1 /* 2 * Copyright (c) 2000, 2025, 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 "ci/ciTypeFlow.hpp" 26 #include "memory/allocation.inline.hpp" 27 #include "memory/resourceArea.hpp" 28 #include "opto/addnode.hpp" 29 #include "opto/castnode.hpp" 30 #include "opto/cfgnode.hpp" 31 #include "opto/connode.hpp" 32 #include "opto/loopnode.hpp" 33 #include "opto/phaseX.hpp" 34 #include "opto/predicates_enums.hpp" 35 #include "opto/rootnode.hpp" 36 #include "opto/runtime.hpp" 37 #include "opto/subnode.hpp" 38 #include "opto/subtypenode.hpp" 39 40 // Portions of code courtesy of Clifford Click 41 42 // Optimization - Graph Style 43 44 45 #ifndef PRODUCT 46 extern uint explicit_null_checks_elided; 47 #endif 48 49 IfNode::IfNode(Node* control, Node* bol, float p, float fcnt) 50 : MultiBranchNode(2), 51 _prob(p), 52 _fcnt(fcnt), 53 _assertion_predicate_type(AssertionPredicateType::None) { 54 init_node(control, bol); 55 } 56 57 IfNode::IfNode(Node* control, Node* bol, float p, float fcnt, AssertionPredicateType assertion_predicate_type) 58 : MultiBranchNode(2), 59 _prob(p), 60 _fcnt(fcnt), 61 _assertion_predicate_type(assertion_predicate_type) { 62 init_node(control, bol); 63 } 64 65 //============================================================================= 66 //------------------------------Value------------------------------------------ 67 // Return a tuple for whichever arm of the IF is reachable 68 const Type* IfNode::Value(PhaseGVN* phase) const { 69 if( !in(0) ) return Type::TOP; 70 if( phase->type(in(0)) == Type::TOP ) 71 return Type::TOP; 72 const Type *t = phase->type(in(1)); 73 if( t == Type::TOP ) // data is undefined 74 return TypeTuple::IFNEITHER; // unreachable altogether 75 if( t == TypeInt::ZERO ) // zero, or false 76 return TypeTuple::IFFALSE; // only false branch is reachable 77 if( t == TypeInt::ONE ) // 1, or true 78 return TypeTuple::IFTRUE; // only true branch is reachable 79 assert( t == TypeInt::BOOL, "expected boolean type" ); 80 81 return TypeTuple::IFBOTH; // No progress 82 } 83 84 const RegMask &IfNode::out_RegMask() const { 85 return RegMask::Empty; 86 } 87 88 //------------------------------split_if--------------------------------------- 89 // Look for places where we merge constants, then test on the merged value. 90 // If the IF test will be constant folded on the path with the constant, we 91 // win by splitting the IF to before the merge point. 92 static Node* split_if(IfNode *iff, PhaseIterGVN *igvn) { 93 // I could be a lot more general here, but I'm trying to squeeze this 94 // in before the Christmas '98 break so I'm gonna be kinda restrictive 95 // on the patterns I accept. CNC 96 97 // Look for a compare of a constant and a merged value 98 Node *i1 = iff->in(1); 99 if( !i1->is_Bool() ) return nullptr; 100 BoolNode *b = i1->as_Bool(); 101 Node *cmp = b->in(1); 102 if( !cmp->is_Cmp() ) return nullptr; 103 i1 = cmp->in(1); 104 if( i1 == nullptr || !i1->is_Phi() ) return nullptr; 105 PhiNode *phi = i1->as_Phi(); 106 Node *con2 = cmp->in(2); 107 if( !con2->is_Con() ) return nullptr; 108 // See that the merge point contains some constants 109 Node *con1=nullptr; 110 uint i4; 111 RegionNode* phi_region = phi->region(); 112 for (i4 = 1; i4 < phi->req(); i4++ ) { 113 con1 = phi->in(i4); 114 // Do not optimize partially collapsed merges 115 if (con1 == nullptr || phi_region->in(i4) == nullptr || igvn->type(phi_region->in(i4)) == Type::TOP) { 116 igvn->_worklist.push(iff); 117 return nullptr; 118 } 119 if( con1->is_Con() ) break; // Found a constant 120 // Also allow null-vs-not-null checks 121 const TypePtr *tp = igvn->type(con1)->isa_ptr(); 122 if( tp && tp->_ptr == TypePtr::NotNull ) 123 break; 124 } 125 if( i4 >= phi->req() ) return nullptr; // Found no constants 126 127 igvn->C->set_has_split_ifs(true); // Has chance for split-if 128 129 // Make sure that the compare can be constant folded away 130 Node *cmp2 = cmp->clone(); 131 cmp2->set_req(1,con1); 132 cmp2->set_req(2,con2); 133 const Type *t = cmp2->Value(igvn); 134 // This compare is dead, so whack it! 135 igvn->remove_dead_node(cmp2); 136 if( !t->singleton() ) return nullptr; 137 138 // No intervening control, like a simple Call 139 Node* r = iff->in(0); 140 if (!r->is_Region() || r->is_Loop() || phi_region != r || r->as_Region()->is_copy()) { 141 return nullptr; 142 } 143 144 // No other users of the cmp/bool 145 if (b->outcnt() != 1 || cmp->outcnt() != 1) { 146 //tty->print_cr("many users of cmp/bool"); 147 return nullptr; 148 } 149 150 // Make sure we can determine where all the uses of merged values go 151 for (DUIterator_Fast jmax, j = r->fast_outs(jmax); j < jmax; j++) { 152 Node* u = r->fast_out(j); 153 if( u == r ) continue; 154 if( u == iff ) continue; 155 if( u->outcnt() == 0 ) continue; // use is dead & ignorable 156 if( !u->is_Phi() ) { 157 /* 158 if( u->is_Start() ) { 159 tty->print_cr("Region has inlined start use"); 160 } else { 161 tty->print_cr("Region has odd use"); 162 u->dump(2); 163 }*/ 164 return nullptr; 165 } 166 if( u != phi ) { 167 // CNC - do not allow any other merged value 168 //tty->print_cr("Merging another value"); 169 //u->dump(2); 170 return nullptr; 171 } 172 // Make sure we can account for all Phi uses 173 for (DUIterator_Fast kmax, k = u->fast_outs(kmax); k < kmax; k++) { 174 Node* v = u->fast_out(k); // User of the phi 175 // CNC - Allow only really simple patterns. 176 // In particular I disallow AddP of the Phi, a fairly common pattern 177 if (v == cmp) continue; // The compare is OK 178 if (v->is_ConstraintCast()) { 179 // If the cast is derived from data flow edges, it may not have a control edge. 180 // If so, it should be safe to split. But follow-up code can not deal with 181 // this (l. 359). So skip. 182 if (v->in(0) == nullptr) { 183 return nullptr; 184 } 185 if (v->in(0)->in(0) == iff) { 186 continue; // CastPP/II of the IfNode is OK 187 } 188 } 189 // Disabled following code because I cannot tell if exactly one 190 // path dominates without a real dominator check. CNC 9/9/1999 191 //uint vop = v->Opcode(); 192 //if( vop == Op_Phi ) { // Phi from another merge point might be OK 193 // Node *r = v->in(0); // Get controlling point 194 // if( !r ) return nullptr; // Degraded to a copy 195 // // Find exactly one path in (either True or False doms, but not IFF) 196 // int cnt = 0; 197 // for( uint i = 1; i < r->req(); i++ ) 198 // if( r->in(i) && r->in(i)->in(0) == iff ) 199 // cnt++; 200 // if( cnt == 1 ) continue; // Exactly one of True or False guards Phi 201 //} 202 if( !v->is_Call() ) { 203 /* 204 if( v->Opcode() == Op_AddP ) { 205 tty->print_cr("Phi has AddP use"); 206 } else if( v->Opcode() == Op_CastPP ) { 207 tty->print_cr("Phi has CastPP use"); 208 } else if( v->Opcode() == Op_CastII ) { 209 tty->print_cr("Phi has CastII use"); 210 } else { 211 tty->print_cr("Phi has use I can't be bothered with"); 212 } 213 */ 214 } 215 return nullptr; 216 217 /* CNC - Cut out all the fancy acceptance tests 218 // Can we clone this use when doing the transformation? 219 // If all uses are from Phis at this merge or constants, then YES. 220 if( !v->in(0) && v != cmp ) { 221 tty->print_cr("Phi has free-floating use"); 222 v->dump(2); 223 return nullptr; 224 } 225 for( uint l = 1; l < v->req(); l++ ) { 226 if( (!v->in(l)->is_Phi() || v->in(l)->in(0) != r) && 227 !v->in(l)->is_Con() ) { 228 tty->print_cr("Phi has use"); 229 v->dump(2); 230 return nullptr; 231 } // End of if Phi-use input is neither Phi nor Constant 232 } // End of for all inputs to Phi-use 233 */ 234 } // End of for all uses of Phi 235 } // End of for all uses of Region 236 237 // Only do this if the IF node is in a sane state 238 if (iff->outcnt() != 2) 239 return nullptr; 240 241 // Got a hit! Do the Mondo Hack! 242 // 243 //ABC a1c def ghi B 1 e h A C a c d f g i 244 // R - Phi - Phi - Phi Rc - Phi - Phi - Phi Rx - Phi - Phi - Phi 245 // cmp - 2 cmp - 2 cmp - 2 246 // bool bool_c bool_x 247 // if if_c if_x 248 // T F T F T F 249 // ..s.. ..t .. ..s.. ..t.. ..s.. ..t.. 250 // 251 // Split the paths coming into the merge point into 2 separate groups of 252 // merges. On the left will be all the paths feeding constants into the 253 // Cmp's Phi. On the right will be the remaining paths. The Cmp's Phi 254 // will fold up into a constant; this will let the Cmp fold up as well as 255 // all the control flow. Below the original IF we have 2 control 256 // dependent regions, 's' and 't'. Now we will merge the two paths 257 // just prior to 's' and 't' from the two IFs. At least 1 path (and quite 258 // likely 2 or more) will promptly constant fold away. 259 PhaseGVN *phase = igvn; 260 261 // Make a region merging constants and a region merging the rest 262 uint req_c = 0; 263 for (uint ii = 1; ii < r->req(); ii++) { 264 if (phi->in(ii) == con1) { 265 req_c++; 266 } 267 if (Node::may_be_loop_entry(r->in(ii))) { 268 // Bail out if splitting through a region with a Parse Predicate input (could 269 // also be a loop header before loop opts creates a LoopNode for it). 270 return nullptr; 271 } 272 } 273 274 // If all the defs of the phi are the same constant, we already have the desired end state. 275 // Skip the split that would create empty phi and region nodes. 276 if ((r->req() - req_c) == 1) { 277 return nullptr; 278 } 279 280 // At this point we know that we can apply the split if optimization. If the region is still on the worklist, 281 // we should wait until it is processed. The region might be removed which makes this optimization redundant. 282 // This also avoids the creation of dead data loops when rewiring data nodes below when a region is dying. 283 if (igvn->_worklist.member(r)) { 284 igvn->_worklist.push(iff); // retry split if later again 285 return nullptr; 286 } 287 288 Node *region_c = new RegionNode(req_c + 1); 289 Node *phi_c = con1; 290 uint len = r->req(); 291 Node *region_x = new RegionNode(len - req_c); 292 Node *phi_x = PhiNode::make_blank(region_x, phi); 293 for (uint i = 1, i_c = 1, i_x = 1; i < len; i++) { 294 if (phi->in(i) == con1) { 295 region_c->init_req( i_c++, r ->in(i) ); 296 } else { 297 region_x->init_req( i_x, r ->in(i) ); 298 phi_x ->init_req( i_x++, phi->in(i) ); 299 } 300 } 301 302 // Register the new RegionNodes but do not transform them. Cannot 303 // transform until the entire Region/Phi conglomerate has been hacked 304 // as a single huge transform. 305 igvn->register_new_node_with_optimizer( region_c ); 306 igvn->register_new_node_with_optimizer( region_x ); 307 // Prevent the untimely death of phi_x. Currently he has no uses. He is 308 // about to get one. If this only use goes away, then phi_x will look dead. 309 // However, he will be picking up some more uses down below. 310 Node *hook = new Node(4); 311 hook->init_req(0, phi_x); 312 hook->init_req(1, phi_c); 313 phi_x = phase->transform( phi_x ); 314 315 // Make the compare 316 Node *cmp_c = phase->makecon(t); 317 Node *cmp_x = cmp->clone(); 318 cmp_x->set_req(1,phi_x); 319 cmp_x->set_req(2,con2); 320 cmp_x = phase->transform(cmp_x); 321 // Make the bool 322 Node *b_c = phase->transform(new BoolNode(cmp_c,b->_test._test)); 323 Node *b_x = phase->transform(new BoolNode(cmp_x,b->_test._test)); 324 // Make the IfNode 325 IfNode* iff_c = iff->clone()->as_If(); 326 iff_c->set_req(0, region_c); 327 iff_c->set_req(1, b_c); 328 igvn->set_type_bottom(iff_c); 329 igvn->_worklist.push(iff_c); 330 hook->init_req(2, iff_c); 331 332 IfNode* iff_x = iff->clone()->as_If(); 333 iff_x->set_req(0, region_x); 334 iff_x->set_req(1, b_x); 335 igvn->set_type_bottom(iff_x); 336 igvn->_worklist.push(iff_x); 337 hook->init_req(3, iff_x); 338 339 // Make the true/false arms 340 Node *iff_c_t = phase->transform(new IfTrueNode (iff_c)); 341 Node *iff_c_f = phase->transform(new IfFalseNode(iff_c)); 342 Node *iff_x_t = phase->transform(new IfTrueNode (iff_x)); 343 Node *iff_x_f = phase->transform(new IfFalseNode(iff_x)); 344 345 // Merge the TRUE paths 346 Node *region_s = new RegionNode(3); 347 igvn->_worklist.push(region_s); 348 region_s->init_req(1, iff_c_t); 349 region_s->init_req(2, iff_x_t); 350 igvn->register_new_node_with_optimizer( region_s ); 351 352 // Merge the FALSE paths 353 Node *region_f = new RegionNode(3); 354 igvn->_worklist.push(region_f); 355 region_f->init_req(1, iff_c_f); 356 region_f->init_req(2, iff_x_f); 357 igvn->register_new_node_with_optimizer( region_f ); 358 359 igvn->hash_delete(cmp);// Remove soon-to-be-dead node from hash table. 360 cmp->set_req(1,nullptr); // Whack the inputs to cmp because it will be dead 361 cmp->set_req(2,nullptr); 362 // Check for all uses of the Phi and give them a new home. 363 // The 'cmp' got cloned, but CastPP/IIs need to be moved. 364 Node *phi_s = nullptr; // do not construct unless needed 365 Node *phi_f = nullptr; // do not construct unless needed 366 for (DUIterator_Last i2min, i2 = phi->last_outs(i2min); i2 >= i2min; --i2) { 367 Node* v = phi->last_out(i2);// User of the phi 368 igvn->rehash_node_delayed(v); // Have to fixup other Phi users 369 uint vop = v->Opcode(); 370 Node *proj = nullptr; 371 if( vop == Op_Phi ) { // Remote merge point 372 Node *r = v->in(0); 373 for (uint i3 = 1; i3 < r->req(); i3++) 374 if (r->in(i3) && r->in(i3)->in(0) == iff) { 375 proj = r->in(i3); 376 break; 377 } 378 } else if( v->is_ConstraintCast() ) { 379 proj = v->in(0); // Controlling projection 380 } else { 381 assert( 0, "do not know how to handle this guy" ); 382 } 383 guarantee(proj != nullptr, "sanity"); 384 385 Node *proj_path_data, *proj_path_ctrl; 386 if( proj->Opcode() == Op_IfTrue ) { 387 if( phi_s == nullptr ) { 388 // Only construct phi_s if needed, otherwise provides 389 // interfering use. 390 phi_s = PhiNode::make_blank(region_s,phi); 391 phi_s->init_req( 1, phi_c ); 392 phi_s->init_req( 2, phi_x ); 393 hook->add_req(phi_s); 394 phi_s = phase->transform(phi_s); 395 } 396 proj_path_data = phi_s; 397 proj_path_ctrl = region_s; 398 } else { 399 if( phi_f == nullptr ) { 400 // Only construct phi_f if needed, otherwise provides 401 // interfering use. 402 phi_f = PhiNode::make_blank(region_f,phi); 403 phi_f->init_req( 1, phi_c ); 404 phi_f->init_req( 2, phi_x ); 405 hook->add_req(phi_f); 406 phi_f = phase->transform(phi_f); 407 } 408 proj_path_data = phi_f; 409 proj_path_ctrl = region_f; 410 } 411 412 // Fixup 'v' for for the split 413 if( vop == Op_Phi ) { // Remote merge point 414 uint i; 415 for( i = 1; i < v->req(); i++ ) 416 if( v->in(i) == phi ) 417 break; 418 v->set_req(i, proj_path_data ); 419 } else if( v->is_ConstraintCast() ) { 420 v->set_req(0, proj_path_ctrl ); 421 v->set_req(1, proj_path_data ); 422 } else 423 ShouldNotReachHere(); 424 } 425 426 // Now replace the original iff's True/False with region_s/region_t. 427 // This makes the original iff go dead. 428 for (DUIterator_Last i3min, i3 = iff->last_outs(i3min); i3 >= i3min; --i3) { 429 Node* p = iff->last_out(i3); 430 assert( p->Opcode() == Op_IfTrue || p->Opcode() == Op_IfFalse, "" ); 431 Node *u = (p->Opcode() == Op_IfTrue) ? region_s : region_f; 432 // Replace p with u 433 igvn->add_users_to_worklist(p); 434 for (DUIterator_Last lmin, l = p->last_outs(lmin); l >= lmin;) { 435 Node* x = p->last_out(l); 436 igvn->hash_delete(x); 437 uint uses_found = 0; 438 for( uint j = 0; j < x->req(); j++ ) { 439 if( x->in(j) == p ) { 440 x->set_req(j, u); 441 uses_found++; 442 } 443 } 444 l -= uses_found; // we deleted 1 or more copies of this edge 445 } 446 igvn->remove_dead_node(p); 447 } 448 449 // Force the original merge dead 450 igvn->hash_delete(r); 451 // First, remove region's dead users. 452 for (DUIterator_Last lmin, l = r->last_outs(lmin); l >= lmin;) { 453 Node* u = r->last_out(l); 454 if( u == r ) { 455 r->set_req(0, nullptr); 456 } else { 457 assert(u->outcnt() == 0, "only dead users"); 458 igvn->remove_dead_node(u); 459 } 460 l -= 1; 461 } 462 igvn->remove_dead_node(r); 463 464 // Now remove the bogus extra edges used to keep things alive 465 igvn->remove_dead_node( hook ); 466 467 // Must return either the original node (now dead) or a new node 468 // (Do not return a top here, since that would break the uniqueness of top.) 469 return new ConINode(TypeInt::ZERO); 470 } 471 472 IfNode* IfNode::make_with_same_profile(IfNode* if_node_profile, Node* ctrl, Node* bol) { 473 // Assert here that we only try to create a clone from an If node with the same profiling if that actually makes sense. 474 // Some If node subtypes should not be cloned in this way. In theory, we should not clone BaseCountedLoopEndNodes. 475 // But they can end up being used as normal If nodes when peeling a loop - they serve as zero-trip guard. 476 // Allow them as well. 477 assert(if_node_profile->Opcode() == Op_If || if_node_profile->is_RangeCheck() 478 || if_node_profile->is_BaseCountedLoopEnd(), "should not clone other nodes"); 479 if (if_node_profile->is_RangeCheck()) { 480 // RangeCheck nodes could be further optimized. 481 return new RangeCheckNode(ctrl, bol, if_node_profile->_prob, if_node_profile->_fcnt); 482 } else { 483 // Not a RangeCheckNode? Fall back to IfNode. 484 return new IfNode(ctrl, bol, if_node_profile->_prob, if_node_profile->_fcnt); 485 } 486 } 487 488 // if this IfNode follows a range check pattern return the projection 489 // for the failed path 490 ProjNode* IfNode::range_check_trap_proj(int& flip_test, Node*& l, Node*& r) { 491 if (outcnt() != 2) { 492 return nullptr; 493 } 494 Node* b = in(1); 495 if (b == nullptr || !b->is_Bool()) return nullptr; 496 BoolNode* bn = b->as_Bool(); 497 Node* cmp = bn->in(1); 498 if (cmp == nullptr) return nullptr; 499 if (cmp->Opcode() != Op_CmpU) return nullptr; 500 501 l = cmp->in(1); 502 r = cmp->in(2); 503 flip_test = 1; 504 if (bn->_test._test == BoolTest::le) { 505 l = cmp->in(2); 506 r = cmp->in(1); 507 flip_test = 2; 508 } else if (bn->_test._test != BoolTest::lt) { 509 return nullptr; 510 } 511 if (l->is_top()) return nullptr; // Top input means dead test 512 if (r->Opcode() != Op_LoadRange && !is_RangeCheck()) return nullptr; 513 514 // We have recognized one of these forms: 515 // Flip 1: If (Bool[<] CmpU(l, LoadRange)) ... 516 // Flip 2: If (Bool[<=] CmpU(LoadRange, l)) ... 517 518 ProjNode* iftrap = proj_out_or_null(flip_test == 2 ? true : false); 519 return iftrap; 520 } 521 522 523 //------------------------------is_range_check--------------------------------- 524 // Return 0 if not a range check. Return 1 if a range check and set index and 525 // offset. Return 2 if we had to negate the test. Index is null if the check 526 // is versus a constant. 527 int RangeCheckNode::is_range_check(Node* &range, Node* &index, jint &offset) { 528 int flip_test = 0; 529 Node* l = nullptr; 530 Node* r = nullptr; 531 ProjNode* iftrap = range_check_trap_proj(flip_test, l, r); 532 533 if (iftrap == nullptr) { 534 return 0; 535 } 536 537 // Make sure it's a real range check by requiring an uncommon trap 538 // along the OOB path. Otherwise, it's possible that the user wrote 539 // something which optimized to look like a range check but behaves 540 // in some other way. 541 if (iftrap->is_uncommon_trap_proj(Deoptimization::Reason_range_check) == nullptr) { 542 return 0; 543 } 544 545 // Look for index+offset form 546 Node* ind = l; 547 jint off = 0; 548 if (l->is_top()) { 549 return 0; 550 } else if (l->Opcode() == Op_AddI) { 551 if ((off = l->in(1)->find_int_con(0)) != 0) { 552 ind = l->in(2)->uncast(); 553 } else if ((off = l->in(2)->find_int_con(0)) != 0) { 554 ind = l->in(1)->uncast(); 555 } 556 } else if ((off = l->find_int_con(-1)) >= 0) { 557 // constant offset with no variable index 558 ind = nullptr; 559 } else { 560 // variable index with no constant offset (or dead negative index) 561 off = 0; 562 } 563 564 // Return all the values: 565 index = ind; 566 offset = off; 567 range = r; 568 return flip_test; 569 } 570 571 //------------------------------adjust_check----------------------------------- 572 // Adjust (widen) a prior range check 573 static void adjust_check(IfProjNode* proj, Node* range, Node* index, 574 int flip, jint off_lo, PhaseIterGVN* igvn) { 575 PhaseGVN *gvn = igvn; 576 // Break apart the old check 577 Node *iff = proj->in(0); 578 Node *bol = iff->in(1); 579 if( bol->is_top() ) return; // In case a partially dead range check appears 580 // bail (or bomb[ASSERT/DEBUG]) if NOT projection-->IfNode-->BoolNode 581 DEBUG_ONLY( if (!bol->is_Bool()) { proj->dump(3); fatal("Expect projection-->IfNode-->BoolNode"); } ) 582 if (!bol->is_Bool()) return; 583 584 Node *cmp = bol->in(1); 585 // Compute a new check 586 Node *new_add = gvn->intcon(off_lo); 587 if (index) { 588 new_add = off_lo ? gvn->transform(new AddINode(index, new_add)) : index; 589 } 590 Node *new_cmp = (flip == 1) 591 ? new CmpUNode(new_add, range) 592 : new CmpUNode(range, new_add); 593 new_cmp = gvn->transform(new_cmp); 594 // See if no need to adjust the existing check 595 if (new_cmp == cmp) return; 596 // Else, adjust existing check 597 Node* new_bol = gvn->transform(new BoolNode(new_cmp, bol->as_Bool()->_test._test)); 598 igvn->rehash_node_delayed(iff); 599 iff->set_req_X(1, new_bol, igvn); 600 // As part of range check smearing, this range check is widened. Loads and range check Cast nodes that are control 601 // dependent on this range check now depend on multiple dominating range checks. These control dependent nodes end up 602 // at the lowest/nearest dominating check in the graph. To ensure that these Loads/Casts do not float above any of the 603 // dominating checks (even when the lowest dominating check is later replaced by yet another dominating check), we 604 // need to pin them at the lowest dominating check. 605 proj->pin_array_access_nodes(igvn); 606 } 607 608 //------------------------------up_one_dom------------------------------------- 609 // Walk up the dominator tree one step. Return null at root or true 610 // complex merges. Skips through small diamonds. 611 Node* IfNode::up_one_dom(Node *curr, bool linear_only) { 612 Node *dom = curr->in(0); 613 if( !dom ) // Found a Region degraded to a copy? 614 return curr->nonnull_req(); // Skip thru it 615 616 if( curr != dom ) // Normal walk up one step? 617 return dom; 618 619 // Use linear_only if we are still parsing, since we cannot 620 // trust the regions to be fully filled in. 621 if (linear_only) 622 return nullptr; 623 624 if( dom->is_Root() ) 625 return nullptr; 626 627 // Else hit a Region. Check for a loop header 628 if( dom->is_Loop() ) 629 return dom->in(1); // Skip up thru loops 630 631 // Check for small diamonds 632 Node *din1, *din2, *din3, *din4; 633 if( dom->req() == 3 && // 2-path merge point 634 (din1 = dom ->in(1)) && // Left path exists 635 (din2 = dom ->in(2)) && // Right path exists 636 (din3 = din1->in(0)) && // Left path up one 637 (din4 = din2->in(0)) ) { // Right path up one 638 if( din3->is_Call() && // Handle a slow-path call on either arm 639 (din3 = din3->in(0)) ) 640 din3 = din3->in(0); 641 if( din4->is_Call() && // Handle a slow-path call on either arm 642 (din4 = din4->in(0)) ) 643 din4 = din4->in(0); 644 if (din3 != nullptr && din3 == din4 && din3->is_If()) // Regions not degraded to a copy 645 return din3; // Skip around diamonds 646 } 647 648 // Give up the search at true merges 649 return nullptr; // Dead loop? Or hit root? 650 } 651 652 653 //------------------------------filtered_int_type-------------------------------- 654 // Return a possibly more restrictive type for val based on condition control flow for an if 655 const TypeInt* IfNode::filtered_int_type(PhaseGVN* gvn, Node* val, Node* if_proj) { 656 assert(if_proj && 657 (if_proj->Opcode() == Op_IfTrue || if_proj->Opcode() == Op_IfFalse), "expecting an if projection"); 658 if (if_proj->in(0) && if_proj->in(0)->is_If()) { 659 IfNode* iff = if_proj->in(0)->as_If(); 660 if (iff->in(1) && iff->in(1)->is_Bool()) { 661 BoolNode* bol = iff->in(1)->as_Bool(); 662 if (bol->in(1) && bol->in(1)->is_Cmp()) { 663 const CmpNode* cmp = bol->in(1)->as_Cmp(); 664 if (cmp->in(1) == val) { 665 const TypeInt* cmp2_t = gvn->type(cmp->in(2))->isa_int(); 666 if (cmp2_t != nullptr) { 667 jint lo = cmp2_t->_lo; 668 jint hi = cmp2_t->_hi; 669 BoolTest::mask msk = if_proj->Opcode() == Op_IfTrue ? bol->_test._test : bol->_test.negate(); 670 switch (msk) { 671 case BoolTest::ne: { 672 // If val is compared to its lower or upper bound, we can narrow the type 673 const TypeInt* val_t = gvn->type(val)->isa_int(); 674 if (val_t != nullptr && !val_t->singleton() && cmp2_t->is_con()) { 675 if (val_t->_lo == lo) { 676 return TypeInt::make(val_t->_lo + 1, val_t->_hi, val_t->_widen); 677 } else if (val_t->_hi == hi) { 678 return TypeInt::make(val_t->_lo, val_t->_hi - 1, val_t->_widen); 679 } 680 } 681 // Can't refine type 682 return nullptr; 683 } 684 case BoolTest::eq: 685 return cmp2_t; 686 case BoolTest::lt: 687 lo = TypeInt::INT->_lo; 688 if (hi != min_jint) { 689 hi = hi - 1; 690 } 691 break; 692 case BoolTest::le: 693 lo = TypeInt::INT->_lo; 694 break; 695 case BoolTest::gt: 696 if (lo != max_jint) { 697 lo = lo + 1; 698 } 699 hi = TypeInt::INT->_hi; 700 break; 701 case BoolTest::ge: 702 // lo unchanged 703 hi = TypeInt::INT->_hi; 704 break; 705 default: 706 break; 707 } 708 const TypeInt* rtn_t = TypeInt::make(lo, hi, cmp2_t->_widen); 709 return rtn_t; 710 } 711 } 712 } 713 } 714 } 715 return nullptr; 716 } 717 718 //------------------------------fold_compares---------------------------- 719 // See if a pair of CmpIs can be converted into a CmpU. In some cases 720 // the direction of this if is determined by the preceding if so it 721 // can be eliminate entirely. 722 // 723 // Given an if testing (CmpI n v) check for an immediately control 724 // dependent if that is testing (CmpI n v2) and has one projection 725 // leading to this if and the other projection leading to a region 726 // that merges one of this ifs control projections. 727 // 728 // If 729 // / | 730 // / | 731 // / | 732 // If | 733 // /\ | 734 // / \ | 735 // / \ | 736 // / Region 737 // 738 // Or given an if testing (CmpI n v) check for a dominating if that is 739 // testing (CmpI n v2), both having one projection leading to an 740 // uncommon trap. Allow Another independent guard in between to cover 741 // an explicit range check: 742 // if (index < 0 || index >= array.length) { 743 // which may need a null check to guard the LoadRange 744 // 745 // If 746 // / \ 747 // / \ 748 // / \ 749 // If unc 750 // /\ 751 // / \ 752 // / \ 753 // / unc 754 // 755 756 // Is the comparison for this If suitable for folding? 757 bool IfNode::cmpi_folds(PhaseIterGVN* igvn, bool fold_ne) { 758 return in(1) != nullptr && 759 in(1)->is_Bool() && 760 in(1)->in(1) != nullptr && 761 in(1)->in(1)->Opcode() == Op_CmpI && 762 in(1)->in(1)->in(2) != nullptr && 763 in(1)->in(1)->in(2) != igvn->C->top() && 764 (in(1)->as_Bool()->_test.is_less() || 765 in(1)->as_Bool()->_test.is_greater() || 766 (fold_ne && in(1)->as_Bool()->_test._test == BoolTest::ne)); 767 } 768 769 // Is a dominating control suitable for folding with this if? 770 bool IfNode::is_ctrl_folds(Node* ctrl, PhaseIterGVN* igvn) { 771 return ctrl != nullptr && 772 ctrl->is_Proj() && 773 ctrl->outcnt() == 1 && // No side-effects 774 ctrl->in(0) != nullptr && 775 ctrl->in(0)->Opcode() == Op_If && 776 ctrl->in(0)->outcnt() == 2 && 777 ctrl->in(0)->as_If()->cmpi_folds(igvn, true) && 778 // Must compare same value 779 ctrl->in(0)->in(1)->in(1)->in(1) != nullptr && 780 ctrl->in(0)->in(1)->in(1)->in(1) != igvn->C->top() && 781 ctrl->in(0)->in(1)->in(1)->in(1) == in(1)->in(1)->in(1); 782 } 783 784 // Do this If and the dominating If share a region? 785 bool IfNode::has_shared_region(ProjNode* proj, ProjNode*& success, ProjNode*& fail) { 786 ProjNode* otherproj = proj->other_if_proj(); 787 Node* otherproj_ctrl_use = otherproj->unique_ctrl_out_or_null(); 788 RegionNode* region = (otherproj_ctrl_use != nullptr && otherproj_ctrl_use->is_Region()) ? otherproj_ctrl_use->as_Region() : nullptr; 789 success = nullptr; 790 fail = nullptr; 791 792 if (otherproj->outcnt() == 1 && region != nullptr && !region->has_phi()) { 793 for (int i = 0; i < 2; i++) { 794 ProjNode* proj = proj_out(i); 795 if (success == nullptr && proj->outcnt() == 1 && proj->unique_out() == region) { 796 success = proj; 797 } else if (fail == nullptr) { 798 fail = proj; 799 } else { 800 success = fail = nullptr; 801 } 802 } 803 } 804 return success != nullptr && fail != nullptr; 805 } 806 807 bool IfNode::is_dominator_unc(CallStaticJavaNode* dom_unc, CallStaticJavaNode* unc) { 808 // Different methods and methods containing jsrs are not supported. 809 ciMethod* method = unc->jvms()->method(); 810 ciMethod* dom_method = dom_unc->jvms()->method(); 811 if (method != dom_method || method->has_jsrs()) { 812 return false; 813 } 814 // Check that both traps are in the same activation of the method (instead 815 // of two activations being inlined through different call sites) by verifying 816 // that the call stacks are equal for both JVMStates. 817 JVMState* dom_caller = dom_unc->jvms()->caller(); 818 JVMState* caller = unc->jvms()->caller(); 819 if ((dom_caller == nullptr) != (caller == nullptr)) { 820 // The current method must either be inlined into both dom_caller and 821 // caller or must not be inlined at all (top method). Bail out otherwise. 822 return false; 823 } else if (dom_caller != nullptr && !dom_caller->same_calls_as(caller)) { 824 return false; 825 } 826 // Check that the bci of the dominating uncommon trap dominates the bci 827 // of the dominated uncommon trap. Otherwise we may not re-execute 828 // the dominated check after deoptimization from the merged uncommon trap. 829 ciTypeFlow* flow = dom_method->get_flow_analysis(); 830 int bci = unc->jvms()->bci(); 831 int dom_bci = dom_unc->jvms()->bci(); 832 if (!flow->is_dominated_by(bci, dom_bci)) { 833 return false; 834 } 835 836 return true; 837 } 838 839 // Return projection that leads to an uncommon trap if any 840 ProjNode* IfNode::uncommon_trap_proj(CallStaticJavaNode*& call, Deoptimization::DeoptReason reason) const { 841 for (int i = 0; i < 2; i++) { 842 call = proj_out(i)->is_uncommon_trap_proj(reason); 843 if (call != nullptr) { 844 return proj_out(i); 845 } 846 } 847 return nullptr; 848 } 849 850 // Do this If and the dominating If both branch out to an uncommon trap 851 bool IfNode::has_only_uncommon_traps(ProjNode* proj, ProjNode*& success, ProjNode*& fail, PhaseIterGVN* igvn) { 852 ProjNode* otherproj = proj->other_if_proj(); 853 CallStaticJavaNode* dom_unc = otherproj->is_uncommon_trap_proj(); 854 855 if (otherproj->outcnt() == 1 && dom_unc != nullptr) { 856 // We need to re-execute the folded Ifs after deoptimization from the merged traps 857 if (!dom_unc->jvms()->should_reexecute()) { 858 return false; 859 } 860 861 CallStaticJavaNode* unc = nullptr; 862 ProjNode* unc_proj = uncommon_trap_proj(unc); 863 if (unc_proj != nullptr && unc_proj->outcnt() == 1) { 864 if (dom_unc == unc) { 865 // Allow the uncommon trap to be shared through a region 866 RegionNode* r = unc->in(0)->as_Region(); 867 if (r->outcnt() != 2 || r->req() != 3 || r->find_edge(otherproj) == -1 || r->find_edge(unc_proj) == -1) { 868 return false; 869 } 870 assert(r->has_phi() == nullptr, "simple region shouldn't have a phi"); 871 } else if (dom_unc->in(0) != otherproj || unc->in(0) != unc_proj) { 872 return false; 873 } 874 875 if (!is_dominator_unc(dom_unc, unc)) { 876 return false; 877 } 878 879 // See merge_uncommon_traps: the reason of the uncommon trap 880 // will be changed and the state of the dominating If will be 881 // used. Checked that we didn't apply this transformation in a 882 // previous compilation and it didn't cause too many traps 883 ciMethod* dom_method = dom_unc->jvms()->method(); 884 int dom_bci = dom_unc->jvms()->bci(); 885 if (!igvn->C->too_many_traps(dom_method, dom_bci, Deoptimization::Reason_unstable_fused_if) && 886 !igvn->C->too_many_traps(dom_method, dom_bci, Deoptimization::Reason_range_check) && 887 // Return true if c2 manages to reconcile with UnstableIf optimization. See the comments for it. 888 igvn->C->remove_unstable_if_trap(dom_unc, true/*yield*/)) { 889 success = unc_proj; 890 fail = unc_proj->other_if_proj(); 891 return true; 892 } 893 } 894 } 895 return false; 896 } 897 898 // Check that the 2 CmpI can be folded into as single CmpU and proceed with the folding 899 bool IfNode::fold_compares_helper(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn) { 900 Node* this_cmp = in(1)->in(1); 901 BoolNode* this_bool = in(1)->as_Bool(); 902 IfNode* dom_iff = proj->in(0)->as_If(); 903 BoolNode* dom_bool = dom_iff->in(1)->as_Bool(); 904 Node* lo = dom_iff->in(1)->in(1)->in(2); 905 Node* hi = this_cmp->in(2); 906 Node* n = this_cmp->in(1); 907 ProjNode* otherproj = proj->other_if_proj(); 908 909 const TypeInt* lo_type = IfNode::filtered_int_type(igvn, n, otherproj); 910 const TypeInt* hi_type = IfNode::filtered_int_type(igvn, n, success); 911 912 BoolTest::mask lo_test = dom_bool->_test._test; 913 BoolTest::mask hi_test = this_bool->_test._test; 914 BoolTest::mask cond = hi_test; 915 916 // convert: 917 // 918 // dom_bool = x {<,<=,>,>=} a 919 // / \ 920 // proj = {True,False} / \ otherproj = {False,True} 921 // / 922 // this_bool = x {<,<=} b 923 // / \ 924 // fail = {True,False} / \ success = {False,True} 925 // / 926 // 927 // (Second test guaranteed canonicalized, first one may not have 928 // been canonicalized yet) 929 // 930 // into: 931 // 932 // cond = (x - lo) {<u,<=u,>u,>=u} adjusted_lim 933 // / \ 934 // fail / \ success 935 // / 936 // 937 938 // Figure out which of the two tests sets the upper bound and which 939 // sets the lower bound if any. 940 Node* adjusted_lim = nullptr; 941 if (lo_type != nullptr && hi_type != nullptr && hi_type->_lo > lo_type->_hi && 942 hi_type->_hi == max_jint && lo_type->_lo == min_jint && lo_test != BoolTest::ne) { 943 assert((dom_bool->_test.is_less() && !proj->_con) || 944 (dom_bool->_test.is_greater() && proj->_con), "incorrect test"); 945 946 // this_bool = < 947 // dom_bool = >= (proj = True) or dom_bool = < (proj = False) 948 // x in [a, b[ on the fail (= True) projection, b > a-1 (because of hi_type->_lo > lo_type->_hi test above): 949 // lo = a, hi = b, adjusted_lim = b-a, cond = <u 950 // dom_bool = > (proj = True) or dom_bool = <= (proj = False) 951 // x in ]a, b[ on the fail (= True) projection, b > a: 952 // lo = a+1, hi = b, adjusted_lim = b-a-1, cond = <u 953 // this_bool = <= 954 // dom_bool = >= (proj = True) or dom_bool = < (proj = False) 955 // x in [a, b] on the fail (= True) projection, b+1 > a-1: 956 // lo = a, hi = b, adjusted_lim = b-a+1, cond = <u 957 // lo = a, hi = b, adjusted_lim = b-a, cond = <=u doesn't work because b = a - 1 is possible, then b-a = -1 958 // dom_bool = > (proj = True) or dom_bool = <= (proj = False) 959 // x in ]a, b] on the fail (= True) projection b+1 > a: 960 // lo = a+1, hi = b, adjusted_lim = b-a, cond = <u 961 // lo = a+1, hi = b, adjusted_lim = b-a-1, cond = <=u doesn't work because a = b is possible, then b-a-1 = -1 962 963 if (hi_test == BoolTest::lt) { 964 if (lo_test == BoolTest::gt || lo_test == BoolTest::le) { 965 lo = igvn->transform(new AddINode(lo, igvn->intcon(1))); 966 } 967 } else if (hi_test == BoolTest::le) { 968 if (lo_test == BoolTest::ge || lo_test == BoolTest::lt) { 969 adjusted_lim = igvn->transform(new SubINode(hi, lo)); 970 adjusted_lim = igvn->transform(new AddINode(adjusted_lim, igvn->intcon(1))); 971 cond = BoolTest::lt; 972 } else if (lo_test == BoolTest::gt || lo_test == BoolTest::le) { 973 adjusted_lim = igvn->transform(new SubINode(hi, lo)); 974 lo = igvn->transform(new AddINode(lo, igvn->intcon(1))); 975 cond = BoolTest::lt; 976 } else { 977 assert(false, "unhandled lo_test: %d", lo_test); 978 return false; 979 } 980 } else { 981 assert(igvn->_worklist.member(in(1)) && in(1)->Value(igvn) != igvn->type(in(1)), "unhandled hi_test: %d", hi_test); 982 return false; 983 } 984 // this test was canonicalized 985 assert(this_bool->_test.is_less() && fail->_con, "incorrect test"); 986 } else if (lo_type != nullptr && hi_type != nullptr && lo_type->_lo > hi_type->_hi && 987 lo_type->_hi == max_jint && hi_type->_lo == min_jint && lo_test != BoolTest::ne) { 988 989 // this_bool = < 990 // dom_bool = < (proj = True) or dom_bool = >= (proj = False) 991 // x in [b, a[ on the fail (= False) projection, a > b-1 (because of lo_type->_lo > hi_type->_hi above): 992 // lo = b, hi = a, adjusted_lim = a-b, cond = >=u 993 // dom_bool = <= (proj = True) or dom_bool = > (proj = False) 994 // x in [b, a] on the fail (= False) projection, a+1 > b-1: 995 // lo = b, hi = a, adjusted_lim = a-b+1, cond = >=u 996 // lo = b, hi = a, adjusted_lim = a-b, cond = >u doesn't work because a = b - 1 is possible, then b-a = -1 997 // this_bool = <= 998 // dom_bool = < (proj = True) or dom_bool = >= (proj = False) 999 // x in ]b, a[ on the fail (= False) projection, a > b: 1000 // lo = b+1, hi = a, adjusted_lim = a-b-1, cond = >=u 1001 // dom_bool = <= (proj = True) or dom_bool = > (proj = False) 1002 // x in ]b, a] on the fail (= False) projection, a+1 > b: 1003 // lo = b+1, hi = a, adjusted_lim = a-b, cond = >=u 1004 // lo = b+1, hi = a, adjusted_lim = a-b-1, cond = >u doesn't work because a = b is possible, then b-a-1 = -1 1005 1006 swap(lo, hi); 1007 swap(lo_type, hi_type); 1008 swap(lo_test, hi_test); 1009 1010 assert((dom_bool->_test.is_less() && proj->_con) || 1011 (dom_bool->_test.is_greater() && !proj->_con), "incorrect test"); 1012 1013 cond = (hi_test == BoolTest::le || hi_test == BoolTest::gt) ? BoolTest::gt : BoolTest::ge; 1014 1015 if (lo_test == BoolTest::lt) { 1016 if (hi_test == BoolTest::lt || hi_test == BoolTest::ge) { 1017 cond = BoolTest::ge; 1018 } else if (hi_test == BoolTest::le || hi_test == BoolTest::gt) { 1019 adjusted_lim = igvn->transform(new SubINode(hi, lo)); 1020 adjusted_lim = igvn->transform(new AddINode(adjusted_lim, igvn->intcon(1))); 1021 cond = BoolTest::ge; 1022 } else { 1023 assert(false, "unhandled hi_test: %d", hi_test); 1024 return false; 1025 } 1026 } else if (lo_test == BoolTest::le) { 1027 if (hi_test == BoolTest::lt || hi_test == BoolTest::ge) { 1028 lo = igvn->transform(new AddINode(lo, igvn->intcon(1))); 1029 cond = BoolTest::ge; 1030 } else if (hi_test == BoolTest::le || hi_test == BoolTest::gt) { 1031 adjusted_lim = igvn->transform(new SubINode(hi, lo)); 1032 lo = igvn->transform(new AddINode(lo, igvn->intcon(1))); 1033 cond = BoolTest::ge; 1034 } else { 1035 assert(false, "unhandled hi_test: %d", hi_test); 1036 return false; 1037 } 1038 } else { 1039 assert(igvn->_worklist.member(in(1)) && in(1)->Value(igvn) != igvn->type(in(1)), "unhandled lo_test: %d", lo_test); 1040 return false; 1041 } 1042 // this test was canonicalized 1043 assert(this_bool->_test.is_less() && !fail->_con, "incorrect test"); 1044 } else { 1045 const TypeInt* failtype = filtered_int_type(igvn, n, proj); 1046 if (failtype != nullptr) { 1047 const TypeInt* type2 = filtered_int_type(igvn, n, fail); 1048 if (type2 != nullptr) { 1049 if (failtype->filter(type2) == Type::TOP) { 1050 // previous if determines the result of this if so 1051 // replace Bool with constant 1052 igvn->replace_input_of(this, 1, igvn->intcon(success->_con)); 1053 return true; 1054 } 1055 } 1056 } 1057 return false; 1058 } 1059 1060 assert(lo != nullptr && hi != nullptr, "sanity"); 1061 Node* hook = new Node(lo); // Add a use to lo to prevent him from dying 1062 // Merge the two compares into a single unsigned compare by building (CmpU (n - lo) (hi - lo)) 1063 Node* adjusted_val = igvn->transform(new SubINode(n, lo)); 1064 if (adjusted_lim == nullptr) { 1065 adjusted_lim = igvn->transform(new SubINode(hi, lo)); 1066 } 1067 hook->destruct(igvn); 1068 1069 if (adjusted_val->is_top() || adjusted_lim->is_top()) { 1070 return false; 1071 } 1072 1073 if (igvn->type(adjusted_lim)->is_int()->_lo < 0 && 1074 !igvn->C->post_loop_opts_phase()) { 1075 // If range check elimination applies to this comparison, it includes code to protect from overflows that may 1076 // cause the main loop to be skipped entirely. Delay this transformation. 1077 // Example: 1078 // for (int i = 0; i < limit; i++) { 1079 // if (i < max_jint && i > min_jint) {... 1080 // } 1081 // Comparisons folded as: 1082 // i - min_jint - 1 <u -2 1083 // when RC applies, main loop limit becomes: 1084 // min(limit, max(-2 + min_jint + 1, min_jint)) 1085 // = min(limit, min_jint) 1086 // = min_jint 1087 if (adjusted_val->outcnt() == 0) { 1088 igvn->remove_dead_node(adjusted_val); 1089 } 1090 if (adjusted_lim->outcnt() == 0) { 1091 igvn->remove_dead_node(adjusted_lim); 1092 } 1093 igvn->C->record_for_post_loop_opts_igvn(this); 1094 return false; 1095 } 1096 1097 Node* newcmp = igvn->transform(new CmpUNode(adjusted_val, adjusted_lim)); 1098 Node* newbool = igvn->transform(new BoolNode(newcmp, cond)); 1099 1100 igvn->replace_input_of(dom_iff, 1, igvn->intcon(proj->_con)); 1101 igvn->replace_input_of(this, 1, newbool); 1102 1103 return true; 1104 } 1105 1106 // Merge the branches that trap for this If and the dominating If into 1107 // a single region that branches to the uncommon trap for the 1108 // dominating If 1109 Node* IfNode::merge_uncommon_traps(ProjNode* proj, ProjNode* success, ProjNode* fail, PhaseIterGVN* igvn) { 1110 Node* res = this; 1111 assert(success->in(0) == this, "bad projection"); 1112 1113 ProjNode* otherproj = proj->other_if_proj(); 1114 1115 CallStaticJavaNode* unc = success->is_uncommon_trap_proj(); 1116 CallStaticJavaNode* dom_unc = otherproj->is_uncommon_trap_proj(); 1117 1118 if (unc != dom_unc) { 1119 Node* r = new RegionNode(3); 1120 1121 r->set_req(1, otherproj); 1122 r->set_req(2, success); 1123 r = igvn->transform(r); 1124 assert(r->is_Region(), "can't go away"); 1125 1126 // Make both If trap at the state of the first If: once the CmpI 1127 // nodes are merged, if we trap we don't know which of the CmpI 1128 // nodes would have caused the trap so we have to restart 1129 // execution at the first one 1130 igvn->replace_input_of(dom_unc, 0, r); 1131 igvn->replace_input_of(unc, 0, igvn->C->top()); 1132 } 1133 int trap_request = dom_unc->uncommon_trap_request(); 1134 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request); 1135 Deoptimization::DeoptAction action = Deoptimization::trap_request_action(trap_request); 1136 1137 int flip_test = 0; 1138 Node* l = nullptr; 1139 Node* r = nullptr; 1140 1141 if (success->in(0)->as_If()->range_check_trap_proj(flip_test, l, r) != nullptr) { 1142 // If this looks like a range check, change the trap to 1143 // Reason_range_check so the compiler recognizes it as a range 1144 // check and applies the corresponding optimizations 1145 trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_range_check, action); 1146 1147 improve_address_types(l, r, fail, igvn); 1148 1149 res = igvn->transform(new RangeCheckNode(in(0), in(1), _prob, _fcnt)); 1150 } else if (unc != dom_unc) { 1151 // If we trap we won't know what CmpI would have caused the trap 1152 // so use a special trap reason to mark this pair of CmpI nodes as 1153 // bad candidate for folding. On recompilation we won't fold them 1154 // and we may trap again but this time we'll know what branch 1155 // traps 1156 trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_unstable_fused_if, action); 1157 } 1158 igvn->replace_input_of(dom_unc, TypeFunc::Parms, igvn->intcon(trap_request)); 1159 return res; 1160 } 1161 1162 // If we are turning 2 CmpI nodes into a CmpU that follows the pattern 1163 // of a rangecheck on index i, on 64 bit the compares may be followed 1164 // by memory accesses using i as index. In that case, the CmpU tells 1165 // us something about the values taken by i that can help the compiler 1166 // (see Compile::conv_I2X_index()) 1167 void IfNode::improve_address_types(Node* l, Node* r, ProjNode* fail, PhaseIterGVN* igvn) { 1168 #ifdef _LP64 1169 ResourceMark rm; 1170 Node_Stack stack(2); 1171 1172 assert(r->Opcode() == Op_LoadRange, "unexpected range check"); 1173 const TypeInt* array_size = igvn->type(r)->is_int(); 1174 1175 stack.push(l, 0); 1176 1177 while(stack.size() > 0) { 1178 Node* n = stack.node(); 1179 uint start = stack.index(); 1180 1181 uint i = start; 1182 for (; i < n->outcnt(); i++) { 1183 Node* use = n->raw_out(i); 1184 if (stack.size() == 1) { 1185 if (use->Opcode() == Op_ConvI2L) { 1186 const TypeLong* bounds = use->as_Type()->type()->is_long(); 1187 if (bounds->_lo <= array_size->_lo && bounds->_hi >= array_size->_hi && 1188 (bounds->_lo != array_size->_lo || bounds->_hi != array_size->_hi)) { 1189 stack.set_index(i+1); 1190 stack.push(use, 0); 1191 break; 1192 } 1193 } 1194 } else if (use->is_Mem()) { 1195 Node* ctrl = use->in(0); 1196 for (int i = 0; i < 10 && ctrl != nullptr && ctrl != fail; i++) { 1197 ctrl = up_one_dom(ctrl); 1198 } 1199 if (ctrl == fail) { 1200 Node* init_n = stack.node_at(1); 1201 assert(init_n->Opcode() == Op_ConvI2L, "unexpected first node"); 1202 // Create a new narrow ConvI2L node that is dependent on the range check 1203 Node* new_n = igvn->C->conv_I2X_index(igvn, l, array_size, fail); 1204 1205 // The type of the ConvI2L may be widen and so the new 1206 // ConvI2L may not be better than an existing ConvI2L 1207 if (new_n != init_n) { 1208 for (uint j = 2; j < stack.size(); j++) { 1209 Node* n = stack.node_at(j); 1210 Node* clone = n->clone(); 1211 int rep = clone->replace_edge(init_n, new_n, igvn); 1212 assert(rep > 0, "can't find expected node?"); 1213 clone = igvn->transform(clone); 1214 init_n = n; 1215 new_n = clone; 1216 } 1217 igvn->hash_delete(use); 1218 int rep = use->replace_edge(init_n, new_n, igvn); 1219 assert(rep > 0, "can't find expected node?"); 1220 igvn->transform(use); 1221 if (init_n->outcnt() == 0) { 1222 igvn->_worklist.push(init_n); 1223 } 1224 } 1225 } 1226 } else if (use->in(0) == nullptr && (igvn->type(use)->isa_long() || 1227 igvn->type(use)->isa_ptr())) { 1228 stack.set_index(i+1); 1229 stack.push(use, 0); 1230 break; 1231 } 1232 } 1233 if (i == n->outcnt()) { 1234 stack.pop(); 1235 } 1236 } 1237 #endif 1238 } 1239 1240 bool IfNode::is_cmp_with_loadrange(ProjNode* proj) { 1241 if (in(1) != nullptr && 1242 in(1)->in(1) != nullptr && 1243 in(1)->in(1)->in(2) != nullptr) { 1244 Node* other = in(1)->in(1)->in(2); 1245 if (other->Opcode() == Op_LoadRange && 1246 ((other->in(0) != nullptr && other->in(0) == proj) || 1247 (other->in(0) == nullptr && 1248 other->in(2) != nullptr && 1249 other->in(2)->is_AddP() && 1250 other->in(2)->in(1) != nullptr && 1251 other->in(2)->in(1)->Opcode() == Op_CastPP && 1252 other->in(2)->in(1)->in(0) == proj))) { 1253 return true; 1254 } 1255 } 1256 return false; 1257 } 1258 1259 bool IfNode::is_null_check(ProjNode* proj, PhaseIterGVN* igvn) { 1260 Node* other = in(1)->in(1)->in(2); 1261 if (other->in(MemNode::Address) != nullptr && 1262 proj->in(0)->in(1) != nullptr && 1263 proj->in(0)->in(1)->is_Bool() && 1264 proj->in(0)->in(1)->in(1) != nullptr && 1265 proj->in(0)->in(1)->in(1)->Opcode() == Op_CmpP && 1266 proj->in(0)->in(1)->in(1)->in(2) != nullptr && 1267 proj->in(0)->in(1)->in(1)->in(1) == other->in(MemNode::Address)->in(AddPNode::Address)->uncast() && 1268 igvn->type(proj->in(0)->in(1)->in(1)->in(2)) == TypePtr::NULL_PTR) { 1269 return true; 1270 } 1271 return false; 1272 } 1273 1274 // Check that the If that is in between the 2 integer comparisons has 1275 // no side effect 1276 bool IfNode::is_side_effect_free_test(ProjNode* proj, PhaseIterGVN* igvn) { 1277 if (proj == nullptr) { 1278 return false; 1279 } 1280 CallStaticJavaNode* unc = proj->is_uncommon_trap_if_pattern(); 1281 if (unc != nullptr && proj->outcnt() <= 2) { 1282 if (proj->outcnt() == 1 || 1283 // Allow simple null check from LoadRange 1284 (is_cmp_with_loadrange(proj) && is_null_check(proj, igvn))) { 1285 CallStaticJavaNode* unc = proj->is_uncommon_trap_if_pattern(); 1286 CallStaticJavaNode* dom_unc = proj->in(0)->in(0)->as_Proj()->is_uncommon_trap_if_pattern(); 1287 assert(dom_unc != nullptr, "is_uncommon_trap_if_pattern returned null"); 1288 1289 // reroute_side_effect_free_unc changes the state of this 1290 // uncommon trap to restart execution at the previous 1291 // CmpI. Check that this change in a previous compilation didn't 1292 // cause too many traps. 1293 int trap_request = unc->uncommon_trap_request(); 1294 Deoptimization::DeoptReason reason = Deoptimization::trap_request_reason(trap_request); 1295 1296 if (igvn->C->too_many_traps(dom_unc->jvms()->method(), dom_unc->jvms()->bci(), reason)) { 1297 return false; 1298 } 1299 1300 if (!is_dominator_unc(dom_unc, unc)) { 1301 return false; 1302 } 1303 1304 return true; 1305 } 1306 } 1307 return false; 1308 } 1309 1310 // Make the If between the 2 integer comparisons trap at the state of 1311 // the first If: the last CmpI is the one replaced by a CmpU and the 1312 // first CmpI is eliminated, so the test between the 2 CmpI nodes 1313 // won't be guarded by the first CmpI anymore. It can trap in cases 1314 // where the first CmpI would have prevented it from executing: on a 1315 // trap, we need to restart execution at the state of the first CmpI 1316 void IfNode::reroute_side_effect_free_unc(ProjNode* proj, ProjNode* dom_proj, PhaseIterGVN* igvn) { 1317 CallStaticJavaNode* dom_unc = dom_proj->is_uncommon_trap_if_pattern(); 1318 ProjNode* otherproj = proj->other_if_proj(); 1319 CallStaticJavaNode* unc = proj->is_uncommon_trap_if_pattern(); 1320 Node* call_proj = dom_unc->unique_ctrl_out(); 1321 Node* halt = call_proj->unique_ctrl_out(); 1322 1323 Node* new_unc = dom_unc->clone(); 1324 call_proj = call_proj->clone(); 1325 halt = halt->clone(); 1326 Node* c = otherproj->clone(); 1327 1328 c = igvn->transform(c); 1329 new_unc->set_req(TypeFunc::Parms, unc->in(TypeFunc::Parms)); 1330 new_unc->set_req(0, c); 1331 new_unc = igvn->transform(new_unc); 1332 call_proj->set_req(0, new_unc); 1333 call_proj = igvn->transform(call_proj); 1334 halt->set_req(0, call_proj); 1335 halt = igvn->transform(halt); 1336 1337 igvn->replace_node(otherproj, igvn->C->top()); 1338 igvn->C->root()->add_req(halt); 1339 } 1340 1341 Node* IfNode::fold_compares(PhaseIterGVN* igvn) { 1342 if (Opcode() != Op_If) return nullptr; 1343 1344 if (cmpi_folds(igvn)) { 1345 Node* ctrl = in(0); 1346 if (is_ctrl_folds(ctrl, igvn)) { 1347 // A integer comparison immediately dominated by another integer 1348 // comparison 1349 ProjNode* success = nullptr; 1350 ProjNode* fail = nullptr; 1351 ProjNode* dom_cmp = ctrl->as_Proj(); 1352 if (has_shared_region(dom_cmp, success, fail) && 1353 // Next call modifies graph so must be last 1354 fold_compares_helper(dom_cmp, success, fail, igvn)) { 1355 return this; 1356 } 1357 if (has_only_uncommon_traps(dom_cmp, success, fail, igvn) && 1358 // Next call modifies graph so must be last 1359 fold_compares_helper(dom_cmp, success, fail, igvn)) { 1360 return merge_uncommon_traps(dom_cmp, success, fail, igvn); 1361 } 1362 return nullptr; 1363 } else if (ctrl->in(0) != nullptr && 1364 ctrl->in(0)->in(0) != nullptr) { 1365 ProjNode* success = nullptr; 1366 ProjNode* fail = nullptr; 1367 Node* dom = ctrl->in(0)->in(0); 1368 ProjNode* dom_cmp = dom->isa_Proj(); 1369 ProjNode* other_cmp = ctrl->isa_Proj(); 1370 1371 // Check if it's an integer comparison dominated by another 1372 // integer comparison with another test in between 1373 if (is_ctrl_folds(dom, igvn) && 1374 has_only_uncommon_traps(dom_cmp, success, fail, igvn) && 1375 is_side_effect_free_test(other_cmp, igvn) && 1376 // Next call modifies graph so must be last 1377 fold_compares_helper(dom_cmp, success, fail, igvn)) { 1378 reroute_side_effect_free_unc(other_cmp, dom_cmp, igvn); 1379 return merge_uncommon_traps(dom_cmp, success, fail, igvn); 1380 } 1381 } 1382 } 1383 return nullptr; 1384 } 1385 1386 //------------------------------remove_useless_bool---------------------------- 1387 // Check for people making a useless boolean: things like 1388 // if( (x < y ? true : false) ) { ... } 1389 // Replace with if( x < y ) { ... } 1390 static Node *remove_useless_bool(IfNode *iff, PhaseGVN *phase) { 1391 Node *i1 = iff->in(1); 1392 if( !i1->is_Bool() ) return nullptr; 1393 BoolNode *bol = i1->as_Bool(); 1394 1395 Node *cmp = bol->in(1); 1396 if( cmp->Opcode() != Op_CmpI ) return nullptr; 1397 1398 // Must be comparing against a bool 1399 const Type *cmp2_t = phase->type( cmp->in(2) ); 1400 if( cmp2_t != TypeInt::ZERO && 1401 cmp2_t != TypeInt::ONE ) 1402 return nullptr; 1403 1404 // Find a prior merge point merging the boolean 1405 i1 = cmp->in(1); 1406 if( !i1->is_Phi() ) return nullptr; 1407 PhiNode *phi = i1->as_Phi(); 1408 if( phase->type( phi ) != TypeInt::BOOL ) 1409 return nullptr; 1410 1411 // Check for diamond pattern 1412 int true_path = phi->is_diamond_phi(); 1413 if( true_path == 0 ) return nullptr; 1414 1415 // Make sure that iff and the control of the phi are different. This 1416 // should really only happen for dead control flow since it requires 1417 // an illegal cycle. 1418 if (phi->in(0)->in(1)->in(0) == iff) return nullptr; 1419 1420 // phi->region->if_proj->ifnode->bool->cmp 1421 BoolNode *bol2 = phi->in(0)->in(1)->in(0)->in(1)->as_Bool(); 1422 1423 // Now get the 'sense' of the test correct so we can plug in 1424 // either iff2->in(1) or its complement. 1425 int flip = 0; 1426 if( bol->_test._test == BoolTest::ne ) flip = 1-flip; 1427 else if( bol->_test._test != BoolTest::eq ) return nullptr; 1428 if( cmp2_t == TypeInt::ZERO ) flip = 1-flip; 1429 1430 const Type *phi1_t = phase->type( phi->in(1) ); 1431 const Type *phi2_t = phase->type( phi->in(2) ); 1432 // Check for Phi(0,1) and flip 1433 if( phi1_t == TypeInt::ZERO ) { 1434 if( phi2_t != TypeInt::ONE ) return nullptr; 1435 flip = 1-flip; 1436 } else { 1437 // Check for Phi(1,0) 1438 if( phi1_t != TypeInt::ONE ) return nullptr; 1439 if( phi2_t != TypeInt::ZERO ) return nullptr; 1440 } 1441 if( true_path == 2 ) { 1442 flip = 1-flip; 1443 } 1444 1445 Node* new_bol = (flip ? phase->transform( bol2->negate(phase) ) : bol2); 1446 assert(new_bol != iff->in(1), "must make progress"); 1447 iff->set_req_X(1, new_bol, phase); 1448 // Intervening diamond probably goes dead 1449 phase->C->set_major_progress(); 1450 return iff; 1451 } 1452 1453 static IfNode* idealize_test(PhaseGVN* phase, IfNode* iff); 1454 1455 struct RangeCheck { 1456 IfProjNode* ctl; 1457 jint off; 1458 }; 1459 1460 Node* IfNode::Ideal_common(PhaseGVN *phase, bool can_reshape) { 1461 if (remove_dead_region(phase, can_reshape)) return this; 1462 // No Def-Use info? 1463 if (!can_reshape) return nullptr; 1464 1465 // Don't bother trying to transform a dead if 1466 if (in(0)->is_top()) return nullptr; 1467 // Don't bother trying to transform an if with a dead test 1468 if (in(1)->is_top()) return nullptr; 1469 // Another variation of a dead test 1470 if (in(1)->is_Con()) return nullptr; 1471 // Another variation of a dead if 1472 if (outcnt() < 2) return nullptr; 1473 1474 // Canonicalize the test. 1475 Node* idt_if = idealize_test(phase, this); 1476 if (idt_if != nullptr) return idt_if; 1477 1478 // Try to split the IF 1479 PhaseIterGVN *igvn = phase->is_IterGVN(); 1480 Node *s = split_if(this, igvn); 1481 if (s != nullptr) return s; 1482 1483 return NodeSentinel; 1484 } 1485 1486 //------------------------------Ideal------------------------------------------ 1487 // Return a node which is more "ideal" than the current node. Strip out 1488 // control copies 1489 Node* IfNode::Ideal(PhaseGVN *phase, bool can_reshape) { 1490 Node* res = Ideal_common(phase, can_reshape); 1491 if (res != NodeSentinel) { 1492 return res; 1493 } 1494 1495 // Check for people making a useless boolean: things like 1496 // if( (x < y ? true : false) ) { ... } 1497 // Replace with if( x < y ) { ... } 1498 Node* bol2 = remove_useless_bool(this, phase); 1499 if (bol2) return bol2; 1500 1501 if (in(0) == nullptr) return nullptr; // Dead loop? 1502 1503 PhaseIterGVN* igvn = phase->is_IterGVN(); 1504 Node* result = fold_compares(igvn); 1505 if (result != nullptr) { 1506 return result; 1507 } 1508 1509 // Scan for an equivalent test 1510 int dist = 4; // Cutoff limit for search 1511 if (is_If() && in(1)->is_Bool()) { 1512 Node* cmp = in(1)->in(1); 1513 if (cmp->Opcode() == Op_CmpP && 1514 cmp->in(2) != nullptr && // make sure cmp is not already dead 1515 cmp->in(2)->bottom_type() == TypePtr::NULL_PTR) { 1516 dist = 64; // Limit for null-pointer scans 1517 } 1518 } 1519 1520 Node* prev_dom = search_identical(dist, igvn); 1521 1522 if (prev_dom != nullptr) { 1523 // Dominating CountedLoopEnd (left over from some now dead loop) will become the new loop exit. Outer strip mined 1524 // loop will go away. Mark this loop as no longer strip mined. 1525 if (is_CountedLoopEnd()) { 1526 CountedLoopNode* counted_loop_node = as_CountedLoopEnd()->loopnode(); 1527 if (counted_loop_node != nullptr) { 1528 counted_loop_node->clear_strip_mined(); 1529 } 1530 } 1531 // Replace dominated IfNode 1532 return dominated_by(prev_dom, igvn, false); 1533 } 1534 1535 return simple_subsuming(igvn); 1536 } 1537 1538 //------------------------------dominated_by----------------------------------- 1539 Node* IfNode::dominated_by(Node* prev_dom, PhaseIterGVN* igvn, bool pin_array_access_nodes) { 1540 #ifndef PRODUCT 1541 if (TraceIterativeGVN) { 1542 tty->print(" Removing IfNode: "); this->dump(); 1543 } 1544 #endif 1545 1546 igvn->hash_delete(this); // Remove self to prevent spurious V-N 1547 Node *idom = in(0); 1548 // Need opcode to decide which way 'this' test goes 1549 int prev_op = prev_dom->Opcode(); 1550 Node *top = igvn->C->top(); // Shortcut to top 1551 1552 // Now walk the current IfNode's projections. 1553 // Loop ends when 'this' has no more uses. 1554 for (DUIterator_Last imin, i = last_outs(imin); i >= imin; --i) { 1555 Node *ifp = last_out(i); // Get IfTrue/IfFalse 1556 igvn->add_users_to_worklist(ifp); 1557 // Check which projection it is and set target. 1558 // Data-target is either the dominating projection of the same type 1559 // or TOP if the dominating projection is of opposite type. 1560 // Data-target will be used as the new control edge for the non-CFG 1561 // nodes like Casts and Loads. 1562 Node *data_target = (ifp->Opcode() == prev_op) ? prev_dom : top; 1563 // Control-target is just the If's immediate dominator or TOP. 1564 Node *ctrl_target = (ifp->Opcode() == prev_op) ? idom : top; 1565 1566 // For each child of an IfTrue/IfFalse projection, reroute. 1567 // Loop ends when projection has no more uses. 1568 for (DUIterator_Last jmin, j = ifp->last_outs(jmin); j >= jmin; --j) { 1569 Node* s = ifp->last_out(j); // Get child of IfTrue/IfFalse 1570 if (s->depends_only_on_test() && igvn->no_dependent_zero_check(s)) { 1571 // For control producers. 1572 // Do not rewire Div and Mod nodes which could have a zero divisor to avoid skipping their zero check. 1573 igvn->replace_input_of(s, 0, data_target); // Move child to data-target 1574 if (pin_array_access_nodes && data_target != top) { 1575 // As a result of range check smearing, Loads and range check Cast nodes that are control dependent on this 1576 // range check (that is about to be removed) now depend on multiple dominating range checks. After the removal 1577 // of this range check, these control dependent nodes end up at the lowest/nearest dominating check in the 1578 // graph. To ensure that these Loads/Casts do not float above any of the dominating checks (even when the 1579 // lowest dominating check is later replaced by yet another dominating check), we need to pin them at the 1580 // lowest dominating check. 1581 Node* clone = s->pin_array_access_node(); 1582 if (clone != nullptr) { 1583 clone = igvn->transform(clone); 1584 igvn->replace_node(s, clone); 1585 } 1586 } 1587 } else { 1588 // Find the control input matching this def-use edge. 1589 // For Regions it may not be in slot 0. 1590 uint l; 1591 for (l = 0; s->in(l) != ifp; l++) { } 1592 igvn->replace_input_of(s, l, ctrl_target); 1593 } 1594 } // End for each child of a projection 1595 1596 igvn->remove_dead_node(ifp); 1597 } // End for each IfTrue/IfFalse child of If 1598 1599 // Kill the IfNode 1600 igvn->remove_dead_node(this); 1601 1602 // Must return either the original node (now dead) or a new node 1603 // (Do not return a top here, since that would break the uniqueness of top.) 1604 return new ConINode(TypeInt::ZERO); 1605 } 1606 1607 Node* IfNode::search_identical(int dist, PhaseIterGVN* igvn) { 1608 // Setup to scan up the CFG looking for a dominating test 1609 Node* dom = in(0); 1610 Node* prev_dom = this; 1611 int op = Opcode(); 1612 // Search up the dominator tree for an If with an identical test 1613 while (dom->Opcode() != op || // Not same opcode? 1614 !same_condition(dom, igvn) || // Not same input 1? 1615 prev_dom->in(0) != dom) { // One path of test does not dominate? 1616 if (dist < 0) return nullptr; 1617 1618 dist--; 1619 prev_dom = dom; 1620 dom = up_one_dom(dom); 1621 if (!dom) return nullptr; 1622 } 1623 1624 // Check that we did not follow a loop back to ourselves 1625 if (this == dom) { 1626 return nullptr; 1627 } 1628 1629 #ifndef PRODUCT 1630 if (dist > 2) { // Add to count of null checks elided 1631 explicit_null_checks_elided++; 1632 } 1633 #endif 1634 1635 return prev_dom; 1636 } 1637 1638 bool IfNode::same_condition(const Node* dom, PhaseIterGVN* igvn) const { 1639 Node* dom_bool = dom->in(1); 1640 Node* this_bool = in(1); 1641 if (dom_bool == this_bool) { 1642 return true; 1643 } 1644 1645 if (dom_bool == nullptr || !dom_bool->is_Bool() || 1646 this_bool == nullptr || !this_bool->is_Bool()) { 1647 return false; 1648 } 1649 Node* dom_cmp = dom_bool->in(1); 1650 Node* this_cmp = this_bool->in(1); 1651 1652 // If the comparison is a subtype check, then SubTypeCheck nodes may have profile data attached to them and may be 1653 // different nodes even-though they perform the same subtype check 1654 if (dom_cmp == nullptr || !dom_cmp->is_SubTypeCheck() || 1655 this_cmp == nullptr || !this_cmp->is_SubTypeCheck()) { 1656 return false; 1657 } 1658 1659 if (dom_cmp->in(1) != this_cmp->in(1) || 1660 dom_cmp->in(2) != this_cmp->in(2) || 1661 dom_bool->as_Bool()->_test._test != this_bool->as_Bool()->_test._test) { 1662 return false; 1663 } 1664 1665 return true; 1666 } 1667 1668 1669 static int subsuming_bool_test_encode(Node*); 1670 1671 // Check if dominating test is subsuming 'this' one. 1672 // 1673 // cmp 1674 // / \ 1675 // (r1) bool \ 1676 // / bool (r2) 1677 // (dom) if \ 1678 // \ ) 1679 // (pre) if[TF] / 1680 // \ / 1681 // if (this) 1682 // \r1 1683 // r2\ eqT eqF neT neF ltT ltF leT leF gtT gtF geT geF 1684 // eq t f f t f - - f f - - f 1685 // ne f t t f t - - t t - - t 1686 // lt f - - f t f - f f - f t 1687 // le t - - t t - t f f t - t 1688 // gt f - - f f - f t t f - f 1689 // ge t - - t f t - t t - t f 1690 // 1691 Node* IfNode::simple_subsuming(PhaseIterGVN* igvn) { 1692 // Table encoding: N/A (na), True-branch (tb), False-branch (fb). 1693 static enum { na, tb, fb } s_short_circuit_map[6][12] = { 1694 /*rel: eq+T eq+F ne+T ne+F lt+T lt+F le+T le+F gt+T gt+F ge+T ge+F*/ 1695 /*eq*/{ tb, fb, fb, tb, fb, na, na, fb, fb, na, na, fb }, 1696 /*ne*/{ fb, tb, tb, fb, tb, na, na, tb, tb, na, na, tb }, 1697 /*lt*/{ fb, na, na, fb, tb, fb, na, fb, fb, na, fb, tb }, 1698 /*le*/{ tb, na, na, tb, tb, na, tb, fb, fb, tb, na, tb }, 1699 /*gt*/{ fb, na, na, fb, fb, na, fb, tb, tb, fb, na, fb }, 1700 /*ge*/{ tb, na, na, tb, fb, tb, na, tb, tb, na, tb, fb }}; 1701 1702 Node* pre = in(0); 1703 if (!pre->is_IfTrue() && !pre->is_IfFalse()) { 1704 return nullptr; 1705 } 1706 Node* dom = pre->in(0); 1707 if (!dom->is_If()) { 1708 return nullptr; 1709 } 1710 Node* bol = in(1); 1711 if (!bol->is_Bool()) { 1712 return nullptr; 1713 } 1714 Node* cmp = in(1)->in(1); 1715 if (!cmp->is_Cmp()) { 1716 return nullptr; 1717 } 1718 1719 if (!dom->in(1)->is_Bool()) { 1720 return nullptr; 1721 } 1722 if (dom->in(1)->in(1) != cmp) { // Not same cond? 1723 return nullptr; 1724 } 1725 1726 int drel = subsuming_bool_test_encode(dom->in(1)); 1727 int trel = subsuming_bool_test_encode(bol); 1728 int bout = pre->is_IfFalse() ? 1 : 0; 1729 1730 if (drel < 0 || trel < 0) { 1731 return nullptr; 1732 } 1733 int br = s_short_circuit_map[trel][2*drel+bout]; 1734 if (br == na) { 1735 return nullptr; 1736 } 1737 #ifndef PRODUCT 1738 if (TraceIterativeGVN) { 1739 tty->print(" Subsumed IfNode: "); dump(); 1740 } 1741 #endif 1742 // Replace condition with constant True(1)/False(0). 1743 bool is_always_true = br == tb; 1744 set_req(1, igvn->intcon(is_always_true ? 1 : 0)); 1745 1746 // Update any data dependencies to the directly dominating test. This subsumed test is not immediately removed by igvn 1747 // and therefore subsequent optimizations might miss these data dependencies otherwise. There might be a dead loop 1748 // ('always_taken_proj' == 'pre') that is cleaned up later. Skip this case to make the iterator work properly. 1749 Node* always_taken_proj = proj_out(is_always_true); 1750 if (always_taken_proj != pre) { 1751 for (DUIterator_Fast imax, i = always_taken_proj->fast_outs(imax); i < imax; i++) { 1752 Node* u = always_taken_proj->fast_out(i); 1753 if (!u->is_CFG()) { 1754 igvn->replace_input_of(u, 0, pre); 1755 --i; 1756 --imax; 1757 } 1758 } 1759 } 1760 1761 if (bol->outcnt() == 0) { 1762 igvn->remove_dead_node(bol); // Kill the BoolNode. 1763 } 1764 return this; 1765 } 1766 1767 // Map BoolTest to local table encoding. The BoolTest (e)numerals 1768 // { eq = 0, ne = 4, le = 5, ge = 7, lt = 3, gt = 1 } 1769 // are mapped to table indices, while the remaining (e)numerals in BoolTest 1770 // { overflow = 2, no_overflow = 6, never = 8, illegal = 9 } 1771 // are ignored (these are not modeled in the table). 1772 // 1773 static int subsuming_bool_test_encode(Node* node) { 1774 precond(node->is_Bool()); 1775 BoolTest::mask x = node->as_Bool()->_test._test; 1776 switch (x) { 1777 case BoolTest::eq: return 0; 1778 case BoolTest::ne: return 1; 1779 case BoolTest::lt: return 2; 1780 case BoolTest::le: return 3; 1781 case BoolTest::gt: return 4; 1782 case BoolTest::ge: return 5; 1783 case BoolTest::overflow: 1784 case BoolTest::no_overflow: 1785 case BoolTest::never: 1786 case BoolTest::illegal: 1787 default: 1788 return -1; 1789 } 1790 } 1791 1792 //------------------------------Identity--------------------------------------- 1793 // If the test is constant & we match, then we are the input Control 1794 Node* IfProjNode::Identity(PhaseGVN* phase) { 1795 // Can only optimize if cannot go the other way 1796 const TypeTuple *t = phase->type(in(0))->is_tuple(); 1797 if (t == TypeTuple::IFNEITHER || (always_taken(t) && 1798 // During parsing (GVN) we don't remove dead code aggressively. 1799 // Cut off dead branch and let PhaseRemoveUseless take care of it. 1800 (!phase->is_IterGVN() || 1801 // During IGVN, first wait for the dead branch to be killed. 1802 // Otherwise, the IfNode's control will have two control uses (the IfNode 1803 // that doesn't go away because it still has uses and this branch of the 1804 // If) which breaks other optimizations. Node::has_special_unique_user() 1805 // will cause this node to be reprocessed once the dead branch is killed. 1806 in(0)->outcnt() == 1))) { 1807 // IfNode control 1808 if (in(0)->is_BaseCountedLoopEnd()) { 1809 // CountedLoopEndNode may be eliminated by if subsuming, replace CountedLoopNode with LoopNode to 1810 // avoid mismatching between CountedLoopNode and CountedLoopEndNode in the following optimization. 1811 Node* head = unique_ctrl_out_or_null(); 1812 if (head != nullptr && head->is_BaseCountedLoop() && head->in(LoopNode::LoopBackControl) == this) { 1813 Node* new_head = new LoopNode(head->in(LoopNode::EntryControl), this); 1814 phase->is_IterGVN()->register_new_node_with_optimizer(new_head); 1815 phase->is_IterGVN()->replace_node(head, new_head); 1816 } 1817 } 1818 return in(0)->in(0); 1819 } 1820 // no progress 1821 return this; 1822 } 1823 1824 bool IfNode::is_zero_trip_guard() const { 1825 if (in(1)->is_Bool() && in(1)->in(1)->is_Cmp()) { 1826 return in(1)->in(1)->in(1)->Opcode() == Op_OpaqueZeroTripGuard; 1827 } 1828 return false; 1829 } 1830 1831 void IfProjNode::pin_array_access_nodes(PhaseIterGVN* igvn) { 1832 for (DUIterator i = outs(); has_out(i); i++) { 1833 Node* u = out(i); 1834 if (!u->depends_only_on_test()) { 1835 continue; 1836 } 1837 Node* clone = u->pin_array_access_node(); 1838 if (clone != nullptr) { 1839 clone = igvn->transform(clone); 1840 assert(clone != u, "shouldn't common"); 1841 igvn->replace_node(u, clone); 1842 --i; 1843 } 1844 } 1845 } 1846 1847 #ifndef PRODUCT 1848 void IfNode::dump_spec(outputStream* st) const { 1849 switch (_assertion_predicate_type) { 1850 case AssertionPredicateType::InitValue: 1851 st->print("#Init Value Assertion Predicate "); 1852 break; 1853 case AssertionPredicateType::LastValue: 1854 st->print("#Last Value Assertion Predicate "); 1855 break; 1856 case AssertionPredicateType::FinalIv: 1857 st->print("#Final IV Assertion Predicate "); 1858 break; 1859 case AssertionPredicateType::None: 1860 // No Assertion Predicate 1861 break; 1862 default: 1863 fatal("Unknown Assertion Predicate type"); 1864 } 1865 st->print("P=%f, C=%f", _prob, _fcnt); 1866 } 1867 #endif // NOT PRODUCT 1868 1869 //------------------------------idealize_test---------------------------------- 1870 // Try to canonicalize tests better. Peek at the Cmp/Bool/If sequence and 1871 // come up with a canonical sequence. Bools getting 'eq', 'gt' and 'ge' forms 1872 // converted to 'ne', 'le' and 'lt' forms. IfTrue/IfFalse get swapped as 1873 // needed. 1874 static IfNode* idealize_test(PhaseGVN* phase, IfNode* iff) { 1875 assert(iff->in(0) != nullptr, "If must be live"); 1876 1877 if (iff->outcnt() != 2) return nullptr; // Malformed projections. 1878 Node* old_if_f = iff->proj_out(false); 1879 Node* old_if_t = iff->proj_out(true); 1880 1881 // CountedLoopEnds want the back-control test to be TRUE, regardless of 1882 // whether they are testing a 'gt' or 'lt' condition. The 'gt' condition 1883 // happens in count-down loops 1884 if (iff->is_BaseCountedLoopEnd()) return nullptr; 1885 if (!iff->in(1)->is_Bool()) return nullptr; // Happens for partially optimized IF tests 1886 BoolNode *b = iff->in(1)->as_Bool(); 1887 BoolTest bt = b->_test; 1888 // Test already in good order? 1889 if( bt.is_canonical() ) 1890 return nullptr; 1891 1892 // Flip test to be canonical. Requires flipping the IfFalse/IfTrue and 1893 // cloning the IfNode. 1894 Node* new_b = phase->transform( new BoolNode(b->in(1), bt.negate()) ); 1895 if( !new_b->is_Bool() ) return nullptr; 1896 b = new_b->as_Bool(); 1897 1898 PhaseIterGVN *igvn = phase->is_IterGVN(); 1899 assert( igvn, "Test is not canonical in parser?" ); 1900 1901 // The IF node never really changes, but it needs to be cloned 1902 iff = iff->clone()->as_If(); 1903 iff->set_req(1, b); 1904 iff->_prob = 1.0-iff->_prob; 1905 1906 Node *prior = igvn->hash_find_insert(iff); 1907 if( prior ) { 1908 igvn->remove_dead_node(iff); 1909 iff = (IfNode*)prior; 1910 } else { 1911 // Cannot call transform on it just yet 1912 igvn->set_type_bottom(iff); 1913 } 1914 igvn->_worklist.push(iff); 1915 1916 // Now handle projections. Cloning not required. 1917 Node* new_if_f = (Node*)(new IfFalseNode( iff )); 1918 Node* new_if_t = (Node*)(new IfTrueNode ( iff )); 1919 1920 igvn->register_new_node_with_optimizer(new_if_f); 1921 igvn->register_new_node_with_optimizer(new_if_t); 1922 // Flip test, so flip trailing control 1923 igvn->replace_node(old_if_f, new_if_t); 1924 igvn->replace_node(old_if_t, new_if_f); 1925 1926 // Progress 1927 return iff; 1928 } 1929 1930 Node* RangeCheckNode::Ideal(PhaseGVN *phase, bool can_reshape) { 1931 Node* res = Ideal_common(phase, can_reshape); 1932 if (res != NodeSentinel) { 1933 return res; 1934 } 1935 1936 PhaseIterGVN *igvn = phase->is_IterGVN(); 1937 // Setup to scan up the CFG looking for a dominating test 1938 Node* prev_dom = this; 1939 1940 // Check for range-check vs other kinds of tests 1941 Node* index1; 1942 Node* range1; 1943 jint offset1; 1944 int flip1 = is_range_check(range1, index1, offset1); 1945 if (flip1) { 1946 Node* dom = in(0); 1947 // Try to remove extra range checks. All 'up_one_dom' gives up at merges 1948 // so all checks we inspect post-dominate the top-most check we find. 1949 // If we are going to fail the current check and we reach the top check 1950 // then we are guaranteed to fail, so just start interpreting there. 1951 // We 'expand' the top 3 range checks to include all post-dominating 1952 // checks. 1953 // 1954 // Example: 1955 // a[i+x] // (1) 1 < x < 6 1956 // a[i+3] // (2) 1957 // a[i+4] // (3) 1958 // a[i+6] // max = max of all constants 1959 // a[i+2] 1960 // a[i+1] // min = min of all constants 1961 // 1962 // If x < 3: 1963 // (1) a[i+x]: Leave unchanged 1964 // (2) a[i+3]: Replace with a[i+max] = a[i+6]: i+x < i+3 <= i+6 -> (2) is covered 1965 // (3) a[i+4]: Replace with a[i+min] = a[i+1]: i+1 < i+4 <= i+6 -> (3) and all following checks are covered 1966 // Remove all other a[i+c] checks 1967 // 1968 // If x >= 3: 1969 // (1) a[i+x]: Leave unchanged 1970 // (2) a[i+3]: Replace with a[i+min] = a[i+1]: i+1 < i+3 <= i+x -> (2) is covered 1971 // (3) a[i+4]: Replace with a[i+max] = a[i+6]: i+1 < i+4 <= i+6 -> (3) and all following checks are covered 1972 // Remove all other a[i+c] checks 1973 // 1974 // We only need the top 2 range checks if x is the min or max of all constants. 1975 // 1976 // This, however, only works if the interval [i+min,i+max] is not larger than max_int (i.e. abs(max - min) < max_int): 1977 // The theoretical max size of an array is max_int with: 1978 // - Valid index space: [0,max_int-1] 1979 // - Invalid index space: [max_int,-1] // max_int, min_int, min_int - 1 ..., -1 1980 // 1981 // The size of the consecutive valid index space is smaller than the size of the consecutive invalid index space. 1982 // If we choose min and max in such a way that: 1983 // - abs(max - min) < max_int 1984 // - i+max and i+min are inside the valid index space 1985 // then all indices [i+min,i+max] must be in the valid index space. Otherwise, the invalid index space must be 1986 // smaller than the valid index space which is never the case for any array size. 1987 // 1988 // Choosing a smaller array size only makes the valid index space smaller and the invalid index space larger and 1989 // the argument above still holds. 1990 // 1991 // Note that the same optimization with the same maximal accepted interval size can also be found in C1. 1992 const jlong maximum_number_of_min_max_interval_indices = (jlong)max_jint; 1993 1994 // The top 3 range checks seen 1995 const int NRC = 3; 1996 RangeCheck prev_checks[NRC]; 1997 int nb_checks = 0; 1998 1999 // Low and high offsets seen so far 2000 jint off_lo = offset1; 2001 jint off_hi = offset1; 2002 2003 bool found_immediate_dominator = false; 2004 2005 // Scan for the top checks and collect range of offsets 2006 for (int dist = 0; dist < 999; dist++) { // Range-Check scan limit 2007 if (dom->Opcode() == Op_RangeCheck && // Not same opcode? 2008 prev_dom->in(0) == dom) { // One path of test does dominate? 2009 if (dom == this) return nullptr; // dead loop 2010 // See if this is a range check 2011 Node* index2; 2012 Node* range2; 2013 jint offset2; 2014 int flip2 = dom->as_RangeCheck()->is_range_check(range2, index2, offset2); 2015 // See if this is a _matching_ range check, checking against 2016 // the same array bounds. 2017 if (flip2 == flip1 && range2 == range1 && index2 == index1 && 2018 dom->outcnt() == 2) { 2019 if (nb_checks == 0 && dom->in(1) == in(1)) { 2020 // Found an immediately dominating test at the same offset. 2021 // This kind of back-to-back test can be eliminated locally, 2022 // and there is no need to search further for dominating tests. 2023 assert(offset2 == offset1, "Same test but different offsets"); 2024 found_immediate_dominator = true; 2025 break; 2026 } 2027 2028 // "x - y" -> must add one to the difference for number of elements in [x,y] 2029 const jlong diff = (jlong)MIN2(offset2, off_lo) - (jlong)MAX2(offset2, off_hi); 2030 if (ABS(diff) < maximum_number_of_min_max_interval_indices) { 2031 // Gather expanded bounds 2032 off_lo = MIN2(off_lo, offset2); 2033 off_hi = MAX2(off_hi, offset2); 2034 // Record top NRC range checks 2035 prev_checks[nb_checks % NRC].ctl = prev_dom->as_IfProj(); 2036 prev_checks[nb_checks % NRC].off = offset2; 2037 nb_checks++; 2038 } 2039 } 2040 } 2041 prev_dom = dom; 2042 dom = up_one_dom(dom); 2043 if (!dom) break; 2044 } 2045 2046 if (!found_immediate_dominator) { 2047 // Attempt to widen the dominating range check to cover some later 2048 // ones. Since range checks "fail" by uncommon-trapping to the 2049 // interpreter, widening a check can make us speculatively enter 2050 // the interpreter. If we see range-check deopt's, do not widen! 2051 if (!phase->C->allow_range_check_smearing()) return nullptr; 2052 2053 if (can_reshape && !phase->C->post_loop_opts_phase()) { 2054 // We are about to perform range check smearing (i.e. remove this RangeCheck if it is dominated by 2055 // a series of RangeChecks which have a range that covers this RangeCheck). This can cause array access nodes to 2056 // be pinned. We want to avoid that and first allow range check elimination a chance to remove the RangeChecks 2057 // from loops. Hence, we delay range check smearing until after loop opts. 2058 phase->C->record_for_post_loop_opts_igvn(this); 2059 return nullptr; 2060 } 2061 2062 // Didn't find prior covering check, so cannot remove anything. 2063 if (nb_checks == 0) { 2064 return nullptr; 2065 } 2066 // Constant indices only need to check the upper bound. 2067 // Non-constant indices must check both low and high. 2068 int chk0 = (nb_checks - 1) % NRC; 2069 if (index1) { 2070 if (nb_checks == 1) { 2071 return nullptr; 2072 } else { 2073 // If the top range check's constant is the min or max of 2074 // all constants we widen the next one to cover the whole 2075 // range of constants. 2076 RangeCheck rc0 = prev_checks[chk0]; 2077 int chk1 = (nb_checks - 2) % NRC; 2078 RangeCheck rc1 = prev_checks[chk1]; 2079 if (rc0.off == off_lo) { 2080 adjust_check(rc1.ctl, range1, index1, flip1, off_hi, igvn); 2081 prev_dom = rc1.ctl; 2082 } else if (rc0.off == off_hi) { 2083 adjust_check(rc1.ctl, range1, index1, flip1, off_lo, igvn); 2084 prev_dom = rc1.ctl; 2085 } else { 2086 // If the top test's constant is not the min or max of all 2087 // constants, we need 3 range checks. We must leave the 2088 // top test unchanged because widening it would allow the 2089 // accesses it protects to successfully read/write out of 2090 // bounds. 2091 if (nb_checks == 2) { 2092 return nullptr; 2093 } 2094 int chk2 = (nb_checks - 3) % NRC; 2095 RangeCheck rc2 = prev_checks[chk2]; 2096 // The top range check a+i covers interval: -a <= i < length-a 2097 // The second range check b+i covers interval: -b <= i < length-b 2098 if (rc1.off <= rc0.off) { 2099 // if b <= a, we change the second range check to: 2100 // -min_of_all_constants <= i < length-min_of_all_constants 2101 // Together top and second range checks now cover: 2102 // -min_of_all_constants <= i < length-a 2103 // which is more restrictive than -b <= i < length-b: 2104 // -b <= -min_of_all_constants <= i < length-a <= length-b 2105 // The third check is then changed to: 2106 // -max_of_all_constants <= i < length-max_of_all_constants 2107 // so 2nd and 3rd checks restrict allowed values of i to: 2108 // -min_of_all_constants <= i < length-max_of_all_constants 2109 adjust_check(rc1.ctl, range1, index1, flip1, off_lo, igvn); 2110 adjust_check(rc2.ctl, range1, index1, flip1, off_hi, igvn); 2111 } else { 2112 // if b > a, we change the second range check to: 2113 // -max_of_all_constants <= i < length-max_of_all_constants 2114 // Together top and second range checks now cover: 2115 // -a <= i < length-max_of_all_constants 2116 // which is more restrictive than -b <= i < length-b: 2117 // -b < -a <= i < length-max_of_all_constants <= length-b 2118 // The third check is then changed to: 2119 // -max_of_all_constants <= i < length-max_of_all_constants 2120 // so 2nd and 3rd checks restrict allowed values of i to: 2121 // -min_of_all_constants <= i < length-max_of_all_constants 2122 adjust_check(rc1.ctl, range1, index1, flip1, off_hi, igvn); 2123 adjust_check(rc2.ctl, range1, index1, flip1, off_lo, igvn); 2124 } 2125 prev_dom = rc2.ctl; 2126 } 2127 } 2128 } else { 2129 RangeCheck rc0 = prev_checks[chk0]; 2130 // 'Widen' the offset of the 1st and only covering check 2131 adjust_check(rc0.ctl, range1, index1, flip1, off_hi, igvn); 2132 // Test is now covered by prior checks, dominate it out 2133 prev_dom = rc0.ctl; 2134 } 2135 // The last RangeCheck is found to be redundant with a sequence of n (n >= 2) preceding RangeChecks. 2136 // If an array load is control dependent on the eliminated range check, the array load nodes (CastII and Load) 2137 // become control dependent on the last range check of the sequence, but they are really dependent on the entire 2138 // sequence of RangeChecks. If RangeCheck#n is later replaced by a dominating identical check, the array load 2139 // nodes must not float above the n-1 other RangeCheck in the sequence. We pin the array load nodes here to 2140 // guarantee it doesn't happen. 2141 // 2142 // RangeCheck#1 RangeCheck#1 2143 // | \ | \ 2144 // | uncommon trap | uncommon trap 2145 // .. .. 2146 // RangeCheck#n -> RangeCheck#n 2147 // | \ | \ 2148 // | uncommon trap CastII uncommon trap 2149 // RangeCheck Load 2150 // | \ 2151 // CastII uncommon trap 2152 // Load 2153 2154 return dominated_by(prev_dom, igvn, true); 2155 } 2156 } else { 2157 prev_dom = search_identical(4, igvn); 2158 2159 if (prev_dom == nullptr) { 2160 return nullptr; 2161 } 2162 } 2163 2164 // Replace dominated IfNode 2165 return dominated_by(prev_dom, igvn, false); 2166 } 2167 2168 ParsePredicateNode::ParsePredicateNode(Node* control, Deoptimization::DeoptReason deopt_reason, PhaseGVN* gvn) 2169 : IfNode(control, gvn->intcon(1), PROB_MAX, COUNT_UNKNOWN), 2170 _deopt_reason(deopt_reason), 2171 _predicate_state(PredicateState::Useful) { 2172 init_class_id(Class_ParsePredicate); 2173 gvn->C->add_parse_predicate(this); 2174 gvn->C->record_for_post_loop_opts_igvn(this); 2175 #ifdef ASSERT 2176 switch (deopt_reason) { 2177 case Deoptimization::Reason_predicate: 2178 case Deoptimization::Reason_profile_predicate: 2179 case Deoptimization::Reason_auto_vectorization_check: 2180 case Deoptimization::Reason_loop_limit_check: 2181 break; 2182 default: 2183 assert(false, "unsupported deoptimization reason for Parse Predicate"); 2184 } 2185 #endif // ASSERT 2186 } 2187 2188 void ParsePredicateNode::mark_useless(PhaseIterGVN& igvn) { 2189 _predicate_state = PredicateState::Useless; 2190 igvn._worklist.push(this); 2191 } 2192 2193 Node* ParsePredicateNode::uncommon_trap() const { 2194 ParsePredicateUncommonProj* uncommon_proj = proj_out(0)->as_IfFalse(); 2195 Node* uct_region_or_call = uncommon_proj->unique_ctrl_out(); 2196 assert(uct_region_or_call->is_Region() || uct_region_or_call->is_Call(), "must be a region or call uct"); 2197 return uct_region_or_call; 2198 } 2199 2200 // Fold this node away once it becomes useless or at latest in post loop opts IGVN. 2201 const Type* ParsePredicateNode::Value(PhaseGVN* phase) const { 2202 assert(_predicate_state != PredicateState::MaybeUseful, "should only be MaybeUseful when eliminating useless " 2203 "predicates during loop opts"); 2204 if (phase->type(in(0)) == Type::TOP) { 2205 return Type::TOP; 2206 } 2207 if (_predicate_state == PredicateState::Useless || phase->C->post_loop_opts_phase()) { 2208 return TypeTuple::IFTRUE; 2209 } 2210 return bottom_type(); 2211 } 2212 2213 #ifndef PRODUCT 2214 void ParsePredicateNode::dump_spec(outputStream* st) const { 2215 st->print(" #"); 2216 switch (_deopt_reason) { 2217 case Deoptimization::DeoptReason::Reason_predicate: 2218 st->print("Loop "); 2219 break; 2220 case Deoptimization::DeoptReason::Reason_profile_predicate: 2221 st->print("Profiled_Loop "); 2222 break; 2223 case Deoptimization::DeoptReason::Reason_auto_vectorization_check: 2224 st->print("Auto_Vectorization_Check "); 2225 break; 2226 case Deoptimization::DeoptReason::Reason_loop_limit_check: 2227 st->print("Loop_Limit_Check "); 2228 break; 2229 default: 2230 fatal("unknown kind"); 2231 } 2232 if (_predicate_state == PredicateState::Useless) { 2233 st->print("#useless "); 2234 } 2235 } 2236 #endif // NOT PRODUCT