gcc/basic-block.h

   1 /* Define control and data flow tables, and regsets.
   2    Copyright (C) 1987, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 #ifndef _BASIC_BLOCK_H
  22 #define _BASIC_BLOCK_H 1
  23
  24 #include "bitmap.h"
  25 #include "sbitmap.h"
  26 #include "varray.h"
  27 #include "partition.h"
  28
  29 /* Head of register set linked list.  */
  30 typedef bitmap_head regset_head;
  31 /* A pointer to a regset_head.  */
  32 typedef bitmap regset;
  33
  34 /* Initialize a new regset.  */
  35 #define INIT_REG_SET(HEAD) bitmap_initialize (HEAD)
  36
  37 /* Clear a register set by freeing up the linked list.  */
  38 #define CLEAR_REG_SET(HEAD) bitmap_clear (HEAD)
  39
  40 /* Copy a register set to another register set.  */
  41 #define COPY_REG_SET(TO, FROM) bitmap_copy (TO, FROM)
  42
  43 /* Compare two register sets.  */
  44 #define REG_SET_EQUAL_P(A, B) bitmap_equal_p (A, B)
  45
  46 /* `and' a register set with a second register set.  */
  47 #define AND_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_AND)
  48
  49 /* `and' the complement of a register set with a register set.  */
  50 #define AND_COMPL_REG_SET(TO, FROM) \
  51   bitmap_operation (TO, TO, FROM, BITMAP_AND_COMPL)
  52
  53 /* Inclusive or a register set with a second register set.  */
  54 #define IOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_IOR)
  55
  56 /* Exclusive or a register set with a second register set.  */
  57 #define XOR_REG_SET(TO, FROM) bitmap_operation (TO, TO, FROM, BITMAP_XOR)
  58
  59 /* Or into TO the register set FROM1 `and'ed with the complement of FROM2.  */
  60 #define IOR_AND_COMPL_REG_SET(TO, FROM1, FROM2) \
  61   bitmap_ior_and_compl (TO, FROM1, FROM2)
  62
  63 /* Clear a single register in a register set.  */
  64 #define CLEAR_REGNO_REG_SET(HEAD, REG) bitmap_clear_bit (HEAD, REG)
  65
  66 /* Set a single register in a register set.  */
  67 #define SET_REGNO_REG_SET(HEAD, REG) bitmap_set_bit (HEAD, REG)
  68
  69 /* Return true if a register is set in a register set.  */
  70 #define REGNO_REG_SET_P(TO, REG) bitmap_bit_p (TO, REG)
  71
  72 /* Copy the hard registers in a register set to the hard register set.  */
  73 #define REG_SET_TO_HARD_REG_SET(TO, FROM)                               \
  74 do {                                                                    \
  75   int i_;                                                               \
  76   CLEAR_HARD_REG_SET (TO);                                              \
  77   for (i_ = 0; i_ < FIRST_PSEUDO_REGISTER; i_++)                        \
  78     if (REGNO_REG_SET_P (FROM, i_))                                     \
  79       SET_HARD_REG_BIT (TO, i_);                                        \
  80 } while (0)
  81
  82 /* Loop over all registers in REGSET, starting with MIN, setting REGNUM to the
  83    register number and executing CODE for all registers that are set. */
  84 #define EXECUTE_IF_SET_IN_REG_SET(REGSET, MIN, REGNUM, CODE)            \
  85   EXECUTE_IF_SET_IN_BITMAP (REGSET, MIN, REGNUM, CODE)
  86
  87 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  88    REGNUM to the register number and executing CODE for all registers that are
  89    set in the first regset and not set in the second. */
  90 #define EXECUTE_IF_AND_COMPL_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  91   EXECUTE_IF_AND_COMPL_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  92
  93 /* Loop over all registers in REGSET1 and REGSET2, starting with MIN, setting
  94    REGNUM to the register number and executing CODE for all registers that are
  95    set in both regsets. */
  96 #define EXECUTE_IF_AND_IN_REG_SET(REGSET1, REGSET2, MIN, REGNUM, CODE) \
  97   EXECUTE_IF_AND_IN_BITMAP (REGSET1, REGSET2, MIN, REGNUM, CODE)
  98
  99 /* Allocate a register set with oballoc.  */
 100 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
 101
 102 /* Initialize a register set.  Returns the new register set.  */
 103 #define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD)
 104
 105 /* Do any cleanup needed on a regset when it is no longer used.  */
 106 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
 107
 108 /* Do any one-time initializations needed for regsets.  */
 109 #define INIT_ONCE_REG_SET() BITMAP_INIT_ONCE ()
 110
 111 /* Grow any tables needed when the number of registers is calculated
 112    or extended.  For the linked list allocation, nothing needs to
 113    be done, other than zero the statistics on the first allocation.  */
 114 #define MAX_REGNO_REG_SET(NUM_REGS, NEW_P, RENUMBER_P)
 115
 116 /* Control flow edge information.  */
 117 typedef struct edge_def {
 118   /* Links through the predecessor and successor lists.  */
 119   struct edge_def *pred_next, *succ_next;
 120
 121   /* The two blocks at the ends of the edge.  */
 122   struct basic_block_def *src, *dest;
 123
 124   /* Instructions queued on the edge.  */
 125   rtx insns;
 126
 127   /* Auxiliary info specific to a pass.  */
 128   void *aux;
 129
 130   int flags;                    /* see EDGE_* below  */
 131   int probability;              /* biased by REG_BR_PROB_BASE */
 132 } *edge;
 133
 134 #define EDGE_FALLTHRU           1
 135 #define EDGE_CRITICAL           2
 136 #define EDGE_ABNORMAL           4
 137 #define EDGE_ABNORMAL_CALL      8
 138 #define EDGE_EH                 16
 139 #define EDGE_FAKE               32
 140
 141
 142 /* Basic block information indexed by block number.  */
 143 typedef struct basic_block_def {
 144   /* The first and last insns of the block.  */
 145   rtx head, end;
 146
 147   /* The edges into and out of the block.  */
 148   edge pred, succ;
 149
 150   /* Liveness info.  Note that in SSA form, global_live_at_start does
 151      not reflect the use of regs in phi functions, since the liveness
 152      of these regs may depend on which edge was taken into the block.  */
 153   regset local_set;
 154   regset global_live_at_start;
 155   regset global_live_at_end;
 156
 157   /* Auxiliary info specific to a pass.  */
 158   void *aux;
 159
 160   /* The index of this block.  */
 161   int index;
 162   /* The loop depth of this block plus one.  */
 163   int loop_depth;
 164
 165   /* The active eh region before head and after end.  */
 166   int eh_beg, eh_end;
 167 } *basic_block;
 168
 169 /* Number of basic blocks in the current function.  */
 170
 171 extern int n_basic_blocks;
 172
 173 /* Number of edges in the current function.  */
 174
 175 extern int n_edges;
 176
 177 /* Index by basic block number, get basic block struct info.  */
 178
 179 extern varray_type basic_block_info;
 180
 181 #define BASIC_BLOCK(N)  (VARRAY_BB (basic_block_info, (N)))
 182
 183 /* What registers are live at the setjmp call.  */
 184
 185 extern regset regs_live_at_setjmp;
 186
 187 /* Indexed by n, gives number of basic block that  (REG n) is used in.
 188    If the value is REG_BLOCK_GLOBAL (-2),
 189    it means (REG n) is used in more than one basic block.
 190    REG_BLOCK_UNKNOWN (-1) means it hasn't been seen yet so we don't know.
 191    This information remains valid for the rest of the compilation
 192    of the current function; it is used to control register allocation.  */
 193
 194 #define REG_BLOCK_UNKNOWN -1
 195 #define REG_BLOCK_GLOBAL -2
 196
 197 #define REG_BASIC_BLOCK(N) (VARRAY_REG (reg_n_info, N)->basic_block)
 198 \f
 199 /* Stuff for recording basic block info.  */
 200
 201 #define BLOCK_HEAD(B)      (BASIC_BLOCK (B)->head)
 202 #define BLOCK_END(B)       (BASIC_BLOCK (B)->end)
 203
 204 /* Special block numbers [markers] for entry and exit.  */
 205 #define ENTRY_BLOCK (-1)
 206 #define EXIT_BLOCK (-2)
 207
 208 /* Similarly, block pointers for the edge list.  */
 209 extern struct basic_block_def entry_exit_blocks[2];
 210 #define ENTRY_BLOCK_PTR (&entry_exit_blocks[0])
 211 #define EXIT_BLOCK_PTR  (&entry_exit_blocks[1])
 212
 213 extern varray_type basic_block_for_insn;
 214 #define BLOCK_FOR_INSN(INSN)  VARRAY_BB (basic_block_for_insn, INSN_UID (INSN))
 215 #define BLOCK_NUM(INSN)       (BLOCK_FOR_INSN (INSN)->index + 0)
 216
 217 extern void compute_bb_for_insn         PARAMS ((int));
 218 extern void set_block_for_insn          PARAMS ((rtx, basic_block));
 219 extern void set_block_num               PARAMS ((rtx, int));
 220
 221 extern void free_basic_block_vars       PARAMS ((int));
 222
 223 extern basic_block split_edge           PARAMS ((edge));
 224 extern void insert_insn_on_edge         PARAMS ((rtx, edge));
 225 extern void commit_edge_insertions      PARAMS ((void));
 226 extern void remove_fake_edges           PARAMS ((void));
 227 extern void add_noreturn_fake_exit_edges        PARAMS ((void));
 228 extern rtx flow_delete_insn             PARAMS ((rtx));
 229 extern void flow_delete_insn_chain      PARAMS ((rtx, rtx));
 230 extern void make_edge                   PARAMS ((sbitmap *, basic_block,
 231                                                  basic_block, int));
 232 extern void remove_edge                 PARAMS ((edge));
 233 extern void create_basic_block          PARAMS ((int, rtx, rtx, rtx));
 234
 235
 236 /* Structure to hold information for each natural loop.  */
 237 struct loop
 238 {
 239   int num;
 240
 241   /* Basic block of loop header.  */
 242   basic_block header;
 243
 244   /* Basic block of loop latch.  */
 245   basic_block latch;
 246
 247   /* Basic block of loop pre-header or NULL if it does not exist.  */
 248   basic_block pre_header;
 249
 250   /* The first block in the loop.  This is not necessarily the same as
 251      the loop header.  */
 252   basic_block first;
 253
 254   /* The last block in the loop.  This is not necessarily the same as
 255      the loop latch.  */
 256   basic_block last;
 257
 258   /* Bitmap of blocks contained within the loop.  */
 259   sbitmap nodes;
 260
 261   /* Number of blocks contained within the loop.  */
 262   int num_nodes;
 263
 264   /* Array of edges that exit the loop.  */
 265   edge *exits;
 266
 267   /* Number of edges that exit the loop.  */
 268   int num_exits;
 269
 270   /* The loop nesting depth.  */
 271   int depth;
 272
 273   /* The height of the loop (enclosed loop levels) within the loop
 274      hierarchy tree.  */
 275   int level;
 276
 277   /* The outer (parent) loop or NULL if outermost loop.  */
 278   struct loop *outer;
 279
 280   /* The first inner (child) loop or NULL if innermost loop.  */
 281   struct loop *inner;
 282
 283   /* Link to the next (sibling) loop.  */
 284   struct loop *next;
 285
 286   /* Non-zero if the loop shares a header with another loop.  */
 287   int shared;
 288
 289   /* Non-zero if the loop is invalid (e.g., contains setjmp.).  */
 290   int invalid;
 291
 292   /* Auxiliary info specific to a pass.  */
 293   void *aux;
 294
 295   /* The following are currently used by loop.c but they are likely to
 296      disappear as loop.c is converted to use the CFG.  */
 297
 298   /* Non-zero if the loop has a NOTE_INSN_LOOP_VTOP.  */
 299   rtx vtop;
 300
 301   /* Non-zero if the loop has a NOTE_INSN_LOOP_CONT.
 302      A continue statement will generate a branch to NEXT_INSN (cont).  */
 303   rtx cont;
 304
 305   /* The dominator of cont.  */
 306   rtx cont_dominator;
 307
 308   /* The NOTE_INSN_LOOP_BEG.  */
 309   rtx start;
 310
 311   /* The NOTE_INSN_LOOP_END.  */
 312   rtx end;
 313
 314   /* For a rotated loop that is entered near the bottom,
 315      this is the label at the top.  Otherwise it is zero.  */
 316   rtx top;
 317
 318   /* Place in the loop where control enters.  */
 319   rtx scan_start;
 320
 321   /* List of all LABEL_REFs which refer to code labels outside the
 322      loop.  Used by routines that need to know all loop exits, such as
 323      final_biv_value and final_giv_value.
 324
 325      This does not include loop exits due to return instructions.
 326      This is because all bivs and givs are pseudos, and hence must be
 327      dead after a return, so the presense of a return does not affect
 328      any of the optimizations that use this info.  It is simpler to
 329      just not include return instructions on this list.  */
 330   rtx exit_labels;
 331
 332   /* The number of LABEL_REFs on exit_labels for this loop and all
 333      loops nested inside it.  */
 334   int exit_count;
 335 };
 336
 337
 338 /* Structure to hold CFG information about natural loops within a function.  */
 339 struct loops
 340 {
 341   /* Number of natural loops in the function.  */
 342   int num;
 343
 344   /* Maxium nested loop level in the function.  */
 345   int levels;
 346
 347   /* Array of natural loop descriptors (scanning this array in reverse order
 348      will find the inner loops before their enclosing outer loops).  */
 349   struct loop *array;
 350
 351   /* Pointer to root of loop heirachy tree.  */
 352   struct loop *tree;
 353
 354   /* Information derived from the CFG.  */
 355   struct cfg
 356   {
 357     /* The bitmap vector of dominators or NULL if not computed.  */
 358     sbitmap *dom;
 359
 360     /* The ordering of the basic blocks in a depth first search.  */
 361     int *dfs_order;
 362   } cfg;
 363
 364   /* Headers shared by multiple loops that should be merged.  */
 365   sbitmap shared_headers;
 366 };
 367
 368 extern int flow_loops_find PARAMS ((struct loops *));
 369 extern void flow_loops_free PARAMS ((struct loops *));
 370 extern void flow_loops_dump PARAMS ((const struct loops *, FILE *, int));
 371
 372
 373 /* This structure maintains an edge list vector.  */
 374 struct edge_list
 375 {
 376   int num_blocks;
 377   int num_edges;
 378   edge *index_to_edge;
 379 };
 380
 381 /* This is the value which indicates no edge is present.  */
 382 #define EDGE_INDEX_NO_EDGE      -1
 383
 384 /* EDGE_INDEX returns an integer index for an edge, or EDGE_INDEX_NO_EDGE
 385    if there is no edge between the 2 basic blocks.  */
 386 #define EDGE_INDEX(el, pred, succ) (find_edge_index ((el), (pred), (succ)))
 387
 388 /* INDEX_EDGE_PRED_BB and INDEX_EDGE_SUCC_BB return a pointer to the basic
 389    block which is either the pred or succ end of the indexed edge.  */
 390 #define INDEX_EDGE_PRED_BB(el, index)   ((el)->index_to_edge[(index)]->src)
 391 #define INDEX_EDGE_SUCC_BB(el, index)   ((el)->index_to_edge[(index)]->dest)
 392
 393 /* INDEX_EDGE returns a pointer to the edge.  */
 394 #define INDEX_EDGE(el, index)           ((el)->index_to_edge[(index)])
 395
 396 /* Number of edges in the compressed edge list.  */
 397 #define NUM_EDGES(el)                   ((el)->num_edges)
 398
 399 struct edge_list * create_edge_list     PARAMS ((void));
 400 void free_edge_list                     PARAMS ((struct edge_list *));
 401 void print_edge_list                    PARAMS ((FILE *, struct edge_list *));
 402 void verify_edge_list                   PARAMS ((FILE *, struct edge_list *));
 403 int find_edge_index                     PARAMS ((struct edge_list *,
 404                                                  basic_block, basic_block));
 405
 406 extern void compute_flow_dominators     PARAMS ((sbitmap *, sbitmap *));
 407 extern void compute_immediate_dominators        PARAMS ((int *, sbitmap *));
 408
 409
 410 enum update_life_extent
 411 {
 412   UPDATE_LIFE_LOCAL = 0,
 413   UPDATE_LIFE_GLOBAL = 1,
 414   UPDATE_LIFE_GLOBAL_RM_NOTES = 2
 415 };
 416
 417 /* Flags for life_analysis and update_life_info.  */
 418
 419 #define PROP_DEATH_NOTES        1       /* Create DEAD and UNUSED notes.  */
 420 #define PROP_LOG_LINKS          2       /* Create LOG_LINKS.  */
 421 #define PROP_REG_INFO           4       /* Update regs_ever_live et al.  */
 422 #define PROP_KILL_DEAD_CODE     8       /* Remove dead code.  */
 423 #define PROP_SCAN_DEAD_CODE     16      /* Scan for dead code.  */
 424 #define PROP_AUTOINC            32      /* Create autoinc mem references.  */
 425 #define PROP_FINAL              63      /* All of the above.  */
 426
 427 extern void update_life_info    PARAMS ((sbitmap, enum update_life_extent,
 428                                          int));
 429 extern int count_or_remove_death_notes  PARAMS ((sbitmap, int));
 430
 431 /* In lcm.c */
 432 extern struct edge_list *pre_edge_lcm   PARAMS ((FILE *, int, sbitmap *,
 433                                                  sbitmap *, sbitmap *,
 434                                                  sbitmap *, sbitmap **,
 435                                                  sbitmap **));
 436 extern struct edge_list *pre_edge_rev_lcm PARAMS ((FILE *, int, sbitmap *,
 437                                                    sbitmap *, sbitmap *,
 438                                                    sbitmap *, sbitmap **,
 439                                                    sbitmap **));
 440 extern void compute_available           PARAMS ((sbitmap *, sbitmap *,
 441                                                  sbitmap *, sbitmap *));
 442 extern void optimize_mode_switching     PARAMS ((FILE *));
 443
 444 /* In emit-rtl.c.  */
 445 extern rtx emit_block_insn_after        PARAMS ((rtx, rtx, basic_block));
 446 extern rtx emit_block_insn_before       PARAMS ((rtx, rtx, basic_block));
 447
 448 /* In predict.c */
 449 extern void estimate_probability        PARAMS ((struct loops *));
 450
 451 /* In flow.c */
 452 extern void reorder_basic_blocks        PARAMS ((void));
 453 extern void dump_bb                     PARAMS ((basic_block, FILE *));
 454 extern void debug_bb                    PARAMS ((basic_block));
 455 extern void debug_bb_n                  PARAMS ((int));
 456 extern void dump_regset                 PARAMS ((regset, FILE *));
 457 extern void debug_regset                PARAMS ((regset));
 458
 459 /* This function is always defined so it can be called from the
 460    debugger, and it is declared extern so we don't get warnings about
 461    it being unused. */
 462 extern void verify_flow_info            PARAMS ((void));
 463 extern int flow_loop_outside_edge_p     PARAMS ((const struct loop *, edge));
 464
 465 typedef struct conflict_graph_def *conflict_graph;
 466
 467 /* Callback function when enumerating conflicts.  The arguments are
 468    the smaller and larger regno in the conflict.  Returns zero if
 469    enumeration is to continue, non-zero to halt enumeration.  */
 470 typedef int (*conflict_graph_enum_fn) (int, int, void *);
 471
 472
 473 /* Prototypes of operations on conflict graphs.  */
 474
 475 extern conflict_graph conflict_graph_new
 476                                         PARAMS ((int));
 477 extern void conflict_graph_delete       PARAMS ((conflict_graph));
 478 extern int conflict_graph_add           PARAMS ((conflict_graph,
 479                                                  int, int));
 480 extern int conflict_graph_conflict_p    PARAMS ((conflict_graph,
 481                                                  int, int));
 482 extern void conflict_graph_enum         PARAMS ((conflict_graph, int,
 483                                                  conflict_graph_enum_fn,
 484                                                  void *));
 485 extern void conflict_graph_merge_regs   PARAMS ((conflict_graph, int,
 486                                                  int));
 487 extern void conflict_graph_print        PARAMS ((conflict_graph, FILE*));
 488 extern conflict_graph conflict_graph_compute
 489                                         PARAMS ((regset,
 490                                                  partition));
 491
 492 #endif /* _BASIC_BLOCK_H */