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 "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 #include "interpreter/interp_masm.hpp"
33
34 #define __ masm->
35
36 void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register obj, Address dst) {
37
38 BarrierSet* bs = BarrierSet::barrier_set();
39 assert(bs->kind() == BarrierSet::CardTableBarrierSet, "Wrong barrier set kind");
40
41 __ lsr(obj, obj, CardTable::card_shift());
42
43 assert(CardTable::dirty_card_val() == 0, "must be");
44
45 __ load_byte_map_base(rscratch1);
46
47 if (UseCondCardMark) {
48 Label L_already_dirty;
49 __ ldrb(rscratch2, Address(obj, rscratch1));
50 __ cbz(rscratch2, L_already_dirty);
51 __ strb(zr, Address(obj, rscratch1));
52 __ bind(L_already_dirty);
53 } else {
54 __ strb(zr, Address(obj, rscratch1));
55 }
56 }
57
58 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
59 Register start, Register count, Register scratch, RegSet saved_regs) {
60 Label L_loop, L_done;
61 const Register end = count;
62
63 __ cbz(count, L_done); // zero count - nothing to do
64
65 __ lea(end, Address(start, count, Address::lsl(LogBytesPerHeapOop))); // end = start + count << LogBytesPerHeapOop
66 __ sub(end, end, BytesPerHeapOop); // last element address to make inclusive
67 __ lsr(start, start, CardTable::card_shift());
68 __ lsr(end, end, CardTable::card_shift());
69 __ sub(count, end, start); // number of bytes to copy
70
71 __ load_byte_map_base(scratch);
72 __ add(start, start, scratch);
73 __ bind(L_loop);
74 __ strb(zr, Address(start, count));
75 __ subs(count, count, 1);
76 __ br(Assembler::GE, L_loop);
77 __ bind(L_done);
78 }
79
80 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
81 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
82 bool in_heap = (decorators & IN_HEAP) != 0;
83 bool is_array = (decorators & IS_ARRAY) != 0;
84 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
85 bool precise = is_array || on_anonymous;
86
87 bool needs_post_barrier = val != noreg && in_heap;
88 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, noreg, noreg, noreg);
89 if (needs_post_barrier) {
90 // flatten object address if needed
91 if (!precise || (dst.index() == noreg && dst.offset() == 0)) {
92 store_check(masm, dst.base(), dst);
93 } else {
94 __ lea(tmp3, dst);
95 store_check(masm, tmp3, dst);
96 }
97 }
98 }