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 global_live_at_start;
 169   regset global_live_at_end;
 170
 171   /* Auxiliary info specific to a pass.  */
 172   void *aux;
 173
 174   /* The index of this block.  */
 175   int index;
 176   /* The loop depth of this block plus one.  */
 177   int loop_depth;
 178
 179   /* The active eh region before head and after end.  */
 180   int eh_beg, eh_end;
 181
 182   int count;            /* Expected number of executions: calculated in
 183                            profile.c */
 184 } *basic_block;
 185
 186 /* Number of basic blocks in the current function.  */
 187
 188 extern int n_basic_blocks;
 189
 190 /* Number of edges in the current function.  */
 191
 192 extern int n_edges;
 193
 194 /* Index by basic block number, get basic block struct info.  */
 195
 196 extern varray_type basic_block_info;
 197
 198 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 199
 200 /* What registers are live at the setjmp call.  */
 201
 202 extern regset regs_live_at_setjmp;
 203
 204 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 205    If the value is REG_BLOCK_GLOBAL (-2),
 206    it means (REG n) is used in more than one basic block.
 207    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 208    This information remains valid for the rest of the compilation
 209    of the current function; it is used to control register allocation.  */
 210
 211 #define REG_BLOCK_UNKNOWN -1
 212 #define REG_BLOCK_GLOBAL -2
 213
 214 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 215 \f
 216 /* Stuff for recording basic block info.  */
 217
 218 #define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
 219 #define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
 220
 221 /* Special block numbers [markers] for entry and exit.  */
 222 #define ENTRY_BLOCK (-1)
 223 #define EXIT_BLOCK (-2)
 224
 225 /* Special block number not valid for any block. */
 226 #define INVALID_BLOCK (-3)
 227
 228 /* Similarly, block pointers for the edge list.  */
 229 extern struct basic_block_def entry_exit_blocks[2];
 230 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
 231 #define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])
 232
 233 extern varray_type basic_block_for_insn;
 234 #define BLOCK_FOR_INSN(INSN)  VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
 235 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 236
 237 extern void compute_bb_for_insn         PARAMS ((int));
 238 extern void update_bb_for_insn          PARAMS ((basic_block));
 239 extern void set_block_for_insn          PARAMS ((rtx, basic_block));
 240 extern void set_block_num               PARAMS ((rtx, int));
 241
 242 extern void free_basic_block_vars       PARAMS ((int));
 243
 244 extern edge split_block                 PARAMS ((basic_block, rtx));
 245 extern basic_block split_edge           PARAMS ((edge));
 246 extern void insert_insn_on_edge         PARAMS ((rtx, edge));
 247 extern void commit_edge_insertions      PARAMS ((void));
 248 extern void remove_fake_edges           PARAMS ((void));
 249 extern void add_noreturn_fake_exit_edges        PARAMS ((void));
 250 extern void connect_infinite_loops_to_exit      PARAMS ((void));
 251 extern rtx flow_delete_insn             PARAMS ((rtx));
 252 extern void flow_delete_insn_chain      PARAMS ((rtx, rtx));
 253 extern void make_edge                   PARAMS ((sbitmap *, basic_block,
 254                                                  basic_block, int));
 255 extern void remove_edge                 PARAMS ((edge));
 256 extern void redirect_edge_succ          PARAMS ((edge, basic_block));
 257 extern void redirect_edge_pred          PARAMS ((edge, basic_block));
 258 extern void create_basic_block          PARAMS ((int, rtx, rtx, rtx));
 259 extern int flow_delete_block            PARAMS ((basic_block));
 260 extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
 261 extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
 262                                                  basic_block));
 263
 264 /* Structure to hold information for each natural loop.  */
 265 struct loop
 266 {
 267   /* Index into loops array.  */
 268   int num;
 269
 270   /* Basic block of loop header.  */
 271   basic_block header;
 272
 273   /* Basic block of loop latch.  */
 274   basic_block latch;
 275
 276   /* Basic block of loop pre-header or NULL if it does not exist.  */
 277   basic_block pre_header;
 278
 279   /* Array of edges along the pre-header extended basic block trace.
 280      The source of the first edge is the root node of pre-header
 281      extended basic block, if it exists.  */
 282   edge *pre_header_edges;
 283
 284   /* Number of edges along the pre_header extended basic block trace.  */
 285   int num_pre_header_edges;
 286
 287   /* The first block in the loop.  This is not necessarily the same as
 288      the loop header.  */
 289   basic_block first;
 290
 291   /* The last block in the loop.  This is not necessarily the same as
 292      the loop latch.  */
 293   basic_block last;
 294
 295   /* Bitmap of blocks contained within the loop.  */
 296   sbitmap nodes;
 297
 298   /* Number of blocks contained within the loop.  */
 299   int num_nodes;
 300
 301   /* Array of edges that enter the loop.  */
 302   edge *entry_edges;
 303
 304   /* Number of edges that enter the loop.  */
 305   int num_entries;
 306
 307   /* Array of edges that exit the loop.  */
 308   edge *exit_edges;
 309
 310   /* Number of edges that exit the loop.  */
 311   int num_exits;
 312
 313   /* Bitmap of blocks that dominate all exits of the loop.  */
 314   sbitmap exits_doms;
 315
 316   /* The loop nesting depth.  */
 317   int depth;
 318
 319   /* The height of the loop (enclosed loop levels) within the loop
 320      hierarchy tree.  */
 321   int level;
 322
 323   /* The outer (parent) loop or NULL if outermost loop.  */
 324   struct loop *outer;
 325
 326   /* The first inner (child) loop or NULL if innermost loop.  */
 327   struct loop *inner;
 328
 329   /* Link to the next (sibling) loop.  */
 330   struct loop *next;
 331
 332   /* Non-zero if the loop shares a header with another loop.  */
 333   int shared;
 334
 335   /* Non-zero if the loop is invalid (e.g., contains setjmp.).  */
 336   int invalid;
 337
 338   /* Auxiliary info specific to a pass.  */
 339   void *aux;
 340
 341   /* The following are currently used by loop.c but they are likely to
 342      disappear as loop.c is converted to use the CFG.  */
 343
 344   /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP.  */
 345   rtx vtop;
 346
 347   /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
 348      A continue statement will generate a branch to NEXT_INSN (cont).  */
 349   rtx cont;
 350
 351   /* The dominator of cont.  */
 352   rtx cont_dominator;
 353
 354   /* The NOTE_INSN_LOOP_BEG.  */
 355   rtx start;
 356
 357   /* The NOTE_INSN_LOOP_END.  */
 358   rtx end;
 359
 360   /* For a rotated loop that is entered near the bottom,
 361      this is the label at the top.  Otherwise it is zero.  */
 362   rtx top;
 363
 364   /* Place in the loop where control enters.  */
 365   rtx scan_start;
 366
 367   /* List of all LABEL_REFs which refer to code labels outside the
 368      loop.  Used by routines that need to know all loop exits, such as
 369      final_biv_value and final_giv_value.
 370
 371      This does not include loop exits due to return instructions.
 372      This is because all bivs and givs are pseudos, and hence must be
 373      dead after a return, so the presense of a return does not affect
 374      any of the optimizations that use this info.  It is simpler to
 375      just not include return instructions on this list.  */
 376   rtx exit_labels;
 377
 378   /* The number of LABEL_REFs on exit_labels for this loop and all
 379      loops nested inside it.  */
 380   int exit_count;
 381 };
 382
 383
 384 /* Structure to hold CFG information about natural loops within a function.  */
 385 struct loops
 386 {
 387   /* Number of natural loops in the function.  */
 388   int num;
 389
 390   /* Maxium nested loop level in the function.  */
 391   int levels;
 392
 393   /* Array of natural loop descriptors (scanning this array in reverse order
 394      will find the inner loops before their enclosing outer loops).  */
 395   struct loop *array;
 396
 397   /* Pointer to root of loop heirachy tree.  */
 398   struct loop *tree;
 399
 400   /* Information derived from the CFG.  */
 401   struct cfg
 402   {
 403     /* The bitmap vector of dominators or NULL if not computed.  */
 404     sbitmap *dom;
 405
 406     /* The ordering of the basic blocks in a depth first search.  */
 407     int *dfs_order;
 408
 409     /* The reverse completion ordering of the basic blocks found in a
 410        depth first search.  */
 411     int *rc_order;
 412   } cfg;
 413
 414   /* Headers shared by multiple loops that should be merged.  */
 415   sbitmap shared_headers;
 416 };
 417
 418 extern int flow_loops_find PARAMS ((struct loops *, int flags));
 419 extern int flow_loops_update PARAMS ((struct loops *, int flags));
 420 extern void flow_loops_free PARAMS ((struct loops *));
 421 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
 422                                      void (*)(const struct loop *,
 423                                               FILE *, int), int));
 424 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
 425                                     void (*)(const struct loop *,
 426                                              FILE *, int), int));
 427
 428 /* This structure maintains an edge list vector.  */
 429 struct edge_list
 430 {
 431   int num_blocks;
 432   int num_edges;
 433   edge *index_to_edge;
 434 };
 435
 436 /* This is the value which indicates no edge is present.  */
 437 #define EDGE_INDEX_NO_EDGE      -1
 438
 439 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 440    if there is no edge between the 2 basic blocks.  */
 441 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 442
 443 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 444    block which is either the pred or succ end of the indexed edge.  */
 445 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 446 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 447
 448 /* INDEX_EDGE returns a pointer to the edge.  */
 449 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 450
 451 /* Number of edges in the compressed edge list.  */
 452 #define NUM_EDGES(el)                   ((el)->num_edges)
 453
 454 struct edge_list * create_edge_list     PARAMS ((void));
 455 void free_edge_list                     PARAMS ((struct edge_list *));
 456 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 457 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 458 int find_edge_index                     PARAMS ((struct edge_list *,
 459                                                  basic_block, basic_block));
 460
 461 extern void compute_flow_dominators     PARAMS ((sbitmap *, sbitmap *));
 462 extern void compute_immediate_dominators        PARAMS ((int *, sbitmap *));
 463 extern void compute_immediate_postdominators    PARAMS ((int *, sbitmap *));
 464
 465
 466 enum update_life_extent
 467 {
 468   UPDATE_LIFE_LOCAL = 0,
 469   UPDATE_LIFE_GLOBAL = 1,
 470   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 471 };
 472
 473 /* Flags for life_analysis and update_life_info.  */
 474
 475 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 476 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 477 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 478 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 479 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 480 #define PROP_AUTOINC            32      /* Create autoinc mem references.  */
 481 #define PROP_FINAL              63      /* All of the above.  */
 482
 483
 484 /* Flags for loop discovery.  */
 485
 486 #define LOOP_TREE               1       /* Build loop hierarchy tree.  */
 487 #define LOOP_PRE_HEADER         2       /* Analyse loop pre-header.  */
 488 #define LOOP_EDGES              4       /* Find entry and exit edges.  */
 489 #define LOOP_EXITS_DOMS         8       /* Find nodes that dom. all exits.  */
 490 #define LOOP_ALL               15       /* All of the above  */
 491
 492 extern void life_analysis       PARAMS ((rtx, FILE *, int));
 493 extern void update_life_info    PARAMS ((sbitmap, enum update_life_extent,
 494                                          int));
 495 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 496 extern void propagate_block     PARAMS ((basic_block, regset, regset, int));
 497
 498 struct propagate_block_info;
 499 extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
 500 extern struct propagate_block_info *init_propagate_block_info
 501   PARAMS ((basic_block, regset, regset, int));
 502 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
 503
 504 /* In lcm.c */
 505 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 506                                                  sbitmap *, sbitmap *,
 507                                                  sbitmap *, sbitmap **,
 508                                                  sbitmap **));
 509 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 510                                                    sbitmap *, sbitmap *,
 511                                                    sbitmap *, sbitmap **,
 512                                                    sbitmap **));
 513 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 514                                                  sbitmap *, sbitmap *));
 515 extern int optimize_mode_switching      PARAMS ((FILE *));
 516
 517 /* In emit-rtl.c.  */
 518 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 519 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 520
 521 /* In predict.c */
 522 extern void estimate_probability        PARAMS ((struct loops *));
 523 extern void expected_value_to_br_prob   PARAMS ((void));
 524
 525 /* In flow.c */
 526 extern void init_flow                   PARAMS ((void));
 527 extern void reorder_basic_blocks        PARAMS ((void));
 528 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 529 extern void debug_bb                    PARAMS ((basic_block));
 530 extern void debug_bb_n                  PARAMS ((int));
 531 extern void dump_regset                 PARAMS ((regset, FILE *));
 532 extern void debug_regset                PARAMS ((regset));
 533 extern void allocate_reg_life_data      PARAMS ((void));
 534
 535 /* This function is always defined so it can be called from the
 536    debugger, and it is declared extern so we don't get warnings about
 537    it being unused. */
 538 extern void verify_flow_info            PARAMS ((void));
 539 extern int flow_loop_outside_edge_p     PARAMS ((const struct loop *, edge));
 540
 541 typedef struct conflict_graph_def *conflict_graph;
 542
 543 /* Callback function when enumerating conflicts.  The arguments are
 544    the smaller and larger regno in the conflict.  Returns zero if
 545    enumeration is to continue, non-zero to halt enumeration.  */
 546 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
 547
 548
 549 /* Prototypes of operations on conflict graphs.  */
 550
 551 extern conflict_graph conflict_graph_new
 552                                         PARAMS ((int));
 553 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 554 extern int conflict_graph_add           PARAMS ((conflict_graph,
 555                                                  int, int));
 556 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 557                                                  int, int));
 558 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 559                                                  conflict_graph_enum_fn,
 560                                                  void *));
 561 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 562                                                  int));
 563 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 564 extern conflict_graph conflict_graph_compute
 565                                         PARAMS ((regset,
 566                                                  partition));
 567
 568 #endif /* _BASIC_BLOCK_H */