1/* Control flow graph manipulation code for GNU compiler. 2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 3 1999, 2000, 2001, 2002, 2003, 2004, 2005 4 Free Software Foundation, Inc. 5 6This file is part of GCC. 7 8GCC is free software; you can redistribute it and/or modify it under 9the terms of the GNU General Public License as published by the Free 10Software Foundation; either version 2, or (at your option) any later 11version. 12 13GCC is distributed in the hope that it will be useful, but WITHOUT ANY 14WARRANTY; without even the implied warranty of MERCHANTABILITY or 15FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 16for more details. 17 18You should have received a copy of the GNU General Public License 19along with GCC; see the file COPYING. If not, write to the Free 20Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 2102110-1301, USA. */ 22 23/* This file contains low level functions to manipulate the CFG and 24 analyze it. All other modules should not transform the data structure 25 directly and use abstraction instead. The file is supposed to be 26 ordered bottom-up and should not contain any code dependent on a 27 particular intermediate language (RTL or trees). 28 29 Available functionality: 30 - Initialization/deallocation 31 init_flow, clear_edges 32 - Low level basic block manipulation 33 alloc_block, expunge_block 34 - Edge manipulation 35 make_edge, make_single_succ_edge, cached_make_edge, remove_edge 36 - Low level edge redirection (without updating instruction chain) 37 redirect_edge_succ, redirect_edge_succ_nodup, redirect_edge_pred 38 - Dumping and debugging 39 dump_flow_info, debug_flow_info, dump_edge_info 40 - Allocation of AUX fields for basic blocks 41 alloc_aux_for_blocks, free_aux_for_blocks, alloc_aux_for_block 42 - clear_bb_flags 43 - Consistency checking 44 verify_flow_info 45 - Dumping and debugging 46 print_rtl_with_bb, dump_bb, debug_bb, debug_bb_n 47 */ 48 49#include "config.h" 50#include "system.h" 51#include "coretypes.h" 52#include "tm.h" 53#include "tree.h" 54#include "rtl.h" 55#include "hard-reg-set.h" 56#include "regs.h" 57#include "flags.h" 58#include "output.h" 59#include "function.h" 60#include "except.h" 61#include "toplev.h" 62#include "tm_p.h" 63#include "obstack.h" 64#include "timevar.h" 65#include "ggc.h" 66#include "hashtab.h" 67#include "alloc-pool.h" 68 69/* The obstack on which the flow graph components are allocated. */ 70 71struct bitmap_obstack reg_obstack; 72 73void debug_flow_info (void); 74static void free_edge (edge); 75 76#define RDIV(X,Y) (((X) + (Y) / 2) / (Y)) 77 78/* Called once at initialization time. */ 79 80void 81init_flow (void) 82{ 83 if (!cfun->cfg) 84 cfun->cfg = ggc_alloc_cleared (sizeof (struct control_flow_graph)); 85 n_edges = 0; 86 ENTRY_BLOCK_PTR = ggc_alloc_cleared (sizeof (struct basic_block_def)); 87 ENTRY_BLOCK_PTR->index = ENTRY_BLOCK; 88 EXIT_BLOCK_PTR = ggc_alloc_cleared (sizeof (struct basic_block_def)); 89 EXIT_BLOCK_PTR->index = EXIT_BLOCK; 90 ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR; 91 EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR; 92} 93 94/* Helper function for remove_edge and clear_edges. Frees edge structure 95 without actually unlinking it from the pred/succ lists. */ 96 97static void 98free_edge (edge e ATTRIBUTE_UNUSED) 99{ 100 n_edges--; 101 ggc_free (e); 102} 103 104/* Free the memory associated with the edge structures. */ 105 106void 107clear_edges (void) 108{ 109 basic_block bb; 110 edge e; 111 edge_iterator ei; 112 113 FOR_EACH_BB (bb) 114 { 115 FOR_EACH_EDGE (e, ei, bb->succs) 116 free_edge (e); 117 VEC_truncate (edge, bb->succs, 0); 118 VEC_truncate (edge, bb->preds, 0); 119 } 120 121 FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs) 122 free_edge (e); 123 VEC_truncate (edge, EXIT_BLOCK_PTR->preds, 0); 124 VEC_truncate (edge, ENTRY_BLOCK_PTR->succs, 0); 125 126 gcc_assert (!n_edges); 127} 128 129/* Allocate memory for basic_block. */ 130 131basic_block 132alloc_block (void) 133{ 134 basic_block bb; 135 bb = ggc_alloc_cleared (sizeof (*bb)); 136 return bb; 137} 138 139/* Link block B to chain after AFTER. */ 140void 141link_block (basic_block b, basic_block after) 142{ 143 b->next_bb = after->next_bb; 144 b->prev_bb = after; 145 after->next_bb = b; 146 b->next_bb->prev_bb = b; 147} 148 149/* Unlink block B from chain. */ 150void 151unlink_block (basic_block b) 152{ 153 b->next_bb->prev_bb = b->prev_bb; 154 b->prev_bb->next_bb = b->next_bb; 155 b->prev_bb = NULL; 156 b->next_bb = NULL; 157} 158 159/* Sequentially order blocks and compact the arrays. */ 160void 161compact_blocks (void) 162{ 163 int i; 164 basic_block bb; 165 166 i = 0; 167 FOR_EACH_BB (bb) 168 { 169 BASIC_BLOCK (i) = bb; 170 bb->index = i; 171 i++; 172 } 173 174 gcc_assert (i == n_basic_blocks); 175 176 for (; i < last_basic_block; i++) 177 BASIC_BLOCK (i) = NULL; 178 179 last_basic_block = n_basic_blocks; 180} 181 182/* Remove block B from the basic block array. */ 183 184void 185expunge_block (basic_block b) 186{ 187 unlink_block (b); 188 BASIC_BLOCK (b->index) = NULL; 189 n_basic_blocks--; 190 /* We should be able to ggc_free here, but we are not. 191 The dead SSA_NAMES are left pointing to dead statements that are pointing 192 to dead basic blocks making garbage collector to die. 193 We should be able to release all dead SSA_NAMES and at the same time we should 194 clear out BB pointer of dead statements consistently. */ 195} 196 197/* Connect E to E->src. */ 198 199static inline void 200connect_src (edge e) 201{ 202 VEC_safe_push (edge, gc, e->src->succs, e); 203} 204 205/* Connect E to E->dest. */ 206 207static inline void 208connect_dest (edge e) 209{ 210 basic_block dest = e->dest; 211 VEC_safe_push (edge, gc, dest->preds, e); 212 e->dest_idx = EDGE_COUNT (dest->preds) - 1; 213} 214 215/* Disconnect edge E from E->src. */ 216 217static inline void 218disconnect_src (edge e) 219{ 220 basic_block src = e->src; 221 edge_iterator ei; 222 edge tmp; 223 224 for (ei = ei_start (src->succs); (tmp = ei_safe_edge (ei)); ) 225 { 226 if (tmp == e) 227 { 228 VEC_unordered_remove (edge, src->succs, ei.index); 229 return; 230 } 231 else 232 ei_next (&ei); 233 } 234 235 gcc_unreachable (); 236} 237 238/* Disconnect edge E from E->dest. */ 239 240static inline void 241disconnect_dest (edge e) 242{ 243 basic_block dest = e->dest; 244 unsigned int dest_idx = e->dest_idx; 245 246 VEC_unordered_remove (edge, dest->preds, dest_idx); 247 248 /* If we removed an edge in the middle of the edge vector, we need 249 to update dest_idx of the edge that moved into the "hole". */ 250 if (dest_idx < EDGE_COUNT (dest->preds)) 251 EDGE_PRED (dest, dest_idx)->dest_idx = dest_idx; 252} 253 254/* Create an edge connecting SRC and DEST with flags FLAGS. Return newly 255 created edge. Use this only if you are sure that this edge can't 256 possibly already exist. */ 257 258edge 259unchecked_make_edge (basic_block src, basic_block dst, int flags) 260{ 261 edge e; 262 e = ggc_alloc_cleared (sizeof (*e)); 263 n_edges++; 264 265 e->src = src; 266 e->dest = dst; 267 e->flags = flags; 268 269 connect_src (e); 270 connect_dest (e); 271 272 execute_on_growing_pred (e); 273 274 return e; 275} 276 277/* Create an edge connecting SRC and DST with FLAGS optionally using 278 edge cache CACHE. Return the new edge, NULL if already exist. */ 279 280edge 281cached_make_edge (sbitmap edge_cache, basic_block src, basic_block dst, int flags) 282{ 283 if (edge_cache == NULL 284 || src == ENTRY_BLOCK_PTR 285 || dst == EXIT_BLOCK_PTR) 286 return make_edge (src, dst, flags); 287 288 /* Does the requested edge already exist? */ 289 if (! TEST_BIT (edge_cache, dst->index)) 290 { 291 /* The edge does not exist. Create one and update the 292 cache. */ 293 SET_BIT (edge_cache, dst->index); 294 return unchecked_make_edge (src, dst, flags); 295 } 296 297 /* At this point, we know that the requested edge exists. Adjust 298 flags if necessary. */ 299 if (flags) 300 { 301 edge e = find_edge (src, dst); 302 e->flags |= flags; 303 } 304 305 return NULL; 306} 307 308/* Create an edge connecting SRC and DEST with flags FLAGS. Return newly 309 created edge or NULL if already exist. */ 310 311edge 312make_edge (basic_block src, basic_block dest, int flags) 313{ 314 edge e = find_edge (src, dest); 315 316 /* Make sure we don't add duplicate edges. */ 317 if (e) 318 { 319 e->flags |= flags; 320 return NULL; 321 } 322 323 return unchecked_make_edge (src, dest, flags); 324} 325 326/* Create an edge connecting SRC to DEST and set probability by knowing 327 that it is the single edge leaving SRC. */ 328 329edge 330make_single_succ_edge (basic_block src, basic_block dest, int flags) 331{ 332 edge e = make_edge (src, dest, flags); 333 334 e->probability = REG_BR_PROB_BASE; 335 e->count = src->count; 336 return e; 337} 338 339/* This function will remove an edge from the flow graph. */ 340 341void 342remove_edge (edge e) 343{ 344 remove_predictions_associated_with_edge (e); 345 execute_on_shrinking_pred (e); 346 347 disconnect_src (e); 348 disconnect_dest (e); 349 350 free_edge (e); 351} 352 353/* Redirect an edge's successor from one block to another. */ 354 355void 356redirect_edge_succ (edge e, basic_block new_succ) 357{ 358 execute_on_shrinking_pred (e); 359 360 disconnect_dest (e); 361 362 e->dest = new_succ; 363 364 /* Reconnect the edge to the new successor block. */ 365 connect_dest (e); 366 367 execute_on_growing_pred (e); 368} 369 370/* Like previous but avoid possible duplicate edge. */ 371 372edge 373redirect_edge_succ_nodup (edge e, basic_block new_succ) 374{ 375 edge s; 376 377 s = find_edge (e->src, new_succ); 378 if (s && s != e) 379 { 380 s->flags |= e->flags; 381 s->probability += e->probability; 382 if (s->probability > REG_BR_PROB_BASE) 383 s->probability = REG_BR_PROB_BASE; 384 s->count += e->count; 385 remove_edge (e); 386 e = s; 387 } 388 else 389 redirect_edge_succ (e, new_succ); 390 391 return e; 392} 393 394/* Redirect an edge's predecessor from one block to another. */ 395 396void 397redirect_edge_pred (edge e, basic_block new_pred) 398{ 399 disconnect_src (e); 400 401 e->src = new_pred; 402 403 /* Reconnect the edge to the new predecessor block. */ 404 connect_src (e); 405} 406 407/* Clear all basic block flags, with the exception of partitioning. */ 408void 409clear_bb_flags (void) 410{ 411 basic_block bb; 412 413 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) 414 bb->flags = (BB_PARTITION (bb) | (bb->flags & BB_DISABLE_SCHEDULE) 415 | (bb->flags & BB_RTL)); 416} 417 418/* Check the consistency of profile information. We can't do that 419 in verify_flow_info, as the counts may get invalid for incompletely 420 solved graphs, later eliminating of conditionals or roundoff errors. 421 It is still practical to have them reported for debugging of simple 422 testcases. */ 423void 424check_bb_profile (basic_block bb, FILE * file) 425{ 426 edge e; 427 int sum = 0; 428 gcov_type lsum; 429 edge_iterator ei; 430 431 if (profile_status == PROFILE_ABSENT) 432 return; 433 434 if (bb != EXIT_BLOCK_PTR) 435 { 436 FOR_EACH_EDGE (e, ei, bb->succs) 437 sum += e->probability; 438 if (EDGE_COUNT (bb->succs) && abs (sum - REG_BR_PROB_BASE) > 100) 439 fprintf (file, "Invalid sum of outgoing probabilities %.1f%%\n", 440 sum * 100.0 / REG_BR_PROB_BASE); 441 lsum = 0; 442 FOR_EACH_EDGE (e, ei, bb->succs) 443 lsum += e->count; 444 if (EDGE_COUNT (bb->succs) 445 && (lsum - bb->count > 100 || lsum - bb->count < -100)) 446 fprintf (file, "Invalid sum of outgoing counts %i, should be %i\n", 447 (int) lsum, (int) bb->count); 448 } 449 if (bb != ENTRY_BLOCK_PTR) 450 { 451 sum = 0; 452 FOR_EACH_EDGE (e, ei, bb->preds) 453 sum += EDGE_FREQUENCY (e); 454 if (abs (sum - bb->frequency) > 100) 455 fprintf (file, 456 "Invalid sum of incoming frequencies %i, should be %i\n", 457 sum, bb->frequency); 458 lsum = 0; 459 FOR_EACH_EDGE (e, ei, bb->preds) 460 lsum += e->count; 461 if (lsum - bb->count > 100 || lsum - bb->count < -100) 462 fprintf (file, "Invalid sum of incoming counts %i, should be %i\n", 463 (int) lsum, (int) bb->count); 464 } 465} 466 467void 468dump_flow_info (FILE *file) 469{ 470 basic_block bb; 471 472 /* There are no pseudo registers after reload. Don't dump them. */ 473 if (reg_n_info && !reload_completed) 474 { 475 unsigned int i, max = max_reg_num (); 476 fprintf (file, "%d registers.\n", max); 477 for (i = FIRST_PSEUDO_REGISTER; i < max; i++) 478 if (REG_N_REFS (i)) 479 { 480 enum reg_class class, altclass; 481 482 fprintf (file, "\nRegister %d used %d times across %d insns", 483 i, REG_N_REFS (i), REG_LIVE_LENGTH (i)); 484 if (REG_BASIC_BLOCK (i) >= 0) 485 fprintf (file, " in block %d", REG_BASIC_BLOCK (i)); 486 if (REG_N_SETS (i)) 487 fprintf (file, "; set %d time%s", REG_N_SETS (i), 488 (REG_N_SETS (i) == 1) ? "" : "s"); 489 if (regno_reg_rtx[i] != NULL && REG_USERVAR_P (regno_reg_rtx[i])) 490 fprintf (file, "; user var"); 491 if (REG_N_DEATHS (i) != 1) 492 fprintf (file, "; dies in %d places", REG_N_DEATHS (i)); 493 if (REG_N_CALLS_CROSSED (i) == 1) 494 fprintf (file, "; crosses 1 call"); 495 else if (REG_N_CALLS_CROSSED (i)) 496 fprintf (file, "; crosses %d calls", REG_N_CALLS_CROSSED (i)); 497 if (regno_reg_rtx[i] != NULL 498 && PSEUDO_REGNO_BYTES (i) != UNITS_PER_WORD) 499 fprintf (file, "; %d bytes", PSEUDO_REGNO_BYTES (i)); 500 501 class = reg_preferred_class (i); 502 altclass = reg_alternate_class (i); 503 if (class != GENERAL_REGS || altclass != ALL_REGS) 504 { 505 if (altclass == ALL_REGS || class == ALL_REGS) 506 fprintf (file, "; pref %s", reg_class_names[(int) class]); 507 else if (altclass == NO_REGS) 508 fprintf (file, "; %s or none", reg_class_names[(int) class]); 509 else 510 fprintf (file, "; pref %s, else %s", 511 reg_class_names[(int) class], 512 reg_class_names[(int) altclass]); 513 } 514 515 if (regno_reg_rtx[i] != NULL && REG_POINTER (regno_reg_rtx[i])) 516 fprintf (file, "; pointer"); 517 fprintf (file, ".\n"); 518 } 519 } 520 521 fprintf (file, "\n%d basic blocks, %d edges.\n", n_basic_blocks, n_edges); 522 FOR_EACH_BB (bb) 523 { 524 edge e; 525 edge_iterator ei; 526 527 fprintf (file, "\nBasic block %d ", bb->index); 528 fprintf (file, "prev %d, next %d, ", 529 bb->prev_bb->index, bb->next_bb->index); 530 fprintf (file, "loop_depth %d, count ", bb->loop_depth); 531 fprintf (file, HOST_WIDEST_INT_PRINT_DEC, bb->count); 532 fprintf (file, ", freq %i", bb->frequency); 533 if (maybe_hot_bb_p (bb)) 534 fprintf (file, ", maybe hot"); 535 if (probably_never_executed_bb_p (bb)) 536 fprintf (file, ", probably never executed"); 537 fprintf (file, ".\n"); 538 539 fprintf (file, "Predecessors: "); 540 FOR_EACH_EDGE (e, ei, bb->preds) 541 dump_edge_info (file, e, 0); 542 543 fprintf (file, "\nSuccessors: "); 544 FOR_EACH_EDGE (e, ei, bb->succs) 545 dump_edge_info (file, e, 1); 546 547 if (bb->flags & BB_RTL) 548 { 549 if (bb->il.rtl->global_live_at_start) 550 { 551 fprintf (file, "\nRegisters live at start:"); 552 dump_regset (bb->il.rtl->global_live_at_start, file); 553 } 554 555 if (bb->il.rtl->global_live_at_end) 556 { 557 fprintf (file, "\nRegisters live at end:"); 558 dump_regset (bb->il.rtl->global_live_at_end, file); 559 } 560 } 561 562 putc ('\n', file); 563 check_bb_profile (bb, file); 564 } 565 566 putc ('\n', file); 567} 568 569void 570debug_flow_info (void) 571{ 572 dump_flow_info (stderr); 573} 574 575void 576dump_edge_info (FILE *file, edge e, int do_succ) 577{ 578 basic_block side = (do_succ ? e->dest : e->src); 579 580 if (side == ENTRY_BLOCK_PTR) 581 fputs (" ENTRY", file); 582 else if (side == EXIT_BLOCK_PTR) 583 fputs (" EXIT", file); 584 else 585 fprintf (file, " %d", side->index); 586 587 if (e->probability) 588 fprintf (file, " [%.1f%%] ", e->probability * 100.0 / REG_BR_PROB_BASE); 589 590 if (e->count) 591 { 592 fprintf (file, " count:"); 593 fprintf (file, HOST_WIDEST_INT_PRINT_DEC, e->count); 594 } 595 596 if (e->flags) 597 { 598 static const char * const bitnames[] = { 599 "fallthru", "ab", "abcall", "eh", "fake", "dfs_back", 600 "can_fallthru", "irreducible", "sibcall", "loop_exit", 601 "true", "false", "exec" 602 }; 603 int comma = 0; 604 int i, flags = e->flags; 605 606 fputs (" (", file); 607 for (i = 0; flags; i++) 608 if (flags & (1 << i)) 609 { 610 flags &= ~(1 << i); 611 612 if (comma) 613 fputc (',', file); 614 if (i < (int) ARRAY_SIZE (bitnames)) 615 fputs (bitnames[i], file); 616 else 617 fprintf (file, "%d", i); 618 comma = 1; 619 } 620 621 fputc (')', file); 622 } 623} 624 625/* Simple routines to easily allocate AUX fields of basic blocks. */ 626 627static struct obstack block_aux_obstack; 628static void *first_block_aux_obj = 0; 629static struct obstack edge_aux_obstack; 630static void *first_edge_aux_obj = 0; 631 632/* Allocate a memory block of SIZE as BB->aux. The obstack must 633 be first initialized by alloc_aux_for_blocks. */ 634 635inline void 636alloc_aux_for_block (basic_block bb, int size) 637{ 638 /* Verify that aux field is clear. */ 639 gcc_assert (!bb->aux && first_block_aux_obj); 640 bb->aux = obstack_alloc (&block_aux_obstack, size); 641 memset (bb->aux, 0, size); 642} 643 644/* Initialize the block_aux_obstack and if SIZE is nonzero, call 645 alloc_aux_for_block for each basic block. */ 646 647void 648alloc_aux_for_blocks (int size) 649{ 650 static int initialized; 651 652 if (!initialized) 653 { 654 gcc_obstack_init (&block_aux_obstack); 655 initialized = 1; 656 } 657 else 658 /* Check whether AUX data are still allocated. */ 659 gcc_assert (!first_block_aux_obj); 660 661 first_block_aux_obj = obstack_alloc (&block_aux_obstack, 0); 662 if (size) 663 { 664 basic_block bb; 665 666 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) 667 alloc_aux_for_block (bb, size); 668 } 669} 670 671/* Clear AUX pointers of all blocks. */ 672 673void 674clear_aux_for_blocks (void) 675{ 676 basic_block bb; 677 678 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) 679 bb->aux = NULL; 680} 681 682/* Free data allocated in block_aux_obstack and clear AUX pointers 683 of all blocks. */ 684 685void 686free_aux_for_blocks (void) 687{ 688 gcc_assert (first_block_aux_obj); 689 obstack_free (&block_aux_obstack, first_block_aux_obj); 690 first_block_aux_obj = NULL; 691 692 clear_aux_for_blocks (); 693} 694 695/* Allocate a memory edge of SIZE as BB->aux. The obstack must 696 be first initialized by alloc_aux_for_edges. */ 697 698inline void 699alloc_aux_for_edge (edge e, int size) 700{ 701 /* Verify that aux field is clear. */ 702 gcc_assert (!e->aux && first_edge_aux_obj); 703 e->aux = obstack_alloc (&edge_aux_obstack, size); 704 memset (e->aux, 0, size); 705} 706 707/* Initialize the edge_aux_obstack and if SIZE is nonzero, call 708 alloc_aux_for_edge for each basic edge. */ 709 710void 711alloc_aux_for_edges (int size) 712{ 713 static int initialized; 714 715 if (!initialized) 716 { 717 gcc_obstack_init (&edge_aux_obstack); 718 initialized = 1; 719 } 720 else 721 /* Check whether AUX data are still allocated. */ 722 gcc_assert (!first_edge_aux_obj); 723 724 first_edge_aux_obj = obstack_alloc (&edge_aux_obstack, 0); 725 if (size) 726 { 727 basic_block bb; 728 729 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) 730 { 731 edge e; 732 edge_iterator ei; 733 734 FOR_EACH_EDGE (e, ei, bb->succs) 735 alloc_aux_for_edge (e, size); 736 } 737 } 738} 739 740/* Clear AUX pointers of all edges. */ 741 742void 743clear_aux_for_edges (void) 744{ 745 basic_block bb; 746 edge e; 747 748 FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, EXIT_BLOCK_PTR, next_bb) 749 { 750 edge_iterator ei; 751 FOR_EACH_EDGE (e, ei, bb->succs) 752 e->aux = NULL; 753 } 754} 755 756/* Free data allocated in edge_aux_obstack and clear AUX pointers 757 of all edges. */ 758 759void 760free_aux_for_edges (void) 761{ 762 gcc_assert (first_edge_aux_obj); 763 obstack_free (&edge_aux_obstack, first_edge_aux_obj); 764 first_edge_aux_obj = NULL; 765 766 clear_aux_for_edges (); 767} 768 769void 770debug_bb (basic_block bb) 771{ 772 dump_bb (bb, stderr, 0); 773} 774 775basic_block 776debug_bb_n (int n) 777{ 778 basic_block bb = BASIC_BLOCK (n); 779 dump_bb (bb, stderr, 0); 780 return bb; 781} 782 783/* Dumps cfg related information about basic block BB to FILE. */ 784 785static void 786dump_cfg_bb_info (FILE *file, basic_block bb) 787{ 788 unsigned i; 789 edge_iterator ei; 790 bool first = true; 791 static const char * const bb_bitnames[] = 792 { 793 "dirty", "new", "reachable", "visited", "irreducible_loop", "superblock" 794 }; 795 const unsigned n_bitnames = sizeof (bb_bitnames) / sizeof (char *); 796 edge e; 797 798 fprintf (file, "Basic block %d", bb->index); 799 for (i = 0; i < n_bitnames; i++) 800 if (bb->flags & (1 << i)) 801 { 802 if (first) 803 fprintf (file, " ("); 804 else 805 fprintf (file, ", "); 806 first = false; 807 fprintf (file, bb_bitnames[i]); 808 } 809 if (!first) 810 fprintf (file, ")"); 811 fprintf (file, "\n"); 812 813 fprintf (file, "Predecessors: "); 814 FOR_EACH_EDGE (e, ei, bb->preds) 815 dump_edge_info (file, e, 0); 816 817 fprintf (file, "\nSuccessors: "); 818 FOR_EACH_EDGE (e, ei, bb->succs) 819 dump_edge_info (file, e, 1); 820 fprintf (file, "\n\n"); 821} 822 823/* Dumps a brief description of cfg to FILE. */ 824 825void 826brief_dump_cfg (FILE *file) 827{ 828 basic_block bb; 829 830 FOR_EACH_BB (bb) 831 { 832 dump_cfg_bb_info (file, bb); 833 } 834} 835 836/* An edge originally destinating BB of FREQUENCY and COUNT has been proved to 837 leave the block by TAKEN_EDGE. Update profile of BB such that edge E can be 838 redirected to destination of TAKEN_EDGE. 839 840 This function may leave the profile inconsistent in the case TAKEN_EDGE 841 frequency or count is believed to be lower than FREQUENCY or COUNT 842 respectively. */ 843void 844update_bb_profile_for_threading (basic_block bb, int edge_frequency, 845 gcov_type count, edge taken_edge) 846{ 847 edge c; 848 int prob; 849 edge_iterator ei; 850 851 bb->count -= count; 852 if (bb->count < 0) 853 { 854 if (dump_file) 855 fprintf (dump_file, "bb %i count became negative after threading", 856 bb->index); 857 bb->count = 0; 858 } 859 860 /* Compute the probability of TAKEN_EDGE being reached via threaded edge. 861 Watch for overflows. */ 862 if (bb->frequency) 863 prob = edge_frequency * REG_BR_PROB_BASE / bb->frequency; 864 else 865 prob = 0; 866 if (prob > taken_edge->probability) 867 { 868 if (dump_file) 869 fprintf (dump_file, "Jump threading proved probability of edge " 870 "%i->%i too small (it is %i, should be %i).\n", 871 taken_edge->src->index, taken_edge->dest->index, 872 taken_edge->probability, prob); 873 prob = taken_edge->probability; 874 } 875 876 /* Now rescale the probabilities. */ 877 taken_edge->probability -= prob; 878 prob = REG_BR_PROB_BASE - prob; 879 bb->frequency -= edge_frequency; 880 if (bb->frequency < 0) 881 bb->frequency = 0; 882 if (prob <= 0) 883 { 884 if (dump_file) 885 fprintf (dump_file, "Edge frequencies of bb %i has been reset, " 886 "frequency of block should end up being 0, it is %i\n", 887 bb->index, bb->frequency); 888 EDGE_SUCC (bb, 0)->probability = REG_BR_PROB_BASE; 889 ei = ei_start (bb->succs); 890 ei_next (&ei); 891 for (; (c = ei_safe_edge (ei)); ei_next (&ei)) 892 c->probability = 0; 893 } 894 else if (prob != REG_BR_PROB_BASE) 895 { 896 int scale = RDIV (65536 * REG_BR_PROB_BASE, prob); 897 898 FOR_EACH_EDGE (c, ei, bb->succs) 899 { 900 c->probability = RDIV (c->probability * scale, 65536); 901 if (c->probability > REG_BR_PROB_BASE) 902 c->probability = REG_BR_PROB_BASE; 903 } 904 } 905 906 gcc_assert (bb == taken_edge->src); 907 taken_edge->count -= count; 908 if (taken_edge->count < 0) 909 { 910 if (dump_file) 911 fprintf (dump_file, "edge %i->%i count became negative after threading", 912 taken_edge->src->index, taken_edge->dest->index); 913 taken_edge->count = 0; 914 } 915} 916 917/* Multiply all frequencies of basic blocks in array BBS of length NBBS 918 by NUM/DEN, in int arithmetic. May lose some accuracy. */ 919void 920scale_bbs_frequencies_int (basic_block *bbs, int nbbs, int num, int den) 921{ 922 int i; 923 edge e; 924 if (num < 0) 925 num = 0; 926 if (num > den) 927 return; 928 /* Assume that the users are producing the fraction from frequencies 929 that never grow far enough to risk arithmetic overflow. */ 930 gcc_assert (num < 65536); 931 for (i = 0; i < nbbs; i++) 932 { 933 edge_iterator ei; 934 bbs[i]->frequency = RDIV (bbs[i]->frequency * num, den); 935 bbs[i]->count = RDIV (bbs[i]->count * num, den); 936 FOR_EACH_EDGE (e, ei, bbs[i]->succs) 937 e->count = RDIV (e->count * num, den); 938 } 939} 940 941/* numbers smaller than this value are safe to multiply without getting 942 64bit overflow. */ 943#define MAX_SAFE_MULTIPLIER (1 << (sizeof (HOST_WIDEST_INT) * 4 - 1)) 944 945/* Multiply all frequencies of basic blocks in array BBS of length NBBS 946 by NUM/DEN, in gcov_type arithmetic. More accurate than previous 947 function but considerably slower. */ 948void 949scale_bbs_frequencies_gcov_type (basic_block *bbs, int nbbs, gcov_type num, 950 gcov_type den) 951{ 952 int i; 953 edge e; 954 gcov_type fraction = RDIV (num * 65536, den); 955 956 gcc_assert (fraction >= 0); 957 958 if (num < MAX_SAFE_MULTIPLIER) 959 for (i = 0; i < nbbs; i++) 960 { 961 edge_iterator ei; 962 bbs[i]->frequency = RDIV (bbs[i]->frequency * num, den); 963 if (bbs[i]->count <= MAX_SAFE_MULTIPLIER) 964 bbs[i]->count = RDIV (bbs[i]->count * num, den); 965 else 966 bbs[i]->count = RDIV (bbs[i]->count * fraction, 65536); 967 FOR_EACH_EDGE (e, ei, bbs[i]->succs) 968 if (bbs[i]->count <= MAX_SAFE_MULTIPLIER) 969 e->count = RDIV (e->count * num, den); 970 else 971 e->count = RDIV (e->count * fraction, 65536); 972 } 973 else 974 for (i = 0; i < nbbs; i++) 975 { 976 edge_iterator ei; 977 if (sizeof (gcov_type) > sizeof (int)) 978 bbs[i]->frequency = RDIV (bbs[i]->frequency * num, den); 979 else 980 bbs[i]->frequency = RDIV (bbs[i]->frequency * fraction, 65536); 981 bbs[i]->count = RDIV (bbs[i]->count * fraction, 65536); 982 FOR_EACH_EDGE (e, ei, bbs[i]->succs) 983 e->count = RDIV (e->count * fraction, 65536); 984 } 985} 986 987/* Data structures used to maintain mapping between basic blocks and 988 copies. */ 989static htab_t bb_original; 990static htab_t bb_copy; 991static alloc_pool original_copy_bb_pool; 992 993struct htab_bb_copy_original_entry 994{ 995 /* Block we are attaching info to. */ 996 int index1; 997 /* Index of original or copy (depending on the hashtable) */ 998 int index2; 999}; 1000 1001static hashval_t 1002bb_copy_original_hash (const void *p) 1003{ 1004 struct htab_bb_copy_original_entry *data 1005 = ((struct htab_bb_copy_original_entry *)p); 1006 1007 return data->index1; 1008} 1009static int 1010bb_copy_original_eq (const void *p, const void *q) 1011{ 1012 struct htab_bb_copy_original_entry *data 1013 = ((struct htab_bb_copy_original_entry *)p); 1014 struct htab_bb_copy_original_entry *data2 1015 = ((struct htab_bb_copy_original_entry *)q); 1016 1017 return data->index1 == data2->index1; 1018} 1019 1020/* Initialize the data structures to maintain mapping between blocks 1021 and its copies. */ 1022void 1023initialize_original_copy_tables (void) 1024{ 1025 gcc_assert (!original_copy_bb_pool); 1026 original_copy_bb_pool 1027 = create_alloc_pool ("original_copy", 1028 sizeof (struct htab_bb_copy_original_entry), 10); 1029 bb_original = htab_create (10, bb_copy_original_hash, 1030 bb_copy_original_eq, NULL); 1031 bb_copy = htab_create (10, bb_copy_original_hash, bb_copy_original_eq, NULL); 1032} 1033 1034/* Free the data structures to maintain mapping between blocks and 1035 its copies. */ 1036void 1037free_original_copy_tables (void) 1038{ 1039 gcc_assert (original_copy_bb_pool); 1040 htab_delete (bb_copy); 1041 htab_delete (bb_original); 1042 free_alloc_pool (original_copy_bb_pool); 1043 bb_copy = NULL; 1044 bb_original = NULL; 1045 original_copy_bb_pool = NULL; 1046} 1047 1048/* Set original for basic block. Do nothing when data structures are not 1049 initialized so passes not needing this don't need to care. */ 1050void 1051set_bb_original (basic_block bb, basic_block original) 1052{ 1053 if (original_copy_bb_pool) 1054 { 1055 struct htab_bb_copy_original_entry **slot; 1056 struct htab_bb_copy_original_entry key; 1057 1058 key.index1 = bb->index; 1059 slot = 1060 (struct htab_bb_copy_original_entry **) htab_find_slot (bb_original, 1061 &key, INSERT); 1062 if (*slot) 1063 (*slot)->index2 = original->index; 1064 else 1065 { 1066 *slot = pool_alloc (original_copy_bb_pool); 1067 (*slot)->index1 = bb->index; 1068 (*slot)->index2 = original->index; 1069 } 1070 } 1071} 1072 1073/* Get the original basic block. */ 1074basic_block 1075get_bb_original (basic_block bb) 1076{ 1077 struct htab_bb_copy_original_entry *entry; 1078 struct htab_bb_copy_original_entry key; 1079 1080 gcc_assert (original_copy_bb_pool); 1081 1082 key.index1 = bb->index; 1083 entry = (struct htab_bb_copy_original_entry *) htab_find (bb_original, &key); 1084 if (entry) 1085 return BASIC_BLOCK (entry->index2); 1086 else 1087 return NULL; 1088} 1089 1090/* Set copy for basic block. Do nothing when data structures are not 1091 initialized so passes not needing this don't need to care. */ 1092void 1093set_bb_copy (basic_block bb, basic_block copy) 1094{ 1095 if (original_copy_bb_pool) 1096 { 1097 struct htab_bb_copy_original_entry **slot; 1098 struct htab_bb_copy_original_entry key; 1099 1100 key.index1 = bb->index; 1101 slot = 1102 (struct htab_bb_copy_original_entry **) htab_find_slot (bb_copy, 1103 &key, INSERT); 1104 if (*slot) 1105 (*slot)->index2 = copy->index; 1106 else 1107 { 1108 *slot = pool_alloc (original_copy_bb_pool); 1109 (*slot)->index1 = bb->index; 1110 (*slot)->index2 = copy->index; 1111 } 1112 } 1113} 1114 1115/* Get the copy of basic block. */ 1116basic_block 1117get_bb_copy (basic_block bb) 1118{ 1119 struct htab_bb_copy_original_entry *entry; 1120 struct htab_bb_copy_original_entry key; 1121 1122 gcc_assert (original_copy_bb_pool); 1123 1124 key.index1 = bb->index; 1125 entry = (struct htab_bb_copy_original_entry *) htab_find (bb_copy, &key); 1126 if (entry) 1127 return BASIC_BLOCK (entry->index2); 1128 else 1129 return NULL; 1130} 1131