1 /*
2 * Copyright (c) 2018, 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 "interpreter/interp_masm.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
gen_write_ref_array_post_barrier(MacroAssembler * masm,DecoratorSet decorators,Register addr,Register count,Register tmp)43 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
44 Register addr, Register count, Register tmp) {
45 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
46 CardTable* ct = ctbs->card_table();
47 assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
48 assert_different_registers(addr, count, tmp);
49
50 Label L_loop, L_done;
51
52 __ cmp_and_br_short(count, 0, Assembler::equal, Assembler::pt, L_done); // zero count - nothing to do
53
54 __ sll_ptr(count, LogBytesPerHeapOop, count);
55 __ sub(count, BytesPerHeapOop, count);
56 __ add(count, addr, count);
57 // Use two shifts to clear out those low order two bits! (Cannot opt. into 1.)
58 __ srl_ptr(addr, CardTable::card_shift, addr);
59 __ srl_ptr(count, CardTable::card_shift, count);
60 __ sub(count, addr, count);
61 AddressLiteral rs(ct->byte_map_base());
62 __ set(rs, tmp);
63 __ BIND(L_loop);
64 __ stb(G0, tmp, addr);
65 __ subcc(count, 1, count);
66 __ brx(Assembler::greaterEqual, false, Assembler::pt, L_loop);
67 __ delayed()->add(addr, 1, addr);
68
69 __ BIND(L_done);
70 }
71
card_table_write(MacroAssembler * masm,jbyte * byte_map_base,Register tmp,Register obj)72 void CardTableBarrierSetAssembler::card_table_write(MacroAssembler* masm,
73 jbyte* byte_map_base,
74 Register tmp, Register obj) {
75 __ srlx(obj, CardTable::card_shift, obj);
76 assert(tmp != obj, "need separate temp reg");
77 __ set((address) byte_map_base, tmp);
78 __ stb(G0, tmp, obj);
79 }
80
card_write_barrier_post(MacroAssembler * masm,Register store_addr,Register new_val,Register tmp)81 void CardTableBarrierSetAssembler::card_write_barrier_post(MacroAssembler* masm, Register store_addr, Register new_val, Register tmp) {
82 // If we're writing constant NULL, we can skip the write barrier.
83 if (new_val == G0) return;
84 CardTableBarrierSet* bs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
85 card_table_write(masm, bs->card_table()->byte_map_base(), tmp, store_addr);
86 }
87
oop_store_at(MacroAssembler * masm,DecoratorSet decorators,BasicType type,Register val,Address dst,Register tmp)88 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
89 Register val, Address dst, Register tmp) {
90 bool in_heap = (decorators & IN_HEAP) != 0;
91
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
96 // No need for post barrier if storing NULL
97 bool needs_post_barrier = val != G0 && in_heap;
98
99 BarrierSetAssembler::store_at(masm, decorators, type, val, dst, tmp);
100 if (needs_post_barrier) {
101 Register base = dst.base();
102 if (precise) {
103 if (!dst.has_index()) {
104 __ add(base, dst.disp(), base);
105 } else {
106 assert(!dst.has_disp(), "not supported yet");
107 __ add(base, dst.index(), base);
108 }
109 }
110 card_write_barrier_post(masm, base, val, tmp);
111 }
112 }
113