1 /*
2 * Copyright (c) 2004, 2026, Oracle and/or its affiliates. All rights reserved.
3 * Copyright (c) 2014, 2020, Red Hat Inc. All rights reserved.
4 * Copyright (c) 2020, 2023, Huawei Technologies Co., Ltd. All rights reserved.
5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
6 *
7 * This code is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License version 2 only, as
9 * published by the Free Software Foundation.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 *
25 */
26
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 "prims/jvmtiExport.hpp"
34 #include "runtime/jfieldIDWorkaround.hpp"
35 #include "runtime/safepoint.hpp"
36
37 #define __ masm->
38
39 #define BUFFER_SIZE 30*wordSize
40
41 // Instead of issuing a LoadLoad barrier we create an address
42 // dependency between loads; this might be more efficient.
43
44 // Common register usage:
45 // x10/f10: result
46 // c_rarg0: jni env
47 // c_rarg1: obj
48 // c_rarg2: jfield id
49
50 static const Register robj = x13;
51 static const Register rcounter = x14;
52 static const Register roffset = x15;
53 static const Register rcounter_addr = x16;
54 static const Register result = x17;
55
56 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
57 const char *name;
58 switch (type) {
59 case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
60 case T_BYTE: name = "jni_fast_GetByteField"; break;
61 case T_CHAR: name = "jni_fast_GetCharField"; break;
62 case T_SHORT: name = "jni_fast_GetShortField"; break;
63 case T_INT: name = "jni_fast_GetIntField"; break;
64 case T_LONG: name = "jni_fast_GetLongField"; break;
65 case T_FLOAT: name = "jni_fast_GetFloatField"; break;
66 case T_DOUBLE: name = "jni_fast_GetDoubleField"; break;
67 default: ShouldNotReachHere();
68 name = nullptr; // unreachable
69 }
70 ResourceMark rm;
71 BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
72 CodeBuffer cbuf(blob);
73 MacroAssembler* masm = new MacroAssembler(&cbuf);
74 address fast_entry = __ pc();
75
76 Label slow;
77 ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
78 __ la(rcounter_addr, counter);
79 __ lwu(rcounter, Address(rcounter_addr));
80 // An even value means there are no ongoing safepoint operations
81 __ test_bit(t0, rcounter, 0);
82 __ bnez(t0, slow);
83
84 if (JvmtiExport::can_post_field_access()) {
85 // Using barrier to order wrt. JVMTI check and load of result.
86 __ membar(MacroAssembler::LoadLoad);
87
88 // Check to see if a field access watch has been set before we
89 // take the fast path.
90 __ lwu(result, ExternalAddress(JvmtiExport::get_field_access_count_addr()));
91 __ bnez(result, slow);
92
93 __ mv(robj, c_rarg1);
94 } else {
95 // Using address dependency to order wrt. load of result.
96 __ xorr(robj, c_rarg1, rcounter);
97 __ xorr(robj, robj, rcounter); // obj, since
98 // robj ^ rcounter ^ rcounter == robj
99 // robj is address dependent on rcounter.
100 }
101
102 // Both robj and t0 are clobbered by try_resolve_jobject_in_native.
103 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
104 assert_cond(bs != nullptr);
105 bs->try_resolve_jobject_in_native(masm, c_rarg0, robj, t0, slow);
106
107 __ srli(roffset, c_rarg2, jfieldIDWorkaround::offset_shift); // offset
108
109 assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
110 speculative_load_pclist[count] = __ pc(); // Used by the segfault handler
111 __ add(roffset, robj, roffset);
112
113 switch (type) {
114 case T_BOOLEAN: __ lbu(result, Address(roffset, 0)); break;
115 case T_BYTE: __ lb(result, Address(roffset, 0)); break;
116 case T_CHAR: __ lhu(result, Address(roffset, 0)); break;
117 case T_SHORT: __ lh(result, Address(roffset, 0)); break;
118 case T_INT: __ lw(result, Address(roffset, 0)); break;
119 case T_LONG: __ ld(result, Address(roffset, 0)); break;
120 case T_FLOAT: {
121 __ flw(f28, Address(roffset, 0)); // f28 as temporaries
122 __ fmv_x_w(result, f28); // f{31--0}-->x
123 break;
124 }
125 case T_DOUBLE: {
126 __ fld(f28, Address(roffset, 0)); // f28 as temporaries
127 __ fmv_x_d(result, f28); // d{63--0}-->x
128 break;
129 }
130 default: ShouldNotReachHere();
131 }
132
133 // Using acquire: Order JVMTI check and load of result wrt. succeeding check
134 // (LoadStore for volatile field).
135 __ membar(MacroAssembler::LoadLoad | MacroAssembler::LoadStore);
136
137 __ lw(t0, Address(rcounter_addr));
138 __ bne(rcounter, t0, slow);
139
140 switch (type) {
141 case T_FLOAT: __ fmv_w_x(f10, result); break;
142 case T_DOUBLE: __ fmv_d_x(f10, result); break;
143 default: __ mv(x10, result); break;
144 }
145 __ ret();
146
147 slowcase_entry_pclist[count++] = __ pc();
148 __ bind(slow);
149 address slow_case_addr;
150 switch (type) {
151 case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
152 case T_BYTE: slow_case_addr = jni_GetByteField_addr(); break;
153 case T_CHAR: slow_case_addr = jni_GetCharField_addr(); break;
154 case T_SHORT: slow_case_addr = jni_GetShortField_addr(); break;
155 case T_INT: slow_case_addr = jni_GetIntField_addr(); break;
156 case T_LONG: slow_case_addr = jni_GetLongField_addr(); break;
157 case T_FLOAT: slow_case_addr = jni_GetFloatField_addr(); break;
158 case T_DOUBLE: slow_case_addr = jni_GetDoubleField_addr(); break;
159 default: ShouldNotReachHere();
160 slow_case_addr = nullptr; // unreachable
161 }
162
163 {
164 __ enter();
165 __ rt_call(slow_case_addr);
166 __ leave();
167 __ ret();
168 }
169 __ flush();
170
171 return fast_entry;
172 }
173
174
175 address JNI_FastGetField::generate_fast_get_boolean_field() {
176 return generate_fast_get_int_field0(T_BOOLEAN);
177 }
178
179 address JNI_FastGetField::generate_fast_get_byte_field() {
180 return generate_fast_get_int_field0(T_BYTE);
181 }
182
183 address JNI_FastGetField::generate_fast_get_char_field() {
184 return generate_fast_get_int_field0(T_CHAR);
185 }
186
187 address JNI_FastGetField::generate_fast_get_short_field() {
188 return generate_fast_get_int_field0(T_SHORT);
189 }
190
191 address JNI_FastGetField::generate_fast_get_int_field() {
192 return generate_fast_get_int_field0(T_INT);
193 }
194
195 address JNI_FastGetField::generate_fast_get_long_field() {
196 return generate_fast_get_int_field0(T_LONG);
197 }
198
199 address JNI_FastGetField::generate_fast_get_float_field() {
200 return generate_fast_get_int_field0(T_FLOAT);
201 }
202
203 address JNI_FastGetField::generate_fast_get_double_field() {
204 return generate_fast_get_int_field0(T_DOUBLE);
205 }