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