gcc/basic-block.h

   1 /* Define control and data flow tables, and regsets.
   2    Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002
   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
  30 /* Head of register set linked list.  */
  31 typedef bitmap_head regset_head;
  32 /* A pointer to a regset_head.  */
  33 typedef bitmap regset;
  34
  35 /* Initialize a new regset.  */
  36 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, 1)
  37
  38 /* Clear a register set by freeing up the linked list.  */
  39 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  40
  41 /* Copy a register set to another register set.  */
  42 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  43
  44 /* Compare two register sets.  */
  45 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  46
  47 /* `and' a register set with a second register set.  */
  48 #define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)
  49
  50 /* `and' the complement of a register set with a register set.  */
  51 #define AND_COMPL_REG_SET(TO, FROM) \
  52   bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
  53
  54 /* Inclusive or a register set with a second register set.  */
  55 #define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
  56
  57 /* Exclusive or a register set with a second register set.  */
  58 #define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
  59
  60 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  61 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  62   bitmap_ior_and_compl (TO, FROM1, FROM2)
  63
  64 /* Clear a single register in a register set.  */
  65 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  66
  67 /* Set a single register in a register set.  */
  68 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  69
  70 /* Return true if a register is set in a register set.  */
  71 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  72
  73 /* Copy the hard registers in a register set to the hard register set.  */
  74 extern void reg_set_to_hard_reg_set PARAMS ((HARD_REG_SET *, bitmap));
  75 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  76 do {                                                                    \
  77   CLEAR_HARD_REG_SET (TO);                                              \
  78   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  79 } while (0)
  80
  81 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  82    register number and executing CODE for all registers that are set.  */
  83 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE)            \
  84   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)
  85
  86 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  87    REGNUM to the register number and executing CODE for all registers that are
  88    set in the first regset and not set in the second.  */
  89 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  90   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  91
  92 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  93    REGNUM to the register number and executing CODE for all registers that are
  94    set in both regsets.  */
  95 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  96   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  97
  98 /* Allocate a register set with oballoc.  */
  99 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
 100
 101 /* Initialize a register set.  Returns the new register set.  */
 102 #define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD, 1)
 103
 104 /* Do any cleanup needed on a regset when it is no longer used.  */
 105 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
 106
 107 /* Do any one-time initializations needed for regsets.  */
 108 #define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
 109
 110 /* Grow any tables needed when the number of registers is calculated
 111    or extended.  For the linked list allocation, nothing needs to
 112    be done, other than zero the statistics on the first allocation.  */
 113 #define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
 114
 115 /* Type we use to hold basic block counters.  Should be at least 64bit.  */
 116 typedef HOST_WIDEST_INT gcov_type;
 117
 118 /* Control flow edge information.  */
 119 typedef struct edge_def {
 120   /* Links through the predecessor and successor lists.  */
 121   struct edge_def *pred_next, *succ_next;
 122
 123   /* The two blocks at the ends of the edge.  */
 124   struct basic_block_def *src, *dest;
 125
 126   /* Instructions queued on the edge.  */
 127   rtx insns;
 128
 129   /* Auxiliary info specific to a pass.  */
 130   void *aux;
 131
 132   int flags;                    /* see EDGE_* below  */
 133   int probability;              /* biased by REG_BR_PROB_BASE */
 134   gcov_type count;              /* Expected number of executions calculated
 135                                    in profile.c  */
 136 } *edge;
 137
 138 #define EDGE_FALLTHRU           1
 139 #define EDGE_ABNORMAL           2
 140 #define EDGE_ABNORMAL_CALL      4
 141 #define EDGE_EH                 8
 142 #define EDGE_FAKE               16
 143 #define EDGE_DFS_BACK           32
 144 #define EDGE_CAN_FALLTHRU       64
 145
 146 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 147
 148
 149 /* A basic block is a sequence of instructions with only entry and
 150    only one exit.  If any one of the instructions are executed, they
 151    will all be executed, and in sequence from first to last.
 152
 153    There may be COND_EXEC instructions in the basic block.  The
 154    COND_EXEC *instructions* will be executed -- but if the condition
 155    is false the conditionally executed *expressions* will of course
 156    not be executed.  We don't consider the conditionally executed
 157    expression (which might have side-effects) to be in a separate
 158    basic block because the program counter will always be at the same
 159    location after the COND_EXEC instruction, regardless of whether the
 160    condition is true or not.
 161
 162    Basic blocks need not start with a label nor end with a jump insn.
 163    For example, a previous basic block may just "conditionally fall"
 164    into the succeeding basic block, and the last basic block need not
 165    end with a jump insn.  Block 0 is a descendant of the entry block.
 166
 167    A basic block beginning with two labels cannot have notes between
 168    the labels.
 169
 170    Data for jump tables are stored in jump_insns that occur in no
 171    basic block even though these insns can follow or precede insns in
 172    basic blocks.  */
 173
 174 /* Basic block information indexed by block number.  */
 175 typedef struct basic_block_def {
 176   /* The first and last insns of the block.  */
 177   rtx head, end;
 178
 179   /* The first and last trees of the block.  */
 180   tree head_tree;
 181   tree end_tree;
 182
 183   /* The edges into and out of the block.  */
 184   edge pred, succ;
 185
 186   /* Liveness info.  */
 187
 188   /* The registers that are modified within this in block.  */
 189   regset local_set;
 190   /* The registers that are conditionally modified within this block.
 191      In other words, registers that are set only as part of a
 192      COND_EXEC.  */
 193   regset cond_local_set;
 194   /* The registers that are live on entry to this block.
 195
 196      Note that in SSA form, global_live_at_start does not reflect the
 197      use of regs in phi functions, since the liveness of these regs
 198      may depend on which edge was taken into the block.  */
 199   regset global_live_at_start;
 200   /* The registers that are live on exit from this block.  */
 201   regset global_live_at_end;
 202
 203   /* Auxiliary info specific to a pass.  */
 204   void *aux;
 205
 206   /* The index of this block.  */
 207   int index;
 208
 209   /* Previous and next blocks in the chain.  */
 210   struct basic_block_def *prev_bb, *next_bb;
 211
 212   /* The loop depth of this block.  */
 213   int loop_depth;
 214
 215   /* Outermost loop containing the block.  */
 216   struct loop *loop_father;
 217
 218   /* Expected number of executions: calculated in profile.c.  */
 219   gcov_type count;
 220
 221   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 222   int frequency;
 223
 224   /* Various flags.  See BB_* below.  */
 225   int flags;
 226 } *basic_block;
 227
 228 #define BB_FREQ_MAX 10000
 229
 230 /* Masks for basic_block.flags.  */
 231 #define BB_DIRTY                1
 232 #define BB_NEW                  2
 233 #define BB_REACHABLE            4
 234 #define BB_VISITED              8
 235
 236 /* Number of basic blocks in the current function.  */
 237
 238 extern int n_basic_blocks;
 239
 240 /* First free basic block number.  */
 241
 242 extern int last_basic_block;
 243
 244 /* Number of edges in the current function.  */
 245
 246 extern int n_edges;
 247
 248 /* Index by basic block number, get basic block struct info.  */
 249
 250 extern varray_type basic_block_info;
 251
 252 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 253
 254 /* For iterating over basic blocks.  */
 255 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 256   for (BB = FROM; BB != TO; BB = BB->DIR)
 257
 258 #define FOR_EACH_BB(BB) \
 259   FOR_BB_BETWEEN (BB, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
 260
 261 #define FOR_EACH_BB_REVERSE(BB) \
 262   FOR_BB_BETWEEN (BB, EXIT_BLOCK_PTR->prev_bb, ENTRY_BLOCK_PTR, prev_bb)
 263
 264 /* What registers are live at the setjmp call.  */
 265
 266 extern regset regs_live_at_setjmp;
 267
 268 /* Special labels found during CFG build.  */
 269
 270 extern rtx label_value_list, tail_recursion_label_list;
 271
 272 extern struct obstack flow_obstack;
 273
 274 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 275    If the value is REG_BLOCK_GLOBAL (-2),
 276    it means (REG n) is used in more than one basic block.
 277    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 278    This information remains valid for the rest of the compilation
 279    of the current function; it is used to control register allocation.  */
 280
 281 #define REG_BLOCK_UNKNOWN -1
 282 #define REG_BLOCK_GLOBAL -2
 283
 284 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 285 \f
 286 /* Stuff for recording basic block info.  */
 287
 288 #define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
 289 #define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
 290
 291 #define BLOCK_HEAD_TREE(B) (BASIC_BLOCK (B)->head_tree)
 292 #define BLOCK_END_TREE(B) (BASIC_BLOCK (B)->end_tree)
 293
 294 /* Special block numbers [markers] for entry and exit.  */
 295 #define ENTRY_BLOCK (-1)
 296 #define EXIT_BLOCK (-2)
 297
 298 /* Special block number not valid for any block.  */
 299 #define INVALID_BLOCK (-3)
 300
 301 /* Similarly, block pointers for the edge list.  */
 302 extern struct basic_block_def entry_exit_blocks[2];
 303 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
 304 #define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])
 305
 306 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 307 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 308
 309 extern void compute_bb_for_insn         PARAMS ((void));
 310 extern void free_bb_for_insn            PARAMS ((void));
 311 extern void update_bb_for_insn          PARAMS ((basic_block));
 312
 313 extern void free_basic_block_vars       PARAMS ((int));
 314
 315 extern edge split_block                 PARAMS ((basic_block, rtx));
 316 extern basic_block split_edge           PARAMS ((edge));
 317 extern void insert_insn_on_edge         PARAMS ((rtx, edge));
 318
 319 extern void commit_edge_insertions      PARAMS ((void));
 320 extern void commit_edge_insertions_watch_calls  PARAMS ((void));
 321
 322 extern void remove_fake_edges           PARAMS ((void));
 323 extern void add_noreturn_fake_exit_edges        PARAMS ((void));
 324 extern void connect_infinite_loops_to_exit      PARAMS ((void));
 325 extern int flow_call_edges_add          PARAMS ((sbitmap));
 326 extern edge cached_make_edge            PARAMS ((sbitmap *, basic_block,
 327                                                  basic_block, int));
 328 extern edge make_edge                   PARAMS ((basic_block,
 329                                                  basic_block, int));
 330 extern edge make_single_succ_edge       PARAMS ((basic_block,
 331                                                  basic_block, int));
 332 extern void remove_edge                 PARAMS ((edge));
 333 extern void redirect_edge_succ          PARAMS ((edge, basic_block));
 334 extern edge redirect_edge_succ_nodup    PARAMS ((edge, basic_block));
 335 extern void redirect_edge_pred          PARAMS ((edge, basic_block));
 336 extern basic_block create_basic_block_structure PARAMS ((rtx, rtx, rtx, basic_block));
 337 extern basic_block create_basic_block   PARAMS ((rtx, rtx, basic_block));
 338 extern int flow_delete_block            PARAMS ((basic_block));
 339 extern int flow_delete_block_noexpunge  PARAMS ((basic_block));
 340 extern void clear_bb_flags              PARAMS ((void));
 341 extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
 342 extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
 343                                                  basic_block));
 344 extern void tidy_fallthru_edges         PARAMS ((void));
 345 extern void flow_reverse_top_sort_order_compute PARAMS ((int *));
 346 extern int flow_depth_first_order_compute       PARAMS ((int *, int *));
 347 extern void flow_preorder_transversal_compute   PARAMS ((int *));
 348 extern void dump_edge_info              PARAMS ((FILE *, edge, int));
 349 extern void clear_edges                 PARAMS ((void));
 350 extern void mark_critical_edges         PARAMS ((void));
 351 extern rtx first_insn_after_basic_block_note    PARAMS ((basic_block));
 352
 353 /* Dominator information for basic blocks.  */
 354
 355 typedef struct dominance_info *dominance_info;
 356
 357 /* Structure to hold information for each natural loop.  */
 358 struct loop
 359 {
 360   /* Index into loops array.  */
 361   int num;
 362
 363   /* Basic block of loop header.  */
 364   basic_block header;
 365
 366   /* Basic block of loop latch.  */
 367   basic_block latch;
 368
 369   /* Basic block of loop pre-header or NULL if it does not exist.  */
 370   basic_block pre_header;
 371
 372   /* Array of edges along the pre-header extended basic block trace.
 373      The source of the first edge is the root node of pre-header
 374      extended basic block, if it exists.  */
 375   edge *pre_header_edges;
 376
 377   /* Number of edges along the pre_header extended basic block trace.  */
 378   int num_pre_header_edges;
 379
 380   /* The first block in the loop.  This is not necessarily the same as
 381      the loop header.  */
 382   basic_block first;
 383
 384   /* The last block in the loop.  This is not necessarily the same as
 385      the loop latch.  */
 386   basic_block last;
 387
 388   /* Bitmap of blocks contained within the loop.  */
 389   sbitmap nodes;
 390
 391   /* Number of blocks contained within the loop.  */
 392   int num_nodes;
 393
 394   /* Array of edges that enter the loop.  */
 395   edge *entry_edges;
 396
 397   /* Number of edges that enter the loop.  */
 398   int num_entries;
 399
 400   /* Array of edges that exit the loop.  */
 401   edge *exit_edges;
 402
 403   /* Number of edges that exit the loop.  */
 404   int num_exits;
 405
 406   /* Bitmap of blocks that dominate all exits of the loop.  */
 407   sbitmap exits_doms;
 408
 409   /* The loop nesting depth.  */
 410   int depth;
 411
 412   /* Superloops of the loop.  */
 413   struct loop **pred;
 414
 415   /* The height of the loop (enclosed loop levels) within the loop
 416      hierarchy tree.  */
 417   int level;
 418
 419   /* The outer (parent) loop or NULL if outermost loop.  */
 420   struct loop *outer;
 421
 422   /* The first inner (child) loop or NULL if innermost loop.  */
 423   struct loop *inner;
 424
 425   /* Link to the next (sibling) loop.  */
 426   struct loop *next;
 427
 428   /* Non-zero if the loop is invalid (e.g., contains setjmp.).  */
 429   int invalid;
 430
 431   /* Auxiliary info specific to a pass.  */
 432   void *aux;
 433
 434   /* The following are currently used by loop.c but they are likely to
 435      disappear as loop.c is converted to use the CFG.  */
 436
 437   /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP.  */
 438   rtx vtop;
 439
 440   /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
 441      A continue statement will generate a branch to NEXT_INSN (cont).  */
 442   rtx cont;
 443
 444   /* The dominator of cont.  */
 445   rtx cont_dominator;
 446
 447   /* The NOTE_INSN_LOOP_BEG.  */
 448   rtx start;
 449
 450   /* The NOTE_INSN_LOOP_END.  */
 451   rtx end;
 452
 453   /* For a rotated loop that is entered near the bottom,
 454      this is the label at the top.  Otherwise it is zero.  */
 455   rtx top;
 456
 457   /* Place in the loop where control enters.  */
 458   rtx scan_start;
 459
 460   /* The position where to sink insns out of the loop.  */
 461   rtx sink;
 462
 463   /* List of all LABEL_REFs which refer to code labels outside the
 464      loop.  Used by routines that need to know all loop exits, such as
 465      final_biv_value and final_giv_value.
 466
 467      This does not include loop exits due to return instructions.
 468      This is because all bivs and givs are pseudos, and hence must be
 469      dead after a return, so the presense of a return does not affect
 470      any of the optimizations that use this info.  It is simpler to
 471      just not include return instructions on this list.  */
 472   rtx exit_labels;
 473
 474   /* The number of LABEL_REFs on exit_labels for this loop and all
 475      loops nested inside it.  */
 476   int exit_count;
 477 };
 478
 479
 480 /* Structure to hold CFG information about natural loops within a function.  */
 481 struct loops
 482 {
 483   /* Number of natural loops in the function.  */
 484   int num;
 485
 486   /* Maxium nested loop level in the function.  */
 487   int levels;
 488
 489   /* Array of natural loop descriptors (scanning this array in reverse order
 490      will find the inner loops before their enclosing outer loops).  */
 491   struct loop *array;
 492
 493   /* The above array is unused in new loop infrastructure and is kept only for
 494      purposes of the old loop optimizer.  Instead we store just pointers to
 495      loops here.  */
 496   struct loop **parray;
 497
 498   /* Pointer to root of loop heirachy tree.  */
 499   struct loop *tree_root;
 500
 501   /* Information derived from the CFG.  */
 502   struct cfg
 503   {
 504     /* The bitmap vector of dominators or NULL if not computed.  */
 505     dominance_info dom;
 506
 507     /* The ordering of the basic blocks in a depth first search.  */
 508     int *dfs_order;
 509
 510     /* The reverse completion ordering of the basic blocks found in a
 511        depth first search.  */
 512     int *rc_order;
 513   } cfg;
 514
 515   /* Headers shared by multiple loops that should be merged.  */
 516   sbitmap shared_headers;
 517 };
 518
 519 extern int flow_loops_find PARAMS ((struct loops *, int flags));
 520 extern int flow_loops_update PARAMS ((struct loops *, int flags));
 521 extern void flow_loops_free PARAMS ((struct loops *));
 522 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
 523                                      void (*)(const struct loop *,
 524                                               FILE *, int), int));
 525 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
 526                                     void (*)(const struct loop *,
 527                                              FILE *, int), int));
 528 extern int flow_loop_scan PARAMS ((struct loops *, struct loop *, int));
 529 extern void flow_loop_tree_node_add PARAMS ((struct loop *, struct loop *));
 530 extern void flow_loop_tree_node_remove PARAMS ((struct loop *));
 531
 532 /* This structure maintains an edge list vector.  */
 533 struct edge_list
 534 {
 535   int num_blocks;
 536   int num_edges;
 537   edge *index_to_edge;
 538 };
 539
 540 /* This is the value which indicates no edge is present.  */
 541 #define EDGE_INDEX_NO_EDGE      -1
 542
 543 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 544    if there is no edge between the 2 basic blocks.  */
 545 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 546
 547 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 548    block which is either the pred or succ end of the indexed edge.  */
 549 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 550 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 551
 552 /* INDEX_EDGE returns a pointer to the edge.  */
 553 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 554
 555 /* Number of edges in the compressed edge list.  */
 556 #define NUM_EDGES(el)                   ((el)->num_edges)
 557
 558 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 559 #define FALLTHRU_EDGE(bb)               ((bb)->succ->flags & EDGE_FALLTHRU \
 560                                          ? (bb)->succ : (bb)->succ->succ_next)
 561
 562 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 563 #define BRANCH_EDGE(bb)                 ((bb)->succ->flags & EDGE_FALLTHRU \
 564                                          ? (bb)->succ->succ_next : (bb)->succ)
 565
 566 /* Return expected execution frequency of the edge E.  */
 567 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 568                                           * (e)->probability \
 569                                           + REG_BR_PROB_BASE / 2) \
 570                                          / REG_BR_PROB_BASE)
 571
 572 /* Return nonzero if edge is critical.  */
 573 #define EDGE_CRITICAL_P(e)              ((e)->src->succ->succ_next \
 574                                          && (e)->dest->pred->pred_next)
 575
 576 struct edge_list * create_edge_list     PARAMS ((void));
 577 void free_edge_list                     PARAMS ((struct edge_list *));
 578 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 579 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 580 int find_edge_index                     PARAMS ((struct edge_list *,
 581                                                  basic_block, basic_block));
 582
 583
 584 enum update_life_extent
 585 {
 586   UPDATE_LIFE_LOCAL = 0,
 587   UPDATE_LIFE_GLOBAL = 1,
 588   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 589 };
 590
 591 /* Flags for life_analysis and update_life_info.  */
 592
 593 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 594 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 595 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 596 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 597 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 598 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 599                                            by dead code removal.  */
 600 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 601 #define PROP_EQUAL_NOTES        128     /* Take into account REG_EQUAL notes.  */
 602 #define PROP_SCAN_DEAD_STORES   256     /* Scan for dead code.  */
 603 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 604                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 605                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 606                                  | PROP_ALLOW_CFG_CHANGES \
 607                                  | PROP_SCAN_DEAD_STORES)
 608
 609 #define CLEANUP_EXPENSIVE       1       /* Do relativly expensive optimizations
 610                                            except for edge forwarding */
 611 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 612 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 613                                            to care REG_DEAD notes.  */
 614 #define CLEANUP_PRE_SIBCALL     8       /* Do not get confused by code hidden
 615                                            inside call_placeholders..  */
 616 #define CLEANUP_PRE_LOOP        16      /* Take care to preserve syntactic loop
 617                                            notes.  */
 618 #define CLEANUP_UPDATE_LIFE     32      /* Keep life information up to date.  */
 619 #define CLEANUP_THREADING       64      /* Do jump threading.  */
 620 #define CLEANUP_NO_INSN_DEL     128     /* Do not try to delete trivially dead
 621                                            insns.  */
 622 /* Flags for loop discovery.  */
 623
 624 #define LOOP_TREE               1       /* Build loop hierarchy tree.  */
 625 #define LOOP_PRE_HEADER         2       /* Analyse loop pre-header.  */
 626 #define LOOP_ENTRY_EDGES        4       /* Find entry edges.  */
 627 #define LOOP_EXIT_EDGES         8       /* Find exit edges.  */
 628 #define LOOP_EDGES              (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
 629 #define LOOP_ALL               15       /* All of the above  */
 630
 631 extern void life_analysis       PARAMS ((rtx, FILE *, int));
 632 extern int update_life_info     PARAMS ((sbitmap, enum update_life_extent,
 633                                          int));
 634 extern int update_life_info_in_dirty_blocks PARAMS ((enum update_life_extent,
 635                                                       int));
 636 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 637 extern int propagate_block      PARAMS ((basic_block, regset, regset, regset,
 638                                          int));
 639
 640 struct propagate_block_info;
 641 extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
 642 extern struct propagate_block_info *init_propagate_block_info
 643   PARAMS ((basic_block, regset, regset, regset, int));
 644 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
 645
 646 /* In lcm.c */
 647 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 648                                                  sbitmap *, sbitmap *,
 649                                                  sbitmap *, sbitmap **,
 650                                                  sbitmap **));
 651 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 652                                                    sbitmap *, sbitmap *,
 653                                                    sbitmap *, sbitmap **,
 654                                                    sbitmap **));
 655 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 656                                                  sbitmap *, sbitmap *));
 657 extern int optimize_mode_switching      PARAMS ((FILE *));
 658
 659 /* In emit-rtl.c.  */
 660 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 661 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 662
 663 /* In predict.c */
 664 extern void estimate_probability        PARAMS ((struct loops *));
 665 extern void note_prediction_to_br_prob  PARAMS ((void));
 666 extern void expected_value_to_br_prob   PARAMS ((void));
 667 extern void note_prediction_to_br_prob  PARAMS ((void));
 668 extern bool maybe_hot_bb_p              PARAMS ((basic_block));
 669 extern bool probably_cold_bb_p          PARAMS ((basic_block));
 670 extern bool probably_never_executed_bb_p PARAMS ((basic_block));
 671
 672 /* In flow.c */
 673 extern void init_flow                   PARAMS ((void));
 674 extern void reorder_basic_blocks        PARAMS ((void));
 675 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 676 extern void debug_bb                    PARAMS ((basic_block));
 677 extern void debug_bb_n                  PARAMS ((int));
 678 extern void dump_regset                 PARAMS ((regset, FILE *));
 679 extern void debug_regset                PARAMS ((regset));
 680 extern void allocate_reg_life_data      PARAMS ((void));
 681 extern void allocate_bb_life_data       PARAMS ((void));
 682 extern void expunge_block               PARAMS ((basic_block));
 683 extern void link_block                  PARAMS ((basic_block, basic_block));
 684 extern void unlink_block                PARAMS ((basic_block));
 685 extern void compact_blocks              PARAMS ((void));
 686 extern basic_block alloc_block          PARAMS ((void));
 687 extern void find_unreachable_blocks     PARAMS ((void));
 688 extern int delete_noop_moves            PARAMS ((rtx));
 689 extern basic_block redirect_edge_and_branch_force PARAMS ((edge, basic_block));
 690 extern basic_block force_nonfallthru    PARAMS ((edge));
 691 extern bool redirect_edge_and_branch    PARAMS ((edge, basic_block));
 692 extern rtx block_label                  PARAMS ((basic_block));
 693 extern bool forwarder_block_p           PARAMS ((basic_block));
 694 extern bool purge_all_dead_edges        PARAMS ((int));
 695 extern bool purge_dead_edges            PARAMS ((basic_block));
 696 extern void find_sub_basic_blocks       PARAMS ((basic_block));
 697 extern void find_many_sub_basic_blocks  PARAMS ((sbitmap));
 698 extern bool can_fallthru                PARAMS ((basic_block, basic_block));
 699 extern void flow_nodes_print            PARAMS ((const char *, const sbitmap,
 700                                                  FILE *));
 701 extern void flow_edge_list_print        PARAMS ((const char *, const edge *,
 702                                                  int, FILE *));
 703 extern void alloc_aux_for_block         PARAMS ((basic_block, int));
 704 extern void alloc_aux_for_blocks        PARAMS ((int));
 705 extern void clear_aux_for_blocks        PARAMS ((void));
 706 extern void free_aux_for_blocks         PARAMS ((void));
 707 extern void alloc_aux_for_edge          PARAMS ((edge, int));
 708 extern void alloc_aux_for_edges         PARAMS ((int));
 709 extern void clear_aux_for_edges         PARAMS ((void));
 710 extern void free_aux_for_edges          PARAMS ((void));
 711
 712 /* This function is always defined so it can be called from the
 713    debugger, and it is declared extern so we don't get warnings about
 714    it being unused.  */
 715 extern void verify_flow_info            PARAMS ((void));
 716 extern bool flow_loop_outside_edge_p    PARAMS ((const struct loop *, edge));
 717 extern bool flow_loop_nested_p PARAMS ((const struct loop *, const struct loop *));
 718 extern bool flow_bb_inside_loop_p       PARAMS ((const struct loop *, basic_block));
 719 extern basic_block *get_loop_body       PARAMS ((const struct loop *));
 720 extern int dfs_enumerate_from           PARAMS ((basic_block, int,
 721                                          bool (*)(basic_block, void *),
 722                                          basic_block *, int, void *));
 723
 724 extern edge loop_preheader_edge PARAMS ((struct loop *));
 725 extern edge loop_latch_edge PARAMS ((struct loop *));
 726
 727 extern void add_bb_to_loop PARAMS ((basic_block, struct loop *));
 728 extern void remove_bb_from_loops PARAMS ((basic_block));
 729 extern struct loop * find_common_loop PARAMS ((struct loop *, struct loop *));
 730
 731 extern void verify_loop_structure PARAMS ((struct loops *, int));
 732 #define VLS_EXPECT_PREHEADERS 1
 733 #define VLS_EXPECT_SIMPLE_LATCHES 2
 734
 735 typedef struct conflict_graph_def *conflict_graph;
 736
 737 /* Callback function when enumerating conflicts.  The arguments are
 738    the smaller and larger regno in the conflict.  Returns zero if
 739    enumeration is to continue, non-zero to halt enumeration.  */
 740 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
 741
 742
 743 /* Prototypes of operations on conflict graphs.  */
 744
 745 extern conflict_graph conflict_graph_new
 746                                         PARAMS ((int));
 747 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 748 extern int conflict_graph_add           PARAMS ((conflict_graph,
 749                                                  int, int));
 750 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 751                                                  int, int));
 752 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 753                                                  conflict_graph_enum_fn,
 754                                                  void *));
 755 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 756                                                  int));
 757 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 758 extern conflict_graph conflict_graph_compute
 759                                         PARAMS ((regset,
 760                                                  partition));
 761 extern bool mark_dfs_back_edges         PARAMS ((void));
 762 extern void set_edge_can_fallthru_flag  PARAMS ((void));
 763 extern void update_br_prob_note         PARAMS ((basic_block));
 764 extern void fixup_abnormal_edges        PARAMS ((void));
 765 extern bool can_hoist_insn_p            PARAMS ((rtx, rtx, regset));
 766 extern rtx hoist_insn_after             PARAMS ((rtx, rtx, rtx, rtx));
 767 extern rtx hoist_insn_to_edge           PARAMS ((rtx, edge, rtx, rtx));
 768
 769 /* In dominance.c */
 770
 771 enum cdi_direction
 772 {
 773   CDI_DOMINATORS,
 774   CDI_POST_DOMINATORS
 775 };
 776
 777 extern dominance_info calculate_dominance_info  PARAMS ((enum cdi_direction));
 778 extern void free_dominance_info                 PARAMS ((dominance_info));
 779 extern basic_block nearest_common_dominator     PARAMS ((dominance_info,
 780                                                  basic_block, basic_block));
 781 extern void set_immediate_dominator     PARAMS ((dominance_info,
 782                                                  basic_block, basic_block));
 783 extern basic_block get_immediate_dominator      PARAMS ((dominance_info,
 784                                                  basic_block));
 785 extern bool dominated_by_p      PARAMS ((dominance_info, basic_block, basic_block));
 786 extern int get_dominated_by PARAMS ((dominance_info, basic_block, basic_block **));
 787 extern void add_to_dominance_info PARAMS ((dominance_info, basic_block));
 788 extern void delete_from_dominance_info PARAMS ((dominance_info, basic_block));
 789 basic_block recount_dominator PARAMS ((dominance_info, basic_block));
 790 extern void redirect_immediate_dominators PARAMS ((dominance_info, basic_block,
 791                                                  basic_block));
 792 void iterate_fix_dominators PARAMS ((dominance_info, basic_block *, int));
 793 extern void verify_dominators PARAMS ((dominance_info));
 794 #endif /* GCC_BASIC_BLOCK_H */