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
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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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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 "prims/jvmtiExport.hpp"
34 #include "runtime/safepoint.hpp"
35 
36 #define __ masm->
37 
38 #define BUFFER_SIZE 48*BytesPerInstWord
39 
40 
41 // Common register usage:
42 // R3/F0:      result
43 // R3_ARG1:    jni env
44 // R4_ARG2:    obj
45 // R5_ARG3:    jfield id
46 
generate_fast_get_int_field0(BasicType type)47 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
48   const char *name;
49   switch (type) {
50     case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
51     case T_BYTE:    name = "jni_fast_GetByteField";    break;
52     case T_CHAR:    name = "jni_fast_GetCharField";    break;
53     case T_SHORT:   name = "jni_fast_GetShortField";   break;
54     case T_INT:     name = "jni_fast_GetIntField";     break;
55     case T_LONG:    name = "jni_fast_GetLongField";    break;
56     case T_FLOAT:   name = "jni_fast_GetFloatField";   break;
57     case T_DOUBLE:  name = "jni_fast_GetDoubleField";  break;
58     default:        ShouldNotReachHere();
59       name = NULL;  // unreachable
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 = __ function_entry();
66 
67   Label slow;
68 
69   const Register Rcounter_addr = R6_ARG4,
70                  Rcounter      = R7_ARG5,
71                  Robj          = R8_ARG6,
72                  Rtmp          = R9_ARG7;
73   const int counter_offs = __ load_const_optimized(Rcounter_addr,
74                                                    SafepointSynchronize::safepoint_counter_addr(),
75                                                    R0, true);
76 
77   __ ld(Rcounter, counter_offs, Rcounter_addr);
78   __ andi_(R0, Rcounter, 1);
79   __ bne(CCR0, slow);
80 
81   if (support_IRIW_for_not_multiple_copy_atomic_cpu) {
82     // Field may be volatile.
83     __ fence();
84   } else {
85     // Using acquire to order wrt. JVMTI check and load of result.
86     __ isync(); // order wrt. to following load(s)
87   }
88 
89   if (JvmtiExport::can_post_field_access()) {
90     // Check to see if a field access watch has been set before we
91     // take the fast path.
92     int fac_offs = __ load_const_optimized(Rtmp, JvmtiExport::get_field_access_count_addr(),
93                                            R0, true);
94     __ lwa(Rtmp, fac_offs, Rtmp);
95     __ cmpwi(CCR0, Rtmp, 0);
96     __ bne(CCR0, slow);
97   }
98 
99   BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
100   bs->try_resolve_jobject_in_native(masm, Robj, R3_ARG1, R4_ARG2, Rtmp, slow);
101 
102   __ srwi(Rtmp, R5_ARG3, 2); // offset
103 
104   assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
105   speculative_load_pclist[count] = __ pc();   // Used by the segfault handler
106   bool is_fp = false;
107   switch (type) {
108     case T_BOOLEAN: __ lbzx(Rtmp, Rtmp, Robj); break;
109     case T_BYTE:    __ lbzx(Rtmp, Rtmp, Robj); __ extsb(Rtmp, Rtmp); break;
110     case T_CHAR:    __ lhzx(Rtmp, Rtmp, Robj); break;
111     case T_SHORT:   __ lhax(Rtmp, Rtmp, Robj); break;
112     case T_INT:     __ lwax(Rtmp, Rtmp, Robj); break;
113     case T_LONG:    __ ldx( Rtmp, Rtmp, Robj); break;
114     case T_FLOAT:   __ lfsx(F1_RET, Rtmp, Robj); is_fp = true; break;
115     case T_DOUBLE:  __ lfdx(F1_RET, Rtmp, Robj); is_fp = true; break;
116     default:        ShouldNotReachHere();
117   }
118 
119   // Order preceding load(s) wrt. succeeding check (LoadStore for volatile field).
120   if (is_fp) {
121     Label next;
122     __ fcmpu(CCR0, F1_RET, F1_RET);
123     __ bne(CCR0, next);
124     __ bind(next);
125   } else {
126     __ twi_0(Rtmp);
127   }
128   __ isync();
129 
130   __ ld(R0, counter_offs, Rcounter_addr);
131   __ cmpd(CCR0, R0, Rcounter);
132   __ bne(CCR0, slow);
133 
134   if (!is_fp) {
135     __ mr(R3_RET, Rtmp);
136   }
137   __ blr();
138 
139   slowcase_entry_pclist[count++] = __ pc();
140   __ bind(slow);
141   address slow_case_addr;
142   switch (type) {
143     case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
144     case T_BYTE:    slow_case_addr = jni_GetByteField_addr();    break;
145     case T_CHAR:    slow_case_addr = jni_GetCharField_addr();    break;
146     case T_SHORT:   slow_case_addr = jni_GetShortField_addr();   break;
147     case T_INT:     slow_case_addr = jni_GetIntField_addr();     break;
148     case T_LONG:    slow_case_addr = jni_GetLongField_addr();    break;
149     case T_FLOAT:   slow_case_addr = jni_GetFloatField_addr();   break;
150     case T_DOUBLE:  slow_case_addr = jni_GetDoubleField_addr();  break;
151     default:        ShouldNotReachHere();
152       slow_case_addr = NULL;  // unreachable
153   }
154   __ load_const_optimized(R12, slow_case_addr, R0);
155   __ call_c_and_return_to_caller(R12); // tail call
156 
157   __ flush();
158 
159   return fast_entry;
160 }
161 
generate_fast_get_boolean_field()162 address JNI_FastGetField::generate_fast_get_boolean_field() {
163   return generate_fast_get_int_field0(T_BOOLEAN);
164 }
165 
generate_fast_get_byte_field()166 address JNI_FastGetField::generate_fast_get_byte_field() {
167   return generate_fast_get_int_field0(T_BYTE);
168 }
169 
generate_fast_get_char_field()170 address JNI_FastGetField::generate_fast_get_char_field() {
171   return generate_fast_get_int_field0(T_CHAR);
172 }
173 
generate_fast_get_short_field()174 address JNI_FastGetField::generate_fast_get_short_field() {
175   return generate_fast_get_int_field0(T_SHORT);
176 }
177 
generate_fast_get_int_field()178 address JNI_FastGetField::generate_fast_get_int_field() {
179   return generate_fast_get_int_field0(T_INT);
180 }
181 
generate_fast_get_long_field()182 address JNI_FastGetField::generate_fast_get_long_field() {
183   return generate_fast_get_int_field0(T_LONG);
184 }
185 
generate_fast_get_float_field()186 address JNI_FastGetField::generate_fast_get_float_field() {
187   return generate_fast_get_int_field0(T_FLOAT);
188 }
189 
generate_fast_get_double_field()190 address JNI_FastGetField::generate_fast_get_double_field() {
191   return generate_fast_get_int_field0(T_DOUBLE);
192 }
193