gcc/basic-block.h

   1 /* Define control and data flow tables, and regsets.
   2    Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
   3    2005, 2006, 2007, 2008, 2009 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 "bitmap.h"
  25 #include "sbitmap.h"
  26 #include "varray.h"
  27 #include "partition.h"
  28 #include "hard-reg-set.h"
  29 #include "predict.h"
  30 #include "vec.h"
  31 #include "function.h"
  32
  33 /* Head of register set linked list.  */
  34 typedef bitmap_head regset_head;
  35
  36 /* A pointer to a regset_head.  */
  37 typedef bitmap regset;
  38
  39 /* Allocate a register set with oballoc.  */
  40 #define ALLOC_REG_SET(OBSTACK) BITMAP_ALLOC (OBSTACK)
  41
  42 /* Do any cleanup needed on a regset when it is no longer used.  */
  43 #define FREE_REG_SET(REGSET) BITMAP_FREE (REGSET)
  44
  45 /* Initialize a new regset.  */
  46 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, &reg_obstack)
  47
  48 /* Clear a register set by freeing up the linked list.  */
  49 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  50
  51 /* Copy a register set to another register set.  */
  52 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  53
  54 /* Compare two register sets.  */
  55 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  56
  57 /* `and' a register set with a second register set.  */
  58 #define AND_REG_SET(TO, FROM) bitmap_and_into (TO, FROM)
  59
  60 /* `and' the complement of a register set with a register set.  */
  61 #define AND_COMPL_REG_SET(TO, FROM) bitmap_and_compl_into (TO, FROM)
  62
  63 /* Inclusive or a register set with a second register set.  */
  64 #define IOR_REG_SET(TO, FROM) bitmap_ior_into (TO, FROM)
  65
  66 /* Exclusive or a register set with a second register set.  */
  67 #define XOR_REG_SET(TO, FROM) bitmap_xor_into (TO, FROM)
  68
  69 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  70 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  71   bitmap_ior_and_compl_into (TO, FROM1, FROM2)
  72
  73 /* Clear a single register in a register set.  */
  74 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  75
  76 /* Set a single register in a register set.  */
  77 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  78
  79 /* Return true if a register is set in a register set.  */
  80 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  81
  82 /* Copy the hard registers in a register set to the hard register set.  */
  83 extern void reg_set_to_hard_reg_set (HARD_REG_SET *, const_bitmap);
  84 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  85 do {                                                                    \
  86   CLEAR_HARD_REG_SET (TO);                                              \
  87   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  88 } while (0)
  89
  90 typedef bitmap_iterator reg_set_iterator;
  91
  92 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  93    register number and executing CODE for all registers that are set.  */
  94 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, RSI)     \
  95   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, RSI)
  96
  97 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  98    REGNUM to the register number and executing CODE for all registers that are
  99    set in the first regset and not set in the second.  */
 100 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
 101   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI)
 102
 103 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
 104    REGNUM to the register number and executing CODE for all registers that are
 105    set in both regsets.  */
 106 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
 107   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI) \
 108
 109 /* Same information as REGS_INVALIDATED_BY_CALL but in regset form to be used
 110    in dataflow more conveniently.  */
 111
 112 extern regset regs_invalidated_by_call_regset;
 113
 114 /* Type we use to hold basic block counters.  Should be at least
 115    64bit.  Although a counter cannot be negative, we use a signed
 116    type, because erroneous negative counts can be generated when the
 117    flow graph is manipulated by various optimizations.  A signed type
 118    makes those easy to detect.  */
 119 typedef HOST_WIDEST_INT gcov_type;
 120
 121 /* Control flow edge information.  */
 122 struct GTY(()) edge_def {
 123   /* The two blocks at the ends of the edge.  */
 124   struct basic_block_def *src;
 125   struct basic_block_def *dest;
 126
 127   /* Instructions queued on the edge.  */
 128   union edge_def_insns {
 129     gimple_seq GTY ((tag ("true"))) g;
 130     rtx GTY ((tag ("false"))) r;
 131   } GTY ((desc ("current_ir_type () == IR_GIMPLE"))) insns;
 132
 133   /* Auxiliary info specific to a pass.  */
 134   PTR GTY ((skip (""))) aux;
 135
 136   /* Location of any goto implicit in the edge and associated BLOCK.  */
 137   tree goto_block;
 138   location_t goto_locus;
 139
 140   /* The index number corresponding to this edge in the edge vector
 141      dest->preds.  */
 142   unsigned int dest_idx;
 143
 144   int flags;                    /* see EDGE_* below  */
 145   int probability;              /* biased by REG_BR_PROB_BASE */
 146   gcov_type count;              /* Expected number of executions calculated
 147                                    in profile.c  */
 148 };
 149
 150 DEF_VEC_P(edge);
 151 DEF_VEC_ALLOC_P(edge,gc);
 152 DEF_VEC_ALLOC_P(edge,heap);
 153
 154 #define EDGE_FALLTHRU           1       /* 'Straight line' flow */
 155 #define EDGE_ABNORMAL           2       /* Strange flow, like computed
 156                                            label, or eh */
 157 #define EDGE_ABNORMAL_CALL      4       /* Call with abnormal exit
 158                                            like an exception, or sibcall */
 159 #define EDGE_EH                 8       /* Exception throw */
 160 #define EDGE_FAKE               16      /* Not a real edge (profile.c) */
 161 #define EDGE_DFS_BACK           32      /* A backwards edge */
 162 #define EDGE_CAN_FALLTHRU       64      /* Candidate for straight line
 163                                            flow.  */
 164 #define EDGE_IRREDUCIBLE_LOOP   128     /* Part of irreducible loop.  */
 165 #define EDGE_SIBCALL            256     /* Edge from sibcall to exit.  */
 166 #define EDGE_LOOP_EXIT          512     /* Exit of a loop.  */
 167 #define EDGE_TRUE_VALUE         1024    /* Edge taken when controlling
 168                                            predicate is nonzero.  */
 169 #define EDGE_FALSE_VALUE        2048    /* Edge taken when controlling
 170                                            predicate is zero.  */
 171 #define EDGE_EXECUTABLE         4096    /* Edge is executable.  Only
 172                                            valid during SSA-CCP.  */
 173 #define EDGE_CROSSING           8192    /* Edge crosses between hot
 174                                            and cold sections, when we
 175                                            do partitioning.  */
 176 #define EDGE_ALL_FLAGS         16383
 177
 178 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 179
 180 /* Counter summary from the last set of coverage counts read by
 181    profile.c.  */
 182 extern const struct gcov_ctr_summary *profile_info;
 183
 184 /* Declared in cfgloop.h.  */
 185 struct loop;
 186
 187 /* Declared in tree-flow.h.  */
 188 struct edge_prediction;
 189 struct rtl_bb_info;
 190
 191 /* A basic block is a sequence of instructions with only entry and
 192    only one exit.  If any one of the instructions are executed, they
 193    will all be executed, and in sequence from first to last.
 194
 195    There may be COND_EXEC instructions in the basic block.  The
 196    COND_EXEC *instructions* will be executed -- but if the condition
 197    is false the conditionally executed *expressions* will of course
 198    not be executed.  We don't consider the conditionally executed
 199    expression (which might have side-effects) to be in a separate
 200    basic block because the program counter will always be at the same
 201    location after the COND_EXEC instruction, regardless of whether the
 202    condition is true or not.
 203
 204    Basic blocks need not start with a label nor end with a jump insn.
 205    For example, a previous basic block may just "conditionally fall"
 206    into the succeeding basic block, and the last basic block need not
 207    end with a jump insn.  Block 0 is a descendant of the entry block.
 208
 209    A basic block beginning with two labels cannot have notes between
 210    the labels.
 211
 212    Data for jump tables are stored in jump_insns that occur in no
 213    basic block even though these insns can follow or precede insns in
 214    basic blocks.  */
 215
 216 /* Basic block information indexed by block number.  */
 217 struct GTY((chain_next ("%h.next_bb"), chain_prev ("%h.prev_bb"))) basic_block_def {
 218   /* The edges into and out of the block.  */
 219   VEC(edge,gc) *preds;
 220   VEC(edge,gc) *succs;
 221
 222   /* Auxiliary info specific to a pass.  */
 223   PTR GTY ((skip (""))) aux;
 224
 225   /* Innermost loop containing the block.  */
 226   struct loop *loop_father;
 227
 228   /* The dominance and postdominance information node.  */
 229   struct et_node * GTY ((skip (""))) dom[2];
 230
 231   /* Previous and next blocks in the chain.  */
 232   struct basic_block_def *prev_bb;
 233   struct basic_block_def *next_bb;
 234
 235   union basic_block_il_dependent {
 236       struct gimple_bb_info * GTY ((tag ("0"))) gimple;
 237       struct rtl_bb_info * GTY ((tag ("1"))) rtl;
 238     } GTY ((desc ("((%1.flags & BB_RTL) != 0)"))) il;
 239
 240   /* Expected number of executions: calculated in profile.c.  */
 241   gcov_type count;
 242
 243   /* The index of this block.  */
 244   int index;
 245
 246   /* The loop depth of this block.  */
 247   int loop_depth;
 248
 249   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 250   int frequency;
 251
 252   /* The discriminator for this block.  */
 253   int discriminator;
 254
 255   /* Various flags.  See BB_* below.  */
 256   int flags;
 257 };
 258
 259 struct GTY(()) rtl_bb_info {
 260   /* The first and last insns of the block.  */
 261   rtx head_;
 262   rtx end_;
 263
 264   /* In CFGlayout mode points to insn notes/jumptables to be placed just before
 265      and after the block.   */
 266   rtx header;
 267   rtx footer;
 268
 269   /* This field is used by the bb-reorder and tracer passes.  */
 270   int visited;
 271 };
 272
 273 struct GTY(()) gimple_bb_info {
 274   /* Sequence of statements in this block.  */
 275   gimple_seq seq;
 276
 277   /* PHI nodes for this block.  */
 278   gimple_seq phi_nodes;
 279 };
 280
 281 DEF_VEC_P(basic_block);
 282 DEF_VEC_ALLOC_P(basic_block,gc);
 283 DEF_VEC_ALLOC_P(basic_block,heap);
 284
 285 #define BB_FREQ_MAX 10000
 286
 287 /* Masks for basic_block.flags.
 288
 289    BB_HOT_PARTITION and BB_COLD_PARTITION should be preserved throughout
 290    the compilation, so they are never cleared.
 291
 292    All other flags may be cleared by clear_bb_flags().  It is generally
 293    a bad idea to rely on any flags being up-to-date.  */
 294
 295 enum bb_flags
 296 {
 297   /* Only set on blocks that have just been created by create_bb.  */
 298   BB_NEW = 1 << 0,
 299
 300   /* Set by find_unreachable_blocks.  Do not rely on this being set in any
 301      pass.  */
 302   BB_REACHABLE = 1 << 1,
 303
 304   /* Set for blocks in an irreducible loop by loop analysis.  */
 305   BB_IRREDUCIBLE_LOOP = 1 << 2,
 306
 307   /* Set on blocks that may actually not be single-entry single-exit block.  */
 308   BB_SUPERBLOCK = 1 << 3,
 309
 310   /* Set on basic blocks that the scheduler should not touch.  This is used
 311      by SMS to prevent other schedulers from messing with the loop schedule.  */
 312   BB_DISABLE_SCHEDULE = 1 << 4,
 313
 314   /* Set on blocks that should be put in a hot section.  */
 315   BB_HOT_PARTITION = 1 << 5,
 316
 317   /* Set on blocks that should be put in a cold section.  */
 318   BB_COLD_PARTITION = 1 << 6,
 319
 320   /* Set on block that was duplicated.  */
 321   BB_DUPLICATED = 1 << 7,
 322
 323   /* Set if the label at the top of this block is the target of a non-local goto.  */
 324   BB_NON_LOCAL_GOTO_TARGET = 1 << 8,
 325
 326   /* Set on blocks that are in RTL format.  */
 327   BB_RTL = 1 << 9 ,
 328
 329   /* Set on blocks that are forwarder blocks.
 330      Only used in cfgcleanup.c.  */
 331   BB_FORWARDER_BLOCK = 1 << 10,
 332
 333   /* Set on blocks that cannot be threaded through.
 334      Only used in cfgcleanup.c.  */
 335   BB_NONTHREADABLE_BLOCK = 1 << 11
 336 };
 337
 338 /* Dummy flag for convenience in the hot/cold partitioning code.  */
 339 #define BB_UNPARTITIONED        0
 340
 341 /* Partitions, to be used when partitioning hot and cold basic blocks into
 342    separate sections.  */
 343 #define BB_PARTITION(bb) ((bb)->flags & (BB_HOT_PARTITION|BB_COLD_PARTITION))
 344 #define BB_SET_PARTITION(bb, part) do {                                 \
 345   basic_block bb_ = (bb);                                               \
 346   bb_->flags = ((bb_->flags & ~(BB_HOT_PARTITION|BB_COLD_PARTITION))    \
 347                 | (part));                                              \
 348 } while (0)
 349
 350 #define BB_COPY_PARTITION(dstbb, srcbb) \
 351   BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb))
 352
 353 /* State of dominance information.  */
 354
 355 enum dom_state
 356 {
 357   DOM_NONE,             /* Not computed at all.  */
 358   DOM_NO_FAST_QUERY,    /* The data is OK, but the fast query data are not usable.  */
 359   DOM_OK                /* Everything is ok.  */
 360 };
 361
 362 /* What sort of profiling information we have.  */
 363 enum profile_status_d
 364 {
 365   PROFILE_ABSENT,
 366   PROFILE_GUESSED,
 367   PROFILE_READ
 368 };
 369
 370 /* A structure to group all the per-function control flow graph data.
 371    The x_* prefixing is necessary because otherwise references to the
 372    fields of this struct are interpreted as the defines for backward
 373    source compatibility following the definition of this struct.  */
 374 struct GTY(()) control_flow_graph {
 375   /* Block pointers for the exit and entry of a function.
 376      These are always the head and tail of the basic block list.  */
 377   basic_block x_entry_block_ptr;
 378   basic_block x_exit_block_ptr;
 379
 380   /* Index by basic block number, get basic block struct info.  */
 381   VEC(basic_block,gc) *x_basic_block_info;
 382
 383   /* Number of basic blocks in this flow graph.  */
 384   int x_n_basic_blocks;
 385
 386   /* Number of edges in this flow graph.  */
 387   int x_n_edges;
 388
 389   /* The first free basic block number.  */
 390   int x_last_basic_block;
 391
 392   /* Mapping of labels to their associated blocks.  At present
 393      only used for the gimple CFG.  */
 394   VEC(basic_block,gc) *x_label_to_block_map;
 395
 396   enum profile_status_d x_profile_status;
 397
 398   /* Whether the dominators and the postdominators are available.  */
 399   enum dom_state x_dom_computed[2];
 400
 401   /* Number of basic blocks in the dominance tree.  */
 402   unsigned x_n_bbs_in_dom_tree[2];
 403
 404   /* Maximal number of entities in the single jumptable.  Used to estimate
 405      final flowgraph size.  */
 406   int max_jumptable_ents;
 407
 408   /* UIDs for LABEL_DECLs.  */
 409   int last_label_uid;
 410 };
 411
 412 /* Defines for accessing the fields of the CFG structure for function FN.  */
 413 #define ENTRY_BLOCK_PTR_FOR_FUNCTION(FN)     ((FN)->cfg->x_entry_block_ptr)
 414 #define EXIT_BLOCK_PTR_FOR_FUNCTION(FN)      ((FN)->cfg->x_exit_block_ptr)
 415 #define basic_block_info_for_function(FN)    ((FN)->cfg->x_basic_block_info)
 416 #define n_basic_blocks_for_function(FN)      ((FN)->cfg->x_n_basic_blocks)
 417 #define n_edges_for_function(FN)             ((FN)->cfg->x_n_edges)
 418 #define last_basic_block_for_function(FN)    ((FN)->cfg->x_last_basic_block)
 419 #define label_to_block_map_for_function(FN)  ((FN)->cfg->x_label_to_block_map)
 420 #define profile_status_for_function(FN)      ((FN)->cfg->x_profile_status)
 421
 422 #define BASIC_BLOCK_FOR_FUNCTION(FN,N) \
 423   (VEC_index (basic_block, basic_block_info_for_function(FN), (N)))
 424 #define SET_BASIC_BLOCK_FOR_FUNCTION(FN,N,BB) \
 425   (VEC_replace (basic_block, basic_block_info_for_function(FN), (N), (BB)))
 426
 427 /* Defines for textual backward source compatibility.  */
 428 #define ENTRY_BLOCK_PTR         (cfun->cfg->x_entry_block_ptr)
 429 #define EXIT_BLOCK_PTR          (cfun->cfg->x_exit_block_ptr)
 430 #define basic_block_info        (cfun->cfg->x_basic_block_info)
 431 #define n_basic_blocks          (cfun->cfg->x_n_basic_blocks)
 432 #define n_edges                 (cfun->cfg->x_n_edges)
 433 #define last_basic_block        (cfun->cfg->x_last_basic_block)
 434 #define label_to_block_map      (cfun->cfg->x_label_to_block_map)
 435 #define profile_status          (cfun->cfg->x_profile_status)
 436
 437 #define BASIC_BLOCK(N)          (VEC_index (basic_block, basic_block_info, (N)))
 438 #define SET_BASIC_BLOCK(N,BB)   (VEC_replace (basic_block, basic_block_info, (N), (BB)))
 439
 440 /* For iterating over basic blocks.  */
 441 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 442   for (BB = FROM; BB != TO; BB = BB->DIR)
 443
 444 #define FOR_EACH_BB_FN(BB, FN) \
 445   FOR_BB_BETWEEN (BB, (FN)->cfg->x_entry_block_ptr->next_bb, (FN)->cfg->x_exit_block_ptr, next_bb)
 446
 447 #define FOR_EACH_BB(BB) FOR_EACH_BB_FN (BB, cfun)
 448
 449 #define FOR_EACH_BB_REVERSE_FN(BB, FN) \
 450   FOR_BB_BETWEEN (BB, (FN)->cfg->x_exit_block_ptr->prev_bb, (FN)->cfg->x_entry_block_ptr, prev_bb)
 451
 452 #define FOR_EACH_BB_REVERSE(BB) FOR_EACH_BB_REVERSE_FN(BB, cfun)
 453
 454 /* For iterating over insns in basic block.  */
 455 #define FOR_BB_INSNS(BB, INSN)                  \
 456   for ((INSN) = BB_HEAD (BB);                   \
 457        (INSN) && (INSN) != NEXT_INSN (BB_END (BB));     \
 458        (INSN) = NEXT_INSN (INSN))
 459
 460 /* For iterating over insns in basic block when we might remove the
 461    current insn.  */
 462 #define FOR_BB_INSNS_SAFE(BB, INSN, CURR)                       \
 463   for ((INSN) = BB_HEAD (BB), (CURR) = (INSN) ? NEXT_INSN ((INSN)): NULL;       \
 464        (INSN) && (INSN) != NEXT_INSN (BB_END (BB));     \
 465        (INSN) = (CURR), (CURR) = (INSN) ? NEXT_INSN ((INSN)) : NULL)
 466
 467 #define FOR_BB_INSNS_REVERSE(BB, INSN)          \
 468   for ((INSN) = BB_END (BB);                    \
 469        (INSN) && (INSN) != PREV_INSN (BB_HEAD (BB));    \
 470        (INSN) = PREV_INSN (INSN))
 471
 472 #define FOR_BB_INSNS_REVERSE_SAFE(BB, INSN, CURR)       \
 473   for ((INSN) = BB_END (BB),(CURR) = (INSN) ? PREV_INSN ((INSN)) : NULL;        \
 474        (INSN) && (INSN) != PREV_INSN (BB_HEAD (BB));    \
 475        (INSN) = (CURR), (CURR) = (INSN) ? PREV_INSN ((INSN)) : NULL)
 476
 477 /* Cycles through _all_ basic blocks, even the fake ones (entry and
 478    exit block).  */
 479
 480 #define FOR_ALL_BB(BB) \
 481   for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
 482
 483 #define FOR_ALL_BB_FN(BB, FN) \
 484   for (BB = ENTRY_BLOCK_PTR_FOR_FUNCTION (FN); BB; BB = BB->next_bb)
 485
 486 extern bitmap_obstack reg_obstack;
 487
 488 \f
 489 /* Stuff for recording basic block info.  */
 490
 491 #define BB_HEAD(B)      (B)->il.rtl->head_
 492 #define BB_END(B)       (B)->il.rtl->end_
 493
 494 /* Special block numbers [markers] for entry and exit.
 495    Neither of them is supposed to hold actual statements.  */
 496 #define ENTRY_BLOCK (0)
 497 #define EXIT_BLOCK (1)
 498
 499 /* The two blocks that are always in the cfg.  */
 500 #define NUM_FIXED_BLOCKS (2)
 501
 502
 503 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 504 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 505
 506 extern void compute_bb_for_insn (void);
 507 extern unsigned int free_bb_for_insn (void);
 508 extern void update_bb_for_insn (basic_block);
 509
 510 extern void insert_insn_on_edge (rtx, edge);
 511 basic_block split_edge_and_insert (edge, rtx);
 512
 513 extern void commit_one_edge_insertion (edge e);
 514 extern void commit_edge_insertions (void);
 515
 516 extern void remove_fake_edges (void);
 517 extern void remove_fake_exit_edges (void);
 518 extern void add_noreturn_fake_exit_edges (void);
 519 extern void connect_infinite_loops_to_exit (void);
 520 extern edge unchecked_make_edge (basic_block, basic_block, int);
 521 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int);
 522 extern edge make_edge (basic_block, basic_block, int);
 523 extern edge make_single_succ_edge (basic_block, basic_block, int);
 524 extern void remove_edge_raw (edge);
 525 extern void redirect_edge_succ (edge, basic_block);
 526 extern edge redirect_edge_succ_nodup (edge, basic_block);
 527 extern void redirect_edge_pred (edge, basic_block);
 528 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
 529 extern void clear_bb_flags (void);
 530 extern int post_order_compute (int *, bool, bool);
 531 extern int inverted_post_order_compute (int *);
 532 extern int pre_and_rev_post_order_compute (int *, int *, bool);
 533 extern int dfs_enumerate_from (basic_block, int,
 534                                bool (*)(const_basic_block, const void *),
 535                                basic_block *, int, const void *);
 536 extern void compute_dominance_frontiers (bitmap *);
 537 extern bitmap compute_idf (bitmap, bitmap *);
 538 extern void dump_bb_info (basic_block, bool, bool, int, const char *, FILE *);
 539 extern void dump_edge_info (FILE *, edge, int);
 540 extern void brief_dump_cfg (FILE *);
 541 extern void clear_edges (void);
 542 extern void scale_bbs_frequencies_int (basic_block *, int, int, int);
 543 extern void scale_bbs_frequencies_gcov_type (basic_block *, int, gcov_type,
 544                                              gcov_type);
 545
 546 /* Structure to group all of the information to process IF-THEN and
 547    IF-THEN-ELSE blocks for the conditional execution support.  This
 548    needs to be in a public file in case the IFCVT macros call
 549    functions passing the ce_if_block data structure.  */
 550
 551 typedef struct ce_if_block
 552 {
 553   basic_block test_bb;                  /* First test block.  */
 554   basic_block then_bb;                  /* THEN block.  */
 555   basic_block else_bb;                  /* ELSE block or NULL.  */
 556   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 557   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 558   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 559   int num_and_and_blocks;               /* # of && blocks.  */
 560   int num_or_or_blocks;                 /* # of || blocks.  */
 561   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 562   int and_and_p;                        /* Complex test is &&.  */
 563   int num_then_insns;                   /* # of insns in THEN block.  */
 564   int num_else_insns;                   /* # of insns in ELSE block.  */
 565   int pass;                             /* Pass number.  */
 566
 567 #ifdef IFCVT_EXTRA_FIELDS
 568   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 569 #endif
 570
 571 } ce_if_block_t;
 572
 573 /* This structure maintains an edge list vector.  */
 574 struct edge_list
 575 {
 576   int num_blocks;
 577   int num_edges;
 578   edge *index_to_edge;
 579 };
 580
 581 /* The base value for branch probability notes and edge probabilities.  */
 582 #define REG_BR_PROB_BASE  10000
 583
 584 /* This is the value which indicates no edge is present.  */
 585 #define EDGE_INDEX_NO_EDGE      -1
 586
 587 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 588    if there is no edge between the 2 basic blocks.  */
 589 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 590
 591 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 592    block which is either the pred or succ end of the indexed edge.  */
 593 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 594 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 595
 596 /* INDEX_EDGE returns a pointer to the edge.  */
 597 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 598
 599 /* Number of edges in the compressed edge list.  */
 600 #define NUM_EDGES(el)                   ((el)->num_edges)
 601
 602 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 603 #define FALLTHRU_EDGE(bb)               (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 604                                          ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
 605
 606 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 607 #define BRANCH_EDGE(bb)                 (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 608                                          ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
 609
 610 /* Return expected execution frequency of the edge E.  */
 611 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 612                                           * (e)->probability \
 613                                           + REG_BR_PROB_BASE / 2) \
 614                                          / REG_BR_PROB_BASE)
 615
 616 /* Return nonzero if edge is critical.  */
 617 #define EDGE_CRITICAL_P(e)              (EDGE_COUNT ((e)->src->succs) >= 2 \
 618                                          && EDGE_COUNT ((e)->dest->preds) >= 2)
 619
 620 #define EDGE_COUNT(ev)                  VEC_length (edge, (ev))
 621 #define EDGE_I(ev,i)                    VEC_index  (edge, (ev), (i))
 622 #define EDGE_PRED(bb,i)                 VEC_index  (edge, (bb)->preds, (i))
 623 #define EDGE_SUCC(bb,i)                 VEC_index  (edge, (bb)->succs, (i))
 624
 625 /* Returns true if BB has precisely one successor.  */
 626
 627 static inline bool
 628 single_succ_p (const_basic_block bb)
 629 {
 630   return EDGE_COUNT (bb->succs) == 1;
 631 }
 632
 633 /* Returns true if BB has precisely one predecessor.  */
 634
 635 static inline bool
 636 single_pred_p (const_basic_block bb)
 637 {
 638   return EDGE_COUNT (bb->preds) == 1;
 639 }
 640
 641 /* Returns the single successor edge of basic block BB.  Aborts if
 642    BB does not have exactly one successor.  */
 643
 644 static inline edge
 645 single_succ_edge (const_basic_block bb)
 646 {
 647   gcc_assert (single_succ_p (bb));
 648   return EDGE_SUCC (bb, 0);
 649 }
 650
 651 /* Returns the single predecessor edge of basic block BB.  Aborts
 652    if BB does not have exactly one predecessor.  */
 653
 654 static inline edge
 655 single_pred_edge (const_basic_block bb)
 656 {
 657   gcc_assert (single_pred_p (bb));
 658   return EDGE_PRED (bb, 0);
 659 }
 660
 661 /* Returns the single successor block of basic block BB.  Aborts
 662    if BB does not have exactly one successor.  */
 663
 664 static inline basic_block
 665 single_succ (const_basic_block bb)
 666 {
 667   return single_succ_edge (bb)->dest;
 668 }
 669
 670 /* Returns the single predecessor block of basic block BB.  Aborts
 671    if BB does not have exactly one predecessor.*/
 672
 673 static inline basic_block
 674 single_pred (const_basic_block bb)
 675 {
 676   return single_pred_edge (bb)->src;
 677 }
 678
 679 /* Iterator object for edges.  */
 680
 681 typedef struct {
 682   unsigned index;
 683   VEC(edge,gc) **container;
 684 } edge_iterator;
 685
 686 static inline VEC(edge,gc) *
 687 ei_container (edge_iterator i)
 688 {
 689   gcc_assert (i.container);
 690   return *i.container;
 691 }
 692
 693 #define ei_start(iter) ei_start_1 (&(iter))
 694 #define ei_last(iter) ei_last_1 (&(iter))
 695
 696 /* Return an iterator pointing to the start of an edge vector.  */
 697 static inline edge_iterator
 698 ei_start_1 (VEC(edge,gc) **ev)
 699 {
 700   edge_iterator i;
 701
 702   i.index = 0;
 703   i.container = ev;
 704
 705   return i;
 706 }
 707
 708 /* Return an iterator pointing to the last element of an edge
 709    vector.  */
 710 static inline edge_iterator
 711 ei_last_1 (VEC(edge,gc) **ev)
 712 {
 713   edge_iterator i;
 714
 715   i.index = EDGE_COUNT (*ev) - 1;
 716   i.container = ev;
 717
 718   return i;
 719 }
 720
 721 /* Is the iterator `i' at the end of the sequence?  */
 722 static inline bool
 723 ei_end_p (edge_iterator i)
 724 {
 725   return (i.index == EDGE_COUNT (ei_container (i)));
 726 }
 727
 728 /* Is the iterator `i' at one position before the end of the
 729    sequence?  */
 730 static inline bool
 731 ei_one_before_end_p (edge_iterator i)
 732 {
 733   return (i.index + 1 == EDGE_COUNT (ei_container (i)));
 734 }
 735
 736 /* Advance the iterator to the next element.  */
 737 static inline void
 738 ei_next (edge_iterator *i)
 739 {
 740   gcc_assert (i->index < EDGE_COUNT (ei_container (*i)));
 741   i->index++;
 742 }
 743
 744 /* Move the iterator to the previous element.  */
 745 static inline void
 746 ei_prev (edge_iterator *i)
 747 {
 748   gcc_assert (i->index > 0);
 749   i->index--;
 750 }
 751
 752 /* Return the edge pointed to by the iterator `i'.  */
 753 static inline edge
 754 ei_edge (edge_iterator i)
 755 {
 756   return EDGE_I (ei_container (i), i.index);
 757 }
 758
 759 /* Return an edge pointed to by the iterator.  Do it safely so that
 760    NULL is returned when the iterator is pointing at the end of the
 761    sequence.  */
 762 static inline edge
 763 ei_safe_edge (edge_iterator i)
 764 {
 765   return !ei_end_p (i) ? ei_edge (i) : NULL;
 766 }
 767
 768 /* Return 1 if we should continue to iterate.  Return 0 otherwise.
 769    *Edge P is set to the next edge if we are to continue to iterate
 770    and NULL otherwise.  */
 771
 772 static inline bool
 773 ei_cond (edge_iterator ei, edge *p)
 774 {
 775   if (!ei_end_p (ei))
 776     {
 777       *p = ei_edge (ei);
 778       return 1;
 779     }
 780   else
 781     {
 782       *p = NULL;
 783       return 0;
 784     }
 785 }
 786
 787 /* This macro serves as a convenient way to iterate each edge in a
 788    vector of predecessor or successor edges.  It must not be used when
 789    an element might be removed during the traversal, otherwise
 790    elements will be missed.  Instead, use a for-loop like that shown
 791    in the following pseudo-code:
 792
 793    FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 794      {
 795         IF (e != taken_edge)
 796           remove_edge (e);
 797         ELSE
 798           ei_next (&ei);
 799      }
 800 */
 801
 802 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC)       \
 803   for ((ITER) = ei_start ((EDGE_VEC));          \
 804        ei_cond ((ITER), &(EDGE));               \
 805        ei_next (&(ITER)))
 806
 807 struct edge_list * create_edge_list (void);
 808 void free_edge_list (struct edge_list *);
 809 void print_edge_list (FILE *, struct edge_list *);
 810 void verify_edge_list (FILE *, struct edge_list *);
 811 int find_edge_index (struct edge_list *, basic_block, basic_block);
 812 edge find_edge (basic_block, basic_block);
 813
 814 #define CLEANUP_EXPENSIVE       1       /* Do relatively expensive optimizations
 815                                            except for edge forwarding */
 816 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 817 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 818                                            to care REG_DEAD notes.  */
 819 #define CLEANUP_THREADING       8       /* Do jump threading.  */
 820 #define CLEANUP_NO_INSN_DEL     16      /* Do not try to delete trivially dead
 821                                            insns.  */
 822 #define CLEANUP_CFGLAYOUT       32      /* Do cleanup in cfglayout mode.  */
 823
 824 /* In lcm.c */
 825 extern struct edge_list *pre_edge_lcm (int, sbitmap *, sbitmap *,
 826                                        sbitmap *, sbitmap *, sbitmap **,
 827                                        sbitmap **);
 828 extern struct edge_list *pre_edge_rev_lcm (int, sbitmap *,
 829                                            sbitmap *, sbitmap *,
 830                                            sbitmap *, sbitmap **,
 831                                            sbitmap **);
 832 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
 833
 834 /* In predict.c */
 835 extern bool maybe_hot_bb_p (const_basic_block);
 836 extern bool maybe_hot_edge_p (edge);
 837 extern bool probably_never_executed_bb_p (const_basic_block);
 838 extern bool optimize_bb_for_size_p (const_basic_block);
 839 extern bool optimize_bb_for_speed_p (const_basic_block);
 840 extern bool optimize_edge_for_size_p (edge);
 841 extern bool optimize_edge_for_speed_p (edge);
 842 extern bool optimize_function_for_size_p (struct function *);
 843 extern bool optimize_function_for_speed_p (struct function *);
 844 extern bool optimize_loop_for_size_p (struct loop *);
 845 extern bool optimize_loop_for_speed_p (struct loop *);
 846 extern bool optimize_loop_nest_for_size_p (struct loop *);
 847 extern bool optimize_loop_nest_for_speed_p (struct loop *);
 848 extern bool gimple_predicted_by_p (const_basic_block, enum br_predictor);
 849 extern bool rtl_predicted_by_p (const_basic_block, enum br_predictor);
 850 extern void gimple_predict_edge (edge, enum br_predictor, int);
 851 extern void rtl_predict_edge (edge, enum br_predictor, int);
 852 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
 853 extern void guess_outgoing_edge_probabilities (basic_block);
 854 extern void remove_predictions_associated_with_edge (edge);
 855 extern bool edge_probability_reliable_p (const_edge);
 856 extern bool br_prob_note_reliable_p (const_rtx);
 857 extern bool predictable_edge_p (edge);
 858
 859 /* In cfg.c  */
 860 extern void init_flow (struct function *);
 861 extern void debug_bb (basic_block);
 862 extern basic_block debug_bb_n (int);
 863 extern void dump_regset (regset, FILE *);
 864 extern void debug_regset (regset);
 865 extern void expunge_block (basic_block);
 866 extern void link_block (basic_block, basic_block);
 867 extern void unlink_block (basic_block);
 868 extern void compact_blocks (void);
 869 extern basic_block alloc_block (void);
 870 extern void alloc_aux_for_block (basic_block, int);
 871 extern void alloc_aux_for_blocks (int);
 872 extern void clear_aux_for_blocks (void);
 873 extern void free_aux_for_blocks (void);
 874 extern void alloc_aux_for_edge (edge, int);
 875 extern void alloc_aux_for_edges (int);
 876 extern void clear_aux_for_edges (void);
 877 extern void free_aux_for_edges (void);
 878
 879 /* In cfganal.c  */
 880 extern void find_unreachable_blocks (void);
 881 extern bool forwarder_block_p (const_basic_block);
 882 extern bool can_fallthru (basic_block, basic_block);
 883 extern bool could_fall_through (basic_block, basic_block);
 884 extern void flow_nodes_print (const char *, const_sbitmap, FILE *);
 885 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
 886
 887 /* In cfgrtl.c  */
 888 extern basic_block force_nonfallthru (edge);
 889 extern rtx block_label (basic_block);
 890 extern bool purge_all_dead_edges (void);
 891 extern bool purge_dead_edges (basic_block);
 892
 893 /* In cfgbuild.c.  */
 894 extern void find_many_sub_basic_blocks (sbitmap);
 895 extern void rtl_make_eh_edge (sbitmap, basic_block, rtx);
 896
 897 /* In cfgcleanup.c.  */
 898 extern bool cleanup_cfg (int);
 899 extern bool delete_unreachable_blocks (void);
 900
 901 extern bool mark_dfs_back_edges (void);
 902 extern void set_edge_can_fallthru_flag (void);
 903 extern void update_br_prob_note (basic_block);
 904 extern void fixup_abnormal_edges (void);
 905 extern bool inside_basic_block_p (const_rtx);
 906 extern bool control_flow_insn_p (const_rtx);
 907 extern rtx get_last_bb_insn (basic_block);
 908
 909 /* In bb-reorder.c */
 910 extern void reorder_basic_blocks (void);
 911
 912 /* In dominance.c */
 913
 914 enum cdi_direction
 915 {
 916   CDI_DOMINATORS = 1,
 917   CDI_POST_DOMINATORS = 2
 918 };
 919
 920 extern enum dom_state dom_info_state (enum cdi_direction);
 921 extern void set_dom_info_availability (enum cdi_direction, enum dom_state);
 922 extern bool dom_info_available_p (enum cdi_direction);
 923 extern void calculate_dominance_info (enum cdi_direction);
 924 extern void free_dominance_info (enum cdi_direction);
 925 extern basic_block nearest_common_dominator (enum cdi_direction,
 926                                              basic_block, basic_block);
 927 extern basic_block nearest_common_dominator_for_set (enum cdi_direction,
 928                                                      bitmap);
 929 extern void set_immediate_dominator (enum cdi_direction, basic_block,
 930                                      basic_block);
 931 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
 932 extern bool dominated_by_p (enum cdi_direction, const_basic_block, const_basic_block);
 933 extern VEC (basic_block, heap) *get_dominated_by (enum cdi_direction, basic_block);
 934 extern VEC (basic_block, heap) *get_dominated_by_region (enum cdi_direction,
 935                                                          basic_block *,
 936                                                          unsigned);
 937 extern VEC (basic_block, heap) *get_all_dominated_blocks (enum cdi_direction,
 938                                                           basic_block);
 939 extern void add_to_dominance_info (enum cdi_direction, basic_block);
 940 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
 941 basic_block recompute_dominator (enum cdi_direction, basic_block);
 942 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
 943                                            basic_block);
 944 extern void iterate_fix_dominators (enum cdi_direction,
 945                                     VEC (basic_block, heap) *, bool);
 946 extern void verify_dominators (enum cdi_direction);
 947 extern basic_block first_dom_son (enum cdi_direction, basic_block);
 948 extern basic_block next_dom_son (enum cdi_direction, basic_block);
 949 unsigned bb_dom_dfs_in (enum cdi_direction, basic_block);
 950 unsigned bb_dom_dfs_out (enum cdi_direction, basic_block);
 951
 952 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
 953 extern void break_superblocks (void);
 954 extern void relink_block_chain (bool);
 955 extern void check_bb_profile (basic_block, FILE *);
 956 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
 957 extern void init_rtl_bb_info (basic_block);
 958
 959 extern void initialize_original_copy_tables (void);
 960 extern void free_original_copy_tables (void);
 961 extern void set_bb_original (basic_block, basic_block);
 962 extern basic_block get_bb_original (basic_block);
 963 extern void set_bb_copy (basic_block, basic_block);
 964 extern basic_block get_bb_copy (basic_block);
 965 void set_loop_copy (struct loop *, struct loop *);
 966 struct loop *get_loop_copy (struct loop *);
 967
 968
 969 extern rtx insert_insn_end_bb_new (rtx, basic_block);
 970
 971 #include "cfghooks.h"
 972
 973 /* Return true when one of the predecessor edges of BB is marked with EDGE_EH.  */
 974 static inline bool
 975 bb_has_eh_pred (basic_block bb)
 976 {
 977   edge e;
 978   edge_iterator ei;
 979
 980   FOR_EACH_EDGE (e, ei, bb->preds)
 981     {
 982       if (e->flags & EDGE_EH)
 983         return true;
 984     }
 985   return false;
 986 }
 987
 988 /* Return true when one of the predecessor edges of BB is marked with EDGE_ABNORMAL.  */
 989 static inline bool
 990 bb_has_abnormal_pred (basic_block bb)
 991 {
 992   edge e;
 993   edge_iterator ei;
 994
 995   FOR_EACH_EDGE (e, ei, bb->preds)
 996     {
 997       if (e->flags & EDGE_ABNORMAL)
 998         return true;
 999     }
1000   return false;
1001 }
1002
1003 /* In cfgloopmanip.c.  */
1004 extern edge mfb_kj_edge;
1005 extern bool mfb_keep_just (edge);
1006
1007 /* In cfgexpand.c.  */
1008 extern void rtl_profile_for_bb (basic_block);
1009 extern void rtl_profile_for_edge (edge);
1010 extern void default_rtl_profile (void);
1011
1012 #endif /* GCC_BASIC_BLOCK_H */