gcc/basic-block.h

   1 /* Define control and data flow tables, and regsets.
   2    Copyright (C) 1987, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 #ifndef _BASIC_BLOCK_H
  22 #define _BASIC_BLOCK_H 1
  23
  24 #include "bitmap.h"
  25 #include "sbitmap.h"
  26 #include "varray.h"
  27 #include "partition.h"
  28
  29 /* Head of register set linked list.  */
  30 typedef bitmap_head regset_head;
  31 /* A pointer to a regset_head.  */
  32 typedef bitmap regset;
  33
  34 /* Initialize a new regset.  */
  35 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD)
  36
  37 /* Clear a register set by freeing up the linked list.  */
  38 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  39
  40 /* Copy a register set to another register set.  */
  41 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  42
  43 /* Compare two register sets.  */
  44 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  45
  46 /* `and' a register set with a second register set.  */
  47 #define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)
  48
  49 /* `and' the complement of a register set with a register set.  */
  50 #define AND_COMPL_REG_SET(TO, FROM) \
  51   bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
  52
  53 /* Inclusive or a register set with a second register set.  */
  54 #define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
  55
  56 /* Exclusive or a register set with a second register set.  */
  57 #define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
  58
  59 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  60 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  61   bitmap_ior_and_compl (TO, FROM1, FROM2)
  62
  63 /* Clear a single register in a register set.  */
  64 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  65
  66 /* Set a single register in a register set.  */
  67 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  68
  69 /* Return true if a register is set in a register set.  */
  70 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  71
  72 /* Copy the hard registers in a register set to the hard register set.  */
  73 extern void reg_set_to_hard_reg_set PARAMS ((HARD_REG_SET *, bitmap));
  74 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  75 do {                                                                    \
  76   CLEAR_HARD_REG_SET (TO);                                              \
  77   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  78 } while (0)
  79
  80 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  81    register number and executing CODE for all registers that are set. */
  82 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE)            \
  83   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)
  84
  85 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  86    REGNUM to the register number and executing CODE for all registers that are
  87    set in the first regset and not set in the second. */
  88 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  89   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  90
  91 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  92    REGNUM to the register number and executing CODE for all registers that are
  93    set in both regsets. */
  94 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  95   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  96
  97 /* Allocate a register set with oballoc.  */
  98 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
  99
 100 /* Initialize a register set.  Returns the new register set.  */
 101 #define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD)
 102
 103 /* Do any cleanup needed on a regset when it is no longer used.  */
 104 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
 105
 106 /* Do any one-time initializations needed for regsets.  */
 107 #define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
 108
 109 /* Grow any tables needed when the number of registers is calculated
 110    or extended.  For the linked list allocation, nothing needs to
 111    be done, other than zero the statistics on the first allocation.  */
 112 #define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
 113
 114 /* Control flow edge information.  */
 115 typedef struct edge_def {
 116   /* Links through the predecessor and successor lists.  */
 117   struct edge_def *pred_next, *succ_next;
 118
 119   /* The two blocks at the ends of the edge.  */
 120   struct basic_block_def *src, *dest;
 121
 122   /* Instructions queued on the edge.  */
 123   rtx insns;
 124
 125   /* Auxiliary info specific to a pass.  */
 126   void *aux;
 127
 128   int flags;                    /* see EDGE_* below  */
 129   int probability;              /* biased by REG_BR_PROB_BASE */
 130   int count;                    /* Expected number of executions calculated
 131                                    in profile.c  */
 132 } *edge;
 133
 134 #define EDGE_FALLTHRU           1
 135 #define EDGE_CRITICAL           2
 136 #define EDGE_ABNORMAL           4
 137 #define EDGE_ABNORMAL_CALL      8
 138 #define EDGE_EH                 16
 139 #define EDGE_FAKE               32
 140
 141 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 142
 143
 144 /* Basic blocks need not start with a label nor end with a jump insn.
 145    For example, a previous basic block may just "conditionally fall"
 146    into the succeeding basic block, and the last basic block need not
 147    end with a jump insn.  Block 0 is a descendant of the entry block.
 148
 149    A basic block beginning with two labels cannot have notes between
 150    the labels.
 151
 152    Data for jump tables are stored in jump_insns that occur in no
 153    basic block even though these insns can follow or precede insns in
 154    basic blocks.  */
 155
 156 /* Basic block information indexed by block number.  */
 157 typedef struct basic_block_def {
 158   /* The first and last insns of the block.  */
 159   rtx head, end;
 160
 161   /* The edges into and out of the block.  */
 162   edge pred, succ;
 163
 164   /* Liveness info.  Note that in SSA form, global_live_at_start does
 165      not reflect the use of regs in phi functions, since the liveness
 166      of these regs may depend on which edge was taken into the block.  */
 167   regset local_set;
 168   regset cond_local_set;
 169   regset global_live_at_start;
 170   regset global_live_at_end;
 171
 172   /* Auxiliary info specific to a pass.  */
 173   void *aux;
 174
 175   /* The index of this block.  */
 176   int index;
 177   /* The loop depth of this block plus one.  */
 178   int loop_depth;
 179
 180   /* The active eh region before head and after end.  */
 181   int eh_beg, eh_end;
 182
 183   int count;            /* Expected number of executions: calculated in
 184                            profile.c */
 185 } *basic_block;
 186
 187 /* Number of basic blocks in the current function.  */
 188
 189 extern int n_basic_blocks;
 190
 191 /* Number of edges in the current function.  */
 192
 193 extern int n_edges;
 194
 195 /* Index by basic block number, get basic block struct info.  */
 196
 197 extern varray_type basic_block_info;
 198
 199 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 200
 201 /* What registers are live at the setjmp call.  */
 202
 203 extern regset regs_live_at_setjmp;
 204
 205 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 206    If the value is REG_BLOCK_GLOBAL (-2),
 207    it means (REG n) is used in more than one basic block.
 208    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 209    This information remains valid for the rest of the compilation
 210    of the current function; it is used to control register allocation.  */
 211
 212 #define REG_BLOCK_UNKNOWN -1
 213 #define REG_BLOCK_GLOBAL -2
 214
 215 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 216 \f
 217 /* Stuff for recording basic block info.  */
 218
 219 #define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
 220 #define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
 221
 222 /* Special block numbers [markers] for entry and exit.  */
 223 #define ENTRY_BLOCK (-1)
 224 #define EXIT_BLOCK (-2)
 225
 226 /* Special block number not valid for any block. */
 227 #define INVALID_BLOCK (-3)
 228
 229 /* Similarly, block pointers for the edge list.  */
 230 extern struct basic_block_def entry_exit_blocks[2];
 231 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
 232 #define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])
 233
 234 extern varray_type basic_block_for_insn;
 235 #define BLOCK_FOR_INSN(INSN)  VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
 236 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 237
 238 extern void compute_bb_for_insn         PARAMS ((int));
 239 extern void update_bb_for_insn          PARAMS ((basic_block));
 240 extern void set_block_for_insn          PARAMS ((rtx, basic_block));
 241 extern void set_block_num               PARAMS ((rtx, int));
 242
 243 extern void free_basic_block_vars       PARAMS ((int));
 244
 245 extern edge split_block                 PARAMS ((basic_block, rtx));
 246 extern basic_block split_edge           PARAMS ((edge));
 247 extern void insert_insn_on_edge         PARAMS ((rtx, edge));
 248 extern void commit_edge_insertions      PARAMS ((void));
 249 extern void remove_fake_edges           PARAMS ((void));
 250 extern void add_noreturn_fake_exit_edges        PARAMS ((void));
 251 extern void connect_infinite_loops_to_exit      PARAMS ((void));
 252 extern rtx flow_delete_insn             PARAMS ((rtx));
 253 extern void flow_delete_insn_chain      PARAMS ((rtx, rtx));
 254 extern void make_edge                   PARAMS ((sbitmap *, basic_block,
 255                                                  basic_block, int));
 256 extern void remove_edge                 PARAMS ((edge));
 257 extern void redirect_edge_succ          PARAMS ((edge, basic_block));
 258 extern void redirect_edge_pred          PARAMS ((edge, basic_block));
 259 extern void create_basic_block          PARAMS ((int, rtx, rtx, rtx));
 260 extern int flow_delete_block            PARAMS ((basic_block));
 261 extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
 262 extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
 263                                                  basic_block));
 264
 265 /* Structure to hold information for each natural loop.  */
 266 struct loop
 267 {
 268   /* Index into loops array.  */
 269   int num;
 270
 271   /* Basic block of loop header.  */
 272   basic_block header;
 273
 274   /* Basic block of loop latch.  */
 275   basic_block latch;
 276
 277   /* Basic block of loop pre-header or NULL if it does not exist.  */
 278   basic_block pre_header;
 279
 280   /* Array of edges along the pre-header extended basic block trace.
 281      The source of the first edge is the root node of pre-header
 282      extended basic block, if it exists.  */
 283   edge *pre_header_edges;
 284
 285   /* Number of edges along the pre_header extended basic block trace.  */
 286   int num_pre_header_edges;
 287
 288   /* The first block in the loop.  This is not necessarily the same as
 289      the loop header.  */
 290   basic_block first;
 291
 292   /* The last block in the loop.  This is not necessarily the same as
 293      the loop latch.  */
 294   basic_block last;
 295
 296   /* Bitmap of blocks contained within the loop.  */
 297   sbitmap nodes;
 298
 299   /* Number of blocks contained within the loop.  */
 300   int num_nodes;
 301
 302   /* Array of edges that enter the loop.  */
 303   edge *entry_edges;
 304
 305   /* Number of edges that enter the loop.  */
 306   int num_entries;
 307
 308   /* Array of edges that exit the loop.  */
 309   edge *exit_edges;
 310
 311   /* Number of edges that exit the loop.  */
 312   int num_exits;
 313
 314   /* Bitmap of blocks that dominate all exits of the loop.  */
 315   sbitmap exits_doms;
 316
 317   /* The loop nesting depth.  */
 318   int depth;
 319
 320   /* The height of the loop (enclosed loop levels) within the loop
 321      hierarchy tree.  */
 322   int level;
 323
 324   /* The outer (parent) loop or NULL if outermost loop.  */
 325   struct loop *outer;
 326
 327   /* The first inner (child) loop or NULL if innermost loop.  */
 328   struct loop *inner;
 329
 330   /* Link to the next (sibling) loop.  */
 331   struct loop *next;
 332
 333   /* Non-zero if the loop shares a header with another loop.  */
 334   int shared;
 335
 336   /* Non-zero if the loop is invalid (e.g., contains setjmp.).  */
 337   int invalid;
 338
 339   /* Auxiliary info specific to a pass.  */
 340   void *aux;
 341
 342   /* The following are currently used by loop.c but they are likely to
 343      disappear as loop.c is converted to use the CFG.  */
 344
 345   /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP.  */
 346   rtx vtop;
 347
 348   /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
 349      A continue statement will generate a branch to NEXT_INSN (cont).  */
 350   rtx cont;
 351
 352   /* The dominator of cont.  */
 353   rtx cont_dominator;
 354
 355   /* The NOTE_INSN_LOOP_BEG.  */
 356   rtx start;
 357
 358   /* The NOTE_INSN_LOOP_END.  */
 359   rtx end;
 360
 361   /* For a rotated loop that is entered near the bottom,
 362      this is the label at the top.  Otherwise it is zero.  */
 363   rtx top;
 364
 365   /* Place in the loop where control enters.  */
 366   rtx scan_start;
 367
 368   /* List of all LABEL_REFs which refer to code labels outside the
 369      loop.  Used by routines that need to know all loop exits, such as
 370      final_biv_value and final_giv_value.
 371
 372      This does not include loop exits due to return instructions.
 373      This is because all bivs and givs are pseudos, and hence must be
 374      dead after a return, so the presense of a return does not affect
 375      any of the optimizations that use this info.  It is simpler to
 376      just not include return instructions on this list.  */
 377   rtx exit_labels;
 378
 379   /* The number of LABEL_REFs on exit_labels for this loop and all
 380      loops nested inside it.  */
 381   int exit_count;
 382 };
 383
 384
 385 /* Structure to hold CFG information about natural loops within a function.  */
 386 struct loops
 387 {
 388   /* Number of natural loops in the function.  */
 389   int num;
 390
 391   /* Maxium nested loop level in the function.  */
 392   int levels;
 393
 394   /* Array of natural loop descriptors (scanning this array in reverse order
 395      will find the inner loops before their enclosing outer loops).  */
 396   struct loop *array;
 397
 398   /* Pointer to root of loop heirachy tree.  */
 399   struct loop *tree;
 400
 401   /* Information derived from the CFG.  */
 402   struct cfg
 403   {
 404     /* The bitmap vector of dominators or NULL if not computed.  */
 405     sbitmap *dom;
 406
 407     /* The ordering of the basic blocks in a depth first search.  */
 408     int *dfs_order;
 409
 410     /* The reverse completion ordering of the basic blocks found in a
 411        depth first search.  */
 412     int *rc_order;
 413   } cfg;
 414
 415   /* Headers shared by multiple loops that should be merged.  */
 416   sbitmap shared_headers;
 417 };
 418
 419 extern int flow_loops_find PARAMS ((struct loops *, int flags));
 420 extern int flow_loops_update PARAMS ((struct loops *, int flags));
 421 extern void flow_loops_free PARAMS ((struct loops *));
 422 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
 423                                      void (*)(const struct loop *,
 424                                               FILE *, int), int));
 425 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
 426                                     void (*)(const struct loop *,
 427                                              FILE *, int), int));
 428
 429 /* This structure maintains an edge list vector.  */
 430 struct edge_list
 431 {
 432   int num_blocks;
 433   int num_edges;
 434   edge *index_to_edge;
 435 };
 436
 437 /* This is the value which indicates no edge is present.  */
 438 #define EDGE_INDEX_NO_EDGE      -1
 439
 440 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 441    if there is no edge between the 2 basic blocks.  */
 442 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 443
 444 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 445    block which is either the pred or succ end of the indexed edge.  */
 446 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 447 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 448
 449 /* INDEX_EDGE returns a pointer to the edge.  */
 450 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 451
 452 /* Number of edges in the compressed edge list.  */
 453 #define NUM_EDGES(el)                   ((el)->num_edges)
 454
 455 struct edge_list * create_edge_list     PARAMS ((void));
 456 void free_edge_list                     PARAMS ((struct edge_list *));
 457 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 458 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 459 int find_edge_index                     PARAMS ((struct edge_list *,
 460                                                  basic_block, basic_block));
 461
 462
 463 enum update_life_extent
 464 {
 465   UPDATE_LIFE_LOCAL = 0,
 466   UPDATE_LIFE_GLOBAL = 1,
 467   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 468 };
 469
 470 /* Flags for life_analysis and update_life_info.  */
 471
 472 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 473 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 474 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 475 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 476 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 477 #define PROP_AUTOINC            32      /* Create autoinc mem references.  */
 478 #define PROP_FINAL              63      /* All of the above.  */
 479 /* Flag number 64 is used internally in flow.c.  */
 480
 481 /* Flags for loop discovery.  */
 482
 483 #define LOOP_TREE               1       /* Build loop hierarchy tree.  */
 484 #define LOOP_PRE_HEADER         2       /* Analyse loop pre-header.  */
 485 #define LOOP_EDGES              4       /* Find entry and exit edges.  */
 486 #define LOOP_EXITS_DOMS         8       /* Find nodes that dom. all exits.  */
 487 #define LOOP_ALL               15       /* All of the above  */
 488
 489 extern void life_analysis       PARAMS ((rtx, FILE *, int));
 490 extern void update_life_info    PARAMS ((sbitmap, enum update_life_extent,
 491                                          int));
 492 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 493 extern void propagate_block     PARAMS ((basic_block, regset, regset, regset,
 494                                          int));
 495
 496 struct propagate_block_info;
 497 extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
 498 extern struct propagate_block_info *init_propagate_block_info
 499   PARAMS ((basic_block, regset, regset, regset, int));
 500 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
 501
 502 /* In lcm.c */
 503 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 504                                                  sbitmap *, sbitmap *,
 505                                                  sbitmap *, sbitmap **,
 506                                                  sbitmap **));
 507 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 508                                                    sbitmap *, sbitmap *,
 509                                                    sbitmap *, sbitmap **,
 510                                                    sbitmap **));
 511 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 512                                                  sbitmap *, sbitmap *));
 513 extern int optimize_mode_switching      PARAMS ((FILE *));
 514
 515 /* In emit-rtl.c.  */
 516 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 517 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 518
 519 /* In predict.c */
 520 extern void estimate_probability        PARAMS ((struct loops *));
 521 extern void expected_value_to_br_prob   PARAMS ((void));
 522
 523 /* In flow.c */
 524 extern void init_flow                   PARAMS ((void));
 525 extern void reorder_basic_blocks        PARAMS ((void));
 526 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 527 extern void debug_bb                    PARAMS ((basic_block));
 528 extern void debug_bb_n                  PARAMS ((int));
 529 extern void dump_regset                 PARAMS ((regset, FILE *));
 530 extern void debug_regset                PARAMS ((regset));
 531 extern void allocate_reg_life_data      PARAMS ((void));
 532
 533 /* This function is always defined so it can be called from the
 534    debugger, and it is declared extern so we don't get warnings about
 535    it being unused. */
 536 extern void verify_flow_info            PARAMS ((void));
 537 extern int flow_loop_outside_edge_p     PARAMS ((const struct loop *, edge));
 538
 539 typedef struct conflict_graph_def *conflict_graph;
 540
 541 /* Callback function when enumerating conflicts.  The arguments are
 542    the smaller and larger regno in the conflict.  Returns zero if
 543    enumeration is to continue, non-zero to halt enumeration.  */
 544 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
 545
 546
 547 /* Prototypes of operations on conflict graphs.  */
 548
 549 extern conflict_graph conflict_graph_new
 550                                         PARAMS ((int));
 551 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 552 extern int conflict_graph_add           PARAMS ((conflict_graph,
 553                                                  int, int));
 554 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 555                                                  int, int));
 556 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 557                                                  conflict_graph_enum_fn,
 558                                                  void *));
 559 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 560                                                  int));
 561 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 562 extern conflict_graph conflict_graph_compute
 563                                         PARAMS ((regset,
 564                                                  partition));
 565
 566 /* In dominance.c */
 567
 568 enum cdi_direction
 569 {
 570   CDI_DOMINATORS,
 571   CDI_POST_DOMINATORS
 572 };
 573
 574 extern void calculate_dominance_info    PARAMS ((int *, sbitmap *,
 575                                                  enum cdi_direction));
 576
 577 #endif /* _BASIC_BLOCK_H */