1 /*
2 * Copyright (c) 2018, 2025, 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.
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23 */
24
25 #include "opto/arraycopynode.hpp"
26 #include "opto/graphKit.hpp"
27 #include "opto/idealKit.hpp"
28 #include "gc/shared/c2/modRefBarrierSetC2.hpp"
29
30 Node* ModRefBarrierSetC2::store_at_resolved(C2Access& access, C2AccessValue& val) const {
31 DecoratorSet decorators = access.decorators();
32
33 Node* adr = access.addr().node();
34
35 bool is_array = (decorators & IS_ARRAY) != 0;
36 bool anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
37 bool in_heap = (decorators & IN_HEAP) != 0;
38 bool use_precise = is_array || anonymous;
39 bool tightly_coupled_alloc = (decorators & C2_TIGHTLY_COUPLED_ALLOC) != 0;
40
41 const InlineTypeNode* vt = nullptr;
42 if (access.is_parse_access() && static_cast<C2ParseAccess&>(access).vt() != nullptr) {
43 vt = static_cast<C2ParseAccess&>(access).vt();
44 }
45
46 if (vt == nullptr && (!access.is_oop() || tightly_coupled_alloc || (!in_heap && !anonymous))) {
47 return BarrierSetC2::store_at_resolved(access, val);
48 }
49
50 assert(access.is_parse_access(), "entry not supported at optimization time");
51 C2ParseAccess& parse_access = static_cast<C2ParseAccess&>(access);
52
53 Node* store = BarrierSetC2::store_at_resolved(access, val);
54
55 // TODO 8350865
56 // - We actually only need the post barrier once for non-arrays (same for C1, right)?
57 // - Value is only needed to determine if we are storing null. Maybe we can go with a simple boolean?
58 GraphKit* kit = parse_access.kit();
59 if (vt != nullptr) {
60 for (uint i = 0; i < vt->field_count(); ++i) {
61 ciType* type = vt->field_type(i);
62 if (!type->is_primitive_type()) {
63 ciInlineKlass* vk = vt->bottom_type()->inline_klass();
64 int field_offset = vt->field_offset(i) - vk->payload_offset();
65 Node* value = vt->field_value(i);
66 Node* field_adr = kit->basic_plus_adr(access.base(), adr, field_offset);
67 post_barrier(kit, access.base(), field_adr, value, use_precise);
68 }
69 }
70 } else {
71 post_barrier(kit, access.base(), adr, val.node(), use_precise);
72 }
73
74 return store;
75 }
76
77 Node* ModRefBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
78 Node* new_val, const Type* value_type) const {
79 if (!access.is_oop()) {
80 return BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);
81 }
82
83 Node* result = BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, value_type);
84
85 post_barrier(access.kit(), access.base(), access.addr().node(), new_val, true);
86
87 return result;
88 }
89
90 Node* ModRefBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicParseAccess& access, Node* expected_val,
91 Node* new_val, const Type* value_type) const {
92 GraphKit* kit = access.kit();
93
94 if (!access.is_oop()) {
95 return BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
96 }
97
98 Node* load_store = BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type);
99
100 // Emit the post barrier only when the actual store happened. This makes sense
101 // to check only for LS_cmp_* that can fail to set the value.
102 // LS_cmp_exchange does not produce any branches by default, so there is no
103 // boolean result to piggyback on. TODO: When we merge CompareAndSwap with
104 // CompareAndExchange and move branches here, it would make sense to conditionalize
105 // post_barriers for LS_cmp_exchange as well.
106 //
107 // CAS success path is marked more likely since we anticipate this is a performance
108 // critical path, while CAS failure path can use the penalty for going through unlikely
109 // path as backoff. Which is still better than doing a store barrier there.
110 IdealKit ideal(kit);
111 ideal.if_then(load_store, BoolTest::ne, ideal.ConI(0), PROB_STATIC_FREQUENT); {
112 kit->sync_kit(ideal);
113 post_barrier(kit, access.base(), access.addr().node(), new_val, true);
114 ideal.sync_kit(kit);
115 } ideal.end_if();
116 kit->final_sync(ideal);
117
118 return load_store;
119 }
120
121 Node* ModRefBarrierSetC2::atomic_xchg_at_resolved(C2AtomicParseAccess& access, Node* new_val, const Type* value_type) const {
122 Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, new_val, value_type);
123 if (!access.is_oop()) {
124 return result;
125 }
126
127 post_barrier(access.kit(), access.base(), access.addr().node(), new_val, true);
128
129 return result;
130 }