1 /*
2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
3  * Copyright (c) 2018, SAP SE. All rights reserved.
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This code is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 only, as
8  * published by the Free Software Foundation.
9  *
10  * This code is distributed in the hope that it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13  * version 2 for more details (a copy is included in the LICENSE file that
14  * accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License version
17  * 2 along with this work; if not, write to the Free Software Foundation,
18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19  *
20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21  * or visit www.oracle.com if you need additional information or have any
22  * questions.
23  *
24  */
25 
26 #include "precompiled.hpp"
27 #include "asm/macroAssembler.inline.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 "interpreter/interp_masm.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 
gen_write_ref_array_post_barrier(MacroAssembler * masm,DecoratorSet decorators,Register addr,Register count,Register preserve)44 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, Register addr,
45                                                                     Register count, Register preserve) {
46   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
47   CardTable* ct = ctbs->card_table();
48   assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
49   assert_different_registers(addr, count, R0);
50 
51   Label Lskip_loop, Lstore_loop;
52 
53   if (ct->scanned_concurrently()) { __ membar(Assembler::StoreStore); }
54 
55   __ sldi_(count, count, LogBytesPerHeapOop);
56   __ beq(CCR0, Lskip_loop); // zero length
57   __ addi(count, count, -BytesPerHeapOop);
58   __ add(count, addr, count);
59   // Use two shifts to clear out those low order two bits! (Cannot opt. into 1.)
60   __ srdi(addr, addr, CardTable::card_shift);
61   __ srdi(count, count, CardTable::card_shift);
62   __ subf(count, addr, count);
63   __ add_const_optimized(addr, addr, (address)ct->byte_map_base(), R0);
64   __ addi(count, count, 1);
65   __ li(R0, 0);
66   __ mtctr(count);
67   // Byte store loop
68   __ bind(Lstore_loop);
69   __ stb(R0, 0, addr);
70   __ addi(addr, addr, 1);
71   __ bdnz(Lstore_loop);
72   __ bind(Lskip_loop);
73 }
74 
card_table_write(MacroAssembler * masm,jbyte * byte_map_base,Register tmp,Register obj)75 void CardTableBarrierSetAssembler::card_table_write(MacroAssembler* masm,
76                                                     jbyte* byte_map_base,
77                                                     Register tmp, Register obj) {
78   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
79   CardTable* ct = ctbs->card_table();
80   assert_different_registers(obj, tmp, R0);
81   __ load_const_optimized(tmp, (address)byte_map_base, R0);
82   __ srdi(obj, obj, CardTable::card_shift);
83   __ li(R0, CardTable::dirty_card_val());
84   if (ct->scanned_concurrently()) { __ membar(Assembler::StoreStore); }
85   __ stbx(R0, tmp, obj);
86 }
87 
card_write_barrier_post(MacroAssembler * masm,Register store_addr,Register tmp)88 void CardTableBarrierSetAssembler::card_write_barrier_post(MacroAssembler* masm, Register store_addr, Register tmp) {
89   CardTableBarrierSet* bs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
90   card_table_write(masm, bs->card_table()->byte_map_base(), tmp, store_addr);
91 }
92 
oop_store_at(MacroAssembler * masm,DecoratorSet decorators,BasicType type,Register base,RegisterOrConstant ind_or_offs,Register val,Register tmp1,Register tmp2,Register tmp3,bool needs_frame)93 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
94                                                 Register base, RegisterOrConstant ind_or_offs, Register val,
95                                                 Register tmp1, Register tmp2, Register tmp3, bool needs_frame) {
96   bool is_array = (decorators & IS_ARRAY) != 0;
97   bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
98   bool precise = is_array || on_anonymous;
99 
100   BarrierSetAssembler::store_at(masm, decorators, type, base, ind_or_offs, val, tmp1, tmp2, tmp3, needs_frame);
101 
102   // No need for post barrier if storing NULL
103   if (val != noreg) {
104     if (precise) {
105       if (ind_or_offs.is_constant()) {
106         __ add_const_optimized(base, base, ind_or_offs.as_constant(), tmp1);
107       } else {
108         __ add(base, ind_or_offs.as_register(), base);
109       }
110     }
111     card_write_barrier_post(masm, base, tmp1);
112   }
113 }
114