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 }