1 /* 2 * Copyright (c) 2018, 2021, Red Hat, Inc. 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 "classfile/javaClasses.hpp" 27 #include "gc/shared/barrierSet.hpp" 28 #include "gc/shenandoah/shenandoahBarrierSet.hpp" 29 #include "gc/shenandoah/shenandoahForwarding.hpp" 30 #include "gc/shenandoah/shenandoahHeap.hpp" 31 #include "gc/shenandoah/shenandoahRuntime.hpp" 32 #include "gc/shenandoah/shenandoahThreadLocalData.hpp" 33 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp" 34 #include "gc/shenandoah/c2/shenandoahSupport.hpp" 35 #include "gc/shenandoah/heuristics/shenandoahHeuristics.hpp" 36 #include "opto/arraycopynode.hpp" 37 #include "opto/escape.hpp" 38 #include "opto/graphKit.hpp" 39 #include "opto/idealKit.hpp" 40 #include "opto/macro.hpp" 41 #include "opto/movenode.hpp" 42 #include "opto/narrowptrnode.hpp" 43 #include "opto/rootnode.hpp" 44 #include "opto/runtime.hpp" 45 46 ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() { 47 return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2()); 48 } 49 50 ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena) 51 : _iu_barriers(new (comp_arena) GrowableArray<ShenandoahIUBarrierNode*>(comp_arena, 8, 0, NULL)), 52 _load_reference_barriers(new (comp_arena) GrowableArray<ShenandoahLoadReferenceBarrierNode*>(comp_arena, 8, 0, NULL)) { 53 } 54 55 int ShenandoahBarrierSetC2State::iu_barriers_count() const { 56 return _iu_barriers->length(); 57 } 58 59 ShenandoahIUBarrierNode* ShenandoahBarrierSetC2State::iu_barrier(int idx) const { 60 return _iu_barriers->at(idx); 61 } 62 63 void ShenandoahBarrierSetC2State::add_iu_barrier(ShenandoahIUBarrierNode* n) { 64 assert(!_iu_barriers->contains(n), "duplicate entry in barrier list"); 65 _iu_barriers->append(n); 66 } 67 68 void ShenandoahBarrierSetC2State::remove_iu_barrier(ShenandoahIUBarrierNode* n) { 69 _iu_barriers->remove_if_existing(n); 70 } 71 72 int ShenandoahBarrierSetC2State::load_reference_barriers_count() const { 73 return _load_reference_barriers->length(); 74 } 75 76 ShenandoahLoadReferenceBarrierNode* ShenandoahBarrierSetC2State::load_reference_barrier(int idx) const { 77 return _load_reference_barriers->at(idx); 78 } 79 80 void ShenandoahBarrierSetC2State::add_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) { 81 assert(!_load_reference_barriers->contains(n), "duplicate entry in barrier list"); 82 _load_reference_barriers->append(n); 83 } 84 85 void ShenandoahBarrierSetC2State::remove_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) { 86 if (_load_reference_barriers->contains(n)) { 87 _load_reference_barriers->remove(n); 88 } 89 } 90 91 Node* ShenandoahBarrierSetC2::shenandoah_iu_barrier(GraphKit* kit, Node* obj) const { 92 if (ShenandoahIUBarrier) { 93 return kit->gvn().transform(new ShenandoahIUBarrierNode(obj)); 94 } 95 return obj; 96 } 97 98 #define __ kit-> 99 100 bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr, 101 BasicType bt, uint adr_idx) const { 102 intptr_t offset = 0; 103 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); 104 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase); 105 106 if (offset == Type::OffsetBot) { 107 return false; // cannot unalias unless there are precise offsets 108 } 109 110 if (alloc == NULL) { 111 return false; // No allocation found 112 } 113 114 intptr_t size_in_bytes = type2aelembytes(bt); 115 116 Node* mem = __ memory(adr_idx); // start searching here... 117 118 for (int cnt = 0; cnt < 50; cnt++) { 119 120 if (mem->is_Store()) { 121 122 Node* st_adr = mem->in(MemNode::Address); 123 intptr_t st_offset = 0; 124 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset); 125 126 if (st_base == NULL) { 127 break; // inscrutable pointer 128 } 129 130 // Break we have found a store with same base and offset as ours so break 131 if (st_base == base && st_offset == offset) { 132 break; 133 } 134 135 if (st_offset != offset && st_offset != Type::OffsetBot) { 136 const int MAX_STORE = BytesPerLong; 137 if (st_offset >= offset + size_in_bytes || 138 st_offset <= offset - MAX_STORE || 139 st_offset <= offset - mem->as_Store()->memory_size()) { 140 // Success: The offsets are provably independent. 141 // (You may ask, why not just test st_offset != offset and be done? 142 // The answer is that stores of different sizes can co-exist 143 // in the same sequence of RawMem effects. We sometimes initialize 144 // a whole 'tile' of array elements with a single jint or jlong.) 145 mem = mem->in(MemNode::Memory); 146 continue; // advance through independent store memory 147 } 148 } 149 150 if (st_base != base 151 && MemNode::detect_ptr_independence(base, alloc, st_base, 152 AllocateNode::Ideal_allocation(st_base, phase), 153 phase)) { 154 // Success: The bases are provably independent. 155 mem = mem->in(MemNode::Memory); 156 continue; // advance through independent store memory 157 } 158 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) { 159 160 InitializeNode* st_init = mem->in(0)->as_Initialize(); 161 AllocateNode* st_alloc = st_init->allocation(); 162 163 // Make sure that we are looking at the same allocation site. 164 // The alloc variable is guaranteed to not be null here from earlier check. 165 if (alloc == st_alloc) { 166 // Check that the initialization is storing NULL so that no previous store 167 // has been moved up and directly write a reference 168 Node* captured_store = st_init->find_captured_store(offset, 169 type2aelembytes(T_OBJECT), 170 phase); 171 if (captured_store == NULL || captured_store == st_init->zero_memory()) { 172 return true; 173 } 174 } 175 } 176 177 // Unless there is an explicit 'continue', we must bail out here, 178 // because 'mem' is an inscrutable memory state (e.g., a call). 179 break; 180 } 181 182 return false; 183 } 184 185 #undef __ 186 #define __ ideal. 187 188 void ShenandoahBarrierSetC2::satb_write_barrier_pre(GraphKit* kit, 189 bool do_load, 190 Node* obj, 191 Node* adr, 192 uint alias_idx, 193 Node* val, 194 const TypeOopPtr* val_type, 195 Node* pre_val, 196 BasicType bt) const { 197 // Some sanity checks 198 // Note: val is unused in this routine. 199 200 if (do_load) { 201 // We need to generate the load of the previous value 202 assert(obj != NULL, "must have a base"); 203 assert(adr != NULL, "where are loading from?"); 204 assert(pre_val == NULL, "loaded already?"); 205 assert(val_type != NULL, "need a type"); 206 207 if (ReduceInitialCardMarks 208 && satb_can_remove_pre_barrier(kit, &kit->gvn(), adr, bt, alias_idx)) { 209 return; 210 } 211 212 } else { 213 // In this case both val_type and alias_idx are unused. 214 assert(pre_val != NULL, "must be loaded already"); 215 // Nothing to be done if pre_val is null. 216 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return; 217 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here"); 218 } 219 assert(bt == T_OBJECT, "or we shouldn't be here"); 220 221 IdealKit ideal(kit, true); 222 223 Node* tls = __ thread(); // ThreadLocalStorage 224 225 Node* no_base = __ top(); 226 Node* zero = __ ConI(0); 227 Node* zeroX = __ ConX(0); 228 229 float likely = PROB_LIKELY(0.999); 230 float unlikely = PROB_UNLIKELY(0.999); 231 232 // Offsets into the thread 233 const int index_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()); 234 const int buffer_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()); 235 236 // Now the actual pointers into the thread 237 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset)); 238 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset)); 239 240 // Now some of the values 241 Node* marking; 242 Node* gc_state = __ AddP(no_base, tls, __ ConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset()))); 243 Node* ld = __ load(__ ctrl(), gc_state, TypeInt::BYTE, T_BYTE, Compile::AliasIdxRaw); 244 marking = __ AndI(ld, __ ConI(ShenandoahHeap::MARKING)); 245 assert(ShenandoahBarrierC2Support::is_gc_state_load(ld), "Should match the shape"); 246 247 // if (!marking) 248 __ if_then(marking, BoolTest::ne, zero, unlikely); { 249 BasicType index_bt = TypeX_X->basic_type(); 250 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading Shenandoah SATBMarkQueue::_index with wrong size."); 251 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw); 252 253 if (do_load) { 254 // load original value 255 // alias_idx correct?? 256 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx); 257 } 258 259 // if (pre_val != NULL) 260 __ if_then(pre_val, BoolTest::ne, kit->null()); { 261 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); 262 263 // is the queue for this thread full? 264 __ if_then(index, BoolTest::ne, zeroX, likely); { 265 266 // decrement the index 267 Node* next_index = kit->gvn().transform(new SubXNode(index, __ ConX(sizeof(intptr_t)))); 268 269 // Now get the buffer location we will log the previous value into and store it 270 Node *log_addr = __ AddP(no_base, buffer, next_index); 271 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered); 272 // update the index 273 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered); 274 275 } __ else_(); { 276 277 // logging buffer is full, call the runtime 278 const TypeFunc *tf = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type(); 279 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), "shenandoah_wb_pre", pre_val, tls); 280 } __ end_if(); // (!index) 281 } __ end_if(); // (pre_val != NULL) 282 } __ end_if(); // (!marking) 283 284 // Final sync IdealKit and GraphKit. 285 kit->final_sync(ideal); 286 287 if (ShenandoahSATBBarrier && adr != NULL) { 288 Node* c = kit->control(); 289 Node* call = c->in(1)->in(1)->in(1)->in(0); 290 assert(is_shenandoah_wb_pre_call(call), "shenandoah_wb_pre call expected"); 291 call->add_req(adr); 292 } 293 } 294 295 bool ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(Node* call) { 296 return call->is_CallLeaf() && 297 call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry); 298 } 299 300 bool ShenandoahBarrierSetC2::is_shenandoah_lrb_call(Node* call) { 301 if (!call->is_CallLeaf()) { 302 return false; 303 } 304 305 address entry_point = call->as_CallLeaf()->entry_point(); 306 return (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_strong)) || 307 (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_strong_narrow)) || 308 (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_weak)) || 309 (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_weak_narrow)) || 310 (entry_point == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_phantom)); 311 } 312 313 bool ShenandoahBarrierSetC2::is_shenandoah_marking_if(PhaseTransform *phase, Node* n) { 314 if (n->Opcode() != Op_If) { 315 return false; 316 } 317 318 Node* bol = n->in(1); 319 assert(bol->is_Bool(), ""); 320 Node* cmpx = bol->in(1); 321 if (bol->as_Bool()->_test._test == BoolTest::ne && 322 cmpx->is_Cmp() && cmpx->in(2) == phase->intcon(0) && 323 is_shenandoah_state_load(cmpx->in(1)->in(1)) && 324 cmpx->in(1)->in(2)->is_Con() && 325 cmpx->in(1)->in(2) == phase->intcon(ShenandoahHeap::MARKING)) { 326 return true; 327 } 328 329 return false; 330 } 331 332 bool ShenandoahBarrierSetC2::is_shenandoah_state_load(Node* n) { 333 if (!n->is_Load()) return false; 334 const int state_offset = in_bytes(ShenandoahThreadLocalData::gc_state_offset()); 335 return n->in(2)->is_AddP() && n->in(2)->in(2)->Opcode() == Op_ThreadLocal 336 && n->in(2)->in(3)->is_Con() 337 && n->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == state_offset; 338 } 339 340 void ShenandoahBarrierSetC2::shenandoah_write_barrier_pre(GraphKit* kit, 341 bool do_load, 342 Node* obj, 343 Node* adr, 344 uint alias_idx, 345 Node* val, 346 const TypeOopPtr* val_type, 347 Node* pre_val, 348 BasicType bt) const { 349 if (ShenandoahSATBBarrier) { 350 IdealKit ideal(kit); 351 kit->sync_kit(ideal); 352 353 satb_write_barrier_pre(kit, do_load, obj, adr, alias_idx, val, val_type, pre_val, bt); 354 355 ideal.sync_kit(kit); 356 kit->final_sync(ideal); 357 } 358 } 359 360 // Helper that guards and inserts a pre-barrier. 361 void ShenandoahBarrierSetC2::insert_pre_barrier(GraphKit* kit, Node* base_oop, Node* offset, 362 Node* pre_val, bool need_mem_bar) const { 363 // We could be accessing the referent field of a reference object. If so, when Shenandoah 364 // is enabled, we need to log the value in the referent field in an SATB buffer. 365 // This routine performs some compile time filters and generates suitable 366 // runtime filters that guard the pre-barrier code. 367 // Also add memory barrier for non volatile load from the referent field 368 // to prevent commoning of loads across safepoint. 369 370 // Some compile time checks. 371 372 // If offset is a constant, is it java_lang_ref_Reference::_reference_offset? 373 const TypeX* otype = offset->find_intptr_t_type(); 374 if (otype != NULL && otype->is_con() && 375 otype->get_con() != java_lang_ref_Reference::referent_offset()) { 376 // Constant offset but not the reference_offset so just return 377 return; 378 } 379 380 // We only need to generate the runtime guards for instances. 381 const TypeOopPtr* btype = base_oop->bottom_type()->isa_oopptr(); 382 if (btype != NULL) { 383 if (btype->isa_aryptr()) { 384 // Array type so nothing to do 385 return; 386 } 387 388 const TypeInstPtr* itype = btype->isa_instptr(); 389 if (itype != NULL) { 390 // Can the klass of base_oop be statically determined to be 391 // _not_ a sub-class of Reference and _not_ Object? 392 ciKlass* klass = itype->klass(); 393 if ( klass->is_loaded() && 394 !klass->is_subtype_of(kit->env()->Reference_klass()) && 395 !kit->env()->Object_klass()->is_subtype_of(klass)) { 396 return; 397 } 398 } 399 } 400 401 // The compile time filters did not reject base_oop/offset so 402 // we need to generate the following runtime filters 403 // 404 // if (offset == java_lang_ref_Reference::_reference_offset) { 405 // if (instance_of(base, java.lang.ref.Reference)) { 406 // pre_barrier(_, pre_val, ...); 407 // } 408 // } 409 410 float likely = PROB_LIKELY( 0.999); 411 float unlikely = PROB_UNLIKELY(0.999); 412 413 IdealKit ideal(kit); 414 415 Node* referent_off = __ ConX(java_lang_ref_Reference::referent_offset()); 416 417 __ if_then(offset, BoolTest::eq, referent_off, unlikely); { 418 // Update graphKit memory and control from IdealKit. 419 kit->sync_kit(ideal); 420 421 Node* ref_klass_con = kit->makecon(TypeKlassPtr::make(kit->env()->Reference_klass())); 422 Node* is_instof = kit->gen_instanceof(base_oop, ref_klass_con); 423 424 // Update IdealKit memory and control from graphKit. 425 __ sync_kit(kit); 426 427 Node* one = __ ConI(1); 428 // is_instof == 0 if base_oop == NULL 429 __ if_then(is_instof, BoolTest::eq, one, unlikely); { 430 431 // Update graphKit from IdeakKit. 432 kit->sync_kit(ideal); 433 434 // Use the pre-barrier to record the value in the referent field 435 satb_write_barrier_pre(kit, false /* do_load */, 436 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */, 437 pre_val /* pre_val */, 438 T_OBJECT); 439 if (need_mem_bar) { 440 // Add memory barrier to prevent commoning reads from this field 441 // across safepoint since GC can change its value. 442 kit->insert_mem_bar(Op_MemBarCPUOrder); 443 } 444 // Update IdealKit from graphKit. 445 __ sync_kit(kit); 446 447 } __ end_if(); // _ref_type != ref_none 448 } __ end_if(); // offset == referent_offset 449 450 // Final sync IdealKit and GraphKit. 451 kit->final_sync(ideal); 452 } 453 454 #undef __ 455 456 const TypeFunc* ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type() { 457 const Type **fields = TypeTuple::fields(2); 458 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value 459 fields[TypeFunc::Parms+1] = TypeRawPtr::NOTNULL; // thread 460 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields); 461 462 // create result type (range) 463 fields = TypeTuple::fields(0); 464 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields); 465 466 return TypeFunc::make(domain, range); 467 } 468 469 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type() { 470 const Type **fields = TypeTuple::fields(1); 471 fields[TypeFunc::Parms+0] = TypeOopPtr::NOTNULL; // src oop 472 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields); 473 474 // create result type (range) 475 fields = TypeTuple::fields(0); 476 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields); 477 478 return TypeFunc::make(domain, range); 479 } 480 481 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_load_reference_barrier_Type() { 482 const Type **fields = TypeTuple::fields(2); 483 fields[TypeFunc::Parms+0] = TypeOopPtr::BOTTOM; // original field value 484 fields[TypeFunc::Parms+1] = TypeRawPtr::BOTTOM; // original load address 485 486 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields); 487 488 // create result type (range) 489 fields = TypeTuple::fields(1); 490 fields[TypeFunc::Parms+0] = TypeOopPtr::BOTTOM; 491 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields); 492 493 return TypeFunc::make(domain, range); 494 } 495 496 Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const { 497 DecoratorSet decorators = access.decorators(); 498 499 const TypePtr* adr_type = access.addr().type(); 500 Node* adr = access.addr().node(); 501 502 bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0; 503 bool on_heap = (decorators & IN_HEAP) != 0; 504 505 if (!access.is_oop() || (!on_heap && !anonymous)) { 506 return BarrierSetC2::store_at_resolved(access, val); 507 } 508 509 if (access.is_parse_access()) { 510 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access); 511 GraphKit* kit = parse_access.kit(); 512 513 uint adr_idx = kit->C->get_alias_index(adr_type); 514 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); 515 Node* value = val.node(); 516 value = shenandoah_iu_barrier(kit, value); 517 val.set_node(value); 518 shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(), 519 static_cast<const TypeOopPtr*>(val.type()), NULL /* pre_val */, access.type()); 520 } else { 521 assert(access.is_opt_access(), "only for optimization passes"); 522 assert(((decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0 || !ShenandoahSATBBarrier) && (decorators & C2_ARRAY_COPY) != 0, "unexpected caller of this code"); 523 C2OptAccess& opt_access = static_cast<C2OptAccess&>(access); 524 PhaseGVN& gvn = opt_access.gvn(); 525 526 if (ShenandoahIUBarrier) { 527 Node* enqueue = gvn.transform(new ShenandoahIUBarrierNode(val.node())); 528 val.set_node(enqueue); 529 } 530 } 531 return BarrierSetC2::store_at_resolved(access, val); 532 } 533 534 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const { 535 // 1: non-reference load, no additional barrier is needed 536 if (!access.is_oop()) { 537 return BarrierSetC2::load_at_resolved(access, val_type);; 538 } 539 540 Node* load = BarrierSetC2::load_at_resolved(access, val_type); 541 DecoratorSet decorators = access.decorators(); 542 BasicType type = access.type(); 543 544 // 2: apply LRB if needed 545 if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) { 546 load = new ShenandoahLoadReferenceBarrierNode(NULL, load, decorators); 547 if (access.is_parse_access()) { 548 load = static_cast<C2ParseAccess &>(access).kit()->gvn().transform(load); 549 } else { 550 load = static_cast<C2OptAccess &>(access).gvn().transform(load); 551 } 552 } 553 554 // 3: apply keep-alive barrier for java.lang.ref.Reference if needed 555 if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) { 556 Node* top = Compile::current()->top(); 557 Node* adr = access.addr().node(); 558 Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : top; 559 Node* obj = access.base(); 560 561 bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0; 562 bool on_weak_ref = (decorators & (ON_WEAK_OOP_REF | ON_PHANTOM_OOP_REF)) != 0; 563 bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0; 564 565 // If we are reading the value of the referent field of a Reference 566 // object (either by using Unsafe directly or through reflection) 567 // then, if SATB is enabled, we need to record the referent in an 568 // SATB log buffer using the pre-barrier mechanism. 569 // Also we need to add memory barrier to prevent commoning reads 570 // from this field across safepoint since GC can change its value. 571 if (!on_weak_ref || (unknown && (offset == top || obj == top)) || !keep_alive) { 572 return load; 573 } 574 575 assert(access.is_parse_access(), "entry not supported at optimization time"); 576 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access); 577 GraphKit* kit = parse_access.kit(); 578 bool mismatched = (decorators & C2_MISMATCHED) != 0; 579 bool is_unordered = (decorators & MO_UNORDERED) != 0; 580 bool in_native = (decorators & IN_NATIVE) != 0; 581 bool need_cpu_mem_bar = !is_unordered || mismatched || in_native; 582 583 if (on_weak_ref) { 584 // Use the pre-barrier to record the value in the referent field 585 satb_write_barrier_pre(kit, false /* do_load */, 586 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */, 587 load /* pre_val */, T_OBJECT); 588 // Add memory barrier to prevent commoning reads from this field 589 // across safepoint since GC can change its value. 590 kit->insert_mem_bar(Op_MemBarCPUOrder); 591 } else if (unknown) { 592 // We do not require a mem bar inside pre_barrier if need_mem_bar 593 // is set: the barriers would be emitted by us. 594 insert_pre_barrier(kit, obj, offset, load, !need_cpu_mem_bar); 595 } 596 } 597 598 return load; 599 } 600 601 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 602 Node* new_val, const Type* value_type) const { 603 GraphKit* kit = access.kit(); 604 if (access.is_oop()) { 605 new_val = shenandoah_iu_barrier(kit, new_val); 606 shenandoah_write_barrier_pre(kit, false /* do_load */, 607 NULL, NULL, max_juint, NULL, NULL, 608 expected_val /* pre_val */, T_OBJECT); 609 610 MemNode::MemOrd mo = access.mem_node_mo(); 611 Node* mem = access.memory(); 612 Node* adr = access.addr().node(); 613 const TypePtr* adr_type = access.addr().type(); 614 Node* load_store = NULL; 615 616 #ifdef _LP64 617 if (adr->bottom_type()->is_ptr_to_narrowoop()) { 618 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop())); 619 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop())); 620 if (ShenandoahCASBarrier) { 621 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo)); 622 } else { 623 load_store = kit->gvn().transform(new CompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo)); 624 } 625 } else 626 #endif 627 { 628 if (ShenandoahCASBarrier) { 629 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo)); 630 } else { 631 load_store = kit->gvn().transform(new CompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo)); 632 } 633 } 634 635 access.set_raw_access(load_store); 636 pin_atomic_op(access); 637 638 #ifdef _LP64 639 if (adr->bottom_type()->is_ptr_to_narrowoop()) { 640 load_store = kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type())); 641 } 642 #endif 643 load_store = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(NULL, load_store, access.decorators())); 644 return load_store; 645 } 646 return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type); 647 } 648 649 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 650 Node* new_val, const Type* value_type) const { 651 GraphKit* kit = access.kit(); 652 if (access.is_oop()) { 653 new_val = shenandoah_iu_barrier(kit, new_val); 654 shenandoah_write_barrier_pre(kit, false /* do_load */, 655 NULL, NULL, max_juint, NULL, NULL, 656 expected_val /* pre_val */, T_OBJECT); 657 DecoratorSet decorators = access.decorators(); 658 MemNode::MemOrd mo = access.mem_node_mo(); 659 Node* mem = access.memory(); 660 bool is_weak_cas = (decorators & C2_WEAK_CMPXCHG) != 0; 661 Node* load_store = NULL; 662 Node* adr = access.addr().node(); 663 #ifdef _LP64 664 if (adr->bottom_type()->is_ptr_to_narrowoop()) { 665 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop())); 666 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop())); 667 if (ShenandoahCASBarrier) { 668 if (is_weak_cas) { 669 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); 670 } else { 671 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); 672 } 673 } else { 674 if (is_weak_cas) { 675 load_store = kit->gvn().transform(new WeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); 676 } else { 677 load_store = kit->gvn().transform(new CompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); 678 } 679 } 680 } else 681 #endif 682 { 683 if (ShenandoahCASBarrier) { 684 if (is_weak_cas) { 685 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); 686 } else { 687 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); 688 } 689 } else { 690 if (is_weak_cas) { 691 load_store = kit->gvn().transform(new WeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); 692 } else { 693 load_store = kit->gvn().transform(new CompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); 694 } 695 } 696 } 697 access.set_raw_access(load_store); 698 pin_atomic_op(access); 699 return load_store; 700 } 701 return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type); 702 } 703 704 Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* val, const Type* value_type) const { 705 GraphKit* kit = access.kit(); 706 if (access.is_oop()) { 707 val = shenandoah_iu_barrier(kit, val); 708 } 709 Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type); 710 if (access.is_oop()) { 711 result = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(NULL, result, access.decorators())); 712 shenandoah_write_barrier_pre(kit, false /* do_load */, 713 NULL, NULL, max_juint, NULL, NULL, 714 result /* pre_val */, T_OBJECT); 715 } 716 return result; 717 } 718 719 // Support for GC barriers emitted during parsing 720 bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const { 721 if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier || node->Opcode() == Op_ShenandoahIUBarrier) return true; 722 if (node->Opcode() != Op_CallLeaf && node->Opcode() != Op_CallLeafNoFP) { 723 return false; 724 } 725 CallLeafNode *call = node->as_CallLeaf(); 726 if (call->_name == NULL) { 727 return false; 728 } 729 730 return strcmp(call->_name, "shenandoah_clone_barrier") == 0 || 731 strcmp(call->_name, "shenandoah_cas_obj") == 0 || 732 strcmp(call->_name, "shenandoah_wb_pre") == 0; 733 } 734 735 Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const { 736 if (c == NULL) { 737 return c; 738 } 739 if (c->Opcode() == Op_ShenandoahLoadReferenceBarrier) { 740 return c->in(ShenandoahLoadReferenceBarrierNode::ValueIn); 741 } 742 if (c->Opcode() == Op_ShenandoahIUBarrier) { 743 c = c->in(1); 744 } 745 return c; 746 } 747 748 bool ShenandoahBarrierSetC2::expand_barriers(Compile* C, PhaseIterGVN& igvn) const { 749 return !ShenandoahBarrierC2Support::expand(C, igvn); 750 } 751 752 bool ShenandoahBarrierSetC2::optimize_loops(PhaseIdealLoop* phase, LoopOptsMode mode, VectorSet& visited, Node_Stack& nstack, Node_List& worklist) const { 753 if (mode == LoopOptsShenandoahExpand) { 754 assert(UseShenandoahGC, "only for shenandoah"); 755 ShenandoahBarrierC2Support::pin_and_expand(phase); 756 return true; 757 } else if (mode == LoopOptsShenandoahPostExpand) { 758 assert(UseShenandoahGC, "only for shenandoah"); 759 visited.clear(); 760 ShenandoahBarrierC2Support::optimize_after_expansion(visited, nstack, worklist, phase); 761 return true; 762 } 763 return false; 764 } 765 766 bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, bool is_clone_instance, ArrayCopyPhase phase) const { 767 bool is_oop = is_reference_type(type); 768 if (!is_oop) { 769 return false; 770 } 771 if (ShenandoahSATBBarrier && tightly_coupled_alloc) { 772 if (phase == Optimization) { 773 return false; 774 } 775 return !is_clone; 776 } 777 if (phase == Optimization) { 778 return !ShenandoahIUBarrier; 779 } 780 return true; 781 } 782 783 bool ShenandoahBarrierSetC2::clone_needs_barrier(Node* src, PhaseGVN& gvn) { 784 const TypeOopPtr* src_type = gvn.type(src)->is_oopptr(); 785 if (src_type->isa_instptr() != NULL) { 786 ciInstanceKlass* ik = src_type->klass()->as_instance_klass(); 787 if ((src_type->klass_is_exact() || (!ik->is_interface() && !ik->has_subklass())) && !ik->has_injected_fields()) { 788 if (ik->has_object_fields()) { 789 return true; 790 } else { 791 if (!src_type->klass_is_exact()) { 792 Compile::current()->dependencies()->assert_leaf_type(ik); 793 } 794 } 795 } else { 796 return true; 797 } 798 } else if (src_type->isa_aryptr()) { 799 BasicType src_elem = src_type->klass()->as_array_klass()->element_type()->basic_type(); 800 if (is_reference_type(src_elem)) { 801 return true; 802 } 803 } else { 804 return true; 805 } 806 return false; 807 } 808 809 void ShenandoahBarrierSetC2::clone_at_expansion(PhaseMacroExpand* phase, ArrayCopyNode* ac) const { 810 Node* ctrl = ac->in(TypeFunc::Control); 811 Node* mem = ac->in(TypeFunc::Memory); 812 Node* src_base = ac->in(ArrayCopyNode::Src); 813 Node* src_offset = ac->in(ArrayCopyNode::SrcPos); 814 Node* dest_base = ac->in(ArrayCopyNode::Dest); 815 Node* dest_offset = ac->in(ArrayCopyNode::DestPos); 816 Node* length = ac->in(ArrayCopyNode::Length); 817 818 Node* src = phase->basic_plus_adr(src_base, src_offset); 819 Node* dest = phase->basic_plus_adr(dest_base, dest_offset); 820 821 if (ShenandoahCloneBarrier && clone_needs_barrier(src, phase->igvn())) { 822 // Check if heap is has forwarded objects. If it does, we need to call into the special 823 // routine that would fix up source references before we can continue. 824 825 enum { _heap_stable = 1, _heap_unstable, PATH_LIMIT }; 826 Node* region = new RegionNode(PATH_LIMIT); 827 Node* mem_phi = new PhiNode(region, Type::MEMORY, TypeRawPtr::BOTTOM); 828 829 Node* thread = phase->transform_later(new ThreadLocalNode()); 830 Node* offset = phase->igvn().MakeConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 831 Node* gc_state_addr = phase->transform_later(new AddPNode(phase->C->top(), thread, offset)); 832 833 uint gc_state_idx = Compile::AliasIdxRaw; 834 const TypePtr* gc_state_adr_type = NULL; // debug-mode-only argument 835 debug_only(gc_state_adr_type = phase->C->get_adr_type(gc_state_idx)); 836 837 Node* gc_state = phase->transform_later(new LoadBNode(ctrl, mem, gc_state_addr, gc_state_adr_type, TypeInt::BYTE, MemNode::unordered)); 838 int flags = ShenandoahHeap::HAS_FORWARDED; 839 if (ShenandoahIUBarrier) { 840 flags |= ShenandoahHeap::MARKING; 841 } 842 Node* stable_and = phase->transform_later(new AndINode(gc_state, phase->igvn().intcon(flags))); 843 Node* stable_cmp = phase->transform_later(new CmpINode(stable_and, phase->igvn().zerocon(T_INT))); 844 Node* stable_test = phase->transform_later(new BoolNode(stable_cmp, BoolTest::ne)); 845 846 IfNode* stable_iff = phase->transform_later(new IfNode(ctrl, stable_test, PROB_UNLIKELY(0.999), COUNT_UNKNOWN))->as_If(); 847 Node* stable_ctrl = phase->transform_later(new IfFalseNode(stable_iff)); 848 Node* unstable_ctrl = phase->transform_later(new IfTrueNode(stable_iff)); 849 850 // Heap is stable, no need to do anything additional 851 region->init_req(_heap_stable, stable_ctrl); 852 mem_phi->init_req(_heap_stable, mem); 853 854 // Heap is unstable, call into clone barrier stub 855 Node* call = phase->make_leaf_call(unstable_ctrl, mem, 856 ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type(), 857 CAST_FROM_FN_PTR(address, ShenandoahRuntime::shenandoah_clone_barrier), 858 "shenandoah_clone", 859 TypeRawPtr::BOTTOM, 860 src_base); 861 call = phase->transform_later(call); 862 863 ctrl = phase->transform_later(new ProjNode(call, TypeFunc::Control)); 864 mem = phase->transform_later(new ProjNode(call, TypeFunc::Memory)); 865 region->init_req(_heap_unstable, ctrl); 866 mem_phi->init_req(_heap_unstable, mem); 867 868 // Wire up the actual arraycopy stub now 869 ctrl = phase->transform_later(region); 870 mem = phase->transform_later(mem_phi); 871 872 const char* name = "arraycopy"; 873 call = phase->make_leaf_call(ctrl, mem, 874 OptoRuntime::fast_arraycopy_Type(), 875 phase->basictype2arraycopy(T_LONG, NULL, NULL, true, name, true), 876 name, TypeRawPtr::BOTTOM, 877 src, dest, length 878 LP64_ONLY(COMMA phase->top())); 879 call = phase->transform_later(call); 880 881 // Hook up the whole thing into the graph 882 phase->igvn().replace_node(ac, call); 883 } else { 884 BarrierSetC2::clone_at_expansion(phase, ac); 885 } 886 } 887 888 889 // Support for macro expanded GC barriers 890 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const { 891 if (node->Opcode() == Op_ShenandoahIUBarrier) { 892 state()->add_iu_barrier((ShenandoahIUBarrierNode*) node); 893 } 894 if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) { 895 state()->add_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node); 896 } 897 } 898 899 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const { 900 if (node->Opcode() == Op_ShenandoahIUBarrier) { 901 state()->remove_iu_barrier((ShenandoahIUBarrierNode*) node); 902 } 903 if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) { 904 state()->remove_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node); 905 } 906 } 907 908 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* n) const { 909 if (is_shenandoah_wb_pre_call(n)) { 910 shenandoah_eliminate_wb_pre(n, ¯o->igvn()); 911 } 912 } 913 914 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const { 915 assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), ""); 916 Node* c = call->as_Call()->proj_out(TypeFunc::Control); 917 c = c->unique_ctrl_out(); 918 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); 919 c = c->unique_ctrl_out(); 920 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); 921 Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0); 922 assert(iff->is_If(), "expect test"); 923 if (!is_shenandoah_marking_if(igvn, iff)) { 924 c = c->unique_ctrl_out(); 925 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); 926 iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0); 927 assert(is_shenandoah_marking_if(igvn, iff), "expect marking test"); 928 } 929 Node* cmpx = iff->in(1)->in(1); 930 igvn->replace_node(cmpx, igvn->makecon(TypeInt::CC_EQ)); 931 igvn->rehash_node_delayed(call); 932 call->del_req(call->req()-1); 933 } 934 935 void ShenandoahBarrierSetC2::enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const { 936 if (node->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(node)) { 937 igvn->add_users_to_worklist(node); 938 } 939 } 940 941 void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const { 942 for (uint i = 0; i < useful.size(); i++) { 943 Node* n = useful.at(i); 944 if (n->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(n)) { 945 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 946 C->record_for_igvn(n->fast_out(i)); 947 } 948 } 949 } 950 for (int i = state()->iu_barriers_count() - 1; i >= 0; i--) { 951 ShenandoahIUBarrierNode* n = state()->iu_barrier(i); 952 if (!useful.member(n)) { 953 state()->remove_iu_barrier(n); 954 } 955 } 956 for (int i = state()->load_reference_barriers_count() - 1; i >= 0; i--) { 957 ShenandoahLoadReferenceBarrierNode* n = state()->load_reference_barrier(i); 958 if (!useful.member(n)) { 959 state()->remove_load_reference_barrier(n); 960 } 961 } 962 } 963 964 void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const { 965 return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena); 966 } 967 968 ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const { 969 return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state()); 970 } 971 972 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be 973 // expanded later, then now is the time to do so. 974 bool ShenandoahBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { return false; } 975 976 #ifdef ASSERT 977 void ShenandoahBarrierSetC2::verify_gc_barriers(Compile* compile, CompilePhase phase) const { 978 if (ShenandoahVerifyOptoBarriers && phase == BarrierSetC2::BeforeMacroExpand) { 979 ShenandoahBarrierC2Support::verify(Compile::current()->root()); 980 } else if (phase == BarrierSetC2::BeforeCodeGen) { 981 // Verify Shenandoah pre-barriers 982 const int marking_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()); 983 984 Unique_Node_List visited; 985 Node_List worklist; 986 // We're going to walk control flow backwards starting from the Root 987 worklist.push(compile->root()); 988 while (worklist.size() > 0) { 989 Node *x = worklist.pop(); 990 if (x == NULL || x == compile->top()) continue; 991 if (visited.member(x)) { 992 continue; 993 } else { 994 visited.push(x); 995 } 996 997 if (x->is_Region()) { 998 for (uint i = 1; i < x->req(); i++) { 999 worklist.push(x->in(i)); 1000 } 1001 } else { 1002 worklist.push(x->in(0)); 1003 // We are looking for the pattern: 1004 // /->ThreadLocal 1005 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset) 1006 // \->ConI(0) 1007 // We want to verify that the If and the LoadB have the same control 1008 // See GraphKit::g1_write_barrier_pre() 1009 if (x->is_If()) { 1010 IfNode *iff = x->as_If(); 1011 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) { 1012 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp(); 1013 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0 1014 && cmp->in(1)->is_Load()) { 1015 LoadNode *load = cmp->in(1)->as_Load(); 1016 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal 1017 && load->in(2)->in(3)->is_Con() 1018 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) { 1019 1020 Node *if_ctrl = iff->in(0); 1021 Node *load_ctrl = load->in(0); 1022 1023 if (if_ctrl != load_ctrl) { 1024 // Skip possible CProj->NeverBranch in infinite loops 1025 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj) 1026 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) { 1027 if_ctrl = if_ctrl->in(0)->in(0); 1028 } 1029 } 1030 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match"); 1031 } 1032 } 1033 } 1034 } 1035 } 1036 } 1037 } 1038 } 1039 #endif 1040 1041 Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const { 1042 if (is_shenandoah_wb_pre_call(n)) { 1043 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt(); 1044 if (n->req() > cnt) { 1045 Node* addp = n->in(cnt); 1046 if (has_only_shenandoah_wb_pre_uses(addp)) { 1047 n->del_req(cnt); 1048 if (can_reshape) { 1049 phase->is_IterGVN()->_worklist.push(addp); 1050 } 1051 return n; 1052 } 1053 } 1054 } 1055 if (n->Opcode() == Op_CmpP) { 1056 Node* in1 = n->in(1); 1057 Node* in2 = n->in(2); 1058 1059 // If one input is NULL, then step over the strong LRB barriers on the other input 1060 if (in1->bottom_type() == TypePtr::NULL_PTR && 1061 !((in2->Opcode() == Op_ShenandoahLoadReferenceBarrier) && 1062 !ShenandoahBarrierSet::is_strong_access(((ShenandoahLoadReferenceBarrierNode*)in2)->decorators()))) { 1063 in2 = step_over_gc_barrier(in2); 1064 } 1065 if (in2->bottom_type() == TypePtr::NULL_PTR && 1066 !((in1->Opcode() == Op_ShenandoahLoadReferenceBarrier) && 1067 !ShenandoahBarrierSet::is_strong_access(((ShenandoahLoadReferenceBarrierNode*)in1)->decorators()))) { 1068 in1 = step_over_gc_barrier(in1); 1069 } 1070 1071 if (in1 != n->in(1)) { 1072 n->set_req_X(1, in1, phase); 1073 assert(in2 == n->in(2), "only one change"); 1074 return n; 1075 } 1076 if (in2 != n->in(2)) { 1077 n->set_req_X(2, in2, phase); 1078 return n; 1079 } 1080 } else if (can_reshape && 1081 n->Opcode() == Op_If && 1082 ShenandoahBarrierC2Support::is_heap_stable_test(n) && 1083 n->in(0) != NULL) { 1084 Node* dom = n->in(0); 1085 Node* prev_dom = n; 1086 int op = n->Opcode(); 1087 int dist = 16; 1088 // Search up the dominator tree for another heap stable test 1089 while (dom->Opcode() != op || // Not same opcode? 1090 !ShenandoahBarrierC2Support::is_heap_stable_test(dom) || // Not same input 1? 1091 prev_dom->in(0) != dom) { // One path of test does not dominate? 1092 if (dist < 0) return NULL; 1093 1094 dist--; 1095 prev_dom = dom; 1096 dom = IfNode::up_one_dom(dom); 1097 if (!dom) return NULL; 1098 } 1099 1100 // Check that we did not follow a loop back to ourselves 1101 if (n == dom) { 1102 return NULL; 1103 } 1104 1105 return n->as_If()->dominated_by(prev_dom, phase->is_IterGVN()); 1106 } 1107 1108 return NULL; 1109 } 1110 1111 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) { 1112 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1113 Node* u = n->fast_out(i); 1114 if (!is_shenandoah_wb_pre_call(u)) { 1115 return false; 1116 } 1117 } 1118 return n->outcnt() > 0; 1119 } 1120 1121 bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode) const { 1122 switch (opcode) { 1123 case Op_CallLeaf: 1124 case Op_CallLeafNoFP: { 1125 assert (n->is_Call(), ""); 1126 CallNode *call = n->as_Call(); 1127 if (ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(call)) { 1128 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt(); 1129 if (call->req() > cnt) { 1130 assert(call->req() == cnt + 1, "only one extra input"); 1131 Node *addp = call->in(cnt); 1132 assert(!ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(addp), "useless address computation?"); 1133 call->del_req(cnt); 1134 } 1135 } 1136 return false; 1137 } 1138 case Op_ShenandoahCompareAndSwapP: 1139 case Op_ShenandoahCompareAndSwapN: 1140 case Op_ShenandoahWeakCompareAndSwapN: 1141 case Op_ShenandoahWeakCompareAndSwapP: 1142 case Op_ShenandoahCompareAndExchangeP: 1143 case Op_ShenandoahCompareAndExchangeN: 1144 return true; 1145 case Op_ShenandoahLoadReferenceBarrier: 1146 assert(false, "should have been expanded already"); 1147 return true; 1148 default: 1149 return false; 1150 } 1151 } 1152 1153 bool ShenandoahBarrierSetC2::escape_add_to_con_graph(ConnectionGraph* conn_graph, PhaseGVN* gvn, Unique_Node_List* delayed_worklist, Node* n, uint opcode) const { 1154 switch (opcode) { 1155 case Op_ShenandoahCompareAndExchangeP: 1156 case Op_ShenandoahCompareAndExchangeN: 1157 conn_graph->add_objload_to_connection_graph(n, delayed_worklist); 1158 // fallthrough 1159 case Op_ShenandoahWeakCompareAndSwapP: 1160 case Op_ShenandoahWeakCompareAndSwapN: 1161 case Op_ShenandoahCompareAndSwapP: 1162 case Op_ShenandoahCompareAndSwapN: 1163 conn_graph->add_to_congraph_unsafe_access(n, opcode, delayed_worklist); 1164 return true; 1165 case Op_StoreP: { 1166 Node* adr = n->in(MemNode::Address); 1167 const Type* adr_type = gvn->type(adr); 1168 // Pointer stores in Shenandoah barriers looks like unsafe access. 1169 // Ignore such stores to be able scalar replace non-escaping 1170 // allocations. 1171 if (adr_type->isa_rawptr() && adr->is_AddP()) { 1172 Node* base = conn_graph->get_addp_base(adr); 1173 if (base->Opcode() == Op_LoadP && 1174 base->in(MemNode::Address)->is_AddP()) { 1175 adr = base->in(MemNode::Address); 1176 Node* tls = conn_graph->get_addp_base(adr); 1177 if (tls->Opcode() == Op_ThreadLocal) { 1178 int offs = (int) gvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot); 1179 const int buf_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()); 1180 if (offs == buf_offset) { 1181 return true; // Pre barrier previous oop value store. 1182 } 1183 } 1184 } 1185 } 1186 return false; 1187 } 1188 case Op_ShenandoahIUBarrier: 1189 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist); 1190 break; 1191 case Op_ShenandoahLoadReferenceBarrier: 1192 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), delayed_worklist); 1193 return true; 1194 default: 1195 // Nothing 1196 break; 1197 } 1198 return false; 1199 } 1200 1201 bool ShenandoahBarrierSetC2::escape_add_final_edges(ConnectionGraph* conn_graph, PhaseGVN* gvn, Node* n, uint opcode) const { 1202 switch (opcode) { 1203 case Op_ShenandoahCompareAndExchangeP: 1204 case Op_ShenandoahCompareAndExchangeN: { 1205 Node *adr = n->in(MemNode::Address); 1206 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL); 1207 // fallthrough 1208 } 1209 case Op_ShenandoahCompareAndSwapP: 1210 case Op_ShenandoahCompareAndSwapN: 1211 case Op_ShenandoahWeakCompareAndSwapP: 1212 case Op_ShenandoahWeakCompareAndSwapN: 1213 return conn_graph->add_final_edges_unsafe_access(n, opcode); 1214 case Op_ShenandoahIUBarrier: 1215 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), NULL); 1216 return true; 1217 case Op_ShenandoahLoadReferenceBarrier: 1218 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), NULL); 1219 return true; 1220 default: 1221 // Nothing 1222 break; 1223 } 1224 return false; 1225 } 1226 1227 bool ShenandoahBarrierSetC2::escape_has_out_with_unsafe_object(Node* n) const { 1228 return n->has_out_with(Op_ShenandoahCompareAndExchangeP) || n->has_out_with(Op_ShenandoahCompareAndExchangeN) || 1229 n->has_out_with(Op_ShenandoahCompareAndSwapP, Op_ShenandoahCompareAndSwapN, Op_ShenandoahWeakCompareAndSwapP, Op_ShenandoahWeakCompareAndSwapN); 1230 1231 } 1232 1233 bool ShenandoahBarrierSetC2::matcher_find_shared_post_visit(Matcher* matcher, Node* n, uint opcode) const { 1234 switch (opcode) { 1235 case Op_ShenandoahCompareAndExchangeP: 1236 case Op_ShenandoahCompareAndExchangeN: 1237 case Op_ShenandoahWeakCompareAndSwapP: 1238 case Op_ShenandoahWeakCompareAndSwapN: 1239 case Op_ShenandoahCompareAndSwapP: 1240 case Op_ShenandoahCompareAndSwapN: { // Convert trinary to binary-tree 1241 Node* newval = n->in(MemNode::ValueIn); 1242 Node* oldval = n->in(LoadStoreConditionalNode::ExpectedIn); 1243 Node* pair = new BinaryNode(oldval, newval); 1244 n->set_req(MemNode::ValueIn,pair); 1245 n->del_req(LoadStoreConditionalNode::ExpectedIn); 1246 return true; 1247 } 1248 default: 1249 break; 1250 } 1251 return false; 1252 } 1253 1254 bool ShenandoahBarrierSetC2::matcher_is_store_load_barrier(Node* x, uint xop) const { 1255 return xop == Op_ShenandoahCompareAndExchangeP || 1256 xop == Op_ShenandoahCompareAndExchangeN || 1257 xop == Op_ShenandoahWeakCompareAndSwapP || 1258 xop == Op_ShenandoahWeakCompareAndSwapN || 1259 xop == Op_ShenandoahCompareAndSwapN || 1260 xop == Op_ShenandoahCompareAndSwapP; 1261 }