1 /* Instruction scheduling pass. 2 Copyright (C) 1992-2020 Free Software Foundation, Inc. 3 Contributed by Michael Tiemann (tiemann@cygnus.com) Enhanced by, 4 and currently maintained by, Jim Wilson (wilson@cygnus.com) 5 6 This file is part of GCC. 7 8 GCC is free software; you can redistribute it and/or modify it under 9 the terms of the GNU General Public License as published by the Free 10 Software Foundation; either version 3, or (at your option) any later 11 version. 12 13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14 WARRANTY; without even the implied warranty of MERCHANTABILITY or 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16 for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with GCC; see the file COPYING3. If not see 20 <http://www.gnu.org/licenses/>. */ 21 22 #include "config.h" 23 #include "system.h" 24 #include "coretypes.h" 25 #include "backend.h" 26 #include "target.h" 27 #include "rtl.h" 28 #include "cfghooks.h" 29 #include "df.h" 30 #include "profile.h" 31 #include "insn-attr.h" 32 #include "cfgrtl.h" 33 #include "cfgbuild.h" 34 #include "sched-int.h" 35 36 37 #ifdef INSN_SCHEDULING 38 39 /* The number of insns to be scheduled in total. */ 40 static int rgn_n_insns; 41 42 /* The number of insns scheduled so far. */ 43 static int sched_rgn_n_insns; 44 45 /* Set of blocks, that already have their dependencies calculated. */ 46 static bitmap_head dont_calc_deps; 47 48 /* Last basic block in current ebb. */ 49 static basic_block last_bb; 50 51 /* Implementations of the sched_info functions for region scheduling. */ 52 static void init_ready_list (void); 53 static void begin_schedule_ready (rtx_insn *); 54 static int schedule_more_p (void); 55 static const char *ebb_print_insn (const rtx_insn *, int); 56 static int rank (rtx_insn *, rtx_insn *); 57 static int ebb_contributes_to_priority (rtx_insn *, rtx_insn *); 58 static basic_block earliest_block_with_similiar_load (basic_block, rtx); 59 static void add_deps_for_risky_insns (rtx_insn *, rtx_insn *); 60 static void debug_ebb_dependencies (rtx_insn *, rtx_insn *); 61 62 static void ebb_add_remove_insn (rtx_insn *, int); 63 static void ebb_add_block (basic_block, basic_block); 64 static basic_block advance_target_bb (basic_block, rtx_insn *); 65 static void ebb_fix_recovery_cfg (int, int, int); 66 67 /* Allocate memory and store the state of the frontend. Return the allocated 68 memory. */ 69 static void * 70 save_ebb_state (void) 71 { 72 int *p = XNEW (int); 73 *p = sched_rgn_n_insns; 74 return p; 75 } 76 77 /* Restore the state of the frontend from P_, then free it. */ 78 static void 79 restore_ebb_state (void *p_) 80 { 81 int *p = (int *)p_; 82 sched_rgn_n_insns = *p; 83 free (p_); 84 } 85 86 /* Return nonzero if there are more insns that should be scheduled. */ 87 88 static int 89 schedule_more_p (void) 90 { 91 return sched_rgn_n_insns < rgn_n_insns; 92 } 93 94 /* Print dependency information about ebb between HEAD and TAIL. */ 95 static void 96 debug_ebb_dependencies (rtx_insn *head, rtx_insn *tail) 97 { 98 fprintf (sched_dump, 99 ";; --------------- forward dependences: ------------ \n"); 100 101 fprintf (sched_dump, "\n;; --- EBB Dependences --- from bb%d to bb%d \n", 102 BLOCK_NUM (head), BLOCK_NUM (tail)); 103 104 debug_dependencies (head, tail); 105 } 106 107 /* Add all insns that are initially ready to the ready list READY. Called 108 once before scheduling a set of insns. */ 109 110 static void 111 init_ready_list (void) 112 { 113 int n = 0; 114 rtx_insn *prev_head = current_sched_info->prev_head; 115 rtx_insn *next_tail = current_sched_info->next_tail; 116 rtx_insn *insn; 117 118 sched_rgn_n_insns = 0; 119 120 /* Print debugging information. */ 121 if (sched_verbose >= 5) 122 debug_ebb_dependencies (NEXT_INSN (prev_head), PREV_INSN (next_tail)); 123 124 /* Initialize ready list with all 'ready' insns in target block. 125 Count number of insns in the target block being scheduled. */ 126 for (insn = NEXT_INSN (prev_head); insn != next_tail; insn = NEXT_INSN (insn)) 127 { 128 try_ready (insn); 129 n++; 130 } 131 132 gcc_assert (n == rgn_n_insns); 133 } 134 135 /* INSN is being scheduled after LAST. Update counters. */ 136 static void 137 begin_schedule_ready (rtx_insn *insn ATTRIBUTE_UNUSED) 138 { 139 sched_rgn_n_insns++; 140 } 141 142 /* INSN is being moved to its place in the schedule, after LAST. */ 143 static void 144 begin_move_insn (rtx_insn *insn, rtx_insn *last) 145 { 146 if (BLOCK_FOR_INSN (insn) == last_bb 147 /* INSN is a jump in the last block, ... */ 148 && control_flow_insn_p (insn) 149 /* that is going to be moved over some instructions. */ 150 && last != PREV_INSN (insn)) 151 { 152 edge e; 153 basic_block bb; 154 155 /* An obscure special case, where we do have partially dead 156 instruction scheduled after last control flow instruction. 157 In this case we can create new basic block. It is 158 always exactly one basic block last in the sequence. */ 159 160 e = find_fallthru_edge (last_bb->succs); 161 162 gcc_checking_assert (!e || !(e->flags & EDGE_COMPLEX)); 163 164 gcc_checking_assert (BLOCK_FOR_INSN (insn) == last_bb 165 && !IS_SPECULATION_CHECK_P (insn) 166 && BB_HEAD (last_bb) != insn 167 && BB_END (last_bb) == insn); 168 169 { 170 rtx_insn *x = NEXT_INSN (insn); 171 if (e) 172 gcc_checking_assert (NOTE_P (x) || LABEL_P (x)); 173 else 174 gcc_checking_assert (BARRIER_P (x)); 175 } 176 177 if (e) 178 { 179 bb = split_edge (e); 180 gcc_assert (NOTE_INSN_BASIC_BLOCK_P (BB_END (bb))); 181 } 182 else 183 { 184 /* Create an empty unreachable block after the INSN. */ 185 rtx_insn *next = NEXT_INSN (insn); 186 if (next && BARRIER_P (next)) 187 next = NEXT_INSN (next); 188 bb = create_basic_block (next, NULL_RTX, last_bb); 189 } 190 191 /* split_edge () creates BB before E->DEST. Keep in mind, that 192 this operation extends scheduling region till the end of BB. 193 Hence, we need to shift NEXT_TAIL, so haifa-sched.c won't go out 194 of the scheduling region. */ 195 current_sched_info->next_tail = NEXT_INSN (BB_END (bb)); 196 gcc_assert (current_sched_info->next_tail); 197 198 /* Append new basic block to the end of the ebb. */ 199 sched_init_only_bb (bb, last_bb); 200 gcc_assert (last_bb == bb); 201 } 202 } 203 204 /* Return a string that contains the insn uid and optionally anything else 205 necessary to identify this insn in an output. It's valid to use a 206 static buffer for this. The ALIGNED parameter should cause the string 207 to be formatted so that multiple output lines will line up nicely. */ 208 209 static const char * 210 ebb_print_insn (const rtx_insn *insn, int aligned ATTRIBUTE_UNUSED) 211 { 212 static char tmp[80]; 213 214 /* '+' before insn means it is a new cycle start. */ 215 if (GET_MODE (insn) == TImode) 216 sprintf (tmp, "+ %4d", INSN_UID (insn)); 217 else 218 sprintf (tmp, " %4d", INSN_UID (insn)); 219 220 return tmp; 221 } 222 223 /* Compare priority of two insns. Return a positive number if the second 224 insn is to be preferred for scheduling, and a negative one if the first 225 is to be preferred. Zero if they are equally good. */ 226 227 static int 228 rank (rtx_insn *insn1, rtx_insn *insn2) 229 { 230 basic_block bb1 = BLOCK_FOR_INSN (insn1); 231 basic_block bb2 = BLOCK_FOR_INSN (insn2); 232 233 if (bb1->count > bb2->count) 234 return -1; 235 if (bb1->count < bb2->count) 236 return 1; 237 return 0; 238 } 239 240 /* NEXT is an instruction that depends on INSN (a backward dependence); 241 return nonzero if we should include this dependence in priority 242 calculations. */ 243 244 static int 245 ebb_contributes_to_priority (rtx_insn *next ATTRIBUTE_UNUSED, 246 rtx_insn *insn ATTRIBUTE_UNUSED) 247 { 248 return 1; 249 } 250 251 /* INSN is a JUMP_INSN. Store the set of registers that 252 must be considered as used by this jump in USED. */ 253 254 void 255 ebb_compute_jump_reg_dependencies (rtx insn, regset used) 256 { 257 basic_block b = BLOCK_FOR_INSN (insn); 258 edge e; 259 edge_iterator ei; 260 261 FOR_EACH_EDGE (e, ei, b->succs) 262 if ((e->flags & EDGE_FALLTHRU) == 0) 263 bitmap_ior_into (used, df_get_live_in (e->dest)); 264 } 265 266 /* Used in schedule_insns to initialize current_sched_info for scheduling 267 regions (or single basic blocks). */ 268 269 static struct common_sched_info_def ebb_common_sched_info; 270 271 static struct sched_deps_info_def ebb_sched_deps_info = 272 { 273 ebb_compute_jump_reg_dependencies, 274 NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, 275 NULL, 276 1, 0, 0 277 }; 278 279 static struct haifa_sched_info ebb_sched_info = 280 { 281 init_ready_list, 282 NULL, 283 schedule_more_p, 284 NULL, 285 rank, 286 ebb_print_insn, 287 ebb_contributes_to_priority, 288 NULL, /* insn_finishes_block_p */ 289 290 NULL, NULL, 291 NULL, NULL, 292 1, 0, 293 294 ebb_add_remove_insn, 295 begin_schedule_ready, 296 begin_move_insn, 297 advance_target_bb, 298 299 save_ebb_state, 300 restore_ebb_state, 301 302 SCHED_EBB 303 /* We can create new blocks in begin_schedule_ready (). */ 304 | NEW_BBS 305 }; 306 307 /* Returns the earliest block in EBB currently being processed where a 308 "similar load" 'insn2' is found, and hence LOAD_INSN can move 309 speculatively into the found block. All the following must hold: 310 311 (1) both loads have 1 base register (PFREE_CANDIDATEs). 312 (2) load_insn and load2 have a def-use dependence upon 313 the same insn 'insn1'. 314 315 From all these we can conclude that the two loads access memory 316 addresses that differ at most by a constant, and hence if moving 317 load_insn would cause an exception, it would have been caused by 318 load2 anyhow. 319 320 The function uses list (given by LAST_BLOCK) of already processed 321 blocks in EBB. The list is formed in `add_deps_for_risky_insns'. */ 322 323 static basic_block 324 earliest_block_with_similiar_load (basic_block last_block, rtx load_insn) 325 { 326 sd_iterator_def back_sd_it; 327 dep_t back_dep; 328 basic_block bb, earliest_block = NULL; 329 330 FOR_EACH_DEP (load_insn, SD_LIST_BACK, back_sd_it, back_dep) 331 { 332 rtx_insn *insn1 = DEP_PRO (back_dep); 333 334 if (DEP_TYPE (back_dep) == REG_DEP_TRUE) 335 /* Found a DEF-USE dependence (insn1, load_insn). */ 336 { 337 sd_iterator_def fore_sd_it; 338 dep_t fore_dep; 339 340 FOR_EACH_DEP (insn1, SD_LIST_FORW, fore_sd_it, fore_dep) 341 { 342 rtx_insn *insn2 = DEP_CON (fore_dep); 343 basic_block insn2_block = BLOCK_FOR_INSN (insn2); 344 345 if (DEP_TYPE (fore_dep) == REG_DEP_TRUE) 346 { 347 if (earliest_block != NULL 348 && earliest_block->index < insn2_block->index) 349 continue; 350 351 /* Found a DEF-USE dependence (insn1, insn2). */ 352 if (haifa_classify_insn (insn2) != PFREE_CANDIDATE) 353 /* insn2 not guaranteed to be a 1 base reg load. */ 354 continue; 355 356 for (bb = last_block; bb; bb = (basic_block) bb->aux) 357 if (insn2_block == bb) 358 break; 359 360 if (!bb) 361 /* insn2 is the similar load. */ 362 earliest_block = insn2_block; 363 } 364 } 365 } 366 } 367 368 return earliest_block; 369 } 370 371 /* The following function adds dependencies between jumps and risky 372 insns in given ebb. */ 373 374 static void 375 add_deps_for_risky_insns (rtx_insn *head, rtx_insn *tail) 376 { 377 rtx_insn *insn, *prev; 378 int classification; 379 rtx_insn *last_jump = NULL; 380 rtx_insn *next_tail = NEXT_INSN (tail); 381 basic_block last_block = NULL, bb; 382 383 for (insn = head; insn != next_tail; insn = NEXT_INSN (insn)) 384 { 385 add_delay_dependencies (insn); 386 if (control_flow_insn_p (insn)) 387 { 388 bb = BLOCK_FOR_INSN (insn); 389 bb->aux = last_block; 390 last_block = bb; 391 /* Ensure blocks stay in the same order. */ 392 if (last_jump) 393 add_dependence (insn, last_jump, REG_DEP_ANTI); 394 last_jump = insn; 395 } 396 else if (INSN_P (insn) && last_jump != NULL_RTX) 397 { 398 classification = haifa_classify_insn (insn); 399 prev = last_jump; 400 401 switch (classification) 402 { 403 case PFREE_CANDIDATE: 404 if (flag_schedule_speculative_load) 405 { 406 bb = earliest_block_with_similiar_load (last_block, insn); 407 if (bb) 408 { 409 bb = (basic_block) bb->aux; 410 if (!bb) 411 break; 412 prev = BB_END (bb); 413 } 414 } 415 /* Fall through. */ 416 case TRAP_RISKY: 417 case IRISKY: 418 case PRISKY_CANDIDATE: 419 /* ??? We could implement better checking PRISKY_CANDIDATEs 420 analogous to sched-rgn.c. */ 421 /* We cannot change the mode of the backward 422 dependency because REG_DEP_ANTI has the lowest 423 rank. */ 424 if (! sched_insns_conditions_mutex_p (insn, prev)) 425 { 426 if ((current_sched_info->flags & DO_SPECULATION) 427 && (spec_info->mask & BEGIN_CONTROL)) 428 { 429 dep_def _dep, *dep = &_dep; 430 431 init_dep (dep, prev, insn, REG_DEP_ANTI); 432 433 if (current_sched_info->flags & USE_DEPS_LIST) 434 { 435 DEP_STATUS (dep) = set_dep_weak (DEP_ANTI, BEGIN_CONTROL, 436 MAX_DEP_WEAK); 437 438 } 439 sd_add_or_update_dep (dep, false); 440 } 441 else 442 add_dependence (insn, prev, REG_DEP_CONTROL); 443 } 444 445 break; 446 447 default: 448 break; 449 } 450 } 451 } 452 /* Maintain the invariant that bb->aux is clear after use. */ 453 while (last_block) 454 { 455 bb = (basic_block) last_block->aux; 456 last_block->aux = NULL; 457 last_block = bb; 458 } 459 } 460 461 /* Schedule a single extended basic block, defined by the boundaries 462 HEAD and TAIL. 463 464 We change our expectations about scheduler behavior depending on 465 whether MODULO_SCHEDULING is true. If it is, we expect that the 466 caller has already called set_modulo_params and created delay pairs 467 as appropriate. If the modulo schedule failed, we return 468 NULL_RTX. */ 469 470 basic_block 471 schedule_ebb (rtx_insn *head, rtx_insn *tail, bool modulo_scheduling) 472 { 473 basic_block first_bb, target_bb; 474 class deps_desc tmp_deps; 475 bool success; 476 477 /* Blah. We should fix the rest of the code not to get confused by 478 a note or two. */ 479 while (head != tail) 480 { 481 if (NOTE_P (head) || DEBUG_INSN_P (head)) 482 head = NEXT_INSN (head); 483 else if (NOTE_P (tail) || DEBUG_INSN_P (tail)) 484 tail = PREV_INSN (tail); 485 else if (LABEL_P (head)) 486 head = NEXT_INSN (head); 487 else 488 break; 489 } 490 491 first_bb = BLOCK_FOR_INSN (head); 492 last_bb = BLOCK_FOR_INSN (tail); 493 494 if (no_real_insns_p (head, tail)) 495 return BLOCK_FOR_INSN (tail); 496 497 gcc_assert (INSN_P (head) && INSN_P (tail)); 498 499 if (!bitmap_bit_p (&dont_calc_deps, first_bb->index)) 500 { 501 init_deps_global (); 502 503 /* Compute dependencies. */ 504 init_deps (&tmp_deps, false); 505 sched_analyze (&tmp_deps, head, tail); 506 free_deps (&tmp_deps); 507 508 add_deps_for_risky_insns (head, tail); 509 510 if (targetm.sched.dependencies_evaluation_hook) 511 targetm.sched.dependencies_evaluation_hook (head, tail); 512 513 finish_deps_global (); 514 } 515 else 516 /* Only recovery blocks can have their dependencies already calculated, 517 and they always are single block ebbs. */ 518 gcc_assert (first_bb == last_bb); 519 520 /* Set priorities. */ 521 current_sched_info->sched_max_insns_priority = 0; 522 rgn_n_insns = set_priorities (head, tail); 523 current_sched_info->sched_max_insns_priority++; 524 525 current_sched_info->prev_head = PREV_INSN (head); 526 current_sched_info->next_tail = NEXT_INSN (tail); 527 528 remove_notes (head, tail); 529 530 unlink_bb_notes (first_bb, last_bb); 531 532 target_bb = first_bb; 533 534 /* Make ready list big enough to hold all the instructions from the ebb. */ 535 sched_extend_ready_list (rgn_n_insns); 536 success = schedule_block (&target_bb, NULL); 537 gcc_assert (success || modulo_scheduling); 538 539 /* Free ready list. */ 540 sched_finish_ready_list (); 541 542 /* We might pack all instructions into fewer blocks, 543 so we may made some of them empty. Can't assert (b == last_bb). */ 544 545 /* Sanity check: verify that all region insns were scheduled. */ 546 gcc_assert (modulo_scheduling || sched_rgn_n_insns == rgn_n_insns); 547 548 /* Free dependencies. */ 549 sched_free_deps (current_sched_info->head, current_sched_info->tail, true); 550 551 gcc_assert (haifa_recovery_bb_ever_added_p 552 || deps_pools_are_empty_p ()); 553 554 if (EDGE_COUNT (last_bb->preds) == 0) 555 /* LAST_BB is unreachable. */ 556 { 557 gcc_assert (first_bb != last_bb 558 && EDGE_COUNT (last_bb->succs) == 0); 559 last_bb = last_bb->prev_bb; 560 delete_basic_block (last_bb->next_bb); 561 } 562 563 return success ? last_bb : NULL; 564 } 565 566 /* Perform initializations before running schedule_ebbs or a single 567 schedule_ebb. */ 568 void 569 schedule_ebbs_init (void) 570 { 571 /* Setup infos. */ 572 { 573 memcpy (&ebb_common_sched_info, &haifa_common_sched_info, 574 sizeof (ebb_common_sched_info)); 575 576 ebb_common_sched_info.fix_recovery_cfg = ebb_fix_recovery_cfg; 577 ebb_common_sched_info.add_block = ebb_add_block; 578 ebb_common_sched_info.sched_pass_id = SCHED_EBB_PASS; 579 580 common_sched_info = &ebb_common_sched_info; 581 sched_deps_info = &ebb_sched_deps_info; 582 current_sched_info = &ebb_sched_info; 583 } 584 585 haifa_sched_init (); 586 587 compute_bb_for_insn (); 588 589 /* Initialize DONT_CALC_DEPS and ebb-{start, end} markers. */ 590 bitmap_initialize (&dont_calc_deps, &bitmap_default_obstack); 591 } 592 593 /* Perform cleanups after scheduling using schedules_ebbs or schedule_ebb. */ 594 void 595 schedule_ebbs_finish (void) 596 { 597 bitmap_release (&dont_calc_deps); 598 599 /* Reposition the prologue and epilogue notes in case we moved the 600 prologue/epilogue insns. */ 601 if (reload_completed) 602 reposition_prologue_and_epilogue_notes (); 603 604 haifa_sched_finish (); 605 } 606 607 /* The main entry point in this file. */ 608 609 void 610 schedule_ebbs (void) 611 { 612 basic_block bb; 613 int probability_cutoff; 614 rtx_insn *tail; 615 616 /* Taking care of this degenerate case makes the rest of 617 this code simpler. */ 618 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS) 619 return; 620 621 if (profile_info && profile_status_for_fn (cfun) == PROFILE_READ) 622 probability_cutoff = param_tracer_min_branch_probability_feedback; 623 else 624 probability_cutoff = param_tracer_min_branch_probability; 625 probability_cutoff = REG_BR_PROB_BASE / 100 * probability_cutoff; 626 627 schedule_ebbs_init (); 628 629 /* Schedule every region in the subroutine. */ 630 FOR_EACH_BB_FN (bb, cfun) 631 { 632 rtx_insn *head = BB_HEAD (bb); 633 634 if (bb->flags & BB_DISABLE_SCHEDULE) 635 continue; 636 637 for (;;) 638 { 639 edge e; 640 tail = BB_END (bb); 641 if (bb->next_bb == EXIT_BLOCK_PTR_FOR_FN (cfun) 642 || LABEL_P (BB_HEAD (bb->next_bb))) 643 break; 644 e = find_fallthru_edge (bb->succs); 645 if (! e) 646 break; 647 if (e->probability.initialized_p () 648 && e->probability.to_reg_br_prob_base () <= probability_cutoff) 649 break; 650 if (e->dest->flags & BB_DISABLE_SCHEDULE) 651 break; 652 bb = bb->next_bb; 653 } 654 655 bb = schedule_ebb (head, tail, false); 656 } 657 schedule_ebbs_finish (); 658 } 659 660 /* INSN has been added to/removed from current ebb. */ 661 static void 662 ebb_add_remove_insn (rtx_insn *insn ATTRIBUTE_UNUSED, int remove_p) 663 { 664 if (!remove_p) 665 rgn_n_insns++; 666 else 667 rgn_n_insns--; 668 } 669 670 /* BB was added to ebb after AFTER. */ 671 static void 672 ebb_add_block (basic_block bb, basic_block after) 673 { 674 /* Recovery blocks are always bounded by BARRIERS, 675 therefore, they always form single block EBB, 676 therefore, we can use rec->index to identify such EBBs. */ 677 if (after == EXIT_BLOCK_PTR_FOR_FN (cfun)) 678 bitmap_set_bit (&dont_calc_deps, bb->index); 679 else if (after == last_bb) 680 last_bb = bb; 681 } 682 683 /* Return next block in ebb chain. For parameter meaning please refer to 684 sched-int.h: struct sched_info: advance_target_bb. */ 685 static basic_block 686 advance_target_bb (basic_block bb, rtx_insn *insn) 687 { 688 if (insn) 689 { 690 if (BLOCK_FOR_INSN (insn) != bb 691 && control_flow_insn_p (insn) 692 /* We handle interblock movement of the speculation check 693 or over a speculation check in 694 haifa-sched.c: move_block_after_check (). */ 695 && !IS_SPECULATION_BRANCHY_CHECK_P (insn) 696 && !IS_SPECULATION_BRANCHY_CHECK_P (BB_END (bb))) 697 { 698 /* Assert that we don't move jumps across blocks. */ 699 gcc_assert (!control_flow_insn_p (BB_END (bb)) 700 && NOTE_INSN_BASIC_BLOCK_P (BB_HEAD (bb->next_bb))); 701 return bb; 702 } 703 else 704 return 0; 705 } 706 else 707 /* Return next non empty block. */ 708 { 709 do 710 { 711 gcc_assert (bb != last_bb); 712 713 bb = bb->next_bb; 714 } 715 while (bb_note (bb) == BB_END (bb)); 716 717 return bb; 718 } 719 } 720 721 /* Fix internal data after interblock movement of jump instruction. 722 For parameter meaning please refer to 723 sched-int.h: struct sched_info: fix_recovery_cfg. */ 724 static void 725 ebb_fix_recovery_cfg (int bbi ATTRIBUTE_UNUSED, int jump_bbi, 726 int jump_bb_nexti) 727 { 728 gcc_assert (last_bb->index != bbi); 729 730 if (jump_bb_nexti == last_bb->index) 731 last_bb = BASIC_BLOCK_FOR_FN (cfun, jump_bbi); 732 } 733 734 #endif /* INSN_SCHEDULING */ 735