aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.9/gcc/sched-ebb.c
blob: ce172142a133a005ad890bd0b7eb86e9fe91c44f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
/* Instruction scheduling pass.
   Copyright (C) 1992-2014 Free Software Foundation, Inc.
   Contributed by Michael Tiemann (tiemann@cygnus.com) Enhanced by,
   and currently maintained by, Jim Wilson (wilson@cygnus.com)

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "diagnostic-core.h"
#include "rtl.h"
#include "tm_p.h"
#include "hard-reg-set.h"
#include "regs.h"
#include "function.h"
#include "flags.h"
#include "insn-config.h"
#include "insn-attr.h"
#include "except.h"
#include "recog.h"
#include "params.h"
#include "sched-int.h"
#include "target.h"


#ifdef INSN_SCHEDULING

/* The number of insns to be scheduled in total.  */
static int rgn_n_insns;

/* The number of insns scheduled so far.  */
static int sched_rgn_n_insns;

/* Set of blocks, that already have their dependencies calculated.  */
static bitmap_head dont_calc_deps;

/* Last basic block in current ebb.  */
static basic_block last_bb;

/* Implementations of the sched_info functions for region scheduling.  */
static void init_ready_list (void);
static void begin_schedule_ready (rtx);
static int schedule_more_p (void);
static const char *ebb_print_insn (const_rtx, int);
static int rank (rtx, rtx);
static int ebb_contributes_to_priority (rtx, rtx);
static basic_block earliest_block_with_similiar_load (basic_block, rtx);
static void add_deps_for_risky_insns (rtx, rtx);
static void debug_ebb_dependencies (rtx, rtx);

static void ebb_add_remove_insn (rtx, int);
static void ebb_add_block (basic_block, basic_block);
static basic_block advance_target_bb (basic_block, rtx);
static void ebb_fix_recovery_cfg (int, int, int);

/* Allocate memory and store the state of the frontend.  Return the allocated
   memory.  */
static void *
save_ebb_state (void)
{
  int *p = XNEW (int);
  *p = sched_rgn_n_insns;
  return p;
}

/* Restore the state of the frontend from P_, then free it.  */
static void
restore_ebb_state (void *p_)
{
  int *p = (int *)p_;
  sched_rgn_n_insns = *p;
  free (p_);
}

/* Return nonzero if there are more insns that should be scheduled.  */

static int
schedule_more_p (void)
{
  return sched_rgn_n_insns < rgn_n_insns;
}

/* Print dependency information about ebb between HEAD and TAIL.  */
static void
debug_ebb_dependencies (rtx head, rtx tail)
{
  fprintf (sched_dump,
	   ";;   --------------- forward dependences: ------------ \n");

  fprintf (sched_dump, "\n;;   --- EBB Dependences --- from bb%d to bb%d \n",
	   BLOCK_NUM (head), BLOCK_NUM (tail));

  debug_dependencies (head, tail);
}

/* Add all insns that are initially ready to the ready list READY.  Called
   once before scheduling a set of insns.  */

static void
init_ready_list (void)
{
  int n = 0;
  rtx prev_head = current_sched_info->prev_head;
  rtx next_tail = current_sched_info->next_tail;
  rtx insn;

  sched_rgn_n_insns = 0;

  /* Print debugging information.  */
  if (sched_verbose >= 5)
    debug_ebb_dependencies (NEXT_INSN (prev_head), PREV_INSN (next_tail));

  /* Initialize ready list with all 'ready' insns in target block.
     Count number of insns in the target block being scheduled.  */
  for (insn = NEXT_INSN (prev_head); insn != next_tail; insn = NEXT_INSN (insn))
    {
      try_ready (insn);
      n++;
    }

  gcc_assert (n == rgn_n_insns);
}

/* INSN is being scheduled after LAST.  Update counters.  */
static void
begin_schedule_ready (rtx insn ATTRIBUTE_UNUSED)
{
  sched_rgn_n_insns++;
}

/* INSN is being moved to its place in the schedule, after LAST.  */
static void
begin_move_insn (rtx insn, rtx last)
{
  if (BLOCK_FOR_INSN (insn) == last_bb
      /* INSN is a jump in the last block, ...  */
      && control_flow_insn_p (insn)
      /* that is going to be moved over some instructions.  */
      && last != PREV_INSN (insn))
    {
      edge e;
      basic_block bb;

      /* An obscure special case, where we do have partially dead
	 instruction scheduled after last control flow instruction.
	 In this case we can create new basic block.  It is
	 always exactly one basic block last in the sequence.  */

      e = find_fallthru_edge (last_bb->succs);

      gcc_checking_assert (!e || !(e->flags & EDGE_COMPLEX));

      gcc_checking_assert (BLOCK_FOR_INSN (insn) == last_bb
			   && !IS_SPECULATION_CHECK_P (insn)
			   && BB_HEAD (last_bb) != insn
			   && BB_END (last_bb) == insn);

      {
	rtx x;

	x = NEXT_INSN (insn);
	if (e)
	  gcc_checking_assert (NOTE_P (x) || LABEL_P (x));
	else
	  gcc_checking_assert (BARRIER_P (x));
      }

      if (e)
	{
	  bb = split_edge (e);
	  gcc_assert (NOTE_INSN_BASIC_BLOCK_P (BB_END (bb)));
	}
      else
	{
	  /* Create an empty unreachable block after the INSN.  */
	  rtx next = NEXT_INSN (insn);
	  if (next && BARRIER_P (next))
	    next = NEXT_INSN (next);
	  bb = create_basic_block (next, NULL_RTX, last_bb);
	}

      /* split_edge () creates BB before E->DEST.  Keep in mind, that
	 this operation extends scheduling region till the end of BB.
	 Hence, we need to shift NEXT_TAIL, so haifa-sched.c won't go out
	 of the scheduling region.  */
      current_sched_info->next_tail = NEXT_INSN (BB_END (bb));
      gcc_assert (current_sched_info->next_tail);

      /* Append new basic block to the end of the ebb.  */
      sched_init_only_bb (bb, last_bb);
      gcc_assert (last_bb == bb);
    }
}

/* Return a string that contains the insn uid and optionally anything else
   necessary to identify this insn in an output.  It's valid to use a
   static buffer for this.  The ALIGNED parameter should cause the string
   to be formatted so that multiple output lines will line up nicely.  */

static const char *
ebb_print_insn (const_rtx insn, int aligned ATTRIBUTE_UNUSED)
{
  static char tmp[80];

  /* '+' before insn means it is a new cycle start.  */
  if (GET_MODE (insn) == TImode)
    sprintf (tmp, "+ %4d", INSN_UID (insn));
  else
    sprintf (tmp, "  %4d", INSN_UID (insn));

  return tmp;
}

/* Compare priority of two insns.  Return a positive number if the second
   insn is to be preferred for scheduling, and a negative one if the first
   is to be preferred.  Zero if they are equally good.  */

static int
rank (rtx insn1, rtx insn2)
{
  basic_block bb1 = BLOCK_FOR_INSN (insn1);
  basic_block bb2 = BLOCK_FOR_INSN (insn2);

  if (bb1->count > bb2->count
      || bb1->frequency > bb2->frequency)
    return -1;
  if (bb1->count < bb2->count
      || bb1->frequency < bb2->frequency)
    return 1;
  return 0;
}

/* NEXT is an instruction that depends on INSN (a backward dependence);
   return nonzero if we should include this dependence in priority
   calculations.  */

static int
ebb_contributes_to_priority (rtx next ATTRIBUTE_UNUSED,
                             rtx insn ATTRIBUTE_UNUSED)
{
  return 1;
}

 /* INSN is a JUMP_INSN.  Store the set of registers that
    must be considered as used by this jump in USED.  */

void
ebb_compute_jump_reg_dependencies (rtx insn, regset used)
{
  basic_block b = BLOCK_FOR_INSN (insn);
  edge e;
  edge_iterator ei;

  FOR_EACH_EDGE (e, ei, b->succs)
    if ((e->flags & EDGE_FALLTHRU) == 0)
      bitmap_ior_into (used, df_get_live_in (e->dest));
}

/* Used in schedule_insns to initialize current_sched_info for scheduling
   regions (or single basic blocks).  */

static struct common_sched_info_def ebb_common_sched_info;

static struct sched_deps_info_def ebb_sched_deps_info =
  {
    ebb_compute_jump_reg_dependencies,
    NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
    NULL,
    1, 0, 0
  };

static struct haifa_sched_info ebb_sched_info =
{
  init_ready_list,
  NULL,
  schedule_more_p,
  NULL,
  rank,
  ebb_print_insn,
  ebb_contributes_to_priority,
  NULL, /* insn_finishes_block_p */

  NULL, NULL,
  NULL, NULL,
  1, 0,

  ebb_add_remove_insn,
  begin_schedule_ready,
  begin_move_insn,
  advance_target_bb,

  save_ebb_state,
  restore_ebb_state,

  SCHED_EBB
  /* We can create new blocks in begin_schedule_ready ().  */
  | NEW_BBS
};

/* Returns the earliest block in EBB currently being processed where a
   "similar load" 'insn2' is found, and hence LOAD_INSN can move
   speculatively into the found block.  All the following must hold:

   (1) both loads have 1 base register (PFREE_CANDIDATEs).
   (2) load_insn and load2 have a def-use dependence upon
   the same insn 'insn1'.

   From all these we can conclude that the two loads access memory
   addresses that differ at most by a constant, and hence if moving
   load_insn would cause an exception, it would have been caused by
   load2 anyhow.

   The function uses list (given by LAST_BLOCK) of already processed
   blocks in EBB.  The list is formed in `add_deps_for_risky_insns'.  */

static basic_block
earliest_block_with_similiar_load (basic_block last_block, rtx load_insn)
{
  sd_iterator_def back_sd_it;
  dep_t back_dep;
  basic_block bb, earliest_block = NULL;

  FOR_EACH_DEP (load_insn, SD_LIST_BACK, back_sd_it, back_dep)
    {
      rtx insn1 = DEP_PRO (back_dep);

      if (DEP_TYPE (back_dep) == REG_DEP_TRUE)
	/* Found a DEF-USE dependence (insn1, load_insn).  */
	{
	  sd_iterator_def fore_sd_it;
	  dep_t fore_dep;

	  FOR_EACH_DEP (insn1, SD_LIST_FORW, fore_sd_it, fore_dep)
	    {
	      rtx insn2 = DEP_CON (fore_dep);
	      basic_block insn2_block = BLOCK_FOR_INSN (insn2);

	      if (DEP_TYPE (fore_dep) == REG_DEP_TRUE)
		{
		  if (earliest_block != NULL
		      && earliest_block->index < insn2_block->index)
		    continue;

		  /* Found a DEF-USE dependence (insn1, insn2).  */
		  if (haifa_classify_insn (insn2) != PFREE_CANDIDATE)
		    /* insn2 not guaranteed to be a 1 base reg load.  */
		    continue;

		  for (bb = last_block; bb; bb = (basic_block) bb->aux)
		    if (insn2_block == bb)
		      break;

		  if (!bb)
		    /* insn2 is the similar load.  */
		    earliest_block = insn2_block;
		}
	    }
	}
    }

  return earliest_block;
}

/* The following function adds dependencies between jumps and risky
   insns in given ebb.  */

static void
add_deps_for_risky_insns (rtx head, rtx tail)
{
  rtx insn, prev;
  int classification;
  rtx last_jump = NULL_RTX;
  rtx next_tail = NEXT_INSN (tail);
  basic_block last_block = NULL, bb;

  for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
    {
      add_delay_dependencies (insn);
      if (control_flow_insn_p (insn))
	{
	  bb = BLOCK_FOR_INSN (insn);
	  bb->aux = last_block;
	  last_block = bb;
	  /* Ensure blocks stay in the same order.  */
	  if (last_jump)
	    add_dependence (insn, last_jump, REG_DEP_ANTI);
	  last_jump = insn;
	}
      else if (INSN_P (insn) && last_jump != NULL_RTX)
	{
	  classification = haifa_classify_insn (insn);
	  prev = last_jump;

	  switch (classification)
	    {
	    case PFREE_CANDIDATE:
	      if (flag_schedule_speculative_load)
		{
		  bb = earliest_block_with_similiar_load (last_block, insn);
		  if (bb)
		    {
		      bb = (basic_block) bb->aux;
		      if (!bb)
			break;
		      prev = BB_END (bb);
		    }
		}
	      /* Fall through.  */
	    case TRAP_RISKY:
	    case IRISKY:
	    case PRISKY_CANDIDATE:
	      /* ??? We could implement better checking PRISKY_CANDIDATEs
		 analogous to sched-rgn.c.  */
	      /* We can not change the mode of the backward
		 dependency because REG_DEP_ANTI has the lowest
		 rank.  */
	      if (! sched_insns_conditions_mutex_p (insn, prev))
		{
		  if ((current_sched_info->flags & DO_SPECULATION)
		      && (spec_info->mask & BEGIN_CONTROL))
		    {
		      dep_def _dep, *dep = &_dep;

		      init_dep (dep, prev, insn, REG_DEP_ANTI);

		      if (current_sched_info->flags & USE_DEPS_LIST)
			{
			  DEP_STATUS (dep) = set_dep_weak (DEP_ANTI, BEGIN_CONTROL,
							   MAX_DEP_WEAK);

			}
		      sd_add_or_update_dep (dep, false);
		    }
		  else
		    add_dependence (insn, prev, REG_DEP_CONTROL);
		}

	      break;

	    default:
	      break;
	    }
	}
    }
  /* Maintain the invariant that bb->aux is clear after use.  */
  while (last_block)
    {
      bb = (basic_block) last_block->aux;
      last_block->aux = NULL;
      last_block = bb;
    }
}

/* Schedule a single extended basic block, defined by the boundaries
   HEAD and TAIL.

   We change our expectations about scheduler behaviour depending on
   whether MODULO_SCHEDULING is true.  If it is, we expect that the
   caller has already called set_modulo_params and created delay pairs
   as appropriate.  If the modulo schedule failed, we return
   NULL_RTX.  */

basic_block
schedule_ebb (rtx head, rtx tail, bool modulo_scheduling)
{
  basic_block first_bb, target_bb;
  struct deps_desc tmp_deps;
  bool success;

  /* Blah.  We should fix the rest of the code not to get confused by
     a note or two.  */
  while (head != tail)
    {
      if (NOTE_P (head) || DEBUG_INSN_P (head))
	head = NEXT_INSN (head);
      else if (NOTE_P (tail) || DEBUG_INSN_P (tail))
	tail = PREV_INSN (tail);
      else if (LABEL_P (head))
	head = NEXT_INSN (head);
      else
	break;
    }

  first_bb = BLOCK_FOR_INSN (head);
  last_bb = BLOCK_FOR_INSN (tail);

  if (no_real_insns_p (head, tail))
    return BLOCK_FOR_INSN (tail);

  gcc_assert (INSN_P (head) && INSN_P (tail));

  if (!bitmap_bit_p (&dont_calc_deps, first_bb->index))
    {
      init_deps_global ();

      /* Compute dependencies.  */
      init_deps (&tmp_deps, false);
      sched_analyze (&tmp_deps, head, tail);
      free_deps (&tmp_deps);

      add_deps_for_risky_insns (head, tail);

      if (targetm.sched.dependencies_evaluation_hook)
        targetm.sched.dependencies_evaluation_hook (head, tail);

      finish_deps_global ();
    }
  else
    /* Only recovery blocks can have their dependencies already calculated,
       and they always are single block ebbs.  */
    gcc_assert (first_bb == last_bb);

  /* Set priorities.  */
  current_sched_info->sched_max_insns_priority = 0;
  rgn_n_insns = set_priorities (head, tail);
  current_sched_info->sched_max_insns_priority++;

  current_sched_info->prev_head = PREV_INSN (head);
  current_sched_info->next_tail = NEXT_INSN (tail);

  remove_notes (head, tail);

  unlink_bb_notes (first_bb, last_bb);

  target_bb = first_bb;

  /* Make ready list big enough to hold all the instructions from the ebb.  */
  sched_extend_ready_list (rgn_n_insns);
  success = schedule_block (&target_bb, NULL);
  gcc_assert (success || modulo_scheduling);

  /* Free ready list.  */
  sched_finish_ready_list ();

  /* We might pack all instructions into fewer blocks,
     so we may made some of them empty.  Can't assert (b == last_bb).  */

  /* Sanity check: verify that all region insns were scheduled.  */
  gcc_assert (modulo_scheduling || sched_rgn_n_insns == rgn_n_insns);

  /* Free dependencies.  */
  sched_free_deps (current_sched_info->head, current_sched_info->tail, true);

  gcc_assert (haifa_recovery_bb_ever_added_p
	      || deps_pools_are_empty_p ());

  if (EDGE_COUNT (last_bb->preds) == 0)
    /* LAST_BB is unreachable.  */
    {
      gcc_assert (first_bb != last_bb
		  && EDGE_COUNT (last_bb->succs) == 0);
      last_bb = last_bb->prev_bb;
      delete_basic_block (last_bb->next_bb);
    }

  return success ? last_bb : NULL;
}

/* Perform initializations before running schedule_ebbs or a single
   schedule_ebb.  */
void
schedule_ebbs_init (void)
{
  /* Setup infos.  */
  {
    memcpy (&ebb_common_sched_info, &haifa_common_sched_info,
	    sizeof (ebb_common_sched_info));

    ebb_common_sched_info.fix_recovery_cfg = ebb_fix_recovery_cfg;
    ebb_common_sched_info.add_block = ebb_add_block;
    ebb_common_sched_info.sched_pass_id = SCHED_EBB_PASS;

    common_sched_info = &ebb_common_sched_info;
    sched_deps_info = &ebb_sched_deps_info;
    current_sched_info = &ebb_sched_info;
  }

  haifa_sched_init ();

  compute_bb_for_insn ();

  /* Initialize DONT_CALC_DEPS and ebb-{start, end} markers.  */
  bitmap_initialize (&dont_calc_deps, 0);
  bitmap_clear (&dont_calc_deps);
}

/* Perform cleanups after scheduling using schedules_ebbs or schedule_ebb.  */
void
schedule_ebbs_finish (void)
{
  bitmap_clear (&dont_calc_deps);

  /* Reposition the prologue and epilogue notes in case we moved the
     prologue/epilogue insns.  */
  if (reload_completed)
    reposition_prologue_and_epilogue_notes ();

  haifa_sched_finish ();
}

/* The main entry point in this file.  */

void
schedule_ebbs (void)
{
  basic_block bb;
  int probability_cutoff;
  rtx tail;

  /* Taking care of this degenerate case makes the rest of
     this code simpler.  */
  if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS)
    return;

  if (profile_info && flag_branch_probabilities)
    probability_cutoff = PARAM_VALUE (TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK);
  else
    probability_cutoff = PARAM_VALUE (TRACER_MIN_BRANCH_PROBABILITY);
  probability_cutoff = REG_BR_PROB_BASE / 100 * probability_cutoff;

  schedule_ebbs_init ();

  /* Schedule every region in the subroutine.  */
  FOR_EACH_BB_FN (bb, cfun)
    {
      rtx head = BB_HEAD (bb);

      if (bb->flags & BB_DISABLE_SCHEDULE)
	continue;

      for (;;)
	{
	  edge e;
	  tail = BB_END (bb);
	  if (bb->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun)
	      || LABEL_P (BB_HEAD (bb->next_bb)))
	    break;
	  e = find_fallthru_edge (bb->succs);
	  if (! e)
	    break;
	  if (e->probability <= probability_cutoff)
	    break;
	  if (e->dest->flags & BB_DISABLE_SCHEDULE)
 	    break;
	  bb = bb->next_bb;
	}

      bb = schedule_ebb (head, tail, false);
    }
  schedule_ebbs_finish ();
}

/* INSN has been added to/removed from current ebb.  */
static void
ebb_add_remove_insn (rtx insn ATTRIBUTE_UNUSED, int remove_p)
{
  if (!remove_p)
    rgn_n_insns++;
  else
    rgn_n_insns--;
}

/* BB was added to ebb after AFTER.  */
static void
ebb_add_block (basic_block bb, basic_block after)
{
  /* Recovery blocks are always bounded by BARRIERS,
     therefore, they always form single block EBB,
     therefore, we can use rec->index to identify such EBBs.  */
  if (after == EXIT_BLOCK_PTR_FOR_FN (cfun))
    bitmap_set_bit (&dont_calc_deps, bb->index);
  else if (after == last_bb)
    last_bb = bb;
}

/* Return next block in ebb chain.  For parameter meaning please refer to
   sched-int.h: struct sched_info: advance_target_bb.  */
static basic_block
advance_target_bb (basic_block bb, rtx insn)
{
  if (insn)
    {
      if (BLOCK_FOR_INSN (insn) != bb
	  && control_flow_insn_p (insn)
	  /* We handle interblock movement of the speculation check
	     or over a speculation check in
	     haifa-sched.c: move_block_after_check ().  */
	  && !IS_SPECULATION_BRANCHY_CHECK_P (insn)
	  && !IS_SPECULATION_BRANCHY_CHECK_P (BB_END (bb)))
	{
	  /* Assert that we don't move jumps across blocks.  */
	  gcc_assert (!control_flow_insn_p (BB_END (bb))
		      && NOTE_INSN_BASIC_BLOCK_P (BB_HEAD (bb->next_bb)));
	  return bb;
	}
      else
	return 0;
    }
  else
    /* Return next non empty block.  */
    {
      do
	{
	  gcc_assert (bb != last_bb);

	  bb = bb->next_bb;
	}
      while (bb_note (bb) == BB_END (bb));

      return bb;
    }
}

/* Fix internal data after interblock movement of jump instruction.
   For parameter meaning please refer to
   sched-int.h: struct sched_info: fix_recovery_cfg.  */
static void
ebb_fix_recovery_cfg (int bbi ATTRIBUTE_UNUSED, int jump_bbi,
		      int jump_bb_nexti)
{
  gcc_assert (last_bb->index != bbi);

  if (jump_bb_nexti == last_bb->index)
    last_bb = BASIC_BLOCK_FOR_FN (cfun, jump_bbi);
}

#endif /* INSN_SCHEDULING */