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_operation (TO, TO, FROM, BITMAP_AND)
  54
  55 /* `and' the complement of a register set with a register set.  */
  56 #define AND_COMPL_REG_SET(TO, FROM) \
  57   bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
  58
  59 /* Inclusive or a register set with a second register set.  */
  60 #define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
  61
  62 /* Exclusive or a register set with a second register set.  */
  63 #define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
  64
  65 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  66 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  67   bitmap_ior_and_compl (TO, FROM1, FROM2)
  68
  69 /* Clear a single register in a register set.  */
  70 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  71
  72 /* Set a single register in a register set.  */
  73 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  74
  75 /* Return true if a register is set in a register set.  */
  76 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  77
  78 /* Copy the hard registers in a register set to the hard register set.  */
  79 extern void reg_set_to_hard_reg_set (HARD_REG_SET *, bitmap);
  80 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  81 do {                                                                    \
  82   CLEAR_HARD_REG_SET (TO);                                              \
  83   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  84 } while (0)
  85
  86 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  87    register number and executing CODE for all registers that are set.  */
  88 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE)            \
  89   do                                                                    \
  90     {                                                                   \
  91       bitmap_iterator bi;                                               \
  92                                                                         \
  93       EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, bi)                \
  94         {                                                               \
  95           CODE;                                                         \
  96         }                                                               \
  97     } while (0)
  98
  99 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
 100    REGNUM to the register number and executing CODE for all registers that are
 101    set in the first regset and not set in the second.  */
 102 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
 103   do                                                                    \
 104     {                                                                   \
 105       bitmap_iterator bi;                                               \
 106                                                                         \
 107       EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, bi) \
 108         {                                                               \
 109           CODE;                                                         \
 110         }                                                               \
 111     } while (0)
 112
 113 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
 114    REGNUM to the register number and executing CODE for all registers that are
 115    set in both regsets.  */
 116 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
 117   do                                                                    \
 118     {                                                                   \
 119       bitmap_iterator bi;                                               \
 120                                                                         \
 121       EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, bi)      \
 122         {                                                               \
 123           CODE;                                                         \
 124         }                                                               \
 125     } while (0)
 126
 127 /* Allocate a register set with oballoc.  */
 128 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
 129
 130 /* Initialize a register set.  Returns the new register set.  */
 131 #define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD, 1)
 132
 133 /* Do any cleanup needed on a regset when it is no longer used.  */
 134 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
 135
 136 /* Do any one-time initializations needed for regsets.  */
 137 #define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
 138
 139 /* Grow any tables needed when the number of registers is calculated
 140    or extended.  For the linked list allocation, nothing needs to
 141    be done, other than zero the statistics on the first allocation.  */
 142 #define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
 143
 144 /* Type we use to hold basic block counters.  Should be at least
 145    64bit.  Although a counter cannot be negative, we use a signed
 146    type, because erroneous negative counts can be generated when the
 147    flow graph is manipulated by various optimizations.  A signed type
 148    makes those easy to detect.  */
 149 typedef HOST_WIDEST_INT gcov_type;
 150
 151 /* Control flow edge information.  */
 152 struct edge_def GTY(())
 153 {
 154   /* The two blocks at the ends of the edge.  */
 155   struct basic_block_def *src;
 156   struct basic_block_def *dest;
 157
 158   /* Instructions queued on the edge.  */
 159   union edge_def_insns {
 160     rtx GTY ((tag ("0"))) r;
 161     tree GTY ((tag ("1"))) t;
 162   } GTY ((desc ("ir_type ()"))) insns;
 163
 164   /* Auxiliary info specific to a pass.  */
 165   PTR GTY ((skip (""))) aux;
 166
 167   /* Location of any goto implicit in the edge, during tree-ssa.  */
 168   source_locus goto_locus;
 169
 170   int flags;                    /* see EDGE_* below  */
 171   int probability;              /* biased by REG_BR_PROB_BASE */
 172   gcov_type count;              /* Expected number of executions calculated
 173                                    in profile.c  */
 174 };
 175
 176 typedef struct edge_def *edge;
 177 DEF_VEC_GC_P(edge);
 178
 179 #define EDGE_FALLTHRU           1       /* 'Straight line' flow */
 180 #define EDGE_ABNORMAL           2       /* Strange flow, like computed
 181                                            label, or eh */
 182 #define EDGE_ABNORMAL_CALL      4       /* Call with abnormal exit
 183                                            like an exception, or sibcall */
 184 #define EDGE_EH                 8       /* Exception throw */
 185 #define EDGE_FAKE               16      /* Not a real edge (profile.c) */
 186 #define EDGE_DFS_BACK           32      /* A backwards edge */
 187 #define EDGE_CAN_FALLTHRU       64      /* Candidate for straight line
 188                                            flow.  */
 189 #define EDGE_IRREDUCIBLE_LOOP   128     /* Part of irreducible loop.  */
 190 #define EDGE_SIBCALL            256     /* Edge from sibcall to exit.  */
 191 #define EDGE_LOOP_EXIT          512     /* Exit of a loop.  */
 192 #define EDGE_TRUE_VALUE         1024    /* Edge taken when controlling
 193                                            predicate is nonzero.  */
 194 #define EDGE_FALSE_VALUE        2048    /* Edge taken when controlling
 195                                            predicate is zero.  */
 196 #define EDGE_EXECUTABLE         4096    /* Edge is executable.  Only
 197                                            valid during SSA-CCP.  */
 198 #define EDGE_CROSSING           8192    /* Edge crosses between hot
 199                                            and cold sections, when we
 200                                            do partitioning.  */
 201 #define EDGE_ALL_FLAGS         16383
 202
 203 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 204
 205 /* Counter summary from the last set of coverage counts read by
 206    profile.c.  */
 207 extern const struct gcov_ctr_summary *profile_info;
 208
 209 /* Declared in cfgloop.h.  */
 210 struct loop;
 211 struct loops;
 212
 213 /* Declared in tree-flow.h.  */
 214 struct bb_ann_d;
 215
 216 /* A basic block is a sequence of instructions with only entry and
 217    only one exit.  If any one of the instructions are executed, they
 218    will all be executed, and in sequence from first to last.
 219
 220    There may be COND_EXEC instructions in the basic block.  The
 221    COND_EXEC *instructions* will be executed -- but if the condition
 222    is false the conditionally executed *expressions* will of course
 223    not be executed.  We don't consider the conditionally executed
 224    expression (which might have side-effects) to be in a separate
 225    basic block because the program counter will always be at the same
 226    location after the COND_EXEC instruction, regardless of whether the
 227    condition is true or not.
 228
 229    Basic blocks need not start with a label nor end with a jump insn.
 230    For example, a previous basic block may just "conditionally fall"
 231    into the succeeding basic block, and the last basic block need not
 232    end with a jump insn.  Block 0 is a descendant of the entry block.
 233
 234    A basic block beginning with two labels cannot have notes between
 235    the labels.
 236
 237    Data for jump tables are stored in jump_insns that occur in no
 238    basic block even though these insns can follow or precede insns in
 239    basic blocks.  */
 240
 241 /* Basic block information indexed by block number.  */
 242 struct basic_block_def GTY((chain_next ("%h.next_bb"), chain_prev ("%h.prev_bb")))
 243 {
 244   /* The first and last insns of the block.  */
 245   rtx head_;
 246   rtx end_;
 247
 248   /* Pointers to the first and last trees of the block.  */
 249   tree stmt_list;
 250
 251   /* The edges into and out of the block.  */
 252   VEC(edge) *preds;
 253   VEC(edge) *succs;
 254
 255   /* Liveness info.  */
 256
 257   /* The registers that are modified within this in block.  */
 258   bitmap GTY ((skip (""))) local_set;
 259   /* The registers that are conditionally modified within this block.
 260      In other words, registers that are set only as part of a
 261      COND_EXEC.  */
 262   bitmap GTY ((skip (""))) cond_local_set;
 263   /* The registers that are live on entry to this block.
 264
 265      Note that in SSA form, global_live_at_start does not reflect the
 266      use of regs in phi functions, since the liveness of these regs
 267      may depend on which edge was taken into the block.  */
 268   bitmap GTY ((skip (""))) global_live_at_start;
 269   /* The registers that are live on exit from this block.  */
 270   bitmap GTY ((skip (""))) global_live_at_end;
 271
 272   /* Auxiliary info specific to a pass.  */
 273   PTR GTY ((skip (""))) aux;
 274
 275   /* Innermost loop containing the block.  */
 276   struct loop * GTY ((skip (""))) loop_father;
 277
 278   /* The dominance and postdominance information node.  */
 279   struct et_node * GTY ((skip (""))) dom[2];
 280
 281   /* Previous and next blocks in the chain.  */
 282   struct basic_block_def *prev_bb;
 283   struct basic_block_def *next_bb;
 284
 285   /* The data used by basic block copying and reordering functions.  */
 286   struct reorder_block_def * GTY ((skip (""))) rbi;
 287
 288   /* Annotations used at the tree level.  */
 289   struct bb_ann_d *tree_annotations;
 290
 291   /* Expected number of executions: calculated in profile.c.  */
 292   gcov_type count;
 293
 294   /* The index of this block.  */
 295   int index;
 296
 297   /* The loop depth of this block.  */
 298   int loop_depth;
 299
 300   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 301   int frequency;
 302
 303   /* Various flags.  See BB_* below.  */
 304   int flags;
 305 };
 306
 307 typedef struct basic_block_def *basic_block;
 308
 309 /* Structure to hold information about the blocks during reordering and
 310    copying.  */
 311
 312 typedef struct reorder_block_def
 313 {
 314   rtx header;
 315   rtx footer;
 316   basic_block next;
 317   basic_block original;
 318   /* Used by loop copying.  */
 319   basic_block copy;
 320   int duplicated;
 321   int copy_number;
 322
 323   /* These fields are used by bb-reorder pass.  */
 324   int visited;
 325 } *reorder_block_def_p;
 326
 327 #define BB_FREQ_MAX 10000
 328
 329 /* Masks for basic_block.flags.  */
 330 #define BB_DIRTY                1
 331 #define BB_NEW                  2
 332 #define BB_REACHABLE            4
 333 #define BB_VISITED              8
 334 #define BB_IRREDUCIBLE_LOOP     16
 335 #define BB_SUPERBLOCK           32
 336 #define BB_DISABLE_SCHEDULE     64
 337
 338 #define BB_HOT_PARTITION        128
 339 #define BB_COLD_PARTITION       256
 340 #define BB_UNPARTITIONED        0
 341
 342 /* Partitions, to be used when partitioning hot and cold basic blocks into
 343    separate sections.  */
 344 #define BB_PARTITION(bb) ((bb)->flags & (BB_HOT_PARTITION|BB_COLD_PARTITION))
 345 #define BB_SET_PARTITION(bb, part) do {                                 \
 346   basic_block bb_ = (bb);                                               \
 347   bb_->flags = ((bb_->flags & ~(BB_HOT_PARTITION|BB_COLD_PARTITION))    \
 348                 | (part));                                              \
 349 } while (0)
 350
 351 #define BB_COPY_PARTITION(dstbb, srcbb) \
 352   BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb))
 353
 354 /* Number of basic blocks in the current function.  */
 355
 356 extern int n_basic_blocks;
 357
 358 /* First free basic block number.  */
 359
 360 extern int last_basic_block;
 361
 362 /* Number of edges in the current function.  */
 363
 364 extern int n_edges;
 365
 366 /* Signalize the status of profile information in the CFG.  */
 367 extern enum profile_status
 368 {
 369   PROFILE_ABSENT,
 370   PROFILE_GUESSED,
 371   PROFILE_READ
 372 } profile_status;
 373
 374 /* Index by basic block number, get basic block struct info.  */
 375
 376 extern GTY(()) varray_type basic_block_info;
 377
 378 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 379
 380 /* For iterating over basic blocks.  */
 381 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 382   for (BB = FROM; BB != TO; BB = BB->DIR)
 383
 384 #define FOR_EACH_BB(BB) \
 385   FOR_BB_BETWEEN (BB, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
 386
 387 #define FOR_EACH_BB_REVERSE(BB) \
 388   FOR_BB_BETWEEN (BB, EXIT_BLOCK_PTR->prev_bb, ENTRY_BLOCK_PTR, prev_bb)
 389
 390 /* For iterating over insns in basic block.  */
 391 #define FOR_BB_INSNS(BB, INSN)                  \
 392   for ((INSN) = BB_HEAD (BB);                   \
 393        (INSN) != NEXT_INSN (BB_END (BB));       \
 394        (INSN) = NEXT_INSN (INSN))
 395
 396 #define FOR_BB_INSNS_REVERSE(BB, INSN)          \
 397   for ((INSN) = BB_END (BB);                    \
 398        (INSN) != PREV_INSN (BB_HEAD (BB));      \
 399        (INSN) = PREV_INSN (INSN))
 400
 401 /* Cycles through _all_ basic blocks, even the fake ones (entry and
 402    exit block).  */
 403
 404 #define FOR_ALL_BB(BB) \
 405   for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
 406
 407 /* What registers are live at the setjmp call.  */
 408
 409 extern regset regs_live_at_setjmp;
 410
 411 /* Special labels found during CFG build.  */
 412
 413 extern GTY(()) rtx label_value_list;
 414
 415 extern struct obstack flow_obstack;
 416
 417 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 418    If the value is REG_BLOCK_GLOBAL (-2),
 419    it means (REG n) is used in more than one basic block.
 420    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 421    This information remains valid for the rest of the compilation
 422    of the current function; it is used to control register allocation.  */
 423
 424 #define REG_BLOCK_UNKNOWN -1
 425 #define REG_BLOCK_GLOBAL -2
 426
 427 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 428 \f
 429 /* Stuff for recording basic block info.  */
 430
 431 #define BB_HEAD(B)      (B)->head_
 432 #define BB_END(B)       (B)->end_
 433
 434 /* Special block numbers [markers] for entry and exit.  */
 435 #define ENTRY_BLOCK (-1)
 436 #define EXIT_BLOCK (-2)
 437
 438 /* Special block number not valid for any block.  */
 439 #define INVALID_BLOCK (-3)
 440
 441 /* Similarly, block pointers for the edge list.  */
 442 extern GTY(()) basic_block ENTRY_BLOCK_PTR;
 443 extern GTY(()) basic_block EXIT_BLOCK_PTR;
 444
 445 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 446 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 447
 448 extern void compute_bb_for_insn (void);
 449 extern void free_bb_for_insn (void);
 450 extern void update_bb_for_insn (basic_block);
 451
 452 extern void free_basic_block_vars (void);
 453
 454 extern void insert_insn_on_edge (rtx, edge);
 455 bool safe_insert_insn_on_edge (rtx, edge);
 456
 457 extern void commit_edge_insertions (void);
 458 extern void commit_edge_insertions_watch_calls (void);
 459
 460 extern void remove_fake_edges (void);
 461 extern void remove_fake_exit_edges (void);
 462 extern void add_noreturn_fake_exit_edges (void);
 463 extern void connect_infinite_loops_to_exit (void);
 464 extern edge unchecked_make_edge (basic_block, basic_block, int);
 465 extern edge cached_make_edge (sbitmap *, basic_block, basic_block, int);
 466 extern edge make_edge (basic_block, basic_block, int);
 467 extern edge make_single_succ_edge (basic_block, basic_block, int);
 468 extern void remove_edge (edge);
 469 extern void redirect_edge_succ (edge, basic_block);
 470 extern edge redirect_edge_succ_nodup (edge, basic_block);
 471 extern void redirect_edge_pred (edge, basic_block);
 472 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
 473 extern void clear_bb_flags (void);
 474 extern void flow_reverse_top_sort_order_compute (int *);
 475 extern int flow_depth_first_order_compute (int *, int *);
 476 extern int dfs_enumerate_from (basic_block, int,
 477                                bool (*)(basic_block, void *),
 478                                basic_block *, int, void *);
 479 extern void compute_dominance_frontiers (bitmap *);
 480 extern void dump_edge_info (FILE *, edge, int);
 481 extern void brief_dump_cfg (FILE *);
 482 extern void clear_edges (void);
 483 extern void mark_critical_edges (void);
 484 extern rtx first_insn_after_basic_block_note (basic_block);
 485
 486 /* Structure to group all of the information to process IF-THEN and
 487    IF-THEN-ELSE blocks for the conditional execution support.  This
 488    needs to be in a public file in case the IFCVT macros call
 489    functions passing the ce_if_block data structure.  */
 490
 491 typedef struct ce_if_block
 492 {
 493   basic_block test_bb;                  /* First test block.  */
 494   basic_block then_bb;                  /* THEN block.  */
 495   basic_block else_bb;                  /* ELSE block or NULL.  */
 496   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 497   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 498   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 499   int num_and_and_blocks;               /* # of && blocks.  */
 500   int num_or_or_blocks;                 /* # of || blocks.  */
 501   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 502   int and_and_p;                        /* Complex test is &&.  */
 503   int num_then_insns;                   /* # of insns in THEN block.  */
 504   int num_else_insns;                   /* # of insns in ELSE block.  */
 505   int pass;                             /* Pass number.  */
 506
 507 #ifdef IFCVT_EXTRA_FIELDS
 508   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 509 #endif
 510
 511 } ce_if_block_t;
 512
 513 /* This structure maintains an edge list vector.  */
 514 struct edge_list
 515 {
 516   int num_blocks;
 517   int num_edges;
 518   edge *index_to_edge;
 519 };
 520
 521 /* This is the value which indicates no edge is present.  */
 522 #define EDGE_INDEX_NO_EDGE      -1
 523
 524 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 525    if there is no edge between the 2 basic blocks.  */
 526 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 527
 528 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 529    block which is either the pred or succ end of the indexed edge.  */
 530 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 531 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 532
 533 /* INDEX_EDGE returns a pointer to the edge.  */
 534 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 535
 536 /* Number of edges in the compressed edge list.  */
 537 #define NUM_EDGES(el)                   ((el)->num_edges)
 538
 539 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 540 #define FALLTHRU_EDGE(bb)               (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 541                                          ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
 542
 543 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 544 #define BRANCH_EDGE(bb)                 (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 545                                          ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
 546
 547 /* Return expected execution frequency of the edge E.  */
 548 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 549                                           * (e)->probability \
 550                                           + REG_BR_PROB_BASE / 2) \
 551                                          / REG_BR_PROB_BASE)
 552
 553 /* Return nonzero if edge is critical.  */
 554 #define EDGE_CRITICAL_P(e)              (EDGE_COUNT ((e)->src->succs) >= 2 \
 555                                          && EDGE_COUNT ((e)->dest->preds) >= 2)
 556
 557 #define EDGE_COUNT(ev)                  VEC_length (edge, (ev))
 558 #define EDGE_I(ev,i)                    VEC_index  (edge, (ev), (i))
 559 #define EDGE_PRED(bb,i)                 VEC_index  (edge, (bb)->preds, (i))
 560 #define EDGE_SUCC(bb,i)                 VEC_index  (edge, (bb)->succs, (i))
 561
 562 /* Iterator object for edges.  */
 563
 564 typedef struct {
 565   unsigned index;
 566   VEC(edge) *container;
 567 } edge_iterator;
 568
 569 /* Return an iterator pointing to the start of an edge vector.  */
 570 static inline edge_iterator
 571 ei_start (VEC(edge) *ev)
 572 {
 573   edge_iterator i;
 574
 575   i.index = 0;
 576   i.container = ev;
 577
 578   return i;
 579 }
 580
 581 /* Return an iterator pointing to the last element of an edge
 582    vector. */
 583 static inline edge_iterator
 584 ei_last (VEC(edge) *ev)
 585 {
 586   edge_iterator i;
 587
 588   i.index = EDGE_COUNT (ev) - 1;
 589   i.container = ev;
 590
 591   return i;
 592 }
 593
 594 /* Is the iterator `i' at the end of the sequence?  */
 595 static inline bool
 596 ei_end_p (edge_iterator i)
 597 {
 598   return (i.index == EDGE_COUNT (i.container));
 599 }
 600
 601 /* Is the iterator `i' at one position before the end of the
 602    sequence?  */
 603 static inline bool
 604 ei_one_before_end_p (edge_iterator i)
 605 {
 606   return (i.index + 1 == EDGE_COUNT (i.container));
 607 }
 608
 609 /* Advance the iterator to the next element.  */
 610 static inline void
 611 ei_next (edge_iterator *i)
 612 {
 613   gcc_assert (i->index < EDGE_COUNT (i->container));
 614   i->index++;
 615 }
 616
 617 /* Move the iterator to the previous element.  */
 618 static inline void
 619 ei_prev (edge_iterator *i)
 620 {
 621   gcc_assert (i->index > 0);
 622   i->index--;
 623 }
 624
 625 /* Return the edge pointed to by the iterator `i'.  */
 626 static inline edge
 627 ei_edge (edge_iterator i)
 628 {
 629   return EDGE_I (i.container, i.index);
 630 }
 631
 632 /* Return an edge pointed to by the iterator.  Do it safely so that
 633    NULL is returned when the iterator is pointing at the end of the
 634    sequence.  */
 635 static inline edge
 636 ei_safe_edge (edge_iterator i)
 637 {
 638   return !ei_end_p (i) ? ei_edge (i) : NULL;
 639 }
 640
 641 /* This macro serves as a convenient way to iterate each edge in a
 642    vector of predecessor or successor edges.  It must not be used when
 643    an element might be removed during the traversal, otherwise
 644    elements will be missed.  Instead, use a for-loop like that shown
 645    in the following pseudo-code:
 646
 647    FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 648      {
 649         IF (e != taken_edge)
 650           ssa_remove_edge (e);
 651         ELSE
 652           ei_next (&ei);
 653      }
 654 */
 655
 656 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC) \
 657   for ((EDGE) = NULL, (ITER) = ei_start ((EDGE_VEC)); \
 658        ((EDGE) = ei_safe_edge ((ITER))); \
 659        ei_next (&(ITER)))
 660
 661 struct edge_list * create_edge_list (void);
 662 void free_edge_list (struct edge_list *);
 663 void print_edge_list (FILE *, struct edge_list *);
 664 void verify_edge_list (FILE *, struct edge_list *);
 665 int find_edge_index (struct edge_list *, basic_block, basic_block);
 666 edge find_edge (basic_block, basic_block);
 667
 668
 669 enum update_life_extent
 670 {
 671   UPDATE_LIFE_LOCAL = 0,
 672   UPDATE_LIFE_GLOBAL = 1,
 673   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 674 };
 675
 676 /* Flags for life_analysis and update_life_info.  */
 677
 678 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 679 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 680 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 681 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 682 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 683 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 684                                            by dead code removal.  */
 685 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 686 #define PROP_EQUAL_NOTES        128     /* Take into account REG_EQUAL notes.  */
 687 #define PROP_SCAN_DEAD_STORES   256     /* Scan for dead code.  */
 688 #define PROP_ASM_SCAN           512     /* Internal flag used within flow.c
 689                                            to flag analysis of asms.  */
 690 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 691                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 692                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 693                                  | PROP_ALLOW_CFG_CHANGES \
 694                                  | PROP_SCAN_DEAD_STORES)
 695 #define PROP_POSTRELOAD         (PROP_DEATH_NOTES  \
 696                                  | PROP_KILL_DEAD_CODE  \
 697                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 698                                  | PROP_SCAN_DEAD_STORES)
 699
 700 #define CLEANUP_EXPENSIVE       1       /* Do relatively expensive optimizations
 701                                            except for edge forwarding */
 702 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 703 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 704                                            to care REG_DEAD notes.  */
 705 #define CLEANUP_PRE_LOOP        8       /* Take care to preserve syntactic loop
 706                                            notes.  */
 707 #define CLEANUP_UPDATE_LIFE     16      /* Keep life information up to date.  */
 708 #define CLEANUP_THREADING       32      /* Do jump threading.  */
 709 #define CLEANUP_NO_INSN_DEL     64      /* Do not try to delete trivially dead
 710                                            insns.  */
 711 #define CLEANUP_CFGLAYOUT       128     /* Do cleanup in cfglayout mode.  */
 712 #define CLEANUP_LOG_LINKS       256     /* Update log links.  */
 713
 714 extern void life_analysis (FILE *, int);
 715 extern int update_life_info (sbitmap, enum update_life_extent, int);
 716 extern int update_life_info_in_dirty_blocks (enum update_life_extent, int);
 717 extern int count_or_remove_death_notes (sbitmap, int);
 718 extern int propagate_block (basic_block, regset, regset, regset, int);
 719
 720 struct propagate_block_info;
 721 extern rtx propagate_one_insn (struct propagate_block_info *, rtx);
 722 extern struct propagate_block_info *init_propagate_block_info
 723  (basic_block, regset, regset, regset, int);
 724 extern void free_propagate_block_info (struct propagate_block_info *);
 725
 726 /* In lcm.c */
 727 extern struct edge_list *pre_edge_lcm (FILE *, int, sbitmap *, sbitmap *,
 728                                        sbitmap *, sbitmap *, sbitmap **,
 729                                        sbitmap **);
 730 extern struct edge_list *pre_edge_rev_lcm (FILE *, int, sbitmap *,
 731                                            sbitmap *, sbitmap *,
 732                                            sbitmap *, sbitmap **,
 733                                            sbitmap **);
 734 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
 735 extern int optimize_mode_switching (FILE *);
 736
 737 /* In emit-rtl.c.  */
 738 extern rtx emit_block_insn_after (rtx, rtx, basic_block);
 739 extern rtx emit_block_insn_before (rtx, rtx, basic_block);
 740
 741 /* In predict.c */
 742 extern void estimate_probability (struct loops *);
 743 extern void expected_value_to_br_prob (void);
 744 extern bool maybe_hot_bb_p (basic_block);
 745 extern bool probably_cold_bb_p (basic_block);
 746 extern bool probably_never_executed_bb_p (basic_block);
 747 extern bool tree_predicted_by_p (basic_block, enum br_predictor);
 748 extern bool rtl_predicted_by_p (basic_block, enum br_predictor);
 749 extern void tree_predict_edge (edge, enum br_predictor, int);
 750 extern void rtl_predict_edge (edge, enum br_predictor, int);
 751 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
 752 extern void guess_outgoing_edge_probabilities (basic_block);
 753
 754 /* In flow.c */
 755 extern void init_flow (void);
 756 extern void debug_bb (basic_block);
 757 extern basic_block debug_bb_n (int);
 758 extern void dump_regset (regset, FILE *);
 759 extern void debug_regset (regset);
 760 extern void allocate_reg_life_data (void);
 761 extern void allocate_bb_life_data (void);
 762 extern void expunge_block (basic_block);
 763 extern void link_block (basic_block, basic_block);
 764 extern void unlink_block (basic_block);
 765 extern void compact_blocks (void);
 766 extern basic_block alloc_block (void);
 767 extern void find_unreachable_blocks (void);
 768 extern int delete_noop_moves (void);
 769 extern basic_block force_nonfallthru (edge);
 770 extern rtx block_label (basic_block);
 771 extern bool forwarder_block_p (basic_block);
 772 extern bool purge_all_dead_edges (int);
 773 extern bool purge_dead_edges (basic_block);
 774 extern void find_sub_basic_blocks (basic_block);
 775 extern void find_many_sub_basic_blocks (sbitmap);
 776 extern void rtl_make_eh_edge (sbitmap *, basic_block, rtx);
 777 extern bool can_fallthru (basic_block, basic_block);
 778 extern bool could_fall_through (basic_block, basic_block);
 779 extern void flow_nodes_print (const char *, const sbitmap, FILE *);
 780 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
 781 extern void alloc_aux_for_block (basic_block, int);
 782 extern void alloc_aux_for_blocks (int);
 783 extern void clear_aux_for_blocks (void);
 784 extern void free_aux_for_blocks (void);
 785 extern void alloc_aux_for_edge (edge, int);
 786 extern void alloc_aux_for_edges (int);
 787 extern void clear_aux_for_edges (void);
 788 extern void free_aux_for_edges (void);
 789 extern void find_basic_blocks (rtx, int, FILE *);
 790 extern bool cleanup_cfg (int);
 791 extern bool delete_unreachable_blocks (void);
 792 extern bool merge_seq_blocks (void);
 793
 794 typedef struct conflict_graph_def *conflict_graph;
 795
 796 /* Callback function when enumerating conflicts.  The arguments are
 797    the smaller and larger regno in the conflict.  Returns zero if
 798    enumeration is to continue, nonzero to halt enumeration.  */
 799 typedef int (*conflict_graph_enum_fn) (int, int, void *);
 800
 801
 802 /* Prototypes of operations on conflict graphs.  */
 803
 804 extern conflict_graph conflict_graph_new
 805  (int);
 806 extern void conflict_graph_delete (conflict_graph);
 807 extern int conflict_graph_add (conflict_graph, int, int);
 808 extern int conflict_graph_conflict_p (conflict_graph, int, int);
 809 extern void conflict_graph_enum (conflict_graph, int, conflict_graph_enum_fn,
 810                                  void *);
 811 extern void conflict_graph_merge_regs (conflict_graph, int, int);
 812 extern void conflict_graph_print (conflict_graph, FILE*);
 813 extern conflict_graph conflict_graph_compute (regset, partition);
 814 extern bool mark_dfs_back_edges (void);
 815 extern void set_edge_can_fallthru_flag (void);
 816 extern void update_br_prob_note (basic_block);
 817 extern void fixup_abnormal_edges (void);
 818 extern bool inside_basic_block_p (rtx);
 819 extern bool control_flow_insn_p (rtx);
 820
 821 /* In bb-reorder.c */
 822 extern void reorder_basic_blocks (unsigned int);
 823 extern void partition_hot_cold_basic_blocks (void);
 824
 825 /* In cfg.c */
 826 extern void alloc_rbi_pool (void);
 827 extern void initialize_bb_rbi (basic_block bb);
 828 extern void free_rbi_pool (void);
 829
 830 /* In dominance.c */
 831
 832 enum cdi_direction
 833 {
 834   CDI_DOMINATORS,
 835   CDI_POST_DOMINATORS
 836 };
 837
 838 enum dom_state
 839 {
 840   DOM_NONE,             /* Not computed at all.  */
 841   DOM_CONS_OK,          /* The data is conservatively OK, i.e. if it says you that A dominates B,
 842                            it indeed does.  */
 843   DOM_NO_FAST_QUERY,    /* The data is OK, but the fast query data are not usable.  */
 844   DOM_OK                /* Everything is ok.  */
 845 };
 846
 847 extern enum dom_state dom_computed[2];
 848
 849 extern void calculate_dominance_info (enum cdi_direction);
 850 extern void free_dominance_info (enum cdi_direction);
 851 extern basic_block nearest_common_dominator (enum cdi_direction,
 852                                              basic_block, basic_block);
 853 extern void set_immediate_dominator (enum cdi_direction, basic_block,
 854                                      basic_block);
 855 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
 856 extern bool dominated_by_p (enum cdi_direction, basic_block, basic_block);
 857 extern int get_dominated_by (enum cdi_direction, basic_block, basic_block **);
 858 extern unsigned get_dominated_by_region (enum cdi_direction, basic_block *,
 859                                          unsigned, basic_block *);
 860 extern void add_to_dominance_info (enum cdi_direction, basic_block);
 861 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
 862 basic_block recount_dominator (enum cdi_direction, basic_block);
 863 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
 864                                            basic_block);
 865 extern void iterate_fix_dominators (enum cdi_direction, basic_block *, int);
 866 extern void verify_dominators (enum cdi_direction);
 867 extern basic_block first_dom_son (enum cdi_direction, basic_block);
 868 extern basic_block next_dom_son (enum cdi_direction, basic_block);
 869 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
 870 extern void break_superblocks (void);
 871 extern void check_bb_profile (basic_block, FILE *);
 872 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
 873
 874 #include "cfghooks.h"
 875
 876 #endif /* GCC_BASIC_BLOCK_H */