Mercurial > hg > graal-jvmci-8
annotate src/share/vm/opto/loopPredicate.cpp @ 24218:719853999215 jvmci-0.32
Merge with jdk8u141-b15
| author | Doug Simon <doug.simon@oracle.com> |
|---|---|
| date | Mon, 14 Aug 2017 23:20:38 +0200 |
| parents | dd9cc155639c 37ba410ffd43 |
| children |
| rev | line source |
|---|---|
| 2445 | 1 /* |
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2 * Copyright (c) 2011, 2014, Oracle and/or its affiliates. All rights reserved. |
| 2445 | 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" | |
| 24206 | 31 #include "opto/matcher.hpp" |
| 2445 | 32 #include "opto/mulnode.hpp" |
| 33 #include "opto/rootnode.hpp" | |
| 34 #include "opto/subnode.hpp" | |
| 35 | |
| 36 /* | |
| 37 * The general idea of Loop Predication is to insert a predicate on the entry | |
| 38 * path to a loop, and raise a uncommon trap if the check of the condition fails. | |
| 39 * The condition checks are promoted from inside the loop body, and thus | |
| 40 * the checks inside the loop could be eliminated. Currently, loop predication | |
| 41 * optimization has been applied to remove array range check and loop invariant | |
| 42 * checks (such as null checks). | |
| 43 */ | |
| 44 | |
| 45 //-------------------------------register_control------------------------- | |
| 46 void PhaseIdealLoop::register_control(Node* n, IdealLoopTree *loop, Node* pred) { | |
| 47 assert(n->is_CFG(), "must be control node"); | |
| 48 _igvn.register_new_node_with_optimizer(n); | |
| 49 loop->_body.push(n); | |
| 50 set_loop(n, loop); | |
| 51 // When called from beautify_loops() idom is not constructed yet. | |
| 52 if (_idom != NULL) { | |
| 53 set_idom(n, pred, dom_depth(pred)); | |
| 54 } | |
| 55 } | |
| 56 | |
| 57 //------------------------------create_new_if_for_predicate------------------------ | |
| 58 // create a new if above the uct_if_pattern for the predicate to be promoted. | |
| 59 // | |
| 60 // before after | |
| 61 // ---------- ---------- | |
| 62 // ctrl ctrl | |
| 63 // | | | |
| 64 // | | | |
| 65 // v v | |
| 66 // iff new_iff | |
| 67 // / \ / \ | |
| 68 // / \ / \ | |
| 69 // v v v v | |
| 70 // uncommon_proj cont_proj if_uct if_cont | |
| 71 // \ | | | | | |
| 72 // \ | | | | | |
| 73 // v v v | v | |
| 74 // rgn loop | iff | |
| 75 // | | / \ | |
| 76 // | | / \ | |
| 77 // v | v v | |
| 78 // uncommon_trap | uncommon_proj cont_proj | |
| 79 // \ \ | | | |
| 80 // \ \ | | | |
| 81 // v v v v | |
| 82 // rgn loop | |
| 83 // | | |
| 84 // | | |
| 85 // v | |
| 86 // uncommon_trap | |
| 87 // | |
| 88 // | |
| 89 // We will create a region to guard the uct call if there is no one there. | |
| 90 // The true projecttion (if_cont) of the new_iff is returned. | |
| 91 // This code is also used to clone predicates to clonned loops. | |
| 92 ProjNode* PhaseIdealLoop::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry, | |
| 93 Deoptimization::DeoptReason reason) { | |
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94 assert(cont_proj->is_uncommon_trap_if_pattern(reason), "must be a uct if pattern!"); |
| 2445 | 95 IfNode* iff = cont_proj->in(0)->as_If(); |
| 96 | |
| 97 ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con); | |
| 98 Node *rgn = uncommon_proj->unique_ctrl_out(); | |
| 99 assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); | |
| 100 | |
| 101 uint proj_index = 1; // region's edge corresponding to uncommon_proj | |
| 102 if (!rgn->is_Region()) { // create a region to guard the call | |
| 103 assert(rgn->is_Call(), "must be call uct"); | |
| 104 CallNode* call = rgn->as_Call(); | |
| 105 IdealLoopTree* loop = get_loop(call); | |
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106 rgn = new (C) RegionNode(1); |
| 2445 | 107 rgn->add_req(uncommon_proj); |
| 108 register_control(rgn, loop, uncommon_proj); | |
| 109 _igvn.hash_delete(call); | |
| 110 call->set_req(0, rgn); | |
| 111 // When called from beautify_loops() idom is not constructed yet. | |
| 112 if (_idom != NULL) { | |
| 113 set_idom(call, rgn, dom_depth(rgn)); | |
| 114 } | |
| 115 } else { | |
| 116 // Find region's edge corresponding to uncommon_proj | |
| 117 for (; proj_index < rgn->req(); proj_index++) | |
| 118 if (rgn->in(proj_index) == uncommon_proj) break; | |
| 119 assert(proj_index < rgn->req(), "sanity"); | |
| 120 } | |
| 121 | |
| 122 Node* entry = iff->in(0); | |
| 123 if (new_entry != NULL) { | |
| 124 // Clonning the predicate to new location. | |
| 125 entry = new_entry; | |
| 126 } | |
| 127 // Create new_iff | |
| 128 IdealLoopTree* lp = get_loop(entry); | |
| 129 IfNode *new_iff = iff->clone()->as_If(); | |
| 130 new_iff->set_req(0, entry); | |
| 131 register_control(new_iff, lp, entry); | |
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132 Node *if_cont = new (C) IfTrueNode(new_iff); |
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133 Node *if_uct = new (C) IfFalseNode(new_iff); |
| 2445 | 134 if (cont_proj->is_IfFalse()) { |
| 135 // Swap | |
| 136 Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp; | |
| 137 } | |
| 138 register_control(if_cont, lp, new_iff); | |
| 139 register_control(if_uct, get_loop(rgn), new_iff); | |
| 140 | |
| 141 // if_uct to rgn | |
| 142 _igvn.hash_delete(rgn); | |
| 143 rgn->add_req(if_uct); | |
| 144 // When called from beautify_loops() idom is not constructed yet. | |
| 145 if (_idom != NULL) { | |
| 146 Node* ridom = idom(rgn); | |
| 147 Node* nrdom = dom_lca(ridom, new_iff); | |
| 148 set_idom(rgn, nrdom, dom_depth(rgn)); | |
| 149 } | |
| 150 | |
| 151 // If rgn has phis add new edges which has the same | |
| 152 // value as on original uncommon_proj pass. | |
| 153 assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last"); | |
| 154 bool has_phi = false; | |
| 155 for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) { | |
| 156 Node* use = rgn->fast_out(i); | |
| 157 if (use->is_Phi() && use->outcnt() > 0) { | |
| 158 assert(use->in(0) == rgn, ""); | |
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159 _igvn.rehash_node_delayed(use); |
| 2445 | 160 use->add_req(use->in(proj_index)); |
| 161 has_phi = true; | |
| 162 } | |
| 163 } | |
| 164 assert(!has_phi || rgn->req() > 3, "no phis when region is created"); | |
| 165 | |
| 166 if (new_entry == NULL) { | |
| 167 // Attach if_cont to iff | |
| 168 _igvn.hash_delete(iff); | |
| 169 iff->set_req(0, if_cont); | |
| 170 if (_idom != NULL) { | |
| 171 set_idom(iff, if_cont, dom_depth(iff)); | |
| 172 } | |
| 173 } | |
| 174 return if_cont->as_Proj(); | |
| 175 } | |
| 176 | |
| 177 //------------------------------create_new_if_for_predicate------------------------ | |
| 178 // Create a new if below new_entry for the predicate to be cloned (IGVN optimization) | |
| 179 ProjNode* PhaseIterGVN::create_new_if_for_predicate(ProjNode* cont_proj, Node* new_entry, | |
| 180 Deoptimization::DeoptReason reason) { | |
| 181 assert(new_entry != 0, "only used for clone predicate"); | |
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182 assert(cont_proj->is_uncommon_trap_if_pattern(reason), "must be a uct if pattern!"); |
| 2445 | 183 IfNode* iff = cont_proj->in(0)->as_If(); |
| 184 | |
| 185 ProjNode *uncommon_proj = iff->proj_out(1 - cont_proj->_con); | |
| 186 Node *rgn = uncommon_proj->unique_ctrl_out(); | |
| 187 assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); | |
| 188 | |
| 189 uint proj_index = 1; // region's edge corresponding to uncommon_proj | |
| 190 if (!rgn->is_Region()) { // create a region to guard the call | |
| 191 assert(rgn->is_Call(), "must be call uct"); | |
| 192 CallNode* call = rgn->as_Call(); | |
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193 rgn = new (C) RegionNode(1); |
| 2445 | 194 register_new_node_with_optimizer(rgn); |
| 195 rgn->add_req(uncommon_proj); | |
| 196 hash_delete(call); | |
| 197 call->set_req(0, rgn); | |
| 198 } else { | |
| 199 // Find region's edge corresponding to uncommon_proj | |
| 200 for (; proj_index < rgn->req(); proj_index++) | |
| 201 if (rgn->in(proj_index) == uncommon_proj) break; | |
| 202 assert(proj_index < rgn->req(), "sanity"); | |
| 203 } | |
| 204 | |
| 205 // Create new_iff in new location. | |
| 206 IfNode *new_iff = iff->clone()->as_If(); | |
| 207 new_iff->set_req(0, new_entry); | |
| 208 | |
| 209 register_new_node_with_optimizer(new_iff); | |
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210 Node *if_cont = new (C) IfTrueNode(new_iff); |
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211 Node *if_uct = new (C) IfFalseNode(new_iff); |
| 2445 | 212 if (cont_proj->is_IfFalse()) { |
| 213 // Swap | |
| 214 Node* tmp = if_uct; if_uct = if_cont; if_cont = tmp; | |
| 215 } | |
| 216 register_new_node_with_optimizer(if_cont); | |
| 217 register_new_node_with_optimizer(if_uct); | |
| 218 | |
| 219 // if_uct to rgn | |
| 220 hash_delete(rgn); | |
| 221 rgn->add_req(if_uct); | |
| 222 | |
| 223 // If rgn has phis add corresponding new edges which has the same | |
| 224 // value as on original uncommon_proj pass. | |
| 225 assert(rgn->in(rgn->req() -1) == if_uct, "new edge should be last"); | |
| 226 bool has_phi = false; | |
| 227 for (DUIterator_Fast imax, i = rgn->fast_outs(imax); i < imax; i++) { | |
| 228 Node* use = rgn->fast_out(i); | |
| 229 if (use->is_Phi() && use->outcnt() > 0) { | |
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230 rehash_node_delayed(use); |
| 2445 | 231 use->add_req(use->in(proj_index)); |
| 232 has_phi = true; | |
| 233 } | |
| 234 } | |
| 235 assert(!has_phi || rgn->req() > 3, "no phis when region is created"); | |
| 236 | |
| 237 return if_cont->as_Proj(); | |
| 238 } | |
| 239 | |
| 240 //--------------------------clone_predicate----------------------- | |
| 241 ProjNode* PhaseIdealLoop::clone_predicate(ProjNode* predicate_proj, Node* new_entry, | |
| 242 Deoptimization::DeoptReason reason, | |
| 243 PhaseIdealLoop* loop_phase, | |
| 244 PhaseIterGVN* igvn) { | |
| 245 ProjNode* new_predicate_proj; | |
| 246 if (loop_phase != NULL) { | |
| 247 new_predicate_proj = loop_phase->create_new_if_for_predicate(predicate_proj, new_entry, reason); | |
| 248 } else { | |
| 249 new_predicate_proj = igvn->create_new_if_for_predicate(predicate_proj, new_entry, reason); | |
| 250 } | |
| 251 IfNode* iff = new_predicate_proj->in(0)->as_If(); | |
| 252 Node* ctrl = iff->in(0); | |
| 253 | |
| 254 // Match original condition since predicate's projections could be swapped. | |
| 255 assert(predicate_proj->in(0)->in(1)->in(1)->Opcode()==Op_Opaque1, "must be"); | |
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256 Node* opq = new (igvn->C) Opaque1Node(igvn->C, predicate_proj->in(0)->in(1)->in(1)->in(1)); |
| 2445 | 257 igvn->C->add_predicate_opaq(opq); |
| 258 | |
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259 Node* bol = new (igvn->C) Conv2BNode(opq); |
| 2445 | 260 if (loop_phase != NULL) { |
| 261 loop_phase->register_new_node(opq, ctrl); | |
| 262 loop_phase->register_new_node(bol, ctrl); | |
| 263 } else { | |
| 264 igvn->register_new_node_with_optimizer(opq); | |
| 265 igvn->register_new_node_with_optimizer(bol); | |
| 266 } | |
| 267 igvn->hash_delete(iff); | |
| 268 iff->set_req(1, bol); | |
| 269 return new_predicate_proj; | |
| 270 } | |
| 271 | |
| 272 | |
| 273 //--------------------------clone_loop_predicates----------------------- | |
| 274 // Interface from IGVN | |
| 3345 | 275 Node* PhaseIterGVN::clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { |
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276 return PhaseIdealLoop::clone_loop_predicates(old_entry, new_entry, clone_limit_check, NULL, this); |
| 2445 | 277 } |
| 278 | |
| 279 // Interface from PhaseIdealLoop | |
| 3345 | 280 Node* PhaseIdealLoop::clone_loop_predicates(Node* old_entry, Node* new_entry, bool clone_limit_check) { |
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281 return clone_loop_predicates(old_entry, new_entry, clone_limit_check, this, &this->_igvn); |
| 2445 | 282 } |
| 283 | |
| 284 // Clone loop predicates to cloned loops (peeled, unswitched, split_if). | |
| 285 Node* PhaseIdealLoop::clone_loop_predicates(Node* old_entry, Node* new_entry, | |
| 3345 | 286 bool clone_limit_check, |
| 2445 | 287 PhaseIdealLoop* loop_phase, |
| 288 PhaseIterGVN* igvn) { | |
| 289 #ifdef ASSERT | |
| 290 if (new_entry == NULL || !(new_entry->is_Proj() || new_entry->is_Region() || new_entry->is_SafePoint())) { | |
| 291 if (new_entry != NULL) | |
| 292 new_entry->dump(); | |
| 293 assert(false, "not IfTrue, IfFalse, Region or SafePoint"); | |
| 294 } | |
| 295 #endif | |
| 296 // Search original predicates | |
| 297 Node* entry = old_entry; | |
| 3345 | 298 ProjNode* limit_check_proj = NULL; |
| 299 if (LoopLimitCheck) { | |
| 300 limit_check_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); | |
| 301 if (limit_check_proj != NULL) { | |
| 302 entry = entry->in(0)->in(0); | |
| 303 } | |
| 304 } | |
| 2445 | 305 if (UseLoopPredicate) { |
| 306 ProjNode* predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); | |
| 307 if (predicate_proj != NULL) { // right pattern that can be used by loop predication | |
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308 // clone predicate |
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309 new_entry = clone_predicate(predicate_proj, new_entry, |
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310 Deoptimization::Reason_predicate, |
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311 loop_phase, igvn); |
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312 assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone predicate"); |
| 2445 | 313 if (TraceLoopPredicate) { |
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314 tty->print("Loop Predicate cloned: "); |
| 2445 | 315 debug_only( new_entry->in(0)->dump(); ) |
| 316 } | |
| 317 } | |
| 318 } | |
| 3345 | 319 if (limit_check_proj != NULL && clone_limit_check) { |
| 320 // Clone loop limit check last to insert it before loop. | |
| 321 // Don't clone a limit check which was already finalized | |
| 322 // for this counted loop (only one limit check is needed). | |
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323 new_entry = clone_predicate(limit_check_proj, new_entry, |
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324 Deoptimization::Reason_loop_limit_check, |
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325 loop_phase, igvn); |
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326 assert(new_entry != NULL && new_entry->is_Proj(), "IfTrue or IfFalse after clone limit check"); |
| 3345 | 327 if (TraceLoopLimitCheck) { |
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328 tty->print("Loop Limit Check cloned: "); |
| 3345 | 329 debug_only( new_entry->in(0)->dump(); ) |
| 330 } | |
| 331 } | |
| 2445 | 332 return new_entry; |
| 333 } | |
| 334 | |
| 335 //--------------------------skip_loop_predicates------------------------------ | |
| 336 // Skip related predicates. | |
| 337 Node* PhaseIdealLoop::skip_loop_predicates(Node* entry) { | |
| 338 Node* predicate = NULL; | |
| 3345 | 339 if (LoopLimitCheck) { |
| 340 predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); | |
| 341 if (predicate != NULL) { | |
| 342 entry = entry->in(0)->in(0); | |
| 343 } | |
| 344 } | |
| 2445 | 345 if (UseLoopPredicate) { |
| 346 predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); | |
| 347 if (predicate != NULL) { // right pattern that can be used by loop predication | |
| 348 IfNode* iff = entry->in(0)->as_If(); | |
| 349 ProjNode* uncommon_proj = iff->proj_out(1 - entry->as_Proj()->_con); | |
| 350 Node* rgn = uncommon_proj->unique_ctrl_out(); | |
| 351 assert(rgn->is_Region() || rgn->is_Call(), "must be a region or call uct"); | |
| 352 entry = entry->in(0)->in(0); | |
| 353 while (entry != NULL && entry->is_Proj() && entry->in(0)->is_If()) { | |
| 354 uncommon_proj = entry->in(0)->as_If()->proj_out(1 - entry->as_Proj()->_con); | |
| 355 if (uncommon_proj->unique_ctrl_out() != rgn) | |
| 356 break; | |
| 357 entry = entry->in(0)->in(0); | |
| 358 } | |
| 359 } | |
| 360 } | |
| 361 return entry; | |
| 362 } | |
| 363 | |
| 364 //--------------------------find_predicate_insertion_point------------------- | |
| 365 // Find a good location to insert a predicate | |
| 366 ProjNode* PhaseIdealLoop::find_predicate_insertion_point(Node* start_c, Deoptimization::DeoptReason reason) { | |
| 367 if (start_c == NULL || !start_c->is_Proj()) | |
| 368 return NULL; | |
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369 if (start_c->as_Proj()->is_uncommon_trap_if_pattern(reason)) { |
| 2445 | 370 return start_c->as_Proj(); |
| 371 } | |
| 372 return NULL; | |
| 373 } | |
| 374 | |
| 375 //--------------------------find_predicate------------------------------------ | |
| 376 // Find a predicate | |
| 377 Node* PhaseIdealLoop::find_predicate(Node* entry) { | |
| 378 Node* predicate = NULL; | |
| 3345 | 379 if (LoopLimitCheck) { |
| 380 predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); | |
| 381 if (predicate != NULL) { // right pattern that can be used by loop predication | |
| 382 return entry; | |
| 383 } | |
| 384 } | |
| 2445 | 385 if (UseLoopPredicate) { |
| 386 predicate = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); | |
| 387 if (predicate != NULL) { // right pattern that can be used by loop predication | |
| 388 return entry; | |
| 389 } | |
| 390 } | |
| 391 return NULL; | |
| 392 } | |
| 393 | |
| 394 //------------------------------Invariance----------------------------------- | |
| 395 // Helper class for loop_predication_impl to compute invariance on the fly and | |
| 396 // clone invariants. | |
| 397 class Invariance : public StackObj { | |
| 398 VectorSet _visited, _invariant; | |
| 399 Node_Stack _stack; | |
| 400 VectorSet _clone_visited; | |
| 401 Node_List _old_new; // map of old to new (clone) | |
| 402 IdealLoopTree* _lpt; | |
| 403 PhaseIdealLoop* _phase; | |
| 404 | |
| 405 // Helper function to set up the invariance for invariance computation | |
| 406 // If n is a known invariant, set up directly. Otherwise, look up the | |
| 407 // the possibility to push n onto the stack for further processing. | |
| 408 void visit(Node* use, Node* n) { | |
| 409 if (_lpt->is_invariant(n)) { // known invariant | |
| 410 _invariant.set(n->_idx); | |
| 411 } else if (!n->is_CFG()) { | |
| 412 Node *n_ctrl = _phase->ctrl_or_self(n); | |
| 413 Node *u_ctrl = _phase->ctrl_or_self(use); // self if use is a CFG | |
| 414 if (_phase->is_dominator(n_ctrl, u_ctrl)) { | |
| 415 _stack.push(n, n->in(0) == NULL ? 1 : 0); | |
| 416 } | |
| 417 } | |
| 418 } | |
| 419 | |
| 420 // Compute invariance for "the_node" and (possibly) all its inputs recursively | |
| 421 // on the fly | |
| 422 void compute_invariance(Node* n) { | |
| 423 assert(_visited.test(n->_idx), "must be"); | |
| 424 visit(n, n); | |
| 425 while (_stack.is_nonempty()) { | |
| 426 Node* n = _stack.node(); | |
| 427 uint idx = _stack.index(); | |
| 428 if (idx == n->req()) { // all inputs are processed | |
| 429 _stack.pop(); | |
| 430 // n is invariant if it's inputs are all invariant | |
| 431 bool all_inputs_invariant = true; | |
| 432 for (uint i = 0; i < n->req(); i++) { | |
| 433 Node* in = n->in(i); | |
| 434 if (in == NULL) continue; | |
| 435 assert(_visited.test(in->_idx), "must have visited input"); | |
| 436 if (!_invariant.test(in->_idx)) { // bad guy | |
| 437 all_inputs_invariant = false; | |
| 438 break; | |
| 439 } | |
| 440 } | |
| 441 if (all_inputs_invariant) { | |
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442 // If n's control is a predicate that was moved out of the |
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443 // loop, it was marked invariant but n is only invariant if |
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444 // it depends only on that test. Otherwise, unless that test |
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445 // is out of the loop, it's not invariant. |
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446 if (n->is_CFG() || n->depends_only_on_test() || n->in(0) == NULL || !_phase->is_member(_lpt, n->in(0))) { |
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447 _invariant.set(n->_idx); // I am a invariant too |
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448 } |
| 2445 | 449 } |
| 450 } else { // process next input | |
| 451 _stack.set_index(idx + 1); | |
| 452 Node* m = n->in(idx); | |
| 453 if (m != NULL && !_visited.test_set(m->_idx)) { | |
| 454 visit(n, m); | |
| 455 } | |
| 456 } | |
| 457 } | |
| 458 } | |
| 459 | |
| 460 // Helper function to set up _old_new map for clone_nodes. | |
| 461 // If n is a known invariant, set up directly ("clone" of n == n). | |
| 462 // Otherwise, push n onto the stack for real cloning. | |
| 463 void clone_visit(Node* n) { | |
| 464 assert(_invariant.test(n->_idx), "must be invariant"); | |
| 465 if (_lpt->is_invariant(n)) { // known invariant | |
| 466 _old_new.map(n->_idx, n); | |
| 467 } else { // to be cloned | |
| 468 assert(!n->is_CFG(), "should not see CFG here"); | |
| 469 _stack.push(n, n->in(0) == NULL ? 1 : 0); | |
| 470 } | |
| 471 } | |
| 472 | |
| 473 // Clone "n" and (possibly) all its inputs recursively | |
| 474 void clone_nodes(Node* n, Node* ctrl) { | |
| 475 clone_visit(n); | |
| 476 while (_stack.is_nonempty()) { | |
| 477 Node* n = _stack.node(); | |
| 478 uint idx = _stack.index(); | |
| 479 if (idx == n->req()) { // all inputs processed, clone n! | |
| 480 _stack.pop(); | |
| 481 // clone invariant node | |
| 482 Node* n_cl = n->clone(); | |
| 483 _old_new.map(n->_idx, n_cl); | |
| 484 _phase->register_new_node(n_cl, ctrl); | |
| 485 for (uint i = 0; i < n->req(); i++) { | |
| 486 Node* in = n_cl->in(i); | |
| 487 if (in == NULL) continue; | |
| 488 n_cl->set_req(i, _old_new[in->_idx]); | |
| 489 } | |
| 490 } else { // process next input | |
| 491 _stack.set_index(idx + 1); | |
| 492 Node* m = n->in(idx); | |
| 493 if (m != NULL && !_clone_visited.test_set(m->_idx)) { | |
| 494 clone_visit(m); // visit the input | |
| 495 } | |
| 496 } | |
| 497 } | |
| 498 } | |
| 499 | |
| 500 public: | |
| 501 Invariance(Arena* area, IdealLoopTree* lpt) : | |
| 502 _lpt(lpt), _phase(lpt->_phase), | |
| 503 _visited(area), _invariant(area), _stack(area, 10 /* guess */), | |
| 504 _clone_visited(area), _old_new(area) | |
| 505 {} | |
| 506 | |
| 507 // Map old to n for invariance computation and clone | |
| 508 void map_ctrl(Node* old, Node* n) { | |
| 509 assert(old->is_CFG() && n->is_CFG(), "must be"); | |
| 510 _old_new.map(old->_idx, n); // "clone" of old is n | |
| 511 _invariant.set(old->_idx); // old is invariant | |
| 512 _clone_visited.set(old->_idx); | |
| 513 } | |
| 514 | |
| 515 // Driver function to compute invariance | |
| 516 bool is_invariant(Node* n) { | |
| 517 if (!_visited.test_set(n->_idx)) | |
| 518 compute_invariance(n); | |
| 519 return (_invariant.test(n->_idx) != 0); | |
| 520 } | |
| 521 | |
| 522 // Driver function to clone invariant | |
| 523 Node* clone(Node* n, Node* ctrl) { | |
| 524 assert(ctrl->is_CFG(), "must be"); | |
| 525 assert(_invariant.test(n->_idx), "must be an invariant"); | |
| 526 if (!_clone_visited.test(n->_idx)) | |
| 527 clone_nodes(n, ctrl); | |
| 528 return _old_new[n->_idx]; | |
| 529 } | |
| 530 }; | |
| 531 | |
| 532 //------------------------------is_range_check_if ----------------------------------- | |
| 533 // Returns true if the predicate of iff is in "scale*iv + offset u< load_range(ptr)" format | |
| 534 // Note: this function is particularly designed for loop predication. We require load_range | |
| 535 // and offset to be loop invariant computed on the fly by "invar" | |
| 536 bool IdealLoopTree::is_range_check_if(IfNode *iff, PhaseIdealLoop *phase, Invariance& invar) const { | |
| 537 if (!is_loop_exit(iff)) { | |
| 538 return false; | |
| 539 } | |
| 540 if (!iff->in(1)->is_Bool()) { | |
| 541 return false; | |
| 542 } | |
| 543 const BoolNode *bol = iff->in(1)->as_Bool(); | |
| 544 if (bol->_test._test != BoolTest::lt) { | |
| 545 return false; | |
| 546 } | |
| 547 if (!bol->in(1)->is_Cmp()) { | |
| 548 return false; | |
| 549 } | |
| 550 const CmpNode *cmp = bol->in(1)->as_Cmp(); | |
| 551 if (cmp->Opcode() != Op_CmpU) { | |
| 552 return false; | |
| 553 } | |
| 554 Node* range = cmp->in(2); | |
| 555 if (range->Opcode() != Op_LoadRange) { | |
| 556 const TypeInt* tint = phase->_igvn.type(range)->isa_int(); | |
| 3345 | 557 if (tint == NULL || tint->empty() || tint->_lo < 0) { |
| 2445 | 558 // Allow predication on positive values that aren't LoadRanges. |
| 559 // This allows optimization of loops where the length of the | |
| 560 // array is a known value and doesn't need to be loaded back | |
| 561 // from the array. | |
| 562 return false; | |
| 563 } | |
| 564 } | |
| 565 if (!invar.is_invariant(range)) { | |
| 566 return false; | |
| 567 } | |
| 568 Node *iv = _head->as_CountedLoop()->phi(); | |
| 569 int scale = 0; | |
| 570 Node *offset = NULL; | |
| 571 if (!phase->is_scaled_iv_plus_offset(cmp->in(1), iv, &scale, &offset)) { | |
| 572 return false; | |
| 573 } | |
| 574 if (offset && !invar.is_invariant(offset)) { // offset must be invariant | |
| 575 return false; | |
| 576 } | |
| 577 return true; | |
| 578 } | |
| 579 | |
| 580 //------------------------------rc_predicate----------------------------------- | |
| 581 // Create a range check predicate | |
| 582 // | |
| 583 // for (i = init; i < limit; i += stride) { | |
| 584 // a[scale*i+offset] | |
| 585 // } | |
| 586 // | |
| 587 // Compute max(scale*i + offset) for init <= i < limit and build the predicate | |
| 588 // as "max(scale*i + offset) u< a.length". | |
| 589 // | |
| 590 // There are two cases for max(scale*i + offset): | |
| 591 // (1) stride*scale > 0 | |
| 592 // max(scale*i + offset) = scale*(limit-stride) + offset | |
| 593 // (2) stride*scale < 0 | |
| 594 // max(scale*i + offset) = scale*init + offset | |
| 3345 | 595 BoolNode* PhaseIdealLoop::rc_predicate(IdealLoopTree *loop, Node* ctrl, |
| 2445 | 596 int scale, Node* offset, |
| 24206 | 597 Node* init, Node* limit, jint stride, |
| 598 Node* range, bool upper, bool &overflow) { | |
| 599 jint con_limit = limit->is_Con() ? limit->get_int() : 0; | |
| 600 jint con_init = init->is_Con() ? init->get_int() : 0; | |
| 601 jint con_offset = offset->is_Con() ? offset->get_int() : 0; | |
| 602 | |
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603 stringStream* predString = NULL; |
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604 if (TraceLoopPredicate) { |
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605 predString = new stringStream(); |
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606 predString->print("rc_predicate "); |
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607 } |
| 2445 | 608 |
| 24206 | 609 overflow = false; |
| 610 Node* max_idx_expr = NULL; | |
| 611 const TypeInt* idx_type = TypeInt::INT; | |
| 612 if ((stride > 0) == (scale > 0) == upper) { | |
| 613 if (TraceLoopPredicate) { | |
| 614 predString->print(limit->is_Con() ? "(%d " : "(limit ", con_limit); | |
| 615 predString->print("- %d) ", stride); | |
| 616 } | |
| 617 // Check if (limit - stride) may overflow | |
| 618 const TypeInt* limit_type = _igvn.type(limit)->isa_int(); | |
| 619 jint limit_lo = limit_type->_lo; | |
| 620 jint limit_hi = limit_type->_hi; | |
| 621 jint res_lo = limit_lo - stride; | |
| 622 jint res_hi = limit_hi - stride; | |
| 623 if ((stride > 0 && (res_lo < limit_lo)) || | |
| 624 (stride < 0 && (res_hi > limit_hi))) { | |
| 625 // No overflow possible | |
| 626 ConINode* con_stride = _igvn.intcon(stride); | |
| 627 set_ctrl(con_stride, C->root()); | |
| 628 max_idx_expr = new (C) SubINode(limit, con_stride); | |
| 629 idx_type = TypeInt::make(limit_lo - stride, limit_hi - stride, limit_type->_widen); | |
| 3345 | 630 } else { |
| 24206 | 631 // May overflow |
| 632 overflow = true; | |
| 633 limit = new (C) ConvI2LNode(limit); | |
| 634 register_new_node(limit, ctrl); | |
| 635 ConLNode* con_stride = _igvn.longcon(stride); | |
| 636 set_ctrl(con_stride, C->root()); | |
| 637 max_idx_expr = new (C) SubLNode(limit, con_stride); | |
| 3345 | 638 } |
| 24206 | 639 register_new_node(max_idx_expr, ctrl); |
| 2445 | 640 } else { |
| 24206 | 641 if (TraceLoopPredicate) { |
| 642 predString->print(init->is_Con() ? "%d " : "init ", con_init); | |
| 643 } | |
| 644 idx_type = _igvn.type(init)->isa_int(); | |
| 645 max_idx_expr = init; | |
| 2445 | 646 } |
| 647 | |
| 648 if (scale != 1) { | |
| 649 ConNode* con_scale = _igvn.intcon(scale); | |
| 24206 | 650 set_ctrl(con_scale, C->root()); |
| 651 if (TraceLoopPredicate) { | |
| 652 predString->print("* %d ", scale); | |
| 653 } | |
| 654 // Check if (scale * max_idx_expr) may overflow | |
| 655 const TypeInt* scale_type = TypeInt::make(scale); | |
| 656 MulINode* mul = new (C) MulINode(max_idx_expr, con_scale); | |
| 657 idx_type = (TypeInt*)mul->mul_ring(idx_type, scale_type); | |
| 658 if (overflow || TypeInt::INT->higher_equal(idx_type)) { | |
| 659 // May overflow | |
| 660 mul->destruct(); | |
| 661 if (!overflow) { | |
| 662 max_idx_expr = new (C) ConvI2LNode(max_idx_expr); | |
| 663 register_new_node(max_idx_expr, ctrl); | |
| 664 } | |
| 665 overflow = true; | |
| 666 con_scale = _igvn.longcon(scale); | |
| 667 set_ctrl(con_scale, C->root()); | |
| 668 max_idx_expr = new (C) MulLNode(max_idx_expr, con_scale); | |
| 669 } else { | |
| 670 // No overflow possible | |
| 671 max_idx_expr = mul; | |
| 672 } | |
| 2445 | 673 register_new_node(max_idx_expr, ctrl); |
| 674 } | |
| 675 | |
| 24206 | 676 if (offset && (!offset->is_Con() || con_offset != 0)){ |
| 677 if (TraceLoopPredicate) { | |
| 678 predString->print(offset->is_Con() ? "+ %d " : "+ offset", con_offset); | |
| 679 } | |
| 680 // Check if (max_idx_expr + offset) may overflow | |
| 681 const TypeInt* offset_type = _igvn.type(offset)->isa_int(); | |
| 682 jint lo = idx_type->_lo + offset_type->_lo; | |
| 683 jint hi = idx_type->_hi + offset_type->_hi; | |
| 684 if (overflow || (lo > hi) || | |
| 685 ((idx_type->_lo & offset_type->_lo) < 0 && lo >= 0) || | |
| 686 ((~(idx_type->_hi | offset_type->_hi)) < 0 && hi < 0)) { | |
| 687 // May overflow | |
| 688 if (!overflow) { | |
| 689 max_idx_expr = new (C) ConvI2LNode(max_idx_expr); | |
| 690 register_new_node(max_idx_expr, ctrl); | |
| 691 } | |
| 692 overflow = true; | |
| 693 offset = new (C) ConvI2LNode(offset); | |
| 694 register_new_node(offset, ctrl); | |
| 695 max_idx_expr = new (C) AddLNode(max_idx_expr, offset); | |
| 696 } else { | |
| 697 // No overflow possible | |
| 698 max_idx_expr = new (C) AddINode(max_idx_expr, offset); | |
| 699 } | |
| 2445 | 700 register_new_node(max_idx_expr, ctrl); |
| 701 } | |
| 702 | |
| 24206 | 703 CmpNode* cmp = NULL; |
| 704 if (overflow) { | |
| 705 // Integer expressions may overflow, do long comparison | |
| 706 range = new (C) ConvI2LNode(range); | |
| 707 register_new_node(range, ctrl); | |
| 708 if (!Matcher::has_match_rule(Op_CmpUL)) { | |
| 709 // We don't support unsigned long comparisons. Set 'max_idx_expr' | |
| 710 // to max_julong if < 0 to make the signed comparison fail. | |
| 711 ConINode* sign_pos = _igvn.intcon(BitsPerLong - 1); | |
| 712 set_ctrl(sign_pos, C->root()); | |
| 713 Node* sign_bit_mask = new (C) RShiftLNode(max_idx_expr, sign_pos); | |
| 714 register_new_node(sign_bit_mask, ctrl); | |
| 715 // OR with sign bit to set all bits to 1 if negative (otherwise no change) | |
| 716 max_idx_expr = new (C) OrLNode(max_idx_expr, sign_bit_mask); | |
| 717 register_new_node(max_idx_expr, ctrl); | |
| 718 // AND with 0x7ff... to unset the sign bit | |
| 719 ConLNode* remove_sign_mask = _igvn.longcon(max_jlong); | |
| 720 set_ctrl(remove_sign_mask, C->root()); | |
| 721 max_idx_expr = new (C) AndLNode(max_idx_expr, remove_sign_mask); | |
| 722 register_new_node(max_idx_expr, ctrl); | |
| 723 | |
| 724 cmp = new (C) CmpLNode(max_idx_expr, range); | |
| 725 } else { | |
| 726 cmp = new (C) CmpULNode(max_idx_expr, range); | |
| 727 } | |
| 728 } else { | |
| 729 cmp = new (C) CmpUNode(max_idx_expr, range); | |
| 730 } | |
| 2445 | 731 register_new_node(cmp, ctrl); |
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732 BoolNode* bol = new (C) BoolNode(cmp, BoolTest::lt); |
| 2445 | 733 register_new_node(bol, ctrl); |
| 734 | |
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735 if (TraceLoopPredicate) { |
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736 predString->print_cr("<u range"); |
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737 tty->print("%s", predString->as_string()); |
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738 } |
| 2445 | 739 return bol; |
| 740 } | |
| 741 | |
| 742 //------------------------------ loop_predication_impl-------------------------- | |
| 743 // Insert loop predicates for null checks and range checks | |
| 744 bool PhaseIdealLoop::loop_predication_impl(IdealLoopTree *loop) { | |
| 745 if (!UseLoopPredicate) return false; | |
| 746 | |
| 747 if (!loop->_head->is_Loop()) { | |
| 748 // Could be a simple region when irreducible loops are present. | |
| 749 return false; | |
| 750 } | |
| 3345 | 751 LoopNode* head = loop->_head->as_Loop(); |
| 2445 | 752 |
| 3345 | 753 if (head->unique_ctrl_out()->Opcode() == Op_NeverBranch) { |
| 2445 | 754 // do nothing for infinite loops |
| 755 return false; | |
| 756 } | |
| 757 | |
| 758 CountedLoopNode *cl = NULL; | |
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759 if (head->is_valid_counted_loop()) { |
| 3345 | 760 cl = head->as_CountedLoop(); |
| 2445 | 761 // do nothing for iteration-splitted loops |
| 762 if (!cl->is_normal_loop()) return false; | |
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763 // Avoid RCE if Counted loop's test is '!='. |
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764 BoolTest::mask bt = cl->loopexit()->test_trip(); |
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765 if (bt != BoolTest::lt && bt != BoolTest::gt) |
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766 cl = NULL; |
| 2445 | 767 } |
| 768 | |
| 3345 | 769 Node* entry = head->in(LoopNode::EntryControl); |
| 770 ProjNode *predicate_proj = NULL; | |
| 771 // Loop limit check predicate should be near the loop. | |
| 772 if (LoopLimitCheck) { | |
| 773 predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_loop_limit_check); | |
| 774 if (predicate_proj != NULL) | |
| 775 entry = predicate_proj->in(0)->in(0); | |
| 776 } | |
| 2445 | 777 |
| 3345 | 778 predicate_proj = find_predicate_insertion_point(entry, Deoptimization::Reason_predicate); |
| 2445 | 779 if (!predicate_proj) { |
| 780 #ifndef PRODUCT | |
| 781 if (TraceLoopPredicate) { | |
| 782 tty->print("missing predicate:"); | |
| 783 loop->dump_head(); | |
| 3345 | 784 head->dump(1); |
| 2445 | 785 } |
| 786 #endif | |
| 787 return false; | |
| 788 } | |
| 789 ConNode* zero = _igvn.intcon(0); | |
| 790 set_ctrl(zero, C->root()); | |
| 791 | |
| 792 ResourceArea *area = Thread::current()->resource_area(); | |
| 793 Invariance invar(area, loop); | |
| 794 | |
| 795 // Create list of if-projs such that a newer proj dominates all older | |
| 796 // projs in the list, and they all dominate loop->tail() | |
| 797 Node_List if_proj_list(area); | |
| 798 Node *current_proj = loop->tail(); //start from tail | |
| 799 while (current_proj != head) { | |
| 800 if (loop == get_loop(current_proj) && // still in the loop ? | |
| 801 current_proj->is_Proj() && // is a projection ? | |
| 802 current_proj->in(0)->Opcode() == Op_If) { // is a if projection ? | |
| 803 if_proj_list.push(current_proj); | |
| 804 } | |
| 805 current_proj = idom(current_proj); | |
| 806 } | |
| 807 | |
| 808 bool hoisted = false; // true if at least one proj is promoted | |
| 809 while (if_proj_list.size() > 0) { | |
| 810 // Following are changed to nonnull when a predicate can be hoisted | |
| 811 ProjNode* new_predicate_proj = NULL; | |
| 812 | |
| 813 ProjNode* proj = if_proj_list.pop()->as_Proj(); | |
| 814 IfNode* iff = proj->in(0)->as_If(); | |
| 815 | |
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816 if (!proj->is_uncommon_trap_if_pattern(Deoptimization::Reason_none)) { |
| 2445 | 817 if (loop->is_loop_exit(iff)) { |
| 818 // stop processing the remaining projs in the list because the execution of them | |
| 819 // depends on the condition of "iff" (iff->in(1)). | |
| 820 break; | |
| 821 } else { | |
| 822 // Both arms are inside the loop. There are two cases: | |
| 823 // (1) there is one backward branch. In this case, any remaining proj | |
| 824 // in the if_proj list post-dominates "iff". So, the condition of "iff" | |
| 825 // does not determine the execution the remining projs directly, and we | |
| 826 // can safely continue. | |
| 827 // (2) both arms are forwarded, i.e. a diamond shape. In this case, "proj" | |
| 828 // does not dominate loop->tail(), so it can not be in the if_proj list. | |
| 829 continue; | |
| 830 } | |
| 831 } | |
| 832 | |
| 833 Node* test = iff->in(1); | |
| 834 if (!test->is_Bool()){ //Conv2B, ... | |
| 835 continue; | |
| 836 } | |
| 837 BoolNode* bol = test->as_Bool(); | |
| 838 if (invar.is_invariant(bol)) { | |
| 839 // Invariant test | |
| 840 new_predicate_proj = create_new_if_for_predicate(predicate_proj, NULL, | |
| 841 Deoptimization::Reason_predicate); | |
| 842 Node* ctrl = new_predicate_proj->in(0)->as_If()->in(0); | |
| 843 BoolNode* new_predicate_bol = invar.clone(bol, ctrl)->as_Bool(); | |
| 844 | |
| 845 // Negate test if necessary | |
| 846 bool negated = false; | |
| 847 if (proj->_con != predicate_proj->_con) { | |
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848 new_predicate_bol = new (C) BoolNode(new_predicate_bol->in(1), new_predicate_bol->_test.negate()); |
| 2445 | 849 register_new_node(new_predicate_bol, ctrl); |
| 850 negated = true; | |
| 851 } | |
| 852 IfNode* new_predicate_iff = new_predicate_proj->in(0)->as_If(); | |
| 853 _igvn.hash_delete(new_predicate_iff); | |
| 854 new_predicate_iff->set_req(1, new_predicate_bol); | |
| 855 #ifndef PRODUCT | |
| 856 if (TraceLoopPredicate) { | |
| 857 tty->print("Predicate invariant if%s: %d ", negated ? " negated" : "", new_predicate_iff->_idx); | |
| 858 loop->dump_head(); | |
| 859 } else if (TraceLoopOpts) { | |
| 860 tty->print("Predicate IC "); | |
| 861 loop->dump_head(); | |
| 862 } | |
| 863 #endif | |
| 10278 | 864 } else if ((cl != NULL) && (proj->_con == predicate_proj->_con) && |
| 865 loop->is_range_check_if(iff, this, invar)) { | |
| 2445 | 866 |
| 867 // Range check for counted loops | |
| 868 const Node* cmp = bol->in(1)->as_Cmp(); | |
| 869 Node* idx = cmp->in(1); | |
| 870 assert(!invar.is_invariant(idx), "index is variant"); | |
| 871 Node* rng = cmp->in(2); | |
| 3345 | 872 assert(rng->Opcode() == Op_LoadRange || _igvn.type(rng)->is_int() >= 0, "must be"); |
| 2445 | 873 assert(invar.is_invariant(rng), "range must be invariant"); |
| 874 int scale = 1; | |
| 875 Node* offset = zero; | |
| 876 bool ok = is_scaled_iv_plus_offset(idx, cl->phi(), &scale, &offset); | |
| 877 assert(ok, "must be index expression"); | |
| 878 | |
| 879 Node* init = cl->init_trip(); | |
| 24206 | 880 // Limit is not exact. |
| 881 // Calculate exact limit here. | |
| 882 // Note, counted loop's test is '<' or '>'. | |
| 883 Node* limit = exact_limit(loop); | |
| 884 int stride = cl->stride()->get_int(); | |
| 2445 | 885 |
| 886 // Build if's for the upper and lower bound tests. The | |
| 887 // lower_bound test will dominate the upper bound test and all | |
| 888 // cloned or created nodes will use the lower bound test as | |
| 889 // their declared control. | |
| 890 ProjNode* lower_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate); | |
| 891 ProjNode* upper_bound_proj = create_new_if_for_predicate(predicate_proj, NULL, Deoptimization::Reason_predicate); | |
| 892 assert(upper_bound_proj->in(0)->as_If()->in(0) == lower_bound_proj, "should dominate"); | |
| 893 Node *ctrl = lower_bound_proj->in(0)->as_If()->in(0); | |
| 894 | |
| 895 // Perform cloning to keep Invariance state correct since the | |
| 896 // late schedule will place invariant things in the loop. | |
| 897 rng = invar.clone(rng, ctrl); | |
| 898 if (offset && offset != zero) { | |
| 899 assert(invar.is_invariant(offset), "offset must be loop invariant"); | |
| 900 offset = invar.clone(offset, ctrl); | |
| 901 } | |
| 24206 | 902 // If predicate expressions may overflow in the integer range, longs are used. |
| 903 bool overflow = false; | |
| 2445 | 904 |
| 905 // Test the lower bound | |
| 24206 | 906 Node* lower_bound_bol = rc_predicate(loop, ctrl, scale, offset, init, limit, stride, rng, false, overflow); |
| 2445 | 907 IfNode* lower_bound_iff = lower_bound_proj->in(0)->as_If(); |
| 908 _igvn.hash_delete(lower_bound_iff); | |
| 909 lower_bound_iff->set_req(1, lower_bound_bol); | |
| 910 if (TraceLoopPredicate) tty->print_cr("lower bound check if: %d", lower_bound_iff->_idx); | |
| 911 | |
| 912 // Test the upper bound | |
| 24206 | 913 Node* upper_bound_bol = rc_predicate(loop, lower_bound_proj, scale, offset, init, limit, stride, rng, true, overflow); |
| 2445 | 914 IfNode* upper_bound_iff = upper_bound_proj->in(0)->as_If(); |
| 915 _igvn.hash_delete(upper_bound_iff); | |
| 916 upper_bound_iff->set_req(1, upper_bound_bol); | |
| 917 if (TraceLoopPredicate) tty->print_cr("upper bound check if: %d", lower_bound_iff->_idx); | |
| 918 | |
| 919 // Fall through into rest of the clean up code which will move | |
| 920 // any dependent nodes onto the upper bound test. | |
| 921 new_predicate_proj = upper_bound_proj; | |
| 922 | |
| 923 #ifndef PRODUCT | |
| 924 if (TraceLoopOpts && !TraceLoopPredicate) { | |
| 925 tty->print("Predicate RC "); | |
| 926 loop->dump_head(); | |
| 927 } | |
| 928 #endif | |
| 929 } else { | |
| 930 // Loop variant check (for example, range check in non-counted loop) | |
| 931 // with uncommon trap. | |
| 932 continue; | |
| 933 } | |
| 934 assert(new_predicate_proj != NULL, "sanity"); | |
| 935 // Success - attach condition (new_predicate_bol) to predicate if | |
| 936 invar.map_ctrl(proj, new_predicate_proj); // so that invariance test can be appropriate | |
| 937 | |
| 938 // Eliminate the old If in the loop body | |
| 939 dominated_by( new_predicate_proj, iff, proj->_con != new_predicate_proj->_con ); | |
| 940 | |
| 941 hoisted = true; | |
| 942 C->set_major_progress(); | |
| 943 } // end while | |
| 944 | |
| 945 #ifndef PRODUCT | |
| 946 // report that the loop predication has been actually performed | |
| 947 // for this loop | |
| 948 if (TraceLoopPredicate && hoisted) { | |
| 949 tty->print("Loop Predication Performed:"); | |
| 950 loop->dump_head(); | |
| 951 } | |
| 952 #endif | |
| 953 | |
| 954 return hoisted; | |
| 955 } | |
| 956 | |
| 957 //------------------------------loop_predication-------------------------------- | |
| 958 // driver routine for loop predication optimization | |
| 959 bool IdealLoopTree::loop_predication( PhaseIdealLoop *phase) { | |
| 960 bool hoisted = false; | |
| 961 // Recursively promote predicates | |
| 962 if (_child) { | |
| 963 hoisted = _child->loop_predication( phase); | |
| 964 } | |
| 965 | |
| 966 // self | |
| 967 if (!_irreducible && !tail()->is_top()) { | |
| 968 hoisted |= phase->loop_predication_impl(this); | |
| 969 } | |
| 970 | |
| 971 if (_next) { //sibling | |
| 972 hoisted |= _next->loop_predication( phase); | |
| 973 } | |
| 974 | |
| 975 return hoisted; | |
| 976 } |