1 /*
2 * Copyright (c) 2017, 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 "opto/arraycopynode.hpp"
27 #include "opto/graphKit.hpp"
28 #include "opto/idealKit.hpp"
29 #include "opto/narrowptrnode.hpp"
30 #include "gc/shared/c2ModRefBSCodeGen.hpp"
31 #include "utilities/macros.hpp"
32
33 Node* C2ModRefBSCodeGen::store_at_resolved(GraphKit* kit, Node* obj, Node* adr, const TypePtr* adr_type, Node* val, const Type* val_type, BasicType bt, C2DecoratorSet decorators) {
34 bool on_array = (decorators & C2_ACCESS_ON_ARRAY) != 0;
35 bool anonymous = (decorators & C2_ACCESS_ON_ANONYMOUS) != 0;
36 bool on_heap = (decorators & C2_ACCESS_ON_HEAP) != 0;
37 bool use_precise = on_array || anonymous;
38 bool is_obj = bt == T_OBJECT || bt == T_ARRAY;
39
40 if (!is_obj || (!on_heap && !anonymous)) {
41 return C2BarrierSetCodeGen::store_at_resolved(kit, obj, adr, adr_type, val, val_type, bt, decorators);
42 }
43
44 uint adr_idx = kit->C->get_alias_index(adr_type);
45 assert(adr_idx != Compile::AliasIdxTop, "use other store_to_memory factory" );
46
47 pre_barrier(kit, true /* do_load */, kit->control(), obj, adr, adr_idx, val,
48 static_cast<const TypeOopPtr*>(val_type), NULL /* pre_val */, bt);
49 Node* store = C2BarrierSetCodeGen::store_at_resolved(kit, obj, adr, adr_type, val, val_type, bt, decorators);
50 post_barrier(kit, kit->control(), store, obj, adr, adr_idx, val, bt, use_precise);
51
52 return store;
53 }
54
55 Node* C2ModRefBSCodeGen::cas_val_at_resolved(GraphKit* kit, Node* obj, Node* adr, const TypePtr* adr_type, int alias_idx, Node* expected_val, Node* new_val, const Type* value_type, Node* mem, Node*& load_store, BasicType bt, C2DecoratorSet decorators) {
56 bool is_obj = bt == T_OBJECT || bt == T_ARRAY;
57 if (!is_obj) {
58 return C2BarrierSetCodeGen::cas_val_at_resolved(kit, obj, adr, adr_type, alias_idx, expected_val, new_val, value_type, mem, load_store, bt, decorators);
59 }
60
61 pre_barrier(kit, false /* do_load */,
62 kit->control(), NULL, NULL, max_juint, NULL, NULL,
63 expected_val /* pre_val */,
64 T_OBJECT);
65
66 Node* result = C2BarrierSetCodeGen::cas_val_at_resolved(kit, obj, adr, adr_type, alias_idx, expected_val, new_val, value_type, mem, load_store, bt, decorators);
67
68 post_barrier(kit, kit->control(), load_store, obj, adr, alias_idx, new_val, T_OBJECT, true);
69
70 return result;
71 }
72
73 Node* C2ModRefBSCodeGen::cas_bool_at_resolved(GraphKit* kit, Node* obj, Node* adr, const TypePtr* adr_type, int alias_idx, Node* expected_val, Node* new_val, const Type* value_type, Node* mem, BasicType bt, C2DecoratorSet decorators) {
74 bool is_obj = bt == T_OBJECT || bt == T_ARRAY;
75 if (!is_obj) {
76 return C2BarrierSetCodeGen::cas_bool_at_resolved(kit, obj, adr, adr_type, alias_idx, expected_val, new_val, value_type, mem, bt, decorators);
77 }
78
79 pre_barrier(kit, false /* do_load */,
80 kit->control(), NULL, NULL, max_juint, NULL, NULL,
81 expected_val /* pre_val */,
82 T_OBJECT);
83
84 Node* load_store = C2BarrierSetCodeGen::cas_bool_at_resolved(kit, obj, adr, adr_type, alias_idx, expected_val, new_val, value_type, mem, bt, decorators);
85
86 // Emit the post barrier only when the actual store happened. This makes sense
87 // to check only for LS_cmp_* that can fail to set the value.
88 // LS_cmp_exchange does not produce any branches by default, so there is no
89 // boolean result to piggyback on. TODO: When we merge CompareAndSwap with
90 // CompareAndExchange and move branches here, it would make sense to conditionalize
91 // post_barriers for LS_cmp_exchange as well.
92 //
93 // CAS success path is marked more likely since we anticipate this is a performance
94 // critical path, while CAS failure path can use the penalty for going through unlikely
95 // path as backoff. Which is still better than doing a store barrier there.
96 IdealKit ideal(kit);
97 ideal.if_then(load_store, BoolTest::ne, ideal.ConI(0), PROB_STATIC_FREQUENT); {
98 kit->sync_kit(ideal);
99 post_barrier(kit, ideal.ctrl(), load_store, obj, adr, alias_idx, new_val, T_OBJECT, true);
100 ideal.sync_kit(kit);
101 } ideal.end_if();
102 kit->final_sync(ideal);
103
104 return load_store;
105 }
106
107 Node* C2ModRefBSCodeGen::swap_at_resolved(GraphKit* kit, Node* obj, Node* adr, const TypePtr* adr_type, int alias_idx, Node* new_val, const Type* value_type, Node* mem, Node*& load_store, BasicType bt, C2DecoratorSet decorators) {
108 bool is_obj = bt == T_OBJECT || bt == T_ARRAY;
109 Node* result = C2BarrierSetCodeGen::swap_at_resolved(kit, obj, adr, adr_type, alias_idx, new_val, value_type, mem, load_store, bt, decorators);
110 if (!is_obj) {
111 return result;
112 }
113
114 // Don't need to load pre_val. The old value is returned by load_store.
115 // The pre_barrier can execute after the xchg as long as no safepoint
116 // gets inserted between them.
117 pre_barrier(kit, false /* do_load */,
118 kit->control(), NULL, NULL, max_juint, NULL, NULL,
119 result /* pre_val */,
120 T_OBJECT);
121 post_barrier(kit, kit->control(), load_store, obj, adr, alias_idx, new_val, T_OBJECT, true);
122
123 return result;
124 }