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