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, 51 Franklin Street, Fifth Floor, Boston, MA
  20 02110-1301, 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 struct rtl_bb_info;
 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   /* Pointers to the first and last trees of the block.  */
 217   tree stmt_list;
 218
 219   /* The edges into and out of the block.  */
 220   VEC(edge,gc) *preds;
 221   VEC(edge,gc) *succs;
 222
 223   /* Auxiliary info specific to a pass.  */
 224   PTR GTY ((skip (""))) aux;
 225
 226   /* Innermost loop containing the block.  */
 227   struct loop * GTY ((skip (""))) loop_father;
 228
 229   /* The dominance and postdominance information node.  */
 230   struct et_node * GTY ((skip (""))) dom[2];
 231
 232   /* Previous and next blocks in the chain.  */
 233   struct basic_block_def *prev_bb;
 234   struct basic_block_def *next_bb;
 235
 236   union basic_block_il_dependent {
 237       struct rtl_bb_info * GTY ((tag ("1"))) rtl;
 238     } GTY ((desc ("((%1.flags & BB_RTL) != 0)"))) il;
 239
 240   /* Chain of PHI nodes for this block.  */
 241   tree phi_nodes;
 242
 243   /* A list of predictions.  */
 244   struct edge_prediction *predictions;
 245
 246   /* Expected number of executions: calculated in profile.c.  */
 247   gcov_type count;
 248
 249   /* The index of this block.  */
 250   int index;
 251
 252   /* The loop depth of this block.  */
 253   int loop_depth;
 254
 255   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 256   int frequency;
 257
 258   /* Various flags.  See BB_* below.  */
 259   int flags;
 260 };
 261
 262 struct rtl_bb_info GTY(())
 263 {
 264   /* The first and last insns of the block.  */
 265   rtx head_;
 266   rtx end_;
 267
 268   /* The registers that are live on entry to this block.  */
 269   bitmap GTY ((skip (""))) global_live_at_start;
 270
 271   /* The registers that are live on exit from this block.  */
 272   bitmap GTY ((skip (""))) global_live_at_end;
 273
 274   /* In CFGlayout mode points to insn notes/jumptables to be placed just before
 275      and after the block.   */
 276   rtx header;
 277   rtx footer;
 278
 279   /* This field is used by the bb-reorder and tracer passes.  */
 280   int visited;
 281 };
 282
 283 typedef struct basic_block_def *basic_block;
 284
 285 #define BB_FREQ_MAX 10000
 286
 287 /* Masks for basic_block.flags.
 288
 289    BB_HOT_PARTITION and BB_COLD_PARTITION should be preserved throughout
 290    the compilation, so they are never cleared.
 291
 292    All other flags may be cleared by clear_bb_flags().  It is generally
 293    a bad idea to rely on any flags being up-to-date.  */
 294
 295 enum bb_flags
 296 {
 297
 298   /* Set if insns in BB have are modified.  Used for updating liveness info.  */
 299   BB_DIRTY = 1,
 300
 301   /* Only set on blocks that have just been created by create_bb.  */
 302   BB_NEW = 2,
 303
 304   /* Set by find_unreachable_blocks.  Do not rely on this being set in any
 305      pass.  */
 306   BB_REACHABLE = 4,
 307
 308   /* Set for blocks in an irreducible loop by loop analysis.  */
 309   BB_IRREDUCIBLE_LOOP = 8,
 310
 311   /* Set on blocks that may actually not be single-entry single-exit block.  */
 312   BB_SUPERBLOCK = 16,
 313
 314   /* Set on basic blocks that the scheduler should not touch.  This is used
 315      by SMS to prevent other schedulers from messing with the loop schedule.  */
 316   BB_DISABLE_SCHEDULE = 32,
 317
 318   /* Set on blocks that should be put in a hot section.  */
 319   BB_HOT_PARTITION = 64,
 320
 321   /* Set on blocks that should be put in a cold section.  */
 322   BB_COLD_PARTITION = 128,
 323
 324   /* Set on block that was duplicated.  */
 325   BB_DUPLICATED = 256,
 326
 327   /* Set on blocks that are in RTL format.  */
 328   BB_RTL = 1024,
 329
 330   /* Set on blocks that are forwarder blocks.
 331      Only used in cfgcleanup.c.  */
 332   BB_FORWARDER_BLOCK = 2048,
 333
 334   /* Set on blocks that cannot be threaded through.
 335      Only used in cfgcleanup.c.  */
 336   BB_NONTHREADABLE_BLOCK = 4096
 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 #define FOR_ALL_BB_FN(BB, FN) \
 448   for (BB = ENTRY_BLOCK_PTR_FOR_FUNCTION (FN); BB; BB = BB->next_bb)
 449
 450 extern bitmap_obstack reg_obstack;
 451
 452 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 453    If the value is REG_BLOCK_GLOBAL (-2),
 454    it means (REG n) is used in more than one basic block.
 455    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 456    This information remains valid for the rest of the compilation
 457    of the current function; it is used to control register allocation.  */
 458
 459 #define REG_BLOCK_UNKNOWN -1
 460 #define REG_BLOCK_GLOBAL -2
 461
 462 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 463 \f
 464 /* Stuff for recording basic block info.  */
 465
 466 #define BB_HEAD(B)      (B)->il.rtl->head_
 467 #define BB_END(B)       (B)->il.rtl->end_
 468
 469 /* Special block numbers [markers] for entry and exit.  */
 470 #define ENTRY_BLOCK (-1)
 471 #define EXIT_BLOCK (-2)
 472
 473 /* Special block number not valid for any block.  */
 474 #define INVALID_BLOCK (-3)
 475
 476 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 477 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 478
 479 extern void compute_bb_for_insn (void);
 480 extern void free_bb_for_insn (void);
 481 extern void update_bb_for_insn (basic_block);
 482
 483 extern void free_basic_block_vars (void);
 484
 485 extern void insert_insn_on_edge (rtx, edge);
 486 bool safe_insert_insn_on_edge (rtx, edge);
 487
 488 extern void commit_edge_insertions (void);
 489 extern void commit_edge_insertions_watch_calls (void);
 490
 491 extern void remove_fake_edges (void);
 492 extern void remove_fake_exit_edges (void);
 493 extern void add_noreturn_fake_exit_edges (void);
 494 extern void connect_infinite_loops_to_exit (void);
 495 extern edge unchecked_make_edge (basic_block, basic_block, int);
 496 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int);
 497 extern edge make_edge (basic_block, basic_block, int);
 498 extern edge make_single_succ_edge (basic_block, basic_block, int);
 499 extern void remove_edge (edge);
 500 extern void redirect_edge_succ (edge, basic_block);
 501 extern edge redirect_edge_succ_nodup (edge, basic_block);
 502 extern void redirect_edge_pred (edge, basic_block);
 503 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
 504 extern void clear_bb_flags (void);
 505 extern void flow_reverse_top_sort_order_compute (int *);
 506 extern int flow_depth_first_order_compute (int *, int *);
 507 extern int dfs_enumerate_from (basic_block, int,
 508                                bool (*)(basic_block, void *),
 509                                basic_block *, int, void *);
 510 extern void compute_dominance_frontiers (bitmap *);
 511 extern void dump_edge_info (FILE *, edge, int);
 512 extern void brief_dump_cfg (FILE *);
 513 extern void clear_edges (void);
 514 extern rtx first_insn_after_basic_block_note (basic_block);
 515 extern void scale_bbs_frequencies_int (basic_block *, int, int, int);
 516 extern void scale_bbs_frequencies_gcov_type (basic_block *, int, gcov_type,
 517                                              gcov_type);
 518
 519 /* Structure to group all of the information to process IF-THEN and
 520    IF-THEN-ELSE blocks for the conditional execution support.  This
 521    needs to be in a public file in case the IFCVT macros call
 522    functions passing the ce_if_block data structure.  */
 523
 524 typedef struct ce_if_block
 525 {
 526   basic_block test_bb;                  /* First test block.  */
 527   basic_block then_bb;                  /* THEN block.  */
 528   basic_block else_bb;                  /* ELSE block or NULL.  */
 529   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 530   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 531   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 532   int num_and_and_blocks;               /* # of && blocks.  */
 533   int num_or_or_blocks;                 /* # of || blocks.  */
 534   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 535   int and_and_p;                        /* Complex test is &&.  */
 536   int num_then_insns;                   /* # of insns in THEN block.  */
 537   int num_else_insns;                   /* # of insns in ELSE block.  */
 538   int pass;                             /* Pass number.  */
 539
 540 #ifdef IFCVT_EXTRA_FIELDS
 541   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 542 #endif
 543
 544 } ce_if_block_t;
 545
 546 /* This structure maintains an edge list vector.  */
 547 struct edge_list
 548 {
 549   int num_blocks;
 550   int num_edges;
 551   edge *index_to_edge;
 552 };
 553
 554 /* The base value for branch probability notes and edge probabilities.  */
 555 #define REG_BR_PROB_BASE  10000
 556
 557 /* This is the value which indicates no edge is present.  */
 558 #define EDGE_INDEX_NO_EDGE      -1
 559
 560 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 561    if there is no edge between the 2 basic blocks.  */
 562 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 563
 564 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 565    block which is either the pred or succ end of the indexed edge.  */
 566 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 567 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 568
 569 /* INDEX_EDGE returns a pointer to the edge.  */
 570 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 571
 572 /* Number of edges in the compressed edge list.  */
 573 #define NUM_EDGES(el)                   ((el)->num_edges)
 574
 575 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 576 #define FALLTHRU_EDGE(bb)               (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 577                                          ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
 578
 579 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 580 #define BRANCH_EDGE(bb)                 (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 581                                          ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
 582
 583 /* Return expected execution frequency of the edge E.  */
 584 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 585                                           * (e)->probability \
 586                                           + REG_BR_PROB_BASE / 2) \
 587                                          / REG_BR_PROB_BASE)
 588
 589 /* Return nonzero if edge is critical.  */
 590 #define EDGE_CRITICAL_P(e)              (EDGE_COUNT ((e)->src->succs) >= 2 \
 591                                          && EDGE_COUNT ((e)->dest->preds) >= 2)
 592
 593 #define EDGE_COUNT(ev)                  VEC_length (edge, (ev))
 594 #define EDGE_I(ev,i)                    VEC_index  (edge, (ev), (i))
 595 #define EDGE_PRED(bb,i)                 VEC_index  (edge, (bb)->preds, (i))
 596 #define EDGE_SUCC(bb,i)                 VEC_index  (edge, (bb)->succs, (i))
 597
 598 /* Returns true if BB has precisely one successor.  */
 599
 600 static inline bool
 601 single_succ_p (basic_block bb)
 602 {
 603   return EDGE_COUNT (bb->succs) == 1;
 604 }
 605
 606 /* Returns true if BB has precisely one predecessor.  */
 607
 608 static inline bool
 609 single_pred_p (basic_block bb)
 610 {
 611   return EDGE_COUNT (bb->preds) == 1;
 612 }
 613
 614 /* Returns the single successor edge of basic block BB.  Aborts if
 615    BB does not have exactly one successor.  */
 616
 617 static inline edge
 618 single_succ_edge (basic_block bb)
 619 {
 620   gcc_assert (single_succ_p (bb));
 621   return EDGE_SUCC (bb, 0);
 622 }
 623
 624 /* Returns the single predecessor edge of basic block BB.  Aborts
 625    if BB does not have exactly one predecessor.  */
 626
 627 static inline edge
 628 single_pred_edge (basic_block bb)
 629 {
 630   gcc_assert (single_pred_p (bb));
 631   return EDGE_PRED (bb, 0);
 632 }
 633
 634 /* Returns the single successor block of basic block BB.  Aborts
 635    if BB does not have exactly one successor.  */
 636
 637 static inline basic_block
 638 single_succ (basic_block bb)
 639 {
 640   return single_succ_edge (bb)->dest;
 641 }
 642
 643 /* Returns the single predecessor block of basic block BB.  Aborts
 644    if BB does not have exactly one predecessor.*/
 645
 646 static inline basic_block
 647 single_pred (basic_block bb)
 648 {
 649   return single_pred_edge (bb)->src;
 650 }
 651
 652 /* Iterator object for edges.  */
 653
 654 typedef struct {
 655   unsigned index;
 656   VEC(edge,gc) **container;
 657 } edge_iterator;
 658
 659 static inline VEC(edge,gc) *
 660 ei_container (edge_iterator i)
 661 {
 662   gcc_assert (i.container);
 663   return *i.container;
 664 }
 665
 666 #define ei_start(iter) ei_start_1 (&(iter))
 667 #define ei_last(iter) ei_last_1 (&(iter))
 668
 669 /* Return an iterator pointing to the start of an edge vector.  */
 670 static inline edge_iterator
 671 ei_start_1 (VEC(edge,gc) **ev)
 672 {
 673   edge_iterator i;
 674
 675   i.index = 0;
 676   i.container = ev;
 677
 678   return i;
 679 }
 680
 681 /* Return an iterator pointing to the last element of an edge
 682    vector.  */
 683 static inline edge_iterator
 684 ei_last_1 (VEC(edge,gc) **ev)
 685 {
 686   edge_iterator i;
 687
 688   i.index = EDGE_COUNT (*ev) - 1;
 689   i.container = ev;
 690
 691   return i;
 692 }
 693
 694 /* Is the iterator `i' at the end of the sequence?  */
 695 static inline bool
 696 ei_end_p (edge_iterator i)
 697 {
 698   return (i.index == EDGE_COUNT (ei_container (i)));
 699 }
 700
 701 /* Is the iterator `i' at one position before the end of the
 702    sequence?  */
 703 static inline bool
 704 ei_one_before_end_p (edge_iterator i)
 705 {
 706   return (i.index + 1 == EDGE_COUNT (ei_container (i)));
 707 }
 708
 709 /* Advance the iterator to the next element.  */
 710 static inline void
 711 ei_next (edge_iterator *i)
 712 {
 713   gcc_assert (i->index < EDGE_COUNT (ei_container (*i)));
 714   i->index++;
 715 }
 716
 717 /* Move the iterator to the previous element.  */
 718 static inline void
 719 ei_prev (edge_iterator *i)
 720 {
 721   gcc_assert (i->index > 0);
 722   i->index--;
 723 }
 724
 725 /* Return the edge pointed to by the iterator `i'.  */
 726 static inline edge
 727 ei_edge (edge_iterator i)
 728 {
 729   return EDGE_I (ei_container (i), i.index);
 730 }
 731
 732 /* Return an edge pointed to by the iterator.  Do it safely so that
 733    NULL is returned when the iterator is pointing at the end of the
 734    sequence.  */
 735 static inline edge
 736 ei_safe_edge (edge_iterator i)
 737 {
 738   return !ei_end_p (i) ? ei_edge (i) : NULL;
 739 }
 740
 741 /* Return 1 if we should continue to iterate.  Return 0 otherwise.
 742    *Edge P is set to the next edge if we are to continue to iterate
 743    and NULL otherwise.  */
 744
 745 static inline bool
 746 ei_cond (edge_iterator ei, edge *p)
 747 {
 748   if (!ei_end_p (ei))
 749     {
 750       *p = ei_edge (ei);
 751       return 1;
 752     }
 753   else
 754     {
 755       *p = NULL;
 756       return 0;
 757     }
 758 }
 759
 760 /* This macro serves as a convenient way to iterate each edge in a
 761    vector of predecessor or successor edges.  It must not be used when
 762    an element might be removed during the traversal, otherwise
 763    elements will be missed.  Instead, use a for-loop like that shown
 764    in the following pseudo-code:
 765
 766    FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 767      {
 768         IF (e != taken_edge)
 769           remove_edge (e);
 770         ELSE
 771           ei_next (&ei);
 772      }
 773 */
 774
 775 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC)       \
 776   for ((ITER) = ei_start ((EDGE_VEC));          \
 777        ei_cond ((ITER), &(EDGE));               \
 778        ei_next (&(ITER)))
 779
 780 struct edge_list * create_edge_list (void);
 781 void free_edge_list (struct edge_list *);
 782 void print_edge_list (FILE *, struct edge_list *);
 783 void verify_edge_list (FILE *, struct edge_list *);
 784 int find_edge_index (struct edge_list *, basic_block, basic_block);
 785 edge find_edge (basic_block, basic_block);
 786
 787
 788 enum update_life_extent
 789 {
 790   UPDATE_LIFE_LOCAL = 0,
 791   UPDATE_LIFE_GLOBAL = 1,
 792   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 793 };
 794
 795 /* Flags for life_analysis and update_life_info.  */
 796
 797 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 798 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 799 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 800 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 801 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 802 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 803                                            by dead code removal.  */
 804 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 805 #define PROP_SCAN_DEAD_STORES   128     /* Scan for dead code.  */
 806 #define PROP_ASM_SCAN           256     /* Internal flag used within flow.c
 807                                            to flag analysis of asms.  */
 808 #define PROP_DEAD_INSN          1024    /* Internal flag used within flow.c
 809                                            to flag analysis of dead insn.  */
 810 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 811                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 812                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 813                                  | PROP_ALLOW_CFG_CHANGES \
 814                                  | PROP_SCAN_DEAD_STORES)
 815 #define PROP_POSTRELOAD         (PROP_DEATH_NOTES  \
 816                                  | PROP_KILL_DEAD_CODE  \
 817                                  | PROP_SCAN_DEAD_CODE \
 818                                  | PROP_SCAN_DEAD_STORES)
 819
 820 #define CLEANUP_EXPENSIVE       1       /* Do relatively expensive optimizations
 821                                            except for edge forwarding */
 822 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 823 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 824                                            to care REG_DEAD notes.  */
 825 #define CLEANUP_PRE_LOOP        8       /* Take care to preserve syntactic loop
 826                                            notes.  */
 827 #define CLEANUP_UPDATE_LIFE     16      /* Keep life information up to date.  */
 828 #define CLEANUP_THREADING       32      /* Do jump threading.  */
 829 #define CLEANUP_NO_INSN_DEL     64      /* Do not try to delete trivially dead
 830                                            insns.  */
 831 #define CLEANUP_CFGLAYOUT       128     /* Do cleanup in cfglayout mode.  */
 832 #define CLEANUP_LOG_LINKS       256     /* Update log links.  */
 833
 834 extern void life_analysis (FILE *, int);
 835 extern int update_life_info (sbitmap, enum update_life_extent, int);
 836 extern int update_life_info_in_dirty_blocks (enum update_life_extent, int);
 837 extern int count_or_remove_death_notes (sbitmap, int);
 838 extern int propagate_block (basic_block, regset, regset, regset, int);
 839
 840 struct propagate_block_info;
 841 extern rtx propagate_one_insn (struct propagate_block_info *, rtx);
 842 extern struct propagate_block_info *init_propagate_block_info
 843  (basic_block, regset, regset, regset, int);
 844 extern void free_propagate_block_info (struct propagate_block_info *);
 845
 846 /* In lcm.c */
 847 extern struct edge_list *pre_edge_lcm (FILE *, int, sbitmap *, sbitmap *,
 848                                        sbitmap *, sbitmap *, sbitmap **,
 849                                        sbitmap **);
 850 extern struct edge_list *pre_edge_rev_lcm (FILE *, int, sbitmap *,
 851                                            sbitmap *, sbitmap *,
 852                                            sbitmap *, sbitmap **,
 853                                            sbitmap **);
 854 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
 855 extern int optimize_mode_switching (FILE *);
 856
 857 /* In predict.c */
 858 extern void estimate_probability (struct loops *);
 859 extern void expected_value_to_br_prob (void);
 860 extern bool maybe_hot_bb_p (basic_block);
 861 extern bool probably_cold_bb_p (basic_block);
 862 extern bool probably_never_executed_bb_p (basic_block);
 863 extern bool tree_predicted_by_p (basic_block, enum br_predictor);
 864 extern bool rtl_predicted_by_p (basic_block, enum br_predictor);
 865 extern void tree_predict_edge (edge, enum br_predictor, int);
 866 extern void rtl_predict_edge (edge, enum br_predictor, int);
 867 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
 868 extern void guess_outgoing_edge_probabilities (basic_block);
 869 extern void remove_predictions_associated_with_edge (edge);
 870
 871 /* In flow.c */
 872 extern void init_flow (void);
 873 extern void debug_bb (basic_block);
 874 extern basic_block debug_bb_n (int);
 875 extern void dump_regset (regset, FILE *);
 876 extern void debug_regset (regset);
 877 extern void allocate_reg_life_data (void);
 878 extern void expunge_block (basic_block);
 879 extern void link_block (basic_block, basic_block);
 880 extern void unlink_block (basic_block);
 881 extern void compact_blocks (void);
 882 extern basic_block alloc_block (void);
 883 extern void find_unreachable_blocks (void);
 884 extern int delete_noop_moves (void);
 885 extern basic_block force_nonfallthru (edge);
 886 extern rtx block_label (basic_block);
 887 extern bool forwarder_block_p (basic_block);
 888 extern bool purge_all_dead_edges (void);
 889 extern bool purge_dead_edges (basic_block);
 890 extern void find_many_sub_basic_blocks (sbitmap);
 891 extern void rtl_make_eh_edge (sbitmap, basic_block, rtx);
 892 extern bool can_fallthru (basic_block, basic_block);
 893 extern bool could_fall_through (basic_block, basic_block);
 894 extern void flow_nodes_print (const char *, const sbitmap, FILE *);
 895 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
 896 extern void alloc_aux_for_block (basic_block, int);
 897 extern void alloc_aux_for_blocks (int);
 898 extern void clear_aux_for_blocks (void);
 899 extern void free_aux_for_blocks (void);
 900 extern void alloc_aux_for_edge (edge, int);
 901 extern void alloc_aux_for_edges (int);
 902 extern void clear_aux_for_edges (void);
 903 extern void free_aux_for_edges (void);
 904 extern void find_basic_blocks (rtx);
 905 extern bool cleanup_cfg (int);
 906 extern bool delete_unreachable_blocks (void);
 907 extern bool merge_seq_blocks (void);
 908
 909 typedef struct conflict_graph_def *conflict_graph;
 910
 911 /* Callback function when enumerating conflicts.  The arguments are
 912    the smaller and larger regno in the conflict.  Returns zero if
 913    enumeration is to continue, nonzero to halt enumeration.  */
 914 typedef int (*conflict_graph_enum_fn) (int, int, void *);
 915
 916
 917 /* Prototypes of operations on conflict graphs.  */
 918
 919 extern conflict_graph conflict_graph_new
 920  (int);
 921 extern void conflict_graph_delete (conflict_graph);
 922 extern int conflict_graph_add (conflict_graph, int, int);
 923 extern int conflict_graph_conflict_p (conflict_graph, int, int);
 924 extern void conflict_graph_enum (conflict_graph, int, conflict_graph_enum_fn,
 925                                  void *);
 926 extern void conflict_graph_merge_regs (conflict_graph, int, int);
 927 extern void conflict_graph_print (conflict_graph, FILE*);
 928 extern bool mark_dfs_back_edges (void);
 929 extern void set_edge_can_fallthru_flag (void);
 930 extern void update_br_prob_note (basic_block);
 931 extern void fixup_abnormal_edges (void);
 932 extern bool inside_basic_block_p (rtx);
 933 extern bool control_flow_insn_p (rtx);
 934
 935 /* In bb-reorder.c */
 936 extern void reorder_basic_blocks (unsigned int);
 937 extern void partition_hot_cold_basic_blocks (void);
 938
 939 /* In dominance.c */
 940
 941 enum cdi_direction
 942 {
 943   CDI_DOMINATORS,
 944   CDI_POST_DOMINATORS
 945 };
 946
 947 enum dom_state
 948 {
 949   DOM_NONE,             /* Not computed at all.  */
 950   DOM_NO_FAST_QUERY,    /* The data is OK, but the fast query data are not usable.  */
 951   DOM_OK                /* Everything is ok.  */
 952 };
 953
 954 extern enum dom_state dom_computed[2];
 955
 956 extern bool dom_info_available_p (enum cdi_direction);
 957 extern void calculate_dominance_info (enum cdi_direction);
 958 extern void free_dominance_info (enum cdi_direction);
 959 extern basic_block nearest_common_dominator (enum cdi_direction,
 960                                              basic_block, basic_block);
 961 extern basic_block nearest_common_dominator_for_set (enum cdi_direction,
 962                                                      bitmap);
 963 extern void set_immediate_dominator (enum cdi_direction, basic_block,
 964                                      basic_block);
 965 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
 966 extern bool dominated_by_p (enum cdi_direction, basic_block, basic_block);
 967 extern int get_dominated_by (enum cdi_direction, basic_block, basic_block **);
 968 extern unsigned get_dominated_by_region (enum cdi_direction, basic_block *,
 969                                          unsigned, basic_block *);
 970 extern void add_to_dominance_info (enum cdi_direction, basic_block);
 971 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
 972 basic_block recount_dominator (enum cdi_direction, basic_block);
 973 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
 974                                            basic_block);
 975 extern void iterate_fix_dominators (enum cdi_direction, basic_block *, int);
 976 extern void verify_dominators (enum cdi_direction);
 977 extern basic_block first_dom_son (enum cdi_direction, basic_block);
 978 extern basic_block next_dom_son (enum cdi_direction, basic_block);
 979 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
 980 extern void break_superblocks (void);
 981 extern void check_bb_profile (basic_block, FILE *);
 982 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
 983 extern void init_rtl_bb_info (basic_block);
 984
 985 extern void initialize_original_copy_tables (void);
 986 extern void free_original_copy_tables (void);
 987 extern void set_bb_original (basic_block, basic_block);
 988 extern basic_block get_bb_original (basic_block);
 989 extern void set_bb_copy (basic_block, basic_block);
 990 extern basic_block get_bb_copy (basic_block);
 991
 992 #include "cfghooks.h"
 993
 994 #endif /* GCC_BASIC_BLOCK_H */