1 /*
2 * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "code/vmreg.inline.hpp"
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shared/tlab_globals.hpp"
29 #include "gc/shared/c2/barrierSetC2.hpp"
30 #include "opto/arraycopynode.hpp"
31 #include "opto/block.hpp"
32 #include "opto/convertnode.hpp"
33 #include "opto/graphKit.hpp"
34 #include "opto/idealKit.hpp"
35 #include "opto/macro.hpp"
36 #include "opto/narrowptrnode.hpp"
37 #include "opto/output.hpp"
38 #include "opto/regalloc.hpp"
39 #include "opto/runtime.hpp"
40 #include "utilities/macros.hpp"
41 #include CPU_HEADER(gc/shared/barrierSetAssembler)
42
43 // By default this is a no-op.
44 void BarrierSetC2::resolve_address(C2Access& access) const { }
45
46 void* C2ParseAccess::barrier_set_state() const {
47 return _kit->barrier_set_state();
48 }
49
50 PhaseGVN& C2ParseAccess::gvn() const { return _kit->gvn(); }
51
52 Node* C2ParseAccess::control() const {
53 return _ctl == nullptr ? _kit->control() : _ctl;
54 }
55
56 bool C2Access::needs_cpu_membar() const {
57 bool mismatched = (_decorators & C2_MISMATCHED) != 0;
58 bool is_unordered = (_decorators & MO_UNORDERED) != 0;
59
60 bool anonymous = (_decorators & C2_UNSAFE_ACCESS) != 0;
61 bool in_heap = (_decorators & IN_HEAP) != 0;
62 bool in_native = (_decorators & IN_NATIVE) != 0;
63 bool is_mixed = !in_heap && !in_native;
64
65 bool is_write = (_decorators & C2_WRITE_ACCESS) != 0;
66 bool is_read = (_decorators & C2_READ_ACCESS) != 0;
67 bool is_atomic = is_read && is_write;
68
69 if (is_atomic) {
70 // Atomics always need to be wrapped in CPU membars
71 return true;
72 }
73
74 if (anonymous) {
75 // We will need memory barriers unless we can determine a unique
76 // alias category for this reference. (Note: If for some reason
77 // the barriers get omitted and the unsafe reference begins to "pollute"
78 // the alias analysis of the rest of the graph, either Compile::can_alias
79 // or Compile::must_alias will throw a diagnostic assert.)
80 if (is_mixed || !is_unordered || (mismatched && !_addr.type()->isa_aryptr())) {
81 return true;
82 }
83 } else {
84 assert(!is_mixed, "not unsafe");
85 }
86
87 return false;
88 }
89
90 static BarrierSetC2State* barrier_set_state() {
91 return reinterpret_cast<BarrierSetC2State*>(Compile::current()->barrier_set_state());
92 }
93
94 RegMask& BarrierStubC2::live() const {
95 return *barrier_set_state()->live(_node);
96 }
97
98 BarrierStubC2::BarrierStubC2(const MachNode* node)
99 : _node(node),
100 _entry(),
101 _continuation(),
102 _preserve(live()) {}
103
104 Label* BarrierStubC2::entry() {
105 // The _entry will never be bound when in_scratch_emit_size() is true.
106 // However, we still need to return a label that is not bound now, but
107 // will eventually be bound. Any eventually bound label will do, as it
108 // will only act as a placeholder, so we return the _continuation label.
109 return Compile::current()->output()->in_scratch_emit_size() ? &_continuation : &_entry;
110 }
111
112 Label* BarrierStubC2::continuation() {
113 return &_continuation;
114 }
115
116 void BarrierStubC2::preserve(Register r) {
117 const VMReg vm_reg = r->as_VMReg();
118 assert(vm_reg->is_Register(), "r must be a general-purpose register");
119 _preserve.Insert(OptoReg::as_OptoReg(vm_reg));
120 }
121
122 void BarrierStubC2::dont_preserve(Register r) {
123 VMReg vm_reg = r->as_VMReg();
124 assert(vm_reg->is_Register(), "r must be a general-purpose register");
125 // Subtract the given register and all its sub-registers (e.g. {R11, R11_H}
126 // for r11 in aarch64).
127 do {
128 _preserve.Remove(OptoReg::as_OptoReg(vm_reg));
129 vm_reg = vm_reg->next();
130 } while (vm_reg->is_Register() && !vm_reg->is_concrete());
131 }
132
133 const RegMask& BarrierStubC2::preserve_set() const {
134 return _preserve;
135 }
136
137 Node* BarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const {
138 DecoratorSet decorators = access.decorators();
139
140 bool mismatched = (decorators & C2_MISMATCHED) != 0;
141 bool unaligned = (decorators & C2_UNALIGNED) != 0;
142 bool unsafe = (decorators & C2_UNSAFE_ACCESS) != 0;
143 bool requires_atomic_access = (decorators & MO_UNORDERED) == 0;
144
145 MemNode::MemOrd mo = access.mem_node_mo();
146
147 Node* store;
148 BasicType bt = access.type();
149 if (access.is_parse_access()) {
150 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
151
152 GraphKit* kit = parse_access.kit();
153 if (bt == T_DOUBLE) {
154 Node* new_val = kit->dprecision_rounding(val.node());
155 val.set_node(new_val);
156 }
157
158 store = kit->store_to_memory(kit->control(), access.addr().node(), val.node(), bt,
159 access.addr().type(), mo, requires_atomic_access, unaligned,
160 mismatched, unsafe, access.barrier_data());
161 } else {
162 assert(access.is_opt_access(), "either parse or opt access");
163 C2OptAccess& opt_access = static_cast<C2OptAccess&>(access);
164 Node* ctl = opt_access.ctl();
165 MergeMemNode* mm = opt_access.mem();
166 PhaseGVN& gvn = opt_access.gvn();
167 const TypePtr* adr_type = access.addr().type();
168 int alias = gvn.C->get_alias_index(adr_type);
169 Node* mem = mm->memory_at(alias);
170
171 StoreNode* st = StoreNode::make(gvn, ctl, mem, access.addr().node(), adr_type, val.node(), bt, mo, requires_atomic_access);
172 if (unaligned) {
173 st->set_unaligned_access();
174 }
175 if (mismatched) {
176 st->set_mismatched_access();
177 }
178 st->set_barrier_data(access.barrier_data());
179 store = gvn.transform(st);
180 if (store == st) {
181 mm->set_memory_at(alias, st);
182 }
183 }
184 access.set_raw_access(store);
185
186 return store;
187 }
188
189 Node* BarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const {
190 DecoratorSet decorators = access.decorators();
191
192 Node* adr = access.addr().node();
193 const TypePtr* adr_type = access.addr().type();
194
195 bool mismatched = (decorators & C2_MISMATCHED) != 0;
196 bool requires_atomic_access = (decorators & MO_UNORDERED) == 0;
197 bool unaligned = (decorators & C2_UNALIGNED) != 0;
198 bool control_dependent = (decorators & C2_CONTROL_DEPENDENT_LOAD) != 0;
199 bool unknown_control = (decorators & C2_UNKNOWN_CONTROL_LOAD) != 0;
200 bool unsafe = (decorators & C2_UNSAFE_ACCESS) != 0;
201 bool immutable = (decorators & C2_IMMUTABLE_MEMORY) != 0;
202
203 MemNode::MemOrd mo = access.mem_node_mo();
204 LoadNode::ControlDependency dep = unknown_control ? LoadNode::UnknownControl : LoadNode::DependsOnlyOnTest;
205
206 Node* load;
207 if (access.is_parse_access()) {
208 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
209 GraphKit* kit = parse_access.kit();
210 Node* control = control_dependent ? parse_access.control() : nullptr;
211
212 if (immutable) {
213 Compile* C = Compile::current();
214 Node* mem = kit->immutable_memory();
215 load = LoadNode::make(kit->gvn(), control, mem, adr,
216 adr_type, val_type, access.type(), mo, dep, requires_atomic_access,
217 unaligned, mismatched, unsafe, access.barrier_data());
218 load = kit->gvn().transform(load);
219 } else {
220 load = kit->make_load(control, adr, val_type, access.type(), adr_type, mo,
221 dep, requires_atomic_access, unaligned, mismatched, unsafe,
222 access.barrier_data());
223 }
224 } else {
225 assert(access.is_opt_access(), "either parse or opt access");
226 C2OptAccess& opt_access = static_cast<C2OptAccess&>(access);
227 Node* control = control_dependent ? opt_access.ctl() : nullptr;
228 MergeMemNode* mm = opt_access.mem();
229 PhaseGVN& gvn = opt_access.gvn();
230 Node* mem = mm->memory_at(gvn.C->get_alias_index(adr_type));
231 load = LoadNode::make(gvn, control, mem, adr, adr_type, val_type, access.type(), mo, dep,
232 requires_atomic_access, unaligned, mismatched, unsafe, access.barrier_data());
233 load = gvn.transform(load);
234 }
235 access.set_raw_access(load);
236
237 return load;
238 }
239
240 class C2AccessFence: public StackObj {
241 C2Access& _access;
242 Node* _leading_membar;
243
244 public:
245 C2AccessFence(C2Access& access) :
246 _access(access), _leading_membar(nullptr) {
247 GraphKit* kit = nullptr;
248 if (access.is_parse_access()) {
249 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
250 kit = parse_access.kit();
251 }
252 DecoratorSet decorators = access.decorators();
253
254 bool is_write = (decorators & C2_WRITE_ACCESS) != 0;
255 bool is_read = (decorators & C2_READ_ACCESS) != 0;
256 bool is_atomic = is_read && is_write;
257
258 bool is_volatile = (decorators & MO_SEQ_CST) != 0;
259 bool is_release = (decorators & MO_RELEASE) != 0;
260
261 if (is_atomic) {
262 assert(kit != nullptr, "unsupported at optimization time");
263 // Memory-model-wise, a LoadStore acts like a little synchronized
264 // block, so needs barriers on each side. These don't translate
265 // into actual barriers on most machines, but we still need rest of
266 // compiler to respect ordering.
267 if (is_release) {
268 _leading_membar = kit->insert_mem_bar(Op_MemBarRelease);
269 } else if (is_volatile) {
270 if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
271 _leading_membar = kit->insert_mem_bar(Op_MemBarVolatile);
272 } else {
273 _leading_membar = kit->insert_mem_bar(Op_MemBarRelease);
274 }
275 }
276 } else if (is_write) {
277 // If reference is volatile, prevent following memory ops from
278 // floating down past the volatile write. Also prevents commoning
279 // another volatile read.
280 if (is_volatile || is_release) {
281 assert(kit != nullptr, "unsupported at optimization time");
282 _leading_membar = kit->insert_mem_bar(Op_MemBarRelease);
283 }
284 } else {
285 // Memory barrier to prevent normal and 'unsafe' accesses from
286 // bypassing each other. Happens after null checks, so the
287 // exception paths do not take memory state from the memory barrier,
288 // so there's no problems making a strong assert about mixing users
289 // of safe & unsafe memory.
290 if (is_volatile && support_IRIW_for_not_multiple_copy_atomic_cpu) {
291 assert(kit != nullptr, "unsupported at optimization time");
292 _leading_membar = kit->insert_mem_bar(Op_MemBarVolatile);
293 }
294 }
295
296 if (access.needs_cpu_membar()) {
297 assert(kit != nullptr, "unsupported at optimization time");
298 kit->insert_mem_bar(Op_MemBarCPUOrder);
299 }
300
301 if (is_atomic) {
302 // 4984716: MemBars must be inserted before this
303 // memory node in order to avoid a false
304 // dependency which will confuse the scheduler.
305 access.set_memory();
306 }
307 }
308
309 ~C2AccessFence() {
310 GraphKit* kit = nullptr;
311 if (_access.is_parse_access()) {
312 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(_access);
313 kit = parse_access.kit();
314 }
315 DecoratorSet decorators = _access.decorators();
316
317 bool is_write = (decorators & C2_WRITE_ACCESS) != 0;
318 bool is_read = (decorators & C2_READ_ACCESS) != 0;
319 bool is_atomic = is_read && is_write;
320
321 bool is_volatile = (decorators & MO_SEQ_CST) != 0;
322 bool is_acquire = (decorators & MO_ACQUIRE) != 0;
323
324 // If reference is volatile, prevent following volatiles ops from
325 // floating up before the volatile access.
326 if (_access.needs_cpu_membar()) {
327 kit->insert_mem_bar(Op_MemBarCPUOrder);
328 }
329
330 if (is_atomic) {
331 assert(kit != nullptr, "unsupported at optimization time");
332 if (is_acquire || is_volatile) {
333 Node* n = _access.raw_access();
334 Node* mb = kit->insert_mem_bar(Op_MemBarAcquire, n);
335 if (_leading_membar != nullptr) {
336 MemBarNode::set_load_store_pair(_leading_membar->as_MemBar(), mb->as_MemBar());
337 }
338 }
339 } else if (is_write) {
340 // If not multiple copy atomic, we do the MemBarVolatile before the load.
341 if (is_volatile && !support_IRIW_for_not_multiple_copy_atomic_cpu) {
342 assert(kit != nullptr, "unsupported at optimization time");
343 Node* n = _access.raw_access();
344 Node* mb = kit->insert_mem_bar(Op_MemBarVolatile, n); // Use fat membar
345 if (_leading_membar != nullptr) {
346 MemBarNode::set_store_pair(_leading_membar->as_MemBar(), mb->as_MemBar());
347 }
348 }
349 } else {
350 if (is_volatile || is_acquire) {
351 assert(kit != nullptr, "unsupported at optimization time");
352 Node* n = _access.raw_access();
353 assert(_leading_membar == nullptr || support_IRIW_for_not_multiple_copy_atomic_cpu, "no leading membar expected");
354 Node* mb = kit->insert_mem_bar(Op_MemBarAcquire, n);
355 mb->as_MemBar()->set_trailing_load();
356 }
357 }
358 }
359 };
360
361 Node* BarrierSetC2::store_at(C2Access& access, C2AccessValue& val) const {
362 C2AccessFence fence(access);
363 resolve_address(access);
364 return store_at_resolved(access, val);
365 }
366
367 Node* BarrierSetC2::load_at(C2Access& access, const Type* val_type) const {
368 C2AccessFence fence(access);
369 resolve_address(access);
370 return load_at_resolved(access, val_type);
371 }
372
373 MemNode::MemOrd C2Access::mem_node_mo() const {
374 bool is_write = (_decorators & C2_WRITE_ACCESS) != 0;
375 bool is_read = (_decorators & C2_READ_ACCESS) != 0;
376 if ((_decorators & MO_SEQ_CST) != 0) {
377 if (is_write && is_read) {
378 // For atomic operations
379 return MemNode::seqcst;
380 } else if (is_write) {
381 return MemNode::release;
382 } else {
383 assert(is_read, "what else?");
384 return MemNode::acquire;
385 }
386 } else if ((_decorators & MO_RELEASE) != 0) {
387 return MemNode::release;
388 } else if ((_decorators & MO_ACQUIRE) != 0) {
389 return MemNode::acquire;
390 } else if (is_write) {
391 // Volatile fields need releasing stores.
392 // Non-volatile fields also need releasing stores if they hold an
393 // object reference, because the object reference might point to
394 // a freshly created object.
395 // Conservatively release stores of object references.
396 return StoreNode::release_if_reference(_type);
397 } else {
398 return MemNode::unordered;
399 }
400 }
401
402 void C2Access::fixup_decorators() {
403 bool default_mo = (_decorators & MO_DECORATOR_MASK) == 0;
404 bool is_unordered = (_decorators & MO_UNORDERED) != 0 || default_mo;
405 bool anonymous = (_decorators & C2_UNSAFE_ACCESS) != 0;
406
407 bool is_read = (_decorators & C2_READ_ACCESS) != 0;
408 bool is_write = (_decorators & C2_WRITE_ACCESS) != 0;
409
410 if (AlwaysAtomicAccesses && is_unordered) {
411 _decorators &= ~MO_DECORATOR_MASK; // clear the MO bits
412 _decorators |= MO_RELAXED; // Force the MO_RELAXED decorator with AlwaysAtomicAccess
413 }
414
415 _decorators = AccessInternal::decorator_fixup(_decorators, _type);
416
417 if (is_read && !is_write && anonymous) {
418 // To be valid, unsafe loads may depend on other conditions than
419 // the one that guards them: pin the Load node
420 _decorators |= C2_CONTROL_DEPENDENT_LOAD;
421 _decorators |= C2_UNKNOWN_CONTROL_LOAD;
422 const TypePtr* adr_type = _addr.type();
423 Node* adr = _addr.node();
424 if (!needs_cpu_membar() && adr_type->isa_instptr()) {
425 assert(adr_type->meet(TypePtr::NULL_PTR) != adr_type->remove_speculative(), "should be not null");
426 intptr_t offset = Type::OffsetBot;
427 AddPNode::Ideal_base_and_offset(adr, &gvn(), offset);
428 if (offset >= 0) {
429 int s = Klass::layout_helper_size_in_bytes(adr_type->isa_instptr()->instance_klass()->layout_helper());
430 if (offset < s) {
431 // Guaranteed to be a valid access, no need to pin it
432 _decorators ^= C2_CONTROL_DEPENDENT_LOAD;
433 _decorators ^= C2_UNKNOWN_CONTROL_LOAD;
434 }
435 }
436 }
437 }
438 }
439
440 //--------------------------- atomic operations---------------------------------
441
442 void BarrierSetC2::pin_atomic_op(C2AtomicParseAccess& access) const {
443 // SCMemProjNodes represent the memory state of a LoadStore. Their
444 // main role is to prevent LoadStore nodes from being optimized away
445 // when their results aren't used.
446 assert(access.is_parse_access(), "entry not supported at optimization time");
447 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
448 GraphKit* kit = parse_access.kit();
449 Node* load_store = access.raw_access();
450 assert(load_store != nullptr, "must pin atomic op");
451 Node* proj = kit->gvn().transform(new SCMemProjNode(load_store));
452 kit->set_memory(proj, access.alias_idx());
453 }
454
455 void C2AtomicParseAccess::set_memory() {
456 Node *mem = _kit->memory(_alias_idx);
457 _memory = mem;
458 }
459
460 Node* BarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
461 Node* new_val, const Type* value_type) const {
462 GraphKit* kit = access.kit();
463 MemNode::MemOrd mo = access.mem_node_mo();
464 Node* mem = access.memory();
465
466 Node* adr = access.addr().node();
467 const TypePtr* adr_type = access.addr().type();
468
469 Node* load_store = nullptr;
470
471 if (access.is_oop()) {
472 #ifdef _LP64
473 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
474 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop()));
475 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop()));
476 load_store = new CompareAndExchangeNNode(kit->control(), mem, adr, newval_enc, oldval_enc, adr_type, value_type->make_narrowoop(), mo);
477 } else
478 #endif
479 {
480 load_store = new CompareAndExchangePNode(kit->control(), mem, adr, new_val, expected_val, adr_type, value_type->is_oopptr(), mo);
481 }
482 } else {
483 switch (access.type()) {
484 case T_BYTE: {
485 load_store = new CompareAndExchangeBNode(kit->control(), mem, adr, new_val, expected_val, adr_type, mo);
486 break;
487 }
488 case T_SHORT: {
489 load_store = new CompareAndExchangeSNode(kit->control(), mem, adr, new_val, expected_val, adr_type, mo);
490 break;
491 }
492 case T_INT: {
493 load_store = new CompareAndExchangeINode(kit->control(), mem, adr, new_val, expected_val, adr_type, mo);
494 break;
495 }
496 case T_LONG: {
497 load_store = new CompareAndExchangeLNode(kit->control(), mem, adr, new_val, expected_val, adr_type, mo);
498 break;
499 }
500 default:
501 ShouldNotReachHere();
502 }
503 }
504
505 load_store->as_LoadStore()->set_barrier_data(access.barrier_data());
506 load_store = kit->gvn().transform(load_store);
507
508 access.set_raw_access(load_store);
509 pin_atomic_op(access);
510
511 #ifdef _LP64
512 if (access.is_oop() && adr->bottom_type()->is_ptr_to_narrowoop()) {
513 return kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type()));
514 }
515 #endif
516
517 return load_store;
518 }
519
520 Node* BarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
521 Node* new_val, const Type* value_type) const {
522 GraphKit* kit = access.kit();
523 DecoratorSet decorators = access.decorators();
524 MemNode::MemOrd mo = access.mem_node_mo();
525 Node* mem = access.memory();
526 bool is_weak_cas = (decorators & C2_WEAK_CMPXCHG) != 0;
527 Node* load_store = nullptr;
528 Node* adr = access.addr().node();
529
530 if (access.is_oop()) {
531 #ifdef _LP64
532 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
533 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop()));
534 Node *oldval_enc = kit->gvn().transform(new EncodePNode(expected_val, expected_val->bottom_type()->make_narrowoop()));
535 if (is_weak_cas) {
536 load_store = new WeakCompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo);
537 } else {
538 load_store = new CompareAndSwapNNode(kit->control(), mem, adr, newval_enc, oldval_enc, mo);
539 }
540 } else
541 #endif
542 {
543 if (is_weak_cas) {
544 load_store = new WeakCompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo);
545 } else {
546 load_store = new CompareAndSwapPNode(kit->control(), mem, adr, new_val, expected_val, mo);
547 }
548 }
549 } else {
550 switch(access.type()) {
551 case T_BYTE: {
552 if (is_weak_cas) {
553 load_store = new WeakCompareAndSwapBNode(kit->control(), mem, adr, new_val, expected_val, mo);
554 } else {
555 load_store = new CompareAndSwapBNode(kit->control(), mem, adr, new_val, expected_val, mo);
556 }
557 break;
558 }
559 case T_SHORT: {
560 if (is_weak_cas) {
561 load_store = new WeakCompareAndSwapSNode(kit->control(), mem, adr, new_val, expected_val, mo);
562 } else {
563 load_store = new CompareAndSwapSNode(kit->control(), mem, adr, new_val, expected_val, mo);
564 }
565 break;
566 }
567 case T_INT: {
568 if (is_weak_cas) {
569 load_store = new WeakCompareAndSwapINode(kit->control(), mem, adr, new_val, expected_val, mo);
570 } else {
571 load_store = new CompareAndSwapINode(kit->control(), mem, adr, new_val, expected_val, mo);
572 }
573 break;
574 }
575 case T_LONG: {
576 if (is_weak_cas) {
577 load_store = new WeakCompareAndSwapLNode(kit->control(), mem, adr, new_val, expected_val, mo);
578 } else {
579 load_store = new CompareAndSwapLNode(kit->control(), mem, adr, new_val, expected_val, mo);
580 }
581 break;
582 }
583 default:
584 ShouldNotReachHere();
585 }
586 }
587
588 load_store->as_LoadStore()->set_barrier_data(access.barrier_data());
589 load_store = kit->gvn().transform(load_store);
590
591 access.set_raw_access(load_store);
592 pin_atomic_op(access);
593
594 return load_store;
595 }
596
597 Node* BarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const {
598 GraphKit* kit = access.kit();
599 Node* mem = access.memory();
600 Node* adr = access.addr().node();
601 const TypePtr* adr_type = access.addr().type();
602 Node* load_store = nullptr;
603
604 if (access.is_oop()) {
605 #ifdef _LP64
606 if (adr->bottom_type()->is_ptr_to_narrowoop()) {
607 Node *newval_enc = kit->gvn().transform(new EncodePNode(new_val, new_val->bottom_type()->make_narrowoop()));
608 load_store = kit->gvn().transform(new GetAndSetNNode(kit->control(), mem, adr, newval_enc, adr_type, value_type->make_narrowoop()));
609 } else
610 #endif
611 {
612 load_store = new GetAndSetPNode(kit->control(), mem, adr, new_val, adr_type, value_type->is_oopptr());
613 }
614 } else {
615 switch (access.type()) {
616 case T_BYTE:
617 load_store = new GetAndSetBNode(kit->control(), mem, adr, new_val, adr_type);
618 break;
619 case T_SHORT:
620 load_store = new GetAndSetSNode(kit->control(), mem, adr, new_val, adr_type);
621 break;
622 case T_INT:
623 load_store = new GetAndSetINode(kit->control(), mem, adr, new_val, adr_type);
624 break;
625 case T_LONG:
626 load_store = new GetAndSetLNode(kit->control(), mem, adr, new_val, adr_type);
627 break;
628 default:
629 ShouldNotReachHere();
630 }
631 }
632
633 load_store->as_LoadStore()->set_barrier_data(access.barrier_data());
634 load_store = kit->gvn().transform(load_store);
635
636 access.set_raw_access(load_store);
637 pin_atomic_op(access);
638
639 #ifdef _LP64
640 if (access.is_oop() && adr->bottom_type()->is_ptr_to_narrowoop()) {
641 return kit->gvn().transform(new DecodeNNode(load_store, load_store->get_ptr_type()));
642 }
643 #endif
644
645 return load_store;
646 }
647
648 Node* BarrierSetC2::atomic_add_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const {
649 Node* load_store = nullptr;
650 GraphKit* kit = access.kit();
651 Node* adr = access.addr().node();
652 const TypePtr* adr_type = access.addr().type();
653 Node* mem = access.memory();
654
655 switch(access.type()) {
656 case T_BYTE:
657 load_store = new GetAndAddBNode(kit->control(), mem, adr, new_val, adr_type);
658 break;
659 case T_SHORT:
660 load_store = new GetAndAddSNode(kit->control(), mem, adr, new_val, adr_type);
661 break;
662 case T_INT:
663 load_store = new GetAndAddINode(kit->control(), mem, adr, new_val, adr_type);
664 break;
665 case T_LONG:
666 load_store = new GetAndAddLNode(kit->control(), mem, adr, new_val, adr_type);
667 break;
668 default:
669 ShouldNotReachHere();
670 }
671
672 load_store->as_LoadStore()->set_barrier_data(access.barrier_data());
673 load_store = kit->gvn().transform(load_store);
674
675 access.set_raw_access(load_store);
676 pin_atomic_op(access);
677
678 return load_store;
679 }
680
681 Node* BarrierSetC2::atomic_cmpxchg_val_at(C2AtomicParseAccess& access, Node* expected_val,
682 Node* new_val, const Type* value_type) const {
683 C2AccessFence fence(access);
684 resolve_address(access);
685 return atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);
686 }
687
688 Node* BarrierSetC2::atomic_cmpxchg_bool_at(C2AtomicParseAccess& access, Node* expected_val,
689 Node* new_val, const Type* value_type) const {
690 C2AccessFence fence(access);
691 resolve_address(access);
692 return atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
693 }
694
695 Node* BarrierSetC2::atomic_xchg_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const {
696 C2AccessFence fence(access);
697 resolve_address(access);
698 return atomic_xchg_at_resolved(access, new_val, value_type);
699 }
700
701 Node* BarrierSetC2::atomic_add_at(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const {
702 C2AccessFence fence(access);
703 resolve_address(access);
704 return atomic_add_at_resolved(access, new_val, value_type);
705 }
706
707 int BarrierSetC2::arraycopy_payload_base_offset(bool is_array) {
708 // Exclude the header but include array length to copy by 8 bytes words.
709 // Can't use base_offset_in_bytes(bt) since basic type is unknown.
710 int base_off = is_array ? arrayOopDesc::length_offset_in_bytes() :
711 instanceOopDesc::base_offset_in_bytes();
712 // base_off:
713 // 8 - 32-bit VM
714 // 12 - 64-bit VM, compressed klass
715 // 16 - 64-bit VM, normal klass
716 if (base_off % BytesPerLong != 0) {
717 assert(UseCompressedClassPointers, "");
718 if (is_array) {
719 // Exclude length to copy by 8 bytes words.
720 base_off += sizeof(int);
721 } else {
722 // Include klass to copy by 8 bytes words.
723 base_off = instanceOopDesc::klass_offset_in_bytes();
724 }
725 assert(base_off % BytesPerLong == 0, "expect 8 bytes alignment");
726 }
727 return base_off;
728 }
729
730 void BarrierSetC2::clone(GraphKit* kit, Node* src_base, Node* dst_base, Node* size, bool is_array) const {
731 int base_off = arraycopy_payload_base_offset(is_array);
732 Node* payload_size = size;
733 Node* offset = kit->MakeConX(base_off);
734 payload_size = kit->gvn().transform(new SubXNode(payload_size, offset));
735 if (is_array) {
736 // Ensure the array payload size is rounded up to the next BytesPerLong
737 // multiple when converting to double-words. This is necessary because array
738 // size does not include object alignment padding, so it might not be a
739 // multiple of BytesPerLong for sub-long element types.
740 payload_size = kit->gvn().transform(new AddXNode(payload_size, kit->MakeConX(BytesPerLong - 1)));
741 }
742 payload_size = kit->gvn().transform(new URShiftXNode(payload_size, kit->intcon(LogBytesPerLong)));
743 ArrayCopyNode* ac = ArrayCopyNode::make(kit, false, src_base, offset, dst_base, offset, payload_size, true, false);
744 if (is_array) {
745 ac->set_clone_array();
746 } else {
747 ac->set_clone_inst();
748 }
749 Node* n = kit->gvn().transform(ac);
750 if (n == ac) {
751 const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
752 ac->set_adr_type(TypeRawPtr::BOTTOM);
753 kit->set_predefined_output_for_runtime_call(ac, ac->in(TypeFunc::Memory), raw_adr_type);
754 } else {
755 kit->set_all_memory(n);
756 }
757 }
758
759 Node* BarrierSetC2::obj_allocate(PhaseMacroExpand* macro, Node* mem, Node* toobig_false, Node* size_in_bytes,
760 Node*& i_o, Node*& needgc_ctrl,
761 Node*& fast_oop_ctrl, Node*& fast_oop_rawmem,
762 intx prefetch_lines) const {
763 assert(UseTLAB, "Only for TLAB enabled allocations");
764
765 Node* thread = macro->transform_later(new ThreadLocalNode());
766 Node* tlab_top_adr = macro->basic_plus_adr(macro->top()/*not oop*/, thread, in_bytes(JavaThread::tlab_top_offset()));
767 Node* tlab_end_adr = macro->basic_plus_adr(macro->top()/*not oop*/, thread, in_bytes(JavaThread::tlab_end_offset()));
768
769 // Load TLAB end.
770 //
771 // Note: We set the control input on "tlab_end" and "old_tlab_top" to work around
772 // a bug where these values were being moved across
773 // a safepoint. These are not oops, so they cannot be include in the oop
774 // map, but they can be changed by a GC. The proper way to fix this would
775 // be to set the raw memory state when generating a SafepointNode. However
776 // this will require extensive changes to the loop optimization in order to
777 // prevent a degradation of the optimization.
778 // See comment in memnode.hpp, around line 227 in class LoadPNode.
779 Node* tlab_end = macro->make_load(toobig_false, mem, tlab_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
780
781 // Load the TLAB top.
782 Node* old_tlab_top = new LoadPNode(toobig_false, mem, tlab_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM, MemNode::unordered);
783 macro->transform_later(old_tlab_top);
784
785 // Add to heap top to get a new TLAB top
786 Node* new_tlab_top = new AddPNode(macro->top(), old_tlab_top, size_in_bytes);
787 macro->transform_later(new_tlab_top);
788
789 // Check against TLAB end
790 Node* tlab_full = new CmpPNode(new_tlab_top, tlab_end);
791 macro->transform_later(tlab_full);
792
793 Node* needgc_bol = new BoolNode(tlab_full, BoolTest::ge);
794 macro->transform_later(needgc_bol);
795 IfNode* needgc_iff = new IfNode(toobig_false, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN);
796 macro->transform_later(needgc_iff);
797
798 // Plug the failing-heap-space-need-gc test into the slow-path region
799 Node* needgc_true = new IfTrueNode(needgc_iff);
800 macro->transform_later(needgc_true);
801 needgc_ctrl = needgc_true;
802
803 // No need for a GC.
804 Node* needgc_false = new IfFalseNode(needgc_iff);
805 macro->transform_later(needgc_false);
806
807 // Fast path:
808 i_o = macro->prefetch_allocation(i_o, needgc_false, mem,
809 old_tlab_top, new_tlab_top, prefetch_lines);
810
811 // Store the modified TLAB top back down.
812 Node* store_tlab_top = new StorePNode(needgc_false, mem, tlab_top_adr,
813 TypeRawPtr::BOTTOM, new_tlab_top, MemNode::unordered);
814 macro->transform_later(store_tlab_top);
815
816 fast_oop_ctrl = needgc_false;
817 fast_oop_rawmem = store_tlab_top;
818 return old_tlab_top;
819 }
820
821 static const TypeFunc* clone_type() {
822 // Create input type (domain)
823 int argcnt = NOT_LP64(3) LP64_ONLY(4);
824 const Type** const domain_fields = TypeTuple::fields(argcnt);
825 int argp = TypeFunc::Parms;
826 domain_fields[argp++] = TypeInstPtr::NOTNULL; // src
827 domain_fields[argp++] = TypeInstPtr::NOTNULL; // dst
828 domain_fields[argp++] = TypeX_X; // size lower
829 LP64_ONLY(domain_fields[argp++] = Type::HALF); // size upper
830 assert(argp == TypeFunc::Parms+argcnt, "correct decoding");
831 const TypeTuple* const domain = TypeTuple::make(TypeFunc::Parms + argcnt, domain_fields);
832
833 // Create result type (range)
834 const Type** const range_fields = TypeTuple::fields(0);
835 const TypeTuple* const range = TypeTuple::make(TypeFunc::Parms + 0, range_fields);
836
837 return TypeFunc::make(domain, range);
838 }
839
840 #define XTOP LP64_ONLY(COMMA phase->top())
841
842 void BarrierSetC2::clone_in_runtime(PhaseMacroExpand* phase, ArrayCopyNode* ac,
843 address clone_addr, const char* clone_name) const {
844 Node* const ctrl = ac->in(TypeFunc::Control);
845 Node* const mem = ac->in(TypeFunc::Memory);
846 Node* const src = ac->in(ArrayCopyNode::Src);
847 Node* const dst = ac->in(ArrayCopyNode::Dest);
848 Node* const size = ac->in(ArrayCopyNode::Length);
849
850 assert(size->bottom_type()->base() == Type_X,
851 "Should be of object size type (int for 32 bits, long for 64 bits)");
852
853 // The native clone we are calling here expects the object size in words.
854 // Add header/offset size to payload size to get object size.
855 Node* const base_offset = phase->MakeConX(arraycopy_payload_base_offset(ac->is_clone_array()) >> LogBytesPerLong);
856 Node* const full_size = phase->transform_later(new AddXNode(size, base_offset));
857 // HeapAccess<>::clone expects size in heap words.
858 // For 64-bits platforms, this is a no-operation.
859 // For 32-bits platforms, we need to multiply full_size by HeapWordsPerLong (2).
860 Node* const full_size_in_heap_words = phase->transform_later(new LShiftXNode(full_size, phase->intcon(LogHeapWordsPerLong)));
861
862 Node* const call = phase->make_leaf_call(ctrl,
863 mem,
864 clone_type(),
865 clone_addr,
866 clone_name,
867 TypeRawPtr::BOTTOM,
868 src, dst, full_size_in_heap_words XTOP);
869 phase->transform_later(call);
870 phase->replace_node(ac, call);
871 }
872
873 void BarrierSetC2::clone_at_expansion(PhaseMacroExpand* phase, ArrayCopyNode* ac) const {
874 Node* ctrl = ac->in(TypeFunc::Control);
875 Node* mem = ac->in(TypeFunc::Memory);
876 Node* src = ac->in(ArrayCopyNode::Src);
877 Node* src_offset = ac->in(ArrayCopyNode::SrcPos);
878 Node* dest = ac->in(ArrayCopyNode::Dest);
879 Node* dest_offset = ac->in(ArrayCopyNode::DestPos);
880 Node* length = ac->in(ArrayCopyNode::Length);
881
882 Node* payload_src = phase->basic_plus_adr(src, src_offset);
883 Node* payload_dst = phase->basic_plus_adr(dest, dest_offset);
884
885 const char* copyfunc_name = "arraycopy";
886 address copyfunc_addr = phase->basictype2arraycopy(T_LONG, nullptr, nullptr, true, copyfunc_name, true);
887
888 const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
889 const TypeFunc* call_type = OptoRuntime::fast_arraycopy_Type();
890
891 Node* call = phase->make_leaf_call(ctrl, mem, call_type, copyfunc_addr, copyfunc_name, raw_adr_type, payload_src, payload_dst, length XTOP);
892 phase->transform_later(call);
893
894 phase->replace_node(ac, call);
895 }
896
897 #undef XTOP
898
899 void BarrierSetC2::compute_liveness_at_stubs() const {
900 ResourceMark rm;
901 Compile* const C = Compile::current();
902 Arena* const A = Thread::current()->resource_area();
903 PhaseCFG* const cfg = C->cfg();
904 PhaseRegAlloc* const regalloc = C->regalloc();
905 RegMask* const live = NEW_ARENA_ARRAY(A, RegMask, cfg->number_of_blocks() * sizeof(RegMask));
906 BarrierSetAssembler* const bs = BarrierSet::barrier_set()->barrier_set_assembler();
907 BarrierSetC2State* bs_state = barrier_set_state();
908 Block_List worklist;
909
910 for (uint i = 0; i < cfg->number_of_blocks(); ++i) {
911 new ((void*)(live + i)) RegMask();
912 worklist.push(cfg->get_block(i));
913 }
914
915 while (worklist.size() > 0) {
916 const Block* const block = worklist.pop();
917 RegMask& old_live = live[block->_pre_order];
918 RegMask new_live;
919
920 // Initialize to union of successors
921 for (uint i = 0; i < block->_num_succs; i++) {
922 const uint succ_id = block->_succs[i]->_pre_order;
923 new_live.OR(live[succ_id]);
924 }
925
926 // Walk block backwards, computing liveness
927 for (int i = block->number_of_nodes() - 1; i >= 0; --i) {
928 const Node* const node = block->get_node(i);
929
930 // If this node tracks out-liveness, update it
931 if (!bs_state->needs_livein_data()) {
932 RegMask* const regs = bs_state->live(node);
933 if (regs != nullptr) {
934 regs->OR(new_live);
935 }
936 }
937
938 // Remove def bits
939 const OptoReg::Name first = bs->refine_register(node, regalloc->get_reg_first(node));
940 const OptoReg::Name second = bs->refine_register(node, regalloc->get_reg_second(node));
941 if (first != OptoReg::Bad) {
942 new_live.Remove(first);
943 }
944 if (second != OptoReg::Bad) {
945 new_live.Remove(second);
946 }
947
948 // Add use bits
949 for (uint j = 1; j < node->req(); ++j) {
950 const Node* const use = node->in(j);
951 const OptoReg::Name first = bs->refine_register(use, regalloc->get_reg_first(use));
952 const OptoReg::Name second = bs->refine_register(use, regalloc->get_reg_second(use));
953 if (first != OptoReg::Bad) {
954 new_live.Insert(first);
955 }
956 if (second != OptoReg::Bad) {
957 new_live.Insert(second);
958 }
959 }
960
961 // If this node tracks in-liveness, update it
962 if (bs_state->needs_livein_data()) {
963 RegMask* const regs = bs_state->live(node);
964 if (regs != nullptr) {
965 regs->OR(new_live);
966 }
967 }
968 }
969
970 // Now at block top, see if we have any changes
971 new_live.SUBTRACT(old_live);
972 if (new_live.is_NotEmpty()) {
973 // Liveness has refined, update and propagate to prior blocks
974 old_live.OR(new_live);
975 for (uint i = 1; i < block->num_preds(); ++i) {
976 Block* const pred = cfg->get_block_for_node(block->pred(i));
977 worklist.push(pred);
978 }
979 }
980 }
981 }