gcc/basic-block.h

   1 /* Define control and data flow tables, and regsets.
   2    Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001
   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)
  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)
 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
 145 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 146
 147
 148 /* A basic block is a sequence of instructions with only entry and
 149    only one exit.  If any one of the instructions are executed, they
 150    will all be executed, and in sequence from first to last.
 151
 152    There may be COND_EXEC instructions in the basic block.  The
 153    COND_EXEC *instructions* will be executed -- but if the condition
 154    is false the conditionally executed *expressions* will of course
 155    not be executed.  We don't consider the conditionally executed
 156    expression (which might have side-effects) to be in a separate
 157    basic block because the program counter will always be at the same
 158    location after the COND_EXEC instruction, regardless of whether the
 159    condition is true or not.
 160
 161    Basic blocks need not start with a label nor end with a jump insn.
 162    For example, a previous basic block may just "conditionally fall"
 163    into the succeeding basic block, and the last basic block need not
 164    end with a jump insn.  Block 0 is a descendant of the entry block.
 165
 166    A basic block beginning with two labels cannot have notes between
 167    the labels.
 168
 169    Data for jump tables are stored in jump_insns that occur in no
 170    basic block even though these insns can follow or precede insns in
 171    basic blocks.  */
 172
 173 /* Basic block information indexed by block number.  */
 174 typedef struct basic_block_def {
 175   /* The first and last insns of the block.  */
 176   rtx head, end;
 177
 178   /* The first and last trees of the block.  */
 179   tree head_tree;
 180   tree end_tree;
 181
 182   /* The edges into and out of the block.  */
 183   edge pred, succ;
 184
 185   /* Liveness info.  */
 186
 187   /* The registers that are modified within this in block.  */
 188   regset local_set;
 189   /* The registers that are conditionally modified within this block.
 190      In other words, registers that are set only as part of a
 191      COND_EXEC.  */
 192   regset cond_local_set;
 193   /* The registers that are live on entry to this block.
 194
 195      Note that in SSA form, global_live_at_start does not reflect the
 196      use of regs in phi functions, since the liveness of these regs
 197      may depend on which edge was taken into the block.  */
 198   regset global_live_at_start;
 199   /* The registers that are live on exit from this block.  */
 200   regset global_live_at_end;
 201
 202   /* Auxiliary info specific to a pass.  */
 203   void *aux;
 204
 205   /* The index of this block.  */
 206   int index;
 207
 208   /* The loop depth of this block.  */
 209   int loop_depth;
 210
 211   /* Expected number of executions: calculated in profile.c.  */
 212   gcov_type count;
 213
 214   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 215   int frequency;
 216
 217   /* Various flags.  See BB_* below.  */
 218   int flags;
 219 } *basic_block;
 220
 221 #define BB_FREQ_MAX 10000
 222
 223 /* Masks for basic_block.flags.  */
 224 #define BB_DIRTY                1
 225 #define BB_NEW                  2
 226 #define BB_REACHABLE            4
 227
 228 /* Number of basic blocks in the current function.  */
 229
 230 extern int n_basic_blocks;
 231
 232 /* Number of edges in the current function.  */
 233
 234 extern int n_edges;
 235
 236 /* Index by basic block number, get basic block struct info.  */
 237
 238 extern varray_type basic_block_info;
 239
 240 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 241
 242 /* What registers are live at the setjmp call.  */
 243
 244 extern regset regs_live_at_setjmp;
 245
 246 /* Special labels found during CFG build.  */
 247
 248 extern rtx label_value_list, tail_recursion_label_list;
 249
 250 extern struct obstack flow_obstack;
 251
 252 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 253    If the value is REG_BLOCK_GLOBAL (-2),
 254    it means (REG n) is used in more than one basic block.
 255    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 256    This information remains valid for the rest of the compilation
 257    of the current function; it is used to control register allocation.  */
 258
 259 #define REG_BLOCK_UNKNOWN -1
 260 #define REG_BLOCK_GLOBAL -2
 261
 262 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 263 \f
 264 /* Stuff for recording basic block info.  */
 265
 266 #define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
 267 #define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
 268
 269 #define BLOCK_HEAD_TREE(B) (BASIC_BLOCK (B)->head_tree)
 270 #define BLOCK_END_TREE(B) (BASIC_BLOCK (B)->end_tree)
 271
 272 /* Special block numbers [markers] for entry and exit.  */
 273 #define ENTRY_BLOCK (-1)
 274 #define EXIT_BLOCK (-2)
 275
 276 /* Special block number not valid for any block.  */
 277 #define INVALID_BLOCK (-3)
 278
 279 /* Similarly, block pointers for the edge list.  */
 280 extern struct basic_block_def entry_exit_blocks[2];
 281 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
 282 #define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])
 283
 284 extern varray_type basic_block_for_insn;
 285 #define BLOCK_FOR_INSN(INSN)  VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
 286 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 287
 288 extern void compute_bb_for_insn         PARAMS ((int));
 289 extern void free_bb_for_insn            PARAMS ((void));
 290 extern void update_bb_for_insn          PARAMS ((basic_block));
 291 extern void set_block_for_insn          PARAMS ((rtx, basic_block));
 292
 293 extern void free_basic_block_vars       PARAMS ((int));
 294
 295 extern edge split_block                 PARAMS ((basic_block, rtx));
 296 extern basic_block split_edge           PARAMS ((edge));
 297 extern void insert_insn_on_edge         PARAMS ((rtx, edge));
 298
 299 extern void commit_edge_insertions      PARAMS ((void));
 300 extern void commit_edge_insertions_watch_calls  PARAMS ((void));
 301
 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 edge cached_make_edge            PARAMS ((sbitmap *, basic_block,
 307                                                  basic_block, int));
 308 extern edge make_edge                   PARAMS ((basic_block,
 309                                                  basic_block, int));
 310 extern edge make_single_succ_edge       PARAMS ((basic_block,
 311                                                  basic_block, int));
 312 extern void remove_edge                 PARAMS ((edge));
 313 extern void redirect_edge_succ          PARAMS ((edge, basic_block));
 314 extern edge redirect_edge_succ_nodup    PARAMS ((edge, basic_block));
 315 extern void redirect_edge_pred          PARAMS ((edge, basic_block));
 316 extern basic_block create_basic_block_structure PARAMS ((int, rtx, rtx, rtx));
 317 extern basic_block create_basic_block   PARAMS ((int, rtx, rtx));
 318 extern int flow_delete_block            PARAMS ((basic_block));
 319 extern void clear_bb_flags              PARAMS ((void));
 320 extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
 321 extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
 322                                                  basic_block));
 323 extern void tidy_fallthru_edges         PARAMS ((void));
 324 extern void flow_reverse_top_sort_order_compute PARAMS ((int *));
 325 extern int flow_depth_first_order_compute       PARAMS ((int *, int *));
 326 extern void flow_preorder_transversal_compute   PARAMS ((int *));
 327 extern void dump_edge_info              PARAMS ((FILE *, edge, int));
 328 extern void clear_edges                 PARAMS ((void));
 329 extern void mark_critical_edges         PARAMS ((void));
 330 extern rtx first_insn_after_basic_block_note    PARAMS ((basic_block));
 331
 332 /* Structure to hold information for each natural loop.  */
 333 struct loop
 334 {
 335   /* Index into loops array.  */
 336   int num;
 337
 338   /* Basic block of loop header.  */
 339   basic_block header;
 340
 341   /* Basic block of loop latch.  */
 342   basic_block latch;
 343
 344   /* Basic block of loop pre-header or NULL if it does not exist.  */
 345   basic_block pre_header;
 346
 347   /* Array of edges along the pre-header extended basic block trace.
 348      The source of the first edge is the root node of pre-header
 349      extended basic block, if it exists.  */
 350   edge *pre_header_edges;
 351
 352   /* Number of edges along the pre_header extended basic block trace.  */
 353   int num_pre_header_edges;
 354
 355   /* The first block in the loop.  This is not necessarily the same as
 356      the loop header.  */
 357   basic_block first;
 358
 359   /* The last block in the loop.  This is not necessarily the same as
 360      the loop latch.  */
 361   basic_block last;
 362
 363   /* Bitmap of blocks contained within the loop.  */
 364   sbitmap nodes;
 365
 366   /* Number of blocks contained within the loop.  */
 367   int num_nodes;
 368
 369   /* Array of edges that enter the loop.  */
 370   edge *entry_edges;
 371
 372   /* Number of edges that enter the loop.  */
 373   int num_entries;
 374
 375   /* Array of edges that exit the loop.  */
 376   edge *exit_edges;
 377
 378   /* Number of edges that exit the loop.  */
 379   int num_exits;
 380
 381   /* Bitmap of blocks that dominate all exits of the loop.  */
 382   sbitmap exits_doms;
 383
 384   /* The loop nesting depth.  */
 385   int depth;
 386
 387   /* The height of the loop (enclosed loop levels) within the loop
 388      hierarchy tree.  */
 389   int level;
 390
 391   /* The outer (parent) loop or NULL if outermost loop.  */
 392   struct loop *outer;
 393
 394   /* The first inner (child) loop or NULL if innermost loop.  */
 395   struct loop *inner;
 396
 397   /* Link to the next (sibling) loop.  */
 398   struct loop *next;
 399
 400   /* Non-zero if the loop shares a header with another loop.  */
 401   int shared;
 402
 403   /* Non-zero if the loop is invalid (e.g., contains setjmp.).  */
 404   int invalid;
 405
 406   /* Auxiliary info specific to a pass.  */
 407   void *aux;
 408
 409   /* The following are currently used by loop.c but they are likely to
 410      disappear as loop.c is converted to use the CFG.  */
 411
 412   /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP.  */
 413   rtx vtop;
 414
 415   /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
 416      A continue statement will generate a branch to NEXT_INSN (cont).  */
 417   rtx cont;
 418
 419   /* The dominator of cont.  */
 420   rtx cont_dominator;
 421
 422   /* The NOTE_INSN_LOOP_BEG.  */
 423   rtx start;
 424
 425   /* The NOTE_INSN_LOOP_END.  */
 426   rtx end;
 427
 428   /* For a rotated loop that is entered near the bottom,
 429      this is the label at the top.  Otherwise it is zero.  */
 430   rtx top;
 431
 432   /* Place in the loop where control enters.  */
 433   rtx scan_start;
 434
 435   /* The position where to sink insns out of the loop.  */
 436   rtx sink;
 437
 438   /* List of all LABEL_REFs which refer to code labels outside the
 439      loop.  Used by routines that need to know all loop exits, such as
 440      final_biv_value and final_giv_value.
 441
 442      This does not include loop exits due to return instructions.
 443      This is because all bivs and givs are pseudos, and hence must be
 444      dead after a return, so the presense of a return does not affect
 445      any of the optimizations that use this info.  It is simpler to
 446      just not include return instructions on this list.  */
 447   rtx exit_labels;
 448
 449   /* The number of LABEL_REFs on exit_labels for this loop and all
 450      loops nested inside it.  */
 451   int exit_count;
 452 };
 453
 454
 455 /* Structure to hold CFG information about natural loops within a function.  */
 456 struct loops
 457 {
 458   /* Number of natural loops in the function.  */
 459   int num;
 460
 461   /* Maxium nested loop level in the function.  */
 462   int levels;
 463
 464   /* Array of natural loop descriptors (scanning this array in reverse order
 465      will find the inner loops before their enclosing outer loops).  */
 466   struct loop *array;
 467
 468   /* Pointer to root of loop heirachy tree.  */
 469   struct loop *tree_root;
 470
 471   /* Information derived from the CFG.  */
 472   struct cfg
 473   {
 474     /* The bitmap vector of dominators or NULL if not computed.  */
 475     sbitmap *dom;
 476
 477     /* The ordering of the basic blocks in a depth first search.  */
 478     int *dfs_order;
 479
 480     /* The reverse completion ordering of the basic blocks found in a
 481        depth first search.  */
 482     int *rc_order;
 483   } cfg;
 484
 485   /* Headers shared by multiple loops that should be merged.  */
 486   sbitmap shared_headers;
 487 };
 488
 489 extern int flow_loops_find PARAMS ((struct loops *, int flags));
 490 extern int flow_loops_update PARAMS ((struct loops *, int flags));
 491 extern void flow_loops_free PARAMS ((struct loops *));
 492 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
 493                                      void (*)(const struct loop *,
 494                                               FILE *, int), int));
 495 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
 496                                     void (*)(const struct loop *,
 497                                              FILE *, int), int));
 498 extern int flow_loop_scan PARAMS ((struct loops *, struct loop *, int));
 499
 500 /* This structure maintains an edge list vector.  */
 501 struct edge_list
 502 {
 503   int num_blocks;
 504   int num_edges;
 505   edge *index_to_edge;
 506 };
 507
 508 /* This is the value which indicates no edge is present.  */
 509 #define EDGE_INDEX_NO_EDGE      -1
 510
 511 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 512    if there is no edge between the 2 basic blocks.  */
 513 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 514
 515 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 516    block which is either the pred or succ end of the indexed edge.  */
 517 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 518 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 519
 520 /* INDEX_EDGE returns a pointer to the edge.  */
 521 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 522
 523 /* Number of edges in the compressed edge list.  */
 524 #define NUM_EDGES(el)                   ((el)->num_edges)
 525
 526 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 527 #define FALLTHRU_EDGE(bb)               ((bb)->succ->flags & EDGE_FALLTHRU \
 528                                          ? (bb)->succ : (bb)->succ->succ_next)
 529
 530 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 531 #define BRANCH_EDGE(bb)                 ((bb)->succ->flags & EDGE_FALLTHRU \
 532                                          ? (bb)->succ->succ_next : (bb)->succ)
 533
 534 /* Return expected execution frequency of the edge E.  */
 535 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 536                                           * (e)->probability \
 537                                           + REG_BR_PROB_BASE / 2) \
 538                                          / REG_BR_PROB_BASE)
 539
 540 /* Return nonzero if edge is critical.  */
 541 #define EDGE_CRITICAL_P(e)              ((e)->src->succ->succ_next \
 542                                          && (e)->dest->pred->pred_next)
 543
 544 struct edge_list * create_edge_list     PARAMS ((void));
 545 void free_edge_list                     PARAMS ((struct edge_list *));
 546 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 547 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 548 int find_edge_index                     PARAMS ((struct edge_list *,
 549                                                  basic_block, basic_block));
 550
 551
 552 enum update_life_extent
 553 {
 554   UPDATE_LIFE_LOCAL = 0,
 555   UPDATE_LIFE_GLOBAL = 1,
 556   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 557 };
 558
 559 /* Flags for life_analysis and update_life_info.  */
 560
 561 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 562 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 563 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 564 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 565 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 566 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 567                                            by dead code removal.  */
 568 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 569 #define PROP_EQUAL_NOTES        128     /* Take into account REG_EQUAL notes.  */
 570 #define PROP_FINAL              127     /* All of the above.  */
 571
 572 #define CLEANUP_EXPENSIVE       1       /* Do relativly expensive optimizations
 573                                            except for edge forwarding */
 574 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 575 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 576                                            to care REG_DEAD notes.  */
 577 #define CLEANUP_PRE_SIBCALL     8       /* Do not get confused by code hidden
 578                                            inside call_placeholders..  */
 579 #define CLEANUP_PRE_LOOP        16      /* Take care to preserve syntactic loop
 580                                            notes.  */
 581 #define CLEANUP_UPDATE_LIFE     32      /* Keep life information up to date.  */
 582 #define CLEANUP_THREADING       64      /* Do jump threading.  */
 583 /* Flags for loop discovery.  */
 584
 585 #define LOOP_TREE               1       /* Build loop hierarchy tree.  */
 586 #define LOOP_PRE_HEADER         2       /* Analyse loop pre-header.  */
 587 #define LOOP_ENTRY_EDGES        4       /* Find entry edges.  */
 588 #define LOOP_EXIT_EDGES         8       /* Find exit edges.  */
 589 #define LOOP_EDGES              (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
 590 #define LOOP_EXITS_DOMS        16       /* Find nodes that dom. all exits.  */
 591 #define LOOP_ALL               31       /* All of the above  */
 592
 593 extern void life_analysis       PARAMS ((rtx, FILE *, int));
 594 extern int update_life_info     PARAMS ((sbitmap, enum update_life_extent,
 595                                          int));
 596 extern int update_life_info_in_dirty_blocks PARAMS ((enum update_life_extent,
 597                                                       int));
 598 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 599 extern int propagate_block      PARAMS ((basic_block, regset, regset, regset,
 600                                          int));
 601
 602 struct propagate_block_info;
 603 extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
 604 extern struct propagate_block_info *init_propagate_block_info
 605   PARAMS ((basic_block, regset, regset, regset, int));
 606 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
 607
 608 /* In lcm.c */
 609 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 610                                                  sbitmap *, sbitmap *,
 611                                                  sbitmap *, sbitmap **,
 612                                                  sbitmap **));
 613 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 614                                                    sbitmap *, sbitmap *,
 615                                                    sbitmap *, sbitmap **,
 616                                                    sbitmap **));
 617 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 618                                                  sbitmap *, sbitmap *));
 619 extern int optimize_mode_switching      PARAMS ((FILE *));
 620
 621 /* In emit-rtl.c.  */
 622 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 623 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 624
 625 /* In predict.c */
 626 extern void estimate_probability        PARAMS ((struct loops *));
 627 extern void expected_value_to_br_prob   PARAMS ((void));
 628
 629 /* In flow.c */
 630 extern void init_flow                   PARAMS ((void));
 631 extern void reorder_basic_blocks        PARAMS ((void));
 632 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 633 extern void debug_bb                    PARAMS ((basic_block));
 634 extern void debug_bb_n                  PARAMS ((int));
 635 extern void dump_regset                 PARAMS ((regset, FILE *));
 636 extern void debug_regset                PARAMS ((regset));
 637 extern void allocate_reg_life_data      PARAMS ((void));
 638 extern void allocate_bb_life_data       PARAMS ((void));
 639 extern void expunge_block               PARAMS ((basic_block));
 640 extern basic_block alloc_block          PARAMS ((void));
 641 extern void find_unreachable_blocks     PARAMS ((void));
 642 extern int delete_noop_moves            PARAMS ((rtx));
 643 extern basic_block redirect_edge_and_branch_force PARAMS ((edge, basic_block));
 644 extern basic_block force_nonfallthru    PARAMS ((edge));
 645 extern bool redirect_edge_and_branch    PARAMS ((edge, basic_block));
 646 extern rtx block_label                  PARAMS ((basic_block));
 647 extern bool forwarder_block_p           PARAMS ((basic_block));
 648 extern bool purge_all_dead_edges        PARAMS ((int));
 649 extern bool purge_dead_edges            PARAMS ((basic_block));
 650 extern void find_sub_basic_blocks       PARAMS ((basic_block));
 651 extern void find_many_sub_basic_blocks  PARAMS ((sbitmap));
 652 extern bool can_fallthru                PARAMS ((basic_block, basic_block));
 653 extern void flow_nodes_print            PARAMS ((const char *, const sbitmap,
 654                                                  FILE *));
 655 extern void flow_edge_list_print        PARAMS ((const char *, const edge *,
 656                                                  int, FILE *));
 657 extern void alloc_aux_for_block         PARAMS ((basic_block, int));
 658 extern void alloc_aux_for_blocks        PARAMS ((int));
 659 extern void clear_aux_for_blocks        PARAMS ((void));
 660 extern void free_aux_for_blocks         PARAMS ((void));
 661 extern void alloc_aux_for_edge          PARAMS ((edge, int));
 662 extern void alloc_aux_for_edges         PARAMS ((int));
 663 extern void clear_aux_for_edges         PARAMS ((void));
 664 extern void free_aux_for_edges          PARAMS ((void));
 665
 666 /* This function is always defined so it can be called from the
 667    debugger, and it is declared extern so we don't get warnings about
 668    it being unused.  */
 669 extern void verify_flow_info            PARAMS ((void));
 670 extern int flow_loop_outside_edge_p     PARAMS ((const struct loop *, edge));
 671
 672 typedef struct conflict_graph_def *conflict_graph;
 673
 674 /* Callback function when enumerating conflicts.  The arguments are
 675    the smaller and larger regno in the conflict.  Returns zero if
 676    enumeration is to continue, non-zero to halt enumeration.  */
 677 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
 678
 679
 680 /* Prototypes of operations on conflict graphs.  */
 681
 682 extern conflict_graph conflict_graph_new
 683                                         PARAMS ((int));
 684 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 685 extern int conflict_graph_add           PARAMS ((conflict_graph,
 686                                                  int, int));
 687 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 688                                                  int, int));
 689 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 690                                                  conflict_graph_enum_fn,
 691                                                  void *));
 692 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 693                                                  int));
 694 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 695 extern conflict_graph conflict_graph_compute
 696                                         PARAMS ((regset,
 697                                                  partition));
 698 extern bool mark_dfs_back_edges         PARAMS ((void));
 699 extern void update_br_prob_note         PARAMS ((basic_block));
 700
 701 /* In dominance.c */
 702
 703 enum cdi_direction
 704 {
 705   CDI_DOMINATORS,
 706   CDI_POST_DOMINATORS
 707 };
 708
 709 extern void calculate_dominance_info    PARAMS ((int *, sbitmap *,
 710                                                  enum cdi_direction));
 711
 712 #endif /* GCC_BASIC_BLOCK_H */