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 "ci/ciInlineKlass.hpp"
26 #include "code/aotCodeCache.hpp"
27 #include "gc/shared/c1/cardTableBarrierSetC1.hpp"
28 #include "gc/shared/cardTable.hpp"
29 #include "gc/shared/cardTableBarrierSet.hpp"
30 #include "gc/shared/gc_globals.hpp"
31 #include "utilities/macros.hpp"
32
33 #ifdef ASSERT
34 #define __ gen->lir(__FILE__, __LINE__)->
35 #else
36 #define __ gen->lir()->
37 #endif
38
39 void CardTableBarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) {
40 DecoratorSet decorators = access.decorators();
41 bool is_array = (decorators & IS_ARRAY) != 0;
42 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
43
44 // Is this a flat, atomic access that might require gc barriers on oop fields?
45 ciInlineKlass* vk = access.vk();
46 if (vk != nullptr && vk->has_object_fields()) {
47 // Add pre-barriers for oop fields
48 for (int i = 0; i < vk->nof_nonstatic_fields(); i++) {
49 ciField* field = vk->nonstatic_field_at(i);
50 if (!field->type()->is_primitive_type()) {
51 int off = access.offset().opr().as_jint() + field->offset_in_bytes() - vk->payload_offset();
52 LIRAccess inner_access(access.gen(), decorators, access.base(), LIR_OprFact::intConst(off), field->type()->basic_type(), access.patch_emit_info(), access.access_emit_info());
53 pre_barrier(inner_access, resolve_address(inner_access, false),
54 LIR_OprFact::illegalOpr /* pre_val */, inner_access.patch_emit_info());
55 }
56 }
57 }
58
59 if (access.is_oop()) {
60 pre_barrier(access, access.resolved_addr(),
61 LIR_OprFact::illegalOpr /* pre_val */, access.patch_emit_info());
62 }
63
64 BarrierSetC1::store_at_resolved(access, value);
65
66 if (access.is_oop()) {
67 bool precise = is_array || on_anonymous;
68 LIR_Opr post_addr = precise ? access.resolved_addr() : access.base().opr();
69 post_barrier(access, post_addr, value);
70 }
71
72 if (vk != nullptr && vk->has_object_fields()) {
73 // Add post-barriers for oop fields
74 for (int i = 0; i < vk->nof_nonstatic_fields(); i++) {
75 ciField* field = vk->nonstatic_field_at(i);
76 if (!field->type()->is_primitive_type()) {
77 int inner_off = field->offset_in_bytes() - vk->payload_offset();
78 int off = access.offset().opr().as_jint() + inner_off;
79 LIRAccess inner_access(access.gen(), decorators, access.base(), LIR_OprFact::intConst(off), field->type()->basic_type(), access.patch_emit_info(), access.access_emit_info());
80
81 // Shift long value to extract the narrow oop field value and zero-extend
82 LIR_Opr field_val = access.gen()->new_register(T_LONG);
83 access.gen()->lir()->unsigned_shift_right(value,
84 LIR_OprFact::intConst(inner_off << LogBitsPerByte),
85 field_val, LIR_Opr::illegalOpr());
86 LIR_Opr mask = access.gen()->load_immediate((julong) max_juint, T_LONG);
87 access.gen()->lir()->logical_and(field_val, mask, field_val);
88 LIR_Opr oop_val = access.gen()->new_register(T_OBJECT);
89 access.gen()->lir()->move(field_val, oop_val);
90
91 assert(!is_array && !on_anonymous, "not suppported");
92 post_barrier(inner_access, access.base().opr(), oop_val);
93 }
94 }
95 }
96 }
97
98 LIR_Opr CardTableBarrierSetC1::atomic_cmpxchg_at_resolved(LIRAccess& access, LIRItem& cmp_value, LIRItem& new_value) {
99 if (access.is_oop()) {
100 pre_barrier(access, access.resolved_addr(),
101 LIR_OprFact::illegalOpr /* pre_val */, nullptr);
102 }
103
104 LIR_Opr result = BarrierSetC1::atomic_cmpxchg_at_resolved(access, cmp_value, new_value);
105
106 if (access.is_oop()) {
107 post_barrier(access, access.resolved_addr(), new_value.result());
108 }
109
110 return result;
111 }
112
113 LIR_Opr CardTableBarrierSetC1::atomic_xchg_at_resolved(LIRAccess& access, LIRItem& value) {
114 if (access.is_oop()) {
115 pre_barrier(access, access.resolved_addr(),
116 LIR_OprFact::illegalOpr /* pre_val */, nullptr);
117 }
118
119 LIR_Opr result = BarrierSetC1::atomic_xchg_at_resolved(access, value);
120
121 if (access.is_oop()) {
122 post_barrier(access, access.resolved_addr(), value.result());
123 }
124
125 return result;
126 }
127
128 // This overrides the default to resolve the address into a register,
129 // assuming it will be used by a write barrier anyway.
130 LIR_Opr CardTableBarrierSetC1::resolve_address(LIRAccess& access, bool resolve_in_register) {
131 DecoratorSet decorators = access.decorators();
132 bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0;
133 bool is_write = (decorators & ACCESS_WRITE) != 0;
134 bool is_array = (decorators & IS_ARRAY) != 0;
135 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
136 bool precise = is_array || on_anonymous;
137 resolve_in_register |= !needs_patching && is_write && access.is_oop() && precise;
138 return BarrierSetC1::resolve_address(access, resolve_in_register);
139 }
140
141 void CardTableBarrierSetC1::post_barrier(LIRAccess& access, LIR_Opr addr, LIR_Opr new_val) {
142 DecoratorSet decorators = access.decorators();
143 LIRGenerator* gen = access.gen();
144 bool in_heap = (decorators & IN_HEAP) != 0;
145 if (!in_heap) {
146 return;
147 }
148
149 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
150 LIR_Const* card_table_base = new LIR_Const(ctbs->card_table_base_const());
151
152 if (addr->is_address()) {
153 LIR_Address* address = addr->as_address_ptr();
154 // ptr cannot be an object because we use this barrier for array card marks
155 // and addr can point in the middle of an array.
156 LIR_Opr ptr = gen->new_pointer_register();
157 if (!address->index()->is_valid() && address->disp() == 0) {
158 __ move(address->base(), ptr);
159 } else {
160 assert(address->disp() != max_jint, "lea doesn't support patched addresses!");
161 __ leal(addr, ptr);
162 }
163 addr = ptr;
164 }
165 assert(addr->is_register(), "must be a register at this point");
166
167 #ifdef CARDTABLEBARRIERSET_POST_BARRIER_HELPER
168 assert(!AOTCodeCache::is_on(), "this path is not implemented");
169 gen->CardTableBarrierSet_post_barrier_helper(addr, card_table_base);
170 #else
171 LIR_Opr tmp = gen->new_pointer_register();
172 if (two_operand_lir_form) {
173 LIR_Opr addr_opr = LIR_OprFact::address(new LIR_Address(addr, addr->type()));
174 __ leal(addr_opr, tmp);
175 __ unsigned_shift_right(tmp, CardTable::card_shift(), tmp);
176 } else {
177 __ unsigned_shift_right(addr, CardTable::card_shift(), tmp);
178 }
179
180 LIR_Address* card_addr;
181 #if INCLUDE_CDS
182 if (AOTCodeCache::is_on_for_dump()) {
183 // load the card table address from the AOT Runtime Constants area
184 LIR_Opr byte_map_base_adr = LIR_OprFact::intptrConst(AOTRuntimeConstants::card_table_base_address());
185 LIR_Opr byte_map_base_reg = gen->new_pointer_register();
186 __ move(byte_map_base_adr, byte_map_base_reg);
187 LIR_Address* byte_map_base_indirect = new LIR_Address(byte_map_base_reg, 0, T_LONG);
188 __ move(byte_map_base_indirect, byte_map_base_reg);
189 card_addr = new LIR_Address(tmp, byte_map_base_reg, T_BYTE);
190 } else
191 #endif
192 if (gen->can_inline_as_constant(card_table_base)) {
193 card_addr = new LIR_Address(tmp, card_table_base->as_jint(), T_BYTE);
194 } else {
195 card_addr = new LIR_Address(tmp, gen->load_constant(card_table_base), T_BYTE);
196 }
197
198 LIR_Opr dirty = LIR_OprFact::intConst(CardTable::dirty_card_val());
199 if (UseCondCardMark) {
200 LIR_Opr cur_value = gen->new_register(T_INT);
201 __ move(card_addr, cur_value);
202
203 LabelObj* L_already_dirty = new LabelObj();
204 __ cmp(lir_cond_equal, cur_value, dirty);
205 __ branch(lir_cond_equal, L_already_dirty->label());
206 __ move(dirty, card_addr);
207 __ branch_destination(L_already_dirty->label());
208 } else {
209 __ move(dirty, card_addr);
210 }
211 #endif
212 }