1 /* 2 * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "compiler/compileLog.hpp" 27 #include "gc/shared/collectedHeap.inline.hpp" 28 #include "gc/shared/tlab_globals.hpp" 29 #include "libadt/vectset.hpp" 30 #include "memory/universe.hpp" 31 #include "opto/addnode.hpp" 32 #include "opto/arraycopynode.hpp" 33 #include "opto/callnode.hpp" 34 #include "opto/castnode.hpp" 35 #include "opto/cfgnode.hpp" 36 #include "opto/compile.hpp" 37 #include "opto/convertnode.hpp" 38 #include "opto/graphKit.hpp" 39 #include "opto/intrinsicnode.hpp" 40 #include "opto/locknode.hpp" 41 #include "opto/loopnode.hpp" 42 #include "opto/macro.hpp" 43 #include "opto/memnode.hpp" 44 #include "opto/narrowptrnode.hpp" 45 #include "opto/node.hpp" 46 #include "opto/opaquenode.hpp" 47 #include "opto/phaseX.hpp" 48 #include "opto/rootnode.hpp" 49 #include "opto/runtime.hpp" 50 #include "opto/subnode.hpp" 51 #include "opto/subtypenode.hpp" 52 #include "opto/type.hpp" 53 #include "prims/jvmtiExport.hpp" 54 #include "runtime/continuation.hpp" 55 #include "runtime/sharedRuntime.hpp" 56 #include "utilities/macros.hpp" 57 #include "utilities/powerOfTwo.hpp" 58 #if INCLUDE_G1GC 59 #include "gc/g1/g1ThreadLocalData.hpp" 60 #endif // INCLUDE_G1GC 61 62 63 // 64 // Replace any references to "oldref" in inputs to "use" with "newref". 65 // Returns the number of replacements made. 66 // 67 int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) { 68 int nreplacements = 0; 69 uint req = use->req(); 70 for (uint j = 0; j < use->len(); j++) { 71 Node *uin = use->in(j); 72 if (uin == oldref) { 73 if (j < req) 74 use->set_req(j, newref); 75 else 76 use->set_prec(j, newref); 77 nreplacements++; 78 } else if (j >= req && uin == nullptr) { 79 break; 80 } 81 } 82 return nreplacements; 83 } 84 85 void PhaseMacroExpand::migrate_outs(Node *old, Node *target) { 86 assert(old != nullptr, "sanity"); 87 for (DUIterator_Fast imax, i = old->fast_outs(imax); i < imax; i++) { 88 Node* use = old->fast_out(i); 89 _igvn.rehash_node_delayed(use); 90 imax -= replace_input(use, old, target); 91 // back up iterator 92 --i; 93 } 94 assert(old->outcnt() == 0, "all uses must be deleted"); 95 } 96 97 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) { 98 Node* cmp; 99 if (mask != 0) { 100 Node* and_node = transform_later(new AndXNode(word, MakeConX(mask))); 101 cmp = transform_later(new CmpXNode(and_node, MakeConX(bits))); 102 } else { 103 cmp = word; 104 } 105 Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne)); 106 IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN ); 107 transform_later(iff); 108 109 // Fast path taken. 110 Node *fast_taken = transform_later(new IfFalseNode(iff)); 111 112 // Fast path not-taken, i.e. slow path 113 Node *slow_taken = transform_later(new IfTrueNode(iff)); 114 115 if (return_fast_path) { 116 region->init_req(edge, slow_taken); // Capture slow-control 117 return fast_taken; 118 } else { 119 region->init_req(edge, fast_taken); // Capture fast-control 120 return slow_taken; 121 } 122 } 123 124 //--------------------copy_predefined_input_for_runtime_call-------------------- 125 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) { 126 // Set fixed predefined input arguments 127 call->init_req( TypeFunc::Control, ctrl ); 128 call->init_req( TypeFunc::I_O , oldcall->in( TypeFunc::I_O) ); 129 call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ????? 130 call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) ); 131 call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) ); 132 } 133 134 //------------------------------make_slow_call--------------------------------- 135 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type, 136 address slow_call, const char* leaf_name, Node* slow_path, 137 Node* parm0, Node* parm1, Node* parm2) { 138 139 // Slow-path call 140 CallNode *call = leaf_name 141 ? (CallNode*)new CallLeafNode ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM ) 142 : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), TypeRawPtr::BOTTOM ); 143 144 // Slow path call has no side-effects, uses few values 145 copy_predefined_input_for_runtime_call(slow_path, oldcall, call ); 146 if (parm0 != nullptr) call->init_req(TypeFunc::Parms+0, parm0); 147 if (parm1 != nullptr) call->init_req(TypeFunc::Parms+1, parm1); 148 if (parm2 != nullptr) call->init_req(TypeFunc::Parms+2, parm2); 149 call->copy_call_debug_info(&_igvn, oldcall); 150 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON. 151 _igvn.replace_node(oldcall, call); 152 transform_later(call); 153 154 return call; 155 } 156 157 void PhaseMacroExpand::eliminate_gc_barrier(Node* p2x) { 158 BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2(); 159 bs->eliminate_gc_barrier(this, p2x); 160 #ifndef PRODUCT 161 if (PrintOptoStatistics) { 162 Atomic::inc(&PhaseMacroExpand::_GC_barriers_removed_counter); 163 } 164 #endif 165 } 166 167 // Search for a memory operation for the specified memory slice. 168 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) { 169 Node *orig_mem = mem; 170 Node *alloc_mem = alloc->as_Allocate()->proj_out_or_null(TypeFunc::Memory, /*io_use:*/false); 171 assert(alloc_mem != nullptr, "Allocation without a memory projection."); 172 const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr(); 173 while (true) { 174 if (mem == alloc_mem || mem == start_mem ) { 175 return mem; // hit one of our sentinels 176 } else if (mem->is_MergeMem()) { 177 mem = mem->as_MergeMem()->memory_at(alias_idx); 178 } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) { 179 Node *in = mem->in(0); 180 // we can safely skip over safepoints, calls, locks and membars because we 181 // already know that the object is safe to eliminate. 182 if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) { 183 return in; 184 } else if (in->is_Call()) { 185 CallNode *call = in->as_Call(); 186 if (call->may_modify(tinst, phase)) { 187 assert(call->is_ArrayCopy(), "ArrayCopy is the only call node that doesn't make allocation escape"); 188 if (call->as_ArrayCopy()->modifies(offset, offset, phase, false)) { 189 return in; 190 } 191 } 192 mem = in->in(TypeFunc::Memory); 193 } else if (in->is_MemBar()) { 194 ArrayCopyNode* ac = nullptr; 195 if (ArrayCopyNode::may_modify(tinst, in->as_MemBar(), phase, ac)) { 196 if (ac != nullptr) { 197 assert(ac->is_clonebasic(), "Only basic clone is a non escaping clone"); 198 return ac; 199 } 200 } 201 mem = in->in(TypeFunc::Memory); 202 } else { 203 #ifdef ASSERT 204 in->dump(); 205 mem->dump(); 206 assert(false, "unexpected projection"); 207 #endif 208 } 209 } else if (mem->is_Store()) { 210 const TypePtr* atype = mem->as_Store()->adr_type(); 211 int adr_idx = phase->C->get_alias_index(atype); 212 if (adr_idx == alias_idx) { 213 assert(atype->isa_oopptr(), "address type must be oopptr"); 214 int adr_offset = atype->offset(); 215 uint adr_iid = atype->is_oopptr()->instance_id(); 216 // Array elements references have the same alias_idx 217 // but different offset and different instance_id. 218 if (adr_offset == offset && adr_iid == alloc->_idx) { 219 return mem; 220 } 221 } else { 222 assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw"); 223 } 224 mem = mem->in(MemNode::Memory); 225 } else if (mem->is_ClearArray()) { 226 if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) { 227 // Can not bypass initialization of the instance 228 // we are looking. 229 debug_only(intptr_t offset;) 230 assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity"); 231 InitializeNode* init = alloc->as_Allocate()->initialization(); 232 // We are looking for stored value, return Initialize node 233 // or memory edge from Allocate node. 234 if (init != nullptr) { 235 return init; 236 } else { 237 return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers). 238 } 239 } 240 // Otherwise skip it (the call updated 'mem' value). 241 } else if (mem->Opcode() == Op_SCMemProj) { 242 mem = mem->in(0); 243 Node* adr = nullptr; 244 if (mem->is_LoadStore()) { 245 adr = mem->in(MemNode::Address); 246 } else { 247 assert(mem->Opcode() == Op_EncodeISOArray || 248 mem->Opcode() == Op_StrCompressedCopy, "sanity"); 249 adr = mem->in(3); // Destination array 250 } 251 const TypePtr* atype = adr->bottom_type()->is_ptr(); 252 int adr_idx = phase->C->get_alias_index(atype); 253 if (adr_idx == alias_idx) { 254 DEBUG_ONLY(mem->dump();) 255 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field"); 256 return nullptr; 257 } 258 mem = mem->in(MemNode::Memory); 259 } else if (mem->Opcode() == Op_StrInflatedCopy) { 260 Node* adr = mem->in(3); // Destination array 261 const TypePtr* atype = adr->bottom_type()->is_ptr(); 262 int adr_idx = phase->C->get_alias_index(atype); 263 if (adr_idx == alias_idx) { 264 DEBUG_ONLY(mem->dump();) 265 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field"); 266 return nullptr; 267 } 268 mem = mem->in(MemNode::Memory); 269 } else { 270 return mem; 271 } 272 assert(mem != orig_mem, "dead memory loop"); 273 } 274 } 275 276 // Generate loads from source of the arraycopy for fields of 277 // destination needed at a deoptimization point 278 Node* PhaseMacroExpand::make_arraycopy_load(ArrayCopyNode* ac, intptr_t offset, Node* ctl, Node* mem, BasicType ft, const Type *ftype, AllocateNode *alloc) { 279 BasicType bt = ft; 280 const Type *type = ftype; 281 if (ft == T_NARROWOOP) { 282 bt = T_OBJECT; 283 type = ftype->make_oopptr(); 284 } 285 Node* res = nullptr; 286 if (ac->is_clonebasic()) { 287 assert(ac->in(ArrayCopyNode::Src) != ac->in(ArrayCopyNode::Dest), "clone source equals destination"); 288 Node* base = ac->in(ArrayCopyNode::Src); 289 Node* adr = _igvn.transform(new AddPNode(base, base, _igvn.MakeConX(offset))); 290 const TypePtr* adr_type = _igvn.type(base)->is_ptr()->add_offset(offset); 291 MergeMemNode* mergemen = _igvn.transform(MergeMemNode::make(mem))->as_MergeMem(); 292 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); 293 res = ArrayCopyNode::load(bs, &_igvn, ctl, mergemen, adr, adr_type, type, bt); 294 } else { 295 if (ac->modifies(offset, offset, &_igvn, true)) { 296 assert(ac->in(ArrayCopyNode::Dest) == alloc->result_cast(), "arraycopy destination should be allocation's result"); 297 uint shift = exact_log2(type2aelembytes(bt)); 298 Node* src_pos = ac->in(ArrayCopyNode::SrcPos); 299 Node* dest_pos = ac->in(ArrayCopyNode::DestPos); 300 const TypeInt* src_pos_t = _igvn.type(src_pos)->is_int(); 301 const TypeInt* dest_pos_t = _igvn.type(dest_pos)->is_int(); 302 303 Node* adr = nullptr; 304 const TypePtr* adr_type = nullptr; 305 if (src_pos_t->is_con() && dest_pos_t->is_con()) { 306 intptr_t off = ((src_pos_t->get_con() - dest_pos_t->get_con()) << shift) + offset; 307 Node* base = ac->in(ArrayCopyNode::Src); 308 adr = _igvn.transform(new AddPNode(base, base, _igvn.MakeConX(off))); 309 adr_type = _igvn.type(base)->is_ptr()->add_offset(off); 310 if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) { 311 // Don't emit a new load from src if src == dst but try to get the value from memory instead 312 return value_from_mem(ac->in(TypeFunc::Memory), ctl, ft, ftype, adr_type->isa_oopptr(), alloc); 313 } 314 } else { 315 Node* diff = _igvn.transform(new SubINode(ac->in(ArrayCopyNode::SrcPos), ac->in(ArrayCopyNode::DestPos))); 316 #ifdef _LP64 317 diff = _igvn.transform(new ConvI2LNode(diff)); 318 #endif 319 diff = _igvn.transform(new LShiftXNode(diff, _igvn.intcon(shift))); 320 321 Node* off = _igvn.transform(new AddXNode(_igvn.MakeConX(offset), diff)); 322 Node* base = ac->in(ArrayCopyNode::Src); 323 adr = _igvn.transform(new AddPNode(base, base, off)); 324 adr_type = _igvn.type(base)->is_ptr()->add_offset(Type::OffsetBot); 325 if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) { 326 // Non constant offset in the array: we can't statically 327 // determine the value 328 return nullptr; 329 } 330 } 331 MergeMemNode* mergemen = _igvn.transform(MergeMemNode::make(mem))->as_MergeMem(); 332 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); 333 res = ArrayCopyNode::load(bs, &_igvn, ctl, mergemen, adr, adr_type, type, bt); 334 } 335 } 336 if (res != nullptr) { 337 if (ftype->isa_narrowoop()) { 338 // PhaseMacroExpand::scalar_replacement adds DecodeN nodes 339 res = _igvn.transform(new EncodePNode(res, ftype)); 340 } 341 return res; 342 } 343 return nullptr; 344 } 345 346 // 347 // Given a Memory Phi, compute a value Phi containing the values from stores 348 // on the input paths. 349 // Note: this function is recursive, its depth is limited by the "level" argument 350 // Returns the computed Phi, or null if it cannot compute it. 351 Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, AllocateNode *alloc, Node_Stack *value_phis, int level) { 352 assert(mem->is_Phi(), "sanity"); 353 int alias_idx = C->get_alias_index(adr_t); 354 int offset = adr_t->offset(); 355 int instance_id = adr_t->instance_id(); 356 357 // Check if an appropriate value phi already exists. 358 Node* region = mem->in(0); 359 for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) { 360 Node* phi = region->fast_out(k); 361 if (phi->is_Phi() && phi != mem && 362 phi->as_Phi()->is_same_inst_field(phi_type, (int)mem->_idx, instance_id, alias_idx, offset)) { 363 return phi; 364 } 365 } 366 // Check if an appropriate new value phi already exists. 367 Node* new_phi = value_phis->find(mem->_idx); 368 if (new_phi != nullptr) 369 return new_phi; 370 371 if (level <= 0) { 372 return nullptr; // Give up: phi tree too deep 373 } 374 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory); 375 Node *alloc_mem = alloc->proj_out_or_null(TypeFunc::Memory, /*io_use:*/false); 376 assert(alloc_mem != nullptr, "Allocation without a memory projection."); 377 378 uint length = mem->req(); 379 GrowableArray <Node *> values(length, length, nullptr); 380 381 // create a new Phi for the value 382 PhiNode *phi = new PhiNode(mem->in(0), phi_type, nullptr, mem->_idx, instance_id, alias_idx, offset); 383 transform_later(phi); 384 value_phis->push(phi, mem->_idx); 385 386 for (uint j = 1; j < length; j++) { 387 Node *in = mem->in(j); 388 if (in == nullptr || in->is_top()) { 389 values.at_put(j, in); 390 } else { 391 Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn); 392 if (val == start_mem || val == alloc_mem) { 393 // hit a sentinel, return appropriate 0 value 394 values.at_put(j, _igvn.zerocon(ft)); 395 continue; 396 } 397 if (val->is_Initialize()) { 398 val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn); 399 } 400 if (val == nullptr) { 401 return nullptr; // can't find a value on this path 402 } 403 if (val == mem) { 404 values.at_put(j, mem); 405 } else if (val->is_Store()) { 406 Node* n = val->in(MemNode::ValueIn); 407 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); 408 n = bs->step_over_gc_barrier(n); 409 if (is_subword_type(ft)) { 410 n = Compile::narrow_value(ft, n, phi_type, &_igvn, true); 411 } 412 values.at_put(j, n); 413 } else if(val->is_Proj() && val->in(0) == alloc) { 414 values.at_put(j, _igvn.zerocon(ft)); 415 } else if (val->is_Phi()) { 416 val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1); 417 if (val == nullptr) { 418 return nullptr; 419 } 420 values.at_put(j, val); 421 } else if (val->Opcode() == Op_SCMemProj) { 422 assert(val->in(0)->is_LoadStore() || 423 val->in(0)->Opcode() == Op_EncodeISOArray || 424 val->in(0)->Opcode() == Op_StrCompressedCopy, "sanity"); 425 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field"); 426 return nullptr; 427 } else if (val->is_ArrayCopy()) { 428 Node* res = make_arraycopy_load(val->as_ArrayCopy(), offset, val->in(0), val->in(TypeFunc::Memory), ft, phi_type, alloc); 429 if (res == nullptr) { 430 return nullptr; 431 } 432 values.at_put(j, res); 433 } else { 434 DEBUG_ONLY( val->dump(); ) 435 assert(false, "unknown node on this path"); 436 return nullptr; // unknown node on this path 437 } 438 } 439 } 440 // Set Phi's inputs 441 for (uint j = 1; j < length; j++) { 442 if (values.at(j) == mem) { 443 phi->init_req(j, phi); 444 } else { 445 phi->init_req(j, values.at(j)); 446 } 447 } 448 return phi; 449 } 450 451 // Search the last value stored into the object's field. 452 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, Node *sfpt_ctl, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, AllocateNode *alloc) { 453 assert(adr_t->is_known_instance_field(), "instance required"); 454 int instance_id = adr_t->instance_id(); 455 assert((uint)instance_id == alloc->_idx, "wrong allocation"); 456 457 int alias_idx = C->get_alias_index(adr_t); 458 int offset = adr_t->offset(); 459 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory); 460 Node *alloc_ctrl = alloc->in(TypeFunc::Control); 461 Node *alloc_mem = alloc->proj_out_or_null(TypeFunc::Memory, /*io_use:*/false); 462 assert(alloc_mem != nullptr, "Allocation without a memory projection."); 463 VectorSet visited; 464 465 bool done = sfpt_mem == alloc_mem; 466 Node *mem = sfpt_mem; 467 while (!done) { 468 if (visited.test_set(mem->_idx)) { 469 return nullptr; // found a loop, give up 470 } 471 mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn); 472 if (mem == start_mem || mem == alloc_mem) { 473 done = true; // hit a sentinel, return appropriate 0 value 474 } else if (mem->is_Initialize()) { 475 mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn); 476 if (mem == nullptr) { 477 done = true; // Something go wrong. 478 } else if (mem->is_Store()) { 479 const TypePtr* atype = mem->as_Store()->adr_type(); 480 assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice"); 481 done = true; 482 } 483 } else if (mem->is_Store()) { 484 const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr(); 485 assert(atype != nullptr, "address type must be oopptr"); 486 assert(C->get_alias_index(atype) == alias_idx && 487 atype->is_known_instance_field() && atype->offset() == offset && 488 atype->instance_id() == instance_id, "store is correct memory slice"); 489 done = true; 490 } else if (mem->is_Phi()) { 491 // try to find a phi's unique input 492 Node *unique_input = nullptr; 493 Node *top = C->top(); 494 for (uint i = 1; i < mem->req(); i++) { 495 Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn); 496 if (n == nullptr || n == top || n == mem) { 497 continue; 498 } else if (unique_input == nullptr) { 499 unique_input = n; 500 } else if (unique_input != n) { 501 unique_input = top; 502 break; 503 } 504 } 505 if (unique_input != nullptr && unique_input != top) { 506 mem = unique_input; 507 } else { 508 done = true; 509 } 510 } else if (mem->is_ArrayCopy()) { 511 done = true; 512 } else { 513 DEBUG_ONLY( mem->dump(); ) 514 assert(false, "unexpected node"); 515 } 516 } 517 if (mem != nullptr) { 518 if (mem == start_mem || mem == alloc_mem) { 519 // hit a sentinel, return appropriate 0 value 520 return _igvn.zerocon(ft); 521 } else if (mem->is_Store()) { 522 Node* n = mem->in(MemNode::ValueIn); 523 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); 524 n = bs->step_over_gc_barrier(n); 525 return n; 526 } else if (mem->is_Phi()) { 527 // attempt to produce a Phi reflecting the values on the input paths of the Phi 528 Node_Stack value_phis(8); 529 Node* phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit); 530 if (phi != nullptr) { 531 return phi; 532 } else { 533 // Kill all new Phis 534 while(value_phis.is_nonempty()) { 535 Node* n = value_phis.node(); 536 _igvn.replace_node(n, C->top()); 537 value_phis.pop(); 538 } 539 } 540 } else if (mem->is_ArrayCopy()) { 541 Node* ctl = mem->in(0); 542 Node* m = mem->in(TypeFunc::Memory); 543 if (sfpt_ctl->is_Proj() && sfpt_ctl->as_Proj()->is_uncommon_trap_proj()) { 544 // pin the loads in the uncommon trap path 545 ctl = sfpt_ctl; 546 m = sfpt_mem; 547 } 548 return make_arraycopy_load(mem->as_ArrayCopy(), offset, ctl, m, ft, ftype, alloc); 549 } 550 } 551 // Something go wrong. 552 return nullptr; 553 } 554 555 // Check the possibility of scalar replacement. 556 bool PhaseMacroExpand::can_eliminate_allocation(PhaseIterGVN* igvn, AllocateNode *alloc, GrowableArray <SafePointNode *>* safepoints) { 557 // Scan the uses of the allocation to check for anything that would 558 // prevent us from eliminating it. 559 NOT_PRODUCT( const char* fail_eliminate = nullptr; ) 560 DEBUG_ONLY( Node* disq_node = nullptr; ) 561 bool can_eliminate = true; 562 bool reduce_merge_precheck = (safepoints == nullptr); 563 564 Node* res = alloc->result_cast(); 565 const TypeOopPtr* res_type = nullptr; 566 if (res == nullptr) { 567 // All users were eliminated. 568 } else if (!res->is_CheckCastPP()) { 569 NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";) 570 can_eliminate = false; 571 } else { 572 res_type = igvn->type(res)->isa_oopptr(); 573 if (res_type == nullptr) { 574 NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";) 575 can_eliminate = false; 576 } else if (res_type->isa_aryptr()) { 577 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1); 578 if (length < 0) { 579 NOT_PRODUCT(fail_eliminate = "Array's size is not constant";) 580 can_eliminate = false; 581 } 582 } 583 } 584 585 if (can_eliminate && res != nullptr) { 586 BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2(); 587 for (DUIterator_Fast jmax, j = res->fast_outs(jmax); 588 j < jmax && can_eliminate; j++) { 589 Node* use = res->fast_out(j); 590 591 if (use->is_AddP()) { 592 const TypePtr* addp_type = igvn->type(use)->is_ptr(); 593 int offset = addp_type->offset(); 594 595 if (offset == Type::OffsetTop || offset == Type::OffsetBot) { 596 NOT_PRODUCT(fail_eliminate = "Undefined field reference";) 597 can_eliminate = false; 598 break; 599 } 600 for (DUIterator_Fast kmax, k = use->fast_outs(kmax); 601 k < kmax && can_eliminate; k++) { 602 Node* n = use->fast_out(k); 603 if (!n->is_Store() && n->Opcode() != Op_CastP2X && !bs->is_gc_pre_barrier_node(n) && !reduce_merge_precheck) { 604 DEBUG_ONLY(disq_node = n;) 605 if (n->is_Load() || n->is_LoadStore()) { 606 NOT_PRODUCT(fail_eliminate = "Field load";) 607 } else { 608 NOT_PRODUCT(fail_eliminate = "Not store field reference";) 609 } 610 can_eliminate = false; 611 } 612 } 613 } else if (use->is_ArrayCopy() && 614 (use->as_ArrayCopy()->is_clonebasic() || 615 use->as_ArrayCopy()->is_arraycopy_validated() || 616 use->as_ArrayCopy()->is_copyof_validated() || 617 use->as_ArrayCopy()->is_copyofrange_validated()) && 618 use->in(ArrayCopyNode::Dest) == res) { 619 // ok to eliminate 620 } else if (use->is_SafePoint()) { 621 SafePointNode* sfpt = use->as_SafePoint(); 622 if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) { 623 // Object is passed as argument. 624 DEBUG_ONLY(disq_node = use;) 625 NOT_PRODUCT(fail_eliminate = "Object is passed as argument";) 626 can_eliminate = false; 627 } 628 Node* sfptMem = sfpt->memory(); 629 if (sfptMem == nullptr || sfptMem->is_top()) { 630 DEBUG_ONLY(disq_node = use;) 631 NOT_PRODUCT(fail_eliminate = "null or TOP memory";) 632 can_eliminate = false; 633 } else if (!reduce_merge_precheck) { 634 safepoints->append_if_missing(sfpt); 635 } 636 } else if (reduce_merge_precheck && (use->is_Phi() || use->is_EncodeP() || use->Opcode() == Op_MemBarRelease)) { 637 // Nothing to do 638 } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark 639 if (use->is_Phi()) { 640 if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) { 641 NOT_PRODUCT(fail_eliminate = "Object is return value";) 642 } else { 643 NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";) 644 } 645 DEBUG_ONLY(disq_node = use;) 646 } else { 647 if (use->Opcode() == Op_Return) { 648 NOT_PRODUCT(fail_eliminate = "Object is return value";) 649 } else { 650 NOT_PRODUCT(fail_eliminate = "Object is referenced by node";) 651 } 652 DEBUG_ONLY(disq_node = use;) 653 } 654 can_eliminate = false; 655 } 656 } 657 } 658 659 #ifndef PRODUCT 660 if (PrintEliminateAllocations && safepoints != nullptr) { 661 if (can_eliminate) { 662 tty->print("Scalar "); 663 if (res == nullptr) 664 alloc->dump(); 665 else 666 res->dump(); 667 } else if (alloc->_is_scalar_replaceable) { 668 tty->print("NotScalar (%s)", fail_eliminate); 669 if (res == nullptr) 670 alloc->dump(); 671 else 672 res->dump(); 673 #ifdef ASSERT 674 if (disq_node != nullptr) { 675 tty->print(" >>>> "); 676 disq_node->dump(); 677 } 678 #endif /*ASSERT*/ 679 } 680 } 681 682 if (TraceReduceAllocationMerges && !can_eliminate && reduce_merge_precheck) { 683 tty->print_cr("\tCan't eliminate allocation because '%s': ", fail_eliminate != nullptr ? fail_eliminate : ""); 684 DEBUG_ONLY(if (disq_node != nullptr) disq_node->dump();) 685 } 686 #endif 687 return can_eliminate; 688 } 689 690 void PhaseMacroExpand::undo_previous_scalarizations(GrowableArray <SafePointNode *> safepoints_done, AllocateNode* alloc) { 691 Node* res = alloc->result_cast(); 692 int nfields = 0; 693 assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result"); 694 695 if (res != nullptr) { 696 const TypeOopPtr* res_type = _igvn.type(res)->isa_oopptr(); 697 698 if (res_type->isa_instptr()) { 699 // find the fields of the class which will be needed for safepoint debug information 700 ciInstanceKlass* iklass = res_type->is_instptr()->instance_klass(); 701 nfields = iklass->nof_nonstatic_fields(); 702 } else { 703 // find the array's elements which will be needed for safepoint debug information 704 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1); 705 assert(nfields >= 0, "must be an array klass."); 706 } 707 } 708 709 // rollback processed safepoints 710 while (safepoints_done.length() > 0) { 711 SafePointNode* sfpt_done = safepoints_done.pop(); 712 // remove any extra entries we added to the safepoint 713 uint last = sfpt_done->req() - 1; 714 for (int k = 0; k < nfields; k++) { 715 sfpt_done->del_req(last--); 716 } 717 JVMState *jvms = sfpt_done->jvms(); 718 jvms->set_endoff(sfpt_done->req()); 719 // Now make a pass over the debug information replacing any references 720 // to SafePointScalarObjectNode with the allocated object. 721 int start = jvms->debug_start(); 722 int end = jvms->debug_end(); 723 for (int i = start; i < end; i++) { 724 if (sfpt_done->in(i)->is_SafePointScalarObject()) { 725 SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject(); 726 if (scobj->first_index(jvms) == sfpt_done->req() && 727 scobj->n_fields() == (uint)nfields) { 728 assert(scobj->alloc() == alloc, "sanity"); 729 sfpt_done->set_req(i, res); 730 } 731 } 732 } 733 _igvn._worklist.push(sfpt_done); 734 } 735 } 736 737 SafePointScalarObjectNode* PhaseMacroExpand::create_scalarized_object_description(AllocateNode *alloc, SafePointNode* sfpt) { 738 // Fields of scalar objs are referenced only at the end 739 // of regular debuginfo at the last (youngest) JVMS. 740 // Record relative start index. 741 ciInstanceKlass* iklass = nullptr; 742 BasicType basic_elem_type = T_ILLEGAL; 743 const Type* field_type = nullptr; 744 const TypeOopPtr* res_type = nullptr; 745 int nfields = 0; 746 int array_base = 0; 747 int element_size = 0; 748 uint first_ind = (sfpt->req() - sfpt->jvms()->scloff()); 749 Node* res = alloc->result_cast(); 750 751 assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result"); 752 assert(sfpt->jvms() != nullptr, "missed JVMS"); 753 754 if (res != nullptr) { // Could be null when there are no users 755 res_type = _igvn.type(res)->isa_oopptr(); 756 757 if (res_type->isa_instptr()) { 758 // find the fields of the class which will be needed for safepoint debug information 759 iklass = res_type->is_instptr()->instance_klass(); 760 nfields = iklass->nof_nonstatic_fields(); 761 } else { 762 // find the array's elements which will be needed for safepoint debug information 763 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1); 764 assert(nfields >= 0, "must be an array klass."); 765 basic_elem_type = res_type->is_aryptr()->elem()->array_element_basic_type(); 766 array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type); 767 element_size = type2aelembytes(basic_elem_type); 768 field_type = res_type->is_aryptr()->elem(); 769 } 770 } 771 772 SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type, alloc, first_ind, sfpt->jvms()->depth(), nfields); 773 sobj->init_req(0, C->root()); 774 transform_later(sobj); 775 776 // Scan object's fields adding an input to the safepoint for each field. 777 for (int j = 0; j < nfields; j++) { 778 intptr_t offset; 779 ciField* field = nullptr; 780 if (iklass != nullptr) { 781 field = iklass->nonstatic_field_at(j); 782 offset = field->offset_in_bytes(); 783 ciType* elem_type = field->type(); 784 basic_elem_type = field->layout_type(); 785 786 // The next code is taken from Parse::do_get_xxx(). 787 if (is_reference_type(basic_elem_type)) { 788 if (!elem_type->is_loaded()) { 789 field_type = TypeInstPtr::BOTTOM; 790 } else if (field != nullptr && field->is_static_constant()) { 791 ciObject* con = field->constant_value().as_object(); 792 // Do not "join" in the previous type; it doesn't add value, 793 // and may yield a vacuous result if the field is of interface type. 794 field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr(); 795 assert(field_type != nullptr, "field singleton type must be consistent"); 796 } else { 797 field_type = TypeOopPtr::make_from_klass(elem_type->as_klass()); 798 } 799 if (UseCompressedOops) { 800 field_type = field_type->make_narrowoop(); 801 basic_elem_type = T_NARROWOOP; 802 } 803 } else { 804 field_type = Type::get_const_basic_type(basic_elem_type); 805 } 806 } else { 807 offset = array_base + j * (intptr_t)element_size; 808 } 809 810 const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr(); 811 812 Node *field_val = value_from_mem(sfpt->memory(), sfpt->control(), basic_elem_type, field_type, field_addr_type, alloc); 813 814 // We weren't able to find a value for this field, 815 // give up on eliminating this allocation. 816 if (field_val == nullptr) { 817 uint last = sfpt->req() - 1; 818 for (int k = 0; k < j; k++) { 819 sfpt->del_req(last--); 820 } 821 _igvn._worklist.push(sfpt); 822 823 #ifndef PRODUCT 824 if (PrintEliminateAllocations) { 825 if (field != nullptr) { 826 tty->print("=== At SafePoint node %d can't find value of field: ", sfpt->_idx); 827 field->print(); 828 int field_idx = C->get_alias_index(field_addr_type); 829 tty->print(" (alias_idx=%d)", field_idx); 830 } else { // Array's element 831 tty->print("=== At SafePoint node %d can't find value of array element [%d]", sfpt->_idx, j); 832 } 833 tty->print(", which prevents elimination of: "); 834 if (res == nullptr) 835 alloc->dump(); 836 else 837 res->dump(); 838 } 839 #endif 840 841 return nullptr; 842 } 843 844 if (UseCompressedOops && field_type->isa_narrowoop()) { 845 // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation 846 // to be able scalar replace the allocation. 847 if (field_val->is_EncodeP()) { 848 field_val = field_val->in(1); 849 } else { 850 field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type())); 851 } 852 } 853 sfpt->add_req(field_val); 854 } 855 856 sfpt->jvms()->set_endoff(sfpt->req()); 857 858 return sobj; 859 } 860 861 // Do scalar replacement. 862 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) { 863 GrowableArray <SafePointNode *> safepoints_done; 864 Node* res = alloc->result_cast(); 865 assert(res == nullptr || res->is_CheckCastPP(), "unexpected AllocateNode result"); 866 867 // Process the safepoint uses 868 while (safepoints.length() > 0) { 869 SafePointNode* sfpt = safepoints.pop(); 870 SafePointScalarObjectNode* sobj = create_scalarized_object_description(alloc, sfpt); 871 872 if (sobj == nullptr) { 873 undo_previous_scalarizations(safepoints_done, alloc); 874 return false; 875 } 876 877 // Now make a pass over the debug information replacing any references 878 // to the allocated object with "sobj" 879 JVMState *jvms = sfpt->jvms(); 880 sfpt->replace_edges_in_range(res, sobj, jvms->debug_start(), jvms->debug_end(), &_igvn); 881 _igvn._worklist.push(sfpt); 882 883 // keep it for rollback 884 safepoints_done.append_if_missing(sfpt); 885 } 886 887 return true; 888 } 889 890 static void disconnect_projections(MultiNode* n, PhaseIterGVN& igvn) { 891 Node* ctl_proj = n->proj_out_or_null(TypeFunc::Control); 892 Node* mem_proj = n->proj_out_or_null(TypeFunc::Memory); 893 if (ctl_proj != nullptr) { 894 igvn.replace_node(ctl_proj, n->in(0)); 895 } 896 if (mem_proj != nullptr) { 897 igvn.replace_node(mem_proj, n->in(TypeFunc::Memory)); 898 } 899 } 900 901 // Process users of eliminated allocation. 902 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) { 903 Node* res = alloc->result_cast(); 904 if (res != nullptr) { 905 for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) { 906 Node *use = res->last_out(j); 907 uint oc1 = res->outcnt(); 908 909 if (use->is_AddP()) { 910 for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) { 911 Node *n = use->last_out(k); 912 uint oc2 = use->outcnt(); 913 if (n->is_Store()) { 914 #ifdef ASSERT 915 // Verify that there is no dependent MemBarVolatile nodes, 916 // they should be removed during IGVN, see MemBarNode::Ideal(). 917 for (DUIterator_Fast pmax, p = n->fast_outs(pmax); 918 p < pmax; p++) { 919 Node* mb = n->fast_out(p); 920 assert(mb->is_Initialize() || !mb->is_MemBar() || 921 mb->req() <= MemBarNode::Precedent || 922 mb->in(MemBarNode::Precedent) != n, 923 "MemBarVolatile should be eliminated for non-escaping object"); 924 } 925 #endif 926 _igvn.replace_node(n, n->in(MemNode::Memory)); 927 } else { 928 eliminate_gc_barrier(n); 929 } 930 k -= (oc2 - use->outcnt()); 931 } 932 _igvn.remove_dead_node(use); 933 } else if (use->is_ArrayCopy()) { 934 // Disconnect ArrayCopy node 935 ArrayCopyNode* ac = use->as_ArrayCopy(); 936 if (ac->is_clonebasic()) { 937 Node* membar_after = ac->proj_out(TypeFunc::Control)->unique_ctrl_out(); 938 disconnect_projections(ac, _igvn); 939 assert(alloc->in(TypeFunc::Memory)->is_Proj() && alloc->in(TypeFunc::Memory)->in(0)->Opcode() == Op_MemBarCPUOrder, "mem barrier expected before allocation"); 940 Node* membar_before = alloc->in(TypeFunc::Memory)->in(0); 941 disconnect_projections(membar_before->as_MemBar(), _igvn); 942 if (membar_after->is_MemBar()) { 943 disconnect_projections(membar_after->as_MemBar(), _igvn); 944 } 945 } else { 946 assert(ac->is_arraycopy_validated() || 947 ac->is_copyof_validated() || 948 ac->is_copyofrange_validated(), "unsupported"); 949 CallProjections callprojs; 950 ac->extract_projections(&callprojs, true); 951 952 _igvn.replace_node(callprojs.fallthrough_ioproj, ac->in(TypeFunc::I_O)); 953 _igvn.replace_node(callprojs.fallthrough_memproj, ac->in(TypeFunc::Memory)); 954 _igvn.replace_node(callprojs.fallthrough_catchproj, ac->in(TypeFunc::Control)); 955 956 // Set control to top. IGVN will remove the remaining projections 957 ac->set_req(0, top()); 958 ac->replace_edge(res, top(), &_igvn); 959 960 // Disconnect src right away: it can help find new 961 // opportunities for allocation elimination 962 Node* src = ac->in(ArrayCopyNode::Src); 963 ac->replace_edge(src, top(), &_igvn); 964 // src can be top at this point if src and dest of the 965 // arraycopy were the same 966 if (src->outcnt() == 0 && !src->is_top()) { 967 _igvn.remove_dead_node(src); 968 } 969 } 970 _igvn._worklist.push(ac); 971 } else { 972 eliminate_gc_barrier(use); 973 } 974 j -= (oc1 - res->outcnt()); 975 } 976 assert(res->outcnt() == 0, "all uses of allocated objects must be deleted"); 977 _igvn.remove_dead_node(res); 978 } 979 980 // 981 // Process other users of allocation's projections 982 // 983 if (_callprojs.resproj != nullptr && _callprojs.resproj->outcnt() != 0) { 984 // First disconnect stores captured by Initialize node. 985 // If Initialize node is eliminated first in the following code, 986 // it will kill such stores and DUIterator_Last will assert. 987 for (DUIterator_Fast jmax, j = _callprojs.resproj->fast_outs(jmax); j < jmax; j++) { 988 Node* use = _callprojs.resproj->fast_out(j); 989 if (use->is_AddP()) { 990 // raw memory addresses used only by the initialization 991 _igvn.replace_node(use, C->top()); 992 --j; --jmax; 993 } 994 } 995 for (DUIterator_Last jmin, j = _callprojs.resproj->last_outs(jmin); j >= jmin; ) { 996 Node* use = _callprojs.resproj->last_out(j); 997 uint oc1 = _callprojs.resproj->outcnt(); 998 if (use->is_Initialize()) { 999 // Eliminate Initialize node. 1000 InitializeNode *init = use->as_Initialize(); 1001 assert(init->outcnt() <= 2, "only a control and memory projection expected"); 1002 Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control); 1003 if (ctrl_proj != nullptr) { 1004 _igvn.replace_node(ctrl_proj, init->in(TypeFunc::Control)); 1005 #ifdef ASSERT 1006 // If the InitializeNode has no memory out, it will die, and tmp will become null 1007 Node* tmp = init->in(TypeFunc::Control); 1008 assert(tmp == nullptr || tmp == _callprojs.fallthrough_catchproj, "allocation control projection"); 1009 #endif 1010 } 1011 Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory); 1012 if (mem_proj != nullptr) { 1013 Node *mem = init->in(TypeFunc::Memory); 1014 #ifdef ASSERT 1015 if (mem->is_MergeMem()) { 1016 assert(mem->in(TypeFunc::Memory) == _callprojs.fallthrough_memproj, "allocation memory projection"); 1017 } else { 1018 assert(mem == _callprojs.fallthrough_memproj, "allocation memory projection"); 1019 } 1020 #endif 1021 _igvn.replace_node(mem_proj, mem); 1022 } 1023 } else { 1024 assert(false, "only Initialize or AddP expected"); 1025 } 1026 j -= (oc1 - _callprojs.resproj->outcnt()); 1027 } 1028 } 1029 if (_callprojs.fallthrough_catchproj != nullptr) { 1030 _igvn.replace_node(_callprojs.fallthrough_catchproj, alloc->in(TypeFunc::Control)); 1031 } 1032 if (_callprojs.fallthrough_memproj != nullptr) { 1033 _igvn.replace_node(_callprojs.fallthrough_memproj, alloc->in(TypeFunc::Memory)); 1034 } 1035 if (_callprojs.catchall_memproj != nullptr) { 1036 _igvn.replace_node(_callprojs.catchall_memproj, C->top()); 1037 } 1038 if (_callprojs.fallthrough_ioproj != nullptr) { 1039 _igvn.replace_node(_callprojs.fallthrough_ioproj, alloc->in(TypeFunc::I_O)); 1040 } 1041 if (_callprojs.catchall_ioproj != nullptr) { 1042 _igvn.replace_node(_callprojs.catchall_ioproj, C->top()); 1043 } 1044 if (_callprojs.catchall_catchproj != nullptr) { 1045 _igvn.replace_node(_callprojs.catchall_catchproj, C->top()); 1046 } 1047 } 1048 1049 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) { 1050 // If reallocation fails during deoptimization we'll pop all 1051 // interpreter frames for this compiled frame and that won't play 1052 // nice with JVMTI popframe. 1053 // We avoid this issue by eager reallocation when the popframe request 1054 // is received. 1055 if (!EliminateAllocations || !alloc->_is_non_escaping) { 1056 return false; 1057 } 1058 Node* klass = alloc->in(AllocateNode::KlassNode); 1059 const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr(); 1060 Node* res = alloc->result_cast(); 1061 // Eliminate boxing allocations which are not used 1062 // regardless scalar replaceable status. 1063 bool boxing_alloc = C->eliminate_boxing() && 1064 tklass->isa_instklassptr() && 1065 tklass->is_instklassptr()->instance_klass()->is_box_klass(); 1066 if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != nullptr))) { 1067 return false; 1068 } 1069 1070 alloc->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/); 1071 1072 GrowableArray <SafePointNode *> safepoints; 1073 if (!can_eliminate_allocation(&_igvn, alloc, &safepoints)) { 1074 return false; 1075 } 1076 1077 if (!alloc->_is_scalar_replaceable) { 1078 assert(res == nullptr, "sanity"); 1079 // We can only eliminate allocation if all debug info references 1080 // are already replaced with SafePointScalarObject because 1081 // we can't search for a fields value without instance_id. 1082 if (safepoints.length() > 0) { 1083 return false; 1084 } 1085 } 1086 1087 if (!scalar_replacement(alloc, safepoints)) { 1088 return false; 1089 } 1090 1091 CompileLog* log = C->log(); 1092 if (log != nullptr) { 1093 log->head("eliminate_allocation type='%d'", 1094 log->identify(tklass->exact_klass())); 1095 JVMState* p = alloc->jvms(); 1096 while (p != nullptr) { 1097 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method())); 1098 p = p->caller(); 1099 } 1100 log->tail("eliminate_allocation"); 1101 } 1102 1103 process_users_of_allocation(alloc); 1104 1105 #ifndef PRODUCT 1106 if (PrintEliminateAllocations) { 1107 if (alloc->is_AllocateArray()) 1108 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx); 1109 else 1110 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx); 1111 } 1112 #endif 1113 1114 return true; 1115 } 1116 1117 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) { 1118 // EA should remove all uses of non-escaping boxing node. 1119 if (!C->eliminate_boxing() || boxing->proj_out_or_null(TypeFunc::Parms) != nullptr) { 1120 return false; 1121 } 1122 1123 assert(boxing->result_cast() == nullptr, "unexpected boxing node result"); 1124 1125 boxing->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/); 1126 1127 const TypeTuple* r = boxing->tf()->range(); 1128 assert(r->cnt() > TypeFunc::Parms, "sanity"); 1129 const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr(); 1130 assert(t != nullptr, "sanity"); 1131 1132 CompileLog* log = C->log(); 1133 if (log != nullptr) { 1134 log->head("eliminate_boxing type='%d'", 1135 log->identify(t->instance_klass())); 1136 JVMState* p = boxing->jvms(); 1137 while (p != nullptr) { 1138 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method())); 1139 p = p->caller(); 1140 } 1141 log->tail("eliminate_boxing"); 1142 } 1143 1144 process_users_of_allocation(boxing); 1145 1146 #ifndef PRODUCT 1147 if (PrintEliminateAllocations) { 1148 tty->print("++++ Eliminated: %d ", boxing->_idx); 1149 boxing->method()->print_short_name(tty); 1150 tty->cr(); 1151 } 1152 #endif 1153 1154 return true; 1155 } 1156 1157 1158 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) { 1159 Node* adr = basic_plus_adr(base, offset); 1160 const TypePtr* adr_type = adr->bottom_type()->is_ptr(); 1161 Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered); 1162 transform_later(value); 1163 return value; 1164 } 1165 1166 1167 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) { 1168 Node* adr = basic_plus_adr(base, offset); 1169 mem = StoreNode::make(_igvn, ctl, mem, adr, nullptr, value, bt, MemNode::unordered); 1170 transform_later(mem); 1171 return mem; 1172 } 1173 1174 //============================================================================= 1175 // 1176 // A L L O C A T I O N 1177 // 1178 // Allocation attempts to be fast in the case of frequent small objects. 1179 // It breaks down like this: 1180 // 1181 // 1) Size in doublewords is computed. This is a constant for objects and 1182 // variable for most arrays. Doubleword units are used to avoid size 1183 // overflow of huge doubleword arrays. We need doublewords in the end for 1184 // rounding. 1185 // 1186 // 2) Size is checked for being 'too large'. Too-large allocations will go 1187 // the slow path into the VM. The slow path can throw any required 1188 // exceptions, and does all the special checks for very large arrays. The 1189 // size test can constant-fold away for objects. For objects with 1190 // finalizers it constant-folds the otherway: you always go slow with 1191 // finalizers. 1192 // 1193 // 3) If NOT using TLABs, this is the contended loop-back point. 1194 // Load-Locked the heap top. If using TLABs normal-load the heap top. 1195 // 1196 // 4) Check that heap top + size*8 < max. If we fail go the slow ` route. 1197 // NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish 1198 // "size*8" we always enter the VM, where "largish" is a constant picked small 1199 // enough that there's always space between the eden max and 4Gig (old space is 1200 // there so it's quite large) and large enough that the cost of entering the VM 1201 // is dwarfed by the cost to initialize the space. 1202 // 1203 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back 1204 // down. If contended, repeat at step 3. If using TLABs normal-store 1205 // adjusted heap top back down; there is no contention. 1206 // 1207 // 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark 1208 // fields. 1209 // 1210 // 7) Merge with the slow-path; cast the raw memory pointer to the correct 1211 // oop flavor. 1212 // 1213 //============================================================================= 1214 // FastAllocateSizeLimit value is in DOUBLEWORDS. 1215 // Allocations bigger than this always go the slow route. 1216 // This value must be small enough that allocation attempts that need to 1217 // trigger exceptions go the slow route. Also, it must be small enough so 1218 // that heap_top + size_in_bytes does not wrap around the 4Gig limit. 1219 //=============================================================================j// 1220 // %%% Here is an old comment from parseHelper.cpp; is it outdated? 1221 // The allocator will coalesce int->oop copies away. See comment in 1222 // coalesce.cpp about how this works. It depends critically on the exact 1223 // code shape produced here, so if you are changing this code shape 1224 // make sure the GC info for the heap-top is correct in and around the 1225 // slow-path call. 1226 // 1227 1228 void PhaseMacroExpand::expand_allocate_common( 1229 AllocateNode* alloc, // allocation node to be expanded 1230 Node* length, // array length for an array allocation 1231 const TypeFunc* slow_call_type, // Type of slow call 1232 address slow_call_address, // Address of slow call 1233 Node* valid_length_test // whether length is valid or not 1234 ) 1235 { 1236 Node* ctrl = alloc->in(TypeFunc::Control); 1237 Node* mem = alloc->in(TypeFunc::Memory); 1238 Node* i_o = alloc->in(TypeFunc::I_O); 1239 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize); 1240 Node* klass_node = alloc->in(AllocateNode::KlassNode); 1241 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest); 1242 assert(ctrl != nullptr, "must have control"); 1243 1244 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results. 1245 // they will not be used if "always_slow" is set 1246 enum { slow_result_path = 1, fast_result_path = 2 }; 1247 Node *result_region = nullptr; 1248 Node *result_phi_rawmem = nullptr; 1249 Node *result_phi_rawoop = nullptr; 1250 Node *result_phi_i_o = nullptr; 1251 1252 // The initial slow comparison is a size check, the comparison 1253 // we want to do is a BoolTest::gt 1254 bool expand_fast_path = true; 1255 int tv = _igvn.find_int_con(initial_slow_test, -1); 1256 if (tv >= 0) { 1257 // InitialTest has constant result 1258 // 0 - can fit in TLAB 1259 // 1 - always too big or negative 1260 assert(tv <= 1, "0 or 1 if a constant"); 1261 expand_fast_path = (tv == 0); 1262 initial_slow_test = nullptr; 1263 } else { 1264 initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn); 1265 } 1266 1267 if (!UseTLAB) { 1268 // Force slow-path allocation 1269 expand_fast_path = false; 1270 initial_slow_test = nullptr; 1271 } 1272 1273 bool allocation_has_use = (alloc->result_cast() != nullptr); 1274 if (!allocation_has_use) { 1275 InitializeNode* init = alloc->initialization(); 1276 if (init != nullptr) { 1277 init->remove(&_igvn); 1278 } 1279 if (expand_fast_path && (initial_slow_test == nullptr)) { 1280 // Remove allocation node and return. 1281 // Size is a non-negative constant -> no initial check needed -> directly to fast path. 1282 // Also, no usages -> empty fast path -> no fall out to slow path -> nothing left. 1283 #ifndef PRODUCT 1284 if (PrintEliminateAllocations) { 1285 tty->print("NotUsed "); 1286 Node* res = alloc->proj_out_or_null(TypeFunc::Parms); 1287 if (res != nullptr) { 1288 res->dump(); 1289 } else { 1290 alloc->dump(); 1291 } 1292 } 1293 #endif 1294 yank_alloc_node(alloc); 1295 return; 1296 } 1297 } 1298 1299 enum { too_big_or_final_path = 1, need_gc_path = 2 }; 1300 Node *slow_region = nullptr; 1301 Node *toobig_false = ctrl; 1302 1303 // generate the initial test if necessary 1304 if (initial_slow_test != nullptr ) { 1305 assert (expand_fast_path, "Only need test if there is a fast path"); 1306 slow_region = new RegionNode(3); 1307 1308 // Now make the initial failure test. Usually a too-big test but 1309 // might be a TRUE for finalizers or a fancy class check for 1310 // newInstance0. 1311 IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN); 1312 transform_later(toobig_iff); 1313 // Plug the failing-too-big test into the slow-path region 1314 Node *toobig_true = new IfTrueNode( toobig_iff ); 1315 transform_later(toobig_true); 1316 slow_region ->init_req( too_big_or_final_path, toobig_true ); 1317 toobig_false = new IfFalseNode( toobig_iff ); 1318 transform_later(toobig_false); 1319 } else { 1320 // No initial test, just fall into next case 1321 assert(allocation_has_use || !expand_fast_path, "Should already have been handled"); 1322 toobig_false = ctrl; 1323 debug_only(slow_region = NodeSentinel); 1324 } 1325 1326 // If we are here there are several possibilities 1327 // - expand_fast_path is false - then only a slow path is expanded. That's it. 1328 // no_initial_check means a constant allocation. 1329 // - If check always evaluates to false -> expand_fast_path is false (see above) 1330 // - If check always evaluates to true -> directly into fast path (but may bailout to slowpath) 1331 // if !allocation_has_use the fast path is empty 1332 // if !allocation_has_use && no_initial_check 1333 // - Then there are no fastpath that can fall out to slowpath -> no allocation code at all. 1334 // removed by yank_alloc_node above. 1335 1336 Node *slow_mem = mem; // save the current memory state for slow path 1337 // generate the fast allocation code unless we know that the initial test will always go slow 1338 if (expand_fast_path) { 1339 // Fast path modifies only raw memory. 1340 if (mem->is_MergeMem()) { 1341 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw); 1342 } 1343 1344 // allocate the Region and Phi nodes for the result 1345 result_region = new RegionNode(3); 1346 result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM); 1347 result_phi_i_o = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch 1348 1349 // Grab regular I/O before optional prefetch may change it. 1350 // Slow-path does no I/O so just set it to the original I/O. 1351 result_phi_i_o->init_req(slow_result_path, i_o); 1352 1353 // Name successful fast-path variables 1354 Node* fast_oop_ctrl; 1355 Node* fast_oop_rawmem; 1356 if (allocation_has_use) { 1357 Node* needgc_ctrl = nullptr; 1358 result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM); 1359 1360 intx prefetch_lines = length != nullptr ? AllocatePrefetchLines : AllocateInstancePrefetchLines; 1361 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); 1362 Node* fast_oop = bs->obj_allocate(this, mem, toobig_false, size_in_bytes, i_o, needgc_ctrl, 1363 fast_oop_ctrl, fast_oop_rawmem, 1364 prefetch_lines); 1365 1366 if (initial_slow_test != nullptr) { 1367 // This completes all paths into the slow merge point 1368 slow_region->init_req(need_gc_path, needgc_ctrl); 1369 transform_later(slow_region); 1370 } else { 1371 // No initial slow path needed! 1372 // Just fall from the need-GC path straight into the VM call. 1373 slow_region = needgc_ctrl; 1374 } 1375 1376 InitializeNode* init = alloc->initialization(); 1377 fast_oop_rawmem = initialize_object(alloc, 1378 fast_oop_ctrl, fast_oop_rawmem, fast_oop, 1379 klass_node, length, size_in_bytes); 1380 expand_initialize_membar(alloc, init, fast_oop_ctrl, fast_oop_rawmem); 1381 expand_dtrace_alloc_probe(alloc, fast_oop, fast_oop_ctrl, fast_oop_rawmem); 1382 1383 result_phi_rawoop->init_req(fast_result_path, fast_oop); 1384 } else { 1385 assert (initial_slow_test != nullptr, "sanity"); 1386 fast_oop_ctrl = toobig_false; 1387 fast_oop_rawmem = mem; 1388 transform_later(slow_region); 1389 } 1390 1391 // Plug in the successful fast-path into the result merge point 1392 result_region ->init_req(fast_result_path, fast_oop_ctrl); 1393 result_phi_i_o ->init_req(fast_result_path, i_o); 1394 result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem); 1395 } else { 1396 slow_region = ctrl; 1397 result_phi_i_o = i_o; // Rename it to use in the following code. 1398 } 1399 1400 // Generate slow-path call 1401 CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address, 1402 OptoRuntime::stub_name(slow_call_address), 1403 TypePtr::BOTTOM); 1404 call->init_req(TypeFunc::Control, slow_region); 1405 call->init_req(TypeFunc::I_O, top()); // does no i/o 1406 call->init_req(TypeFunc::Memory, slow_mem); // may gc ptrs 1407 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr)); 1408 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr)); 1409 1410 call->init_req(TypeFunc::Parms+0, klass_node); 1411 if (length != nullptr) { 1412 call->init_req(TypeFunc::Parms+1, length); 1413 } 1414 1415 // Copy debug information and adjust JVMState information, then replace 1416 // allocate node with the call 1417 call->copy_call_debug_info(&_igvn, alloc); 1418 // For array allocations, copy the valid length check to the call node so Compile::final_graph_reshaping() can verify 1419 // that the call has the expected number of CatchProj nodes (in case the allocation always fails and the fallthrough 1420 // path dies). 1421 if (valid_length_test != nullptr) { 1422 call->add_req(valid_length_test); 1423 } 1424 if (expand_fast_path) { 1425 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON. 1426 } else { 1427 // Hook i_o projection to avoid its elimination during allocation 1428 // replacement (when only a slow call is generated). 1429 call->set_req(TypeFunc::I_O, result_phi_i_o); 1430 } 1431 _igvn.replace_node(alloc, call); 1432 transform_later(call); 1433 1434 // Identify the output projections from the allocate node and 1435 // adjust any references to them. 1436 // The control and io projections look like: 1437 // 1438 // v---Proj(ctrl) <-----+ v---CatchProj(ctrl) 1439 // Allocate Catch 1440 // ^---Proj(io) <-------+ ^---CatchProj(io) 1441 // 1442 // We are interested in the CatchProj nodes. 1443 // 1444 call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/); 1445 1446 // An allocate node has separate memory projections for the uses on 1447 // the control and i_o paths. Replace the control memory projection with 1448 // result_phi_rawmem (unless we are only generating a slow call when 1449 // both memory projections are combined) 1450 if (expand_fast_path && _callprojs.fallthrough_memproj != nullptr) { 1451 migrate_outs(_callprojs.fallthrough_memproj, result_phi_rawmem); 1452 } 1453 // Now change uses of catchall_memproj to use fallthrough_memproj and delete 1454 // catchall_memproj so we end up with a call that has only 1 memory projection. 1455 if (_callprojs.catchall_memproj != nullptr ) { 1456 if (_callprojs.fallthrough_memproj == nullptr) { 1457 _callprojs.fallthrough_memproj = new ProjNode(call, TypeFunc::Memory); 1458 transform_later(_callprojs.fallthrough_memproj); 1459 } 1460 migrate_outs(_callprojs.catchall_memproj, _callprojs.fallthrough_memproj); 1461 _igvn.remove_dead_node(_callprojs.catchall_memproj); 1462 } 1463 1464 // An allocate node has separate i_o projections for the uses on the control 1465 // and i_o paths. Always replace the control i_o projection with result i_o 1466 // otherwise incoming i_o become dead when only a slow call is generated 1467 // (it is different from memory projections where both projections are 1468 // combined in such case). 1469 if (_callprojs.fallthrough_ioproj != nullptr) { 1470 migrate_outs(_callprojs.fallthrough_ioproj, result_phi_i_o); 1471 } 1472 // Now change uses of catchall_ioproj to use fallthrough_ioproj and delete 1473 // catchall_ioproj so we end up with a call that has only 1 i_o projection. 1474 if (_callprojs.catchall_ioproj != nullptr ) { 1475 if (_callprojs.fallthrough_ioproj == nullptr) { 1476 _callprojs.fallthrough_ioproj = new ProjNode(call, TypeFunc::I_O); 1477 transform_later(_callprojs.fallthrough_ioproj); 1478 } 1479 migrate_outs(_callprojs.catchall_ioproj, _callprojs.fallthrough_ioproj); 1480 _igvn.remove_dead_node(_callprojs.catchall_ioproj); 1481 } 1482 1483 // if we generated only a slow call, we are done 1484 if (!expand_fast_path) { 1485 // Now we can unhook i_o. 1486 if (result_phi_i_o->outcnt() > 1) { 1487 call->set_req(TypeFunc::I_O, top()); 1488 } else { 1489 assert(result_phi_i_o->unique_ctrl_out() == call, "sanity"); 1490 // Case of new array with negative size known during compilation. 1491 // AllocateArrayNode::Ideal() optimization disconnect unreachable 1492 // following code since call to runtime will throw exception. 1493 // As result there will be no users of i_o after the call. 1494 // Leave i_o attached to this call to avoid problems in preceding graph. 1495 } 1496 return; 1497 } 1498 1499 if (_callprojs.fallthrough_catchproj != nullptr) { 1500 ctrl = _callprojs.fallthrough_catchproj->clone(); 1501 transform_later(ctrl); 1502 _igvn.replace_node(_callprojs.fallthrough_catchproj, result_region); 1503 } else { 1504 ctrl = top(); 1505 } 1506 Node *slow_result; 1507 if (_callprojs.resproj == nullptr) { 1508 // no uses of the allocation result 1509 slow_result = top(); 1510 } else { 1511 slow_result = _callprojs.resproj->clone(); 1512 transform_later(slow_result); 1513 _igvn.replace_node(_callprojs.resproj, result_phi_rawoop); 1514 } 1515 1516 // Plug slow-path into result merge point 1517 result_region->init_req( slow_result_path, ctrl); 1518 transform_later(result_region); 1519 if (allocation_has_use) { 1520 result_phi_rawoop->init_req(slow_result_path, slow_result); 1521 transform_later(result_phi_rawoop); 1522 } 1523 result_phi_rawmem->init_req(slow_result_path, _callprojs.fallthrough_memproj); 1524 transform_later(result_phi_rawmem); 1525 transform_later(result_phi_i_o); 1526 // This completes all paths into the result merge point 1527 } 1528 1529 // Remove alloc node that has no uses. 1530 void PhaseMacroExpand::yank_alloc_node(AllocateNode* alloc) { 1531 Node* ctrl = alloc->in(TypeFunc::Control); 1532 Node* mem = alloc->in(TypeFunc::Memory); 1533 Node* i_o = alloc->in(TypeFunc::I_O); 1534 1535 alloc->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/); 1536 if (_callprojs.resproj != nullptr) { 1537 for (DUIterator_Fast imax, i = _callprojs.resproj->fast_outs(imax); i < imax; i++) { 1538 Node* use = _callprojs.resproj->fast_out(i); 1539 use->isa_MemBar()->remove(&_igvn); 1540 --imax; 1541 --i; // back up iterator 1542 } 1543 assert(_callprojs.resproj->outcnt() == 0, "all uses must be deleted"); 1544 _igvn.remove_dead_node(_callprojs.resproj); 1545 } 1546 if (_callprojs.fallthrough_catchproj != nullptr) { 1547 migrate_outs(_callprojs.fallthrough_catchproj, ctrl); 1548 _igvn.remove_dead_node(_callprojs.fallthrough_catchproj); 1549 } 1550 if (_callprojs.catchall_catchproj != nullptr) { 1551 _igvn.rehash_node_delayed(_callprojs.catchall_catchproj); 1552 _callprojs.catchall_catchproj->set_req(0, top()); 1553 } 1554 if (_callprojs.fallthrough_proj != nullptr) { 1555 Node* catchnode = _callprojs.fallthrough_proj->unique_ctrl_out(); 1556 _igvn.remove_dead_node(catchnode); 1557 _igvn.remove_dead_node(_callprojs.fallthrough_proj); 1558 } 1559 if (_callprojs.fallthrough_memproj != nullptr) { 1560 migrate_outs(_callprojs.fallthrough_memproj, mem); 1561 _igvn.remove_dead_node(_callprojs.fallthrough_memproj); 1562 } 1563 if (_callprojs.fallthrough_ioproj != nullptr) { 1564 migrate_outs(_callprojs.fallthrough_ioproj, i_o); 1565 _igvn.remove_dead_node(_callprojs.fallthrough_ioproj); 1566 } 1567 if (_callprojs.catchall_memproj != nullptr) { 1568 _igvn.rehash_node_delayed(_callprojs.catchall_memproj); 1569 _callprojs.catchall_memproj->set_req(0, top()); 1570 } 1571 if (_callprojs.catchall_ioproj != nullptr) { 1572 _igvn.rehash_node_delayed(_callprojs.catchall_ioproj); 1573 _callprojs.catchall_ioproj->set_req(0, top()); 1574 } 1575 #ifndef PRODUCT 1576 if (PrintEliminateAllocations) { 1577 if (alloc->is_AllocateArray()) { 1578 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx); 1579 } else { 1580 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx); 1581 } 1582 } 1583 #endif 1584 _igvn.remove_dead_node(alloc); 1585 } 1586 1587 void PhaseMacroExpand::expand_initialize_membar(AllocateNode* alloc, InitializeNode* init, 1588 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem) { 1589 // If initialization is performed by an array copy, any required 1590 // MemBarStoreStore was already added. If the object does not 1591 // escape no need for a MemBarStoreStore. If the object does not 1592 // escape in its initializer and memory barrier (MemBarStoreStore or 1593 // stronger) is already added at exit of initializer, also no need 1594 // for a MemBarStoreStore. Otherwise we need a MemBarStoreStore 1595 // so that stores that initialize this object can't be reordered 1596 // with a subsequent store that makes this object accessible by 1597 // other threads. 1598 // Other threads include java threads and JVM internal threads 1599 // (for example concurrent GC threads). Current concurrent GC 1600 // implementation: G1 will not scan newly created object, 1601 // so it's safe to skip storestore barrier when allocation does 1602 // not escape. 1603 if (!alloc->does_not_escape_thread() && 1604 !alloc->is_allocation_MemBar_redundant() && 1605 (init == nullptr || !init->is_complete_with_arraycopy())) { 1606 if (init == nullptr || init->req() < InitializeNode::RawStores) { 1607 // No InitializeNode or no stores captured by zeroing 1608 // elimination. Simply add the MemBarStoreStore after object 1609 // initialization. 1610 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot); 1611 transform_later(mb); 1612 1613 mb->init_req(TypeFunc::Memory, fast_oop_rawmem); 1614 mb->init_req(TypeFunc::Control, fast_oop_ctrl); 1615 fast_oop_ctrl = new ProjNode(mb, TypeFunc::Control); 1616 transform_later(fast_oop_ctrl); 1617 fast_oop_rawmem = new ProjNode(mb, TypeFunc::Memory); 1618 transform_later(fast_oop_rawmem); 1619 } else { 1620 // Add the MemBarStoreStore after the InitializeNode so that 1621 // all stores performing the initialization that were moved 1622 // before the InitializeNode happen before the storestore 1623 // barrier. 1624 1625 Node* init_ctrl = init->proj_out_or_null(TypeFunc::Control); 1626 Node* init_mem = init->proj_out_or_null(TypeFunc::Memory); 1627 1628 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot); 1629 transform_later(mb); 1630 1631 Node* ctrl = new ProjNode(init, TypeFunc::Control); 1632 transform_later(ctrl); 1633 Node* mem = new ProjNode(init, TypeFunc::Memory); 1634 transform_later(mem); 1635 1636 // The MemBarStoreStore depends on control and memory coming 1637 // from the InitializeNode 1638 mb->init_req(TypeFunc::Memory, mem); 1639 mb->init_req(TypeFunc::Control, ctrl); 1640 1641 ctrl = new ProjNode(mb, TypeFunc::Control); 1642 transform_later(ctrl); 1643 mem = new ProjNode(mb, TypeFunc::Memory); 1644 transform_later(mem); 1645 1646 // All nodes that depended on the InitializeNode for control 1647 // and memory must now depend on the MemBarNode that itself 1648 // depends on the InitializeNode 1649 if (init_ctrl != nullptr) { 1650 _igvn.replace_node(init_ctrl, ctrl); 1651 } 1652 if (init_mem != nullptr) { 1653 _igvn.replace_node(init_mem, mem); 1654 } 1655 } 1656 } 1657 } 1658 1659 void PhaseMacroExpand::expand_dtrace_alloc_probe(AllocateNode* alloc, Node* oop, 1660 Node*& ctrl, Node*& rawmem) { 1661 if (C->env()->dtrace_alloc_probes()) { 1662 // Slow-path call 1663 int size = TypeFunc::Parms + 2; 1664 CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(), 1665 CAST_FROM_FN_PTR(address, 1666 static_cast<int (*)(JavaThread*, oopDesc*)>(SharedRuntime::dtrace_object_alloc)), 1667 "dtrace_object_alloc", 1668 TypeRawPtr::BOTTOM); 1669 1670 // Get base of thread-local storage area 1671 Node* thread = new ThreadLocalNode(); 1672 transform_later(thread); 1673 1674 call->init_req(TypeFunc::Parms + 0, thread); 1675 call->init_req(TypeFunc::Parms + 1, oop); 1676 call->init_req(TypeFunc::Control, ctrl); 1677 call->init_req(TypeFunc::I_O , top()); // does no i/o 1678 call->init_req(TypeFunc::Memory , rawmem); 1679 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr)); 1680 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr)); 1681 transform_later(call); 1682 ctrl = new ProjNode(call, TypeFunc::Control); 1683 transform_later(ctrl); 1684 rawmem = new ProjNode(call, TypeFunc::Memory); 1685 transform_later(rawmem); 1686 } 1687 } 1688 1689 // Helper for PhaseMacroExpand::expand_allocate_common. 1690 // Initializes the newly-allocated storage. 1691 Node* 1692 PhaseMacroExpand::initialize_object(AllocateNode* alloc, 1693 Node* control, Node* rawmem, Node* object, 1694 Node* klass_node, Node* length, 1695 Node* size_in_bytes) { 1696 InitializeNode* init = alloc->initialization(); 1697 // Store the klass & mark bits 1698 Node* mark_node = alloc->make_ideal_mark(&_igvn, object, control, rawmem); 1699 if (!mark_node->is_Con()) { 1700 transform_later(mark_node); 1701 } 1702 rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, TypeX_X->basic_type()); 1703 1704 if (!UseCompactObjectHeaders) { 1705 rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA); 1706 } 1707 1708 int header_size = alloc->minimum_header_size(); // conservatively small 1709 1710 // Array length 1711 if (length != nullptr) { // Arrays need length field 1712 rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT); 1713 // conservatively small header size: 1714 header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE); 1715 if (_igvn.type(klass_node)->isa_aryklassptr()) { // we know the exact header size in most cases: 1716 BasicType elem = _igvn.type(klass_node)->is_klassptr()->as_instance_type()->isa_aryptr()->elem()->array_element_basic_type(); 1717 if (is_reference_type(elem, true)) { 1718 elem = T_OBJECT; 1719 } 1720 header_size = Klass::layout_helper_header_size(Klass::array_layout_helper(elem)); 1721 } 1722 } 1723 1724 // Clear the object body, if necessary. 1725 if (init == nullptr) { 1726 // The init has somehow disappeared; be cautious and clear everything. 1727 // 1728 // This can happen if a node is allocated but an uncommon trap occurs 1729 // immediately. In this case, the Initialize gets associated with the 1730 // trap, and may be placed in a different (outer) loop, if the Allocate 1731 // is in a loop. If (this is rare) the inner loop gets unrolled, then 1732 // there can be two Allocates to one Initialize. The answer in all these 1733 // edge cases is safety first. It is always safe to clear immediately 1734 // within an Allocate, and then (maybe or maybe not) clear some more later. 1735 if (!(UseTLAB && ZeroTLAB)) { 1736 rawmem = ClearArrayNode::clear_memory(control, rawmem, object, 1737 header_size, size_in_bytes, 1738 &_igvn); 1739 } 1740 } else { 1741 if (!init->is_complete()) { 1742 // Try to win by zeroing only what the init does not store. 1743 // We can also try to do some peephole optimizations, 1744 // such as combining some adjacent subword stores. 1745 rawmem = init->complete_stores(control, rawmem, object, 1746 header_size, size_in_bytes, &_igvn); 1747 } 1748 // We have no more use for this link, since the AllocateNode goes away: 1749 init->set_req(InitializeNode::RawAddress, top()); 1750 // (If we keep the link, it just confuses the register allocator, 1751 // who thinks he sees a real use of the address by the membar.) 1752 } 1753 1754 return rawmem; 1755 } 1756 1757 // Generate prefetch instructions for next allocations. 1758 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false, 1759 Node*& contended_phi_rawmem, 1760 Node* old_eden_top, Node* new_eden_top, 1761 intx lines) { 1762 enum { fall_in_path = 1, pf_path = 2 }; 1763 if( UseTLAB && AllocatePrefetchStyle == 2 ) { 1764 // Generate prefetch allocation with watermark check. 1765 // As an allocation hits the watermark, we will prefetch starting 1766 // at a "distance" away from watermark. 1767 1768 Node *pf_region = new RegionNode(3); 1769 Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY, 1770 TypeRawPtr::BOTTOM ); 1771 // I/O is used for Prefetch 1772 Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO ); 1773 1774 Node *thread = new ThreadLocalNode(); 1775 transform_later(thread); 1776 1777 Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread, 1778 _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) ); 1779 transform_later(eden_pf_adr); 1780 1781 Node *old_pf_wm = new LoadPNode(needgc_false, 1782 contended_phi_rawmem, eden_pf_adr, 1783 TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, 1784 MemNode::unordered); 1785 transform_later(old_pf_wm); 1786 1787 // check against new_eden_top 1788 Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm ); 1789 transform_later(need_pf_cmp); 1790 Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge ); 1791 transform_later(need_pf_bol); 1792 IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol, 1793 PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN ); 1794 transform_later(need_pf_iff); 1795 1796 // true node, add prefetchdistance 1797 Node *need_pf_true = new IfTrueNode( need_pf_iff ); 1798 transform_later(need_pf_true); 1799 1800 Node *need_pf_false = new IfFalseNode( need_pf_iff ); 1801 transform_later(need_pf_false); 1802 1803 Node *new_pf_wmt = new AddPNode( top(), old_pf_wm, 1804 _igvn.MakeConX(AllocatePrefetchDistance) ); 1805 transform_later(new_pf_wmt ); 1806 new_pf_wmt->set_req(0, need_pf_true); 1807 1808 Node *store_new_wmt = new StorePNode(need_pf_true, 1809 contended_phi_rawmem, eden_pf_adr, 1810 TypeRawPtr::BOTTOM, new_pf_wmt, 1811 MemNode::unordered); 1812 transform_later(store_new_wmt); 1813 1814 // adding prefetches 1815 pf_phi_abio->init_req( fall_in_path, i_o ); 1816 1817 Node *prefetch_adr; 1818 Node *prefetch; 1819 uint step_size = AllocatePrefetchStepSize; 1820 uint distance = 0; 1821 1822 for ( intx i = 0; i < lines; i++ ) { 1823 prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt, 1824 _igvn.MakeConX(distance) ); 1825 transform_later(prefetch_adr); 1826 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr ); 1827 transform_later(prefetch); 1828 distance += step_size; 1829 i_o = prefetch; 1830 } 1831 pf_phi_abio->set_req( pf_path, i_o ); 1832 1833 pf_region->init_req( fall_in_path, need_pf_false ); 1834 pf_region->init_req( pf_path, need_pf_true ); 1835 1836 pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem ); 1837 pf_phi_rawmem->init_req( pf_path, store_new_wmt ); 1838 1839 transform_later(pf_region); 1840 transform_later(pf_phi_rawmem); 1841 transform_later(pf_phi_abio); 1842 1843 needgc_false = pf_region; 1844 contended_phi_rawmem = pf_phi_rawmem; 1845 i_o = pf_phi_abio; 1846 } else if( UseTLAB && AllocatePrefetchStyle == 3 ) { 1847 // Insert a prefetch instruction for each allocation. 1848 // This code is used to generate 1 prefetch instruction per cache line. 1849 1850 // Generate several prefetch instructions. 1851 uint step_size = AllocatePrefetchStepSize; 1852 uint distance = AllocatePrefetchDistance; 1853 1854 // Next cache address. 1855 Node *cache_adr = new AddPNode(old_eden_top, old_eden_top, 1856 _igvn.MakeConX(step_size + distance)); 1857 transform_later(cache_adr); 1858 cache_adr = new CastP2XNode(needgc_false, cache_adr); 1859 transform_later(cache_adr); 1860 // Address is aligned to execute prefetch to the beginning of cache line size 1861 // (it is important when BIS instruction is used on SPARC as prefetch). 1862 Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1)); 1863 cache_adr = new AndXNode(cache_adr, mask); 1864 transform_later(cache_adr); 1865 cache_adr = new CastX2PNode(cache_adr); 1866 transform_later(cache_adr); 1867 1868 // Prefetch 1869 Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr ); 1870 prefetch->set_req(0, needgc_false); 1871 transform_later(prefetch); 1872 contended_phi_rawmem = prefetch; 1873 Node *prefetch_adr; 1874 distance = step_size; 1875 for ( intx i = 1; i < lines; i++ ) { 1876 prefetch_adr = new AddPNode( cache_adr, cache_adr, 1877 _igvn.MakeConX(distance) ); 1878 transform_later(prefetch_adr); 1879 prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr ); 1880 transform_later(prefetch); 1881 distance += step_size; 1882 contended_phi_rawmem = prefetch; 1883 } 1884 } else if( AllocatePrefetchStyle > 0 ) { 1885 // Insert a prefetch for each allocation only on the fast-path 1886 Node *prefetch_adr; 1887 Node *prefetch; 1888 // Generate several prefetch instructions. 1889 uint step_size = AllocatePrefetchStepSize; 1890 uint distance = AllocatePrefetchDistance; 1891 for ( intx i = 0; i < lines; i++ ) { 1892 prefetch_adr = new AddPNode( old_eden_top, new_eden_top, 1893 _igvn.MakeConX(distance) ); 1894 transform_later(prefetch_adr); 1895 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr ); 1896 // Do not let it float too high, since if eden_top == eden_end, 1897 // both might be null. 1898 if( i == 0 ) { // Set control for first prefetch, next follows it 1899 prefetch->init_req(0, needgc_false); 1900 } 1901 transform_later(prefetch); 1902 distance += step_size; 1903 i_o = prefetch; 1904 } 1905 } 1906 return i_o; 1907 } 1908 1909 1910 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) { 1911 expand_allocate_common(alloc, nullptr, 1912 OptoRuntime::new_instance_Type(), 1913 OptoRuntime::new_instance_Java(), nullptr); 1914 } 1915 1916 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) { 1917 Node* length = alloc->in(AllocateNode::ALength); 1918 Node* valid_length_test = alloc->in(AllocateNode::ValidLengthTest); 1919 InitializeNode* init = alloc->initialization(); 1920 Node* klass_node = alloc->in(AllocateNode::KlassNode); 1921 const TypeAryKlassPtr* ary_klass_t = _igvn.type(klass_node)->isa_aryklassptr(); 1922 address slow_call_address; // Address of slow call 1923 if (init != nullptr && init->is_complete_with_arraycopy() && 1924 ary_klass_t && ary_klass_t->elem()->isa_klassptr() == nullptr) { 1925 // Don't zero type array during slow allocation in VM since 1926 // it will be initialized later by arraycopy in compiled code. 1927 slow_call_address = OptoRuntime::new_array_nozero_Java(); 1928 } else { 1929 slow_call_address = OptoRuntime::new_array_Java(); 1930 } 1931 expand_allocate_common(alloc, length, 1932 OptoRuntime::new_array_Type(), 1933 slow_call_address, valid_length_test); 1934 } 1935 1936 //-------------------mark_eliminated_box---------------------------------- 1937 // 1938 // During EA obj may point to several objects but after few ideal graph 1939 // transformations (CCP) it may point to only one non escaping object 1940 // (but still using phi), corresponding locks and unlocks will be marked 1941 // for elimination. Later obj could be replaced with a new node (new phi) 1942 // and which does not have escape information. And later after some graph 1943 // reshape other locks and unlocks (which were not marked for elimination 1944 // before) are connected to this new obj (phi) but they still will not be 1945 // marked for elimination since new obj has no escape information. 1946 // Mark all associated (same box and obj) lock and unlock nodes for 1947 // elimination if some of them marked already. 1948 void PhaseMacroExpand::mark_eliminated_box(Node* box, Node* obj) { 1949 BoxLockNode* oldbox = box->as_BoxLock(); 1950 if (oldbox->is_eliminated()) { 1951 return; // This BoxLock node was processed already. 1952 } 1953 assert(!oldbox->is_unbalanced(), "this should not be called for unbalanced region"); 1954 // New implementation (EliminateNestedLocks) has separate BoxLock 1955 // node for each locked region so mark all associated locks/unlocks as 1956 // eliminated even if different objects are referenced in one locked region 1957 // (for example, OSR compilation of nested loop inside locked scope). 1958 if (EliminateNestedLocks || 1959 oldbox->as_BoxLock()->is_simple_lock_region(nullptr, obj, nullptr)) { 1960 // Box is used only in one lock region. Mark this box as eliminated. 1961 oldbox->set_local(); // This verifies correct state of BoxLock 1962 _igvn.hash_delete(oldbox); 1963 oldbox->set_eliminated(); // This changes box's hash value 1964 _igvn.hash_insert(oldbox); 1965 1966 for (uint i = 0; i < oldbox->outcnt(); i++) { 1967 Node* u = oldbox->raw_out(i); 1968 if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) { 1969 AbstractLockNode* alock = u->as_AbstractLock(); 1970 // Check lock's box since box could be referenced by Lock's debug info. 1971 if (alock->box_node() == oldbox) { 1972 // Mark eliminated all related locks and unlocks. 1973 #ifdef ASSERT 1974 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc4"); 1975 #endif 1976 alock->set_non_esc_obj(); 1977 } 1978 } 1979 } 1980 return; 1981 } 1982 1983 // Create new "eliminated" BoxLock node and use it in monitor debug info 1984 // instead of oldbox for the same object. 1985 BoxLockNode* newbox = oldbox->clone()->as_BoxLock(); 1986 1987 // Note: BoxLock node is marked eliminated only here and it is used 1988 // to indicate that all associated lock and unlock nodes are marked 1989 // for elimination. 1990 newbox->set_local(); // This verifies correct state of BoxLock 1991 newbox->set_eliminated(); 1992 transform_later(newbox); 1993 1994 // Replace old box node with new box for all users of the same object. 1995 for (uint i = 0; i < oldbox->outcnt();) { 1996 bool next_edge = true; 1997 1998 Node* u = oldbox->raw_out(i); 1999 if (u->is_AbstractLock()) { 2000 AbstractLockNode* alock = u->as_AbstractLock(); 2001 if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) { 2002 // Replace Box and mark eliminated all related locks and unlocks. 2003 #ifdef ASSERT 2004 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc5"); 2005 #endif 2006 alock->set_non_esc_obj(); 2007 _igvn.rehash_node_delayed(alock); 2008 alock->set_box_node(newbox); 2009 next_edge = false; 2010 } 2011 } 2012 if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) { 2013 FastLockNode* flock = u->as_FastLock(); 2014 assert(flock->box_node() == oldbox, "sanity"); 2015 _igvn.rehash_node_delayed(flock); 2016 flock->set_box_node(newbox); 2017 next_edge = false; 2018 } 2019 2020 // Replace old box in monitor debug info. 2021 if (u->is_SafePoint() && u->as_SafePoint()->jvms()) { 2022 SafePointNode* sfn = u->as_SafePoint(); 2023 JVMState* youngest_jvms = sfn->jvms(); 2024 int max_depth = youngest_jvms->depth(); 2025 for (int depth = 1; depth <= max_depth; depth++) { 2026 JVMState* jvms = youngest_jvms->of_depth(depth); 2027 int num_mon = jvms->nof_monitors(); 2028 // Loop over monitors 2029 for (int idx = 0; idx < num_mon; idx++) { 2030 Node* obj_node = sfn->monitor_obj(jvms, idx); 2031 Node* box_node = sfn->monitor_box(jvms, idx); 2032 if (box_node == oldbox && obj_node->eqv_uncast(obj)) { 2033 int j = jvms->monitor_box_offset(idx); 2034 _igvn.replace_input_of(u, j, newbox); 2035 next_edge = false; 2036 } 2037 } 2038 } 2039 } 2040 if (next_edge) i++; 2041 } 2042 } 2043 2044 //-----------------------mark_eliminated_locking_nodes----------------------- 2045 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) { 2046 if (alock->box_node()->as_BoxLock()->is_unbalanced()) { 2047 return; // Can't do any more elimination for this locking region 2048 } 2049 if (EliminateNestedLocks) { 2050 if (alock->is_nested()) { 2051 assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity"); 2052 return; 2053 } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened 2054 // Only Lock node has JVMState needed here. 2055 // Not that preceding claim is documented anywhere else. 2056 if (alock->jvms() != nullptr) { 2057 if (alock->as_Lock()->is_nested_lock_region()) { 2058 // Mark eliminated related nested locks and unlocks. 2059 Node* obj = alock->obj_node(); 2060 BoxLockNode* box_node = alock->box_node()->as_BoxLock(); 2061 assert(!box_node->is_eliminated(), "should not be marked yet"); 2062 // Note: BoxLock node is marked eliminated only here 2063 // and it is used to indicate that all associated lock 2064 // and unlock nodes are marked for elimination. 2065 box_node->set_eliminated(); // Box's hash is always NO_HASH here 2066 for (uint i = 0; i < box_node->outcnt(); i++) { 2067 Node* u = box_node->raw_out(i); 2068 if (u->is_AbstractLock()) { 2069 alock = u->as_AbstractLock(); 2070 if (alock->box_node() == box_node) { 2071 // Verify that this Box is referenced only by related locks. 2072 assert(alock->obj_node()->eqv_uncast(obj), ""); 2073 // Mark all related locks and unlocks. 2074 #ifdef ASSERT 2075 alock->log_lock_optimization(C, "eliminate_lock_set_nested"); 2076 #endif 2077 alock->set_nested(); 2078 } 2079 } 2080 } 2081 } else { 2082 #ifdef ASSERT 2083 alock->log_lock_optimization(C, "eliminate_lock_NOT_nested_lock_region"); 2084 if (C->log() != nullptr) 2085 alock->as_Lock()->is_nested_lock_region(C); // rerun for debugging output 2086 #endif 2087 } 2088 } 2089 return; 2090 } 2091 // Process locks for non escaping object 2092 assert(alock->is_non_esc_obj(), ""); 2093 } // EliminateNestedLocks 2094 2095 if (alock->is_non_esc_obj()) { // Lock is used for non escaping object 2096 // Look for all locks of this object and mark them and 2097 // corresponding BoxLock nodes as eliminated. 2098 Node* obj = alock->obj_node(); 2099 for (uint j = 0; j < obj->outcnt(); j++) { 2100 Node* o = obj->raw_out(j); 2101 if (o->is_AbstractLock() && 2102 o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) { 2103 alock = o->as_AbstractLock(); 2104 Node* box = alock->box_node(); 2105 // Replace old box node with new eliminated box for all users 2106 // of the same object and mark related locks as eliminated. 2107 mark_eliminated_box(box, obj); 2108 } 2109 } 2110 } 2111 } 2112 2113 // we have determined that this lock/unlock can be eliminated, we simply 2114 // eliminate the node without expanding it. 2115 // 2116 // Note: The membar's associated with the lock/unlock are currently not 2117 // eliminated. This should be investigated as a future enhancement. 2118 // 2119 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) { 2120 2121 if (!alock->is_eliminated()) { 2122 return false; 2123 } 2124 #ifdef ASSERT 2125 if (!alock->is_coarsened()) { 2126 // Check that new "eliminated" BoxLock node is created. 2127 BoxLockNode* oldbox = alock->box_node()->as_BoxLock(); 2128 assert(oldbox->is_eliminated(), "should be done already"); 2129 } 2130 #endif 2131 2132 alock->log_lock_optimization(C, "eliminate_lock"); 2133 2134 #ifndef PRODUCT 2135 if (PrintEliminateLocks) { 2136 tty->print_cr("++++ Eliminated: %d %s '%s'", alock->_idx, (alock->is_Lock() ? "Lock" : "Unlock"), alock->kind_as_string()); 2137 } 2138 #endif 2139 2140 Node* mem = alock->in(TypeFunc::Memory); 2141 Node* ctrl = alock->in(TypeFunc::Control); 2142 guarantee(ctrl != nullptr, "missing control projection, cannot replace_node() with null"); 2143 2144 alock->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/); 2145 // There are 2 projections from the lock. The lock node will 2146 // be deleted when its last use is subsumed below. 2147 assert(alock->outcnt() == 2 && 2148 _callprojs.fallthrough_proj != nullptr && 2149 _callprojs.fallthrough_memproj != nullptr, 2150 "Unexpected projections from Lock/Unlock"); 2151 2152 Node* fallthroughproj = _callprojs.fallthrough_proj; 2153 Node* memproj_fallthrough = _callprojs.fallthrough_memproj; 2154 2155 // The memory projection from a lock/unlock is RawMem 2156 // The input to a Lock is merged memory, so extract its RawMem input 2157 // (unless the MergeMem has been optimized away.) 2158 if (alock->is_Lock()) { 2159 // Search for MemBarAcquireLock node and delete it also. 2160 MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar(); 2161 assert(membar != nullptr && membar->Opcode() == Op_MemBarAcquireLock, ""); 2162 Node* ctrlproj = membar->proj_out(TypeFunc::Control); 2163 Node* memproj = membar->proj_out(TypeFunc::Memory); 2164 _igvn.replace_node(ctrlproj, fallthroughproj); 2165 _igvn.replace_node(memproj, memproj_fallthrough); 2166 2167 // Delete FastLock node also if this Lock node is unique user 2168 // (a loop peeling may clone a Lock node). 2169 Node* flock = alock->as_Lock()->fastlock_node(); 2170 if (flock->outcnt() == 1) { 2171 assert(flock->unique_out() == alock, "sanity"); 2172 _igvn.replace_node(flock, top()); 2173 } 2174 } 2175 2176 // Search for MemBarReleaseLock node and delete it also. 2177 if (alock->is_Unlock() && ctrl->is_Proj() && ctrl->in(0)->is_MemBar()) { 2178 MemBarNode* membar = ctrl->in(0)->as_MemBar(); 2179 assert(membar->Opcode() == Op_MemBarReleaseLock && 2180 mem->is_Proj() && membar == mem->in(0), ""); 2181 _igvn.replace_node(fallthroughproj, ctrl); 2182 _igvn.replace_node(memproj_fallthrough, mem); 2183 fallthroughproj = ctrl; 2184 memproj_fallthrough = mem; 2185 ctrl = membar->in(TypeFunc::Control); 2186 mem = membar->in(TypeFunc::Memory); 2187 } 2188 2189 _igvn.replace_node(fallthroughproj, ctrl); 2190 _igvn.replace_node(memproj_fallthrough, mem); 2191 return true; 2192 } 2193 2194 2195 //------------------------------expand_lock_node---------------------- 2196 void PhaseMacroExpand::expand_lock_node(LockNode *lock) { 2197 2198 Node* ctrl = lock->in(TypeFunc::Control); 2199 Node* mem = lock->in(TypeFunc::Memory); 2200 Node* obj = lock->obj_node(); 2201 Node* box = lock->box_node(); 2202 Node* flock = lock->fastlock_node(); 2203 2204 assert(!box->as_BoxLock()->is_eliminated(), "sanity"); 2205 2206 // Make the merge point 2207 Node *region; 2208 Node *mem_phi; 2209 Node *slow_path; 2210 2211 region = new RegionNode(3); 2212 // create a Phi for the memory state 2213 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); 2214 2215 // Optimize test; set region slot 2 2216 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0); 2217 mem_phi->init_req(2, mem); 2218 2219 // Make slow path call 2220 CallNode *call = make_slow_call((CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), 2221 OptoRuntime::complete_monitor_locking_Java(), nullptr, slow_path, 2222 obj, box, nullptr); 2223 2224 call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/); 2225 2226 // Slow path can only throw asynchronous exceptions, which are always 2227 // de-opted. So the compiler thinks the slow-call can never throw an 2228 // exception. If it DOES throw an exception we would need the debug 2229 // info removed first (since if it throws there is no monitor). 2230 assert(_callprojs.fallthrough_ioproj == nullptr && _callprojs.catchall_ioproj == nullptr && 2231 _callprojs.catchall_memproj == nullptr && _callprojs.catchall_catchproj == nullptr, "Unexpected projection from Lock"); 2232 2233 // Capture slow path 2234 // disconnect fall-through projection from call and create a new one 2235 // hook up users of fall-through projection to region 2236 Node *slow_ctrl = _callprojs.fallthrough_proj->clone(); 2237 transform_later(slow_ctrl); 2238 _igvn.hash_delete(_callprojs.fallthrough_proj); 2239 _callprojs.fallthrough_proj->disconnect_inputs(C); 2240 region->init_req(1, slow_ctrl); 2241 // region inputs are now complete 2242 transform_later(region); 2243 _igvn.replace_node(_callprojs.fallthrough_proj, region); 2244 2245 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory)); 2246 2247 mem_phi->init_req(1, memproj); 2248 2249 transform_later(mem_phi); 2250 2251 _igvn.replace_node(_callprojs.fallthrough_memproj, mem_phi); 2252 } 2253 2254 //------------------------------expand_unlock_node---------------------- 2255 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) { 2256 2257 Node* ctrl = unlock->in(TypeFunc::Control); 2258 Node* mem = unlock->in(TypeFunc::Memory); 2259 Node* obj = unlock->obj_node(); 2260 Node* box = unlock->box_node(); 2261 2262 assert(!box->as_BoxLock()->is_eliminated(), "sanity"); 2263 2264 // No need for a null check on unlock 2265 2266 // Make the merge point 2267 Node *region; 2268 Node *mem_phi; 2269 2270 region = new RegionNode(3); 2271 // create a Phi for the memory state 2272 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); 2273 2274 FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box ); 2275 funlock = transform_later( funlock )->as_FastUnlock(); 2276 // Optimize test; set region slot 2 2277 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0); 2278 Node *thread = transform_later(new ThreadLocalNode()); 2279 2280 CallNode *call = make_slow_call((CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(), 2281 CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C), 2282 "complete_monitor_unlocking_C", slow_path, obj, box, thread); 2283 2284 call->extract_projections(&_callprojs, false /*separate_io_proj*/, false /*do_asserts*/); 2285 assert(_callprojs.fallthrough_ioproj == nullptr && _callprojs.catchall_ioproj == nullptr && 2286 _callprojs.catchall_memproj == nullptr && _callprojs.catchall_catchproj == nullptr, "Unexpected projection from Lock"); 2287 2288 // No exceptions for unlocking 2289 // Capture slow path 2290 // disconnect fall-through projection from call and create a new one 2291 // hook up users of fall-through projection to region 2292 Node *slow_ctrl = _callprojs.fallthrough_proj->clone(); 2293 transform_later(slow_ctrl); 2294 _igvn.hash_delete(_callprojs.fallthrough_proj); 2295 _callprojs.fallthrough_proj->disconnect_inputs(C); 2296 region->init_req(1, slow_ctrl); 2297 // region inputs are now complete 2298 transform_later(region); 2299 _igvn.replace_node(_callprojs.fallthrough_proj, region); 2300 2301 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) ); 2302 mem_phi->init_req(1, memproj ); 2303 mem_phi->init_req(2, mem); 2304 transform_later(mem_phi); 2305 2306 _igvn.replace_node(_callprojs.fallthrough_memproj, mem_phi); 2307 } 2308 2309 void PhaseMacroExpand::expand_subtypecheck_node(SubTypeCheckNode *check) { 2310 assert(check->in(SubTypeCheckNode::Control) == nullptr, "should be pinned"); 2311 Node* bol = check->unique_out(); 2312 Node* obj_or_subklass = check->in(SubTypeCheckNode::ObjOrSubKlass); 2313 Node* superklass = check->in(SubTypeCheckNode::SuperKlass); 2314 assert(bol->is_Bool() && bol->as_Bool()->_test._test == BoolTest::ne, "unexpected bool node"); 2315 2316 for (DUIterator_Last imin, i = bol->last_outs(imin); i >= imin; --i) { 2317 Node* iff = bol->last_out(i); 2318 assert(iff->is_If(), "where's the if?"); 2319 2320 if (iff->in(0)->is_top()) { 2321 _igvn.replace_input_of(iff, 1, C->top()); 2322 continue; 2323 } 2324 2325 Node* iftrue = iff->as_If()->proj_out(1); 2326 Node* iffalse = iff->as_If()->proj_out(0); 2327 Node* ctrl = iff->in(0); 2328 2329 Node* subklass = nullptr; 2330 if (_igvn.type(obj_or_subklass)->isa_klassptr()) { 2331 subklass = obj_or_subklass; 2332 } else { 2333 Node* k_adr = basic_plus_adr(obj_or_subklass, oopDesc::klass_offset_in_bytes()); 2334 subklass = _igvn.transform(LoadKlassNode::make(_igvn, nullptr, C->immutable_memory(), k_adr, TypeInstPtr::KLASS)); 2335 } 2336 2337 Node* not_subtype_ctrl = Phase::gen_subtype_check(subklass, superklass, &ctrl, nullptr, _igvn, check->method(), check->bci()); 2338 2339 _igvn.replace_input_of(iff, 0, C->top()); 2340 _igvn.replace_node(iftrue, not_subtype_ctrl); 2341 _igvn.replace_node(iffalse, ctrl); 2342 } 2343 _igvn.replace_node(check, C->top()); 2344 } 2345 2346 //---------------------------eliminate_macro_nodes---------------------- 2347 // Eliminate scalar replaced allocations and associated locks. 2348 void PhaseMacroExpand::eliminate_macro_nodes() { 2349 if (C->macro_count() == 0) 2350 return; 2351 NOT_PRODUCT(int membar_before = count_MemBar(C);) 2352 2353 // Before elimination may re-mark (change to Nested or NonEscObj) 2354 // all associated (same box and obj) lock and unlock nodes. 2355 int cnt = C->macro_count(); 2356 for (int i=0; i < cnt; i++) { 2357 Node *n = C->macro_node(i); 2358 if (n->is_AbstractLock()) { // Lock and Unlock nodes 2359 mark_eliminated_locking_nodes(n->as_AbstractLock()); 2360 } 2361 } 2362 // Re-marking may break consistency of Coarsened locks. 2363 if (!C->coarsened_locks_consistent()) { 2364 return; // recompile without Coarsened locks if broken 2365 } else { 2366 // After coarsened locks are eliminated locking regions 2367 // become unbalanced. We should not execute any more 2368 // locks elimination optimizations on them. 2369 C->mark_unbalanced_boxes(); 2370 } 2371 2372 // First, attempt to eliminate locks 2373 bool progress = true; 2374 while (progress) { 2375 progress = false; 2376 for (int i = C->macro_count(); i > 0; i = MIN2(i - 1, C->macro_count())) { // more than 1 element can be eliminated at once 2377 Node* n = C->macro_node(i - 1); 2378 bool success = false; 2379 DEBUG_ONLY(int old_macro_count = C->macro_count();) 2380 if (n->is_AbstractLock()) { 2381 success = eliminate_locking_node(n->as_AbstractLock()); 2382 #ifndef PRODUCT 2383 if (success && PrintOptoStatistics) { 2384 Atomic::inc(&PhaseMacroExpand::_monitor_objects_removed_counter); 2385 } 2386 #endif 2387 } 2388 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count"); 2389 progress = progress || success; 2390 } 2391 } 2392 // Next, attempt to eliminate allocations 2393 _has_locks = false; 2394 progress = true; 2395 while (progress) { 2396 progress = false; 2397 for (int i = C->macro_count(); i > 0; i = MIN2(i - 1, C->macro_count())) { // more than 1 element can be eliminated at once 2398 Node* n = C->macro_node(i - 1); 2399 bool success = false; 2400 DEBUG_ONLY(int old_macro_count = C->macro_count();) 2401 switch (n->class_id()) { 2402 case Node::Class_Allocate: 2403 case Node::Class_AllocateArray: 2404 success = eliminate_allocate_node(n->as_Allocate()); 2405 #ifndef PRODUCT 2406 if (success && PrintOptoStatistics) { 2407 Atomic::inc(&PhaseMacroExpand::_objs_scalar_replaced_counter); 2408 } 2409 #endif 2410 break; 2411 case Node::Class_CallStaticJava: 2412 success = eliminate_boxing_node(n->as_CallStaticJava()); 2413 break; 2414 case Node::Class_Lock: 2415 case Node::Class_Unlock: 2416 assert(!n->as_AbstractLock()->is_eliminated(), "sanity"); 2417 _has_locks = true; 2418 break; 2419 case Node::Class_ArrayCopy: 2420 break; 2421 case Node::Class_OuterStripMinedLoop: 2422 break; 2423 case Node::Class_SubTypeCheck: 2424 break; 2425 case Node::Class_Opaque1: 2426 break; 2427 default: 2428 assert(n->Opcode() == Op_LoopLimit || 2429 n->Opcode() == Op_Opaque3 || 2430 n->Opcode() == Op_Opaque4 || 2431 n->Opcode() == Op_MaxL || 2432 n->Opcode() == Op_MinL || 2433 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(n), 2434 "unknown node type in macro list"); 2435 } 2436 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count"); 2437 progress = progress || success; 2438 } 2439 } 2440 #ifndef PRODUCT 2441 if (PrintOptoStatistics) { 2442 int membar_after = count_MemBar(C); 2443 Atomic::add(&PhaseMacroExpand::_memory_barriers_removed_counter, membar_before - membar_after); 2444 } 2445 #endif 2446 } 2447 2448 //------------------------------expand_macro_nodes---------------------- 2449 // Returns true if a failure occurred. 2450 bool PhaseMacroExpand::expand_macro_nodes() { 2451 if (StressMacroExpansion) { 2452 C->shuffle_macro_nodes(); 2453 } 2454 // Last attempt to eliminate macro nodes. 2455 eliminate_macro_nodes(); 2456 if (C->failing()) return true; 2457 2458 // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations. 2459 bool progress = true; 2460 while (progress) { 2461 progress = false; 2462 for (int i = C->macro_count(); i > 0; i--) { 2463 Node* n = C->macro_node(i-1); 2464 bool success = false; 2465 DEBUG_ONLY(int old_macro_count = C->macro_count();) 2466 if (n->Opcode() == Op_LoopLimit) { 2467 // Remove it from macro list and put on IGVN worklist to optimize. 2468 C->remove_macro_node(n); 2469 _igvn._worklist.push(n); 2470 success = true; 2471 } else if (n->Opcode() == Op_CallStaticJava) { 2472 // Remove it from macro list and put on IGVN worklist to optimize. 2473 C->remove_macro_node(n); 2474 _igvn._worklist.push(n); 2475 success = true; 2476 } else if (n->is_Opaque1()) { 2477 _igvn.replace_node(n, n->in(1)); 2478 success = true; 2479 #if INCLUDE_RTM_OPT 2480 } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) { 2481 assert(C->profile_rtm(), "should be used only in rtm deoptimization code"); 2482 assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), ""); 2483 Node* cmp = n->unique_out(); 2484 #ifdef ASSERT 2485 // Validate graph. 2486 assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), ""); 2487 BoolNode* bol = cmp->unique_out()->as_Bool(); 2488 assert((bol->outcnt() == 1) && bol->unique_out()->is_If() && 2489 (bol->_test._test == BoolTest::ne), ""); 2490 IfNode* ifn = bol->unique_out()->as_If(); 2491 assert((ifn->outcnt() == 2) && 2492 ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change) != nullptr, ""); 2493 #endif 2494 Node* repl = n->in(1); 2495 if (!_has_locks) { 2496 // Remove RTM state check if there are no locks in the code. 2497 // Replace input to compare the same value. 2498 repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1); 2499 } 2500 _igvn.replace_node(n, repl); 2501 success = true; 2502 #endif 2503 } else if (n->Opcode() == Op_Opaque4) { 2504 // With Opaque4 nodes, the expectation is that the test of input 1 2505 // is always equal to the constant value of input 2. So we can 2506 // remove the Opaque4 and replace it by input 2. In debug builds, 2507 // leave the non constant test in instead to sanity check that it 2508 // never fails (if it does, that subgraph was constructed so, at 2509 // runtime, a Halt node is executed). 2510 #ifdef ASSERT 2511 _igvn.replace_node(n, n->in(1)); 2512 #else 2513 _igvn.replace_node(n, n->in(2)); 2514 #endif 2515 success = true; 2516 } else if (n->Opcode() == Op_OuterStripMinedLoop) { 2517 n->as_OuterStripMinedLoop()->adjust_strip_mined_loop(&_igvn); 2518 C->remove_macro_node(n); 2519 success = true; 2520 } else if (n->Opcode() == Op_MaxL) { 2521 // Since MaxL and MinL are not implemented in the backend, we expand them to 2522 // a CMoveL construct now. At least until here, the type could be computed 2523 // precisely. CMoveL is not so smart, but we can give it at least the best 2524 // type we know abouot n now. 2525 Node* repl = MaxNode::signed_max(n->in(1), n->in(2), _igvn.type(n), _igvn); 2526 _igvn.replace_node(n, repl); 2527 success = true; 2528 } else if (n->Opcode() == Op_MinL) { 2529 Node* repl = MaxNode::signed_min(n->in(1), n->in(2), _igvn.type(n), _igvn); 2530 _igvn.replace_node(n, repl); 2531 success = true; 2532 } 2533 assert(!success || (C->macro_count() == (old_macro_count - 1)), "elimination must have deleted one node from macro list"); 2534 progress = progress || success; 2535 if (success) { 2536 C->print_method(PHASE_AFTER_MACRO_EXPANSION_STEP, 5, n); 2537 } 2538 } 2539 } 2540 2541 // Clean up the graph so we're less likely to hit the maximum node 2542 // limit 2543 _igvn.set_delay_transform(false); 2544 _igvn.optimize(); 2545 if (C->failing()) return true; 2546 _igvn.set_delay_transform(true); 2547 2548 2549 // Because we run IGVN after each expansion, some macro nodes may go 2550 // dead and be removed from the list as we iterate over it. Move 2551 // Allocate nodes (processed in a second pass) at the beginning of 2552 // the list and then iterate from the last element of the list until 2553 // an Allocate node is seen. This is robust to random deletion in 2554 // the list due to nodes going dead. 2555 C->sort_macro_nodes(); 2556 2557 // expand arraycopy "macro" nodes first 2558 // For ReduceBulkZeroing, we must first process all arraycopy nodes 2559 // before the allocate nodes are expanded. 2560 while (C->macro_count() > 0) { 2561 int macro_count = C->macro_count(); 2562 Node * n = C->macro_node(macro_count-1); 2563 assert(n->is_macro(), "only macro nodes expected here"); 2564 if (_igvn.type(n) == Type::TOP || (n->in(0) != nullptr && n->in(0)->is_top())) { 2565 // node is unreachable, so don't try to expand it 2566 C->remove_macro_node(n); 2567 continue; 2568 } 2569 if (n->is_Allocate()) { 2570 break; 2571 } 2572 // Make sure expansion will not cause node limit to be exceeded. 2573 // Worst case is a macro node gets expanded into about 200 nodes. 2574 // Allow 50% more for optimization. 2575 if (C->check_node_count(300, "out of nodes before macro expansion")) { 2576 return true; 2577 } 2578 2579 DEBUG_ONLY(int old_macro_count = C->macro_count();) 2580 switch (n->class_id()) { 2581 case Node::Class_Lock: 2582 expand_lock_node(n->as_Lock()); 2583 break; 2584 case Node::Class_Unlock: 2585 expand_unlock_node(n->as_Unlock()); 2586 break; 2587 case Node::Class_ArrayCopy: 2588 expand_arraycopy_node(n->as_ArrayCopy()); 2589 break; 2590 case Node::Class_SubTypeCheck: 2591 expand_subtypecheck_node(n->as_SubTypeCheck()); 2592 break; 2593 default: 2594 assert(false, "unknown node type in macro list"); 2595 } 2596 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list"); 2597 if (C->failing()) return true; 2598 C->print_method(PHASE_AFTER_MACRO_EXPANSION_STEP, 5, n); 2599 2600 // Clean up the graph so we're less likely to hit the maximum node 2601 // limit 2602 _igvn.set_delay_transform(false); 2603 _igvn.optimize(); 2604 if (C->failing()) return true; 2605 _igvn.set_delay_transform(true); 2606 } 2607 2608 // All nodes except Allocate nodes are expanded now. There could be 2609 // new optimization opportunities (such as folding newly created 2610 // load from a just allocated object). Run IGVN. 2611 2612 // expand "macro" nodes 2613 // nodes are removed from the macro list as they are processed 2614 while (C->macro_count() > 0) { 2615 int macro_count = C->macro_count(); 2616 Node * n = C->macro_node(macro_count-1); 2617 assert(n->is_macro(), "only macro nodes expected here"); 2618 if (_igvn.type(n) == Type::TOP || (n->in(0) != nullptr && n->in(0)->is_top())) { 2619 // node is unreachable, so don't try to expand it 2620 C->remove_macro_node(n); 2621 continue; 2622 } 2623 // Make sure expansion will not cause node limit to be exceeded. 2624 // Worst case is a macro node gets expanded into about 200 nodes. 2625 // Allow 50% more for optimization. 2626 if (C->check_node_count(300, "out of nodes before macro expansion")) { 2627 return true; 2628 } 2629 switch (n->class_id()) { 2630 case Node::Class_Allocate: 2631 expand_allocate(n->as_Allocate()); 2632 break; 2633 case Node::Class_AllocateArray: 2634 expand_allocate_array(n->as_AllocateArray()); 2635 break; 2636 default: 2637 assert(false, "unknown node type in macro list"); 2638 } 2639 assert(C->macro_count() < macro_count, "must have deleted a node from macro list"); 2640 if (C->failing()) return true; 2641 C->print_method(PHASE_AFTER_MACRO_EXPANSION_STEP, 5, n); 2642 2643 // Clean up the graph so we're less likely to hit the maximum node 2644 // limit 2645 _igvn.set_delay_transform(false); 2646 _igvn.optimize(); 2647 if (C->failing()) return true; 2648 _igvn.set_delay_transform(true); 2649 } 2650 2651 _igvn.set_delay_transform(false); 2652 return false; 2653 } 2654 2655 #ifndef PRODUCT 2656 int PhaseMacroExpand::_objs_scalar_replaced_counter = 0; 2657 int PhaseMacroExpand::_monitor_objects_removed_counter = 0; 2658 int PhaseMacroExpand::_GC_barriers_removed_counter = 0; 2659 int PhaseMacroExpand::_memory_barriers_removed_counter = 0; 2660 2661 void PhaseMacroExpand::print_statistics() { 2662 tty->print("Objects scalar replaced = %d, ", Atomic::load(&_objs_scalar_replaced_counter)); 2663 tty->print("Monitor objects removed = %d, ", Atomic::load(&_monitor_objects_removed_counter)); 2664 tty->print("GC barriers removed = %d, ", Atomic::load(&_GC_barriers_removed_counter)); 2665 tty->print_cr("Memory barriers removed = %d", Atomic::load(&_memory_barriers_removed_counter)); 2666 } 2667 2668 int PhaseMacroExpand::count_MemBar(Compile *C) { 2669 if (!PrintOptoStatistics) { 2670 return 0; 2671 } 2672 Unique_Node_List ideal_nodes; 2673 int total = 0; 2674 ideal_nodes.map(C->live_nodes(), nullptr); 2675 ideal_nodes.push(C->root()); 2676 for (uint next = 0; next < ideal_nodes.size(); ++next) { 2677 Node* n = ideal_nodes.at(next); 2678 if (n->is_MemBar()) { 2679 total++; 2680 } 2681 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 2682 Node* m = n->fast_out(i); 2683 ideal_nodes.push(m); 2684 } 2685 } 2686 return total; 2687 } 2688 #endif