gcc/basic-block.h

   1 /* Define control and data flow tables, and regsets.
   2    Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #ifndef GCC_BASIC_BLOCK_H
  23 #define GCC_BASIC_BLOCK_H
  24
  25 #include "bitmap.h"
  26 #include "sbitmap.h"
  27 #include "varray.h"
  28 #include "partition.h"
  29 #include "hard-reg-set.h"
  30 #include "predict.h"
  31 #include "vec.h"
  32 #include "function.h"
  33
  34 /* Head of register set linked list.  */
  35 typedef bitmap_head regset_head;
  36
  37 /* A pointer to a regset_head.  */
  38 typedef bitmap regset;
  39
  40 /* Allocate a register set with oballoc.  */
  41 #define ALLOC_REG_SET(OBSTACK) BITMAP_ALLOC (OBSTACK)
  42
  43 /* Do any cleanup needed on a regset when it is no longer used.  */
  44 #define FREE_REG_SET(REGSET) BITMAP_FREE (REGSET)
  45
  46 /* Initialize a new regset.  */
  47 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, &reg_obstack)
  48
  49 /* Clear a register set by freeing up the linked list.  */
  50 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  51
  52 /* Copy a register set to another register set.  */
  53 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  54
  55 /* Compare two register sets.  */
  56 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  57
  58 /* `and' a register set with a second register set.  */
  59 #define AND_REG_SET(TO, FROM) bitmap_and_into (TO, FROM)
  60
  61 /* `and' the complement of a register set with a register set.  */
  62 #define AND_COMPL_REG_SET(TO, FROM) bitmap_and_compl_into (TO, FROM)
  63
  64 /* Inclusive or a register set with a second register set.  */
  65 #define IOR_REG_SET(TO, FROM) bitmap_ior_into (TO, FROM)
  66
  67 /* Exclusive or a register set with a second register set.  */
  68 #define XOR_REG_SET(TO, FROM) bitmap_xor_into (TO, FROM)
  69
  70 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  71 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  72   bitmap_ior_and_compl_into (TO, FROM1, FROM2)
  73
  74 /* Clear a single register in a register set.  */
  75 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  76
  77 /* Set a single register in a register set.  */
  78 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  79
  80 /* Return true if a register is set in a register set.  */
  81 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  82
  83 /* Copy the hard registers in a register set to the hard register set.  */
  84 extern void reg_set_to_hard_reg_set (HARD_REG_SET *, bitmap);
  85 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  86 do {                                                                    \
  87   CLEAR_HARD_REG_SET (TO);                                              \
  88   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  89 } while (0)
  90
  91 typedef bitmap_iterator reg_set_iterator;
  92
  93 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  94    register number and executing CODE for all registers that are set.  */
  95 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, RSI)     \
  96   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, RSI)
  97
  98 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  99    REGNUM to the register number and executing CODE for all registers that are
 100    set in the first regset and not set in the second.  */
 101 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
 102   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI)
 103
 104 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
 105    REGNUM to the register number and executing CODE for all registers that are
 106    set in both regsets.  */
 107 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
 108   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI) \
 109
 110 /* Type we use to hold basic block counters.  Should be at least
 111    64bit.  Although a counter cannot be negative, we use a signed
 112    type, because erroneous negative counts can be generated when the
 113    flow graph is manipulated by various optimizations.  A signed type
 114    makes those easy to detect.  */
 115 typedef HOST_WIDEST_INT gcov_type;
 116
 117 /* Control flow edge information.  */
 118 struct edge_def GTY(())
 119 {
 120   /* The two blocks at the ends of the edge.  */
 121   struct basic_block_def *src;
 122   struct basic_block_def *dest;
 123
 124   /* Instructions queued on the edge.  */
 125   union edge_def_insns {
 126     rtx GTY ((tag ("0"))) r;
 127     tree GTY ((tag ("1"))) t;
 128   } GTY ((desc ("ir_type ()"))) insns;
 129
 130   /* Auxiliary info specific to a pass.  */
 131   PTR GTY ((skip (""))) aux;
 132
 133   /* Location of any goto implicit in the edge, during tree-ssa.  */
 134   source_locus goto_locus;
 135
 136   int flags;                    /* see EDGE_* below  */
 137   int probability;              /* biased by REG_BR_PROB_BASE */
 138   gcov_type count;              /* Expected number of executions calculated
 139                                    in profile.c  */
 140
 141   /* The index number corresponding to this edge in the edge vector
 142      dest->preds.  */
 143   unsigned int dest_idx;
 144 };
 145
 146 typedef struct edge_def *edge;
 147 DEF_VEC_P(edge);
 148 DEF_VEC_ALLOC_P(edge,gc);
 149
 150 #define EDGE_FALLTHRU           1       /* 'Straight line' flow */
 151 #define EDGE_ABNORMAL           2       /* Strange flow, like computed
 152                                            label, or eh */
 153 #define EDGE_ABNORMAL_CALL      4       /* Call with abnormal exit
 154                                            like an exception, or sibcall */
 155 #define EDGE_EH                 8       /* Exception throw */
 156 #define EDGE_FAKE               16      /* Not a real edge (profile.c) */
 157 #define EDGE_DFS_BACK           32      /* A backwards edge */
 158 #define EDGE_CAN_FALLTHRU       64      /* Candidate for straight line
 159                                            flow.  */
 160 #define EDGE_IRREDUCIBLE_LOOP   128     /* Part of irreducible loop.  */
 161 #define EDGE_SIBCALL            256     /* Edge from sibcall to exit.  */
 162 #define EDGE_LOOP_EXIT          512     /* Exit of a loop.  */
 163 #define EDGE_TRUE_VALUE         1024    /* Edge taken when controlling
 164                                            predicate is nonzero.  */
 165 #define EDGE_FALSE_VALUE        2048    /* Edge taken when controlling
 166                                            predicate is zero.  */
 167 #define EDGE_EXECUTABLE         4096    /* Edge is executable.  Only
 168                                            valid during SSA-CCP.  */
 169 #define EDGE_CROSSING           8192    /* Edge crosses between hot
 170                                            and cold sections, when we
 171                                            do partitioning.  */
 172 #define EDGE_ALL_FLAGS         16383
 173
 174 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 175
 176 /* Counter summary from the last set of coverage counts read by
 177    profile.c.  */
 178 extern const struct gcov_ctr_summary *profile_info;
 179
 180 /* Declared in cfgloop.h.  */
 181 struct loop;
 182 struct loops;
 183
 184 /* Declared in tree-flow.h.  */
 185 struct edge_prediction;
 186
 187 /* A basic block is a sequence of instructions with only entry and
 188    only one exit.  If any one of the instructions are executed, they
 189    will all be executed, and in sequence from first to last.
 190
 191    There may be COND_EXEC instructions in the basic block.  The
 192    COND_EXEC *instructions* will be executed -- but if the condition
 193    is false the conditionally executed *expressions* will of course
 194    not be executed.  We don't consider the conditionally executed
 195    expression (which might have side-effects) to be in a separate
 196    basic block because the program counter will always be at the same
 197    location after the COND_EXEC instruction, regardless of whether the
 198    condition is true or not.
 199
 200    Basic blocks need not start with a label nor end with a jump insn.
 201    For example, a previous basic block may just "conditionally fall"
 202    into the succeeding basic block, and the last basic block need not
 203    end with a jump insn.  Block 0 is a descendant of the entry block.
 204
 205    A basic block beginning with two labels cannot have notes between
 206    the labels.
 207
 208    Data for jump tables are stored in jump_insns that occur in no
 209    basic block even though these insns can follow or precede insns in
 210    basic blocks.  */
 211
 212 /* Basic block information indexed by block number.  */
 213 struct basic_block_def GTY((chain_next ("%h.next_bb"), chain_prev ("%h.prev_bb")))
 214 {
 215   /* The first and last insns of the block.  */
 216   rtx head_;
 217   rtx end_;
 218
 219   /* Pointers to the first and last trees of the block.  */
 220   tree stmt_list;
 221
 222   /* The edges into and out of the block.  */
 223   VEC(edge,gc) *preds;
 224   VEC(edge,gc) *succs;
 225
 226   /* The registers that are live on entry to this block.  */
 227   bitmap GTY ((skip (""))) global_live_at_start;
 228
 229   /* The registers that are live on exit from this block.  */
 230   bitmap GTY ((skip (""))) global_live_at_end;
 231
 232   /* Auxiliary info specific to a pass.  */
 233   PTR GTY ((skip (""))) aux;
 234
 235   /* Innermost loop containing the block.  */
 236   struct loop * GTY ((skip (""))) loop_father;
 237
 238   /* The dominance and postdominance information node.  */
 239   struct et_node * GTY ((skip (""))) dom[2];
 240
 241   /* Previous and next blocks in the chain.  */
 242   struct basic_block_def *prev_bb;
 243   struct basic_block_def *next_bb;
 244
 245   /* The data used by basic block copying and reordering functions.  */
 246   struct reorder_block_def * rbi;
 247
 248   /* Chain of PHI nodes for this block.  */
 249   tree phi_nodes;
 250
 251   /* A list of predictions.  */
 252   struct edge_prediction *predictions;
 253
 254   /* Expected number of executions: calculated in profile.c.  */
 255   gcov_type count;
 256
 257   /* The index of this block.  */
 258   int index;
 259
 260   /* The loop depth of this block.  */
 261   int loop_depth;
 262
 263   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 264   int frequency;
 265
 266   /* Various flags.  See BB_* below.  */
 267   int flags;
 268 };
 269
 270 typedef struct basic_block_def *basic_block;
 271
 272 /* Structure to hold information about the blocks during reordering and
 273    copying.  Needs to be put on a diet.  */
 274
 275 struct reorder_block_def GTY(())
 276 {
 277   rtx header;
 278   rtx footer;
 279
 280   basic_block next;
 281
 282   /* These pointers may be unreliable as the first is only used for
 283      debugging (and should probably be removed, and the second is only
 284      used by copying.  The basic blocks pointed to may be removed and
 285      that leaves these pointers pointing to garbage.  */
 286   basic_block GTY ((skip (""))) original;
 287   basic_block GTY ((skip (""))) copy;
 288
 289   int duplicated;
 290   int copy_number;
 291
 292   /* This field is used by the bb-reorder and tracer passes.  */
 293   int visited;
 294 };
 295
 296 typedef struct reorder_block_def *reorder_block_def;
 297
 298 #define BB_FREQ_MAX 10000
 299
 300 /* Masks for basic_block.flags.
 301
 302    BB_HOT_PARTITION and BB_COLD_PARTITION should be preserved throughout
 303    the compilation, so they are never cleared.
 304
 305    All other flags may be cleared by clear_bb_flags().  It is generally
 306    a bad idea to rely on any flags being up-to-date.  */
 307
 308 enum
 309 {
 310
 311   /* Set if insns in BB have are modified.  Used for updating liveness info.  */
 312   BB_DIRTY = 1,
 313
 314   /* Only set on blocks that have just been created by create_bb.  */
 315   BB_NEW = 2,
 316
 317   /* Set by find_unreachable_blocks.  Do not rely on this being set in any
 318      pass.  */
 319   BB_REACHABLE = 4,
 320
 321   /* Set for blocks in an irreducible loop by loop analysis.  */
 322   BB_IRREDUCIBLE_LOOP = 8,
 323
 324   /* Set on blocks that may actually not be single-entry single-exit block.  */
 325   BB_SUPERBLOCK = 16,
 326
 327   /* Set on basic blocks that the scheduler should not touch.  This is used
 328      by SMS to prevent other schedulers from messing with the loop schedule.  */
 329   BB_DISABLE_SCHEDULE = 32,
 330
 331   /* Set on blocks that should be put in a hot section.  */
 332   BB_HOT_PARTITION = 64,
 333
 334   /* Set on blocks that should be put in a cold section.  */
 335   BB_COLD_PARTITION = 128
 336 };
 337
 338 /* Dummy flag for convenience in the hot/cold partitioning code.  */
 339 #define BB_UNPARTITIONED        0
 340
 341 /* Partitions, to be used when partitioning hot and cold basic blocks into
 342    separate sections.  */
 343 #define BB_PARTITION(bb) ((bb)->flags & (BB_HOT_PARTITION|BB_COLD_PARTITION))
 344 #define BB_SET_PARTITION(bb, part) do {                                 \
 345   basic_block bb_ = (bb);                                               \
 346   bb_->flags = ((bb_->flags & ~(BB_HOT_PARTITION|BB_COLD_PARTITION))    \
 347                 | (part));                                              \
 348 } while (0)
 349
 350 #define BB_COPY_PARTITION(dstbb, srcbb) \
 351   BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb))
 352
 353 /* A structure to group all the per-function control flow graph data.
 354    The x_* prefixing is necessary because otherwise references to the
 355    fields of this struct are interpreted as the defines for backward
 356    source compatibility following the definition of this struct.  */
 357 struct control_flow_graph GTY(())
 358 {
 359   /* Block pointers for the exit and entry of a function.
 360      These are always the head and tail of the basic block list.  */
 361   basic_block x_entry_block_ptr;
 362   basic_block x_exit_block_ptr;
 363
 364   /* Index by basic block number, get basic block struct info.  */
 365   varray_type x_basic_block_info;
 366
 367   /* Number of basic blocks in this flow graph.  */
 368   int x_n_basic_blocks;
 369
 370   /* Number of edges in this flow graph.  */
 371   int x_n_edges;
 372
 373   /* The first free basic block number.  */
 374   int x_last_basic_block;
 375
 376   /* Mapping of labels to their associated blocks.  At present
 377      only used for the tree CFG.  */
 378   varray_type x_label_to_block_map;
 379
 380   enum profile_status {
 381     PROFILE_ABSENT,
 382     PROFILE_GUESSED,
 383     PROFILE_READ
 384   } x_profile_status;
 385 };
 386
 387 /* Defines for accessing the fields of the CFG structure for function FN.  */
 388 #define ENTRY_BLOCK_PTR_FOR_FUNCTION(FN)     ((FN)->cfg->x_entry_block_ptr)
 389 #define EXIT_BLOCK_PTR_FOR_FUNCTION(FN)      ((FN)->cfg->x_exit_block_ptr)
 390 #define basic_block_info_for_function(FN)    ((FN)->cfg->x_basic_block_info)
 391 #define n_basic_blocks_for_function(FN)      ((FN)->cfg->x_n_basic_blocks)
 392 #define n_edges_for_function(FN)             ((FN)->cfg->x_n_edges)
 393 #define last_basic_block_for_function(FN)    ((FN)->cfg->x_last_basic_block)
 394 #define label_to_block_map_for_function(FN)  ((FN)->cfg->x_label_to_block_map)
 395
 396 #define BASIC_BLOCK_FOR_FUNCTION(FN,N) \
 397   (VARRAY_BB (basic_block_info_for_function(FN), (N)))
 398
 399 /* Defines for textual backward source compatibility.  */
 400 #define ENTRY_BLOCK_PTR         (cfun->cfg->x_entry_block_ptr)
 401 #define EXIT_BLOCK_PTR          (cfun->cfg->x_exit_block_ptr)
 402 #define basic_block_info        (cfun->cfg->x_basic_block_info)
 403 #define n_basic_blocks          (cfun->cfg->x_n_basic_blocks)
 404 #define n_edges                 (cfun->cfg->x_n_edges)
 405 #define last_basic_block        (cfun->cfg->x_last_basic_block)
 406 #define label_to_block_map      (cfun->cfg->x_label_to_block_map)
 407 #define profile_status          (cfun->cfg->x_profile_status)
 408
 409 #define BASIC_BLOCK(N)          (VARRAY_BB (basic_block_info, (N)))
 410
 411 /* TRUE if we should re-run loop discovery after threading jumps, FALSE
 412    otherwise.  */
 413 extern bool rediscover_loops_after_threading;
 414
 415 /* For iterating over basic blocks.  */
 416 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 417   for (BB = FROM; BB != TO; BB = BB->DIR)
 418
 419 #define FOR_EACH_BB_FN(BB, FN) \
 420   FOR_BB_BETWEEN (BB, (FN)->cfg->x_entry_block_ptr->next_bb, (FN)->cfg->x_exit_block_ptr, next_bb)
 421
 422 #define FOR_EACH_BB(BB) FOR_EACH_BB_FN (BB, cfun)
 423
 424 #define FOR_EACH_BB_REVERSE_FN(BB, FN) \
 425   FOR_BB_BETWEEN (BB, (FN)->cfg->x_exit_block_ptr->prev_bb, (FN)->cfg->x_entry_block_ptr, prev_bb)
 426
 427 #define FOR_EACH_BB_REVERSE(BB) FOR_EACH_BB_REVERSE_FN(BB, cfun)
 428
 429 /* For iterating over insns in basic block.  */
 430 #define FOR_BB_INSNS(BB, INSN)                  \
 431   for ((INSN) = BB_HEAD (BB);                   \
 432        (INSN) != NEXT_INSN (BB_END (BB));       \
 433        (INSN) = NEXT_INSN (INSN))
 434
 435 #define FOR_BB_INSNS_REVERSE(BB, INSN)          \
 436   for ((INSN) = BB_END (BB);                    \
 437        (INSN) != PREV_INSN (BB_HEAD (BB));      \
 438        (INSN) = PREV_INSN (INSN))
 439
 440 /* Cycles through _all_ basic blocks, even the fake ones (entry and
 441    exit block).  */
 442
 443 #define FOR_ALL_BB(BB) \
 444   for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
 445
 446 #define FOR_ALL_BB_FN(BB, FN) \
 447   for (BB = ENTRY_BLOCK_PTR_FOR_FUNCTION (FN); BB; BB = BB->next_bb)
 448
 449 extern bitmap_obstack reg_obstack;
 450
 451 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 452    If the value is REG_BLOCK_GLOBAL (-2),
 453    it means (REG n) is used in more than one basic block.
 454    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 455    This information remains valid for the rest of the compilation
 456    of the current function; it is used to control register allocation.  */
 457
 458 #define REG_BLOCK_UNKNOWN -1
 459 #define REG_BLOCK_GLOBAL -2
 460
 461 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 462 \f
 463 /* Stuff for recording basic block info.  */
 464
 465 #define BB_HEAD(B)      (B)->head_
 466 #define BB_END(B)       (B)->end_
 467
 468 /* Special block numbers [markers] for entry and exit.  */
 469 #define ENTRY_BLOCK (-1)
 470 #define EXIT_BLOCK (-2)
 471
 472 /* Special block number not valid for any block.  */
 473 #define INVALID_BLOCK (-3)
 474
 475 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 476 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 477
 478 extern void compute_bb_for_insn (void);
 479 extern void free_bb_for_insn (void);
 480 extern void update_bb_for_insn (basic_block);
 481
 482 extern void free_basic_block_vars (void);
 483
 484 extern void insert_insn_on_edge (rtx, edge);
 485 bool safe_insert_insn_on_edge (rtx, edge);
 486
 487 extern void commit_edge_insertions (void);
 488 extern void commit_edge_insertions_watch_calls (void);
 489
 490 extern void remove_fake_edges (void);
 491 extern void remove_fake_exit_edges (void);
 492 extern void add_noreturn_fake_exit_edges (void);
 493 extern void connect_infinite_loops_to_exit (void);
 494 extern edge unchecked_make_edge (basic_block, basic_block, int);
 495 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int);
 496 extern edge make_edge (basic_block, basic_block, int);
 497 extern edge make_single_succ_edge (basic_block, basic_block, int);
 498 extern void remove_edge (edge);
 499 extern void redirect_edge_succ (edge, basic_block);
 500 extern edge redirect_edge_succ_nodup (edge, basic_block);
 501 extern void redirect_edge_pred (edge, basic_block);
 502 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
 503 extern void clear_bb_flags (void);
 504 extern void flow_reverse_top_sort_order_compute (int *);
 505 extern int flow_depth_first_order_compute (int *, int *);
 506 extern int dfs_enumerate_from (basic_block, int,
 507                                bool (*)(basic_block, void *),
 508                                basic_block *, int, void *);
 509 extern void compute_dominance_frontiers (bitmap *);
 510 extern void dump_edge_info (FILE *, edge, int);
 511 extern void brief_dump_cfg (FILE *);
 512 extern void clear_edges (void);
 513 extern rtx first_insn_after_basic_block_note (basic_block);
 514 extern void scale_bbs_frequencies_int (basic_block *, int, int, int);
 515 extern void scale_bbs_frequencies_gcov_type (basic_block *, int, gcov_type,
 516                                              gcov_type);
 517
 518 /* Structure to group all of the information to process IF-THEN and
 519    IF-THEN-ELSE blocks for the conditional execution support.  This
 520    needs to be in a public file in case the IFCVT macros call
 521    functions passing the ce_if_block data structure.  */
 522
 523 typedef struct ce_if_block
 524 {
 525   basic_block test_bb;                  /* First test block.  */
 526   basic_block then_bb;                  /* THEN block.  */
 527   basic_block else_bb;                  /* ELSE block or NULL.  */
 528   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 529   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 530   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 531   int num_and_and_blocks;               /* # of && blocks.  */
 532   int num_or_or_blocks;                 /* # of || blocks.  */
 533   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 534   int and_and_p;                        /* Complex test is &&.  */
 535   int num_then_insns;                   /* # of insns in THEN block.  */
 536   int num_else_insns;                   /* # of insns in ELSE block.  */
 537   int pass;                             /* Pass number.  */
 538
 539 #ifdef IFCVT_EXTRA_FIELDS
 540   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 541 #endif
 542
 543 } ce_if_block_t;
 544
 545 /* This structure maintains an edge list vector.  */
 546 struct edge_list
 547 {
 548   int num_blocks;
 549   int num_edges;
 550   edge *index_to_edge;
 551 };
 552
 553 /* The base value for branch probability notes and edge probabilities.  */
 554 #define REG_BR_PROB_BASE  10000
 555
 556 /* This is the value which indicates no edge is present.  */
 557 #define EDGE_INDEX_NO_EDGE      -1
 558
 559 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 560    if there is no edge between the 2 basic blocks.  */
 561 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 562
 563 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 564    block which is either the pred or succ end of the indexed edge.  */
 565 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 566 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 567
 568 /* INDEX_EDGE returns a pointer to the edge.  */
 569 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 570
 571 /* Number of edges in the compressed edge list.  */
 572 #define NUM_EDGES(el)                   ((el)->num_edges)
 573
 574 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 575 #define FALLTHRU_EDGE(bb)               (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 576                                          ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
 577
 578 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 579 #define BRANCH_EDGE(bb)                 (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 580                                          ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
 581
 582 /* Return expected execution frequency of the edge E.  */
 583 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 584                                           * (e)->probability \
 585                                           + REG_BR_PROB_BASE / 2) \
 586                                          / REG_BR_PROB_BASE)
 587
 588 /* Return nonzero if edge is critical.  */
 589 #define EDGE_CRITICAL_P(e)              (EDGE_COUNT ((e)->src->succs) >= 2 \
 590                                          && EDGE_COUNT ((e)->dest->preds) >= 2)
 591
 592 #define EDGE_COUNT(ev)                  VEC_length (edge, (ev))
 593 #define EDGE_I(ev,i)                    VEC_index  (edge, (ev), (i))
 594 #define EDGE_PRED(bb,i)                 VEC_index  (edge, (bb)->preds, (i))
 595 #define EDGE_SUCC(bb,i)                 VEC_index  (edge, (bb)->succs, (i))
 596
 597 /* Returns true if BB has precisely one successor.  */
 598
 599 static inline bool
 600 single_succ_p (basic_block bb)
 601 {
 602   return EDGE_COUNT (bb->succs) == 1;
 603 }
 604
 605 /* Returns true if BB has precisely one predecessor.  */
 606
 607 static inline bool
 608 single_pred_p (basic_block bb)
 609 {
 610   return EDGE_COUNT (bb->preds) == 1;
 611 }
 612
 613 /* Returns the single successor edge of basic block BB.  Aborts if
 614    BB does not have exactly one successor.  */
 615
 616 static inline edge
 617 single_succ_edge (basic_block bb)
 618 {
 619   gcc_assert (single_succ_p (bb));
 620   return EDGE_SUCC (bb, 0);
 621 }
 622
 623 /* Returns the single predecessor edge of basic block BB.  Aborts
 624    if BB does not have exactly one predecessor.  */
 625
 626 static inline edge
 627 single_pred_edge (basic_block bb)
 628 {
 629   gcc_assert (single_pred_p (bb));
 630   return EDGE_PRED (bb, 0);
 631 }
 632
 633 /* Returns the single successor block of basic block BB.  Aborts
 634    if BB does not have exactly one successor.  */
 635
 636 static inline basic_block
 637 single_succ (basic_block bb)
 638 {
 639   return single_succ_edge (bb)->dest;
 640 }
 641
 642 /* Returns the single predecessor block of basic block BB.  Aborts
 643    if BB does not have exactly one predecessor.*/
 644
 645 static inline basic_block
 646 single_pred (basic_block bb)
 647 {
 648   return single_pred_edge (bb)->src;
 649 }
 650
 651 /* Iterator object for edges.  */
 652
 653 typedef struct {
 654   unsigned index;
 655   VEC(edge,gc) **container;
 656 } edge_iterator;
 657
 658 static inline VEC(edge,gc) *
 659 ei_container (edge_iterator i)
 660 {
 661   gcc_assert (i.container);
 662   return *i.container;
 663 }
 664
 665 #define ei_start(iter) ei_start_1 (&(iter))
 666 #define ei_last(iter) ei_last_1 (&(iter))
 667
 668 /* Return an iterator pointing to the start of an edge vector.  */
 669 static inline edge_iterator
 670 ei_start_1 (VEC(edge,gc) **ev)
 671 {
 672   edge_iterator i;
 673
 674   i.index = 0;
 675   i.container = ev;
 676
 677   return i;
 678 }
 679
 680 /* Return an iterator pointing to the last element of an edge
 681    vector.  */
 682 static inline edge_iterator
 683 ei_last_1 (VEC(edge,gc) **ev)
 684 {
 685   edge_iterator i;
 686
 687   i.index = EDGE_COUNT (*ev) - 1;
 688   i.container = ev;
 689
 690   return i;
 691 }
 692
 693 /* Is the iterator `i' at the end of the sequence?  */
 694 static inline bool
 695 ei_end_p (edge_iterator i)
 696 {
 697   return (i.index == EDGE_COUNT (ei_container (i)));
 698 }
 699
 700 /* Is the iterator `i' at one position before the end of the
 701    sequence?  */
 702 static inline bool
 703 ei_one_before_end_p (edge_iterator i)
 704 {
 705   return (i.index + 1 == EDGE_COUNT (ei_container (i)));
 706 }
 707
 708 /* Advance the iterator to the next element.  */
 709 static inline void
 710 ei_next (edge_iterator *i)
 711 {
 712   gcc_assert (i->index < EDGE_COUNT (ei_container (*i)));
 713   i->index++;
 714 }
 715
 716 /* Move the iterator to the previous element.  */
 717 static inline void
 718 ei_prev (edge_iterator *i)
 719 {
 720   gcc_assert (i->index > 0);
 721   i->index--;
 722 }
 723
 724 /* Return the edge pointed to by the iterator `i'.  */
 725 static inline edge
 726 ei_edge (edge_iterator i)
 727 {
 728   return EDGE_I (ei_container (i), i.index);
 729 }
 730
 731 /* Return an edge pointed to by the iterator.  Do it safely so that
 732    NULL is returned when the iterator is pointing at the end of the
 733    sequence.  */
 734 static inline edge
 735 ei_safe_edge (edge_iterator i)
 736 {
 737   return !ei_end_p (i) ? ei_edge (i) : NULL;
 738 }
 739
 740 /* Return 1 if we should continue to iterate.  Return 0 otherwise.
 741    *Edge P is set to the next edge if we are to continue to iterate
 742    and NULL otherwise.  */
 743
 744 static inline bool
 745 ei_cond (edge_iterator ei, edge *p)
 746 {
 747   if (!ei_end_p (ei))
 748     {
 749       *p = ei_edge (ei);
 750       return 1;
 751     }
 752   else
 753     {
 754       *p = NULL;
 755       return 0;
 756     }
 757 }
 758
 759 /* This macro serves as a convenient way to iterate each edge in a
 760    vector of predecessor or successor edges.  It must not be used when
 761    an element might be removed during the traversal, otherwise
 762    elements will be missed.  Instead, use a for-loop like that shown
 763    in the following pseudo-code:
 764
 765    FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 766      {
 767         IF (e != taken_edge)
 768           remove_edge (e);
 769         ELSE
 770           ei_next (&ei);
 771      }
 772 */
 773
 774 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC)       \
 775   for ((ITER) = ei_start ((EDGE_VEC));          \
 776        ei_cond ((ITER), &(EDGE));               \
 777        ei_next (&(ITER)))
 778
 779 struct edge_list * create_edge_list (void);
 780 void free_edge_list (struct edge_list *);
 781 void print_edge_list (FILE *, struct edge_list *);
 782 void verify_edge_list (FILE *, struct edge_list *);
 783 int find_edge_index (struct edge_list *, basic_block, basic_block);
 784 edge find_edge (basic_block, basic_block);
 785
 786
 787 enum update_life_extent
 788 {
 789   UPDATE_LIFE_LOCAL = 0,
 790   UPDATE_LIFE_GLOBAL = 1,
 791   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 792 };
 793
 794 /* Flags for life_analysis and update_life_info.  */
 795
 796 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 797 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 798 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 799 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 800 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 801 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 802                                            by dead code removal.  */
 803 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 804 #define PROP_SCAN_DEAD_STORES   128     /* Scan for dead code.  */
 805 #define PROP_ASM_SCAN           256     /* Internal flag used within flow.c
 806                                            to flag analysis of asms.  */
 807 #define PROP_DEAD_INSN          1024    /* Internal flag used within flow.c
 808                                            to flag analysis of dead insn.  */
 809 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 810                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 811                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 812                                  | PROP_ALLOW_CFG_CHANGES \
 813                                  | PROP_SCAN_DEAD_STORES)
 814 #define PROP_POSTRELOAD         (PROP_DEATH_NOTES  \
 815                                  | PROP_KILL_DEAD_CODE  \
 816                                  | PROP_SCAN_DEAD_CODE \
 817                                  | PROP_SCAN_DEAD_STORES)
 818
 819 #define CLEANUP_EXPENSIVE       1       /* Do relatively expensive optimizations
 820                                            except for edge forwarding */
 821 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 822 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 823                                            to care REG_DEAD notes.  */
 824 #define CLEANUP_PRE_LOOP        8       /* Take care to preserve syntactic loop
 825                                            notes.  */
 826 #define CLEANUP_UPDATE_LIFE     16      /* Keep life information up to date.  */
 827 #define CLEANUP_THREADING       32      /* Do jump threading.  */
 828 #define CLEANUP_NO_INSN_DEL     64      /* Do not try to delete trivially dead
 829                                            insns.  */
 830 #define CLEANUP_CFGLAYOUT       128     /* Do cleanup in cfglayout mode.  */
 831 #define CLEANUP_LOG_LINKS       256     /* Update log links.  */
 832
 833 extern void life_analysis (FILE *, int);
 834 extern int update_life_info (sbitmap, enum update_life_extent, int);
 835 extern int update_life_info_in_dirty_blocks (enum update_life_extent, int);
 836 extern int count_or_remove_death_notes (sbitmap, int);
 837 extern int propagate_block (basic_block, regset, regset, regset, int);
 838
 839 struct propagate_block_info;
 840 extern rtx propagate_one_insn (struct propagate_block_info *, rtx);
 841 extern struct propagate_block_info *init_propagate_block_info
 842  (basic_block, regset, regset, regset, int);
 843 extern void free_propagate_block_info (struct propagate_block_info *);
 844
 845 /* In lcm.c */
 846 extern struct edge_list *pre_edge_lcm (FILE *, int, sbitmap *, sbitmap *,
 847                                        sbitmap *, sbitmap *, sbitmap **,
 848                                        sbitmap **);
 849 extern struct edge_list *pre_edge_rev_lcm (FILE *, int, sbitmap *,
 850                                            sbitmap *, sbitmap *,
 851                                            sbitmap *, sbitmap **,
 852                                            sbitmap **);
 853 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
 854 extern int optimize_mode_switching (FILE *);
 855
 856 /* In predict.c */
 857 extern void estimate_probability (struct loops *);
 858 extern void expected_value_to_br_prob (void);
 859 extern bool maybe_hot_bb_p (basic_block);
 860 extern bool probably_cold_bb_p (basic_block);
 861 extern bool probably_never_executed_bb_p (basic_block);
 862 extern bool tree_predicted_by_p (basic_block, enum br_predictor);
 863 extern bool rtl_predicted_by_p (basic_block, enum br_predictor);
 864 extern void tree_predict_edge (edge, enum br_predictor, int);
 865 extern void rtl_predict_edge (edge, enum br_predictor, int);
 866 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
 867 extern void guess_outgoing_edge_probabilities (basic_block);
 868 extern void remove_predictions_associated_with_edge (edge);
 869
 870 /* In flow.c */
 871 extern void init_flow (void);
 872 extern void debug_bb (basic_block);
 873 extern basic_block debug_bb_n (int);
 874 extern void dump_regset (regset, FILE *);
 875 extern void debug_regset (regset);
 876 extern void allocate_reg_life_data (void);
 877 extern void expunge_block (basic_block);
 878 extern void link_block (basic_block, basic_block);
 879 extern void unlink_block (basic_block);
 880 extern void compact_blocks (void);
 881 extern basic_block alloc_block (void);
 882 extern void find_unreachable_blocks (void);
 883 extern int delete_noop_moves (void);
 884 extern basic_block force_nonfallthru (edge);
 885 extern rtx block_label (basic_block);
 886 extern bool forwarder_block_p (basic_block);
 887 extern bool purge_all_dead_edges (void);
 888 extern bool purge_dead_edges (basic_block);
 889 extern void find_many_sub_basic_blocks (sbitmap);
 890 extern void rtl_make_eh_edge (sbitmap, basic_block, rtx);
 891 extern bool can_fallthru (basic_block, basic_block);
 892 extern bool could_fall_through (basic_block, basic_block);
 893 extern void flow_nodes_print (const char *, const sbitmap, FILE *);
 894 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
 895 extern void alloc_aux_for_block (basic_block, int);
 896 extern void alloc_aux_for_blocks (int);
 897 extern void clear_aux_for_blocks (void);
 898 extern void free_aux_for_blocks (void);
 899 extern void alloc_aux_for_edge (edge, int);
 900 extern void alloc_aux_for_edges (int);
 901 extern void clear_aux_for_edges (void);
 902 extern void free_aux_for_edges (void);
 903 extern void find_basic_blocks (rtx);
 904 extern bool cleanup_cfg (int);
 905 extern bool delete_unreachable_blocks (void);
 906 extern bool merge_seq_blocks (void);
 907
 908 typedef struct conflict_graph_def *conflict_graph;
 909
 910 /* Callback function when enumerating conflicts.  The arguments are
 911    the smaller and larger regno in the conflict.  Returns zero if
 912    enumeration is to continue, nonzero to halt enumeration.  */
 913 typedef int (*conflict_graph_enum_fn) (int, int, void *);
 914
 915
 916 /* Prototypes of operations on conflict graphs.  */
 917
 918 extern conflict_graph conflict_graph_new
 919  (int);
 920 extern void conflict_graph_delete (conflict_graph);
 921 extern int conflict_graph_add (conflict_graph, int, int);
 922 extern int conflict_graph_conflict_p (conflict_graph, int, int);
 923 extern void conflict_graph_enum (conflict_graph, int, conflict_graph_enum_fn,
 924                                  void *);
 925 extern void conflict_graph_merge_regs (conflict_graph, int, int);
 926 extern void conflict_graph_print (conflict_graph, FILE*);
 927 extern bool mark_dfs_back_edges (void);
 928 extern void set_edge_can_fallthru_flag (void);
 929 extern void update_br_prob_note (basic_block);
 930 extern void fixup_abnormal_edges (void);
 931 extern bool inside_basic_block_p (rtx);
 932 extern bool control_flow_insn_p (rtx);
 933
 934 /* In bb-reorder.c */
 935 extern void reorder_basic_blocks (unsigned int);
 936 extern void duplicate_computed_gotos (void);
 937 extern void partition_hot_cold_basic_blocks (void);
 938
 939 /* In cfg.c */
 940 extern void initialize_bb_rbi (basic_block bb);
 941
 942 /* In dominance.c */
 943
 944 enum cdi_direction
 945 {
 946   CDI_DOMINATORS,
 947   CDI_POST_DOMINATORS
 948 };
 949
 950 enum dom_state
 951 {
 952   DOM_NONE,             /* Not computed at all.  */
 953   DOM_NO_FAST_QUERY,    /* The data is OK, but the fast query data are not usable.  */
 954   DOM_OK                /* Everything is ok.  */
 955 };
 956
 957 extern enum dom_state dom_computed[2];
 958
 959 extern bool dom_info_available_p (enum cdi_direction);
 960 extern void calculate_dominance_info (enum cdi_direction);
 961 extern void free_dominance_info (enum cdi_direction);
 962 extern basic_block nearest_common_dominator (enum cdi_direction,
 963                                              basic_block, basic_block);
 964 extern basic_block nearest_common_dominator_for_set (enum cdi_direction,
 965                                                      bitmap);
 966 extern void set_immediate_dominator (enum cdi_direction, basic_block,
 967                                      basic_block);
 968 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
 969 extern bool dominated_by_p (enum cdi_direction, basic_block, basic_block);
 970 extern int get_dominated_by (enum cdi_direction, basic_block, basic_block **);
 971 extern unsigned get_dominated_by_region (enum cdi_direction, basic_block *,
 972                                          unsigned, basic_block *);
 973 extern void add_to_dominance_info (enum cdi_direction, basic_block);
 974 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
 975 basic_block recount_dominator (enum cdi_direction, basic_block);
 976 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
 977                                            basic_block);
 978 extern void iterate_fix_dominators (enum cdi_direction, basic_block *, int);
 979 extern void verify_dominators (enum cdi_direction);
 980 extern basic_block first_dom_son (enum cdi_direction, basic_block);
 981 extern basic_block next_dom_son (enum cdi_direction, basic_block);
 982 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
 983 extern void break_superblocks (void);
 984 extern void check_bb_profile (basic_block, FILE *);
 985 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
 986
 987 #include "cfghooks.h"
 988
 989 #endif /* GCC_BASIC_BLOCK_H */