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 "asm/macroAssembler.inline.hpp"
26 #include "code/aotCodeCache.hpp"
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shared/cardTable.hpp"
29 #include "gc/shared/cardTableBarrierSet.hpp"
30 #include "gc/shared/cardTableBarrierSetAssembler.hpp"
31 #include "gc/shared/gc_globals.hpp"
32
33 #define __ masm->
34
35 #ifdef PRODUCT
36 #define BLOCK_COMMENT(str) /* nothing */
37 #else
38 #define BLOCK_COMMENT(str) __ block_comment(str)
39 #endif
40
41 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
42
43 #define TIMES_OOP (UseCompressedOops ? Address::times_4 : Address::times_8)
44
45 void CardTableBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
46 Register src, Register dst, Register count) {
47 bool checkcast = (decorators & ARRAYCOPY_CHECKCAST) != 0;
48 bool disjoint = (decorators & ARRAYCOPY_DISJOINT) != 0;
49 bool obj_int = (type == T_OBJECT) && UseCompressedOops;
50
51 if (is_reference_type(type)) {
52 if (!checkcast) {
53 if (!obj_int) {
54 // Save count for barrier
55 __ movptr(r11, count);
56 } else if (disjoint) {
57 // Save dst in r11 in the disjoint case
58 __ movq(r11, dst);
59 }
60 }
61 gen_write_ref_array_pre_barrier(masm, decorators, dst, count);
62 }
63 }
64
65 void CardTableBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
66 Register src, Register dst, Register count) {
67 bool checkcast = (decorators & ARRAYCOPY_CHECKCAST) != 0;
68 bool disjoint = (decorators & ARRAYCOPY_DISJOINT) != 0;
69 bool obj_int = (type == T_OBJECT) && UseCompressedOops;
70 Register tmp = rax;
71
72 if (is_reference_type(type)) {
73 if (!checkcast) {
74 if (!obj_int) {
75 // Save count for barrier
76 count = r11;
77 } else if (disjoint) {
78 // Use the saved dst in the disjoint case
79 dst = r11;
80 }
81 } else {
82 tmp = rscratch1;
83 }
84 gen_write_ref_array_post_barrier(masm, decorators, dst, count, tmp);
85 }
86 }
87
88 void CardTableBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
89 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
90 if (is_reference_type(type)) {
91 oop_store_at(masm, decorators, type, dst, val, tmp1, tmp2, tmp3);
92 } else {
93 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2, tmp3);
94 }
95 }
96
97 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
98 Register addr, Register count, Register tmp) {
99 BarrierSet *bs = BarrierSet::barrier_set();
100 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
101 CardTable* ct = ctbs->card_table();
102 intptr_t byte_map_base = (intptr_t) ct->byte_map_base();
103 SHENANDOAHGC_ONLY(assert(!UseShenandoahGC, "Shenandoah byte_map_base is not constant.");)
104
105 Label L_loop, L_done;
106 const Register end = count;
107 assert_different_registers(addr, end);
108
109 __ testl(count, count);
110 __ jcc(Assembler::zero, L_done); // zero count - nothing to do
111
112
113 __ leaq(end, Address(addr, count, TIMES_OOP, 0)); // end == addr+count*oop_size
114 __ subptr(end, BytesPerHeapOop); // end - 1 to make inclusive
115 __ shrptr(addr, CardTable::card_shift());
116 __ shrptr(end, CardTable::card_shift());
117 __ subptr(end, addr); // end --> cards count
118
119 #if INCLUDE_CDS
120 if (AOTCodeCache::is_on_for_dump()) {
121 __ movptr(tmp, ExternalAddress(AOTRuntimeConstants::card_table_address()));
122 } else
123 #endif
124 {
125 __ mov64(tmp, byte_map_base);
126 }
127 __ addptr(addr, tmp);
128 __ BIND(L_loop);
129 __ movb(Address(addr, count, Address::times_1), 0);
130 __ decrement(count);
131 __ jcc(Assembler::greaterEqual, L_loop);
132
133 __ BIND(L_done);
134 }
135
136 void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register obj, Address dst, Register rscratch) {
137 // Does a store check for the oop in register obj. The content of
138 // register obj is destroyed afterwards.
139 BarrierSet* bs = BarrierSet::barrier_set();
140
141 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
142 CardTable* ct = ctbs->card_table();
143
144 __ shrptr(obj, CardTable::card_shift());
145
146 Address card_addr;
147 precond(rscratch != noreg);
148
149 // The calculation for byte_map_base is as follows:
150 // byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
151 // So this essentially converts an address to a displacement and it will
152 // never need to be relocated. On 64bit however the value may be too
153 // large for a 32bit displacement.
154 intptr_t byte_map_base = (intptr_t)ct->byte_map_base();
155 #if INCLUDE_CDS
156 if (AOTCodeCache::is_on_for_dump()) {
157 __ movptr(rscratch, ExternalAddress(AOTRuntimeConstants::card_table_address()));
158 card_addr = Address(rscratch, obj, Address::times_1, 0);
159 } else
160 #endif
161 if (__ is_simm32(byte_map_base)) {
162 card_addr = Address(noreg, obj, Address::times_1, byte_map_base);
163 } else {
164 // By doing it as an ExternalAddress 'byte_map_base' could be converted to a rip-relative
165 // displacement and done in a single instruction given favorable mapping and a
166 // smarter version of as_Address. However, 'ExternalAddress' generates a relocation
167 // entry and that entry is not properly handled by the relocation code.
168 AddressLiteral cardtable((address)byte_map_base, relocInfo::none);
169 Address index(noreg, obj, Address::times_1);
170 card_addr = __ as_Address(ArrayAddress(cardtable, index), rscratch);
171 }
172
173 int dirty = CardTable::dirty_card_val();
174 if (UseCondCardMark) {
175 Label L_already_dirty;
176 __ cmpb(card_addr, dirty);
177 __ jccb(Assembler::equal, L_already_dirty);
178 __ movb(card_addr, dirty);
179 __ bind(L_already_dirty);
180 } else {
181 __ movb(card_addr, dirty);
182 }
183 }
184
185 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
186 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
187 bool in_heap = (decorators & IN_HEAP) != 0;
188
189 bool is_array = (decorators & IS_ARRAY) != 0;
190 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
191 bool precise = is_array || on_anonymous;
192
193 bool needs_post_barrier = val != noreg && in_heap;
194
195 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, noreg, noreg, noreg);
196 if (needs_post_barrier) {
197 // flatten object address if needed
198 if (!precise || (dst.index() == noreg && dst.disp() == 0)) {
199 store_check(masm, dst.base(), dst, tmp2);
200 } else {
201 __ lea(tmp1, dst);
202 store_check(masm, tmp1, dst, tmp2);
203 }
204 }
205 }