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