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
44 #define TIMES_OOP (UseCompressedOops ? Address::times_4 : Address::times_8)
45
46 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, Register addr, Register count,
47 bool do_return) {
48 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
49 CardTable* ct = ctbs->card_table();
50 assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
51
52 NearLabel doXC, done;
53 assert_different_registers(Z_R0, Z_R1, addr, count);
54
55 // Nothing to do if count <= 0.
56 if (!do_return) {
57 __ compare64_and_branch(count, (intptr_t) 0, Assembler::bcondNotHigh, done);
58 } else {
59 __ z_ltgr(count, count);
60 __ z_bcr(Assembler::bcondNotPositive, Z_R14);
61 }
62
63 // Note: We can't combine the shifts. We could lose a carry
64 // from calculating the array end address.
65 // count = (count-1)*BytesPerHeapOop + addr
66 // Count holds addr of last oop in array then.
67 __ z_sllg(count, count, LogBytesPerHeapOop);
68 __ add2reg_with_index(count, -BytesPerHeapOop, count, addr);
69
70 // Get base address of card table.
71 __ load_const_optimized(Z_R1, (address)ct->byte_map_base());
72
73 // count = (count>>shift) - (addr>>shift)
74 __ z_srlg(addr, addr, CardTable::card_shift);
75 __ z_srlg(count, count, CardTable::card_shift);
76
77 // Prefetch first elements of card table for update.
78 if (VM_Version::has_Prefetch()) {
79 __ z_pfd(0x02, 0, addr, Z_R1);
80 }
81
82 // Special case: clear just one byte.
83 __ clear_reg(Z_R0, true, false); // Used for doOneByte.
84 __ z_sgr(count, addr); // Count = n-1 now, CC used for brc below.
85 __ z_stc(Z_R0, 0, addr, Z_R1); // Must preserve CC from z_sgr.
86 if (!do_return) {
87 __ z_brz(done);
88 } else {
89 __ z_bcr(Assembler::bcondZero, Z_R14);
90 }
91
92 __ z_cghi(count, 255);
93 __ z_brnh(doXC);
94
95 // MVCLE: clear a long area.
96 // Start addr of card table range = base + addr.
97 // # bytes in card table range = (count + 1)
98 __ add2reg_with_index(Z_R0, 0, Z_R1, addr);
99 __ add2reg(Z_R1, 1, count);
100
101 // dirty hack:
102 // There are just two callers. Both pass
103 // count in Z_ARG3 = Z_R4
104 // addr in Z_ARG2 = Z_R3
105 // ==> use Z_ARG2 as src len reg = 0
106 // Z_ARG1 as src addr (ignored)
107 assert(count == Z_ARG3, "count: unexpected register number");
108 assert(addr == Z_ARG2, "addr: unexpected register number");
109 __ clear_reg(Z_ARG2, true, false);
110
111 __ MacroAssembler::move_long_ext(Z_R0, Z_ARG1, 0);
112
113 if (!do_return) {
114 __ z_bru(done);
115 } else {
116 __ z_bcr(Assembler::bcondAlways, Z_R14);
117 }
118
119 // XC: clear a short area.
120 Label XC_template; // Instr template, never exec directly!
121 __ bind(XC_template);
122 __ z_xc(0, 0, addr, 0, addr);
123
124 __ bind(doXC);
125 // start addr of card table range = base + addr
126 // end addr of card table range = base + addr + count
127 __ add2reg_with_index(addr, 0, Z_R1, addr);
128
129 if (VM_Version::has_ExecuteExtensions()) {
130 __ z_exrl(count, XC_template); // Execute XC with var. len.
131 } else {
132 __ z_larl(Z_R1, XC_template);
133 __ z_ex(count, 0, Z_R0, Z_R1); // Execute XC with var. len.
134 }
135 if (do_return) {
136 __ z_br(Z_R14);
137 }
138
139 __ bind(done);
140 }
141
142 void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register store_addr, Register tmp) {
143 // Does a store check for the oop in register obj. The content of
144 // register obj is destroyed afterwards.
145 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());
146 CardTable* ct = ctbs->card_table();
147 assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
148
149 assert_different_registers(store_addr, tmp);
150
151 __ z_srlg(store_addr, store_addr, CardTable::card_shift);
152 __ load_absolute_address(tmp, (address)ct->byte_map_base());
153 __ z_agr(store_addr, tmp);
154 __ z_mvi(0, store_addr, CardTable::dirty_card_val());
155 }
156
157 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
158 const Address& dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
159 bool on_array = (decorators & IN_HEAP_ARRAY) != 0;
160 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
161 bool precise = on_array || on_anonymous;
162
163 BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2, tmp3);
164
165 // No need for post barrier if storing NULL
166 if (val != noreg) {
167 const Register base = dst.base(),
168 idx = dst.index();
169 const intptr_t disp = dst.disp();
170 if (precise && (disp != 0 || idx != noreg)) {
171 __ add2reg_with_index(base, disp, idx, base);
172 }
173 store_check(masm, base, tmp1);
174 }
175 }