Source/JavaScriptCore/jit/JITPropertyAccess.cpp

   1 /*
   2  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #include "config.h"
  27
  28 #if ENABLE(JIT)
  29 #include "JIT.h"
  30
  31 #include "CodeBlock.h"
  32 #include "GetterSetter.h"
  33 #include "JITInlineMethods.h"
  34 #include "JITStubCall.h"
  35 #include "JSArray.h"
  36 #include "JSFunction.h"
  37 #include "JSPropertyNameIterator.h"
  38 #include "Interpreter.h"
  39 #include "LinkBuffer.h"
  40 #include "RepatchBuffer.h"
  41 #include "ResultType.h"
  42 #include "SamplingTool.h"
  43
  44 #ifndef NDEBUG
  45 #include <stdio.h>
  46 #endif
  47
  48 using namespace std;
  49
  50 namespace JSC {
  51 #if USE(JSVALUE64)
  52
  53 JIT::CodeRef JIT::stringGetByValStubGenerator(JSGlobalData* globalData)
  54 {
  55     JSInterfaceJIT jit;
  56     JumpList failures;
  57     failures.append(jit.branchPtr(NotEqual, Address(regT0), TrustedImmPtr(globalData->jsStringVPtr)));
  58
  59     // Load string length to regT2, and start the process of loading the data pointer into regT0
  60     jit.load32(Address(regT0, ThunkHelpers::jsStringLengthOffset()), regT2);
  61     jit.loadPtr(Address(regT0, ThunkHelpers::jsStringValueOffset()), regT0);
  62     failures.append(jit.branchTest32(Zero, regT0));
  63
  64     // Do an unsigned compare to simultaneously filter negative indices as well as indices that are too large
  65     failures.append(jit.branch32(AboveOrEqual, regT1, regT2));
  66
  67     // Load the character
  68     JumpList is16Bit;
  69     JumpList cont8Bit;
  70     // Load the string flags
  71     jit.loadPtr(Address(regT0, ThunkHelpers::stringImplFlagsOffset()), regT2);
  72     jit.loadPtr(Address(regT0, ThunkHelpers::stringImplDataOffset()), regT0);
  73     is16Bit.append(jit.branchTest32(Zero, regT2, TrustedImm32(ThunkHelpers::stringImpl8BitFlag())));
  74     jit.load8(BaseIndex(regT0, regT1, TimesOne, 0), regT0);
  75     cont8Bit.append(jit.jump());
  76     is16Bit.link(&jit);
  77     jit.load16(BaseIndex(regT0, regT1, TimesTwo, 0), regT0);
  78     cont8Bit.link(&jit);
  79
  80     failures.append(jit.branch32(AboveOrEqual, regT0, TrustedImm32(0x100)));
  81     jit.move(TrustedImmPtr(globalData->smallStrings.singleCharacterStrings()), regT1);
  82     jit.loadPtr(BaseIndex(regT1, regT0, ScalePtr, 0), regT0);
  83     jit.ret();
  84
  85     failures.link(&jit);
  86     jit.move(TrustedImm32(0), regT0);
  87     jit.ret();
  88
  89     LinkBuffer patchBuffer(*globalData, &jit);
  90     return patchBuffer.finalizeCode();
  91 }
  92
  93 void JIT::emit_op_get_by_val(Instruction* currentInstruction)
  94 {
  95     unsigned dst = currentInstruction[1].u.operand;
  96     unsigned base = currentInstruction[2].u.operand;
  97     unsigned property = currentInstruction[3].u.operand;
  98
  99     emitGetVirtualRegisters(base, regT0, property, regT1);
 100     emitJumpSlowCaseIfNotImmediateInteger(regT1);
 101
 102     // This is technically incorrect - we're zero-extending an int32.  On the hot path this doesn't matter.
 103     // We check the value as if it was a uint32 against the m_vectorLength - which will always fail if
 104     // number was signed since m_vectorLength is always less than intmax (since the total allocation
 105     // size is always less than 4Gb).  As such zero extending wil have been correct (and extending the value
 106     // to 64-bits is necessary since it's used in the address calculation.  We zero extend rather than sign
 107     // extending since it makes it easier to re-tag the value in the slow case.
 108     zeroExtend32ToPtr(regT1, regT1);
 109
 110     emitJumpSlowCaseIfNotJSCell(regT0, base);
 111     addSlowCase(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsArrayVPtr)));
 112
 113     loadPtr(Address(regT0, JSArray::storageOffset()), regT2);
 114     addSlowCase(branch32(AboveOrEqual, regT1, Address(regT0, JSArray::vectorLengthOffset())));
 115
 116     loadPtr(BaseIndex(regT2, regT1, ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])), regT0);
 117     addSlowCase(branchTestPtr(Zero, regT0));
 118
 119     emitValueProfilingSite(FirstProfilingSite);
 120     emitPutVirtualRegister(dst);
 121 }
 122
 123 void JIT::emitSlow_op_get_by_val(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 124 {
 125     unsigned dst = currentInstruction[1].u.operand;
 126     unsigned base = currentInstruction[2].u.operand;
 127     unsigned property = currentInstruction[3].u.operand;
 128
 129     linkSlowCase(iter); // property int32 check
 130     linkSlowCaseIfNotJSCell(iter, base); // base cell check
 131     Jump nonCell = jump();
 132     linkSlowCase(iter); // base array check
 133     Jump notString = branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsStringVPtr));
 134     emitNakedCall(CodeLocationLabel(m_globalData->getCTIStub(stringGetByValStubGenerator).code()));
 135     Jump failed = branchTestPtr(Zero, regT0);
 136     emitPutVirtualRegister(dst, regT0);
 137     emitJumpSlowToHot(jump(), OPCODE_LENGTH(op_get_by_val));
 138     failed.link(this);
 139     notString.link(this);
 140     nonCell.link(this);
 141
 142     linkSlowCase(iter); // vector length check
 143     linkSlowCase(iter); // empty value
 144
 145     JITStubCall stubCall(this, cti_op_get_by_val);
 146     stubCall.addArgument(base, regT2);
 147     stubCall.addArgument(property, regT2);
 148     stubCall.call(dst);
 149
 150     emitValueProfilingSite(SubsequentProfilingSite);
 151 }
 152
 153 void JIT::compileGetDirectOffset(RegisterID base, RegisterID result, RegisterID offset, RegisterID scratch)
 154 {
 155     loadPtr(Address(base, JSObject::offsetOfPropertyStorage()), scratch);
 156     loadPtr(BaseIndex(scratch, offset, ScalePtr, 0), result);
 157 }
 158
 159 void JIT::emit_op_get_by_pname(Instruction* currentInstruction)
 160 {
 161     unsigned dst = currentInstruction[1].u.operand;
 162     unsigned base = currentInstruction[2].u.operand;
 163     unsigned property = currentInstruction[3].u.operand;
 164     unsigned expected = currentInstruction[4].u.operand;
 165     unsigned iter = currentInstruction[5].u.operand;
 166     unsigned i = currentInstruction[6].u.operand;
 167
 168     emitGetVirtualRegister(property, regT0);
 169     addSlowCase(branchPtr(NotEqual, regT0, addressFor(expected)));
 170     emitGetVirtualRegisters(base, regT0, iter, regT1);
 171     emitJumpSlowCaseIfNotJSCell(regT0, base);
 172
 173     // Test base's structure
 174     loadPtr(Address(regT0, JSCell::structureOffset()), regT2);
 175     addSlowCase(branchPtr(NotEqual, regT2, Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_cachedStructure))));
 176     load32(addressFor(i), regT3);
 177     sub32(TrustedImm32(1), regT3);
 178     addSlowCase(branch32(AboveOrEqual, regT3, Address(regT1, OBJECT_OFFSETOF(JSPropertyNameIterator, m_numCacheableSlots))));
 179     compileGetDirectOffset(regT0, regT0, regT3, regT1);
 180
 181     emitPutVirtualRegister(dst, regT0);
 182 }
 183
 184 void JIT::emitSlow_op_get_by_pname(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 185 {
 186     unsigned dst = currentInstruction[1].u.operand;
 187     unsigned base = currentInstruction[2].u.operand;
 188     unsigned property = currentInstruction[3].u.operand;
 189
 190     linkSlowCase(iter);
 191     linkSlowCaseIfNotJSCell(iter, base);
 192     linkSlowCase(iter);
 193     linkSlowCase(iter);
 194
 195     JITStubCall stubCall(this, cti_op_get_by_val);
 196     stubCall.addArgument(base, regT2);
 197     stubCall.addArgument(property, regT2);
 198     stubCall.call(dst);
 199 }
 200
 201 void JIT::emit_op_put_by_val(Instruction* currentInstruction)
 202 {
 203     unsigned base = currentInstruction[1].u.operand;
 204     unsigned property = currentInstruction[2].u.operand;
 205     unsigned value = currentInstruction[3].u.operand;
 206
 207     emitGetVirtualRegisters(base, regT0, property, regT1);
 208     emitJumpSlowCaseIfNotImmediateInteger(regT1);
 209     // See comment in op_get_by_val.
 210     zeroExtend32ToPtr(regT1, regT1);
 211     emitJumpSlowCaseIfNotJSCell(regT0, base);
 212     addSlowCase(branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsArrayVPtr)));
 213     addSlowCase(branch32(AboveOrEqual, regT1, Address(regT0, JSArray::vectorLengthOffset())));
 214
 215     loadPtr(Address(regT0, JSArray::storageOffset()), regT2);
 216     Jump empty = branchTestPtr(Zero, BaseIndex(regT2, regT1, ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])));
 217
 218     Label storeResult(this);
 219     emitGetVirtualRegister(value, regT3);
 220     storePtr(regT3, BaseIndex(regT2, regT1, ScalePtr, OBJECT_OFFSETOF(ArrayStorage, m_vector[0])));
 221     Jump end = jump();
 222
 223     empty.link(this);
 224     add32(TrustedImm32(1), Address(regT2, OBJECT_OFFSETOF(ArrayStorage, m_numValuesInVector)));
 225     branch32(Below, regT1, Address(regT2, OBJECT_OFFSETOF(ArrayStorage, m_length))).linkTo(storeResult, this);
 226
 227     add32(TrustedImm32(1), regT1);
 228     store32(regT1, Address(regT2, OBJECT_OFFSETOF(ArrayStorage, m_length)));
 229     sub32(TrustedImm32(1), regT1);
 230     jump().linkTo(storeResult, this);
 231
 232     end.link(this);
 233
 234     emitWriteBarrier(regT0, regT3, regT1, regT3, ShouldFilterImmediates, WriteBarrierForPropertyAccess);
 235 }
 236
 237 void JIT::emitSlow_op_put_by_val(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 238 {
 239     unsigned base = currentInstruction[1].u.operand;
 240     unsigned property = currentInstruction[2].u.operand;
 241     unsigned value = currentInstruction[3].u.operand;
 242
 243     linkSlowCase(iter); // property int32 check
 244     linkSlowCaseIfNotJSCell(iter, base); // base cell check
 245     linkSlowCase(iter); // base not array check
 246     linkSlowCase(iter); // in vector check
 247
 248     JITStubCall stubPutByValCall(this, cti_op_put_by_val);
 249     stubPutByValCall.addArgument(regT0);
 250     stubPutByValCall.addArgument(property, regT2);
 251     stubPutByValCall.addArgument(value, regT2);
 252     stubPutByValCall.call();
 253 }
 254
 255 void JIT::emit_op_put_by_index(Instruction* currentInstruction)
 256 {
 257     JITStubCall stubCall(this, cti_op_put_by_index);
 258     stubCall.addArgument(currentInstruction[1].u.operand, regT2);
 259     stubCall.addArgument(TrustedImm32(currentInstruction[2].u.operand));
 260     stubCall.addArgument(currentInstruction[3].u.operand, regT2);
 261     stubCall.call();
 262 }
 263
 264 void JIT::emit_op_put_getter(Instruction* currentInstruction)
 265 {
 266     JITStubCall stubCall(this, cti_op_put_getter);
 267     stubCall.addArgument(currentInstruction[1].u.operand, regT2);
 268     stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
 269     stubCall.addArgument(currentInstruction[3].u.operand, regT2);
 270     stubCall.call();
 271 }
 272
 273 void JIT::emit_op_put_setter(Instruction* currentInstruction)
 274 {
 275     JITStubCall stubCall(this, cti_op_put_setter);
 276     stubCall.addArgument(currentInstruction[1].u.operand, regT2);
 277     stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[2].u.operand)));
 278     stubCall.addArgument(currentInstruction[3].u.operand, regT2);
 279     stubCall.call();
 280 }
 281
 282 void JIT::emit_op_del_by_id(Instruction* currentInstruction)
 283 {
 284     JITStubCall stubCall(this, cti_op_del_by_id);
 285     stubCall.addArgument(currentInstruction[2].u.operand, regT2);
 286     stubCall.addArgument(TrustedImmPtr(&m_codeBlock->identifier(currentInstruction[3].u.operand)));
 287     stubCall.call(currentInstruction[1].u.operand);
 288 }
 289
 290 void JIT::emit_op_method_check(Instruction* currentInstruction)
 291 {
 292     // Assert that the following instruction is a get_by_id.
 293     ASSERT(m_interpreter->getOpcodeID((currentInstruction + OPCODE_LENGTH(op_method_check))->u.opcode) == op_get_by_id);
 294
 295     currentInstruction += OPCODE_LENGTH(op_method_check);
 296     unsigned resultVReg = currentInstruction[1].u.operand;
 297     unsigned baseVReg = currentInstruction[2].u.operand;
 298     Identifier* ident = &(m_codeBlock->identifier(currentInstruction[3].u.operand));
 299
 300     emitGetVirtualRegister(baseVReg, regT0);
 301
 302     // Do the method check - check the object & its prototype's structure inline (this is the common case).
 303     m_methodCallCompilationInfo.append(MethodCallCompilationInfo(m_bytecodeOffset, m_propertyAccessCompilationInfo.size()));
 304     MethodCallCompilationInfo& info = m_methodCallCompilationInfo.last();
 305
 306     Jump notCell = emitJumpIfNotJSCell(regT0);
 307
 308     BEGIN_UNINTERRUPTED_SEQUENCE(sequenceMethodCheck);
 309
 310     Jump structureCheck = branchPtrWithPatch(NotEqual, Address(regT0, JSCell::structureOffset()), info.structureToCompare, TrustedImmPtr(reinterpret_cast<void*>(patchGetByIdDefaultStructure)));
 311     DataLabelPtr protoStructureToCompare, protoObj = moveWithPatch(TrustedImmPtr(0), regT1);
 312     Jump protoStructureCheck = branchPtrWithPatch(NotEqual, Address(regT1, JSCell::structureOffset()), protoStructureToCompare, TrustedImmPtr(reinterpret_cast<void*>(patchGetByIdDefaultStructure)));
 313
 314     // This will be relinked to load the function without doing a load.
 315     DataLabelPtr putFunction = moveWithPatch(TrustedImmPtr(0), regT0);
 316
 317     END_UNINTERRUPTED_SEQUENCE(sequenceMethodCheck);
 318
 319     Jump match = jump();
 320
 321     ASSERT_JIT_OFFSET_UNUSED(protoObj, differenceBetween(info.structureToCompare, protoObj), patchOffsetMethodCheckProtoObj);
 322     ASSERT_JIT_OFFSET(differenceBetween(info.structureToCompare, protoStructureToCompare), patchOffsetMethodCheckProtoStruct);
 323     ASSERT_JIT_OFFSET_UNUSED(putFunction, differenceBetween(info.structureToCompare, putFunction), patchOffsetMethodCheckPutFunction);
 324
 325     // Link the failure cases here.
 326     notCell.link(this);
 327     structureCheck.link(this);
 328     protoStructureCheck.link(this);
 329
 330     // Do a regular(ish) get_by_id (the slow case will be link to
 331     // cti_op_get_by_id_method_check instead of cti_op_get_by_id.
 332     compileGetByIdHotPath(baseVReg, ident);
 333
 334     match.link(this);
 335     emitValueProfilingSite(FirstProfilingSite);
 336     emitPutVirtualRegister(resultVReg);
 337
 338     // We've already generated the following get_by_id, so make sure it's skipped over.
 339     m_bytecodeOffset += OPCODE_LENGTH(op_get_by_id);
 340 }
 341
 342 void JIT::emitSlow_op_method_check(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 343 {
 344     currentInstruction += OPCODE_LENGTH(op_method_check);
 345     unsigned resultVReg = currentInstruction[1].u.operand;
 346     unsigned baseVReg = currentInstruction[2].u.operand;
 347     Identifier* ident = &(m_codeBlock->identifier(currentInstruction[3].u.operand));
 348
 349     compileGetByIdSlowCase(resultVReg, baseVReg, ident, iter, true);
 350     emitValueProfilingSite(SubsequentProfilingSite);
 351
 352     // We've already generated the following get_by_id, so make sure it's skipped over.
 353     m_bytecodeOffset += OPCODE_LENGTH(op_get_by_id);
 354 }
 355
 356 void JIT::emit_op_get_by_id(Instruction* currentInstruction)
 357 {
 358     unsigned resultVReg = currentInstruction[1].u.operand;
 359     unsigned baseVReg = currentInstruction[2].u.operand;
 360     Identifier* ident = &(m_codeBlock->identifier(currentInstruction[3].u.operand));
 361
 362     emitGetVirtualRegister(baseVReg, regT0);
 363     compileGetByIdHotPath(baseVReg, ident);
 364     emitValueProfilingSite(FirstProfilingSite);
 365     emitPutVirtualRegister(resultVReg);
 366 }
 367
 368 void JIT::compileGetByIdHotPath(int baseVReg, Identifier*)
 369 {
 370     // As for put_by_id, get_by_id requires the offset of the Structure and the offset of the access to be patched.
 371     // Additionally, for get_by_id we need patch the offset of the branch to the slow case (we patch this to jump
 372     // to array-length / prototype access tranpolines, and finally we also the the property-map access offset as a label
 373     // to jump back to if one of these trampolies finds a match.
 374
 375     emitJumpSlowCaseIfNotJSCell(regT0, baseVReg);
 376
 377     BEGIN_UNINTERRUPTED_SEQUENCE(sequenceGetByIdHotPath);
 378
 379     Label hotPathBegin(this);
 380     m_propertyAccessCompilationInfo.append(PropertyStubCompilationInfo());
 381     m_propertyAccessCompilationInfo.last().bytecodeIndex = m_bytecodeOffset;
 382     m_propertyAccessCompilationInfo.last().hotPathBegin = hotPathBegin;
 383
 384     DataLabelPtr structureToCompare;
 385     Jump structureCheck = branchPtrWithPatch(NotEqual, Address(regT0, JSCell::structureOffset()), structureToCompare, TrustedImmPtr(reinterpret_cast<void*>(patchGetByIdDefaultStructure)));
 386     addSlowCase(structureCheck);
 387     ASSERT_JIT_OFFSET(differenceBetween(hotPathBegin, structureToCompare), patchOffsetGetByIdStructure);
 388     ASSERT_JIT_OFFSET(differenceBetween(hotPathBegin, structureCheck), patchOffsetGetByIdBranchToSlowCase)
 389
 390     loadPtr(Address(regT0, JSObject::offsetOfPropertyStorage()), regT0);
 391     DataLabelCompact displacementLabel = loadPtrWithCompactAddressOffsetPatch(Address(regT0, patchGetByIdDefaultOffset), regT0);
 392     ASSERT_JIT_OFFSET_UNUSED(displacementLabel, differenceBetween(hotPathBegin, displacementLabel), patchOffsetGetByIdPropertyMapOffset);
 393
 394     Label putResult(this);
 395
 396     END_UNINTERRUPTED_SEQUENCE(sequenceGetByIdHotPath);
 397
 398     ASSERT_JIT_OFFSET(differenceBetween(hotPathBegin, putResult), patchOffsetGetByIdPutResult);
 399 }
 400
 401 void JIT::emitSlow_op_get_by_id(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 402 {
 403     unsigned resultVReg = currentInstruction[1].u.operand;
 404     unsigned baseVReg = currentInstruction[2].u.operand;
 405     Identifier* ident = &(m_codeBlock->identifier(currentInstruction[3].u.operand));
 406
 407     compileGetByIdSlowCase(resultVReg, baseVReg, ident, iter, false);
 408     emitValueProfilingSite(SubsequentProfilingSite);
 409 }
 410
 411 void JIT::compileGetByIdSlowCase(int resultVReg, int baseVReg, Identifier* ident, Vector<SlowCaseEntry>::iterator& iter, bool isMethodCheck)
 412 {
 413     // As for the hot path of get_by_id, above, we ensure that we can use an architecture specific offset
 414     // so that we only need track one pointer into the slow case code - we track a pointer to the location
 415     // of the call (which we can use to look up the patch information), but should a array-length or
 416     // prototype access trampoline fail we want to bail out back to here.  To do so we can subtract back
 417     // the distance from the call to the head of the slow case.
 418
 419     linkSlowCaseIfNotJSCell(iter, baseVReg);
 420     linkSlowCase(iter);
 421
 422     BEGIN_UNINTERRUPTED_SEQUENCE(sequenceGetByIdSlowCase);
 423
 424 #ifndef NDEBUG
 425     Label coldPathBegin(this);
 426 #endif
 427     JITStubCall stubCall(this, isMethodCheck ? cti_op_get_by_id_method_check : cti_op_get_by_id);
 428     stubCall.addArgument(regT0);
 429     stubCall.addArgument(TrustedImmPtr(ident));
 430     Call call = stubCall.call(resultVReg);
 431
 432     END_UNINTERRUPTED_SEQUENCE(sequenceGetByIdSlowCase);
 433
 434     ASSERT_JIT_OFFSET(differenceBetween(coldPathBegin, call), patchOffsetGetByIdSlowCaseCall);
 435
 436     // Track the location of the call; this will be used to recover patch information.
 437     m_propertyAccessCompilationInfo[m_propertyAccessInstructionIndex++].callReturnLocation = call;
 438 }
 439
 440 void JIT::emit_op_put_by_id(Instruction* currentInstruction)
 441 {
 442     unsigned baseVReg = currentInstruction[1].u.operand;
 443     unsigned valueVReg = currentInstruction[3].u.operand;
 444
 445     // In order to be able to patch both the Structure, and the object offset, we store one pointer,
 446     // to just after the arguments have been loaded into registers 'hotPathBegin', and we generate code
 447     // such that the Structure & offset are always at the same distance from this.
 448
 449     emitGetVirtualRegisters(baseVReg, regT0, valueVReg, regT1);
 450
 451     // Jump to a slow case if either the base object is an immediate, or if the Structure does not match.
 452     emitJumpSlowCaseIfNotJSCell(regT0, baseVReg);
 453
 454     BEGIN_UNINTERRUPTED_SEQUENCE(sequencePutById);
 455
 456     Label hotPathBegin(this);
 457     m_propertyAccessCompilationInfo.append(PropertyStubCompilationInfo());
 458     m_propertyAccessCompilationInfo.last().bytecodeIndex = m_bytecodeOffset;
 459     m_propertyAccessCompilationInfo.last().hotPathBegin = hotPathBegin;
 460
 461     // It is important that the following instruction plants a 32bit immediate, in order that it can be patched over.
 462     DataLabelPtr structureToCompare;
 463     addSlowCase(branchPtrWithPatch(NotEqual, Address(regT0, JSCell::structureOffset()), structureToCompare, TrustedImmPtr(reinterpret_cast<void*>(patchGetByIdDefaultStructure))));
 464     ASSERT_JIT_OFFSET(differenceBetween(hotPathBegin, structureToCompare), patchOffsetPutByIdStructure);
 465
 466     loadPtr(Address(regT0, JSObject::offsetOfPropertyStorage()), regT2);
 467     DataLabel32 displacementLabel = storePtrWithAddressOffsetPatch(regT1, Address(regT2, patchPutByIdDefaultOffset));
 468
 469     END_UNINTERRUPTED_SEQUENCE(sequencePutById);
 470
 471     emitWriteBarrier(regT0, regT1, regT2, regT3, ShouldFilterImmediates, WriteBarrierForPropertyAccess);
 472
 473     ASSERT_JIT_OFFSET_UNUSED(displacementLabel, differenceBetween(hotPathBegin, displacementLabel), patchOffsetPutByIdPropertyMapOffset);
 474 }
 475
 476 void JIT::emitSlow_op_put_by_id(Instruction* currentInstruction, Vector<SlowCaseEntry>::iterator& iter)
 477 {
 478     unsigned baseVReg = currentInstruction[1].u.operand;
 479     Identifier* ident = &(m_codeBlock->identifier(currentInstruction[2].u.operand));
 480     unsigned direct = currentInstruction[8].u.operand;
 481
 482     linkSlowCaseIfNotJSCell(iter, baseVReg);
 483     linkSlowCase(iter);
 484
 485     JITStubCall stubCall(this, direct ? cti_op_put_by_id_direct : cti_op_put_by_id);
 486     stubCall.addArgument(regT0);
 487     stubCall.addArgument(TrustedImmPtr(ident));
 488     stubCall.addArgument(regT1);
 489     Call call = stubCall.call();
 490
 491     // Track the location of the call; this will be used to recover patch information.
 492     m_propertyAccessCompilationInfo[m_propertyAccessInstructionIndex++].callReturnLocation = call;
 493 }
 494
 495 // Compile a store into an object's property storage.  May overwrite the
 496 // value in objectReg.
 497 void JIT::compilePutDirectOffset(RegisterID base, RegisterID value, size_t cachedOffset)
 498 {
 499     int offset = cachedOffset * sizeof(JSValue);
 500     loadPtr(Address(base, JSObject::offsetOfPropertyStorage()), base);
 501     storePtr(value, Address(base, offset));
 502 }
 503
 504 // Compile a load from an object's property storage.  May overwrite base.
 505 void JIT::compileGetDirectOffset(RegisterID base, RegisterID result, size_t cachedOffset)
 506 {
 507     int offset = cachedOffset * sizeof(JSValue);
 508     loadPtr(Address(base, JSObject::offsetOfPropertyStorage()), result);
 509     loadPtr(Address(result, offset), result);
 510 }
 511
 512 void JIT::compileGetDirectOffset(JSObject* base, RegisterID result, size_t cachedOffset)
 513 {
 514     loadPtr(base->addressOfPropertyStorage(), result);
 515     loadPtr(Address(result, cachedOffset * sizeof(WriteBarrier<Unknown>)), result);
 516 }
 517
 518 void JIT::privateCompilePutByIdTransition(StructureStubInfo* stubInfo, Structure* oldStructure, Structure* newStructure, size_t cachedOffset, StructureChain* chain, ReturnAddressPtr returnAddress, bool direct)
 519 {
 520     JumpList failureCases;
 521     // Check eax is an object of the right Structure.
 522     failureCases.append(emitJumpIfNotJSCell(regT0));
 523     failureCases.append(branchPtr(NotEqual, Address(regT0, JSCell::structureOffset()), TrustedImmPtr(oldStructure)));
 524
 525     testPrototype(oldStructure->storedPrototype(), failureCases);
 526
 527     ASSERT(oldStructure->storedPrototype().isNull() || oldStructure->storedPrototype().asCell()->structure() == chain->head()->get());
 528
 529     // ecx = baseObject->m_structure
 530     if (!direct) {
 531         for (WriteBarrier<Structure>* it = chain->head(); *it; ++it) {
 532             ASSERT((*it)->storedPrototype().isNull() || (*it)->storedPrototype().asCell()->structure() == it[1].get());
 533             testPrototype((*it)->storedPrototype(), failureCases);
 534         }
 535     }
 536
 537     Call callTarget;
 538
 539     // emit a call only if storage realloc is needed
 540     bool willNeedStorageRealloc = oldStructure->propertyStorageCapacity() != newStructure->propertyStorageCapacity();
 541     if (willNeedStorageRealloc) {
 542         // This trampoline was called to like a JIT stub; before we can can call again we need to
 543         // remove the return address from the stack, to prevent the stack from becoming misaligned.
 544         preserveReturnAddressAfterCall(regT3);
 545
 546         JITStubCall stubCall(this, cti_op_put_by_id_transition_realloc);
 547         stubCall.skipArgument(); // base
 548         stubCall.skipArgument(); // ident
 549         stubCall.skipArgument(); // value
 550         stubCall.addArgument(TrustedImm32(oldStructure->propertyStorageCapacity()));
 551         stubCall.addArgument(TrustedImm32(newStructure->propertyStorageCapacity()));
 552         stubCall.call(regT0);
 553         emitGetJITStubArg(2, regT1);
 554
 555         restoreReturnAddressBeforeReturn(regT3);
 556     }
 557
 558     // Planting the new structure triggers the write barrier so we need
 559     // an unconditional barrier here.
 560     emitWriteBarrier(regT0, regT1, regT2, regT3, UnconditionalWriteBarrier, WriteBarrierForPropertyAccess);
 561
 562     storePtr(TrustedImmPtr(newStructure), Address(regT0, JSCell::structureOffset()));
 563     compilePutDirectOffset(regT0, regT1, cachedOffset);
 564
 565     ret();
 566
 567     ASSERT(!failureCases.empty());
 568     failureCases.link(this);
 569     restoreArgumentReferenceForTrampoline();
 570     Call failureCall = tailRecursiveCall();
 571
 572     LinkBuffer patchBuffer(*m_globalData, this);
 573
 574     patchBuffer.link(failureCall, FunctionPtr(direct ? cti_op_put_by_id_direct_fail : cti_op_put_by_id_fail));
 575
 576     if (willNeedStorageRealloc) {
 577         ASSERT(m_calls.size() == 1);
 578         patchBuffer.link(m_calls[0].from, FunctionPtr(cti_op_put_by_id_transition_realloc));
 579     }
 580
 581     stubInfo->stubRoutine = patchBuffer.finalizeCode();
 582     RepatchBuffer repatchBuffer(m_codeBlock);
 583     repatchBuffer.relinkCallerToTrampoline(returnAddress, CodeLocationLabel(stubInfo->stubRoutine.code()));
 584 }
 585
 586 void JIT::patchGetByIdSelf(CodeBlock* codeBlock, StructureStubInfo* stubInfo, Structure* structure, size_t cachedOffset, ReturnAddressPtr returnAddress)
 587 {
 588     RepatchBuffer repatchBuffer(codeBlock);
 589
 590     // We don't want to patch more than once - in future go to cti_op_get_by_id_generic.
 591     // Should probably go to cti_op_get_by_id_fail, but that doesn't do anything interesting right now.
 592     repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(cti_op_get_by_id_self_fail));
 593
 594     int offset = sizeof(JSValue) * cachedOffset;
 595
 596     // Patch the offset into the propoerty map to load from, then patch the Structure to look for.
 597     repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabelPtrAtOffset(patchOffsetGetByIdStructure), structure);
 598     repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabelCompactAtOffset(patchOffsetGetByIdPropertyMapOffset), offset);
 599 }
 600
 601 void JIT::patchPutByIdReplace(CodeBlock* codeBlock, StructureStubInfo* stubInfo, Structure* structure, size_t cachedOffset, ReturnAddressPtr returnAddress, bool direct)
 602 {
 603     RepatchBuffer repatchBuffer(codeBlock);
 604
 605     // We don't want to patch more than once - in future go to cti_op_put_by_id_generic.
 606     // Should probably go to cti_op_put_by_id_fail, but that doesn't do anything interesting right now.
 607     repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(direct ? cti_op_put_by_id_direct_generic : cti_op_put_by_id_generic));
 608
 609     int offset = sizeof(JSValue) * cachedOffset;
 610
 611     // Patch the offset into the propoerty map to load from, then patch the Structure to look for.
 612     repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabelPtrAtOffset(patchOffsetPutByIdStructure), structure);
 613     repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabel32AtOffset(patchOffsetPutByIdPropertyMapOffset), offset);
 614 }
 615
 616 void JIT::privateCompilePatchGetArrayLength(ReturnAddressPtr returnAddress)
 617 {
 618     StructureStubInfo* stubInfo = &m_codeBlock->getStubInfo(returnAddress);
 619
 620     // Check eax is an array
 621     Jump failureCases1 = branchPtr(NotEqual, Address(regT0), TrustedImmPtr(m_globalData->jsArrayVPtr));
 622
 623     // Checks out okay! - get the length from the storage
 624     loadPtr(Address(regT0, JSArray::storageOffset()), regT3);
 625     load32(Address(regT3, OBJECT_OFFSETOF(ArrayStorage, m_length)), regT2);
 626     Jump failureCases2 = branch32(LessThan, regT2, TrustedImm32(0));
 627
 628     emitFastArithIntToImmNoCheck(regT2, regT0);
 629     Jump success = jump();
 630
 631     LinkBuffer patchBuffer(*m_globalData, this);
 632
 633     // Use the patch information to link the failure cases back to the original slow case routine.
 634     CodeLocationLabel slowCaseBegin = stubInfo->callReturnLocation.labelAtOffset(-patchOffsetGetByIdSlowCaseCall);
 635     patchBuffer.link(failureCases1, slowCaseBegin);
 636     patchBuffer.link(failureCases2, slowCaseBegin);
 637
 638     // On success return back to the hot patch code, at a point it will perform the store to dest for us.
 639     patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));
 640
 641     // Track the stub we have created so that it will be deleted later.
 642     stubInfo->stubRoutine = patchBuffer.finalizeCode();
 643
 644     // Finally patch the jump to slow case back in the hot path to jump here instead.
 645     CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);
 646     RepatchBuffer repatchBuffer(m_codeBlock);
 647     repatchBuffer.relink(jumpLocation, CodeLocationLabel(stubInfo->stubRoutine.code()));
 648
 649     // We don't want to patch more than once - in future go to cti_op_put_by_id_generic.
 650     repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(cti_op_get_by_id_array_fail));
 651 }
 652
 653 void JIT::privateCompileGetByIdProto(StructureStubInfo* stubInfo, Structure* structure, Structure* prototypeStructure, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset, ReturnAddressPtr returnAddress, CallFrame* callFrame)
 654 {
 655     // The prototype object definitely exists (if this stub exists the CodeBlock is referencing a Structure that is
 656     // referencing the prototype object - let's speculatively load it's table nice and early!)
 657     JSObject* protoObject = asObject(structure->prototypeForLookup(callFrame));
 658
 659     // Check eax is an object of the right Structure.
 660     Jump failureCases1 = checkStructure(regT0, structure);
 661
 662     // Check the prototype object's Structure had not changed.
 663     move(TrustedImmPtr(protoObject), regT3);
 664     Jump failureCases2 = branchPtr(NotEqual, Address(regT3, JSCell::structureOffset()), TrustedImmPtr(prototypeStructure));
 665
 666     bool needsStubLink = false;
 667
 668     // Checks out okay!
 669     if (slot.cachedPropertyType() == PropertySlot::Getter) {
 670         needsStubLink = true;
 671         compileGetDirectOffset(protoObject, regT1, cachedOffset);
 672         JITStubCall stubCall(this, cti_op_get_by_id_getter_stub);
 673         stubCall.addArgument(regT1);
 674         stubCall.addArgument(regT0);
 675         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 676         stubCall.call();
 677     } else if (slot.cachedPropertyType() == PropertySlot::Custom) {
 678         needsStubLink = true;
 679         JITStubCall stubCall(this, cti_op_get_by_id_custom_stub);
 680         stubCall.addArgument(TrustedImmPtr(protoObject));
 681         stubCall.addArgument(TrustedImmPtr(FunctionPtr(slot.customGetter()).executableAddress()));
 682         stubCall.addArgument(TrustedImmPtr(const_cast<Identifier*>(&ident)));
 683         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 684         stubCall.call();
 685     } else
 686         compileGetDirectOffset(protoObject, regT0, cachedOffset);
 687     Jump success = jump();
 688     LinkBuffer patchBuffer(*m_globalData, this);
 689
 690     // Use the patch information to link the failure cases back to the original slow case routine.
 691     CodeLocationLabel slowCaseBegin = stubInfo->callReturnLocation.labelAtOffset(-patchOffsetGetByIdSlowCaseCall);
 692     patchBuffer.link(failureCases1, slowCaseBegin);
 693     patchBuffer.link(failureCases2, slowCaseBegin);
 694
 695     // On success return back to the hot patch code, at a point it will perform the store to dest for us.
 696     patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));
 697
 698     if (needsStubLink) {
 699         for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {
 700             if (iter->to)
 701                 patchBuffer.link(iter->from, FunctionPtr(iter->to));
 702         }
 703     }
 704     // Track the stub we have created so that it will be deleted later.
 705     stubInfo->stubRoutine = patchBuffer.finalizeCode();
 706
 707     // Finally patch the jump to slow case back in the hot path to jump here instead.
 708     CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);
 709     RepatchBuffer repatchBuffer(m_codeBlock);
 710     repatchBuffer.relink(jumpLocation, CodeLocationLabel(stubInfo->stubRoutine.code()));
 711
 712     // We don't want to patch more than once - in future go to cti_op_put_by_id_generic.
 713     repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(cti_op_get_by_id_proto_list));
 714 }
 715
 716 void JIT::privateCompileGetByIdSelfList(StructureStubInfo* stubInfo, PolymorphicAccessStructureList* polymorphicStructures, int currentIndex, Structure* structure, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset)
 717 {
 718     Jump failureCase = checkStructure(regT0, structure);
 719     bool needsStubLink = false;
 720     bool isDirect = false;
 721     if (slot.cachedPropertyType() == PropertySlot::Getter) {
 722         needsStubLink = true;
 723         compileGetDirectOffset(regT0, regT1, cachedOffset);
 724         JITStubCall stubCall(this, cti_op_get_by_id_getter_stub);
 725         stubCall.addArgument(regT1);
 726         stubCall.addArgument(regT0);
 727         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 728         stubCall.call();
 729     } else if (slot.cachedPropertyType() == PropertySlot::Custom) {
 730         needsStubLink = true;
 731         JITStubCall stubCall(this, cti_op_get_by_id_custom_stub);
 732         stubCall.addArgument(regT0);
 733         stubCall.addArgument(TrustedImmPtr(FunctionPtr(slot.customGetter()).executableAddress()));
 734         stubCall.addArgument(TrustedImmPtr(const_cast<Identifier*>(&ident)));
 735         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 736         stubCall.call();
 737     } else {
 738         isDirect = true;
 739         compileGetDirectOffset(regT0, regT0, cachedOffset);
 740     }
 741     Jump success = jump();
 742
 743     LinkBuffer patchBuffer(*m_globalData, this);
 744
 745     if (needsStubLink) {
 746         for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {
 747             if (iter->to)
 748                 patchBuffer.link(iter->from, FunctionPtr(iter->to));
 749         }
 750     }
 751
 752     // Use the patch information to link the failure cases back to the original slow case routine.
 753     CodeLocationLabel lastProtoBegin = CodeLocationLabel(polymorphicStructures->list[currentIndex - 1].stubRoutine.code());
 754     if (!lastProtoBegin)
 755         lastProtoBegin = stubInfo->callReturnLocation.labelAtOffset(-patchOffsetGetByIdSlowCaseCall);
 756
 757     patchBuffer.link(failureCase, lastProtoBegin);
 758
 759     // On success return back to the hot patch code, at a point it will perform the store to dest for us.
 760     patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));
 761
 762     MacroAssemblerCodeRef stubCode = patchBuffer.finalizeCode();
 763
 764     polymorphicStructures->list[currentIndex].set(*m_globalData, m_codeBlock->ownerExecutable(), stubCode, structure, isDirect);
 765
 766     // Finally patch the jump to slow case back in the hot path to jump here instead.
 767     CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);
 768     RepatchBuffer repatchBuffer(m_codeBlock);
 769     repatchBuffer.relink(jumpLocation, CodeLocationLabel(stubCode.code()));
 770 }
 771
 772 void JIT::privateCompileGetByIdProtoList(StructureStubInfo* stubInfo, PolymorphicAccessStructureList* prototypeStructures, int currentIndex, Structure* structure, Structure* prototypeStructure, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset, CallFrame* callFrame)
 773 {
 774     // The prototype object definitely exists (if this stub exists the CodeBlock is referencing a Structure that is
 775     // referencing the prototype object - let's speculatively load it's table nice and early!)
 776     JSObject* protoObject = asObject(structure->prototypeForLookup(callFrame));
 777
 778     // Check eax is an object of the right Structure.
 779     Jump failureCases1 = checkStructure(regT0, structure);
 780
 781     // Check the prototype object's Structure had not changed.
 782     move(TrustedImmPtr(protoObject), regT3);
 783     Jump failureCases2 = branchPtr(NotEqual, Address(regT3, JSCell::structureOffset()), TrustedImmPtr(prototypeStructure));
 784
 785     // Checks out okay!
 786     bool needsStubLink = false;
 787     bool isDirect = false;
 788     if (slot.cachedPropertyType() == PropertySlot::Getter) {
 789         needsStubLink = true;
 790         compileGetDirectOffset(protoObject, regT1, cachedOffset);
 791         JITStubCall stubCall(this, cti_op_get_by_id_getter_stub);
 792         stubCall.addArgument(regT1);
 793         stubCall.addArgument(regT0);
 794         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 795         stubCall.call();
 796     } else if (slot.cachedPropertyType() == PropertySlot::Custom) {
 797         needsStubLink = true;
 798         JITStubCall stubCall(this, cti_op_get_by_id_custom_stub);
 799         stubCall.addArgument(TrustedImmPtr(protoObject));
 800         stubCall.addArgument(TrustedImmPtr(FunctionPtr(slot.customGetter()).executableAddress()));
 801         stubCall.addArgument(TrustedImmPtr(const_cast<Identifier*>(&ident)));
 802         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 803         stubCall.call();
 804     } else {
 805         isDirect = true;
 806         compileGetDirectOffset(protoObject, regT0, cachedOffset);
 807     }
 808
 809     Jump success = jump();
 810
 811     LinkBuffer patchBuffer(*m_globalData, this);
 812
 813     if (needsStubLink) {
 814         for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {
 815             if (iter->to)
 816                 patchBuffer.link(iter->from, FunctionPtr(iter->to));
 817         }
 818     }
 819
 820     // Use the patch information to link the failure cases back to the original slow case routine.
 821     CodeLocationLabel lastProtoBegin = CodeLocationLabel(prototypeStructures->list[currentIndex - 1].stubRoutine.code());
 822     patchBuffer.link(failureCases1, lastProtoBegin);
 823     patchBuffer.link(failureCases2, lastProtoBegin);
 824
 825     // On success return back to the hot patch code, at a point it will perform the store to dest for us.
 826     patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));
 827
 828     MacroAssemblerCodeRef stubCode = patchBuffer.finalizeCode();
 829     prototypeStructures->list[currentIndex].set(*m_globalData, m_codeBlock->ownerExecutable(), stubCode, structure, prototypeStructure, isDirect);
 830
 831     // Finally patch the jump to slow case back in the hot path to jump here instead.
 832     CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);
 833     RepatchBuffer repatchBuffer(m_codeBlock);
 834     repatchBuffer.relink(jumpLocation, CodeLocationLabel(stubCode.code()));
 835 }
 836
 837 void JIT::privateCompileGetByIdChainList(StructureStubInfo* stubInfo, PolymorphicAccessStructureList* prototypeStructures, int currentIndex, Structure* structure, StructureChain* chain, size_t count, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset, CallFrame* callFrame)
 838 {
 839     ASSERT(count);
 840     JumpList bucketsOfFail;
 841
 842     // Check eax is an object of the right Structure.
 843     Jump baseObjectCheck = checkStructure(regT0, structure);
 844     bucketsOfFail.append(baseObjectCheck);
 845
 846     Structure* currStructure = structure;
 847     WriteBarrier<Structure>* it = chain->head();
 848     JSObject* protoObject = 0;
 849     for (unsigned i = 0; i < count; ++i, ++it) {
 850         protoObject = asObject(currStructure->prototypeForLookup(callFrame));
 851         currStructure = it->get();
 852         testPrototype(protoObject, bucketsOfFail);
 853     }
 854     ASSERT(protoObject);
 855
 856     bool needsStubLink = false;
 857     bool isDirect = false;
 858     if (slot.cachedPropertyType() == PropertySlot::Getter) {
 859         needsStubLink = true;
 860         compileGetDirectOffset(protoObject, regT1, cachedOffset);
 861         JITStubCall stubCall(this, cti_op_get_by_id_getter_stub);
 862         stubCall.addArgument(regT1);
 863         stubCall.addArgument(regT0);
 864         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 865         stubCall.call();
 866     } else if (slot.cachedPropertyType() == PropertySlot::Custom) {
 867         needsStubLink = true;
 868         JITStubCall stubCall(this, cti_op_get_by_id_custom_stub);
 869         stubCall.addArgument(TrustedImmPtr(protoObject));
 870         stubCall.addArgument(TrustedImmPtr(FunctionPtr(slot.customGetter()).executableAddress()));
 871         stubCall.addArgument(TrustedImmPtr(const_cast<Identifier*>(&ident)));
 872         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 873         stubCall.call();
 874     } else {
 875         isDirect = true;
 876         compileGetDirectOffset(protoObject, regT0, cachedOffset);
 877     }
 878     Jump success = jump();
 879
 880     LinkBuffer patchBuffer(*m_globalData, this);
 881
 882     if (needsStubLink) {
 883         for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {
 884             if (iter->to)
 885                 patchBuffer.link(iter->from, FunctionPtr(iter->to));
 886         }
 887     }
 888
 889     // Use the patch information to link the failure cases back to the original slow case routine.
 890     CodeLocationLabel lastProtoBegin = CodeLocationLabel(prototypeStructures->list[currentIndex - 1].stubRoutine.code());
 891
 892     patchBuffer.link(bucketsOfFail, lastProtoBegin);
 893
 894     // On success return back to the hot patch code, at a point it will perform the store to dest for us.
 895     patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));
 896
 897     CodeRef stubRoutine = patchBuffer.finalizeCode();
 898
 899     // Track the stub we have created so that it will be deleted later.
 900     prototypeStructures->list[currentIndex].set(callFrame->globalData(), m_codeBlock->ownerExecutable(), stubRoutine, structure, chain, isDirect);
 901
 902     // Finally patch the jump to slow case back in the hot path to jump here instead.
 903     CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);
 904     RepatchBuffer repatchBuffer(m_codeBlock);
 905     repatchBuffer.relink(jumpLocation, CodeLocationLabel(stubRoutine.code()));
 906 }
 907
 908 void JIT::privateCompileGetByIdChain(StructureStubInfo* stubInfo, Structure* structure, StructureChain* chain, size_t count, const Identifier& ident, const PropertySlot& slot, size_t cachedOffset, ReturnAddressPtr returnAddress, CallFrame* callFrame)
 909 {
 910     ASSERT(count);
 911
 912     JumpList bucketsOfFail;
 913
 914     // Check eax is an object of the right Structure.
 915     bucketsOfFail.append(checkStructure(regT0, structure));
 916
 917     Structure* currStructure = structure;
 918     WriteBarrier<Structure>* it = chain->head();
 919     JSObject* protoObject = 0;
 920     for (unsigned i = 0; i < count; ++i, ++it) {
 921         protoObject = asObject(currStructure->prototypeForLookup(callFrame));
 922         currStructure = it->get();
 923         testPrototype(protoObject, bucketsOfFail);
 924     }
 925     ASSERT(protoObject);
 926
 927     bool needsStubLink = false;
 928     if (slot.cachedPropertyType() == PropertySlot::Getter) {
 929         needsStubLink = true;
 930         compileGetDirectOffset(protoObject, regT1, cachedOffset);
 931         JITStubCall stubCall(this, cti_op_get_by_id_getter_stub);
 932         stubCall.addArgument(regT1);
 933         stubCall.addArgument(regT0);
 934         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 935         stubCall.call();
 936     } else if (slot.cachedPropertyType() == PropertySlot::Custom) {
 937         needsStubLink = true;
 938         JITStubCall stubCall(this, cti_op_get_by_id_custom_stub);
 939         stubCall.addArgument(TrustedImmPtr(protoObject));
 940         stubCall.addArgument(TrustedImmPtr(FunctionPtr(slot.customGetter()).executableAddress()));
 941         stubCall.addArgument(TrustedImmPtr(const_cast<Identifier*>(&ident)));
 942         stubCall.addArgument(TrustedImmPtr(stubInfo->callReturnLocation.executableAddress()));
 943         stubCall.call();
 944     } else
 945         compileGetDirectOffset(protoObject, regT0, cachedOffset);
 946     Jump success = jump();
 947
 948     LinkBuffer patchBuffer(*m_globalData, this);
 949
 950     if (needsStubLink) {
 951         for (Vector<CallRecord>::iterator iter = m_calls.begin(); iter != m_calls.end(); ++iter) {
 952             if (iter->to)
 953                 patchBuffer.link(iter->from, FunctionPtr(iter->to));
 954         }
 955     }
 956
 957     // Use the patch information to link the failure cases back to the original slow case routine.
 958     patchBuffer.link(bucketsOfFail, stubInfo->callReturnLocation.labelAtOffset(-patchOffsetGetByIdSlowCaseCall));
 959
 960     // On success return back to the hot patch code, at a point it will perform the store to dest for us.
 961     patchBuffer.link(success, stubInfo->hotPathBegin.labelAtOffset(patchOffsetGetByIdPutResult));
 962
 963     // Track the stub we have created so that it will be deleted later.
 964     CodeRef stubRoutine = patchBuffer.finalizeCode();
 965     stubInfo->stubRoutine = stubRoutine;
 966
 967     // Finally patch the jump to slow case back in the hot path to jump here instead.
 968     CodeLocationJump jumpLocation = stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase);
 969     RepatchBuffer repatchBuffer(m_codeBlock);
 970     repatchBuffer.relink(jumpLocation, CodeLocationLabel(stubRoutine.code()));
 971
 972     // We don't want to patch more than once - in future go to cti_op_put_by_id_generic.
 973     repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(cti_op_get_by_id_proto_list));
 974 }
 975
 976 void JIT::emit_op_get_scoped_var(Instruction* currentInstruction)
 977 {
 978     int skip = currentInstruction[3].u.operand;
 979
 980     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT0);
 981     bool checkTopLevel = m_codeBlock->codeType() == FunctionCode && m_codeBlock->needsFullScopeChain();
 982     ASSERT(skip || !checkTopLevel);
 983     if (checkTopLevel && skip--) {
 984         Jump activationNotCreated;
 985         if (checkTopLevel)
 986             activationNotCreated = branchTestPtr(Zero, addressFor(m_codeBlock->activationRegister()));
 987         loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, next)), regT0);
 988         activationNotCreated.link(this);
 989     }
 990     while (skip--)
 991         loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, next)), regT0);
 992
 993     loadPtr(Address(regT0, OBJECT_OFFSETOF(ScopeChainNode, object)), regT0);
 994     loadPtr(Address(regT0, JSVariableObject::offsetOfRegisters()), regT0);
 995     loadPtr(Address(regT0, currentInstruction[2].u.operand * sizeof(Register)), regT0);
 996     emitValueProfilingSite(FirstProfilingSite);
 997     emitPutVirtualRegister(currentInstruction[1].u.operand);
 998 }
 999
1000 void JIT::emit_op_put_scoped_var(Instruction* currentInstruction)
1001 {
1002     int skip = currentInstruction[2].u.operand;
1003
1004     emitGetVirtualRegister(currentInstruction[3].u.operand, regT0);
1005
1006     emitGetFromCallFrameHeaderPtr(RegisterFile::ScopeChain, regT1);
1007     bool checkTopLevel = m_codeBlock->codeType() == FunctionCode && m_codeBlock->needsFullScopeChain();
1008     ASSERT(skip || !checkTopLevel);
1009     if (checkTopLevel && skip--) {
1010         Jump activationNotCreated;
1011         if (checkTopLevel)
1012             activationNotCreated = branchTestPtr(Zero, addressFor(m_codeBlock->activationRegister()));
1013         loadPtr(Address(regT1, OBJECT_OFFSETOF(ScopeChainNode, next)), regT1);
1014         activationNotCreated.link(this);
1015     }
1016     while (skip--)
1017         loadPtr(Address(regT1, OBJECT_OFFSETOF(ScopeChainNode, next)), regT1);
1018     loadPtr(Address(regT1, OBJECT_OFFSETOF(ScopeChainNode, object)), regT1);
1019
1020     emitWriteBarrier(regT1, regT0, regT2, regT3, ShouldFilterImmediates, WriteBarrierForVariableAccess);
1021
1022     loadPtr(Address(regT1, JSVariableObject::offsetOfRegisters()), regT1);
1023     storePtr(regT0, Address(regT1, currentInstruction[1].u.operand * sizeof(Register)));
1024 }
1025
1026 void JIT::emit_op_get_global_var(Instruction* currentInstruction)
1027 {
1028     JSVariableObject* globalObject = m_codeBlock->globalObject();
1029     loadPtr(&globalObject->m_registers, regT0);
1030     loadPtr(Address(regT0, currentInstruction[2].u.operand * sizeof(Register)), regT0);
1031     emitValueProfilingSite(FirstProfilingSite);
1032     emitPutVirtualRegister(currentInstruction[1].u.operand);
1033 }
1034
1035 void JIT::emit_op_put_global_var(Instruction* currentInstruction)
1036 {
1037     JSGlobalObject* globalObject = m_codeBlock->globalObject();
1038
1039     emitGetVirtualRegister(currentInstruction[2].u.operand, regT0);
1040
1041     move(TrustedImmPtr(globalObject), regT1);
1042     loadPtr(Address(regT1, JSVariableObject::offsetOfRegisters()), regT1);
1043     storePtr(regT0, Address(regT1, currentInstruction[1].u.operand * sizeof(Register)));
1044     emitWriteBarrier(globalObject, regT0, regT2, ShouldFilterImmediates, WriteBarrierForVariableAccess);
1045 }
1046
1047 void JIT::resetPatchGetById(RepatchBuffer& repatchBuffer, StructureStubInfo* stubInfo)
1048 {
1049     repatchBuffer.relink(stubInfo->callReturnLocation, cti_op_get_by_id);
1050     repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabelPtrAtOffset(patchOffsetGetByIdStructure), reinterpret_cast<void*>(-1));
1051     repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabelCompactAtOffset(patchOffsetGetByIdPropertyMapOffset), 0);
1052     repatchBuffer.relink(stubInfo->hotPathBegin.jumpAtOffset(patchOffsetGetByIdBranchToSlowCase), stubInfo->callReturnLocation.labelAtOffset(-patchOffsetGetByIdSlowCaseCall));
1053 }
1054
1055 void JIT::resetPatchPutById(RepatchBuffer& repatchBuffer, StructureStubInfo* stubInfo)
1056 {
1057     if (isDirectPutById(stubInfo))
1058         repatchBuffer.relink(stubInfo->callReturnLocation, cti_op_put_by_id_direct);
1059     else
1060         repatchBuffer.relink(stubInfo->callReturnLocation, cti_op_put_by_id);
1061     repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabelPtrAtOffset(patchOffsetPutByIdStructure), reinterpret_cast<void*>(-1));
1062     repatchBuffer.repatch(stubInfo->hotPathBegin.dataLabelCompactAtOffset(patchOffsetPutByIdPropertyMapOffset), 0);
1063 }
1064
1065 #endif // USE(JSVALUE64)
1066
1067 void JIT::emitWriteBarrier(RegisterID owner, RegisterID value, RegisterID scratch, RegisterID scratch2, WriteBarrierMode mode, WriteBarrierUseKind useKind)
1068 {
1069     UNUSED_PARAM(owner);
1070     UNUSED_PARAM(scratch);
1071     UNUSED_PARAM(scratch2);
1072     UNUSED_PARAM(useKind);
1073     UNUSED_PARAM(value);
1074     UNUSED_PARAM(mode);
1075     ASSERT(owner != scratch);
1076     ASSERT(owner != scratch2);
1077
1078 #if ENABLE(WRITE_BARRIER_PROFILING)
1079     emitCount(WriteBarrierCounters::jitCounterFor(useKind));
1080 #endif
1081
1082 #if ENABLE(GGC)
1083     Jump filterCells;
1084     if (mode == ShouldFilterImmediates)
1085         filterCells = emitJumpIfNotJSCell(value);
1086     move(owner, scratch);
1087     andPtr(TrustedImm32(static_cast<int32_t>(MarkedBlock::blockMask)), scratch);
1088     move(owner, scratch2);
1089     // consume additional 8 bits as we're using an approximate filter
1090     rshift32(TrustedImm32(MarkedBlock::atomShift + 8), scratch2);
1091     andPtr(TrustedImm32(MarkedBlock::atomMask >> 8), scratch2);
1092     Jump filter = branchTest8(Zero, BaseIndex(scratch, scratch2, TimesOne, MarkedBlock::offsetOfMarks()));
1093     move(owner, scratch2);
1094     rshift32(TrustedImm32(MarkedBlock::cardShift), scratch2);
1095     andPtr(TrustedImm32(MarkedBlock::cardMask), scratch2);
1096     store8(TrustedImm32(1), BaseIndex(scratch, scratch2, TimesOne, MarkedBlock::offsetOfCards()));
1097     filter.link(this);
1098     if (mode == ShouldFilterImmediates)
1099         filterCells.link(this);
1100 #endif
1101 }
1102
1103 void JIT::emitWriteBarrier(JSCell* owner, RegisterID value, RegisterID scratch, WriteBarrierMode mode, WriteBarrierUseKind useKind)
1104 {
1105     UNUSED_PARAM(owner);
1106     UNUSED_PARAM(scratch);
1107     UNUSED_PARAM(useKind);
1108     UNUSED_PARAM(value);
1109     UNUSED_PARAM(mode);
1110
1111 #if ENABLE(WRITE_BARRIER_PROFILING)
1112     emitCount(WriteBarrierCounters::jitCounterFor(useKind));
1113 #endif
1114
1115 #if ENABLE(GGC)
1116     Jump filterCells;
1117     if (mode == ShouldFilterImmediates)
1118         filterCells = emitJumpIfNotJSCell(value);
1119     uint8_t* cardAddress = Heap::addressOfCardFor(owner);
1120     move(TrustedImmPtr(cardAddress), scratch);
1121     store8(TrustedImm32(1), Address(scratch));
1122     if (mode == ShouldFilterImmediates)
1123         filterCells.link(this);
1124 #endif
1125 }
1126
1127 void JIT::testPrototype(JSValue prototype, JumpList& failureCases)
1128 {
1129     if (prototype.isNull())
1130         return;
1131
1132     ASSERT(prototype.isCell());
1133     move(TrustedImmPtr(prototype.asCell()), regT3);
1134     failureCases.append(branchPtr(NotEqual, Address(regT3, JSCell::structureOffset()), TrustedImmPtr(prototype.asCell()->structure())));
1135 }
1136
1137 void JIT::patchMethodCallProto(JSGlobalData& globalData, CodeBlock* codeBlock, MethodCallLinkInfo& methodCallLinkInfo, JSObject* callee, Structure* structure, JSObject* proto, ReturnAddressPtr returnAddress)
1138 {
1139     RepatchBuffer repatchBuffer(codeBlock);
1140
1141     CodeLocationDataLabelPtr structureLocation = methodCallLinkInfo.cachedStructure.location();
1142     methodCallLinkInfo.cachedStructure.set(globalData, structureLocation, codeBlock->ownerExecutable(), structure);
1143
1144     Structure* prototypeStructure = proto->structure();
1145     methodCallLinkInfo.cachedPrototypeStructure.set(globalData, structureLocation.dataLabelPtrAtOffset(patchOffsetMethodCheckProtoStruct), codeBlock->ownerExecutable(), prototypeStructure);
1146     methodCallLinkInfo.cachedPrototype.set(globalData, structureLocation.dataLabelPtrAtOffset(patchOffsetMethodCheckProtoObj), codeBlock->ownerExecutable(), proto);
1147     methodCallLinkInfo.cachedFunction.set(globalData, structureLocation.dataLabelPtrAtOffset(patchOffsetMethodCheckPutFunction), codeBlock->ownerExecutable(), callee);
1148     repatchBuffer.relinkCallerToFunction(returnAddress, FunctionPtr(cti_op_get_by_id_method_check_update));
1149 }
1150
1151 bool JIT::isDirectPutById(StructureStubInfo* stubInfo)
1152 {
1153     switch (stubInfo->accessType) {
1154     case access_put_by_id_transition_normal:
1155         return false;
1156     case access_put_by_id_transition_direct:
1157         return true;
1158     case access_put_by_id_replace:
1159     case access_put_by_id_generic: {
1160         void* oldCall = MacroAssembler::readCallTarget(stubInfo->callReturnLocation).executableAddress();
1161         if (oldCall == bitwise_cast<void*>(cti_op_put_by_id_direct)
1162             || oldCall == bitwise_cast<void*>(cti_op_put_by_id_direct_generic)
1163             || oldCall == bitwise_cast<void*>(cti_op_put_by_id_direct_fail))
1164             return true;
1165         ASSERT(oldCall == bitwise_cast<void*>(cti_op_put_by_id)
1166                || oldCall == bitwise_cast<void*>(cti_op_put_by_id_generic)
1167                || oldCall == bitwise_cast<void*>(cti_op_put_by_id_fail));
1168         return false;
1169     }
1170     default:
1171         ASSERT_NOT_REACHED();
1172         return false;
1173     }
1174 }
1175
1176 } // namespace JSC
1177
1178 #endif // ENABLE(JIT)