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 "gc/shared/barrierSetAssembler.hpp"
27 #include "gc/shared/collectedHeap.hpp"
28 #include "runtime/jniHandles.hpp"
29 #include "runtime/thread.hpp"
30
31 #define __ masm->
32
33 void BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
34 Register dst, Address src, Register tmp1, Register tmp_thread) {
35
36 // LR is live. It must be saved around calls.
37
38 bool in_heap = (decorators & IN_HEAP) != 0;
39 bool in_native = (decorators & IN_NATIVE) != 0;
40 bool oop_not_null = (decorators & OOP_NOT_NULL) != 0;
41 switch (type) {
42 case T_OBJECT:
43 case T_ARRAY: {
44 if (in_heap) {
45 if (UseCompressedOops) {
46 __ ldrw(dst, src);
47 if (oop_not_null) {
48 __ decode_heap_oop_not_null(dst);
49 } else {
50 __ decode_heap_oop(dst);
51 }
52 } else {
53 __ ldr(dst, src);
54 }
55 } else {
56 assert(in_native, "why else?");
57 __ ldr(dst, src);
58 }
59 break;
60 }
61 case T_BOOLEAN: __ load_unsigned_byte (dst, src); break;
62 case T_BYTE: __ load_signed_byte (dst, src); break;
63 case T_CHAR: __ load_unsigned_short(dst, src); break;
64 case T_SHORT: __ load_signed_short (dst, src); break;
65 case T_INT: __ ldrw (dst, src); break;
66 case T_LONG: __ ldr (dst, src); break;
67 case T_ADDRESS: __ ldr (dst, src); break;
68 case T_FLOAT: __ ldrs (v0, src); break;
69 case T_DOUBLE: __ ldrd (v0, src); break;
70 default: Unimplemented();
71 }
72 }
73
74 void BarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
75 Address dst, Register val, Register tmp1, Register tmp2) {
76 bool in_heap = (decorators & IN_HEAP) != 0;
77 bool in_native = (decorators & IN_NATIVE) != 0;
78 switch (type) {
79 case T_OBJECT:
80 case T_ARRAY: {
81 val = val == noreg ? zr : val;
82 if (in_heap) {
83 if (UseCompressedOops) {
84 assert(!dst.uses(val), "not enough registers");
85 if (val != zr) {
86 __ encode_heap_oop(val);
87 }
88 __ strw(val, dst);
89 } else {
90 __ str(val, dst);
91 }
92 } else {
93 assert(in_native, "why else?");
94 __ str(val, dst);
95 }
96 break;
97 }
98 case T_BOOLEAN:
99 __ andw(val, val, 0x1); // boolean is true if LSB is 1
100 __ strb(val, dst);
101 break;
102 case T_BYTE: __ strb(val, dst); break;
103 case T_CHAR: __ strh(val, dst); break;
104 case T_SHORT: __ strh(val, dst); break;
105 case T_INT: __ strw(val, dst); break;
106 case T_LONG: __ str (val, dst); break;
107 case T_ADDRESS: __ str (val, dst); break;
108 case T_FLOAT: __ strs(v0, dst); break;
109 case T_DOUBLE: __ strd(v0, dst); break;
110 default: Unimplemented();
111 }
112 }
113
114 void BarrierSetAssembler::obj_equals(MacroAssembler* masm,
115 Register obj1, Register obj2) {
116 __ cmp(obj1, obj2);
117 }
118
119 void BarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env,
120 Register obj, Register tmp, Label& slowpath) {
121 // If mask changes we need to ensure that the inverse is still encodable as an immediate
122 STATIC_ASSERT(JNIHandles::weak_tag_mask == 1);
123 __ andr(obj, obj, ~JNIHandles::weak_tag_mask);
124 __ ldr(obj, Address(obj, 0)); // *obj
125 }
126
127 // Defines obj, preserves var_size_in_bytes, okay for t2 == var_size_in_bytes.
128 void BarrierSetAssembler::tlab_allocate(MacroAssembler* masm, Register obj,
129 Register var_size_in_bytes,
130 int con_size_in_bytes,
131 Register t1,
132 Register t2,
133 Label& slow_case) {
134 assert_different_registers(obj, t2);
135 assert_different_registers(obj, var_size_in_bytes);
136 Register end = t2;
137
138 // verify_tlab();
139
140 __ ldr(obj, Address(rthread, JavaThread::tlab_top_offset()));
141 if (var_size_in_bytes == noreg) {
142 __ lea(end, Address(obj, con_size_in_bytes));
143 } else {
144 __ lea(end, Address(obj, var_size_in_bytes));
145 }
146 __ ldr(rscratch1, Address(rthread, JavaThread::tlab_end_offset()));
147 __ cmp(end, rscratch1);
148 __ br(Assembler::HI, slow_case);
149
150 // update the tlab top pointer
151 __ str(end, Address(rthread, JavaThread::tlab_top_offset()));
152
153 // recover var_size_in_bytes if necessary
154 if (var_size_in_bytes == end) {
155 __ sub(var_size_in_bytes, var_size_in_bytes, obj);
156 }
157 // verify_tlab();
158 }
159
160 // Defines obj, preserves var_size_in_bytes
161 void BarrierSetAssembler::eden_allocate(MacroAssembler* masm, Register obj,
162 Register var_size_in_bytes,
163 int con_size_in_bytes,
164 Register t1,
165 Label& slow_case) {
166 assert_different_registers(obj, var_size_in_bytes, t1);
167 if (!Universe::heap()->supports_inline_contig_alloc()) {
168 __ b(slow_case);
169 } else {
170 Register end = t1;
171 Register heap_end = rscratch2;
172 Label retry;
173 __ bind(retry);
174 {
175 unsigned long offset;
176 __ adrp(rscratch1, ExternalAddress((address) Universe::heap()->end_addr()), offset);
177 __ ldr(heap_end, Address(rscratch1, offset));
178 }
179
180 ExternalAddress heap_top((address) Universe::heap()->top_addr());
181
182 // Get the current top of the heap
183 {
184 unsigned long offset;
185 __ adrp(rscratch1, heap_top, offset);
186 // Use add() here after ARDP, rather than lea().
187 // lea() does not generate anything if its offset is zero.
188 // However, relocs expect to find either an ADD or a load/store
189 // insn after an ADRP. add() always generates an ADD insn, even
190 // for add(Rn, Rn, 0).
191 __ add(rscratch1, rscratch1, offset);
192 __ ldaxr(obj, rscratch1);
193 }
194
195 // Adjust it my the size of our new object
196 if (var_size_in_bytes == noreg) {
197 __ lea(end, Address(obj, con_size_in_bytes));
198 } else {
199 __ lea(end, Address(obj, var_size_in_bytes));
200 }
201
202 // if end < obj then we wrapped around high memory
203 __ cmp(end, obj);
204 __ br(Assembler::LO, slow_case);
205
206 __ cmp(end, heap_end);
207 __ br(Assembler::HI, slow_case);
208
209 // If heap_top hasn't been changed by some other thread, update it.
210 __ stlxr(rscratch2, end, rscratch1);
211 __ cbnzw(rscratch2, retry);
212
213 incr_allocated_bytes(masm, var_size_in_bytes, con_size_in_bytes, t1);
214 }
215 }
216
217 void BarrierSetAssembler::incr_allocated_bytes(MacroAssembler* masm,
218 Register var_size_in_bytes,
219 int con_size_in_bytes,
220 Register t1) {
221 assert(t1->is_valid(), "need temp reg");
222
223 __ ldr(t1, Address(rthread, in_bytes(JavaThread::allocated_bytes_offset())));
224 if (var_size_in_bytes->is_valid()) {
225 __ add(t1, t1, var_size_in_bytes);
226 } else {
227 __ add(t1, t1, con_size_in_bytes);
228 }
229 __ str(t1, Address(rthread, in_bytes(JavaThread::allocated_bytes_offset())));
230 }
231