1 /*
2 * Copyright (c) 2004, 2019, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2014, Red Hat Inc. 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.hpp"
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/barrierSetAssembler.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "prims/jniFastGetField.hpp"
32 #include "prims/jvm_misc.hpp"
33 #include "runtime/safepoint.hpp"
34
35 #define __ masm->
36
37 #define BUFFER_SIZE 30*wordSize
38
39 // Instead of issuing a LoadLoad barrier we create an address
40 // dependency between loads; this might be more efficient.
41
42 // Common register usage:
43 // r0/v0: result
44 // c_rarg0: jni env
45 // c_rarg1: obj
46 // c_rarg2: jfield id
47
48 static const Register robj = r3;
49 static const Register rcounter = r4;
50 static const Register roffset = r5;
51 static const Register rcounter_addr = r6;
52 static const Register result = r7;
53
54 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
55 const char *name;
56 switch (type) {
57 case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
58 case T_BYTE: name = "jni_fast_GetByteField"; break;
59 case T_CHAR: name = "jni_fast_GetCharField"; break;
60 case T_SHORT: name = "jni_fast_GetShortField"; break;
61 case T_INT: name = "jni_fast_GetIntField"; break;
62 case T_LONG: name = "jni_fast_GetLongField"; break;
63 case T_FLOAT: name = "jni_fast_GetFloatField"; break;
64 case T_DOUBLE: name = "jni_fast_GetDoubleField"; break;
65 default: ShouldNotReachHere();
66 name = NULL; // unreachable
67 }
68 ResourceMark rm;
69 BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
70 CodeBuffer cbuf(blob);
71 MacroAssembler* masm = new MacroAssembler(&cbuf);
72 address fast_entry = __ pc();
73
74 Label slow;
75
76 unsigned long offset;
77 __ adrp(rcounter_addr,
78 SafepointSynchronize::safepoint_counter_addr(), offset);
79 Address safepoint_counter_addr(rcounter_addr, offset);
80 __ ldrw(rcounter, safepoint_counter_addr);
81 __ tbnz(rcounter, 0, slow);
82
83 if (!UseBarriersForVolatile) {
84 // Field may be volatile. See other usages of this flag.
85 __ membar(MacroAssembler::AnyAny);
86 __ mov(robj, c_rarg1);
87 } else if (JvmtiExport::can_post_field_access()) {
88 // Using barrier to order wrt. JVMTI check and load of result.
89 __ membar(Assembler::LoadLoad);
90 __ mov(robj, c_rarg1);
91 } else {
92 // Using address dependency to order wrt. load of result.
93 __ eor(robj, c_rarg1, rcounter);
94 __ eor(robj, robj, rcounter); // obj, since
95 // robj ^ rcounter ^ rcounter == robj
96 // robj is address dependent on rcounter.
97 }
98
99 if (JvmtiExport::can_post_field_access()) {
100 // Check to see if a field access watch has been set before we
101 // take the fast path.
102 unsigned long offset2;
103 __ adrp(result,
104 ExternalAddress((address) JvmtiExport::get_field_access_count_addr()),
105 offset2);
106 __ ldrw(result, Address(result, offset2));
107 __ cbnzw(result, slow);
108 }
109
110 // Both robj and rscratch1 are clobbered by try_resolve_jobject_in_native.
111 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
112 bs->try_resolve_jobject_in_native(masm, c_rarg0, robj, rscratch1, slow);
113
114 __ lsr(roffset, c_rarg2, 2); // offset
115 __ add(result, robj, roffset);
116
117 assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
118 speculative_load_pclist[count] = __ pc(); // Used by the segfault handler
119 // Using acquire: Order JVMTI check and load of result wrt. succeeding check
120 // (LoadStore for volatile field).
121 switch (type) {
122 case T_BOOLEAN: __ ldarb(result, result); break;
123 case T_BYTE: __ ldarb(result, result); __ sxtb(result, result); break;
124 case T_CHAR: __ ldarh(result, result); break;
125 case T_SHORT: __ ldarh(result, result); __ sxth(result, result); break;
126 case T_FLOAT: __ ldarw(result, result); break;
127 case T_INT: __ ldarw(result, result); __ sxtw(result, result); break;
128 case T_DOUBLE:
129 case T_LONG: __ ldar (result, result); break;
130 default: ShouldNotReachHere();
131 }
132
133 __ ldrw(rscratch1, safepoint_counter_addr);
134 __ cmpw(rcounter, rscratch1);
135 __ br (Assembler::NE, slow);
136
137 switch (type) {
138 case T_FLOAT: __ fmovs(v0, result); break;
139 case T_DOUBLE: __ fmovd(v0, result); break;
140 default: __ mov(r0, result); break;
141 }
142 __ ret(lr);
143
144 slowcase_entry_pclist[count++] = __ pc();
145 __ bind(slow);
146 address slow_case_addr;
147 switch (type) {
148 case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
149 case T_BYTE: slow_case_addr = jni_GetByteField_addr(); break;
150 case T_CHAR: slow_case_addr = jni_GetCharField_addr(); break;
151 case T_SHORT: slow_case_addr = jni_GetShortField_addr(); break;
152 case T_INT: slow_case_addr = jni_GetIntField_addr(); break;
153 case T_LONG: slow_case_addr = jni_GetLongField_addr(); break;
154 case T_FLOAT: slow_case_addr = jni_GetFloatField_addr(); break;
155 case T_DOUBLE: slow_case_addr = jni_GetDoubleField_addr(); break;
156 default: ShouldNotReachHere();
157 slow_case_addr = NULL; // unreachable
158 }
159
160 {
161 __ enter();
162 __ lea(rscratch1, ExternalAddress(slow_case_addr));
163 __ blr(rscratch1);
164 __ maybe_isb();
165 __ leave();
166 __ ret(lr);
167 }
168 __ flush ();
169
170 return fast_entry;
171 }
172
173 address JNI_FastGetField::generate_fast_get_boolean_field() {
174 return generate_fast_get_int_field0(T_BOOLEAN);
175 }
176
177 address JNI_FastGetField::generate_fast_get_byte_field() {
178 return generate_fast_get_int_field0(T_BYTE);
179 }
180
181 address JNI_FastGetField::generate_fast_get_char_field() {
182 return generate_fast_get_int_field0(T_CHAR);
183 }
184
185 address JNI_FastGetField::generate_fast_get_short_field() {
186 return generate_fast_get_int_field0(T_SHORT);
187 }
188
189 address JNI_FastGetField::generate_fast_get_int_field() {
190 return generate_fast_get_int_field0(T_INT);
191 }
192
193 address JNI_FastGetField::generate_fast_get_long_field() {
194 return generate_fast_get_int_field0(T_LONG);
195 }
196
197 address JNI_FastGetField::generate_fast_get_float_field() {
198 return generate_fast_get_int_field0(T_FLOAT);
199 }
200
201 address JNI_FastGetField::generate_fast_get_double_field() {
202 return generate_fast_get_int_field0(T_DOUBLE);
203 }