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.
22 *
23 */
24
25 #include "gc/shared/c1/cardTableBarrierSetC1.hpp"
26 #include "gc/shared/cardTable.hpp"
27 #include "gc/shared/cardTableBarrierSet.hpp"
28 #include "gc/shared/gc_globals.hpp"
29 #include "utilities/macros.hpp"
30
31 #ifdef ASSERT
32 #define __ gen->lir(__FILE__, __LINE__)->
33 #else
34 #define __ gen->lir()->
35 #endif
36
37 void CardTableBarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) {
38 DecoratorSet decorators = access.decorators();
39 bool is_array = (decorators & IS_ARRAY) != 0;
40 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
41
42 if (access.is_oop()) {
43 pre_barrier(access, access.resolved_addr(),
44 LIR_OprFact::illegalOpr /* pre_val */, access.patch_emit_info());
45 }
46
47 BarrierSetC1::store_at_resolved(access, value);
48
49 if (access.is_oop()) {
50 bool precise = is_array || on_anonymous;
51 LIR_Opr post_addr = precise ? access.resolved_addr() : access.base().opr();
52 post_barrier(access, post_addr, value);
53 }
54 }
55
56 LIR_Opr CardTableBarrierSetC1::atomic_cmpxchg_at_resolved(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) {
57 if (access.is_oop()) {
58 pre_barrier(access, access.resolved_addr(),
59 LIR_OprFact::illegalOpr /* pre_val */, nullptr);
60 }
61
62 LIR_Opr result = BarrierSetC1::atomic_cmpxchg_at_resolved(access, cmp_value, new_value);
63
64 if (access.is_oop()) {
65 post_barrier(access, access.resolved_addr(), new_value.result());
66 }
67
68 return result;
69 }
70
71 LIR_Opr CardTableBarrierSetC1::atomic_xchg_at_resolved(LIRAccess& access, LIRItem& value) {
72 if (access.is_oop()) {
73 pre_barrier(access, access.resolved_addr(),
74 LIR_OprFact::illegalOpr /* pre_val */, nullptr);
75 }
76
77 LIR_Opr result = BarrierSetC1::atomic_xchg_at_resolved(access, value);
78
79 if (access.is_oop()) {
80 post_barrier(access, access.resolved_addr(), value.result());
81 }
82
83 return result;
84 }
85
86 // This overrides the default to resolve the address into a register,
87 // assuming it will be used by a write barrier anyway.
88 LIR_Opr CardTableBarrierSetC1::resolve_address(LIRAccess& access, bool resolve_in_register) {
89 DecoratorSet decorators = access.decorators();
90 bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0;
91 bool is_write = (decorators & ACCESS_WRITE) != 0;
92 bool is_array = (decorators & IS_ARRAY) != 0;
93 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
94 bool precise = is_array || on_anonymous;
95 resolve_in_register |= !needs_patching && is_write && access.is_oop() && precise;
96 return BarrierSetC1::resolve_address(access, resolve_in_register);
97 }
98
99 void CardTableBarrierSetC1::post_barrier(LIRAccess& access, LIR_Opr addr, LIR_Opr new_val) {
100 DecoratorSet decorators = access.decorators();
101 LIRGenerator* gen = access.gen();
102 bool in_heap = (decorators & IN_HEAP) != 0;
103 if (!in_heap) {
104 return;
105 }
106
107 BarrierSet* bs = BarrierSet::barrier_set();
108 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
109 CardTable* ct = ctbs->card_table();
110 LIR_Const* card_table_base = new LIR_Const(ct->byte_map_base());
111 SHENANDOAHGC_ONLY(assert(!UseShenandoahGC, "Shenandoah byte_map_base is not constant.");)
112
113 if (addr->is_address()) {
114 LIR_Address* address = addr->as_address_ptr();
115 // ptr cannot be an object because we use this barrier for array card marks
116 // and addr can point in the middle of an array.
117 LIR_Opr ptr = gen->new_pointer_register();
118 if (!address->index()->is_valid() && address->disp() == 0) {
119 __ move(address->base(), ptr);
120 } else {
121 assert(address->disp() != max_jint, "lea doesn't support patched addresses!");
122 __ leal(addr, ptr);
123 }
124 addr = ptr;
125 }
126 assert(addr->is_register(), "must be a register at this point");
127
128 #ifdef CARDTABLEBARRIERSET_POST_BARRIER_HELPER
129 gen->CardTableBarrierSet_post_barrier_helper(addr, card_table_base);
130 #else
131 LIR_Opr tmp = gen->new_pointer_register();
132 if (two_operand_lir_form) {
133 LIR_Opr addr_opr = LIR_OprFact::address(new LIR_Address(addr, addr->type()));
134 __ leal(addr_opr, tmp);
135 __ unsigned_shift_right(tmp, CardTable::card_shift(), tmp);
136 } else {
137 __ unsigned_shift_right(addr, CardTable::card_shift(), tmp);
138 }
139
140 LIR_Address* card_addr;
141 if (gen->can_inline_as_constant(card_table_base)) {
142 card_addr = new LIR_Address(tmp, card_table_base->as_jint(), T_BYTE);
143 } else {
144 card_addr = new LIR_Address(tmp, gen->load_constant(card_table_base), T_BYTE);
145 }
146
147 LIR_Opr dirty = LIR_OprFact::intConst(CardTable::dirty_card_val());
148 if (UseCondCardMark) {
149 LIR_Opr cur_value = gen->new_register(T_INT);
150 __ move(card_addr, cur_value);
151
152 LabelObj* L_already_dirty = new LabelObj();
153 __ cmp(lir_cond_equal, cur_value, dirty);
154 __ branch(lir_cond_equal, L_already_dirty->label());
155 __ move(dirty, card_addr);
156 __ branch_destination(L_already_dirty->label());
157 } else {
158 __ move(dirty, card_addr);
159 }
160 #endif
161 }