xref: /dragonfly/contrib/gcc-4.7/gcc/sched-ebb.c (revision ed36d35d)
1 /* Instruction scheduling pass.
2    Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3    2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
4    Free Software Foundation, Inc.
5    Contributed by Michael Tiemann (tiemann@cygnus.com) Enhanced by,
6    and currently maintained by, Jim Wilson (wilson@cygnus.com)
7 
8 This file is part of GCC.
9 
10 GCC is free software; you can redistribute it and/or modify it under
11 the terms of the GNU General Public License as published by the Free
12 Software Foundation; either version 3, or (at your option) any later
13 version.
14 
15 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
16 WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
18 for more details.
19 
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3.  If not see
22 <http://www.gnu.org/licenses/>.  */
23 
24 #include "config.h"
25 #include "system.h"
26 #include "coretypes.h"
27 #include "tm.h"
28 #include "diagnostic-core.h"
29 #include "rtl.h"
30 #include "tm_p.h"
31 #include "hard-reg-set.h"
32 #include "regs.h"
33 #include "function.h"
34 #include "flags.h"
35 #include "insn-config.h"
36 #include "insn-attr.h"
37 #include "except.h"
38 #include "recog.h"
39 #include "cfglayout.h"
40 #include "params.h"
41 #include "sched-int.h"
42 #include "target.h"
43 #include "output.h"
44 
45 
46 #ifdef INSN_SCHEDULING
47 
48 /* The number of insns to be scheduled in total.  */
49 static int rgn_n_insns;
50 
51 /* The number of insns scheduled so far.  */
52 static int sched_rgn_n_insns;
53 
54 /* Set of blocks, that already have their dependencies calculated.  */
55 static bitmap_head dont_calc_deps;
56 
57 /* Last basic block in current ebb.  */
58 static basic_block last_bb;
59 
60 /* Implementations of the sched_info functions for region scheduling.  */
61 static void init_ready_list (void);
62 static void begin_schedule_ready (rtx);
63 static int schedule_more_p (void);
64 static const char *ebb_print_insn (const_rtx, int);
65 static int rank (rtx, rtx);
66 static int ebb_contributes_to_priority (rtx, rtx);
67 static basic_block earliest_block_with_similiar_load (basic_block, rtx);
68 static void add_deps_for_risky_insns (rtx, rtx);
69 static void debug_ebb_dependencies (rtx, rtx);
70 
71 static void ebb_add_remove_insn (rtx, int);
72 static void ebb_add_block (basic_block, basic_block);
73 static basic_block advance_target_bb (basic_block, rtx);
74 static void ebb_fix_recovery_cfg (int, int, int);
75 
76 /* Allocate memory and store the state of the frontend.  Return the allocated
77    memory.  */
78 static void *
79 save_ebb_state (void)
80 {
81   int *p = XNEW (int);
82   *p = sched_rgn_n_insns;
83   return p;
84 }
85 
86 /* Restore the state of the frontend from P_, then free it.  */
87 static void
88 restore_ebb_state (void *p_)
89 {
90   int *p = (int *)p_;
91   sched_rgn_n_insns = *p;
92   free (p_);
93 }
94 
95 /* Return nonzero if there are more insns that should be scheduled.  */
96 
97 static int
98 schedule_more_p (void)
99 {
100   return sched_rgn_n_insns < rgn_n_insns;
101 }
102 
103 /* Print dependency information about ebb between HEAD and TAIL.  */
104 static void
105 debug_ebb_dependencies (rtx head, rtx tail)
106 {
107   fprintf (sched_dump,
108 	   ";;   --------------- forward dependences: ------------ \n");
109 
110   fprintf (sched_dump, "\n;;   --- EBB Dependences --- from bb%d to bb%d \n",
111 	   BLOCK_NUM (head), BLOCK_NUM (tail));
112 
113   debug_dependencies (head, tail);
114 }
115 
116 /* Add all insns that are initially ready to the ready list READY.  Called
117    once before scheduling a set of insns.  */
118 
119 static void
120 init_ready_list (void)
121 {
122   int n = 0;
123   rtx prev_head = current_sched_info->prev_head;
124   rtx next_tail = current_sched_info->next_tail;
125   rtx insn;
126 
127   sched_rgn_n_insns = 0;
128 
129   /* Print debugging information.  */
130   if (sched_verbose >= 5)
131     debug_ebb_dependencies (NEXT_INSN (prev_head), PREV_INSN (next_tail));
132 
133   /* Initialize ready list with all 'ready' insns in target block.
134      Count number of insns in the target block being scheduled.  */
135   for (insn = NEXT_INSN (prev_head); insn != next_tail; insn = NEXT_INSN (insn))
136     {
137       try_ready (insn);
138       n++;
139     }
140 
141   gcc_assert (n == rgn_n_insns);
142 }
143 
144 /* INSN is being scheduled after LAST.  Update counters.  */
145 static void
146 begin_schedule_ready (rtx insn ATTRIBUTE_UNUSED)
147 {
148   sched_rgn_n_insns++;
149 }
150 
151 /* INSN is being moved to its place in the schedule, after LAST.  */
152 static void
153 begin_move_insn (rtx insn, rtx last)
154 {
155   if (BLOCK_FOR_INSN (insn) == last_bb
156       /* INSN is a jump in the last block, ...  */
157       && control_flow_insn_p (insn)
158       /* that is going to be moved over some instructions.  */
159       && last != PREV_INSN (insn))
160     {
161       edge e;
162       basic_block bb;
163 
164       /* An obscure special case, where we do have partially dead
165 	 instruction scheduled after last control flow instruction.
166 	 In this case we can create new basic block.  It is
167 	 always exactly one basic block last in the sequence.  */
168 
169       e = find_fallthru_edge (last_bb->succs);
170 
171       gcc_checking_assert (!e || !(e->flags & EDGE_COMPLEX));
172 
173       gcc_checking_assert (BLOCK_FOR_INSN (insn) == last_bb
174 			   && !IS_SPECULATION_CHECK_P (insn)
175 			   && BB_HEAD (last_bb) != insn
176 			   && BB_END (last_bb) == insn);
177 
178       {
179 	rtx x;
180 
181 	x = NEXT_INSN (insn);
182 	if (e)
183 	  gcc_checking_assert (NOTE_P (x) || LABEL_P (x));
184 	else
185 	  gcc_checking_assert (BARRIER_P (x));
186       }
187 
188       if (e)
189 	{
190 	  bb = split_edge (e);
191 	  gcc_assert (NOTE_INSN_BASIC_BLOCK_P (BB_END (bb)));
192 	}
193       else
194 	{
195 	  /* Create an empty unreachable block after the INSN.  */
196 	  rtx next = NEXT_INSN (insn);
197 	  if (next && BARRIER_P (next))
198 	    next = NEXT_INSN (next);
199 	  bb = create_basic_block (next, NULL_RTX, last_bb);
200 	}
201 
202       /* split_edge () creates BB before E->DEST.  Keep in mind, that
203 	 this operation extends scheduling region till the end of BB.
204 	 Hence, we need to shift NEXT_TAIL, so haifa-sched.c won't go out
205 	 of the scheduling region.  */
206       current_sched_info->next_tail = NEXT_INSN (BB_END (bb));
207       gcc_assert (current_sched_info->next_tail);
208 
209       /* Append new basic block to the end of the ebb.  */
210       sched_init_only_bb (bb, last_bb);
211       gcc_assert (last_bb == bb);
212     }
213 }
214 
215 /* Return a string that contains the insn uid and optionally anything else
216    necessary to identify this insn in an output.  It's valid to use a
217    static buffer for this.  The ALIGNED parameter should cause the string
218    to be formatted so that multiple output lines will line up nicely.  */
219 
220 static const char *
221 ebb_print_insn (const_rtx insn, int aligned ATTRIBUTE_UNUSED)
222 {
223   static char tmp[80];
224 
225   /* '+' before insn means it is a new cycle start.  */
226   if (GET_MODE (insn) == TImode)
227     sprintf (tmp, "+ %4d", INSN_UID (insn));
228   else
229     sprintf (tmp, "  %4d", INSN_UID (insn));
230 
231   return tmp;
232 }
233 
234 /* Compare priority of two insns.  Return a positive number if the second
235    insn is to be preferred for scheduling, and a negative one if the first
236    is to be preferred.  Zero if they are equally good.  */
237 
238 static int
239 rank (rtx insn1, rtx insn2)
240 {
241   basic_block bb1 = BLOCK_FOR_INSN (insn1);
242   basic_block bb2 = BLOCK_FOR_INSN (insn2);
243 
244   if (bb1->count > bb2->count
245       || bb1->frequency > bb2->frequency)
246     return -1;
247   if (bb1->count < bb2->count
248       || bb1->frequency < bb2->frequency)
249     return 1;
250   return 0;
251 }
252 
253 /* NEXT is an instruction that depends on INSN (a backward dependence);
254    return nonzero if we should include this dependence in priority
255    calculations.  */
256 
257 static int
258 ebb_contributes_to_priority (rtx next ATTRIBUTE_UNUSED,
259                              rtx insn ATTRIBUTE_UNUSED)
260 {
261   return 1;
262 }
263 
264  /* INSN is a JUMP_INSN.  Store the set of registers that
265     must be considered as used by this jump in USED.  */
266 
267 void
268 ebb_compute_jump_reg_dependencies (rtx insn, regset used)
269 {
270   basic_block b = BLOCK_FOR_INSN (insn);
271   edge e;
272   edge_iterator ei;
273 
274   FOR_EACH_EDGE (e, ei, b->succs)
275     if ((e->flags & EDGE_FALLTHRU) == 0)
276       bitmap_ior_into (used, df_get_live_in (e->dest));
277 }
278 
279 /* Used in schedule_insns to initialize current_sched_info for scheduling
280    regions (or single basic blocks).  */
281 
282 static struct common_sched_info_def ebb_common_sched_info;
283 
284 static struct sched_deps_info_def ebb_sched_deps_info =
285   {
286     ebb_compute_jump_reg_dependencies,
287     NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
288     NULL,
289     1, 0, 0
290   };
291 
292 static struct haifa_sched_info ebb_sched_info =
293 {
294   init_ready_list,
295   NULL,
296   schedule_more_p,
297   NULL,
298   rank,
299   ebb_print_insn,
300   ebb_contributes_to_priority,
301   NULL, /* insn_finishes_block_p */
302 
303   NULL, NULL,
304   NULL, NULL,
305   1, 0,
306 
307   ebb_add_remove_insn,
308   begin_schedule_ready,
309   begin_move_insn,
310   advance_target_bb,
311 
312   save_ebb_state,
313   restore_ebb_state,
314 
315   SCHED_EBB
316   /* We can create new blocks in begin_schedule_ready ().  */
317   | NEW_BBS
318 };
319 
320 /* Returns the earliest block in EBB currently being processed where a
321    "similar load" 'insn2' is found, and hence LOAD_INSN can move
322    speculatively into the found block.  All the following must hold:
323 
324    (1) both loads have 1 base register (PFREE_CANDIDATEs).
325    (2) load_insn and load2 have a def-use dependence upon
326    the same insn 'insn1'.
327 
328    From all these we can conclude that the two loads access memory
329    addresses that differ at most by a constant, and hence if moving
330    load_insn would cause an exception, it would have been caused by
331    load2 anyhow.
332 
333    The function uses list (given by LAST_BLOCK) of already processed
334    blocks in EBB.  The list is formed in `add_deps_for_risky_insns'.  */
335 
336 static basic_block
337 earliest_block_with_similiar_load (basic_block last_block, rtx load_insn)
338 {
339   sd_iterator_def back_sd_it;
340   dep_t back_dep;
341   basic_block bb, earliest_block = NULL;
342 
343   FOR_EACH_DEP (load_insn, SD_LIST_BACK, back_sd_it, back_dep)
344     {
345       rtx insn1 = DEP_PRO (back_dep);
346 
347       if (DEP_TYPE (back_dep) == REG_DEP_TRUE)
348 	/* Found a DEF-USE dependence (insn1, load_insn).  */
349 	{
350 	  sd_iterator_def fore_sd_it;
351 	  dep_t fore_dep;
352 
353 	  FOR_EACH_DEP (insn1, SD_LIST_FORW, fore_sd_it, fore_dep)
354 	    {
355 	      rtx insn2 = DEP_CON (fore_dep);
356 	      basic_block insn2_block = BLOCK_FOR_INSN (insn2);
357 
358 	      if (DEP_TYPE (fore_dep) == REG_DEP_TRUE)
359 		{
360 		  if (earliest_block != NULL
361 		      && earliest_block->index < insn2_block->index)
362 		    continue;
363 
364 		  /* Found a DEF-USE dependence (insn1, insn2).  */
365 		  if (haifa_classify_insn (insn2) != PFREE_CANDIDATE)
366 		    /* insn2 not guaranteed to be a 1 base reg load.  */
367 		    continue;
368 
369 		  for (bb = last_block; bb; bb = (basic_block) bb->aux)
370 		    if (insn2_block == bb)
371 		      break;
372 
373 		  if (!bb)
374 		    /* insn2 is the similar load.  */
375 		    earliest_block = insn2_block;
376 		}
377 	    }
378 	}
379     }
380 
381   return earliest_block;
382 }
383 
384 /* The following function adds dependencies between jumps and risky
385    insns in given ebb.  */
386 
387 static void
388 add_deps_for_risky_insns (rtx head, rtx tail)
389 {
390   rtx insn, prev;
391   int classification;
392   rtx last_jump = NULL_RTX;
393   rtx next_tail = NEXT_INSN (tail);
394   basic_block last_block = NULL, bb;
395 
396   for (insn = head; insn != next_tail; insn = NEXT_INSN (insn))
397     {
398       add_delay_dependencies (insn);
399       if (control_flow_insn_p (insn))
400 	{
401 	  bb = BLOCK_FOR_INSN (insn);
402 	  bb->aux = last_block;
403 	  last_block = bb;
404 	  /* Ensure blocks stay in the same order.  */
405 	  if (last_jump)
406 	    add_dependence (insn, last_jump, REG_DEP_ANTI);
407 	  last_jump = insn;
408 	}
409       else if (INSN_P (insn) && last_jump != NULL_RTX)
410 	{
411 	  classification = haifa_classify_insn (insn);
412 	  prev = last_jump;
413 
414 	  switch (classification)
415 	    {
416 	    case PFREE_CANDIDATE:
417 	      if (flag_schedule_speculative_load)
418 		{
419 		  bb = earliest_block_with_similiar_load (last_block, insn);
420 		  if (bb)
421 		    {
422 		      bb = (basic_block) bb->aux;
423 		      if (!bb)
424 			break;
425 		      prev = BB_END (bb);
426 		    }
427 		}
428 	      /* Fall through.  */
429 	    case TRAP_RISKY:
430 	    case IRISKY:
431 	    case PRISKY_CANDIDATE:
432 	      /* ??? We could implement better checking PRISKY_CANDIDATEs
433 		 analogous to sched-rgn.c.  */
434 	      /* We can not change the mode of the backward
435 		 dependency because REG_DEP_ANTI has the lowest
436 		 rank.  */
437 	      if (! sched_insns_conditions_mutex_p (insn, prev))
438 		{
439 		  if ((current_sched_info->flags & DO_SPECULATION)
440 		      && (spec_info->mask & BEGIN_CONTROL))
441 		    {
442 		      dep_def _dep, *dep = &_dep;
443 
444 		      init_dep (dep, prev, insn, REG_DEP_ANTI);
445 
446 		      if (current_sched_info->flags & USE_DEPS_LIST)
447 			{
448 			  DEP_STATUS (dep) = set_dep_weak (DEP_ANTI, BEGIN_CONTROL,
449 							   MAX_DEP_WEAK);
450 
451 			}
452 		      sd_add_or_update_dep (dep, false);
453 		    }
454 		  else
455 		    add_dependence (insn, prev, REG_DEP_CONTROL);
456 		}
457 
458 	      break;
459 
460 	    default:
461 	      break;
462 	    }
463 	}
464     }
465   /* Maintain the invariant that bb->aux is clear after use.  */
466   while (last_block)
467     {
468       bb = (basic_block) last_block->aux;
469       last_block->aux = NULL;
470       last_block = bb;
471     }
472 }
473 
474 /* Schedule a single extended basic block, defined by the boundaries
475    HEAD and TAIL.
476 
477    We change our expectations about scheduler behaviour depending on
478    whether MODULO_SCHEDULING is true.  If it is, we expect that the
479    caller has already called set_modulo_params and created delay pairs
480    as appropriate.  If the modulo schedule failed, we return
481    NULL_RTX.  */
482 
483 basic_block
484 schedule_ebb (rtx head, rtx tail, bool modulo_scheduling)
485 {
486   basic_block first_bb, target_bb;
487   struct deps_desc tmp_deps;
488   bool success;
489 
490   /* Blah.  We should fix the rest of the code not to get confused by
491      a note or two.  */
492   while (head != tail)
493     {
494       if (NOTE_P (head) || DEBUG_INSN_P (head))
495 	head = NEXT_INSN (head);
496       else if (NOTE_P (tail) || DEBUG_INSN_P (tail))
497 	tail = PREV_INSN (tail);
498       else if (LABEL_P (head))
499 	head = NEXT_INSN (head);
500       else
501 	break;
502     }
503 
504   first_bb = BLOCK_FOR_INSN (head);
505   last_bb = BLOCK_FOR_INSN (tail);
506 
507   if (no_real_insns_p (head, tail))
508     return BLOCK_FOR_INSN (tail);
509 
510   gcc_assert (INSN_P (head) && INSN_P (tail));
511 
512   if (!bitmap_bit_p (&dont_calc_deps, first_bb->index))
513     {
514       init_deps_global ();
515 
516       /* Compute dependencies.  */
517       init_deps (&tmp_deps, false);
518       sched_analyze (&tmp_deps, head, tail);
519       free_deps (&tmp_deps);
520 
521       add_deps_for_risky_insns (head, tail);
522 
523       if (targetm.sched.dependencies_evaluation_hook)
524         targetm.sched.dependencies_evaluation_hook (head, tail);
525 
526       finish_deps_global ();
527     }
528   else
529     /* Only recovery blocks can have their dependencies already calculated,
530        and they always are single block ebbs.  */
531     gcc_assert (first_bb == last_bb);
532 
533   /* Set priorities.  */
534   current_sched_info->sched_max_insns_priority = 0;
535   rgn_n_insns = set_priorities (head, tail);
536   current_sched_info->sched_max_insns_priority++;
537 
538   current_sched_info->prev_head = PREV_INSN (head);
539   current_sched_info->next_tail = NEXT_INSN (tail);
540 
541   remove_notes (head, tail);
542 
543   unlink_bb_notes (first_bb, last_bb);
544 
545   target_bb = first_bb;
546 
547   /* Make ready list big enough to hold all the instructions from the ebb.  */
548   sched_extend_ready_list (rgn_n_insns);
549   success = schedule_block (&target_bb);
550   gcc_assert (success || modulo_scheduling);
551 
552   /* Free ready list.  */
553   sched_finish_ready_list ();
554 
555   /* We might pack all instructions into fewer blocks,
556      so we may made some of them empty.  Can't assert (b == last_bb).  */
557 
558   /* Sanity check: verify that all region insns were scheduled.  */
559   gcc_assert (modulo_scheduling || sched_rgn_n_insns == rgn_n_insns);
560 
561   /* Free dependencies.  */
562   sched_free_deps (current_sched_info->head, current_sched_info->tail, true);
563 
564   gcc_assert (haifa_recovery_bb_ever_added_p
565 	      || deps_pools_are_empty_p ());
566 
567   if (EDGE_COUNT (last_bb->preds) == 0)
568     /* LAST_BB is unreachable.  */
569     {
570       gcc_assert (first_bb != last_bb
571 		  && EDGE_COUNT (last_bb->succs) == 0);
572       last_bb = last_bb->prev_bb;
573       delete_basic_block (last_bb->next_bb);
574     }
575 
576   return success ? last_bb : NULL;
577 }
578 
579 /* Perform initializations before running schedule_ebbs or a single
580    schedule_ebb.  */
581 void
582 schedule_ebbs_init (void)
583 {
584   /* Setup infos.  */
585   {
586     memcpy (&ebb_common_sched_info, &haifa_common_sched_info,
587 	    sizeof (ebb_common_sched_info));
588 
589     ebb_common_sched_info.fix_recovery_cfg = ebb_fix_recovery_cfg;
590     ebb_common_sched_info.add_block = ebb_add_block;
591     ebb_common_sched_info.sched_pass_id = SCHED_EBB_PASS;
592 
593     common_sched_info = &ebb_common_sched_info;
594     sched_deps_info = &ebb_sched_deps_info;
595     current_sched_info = &ebb_sched_info;
596   }
597 
598   haifa_sched_init ();
599 
600   compute_bb_for_insn ();
601 
602   /* Initialize DONT_CALC_DEPS and ebb-{start, end} markers.  */
603   bitmap_initialize (&dont_calc_deps, 0);
604   bitmap_clear (&dont_calc_deps);
605 }
606 
607 /* Perform cleanups after scheduling using schedules_ebbs or schedule_ebb.  */
608 void
609 schedule_ebbs_finish (void)
610 {
611   bitmap_clear (&dont_calc_deps);
612 
613   /* Reposition the prologue and epilogue notes in case we moved the
614      prologue/epilogue insns.  */
615   if (reload_completed)
616     reposition_prologue_and_epilogue_notes ();
617 
618   haifa_sched_finish ();
619 }
620 
621 /* The main entry point in this file.  */
622 
623 void
624 schedule_ebbs (void)
625 {
626   basic_block bb;
627   int probability_cutoff;
628   rtx tail;
629 
630   /* Taking care of this degenerate case makes the rest of
631      this code simpler.  */
632   if (n_basic_blocks == NUM_FIXED_BLOCKS)
633     return;
634 
635   if (profile_info && flag_branch_probabilities)
636     probability_cutoff = PARAM_VALUE (TRACER_MIN_BRANCH_PROBABILITY_FEEDBACK);
637   else
638     probability_cutoff = PARAM_VALUE (TRACER_MIN_BRANCH_PROBABILITY);
639   probability_cutoff = REG_BR_PROB_BASE / 100 * probability_cutoff;
640 
641   schedule_ebbs_init ();
642 
643   /* Schedule every region in the subroutine.  */
644   FOR_EACH_BB (bb)
645     {
646       rtx head = BB_HEAD (bb);
647 
648       if (bb->flags & BB_DISABLE_SCHEDULE)
649 	continue;
650 
651       for (;;)
652 	{
653 	  edge e;
654 	  tail = BB_END (bb);
655 	  if (bb->next_bb == EXIT_BLOCK_PTR
656 	      || LABEL_P (BB_HEAD (bb->next_bb)))
657 	    break;
658 	  e = find_fallthru_edge (bb->succs);
659 	  if (! e)
660 	    break;
661 	  if (e->probability <= probability_cutoff)
662 	    break;
663 	  if (e->dest->flags & BB_DISABLE_SCHEDULE)
664  	    break;
665 	  bb = bb->next_bb;
666 	}
667 
668       bb = schedule_ebb (head, tail, false);
669     }
670   schedule_ebbs_finish ();
671 }
672 
673 /* INSN has been added to/removed from current ebb.  */
674 static void
675 ebb_add_remove_insn (rtx insn ATTRIBUTE_UNUSED, int remove_p)
676 {
677   if (!remove_p)
678     rgn_n_insns++;
679   else
680     rgn_n_insns--;
681 }
682 
683 /* BB was added to ebb after AFTER.  */
684 static void
685 ebb_add_block (basic_block bb, basic_block after)
686 {
687   /* Recovery blocks are always bounded by BARRIERS,
688      therefore, they always form single block EBB,
689      therefore, we can use rec->index to identify such EBBs.  */
690   if (after == EXIT_BLOCK_PTR)
691     bitmap_set_bit (&dont_calc_deps, bb->index);
692   else if (after == last_bb)
693     last_bb = bb;
694 }
695 
696 /* Return next block in ebb chain.  For parameter meaning please refer to
697    sched-int.h: struct sched_info: advance_target_bb.  */
698 static basic_block
699 advance_target_bb (basic_block bb, rtx insn)
700 {
701   if (insn)
702     {
703       if (BLOCK_FOR_INSN (insn) != bb
704 	  && control_flow_insn_p (insn)
705 	  /* We handle interblock movement of the speculation check
706 	     or over a speculation check in
707 	     haifa-sched.c: move_block_after_check ().  */
708 	  && !IS_SPECULATION_BRANCHY_CHECK_P (insn)
709 	  && !IS_SPECULATION_BRANCHY_CHECK_P (BB_END (bb)))
710 	{
711 	  /* Assert that we don't move jumps across blocks.  */
712 	  gcc_assert (!control_flow_insn_p (BB_END (bb))
713 		      && NOTE_INSN_BASIC_BLOCK_P (BB_HEAD (bb->next_bb)));
714 	  return bb;
715 	}
716       else
717 	return 0;
718     }
719   else
720     /* Return next non empty block.  */
721     {
722       do
723 	{
724 	  gcc_assert (bb != last_bb);
725 
726 	  bb = bb->next_bb;
727 	}
728       while (bb_note (bb) == BB_END (bb));
729 
730       return bb;
731     }
732 }
733 
734 /* Fix internal data after interblock movement of jump instruction.
735    For parameter meaning please refer to
736    sched-int.h: struct sched_info: fix_recovery_cfg.  */
737 static void
738 ebb_fix_recovery_cfg (int bbi ATTRIBUTE_UNUSED, int jump_bbi,
739 		      int jump_bb_nexti)
740 {
741   gcc_assert (last_bb->index != bbi);
742 
743   if (jump_bb_nexti == last_bb->index)
744     last_bb = BASIC_BLOCK (jump_bbi);
745 }
746 
747 #endif /* INSN_SCHEDULING */
748