Mercurial > hg > truffle
annotate src/share/vm/opto/loopPredicate.cpp @ 3840:4e761e7e6e12
7070134: Hotspot crashes with sigsegv from PorterStemmer
Summary: Do not move data nodes which are attached to a predicate test to a dominating test.
Reviewed-by: never
| author | kvn |
|---|---|
| date | Tue, 26 Jul 2011 19:35:23 -0700 |
| parents | bad7ecd0b6ed |
| children | c96c3eb1efae |
| rev | line source |
|---|---|
| 2445 | 1 /* |
| 2 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved. | |
| 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| 4 * | |
| 5 * This code is free software; you can redistribute it and/or modify it | |
| 6 * under the terms of the GNU General Public License version 2 only, as | |
| 7 * published by the Free Software Foundation. | |
| 8 * | |
| 9 * This code is distributed in the hope that it will be useful, but WITHOUT | |
| 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 12 * version 2 for more details (a copy is included in the LICENSE file that | |
| 13 * accompanied this code). | |
| 14 * | |
| 15 * You should have received a copy of the GNU General Public License version | |
| 16 * 2 along with this work; if not, write to the Free Software Foundation, | |
| 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 18 * | |
| 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| 20 * or visit www.oracle.com if you need additional information or have any | |
| 21 * questions. | |
| 22 * | |
| 23 */ | |
| 24 | |
| 25 #include "precompiled.hpp" | |
| 26 #include "opto/loopnode.hpp" | |
| 27 #include "opto/addnode.hpp" | |
| 28 #include "opto/callnode.hpp" | |
| 29 #include "opto/connode.hpp" | |
| 30 #include "opto/loopnode.hpp" | |
| 31 #include "opto/mulnode.hpp" | |
| 32 #include "opto/rootnode.hpp" | |
| 33 #include "opto/subnode.hpp" | |
| 34 | |
| 35 /* | |
| 36 * The general idea of Loop Predication is to insert a predicate on the entry | |
| 37 * path to a loop, and raise a uncommon trap if the check of the condition fails. | |
| 38 * The condition checks are promoted from inside the loop body, and thus | |
| 39 * the checks inside the loop could be eliminated. Currently, loop predication | |
| 40 * optimization has been applied to remove array range check and loop invariant | |
| 41 * checks (such as null checks). | |
| 42 */ | |
| 43 | |
| 44 //-------------------------------is_uncommon_trap_proj---------------------------- | |
| 45 // Return true if proj is the form of "proj->[region->..]call_uct" | |
| 46 bool PhaseIdealLoop::is_uncommon_trap_proj(ProjNode* proj, Deoptimization::DeoptReason reason) { | |
| 47 int path_limit = 10; | |
| 48 assert(proj, "invalid argument"); | |
| 49 Node* out = proj; | |
| 50 for (int ct = 0; ct < path_limit; ct++) { | |
| 51 out = out->unique_ctrl_out(); | |
| 52 if (out == NULL) | |
| 53 return false; | |
| 54 if (out->is_CallStaticJava()) { | |
| 55 int req = out->as_CallStaticJava()->uncommon_trap_request(); | |
| 56 if (req != 0) { | |
| 57 Deoptimization::DeoptReason trap_reason = Deoptimization::trap_request_reason(req); | |
| 58 if (trap_reason == reason || reason == Deoptimization::Reason_none) { | |
| 59 return true; | |
| 60 } | |
| 61 } | |
| 62 return false; // don't do further after call | |
| 63 } | |
| 64 if (out->Opcode() != Op_Region) | |
| 65 return false; | |
| 66 } | |
| 67 return false; | |
| 68 } | |
| 69 | |
| 70 //-------------------------------is_uncommon_trap_if_pattern------------------------- | |
| 71 // Return true for "if(test)-> proj -> ... | |
| 72 // | | |
| 73 // V | |
| 74 // other_proj->[region->..]call_uct" | |
| 75 // | |
| 76 // "must_reason_predicate" means the uct reason must be Reason_predicate | |
| 77 bool PhaseIdealLoop::is_uncommon_trap_if_pattern(ProjNode *proj, Deoptimization::DeoptReason reason) { | |
| 78 Node *in0 = proj->in(0); | |
| 79 if (!in0->is_If()) return false; | |
| 80 // Variation of a dead If node. | |
| 81 if (in0->outcnt() < 2) return false; | |
| 82 IfNode* iff = in0->as_If(); | |
| 83 | |
| 84 // we need "If(Conv2B(Opaque1(...)))" pattern for reason_predicate | |
| 85 if (reason != Deoptimization::Reason_none) { | |
| 86 if (iff->in(1)->Opcode() != Op_Conv2B || | |
| 87 iff->in(1)->in(1)->Opcode() != Op_Opaque1) { | |
| 88 return false; | |
| 89 } | |
| 90 } | |
| 91 | |
| 92 ProjNode* other_proj = iff->proj_out(1-proj->_con)->as_Proj(); | |
| 93 if (is_uncommon_trap_proj(other_proj, reason)) { | |
| 94 assert(reason == Deoptimization::Reason_none || | |
| 95 Compile::current()->is_predicate_opaq(iff->in(1)->in(1)), "should be on the list"); | |
| 96 return true; | |
| 97 } | |
| 98 return false; | |
| 99 } | |
| 100 | |
| 101 //-------------------------------register_control------------------------- | |
| 102 void PhaseIdealLoop::register_control(Node* n, IdealLoopTree *loop, Node* pred) { | |
| 103 assert(n->is_CFG(), "must be control node"); | |
| 104 _igvn.register_new_node_with_optimizer(n); | |
| 105 loop->_body.push(n); | |
| 106 set_loop(n, loop); | |
| 107 // When called from beautify_loops() idom is not constructed yet. | |
| 108 if (_idom != NULL) { | |
| 109 set_idom(n, pred, dom_depth(pred)); | |
| 110 } | |
| 111 } | |
| 112 | |
| 113 //------------------------------create_new_if_for_predicate------------------------ | |
| 114 // create a new if above the uct_if_pattern for the predicate to be promoted. | |
| 115 // | |
| 116 // before after | |
| 117 // ---------- ---------- | |
| 118 // ctrl ctrl | |
| 119 // | | | |
| 120 // | | | |
| 121 // v v | |
| 122 // iff new_iff | |
| 123 // / \ / \ | |
| 124 // / \ / \ | |
| 125 // v v v v | |
| 126 // uncommon_proj cont_proj if_uct if_cont | |
| 127 // \ | | | | | |
| 128 // \ | | | | | |
| 129 // v v v | v | |
| 130 // rgn loop | iff | |
| 131 // | | / \ | |
| 132 // | | / \ | |
| 133 // v | v v | |
| 134 // uncommon_trap | uncommon_proj cont_proj | |
| 135 // \ \ | | | |
| 136 // \ \ | | | |
| 137 // v v v v | |
| 138 // rgn loop | |
| 139 // | | |
| 140 // | | |
| 141 // v | |
| 142 // uncommon_trap | |
| 143 // | |
| 144 // | |
| 145 // We will create a region to guard the uct call if there is no one there. | |
| 146 // The true projecttion (if_cont) of the new_iff is returned. | |
| 147 // This code is also used to clone predicates to clonned loops. | |
| 148 ProjNode* PhaseIdealLoop::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry, | |
| 149 Deoptimization::DeoptReason reason) { | |
| 150 assert(is_uncommon_trap_if_pattern(cont_proj, reason), "must be a uct if pattern!"); | |
| 151 IfNode* iff = cont_proj->in(0)->as_If(); | |
| 152 | |
| 153 ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con); | |
| 154 Node *rgn = uncommon_proj->unique_ctrl_out(); | |
| 155 assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); | |
| 156 | |
| 157 uint proj_index = 1; // region's edge corresponding to uncommon_proj | |
| 158 if (!rgn->is_Region()) { // create a region to guard the call | |
| 159 assert(rgn->is_Call(), "must be call uct"); | |
| 160 CallNode* call = rgn->as_Call(); | |
| 161 IdealLoopTree* loop = get_loop(call); | |
| 162 rgn = new (C, 1) RegionNode(1); | |
| 163 rgn->add_req(uncommon_proj); | |
| 164 register_control(rgn, loop, uncommon_proj); | |
| 165 _igvn.hash_delete(call); | |
| 166 call->set_req(0, rgn); | |
| 167 // When called from beautify_loops() idom is not constructed yet. | |
| 168 if (_idom != NULL) { | |
| 169 set_idom(call, rgn, dom_depth(rgn)); | |
| 170 } | |
| 171 } else { | |
| 172 // Find region's edge corresponding to uncommon_proj | |
| 173 for (; proj_index < rgn->req(); proj_index++) | |
| 174 if (rgn->in(proj_index) == uncommon_proj) break; | |
| 175 assert(proj_index < rgn->req(), "sanity"); | |
| 176 } | |
| 177 | |
| 178 Node* entry = iff->in(0); | |
| 179 if (new_entry != NULL) { | |
| 180 // Clonning the predicate to new location. | |
| 181 entry = new_entry; | |
| 182 } | |
| 183 // Create new_iff | |
| 184 IdealLoopTree* lp = get_loop(entry); | |
| 185 IfNode *new_iff = iff->clone()->as_If(); | |
| 186 new_iff->set_req(0, entry); | |
| 187 register_control(new_iff, lp, entry); | |
| 188 Node *if_cont = new (C, 1) IfTrueNode(new_iff); | |
| 189 Node *if_uct = new (C, 1) IfFalseNode(new_iff); | |
| 190 if (cont_proj->is_IfFalse()) { | |
| 191 // Swap | |
| 192 Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp; | |
| 193 } | |
| 194 register_control(if_cont, lp, new_iff); | |
| 195 register_control(if_uct, get_loop(rgn), new_iff); | |
| 196 | |
| 197 // if_uct to rgn | |
| 198 _igvn.hash_delete(rgn); | |
| 199 rgn->add_req(if_uct); | |
| 200 // When called from beautify_loops() idom is not constructed yet. | |
| 201 if (_idom != NULL) { | |
| 202 Node* ridom = idom(rgn); | |
| 203 Node* nrdom = dom_lca(ridom, new_iff); | |
| 204 set_idom(rgn, nrdom, dom_depth(rgn)); | |
| 205 } | |
| 206 | |
| 207 // If rgn has phis add new edges which has the same | |
| 208 // value as on original uncommon_proj pass. | |
| 209 assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last"); | |
| 210 bool has_phi = false; | |
| 211 for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) { | |
| 212 Node* use = rgn->fast_out(i); | |
| 213 if (use->is_Phi() && use->outcnt() > 0) { | |
| 214 assert(use->in(0) == rgn, ""); | |
| 215 _igvn.hash_delete(use); | |
| 216 use->add_req(use->in(proj_index)); | |
| 217 _igvn._worklist.push(use); | |
| 218 has_phi = true; | |
| 219 } | |
| 220 } | |
| 221 assert(!has_phi || rgn->req() > 3, "no phis when region is created"); | |
| 222 | |
| 223 if (new_entry == NULL) { | |
| 224 // Attach if_cont to iff | |
| 225 _igvn.hash_delete(iff); | |
| 226 iff->set_req(0, if_cont); | |
| 227 if (_idom != NULL) { | |
| 228 set_idom(iff, if_cont, dom_depth(iff)); | |
| 229 } | |
| 230 } | |
| 231 return if_cont->as_Proj(); | |
| 232 } | |
| 233 | |
| 234 //------------------------------create_new_if_for_predicate------------------------ | |
| 235 // Create a new if below new_entry for the predicate to be cloned (IGVN optimization) | |
| 236 ProjNode* PhaseIterGVN::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry, | |
| 237 Deoptimization::DeoptReason reason) { | |
| 238 assert(new_entry != 0, "only used for clone predicate"); | |
| 239 assert(PhaseIdealLoop::is_uncommon_trap_if_pattern(cont_proj, reason), "must be a uct if pattern!"); | |
| 240 IfNode* iff = cont_proj->in(0)->as_If(); | |
| 241 | |
| 242 ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con); | |
| 243 Node *rgn = uncommon_proj->unique_ctrl_out(); | |
| 244 assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); | |
| 245 | |
| 246 uint proj_index = 1; // region's edge corresponding to uncommon_proj | |
| 247 if (!rgn->is_Region()) { // create a region to guard the call | |
| 248 assert(rgn->is_Call(), "must be call uct"); | |
| 249 CallNode* call = rgn->as_Call(); | |
| 250 rgn = new (C, 1) RegionNode(1); | |
| 251 register_new_node_with_optimizer(rgn); | |
| 252 rgn->add_req(uncommon_proj); | |
| 253 hash_delete(call); | |
| 254 call->set_req(0, rgn); | |
| 255 } else { | |
| 256 // Find region's edge corresponding to uncommon_proj | |
| 257 for (; proj_index < rgn->req(); proj_index++) | |
| 258 if (rgn->in(proj_index) == uncommon_proj) break; | |
| 259 assert(proj_index < rgn->req(), "sanity"); | |
| 260 } | |
| 261 | |
| 262 // Create new_iff in new location. | |
| 263 IfNode *new_iff = iff->clone()->as_If(); | |
| 264 new_iff->set_req(0, new_entry); | |
| 265 | |
| 266 register_new_node_with_optimizer(new_iff); | |
| 267 Node *if_cont = new (C, 1) IfTrueNode(new_iff); | |
| 268 Node *if_uct = new (C, 1) IfFalseNode(new_iff); | |
| 269 if (cont_proj->is_IfFalse()) { | |
| 270 // Swap | |
| 271 Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp; | |
| 272 } | |
| 273 register_new_node_with_optimizer(if_cont); | |
| 274 register_new_node_with_optimizer(if_uct); | |
| 275 | |
| 276 // if_uct to rgn | |
| 277 hash_delete(rgn); | |
| 278 rgn->add_req(if_uct); | |
| 279 | |
| 280 // If rgn has phis add corresponding new edges which has the same | |
| 281 // value as on original uncommon_proj pass. | |
| 282 assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last"); | |
| 283 bool has_phi = false; | |
| 284 for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) { | |
| 285 Node* use = rgn->fast_out(i); | |
| 286 if (use->is_Phi() && use->outcnt() > 0) { | |
| 287 hash_delete(use); | |
| 288 use->add_req(use->in(proj_index)); | |
| 289 _worklist.push(use); | |
| 290 has_phi = true; | |
| 291 } | |
| 292 } | |
| 293 assert(!has_phi || rgn->req() > 3, "no phis when region is created"); | |
| 294 | |
| 295 return if_cont->as_Proj(); | |
| 296 } | |
| 297 | |
| 298 //--------------------------clone_predicate----------------------- | |
| 299 ProjNode* PhaseIdealLoop::clone_predicate(ProjNode* predicate_proj, Node* new_entry, | |
| 300 Deoptimization::DeoptReason reason, | |
| 301 PhaseIdealLoop* loop_phase, | |
| 302 PhaseIterGVN* igvn) { | |
| 303 ProjNode* new_predicate_proj; | |
| 304 if (loop_phase != NULL) { | |
| 305 new_predicate_proj = loop_phase->create_new_if_for_predicate(predicate_proj, new_entry, reason); | |
| 306 } else { | |
| 307 new_predicate_proj = igvn->create_new_if_for_predicate(predicate_proj, new_entry, reason); | |
| 308 } | |
| 309 IfNode* iff = new_predicate_proj->in(0)->as_If(); | |
| 310 Node* ctrl = iff->in(0); | |
| 311 | |
| 312 // Match original condition since predicate's projections could be swapped. | |
| 313 assert(predicate_proj->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be"); | |
| 314 Node* opq = new (igvn->C, 2) Opaque1Node(igvn->C, predicate_proj->in(0)->in(1)->in(1)->in(1)); | |
| 315 igvn->C->add_predicate_opaq(opq); | |
| 316 | |
| 317 Node* bol = new (igvn->C, 2) Conv2BNode(opq); | |
| 318 if (loop_phase != NULL) { | |
| 319 loop_phase->register_new_node(opq, ctrl); | |
| 320 loop_phase->register_new_node(bol, ctrl); | |
| 321 } else { | |
| 322 igvn->register_new_node_with_optimizer(opq); | |
| 323 igvn->register_new_node_with_optimizer(bol); | |
| 324 } | |
| 325 igvn->hash_delete(iff); | |
| 326 iff->set_req(1, bol); | |
| 327 return new_predicate_proj; | |
| 328 } | |
| 329 | |
| 330 //--------------------------move_predicate----------------------- | |
| 331 // Cut predicate from old place and move it to new. | |
| 332 ProjNode* PhaseIdealLoop::move_predicate(ProjNode* predicate_proj, Node* new_entry, | |
| 333 Deoptimization::DeoptReason reason, | |
| 334 PhaseIdealLoop* loop_phase, | |
| 335 PhaseIterGVN* igvn) { | |
| 336 assert(new_entry != NULL, "must be"); | |
| 337 assert(predicate_proj->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be"); | |
| 338 IfNode* iff = predicate_proj->in(0)->as_If(); | |
| 339 Node* old_entry = iff->in(0); | |
| 340 | |
| 341 // Cut predicate from old place. | |
| 342 Node* old = predicate_proj; | |
| 343 igvn->_worklist.push(old); | |
| 3345 | 344 for (DUIterator_Last imin, i = old->last_outs(imin); i >= imin;) { |
| 2445 | 345 Node* use = old->last_out(i); // for each use... |
| 346 igvn->hash_delete(use); | |
| 347 igvn->_worklist.push(use); | |
| 348 // Update use-def info | |
| 349 uint uses_found = 0; | |
| 350 for (uint j = 0; j < use->req(); j++) { | |
| 351 if (use->in(j) == old) { | |
| 352 use->set_req(j, old_entry); | |
| 353 uses_found++; | |
| 354 if (loop_phase != NULL) { | |
| 355 if (use->is_CFG()) { | |
| 356 // When called from beautify_loops() idom is not constructed yet. | |
| 357 if (loop_phase->_idom != NULL) | |
| 358 loop_phase->set_idom(use, old_entry, loop_phase->dom_depth(use)); | |
| 359 } else { | |
| 360 loop_phase->set_ctrl(use, old_entry); | |
| 361 } | |
| 362 } | |
| 363 } | |
| 364 } | |
| 365 i -= uses_found; // we deleted 1 or more copies of this edge | |
| 366 } | |
| 367 | |
| 368 // Move predicate. | |
| 369 igvn->hash_delete(iff); | |
| 370 iff->set_req(0, new_entry); | |
| 371 igvn->_worklist.push(iff); | |
| 372 | |
| 373 if (loop_phase != NULL) { | |
| 374 // Fix up idom and ctrl. | |
| 375 loop_phase->set_ctrl(iff->in(1), new_entry); | |
| 376 loop_phase->set_ctrl(iff->in(1)->in(1), new_entry); | |
| 377 // When called from beautify_loops() idom is not constructed yet. | |
| 378 if (loop_phase->_idom != NULL) | |
| 379 loop_phase->set_idom(iff, new_entry, loop_phase->dom_depth(iff)); | |
| 380 } | |
| 381 | |
| 382 return predicate_proj; | |
| 383 } | |
| 384 | |
| 385 //--------------------------clone_loop_predicates----------------------- | |
| 386 // Interface from IGVN | |
| 3345 | 387 Node* PhaseIterGVN::clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { |
| 388 return PhaseIdealLoop::clone_loop_predicates(old_entry, new_entry, false, clone_limit_check, NULL, this); | |
| 2445 | 389 } |
| 3345 | 390 Node* PhaseIterGVN::move_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { |
| 391 return PhaseIdealLoop::clone_loop_predicates(old_entry, new_entry, true, clone_limit_check, NULL, this); | |
| 2445 | 392 } |
| 393 | |
| 394 // Interface from PhaseIdealLoop | |
| 3345 | 395 Node* PhaseIdealLoop::clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { |
| 396 return clone_loop_predicates(old_entry, new_entry, false, clone_limit_check, this, &this->_igvn); | |
| 2445 | 397 } |
| 3345 | 398 Node* PhaseIdealLoop::move_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { |
| 399 return clone_loop_predicates(old_entry, new_entry, true, clone_limit_check, this, &this->_igvn); | |
| 2445 | 400 } |
| 401 | |
| 402 // Clone loop predicates to cloned loops (peeled, unswitched, split_if). | |
| 403 Node* PhaseIdealLoop::clone_loop_predicates(Node* old_entry, Node* new_entry, | |
| 404 bool move_predicates, | |
| 3345 | 405 bool clone_limit_check, |
| 2445 | 406 PhaseIdealLoop* loop_phase, |
| 407 PhaseIterGVN* igvn) { | |
| 408 #ifdef ASSERT | |
| 409 if (new_entry == NULL || !(new_entry->is_Proj() || new_entry->is_Region() || new_entry->is_SafePoint())) { | |
| 410 if (new_entry != NULL) | |
| 411 new_entry->dump(); | |
| 412 assert(false, "not IfTrue, IfFalse, Region or SafePoint"); | |
| 413 } | |
| 414 #endif | |
| 415 // Search original predicates | |
| 416 Node* entry = old_entry; | |
| 3345 | 417 ProjNode* limit_check_proj = NULL; |
| 418 if (LoopLimitCheck) { | |
| 419 limit_check_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); | |
| 420 if (limit_check_proj != NULL) { | |
| 421 entry = entry->in(0)->in(0); | |
| 422 } | |
| 423 } | |
| 2445 | 424 if (UseLoopPredicate) { |
| 425 ProjNode* predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); | |
| 426 if (predicate_proj != NULL) { // right pattern that can be used by loop predication | |
| 427 if (move_predicates) { | |
| 428 new_entry = move_predicate(predicate_proj, new_entry, | |
| 429 Deoptimization::Reason_predicate, | |
| 430 loop_phase, igvn); | |
| 431 assert(new_entry == predicate_proj, "old predicate fall through projection"); | |
| 432 } else { | |
| 433 // clone predicate | |
| 434 new_entry = clone_predicate(predicate_proj, new_entry, | |
| 435 Deoptimization::Reason_predicate, | |
| 436 loop_phase, igvn); | |
| 437 assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone predicate"); | |
| 438 } | |
| 439 if (TraceLoopPredicate) { | |
| 440 tty->print_cr("Loop Predicate %s: ", move_predicates ? "moved" : "cloned"); | |
| 441 debug_only( new_entry->in(0)->dump(); ) | |
| 442 } | |
| 443 } | |
| 444 } | |
| 3345 | 445 if (limit_check_proj != NULL && clone_limit_check) { |
| 446 // Clone loop limit check last to insert it before loop. | |
| 447 // Don't clone a limit check which was already finalized | |
| 448 // for this counted loop (only one limit check is needed). | |
| 449 if (move_predicates) { | |
| 450 new_entry = move_predicate(limit_check_proj, new_entry, | |
| 451 Deoptimization::Reason_loop_limit_check, | |
| 452 loop_phase, igvn); | |
| 453 assert(new_entry == limit_check_proj, "old limit check fall through projection"); | |
| 454 } else { | |
| 455 new_entry = clone_predicate(limit_check_proj, new_entry, | |
| 456 Deoptimization::Reason_loop_limit_check, | |
| 457 loop_phase, igvn); | |
| 458 assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone limit check"); | |
| 459 } | |
| 460 if (TraceLoopLimitCheck) { | |
| 461 tty->print_cr("Loop Limit Check %s: ", move_predicates ? "moved" : "cloned"); | |
| 462 debug_only( new_entry->in(0)->dump(); ) | |
| 463 } | |
| 464 } | |
| 2445 | 465 return new_entry; |
| 466 } | |
| 467 | |
| 468 //--------------------------eliminate_loop_predicates----------------------- | |
| 469 void PhaseIdealLoop::eliminate_loop_predicates(Node* entry) { | |
| 3345 | 470 if (LoopLimitCheck) { |
| 471 Node* predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); | |
| 472 if (predicate != NULL) { | |
| 473 entry = entry->in(0)->in(0); | |
| 474 } | |
| 475 } | |
| 2445 | 476 if (UseLoopPredicate) { |
| 477 ProjNode* predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); | |
| 478 if (predicate_proj != NULL) { // right pattern that can be used by loop predication | |
| 479 Node* n = entry->in(0)->in(1)->in(1); | |
| 480 assert(n->Opcode()==Op_Opaque1, "must be"); | |
| 481 // Remove Opaque1 node from predicates list. | |
| 482 // IGVN will remove this predicate check. | |
| 483 _igvn.replace_node(n, n->in(1)); | |
| 484 } | |
| 485 } | |
| 486 } | |
| 487 | |
| 488 //--------------------------skip_loop_predicates------------------------------ | |
| 489 // Skip related predicates. | |
| 490 Node* PhaseIdealLoop::skip_loop_predicates(Node* entry) { | |
| 491 Node* predicate = NULL; | |
| 3345 | 492 if (LoopLimitCheck) { |
| 493 predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); | |
| 494 if (predicate != NULL) { | |
| 495 entry = entry->in(0)->in(0); | |
| 496 } | |
| 497 } | |
| 2445 | 498 if (UseLoopPredicate) { |
| 499 predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); | |
| 500 if (predicate != NULL) { // right pattern that can be used by loop predication | |
| 501 IfNode* iff = entry->in(0)->as_If(); | |
| 502 ProjNode* uncommon_proj = iff->proj_out(1 - entry->as_Proj()->_con); | |
| 503 Node* rgn = uncommon_proj->unique_ctrl_out(); | |
| 504 assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); | |
| 505 entry = entry->in(0)->in(0); | |
| 506 while (entry != NULL && entry->is_Proj() && entry->in(0)->is_If()) { | |
| 507 uncommon_proj = entry->in(0)->as_If()->proj_out(1 - entry->as_Proj()->_con); | |
| 508 if (uncommon_proj->unique_ctrl_out() != rgn) | |
| 509 break; | |
| 510 entry = entry->in(0)->in(0); | |
| 511 } | |
| 512 } | |
| 513 } | |
| 514 return entry; | |
| 515 } | |
| 516 | |
| 517 //--------------------------find_predicate_insertion_point------------------- | |
| 518 // Find a good location to insert a predicate | |
| 519 ProjNode* PhaseIdealLoop::find_predicate_insertion_point(Node* start_c, Deoptimization::DeoptReason reason) { | |
| 520 if (start_c == NULL || !start_c->is_Proj()) | |
| 521 return NULL; | |
| 522 if (is_uncommon_trap_if_pattern(start_c->as_Proj(), reason)) { | |
| 523 return start_c->as_Proj(); | |
| 524 } | |
| 525 return NULL; | |
| 526 } | |
| 527 | |
| 528 //--------------------------find_predicate------------------------------------ | |
| 529 // Find a predicate | |
| 530 Node* PhaseIdealLoop::find_predicate(Node* entry) { | |
| 531 Node* predicate = NULL; | |
| 3345 | 532 if (LoopLimitCheck) { |
| 533 predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); | |
| 534 if (predicate != NULL) { // right pattern that can be used by loop predication | |
| 535 return entry; | |
| 536 } | |
| 537 } | |
| 2445 | 538 if (UseLoopPredicate) { |
| 539 predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); | |
| 540 if (predicate != NULL) { // right pattern that can be used by loop predication | |
| 541 return entry; | |
| 542 } | |
| 543 } | |
| 544 return NULL; | |
| 545 } | |
| 546 | |
| 547 //------------------------------Invariance----------------------------------- | |
| 548 // Helper class for loop_predication_impl to compute invariance on the fly and | |
| 549 // clone invariants. | |
| 550 class Invariance : public StackObj { | |
| 551 VectorSet _visited, _invariant; | |
| 552 Node_Stack _stack; | |
| 553 VectorSet _clone_visited; | |
| 554 Node_List _old_new; // map of old to new (clone) | |
| 555 IdealLoopTree* _lpt; | |
| 556 PhaseIdealLoop* _phase; | |
| 557 | |
| 558 // Helper function to set up the invariance for invariance computation | |
| 559 // If n is a known invariant, set up directly. Otherwise, look up the | |
| 560 // the possibility to push n onto the stack for further processing. | |
| 561 void visit(Node* use, Node* n) { | |
| 562 if (_lpt->is_invariant(n)) { // known invariant | |
| 563 _invariant.set(n->_idx); | |
| 564 } else if (!n->is_CFG()) { | |
| 565 Node *n_ctrl = _phase->ctrl_or_self(n); | |
| 566 Node *u_ctrl = _phase->ctrl_or_self(use); // self if use is a CFG | |
| 567 if (_phase->is_dominator(n_ctrl, u_ctrl)) { | |
| 568 _stack.push(n, n->in(0) == NULL ? 1 : 0); | |
| 569 } | |
| 570 } | |
| 571 } | |
| 572 | |
| 573 // Compute invariance for "the_node" and (possibly) all its inputs recursively | |
| 574 // on the fly | |
| 575 void compute_invariance(Node* n) { | |
| 576 assert(_visited.test(n->_idx), "must be"); | |
| 577 visit(n, n); | |
| 578 while (_stack.is_nonempty()) { | |
| 579 Node* n = _stack.node(); | |
| 580 uint idx = _stack.index(); | |
| 581 if (idx == n->req()) { // all inputs are processed | |
| 582 _stack.pop(); | |
| 583 // n is invariant if it's inputs are all invariant | |
| 584 bool all_inputs_invariant = true; | |
| 585 for (uint i = 0; i < n->req(); i++) { | |
| 586 Node* in = n->in(i); | |
| 587 if (in == NULL) continue; | |
| 588 assert(_visited.test(in->_idx), "must have visited input"); | |
| 589 if (!_invariant.test(in->_idx)) { // bad guy | |
| 590 all_inputs_invariant = false; | |
| 591 break; | |
| 592 } | |
| 593 } | |
| 594 if (all_inputs_invariant) { | |
| 595 _invariant.set(n->_idx); // I am a invariant too | |
| 596 } | |
| 597 } else { // process next input | |
| 598 _stack.set_index(idx + 1); | |
| 599 Node* m = n->in(idx); | |
| 600 if (m != NULL && !_visited.test_set(m->_idx)) { | |
| 601 visit(n, m); | |
| 602 } | |
| 603 } | |
| 604 } | |
| 605 } | |
| 606 | |
| 607 // Helper function to set up _old_new map for clone_nodes. | |
| 608 // If n is a known invariant, set up directly ("clone" of n == n). | |
| 609 // Otherwise, push n onto the stack for real cloning. | |
| 610 void clone_visit(Node* n) { | |
| 611 assert(_invariant.test(n->_idx), "must be invariant"); | |
| 612 if (_lpt->is_invariant(n)) { // known invariant | |
| 613 _old_new.map(n->_idx, n); | |
| 614 } else { // to be cloned | |
| 615 assert(!n->is_CFG(), "should not see CFG here"); | |
| 616 _stack.push(n, n->in(0) == NULL ? 1 : 0); | |
| 617 } | |
| 618 } | |
| 619 | |
| 620 // Clone "n" and (possibly) all its inputs recursively | |
| 621 void clone_nodes(Node* n, Node* ctrl) { | |
| 622 clone_visit(n); | |
| 623 while (_stack.is_nonempty()) { | |
| 624 Node* n = _stack.node(); | |
| 625 uint idx = _stack.index(); | |
| 626 if (idx == n->req()) { // all inputs processed, clone n! | |
| 627 _stack.pop(); | |
| 628 // clone invariant node | |
| 629 Node* n_cl = n->clone(); | |
| 630 _old_new.map(n->_idx, n_cl); | |
| 631 _phase->register_new_node(n_cl, ctrl); | |
| 632 for (uint i = 0; i < n->req(); i++) { | |
| 633 Node* in = n_cl->in(i); | |
| 634 if (in == NULL) continue; | |
| 635 n_cl->set_req(i, _old_new[in->_idx]); | |
| 636 } | |
| 637 } else { // process next input | |
| 638 _stack.set_index(idx + 1); | |
| 639 Node* m = n->in(idx); | |
| 640 if (m != NULL && !_clone_visited.test_set(m->_idx)) { | |
| 641 clone_visit(m); // visit the input | |
| 642 } | |
| 643 } | |
| 644 } | |
| 645 } | |
| 646 | |
| 647 public: | |
| 648 Invariance(Arena* area, IdealLoopTree* lpt) : | |
| 649 _lpt(lpt), _phase(lpt->_phase), | |
| 650 _visited(area), _invariant(area), _stack(area, 10 /* guess */), | |
| 651 _clone_visited(area), _old_new(area) | |
| 652 {} | |
| 653 | |
| 654 // Map old to n for invariance computation and clone | |
| 655 void map_ctrl(Node* old, Node* n) { | |
| 656 assert(old->is_CFG() && n->is_CFG(), "must be"); | |
| 657 _old_new.map(old->_idx, n); // "clone" of old is n | |
| 658 _invariant.set(old->_idx); // old is invariant | |
| 659 _clone_visited.set(old->_idx); | |
| 660 } | |
| 661 | |
| 662 // Driver function to compute invariance | |
| 663 bool is_invariant(Node* n) { | |
| 664 if (!_visited.test_set(n->_idx)) | |
| 665 compute_invariance(n); | |
| 666 return (_invariant.test(n->_idx) != 0); | |
| 667 } | |
| 668 | |
| 669 // Driver function to clone invariant | |
| 670 Node* clone(Node* n, Node* ctrl) { | |
| 671 assert(ctrl->is_CFG(), "must be"); | |
| 672 assert(_invariant.test(n->_idx), "must be an invariant"); | |
| 673 if (!_clone_visited.test(n->_idx)) | |
| 674 clone_nodes(n, ctrl); | |
| 675 return _old_new[n->_idx]; | |
| 676 } | |
| 677 }; | |
| 678 | |
| 679 //------------------------------is_range_check_if ----------------------------------- | |
| 680 // Returns true if the predicate of iff is in "scale*iv + offset u< load_range(ptr)" format | |
| 681 // Note: this function is particularly designed for loop predication. We require load_range | |
| 682 // and offset to be loop invariant computed on the fly by "invar" | |
| 683 bool IdealLoopTree::is_range_check_if(IfNode *iff, PhaseIdealLoop *phase, Invariance& invar) const { | |
| 684 if (!is_loop_exit(iff)) { | |
| 685 return false; | |
| 686 } | |
| 687 if (!iff->in(1)->is_Bool()) { | |
| 688 return false; | |
| 689 } | |
| 690 const BoolNode *bol = iff->in(1)->as_Bool(); | |
| 691 if (bol->_test._test != BoolTest::lt) { | |
| 692 return false; | |
| 693 } | |
| 694 if (!bol->in(1)->is_Cmp()) { | |
| 695 return false; | |
| 696 } | |
| 697 const CmpNode *cmp = bol->in(1)->as_Cmp(); | |
| 698 if (cmp->Opcode() != Op_CmpU) { | |
| 699 return false; | |
| 700 } | |
| 701 Node* range = cmp->in(2); | |
| 702 if (range->Opcode() != Op_LoadRange) { | |
| 703 const TypeInt* tint = phase->_igvn.type(range)->isa_int(); | |
| 3345 | 704 if (tint == NULL || tint->empty() || tint->_lo < 0) { |
| 2445 | 705 // Allow predication on positive values that aren't LoadRanges. |
| 706 // This allows optimization of loops where the length of the | |
| 707 // array is a known value and doesn't need to be loaded back | |
| 708 // from the array. | |
| 709 return false; | |
| 710 } | |
| 711 } | |
| 712 if (!invar.is_invariant(range)) { | |
| 713 return false; | |
| 714 } | |
| 715 Node *iv = _head->as_CountedLoop()->phi(); | |
| 716 int scale = 0; | |
| 717 Node *offset = NULL; | |
| 718 if (!phase->is_scaled_iv_plus_offset(cmp->in(1), iv, &scale, &offset)) { | |
| 719 return false; | |
| 720 } | |
| 721 if (offset && !invar.is_invariant(offset)) { // offset must be invariant | |
| 722 return false; | |
| 723 } | |
| 724 return true; | |
| 725 } | |
| 726 | |
| 727 //------------------------------rc_predicate----------------------------------- | |
| 728 // Create a range check predicate | |
| 729 // | |
| 730 // for (i = init; i < limit; i += stride) { | |
| 731 // a[scale*i+offset] | |
| 732 // } | |
| 733 // | |
| 734 // Compute max(scale*i + offset) for init <= i < limit and build the predicate | |
| 735 // as "max(scale*i + offset) u< a.length". | |
| 736 // | |
| 737 // There are two cases for max(scale*i + offset): | |
| 738 // (1) stride*scale > 0 | |
| 739 // max(scale*i + offset) = scale*(limit-stride) + offset | |
| 740 // (2) stride*scale < 0 | |
| 741 // max(scale*i + offset) = scale*init + offset | |
| 3345 | 742 BoolNode* PhaseIdealLoop::rc_predicate(IdealLoopTree *loop, Node* ctrl, |
| 2445 | 743 int scale, Node* offset, |
| 744 Node* init, Node* limit, Node* stride, | |
| 745 Node* range, bool upper) { | |
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746 stringStream* predString = NULL; |
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747 if (TraceLoopPredicate) { |
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748 predString = new stringStream(); |
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749 predString->print("rc_predicate "); |
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750 } |
| 2445 | 751 |
| 752 Node* max_idx_expr = init; | |
| 753 int stride_con = stride->get_int(); | |
| 754 if ((stride_con > 0) == (scale > 0) == upper) { | |
| 3345 | 755 if (LoopLimitCheck) { |
| 756 // With LoopLimitCheck limit is not exact. | |
| 757 // Calculate exact limit here. | |
| 758 // Note, counted loop's test is '<' or '>'. | |
| 759 limit = exact_limit(loop); | |
| 760 max_idx_expr = new (C, 3) SubINode(limit, stride); | |
| 761 register_new_node(max_idx_expr, ctrl); | |
| 762 if (TraceLoopPredicate) predString->print("(limit - stride) "); | |
| 763 } else { | |
| 764 max_idx_expr = new (C, 3) SubINode(limit, stride); | |
| 765 register_new_node(max_idx_expr, ctrl); | |
| 766 if (TraceLoopPredicate) predString->print("(limit - stride) "); | |
| 767 } | |
| 2445 | 768 } else { |
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769 if (TraceLoopPredicate) predString->print("init "); |
| 2445 | 770 } |
| 771 | |
| 772 if (scale != 1) { | |
| 773 ConNode* con_scale = _igvn.intcon(scale); | |
| 774 max_idx_expr = new (C, 3) MulINode(max_idx_expr, con_scale); | |
| 775 register_new_node(max_idx_expr, ctrl); | |
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776 if (TraceLoopPredicate) predString->print("* %d ", scale); |
| 2445 | 777 } |
| 778 | |
| 779 if (offset && (!offset->is_Con() || offset->get_int() != 0)){ | |
| 780 max_idx_expr = new (C, 3) AddINode(max_idx_expr, offset); | |
| 781 register_new_node(max_idx_expr, ctrl); | |
| 782 if (TraceLoopPredicate) | |
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783 if (offset->is_Con()) predString->print("+ %d ", offset->get_int()); |
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784 else predString->print("+ offset "); |
| 2445 | 785 } |
| 786 | |
| 787 CmpUNode* cmp = new (C, 3) CmpUNode(max_idx_expr, range); | |
| 788 register_new_node(cmp, ctrl); | |
| 789 BoolNode* bol = new (C, 2) BoolNode(cmp, BoolTest::lt); | |
| 790 register_new_node(bol, ctrl); | |
| 791 | |
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792 if (TraceLoopPredicate) { |
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793 predString->print_cr("<u range"); |
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794 tty->print(predString->as_string()); |
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795 } |
| 2445 | 796 return bol; |
| 797 } | |
| 798 | |
| 799 //------------------------------ loop_predication_impl-------------------------- | |
| 800 // Insert loop predicates for null checks and range checks | |
| 801 bool PhaseIdealLoop::loop_predication_impl(IdealLoopTree *loop) { | |
| 802 if (!UseLoopPredicate) return false; | |
| 803 | |
| 804 if (!loop->_head->is_Loop()) { | |
| 805 // Could be a simple region when irreducible loops are present. | |
| 806 return false; | |
| 807 } | |
| 3345 | 808 LoopNode* head = loop->_head->as_Loop(); |
| 2445 | 809 |
| 3345 | 810 if (head->unique_ctrl_out()->Opcode() == Op_NeverBranch) { |
| 2445 | 811 // do nothing for infinite loops |
| 812 return false; | |
| 813 } | |
| 814 | |
| 815 CountedLoopNode *cl = NULL; | |
| 3345 | 816 if (head->is_CountedLoop()) { |
| 817 cl = head->as_CountedLoop(); | |
| 2445 | 818 // do nothing for iteration-splitted loops |
| 819 if (!cl->is_normal_loop()) return false; | |
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820 // Avoid RCE if Counted loop's test is '!='. |
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821 BoolTest::mask bt = cl->loopexit()->test_trip(); |
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822 if (bt != BoolTest::lt && bt != BoolTest::gt) |
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823 cl = NULL; |
| 2445 | 824 } |
| 825 | |
| 3345 | 826 Node* entry = head->in(LoopNode::EntryControl); |
| 827 ProjNode *predicate_proj = NULL; | |
| 828 // Loop limit check predicate should be near the loop. | |
| 829 if (LoopLimitCheck) { | |
| 830 predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); | |
| 831 if (predicate_proj != NULL) | |
| 832 entry = predicate_proj->in(0)->in(0); | |
| 833 } | |
| 2445 | 834 |
| 3345 | 835 predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); |
| 2445 | 836 if (!predicate_proj) { |
| 837 #ifndef PRODUCT | |
| 838 if (TraceLoopPredicate) { | |
| 839 tty->print("missing predicate:"); | |
| 840 loop->dump_head(); | |
| 3345 | 841 head->dump(1); |
| 2445 | 842 } |
| 843 #endif | |
| 844 return false; | |
| 845 } | |
| 846 ConNode* zero = _igvn.intcon(0); | |
| 847 set_ctrl(zero, C->root()); | |
| 848 | |
| 849 ResourceArea *area = Thread::current()->resource_area(); | |
| 850 Invariance invar(area, loop); | |
| 851 | |
| 852 // Create list of if-projs such that a newer proj dominates all older | |
| 853 // projs in the list, and they all dominate loop->tail() | |
| 854 Node_List if_proj_list(area); | |
| 855 Node *current_proj = loop->tail(); //start from tail | |
| 856 while (current_proj != head) { | |
| 857 if (loop == get_loop(current_proj) && // still in the loop ? | |
| 858 current_proj->is_Proj() && // is a projection ? | |
| 859 current_proj->in(0)->Opcode() == Op_If) { // is a if projection ? | |
| 860 if_proj_list.push(current_proj); | |
| 861 } | |
| 862 current_proj = idom(current_proj); | |
| 863 } | |
| 864 | |
| 865 bool hoisted = false; // true if at least one proj is promoted | |
| 866 while (if_proj_list.size() > 0) { | |
| 867 // Following are changed to nonnull when a predicate can be hoisted | |
| 868 ProjNode* new_predicate_proj = NULL; | |
| 869 | |
| 870 ProjNode* proj = if_proj_list.pop()->as_Proj(); | |
| 871 IfNode* iff = proj->in(0)->as_If(); | |
| 872 | |
| 873 if (!is_uncommon_trap_if_pattern(proj, Deoptimization::Reason_none)) { | |
| 874 if (loop->is_loop_exit(iff)) { | |
| 875 // stop processing the remaining projs in the list because the execution of them | |
| 876 // depends on the condition of "iff" (iff->in(1)). | |
| 877 break; | |
| 878 } else { | |
| 879 // Both arms are inside the loop. There are two cases: | |
| 880 // (1) there is one backward branch. In this case, any remaining proj | |
| 881 // in the if_proj list post-dominates "iff". So, the condition of "iff" | |
| 882 // does not determine the execution the remining projs directly, and we | |
| 883 // can safely continue. | |
| 884 // (2) both arms are forwarded, i.e. a diamond shape. In this case, "proj" | |
| 885 // does not dominate loop->tail(), so it can not be in the if_proj list. | |
| 886 continue; | |
| 887 } | |
| 888 } | |
| 889 | |
| 890 Node* test = iff->in(1); | |
| 891 if (!test->is_Bool()){ //Conv2B, ... | |
| 892 continue; | |
| 893 } | |
| 894 BoolNode* bol = test->as_Bool(); | |
| 895 if (invar.is_invariant(bol)) { | |
| 896 // Invariant test | |
| 897 new_predicate_proj = create_new_if_for_predicate(predicate_proj, NULL, | |
| 898 Deoptimization::Reason_predicate); | |
| 899 Node* ctrl = new_predicate_proj->in(0)->as_If()->in(0); | |
| 900 BoolNode* new_predicate_bol = invar.clone(bol, ctrl)->as_Bool(); | |
| 901 | |
| 902 // Negate test if necessary | |
| 903 bool negated = false; | |
| 904 if (proj->_con != predicate_proj->_con) { | |
| 905 new_predicate_bol = new (C, 2) BoolNode(new_predicate_bol->in(1), new_predicate_bol->_test.negate()); | |
| 906 register_new_node(new_predicate_bol, ctrl); | |
| 907 negated = true; | |
| 908 } | |
| 909 IfNode* new_predicate_iff = new_predicate_proj->in(0)->as_If(); | |
| 910 _igvn.hash_delete(new_predicate_iff); | |
| 911 new_predicate_iff->set_req(1, new_predicate_bol); | |
| 912 #ifndef PRODUCT | |
| 913 if (TraceLoopPredicate) { | |
| 914 tty->print("Predicate invariant if%s: %d ", negated ? " negated" : "", new_predicate_iff->_idx); | |
| 915 loop->dump_head(); | |
| 916 } else if (TraceLoopOpts) { | |
| 917 tty->print("Predicate IC "); | |
| 918 loop->dump_head(); | |
| 919 } | |
| 920 #endif | |
| 921 } else if (cl != NULL && loop->is_range_check_if(iff, this, invar)) { | |
| 922 assert(proj->_con == predicate_proj->_con, "must match"); | |
| 923 | |
| 924 // Range check for counted loops | |
| 925 const Node* cmp = bol->in(1)->as_Cmp(); | |
| 926 Node* idx = cmp->in(1); | |
| 927 assert(!invar.is_invariant(idx), "index is variant"); | |
| 928 Node* rng = cmp->in(2); | |
| 3345 | 929 assert(rng->Opcode() == Op_LoadRange || _igvn.type(rng)->is_int() >= 0, "must be"); |
| 2445 | 930 assert(invar.is_invariant(rng), "range must be invariant"); |
| 931 int scale = 1; | |
| 932 Node* offset = zero; | |
| 933 bool ok = is_scaled_iv_plus_offset(idx, cl->phi(), &scale, &offset); | |
| 934 assert(ok, "must be index expression"); | |
| 935 | |
| 936 Node* init = cl->init_trip(); | |
| 937 Node* limit = cl->limit(); | |
| 938 Node* stride = cl->stride(); | |
| 939 | |
| 940 // Build if's for the upper and lower bound tests. The | |
| 941 // lower_bound test will dominate the upper bound test and all | |
| 942 // cloned or created nodes will use the lower bound test as | |
| 943 // their declared control. | |
| 944 ProjNode* lower_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate); | |
| 945 ProjNode* upper_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate); | |
| 946 assert(upper_bound_proj->in(0)->as_If()->in(0) == lower_bound_proj, "should dominate"); | |
| 947 Node *ctrl = lower_bound_proj->in(0)->as_If()->in(0); | |
| 948 | |
| 949 // Perform cloning to keep Invariance state correct since the | |
| 950 // late schedule will place invariant things in the loop. | |
| 951 rng = invar.clone(rng, ctrl); | |
| 952 if (offset && offset != zero) { | |
| 953 assert(invar.is_invariant(offset), "offset must be loop invariant"); | |
| 954 offset = invar.clone(offset, ctrl); | |
| 955 } | |
| 956 | |
| 957 // Test the lower bound | |
| 3345 | 958 Node* lower_bound_bol = rc_predicate(loop, ctrl, scale, offset, init, limit, stride, rng, false); |
| 2445 | 959 IfNode* lower_bound_iff = lower_bound_proj->in(0)->as_If(); |
| 960 _igvn.hash_delete(lower_bound_iff); | |
| 961 lower_bound_iff->set_req(1, lower_bound_bol); | |
| 962 if (TraceLoopPredicate) tty->print_cr("lower bound check if: %d", lower_bound_iff->_idx); | |
| 963 | |
| 964 // Test the upper bound | |
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965 Node* upper_bound_bol = rc_predicate(loop, lower_bound_proj, scale, offset, init, limit, stride, rng, true); |
| 2445 | 966 IfNode* upper_bound_iff = upper_bound_proj->in(0)->as_If(); |
| 967 _igvn.hash_delete(upper_bound_iff); | |
| 968 upper_bound_iff->set_req(1, upper_bound_bol); | |
| 969 if (TraceLoopPredicate) tty->print_cr("upper bound check if: %d", lower_bound_iff->_idx); | |
| 970 | |
| 971 // Fall through into rest of the clean up code which will move | |
| 972 // any dependent nodes onto the upper bound test. | |
| 973 new_predicate_proj = upper_bound_proj; | |
| 974 | |
| 975 #ifndef PRODUCT | |
| 976 if (TraceLoopOpts && !TraceLoopPredicate) { | |
| 977 tty->print("Predicate RC "); | |
| 978 loop->dump_head(); | |
| 979 } | |
| 980 #endif | |
| 981 } else { | |
| 982 // Loop variant check (for example, range check in non-counted loop) | |
| 983 // with uncommon trap. | |
| 984 continue; | |
| 985 } | |
| 986 assert(new_predicate_proj != NULL, "sanity"); | |
| 987 // Success - attach condition (new_predicate_bol) to predicate if | |
| 988 invar.map_ctrl(proj, new_predicate_proj); // so that invariance test can be appropriate | |
| 989 | |
| 990 // Eliminate the old If in the loop body | |
| 991 dominated_by( new_predicate_proj, iff, proj->_con != new_predicate_proj->_con ); | |
| 992 | |
| 993 hoisted = true; | |
| 994 C->set_major_progress(); | |
| 995 } // end while | |
| 996 | |
| 997 #ifndef PRODUCT | |
| 998 // report that the loop predication has been actually performed | |
| 999 // for this loop | |
| 1000 if (TraceLoopPredicate && hoisted) { | |
| 1001 tty->print("Loop Predication Performed:"); | |
| 1002 loop->dump_head(); | |
| 1003 } | |
| 1004 #endif | |
| 1005 | |
| 1006 return hoisted; | |
| 1007 } | |
| 1008 | |
| 1009 //------------------------------loop_predication-------------------------------- | |
| 1010 // driver routine for loop predication optimization | |
| 1011 bool IdealLoopTree::loop_predication( PhaseIdealLoop *phase) { | |
| 1012 bool hoisted = false; | |
| 1013 // Recursively promote predicates | |
| 1014 if (_child) { | |
| 1015 hoisted = _child->loop_predication( phase); | |
| 1016 } | |
| 1017 | |
| 1018 // self | |
| 1019 if (!_irreducible && !tail()->is_top()) { | |
| 1020 hoisted |= phase->loop_predication_impl(this); | |
| 1021 } | |
| 1022 | |
| 1023 if (_next) { //sibling | |
| 1024 hoisted |= _next->loop_predication( phase); | |
| 1025 } | |
| 1026 | |
| 1027 return hoisted; | |
| 1028 } |