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 #include "runtime/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 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
45 Register addr, Register count, Register tmp) {
46 BLOCK_COMMENT("CardTablePostBarrier");
47 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
48 CardTable* ct = ctbs->card_table();
49 assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
50
51 Label L_cardtable_loop, L_done;
52
53 __ cbz_32(count, L_done); // zero count - nothing to do
54
55 __ add_ptr_scaled_int32(count, addr, count, LogBytesPerHeapOop);
56 __ sub(count, count, BytesPerHeapOop); // last addr
57
58 __ logical_shift_right(addr, addr, CardTable::card_shift);
59 __ logical_shift_right(count, count, CardTable::card_shift);
60 __ sub(count, count, addr); // nb of cards
61
62 // warning: Rthread has not been preserved
63 __ mov_address(tmp, (address) ct->byte_map_base(), symbolic_Relocation::card_table_reference);
64 __ add(addr,tmp, addr);
65
66 Register zero = __ zero_register(tmp);
67
68 __ BIND(L_cardtable_loop);
69 __ strb(zero, Address(addr, 1, post_indexed));
70 __ subs(count, count, 1);
71 __ b(L_cardtable_loop, ge);
72 __ BIND(L_done);
73 }