1 /*
2 * Copyright (c) 2004, 2025, 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/safepoint.hpp"
35
36 #define __ masm->
37
38 #define BUFFER_SIZE 30*wordSize
39
40 // Instead of issuing a LoadLoad barrier we create an address
41 // dependency between loads; this might be more efficient.
42
43 // Common register usage:
44 // x10/f10: result
45 // c_rarg0: jni env
46 // c_rarg1: obj
47 // c_rarg2: jfield id
48
49 static const Register robj = x13;
50 static const Register rcounter = x14;
51 static const Register roffset = x15;
52 static const Register rcounter_addr = x16;
53 static const Register result = x17;
54
55 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
56 const char *name;
57 switch (type) {
58 case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
59 case T_BYTE: name = "jni_fast_GetByteField"; break;
60 case T_CHAR: name = "jni_fast_GetCharField"; break;
61 case T_SHORT: name = "jni_fast_GetShortField"; break;
62 case T_INT: name = "jni_fast_GetIntField"; break;
63 case T_LONG: name = "jni_fast_GetLongField"; break;
64 case T_FLOAT: name = "jni_fast_GetFloatField"; break;
65 case T_DOUBLE: name = "jni_fast_GetDoubleField"; break;
66 default: ShouldNotReachHere();
67 name = nullptr; // unreachable
68 }
69 ResourceMark rm;
70 BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
71 CodeBuffer cbuf(blob);
72 MacroAssembler* masm = new MacroAssembler(&cbuf);
73 address fast_entry = __ pc();
74
75 Label slow;
76 ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
77 __ la(rcounter_addr, counter);
78 __ lwu(rcounter, Address(rcounter_addr));
79 // An even value means there are no ongoing safepoint operations
80 __ test_bit(t0, rcounter, 0);
81 __ bnez(t0, slow);
82
83 if (JvmtiExport::can_post_field_access()) {
84 // Using barrier to order wrt. JVMTI check and load of result.
85 __ membar(MacroAssembler::LoadLoad);
86
87 // Check to see if a field access watch has been set before we
88 // take the fast path.
89 __ lwu(result, ExternalAddress(JvmtiExport::get_field_access_count_addr()));
90 __ bnez(result, slow);
91
92 __ mv(robj, c_rarg1);
93 } else {
94 // Using address dependency to order wrt. load of result.
95 __ xorr(robj, c_rarg1, rcounter);
96 __ xorr(robj, robj, rcounter); // obj, since
97 // robj ^ rcounter ^ rcounter == robj
98 // robj is address dependent on rcounter.
99 }
100
101 // Both robj and t0 are clobbered by try_resolve_jobject_in_native.
102 BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
103 assert_cond(bs != nullptr);
104 bs->try_resolve_jobject_in_native(masm, c_rarg0, robj, t0, slow);
105
106 __ srli(roffset, c_rarg2, 2); // offset
107
108 assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
109 speculative_load_pclist[count] = __ pc(); // Used by the segfault handler
110 __ add(roffset, robj, roffset);
111
112 switch (type) {
113 case T_BOOLEAN: __ lbu(result, Address(roffset, 0)); break;
114 case T_BYTE: __ lb(result, Address(roffset, 0)); break;
115 case T_CHAR: __ lhu(result, Address(roffset, 0)); break;
116 case T_SHORT: __ lh(result, Address(roffset, 0)); break;
117 case T_INT: __ lw(result, Address(roffset, 0)); break;
118 case T_LONG: __ ld(result, Address(roffset, 0)); break;
119 case T_FLOAT: {
120 __ flw(f28, Address(roffset, 0)); // f28 as temporaries
121 __ fmv_x_w(result, f28); // f{31--0}-->x
122 break;
123 }
124 case T_DOUBLE: {
125 __ fld(f28, Address(roffset, 0)); // f28 as temporaries
126 __ fmv_x_d(result, f28); // d{63--0}-->x
127 break;
128 }
129 default: ShouldNotReachHere();
130 }
131
132 // Using acquire: Order JVMTI check and load of result wrt. succeeding check
133 // (LoadStore for volatile field).
134 __ membar(MacroAssembler::LoadLoad | MacroAssembler::LoadStore);
135
136 __ lw(t0, Address(rcounter_addr));
137 __ bne(rcounter, t0, slow);
138
139 switch (type) {
140 case T_FLOAT: __ fmv_w_x(f10, result); break;
141 case T_DOUBLE: __ fmv_d_x(f10, result); break;
142 default: __ mv(x10, result); break;
143 }
144 __ ret();
145
146 slowcase_entry_pclist[count++] = __ pc();
147 __ bind(slow);
148 address slow_case_addr;
149 switch (type) {
150 case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
151 case T_BYTE: slow_case_addr = jni_GetByteField_addr(); break;
152 case T_CHAR: slow_case_addr = jni_GetCharField_addr(); break;
153 case T_SHORT: slow_case_addr = jni_GetShortField_addr(); break;
154 case T_INT: slow_case_addr = jni_GetIntField_addr(); break;
155 case T_LONG: slow_case_addr = jni_GetLongField_addr(); break;
156 case T_FLOAT: slow_case_addr = jni_GetFloatField_addr(); break;
157 case T_DOUBLE: slow_case_addr = jni_GetDoubleField_addr(); break;
158 default: ShouldNotReachHere();
159 slow_case_addr = nullptr; // unreachable
160 }
161
162 {
163 __ enter();
164 __ rt_call(slow_case_addr);
165 __ leave();
166 __ ret();
167 }
168 __ flush();
169
170 return fast_entry;
171 }
172
173
174 address JNI_FastGetField::generate_fast_get_boolean_field() {
175 return generate_fast_get_int_field0(T_BOOLEAN);
176 }
177
178 address JNI_FastGetField::generate_fast_get_byte_field() {
179 return generate_fast_get_int_field0(T_BYTE);
180 }
181
182 address JNI_FastGetField::generate_fast_get_char_field() {
183 return generate_fast_get_int_field0(T_CHAR);
184 }
185
186 address JNI_FastGetField::generate_fast_get_short_field() {
187 return generate_fast_get_int_field0(T_SHORT);
188 }
189
190 address JNI_FastGetField::generate_fast_get_int_field() {
191 return generate_fast_get_int_field0(T_INT);
192 }
193
194 address JNI_FastGetField::generate_fast_get_long_field() {
195 return generate_fast_get_int_field0(T_LONG);
196 }
197
198 address JNI_FastGetField::generate_fast_get_float_field() {
199 return generate_fast_get_int_field0(T_FLOAT);
200 }
201
202 address JNI_FastGetField::generate_fast_get_double_field() {
203 return generate_fast_get_int_field0(T_DOUBLE);
204 }