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