1 /*
   2  * Copyright (c) 2004, 2017, 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 "memory/resourceArea.hpp"
  28 #include "prims/jniFastGetField.hpp"
  29 #include "prims/jvm_misc.hpp"
  30 #include "runtime/safepoint.hpp"
  31 
  32 #define __ masm->
  33 
  34 #define BUFFER_SIZE 30*wordSize
  35 
  36 // Instead of issuing lfence for LoadLoad barrier, we create data dependency
  37 // between loads, which is more efficient than lfence.
  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 robj          = r9;
  46 static const Register rcounter      = r10;
  47 static const Register roffset       = r11;
  48 static const Register rcounter_addr = r11;
  49 
  50 // Warning: do not use rip relative addressing after the first counter load
  51 // since that may scratch r10!
  52 
  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   if (os::is_MP()) {
  78     __ xorptr(robj, rcounter);
  79     __ xorptr(robj, rcounter);                   // obj, since
  80                                                 // robj ^ rcounter ^ rcounter == robj
  81                                                 // robj is data dependent on rcounter.
  82   }
  83 
  84   __ clear_jweak_tag(robj);
  85 
  86   __ movptr(robj, Address(robj, 0));             // *obj
  87   __ mov   (roffset, c_rarg2);
  88   __ shrptr(roffset, 2);                         // offset
  89 
  90   assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
  91   speculative_load_pclist[count] = __ pc();
  92   switch (type) {
  93     case T_BOOLEAN: __ movzbl (rax, Address(robj, roffset, Address::times_1)); break;
  94     case T_BYTE:    __ movsbl (rax, Address(robj, roffset, Address::times_1)); break;
  95     case T_CHAR:    __ movzwl (rax, Address(robj, roffset, Address::times_1)); break;
  96     case T_SHORT:   __ movswl (rax, Address(robj, roffset, Address::times_1)); break;
  97     case T_INT:     __ movl   (rax, Address(robj, roffset, Address::times_1)); break;
  98     case T_LONG:    __ movq   (rax, Address(robj, roffset, Address::times_1)); break;
  99     default:        ShouldNotReachHere();
 100   }
 101 
 102   if (os::is_MP()) {
 103     __ lea(rcounter_addr, counter);
 104     // ca is data dependent on rax.
 105     __ xorptr(rcounter_addr, rax);
 106     __ xorptr(rcounter_addr, rax);
 107     __ cmpl (rcounter, Address(rcounter_addr, 0));
 108   } else {
 109     __ cmp32 (rcounter, counter);
 110   }
 111   __ jcc (Assembler::notEqual, slow);
 112 
 113   __ ret (0);
 114 
 115   slowcase_entry_pclist[count++] = __ pc();
 116   __ bind (slow);
 117   address slow_case_addr = NULL;
 118   switch (type) {
 119     case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
 120     case T_BYTE:    slow_case_addr = jni_GetByteField_addr();    break;
 121     case T_CHAR:    slow_case_addr = jni_GetCharField_addr();    break;
 122     case T_SHORT:   slow_case_addr = jni_GetShortField_addr();   break;
 123     case T_INT:     slow_case_addr = jni_GetIntField_addr();     break;
 124     case T_LONG:    slow_case_addr = jni_GetLongField_addr();
 125   }
 126   // tail call
 127   __ jump (ExternalAddress(slow_case_addr));
 128 
 129   __ flush ();
 130 
 131   return fast_entry;
 132 }
 133 
 134 address JNI_FastGetField::generate_fast_get_boolean_field() {
 135   return generate_fast_get_int_field0(T_BOOLEAN);
 136 }
 137 
 138 address JNI_FastGetField::generate_fast_get_byte_field() {
 139   return generate_fast_get_int_field0(T_BYTE);
 140 }
 141 
 142 address JNI_FastGetField::generate_fast_get_char_field() {
 143   return generate_fast_get_int_field0(T_CHAR);
 144 }
 145 
 146 address JNI_FastGetField::generate_fast_get_short_field() {
 147   return generate_fast_get_int_field0(T_SHORT);
 148 }
 149 
 150 address JNI_FastGetField::generate_fast_get_int_field() {
 151   return generate_fast_get_int_field0(T_INT);
 152 }
 153 
 154 address JNI_FastGetField::generate_fast_get_long_field() {
 155   return generate_fast_get_int_field0(T_LONG);
 156 }
 157 
 158 address JNI_FastGetField::generate_fast_get_float_field0(BasicType type) {
 159   const char *name = NULL;
 160   switch (type) {
 161     case T_FLOAT:     name = "jni_fast_GetFloatField";     break;
 162     case T_DOUBLE:    name = "jni_fast_GetDoubleField";    break;
 163     default:          ShouldNotReachHere();
 164   }
 165   ResourceMark rm;
 166   BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE);
 167   CodeBuffer cbuf(blob);
 168   MacroAssembler* masm = new MacroAssembler(&cbuf);
 169   address fast_entry = __ pc();
 170 
 171   Label slow;
 172 
 173   ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
 174   __ mov32 (rcounter, counter);
 175   __ mov   (robj, c_rarg1);
 176   __ testb (rcounter, 1);
 177   __ jcc (Assembler::notZero, slow);
 178   if (os::is_MP()) {
 179     __ xorptr(robj, rcounter);
 180     __ xorptr(robj, rcounter);                   // obj, since
 181                                                 // robj ^ rcounter ^ rcounter == robj
 182                                                 // robj is data dependent on rcounter.
 183   }
 184 
 185   __ clear_jweak_tag(robj);
 186 
 187   __ movptr(robj, Address(robj, 0));             // *obj
 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 
 199   if (os::is_MP()) {
 200     __ lea(rcounter_addr, counter);
 201     __ movdq (rax, xmm0);
 202     // counter address is data dependent on xmm0.
 203     __ xorptr(rcounter_addr, rax);
 204     __ xorptr(rcounter_addr, rax);
 205     __ cmpl (rcounter, Address(rcounter_addr, 0));
 206   } else {
 207     __ cmp32 (rcounter, counter);
 208   }
 209   __ jcc (Assembler::notEqual, slow);
 210 
 211   __ ret (0);
 212 
 213   slowcase_entry_pclist[count++] = __ pc();
 214   __ bind (slow);
 215   address slow_case_addr = NULL;
 216   switch (type) {
 217     case T_FLOAT:     slow_case_addr = jni_GetFloatField_addr();  break;
 218     case T_DOUBLE:    slow_case_addr = jni_GetDoubleField_addr();
 219   }
 220   // tail call
 221   __ jump (ExternalAddress(slow_case_addr));
 222 
 223   __ flush ();
 224 
 225   return fast_entry;
 226 }
 227 
 228 address JNI_FastGetField::generate_fast_get_float_field() {
 229   return generate_fast_get_float_field0(T_FLOAT);
 230 }
 231 
 232 address JNI_FastGetField::generate_fast_get_double_field() {
 233   return generate_fast_get_float_field0(T_DOUBLE);
 234 }