1 /* Single entry single exit control flow regions. 2 Copyright (C) 2008-2015 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> params; 34 35 /* Loops completely contained in the SCOP. */ 36 bitmap loops; 37 vec<loop_p> loop_nest; 38 39 /* Are we allowed to add more params? This is for debugging purpose. We 40 can only add new params before generating the bb domains, otherwise they 41 become invalid. */ 42 bool add_params; 43 } *sese; 44 45 #define SESE_ENTRY(S) (S->entry) 46 #define SESE_ENTRY_BB(S) (S->entry->dest) 47 #define SESE_EXIT(S) (S->exit) 48 #define SESE_EXIT_BB(S) (S->exit->dest) 49 #define SESE_PARAMS(S) (S->params) 50 #define SESE_LOOPS(S) (S->loops) 51 #define SESE_LOOP_NEST(S) (S->loop_nest) 52 #define SESE_ADD_PARAMS(S) (S->add_params) 53 54 extern sese new_sese (edge, edge); 55 extern void free_sese (sese); 56 extern void sese_insert_phis_for_liveouts (sese, basic_block, edge, edge); 57 extern void build_sese_loop_nests (sese); 58 extern edge copy_bb_and_scalar_dependences (basic_block, sese, edge, 59 vec<tree> , bool *); 60 extern struct loop *outermost_loop_in_sese (sese, basic_block); 61 extern tree scalar_evolution_in_region (sese, loop_p, tree); 62 63 /* Check that SESE contains LOOP. */ 64 65 static inline bool 66 sese_contains_loop (sese sese, struct loop *loop) 67 { 68 return bitmap_bit_p (SESE_LOOPS (sese), loop->num); 69 } 70 71 /* The number of parameters in REGION. */ 72 73 static inline unsigned 74 sese_nb_params (sese region) 75 { 76 return SESE_PARAMS (region).length (); 77 } 78 79 /* Checks whether BB is contained in the region delimited by ENTRY and 80 EXIT blocks. */ 81 82 static inline bool 83 bb_in_region (basic_block bb, basic_block entry, basic_block exit) 84 { 85 #ifdef ENABLE_CHECKING 86 { 87 edge e; 88 edge_iterator ei; 89 90 /* Check that there are no edges coming in the region: all the 91 predecessors of EXIT are dominated by ENTRY. */ 92 FOR_EACH_EDGE (e, ei, exit->preds) 93 dominated_by_p (CDI_DOMINATORS, e->src, entry); 94 } 95 #endif 96 97 return dominated_by_p (CDI_DOMINATORS, bb, entry) 98 && !(dominated_by_p (CDI_DOMINATORS, bb, exit) 99 && !dominated_by_p (CDI_DOMINATORS, entry, exit)); 100 } 101 102 /* Checks whether BB is contained in the region delimited by ENTRY and 103 EXIT blocks. */ 104 105 static inline bool 106 bb_in_sese_p (basic_block bb, sese region) 107 { 108 basic_block entry = SESE_ENTRY_BB (region); 109 basic_block exit = SESE_EXIT_BB (region); 110 111 return bb_in_region (bb, entry, exit); 112 } 113 114 /* Returns true when STMT is defined in REGION. */ 115 116 static inline bool 117 stmt_in_sese_p (gimple stmt, sese region) 118 { 119 basic_block bb = gimple_bb (stmt); 120 return bb && bb_in_sese_p (bb, region); 121 } 122 123 /* Returns true when NAME is defined in REGION. */ 124 125 static inline bool 126 defined_in_sese_p (tree name, sese region) 127 { 128 gimple stmt = SSA_NAME_DEF_STMT (name); 129 return stmt_in_sese_p (stmt, region); 130 } 131 132 /* Returns true when LOOP is in REGION. */ 133 134 static inline bool 135 loop_in_sese_p (struct loop *loop, sese region) 136 { 137 return (bb_in_sese_p (loop->header, region) 138 && bb_in_sese_p (loop->latch, region)); 139 } 140 141 /* Returns the loop depth of LOOP in REGION. The loop depth 142 is the same as the normal loop depth, but limited by a region. 143 144 Example: 145 146 loop_0 147 loop_1 148 { 149 S0 150 <- region start 151 S1 152 153 loop_2 154 S2 155 156 S3 157 <- region end 158 } 159 160 loop_0 does not exist in the region -> invalid 161 loop_1 exists, but is not completely contained in the region -> depth 0 162 loop_2 is completely contained -> depth 1 */ 163 164 static inline unsigned int 165 sese_loop_depth (sese region, loop_p loop) 166 { 167 unsigned int depth = 0; 168 169 gcc_assert ((!loop_in_sese_p (loop, region) 170 && (SESE_ENTRY_BB (region)->loop_father == loop 171 || SESE_EXIT (region)->src->loop_father == loop)) 172 || loop_in_sese_p (loop, region)); 173 174 while (loop_in_sese_p (loop, region)) 175 { 176 depth++; 177 loop = loop_outer (loop); 178 } 179 180 return depth; 181 } 182 183 /* Splits BB to make a single entry single exit region. */ 184 185 static inline sese 186 split_region_for_bb (basic_block bb) 187 { 188 edge entry, exit; 189 190 if (single_pred_p (bb)) 191 entry = single_pred_edge (bb); 192 else 193 { 194 entry = split_block_after_labels (bb); 195 bb = single_succ (bb); 196 } 197 198 if (single_succ_p (bb)) 199 exit = single_succ_edge (bb); 200 else 201 { 202 gimple_stmt_iterator gsi = gsi_last_bb (bb); 203 gsi_prev (&gsi); 204 exit = split_block (bb, gsi_stmt (gsi)); 205 } 206 207 return new_sese (entry, exit); 208 } 209 210 /* Returns the block preceding the entry of a SESE. */ 211 212 static inline basic_block 213 block_before_sese (sese sese) 214 { 215 return SESE_ENTRY (sese)->src; 216 } 217 218 219 220 /* A single entry single exit specialized for conditions. */ 221 222 typedef struct ifsese_s { 223 sese region; 224 sese true_region; 225 sese false_region; 226 } *ifsese; 227 228 extern void if_region_set_false_region (ifsese, sese); 229 extern ifsese move_sese_in_condition (sese); 230 extern edge get_true_edge_from_guard_bb (basic_block); 231 extern edge get_false_edge_from_guard_bb (basic_block); 232 extern void set_ifsese_condition (ifsese, tree); 233 234 static inline edge 235 if_region_entry (ifsese if_region) 236 { 237 return SESE_ENTRY (if_region->region); 238 } 239 240 static inline edge 241 if_region_exit (ifsese if_region) 242 { 243 return SESE_EXIT (if_region->region); 244 } 245 246 static inline basic_block 247 if_region_get_condition_block (ifsese if_region) 248 { 249 return if_region_entry (if_region)->dest; 250 } 251 252 /* Free and compute again all the dominators information. */ 253 254 static inline void 255 recompute_all_dominators (void) 256 { 257 mark_irreducible_loops (); 258 free_dominance_info (CDI_DOMINATORS); 259 calculate_dominance_info (CDI_DOMINATORS); 260 } 261 262 typedef struct gimple_bb 263 { 264 basic_block bb; 265 struct poly_bb *pbb; 266 267 /* Lists containing the restrictions of the conditional statements 268 dominating this bb. This bb can only be executed, if all conditions 269 are true. 270 271 Example: 272 273 for (i = 0; i <= 20; i++) 274 { 275 A 276 277 if (2i <= 8) 278 B 279 } 280 281 So for B there is an additional condition (2i <= 8). 282 283 List of COND_EXPR and SWITCH_EXPR. A COND_EXPR is true only if the 284 corresponding element in CONDITION_CASES is not NULL_TREE. For a 285 SWITCH_EXPR the corresponding element in CONDITION_CASES is a 286 CASE_LABEL_EXPR. */ 287 vec<gimple> conditions; 288 vec<gimple> condition_cases; 289 vec<data_reference_p> data_refs; 290 } *gimple_bb_p; 291 292 #define GBB_BB(GBB) (GBB)->bb 293 #define GBB_PBB(GBB) (GBB)->pbb 294 #define GBB_DATA_REFS(GBB) (GBB)->data_refs 295 #define GBB_CONDITIONS(GBB) (GBB)->conditions 296 #define GBB_CONDITION_CASES(GBB) (GBB)->condition_cases 297 298 /* Return the innermost loop that contains the basic block GBB. */ 299 300 static inline struct loop * 301 gbb_loop (struct gimple_bb *gbb) 302 { 303 return GBB_BB (gbb)->loop_father; 304 } 305 306 /* Returns the gimple loop, that corresponds to the loop_iterator_INDEX. 307 If there is no corresponding gimple loop, we return NULL. */ 308 309 static inline loop_p 310 gbb_loop_at_index (gimple_bb_p gbb, sese region, int index) 311 { 312 loop_p loop = gbb_loop (gbb); 313 int depth = sese_loop_depth (region, loop); 314 315 while (--depth > index) 316 loop = loop_outer (loop); 317 318 gcc_assert (sese_contains_loop (region, loop)); 319 320 return loop; 321 } 322 323 /* The number of common loops in REGION for GBB1 and GBB2. */ 324 325 static inline int 326 nb_common_loops (sese region, gimple_bb_p gbb1, gimple_bb_p gbb2) 327 { 328 loop_p l1 = gbb_loop (gbb1); 329 loop_p l2 = gbb_loop (gbb2); 330 loop_p common = find_common_loop (l1, l2); 331 332 return sese_loop_depth (region, common); 333 } 334 335 /* Return true when DEF can be analyzed in REGION by the scalar 336 evolution analyzer. */ 337 338 static inline bool 339 scev_analyzable_p (tree def, sese region) 340 { 341 loop_p loop; 342 tree scev; 343 tree type = TREE_TYPE (def); 344 345 /* When Graphite generates code for a scev, the code generator 346 expresses the scev in function of a single induction variable. 347 This is unsafe for floating point computations, as it may replace 348 a floating point sum reduction with a multiplication. The 349 following test returns false for non integer types to avoid such 350 problems. */ 351 if (!INTEGRAL_TYPE_P (type) 352 && !POINTER_TYPE_P (type)) 353 return false; 354 355 loop = loop_containing_stmt (SSA_NAME_DEF_STMT (def)); 356 scev = scalar_evolution_in_region (region, loop, def); 357 358 return !chrec_contains_undetermined (scev) 359 && (TREE_CODE (scev) != SSA_NAME 360 || !defined_in_sese_p (scev, region)) 361 && (tree_does_not_contain_chrecs (scev) 362 || evolution_function_is_affine_p (scev)); 363 } 364 365 #endif 366