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
36 ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() {
37 return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2());
38 }
39
40 ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena)
41 : _shenandoah_barriers(new (comp_arena) GrowableArray<ShenandoahWriteBarrierNode*>(comp_arena, 8, 0, NULL)) {
42 }
43
44 int ShenandoahBarrierSetC2State::shenandoah_barriers_count() const {
45 return _shenandoah_barriers->length();
46 }
47
48 ShenandoahWriteBarrierNode* ShenandoahBarrierSetC2State::shenandoah_barrier(int idx) const {
49 return _shenandoah_barriers->at(idx);
50 }
51
52 void ShenandoahBarrierSetC2State::add_shenandoah_barrier(ShenandoahWriteBarrierNode * n) {
53 assert(!_shenandoah_barriers->contains(n), "duplicate entry in barrier list");
54 _shenandoah_barriers->append(n);
55 }
56
57 void ShenandoahBarrierSetC2State::remove_shenandoah_barrier(ShenandoahWriteBarrierNode * n) {
58 if (_shenandoah_barriers->contains(n)) {
59 _shenandoah_barriers->remove(n);
60 }
61 }
62
63 #define __ kit->
64
65 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier(GraphKit* kit, Node* obj) const {
66 if (ShenandoahReadBarrier) {
67 obj = shenandoah_read_barrier_impl(kit, obj, false, true, true);
68 }
69 return obj;
70 }
71
72 Node* ShenandoahBarrierSetC2::shenandoah_storeval_barrier(GraphKit* kit, Node* obj) const {
73 if (ShenandoahStoreValEnqueueBarrier) {
74 obj = shenandoah_write_barrier(kit, obj);
75 obj = shenandoah_enqueue_barrier(kit, obj);
76 }
77 if (ShenandoahStoreValReadBarrier) {
78 obj = shenandoah_read_barrier_impl(kit, obj, true, false, false);
79 }
80 return obj;
81 }
82
83 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier_acmp(GraphKit* kit, Node* obj) {
84 return shenandoah_read_barrier_impl(kit, obj, true, true, false);
85 }
86
87 Node* ShenandoahBarrierSetC2::shenandoah_read_barrier_impl(GraphKit* kit, Node* obj, bool use_ctrl, bool use_mem, bool allow_fromspace) const {
88 const Type* obj_type = obj->bottom_type();
89 if (obj_type->higher_equal(TypePtr::NULL_PTR)) {
90 return obj;
91 }
92 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type);
93 Node* mem = use_mem ? __ memory(adr_type) : __ immutable_memory();
94
95 if (! ShenandoahBarrierNode::needs_barrier(&__ gvn(), NULL, obj, mem, allow_fromspace)) {
96 // We know it is null, no barrier needed.
97 return obj;
98 }
99
100 if (obj_type->meet(TypePtr::NULL_PTR) == obj_type->remove_speculative()) {
101
102 // We don't know if it's null or not. Need null-check.
103 enum { _not_null_path = 1, _null_path, PATH_LIMIT };
104 RegionNode* region = new RegionNode(PATH_LIMIT);
105 Node* phi = new PhiNode(region, obj_type);
106 Node* null_ctrl = __ top();
107 Node* not_null_obj = __ null_check_oop(obj, &null_ctrl);
108
109 region->init_req(_null_path, null_ctrl);
110 phi ->init_req(_null_path, __ zerocon(T_OBJECT));
111
112 Node* ctrl = use_ctrl ? __ control() : NULL;
113 ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, not_null_obj, allow_fromspace);
114 Node* n = __ gvn().transform(rb);
115
116 region->init_req(_not_null_path, __ control());
117 phi ->init_req(_not_null_path, n);
118
119 __ set_control(__ gvn().transform(region));
120 __ record_for_igvn(region);
121 return __ gvn().transform(phi);
122
123 } else {
124 // We know it is not null. Simple barrier is sufficient.
125 Node* ctrl = use_ctrl ? __ control() : NULL;
126 ShenandoahReadBarrierNode* rb = new ShenandoahReadBarrierNode(ctrl, mem, obj, allow_fromspace);
127 Node* n = __ gvn().transform(rb);
128 __ record_for_igvn(n);
129 return n;
130 }
131 }
132
133 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier_helper(GraphKit* kit, Node* obj, const TypePtr* adr_type) const {
134 ShenandoahWriteBarrierNode* wb = new ShenandoahWriteBarrierNode(kit->C, kit->control(), kit->memory(adr_type), obj);
135 Node* n = __ gvn().transform(wb);
136 if (n == wb) { // New barrier needs memory projection.
137 Node* proj = __ gvn().transform(new ShenandoahWBMemProjNode(n));
138 __ set_memory(proj, adr_type);
139 }
140 return n;
141 }
142
143 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier(GraphKit* kit, Node* obj) const {
144 if (ShenandoahWriteBarrier) {
145 obj = shenandoah_write_barrier_impl(kit, obj);
146 }
147 return obj;
148 }
149
150 Node* ShenandoahBarrierSetC2::shenandoah_write_barrier_impl(GraphKit* kit, Node* obj) const {
151 if (! ShenandoahBarrierNode::needs_barrier(&__ gvn(), NULL, obj, NULL, true)) {
152 return obj;
153 }
154 const Type* obj_type = obj->bottom_type();
155 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(obj_type);
156 Node* n = shenandoah_write_barrier_helper(kit, obj, adr_type);
157 __ record_for_igvn(n);
158 return n;
159 }
160
161 bool ShenandoahBarrierSetC2::satb_can_remove_pre_barrier(GraphKit* kit, PhaseTransform* phase, Node* adr,
162 BasicType bt, uint adr_idx) const {
163 intptr_t offset = 0;
164 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
165 AllocateNode* alloc = AllocateNode::Ideal_allocation(base, phase);
166
167 if (offset == Type::OffsetBot) {
168 return false; // cannot unalias unless there are precise offsets
169 }
170
171 if (alloc == NULL) {
172 return false; // No allocation found
173 }
174
175 intptr_t size_in_bytes = type2aelembytes(bt);
176
177 Node* mem = __ memory(adr_idx); // start searching here...
178
179 for (int cnt = 0; cnt < 50; cnt++) {
180
181 if (mem->is_Store()) {
182
183 Node* st_adr = mem->in(MemNode::Address);
184 intptr_t st_offset = 0;
185 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
186
187 if (st_base == NULL) {
188 break; // inscrutable pointer
189 }
190
191 // Break we have found a store with same base and offset as ours so break
192 if (st_base == base && st_offset == offset) {
193 break;
194 }
195
196 if (st_offset != offset && st_offset != Type::OffsetBot) {
197 const int MAX_STORE = BytesPerLong;
198 if (st_offset >= offset + size_in_bytes ||
199 st_offset <= offset - MAX_STORE ||
200 st_offset <= offset - mem->as_Store()->memory_size()) {
201 // Success: The offsets are provably independent.
202 // (You may ask, why not just test st_offset != offset and be done?
203 // The answer is that stores of different sizes can co-exist
204 // in the same sequence of RawMem effects. We sometimes initialize
205 // a whole 'tile' of array elements with a single jint or jlong.)
206 mem = mem->in(MemNode::Memory);
207 continue; // advance through independent store memory
208 }
209 }
210
211 if (st_base != base
212 && MemNode::detect_ptr_independence(base, alloc, st_base,
213 AllocateNode::Ideal_allocation(st_base, phase),
214 phase)) {
215 // Success: The bases are provably independent.
216 mem = mem->in(MemNode::Memory);
217 continue; // advance through independent store memory
218 }
219 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
220
221 InitializeNode* st_init = mem->in(0)->as_Initialize();
222 AllocateNode* st_alloc = st_init->allocation();
223
224 // Make sure that we are looking at the same allocation site.
225 // The alloc variable is guaranteed to not be null here from earlier check.
226 if (alloc == st_alloc) {
227 // Check that the initialization is storing NULL so that no previous store
228 // has been moved up and directly write a reference
229 Node* captured_store = st_init->find_captured_store(offset,
230 type2aelembytes(T_OBJECT),
231 phase);
232 if (captured_store == NULL || captured_store == st_init->zero_memory()) {
233 return true;
234 }
235 }
236 }
237
238 // Unless there is an explicit 'continue', we must bail out here,
239 // because 'mem' is an inscrutable memory state (e.g., a call).
240 break;
241 }
242
243 return false;
244 }
245
246 #undef __
247 #define __ ideal.
248
249 void ShenandoahBarrierSetC2::satb_write_barrier_pre(GraphKit* kit,
250 bool do_load,
251 Node* obj,
252 Node* adr,
253 uint alias_idx,
254 Node* val,
255 const TypeOopPtr* val_type,
256 Node* pre_val,
257 BasicType bt) const {
258 // Some sanity checks
259 // Note: val is unused in this routine.
260
261 if (do_load) {
262 // We need to generate the load of the previous value
263 assert(obj != NULL, "must have a base");
264 assert(adr != NULL, "where are loading from?");
265 assert(pre_val == NULL, "loaded already?");
266 assert(val_type != NULL, "need a type");
267
268 if (ReduceInitialCardMarks
269 && satb_can_remove_pre_barrier(kit, &kit->gvn(), adr, bt, alias_idx)) {
270 return;
271 }
272
273 } else {
274 // In this case both val_type and alias_idx are unused.
275 assert(pre_val != NULL, "must be loaded already");
276 // Nothing to be done if pre_val is null.
277 if (pre_val->bottom_type() == TypePtr::NULL_PTR) return;
278 assert(pre_val->bottom_type()->basic_type() == T_OBJECT, "or we shouldn't be here");
279 }
280 assert(bt == T_OBJECT, "or we shouldn't be here");
281
282 IdealKit ideal(kit, true);
283
284 Node* tls = __ thread(); // ThreadLocalStorage
285
286 Node* no_base = __ top();
287 Node* zero = __ ConI(0);
288 Node* zeroX = __ ConX(0);
289
290 float likely = PROB_LIKELY(0.999);
291 float unlikely = PROB_UNLIKELY(0.999);
292
293 // Offsets into the thread
294 const int index_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_index_offset());
295 const int buffer_offset = in_bytes(ShenandoahThreadLocalData::satb_mark_queue_buffer_offset());
296
297 // Now the actual pointers into the thread
298 Node* buffer_adr = __ AddP(no_base, tls, __ ConX(buffer_offset));
299 Node* index_adr = __ AddP(no_base, tls, __ ConX(index_offset));
300
301 // Now some of the values
302 Node* marking;
303 Node* gc_state = __ AddP(no_base, tls, __ ConX(in_bytes(ShenandoahThreadLocalData::gc_state_offset())));
304 Node* ld = __ load(__ ctrl(), gc_state, TypeInt::BYTE, T_BYTE, Compile::AliasIdxRaw);
305 marking = __ AndI(ld, __ ConI(ShenandoahHeap::MARKING));
306 assert(ShenandoahWriteBarrierNode::is_gc_state_load(ld), "Should match the shape");
307
308 // if (!marking)
309 __ if_then(marking, BoolTest::ne, zero, unlikely); {
310 BasicType index_bt = TypeX_X->basic_type();
311 assert(sizeof(size_t) == type2aelembytes(index_bt), "Loading G1 SATBMarkQueue::_index with wrong size.");
312 Node* index = __ load(__ ctrl(), index_adr, TypeX_X, index_bt, Compile::AliasIdxRaw);
313
314 if (do_load) {
315 // load original value
316 // alias_idx correct??
317 pre_val = __ load(__ ctrl(), adr, val_type, bt, alias_idx);
318 }
319
320 // if (pre_val != NULL)
321 __ if_then(pre_val, BoolTest::ne, kit->null()); {
322 Node* buffer = __ load(__ ctrl(), buffer_adr, TypeRawPtr::NOTNULL, T_ADDRESS, Compile::AliasIdxRaw);
323
324 // is the queue for this thread full?
325 __ if_then(index, BoolTest::ne, zeroX, likely); {
326
327 // decrement the index
328 Node* next_index = kit->gvn().transform(new SubXNode(index, __ ConX(sizeof(intptr_t))));
329
330 // Now get the buffer location we will log the previous value into and store it
331 Node *log_addr = __ AddP(no_base, buffer, next_index);
332 __ store(__ ctrl(), log_addr, pre_val, T_OBJECT, Compile::AliasIdxRaw, MemNode::unordered);
333 // update the index
334 __ store(__ ctrl(), index_adr, next_index, index_bt, Compile::AliasIdxRaw, MemNode::unordered);
335
336 } __ else_(); {
337
338 // logging buffer is full, call the runtime
339 const TypeFunc *tf = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type();
340 __ make_leaf_call(tf, CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry), "shenandoah_wb_pre", pre_val, tls);
341 } __ end_if(); // (!index)
342 } __ end_if(); // (pre_val != NULL)
343 } __ end_if(); // (!marking)
344
345 // Final sync IdealKit and GraphKit.
346 kit->final_sync(ideal);
347
348 if (ShenandoahSATBBarrier && adr != NULL) {
349 Node* c = kit->control();
350 Node* call = c->in(1)->in(1)->in(1)->in(0);
351 assert(is_shenandoah_wb_pre_call(call), "shenandoah_wb_pre call expected");
352 call->add_req(adr);
353 }
354 }
355
356 bool ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(Node* call) {
357 return call->is_CallLeaf() &&
358 call->as_CallLeaf()->entry_point() == CAST_FROM_FN_PTR(address, ShenandoahRuntime::write_ref_field_pre_entry);
359 }
360
361 bool ShenandoahBarrierSetC2::is_shenandoah_marking_if(PhaseTransform *phase, Node* n) {
362 if (n->Opcode() != Op_If) {
363 return false;
364 }
365
366 Node* bol = n->in(1);
367 assert(bol->is_Bool(), "");
368 Node* cmpx = bol->in(1);
369 if (bol->as_Bool()->_test._test == BoolTest::ne &&
370 cmpx->is_Cmp() && cmpx->in(2) == phase->intcon(0) &&
371 is_shenandoah_state_load(cmpx->in(1)->in(1)) &&
372 cmpx->in(1)->in(2)->is_Con() &&
373 cmpx->in(1)->in(2) == phase->intcon(ShenandoahHeap::MARKING)) {
374 return true;
375 }
376
377 return false;
378 }
379
380 bool ShenandoahBarrierSetC2::is_shenandoah_state_load(Node* n) {
381 if (!n->is_Load()) return false;
382 const int state_offset = in_bytes(ShenandoahThreadLocalData::gc_state_offset());
383 return n->in(2)->is_AddP() && n->in(2)->in(2)->Opcode() == Op_ThreadLocal
384 && n->in(2)->in(3)->is_Con()
385 && n->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == state_offset;
386 }
387
388 void ShenandoahBarrierSetC2::shenandoah_write_barrier_pre(GraphKit* kit,
389 bool do_load,
390 Node* obj,
391 Node* adr,
392 uint alias_idx,
393 Node* val,
394 const TypeOopPtr* val_type,
395 Node* pre_val,
396 BasicType bt) const {
397 if (ShenandoahSATBBarrier) {
398 IdealKit ideal(kit);
399 kit->sync_kit(ideal);
400
401 satb_write_barrier_pre(kit, do_load, obj, adr, alias_idx, val, val_type, pre_val, bt);
402
403 ideal.sync_kit(kit);
404 kit->final_sync(ideal);
405 }
406 }
407
408 Node* ShenandoahBarrierSetC2::shenandoah_enqueue_barrier(GraphKit* kit, Node* pre_val) const {
409 return kit->gvn().transform(new ShenandoahEnqueueBarrierNode(pre_val));
410 }
411
412 // Helper that guards and inserts a pre-barrier.
413 void ShenandoahBarrierSetC2::insert_pre_barrier(GraphKit* kit, Node* base_oop, Node* offset,
414 Node* pre_val, bool need_mem_bar) const {
415 // We could be accessing the referent field of a reference object. If so, when G1
416 // is enabled, we need to log the value in the referent field in an SATB buffer.
417 // This routine performs some compile time filters and generates suitable
418 // runtime filters that guard the pre-barrier code.
419 // Also add memory barrier for non volatile load from the referent field
420 // to prevent commoning of loads across safepoint.
421
422 // Some compile time checks.
423
424 // If offset is a constant, is it java_lang_ref_Reference::_reference_offset?
425 const TypeX* otype = offset->find_intptr_t_type();
426 if (otype != NULL && otype->is_con() &&
427 otype->get_con() != java_lang_ref_Reference::referent_offset) {
428 // Constant offset but not the reference_offset so just return
429 return;
430 }
431
432 // We only need to generate the runtime guards for instances.
433 const TypeOopPtr* btype = base_oop->bottom_type()->isa_oopptr();
434 if (btype != NULL) {
435 if (btype->isa_aryptr()) {
436 // Array type so nothing to do
437 return;
438 }
439
440 const TypeInstPtr* itype = btype->isa_instptr();
441 if (itype != NULL) {
442 // Can the klass of base_oop be statically determined to be
443 // _not_ a sub-class of Reference and _not_ Object?
444 ciKlass* klass = itype->klass();
445 if ( klass->is_loaded() &&
446 !klass->is_subtype_of(kit->env()->Reference_klass()) &&
447 !kit->env()->Object_klass()->is_subtype_of(klass)) {
448 return;
449 }
450 }
451 }
452
453 // The compile time filters did not reject base_oop/offset so
454 // we need to generate the following runtime filters
455 //
456 // if (offset == java_lang_ref_Reference::_reference_offset) {
457 // if (instance_of(base, java.lang.ref.Reference)) {
458 // pre_barrier(_, pre_val, ...);
459 // }
460 // }
461
462 float likely = PROB_LIKELY( 0.999);
463 float unlikely = PROB_UNLIKELY(0.999);
464
465 IdealKit ideal(kit);
466
467 Node* referent_off = __ ConX(java_lang_ref_Reference::referent_offset);
468
469 __ if_then(offset, BoolTest::eq, referent_off, unlikely); {
470 // Update graphKit memory and control from IdealKit.
471 kit->sync_kit(ideal);
472
473 Node* ref_klass_con = kit->makecon(TypeKlassPtr::make(kit->env()->Reference_klass()));
474 Node* is_instof = kit->gen_instanceof(base_oop, ref_klass_con);
475
476 // Update IdealKit memory and control from graphKit.
477 __ sync_kit(kit);
478
479 Node* one = __ ConI(1);
480 // is_instof == 0 if base_oop == NULL
481 __ if_then(is_instof, BoolTest::eq, one, unlikely); {
482
483 // Update graphKit from IdeakKit.
484 kit->sync_kit(ideal);
485
486 // Use the pre-barrier to record the value in the referent field
487 satb_write_barrier_pre(kit, false /* do_load */,
488 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */,
489 pre_val /* pre_val */,
490 T_OBJECT);
491 if (need_mem_bar) {
492 // Add memory barrier to prevent commoning reads from this field
493 // across safepoint since GC can change its value.
494 kit->insert_mem_bar(Op_MemBarCPUOrder);
495 }
496 // Update IdealKit from graphKit.
497 __ sync_kit(kit);
498
499 } __ end_if(); // _ref_type != ref_none
500 } __ end_if(); // offset == referent_offset
501
502 // Final sync IdealKit and GraphKit.
503 kit->final_sync(ideal);
504 }
505
506 #undef __
507
508 const TypeFunc* ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type() {
509 const Type **fields = TypeTuple::fields(2);
510 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
511 fields[TypeFunc::Parms+1] = TypeRawPtr::NOTNULL; // thread
512 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields);
513
514 // create result type (range)
515 fields = TypeTuple::fields(0);
516 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields);
517
518 return TypeFunc::make(domain, range);
519 }
520
521 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type() {
522 const Type **fields = TypeTuple::fields(1);
523 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
524 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields);
525
526 // create result type (range)
527 fields = TypeTuple::fields(0);
528 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+0, fields);
529
530 return TypeFunc::make(domain, range);
531 }
532
533 const TypeFunc* ShenandoahBarrierSetC2::shenandoah_write_barrier_Type() {
534 const Type **fields = TypeTuple::fields(1);
535 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; // original field value
536 const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+1, fields);
537
538 // create result type (range)
539 fields = TypeTuple::fields(1);
540 fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL;
541 const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields);
542
543 return TypeFunc::make(domain, range);
544 }
545
546 void ShenandoahBarrierSetC2::resolve_address(C2Access& access) const {
547 const TypePtr* adr_type = access.addr().type();
548
549 if ((access.decorators() & IN_NATIVE) == 0 && (adr_type->isa_instptr() || adr_type->isa_aryptr())) {
550 int off = adr_type->is_ptr()->offset();
551 int base_off = adr_type->isa_instptr() ? instanceOopDesc::base_offset_in_bytes() :
552 arrayOopDesc::base_offset_in_bytes(adr_type->is_aryptr()->elem()->array_element_basic_type());
553 assert(off != Type::OffsetTop, "unexpected offset");
554 if (off == Type::OffsetBot || off >= base_off) {
555 DecoratorSet decorators = access.decorators();
556 bool is_write = (decorators & C2_WRITE_ACCESS) != 0;
557 GraphKit* kit = access.kit();
558 Node* adr = access.addr().node();
559 assert(adr->is_AddP(), "unexpected address shape");
560 Node* base = adr->in(AddPNode::Base);
561
562 if (is_write) {
563 base = shenandoah_write_barrier(kit, base);
564 } else {
565 if (adr_type->isa_instptr()) {
566 Compile* C = kit->C;
567 ciField* field = C->alias_type(adr_type)->field();
568
569 // Insert read barrier for Shenandoah.
570 if (field != NULL &&
571 ((ShenandoahOptimizeStaticFinals && field->is_static() && field->is_final()) ||
572 (ShenandoahOptimizeInstanceFinals && !field->is_static() && field->is_final()) ||
573 (ShenandoahOptimizeStableFinals && field->is_stable()))) {
574 // Skip the barrier for special fields
575 } else {
576 base = shenandoah_read_barrier(kit, base);
577 }
578 } else {
579 base = shenandoah_read_barrier(kit, base);
580 }
581 }
582 if (base != adr->in(AddPNode::Base)) {
583 Node* address = adr->in(AddPNode::Address);
584
585 if (address->is_AddP()) {
586 assert(address->in(AddPNode::Base) == adr->in(AddPNode::Base), "unexpected address shape");
587 assert(!address->in(AddPNode::Address)->is_AddP(), "unexpected address shape");
588 assert(address->in(AddPNode::Address) == adr->in(AddPNode::Base), "unexpected address shape");
589 address = address->clone();
590 address->set_req(AddPNode::Base, base);
591 address->set_req(AddPNode::Address, base);
592 address = kit->gvn().transform(address);
593 } else {
594 assert(address == adr->in(AddPNode::Base), "unexpected address shape");
595 address = base;
596 }
597 adr = adr->clone();
598 adr->set_req(AddPNode::Base, base);
599 adr->set_req(AddPNode::Address, address);
600 adr = kit->gvn().transform(adr);
601 access.addr().set_node(adr);
602 }
603 }
604 }
605 }
606
607 Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const {
608 DecoratorSet decorators = access.decorators();
609 GraphKit* kit = access.kit();
610
611 const TypePtr* adr_type = access.addr().type();
612 Node* adr = access.addr().node();
613
614 bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
615 bool on_heap = (decorators & IN_HEAP) != 0;
616
617 if (!access.is_oop() || (!on_heap && !anonymous)) {
618 return BarrierSetC2::store_at_resolved(access, val);
619 }
620
621 uint adr_idx = kit->C->get_alias_index(adr_type);
622 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
623 Node* value = val.node();
624 value = shenandoah_storeval_barrier(kit, value);
625 val.set_node(value);
626 shenandoah_write_barrier_pre(kit, true /* do_load */, /*kit->control(),*/ access.base(), adr, adr_idx, val.node(),
627 static_cast<const TypeOopPtr*>(val.type()), NULL /* pre_val */, access.type());
628 return BarrierSetC2::store_at_resolved(access, val);
629 }
630
631 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
632 DecoratorSet decorators = access.decorators();
633 GraphKit* kit = access.kit();
634
635 Node* adr = access.addr().node();
636 Node* obj = access.base();
637
638 bool mismatched = (decorators & C2_MISMATCHED) != 0;
639 bool unknown = (decorators & ON_UNKNOWN_OOP_REF) != 0;
640 bool on_heap = (decorators & IN_HEAP) != 0;
641 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
642 bool is_unordered = (decorators & MO_UNORDERED) != 0;
643 bool need_cpu_mem_bar = !is_unordered || mismatched || !on_heap;
644
645 Node* offset = adr->is_AddP() ? adr->in(AddPNode::Offset) : kit->top();
646 Node* load = BarrierSetC2::load_at_resolved(access, val_type);
647
648 // If we are reading the value of the referent field of a Reference
649 // object (either by using Unsafe directly or through reflection)
650 // then, if SATB is enabled, we need to record the referent in an
651 // SATB log buffer using the pre-barrier mechanism.
652 // Also we need to add memory barrier to prevent commoning reads
653 // from this field across safepoint since GC can change its value.
654 bool need_read_barrier = ShenandoahKeepAliveBarrier &&
655 (on_heap && (on_weak || (unknown && offset != kit->top() && obj != kit->top())));
656
657 if (!access.is_oop() || !need_read_barrier) {
658 return load;
659 }
660
661 if (on_weak) {
662 // Use the pre-barrier to record the value in the referent field
663 satb_write_barrier_pre(kit, false /* do_load */,
664 NULL /* obj */, NULL /* adr */, max_juint /* alias_idx */, NULL /* val */, NULL /* val_type */,
665 load /* pre_val */, T_OBJECT);
666 // Add memory barrier to prevent commoning reads from this field
667 // across safepoint since GC can change its value.
668 kit->insert_mem_bar(Op_MemBarCPUOrder);
669 } else if (unknown) {
670 // We do not require a mem bar inside pre_barrier if need_mem_bar
671 // is set: the barriers would be emitted by us.
672 insert_pre_barrier(kit, obj, offset, load, !need_cpu_mem_bar);
673 }
674
675 return load;
676 }
677
678 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicAccess& access, Node* expected_val,
679 Node* new_val, const Type* value_type) const {
680 GraphKit* kit = access.kit();
681 if (access.is_oop()) {
682 new_val = shenandoah_storeval_barrier(kit, new_val);
683 shenandoah_write_barrier_pre(kit, false /* do_load */,
684 NULL, NULL, max_juint, NULL, NULL,
685 expected_val /* pre_val */, T_OBJECT);
686
687 MemNode::MemOrd mo = access.mem_node_mo();
688 Node* mem = access.memory();
689 Node* adr = access.addr().node();
690 const TypePtr* adr_type = access.addr().type();
691 Node* load_store = NULL;
692
693 #ifdef _LP64
694 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
695 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop()));
696 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop()));
697 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo));
698 } else
699 #endif
700 {
701 load_store = kit->gvn().transform(new ShenandoahCompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo));
702 }
703
704 access.set_raw_access(load_store);
705 pin_atomic_op(access);
706
707 #ifdef _LP64
708 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
709 return kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type()));
710 }
711 #endif
712 return load_store;
713 }
714 return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);
715 }
716
717 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicAccess& access, Node* expected_val,
718 Node* new_val, const Type* value_type) const {
719 GraphKit* kit = access.kit();
720 if (access.is_oop()) {
721 new_val = shenandoah_storeval_barrier(kit, new_val);
722 shenandoah_write_barrier_pre(kit, false /* do_load */,
723 NULL, NULL, max_juint, NULL, NULL,
724 expected_val /* pre_val */, T_OBJECT);
725 DecoratorSet decorators = access.decorators();
726 MemNode::MemOrd mo = access.mem_node_mo();
727 Node* mem = access.memory();
728 bool is_weak_cas = (decorators & C2_WEAK_CMPXCHG) != 0;
729 Node* load_store = NULL;
730 Node* adr = access.addr().node();
731 #ifdef _LP64
732 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
733 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop()));
734 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop()));
735 if (is_weak_cas) {
736 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo));
737 } else {
738 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo));
739 }
740 } else
741 #endif
742 {
743 if (is_weak_cas) {
744 load_store = kit->gvn().transform(new ShenandoahWeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
745 } else {
746 load_store = kit->gvn().transform(new ShenandoahCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo));
747 }
748 }
749 access.set_raw_access(load_store);
750 pin_atomic_op(access);
751 return load_store;
752 }
753 return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
754 }
755
756 Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicAccess& access, Node* val, const Type* value_type) const {
757 GraphKit* kit = access.kit();
758 if (access.is_oop()) {
759 val = shenandoah_storeval_barrier(kit, val);
760 }
761 Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type);
762 if (access.is_oop()) {
763 shenandoah_write_barrier_pre(kit, false /* do_load */,
764 NULL, NULL, max_juint, NULL, NULL,
765 result /* pre_val */, T_OBJECT);
766 }
767 return result;
768 }
769
770 void ShenandoahBarrierSetC2::clone(GraphKit* kit, Node* src, Node* dst, Node* size, bool is_array) const {
771 assert(!src->is_AddP(), "unexpected input");
772 src = shenandoah_read_barrier(kit, src);
773 BarrierSetC2::clone(kit, src, dst, size, is_array);
774 }
775
776 Node* ShenandoahBarrierSetC2::resolve(GraphKit* kit, Node* n, DecoratorSet decorators) const {
777 bool is_write = decorators & ACCESS_WRITE;
778 if (is_write) {
779 return shenandoah_write_barrier(kit, n);
780 } else {
781 return shenandoah_read_barrier(kit, n);
782 }
783 }
784
785 Node* ShenandoahBarrierSetC2::obj_allocate(PhaseMacroExpand* macro, Node* ctrl, Node* mem, Node* toobig_false, Node* size_in_bytes,
786 Node*& i_o, Node*& needgc_ctrl,
787 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem,
788 intx prefetch_lines) const {
789 PhaseIterGVN& igvn = macro->igvn();
790
791 // Allocate several words more for the Shenandoah brooks pointer.
792 size_in_bytes = new AddXNode(size_in_bytes, igvn.MakeConX(BrooksPointer::byte_size()));
793 macro->transform_later(size_in_bytes);
794
795 Node* fast_oop = BarrierSetC2::obj_allocate(macro, ctrl, mem, toobig_false, size_in_bytes,
796 i_o, needgc_ctrl, fast_oop_ctrl, fast_oop_rawmem,
797 prefetch_lines);
798
799 // Bump up object for Shenandoah brooks pointer.
800 fast_oop = new AddPNode(macro->top(), fast_oop, igvn.MakeConX(BrooksPointer::byte_size()));
801 macro->transform_later(fast_oop);
802
803 // Initialize Shenandoah brooks pointer to point to the object itself.
804 fast_oop_rawmem = macro->make_store(fast_oop_ctrl, fast_oop_rawmem, fast_oop, BrooksPointer::byte_offset(), fast_oop, T_OBJECT);
805
806 return fast_oop;
807 }
808
809 // Support for GC barriers emitted during parsing
810 bool ShenandoahBarrierSetC2::is_gc_barrier_node(Node* node) const {
811 if (node->Opcode() != Op_CallLeaf) {
812 return false;
813 }
814 CallLeafNode *call = node->as_CallLeaf();
815 if (call->_name == NULL) {
816 return false;
817 }
818
819 return strcmp(call->_name, "shenandoah_clone_barrier") == 0 ||
820 strcmp(call->_name, "shenandoah_cas_obj") == 0 ||
821 strcmp(call->_name, "shenandoah_wb_pre") == 0;
822 }
823
824 Node* ShenandoahBarrierSetC2::step_over_gc_barrier(Node* c) const {
825 return ShenandoahBarrierNode::skip_through_barrier(c);
826 }
827
828 bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, ArrayCopyPhase phase) const {
829 bool is_oop = type == T_OBJECT || type == T_ARRAY;
830 if (!is_oop) {
831 return false;
832 }
833
834 if (tightly_coupled_alloc) {
835 if (phase == Optimization) {
836 return false;
837 }
838 return !is_clone;
839 }
840 if (phase == Optimization) {
841 return !ShenandoahStoreValEnqueueBarrier;
842 }
843 return true;
844 }
845
846 Node* ShenandoahBarrierSetC2::array_copy_load_store_barrier(PhaseGVN *phase, bool can_reshape, Node* v, MergeMemNode* mem, Node*& ctl) const {
847 if (ShenandoahStoreValReadBarrier) {
848 RegionNode* region = new RegionNode(3);
849 const Type* v_t = phase->type(v);
850 Node* phi = new PhiNode(region, v_t->isa_oopptr() ? v_t->is_oopptr()->cast_to_nonconst() : v_t);
851 Node* cmp = phase->transform(new CmpPNode(v, phase->zerocon(T_OBJECT)));
852 Node* bol = phase->transform(new BoolNode(cmp, BoolTest::ne));
853 IfNode* iff = new IfNode(ctl, bol, PROB_LIKELY_MAG(3), COUNT_UNKNOWN);
854
855 phase->transform(iff);
856 if (can_reshape) {
857 phase->is_IterGVN()->_worklist.push(iff);
858 } else {
859 phase->record_for_igvn(iff);
860 }
861
862 Node* null_true = phase->transform(new IfFalseNode(iff));
863 Node* null_false = phase->transform(new IfTrueNode(iff));
864 region->init_req(1, null_true);
865 region->init_req(2, null_false);
866 phi->init_req(1, phase->zerocon(T_OBJECT));
867 Node* cast = new CastPPNode(v, phase->type(v)->join_speculative(TypePtr::NOTNULL));
868 cast->set_req(0, null_false);
869 cast = phase->transform(cast);
870 Node* rb = phase->transform(new ShenandoahReadBarrierNode(null_false, phase->C->immutable_memory(), cast, false));
871 phi->init_req(2, rb);
872 ctl = phase->transform(region);
873 return phase->transform(phi);
874 }
875 if (ShenandoahStoreValEnqueueBarrier) {
876 const TypePtr* adr_type = ShenandoahBarrierNode::brooks_pointer_type(phase->type(v));
877 int alias = phase->C->get_alias_index(adr_type);
878 Node* wb = new ShenandoahWriteBarrierNode(phase->C, ctl, mem->memory_at(alias), v);
879 Node* wb_transformed = phase->transform(wb);
880 Node* enqueue = phase->transform(new ShenandoahEnqueueBarrierNode(wb_transformed));
881 if (wb_transformed == wb) {
882 Node* proj = phase->transform(new ShenandoahWBMemProjNode(wb));
883 mem->set_memory_at(alias, proj);
884 }
885 return enqueue;
886 }
887 return v;
888 }
889
890 void ShenandoahBarrierSetC2::array_copy_post_barrier_at_expansion(ArrayCopyNode* ac, Node*& c, Node*& m, PhaseIterGVN& igvn) const {
891 assert(ac->is_clonebasic(), "no other kind of arraycopy here");
892 const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
893 Node* dest = ac->in(ArrayCopyNode::Dest);
894 assert(dest->is_AddP(), "bad input");
895 Node* call = new CallLeafNoFPNode(ShenandoahBarrierSetC2::shenandoah_clone_barrier_Type(),
896 CAST_FROM_FN_PTR(address, ShenandoahRuntime::shenandoah_clone_barrier),
897 "shenandoah_clone_barrier", raw_adr_type);
898 call->init_req(TypeFunc::Control, c);
899 call->init_req(TypeFunc::I_O , igvn.C->top());
900 call->init_req(TypeFunc::Memory , m);
901 call->init_req(TypeFunc::ReturnAdr, igvn.C->top());
902 call->init_req(TypeFunc::FramePtr, igvn.C->top());
903 call->init_req(TypeFunc::Parms+0, dest->in(AddPNode::Base));
904
905 call = igvn.transform(call);
906 c = new ProjNode(call,TypeFunc::Control);
907 c = igvn.transform(c);
908 m = new ProjNode(call, TypeFunc::Memory);
909 m = igvn.transform(m);
910 }
911
912
913 // Support for macro expanded GC barriers
914 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const {
915 if (node->Opcode() == Op_ShenandoahWriteBarrier) {
916 state()->add_shenandoah_barrier((ShenandoahWriteBarrierNode*) node);
917 }
918 }
919
920 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const {
921 if (node->Opcode() == Op_ShenandoahWriteBarrier) {
922 state()->remove_shenandoah_barrier((ShenandoahWriteBarrierNode*) node);
923 }
924 }
925
926 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* n) const {
927 if (is_shenandoah_wb_pre_call(n)) {
928 shenandoah_eliminate_wb_pre(n, ¯o->igvn());
929 }
930 }
931
932 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const {
933 assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), "");
934 Node* c = call->as_Call()->proj_out(TypeFunc::Control);
935 c = c->unique_ctrl_out();
936 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
937 c = c->unique_ctrl_out();
938 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
939 Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
940 assert(iff->is_If(), "expect test");
941 if (!is_shenandoah_marking_if(igvn, iff)) {
942 c = c->unique_ctrl_out();
943 assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
944 iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
945 assert(is_shenandoah_marking_if(igvn, iff), "expect marking test");
946 }
947 Node* cmpx = iff->in(1)->in(1);
948 igvn->replace_node(cmpx, igvn->makecon(TypeInt::CC_EQ));
949 igvn->rehash_node_delayed(call);
950 call->del_req(call->req()-1);
951 }
952
953 void ShenandoahBarrierSetC2::enqueue_useful_gc_barrier(PhaseIterGVN* igvn, Node* node) const {
954 if (node->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(node)) {
955 igvn->add_users_to_worklist(node);
956 }
957 }
958
959 void ShenandoahBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful, Compile* C) const {
960 for (uint i = 0; i < useful.size(); i++) {
961 Node* n = useful.at(i);
962 if (n->Opcode() == Op_AddP && ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(n)) {
963 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
964 C->record_for_igvn(n->fast_out(i));
965 }
966 }
967 }
968 for (int i = state()->shenandoah_barriers_count()-1; i >= 0; i--) {
969 ShenandoahWriteBarrierNode* n = state()->shenandoah_barrier(i);
970 if (!useful.member(n)) {
971 state()->remove_shenandoah_barrier(n);
972 }
973 }
974
975 }
976
977 void ShenandoahBarrierSetC2::add_users_to_worklist(Unique_Node_List* worklist) const {}
978
979 void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const {
980 return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena);
981 }
982
983 ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const {
984 return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state());
985 }
986
987 // If the BarrierSetC2 state has kept macro nodes in its compilation unit state to be
988 // expanded later, then now is the time to do so.
989 bool ShenandoahBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { return false; }
990 void ShenandoahBarrierSetC2::verify_gc_barriers(bool post_parse) const {
991 #ifdef ASSERT
992 if (ShenandoahVerifyOptoBarriers && !post_parse) {
993 ShenandoahBarrierNode::verify(Compile::current()->root());
994 }
995 #endif
996 }
997
998 Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN *phase, Node* n, bool can_reshape) const {
999 if (is_shenandoah_wb_pre_call(n)) {
1000 uint cnt = ShenandoahBarrierSetC2::write_ref_field_pre_entry_Type()->domain()->cnt();
1001 if (n->req() > cnt) {
1002 Node* addp = n->in(cnt);
1003 if (has_only_shenandoah_wb_pre_uses(addp)) {
1004 n->del_req(cnt);
1005 if (can_reshape) {
1006 phase->is_IterGVN()->_worklist.push(addp);
1007 }
1008 return n;
1009 }
1010 }
1011 }
1012 if (n->Opcode() == Op_CmpP) {
1013 Node* in1 = n->in(1);
1014 Node* in2 = n->in(2);
1015 if (in1->bottom_type() == TypePtr::NULL_PTR) {
1016 in2 = step_over_gc_barrier(in2);
1017 }
1018 if (in2->bottom_type() == TypePtr::NULL_PTR) {
1019 in1 = step_over_gc_barrier(in1);
1020 }
1021 PhaseIterGVN* igvn = phase->is_IterGVN();
1022 if (in1 != n->in(1)) {
1023 if (igvn != NULL) {
1024 n->set_req_X(1, in1, igvn);
1025 } else {
1026 n->set_req(1, in1);
1027 }
1028 assert(in2 == n->in(2), "only one change");
1029 return n;
1030 }
1031 if (in2 != n->in(2)) {
1032 if (igvn != NULL) {
1033 n->set_req_X(2, in2, igvn);
1034 } else {
1035 n->set_req(2, in2);
1036 }
1037 return n;
1038 }
1039 }
1040
1041 return NULL;
1042 }
1043
1044 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) {
1045 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1046 Node* u = n->fast_out(i);
1047 if (!is_shenandoah_wb_pre_call(u)) {
1048 return false;
1049 }
1050 }
1051 return n->outcnt() > 0;
1052 }