1 /*
2  * Copyright (c) 2004, 2020, 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 "gc/shared/barrierSet.hpp"
28 #include "gc/shared/barrierSetAssembler.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "prims/jniFastGetField.hpp"
31 #include "prims/jvm_misc.hpp"
32 #include "prims/jvmtiExport.hpp"
33 #include "runtime/safepoint.hpp"
34 
35 #define __ masm->
36 
37 #define BUFFER_SIZE 30*wordSize
38 
39 // Common register usage:
40 // rax/xmm0: result
41 // c_rarg0:    jni env
42 // c_rarg1:    obj
43 // c_rarg2:    jfield id
44 
45 static const Register rtmp     = rax; // r8 == c_rarg2 on Windows
46 static const Register robj     = r9;
47 static const Register roffset  = r10;
48 static const Register rcounter = r11;
49 
50 // Warning: do not use rip relative addressing after the first counter load
51 // since that may scratch r10!
52 
generate_fast_get_int_field0(BasicType type)53 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
54   const char *name = NULL;
55   switch (type) {
56     case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
57     case T_BYTE:    name = "jni_fast_GetByteField";    break;
58     case T_CHAR:    name = "jni_fast_GetCharField";    break;
59     case T_SHORT:   name = "jni_fast_GetShortField";   break;
60     case T_INT:     name = "jni_fast_GetIntField";     break;
61     case T_LONG:    name = "jni_fast_GetLongField";    break;
62     default:        ShouldNotReachHere();
63   }
64   ResourceMark rm;
65   BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
66   CodeBuffer cbuf(blob);
67   MacroAssembler* masm = new MacroAssembler(&cbuf);
68   address fast_entry = __ pc();
69 
70   Label slow;
71 
72   ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
73   __ mov32 (rcounter, counter);
74   __ mov   (robj, c_rarg1);
75   __ testb (rcounter, 1);
76   __ jcc (Assembler::notZero, slow);
77 
78   if (JvmtiExport::can_post_field_access()) {
79     // Check to see if a field access watch has been set before we
80     // take the fast path.
81     assert_different_registers(rscratch1, robj, rcounter); // cmp32 clobbers rscratch1!
82     __ cmp32(ExternalAddress((address) JvmtiExport::get_field_access_count_addr()), 0);
83     __ jcc(Assembler::notZero, slow);
84   }
85 
86   __ mov   (roffset, c_rarg2);
87   __ shrptr(roffset, 2);                         // offset
88 
89   // Both robj and rtmp are clobbered by try_resolve_jobject_in_native.
90   BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
91   bs->try_resolve_jobject_in_native(masm, /* jni_env */ c_rarg0, robj, rtmp, slow);
92   DEBUG_ONLY(__ movl(rtmp, 0xDEADC0DE);)
93 
94   assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
95   speculative_load_pclist[count] = __ pc();
96   switch (type) {
97     case T_BOOLEAN: __ movzbl (rax, Address(robj, roffset, Address::times_1)); break;
98     case T_BYTE:    __ movsbl (rax, Address(robj, roffset, Address::times_1)); break;
99     case T_CHAR:    __ movzwl (rax, Address(robj, roffset, Address::times_1)); break;
100     case T_SHORT:   __ movswl (rax, Address(robj, roffset, Address::times_1)); break;
101     case T_INT:     __ movl   (rax, Address(robj, roffset, Address::times_1)); break;
102     case T_LONG:    __ movq   (rax, Address(robj, roffset, Address::times_1)); break;
103     default:        ShouldNotReachHere();
104   }
105 
106   __ cmp32 (rcounter, counter);
107   __ jcc (Assembler::notEqual, slow);
108 
109   __ ret (0);
110 
111   slowcase_entry_pclist[count++] = __ pc();
112   __ bind (slow);
113   address slow_case_addr = NULL;
114   switch (type) {
115     case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
116     case T_BYTE:    slow_case_addr = jni_GetByteField_addr();    break;
117     case T_CHAR:    slow_case_addr = jni_GetCharField_addr();    break;
118     case T_SHORT:   slow_case_addr = jni_GetShortField_addr();   break;
119     case T_INT:     slow_case_addr = jni_GetIntField_addr();     break;
120     case T_LONG:    slow_case_addr = jni_GetLongField_addr();    break;
121     default:                                                     break;
122   }
123   // tail call
124   __ jump (ExternalAddress(slow_case_addr));
125 
126   __ flush ();
127 
128   return fast_entry;
129 }
130 
generate_fast_get_boolean_field()131 address JNI_FastGetField::generate_fast_get_boolean_field() {
132   return generate_fast_get_int_field0(T_BOOLEAN);
133 }
134 
generate_fast_get_byte_field()135 address JNI_FastGetField::generate_fast_get_byte_field() {
136   return generate_fast_get_int_field0(T_BYTE);
137 }
138 
generate_fast_get_char_field()139 address JNI_FastGetField::generate_fast_get_char_field() {
140   return generate_fast_get_int_field0(T_CHAR);
141 }
142 
generate_fast_get_short_field()143 address JNI_FastGetField::generate_fast_get_short_field() {
144   return generate_fast_get_int_field0(T_SHORT);
145 }
146 
generate_fast_get_int_field()147 address JNI_FastGetField::generate_fast_get_int_field() {
148   return generate_fast_get_int_field0(T_INT);
149 }
150 
generate_fast_get_long_field()151 address JNI_FastGetField::generate_fast_get_long_field() {
152   return generate_fast_get_int_field0(T_LONG);
153 }
154 
generate_fast_get_float_field0(BasicType type)155 address JNI_FastGetField::generate_fast_get_float_field0(BasicType type) {
156   const char *name = NULL;
157   switch (type) {
158     case T_FLOAT:     name = "jni_fast_GetFloatField";     break;
159     case T_DOUBLE:    name = "jni_fast_GetDoubleField";    break;
160     default:          ShouldNotReachHere();
161   }
162   ResourceMark rm;
163   BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
164   CodeBuffer cbuf(blob);
165   MacroAssembler* masm = new MacroAssembler(&cbuf);
166   address fast_entry = __ pc();
167 
168   Label slow;
169 
170   ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
171   __ mov32 (rcounter, counter);
172   __ mov   (robj, c_rarg1);
173   __ testb (rcounter, 1);
174   __ jcc (Assembler::notZero, slow);
175 
176   if (JvmtiExport::can_post_field_access()) {
177     // Check to see if a field access watch has been set before we
178     // take the fast path.
179     __ cmp32(ExternalAddress((address) JvmtiExport::get_field_access_count_addr()), 0);
180     __ jcc(Assembler::notZero, slow);
181   }
182 
183   // Both robj and rtmp are clobbered by try_resolve_jobject_in_native.
184   BarrierSetAssembler* bs = BarrierSet::barrier_set()->barrier_set_assembler();
185   bs->try_resolve_jobject_in_native(masm, /* jni_env */ c_rarg0, robj, rtmp, slow);
186   DEBUG_ONLY(__ movl(rtmp, 0xDEADC0DE);)
187 
188   __ mov   (roffset, c_rarg2);
189   __ shrptr(roffset, 2);                         // offset
190 
191   assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
192   speculative_load_pclist[count] = __ pc();
193   switch (type) {
194     case T_FLOAT:  __ movflt (xmm0, Address(robj, roffset, Address::times_1)); break;
195     case T_DOUBLE: __ movdbl (xmm0, Address(robj, roffset, Address::times_1)); break;
196     default:        ShouldNotReachHere();
197   }
198   __ cmp32 (rcounter, counter);
199   __ jcc (Assembler::notEqual, slow);
200 
201   __ ret (0);
202 
203   slowcase_entry_pclist[count++] = __ pc();
204   __ bind (slow);
205   address slow_case_addr = NULL;
206   switch (type) {
207     case T_FLOAT:     slow_case_addr = jni_GetFloatField_addr();  break;
208     case T_DOUBLE:    slow_case_addr = jni_GetDoubleField_addr(); break;
209     default:                                                      break;
210   }
211   // tail call
212   __ jump (ExternalAddress(slow_case_addr));
213 
214   __ flush ();
215 
216   return fast_entry;
217 }
218 
generate_fast_get_float_field()219 address JNI_FastGetField::generate_fast_get_float_field() {
220   return generate_fast_get_float_field0(T_FLOAT);
221 }
222 
generate_fast_get_double_field()223 address JNI_FastGetField::generate_fast_get_double_field() {
224   return generate_fast_get_float_field0(T_DOUBLE);
225 }
226