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