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 "gc/shared/collectedHeap.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::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
46 Register addr, Register count, Register tmp) {
47 BarrierSet *bs = Universe::heap()->barrier_set();
48 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
49 CardTable* ct = ctbs->card_table();
50 assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
51 intptr_t disp = (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 __ mov64(tmp, disp);
69 __ addptr(addr, tmp);
70 __ BIND(L_loop);
71 __ movb(Address(addr, count, Address::times_1), 0);
72 __ decrement(count);
73 __ jcc(Assembler::greaterEqual, L_loop);
74 #else
75 __ lea(end, Address(addr, count, Address::times_ptr, -wordSize));
76 __ shrptr(addr, CardTable::card_shift);
77 __ shrptr(end, CardTable::card_shift);
78 __ subptr(end, addr); // end --> count
79 __ BIND(L_loop);
80 Address cardtable(addr, count, Address::times_1, disp);
81 __ movb(cardtable, 0);
82 __ decrement(count);
83 __ jcc(Assembler::greaterEqual, L_loop);
84 #endif
85
86 __ BIND(L_done);
87 }