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