gcc/basic-block.h

   1 /* Define control and data flow tables, and regsets.
   2    Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002, 2003
   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
  31 /* Head of register set linked list.  */
  32 typedef bitmap_head regset_head;
  33 /* A pointer to a regset_head.  */
  34 typedef bitmap regset;
  35
  36 /* Initialize a new regset.  */
  37 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, 1)
  38
  39 /* Clear a register set by freeing up the linked list.  */
  40 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  41
  42 /* Copy a register set to another register set.  */
  43 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  44
  45 /* Compare two register sets.  */
  46 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  47
  48 /* `and' a register set with a second register set.  */
  49 #define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)
  50
  51 /* `and' the complement of a register set with a register set.  */
  52 #define AND_COMPL_REG_SET(TO, FROM) \
  53   bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
  54
  55 /* Inclusive or a register set with a second register set.  */
  56 #define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
  57
  58 /* Exclusive or a register set with a second register set.  */
  59 #define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
  60
  61 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  62 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  63   bitmap_ior_and_compl (TO, FROM1, FROM2)
  64
  65 /* Clear a single register in a register set.  */
  66 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  67
  68 /* Set a single register in a register set.  */
  69 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  70
  71 /* Return true if a register is set in a register set.  */
  72 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  73
  74 /* Copy the hard registers in a register set to the hard register set.  */
  75 extern void reg_set_to_hard_reg_set PARAMS ((HARD_REG_SET *, bitmap));
  76 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  77 do {                                                                    \
  78   CLEAR_HARD_REG_SET (TO);                                              \
  79   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  80 } while (0)
  81
  82 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  83    register number and executing CODE for all registers that are set.  */
  84 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE)            \
  85   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)
  86
  87 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  88    REGNUM to the register number and executing CODE for all registers that are
  89    set in the first regset and not set in the second.  */
  90 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  91   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  92
  93 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  94    REGNUM to the register number and executing CODE for all registers that are
  95    set in both regsets.  */
  96 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  97   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  98
  99 /* Allocate a register set with oballoc.  */
 100 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
 101
 102 /* Initialize a register set.  Returns the new register set.  */
 103 #define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD, 1)
 104
 105 /* Do any cleanup needed on a regset when it is no longer used.  */
 106 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
 107
 108 /* Do any one-time initializations needed for regsets.  */
 109 #define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
 110
 111 /* Grow any tables needed when the number of registers is calculated
 112    or extended.  For the linked list allocation, nothing needs to
 113    be done, other than zero the statistics on the first allocation.  */
 114 #define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
 115
 116 /* Type we use to hold basic block counters.  Should be at least
 117    64bit.  Although a counter cannot be negative, we use a signed
 118    type, because erroneous negative counts can be generated when the
 119    flow graph is manipulated by various optimizations.  A signed type
 120    makes those easy to detect.  */
 121 typedef HOST_WIDEST_INT gcov_type;
 122
 123 /* Control flow edge information.  */
 124 typedef struct edge_def {
 125   /* Links through the predecessor and successor lists.  */
 126   struct edge_def *pred_next, *succ_next;
 127
 128   /* The two blocks at the ends of the edge.  */
 129   struct basic_block_def *src, *dest;
 130
 131   /* Instructions queued on the edge.  */
 132   rtx insns;
 133
 134   /* Auxiliary info specific to a pass.  */
 135   void *aux;
 136
 137   int flags;                    /* see EDGE_* below  */
 138   int probability;              /* biased by REG_BR_PROB_BASE */
 139   gcov_type count;              /* Expected number of executions calculated
 140                                    in profile.c  */
 141 } *edge;
 142
 143 #define EDGE_FALLTHRU           1       /* 'Straight line' flow */
 144 #define EDGE_ABNORMAL           2       /* Strange flow, like computed
 145                                            label, or eh */
 146 #define EDGE_ABNORMAL_CALL      4       /* Call with abnormal exit
 147                                            like an exception, or sibcall */
 148 #define EDGE_EH                 8       /* Exception throw */
 149 #define EDGE_FAKE               16      /* Not a real edge (profile.c) */
 150 #define EDGE_DFS_BACK           32      /* A backwards edge */
 151 #define EDGE_CAN_FALLTHRU       64      /* Candidate for straight line
 152                                            flow.  */
 153 #define EDGE_IRREDUCIBLE_LOOP   128     /* Part of irreducible loop.  */
 154 #define EDGE_SIBCALL            256     /* Edge from sibcall to exit.  */
 155 #define EDGE_ALL_FLAGS          511
 156
 157 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 158
 159 /* Counter summary from the last set of coverage counts read by
 160    profile.c. */
 161 extern const struct gcov_ctr_summary *profile_info;
 162
 163 /* Declared in cfgloop.h.  */
 164 struct loop;
 165 struct loops;
 166
 167 /* A basic block is a sequence of instructions with only entry and
 168    only one exit.  If any one of the instructions are executed, they
 169    will all be executed, and in sequence from first to last.
 170
 171    There may be COND_EXEC instructions in the basic block.  The
 172    COND_EXEC *instructions* will be executed -- but if the condition
 173    is false the conditionally executed *expressions* will of course
 174    not be executed.  We don't consider the conditionally executed
 175    expression (which might have side-effects) to be in a separate
 176    basic block because the program counter will always be at the same
 177    location after the COND_EXEC instruction, regardless of whether the
 178    condition is true or not.
 179
 180    Basic blocks need not start with a label nor end with a jump insn.
 181    For example, a previous basic block may just "conditionally fall"
 182    into the succeeding basic block, and the last basic block need not
 183    end with a jump insn.  Block 0 is a descendant of the entry block.
 184
 185    A basic block beginning with two labels cannot have notes between
 186    the labels.
 187
 188    Data for jump tables are stored in jump_insns that occur in no
 189    basic block even though these insns can follow or precede insns in
 190    basic blocks.  */
 191
 192 /* Basic block information indexed by block number.  */
 193 typedef struct basic_block_def {
 194   /* The first and last insns of the block.  */
 195   rtx head, end;
 196
 197   /* The first and last trees of the block.  */
 198   tree head_tree;
 199   tree end_tree;
 200
 201   /* The edges into and out of the block.  */
 202   edge pred, succ;
 203
 204   /* Liveness info.  */
 205
 206   /* The registers that are modified within this in block.  */
 207   regset local_set;
 208   /* The registers that are conditionally modified within this block.
 209      In other words, registers that are set only as part of a
 210      COND_EXEC.  */
 211   regset cond_local_set;
 212   /* The registers that are live on entry to this block.
 213
 214      Note that in SSA form, global_live_at_start does not reflect the
 215      use of regs in phi functions, since the liveness of these regs
 216      may depend on which edge was taken into the block.  */
 217   regset global_live_at_start;
 218   /* The registers that are live on exit from this block.  */
 219   regset global_live_at_end;
 220
 221   /* Auxiliary info specific to a pass.  */
 222   void *aux;
 223
 224   /* The index of this block.  */
 225   int index;
 226
 227   /* Previous and next blocks in the chain.  */
 228   struct basic_block_def *prev_bb, *next_bb;
 229
 230   /* The loop depth of this block.  */
 231   int loop_depth;
 232
 233   /* Outermost loop containing the block.  */
 234   struct loop *loop_father;
 235
 236   /* Expected number of executions: calculated in profile.c.  */
 237   gcov_type count;
 238
 239   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 240   int frequency;
 241
 242   /* Various flags.  See BB_* below.  */
 243   int flags;
 244 } *basic_block;
 245
 246 #define BB_FREQ_MAX 10000
 247
 248 /* Masks for basic_block.flags.  */
 249 #define BB_DIRTY                1
 250 #define BB_NEW                  2
 251 #define BB_REACHABLE            4
 252 #define BB_VISITED              8
 253 #define BB_IRREDUCIBLE_LOOP     16
 254 #define BB_SUPERBLOCK           32
 255
 256 /* Number of basic blocks in the current function.  */
 257
 258 extern int n_basic_blocks;
 259
 260 /* First free basic block number.  */
 261
 262 extern int last_basic_block;
 263
 264 /* Number of edges in the current function.  */
 265
 266 extern int n_edges;
 267
 268 /* Index by basic block number, get basic block struct info.  */
 269
 270 extern varray_type basic_block_info;
 271
 272 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 273
 274 /* For iterating over basic blocks.  */
 275 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 276   for (BB = FROM; BB != TO; BB = BB->DIR)
 277
 278 #define FOR_EACH_BB(BB) \
 279   FOR_BB_BETWEEN (BB, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
 280
 281 #define FOR_EACH_BB_REVERSE(BB) \
 282   FOR_BB_BETWEEN (BB, EXIT_BLOCK_PTR->prev_bb, ENTRY_BLOCK_PTR, prev_bb)
 283
 284 /* Cycles through _all_ basic blocks, even the fake ones (entry and
 285    exit block).  */
 286
 287 #define FOR_ALL_BB(BB) \
 288   for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
 289
 290 /* What registers are live at the setjmp call.  */
 291
 292 extern regset regs_live_at_setjmp;
 293
 294 /* Special labels found during CFG build.  */
 295
 296 extern GTY(()) rtx label_value_list;
 297 extern GTY(()) rtx tail_recursion_label_list;
 298
 299 extern struct obstack flow_obstack;
 300
 301 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 302    If the value is REG_BLOCK_GLOBAL (-2),
 303    it means (REG n) is used in more than one basic block.
 304    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 305    This information remains valid for the rest of the compilation
 306    of the current function; it is used to control register allocation.  */
 307
 308 #define REG_BLOCK_UNKNOWN -1
 309 #define REG_BLOCK_GLOBAL -2
 310
 311 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 312 \f
 313 /* Stuff for recording basic block info.  */
 314
 315 #define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
 316 #define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
 317
 318 #define BLOCK_HEAD_TREE(B) (BASIC_BLOCK (B)->head_tree)
 319 #define BLOCK_END_TREE(B) (BASIC_BLOCK (B)->end_tree)
 320
 321 /* Special block numbers [markers] for entry and exit.  */
 322 #define ENTRY_BLOCK (-1)
 323 #define EXIT_BLOCK (-2)
 324
 325 /* Special block number not valid for any block.  */
 326 #define INVALID_BLOCK (-3)
 327
 328 /* Similarly, block pointers for the edge list.  */
 329 extern struct basic_block_def entry_exit_blocks[2];
 330 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
 331 #define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])
 332
 333 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 334 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 335
 336 extern void compute_bb_for_insn         PARAMS ((void));
 337 extern void free_bb_for_insn            PARAMS ((void));
 338 extern void update_bb_for_insn          PARAMS ((basic_block));
 339
 340 extern void free_basic_block_vars       PARAMS ((int));
 341
 342 extern void insert_insn_on_edge         PARAMS ((rtx, edge));
 343
 344 extern void commit_edge_insertions      PARAMS ((void));
 345 extern void commit_edge_insertions_watch_calls  PARAMS ((void));
 346
 347 extern void remove_fake_edges           PARAMS ((void));
 348 extern void add_noreturn_fake_exit_edges        PARAMS ((void));
 349 extern void connect_infinite_loops_to_exit      PARAMS ((void));
 350 extern int flow_call_edges_add          PARAMS ((sbitmap));
 351 extern edge unchecked_make_edge         PARAMS ((basic_block,
 352                                                  basic_block, int));
 353 extern edge cached_make_edge            PARAMS ((sbitmap *, basic_block,
 354                                                  basic_block, int));
 355 extern edge make_edge                   PARAMS ((basic_block,
 356                                                  basic_block, int));
 357 extern edge make_single_succ_edge       PARAMS ((basic_block,
 358                                                  basic_block, int));
 359 extern void remove_edge                 PARAMS ((edge));
 360 extern void redirect_edge_succ          PARAMS ((edge, basic_block));
 361 extern edge redirect_edge_succ_nodup    PARAMS ((edge, basic_block));
 362 extern void redirect_edge_pred          PARAMS ((edge, basic_block));
 363 extern basic_block create_basic_block_structure PARAMS ((rtx, rtx, rtx, basic_block));
 364 extern basic_block create_basic_block   PARAMS ((rtx, rtx, basic_block));
 365 extern void clear_bb_flags              PARAMS ((void));
 366 extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
 367 extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
 368                                                  basic_block));
 369 extern void tidy_fallthru_edges         PARAMS ((void));
 370 extern void flow_reverse_top_sort_order_compute PARAMS ((int *));
 371 extern int flow_depth_first_order_compute       PARAMS ((int *, int *));
 372 extern void flow_preorder_transversal_compute   PARAMS ((int *));
 373 extern int dfs_enumerate_from           PARAMS ((basic_block, int,
 374                                                 bool (*)(basic_block, void *),
 375                                                 basic_block *, int, void *));
 376 extern void dump_edge_info              PARAMS ((FILE *, edge, int));
 377 extern void clear_edges                 PARAMS ((void));
 378 extern void mark_critical_edges         PARAMS ((void));
 379 extern rtx first_insn_after_basic_block_note    PARAMS ((basic_block));
 380
 381 /* Dominator information for basic blocks.  */
 382
 383 typedef struct dominance_info *dominance_info;
 384
 385 /* Structure to group all of the information to process IF-THEN and
 386    IF-THEN-ELSE blocks for the conditional execution support.  This
 387    needs to be in a public file in case the IFCVT macros call
 388    functions passing the ce_if_block data structure.  */
 389
 390 typedef struct ce_if_block
 391 {
 392   basic_block test_bb;                  /* First test block.  */
 393   basic_block then_bb;                  /* THEN block.  */
 394   basic_block else_bb;                  /* ELSE block or NULL.  */
 395   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 396   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 397   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 398   int num_and_and_blocks;               /* # of && blocks.  */
 399   int num_or_or_blocks;                 /* # of || blocks.  */
 400   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 401   int and_and_p;                        /* Complex test is &&.  */
 402   int num_then_insns;                   /* # of insns in THEN block.  */
 403   int num_else_insns;                   /* # of insns in ELSE block.  */
 404   int pass;                             /* Pass number.  */
 405
 406 #ifdef IFCVT_EXTRA_FIELDS
 407   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 408 #endif
 409
 410 } ce_if_block_t;
 411
 412 /* This structure maintains an edge list vector.  */
 413 struct edge_list
 414 {
 415   int num_blocks;
 416   int num_edges;
 417   edge *index_to_edge;
 418 };
 419
 420 /* This is the value which indicates no edge is present.  */
 421 #define EDGE_INDEX_NO_EDGE      -1
 422
 423 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 424    if there is no edge between the 2 basic blocks.  */
 425 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 426
 427 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 428    block which is either the pred or succ end of the indexed edge.  */
 429 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 430 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 431
 432 /* INDEX_EDGE returns a pointer to the edge.  */
 433 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 434
 435 /* Number of edges in the compressed edge list.  */
 436 #define NUM_EDGES(el)                   ((el)->num_edges)
 437
 438 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 439 #define FALLTHRU_EDGE(bb)               ((bb)->succ->flags & EDGE_FALLTHRU \
 440                                          ? (bb)->succ : (bb)->succ->succ_next)
 441
 442 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 443 #define BRANCH_EDGE(bb)                 ((bb)->succ->flags & EDGE_FALLTHRU \
 444                                          ? (bb)->succ->succ_next : (bb)->succ)
 445
 446 /* Return expected execution frequency of the edge E.  */
 447 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 448                                           * (e)->probability \
 449                                           + REG_BR_PROB_BASE / 2) \
 450                                          / REG_BR_PROB_BASE)
 451
 452 /* Return nonzero if edge is critical.  */
 453 #define EDGE_CRITICAL_P(e)              ((e)->src->succ->succ_next \
 454                                          && (e)->dest->pred->pred_next)
 455
 456 struct edge_list * create_edge_list     PARAMS ((void));
 457 void free_edge_list                     PARAMS ((struct edge_list *));
 458 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 459 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 460 int find_edge_index                     PARAMS ((struct edge_list *,
 461                                                  basic_block, basic_block));
 462
 463
 464 enum update_life_extent
 465 {
 466   UPDATE_LIFE_LOCAL = 0,
 467   UPDATE_LIFE_GLOBAL = 1,
 468   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 469 };
 470
 471 /* Flags for life_analysis and update_life_info.  */
 472
 473 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 474 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 475 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 476 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 477 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 478 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 479                                            by dead code removal.  */
 480 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 481 #define PROP_EQUAL_NOTES        128     /* Take into account REG_EQUAL notes.  */
 482 #define PROP_SCAN_DEAD_STORES   256     /* Scan for dead code.  */
 483 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 484                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 485                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 486                                  | PROP_ALLOW_CFG_CHANGES \
 487                                  | PROP_SCAN_DEAD_STORES)
 488
 489 #define CLEANUP_EXPENSIVE       1       /* Do relativly expensive optimizations
 490                                            except for edge forwarding */
 491 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 492 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 493                                            to care REG_DEAD notes.  */
 494 #define CLEANUP_PRE_SIBCALL     8       /* Do not get confused by code hidden
 495                                            inside call_placeholders..  */
 496 #define CLEANUP_PRE_LOOP        16      /* Take care to preserve syntactic loop
 497                                            notes.  */
 498 #define CLEANUP_UPDATE_LIFE     32      /* Keep life information up to date.  */
 499 #define CLEANUP_THREADING       64      /* Do jump threading.  */
 500 #define CLEANUP_NO_INSN_DEL     128     /* Do not try to delete trivially dead
 501                                            insns.  */
 502 extern void life_analysis       PARAMS ((rtx, FILE *, int));
 503 extern int update_life_info     PARAMS ((sbitmap, enum update_life_extent,
 504                                          int));
 505 extern int update_life_info_in_dirty_blocks PARAMS ((enum update_life_extent,
 506                                                       int));
 507 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 508 extern int propagate_block      PARAMS ((basic_block, regset, regset, regset,
 509                                          int));
 510
 511 struct propagate_block_info;
 512 extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
 513 extern struct propagate_block_info *init_propagate_block_info
 514   PARAMS ((basic_block, regset, regset, regset, int));
 515 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
 516
 517 /* In lcm.c */
 518 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 519                                                  sbitmap *, sbitmap *,
 520                                                  sbitmap *, sbitmap **,
 521                                                  sbitmap **));
 522 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 523                                                    sbitmap *, sbitmap *,
 524                                                    sbitmap *, sbitmap **,
 525                                                    sbitmap **));
 526 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 527                                                  sbitmap *, sbitmap *));
 528 extern int optimize_mode_switching      PARAMS ((FILE *));
 529
 530 /* In emit-rtl.c.  */
 531 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 532 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 533
 534 /* In predict.c */
 535 extern void estimate_probability        PARAMS ((struct loops *));
 536 extern void note_prediction_to_br_prob  PARAMS ((void));
 537 extern void expected_value_to_br_prob   PARAMS ((void));
 538 extern bool maybe_hot_bb_p              PARAMS ((basic_block));
 539 extern bool probably_cold_bb_p          PARAMS ((basic_block));
 540 extern bool probably_never_executed_bb_p PARAMS ((basic_block));
 541
 542 /* In flow.c */
 543 extern void init_flow                   PARAMS ((void));
 544 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 545 extern void debug_bb                    PARAMS ((basic_block));
 546 extern basic_block debug_bb_n           PARAMS ((int));
 547 extern void dump_regset                 PARAMS ((regset, FILE *));
 548 extern void debug_regset                PARAMS ((regset));
 549 extern void allocate_reg_life_data      PARAMS ((void));
 550 extern void allocate_bb_life_data       PARAMS ((void));
 551 extern void expunge_block               PARAMS ((basic_block));
 552 extern void link_block                  PARAMS ((basic_block, basic_block));
 553 extern void unlink_block                PARAMS ((basic_block));
 554 extern void compact_blocks              PARAMS ((void));
 555 extern basic_block alloc_block          PARAMS ((void));
 556 extern void find_unreachable_blocks     PARAMS ((void));
 557 extern int delete_noop_moves            PARAMS ((rtx));
 558 extern basic_block force_nonfallthru    PARAMS ((edge));
 559 extern rtx block_label                  PARAMS ((basic_block));
 560 extern bool forwarder_block_p           PARAMS ((basic_block));
 561 extern bool purge_all_dead_edges        PARAMS ((int));
 562 extern bool purge_dead_edges            PARAMS ((basic_block));
 563 extern void find_sub_basic_blocks       PARAMS ((basic_block));
 564 extern void find_many_sub_basic_blocks  PARAMS ((sbitmap));
 565 extern bool can_fallthru                PARAMS ((basic_block, basic_block));
 566 extern void flow_nodes_print            PARAMS ((const char *, const sbitmap,
 567                                                  FILE *));
 568 extern void flow_edge_list_print        PARAMS ((const char *, const edge *,
 569                                                  int, FILE *));
 570 extern void alloc_aux_for_block         PARAMS ((basic_block, int));
 571 extern void alloc_aux_for_blocks        PARAMS ((int));
 572 extern void clear_aux_for_blocks        PARAMS ((void));
 573 extern void free_aux_for_blocks         PARAMS ((void));
 574 extern void alloc_aux_for_edge          PARAMS ((edge, int));
 575 extern void alloc_aux_for_edges         PARAMS ((int));
 576 extern void clear_aux_for_edges         PARAMS ((void));
 577 extern void free_aux_for_edges          PARAMS ((void));
 578
 579 /* This function is always defined so it can be called from the
 580    debugger, and it is declared extern so we don't get warnings about
 581    it being unused.  */
 582 extern void verify_flow_info            PARAMS ((void));
 583
 584 typedef struct conflict_graph_def *conflict_graph;
 585
 586 /* Callback function when enumerating conflicts.  The arguments are
 587    the smaller and larger regno in the conflict.  Returns zero if
 588    enumeration is to continue, nonzero to halt enumeration.  */
 589 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
 590
 591
 592 /* Prototypes of operations on conflict graphs.  */
 593
 594 extern conflict_graph conflict_graph_new
 595                                         PARAMS ((int));
 596 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 597 extern int conflict_graph_add           PARAMS ((conflict_graph,
 598                                                  int, int));
 599 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 600                                                  int, int));
 601 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 602                                                  conflict_graph_enum_fn,
 603                                                  void *));
 604 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 605                                                  int));
 606 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 607 extern conflict_graph conflict_graph_compute
 608                                         PARAMS ((regset,
 609                                                  partition));
 610 extern bool mark_dfs_back_edges         PARAMS ((void));
 611 extern void set_edge_can_fallthru_flag  PARAMS ((void));
 612 extern void update_br_prob_note         PARAMS ((basic_block));
 613 extern void fixup_abnormal_edges        PARAMS ((void));
 614 extern bool can_hoist_insn_p            PARAMS ((rtx, rtx, regset));
 615 extern rtx hoist_insn_after             PARAMS ((rtx, rtx, rtx, rtx));
 616 extern rtx hoist_insn_to_edge           PARAMS ((rtx, edge, rtx, rtx));
 617 extern bool inside_basic_block_p        PARAMS ((rtx));
 618 extern bool control_flow_insn_p         PARAMS ((rtx));
 619
 620 /* In bb-reorder.c */
 621 extern void reorder_basic_blocks (void);
 622
 623 /* In dominance.c */
 624
 625 enum cdi_direction
 626 {
 627   CDI_DOMINATORS,
 628   CDI_POST_DOMINATORS
 629 };
 630
 631 extern dominance_info calculate_dominance_info  PARAMS ((enum cdi_direction));
 632 extern void free_dominance_info                 PARAMS ((dominance_info));
 633 extern basic_block nearest_common_dominator     PARAMS ((dominance_info,
 634                                                  basic_block, basic_block));
 635 extern void set_immediate_dominator     PARAMS ((dominance_info,
 636                                                  basic_block, basic_block));
 637 extern basic_block get_immediate_dominator      PARAMS ((dominance_info,
 638                                                  basic_block));
 639 extern bool dominated_by_p      PARAMS ((dominance_info, basic_block, basic_block));
 640 extern int get_dominated_by PARAMS ((dominance_info, basic_block, basic_block **));
 641 extern void add_to_dominance_info PARAMS ((dominance_info, basic_block));
 642 extern void delete_from_dominance_info PARAMS ((dominance_info, basic_block));
 643 basic_block recount_dominator PARAMS ((dominance_info, basic_block));
 644 extern void redirect_immediate_dominators PARAMS ((dominance_info, basic_block,
 645                                                  basic_block));
 646 void iterate_fix_dominators PARAMS ((dominance_info, basic_block *, int));
 647 extern void verify_dominators PARAMS ((dominance_info));
 648
 649 #include "cfghooks.h"
 650
 651 #endif /* GCC_BASIC_BLOCK_H */