1 /*
2 * Copyright (c) 2018, 2021, 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 "asm/macroAssembler.inline.hpp"
27 #include "code/SCCache.hpp"
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/cardTable.hpp"
30 #include "gc/shared/cardTableBarrierSet.hpp"
31 #include "gc/shared/cardTableBarrierSetAssembler.hpp"
32 #include "gc/shared/gc_globals.hpp"
33
34 #define __ masm->
35
36 #ifdef PRODUCT
37 #define BLOCK_COMMENT(str) /* nothing */
38 #else
39 #define BLOCK_COMMENT(str) __ block_comment(str)
40 #endif
41
42 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
43
44 #define TIMES_OOP (UseCompressedOops ? Address::times_4 : Address::times_8)
45
46 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
47 Register addr, Register count, Register tmp) {
48 BarrierSet *bs = BarrierSet::barrier_set();
49 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
50 CardTable* ct = ctbs->card_table();
51 intptr_t byte_map_base = (intptr_t) ct->byte_map_base();
52
53 Label L_loop, L_done;
54 const Register end = count;
55 assert_different_registers(addr, end);
56
57 __ testl(count, count);
58 __ jcc(Assembler::zero, L_done); // zero count - nothing to do
59
60
61 #ifdef _LP64
62 __ leaq(end, Address(addr, count, TIMES_OOP, 0)); // end == addr+count*oop_size
63 __ subptr(end, BytesPerHeapOop); // end - 1 to make inclusive
64 __ shrptr(addr, CardTable::card_shift());
65 __ shrptr(end, CardTable::card_shift());
66 __ subptr(end, addr); // end --> cards count
67
68 if (SCCache::is_on_for_write()) {
69 // SCA needs relocation info for this address
70 __ lea(tmp, ExternalAddress((address)byte_map_base));
71 } else {
72 __ mov64(tmp, byte_map_base);
73 }
74 __ addptr(addr, tmp);
75 __ BIND(L_loop);
76 __ movb(Address(addr, count, Address::times_1), 0);
77 __ decrement(count);
78 __ jcc(Assembler::greaterEqual, L_loop);
79 #else
80 __ lea(end, Address(addr, count, Address::times_ptr, -wordSize));
81 __ shrptr(addr, CardTable::card_shift());
82 __ shrptr(end, CardTable::card_shift());
83 __ subptr(end, addr); // end --> count
84 __ BIND(L_loop);
85 Address cardtable(addr, count, Address::times_1, byte_map_base);
86 __ movb(cardtable, 0);
87 __ decrement(count);
88 __ jcc(Assembler::greaterEqual, L_loop);
89 #endif
90
91 __ BIND(L_done);
92 }
93
94 void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register obj, Address dst) {
95 // Does a store check for the oop in register obj. The content of
96 // register obj is destroyed afterwards.
97 BarrierSet* bs = BarrierSet::barrier_set();
98
99 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
100 CardTable* ct = ctbs->card_table();
101
102 __ shrptr(obj, CardTable::card_shift());
103
104 Address card_addr;
105
106 // The calculation for byte_map_base is as follows:
107 // byte_map_base = _byte_map - (uintptr_t(low_bound) >> card_shift);
108 // So this essentially converts an address to a displacement and it will
109 // never need to be relocated. On 64bit however the value may be too
110 // large for a 32bit displacement.
111 intptr_t byte_map_base = (intptr_t)ct->byte_map_base();
112 if (SCCache::is_on_for_write()) {
113 // SCA needs relocation info for this address
114 ExternalAddress cardtable((address)byte_map_base);
115 Address index(noreg, obj, Address::times_1);
116 card_addr = __ as_Address(ArrayAddress(cardtable, index), rscratch1);
117 } else
118 if (__ is_simm32(byte_map_base)) {
119 card_addr = Address(noreg, obj, Address::times_1, byte_map_base);
120 } else {
121 // By doing it as an ExternalAddress 'byte_map_base' could be converted to a rip-relative
122 // displacement and done in a single instruction given favorable mapping and a
123 // smarter version of as_Address. However, 'ExternalAddress' generates a relocation
124 // entry and that entry is not properly handled by the relocation code.
125 AddressLiteral cardtable((address)byte_map_base, relocInfo::none);
126 Address index(noreg, obj, Address::times_1);
127 card_addr = __ as_Address(ArrayAddress(cardtable, index), rscratch1);
128 }
129
130 int dirty = CardTable::dirty_card_val();
131 if (UseCondCardMark) {
132 Label L_already_dirty;
133 __ cmpb(card_addr, dirty);
134 __ jccb(Assembler::equal, L_already_dirty);
135 __ movb(card_addr, dirty);
136 __ bind(L_already_dirty);
137 } else {
138 __ movb(card_addr, dirty);
139 }
140 }
141
142 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
143 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
144 bool in_heap = (decorators & IN_HEAP) != 0;
145
146 bool is_array = (decorators & IS_ARRAY) != 0;
147 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
148 bool precise = is_array || on_anonymous;
149
150 bool needs_post_barrier = val != noreg && in_heap;
151
152 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, noreg, noreg, noreg);
153 if (needs_post_barrier) {
154 // flatten object address if needed
155 if (!precise || (dst.index() == noreg && dst.disp() == 0)) {
156 store_check(masm, dst.base(), dst);
157 } else {
158 __ lea(tmp1, dst);
159 store_check(masm, tmp1, dst);
160 }
161 }
162 }