1 /*
2 * Copyright (c) 2004, 2025, 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 "asm/macroAssembler.hpp"
26 #include "code/codeBlob.hpp"
27 #include "gc/shared/barrierSet.hpp"
28 #include "gc/shared/barrierSetAssembler.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "prims/jniFastGetField.hpp"
31 #include "prims/jvm_misc.hpp"
32 #include "runtime/jfieldIDWorkaround.hpp"
33 #include "prims/jvmtiExport.hpp"
34 #include "runtime/safepoint.hpp"
35
36 #define __ masm->
37
38 #define BUFFER_SIZE 40*wordSize
39
40 // Common register usage:
41 // rax/xmm0: result
42 // c_rarg0: jni env
43 // c_rarg1: obj
44 // c_rarg2: jfield id
45
46 static const Register rtmp = rax; // r8 == c_rarg2 on Windows
47 static const Register robj = r9;
48 static const Register roffset = r10;
49 static const Register rcounter = r11;
50
51 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
52 const char *name = nullptr;
53 switch (type) {
54 case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
55 case T_BYTE: name = "jni_fast_GetByteField"; break;
56 case T_CHAR: name = "jni_fast_GetCharField"; break;
57 case T_SHORT: name = "jni_fast_GetShortField"; break;
58 case T_INT: name = "jni_fast_GetIntField"; break;
59 case T_LONG: name = "jni_fast_GetLongField"; break;
60 default: ShouldNotReachHere();
61 }
62 ResourceMark rm;
63 BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
64 CodeBuffer cbuf(blob);
65 MacroAssembler* masm = new MacroAssembler(&cbuf);
66 address fast_entry = __ pc();
67
68 Label slow;
69
70 ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
71 __ mov32 (rcounter, counter);
72 __ mov (robj, c_rarg1);
73 __ testb (rcounter, 1);
74 __ jcc (Assembler::notZero, slow);
75
76 if (JvmtiExport::can_post_field_access()) {
77 // Check to see if a field access watch has been set before we take the fast path.
78 assert_different_registers(rscratch1, robj, rcounter);
79 __ cmp32(ExternalAddress(JvmtiExport::get_field_access_count_addr()), 0, rscratch1);
80 __ jcc(Assembler::notZero, slow);
81 }
82
83 __ mov (roffset, c_rarg2);
84 __ shrptr(roffset, jfieldIDWorkaround::offset_shift); // offset
85
86 // Both robj and rtmp are clobbered by try_resolve_jobject_in_native.
87 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
88 bs->try_resolve_jobject_in_native(masm, /* jni_env */ c_rarg0, robj, rtmp, slow);
89 DEBUG_ONLY(__ movl(rtmp, 0xDEADC0DE);)
90
91 assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
92 speculative_load_pclist[count] = __ pc();
93 switch (type) {
94 case T_BOOLEAN: __ movzbl (rax, Address(robj, roffset, Address::times_1)); break;
95 case T_BYTE: __ movsbl (rax, Address(robj, roffset, Address::times_1)); break;
96 case T_CHAR: __ movzwl (rax, Address(robj, roffset, Address::times_1)); break;
97 case T_SHORT: __ movswl (rax, Address(robj, roffset, Address::times_1)); break;
98 case T_INT: __ movl (rax, Address(robj, roffset, Address::times_1)); break;
99 case T_LONG: __ movq (rax, Address(robj, roffset, Address::times_1)); break;
100 default: ShouldNotReachHere();
101 }
102
103 __ cmp32 (rcounter, counter, rscratch1);
104 __ jcc (Assembler::notEqual, slow);
105
106 __ ret (0);
107
108 slowcase_entry_pclist[count++] = __ pc();
109 __ bind (slow);
110 address slow_case_addr = nullptr;
111 switch (type) {
112 case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
113 case T_BYTE: slow_case_addr = jni_GetByteField_addr(); break;
114 case T_CHAR: slow_case_addr = jni_GetCharField_addr(); break;
115 case T_SHORT: slow_case_addr = jni_GetShortField_addr(); break;
116 case T_INT: slow_case_addr = jni_GetIntField_addr(); break;
117 case T_LONG: slow_case_addr = jni_GetLongField_addr(); break;
118 default: break;
119 }
120 // tail call
121 __ jump (RuntimeAddress(slow_case_addr), rscratch1);
122
123 __ flush ();
124
125 return fast_entry;
126 }
127
128 address JNI_FastGetField::generate_fast_get_boolean_field() {
129 return generate_fast_get_int_field0(T_BOOLEAN);
130 }
131
132 address JNI_FastGetField::generate_fast_get_byte_field() {
133 return generate_fast_get_int_field0(T_BYTE);
134 }
135
136 address JNI_FastGetField::generate_fast_get_char_field() {
137 return generate_fast_get_int_field0(T_CHAR);
138 }
139
140 address JNI_FastGetField::generate_fast_get_short_field() {
141 return generate_fast_get_int_field0(T_SHORT);
142 }
143
144 address JNI_FastGetField::generate_fast_get_int_field() {
145 return generate_fast_get_int_field0(T_INT);
146 }
147
148 address JNI_FastGetField::generate_fast_get_long_field() {
149 return generate_fast_get_int_field0(T_LONG);
150 }
151
152 address JNI_FastGetField::generate_fast_get_float_field0(BasicType type) {
153 const char *name = nullptr;
154 switch (type) {
155 case T_FLOAT: name = "jni_fast_GetFloatField"; break;
156 case T_DOUBLE: name = "jni_fast_GetDoubleField"; break;
157 default: ShouldNotReachHere();
158 }
159 ResourceMark rm;
160 BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
161 CodeBuffer cbuf(blob);
162 MacroAssembler* masm = new MacroAssembler(&cbuf);
163 address fast_entry = __ pc();
164
165 Label slow;
166
167 ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
168 __ mov32 (rcounter, counter);
169 __ mov (robj, c_rarg1);
170 __ testb (rcounter, 1);
171 __ jcc (Assembler::notZero, slow);
172
173 if (JvmtiExport::can_post_field_access()) {
174 // Check to see if a field access watch has been set before we
175 // take the fast path.
176 __ cmp32(ExternalAddress(JvmtiExport::get_field_access_count_addr()), 0, rscratch1);
177 __ jcc(Assembler::notZero, slow);
178 }
179
180 // Both robj and rtmp are clobbered by try_resolve_jobject_in_native.
181 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
182 bs->try_resolve_jobject_in_native(masm, /* jni_env */ c_rarg0, robj, rtmp, slow);
183 DEBUG_ONLY(__ movl(rtmp, 0xDEADC0DE);)
184
185 __ mov (roffset, c_rarg2);
186 __ shrptr(roffset, jfieldIDWorkaround::offset_shift); // offset
187
188 assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
189 speculative_load_pclist[count] = __ pc();
190 switch (type) {
191 case T_FLOAT: __ movflt (xmm0, Address(robj, roffset, Address::times_1)); break;
192 case T_DOUBLE: __ movdbl (xmm0, Address(robj, roffset, Address::times_1)); break;
193 default: ShouldNotReachHere();
194 }
195 __ cmp32 (rcounter, counter, rscratch1);
196 __ jcc (Assembler::notEqual, slow);
197
198 __ ret (0);
199
200 slowcase_entry_pclist[count++] = __ pc();
201 __ bind (slow);
202 address slow_case_addr = nullptr;
203 switch (type) {
204 case T_FLOAT: slow_case_addr = jni_GetFloatField_addr(); break;
205 case T_DOUBLE: slow_case_addr = jni_GetDoubleField_addr(); break;
206 default: break;
207 }
208 // tail call
209 __ jump (RuntimeAddress(slow_case_addr), rscratch1);
210
211 __ flush ();
212
213 return fast_entry;
214 }
215
216 address JNI_FastGetField::generate_fast_get_float_field() {
217 return generate_fast_get_float_field0(T_FLOAT);
218 }
219
220 address JNI_FastGetField::generate_fast_get_double_field() {
221 return generate_fast_get_float_field0(T_DOUBLE);
222 }