1 /*
2  * Copyright (c) 2008, 2019, 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 "precompiled.hpp"
26 #include "asm/macroAssembler.hpp"
27 #include "assembler_arm.inline.hpp"
28 #include "memory/resourceArea.hpp"
29 #include "prims/jniFastGetField.hpp"
30 #include "prims/jvm_misc.hpp"
31 #include "runtime/safepoint.hpp"
32 
33 #define __ masm->
34 
35 #define BUFFER_SIZE 120
36 
generate_fast_get_int_field0(BasicType type)37 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
38   const char* name = NULL;
39   address slow_case_addr = NULL;
40   switch (type) {
41     case T_BOOLEAN:
42       name = "jni_fast_GetBooleanField";
43       slow_case_addr = jni_GetBooleanField_addr();
44       break;
45     case T_BYTE:
46       name = "jni_fast_GetByteField";
47       slow_case_addr = jni_GetByteField_addr();
48       break;
49     case T_CHAR:
50       name = "jni_fast_GetCharField";
51       slow_case_addr = jni_GetCharField_addr();
52       break;
53     case T_SHORT:
54       name = "jni_fast_GetShortField";
55       slow_case_addr = jni_GetShortField_addr();
56       break;
57     case T_INT:
58       name = "jni_fast_GetIntField";
59       slow_case_addr = jni_GetIntField_addr();
60       break;
61     case T_LONG:
62       name = "jni_fast_GetLongField";
63       slow_case_addr = jni_GetLongField_addr();
64       break;
65     case T_FLOAT:
66       name = "jni_fast_GetFloatField";
67       slow_case_addr = jni_GetFloatField_addr();
68       break;
69     case T_DOUBLE:
70       name = "jni_fast_GetDoubleField";
71       slow_case_addr = jni_GetDoubleField_addr();
72       break;
73     default:
74       ShouldNotReachHere();
75   }
76 
77   // R0 - jni env
78   // R1 - object handle
79   // R2 - jfieldID
80 
81   const Register Rsafepoint_counter_addr = R3;
82   const Register Robj = R1;
83   const Register Rres = R0;
84   const Register Rres_hi = R1;
85   const Register Rsafept_cnt = Rtemp;
86   const Register Rsafept_cnt2 = Rsafepoint_counter_addr;
87   const Register Rtmp1 = R3; // same as Rsafepoint_counter_addr
88   const Register Rtmp2 = R2; // same as jfieldID
89 
90   assert_different_registers(Rsafepoint_counter_addr, Rsafept_cnt, Robj, Rres, LR);
91   assert_different_registers(Rsafept_cnt, R1, R2, Rtmp1, LR);
92   assert_different_registers(Rsafepoint_counter_addr, Rsafept_cnt, Rres, Rres_hi, Rtmp2, LR);
93   assert_different_registers(Rsafept_cnt2, Rsafept_cnt, Rres, Rres_hi, LR);
94 
95   address fast_entry;
96 
97   ResourceMark rm;
98   BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
99   CodeBuffer cbuf(blob);
100   MacroAssembler* masm = new MacroAssembler(&cbuf);
101   fast_entry = __ pc();
102   Label slow_case;
103 
104   // Safepoint check
105   InlinedAddress safepoint_counter_addr(SafepointSynchronize::safepoint_counter_addr());
106   __ ldr_literal(Rsafepoint_counter_addr, safepoint_counter_addr);
107 
108   __ push(RegisterSet(R0, R3));  // save incoming arguments for slow case
109 
110   __ ldr_s32(Rsafept_cnt, Address(Rsafepoint_counter_addr));
111   __ tbnz(Rsafept_cnt, 0, slow_case);
112 
113   __ bic(R1, R1, JNIHandles::weak_tag_mask);
114 
115   if (JvmtiExport::can_post_field_access()) {
116     // Using barrier to order wrt. JVMTI check and load of result.
117     __ membar(MacroAssembler::Membar_mask_bits(MacroAssembler::LoadLoad), Rtmp1);
118 
119     // Check to see if a field access watch has been set before we
120     // take the fast path.
121     __ ldr_global_s32(Rtmp1, (address)JvmtiExport::get_field_access_count_addr());
122     __ cbnz(Rtmp1, slow_case);
123 
124     __ ldr(Robj, Address(R1));
125   } else {
126     // Address dependency restricts memory access ordering. It's cheaper than explicit LoadLoad barrier
127     __ andr(Rtmp1, Rsafept_cnt, (unsigned)1);
128     __ ldr(Robj, Address(R1, Rtmp1));
129   }
130 
131   Address field_addr;
132   if (type != T_BOOLEAN
133       && type != T_INT
134 #ifndef __ABI_HARD__
135       && type != T_FLOAT
136 #endif // !__ABI_HARD__
137       ) {
138     // Only ldr and ldrb support embedded shift, other loads do not
139     __ add(Robj, Robj, AsmOperand(R2, lsr, 2));
140     field_addr = Address(Robj);
141   } else {
142     field_addr = Address(Robj, R2, lsr, 2);
143   }
144   assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
145   speculative_load_pclist[count] = __ pc();
146 
147   switch (type) {
148     case T_BOOLEAN:
149       __ ldrb(Rres, field_addr);
150       break;
151     case T_BYTE:
152       __ ldrsb(Rres, field_addr);
153       break;
154     case T_CHAR:
155       __ ldrh(Rres, field_addr);
156       break;
157     case T_SHORT:
158       __ ldrsh(Rres, field_addr);
159       break;
160     case T_INT:
161 #ifndef __ABI_HARD__
162     case T_FLOAT:
163 #endif
164       __ ldr_s32(Rres, field_addr);
165       break;
166     case T_LONG:
167 #ifndef __ABI_HARD__
168     case T_DOUBLE:
169 #endif
170       // Safe to use ldrd since long and double fields are 8-byte aligned
171       __ ldrd(Rres, field_addr);
172       break;
173 #ifdef __ABI_HARD__
174     case T_FLOAT:
175       __ ldr_float(S0, field_addr);
176       break;
177     case T_DOUBLE:
178       __ ldr_double(D0, field_addr);
179       break;
180 #endif // __ABI_HARD__
181     default:
182       ShouldNotReachHere();
183   }
184 
185   __ ldr_literal(Rsafepoint_counter_addr, safepoint_counter_addr);
186 #ifdef __ABI_HARD__
187   if (type == T_FLOAT || type == T_DOUBLE) {
188     __ fmrrd(Rres, Rres_hi, D0);
189   }
190 #endif // __ABI_HARD__
191 
192   // Order JVMTI check and load of result wrt. succeeding check
193   // (LoadStore for volatile field).
194   __ membar(MacroAssembler::Membar_mask_bits(MacroAssembler::LoadLoad | MacroAssembler::LoadStore), Rtmp2);
195 
196   __ ldr_s32(Rsafept_cnt2, Address(Rsafepoint_counter_addr));
197   __ cmp(Rsafept_cnt2, Rsafept_cnt);
198   // discards saved R0 R1 R2 R3
199   __ add(SP, SP, 4 * wordSize, eq);
200   __ bx(LR, eq);
201 
202   slowcase_entry_pclist[count++] = __ pc();
203 
204   __ bind(slow_case);
205   __ pop(RegisterSet(R0, R3));
206   // thumb mode switch handled by MacroAssembler::jump if needed
207   __ jump(slow_case_addr, relocInfo::none, Rtemp);
208 
209   __ bind_literal(safepoint_counter_addr);
210 
211   __ flush();
212 
213   guarantee((__ pc() - fast_entry) <= BUFFER_SIZE, "BUFFER_SIZE too small");
214 
215   return fast_entry;
216 }
217 
generate_fast_get_float_field0(BasicType type)218 address JNI_FastGetField::generate_fast_get_float_field0(BasicType type) {
219   ShouldNotReachHere();
220   return NULL;
221 }
222 
generate_fast_get_boolean_field()223 address JNI_FastGetField::generate_fast_get_boolean_field() {
224   return generate_fast_get_int_field0(T_BOOLEAN);
225 }
226 
generate_fast_get_byte_field()227 address JNI_FastGetField::generate_fast_get_byte_field() {
228   return generate_fast_get_int_field0(T_BYTE);
229 }
230 
generate_fast_get_char_field()231 address JNI_FastGetField::generate_fast_get_char_field() {
232   return generate_fast_get_int_field0(T_CHAR);
233 }
234 
generate_fast_get_short_field()235 address JNI_FastGetField::generate_fast_get_short_field() {
236   return generate_fast_get_int_field0(T_SHORT);
237 }
238 
generate_fast_get_int_field()239 address JNI_FastGetField::generate_fast_get_int_field() {
240   return generate_fast_get_int_field0(T_INT);
241 }
242 
generate_fast_get_long_field()243 address JNI_FastGetField::generate_fast_get_long_field() {
244   return generate_fast_get_int_field0(T_LONG);
245 }
246 
generate_fast_get_float_field()247 address JNI_FastGetField::generate_fast_get_float_field() {
248   return generate_fast_get_int_field0(T_FLOAT);
249 }
250 
generate_fast_get_double_field()251 address JNI_FastGetField::generate_fast_get_double_field() {
252   return generate_fast_get_int_field0(T_DOUBLE);
253 }
254