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, 2005
   3    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 2, 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 COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #ifndef GCC_BASIC_BLOCK_H
  23 #define GCC_BASIC_BLOCK_H
  24
  25 #include "bitmap.h"
  26 #include "sbitmap.h"
  27 #include "varray.h"
  28 #include "partition.h"
  29 #include "hard-reg-set.h"
  30 #include "predict.h"
  31 #include "vec.h"
  32 #include "errors.h"
  33
  34 /* Head of register set linked list.  */
  35 typedef bitmap_head regset_head;
  36
  37 /* A pointer to a regset_head.  */
  38 typedef bitmap regset;
  39
  40 /* Allocate a register set with oballoc.  */
  41 #define ALLOC_REG_SET(OBSTACK) BITMAP_ALLOC (OBSTACK)
  42
  43 /* Do any cleanup needed on a regset when it is no longer used.  */
  44 #define FREE_REG_SET(REGSET) BITMAP_FREE (REGSET)
  45
  46 /* Initialize a new regset.  */
  47 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, &reg_obstack)
  48
  49 /* Clear a register set by freeing up the linked list.  */
  50 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  51
  52 /* Copy a register set to another register set.  */
  53 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  54
  55 /* Compare two register sets.  */
  56 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  57
  58 /* `and' a register set with a second register set.  */
  59 #define AND_REG_SET(TO, FROM) bitmap_and_into (TO, FROM)
  60
  61 /* `and' the complement of a register set with a register set.  */
  62 #define AND_COMPL_REG_SET(TO, FROM) bitmap_and_compl_into (TO, FROM)
  63
  64 /* Inclusive or a register set with a second register set.  */
  65 #define IOR_REG_SET(TO, FROM) bitmap_ior_into (TO, FROM)
  66
  67 /* Exclusive or a register set with a second register set.  */
  68 #define XOR_REG_SET(TO, FROM) bitmap_xor_into (TO, FROM)
  69
  70 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  71 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  72   bitmap_ior_and_compl_into (TO, FROM1, FROM2)
  73
  74 /* Clear a single register in a register set.  */
  75 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  76
  77 /* Set a single register in a register set.  */
  78 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  79
  80 /* Return true if a register is set in a register set.  */
  81 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  82
  83 /* Copy the hard registers in a register set to the hard register set.  */
  84 extern void reg_set_to_hard_reg_set (HARD_REG_SET *, bitmap);
  85 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  86 do {                                                                    \
  87   CLEAR_HARD_REG_SET (TO);                                              \
  88   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  89 } while (0)
  90
  91 typedef bitmap_iterator reg_set_iterator;
  92
  93 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  94    register number and executing CODE for all registers that are set.  */
  95 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, RSI)     \
  96   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, RSI)
  97
  98 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  99    REGNUM to the register number and executing CODE for all registers that are
 100    set in the first regset and not set in the second.  */
 101 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
 102   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI)
 103
 104 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
 105    REGNUM to the register number and executing CODE for all registers that are
 106    set in both regsets.  */
 107 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
 108   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI) \
 109
 110 /* Type we use to hold basic block counters.  Should be at least
 111    64bit.  Although a counter cannot be negative, we use a signed
 112    type, because erroneous negative counts can be generated when the
 113    flow graph is manipulated by various optimizations.  A signed type
 114    makes those easy to detect.  */
 115 typedef HOST_WIDEST_INT gcov_type;
 116
 117 /* Control flow edge information.  */
 118 struct edge_def GTY(())
 119 {
 120   /* The two blocks at the ends of the edge.  */
 121   struct basic_block_def *src;
 122   struct basic_block_def *dest;
 123
 124   /* Instructions queued on the edge.  */
 125   union edge_def_insns {
 126     rtx GTY ((tag ("0"))) r;
 127     tree GTY ((tag ("1"))) t;
 128   } GTY ((desc ("ir_type ()"))) insns;
 129
 130   /* Auxiliary info specific to a pass.  */
 131   PTR GTY ((skip (""))) aux;
 132
 133   /* Location of any goto implicit in the edge, during tree-ssa.  */
 134   source_locus goto_locus;
 135
 136   int flags;                    /* see EDGE_* below  */
 137   int probability;              /* biased by REG_BR_PROB_BASE */
 138   gcov_type count;              /* Expected number of executions calculated
 139                                    in profile.c  */
 140
 141   /* The index number corresponding to this edge in the edge vector
 142      dest->preds.  */
 143   unsigned int dest_idx;
 144 };
 145
 146 typedef struct edge_def *edge;
 147 DEF_VEC_GC_P(edge);
 148
 149 #define EDGE_FALLTHRU           1       /* 'Straight line' flow */
 150 #define EDGE_ABNORMAL           2       /* Strange flow, like computed
 151                                            label, or eh */
 152 #define EDGE_ABNORMAL_CALL      4       /* Call with abnormal exit
 153                                            like an exception, or sibcall */
 154 #define EDGE_EH                 8       /* Exception throw */
 155 #define EDGE_FAKE               16      /* Not a real edge (profile.c) */
 156 #define EDGE_DFS_BACK           32      /* A backwards edge */
 157 #define EDGE_CAN_FALLTHRU       64      /* Candidate for straight line
 158                                            flow.  */
 159 #define EDGE_IRREDUCIBLE_LOOP   128     /* Part of irreducible loop.  */
 160 #define EDGE_SIBCALL            256     /* Edge from sibcall to exit.  */
 161 #define EDGE_LOOP_EXIT          512     /* Exit of a loop.  */
 162 #define EDGE_TRUE_VALUE         1024    /* Edge taken when controlling
 163                                            predicate is nonzero.  */
 164 #define EDGE_FALSE_VALUE        2048    /* Edge taken when controlling
 165                                            predicate is zero.  */
 166 #define EDGE_EXECUTABLE         4096    /* Edge is executable.  Only
 167                                            valid during SSA-CCP.  */
 168 #define EDGE_CROSSING           8192    /* Edge crosses between hot
 169                                            and cold sections, when we
 170                                            do partitioning.  */
 171 #define EDGE_ALL_FLAGS         16383
 172
 173 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 174
 175 /* Counter summary from the last set of coverage counts read by
 176    profile.c.  */
 177 extern const struct gcov_ctr_summary *profile_info;
 178
 179 /* Declared in cfgloop.h.  */
 180 struct loop;
 181 struct loops;
 182
 183 /* Declared in tree-flow.h.  */
 184 struct bb_ann_d;
 185
 186 /* A basic block is a sequence of instructions with only entry and
 187    only one exit.  If any one of the instructions are executed, they
 188    will all be executed, and in sequence from first to last.
 189
 190    There may be COND_EXEC instructions in the basic block.  The
 191    COND_EXEC *instructions* will be executed -- but if the condition
 192    is false the conditionally executed *expressions* will of course
 193    not be executed.  We don't consider the conditionally executed
 194    expression (which might have side-effects) to be in a separate
 195    basic block because the program counter will always be at the same
 196    location after the COND_EXEC instruction, regardless of whether the
 197    condition is true or not.
 198
 199    Basic blocks need not start with a label nor end with a jump insn.
 200    For example, a previous basic block may just "conditionally fall"
 201    into the succeeding basic block, and the last basic block need not
 202    end with a jump insn.  Block 0 is a descendant of the entry block.
 203
 204    A basic block beginning with two labels cannot have notes between
 205    the labels.
 206
 207    Data for jump tables are stored in jump_insns that occur in no
 208    basic block even though these insns can follow or precede insns in
 209    basic blocks.  */
 210
 211 /* Basic block information indexed by block number.  */
 212 struct basic_block_def GTY((chain_next ("%h.next_bb"), chain_prev ("%h.prev_bb")))
 213 {
 214   /* The first and last insns of the block.  */
 215   rtx head_;
 216   rtx end_;
 217
 218   /* Pointers to the first and last trees of the block.  */
 219   tree stmt_list;
 220
 221   /* The edges into and out of the block.  */
 222   VEC(edge) *preds;
 223   VEC(edge) *succs;
 224
 225   /* The registers that are live on entry to this block.  */
 226   bitmap GTY ((skip (""))) global_live_at_start;
 227
 228   /* The registers that are live on exit from this block.  */
 229   bitmap GTY ((skip (""))) global_live_at_end;
 230
 231   /* Auxiliary info specific to a pass.  */
 232   PTR GTY ((skip (""))) aux;
 233
 234   /* Innermost loop containing the block.  */
 235   struct loop * GTY ((skip (""))) loop_father;
 236
 237   /* The dominance and postdominance information node.  */
 238   struct et_node * GTY ((skip (""))) dom[2];
 239
 240   /* Previous and next blocks in the chain.  */
 241   struct basic_block_def *prev_bb;
 242   struct basic_block_def *next_bb;
 243
 244   /* The data used by basic block copying and reordering functions.  */
 245   struct reorder_block_def * GTY ((skip (""))) rbi;
 246
 247   /* Annotations used at the tree level.  */
 248   struct bb_ann_d *tree_annotations;
 249
 250   /* Expected number of executions: calculated in profile.c.  */
 251   gcov_type count;
 252
 253   /* The index of this block.  */
 254   int index;
 255
 256   /* The loop depth of this block.  */
 257   int loop_depth;
 258
 259   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 260   int frequency;
 261
 262   /* Various flags.  See BB_* below.  */
 263   int flags;
 264 };
 265
 266 typedef struct basic_block_def *basic_block;
 267
 268 /* Structure to hold information about the blocks during reordering and
 269    copying.  */
 270
 271 typedef struct reorder_block_def
 272 {
 273   rtx header;
 274   rtx footer;
 275   basic_block next;
 276   basic_block original;
 277   /* Used by loop copying.  */
 278   basic_block copy;
 279   int duplicated;
 280   int copy_number;
 281
 282   /* These fields are used by bb-reorder pass.  */
 283   int visited;
 284 } *reorder_block_def_p;
 285
 286 #define BB_FREQ_MAX 10000
 287
 288 /* Masks for basic_block.flags.
 289
 290    BB_VISITED should not be used by passes, it is used internally by
 291    dfs_enumerate_from.
 292
 293    BB_HOT_PARTITION and BB_COLD_PARTITION should be preserved throughout
 294    the compilation, so they are never cleared.
 295
 296    All other flags may be cleared by clear_bb_flags().  It is generally
 297    a bad idea to rely on any flags being up-to-date.  */
 298
 299 /* Set if insns in BB have are modified.  Used for updating liveness info.  */
 300 #define BB_DIRTY                1
 301
 302 /* Only set on blocks that have just been created by create_bb.  */
 303 #define BB_NEW                  2
 304
 305 /* Set by find_unreachable_blocks.  Do not rely on this being set in any
 306    pass.  */
 307 #define BB_REACHABLE            4
 308
 309 /* Used by dfs_enumerate_from to keep track of visited basic blocks.  */
 310 #define BB_VISITED              8
 311
 312 /* Set for blocks in an irreducible loop by loop analysis.  */
 313 #define BB_IRREDUCIBLE_LOOP     16
 314
 315 /* Set on blocks that may actually not be single-entry single-exit block.  */
 316 #define BB_SUPERBLOCK           32
 317
 318 /* Set on basic blocks that the scheduler should not touch.  This is used
 319    by SMS to prevent other schedulers from messing with the loop schedule.  */
 320 #define BB_DISABLE_SCHEDULE     64
 321
 322 /* Set on blocks that should be put in a hot section.  */
 323 #define BB_HOT_PARTITION        128
 324
 325 /* Set on blocks that should be put in a cold section.  */
 326 #define BB_COLD_PARTITION       256
 327
 328 /* Dummy flag for convenience in the hot/cold partitioning code.  */
 329 #define BB_UNPARTITIONED        0
 330
 331 /* Partitions, to be used when partitioning hot and cold basic blocks into
 332    separate sections.  */
 333 #define BB_PARTITION(bb) ((bb)->flags & (BB_HOT_PARTITION|BB_COLD_PARTITION))
 334 #define BB_SET_PARTITION(bb, part) do {                                 \
 335   basic_block bb_ = (bb);                                               \
 336   bb_->flags = ((bb_->flags & ~(BB_HOT_PARTITION|BB_COLD_PARTITION))    \
 337                 | (part));                                              \
 338 } while (0)
 339
 340 #define BB_COPY_PARTITION(dstbb, srcbb) \
 341   BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb))
 342
 343 /* Number of basic blocks in the current function.  */
 344
 345 extern int n_basic_blocks;
 346
 347 /* First free basic block number.  */
 348
 349 extern int last_basic_block;
 350
 351 /* Number of edges in the current function.  */
 352
 353 extern int n_edges;
 354
 355 /* Signalize the status of profile information in the CFG.  */
 356 extern enum profile_status
 357 {
 358   PROFILE_ABSENT,
 359   PROFILE_GUESSED,
 360   PROFILE_READ
 361 } profile_status;
 362
 363 /* Index by basic block number, get basic block struct info.  */
 364
 365 extern GTY(()) varray_type basic_block_info;
 366
 367 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 368
 369 /* For iterating over basic blocks.  */
 370 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 371   for (BB = FROM; BB != TO; BB = BB->DIR)
 372
 373 #define FOR_EACH_BB(BB) \
 374   FOR_BB_BETWEEN (BB, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
 375
 376 #define FOR_EACH_BB_REVERSE(BB) \
 377   FOR_BB_BETWEEN (BB, EXIT_BLOCK_PTR->prev_bb, ENTRY_BLOCK_PTR, prev_bb)
 378
 379 /* For iterating over insns in basic block.  */
 380 #define FOR_BB_INSNS(BB, INSN)                  \
 381   for ((INSN) = BB_HEAD (BB);                   \
 382        (INSN) != NEXT_INSN (BB_END (BB));       \
 383        (INSN) = NEXT_INSN (INSN))
 384
 385 #define FOR_BB_INSNS_REVERSE(BB, INSN)          \
 386   for ((INSN) = BB_END (BB);                    \
 387        (INSN) != PREV_INSN (BB_HEAD (BB));      \
 388        (INSN) = PREV_INSN (INSN))
 389
 390 /* Cycles through _all_ basic blocks, even the fake ones (entry and
 391    exit block).  */
 392
 393 #define FOR_ALL_BB(BB) \
 394   for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
 395
 396 /* What registers are live at the setjmp call.  */
 397
 398 extern regset regs_live_at_setjmp;
 399
 400 /* Special labels found during CFG build.  */
 401
 402 extern GTY(()) rtx label_value_list;
 403
 404 extern bitmap_obstack reg_obstack;
 405
 406 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 407    If the value is REG_BLOCK_GLOBAL (-2),
 408    it means (REG n) is used in more than one basic block.
 409    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 410    This information remains valid for the rest of the compilation
 411    of the current function; it is used to control register allocation.  */
 412
 413 #define REG_BLOCK_UNKNOWN -1
 414 #define REG_BLOCK_GLOBAL -2
 415
 416 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 417 \f
 418 /* Stuff for recording basic block info.  */
 419
 420 #define BB_HEAD(B)      (B)->head_
 421 #define BB_END(B)       (B)->end_
 422
 423 /* Special block numbers [markers] for entry and exit.  */
 424 #define ENTRY_BLOCK (-1)
 425 #define EXIT_BLOCK (-2)
 426
 427 /* Special block number not valid for any block.  */
 428 #define INVALID_BLOCK (-3)
 429
 430 /* Similarly, block pointers for the edge list.  */
 431 extern GTY(()) basic_block ENTRY_BLOCK_PTR;
 432 extern GTY(()) basic_block EXIT_BLOCK_PTR;
 433
 434 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 435 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 436
 437 extern void compute_bb_for_insn (void);
 438 extern void free_bb_for_insn (void);
 439 extern void update_bb_for_insn (basic_block);
 440
 441 extern void free_basic_block_vars (void);
 442
 443 extern void insert_insn_on_edge (rtx, edge);
 444 bool safe_insert_insn_on_edge (rtx, edge);
 445
 446 extern void commit_edge_insertions (void);
 447 extern void commit_edge_insertions_watch_calls (void);
 448
 449 extern void remove_fake_edges (void);
 450 extern void remove_fake_exit_edges (void);
 451 extern void add_noreturn_fake_exit_edges (void);
 452 extern void connect_infinite_loops_to_exit (void);
 453 extern edge unchecked_make_edge (basic_block, basic_block, int);
 454 extern edge cached_make_edge (sbitmap *, basic_block, basic_block, int);
 455 extern edge make_edge (basic_block, basic_block, int);
 456 extern edge make_single_succ_edge (basic_block, basic_block, int);
 457 extern void remove_edge (edge);
 458 extern void redirect_edge_succ (edge, basic_block);
 459 extern edge redirect_edge_succ_nodup (edge, basic_block);
 460 extern void redirect_edge_pred (edge, basic_block);
 461 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
 462 extern void clear_bb_flags (void);
 463 extern void flow_reverse_top_sort_order_compute (int *);
 464 extern int flow_depth_first_order_compute (int *, int *);
 465 extern int dfs_enumerate_from (basic_block, int,
 466                                bool (*)(basic_block, void *),
 467                                basic_block *, int, void *);
 468 extern void compute_dominance_frontiers (bitmap *);
 469 extern void dump_edge_info (FILE *, edge, int);
 470 extern void brief_dump_cfg (FILE *);
 471 extern void clear_edges (void);
 472 extern rtx first_insn_after_basic_block_note (basic_block);
 473
 474 /* Structure to group all of the information to process IF-THEN and
 475    IF-THEN-ELSE blocks for the conditional execution support.  This
 476    needs to be in a public file in case the IFCVT macros call
 477    functions passing the ce_if_block data structure.  */
 478
 479 typedef struct ce_if_block
 480 {
 481   basic_block test_bb;                  /* First test block.  */
 482   basic_block then_bb;                  /* THEN block.  */
 483   basic_block else_bb;                  /* ELSE block or NULL.  */
 484   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 485   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 486   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 487   int num_and_and_blocks;               /* # of && blocks.  */
 488   int num_or_or_blocks;                 /* # of || blocks.  */
 489   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 490   int and_and_p;                        /* Complex test is &&.  */
 491   int num_then_insns;                   /* # of insns in THEN block.  */
 492   int num_else_insns;                   /* # of insns in ELSE block.  */
 493   int pass;                             /* Pass number.  */
 494
 495 #ifdef IFCVT_EXTRA_FIELDS
 496   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 497 #endif
 498
 499 } ce_if_block_t;
 500
 501 /* This structure maintains an edge list vector.  */
 502 struct edge_list
 503 {
 504   int num_blocks;
 505   int num_edges;
 506   edge *index_to_edge;
 507 };
 508
 509 /* This is the value which indicates no edge is present.  */
 510 #define EDGE_INDEX_NO_EDGE      -1
 511
 512 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 513    if there is no edge between the 2 basic blocks.  */
 514 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 515
 516 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 517    block which is either the pred or succ end of the indexed edge.  */
 518 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 519 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 520
 521 /* INDEX_EDGE returns a pointer to the edge.  */
 522 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 523
 524 /* Number of edges in the compressed edge list.  */
 525 #define NUM_EDGES(el)                   ((el)->num_edges)
 526
 527 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 528 #define FALLTHRU_EDGE(bb)               (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 529                                          ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
 530
 531 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 532 #define BRANCH_EDGE(bb)                 (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 533                                          ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
 534
 535 /* Return expected execution frequency of the edge E.  */
 536 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 537                                           * (e)->probability \
 538                                           + REG_BR_PROB_BASE / 2) \
 539                                          / REG_BR_PROB_BASE)
 540
 541 /* Return nonzero if edge is critical.  */
 542 #define EDGE_CRITICAL_P(e)              (EDGE_COUNT ((e)->src->succs) >= 2 \
 543                                          && EDGE_COUNT ((e)->dest->preds) >= 2)
 544
 545 #define EDGE_COUNT(ev)                  VEC_length (edge, (ev))
 546 #define EDGE_I(ev,i)                    VEC_index  (edge, (ev), (i))
 547 #define EDGE_PRED(bb,i)                 VEC_index  (edge, (bb)->preds, (i))
 548 #define EDGE_SUCC(bb,i)                 VEC_index  (edge, (bb)->succs, (i))
 549
 550 /* Iterator object for edges.  */
 551
 552 typedef struct {
 553   unsigned index;
 554   VEC(edge) **container;
 555 } edge_iterator;
 556
 557 static inline VEC(edge) *
 558 ei_container (edge_iterator i)
 559 {
 560   gcc_assert (i.container);
 561   return *i.container;
 562 }
 563
 564 #define ei_start(iter) ei_start_1 (&(iter))
 565 #define ei_last(iter) ei_last_1 (&(iter))
 566
 567 /* Return an iterator pointing to the start of an edge vector.  */
 568 static inline edge_iterator
 569 ei_start_1 (VEC(edge) **ev)
 570 {
 571   edge_iterator i;
 572
 573   i.index = 0;
 574   i.container = ev;
 575
 576   return i;
 577 }
 578
 579 /* Return an iterator pointing to the last element of an edge
 580    vector.  */
 581 static inline edge_iterator
 582 ei_last_1 (VEC(edge) **ev)
 583 {
 584   edge_iterator i;
 585
 586   i.index = EDGE_COUNT (*ev) - 1;
 587   i.container = ev;
 588
 589   return i;
 590 }
 591
 592 /* Is the iterator `i' at the end of the sequence?  */
 593 static inline bool
 594 ei_end_p (edge_iterator i)
 595 {
 596   return (i.index == EDGE_COUNT (ei_container (i)));
 597 }
 598
 599 /* Is the iterator `i' at one position before the end of the
 600    sequence?  */
 601 static inline bool
 602 ei_one_before_end_p (edge_iterator i)
 603 {
 604   return (i.index + 1 == EDGE_COUNT (ei_container (i)));
 605 }
 606
 607 /* Advance the iterator to the next element.  */
 608 static inline void
 609 ei_next (edge_iterator *i)
 610 {
 611   gcc_assert (i->index < EDGE_COUNT (ei_container (*i)));
 612   i->index++;
 613 }
 614
 615 /* Move the iterator to the previous element.  */
 616 static inline void
 617 ei_prev (edge_iterator *i)
 618 {
 619   gcc_assert (i->index > 0);
 620   i->index--;
 621 }
 622
 623 /* Return the edge pointed to by the iterator `i'.  */
 624 static inline edge
 625 ei_edge (edge_iterator i)
 626 {
 627   return EDGE_I (ei_container (i), i.index);
 628 }
 629
 630 /* Return an edge pointed to by the iterator.  Do it safely so that
 631    NULL is returned when the iterator is pointing at the end of the
 632    sequence.  */
 633 static inline edge
 634 ei_safe_edge (edge_iterator i)
 635 {
 636   return !ei_end_p (i) ? ei_edge (i) : NULL;
 637 }
 638
 639 /* This macro serves as a convenient way to iterate each edge in a
 640    vector of predecessor or successor edges.  It must not be used when
 641    an element might be removed during the traversal, otherwise
 642    elements will be missed.  Instead, use a for-loop like that shown
 643    in the following pseudo-code:
 644
 645    FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 646      {
 647         IF (e != taken_edge)
 648           remove_edge (e);
 649         ELSE
 650           ei_next (&ei);
 651      }
 652 */
 653
 654 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC) \
 655   for ((EDGE) = NULL, (ITER) = ei_start ((EDGE_VEC)); \
 656        ((EDGE) = ei_safe_edge ((ITER))); \
 657        ei_next (&(ITER)))
 658
 659 struct edge_list * create_edge_list (void);
 660 void free_edge_list (struct edge_list *);
 661 void print_edge_list (FILE *, struct edge_list *);
 662 void verify_edge_list (FILE *, struct edge_list *);
 663 int find_edge_index (struct edge_list *, basic_block, basic_block);
 664 edge find_edge (basic_block, basic_block);
 665
 666
 667 enum update_life_extent
 668 {
 669   UPDATE_LIFE_LOCAL = 0,
 670   UPDATE_LIFE_GLOBAL = 1,
 671   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 672 };
 673
 674 /* Flags for life_analysis and update_life_info.  */
 675
 676 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 677 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 678 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 679 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 680 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 681 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 682                                            by dead code removal.  */
 683 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 684 #define PROP_EQUAL_NOTES        128     /* Take into account REG_EQUAL notes.  */
 685 #define PROP_SCAN_DEAD_STORES   256     /* Scan for dead code.  */
 686 #define PROP_ASM_SCAN           512     /* Internal flag used within flow.c
 687                                            to flag analysis of asms.  */
 688 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 689                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 690                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 691                                  | PROP_ALLOW_CFG_CHANGES \
 692                                  | PROP_SCAN_DEAD_STORES)
 693 #define PROP_POSTRELOAD         (PROP_DEATH_NOTES  \
 694                                  | PROP_KILL_DEAD_CODE  \
 695                                  | PROP_SCAN_DEAD_CODE \
 696                                  | PROP_SCAN_DEAD_STORES)
 697
 698 #define CLEANUP_EXPENSIVE       1       /* Do relatively expensive optimizations
 699                                            except for edge forwarding */
 700 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 701 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 702                                            to care REG_DEAD notes.  */
 703 #define CLEANUP_PRE_LOOP        8       /* Take care to preserve syntactic loop
 704                                            notes.  */
 705 #define CLEANUP_UPDATE_LIFE     16      /* Keep life information up to date.  */
 706 #define CLEANUP_THREADING       32      /* Do jump threading.  */
 707 #define CLEANUP_NO_INSN_DEL     64      /* Do not try to delete trivially dead
 708                                            insns.  */
 709 #define CLEANUP_CFGLAYOUT       128     /* Do cleanup in cfglayout mode.  */
 710 #define CLEANUP_LOG_LINKS       256     /* Update log links.  */
 711
 712 extern void life_analysis (FILE *, int);
 713 extern int update_life_info (sbitmap, enum update_life_extent, int);
 714 extern int update_life_info_in_dirty_blocks (enum update_life_extent, int);
 715 extern int count_or_remove_death_notes (sbitmap, int);
 716 extern int propagate_block (basic_block, regset, regset, regset, int);
 717
 718 struct propagate_block_info;
 719 extern rtx propagate_one_insn (struct propagate_block_info *, rtx);
 720 extern struct propagate_block_info *init_propagate_block_info
 721  (basic_block, regset, regset, regset, int);
 722 extern void free_propagate_block_info (struct propagate_block_info *);
 723
 724 /* In lcm.c */
 725 extern struct edge_list *pre_edge_lcm (FILE *, int, sbitmap *, sbitmap *,
 726                                        sbitmap *, sbitmap *, sbitmap **,
 727                                        sbitmap **);
 728 extern struct edge_list *pre_edge_rev_lcm (FILE *, int, sbitmap *,
 729                                            sbitmap *, sbitmap *,
 730                                            sbitmap *, sbitmap **,
 731                                            sbitmap **);
 732 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
 733 extern int optimize_mode_switching (FILE *);
 734
 735 /* In predict.c */
 736 extern void estimate_probability (struct loops *);
 737 extern void expected_value_to_br_prob (void);
 738 extern bool maybe_hot_bb_p (basic_block);
 739 extern bool probably_cold_bb_p (basic_block);
 740 extern bool probably_never_executed_bb_p (basic_block);
 741 extern bool tree_predicted_by_p (basic_block, enum br_predictor);
 742 extern bool rtl_predicted_by_p (basic_block, enum br_predictor);
 743 extern void tree_predict_edge (edge, enum br_predictor, int);
 744 extern void rtl_predict_edge (edge, enum br_predictor, int);
 745 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
 746 extern void guess_outgoing_edge_probabilities (basic_block);
 747
 748 /* In flow.c */
 749 extern void init_flow (void);
 750 extern void debug_bb (basic_block);
 751 extern basic_block debug_bb_n (int);
 752 extern void dump_regset (regset, FILE *);
 753 extern void debug_regset (regset);
 754 extern void allocate_reg_life_data (void);
 755 extern void expunge_block (basic_block);
 756 extern void link_block (basic_block, basic_block);
 757 extern void unlink_block (basic_block);
 758 extern void compact_blocks (void);
 759 extern basic_block alloc_block (void);
 760 extern void find_unreachable_blocks (void);
 761 extern int delete_noop_moves (void);
 762 extern basic_block force_nonfallthru (edge);
 763 extern rtx block_label (basic_block);
 764 extern bool forwarder_block_p (basic_block);
 765 extern bool purge_all_dead_edges (int);
 766 extern bool purge_dead_edges (basic_block);
 767 extern void find_sub_basic_blocks (basic_block);
 768 extern void find_many_sub_basic_blocks (sbitmap);
 769 extern void rtl_make_eh_edge (sbitmap *, basic_block, rtx);
 770 extern bool can_fallthru (basic_block, basic_block);
 771 extern bool could_fall_through (basic_block, basic_block);
 772 extern void flow_nodes_print (const char *, const sbitmap, FILE *);
 773 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
 774 extern void alloc_aux_for_block (basic_block, int);
 775 extern void alloc_aux_for_blocks (int);
 776 extern void clear_aux_for_blocks (void);
 777 extern void free_aux_for_blocks (void);
 778 extern void alloc_aux_for_edge (edge, int);
 779 extern void alloc_aux_for_edges (int);
 780 extern void clear_aux_for_edges (void);
 781 extern void free_aux_for_edges (void);
 782 extern void find_basic_blocks (rtx, int, FILE *);
 783 extern bool cleanup_cfg (int);
 784 extern bool delete_unreachable_blocks (void);
 785 extern bool merge_seq_blocks (void);
 786
 787 typedef struct conflict_graph_def *conflict_graph;
 788
 789 /* Callback function when enumerating conflicts.  The arguments are
 790    the smaller and larger regno in the conflict.  Returns zero if
 791    enumeration is to continue, nonzero to halt enumeration.  */
 792 typedef int (*conflict_graph_enum_fn) (int, int, void *);
 793
 794
 795 /* Prototypes of operations on conflict graphs.  */
 796
 797 extern conflict_graph conflict_graph_new
 798  (int);
 799 extern void conflict_graph_delete (conflict_graph);
 800 extern int conflict_graph_add (conflict_graph, int, int);
 801 extern int conflict_graph_conflict_p (conflict_graph, int, int);
 802 extern void conflict_graph_enum (conflict_graph, int, conflict_graph_enum_fn,
 803                                  void *);
 804 extern void conflict_graph_merge_regs (conflict_graph, int, int);
 805 extern void conflict_graph_print (conflict_graph, FILE*);
 806 extern bool mark_dfs_back_edges (void);
 807 extern void set_edge_can_fallthru_flag (void);
 808 extern void update_br_prob_note (basic_block);
 809 extern void fixup_abnormal_edges (void);
 810 extern bool inside_basic_block_p (rtx);
 811 extern bool control_flow_insn_p (rtx);
 812
 813 /* In bb-reorder.c */
 814 extern void reorder_basic_blocks (unsigned int);
 815 extern void duplicate_computed_gotos (void);
 816 extern void partition_hot_cold_basic_blocks (void);
 817
 818 /* In cfg.c */
 819 extern void alloc_rbi_pool (void);
 820 extern void initialize_bb_rbi (basic_block bb);
 821 extern void free_rbi_pool (void);
 822
 823 /* In dominance.c */
 824
 825 enum cdi_direction
 826 {
 827   CDI_DOMINATORS,
 828   CDI_POST_DOMINATORS
 829 };
 830
 831 enum dom_state
 832 {
 833   DOM_NONE,             /* Not computed at all.  */
 834   DOM_NO_FAST_QUERY,    /* The data is OK, but the fast query data are not usable.  */
 835   DOM_OK                /* Everything is ok.  */
 836 };
 837
 838 extern enum dom_state dom_computed[2];
 839
 840 extern bool dom_info_available_p (enum cdi_direction);
 841 extern void calculate_dominance_info (enum cdi_direction);
 842 extern void free_dominance_info (enum cdi_direction);
 843 extern basic_block nearest_common_dominator (enum cdi_direction,
 844                                              basic_block, basic_block);
 845 extern void set_immediate_dominator (enum cdi_direction, basic_block,
 846                                      basic_block);
 847 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
 848 extern bool dominated_by_p (enum cdi_direction, basic_block, basic_block);
 849 extern int get_dominated_by (enum cdi_direction, basic_block, basic_block **);
 850 extern unsigned get_dominated_by_region (enum cdi_direction, basic_block *,
 851                                          unsigned, basic_block *);
 852 extern void add_to_dominance_info (enum cdi_direction, basic_block);
 853 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
 854 basic_block recount_dominator (enum cdi_direction, basic_block);
 855 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
 856                                            basic_block);
 857 extern void iterate_fix_dominators (enum cdi_direction, basic_block *, int);
 858 extern void verify_dominators (enum cdi_direction);
 859 extern basic_block first_dom_son (enum cdi_direction, basic_block);
 860 extern basic_block next_dom_son (enum cdi_direction, basic_block);
 861 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
 862 extern void break_superblocks (void);
 863 extern void check_bb_profile (basic_block, FILE *);
 864 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
 865
 866 #include "cfghooks.h"
 867
 868 #endif /* GCC_BASIC_BLOCK_H */