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 GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 2, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING.  If not, write to the Free
  18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19 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
 222   /* Various flags.  See BB_* below.  */
 223   int flags;
 224 } *basic_block;
 225
 226 #define BB_FREQ_MAX 10000
 227
 228 /* Masks for basic_block.flags.  */
 229 #define BB_REACHABLE            1
 230
 231 /* Number of basic blocks in the current function.  */
 232
 233 extern int n_basic_blocks;
 234
 235 /* Number of edges in the current function.  */
 236
 237 extern int n_edges;
 238
 239 /* Index by basic block number, get basic block struct info.  */
 240
 241 extern varray_type basic_block_info;
 242
 243 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 244
 245 /* What registers are live at the setjmp call.  */
 246
 247 extern regset regs_live_at_setjmp;
 248
 249 /* Special labels found during CFG build.  */
 250
 251 extern rtx label_value_list, tail_recursion_label_list;
 252
 253 extern struct obstack flow_obstack;
 254
 255 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 256    If the value is REG_BLOCK_GLOBAL (-2),
 257    it means (REG n) is used in more than one basic block.
 258    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 259    This information remains valid for the rest of the compilation
 260    of the current function; it is used to control register allocation.  */
 261
 262 #define REG_BLOCK_UNKNOWN -1
 263 #define REG_BLOCK_GLOBAL -2
 264
 265 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 266 \f
 267 /* Stuff for recording basic block info.  */
 268
 269 #define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
 270 #define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
 271
 272 #define BLOCK_HEAD_TREE(B) (BASIC_BLOCK (B)->head_tree)
 273 #define BLOCK_END_TREE(B) (BASIC_BLOCK (B)->end_tree)
 274
 275 /* Special block numbers [markers] for entry and exit.  */
 276 #define ENTRY_BLOCK (-1)
 277 #define EXIT_BLOCK (-2)
 278
 279 /* Special block number not valid for any block. */
 280 #define INVALID_BLOCK (-3)
 281
 282 /* Similarly, block pointers for the edge list.  */
 283 extern struct basic_block_def entry_exit_blocks[2];
 284 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
 285 #define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])
 286
 287 extern varray_type basic_block_for_insn;
 288 #define BLOCK_FOR_INSN(INSN)  VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
 289 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 290
 291 extern void compute_bb_for_insn         PARAMS ((int));
 292 extern void update_bb_for_insn          PARAMS ((basic_block));
 293 extern void set_block_for_insn          PARAMS ((rtx, basic_block));
 294 extern void set_block_for_new_insns     PARAMS ((rtx, basic_block));
 295
 296 extern void free_basic_block_vars       PARAMS ((int));
 297
 298 extern edge split_block                 PARAMS ((basic_block, rtx));
 299 extern basic_block split_edge           PARAMS ((edge));
 300 extern void insert_insn_on_edge         PARAMS ((rtx, edge));
 301 extern void commit_edge_insertions      PARAMS ((void));
 302 extern void remove_fake_edges           PARAMS ((void));
 303 extern void add_noreturn_fake_exit_edges        PARAMS ((void));
 304 extern void connect_infinite_loops_to_exit      PARAMS ((void));
 305 extern int flow_call_edges_add          PARAMS ((sbitmap));
 306 extern rtx flow_delete_insn             PARAMS ((rtx));
 307 extern void flow_delete_insn_chain      PARAMS ((rtx, rtx));
 308 extern void make_edge                   PARAMS ((sbitmap *, basic_block,
 309                                                  basic_block, int));
 310 extern void remove_edge                 PARAMS ((edge));
 311 extern void redirect_edge_succ          PARAMS ((edge, basic_block));
 312 extern edge redirect_edge_succ_nodup    PARAMS ((edge, basic_block));
 313 extern void redirect_edge_pred          PARAMS ((edge, basic_block));
 314 extern void create_basic_block          PARAMS ((int, rtx, rtx, rtx));
 315 extern int flow_delete_block            PARAMS ((basic_block));
 316 extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
 317 extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
 318                                                  basic_block));
 319 extern void tidy_fallthru_edges         PARAMS ((void));
 320 extern void flow_reverse_top_sort_order_compute PARAMS ((int *));
 321 extern int flow_depth_first_order_compute       PARAMS ((int *, int *));
 322 extern void dump_edge_info              PARAMS ((FILE *, edge, int));
 323 extern void clear_edges                 PARAMS ((void));
 324 extern void mark_critical_edges         PARAMS ((void));
 325 extern rtx first_insn_after_basic_block_note    PARAMS ((basic_block));
 326
 327 /* Structure to hold information for each natural loop.  */
 328 struct loop
 329 {
 330   /* Index into loops array.  */
 331   int num;
 332
 333   /* Basic block of loop header.  */
 334   basic_block header;
 335
 336   /* Basic block of loop latch.  */
 337   basic_block latch;
 338
 339   /* Basic block of loop pre-header or NULL if it does not exist.  */
 340   basic_block pre_header;
 341
 342   /* Array of edges along the pre-header extended basic block trace.
 343      The source of the first edge is the root node of pre-header
 344      extended basic block, if it exists.  */
 345   edge *pre_header_edges;
 346
 347   /* Number of edges along the pre_header extended basic block trace.  */
 348   int num_pre_header_edges;
 349
 350   /* The first block in the loop.  This is not necessarily the same as
 351      the loop header.  */
 352   basic_block first;
 353
 354   /* The last block in the loop.  This is not necessarily the same as
 355      the loop latch.  */
 356   basic_block last;
 357
 358   /* Bitmap of blocks contained within the loop.  */
 359   sbitmap nodes;
 360
 361   /* Number of blocks contained within the loop.  */
 362   int num_nodes;
 363
 364   /* Array of edges that enter the loop.  */
 365   edge *entry_edges;
 366
 367   /* Number of edges that enter the loop.  */
 368   int num_entries;
 369
 370   /* Array of edges that exit the loop.  */
 371   edge *exit_edges;
 372
 373   /* Number of edges that exit the loop.  */
 374   int num_exits;
 375
 376   /* Bitmap of blocks that dominate all exits of the loop.  */
 377   sbitmap exits_doms;
 378
 379   /* The loop nesting depth.  */
 380   int depth;
 381
 382   /* The height of the loop (enclosed loop levels) within the loop
 383      hierarchy tree.  */
 384   int level;
 385
 386   /* The outer (parent) loop or NULL if outermost loop.  */
 387   struct loop *outer;
 388
 389   /* The first inner (child) loop or NULL if innermost loop.  */
 390   struct loop *inner;
 391
 392   /* Link to the next (sibling) loop.  */
 393   struct loop *next;
 394
 395   /* Non-zero if the loop shares a header with another loop.  */
 396   int shared;
 397
 398   /* Non-zero if the loop is invalid (e.g., contains setjmp.).  */
 399   int invalid;
 400
 401   /* Auxiliary info specific to a pass.  */
 402   void *aux;
 403
 404   /* The following are currently used by loop.c but they are likely to
 405      disappear as loop.c is converted to use the CFG.  */
 406
 407   /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP.  */
 408   rtx vtop;
 409
 410   /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
 411      A continue statement will generate a branch to NEXT_INSN (cont).  */
 412   rtx cont;
 413
 414   /* The dominator of cont.  */
 415   rtx cont_dominator;
 416
 417   /* The NOTE_INSN_LOOP_BEG.  */
 418   rtx start;
 419
 420   /* The NOTE_INSN_LOOP_END.  */
 421   rtx end;
 422
 423   /* For a rotated loop that is entered near the bottom,
 424      this is the label at the top.  Otherwise it is zero.  */
 425   rtx top;
 426
 427   /* Place in the loop where control enters.  */
 428   rtx scan_start;
 429
 430   /* The position where to sink insns out of the loop.  */
 431   rtx sink;
 432
 433   /* List of all LABEL_REFs which refer to code labels outside the
 434      loop.  Used by routines that need to know all loop exits, such as
 435      final_biv_value and final_giv_value.
 436
 437      This does not include loop exits due to return instructions.
 438      This is because all bivs and givs are pseudos, and hence must be
 439      dead after a return, so the presense of a return does not affect
 440      any of the optimizations that use this info.  It is simpler to
 441      just not include return instructions on this list.  */
 442   rtx exit_labels;
 443
 444   /* The number of LABEL_REFs on exit_labels for this loop and all
 445      loops nested inside it.  */
 446   int exit_count;
 447 };
 448
 449
 450 /* Structure to hold CFG information about natural loops within a function.  */
 451 struct loops
 452 {
 453   /* Number of natural loops in the function.  */
 454   int num;
 455
 456   /* Maxium nested loop level in the function.  */
 457   int levels;
 458
 459   /* Array of natural loop descriptors (scanning this array in reverse order
 460      will find the inner loops before their enclosing outer loops).  */
 461   struct loop *array;
 462
 463   /* Pointer to root of loop heirachy tree.  */
 464   struct loop *tree_root;
 465
 466   /* Information derived from the CFG.  */
 467   struct cfg
 468   {
 469     /* The bitmap vector of dominators or NULL if not computed.  */
 470     sbitmap *dom;
 471
 472     /* The ordering of the basic blocks in a depth first search.  */
 473     int *dfs_order;
 474
 475     /* The reverse completion ordering of the basic blocks found in a
 476        depth first search.  */
 477     int *rc_order;
 478   } cfg;
 479
 480   /* Headers shared by multiple loops that should be merged.  */
 481   sbitmap shared_headers;
 482 };
 483
 484 extern int flow_loops_find PARAMS ((struct loops *, int flags));
 485 extern int flow_loops_update PARAMS ((struct loops *, int flags));
 486 extern void flow_loops_free PARAMS ((struct loops *));
 487 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
 488                                      void (*)(const struct loop *,
 489                                               FILE *, int), int));
 490 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
 491                                     void (*)(const struct loop *,
 492                                              FILE *, int), int));
 493 extern int flow_loop_scan PARAMS ((struct loops *, struct loop *, int));
 494
 495 /* This structure maintains an edge list vector.  */
 496 struct edge_list
 497 {
 498   int num_blocks;
 499   int num_edges;
 500   edge *index_to_edge;
 501 };
 502
 503 /* This is the value which indicates no edge is present.  */
 504 #define EDGE_INDEX_NO_EDGE      -1
 505
 506 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 507    if there is no edge between the 2 basic blocks.  */
 508 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 509
 510 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 511    block which is either the pred or succ end of the indexed edge.  */
 512 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 513 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 514
 515 /* INDEX_EDGE returns a pointer to the edge.  */
 516 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 517
 518 /* Number of edges in the compressed edge list.  */
 519 #define NUM_EDGES(el)                   ((el)->num_edges)
 520
 521 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 522 #define FALLTHRU_EDGE(bb)               ((bb)->succ->flags & EDGE_FALLTHRU \
 523                                          ? (bb)->succ : (bb)->succ->succ_next)
 524
 525 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 526 #define BRANCH_EDGE(bb)                 ((bb)->succ->flags & EDGE_FALLTHRU \
 527                                          ? (bb)->succ->succ_next : (bb)->succ)
 528
 529 /* Return expected execution frequency of the edge E.  */
 530 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 531                                           * (e)->probability \
 532                                           + REG_BR_PROB_BASE / 2) \
 533                                          / REG_BR_PROB_BASE)
 534
 535 struct edge_list * create_edge_list     PARAMS ((void));
 536 void free_edge_list                     PARAMS ((struct edge_list *));
 537 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 538 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 539 int find_edge_index                     PARAMS ((struct edge_list *,
 540                                                  basic_block, basic_block));
 541
 542
 543 enum update_life_extent
 544 {
 545   UPDATE_LIFE_LOCAL = 0,
 546   UPDATE_LIFE_GLOBAL = 1,
 547   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 548 };
 549
 550 /* Flags for life_analysis and update_life_info.  */
 551
 552 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 553 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 554 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 555 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 556 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 557 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 558                                            by dead code removal.  */
 559 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 560 #define PROP_FINAL              127     /* All of the above.  */
 561
 562 #define CLEANUP_EXPENSIVE       1       /* Do relativly expensive optimizations
 563                                            except for edge forwarding */
 564 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 565 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 566                                            to care REG_DEAD notes.  */
 567 #define CLEANUP_PRE_SIBCALL     8       /* Do not get confused by code hidden
 568                                            inside call_placeholders..  */
 569 #define CLEANUP_PRE_LOOP        16      /* Take care to preserve syntactic loop
 570                                            notes.  */
 571 /* Flags for loop discovery.  */
 572
 573 #define LOOP_TREE               1       /* Build loop hierarchy tree.  */
 574 #define LOOP_PRE_HEADER         2       /* Analyse loop pre-header.  */
 575 #define LOOP_ENTRY_EDGES        4       /* Find entry edges.  */
 576 #define LOOP_EXIT_EDGES         8       /* Find exit edges.  */
 577 #define LOOP_EDGES              (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
 578 #define LOOP_EXITS_DOMS        16       /* Find nodes that dom. all exits.  */
 579 #define LOOP_ALL               31       /* All of the above  */
 580
 581 extern void life_analysis       PARAMS ((rtx, FILE *, int));
 582 extern void update_life_info    PARAMS ((sbitmap, enum update_life_extent,
 583                                          int));
 584 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 585 extern int propagate_block      PARAMS ((basic_block, regset, regset, regset,
 586                                          int));
 587
 588 struct propagate_block_info;
 589 extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
 590 extern struct propagate_block_info *init_propagate_block_info
 591   PARAMS ((basic_block, regset, regset, regset, int));
 592 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
 593
 594 /* In lcm.c */
 595 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 596                                                  sbitmap *, sbitmap *,
 597                                                  sbitmap *, sbitmap **,
 598                                                  sbitmap **));
 599 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 600                                                    sbitmap *, sbitmap *,
 601                                                    sbitmap *, sbitmap **,
 602                                                    sbitmap **));
 603 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 604                                                  sbitmap *, sbitmap *));
 605 extern int optimize_mode_switching      PARAMS ((FILE *));
 606
 607 /* In emit-rtl.c.  */
 608 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 609 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 610
 611 /* In predict.c */
 612 extern void estimate_probability        PARAMS ((struct loops *));
 613 extern void expected_value_to_br_prob   PARAMS ((void));
 614
 615 /* In flow.c */
 616 extern void init_flow                   PARAMS ((void));
 617 extern void reorder_basic_blocks        PARAMS ((void));
 618 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 619 extern void debug_bb                    PARAMS ((basic_block));
 620 extern void debug_bb_n                  PARAMS ((int));
 621 extern void dump_regset                 PARAMS ((regset, FILE *));
 622 extern void debug_regset                PARAMS ((regset));
 623 extern void allocate_reg_life_data      PARAMS ((void));
 624 extern void allocate_bb_life_data       PARAMS ((void));
 625 extern void find_unreachable_blocks     PARAMS ((void));
 626 extern void delete_noop_moves           PARAMS ((rtx));
 627 extern basic_block redirect_edge_and_branch_force PARAMS ((edge, basic_block));
 628 extern bool redirect_edge_and_branch    PARAMS ((edge, basic_block));
 629 extern rtx block_label                  PARAMS ((basic_block));
 630 extern bool forwarder_block_p           PARAMS ((basic_block));
 631 extern bool purge_all_dead_edges        PARAMS ((void));
 632 extern bool purge_dead_edges            PARAMS ((basic_block));
 633 extern void find_sub_basic_blocks       PARAMS ((basic_block));
 634 extern bool can_fallthru                PARAMS ((basic_block, basic_block));
 635 extern void flow_nodes_print            PARAMS ((const char *, const sbitmap,
 636                                                  FILE *));
 637 extern void flow_edge_list_print        PARAMS ((const char *, const edge *,
 638                                                  int, FILE *));
 639
 640 /* This function is always defined so it can be called from the
 641    debugger, and it is declared extern so we don't get warnings about
 642    it being unused. */
 643 extern void verify_flow_info            PARAMS ((void));
 644 extern int flow_loop_outside_edge_p     PARAMS ((const struct loop *, edge));
 645
 646 typedef struct conflict_graph_def *conflict_graph;
 647
 648 /* Callback function when enumerating conflicts.  The arguments are
 649    the smaller and larger regno in the conflict.  Returns zero if
 650    enumeration is to continue, non-zero to halt enumeration.  */
 651 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
 652
 653
 654 /* Prototypes of operations on conflict graphs.  */
 655
 656 extern conflict_graph conflict_graph_new
 657                                         PARAMS ((int));
 658 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 659 extern int conflict_graph_add           PARAMS ((conflict_graph,
 660                                                  int, int));
 661 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 662                                                  int, int));
 663 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 664                                                  conflict_graph_enum_fn,
 665                                                  void *));
 666 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 667                                                  int));
 668 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 669 extern conflict_graph conflict_graph_compute
 670                                         PARAMS ((regset,
 671                                                  partition));
 672 extern bool mark_dfs_back_edges         PARAMS ((void));
 673
 674 /* In dominance.c */
 675
 676 enum cdi_direction
 677 {
 678   CDI_DOMINATORS,
 679   CDI_POST_DOMINATORS
 680 };
 681
 682 extern void calculate_dominance_info    PARAMS ((int *, sbitmap *,
 683                                                  enum cdi_direction));
 684
 685 #endif /* GCC_BASIC_BLOCK_H */