1 /* 2 * Copyright (c) 2005, 2019, 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 "libadt/vectset.hpp" 29 #include "memory/universe.hpp" 30 #include "opto/addnode.hpp" 31 #include "opto/arraycopynode.hpp" 32 #include "opto/callnode.hpp" 33 #include "opto/castnode.hpp" 34 #include "opto/cfgnode.hpp" 35 #include "opto/compile.hpp" 36 #include "opto/convertnode.hpp" 37 #include "opto/graphKit.hpp" 38 #include "opto/intrinsicnode.hpp" 39 #include "opto/locknode.hpp" 40 #include "opto/loopnode.hpp" 41 #include "opto/macro.hpp" 42 #include "opto/memnode.hpp" 43 #include "opto/narrowptrnode.hpp" 44 #include "opto/node.hpp" 45 #include "opto/opaquenode.hpp" 46 #include "opto/phaseX.hpp" 47 #include "opto/rootnode.hpp" 48 #include "opto/runtime.hpp" 49 #include "opto/subnode.hpp" 50 #include "opto/subtypenode.hpp" 51 #include "opto/type.hpp" 52 #include "runtime/sharedRuntime.hpp" 53 #include "utilities/macros.hpp" 54 #include "utilities/powerOfTwo.hpp" 55 #if INCLUDE_G1GC 56 #include "gc/g1/g1ThreadLocalData.hpp" 57 #endif // INCLUDE_G1GC 58 #if INCLUDE_SHENANDOAHGC 59 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp" 60 #endif 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 == NULL) { 79 break; 80 } 81 } 82 return nreplacements; 83 } 84 85 void PhaseMacroExpand::migrate_outs(Node *old, Node *target) { 86 assert(old != NULL, "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 void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) { 98 // Copy debug information and adjust JVMState information 99 uint old_dbg_start = oldcall->tf()->domain()->cnt(); 100 uint new_dbg_start = newcall->tf()->domain()->cnt(); 101 int jvms_adj = new_dbg_start - old_dbg_start; 102 assert (new_dbg_start == newcall->req(), "argument count mismatch"); 103 104 // SafePointScalarObject node could be referenced several times in debug info. 105 // Use Dict to record cloned nodes. 106 Dict* sosn_map = new Dict(cmpkey,hashkey); 107 for (uint i = old_dbg_start; i < oldcall->req(); i++) { 108 Node* old_in = oldcall->in(i); 109 // Clone old SafePointScalarObjectNodes, adjusting their field contents. 110 if (old_in != NULL && old_in->is_SafePointScalarObject()) { 111 SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject(); 112 uint old_unique = C->unique(); 113 Node* new_in = old_sosn->clone(sosn_map); 114 if (old_unique != C->unique()) { // New node? 115 new_in->set_req(0, C->root()); // reset control edge 116 new_in = transform_later(new_in); // Register new node. 117 } 118 old_in = new_in; 119 } 120 newcall->add_req(old_in); 121 } 122 123 // JVMS may be shared so clone it before we modify it 124 newcall->set_jvms(oldcall->jvms() != NULL ? oldcall->jvms()->clone_deep(C) : NULL); 125 for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) { 126 jvms->set_map(newcall); 127 jvms->set_locoff(jvms->locoff()+jvms_adj); 128 jvms->set_stkoff(jvms->stkoff()+jvms_adj); 129 jvms->set_monoff(jvms->monoff()+jvms_adj); 130 jvms->set_scloff(jvms->scloff()+jvms_adj); 131 jvms->set_endoff(jvms->endoff()+jvms_adj); 132 } 133 } 134 135 Node* PhaseMacroExpand::opt_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) { 136 Node* cmp; 137 if (mask != 0) { 138 Node* and_node = transform_later(new AndXNode(word, MakeConX(mask))); 139 cmp = transform_later(new CmpXNode(and_node, MakeConX(bits))); 140 } else { 141 cmp = word; 142 } 143 Node* bol = transform_later(new BoolNode(cmp, BoolTest::ne)); 144 IfNode* iff = new IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN ); 145 transform_later(iff); 146 147 // Fast path taken. 148 Node *fast_taken = transform_later(new IfFalseNode(iff)); 149 150 // Fast path not-taken, i.e. slow path 151 Node *slow_taken = transform_later(new IfTrueNode(iff)); 152 153 if (return_fast_path) { 154 region->init_req(edge, slow_taken); // Capture slow-control 155 return fast_taken; 156 } else { 157 region->init_req(edge, fast_taken); // Capture fast-control 158 return slow_taken; 159 } 160 } 161 162 //--------------------copy_predefined_input_for_runtime_call-------------------- 163 void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) { 164 // Set fixed predefined input arguments 165 call->init_req( TypeFunc::Control, ctrl ); 166 call->init_req( TypeFunc::I_O , oldcall->in( TypeFunc::I_O) ); 167 call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ????? 168 call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) ); 169 call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) ); 170 } 171 172 //------------------------------make_slow_call--------------------------------- 173 CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type, 174 address slow_call, const char* leaf_name, Node* slow_path, 175 Node* parm0, Node* parm1, Node* parm2) { 176 177 // Slow-path call 178 CallNode *call = leaf_name 179 ? (CallNode*)new CallLeafNode ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM ) 180 : (CallNode*)new CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM ); 181 182 // Slow path call has no side-effects, uses few values 183 copy_predefined_input_for_runtime_call(slow_path, oldcall, call ); 184 if (parm0 != NULL) call->init_req(TypeFunc::Parms+0, parm0); 185 if (parm1 != NULL) call->init_req(TypeFunc::Parms+1, parm1); 186 if (parm2 != NULL) call->init_req(TypeFunc::Parms+2, parm2); 187 copy_call_debug_info(oldcall, call); 188 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON. 189 _igvn.replace_node(oldcall, call); 190 transform_later(call); 191 192 return call; 193 } 194 195 void PhaseMacroExpand::extract_call_projections(CallNode *call) { 196 _fallthroughproj = NULL; 197 _fallthroughcatchproj = NULL; 198 _ioproj_fallthrough = NULL; 199 _ioproj_catchall = NULL; 200 _catchallcatchproj = NULL; 201 _memproj_fallthrough = NULL; 202 _memproj_catchall = NULL; 203 _resproj = NULL; 204 for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) { 205 ProjNode *pn = call->fast_out(i)->as_Proj(); 206 switch (pn->_con) { 207 case TypeFunc::Control: 208 { 209 // For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj 210 _fallthroughproj = pn; 211 DUIterator_Fast jmax, j = pn->fast_outs(jmax); 212 const Node *cn = pn->fast_out(j); 213 if (cn->is_Catch()) { 214 ProjNode *cpn = NULL; 215 for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) { 216 cpn = cn->fast_out(k)->as_Proj(); 217 assert(cpn->is_CatchProj(), "must be a CatchProjNode"); 218 if (cpn->_con == CatchProjNode::fall_through_index) 219 _fallthroughcatchproj = cpn; 220 else { 221 assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index."); 222 _catchallcatchproj = cpn; 223 } 224 } 225 } 226 break; 227 } 228 case TypeFunc::I_O: 229 if (pn->_is_io_use) 230 _ioproj_catchall = pn; 231 else 232 _ioproj_fallthrough = pn; 233 break; 234 case TypeFunc::Memory: 235 if (pn->_is_io_use) 236 _memproj_catchall = pn; 237 else 238 _memproj_fallthrough = pn; 239 break; 240 case TypeFunc::Parms: 241 _resproj = pn; 242 break; 243 default: 244 assert(false, "unexpected projection from allocation node."); 245 } 246 } 247 248 } 249 250 void PhaseMacroExpand::eliminate_gc_barrier(Node* p2x) { 251 BarrierSetC2 *bs = BarrierSet::barrier_set()->barrier_set_c2(); 252 bs->eliminate_gc_barrier(this, p2x); 253 } 254 255 // Search for a memory operation for the specified memory slice. 256 static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc, PhaseGVN *phase) { 257 Node *orig_mem = mem; 258 Node *alloc_mem = alloc->in(TypeFunc::Memory); 259 const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr(); 260 while (true) { 261 if (mem == alloc_mem || mem == start_mem ) { 262 return mem; // hit one of our sentinels 263 } else if (mem->is_MergeMem()) { 264 mem = mem->as_MergeMem()->memory_at(alias_idx); 265 } else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) { 266 Node *in = mem->in(0); 267 // we can safely skip over safepoints, calls, locks and membars because we 268 // already know that the object is safe to eliminate. 269 if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) { 270 return in; 271 } else if (in->is_Call()) { 272 CallNode *call = in->as_Call(); 273 if (call->may_modify(tinst, phase)) { 274 assert(call->is_ArrayCopy(), "ArrayCopy is the only call node that doesn't make allocation escape"); 275 if (call->as_ArrayCopy()->modifies(offset, offset, phase, false)) { 276 return in; 277 } 278 } 279 mem = in->in(TypeFunc::Memory); 280 } else if (in->is_MemBar()) { 281 ArrayCopyNode* ac = NULL; 282 if (ArrayCopyNode::may_modify(tinst, in->as_MemBar(), phase, ac)) { 283 assert(ac != NULL && ac->is_clonebasic(), "Only basic clone is a non escaping clone"); 284 return ac; 285 } 286 mem = in->in(TypeFunc::Memory); 287 } else { 288 assert(false, "unexpected projection"); 289 } 290 } else if (mem->is_Store()) { 291 const TypePtr* atype = mem->as_Store()->adr_type(); 292 int adr_idx = phase->C->get_alias_index(atype); 293 if (adr_idx == alias_idx) { 294 assert(atype->isa_oopptr(), "address type must be oopptr"); 295 int adr_offset = atype->offset(); 296 uint adr_iid = atype->is_oopptr()->instance_id(); 297 // Array elements references have the same alias_idx 298 // but different offset and different instance_id. 299 if (adr_offset == offset && adr_iid == alloc->_idx) 300 return mem; 301 } else { 302 assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw"); 303 } 304 mem = mem->in(MemNode::Memory); 305 } else if (mem->is_ClearArray()) { 306 if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) { 307 // Can not bypass initialization of the instance 308 // we are looking. 309 debug_only(intptr_t offset;) 310 assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity"); 311 InitializeNode* init = alloc->as_Allocate()->initialization(); 312 // We are looking for stored value, return Initialize node 313 // or memory edge from Allocate node. 314 if (init != NULL) 315 return init; 316 else 317 return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers). 318 } 319 // Otherwise skip it (the call updated 'mem' value). 320 } else if (mem->Opcode() == Op_SCMemProj) { 321 mem = mem->in(0); 322 Node* adr = NULL; 323 if (mem->is_LoadStore()) { 324 adr = mem->in(MemNode::Address); 325 } else { 326 assert(mem->Opcode() == Op_EncodeISOArray || 327 mem->Opcode() == Op_StrCompressedCopy, "sanity"); 328 adr = mem->in(3); // Destination array 329 } 330 const TypePtr* atype = adr->bottom_type()->is_ptr(); 331 int adr_idx = phase->C->get_alias_index(atype); 332 if (adr_idx == alias_idx) { 333 DEBUG_ONLY(mem->dump();) 334 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field"); 335 return NULL; 336 } 337 mem = mem->in(MemNode::Memory); 338 } else if (mem->Opcode() == Op_StrInflatedCopy) { 339 Node* adr = mem->in(3); // Destination array 340 const TypePtr* atype = adr->bottom_type()->is_ptr(); 341 int adr_idx = phase->C->get_alias_index(atype); 342 if (adr_idx == alias_idx) { 343 DEBUG_ONLY(mem->dump();) 344 assert(false, "Object is not scalar replaceable if a StrInflatedCopy node accesses its field"); 345 return NULL; 346 } 347 mem = mem->in(MemNode::Memory); 348 } else { 349 return mem; 350 } 351 assert(mem != orig_mem, "dead memory loop"); 352 } 353 } 354 355 // Generate loads from source of the arraycopy for fields of 356 // destination needed at a deoptimization point 357 Node* PhaseMacroExpand::make_arraycopy_load(ArrayCopyNode* ac, intptr_t offset, Node* ctl, Node* mem, BasicType ft, const Type *ftype, AllocateNode *alloc) { 358 BasicType bt = ft; 359 const Type *type = ftype; 360 if (ft == T_NARROWOOP) { 361 bt = T_OBJECT; 362 type = ftype->make_oopptr(); 363 } 364 Node* res = NULL; 365 if (ac->is_clonebasic()) { 366 assert(ac->in(ArrayCopyNode::Src) != ac->in(ArrayCopyNode::Dest), "clone source equals destination"); 367 Node* base = ac->in(ArrayCopyNode::Src); 368 Node* adr = _igvn.transform(new AddPNode(base, base, MakeConX(offset))); 369 const TypePtr* adr_type = _igvn.type(base)->is_ptr()->add_offset(offset); 370 res = LoadNode::make(_igvn, ctl, mem, adr, adr_type, type, bt, MemNode::unordered, LoadNode::UnknownControl); 371 } else { 372 if (ac->modifies(offset, offset, &_igvn, true)) { 373 assert(ac->in(ArrayCopyNode::Dest) == alloc->result_cast(), "arraycopy destination should be allocation's result"); 374 uint shift = exact_log2(type2aelembytes(bt)); 375 Node* src_pos = ac->in(ArrayCopyNode::SrcPos); 376 Node* dest_pos = ac->in(ArrayCopyNode::DestPos); 377 const TypeInt* src_pos_t = _igvn.type(src_pos)->is_int(); 378 const TypeInt* dest_pos_t = _igvn.type(dest_pos)->is_int(); 379 380 Node* adr = NULL; 381 const TypePtr* adr_type = NULL; 382 if (src_pos_t->is_con() && dest_pos_t->is_con()) { 383 intptr_t off = ((src_pos_t->get_con() - dest_pos_t->get_con()) << shift) + offset; 384 Node* base = ac->in(ArrayCopyNode::Src); 385 adr = _igvn.transform(new AddPNode(base, base, MakeConX(off))); 386 adr_type = _igvn.type(base)->is_ptr()->add_offset(off); 387 if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) { 388 // Don't emit a new load from src if src == dst but try to get the value from memory instead 389 return value_from_mem(ac->in(TypeFunc::Memory), ctl, ft, ftype, adr_type->isa_oopptr(), alloc); 390 } 391 } else { 392 Node* diff = _igvn.transform(new SubINode(ac->in(ArrayCopyNode::SrcPos), ac->in(ArrayCopyNode::DestPos))); 393 #ifdef _LP64 394 diff = _igvn.transform(new ConvI2LNode(diff)); 395 #endif 396 diff = _igvn.transform(new LShiftXNode(diff, intcon(shift))); 397 398 Node* off = _igvn.transform(new AddXNode(MakeConX(offset), diff)); 399 Node* base = ac->in(ArrayCopyNode::Src); 400 adr = _igvn.transform(new AddPNode(base, base, off)); 401 adr_type = _igvn.type(base)->is_ptr()->add_offset(Type::OffsetBot); 402 if (ac->in(ArrayCopyNode::Src) == ac->in(ArrayCopyNode::Dest)) { 403 // Non constant offset in the array: we can't statically 404 // determine the value 405 return NULL; 406 } 407 } 408 res = LoadNode::make(_igvn, ctl, mem, adr, adr_type, type, bt, MemNode::unordered, LoadNode::UnknownControl); 409 } 410 } 411 if (res != NULL) { 412 res = _igvn.transform(res); 413 if (ftype->isa_narrowoop()) { 414 // PhaseMacroExpand::scalar_replacement adds DecodeN nodes 415 res = _igvn.transform(new EncodePNode(res, ftype)); 416 } 417 return res; 418 } 419 return NULL; 420 } 421 422 // 423 // Given a Memory Phi, compute a value Phi containing the values from stores 424 // on the input paths. 425 // Note: this function is recursive, its depth is limited by the "level" argument 426 // Returns the computed Phi, or NULL if it cannot compute it. 427 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) { 428 assert(mem->is_Phi(), "sanity"); 429 int alias_idx = C->get_alias_index(adr_t); 430 int offset = adr_t->offset(); 431 int instance_id = adr_t->instance_id(); 432 433 // Check if an appropriate value phi already exists. 434 Node* region = mem->in(0); 435 for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) { 436 Node* phi = region->fast_out(k); 437 if (phi->is_Phi() && phi != mem && 438 phi->as_Phi()->is_same_inst_field(phi_type, (int)mem->_idx, instance_id, alias_idx, offset)) { 439 return phi; 440 } 441 } 442 // Check if an appropriate new value phi already exists. 443 Node* new_phi = value_phis->find(mem->_idx); 444 if (new_phi != NULL) 445 return new_phi; 446 447 if (level <= 0) { 448 return NULL; // Give up: phi tree too deep 449 } 450 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory); 451 Node *alloc_mem = alloc->in(TypeFunc::Memory); 452 453 uint length = mem->req(); 454 GrowableArray <Node *> values(length, length, NULL); 455 456 // create a new Phi for the value 457 PhiNode *phi = new PhiNode(mem->in(0), phi_type, NULL, mem->_idx, instance_id, alias_idx, offset); 458 transform_later(phi); 459 value_phis->push(phi, mem->_idx); 460 461 for (uint j = 1; j < length; j++) { 462 Node *in = mem->in(j); 463 if (in == NULL || in->is_top()) { 464 values.at_put(j, in); 465 } else { 466 Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc, &_igvn); 467 if (val == start_mem || val == alloc_mem) { 468 // hit a sentinel, return appropriate 0 value 469 values.at_put(j, _igvn.zerocon(ft)); 470 continue; 471 } 472 if (val->is_Initialize()) { 473 val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn); 474 } 475 if (val == NULL) { 476 return NULL; // can't find a value on this path 477 } 478 if (val == mem) { 479 values.at_put(j, mem); 480 } else if (val->is_Store()) { 481 Node* n = val->in(MemNode::ValueIn); 482 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); 483 n = bs->step_over_gc_barrier(n); 484 values.at_put(j, n); 485 } else if(val->is_Proj() && val->in(0) == alloc) { 486 values.at_put(j, _igvn.zerocon(ft)); 487 } else if (val->is_Phi()) { 488 val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1); 489 if (val == NULL) { 490 return NULL; 491 } 492 values.at_put(j, val); 493 } else if (val->Opcode() == Op_SCMemProj) { 494 assert(val->in(0)->is_LoadStore() || 495 val->in(0)->Opcode() == Op_EncodeISOArray || 496 val->in(0)->Opcode() == Op_StrCompressedCopy, "sanity"); 497 assert(false, "Object is not scalar replaceable if a LoadStore node accesses its field"); 498 return NULL; 499 } else if (val->is_ArrayCopy()) { 500 Node* res = make_arraycopy_load(val->as_ArrayCopy(), offset, val->in(0), val->in(TypeFunc::Memory), ft, phi_type, alloc); 501 if (res == NULL) { 502 return NULL; 503 } 504 values.at_put(j, res); 505 } else { 506 #ifdef ASSERT 507 val->dump(); 508 assert(false, "unknown node on this path"); 509 #endif 510 return NULL; // unknown node on this path 511 } 512 } 513 } 514 // Set Phi's inputs 515 for (uint j = 1; j < length; j++) { 516 if (values.at(j) == mem) { 517 phi->init_req(j, phi); 518 } else { 519 phi->init_req(j, values.at(j)); 520 } 521 } 522 return phi; 523 } 524 525 // Search the last value stored into the object's field. 526 Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, Node *sfpt_ctl, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, AllocateNode *alloc) { 527 assert(adr_t->is_known_instance_field(), "instance required"); 528 int instance_id = adr_t->instance_id(); 529 assert((uint)instance_id == alloc->_idx, "wrong allocation"); 530 531 int alias_idx = C->get_alias_index(adr_t); 532 int offset = adr_t->offset(); 533 Node *start_mem = C->start()->proj_out_or_null(TypeFunc::Memory); 534 Node *alloc_ctrl = alloc->in(TypeFunc::Control); 535 Node *alloc_mem = alloc->in(TypeFunc::Memory); 536 Arena *a = Thread::current()->resource_area(); 537 VectorSet visited(a); 538 539 bool done = sfpt_mem == alloc_mem; 540 Node *mem = sfpt_mem; 541 while (!done) { 542 if (visited.test_set(mem->_idx)) { 543 return NULL; // found a loop, give up 544 } 545 mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc, &_igvn); 546 if (mem == start_mem || mem == alloc_mem) { 547 done = true; // hit a sentinel, return appropriate 0 value 548 } else if (mem->is_Initialize()) { 549 mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn); 550 if (mem == NULL) { 551 done = true; // Something go wrong. 552 } else if (mem->is_Store()) { 553 const TypePtr* atype = mem->as_Store()->adr_type(); 554 assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice"); 555 done = true; 556 } 557 } else if (mem->is_Store()) { 558 const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr(); 559 assert(atype != NULL, "address type must be oopptr"); 560 assert(C->get_alias_index(atype) == alias_idx && 561 atype->is_known_instance_field() && atype->offset() == offset && 562 atype->instance_id() == instance_id, "store is correct memory slice"); 563 done = true; 564 } else if (mem->is_Phi()) { 565 // try to find a phi's unique input 566 Node *unique_input = NULL; 567 Node *top = C->top(); 568 for (uint i = 1; i < mem->req(); i++) { 569 Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc, &_igvn); 570 if (n == NULL || n == top || n == mem) { 571 continue; 572 } else if (unique_input == NULL) { 573 unique_input = n; 574 } else if (unique_input != n) { 575 unique_input = top; 576 break; 577 } 578 } 579 if (unique_input != NULL && unique_input != top) { 580 mem = unique_input; 581 } else { 582 done = true; 583 } 584 } else if (mem->is_ArrayCopy()) { 585 done = true; 586 } else { 587 assert(false, "unexpected node"); 588 } 589 } 590 if (mem != NULL) { 591 if (mem == start_mem || mem == alloc_mem) { 592 // hit a sentinel, return appropriate 0 value 593 return _igvn.zerocon(ft); 594 } else if (mem->is_Store()) { 595 Node* n = mem->in(MemNode::ValueIn); 596 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); 597 n = bs->step_over_gc_barrier(n); 598 return n; 599 } else if (mem->is_Phi()) { 600 // attempt to produce a Phi reflecting the values on the input paths of the Phi 601 Node_Stack value_phis(a, 8); 602 Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit); 603 if (phi != NULL) { 604 return phi; 605 } else { 606 // Kill all new Phis 607 while(value_phis.is_nonempty()) { 608 Node* n = value_phis.node(); 609 _igvn.replace_node(n, C->top()); 610 value_phis.pop(); 611 } 612 } 613 } else if (mem->is_ArrayCopy()) { 614 Node* ctl = mem->in(0); 615 Node* m = mem->in(TypeFunc::Memory); 616 if (sfpt_ctl->is_Proj() && sfpt_ctl->as_Proj()->is_uncommon_trap_proj(Deoptimization::Reason_none)) { 617 // pin the loads in the uncommon trap path 618 ctl = sfpt_ctl; 619 m = sfpt_mem; 620 } 621 return make_arraycopy_load(mem->as_ArrayCopy(), offset, ctl, m, ft, ftype, alloc); 622 } 623 } 624 // Something go wrong. 625 return NULL; 626 } 627 628 // Check the possibility of scalar replacement. 629 bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) { 630 // Scan the uses of the allocation to check for anything that would 631 // prevent us from eliminating it. 632 NOT_PRODUCT( const char* fail_eliminate = NULL; ) 633 DEBUG_ONLY( Node* disq_node = NULL; ) 634 bool can_eliminate = true; 635 636 Node* res = alloc->result_cast(); 637 const TypeOopPtr* res_type = NULL; 638 if (res == NULL) { 639 // All users were eliminated. 640 } else if (!res->is_CheckCastPP()) { 641 NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";) 642 can_eliminate = false; 643 } else { 644 res_type = _igvn.type(res)->isa_oopptr(); 645 if (res_type == NULL) { 646 NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";) 647 can_eliminate = false; 648 } else if (res_type->isa_aryptr()) { 649 int length = alloc->in(AllocateNode::ALength)->find_int_con(-1); 650 if (length < 0) { 651 NOT_PRODUCT(fail_eliminate = "Array's size is not constant";) 652 can_eliminate = false; 653 } 654 } 655 } 656 657 if (can_eliminate && res != NULL) { 658 for (DUIterator_Fast jmax, j = res->fast_outs(jmax); 659 j < jmax && can_eliminate; j++) { 660 Node* use = res->fast_out(j); 661 662 if (use->is_AddP()) { 663 const TypePtr* addp_type = _igvn.type(use)->is_ptr(); 664 int offset = addp_type->offset(); 665 666 if (offset == Type::OffsetTop || offset == Type::OffsetBot) { 667 NOT_PRODUCT(fail_eliminate = "Undefined field referrence";) 668 can_eliminate = false; 669 break; 670 } 671 for (DUIterator_Fast kmax, k = use->fast_outs(kmax); 672 k < kmax && can_eliminate; k++) { 673 Node* n = use->fast_out(k); 674 if (!n->is_Store() && n->Opcode() != Op_CastP2X 675 SHENANDOAHGC_ONLY(&& (!UseShenandoahGC || !ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(n))) ) { 676 DEBUG_ONLY(disq_node = n;) 677 if (n->is_Load() || n->is_LoadStore()) { 678 NOT_PRODUCT(fail_eliminate = "Field load";) 679 } else { 680 NOT_PRODUCT(fail_eliminate = "Not store field referrence";) 681 } 682 can_eliminate = false; 683 } 684 } 685 } else if (use->is_ArrayCopy() && 686 (use->as_ArrayCopy()->is_clonebasic() || 687 use->as_ArrayCopy()->is_arraycopy_validated() || 688 use->as_ArrayCopy()->is_copyof_validated() || 689 use->as_ArrayCopy()->is_copyofrange_validated()) && 690 use->in(ArrayCopyNode::Dest) == res) { 691 // ok to eliminate 692 } else if (use->is_SafePoint()) { 693 SafePointNode* sfpt = use->as_SafePoint(); 694 if (sfpt->is_Call() && sfpt->as_Call()->has_non_debug_use(res)) { 695 // Object is passed as argument. 696 DEBUG_ONLY(disq_node = use;) 697 NOT_PRODUCT(fail_eliminate = "Object is passed as argument";) 698 can_eliminate = false; 699 } 700 Node* sfptMem = sfpt->memory(); 701 if (sfptMem == NULL || sfptMem->is_top()) { 702 DEBUG_ONLY(disq_node = use;) 703 NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";) 704 can_eliminate = false; 705 } else { 706 safepoints.append_if_missing(sfpt); 707 } 708 } else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark 709 if (use->is_Phi()) { 710 if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) { 711 NOT_PRODUCT(fail_eliminate = "Object is return value";) 712 } else { 713 NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";) 714 } 715 DEBUG_ONLY(disq_node = use;) 716 } else { 717 if (use->Opcode() == Op_Return) { 718 NOT_PRODUCT(fail_eliminate = "Object is return value";) 719 }else { 720 NOT_PRODUCT(fail_eliminate = "Object is referenced by node";) 721 } 722 DEBUG_ONLY(disq_node = use;) 723 } 724 can_eliminate = false; 725 } 726 } 727 } 728 729 #ifndef PRODUCT 730 if (PrintEliminateAllocations) { 731 if (can_eliminate) { 732 tty->print("Scalar "); 733 if (res == NULL) 734 alloc->dump(); 735 else 736 res->dump(); 737 } else if (alloc->_is_scalar_replaceable) { 738 tty->print("NotScalar (%s)", fail_eliminate); 739 if (res == NULL) 740 alloc->dump(); 741 else 742 res->dump(); 743 #ifdef ASSERT 744 if (disq_node != NULL) { 745 tty->print(" >>>> "); 746 disq_node->dump(); 747 } 748 #endif /*ASSERT*/ 749 } 750 } 751 #endif 752 return can_eliminate; 753 } 754 755 // Do scalar replacement. 756 bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) { 757 GrowableArray <SafePointNode *> safepoints_done; 758 759 ciKlass* klass = NULL; 760 ciInstanceKlass* iklass = NULL; 761 int nfields = 0; 762 int array_base = 0; 763 int element_size = 0; 764 BasicType basic_elem_type = T_ILLEGAL; 765 ciType* elem_type = NULL; 766 767 Node* res = alloc->result_cast(); 768 assert(res == NULL || res->is_CheckCastPP(), "unexpected AllocateNode result"); 769 const TypeOopPtr* res_type = NULL; 770 if (res != NULL) { // Could be NULL when there are no users 771 res_type = _igvn.type(res)->isa_oopptr(); 772 } 773 774 if (res != NULL) { 775 klass = res_type->klass(); 776 if (res_type->isa_instptr()) { 777 // find the fields of the class which will be needed for safepoint debug information 778 assert(klass->is_instance_klass(), "must be an instance klass."); 779 iklass = klass->as_instance_klass(); 780 nfields = iklass->nof_nonstatic_fields(); 781 } else { 782 // find the array's elements which will be needed for safepoint debug information 783 nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1); 784 assert(klass->is_array_klass() && nfields >= 0, "must be an array klass."); 785 elem_type = klass->as_array_klass()->element_type(); 786 basic_elem_type = elem_type->basic_type(); 787 array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type); 788 element_size = type2aelembytes(basic_elem_type); 789 } 790 } 791 // 792 // Process the safepoint uses 793 // 794 while (safepoints.length() > 0) { 795 SafePointNode* sfpt = safepoints.pop(); 796 Node* mem = sfpt->memory(); 797 Node* ctl = sfpt->control(); 798 assert(sfpt->jvms() != NULL, "missed JVMS"); 799 // Fields of scalar objs are referenced only at the end 800 // of regular debuginfo at the last (youngest) JVMS. 801 // Record relative start index. 802 uint first_ind = (sfpt->req() - sfpt->jvms()->scloff()); 803 SafePointScalarObjectNode* sobj = new SafePointScalarObjectNode(res_type, 804 #ifdef ASSERT 805 alloc, 806 #endif 807 first_ind, nfields); 808 sobj->init_req(0, C->root()); 809 transform_later(sobj); 810 811 // Scan object's fields adding an input to the safepoint for each field. 812 for (int j = 0; j < nfields; j++) { 813 intptr_t offset; 814 ciField* field = NULL; 815 if (iklass != NULL) { 816 field = iklass->nonstatic_field_at(j); 817 offset = field->offset(); 818 elem_type = field->type(); 819 basic_elem_type = field->layout_type(); 820 } else { 821 offset = array_base + j * (intptr_t)element_size; 822 } 823 824 const Type *field_type; 825 // The next code is taken from Parse::do_get_xxx(). 826 if (is_reference_type(basic_elem_type)) { 827 if (!elem_type->is_loaded()) { 828 field_type = TypeInstPtr::BOTTOM; 829 } else if (field != NULL && field->is_static_constant()) { 830 // This can happen if the constant oop is non-perm. 831 ciObject* con = field->constant_value().as_object(); 832 // Do not "join" in the previous type; it doesn't add value, 833 // and may yield a vacuous result if the field is of interface type. 834 field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr(); 835 assert(field_type != NULL, "field singleton type must be consistent"); 836 } else { 837 field_type = TypeOopPtr::make_from_klass(elem_type->as_klass()); 838 } 839 if (UseCompressedOops) { 840 field_type = field_type->make_narrowoop(); 841 basic_elem_type = T_NARROWOOP; 842 } 843 } else { 844 field_type = Type::get_const_basic_type(basic_elem_type); 845 } 846 847 const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr(); 848 849 Node *field_val = value_from_mem(mem, ctl, basic_elem_type, field_type, field_addr_type, alloc); 850 if (field_val == NULL) { 851 // We weren't able to find a value for this field, 852 // give up on eliminating this allocation. 853 854 // Remove any extra entries we added to the safepoint. 855 uint last = sfpt->req() - 1; 856 for (int k = 0; k < j; k++) { 857 sfpt->del_req(last--); 858 } 859 _igvn._worklist.push(sfpt); 860 // rollback processed safepoints 861 while (safepoints_done.length() > 0) { 862 SafePointNode* sfpt_done = safepoints_done.pop(); 863 // remove any extra entries we added to the safepoint 864 last = sfpt_done->req() - 1; 865 for (int k = 0; k < nfields; k++) { 866 sfpt_done->del_req(last--); 867 } 868 JVMState *jvms = sfpt_done->jvms(); 869 jvms->set_endoff(sfpt_done->req()); 870 // Now make a pass over the debug information replacing any references 871 // to SafePointScalarObjectNode with the allocated object. 872 int start = jvms->debug_start(); 873 int end = jvms->debug_end(); 874 for (int i = start; i < end; i++) { 875 if (sfpt_done->in(i)->is_SafePointScalarObject()) { 876 SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject(); 877 if (scobj->first_index(jvms) == sfpt_done->req() && 878 scobj->n_fields() == (uint)nfields) { 879 assert(scobj->alloc() == alloc, "sanity"); 880 sfpt_done->set_req(i, res); 881 } 882 } 883 } 884 _igvn._worklist.push(sfpt_done); 885 } 886 #ifndef PRODUCT 887 if (PrintEliminateAllocations) { 888 if (field != NULL) { 889 tty->print("=== At SafePoint node %d can't find value of Field: ", 890 sfpt->_idx); 891 field->print(); 892 int field_idx = C->get_alias_index(field_addr_type); 893 tty->print(" (alias_idx=%d)", field_idx); 894 } else { // Array's element 895 tty->print("=== At SafePoint node %d can't find value of array element [%d]", 896 sfpt->_idx, j); 897 } 898 tty->print(", which prevents elimination of: "); 899 if (res == NULL) 900 alloc->dump(); 901 else 902 res->dump(); 903 } 904 #endif 905 return false; 906 } 907 if (UseCompressedOops && field_type->isa_narrowoop()) { 908 // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation 909 // to be able scalar replace the allocation. 910 if (field_val->is_EncodeP()) { 911 field_val = field_val->in(1); 912 } else { 913 field_val = transform_later(new DecodeNNode(field_val, field_val->get_ptr_type())); 914 } 915 } 916 sfpt->add_req(field_val); 917 } 918 JVMState *jvms = sfpt->jvms(); 919 jvms->set_endoff(sfpt->req()); 920 // Now make a pass over the debug information replacing any references 921 // to the allocated object with "sobj" 922 int start = jvms->debug_start(); 923 int end = jvms->debug_end(); 924 sfpt->replace_edges_in_range(res, sobj, start, end); 925 _igvn._worklist.push(sfpt); 926 safepoints_done.append_if_missing(sfpt); // keep it for rollback 927 } 928 return true; 929 } 930 931 static void disconnect_projections(MultiNode* n, PhaseIterGVN& igvn) { 932 Node* ctl_proj = n->proj_out_or_null(TypeFunc::Control); 933 Node* mem_proj = n->proj_out_or_null(TypeFunc::Memory); 934 if (ctl_proj != NULL) { 935 igvn.replace_node(ctl_proj, n->in(0)); 936 } 937 if (mem_proj != NULL) { 938 igvn.replace_node(mem_proj, n->in(TypeFunc::Memory)); 939 } 940 } 941 942 // Process users of eliminated allocation. 943 void PhaseMacroExpand::process_users_of_allocation(CallNode *alloc) { 944 Node* res = alloc->result_cast(); 945 if (res != NULL) { 946 for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) { 947 Node *use = res->last_out(j); 948 uint oc1 = res->outcnt(); 949 950 if (use->is_AddP()) { 951 for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) { 952 Node *n = use->last_out(k); 953 uint oc2 = use->outcnt(); 954 if (n->is_Store()) { 955 #ifdef ASSERT 956 // Verify that there is no dependent MemBarVolatile nodes, 957 // they should be removed during IGVN, see MemBarNode::Ideal(). 958 for (DUIterator_Fast pmax, p = n->fast_outs(pmax); 959 p < pmax; p++) { 960 Node* mb = n->fast_out(p); 961 assert(mb->is_Initialize() || !mb->is_MemBar() || 962 mb->req() <= MemBarNode::Precedent || 963 mb->in(MemBarNode::Precedent) != n, 964 "MemBarVolatile should be eliminated for non-escaping object"); 965 } 966 #endif 967 _igvn.replace_node(n, n->in(MemNode::Memory)); 968 } else { 969 eliminate_gc_barrier(n); 970 } 971 k -= (oc2 - use->outcnt()); 972 } 973 _igvn.remove_dead_node(use); 974 } else if (use->is_ArrayCopy()) { 975 // Disconnect ArrayCopy node 976 ArrayCopyNode* ac = use->as_ArrayCopy(); 977 if (ac->is_clonebasic()) { 978 Node* membar_after = ac->proj_out(TypeFunc::Control)->unique_ctrl_out(); 979 disconnect_projections(ac, _igvn); 980 assert(alloc->in(TypeFunc::Memory)->is_Proj() && alloc->in(TypeFunc::Memory)->in(0)->Opcode() == Op_MemBarCPUOrder, "mem barrier expected before allocation"); 981 Node* membar_before = alloc->in(TypeFunc::Memory)->in(0); 982 disconnect_projections(membar_before->as_MemBar(), _igvn); 983 if (membar_after->is_MemBar()) { 984 disconnect_projections(membar_after->as_MemBar(), _igvn); 985 } 986 } else { 987 assert(ac->is_arraycopy_validated() || 988 ac->is_copyof_validated() || 989 ac->is_copyofrange_validated(), "unsupported"); 990 CallProjections callprojs; 991 ac->extract_projections(&callprojs, true); 992 993 _igvn.replace_node(callprojs.fallthrough_ioproj, ac->in(TypeFunc::I_O)); 994 _igvn.replace_node(callprojs.fallthrough_memproj, ac->in(TypeFunc::Memory)); 995 _igvn.replace_node(callprojs.fallthrough_catchproj, ac->in(TypeFunc::Control)); 996 997 // Set control to top. IGVN will remove the remaining projections 998 ac->set_req(0, top()); 999 ac->replace_edge(res, top()); 1000 1001 // Disconnect src right away: it can help find new 1002 // opportunities for allocation elimination 1003 Node* src = ac->in(ArrayCopyNode::Src); 1004 ac->replace_edge(src, top()); 1005 // src can be top at this point if src and dest of the 1006 // arraycopy were the same 1007 if (src->outcnt() == 0 && !src->is_top()) { 1008 _igvn.remove_dead_node(src); 1009 } 1010 } 1011 _igvn._worklist.push(ac); 1012 } else { 1013 eliminate_gc_barrier(use); 1014 } 1015 j -= (oc1 - res->outcnt()); 1016 } 1017 assert(res->outcnt() == 0, "all uses of allocated objects must be deleted"); 1018 _igvn.remove_dead_node(res); 1019 } 1020 1021 // 1022 // Process other users of allocation's projections 1023 // 1024 if (_resproj != NULL && _resproj->outcnt() != 0) { 1025 // First disconnect stores captured by Initialize node. 1026 // If Initialize node is eliminated first in the following code, 1027 // it will kill such stores and DUIterator_Last will assert. 1028 for (DUIterator_Fast jmax, j = _resproj->fast_outs(jmax); j < jmax; j++) { 1029 Node *use = _resproj->fast_out(j); 1030 if (use->is_AddP()) { 1031 // raw memory addresses used only by the initialization 1032 _igvn.replace_node(use, C->top()); 1033 --j; --jmax; 1034 } 1035 } 1036 for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) { 1037 Node *use = _resproj->last_out(j); 1038 uint oc1 = _resproj->outcnt(); 1039 if (use->is_Initialize()) { 1040 // Eliminate Initialize node. 1041 InitializeNode *init = use->as_Initialize(); 1042 assert(init->outcnt() <= 2, "only a control and memory projection expected"); 1043 Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control); 1044 if (ctrl_proj != NULL) { 1045 _igvn.replace_node(ctrl_proj, init->in(TypeFunc::Control)); 1046 #ifdef ASSERT 1047 Node* tmp = init->in(TypeFunc::Control); 1048 assert(tmp == _fallthroughcatchproj, "allocation control projection"); 1049 #endif 1050 } 1051 Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory); 1052 if (mem_proj != NULL) { 1053 Node *mem = init->in(TypeFunc::Memory); 1054 #ifdef ASSERT 1055 if (mem->is_MergeMem()) { 1056 assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection"); 1057 } else { 1058 assert(mem == _memproj_fallthrough, "allocation memory projection"); 1059 } 1060 #endif 1061 _igvn.replace_node(mem_proj, mem); 1062 } 1063 } else { 1064 assert(false, "only Initialize or AddP expected"); 1065 } 1066 j -= (oc1 - _resproj->outcnt()); 1067 } 1068 } 1069 if (_fallthroughcatchproj != NULL) { 1070 _igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control)); 1071 } 1072 if (_memproj_fallthrough != NULL) { 1073 _igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory)); 1074 } 1075 if (_memproj_catchall != NULL) { 1076 _igvn.replace_node(_memproj_catchall, C->top()); 1077 } 1078 if (_ioproj_fallthrough != NULL) { 1079 _igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O)); 1080 } 1081 if (_ioproj_catchall != NULL) { 1082 _igvn.replace_node(_ioproj_catchall, C->top()); 1083 } 1084 if (_catchallcatchproj != NULL) { 1085 _igvn.replace_node(_catchallcatchproj, C->top()); 1086 } 1087 } 1088 1089 bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) { 1090 // Don't do scalar replacement if the frame can be popped by JVMTI: 1091 // if reallocation fails during deoptimization we'll pop all 1092 // interpreter frames for this compiled frame and that won't play 1093 // nice with JVMTI popframe. 1094 if (!EliminateAllocations || JvmtiExport::can_pop_frame() || !alloc->_is_non_escaping) { 1095 return false; 1096 } 1097 Node* klass = alloc->in(AllocateNode::KlassNode); 1098 const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr(); 1099 Node* res = alloc->result_cast(); 1100 // Eliminate boxing allocations which are not used 1101 // regardless scalar replacable status. 1102 bool boxing_alloc = C->eliminate_boxing() && 1103 tklass->klass()->is_instance_klass() && 1104 tklass->klass()->as_instance_klass()->is_box_klass(); 1105 if (!alloc->_is_scalar_replaceable && (!boxing_alloc || (res != NULL))) { 1106 return false; 1107 } 1108 1109 extract_call_projections(alloc); 1110 1111 GrowableArray <SafePointNode *> safepoints; 1112 if (!can_eliminate_allocation(alloc, safepoints)) { 1113 return false; 1114 } 1115 1116 if (!alloc->_is_scalar_replaceable) { 1117 assert(res == NULL, "sanity"); 1118 // We can only eliminate allocation if all debug info references 1119 // are already replaced with SafePointScalarObject because 1120 // we can't search for a fields value without instance_id. 1121 if (safepoints.length() > 0) { 1122 return false; 1123 } 1124 } 1125 1126 if (!scalar_replacement(alloc, safepoints)) { 1127 return false; 1128 } 1129 1130 CompileLog* log = C->log(); 1131 if (log != NULL) { 1132 log->head("eliminate_allocation type='%d'", 1133 log->identify(tklass->klass())); 1134 JVMState* p = alloc->jvms(); 1135 while (p != NULL) { 1136 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method())); 1137 p = p->caller(); 1138 } 1139 log->tail("eliminate_allocation"); 1140 } 1141 1142 process_users_of_allocation(alloc); 1143 1144 #ifndef PRODUCT 1145 if (PrintEliminateAllocations) { 1146 if (alloc->is_AllocateArray()) 1147 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx); 1148 else 1149 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx); 1150 } 1151 #endif 1152 1153 return true; 1154 } 1155 1156 bool PhaseMacroExpand::eliminate_boxing_node(CallStaticJavaNode *boxing) { 1157 // EA should remove all uses of non-escaping boxing node. 1158 if (!C->eliminate_boxing() || boxing->proj_out_or_null(TypeFunc::Parms) != NULL) { 1159 return false; 1160 } 1161 1162 assert(boxing->result_cast() == NULL, "unexpected boxing node result"); 1163 1164 extract_call_projections(boxing); 1165 1166 const TypeTuple* r = boxing->tf()->range(); 1167 assert(r->cnt() > TypeFunc::Parms, "sanity"); 1168 const TypeInstPtr* t = r->field_at(TypeFunc::Parms)->isa_instptr(); 1169 assert(t != NULL, "sanity"); 1170 1171 CompileLog* log = C->log(); 1172 if (log != NULL) { 1173 log->head("eliminate_boxing type='%d'", 1174 log->identify(t->klass())); 1175 JVMState* p = boxing->jvms(); 1176 while (p != NULL) { 1177 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method())); 1178 p = p->caller(); 1179 } 1180 log->tail("eliminate_boxing"); 1181 } 1182 1183 process_users_of_allocation(boxing); 1184 1185 #ifndef PRODUCT 1186 if (PrintEliminateAllocations) { 1187 tty->print("++++ Eliminated: %d ", boxing->_idx); 1188 boxing->method()->print_short_name(tty); 1189 tty->cr(); 1190 } 1191 #endif 1192 1193 return true; 1194 } 1195 1196 //---------------------------set_eden_pointers------------------------- 1197 void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) { 1198 if (UseTLAB) { // Private allocation: load from TLS 1199 Node* thread = transform_later(new ThreadLocalNode()); 1200 int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset()); 1201 int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset()); 1202 eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset); 1203 eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset); 1204 } else { // Shared allocation: load from globals 1205 CollectedHeap* ch = Universe::heap(); 1206 address top_adr = (address)ch->top_addr(); 1207 address end_adr = (address)ch->end_addr(); 1208 eden_top_adr = makecon(TypeRawPtr::make(top_adr)); 1209 eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr); 1210 } 1211 } 1212 1213 1214 Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) { 1215 Node* adr = basic_plus_adr(base, offset); 1216 const TypePtr* adr_type = adr->bottom_type()->is_ptr(); 1217 Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt, MemNode::unordered); 1218 transform_later(value); 1219 return value; 1220 } 1221 1222 1223 Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) { 1224 Node* adr = basic_plus_adr(base, offset); 1225 mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt, MemNode::unordered); 1226 transform_later(mem); 1227 return mem; 1228 } 1229 1230 //============================================================================= 1231 // 1232 // A L L O C A T I O N 1233 // 1234 // Allocation attempts to be fast in the case of frequent small objects. 1235 // It breaks down like this: 1236 // 1237 // 1) Size in doublewords is computed. This is a constant for objects and 1238 // variable for most arrays. Doubleword units are used to avoid size 1239 // overflow of huge doubleword arrays. We need doublewords in the end for 1240 // rounding. 1241 // 1242 // 2) Size is checked for being 'too large'. Too-large allocations will go 1243 // the slow path into the VM. The slow path can throw any required 1244 // exceptions, and does all the special checks for very large arrays. The 1245 // size test can constant-fold away for objects. For objects with 1246 // finalizers it constant-folds the otherway: you always go slow with 1247 // finalizers. 1248 // 1249 // 3) If NOT using TLABs, this is the contended loop-back point. 1250 // Load-Locked the heap top. If using TLABs normal-load the heap top. 1251 // 1252 // 4) Check that heap top + size*8 < max. If we fail go the slow ` route. 1253 // NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish 1254 // "size*8" we always enter the VM, where "largish" is a constant picked small 1255 // enough that there's always space between the eden max and 4Gig (old space is 1256 // there so it's quite large) and large enough that the cost of entering the VM 1257 // is dwarfed by the cost to initialize the space. 1258 // 1259 // 5) If NOT using TLABs, Store-Conditional the adjusted heap top back 1260 // down. If contended, repeat at step 3. If using TLABs normal-store 1261 // adjusted heap top back down; there is no contention. 1262 // 1263 // 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark 1264 // fields. 1265 // 1266 // 7) Merge with the slow-path; cast the raw memory pointer to the correct 1267 // oop flavor. 1268 // 1269 //============================================================================= 1270 // FastAllocateSizeLimit value is in DOUBLEWORDS. 1271 // Allocations bigger than this always go the slow route. 1272 // This value must be small enough that allocation attempts that need to 1273 // trigger exceptions go the slow route. Also, it must be small enough so 1274 // that heap_top + size_in_bytes does not wrap around the 4Gig limit. 1275 //=============================================================================j// 1276 // %%% Here is an old comment from parseHelper.cpp; is it outdated? 1277 // The allocator will coalesce int->oop copies away. See comment in 1278 // coalesce.cpp about how this works. It depends critically on the exact 1279 // code shape produced here, so if you are changing this code shape 1280 // make sure the GC info for the heap-top is correct in and around the 1281 // slow-path call. 1282 // 1283 1284 void PhaseMacroExpand::expand_allocate_common( 1285 AllocateNode* alloc, // allocation node to be expanded 1286 Node* length, // array length for an array allocation 1287 const TypeFunc* slow_call_type, // Type of slow call 1288 address slow_call_address // Address of slow call 1289 ) 1290 { 1291 Node* ctrl = alloc->in(TypeFunc::Control); 1292 Node* mem = alloc->in(TypeFunc::Memory); 1293 Node* i_o = alloc->in(TypeFunc::I_O); 1294 Node* size_in_bytes = alloc->in(AllocateNode::AllocSize); 1295 Node* klass_node = alloc->in(AllocateNode::KlassNode); 1296 Node* initial_slow_test = alloc->in(AllocateNode::InitialTest); 1297 assert(ctrl != NULL, "must have control"); 1298 1299 // We need a Region and corresponding Phi's to merge the slow-path and fast-path results. 1300 // they will not be used if "always_slow" is set 1301 enum { slow_result_path = 1, fast_result_path = 2 }; 1302 Node *result_region = NULL; 1303 Node *result_phi_rawmem = NULL; 1304 Node *result_phi_rawoop = NULL; 1305 Node *result_phi_i_o = NULL; 1306 1307 // The initial slow comparison is a size check, the comparison 1308 // we want to do is a BoolTest::gt 1309 bool expand_fast_path = true; 1310 int tv = _igvn.find_int_con(initial_slow_test, -1); 1311 if (tv >= 0) { 1312 // InitialTest has constant result 1313 // 0 - can fit in TLAB 1314 // 1 - always too big or negative 1315 assert(tv <= 1, "0 or 1 if a constant"); 1316 expand_fast_path = (tv == 0); 1317 initial_slow_test = NULL; 1318 } else { 1319 initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn); 1320 } 1321 1322 if (C->env()->dtrace_alloc_probes() || 1323 (!UseTLAB && !Universe::heap()->supports_inline_contig_alloc())) { 1324 // Force slow-path allocation 1325 expand_fast_path = false; 1326 initial_slow_test = NULL; 1327 } 1328 1329 bool allocation_has_use = (alloc->result_cast() != NULL); 1330 if (!allocation_has_use) { 1331 InitializeNode* init = alloc->initialization(); 1332 if (init != NULL) { 1333 init->remove(&_igvn); 1334 } 1335 if (expand_fast_path && (initial_slow_test == NULL)) { 1336 // Remove allocation node and return. 1337 // Size is a non-negative constant -> no initial check needed -> directly to fast path. 1338 // Also, no usages -> empty fast path -> no fall out to slow path -> nothing left. 1339 #ifndef PRODUCT 1340 if (PrintEliminateAllocations) { 1341 tty->print("NotUsed "); 1342 Node* res = alloc->proj_out_or_null(TypeFunc::Parms); 1343 if (res != NULL) { 1344 res->dump(); 1345 } else { 1346 alloc->dump(); 1347 } 1348 } 1349 #endif 1350 yank_alloc_node(alloc); 1351 return; 1352 } 1353 } 1354 1355 enum { too_big_or_final_path = 1, need_gc_path = 2 }; 1356 Node *slow_region = NULL; 1357 Node *toobig_false = ctrl; 1358 1359 // generate the initial test if necessary 1360 if (initial_slow_test != NULL ) { 1361 assert (expand_fast_path, "Only need test if there is a fast path"); 1362 slow_region = new RegionNode(3); 1363 1364 // Now make the initial failure test. Usually a too-big test but 1365 // might be a TRUE for finalizers or a fancy class check for 1366 // newInstance0. 1367 IfNode *toobig_iff = new IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN); 1368 transform_later(toobig_iff); 1369 // Plug the failing-too-big test into the slow-path region 1370 Node *toobig_true = new IfTrueNode( toobig_iff ); 1371 transform_later(toobig_true); 1372 slow_region ->init_req( too_big_or_final_path, toobig_true ); 1373 toobig_false = new IfFalseNode( toobig_iff ); 1374 transform_later(toobig_false); 1375 } else { 1376 // No initial test, just fall into next case 1377 assert(allocation_has_use || !expand_fast_path, "Should already have been handled"); 1378 toobig_false = ctrl; 1379 debug_only(slow_region = NodeSentinel); 1380 } 1381 1382 // If we are here there are several possibilities 1383 // - expand_fast_path is false - then only a slow path is expanded. That's it. 1384 // no_initial_check means a constant allocation. 1385 // - If check always evaluates to false -> expand_fast_path is false (see above) 1386 // - If check always evaluates to true -> directly into fast path (but may bailout to slowpath) 1387 // if !allocation_has_use the fast path is empty 1388 // if !allocation_has_use && no_initial_check 1389 // - Then there are no fastpath that can fall out to slowpath -> no allocation code at all. 1390 // removed by yank_alloc_node above. 1391 1392 Node *slow_mem = mem; // save the current memory state for slow path 1393 // generate the fast allocation code unless we know that the initial test will always go slow 1394 if (expand_fast_path) { 1395 // Fast path modifies only raw memory. 1396 if (mem->is_MergeMem()) { 1397 mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw); 1398 } 1399 1400 // allocate the Region and Phi nodes for the result 1401 result_region = new RegionNode(3); 1402 result_phi_rawmem = new PhiNode(result_region, Type::MEMORY, TypeRawPtr::BOTTOM); 1403 result_phi_i_o = new PhiNode(result_region, Type::ABIO); // I/O is used for Prefetch 1404 1405 // Grab regular I/O before optional prefetch may change it. 1406 // Slow-path does no I/O so just set it to the original I/O. 1407 result_phi_i_o->init_req(slow_result_path, i_o); 1408 1409 // Name successful fast-path variables 1410 Node* fast_oop_ctrl; 1411 Node* fast_oop_rawmem; 1412 if (allocation_has_use) { 1413 Node* needgc_ctrl = NULL; 1414 result_phi_rawoop = new PhiNode(result_region, TypeRawPtr::BOTTOM); 1415 1416 intx prefetch_lines = length != NULL ? AllocatePrefetchLines : AllocateInstancePrefetchLines; 1417 BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); 1418 Node* fast_oop = bs->obj_allocate(this, ctrl, mem, toobig_false, size_in_bytes, i_o, needgc_ctrl, 1419 fast_oop_ctrl, fast_oop_rawmem, 1420 prefetch_lines); 1421 1422 if (initial_slow_test != NULL) { 1423 // This completes all paths into the slow merge point 1424 slow_region->init_req(need_gc_path, needgc_ctrl); 1425 transform_later(slow_region); 1426 } else { 1427 // No initial slow path needed! 1428 // Just fall from the need-GC path straight into the VM call. 1429 slow_region = needgc_ctrl; 1430 } 1431 1432 InitializeNode* init = alloc->initialization(); 1433 fast_oop_rawmem = initialize_object(alloc, 1434 fast_oop_ctrl, fast_oop_rawmem, fast_oop, 1435 klass_node, length, size_in_bytes); 1436 expand_initialize_membar(alloc, init, fast_oop_ctrl, fast_oop_rawmem); 1437 expand_dtrace_alloc_probe(alloc, fast_oop, fast_oop_ctrl, fast_oop_rawmem); 1438 1439 result_phi_rawoop->init_req(fast_result_path, fast_oop); 1440 } else { 1441 assert (initial_slow_test != NULL, "sanity"); 1442 fast_oop_ctrl = toobig_false; 1443 fast_oop_rawmem = mem; 1444 transform_later(slow_region); 1445 } 1446 1447 // Plug in the successful fast-path into the result merge point 1448 result_region ->init_req(fast_result_path, fast_oop_ctrl); 1449 result_phi_i_o ->init_req(fast_result_path, i_o); 1450 result_phi_rawmem->init_req(fast_result_path, fast_oop_rawmem); 1451 } else { 1452 slow_region = ctrl; 1453 result_phi_i_o = i_o; // Rename it to use in the following code. 1454 } 1455 1456 // Generate slow-path call 1457 CallNode *call = new CallStaticJavaNode(slow_call_type, slow_call_address, 1458 OptoRuntime::stub_name(slow_call_address), 1459 alloc->jvms()->bci(), 1460 TypePtr::BOTTOM); 1461 call->init_req(TypeFunc::Control, slow_region); 1462 call->init_req(TypeFunc::I_O, top()); // does no i/o 1463 call->init_req(TypeFunc::Memory, slow_mem); // may gc ptrs 1464 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr)); 1465 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr)); 1466 1467 call->init_req(TypeFunc::Parms+0, klass_node); 1468 if (length != NULL) { 1469 call->init_req(TypeFunc::Parms+1, length); 1470 } 1471 1472 // Copy debug information and adjust JVMState information, then replace 1473 // allocate node with the call 1474 copy_call_debug_info((CallNode *) alloc, call); 1475 if (expand_fast_path) { 1476 call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON. 1477 } else { 1478 // Hook i_o projection to avoid its elimination during allocation 1479 // replacement (when only a slow call is generated). 1480 call->set_req(TypeFunc::I_O, result_phi_i_o); 1481 } 1482 _igvn.replace_node(alloc, call); 1483 transform_later(call); 1484 1485 // Identify the output projections from the allocate node and 1486 // adjust any references to them. 1487 // The control and io projections look like: 1488 // 1489 // v---Proj(ctrl) <-----+ v---CatchProj(ctrl) 1490 // Allocate Catch 1491 // ^---Proj(io) <-------+ ^---CatchProj(io) 1492 // 1493 // We are interested in the CatchProj nodes. 1494 // 1495 extract_call_projections(call); 1496 1497 // An allocate node has separate memory projections for the uses on 1498 // the control and i_o paths. Replace the control memory projection with 1499 // result_phi_rawmem (unless we are only generating a slow call when 1500 // both memory projections are combined) 1501 if (expand_fast_path && _memproj_fallthrough != NULL) { 1502 migrate_outs(_memproj_fallthrough, result_phi_rawmem); 1503 } 1504 // Now change uses of _memproj_catchall to use _memproj_fallthrough and delete 1505 // _memproj_catchall so we end up with a call that has only 1 memory projection. 1506 if (_memproj_catchall != NULL ) { 1507 if (_memproj_fallthrough == NULL) { 1508 _memproj_fallthrough = new ProjNode(call, TypeFunc::Memory); 1509 transform_later(_memproj_fallthrough); 1510 } 1511 migrate_outs(_memproj_catchall, _memproj_fallthrough); 1512 _igvn.remove_dead_node(_memproj_catchall); 1513 } 1514 1515 // An allocate node has separate i_o projections for the uses on the control 1516 // and i_o paths. Always replace the control i_o projection with result i_o 1517 // otherwise incoming i_o become dead when only a slow call is generated 1518 // (it is different from memory projections where both projections are 1519 // combined in such case). 1520 if (_ioproj_fallthrough != NULL) { 1521 migrate_outs(_ioproj_fallthrough, result_phi_i_o); 1522 } 1523 // Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete 1524 // _ioproj_catchall so we end up with a call that has only 1 i_o projection. 1525 if (_ioproj_catchall != NULL ) { 1526 if (_ioproj_fallthrough == NULL) { 1527 _ioproj_fallthrough = new ProjNode(call, TypeFunc::I_O); 1528 transform_later(_ioproj_fallthrough); 1529 } 1530 migrate_outs(_ioproj_catchall, _ioproj_fallthrough); 1531 _igvn.remove_dead_node(_ioproj_catchall); 1532 } 1533 1534 // if we generated only a slow call, we are done 1535 if (!expand_fast_path) { 1536 // Now we can unhook i_o. 1537 if (result_phi_i_o->outcnt() > 1) { 1538 call->set_req(TypeFunc::I_O, top()); 1539 } else { 1540 assert(result_phi_i_o->unique_ctrl_out() == call, "sanity"); 1541 // Case of new array with negative size known during compilation. 1542 // AllocateArrayNode::Ideal() optimization disconnect unreachable 1543 // following code since call to runtime will throw exception. 1544 // As result there will be no users of i_o after the call. 1545 // Leave i_o attached to this call to avoid problems in preceding graph. 1546 } 1547 return; 1548 } 1549 1550 if (_fallthroughcatchproj != NULL) { 1551 ctrl = _fallthroughcatchproj->clone(); 1552 transform_later(ctrl); 1553 _igvn.replace_node(_fallthroughcatchproj, result_region); 1554 } else { 1555 ctrl = top(); 1556 } 1557 Node *slow_result; 1558 if (_resproj == NULL) { 1559 // no uses of the allocation result 1560 slow_result = top(); 1561 } else { 1562 slow_result = _resproj->clone(); 1563 transform_later(slow_result); 1564 _igvn.replace_node(_resproj, result_phi_rawoop); 1565 } 1566 1567 // Plug slow-path into result merge point 1568 result_region->init_req( slow_result_path, ctrl); 1569 transform_later(result_region); 1570 if (allocation_has_use) { 1571 result_phi_rawoop->init_req(slow_result_path, slow_result); 1572 transform_later(result_phi_rawoop); 1573 } 1574 result_phi_rawmem->init_req(slow_result_path, _memproj_fallthrough); 1575 transform_later(result_phi_rawmem); 1576 transform_later(result_phi_i_o); 1577 // This completes all paths into the result merge point 1578 } 1579 1580 // Remove alloc node that has no uses. 1581 void PhaseMacroExpand::yank_alloc_node(AllocateNode* alloc) { 1582 Node* ctrl = alloc->in(TypeFunc::Control); 1583 Node* mem = alloc->in(TypeFunc::Memory); 1584 Node* i_o = alloc->in(TypeFunc::I_O); 1585 1586 extract_call_projections(alloc); 1587 if (_resproj != NULL) { 1588 for (DUIterator_Fast imax, i = _resproj->fast_outs(imax); i < imax; i++) { 1589 Node* use = _resproj->fast_out(i); 1590 use->isa_MemBar()->remove(&_igvn); 1591 --imax; 1592 --i; // back up iterator 1593 } 1594 assert(_resproj->outcnt() == 0, "all uses must be deleted"); 1595 _igvn.remove_dead_node(_resproj); 1596 } 1597 if (_fallthroughcatchproj != NULL) { 1598 migrate_outs(_fallthroughcatchproj, ctrl); 1599 _igvn.remove_dead_node(_fallthroughcatchproj); 1600 } 1601 if (_catchallcatchproj != NULL) { 1602 _igvn.rehash_node_delayed(_catchallcatchproj); 1603 _catchallcatchproj->set_req(0, top()); 1604 } 1605 if (_fallthroughproj != NULL) { 1606 Node* catchnode = _fallthroughproj->unique_ctrl_out(); 1607 _igvn.remove_dead_node(catchnode); 1608 _igvn.remove_dead_node(_fallthroughproj); 1609 } 1610 if (_memproj_fallthrough != NULL) { 1611 migrate_outs(_memproj_fallthrough, mem); 1612 _igvn.remove_dead_node(_memproj_fallthrough); 1613 } 1614 if (_ioproj_fallthrough != NULL) { 1615 migrate_outs(_ioproj_fallthrough, i_o); 1616 _igvn.remove_dead_node(_ioproj_fallthrough); 1617 } 1618 if (_memproj_catchall != NULL) { 1619 _igvn.rehash_node_delayed(_memproj_catchall); 1620 _memproj_catchall->set_req(0, top()); 1621 } 1622 if (_ioproj_catchall != NULL) { 1623 _igvn.rehash_node_delayed(_ioproj_catchall); 1624 _ioproj_catchall->set_req(0, top()); 1625 } 1626 #ifndef PRODUCT 1627 if (PrintEliminateAllocations) { 1628 if (alloc->is_AllocateArray()) { 1629 tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx); 1630 } else { 1631 tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx); 1632 } 1633 } 1634 #endif 1635 _igvn.remove_dead_node(alloc); 1636 } 1637 1638 void PhaseMacroExpand::expand_initialize_membar(AllocateNode* alloc, InitializeNode* init, 1639 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem) { 1640 // If initialization is performed by an array copy, any required 1641 // MemBarStoreStore was already added. If the object does not 1642 // escape no need for a MemBarStoreStore. If the object does not 1643 // escape in its initializer and memory barrier (MemBarStoreStore or 1644 // stronger) is already added at exit of initializer, also no need 1645 // for a MemBarStoreStore. Otherwise we need a MemBarStoreStore 1646 // so that stores that initialize this object can't be reordered 1647 // with a subsequent store that makes this object accessible by 1648 // other threads. 1649 // Other threads include java threads and JVM internal threads 1650 // (for example concurrent GC threads). Current concurrent GC 1651 // implementation: G1 will not scan newly created object, 1652 // so it's safe to skip storestore barrier when allocation does 1653 // not escape. 1654 if (!alloc->does_not_escape_thread() && 1655 !alloc->is_allocation_MemBar_redundant() && 1656 (init == NULL || !init->is_complete_with_arraycopy())) { 1657 if (init == NULL || init->req() < InitializeNode::RawStores) { 1658 // No InitializeNode or no stores captured by zeroing 1659 // elimination. Simply add the MemBarStoreStore after object 1660 // initialization. 1661 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot); 1662 transform_later(mb); 1663 1664 mb->init_req(TypeFunc::Memory, fast_oop_rawmem); 1665 mb->init_req(TypeFunc::Control, fast_oop_ctrl); 1666 fast_oop_ctrl = new ProjNode(mb, TypeFunc::Control); 1667 transform_later(fast_oop_ctrl); 1668 fast_oop_rawmem = new ProjNode(mb, TypeFunc::Memory); 1669 transform_later(fast_oop_rawmem); 1670 } else { 1671 // Add the MemBarStoreStore after the InitializeNode so that 1672 // all stores performing the initialization that were moved 1673 // before the InitializeNode happen before the storestore 1674 // barrier. 1675 1676 Node* init_ctrl = init->proj_out_or_null(TypeFunc::Control); 1677 Node* init_mem = init->proj_out_or_null(TypeFunc::Memory); 1678 1679 MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot); 1680 transform_later(mb); 1681 1682 Node* ctrl = new ProjNode(init, TypeFunc::Control); 1683 transform_later(ctrl); 1684 Node* mem = new ProjNode(init, TypeFunc::Memory); 1685 transform_later(mem); 1686 1687 // The MemBarStoreStore depends on control and memory coming 1688 // from the InitializeNode 1689 mb->init_req(TypeFunc::Memory, mem); 1690 mb->init_req(TypeFunc::Control, ctrl); 1691 1692 ctrl = new ProjNode(mb, TypeFunc::Control); 1693 transform_later(ctrl); 1694 mem = new ProjNode(mb, TypeFunc::Memory); 1695 transform_later(mem); 1696 1697 // All nodes that depended on the InitializeNode for control 1698 // and memory must now depend on the MemBarNode that itself 1699 // depends on the InitializeNode 1700 if (init_ctrl != NULL) { 1701 _igvn.replace_node(init_ctrl, ctrl); 1702 } 1703 if (init_mem != NULL) { 1704 _igvn.replace_node(init_mem, mem); 1705 } 1706 } 1707 } 1708 } 1709 1710 void PhaseMacroExpand::expand_dtrace_alloc_probe(AllocateNode* alloc, Node* oop, 1711 Node*& ctrl, Node*& rawmem) { 1712 if (C->env()->dtrace_extended_probes()) { 1713 // Slow-path call 1714 int size = TypeFunc::Parms + 2; 1715 CallLeafNode *call = new CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(), 1716 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base), 1717 "dtrace_object_alloc", 1718 TypeRawPtr::BOTTOM); 1719 1720 // Get base of thread-local storage area 1721 Node* thread = new ThreadLocalNode(); 1722 transform_later(thread); 1723 1724 call->init_req(TypeFunc::Parms + 0, thread); 1725 call->init_req(TypeFunc::Parms + 1, oop); 1726 call->init_req(TypeFunc::Control, ctrl); 1727 call->init_req(TypeFunc::I_O , top()); // does no i/o 1728 call->init_req(TypeFunc::Memory , ctrl); 1729 call->init_req(TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr)); 1730 call->init_req(TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr)); 1731 transform_later(call); 1732 ctrl = new ProjNode(call, TypeFunc::Control); 1733 transform_later(ctrl); 1734 rawmem = new ProjNode(call, TypeFunc::Memory); 1735 transform_later(rawmem); 1736 } 1737 } 1738 1739 // Helper for PhaseMacroExpand::expand_allocate_common. 1740 // Initializes the newly-allocated storage. 1741 Node* 1742 PhaseMacroExpand::initialize_object(AllocateNode* alloc, 1743 Node* control, Node* rawmem, Node* object, 1744 Node* klass_node, Node* length, 1745 Node* size_in_bytes) { 1746 InitializeNode* init = alloc->initialization(); 1747 // Store the klass & mark bits 1748 Node* mark_node = alloc->make_ideal_mark(&_igvn, object, control, rawmem); 1749 if (!mark_node->is_Con()) { 1750 transform_later(mark_node); 1751 } 1752 rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, TypeX_X->basic_type()); 1753 1754 rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_METADATA); 1755 int header_size = alloc->minimum_header_size(); // conservatively small 1756 1757 // Array length 1758 if (length != NULL) { // Arrays need length field 1759 rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT); 1760 // conservatively small header size: 1761 header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE); 1762 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass(); 1763 if (k->is_array_klass()) // we know the exact header size in most cases: 1764 header_size = Klass::layout_helper_header_size(k->layout_helper()); 1765 } 1766 1767 // Clear the object body, if necessary. 1768 if (init == NULL) { 1769 // The init has somehow disappeared; be cautious and clear everything. 1770 // 1771 // This can happen if a node is allocated but an uncommon trap occurs 1772 // immediately. In this case, the Initialize gets associated with the 1773 // trap, and may be placed in a different (outer) loop, if the Allocate 1774 // is in a loop. If (this is rare) the inner loop gets unrolled, then 1775 // there can be two Allocates to one Initialize. The answer in all these 1776 // edge cases is safety first. It is always safe to clear immediately 1777 // within an Allocate, and then (maybe or maybe not) clear some more later. 1778 if (!(UseTLAB && ZeroTLAB)) { 1779 rawmem = ClearArrayNode::clear_memory(control, rawmem, object, 1780 header_size, size_in_bytes, 1781 &_igvn); 1782 } 1783 } else { 1784 if (!init->is_complete()) { 1785 // Try to win by zeroing only what the init does not store. 1786 // We can also try to do some peephole optimizations, 1787 // such as combining some adjacent subword stores. 1788 rawmem = init->complete_stores(control, rawmem, object, 1789 header_size, size_in_bytes, &_igvn); 1790 } 1791 // We have no more use for this link, since the AllocateNode goes away: 1792 init->set_req(InitializeNode::RawAddress, top()); 1793 // (If we keep the link, it just confuses the register allocator, 1794 // who thinks he sees a real use of the address by the membar.) 1795 } 1796 1797 return rawmem; 1798 } 1799 1800 // Generate prefetch instructions for next allocations. 1801 Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false, 1802 Node*& contended_phi_rawmem, 1803 Node* old_eden_top, Node* new_eden_top, 1804 intx lines) { 1805 enum { fall_in_path = 1, pf_path = 2 }; 1806 if( UseTLAB && AllocatePrefetchStyle == 2 ) { 1807 // Generate prefetch allocation with watermark check. 1808 // As an allocation hits the watermark, we will prefetch starting 1809 // at a "distance" away from watermark. 1810 1811 Node *pf_region = new RegionNode(3); 1812 Node *pf_phi_rawmem = new PhiNode( pf_region, Type::MEMORY, 1813 TypeRawPtr::BOTTOM ); 1814 // I/O is used for Prefetch 1815 Node *pf_phi_abio = new PhiNode( pf_region, Type::ABIO ); 1816 1817 Node *thread = new ThreadLocalNode(); 1818 transform_later(thread); 1819 1820 Node *eden_pf_adr = new AddPNode( top()/*not oop*/, thread, 1821 _igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) ); 1822 transform_later(eden_pf_adr); 1823 1824 Node *old_pf_wm = new LoadPNode(needgc_false, 1825 contended_phi_rawmem, eden_pf_adr, 1826 TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, 1827 MemNode::unordered); 1828 transform_later(old_pf_wm); 1829 1830 // check against new_eden_top 1831 Node *need_pf_cmp = new CmpPNode( new_eden_top, old_pf_wm ); 1832 transform_later(need_pf_cmp); 1833 Node *need_pf_bol = new BoolNode( need_pf_cmp, BoolTest::ge ); 1834 transform_later(need_pf_bol); 1835 IfNode *need_pf_iff = new IfNode( needgc_false, need_pf_bol, 1836 PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN ); 1837 transform_later(need_pf_iff); 1838 1839 // true node, add prefetchdistance 1840 Node *need_pf_true = new IfTrueNode( need_pf_iff ); 1841 transform_later(need_pf_true); 1842 1843 Node *need_pf_false = new IfFalseNode( need_pf_iff ); 1844 transform_later(need_pf_false); 1845 1846 Node *new_pf_wmt = new AddPNode( top(), old_pf_wm, 1847 _igvn.MakeConX(AllocatePrefetchDistance) ); 1848 transform_later(new_pf_wmt ); 1849 new_pf_wmt->set_req(0, need_pf_true); 1850 1851 Node *store_new_wmt = new StorePNode(need_pf_true, 1852 contended_phi_rawmem, eden_pf_adr, 1853 TypeRawPtr::BOTTOM, new_pf_wmt, 1854 MemNode::unordered); 1855 transform_later(store_new_wmt); 1856 1857 // adding prefetches 1858 pf_phi_abio->init_req( fall_in_path, i_o ); 1859 1860 Node *prefetch_adr; 1861 Node *prefetch; 1862 uint step_size = AllocatePrefetchStepSize; 1863 uint distance = 0; 1864 1865 for ( intx i = 0; i < lines; i++ ) { 1866 prefetch_adr = new AddPNode( old_pf_wm, new_pf_wmt, 1867 _igvn.MakeConX(distance) ); 1868 transform_later(prefetch_adr); 1869 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr ); 1870 transform_later(prefetch); 1871 distance += step_size; 1872 i_o = prefetch; 1873 } 1874 pf_phi_abio->set_req( pf_path, i_o ); 1875 1876 pf_region->init_req( fall_in_path, need_pf_false ); 1877 pf_region->init_req( pf_path, need_pf_true ); 1878 1879 pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem ); 1880 pf_phi_rawmem->init_req( pf_path, store_new_wmt ); 1881 1882 transform_later(pf_region); 1883 transform_later(pf_phi_rawmem); 1884 transform_later(pf_phi_abio); 1885 1886 needgc_false = pf_region; 1887 contended_phi_rawmem = pf_phi_rawmem; 1888 i_o = pf_phi_abio; 1889 } else if( UseTLAB && AllocatePrefetchStyle == 3 ) { 1890 // Insert a prefetch instruction for each allocation. 1891 // This code is used to generate 1 prefetch instruction per cache line. 1892 1893 // Generate several prefetch instructions. 1894 uint step_size = AllocatePrefetchStepSize; 1895 uint distance = AllocatePrefetchDistance; 1896 1897 // Next cache address. 1898 Node *cache_adr = new AddPNode(old_eden_top, old_eden_top, 1899 _igvn.MakeConX(step_size + distance)); 1900 transform_later(cache_adr); 1901 cache_adr = new CastP2XNode(needgc_false, cache_adr); 1902 transform_later(cache_adr); 1903 // Address is aligned to execute prefetch to the beginning of cache line size 1904 // (it is important when BIS instruction is used on SPARC as prefetch). 1905 Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1)); 1906 cache_adr = new AndXNode(cache_adr, mask); 1907 transform_later(cache_adr); 1908 cache_adr = new CastX2PNode(cache_adr); 1909 transform_later(cache_adr); 1910 1911 // Prefetch 1912 Node *prefetch = new PrefetchAllocationNode( contended_phi_rawmem, cache_adr ); 1913 prefetch->set_req(0, needgc_false); 1914 transform_later(prefetch); 1915 contended_phi_rawmem = prefetch; 1916 Node *prefetch_adr; 1917 distance = step_size; 1918 for ( intx i = 1; i < lines; i++ ) { 1919 prefetch_adr = new AddPNode( cache_adr, cache_adr, 1920 _igvn.MakeConX(distance) ); 1921 transform_later(prefetch_adr); 1922 prefetch = new PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr ); 1923 transform_later(prefetch); 1924 distance += step_size; 1925 contended_phi_rawmem = prefetch; 1926 } 1927 } else if( AllocatePrefetchStyle > 0 ) { 1928 // Insert a prefetch for each allocation only on the fast-path 1929 Node *prefetch_adr; 1930 Node *prefetch; 1931 // Generate several prefetch instructions. 1932 uint step_size = AllocatePrefetchStepSize; 1933 uint distance = AllocatePrefetchDistance; 1934 for ( intx i = 0; i < lines; i++ ) { 1935 prefetch_adr = new AddPNode( old_eden_top, new_eden_top, 1936 _igvn.MakeConX(distance) ); 1937 transform_later(prefetch_adr); 1938 prefetch = new PrefetchAllocationNode( i_o, prefetch_adr ); 1939 // Do not let it float too high, since if eden_top == eden_end, 1940 // both might be null. 1941 if( i == 0 ) { // Set control for first prefetch, next follows it 1942 prefetch->init_req(0, needgc_false); 1943 } 1944 transform_later(prefetch); 1945 distance += step_size; 1946 i_o = prefetch; 1947 } 1948 } 1949 return i_o; 1950 } 1951 1952 1953 void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) { 1954 expand_allocate_common(alloc, NULL, 1955 OptoRuntime::new_instance_Type(), 1956 OptoRuntime::new_instance_Java()); 1957 } 1958 1959 void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) { 1960 Node* length = alloc->in(AllocateNode::ALength); 1961 InitializeNode* init = alloc->initialization(); 1962 Node* klass_node = alloc->in(AllocateNode::KlassNode); 1963 ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass(); 1964 address slow_call_address; // Address of slow call 1965 if (init != NULL && init->is_complete_with_arraycopy() && 1966 k->is_type_array_klass()) { 1967 // Don't zero type array during slow allocation in VM since 1968 // it will be initialized later by arraycopy in compiled code. 1969 slow_call_address = OptoRuntime::new_array_nozero_Java(); 1970 } else { 1971 slow_call_address = OptoRuntime::new_array_Java(); 1972 } 1973 expand_allocate_common(alloc, length, 1974 OptoRuntime::new_array_Type(), 1975 slow_call_address); 1976 } 1977 1978 //-------------------mark_eliminated_box---------------------------------- 1979 // 1980 // During EA obj may point to several objects but after few ideal graph 1981 // transformations (CCP) it may point to only one non escaping object 1982 // (but still using phi), corresponding locks and unlocks will be marked 1983 // for elimination. Later obj could be replaced with a new node (new phi) 1984 // and which does not have escape information. And later after some graph 1985 // reshape other locks and unlocks (which were not marked for elimination 1986 // before) are connected to this new obj (phi) but they still will not be 1987 // marked for elimination since new obj has no escape information. 1988 // Mark all associated (same box and obj) lock and unlock nodes for 1989 // elimination if some of them marked already. 1990 void PhaseMacroExpand::mark_eliminated_box(Node* oldbox, Node* obj) { 1991 if (oldbox->as_BoxLock()->is_eliminated()) 1992 return; // This BoxLock node was processed already. 1993 1994 // New implementation (EliminateNestedLocks) has separate BoxLock 1995 // node for each locked region so mark all associated locks/unlocks as 1996 // eliminated even if different objects are referenced in one locked region 1997 // (for example, OSR compilation of nested loop inside locked scope). 1998 if (EliminateNestedLocks || 1999 oldbox->as_BoxLock()->is_simple_lock_region(NULL, obj)) { 2000 // Box is used only in one lock region. Mark this box as eliminated. 2001 _igvn.hash_delete(oldbox); 2002 oldbox->as_BoxLock()->set_eliminated(); // This changes box's hash value 2003 _igvn.hash_insert(oldbox); 2004 2005 for (uint i = 0; i < oldbox->outcnt(); i++) { 2006 Node* u = oldbox->raw_out(i); 2007 if (u->is_AbstractLock() && !u->as_AbstractLock()->is_non_esc_obj()) { 2008 AbstractLockNode* alock = u->as_AbstractLock(); 2009 // Check lock's box since box could be referenced by Lock's debug info. 2010 if (alock->box_node() == oldbox) { 2011 // Mark eliminated all related locks and unlocks. 2012 #ifdef ASSERT 2013 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc4"); 2014 #endif 2015 alock->set_non_esc_obj(); 2016 } 2017 } 2018 } 2019 return; 2020 } 2021 2022 // Create new "eliminated" BoxLock node and use it in monitor debug info 2023 // instead of oldbox for the same object. 2024 BoxLockNode* newbox = oldbox->clone()->as_BoxLock(); 2025 2026 // Note: BoxLock node is marked eliminated only here and it is used 2027 // to indicate that all associated lock and unlock nodes are marked 2028 // for elimination. 2029 newbox->set_eliminated(); 2030 transform_later(newbox); 2031 2032 // Replace old box node with new box for all users of the same object. 2033 for (uint i = 0; i < oldbox->outcnt();) { 2034 bool next_edge = true; 2035 2036 Node* u = oldbox->raw_out(i); 2037 if (u->is_AbstractLock()) { 2038 AbstractLockNode* alock = u->as_AbstractLock(); 2039 if (alock->box_node() == oldbox && alock->obj_node()->eqv_uncast(obj)) { 2040 // Replace Box and mark eliminated all related locks and unlocks. 2041 #ifdef ASSERT 2042 alock->log_lock_optimization(C, "eliminate_lock_set_non_esc5"); 2043 #endif 2044 alock->set_non_esc_obj(); 2045 _igvn.rehash_node_delayed(alock); 2046 alock->set_box_node(newbox); 2047 next_edge = false; 2048 } 2049 } 2050 if (u->is_FastLock() && u->as_FastLock()->obj_node()->eqv_uncast(obj)) { 2051 FastLockNode* flock = u->as_FastLock(); 2052 assert(flock->box_node() == oldbox, "sanity"); 2053 _igvn.rehash_node_delayed(flock); 2054 flock->set_box_node(newbox); 2055 next_edge = false; 2056 } 2057 2058 // Replace old box in monitor debug info. 2059 if (u->is_SafePoint() && u->as_SafePoint()->jvms()) { 2060 SafePointNode* sfn = u->as_SafePoint(); 2061 JVMState* youngest_jvms = sfn->jvms(); 2062 int max_depth = youngest_jvms->depth(); 2063 for (int depth = 1; depth <= max_depth; depth++) { 2064 JVMState* jvms = youngest_jvms->of_depth(depth); 2065 int num_mon = jvms->nof_monitors(); 2066 // Loop over monitors 2067 for (int idx = 0; idx < num_mon; idx++) { 2068 Node* obj_node = sfn->monitor_obj(jvms, idx); 2069 Node* box_node = sfn->monitor_box(jvms, idx); 2070 if (box_node == oldbox && obj_node->eqv_uncast(obj)) { 2071 int j = jvms->monitor_box_offset(idx); 2072 _igvn.replace_input_of(u, j, newbox); 2073 next_edge = false; 2074 } 2075 } 2076 } 2077 } 2078 if (next_edge) i++; 2079 } 2080 } 2081 2082 //-----------------------mark_eliminated_locking_nodes----------------------- 2083 void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) { 2084 if (EliminateNestedLocks) { 2085 if (alock->is_nested()) { 2086 assert(alock->box_node()->as_BoxLock()->is_eliminated(), "sanity"); 2087 return; 2088 } else if (!alock->is_non_esc_obj()) { // Not eliminated or coarsened 2089 // Only Lock node has JVMState needed here. 2090 // Not that preceding claim is documented anywhere else. 2091 if (alock->jvms() != NULL) { 2092 if (alock->as_Lock()->is_nested_lock_region()) { 2093 // Mark eliminated related nested locks and unlocks. 2094 Node* obj = alock->obj_node(); 2095 BoxLockNode* box_node = alock->box_node()->as_BoxLock(); 2096 assert(!box_node->is_eliminated(), "should not be marked yet"); 2097 // Note: BoxLock node is marked eliminated only here 2098 // and it is used to indicate that all associated lock 2099 // and unlock nodes are marked for elimination. 2100 box_node->set_eliminated(); // Box's hash is always NO_HASH here 2101 for (uint i = 0; i < box_node->outcnt(); i++) { 2102 Node* u = box_node->raw_out(i); 2103 if (u->is_AbstractLock()) { 2104 alock = u->as_AbstractLock(); 2105 if (alock->box_node() == box_node) { 2106 // Verify that this Box is referenced only by related locks. 2107 assert(alock->obj_node()->eqv_uncast(obj), ""); 2108 // Mark all related locks and unlocks. 2109 #ifdef ASSERT 2110 alock->log_lock_optimization(C, "eliminate_lock_set_nested"); 2111 #endif 2112 alock->set_nested(); 2113 } 2114 } 2115 } 2116 } else { 2117 #ifdef ASSERT 2118 alock->log_lock_optimization(C, "eliminate_lock_NOT_nested_lock_region"); 2119 if (C->log() != NULL) 2120 alock->as_Lock()->is_nested_lock_region(C); // rerun for debugging output 2121 #endif 2122 } 2123 } 2124 return; 2125 } 2126 // Process locks for non escaping object 2127 assert(alock->is_non_esc_obj(), ""); 2128 } // EliminateNestedLocks 2129 2130 if (alock->is_non_esc_obj()) { // Lock is used for non escaping object 2131 // Look for all locks of this object and mark them and 2132 // corresponding BoxLock nodes as eliminated. 2133 Node* obj = alock->obj_node(); 2134 for (uint j = 0; j < obj->outcnt(); j++) { 2135 Node* o = obj->raw_out(j); 2136 if (o->is_AbstractLock() && 2137 o->as_AbstractLock()->obj_node()->eqv_uncast(obj)) { 2138 alock = o->as_AbstractLock(); 2139 Node* box = alock->box_node(); 2140 // Replace old box node with new eliminated box for all users 2141 // of the same object and mark related locks as eliminated. 2142 mark_eliminated_box(box, obj); 2143 } 2144 } 2145 } 2146 } 2147 2148 // we have determined that this lock/unlock can be eliminated, we simply 2149 // eliminate the node without expanding it. 2150 // 2151 // Note: The membar's associated with the lock/unlock are currently not 2152 // eliminated. This should be investigated as a future enhancement. 2153 // 2154 bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) { 2155 2156 if (!alock->is_eliminated()) { 2157 return false; 2158 } 2159 #ifdef ASSERT 2160 if (!alock->is_coarsened()) { 2161 // Check that new "eliminated" BoxLock node is created. 2162 BoxLockNode* oldbox = alock->box_node()->as_BoxLock(); 2163 assert(oldbox->is_eliminated(), "should be done already"); 2164 } 2165 #endif 2166 2167 alock->log_lock_optimization(C, "eliminate_lock"); 2168 2169 #ifndef PRODUCT 2170 if (PrintEliminateLocks) { 2171 if (alock->is_Lock()) { 2172 tty->print_cr("++++ Eliminated: %d Lock", alock->_idx); 2173 } else { 2174 tty->print_cr("++++ Eliminated: %d Unlock", alock->_idx); 2175 } 2176 } 2177 #endif 2178 2179 Node* mem = alock->in(TypeFunc::Memory); 2180 Node* ctrl = alock->in(TypeFunc::Control); 2181 guarantee(ctrl != NULL, "missing control projection, cannot replace_node() with NULL"); 2182 2183 extract_call_projections(alock); 2184 // There are 2 projections from the lock. The lock node will 2185 // be deleted when its last use is subsumed below. 2186 assert(alock->outcnt() == 2 && 2187 _fallthroughproj != NULL && 2188 _memproj_fallthrough != NULL, 2189 "Unexpected projections from Lock/Unlock"); 2190 2191 Node* fallthroughproj = _fallthroughproj; 2192 Node* memproj_fallthrough = _memproj_fallthrough; 2193 2194 // The memory projection from a lock/unlock is RawMem 2195 // The input to a Lock is merged memory, so extract its RawMem input 2196 // (unless the MergeMem has been optimized away.) 2197 if (alock->is_Lock()) { 2198 // Seach for MemBarAcquireLock node and delete it also. 2199 MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar(); 2200 assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, ""); 2201 Node* ctrlproj = membar->proj_out(TypeFunc::Control); 2202 Node* memproj = membar->proj_out(TypeFunc::Memory); 2203 _igvn.replace_node(ctrlproj, fallthroughproj); 2204 _igvn.replace_node(memproj, memproj_fallthrough); 2205 2206 // Delete FastLock node also if this Lock node is unique user 2207 // (a loop peeling may clone a Lock node). 2208 Node* flock = alock->as_Lock()->fastlock_node(); 2209 if (flock->outcnt() == 1) { 2210 assert(flock->unique_out() == alock, "sanity"); 2211 _igvn.replace_node(flock, top()); 2212 } 2213 } 2214 2215 // Seach for MemBarReleaseLock node and delete it also. 2216 if (alock->is_Unlock() && ctrl->is_Proj() && ctrl->in(0)->is_MemBar()) { 2217 MemBarNode* membar = ctrl->in(0)->as_MemBar(); 2218 assert(membar->Opcode() == Op_MemBarReleaseLock && 2219 mem->is_Proj() && membar == mem->in(0), ""); 2220 _igvn.replace_node(fallthroughproj, ctrl); 2221 _igvn.replace_node(memproj_fallthrough, mem); 2222 fallthroughproj = ctrl; 2223 memproj_fallthrough = mem; 2224 ctrl = membar->in(TypeFunc::Control); 2225 mem = membar->in(TypeFunc::Memory); 2226 } 2227 2228 _igvn.replace_node(fallthroughproj, ctrl); 2229 _igvn.replace_node(memproj_fallthrough, mem); 2230 return true; 2231 } 2232 2233 2234 //------------------------------expand_lock_node---------------------- 2235 void PhaseMacroExpand::expand_lock_node(LockNode *lock) { 2236 2237 Node* ctrl = lock->in(TypeFunc::Control); 2238 Node* mem = lock->in(TypeFunc::Memory); 2239 Node* obj = lock->obj_node(); 2240 Node* box = lock->box_node(); 2241 Node* flock = lock->fastlock_node(); 2242 2243 assert(!box->as_BoxLock()->is_eliminated(), "sanity"); 2244 2245 // Make the merge point 2246 Node *region; 2247 Node *mem_phi; 2248 Node *slow_path; 2249 2250 if (UseOptoBiasInlining) { 2251 /* 2252 * See the full description in MacroAssembler::biased_locking_enter(). 2253 * 2254 * if( (mark_word & biased_lock_mask) == biased_lock_pattern ) { 2255 * // The object is biased. 2256 * proto_node = klass->prototype_header; 2257 * o_node = thread | proto_node; 2258 * x_node = o_node ^ mark_word; 2259 * if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ? 2260 * // Done. 2261 * } else { 2262 * if( (x_node & biased_lock_mask) != 0 ) { 2263 * // The klass's prototype header is no longer biased. 2264 * cas(&mark_word, mark_word, proto_node) 2265 * goto cas_lock; 2266 * } else { 2267 * // The klass's prototype header is still biased. 2268 * if( (x_node & epoch_mask) != 0 ) { // Expired epoch? 2269 * old = mark_word; 2270 * new = o_node; 2271 * } else { 2272 * // Different thread or anonymous biased. 2273 * old = mark_word & (epoch_mask | age_mask | biased_lock_mask); 2274 * new = thread | old; 2275 * } 2276 * // Try to rebias. 2277 * if( cas(&mark_word, old, new) == 0 ) { 2278 * // Done. 2279 * } else { 2280 * goto slow_path; // Failed. 2281 * } 2282 * } 2283 * } 2284 * } else { 2285 * // The object is not biased. 2286 * cas_lock: 2287 * if( FastLock(obj) == 0 ) { 2288 * // Done. 2289 * } else { 2290 * slow_path: 2291 * OptoRuntime::complete_monitor_locking_Java(obj); 2292 * } 2293 * } 2294 */ 2295 2296 region = new RegionNode(5); 2297 // create a Phi for the memory state 2298 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); 2299 2300 Node* fast_lock_region = new RegionNode(3); 2301 Node* fast_lock_mem_phi = new PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM); 2302 2303 // First, check mark word for the biased lock pattern. 2304 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type()); 2305 2306 // Get fast path - mark word has the biased lock pattern. 2307 ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node, 2308 markWord::biased_lock_mask_in_place, 2309 markWord::biased_lock_pattern, true); 2310 // fast_lock_region->in(1) is set to slow path. 2311 fast_lock_mem_phi->init_req(1, mem); 2312 2313 // Now check that the lock is biased to the current thread and has 2314 // the same epoch and bias as Klass::_prototype_header. 2315 2316 // Special-case a fresh allocation to avoid building nodes: 2317 Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn); 2318 if (klass_node == NULL) { 2319 Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes()); 2320 klass_node = transform_later(LoadKlassNode::make(_igvn, NULL, mem, k_adr, _igvn.type(k_adr)->is_ptr())); 2321 #ifdef _LP64 2322 if (UseCompressedClassPointers && klass_node->is_DecodeNKlass()) { 2323 assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity"); 2324 klass_node->in(1)->init_req(0, ctrl); 2325 } else 2326 #endif 2327 klass_node->init_req(0, ctrl); 2328 } 2329 Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type()); 2330 2331 Node* thread = transform_later(new ThreadLocalNode()); 2332 Node* cast_thread = transform_later(new CastP2XNode(ctrl, thread)); 2333 Node* o_node = transform_later(new OrXNode(cast_thread, proto_node)); 2334 Node* x_node = transform_later(new XorXNode(o_node, mark_node)); 2335 2336 // Get slow path - mark word does NOT match the value. 2337 STATIC_ASSERT(markWord::age_mask_in_place <= INT_MAX); 2338 Node* not_biased_ctrl = opt_bits_test(ctrl, region, 3, x_node, 2339 (~(int)markWord::age_mask_in_place), 0); 2340 // region->in(3) is set to fast path - the object is biased to the current thread. 2341 mem_phi->init_req(3, mem); 2342 2343 2344 // Mark word does NOT match the value (thread | Klass::_prototype_header). 2345 2346 2347 // First, check biased pattern. 2348 // Get fast path - _prototype_header has the same biased lock pattern. 2349 ctrl = opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node, 2350 markWord::biased_lock_mask_in_place, 0, true); 2351 2352 not_biased_ctrl = fast_lock_region->in(2); // Slow path 2353 // fast_lock_region->in(2) - the prototype header is no longer biased 2354 // and we have to revoke the bias on this object. 2355 // We are going to try to reset the mark of this object to the prototype 2356 // value and fall through to the CAS-based locking scheme. 2357 Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes()); 2358 Node* cas = new StoreXConditionalNode(not_biased_ctrl, mem, adr, 2359 proto_node, mark_node); 2360 transform_later(cas); 2361 Node* proj = transform_later(new SCMemProjNode(cas)); 2362 fast_lock_mem_phi->init_req(2, proj); 2363 2364 2365 // Second, check epoch bits. 2366 Node* rebiased_region = new RegionNode(3); 2367 Node* old_phi = new PhiNode( rebiased_region, TypeX_X); 2368 Node* new_phi = new PhiNode( rebiased_region, TypeX_X); 2369 2370 // Get slow path - mark word does NOT match epoch bits. 2371 Node* epoch_ctrl = opt_bits_test(ctrl, rebiased_region, 1, x_node, 2372 markWord::epoch_mask_in_place, 0); 2373 // The epoch of the current bias is not valid, attempt to rebias the object 2374 // toward the current thread. 2375 rebiased_region->init_req(2, epoch_ctrl); 2376 old_phi->init_req(2, mark_node); 2377 new_phi->init_req(2, o_node); 2378 2379 // rebiased_region->in(1) is set to fast path. 2380 // The epoch of the current bias is still valid but we know 2381 // nothing about the owner; it might be set or it might be clear. 2382 Node* cmask = MakeConX(markWord::biased_lock_mask_in_place | 2383 markWord::age_mask_in_place | 2384 markWord::epoch_mask_in_place); 2385 Node* old = transform_later(new AndXNode(mark_node, cmask)); 2386 cast_thread = transform_later(new CastP2XNode(ctrl, thread)); 2387 Node* new_mark = transform_later(new OrXNode(cast_thread, old)); 2388 old_phi->init_req(1, old); 2389 new_phi->init_req(1, new_mark); 2390 2391 transform_later(rebiased_region); 2392 transform_later(old_phi); 2393 transform_later(new_phi); 2394 2395 // Try to acquire the bias of the object using an atomic operation. 2396 // If this fails we will go in to the runtime to revoke the object's bias. 2397 cas = new StoreXConditionalNode(rebiased_region, mem, adr, new_phi, old_phi); 2398 transform_later(cas); 2399 proj = transform_later(new SCMemProjNode(cas)); 2400 2401 // Get slow path - Failed to CAS. 2402 not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0); 2403 mem_phi->init_req(4, proj); 2404 // region->in(4) is set to fast path - the object is rebiased to the current thread. 2405 2406 // Failed to CAS. 2407 slow_path = new RegionNode(3); 2408 Node *slow_mem = new PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM); 2409 2410 slow_path->init_req(1, not_biased_ctrl); // Capture slow-control 2411 slow_mem->init_req(1, proj); 2412 2413 // Call CAS-based locking scheme (FastLock node). 2414 2415 transform_later(fast_lock_region); 2416 transform_later(fast_lock_mem_phi); 2417 2418 // Get slow path - FastLock failed to lock the object. 2419 ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0); 2420 mem_phi->init_req(2, fast_lock_mem_phi); 2421 // region->in(2) is set to fast path - the object is locked to the current thread. 2422 2423 slow_path->init_req(2, ctrl); // Capture slow-control 2424 slow_mem->init_req(2, fast_lock_mem_phi); 2425 2426 transform_later(slow_path); 2427 transform_later(slow_mem); 2428 // Reset lock's memory edge. 2429 lock->set_req(TypeFunc::Memory, slow_mem); 2430 2431 } else { 2432 region = new RegionNode(3); 2433 // create a Phi for the memory state 2434 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); 2435 2436 // Optimize test; set region slot 2 2437 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0); 2438 mem_phi->init_req(2, mem); 2439 } 2440 2441 // Make slow path call 2442 CallNode *call = make_slow_call((CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), 2443 OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, 2444 obj, box, NULL); 2445 2446 extract_call_projections(call); 2447 2448 // Slow path can only throw asynchronous exceptions, which are always 2449 // de-opted. So the compiler thinks the slow-call can never throw an 2450 // exception. If it DOES throw an exception we would need the debug 2451 // info removed first (since if it throws there is no monitor). 2452 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL && 2453 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock"); 2454 2455 // Capture slow path 2456 // disconnect fall-through projection from call and create a new one 2457 // hook up users of fall-through projection to region 2458 Node *slow_ctrl = _fallthroughproj->clone(); 2459 transform_later(slow_ctrl); 2460 _igvn.hash_delete(_fallthroughproj); 2461 _fallthroughproj->disconnect_inputs(NULL, C); 2462 region->init_req(1, slow_ctrl); 2463 // region inputs are now complete 2464 transform_later(region); 2465 _igvn.replace_node(_fallthroughproj, region); 2466 2467 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory)); 2468 mem_phi->init_req(1, memproj ); 2469 transform_later(mem_phi); 2470 _igvn.replace_node(_memproj_fallthrough, mem_phi); 2471 } 2472 2473 //------------------------------expand_unlock_node---------------------- 2474 void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) { 2475 2476 Node* ctrl = unlock->in(TypeFunc::Control); 2477 Node* mem = unlock->in(TypeFunc::Memory); 2478 Node* obj = unlock->obj_node(); 2479 Node* box = unlock->box_node(); 2480 2481 assert(!box->as_BoxLock()->is_eliminated(), "sanity"); 2482 2483 // No need for a null check on unlock 2484 2485 // Make the merge point 2486 Node *region; 2487 Node *mem_phi; 2488 2489 if (UseOptoBiasInlining) { 2490 // Check for biased locking unlock case, which is a no-op. 2491 // See the full description in MacroAssembler::biased_locking_exit(). 2492 region = new RegionNode(4); 2493 // create a Phi for the memory state 2494 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); 2495 mem_phi->init_req(3, mem); 2496 2497 Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type()); 2498 ctrl = opt_bits_test(ctrl, region, 3, mark_node, 2499 markWord::biased_lock_mask_in_place, 2500 markWord::biased_lock_pattern); 2501 } else { 2502 region = new RegionNode(3); 2503 // create a Phi for the memory state 2504 mem_phi = new PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); 2505 } 2506 2507 FastUnlockNode *funlock = new FastUnlockNode( ctrl, obj, box ); 2508 funlock = transform_later( funlock )->as_FastUnlock(); 2509 // Optimize test; set region slot 2 2510 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0); 2511 Node *thread = transform_later(new ThreadLocalNode()); 2512 2513 CallNode *call = make_slow_call((CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(), 2514 CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C), 2515 "complete_monitor_unlocking_C", slow_path, obj, box, thread); 2516 2517 extract_call_projections(call); 2518 2519 assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL && 2520 _memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock"); 2521 2522 // No exceptions for unlocking 2523 // Capture slow path 2524 // disconnect fall-through projection from call and create a new one 2525 // hook up users of fall-through projection to region 2526 Node *slow_ctrl = _fallthroughproj->clone(); 2527 transform_later(slow_ctrl); 2528 _igvn.hash_delete(_fallthroughproj); 2529 _fallthroughproj->disconnect_inputs(NULL, C); 2530 region->init_req(1, slow_ctrl); 2531 // region inputs are now complete 2532 transform_later(region); 2533 _igvn.replace_node(_fallthroughproj, region); 2534 2535 Node *memproj = transform_later(new ProjNode(call, TypeFunc::Memory) ); 2536 mem_phi->init_req(1, memproj ); 2537 mem_phi->init_req(2, mem); 2538 transform_later(mem_phi); 2539 _igvn.replace_node(_memproj_fallthrough, mem_phi); 2540 } 2541 2542 void PhaseMacroExpand::expand_subtypecheck_node(SubTypeCheckNode *check) { 2543 assert(check->in(SubTypeCheckNode::Control) == NULL, "should be pinned"); 2544 Node* bol = check->unique_out(); 2545 Node* obj_or_subklass = check->in(SubTypeCheckNode::ObjOrSubKlass); 2546 Node* superklass = check->in(SubTypeCheckNode::SuperKlass); 2547 assert(bol->is_Bool() && bol->as_Bool()->_test._test == BoolTest::ne, "unexpected bool node"); 2548 2549 for (DUIterator_Last imin, i = bol->last_outs(imin); i >= imin; --i) { 2550 Node* iff = bol->last_out(i); 2551 assert(iff->is_If(), "where's the if?"); 2552 2553 if (iff->in(0)->is_top()) { 2554 _igvn.replace_input_of(iff, 1, C->top()); 2555 continue; 2556 } 2557 2558 Node* iftrue = iff->as_If()->proj_out(1); 2559 Node* iffalse = iff->as_If()->proj_out(0); 2560 Node* ctrl = iff->in(0); 2561 2562 Node* subklass = NULL; 2563 if (_igvn.type(obj_or_subklass)->isa_klassptr()) { 2564 subklass = obj_or_subklass; 2565 } else { 2566 Node* k_adr = basic_plus_adr(obj_or_subklass, oopDesc::klass_offset_in_bytes()); 2567 subklass = _igvn.transform(LoadKlassNode::make(_igvn, NULL, C->immutable_memory(), k_adr, TypeInstPtr::KLASS)); 2568 } 2569 2570 Node* not_subtype_ctrl = Phase::gen_subtype_check(subklass, superklass, &ctrl, NULL, _igvn); 2571 2572 _igvn.replace_input_of(iff, 0, C->top()); 2573 _igvn.replace_node(iftrue, not_subtype_ctrl); 2574 _igvn.replace_node(iffalse, ctrl); 2575 } 2576 _igvn.replace_node(check, C->top()); 2577 } 2578 2579 //---------------------------eliminate_macro_nodes---------------------- 2580 // Eliminate scalar replaced allocations and associated locks. 2581 void PhaseMacroExpand::eliminate_macro_nodes() { 2582 if (C->macro_count() == 0) 2583 return; 2584 2585 // First, attempt to eliminate locks 2586 int cnt = C->macro_count(); 2587 for (int i=0; i < cnt; i++) { 2588 Node *n = C->macro_node(i); 2589 if (n->is_AbstractLock()) { // Lock and Unlock nodes 2590 // Before elimination mark all associated (same box and obj) 2591 // lock and unlock nodes. 2592 mark_eliminated_locking_nodes(n->as_AbstractLock()); 2593 } 2594 } 2595 bool progress = true; 2596 while (progress) { 2597 progress = false; 2598 for (int i = C->macro_count(); i > 0; i--) { 2599 Node * n = C->macro_node(i-1); 2600 bool success = false; 2601 debug_only(int old_macro_count = C->macro_count();); 2602 if (n->is_AbstractLock()) { 2603 success = eliminate_locking_node(n->as_AbstractLock()); 2604 } 2605 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count"); 2606 progress = progress || success; 2607 } 2608 } 2609 // Next, attempt to eliminate allocations 2610 _has_locks = false; 2611 progress = true; 2612 while (progress) { 2613 progress = false; 2614 for (int i = C->macro_count(); i > 0; i--) { 2615 Node * n = C->macro_node(i-1); 2616 bool success = false; 2617 debug_only(int old_macro_count = C->macro_count();); 2618 switch (n->class_id()) { 2619 case Node::Class_Allocate: 2620 case Node::Class_AllocateArray: 2621 success = eliminate_allocate_node(n->as_Allocate()); 2622 break; 2623 case Node::Class_CallStaticJava: 2624 success = eliminate_boxing_node(n->as_CallStaticJava()); 2625 break; 2626 case Node::Class_Lock: 2627 case Node::Class_Unlock: 2628 assert(!n->as_AbstractLock()->is_eliminated(), "sanity"); 2629 _has_locks = true; 2630 break; 2631 case Node::Class_ArrayCopy: 2632 break; 2633 case Node::Class_OuterStripMinedLoop: 2634 break; 2635 case Node::Class_SubTypeCheck: 2636 break; 2637 default: 2638 assert(n->Opcode() == Op_LoopLimit || 2639 n->Opcode() == Op_Opaque1 || 2640 n->Opcode() == Op_Opaque2 || 2641 n->Opcode() == Op_Opaque3 || 2642 BarrierSet::barrier_set()->barrier_set_c2()->is_gc_barrier_node(n), 2643 "unknown node type in macro list"); 2644 } 2645 assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count"); 2646 progress = progress || success; 2647 } 2648 } 2649 } 2650 2651 //------------------------------expand_macro_nodes---------------------- 2652 // Returns true if a failure occurred. 2653 bool PhaseMacroExpand::expand_macro_nodes() { 2654 // Last attempt to eliminate macro nodes. 2655 eliminate_macro_nodes(); 2656 2657 // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations. 2658 bool progress = true; 2659 while (progress) { 2660 progress = false; 2661 for (int i = C->macro_count(); i > 0; i--) { 2662 Node* n = C->macro_node(i-1); 2663 bool success = false; 2664 debug_only(int old_macro_count = C->macro_count();); 2665 if (n->Opcode() == Op_LoopLimit) { 2666 // Remove it from macro list and put on IGVN worklist to optimize. 2667 C->remove_macro_node(n); 2668 _igvn._worklist.push(n); 2669 success = true; 2670 } else if (n->Opcode() == Op_CallStaticJava) { 2671 // Remove it from macro list and put on IGVN worklist to optimize. 2672 C->remove_macro_node(n); 2673 _igvn._worklist.push(n); 2674 success = true; 2675 } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) { 2676 _igvn.replace_node(n, n->in(1)); 2677 success = true; 2678 #if INCLUDE_RTM_OPT 2679 } else if ((n->Opcode() == Op_Opaque3) && ((Opaque3Node*)n)->rtm_opt()) { 2680 assert(C->profile_rtm(), "should be used only in rtm deoptimization code"); 2681 assert((n->outcnt() == 1) && n->unique_out()->is_Cmp(), ""); 2682 Node* cmp = n->unique_out(); 2683 #ifdef ASSERT 2684 // Validate graph. 2685 assert((cmp->outcnt() == 1) && cmp->unique_out()->is_Bool(), ""); 2686 BoolNode* bol = cmp->unique_out()->as_Bool(); 2687 assert((bol->outcnt() == 1) && bol->unique_out()->is_If() && 2688 (bol->_test._test == BoolTest::ne), ""); 2689 IfNode* ifn = bol->unique_out()->as_If(); 2690 assert((ifn->outcnt() == 2) && 2691 ifn->proj_out(1)->is_uncommon_trap_proj(Deoptimization::Reason_rtm_state_change) != NULL, ""); 2692 #endif 2693 Node* repl = n->in(1); 2694 if (!_has_locks) { 2695 // Remove RTM state check if there are no locks in the code. 2696 // Replace input to compare the same value. 2697 repl = (cmp->in(1) == n) ? cmp->in(2) : cmp->in(1); 2698 } 2699 _igvn.replace_node(n, repl); 2700 success = true; 2701 #endif 2702 } else if (n->Opcode() == Op_OuterStripMinedLoop) { 2703 n->as_OuterStripMinedLoop()->adjust_strip_mined_loop(&_igvn); 2704 C->remove_macro_node(n); 2705 success = true; 2706 } 2707 assert(!success || (C->macro_count() == (old_macro_count - 1)), "elimination must have deleted one node from macro list"); 2708 progress = progress || success; 2709 } 2710 } 2711 2712 // Clean up the graph so we're less likely to hit the maximum node 2713 // limit 2714 _igvn.set_delay_transform(false); 2715 _igvn.optimize(); 2716 if (C->failing()) return true; 2717 _igvn.set_delay_transform(true); 2718 2719 2720 // Because we run IGVN after each expansion, some macro nodes may go 2721 // dead and be removed from the list as we iterate over it. Move 2722 // Allocate nodes (processed in a second pass) at the beginning of 2723 // the list and then iterate from the last element of the list until 2724 // an Allocate node is seen. This is robust to random deletion in 2725 // the list due to nodes going dead. 2726 C->sort_macro_nodes(); 2727 2728 // expand arraycopy "macro" nodes first 2729 // For ReduceBulkZeroing, we must first process all arraycopy nodes 2730 // before the allocate nodes are expanded. 2731 while (C->macro_count() > 0) { 2732 int macro_count = C->macro_count(); 2733 Node * n = C->macro_node(macro_count-1); 2734 assert(n->is_macro(), "only macro nodes expected here"); 2735 if (_igvn.type(n) == Type::TOP || (n->in(0) != NULL && n->in(0)->is_top())) { 2736 // node is unreachable, so don't try to expand it 2737 C->remove_macro_node(n); 2738 continue; 2739 } 2740 if (n->is_Allocate()) { 2741 break; 2742 } 2743 // Make sure expansion will not cause node limit to be exceeded. 2744 // Worst case is a macro node gets expanded into about 200 nodes. 2745 // Allow 50% more for optimization. 2746 if (C->check_node_count(300, "out of nodes before macro expansion")) { 2747 return true; 2748 } 2749 2750 debug_only(int old_macro_count = C->macro_count();); 2751 switch (n->class_id()) { 2752 case Node::Class_Lock: 2753 expand_lock_node(n->as_Lock()); 2754 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list"); 2755 break; 2756 case Node::Class_Unlock: 2757 expand_unlock_node(n->as_Unlock()); 2758 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list"); 2759 break; 2760 case Node::Class_ArrayCopy: 2761 expand_arraycopy_node(n->as_ArrayCopy()); 2762 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list"); 2763 break; 2764 case Node::Class_SubTypeCheck: 2765 expand_subtypecheck_node(n->as_SubTypeCheck()); 2766 assert(C->macro_count() == (old_macro_count - 1), "expansion must have deleted one node from macro list"); 2767 break; 2768 default: 2769 assert(false, "unknown node type in macro list"); 2770 } 2771 assert(C->macro_count() < macro_count, "must have deleted a node from macro list"); 2772 if (C->failing()) return true; 2773 2774 // Clean up the graph so we're less likely to hit the maximum node 2775 // limit 2776 _igvn.set_delay_transform(false); 2777 _igvn.optimize(); 2778 if (C->failing()) return true; 2779 _igvn.set_delay_transform(true); 2780 } 2781 2782 // All nodes except Allocate nodes are expanded now. There could be 2783 // new optimization opportunities (such as folding newly created 2784 // load from a just allocated object). Run IGVN. 2785 2786 // expand "macro" nodes 2787 // nodes are removed from the macro list as they are processed 2788 while (C->macro_count() > 0) { 2789 int macro_count = C->macro_count(); 2790 Node * n = C->macro_node(macro_count-1); 2791 assert(n->is_macro(), "only macro nodes expected here"); 2792 if (_igvn.type(n) == Type::TOP || (n->in(0) != NULL && n->in(0)->is_top())) { 2793 // node is unreachable, so don't try to expand it 2794 C->remove_macro_node(n); 2795 continue; 2796 } 2797 // Make sure expansion will not cause node limit to be exceeded. 2798 // Worst case is a macro node gets expanded into about 200 nodes. 2799 // Allow 50% more for optimization. 2800 if (C->check_node_count(300, "out of nodes before macro expansion")) { 2801 return true; 2802 } 2803 switch (n->class_id()) { 2804 case Node::Class_Allocate: 2805 expand_allocate(n->as_Allocate()); 2806 break; 2807 case Node::Class_AllocateArray: 2808 expand_allocate_array(n->as_AllocateArray()); 2809 break; 2810 default: 2811 assert(false, "unknown node type in macro list"); 2812 } 2813 assert(C->macro_count() < macro_count, "must have deleted a node from macro list"); 2814 if (C->failing()) return true; 2815 2816 // Clean up the graph so we're less likely to hit the maximum node 2817 // limit 2818 _igvn.set_delay_transform(false); 2819 _igvn.optimize(); 2820 if (C->failing()) return true; 2821 _igvn.set_delay_transform(true); 2822 } 2823 2824 _igvn.set_delay_transform(false); 2825 return false; 2826 }