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