1 /* 2 * Copyright (c) 2018, 2019, Red Hat, Inc. All rights reserved. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 * 22 */ 23 24 #include "precompiled.hpp" 25 #include "gc/shared/barrierSet.hpp" 26 #include "gc/shenandoah/shenandoahHeap.hpp" 27 #include "gc/shenandoah/shenandoahHeuristics.hpp" 28 #include "gc/shenandoah/shenandoahRuntime.hpp" 29 #include "gc/shenandoah/shenandoahThreadLocalData.hpp" 30 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp" 31 #include "gc/shenandoah/c2/shenandoahSupport.hpp" 32 #include "opto/graphKit.hpp" 33 #include "opto/idealKit.hpp" 34 #include "opto/macro.hpp" 35 36 ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() { 37 return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2()); 38 } 39 40 ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena) 41 : _shenandoah_barriers(new (comp_arena) GrowableArray<ShenandoahWriteBarrierNode*>(comp_arena, 8, 0, NULL)) { 42 } 43 44 int ShenandoahBarrierSetC2State::shenandoah_barriers_count() const { 45 return _shenandoah_barriers->length(); 46 } 47 48 ShenandoahWriteBarrierNode* ShenandoahBarrierSetC2State::shenandoah_barrier(int idx) const { 49 return _shenandoah_barriers->at(idx); 50 } 51 52 void ShenandoahBarrierSetC2State::add_shenandoah_barrier(ShenandoahWriteBarrierNode * n) { 53 assert(!_shenandoah_barriers->contains(n), "duplicate entry in barrier list"); 54 _shenandoah_barriers->append(n); 55 } 56 57 void ShenandoahBarrierSetC2State::remove_shenandoah_barrier(ShenandoahWriteBarrierNode * n) { 58 if (_shenandoah_barriers->contains(n)) { 59 _shenandoah_barriers->remove(n); 60 } 61 } 62 63 #define __ kit-> 64 65 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier(GraphKit* kit, Node* obj) const { 66 if (ShenandoahReadBarrier) { 67 obj = shenandoah_read_barrier_impl(kit, obj, false, true, true); 68 } 69 return obj; 70 } 71 72 Node* ShenandoahBarrierSetC2::shenandoah_storeval_barrier(GraphKit* kit, Node* obj) const { 73 if (ShenandoahStoreValEnqueueBarrier) { 74 obj = shenandoah_write_barrier(kit, obj); 75 obj = shenandoah_enqueue_barrier(kit, obj); 76 } 77 if (ShenandoahStoreValReadBarrier) { 78 obj = shenandoah_read_barrier_impl(kit, obj, true, false, false); 79 } 80 return obj; 81 } 82 83 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier_impl(GraphKit* kit, Node* obj, bool use_ctrl, bool use_mem, bool allow_fromspace) const { 84 const Type* obj_type = obj->bottom_type(); 85 if (obj_type->higher_equal(TypePtr::NULL_PTR)) { 86 return obj; 87 } 88 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type); 89 Node* mem = use_mem ? __ memory(adr_type) : __ immutable_memory(); 90 91 if (! ShenandoahBarrierNode::needs_barrier(&__ gvn(), NULL, obj, mem, allow_fromspace)) { 92 // We know it is null, no barrier needed. 93 return obj; 94 } 95 96 if (obj_type->meet(TypePtr::NULL_PTR) == obj_type->remove_speculative()) { 97 98 // We don't know if it's null or not. Need null-check. 99 enum { _not_null_path = 1, _null_path, PATH_LIMIT }; 100 RegionNode* region = new RegionNode(PATH_LIMIT); 101 Node* phi = new PhiNode(region, obj_type); 102 Node* null_ctrl = __ top(); 103 Node* not_null_obj = __ null_check_oop(obj, &null_ctrl); 104 105 region->init_req(_null_path, null_ctrl); 106 phi ->init_req(_null_path, __ zerocon(T_OBJECT)); 107 108 Node* ctrl = use_ctrl ? __ control() : NULL; 109 ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, not_null_obj, allow_fromspace); 110 Node* n = __ gvn().transform(rb); 111 112 region->init_req(_not_null_path, __ control()); 113 phi ->init_req(_not_null_path, n); 114 115 __ set_control(__ gvn().transform(region)); 116 __ record_for_igvn(region); 117 return __ gvn().transform(phi); 118 119 } else { 120 // We know it is not null. Simple barrier is sufficient. 121 Node* ctrl = use_ctrl ? __ control() : NULL; 122 ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, obj, allow_fromspace); 123 Node* n = __ gvn().transform(rb); 124 __ record_for_igvn(n); 125 return n; 126 } 127 } 128 129 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier_helper(GraphKit* kit, Node* obj, const TypePtr* adr_type) const { 130 ShenandoahWriteBarrierNode* wb = new ShenandoahWriteBarrierNode(kit->C, kit->control(), kit->memory(adr_type), obj); 131 Node* n = __ gvn().transform(wb); 132 if (n == wb) { // New barrier needs memory projection. 133 Node* proj = __ gvn().transform(new ShenandoahWBMemProjNode(n)); 134 __ set_memory(proj, adr_type); 135 } 136 return n; 137 } 138 139 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier(GraphKit* kit, Node* obj) const { 140 if (ShenandoahWriteBarrier) { 141 obj = shenandoah_write_barrier_impl(kit, obj); 142 } 143 return obj; 144 } 145 146 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier_impl(GraphKit* kit, Node* obj) const { 147 if (! ShenandoahBarrierNode::needs_barrier(&__ gvn(), NULL, obj, NULL, true)) { 148 return obj; 149 } 150 const Type* obj_type = obj->bottom_type(); 151 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type); 152 Node* n = shenandoah_write_barrier_helper(kit, obj, adr_type); 153 __ record_for_igvn(n); 154 return n; 155 } 156 157 bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr, 158 BasicType bt, uint adr_idx) const { 159 intptr_t offset = 0; 160 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset); 161 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase); 162 163 if (offset == Type::OffsetBot) { 164 return false; // cannot unalias unless there are precise offsets 165 } 166 167 if (alloc == NULL) { 168 return false; // No allocation found 169 } 170 171 intptr_t size_in_bytes = type2aelembytes(bt); 172 173 Node* mem = __ memory(adr_idx); // start searching here... 174 175 for (int cnt = 0; cnt < 50; cnt++) { 176 177 if (mem->is_Store()) { 178 179 Node* st_adr = mem->in(MemNode::Address); 180 intptr_t st_offset = 0; 181 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset); 182 183 if (st_base == NULL) { 184 break; // inscrutable pointer 185 } 186 187 // Break we have found a store with same base and offset as ours so break 188 if (st_base == base && st_offset == offset) { 189 break; 190 } 191 192 if (st_offset != offset && st_offset != Type::OffsetBot) { 193 const int MAX_STORE = BytesPerLong; 194 if (st_offset >= offset + size_in_bytes || 195 st_offset <= offset - MAX_STORE || 196 st_offset <= offset - mem->as_Store()->memory_size()) { 197 // Success: The offsets are provably independent. 198 // (You may ask, why not just test st_offset != offset and be done? 199 // The answer is that stores of different sizes can co-exist 200 // in the same sequence of RawMem effects. We sometimes initialize 201 // a whole 'tile' of array elements with a single jint or jlong.) 202 mem = mem->in(MemNode::Memory); 203 continue; // advance through independent store memory 204 } 205 } 206 207 if (st_base != base 208 && MemNode::detect_ptr_independence(base, alloc, st_base, 209 AllocateNode::Ideal_allocation(st_base, phase), 210 phase)) { 211 // Success: The bases are provably independent. 212 mem = mem->in(MemNode::Memory); 213 continue; // advance through independent store memory 214 } 215 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) { 216 217 InitializeNode* st_init = mem->in(0)->as_Initialize(); 218 AllocateNode* st_alloc = st_init->allocation(); 219 220 // Make sure that we are looking at the same allocation site. 221 // The alloc variable is guaranteed to not be null here from earlier check. 222 if (alloc == st_alloc) { 223 // Check that the initialization is storing NULL so that no previous store 224 // has been moved up and directly write a reference 225 Node* captured_store = st_init->find_captured_store(offset, 226 type2aelembytes(T_OBJECT), 227 phase); 228 if (captured_store == NULL || captured_store == st_init->zero_memory()) { 229 return true; 230 } 231 } 232 } 233 234 // Unless there is an explicit 'continue', we must bail out here, 235 // because 'mem' is an inscrutable memory state (e.g., a call). 236 break; 237 } 238 239 return false; 240 } 241 242 #undef __ 243 #define __ ideal. 244 245 void ShenandoahBarrierSetC2::satb_write_barrier_pre(GraphKit* kit, 246 bool do_load, 247 Node* obj, 248 Node* adr, 249 uint alias_idx, 250 Node* val, 251 const TypeOopPtr* val_type, 252 Node* pre_val, 253 BasicType bt) const { 254 // Some sanity checks 255 // Note: val is unused in this routine. 256 257 if (do_load) { 258 // We need to generate the load of the previous value 259 assert(obj != NULL, "must have a base"); 260 assert(adr != NULL, "where are loading from?"); 261 assert(pre_val == NULL, "loaded already?"); 262 assert(val_type != NULL, "need a type"); 263 264 if (ReduceInitialCardMarks 265 && satb_can_remove_pre_barrier(kit, &kit->gvn(), adr, bt, alias_idx)) { 266 return; 267 } 268 269 } else { 270 // In this case both val_type and alias_idx are unused. 271 assert(pre_val != NULL, "must be loaded already"); 272 // Nothing to be done if pre_val is null. 273 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return; 274 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here"); 275 } 276 assert(bt == T_OBJECT, "or we shouldn't be here"); 277 278 IdealKit ideal(kit, true); 279 280 Node* tls = __ thread(); // ThreadLocalStorage 281 282 Node* no_base = __ top(); 283 Node* zero = __ ConI(0); 284 Node* zeroX = __ ConX(0); 285 286 float likely = PROB_LIKELY(0.999); 287 float unlikely = PROB_UNLIKELY(0.999); 288 289 // Offsets into the thread 290 const int index_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset()); 291 const int buffer_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset()); 292 293 // Now the actual pointers into the thread 294 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset)); 295 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset)); 296 297 // Now some of the values 298 Node* marking; 299 Node* gc_state = __ AddP(no_base, tls, __ ConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset()))); 300 Node* ld = __ load(__ ctrl(), gc_state, TypeInt::BYTE, T_BYTE, Compile::AliasIdxRaw); 301 marking = __ AndI(ld, __ ConI(ShenandoahHeap::MARKING)); 302 assert(ShenandoahWriteBarrierNode::is_gc_state_load(ld), "Should match the shape"); 303 304 // if (!marking) 305 __ if_then(marking, BoolTest::ne, zero, unlikely); { 306 BasicType index_bt = TypeX_X->basic_type(); 307 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size."); 308 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw); 309 310 if (do_load) { 311 // load original value 312 // alias_idx correct?? 313 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx); 314 } 315 316 // if (pre_val != NULL) 317 __ if_then(pre_val, BoolTest::ne, kit->null()); { 318 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw); 319 320 // is the queue for this thread full? 321 __ if_then(index, BoolTest::ne, zeroX, likely); { 322 323 // decrement the index 324 Node* next_index = kit->gvn().transform(new SubXNode(index, __ ConX(sizeof(intptr_t)))); 325 326 // Now get the buffer location we will log the previous value into and store it 327 Node *log_addr = __ AddP(no_base, buffer, next_index); 328 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered); 329 // update the index 330 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered); 331 332 } __ else_(); { 333 334 // logging buffer is full, call the runtime 335 const TypeFunc *tf = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type(); 336 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), "shenandoah_wb_pre", pre_val, tls); 337 } __ end_if(); // (!index) 338 } __ end_if(); // (pre_val != NULL) 339 } __ end_if(); // (!marking) 340 341 // Final sync IdealKit and GraphKit. 342 kit->final_sync(ideal); 343 344 if (ShenandoahSATBBarrier && adr != NULL) { 345 Node* c = kit->control(); 346 Node* call = c->in(1)->in(1)->in(1)->in(0); 347 assert(is_shenandoah_wb_pre_call(call), "shenandoah_wb_pre call expected"); 348 call->add_req(adr); 349 } 350 } 351 352 bool ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(Node* call) { 353 return call->is_CallLeaf() && 354 call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry); 355 } 356 357 bool ShenandoahBarrierSetC2::is_shenandoah_wb_call(Node* call) { 358 return call->is_CallLeaf() && 359 call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_JRT); 360 } 361 362 bool ShenandoahBarrierSetC2::is_shenandoah_marking_if(PhaseTransform *phase, Node* n) { 363 if (n->Opcode() != Op_If) { 364 return false; 365 } 366 367 Node* bol = n->in(1); 368 assert(bol->is_Bool(), ""); 369 Node* cmpx = bol->in(1); 370 if (bol->as_Bool()->_test._test == BoolTest::ne && 371 cmpx->is_Cmp() && cmpx->in(2) == phase->intcon(0) && 372 is_shenandoah_state_load(cmpx->in(1)->in(1)) && 373 cmpx->in(1)->in(2)->is_Con() && 374 cmpx->in(1)->in(2) == phase->intcon(ShenandoahHeap::MARKING)) { 375 return true; 376 } 377 378 return false; 379 } 380 381 bool ShenandoahBarrierSetC2::is_shenandoah_state_load(Node* n) { 382 if (!n->is_Load()) return false; 383 const int state_offset = in_bytes(ShenandoahThreadLocalData::gc_state_offset()); 384 return n->in(2)->is_AddP() && n->in(2)->in(2)->Opcode() == Op_ThreadLocal 385 && n->in(2)->in(3)->is_Con() 386 && n->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == state_offset; 387 } 388 389 void ShenandoahBarrierSetC2::shenandoah_write_barrier_pre(GraphKit* kit, 390 bool do_load, 391 Node* obj, 392 Node* adr, 393 uint alias_idx, 394 Node* val, 395 const TypeOopPtr* val_type, 396 Node* pre_val, 397 BasicType bt) const { 398 if (ShenandoahSATBBarrier) { 399 IdealKit ideal(kit); 400 kit->sync_kit(ideal); 401 402 satb_write_barrier_pre(kit, do_load, obj, adr, alias_idx, val, val_type, pre_val, bt); 403 404 ideal.sync_kit(kit); 405 kit->final_sync(ideal); 406 } 407 } 408 409 Node* ShenandoahBarrierSetC2::shenandoah_enqueue_barrier(GraphKit* kit, Node* pre_val) const { 410 return kit->gvn().transform(new ShenandoahEnqueueBarrierNode(pre_val)); 411 } 412 413 // Helper that guards and inserts a pre-barrier. 414 void ShenandoahBarrierSetC2::insert_pre_barrier(GraphKit* kit, Node* base_oop, Node* offset, 415 Node* pre_val, bool need_mem_bar) const { 416 // We could be accessing the referent field of a reference object. If so, when G1 417 // is enabled, we need to log the value in the referent field in an SATB buffer. 418 // This routine performs some compile time filters and generates suitable 419 // runtime filters that guard the pre-barrier code. 420 // Also add memory barrier for non volatile load from the referent field 421 // to prevent commoning of loads across safepoint. 422 423 // Some compile time checks. 424 425 // If offset is a constant, is it java_lang_ref_Reference::_reference_offset? 426 const TypeX* otype = offset->find_intptr_t_type(); 427 if (otype != NULL && otype->is_con() && 428 otype->get_con() != java_lang_ref_Reference::referent_offset) { 429 // Constant offset but not the reference_offset so just return 430 return; 431 } 432 433 // We only need to generate the runtime guards for instances. 434 const TypeOopPtr* btype = base_oop->bottom_type()->isa_oopptr(); 435 if (btype != NULL) { 436 if (btype->isa_aryptr()) { 437 // Array type so nothing to do 438 return; 439 } 440 441 const TypeInstPtr* itype = btype->isa_instptr(); 442 if (itype != NULL) { 443 // Can the klass of base_oop be statically determined to be 444 // _not_ a sub-class of Reference and _not_ Object? 445 ciKlass* klass = itype->klass(); 446 if ( klass->is_loaded() && 447 !klass->is_subtype_of(kit->env()->Reference_klass()) && 448 !kit->env()->Object_klass()->is_subtype_of(klass)) { 449 return; 450 } 451 } 452 } 453 454 // The compile time filters did not reject base_oop/offset so 455 // we need to generate the following runtime filters 456 // 457 // if (offset == java_lang_ref_Reference::_reference_offset) { 458 // if (instance_of(base, java.lang.ref.Reference)) { 459 // pre_barrier(_, pre_val, ...); 460 // } 461 // } 462 463 float likely = PROB_LIKELY( 0.999); 464 float unlikely = PROB_UNLIKELY(0.999); 465 466 IdealKit ideal(kit); 467 468 Node* referent_off = __ ConX(java_lang_ref_Reference::referent_offset); 469 470 __ if_then(offset, BoolTest::eq, referent_off, unlikely); { 471 // Update graphKit memory and control from IdealKit. 472 kit->sync_kit(ideal); 473 474 Node* ref_klass_con = kit->makecon(TypeKlassPtr::make(kit->env()->Reference_klass())); 475 Node* is_instof = kit->gen_instanceof(base_oop, ref_klass_con); 476 477 // Update IdealKit memory and control from graphKit. 478 __ sync_kit(kit); 479 480 Node* one = __ ConI(1); 481 // is_instof == 0 if base_oop == NULL 482 __ if_then(is_instof, BoolTest::eq, one, unlikely); { 483 484 // Update graphKit from IdeakKit. 485 kit->sync_kit(ideal); 486 487 // Use the pre-barrier to record the value in the referent field 488 satb_write_barrier_pre(kit, false /* do_load */, 489 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */, 490 pre_val /* pre_val */, 491 T_OBJECT); 492 if (need_mem_bar) { 493 // Add memory barrier to prevent commoning reads from this field 494 // across safepoint since GC can change its value. 495 kit->insert_mem_bar(Op_MemBarCPUOrder); 496 } 497 // Update IdealKit from graphKit. 498 __ sync_kit(kit); 499 500 } __ end_if(); // _ref_type != ref_none 501 } __ end_if(); // offset == referent_offset 502 503 // Final sync IdealKit and GraphKit. 504 kit->final_sync(ideal); 505 } 506 507 #undef __ 508 509 const TypeFunc* ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type() { 510 const Type **fields = TypeTuple::fields(2); 511 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value 512 fields[TypeFunc::Parms+1] = TypeRawPtr::NOTNULL; // thread 513 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields); 514 515 // create result type (range) 516 fields = TypeTuple::fields(0); 517 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields); 518 519 return TypeFunc::make(domain, range); 520 } 521 522 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type() { 523 const Type **fields = TypeTuple::fields(1); 524 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value 525 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields); 526 527 // create result type (range) 528 fields = TypeTuple::fields(0); 529 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields); 530 531 return TypeFunc::make(domain, range); 532 } 533 534 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_write_barrier_Type() { 535 const Type **fields = TypeTuple::fields(1); 536 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value 537 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields); 538 539 // create result type (range) 540 fields = TypeTuple::fields(1); 541 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; 542 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields); 543 544 return TypeFunc::make(domain, range); 545 } 546 547 Node* ShenandoahBarrierSetC2::store_at(C2Access& access, C2AccessValue& val) const { 548 // TODO: Implement using proper barriers. 549 return BarrierSetC2::store_at(access, val); 550 } 551 552 Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const { 553 DecoratorSet decorators = access.decorators(); 554 GraphKit* kit = access.kit(); 555 556 const TypePtr* adr_type = access.addr().type(); 557 Node* adr = access.addr().node(); 558 559 bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0; 560 bool on_heap = (decorators & IN_HEAP) != 0; 561 562 if (!access.is_oop() || (!on_heap && !anonymous)) { 563 return BarrierSetC2::store_at_resolved(access, val); 564 } 565 566 uint adr_idx = kit->C->get_alias_index(adr_type); 567 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" ); 568 Node* value = val.node(); 569 value = shenandoah_storeval_barrier(kit, value); 570 val.set_node(value); 571 shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(), 572 static_cast<const TypeOopPtr*>(val.type()), NULL /* pre_val */, access.type()); 573 return BarrierSetC2::store_at_resolved(access, val); 574 } 575 576 Node* ShenandoahBarrierSetC2::load_at(C2Access& access, const Type* val_type) const { 577 // TODO: Implement using proper barriers. 578 return BarrierSetC2::load_at(access, val_type); 579 } 580 581 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const { 582 DecoratorSet decorators = access.decorators(); 583 GraphKit* kit = access.kit(); 584 585 Node* adr = access.addr().node(); 586 Node* obj = access.base(); 587 588 bool mismatched = (decorators & C2_MISMATCHED) != 0; 589 bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0; 590 bool on_heap = (decorators & IN_HEAP) != 0; 591 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0; 592 bool is_unordered = (decorators & MO_UNORDERED) != 0; 593 bool need_cpu_mem_bar = !is_unordered || mismatched || !on_heap; 594 595 Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : kit->top(); 596 Node* load = BarrierSetC2::load_at_resolved(access, val_type); 597 598 // If we are reading the value of the referent field of a Reference 599 // object (either by using Unsafe directly or through reflection) 600 // then, if SATB is enabled, we need to record the referent in an 601 // SATB log buffer using the pre-barrier mechanism. 602 // Also we need to add memory barrier to prevent commoning reads 603 // from this field across safepoint since GC can change its value. 604 bool need_read_barrier = ShenandoahKeepAliveBarrier && 605 (on_heap && (on_weak || (unknown && offset != kit->top() && obj != kit->top()))); 606 607 if (!access.is_oop() || !need_read_barrier) { 608 return load; 609 } 610 611 if (on_weak) { 612 // Use the pre-barrier to record the value in the referent field 613 satb_write_barrier_pre(kit, false /* do_load */, 614 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */, 615 load /* pre_val */, T_OBJECT); 616 // Add memory barrier to prevent commoning reads from this field 617 // across safepoint since GC can change its value. 618 kit->insert_mem_bar(Op_MemBarCPUOrder); 619 } else if (unknown) { 620 // We do not require a mem bar inside pre_barrier if need_mem_bar 621 // is set: the barriers would be emitted by us. 622 insert_pre_barrier(kit, obj, offset, load, !need_cpu_mem_bar); 623 } 624 625 return load; 626 } 627 628 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicAccess& access, Node* expected_val, 629 Node* val, const Type* value_type) const { 630 GraphKit* kit = access.kit(); 631 if (access.is_oop()) { 632 val = shenandoah_storeval_barrier(kit, val); 633 shenandoah_write_barrier_pre(kit, false /* do_load */, 634 NULL, NULL, max_juint, NULL, NULL, 635 expected_val /* pre_val */, T_OBJECT); 636 637 } 638 return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, val, value_type); 639 } 640 641 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at(C2AtomicAccess& access, Node* expected_val, 642 Node* new_val, const Type* val_type) const { 643 // TODO: Implement using proper barriers. 644 return BarrierSetC2::atomic_cmpxchg_val_at(access, expected_val, new_val, val_type); 645 } 646 647 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicAccess& access, Node* expected_val, 648 Node* val, const Type* value_type) const { 649 GraphKit* kit = access.kit(); 650 if (access.is_oop()) { 651 val = shenandoah_storeval_barrier(kit, val); 652 shenandoah_write_barrier_pre(kit, false /* do_load */, 653 NULL, NULL, max_juint, NULL, NULL, 654 expected_val /* pre_val */, T_OBJECT); 655 } 656 return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, val, value_type); 657 } 658 659 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at(C2AtomicAccess& access, Node* expected_val, 660 Node* new_val, const Type* val_type) const { 661 // TODO: Implement using proper barriers. 662 return BarrierSetC2::atomic_cmpxchg_bool_at(access, expected_val, new_val, val_type); 663 } 664 665 Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicAccess& access, Node* val, const Type* value_type) const { 666 GraphKit* kit = access.kit(); 667 if (access.is_oop()) { 668 val = shenandoah_storeval_barrier(kit, val); 669 } 670 Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type); 671 if (access.is_oop()) { 672 shenandoah_write_barrier_pre(kit, false /* do_load */, 673 NULL, NULL, max_juint, NULL, NULL, 674 result /* pre_val */, T_OBJECT); 675 } 676 return result; 677 } 678 679 Node* ShenandoahBarrierSetC2::atomic_xchg_at(C2AtomicAccess& access, Node* new_val, const Type* value_type) const { 680 // TODO: Implement using proper barriers. 681 return BarrierSetC2::atomic_xchg_at(access, new_val, value_type); 682 } 683 684 Node* ShenandoahBarrierSetC2::atomic_add_at(C2AtomicAccess& access, Node* new_val, const Type* value_type) const { 685 // TODO: Implement using proper barriers. 686 return BarrierSetC2::atomic_add_at(access, new_val, value_type); 687 } 688 689 void ShenandoahBarrierSetC2::clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const { 690 // TODO: Implement using proper barriers. 691 BarrierSetC2::clone(kit, src, dst, size, is_array); 692 } 693 694 Node* ShenandoahBarrierSetC2::resolve_for_read(GraphKit* kit, Node* n) const { 695 return shenandoah_read_barrier(kit, n); 696 } 697 698 Node* ShenandoahBarrierSetC2::resolve_for_write(GraphKit* kit, Node* n) const { 699 return shenandoah_write_barrier(kit, n); 700 } 701 702 // Support for GC barriers emitted during parsing 703 bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const { 704 if (node->Opcode() != Op_CallLeaf && node->Opcode() != Op_CallLeafNoFP) { 705 return false; 706 } 707 CallLeafNode *call = node->as_CallLeaf(); 708 if (call->_name == NULL) { 709 return false; 710 } 711 712 return strcmp(call->_name, "shenandoah_clone_barrier") == 0 || 713 strcmp(call->_name, "shenandoah_cas_obj") == 0 || 714 strcmp(call->_name, "shenandoah_wb_pre") == 0; 715 } 716 717 Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const { 718 return ShenandoahBarrierNode::skip_through_barrier(c); 719 } 720 721 bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(BasicType type) const { 722 return false; 723 } 724 725 // Support for macro expanded GC barriers 726 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const { 727 if (node->Opcode() == Op_ShenandoahWriteBarrier) { 728 state()->add_shenandoah_barrier((ShenandoahWriteBarrierNode*) node); 729 } 730 } 731 732 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const { 733 if (node->Opcode() == Op_ShenandoahWriteBarrier) { 734 state()->remove_shenandoah_barrier((ShenandoahWriteBarrierNode*) node); 735 } 736 } 737 738 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* n) const { 739 if (is_shenandoah_wb_pre_call(n)) { 740 shenandoah_eliminate_wb_pre(n, ¯o->igvn()); 741 } 742 } 743 744 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const { 745 assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), ""); 746 Node* c = call->as_Call()->proj_out(TypeFunc::Control); 747 c = c->unique_ctrl_out(); 748 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); 749 c = c->unique_ctrl_out(); 750 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); 751 Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0); 752 assert(iff->is_If(), "expect test"); 753 if (!is_shenandoah_marking_if(igvn, iff)) { 754 c = c->unique_ctrl_out(); 755 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?"); 756 iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0); 757 assert(is_shenandoah_marking_if(igvn, iff), "expect marking test"); 758 } 759 Node* cmpx = iff->in(1)->in(1); 760 igvn->replace_node(cmpx, igvn->makecon(TypeInt::CC_EQ)); 761 igvn->rehash_node_delayed(call); 762 call->del_req(call->req()-1); 763 } 764 765 void ShenandoahBarrierSetC2::enqueue_useful_gc_barrier(Unique_Node_List &worklist, Node* node) const { 766 } 767 768 void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful) const { 769 for (int i = state()->shenandoah_barriers_count()-1; i >= 0; i--) { 770 ShenandoahWriteBarrierNode* n = state()->shenandoah_barrier(i); 771 if (!useful.member(n)) { 772 state()->remove_shenandoah_barrier(n); 773 } 774 } 775 776 } 777 778 void ShenandoahBarrierSetC2::add_users_to_worklist(Unique_Node_List* worklist) const {} 779 780 void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const { 781 return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena); 782 } 783 784 ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const { 785 return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state()); 786 } 787 788 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be 789 // expanded later, then now is the time to do so. 790 bool ShenandoahBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { return false; } 791 void ShenandoahBarrierSetC2::verify_gc_barriers(bool post_parse) const { 792 #ifdef ASSERT 793 if (ShenandoahVerifyOptoBarriers && !post_parse) { 794 ShenandoahBarrierNode::verify(Compile::current()->root()); 795 } 796 #endif 797 } 798 799 Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN *phase, Node* n, bool can_reshape) const { 800 if (is_shenandoah_wb_pre_call(n)) { 801 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt(); 802 if (n->req() > cnt) { 803 Node* addp = n->in(cnt); 804 if (has_only_shenandoah_wb_pre_uses(addp)) { 805 n->del_req(cnt); 806 if (can_reshape) { 807 phase->is_IterGVN()->_worklist.push(addp); 808 } 809 return n; 810 } 811 } 812 } 813 return NULL; 814 } 815 816 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) { 817 if (!UseShenandoahGC) { 818 return false; 819 } 820 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { 821 Node* u = n->fast_out(i); 822 if (!is_shenandoah_wb_pre_call(u)) { 823 return false; 824 } 825 } 826 return n->outcnt() > 0; 827 }