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 "gc/shenandoah/mode/shenandoahMode.hpp" 37 #include "opto/arraycopynode.hpp" 38 #include "opto/escape.hpp" 39 #include "opto/graphKit.hpp" 40 #include "opto/idealKit.hpp" 41 #include "opto/macro.hpp" 42 #include "opto/movenode.hpp" 43 #include "opto/narrowptrnode.hpp" 44 #include "opto/rootnode.hpp" 45 #include "opto/runtime.hpp" 46 47 ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() { 48 return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2()); 49 } 50 51 ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena) 52 : _iu_barriers(new (comp_arena) GrowableArray<ShenandoahIUBarrierNode*>(comp_arena, 8, 0, nullptr)), 53 _load_reference_barriers(new (comp_arena) GrowableArray<ShenandoahLoadReferenceBarrierNode*>(comp_arena, 8, 0, nullptr)) { 54 } 55 56 int ShenandoahBarrierSetC2State::iu_barriers_count() const { 57 return _iu_barriers->length(); 58 } 59 60 ShenandoahIUBarrierNode* ShenandoahBarrierSetC2State::iu_barrier(int idx) const { 61 return _iu_barriers->at(idx); 62 } 63 64 void ShenandoahBarrierSetC2State::add_iu_barrier(ShenandoahIUBarrierNode* n) { 65 assert(!_iu_barriers->contains(n), "duplicate entry in barrier list"); 66 _iu_barriers->append(n); 67 } 68 69 void ShenandoahBarrierSetC2State::remove_iu_barrier(ShenandoahIUBarrierNode* n) { 70 _iu_barriers->remove_if_existing(n); 71 } 72 73 int ShenandoahBarrierSetC2State::load_reference_barriers_count() const { 74 return _load_reference_barriers->length(); 75 } 76 77 ShenandoahLoadReferenceBarrierNode* ShenandoahBarrierSetC2State::load_reference_barrier(int idx) const { 78 return _load_reference_barriers->at(idx); 79 } 80 81 void ShenandoahBarrierSetC2State::add_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) { 82 assert(!_load_reference_barriers->contains(n), "duplicate entry in barrier list"); 83 _load_reference_barriers->append(n); 84 } 85 86 void ShenandoahBarrierSetC2State::remove_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) { 87 if (_load_reference_barriers->contains(n)) { 88 _load_reference_barriers->remove(n); 89 } 90 } 91 92 Node* ShenandoahBarrierSetC2::shenandoah_iu_barrier(GraphKit* kit, Node* obj) const { 93 if (ShenandoahIUBarrier) { 94 return kit->gvn().transform(new ShenandoahIUBarrierNode(obj)); 95 } 96 return obj; 97 } 98 99 #define __ kit-> 100 101 bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr, 102 BasicType bt, uint adr_idx) const { 103 intptr_t offset = 0; 104 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); 105 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase); 106 107 if (offset == Type::OffsetBot) { 108 return false; // cannot unalias unless there are precise offsets 109 } 110 111 if (alloc == nullptr) { 112 return false; // No allocation found 113 } 114 115 intptr_t size_in_bytes = type2aelembytes(bt); 116 117 Node* mem = __ memory(adr_idx); // start searching here... 118 119 for (int cnt = 0; cnt < 50; cnt++) { 120 121 if (mem->is_Store()) { 122 123 Node* st_adr = mem->in(MemNode::Address); 124 intptr_t st_offset = 0; 125 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset); 126 127 if (st_base == nullptr) { 128 break; // inscrutable pointer 129 } 130 131 // Break we have found a store with same base and offset as ours so break 132 if (st_base == base && st_offset == offset) { 133 break; 134 } 135 136 if (st_offset != offset && st_offset != Type::OffsetBot) { 137 const int MAX_STORE = BytesPerLong; 138 if (st_offset >= offset + size_in_bytes || 139 st_offset <= offset - MAX_STORE || 140 st_offset <= offset - mem->as_Store()->memory_size()) { 141 // Success: The offsets are provably independent. 142 // (You may ask, why not just test st_offset != offset and be done? 143 // The answer is that stores of different sizes can co-exist 144 // in the same sequence of RawMem effects. We sometimes initialize 145 // a whole 'tile' of array elements with a single jint or jlong.) 146 mem = mem->in(MemNode::Memory); 147 continue; // advance through independent store memory 148 } 149 } 150 151 if (st_base != base 152 && MemNode::detect_ptr_independence(base, alloc, st_base, 153 AllocateNode::Ideal_allocation(st_base, phase), 154 phase)) { 155 // Success: The bases are provably independent. 156 mem = mem->in(MemNode::Memory); 157 continue; // advance through independent store memory 158 } 159 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) { 160 161 InitializeNode* st_init = mem->in(0)->as_Initialize(); 162 AllocateNode* st_alloc = st_init->allocation(); 163 164 // Make sure that we are looking at the same allocation site. 165 // The alloc variable is guaranteed to not be null here from earlier check. 166 if (alloc == st_alloc) { 167 // Check that the initialization is storing null so that no previous store 168 // has been moved up and directly write a reference 169 Node* captured_store = st_init->find_captured_store(offset, 170 type2aelembytes(T_OBJECT), 171 phase); 172 if (captured_store == nullptr || captured_store == st_init->zero_memory()) { 173 return true; 174 } 175 } 176 } 177 178 // Unless there is an explicit 'continue', we must bail out here, 179 // because 'mem' is an inscrutable memory state (e.g., a call). 180 break; 181 } 182 183 return false; 184 } 185 186 #undef __ 187 #define __ ideal. 188 189 void ShenandoahBarrierSetC2::satb_write_barrier_pre(GraphKit* kit, 190 bool do_load, 191 Node* obj, 192 Node* adr, 193 uint alias_idx, 194 Node* val, 195 const TypeOopPtr* val_type, 196 Node* pre_val, 197 BasicType bt) const { 198 // Some sanity checks 199 // Note: val is unused in this routine. 200 201 if (do_load) { 202 // We need to generate the load of the previous value 203 assert(adr != nullptr, "where are loading from?"); 204 assert(pre_val == nullptr, "loaded already?"); 205 assert(val_type != nullptr, "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 != nullptr, "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::YOUNG_MARKING | ShenandoahHeap::OLD_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 != nullptr) 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 != nullptr) 282 } __ end_if(); // (!marking) 283 284 // Final sync IdealKit and GraphKit. 285 kit->final_sync(ideal); 286 287 if (ShenandoahSATBBarrier && adr != nullptr) { 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::YOUNG_MARKING | ShenandoahHeap::OLD_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 != nullptr && 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 != nullptr) { 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 != nullptr) { 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->instance_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 == nullptr 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 nullptr /* obj */, nullptr /* adr */, max_juint /* alias_idx */, nullptr /* val */, nullptr /* 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 Node* ShenandoahBarrierSetC2::byte_map_base_node(GraphKit* kit) const { 455 BarrierSet* bs = BarrierSet::barrier_set(); 456 ShenandoahBarrierSet* ctbs = barrier_set_cast<ShenandoahBarrierSet>(bs); 457 CardTable::CardValue* card_table_base = ctbs->card_table()->byte_map_base(); 458 if (card_table_base != nullptr) { 459 return kit->makecon(TypeRawPtr::make((address)card_table_base)); 460 } else { 461 return kit->null(); 462 } 463 } 464 465 void ShenandoahBarrierSetC2::post_barrier(GraphKit* kit, 466 Node* ctl, 467 Node* oop_store, 468 Node* obj, 469 Node* adr, 470 uint adr_idx, 471 Node* val, 472 BasicType bt, 473 bool use_precise) const { 474 if (!ShenandoahHeap::heap()->mode()->is_generational()) { 475 return; 476 } 477 478 ShenandoahBarrierSet* ctbs = barrier_set_cast<ShenandoahBarrierSet>(BarrierSet::barrier_set()); 479 CardTable* ct = ctbs->card_table(); 480 // No store check needed if we're storing a nullptr or an old object 481 // (latter case is probably a string constant). The concurrent 482 // mark sweep garbage collector, however, needs to have all nonNull 483 // oop updates flagged via card-marks. 484 if (val != nullptr && val->is_Con()) { 485 // must be either an oop or NULL 486 const Type* t = val->bottom_type(); 487 if (t == TypePtr::NULL_PTR || t == Type::TOP) 488 // stores of null never (?) need barriers 489 return; 490 } 491 492 if (ReduceInitialCardMarks && obj == kit->just_allocated_object(kit->control())) { 493 // We can skip marks on a freshly-allocated object in Eden. 494 // Keep this code in sync with new_deferred_store_barrier() in runtime.cpp. 495 // That routine informs GC to take appropriate compensating steps, 496 // upon a slow-path allocation, so as to make this card-mark 497 // elision safe. 498 return; 499 } 500 501 if (!use_precise) { 502 // All card marks for a (non-array) instance are in one place: 503 adr = obj; 504 } 505 // (Else it's an array (or unknown), and we want more precise card marks.) 506 assert(adr != nullptr, ""); 507 508 IdealKit ideal(kit, true); 509 510 // Convert the pointer to an int prior to doing math on it 511 Node* cast = __ CastPX(__ ctrl(), adr); 512 513 // Divide by card size 514 Node* card_offset = __ URShiftX( cast, __ ConI(CardTable::card_shift()) ); 515 516 // Combine card table base and card offset 517 Node* card_adr = __ AddP(__ top(), byte_map_base_node(kit), card_offset ); 518 519 // Get the alias_index for raw card-mark memory 520 int adr_type = Compile::AliasIdxRaw; 521 Node* zero = __ ConI(0); // Dirty card value 522 523 if (UseCondCardMark) { 524 // The classic GC reference write barrier is typically implemented 525 // as a store into the global card mark table. Unfortunately 526 // unconditional stores can result in false sharing and excessive 527 // coherence traffic as well as false transactional aborts. 528 // UseCondCardMark enables MP "polite" conditional card mark 529 // stores. In theory we could relax the load from ctrl() to 530 // no_ctrl, but that doesn't buy much latitude. 531 Node* card_val = __ load( __ ctrl(), card_adr, TypeInt::BYTE, T_BYTE, adr_type); 532 __ if_then(card_val, BoolTest::ne, zero); 533 } 534 535 // Smash zero into card 536 __ store(__ ctrl(), card_adr, zero, T_BYTE, adr_type, MemNode::unordered); 537 538 if (UseCondCardMark) { 539 __ end_if(); 540 } 541 542 // Final sync IdealKit and GraphKit. 543 kit->final_sync(ideal); 544 } 545 546 #undef __ 547 548 const TypeFunc* ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type() { 549 const Type **fields = TypeTuple::fields(2); 550 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value 551 fields[TypeFunc::Parms+1] = TypeRawPtr::NOTNULL; // thread 552 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields); 553 554 // create result type (range) 555 fields = TypeTuple::fields(0); 556 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields); 557 558 return TypeFunc::make(domain, range); 559 } 560 561 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type() { 562 const Type **fields = TypeTuple::fields(1); 563 fields[TypeFunc::Parms+0] = TypeOopPtr::NOTNULL; // src oop 564 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields); 565 566 // create result type (range) 567 fields = TypeTuple::fields(0); 568 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields); 569 570 return TypeFunc::make(domain, range); 571 } 572 573 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_load_reference_barrier_Type() { 574 const Type **fields = TypeTuple::fields(2); 575 fields[TypeFunc::Parms+0] = TypeOopPtr::BOTTOM; // original field value 576 fields[TypeFunc::Parms+1] = TypeRawPtr::BOTTOM; // original load address 577 578 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields); 579 580 // create result type (range) 581 fields = TypeTuple::fields(1); 582 fields[TypeFunc::Parms+0] = TypeOopPtr::BOTTOM; 583 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields); 584 585 return TypeFunc::make(domain, range); 586 } 587 588 Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const { 589 DecoratorSet decorators = access.decorators(); 590 591 const TypePtr* adr_type = access.addr().type(); 592 Node* adr = access.addr().node(); 593 594 if (!access.is_oop()) { 595 return BarrierSetC2::store_at_resolved(access, val); 596 } 597 598 if (access.is_parse_access()) { 599 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access); 600 GraphKit* kit = parse_access.kit(); 601 602 uint adr_idx = kit->C->get_alias_index(adr_type); 603 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); 604 Node* value = val.node(); 605 value = shenandoah_iu_barrier(kit, value); 606 val.set_node(value); 607 shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(), 608 static_cast<const TypeOopPtr*>(val.type()), nullptr /* pre_val */, access.type()); 609 610 Node* result = BarrierSetC2::store_at_resolved(access, val); 611 612 bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0; 613 bool is_array = (decorators & IS_ARRAY) != 0; 614 bool use_precise = is_array || anonymous; 615 post_barrier(kit, kit->control(), access.raw_access(), access.base(), adr, adr_idx, val.node(), access.type(), use_precise); 616 return result; 617 } else { 618 assert(access.is_opt_access(), "only for optimization passes"); 619 assert(((decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0 || !ShenandoahSATBBarrier) && (decorators & C2_ARRAY_COPY) != 0, "unexpected caller of this code"); 620 C2OptAccess& opt_access = static_cast<C2OptAccess&>(access); 621 PhaseGVN& gvn = opt_access.gvn(); 622 623 if (ShenandoahIUBarrier) { 624 Node* enqueue = gvn.transform(new ShenandoahIUBarrierNode(val.node())); 625 val.set_node(enqueue); 626 } 627 return BarrierSetC2::store_at_resolved(access, val); 628 } 629 } 630 631 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const { 632 // 1: non-reference load, no additional barrier is needed 633 if (!access.is_oop()) { 634 return BarrierSetC2::load_at_resolved(access, val_type);; 635 } 636 637 Node* load = BarrierSetC2::load_at_resolved(access, val_type); 638 DecoratorSet decorators = access.decorators(); 639 BasicType type = access.type(); 640 641 // 2: apply LRB if needed 642 if (ShenandoahBarrierSet::need_load_reference_barrier(decorators, type)) { 643 load = new ShenandoahLoadReferenceBarrierNode(nullptr, load, decorators); 644 if (access.is_parse_access()) { 645 load = static_cast<C2ParseAccess &>(access).kit()->gvn().transform(load); 646 } else { 647 load = static_cast<C2OptAccess &>(access).gvn().transform(load); 648 } 649 } 650 651 // 3: apply keep-alive barrier for java.lang.ref.Reference if needed 652 if (ShenandoahBarrierSet::need_keep_alive_barrier(decorators, type)) { 653 Node* top = Compile::current()->top(); 654 Node* adr = access.addr().node(); 655 Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : top; 656 Node* obj = access.base(); 657 658 bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0; 659 bool on_weak_ref = (decorators & (ON_WEAK_OOP_REF | ON_PHANTOM_OOP_REF)) != 0; 660 bool keep_alive = (decorators & AS_NO_KEEPALIVE) == 0; 661 662 // If we are reading the value of the referent field of a Reference 663 // object (either by using Unsafe directly or through reflection) 664 // then, if SATB is enabled, we need to record the referent in an 665 // SATB log buffer using the pre-barrier mechanism. 666 // Also we need to add memory barrier to prevent commoning reads 667 // from this field across safepoint since GC can change its value. 668 if (!on_weak_ref || (unknown && (offset == top || obj == top)) || !keep_alive) { 669 return load; 670 } 671 672 assert(access.is_parse_access(), "entry not supported at optimization time"); 673 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access); 674 GraphKit* kit = parse_access.kit(); 675 bool mismatched = (decorators & C2_MISMATCHED) != 0; 676 bool is_unordered = (decorators & MO_UNORDERED) != 0; 677 bool in_native = (decorators & IN_NATIVE) != 0; 678 bool need_cpu_mem_bar = !is_unordered || mismatched || in_native; 679 680 if (on_weak_ref) { 681 // Use the pre-barrier to record the value in the referent field 682 satb_write_barrier_pre(kit, false /* do_load */, 683 nullptr /* obj */, nullptr /* adr */, max_juint /* alias_idx */, nullptr /* val */, nullptr /* val_type */, 684 load /* pre_val */, T_OBJECT); 685 // Add memory barrier to prevent commoning reads from this field 686 // across safepoint since GC can change its value. 687 kit->insert_mem_bar(Op_MemBarCPUOrder); 688 } else if (unknown) { 689 // We do not require a mem bar inside pre_barrier if need_mem_bar 690 // is set: the barriers would be emitted by us. 691 insert_pre_barrier(kit, obj, offset, load, !need_cpu_mem_bar); 692 } 693 } 694 695 return load; 696 } 697 698 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 699 Node* new_val, const Type* value_type) const { 700 GraphKit* kit = access.kit(); 701 if (access.is_oop()) { 702 new_val = shenandoah_iu_barrier(kit, new_val); 703 shenandoah_write_barrier_pre(kit, false /* do_load */, 704 nullptr, nullptr, max_juint, nullptr, nullptr, 705 expected_val /* pre_val */, T_OBJECT); 706 707 MemNode::MemOrd mo = access.mem_node_mo(); 708 Node* mem = access.memory(); 709 Node* adr = access.addr().node(); 710 const TypePtr* adr_type = access.addr().type(); 711 Node* load_store = nullptr; 712 713 #ifdef _LP64 714 if (adr->bottom_type()->is_ptr_to_narrowoop()) { 715 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop())); 716 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop())); 717 if (ShenandoahCASBarrier) { 718 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo)); 719 } else { 720 load_store = kit->gvn().transform(new CompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo)); 721 } 722 } else 723 #endif 724 { 725 if (ShenandoahCASBarrier) { 726 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo)); 727 } else { 728 load_store = kit->gvn().transform(new CompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo)); 729 } 730 } 731 732 access.set_raw_access(load_store); 733 pin_atomic_op(access); 734 735 #ifdef _LP64 736 if (adr->bottom_type()->is_ptr_to_narrowoop()) { 737 load_store = kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type())); 738 } 739 #endif 740 load_store = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(nullptr, load_store, access.decorators())); 741 post_barrier(kit, kit->control(), access.raw_access(), access.base(), access.addr().node(), access.alias_idx(), new_val, T_OBJECT, true); 742 return load_store; 743 } 744 return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type); 745 } 746 747 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val, 748 Node* new_val, const Type* value_type) const { 749 GraphKit* kit = access.kit(); 750 if (access.is_oop()) { 751 new_val = shenandoah_iu_barrier(kit, new_val); 752 shenandoah_write_barrier_pre(kit, false /* do_load */, 753 nullptr, nullptr, max_juint, nullptr, nullptr, 754 expected_val /* pre_val */, T_OBJECT); 755 DecoratorSet decorators = access.decorators(); 756 MemNode::MemOrd mo = access.mem_node_mo(); 757 Node* mem = access.memory(); 758 bool is_weak_cas = (decorators & C2_WEAK_CMPXCHG) != 0; 759 Node* load_store = nullptr; 760 Node* adr = access.addr().node(); 761 #ifdef _LP64 762 if (adr->bottom_type()->is_ptr_to_narrowoop()) { 763 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop())); 764 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop())); 765 if (ShenandoahCASBarrier) { 766 if (is_weak_cas) { 767 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); 768 } else { 769 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); 770 } 771 } else { 772 if (is_weak_cas) { 773 load_store = kit->gvn().transform(new WeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); 774 } else { 775 load_store = kit->gvn().transform(new CompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo)); 776 } 777 } 778 } else 779 #endif 780 { 781 if (ShenandoahCASBarrier) { 782 if (is_weak_cas) { 783 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); 784 } else { 785 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); 786 } 787 } else { 788 if (is_weak_cas) { 789 load_store = kit->gvn().transform(new WeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); 790 } else { 791 load_store = kit->gvn().transform(new CompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo)); 792 } 793 } 794 } 795 access.set_raw_access(load_store); 796 pin_atomic_op(access); 797 post_barrier(kit, kit->control(), access.raw_access(), access.base(), 798 access.addr().node(), access.alias_idx(), new_val, T_OBJECT, true); 799 return load_store; 800 } 801 return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type); 802 } 803 804 Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* val, const Type* value_type) const { 805 GraphKit* kit = access.kit(); 806 if (access.is_oop()) { 807 val = shenandoah_iu_barrier(kit, val); 808 } 809 Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type); 810 if (access.is_oop()) { 811 result = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(nullptr, result, access.decorators())); 812 shenandoah_write_barrier_pre(kit, false /* do_load */, 813 nullptr, nullptr, max_juint, nullptr, nullptr, 814 result /* pre_val */, T_OBJECT); 815 post_barrier(kit, kit->control(), access.raw_access(), access.base(), 816 access.addr().node(), access.alias_idx(), val, T_OBJECT, true); 817 } 818 return result; 819 } 820 821 822 bool ShenandoahBarrierSetC2::is_gc_pre_barrier_node(Node* node) const { 823 return is_shenandoah_wb_pre_call(node); 824 } 825 826 // Support for GC barriers emitted during parsing 827 bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const { 828 if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier || node->Opcode() == Op_ShenandoahIUBarrier) return true; 829 if (node->Opcode() != Op_CallLeaf && node->Opcode() != Op_CallLeafNoFP) { 830 return false; 831 } 832 CallLeafNode *call = node->as_CallLeaf(); 833 if (call->_name == nullptr) { 834 return false; 835 } 836 837 return strcmp(call->_name, "shenandoah_clone_barrier") == 0 || 838 strcmp(call->_name, "shenandoah_cas_obj") == 0 || 839 strcmp(call->_name, "shenandoah_wb_pre") == 0; 840 } 841 842 Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const { 843 if (c == nullptr) { 844 return c; 845 } 846 if (c->Opcode() == Op_ShenandoahLoadReferenceBarrier) { 847 return c->in(ShenandoahLoadReferenceBarrierNode::ValueIn); 848 } 849 if (c->Opcode() == Op_ShenandoahIUBarrier) { 850 c = c->in(1); 851 } 852 return c; 853 } 854 855 bool ShenandoahBarrierSetC2::expand_barriers(Compile* C, PhaseIterGVN& igvn) const { 856 return !ShenandoahBarrierC2Support::expand(C, igvn); 857 } 858 859 bool ShenandoahBarrierSetC2::optimize_loops(PhaseIdealLoop* phase, LoopOptsMode mode, VectorSet& visited, Node_Stack& nstack, Node_List& worklist) const { 860 if (mode == LoopOptsShenandoahExpand) { 861 assert(UseShenandoahGC, "only for shenandoah"); 862 ShenandoahBarrierC2Support::pin_and_expand(phase); 863 return true; 864 } else if (mode == LoopOptsShenandoahPostExpand) { 865 assert(UseShenandoahGC, "only for shenandoah"); 866 visited.clear(); 867 ShenandoahBarrierC2Support::optimize_after_expansion(visited, nstack, worklist, phase); 868 return true; 869 } 870 return false; 871 } 872 873 bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, bool is_clone_instance, ArrayCopyPhase phase) const { 874 bool is_oop = is_reference_type(type); 875 if (!is_oop) { 876 return false; 877 } 878 if (ShenandoahSATBBarrier && tightly_coupled_alloc) { 879 if (phase == Optimization) { 880 return false; 881 } 882 return !is_clone; 883 } 884 if (phase == Optimization) { 885 return !ShenandoahIUBarrier; 886 } 887 return true; 888 } 889 890 bool ShenandoahBarrierSetC2::clone_needs_barrier(Node* src, PhaseGVN& gvn) { 891 const TypeOopPtr* src_type = gvn.type(src)->is_oopptr(); 892 if (src_type->isa_instptr() != nullptr) { 893 ciInstanceKlass* ik = src_type->is_instptr()->instance_klass(); 894 if ((src_type->klass_is_exact() || !ik->has_subklass()) && !ik->has_injected_fields()) { 895 if (ik->has_object_fields()) { 896 return true; 897 } else { 898 if (!src_type->klass_is_exact()) { 899 Compile::current()->dependencies()->assert_leaf_type(ik); 900 } 901 } 902 } else { 903 return true; 904 } 905 } else if (src_type->isa_aryptr()) { 906 BasicType src_elem = src_type->isa_aryptr()->elem()->array_element_basic_type(); 907 if (is_reference_type(src_elem, true)) { 908 return true; 909 } 910 } else { 911 return true; 912 } 913 return false; 914 } 915 916 void ShenandoahBarrierSetC2::clone_at_expansion(PhaseMacroExpand* phase, ArrayCopyNode* ac) const { 917 Node* ctrl = ac->in(TypeFunc::Control); 918 Node* mem = ac->in(TypeFunc::Memory); 919 Node* src_base = ac->in(ArrayCopyNode::Src); 920 Node* src_offset = ac->in(ArrayCopyNode::SrcPos); 921 Node* dest_base = ac->in(ArrayCopyNode::Dest); 922 Node* dest_offset = ac->in(ArrayCopyNode::DestPos); 923 Node* length = ac->in(ArrayCopyNode::Length); 924 925 Node* src = phase->basic_plus_adr(src_base, src_offset); 926 Node* dest = phase->basic_plus_adr(dest_base, dest_offset); 927 928 if (ShenandoahCloneBarrier && clone_needs_barrier(src, phase->igvn())) { 929 // Check if heap is has forwarded objects. If it does, we need to call into the special 930 // routine that would fix up source references before we can continue. 931 932 enum { _heap_stable = 1, _heap_unstable, PATH_LIMIT }; 933 Node* region = new RegionNode(PATH_LIMIT); 934 Node* mem_phi = new PhiNode(region, Type::MEMORY, TypeRawPtr::BOTTOM); 935 936 Node* thread = phase->transform_later(new ThreadLocalNode()); 937 Node* offset = phase->igvn().MakeConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset())); 938 Node* gc_state_addr = phase->transform_later(new AddPNode(phase->C->top(), thread, offset)); 939 940 uint gc_state_idx = Compile::AliasIdxRaw; 941 const TypePtr* gc_state_adr_type = nullptr; // debug-mode-only argument 942 debug_only(gc_state_adr_type = phase->C->get_adr_type(gc_state_idx)); 943 944 Node* gc_state = phase->transform_later(new LoadBNode(ctrl, mem, gc_state_addr, gc_state_adr_type, TypeInt::BYTE, MemNode::unordered)); 945 int flags = ShenandoahHeap::HAS_FORWARDED; 946 if (ShenandoahIUBarrier) { 947 flags |= ShenandoahHeap::YOUNG_MARKING; 948 } 949 Node* stable_and = phase->transform_later(new AndINode(gc_state, phase->igvn().intcon(flags))); 950 Node* stable_cmp = phase->transform_later(new CmpINode(stable_and, phase->igvn().zerocon(T_INT))); 951 Node* stable_test = phase->transform_later(new BoolNode(stable_cmp, BoolTest::ne)); 952 953 IfNode* stable_iff = phase->transform_later(new IfNode(ctrl, stable_test, PROB_UNLIKELY(0.999), COUNT_UNKNOWN))->as_If(); 954 Node* stable_ctrl = phase->transform_later(new IfFalseNode(stable_iff)); 955 Node* unstable_ctrl = phase->transform_later(new IfTrueNode(stable_iff)); 956 957 // Heap is stable, no need to do anything additional 958 region->init_req(_heap_stable, stable_ctrl); 959 mem_phi->init_req(_heap_stable, mem); 960 961 // Heap is unstable, call into clone barrier stub 962 Node* call = phase->make_leaf_call(unstable_ctrl, mem, 963 ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type(), 964 CAST_FROM_FN_PTR(address, ShenandoahRuntime::shenandoah_clone_barrier), 965 "shenandoah_clone", 966 TypeRawPtr::BOTTOM, 967 src_base); 968 call = phase->transform_later(call); 969 970 ctrl = phase->transform_later(new ProjNode(call, TypeFunc::Control)); 971 mem = phase->transform_later(new ProjNode(call, TypeFunc::Memory)); 972 region->init_req(_heap_unstable, ctrl); 973 mem_phi->init_req(_heap_unstable, mem); 974 975 // Wire up the actual arraycopy stub now 976 ctrl = phase->transform_later(region); 977 mem = phase->transform_later(mem_phi); 978 979 const char* name = "arraycopy"; 980 call = phase->make_leaf_call(ctrl, mem, 981 OptoRuntime::fast_arraycopy_Type(), 982 phase->basictype2arraycopy(T_LONG, nullptr, nullptr, true, name, true), 983 name, TypeRawPtr::BOTTOM, 984 src, dest, length 985 LP64_ONLY(COMMA phase->top())); 986 call = phase->transform_later(call); 987 988 // Hook up the whole thing into the graph 989 phase->igvn().replace_node(ac, call); 990 } else { 991 BarrierSetC2::clone_at_expansion(phase, ac); 992 } 993 } 994 995 996 // Support for macro expanded GC barriers 997 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const { 998 if (node->Opcode() == Op_ShenandoahIUBarrier) { 999 state()->add_iu_barrier((ShenandoahIUBarrierNode*) node); 1000 } 1001 if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) { 1002 state()->add_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node); 1003 } 1004 } 1005 1006 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const { 1007 if (node->Opcode() == Op_ShenandoahIUBarrier) { 1008 state()->remove_iu_barrier((ShenandoahIUBarrierNode*) node); 1009 } 1010 if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) { 1011 state()->remove_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node); 1012 } 1013 } 1014 1015 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const { 1016 if (is_shenandoah_wb_pre_call(node)) { 1017 shenandoah_eliminate_wb_pre(node, ¯o->igvn()); 1018 } 1019 if (node->Opcode() == Op_CastP2X && ShenandoahHeap::heap()->mode()->is_generational()) { 1020 assert(node->Opcode() == Op_CastP2X, "ConvP2XNode required"); 1021 Node *shift = node->unique_out(); 1022 Node *addp = shift->unique_out(); 1023 for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) { 1024 Node *mem = addp->last_out(j); 1025 if (UseCondCardMark && mem->is_Load()) { 1026 assert(mem->Opcode() == Op_LoadB, "unexpected code shape"); 1027 // The load is checking if the card has been written so 1028 // replace it with zero to fold the test. 1029 macro->replace_node(mem, macro->intcon(0)); 1030 continue; 1031 } 1032 assert(mem->is_Store(), "store required"); 1033 macro->replace_node(mem, mem->in(MemNode::Memory)); 1034 } 1035 } 1036 } 1037 1038 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const { 1039 assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), ""); 1040 Node* c = call->as_Call()->proj_out(TypeFunc::Control); 1041 c = c->unique_ctrl_out(); 1042 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); 1043 c = c->unique_ctrl_out(); 1044 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); 1045 Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0); 1046 assert(iff->is_If(), "expect test"); 1047 if (!is_shenandoah_marking_if(igvn, iff)) { 1048 c = c->unique_ctrl_out(); 1049 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); 1050 iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0); 1051 assert(is_shenandoah_marking_if(igvn, iff), "expect marking test"); 1052 } 1053 Node* cmpx = iff->in(1)->in(1); 1054 igvn->replace_node(cmpx, igvn->makecon(TypeInt::CC_EQ)); 1055 igvn->rehash_node_delayed(call); 1056 call->del_req(call->req()-1); 1057 } 1058 1059 void ShenandoahBarrierSetC2::enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const { 1060 if (node->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(node)) { 1061 igvn->add_users_to_worklist(node); 1062 } 1063 } 1064 1065 void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const { 1066 for (uint i = 0; i < useful.size(); i++) { 1067 Node* n = useful.at(i); 1068 if (n->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(n)) { 1069 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1070 C->record_for_igvn(n->fast_out(i)); 1071 } 1072 } 1073 } 1074 for (int i = state()->iu_barriers_count() - 1; i >= 0; i--) { 1075 ShenandoahIUBarrierNode* n = state()->iu_barrier(i); 1076 if (!useful.member(n)) { 1077 state()->remove_iu_barrier(n); 1078 } 1079 } 1080 for (int i = state()->load_reference_barriers_count() - 1; i >= 0; i--) { 1081 ShenandoahLoadReferenceBarrierNode* n = state()->load_reference_barrier(i); 1082 if (!useful.member(n)) { 1083 state()->remove_load_reference_barrier(n); 1084 } 1085 } 1086 } 1087 1088 void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const { 1089 return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena); 1090 } 1091 1092 ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const { 1093 return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state()); 1094 } 1095 1096 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be 1097 // expanded later, then now is the time to do so. 1098 bool ShenandoahBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { return false; } 1099 1100 #ifdef ASSERT 1101 void ShenandoahBarrierSetC2::verify_gc_barriers(Compile* compile, CompilePhase phase) const { 1102 if (ShenandoahVerifyOptoBarriers && phase == BarrierSetC2::BeforeMacroExpand) { 1103 ShenandoahBarrierC2Support::verify(Compile::current()->root()); 1104 } else if (phase == BarrierSetC2::BeforeCodeGen) { 1105 // Verify Shenandoah pre-barriers 1106 const int marking_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()); 1107 1108 Unique_Node_List visited; 1109 Node_List worklist; 1110 // We're going to walk control flow backwards starting from the Root 1111 worklist.push(compile->root()); 1112 while (worklist.size() > 0) { 1113 Node *x = worklist.pop(); 1114 if (x == nullptr || x == compile->top()) continue; 1115 if (visited.member(x)) { 1116 continue; 1117 } else { 1118 visited.push(x); 1119 } 1120 1121 if (x->is_Region()) { 1122 for (uint i = 1; i < x->req(); i++) { 1123 worklist.push(x->in(i)); 1124 } 1125 } else { 1126 worklist.push(x->in(0)); 1127 // We are looking for the pattern: 1128 // /->ThreadLocal 1129 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset) 1130 // \->ConI(0) 1131 // We want to verify that the If and the LoadB have the same control 1132 // See GraphKit::g1_write_barrier_pre() 1133 if (x->is_If()) { 1134 IfNode *iff = x->as_If(); 1135 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) { 1136 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp(); 1137 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0 1138 && cmp->in(1)->is_Load()) { 1139 LoadNode *load = cmp->in(1)->as_Load(); 1140 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal 1141 && load->in(2)->in(3)->is_Con() 1142 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) { 1143 1144 Node *if_ctrl = iff->in(0); 1145 Node *load_ctrl = load->in(0); 1146 1147 if (if_ctrl != load_ctrl) { 1148 // Skip possible CProj->NeverBranch in infinite loops 1149 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj) 1150 && if_ctrl->in(0)->is_NeverBranch()) { 1151 if_ctrl = if_ctrl->in(0)->in(0); 1152 } 1153 } 1154 assert(load_ctrl != nullptr && if_ctrl == load_ctrl, "controls must match"); 1155 } 1156 } 1157 } 1158 } 1159 } 1160 } 1161 } 1162 } 1163 #endif 1164 1165 Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const { 1166 if (is_shenandoah_wb_pre_call(n)) { 1167 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt(); 1168 if (n->req() > cnt) { 1169 Node* addp = n->in(cnt); 1170 if (has_only_shenandoah_wb_pre_uses(addp)) { 1171 n->del_req(cnt); 1172 if (can_reshape) { 1173 phase->is_IterGVN()->_worklist.push(addp); 1174 } 1175 return n; 1176 } 1177 } 1178 } 1179 if (n->Opcode() == Op_CmpP) { 1180 Node* in1 = n->in(1); 1181 Node* in2 = n->in(2); 1182 1183 // If one input is null, then step over the strong LRB barriers on the other input 1184 if (in1->bottom_type() == TypePtr::NULL_PTR && 1185 !((in2->Opcode() == Op_ShenandoahLoadReferenceBarrier) && 1186 !ShenandoahBarrierSet::is_strong_access(((ShenandoahLoadReferenceBarrierNode*)in2)->decorators()))) { 1187 in2 = step_over_gc_barrier(in2); 1188 } 1189 if (in2->bottom_type() == TypePtr::NULL_PTR && 1190 !((in1->Opcode() == Op_ShenandoahLoadReferenceBarrier) && 1191 !ShenandoahBarrierSet::is_strong_access(((ShenandoahLoadReferenceBarrierNode*)in1)->decorators()))) { 1192 in1 = step_over_gc_barrier(in1); 1193 } 1194 1195 if (in1 != n->in(1)) { 1196 n->set_req_X(1, in1, phase); 1197 assert(in2 == n->in(2), "only one change"); 1198 return n; 1199 } 1200 if (in2 != n->in(2)) { 1201 n->set_req_X(2, in2, phase); 1202 return n; 1203 } 1204 } else if (can_reshape && 1205 n->Opcode() == Op_If && 1206 ShenandoahBarrierC2Support::is_heap_stable_test(n) && 1207 n->in(0) != nullptr && 1208 n->outcnt() == 2) { 1209 Node* dom = n->in(0); 1210 Node* prev_dom = n; 1211 int op = n->Opcode(); 1212 int dist = 16; 1213 // Search up the dominator tree for another heap stable test 1214 while (dom->Opcode() != op || // Not same opcode? 1215 !ShenandoahBarrierC2Support::is_heap_stable_test(dom) || // Not same input 1? 1216 prev_dom->in(0) != dom) { // One path of test does not dominate? 1217 if (dist < 0) return nullptr; 1218 1219 dist--; 1220 prev_dom = dom; 1221 dom = IfNode::up_one_dom(dom); 1222 if (!dom) return nullptr; 1223 } 1224 1225 // Check that we did not follow a loop back to ourselves 1226 if (n == dom) { 1227 return nullptr; 1228 } 1229 1230 return n->as_If()->dominated_by(prev_dom, phase->is_IterGVN()); 1231 } 1232 1233 return nullptr; 1234 } 1235 1236 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) { 1237 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 1238 Node* u = n->fast_out(i); 1239 if (!is_shenandoah_wb_pre_call(u)) { 1240 return false; 1241 } 1242 } 1243 return n->outcnt() > 0; 1244 } 1245 1246 bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode, Unique_Node_List& dead_nodes) const { 1247 switch (opcode) { 1248 case Op_CallLeaf: 1249 case Op_CallLeafNoFP: { 1250 assert (n->is_Call(), ""); 1251 CallNode *call = n->as_Call(); 1252 if (ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(call)) { 1253 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt(); 1254 if (call->req() > cnt) { 1255 assert(call->req() == cnt + 1, "only one extra input"); 1256 Node *addp = call->in(cnt); 1257 assert(!ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(addp), "useless address computation?"); 1258 call->del_req(cnt); 1259 } 1260 } 1261 return false; 1262 } 1263 case Op_ShenandoahCompareAndSwapP: 1264 case Op_ShenandoahCompareAndSwapN: 1265 case Op_ShenandoahWeakCompareAndSwapN: 1266 case Op_ShenandoahWeakCompareAndSwapP: 1267 case Op_ShenandoahCompareAndExchangeP: 1268 case Op_ShenandoahCompareAndExchangeN: 1269 return true; 1270 case Op_ShenandoahLoadReferenceBarrier: 1271 assert(false, "should have been expanded already"); 1272 return true; 1273 default: 1274 return false; 1275 } 1276 } 1277 1278 bool ShenandoahBarrierSetC2::escape_add_to_con_graph(ConnectionGraph* conn_graph, PhaseGVN* gvn, Unique_Node_List* delayed_worklist, Node* n, uint opcode) const { 1279 switch (opcode) { 1280 case Op_ShenandoahCompareAndExchangeP: 1281 case Op_ShenandoahCompareAndExchangeN: 1282 conn_graph->add_objload_to_connection_graph(n, delayed_worklist); 1283 // fallthrough 1284 case Op_ShenandoahWeakCompareAndSwapP: 1285 case Op_ShenandoahWeakCompareAndSwapN: 1286 case Op_ShenandoahCompareAndSwapP: 1287 case Op_ShenandoahCompareAndSwapN: 1288 conn_graph->add_to_congraph_unsafe_access(n, opcode, delayed_worklist); 1289 return true; 1290 case Op_StoreP: { 1291 Node* adr = n->in(MemNode::Address); 1292 const Type* adr_type = gvn->type(adr); 1293 // Pointer stores in Shenandoah barriers looks like unsafe access. 1294 // Ignore such stores to be able scalar replace non-escaping 1295 // allocations. 1296 if (adr_type->isa_rawptr() && adr->is_AddP()) { 1297 Node* base = conn_graph->get_addp_base(adr); 1298 if (base->Opcode() == Op_LoadP && 1299 base->in(MemNode::Address)->is_AddP()) { 1300 adr = base->in(MemNode::Address); 1301 Node* tls = conn_graph->get_addp_base(adr); 1302 if (tls->Opcode() == Op_ThreadLocal) { 1303 int offs = (int) gvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot); 1304 const int buf_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()); 1305 if (offs == buf_offset) { 1306 return true; // Pre barrier previous oop value store. 1307 } 1308 } 1309 } 1310 } 1311 return false; 1312 } 1313 case Op_ShenandoahIUBarrier: 1314 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist); 1315 break; 1316 case Op_ShenandoahLoadReferenceBarrier: 1317 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), delayed_worklist); 1318 return true; 1319 default: 1320 // Nothing 1321 break; 1322 } 1323 return false; 1324 } 1325 1326 bool ShenandoahBarrierSetC2::escape_add_final_edges(ConnectionGraph* conn_graph, PhaseGVN* gvn, Node* n, uint opcode) const { 1327 switch (opcode) { 1328 case Op_ShenandoahCompareAndExchangeP: 1329 case Op_ShenandoahCompareAndExchangeN: { 1330 Node *adr = n->in(MemNode::Address); 1331 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, adr, nullptr); 1332 // fallthrough 1333 } 1334 case Op_ShenandoahCompareAndSwapP: 1335 case Op_ShenandoahCompareAndSwapN: 1336 case Op_ShenandoahWeakCompareAndSwapP: 1337 case Op_ShenandoahWeakCompareAndSwapN: 1338 return conn_graph->add_final_edges_unsafe_access(n, opcode); 1339 case Op_ShenandoahIUBarrier: 1340 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), nullptr); 1341 return true; 1342 case Op_ShenandoahLoadReferenceBarrier: 1343 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), nullptr); 1344 return true; 1345 default: 1346 // Nothing 1347 break; 1348 } 1349 return false; 1350 } 1351 1352 bool ShenandoahBarrierSetC2::escape_has_out_with_unsafe_object(Node* n) const { 1353 return n->has_out_with(Op_ShenandoahCompareAndExchangeP) || n->has_out_with(Op_ShenandoahCompareAndExchangeN) || 1354 n->has_out_with(Op_ShenandoahCompareAndSwapP, Op_ShenandoahCompareAndSwapN, Op_ShenandoahWeakCompareAndSwapP, Op_ShenandoahWeakCompareAndSwapN); 1355 1356 } 1357 1358 bool ShenandoahBarrierSetC2::matcher_find_shared_post_visit(Matcher* matcher, Node* n, uint opcode) const { 1359 switch (opcode) { 1360 case Op_ShenandoahCompareAndExchangeP: 1361 case Op_ShenandoahCompareAndExchangeN: 1362 case Op_ShenandoahWeakCompareAndSwapP: 1363 case Op_ShenandoahWeakCompareAndSwapN: 1364 case Op_ShenandoahCompareAndSwapP: 1365 case Op_ShenandoahCompareAndSwapN: { // Convert trinary to binary-tree 1366 Node* newval = n->in(MemNode::ValueIn); 1367 Node* oldval = n->in(LoadStoreConditionalNode::ExpectedIn); 1368 Node* pair = new BinaryNode(oldval, newval); 1369 n->set_req(MemNode::ValueIn,pair); 1370 n->del_req(LoadStoreConditionalNode::ExpectedIn); 1371 return true; 1372 } 1373 default: 1374 break; 1375 } 1376 return false; 1377 } 1378 1379 bool ShenandoahBarrierSetC2::matcher_is_store_load_barrier(Node* x, uint xop) const { 1380 return xop == Op_ShenandoahCompareAndExchangeP || 1381 xop == Op_ShenandoahCompareAndExchangeN || 1382 xop == Op_ShenandoahWeakCompareAndSwapP || 1383 xop == Op_ShenandoahWeakCompareAndSwapN || 1384 xop == Op_ShenandoahCompareAndSwapN || 1385 xop == Op_ShenandoahCompareAndSwapP; 1386 }