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 void sese_reset_aux_in_loops (sese);
  72 extern tree scalar_evolution_in_region (sese, loop_p, tree);
  73
  74 /* Check that SESE contains LOOP.  */
  75
  76 static inline bool
  77 sese_contains_loop (sese sese, struct loop *loop)
  78 {
  79   return bitmap_bit_p (SESE_LOOPS (sese), loop->num);
  80 }
  81
  82 /* The number of parameters in REGION. */
  83
  84 static inline unsigned
  85 sese_nb_params (sese region)
  86 {
  87   return VEC_length (tree, SESE_PARAMS (region));
  88 }
  89
  90 /* Checks whether BB is contained in the region delimited by ENTRY and
  91    EXIT blocks.  */
  92
  93 static inline bool
  94 bb_in_region (basic_block bb, basic_block entry, basic_block exit)
  95 {
  96 #ifdef ENABLE_CHECKING
  97   {
  98     edge e;
  99     edge_iterator ei;
 100
 101     /* Check that there are no edges coming in the region: all the
 102        predecessors of EXIT are dominated by ENTRY.  */
 103     FOR_EACH_EDGE (e, ei, exit->preds)
 104       dominated_by_p (CDI_DOMINATORS, e->src, entry);
 105
 106     /* Check that there are no edges going out of the region: the
 107        entry is post-dominated by the exit.  FIXME: This cannot be
 108        checked right now as the CDI_POST_DOMINATORS are needed.  */
 109   }
 110 #endif
 111
 112   return dominated_by_p (CDI_DOMINATORS, bb, entry)
 113          && !(dominated_by_p (CDI_DOMINATORS, bb, exit)
 114               && !dominated_by_p (CDI_DOMINATORS, entry, exit));
 115 }
 116
 117 /* Checks whether BB is contained in the region delimited by ENTRY and
 118    EXIT blocks.  */
 119
 120 static inline bool
 121 bb_in_sese_p (basic_block bb, sese region)
 122 {
 123   basic_block entry = SESE_ENTRY_BB (region);
 124   basic_block exit = SESE_EXIT_BB (region);
 125
 126   return bb_in_region (bb, entry, exit);
 127 }
 128
 129 /* Returns true when NAME is defined in REGION.  */
 130
 131 static inline bool
 132 defined_in_sese_p (tree name, sese region)
 133 {
 134   gimple stmt = SSA_NAME_DEF_STMT (name);
 135   basic_block bb = gimple_bb (stmt);
 136
 137   return bb && bb_in_sese_p (bb, region);
 138 }
 139
 140 /* Returns true when LOOP is in REGION.  */
 141
 142 static inline bool
 143 loop_in_sese_p (struct loop *loop, sese region)
 144 {
 145   return (bb_in_sese_p (loop->header, region)
 146           && bb_in_sese_p (loop->latch, region));
 147 }
 148
 149 /* Returns the loop depth of LOOP in REGION.  The loop depth
 150    is the same as the normal loop depth, but limited by a region.
 151
 152    Example:
 153
 154    loop_0
 155      loop_1
 156        {
 157          S0
 158             <- region start
 159          S1
 160
 161          loop_2
 162            S2
 163
 164          S3
 165             <- region end
 166        }
 167
 168     loop_0 does not exist in the region -> invalid
 169     loop_1 exists, but is not completely contained in the region -> depth 0
 170     loop_2 is completely contained -> depth 1  */
 171
 172 static inline unsigned int
 173 sese_loop_depth (sese region, loop_p loop)
 174 {
 175   unsigned int depth = 0;
 176
 177   gcc_assert ((!loop_in_sese_p (loop, region)
 178                && (SESE_ENTRY_BB (region)->loop_father == loop
 179                    || SESE_EXIT (region)->src->loop_father == loop))
 180               || loop_in_sese_p (loop, region));
 181
 182   while (loop_in_sese_p (loop, region))
 183     {
 184       depth++;
 185       loop = loop_outer (loop);
 186     }
 187
 188   return depth;
 189 }
 190
 191 /* Returns the block preceding the entry of a SESE.  */
 192
 193 static inline basic_block
 194 block_before_sese (sese sese)
 195 {
 196   return SESE_ENTRY (sese)->src;
 197 }
 198
 199 /* Stores the INDEX in a vector for a given clast NAME.  */
 200
 201 typedef struct clast_name_index {
 202   int index;
 203   const char *name;
 204 } *clast_name_index_p;
 205
 206 /* Returns a pointer to a new element of type clast_name_index_p built
 207    from NAME and INDEX.  */
 208
 209 static inline clast_name_index_p
 210 new_clast_name_index (const char *name, int index)
 211 {
 212   clast_name_index_p res = XNEW (struct clast_name_index);
 213
 214   res->name = name;
 215   res->index = index;
 216   return res;
 217 }
 218
 219 /* For a given clast NAME, returns -1 if it does not correspond to any
 220    parameter, or otherwise, returns the index in the PARAMS or
 221    SCATTERING_DIMENSIONS vector.  */
 222
 223 static inline int
 224 clast_name_to_index (const char *name, htab_t index_table)
 225 {
 226   struct clast_name_index tmp;
 227   PTR *slot;
 228
 229   tmp.name = name;
 230   slot = htab_find_slot (index_table, &tmp, NO_INSERT);
 231
 232   if (slot && *slot)
 233     return ((struct clast_name_index *) *slot)->index;
 234
 235   return -1;
 236 }
 237
 238 /* Records in INDEX_TABLE the INDEX for NAME.  */
 239
 240 static inline void
 241 save_clast_name_index (htab_t index_table, const char *name, int index)
 242 {
 243   struct clast_name_index tmp;
 244   PTR *slot;
 245
 246   tmp.name = name;
 247   slot = htab_find_slot (index_table, &tmp, INSERT);
 248
 249   if (slot)
 250     *slot = new_clast_name_index (name, index);
 251 }
 252
 253 /* Print to stderr the element ELT.  */
 254
 255 static inline void
 256 debug_clast_name_index (clast_name_index_p elt)
 257 {
 258   fprintf (stderr, "(index = %d, name = %s)\n", elt->index, elt->name);
 259 }
 260
 261 /* Helper function for debug_rename_map.  */
 262
 263 static inline int
 264 debug_clast_name_indexes_1 (void **slot, void *s ATTRIBUTE_UNUSED)
 265 {
 266   struct clast_name_index *entry = (struct clast_name_index *) *slot;
 267   debug_clast_name_index (entry);
 268   return 1;
 269 }
 270
 271 /* Print to stderr all the elements of MAP.  */
 272
 273 static inline void
 274 debug_clast_name_indexes (htab_t map)
 275 {
 276   htab_traverse (map, debug_clast_name_indexes_1, NULL);
 277 }
 278
 279 /* Computes a hash function for database element ELT.  */
 280
 281 static inline hashval_t
 282 clast_name_index_elt_info (const void *elt)
 283 {
 284   return htab_hash_pointer (((const struct clast_name_index *) elt)->name);
 285 }
 286
 287 /* Compares database elements E1 and E2.  */
 288
 289 static inline int
 290 eq_clast_name_indexes (const void *e1, const void *e2)
 291 {
 292   const struct clast_name_index *elt1 = (const struct clast_name_index *) e1;
 293   const struct clast_name_index *elt2 = (const struct clast_name_index *) e2;
 294
 295   return (elt1->name == elt2->name);
 296 }
 297
 298 \f
 299
 300 /* A single entry single exit specialized for conditions.  */
 301
 302 typedef struct ifsese_s {
 303   sese region;
 304   sese true_region;
 305   sese false_region;
 306 } *ifsese;
 307
 308 extern void if_region_set_false_region (ifsese, sese);
 309 extern ifsese create_if_region_on_edge (edge, tree);
 310 extern ifsese move_sese_in_condition (sese);
 311 extern edge get_true_edge_from_guard_bb (basic_block);
 312 extern edge get_false_edge_from_guard_bb (basic_block);
 313
 314 static inline edge
 315 if_region_entry (ifsese if_region)
 316 {
 317   return SESE_ENTRY (if_region->region);
 318 }
 319
 320 static inline edge
 321 if_region_exit (ifsese if_region)
 322 {
 323   return SESE_EXIT (if_region->region);
 324 }
 325
 326 static inline basic_block
 327 if_region_get_condition_block (ifsese if_region)
 328 {
 329   return if_region_entry (if_region)->dest;
 330 }
 331
 332 /* Structure containing the mapping between the old names and the new
 333    names used after block copy in the new loop context.  */
 334 typedef struct rename_map_elt_s
 335 {
 336   tree old_name, expr;
 337 } *rename_map_elt;
 338
 339 DEF_VEC_P(rename_map_elt);
 340 DEF_VEC_ALLOC_P (rename_map_elt, heap);
 341
 342 extern void debug_rename_map (htab_t);
 343 extern hashval_t rename_map_elt_info (const void *);
 344 extern int eq_rename_map_elts (const void *, const void *);
 345 extern void set_rename (htab_t, tree, tree);
 346
 347 /* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW.  */
 348
 349 static inline rename_map_elt
 350 new_rename_map_elt (tree old_name, tree expr)
 351 {
 352   rename_map_elt res;
 353
 354   res = XNEW (struct rename_map_elt_s);
 355   res->old_name = old_name;
 356   res->expr = expr;
 357
 358   return res;
 359 }
 360
 361 /* Structure containing the mapping between the CLooG's induction
 362    variable and the type of the old induction variable.  */
 363 typedef struct ivtype_map_elt_s
 364 {
 365   tree type;
 366   const char *cloog_iv;
 367 } *ivtype_map_elt;
 368
 369 extern void debug_ivtype_map (htab_t);
 370 extern hashval_t ivtype_map_elt_info (const void *);
 371 extern int eq_ivtype_map_elts (const void *, const void *);
 372
 373 /* Constructs a new SCEV_INFO_STR structure for VAR and INSTANTIATED_BELOW.  */
 374
 375 static inline ivtype_map_elt
 376 new_ivtype_map_elt (const char *cloog_iv, tree type)
 377 {
 378   ivtype_map_elt res;
 379
 380   res = XNEW (struct ivtype_map_elt_s);
 381   res->cloog_iv = cloog_iv;
 382   res->type = type;
 383
 384   return res;
 385 }
 386
 387 /* Free and compute again all the dominators information.  */
 388
 389 static inline void
 390 recompute_all_dominators (void)
 391 {
 392   mark_irreducible_loops ();
 393   free_dominance_info (CDI_DOMINATORS);
 394   free_dominance_info (CDI_POST_DOMINATORS);
 395   calculate_dominance_info (CDI_DOMINATORS);
 396   calculate_dominance_info (CDI_POST_DOMINATORS);
 397 }
 398
 399 typedef struct gimple_bb
 400 {
 401   basic_block bb;
 402
 403   /* Lists containing the restrictions of the conditional statements
 404      dominating this bb.  This bb can only be executed, if all conditions
 405      are true.
 406
 407      Example:
 408
 409      for (i = 0; i <= 20; i++)
 410      {
 411        A
 412
 413        if (2i <= 8)
 414          B
 415      }
 416
 417      So for B there is an additional condition (2i <= 8).
 418
 419      List of COND_EXPR and SWITCH_EXPR.  A COND_EXPR is true only if the
 420      corresponding element in CONDITION_CASES is not NULL_TREE.  For a
 421      SWITCH_EXPR the corresponding element in CONDITION_CASES is a
 422      CASE_LABEL_EXPR.  */
 423   VEC (gimple, heap) *conditions;
 424   VEC (gimple, heap) *condition_cases;
 425   VEC (data_reference_p, heap) *data_refs;
 426   htab_t cloog_iv_types;
 427 } *gimple_bb_p;
 428
 429 #define GBB_BB(GBB) GBB->bb
 430 #define GBB_DATA_REFS(GBB) GBB->data_refs
 431 #define GBB_CONDITIONS(GBB) GBB->conditions
 432 #define GBB_CONDITION_CASES(GBB) GBB->condition_cases
 433 #define GBB_CLOOG_IV_TYPES(GBB) GBB->cloog_iv_types
 434
 435 /* Return the innermost loop that contains the basic block GBB.  */
 436
 437 static inline struct loop *
 438 gbb_loop (struct gimple_bb *gbb)
 439 {
 440   return GBB_BB (gbb)->loop_father;
 441 }
 442
 443 /* Returns the gimple loop, that corresponds to the loop_iterator_INDEX.
 444    If there is no corresponding gimple loop, we return NULL.  */
 445
 446 static inline loop_p
 447 gbb_loop_at_index (gimple_bb_p gbb, sese region, int index)
 448 {
 449   loop_p loop = gbb_loop (gbb);
 450   int depth = sese_loop_depth (region, loop);
 451
 452   while (--depth > index)
 453     loop = loop_outer (loop);
 454
 455   gcc_assert (sese_contains_loop (region, loop));
 456
 457   return loop;
 458 }
 459
 460 /* The number of common loops in REGION for GBB1 and GBB2.  */
 461
 462 static inline int
 463 nb_common_loops (sese region, gimple_bb_p gbb1, gimple_bb_p gbb2)
 464 {
 465   loop_p l1 = gbb_loop (gbb1);
 466   loop_p l2 = gbb_loop (gbb2);
 467   loop_p common = find_common_loop (l1, l2);
 468
 469   return sese_loop_depth (region, common);
 470 }
 471
 472 extern void print_gimple_bb (FILE *, gimple_bb_p, int, int);
 473 extern void debug_gbb (gimple_bb_p, int);
 474
 475 #endif