1 /*
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3  * Copyright (c) 2012, 2019 SAP SE. All rights reserved.
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This code is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License version 2 only, as
8  * published by the Free Software Foundation.
9  *
10  * This code is distributed in the hope that it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
13  * version 2 for more details (a copy is included in the LICENSE file that
14  * accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License version
17  * 2 along with this work; if not, write to the Free Software Foundation,
18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19  *
20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24  */
25 
26 #include "precompiled.hpp"
27 #include "asm/macroAssembler.inline.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 "runtime/safepoint.hpp"
34 
35 #define __ masm->
36 
37 #define BUFFER_SIZE 48*BytesPerInstWord
38 
39 
40 // Common register usage:
41 // R3/F0:      result
42 // R3_ARG1:    jni env
43 // R4_ARG2:    obj
44 // R5_ARG3:    jfield id
45 
generate_fast_get_int_field0(BasicType type)46 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
47   const char *name;
48   switch (type) {
49     case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
50     case T_BYTE:    name = "jni_fast_GetByteField";    break;
51     case T_CHAR:    name = "jni_fast_GetCharField";    break;
52     case T_SHORT:   name = "jni_fast_GetShortField";   break;
53     case T_INT:     name = "jni_fast_GetIntField";     break;
54     case T_LONG:    name = "jni_fast_GetLongField";    break;
55     case T_FLOAT:   name = "jni_fast_GetFloatField";   break;
56     case T_DOUBLE:  name = "jni_fast_GetDoubleField";  break;
57     default:        ShouldNotReachHere();
58       name = NULL;  // unreachable
59   }
60   ResourceMark rm;
61   BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
62   CodeBuffer cbuf(blob);
63   MacroAssembler* masm = new MacroAssembler(&cbuf);
64   address fast_entry = __ function_entry();
65 
66   Label slow;
67 
68   const Register Rcounter_addr = R6_ARG4,
69                  Rcounter      = R7_ARG5,
70                  Robj          = R8_ARG6,
71                  Rtmp          = R9_ARG7;
72   const int counter_offs = __ load_const_optimized(Rcounter_addr,
73                                                    SafepointSynchronize::safepoint_counter_addr(),
74                                                    R0, true);
75 
76   __ ld(Rcounter, counter_offs, Rcounter_addr);
77   __ andi_(R0, Rcounter, 1);
78   __ bne(CCR0, slow);
79 
80   if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
81     // Field may be volatile.
82     __ fence();
83   } else {
84     // Using acquire to order wrt. JVMTI check and load of result.
85     __ isync(); // order wrt. to following load(s)
86   }
87 
88   if (JvmtiExport::can_post_field_access()) {
89     // Check to see if a field access watch has been set before we
90     // take the fast path.
91     int fac_offs = __ load_const_optimized(Rtmp, JvmtiExport::get_field_access_count_addr(),
92                                            R0, true);
93     __ lwa(Rtmp, fac_offs, Rtmp);
94     __ cmpwi(CCR0, Rtmp, 0);
95     __ bne(CCR0, slow);
96   }
97 
98   BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
99   bs->try_resolve_jobject_in_native(masm, Robj, R3_ARG1, R4_ARG2, Rtmp, slow);
100 
101   __ srwi(Rtmp, R5_ARG3, 2); // offset
102 
103   assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
104   speculative_load_pclist[count] = __ pc();   // Used by the segfault handler
105   bool is_fp = false;
106   switch (type) {
107     case T_BOOLEAN: __ lbzx(Rtmp, Rtmp, Robj); break;
108     case T_BYTE:    __ lbzx(Rtmp, Rtmp, Robj); __ extsb(Rtmp, Rtmp); break;
109     case T_CHAR:    __ lhzx(Rtmp, Rtmp, Robj); break;
110     case T_SHORT:   __ lhax(Rtmp, Rtmp, Robj); break;
111     case T_INT:     __ lwax(Rtmp, Rtmp, Robj); break;
112     case T_LONG:    __ ldx( Rtmp, Rtmp, Robj); break;
113     case T_FLOAT:   __ lfsx(F1_RET, Rtmp, Robj); is_fp = true; break;
114     case T_DOUBLE:  __ lfdx(F1_RET, Rtmp, Robj); is_fp = true; break;
115     default:        ShouldNotReachHere();
116   }
117 
118   // Order preceding load(s) wrt. succeeding check (LoadStore for volatile field).
119   if (is_fp) {
120     Label next;
121     __ fcmpu(CCR0, F1_RET, F1_RET);
122     __ bne(CCR0, next);
123     __ bind(next);
124   } else {
125     __ twi_0(Rtmp);
126   }
127   __ isync();
128 
129   __ ld(R0, counter_offs, Rcounter_addr);
130   __ cmpd(CCR0, R0, Rcounter);
131   __ bne(CCR0, slow);
132 
133   if (!is_fp) {
134     __ mr(R3_RET, Rtmp);
135   }
136   __ blr();
137 
138   slowcase_entry_pclist[count++] = __ pc();
139   __ bind(slow);
140   address slow_case_addr;
141   switch (type) {
142     case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
143     case T_BYTE:    slow_case_addr = jni_GetByteField_addr();    break;
144     case T_CHAR:    slow_case_addr = jni_GetCharField_addr();    break;
145     case T_SHORT:   slow_case_addr = jni_GetShortField_addr();   break;
146     case T_INT:     slow_case_addr = jni_GetIntField_addr();     break;
147     case T_LONG:    slow_case_addr = jni_GetLongField_addr();    break;
148     case T_FLOAT:   slow_case_addr = jni_GetFloatField_addr();   break;
149     case T_DOUBLE:  slow_case_addr = jni_GetDoubleField_addr();  break;
150     default:        ShouldNotReachHere();
151       slow_case_addr = NULL;  // unreachable
152   }
153   __ load_const_optimized(R12, slow_case_addr, R0);
154   __ call_c_and_return_to_caller(R12); // tail call
155 
156   __ flush();
157 
158   return fast_entry;
159 }
160 
generate_fast_get_boolean_field()161 address JNI_FastGetField::generate_fast_get_boolean_field() {
162   return generate_fast_get_int_field0(T_BOOLEAN);
163 }
164 
generate_fast_get_byte_field()165 address JNI_FastGetField::generate_fast_get_byte_field() {
166   return generate_fast_get_int_field0(T_BYTE);
167 }
168 
generate_fast_get_char_field()169 address JNI_FastGetField::generate_fast_get_char_field() {
170   return generate_fast_get_int_field0(T_CHAR);
171 }
172 
generate_fast_get_short_field()173 address JNI_FastGetField::generate_fast_get_short_field() {
174   return generate_fast_get_int_field0(T_SHORT);
175 }
176 
generate_fast_get_int_field()177 address JNI_FastGetField::generate_fast_get_int_field() {
178   return generate_fast_get_int_field0(T_INT);
179 }
180 
generate_fast_get_long_field()181 address JNI_FastGetField::generate_fast_get_long_field() {
182   return generate_fast_get_int_field0(T_LONG);
183 }
184 
generate_fast_get_float_field()185 address JNI_FastGetField::generate_fast_get_float_field() {
186   return generate_fast_get_int_field0(T_FLOAT);
187 }
188 
generate_fast_get_double_field()189 address JNI_FastGetField::generate_fast_get_double_field() {
190   return generate_fast_get_int_field0(T_DOUBLE);
191 }
192