic block
3395 BB. The three bitvectors are scratch regs used here. */
3396
3397 static void
3398 df_note_bb_compute (unsigned int bb_index,
3399 bitmap live, bitmap do_not_gen, bitmap artificial_uses)
3400 {
3401 basic_block bb = BASIC_BLOCK (bb_index);
3402 rtx insn;
3403 df_ref *def_rec;
3404 df_ref *use_rec;
3405
3406 bitmap_copy (live, df_get_live_out (bb));
3407 bitmap_clear (artificial_uses);
3408
3409 #ifdef REG_DEAD_DEBUGGING
3410 if (dump_file)
3411 {
3412 fprintf (dump_file, "live at bottom ");
3413 df_print_regset (dump_file, live);
3414 }
3415 #endif
3416
3417 /* Process the artificial defs and uses at the bottom of the block
3418 to begin processing. */
3419 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
3420 {
3421 df_ref def = *def_rec;
3422 #ifdef REG_DEAD_DEBUGGING
3423 if (dump_file)
3424 fprintf (dump_file, "artificial def %d\n", DF_REF_REGNO (def));
3425 #endif
3426
3427 if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
3428 bitmap_clear_bit (live, DF_REF_REGNO (def));
3429 }
3430
3431 for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
3432 {
3433 df_ref use = *use_rec;
3434 if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0)
3435 {
3436 unsigned int regno = DF_REF_REGNO (use);
3437 bitmap_set_bit (live, regno);
3438
3439 /* Notes are not generated for any of the artificial registers
3440 at the bottom of the block. */
3441 bitmap_set_bit (artificial_uses, regno);
3442 }
3443 }
3444
3445 #ifdef REG_DEAD_DEBUGGING
3446 if (dump_file)
3447 {
3448 fprintf (dump_file, "live before artificials out ");
3449 df_print_regset (dump_file, live);
3450 }
3451 #endif
3452
3453 FOR_BB_INSNS_REVERSE (bb, insn)
3454 {
3455 unsigned int uid = INSN_UID (insn);
3456 struct df_mw_hardreg **mws_rec;
3457 rtx old_dead_notes;
3458 rtx old_unused_notes;
3459
3460 if (!INSN_P (insn))
3461 continue;
3462
3463 bitmap_clear (do_not_gen);
3464 df_kill_notes (insn, &old_dead_notes, &old_unused_notes);
3465
3466 /* Process the defs. */
3467 if (CALL_P (insn))
3468 {
3469 #ifdef REG_DEAD_DEBUGGING
3470 if (dump_file)
3471 {
3472 fprintf (dump_file, "processing call %d\n live =", INSN_UID (insn));
3473 df_print_regset (dump_file, live);
3474 }
3475 #endif
3476 /* We only care about real sets for calls. Clobbers cannot
3477 be depended on to really die. */
3478 mws_rec = DF_INSN_UID_MWS (uid);
3479 while (*mws_rec)
3480 {
3481 struct df_mw_hardreg *mws = *mws_rec;
3482 if ((DF_MWS_REG_DEF_P (mws))
3483 && !df_ignore_stack_reg (mws->start_regno))
3484 old_unused_notes
3485 = df_set_unused_notes_for_mw (insn, old_unused_notes,
3486 mws, live, do_not_gen,
3487 artificial_uses);
3488 mws_rec++;
3489 }
3490
3491 /* All of the defs except the return value are some sort of
3492 clobber. This code is for the return. */
3493 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
3494 {
3495 df_ref def = *def_rec;
3496 unsigned int dregno = DF_REF_REGNO (def);
3497 if (!DF_REF_FLAGS_IS_SET (def, DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER))
3498 {
3499 old_unused_notes
3500 = df_create_unused_note (insn, old_unused_notes,
3501 def, live, artificial_uses);
3502 bitmap_set_bit (do_not_gen, dregno);
3503 }
3504
3505 if (!DF_REF_FLAGS_IS_SET (def, DF_REF_PARTIAL | DF_REF_CONDITIONAL))
3506 bitmap_clear_bit (live, dregno);
3507 }
3508 }
3509 else
3510 {
3511 /* Regular insn. */
3512 mws_rec = DF_INSN_UID_MWS (uid);
3513 while (*mws_rec)
3514 {
3515 struct df_mw_hardreg *mws = *mws_rec;
3516 if (DF_MWS_REG_DEF_P (mws))
3517 old_unused_notes
3518 = df_set_unused_notes_for_mw (insn, old_unused_notes,
3519 mws, live, do_not_gen,
3520 artificial_uses);
3521 mws_rec++;
3522 }
3523
3524 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
3525 {
3526 df_ref def = *def_rec;
3527 unsigned int dregno = DF_REF_REGNO (def);
3528 old_unused_notes
3529 = df_create_unused_note (insn, old_unused_notes,
3530 def, live, artificial_uses);
3531
3532 if (!DF_REF_FLAGS_IS_SET (def, DF_REF_MUST_CLOBBER | DF_REF_MAY_CLOBBER))
3533 bitmap_set_bit (do_not_gen, dregno);
3534
3535 if (!DF_REF_FLAGS_IS_SET (def, DF_REF_PARTIAL | DF_REF_CONDITIONAL))
3536 bitmap_clear_bit (live, dregno);
3537 }
3538 }
3539
3540 /* Process the uses. */
3541 mws_rec = DF_INSN_UID_MWS (uid);
3542 while (*mws_rec)
3543 {
3544 struct df_mw_hardreg *mws = *mws_rec;
3545 if ((DF_MWS_REG_DEF_P (mws))
3546 && !df_ignore_stack_reg (mws->start_regno))
3547 old_dead_notes
3548 = df_set_dead_notes_for_mw (insn, old_dead_notes,
3549 mws, live, do_not_gen,
3550 artificial_uses);
3551 mws_rec++;
3552 }
3553
3554 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
3555 {
3556 df_ref use = *use_rec;
3557 unsigned int uregno = DF_REF_REGNO (use);
3558
3559 #ifdef REG_DEAD_DEBUGGING
3560 if (dump_file)
3561 {
3562 fprintf (dump_file, " regular looking at use ");
3563 df_ref_debug (use, dump_file);
3564 }
3565 #endif
3566 if (!bitmap_bit_p (live, uregno))
3567 {
3568 if ( (!(DF_REF_FLAGS (use) & DF_REF_MW_HARDREG))
3569 && (!bitmap_bit_p (do_not_gen, uregno))
3570 && (!bitmap_bit_p (artificial_uses, uregno))
3571 && (!(DF_REF_FLAGS (use) & DF_REF_READ_WRITE))
3572 && (!df_ignore_stack_reg (uregno)))
3573 {
3574 rtx reg = (DF_REF_LOC (use))
3575 ? *DF_REF_REAL_LOC (use) : DF_REF_REG (use);
3576 old_dead_notes = df_set_note (REG_DEAD, insn, old_dead_notes, reg);
3577
3578 #ifdef REG_DEAD_DEBUGGING
3579 df_print_note ("adding 4: ", insn, REG_NOTES (insn));
3580 #endif
3581 }
3582 /* This register is now live. */
3583 bitmap_set_bit (live, uregno);
3584 }
3585 }
3586
3587 while (old_unused_notes)
3588 {
3589 rtx next = XEXP (old_unused_notes, 1);
3590 free_EXPR_LIST_node (old_unused_notes);
3591 old_unused_notes = next;
3592 }
3593 while (old_dead_notes)
3594 {
3595 rtx next = XEXP (old_dead_notes, 1);
3596 free_EXPR_LIST_node (old_dead_notes);
3597 old_dead_notes = next;
3598 }
3599 }
3600 }
3601
3602
3603 /* Compute register info: lifetime, bb, and number of defs and uses. */
3604 static void
3605 df_note_compute (bitmap all_blocks)
3606 {
3607 unsigned int bb_index;
3608 bitmap_iterator bi;
3609 bitmap live = BITMAP_ALLOC (&df_bitmap_obstack);
3610 bitmap do_not_gen = BITMAP_ALLOC (&df_bitmap_obstack);
3611 bitmap artificial_uses = BITMAP_ALLOC (&df_bitmap_obstack);
3612
3613 #ifdef REG_DEAD_DEBUGGING
3614 if (dump_file)
3615 print_rtl_with_bb (dump_file, get_insns());
3616 #endif
3617
3618 EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
3619 {
3620 df_note_bb_compute (bb_index, live, do_not_gen, artificial_uses);
3621 }
3622
3623 BITMAP_FREE (live);
3624 BITMAP_FREE (do_not_gen);
3625 BITMAP_FREE (artificial_uses);
3626 }
3627
3628
3629 /* Free all storage associated with the problem. */
3630
3631 static void
3632 df_note_free (void)
3633 {
3634 free (df_note);
3635 }
3636
3637
3638 /* All of the information associated every instance of the problem. */
3639
3640 static struct df_problem problem_NOTE =
3641 {
3642 DF_NOTE, /* Problem id. */
3643 DF_NONE, /* Direction. */
3644 df_note_alloc, /* Allocate the problem specific data. */
3645 NULL, /* Reset global information. */
3646 NULL, /* Free basic block info. */
3647 df_note_compute, /* Local compute function. */
3648 NULL, /* Init the solution specific data. */
3649 NULL, /* Iterative solver. */
3650 NULL, /* Confluence operator 0. */
3651 NULL, /* Confluence operator n. */
3652 NULL, /* Transfer function. */
3653 NULL, /* Finalize function. */
3654 df_note_free, /* Free all of the problem information. */
3655 df_note_free, /* Remove this problem from the stack of dataflow problems. */
3656 NULL, /* Debugging. */
3657 NULL, /* Debugging start block. */
3658 NULL, /* Debugging end block. */
3659 NULL, /* Incremental solution verify start. */
3660 NULL, /* Incremental solution verify end. */
3661 &problem_LR, /* Dependent problem. */
3662 TV_DF_NOTE, /* Timing variable. */
3663 false /* Reset blocks on dropping out of blocks_to_analyze. */
3664 };
3665
3666
3667 /* Create a new DATAFLOW instance and add it to an existing instance
3668 of DF. The returned structure is what is used to get at the
3669 solution. */
3670
3671 void
3672 df_note_add_problem (void)
3673 {
3674 df_add_problem (&problem_NOTE);
3675 }
3676
3677
3678
3679
3680 /*----------------------------------------------------------------------------
3681 Functions for simulating the effects of single insns.
3682
3683 You can either simulate in the forwards direction, starting from
3684 the top of a block or the backwards direction from the end of the
3685 block. The main difference is that if you go forwards, the uses
3686 are examined first then the defs, and if you go backwards, the defs
3687 are examined first then the uses.
3688
3689 If you start at the top of the block, use one of DF_LIVE_IN or
3690 DF_LR_IN. If you start at the bottom of the block use one of
3691 DF_LIVE_OUT or DF_LR_OUT. BE SURE TO PASS A COPY OF THESE SETS,
3692 THEY WILL BE DESTROYED.
3693 ----------------------------------------------------------------------------*/
3694
3695
3696 /* Find the set of DEFs for INSN. */
3697
3698 void
3699 df_simulate_find_defs (rtx insn, bitmap defs)
3700 {
3701 df_ref *def_rec;
3702 unsigned int uid = INSN_UID (insn);
3703
3704 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
3705 {
3706 df_ref def = *def_rec;
3707 /* If the def is to only part of the reg, it does
3708 not kill the other defs that reach here. */
3709 if (!(DF_REF_FLAGS (def) & (DF_REF_PARTIAL | DF_REF_CONDITIONAL)))
3710 bitmap_set_bit (defs, DF_REF_REGNO (def));
3711 }
3712 }
3713
3714
3715 /* Simulate the effects of the defs of INSN on LIVE. */
3716
3717 void
3718 df_simulate_defs (rtx insn, bitmap live)
3719 {
3720 df_ref *def_rec;
3721 unsigned int uid = INSN_UID (insn);
3722
3723 for (def_rec = DF_INSN_UID_DEFS (uid); *def_rec; def_rec++)
3724 {
3725 df_ref def = *def_rec;
3726 unsigned int dregno = DF_REF_REGNO (def);
3727
3728 /* If the def is to only part of the reg, it does
3729 not kill the other defs that reach here. */
3730 if (!(DF_REF_FLAGS (def) & (DF_REF_PARTIAL | DF_REF_CONDITIONAL)))
3731 bitmap_clear_bit (live, dregno);
3732 }
3733 }
3734
3735
3736 /* Simulate the effects of the uses of INSN on LIVE. */
3737
3738 void
3739 df_simulate_uses (rtx insn, bitmap live)
3740 {
3741 df_ref *use_rec;
3742 unsigned int uid = INSN_UID (insn);
3743
3744 for (use_rec = DF_INSN_UID_USES (uid); *use_rec; use_rec++)
3745 {
3746 df_ref use = *use_rec;
3747 /* Add use to set of uses in this BB. */
3748 bitmap_set_bit (live, DF_REF_REGNO (use));
3749 }
3750 }
3751
3752
3753 /* Add back the always live regs in BB to LIVE. */
3754
3755 static inline void
3756 df_simulate_fixup_sets (basic_block bb, bitmap live)
3757 {
3758 /* These regs are considered always live so if they end up dying
3759 because of some def, we need to bring the back again. */
3760 if (bb_has_eh_pred (bb))
3761 bitmap_ior_into (live, df->eh_block_artificial_uses);
3762 else
3763 bitmap_ior_into (live, df->regular_block_artificial_uses);
3764 }
3765
3766
3767 /*----------------------------------------------------------------------------
3768 The following three functions are used only for BACKWARDS scanning:
3769 i.e. they process the defs before the uses.
3770
3771 df_simulate_initialize_backwards should be called first with a
3772 bitvector copyied from the DF_LIVE_OUT or DF_LR_OUT. Then
3773 df_simulate_one_insn_backwards should be called for each insn in
3774 the block, starting with the last on. Finally,
3775 df_simulate_finalize_backwards can be called to get a new value
3776 of the sets at the top of the block (this is rarely used).
3777 ----------------------------------------------------------------------------*/
3778
3779 /* Apply the artificial uses and defs at the end of BB in a backwards
3780 direction. */
3781
3782 void
3783 df_simulate_initialize_backwards (basic_block bb, bitmap live)
3784 {
3785 df_ref *def_rec;
3786 df_ref *use_rec;
3787 int bb_index = bb->index;
3788
3789 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
3790 {
3791 df_ref def = *def_rec;
3792 if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
3793 bitmap_clear_bit (live, DF_REF_REGNO (def));
3794 }
3795
3796 for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
3797 {
3798 df_ref use = *use_rec;
3799 if ((DF_REF_FLAGS (use) & DF_REF_AT_TOP) == 0)
3800 bitmap_set_bit (live, DF_REF_REGNO (use));
3801 }
3802 }
3803
3804
3805 /* Simulate the backwards effects of INSN on the bitmap LIVE. */
3806
3807 void
3808 df_simulate_one_insn_backwards (basic_block bb, rtx insn, bitmap live)
3809 {
3810 if (! INSN_P (insn))
3811 return;
3812
3813 df_simulate_defs (insn, live);
3814 df_simulate_uses (insn, live);
3815 df_simulate_fixup_sets (bb, live);
3816 }
3817
3818
3819 /* Apply the artificial uses and defs at the top of BB in a backwards
3820 direction. */
3821
3822 void
3823 df_simulate_finalize_backwards (basic_block bb, bitmap live)
3824 {
3825 df_ref *def_rec;
3826 #ifdef EH_USES
3827 df_ref *use_rec;
3828 #endif
3829 int bb_index = bb->index;
3830
3831 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
3832 {
3833 df_ref def = *def_rec;
3834 if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
3835 bitmap_clear_bit (live, DF_REF_REGNO (def));
3836 }
3837
3838 #ifdef EH_USES
3839 for (use_rec = df_get_artificial_uses (bb_index); *use_rec; use_rec++)
3840 {
3841 df_ref use = *use_rec;
3842 if (DF_REF_FLAGS (use) & DF_REF_AT_TOP)
3843 bitmap_set_bit (live, DF_REF_REGNO (use));
3844 }
3845 #endif
3846 }
3847 /*----------------------------------------------------------------------------
3848 The following three functions are used only for FORWARDS scanning:
3849 i.e. they process the defs and the REG_DEAD and REG_UNUSED notes.
3850 Thus it is important to add the DF_NOTES problem to the stack of
3851 problems computed before using these functions.
3852
3853 df_simulate_initialize_forwards should be called first with a
3854 bitvector copyied from the DF_LIVE_IN or DF_LR_IN. Then
3855 df_simulate_one_insn_forwards should be called for each insn in
3856 the block, starting with the last on. Finally,
3857 df_simulate_finalize_forwards can be called to get a new value
3858 of the sets at the bottom of the block (this is rarely used).
3859 ----------------------------------------------------------------------------*/
3860
3861 /* Apply the artificial uses and defs at the top of BB in a backwards
3862 direction. */
3863
3864 void
3865 df_simulate_initialize_forwards (basic_block bb, bitmap live)
3866 {
3867 df_ref *def_rec;
3868 int bb_index = bb->index;
3869
3870 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
3871 {
3872 df_ref def = *def_rec;
3873 if (DF_REF_FLAGS (def) & DF_REF_AT_TOP)
3874 bitmap_clear_bit (live, DF_REF_REGNO (def));
3875 }
3876 }
3877
3878 /* Simulate the backwards effects of INSN on the bitmap LIVE. */
3879
3880 void
3881 df_simulate_one_insn_forwards (basic_block bb, rtx insn, bitmap live)
3882 {
3883 rtx link;
3884 if (! INSN_P (insn))
3885 return;
3886
3887 /* Make sure that the DF_NOTES really is an active df problem. */
3888 gcc_assert (df_note);
3889
3890 df_simulate_defs (insn, live);
3891
3892 /* Clear all of the registers that go dead. */
3893 for (link = REG_NOTES (insn); link; link = XEXP (link, 1))
3894 {
3895 switch (REG_NOTE_KIND (link))
3896 case REG_DEAD:
3897 case REG_UNUSED:
3898 {
3899 rtx reg = XEXP (link, 0);
3900 int regno = REGNO (reg);
3901 if (regno < FIRST_PSEUDO_REGISTER)
3902 {
3903 int n = hard_regno_nregs[regno][GET_MODE (reg)];
3904 while (--n >= 0)
3905 bitmap_clear_bit (live, regno + n);
3906 }
3907 else
3908 bitmap_clear_bit (live, regno);
3909 break;
3910 default:
3911 break;
3912 }
3913 }
3914 df_simulate_fixup_sets (bb, live);
3915 }
3916
3917
3918 /* Apply the artificial uses and defs at the end of BB in a backwards
3919 direction. */
3920
3921 void
3922 df_simulate_finalize_forwards (basic_block bb, bitmap live)
3923 {
3924 df_ref *def_rec;
3925 int bb_index = bb->index;
3926
3927 for (def_rec = df_get_artificial_defs (bb_index); *def_rec; def_rec++)
3928 {
3929 df_ref def = *def_rec;
3930 if ((DF_REF_FLAGS (def) & DF_REF_AT_TOP) == 0)
3931 bitmap_clear_bit (live, DF_REF_REGNO (def));
3932 }
3933 }
3934
3935