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annotate gcc/tree-ssa-phiprop.c @ 158:494b0b89df80 default tip
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| author | Shinji KONO <kono@ie.u-ryukyu.ac.jp> |
|---|---|
| date | Mon, 25 May 2020 18:13:55 +0900 |
| parents | 1830386684a0 |
| children |
| rev | line source |
|---|---|
| 0 | 1 /* Backward propagation of indirect loads through PHIs. |
| 145 | 2 Copyright (C) 2007-2020 Free Software Foundation, Inc. |
| 0 | 3 Contributed by Richard Guenther <rguenther@suse.de> |
| 4 | |
| 5 This file is part of GCC. | |
| 6 | |
| 7 GCC is free software; you can redistribute it and/or modify | |
| 8 it under the terms of the GNU General Public License as published by | |
| 9 the Free Software Foundation; either version 3, or (at your option) | |
| 10 any later version. | |
| 11 | |
| 12 GCC is distributed in the hope that it will be useful, | |
| 13 but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 15 GNU General Public License for more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License | |
| 18 along with GCC; see the file COPYING3. If not see | |
| 19 <http://www.gnu.org/licenses/>. */ | |
| 20 | |
| 21 #include "config.h" | |
| 22 #include "system.h" | |
| 23 #include "coretypes.h" | |
| 111 | 24 #include "backend.h" |
| 0 | 25 #include "tree.h" |
| 111 | 26 #include "gimple.h" |
| 27 #include "tree-pass.h" | |
| 28 #include "ssa.h" | |
|
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29 #include "gimple-pretty-print.h" |
| 111 | 30 #include "fold-const.h" |
| 31 #include "tree-eh.h" | |
| 32 #include "gimplify.h" | |
| 33 #include "gimple-iterator.h" | |
| 34 #include "stor-layout.h" | |
| 35 #include "tree-ssa-loop.h" | |
| 0 | 36 |
| 37 /* This pass propagates indirect loads through the PHI node for its | |
| 38 address to make the load source possibly non-addressable and to | |
| 39 allow for PHI optimization to trigger. | |
| 40 | |
| 41 For example the pass changes | |
| 42 | |
| 43 # addr_1 = PHI <&a, &b> | |
| 44 tmp_1 = *addr_1; | |
| 45 | |
| 46 to | |
| 47 | |
| 48 # tmp_1 = PHI <a, b> | |
| 49 | |
| 50 but also handles more complex scenarios like | |
| 51 | |
| 52 D.2077_2 = &this_1(D)->a1; | |
| 53 ... | |
| 54 | |
| 55 # b_12 = PHI <&c(2), D.2077_2(3)> | |
| 56 D.2114_13 = *b_12; | |
| 57 ... | |
| 58 | |
| 59 # b_15 = PHI <b_12(4), &b(5)> | |
| 60 D.2080_5 = &this_1(D)->a0; | |
| 61 ... | |
| 62 | |
| 63 # b_18 = PHI <D.2080_5(6), &c(7)> | |
| 64 ... | |
| 65 | |
| 66 # b_21 = PHI <b_15(8), b_18(9)> | |
| 67 D.2076_8 = *b_21; | |
| 68 | |
| 69 where the addresses loaded are defined by PHIs itself. | |
| 70 The above happens for | |
| 71 | |
| 72 std::max(std::min(a0, c), std::min(std::max(a1, c), b)) | |
| 73 | |
| 74 where this pass transforms it to a form later PHI optimization | |
| 75 recognizes and transforms it to the simple | |
| 76 | |
| 77 D.2109_10 = this_1(D)->a1; | |
| 78 D.2110_11 = c; | |
| 79 D.2114_31 = MAX_EXPR <D.2109_10, D.2110_11>; | |
| 80 D.2115_14 = b; | |
| 81 D.2125_17 = MIN_EXPR <D.2115_14, D.2114_31>; | |
| 82 D.2119_16 = this_1(D)->a0; | |
| 83 D.2124_32 = MIN_EXPR <D.2110_11, D.2119_16>; | |
| 84 D.2076_33 = MAX_EXPR <D.2125_17, D.2124_32>; | |
| 85 | |
| 86 The pass does a dominator walk processing loads using a basic-block | |
| 87 local analysis and stores the result for use by transformations on | |
| 88 dominated basic-blocks. */ | |
| 89 | |
| 90 | |
| 91 /* Structure to keep track of the value of a dereferenced PHI result | |
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92 and the virtual operand used for that dereference. */ |
| 0 | 93 |
| 94 struct phiprop_d | |
| 95 { | |
| 96 tree value; | |
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97 tree vuse; |
| 0 | 98 }; |
| 99 | |
| 100 /* Verify if the value recorded for NAME in PHIVN is still valid at | |
| 101 the start of basic block BB. */ | |
| 102 | |
| 103 static bool | |
| 104 phivn_valid_p (struct phiprop_d *phivn, tree name, basic_block bb) | |
| 105 { | |
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106 tree vuse = phivn[SSA_NAME_VERSION (name)].vuse; |
| 111 | 107 gimple *use_stmt; |
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108 imm_use_iterator ui2; |
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109 bool ok = true; |
| 0 | 110 |
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111 /* The def stmts of the virtual uses need to be dominated by bb. */ |
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112 gcc_assert (vuse != NULL_TREE); |
| 0 | 113 |
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114 FOR_EACH_IMM_USE_STMT (use_stmt, ui2, vuse) |
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115 { |
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116 /* If BB does not dominate a VDEF, the value is invalid. */ |
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117 if ((gimple_vdef (use_stmt) != NULL_TREE |
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118 || gimple_code (use_stmt) == GIMPLE_PHI) |
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119 && !dominated_by_p (CDI_DOMINATORS, gimple_bb (use_stmt), bb)) |
| 0 | 120 { |
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121 ok = false; |
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122 BREAK_FROM_IMM_USE_STMT (ui2); |
| 0 | 123 } |
| 124 } | |
| 125 | |
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126 return ok; |
| 0 | 127 } |
| 128 | |
| 129 /* Insert a new phi node for the dereference of PHI at basic_block | |
| 130 BB with the virtual operands from USE_STMT. */ | |
| 131 | |
| 132 static tree | |
| 111 | 133 phiprop_insert_phi (basic_block bb, gphi *phi, gimple *use_stmt, |
| 0 | 134 struct phiprop_d *phivn, size_t n) |
| 135 { | |
| 136 tree res; | |
| 111 | 137 gphi *new_phi = NULL; |
| 0 | 138 edge_iterator ei; |
| 139 edge e; | |
| 140 | |
| 141 gcc_assert (is_gimple_assign (use_stmt) | |
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142 && gimple_assign_rhs_code (use_stmt) == MEM_REF); |
| 0 | 143 |
| 144 /* Build a new PHI node to replace the definition of | |
| 145 the indirect reference lhs. */ | |
| 146 res = gimple_assign_lhs (use_stmt); | |
| 111 | 147 if (TREE_CODE (res) == SSA_NAME) |
| 148 new_phi = create_phi_node (res, bb); | |
| 0 | 149 |
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150 if (dump_file && (dump_flags & TDF_DETAILS)) |
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151 { |
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152 fprintf (dump_file, "Inserting PHI for result of load "); |
| 111 | 153 print_gimple_stmt (dump_file, use_stmt, 0); |
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154 } |
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155 |
| 0 | 156 /* Add PHI arguments for each edge inserting loads of the |
| 157 addressable operands. */ | |
| 158 FOR_EACH_EDGE (e, ei, bb->preds) | |
| 159 { | |
| 160 tree old_arg, new_var; | |
| 111 | 161 gassign *tmp; |
| 145 | 162 location_t locus; |
| 0 | 163 |
| 164 old_arg = PHI_ARG_DEF_FROM_EDGE (phi, e); | |
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165 locus = gimple_phi_arg_location_from_edge (phi, e); |
| 0 | 166 while (TREE_CODE (old_arg) == SSA_NAME |
| 167 && (SSA_NAME_VERSION (old_arg) >= n | |
| 168 || phivn[SSA_NAME_VERSION (old_arg)].value == NULL_TREE)) | |
| 169 { | |
| 111 | 170 gimple *def_stmt = SSA_NAME_DEF_STMT (old_arg); |
| 0 | 171 old_arg = gimple_assign_rhs1 (def_stmt); |
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172 locus = gimple_location (def_stmt); |
| 0 | 173 } |
| 174 | |
| 175 if (TREE_CODE (old_arg) == SSA_NAME) | |
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176 { |
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177 if (dump_file && (dump_flags & TDF_DETAILS)) |
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178 { |
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179 fprintf (dump_file, " for edge defining "); |
| 111 | 180 print_generic_expr (dump_file, PHI_ARG_DEF_FROM_EDGE (phi, e)); |
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181 fprintf (dump_file, " reusing PHI result "); |
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182 print_generic_expr (dump_file, |
| 111 | 183 phivn[SSA_NAME_VERSION (old_arg)].value); |
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184 fprintf (dump_file, "\n"); |
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185 } |
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186 /* Reuse a formerly created dereference. */ |
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187 new_var = phivn[SSA_NAME_VERSION (old_arg)].value; |
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188 } |
| 0 | 189 else |
| 190 { | |
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191 tree rhs = gimple_assign_rhs1 (use_stmt); |
| 0 | 192 gcc_assert (TREE_CODE (old_arg) == ADDR_EXPR); |
| 111 | 193 if (TREE_CODE (res) == SSA_NAME) |
| 194 new_var = make_ssa_name (TREE_TYPE (rhs)); | |
| 195 else | |
| 196 new_var = unshare_expr (res); | |
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197 if (!is_gimple_min_invariant (old_arg)) |
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198 old_arg = PHI_ARG_DEF_FROM_EDGE (phi, e); |
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199 else |
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200 old_arg = unshare_expr (old_arg); |
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201 tmp = gimple_build_assign (new_var, |
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202 fold_build2 (MEM_REF, TREE_TYPE (rhs), |
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203 old_arg, |
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204 TREE_OPERAND (rhs, 1))); |
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205 gimple_set_location (tmp, locus); |
| 0 | 206 |
| 207 gsi_insert_on_edge (e, tmp); | |
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208 update_stmt (tmp); |
| 0 | 209 |
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210 if (dump_file && (dump_flags & TDF_DETAILS)) |
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211 { |
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212 fprintf (dump_file, " for edge defining "); |
| 111 | 213 print_generic_expr (dump_file, PHI_ARG_DEF_FROM_EDGE (phi, e)); |
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214 fprintf (dump_file, " inserting load "); |
| 111 | 215 print_gimple_stmt (dump_file, tmp, 0); |
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216 } |
| 0 | 217 } |
| 218 | |
| 111 | 219 if (new_phi) |
| 220 add_phi_arg (new_phi, new_var, e, locus); | |
| 221 } | |
| 222 | |
| 223 if (new_phi) | |
| 224 { | |
| 225 update_stmt (new_phi); | |
| 226 | |
| 227 if (dump_file && (dump_flags & TDF_DETAILS)) | |
| 228 print_gimple_stmt (dump_file, new_phi, 0); | |
| 0 | 229 } |
| 230 | |
| 111 | 231 return res; |
| 232 } | |
| 233 | |
| 234 /* Verify if *idx is available at *DATA. */ | |
| 0 | 235 |
| 111 | 236 static bool |
| 237 chk_uses (tree, tree *idx, void *data) | |
| 238 { | |
| 239 basic_block dom = (basic_block) data; | |
| 240 if (TREE_CODE (*idx) == SSA_NAME) | |
| 241 return (SSA_NAME_IS_DEFAULT_DEF (*idx) | |
| 242 || ! dominated_by_p (CDI_DOMINATORS, | |
| 243 gimple_bb (SSA_NAME_DEF_STMT (*idx)), dom)); | |
| 244 return true; | |
| 0 | 245 } |
| 246 | |
| 247 /* Propagate between the phi node arguments of PHI in BB and phi result | |
| 248 users. For now this matches | |
| 249 # p_2 = PHI <&x, &y> | |
| 250 <Lx>:; | |
| 251 p_3 = p_2; | |
| 252 z_2 = *p_3; | |
| 253 and converts it to | |
| 254 # z_2 = PHI <x, y> | |
| 255 <Lx>:; | |
| 256 Returns true if a transformation was done and edge insertions | |
| 257 need to be committed. Global data PHIVN and N is used to track | |
| 258 past transformation results. We need to be especially careful here | |
| 259 with aliasing issues as we are moving memory reads. */ | |
| 260 | |
| 261 static bool | |
| 111 | 262 propagate_with_phi (basic_block bb, gphi *phi, struct phiprop_d *phivn, |
| 0 | 263 size_t n) |
| 264 { | |
| 265 tree ptr = PHI_RESULT (phi); | |
| 111 | 266 gimple *use_stmt; |
| 0 | 267 tree res = NULL_TREE; |
| 268 gimple_stmt_iterator gsi; | |
| 269 imm_use_iterator ui; | |
| 270 use_operand_p arg_p, use; | |
| 271 ssa_op_iter i; | |
| 272 bool phi_inserted; | |
| 131 | 273 bool changed; |
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274 tree type = NULL_TREE; |
| 0 | 275 |
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276 if (!POINTER_TYPE_P (TREE_TYPE (ptr)) |
| 111 | 277 || (!is_gimple_reg_type (TREE_TYPE (TREE_TYPE (ptr))) |
| 278 && TYPE_MODE (TREE_TYPE (TREE_TYPE (ptr))) == BLKmode)) | |
| 0 | 279 return false; |
| 280 | |
| 281 /* Check if we can "cheaply" dereference all phi arguments. */ | |
| 282 FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_USE) | |
| 283 { | |
| 284 tree arg = USE_FROM_PTR (arg_p); | |
| 285 /* Walk the ssa chain until we reach a ssa name we already | |
| 286 created a value for or we reach a definition of the form | |
| 287 ssa_name_n = &var; */ | |
| 288 while (TREE_CODE (arg) == SSA_NAME | |
| 289 && !SSA_NAME_IS_DEFAULT_DEF (arg) | |
| 290 && (SSA_NAME_VERSION (arg) >= n | |
| 291 || phivn[SSA_NAME_VERSION (arg)].value == NULL_TREE)) | |
| 292 { | |
| 111 | 293 gimple *def_stmt = SSA_NAME_DEF_STMT (arg); |
| 0 | 294 if (!gimple_assign_single_p (def_stmt)) |
| 295 return false; | |
| 296 arg = gimple_assign_rhs1 (def_stmt); | |
| 297 } | |
|
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298 if (TREE_CODE (arg) != ADDR_EXPR |
| 0 | 299 && !(TREE_CODE (arg) == SSA_NAME |
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300 && SSA_NAME_VERSION (arg) < n |
| 0 | 301 && phivn[SSA_NAME_VERSION (arg)].value != NULL_TREE |
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302 && (!type |
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303 || types_compatible_p |
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304 (type, TREE_TYPE (phivn[SSA_NAME_VERSION (arg)].value))) |
| 0 | 305 && phivn_valid_p (phivn, arg, bb))) |
| 306 return false; | |
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307 if (!type |
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308 && TREE_CODE (arg) == SSA_NAME) |
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309 type = TREE_TYPE (phivn[SSA_NAME_VERSION (arg)].value); |
| 0 | 310 } |
| 311 | |
| 312 /* Find a dereferencing use. First follow (single use) ssa | |
| 313 copy chains for ptr. */ | |
| 314 while (single_imm_use (ptr, &use, &use_stmt) | |
| 315 && gimple_assign_ssa_name_copy_p (use_stmt)) | |
| 316 ptr = gimple_assign_lhs (use_stmt); | |
| 317 | |
| 318 /* Replace the first dereference of *ptr if there is one and if we | |
| 319 can move the loads to the place of the ptr phi node. */ | |
| 320 phi_inserted = false; | |
| 131 | 321 changed = false; |
| 0 | 322 FOR_EACH_IMM_USE_STMT (use_stmt, ui, ptr) |
| 323 { | |
| 111 | 324 gimple *def_stmt; |
| 0 | 325 tree vuse; |
| 326 | |
| 111 | 327 /* Only replace loads in blocks that post-dominate the PHI node. That |
| 328 makes sure we don't end up speculating loads. */ | |
| 329 if (!dominated_by_p (CDI_POST_DOMINATORS, | |
| 330 bb, gimple_bb (use_stmt))) | |
| 331 continue; | |
| 332 | |
| 0 | 333 /* Check whether this is a load of *ptr. */ |
| 334 if (!(is_gimple_assign (use_stmt) | |
|
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335 && gimple_assign_rhs_code (use_stmt) == MEM_REF |
| 0 | 336 && TREE_OPERAND (gimple_assign_rhs1 (use_stmt), 0) == ptr |
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337 && integer_zerop (TREE_OPERAND (gimple_assign_rhs1 (use_stmt), 1)) |
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338 && (!type |
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339 || types_compatible_p |
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340 (TREE_TYPE (gimple_assign_lhs (use_stmt)), type)) |
| 145 | 341 /* We cannot replace a load that may throw or is volatile. |
| 342 For volatiles the transform can change the number of | |
| 343 executions if the load is inside a loop but the address | |
| 344 computations outside (PR91812). We could relax this | |
| 345 if we guard against that appropriately. For loads that can | |
| 346 throw we could relax things if the moved loads all are | |
| 347 known to not throw. */ | |
| 348 && !stmt_can_throw_internal (cfun, use_stmt) | |
| 349 && !gimple_has_volatile_ops (use_stmt))) | |
| 0 | 350 continue; |
| 351 | |
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352 /* Check if we can move the loads. The def stmt of the virtual use |
| 111 | 353 needs to be in a different basic block dominating bb. When the |
| 354 def is an edge-inserted one we know it dominates us. */ | |
|
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355 vuse = gimple_vuse (use_stmt); |
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356 def_stmt = SSA_NAME_DEF_STMT (vuse); |
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357 if (!SSA_NAME_IS_DEFAULT_DEF (vuse) |
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358 && (gimple_bb (def_stmt) == bb |
| 111 | 359 || (gimple_bb (def_stmt) |
| 360 && !dominated_by_p (CDI_DOMINATORS, | |
| 361 bb, gimple_bb (def_stmt))))) | |
|
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362 goto next; |
| 0 | 363 |
| 111 | 364 /* Found a proper dereference with an aggregate copy. Just |
| 365 insert aggregate copies on the edges instead. */ | |
| 131 | 366 if (!is_gimple_reg_type (TREE_TYPE (gimple_assign_lhs (use_stmt)))) |
| 111 | 367 { |
| 368 if (!gimple_vdef (use_stmt)) | |
| 369 goto next; | |
| 370 | |
| 371 /* As we replicate the lhs on each incoming edge all | |
| 372 used SSA names have to be available there. */ | |
| 373 if (! for_each_index (gimple_assign_lhs_ptr (use_stmt), | |
| 374 chk_uses, | |
| 375 get_immediate_dominator (CDI_DOMINATORS, | |
| 376 gimple_bb (phi)))) | |
| 377 goto next; | |
| 378 | |
| 379 gimple *vuse_stmt; | |
| 380 imm_use_iterator vui; | |
| 381 use_operand_p vuse_p; | |
| 382 /* In order to move the aggregate copies earlier, make sure | |
| 383 there are no statements that could read from memory | |
| 384 aliasing the lhs in between the start of bb and use_stmt. | |
| 385 As we require use_stmt to have a VDEF above, loads after | |
| 386 use_stmt will use a different virtual SSA_NAME. */ | |
| 387 FOR_EACH_IMM_USE_FAST (vuse_p, vui, vuse) | |
| 388 { | |
| 389 vuse_stmt = USE_STMT (vuse_p); | |
| 390 if (vuse_stmt == use_stmt) | |
| 391 continue; | |
| 392 if (!dominated_by_p (CDI_DOMINATORS, | |
| 393 gimple_bb (vuse_stmt), bb)) | |
| 394 continue; | |
| 395 if (ref_maybe_used_by_stmt_p (vuse_stmt, | |
| 396 gimple_assign_lhs (use_stmt))) | |
| 397 goto next; | |
| 398 } | |
| 399 | |
| 400 phiprop_insert_phi (bb, phi, use_stmt, phivn, n); | |
| 401 | |
| 402 /* Remove old stmt. The phi is taken care of by DCE. */ | |
| 403 gsi = gsi_for_stmt (use_stmt); | |
| 404 /* Unlinking the VDEF here is fine as we are sure that we process | |
| 405 stmts in execution order due to aggregate copies having VDEFs | |
| 406 and we emit loads on the edges in the very same order. | |
| 407 We get multiple copies (or intermediate register loads) handled | |
| 408 only by walking PHIs or immediate uses in a lucky order though, | |
| 409 so we could signal the caller to re-start iterating over PHIs | |
| 410 when we come here which would make it quadratic in the number | |
| 411 of PHIs. */ | |
| 412 unlink_stmt_vdef (use_stmt); | |
| 413 gsi_remove (&gsi, true); | |
| 414 | |
| 131 | 415 changed = true; |
| 111 | 416 } |
| 417 | |
| 0 | 418 /* Found a proper dereference. Insert a phi node if this |
| 419 is the first load transformation. */ | |
| 111 | 420 else if (!phi_inserted) |
| 0 | 421 { |
| 422 res = phiprop_insert_phi (bb, phi, use_stmt, phivn, n); | |
|
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423 type = TREE_TYPE (res); |
| 0 | 424 |
| 425 /* Remember the value we created for *ptr. */ | |
| 426 phivn[SSA_NAME_VERSION (ptr)].value = res; | |
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427 phivn[SSA_NAME_VERSION (ptr)].vuse = vuse; |
| 0 | 428 |
| 429 /* Remove old stmt. The phi is taken care of by DCE, if we | |
| 430 want to delete it here we also have to delete all intermediate | |
| 431 copies. */ | |
| 432 gsi = gsi_for_stmt (use_stmt); | |
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433 gsi_remove (&gsi, true); |
| 0 | 434 |
| 435 phi_inserted = true; | |
| 131 | 436 changed = true; |
| 0 | 437 } |
| 438 else | |
| 439 { | |
| 440 /* Further replacements are easy, just make a copy out of the | |
| 441 load. */ | |
| 442 gimple_assign_set_rhs1 (use_stmt, res); | |
| 443 update_stmt (use_stmt); | |
| 131 | 444 changed = true; |
| 0 | 445 } |
| 446 | |
| 447 next:; | |
| 448 /* Continue searching for a proper dereference. */ | |
| 449 } | |
| 450 | |
| 131 | 451 return changed; |
| 0 | 452 } |
| 453 | |
| 454 /* Main entry for phiprop pass. */ | |
| 455 | |
| 111 | 456 namespace { |
| 457 | |
| 458 const pass_data pass_data_phiprop = | |
| 0 | 459 { |
| 111 | 460 GIMPLE_PASS, /* type */ |
| 461 "phiprop", /* name */ | |
| 462 OPTGROUP_NONE, /* optinfo_flags */ | |
| 463 TV_TREE_PHIPROP, /* tv_id */ | |
| 464 ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
| 465 0, /* properties_provided */ | |
| 466 0, /* properties_destroyed */ | |
| 467 0, /* todo_flags_start */ | |
| 468 TODO_update_ssa, /* todo_flags_finish */ | |
| 469 }; | |
| 470 | |
| 471 class pass_phiprop : public gimple_opt_pass | |
| 472 { | |
| 473 public: | |
| 474 pass_phiprop (gcc::context *ctxt) | |
| 475 : gimple_opt_pass (pass_data_phiprop, ctxt) | |
| 476 {} | |
| 477 | |
| 478 /* opt_pass methods: */ | |
| 479 virtual bool gate (function *) { return flag_tree_phiprop; } | |
| 480 virtual unsigned int execute (function *); | |
| 481 | |
| 482 }; // class pass_phiprop | |
| 483 | |
| 484 unsigned int | |
| 485 pass_phiprop::execute (function *fun) | |
| 486 { | |
| 487 vec<basic_block> bbs; | |
| 0 | 488 struct phiprop_d *phivn; |
|
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489 bool did_something = false; |
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490 basic_block bb; |
| 111 | 491 gphi_iterator gsi; |
|
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492 unsigned i; |
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493 size_t n; |
| 0 | 494 |
| 495 calculate_dominance_info (CDI_DOMINATORS); | |
| 111 | 496 calculate_dominance_info (CDI_POST_DOMINATORS); |
| 0 | 497 |
|
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498 n = num_ssa_names; |
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499 phivn = XCNEWVEC (struct phiprop_d, n); |
| 0 | 500 |
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501 /* Walk the dominator tree in preorder. */ |
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502 bbs = get_all_dominated_blocks (CDI_DOMINATORS, |
| 111 | 503 single_succ (ENTRY_BLOCK_PTR_FOR_FN (fun))); |
| 504 FOR_EACH_VEC_ELT (bbs, i, bb) | |
| 145 | 505 { |
| 506 /* Since we're going to move dereferences across predecessor | |
| 507 edges avoid blocks with abnormal predecessors. */ | |
| 508 if (bb_has_abnormal_pred (bb)) | |
| 509 continue; | |
| 510 for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); gsi_next (&gsi)) | |
| 511 did_something |= propagate_with_phi (bb, gsi.phi (), phivn, n); | |
| 512 } | |
|
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513 |
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514 if (did_something) |
| 0 | 515 gsi_commit_edge_inserts (); |
| 516 | |
| 111 | 517 bbs.release (); |
| 0 | 518 free (phivn); |
| 519 | |
| 111 | 520 free_dominance_info (CDI_POST_DOMINATORS); |
| 521 | |
| 0 | 522 return 0; |
| 523 } | |
| 524 | |
| 111 | 525 } // anon namespace |
| 0 | 526 |
| 111 | 527 gimple_opt_pass * |
| 528 make_pass_phiprop (gcc::context *ctxt) | |
| 0 | 529 { |
| 111 | 530 return new pass_phiprop (ctxt); |
| 531 } |