gcc/sese.h

   1 /* Single entry single exit control flow regions.
   2    Copyright (C) 2008, 2009  Free Software Foundation, Inc.
   3    Contributed by Jan Sjodin <jan.sjodin@amd.com> and
   4    Sebastian Pop <sebastian.pop@amd.com>.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #ifndef GCC_SESE_H
  23 #define GCC_SESE_H
  24
  25 /* A Single Entry, Single Exit region is a part of the CFG delimited
  26    by two edges.  */
  27 typedef struct sese_s
  28 {
  29   /* Single ENTRY and single EXIT from the SESE region.  */
  30   edge entry, exit;
  31
  32   /* Parameters used within the SCOP.  */
  33   VEC (tree, heap) *params;
  34
  35   /* Used to quickly retrieve the index of a parameter in PARAMS.  */
  36   htab_t params_index;
  37
  38   /* Store the names of the parameters that are passed to CLooG.  */
  39   char **params_names;
  40
  41   /* Loops completely contained in the SCOP.  */
  42   bitmap loops;
  43   VEC (loop_p, heap) *loop_nest;
  44
  45   /* Are we allowed to add more params?  This is for debugging purpose.  We
  46      can only add new params before generating the bb domains, otherwise they
  47      become invalid.  */
  48   bool add_params;
  49 } *sese;
  50
  51 #define SESE_ENTRY(S) (S->entry)
  52 #define SESE_ENTRY_BB(S) (S->entry->dest)
  53 #define SESE_EXIT(S) (S->exit)
  54 #define SESE_EXIT_BB(S) (S->exit->dest)
  55 #define SESE_PARAMS(S) (S->params)
  56 #define SESE_PARAMS_INDEX(S) (S->params_index)
  57 #define SESE_PARAMS_NAMES(S) (S->params_names)
  58 #define SESE_LOOPS(S) (S->loops)
  59 #define SESE_LOOP_NEST(S) (S->loop_nest)
  60 #define SESE_ADD_PARAMS(S) (S->add_params)
  61
  62 extern sese new_sese (edge, edge);
  63 extern void free_sese (sese);
  64 extern void sese_insert_phis_for_liveouts (sese, basic_block, edge, edge);
  65 extern void sese_adjust_liveout_phis (sese, htab_t, basic_block, edge, edge);
  66 extern void build_sese_loop_nests (sese);
  67 extern edge copy_bb_and_scalar_dependences (basic_block, sese, edge, htab_t);
  68 extern struct loop *outermost_loop_in_sese (sese, basic_block);
  69 extern void insert_loop_close_phis (htab_t, loop_p);
  70 extern void insert_guard_phis (basic_block, edge, edge, htab_t, htab_t);
  71 extern tree scalar_evolution_in_region (sese, loop_p, tree);
  72
  73 /* Check that SESE contains LOOP.  */
  74
  75 static inline bool
  76 sese_contains_loop (sese sese, struct loop *loop)
  77 {
  78   return bitmap_bit_p (SESE_LOOPS (sese), loop->num);
  79 }
  80
  81 /* The number of parameters in REGION. */
  82
  83 static inline unsigned
  84 sese_nb_params (sese region)
  85 {
  86   return VEC_length (tree, SESE_PARAMS (region));
  87 }
  88
  89 /* Checks whether BB is contained in the region delimited by ENTRY and
  90    EXIT blocks.  */
  91
  92 static inline bool
  93 bb_in_region (basic_block bb, basic_block entry, basic_block exit)
  94 {
  95 #ifdef ENABLE_CHECKING
  96   {
  97     edge e;
  98     edge_iterator ei;
  99
 100     /* Check that there are no edges coming in the region: all the
 101        predecessors of EXIT are dominated by ENTRY.  */
 102     FOR_EACH_EDGE (e, ei, exit->preds)
 103       dominated_by_p (CDI_DOMINATORS, e->src, entry);
 104
 105     /* Check that there are no edges going out of the region: the
 106        entry is post-dominated by the exit.  FIXME: This cannot be
 107        checked right now as the CDI_POST_DOMINATORS are needed.  */
 108   }
 109 #endif
 110
 111   return dominated_by_p (CDI_DOMINATORS, bb, entry)
 112          && !(dominated_by_p (CDI_DOMINATORS, bb, exit)
 113               && !dominated_by_p (CDI_DOMINATORS, entry, exit));
 114 }
 115
 116 /* Checks whether BB is contained in the region delimited by ENTRY and
 117    EXIT blocks.  */
 118
 119 static inline bool
 120 bb_in_sese_p (basic_block bb, sese region)
 121 {
 122   basic_block entry = SESE_ENTRY_BB (region);
 123   basic_block exit = SESE_EXIT_BB (region);
 124
 125   return bb_in_region (bb, entry, exit);
 126 }
 127
 128 /* Returns true when NAME is defined in REGION.  */
 129
 130 static inline bool
 131 defined_in_sese_p (tree name, sese region)
 132 {
 133   gimple stmt = SSA_NAME_DEF_STMT (name);
 134   basic_block bb = gimple_bb (stmt);
 135
 136   return bb && bb_in_sese_p (bb, region);
 137 }
 138
 139 /* Returns true when LOOP is in REGION.  */
 140
 141 static inline bool
 142 loop_in_sese_p (struct loop *loop, sese region)
 143 {
 144   return (bb_in_sese_p (loop->header, region)
 145           && bb_in_sese_p (loop->latch, region));
 146 }
 147
 148 /* Returns the loop depth of LOOP in REGION.  The loop depth
 149    is the same as the normal loop depth, but limited by a region.
 150
 151    Example:
 152
 153    loop_0
 154      loop_1
 155        {
 156          S0
 157             <- region start
 158          S1
 159
 160          loop_2
 161            S2
 162
 163          S3
 164             <- region end
 165        }
 166
 167     loop_0 does not exist in the region -> invalid
 168     loop_1 exists, but is not completely contained in the region -> depth 0
 169     loop_2 is completely contained -> depth 1  */
 170
 171 static inline unsigned int
 172 sese_loop_depth (sese region, loop_p loop)
 173 {
 174   unsigned int depth = 0;
 175
 176   gcc_assert ((!loop_in_sese_p (loop, region)
 177                && (SESE_ENTRY_BB (region)->loop_father == loop
 178                    || SESE_EXIT (region)->src->loop_father == loop))
 179               || loop_in_sese_p (loop, region));
 180
 181   while (loop_in_sese_p (loop, region))
 182     {
 183       depth++;
 184       loop = loop_outer (loop);
 185     }
 186
 187   return depth;
 188 }
 189
 190 /* Splits BB to make a single entry single exit region.  */
 191
 192 static inline sese
 193 split_region_for_bb (basic_block bb)
 194 {
 195   edge entry, exit;
 196
 197   if (single_pred_p (bb))
 198     entry = single_pred_edge (bb);
 199   else
 200     {
 201       entry = split_block_after_labels (bb);
 202       bb = single_succ (bb);
 203     }
 204
 205   if (single_succ_p (bb))
 206     exit = single_succ_edge (bb);
 207   else
 208     {
 209       gimple_stmt_iterator gsi = gsi_last_bb (bb);
 210       gsi_prev (&gsi);
 211       exit = split_block (bb, gsi_stmt (gsi));
 212     }
 213
 214   return new_sese (entry, exit);
 215 }
 216
 217 /* Returns the block preceding the entry of a SESE.  */
 218
 219 static inline basic_block
 220 block_before_sese (sese sese)
 221 {
 222   return SESE_ENTRY (sese)->src;
 223 }
 224
 225 /* Stores the INDEX in a vector for a given clast NAME.  */
 226
 227 typedef struct clast_name_index {
 228   int index;
 229   const char *name;
 230 } *clast_name_index_p;
 231
 232 /* Returns a pointer to a new element of type clast_name_index_p built
 233    from NAME and INDEX.  */
 234
 235 static inline clast_name_index_p
 236 new_clast_name_index (const char *name, int index)
 237 {
 238   clast_name_index_p res = XNEW (struct clast_name_index);
 239
 240   res->name = name;
 241   res->index = index;
 242   return res;
 243 }
 244
 245 /* For a given clast NAME, returns -1 if it does not correspond to any
 246    parameter, or otherwise, returns the index in the PARAMS or
 247    SCATTERING_DIMENSIONS vector.  */
 248
 249 static inline int
 250 clast_name_to_index (const char *name, htab_t index_table)
 251 {
 252   struct clast_name_index tmp;
 253   PTR *slot;
 254
 255   tmp.name = name;
 256   slot = htab_find_slot (index_table, &tmp, NO_INSERT);
 257
 258   if (slot && *slot)
 259     return ((struct clast_name_index *) *slot)->index;
 260
 261   return -1;
 262 }
 263
 264 /* Records in INDEX_TABLE the INDEX for NAME.  */
 265
 266 static inline void
 267 save_clast_name_index (htab_t index_table, const char *name, int index)
 268 {
 269   struct clast_name_index tmp;
 270   PTR *slot;
 271
 272   tmp.name = name;
 273   slot = htab_find_slot (index_table, &tmp, INSERT);
 274
 275   if (slot)
 276     *slot = new_clast_name_index (name, index);
 277 }
 278
 279 /* Print to stderr the element ELT.  */
 280
 281 static inline void
 282 debug_clast_name_index (clast_name_index_p elt)
 283 {
 284   fprintf (stderr, "(index = %d, name = %s)\n", elt->index, elt->name);
 285 }
 286
 287 /* Helper function for debug_rename_map.  */
 288
 289 static inline int
 290 debug_clast_name_indexes_1 (void **slot, void *s ATTRIBUTE_UNUSED)
 291 {
 292   struct clast_name_index *entry = (struct clast_name_index *) *slot;
 293   debug_clast_name_index (entry);
 294   return 1;
 295 }
 296
 297 /* Print to stderr all the elements of MAP.  */
 298
 299 static inline void
 300 debug_clast_name_indexes (htab_t map)
 301 {
 302   htab_traverse (map, debug_clast_name_indexes_1, NULL);
 303 }
 304
 305 /* Computes a hash function for database element ELT.  */
 306
 307 static inline hashval_t
 308 clast_name_index_elt_info (const void *elt)
 309 {
 310   return htab_hash_pointer (((const struct clast_name_index *) elt)->name);
 311 }
 312
 313 /* Compares database elements E1 and E2.  */
 314
 315 static inline int
 316 eq_clast_name_indexes (const void *e1, const void *e2)
 317 {
 318   const struct clast_name_index *elt1 = (const struct clast_name_index *) e1;
 319   const struct clast_name_index *elt2 = (const struct clast_name_index *) e2;
 320
 321   return (elt1->name == elt2->name);
 322 }
 323
 324 \f
 325
 326 /* A single entry single exit specialized for conditions.  */
 327
 328 typedef struct ifsese_s {
 329   sese region;
 330   sese true_region;
 331   sese false_region;
 332 } *ifsese;
 333
 334 extern void if_region_set_false_region (ifsese, sese);
 335 extern ifsese create_if_region_on_edge (edge, tree);
 336 extern ifsese move_sese_in_condition (sese);
 337 extern edge get_true_edge_from_guard_bb (basic_block);
 338 extern edge get_false_edge_from_guard_bb (basic_block);
 339
 340 static inline edge
 341 if_region_entry (ifsese if_region)
 342 {
 343   return SESE_ENTRY (if_region->region);
 344 }
 345
 346 static inline edge
 347 if_region_exit (ifsese if_region)
 348 {
 349   return SESE_EXIT (if_region->region);
 350 }
 351
 352 static inline basic_block
 353 if_region_get_condition_block (ifsese if_region)
 354 {
 355   return if_region_entry (if_region)->dest;
 356 }
 357
 358 /* Structure containing the mapping between the old names and the new
 359    names used after block copy in the new loop context.  */
 360 typedef struct rename_map_elt_s
 361 {
 362   tree old_name, expr;
 363 } *rename_map_elt;
 364
 365 DEF_VEC_P(rename_map_elt);
 366 DEF_VEC_ALLOC_P (rename_map_elt, heap);
 367
 368 extern void debug_rename_map (htab_t);
 369 extern hashval_t rename_map_elt_info (const void *);
 370 extern int eq_rename_map_elts (const void *, const void *);
 371 extern void set_rename (htab_t, tree, tree);
 372
 373 /* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW.  */
 374
 375 static inline rename_map_elt
 376 new_rename_map_elt (tree old_name, tree expr)
 377 {
 378   rename_map_elt res;
 379
 380   res = XNEW (struct rename_map_elt_s);
 381   res->old_name = old_name;
 382   res->expr = expr;
 383
 384   return res;
 385 }
 386
 387 /* Structure containing the mapping between the CLooG's induction
 388    variable and the type of the old induction variable.  */
 389 typedef struct ivtype_map_elt_s
 390 {
 391   tree type;
 392   const char *cloog_iv;
 393 } *ivtype_map_elt;
 394
 395 extern void debug_ivtype_map (htab_t);
 396 extern hashval_t ivtype_map_elt_info (const void *);
 397 extern int eq_ivtype_map_elts (const void *, const void *);
 398
 399 /* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW.  */
 400
 401 static inline ivtype_map_elt
 402 new_ivtype_map_elt (const char *cloog_iv, tree type)
 403 {
 404   ivtype_map_elt res;
 405
 406   res = XNEW (struct ivtype_map_elt_s);
 407   res->cloog_iv = cloog_iv;
 408   res->type = type;
 409
 410   return res;
 411 }
 412
 413 /* Free and compute again all the dominators information.  */
 414
 415 static inline void
 416 recompute_all_dominators (void)
 417 {
 418   mark_irreducible_loops ();
 419   free_dominance_info (CDI_DOMINATORS);
 420   free_dominance_info (CDI_POST_DOMINATORS);
 421   calculate_dominance_info (CDI_DOMINATORS);
 422   calculate_dominance_info (CDI_POST_DOMINATORS);
 423 }
 424
 425 typedef struct gimple_bb
 426 {
 427   basic_block bb;
 428
 429   /* Lists containing the restrictions of the conditional statements
 430      dominating this bb.  This bb can only be executed, if all conditions
 431      are true.
 432
 433      Example:
 434
 435      for (i = 0; i <= 20; i++)
 436      {
 437        A
 438
 439        if (2i <= 8)
 440          B
 441      }
 442
 443      So for B there is an additional condition (2i <= 8).
 444
 445      List of COND_EXPR and SWITCH_EXPR.  A COND_EXPR is true only if the
 446      corresponding element in CONDITION_CASES is not NULL_TREE.  For a
 447      SWITCH_EXPR the corresponding element in CONDITION_CASES is a
 448      CASE_LABEL_EXPR.  */
 449   VEC (gimple, heap) *conditions;
 450   VEC (gimple, heap) *condition_cases;
 451   VEC (data_reference_p, heap) *data_refs;
 452   htab_t cloog_iv_types;
 453 } *gimple_bb_p;
 454
 455 #define GBB_BB(GBB) GBB->bb
 456 #define GBB_DATA_REFS(GBB) GBB->data_refs
 457 #define GBB_CONDITIONS(GBB) GBB->conditions
 458 #define GBB_CONDITION_CASES(GBB) GBB->condition_cases
 459 #define GBB_CLOOG_IV_TYPES(GBB) GBB->cloog_iv_types
 460
 461 /* Return the innermost loop that contains the basic block GBB.  */
 462
 463 static inline struct loop *
 464 gbb_loop (struct gimple_bb *gbb)
 465 {
 466   return GBB_BB (gbb)->loop_father;
 467 }
 468
 469 /* Returns the gimple loop, that corresponds to the loop_iterator_INDEX.
 470    If there is no corresponding gimple loop, we return NULL.  */
 471
 472 static inline loop_p
 473 gbb_loop_at_index (gimple_bb_p gbb, sese region, int index)
 474 {
 475   loop_p loop = gbb_loop (gbb);
 476   int depth = sese_loop_depth (region, loop);
 477
 478   while (--depth > index)
 479     loop = loop_outer (loop);
 480
 481   gcc_assert (sese_contains_loop (region, loop));
 482
 483   return loop;
 484 }
 485
 486 /* The number of common loops in REGION for GBB1 and GBB2.  */
 487
 488 static inline int
 489 nb_common_loops (sese region, gimple_bb_p gbb1, gimple_bb_p gbb2)
 490 {
 491   loop_p l1 = gbb_loop (gbb1);
 492   loop_p l2 = gbb_loop (gbb2);
 493   loop_p common = find_common_loop (l1, l2);
 494
 495   return sese_loop_depth (region, common);
 496 }
 497
 498 extern void print_gimple_bb (FILE *, gimple_bb_p, int, int);
 499 extern void debug_gbb (gimple_bb_p, int);
 500
 501 #endif