gcc/sese.h

   1 /* Single entry single exit control flow regions.
   2    Copyright (C) 2008-2016 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 typedef hash_map<tree, tree> parameter_rename_map_t;
  26 typedef hash_map<basic_block, vec<basic_block> > bb_map_t;
  27 typedef hash_map<tree, vec<tree> > rename_map_t;
  28 typedef struct ifsese_s *ifsese;
  29 /* First phi is the new codegenerated phi second one is original phi.  */
  30 typedef std::pair <gphi *, gphi *> phi_rename;
  31 /* First edge is the init edge and second is the back edge w.r.t. a loop.  */
  32 typedef std::pair<edge, edge> init_back_edge_pair_t;
  33
  34 /* A Single Entry, Single Exit region is a part of the CFG delimited
  35    by two edges.  */
  36 struct sese_l
  37 {
  38   sese_l (edge e, edge x) : entry (e), exit (x) {}
  39
  40   operator bool () const { return entry && exit; }
  41
  42   edge entry;
  43   edge exit;
  44 };
  45
  46 /* Get the entry of an sese S.  */
  47
  48 static inline basic_block
  49 get_entry_bb (sese_l &s)
  50 {
  51   return s.entry->dest;
  52 }
  53
  54 /* Get the exit of an sese S.  */
  55
  56 static inline basic_block
  57 get_exit_bb (sese_l &s)
  58 {
  59   return s.exit->src;
  60 }
  61
  62 /* Returns the index of V where ELEM can be found. -1 Otherwise.  */
  63 template<typename T>
  64 int
  65 vec_find (const vec<T> &v, const T &elem)
  66 {
  67   int i;
  68   T t;
  69   FOR_EACH_VEC_ELT (v, i, t)
  70     if (elem == t)
  71       return i;
  72   return -1;
  73 }
  74
  75 /* A helper structure for bookkeeping information about a scop in graphite.  */
  76 typedef struct sese_info_t
  77 {
  78   /* The SESE region.  */
  79   sese_l region;
  80
  81   /* Parameters used within the SCOP.  */
  82   vec<tree> params;
  83
  84   /* Maps an old name to one or more new names.  When there are several new
  85      names, one has to select the definition corresponding to the immediate
  86      dominator.  */
  87   rename_map_t *rename_map;
  88
  89   /* Parameters to be renamed.  */
  90   parameter_rename_map_t *parameter_rename_map;
  91
  92   /* Loops completely contained in this SESE.  */
  93   vec<loop_p> loop_nest;
  94
  95   /* Basic blocks contained in this SESE.  */
  96   vec<basic_block> bbs;
  97
  98   /* Copied basic blocks indexed by the original bb.  */
  99   bb_map_t *copied_bb_map;
 100
 101   /* A vector of phi nodes to be updated when all arguments are available.  The
 102      pair contains first the old_phi and second the new_phi.  */
 103   vec<phi_rename> incomplete_phis;
 104
 105   /* The condition region generated for this sese.  */
 106   ifsese if_region;
 107
 108 } *sese_info_p;
 109
 110 extern sese_info_p new_sese_info (edge, edge);
 111 extern void free_sese_info (sese_info_p);
 112 extern void sese_insert_phis_for_liveouts (sese_info_p, basic_block, edge, edge);
 113 extern struct loop *outermost_loop_in_sese (sese_l &, basic_block);
 114 extern tree scalar_evolution_in_region (const sese_l &, loop_p, tree);
 115 extern bool scev_analyzable_p (tree, sese_l &);
 116 extern bool invariant_in_sese_p_rec (tree, const sese_l &, bool *);
 117
 118 /* The number of parameters in REGION. */
 119
 120 static inline unsigned
 121 sese_nb_params (sese_info_p region)
 122 {
 123   return region->params.length ();
 124 }
 125
 126 /* Checks whether BB is contained in the region delimited by ENTRY and
 127    EXIT blocks.  */
 128
 129 static inline bool
 130 bb_in_region (const_basic_block bb, const_basic_block entry, const_basic_block exit)
 131 {
 132   /* FIXME: PR67842.  */
 133 #if 0
 134   if (flag_checking)
 135     {
 136       edge e;
 137       edge_iterator ei;
 138
 139       /* Check that there are no edges coming in the region: all the
 140          predecessors of EXIT are dominated by ENTRY.  */
 141       FOR_EACH_EDGE (e, ei, exit->preds)
 142         gcc_assert (dominated_by_p (CDI_DOMINATORS, e->src, entry));
 143     }
 144 #endif
 145
 146   return dominated_by_p (CDI_DOMINATORS, bb, entry)
 147          && !(dominated_by_p (CDI_DOMINATORS, bb, exit)
 148               && !dominated_by_p (CDI_DOMINATORS, entry, exit));
 149 }
 150
 151 /* Checks whether BB is contained in the region delimited by ENTRY and
 152    EXIT blocks.  */
 153
 154 static inline bool
 155 bb_in_sese_p (basic_block bb, const sese_l &r)
 156 {
 157   return bb_in_region (bb, r.entry->dest, r.exit->dest);
 158 }
 159
 160 /* Returns true when STMT is defined in REGION.  */
 161
 162 static inline bool
 163 stmt_in_sese_p (gimple *stmt, const sese_l &r)
 164 {
 165   basic_block bb = gimple_bb (stmt);
 166   return bb && bb_in_sese_p (bb, r);
 167 }
 168
 169 /* Returns true when NAME is defined in REGION.  */
 170
 171 static inline bool
 172 defined_in_sese_p (tree name, const sese_l &r)
 173 {
 174   return stmt_in_sese_p (SSA_NAME_DEF_STMT (name), r);
 175 }
 176
 177 /* Returns true when LOOP is in REGION.  */
 178
 179 static inline bool
 180 loop_in_sese_p (struct loop *loop, const sese_l &region)
 181 {
 182   return (bb_in_sese_p (loop->header, region)
 183           && bb_in_sese_p (loop->latch, region));
 184 }
 185
 186 /* Returns the loop depth of LOOP in REGION.  The loop depth
 187    is the same as the normal loop depth, but limited by a region.
 188
 189    Example:
 190
 191    loop_0
 192      loop_1
 193        {
 194          S0
 195             <- region start
 196          S1
 197
 198          loop_2
 199            S2
 200
 201          S3
 202             <- region end
 203        }
 204
 205     loop_0 does not exist in the region -> invalid
 206     loop_1 exists, but is not completely contained in the region -> depth 0
 207     loop_2 is completely contained -> depth 1  */
 208
 209 static inline unsigned int
 210 sese_loop_depth (sese_l &region, loop_p loop)
 211 {
 212   unsigned int depth = 0;
 213
 214   while (loop_in_sese_p (loop, region))
 215     {
 216       depth++;
 217       loop = loop_outer (loop);
 218     }
 219
 220   return depth;
 221 }
 222
 223 /* A single entry single exit specialized for conditions.  */
 224
 225 typedef struct ifsese_s {
 226   sese_info_p region;
 227   sese_info_p true_region;
 228   sese_info_p false_region;
 229 } *ifsese;
 230
 231 extern void if_region_set_false_region (ifsese, sese_info_p);
 232 extern ifsese move_sese_in_condition (sese_info_p);
 233 extern void set_ifsese_condition (ifsese, tree);
 234 extern edge get_true_edge_from_guard_bb (basic_block);
 235 extern edge get_false_edge_from_guard_bb (basic_block);
 236
 237 static inline edge
 238 if_region_entry (ifsese if_region)
 239 {
 240   return if_region->region->region.entry;
 241 }
 242
 243 static inline edge
 244 if_region_exit (ifsese if_region)
 245 {
 246   return if_region->region->region.exit;
 247 }
 248
 249 static inline basic_block
 250 if_region_get_condition_block (ifsese if_region)
 251 {
 252   return if_region_entry (if_region)->dest;
 253 }
 254
 255 /* Free and compute again all the dominators information.  */
 256
 257 static inline void
 258 recompute_all_dominators (void)
 259 {
 260   mark_irreducible_loops ();
 261   free_dominance_info (CDI_DOMINATORS);
 262   calculate_dominance_info (CDI_DOMINATORS);
 263
 264   free_dominance_info (CDI_POST_DOMINATORS);
 265   calculate_dominance_info (CDI_POST_DOMINATORS);
 266 }
 267
 268 typedef std::pair <gimple *, tree> scalar_use;
 269
 270 typedef struct gimple_poly_bb
 271 {
 272   basic_block bb;
 273   struct poly_bb *pbb;
 274
 275   /* Lists containing the restrictions of the conditional statements
 276      dominating this bb.  This bb can only be executed, if all conditions
 277      are true.
 278
 279      Example:
 280
 281      for (i = 0; i <= 20; i++)
 282      {
 283        A
 284
 285        if (2i <= 8)
 286          B
 287      }
 288
 289      So for B there is an additional condition (2i <= 8).
 290
 291      List of COND_EXPR and SWITCH_EXPR.  A COND_EXPR is true only if the
 292      corresponding element in CONDITION_CASES is not NULL_TREE.  For a
 293      SWITCH_EXPR the corresponding element in CONDITION_CASES is a
 294      CASE_LABEL_EXPR.  */
 295   vec<gimple *> conditions;
 296   vec<gimple *> condition_cases;
 297   vec<data_reference_p> data_refs;
 298   vec<scalar_use> read_scalar_refs;
 299   vec<tree> write_scalar_refs;
 300 } *gimple_poly_bb_p;
 301
 302 #define GBB_BB(GBB) (GBB)->bb
 303 #define GBB_PBB(GBB) (GBB)->pbb
 304 #define GBB_DATA_REFS(GBB) (GBB)->data_refs
 305 #define GBB_CONDITIONS(GBB) (GBB)->conditions
 306 #define GBB_CONDITION_CASES(GBB) (GBB)->condition_cases
 307
 308 /* Return the innermost loop that contains the basic block GBB.  */
 309
 310 static inline struct loop *
 311 gbb_loop (gimple_poly_bb_p gbb)
 312 {
 313   return GBB_BB (gbb)->loop_father;
 314 }
 315
 316 /* Returns the gimple loop, that corresponds to the loop_iterator_INDEX.
 317    If there is no corresponding gimple loop, we return NULL.  */
 318
 319 static inline loop_p
 320 gbb_loop_at_index (gimple_poly_bb_p gbb, sese_l &region, int index)
 321 {
 322   loop_p loop = gbb_loop (gbb);
 323   int depth = sese_loop_depth (region, loop);
 324
 325   while (--depth > index)
 326     loop = loop_outer (loop);
 327
 328   gcc_assert (loop_in_sese_p (loop, region));
 329
 330   return loop;
 331 }
 332
 333 /* The number of common loops in REGION for GBB1 and GBB2.  */
 334
 335 static inline int
 336 nb_common_loops (sese_l &region, gimple_poly_bb_p gbb1, gimple_poly_bb_p gbb2)
 337 {
 338   loop_p l1 = gbb_loop (gbb1);
 339   loop_p l2 = gbb_loop (gbb2);
 340   loop_p common = find_common_loop (l1, l2);
 341
 342   return sese_loop_depth (region, common);
 343 }
 344
 345 #endif