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,
   3    2005, 2006, 2007, 2008 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 3, 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 COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #ifndef GCC_BASIC_BLOCK_H
  22 #define GCC_BASIC_BLOCK_H
  23
  24 #include "bitmap.h"
  25 #include "sbitmap.h"
  26 #include "varray.h"
  27 #include "partition.h"
  28 #include "hard-reg-set.h"
  29 #include "predict.h"
  30 #include "vec.h"
  31 #include "function.h"
  32
  33 /* Head of register set linked list.  */
  34 typedef bitmap_head regset_head;
  35
  36 /* A pointer to a regset_head.  */
  37 typedef bitmap regset;
  38
  39 /* Allocate a register set with oballoc.  */
  40 #define ALLOC_REG_SET(OBSTACK) BITMAP_ALLOC (OBSTACK)
  41
  42 /* Do any cleanup needed on a regset when it is no longer used.  */
  43 #define FREE_REG_SET(REGSET) BITMAP_FREE (REGSET)
  44
  45 /* Initialize a new regset.  */
  46 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, &reg_obstack)
  47
  48 /* Clear a register set by freeing up the linked list.  */
  49 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  50
  51 /* Copy a register set to another register set.  */
  52 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  53
  54 /* Compare two register sets.  */
  55 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  56
  57 /* `and' a register set with a second register set.  */
  58 #define AND_REG_SET(TO, FROM) bitmap_and_into (TO, FROM)
  59
  60 /* `and' the complement of a register set with a register set.  */
  61 #define AND_COMPL_REG_SET(TO, FROM) bitmap_and_compl_into (TO, FROM)
  62
  63 /* Inclusive or a register set with a second register set.  */
  64 #define IOR_REG_SET(TO, FROM) bitmap_ior_into (TO, FROM)
  65
  66 /* Exclusive or a register set with a second register set.  */
  67 #define XOR_REG_SET(TO, FROM) bitmap_xor_into (TO, FROM)
  68
  69 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  70 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  71   bitmap_ior_and_compl_into (TO, FROM1, FROM2)
  72
  73 /* Clear a single register in a register set.  */
  74 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  75
  76 /* Set a single register in a register set.  */
  77 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  78
  79 /* Return true if a register is set in a register set.  */
  80 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  81
  82 /* Copy the hard registers in a register set to the hard register set.  */
  83 extern void reg_set_to_hard_reg_set (HARD_REG_SET *, const_bitmap);
  84 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  85 do {                                                                    \
  86   CLEAR_HARD_REG_SET (TO);                                              \
  87   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  88 } while (0)
  89
  90 typedef bitmap_iterator reg_set_iterator;
  91
  92 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  93    register number and executing CODE for all registers that are set.  */
  94 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, RSI)     \
  95   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, RSI)
  96
  97 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  98    REGNUM to the register number and executing CODE for all registers that are
  99    set in the first regset and not set in the second.  */
 100 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
 101   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI)
 102
 103 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
 104    REGNUM to the register number and executing CODE for all registers that are
 105    set in both regsets.  */
 106 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, RSI) \
 107   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, RSI) \
 108
 109 /* Type we use to hold basic block counters.  Should be at least
 110    64bit.  Although a counter cannot be negative, we use a signed
 111    type, because erroneous negative counts can be generated when the
 112    flow graph is manipulated by various optimizations.  A signed type
 113    makes those easy to detect.  */
 114 typedef HOST_WIDEST_INT gcov_type;
 115
 116 /* Control flow edge information.  */
 117 struct edge_def GTY(())
 118 {
 119   /* The two blocks at the ends of the edge.  */
 120   struct basic_block_def *src;
 121   struct basic_block_def *dest;
 122
 123   /* Instructions queued on the edge.  */
 124   union edge_def_insns {
 125     tree GTY ((tag ("true"))) t;
 126     rtx GTY ((tag ("false"))) r;
 127   } GTY ((desc ("current_ir_type () == IR_GIMPLE"))) insns;
 128
 129   /* Auxiliary info specific to a pass.  */
 130   PTR GTY ((skip (""))) aux;
 131
 132   /* Location of any goto implicit in the edge, during tree-ssa.  */
 133   location_t goto_locus;
 134
 135   /* The index number corresponding to this edge in the edge vector
 136      dest->preds.  */
 137   unsigned int dest_idx;
 138
 139   int flags;                    /* see EDGE_* below  */
 140   int probability;              /* biased by REG_BR_PROB_BASE */
 141   gcov_type count;              /* Expected number of executions calculated
 142                                    in profile.c  */
 143 };
 144
 145 typedef struct edge_def *edge;
 146 typedef const struct edge_def *const_edge;
 147 DEF_VEC_P(edge);
 148 DEF_VEC_ALLOC_P(edge,gc);
 149 DEF_VEC_ALLOC_P(edge,heap);
 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
 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   /* The edges into and out of the block.  */
 217   VEC(edge,gc) *preds;
 218   VEC(edge,gc) *succs;
 219
 220   /* Auxiliary info specific to a pass.  */
 221   PTR GTY ((skip (""))) aux;
 222
 223   /* Innermost loop containing the block.  */
 224   struct loop *loop_father;
 225
 226   /* The dominance and postdominance information node.  */
 227   struct et_node * GTY ((skip (""))) dom[2];
 228
 229   /* Previous and next blocks in the chain.  */
 230   struct basic_block_def *prev_bb;
 231   struct basic_block_def *next_bb;
 232
 233   union basic_block_il_dependent {
 234       struct tree_bb_info * GTY ((tag ("0"))) tree;
 235       struct rtl_bb_info * GTY ((tag ("1"))) rtl;
 236     } GTY ((desc ("((%1.flags & BB_RTL) != 0)"))) il;
 237
 238   /* Expected number of executions: calculated in profile.c.  */
 239   gcov_type count;
 240
 241   /* The index of this block.  */
 242   int index;
 243
 244   /* The loop depth of this block.  */
 245   int loop_depth;
 246
 247   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 248   int frequency;
 249
 250   /* Various flags.  See BB_* below.  */
 251   int flags;
 252 };
 253
 254 struct rtl_bb_info GTY(())
 255 {
 256   /* The first and last insns of the block.  */
 257   rtx head_;
 258   rtx end_;
 259
 260   /* In CFGlayout mode points to insn notes/jumptables to be placed just before
 261      and after the block.   */
 262   rtx header;
 263   rtx footer;
 264
 265   /* This field is used by the bb-reorder and tracer passes.  */
 266   int visited;
 267 };
 268
 269 struct tree_bb_info GTY(())
 270 {
 271   /* Pointers to the first and last trees of the block.  */
 272   tree stmt_list;
 273
 274   /* Chain of PHI nodes for this block.  */
 275   tree phi_nodes;
 276 };
 277
 278 typedef struct basic_block_def *basic_block;
 279 typedef const struct basic_block_def *const_basic_block;
 280
 281 DEF_VEC_P(basic_block);
 282 DEF_VEC_ALLOC_P(basic_block,gc);
 283 DEF_VEC_ALLOC_P(basic_block,heap);
 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   /* Only set on blocks that have just been created by create_bb.  */
 298   BB_NEW = 1 << 0,
 299
 300   /* Set by find_unreachable_blocks.  Do not rely on this being set in any
 301      pass.  */
 302   BB_REACHABLE = 1 << 1,
 303
 304   /* Set for blocks in an irreducible loop by loop analysis.  */
 305   BB_IRREDUCIBLE_LOOP = 1 << 2,
 306
 307   /* Set on blocks that may actually not be single-entry single-exit block.  */
 308   BB_SUPERBLOCK = 1 << 3,
 309
 310   /* Set on basic blocks that the scheduler should not touch.  This is used
 311      by SMS to prevent other schedulers from messing with the loop schedule.  */
 312   BB_DISABLE_SCHEDULE = 1 << 4,
 313
 314   /* Set on blocks that should be put in a hot section.  */
 315   BB_HOT_PARTITION = 1 << 5,
 316
 317   /* Set on blocks that should be put in a cold section.  */
 318   BB_COLD_PARTITION = 1 << 6,
 319
 320   /* Set on block that was duplicated.  */
 321   BB_DUPLICATED = 1 << 7,
 322
 323   /* Set if the label at the top of this block is the target of a non-local goto.  */
 324   BB_NON_LOCAL_GOTO_TARGET = 1 << 8,
 325
 326   /* Set on blocks that are in RTL format.  */
 327   BB_RTL = 1 << 9 ,
 328
 329   /* Set on blocks that are forwarder blocks.
 330      Only used in cfgcleanup.c.  */
 331   BB_FORWARDER_BLOCK = 1 << 10,
 332
 333   /* Set on blocks that cannot be threaded through.
 334      Only used in cfgcleanup.c.  */
 335   BB_NONTHREADABLE_BLOCK = 1 << 11
 336 };
 337
 338 /* Dummy flag for convenience in the hot/cold partitioning code.  */
 339 #define BB_UNPARTITIONED        0
 340
 341 /* Partitions, to be used when partitioning hot and cold basic blocks into
 342    separate sections.  */
 343 #define BB_PARTITION(bb) ((bb)->flags & (BB_HOT_PARTITION|BB_COLD_PARTITION))
 344 #define BB_SET_PARTITION(bb, part) do {                                 \
 345   basic_block bb_ = (bb);                                               \
 346   bb_->flags = ((bb_->flags & ~(BB_HOT_PARTITION|BB_COLD_PARTITION))    \
 347                 | (part));                                              \
 348 } while (0)
 349
 350 #define BB_COPY_PARTITION(dstbb, srcbb) \
 351   BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb))
 352
 353 /* State of dominance information.  */
 354
 355 enum dom_state
 356 {
 357   DOM_NONE,             /* Not computed at all.  */
 358   DOM_NO_FAST_QUERY,    /* The data is OK, but the fast query data are not usable.  */
 359   DOM_OK                /* Everything is ok.  */
 360 };
 361
 362 /* A structure to group all the per-function control flow graph data.
 363    The x_* prefixing is necessary because otherwise references to the
 364    fields of this struct are interpreted as the defines for backward
 365    source compatibility following the definition of this struct.  */
 366 struct control_flow_graph GTY(())
 367 {
 368   /* Block pointers for the exit and entry of a function.
 369      These are always the head and tail of the basic block list.  */
 370   basic_block x_entry_block_ptr;
 371   basic_block x_exit_block_ptr;
 372
 373   /* Index by basic block number, get basic block struct info.  */
 374   VEC(basic_block,gc) *x_basic_block_info;
 375
 376   /* Number of basic blocks in this flow graph.  */
 377   int x_n_basic_blocks;
 378
 379   /* Number of edges in this flow graph.  */
 380   int x_n_edges;
 381
 382   /* The first free basic block number.  */
 383   int x_last_basic_block;
 384
 385   /* Mapping of labels to their associated blocks.  At present
 386      only used for the tree CFG.  */
 387   VEC(basic_block,gc) *x_label_to_block_map;
 388
 389   enum profile_status {
 390     PROFILE_ABSENT,
 391     PROFILE_GUESSED,
 392     PROFILE_READ
 393   } x_profile_status;
 394
 395   /* Whether the dominators and the postdominators are available.  */
 396   enum dom_state x_dom_computed[2];
 397
 398   /* Number of basic blocks in the dominance tree.  */
 399   unsigned x_n_bbs_in_dom_tree[2];
 400
 401   /* Maximal number of entities in the single jumptable.  Used to estimate
 402      final flowgraph size.  */
 403   int max_jumptable_ents;
 404
 405   /* UIDs for LABEL_DECLs.  */
 406   int last_label_uid;
 407 };
 408
 409 /* Defines for accessing the fields of the CFG structure for function FN.  */
 410 #define ENTRY_BLOCK_PTR_FOR_FUNCTION(FN)     ((FN)->cfg->x_entry_block_ptr)
 411 #define EXIT_BLOCK_PTR_FOR_FUNCTION(FN)      ((FN)->cfg->x_exit_block_ptr)
 412 #define basic_block_info_for_function(FN)    ((FN)->cfg->x_basic_block_info)
 413 #define n_basic_blocks_for_function(FN)      ((FN)->cfg->x_n_basic_blocks)
 414 #define n_edges_for_function(FN)             ((FN)->cfg->x_n_edges)
 415 #define last_basic_block_for_function(FN)    ((FN)->cfg->x_last_basic_block)
 416 #define label_to_block_map_for_function(FN)  ((FN)->cfg->x_label_to_block_map)
 417
 418 #define BASIC_BLOCK_FOR_FUNCTION(FN,N) \
 419   (VEC_index (basic_block, basic_block_info_for_function(FN), (N)))
 420
 421 /* Defines for textual backward source compatibility.  */
 422 #define ENTRY_BLOCK_PTR         (cfun->cfg->x_entry_block_ptr)
 423 #define EXIT_BLOCK_PTR          (cfun->cfg->x_exit_block_ptr)
 424 #define basic_block_info        (cfun->cfg->x_basic_block_info)
 425 #define n_basic_blocks          (cfun->cfg->x_n_basic_blocks)
 426 #define n_edges                 (cfun->cfg->x_n_edges)
 427 #define last_basic_block        (cfun->cfg->x_last_basic_block)
 428 #define label_to_block_map      (cfun->cfg->x_label_to_block_map)
 429 #define profile_status          (cfun->cfg->x_profile_status)
 430
 431 #define BASIC_BLOCK(N)          (VEC_index (basic_block, basic_block_info, (N)))
 432 #define SET_BASIC_BLOCK(N,BB)   (VEC_replace (basic_block, basic_block_info, (N), (BB)))
 433
 434 /* For iterating over basic blocks.  */
 435 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 436   for (BB = FROM; BB != TO; BB = BB->DIR)
 437
 438 #define FOR_EACH_BB_FN(BB, FN) \
 439   FOR_BB_BETWEEN (BB, (FN)->cfg->x_entry_block_ptr->next_bb, (FN)->cfg->x_exit_block_ptr, next_bb)
 440
 441 #define FOR_EACH_BB(BB) FOR_EACH_BB_FN (BB, cfun)
 442
 443 #define FOR_EACH_BB_REVERSE_FN(BB, FN) \
 444   FOR_BB_BETWEEN (BB, (FN)->cfg->x_exit_block_ptr->prev_bb, (FN)->cfg->x_entry_block_ptr, prev_bb)
 445
 446 #define FOR_EACH_BB_REVERSE(BB) FOR_EACH_BB_REVERSE_FN(BB, cfun)
 447
 448 /* For iterating over insns in basic block.  */
 449 #define FOR_BB_INSNS(BB, INSN)                  \
 450   for ((INSN) = BB_HEAD (BB);                   \
 451        (INSN) && (INSN) != NEXT_INSN (BB_END (BB));     \
 452        (INSN) = NEXT_INSN (INSN))
 453
 454 /* For iterating over insns in basic block when we might remove the
 455    current insn.  */
 456 #define FOR_BB_INSNS_SAFE(BB, INSN, CURR)                       \
 457   for ((INSN) = BB_HEAD (BB), (CURR) = (INSN) ? NEXT_INSN ((INSN)): NULL;       \
 458        (INSN) && (INSN) != NEXT_INSN (BB_END (BB));     \
 459        (INSN) = (CURR), (CURR) = (INSN) ? NEXT_INSN ((INSN)) : NULL)
 460
 461 #define FOR_BB_INSNS_REVERSE(BB, INSN)          \
 462   for ((INSN) = BB_END (BB);                    \
 463        (INSN) && (INSN) != PREV_INSN (BB_HEAD (BB));    \
 464        (INSN) = PREV_INSN (INSN))
 465
 466 #define FOR_BB_INSNS_REVERSE_SAFE(BB, INSN, CURR)       \
 467   for ((INSN) = BB_END (BB),(CURR) = (INSN) ? PREV_INSN ((INSN)) : NULL;        \
 468        (INSN) && (INSN) != PREV_INSN (BB_HEAD (BB));    \
 469        (INSN) = (CURR), (CURR) = (INSN) ? PREV_INSN ((INSN)) : NULL)
 470
 471 /* Cycles through _all_ basic blocks, even the fake ones (entry and
 472    exit block).  */
 473
 474 #define FOR_ALL_BB(BB) \
 475   for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
 476
 477 #define FOR_ALL_BB_FN(BB, FN) \
 478   for (BB = ENTRY_BLOCK_PTR_FOR_FUNCTION (FN); BB; BB = BB->next_bb)
 479
 480 extern bitmap_obstack reg_obstack;
 481
 482 \f
 483 /* Stuff for recording basic block info.  */
 484
 485 #define BB_HEAD(B)      (B)->il.rtl->head_
 486 #define BB_END(B)       (B)->il.rtl->end_
 487
 488 /* Special block numbers [markers] for entry and exit.  */
 489 #define ENTRY_BLOCK (0)
 490 #define EXIT_BLOCK (1)
 491
 492 /* The two blocks that are always in the cfg.  */
 493 #define NUM_FIXED_BLOCKS (2)
 494
 495
 496 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 497 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 498
 499 extern void compute_bb_for_insn (void);
 500 extern unsigned int free_bb_for_insn (void);
 501 extern void update_bb_for_insn (basic_block);
 502
 503 extern void insert_insn_on_edge (rtx, edge);
 504 basic_block split_edge_and_insert (edge, rtx);
 505
 506 extern void commit_edge_insertions (void);
 507
 508 extern void remove_fake_edges (void);
 509 extern void remove_fake_exit_edges (void);
 510 extern void add_noreturn_fake_exit_edges (void);
 511 extern void connect_infinite_loops_to_exit (void);
 512 extern edge unchecked_make_edge (basic_block, basic_block, int);
 513 extern edge cached_make_edge (sbitmap, basic_block, basic_block, int);
 514 extern edge make_edge (basic_block, basic_block, int);
 515 extern edge make_single_succ_edge (basic_block, basic_block, int);
 516 extern void remove_edge_raw (edge);
 517 extern void redirect_edge_succ (edge, basic_block);
 518 extern edge redirect_edge_succ_nodup (edge, basic_block);
 519 extern void redirect_edge_pred (edge, basic_block);
 520 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
 521 extern void clear_bb_flags (void);
 522 extern int post_order_compute (int *, bool, bool);
 523 extern int inverted_post_order_compute (int *);
 524 extern int pre_and_rev_post_order_compute (int *, int *, bool);
 525 extern int dfs_enumerate_from (basic_block, int,
 526                                bool (*)(const_basic_block, const void *),
 527                                basic_block *, int, const void *);
 528 extern void compute_dominance_frontiers (bitmap *);
 529 extern void dump_bb_info (basic_block, bool, bool, int, const char *, FILE *);
 530 extern void dump_edge_info (FILE *, edge, int);
 531 extern void brief_dump_cfg (FILE *);
 532 extern void clear_edges (void);
 533 extern void scale_bbs_frequencies_int (basic_block *, int, int, int);
 534 extern void scale_bbs_frequencies_gcov_type (basic_block *, int, gcov_type,
 535                                              gcov_type);
 536
 537 /* Structure to group all of the information to process IF-THEN and
 538    IF-THEN-ELSE blocks for the conditional execution support.  This
 539    needs to be in a public file in case the IFCVT macros call
 540    functions passing the ce_if_block data structure.  */
 541
 542 typedef struct ce_if_block
 543 {
 544   basic_block test_bb;                  /* First test block.  */
 545   basic_block then_bb;                  /* THEN block.  */
 546   basic_block else_bb;                  /* ELSE block or NULL.  */
 547   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 548   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 549   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 550   int num_and_and_blocks;               /* # of && blocks.  */
 551   int num_or_or_blocks;                 /* # of || blocks.  */
 552   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 553   int and_and_p;                        /* Complex test is &&.  */
 554   int num_then_insns;                   /* # of insns in THEN block.  */
 555   int num_else_insns;                   /* # of insns in ELSE block.  */
 556   int pass;                             /* Pass number.  */
 557
 558 #ifdef IFCVT_EXTRA_FIELDS
 559   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 560 #endif
 561
 562 } ce_if_block_t;
 563
 564 /* This structure maintains an edge list vector.  */
 565 struct edge_list
 566 {
 567   int num_blocks;
 568   int num_edges;
 569   edge *index_to_edge;
 570 };
 571
 572 /* The base value for branch probability notes and edge probabilities.  */
 573 #define REG_BR_PROB_BASE  10000
 574
 575 /* This is the value which indicates no edge is present.  */
 576 #define EDGE_INDEX_NO_EDGE      -1
 577
 578 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 579    if there is no edge between the 2 basic blocks.  */
 580 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 581
 582 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 583    block which is either the pred or succ end of the indexed edge.  */
 584 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 585 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 586
 587 /* INDEX_EDGE returns a pointer to the edge.  */
 588 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 589
 590 /* Number of edges in the compressed edge list.  */
 591 #define NUM_EDGES(el)                   ((el)->num_edges)
 592
 593 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 594 #define FALLTHRU_EDGE(bb)               (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 595                                          ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
 596
 597 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 598 #define BRANCH_EDGE(bb)                 (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 599                                          ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
 600
 601 /* Return expected execution frequency of the edge E.  */
 602 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 603                                           * (e)->probability \
 604                                           + REG_BR_PROB_BASE / 2) \
 605                                          / REG_BR_PROB_BASE)
 606
 607 /* Return nonzero if edge is critical.  */
 608 #define EDGE_CRITICAL_P(e)              (EDGE_COUNT ((e)->src->succs) >= 2 \
 609                                          && EDGE_COUNT ((e)->dest->preds) >= 2)
 610
 611 #define EDGE_COUNT(ev)                  VEC_length (edge, (ev))
 612 #define EDGE_I(ev,i)                    VEC_index  (edge, (ev), (i))
 613 #define EDGE_PRED(bb,i)                 VEC_index  (edge, (bb)->preds, (i))
 614 #define EDGE_SUCC(bb,i)                 VEC_index  (edge, (bb)->succs, (i))
 615
 616 /* Returns true if BB has precisely one successor.  */
 617
 618 static inline bool
 619 single_succ_p (const_basic_block bb)
 620 {
 621   return EDGE_COUNT (bb->succs) == 1;
 622 }
 623
 624 /* Returns true if BB has precisely one predecessor.  */
 625
 626 static inline bool
 627 single_pred_p (const_basic_block bb)
 628 {
 629   return EDGE_COUNT (bb->preds) == 1;
 630 }
 631
 632 /* Returns the single successor edge of basic block BB.  Aborts if
 633    BB does not have exactly one successor.  */
 634
 635 static inline edge
 636 single_succ_edge (const_basic_block bb)
 637 {
 638   gcc_assert (single_succ_p (bb));
 639   return EDGE_SUCC (bb, 0);
 640 }
 641
 642 /* Returns the single predecessor edge of basic block BB.  Aborts
 643    if BB does not have exactly one predecessor.  */
 644
 645 static inline edge
 646 single_pred_edge (const_basic_block bb)
 647 {
 648   gcc_assert (single_pred_p (bb));
 649   return EDGE_PRED (bb, 0);
 650 }
 651
 652 /* Returns the single successor block of basic block BB.  Aborts
 653    if BB does not have exactly one successor.  */
 654
 655 static inline basic_block
 656 single_succ (const_basic_block bb)
 657 {
 658   return single_succ_edge (bb)->dest;
 659 }
 660
 661 /* Returns the single predecessor block of basic block BB.  Aborts
 662    if BB does not have exactly one predecessor.*/
 663
 664 static inline basic_block
 665 single_pred (const_basic_block bb)
 666 {
 667   return single_pred_edge (bb)->src;
 668 }
 669
 670 /* Iterator object for edges.  */
 671
 672 typedef struct {
 673   unsigned index;
 674   VEC(edge,gc) **container;
 675 } edge_iterator;
 676
 677 static inline VEC(edge,gc) *
 678 ei_container (edge_iterator i)
 679 {
 680   gcc_assert (i.container);
 681   return *i.container;
 682 }
 683
 684 #define ei_start(iter) ei_start_1 (&(iter))
 685 #define ei_last(iter) ei_last_1 (&(iter))
 686
 687 /* Return an iterator pointing to the start of an edge vector.  */
 688 static inline edge_iterator
 689 ei_start_1 (VEC(edge,gc) **ev)
 690 {
 691   edge_iterator i;
 692
 693   i.index = 0;
 694   i.container = ev;
 695
 696   return i;
 697 }
 698
 699 /* Return an iterator pointing to the last element of an edge
 700    vector.  */
 701 static inline edge_iterator
 702 ei_last_1 (VEC(edge,gc) **ev)
 703 {
 704   edge_iterator i;
 705
 706   i.index = EDGE_COUNT (*ev) - 1;
 707   i.container = ev;
 708
 709   return i;
 710 }
 711
 712 /* Is the iterator `i' at the end of the sequence?  */
 713 static inline bool
 714 ei_end_p (edge_iterator i)
 715 {
 716   return (i.index == EDGE_COUNT (ei_container (i)));
 717 }
 718
 719 /* Is the iterator `i' at one position before the end of the
 720    sequence?  */
 721 static inline bool
 722 ei_one_before_end_p (edge_iterator i)
 723 {
 724   return (i.index + 1 == EDGE_COUNT (ei_container (i)));
 725 }
 726
 727 /* Advance the iterator to the next element.  */
 728 static inline void
 729 ei_next (edge_iterator *i)
 730 {
 731   gcc_assert (i->index < EDGE_COUNT (ei_container (*i)));
 732   i->index++;
 733 }
 734
 735 /* Move the iterator to the previous element.  */
 736 static inline void
 737 ei_prev (edge_iterator *i)
 738 {
 739   gcc_assert (i->index > 0);
 740   i->index--;
 741 }
 742
 743 /* Return the edge pointed to by the iterator `i'.  */
 744 static inline edge
 745 ei_edge (edge_iterator i)
 746 {
 747   return EDGE_I (ei_container (i), i.index);
 748 }
 749
 750 /* Return an edge pointed to by the iterator.  Do it safely so that
 751    NULL is returned when the iterator is pointing at the end of the
 752    sequence.  */
 753 static inline edge
 754 ei_safe_edge (edge_iterator i)
 755 {
 756   return !ei_end_p (i) ? ei_edge (i) : NULL;
 757 }
 758
 759 /* Return 1 if we should continue to iterate.  Return 0 otherwise.
 760    *Edge P is set to the next edge if we are to continue to iterate
 761    and NULL otherwise.  */
 762
 763 static inline bool
 764 ei_cond (edge_iterator ei, edge *p)
 765 {
 766   if (!ei_end_p (ei))
 767     {
 768       *p = ei_edge (ei);
 769       return 1;
 770     }
 771   else
 772     {
 773       *p = NULL;
 774       return 0;
 775     }
 776 }
 777
 778 /* This macro serves as a convenient way to iterate each edge in a
 779    vector of predecessor or successor edges.  It must not be used when
 780    an element might be removed during the traversal, otherwise
 781    elements will be missed.  Instead, use a for-loop like that shown
 782    in the following pseudo-code:
 783
 784    FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 785      {
 786         IF (e != taken_edge)
 787           remove_edge (e);
 788         ELSE
 789           ei_next (&ei);
 790      }
 791 */
 792
 793 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC)       \
 794   for ((ITER) = ei_start ((EDGE_VEC));          \
 795        ei_cond ((ITER), &(EDGE));               \
 796        ei_next (&(ITER)))
 797
 798 struct edge_list * create_edge_list (void);
 799 void free_edge_list (struct edge_list *);
 800 void print_edge_list (FILE *, struct edge_list *);
 801 void verify_edge_list (FILE *, struct edge_list *);
 802 int find_edge_index (struct edge_list *, basic_block, basic_block);
 803 edge find_edge (basic_block, basic_block);
 804
 805 #define CLEANUP_EXPENSIVE       1       /* Do relatively expensive optimizations
 806                                            except for edge forwarding */
 807 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 808 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 809                                            to care REG_DEAD notes.  */
 810 #define CLEANUP_THREADING       8       /* Do jump threading.  */
 811 #define CLEANUP_NO_INSN_DEL     16      /* Do not try to delete trivially dead
 812                                            insns.  */
 813 #define CLEANUP_CFGLAYOUT       32      /* Do cleanup in cfglayout mode.  */
 814
 815 /* In lcm.c */
 816 extern struct edge_list *pre_edge_lcm (int, sbitmap *, sbitmap *,
 817                                        sbitmap *, sbitmap *, sbitmap **,
 818                                        sbitmap **);
 819 extern struct edge_list *pre_edge_rev_lcm (int, sbitmap *,
 820                                            sbitmap *, sbitmap *,
 821                                            sbitmap *, sbitmap **,
 822                                            sbitmap **);
 823 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
 824
 825 /* In predict.c */
 826 extern bool maybe_hot_bb_p (const_basic_block);
 827 extern bool probably_cold_bb_p (const_basic_block);
 828 extern bool probably_never_executed_bb_p (const_basic_block);
 829 extern bool tree_predicted_by_p (const_basic_block, enum br_predictor);
 830 extern bool rtl_predicted_by_p (const_basic_block, enum br_predictor);
 831 extern void tree_predict_edge (edge, enum br_predictor, int);
 832 extern void rtl_predict_edge (edge, enum br_predictor, int);
 833 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
 834 extern void guess_outgoing_edge_probabilities (basic_block);
 835 extern void remove_predictions_associated_with_edge (edge);
 836 extern bool edge_probability_reliable_p (const_edge);
 837 extern bool br_prob_note_reliable_p (const_rtx);
 838
 839 /* In cfg.c  */
 840 extern void dump_regset (regset, FILE *);
 841 extern void debug_regset (regset);
 842 extern void init_flow (void);
 843 extern void debug_bb (basic_block);
 844 extern basic_block debug_bb_n (int);
 845 extern void dump_regset (regset, FILE *);
 846 extern void debug_regset (regset);
 847 extern void expunge_block (basic_block);
 848 extern void link_block (basic_block, basic_block);
 849 extern void unlink_block (basic_block);
 850 extern void compact_blocks (void);
 851 extern basic_block alloc_block (void);
 852 extern void alloc_aux_for_block (basic_block, int);
 853 extern void alloc_aux_for_blocks (int);
 854 extern void clear_aux_for_blocks (void);
 855 extern void free_aux_for_blocks (void);
 856 extern void alloc_aux_for_edge (edge, int);
 857 extern void alloc_aux_for_edges (int);
 858 extern void clear_aux_for_edges (void);
 859 extern void free_aux_for_edges (void);
 860
 861 /* In cfganal.c  */
 862 extern void find_unreachable_blocks (void);
 863 extern bool forwarder_block_p (const_basic_block);
 864 extern bool can_fallthru (basic_block, basic_block);
 865 extern bool could_fall_through (basic_block, basic_block);
 866 extern void flow_nodes_print (const char *, const_sbitmap, FILE *);
 867 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
 868
 869 /* In cfgrtl.c  */
 870 extern basic_block force_nonfallthru (edge);
 871 extern rtx block_label (basic_block);
 872 extern bool purge_all_dead_edges (void);
 873 extern bool purge_dead_edges (basic_block);
 874
 875 /* In cfgbuild.c.  */
 876 extern void find_many_sub_basic_blocks (sbitmap);
 877 extern void rtl_make_eh_edge (sbitmap, basic_block, rtx);
 878 extern void find_basic_blocks (rtx);
 879
 880 /* In cfgcleanup.c.  */
 881 extern bool cleanup_cfg (int);
 882 extern bool delete_unreachable_blocks (void);
 883
 884 extern bool mark_dfs_back_edges (void);
 885 extern void set_edge_can_fallthru_flag (void);
 886 extern void update_br_prob_note (basic_block);
 887 extern void fixup_abnormal_edges (void);
 888 extern bool inside_basic_block_p (const_rtx);
 889 extern bool control_flow_insn_p (const_rtx);
 890 extern rtx get_last_bb_insn (basic_block);
 891
 892 /* In bb-reorder.c */
 893 extern void reorder_basic_blocks (void);
 894
 895 /* In dominance.c */
 896
 897 enum cdi_direction
 898 {
 899   CDI_DOMINATORS = 1,
 900   CDI_POST_DOMINATORS = 2
 901 };
 902
 903 extern enum dom_state dom_info_state (enum cdi_direction);
 904 extern void set_dom_info_availability (enum cdi_direction, enum dom_state);
 905 extern bool dom_info_available_p (enum cdi_direction);
 906 extern void calculate_dominance_info (enum cdi_direction);
 907 extern void free_dominance_info (enum cdi_direction);
 908 extern basic_block nearest_common_dominator (enum cdi_direction,
 909                                              basic_block, basic_block);
 910 extern basic_block nearest_common_dominator_for_set (enum cdi_direction,
 911                                                      bitmap);
 912 extern void set_immediate_dominator (enum cdi_direction, basic_block,
 913                                      basic_block);
 914 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
 915 extern bool dominated_by_p (enum cdi_direction, const_basic_block, const_basic_block);
 916 extern VEC (basic_block, heap) *get_dominated_by (enum cdi_direction, basic_block);
 917 extern VEC (basic_block, heap) *get_dominated_by_region (enum cdi_direction,
 918                                                          basic_block *,
 919                                                          unsigned);
 920 extern void add_to_dominance_info (enum cdi_direction, basic_block);
 921 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
 922 basic_block recompute_dominator (enum cdi_direction, basic_block);
 923 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
 924                                            basic_block);
 925 extern void iterate_fix_dominators (enum cdi_direction,
 926                                     VEC (basic_block, heap) *, bool);
 927 extern void verify_dominators (enum cdi_direction);
 928 extern basic_block first_dom_son (enum cdi_direction, basic_block);
 929 extern basic_block next_dom_son (enum cdi_direction, basic_block);
 930 unsigned bb_dom_dfs_in (enum cdi_direction, basic_block);
 931 unsigned bb_dom_dfs_out (enum cdi_direction, basic_block);
 932
 933 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
 934 extern void break_superblocks (void);
 935 extern void relink_block_chain (bool);
 936 extern void check_bb_profile (basic_block, FILE *);
 937 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
 938 extern void init_rtl_bb_info (basic_block);
 939
 940 extern void initialize_original_copy_tables (void);
 941 extern void free_original_copy_tables (void);
 942 extern void set_bb_original (basic_block, basic_block);
 943 extern basic_block get_bb_original (basic_block);
 944 extern void set_bb_copy (basic_block, basic_block);
 945 extern basic_block get_bb_copy (basic_block);
 946 void set_loop_copy (struct loop *, struct loop *);
 947 struct loop *get_loop_copy (struct loop *);
 948
 949
 950 extern rtx insert_insn_end_bb_new (rtx, basic_block);
 951
 952 #include "cfghooks.h"
 953
 954 /* Return true when one of the predecessor edges of BB is marked with EDGE_EH.  */
 955 static inline bool
 956 bb_has_eh_pred (basic_block bb)
 957 {
 958   edge e;
 959   edge_iterator ei;
 960
 961   FOR_EACH_EDGE (e, ei, bb->preds)
 962     {
 963       if (e->flags & EDGE_EH)
 964         return true;
 965     }
 966   return false;
 967 }
 968
 969 /* Return true when one of the predecessor edges of BB is marked with EDGE_ABNORMAL.  */
 970 static inline bool
 971 bb_has_abnormal_pred (basic_block bb)
 972 {
 973   edge e;
 974   edge_iterator ei;
 975
 976   FOR_EACH_EDGE (e, ei, bb->preds)
 977     {
 978       if (e->flags & EDGE_ABNORMAL)
 979         return true;
 980     }
 981   return false;
 982 }
 983
 984 /* In cfgloopmanip.c.  */
 985 extern edge mfb_kj_edge;
 986 bool mfb_keep_just (edge);
 987
 988 #endif /* GCC_BASIC_BLOCK_H */