1 /* Define control flow data structures for the CFG. 2 Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 3 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. 4 5 This file is part of GCC. 6 7 GCC is free software; you can redistribute it and/or modify it under 8 the terms of the GNU General Public License as published by the Free 9 Software Foundation; either version 3, or (at your option) any later 10 version. 11 12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY 13 WARRANTY; without even the implied warranty of MERCHANTABILITY or 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 15 for more details. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 #ifndef GCC_BASIC_BLOCK_H 22 #define GCC_BASIC_BLOCK_H 23 24 #include "predict.h" 25 #include "vec.h" 26 #include "function.h" 27 28 /* Type we use to hold basic block counters. Should be at least 29 64bit. Although a counter cannot be negative, we use a signed 30 type, because erroneous negative counts can be generated when the 31 flow graph is manipulated by various optimizations. A signed type 32 makes those easy to detect. */ 33 typedef HOST_WIDEST_INT gcov_type; 34 35 /* Control flow edge information. */ 36 struct GTY(()) edge_def { 37 /* The two blocks at the ends of the edge. */ 38 struct basic_block_def *src; 39 struct basic_block_def *dest; 40 41 /* Instructions queued on the edge. */ 42 union edge_def_insns { 43 gimple_seq GTY ((tag ("true"))) g; 44 rtx GTY ((tag ("false"))) r; 45 } GTY ((desc ("current_ir_type () == IR_GIMPLE"))) insns; 46 47 /* Auxiliary info specific to a pass. */ 48 PTR GTY ((skip (""))) aux; 49 50 /* Location of any goto implicit in the edge and associated BLOCK. */ 51 tree goto_block; 52 location_t goto_locus; 53 54 /* The index number corresponding to this edge in the edge vector 55 dest->preds. */ 56 unsigned int dest_idx; 57 58 int flags; /* see EDGE_* below */ 59 int probability; /* biased by REG_BR_PROB_BASE */ 60 gcov_type count; /* Expected number of executions calculated 61 in profile.c */ 62 }; 63 64 DEF_VEC_P(edge); 65 DEF_VEC_ALLOC_P(edge,gc); 66 DEF_VEC_ALLOC_P(edge,heap); 67 68 #define EDGE_FALLTHRU 1 /* 'Straight line' flow */ 69 #define EDGE_ABNORMAL 2 /* Strange flow, like computed 70 label, or eh */ 71 #define EDGE_ABNORMAL_CALL 4 /* Call with abnormal exit 72 like an exception, or sibcall */ 73 #define EDGE_EH 8 /* Exception throw */ 74 #define EDGE_FAKE 16 /* Not a real edge (profile.c) */ 75 #define EDGE_DFS_BACK 32 /* A backwards edge */ 76 #define EDGE_CAN_FALLTHRU 64 /* Candidate for straight line 77 flow. */ 78 #define EDGE_IRREDUCIBLE_LOOP 128 /* Part of irreducible loop. */ 79 #define EDGE_SIBCALL 256 /* Edge from sibcall to exit. */ 80 #define EDGE_LOOP_EXIT 512 /* Exit of a loop. */ 81 #define EDGE_TRUE_VALUE 1024 /* Edge taken when controlling 82 predicate is nonzero. */ 83 #define EDGE_FALSE_VALUE 2048 /* Edge taken when controlling 84 predicate is zero. */ 85 #define EDGE_EXECUTABLE 4096 /* Edge is executable. Only 86 valid during SSA-CCP. */ 87 #define EDGE_CROSSING 8192 /* Edge crosses between hot 88 and cold sections, when we 89 do partitioning. */ 90 #define EDGE_ALL_FLAGS 16383 91 92 #define EDGE_COMPLEX (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH) 93 94 /* Counter summary from the last set of coverage counts read by 95 profile.c. */ 96 extern const struct gcov_ctr_summary *profile_info; 97 98 /* Declared in cfgloop.h. */ 99 struct loop; 100 101 /* Declared in tree-flow.h. */ 102 struct rtl_bb_info; 103 104 /* A basic block is a sequence of instructions with only entry and 105 only one exit. If any one of the instructions are executed, they 106 will all be executed, and in sequence from first to last. 107 108 There may be COND_EXEC instructions in the basic block. The 109 COND_EXEC *instructions* will be executed -- but if the condition 110 is false the conditionally executed *expressions* will of course 111 not be executed. We don't consider the conditionally executed 112 expression (which might have side-effects) to be in a separate 113 basic block because the program counter will always be at the same 114 location after the COND_EXEC instruction, regardless of whether the 115 condition is true or not. 116 117 Basic blocks need not start with a label nor end with a jump insn. 118 For example, a previous basic block may just "conditionally fall" 119 into the succeeding basic block, and the last basic block need not 120 end with a jump insn. Block 0 is a descendant of the entry block. 121 122 A basic block beginning with two labels cannot have notes between 123 the labels. 124 125 Data for jump tables are stored in jump_insns that occur in no 126 basic block even though these insns can follow or precede insns in 127 basic blocks. */ 128 129 /* Basic block information indexed by block number. */ 130 struct GTY((chain_next ("%h.next_bb"), chain_prev ("%h.prev_bb"))) basic_block_def { 131 /* The edges into and out of the block. */ 132 VEC(edge,gc) *preds; 133 VEC(edge,gc) *succs; 134 135 /* Auxiliary info specific to a pass. */ 136 PTR GTY ((skip (""))) aux; 137 138 /* Innermost loop containing the block. */ 139 struct loop *loop_father; 140 141 /* The dominance and postdominance information node. */ 142 struct et_node * GTY ((skip (""))) dom[2]; 143 144 /* Previous and next blocks in the chain. */ 145 struct basic_block_def *prev_bb; 146 struct basic_block_def *next_bb; 147 148 union basic_block_il_dependent { 149 struct gimple_bb_info * GTY ((tag ("0"))) gimple; 150 struct rtl_bb_info * GTY ((tag ("1"))) rtl; 151 } GTY ((desc ("((%1.flags & BB_RTL) != 0)"))) il; 152 153 /* Expected number of executions: calculated in profile.c. */ 154 gcov_type count; 155 156 /* The index of this block. */ 157 int index; 158 159 /* The loop depth of this block. */ 160 int loop_depth; 161 162 /* Expected frequency. Normalized to be in range 0 to BB_FREQ_MAX. */ 163 int frequency; 164 165 /* Various flags. See BB_* below. */ 166 int flags; 167 }; 168 169 struct GTY(()) rtl_bb_info { 170 /* The first and last insns of the block. */ 171 rtx head_; 172 rtx end_; 173 174 /* In CFGlayout mode points to insn notes/jumptables to be placed just before 175 and after the block. */ 176 rtx header; 177 rtx footer; 178 179 /* This field is used by the bb-reorder and tracer passes. */ 180 int visited; 181 }; 182 183 struct GTY(()) gimple_bb_info { 184 /* Sequence of statements in this block. */ 185 gimple_seq seq; 186 187 /* PHI nodes for this block. */ 188 gimple_seq phi_nodes; 189 }; 190 191 DEF_VEC_P(basic_block); 192 DEF_VEC_ALLOC_P(basic_block,gc); 193 DEF_VEC_ALLOC_P(basic_block,heap); 194 195 #define BB_FREQ_MAX 10000 196 197 /* Masks for basic_block.flags. 198 199 BB_HOT_PARTITION and BB_COLD_PARTITION should be preserved throughout 200 the compilation, so they are never cleared. 201 202 All other flags may be cleared by clear_bb_flags(). It is generally 203 a bad idea to rely on any flags being up-to-date. */ 204 205 enum bb_flags 206 { 207 /* Only set on blocks that have just been created by create_bb. */ 208 BB_NEW = 1 << 0, 209 210 /* Set by find_unreachable_blocks. Do not rely on this being set in any 211 pass. */ 212 BB_REACHABLE = 1 << 1, 213 214 /* Set for blocks in an irreducible loop by loop analysis. */ 215 BB_IRREDUCIBLE_LOOP = 1 << 2, 216 217 /* Set on blocks that may actually not be single-entry single-exit block. */ 218 BB_SUPERBLOCK = 1 << 3, 219 220 /* Set on basic blocks that the scheduler should not touch. This is used 221 by SMS to prevent other schedulers from messing with the loop schedule. */ 222 BB_DISABLE_SCHEDULE = 1 << 4, 223 224 /* Set on blocks that should be put in a hot section. */ 225 BB_HOT_PARTITION = 1 << 5, 226 227 /* Set on blocks that should be put in a cold section. */ 228 BB_COLD_PARTITION = 1 << 6, 229 230 /* Set on block that was duplicated. */ 231 BB_DUPLICATED = 1 << 7, 232 233 /* Set if the label at the top of this block is the target of a non-local goto. */ 234 BB_NON_LOCAL_GOTO_TARGET = 1 << 8, 235 236 /* Set on blocks that are in RTL format. */ 237 BB_RTL = 1 << 9 , 238 239 /* Set on blocks that are forwarder blocks. 240 Only used in cfgcleanup.c. */ 241 BB_FORWARDER_BLOCK = 1 << 10, 242 243 /* Set on blocks that cannot be threaded through. 244 Only used in cfgcleanup.c. */ 245 BB_NONTHREADABLE_BLOCK = 1 << 11, 246 247 /* Set on blocks that were modified in some way. This bit is set in 248 df_set_bb_dirty, but not cleared by df_analyze, so it can be used 249 to test whether a block has been modified prior to a df_analyze 250 call. */ 251 BB_MODIFIED = 1 << 12 252 }; 253 254 /* Dummy flag for convenience in the hot/cold partitioning code. */ 255 #define BB_UNPARTITIONED 0 256 257 /* Partitions, to be used when partitioning hot and cold basic blocks into 258 separate sections. */ 259 #define BB_PARTITION(bb) ((bb)->flags & (BB_HOT_PARTITION|BB_COLD_PARTITION)) 260 #define BB_SET_PARTITION(bb, part) do { \ 261 basic_block bb_ = (bb); \ 262 bb_->flags = ((bb_->flags & ~(BB_HOT_PARTITION|BB_COLD_PARTITION)) \ 263 | (part)); \ 264 } while (0) 265 266 #define BB_COPY_PARTITION(dstbb, srcbb) \ 267 BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb)) 268 269 /* State of dominance information. */ 270 271 enum dom_state 272 { 273 DOM_NONE, /* Not computed at all. */ 274 DOM_NO_FAST_QUERY, /* The data is OK, but the fast query data are not usable. */ 275 DOM_OK /* Everything is ok. */ 276 }; 277 278 /* What sort of profiling information we have. */ 279 enum profile_status_d 280 { 281 PROFILE_ABSENT, 282 PROFILE_GUESSED, 283 PROFILE_READ 284 }; 285 286 /* A structure to group all the per-function control flow graph data. 287 The x_* prefixing is necessary because otherwise references to the 288 fields of this struct are interpreted as the defines for backward 289 source compatibility following the definition of this struct. */ 290 struct GTY(()) control_flow_graph { 291 /* Block pointers for the exit and entry of a function. 292 These are always the head and tail of the basic block list. */ 293 basic_block x_entry_block_ptr; 294 basic_block x_exit_block_ptr; 295 296 /* Index by basic block number, get basic block struct info. */ 297 VEC(basic_block,gc) *x_basic_block_info; 298 299 /* Number of basic blocks in this flow graph. */ 300 int x_n_basic_blocks; 301 302 /* Number of edges in this flow graph. */ 303 int x_n_edges; 304 305 /* The first free basic block number. */ 306 int x_last_basic_block; 307 308 /* UIDs for LABEL_DECLs. */ 309 int last_label_uid; 310 311 /* Mapping of labels to their associated blocks. At present 312 only used for the gimple CFG. */ 313 VEC(basic_block,gc) *x_label_to_block_map; 314 315 enum profile_status_d x_profile_status; 316 317 /* Whether the dominators and the postdominators are available. */ 318 enum dom_state x_dom_computed[2]; 319 320 /* Number of basic blocks in the dominance tree. */ 321 unsigned x_n_bbs_in_dom_tree[2]; 322 323 /* Maximal number of entities in the single jumptable. Used to estimate 324 final flowgraph size. */ 325 int max_jumptable_ents; 326 }; 327 328 /* Defines for accessing the fields of the CFG structure for function FN. */ 329 #define ENTRY_BLOCK_PTR_FOR_FUNCTION(FN) ((FN)->cfg->x_entry_block_ptr) 330 #define EXIT_BLOCK_PTR_FOR_FUNCTION(FN) ((FN)->cfg->x_exit_block_ptr) 331 #define basic_block_info_for_function(FN) ((FN)->cfg->x_basic_block_info) 332 #define n_basic_blocks_for_function(FN) ((FN)->cfg->x_n_basic_blocks) 333 #define n_edges_for_function(FN) ((FN)->cfg->x_n_edges) 334 #define last_basic_block_for_function(FN) ((FN)->cfg->x_last_basic_block) 335 #define label_to_block_map_for_function(FN) ((FN)->cfg->x_label_to_block_map) 336 #define profile_status_for_function(FN) ((FN)->cfg->x_profile_status) 337 338 #define BASIC_BLOCK_FOR_FUNCTION(FN,N) \ 339 (VEC_index (basic_block, basic_block_info_for_function(FN), (N))) 340 #define SET_BASIC_BLOCK_FOR_FUNCTION(FN,N,BB) \ 341 (VEC_replace (basic_block, basic_block_info_for_function(FN), (N), (BB))) 342 343 /* Defines for textual backward source compatibility. */ 344 #define ENTRY_BLOCK_PTR (cfun->cfg->x_entry_block_ptr) 345 #define EXIT_BLOCK_PTR (cfun->cfg->x_exit_block_ptr) 346 #define basic_block_info (cfun->cfg->x_basic_block_info) 347 #define n_basic_blocks (cfun->cfg->x_n_basic_blocks) 348 #define n_edges (cfun->cfg->x_n_edges) 349 #define last_basic_block (cfun->cfg->x_last_basic_block) 350 #define label_to_block_map (cfun->cfg->x_label_to_block_map) 351 #define profile_status (cfun->cfg->x_profile_status) 352 353 #define BASIC_BLOCK(N) (VEC_index (basic_block, basic_block_info, (N))) 354 #define SET_BASIC_BLOCK(N,BB) (VEC_replace (basic_block, basic_block_info, (N), (BB))) 355 356 /* For iterating over basic blocks. */ 357 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \ 358 for (BB = FROM; BB != TO; BB = BB->DIR) 359 360 #define FOR_EACH_BB_FN(BB, FN) \ 361 FOR_BB_BETWEEN (BB, (FN)->cfg->x_entry_block_ptr->next_bb, (FN)->cfg->x_exit_block_ptr, next_bb) 362 363 #define FOR_EACH_BB(BB) FOR_EACH_BB_FN (BB, cfun) 364 365 #define FOR_EACH_BB_REVERSE_FN(BB, FN) \ 366 FOR_BB_BETWEEN (BB, (FN)->cfg->x_exit_block_ptr->prev_bb, (FN)->cfg->x_entry_block_ptr, prev_bb) 367 368 #define FOR_EACH_BB_REVERSE(BB) FOR_EACH_BB_REVERSE_FN(BB, cfun) 369 370 /* For iterating over insns in basic block. */ 371 #define FOR_BB_INSNS(BB, INSN) \ 372 for ((INSN) = BB_HEAD (BB); \ 373 (INSN) && (INSN) != NEXT_INSN (BB_END (BB)); \ 374 (INSN) = NEXT_INSN (INSN)) 375 376 /* For iterating over insns in basic block when we might remove the 377 current insn. */ 378 #define FOR_BB_INSNS_SAFE(BB, INSN, CURR) \ 379 for ((INSN) = BB_HEAD (BB), (CURR) = (INSN) ? NEXT_INSN ((INSN)): NULL; \ 380 (INSN) && (INSN) != NEXT_INSN (BB_END (BB)); \ 381 (INSN) = (CURR), (CURR) = (INSN) ? NEXT_INSN ((INSN)) : NULL) 382 383 #define FOR_BB_INSNS_REVERSE(BB, INSN) \ 384 for ((INSN) = BB_END (BB); \ 385 (INSN) && (INSN) != PREV_INSN (BB_HEAD (BB)); \ 386 (INSN) = PREV_INSN (INSN)) 387 388 #define FOR_BB_INSNS_REVERSE_SAFE(BB, INSN, CURR) \ 389 for ((INSN) = BB_END (BB),(CURR) = (INSN) ? PREV_INSN ((INSN)) : NULL; \ 390 (INSN) && (INSN) != PREV_INSN (BB_HEAD (BB)); \ 391 (INSN) = (CURR), (CURR) = (INSN) ? PREV_INSN ((INSN)) : NULL) 392 393 /* Cycles through _all_ basic blocks, even the fake ones (entry and 394 exit block). */ 395 396 #define FOR_ALL_BB(BB) \ 397 for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb) 398 399 #define FOR_ALL_BB_FN(BB, FN) \ 400 for (BB = ENTRY_BLOCK_PTR_FOR_FUNCTION (FN); BB; BB = BB->next_bb) 401 402 403 /* Stuff for recording basic block info. */ 405 406 #define BB_HEAD(B) (B)->il.rtl->head_ 407 #define BB_END(B) (B)->il.rtl->end_ 408 409 /* Special block numbers [markers] for entry and exit. 410 Neither of them is supposed to hold actual statements. */ 411 #define ENTRY_BLOCK (0) 412 #define EXIT_BLOCK (1) 413 414 /* The two blocks that are always in the cfg. */ 415 #define NUM_FIXED_BLOCKS (2) 416 417 #define set_block_for_insn(INSN, BB) (BLOCK_FOR_INSN (INSN) = BB) 418 419 extern void compute_bb_for_insn (void); 420 extern unsigned int free_bb_for_insn (void); 421 extern void update_bb_for_insn (basic_block); 422 423 extern void insert_insn_on_edge (rtx, edge); 424 basic_block split_edge_and_insert (edge, rtx); 425 426 extern void commit_one_edge_insertion (edge e); 427 extern void commit_edge_insertions (void); 428 429 extern void remove_fake_edges (void); 430 extern void remove_fake_exit_edges (void); 431 extern void add_noreturn_fake_exit_edges (void); 432 extern void connect_infinite_loops_to_exit (void); 433 extern edge unchecked_make_edge (basic_block, basic_block, int); 434 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int); 435 extern edge make_edge (basic_block, basic_block, int); 436 extern edge make_single_succ_edge (basic_block, basic_block, int); 437 extern void remove_edge_raw (edge); 438 extern void redirect_edge_succ (edge, basic_block); 439 extern edge redirect_edge_succ_nodup (edge, basic_block); 440 extern void redirect_edge_pred (edge, basic_block); 441 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block); 442 extern void clear_bb_flags (void); 443 extern int post_order_compute (int *, bool, bool); 444 extern int inverted_post_order_compute (int *); 445 extern int pre_and_rev_post_order_compute (int *, int *, bool); 446 extern int dfs_enumerate_from (basic_block, int, 447 bool (*)(const_basic_block, const void *), 448 basic_block *, int, const void *); 449 extern void compute_dominance_frontiers (struct bitmap_head_def *); 450 extern bitmap compute_idf (bitmap, struct bitmap_head_def *); 451 extern void dump_bb_info (basic_block, bool, bool, int, const char *, FILE *); 452 extern void dump_edge_info (FILE *, edge, int); 453 extern void brief_dump_cfg (FILE *); 454 extern void clear_edges (void); 455 extern void scale_bbs_frequencies_int (basic_block *, int, int, int); 456 extern void scale_bbs_frequencies_gcov_type (basic_block *, int, gcov_type, 457 gcov_type); 458 459 /* Structure to group all of the information to process IF-THEN and 460 IF-THEN-ELSE blocks for the conditional execution support. This 461 needs to be in a public file in case the IFCVT macros call 462 functions passing the ce_if_block data structure. */ 463 464 typedef struct ce_if_block 465 { 466 basic_block test_bb; /* First test block. */ 467 basic_block then_bb; /* THEN block. */ 468 basic_block else_bb; /* ELSE block or NULL. */ 469 basic_block join_bb; /* Join THEN/ELSE blocks. */ 470 basic_block last_test_bb; /* Last bb to hold && or || tests. */ 471 int num_multiple_test_blocks; /* # of && and || basic blocks. */ 472 int num_and_and_blocks; /* # of && blocks. */ 473 int num_or_or_blocks; /* # of || blocks. */ 474 int num_multiple_test_insns; /* # of insns in && and || blocks. */ 475 int and_and_p; /* Complex test is &&. */ 476 int num_then_insns; /* # of insns in THEN block. */ 477 int num_else_insns; /* # of insns in ELSE block. */ 478 int pass; /* Pass number. */ 479 480 #ifdef IFCVT_EXTRA_FIELDS 481 IFCVT_EXTRA_FIELDS /* Any machine dependent fields. */ 482 #endif 483 484 } ce_if_block_t; 485 486 /* This structure maintains an edge list vector. */ 487 struct edge_list 488 { 489 int num_blocks; 490 int num_edges; 491 edge *index_to_edge; 492 }; 493 494 /* The base value for branch probability notes and edge probabilities. */ 495 #define REG_BR_PROB_BASE 10000 496 497 /* This is the value which indicates no edge is present. */ 498 #define EDGE_INDEX_NO_EDGE -1 499 500 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE 501 if there is no edge between the 2 basic blocks. */ 502 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ))) 503 504 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic 505 block which is either the pred or succ end of the indexed edge. */ 506 #define INDEX_EDGE_PRED_BB(el, index) ((el)->index_to_edge[(index)]->src) 507 #define INDEX_EDGE_SUCC_BB(el, index) ((el)->index_to_edge[(index)]->dest) 508 509 /* INDEX_EDGE returns a pointer to the edge. */ 510 #define INDEX_EDGE(el, index) ((el)->index_to_edge[(index)]) 511 512 /* Number of edges in the compressed edge list. */ 513 #define NUM_EDGES(el) ((el)->num_edges) 514 515 /* BB is assumed to contain conditional jump. Return the fallthru edge. */ 516 #define FALLTHRU_EDGE(bb) (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \ 517 ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1)) 518 519 /* BB is assumed to contain conditional jump. Return the branch edge. */ 520 #define BRANCH_EDGE(bb) (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \ 521 ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0)) 522 523 /* Return expected execution frequency of the edge E. */ 524 #define EDGE_FREQUENCY(e) (((e)->src->frequency \ 525 * (e)->probability \ 526 + REG_BR_PROB_BASE / 2) \ 527 / REG_BR_PROB_BASE) 528 529 /* Return nonzero if edge is critical. */ 530 #define EDGE_CRITICAL_P(e) (EDGE_COUNT ((e)->src->succs) >= 2 \ 531 && EDGE_COUNT ((e)->dest->preds) >= 2) 532 533 #define EDGE_COUNT(ev) VEC_length (edge, (ev)) 534 #define EDGE_I(ev,i) VEC_index (edge, (ev), (i)) 535 #define EDGE_PRED(bb,i) VEC_index (edge, (bb)->preds, (i)) 536 #define EDGE_SUCC(bb,i) VEC_index (edge, (bb)->succs, (i)) 537 538 /* Returns true if BB has precisely one successor. */ 539 540 static inline bool 541 single_succ_p (const_basic_block bb) 542 { 543 return EDGE_COUNT (bb->succs) == 1; 544 } 545 546 /* Returns true if BB has precisely one predecessor. */ 547 548 static inline bool 549 single_pred_p (const_basic_block bb) 550 { 551 return EDGE_COUNT (bb->preds) == 1; 552 } 553 554 /* Returns the single successor edge of basic block BB. Aborts if 555 BB does not have exactly one successor. */ 556 557 static inline edge 558 single_succ_edge (const_basic_block bb) 559 { 560 gcc_checking_assert (single_succ_p (bb)); 561 return EDGE_SUCC (bb, 0); 562 } 563 564 /* Returns the single predecessor edge of basic block BB. Aborts 565 if BB does not have exactly one predecessor. */ 566 567 static inline edge 568 single_pred_edge (const_basic_block bb) 569 { 570 gcc_checking_assert (single_pred_p (bb)); 571 return EDGE_PRED (bb, 0); 572 } 573 574 /* Returns the single successor block of basic block BB. Aborts 575 if BB does not have exactly one successor. */ 576 577 static inline basic_block 578 single_succ (const_basic_block bb) 579 { 580 return single_succ_edge (bb)->dest; 581 } 582 583 /* Returns the single predecessor block of basic block BB. Aborts 584 if BB does not have exactly one predecessor.*/ 585 586 static inline basic_block 587 single_pred (const_basic_block bb) 588 { 589 return single_pred_edge (bb)->src; 590 } 591 592 /* Iterator object for edges. */ 593 594 typedef struct { 595 unsigned index; 596 VEC(edge,gc) **container; 597 } edge_iterator; 598 599 static inline VEC(edge,gc) * 600 ei_container (edge_iterator i) 601 { 602 gcc_checking_assert (i.container); 603 return *i.container; 604 } 605 606 #define ei_start(iter) ei_start_1 (&(iter)) 607 #define ei_last(iter) ei_last_1 (&(iter)) 608 609 /* Return an iterator pointing to the start of an edge vector. */ 610 static inline edge_iterator 611 ei_start_1 (VEC(edge,gc) **ev) 612 { 613 edge_iterator i; 614 615 i.index = 0; 616 i.container = ev; 617 618 return i; 619 } 620 621 /* Return an iterator pointing to the last element of an edge 622 vector. */ 623 static inline edge_iterator 624 ei_last_1 (VEC(edge,gc) **ev) 625 { 626 edge_iterator i; 627 628 i.index = EDGE_COUNT (*ev) - 1; 629 i.container = ev; 630 631 return i; 632 } 633 634 /* Is the iterator `i' at the end of the sequence? */ 635 static inline bool 636 ei_end_p (edge_iterator i) 637 { 638 return (i.index == EDGE_COUNT (ei_container (i))); 639 } 640 641 /* Is the iterator `i' at one position before the end of the 642 sequence? */ 643 static inline bool 644 ei_one_before_end_p (edge_iterator i) 645 { 646 return (i.index + 1 == EDGE_COUNT (ei_container (i))); 647 } 648 649 /* Advance the iterator to the next element. */ 650 static inline void 651 ei_next (edge_iterator *i) 652 { 653 gcc_checking_assert (i->index < EDGE_COUNT (ei_container (*i))); 654 i->index++; 655 } 656 657 /* Move the iterator to the previous element. */ 658 static inline void 659 ei_prev (edge_iterator *i) 660 { 661 gcc_checking_assert (i->index > 0); 662 i->index--; 663 } 664 665 /* Return the edge pointed to by the iterator `i'. */ 666 static inline edge 667 ei_edge (edge_iterator i) 668 { 669 return EDGE_I (ei_container (i), i.index); 670 } 671 672 /* Return an edge pointed to by the iterator. Do it safely so that 673 NULL is returned when the iterator is pointing at the end of the 674 sequence. */ 675 static inline edge 676 ei_safe_edge (edge_iterator i) 677 { 678 return !ei_end_p (i) ? ei_edge (i) : NULL; 679 } 680 681 /* Return 1 if we should continue to iterate. Return 0 otherwise. 682 *Edge P is set to the next edge if we are to continue to iterate 683 and NULL otherwise. */ 684 685 static inline bool 686 ei_cond (edge_iterator ei, edge *p) 687 { 688 if (!ei_end_p (ei)) 689 { 690 *p = ei_edge (ei); 691 return 1; 692 } 693 else 694 { 695 *p = NULL; 696 return 0; 697 } 698 } 699 700 /* This macro serves as a convenient way to iterate each edge in a 701 vector of predecessor or successor edges. It must not be used when 702 an element might be removed during the traversal, otherwise 703 elements will be missed. Instead, use a for-loop like that shown 704 in the following pseudo-code: 705 706 FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) 707 { 708 IF (e != taken_edge) 709 remove_edge (e); 710 ELSE 711 ei_next (&ei); 712 } 713 */ 714 715 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC) \ 716 for ((ITER) = ei_start ((EDGE_VEC)); \ 717 ei_cond ((ITER), &(EDGE)); \ 718 ei_next (&(ITER))) 719 720 struct edge_list * create_edge_list (void); 721 void free_edge_list (struct edge_list *); 722 void print_edge_list (FILE *, struct edge_list *); 723 void verify_edge_list (FILE *, struct edge_list *); 724 int find_edge_index (struct edge_list *, basic_block, basic_block); 725 edge find_edge (basic_block, basic_block); 726 727 #define CLEANUP_EXPENSIVE 1 /* Do relatively expensive optimizations 728 except for edge forwarding */ 729 #define CLEANUP_CROSSJUMP 2 /* Do crossjumping. */ 730 #define CLEANUP_POST_REGSTACK 4 /* We run after reg-stack and need 731 to care REG_DEAD notes. */ 732 #define CLEANUP_THREADING 8 /* Do jump threading. */ 733 #define CLEANUP_NO_INSN_DEL 16 /* Do not try to delete trivially dead 734 insns. */ 735 #define CLEANUP_CFGLAYOUT 32 /* Do cleanup in cfglayout mode. */ 736 737 /* In lcm.c */ 738 extern struct edge_list *pre_edge_lcm (int, sbitmap *, sbitmap *, 739 sbitmap *, sbitmap *, sbitmap **, 740 sbitmap **); 741 extern struct edge_list *pre_edge_rev_lcm (int, sbitmap *, 742 sbitmap *, sbitmap *, 743 sbitmap *, sbitmap **, 744 sbitmap **); 745 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *); 746 747 /* In predict.c */ 748 extern bool maybe_hot_count_p (gcov_type); 749 extern bool maybe_hot_bb_p (const_basic_block); 750 extern bool maybe_hot_edge_p (edge); 751 extern bool probably_never_executed_bb_p (const_basic_block); 752 extern bool optimize_bb_for_size_p (const_basic_block); 753 extern bool optimize_bb_for_speed_p (const_basic_block); 754 extern bool optimize_edge_for_size_p (edge); 755 extern bool optimize_edge_for_speed_p (edge); 756 extern bool optimize_loop_for_size_p (struct loop *); 757 extern bool optimize_loop_for_speed_p (struct loop *); 758 extern bool optimize_loop_nest_for_size_p (struct loop *); 759 extern bool optimize_loop_nest_for_speed_p (struct loop *); 760 extern bool gimple_predicted_by_p (const_basic_block, enum br_predictor); 761 extern bool rtl_predicted_by_p (const_basic_block, enum br_predictor); 762 extern void gimple_predict_edge (edge, enum br_predictor, int); 763 extern void rtl_predict_edge (edge, enum br_predictor, int); 764 extern void predict_edge_def (edge, enum br_predictor, enum prediction); 765 extern void guess_outgoing_edge_probabilities (basic_block); 766 extern void remove_predictions_associated_with_edge (edge); 767 extern bool edge_probability_reliable_p (const_edge); 768 extern bool br_prob_note_reliable_p (const_rtx); 769 extern bool predictable_edge_p (edge); 770 771 /* In cfg.c */ 772 extern void init_flow (struct function *); 773 extern void debug_bb (basic_block); 774 extern basic_block debug_bb_n (int); 775 extern void expunge_block (basic_block); 776 extern void link_block (basic_block, basic_block); 777 extern void unlink_block (basic_block); 778 extern void compact_blocks (void); 779 extern basic_block alloc_block (void); 780 extern void alloc_aux_for_blocks (int); 781 extern void clear_aux_for_blocks (void); 782 extern void free_aux_for_blocks (void); 783 extern void alloc_aux_for_edges (int); 784 extern void clear_aux_for_edges (void); 785 extern void free_aux_for_edges (void); 786 787 /* In cfganal.c */ 788 extern void find_unreachable_blocks (void); 789 extern bool forwarder_block_p (const_basic_block); 790 extern bool can_fallthru (basic_block, basic_block); 791 extern bool could_fall_through (basic_block, basic_block); 792 extern void flow_nodes_print (const char *, const_sbitmap, FILE *); 793 extern void flow_edge_list_print (const char *, const edge *, int, FILE *); 794 795 /* In cfgrtl.c */ 796 extern basic_block force_nonfallthru (edge); 797 extern rtx block_label (basic_block); 798 extern bool purge_all_dead_edges (void); 799 extern bool purge_dead_edges (basic_block); 800 801 /* In cfgbuild.c. */ 802 extern void find_many_sub_basic_blocks (sbitmap); 803 extern void rtl_make_eh_edge (sbitmap, basic_block, rtx); 804 805 /* In cfgcleanup.c. */ 806 extern bool cleanup_cfg (int); 807 extern int flow_find_cross_jump (basic_block, basic_block, rtx *, rtx *); 808 extern int flow_find_head_matching_sequence (basic_block, basic_block, 809 rtx *, rtx *, int); 810 811 extern bool delete_unreachable_blocks (void); 812 813 extern bool mark_dfs_back_edges (void); 814 extern void set_edge_can_fallthru_flag (void); 815 extern void update_br_prob_note (basic_block); 816 extern void fixup_abnormal_edges (void); 817 extern bool inside_basic_block_p (const_rtx); 818 extern bool control_flow_insn_p (const_rtx); 819 extern rtx get_last_bb_insn (basic_block); 820 821 /* In bb-reorder.c */ 822 extern void reorder_basic_blocks (void); 823 824 /* In dominance.c */ 825 826 enum cdi_direction 827 { 828 CDI_DOMINATORS = 1, 829 CDI_POST_DOMINATORS = 2 830 }; 831 832 extern enum dom_state dom_info_state (enum cdi_direction); 833 extern void set_dom_info_availability (enum cdi_direction, enum dom_state); 834 extern bool dom_info_available_p (enum cdi_direction); 835 extern void calculate_dominance_info (enum cdi_direction); 836 extern void free_dominance_info (enum cdi_direction); 837 extern basic_block nearest_common_dominator (enum cdi_direction, 838 basic_block, basic_block); 839 extern basic_block nearest_common_dominator_for_set (enum cdi_direction, 840 bitmap); 841 extern void set_immediate_dominator (enum cdi_direction, basic_block, 842 basic_block); 843 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block); 844 extern bool dominated_by_p (enum cdi_direction, const_basic_block, const_basic_block); 845 extern VEC (basic_block, heap) *get_dominated_by (enum cdi_direction, basic_block); 846 extern VEC (basic_block, heap) *get_dominated_by_region (enum cdi_direction, 847 basic_block *, 848 unsigned); 849 extern VEC (basic_block, heap) *get_dominated_to_depth (enum cdi_direction, 850 basic_block, int); 851 extern VEC (basic_block, heap) *get_all_dominated_blocks (enum cdi_direction, 852 basic_block); 853 extern void add_to_dominance_info (enum cdi_direction, basic_block); 854 extern void delete_from_dominance_info (enum cdi_direction, basic_block); 855 basic_block recompute_dominator (enum cdi_direction, basic_block); 856 extern void redirect_immediate_dominators (enum cdi_direction, basic_block, 857 basic_block); 858 extern void iterate_fix_dominators (enum cdi_direction, 859 VEC (basic_block, heap) *, bool); 860 extern void verify_dominators (enum cdi_direction); 861 extern basic_block first_dom_son (enum cdi_direction, basic_block); 862 extern basic_block next_dom_son (enum cdi_direction, basic_block); 863 unsigned bb_dom_dfs_in (enum cdi_direction, basic_block); 864 unsigned bb_dom_dfs_out (enum cdi_direction, basic_block); 865 866 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool); 867 extern void break_superblocks (void); 868 extern void relink_block_chain (bool); 869 extern void check_bb_profile (basic_block, FILE *); 870 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge); 871 extern void init_rtl_bb_info (basic_block); 872 873 extern void initialize_original_copy_tables (void); 874 extern void free_original_copy_tables (void); 875 extern void set_bb_original (basic_block, basic_block); 876 extern basic_block get_bb_original (basic_block); 877 extern void set_bb_copy (basic_block, basic_block); 878 extern basic_block get_bb_copy (basic_block); 879 void set_loop_copy (struct loop *, struct loop *); 880 struct loop *get_loop_copy (struct loop *); 881 882 #include "cfghooks.h" 883 884 /* Return true when one of the predecessor edges of BB is marked with EDGE_EH. */ 885 static inline bool 886 bb_has_eh_pred (basic_block bb) 887 { 888 edge e; 889 edge_iterator ei; 890 891 FOR_EACH_EDGE (e, ei, bb->preds) 892 { 893 if (e->flags & EDGE_EH) 894 return true; 895 } 896 return false; 897 } 898 899 /* Return true when one of the predecessor edges of BB is marked with EDGE_ABNORMAL. */ 900 static inline bool 901 bb_has_abnormal_pred (basic_block bb) 902 { 903 edge e; 904 edge_iterator ei; 905 906 FOR_EACH_EDGE (e, ei, bb->preds) 907 { 908 if (e->flags & EDGE_ABNORMAL) 909 return true; 910 } 911 return false; 912 } 913 914 /* Return the fallthru edge in EDGES if it exists, NULL otherwise. */ 915 static inline edge 916 find_fallthru_edge (VEC(edge,gc) *edges) 917 { 918 edge e; 919 edge_iterator ei; 920 921 FOR_EACH_EDGE (e, ei, edges) 922 if (e->flags & EDGE_FALLTHRU) 923 break; 924 925 return e; 926 } 927 928 /* In cfgloopmanip.c. */ 929 extern edge mfb_kj_edge; 930 extern bool mfb_keep_just (edge); 931 932 /* In cfgexpand.c. */ 933 extern void rtl_profile_for_bb (basic_block); 934 extern void rtl_profile_for_edge (edge); 935 extern void default_rtl_profile (void); 936 937 #endif /* GCC_BASIC_BLOCK_H */ 938
