1 /*
2 * Copyright (c) 2018, 2023, Red Hat, Inc. All rights reserved.
3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "classfile/javaClasses.inline.hpp"
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shenandoah/c2/shenandoahBarrierSetC2.hpp"
29 #include "gc/shenandoah/heuristics/shenandoahHeuristics.hpp"
30 #include "gc/shenandoah/shenandoahForwarding.hpp"
31 #include "gc/shenandoah/shenandoahHeap.hpp"
32 #include "gc/shenandoah/shenandoahRuntime.hpp"
33 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
34 #include "opto/arraycopynode.hpp"
35 #include "opto/escape.hpp"
36 #include "opto/graphKit.hpp"
37 #include "opto/idealKit.hpp"
38 #include "opto/macro.hpp"
39 #include "opto/narrowptrnode.hpp"
40 #include "opto/output.hpp"
41 #include "opto/rootnode.hpp"
42 #include "opto/runtime.hpp"
43
44 ShenandoahBarrierSetC2* ShenandoahBarrierSetC2::bsc2() {
45 return reinterpret_cast<ShenandoahBarrierSetC2*>(BarrierSet::barrier_set()->barrier_set_c2());
46 }
47
48 ShenandoahBarrierSetC2State::ShenandoahBarrierSetC2State(Arena* comp_arena) :
49 BarrierSetC2State(comp_arena),
50 _stubs(new (comp_arena) GrowableArray<ShenandoahBarrierStubC2*>(comp_arena, 8, 0, nullptr)),
51 _stubs_start_offset(0) {
52 }
53
54 #define __ kit->
55
56 static bool satb_can_remove_pre_barrier(GraphKit* kit, PhaseValues* phase, Node* adr,
57 BasicType bt, uint adr_idx) {
58 intptr_t offset = 0;
59 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
60 AllocateNode* alloc = AllocateNode::Ideal_allocation(base);
61
62 if (offset == Type::OffsetBot) {
63 return false; // cannot unalias unless there are precise offsets
64 }
65
66 if (alloc == nullptr) {
67 return false; // No allocation found
68 }
69
70 intptr_t size_in_bytes = type2aelembytes(bt);
71
72 Node* mem = __ memory(adr_idx); // start searching here...
73
74 for (int cnt = 0; cnt < 50; cnt++) {
75
76 if (mem->is_Store()) {
77
78 Node* st_adr = mem->in(MemNode::Address);
79 intptr_t st_offset = 0;
80 Node* st_base = AddPNode::Ideal_base_and_offset(st_adr, phase, st_offset);
81
82 if (st_base == nullptr) {
83 break; // inscrutable pointer
84 }
85
86 // Break we have found a store with same base and offset as ours so break
87 if (st_base == base && st_offset == offset) {
88 break;
89 }
90
91 if (st_offset != offset && st_offset != Type::OffsetBot) {
92 const int MAX_STORE = BytesPerLong;
93 if (st_offset >= offset + size_in_bytes ||
94 st_offset <= offset - MAX_STORE ||
95 st_offset <= offset - mem->as_Store()->memory_size()) {
96 // Success: The offsets are provably independent.
97 // (You may ask, why not just test st_offset != offset and be done?
98 // The answer is that stores of different sizes can co-exist
99 // in the same sequence of RawMem effects. We sometimes initialize
100 // a whole 'tile' of array elements with a single jint or jlong.)
101 mem = mem->in(MemNode::Memory);
102 continue; // advance through independent store memory
103 }
104 }
105
106 if (st_base != base
107 && MemNode::detect_ptr_independence(base, alloc, st_base,
108 AllocateNode::Ideal_allocation(st_base),
109 phase)) {
110 // Success: The bases are provably independent.
111 mem = mem->in(MemNode::Memory);
112 continue; // advance through independent store memory
113 }
114 } else if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
115
116 InitializeNode* st_init = mem->in(0)->as_Initialize();
117 AllocateNode* st_alloc = st_init->allocation();
118
119 // Make sure that we are looking at the same allocation site.
120 // The alloc variable is guaranteed to not be null here from earlier check.
121 if (alloc == st_alloc) {
122 // Check that the initialization is storing null so that no previous store
123 // has been moved up and directly write a reference
124 Node* captured_store = st_init->find_captured_store(offset,
125 type2aelembytes(T_OBJECT),
126 phase);
127 if (captured_store == nullptr || captured_store == st_init->zero_memory()) {
128 return true;
129 }
130 }
131 }
132
133 // Unless there is an explicit 'continue', we must bail out here,
134 // because 'mem' is an inscrutable memory state (e.g., a call).
135 break;
136 }
137
138 return false;
139 }
140
141 static bool shenandoah_can_remove_post_barrier(GraphKit* kit, PhaseValues* phase, Node* store_ctrl, Node* adr) {
142 intptr_t offset = 0;
143 Node* base = AddPNode::Ideal_base_and_offset(adr, phase, offset);
144 AllocateNode* alloc = AllocateNode::Ideal_allocation(base);
145
146 if (offset == Type::OffsetBot) {
147 return false; // Cannot unalias unless there are precise offsets.
148 }
149 if (alloc == nullptr) {
150 return false; // No allocation found.
151 }
152
153 Node* mem = store_ctrl; // Start search from Store node.
154 if (mem->is_Proj() && mem->in(0)->is_Initialize()) {
155 InitializeNode* st_init = mem->in(0)->as_Initialize();
156 AllocateNode* st_alloc = st_init->allocation();
157 // Make sure we are looking at the same allocation
158 if (alloc == st_alloc) {
159 return true;
160 }
161 }
162
163 return false;
164 }
165
166 static uint8_t get_store_barrier(C2Access& access) {
167 if (!access.is_parse_access()) {
168 // Only support for eliding barriers at parse time for now.
169 return (ShenandoahSATBBarrier ? ShenandoahBarrierSATB : 0) | (ShenandoahCardBarrier ? ShenandoahBarrierCardMark : 0);
170 }
171 GraphKit* kit = (static_cast<C2ParseAccess&>(access)).kit();
172 Node* ctl = kit->control();
173 Node* adr = access.addr().node();
174 uint adr_idx = kit->C->get_alias_index(access.addr().type());
175 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory");
176
177 bool can_remove_pre_barrier = satb_can_remove_pre_barrier(kit, &kit->gvn(), adr, access.type(), adr_idx);
178
179 // We can skip marks on a freshly-allocated object in Eden. Keep this code in
180 // sync with CardTableBarrierSet::on_slowpath_allocation_exit. That routine
181 // informs GC to take appropriate compensating steps, upon a slow-path
182 // allocation, so as to make this card-mark elision safe.
183 // The post-barrier can also be removed if null is written. This case is
184 // handled by ShenandoahBarrierSetC2::expand_barriers, which runs at the end of C2's
185 // platform-independent optimizations to exploit stronger type information.
186 bool can_remove_post_barrier = ReduceInitialCardMarks &&
187 ((access.base() == kit->just_allocated_object(ctl)) ||
188 shenandoah_can_remove_post_barrier(kit, &kit->gvn(), ctl, adr));
189
190 int barriers = 0;
191 if (!can_remove_pre_barrier) {
192 barriers |= (ShenandoahSATBBarrier ? ShenandoahBarrierSATB : 0);
193 } else {
194 barriers |= ShenandoahBarrierElided;
195 }
196
197 if (!can_remove_post_barrier) {
198 barriers |= (ShenandoahCardBarrier ? ShenandoahBarrierCardMark : 0);
199 } else {
200 barriers |= ShenandoahBarrierElided;
201 }
202
203 return barriers;
204 }
205
206 Node* ShenandoahBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const {
207 DecoratorSet decorators = access.decorators();
208 bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
209 bool in_heap = (decorators & IN_HEAP) != 0;
210 bool tightly_coupled_alloc = (decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0;
211 bool needs_pre_barrier = access.is_oop() && (in_heap || anonymous);
212 // Pre-barriers are unnecessary for tightly-coupled initialization stores.
213 bool can_be_elided = needs_pre_barrier && tightly_coupled_alloc && ReduceInitialCardMarks;
214 bool no_keepalive = (decorators & AS_NO_KEEPALIVE) != 0;
215 if (needs_pre_barrier) {
216 if (can_be_elided) {
217 access.set_barrier_data(access.barrier_data() & ~ShenandoahBarrierSATB);
218 access.set_barrier_data(access.barrier_data() | ShenandoahBarrierElided);
219 } else {
220 access.set_barrier_data(get_store_barrier(access));
221 }
222 }
223 if (no_keepalive) {
224 // No keep-alive means no need for the pre-barrier.
225 access.set_barrier_data(access.barrier_data() & ~ShenandoahBarrierSATB);
226 }
227 return BarrierSetC2::store_at_resolved(access, val);
228 }
229
230 static void set_barrier_data(C2Access& access, bool rmw) {
231 if (!access.is_oop()) {
232 return;
233 }
234
235 if (access.decorators() & C2_TIGHTLY_COUPLED_ALLOC) {
236 access.set_barrier_data(ShenandoahBarrierElided);
237 return;
238 }
239
240 uint8_t barrier_data = 0;
241
242 if (ShenandoahLoadRefBarrier) {
243 if (access.decorators() & ON_PHANTOM_OOP_REF) {
244 barrier_data |= ShenandoahBarrierPhantom;
245 } else if (access.decorators() & ON_WEAK_OOP_REF) {
246 barrier_data |= ShenandoahBarrierWeak;
247 } else {
248 barrier_data |= ShenandoahBarrierStrong;
249 }
250 }
251
252 if (rmw) {
253 if (ShenandoahSATBBarrier) {
254 barrier_data |= ShenandoahBarrierSATB;
255 }
256 if (ShenandoahCardBarrier) {
257 barrier_data |= ShenandoahCardBarrier;
258 }
259 }
260
261 if (access.decorators() & IN_NATIVE) {
262 barrier_data |= ShenandoahBarrierNative;
263 }
264
265 access.set_barrier_data(barrier_data);
266 }
267
268 Node* ShenandoahBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
269 // 1: non-reference load, no additional barrier is needed
270 if (!access.is_oop()) {
271 return BarrierSetC2::load_at_resolved(access, val_type);
272 }
273
274 // 2. Set barrier data for LRB.
275 set_barrier_data(access, /* rmw = */ false);
276
277 // 3. If we are reading the value of the referent field of a Reference object, we
278 // need to record the referent in an SATB log buffer using the pre-barrier
279 // mechanism.
280 DecoratorSet decorators = access.decorators();
281 bool on_weak = (decorators & ON_WEAK_OOP_REF) != 0;
282 bool on_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
283 bool no_keepalive = (decorators & AS_NO_KEEPALIVE) != 0;
284 bool needs_read_barrier = ((on_weak || on_phantom) && !no_keepalive);
285 if (needs_read_barrier) {
286 uint8_t barriers = access.barrier_data() | (ShenandoahSATBBarrier ? ShenandoahBarrierSATB : 0);
287 access.set_barrier_data(barriers);
288 }
289
290 return BarrierSetC2::load_at_resolved(access, val_type);
291 }
292
293 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
294 Node* new_val, const Type* value_type) const {
295 set_barrier_data(access, /* rmw = */ true);
296 return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);
297 }
298
299 Node* ShenandoahBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
300 Node* new_val, const Type* value_type) const {
301 set_barrier_data(access, /* rmw = */ true);
302 return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
303 }
304
305 Node* ShenandoahBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* val, const Type* value_type) const {
306 set_barrier_data(access, /* rmw = */ true);
307 return BarrierSetC2::atomic_xchg_at_resolved(access, val, value_type);
308 }
309
310 void ShenandoahBarrierSetC2::refine_store(const Node* n) {
311 MemNode* store = n->as_Store();
312 const Node* newval = n->in(MemNode::ValueIn);
313 assert(newval != nullptr, "");
314 const Type* newval_bottom = newval->bottom_type();
315 TypePtr::PTR newval_type = newval_bottom->make_ptr()->ptr();
316 uint8_t barrier_data = store->barrier_data();
317 if (!newval_bottom->isa_oopptr() &&
318 !newval_bottom->isa_narrowoop() &&
319 newval_type != TypePtr::Null) {
320 // newval is neither an OOP nor null, so there is no barrier to refine.
321 assert(barrier_data == 0, "non-OOP stores should have no barrier data");
322 return;
323 }
324 if (barrier_data == 0) {
325 // No barrier to refine.
326 return;
327 }
328 if (newval_type == TypePtr::Null) {
329 barrier_data &= ~ShenandoahBarrierNotNull;
330 // Simply elide post-barrier if writing null.
331 barrier_data &= ~ShenandoahBarrierCardMark;
332 } else if (newval_type == TypePtr::NotNull) {
333 barrier_data |= ShenandoahBarrierNotNull;
334 }
335 store->set_barrier_data(barrier_data);
336 }
337
338 void ShenandoahBarrierSetC2::final_refinement(Compile* C) const {
339 ResourceMark rm;
340 VectorSet visited;
341 Node_List worklist;
342 worklist.push(C->root());
343 while (worklist.size() > 0) {
344 Node* n = worklist.pop();
345 if (visited.test_set(n->_idx)) {
346 continue;
347 }
348
349 // If there are no real barrier flags on the node, strip away additional fluff.
350 // Matcher does not care about this, and we would like to avoid invoking "barrier_data() != 0"
351 // rules when the only flags are the irrelevant fluff.
352 if (n->is_LoadStore()) {
353 LoadStoreNode* load_store = n->as_LoadStore();
354 uint8_t barrier_data = load_store->barrier_data();
355 if ((barrier_data & ShenandoahBarriersReal) == 0) {
356 load_store->set_barrier_data(0);
357 }
358 } else if (n->is_Mem()) {
359 MemNode* mem = n->as_Mem();
360 uint8_t barrier_data = mem->barrier_data();
361 if ((barrier_data & ShenandoahBarriersReal) == 0) {
362 mem->set_barrier_data(0);
363 }
364 }
365
366 for (uint j = 0; j < n->req(); j++) {
367 Node* in = n->in(j);
368 if (in != nullptr) {
369 worklist.push(in);
370 }
371 }
372 }
373 }
374
375 bool ShenandoahBarrierSetC2::expand_barriers(Compile* C, PhaseIterGVN& igvn) const {
376 ResourceMark rm;
377 VectorSet visited;
378 Node_List worklist;
379 worklist.push(C->root());
380 while (worklist.size() > 0) {
381 Node* n = worklist.pop();
382 if (visited.test_set(n->_idx)) {
383 continue;
384 }
385 switch(n->Opcode()) {
386 case Op_StoreP:
387 case Op_StoreN: {
388 refine_store(n);
389 break;
390 }
391 }
392
393 for (uint j = 0; j < n->req(); j++) {
394 Node* in = n->in(j);
395 if (in != nullptr) {
396 worklist.push(in);
397 }
398 }
399 }
400 return false;
401 }
402
403 bool ShenandoahBarrierSetC2::array_copy_requires_gc_barriers(bool tightly_coupled_alloc, BasicType type, bool is_clone, bool is_clone_instance, ArrayCopyPhase phase) const {
404 bool is_oop = is_reference_type(type);
405 if (!is_oop) {
406 return false;
407 }
408 if (ShenandoahSATBBarrier && tightly_coupled_alloc) {
409 if (phase == Optimization) {
410 return false;
411 }
412 return !is_clone;
413 }
414 return true;
415 }
416
417 bool ShenandoahBarrierSetC2::clone_needs_barrier(const TypeOopPtr* src_type, bool& is_oop_array) {
418 if (!ShenandoahCloneBarrier) {
419 return false;
420 }
421
422 if (src_type->isa_instptr() != nullptr) {
423 // Instance: need barrier only if there is a possibility of having an oop anywhere in it.
424 ciInstanceKlass* ik = src_type->is_instptr()->instance_klass();
425 if ((src_type->klass_is_exact() || !ik->has_subklass()) &&
426 !ik->has_injected_fields() && !ik->has_object_fields()) {
427 if (!src_type->klass_is_exact()) {
428 // Class is *currently* the leaf in the hierarchy.
429 // Record the dependency so that we deopt if this does not hold in future.
430 Compile::current()->dependencies()->assert_leaf_type(ik);
431 }
432 return false;
433 }
434 } else if (src_type->isa_aryptr() != nullptr) {
435 // Array: need barrier only if array is oop-bearing.
436 BasicType src_elem = src_type->isa_aryptr()->elem()->array_element_basic_type();
437 if (is_reference_type(src_elem, true)) {
438 is_oop_array = true;
439 } else {
440 return false;
441 }
442 }
443
444 // Assume the worst.
445 return true;
446 }
447
448 void ShenandoahBarrierSetC2::clone(GraphKit* kit, Node* src_base, Node* dst_base, Node* size, bool is_array) const {
449 const TypeOopPtr* src_type = kit->gvn().type(src_base)->is_oopptr();
450
451 bool is_oop_array = false;
452 if (!clone_needs_barrier(src_type, is_oop_array)) {
453 // No barrier is needed? Just do what common BarrierSetC2 wants with it.
454 BarrierSetC2::clone(kit, src_base, dst_base, size, is_array);
455 return;
456 }
457
458 if (ShenandoahCloneRuntime || !is_array || !is_oop_array) {
459 // Looks like an instance? Prepare the instance clone. This would either
460 // be exploded into individual accesses or be left as runtime call.
461 // Common BarrierSetC2 prepares everything for both cases.
462 BarrierSetC2::clone(kit, src_base, dst_base, size, is_array);
463 return;
464 }
465
466 // We are cloning the oop array. Prepare to call the normal arraycopy stub
467 // after the expansion. Normal stub takes the number of actual type-sized
468 // elements to copy after the base, compute the count here.
469 Node* offset = kit->MakeConX(arrayOopDesc::base_offset_in_bytes(UseCompressedOops ? T_NARROWOOP : T_OBJECT));
470 size = kit->gvn().transform(new SubXNode(size, offset));
471 size = kit->gvn().transform(new URShiftXNode(size, kit->intcon(LogBytesPerHeapOop)));
472 ArrayCopyNode* ac = ArrayCopyNode::make(kit, false, src_base, offset, dst_base, offset, size, true, false);
473 ac->set_clone_array();
474 Node* n = kit->gvn().transform(ac);
475 if (n == ac) {
476 ac->set_adr_type(TypeRawPtr::BOTTOM);
477 kit->set_predefined_output_for_runtime_call(ac, ac->in(TypeFunc::Memory), TypeRawPtr::BOTTOM);
478 } else {
479 kit->set_all_memory(n);
480 }
481 }
482
483 void ShenandoahBarrierSetC2::clone_at_expansion(PhaseMacroExpand* phase, ArrayCopyNode* ac) const {
484 Node* const ctrl = ac->in(TypeFunc::Control);
485 Node* const mem = ac->in(TypeFunc::Memory);
486 Node* const src = ac->in(ArrayCopyNode::Src);
487 Node* const src_offset = ac->in(ArrayCopyNode::SrcPos);
488 Node* const dest = ac->in(ArrayCopyNode::Dest);
489 Node* const dest_offset = ac->in(ArrayCopyNode::DestPos);
490 Node* length = ac->in(ArrayCopyNode::Length);
491
492 const TypeOopPtr* src_type = phase->igvn().type(src)->is_oopptr();
493
494 bool is_oop_array = false;
495 if (!clone_needs_barrier(src_type, is_oop_array)) {
496 // No barrier is needed? Expand to normal HeapWord-sized arraycopy.
497 BarrierSetC2::clone_at_expansion(phase, ac);
498 return;
499 }
500
501 if (ShenandoahCloneRuntime || !ac->is_clone_array() || !is_oop_array) {
502 // Still looks like an instance? Likely a large instance or reflective
503 // clone with unknown length. Go to runtime and handle it there.
504 clone_in_runtime(phase, ac, CAST_FROM_FN_PTR(address, ShenandoahRuntime::clone_addr()), "ShenandoahRuntime::clone");
505 return;
506 }
507
508 // We are cloning the oop array. Call into normal oop array copy stubs.
509 // Those stubs would call BarrierSetAssembler to handle GC barriers.
510
511 // This is the full clone, so offsets should equal each other and be at array base.
512 assert(src_offset == dest_offset, "should be equal");
513 const jlong offset = src_offset->get_long();
514 const TypeAryPtr* const ary_ptr = src->get_ptr_type()->isa_aryptr();
515 BasicType bt = ary_ptr->elem()->array_element_basic_type();
516 assert(offset == arrayOopDesc::base_offset_in_bytes(bt), "should match");
517
518 const char* copyfunc_name = "arraycopy";
519 const address copyfunc_addr = phase->basictype2arraycopy(T_OBJECT, nullptr, nullptr, true, copyfunc_name, true);
520
521 Node* const call = phase->make_leaf_call(ctrl, mem,
522 OptoRuntime::fast_arraycopy_Type(),
523 copyfunc_addr, copyfunc_name,
524 TypeRawPtr::BOTTOM,
525 phase->basic_plus_adr(src, src_offset),
526 phase->basic_plus_adr(dest, dest_offset),
527 length,
528 phase->top()
529 );
530 phase->transform_later(call);
531
532 phase->igvn().replace_node(ac, call);
533 }
534
535 // Support for macro expanded GC barriers
536 void ShenandoahBarrierSetC2::eliminate_gc_barrier_data(Node* node) const {
537 if (node->is_LoadStore()) {
538 LoadStoreNode* loadstore = node->as_LoadStore();
539 loadstore->set_barrier_data(0);
540 } else if (node->is_Mem()) {
541 MemNode* mem = node->as_Mem();
542 mem->set_barrier_data(0);
543 }
544 }
545
546 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const {
547 eliminate_gc_barrier_data(node);
548 }
549
550 void* ShenandoahBarrierSetC2::create_barrier_state(Arena* comp_arena) const {
551 return new(comp_arena) ShenandoahBarrierSetC2State(comp_arena);
552 }
553
554 ShenandoahBarrierSetC2State* ShenandoahBarrierSetC2::state() const {
555 return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state());
556 }
557
558 void ShenandoahBarrierSetC2::print_barrier_data(outputStream* os, uint8_t data) {
559 os->print(" Node barriers: ");
560 if ((data & ShenandoahBarrierStrong) != 0) {
561 data &= ~ShenandoahBarrierStrong;
562 os->print("strong ");
563 }
564
565 if ((data & ShenandoahBarrierWeak) != 0) {
566 data &= ~ShenandoahBarrierWeak;
567 os->print("weak ");
568 }
569
570 if ((data & ShenandoahBarrierPhantom) != 0) {
571 data &= ~ShenandoahBarrierPhantom;
572 os->print("phantom ");
573 }
574
575 if ((data & ShenandoahBarrierNative) != 0) {
576 data &= ~ShenandoahBarrierNative;
577 os->print("native ");
578 }
579
580 if ((data & ShenandoahBarrierElided) != 0) {
581 data &= ~ShenandoahBarrierElided;
582 os->print("elided ");
583 }
584
585 if ((data & ShenandoahBarrierSATB) != 0) {
586 data &= ~ShenandoahBarrierSATB;
587 os->print("satb ");
588 }
589
590 if ((data & ShenandoahBarrierCardMark) != 0) {
591 data &= ~ShenandoahBarrierCardMark;
592 os->print("cardmark ");
593 }
594
595 if ((data & ShenandoahBarrierNotNull) != 0) {
596 data &= ~ShenandoahBarrierNotNull;
597 os->print("not-null ");
598 }
599 os->cr();
600
601 if (data > 0) {
602 fatal("Unknown bit!");
603 }
604
605 os->print_cr(" GC configuration: %sLRB %sSATB %sCAS %sClone %sCard",
606 (ShenandoahLoadRefBarrier ? "+" : "-"),
607 (ShenandoahSATBBarrier ? "+" : "-"),
608 (ShenandoahCASBarrier ? "+" : "-"),
609 (ShenandoahCloneBarrier ? "+" : "-"),
610 (ShenandoahCardBarrier ? "+" : "-")
611 );
612 }
613
614 #ifdef ASSERT
615 void ShenandoahBarrierSetC2::verify_gc_barrier_assert(bool cond, const char* msg, uint8_t bd, Node* n) {
616 if (!cond) {
617 stringStream ss;
618 ss.print_cr("%s", msg);
619 ss.print_cr("-----------------");
620 print_barrier_data(&ss, bd);
621 ss.print_cr("-----------------");
622 n->dump_bfs(1, nullptr, "", &ss);
623 report_vm_error(__FILE__, __LINE__, ss.as_string());
624 }
625 }
626
627 void ShenandoahBarrierSetC2::verify_gc_barriers(Compile* compile, CompilePhase phase) const {
628 if (!ShenandoahVerifyOptoBarriers) {
629 return;
630 }
631
632 // Final refinement might have removed the remaining auxiliary flags, making some accesses completely blank.
633 bool accept_blank = (phase == BeforeCodeGen);
634 bool expect_load_barriers = !accept_blank && ShenandoahLoadRefBarrier;
635 bool expect_store_barriers = !accept_blank && (ShenandoahSATBBarrier || ShenandoahCardBarrier);
636 bool expect_load_store_barriers = !accept_blank && ShenandoahCASBarrier;
637
638 Unique_Node_List wq;
639 Node_Stack phis(0);
640 VectorSet visited;
641
642 wq.push(compile->root());
643 for (uint next = 0; next < wq.size(); next++) {
644 Node *n = wq.at(next);
645 int opc = n->Opcode();
646
647 if (opc == Op_LoadP || opc == Op_LoadN) {
648 uint8_t bd = n->as_Load()->barrier_data();
649
650 const TypePtr* adr_type = n->as_Load()->adr_type();
651 if (adr_type->isa_oopptr() || adr_type->isa_narrowoop()) {
652 verify_gc_barrier_assert(!expect_load_barriers || (bd != 0), "Oop load should have barrier data", bd, n);
653
654 bool is_weak = ((bd & (ShenandoahBarrierWeak | ShenandoahBarrierPhantom)) != 0);
655 bool is_referent = adr_type->isa_instptr() &&
656 adr_type->is_instptr()->instance_klass()->is_subtype_of(Compile::current()->env()->Reference_klass()) &&
657 adr_type->is_instptr()->offset() == java_lang_ref_Reference::referent_offset();
658
659 verify_gc_barrier_assert(!is_weak || is_referent, "Weak load only for Reference.referent", bd, n);
660 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
661 // Some LoadP-s are used for T_ADDRESS loads from raw pointers. These are not oops.
662 // Some LoadP-s are used to load class data.
663 // TODO: Verify their barrier data.
664 } else {
665 verify_gc_barrier_assert(false, "Unclassified access type", bd, n);
666 }
667 } else if (opc == Op_StoreP || opc == Op_StoreN) {
668 uint8_t bd = n->as_Store()->barrier_data();
669 const TypePtr* adr_type = n->as_Store()->adr_type();
670 if (adr_type->isa_oopptr() || adr_type->isa_narrowoop()) {
671 // Reference.clear stores null
672 bool is_referent = adr_type->isa_instptr() &&
673 adr_type->is_instptr()->instance_klass()->is_subtype_of(Compile::current()->env()->Reference_klass()) &&
674 adr_type->is_instptr()->offset() == java_lang_ref_Reference::referent_offset();
675
676 const TypePtr* val_type = n->as_Store()->in(MemNode::Memory)->adr_type();
677 if (!is_referent && (val_type->isa_oopptr() || val_type->isa_narrowoop())) {
678 verify_gc_barrier_assert(!expect_store_barriers || (bd != 0), "Oop store should have barrier data", bd, n);
679 }
680 } else if (adr_type->isa_rawptr() || adr_type->isa_klassptr()) {
681 // Similar to LoadP-s, some of these accesses are raw, and some are handling oops.
682 // TODO: Verify their barrier data.
683 } else {
684 verify_gc_barrier_assert(false, "Unclassified access type", bd, n);
685 }
686 } else if (opc == Op_WeakCompareAndSwapP || opc == Op_WeakCompareAndSwapN ||
687 opc == Op_CompareAndExchangeP || opc == Op_CompareAndExchangeN ||
688 opc == Op_CompareAndSwapP || opc == Op_CompareAndSwapN ||
689 opc == Op_GetAndSetP || opc == Op_GetAndSetN) {
690 uint8_t bd = n->as_LoadStore()->barrier_data();
691 verify_gc_barrier_assert(!expect_load_store_barriers || (bd != 0), "Oop load-store should have barrier data", bd, n);
692 } else if (n->is_Mem()) {
693 uint8_t bd = MemNode::barrier_data(n); // FIXME: LOL HotSpot, why not n->as_Mem()? LoadStore is both is_Mem() and not as_Mem().
694 verify_gc_barrier_assert(bd == 0, "Other mem nodes should have no barrier data", bd, n);
695 }
696
697 for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
698 Node* m = n->fast_out(i);
699 wq.push(m);
700 }
701 }
702 }
703 #endif
704
705 static ShenandoahBarrierSetC2State* barrier_set_state() {
706 return reinterpret_cast<ShenandoahBarrierSetC2State*>(Compile::current()->barrier_set_state());
707 }
708
709 int ShenandoahBarrierSetC2::estimate_stub_size() const {
710 Compile* const C = Compile::current();
711 BufferBlob* const blob = C->output()->scratch_buffer_blob();
712 GrowableArray<ShenandoahBarrierStubC2*>* const stubs = barrier_set_state()->stubs();
713 int size = 0;
714
715 for (int i = 0; i < stubs->length(); i++) {
716 CodeBuffer cb(blob->content_begin(), checked_cast<CodeBuffer::csize_t>((address)C->output()->scratch_locs_memory() - blob->content_begin()));
717 MacroAssembler masm(&cb);
718 stubs->at(i)->emit_code(masm);
719 size += cb.insts_size();
720 }
721
722 return size;
723 }
724
725 void ShenandoahBarrierSetC2::emit_stubs(CodeBuffer& cb) const {
726 MacroAssembler masm(&cb);
727 GrowableArray<ShenandoahBarrierStubC2*>* const stubs = barrier_set_state()->stubs();
728 barrier_set_state()->set_stubs_start_offset(masm.offset());
729
730 for (int i = 0; i < stubs->length(); i++) {
731 // Make sure there is enough space in the code buffer
732 if (cb.insts()->maybe_expand_to_ensure_remaining(PhaseOutput::MAX_inst_size) && cb.blob() == nullptr) {
733 ciEnv::current()->record_failure("CodeCache is full");
734 return;
735 }
736
737 stubs->at(i)->emit_code(masm);
738 }
739
740 masm.flush();
741
742 }
743
744 void ShenandoahBarrierStubC2::register_stub() {
745 if (!Compile::current()->output()->in_scratch_emit_size()) {
746 barrier_set_state()->stubs()->append(this);
747 }
748 }
749
750 ShenandoahLoadBarrierStubC2* ShenandoahLoadBarrierStubC2::create(const MachNode* node, Register dst, Address src, bool narrow, Register tmp) {
751 auto* stub = new (Compile::current()->comp_arena()) ShenandoahLoadBarrierStubC2(node, dst, src, narrow, tmp);
752 stub->register_stub();
753 return stub;
754 }
755
756 ShenandoahStoreBarrierStubC2* ShenandoahStoreBarrierStubC2::create(const MachNode* node, Address dst, bool dst_narrow, Register src, bool src_narrow, Register tmp) {
757 auto* stub = new (Compile::current()->comp_arena()) ShenandoahStoreBarrierStubC2(node, dst, dst_narrow, src, src_narrow, tmp);
758 stub->register_stub();
759 return stub;
760 }
761
762 ShenandoahLoadRefBarrierStubC2* ShenandoahLoadRefBarrierStubC2::create(const MachNode* node, Register obj, Register addr, Register tmp1, Register tmp2, Register tmp3, bool narrow) {
763 auto* stub = new (Compile::current()->comp_arena()) ShenandoahLoadRefBarrierStubC2(node, obj, addr, tmp1, tmp2, tmp3, narrow);
764 stub->register_stub();
765 return stub;
766 }
767
768 ShenandoahSATBBarrierStubC2* ShenandoahSATBBarrierStubC2::create(const MachNode* node, Register addr, Register preval, Register tmp, bool encoded_preval) {
769 auto* stub = new (Compile::current()->comp_arena()) ShenandoahSATBBarrierStubC2(node, addr, preval, tmp, encoded_preval);
770 stub->register_stub();
771 return stub;
772 }
773
774 ShenandoahCASBarrierSlowStubC2* ShenandoahCASBarrierSlowStubC2::create(const MachNode* node, Register addr, Register expected, Register new_val, Register result, Register tmp1, Register tmp2, bool cae, bool acquire, bool release, bool weak) {
775 auto* stub = new (Compile::current()->comp_arena()) ShenandoahCASBarrierSlowStubC2(node, addr, Address(), expected, new_val, result, tmp1, tmp2, cae, acquire, release, weak);
776 stub->register_stub();
777 return stub;
778 }
779
780 ShenandoahCASBarrierSlowStubC2* ShenandoahCASBarrierSlowStubC2::create(const MachNode* node, Address addr, Register expected, Register new_val, Register result, Register tmp1, Register tmp2, bool cae) {
781 auto* stub = new (Compile::current()->comp_arena()) ShenandoahCASBarrierSlowStubC2(node, noreg, addr, expected, new_val, result, tmp1, tmp2, cae, false, false, false);
782 stub->register_stub();
783 return stub;
784 }
785
786 bool ShenandoahBarrierSetC2State::needs_liveness_data(const MachNode* mach) const {
787 return ShenandoahSATBBarrierStubC2::needs_barrier(mach) ||
788 ShenandoahLoadRefBarrierStubC2::needs_barrier(mach);
789 }
790
791 bool ShenandoahBarrierSetC2State::needs_livein_data() const {
792 return true;
793 }