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 /* Special labels found during CFG build.  */
 450
 451 extern GTY(()) rtx label_value_list;
 452
 453 extern bitmap_obstack reg_obstack;
 454
 455 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 456    If the value is REG_BLOCK_GLOBAL (-2),
 457    it means (REG n) is used in more than one basic block.
 458    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 459    This information remains valid for the rest of the compilation
 460    of the current function; it is used to control register allocation.  */
 461
 462 #define REG_BLOCK_UNKNOWN -1
 463 #define REG_BLOCK_GLOBAL -2
 464
 465 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 466 \f
 467 /* Stuff for recording basic block info.  */
 468
 469 #define BB_HEAD(B)      (B)->head_
 470 #define BB_END(B)       (B)->end_
 471
 472 /* Special block numbers [markers] for entry and exit.  */
 473 #define ENTRY_BLOCK (-1)
 474 #define EXIT_BLOCK (-2)
 475
 476 /* Special block number not valid for any block.  */
 477 #define INVALID_BLOCK (-3)
 478
 479 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 480 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 481
 482 extern void compute_bb_for_insn (void);
 483 extern void free_bb_for_insn (void);
 484 extern void update_bb_for_insn (basic_block);
 485
 486 extern void free_basic_block_vars (void);
 487
 488 extern void insert_insn_on_edge (rtx, edge);
 489 bool safe_insert_insn_on_edge (rtx, edge);
 490
 491 extern void commit_edge_insertions (void);
 492 extern void commit_edge_insertions_watch_calls (void);
 493
 494 extern void remove_fake_edges (void);
 495 extern void remove_fake_exit_edges (void);
 496 extern void add_noreturn_fake_exit_edges (void);
 497 extern void connect_infinite_loops_to_exit (void);
 498 extern edge unchecked_make_edge (basic_block, basic_block, int);
 499 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int);
 500 extern edge make_edge (basic_block, basic_block, int);
 501 extern edge make_single_succ_edge (basic_block, basic_block, int);
 502 extern void remove_edge (edge);
 503 extern void redirect_edge_succ (edge, basic_block);
 504 extern edge redirect_edge_succ_nodup (edge, basic_block);
 505 extern void redirect_edge_pred (edge, basic_block);
 506 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
 507 extern void clear_bb_flags (void);
 508 extern void flow_reverse_top_sort_order_compute (int *);
 509 extern int flow_depth_first_order_compute (int *, int *);
 510 extern int dfs_enumerate_from (basic_block, int,
 511                                bool (*)(basic_block, void *),
 512                                basic_block *, int, void *);
 513 extern void compute_dominance_frontiers (bitmap *);
 514 extern void dump_edge_info (FILE *, edge, int);
 515 extern void brief_dump_cfg (FILE *);
 516 extern void clear_edges (void);
 517 extern rtx first_insn_after_basic_block_note (basic_block);
 518 extern void scale_bbs_frequencies_int (basic_block *, int, int, int);
 519 extern void scale_bbs_frequencies_gcov_type (basic_block *, int, gcov_type,
 520                                              gcov_type);
 521
 522 /* Structure to group all of the information to process IF-THEN and
 523    IF-THEN-ELSE blocks for the conditional execution support.  This
 524    needs to be in a public file in case the IFCVT macros call
 525    functions passing the ce_if_block data structure.  */
 526
 527 typedef struct ce_if_block
 528 {
 529   basic_block test_bb;                  /* First test block.  */
 530   basic_block then_bb;                  /* THEN block.  */
 531   basic_block else_bb;                  /* ELSE block or NULL.  */
 532   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 533   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 534   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 535   int num_and_and_blocks;               /* # of && blocks.  */
 536   int num_or_or_blocks;                 /* # of || blocks.  */
 537   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 538   int and_and_p;                        /* Complex test is &&.  */
 539   int num_then_insns;                   /* # of insns in THEN block.  */
 540   int num_else_insns;                   /* # of insns in ELSE block.  */
 541   int pass;                             /* Pass number.  */
 542
 543 #ifdef IFCVT_EXTRA_FIELDS
 544   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 545 #endif
 546
 547 } ce_if_block_t;
 548
 549 /* This structure maintains an edge list vector.  */
 550 struct edge_list
 551 {
 552   int num_blocks;
 553   int num_edges;
 554   edge *index_to_edge;
 555 };
 556
 557 /* The base value for branch probability notes and edge probabilities.  */
 558 #define REG_BR_PROB_BASE  10000
 559
 560 /* This is the value which indicates no edge is present.  */
 561 #define EDGE_INDEX_NO_EDGE      -1
 562
 563 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 564    if there is no edge between the 2 basic blocks.  */
 565 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 566
 567 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 568    block which is either the pred or succ end of the indexed edge.  */
 569 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 570 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 571
 572 /* INDEX_EDGE returns a pointer to the edge.  */
 573 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 574
 575 /* Number of edges in the compressed edge list.  */
 576 #define NUM_EDGES(el)                   ((el)->num_edges)
 577
 578 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 579 #define FALLTHRU_EDGE(bb)               (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 580                                          ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
 581
 582 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 583 #define BRANCH_EDGE(bb)                 (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 584                                          ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
 585
 586 /* Return expected execution frequency of the edge E.  */
 587 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 588                                           * (e)->probability \
 589                                           + REG_BR_PROB_BASE / 2) \
 590                                          / REG_BR_PROB_BASE)
 591
 592 /* Return nonzero if edge is critical.  */
 593 #define EDGE_CRITICAL_P(e)              (EDGE_COUNT ((e)->src->succs) >= 2 \
 594                                          && EDGE_COUNT ((e)->dest->preds) >= 2)
 595
 596 #define EDGE_COUNT(ev)                  VEC_length (edge, (ev))
 597 #define EDGE_I(ev,i)                    VEC_index  (edge, (ev), (i))
 598 #define EDGE_PRED(bb,i)                 VEC_index  (edge, (bb)->preds, (i))
 599 #define EDGE_SUCC(bb,i)                 VEC_index  (edge, (bb)->succs, (i))
 600
 601 /* Returns true if BB has precisely one successor.  */
 602
 603 static inline bool
 604 single_succ_p (basic_block bb)
 605 {
 606   return EDGE_COUNT (bb->succs) == 1;
 607 }
 608
 609 /* Returns true if BB has precisely one predecessor.  */
 610
 611 static inline bool
 612 single_pred_p (basic_block bb)
 613 {
 614   return EDGE_COUNT (bb->preds) == 1;
 615 }
 616
 617 /* Returns the single successor edge of basic block BB.  Aborts if
 618    BB does not have exactly one successor.  */
 619
 620 static inline edge
 621 single_succ_edge (basic_block bb)
 622 {
 623   gcc_assert (single_succ_p (bb));
 624   return EDGE_SUCC (bb, 0);
 625 }
 626
 627 /* Returns the single predecessor edge of basic block BB.  Aborts
 628    if BB does not have exactly one predecessor.  */
 629
 630 static inline edge
 631 single_pred_edge (basic_block bb)
 632 {
 633   gcc_assert (single_pred_p (bb));
 634   return EDGE_PRED (bb, 0);
 635 }
 636
 637 /* Returns the single successor block of basic block BB.  Aborts
 638    if BB does not have exactly one successor.  */
 639
 640 static inline basic_block
 641 single_succ (basic_block bb)
 642 {
 643   return single_succ_edge (bb)->dest;
 644 }
 645
 646 /* Returns the single predecessor block of basic block BB.  Aborts
 647    if BB does not have exactly one predecessor.*/
 648
 649 static inline basic_block
 650 single_pred (basic_block bb)
 651 {
 652   return single_pred_edge (bb)->src;
 653 }
 654
 655 /* Iterator object for edges.  */
 656
 657 typedef struct {
 658   unsigned index;
 659   VEC(edge,gc) **container;
 660 } edge_iterator;
 661
 662 static inline VEC(edge,gc) *
 663 ei_container (edge_iterator i)
 664 {
 665   gcc_assert (i.container);
 666   return *i.container;
 667 }
 668
 669 #define ei_start(iter) ei_start_1 (&(iter))
 670 #define ei_last(iter) ei_last_1 (&(iter))
 671
 672 /* Return an iterator pointing to the start of an edge vector.  */
 673 static inline edge_iterator
 674 ei_start_1 (VEC(edge,gc) **ev)
 675 {
 676   edge_iterator i;
 677
 678   i.index = 0;
 679   i.container = ev;
 680
 681   return i;
 682 }
 683
 684 /* Return an iterator pointing to the last element of an edge
 685    vector.  */
 686 static inline edge_iterator
 687 ei_last_1 (VEC(edge,gc) **ev)
 688 {
 689   edge_iterator i;
 690
 691   i.index = EDGE_COUNT (*ev) - 1;
 692   i.container = ev;
 693
 694   return i;
 695 }
 696
 697 /* Is the iterator `i' at the end of the sequence?  */
 698 static inline bool
 699 ei_end_p (edge_iterator i)
 700 {
 701   return (i.index == EDGE_COUNT (ei_container (i)));
 702 }
 703
 704 /* Is the iterator `i' at one position before the end of the
 705    sequence?  */
 706 static inline bool
 707 ei_one_before_end_p (edge_iterator i)
 708 {
 709   return (i.index + 1 == EDGE_COUNT (ei_container (i)));
 710 }
 711
 712 /* Advance the iterator to the next element.  */
 713 static inline void
 714 ei_next (edge_iterator *i)
 715 {
 716   gcc_assert (i->index < EDGE_COUNT (ei_container (*i)));
 717   i->index++;
 718 }
 719
 720 /* Move the iterator to the previous element.  */
 721 static inline void
 722 ei_prev (edge_iterator *i)
 723 {
 724   gcc_assert (i->index > 0);
 725   i->index--;
 726 }
 727
 728 /* Return the edge pointed to by the iterator `i'.  */
 729 static inline edge
 730 ei_edge (edge_iterator i)
 731 {
 732   return EDGE_I (ei_container (i), i.index);
 733 }
 734
 735 /* Return an edge pointed to by the iterator.  Do it safely so that
 736    NULL is returned when the iterator is pointing at the end of the
 737    sequence.  */
 738 static inline edge
 739 ei_safe_edge (edge_iterator i)
 740 {
 741   return !ei_end_p (i) ? ei_edge (i) : NULL;
 742 }
 743
 744 /* Return 1 if we should continue to iterate.  Return 0 otherwise.
 745    *Edge P is set to the next edge if we are to continue to iterate
 746    and NULL otherwise.  */
 747
 748 static inline bool
 749 ei_cond (edge_iterator ei, edge *p)
 750 {
 751   if (!ei_end_p (ei))
 752     {
 753       *p = ei_edge (ei);
 754       return 1;
 755     }
 756   else
 757     {
 758       *p = NULL;
 759       return 0;
 760     }
 761 }
 762
 763 /* This macro serves as a convenient way to iterate each edge in a
 764    vector of predecessor or successor edges.  It must not be used when
 765    an element might be removed during the traversal, otherwise
 766    elements will be missed.  Instead, use a for-loop like that shown
 767    in the following pseudo-code:
 768
 769    FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 770      {
 771         IF (e != taken_edge)
 772           remove_edge (e);
 773         ELSE
 774           ei_next (&ei);
 775      }
 776 */
 777
 778 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC)       \
 779   for ((ITER) = ei_start ((EDGE_VEC));          \
 780        ei_cond ((ITER), &(EDGE));               \
 781        ei_next (&(ITER)))
 782
 783 struct edge_list * create_edge_list (void);
 784 void free_edge_list (struct edge_list *);
 785 void print_edge_list (FILE *, struct edge_list *);
 786 void verify_edge_list (FILE *, struct edge_list *);
 787 int find_edge_index (struct edge_list *, basic_block, basic_block);
 788 edge find_edge (basic_block, basic_block);
 789
 790
 791 enum update_life_extent
 792 {
 793   UPDATE_LIFE_LOCAL = 0,
 794   UPDATE_LIFE_GLOBAL = 1,
 795   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 796 };
 797
 798 /* Flags for life_analysis and update_life_info.  */
 799
 800 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 801 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 802 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 803 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 804 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 805 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 806                                            by dead code removal.  */
 807 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 808 #define PROP_SCAN_DEAD_STORES   128     /* Scan for dead code.  */
 809 #define PROP_ASM_SCAN           256     /* Internal flag used within flow.c
 810                                            to flag analysis of asms.  */
 811 #define PROP_DEAD_INSN          1024    /* Internal flag used within flow.c
 812                                            to flag analysis of dead insn.  */
 813 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 814                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 815                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 816                                  | PROP_ALLOW_CFG_CHANGES \
 817                                  | PROP_SCAN_DEAD_STORES)
 818 #define PROP_POSTRELOAD         (PROP_DEATH_NOTES  \
 819                                  | PROP_KILL_DEAD_CODE  \
 820                                  | PROP_SCAN_DEAD_CODE \
 821                                  | PROP_SCAN_DEAD_STORES)
 822
 823 #define CLEANUP_EXPENSIVE       1       /* Do relatively expensive optimizations
 824                                            except for edge forwarding */
 825 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 826 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 827                                            to care REG_DEAD notes.  */
 828 #define CLEANUP_PRE_LOOP        8       /* Take care to preserve syntactic loop
 829                                            notes.  */
 830 #define CLEANUP_UPDATE_LIFE     16      /* Keep life information up to date.  */
 831 #define CLEANUP_THREADING       32      /* Do jump threading.  */
 832 #define CLEANUP_NO_INSN_DEL     64      /* Do not try to delete trivially dead
 833                                            insns.  */
 834 #define CLEANUP_CFGLAYOUT       128     /* Do cleanup in cfglayout mode.  */
 835 #define CLEANUP_LOG_LINKS       256     /* Update log links.  */
 836
 837 extern void life_analysis (FILE *, int);
 838 extern int update_life_info (sbitmap, enum update_life_extent, int);
 839 extern int update_life_info_in_dirty_blocks (enum update_life_extent, int);
 840 extern int count_or_remove_death_notes (sbitmap, int);
 841 extern int propagate_block (basic_block, regset, regset, regset, int);
 842
 843 struct propagate_block_info;
 844 extern rtx propagate_one_insn (struct propagate_block_info *, rtx);
 845 extern struct propagate_block_info *init_propagate_block_info
 846  (basic_block, regset, regset, regset, int);
 847 extern void free_propagate_block_info (struct propagate_block_info *);
 848
 849 /* In lcm.c */
 850 extern struct edge_list *pre_edge_lcm (FILE *, int, sbitmap *, sbitmap *,
 851                                        sbitmap *, sbitmap *, sbitmap **,
 852                                        sbitmap **);
 853 extern struct edge_list *pre_edge_rev_lcm (FILE *, int, sbitmap *,
 854                                            sbitmap *, sbitmap *,
 855                                            sbitmap *, sbitmap **,
 856                                            sbitmap **);
 857 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
 858 extern int optimize_mode_switching (FILE *);
 859
 860 /* In predict.c */
 861 extern void estimate_probability (struct loops *);
 862 extern void expected_value_to_br_prob (void);
 863 extern bool maybe_hot_bb_p (basic_block);
 864 extern bool probably_cold_bb_p (basic_block);
 865 extern bool probably_never_executed_bb_p (basic_block);
 866 extern bool tree_predicted_by_p (basic_block, enum br_predictor);
 867 extern bool rtl_predicted_by_p (basic_block, enum br_predictor);
 868 extern void tree_predict_edge (edge, enum br_predictor, int);
 869 extern void rtl_predict_edge (edge, enum br_predictor, int);
 870 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
 871 extern void guess_outgoing_edge_probabilities (basic_block);
 872
 873 /* In flow.c */
 874 extern void init_flow (void);
 875 extern void debug_bb (basic_block);
 876 extern basic_block debug_bb_n (int);
 877 extern void dump_regset (regset, FILE *);
 878 extern void debug_regset (regset);
 879 extern void allocate_reg_life_data (void);
 880 extern void expunge_block (basic_block);
 881 extern void link_block (basic_block, basic_block);
 882 extern void unlink_block (basic_block);
 883 extern void compact_blocks (void);
 884 extern basic_block alloc_block (void);
 885 extern void find_unreachable_blocks (void);
 886 extern int delete_noop_moves (void);
 887 extern basic_block force_nonfallthru (edge);
 888 extern rtx block_label (basic_block);
 889 extern bool forwarder_block_p (basic_block);
 890 extern bool purge_all_dead_edges (void);
 891 extern bool purge_dead_edges (basic_block);
 892 extern void find_many_sub_basic_blocks (sbitmap);
 893 extern void rtl_make_eh_edge (sbitmap, basic_block, rtx);
 894 extern bool can_fallthru (basic_block, basic_block);
 895 extern bool could_fall_through (basic_block, basic_block);
 896 extern void flow_nodes_print (const char *, const sbitmap, FILE *);
 897 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
 898 extern void alloc_aux_for_block (basic_block, int);
 899 extern void alloc_aux_for_blocks (int);
 900 extern void clear_aux_for_blocks (void);
 901 extern void free_aux_for_blocks (void);
 902 extern void alloc_aux_for_edge (edge, int);
 903 extern void alloc_aux_for_edges (int);
 904 extern void clear_aux_for_edges (void);
 905 extern void free_aux_for_edges (void);
 906 extern void find_basic_blocks (rtx);
 907 extern bool cleanup_cfg (int);
 908 extern bool delete_unreachable_blocks (void);
 909 extern bool merge_seq_blocks (void);
 910
 911 typedef struct conflict_graph_def *conflict_graph;
 912
 913 /* Callback function when enumerating conflicts.  The arguments are
 914    the smaller and larger regno in the conflict.  Returns zero if
 915    enumeration is to continue, nonzero to halt enumeration.  */
 916 typedef int (*conflict_graph_enum_fn) (int, int, void *);
 917
 918
 919 /* Prototypes of operations on conflict graphs.  */
 920
 921 extern conflict_graph conflict_graph_new
 922  (int);
 923 extern void conflict_graph_delete (conflict_graph);
 924 extern int conflict_graph_add (conflict_graph, int, int);
 925 extern int conflict_graph_conflict_p (conflict_graph, int, int);
 926 extern void conflict_graph_enum (conflict_graph, int, conflict_graph_enum_fn,
 927                                  void *);
 928 extern void conflict_graph_merge_regs (conflict_graph, int, int);
 929 extern void conflict_graph_print (conflict_graph, FILE*);
 930 extern bool mark_dfs_back_edges (void);
 931 extern void set_edge_can_fallthru_flag (void);
 932 extern void update_br_prob_note (basic_block);
 933 extern void fixup_abnormal_edges (void);
 934 extern bool inside_basic_block_p (rtx);
 935 extern bool control_flow_insn_p (rtx);
 936
 937 /* In bb-reorder.c */
 938 extern void reorder_basic_blocks (unsigned int);
 939 extern void duplicate_computed_gotos (void);
 940 extern void partition_hot_cold_basic_blocks (void);
 941
 942 /* In cfg.c */
 943 extern void initialize_bb_rbi (basic_block bb);
 944
 945 /* In dominance.c */
 946
 947 enum cdi_direction
 948 {
 949   CDI_DOMINATORS,
 950   CDI_POST_DOMINATORS
 951 };
 952
 953 enum dom_state
 954 {
 955   DOM_NONE,             /* Not computed at all.  */
 956   DOM_NO_FAST_QUERY,    /* The data is OK, but the fast query data are not usable.  */
 957   DOM_OK                /* Everything is ok.  */
 958 };
 959
 960 extern enum dom_state dom_computed[2];
 961
 962 extern bool dom_info_available_p (enum cdi_direction);
 963 extern void calculate_dominance_info (enum cdi_direction);
 964 extern void free_dominance_info (enum cdi_direction);
 965 extern basic_block nearest_common_dominator (enum cdi_direction,
 966                                              basic_block, basic_block);
 967 extern basic_block nearest_common_dominator_for_set (enum cdi_direction,
 968                                                      bitmap);
 969 extern void set_immediate_dominator (enum cdi_direction, basic_block,
 970                                      basic_block);
 971 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
 972 extern bool dominated_by_p (enum cdi_direction, basic_block, basic_block);
 973 extern int get_dominated_by (enum cdi_direction, basic_block, basic_block **);
 974 extern unsigned get_dominated_by_region (enum cdi_direction, basic_block *,
 975                                          unsigned, basic_block *);
 976 extern void add_to_dominance_info (enum cdi_direction, basic_block);
 977 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
 978 basic_block recount_dominator (enum cdi_direction, basic_block);
 979 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
 980                                            basic_block);
 981 extern void iterate_fix_dominators (enum cdi_direction, basic_block *, int);
 982 extern void verify_dominators (enum cdi_direction);
 983 extern basic_block first_dom_son (enum cdi_direction, basic_block);
 984 extern basic_block next_dom_son (enum cdi_direction, basic_block);
 985 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
 986 extern void break_superblocks (void);
 987 extern void check_bb_profile (basic_block, FILE *);
 988 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
 989
 990 #include "cfghooks.h"
 991
 992 #endif /* GCC_BASIC_BLOCK_H */