1 /*
   2  * Copyright (c) 2004, 2019, 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
  35 
  36 #ifdef _WINDOWS
  37 GetBooleanField_t JNI_FastGetField::jni_fast_GetBooleanField_fp;
  38 GetByteField_t    JNI_FastGetField::jni_fast_GetByteField_fp;
  39 GetCharField_t    JNI_FastGetField::jni_fast_GetCharField_fp;
  40 GetShortField_t   JNI_FastGetField::jni_fast_GetShortField_fp;
  41 GetIntField_t     JNI_FastGetField::jni_fast_GetIntField_fp;
  42 GetLongField_t    JNI_FastGetField::jni_fast_GetLongField_fp;
  43 GetFloatField_t   JNI_FastGetField::jni_fast_GetFloatField_fp;
  44 GetDoubleField_t  JNI_FastGetField::jni_fast_GetDoubleField_fp;
  45 #endif
  46 
  47 // Instead of issuing lfence for LoadLoad barrier, we create data dependency
  48 // between loads, which is much more efficient than lfence.
  49 
  50 address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
  51   const char *name = NULL;
  52   switch (type) {
  53     case T_BOOLEAN: name = "jni_fast_GetBooleanField"; break;
  54     case T_BYTE:    name = "jni_fast_GetByteField";    break;
  55     case T_CHAR:    name = "jni_fast_GetCharField";    break;
  56     case T_SHORT:   name = "jni_fast_GetShortField";   break;
  57     case T_INT:     name = "jni_fast_GetIntField";     break;
  58     default:        ShouldNotReachHere();
  59   }
  60   ResourceMark rm;
  61   BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE*wordSize);
  62   CodeBuffer cbuf(blob);
  63   MacroAssembler* masm = new MacroAssembler(&cbuf);
  64   address fast_entry = __ pc();
  65 
  66   Label slow;
  67 
  68   // stack layout:    offset from rsp (in words):
  69   //  return pc        0
  70   //  jni env          1
  71   //  obj              2
  72   //  jfieldID         3
  73 
  74   ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
  75   __ mov32 (rcx, counter);
  76   __ testb (rcx, 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     __ cmp32(ExternalAddress((address) JvmtiExport::get_field_access_count_addr()), 0);
  83     __ jcc(Assembler::notZero, slow);
  84   }
  85 
  86   __ mov(rax, rcx);
  87   __ andptr(rax, 1);                         // rax, must end up 0
  88   __ movptr(rdx, Address(rsp, rax, Address::times_1, 2*wordSize));
  89                                             // obj, notice rax, is 0.
  90                                             // rdx is data dependent on rcx.
  91   __ movptr(rax, Address(rsp, 3*wordSize));  // jfieldID
  92 
  93   __ clear_jweak_tag(rdx);
  94 
  95   __ movptr(rdx, Address(rdx, 0));           // *obj
  96   __ shrptr (rax, 2);                         // offset
  97 
  98   assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
  99   speculative_load_pclist[count] = __ pc();
 100   switch (type) {
 101     case T_BOOLEAN: __ movzbl (rax, Address(rdx, rax, Address::times_1)); break;
 102     case T_BYTE:    __ movsbl (rax, Address(rdx, rax, Address::times_1)); break;
 103     case T_CHAR:    __ movzwl (rax, Address(rdx, rax, Address::times_1)); break;
 104     case T_SHORT:   __ movswl (rax, Address(rdx, rax, Address::times_1)); break;
 105     case T_INT:     __ movl   (rax, Address(rdx, rax, Address::times_1)); break;
 106     default:        ShouldNotReachHere();
 107   }
 108 
 109   Address ca1;
 110   __ lea(rdx, counter);
 111   __ xorptr(rdx, rax);
 112   __ xorptr(rdx, rax);
 113   __ cmp32(rcx, Address(rdx, 0));
 114   // ca1 is the same as ca because
 115   // rax, ^ counter_addr ^ rax, = address
 116   // ca1 is data dependent on rax,.
 117   __ jcc (Assembler::notEqual, slow);
 118 
 119 #ifndef _WINDOWS
 120   __ ret (0);
 121 #else
 122   // __stdcall calling convention
 123   __ ret (3*wordSize);
 124 #endif
 125 
 126   slowcase_entry_pclist[count++] = __ pc();
 127   __ bind (slow);
 128   address slow_case_addr = NULL;
 129   switch (type) {
 130     case T_BOOLEAN: slow_case_addr = jni_GetBooleanField_addr(); break;
 131     case T_BYTE:    slow_case_addr = jni_GetByteField_addr();    break;
 132     case T_CHAR:    slow_case_addr = jni_GetCharField_addr();    break;
 133     case T_SHORT:   slow_case_addr = jni_GetShortField_addr();   break;
 134     case T_INT:     slow_case_addr = jni_GetIntField_addr();     break;
 135     default:        ShouldNotReachHere();
 136   }
 137   // tail call
 138   __ jump (ExternalAddress(slow_case_addr));
 139 
 140   __ flush ();
 141 
 142 #ifndef _WINDOWS
 143   return fast_entry;
 144 #else
 145   switch (type) {
 146   case T_BOOLEAN: jni_fast_GetBooleanField_fp = (GetBooleanField_t) fast_entry; break;
 147   case T_BYTE:    jni_fast_GetByteField_fp    = (GetByteField_t)    fast_entry; break;
 148   case T_CHAR:    jni_fast_GetCharField_fp    = (GetCharField_t)    fast_entry; break;
 149   case T_SHORT:   jni_fast_GetShortField_fp   = (GetShortField_t)   fast_entry; break;
 150   case T_INT:     jni_fast_GetIntField_fp     = (GetIntField_t)     fast_entry; break;
 151   }
 152   return os::win32::fast_jni_accessor_wrapper(type);
 153 #endif
 154 }
 155 
 156 address JNI_FastGetField::generate_fast_get_boolean_field() {
 157   return generate_fast_get_int_field0(T_BOOLEAN);
 158 }
 159 
 160 address JNI_FastGetField::generate_fast_get_byte_field() {
 161   return generate_fast_get_int_field0(T_BYTE);
 162 }
 163 
 164 address JNI_FastGetField::generate_fast_get_char_field() {
 165   return generate_fast_get_int_field0(T_CHAR);
 166 }
 167 
 168 address JNI_FastGetField::generate_fast_get_short_field() {
 169   return generate_fast_get_int_field0(T_SHORT);
 170 }
 171 
 172 address JNI_FastGetField::generate_fast_get_int_field() {
 173   return generate_fast_get_int_field0(T_INT);
 174 }
 175 
 176 address JNI_FastGetField::generate_fast_get_long_field() {
 177   const char *name = "jni_fast_GetLongField";
 178   ResourceMark rm;
 179   BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE*wordSize);
 180   CodeBuffer cbuf(blob);
 181   MacroAssembler* masm = new MacroAssembler(&cbuf);
 182   address fast_entry = __ pc();
 183 
 184   Label slow;
 185 
 186   // stack layout:    offset from rsp (in words):
 187   //  old rsi          0
 188   //  return pc        1
 189   //  jni env          2
 190   //  obj              3
 191   //  jfieldID         4
 192 
 193   ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
 194 
 195   __ push  (rsi);
 196   __ mov32 (rcx, counter);
 197   __ testb (rcx, 1);
 198   __ jcc (Assembler::notZero, slow);
 199 
 200   if (JvmtiExport::can_post_field_access()) {
 201     // Check to see if a field access watch has been set before we
 202     // take the fast path.
 203     __ cmp32(ExternalAddress((address) JvmtiExport::get_field_access_count_addr()), 0);
 204     __ jcc(Assembler::notZero, slow);
 205   }
 206 
 207   __ mov(rax, rcx);
 208   __ andptr(rax, 1);                         // rax, must end up 0
 209   __ movptr(rdx, Address(rsp, rax, Address::times_1, 3*wordSize));
 210                                             // obj, notice rax, is 0.
 211                                             // rdx is data dependent on rcx.
 212   __ movptr(rsi, Address(rsp, 4*wordSize));  // jfieldID
 213 
 214   __ clear_jweak_tag(rdx);
 215 
 216   __ movptr(rdx, Address(rdx, 0));           // *obj
 217   __ shrptr(rsi, 2);                         // offset
 218 
 219   assert(count < LIST_CAPACITY-1, "LIST_CAPACITY too small");
 220   speculative_load_pclist[count++] = __ pc();
 221   __ movptr(rax, Address(rdx, rsi, Address::times_1));
 222 #ifndef _LP64
 223   speculative_load_pclist[count] = __ pc();
 224   __ movl(rdx, Address(rdx, rsi, Address::times_1, 4));
 225 #endif // _LP64
 226 
 227   __ lea(rsi, counter);
 228   __ xorptr(rsi, rdx);
 229   __ xorptr(rsi, rax);
 230   __ xorptr(rsi, rdx);
 231   __ xorptr(rsi, rax);
 232   __ cmp32(rcx, Address(rsi, 0));
 233   // ca1 is the same as ca because
 234   // rax, ^ rdx ^ counter_addr ^ rax, ^ rdx = address
 235   // ca1 is data dependent on both rax, and rdx.
 236   __ jcc (Assembler::notEqual, slow);
 237 
 238   __ pop (rsi);
 239 
 240 #ifndef _WINDOWS
 241   __ ret (0);
 242 #else
 243   // __stdcall calling convention
 244   __ ret (3*wordSize);
 245 #endif
 246 
 247   slowcase_entry_pclist[count-1] = __ pc();
 248   slowcase_entry_pclist[count++] = __ pc();
 249   __ bind (slow);
 250   __ pop  (rsi);
 251   address slow_case_addr = jni_GetLongField_addr();;
 252   // tail call
 253   __ jump (ExternalAddress(slow_case_addr));
 254 
 255   __ flush ();
 256 
 257 #ifndef _WINDOWS
 258   return fast_entry;
 259 #else
 260   jni_fast_GetLongField_fp = (GetLongField_t) fast_entry;
 261   return os::win32::fast_jni_accessor_wrapper(T_LONG);
 262 #endif
 263 }
 264 
 265 address JNI_FastGetField::generate_fast_get_float_field0(BasicType type) {
 266   const char *name = NULL;
 267   switch (type) {
 268     case T_FLOAT:  name = "jni_fast_GetFloatField";  break;
 269     case T_DOUBLE: name = "jni_fast_GetDoubleField"; break;
 270     default:       ShouldNotReachHere();
 271   }
 272   ResourceMark rm;
 273   BufferBlob* blob = BufferBlob::create(name, BUFFER_SIZE*wordSize);
 274   CodeBuffer cbuf(blob);
 275   MacroAssembler* masm = new MacroAssembler(&cbuf);
 276   address fast_entry = __ pc();
 277 
 278   Label slow_with_pop, slow;
 279 
 280   // stack layout:    offset from rsp (in words):
 281   //  return pc        0
 282   //  jni env          1
 283   //  obj              2
 284   //  jfieldID         3
 285 
 286   ExternalAddress counter(SafepointSynchronize::safepoint_counter_addr());
 287 
 288   __ mov32 (rcx, counter);
 289   __ testb (rcx, 1);
 290   __ jcc (Assembler::notZero, slow);
 291 
 292   if (JvmtiExport::can_post_field_access()) {
 293     // Check to see if a field access watch has been set before we
 294     // take the fast path.
 295     __ cmp32(ExternalAddress((address) JvmtiExport::get_field_access_count_addr()), 0);
 296     __ jcc(Assembler::notZero, slow);
 297   }
 298 
 299   __ mov(rax, rcx);
 300   __ andptr(rax, 1);                         // rax, must end up 0
 301   __ movptr(rdx, Address(rsp, rax, Address::times_1, 2*wordSize));
 302                                             // obj, notice rax, is 0.
 303                                             // rdx is data dependent on rcx.
 304   __ movptr(rax, Address(rsp, 3*wordSize));  // jfieldID
 305 
 306   __ clear_jweak_tag(rdx);
 307 
 308   __ movptr(rdx, Address(rdx, 0));           // *obj
 309   __ shrptr(rax, 2);                         // offset
 310 
 311   assert(count < LIST_CAPACITY, "LIST_CAPACITY too small");
 312   speculative_load_pclist[count] = __ pc();
 313   switch (type) {
 314 #ifndef _LP64
 315     case T_FLOAT:  __ fld_s (Address(rdx, rax, Address::times_1)); break;
 316     case T_DOUBLE: __ fld_d (Address(rdx, rax, Address::times_1)); break;
 317 #else
 318     case T_FLOAT:  __ movflt (xmm0, Address(robj, roffset, Address::times_1)); break;
 319     case T_DOUBLE: __ movdbl (xmm0, Address(robj, roffset, Address::times_1)); break;
 320 #endif // _LP64
 321     default:       ShouldNotReachHere();
 322   }
 323 
 324   Address ca1;
 325   __ fst_s (Address(rsp, -4));
 326   __ lea(rdx, counter);
 327   __ movl (rax, Address(rsp, -4));
 328   // garbage hi-order bits on 64bit are harmless.
 329   __ xorptr(rdx, rax);
 330   __ xorptr(rdx, rax);
 331   __ cmp32(rcx, Address(rdx, 0));
 332   // rax, ^ counter_addr ^ rax, = address
 333   // ca1 is data dependent on the field
 334   // access.
 335   __ jcc (Assembler::notEqual, slow_with_pop);
 336 
 337 #ifndef _WINDOWS
 338   __ ret (0);
 339 #else
 340   // __stdcall calling convention
 341   __ ret (3*wordSize);
 342 #endif
 343 
 344   __ bind (slow_with_pop);
 345   // invalid load. pop FPU stack.
 346   __ fstp_d (0);
 347 
 348   slowcase_entry_pclist[count++] = __ pc();
 349   __ bind (slow);
 350   address slow_case_addr = NULL;
 351   switch (type) {
 352     case T_FLOAT:  slow_case_addr = jni_GetFloatField_addr();  break;
 353     case T_DOUBLE: slow_case_addr = jni_GetDoubleField_addr(); break;
 354     default:       ShouldNotReachHere();
 355   }
 356   // tail call
 357   __ jump (ExternalAddress(slow_case_addr));
 358 
 359   __ flush ();
 360 
 361 #ifndef _WINDOWS
 362   return fast_entry;
 363 #else
 364   switch (type) {
 365   case T_FLOAT:  jni_fast_GetFloatField_fp  = (GetFloatField_t)  fast_entry; break;
 366   case T_DOUBLE: jni_fast_GetDoubleField_fp = (GetDoubleField_t) fast_entry; break;
 367   }
 368   return os::win32::fast_jni_accessor_wrapper(type);
 369 #endif
 370 }
 371 
 372 address JNI_FastGetField::generate_fast_get_float_field() {
 373   return generate_fast_get_float_field0(T_FLOAT);
 374 }
 375 
 376 address JNI_FastGetField::generate_fast_get_double_field() {
 377   return generate_fast_get_float_field0(T_DOUBLE);
 378 }