gcc/sese.h

   1 /* Single entry single exit control flow regions.
   2    Copyright (C) 2008-2017 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 void print_edge (FILE *file, const_edge e);
  47 void print_sese (FILE *file, const sese_l &s);
  48 void dump_edge (const_edge e);
  49 void dump_sese (const sese_l &);
  50
  51 /* Get the entry of an sese S.  */
  52
  53 static inline basic_block
  54 get_entry_bb (sese_l &s)
  55 {
  56   return s.entry->dest;
  57 }
  58
  59 /* Get the exit of an sese S.  */
  60
  61 static inline basic_block
  62 get_exit_bb (sese_l &s)
  63 {
  64   return s.exit->src;
  65 }
  66
  67 /* Returns the index of V where ELEM can be found. -1 Otherwise.  */
  68 template<typename T>
  69 int
  70 vec_find (const vec<T> &v, const T &elem)
  71 {
  72   int i;
  73   T t;
  74   FOR_EACH_VEC_ELT (v, i, t)
  75     if (elem == t)
  76       return i;
  77   return -1;
  78 }
  79
  80 /* A helper structure for bookkeeping information about a scop in graphite.  */
  81 typedef struct sese_info_t
  82 {
  83   /* The SESE region.  */
  84   sese_l region;
  85
  86   /* Parameters used within the SCOP.  */
  87   vec<tree> params;
  88
  89   /* Maps an old name to one or more new names.  When there are several new
  90      names, one has to select the definition corresponding to the immediate
  91      dominator.  */
  92   rename_map_t *rename_map;
  93
  94   /* Parameters to be renamed.  */
  95   parameter_rename_map_t *parameter_rename_map;
  96
  97   /* Loops completely contained in this SESE.  */
  98   vec<loop_p> loop_nest;
  99
 100   /* Basic blocks contained in this SESE.  */
 101   vec<basic_block> bbs;
 102
 103   /* Copied basic blocks indexed by the original bb.  */
 104   bb_map_t *copied_bb_map;
 105
 106   /* A vector of phi nodes to be updated when all arguments are available.  The
 107      pair contains first the old_phi and second the new_phi.  */
 108   vec<phi_rename> incomplete_phis;
 109
 110   /* The condition region generated for this sese.  */
 111   ifsese if_region;
 112
 113 } *sese_info_p;
 114
 115 extern sese_info_p new_sese_info (edge, edge);
 116 extern void free_sese_info (sese_info_p);
 117 extern void sese_insert_phis_for_liveouts (sese_info_p, basic_block, edge, edge);
 118 extern struct loop *outermost_loop_in_sese (sese_l &, basic_block);
 119 extern tree scalar_evolution_in_region (const sese_l &, loop_p, tree);
 120 extern bool scev_analyzable_p (tree, sese_l &);
 121 extern bool invariant_in_sese_p_rec (tree, const sese_l &, bool *);
 122
 123 /* The number of parameters in REGION. */
 124
 125 static inline unsigned
 126 sese_nb_params (sese_info_p region)
 127 {
 128   return region->params.length ();
 129 }
 130
 131 /* Checks whether BB is contained in the region delimited by ENTRY and
 132    EXIT blocks.  */
 133
 134 static inline bool
 135 bb_in_region (const_basic_block bb, const_basic_block entry, const_basic_block exit)
 136 {
 137   /* FIXME: PR67842.  */
 138 #if 0
 139   if (flag_checking)
 140     {
 141       edge e;
 142       edge_iterator ei;
 143
 144       /* Check that there are no edges coming in the region: all the
 145          predecessors of EXIT are dominated by ENTRY.  */
 146       FOR_EACH_EDGE (e, ei, exit->preds)
 147         gcc_assert (dominated_by_p (CDI_DOMINATORS, e->src, entry));
 148     }
 149 #endif
 150
 151   return dominated_by_p (CDI_DOMINATORS, bb, entry)
 152          && !(dominated_by_p (CDI_DOMINATORS, bb, exit)
 153               && !dominated_by_p (CDI_DOMINATORS, entry, exit));
 154 }
 155
 156 /* Checks whether BB is contained in the region delimited by ENTRY and
 157    EXIT blocks.  */
 158
 159 static inline bool
 160 bb_in_sese_p (basic_block bb, const sese_l &r)
 161 {
 162   return bb_in_region (bb, r.entry->dest, r.exit->dest);
 163 }
 164
 165 /* Returns true when STMT is defined in REGION.  */
 166
 167 static inline bool
 168 stmt_in_sese_p (gimple *stmt, const sese_l &r)
 169 {
 170   basic_block bb = gimple_bb (stmt);
 171   return bb && bb_in_sese_p (bb, r);
 172 }
 173
 174 /* Returns true when NAME is defined in REGION.  */
 175
 176 static inline bool
 177 defined_in_sese_p (tree name, const sese_l &r)
 178 {
 179   return stmt_in_sese_p (SSA_NAME_DEF_STMT (name), r);
 180 }
 181
 182 /* Returns true when LOOP is in REGION.  */
 183
 184 static inline bool
 185 loop_in_sese_p (struct loop *loop, const sese_l &region)
 186 {
 187   return (bb_in_sese_p (loop->header, region)
 188           && bb_in_sese_p (loop->latch, region));
 189 }
 190
 191 /* Returns the loop depth of LOOP in REGION.  The loop depth
 192    is the same as the normal loop depth, but limited by a region.
 193
 194    Example:
 195
 196    loop_0
 197      loop_1
 198        {
 199          S0
 200             <- region start
 201          S1
 202
 203          loop_2
 204            S2
 205
 206          S3
 207             <- region end
 208        }
 209
 210     loop_0 does not exist in the region -> invalid
 211     loop_1 exists, but is not completely contained in the region -> depth 0
 212     loop_2 is completely contained -> depth 1  */
 213
 214 static inline unsigned int
 215 sese_loop_depth (const sese_l &region, loop_p loop)
 216 {
 217   unsigned int depth = 0;
 218
 219   while (loop_in_sese_p (loop, region))
 220     {
 221       depth++;
 222       loop = loop_outer (loop);
 223     }
 224
 225   return depth;
 226 }
 227
 228 /* A single entry single exit specialized for conditions.  */
 229
 230 typedef struct ifsese_s {
 231   sese_info_p region;
 232   sese_info_p true_region;
 233   sese_info_p false_region;
 234 } *ifsese;
 235
 236 extern void if_region_set_false_region (ifsese, sese_info_p);
 237 extern ifsese move_sese_in_condition (sese_info_p);
 238 extern void set_ifsese_condition (ifsese, tree);
 239 extern edge get_true_edge_from_guard_bb (basic_block);
 240 extern edge get_false_edge_from_guard_bb (basic_block);
 241
 242 static inline edge
 243 if_region_entry (ifsese if_region)
 244 {
 245   return if_region->region->region.entry;
 246 }
 247
 248 static inline edge
 249 if_region_exit (ifsese if_region)
 250 {
 251   return if_region->region->region.exit;
 252 }
 253
 254 static inline basic_block
 255 if_region_get_condition_block (ifsese if_region)
 256 {
 257   return if_region_entry (if_region)->dest;
 258 }
 259
 260 /* Free and compute again all the dominators information.  */
 261
 262 static inline void
 263 recompute_all_dominators (void)
 264 {
 265   mark_irreducible_loops ();
 266   free_dominance_info (CDI_DOMINATORS);
 267   calculate_dominance_info (CDI_DOMINATORS);
 268
 269   free_dominance_info (CDI_POST_DOMINATORS);
 270   calculate_dominance_info (CDI_POST_DOMINATORS);
 271 }
 272
 273 typedef std::pair <gimple *, tree> scalar_use;
 274
 275 typedef struct gimple_poly_bb
 276 {
 277   basic_block bb;
 278   struct poly_bb *pbb;
 279
 280   /* Lists containing the restrictions of the conditional statements
 281      dominating this bb.  This bb can only be executed, if all conditions
 282      are true.
 283
 284      Example:
 285
 286      for (i = 0; i <= 20; i++)
 287      {
 288        A
 289
 290        if (2i <= 8)
 291          B
 292      }
 293
 294      So for B there is an additional condition (2i <= 8).
 295
 296      List of COND_EXPR and SWITCH_EXPR.  A COND_EXPR is true only if the
 297      corresponding element in CONDITION_CASES is not NULL_TREE.  For a
 298      SWITCH_EXPR the corresponding element in CONDITION_CASES is a
 299      CASE_LABEL_EXPR.  */
 300   vec<gimple *> conditions;
 301   vec<gimple *> condition_cases;
 302   vec<data_reference_p> data_refs;
 303   vec<scalar_use> read_scalar_refs;
 304   vec<tree> write_scalar_refs;
 305 } *gimple_poly_bb_p;
 306
 307 #define GBB_BB(GBB) (GBB)->bb
 308 #define GBB_PBB(GBB) (GBB)->pbb
 309 #define GBB_DATA_REFS(GBB) (GBB)->data_refs
 310 #define GBB_CONDITIONS(GBB) (GBB)->conditions
 311 #define GBB_CONDITION_CASES(GBB) (GBB)->condition_cases
 312
 313 /* Return the innermost loop that contains the basic block GBB.  */
 314
 315 static inline struct loop *
 316 gbb_loop (gimple_poly_bb_p gbb)
 317 {
 318   return GBB_BB (gbb)->loop_father;
 319 }
 320
 321 /* Returns the gimple loop, that corresponds to the loop_iterator_INDEX.
 322    If there is no corresponding gimple loop, we return NULL.  */
 323
 324 static inline loop_p
 325 gbb_loop_at_index (gimple_poly_bb_p gbb, sese_l &region, int index)
 326 {
 327   loop_p loop = gbb_loop (gbb);
 328   int depth = sese_loop_depth (region, loop);
 329
 330   while (--depth > index)
 331     loop = loop_outer (loop);
 332
 333   gcc_assert (loop_in_sese_p (loop, region));
 334
 335   return loop;
 336 }
 337
 338 /* The number of common loops in REGION for GBB1 and GBB2.  */
 339
 340 static inline int
 341 nb_common_loops (sese_l &region, gimple_poly_bb_p gbb1, gimple_poly_bb_p gbb2)
 342 {
 343   loop_p l1 = gbb_loop (gbb1);
 344   loop_p l2 = gbb_loop (gbb2);
 345   loop_p common = find_common_loop (l1, l2);
 346
 347   return sese_loop_depth (region, common);
 348 }
 349
 350 #endif