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    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #ifndef GCC_BASIC_BLOCK_H
  23 #define GCC_BASIC_BLOCK_H
  24
  25 #include "bitmap.h"
  26 #include "sbitmap.h"
  27 #include "varray.h"
  28 #include "partition.h"
  29 #include "hard-reg-set.h"
  30 #include "predict.h"
  31 #include "vec.h"
  32 #include "errors.h"
  33
  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_GC_P(edge);
 148
 149 #define EDGE_FALLTHRU           1       /* 'Straight line' flow */
 150 #define EDGE_ABNORMAL           2       /* Strange flow, like computed
 151                                            label, or eh */
 152 #define EDGE_ABNORMAL_CALL      4       /* Call with abnormal exit
 153                                            like an exception, or sibcall */
 154 #define EDGE_EH                 8       /* Exception throw */
 155 #define EDGE_FAKE               16      /* Not a real edge (profile.c) */
 156 #define EDGE_DFS_BACK           32      /* A backwards edge */
 157 #define EDGE_CAN_FALLTHRU       64      /* Candidate for straight line
 158                                            flow.  */
 159 #define EDGE_IRREDUCIBLE_LOOP   128     /* Part of irreducible loop.  */
 160 #define EDGE_SIBCALL            256     /* Edge from sibcall to exit.  */
 161 #define EDGE_LOOP_EXIT          512     /* Exit of a loop.  */
 162 #define EDGE_TRUE_VALUE         1024    /* Edge taken when controlling
 163                                            predicate is nonzero.  */
 164 #define EDGE_FALSE_VALUE        2048    /* Edge taken when controlling
 165                                            predicate is zero.  */
 166 #define EDGE_EXECUTABLE         4096    /* Edge is executable.  Only
 167                                            valid during SSA-CCP.  */
 168 #define EDGE_CROSSING           8192    /* Edge crosses between hot
 169                                            and cold sections, when we
 170                                            do partitioning.  */
 171 #define EDGE_ALL_FLAGS         16383
 172
 173 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 174
 175 /* Counter summary from the last set of coverage counts read by
 176    profile.c.  */
 177 extern const struct gcov_ctr_summary *profile_info;
 178
 179 /* Declared in cfgloop.h.  */
 180 struct loop;
 181 struct loops;
 182
 183 /* Declared in tree-flow.h.  */
 184 struct bb_ann_d;
 185
 186 /* A basic block is a sequence of instructions with only entry and
 187    only one exit.  If any one of the instructions are executed, they
 188    will all be executed, and in sequence from first to last.
 189
 190    There may be COND_EXEC instructions in the basic block.  The
 191    COND_EXEC *instructions* will be executed -- but if the condition
 192    is false the conditionally executed *expressions* will of course
 193    not be executed.  We don't consider the conditionally executed
 194    expression (which might have side-effects) to be in a separate
 195    basic block because the program counter will always be at the same
 196    location after the COND_EXEC instruction, regardless of whether the
 197    condition is true or not.
 198
 199    Basic blocks need not start with a label nor end with a jump insn.
 200    For example, a previous basic block may just "conditionally fall"
 201    into the succeeding basic block, and the last basic block need not
 202    end with a jump insn.  Block 0 is a descendant of the entry block.
 203
 204    A basic block beginning with two labels cannot have notes between
 205    the labels.
 206
 207    Data for jump tables are stored in jump_insns that occur in no
 208    basic block even though these insns can follow or precede insns in
 209    basic blocks.  */
 210
 211 /* Basic block information indexed by block number.  */
 212 struct basic_block_def GTY((chain_next ("%h.next_bb"), chain_prev ("%h.prev_bb")))
 213 {
 214   /* The first and last insns of the block.  */
 215   rtx head_;
 216   rtx end_;
 217
 218   /* Pointers to the first and last trees of the block.  */
 219   tree stmt_list;
 220
 221   /* The edges into and out of the block.  */
 222   VEC(edge) *preds;
 223   VEC(edge) *succs;
 224
 225   /* The registers that are live on entry to this block.  */
 226   bitmap GTY ((skip (""))) global_live_at_start;
 227
 228   /* The registers that are live on exit from this block.  */
 229   bitmap GTY ((skip (""))) global_live_at_end;
 230
 231   /* Auxiliary info specific to a pass.  */
 232   PTR GTY ((skip (""))) aux;
 233
 234   /* Innermost loop containing the block.  */
 235   struct loop * GTY ((skip (""))) loop_father;
 236
 237   /* The dominance and postdominance information node.  */
 238   struct et_node * GTY ((skip (""))) dom[2];
 239
 240   /* Previous and next blocks in the chain.  */
 241   struct basic_block_def *prev_bb;
 242   struct basic_block_def *next_bb;
 243
 244   /* The data used by basic block copying and reordering functions.  */
 245   struct reorder_block_def * GTY ((skip (""))) rbi;
 246
 247   /* Annotations used at the tree level.  */
 248   struct bb_ann_d *tree_annotations;
 249
 250   /* Expected number of executions: calculated in profile.c.  */
 251   gcov_type count;
 252
 253   /* The index of this block.  */
 254   int index;
 255
 256   /* The loop depth of this block.  */
 257   int loop_depth;
 258
 259   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 260   int frequency;
 261
 262   /* Various flags.  See BB_* below.  */
 263   int flags;
 264 };
 265
 266 typedef struct basic_block_def *basic_block;
 267
 268 /* Structure to hold information about the blocks during reordering and
 269    copying.  */
 270
 271 typedef struct reorder_block_def
 272 {
 273   rtx header;
 274   rtx footer;
 275   basic_block next;
 276   basic_block original;
 277   /* Used by loop copying.  */
 278   basic_block copy;
 279   int duplicated;
 280   int copy_number;
 281
 282   /* These fields are used by bb-reorder pass.  */
 283   int visited;
 284 } *reorder_block_def_p;
 285
 286 #define BB_FREQ_MAX 10000
 287
 288 /* Masks for basic_block.flags.  */
 289 #define BB_DIRTY                1
 290 #define BB_NEW                  2
 291 #define BB_REACHABLE            4
 292 #define BB_VISITED              8
 293 #define BB_IRREDUCIBLE_LOOP     16
 294 #define BB_SUPERBLOCK           32
 295 #define BB_DISABLE_SCHEDULE     64
 296
 297 #define BB_HOT_PARTITION        128
 298 #define BB_COLD_PARTITION       256
 299 #define BB_UNPARTITIONED        0
 300
 301 /* Partitions, to be used when partitioning hot and cold basic blocks into
 302    separate sections.  */
 303 #define BB_PARTITION(bb) ((bb)->flags & (BB_HOT_PARTITION|BB_COLD_PARTITION))
 304 #define BB_SET_PARTITION(bb, part) do {                                 \
 305   basic_block bb_ = (bb);                                               \
 306   bb_->flags = ((bb_->flags & ~(BB_HOT_PARTITION|BB_COLD_PARTITION))    \
 307                 | (part));                                              \
 308 } while (0)
 309
 310 #define BB_COPY_PARTITION(dstbb, srcbb) \
 311   BB_SET_PARTITION (dstbb, BB_PARTITION (srcbb))
 312
 313 /* Number of basic blocks in the current function.  */
 314
 315 extern int n_basic_blocks;
 316
 317 /* First free basic block number.  */
 318
 319 extern int last_basic_block;
 320
 321 /* Number of edges in the current function.  */
 322
 323 extern int n_edges;
 324
 325 /* Signalize the status of profile information in the CFG.  */
 326 extern enum profile_status
 327 {
 328   PROFILE_ABSENT,
 329   PROFILE_GUESSED,
 330   PROFILE_READ
 331 } profile_status;
 332
 333 /* Index by basic block number, get basic block struct info.  */
 334
 335 extern GTY(()) varray_type basic_block_info;
 336
 337 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 338
 339 /* For iterating over basic blocks.  */
 340 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 341   for (BB = FROM; BB != TO; BB = BB->DIR)
 342
 343 #define FOR_EACH_BB(BB) \
 344   FOR_BB_BETWEEN (BB, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
 345
 346 #define FOR_EACH_BB_REVERSE(BB) \
 347   FOR_BB_BETWEEN (BB, EXIT_BLOCK_PTR->prev_bb, ENTRY_BLOCK_PTR, prev_bb)
 348
 349 /* For iterating over insns in basic block.  */
 350 #define FOR_BB_INSNS(BB, INSN)                  \
 351   for ((INSN) = BB_HEAD (BB);                   \
 352        (INSN) != NEXT_INSN (BB_END (BB));       \
 353        (INSN) = NEXT_INSN (INSN))
 354
 355 #define FOR_BB_INSNS_REVERSE(BB, INSN)          \
 356   for ((INSN) = BB_END (BB);                    \
 357        (INSN) != PREV_INSN (BB_HEAD (BB));      \
 358        (INSN) = PREV_INSN (INSN))
 359
 360 /* Cycles through _all_ basic blocks, even the fake ones (entry and
 361    exit block).  */
 362
 363 #define FOR_ALL_BB(BB) \
 364   for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
 365
 366 /* What registers are live at the setjmp call.  */
 367
 368 extern regset regs_live_at_setjmp;
 369
 370 /* Special labels found during CFG build.  */
 371
 372 extern GTY(()) rtx label_value_list;
 373
 374 extern bitmap_obstack reg_obstack;
 375
 376 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 377    If the value is REG_BLOCK_GLOBAL (-2),
 378    it means (REG n) is used in more than one basic block.
 379    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 380    This information remains valid for the rest of the compilation
 381    of the current function; it is used to control register allocation.  */
 382
 383 #define REG_BLOCK_UNKNOWN -1
 384 #define REG_BLOCK_GLOBAL -2
 385
 386 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 387 \f
 388 /* Stuff for recording basic block info.  */
 389
 390 #define BB_HEAD(B)      (B)->head_
 391 #define BB_END(B)       (B)->end_
 392
 393 /* Special block numbers [markers] for entry and exit.  */
 394 #define ENTRY_BLOCK (-1)
 395 #define EXIT_BLOCK (-2)
 396
 397 /* Special block number not valid for any block.  */
 398 #define INVALID_BLOCK (-3)
 399
 400 /* Similarly, block pointers for the edge list.  */
 401 extern GTY(()) basic_block ENTRY_BLOCK_PTR;
 402 extern GTY(()) basic_block EXIT_BLOCK_PTR;
 403
 404 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 405 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 406
 407 extern void compute_bb_for_insn (void);
 408 extern void free_bb_for_insn (void);
 409 extern void update_bb_for_insn (basic_block);
 410
 411 extern void free_basic_block_vars (void);
 412
 413 extern void insert_insn_on_edge (rtx, edge);
 414 bool safe_insert_insn_on_edge (rtx, edge);
 415
 416 extern void commit_edge_insertions (void);
 417 extern void commit_edge_insertions_watch_calls (void);
 418
 419 extern void remove_fake_edges (void);
 420 extern void remove_fake_exit_edges (void);
 421 extern void add_noreturn_fake_exit_edges (void);
 422 extern void connect_infinite_loops_to_exit (void);
 423 extern edge unchecked_make_edge (basic_block, basic_block, int);
 424 extern edge cached_make_edge (sbitmap *, basic_block, basic_block, int);
 425 extern edge make_edge (basic_block, basic_block, int);
 426 extern edge make_single_succ_edge (basic_block, basic_block, int);
 427 extern void remove_edge (edge);
 428 extern void redirect_edge_succ (edge, basic_block);
 429 extern edge redirect_edge_succ_nodup (edge, basic_block);
 430 extern void redirect_edge_pred (edge, basic_block);
 431 extern basic_block create_basic_block_structure (rtx, rtx, rtx, basic_block);
 432 extern void clear_bb_flags (void);
 433 extern void flow_reverse_top_sort_order_compute (int *);
 434 extern int flow_depth_first_order_compute (int *, int *);
 435 extern int dfs_enumerate_from (basic_block, int,
 436                                bool (*)(basic_block, void *),
 437                                basic_block *, int, void *);
 438 extern void compute_dominance_frontiers (bitmap *);
 439 extern void dump_edge_info (FILE *, edge, int);
 440 extern void brief_dump_cfg (FILE *);
 441 extern void clear_edges (void);
 442 extern rtx first_insn_after_basic_block_note (basic_block);
 443
 444 /* Structure to group all of the information to process IF-THEN and
 445    IF-THEN-ELSE blocks for the conditional execution support.  This
 446    needs to be in a public file in case the IFCVT macros call
 447    functions passing the ce_if_block data structure.  */
 448
 449 typedef struct ce_if_block
 450 {
 451   basic_block test_bb;                  /* First test block.  */
 452   basic_block then_bb;                  /* THEN block.  */
 453   basic_block else_bb;                  /* ELSE block or NULL.  */
 454   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 455   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 456   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 457   int num_and_and_blocks;               /* # of && blocks.  */
 458   int num_or_or_blocks;                 /* # of || blocks.  */
 459   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 460   int and_and_p;                        /* Complex test is &&.  */
 461   int num_then_insns;                   /* # of insns in THEN block.  */
 462   int num_else_insns;                   /* # of insns in ELSE block.  */
 463   int pass;                             /* Pass number.  */
 464
 465 #ifdef IFCVT_EXTRA_FIELDS
 466   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 467 #endif
 468
 469 } ce_if_block_t;
 470
 471 /* This structure maintains an edge list vector.  */
 472 struct edge_list
 473 {
 474   int num_blocks;
 475   int num_edges;
 476   edge *index_to_edge;
 477 };
 478
 479 /* This is the value which indicates no edge is present.  */
 480 #define EDGE_INDEX_NO_EDGE      -1
 481
 482 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 483    if there is no edge between the 2 basic blocks.  */
 484 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 485
 486 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 487    block which is either the pred or succ end of the indexed edge.  */
 488 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 489 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 490
 491 /* INDEX_EDGE returns a pointer to the edge.  */
 492 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 493
 494 /* Number of edges in the compressed edge list.  */
 495 #define NUM_EDGES(el)                   ((el)->num_edges)
 496
 497 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 498 #define FALLTHRU_EDGE(bb)               (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 499                                          ? EDGE_SUCC ((bb), 0) : EDGE_SUCC ((bb), 1))
 500
 501 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 502 #define BRANCH_EDGE(bb)                 (EDGE_SUCC ((bb), 0)->flags & EDGE_FALLTHRU \
 503                                          ? EDGE_SUCC ((bb), 1) : EDGE_SUCC ((bb), 0))
 504
 505 /* Return expected execution frequency of the edge E.  */
 506 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 507                                           * (e)->probability \
 508                                           + REG_BR_PROB_BASE / 2) \
 509                                          / REG_BR_PROB_BASE)
 510
 511 /* Return nonzero if edge is critical.  */
 512 #define EDGE_CRITICAL_P(e)              (EDGE_COUNT ((e)->src->succs) >= 2 \
 513                                          && EDGE_COUNT ((e)->dest->preds) >= 2)
 514
 515 #define EDGE_COUNT(ev)                  VEC_length (edge, (ev))
 516 #define EDGE_I(ev,i)                    VEC_index  (edge, (ev), (i))
 517 #define EDGE_PRED(bb,i)                 VEC_index  (edge, (bb)->preds, (i))
 518 #define EDGE_SUCC(bb,i)                 VEC_index  (edge, (bb)->succs, (i))
 519
 520 /* Iterator object for edges.  */
 521
 522 typedef struct {
 523   unsigned index;
 524   VEC(edge) **container;
 525 } edge_iterator;
 526
 527 static inline VEC(edge) *
 528 ei_container (edge_iterator i)
 529 {
 530   gcc_assert (i.container);
 531   return *i.container;
 532 }
 533
 534 #define ei_start(iter) ei_start_1 (&(iter))
 535 #define ei_last(iter) ei_last_1 (&(iter))
 536
 537 /* Return an iterator pointing to the start of an edge vector.  */
 538 static inline edge_iterator
 539 ei_start_1 (VEC(edge) **ev)
 540 {
 541   edge_iterator i;
 542
 543   i.index = 0;
 544   i.container = ev;
 545
 546   return i;
 547 }
 548
 549 /* Return an iterator pointing to the last element of an edge
 550    vector.  */
 551 static inline edge_iterator
 552 ei_last_1 (VEC(edge) **ev)
 553 {
 554   edge_iterator i;
 555
 556   i.index = EDGE_COUNT (*ev) - 1;
 557   i.container = ev;
 558
 559   return i;
 560 }
 561
 562 /* Is the iterator `i' at the end of the sequence?  */
 563 static inline bool
 564 ei_end_p (edge_iterator i)
 565 {
 566   return (i.index == EDGE_COUNT (ei_container (i)));
 567 }
 568
 569 /* Is the iterator `i' at one position before the end of the
 570    sequence?  */
 571 static inline bool
 572 ei_one_before_end_p (edge_iterator i)
 573 {
 574   return (i.index + 1 == EDGE_COUNT (ei_container (i)));
 575 }
 576
 577 /* Advance the iterator to the next element.  */
 578 static inline void
 579 ei_next (edge_iterator *i)
 580 {
 581   gcc_assert (i->index < EDGE_COUNT (ei_container (*i)));
 582   i->index++;
 583 }
 584
 585 /* Move the iterator to the previous element.  */
 586 static inline void
 587 ei_prev (edge_iterator *i)
 588 {
 589   gcc_assert (i->index > 0);
 590   i->index--;
 591 }
 592
 593 /* Return the edge pointed to by the iterator `i'.  */
 594 static inline edge
 595 ei_edge (edge_iterator i)
 596 {
 597   return EDGE_I (ei_container (i), i.index);
 598 }
 599
 600 /* Return an edge pointed to by the iterator.  Do it safely so that
 601    NULL is returned when the iterator is pointing at the end of the
 602    sequence.  */
 603 static inline edge
 604 ei_safe_edge (edge_iterator i)
 605 {
 606   return !ei_end_p (i) ? ei_edge (i) : NULL;
 607 }
 608
 609 /* This macro serves as a convenient way to iterate each edge in a
 610    vector of predecessor or successor edges.  It must not be used when
 611    an element might be removed during the traversal, otherwise
 612    elements will be missed.  Instead, use a for-loop like that shown
 613    in the following pseudo-code:
 614
 615    FOR (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); )
 616      {
 617         IF (e != taken_edge)
 618           remove_edge (e);
 619         ELSE
 620           ei_next (&ei);
 621      }
 622 */
 623
 624 #define FOR_EACH_EDGE(EDGE,ITER,EDGE_VEC) \
 625   for ((EDGE) = NULL, (ITER) = ei_start ((EDGE_VEC)); \
 626        ((EDGE) = ei_safe_edge ((ITER))); \
 627        ei_next (&(ITER)))
 628
 629 struct edge_list * create_edge_list (void);
 630 void free_edge_list (struct edge_list *);
 631 void print_edge_list (FILE *, struct edge_list *);
 632 void verify_edge_list (FILE *, struct edge_list *);
 633 int find_edge_index (struct edge_list *, basic_block, basic_block);
 634 edge find_edge (basic_block, basic_block);
 635
 636
 637 enum update_life_extent
 638 {
 639   UPDATE_LIFE_LOCAL = 0,
 640   UPDATE_LIFE_GLOBAL = 1,
 641   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 642 };
 643
 644 /* Flags for life_analysis and update_life_info.  */
 645
 646 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 647 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 648 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 649 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 650 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 651 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 652                                            by dead code removal.  */
 653 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 654 #define PROP_EQUAL_NOTES        128     /* Take into account REG_EQUAL notes.  */
 655 #define PROP_SCAN_DEAD_STORES   256     /* Scan for dead code.  */
 656 #define PROP_ASM_SCAN           512     /* Internal flag used within flow.c
 657                                            to flag analysis of asms.  */
 658 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 659                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 660                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 661                                  | PROP_ALLOW_CFG_CHANGES \
 662                                  | PROP_SCAN_DEAD_STORES)
 663 #define PROP_POSTRELOAD         (PROP_DEATH_NOTES  \
 664                                  | PROP_KILL_DEAD_CODE  \
 665                                  | PROP_SCAN_DEAD_CODE \
 666                                  | PROP_SCAN_DEAD_STORES)
 667
 668 #define CLEANUP_EXPENSIVE       1       /* Do relatively expensive optimizations
 669                                            except for edge forwarding */
 670 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 671 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 672                                            to care REG_DEAD notes.  */
 673 #define CLEANUP_PRE_LOOP        8       /* Take care to preserve syntactic loop
 674                                            notes.  */
 675 #define CLEANUP_UPDATE_LIFE     16      /* Keep life information up to date.  */
 676 #define CLEANUP_THREADING       32      /* Do jump threading.  */
 677 #define CLEANUP_NO_INSN_DEL     64      /* Do not try to delete trivially dead
 678                                            insns.  */
 679 #define CLEANUP_CFGLAYOUT       128     /* Do cleanup in cfglayout mode.  */
 680 #define CLEANUP_LOG_LINKS       256     /* Update log links.  */
 681
 682 extern void life_analysis (FILE *, int);
 683 extern int update_life_info (sbitmap, enum update_life_extent, int);
 684 extern int update_life_info_in_dirty_blocks (enum update_life_extent, int);
 685 extern int count_or_remove_death_notes (sbitmap, int);
 686 extern int propagate_block (basic_block, regset, regset, regset, int);
 687
 688 struct propagate_block_info;
 689 extern rtx propagate_one_insn (struct propagate_block_info *, rtx);
 690 extern struct propagate_block_info *init_propagate_block_info
 691  (basic_block, regset, regset, regset, int);
 692 extern void free_propagate_block_info (struct propagate_block_info *);
 693
 694 /* In lcm.c */
 695 extern struct edge_list *pre_edge_lcm (FILE *, int, sbitmap *, sbitmap *,
 696                                        sbitmap *, sbitmap *, sbitmap **,
 697                                        sbitmap **);
 698 extern struct edge_list *pre_edge_rev_lcm (FILE *, int, sbitmap *,
 699                                            sbitmap *, sbitmap *,
 700                                            sbitmap *, sbitmap **,
 701                                            sbitmap **);
 702 extern void compute_available (sbitmap *, sbitmap *, sbitmap *, sbitmap *);
 703 extern int optimize_mode_switching (FILE *);
 704
 705 /* In predict.c */
 706 extern void estimate_probability (struct loops *);
 707 extern void expected_value_to_br_prob (void);
 708 extern bool maybe_hot_bb_p (basic_block);
 709 extern bool probably_cold_bb_p (basic_block);
 710 extern bool probably_never_executed_bb_p (basic_block);
 711 extern bool tree_predicted_by_p (basic_block, enum br_predictor);
 712 extern bool rtl_predicted_by_p (basic_block, enum br_predictor);
 713 extern void tree_predict_edge (edge, enum br_predictor, int);
 714 extern void rtl_predict_edge (edge, enum br_predictor, int);
 715 extern void predict_edge_def (edge, enum br_predictor, enum prediction);
 716 extern void guess_outgoing_edge_probabilities (basic_block);
 717
 718 /* In flow.c */
 719 extern void init_flow (void);
 720 extern void debug_bb (basic_block);
 721 extern basic_block debug_bb_n (int);
 722 extern void dump_regset (regset, FILE *);
 723 extern void debug_regset (regset);
 724 extern void allocate_reg_life_data (void);
 725 extern void expunge_block (basic_block);
 726 extern void link_block (basic_block, basic_block);
 727 extern void unlink_block (basic_block);
 728 extern void compact_blocks (void);
 729 extern basic_block alloc_block (void);
 730 extern void find_unreachable_blocks (void);
 731 extern int delete_noop_moves (void);
 732 extern basic_block force_nonfallthru (edge);
 733 extern rtx block_label (basic_block);
 734 extern bool forwarder_block_p (basic_block);
 735 extern bool purge_all_dead_edges (int);
 736 extern bool purge_dead_edges (basic_block);
 737 extern void find_sub_basic_blocks (basic_block);
 738 extern void find_many_sub_basic_blocks (sbitmap);
 739 extern void rtl_make_eh_edge (sbitmap *, basic_block, rtx);
 740 extern bool can_fallthru (basic_block, basic_block);
 741 extern bool could_fall_through (basic_block, basic_block);
 742 extern void flow_nodes_print (const char *, const sbitmap, FILE *);
 743 extern void flow_edge_list_print (const char *, const edge *, int, FILE *);
 744 extern void alloc_aux_for_block (basic_block, int);
 745 extern void alloc_aux_for_blocks (int);
 746 extern void clear_aux_for_blocks (void);
 747 extern void free_aux_for_blocks (void);
 748 extern void alloc_aux_for_edge (edge, int);
 749 extern void alloc_aux_for_edges (int);
 750 extern void clear_aux_for_edges (void);
 751 extern void free_aux_for_edges (void);
 752 extern void find_basic_blocks (rtx, int, FILE *);
 753 extern bool cleanup_cfg (int);
 754 extern bool delete_unreachable_blocks (void);
 755 extern bool merge_seq_blocks (void);
 756
 757 typedef struct conflict_graph_def *conflict_graph;
 758
 759 /* Callback function when enumerating conflicts.  The arguments are
 760    the smaller and larger regno in the conflict.  Returns zero if
 761    enumeration is to continue, nonzero to halt enumeration.  */
 762 typedef int (*conflict_graph_enum_fn) (int, int, void *);
 763
 764
 765 /* Prototypes of operations on conflict graphs.  */
 766
 767 extern conflict_graph conflict_graph_new
 768  (int);
 769 extern void conflict_graph_delete (conflict_graph);
 770 extern int conflict_graph_add (conflict_graph, int, int);
 771 extern int conflict_graph_conflict_p (conflict_graph, int, int);
 772 extern void conflict_graph_enum (conflict_graph, int, conflict_graph_enum_fn,
 773                                  void *);
 774 extern void conflict_graph_merge_regs (conflict_graph, int, int);
 775 extern void conflict_graph_print (conflict_graph, FILE*);
 776 extern bool mark_dfs_back_edges (void);
 777 extern void set_edge_can_fallthru_flag (void);
 778 extern void update_br_prob_note (basic_block);
 779 extern void fixup_abnormal_edges (void);
 780 extern bool inside_basic_block_p (rtx);
 781 extern bool control_flow_insn_p (rtx);
 782
 783 /* In bb-reorder.c */
 784 extern void reorder_basic_blocks (unsigned int);
 785 extern void partition_hot_cold_basic_blocks (void);
 786
 787 /* In cfg.c */
 788 extern void alloc_rbi_pool (void);
 789 extern void initialize_bb_rbi (basic_block bb);
 790 extern void free_rbi_pool (void);
 791
 792 /* In dominance.c */
 793
 794 enum cdi_direction
 795 {
 796   CDI_DOMINATORS,
 797   CDI_POST_DOMINATORS
 798 };
 799
 800 enum dom_state
 801 {
 802   DOM_NONE,             /* Not computed at all.  */
 803   DOM_NO_FAST_QUERY,    /* The data is OK, but the fast query data are not usable.  */
 804   DOM_OK                /* Everything is ok.  */
 805 };
 806
 807 extern enum dom_state dom_computed[2];
 808
 809 extern bool dom_info_available_p (enum cdi_direction);
 810 extern void calculate_dominance_info (enum cdi_direction);
 811 extern void free_dominance_info (enum cdi_direction);
 812 extern basic_block nearest_common_dominator (enum cdi_direction,
 813                                              basic_block, basic_block);
 814 extern void set_immediate_dominator (enum cdi_direction, basic_block,
 815                                      basic_block);
 816 extern basic_block get_immediate_dominator (enum cdi_direction, basic_block);
 817 extern bool dominated_by_p (enum cdi_direction, basic_block, basic_block);
 818 extern int get_dominated_by (enum cdi_direction, basic_block, basic_block **);
 819 extern unsigned get_dominated_by_region (enum cdi_direction, basic_block *,
 820                                          unsigned, basic_block *);
 821 extern void add_to_dominance_info (enum cdi_direction, basic_block);
 822 extern void delete_from_dominance_info (enum cdi_direction, basic_block);
 823 basic_block recount_dominator (enum cdi_direction, basic_block);
 824 extern void redirect_immediate_dominators (enum cdi_direction, basic_block,
 825                                            basic_block);
 826 extern void iterate_fix_dominators (enum cdi_direction, basic_block *, int);
 827 extern void verify_dominators (enum cdi_direction);
 828 extern basic_block first_dom_son (enum cdi_direction, basic_block);
 829 extern basic_block next_dom_son (enum cdi_direction, basic_block);
 830 extern edge try_redirect_by_replacing_jump (edge, basic_block, bool);
 831 extern void break_superblocks (void);
 832 extern void check_bb_profile (basic_block, FILE *);
 833 extern void update_bb_profile_for_threading (basic_block, int, gcov_type, edge);
 834
 835 #include "cfghooks.h"
 836
 837 #endif /* GCC_BASIC_BLOCK_H */