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/shenandoahForwarding.hpp"
27 #include "gc/shenandoah/shenandoahHeap.hpp"
28 #include "gc/shenandoah/shenandoahHeuristics.hpp"
29 #include "gc/shenandoah/shenandoahRuntime.hpp"
30 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
31 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
32 #include "gc/shenandoah/c2/shenandoahSupport.hpp"
33 #include "opto/arraycopynode.hpp"
34 #include "opto/escape.hpp"
35 #include "opto/graphKit.hpp"
36 #include "opto/idealKit.hpp"
37 #include "opto/macro.hpp"
38 #include "opto/movenode.hpp"
39 #include "opto/narrowptrnode.hpp"
40 #include "opto/rootnode.hpp"
41
42 ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() {
43 return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2());
44 }
45
46 ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena)
47 : _enqueue_barriers(new (comp_arena) GrowableArray<ShenandoahEnqueueBarrierNode*>(comp_arena, 8, 0, NULL)),
48 _load_reference_barriers(new (comp_arena) GrowableArray<ShenandoahLoadReferenceBarrierNode*>(comp_arena, 8, 0, NULL)) {
49 }
50
51 int ShenandoahBarrierSetC2State::enqueue_barriers_count() const {
52 return _enqueue_barriers->length();
53 }
54
55 ShenandoahEnqueueBarrierNode* ShenandoahBarrierSetC2State::enqueue_barrier(int idx) const {
56 return _enqueue_barriers->at(idx);
57 }
58
59 void ShenandoahBarrierSetC2State::add_enqueue_barrier(ShenandoahEnqueueBarrierNode * n) {
60 assert(!_enqueue_barriers->contains(n), "duplicate entry in barrier list");
61 _enqueue_barriers->append(n);
62 }
63
64 void ShenandoahBarrierSetC2State::remove_enqueue_barrier(ShenandoahEnqueueBarrierNode * n) {
65 if (_enqueue_barriers->contains(n)) {
66 _enqueue_barriers->remove(n);
67 }
68 }
69
70 int ShenandoahBarrierSetC2State::load_reference_barriers_count() const {
71 return _load_reference_barriers->length();
72 }
73
74 ShenandoahLoadReferenceBarrierNode* ShenandoahBarrierSetC2State::load_reference_barrier(int idx) const {
75 return _load_reference_barriers->at(idx);
76 }
77
78 void ShenandoahBarrierSetC2State::add_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) {
79 assert(!_load_reference_barriers->contains(n), "duplicate entry in barrier list");
80 _load_reference_barriers->append(n);
81 }
82
83 void ShenandoahBarrierSetC2State::remove_load_reference_barrier(ShenandoahLoadReferenceBarrierNode * n) {
84 if (_load_reference_barriers->contains(n)) {
85 _load_reference_barriers->remove(n);
86 }
87 }
88
89 Node* ShenandoahBarrierSetC2::shenandoah_storeval_barrier(GraphKit* kit, Node* obj) const {
90 if (ShenandoahStoreValEnqueueBarrier) {
91 obj = shenandoah_enqueue_barrier(kit, obj);
92 }
93 return obj;
94 }
95
96 #define __ kit->
97
98 bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr,
99 BasicType bt, uint adr_idx) const {
100 intptr_t offset = 0;
101 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
102 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
103
104 if (offset == Type::OffsetBot) {
105 return false; // cannot unalias unless there are precise offsets
106 }
107
108 if (alloc == NULL) {
109 return false; // No allocation found
110 }
111
112 intptr_t size_in_bytes = type2aelembytes(bt);
113
114 Node* mem = __ memory(adr_idx); // start searching here...
115
116 for (int cnt = 0; cnt < 50; cnt++) {
117
118 if (mem->is_Store()) {
119
120 Node* st_adr = mem->in(MemNode::Address);
121 intptr_t st_offset = 0;
122 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
123
124 if (st_base == NULL) {
125 break; // inscrutable pointer
126 }
127
128 // Break we have found a store with same base and offset as ours so break
129 if (st_base == base && st_offset == offset) {
130 break;
131 }
132
133 if (st_offset != offset && st_offset != Type::OffsetBot) {
134 const int MAX_STORE = BytesPerLong;
135 if (st_offset >= offset + size_in_bytes ||
136 st_offset <= offset - MAX_STORE ||
137 st_offset <= offset - mem->as_Store()->memory_size()) {
138 // Success: The offsets are provably independent.
139 // (You may ask, why not just test st_offset != offset and be done?
140 // The answer is that stores of different sizes can co-exist
141 // in the same sequence of RawMem effects. We sometimes initialize
142 // a whole 'tile' of array elements with a single jint or jlong.)
143 mem = mem->in(MemNode::Memory);
144 continue; // advance through independent store memory
145 }
146 }
147
148 if (st_base != base
149 && MemNode::detect_ptr_independence(base, alloc, st_base,
150 AllocateNode::Ideal_allocation(st_base, phase),
151 phase)) {
152 // Success: The bases are provably independent.
153 mem = mem->in(MemNode::Memory);
154 continue; // advance through independent store memory
155 }
156 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
157
158 InitializeNode* st_init = mem->in(0)->as_Initialize();
159 AllocateNode* st_alloc = st_init->allocation();
160
161 // Make sure that we are looking at the same allocation site.
162 // The alloc variable is guaranteed to not be null here from earlier check.
163 if (alloc == st_alloc) {
164 // Check that the initialization is storing NULL so that no previous store
165 // has been moved up and directly write a reference
166 Node* captured_store = st_init->find_captured_store(offset,
167 type2aelembytes(T_OBJECT),
168 phase);
169 if (captured_store == NULL || captured_store == st_init->zero_memory()) {
170 return true;
171 }
172 }
173 }
174
175 // Unless there is an explicit 'continue', we must bail out here,
176 // because 'mem' is an inscrutable memory state (e.g., a call).
177 break;
178 }
179
180 return false;
181 }
182
183 #undef __
184 #define __ ideal.
185
186 void ShenandoahBarrierSetC2::satb_write_barrier_pre(GraphKit* kit,
187 bool do_load,
188 Node* obj,
189 Node* adr,
190 uint alias_idx,
191 Node* val,
192 const TypeOopPtr* val_type,
193 Node* pre_val,
194 BasicType bt) const {
195 // Some sanity checks
196 // Note: val is unused in this routine.
197
198 if (do_load) {
199 // We need to generate the load of the previous value
200 assert(obj != NULL, "must have a base");
201 assert(adr != NULL, "where are loading from?");
202 assert(pre_val == NULL, "loaded already?");
203 assert(val_type != NULL, "need a type");
204
205 if (ReduceInitialCardMarks
206 && satb_can_remove_pre_barrier(kit, &kit->gvn(), adr, bt, alias_idx)) {
207 return;
208 }
209
210 } else {
211 // In this case both val_type and alias_idx are unused.
212 assert(pre_val != NULL, "must be loaded already");
213 // Nothing to be done if pre_val is null.
214 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
215 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
216 }
217 assert(bt == T_OBJECT, "or we shouldn't be here");
218
219 IdealKit ideal(kit, true);
220
221 Node* tls = __ thread(); // ThreadLocalStorage
222
223 Node* no_base = __ top();
224 Node* zero = __ ConI(0);
225 Node* zeroX = __ ConX(0);
226
227 float likely = PROB_LIKELY(0.999);
228 float unlikely = PROB_UNLIKELY(0.999);
229
230 // Offsets into the thread
231 const int index_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset());
232 const int buffer_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset());
233
234 // Now the actual pointers into the thread
235 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
236 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
237
238 // Now some of the values
239 Node* marking;
240 Node* gc_state = __ AddP(no_base, tls, __ ConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset())));
241 Node* ld = __ load(__ ctrl(), gc_state, TypeInt::BYTE, T_BYTE, Compile::AliasIdxRaw);
242 marking = __ AndI(ld, __ ConI(ShenandoahHeap::MARKING));
243 assert(ShenandoahBarrierC2Support::is_gc_state_load(ld), "Should match the shape");
244
245 // if (!marking)
246 __ if_then(marking, BoolTest::ne, zero, unlikely); {
247 BasicType index_bt = TypeX_X->basic_type();
248 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
249 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
250
251 if (do_load) {
252 // load original value
253 // alias_idx correct??
254 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
255 }
256
257 // if (pre_val != NULL)
258 __ if_then(pre_val, BoolTest::ne, kit->null()); {
259 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
260
261 // is the queue for this thread full?
262 __ if_then(index, BoolTest::ne, zeroX, likely); {
263
264 // decrement the index
265 Node* next_index = kit->gvn().transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
266
267 // Now get the buffer location we will log the previous value into and store it
268 Node *log_addr = __ AddP(no_base, buffer, next_index);
269 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
270 // update the index
271 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
272
273 } __ else_(); {
274
275 // logging buffer is full, call the runtime
276 const TypeFunc *tf = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type();
277 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), "shenandoah_wb_pre", pre_val, tls);
278 } __ end_if(); // (!index)
279 } __ end_if(); // (pre_val != NULL)
280 } __ end_if(); // (!marking)
281
282 // Final sync IdealKit and GraphKit.
283 kit->final_sync(ideal);
284
285 if (ShenandoahSATBBarrier && adr != NULL) {
286 Node* c = kit->control();
287 Node* call = c->in(1)->in(1)->in(1)->in(0);
288 assert(is_shenandoah_wb_pre_call(call), "shenandoah_wb_pre call expected");
289 call->add_req(adr);
290 }
291 }
292
293 bool ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(Node* call) {
294 return call->is_CallLeaf() &&
295 call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry);
296 }
297
298 bool ShenandoahBarrierSetC2::is_shenandoah_lrb_call(Node* call) {
299 return call->is_CallLeaf() &&
300 call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier);
301 }
302
303 bool ShenandoahBarrierSetC2::is_shenandoah_marking_if(PhaseTransform *phase, Node* n) {
304 if (n->Opcode() != Op_If) {
305 return false;
306 }
307
308 Node* bol = n->in(1);
309 assert(bol->is_Bool(), "");
310 Node* cmpx = bol->in(1);
311 if (bol->as_Bool()->_test._test == BoolTest::ne &&
312 cmpx->is_Cmp() && cmpx->in(2) == phase->intcon(0) &&
313 is_shenandoah_state_load(cmpx->in(1)->in(1)) &&
314 cmpx->in(1)->in(2)->is_Con() &&
315 cmpx->in(1)->in(2) == phase->intcon(ShenandoahHeap::MARKING)) {
316 return true;
317 }
318
319 return false;
320 }
321
322 bool ShenandoahBarrierSetC2::is_shenandoah_state_load(Node* n) {
323 if (!n->is_Load()) return false;
324 const int state_offset = in_bytes(ShenandoahThreadLocalData::gc_state_offset());
325 return n->in(2)->is_AddP() && n->in(2)->in(2)->Opcode() == Op_ThreadLocal
326 && n->in(2)->in(3)->is_Con()
327 && n->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == state_offset;
328 }
329
330 void ShenandoahBarrierSetC2::shenandoah_write_barrier_pre(GraphKit* kit,
331 bool do_load,
332 Node* obj,
333 Node* adr,
334 uint alias_idx,
335 Node* val,
336 const TypeOopPtr* val_type,
337 Node* pre_val,
338 BasicType bt) const {
339 if (ShenandoahSATBBarrier) {
340 IdealKit ideal(kit);
341 kit->sync_kit(ideal);
342
343 satb_write_barrier_pre(kit, do_load, obj, adr, alias_idx, val, val_type, pre_val, bt);
344
345 ideal.sync_kit(kit);
346 kit->final_sync(ideal);
347 }
348 }
349
350 Node* ShenandoahBarrierSetC2::shenandoah_enqueue_barrier(GraphKit* kit, Node* pre_val) const {
351 return kit->gvn().transform(new ShenandoahEnqueueBarrierNode(pre_val));
352 }
353
354 // Helper that guards and inserts a pre-barrier.
355 void ShenandoahBarrierSetC2::insert_pre_barrier(GraphKit* kit, Node* base_oop, Node* offset,
356 Node* pre_val, bool need_mem_bar) const {
357 // We could be accessing the referent field of a reference object. If so, when G1
358 // is enabled, we need to log the value in the referent field in an SATB buffer.
359 // This routine performs some compile time filters and generates suitable
360 // runtime filters that guard the pre-barrier code.
361 // Also add memory barrier for non volatile load from the referent field
362 // to prevent commoning of loads across safepoint.
363
364 // Some compile time checks.
365
366 // If offset is a constant, is it java_lang_ref_Reference::_reference_offset?
367 const TypeX* otype = offset->find_intptr_t_type();
368 if (otype != NULL && otype->is_con() &&
369 otype->get_con() != java_lang_ref_Reference::referent_offset) {
370 // Constant offset but not the reference_offset so just return
371 return;
372 }
373
374 // We only need to generate the runtime guards for instances.
375 const TypeOopPtr* btype = base_oop->bottom_type()->isa_oopptr();
376 if (btype != NULL) {
377 if (btype->isa_aryptr()) {
378 // Array type so nothing to do
379 return;
380 }
381
382 const TypeInstPtr* itype = btype->isa_instptr();
383 if (itype != NULL) {
384 // Can the klass of base_oop be statically determined to be
385 // _not_ a sub-class of Reference and _not_ Object?
386 ciKlass* klass = itype->klass();
387 if ( klass->is_loaded() &&
388 !klass->is_subtype_of(kit->env()->Reference_klass()) &&
389 !kit->env()->Object_klass()->is_subtype_of(klass)) {
390 return;
391 }
392 }
393 }
394
395 // The compile time filters did not reject base_oop/offset so
396 // we need to generate the following runtime filters
397 //
398 // if (offset == java_lang_ref_Reference::_reference_offset) {
399 // if (instance_of(base, java.lang.ref.Reference)) {
400 // pre_barrier(_, pre_val, ...);
401 // }
402 // }
403
404 float likely = PROB_LIKELY( 0.999);
405 float unlikely = PROB_UNLIKELY(0.999);
406
407 IdealKit ideal(kit);
408
409 Node* referent_off = __ ConX(java_lang_ref_Reference::referent_offset);
410
411 __ if_then(offset, BoolTest::eq, referent_off, unlikely); {
412 // Update graphKit memory and control from IdealKit.
413 kit->sync_kit(ideal);
414
415 Node* ref_klass_con = kit->makecon(TypeKlassPtr::make(kit->env()->Reference_klass()));
416 Node* is_instof = kit->gen_instanceof(base_oop, ref_klass_con);
417
418 // Update IdealKit memory and control from graphKit.
419 __ sync_kit(kit);
420
421 Node* one = __ ConI(1);
422 // is_instof == 0 if base_oop == NULL
423 __ if_then(is_instof, BoolTest::eq, one, unlikely); {
424
425 // Update graphKit from IdeakKit.
426 kit->sync_kit(ideal);
427
428 // Use the pre-barrier to record the value in the referent field
429 satb_write_barrier_pre(kit, false /* do_load */,
430 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */,
431 pre_val /* pre_val */,
432 T_OBJECT);
433 if (need_mem_bar) {
434 // Add memory barrier to prevent commoning reads from this field
435 // across safepoint since GC can change its value.
436 kit->insert_mem_bar(Op_MemBarCPUOrder);
437 }
438 // Update IdealKit from graphKit.
439 __ sync_kit(kit);
440
441 } __ end_if(); // _ref_type != ref_none
442 } __ end_if(); // offset == referent_offset
443
444 // Final sync IdealKit and GraphKit.
445 kit->final_sync(ideal);
446 }
447
448 #undef __
449
450 const TypeFunc* ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type() {
451 const Type **fields = TypeTuple::fields(2);
452 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
453 fields[TypeFunc::Parms+1] = TypeRawPtr::NOTNULL; // thread
454 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields);
455
456 // create result type (range)
457 fields = TypeTuple::fields(0);
458 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields);
459
460 return TypeFunc::make(domain, range);
461 }
462
463 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type() {
464 const Type **fields = TypeTuple::fields(3);
465 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // src
466 fields[TypeFunc::Parms+1] = TypeInstPtr::NOTNULL; // dst
467 fields[TypeFunc::Parms+2] = TypeInt::INT; // length
468 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+3, fields);
469
470 // create result type (range)
471 fields = TypeTuple::fields(0);
472 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields);
473
474 return TypeFunc::make(domain, range);
475 }
476
477 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_load_reference_barrier_Type() {
478 const Type **fields = TypeTuple::fields(1);
479 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
480 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields);
481
482 // create result type (range)
483 fields = TypeTuple::fields(1);
484 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL;
485 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields);
486
487 return TypeFunc::make(domain, range);
488 }
489
490 Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const {
491 DecoratorSet decorators = access.decorators();
492
493 const TypePtr* adr_type = access.addr().type();
494 Node* adr = access.addr().node();
495
496 bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
497 bool on_heap = (decorators & IN_HEAP) != 0;
498
499 if (!access.is_oop() || (!on_heap && !anonymous)) {
500 return BarrierSetC2::store_at_resolved(access, val);
501 }
502
503 if (access.is_parse_access()) {
504 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
505 GraphKit* kit = parse_access.kit();
506
507 uint adr_idx = kit->C->get_alias_index(adr_type);
508 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
509 Node* value = val.node();
510 value = shenandoah_storeval_barrier(kit, value);
511 val.set_node(value);
512 shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(),
513 static_cast<const TypeOopPtr*>(val.type()), NULL /* pre_val */, access.type());
514 } else {
515 assert(access.is_opt_access(), "only for optimization passes");
516 assert(((decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0 || !ShenandoahSATBBarrier) && (decorators & C2_ARRAY_COPY) != 0, "unexpected caller of this code");
517 C2OptAccess& opt_access = static_cast<C2OptAccess&>(access);
518 PhaseGVN& gvn = opt_access.gvn();
519 MergeMemNode* mm = opt_access.mem();
520
521 if (ShenandoahStoreValEnqueueBarrier) {
522 Node* enqueue = gvn.transform(new ShenandoahEnqueueBarrierNode(val.node()));
523 val.set_node(enqueue);
524 }
525 }
526 return BarrierSetC2::store_at_resolved(access, val);
527 }
528
529 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
530 DecoratorSet decorators = access.decorators();
531
532 Node* adr = access.addr().node();
533 Node* obj = access.base();
534
535 bool mismatched = (decorators & C2_MISMATCHED) != 0;
536 bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0;
537 bool on_heap = (decorators & IN_HEAP) != 0;
538 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
539 bool is_unordered = (decorators & MO_UNORDERED) != 0;
540 bool need_cpu_mem_bar = !is_unordered || mismatched || !on_heap;
541
542 Node* top = Compile::current()->top();
543
544 Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : top;
545 Node* load = BarrierSetC2::load_at_resolved(access, val_type);
546
547 if (access.is_oop()) {
548 if (ShenandoahLoadRefBarrier) {
549 load = new ShenandoahLoadReferenceBarrierNode(NULL, load, (decorators & IN_NATIVE) != 0);
550 if (access.is_parse_access()) {
551 load = static_cast<C2ParseAccess &>(access).kit()->gvn().transform(load);
552 } else {
553 load = static_cast<C2OptAccess &>(access).gvn().transform(load);
554 }
555 }
556 }
557
558 // If we are reading the value of the referent field of a Reference
559 // object (either by using Unsafe directly or through reflection)
560 // then, if SATB is enabled, we need to record the referent in an
561 // SATB log buffer using the pre-barrier mechanism.
562 // Also we need to add memory barrier to prevent commoning reads
563 // from this field across safepoint since GC can change its value.
564 bool need_read_barrier = ShenandoahKeepAliveBarrier &&
565 (on_heap && (on_weak || (unknown && offset != top && obj != top)));
566
567 if (!access.is_oop() || !need_read_barrier) {
568 return load;
569 }
570
571 assert(access.is_parse_access(), "entry not supported at optimization time");
572 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
573 GraphKit* kit = parse_access.kit();
574
575 if (on_weak) {
576 // Use the pre-barrier to record the value in the referent field
577 satb_write_barrier_pre(kit, false /* do_load */,
578 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */,
579 load /* pre_val */, T_OBJECT);
580 // Add memory barrier to prevent commoning reads from this field
581 // across safepoint since GC can change its value.
582 kit->insert_mem_bar(Op_MemBarCPUOrder);
583 } else if (unknown) {
584 // We do not require a mem bar inside pre_barrier if need_mem_bar
585 // is set: the barriers would be emitted by us.
586 insert_pre_barrier(kit, obj, offset, load, !need_cpu_mem_bar);
587 }
588
589 return load;
590 }
591
592 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
593 Node* new_val, const Type* value_type) const {
594 GraphKit* kit = access.kit();
595 if (access.is_oop()) {
596 new_val = shenandoah_storeval_barrier(kit, new_val);
597 shenandoah_write_barrier_pre(kit, false /* do_load */,
598 NULL, NULL, max_juint, NULL, NULL,
599 expected_val /* pre_val */, T_OBJECT);
600
601 MemNode::MemOrd mo = access.mem_node_mo();
602 Node* mem = access.memory();
603 Node* adr = access.addr().node();
604 const TypePtr* adr_type = access.addr().type();
605 Node* load_store = NULL;
606
607 #ifdef _LP64
608 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
609 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop()));
610 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop()));
611 if (ShenandoahCASBarrier) {
612 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo));
613 } else {
614 load_store = kit->gvn().transform(new CompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo));
615 }
616 } else
617 #endif
618 {
619 if (ShenandoahCASBarrier) {
620 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo));
621 } else {
622 load_store = kit->gvn().transform(new CompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo));
623 }
624 }
625
626 access.set_raw_access(load_store);
627 pin_atomic_op(access);
628
629 #ifdef _LP64
630 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
631 load_store = kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type()));
632 }
633 #endif
634 load_store = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(NULL, load_store, false));
635 return load_store;
636 }
637 return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);
638 }
639
640 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
641 Node* new_val, const Type* value_type) const {
642 GraphKit* kit = access.kit();
643 if (access.is_oop()) {
644 new_val = shenandoah_storeval_barrier(kit, new_val);
645 shenandoah_write_barrier_pre(kit, false /* do_load */,
646 NULL, NULL, max_juint, NULL, NULL,
647 expected_val /* pre_val */, T_OBJECT);
648 DecoratorSet decorators = access.decorators();
649 MemNode::MemOrd mo = access.mem_node_mo();
650 Node* mem = access.memory();
651 bool is_weak_cas = (decorators & C2_WEAK_CMPXCHG) != 0;
652 Node* load_store = NULL;
653 Node* adr = access.addr().node();
654 #ifdef _LP64
655 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
656 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop()));
657 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop()));
658 if (ShenandoahCASBarrier) {
659 if (is_weak_cas) {
660 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo));
661 } else {
662 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo));
663 }
664 } else {
665 if (is_weak_cas) {
666 load_store = kit->gvn().transform(new WeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo));
667 } else {
668 load_store = kit->gvn().transform(new CompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo));
669 }
670 }
671 } else
672 #endif
673 {
674 if (ShenandoahCASBarrier) {
675 if (is_weak_cas) {
676 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
677 } else {
678 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
679 }
680 } else {
681 if (is_weak_cas) {
682 load_store = kit->gvn().transform(new WeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
683 } else {
684 load_store = kit->gvn().transform(new CompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
685 }
686 }
687 }
688 access.set_raw_access(load_store);
689 pin_atomic_op(access);
690 return load_store;
691 }
692 return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
693 }
694
695 Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* val, const Type* value_type) const {
696 GraphKit* kit = access.kit();
697 if (access.is_oop()) {
698 val = shenandoah_storeval_barrier(kit, val);
699 }
700 Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type);
701 if (access.is_oop()) {
702 result = kit->gvn().transform(new ShenandoahLoadReferenceBarrierNode(NULL, result, false));
703 shenandoah_write_barrier_pre(kit, false /* do_load */,
704 NULL, NULL, max_juint, NULL, NULL,
705 result /* pre_val */, T_OBJECT);
706 }
707 return result;
708 }
709
710 // Support for GC barriers emitted during parsing
711 bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const {
712 if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) return true;
713 if (node->Opcode() != Op_CallLeaf && node->Opcode() != Op_CallLeafNoFP) {
714 return false;
715 }
716 CallLeafNode *call = node->as_CallLeaf();
717 if (call->_name == NULL) {
718 return false;
719 }
720
721 return strcmp(call->_name, "shenandoah_clone_barrier") == 0 ||
722 strcmp(call->_name, "shenandoah_cas_obj") == 0 ||
723 strcmp(call->_name, "shenandoah_wb_pre") == 0;
724 }
725
726 Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const {
727 if (c->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
728 return c->in(ShenandoahLoadReferenceBarrierNode::ValueIn);
729 }
730 if (c->Opcode() == Op_ShenandoahEnqueueBarrier) {
731 c = c->in(1);
732 }
733 return c;
734 }
735
736 bool ShenandoahBarrierSetC2::expand_barriers(Compile* C, PhaseIterGVN& igvn) const {
737 return !ShenandoahBarrierC2Support::expand(C, igvn);
738 }
739
740 bool ShenandoahBarrierSetC2::optimize_loops(PhaseIdealLoop* phase, LoopOptsMode mode, VectorSet& visited, Node_Stack& nstack, Node_List& worklist) const {
741 if (mode == LoopOptsShenandoahExpand) {
742 assert(UseShenandoahGC, "only for shenandoah");
743 ShenandoahBarrierC2Support::pin_and_expand(phase);
744 return true;
745 } else if (mode == LoopOptsShenandoahPostExpand) {
746 assert(UseShenandoahGC, "only for shenandoah");
747 visited.Clear();
748 ShenandoahBarrierC2Support::optimize_after_expansion(visited, nstack, worklist, phase);
749 return true;
750 }
751 return false;
752 }
753
754 bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const {
755 bool is_oop = type == T_OBJECT || type == T_ARRAY;
756 if (!is_oop) {
757 return false;
758 }
759 if (tightly_coupled_alloc) {
760 if (phase == Optimization) {
761 return false;
762 }
763 return !is_clone;
764 }
765 if (phase == Optimization) {
766 return !ShenandoahStoreValEnqueueBarrier;
767 }
768 return true;
769 }
770
771 bool ShenandoahBarrierSetC2::clone_needs_barrier(Node* src, PhaseGVN& gvn) {
772 const TypeOopPtr* src_type = gvn.type(src)->is_oopptr();
773 if (src_type->isa_instptr() != NULL) {
774 ciInstanceKlass* ik = src_type->klass()->as_instance_klass();
775 if ((src_type->klass_is_exact() || (!ik->is_interface() && !ik->has_subklass())) && !ik->has_injected_fields()) {
776 if (ik->has_object_fields()) {
777 return true;
778 } else {
779 if (!src_type->klass_is_exact()) {
780 Compile::current()->dependencies()->assert_leaf_type(ik);
781 }
782 }
783 } else {
784 return true;
785 }
786 } else if (src_type->isa_aryptr()) {
787 BasicType src_elem = src_type->klass()->as_array_klass()->element_type()->basic_type();
788 if (src_elem == T_OBJECT || src_elem == T_ARRAY) {
789 return true;
790 }
791 } else {
792 return true;
793 }
794 return false;
795 }
796
797 #define XTOP LP64_ONLY(COMMA phase->top())
798
799 void ShenandoahBarrierSetC2::clone_at_expansion(PhaseMacroExpand* phase, ArrayCopyNode* ac) const {
800 Node* ctrl = ac->in(TypeFunc::Control);
801 Node* mem = ac->in(TypeFunc::Memory);
802 Node* src = ac->in(ArrayCopyNode::Src);
803 Node* src_offset = ac->in(ArrayCopyNode::SrcPos);
804 Node* dest = ac->in(ArrayCopyNode::Dest);
805 Node* dest_offset = ac->in(ArrayCopyNode::DestPos);
806 Node* length = ac->in(ArrayCopyNode::Length);
807 assert (src_offset == NULL && dest_offset == NULL, "for clone offsets should be null");
808 if (ShenandoahCloneBarrier && clone_needs_barrier(src, phase->igvn())) {
809 const char* copyfunc_name = "shenandoah_clone";
810 address copyfunc_addr = CAST_FROM_FN_PTR(address, ShenandoahRuntime::shenandoah_clone_barrier);
811 const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
812 const TypeFunc* call_type = ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type();
813 Node* call = phase->make_leaf_call(ctrl, mem, call_type, copyfunc_addr, copyfunc_name, raw_adr_type, src, dest, length);
814 call = phase->transform_later(call);
815 phase->igvn().replace_node(ac, call);
816 } else {
817 BarrierSetC2::clone_at_expansion(phase, ac);
818 }
819 }
820
821
822 // Support for macro expanded GC barriers
823 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const {
824 if (node->Opcode() == Op_ShenandoahEnqueueBarrier) {
825 state()->add_enqueue_barrier((ShenandoahEnqueueBarrierNode*) node);
826 }
827 if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
828 state()->add_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node);
829 }
830 }
831
832 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const {
833 if (node->Opcode() == Op_ShenandoahEnqueueBarrier) {
834 state()->remove_enqueue_barrier((ShenandoahEnqueueBarrierNode*) node);
835 }
836 if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
837 state()->remove_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node);
838 }
839 }
840
841 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* n) const {
842 if (is_shenandoah_wb_pre_call(n)) {
843 shenandoah_eliminate_wb_pre(n, ¯o->igvn());
844 }
845 }
846
847 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const {
848 assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), "");
849 Node* c = call->as_Call()->proj_out(TypeFunc::Control);
850 c = c->unique_ctrl_out();
851 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
852 c = c->unique_ctrl_out();
853 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
854 Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
855 assert(iff->is_If(), "expect test");
856 if (!is_shenandoah_marking_if(igvn, iff)) {
857 c = c->unique_ctrl_out();
858 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
859 iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
860 assert(is_shenandoah_marking_if(igvn, iff), "expect marking test");
861 }
862 Node* cmpx = iff->in(1)->in(1);
863 igvn->replace_node(cmpx, igvn->makecon(TypeInt::CC_EQ));
864 igvn->rehash_node_delayed(call);
865 call->del_req(call->req()-1);
866 }
867
868 void ShenandoahBarrierSetC2::enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const {
869 if (node->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(node)) {
870 igvn->add_users_to_worklist(node);
871 }
872 }
873
874 void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const {
875 for (uint i = 0; i < useful.size(); i++) {
876 Node* n = useful.at(i);
877 if (n->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(n)) {
878 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
879 C->record_for_igvn(n->fast_out(i));
880 }
881 }
882 }
883 for (int i = state()->enqueue_barriers_count() - 1; i >= 0; i--) {
884 ShenandoahEnqueueBarrierNode* n = state()->enqueue_barrier(i);
885 if (!useful.member(n)) {
886 state()->remove_enqueue_barrier(n);
887 }
888 }
889 for (int i = state()->load_reference_barriers_count() - 1; i >= 0; i--) {
890 ShenandoahLoadReferenceBarrierNode* n = state()->load_reference_barrier(i);
891 if (!useful.member(n)) {
892 state()->remove_load_reference_barrier(n);
893 }
894 }
895 }
896
897 void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const {
898 return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena);
899 }
900
901 ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const {
902 return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state());
903 }
904
905 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be
906 // expanded later, then now is the time to do so.
907 bool ShenandoahBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { return false; }
908
909 #ifdef ASSERT
910 void ShenandoahBarrierSetC2::verify_gc_barriers(Compile* compile, CompilePhase phase) const {
911 if (ShenandoahVerifyOptoBarriers && phase == BarrierSetC2::BeforeMacroExpand) {
912 ShenandoahBarrierC2Support::verify(Compile::current()->root());
913 } else if (phase == BarrierSetC2::BeforeCodeGen) {
914 // Verify G1 pre-barriers
915 const int marking_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset());
916
917 ResourceArea *area = Thread::current()->resource_area();
918 Unique_Node_List visited(area);
919 Node_List worklist(area);
920 // We're going to walk control flow backwards starting from the Root
921 worklist.push(compile->root());
922 while (worklist.size() > 0) {
923 Node *x = worklist.pop();
924 if (x == NULL || x == compile->top()) continue;
925 if (visited.member(x)) {
926 continue;
927 } else {
928 visited.push(x);
929 }
930
931 if (x->is_Region()) {
932 for (uint i = 1; i < x->req(); i++) {
933 worklist.push(x->in(i));
934 }
935 } else {
936 worklist.push(x->in(0));
937 // We are looking for the pattern:
938 // /->ThreadLocal
939 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
940 // \->ConI(0)
941 // We want to verify that the If and the LoadB have the same control
942 // See GraphKit::g1_write_barrier_pre()
943 if (x->is_If()) {
944 IfNode *iff = x->as_If();
945 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
946 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
947 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
948 && cmp->in(1)->is_Load()) {
949 LoadNode *load = cmp->in(1)->as_Load();
950 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
951 && load->in(2)->in(3)->is_Con()
952 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
953
954 Node *if_ctrl = iff->in(0);
955 Node *load_ctrl = load->in(0);
956
957 if (if_ctrl != load_ctrl) {
958 // Skip possible CProj->NeverBranch in infinite loops
959 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
960 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
961 if_ctrl = if_ctrl->in(0)->in(0);
962 }
963 }
964 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
965 }
966 }
967 }
968 }
969 }
970 }
971 }
972 }
973 #endif
974
975 Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const {
976 if (is_shenandoah_wb_pre_call(n)) {
977 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt();
978 if (n->req() > cnt) {
979 Node* addp = n->in(cnt);
980 if (has_only_shenandoah_wb_pre_uses(addp)) {
981 n->del_req(cnt);
982 if (can_reshape) {
983 phase->is_IterGVN()->_worklist.push(addp);
984 }
985 return n;
986 }
987 }
988 }
989 if (n->Opcode() == Op_CmpP) {
990 Node* in1 = n->in(1);
991 Node* in2 = n->in(2);
992 if (in1->bottom_type() == TypePtr::NULL_PTR) {
993 in2 = step_over_gc_barrier(in2);
994 }
995 if (in2->bottom_type() == TypePtr::NULL_PTR) {
996 in1 = step_over_gc_barrier(in1);
997 }
998 PhaseIterGVN* igvn = phase->is_IterGVN();
999 if (in1 != n->in(1)) {
1000 if (igvn != NULL) {
1001 n->set_req_X(1, in1, igvn);
1002 } else {
1003 n->set_req(1, in1);
1004 }
1005 assert(in2 == n->in(2), "only one change");
1006 return n;
1007 }
1008 if (in2 != n->in(2)) {
1009 if (igvn != NULL) {
1010 n->set_req_X(2, in2, igvn);
1011 } else {
1012 n->set_req(2, in2);
1013 }
1014 return n;
1015 }
1016 } else if (can_reshape &&
1017 n->Opcode() == Op_If &&
1018 ShenandoahBarrierC2Support::is_heap_stable_test(n) &&
1019 n->in(0) != NULL) {
1020 Node* dom = n->in(0);
1021 Node* prev_dom = n;
1022 int op = n->Opcode();
1023 int dist = 16;
1024 // Search up the dominator tree for another heap stable test
1025 while (dom->Opcode() != op || // Not same opcode?
1026 !ShenandoahBarrierC2Support::is_heap_stable_test(dom) || // Not same input 1?
1027 prev_dom->in(0) != dom) { // One path of test does not dominate?
1028 if (dist < 0) return NULL;
1029
1030 dist--;
1031 prev_dom = dom;
1032 dom = IfNode::up_one_dom(dom);
1033 if (!dom) return NULL;
1034 }
1035
1036 // Check that we did not follow a loop back to ourselves
1037 if (n == dom) {
1038 return NULL;
1039 }
1040
1041 return n->as_If()->dominated_by(prev_dom, phase->is_IterGVN());
1042 }
1043
1044 return NULL;
1045 }
1046
1047 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) {
1048 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1049 Node* u = n->fast_out(i);
1050 if (!is_shenandoah_wb_pre_call(u)) {
1051 return false;
1052 }
1053 }
1054 return n->outcnt() > 0;
1055 }
1056
1057 bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode) const {
1058 switch (opcode) {
1059 case Op_CallLeaf:
1060 case Op_CallLeafNoFP: {
1061 assert (n->is_Call(), "");
1062 CallNode *call = n->as_Call();
1063 if (ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(call)) {
1064 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt();
1065 if (call->req() > cnt) {
1066 assert(call->req() == cnt + 1, "only one extra input");
1067 Node *addp = call->in(cnt);
1068 assert(!ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(addp), "useless address computation?");
1069 call->del_req(cnt);
1070 }
1071 }
1072 return false;
1073 }
1074 case Op_ShenandoahCompareAndSwapP:
1075 case Op_ShenandoahCompareAndSwapN:
1076 case Op_ShenandoahWeakCompareAndSwapN:
1077 case Op_ShenandoahWeakCompareAndSwapP:
1078 case Op_ShenandoahCompareAndExchangeP:
1079 case Op_ShenandoahCompareAndExchangeN:
1080 #ifdef ASSERT
1081 if( VerifyOptoOopOffsets ) {
1082 MemNode* mem = n->as_Mem();
1083 // Check to see if address types have grounded out somehow.
1084 const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
1085 ciInstanceKlass *k = tp->klass()->as_instance_klass();
1086 bool oop_offset_is_sane = k->contains_field_offset(tp->offset());
1087 assert( !tp || oop_offset_is_sane, "" );
1088 }
1089 #endif
1090 return true;
1091 case Op_ShenandoahLoadReferenceBarrier:
1092 assert(false, "should have been expanded already");
1093 return true;
1094 default:
1095 return false;
1096 }
1097 }
1098
1099 bool ShenandoahBarrierSetC2::escape_add_to_con_graph(ConnectionGraph* conn_graph, PhaseGVN* gvn, Unique_Node_List* delayed_worklist, Node* n, uint opcode) const {
1100 switch (opcode) {
1101 case Op_ShenandoahCompareAndExchangeP:
1102 case Op_ShenandoahCompareAndExchangeN:
1103 conn_graph->add_objload_to_connection_graph(n, delayed_worklist);
1104 // fallthrough
1105 case Op_ShenandoahWeakCompareAndSwapP:
1106 case Op_ShenandoahWeakCompareAndSwapN:
1107 case Op_ShenandoahCompareAndSwapP:
1108 case Op_ShenandoahCompareAndSwapN:
1109 conn_graph->add_to_congraph_unsafe_access(n, opcode, delayed_worklist);
1110 return true;
1111 case Op_StoreP: {
1112 Node* adr = n->in(MemNode::Address);
1113 const Type* adr_type = gvn->type(adr);
1114 // Pointer stores in G1 barriers looks like unsafe access.
1115 // Ignore such stores to be able scalar replace non-escaping
1116 // allocations.
1117 if (adr_type->isa_rawptr() && adr->is_AddP()) {
1118 Node* base = conn_graph->get_addp_base(adr);
1119 if (base->Opcode() == Op_LoadP &&
1120 base->in(MemNode::Address)->is_AddP()) {
1121 adr = base->in(MemNode::Address);
1122 Node* tls = conn_graph->get_addp_base(adr);
1123 if (tls->Opcode() == Op_ThreadLocal) {
1124 int offs = (int) gvn->find_intptr_t_con(adr->in(AddPNode::Offset), Type::OffsetBot);
1125 const int buf_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset());
1126 if (offs == buf_offset) {
1127 return true; // Pre barrier previous oop value store.
1128 }
1129 }
1130 }
1131 }
1132 return false;
1133 }
1134 case Op_ShenandoahEnqueueBarrier:
1135 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), delayed_worklist);
1136 break;
1137 case Op_ShenandoahLoadReferenceBarrier:
1138 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), delayed_worklist);
1139 return true;
1140 default:
1141 // Nothing
1142 break;
1143 }
1144 return false;
1145 }
1146
1147 bool ShenandoahBarrierSetC2::escape_add_final_edges(ConnectionGraph* conn_graph, PhaseGVN* gvn, Node* n, uint opcode) const {
1148 switch (opcode) {
1149 case Op_ShenandoahCompareAndExchangeP:
1150 case Op_ShenandoahCompareAndExchangeN: {
1151 Node *adr = n->in(MemNode::Address);
1152 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, adr, NULL);
1153 // fallthrough
1154 }
1155 case Op_ShenandoahCompareAndSwapP:
1156 case Op_ShenandoahCompareAndSwapN:
1157 case Op_ShenandoahWeakCompareAndSwapP:
1158 case Op_ShenandoahWeakCompareAndSwapN:
1159 return conn_graph->add_final_edges_unsafe_access(n, opcode);
1160 case Op_ShenandoahEnqueueBarrier:
1161 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(1), NULL);
1162 return true;
1163 case Op_ShenandoahLoadReferenceBarrier:
1164 conn_graph->add_local_var_and_edge(n, PointsToNode::NoEscape, n->in(ShenandoahLoadReferenceBarrierNode::ValueIn), NULL);
1165 return true;
1166 default:
1167 // Nothing
1168 break;
1169 }
1170 return false;
1171 }
1172
1173 bool ShenandoahBarrierSetC2::escape_has_out_with_unsafe_object(Node* n) const {
1174 return n->has_out_with(Op_ShenandoahCompareAndExchangeP) || n->has_out_with(Op_ShenandoahCompareAndExchangeN) ||
1175 n->has_out_with(Op_ShenandoahCompareAndSwapP, Op_ShenandoahCompareAndSwapN, Op_ShenandoahWeakCompareAndSwapP, Op_ShenandoahWeakCompareAndSwapN);
1176
1177 }
1178
1179 bool ShenandoahBarrierSetC2::matcher_find_shared_post_visit(Matcher* matcher, Node* n, uint opcode) const {
1180 switch (opcode) {
1181 case Op_ShenandoahCompareAndExchangeP:
1182 case Op_ShenandoahCompareAndExchangeN:
1183 case Op_ShenandoahWeakCompareAndSwapP:
1184 case Op_ShenandoahWeakCompareAndSwapN:
1185 case Op_ShenandoahCompareAndSwapP:
1186 case Op_ShenandoahCompareAndSwapN: { // Convert trinary to binary-tree
1187 Node* newval = n->in(MemNode::ValueIn);
1188 Node* oldval = n->in(LoadStoreConditionalNode::ExpectedIn);
1189 Node* pair = new BinaryNode(oldval, newval);
1190 n->set_req(MemNode::ValueIn,pair);
1191 n->del_req(LoadStoreConditionalNode::ExpectedIn);
1192 return true;
1193 }
1194 default:
1195 break;
1196 }
1197 return false;
1198 }
1199
1200 bool ShenandoahBarrierSetC2::matcher_is_store_load_barrier(Node* x, uint xop) const {
1201 return xop == Op_ShenandoahCompareAndExchangeP ||
1202 xop == Op_ShenandoahCompareAndExchangeN ||
1203 xop == Op_ShenandoahWeakCompareAndSwapP ||
1204 xop == Op_ShenandoahWeakCompareAndSwapN ||
1205 xop == Op_ShenandoahCompareAndSwapN ||
1206 xop == Op_ShenandoahCompareAndSwapP;
1207 }