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)
  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 int flow_delete_block_noexpunge  PARAMS ((basic_block));
 320 extern void clear_bb_flags              PARAMS ((void));
 321 extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
 322 extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
 323                                                  basic_block));
 324 extern void tidy_fallthru_edges         PARAMS ((void));
 325 extern void flow_reverse_top_sort_order_compute PARAMS ((int *));
 326 extern int flow_depth_first_order_compute       PARAMS ((int *, int *));
 327 extern void flow_preorder_transversal_compute   PARAMS ((int *));
 328 extern void dump_edge_info              PARAMS ((FILE *, edge, int));
 329 extern void clear_edges                 PARAMS ((void));
 330 extern void mark_critical_edges         PARAMS ((void));
 331 extern rtx first_insn_after_basic_block_note    PARAMS ((basic_block));
 332
 333 /* Structure to hold information for each natural loop.  */
 334 struct loop
 335 {
 336   /* Index into loops array.  */
 337   int num;
 338
 339   /* Basic block of loop header.  */
 340   basic_block header;
 341
 342   /* Basic block of loop latch.  */
 343   basic_block latch;
 344
 345   /* Basic block of loop pre-header or NULL if it does not exist.  */
 346   basic_block pre_header;
 347
 348   /* Array of edges along the pre-header extended basic block trace.
 349      The source of the first edge is the root node of pre-header
 350      extended basic block, if it exists.  */
 351   edge *pre_header_edges;
 352
 353   /* Number of edges along the pre_header extended basic block trace.  */
 354   int num_pre_header_edges;
 355
 356   /* The first block in the loop.  This is not necessarily the same as
 357      the loop header.  */
 358   basic_block first;
 359
 360   /* The last block in the loop.  This is not necessarily the same as
 361      the loop latch.  */
 362   basic_block last;
 363
 364   /* Bitmap of blocks contained within the loop.  */
 365   sbitmap nodes;
 366
 367   /* Number of blocks contained within the loop.  */
 368   int num_nodes;
 369
 370   /* Array of edges that enter the loop.  */
 371   edge *entry_edges;
 372
 373   /* Number of edges that enter the loop.  */
 374   int num_entries;
 375
 376   /* Array of edges that exit the loop.  */
 377   edge *exit_edges;
 378
 379   /* Number of edges that exit the loop.  */
 380   int num_exits;
 381
 382   /* Bitmap of blocks that dominate all exits of the loop.  */
 383   sbitmap exits_doms;
 384
 385   /* The loop nesting depth.  */
 386   int depth;
 387
 388   /* The height of the loop (enclosed loop levels) within the loop
 389      hierarchy tree.  */
 390   int level;
 391
 392   /* The outer (parent) loop or NULL if outermost loop.  */
 393   struct loop *outer;
 394
 395   /* The first inner (child) loop or NULL if innermost loop.  */
 396   struct loop *inner;
 397
 398   /* Link to the next (sibling) loop.  */
 399   struct loop *next;
 400
 401   /* Non-zero if the loop shares a header with another loop.  */
 402   int shared;
 403
 404   /* Non-zero if the loop is invalid (e.g., contains setjmp.).  */
 405   int invalid;
 406
 407   /* Auxiliary info specific to a pass.  */
 408   void *aux;
 409
 410   /* The following are currently used by loop.c but they are likely to
 411      disappear as loop.c is converted to use the CFG.  */
 412
 413   /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP.  */
 414   rtx vtop;
 415
 416   /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
 417      A continue statement will generate a branch to NEXT_INSN (cont).  */
 418   rtx cont;
 419
 420   /* The dominator of cont.  */
 421   rtx cont_dominator;
 422
 423   /* The NOTE_INSN_LOOP_BEG.  */
 424   rtx start;
 425
 426   /* The NOTE_INSN_LOOP_END.  */
 427   rtx end;
 428
 429   /* For a rotated loop that is entered near the bottom,
 430      this is the label at the top.  Otherwise it is zero.  */
 431   rtx top;
 432
 433   /* Place in the loop where control enters.  */
 434   rtx scan_start;
 435
 436   /* The position where to sink insns out of the loop.  */
 437   rtx sink;
 438
 439   /* List of all LABEL_REFs which refer to code labels outside the
 440      loop.  Used by routines that need to know all loop exits, such as
 441      final_biv_value and final_giv_value.
 442
 443      This does not include loop exits due to return instructions.
 444      This is because all bivs and givs are pseudos, and hence must be
 445      dead after a return, so the presense of a return does not affect
 446      any of the optimizations that use this info.  It is simpler to
 447      just not include return instructions on this list.  */
 448   rtx exit_labels;
 449
 450   /* The number of LABEL_REFs on exit_labels for this loop and all
 451      loops nested inside it.  */
 452   int exit_count;
 453 };
 454
 455
 456 /* Structure to hold CFG information about natural loops within a function.  */
 457 struct loops
 458 {
 459   /* Number of natural loops in the function.  */
 460   int num;
 461
 462   /* Maxium nested loop level in the function.  */
 463   int levels;
 464
 465   /* Array of natural loop descriptors (scanning this array in reverse order
 466      will find the inner loops before their enclosing outer loops).  */
 467   struct loop *array;
 468
 469   /* Pointer to root of loop heirachy tree.  */
 470   struct loop *tree_root;
 471
 472   /* Information derived from the CFG.  */
 473   struct cfg
 474   {
 475     /* The bitmap vector of dominators or NULL if not computed.  */
 476     sbitmap *dom;
 477
 478     /* The ordering of the basic blocks in a depth first search.  */
 479     int *dfs_order;
 480
 481     /* The reverse completion ordering of the basic blocks found in a
 482        depth first search.  */
 483     int *rc_order;
 484   } cfg;
 485
 486   /* Headers shared by multiple loops that should be merged.  */
 487   sbitmap shared_headers;
 488 };
 489
 490 extern int flow_loops_find PARAMS ((struct loops *, int flags));
 491 extern int flow_loops_update PARAMS ((struct loops *, int flags));
 492 extern void flow_loops_free PARAMS ((struct loops *));
 493 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
 494                                      void (*)(const struct loop *,
 495                                               FILE *, int), int));
 496 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
 497                                     void (*)(const struct loop *,
 498                                              FILE *, int), int));
 499 extern int flow_loop_scan PARAMS ((struct loops *, struct loop *, int));
 500
 501 /* This structure maintains an edge list vector.  */
 502 struct edge_list
 503 {
 504   int num_blocks;
 505   int num_edges;
 506   edge *index_to_edge;
 507 };
 508
 509 /* This is the value which indicates no edge is present.  */
 510 #define EDGE_INDEX_NO_EDGE      -1
 511
 512 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 513    if there is no edge between the 2 basic blocks.  */
 514 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 515
 516 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 517    block which is either the pred or succ end of the indexed edge.  */
 518 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 519 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 520
 521 /* INDEX_EDGE returns a pointer to the edge.  */
 522 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 523
 524 /* Number of edges in the compressed edge list.  */
 525 #define NUM_EDGES(el)                   ((el)->num_edges)
 526
 527 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 528 #define FALLTHRU_EDGE(bb)               ((bb)->succ->flags & EDGE_FALLTHRU \
 529                                          ? (bb)->succ : (bb)->succ->succ_next)
 530
 531 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 532 #define BRANCH_EDGE(bb)                 ((bb)->succ->flags & EDGE_FALLTHRU \
 533                                          ? (bb)->succ->succ_next : (bb)->succ)
 534
 535 /* Return expected execution frequency of the edge E.  */
 536 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 537                                           * (e)->probability \
 538                                           + REG_BR_PROB_BASE / 2) \
 539                                          / REG_BR_PROB_BASE)
 540
 541 /* Return nonzero if edge is critical.  */
 542 #define EDGE_CRITICAL_P(e)              ((e)->src->succ->succ_next \
 543                                          && (e)->dest->pred->pred_next)
 544
 545 struct edge_list * create_edge_list     PARAMS ((void));
 546 void free_edge_list                     PARAMS ((struct edge_list *));
 547 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 548 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 549 int find_edge_index                     PARAMS ((struct edge_list *,
 550                                                  basic_block, basic_block));
 551
 552
 553 enum update_life_extent
 554 {
 555   UPDATE_LIFE_LOCAL = 0,
 556   UPDATE_LIFE_GLOBAL = 1,
 557   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 558 };
 559
 560 /* Flags for life_analysis and update_life_info.  */
 561
 562 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 563 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 564 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 565 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 566 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 567 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 568                                            by dead code removal.  */
 569 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 570 #define PROP_EQUAL_NOTES        128     /* Take into account REG_EQUAL notes.  */
 571 #define PROP_FINAL              127     /* All of the above.  */
 572
 573 #define CLEANUP_EXPENSIVE       1       /* Do relativly expensive optimizations
 574                                            except for edge forwarding */
 575 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 576 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 577                                            to care REG_DEAD notes.  */
 578 #define CLEANUP_PRE_SIBCALL     8       /* Do not get confused by code hidden
 579                                            inside call_placeholders..  */
 580 #define CLEANUP_PRE_LOOP        16      /* Take care to preserve syntactic loop
 581                                            notes.  */
 582 #define CLEANUP_UPDATE_LIFE     32      /* Keep life information up to date.  */
 583 #define CLEANUP_THREADING       64      /* Do jump threading.  */
 584 /* Flags for loop discovery.  */
 585
 586 #define LOOP_TREE               1       /* Build loop hierarchy tree.  */
 587 #define LOOP_PRE_HEADER         2       /* Analyse loop pre-header.  */
 588 #define LOOP_ENTRY_EDGES        4       /* Find entry edges.  */
 589 #define LOOP_EXIT_EDGES         8       /* Find exit edges.  */
 590 #define LOOP_EDGES              (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
 591 #define LOOP_EXITS_DOMS        16       /* Find nodes that dom. all exits.  */
 592 #define LOOP_ALL               31       /* All of the above  */
 593
 594 extern void life_analysis       PARAMS ((rtx, FILE *, int));
 595 extern int update_life_info     PARAMS ((sbitmap, enum update_life_extent,
 596                                          int));
 597 extern int update_life_info_in_dirty_blocks PARAMS ((enum update_life_extent,
 598                                                       int));
 599 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 600 extern int propagate_block      PARAMS ((basic_block, regset, regset, regset,
 601                                          int));
 602
 603 struct propagate_block_info;
 604 extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
 605 extern struct propagate_block_info *init_propagate_block_info
 606   PARAMS ((basic_block, regset, regset, regset, int));
 607 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
 608
 609 /* In lcm.c */
 610 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 611                                                  sbitmap *, sbitmap *,
 612                                                  sbitmap *, sbitmap **,
 613                                                  sbitmap **));
 614 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 615                                                    sbitmap *, sbitmap *,
 616                                                    sbitmap *, sbitmap **,
 617                                                    sbitmap **));
 618 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 619                                                  sbitmap *, sbitmap *));
 620 extern int optimize_mode_switching      PARAMS ((FILE *));
 621
 622 /* In emit-rtl.c.  */
 623 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 624 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 625
 626 /* In predict.c */
 627 extern void estimate_probability        PARAMS ((struct loops *));
 628 extern void expected_value_to_br_prob   PARAMS ((void));
 629
 630 /* In flow.c */
 631 extern void init_flow                   PARAMS ((void));
 632 extern void reorder_basic_blocks        PARAMS ((void));
 633 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 634 extern void debug_bb                    PARAMS ((basic_block));
 635 extern void debug_bb_n                  PARAMS ((int));
 636 extern void dump_regset                 PARAMS ((regset, FILE *));
 637 extern void debug_regset                PARAMS ((regset));
 638 extern void allocate_reg_life_data      PARAMS ((void));
 639 extern void allocate_bb_life_data       PARAMS ((void));
 640 extern void expunge_block               PARAMS ((basic_block));
 641 extern void expunge_block_nocompact     PARAMS ((basic_block));
 642 extern basic_block alloc_block          PARAMS ((void));
 643 extern void find_unreachable_blocks     PARAMS ((void));
 644 extern int delete_noop_moves            PARAMS ((rtx));
 645 extern basic_block redirect_edge_and_branch_force PARAMS ((edge, basic_block));
 646 extern basic_block force_nonfallthru    PARAMS ((edge));
 647 extern bool redirect_edge_and_branch    PARAMS ((edge, basic_block));
 648 extern rtx block_label                  PARAMS ((basic_block));
 649 extern bool forwarder_block_p           PARAMS ((basic_block));
 650 extern bool purge_all_dead_edges        PARAMS ((int));
 651 extern bool purge_dead_edges            PARAMS ((basic_block));
 652 extern void find_sub_basic_blocks       PARAMS ((basic_block));
 653 extern void find_many_sub_basic_blocks  PARAMS ((sbitmap));
 654 extern bool can_fallthru                PARAMS ((basic_block, basic_block));
 655 extern void flow_nodes_print            PARAMS ((const char *, const sbitmap,
 656                                                  FILE *));
 657 extern void flow_edge_list_print        PARAMS ((const char *, const edge *,
 658                                                  int, FILE *));
 659 extern void alloc_aux_for_block         PARAMS ((basic_block, int));
 660 extern void alloc_aux_for_blocks        PARAMS ((int));
 661 extern void clear_aux_for_blocks        PARAMS ((void));
 662 extern void free_aux_for_blocks         PARAMS ((void));
 663 extern void alloc_aux_for_edge          PARAMS ((edge, int));
 664 extern void alloc_aux_for_edges         PARAMS ((int));
 665 extern void clear_aux_for_edges         PARAMS ((void));
 666 extern void free_aux_for_edges          PARAMS ((void));
 667
 668 /* This function is always defined so it can be called from the
 669    debugger, and it is declared extern so we don't get warnings about
 670    it being unused.  */
 671 extern void verify_flow_info            PARAMS ((void));
 672 extern int flow_loop_outside_edge_p     PARAMS ((const struct loop *, edge));
 673
 674 typedef struct conflict_graph_def *conflict_graph;
 675
 676 /* Callback function when enumerating conflicts.  The arguments are
 677    the smaller and larger regno in the conflict.  Returns zero if
 678    enumeration is to continue, non-zero to halt enumeration.  */
 679 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
 680
 681
 682 /* Prototypes of operations on conflict graphs.  */
 683
 684 extern conflict_graph conflict_graph_new
 685                                         PARAMS ((int));
 686 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 687 extern int conflict_graph_add           PARAMS ((conflict_graph,
 688                                                  int, int));
 689 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 690                                                  int, int));
 691 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 692                                                  conflict_graph_enum_fn,
 693                                                  void *));
 694 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 695                                                  int));
 696 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 697 extern conflict_graph conflict_graph_compute
 698                                         PARAMS ((regset,
 699                                                  partition));
 700 extern bool mark_dfs_back_edges         PARAMS ((void));
 701 extern void update_br_prob_note         PARAMS ((basic_block));
 702 extern void fixup_abnormal_edges        PARAMS ((void));
 703
 704 /* In dominance.c */
 705
 706 enum cdi_direction
 707 {
 708   CDI_DOMINATORS,
 709   CDI_POST_DOMINATORS
 710 };
 711
 712 extern void calculate_dominance_info    PARAMS ((int *, sbitmap *,
 713                                                  enum cdi_direction));
 714
 715 #endif /* GCC_BASIC_BLOCK_H */