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