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   /* Which section block belongs in, when partitioning basic blocks.  */
 270   int partition;
 271 };
 272
 273 typedef struct basic_block_def *basic_block;
 274
 275 /* Structure to hold information about the blocks during reordering and
 276    copying.  Needs to be put on a diet.  */
 277
 278 struct reorder_block_def GTY(())
 279 {
 280   rtx header;
 281   rtx footer;
 282
 283   basic_block next;
 284
 285   /* These pointers may be unreliable as the first is only used for
 286      debugging (and should probably be removed, and the second is only
 287      used by copying.  The basic blocks pointed to may be removed and
 288      that leaves these pointers pointing to garbage.  */
 289   basic_block GTY ((skip (""))) original;
 290   basic_block GTY ((skip (""))) copy;
 291
 292   int duplicated;
 293   int copy_number;
 294
 295   /* This field is used by the bb-reorder and tracer passes.  */
 296   int visited;
 297 };
 298
 299 typedef struct reorder_block_def *reorder_block_def;
 300
 301 #define BB_FREQ_MAX 10000
 302
 303 /* Masks for basic_block.flags.
 304
 305    BB_HOT_PARTITION and BB_COLD_PARTITION should be preserved throughout
 306    the compilation, so they are never cleared.
 307
 308    All other flags may be cleared by clear_bb_flags().  It is generally
 309    a bad idea to rely on any flags being up-to-date.  */
 310
 311 enum
 312 {
 313
 314   /* Set if insns in BB have are modified.  Used for updating liveness info.  */
 315   BB_DIRTY = 1,
 316
 317   /* Only set on blocks that have just been created by create_bb.  */
 318   BB_NEW = 2,
 319
 320   /* Set by find_unreachable_blocks.  Do not rely on this being set in any
 321      pass.  */
 322   BB_REACHABLE = 4,
 323
 324   /* Set for blocks in an irreducible loop by loop analysis.  */
 325   BB_IRREDUCIBLE_LOOP = 8,
 326
 327   /* Set on blocks that may actually not be single-entry single-exit block.  */
 328   BB_SUPERBLOCK = 16,
 329
 330   /* Set on basic blocks that the scheduler should not touch.  This is used
 331      by SMS to prevent other schedulers from messing with the loop schedule.  */
 332   BB_DISABLE_SCHEDULE = 32,
 333
 334   /* Set on blocks that should be put in a hot section.  */
 335   BB_HOT_PARTITION = 64,
 336
 337   /* Set on blocks that should be put in a cold section.  */
 338   BB_COLD_PARTITION = 128
 339 };
 340
 341 /* Dummy flag for convenience in the hot/cold partitioning code.  */
 342 #define BB_UNPARTITIONED        0
 343
 344 /* Partitions, to be used when partitioning hot and cold basic blocks into
 345    separate sections.  */
 346 #define BB_PARTITION(bb) ((bb)->flags & (BB_HOT_PARTITION|BB_COLD_PARTITION))
 347 #define BB_SET_PARTITION(bb, part) do {                                 \
 348   basic_block bb_ = (bb);                                               \
 349   bb_->flags = ((bb_->flags & ~(BB_HOT_PARTITION|BB_COLD_PARTITION))    \
 350                 | (part));                                              \
 351 } while (0)
 352
 353 #define BB_COPY_PARTITION(dstbb, srcbb) \
 354   BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb))
 355
 356 /* A structure to group all the per-function control flow graph data.
 357    The x_* prefixing is necessary because otherwise references to the
 358    fields of this struct are interpreted as the defines for backward
 359    source compatibility following the definition of this struct.  */
 360 struct control_flow_graph GTY(())
 361 {
 362   /* Block pointers for the exit and entry of a function.
 363      These are always the head and tail of the basic block list.  */
 364   basic_block x_entry_block_ptr;
 365   basic_block x_exit_block_ptr;
 366
 367   /* Index by basic block number, get basic block struct info.  */
 368   varray_type x_basic_block_info;
 369
 370   /* Number of basic blocks in this flow graph.  */
 371   int x_n_basic_blocks;
 372
 373   /* Number of edges in this flow graph.  */
 374   int x_n_edges;
 375
 376   /* The first free basic block number.  */
 377   int x_last_basic_block;
 378
 379   /* Mapping of labels to their associated blocks.  At present
 380      only used for the tree CFG.  */
 381   varray_type x_label_to_block_map;
 382
 383   enum profile_status {
 384     PROFILE_ABSENT,
 385     PROFILE_GUESSED,
 386     PROFILE_READ
 387   } x_profile_status;
 388 };
 389
 390 /* Defines for accessing the fields of the CFG structure for function FN.  */
 391 #define ENTRY_BLOCK_PTR_FOR_FUNCTION(FN)     ((FN)->cfg->x_entry_block_ptr)
 392 #define EXIT_BLOCK_PTR_FOR_FUNCTION(FN)      ((FN)->cfg->x_exit_block_ptr)
 393 #define basic_block_info_for_function(FN)    ((FN)->cfg->x_basic_block_info)
 394 #define n_basic_blocks_for_function(FN)      ((FN)->cfg->x_n_basic_blocks)
 395 #define n_edges_for_function(FN)             ((FN)->cfg->x_n_edges)
 396 #define last_basic_block_for_function(FN)    ((FN)->cfg->x_last_basic_block)
 397 #define label_to_block_map_for_function(FN)  ((FN)->cfg->x_label_to_block_map)
 398
 399 #define BASIC_BLOCK_FOR_FUNCTION(FN,N) \
 400   (VARRAY_BB (basic_block_info_for_function(FN), (N)))
 401
 402 /* Defines for textual backward source compatibility.  */
 403 #define ENTRY_BLOCK_PTR         (cfun->cfg->x_entry_block_ptr)
 404 #define EXIT_BLOCK_PTR          (cfun->cfg->x_exit_block_ptr)
 405 #define basic_block_info        (cfun->cfg->x_basic_block_info)
 406 #define n_basic_blocks          (cfun->cfg->x_n_basic_blocks)
 407 #define n_edges                 (cfun->cfg->x_n_edges)
 408 #define last_basic_block        (cfun->cfg->x_last_basic_block)
 409 #define label_to_block_map      (cfun->cfg->x_label_to_block_map)
 410 #define profile_status          (cfun->cfg->x_profile_status)
 411
 412 #define BASIC_BLOCK(N)          (VARRAY_BB (basic_block_info, (N)))
 413
 414 /* TRUE if we should re-run loop discovery after threading jumps, FALSE
 415    otherwise.  */
 416 extern bool rediscover_loops_after_threading;
 417
 418 /* For iterating over basic blocks.  */
 419 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 420   for (BB = FROM; BB != TO; BB = BB->DIR)
 421
 422 #define FOR_EACH_BB_FN(BB, FN) \
 423   FOR_BB_BETWEEN (BB, (FN)->cfg->x_entry_block_ptr->next_bb, (FN)->cfg->x_exit_block_ptr, next_bb)
 424
 425 #define FOR_EACH_BB(BB) FOR_EACH_BB_FN (BB, cfun)
 426
 427 #define FOR_EACH_BB_REVERSE_FN(BB, FN) \
 428   FOR_BB_BETWEEN (BB, (FN)->cfg->x_exit_block_ptr->prev_bb, (FN)->cfg->x_entry_block_ptr, prev_bb)
 429
 430 #define FOR_EACH_BB_REVERSE(BB) FOR_EACH_BB_REVERSE_FN(BB, cfun)
 431
 432 /* For iterating over insns in basic block.  */
 433 #define FOR_BB_INSNS(BB, INSN)                  \
 434   for ((INSN) = BB_HEAD (BB);                   \
 435        (INSN) != NEXT_INSN (BB_END (BB));       \
 436        (INSN) = NEXT_INSN (INSN))
 437
 438 #define FOR_BB_INSNS_REVERSE(BB, INSN)          \
 439   for ((INSN) = BB_END (BB);                    \
 440        (INSN) != PREV_INSN (BB_HEAD (BB));      \
 441        (INSN) = PREV_INSN (INSN))
 442
 443 /* Cycles through _all_ basic blocks, even the fake ones (entry and
 444    exit block).  */
 445
 446 #define FOR_ALL_BB(BB) \
 447   for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
 448
 449 #define FOR_ALL_BB_FN(BB, FN) \
 450   for (BB = ENTRY_BLOCK_PTR_FOR_FUNCTION (FN); BB; BB = BB->next_bb)
 451
 452 /* Special labels found during CFG build.  */
 453
 454 extern GTY(()) rtx label_value_list;
 455
 456 extern bitmap_obstack reg_obstack;
 457
 458 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 459    If the value is REG_BLOCK_GLOBAL (-2),
 460    it means (REG n) is used in more than one basic block.
 461    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 462    This information remains valid for the rest of the compilation
 463    of the current function; it is used to control register allocation.  */
 464
 465 #define REG_BLOCK_UNKNOWN -1
 466 #define REG_BLOCK_GLOBAL -2
 467
 468 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 469 \f
 470 /* Stuff for recording basic block info.  */
 471
 472 #define BB_HEAD(B)      (B)->head_
 473 #define BB_END(B)       (B)->end_
 474
 475 /* Special block numbers [markers] for entry and exit.  */
 476 #define ENTRY_BLOCK (-1)
 477 #define EXIT_BLOCK (-2)
 478
 479 /* Special block number not valid for any block.  */
 480 #define INVALID_BLOCK (-3)
 481
 482 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 483 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 484
 485 extern void compute_bb_for_insn (void);
 486 extern void free_bb_for_insn (void);
 487 extern void update_bb_for_insn (basic_block);
 488
 489 extern void free_basic_block_vars (void);
 490
 491 extern void insert_insn_on_edge (rtx, edge);
 492 bool safe_insert_insn_on_edge (rtx, edge);
 493
 494 extern void commit_edge_insertions (void);
 495 extern void commit_edge_insertions_watch_calls (void);
 496
 497 extern void remove_fake_edges (void);
 498 extern void remove_fake_exit_edges (void);
 499 extern void add_noreturn_fake_exit_edges (void);
 500 extern void connect_infinite_loops_to_exit (void);
 501 extern edge unchecked_make_edge (basic_block, basic_block, int);
 502 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int);
 503 extern edge make_edge (basic_block, basic_block, int);
 504 extern edge make_single_succ_edge (basic_block, basic_block, int);
 505 extern void remove_edge (edge);
 506 extern void redirect_edge_succ (edge, basic_block);
 507 extern edge redirect_edge_succ_nodup (edge, basic_block);
 508 extern void redirect_edge_pred (edge, basic_block);
 509 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
 510 extern void clear_bb_flags (void);
 511 extern void flow_reverse_top_sort_order_compute (int *);
 512 extern int flow_depth_first_order_compute (int *, int *);
 513 extern int dfs_enumerate_from (basic_block, int,
 514                                bool (*)(basic_block, void *),
 515                                basic_block *, int, void *);
 516 extern void compute_dominance_frontiers (bitmap *);
 517 extern void dump_edge_info (FILE *, edge, int);
 518 extern void brief_dump_cfg (FILE *);
 519 extern void clear_edges (void);
 520 extern rtx first_insn_after_basic_block_note (basic_block);
 521 extern void scale_bbs_frequencies_int (basic_block *, int, int, int);
 522 extern void scale_bbs_frequencies_gcov_type (basic_block *, int, gcov_type,
 523                                              gcov_type);
 524
 525 /* Structure to group all of the information to process IF-THEN and
 526    IF-THEN-ELSE blocks for the conditional execution support.  This
 527    needs to be in a public file in case the IFCVT macros call
 528    functions passing the ce_if_block data structure.  */
 529
 530 typedef struct ce_if_block
 531 {
 532   basic_block test_bb;                  /* First test block.  */
 533   basic_block then_bb;                  /* THEN block.  */
 534   basic_block else_bb;                  /* ELSE block or NULL.  */
 535   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 536   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 537   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 538   int num_and_and_blocks;               /* # of && blocks.  */
 539   int num_or_or_blocks;                 /* # of || blocks.  */
 540   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 541   int and_and_p;                        /* Complex test is &&.  */
 542   int num_then_insns;                   /* # of insns in THEN block.  */
 543   int num_else_insns;                   /* # of insns in ELSE block.  */
 544   int pass;                             /* Pass number.  */
 545
 546 #ifdef IFCVT_EXTRA_FIELDS
 547   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 548 #endif
 549
 550 } ce_if_block_t;
 551
 552 /* This structure maintains an edge list vector.  */
 553 struct edge_list
 554 {
 555   int num_blocks;
 556   int num_edges;
 557   edge *index_to_edge;
 558 };
 559
 560 /* The base value for branch probability notes and edge probabilities.  */
 561 #define REG_BR_PROB_BASE  10000
 562
 563 /* This is the value which indicates no edge is present.  */
 564 #define EDGE_INDEX_NO_EDGE      -1
 565
 566 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 567    if there is no edge between the 2 basic blocks.  */
 568 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 569
 570 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 571    block which is either the pred or succ end of the indexed edge.  */
 572 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 573 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 574
 575 /* INDEX_EDGE returns a pointer to the edge.  */
 576 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 577
 578 /* Number of edges in the compressed edge list.  */
 579 #define NUM_EDGES(el)                   ((el)->num_edges)
 580
 581 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 582 #define FALLTHRU_EDGE(bb)               (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 583                                          ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
 584
 585 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 586 #define BRANCH_EDGE(bb)                 (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 587                                          ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
 588
 589 /* Return expected execution frequency of the edge E.  */
 590 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 591                                           * (e)->probability \
 592                                           + REG_BR_PROB_BASE / 2) \
 593                                          / REG_BR_PROB_BASE)
 594
 595 /* Return nonzero if edge is critical.  */
 596 #define EDGE_CRITICAL_P(e)              (EDGE_COUNT ((e)->src->succs) >= 2 \
 597                                          && EDGE_COUNT ((e)->dest->preds) >= 2)
 598
 599 #define EDGE_COUNT(ev)                  VEC_length (edge, (ev))
 600 #define EDGE_I(ev,i)                    VEC_index  (edge, (ev), (i))
 601 #define EDGE_PRED(bb,i)                 VEC_index  (edge, (bb)->preds, (i))
 602 #define EDGE_SUCC(bb,i)                 VEC_index  (edge, (bb)->succs, (i))
 603
 604 /* Returns true if BB has precisely one successor.  */
 605
 606 static inline bool
 607 single_succ_p (basic_block bb)
 608 {
 609   return EDGE_COUNT (bb->succs) == 1;
 610 }
 611
 612 /* Returns true if BB has precisely one predecessor.  */
 613
 614 static inline bool
 615 single_pred_p (basic_block bb)
 616 {
 617   return EDGE_COUNT (bb->preds) == 1;
 618 }
 619
 620 /* Returns the single successor edge of basic block BB.  Aborts if
 621    BB does not have exactly one successor.  */
 622
 623 static inline edge
 624 single_succ_edge (basic_block bb)
 625 {
 626   gcc_assert (single_succ_p (bb));
 627   return EDGE_SUCC (bb, 0);
 628 }
 629
 630 /* Returns the single predecessor edge of basic block BB.  Aborts
 631    if BB does not have exactly one predecessor.  */
 632
 633 static inline edge
 634 single_pred_edge (basic_block bb)
 635 {
 636   gcc_assert (single_pred_p (bb));
 637   return EDGE_PRED (bb, 0);
 638 }
 639
 640 /* Returns the single successor block of basic block BB.  Aborts
 641    if BB does not have exactly one successor.  */
 642
 643 static inline basic_block
 644 single_succ (basic_block bb)
 645 {
 646   return single_succ_edge (bb)->dest;
 647 }
 648
 649 /* Returns the single predecessor block of basic block BB.  Aborts
 650    if BB does not have exactly one predecessor.*/
 651
 652 static inline basic_block
 653 single_pred (basic_block bb)
 654 {
 655   return single_pred_edge (bb)->src;
 656 }
 657
 658 /* Iterator object for edges.  */
 659
 660 typedef struct {
 661   unsigned index;
 662   VEC(edge,gc) **container;
 663 } edge_iterator;
 664
 665 static inline VEC(edge,gc) *
 666 ei_container (edge_iterator i)
 667 {
 668   gcc_assert (i.container);
 669   return *i.container;
 670 }
 671
 672 #define ei_start(iter) ei_start_1 (&(iter))
 673 #define ei_last(iter) ei_last_1 (&(iter))
 674
 675 /* Return an iterator pointing to the start of an edge vector.  */
 676 static inline edge_iterator
 677 ei_start_1 (VEC(edge,gc) **ev)
 678 {
 679   edge_iterator i;
 680
 681   i.index = 0;
 682   i.container = ev;
 683
 684   return i;
 685 }
 686
 687 /* Return an iterator pointing to the last element of an edge
 688    vector.  */
 689 static inline edge_iterator
 690 ei_last_1 (VEC(edge,gc) **ev)
 691 {
 692   edge_iterator i;
 693
 694   i.index = EDGE_COUNT (*ev) - 1;
 695   i.container = ev;
 696
 697   return i;
 698 }
 699
 700 /* Is the iterator `i' at the end of the sequence?  */
 701 static inline bool
 702 ei_end_p (edge_iterator i)
 703 {
 704   return (i.index == EDGE_COUNT (ei_container (i)));
 705 }
 706
 707 /* Is the iterator `i' at one position before the end of the
 708    sequence?  */
 709 static inline bool
 710 ei_one_before_end_p (edge_iterator i)
 711 {
 712   return (i.index + 1 == EDGE_COUNT (ei_container (i)));
 713 }
 714
 715 /* Advance the iterator to the next element.  */
 716 static inline void
 717 ei_next (edge_iterator *i)
 718 {
 719   gcc_assert (i->index < EDGE_COUNT (ei_container (*i)));
 720   i->index++;
 721 }
 722
 723 /* Move the iterator to the previous element.  */
 724 static inline void
 725 ei_prev (edge_iterator *i)
 726 {
 727   gcc_assert (i->index > 0);
 728   i->index--;
 729 }
 730
 731 /* Return the edge pointed to by the iterator `i'.  */
 732 static inline edge
 733 ei_edge (edge_iterator i)
 734 {
 735   return EDGE_I (ei_container (i), i.index);
 736 }
 737
 738 /* Return an edge pointed to by the iterator.  Do it safely so that
 739    NULL is returned when the iterator is pointing at the end of the
 740    sequence.  */
 741 static inline edge
 742 ei_safe_edge (edge_iterator i)
 743 {
 744   return !ei_end_p (i) ? ei_edge (i) : NULL;
 745 }
 746
 747 /* Return 1 if we should continue to iterate.  Return 0 otherwise.
 748    *Edge P is set to the next edge if we are to continue to iterate
 749    and NULL otherwise.  */
 750
 751 static inline bool
 752 ei_cond (edge_iterator ei, edge *p)
 753 {
 754   if (!ei_end_p (ei))
 755     {
 756       *p = ei_edge (ei);
 757       return 1;
 758     }
 759   else
 760     {
 761       *p = NULL;
 762       return 0;
 763     }
 764 }
 765
 766 /* This macro serves as a convenient way to iterate each edge in a
 767    vector of predecessor or successor edges.  It must not be used when
 768    an element might be removed during the traversal, otherwise
 769    elements will be missed.  Instead, use a for-loop like that shown
 770    in the following pseudo-code:
 771
 772    FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 773      {
 774         IF (e != taken_edge)
 775           remove_edge (e);
 776         ELSE
 777           ei_next (&ei);
 778      }
 779 */
 780
 781 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC)       \
 782   for ((ITER) = ei_start ((EDGE_VEC));          \
 783        ei_cond ((ITER), &(EDGE));               \
 784        ei_next (&(ITER)))
 785
 786 struct edge_list * create_edge_list (void);
 787 void free_edge_list (struct edge_list *);
 788 void print_edge_list (FILE *, struct edge_list *);
 789 void verify_edge_list (FILE *, struct edge_list *);
 790 int find_edge_index (struct edge_list *, basic_block, basic_block);
 791 edge find_edge (basic_block, basic_block);
 792
 793
 794 enum update_life_extent
 795 {
 796   UPDATE_LIFE_LOCAL = 0,
 797   UPDATE_LIFE_GLOBAL = 1,
 798   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 799 };
 800
 801 /* Flags for life_analysis and update_life_info.  */
 802
 803 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 804 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 805 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 806 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 807 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 808 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 809                                            by dead code removal.  */
 810 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 811 #define PROP_SCAN_DEAD_STORES   128     /* Scan for dead code.  */
 812 #define PROP_ASM_SCAN           256     /* Internal flag used within flow.c
 813                                            to flag analysis of asms.  */
 814 #define PROP_DEAD_INSN          1024    /* Internal flag used within flow.c
 815                                            to flag analysis of dead insn.  */
 816 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 817                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 818                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 819                                  | PROP_ALLOW_CFG_CHANGES \
 820                                  | PROP_SCAN_DEAD_STORES)
 821 #define PROP_POSTRELOAD         (PROP_DEATH_NOTES  \
 822                                  | PROP_KILL_DEAD_CODE  \
 823                                  | PROP_SCAN_DEAD_CODE \
 824                                  | PROP_SCAN_DEAD_STORES)
 825
 826 #define CLEANUP_EXPENSIVE       1       /* Do relatively expensive optimizations
 827                                            except for edge forwarding */
 828 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 829 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 830                                            to care REG_DEAD notes.  */
 831 #define CLEANUP_PRE_LOOP        8       /* Take care to preserve syntactic loop
 832                                            notes.  */
 833 #define CLEANUP_UPDATE_LIFE     16      /* Keep life information up to date.  */
 834 #define CLEANUP_THREADING       32      /* Do jump threading.  */
 835 #define CLEANUP_NO_INSN_DEL     64      /* Do not try to delete trivially dead
 836                                            insns.  */
 837 #define CLEANUP_CFGLAYOUT       128     /* Do cleanup in cfglayout mode.  */
 838 #define CLEANUP_LOG_LINKS       256     /* Update log links.  */
 839
 840 extern void life_analysis (FILE *, int);
 841 extern int update_life_info (sbitmap, enum update_life_extent, int);
 842 extern int update_life_info_in_dirty_blocks (enum update_life_extent, int);
 843 extern int count_or_remove_death_notes (sbitmap, int);
 844 extern int propagate_block (basic_block, regset, regset, regset, int);
 845
 846 struct propagate_block_info;
 847 extern rtx propagate_one_insn (struct propagate_block_info *, rtx);
 848 extern struct propagate_block_info *init_propagate_block_info
 849  (basic_block, regset, regset, regset, int);
 850 extern void free_propagate_block_info (struct propagate_block_info *);
 851
 852 /* In lcm.c */
 853 extern struct edge_list *pre_edge_lcm (FILE *, int, sbitmap *, sbitmap *,
 854                                        sbitmap *, sbitmap *, sbitmap **,
 855                                        sbitmap **);
 856 extern struct edge_list *pre_edge_rev_lcm (FILE *, int, sbitmap *,
 857                                            sbitmap *, sbitmap *,
 858                                            sbitmap *, sbitmap **,
 859                                            sbitmap **);
 860 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
 861 extern int optimize_mode_switching (FILE *);
 862
 863 /* In predict.c */
 864 extern void estimate_probability (struct loops *);
 865 extern void expected_value_to_br_prob (void);
 866 extern bool maybe_hot_bb_p (basic_block);
 867 extern bool probably_cold_bb_p (basic_block);
 868 extern bool probably_never_executed_bb_p (basic_block);
 869 extern bool tree_predicted_by_p (basic_block, enum br_predictor);
 870 extern bool rtl_predicted_by_p (basic_block, enum br_predictor);
 871 extern void tree_predict_edge (edge, enum br_predictor, int);
 872 extern void rtl_predict_edge (edge, enum br_predictor, int);
 873 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
 874 extern void guess_outgoing_edge_probabilities (basic_block);
 875
 876 /* In flow.c */
 877 extern void init_flow (void);
 878 extern void debug_bb (basic_block);
 879 extern basic_block debug_bb_n (int);
 880 extern void dump_regset (regset, FILE *);
 881 extern void debug_regset (regset);
 882 extern void allocate_reg_life_data (void);
 883 extern void expunge_block (basic_block);
 884 extern void link_block (basic_block, basic_block);
 885 extern void unlink_block (basic_block);
 886 extern void compact_blocks (void);
 887 extern basic_block alloc_block (void);
 888 extern void find_unreachable_blocks (void);
 889 extern int delete_noop_moves (void);
 890 extern basic_block force_nonfallthru (edge);
 891 extern rtx block_label (basic_block);
 892 extern bool forwarder_block_p (basic_block);
 893 extern bool purge_all_dead_edges (void);
 894 extern bool purge_dead_edges (basic_block);
 895 extern void find_many_sub_basic_blocks (sbitmap);
 896 extern void rtl_make_eh_edge (sbitmap, basic_block, rtx);
 897 extern bool can_fallthru (basic_block, basic_block);
 898 extern bool could_fall_through (basic_block, basic_block);
 899 extern void flow_nodes_print (const char *, const sbitmap, FILE *);
 900 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
 901 extern void alloc_aux_for_block (basic_block, int);
 902 extern void alloc_aux_for_blocks (int);
 903 extern void clear_aux_for_blocks (void);
 904 extern void free_aux_for_blocks (void);
 905 extern void alloc_aux_for_edge (edge, int);
 906 extern void alloc_aux_for_edges (int);
 907 extern void clear_aux_for_edges (void);
 908 extern void free_aux_for_edges (void);
 909 extern void find_basic_blocks (rtx);
 910 extern bool cleanup_cfg (int);
 911 extern bool delete_unreachable_blocks (void);
 912 extern bool merge_seq_blocks (void);
 913
 914 typedef struct conflict_graph_def *conflict_graph;
 915
 916 /* Callback function when enumerating conflicts.  The arguments are
 917    the smaller and larger regno in the conflict.  Returns zero if
 918    enumeration is to continue, nonzero to halt enumeration.  */
 919 typedef int (*conflict_graph_enum_fn) (int, int, void *);
 920
 921
 922 /* Prototypes of operations on conflict graphs.  */
 923
 924 extern conflict_graph conflict_graph_new
 925  (int);
 926 extern void conflict_graph_delete (conflict_graph);
 927 extern int conflict_graph_add (conflict_graph, int, int);
 928 extern int conflict_graph_conflict_p (conflict_graph, int, int);
 929 extern void conflict_graph_enum (conflict_graph, int, conflict_graph_enum_fn,
 930                                  void *);
 931 extern void conflict_graph_merge_regs (conflict_graph, int, int);
 932 extern void conflict_graph_print (conflict_graph, FILE*);
 933 extern bool mark_dfs_back_edges (void);
 934 extern void set_edge_can_fallthru_flag (void);
 935 extern void update_br_prob_note (basic_block);
 936 extern void fixup_abnormal_edges (void);
 937 extern bool inside_basic_block_p (rtx);
 938 extern bool control_flow_insn_p (rtx);
 939
 940 /* In bb-reorder.c */
 941 extern void reorder_basic_blocks (unsigned int);
 942 extern void duplicate_computed_gotos (void);
 943 extern void partition_hot_cold_basic_blocks (void);
 944
 945 /* In cfg.c */
 946 extern void initialize_bb_rbi (basic_block bb);
 947
 948 /* In dominance.c */
 949
 950 enum cdi_direction
 951 {
 952   CDI_DOMINATORS,
 953   CDI_POST_DOMINATORS
 954 };
 955
 956 enum dom_state
 957 {
 958   DOM_NONE,             /* Not computed at all.  */
 959   DOM_NO_FAST_QUERY,    /* The data is OK, but the fast query data are not usable.  */
 960   DOM_OK                /* Everything is ok.  */
 961 };
 962
 963 extern enum dom_state dom_computed[2];
 964
 965 extern bool dom_info_available_p (enum cdi_direction);
 966 extern void calculate_dominance_info (enum cdi_direction);
 967 extern void free_dominance_info (enum cdi_direction);
 968 extern basic_block nearest_common_dominator (enum cdi_direction,
 969                                              basic_block, basic_block);
 970 extern basic_block nearest_common_dominator_for_set (enum cdi_direction,
 971                                                      bitmap);
 972 extern void set_immediate_dominator (enum cdi_direction, basic_block,
 973                                      basic_block);
 974 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
 975 extern bool dominated_by_p (enum cdi_direction, basic_block, basic_block);
 976 extern int get_dominated_by (enum cdi_direction, basic_block, basic_block **);
 977 extern unsigned get_dominated_by_region (enum cdi_direction, basic_block *,
 978                                          unsigned, basic_block *);
 979 extern void add_to_dominance_info (enum cdi_direction, basic_block);
 980 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
 981 basic_block recount_dominator (enum cdi_direction, basic_block);
 982 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
 983                                            basic_block);
 984 extern void iterate_fix_dominators (enum cdi_direction, basic_block *, int);
 985 extern void verify_dominators (enum cdi_direction);
 986 extern basic_block first_dom_son (enum cdi_direction, basic_block);
 987 extern basic_block next_dom_son (enum cdi_direction, basic_block);
 988 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
 989 extern void break_superblocks (void);
 990 extern void check_bb_profile (basic_block, FILE *);
 991 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
 992
 993 #include "cfghooks.h"
 994
 995 #endif /* GCC_BASIC_BLOCK_H */