1 /*
2 * Copyright (c) 2018, Red Hat, Inc. and/or its affiliates.
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/shenandoah/shenandoahHeap.hpp"
26 #include "gc/shenandoah/shenandoahHeuristics.hpp"
27 #include "gc/shenandoah/shenandoahRuntime.hpp"
28 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
29 #include "gc/shenandoah/c2/shenandoahSupport.hpp"
30 #include "opto/arraycopynode.hpp"
31 #include "opto/graphKit.hpp"
32 #include "opto/idealKit.hpp"
33 #include "opto/macro.hpp"
34 #include "opto/narrowptrnode.hpp"
35 #include "opto/rootnode.hpp"
36
37 ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() {
38 return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2());
39 }
40
41 ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena)
42 : _shenandoah_barriers(new (comp_arena) GrowableArray<ShenandoahWriteBarrierNode*>(comp_arena, 8, 0, NULL)) {
43 }
44
45 int ShenandoahBarrierSetC2State::shenandoah_barriers_count() const {
46 return _shenandoah_barriers->length();
47 }
48
49 ShenandoahWriteBarrierNode* ShenandoahBarrierSetC2State::shenandoah_barrier(int idx) const {
50 return _shenandoah_barriers->at(idx);
51 }
52
53 void ShenandoahBarrierSetC2State::add_shenandoah_barrier(ShenandoahWriteBarrierNode * n) {
54 assert(!_shenandoah_barriers->contains(n), "duplicate entry in barrier list");
55 _shenandoah_barriers->append(n);
56 }
57
58 void ShenandoahBarrierSetC2State::remove_shenandoah_barrier(ShenandoahWriteBarrierNode * n) {
59 if (_shenandoah_barriers->contains(n)) {
60 _shenandoah_barriers->remove(n);
61 }
62 }
63
64 #define __ kit->
65
66 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier(GraphKit* kit, Node* obj) const {
67 if (ShenandoahReadBarrier) {
68 obj = shenandoah_read_barrier_impl(kit, obj, false, true, true);
69 }
70 return obj;
71 }
72
73 Node* ShenandoahBarrierSetC2::shenandoah_storeval_barrier(GraphKit* kit, Node* obj) const {
74 if (ShenandoahStoreValEnqueueBarrier) {
75 obj = shenandoah_write_barrier(kit, obj);
76 obj = shenandoah_enqueue_barrier(kit, obj);
77 }
78 if (ShenandoahStoreValReadBarrier) {
79 obj = shenandoah_read_barrier_impl(kit, obj, true, false, false);
80 }
81 return obj;
82 }
83
84 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier_acmp(GraphKit* kit, Node* obj) {
85 return shenandoah_read_barrier_impl(kit, obj, true, true, false);
86 }
87
88 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier_impl(GraphKit* kit, Node* obj, bool use_ctrl, bool use_mem, bool allow_fromspace) const {
89 const Type* obj_type = obj->bottom_type();
90 if (obj_type->higher_equal(TypePtr::NULL_PTR)) {
91 return obj;
92 }
93 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type);
94 Node* mem = use_mem ? __ memory(adr_type) : __ immutable_memory();
95
96 if (! ShenandoahBarrierNode::needs_barrier(&__ gvn(), NULL, obj, mem, allow_fromspace)) {
97 // We know it is null, no barrier needed.
98 return obj;
99 }
100
101 if (obj_type->meet(TypePtr::NULL_PTR) == obj_type->remove_speculative()) {
102
103 // We don't know if it's null or not. Need null-check.
104 enum { _not_null_path = 1, _null_path, PATH_LIMIT };
105 RegionNode* region = new RegionNode(PATH_LIMIT);
106 Node* phi = new PhiNode(region, obj_type);
107 Node* null_ctrl = __ top();
108 Node* not_null_obj = __ null_check_oop(obj, &null_ctrl);
109
110 region->init_req(_null_path, null_ctrl);
111 phi ->init_req(_null_path, __ zerocon(T_OBJECT));
112
113 Node* ctrl = use_ctrl ? __ control() : NULL;
114 ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, not_null_obj, allow_fromspace);
115 Node* n = __ gvn().transform(rb);
116
117 region->init_req(_not_null_path, __ control());
118 phi ->init_req(_not_null_path, n);
119
120 __ set_control(__ gvn().transform(region));
121 __ record_for_igvn(region);
122 return __ gvn().transform(phi);
123
124 } else {
125 // We know it is not null. Simple barrier is sufficient.
126 Node* ctrl = use_ctrl ? __ control() : NULL;
127 ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, obj, allow_fromspace);
128 Node* n = __ gvn().transform(rb);
129 __ record_for_igvn(n);
130 return n;
131 }
132 }
133
134 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier_helper(GraphKit* kit, Node* obj, const TypePtr* adr_type) const {
135 ShenandoahWriteBarrierNode* wb = new ShenandoahWriteBarrierNode(kit->C, kit->control(), kit->memory(adr_type), obj);
136 Node* n = __ gvn().transform(wb);
137 if (n == wb) { // New barrier needs memory projection.
138 Node* proj = __ gvn().transform(new ShenandoahWBMemProjNode(n));
139 __ set_memory(proj, adr_type);
140 }
141 return n;
142 }
143
144 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier(GraphKit* kit, Node* obj) const {
145 if (ShenandoahWriteBarrier) {
146 obj = shenandoah_write_barrier_impl(kit, obj);
147 }
148 return obj;
149 }
150
151 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier_impl(GraphKit* kit, Node* obj) const {
152 if (! ShenandoahBarrierNode::needs_barrier(&__ gvn(), NULL, obj, NULL, true)) {
153 return obj;
154 }
155 const Type* obj_type = obj->bottom_type();
156 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type);
157 Node* n = shenandoah_write_barrier_helper(kit, obj, adr_type);
158 __ record_for_igvn(n);
159 return n;
160 }
161
162 bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr,
163 BasicType bt, uint adr_idx) const {
164 intptr_t offset = 0;
165 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
166 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
167
168 if (offset == Type::OffsetBot) {
169 return false; // cannot unalias unless there are precise offsets
170 }
171
172 if (alloc == NULL) {
173 return false; // No allocation found
174 }
175
176 intptr_t size_in_bytes = type2aelembytes(bt);
177
178 Node* mem = __ memory(adr_idx); // start searching here...
179
180 for (int cnt = 0; cnt < 50; cnt++) {
181
182 if (mem->is_Store()) {
183
184 Node* st_adr = mem->in(MemNode::Address);
185 intptr_t st_offset = 0;
186 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
187
188 if (st_base == NULL) {
189 break; // inscrutable pointer
190 }
191
192 // Break we have found a store with same base and offset as ours so break
193 if (st_base == base && st_offset == offset) {
194 break;
195 }
196
197 if (st_offset != offset && st_offset != Type::OffsetBot) {
198 const int MAX_STORE = BytesPerLong;
199 if (st_offset >= offset + size_in_bytes ||
200 st_offset <= offset - MAX_STORE ||
201 st_offset <= offset - mem->as_Store()->memory_size()) {
202 // Success: The offsets are provably independent.
203 // (You may ask, why not just test st_offset != offset and be done?
204 // The answer is that stores of different sizes can co-exist
205 // in the same sequence of RawMem effects. We sometimes initialize
206 // a whole 'tile' of array elements with a single jint or jlong.)
207 mem = mem->in(MemNode::Memory);
208 continue; // advance through independent store memory
209 }
210 }
211
212 if (st_base != base
213 && MemNode::detect_ptr_independence(base, alloc, st_base,
214 AllocateNode::Ideal_allocation(st_base, phase),
215 phase)) {
216 // Success: The bases are provably independent.
217 mem = mem->in(MemNode::Memory);
218 continue; // advance through independent store memory
219 }
220 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
221
222 InitializeNode* st_init = mem->in(0)->as_Initialize();
223 AllocateNode* st_alloc = st_init->allocation();
224
225 // Make sure that we are looking at the same allocation site.
226 // The alloc variable is guaranteed to not be null here from earlier check.
227 if (alloc == st_alloc) {
228 // Check that the initialization is storing NULL so that no previous store
229 // has been moved up and directly write a reference
230 Node* captured_store = st_init->find_captured_store(offset,
231 type2aelembytes(T_OBJECT),
232 phase);
233 if (captured_store == NULL || captured_store == st_init->zero_memory()) {
234 return true;
235 }
236 }
237 }
238
239 // Unless there is an explicit 'continue', we must bail out here,
240 // because 'mem' is an inscrutable memory state (e.g., a call).
241 break;
242 }
243
244 return false;
245 }
246
247 #undef __
248 #define __ ideal.
249
250 void ShenandoahBarrierSetC2::satb_write_barrier_pre(GraphKit* kit,
251 bool do_load,
252 Node* obj,
253 Node* adr,
254 uint alias_idx,
255 Node* val,
256 const TypeOopPtr* val_type,
257 Node* pre_val,
258 BasicType bt) const {
259 // Some sanity checks
260 // Note: val is unused in this routine.
261
262 if (do_load) {
263 // We need to generate the load of the previous value
264 assert(obj != NULL, "must have a base");
265 assert(adr != NULL, "where are loading from?");
266 assert(pre_val == NULL, "loaded already?");
267 assert(val_type != NULL, "need a type");
268
269 if (ReduceInitialCardMarks
270 && satb_can_remove_pre_barrier(kit, &kit->gvn(), adr, bt, alias_idx)) {
271 return;
272 }
273
274 } else {
275 // In this case both val_type and alias_idx are unused.
276 assert(pre_val != NULL, "must be loaded already");
277 // Nothing to be done if pre_val is null.
278 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
279 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
280 }
281 assert(bt == T_OBJECT, "or we shouldn't be here");
282
283 IdealKit ideal(kit, true);
284
285 Node* tls = __ thread(); // ThreadLocalStorage
286
287 Node* no_base = __ top();
288 Node* zero = __ ConI(0);
289 Node* zeroX = __ ConX(0);
290
291 float likely = PROB_LIKELY(0.999);
292 float unlikely = PROB_UNLIKELY(0.999);
293
294 // Offsets into the thread
295 const int index_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset());
296 const int buffer_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset());
297
298 // Now the actual pointers into the thread
299 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
300 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
301
302 // Now some of the values
303 Node* marking;
304 Node* gc_state = __ AddP(no_base, tls, __ ConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset())));
305 Node* ld = __ load(__ ctrl(), gc_state, TypeInt::BYTE, T_BYTE, Compile::AliasIdxRaw);
306 marking = __ AndI(ld, __ ConI(ShenandoahHeap::MARKING));
307 assert(ShenandoahWriteBarrierNode::is_gc_state_load(ld), "Should match the shape");
308
309 // if (!marking)
310 __ if_then(marking, BoolTest::ne, zero, unlikely); {
311 BasicType index_bt = TypeX_X->basic_type();
312 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
313 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
314
315 if (do_load) {
316 // load original value
317 // alias_idx correct??
318 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
319 }
320
321 // if (pre_val != NULL)
322 __ if_then(pre_val, BoolTest::ne, kit->null()); {
323 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
324
325 // is the queue for this thread full?
326 __ if_then(index, BoolTest::ne, zeroX, likely); {
327
328 // decrement the index
329 Node* next_index = kit->gvn().transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
330
331 // Now get the buffer location we will log the previous value into and store it
332 Node *log_addr = __ AddP(no_base, buffer, next_index);
333 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
334 // update the index
335 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
336
337 } __ else_(); {
338
339 // logging buffer is full, call the runtime
340 const TypeFunc *tf = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type();
341 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), "shenandoah_wb_pre", pre_val, tls);
342 } __ end_if(); // (!index)
343 } __ end_if(); // (pre_val != NULL)
344 } __ end_if(); // (!marking)
345
346 // Final sync IdealKit and GraphKit.
347 kit->final_sync(ideal);
348
349 if (ShenandoahSATBBarrier && adr != NULL) {
350 Node* c = kit->control();
351 Node* call = c->in(1)->in(1)->in(1)->in(0);
352 assert(is_shenandoah_wb_pre_call(call), "shenandoah_wb_pre call expected");
353 call->add_req(adr);
354 }
355 }
356
357 bool ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(Node* call) {
358 return call->is_CallLeaf() &&
359 call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry);
360 }
361
362 bool ShenandoahBarrierSetC2::is_shenandoah_wb_call(Node* call) {
363 return call->is_CallLeaf() &&
364 call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_barrier_JRT);
365 }
366
367 bool ShenandoahBarrierSetC2::is_shenandoah_marking_if(PhaseTransform *phase, Node* n) {
368 if (n->Opcode() != Op_If) {
369 return false;
370 }
371
372 Node* bol = n->in(1);
373 assert(bol->is_Bool(), "");
374 Node* cmpx = bol->in(1);
375 if (bol->as_Bool()->_test._test == BoolTest::ne &&
376 cmpx->is_Cmp() && cmpx->in(2) == phase->intcon(0) &&
377 is_shenandoah_state_load(cmpx->in(1)->in(1)) &&
378 cmpx->in(1)->in(2)->is_Con() &&
379 cmpx->in(1)->in(2) == phase->intcon(ShenandoahHeap::MARKING)) {
380 return true;
381 }
382
383 return false;
384 }
385
386 bool ShenandoahBarrierSetC2::is_shenandoah_state_load(Node* n) {
387 if (!n->is_Load()) return false;
388 const int state_offset = in_bytes(ShenandoahThreadLocalData::gc_state_offset());
389 return n->in(2)->is_AddP() && n->in(2)->in(2)->Opcode() == Op_ThreadLocal
390 && n->in(2)->in(3)->is_Con()
391 && n->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == state_offset;
392 }
393
394 void ShenandoahBarrierSetC2::shenandoah_write_barrier_pre(GraphKit* kit,
395 bool do_load,
396 Node* obj,
397 Node* adr,
398 uint alias_idx,
399 Node* val,
400 const TypeOopPtr* val_type,
401 Node* pre_val,
402 BasicType bt) const {
403 if (ShenandoahSATBBarrier) {
404 IdealKit ideal(kit);
405 kit->sync_kit(ideal);
406
407 satb_write_barrier_pre(kit, do_load, obj, adr, alias_idx, val, val_type, pre_val, bt);
408
409 ideal.sync_kit(kit);
410 kit->final_sync(ideal);
411 }
412 }
413
414 Node* ShenandoahBarrierSetC2::shenandoah_enqueue_barrier(GraphKit* kit, Node* pre_val) const {
415 return kit->gvn().transform(new ShenandoahEnqueueBarrierNode(pre_val));
416 }
417
418 // Helper that guards and inserts a pre-barrier.
419 void ShenandoahBarrierSetC2::insert_pre_barrier(GraphKit* kit, Node* base_oop, Node* offset,
420 Node* pre_val, bool need_mem_bar) const {
421 // We could be accessing the referent field of a reference object. If so, when G1
422 // is enabled, we need to log the value in the referent field in an SATB buffer.
423 // This routine performs some compile time filters and generates suitable
424 // runtime filters that guard the pre-barrier code.
425 // Also add memory barrier for non volatile load from the referent field
426 // to prevent commoning of loads across safepoint.
427
428 // Some compile time checks.
429
430 // If offset is a constant, is it java_lang_ref_Reference::_reference_offset?
431 const TypeX* otype = offset->find_intptr_t_type();
432 if (otype != NULL && otype->is_con() &&
433 otype->get_con() != java_lang_ref_Reference::referent_offset) {
434 // Constant offset but not the reference_offset so just return
435 return;
436 }
437
438 // We only need to generate the runtime guards for instances.
439 const TypeOopPtr* btype = base_oop->bottom_type()->isa_oopptr();
440 if (btype != NULL) {
441 if (btype->isa_aryptr()) {
442 // Array type so nothing to do
443 return;
444 }
445
446 const TypeInstPtr* itype = btype->isa_instptr();
447 if (itype != NULL) {
448 // Can the klass of base_oop be statically determined to be
449 // _not_ a sub-class of Reference and _not_ Object?
450 ciKlass* klass = itype->klass();
451 if ( klass->is_loaded() &&
452 !klass->is_subtype_of(kit->env()->Reference_klass()) &&
453 !kit->env()->Object_klass()->is_subtype_of(klass)) {
454 return;
455 }
456 }
457 }
458
459 // The compile time filters did not reject base_oop/offset so
460 // we need to generate the following runtime filters
461 //
462 // if (offset == java_lang_ref_Reference::_reference_offset) {
463 // if (instance_of(base, java.lang.ref.Reference)) {
464 // pre_barrier(_, pre_val, ...);
465 // }
466 // }
467
468 float likely = PROB_LIKELY( 0.999);
469 float unlikely = PROB_UNLIKELY(0.999);
470
471 IdealKit ideal(kit);
472
473 Node* referent_off = __ ConX(java_lang_ref_Reference::referent_offset);
474
475 __ if_then(offset, BoolTest::eq, referent_off, unlikely); {
476 // Update graphKit memory and control from IdealKit.
477 kit->sync_kit(ideal);
478
479 Node* ref_klass_con = kit->makecon(TypeKlassPtr::make(kit->env()->Reference_klass()));
480 Node* is_instof = kit->gen_instanceof(base_oop, ref_klass_con);
481
482 // Update IdealKit memory and control from graphKit.
483 __ sync_kit(kit);
484
485 Node* one = __ ConI(1);
486 // is_instof == 0 if base_oop == NULL
487 __ if_then(is_instof, BoolTest::eq, one, unlikely); {
488
489 // Update graphKit from IdeakKit.
490 kit->sync_kit(ideal);
491
492 // Use the pre-barrier to record the value in the referent field
493 satb_write_barrier_pre(kit, false /* do_load */,
494 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */,
495 pre_val /* pre_val */,
496 T_OBJECT);
497 if (need_mem_bar) {
498 // Add memory barrier to prevent commoning reads from this field
499 // across safepoint since GC can change its value.
500 kit->insert_mem_bar(Op_MemBarCPUOrder);
501 }
502 // Update IdealKit from graphKit.
503 __ sync_kit(kit);
504
505 } __ end_if(); // _ref_type != ref_none
506 } __ end_if(); // offset == referent_offset
507
508 // Final sync IdealKit and GraphKit.
509 kit->final_sync(ideal);
510 }
511
512 #undef __
513
514 const TypeFunc* ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type() {
515 const Type **fields = TypeTuple::fields(2);
516 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
517 fields[TypeFunc::Parms+1] = TypeRawPtr::NOTNULL; // thread
518 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields);
519
520 // create result type (range)
521 fields = TypeTuple::fields(0);
522 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields);
523
524 return TypeFunc::make(domain, range);
525 }
526
527 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type() {
528 const Type **fields = TypeTuple::fields(1);
529 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
530 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields);
531
532 // create result type (range)
533 fields = TypeTuple::fields(0);
534 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields);
535
536 return TypeFunc::make(domain, range);
537 }
538
539 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_write_barrier_Type() {
540 const Type **fields = TypeTuple::fields(1);
541 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
542 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields);
543
544 // create result type (range)
545 fields = TypeTuple::fields(1);
546 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL;
547 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields);
548
549 return TypeFunc::make(domain, range);
550 }
551
552 void ShenandoahBarrierSetC2::resolve_address(C2Access& access) const {
553 const TypePtr* adr_type = access.addr().type();
554
555 if ((access.decorators() & IN_NATIVE) == 0 && (adr_type->isa_instptr() || adr_type->isa_aryptr())) {
556 int off = adr_type->is_ptr()->offset();
557 int base_off = adr_type->isa_instptr() ? instanceOopDesc::base_offset_in_bytes() :
558 arrayOopDesc::base_offset_in_bytes(adr_type->is_aryptr()->elem()->array_element_basic_type());
559 assert(off != Type::OffsetTop, "unexpected offset");
560 if (off == Type::OffsetBot || off >= base_off) {
561 DecoratorSet decorators = access.decorators();
562 bool is_write = (decorators & C2_WRITE_ACCESS) != 0;
563 GraphKit* kit = NULL;
564 if (access.is_parse_access()) {
565 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
566 kit = parse_access.kit();
567 }
568 Node* adr = access.addr().node();
569 assert(adr->is_AddP(), "unexpected address shape");
570 Node* base = adr->in(AddPNode::Base);
571
572 if (is_write) {
573 if (kit != NULL) {
574 base = shenandoah_write_barrier(kit, base);
575 } else {
576 assert(access.is_opt_access(), "either parse or opt access");
577 assert((access.decorators() & C2_ARRAY_COPY) != 0, "can be skipped for clone");
578 }
579 } else {
580 if (adr_type->isa_instptr()) {
581 Compile* C = access.gvn().C;
582 ciField* field = C->alias_type(adr_type)->field();
583
584 // Insert read barrier for Shenandoah.
585 if (field != NULL &&
586 ((ShenandoahOptimizeStaticFinals && field->is_static() && field->is_final()) ||
587 (ShenandoahOptimizeInstanceFinals && !field->is_static() && field->is_final()) ||
588 (ShenandoahOptimizeStableFinals && field->is_stable()))) {
589 // Skip the barrier for special fields
590 } else {
591 if (kit != NULL) {
592 base = shenandoah_read_barrier(kit, base);
593 } else {
594 assert(access.is_opt_access(), "either parse or opt access");
595 assert((access.decorators() & C2_ARRAY_COPY) != 0, "can be skipped for arraycopy");
596 }
597 }
598 } else {
599 if (kit != NULL) {
600 base = shenandoah_read_barrier(kit, base);
601 } else {
602 assert(access.is_opt_access(), "either parse or opt access");
603 assert((access.decorators() & C2_ARRAY_COPY) != 0, "can be skipped for arraycopy");
604 }
605 }
606 }
607 if (base != adr->in(AddPNode::Base)) {
608 assert(kit != NULL, "no barrier should have been added");
609
610 Node* address = adr->in(AddPNode::Address);
611
612 if (address->is_AddP()) {
613 assert(address->in(AddPNode::Base) == adr->in(AddPNode::Base), "unexpected address shape");
614 assert(!address->in(AddPNode::Address)->is_AddP(), "unexpected address shape");
615 assert(address->in(AddPNode::Address) == adr->in(AddPNode::Base), "unexpected address shape");
616 address = address->clone();
617 address->set_req(AddPNode::Base, base);
618 address->set_req(AddPNode::Address, base);
619 address = kit->gvn().transform(address);
620 } else {
621 assert(address == adr->in(AddPNode::Base), "unexpected address shape");
622 address = base;
623 }
624 adr = adr->clone();
625 adr->set_req(AddPNode::Base, base);
626 adr->set_req(AddPNode::Address, address);
627 adr = kit->gvn().transform(adr);
628 access.addr().set_node(adr);
629 }
630 }
631 }
632 }
633
634 Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const {
635 DecoratorSet decorators = access.decorators();
636
637 const TypePtr* adr_type = access.addr().type();
638 Node* adr = access.addr().node();
639
640 bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
641 bool on_heap = (decorators & IN_HEAP) != 0;
642
643 if (!access.is_oop() || (!on_heap && !anonymous)) {
644 return BarrierSetC2::store_at_resolved(access, val);
645 }
646
647 if (access.is_parse_access()) {
648 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
649 GraphKit* kit = parse_access.kit();
650
651 uint adr_idx = kit->C->get_alias_index(adr_type);
652 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
653 Node* value = val.node();
654 value = shenandoah_storeval_barrier(kit, value);
655 val.set_node(value);
656 shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(),
657 static_cast<const TypeOopPtr*>(val.type()), NULL /* pre_val */, access.type());
658 } else {
659 assert(access.is_opt_access(), "only for optimization passes");
660 assert(((decorators & C2_TIGHLY_COUPLED_ALLOC) != 0 || !ShenandoahSATBBarrier) && (decorators & C2_ARRAY_COPY) != 0, "unexpected caller of this code");
661 C2OptAccess& opt_access = static_cast<C2OptAccess&>(access);
662 PhaseGVN& gvn = opt_access.gvn();
663 MergeMemNode* mm = opt_access.mem();
664
665 if (ShenandoahStoreValReadBarrier) {
666 RegionNode* region = new RegionNode(3);
667 const Type* v_t = gvn.type(val.node());
668 Node* phi = new PhiNode(region, v_t->isa_oopptr() ? v_t->is_oopptr()->cast_to_nonconst() : v_t);
669 Node* cmp = gvn.transform(new CmpPNode(val.node(), gvn.zerocon(T_OBJECT)));
670 Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::ne));
671 IfNode* iff = new IfNode(opt_access.ctl(), bol, PROB_LIKELY_MAG(3), COUNT_UNKNOWN);
672
673 gvn.transform(iff);
674 if (gvn.is_IterGVN()) {
675 gvn.is_IterGVN()->_worklist.push(iff);
676 } else {
677 gvn.record_for_igvn(iff);
678 }
679
680 Node* null_true = gvn.transform(new IfFalseNode(iff));
681 Node* null_false = gvn.transform(new IfTrueNode(iff));
682 region->init_req(1, null_true);
683 region->init_req(2, null_false);
684 phi->init_req(1, gvn.zerocon(T_OBJECT));
685 Node* cast = new CastPPNode(val.node(), gvn.type(val.node())->join_speculative(TypePtr::NOTNULL));
686 cast->set_req(0, null_false);
687 cast = gvn.transform(cast);
688 Node* rb = gvn.transform(new ShenandoahReadBarrierNode(null_false, gvn.C->immutable_memory(), cast, false));
689 phi->init_req(2, rb);
690 opt_access.set_ctl(gvn.transform(region));
691 val.set_node(gvn.transform(phi));
692 }
693 if (ShenandoahStoreValEnqueueBarrier) {
694 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(gvn.type(val.node()));
695 int alias = gvn.C->get_alias_index(adr_type);
696 Node* wb = new ShenandoahWriteBarrierNode(gvn.C, opt_access.ctl(), mm->memory_at(alias), val.node());
697 Node* wb_transformed = gvn.transform(wb);
698 Node* enqueue = gvn.transform(new ShenandoahEnqueueBarrierNode(wb_transformed));
699 if (wb_transformed == wb) {
700 Node* proj = gvn.transform(new ShenandoahWBMemProjNode(wb));
701 mm->set_memory_at(alias, proj);
702 }
703 val.set_node(enqueue);
704 }
705 }
706 return BarrierSetC2::store_at_resolved(access, val);
707 }
708
709 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
710 DecoratorSet decorators = access.decorators();
711
712 Node* adr = access.addr().node();
713 Node* obj = access.base();
714
715 bool mismatched = (decorators & C2_MISMATCHED) != 0;
716 bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0;
717 bool on_heap = (decorators & IN_HEAP) != 0;
718 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
719 bool is_unordered = (decorators & MO_UNORDERED) != 0;
720 bool need_cpu_mem_bar = !is_unordered || mismatched || !on_heap;
721
722 Node* top = Compile::current()->top();
723
724 Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : top;
725 Node* load = BarrierSetC2::load_at_resolved(access, val_type);
726
727 // If we are reading the value of the referent field of a Reference
728 // object (either by using Unsafe directly or through reflection)
729 // then, if SATB is enabled, we need to record the referent in an
730 // SATB log buffer using the pre-barrier mechanism.
731 // Also we need to add memory barrier to prevent commoning reads
732 // from this field across safepoint since GC can change its value.
733 bool need_read_barrier = ShenandoahKeepAliveBarrier &&
734 (on_heap && (on_weak || (unknown && offset != top && obj != top)));
735
736 if (!access.is_oop() || !need_read_barrier) {
737 return load;
738 }
739
740 assert(access.is_parse_access(), "entry not supported at optimization time");
741 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
742 GraphKit* kit = parse_access.kit();
743
744 if (on_weak) {
745 // Use the pre-barrier to record the value in the referent field
746 satb_write_barrier_pre(kit, false /* do_load */,
747 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */,
748 load /* pre_val */, T_OBJECT);
749 // Add memory barrier to prevent commoning reads from this field
750 // across safepoint since GC can change its value.
751 kit->insert_mem_bar(Op_MemBarCPUOrder);
752 } else if (unknown) {
753 // We do not require a mem bar inside pre_barrier if need_mem_bar
754 // is set: the barriers would be emitted by us.
755 insert_pre_barrier(kit, obj, offset, load, !need_cpu_mem_bar);
756 }
757
758 return load;
759 }
760
761 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
762 Node* new_val, const Type* value_type) const {
763 GraphKit* kit = access.kit();
764 if (access.is_oop()) {
765 new_val = shenandoah_storeval_barrier(kit, new_val);
766 shenandoah_write_barrier_pre(kit, false /* do_load */,
767 NULL, NULL, max_juint, NULL, NULL,
768 expected_val /* pre_val */, T_OBJECT);
769
770 MemNode::MemOrd mo = access.mem_node_mo();
771 Node* mem = access.memory();
772 Node* adr = access.addr().node();
773 const TypePtr* adr_type = access.addr().type();
774 Node* load_store = NULL;
775
776 #ifdef _LP64
777 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
778 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop()));
779 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop()));
780 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo));
781 } else
782 #endif
783 {
784 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo));
785 }
786
787 access.set_raw_access(load_store);
788 pin_atomic_op(access);
789
790 #ifdef _LP64
791 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
792 return kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type()));
793 }
794 #endif
795 return load_store;
796 }
797 return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);
798 }
799
800 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
801 Node* new_val, const Type* value_type) const {
802 GraphKit* kit = access.kit();
803 if (access.is_oop()) {
804 new_val = shenandoah_storeval_barrier(kit, new_val);
805 shenandoah_write_barrier_pre(kit, false /* do_load */,
806 NULL, NULL, max_juint, NULL, NULL,
807 expected_val /* pre_val */, T_OBJECT);
808 DecoratorSet decorators = access.decorators();
809 MemNode::MemOrd mo = access.mem_node_mo();
810 Node* mem = access.memory();
811 bool is_weak_cas = (decorators & C2_WEAK_CMPXCHG) != 0;
812 Node* load_store = NULL;
813 Node* adr = access.addr().node();
814 #ifdef _LP64
815 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
816 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop()));
817 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop()));
818 if (is_weak_cas) {
819 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo));
820 } else {
821 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo));
822 }
823 } else
824 #endif
825 {
826 if (is_weak_cas) {
827 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
828 } else {
829 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
830 }
831 }
832 access.set_raw_access(load_store);
833 pin_atomic_op(access);
834 return load_store;
835 }
836 return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
837 }
838
839 Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* val, const Type* value_type) const {
840 GraphKit* kit = access.kit();
841 if (access.is_oop()) {
842 val = shenandoah_storeval_barrier(kit, val);
843 }
844 Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type);
845 if (access.is_oop()) {
846 shenandoah_write_barrier_pre(kit, false /* do_load */,
847 NULL, NULL, max_juint, NULL, NULL,
848 result /* pre_val */, T_OBJECT);
849 }
850 return result;
851 }
852
853 void ShenandoahBarrierSetC2::clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const {
854 assert(!src->is_AddP(), "unexpected input");
855 src = shenandoah_read_barrier(kit, src);
856 BarrierSetC2::clone(kit, src, dst, size, is_array);
857 }
858
859 Node* ShenandoahBarrierSetC2::resolve(GraphKit* kit, Node* n, DecoratorSet decorators) const {
860 bool is_write = decorators & ACCESS_WRITE;
861 if (is_write) {
862 return shenandoah_write_barrier(kit, n);
863 } else {
864 return shenandoah_read_barrier(kit, n);
865 }
866 }
867
868 Node* ShenandoahBarrierSetC2::obj_allocate(PhaseMacroExpand* macro, Node* ctrl, Node* mem, Node* toobig_false, Node* size_in_bytes,
869 Node*& i_o, Node*& needgc_ctrl,
870 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem,
871 intx prefetch_lines) const {
872 PhaseIterGVN& igvn = macro->igvn();
873
874 // Allocate several words more for the Shenandoah brooks pointer.
875 size_in_bytes = new AddXNode(size_in_bytes, igvn.MakeConX(ShenandoahBrooksPointer::byte_size()));
876 macro->transform_later(size_in_bytes);
877
878 Node* fast_oop = BarrierSetC2::obj_allocate(macro, ctrl, mem, toobig_false, size_in_bytes,
879 i_o, needgc_ctrl, fast_oop_ctrl, fast_oop_rawmem,
880 prefetch_lines);
881
882 // Bump up object for Shenandoah brooks pointer.
883 fast_oop = new AddPNode(macro->top(), fast_oop, igvn.MakeConX(ShenandoahBrooksPointer::byte_size()));
884 macro->transform_later(fast_oop);
885
886 // Initialize Shenandoah brooks pointer to point to the object itself.
887 fast_oop_rawmem = macro->make_store(fast_oop_ctrl, fast_oop_rawmem, fast_oop, ShenandoahBrooksPointer::byte_offset(), fast_oop, T_OBJECT);
888
889 return fast_oop;
890 }
891
892 // Support for GC barriers emitted during parsing
893 bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const {
894 if (node->Opcode() != Op_CallLeaf && node->Opcode() != Op_CallLeafNoFP) {
895 return false;
896 }
897 CallLeafNode *call = node->as_CallLeaf();
898 if (call->_name == NULL) {
899 return false;
900 }
901
902 return strcmp(call->_name, "shenandoah_clone_barrier") == 0 ||
903 strcmp(call->_name, "shenandoah_cas_obj") == 0 ||
904 strcmp(call->_name, "shenandoah_wb_pre") == 0;
905 }
906
907 Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const {
908 return ShenandoahBarrierNode::skip_through_barrier(c);
909 }
910
911 bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const {
912 bool is_oop = type == T_OBJECT || type == T_ARRAY;
913 if (!is_oop) {
914 return false;
915 }
916
917 if (tightly_coupled_alloc) {
918 if (phase == Optimization) {
919 return false;
920 }
921 return !is_clone;
922 }
923 if (phase == Optimization) {
924 return !ShenandoahStoreValEnqueueBarrier;
925 }
926 return true;
927 }
928
929 bool ShenandoahBarrierSetC2::clone_needs_postbarrier(ArrayCopyNode *ac, PhaseIterGVN& igvn) {
930 Node* src = ac->in(ArrayCopyNode::Src);
931 const TypeOopPtr* src_type = igvn.type(src)->is_oopptr();
932 if (src_type->isa_instptr() != NULL) {
933 ciInstanceKlass* ik = src_type->klass()->as_instance_klass();
934 if ((src_type->klass_is_exact() || (!ik->is_interface() && !ik->has_subklass())) && !ik->has_injected_fields()) {
935 if (ik->has_object_fields()) {
936 return true;
937 } else {
938 if (!src_type->klass_is_exact()) {
939 igvn.C->dependencies()->assert_leaf_type(ik);
940 }
941 }
942 } else {
943 return true;
944 }
945 } else if (src_type->isa_aryptr()) {
946 BasicType src_elem = src_type->klass()->as_array_klass()->element_type()->basic_type();
947 if (src_elem == T_OBJECT || src_elem == T_ARRAY) {
948 return true;
949 }
950 } else {
951 return true;
952 }
953 return false;
954 }
955
956 void ShenandoahBarrierSetC2::clone_barrier_at_expansion(ArrayCopyNode* ac, Node* call, PhaseIterGVN& igvn) const {
957 assert(ac->is_clonebasic(), "no other kind of arraycopy here");
958
959 if (!clone_needs_postbarrier(ac, igvn)) {
960 BarrierSetC2::clone_barrier_at_expansion(ac, call, igvn);
961 return;
962 }
963
964 const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
965 Node* c = new ProjNode(call,TypeFunc::Control);
966 c = igvn.transform(c);
967 Node* m = new ProjNode(call, TypeFunc::Memory);
968 c = igvn.transform(m);
969
970 Node* dest = ac->in(ArrayCopyNode::Dest);
971 assert(dest->is_AddP(), "bad input");
972 Node* barrier_call = new CallLeafNode(ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type(),
973 CAST_FROM_FN_PTR(address, ShenandoahRuntime::shenandoah_clone_barrier),
974 "shenandoah_clone_barrier", raw_adr_type);
975 barrier_call->init_req(TypeFunc::Control, c);
976 barrier_call->init_req(TypeFunc::I_O , igvn.C->top());
977 barrier_call->init_req(TypeFunc::Memory , m);
978 barrier_call->init_req(TypeFunc::ReturnAdr, igvn.C->top());
979 barrier_call->init_req(TypeFunc::FramePtr, igvn.C->top());
980 barrier_call->init_req(TypeFunc::Parms+0, dest->in(AddPNode::Base));
981
982 barrier_call = igvn.transform(barrier_call);
983 c = new ProjNode(barrier_call,TypeFunc::Control);
984 c = igvn.transform(c);
985 m = new ProjNode(barrier_call, TypeFunc::Memory);
986 m = igvn.transform(m);
987
988 Node* out_c = ac->proj_out(TypeFunc::Control);
989 Node* out_m = ac->proj_out(TypeFunc::Memory);
990 igvn.replace_node(out_c, c);
991 igvn.replace_node(out_m, m);
992 }
993
994
995 // Support for macro expanded GC barriers
996 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const {
997 if (node->Opcode() == Op_ShenandoahWriteBarrier) {
998 state()->add_shenandoah_barrier((ShenandoahWriteBarrierNode*) node);
999 }
1000 }
1001
1002 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const {
1003 if (node->Opcode() == Op_ShenandoahWriteBarrier) {
1004 state()->remove_shenandoah_barrier((ShenandoahWriteBarrierNode*) node);
1005 }
1006 }
1007
1008 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* n) const {
1009 if (is_shenandoah_wb_pre_call(n)) {
1010 shenandoah_eliminate_wb_pre(n, ¯o->igvn());
1011 }
1012 }
1013
1014 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const {
1015 assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), "");
1016 Node* c = call->as_Call()->proj_out(TypeFunc::Control);
1017 c = c->unique_ctrl_out();
1018 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1019 c = c->unique_ctrl_out();
1020 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1021 Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
1022 assert(iff->is_If(), "expect test");
1023 if (!is_shenandoah_marking_if(igvn, iff)) {
1024 c = c->unique_ctrl_out();
1025 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1026 iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
1027 assert(is_shenandoah_marking_if(igvn, iff), "expect marking test");
1028 }
1029 Node* cmpx = iff->in(1)->in(1);
1030 igvn->replace_node(cmpx, igvn->makecon(TypeInt::CC_EQ));
1031 igvn->rehash_node_delayed(call);
1032 call->del_req(call->req()-1);
1033 }
1034
1035 void ShenandoahBarrierSetC2::enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const {
1036 if (node->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(node)) {
1037 igvn->add_users_to_worklist(node);
1038 }
1039 }
1040
1041 void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const {
1042 for (uint i = 0; i < useful.size(); i++) {
1043 Node* n = useful.at(i);
1044 if (n->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(n)) {
1045 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1046 C->record_for_igvn(n->fast_out(i));
1047 }
1048 }
1049 }
1050 for (int i = state()->shenandoah_barriers_count()-1; i >= 0; i--) {
1051 ShenandoahWriteBarrierNode* n = state()->shenandoah_barrier(i);
1052 if (!useful.member(n)) {
1053 state()->remove_shenandoah_barrier(n);
1054 }
1055 }
1056
1057 }
1058
1059 void ShenandoahBarrierSetC2::add_users_to_worklist(Unique_Node_List* worklist) const {}
1060
1061 void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const {
1062 return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena);
1063 }
1064
1065 ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const {
1066 return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state());
1067 }
1068
1069 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be
1070 // expanded later, then now is the time to do so.
1071 bool ShenandoahBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { return false; }
1072
1073 #ifdef ASSERT
1074 void ShenandoahBarrierSetC2::verify_gc_barriers(Compile* compile, CompilePhase phase) const {
1075 if (ShenandoahVerifyOptoBarriers && phase == BarrierSetC2::BeforeExpand) {
1076 ShenandoahBarrierNode::verify(Compile::current()->root());
1077 } else if (phase == BarrierSetC2::BeforeCodeGen) {
1078 // Verify G1 pre-barriers
1079 const int marking_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset());
1080
1081 ResourceArea *area = Thread::current()->resource_area();
1082 Unique_Node_List visited(area);
1083 Node_List worklist(area);
1084 // We're going to walk control flow backwards starting from the Root
1085 worklist.push(compile->root());
1086 while (worklist.size() > 0) {
1087 Node *x = worklist.pop();
1088 if (x == NULL || x == compile->top()) continue;
1089 if (visited.member(x)) {
1090 continue;
1091 } else {
1092 visited.push(x);
1093 }
1094
1095 if (x->is_Region()) {
1096 for (uint i = 1; i < x->req(); i++) {
1097 worklist.push(x->in(i));
1098 }
1099 } else {
1100 worklist.push(x->in(0));
1101 // We are looking for the pattern:
1102 // /->ThreadLocal
1103 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
1104 // \->ConI(0)
1105 // We want to verify that the If and the LoadB have the same control
1106 // See GraphKit::g1_write_barrier_pre()
1107 if (x->is_If()) {
1108 IfNode *iff = x->as_If();
1109 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
1110 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
1111 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
1112 && cmp->in(1)->is_Load()) {
1113 LoadNode *load = cmp->in(1)->as_Load();
1114 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
1115 && load->in(2)->in(3)->is_Con()
1116 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
1117
1118 Node *if_ctrl = iff->in(0);
1119 Node *load_ctrl = load->in(0);
1120
1121 if (if_ctrl != load_ctrl) {
1122 // Skip possible CProj->NeverBranch in infinite loops
1123 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
1124 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
1125 if_ctrl = if_ctrl->in(0)->in(0);
1126 }
1127 }
1128 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
1129 }
1130 }
1131 }
1132 }
1133 }
1134 }
1135 }
1136 }
1137 #endif
1138
1139 Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const {
1140 if (is_shenandoah_wb_pre_call(n)) {
1141 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt();
1142 if (n->req() > cnt) {
1143 Node* addp = n->in(cnt);
1144 if (has_only_shenandoah_wb_pre_uses(addp)) {
1145 n->del_req(cnt);
1146 if (can_reshape) {
1147 phase->is_IterGVN()->_worklist.push(addp);
1148 }
1149 return n;
1150 }
1151 }
1152 }
1153 if (n->Opcode() == Op_CmpP) {
1154 Node* in1 = n->in(1);
1155 Node* in2 = n->in(2);
1156 if (in1->bottom_type() == TypePtr::NULL_PTR) {
1157 in2 = step_over_gc_barrier(in2);
1158 }
1159 if (in2->bottom_type() == TypePtr::NULL_PTR) {
1160 in1 = step_over_gc_barrier(in1);
1161 }
1162 PhaseIterGVN* igvn = phase->is_IterGVN();
1163 if (in1 != n->in(1)) {
1164 if (igvn != NULL) {
1165 n->set_req_X(1, in1, igvn);
1166 } else {
1167 n->set_req(1, in1);
1168 }
1169 assert(in2 == n->in(2), "only one change");
1170 return n;
1171 }
1172 if (in2 != n->in(2)) {
1173 if (igvn != NULL) {
1174 n->set_req_X(2, in2, igvn);
1175 } else {
1176 n->set_req(2, in2);
1177 }
1178 return n;
1179 }
1180 } else if (can_reshape &&
1181 n->Opcode() == Op_If &&
1182 ShenandoahWriteBarrierNode::is_heap_stable_test(n) &&
1183 n->in(0) != NULL) {
1184 Node* dom = n->in(0);
1185 Node* prev_dom = n;
1186 int op = n->Opcode();
1187 int dist = 16;
1188 // Search up the dominator tree for another heap stable test
1189 while (dom->Opcode() != op || // Not same opcode?
1190 !ShenandoahWriteBarrierNode::is_heap_stable_test(dom) || // Not same input 1?
1191 prev_dom->in(0) != dom) { // One path of test does not dominate?
1192 if (dist < 0) return NULL;
1193
1194 dist--;
1195 prev_dom = dom;
1196 dom = IfNode::up_one_dom(dom);
1197 if (!dom) return NULL;
1198 }
1199
1200 // Check that we did not follow a loop back to ourselves
1201 if (n == dom) {
1202 return NULL;
1203 }
1204
1205 return n->as_If()->dominated_by(prev_dom, phase->is_IterGVN());
1206 }
1207
1208 return NULL;
1209 }
1210
1211 Node* ShenandoahBarrierSetC2::identity_node(PhaseGVN* phase, Node* n) const {
1212 if (n->is_Load()) {
1213 Node *mem = n->in(MemNode::Memory);
1214 Node *value = n->as_Load()->can_see_stored_value(mem, phase);
1215 if (value) {
1216 PhaseIterGVN *igvn = phase->is_IterGVN();
1217 if (igvn != NULL &&
1218 value->is_Phi() &&
1219 value->req() > 2 &&
1220 value->in(1) != NULL &&
1221 value->in(1)->is_ShenandoahBarrier()) {
1222 if (igvn->_worklist.member(value) ||
1223 igvn->_worklist.member(value->in(0)) ||
1224 (value->in(0)->in(1) != NULL &&
1225 value->in(0)->in(1)->is_IfProj() &&
1226 (igvn->_worklist.member(value->in(0)->in(1)) ||
1227 (value->in(0)->in(1)->in(0) != NULL &&
1228 igvn->_worklist.member(value->in(0)->in(1)->in(0)))))) {
1229 igvn->_worklist.push(n);
1230 return n;
1231 }
1232 }
1233 // (This works even when value is a Con, but LoadNode::Value
1234 // usually runs first, producing the singleton type of the Con.)
1235 Node *value_no_barrier = step_over_gc_barrier(value->Opcode() == Op_EncodeP ? value->in(1) : value);
1236 if (value->Opcode() == Op_EncodeP) {
1237 if (value_no_barrier != value->in(1)) {
1238 Node *encode = value->clone();
1239 encode->set_req(1, value_no_barrier);
1240 encode = phase->transform(encode);
1241 return encode;
1242 }
1243 } else {
1244 return value_no_barrier;
1245 }
1246 }
1247 }
1248 return n;
1249 }
1250
1251 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) {
1252 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1253 Node* u = n->fast_out(i);
1254 if (!is_shenandoah_wb_pre_call(u)) {
1255 return false;
1256 }
1257 }
1258 return n->outcnt() > 0;
1259 }
1260
1261 bool ShenandoahBarrierSetC2::flatten_gc_alias_type(const TypePtr*& adr_type) const {
1262 int offset = adr_type->offset();
1263 if (offset == ShenandoahBrooksPointer::byte_offset()) {
1264 if (adr_type->isa_aryptr()) {
1265 adr_type = TypeAryPtr::make(adr_type->ptr(), adr_type->isa_aryptr()->ary(), adr_type->isa_aryptr()->klass(), false, offset);
1266 } else if (adr_type->isa_instptr()) {
1267 adr_type = TypeInstPtr::make(adr_type->ptr(), ciEnv::current()->Object_klass(), false, NULL, offset);
1268 }
1269 return true;
1270 } else {
1271 return false;
1272 }
1273 }
1274
1275 bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode) const {
1276 switch (opcode) {
1277 case Op_CallLeaf:
1278 case Op_CallLeafNoFP: {
1279 assert (n->is_Call(), "");
1280 CallNode *call = n->as_Call();
1281 if (ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(call)) {
1282 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt();
1283 if (call->req() > cnt) {
1284 assert(call->req() == cnt + 1, "only one extra input");
1285 Node *addp = call->in(cnt);
1286 assert(!ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(addp), "useless address computation?");
1287 call->del_req(cnt);
1288 }
1289 }
1290 return false;
1291 }
1292 case Op_ShenandoahCompareAndSwapP:
1293 case Op_ShenandoahCompareAndSwapN:
1294 case Op_ShenandoahWeakCompareAndSwapN:
1295 case Op_ShenandoahWeakCompareAndSwapP:
1296 case Op_ShenandoahCompareAndExchangeP:
1297 case Op_ShenandoahCompareAndExchangeN:
1298 #ifdef ASSERT
1299 if( VerifyOptoOopOffsets ) {
1300 MemNode* mem = n->as_Mem();
1301 // Check to see if address types have grounded out somehow.
1302 const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
1303 ciInstanceKlass *k = tp->klass()->as_instance_klass();
1304 bool oop_offset_is_sane = k->contains_field_offset(tp->offset());
1305 assert( !tp || oop_offset_is_sane, "" );
1306 }
1307 #endif
1308 return true;
1309 case Op_ShenandoahReadBarrier:
1310 return true;
1311 case Op_ShenandoahWriteBarrier:
1312 assert(false, "should have been expanded already");
1313 return true;
1314 default:
1315 return false;
1316 }
1317 }
1318
1319 #ifdef ASSERT
1320 bool ShenandoahBarrierSetC2::verify_gc_alias_type(const TypePtr* adr_type, int offset) const {
1321 if (offset == ShenandoahBrooksPointer::byte_offset() &&
1322 (adr_type->base() == Type::AryPtr || adr_type->base() == Type::OopPtr)) {
1323 return true;
1324 } else {
1325 return false;
1326 }
1327 }
1328 #endif
1329