gcc/basic-block.h

   1 /* Define control and data flow tables, and regsets.
   2    Copyright (C) 1987, 1997, 1998, 1999, 2000, 2001, 2002
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 #ifndef GCC_BASIC_BLOCK_H
  23 #define GCC_BASIC_BLOCK_H
  24
  25 #include "bitmap.h"
  26 #include "sbitmap.h"
  27 #include "varray.h"
  28 #include "partition.h"
  29
  30 /* Head of register set linked list.  */
  31 typedef bitmap_head regset_head;
  32 /* A pointer to a regset_head.  */
  33 typedef bitmap regset;
  34
  35 /* Initialize a new regset.  */
  36 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD, 1)
  37
  38 /* Clear a register set by freeing up the linked list.  */
  39 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  40
  41 /* Copy a register set to another register set.  */
  42 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  43
  44 /* Compare two register sets.  */
  45 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  46
  47 /* `and' a register set with a second register set.  */
  48 #define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)
  49
  50 /* `and' the complement of a register set with a register set.  */
  51 #define AND_COMPL_REG_SET(TO, FROM) \
  52   bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
  53
  54 /* Inclusive or a register set with a second register set.  */
  55 #define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
  56
  57 /* Exclusive or a register set with a second register set.  */
  58 #define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
  59
  60 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  61 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  62   bitmap_ior_and_compl (TO, FROM1, FROM2)
  63
  64 /* Clear a single register in a register set.  */
  65 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  66
  67 /* Set a single register in a register set.  */
  68 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  69
  70 /* Return true if a register is set in a register set.  */
  71 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  72
  73 /* Copy the hard registers in a register set to the hard register set.  */
  74 extern void reg_set_to_hard_reg_set PARAMS ((HARD_REG_SET *, bitmap));
  75 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  76 do {                                                                    \
  77   CLEAR_HARD_REG_SET (TO);                                              \
  78   reg_set_to_hard_reg_set (&TO, FROM);                                  \
  79 } while (0)
  80
  81 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  82    register number and executing CODE for all registers that are set.  */
  83 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE)            \
  84   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)
  85
  86 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  87    REGNUM to the register number and executing CODE for all registers that are
  88    set in the first regset and not set in the second.  */
  89 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  90   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  91
  92 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  93    REGNUM to the register number and executing CODE for all registers that are
  94    set in both regsets.  */
  95 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  96   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  97
  98 /* Allocate a register set with oballoc.  */
  99 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
 100
 101 /* Initialize a register set.  Returns the new register set.  */
 102 #define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD, 1)
 103
 104 /* Do any cleanup needed on a regset when it is no longer used.  */
 105 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
 106
 107 /* Do any one-time initializations needed for regsets.  */
 108 #define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
 109
 110 /* Grow any tables needed when the number of registers is calculated
 111    or extended.  For the linked list allocation, nothing needs to
 112    be done, other than zero the statistics on the first allocation.  */
 113 #define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
 114
 115 /* Type we use to hold basic block counters.  Should be at least
 116    64bit.  Although a counter cannot be negative, we use a signed
 117    type, because erroneous negative counts can be generated when the
 118    flow graph is manipulated by various optimizations.  A signed type
 119    makes those easy to detect. */
 120 typedef HOST_WIDEST_INT gcov_type;
 121
 122 /* Control flow edge information.  */
 123 typedef struct edge_def {
 124   /* Links through the predecessor and successor lists.  */
 125   struct edge_def *pred_next, *succ_next;
 126
 127   /* The two blocks at the ends of the edge.  */
 128   struct basic_block_def *src, *dest;
 129
 130   /* Instructions queued on the edge.  */
 131   rtx insns;
 132
 133   /* Auxiliary info specific to a pass.  */
 134   void *aux;
 135
 136   int flags;                    /* see EDGE_* below  */
 137   int probability;              /* biased by REG_BR_PROB_BASE */
 138   gcov_type count;              /* Expected number of executions calculated
 139                                    in profile.c  */
 140 } *edge;
 141
 142 #define EDGE_FALLTHRU           1       /* 'Straight line' flow */
 143 #define EDGE_ABNORMAL           2       /* Strange flow, like computed
 144                                            label, or eh */
 145 #define EDGE_ABNORMAL_CALL      4       /* Call with abnormal exit
 146                                            like an exception, or sibcall */
 147 #define EDGE_EH                 8       /* Exception throw */
 148 #define EDGE_FAKE               16      /* Not a real edge (profile.c) */
 149 #define EDGE_DFS_BACK           32      /* A backwards edge */
 150 #define EDGE_CAN_FALLTHRU       64      /* Candidate for straight line
 151                                            flow.  */
 152
 153 #define EDGE_COMPLEX    (EDGE_ABNORMAL | EDGE_ABNORMAL_CALL | EDGE_EH)
 154
 155
 156 /* A basic block is a sequence of instructions with only entry and
 157    only one exit.  If any one of the instructions are executed, they
 158    will all be executed, and in sequence from first to last.
 159
 160    There may be COND_EXEC instructions in the basic block.  The
 161    COND_EXEC *instructions* will be executed -- but if the condition
 162    is false the conditionally executed *expressions* will of course
 163    not be executed.  We don't consider the conditionally executed
 164    expression (which might have side-effects) to be in a separate
 165    basic block because the program counter will always be at the same
 166    location after the COND_EXEC instruction, regardless of whether the
 167    condition is true or not.
 168
 169    Basic blocks need not start with a label nor end with a jump insn.
 170    For example, a previous basic block may just "conditionally fall"
 171    into the succeeding basic block, and the last basic block need not
 172    end with a jump insn.  Block 0 is a descendant of the entry block.
 173
 174    A basic block beginning with two labels cannot have notes between
 175    the labels.
 176
 177    Data for jump tables are stored in jump_insns that occur in no
 178    basic block even though these insns can follow or precede insns in
 179    basic blocks.  */
 180
 181 /* Basic block information indexed by block number.  */
 182 typedef struct basic_block_def {
 183   /* The first and last insns of the block.  */
 184   rtx head, end;
 185
 186   /* The first and last trees of the block.  */
 187   tree head_tree;
 188   tree end_tree;
 189
 190   /* The edges into and out of the block.  */
 191   edge pred, succ;
 192
 193   /* Liveness info.  */
 194
 195   /* The registers that are modified within this in block.  */
 196   regset local_set;
 197   /* The registers that are conditionally modified within this block.
 198      In other words, registers that are set only as part of a
 199      COND_EXEC.  */
 200   regset cond_local_set;
 201   /* The registers that are live on entry to this block.
 202
 203      Note that in SSA form, global_live_at_start does not reflect the
 204      use of regs in phi functions, since the liveness of these regs
 205      may depend on which edge was taken into the block.  */
 206   regset global_live_at_start;
 207   /* The registers that are live on exit from this block.  */
 208   regset global_live_at_end;
 209
 210   /* Auxiliary info specific to a pass.  */
 211   void *aux;
 212
 213   /* The index of this block.  */
 214   int index;
 215
 216   /* Previous and next blocks in the chain.  */
 217   struct basic_block_def *prev_bb, *next_bb;
 218
 219   /* The loop depth of this block.  */
 220   int loop_depth;
 221
 222   /* Outermost loop containing the block.  */
 223   struct loop *loop_father;
 224
 225   /* Expected number of executions: calculated in profile.c.  */
 226   gcov_type count;
 227
 228   /* Expected frequency.  Normalized to be in range 0 to BB_FREQ_MAX.  */
 229   int frequency;
 230
 231   /* Various flags.  See BB_* below.  */
 232   int flags;
 233 } *basic_block;
 234
 235 #define BB_FREQ_MAX 10000
 236
 237 /* Masks for basic_block.flags.  */
 238 #define BB_DIRTY                1
 239 #define BB_NEW                  2
 240 #define BB_REACHABLE            4
 241 #define BB_VISITED              8
 242
 243 /* Number of basic blocks in the current function.  */
 244
 245 extern int n_basic_blocks;
 246
 247 /* First free basic block number.  */
 248
 249 extern int last_basic_block;
 250
 251 /* Number of edges in the current function.  */
 252
 253 extern int n_edges;
 254
 255 /* Index by basic block number, get basic block struct info.  */
 256
 257 extern varray_type basic_block_info;
 258
 259 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 260
 261 /* For iterating over basic blocks.  */
 262 #define FOR_BB_BETWEEN(BB, FROM, TO, DIR) \
 263   for (BB = FROM; BB != TO; BB = BB->DIR)
 264
 265 #define FOR_EACH_BB(BB) \
 266   FOR_BB_BETWEEN (BB, ENTRY_BLOCK_PTR->next_bb, EXIT_BLOCK_PTR, next_bb)
 267
 268 #define FOR_EACH_BB_REVERSE(BB) \
 269   FOR_BB_BETWEEN (BB, EXIT_BLOCK_PTR->prev_bb, ENTRY_BLOCK_PTR, prev_bb)
 270
 271 /* Cycles through _all_ basic blocks, even the fake ones (entry and
 272    exit block).  */
 273
 274 #define FOR_ALL_BB(BB) \
 275   for (BB = ENTRY_BLOCK_PTR; BB; BB = BB->next_bb)
 276
 277 /* What registers are live at the setjmp call.  */
 278
 279 extern regset regs_live_at_setjmp;
 280
 281 /* Special labels found during CFG build.  */
 282
 283 extern GTY(()) rtx label_value_list;
 284 extern GTY(()) rtx tail_recursion_label_list;
 285
 286 extern struct obstack flow_obstack;
 287
 288 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 289    If the value is REG_BLOCK_GLOBAL (-2),
 290    it means (REG n) is used in more than one basic block.
 291    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 292    This information remains valid for the rest of the compilation
 293    of the current function; it is used to control register allocation.  */
 294
 295 #define REG_BLOCK_UNKNOWN -1
 296 #define REG_BLOCK_GLOBAL -2
 297
 298 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 299 \f
 300 /* Stuff for recording basic block info.  */
 301
 302 #define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
 303 #define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
 304
 305 #define BLOCK_HEAD_TREE(B) (BASIC_BLOCK (B)->head_tree)
 306 #define BLOCK_END_TREE(B) (BASIC_BLOCK (B)->end_tree)
 307
 308 /* Special block numbers [markers] for entry and exit.  */
 309 #define ENTRY_BLOCK (-1)
 310 #define EXIT_BLOCK (-2)
 311
 312 /* Special block number not valid for any block.  */
 313 #define INVALID_BLOCK (-3)
 314
 315 /* Similarly, block pointers for the edge list.  */
 316 extern struct basic_block_def entry_exit_blocks[2];
 317 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
 318 #define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])
 319
 320 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 321 #define set_block_for_insn(INSN, BB)  (BLOCK_FOR_INSN (INSN) = BB)
 322
 323 extern void compute_bb_for_insn         PARAMS ((void));
 324 extern void free_bb_for_insn            PARAMS ((void));
 325 extern void update_bb_for_insn          PARAMS ((basic_block));
 326
 327 extern void free_basic_block_vars       PARAMS ((int));
 328
 329 extern edge split_block                 PARAMS ((basic_block, rtx));
 330 extern basic_block split_edge           PARAMS ((edge));
 331 extern void insert_insn_on_edge         PARAMS ((rtx, edge));
 332
 333 extern void commit_edge_insertions      PARAMS ((void));
 334 extern void commit_edge_insertions_watch_calls  PARAMS ((void));
 335
 336 extern void remove_fake_edges           PARAMS ((void));
 337 extern void add_noreturn_fake_exit_edges        PARAMS ((void));
 338 extern void connect_infinite_loops_to_exit      PARAMS ((void));
 339 extern int flow_call_edges_add          PARAMS ((sbitmap));
 340 extern edge cached_make_edge            PARAMS ((sbitmap *, basic_block,
 341                                                  basic_block, int));
 342 extern edge make_edge                   PARAMS ((basic_block,
 343                                                  basic_block, int));
 344 extern edge make_single_succ_edge       PARAMS ((basic_block,
 345                                                  basic_block, int));
 346 extern void remove_edge                 PARAMS ((edge));
 347 extern void redirect_edge_succ          PARAMS ((edge, basic_block));
 348 extern edge redirect_edge_succ_nodup    PARAMS ((edge, basic_block));
 349 extern void redirect_edge_pred          PARAMS ((edge, basic_block));
 350 extern basic_block create_basic_block_structure PARAMS ((rtx, rtx, rtx, basic_block));
 351 extern basic_block create_basic_block   PARAMS ((rtx, rtx, basic_block));
 352 extern int flow_delete_block            PARAMS ((basic_block));
 353 extern int flow_delete_block_noexpunge  PARAMS ((basic_block));
 354 extern void clear_bb_flags              PARAMS ((void));
 355 extern void merge_blocks_nomove         PARAMS ((basic_block, basic_block));
 356 extern void tidy_fallthru_edge          PARAMS ((edge, basic_block,
 357                                                  basic_block));
 358 extern void tidy_fallthru_edges         PARAMS ((void));
 359 extern void flow_reverse_top_sort_order_compute PARAMS ((int *));
 360 extern int flow_depth_first_order_compute       PARAMS ((int *, int *));
 361 extern void flow_preorder_transversal_compute   PARAMS ((int *));
 362 extern void dump_edge_info              PARAMS ((FILE *, edge, int));
 363 extern void clear_edges                 PARAMS ((void));
 364 extern void mark_critical_edges         PARAMS ((void));
 365 extern rtx first_insn_after_basic_block_note    PARAMS ((basic_block));
 366
 367 /* Dominator information for basic blocks.  */
 368
 369 typedef struct dominance_info *dominance_info;
 370
 371 /* Structure to hold information for each natural loop.  */
 372 struct loop
 373 {
 374   /* Index into loops array.  */
 375   int num;
 376
 377   /* Basic block of loop header.  */
 378   basic_block header;
 379
 380   /* Basic block of loop latch.  */
 381   basic_block latch;
 382
 383   /* Basic block of loop pre-header or NULL if it does not exist.  */
 384   basic_block pre_header;
 385
 386   /* Array of edges along the pre-header extended basic block trace.
 387      The source of the first edge is the root node of pre-header
 388      extended basic block, if it exists.  */
 389   edge *pre_header_edges;
 390
 391   /* Number of edges along the pre_header extended basic block trace.  */
 392   int num_pre_header_edges;
 393
 394   /* The first block in the loop.  This is not necessarily the same as
 395      the loop header.  */
 396   basic_block first;
 397
 398   /* The last block in the loop.  This is not necessarily the same as
 399      the loop latch.  */
 400   basic_block last;
 401
 402   /* Bitmap of blocks contained within the loop.  */
 403   sbitmap nodes;
 404
 405   /* Number of blocks contained within the loop.  */
 406   int num_nodes;
 407
 408   /* Array of edges that enter the loop.  */
 409   edge *entry_edges;
 410
 411   /* Number of edges that enter the loop.  */
 412   int num_entries;
 413
 414   /* Array of edges that exit the loop.  */
 415   edge *exit_edges;
 416
 417   /* Number of edges that exit the loop.  */
 418   int num_exits;
 419
 420   /* Bitmap of blocks that dominate all exits of the loop.  */
 421   sbitmap exits_doms;
 422
 423   /* The loop nesting depth.  */
 424   int depth;
 425
 426   /* Superloops of the loop.  */
 427   struct loop **pred;
 428
 429   /* The height of the loop (enclosed loop levels) within the loop
 430      hierarchy tree.  */
 431   int level;
 432
 433   /* The outer (parent) loop or NULL if outermost loop.  */
 434   struct loop *outer;
 435
 436   /* The first inner (child) loop or NULL if innermost loop.  */
 437   struct loop *inner;
 438
 439   /* Link to the next (sibling) loop.  */
 440   struct loop *next;
 441
 442   /* Nonzero if the loop is invalid (e.g., contains setjmp.).  */
 443   int invalid;
 444
 445   /* Auxiliary info specific to a pass.  */
 446   void *aux;
 447
 448   /* The following are currently used by loop.c but they are likely to
 449      disappear as loop.c is converted to use the CFG.  */
 450
 451   /* Nonzero if the loop has a NOTE_INSN_LOOP_VTOP.  */
 452   rtx vtop;
 453
 454   /* Nonzero if the loop has a NOTE_INSN_LOOP_CONT.
 455      A continue statement will generate a branch to NEXT_INSN (cont).  */
 456   rtx cont;
 457
 458   /* The NOTE_INSN_LOOP_BEG.  */
 459   rtx start;
 460
 461   /* The NOTE_INSN_LOOP_END.  */
 462   rtx end;
 463
 464   /* For a rotated loop that is entered near the bottom,
 465      this is the label at the top.  Otherwise it is zero.  */
 466   rtx top;
 467
 468   /* Place in the loop where control enters.  */
 469   rtx scan_start;
 470
 471   /* The position where to sink insns out of the loop.  */
 472   rtx sink;
 473
 474   /* List of all LABEL_REFs which refer to code labels outside the
 475      loop.  Used by routines that need to know all loop exits, such as
 476      final_biv_value and final_giv_value.
 477
 478      This does not include loop exits due to return instructions.
 479      This is because all bivs and givs are pseudos, and hence must be
 480      dead after a return, so the presense of a return does not affect
 481      any of the optimizations that use this info.  It is simpler to
 482      just not include return instructions on this list.  */
 483   rtx exit_labels;
 484
 485   /* The number of LABEL_REFs on exit_labels for this loop and all
 486      loops nested inside it.  */
 487   int exit_count;
 488 };
 489
 490
 491 /* Structure to hold CFG information about natural loops within a function.  */
 492 struct loops
 493 {
 494   /* Number of natural loops in the function.  */
 495   int num;
 496
 497   /* Maxium nested loop level in the function.  */
 498   int levels;
 499
 500   /* Array of natural loop descriptors (scanning this array in reverse order
 501      will find the inner loops before their enclosing outer loops).  */
 502   struct loop *array;
 503
 504   /* The above array is unused in new loop infrastructure and is kept only for
 505      purposes of the old loop optimizer.  Instead we store just pointers to
 506      loops here.  */
 507   struct loop **parray;
 508
 509   /* Pointer to root of loop heirachy tree.  */
 510   struct loop *tree_root;
 511
 512   /* Information derived from the CFG.  */
 513   struct cfg
 514   {
 515     /* The bitmap vector of dominators or NULL if not computed.  */
 516     dominance_info dom;
 517
 518     /* The ordering of the basic blocks in a depth first search.  */
 519     int *dfs_order;
 520
 521     /* The reverse completion ordering of the basic blocks found in a
 522        depth first search.  */
 523     int *rc_order;
 524   } cfg;
 525
 526   /* Headers shared by multiple loops that should be merged.  */
 527   sbitmap shared_headers;
 528 };
 529
 530 /* Structure to group all of the information to process IF-THEN and
 531    IF-THEN-ELSE blocks for the conditional execution support.  This
 532    needs to be in a public file in case the IFCVT macros call
 533    functions passing the ce_if_block data structure.  */
 534
 535 typedef struct ce_if_block
 536 {
 537   basic_block test_bb;                  /* First test block.  */
 538   basic_block then_bb;                  /* THEN block.  */
 539   basic_block else_bb;                  /* ELSE block or NULL.  */
 540   basic_block join_bb;                  /* Join THEN/ELSE blocks.  */
 541   basic_block last_test_bb;             /* Last bb to hold && or || tests.  */
 542   int num_multiple_test_blocks;         /* # of && and || basic blocks.  */
 543   int num_and_and_blocks;               /* # of && blocks.  */
 544   int num_or_or_blocks;                 /* # of || blocks.  */
 545   int num_multiple_test_insns;          /* # of insns in && and || blocks.  */
 546   int and_and_p;                        /* Complex test is &&.  */
 547   int num_then_insns;                   /* # of insns in THEN block.  */
 548   int num_else_insns;                   /* # of insns in ELSE block.  */
 549   int pass;                             /* Pass number.  */
 550
 551 #ifdef IFCVT_EXTRA_FIELDS
 552   IFCVT_EXTRA_FIELDS                    /* Any machine dependent fields.  */
 553 #endif
 554
 555 } ce_if_block_t;
 556
 557 extern int flow_loops_find PARAMS ((struct loops *, int flags));
 558 extern int flow_loops_update PARAMS ((struct loops *, int flags));
 559 extern void flow_loops_free PARAMS ((struct loops *));
 560 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *,
 561                                      void (*)(const struct loop *,
 562                                               FILE *, int), int));
 563 extern void flow_loop_dump PARAMS ((const struct loop *, FILE *,
 564                                     void (*)(const struct loop *,
 565                                              FILE *, int), int));
 566 extern int flow_loop_scan PARAMS ((struct loops *, struct loop *, int));
 567 extern void flow_loop_tree_node_add PARAMS ((struct loop *, struct loop *));
 568 extern void flow_loop_tree_node_remove PARAMS ((struct loop *));
 569
 570 /* This structure maintains an edge list vector.  */
 571 struct edge_list
 572 {
 573   int num_blocks;
 574   int num_edges;
 575   edge *index_to_edge;
 576 };
 577
 578 /* This is the value which indicates no edge is present.  */
 579 #define EDGE_INDEX_NO_EDGE      -1
 580
 581 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 582    if there is no edge between the 2 basic blocks.  */
 583 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 584
 585 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 586    block which is either the pred or succ end of the indexed edge.  */
 587 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 588 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 589
 590 /* INDEX_EDGE returns a pointer to the edge.  */
 591 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 592
 593 /* Number of edges in the compressed edge list.  */
 594 #define NUM_EDGES(el)                   ((el)->num_edges)
 595
 596 /* BB is assumed to contain conditional jump.  Return the fallthru edge.  */
 597 #define FALLTHRU_EDGE(bb)               ((bb)->succ->flags & EDGE_FALLTHRU \
 598                                          ? (bb)->succ : (bb)->succ->succ_next)
 599
 600 /* BB is assumed to contain conditional jump.  Return the branch edge.  */
 601 #define BRANCH_EDGE(bb)                 ((bb)->succ->flags & EDGE_FALLTHRU \
 602                                          ? (bb)->succ->succ_next : (bb)->succ)
 603
 604 /* Return expected execution frequency of the edge E.  */
 605 #define EDGE_FREQUENCY(e)               (((e)->src->frequency \
 606                                           * (e)->probability \
 607                                           + REG_BR_PROB_BASE / 2) \
 608                                          / REG_BR_PROB_BASE)
 609
 610 /* Return nonzero if edge is critical.  */
 611 #define EDGE_CRITICAL_P(e)              ((e)->src->succ->succ_next \
 612                                          && (e)->dest->pred->pred_next)
 613
 614 struct edge_list * create_edge_list     PARAMS ((void));
 615 void free_edge_list                     PARAMS ((struct edge_list *));
 616 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 617 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 618 int find_edge_index                     PARAMS ((struct edge_list *,
 619                                                  basic_block, basic_block));
 620
 621
 622 enum update_life_extent
 623 {
 624   UPDATE_LIFE_LOCAL = 0,
 625   UPDATE_LIFE_GLOBAL = 1,
 626   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 627 };
 628
 629 /* Flags for life_analysis and update_life_info.  */
 630
 631 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 632 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 633 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 634 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 635 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 636 #define PROP_ALLOW_CFG_CHANGES  32      /* Allow the CFG to be changed
 637                                            by dead code removal.  */
 638 #define PROP_AUTOINC            64      /* Create autoinc mem references.  */
 639 #define PROP_EQUAL_NOTES        128     /* Take into account REG_EQUAL notes.  */
 640 #define PROP_SCAN_DEAD_STORES   256     /* Scan for dead code.  */
 641 #define PROP_FINAL              (PROP_DEATH_NOTES | PROP_LOG_LINKS  \
 642                                  | PROP_REG_INFO | PROP_KILL_DEAD_CODE  \
 643                                  | PROP_SCAN_DEAD_CODE | PROP_AUTOINC \
 644                                  | PROP_ALLOW_CFG_CHANGES \
 645                                  | PROP_SCAN_DEAD_STORES)
 646
 647 #define CLEANUP_EXPENSIVE       1       /* Do relativly expensive optimizations
 648                                            except for edge forwarding */
 649 #define CLEANUP_CROSSJUMP       2       /* Do crossjumping.  */
 650 #define CLEANUP_POST_REGSTACK   4       /* We run after reg-stack and need
 651                                            to care REG_DEAD notes.  */
 652 #define CLEANUP_PRE_SIBCALL     8       /* Do not get confused by code hidden
 653                                            inside call_placeholders..  */
 654 #define CLEANUP_PRE_LOOP        16      /* Take care to preserve syntactic loop
 655                                            notes.  */
 656 #define CLEANUP_UPDATE_LIFE     32      /* Keep life information up to date.  */
 657 #define CLEANUP_THREADING       64      /* Do jump threading.  */
 658 #define CLEANUP_NO_INSN_DEL     128     /* Do not try to delete trivially dead
 659                                            insns.  */
 660 /* Flags for loop discovery.  */
 661
 662 #define LOOP_TREE               1       /* Build loop hierarchy tree.  */
 663 #define LOOP_PRE_HEADER         2       /* Analyse loop pre-header.  */
 664 #define LOOP_ENTRY_EDGES        4       /* Find entry edges.  */
 665 #define LOOP_EXIT_EDGES         8       /* Find exit edges.  */
 666 #define LOOP_EDGES              (LOOP_ENTRY_EDGES | LOOP_EXIT_EDGES)
 667 #define LOOP_ALL               15       /* All of the above  */
 668
 669 extern void life_analysis       PARAMS ((rtx, FILE *, int));
 670 extern int update_life_info     PARAMS ((sbitmap, enum update_life_extent,
 671                                          int));
 672 extern int update_life_info_in_dirty_blocks PARAMS ((enum update_life_extent,
 673                                                       int));
 674 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 675 extern int propagate_block      PARAMS ((basic_block, regset, regset, regset,
 676                                          int));
 677
 678 struct propagate_block_info;
 679 extern rtx propagate_one_insn   PARAMS ((struct propagate_block_info *, rtx));
 680 extern struct propagate_block_info *init_propagate_block_info
 681   PARAMS ((basic_block, regset, regset, regset, int));
 682 extern void free_propagate_block_info PARAMS ((struct propagate_block_info *));
 683
 684 /* In lcm.c */
 685 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 686                                                  sbitmap *, sbitmap *,
 687                                                  sbitmap *, sbitmap **,
 688                                                  sbitmap **));
 689 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 690                                                    sbitmap *, sbitmap *,
 691                                                    sbitmap *, sbitmap **,
 692                                                    sbitmap **));
 693 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 694                                                  sbitmap *, sbitmap *));
 695 extern int optimize_mode_switching      PARAMS ((FILE *));
 696
 697 /* In emit-rtl.c.  */
 698 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 699 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 700
 701 /* In predict.c */
 702 extern void estimate_probability        PARAMS ((struct loops *));
 703 extern void note_prediction_to_br_prob  PARAMS ((void));
 704 extern void expected_value_to_br_prob   PARAMS ((void));
 705 extern void note_prediction_to_br_prob  PARAMS ((void));
 706 extern bool maybe_hot_bb_p              PARAMS ((basic_block));
 707 extern bool probably_cold_bb_p          PARAMS ((basic_block));
 708 extern bool probably_never_executed_bb_p PARAMS ((basic_block));
 709
 710 /* In flow.c */
 711 extern void init_flow                   PARAMS ((void));
 712 extern void reorder_basic_blocks        PARAMS ((void));
 713 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 714 extern void debug_bb                    PARAMS ((basic_block));
 715 extern void debug_bb_n                  PARAMS ((int));
 716 extern void dump_regset                 PARAMS ((regset, FILE *));
 717 extern void debug_regset                PARAMS ((regset));
 718 extern void allocate_reg_life_data      PARAMS ((void));
 719 extern void allocate_bb_life_data       PARAMS ((void));
 720 extern void expunge_block               PARAMS ((basic_block));
 721 extern void link_block                  PARAMS ((basic_block, basic_block));
 722 extern void unlink_block                PARAMS ((basic_block));
 723 extern void compact_blocks              PARAMS ((void));
 724 extern basic_block alloc_block          PARAMS ((void));
 725 extern void find_unreachable_blocks     PARAMS ((void));
 726 extern int delete_noop_moves            PARAMS ((rtx));
 727 extern basic_block redirect_edge_and_branch_force PARAMS ((edge, basic_block));
 728 extern basic_block force_nonfallthru    PARAMS ((edge));
 729 extern bool redirect_edge_and_branch    PARAMS ((edge, basic_block));
 730 extern rtx block_label                  PARAMS ((basic_block));
 731 extern bool forwarder_block_p           PARAMS ((basic_block));
 732 extern bool purge_all_dead_edges        PARAMS ((int));
 733 extern bool purge_dead_edges            PARAMS ((basic_block));
 734 extern void find_sub_basic_blocks       PARAMS ((basic_block));
 735 extern void find_many_sub_basic_blocks  PARAMS ((sbitmap));
 736 extern bool can_fallthru                PARAMS ((basic_block, basic_block));
 737 extern void flow_nodes_print            PARAMS ((const char *, const sbitmap,
 738                                                  FILE *));
 739 extern void flow_edge_list_print        PARAMS ((const char *, const edge *,
 740                                                  int, FILE *));
 741 extern void alloc_aux_for_block         PARAMS ((basic_block, int));
 742 extern void alloc_aux_for_blocks        PARAMS ((int));
 743 extern void clear_aux_for_blocks        PARAMS ((void));
 744 extern void free_aux_for_blocks         PARAMS ((void));
 745 extern void alloc_aux_for_edge          PARAMS ((edge, int));
 746 extern void alloc_aux_for_edges         PARAMS ((int));
 747 extern void clear_aux_for_edges         PARAMS ((void));
 748 extern void free_aux_for_edges          PARAMS ((void));
 749
 750 /* This function is always defined so it can be called from the
 751    debugger, and it is declared extern so we don't get warnings about
 752    it being unused.  */
 753 extern void verify_flow_info            PARAMS ((void));
 754 extern bool flow_loop_outside_edge_p    PARAMS ((const struct loop *, edge));
 755 extern bool flow_loop_nested_p PARAMS ((const struct loop *,
 756                                         const struct loop *));
 757 extern bool flow_bb_inside_loop_p       PARAMS ((const struct loop *,
 758                                                  const basic_block));
 759 extern basic_block *get_loop_body       PARAMS ((const struct loop *));
 760 extern int dfs_enumerate_from           PARAMS ((basic_block, int,
 761                                          bool (*)(basic_block, void *),
 762                                          basic_block *, int, void *));
 763
 764 extern edge loop_preheader_edge PARAMS ((struct loop *));
 765 extern edge loop_latch_edge PARAMS ((struct loop *));
 766
 767 extern void add_bb_to_loop PARAMS ((basic_block, struct loop *));
 768 extern void remove_bb_from_loops PARAMS ((basic_block));
 769 extern struct loop * find_common_loop PARAMS ((struct loop *, struct loop *));
 770
 771 extern void verify_loop_structure PARAMS ((struct loops *, int));
 772 #define VLS_EXPECT_PREHEADERS 1
 773 #define VLS_EXPECT_SIMPLE_LATCHES 2
 774
 775 typedef struct conflict_graph_def *conflict_graph;
 776
 777 /* Callback function when enumerating conflicts.  The arguments are
 778    the smaller and larger regno in the conflict.  Returns zero if
 779    enumeration is to continue, nonzero to halt enumeration.  */
 780 typedef int (*conflict_graph_enum_fn) PARAMS ((int, int, void *));
 781
 782
 783 /* Prototypes of operations on conflict graphs.  */
 784
 785 extern conflict_graph conflict_graph_new
 786                                         PARAMS ((int));
 787 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 788 extern int conflict_graph_add           PARAMS ((conflict_graph,
 789                                                  int, int));
 790 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 791                                                  int, int));
 792 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 793                                                  conflict_graph_enum_fn,
 794                                                  void *));
 795 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 796                                                  int));
 797 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 798 extern conflict_graph conflict_graph_compute
 799                                         PARAMS ((regset,
 800                                                  partition));
 801 extern bool mark_dfs_back_edges         PARAMS ((void));
 802 extern void set_edge_can_fallthru_flag  PARAMS ((void));
 803 extern void update_br_prob_note         PARAMS ((basic_block));
 804 extern void fixup_abnormal_edges        PARAMS ((void));
 805 extern bool can_hoist_insn_p            PARAMS ((rtx, rtx, regset));
 806 extern rtx hoist_insn_after             PARAMS ((rtx, rtx, rtx, rtx));
 807 extern rtx hoist_insn_to_edge           PARAMS ((rtx, edge, rtx, rtx));
 808
 809 /* In dominance.c */
 810
 811 enum cdi_direction
 812 {
 813   CDI_DOMINATORS,
 814   CDI_POST_DOMINATORS
 815 };
 816
 817 extern dominance_info calculate_dominance_info  PARAMS ((enum cdi_direction));
 818 extern void free_dominance_info                 PARAMS ((dominance_info));
 819 extern basic_block nearest_common_dominator     PARAMS ((dominance_info,
 820                                                  basic_block, basic_block));
 821 extern void set_immediate_dominator     PARAMS ((dominance_info,
 822                                                  basic_block, basic_block));
 823 extern basic_block get_immediate_dominator      PARAMS ((dominance_info,
 824                                                  basic_block));
 825 extern bool dominated_by_p      PARAMS ((dominance_info, basic_block, basic_block));
 826 extern int get_dominated_by PARAMS ((dominance_info, basic_block, basic_block **));
 827 extern void add_to_dominance_info PARAMS ((dominance_info, basic_block));
 828 extern void delete_from_dominance_info PARAMS ((dominance_info, basic_block));
 829 basic_block recount_dominator PARAMS ((dominance_info, basic_block));
 830 extern void redirect_immediate_dominators PARAMS ((dominance_info, basic_block,
 831                                                  basic_block));
 832 void iterate_fix_dominators PARAMS ((dominance_info, basic_block *, int));
 833 extern void verify_dominators PARAMS ((dominance_info));
 834 #endif /* GCC_BASIC_BLOCK_H */