gcc/basic-block.h

   1 /* Define control and data flow tables, and regsets.
   2    Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001 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 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
  29 #ifndef TREE_CODE
  30 union tree_node;
  31 #define tree union tree_node *
  32 #endif
  33
  34 /* Head of register set linked list.  */
  35 typedef bitmap_head regset_head;
  36 /* A pointer to a regset_head.  */
  37 typedef bitmap regset;
  38
  39 /* Initialize a new regset.  */
  40 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD)
  41
  42 /* Clear a register set by freeing up the linked list.  */
  43 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  44
  45 /* Copy a register set to another register set.  */
  46 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  47
  48 /* Compare two register sets.  */
  49 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  50
  51 /* `and' a register set with a second register set.  */
  52 #define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)
  53
  54 /* `and' the complement of a register set with a register set.  */
  55 #define AND_COMPL_REG_SET(TO, FROM) \
  56   bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
  57
  58 /* Inclusive or a register set with a second register set.  */
  59 #define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
  60
  61 /* Exclusive or a register set with a second register set.  */
  62 #define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
  63
  64 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  65 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  66   bitmap_ior_and_compl (TO, FROM1, FROM2)
  67
  68 /* Clear a single register in a register set.  */
  69 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  70
  71 /* Set a single register in a register set.  */
  72 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  73
  74 /* Return true if a register is set in a register set.  */
  75 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  76
  77 /* Copy the hard registers in a register set to the hard register set.  */
  78 extern void reg_set_to_hard_reg_set PARAMS ((HARD_REG_SET *, bitmap));
  79 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  80 do {                                                                    \
  81   CLEAR_HARD_REG_SET (TO);                                              \
  82   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  83 } while (0)
  84
  85 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  86    register number and executing CODE for all registers that are set. */
  87 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE)            \
  88   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)
  89
  90 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  91    REGNUM to the register number and executing CODE for all registers that are
  92    set in the first regset and not set in the second. */
  93 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  94   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  95
  96 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  97    REGNUM to the register number and executing CODE for all registers that are
  98    set in both regsets. */
  99 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
 100   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
 101
 102 /* Allocate a register set with oballoc.  */
 103 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
 104
 105 /* Initialize a register set.  Returns the new register set.  */
 106 #define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD)
 107
 108 /* Do any cleanup needed on a regset when it is no longer used.  */
 109 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
 110
 111 /* Do any one-time initializations needed for regsets.  */
 112 #define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
 113
 114 /* Grow any tables needed when the number of registers is calculated
 115    or extended.  For the linked list allocation, nothing needs to
 116    be done, other than zero the statistics on the first allocation.  */
 117 #define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
 118
 119 /* Type we use to hold basic block counters.  Should be at least 64bit.  */
 120 typedef HOST_WIDEST_INT gcov_type;
 121
 122 /* Control flow edge information.  */
 123 typedef struct edge_def {
 124   /* Links through the predecessor and successor lists.  */
 125   struct edge_def *pred_next, *succ_next;
 126
 127   /* The two blocks at the ends of the edge.  */
 128   struct basic_block_def *src, *dest;
 129
 130   /* Instructions queued on the edge.  */
 131   rtx insns;
 132
 133   /* Auxiliary info specific to a pass.  */
 134   void *aux;
 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 } *edge;
 141
 142 #define EDGE_FALLTHRU           1
 143 #define EDGE_CRITICAL           2
 144 #define EDGE_ABNORMAL           4
 145 #define EDGE_ABNORMAL_CALL      8
 146 #define EDGE_EH                 16
 147 #define EDGE_FAKE               32
 148 #define EDGE_DFS_BACK           64
 149
 150 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 151
 152
 153 /* A basic block is a sequence of instructions with only entry and
 154    only one exit.  If any one of the instructions are executed, they
 155    will all be executed, and in sequence from first to last.
 156
 157    There may be COND_EXEC instructions in the basic block.  The
 158    COND_EXEC *instructions* will be executed -- but if the condition
 159    is false the conditionally executed *expressions* will of course
 160    not be executed.  We don't consider the conditionally executed
 161    expression (which might have side-effects) to be in a separate
 162    basic block because the program counter will always be at the same
 163    location after the COND_EXEC instruction, regardless of whether the
 164    condition is true or not.
 165
 166    Basic blocks need not start with a label nor end with a jump insn.
 167    For example, a previous basic block may just "conditionally fall"
 168    into the succeeding basic block, and the last basic block need not
 169    end with a jump insn.  Block 0 is a descendant of the entry block.
 170
 171    A basic block beginning with two labels cannot have notes between
 172    the labels.
 173
 174    Data for jump tables are stored in jump_insns that occur in no
 175    basic block even though these insns can follow or precede insns in
 176    basic blocks.  */
 177
 178 /* Basic block information indexed by block number.  */
 179 typedef struct basic_block_def {
 180   /* The first and last insns of the block.  */
 181   rtx head, end;
 182
 183   /* The first and last trees of the block.  */
 184   tree head_tree;
 185   tree end_tree;
 186
 187   /* The edges into and out of the block.  */
 188   edge pred, succ;
 189
 190   /* Liveness info.  */
 191
 192   /* The registers that are modified within this in block.  */
 193   regset local_set;
 194   /* The registers that are conditionally modified within this block.
 195      In other words, registers that are set only as part of a
 196      COND_EXEC.  */
 197   regset cond_local_set;
 198   /* The registers that are live on entry to this block.
 199
 200      Note that in SSA form, global_live_at_start does not reflect the
 201      use of regs in phi functions, since the liveness of these regs
 202      may depend on which edge was taken into the block.  */
 203   regset global_live_at_start;
 204   /* The registers that are live on exit from this block.  */
 205   regset global_live_at_end;
 206
 207   /* Auxiliary info specific to a pass.  */
 208   void *aux;
 209
 210   /* The index of this block.  */
 211   int index;
 212
 213   /* The loop depth of this block.  */
 214   int loop_depth;
 215
 216   /* Expected number of executions: calculated in profile.c.  */
 217   gcov_type count;
 218
 219   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 220   int frequency;
 221 } *basic_block;
 222
 223 #define BB_FREQ_MAX 10000
 224
 225 /* Number of basic blocks in the current function.  */
 226
 227 extern int n_basic_blocks;
 228
 229 /* Number of edges in the current function.  */
 230
 231 extern int n_edges;
 232
 233 /* Index by basic block number, get basic block struct info.  */
 234
 235 extern varray_type basic_block_info;
 236
 237 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 238
 239 /* What registers are live at the setjmp call.  */
 240
 241 extern regset regs_live_at_setjmp;
 242
 243 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 244    If the value is REG_BLOCK_GLOBAL (-2),
 245    it means (REG n) is used in more than one basic block.
 246    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 247    This information remains valid for the rest of the compilation
 248    of the current function; it is used to control register allocation.  */
 249
 250 #define REG_BLOCK_UNKNOWN -1
 251 #define REG_BLOCK_GLOBAL -2
 252
 253 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 254 \f
 255 /* Stuff for recording basic block info.  */
 256
 257 #define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
 258 #define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
 259
 260 #define BLOCK_HEAD_TREE(B) (BASIC_BLOCK (B)->head_tree)
 261 #define BLOCK_END_TREE(B) (BASIC_BLOCK (B)->end_tree)
 262
 263 /* Special block numbers [markers] for entry and exit.  */
 264 #define ENTRY_BLOCK (-1)
 265 #define EXIT_BLOCK (-2)
 266
 267 /* Special block number not valid for any block. */
 268 #define INVALID_BLOCK (-3)
 269
 270 /* Similarly, block pointers for the edge list.  */
 271 extern struct basic_block_def entry_exit_blocks[2];
 272 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
 273 #define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])
 274
 275 extern varray_type basic_block_for_insn;
 276 #define BLOCK_FOR_INSN(INSN)  VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
 277 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 278
 279 extern void compute_bb_for_insn         PARAMS ((int));
 280 extern void update_bb_for_insn          PARAMS ((basic_block));
 281 extern void set_block_for_insn          PARAMS ((rtx, basic_block));
 282 extern void set_block_for_new_insns     PARAMS ((rtx, basic_block));
 283
 284 extern void free_basic_block_vars       PARAMS ((int));
 285
 286 extern edge split_block                 PARAMS ((basic_block, rtx));
 287 extern basic_block split_edge           PARAMS ((edge));
 288 extern void insert_insn_on_edge         PARAMS ((rtx, edge));
 289 extern void commit_edge_insertions      PARAMS ((void));
 290 extern void remove_fake_edges           PARAMS ((void));
 291 extern void add_noreturn_fake_exit_edges        PARAMS ((void));
 292 extern void connect_infinite_loops_to_exit      PARAMS ((void));
 293 extern int flow_call_edges_add          PARAMS ((sbitmap));
 294 extern rtx flow_delete_insn             PARAMS ((rtx));
 295 extern void flow_delete_insn_chain      PARAMS ((rtx, rtx));
 296 extern void make_edge                   PARAMS ((sbitmap *, basic_block,
 297                                                  basic_block, int));
 298 extern void remove_edge                 PARAMS ((edge));
 299 extern void redirect_edge_succ          PARAMS ((edge, basic_block));
 300 extern void redirect_edge_succ_nodup    PARAMS ((edge, basic_block));
 301 extern void redirect_edge_pred          PARAMS ((edge, basic_block));
 302 extern void create_basic_block          PARAMS ((int, rtx, rtx, rtx));
 303 extern int flow_delete_block            PARAMS ((basic_block));
 304 extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
 305 extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
 306                                                  basic_block));
 307 extern int flow_depth_first_order_compute       PARAMS ((int *, int *));
 308 extern void dump_edge_info              PARAMS ((FILE *, edge, int));
 309 extern void clear_edges                 PARAMS ((void));
 310 extern void mark_critical_edges         PARAMS ((void));
 311 extern rtx first_insn_after_basic_block_note    PARAMS ((basic_block));
 312
 313 /* Structure to hold information for each natural loop.  */
 314 struct loop
 315 {
 316   /* Index into loops array.  */
 317   int num;
 318
 319   /* Basic block of loop header.  */
 320   basic_block header;
 321
 322   /* Basic block of loop latch.  */
 323   basic_block latch;
 324
 325   /* Basic block of loop pre-header or NULL if it does not exist.  */
 326   basic_block pre_header;
 327
 328   /* Array of edges along the pre-header extended basic block trace.
 329      The source of the first edge is the root node of pre-header
 330      extended basic block, if it exists.  */
 331   edge *pre_header_edges;
 332
 333   /* Number of edges along the pre_header extended basic block trace.  */
 334   int num_pre_header_edges;
 335
 336   /* The first block in the loop.  This is not necessarily the same as
 337      the loop header.  */
 338   basic_block first;
 339
 340   /* The last block in the loop.  This is not necessarily the same as
 341      the loop latch.  */
 342   basic_block last;
 343
 344   /* Bitmap of blocks contained within the loop.  */
 345   sbitmap nodes;
 346
 347   /* Number of blocks contained within the loop.  */
 348   int num_nodes;
 349
 350   /* Array of edges that enter the loop.  */
 351   edge *entry_edges;
 352
 353   /* Number of edges that enter the loop.  */
 354   int num_entries;
 355
 356   /* Array of edges that exit the loop.  */
 357   edge *exit_edges;
 358
 359   /* Number of edges that exit the loop.  */
 360   int num_exits;
 361
 362   /* Bitmap of blocks that dominate all exits of the loop.  */
 363   sbitmap exits_doms;
 364
 365   /* The loop nesting depth.  */
 366   int depth;
 367
 368   /* The height of the loop (enclosed loop levels) within the loop
 369      hierarchy tree.  */
 370   int level;
 371
 372   /* The outer (parent) loop or NULL if outermost loop.  */
 373   struct loop *outer;
 374
 375   /* The first inner (child) loop or NULL if innermost loop.  */
 376   struct loop *inner;
 377
 378   /* Link to the next (sibling) loop.  */
 379   struct loop *next;
 380
 381   /* Non-zero if the loop shares a header with another loop.  */
 382   int shared;
 383
 384   /* Non-zero if the loop is invalid (e.g., contains setjmp.).  */
 385   int invalid;
 386
 387   /* Auxiliary info specific to a pass.  */
 388   void *aux;
 389
 390   /* The following are currently used by loop.c but they are likely to
 391      disappear as loop.c is converted to use the CFG.  */
 392
 393   /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP.  */
 394   rtx vtop;
 395
 396   /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
 397      A continue statement will generate a branch to NEXT_INSN (cont).  */
 398   rtx cont;
 399
 400   /* The dominator of cont.  */
 401   rtx cont_dominator;
 402
 403   /* The NOTE_INSN_LOOP_BEG.  */
 404   rtx start;
 405
 406   /* The NOTE_INSN_LOOP_END.  */
 407   rtx end;
 408
 409   /* For a rotated loop that is entered near the bottom,
 410      this is the label at the top.  Otherwise it is zero.  */
 411   rtx top;
 412
 413   /* Place in the loop where control enters.  */
 414   rtx scan_start;
 415
 416   /* The position where to sink insns out of the loop.  */
 417   rtx sink;
 418
 419   /* List of all LABEL_REFs which refer to code labels outside the
 420      loop.  Used by routines that need to know all loop exits, such as
 421      final_biv_value and final_giv_value.
 422
 423      This does not include loop exits due to return instructions.
 424      This is because all bivs and givs are pseudos, and hence must be
 425      dead after a return, so the presense of a return does not affect
 426      any of the optimizations that use this info.  It is simpler to
 427      just not include return instructions on this list.  */
 428   rtx exit_labels;
 429
 430   /* The number of LABEL_REFs on exit_labels for this loop and all
 431      loops nested inside it.  */
 432   int exit_count;
 433 };
 434
 435
 436 /* Structure to hold CFG information about natural loops within a function.  */
 437 struct loops
 438 {
 439   /* Number of natural loops in the function.  */
 440   int num;
 441
 442   /* Maxium nested loop level in the function.  */
 443   int levels;
 444
 445   /* Array of natural loop descriptors (scanning this array in reverse order
 446      will find the inner loops before their enclosing outer loops).  */
 447   struct loop *array;
 448
 449   /* Pointer to root of loop heirachy tree.  */
 450   struct loop *tree_root;
 451
 452   /* Information derived from the CFG.  */
 453   struct cfg
 454   {
 455     /* The bitmap vector of dominators or NULL if not computed.  */
 456     sbitmap *dom;
 457
 458     /* The ordering of the basic blocks in a depth first search.  */
 459     int *dfs_order;
 460
 461     /* The reverse completion ordering of the basic blocks found in a
 462        depth first search.  */
 463     int *rc_order;
 464   } cfg;
 465
 466   /* Headers shared by multiple loops that should be merged.  */
 467   sbitmap shared_headers;
 468 };
 469
 470 extern int flow_loops_find PARAMS ((struct loops *, int flags));
 471 extern int flow_loops_update PARAMS ((struct loops *, int flags));
 472 extern void flow_loops_free PARAMS ((struct loops *));
 473 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
 474                                      void (*)(const struct loop *,
 475                                               FILE *, int), int));
 476 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
 477                                     void (*)(const struct loop *,
 478                                              FILE *, int), int));
 479 extern int flow_loop_scan PARAMS ((struct loops *, struct loop *, int));
 480
 481 /* This structure maintains an edge list vector.  */
 482 struct edge_list
 483 {
 484   int num_blocks;
 485   int num_edges;
 486   edge *index_to_edge;
 487 };
 488
 489 /* This is the value which indicates no edge is present.  */
 490 #define EDGE_INDEX_NO_EDGE      -1
 491
 492 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 493    if there is no edge between the 2 basic blocks.  */
 494 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 495
 496 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 497    block which is either the pred or succ end of the indexed edge.  */
 498 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 499 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 500
 501 /* INDEX_EDGE returns a pointer to the edge.  */
 502 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 503
 504 /* Number of edges in the compressed edge list.  */
 505 #define NUM_EDGES(el)                   ((el)->num_edges)
 506
 507 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 508 #define FALLTHRU_EDGE(bb)               ((bb)->succ->flags & EDGE_FALLTHRU \
 509                                          ? (bb)->succ : (bb)->succ->succ_next)
 510
 511 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 512 #define BRANCH_EDGE(bb)                 ((bb)->succ->flags & EDGE_FALLTHRU \
 513                                          ? (bb)->succ->succ_next : (bb)->succ)
 514
 515 /* Return expected execution frequency of the edge E.  */
 516 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 517                                           * (e)->probability \
 518                                           + REG_BR_PROB_BASE / 2) \
 519                                          / REG_BR_PROB_BASE)
 520
 521 struct edge_list * create_edge_list     PARAMS ((void));
 522 void free_edge_list                     PARAMS ((struct edge_list *));
 523 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 524 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 525 int find_edge_index                     PARAMS ((struct edge_list *,
 526                                                  basic_block, basic_block));
 527
 528
 529 enum update_life_extent
 530 {
 531   UPDATE_LIFE_LOCAL = 0,
 532   UPDATE_LIFE_GLOBAL = 1,
 533   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 534 };
 535
 536 /* Flags for life_analysis and update_life_info.  */
 537
 538 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 539 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 540 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 541 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 542 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 543 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 544                                            by dead code removal.  */
 545 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 546 #define PROP_FINAL              127     /* All of the above.  */
 547
 548 #define CLEANUP_EXPENSIVE       1       /* Do relativly expensive optimizations
 549                                            except for edge forwarding */
 550 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 551 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 552                                            to care REG_DEAD notes.  */
 553 #define CLEANUP_PRE_SIBCALL     8       /* Do not get confused by code hidden
 554                                            inside call_placeholders..  */
 555 #define CLEANUP_PRE_LOOP        16      /* Take care to preserve syntactic loop
 556                                            notes.  */
 557 /* Flags for loop discovery.  */
 558
 559 #define LOOP_TREE               1       /* Build loop hierarchy tree.  */
 560 #define LOOP_PRE_HEADER         2       /* Analyse loop pre-header.  */
 561 #define LOOP_ENTRY_EDGES        4       /* Find entry edges.  */
 562 #define LOOP_EXIT_EDGES         8       /* Find exit edges.  */
 563 #define LOOP_EDGES              (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
 564 #define LOOP_EXITS_DOMS        16       /* Find nodes that dom. all exits.  */
 565 #define LOOP_ALL               31       /* All of the above  */
 566
 567 extern void life_analysis       PARAMS ((rtx, FILE *, int));
 568 extern void update_life_info    PARAMS ((sbitmap, enum update_life_extent,
 569                                          int));
 570 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 571 extern int propagate_block      PARAMS ((basic_block, regset, regset, regset,
 572                                          int));
 573
 574 struct propagate_block_info;
 575 extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
 576 extern struct propagate_block_info *init_propagate_block_info
 577   PARAMS ((basic_block, regset, regset, regset, int));
 578 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
 579
 580 /* In lcm.c */
 581 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 582                                                  sbitmap *, sbitmap *,
 583                                                  sbitmap *, sbitmap **,
 584                                                  sbitmap **));
 585 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 586                                                    sbitmap *, sbitmap *,
 587                                                    sbitmap *, sbitmap **,
 588                                                    sbitmap **));
 589 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 590                                                  sbitmap *, sbitmap *));
 591 extern int optimize_mode_switching      PARAMS ((FILE *));
 592
 593 /* In emit-rtl.c.  */
 594 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 595 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 596
 597 /* In predict.c */
 598 extern void estimate_probability        PARAMS ((struct loops *));
 599 extern void expected_value_to_br_prob   PARAMS ((void));
 600
 601 /* In flow.c */
 602 extern void init_flow                   PARAMS ((void));
 603 extern void reorder_basic_blocks        PARAMS ((void));
 604 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 605 extern void debug_bb                    PARAMS ((basic_block));
 606 extern void debug_bb_n                  PARAMS ((int));
 607 extern void dump_regset                 PARAMS ((regset, FILE *));
 608 extern void debug_regset                PARAMS ((regset));
 609 extern void allocate_reg_life_data      PARAMS ((void));
 610 extern void allocate_bb_life_data       PARAMS ((void));
 611 extern void find_unreachable_blocks     PARAMS ((void));
 612 extern void delete_noop_moves           PARAMS ((rtx));
 613 extern rtx last_loop_beg_note           PARAMS ((rtx));
 614 extern basic_block redirect_edge_and_branch_force PARAMS ((edge, basic_block));
 615 extern bool redirect_edge_and_branch    PARAMS ((edge, basic_block));
 616 extern rtx block_label                  PARAMS ((basic_block));
 617 extern bool forwarder_block_p           PARAMS ((basic_block));
 618 extern bool purge_all_dead_edges        PARAMS ((void));
 619 extern bool purge_dead_edges            PARAMS ((basic_block));
 620 extern void find_sub_basic_blocks       PARAMS ((basic_block));
 621
 622
 623 /* This function is always defined so it can be called from the
 624    debugger, and it is declared extern so we don't get warnings about
 625    it being unused. */
 626 extern void verify_flow_info            PARAMS ((void));
 627 extern int flow_loop_outside_edge_p     PARAMS ((const struct loop *, edge));
 628
 629 typedef struct conflict_graph_def *conflict_graph;
 630
 631 /* Callback function when enumerating conflicts.  The arguments are
 632    the smaller and larger regno in the conflict.  Returns zero if
 633    enumeration is to continue, non-zero to halt enumeration.  */
 634 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
 635
 636
 637 /* Prototypes of operations on conflict graphs.  */
 638
 639 extern conflict_graph conflict_graph_new
 640                                         PARAMS ((int));
 641 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 642 extern int conflict_graph_add           PARAMS ((conflict_graph,
 643                                                  int, int));
 644 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 645                                                  int, int));
 646 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 647                                                  conflict_graph_enum_fn,
 648                                                  void *));
 649 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 650                                                  int));
 651 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 652 extern conflict_graph conflict_graph_compute
 653                                         PARAMS ((regset,
 654                                                  partition));
 655 extern bool mark_dfs_back_edges         PARAMS ((void));
 656
 657 /* In dominance.c */
 658
 659 enum cdi_direction
 660 {
 661   CDI_DOMINATORS,
 662   CDI_POST_DOMINATORS
 663 };
 664
 665 extern void calculate_dominance_info    PARAMS ((int *, sbitmap *,
 666                                                  enum cdi_direction));
 667
 668 #endif /* GCC_BASIC_BLOCK_H */