root/src/x64/macro-assembler-x64.cc

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DEFINITIONS

This source file includes following definitions.
  1. root_array_available_
  2. RootRegisterDelta
  3. ExternalOperand
  4. Load
  5. Store
  6. LoadAddress
  7. LoadAddressSize
  8. PushAddress
  9. LoadRoot
  10. LoadRootIndexed
  11. StoreRoot
  12. PushRoot
  13. CompareRoot
  14. CompareRoot
  15. RememberedSetHelper
  16. InNewSpace
  17. RecordWriteField
  18. RecordWriteArray
  19. RecordWrite
  20. Assert
  21. AssertFastElements
  22. Check
  23. CheckStackAlignment
  24. NegativeZeroTest
  25. Abort
  26. CallStub
  27. TailCallStub
  28. StubReturn
  29. AllowThisStubCall
  30. IllegalOperation
  31. IndexFromHash
  32. CallRuntime
  33. CallRuntimeSaveDoubles
  34. CallRuntime
  35. CallExternalReference
  36. TailCallExternalReference
  37. TailCallRuntime
  38. Offset
  39. PrepareCallApiFunction
  40. CallApiFunctionAndReturn
  41. JumpToExternalReference
  42. InvokeBuiltin
  43. GetBuiltinFunction
  44. GetBuiltinEntry
  45. PushCallerSaved
  46. PopCallerSaved
  47. Set
  48. Set
  49. IsUnsafeInt
  50. SafeMove
  51. SafePush
  52. GetSmiConstant
  53. LoadSmiConstant
  54. Integer32ToSmi
  55. Integer32ToSmiField
  56. Integer64PlusConstantToSmi
  57. SmiToInteger32
  58. SmiToInteger32
  59. SmiToInteger64
  60. SmiToInteger64
  61. SmiTest
  62. SmiCompare
  63. SmiCompare
  64. Cmp
  65. SmiCompare
  66. SmiCompare
  67. SmiCompare
  68. Cmp
  69. SmiCompareInteger32
  70. PositiveSmiTimesPowerOfTwoToInteger64
  71. PositiveSmiDivPowerOfTwoToInteger32
  72. SmiOrIfSmis
  73. CheckSmi
  74. CheckSmi
  75. CheckNonNegativeSmi
  76. CheckBothSmi
  77. CheckBothNonNegativeSmi
  78. CheckEitherSmi
  79. CheckIsMinSmi
  80. CheckInteger32ValidSmiValue
  81. CheckUInteger32ValidSmiValue
  82. CheckSmiToIndicator
  83. CheckSmiToIndicator
  84. JumpIfNotValidSmiValue
  85. JumpIfUIntNotValidSmiValue
  86. JumpIfSmi
  87. JumpIfNotSmi
  88. JumpUnlessNonNegativeSmi
  89. JumpIfSmiEqualsConstant
  90. JumpIfNotBothSmi
  91. JumpUnlessBothNonNegativeSmi
  92. SmiTryAddConstant
  93. SmiAddConstant
  94. SmiAddConstant
  95. SmiAddConstant
  96. SmiSubConstant
  97. SmiSubConstant
  98. SmiNeg
  99. SmiAdd
  100. SmiAdd
  101. SmiAdd
  102. SmiSub
  103. SmiSub
  104. SmiSub
  105. SmiSub
  106. SmiMul
  107. SmiDiv
  108. SmiMod
  109. SmiNot
  110. SmiAnd
  111. SmiAndConstant
  112. SmiOr
  113. SmiOrConstant
  114. SmiXor
  115. SmiXorConstant
  116. SmiShiftArithmeticRightConstant
  117. SmiShiftLeftConstant
  118. SmiShiftLogicalRightConstant
  119. SmiShiftLeft
  120. SmiShiftLogicalRight
  121. SmiShiftArithmeticRight
  122. SelectNonSmi
  123. SmiToIndex
  124. SmiToNegativeIndex
  125. AddSmiField
  126. JumpIfNotString
  127. JumpIfNotBothSequentialAsciiStrings
  128. JumpIfInstanceTypeIsNotSequentialAscii
  129. JumpIfBothInstanceTypesAreNotSequentialAscii
  130. Move
  131. Move
  132. Move
  133. Cmp
  134. Cmp
  135. Push
  136. LoadHeapObject
  137. PushHeapObject
  138. LoadGlobalCell
  139. Push
  140. Drop
  141. Test
  142. TestBit
  143. Jump
  144. Jump
  145. Jump
  146. CallSize
  147. Call
  148. Call
  149. Call
  150. Pushad
  151. Popad
  152. Dropad
  153. StoreToSafepointRegisterSlot
  154. LoadFromSafepointRegisterSlot
  155. SafepointRegisterSlot
  156. PushTryHandler
  157. PopTryHandler
  158. JumpToHandlerEntry
  159. Throw
  160. ThrowUncatchable
  161. Ret
  162. Ret
  163. FCmp
  164. CmpObjectType
  165. CmpInstanceType
  166. CheckFastElements
  167. CheckFastObjectElements
  168. CheckFastSmiElements
  169. StoreNumberToDoubleElements
  170. CompareMap
  171. CheckMap
  172. ClampUint8
  173. ClampDoubleToUint8
  174. LoadInstanceDescriptors
  175. DispatchMap
  176. AbortIfNotNumber
  177. AbortIfSmi
  178. AbortIfNotSmi
  179. AbortIfNotSmi
  180. AbortIfNotZeroExtended
  181. AbortIfNotString
  182. AbortIfNotRootValue
  183. IsObjectStringType
  184. TryGetFunctionPrototype
  185. SetCounter
  186. IncrementCounter
  187. DecrementCounter
  188. DebugBreak
  189. SetCallKind
  190. InvokeCode
  191. InvokeCode
  192. InvokeFunction
  193. InvokeFunction
  194. InvokePrologue
  195. EnterFrame
  196. LeaveFrame
  197. EnterExitFramePrologue
  198. EnterExitFrameEpilogue
  199. EnterExitFrame
  200. EnterApiExitFrame
  201. LeaveExitFrame
  202. LeaveApiExitFrame
  203. LeaveExitFrameEpilogue
  204. CheckAccessGlobalProxy
  205. GetNumberHash
  206. LoadFromNumberDictionary
  207. LoadAllocationTopHelper
  208. UpdateAllocationTopHelper
  209. AllocateInNewSpace
  210. AllocateInNewSpace
  211. AllocateInNewSpace
  212. UndoAllocationInNewSpace
  213. AllocateHeapNumber
  214. AllocateTwoByteString
  215. AllocateAsciiString
  216. AllocateTwoByteConsString
  217. AllocateAsciiConsString
  218. AllocateTwoByteSlicedString
  219. AllocateAsciiSlicedString
  220. CopyBytes
  221. InitializeFieldsWithFiller
  222. LoadContext
  223. LoadTransitionedArrayMapConditional
  224. LoadInitialArrayMap
  225. LoadGlobalFunction
  226. LoadGlobalFunctionInitialMap
  227. ArgumentStackSlotsForCFunctionCall
  228. PrepareCallCFunction
  229. CallCFunction
  230. CallCFunction
  231. AreAliased
  232. masm_
  233. CheckPageFlag
  234. JumpIfBlack
  235. JumpIfDataObject
  236. GetMarkBits
  237. EnsureNotWhite
  238. CheckEnumCache

// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "v8.h"

#if defined(V8_TARGET_ARCH_X64)

#include "bootstrapper.h"
#include "codegen.h"
#include "assembler-x64.h"
#include "macro-assembler-x64.h"
#include "serialize.h"
#include "debug.h"
#include "heap.h"

namespace v8 {
namespace internal {

MacroAssembler::MacroAssembler(Isolate* arg_isolate, void* buffer, int size)
    : Assembler(arg_isolate, buffer, size),
      generating_stub_(false),
      allow_stub_calls_(true),
      has_frame_(false),
      root_array_available_(true) {
  if (isolate() != NULL) {
    code_object_ = Handle<Object>(isolate()->heap()->undefined_value(),
                                  isolate());
  }
}


static intptr_t RootRegisterDelta(ExternalReference other, Isolate* isolate) {
  Address roots_register_value = kRootRegisterBias +
      reinterpret_cast<Address>(isolate->heap()->roots_array_start());
  intptr_t delta = other.address() - roots_register_value;
  return delta;
}


Operand MacroAssembler::ExternalOperand(ExternalReference target,
                                        Register scratch) {
  if (root_array_available_ && !Serializer::enabled()) {
    intptr_t delta = RootRegisterDelta(target, isolate());
    if (is_int32(delta)) {
      Serializer::TooLateToEnableNow();
      return Operand(kRootRegister, static_cast<int32_t>(delta));
    }
  }
  movq(scratch, target);
  return Operand(scratch, 0);
}


void MacroAssembler::Load(Register destination, ExternalReference source) {
  if (root_array_available_ && !Serializer::enabled()) {
    intptr_t delta = RootRegisterDelta(source, isolate());
    if (is_int32(delta)) {
      Serializer::TooLateToEnableNow();
      movq(destination, Operand(kRootRegister, static_cast<int32_t>(delta)));
      return;
    }
  }
  // Safe code.
  if (destination.is(rax)) {
    load_rax(source);
  } else {
    movq(kScratchRegister, source);
    movq(destination, Operand(kScratchRegister, 0));
  }
}


void MacroAssembler::Store(ExternalReference destination, Register source) {
  if (root_array_available_ && !Serializer::enabled()) {
    intptr_t delta = RootRegisterDelta(destination, isolate());
    if (is_int32(delta)) {
      Serializer::TooLateToEnableNow();
      movq(Operand(kRootRegister, static_cast<int32_t>(delta)), source);
      return;
    }
  }
  // Safe code.
  if (source.is(rax)) {
    store_rax(destination);
  } else {
    movq(kScratchRegister, destination);
    movq(Operand(kScratchRegister, 0), source);
  }
}


void MacroAssembler::LoadAddress(Register destination,
                                 ExternalReference source) {
  if (root_array_available_ && !Serializer::enabled()) {
    intptr_t delta = RootRegisterDelta(source, isolate());
    if (is_int32(delta)) {
      Serializer::TooLateToEnableNow();
      lea(destination, Operand(kRootRegister, static_cast<int32_t>(delta)));
      return;
    }
  }
  // Safe code.
  movq(destination, source);
}


int MacroAssembler::LoadAddressSize(ExternalReference source) {
  if (root_array_available_ && !Serializer::enabled()) {
    // This calculation depends on the internals of LoadAddress.
    // It's correctness is ensured by the asserts in the Call
    // instruction below.
    intptr_t delta = RootRegisterDelta(source, isolate());
    if (is_int32(delta)) {
      Serializer::TooLateToEnableNow();
      // Operand is lea(scratch, Operand(kRootRegister, delta));
      // Opcodes : REX.W 8D ModRM Disp8/Disp32  - 4 or 7.
      int size = 4;
      if (!is_int8(static_cast<int32_t>(delta))) {
        size += 3;  // Need full four-byte displacement in lea.
      }
      return size;
    }
  }
  // Size of movq(destination, src);
  return 10;
}


void MacroAssembler::PushAddress(ExternalReference source) {
  int64_t address = reinterpret_cast<int64_t>(source.address());
  if (is_int32(address) && !Serializer::enabled()) {
    if (emit_debug_code()) {
      movq(kScratchRegister, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
    }
    push(Immediate(static_cast<int32_t>(address)));
    return;
  }
  LoadAddress(kScratchRegister, source);
  push(kScratchRegister);
}


void MacroAssembler::LoadRoot(Register destination, Heap::RootListIndex index) {
  ASSERT(root_array_available_);
  movq(destination, Operand(kRootRegister,
                            (index << kPointerSizeLog2) - kRootRegisterBias));
}


void MacroAssembler::LoadRootIndexed(Register destination,
                                     Register variable_offset,
                                     int fixed_offset) {
  ASSERT(root_array_available_);
  movq(destination,
       Operand(kRootRegister,
               variable_offset, times_pointer_size,
               (fixed_offset << kPointerSizeLog2) - kRootRegisterBias));
}


void MacroAssembler::StoreRoot(Register source, Heap::RootListIndex index) {
  ASSERT(root_array_available_);
  movq(Operand(kRootRegister, (index << kPointerSizeLog2) - kRootRegisterBias),
       source);
}


void MacroAssembler::PushRoot(Heap::RootListIndex index) {
  ASSERT(root_array_available_);
  push(Operand(kRootRegister, (index << kPointerSizeLog2) - kRootRegisterBias));
}


void MacroAssembler::CompareRoot(Register with, Heap::RootListIndex index) {
  ASSERT(root_array_available_);
  cmpq(with, Operand(kRootRegister,
                     (index << kPointerSizeLog2) - kRootRegisterBias));
}


void MacroAssembler::CompareRoot(const Operand& with,
                                 Heap::RootListIndex index) {
  ASSERT(root_array_available_);
  ASSERT(!with.AddressUsesRegister(kScratchRegister));
  LoadRoot(kScratchRegister, index);
  cmpq(with, kScratchRegister);
}


void MacroAssembler::RememberedSetHelper(Register object,  // For debug tests.
                                         Register addr,
                                         Register scratch,
                                         SaveFPRegsMode save_fp,
                                         RememberedSetFinalAction and_then) {
  if (FLAG_debug_code) {
    Label ok;
    JumpIfNotInNewSpace(object, scratch, &ok, Label::kNear);
    int3();
    bind(&ok);
  }
  // Load store buffer top.
  LoadRoot(scratch, Heap::kStoreBufferTopRootIndex);
  // Store pointer to buffer.
  movq(Operand(scratch, 0), addr);
  // Increment buffer top.
  addq(scratch, Immediate(kPointerSize));
  // Write back new top of buffer.
  StoreRoot(scratch, Heap::kStoreBufferTopRootIndex);
  // Call stub on end of buffer.
  Label done;
  // Check for end of buffer.
  testq(scratch, Immediate(StoreBuffer::kStoreBufferOverflowBit));
  if (and_then == kReturnAtEnd) {
    Label buffer_overflowed;
    j(not_equal, &buffer_overflowed, Label::kNear);
    ret(0);
    bind(&buffer_overflowed);
  } else {
    ASSERT(and_then == kFallThroughAtEnd);
    j(equal, &done, Label::kNear);
  }
  StoreBufferOverflowStub store_buffer_overflow =
      StoreBufferOverflowStub(save_fp);
  CallStub(&store_buffer_overflow);
  if (and_then == kReturnAtEnd) {
    ret(0);
  } else {
    ASSERT(and_then == kFallThroughAtEnd);
    bind(&done);
  }
}


void MacroAssembler::InNewSpace(Register object,
                                Register scratch,
                                Condition cc,
                                Label* branch,
                                Label::Distance distance) {
  if (Serializer::enabled()) {
    // Can't do arithmetic on external references if it might get serialized.
    // The mask isn't really an address.  We load it as an external reference in
    // case the size of the new space is different between the snapshot maker
    // and the running system.
    if (scratch.is(object)) {
      movq(kScratchRegister, ExternalReference::new_space_mask(isolate()));
      and_(scratch, kScratchRegister);
    } else {
      movq(scratch, ExternalReference::new_space_mask(isolate()));
      and_(scratch, object);
    }
    movq(kScratchRegister, ExternalReference::new_space_start(isolate()));
    cmpq(scratch, kScratchRegister);
    j(cc, branch, distance);
  } else {
    ASSERT(is_int32(static_cast<int64_t>(HEAP->NewSpaceMask())));
    intptr_t new_space_start =
        reinterpret_cast<intptr_t>(HEAP->NewSpaceStart());
    movq(kScratchRegister, -new_space_start, RelocInfo::NONE);
    if (scratch.is(object)) {
      addq(scratch, kScratchRegister);
    } else {
      lea(scratch, Operand(object, kScratchRegister, times_1, 0));
    }
    and_(scratch, Immediate(static_cast<int32_t>(HEAP->NewSpaceMask())));
    j(cc, branch, distance);
  }
}


void MacroAssembler::RecordWriteField(
    Register object,
    int offset,
    Register value,
    Register dst,
    SaveFPRegsMode save_fp,
    RememberedSetAction remembered_set_action,
    SmiCheck smi_check) {
  // The compiled code assumes that record write doesn't change the
  // context register, so we check that none of the clobbered
  // registers are rsi.
  ASSERT(!value.is(rsi) && !dst.is(rsi));

  // First, check if a write barrier is even needed. The tests below
  // catch stores of Smis.
  Label done;

  // Skip barrier if writing a smi.
  if (smi_check == INLINE_SMI_CHECK) {
    JumpIfSmi(value, &done);
  }

  // Although the object register is tagged, the offset is relative to the start
  // of the object, so so offset must be a multiple of kPointerSize.
  ASSERT(IsAligned(offset, kPointerSize));

  lea(dst, FieldOperand(object, offset));
  if (emit_debug_code()) {
    Label ok;
    testb(dst, Immediate((1 << kPointerSizeLog2) - 1));
    j(zero, &ok, Label::kNear);
    int3();
    bind(&ok);
  }

  RecordWrite(
      object, dst, value, save_fp, remembered_set_action, OMIT_SMI_CHECK);

  bind(&done);

  // Clobber clobbered input registers when running with the debug-code flag
  // turned on to provoke errors.
  if (emit_debug_code()) {
    movq(value, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
    movq(dst, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
  }
}


void MacroAssembler::RecordWriteArray(Register object,
                                      Register value,
                                      Register index,
                                      SaveFPRegsMode save_fp,
                                      RememberedSetAction remembered_set_action,
                                      SmiCheck smi_check) {
  // First, check if a write barrier is even needed. The tests below
  // catch stores of Smis.
  Label done;

  // Skip barrier if writing a smi.
  if (smi_check == INLINE_SMI_CHECK) {
    JumpIfSmi(value, &done);
  }

  // Array access: calculate the destination address. Index is not a smi.
  Register dst = index;
  lea(dst, Operand(object, index, times_pointer_size,
                   FixedArray::kHeaderSize - kHeapObjectTag));

  RecordWrite(
      object, dst, value, save_fp, remembered_set_action, OMIT_SMI_CHECK);

  bind(&done);

  // Clobber clobbered input registers when running with the debug-code flag
  // turned on to provoke errors.
  if (emit_debug_code()) {
    movq(value, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
    movq(index, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
  }
}


void MacroAssembler::RecordWrite(Register object,
                                 Register address,
                                 Register value,
                                 SaveFPRegsMode fp_mode,
                                 RememberedSetAction remembered_set_action,
                                 SmiCheck smi_check) {
  // The compiled code assumes that record write doesn't change the
  // context register, so we check that none of the clobbered
  // registers are rsi.
  ASSERT(!value.is(rsi) && !address.is(rsi));

  ASSERT(!object.is(value));
  ASSERT(!object.is(address));
  ASSERT(!value.is(address));
  if (emit_debug_code()) {
    AbortIfSmi(object);
  }

  if (remembered_set_action == OMIT_REMEMBERED_SET &&
      !FLAG_incremental_marking) {
    return;
  }

  if (FLAG_debug_code) {
    Label ok;
    cmpq(value, Operand(address, 0));
    j(equal, &ok, Label::kNear);
    int3();
    bind(&ok);
  }

  // First, check if a write barrier is even needed. The tests below
  // catch stores of smis and stores into the young generation.
  Label done;

  if (smi_check == INLINE_SMI_CHECK) {
    // Skip barrier if writing a smi.
    JumpIfSmi(value, &done);
  }

  CheckPageFlag(value,
                value,  // Used as scratch.
                MemoryChunk::kPointersToHereAreInterestingMask,
                zero,
                &done,
                Label::kNear);

  CheckPageFlag(object,
                value,  // Used as scratch.
                MemoryChunk::kPointersFromHereAreInterestingMask,
                zero,
                &done,
                Label::kNear);

  RecordWriteStub stub(object, value, address, remembered_set_action, fp_mode);
  CallStub(&stub);

  bind(&done);

  // Clobber clobbered registers when running with the debug-code flag
  // turned on to provoke errors.
  if (emit_debug_code()) {
    movq(address, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
    movq(value, BitCast<int64_t>(kZapValue), RelocInfo::NONE);
  }
}


void MacroAssembler::Assert(Condition cc, const char* msg) {
  if (emit_debug_code()) Check(cc, msg);
}


void MacroAssembler::AssertFastElements(Register elements) {
  if (emit_debug_code()) {
    Label ok;
    CompareRoot(FieldOperand(elements, HeapObject::kMapOffset),
                Heap::kFixedArrayMapRootIndex);
    j(equal, &ok, Label::kNear);
    CompareRoot(FieldOperand(elements, HeapObject::kMapOffset),
                Heap::kFixedDoubleArrayMapRootIndex);
    j(equal, &ok, Label::kNear);
    CompareRoot(FieldOperand(elements, HeapObject::kMapOffset),
                Heap::kFixedCOWArrayMapRootIndex);
    j(equal, &ok, Label::kNear);
    Abort("JSObject with fast elements map has slow elements");
    bind(&ok);
  }
}


void MacroAssembler::Check(Condition cc, const char* msg) {
  Label L;
  j(cc, &L, Label::kNear);
  Abort(msg);
  // Control will not return here.
  bind(&L);
}


void MacroAssembler::CheckStackAlignment() {
  int frame_alignment = OS::ActivationFrameAlignment();
  int frame_alignment_mask = frame_alignment - 1;
  if (frame_alignment > kPointerSize) {
    ASSERT(IsPowerOf2(frame_alignment));
    Label alignment_as_expected;
    testq(rsp, Immediate(frame_alignment_mask));
    j(zero, &alignment_as_expected, Label::kNear);
    // Abort if stack is not aligned.
    int3();
    bind(&alignment_as_expected);
  }
}


void MacroAssembler::NegativeZeroTest(Register result,
                                      Register op,
                                      Label* then_label) {
  Label ok;
  testl(result, result);
  j(not_zero, &ok, Label::kNear);
  testl(op, op);
  j(sign, then_label);
  bind(&ok);
}


void MacroAssembler::Abort(const char* msg) {
  // We want to pass the msg string like a smi to avoid GC
  // problems, however msg is not guaranteed to be aligned
  // properly. Instead, we pass an aligned pointer that is
  // a proper v8 smi, but also pass the alignment difference
  // from the real pointer as a smi.
  intptr_t p1 = reinterpret_cast<intptr_t>(msg);
  intptr_t p0 = (p1 & ~kSmiTagMask) + kSmiTag;
  // Note: p0 might not be a valid Smi _value_, but it has a valid Smi tag.
  ASSERT(reinterpret_cast<Object*>(p0)->IsSmi());
#ifdef DEBUG
  if (msg != NULL) {
    RecordComment("Abort message: ");
    RecordComment(msg);
  }
#endif
  push(rax);
  movq(kScratchRegister, p0, RelocInfo::NONE);
  push(kScratchRegister);
  movq(kScratchRegister,
       reinterpret_cast<intptr_t>(Smi::FromInt(static_cast<int>(p1 - p0))),
       RelocInfo::NONE);
  push(kScratchRegister);

  if (!has_frame_) {
    // We don't actually want to generate a pile of code for this, so just
    // claim there is a stack frame, without generating one.
    FrameScope scope(this, StackFrame::NONE);
    CallRuntime(Runtime::kAbort, 2);
  } else {
    CallRuntime(Runtime::kAbort, 2);
  }
  // Control will not return here.
  int3();
}


void MacroAssembler::CallStub(CodeStub* stub, unsigned ast_id) {
  ASSERT(AllowThisStubCall(stub));  // Calls are not allowed in some stubs
  Call(stub->GetCode(), RelocInfo::CODE_TARGET, ast_id);
}


void MacroAssembler::TailCallStub(CodeStub* stub) {
  ASSERT(allow_stub_calls_ || stub->CompilingCallsToThisStubIsGCSafe());
  Jump(stub->GetCode(), RelocInfo::CODE_TARGET);
}


void MacroAssembler::StubReturn(int argc) {
  ASSERT(argc >= 1 && generating_stub());
  ret((argc - 1) * kPointerSize);
}


bool MacroAssembler::AllowThisStubCall(CodeStub* stub) {
  if (!has_frame_ && stub->SometimesSetsUpAFrame()) return false;
  return allow_stub_calls_ || stub->CompilingCallsToThisStubIsGCSafe();
}


void MacroAssembler::IllegalOperation(int num_arguments) {
  if (num_arguments > 0) {
    addq(rsp, Immediate(num_arguments * kPointerSize));
  }
  LoadRoot(rax, Heap::kUndefinedValueRootIndex);
}


void MacroAssembler::IndexFromHash(Register hash, Register index) {
  // The assert checks that the constants for the maximum number of digits
  // for an array index cached in the hash field and the number of bits
  // reserved for it does not conflict.
  ASSERT(TenToThe(String::kMaxCachedArrayIndexLength) <
         (1 << String::kArrayIndexValueBits));
  // We want the smi-tagged index in key. Even if we subsequently go to
  // the slow case, converting the key to a smi is always valid.
  // key: string key
  // hash: key's hash field, including its array index value.
  and_(hash, Immediate(String::kArrayIndexValueMask));
  shr(hash, Immediate(String::kHashShift));
  // Here we actually clobber the key which will be used if calling into
  // runtime later. However as the new key is the numeric value of a string key
  // there is no difference in using either key.
  Integer32ToSmi(index, hash);
}


void MacroAssembler::CallRuntime(Runtime::FunctionId id, int num_arguments) {
  CallRuntime(Runtime::FunctionForId(id), num_arguments);
}


void MacroAssembler::CallRuntimeSaveDoubles(Runtime::FunctionId id) {
  const Runtime::Function* function = Runtime::FunctionForId(id);
  Set(rax, function->nargs);
  LoadAddress(rbx, ExternalReference(function, isolate()));
  CEntryStub ces(1, kSaveFPRegs);
  CallStub(&ces);
}


void MacroAssembler::CallRuntime(const Runtime::Function* f,
                                 int num_arguments) {
  // If the expected number of arguments of the runtime function is
  // constant, we check that the actual number of arguments match the
  // expectation.
  if (f->nargs >= 0 && f->nargs != num_arguments) {
    IllegalOperation(num_arguments);
    return;
  }

  // TODO(1236192): Most runtime routines don't need the number of
  // arguments passed in because it is constant. At some point we
  // should remove this need and make the runtime routine entry code
  // smarter.
  Set(rax, num_arguments);
  LoadAddress(rbx, ExternalReference(f, isolate()));
  CEntryStub ces(f->result_size);
  CallStub(&ces);
}


void MacroAssembler::CallExternalReference(const ExternalReference& ext,
                                           int num_arguments) {
  Set(rax, num_arguments);
  LoadAddress(rbx, ext);

  CEntryStub stub(1);
  CallStub(&stub);
}


void MacroAssembler::TailCallExternalReference(const ExternalReference& ext,
                                               int num_arguments,
                                               int result_size) {
  // ----------- S t a t e -------------
  //  -- rsp[0] : return address
  //  -- rsp[8] : argument num_arguments - 1
  //  ...
  //  -- rsp[8 * num_arguments] : argument 0 (receiver)
  // -----------------------------------

  // TODO(1236192): Most runtime routines don't need the number of
  // arguments passed in because it is constant. At some point we
  // should remove this need and make the runtime routine entry code
  // smarter.
  Set(rax, num_arguments);
  JumpToExternalReference(ext, result_size);
}


void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid,
                                     int num_arguments,
                                     int result_size) {
  TailCallExternalReference(ExternalReference(fid, isolate()),
                            num_arguments,
                            result_size);
}


static int Offset(ExternalReference ref0, ExternalReference ref1) {
  int64_t offset = (ref0.address() - ref1.address());
  // Check that fits into int.
  ASSERT(static_cast<int>(offset) == offset);
  return static_cast<int>(offset);
}


void MacroAssembler::PrepareCallApiFunction(int arg_stack_space) {
#if defined(_WIN64) && !defined(__MINGW64__)
  // We need to prepare a slot for result handle on stack and put
  // a pointer to it into 1st arg register.
  EnterApiExitFrame(arg_stack_space + 1);

  // rcx must be used to pass the pointer to the return value slot.
  lea(rcx, StackSpaceOperand(arg_stack_space));
#else
  EnterApiExitFrame(arg_stack_space);
#endif
}


void MacroAssembler::CallApiFunctionAndReturn(Address function_address,
                                              int stack_space) {
  Label empty_result;
  Label prologue;
  Label promote_scheduled_exception;
  Label delete_allocated_handles;
  Label leave_exit_frame;
  Label write_back;

  Factory* factory = isolate()->factory();
  ExternalReference next_address =
      ExternalReference::handle_scope_next_address();
  const int kNextOffset = 0;
  const int kLimitOffset = Offset(
      ExternalReference::handle_scope_limit_address(),
      next_address);
  const int kLevelOffset = Offset(
      ExternalReference::handle_scope_level_address(),
      next_address);
  ExternalReference scheduled_exception_address =
      ExternalReference::scheduled_exception_address(isolate());

  // Allocate HandleScope in callee-save registers.
  Register prev_next_address_reg = r14;
  Register prev_limit_reg = rbx;
  Register base_reg = r15;
  movq(base_reg, next_address);
  movq(prev_next_address_reg, Operand(base_reg, kNextOffset));
  movq(prev_limit_reg, Operand(base_reg, kLimitOffset));
  addl(Operand(base_reg, kLevelOffset), Immediate(1));
  // Call the api function!
  movq(rax, reinterpret_cast<int64_t>(function_address),
       RelocInfo::RUNTIME_ENTRY);
  call(rax);

#if defined(_WIN64) && !defined(__MINGW64__)
  // rax keeps a pointer to v8::Handle, unpack it.
  movq(rax, Operand(rax, 0));
#endif
  // Check if the result handle holds 0.
  testq(rax, rax);
  j(zero, &empty_result);
  // It was non-zero.  Dereference to get the result value.
  movq(rax, Operand(rax, 0));
  bind(&prologue);

  // No more valid handles (the result handle was the last one). Restore
  // previous handle scope.
  subl(Operand(base_reg, kLevelOffset), Immediate(1));
  movq(Operand(base_reg, kNextOffset), prev_next_address_reg);
  cmpq(prev_limit_reg, Operand(base_reg, kLimitOffset));
  j(not_equal, &delete_allocated_handles);
  bind(&leave_exit_frame);

  // Check if the function scheduled an exception.
  movq(rsi, scheduled_exception_address);
  Cmp(Operand(rsi, 0), factory->the_hole_value());
  j(not_equal, &promote_scheduled_exception);

  LeaveApiExitFrame();
  ret(stack_space * kPointerSize);

  bind(&promote_scheduled_exception);
  TailCallRuntime(Runtime::kPromoteScheduledException, 0, 1);

  bind(&empty_result);
  // It was zero; the result is undefined.
  Move(rax, factory->undefined_value());
  jmp(&prologue);

  // HandleScope limit has changed. Delete allocated extensions.
  bind(&delete_allocated_handles);
  movq(Operand(base_reg, kLimitOffset), prev_limit_reg);
  movq(prev_limit_reg, rax);
#ifdef _WIN64
  LoadAddress(rcx, ExternalReference::isolate_address());
#else
  LoadAddress(rdi, ExternalReference::isolate_address());
#endif
  LoadAddress(rax,
              ExternalReference::delete_handle_scope_extensions(isolate()));
  call(rax);
  movq(rax, prev_limit_reg);
  jmp(&leave_exit_frame);
}


void MacroAssembler::JumpToExternalReference(const ExternalReference& ext,
                                             int result_size) {
  // Set the entry point and jump to the C entry runtime stub.
  LoadAddress(rbx, ext);
  CEntryStub ces(result_size);
  jmp(ces.GetCode(), RelocInfo::CODE_TARGET);
}


void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
                                   InvokeFlag flag,
                                   const CallWrapper& call_wrapper) {
  // You can't call a builtin without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  // Rely on the assertion to check that the number of provided
  // arguments match the expected number of arguments. Fake a
  // parameter count to avoid emitting code to do the check.
  ParameterCount expected(0);
  GetBuiltinEntry(rdx, id);
  InvokeCode(rdx, expected, expected, flag, call_wrapper, CALL_AS_METHOD);
}


void MacroAssembler::GetBuiltinFunction(Register target,
                                        Builtins::JavaScript id) {
  // Load the builtins object into target register.
  movq(target, Operand(rsi, Context::SlotOffset(Context::GLOBAL_INDEX)));
  movq(target, FieldOperand(target, GlobalObject::kBuiltinsOffset));
  movq(target, FieldOperand(target,
                            JSBuiltinsObject::OffsetOfFunctionWithId(id)));
}


void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
  ASSERT(!target.is(rdi));
  // Load the JavaScript builtin function from the builtins object.
  GetBuiltinFunction(rdi, id);
  movq(target, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
}


#define REG(Name) { kRegister_ ## Name ## _Code }

static const Register saved_regs[] = {
  REG(rax), REG(rcx), REG(rdx), REG(rbx), REG(rbp), REG(rsi), REG(rdi), REG(r8),
  REG(r9), REG(r10), REG(r11)
};

#undef REG

static const int kNumberOfSavedRegs = sizeof(saved_regs) / sizeof(Register);


void MacroAssembler::PushCallerSaved(SaveFPRegsMode fp_mode,
                                     Register exclusion1,
                                     Register exclusion2,
                                     Register exclusion3) {
  // We don't allow a GC during a store buffer overflow so there is no need to
  // store the registers in any particular way, but we do have to store and
  // restore them.
  for (int i = 0; i < kNumberOfSavedRegs; i++) {
    Register reg = saved_regs[i];
    if (!reg.is(exclusion1) && !reg.is(exclusion2) && !reg.is(exclusion3)) {
      push(reg);
    }
  }
  // R12 to r15 are callee save on all platforms.
  if (fp_mode == kSaveFPRegs) {
    CpuFeatures::Scope scope(SSE2);
    subq(rsp, Immediate(kDoubleSize * XMMRegister::kNumRegisters));
    for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
      XMMRegister reg = XMMRegister::from_code(i);
      movsd(Operand(rsp, i * kDoubleSize), reg);
    }
  }
}


void MacroAssembler::PopCallerSaved(SaveFPRegsMode fp_mode,
                                    Register exclusion1,
                                    Register exclusion2,
                                    Register exclusion3) {
  if (fp_mode == kSaveFPRegs) {
    CpuFeatures::Scope scope(SSE2);
    for (int i = 0; i < XMMRegister::kNumRegisters; i++) {
      XMMRegister reg = XMMRegister::from_code(i);
      movsd(reg, Operand(rsp, i * kDoubleSize));
    }
    addq(rsp, Immediate(kDoubleSize * XMMRegister::kNumRegisters));
  }
  for (int i = kNumberOfSavedRegs - 1; i >= 0; i--) {
    Register reg = saved_regs[i];
    if (!reg.is(exclusion1) && !reg.is(exclusion2) && !reg.is(exclusion3)) {
      pop(reg);
    }
  }
}


void MacroAssembler::Set(Register dst, int64_t x) {
  if (x == 0) {
    xorl(dst, dst);
  } else if (is_uint32(x)) {
    movl(dst, Immediate(static_cast<uint32_t>(x)));
  } else if (is_int32(x)) {
    movq(dst, Immediate(static_cast<int32_t>(x)));
  } else {
    movq(dst, x, RelocInfo::NONE);
  }
}

void MacroAssembler::Set(const Operand& dst, int64_t x) {
  if (is_int32(x)) {
    movq(dst, Immediate(static_cast<int32_t>(x)));
  } else {
    Set(kScratchRegister, x);
    movq(dst, kScratchRegister);
  }
}


bool MacroAssembler::IsUnsafeInt(const int x) {
  static const int kMaxBits = 17;
  return !is_intn(x, kMaxBits);
}


void MacroAssembler::SafeMove(Register dst, Smi* src) {
  ASSERT(!dst.is(kScratchRegister));
  ASSERT(kSmiValueSize == 32);  // JIT cookie can be converted to Smi.
  if (IsUnsafeInt(src->value()) && jit_cookie() != 0) {
    Move(dst, Smi::FromInt(src->value() ^ jit_cookie()));
    Move(kScratchRegister, Smi::FromInt(jit_cookie()));
    xor_(dst, kScratchRegister);
  } else {
    Move(dst, src);
  }
}


void MacroAssembler::SafePush(Smi* src) {
  ASSERT(kSmiValueSize == 32);  // JIT cookie can be converted to Smi.
  if (IsUnsafeInt(src->value()) && jit_cookie() != 0) {
    Push(Smi::FromInt(src->value() ^ jit_cookie()));
    Move(kScratchRegister, Smi::FromInt(jit_cookie()));
    xor_(Operand(rsp, 0), kScratchRegister);
  } else {
    Push(src);
  }
}


// ----------------------------------------------------------------------------
// Smi tagging, untagging and tag detection.

Register MacroAssembler::GetSmiConstant(Smi* source) {
  int value = source->value();
  if (value == 0) {
    xorl(kScratchRegister, kScratchRegister);
    return kScratchRegister;
  }
  if (value == 1) {
    return kSmiConstantRegister;
  }
  LoadSmiConstant(kScratchRegister, source);
  return kScratchRegister;
}

void MacroAssembler::LoadSmiConstant(Register dst, Smi* source) {
  if (emit_debug_code()) {
    movq(dst,
         reinterpret_cast<uint64_t>(Smi::FromInt(kSmiConstantRegisterValue)),
         RelocInfo::NONE);
    cmpq(dst, kSmiConstantRegister);
    if (allow_stub_calls()) {
      Assert(equal, "Uninitialized kSmiConstantRegister");
    } else {
      Label ok;
      j(equal, &ok, Label::kNear);
      int3();
      bind(&ok);
    }
  }
  int value = source->value();
  if (value == 0) {
    xorl(dst, dst);
    return;
  }
  bool negative = value < 0;
  unsigned int uvalue = negative ? -value : value;

  switch (uvalue) {
    case 9:
      lea(dst, Operand(kSmiConstantRegister, kSmiConstantRegister, times_8, 0));
      break;
    case 8:
      xorl(dst, dst);
      lea(dst, Operand(dst, kSmiConstantRegister, times_8, 0));
      break;
    case 4:
      xorl(dst, dst);
      lea(dst, Operand(dst, kSmiConstantRegister, times_4, 0));
      break;
    case 5:
      lea(dst, Operand(kSmiConstantRegister, kSmiConstantRegister, times_4, 0));
      break;
    case 3:
      lea(dst, Operand(kSmiConstantRegister, kSmiConstantRegister, times_2, 0));
      break;
    case 2:
      lea(dst, Operand(kSmiConstantRegister, kSmiConstantRegister, times_1, 0));
      break;
    case 1:
      movq(dst, kSmiConstantRegister);
      break;
    case 0:
      UNREACHABLE();
      return;
    default:
      movq(dst, reinterpret_cast<uint64_t>(source), RelocInfo::NONE);
      return;
  }
  if (negative) {
    neg(dst);
  }
}


void MacroAssembler::Integer32ToSmi(Register dst, Register src) {
  STATIC_ASSERT(kSmiTag == 0);
  if (!dst.is(src)) {
    movl(dst, src);
  }
  shl(dst, Immediate(kSmiShift));
}


void MacroAssembler::Integer32ToSmiField(const Operand& dst, Register src) {
  if (emit_debug_code()) {
    testb(dst, Immediate(0x01));
    Label ok;
    j(zero, &ok, Label::kNear);
    if (allow_stub_calls()) {
      Abort("Integer32ToSmiField writing to non-smi location");
    } else {
      int3();
    }
    bind(&ok);
  }
  ASSERT(kSmiShift % kBitsPerByte == 0);
  movl(Operand(dst, kSmiShift / kBitsPerByte), src);
}


void MacroAssembler::Integer64PlusConstantToSmi(Register dst,
                                                Register src,
                                                int constant) {
  if (dst.is(src)) {
    addl(dst, Immediate(constant));
  } else {
    leal(dst, Operand(src, constant));
  }
  shl(dst, Immediate(kSmiShift));
}


void MacroAssembler::SmiToInteger32(Register dst, Register src) {
  STATIC_ASSERT(kSmiTag == 0);
  if (!dst.is(src)) {
    movq(dst, src);
  }
  shr(dst, Immediate(kSmiShift));
}


void MacroAssembler::SmiToInteger32(Register dst, const Operand& src) {
  movl(dst, Operand(src, kSmiShift / kBitsPerByte));
}


void MacroAssembler::SmiToInteger64(Register dst, Register src) {
  STATIC_ASSERT(kSmiTag == 0);
  if (!dst.is(src)) {
    movq(dst, src);
  }
  sar(dst, Immediate(kSmiShift));
}


void MacroAssembler::SmiToInteger64(Register dst, const Operand& src) {
  movsxlq(dst, Operand(src, kSmiShift / kBitsPerByte));
}


void MacroAssembler::SmiTest(Register src) {
  testq(src, src);
}


void MacroAssembler::SmiCompare(Register smi1, Register smi2) {
  if (emit_debug_code()) {
    AbortIfNotSmi(smi1);
    AbortIfNotSmi(smi2);
  }
  cmpq(smi1, smi2);
}


void MacroAssembler::SmiCompare(Register dst, Smi* src) {
  if (emit_debug_code()) {
    AbortIfNotSmi(dst);
  }
  Cmp(dst, src);
}


void MacroAssembler::Cmp(Register dst, Smi* src) {
  ASSERT(!dst.is(kScratchRegister));
  if (src->value() == 0) {
    testq(dst, dst);
  } else {
    Register constant_reg = GetSmiConstant(src);
    cmpq(dst, constant_reg);
  }
}


void MacroAssembler::SmiCompare(Register dst, const Operand& src) {
  if (emit_debug_code()) {
    AbortIfNotSmi(dst);
    AbortIfNotSmi(src);
  }
  cmpq(dst, src);
}


void MacroAssembler::SmiCompare(const Operand& dst, Register src) {
  if (emit_debug_code()) {
    AbortIfNotSmi(dst);
    AbortIfNotSmi(src);
  }
  cmpq(dst, src);
}


void MacroAssembler::SmiCompare(const Operand& dst, Smi* src) {
  if (emit_debug_code()) {
    AbortIfNotSmi(dst);
  }
  cmpl(Operand(dst, kSmiShift / kBitsPerByte), Immediate(src->value()));
}


void MacroAssembler::Cmp(const Operand& dst, Smi* src) {
  // The Operand cannot use the smi register.
  Register smi_reg = GetSmiConstant(src);
  ASSERT(!dst.AddressUsesRegister(smi_reg));
  cmpq(dst, smi_reg);
}


void MacroAssembler::SmiCompareInteger32(const Operand& dst, Register src) {
  cmpl(Operand(dst, kSmiShift / kBitsPerByte), src);
}


void MacroAssembler::PositiveSmiTimesPowerOfTwoToInteger64(Register dst,
                                                           Register src,
                                                           int power) {
  ASSERT(power >= 0);
  ASSERT(power < 64);
  if (power == 0) {
    SmiToInteger64(dst, src);
    return;
  }
  if (!dst.is(src)) {
    movq(dst, src);
  }
  if (power < kSmiShift) {
    sar(dst, Immediate(kSmiShift - power));
  } else if (power > kSmiShift) {
    shl(dst, Immediate(power - kSmiShift));
  }
}


void MacroAssembler::PositiveSmiDivPowerOfTwoToInteger32(Register dst,
                                                         Register src,
                                                         int power) {
  ASSERT((0 <= power) && (power < 32));
  if (dst.is(src)) {
    shr(dst, Immediate(power + kSmiShift));
  } else {
    UNIMPLEMENTED();  // Not used.
  }
}


void MacroAssembler::SmiOrIfSmis(Register dst, Register src1, Register src2,
                                 Label* on_not_smis,
                                 Label::Distance near_jump) {
  if (dst.is(src1) || dst.is(src2)) {
    ASSERT(!src1.is(kScratchRegister));
    ASSERT(!src2.is(kScratchRegister));
    movq(kScratchRegister, src1);
    or_(kScratchRegister, src2);
    JumpIfNotSmi(kScratchRegister, on_not_smis, near_jump);
    movq(dst, kScratchRegister);
  } else {
    movq(dst, src1);
    or_(dst, src2);
    JumpIfNotSmi(dst, on_not_smis, near_jump);
  }
}


Condition MacroAssembler::CheckSmi(Register src) {
  STATIC_ASSERT(kSmiTag == 0);
  testb(src, Immediate(kSmiTagMask));
  return zero;
}


Condition MacroAssembler::CheckSmi(const Operand& src) {
  STATIC_ASSERT(kSmiTag == 0);
  testb(src, Immediate(kSmiTagMask));
  return zero;
}


Condition MacroAssembler::CheckNonNegativeSmi(Register src) {
  STATIC_ASSERT(kSmiTag == 0);
  // Test that both bits of the mask 0x8000000000000001 are zero.
  movq(kScratchRegister, src);
  rol(kScratchRegister, Immediate(1));
  testb(kScratchRegister, Immediate(3));
  return zero;
}


Condition MacroAssembler::CheckBothSmi(Register first, Register second) {
  if (first.is(second)) {
    return CheckSmi(first);
  }
  STATIC_ASSERT(kSmiTag == 0 && kHeapObjectTag == 1 && kHeapObjectTagMask == 3);
  leal(kScratchRegister, Operand(first, second, times_1, 0));
  testb(kScratchRegister, Immediate(0x03));
  return zero;
}


Condition MacroAssembler::CheckBothNonNegativeSmi(Register first,
                                                  Register second) {
  if (first.is(second)) {
    return CheckNonNegativeSmi(first);
  }
  movq(kScratchRegister, first);
  or_(kScratchRegister, second);
  rol(kScratchRegister, Immediate(1));
  testl(kScratchRegister, Immediate(3));
  return zero;
}


Condition MacroAssembler::CheckEitherSmi(Register first,
                                         Register second,
                                         Register scratch) {
  if (first.is(second)) {
    return CheckSmi(first);
  }
  if (scratch.is(second)) {
    andl(scratch, first);
  } else {
    if (!scratch.is(first)) {
      movl(scratch, first);
    }
    andl(scratch, second);
  }
  testb(scratch, Immediate(kSmiTagMask));
  return zero;
}


Condition MacroAssembler::CheckIsMinSmi(Register src) {
  ASSERT(!src.is(kScratchRegister));
  // If we overflow by subtracting one, it's the minimal smi value.
  cmpq(src, kSmiConstantRegister);
  return overflow;
}


Condition MacroAssembler::CheckInteger32ValidSmiValue(Register src) {
  // A 32-bit integer value can always be converted to a smi.
  return always;
}


Condition MacroAssembler::CheckUInteger32ValidSmiValue(Register src) {
  // An unsigned 32-bit integer value is valid as long as the high bit
  // is not set.
  testl(src, src);
  return positive;
}


void MacroAssembler::CheckSmiToIndicator(Register dst, Register src) {
  if (dst.is(src)) {
    andl(dst, Immediate(kSmiTagMask));
  } else {
    movl(dst, Immediate(kSmiTagMask));
    andl(dst, src);
  }
}


void MacroAssembler::CheckSmiToIndicator(Register dst, const Operand& src) {
  if (!(src.AddressUsesRegister(dst))) {
    movl(dst, Immediate(kSmiTagMask));
    andl(dst, src);
  } else {
    movl(dst, src);
    andl(dst, Immediate(kSmiTagMask));
  }
}


void MacroAssembler::JumpIfNotValidSmiValue(Register src,
                                            Label* on_invalid,
                                            Label::Distance near_jump) {
  Condition is_valid = CheckInteger32ValidSmiValue(src);
  j(NegateCondition(is_valid), on_invalid, near_jump);
}


void MacroAssembler::JumpIfUIntNotValidSmiValue(Register src,
                                                Label* on_invalid,
                                                Label::Distance near_jump) {
  Condition is_valid = CheckUInteger32ValidSmiValue(src);
  j(NegateCondition(is_valid), on_invalid, near_jump);
}


void MacroAssembler::JumpIfSmi(Register src,
                               Label* on_smi,
                               Label::Distance near_jump) {
  Condition smi = CheckSmi(src);
  j(smi, on_smi, near_jump);
}


void MacroAssembler::JumpIfNotSmi(Register src,
                                  Label* on_not_smi,
                                  Label::Distance near_jump) {
  Condition smi = CheckSmi(src);
  j(NegateCondition(smi), on_not_smi, near_jump);
}


void MacroAssembler::JumpUnlessNonNegativeSmi(
    Register src, Label* on_not_smi_or_negative,
    Label::Distance near_jump) {
  Condition non_negative_smi = CheckNonNegativeSmi(src);
  j(NegateCondition(non_negative_smi), on_not_smi_or_negative, near_jump);
}


void MacroAssembler::JumpIfSmiEqualsConstant(Register src,
                                             Smi* constant,
                                             Label* on_equals,
                                             Label::Distance near_jump) {
  SmiCompare(src, constant);
  j(equal, on_equals, near_jump);
}


void MacroAssembler::JumpIfNotBothSmi(Register src1,
                                      Register src2,
                                      Label* on_not_both_smi,
                                      Label::Distance near_jump) {
  Condition both_smi = CheckBothSmi(src1, src2);
  j(NegateCondition(both_smi), on_not_both_smi, near_jump);
}


void MacroAssembler::JumpUnlessBothNonNegativeSmi(Register src1,
                                                  Register src2,
                                                  Label* on_not_both_smi,
                                                  Label::Distance near_jump) {
  Condition both_smi = CheckBothNonNegativeSmi(src1, src2);
  j(NegateCondition(both_smi), on_not_both_smi, near_jump);
}


void MacroAssembler::SmiTryAddConstant(Register dst,
                                       Register src,
                                       Smi* constant,
                                       Label* on_not_smi_result,
                                       Label::Distance near_jump) {
  // Does not assume that src is a smi.
  ASSERT_EQ(static_cast<int>(1), static_cast<int>(kSmiTagMask));
  STATIC_ASSERT(kSmiTag == 0);
  ASSERT(!dst.is(kScratchRegister));
  ASSERT(!src.is(kScratchRegister));

  JumpIfNotSmi(src, on_not_smi_result, near_jump);
  Register tmp = (dst.is(src) ? kScratchRegister : dst);
  LoadSmiConstant(tmp, constant);
  addq(tmp, src);
  j(overflow, on_not_smi_result, near_jump);
  if (dst.is(src)) {
    movq(dst, tmp);
  }
}


void MacroAssembler::SmiAddConstant(Register dst, Register src, Smi* constant) {
  if (constant->value() == 0) {
    if (!dst.is(src)) {
      movq(dst, src);
    }
    return;
  } else if (dst.is(src)) {
    ASSERT(!dst.is(kScratchRegister));
    switch (constant->value()) {
      case 1:
        addq(dst, kSmiConstantRegister);
        return;
      case 2:
        lea(dst, Operand(src, kSmiConstantRegister, times_2, 0));
        return;
      case 4:
        lea(dst, Operand(src, kSmiConstantRegister, times_4, 0));
        return;
      case 8:
        lea(dst, Operand(src, kSmiConstantRegister, times_8, 0));
        return;
      default:
        Register constant_reg = GetSmiConstant(constant);
        addq(dst, constant_reg);
        return;
    }
  } else {
    switch (constant->value()) {
      case 1:
        lea(dst, Operand(src, kSmiConstantRegister, times_1, 0));
        return;
      case 2:
        lea(dst, Operand(src, kSmiConstantRegister, times_2, 0));
        return;
      case 4:
        lea(dst, Operand(src, kSmiConstantRegister, times_4, 0));
        return;
      case 8:
        lea(dst, Operand(src, kSmiConstantRegister, times_8, 0));
        return;
      default:
        LoadSmiConstant(dst, constant);
        addq(dst, src);
        return;
    }
  }
}


void MacroAssembler::SmiAddConstant(const Operand& dst, Smi* constant) {
  if (constant->value() != 0) {
    addl(Operand(dst, kSmiShift / kBitsPerByte), Immediate(constant->value()));
  }
}


void MacroAssembler::SmiAddConstant(Register dst,
                                    Register src,
                                    Smi* constant,
                                    Label* on_not_smi_result,
                                    Label::Distance near_jump) {
  if (constant->value() == 0) {
    if (!dst.is(src)) {
      movq(dst, src);
    }
  } else if (dst.is(src)) {
    ASSERT(!dst.is(kScratchRegister));

    LoadSmiConstant(kScratchRegister, constant);
    addq(kScratchRegister, src);
    j(overflow, on_not_smi_result, near_jump);
    movq(dst, kScratchRegister);
  } else {
    LoadSmiConstant(dst, constant);
    addq(dst, src);
    j(overflow, on_not_smi_result, near_jump);
  }
}


void MacroAssembler::SmiSubConstant(Register dst, Register src, Smi* constant) {
  if (constant->value() == 0) {
    if (!dst.is(src)) {
      movq(dst, src);
    }
  } else if (dst.is(src)) {
    ASSERT(!dst.is(kScratchRegister));
    Register constant_reg = GetSmiConstant(constant);
    subq(dst, constant_reg);
  } else {
    if (constant->value() == Smi::kMinValue) {
      LoadSmiConstant(dst, constant);
      // Adding and subtracting the min-value gives the same result, it only
      // differs on the overflow bit, which we don't check here.
      addq(dst, src);
    } else {
      // Subtract by adding the negation.
      LoadSmiConstant(dst, Smi::FromInt(-constant->value()));
      addq(dst, src);
    }
  }
}


void MacroAssembler::SmiSubConstant(Register dst,
                                    Register src,
                                    Smi* constant,
                                    Label* on_not_smi_result,
                                    Label::Distance near_jump) {
  if (constant->value() == 0) {
    if (!dst.is(src)) {
      movq(dst, src);
    }
  } else if (dst.is(src)) {
    ASSERT(!dst.is(kScratchRegister));
    if (constant->value() == Smi::kMinValue) {
      // Subtracting min-value from any non-negative value will overflow.
      // We test the non-negativeness before doing the subtraction.
      testq(src, src);
      j(not_sign, on_not_smi_result, near_jump);
      LoadSmiConstant(kScratchRegister, constant);
      subq(dst, kScratchRegister);
    } else {
      // Subtract by adding the negation.
      LoadSmiConstant(kScratchRegister, Smi::FromInt(-constant->value()));
      addq(kScratchRegister, dst);
      j(overflow, on_not_smi_result, near_jump);
      movq(dst, kScratchRegister);
    }
  } else {
    if (constant->value() == Smi::kMinValue) {
      // Subtracting min-value from any non-negative value will overflow.
      // We test the non-negativeness before doing the subtraction.
      testq(src, src);
      j(not_sign, on_not_smi_result, near_jump);
      LoadSmiConstant(dst, constant);
      // Adding and subtracting the min-value gives the same result, it only
      // differs on the overflow bit, which we don't check here.
      addq(dst, src);
    } else {
      // Subtract by adding the negation.
      LoadSmiConstant(dst, Smi::FromInt(-(constant->value())));
      addq(dst, src);
      j(overflow, on_not_smi_result, near_jump);
    }
  }
}


void MacroAssembler::SmiNeg(Register dst,
                            Register src,
                            Label* on_smi_result,
                            Label::Distance near_jump) {
  if (dst.is(src)) {
    ASSERT(!dst.is(kScratchRegister));
    movq(kScratchRegister, src);
    neg(dst);  // Low 32 bits are retained as zero by negation.
    // Test if result is zero or Smi::kMinValue.
    cmpq(dst, kScratchRegister);
    j(not_equal, on_smi_result, near_jump);
    movq(src, kScratchRegister);
  } else {
    movq(dst, src);
    neg(dst);
    cmpq(dst, src);
    // If the result is zero or Smi::kMinValue, negation failed to create a smi.
    j(not_equal, on_smi_result, near_jump);
  }
}


void MacroAssembler::SmiAdd(Register dst,
                            Register src1,
                            Register src2,
                            Label* on_not_smi_result,
                            Label::Distance near_jump) {
  ASSERT_NOT_NULL(on_not_smi_result);
  ASSERT(!dst.is(src2));
  if (dst.is(src1)) {
    movq(kScratchRegister, src1);
    addq(kScratchRegister, src2);
    j(overflow, on_not_smi_result, near_jump);
    movq(dst, kScratchRegister);
  } else {
    movq(dst, src1);
    addq(dst, src2);
    j(overflow, on_not_smi_result, near_jump);
  }
}


void MacroAssembler::SmiAdd(Register dst,
                            Register src1,
                            const Operand& src2,
                            Label* on_not_smi_result,
                            Label::Distance near_jump) {
  ASSERT_NOT_NULL(on_not_smi_result);
  if (dst.is(src1)) {
    movq(kScratchRegister, src1);
    addq(kScratchRegister, src2);
    j(overflow, on_not_smi_result, near_jump);
    movq(dst, kScratchRegister);
  } else {
    ASSERT(!src2.AddressUsesRegister(dst));
    movq(dst, src1);
    addq(dst, src2);
    j(overflow, on_not_smi_result, near_jump);
  }
}


void MacroAssembler::SmiAdd(Register dst,
                            Register src1,
                            Register src2) {
  // No overflow checking. Use only when it's known that
  // overflowing is impossible.
  if (!dst.is(src1)) {
    if (emit_debug_code()) {
      movq(kScratchRegister, src1);
      addq(kScratchRegister, src2);
      Check(no_overflow, "Smi addition overflow");
    }
    lea(dst, Operand(src1, src2, times_1, 0));
  } else {
    addq(dst, src2);
    Assert(no_overflow, "Smi addition overflow");
  }
}


void MacroAssembler::SmiSub(Register dst,
                            Register src1,
                            Register src2,
                            Label* on_not_smi_result,
                            Label::Distance near_jump) {
  ASSERT_NOT_NULL(on_not_smi_result);
  ASSERT(!dst.is(src2));
  if (dst.is(src1)) {
    cmpq(dst, src2);
    j(overflow, on_not_smi_result, near_jump);
    subq(dst, src2);
  } else {
    movq(dst, src1);
    subq(dst, src2);
    j(overflow, on_not_smi_result, near_jump);
  }
}


void MacroAssembler::SmiSub(Register dst, Register src1, Register src2) {
  // No overflow checking. Use only when it's known that
  // overflowing is impossible (e.g., subtracting two positive smis).
  ASSERT(!dst.is(src2));
  if (!dst.is(src1)) {
    movq(dst, src1);
  }
  subq(dst, src2);
  Assert(no_overflow, "Smi subtraction overflow");
}


void MacroAssembler::SmiSub(Register dst,
                            Register src1,
                            const Operand& src2,
                            Label* on_not_smi_result,
                            Label::Distance near_jump) {
  ASSERT_NOT_NULL(on_not_smi_result);
  if (dst.is(src1)) {
    movq(kScratchRegister, src2);
    cmpq(src1, kScratchRegister);
    j(overflow, on_not_smi_result, near_jump);
    subq(src1, kScratchRegister);
  } else {
    movq(dst, src1);
    subq(dst, src2);
    j(overflow, on_not_smi_result, near_jump);
  }
}


void MacroAssembler::SmiSub(Register dst,
                            Register src1,
                            const Operand& src2) {
  // No overflow checking. Use only when it's known that
  // overflowing is impossible (e.g., subtracting two positive smis).
  if (!dst.is(src1)) {
    movq(dst, src1);
  }
  subq(dst, src2);
  Assert(no_overflow, "Smi subtraction overflow");
}


void MacroAssembler::SmiMul(Register dst,
                            Register src1,
                            Register src2,
                            Label* on_not_smi_result,
                            Label::Distance near_jump) {
  ASSERT(!dst.is(src2));
  ASSERT(!dst.is(kScratchRegister));
  ASSERT(!src1.is(kScratchRegister));
  ASSERT(!src2.is(kScratchRegister));

  if (dst.is(src1)) {
    Label failure, zero_correct_result;
    movq(kScratchRegister, src1);  // Create backup for later testing.
    SmiToInteger64(dst, src1);
    imul(dst, src2);
    j(overflow, &failure, Label::kNear);

    // Check for negative zero result.  If product is zero, and one
    // argument is negative, go to slow case.
    Label correct_result;
    testq(dst, dst);
    j(not_zero, &correct_result, Label::kNear);

    movq(dst, kScratchRegister);
    xor_(dst, src2);
    // Result was positive zero.
    j(positive, &zero_correct_result, Label::kNear);

    bind(&failure);  // Reused failure exit, restores src1.
    movq(src1, kScratchRegister);
    jmp(on_not_smi_result, near_jump);

    bind(&zero_correct_result);
    Set(dst, 0);

    bind(&correct_result);
  } else {
    SmiToInteger64(dst, src1);
    imul(dst, src2);
    j(overflow, on_not_smi_result, near_jump);
    // Check for negative zero result.  If product is zero, and one
    // argument is negative, go to slow case.
    Label correct_result;
    testq(dst, dst);
    j(not_zero, &correct_result, Label::kNear);
    // One of src1 and src2 is zero, the check whether the other is
    // negative.
    movq(kScratchRegister, src1);
    xor_(kScratchRegister, src2);
    j(negative, on_not_smi_result, near_jump);
    bind(&correct_result);
  }
}


void MacroAssembler::SmiDiv(Register dst,
                            Register src1,
                            Register src2,
                            Label* on_not_smi_result,
                            Label::Distance near_jump) {
  ASSERT(!src1.is(kScratchRegister));
  ASSERT(!src2.is(kScratchRegister));
  ASSERT(!dst.is(kScratchRegister));
  ASSERT(!src2.is(rax));
  ASSERT(!src2.is(rdx));
  ASSERT(!src1.is(rdx));

  // Check for 0 divisor (result is +/-Infinity).
  testq(src2, src2);
  j(zero, on_not_smi_result, near_jump);

  if (src1.is(rax)) {
    movq(kScratchRegister, src1);
  }
  SmiToInteger32(rax, src1);
  // We need to rule out dividing Smi::kMinValue by -1, since that would
  // overflow in idiv and raise an exception.
  // We combine this with negative zero test (negative zero only happens
  // when dividing zero by a negative number).

  // We overshoot a little and go to slow case if we divide min-value
  // by any negative value, not just -1.
  Label safe_div;
  testl(rax, Immediate(0x7fffffff));
  j(not_zero, &safe_div, Label::kNear);
  testq(src2, src2);
  if (src1.is(rax)) {
    j(positive, &safe_div, Label::kNear);
    movq(src1, kScratchRegister);
    jmp(on_not_smi_result, near_jump);
  } else {
    j(negative, on_not_smi_result, near_jump);
  }
  bind(&safe_div);

  SmiToInteger32(src2, src2);
  // Sign extend src1 into edx:eax.
  cdq();
  idivl(src2);
  Integer32ToSmi(src2, src2);
  // Check that the remainder is zero.
  testl(rdx, rdx);
  if (src1.is(rax)) {
    Label smi_result;
    j(zero, &smi_result, Label::kNear);
    movq(src1, kScratchRegister);
    jmp(on_not_smi_result, near_jump);
    bind(&smi_result);
  } else {
    j(not_zero, on_not_smi_result, near_jump);
  }
  if (!dst.is(src1) && src1.is(rax)) {
    movq(src1, kScratchRegister);
  }
  Integer32ToSmi(dst, rax);
}


void MacroAssembler::SmiMod(Register dst,
                            Register src1,
                            Register src2,
                            Label* on_not_smi_result,
                            Label::Distance near_jump) {
  ASSERT(!dst.is(kScratchRegister));
  ASSERT(!src1.is(kScratchRegister));
  ASSERT(!src2.is(kScratchRegister));
  ASSERT(!src2.is(rax));
  ASSERT(!src2.is(rdx));
  ASSERT(!src1.is(rdx));
  ASSERT(!src1.is(src2));

  testq(src2, src2);
  j(zero, on_not_smi_result, near_jump);

  if (src1.is(rax)) {
    movq(kScratchRegister, src1);
  }
  SmiToInteger32(rax, src1);
  SmiToInteger32(src2, src2);

  // Test for the edge case of dividing Smi::kMinValue by -1 (will overflow).
  Label safe_div;
  cmpl(rax, Immediate(Smi::kMinValue));
  j(not_equal, &safe_div, Label::kNear);
  cmpl(src2, Immediate(-1));
  j(not_equal, &safe_div, Label::kNear);
  // Retag inputs and go slow case.
  Integer32ToSmi(src2, src2);
  if (src1.is(rax)) {
    movq(src1, kScratchRegister);
  }
  jmp(on_not_smi_result, near_jump);
  bind(&safe_div);

  // Sign extend eax into edx:eax.
  cdq();
  idivl(src2);
  // Restore smi tags on inputs.
  Integer32ToSmi(src2, src2);
  if (src1.is(rax)) {
    movq(src1, kScratchRegister);
  }
  // Check for a negative zero result.  If the result is zero, and the
  // dividend is negative, go slow to return a floating point negative zero.
  Label smi_result;
  testl(rdx, rdx);
  j(not_zero, &smi_result, Label::kNear);
  testq(src1, src1);
  j(negative, on_not_smi_result, near_jump);
  bind(&smi_result);
  Integer32ToSmi(dst, rdx);
}


void MacroAssembler::SmiNot(Register dst, Register src) {
  ASSERT(!dst.is(kScratchRegister));
  ASSERT(!src.is(kScratchRegister));
  // Set tag and padding bits before negating, so that they are zero afterwards.
  movl(kScratchRegister, Immediate(~0));
  if (dst.is(src)) {
    xor_(dst, kScratchRegister);
  } else {
    lea(dst, Operand(src, kScratchRegister, times_1, 0));
  }
  not_(dst);
}


void MacroAssembler::SmiAnd(Register dst, Register src1, Register src2) {
  ASSERT(!dst.is(src2));
  if (!dst.is(src1)) {
    movq(dst, src1);
  }
  and_(dst, src2);
}


void MacroAssembler::SmiAndConstant(Register dst, Register src, Smi* constant) {
  if (constant->value() == 0) {
    Set(dst, 0);
  } else if (dst.is(src)) {
    ASSERT(!dst.is(kScratchRegister));
    Register constant_reg = GetSmiConstant(constant);
    and_(dst, constant_reg);
  } else {
    LoadSmiConstant(dst, constant);
    and_(dst, src);
  }
}


void MacroAssembler::SmiOr(Register dst, Register src1, Register src2) {
  if (!dst.is(src1)) {
    ASSERT(!src1.is(src2));
    movq(dst, src1);
  }
  or_(dst, src2);
}


void MacroAssembler::SmiOrConstant(Register dst, Register src, Smi* constant) {
  if (dst.is(src)) {
    ASSERT(!dst.is(kScratchRegister));
    Register constant_reg = GetSmiConstant(constant);
    or_(dst, constant_reg);
  } else {
    LoadSmiConstant(dst, constant);
    or_(dst, src);
  }
}


void MacroAssembler::SmiXor(Register dst, Register src1, Register src2) {
  if (!dst.is(src1)) {
    ASSERT(!src1.is(src2));
    movq(dst, src1);
  }
  xor_(dst, src2);
}


void MacroAssembler::SmiXorConstant(Register dst, Register src, Smi* constant) {
  if (dst.is(src)) {
    ASSERT(!dst.is(kScratchRegister));
    Register constant_reg = GetSmiConstant(constant);
    xor_(dst, constant_reg);
  } else {
    LoadSmiConstant(dst, constant);
    xor_(dst, src);
  }
}


void MacroAssembler::SmiShiftArithmeticRightConstant(Register dst,
                                                     Register src,
                                                     int shift_value) {
  ASSERT(is_uint5(shift_value));
  if (shift_value > 0) {
    if (dst.is(src)) {
      sar(dst, Immediate(shift_value + kSmiShift));
      shl(dst, Immediate(kSmiShift));
    } else {
      UNIMPLEMENTED();  // Not used.
    }
  }
}


void MacroAssembler::SmiShiftLeftConstant(Register dst,
                                          Register src,
                                          int shift_value) {
  if (!dst.is(src)) {
    movq(dst, src);
  }
  if (shift_value > 0) {
    shl(dst, Immediate(shift_value));
  }
}


void MacroAssembler::SmiShiftLogicalRightConstant(
    Register dst, Register src, int shift_value,
    Label* on_not_smi_result, Label::Distance near_jump) {
  // Logic right shift interprets its result as an *unsigned* number.
  if (dst.is(src)) {
    UNIMPLEMENTED();  // Not used.
  } else {
    movq(dst, src);
    if (shift_value == 0) {
      testq(dst, dst);
      j(negative, on_not_smi_result, near_jump);
    }
    shr(dst, Immediate(shift_value + kSmiShift));
    shl(dst, Immediate(kSmiShift));
  }
}


void MacroAssembler::SmiShiftLeft(Register dst,
                                  Register src1,
                                  Register src2) {
  ASSERT(!dst.is(rcx));
  // Untag shift amount.
  if (!dst.is(src1)) {
    movq(dst, src1);
  }
  SmiToInteger32(rcx, src2);
  // Shift amount specified by lower 5 bits, not six as the shl opcode.
  and_(rcx, Immediate(0x1f));
  shl_cl(dst);
}


void MacroAssembler::SmiShiftLogicalRight(Register dst,
                                          Register src1,
                                          Register src2,
                                          Label* on_not_smi_result,
                                          Label::Distance near_jump) {
  ASSERT(!dst.is(kScratchRegister));
  ASSERT(!src1.is(kScratchRegister));
  ASSERT(!src2.is(kScratchRegister));
  ASSERT(!dst.is(rcx));
  // dst and src1 can be the same, because the one case that bails out
  // is a shift by 0, which leaves dst, and therefore src1, unchanged.
  if (src1.is(rcx) || src2.is(rcx)) {
    movq(kScratchRegister, rcx);
  }
  if (!dst.is(src1)) {
    movq(dst, src1);
  }
  SmiToInteger32(rcx, src2);
  orl(rcx, Immediate(kSmiShift));
  shr_cl(dst);  // Shift is rcx modulo 0x1f + 32.
  shl(dst, Immediate(kSmiShift));
  testq(dst, dst);
  if (src1.is(rcx) || src2.is(rcx)) {
    Label positive_result;
    j(positive, &positive_result, Label::kNear);
    if (src1.is(rcx)) {
      movq(src1, kScratchRegister);
    } else {
      movq(src2, kScratchRegister);
    }
    jmp(on_not_smi_result, near_jump);
    bind(&positive_result);
  } else {
    // src2 was zero and src1 negative.
    j(negative, on_not_smi_result, near_jump);
  }
}


void MacroAssembler::SmiShiftArithmeticRight(Register dst,
                                             Register src1,
                                             Register src2) {
  ASSERT(!dst.is(kScratchRegister));
  ASSERT(!src1.is(kScratchRegister));
  ASSERT(!src2.is(kScratchRegister));
  ASSERT(!dst.is(rcx));
  if (src1.is(rcx)) {
    movq(kScratchRegister, src1);
  } else if (src2.is(rcx)) {
    movq(kScratchRegister, src2);
  }
  if (!dst.is(src1)) {
    movq(dst, src1);
  }
  SmiToInteger32(rcx, src2);
  orl(rcx, Immediate(kSmiShift));
  sar_cl(dst);  // Shift 32 + original rcx & 0x1f.
  shl(dst, Immediate(kSmiShift));
  if (src1.is(rcx)) {
    movq(src1, kScratchRegister);
  } else if (src2.is(rcx)) {
    movq(src2, kScratchRegister);
  }
}


void MacroAssembler::SelectNonSmi(Register dst,
                                  Register src1,
                                  Register src2,
                                  Label* on_not_smis,
                                  Label::Distance near_jump) {
  ASSERT(!dst.is(kScratchRegister));
  ASSERT(!src1.is(kScratchRegister));
  ASSERT(!src2.is(kScratchRegister));
  ASSERT(!dst.is(src1));
  ASSERT(!dst.is(src2));
  // Both operands must not be smis.
#ifdef DEBUG
  if (allow_stub_calls()) {  // Check contains a stub call.
    Condition not_both_smis = NegateCondition(CheckBothSmi(src1, src2));
    Check(not_both_smis, "Both registers were smis in SelectNonSmi.");
  }
#endif
  STATIC_ASSERT(kSmiTag == 0);
  ASSERT_EQ(0, Smi::FromInt(0));
  movl(kScratchRegister, Immediate(kSmiTagMask));
  and_(kScratchRegister, src1);
  testl(kScratchRegister, src2);
  // If non-zero then both are smis.
  j(not_zero, on_not_smis, near_jump);

  // Exactly one operand is a smi.
  ASSERT_EQ(1, static_cast<int>(kSmiTagMask));
  // kScratchRegister still holds src1 & kSmiTag, which is either zero or one.
  subq(kScratchRegister, Immediate(1));
  // If src1 is a smi, then scratch register all 1s, else it is all 0s.
  movq(dst, src1);
  xor_(dst, src2);
  and_(dst, kScratchRegister);
  // If src1 is a smi, dst holds src1 ^ src2, else it is zero.
  xor_(dst, src1);
  // If src1 is a smi, dst is src2, else it is src1, i.e., the non-smi.
}


SmiIndex MacroAssembler::SmiToIndex(Register dst,
                                    Register src,
                                    int shift) {
  ASSERT(is_uint6(shift));
  // There is a possible optimization if shift is in the range 60-63, but that
  // will (and must) never happen.
  if (!dst.is(src)) {
    movq(dst, src);
  }
  if (shift < kSmiShift) {
    sar(dst, Immediate(kSmiShift - shift));
  } else {
    shl(dst, Immediate(shift - kSmiShift));
  }
  return SmiIndex(dst, times_1);
}

SmiIndex MacroAssembler::SmiToNegativeIndex(Register dst,
                                            Register src,
                                            int shift) {
  // Register src holds a positive smi.
  ASSERT(is_uint6(shift));
  if (!dst.is(src)) {
    movq(dst, src);
  }
  neg(dst);
  if (shift < kSmiShift) {
    sar(dst, Immediate(kSmiShift - shift));
  } else {
    shl(dst, Immediate(shift - kSmiShift));
  }
  return SmiIndex(dst, times_1);
}


void MacroAssembler::AddSmiField(Register dst, const Operand& src) {
  ASSERT_EQ(0, kSmiShift % kBitsPerByte);
  addl(dst, Operand(src, kSmiShift / kBitsPerByte));
}


void MacroAssembler::JumpIfNotString(Register object,
                                     Register object_map,
                                     Label* not_string,
                                     Label::Distance near_jump) {
  Condition is_smi = CheckSmi(object);
  j(is_smi, not_string, near_jump);
  CmpObjectType(object, FIRST_NONSTRING_TYPE, object_map);
  j(above_equal, not_string, near_jump);
}


void MacroAssembler::JumpIfNotBothSequentialAsciiStrings(
    Register first_object,
    Register second_object,
    Register scratch1,
    Register scratch2,
    Label* on_fail,
    Label::Distance near_jump) {
  // Check that both objects are not smis.
  Condition either_smi = CheckEitherSmi(first_object, second_object);
  j(either_smi, on_fail, near_jump);

  // Load instance type for both strings.
  movq(scratch1, FieldOperand(first_object, HeapObject::kMapOffset));
  movq(scratch2, FieldOperand(second_object, HeapObject::kMapOffset));
  movzxbl(scratch1, FieldOperand(scratch1, Map::kInstanceTypeOffset));
  movzxbl(scratch2, FieldOperand(scratch2, Map::kInstanceTypeOffset));

  // Check that both are flat ASCII strings.
  ASSERT(kNotStringTag != 0);
  const int kFlatAsciiStringMask =
      kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask;
  const int kFlatAsciiStringTag = ASCII_STRING_TYPE;

  andl(scratch1, Immediate(kFlatAsciiStringMask));
  andl(scratch2, Immediate(kFlatAsciiStringMask));
  // Interleave the bits to check both scratch1 and scratch2 in one test.
  ASSERT_EQ(0, kFlatAsciiStringMask & (kFlatAsciiStringMask << 3));
  lea(scratch1, Operand(scratch1, scratch2, times_8, 0));
  cmpl(scratch1,
       Immediate(kFlatAsciiStringTag + (kFlatAsciiStringTag << 3)));
  j(not_equal, on_fail, near_jump);
}


void MacroAssembler::JumpIfInstanceTypeIsNotSequentialAscii(
    Register instance_type,
    Register scratch,
    Label* failure,
    Label::Distance near_jump) {
  if (!scratch.is(instance_type)) {
    movl(scratch, instance_type);
  }

  const int kFlatAsciiStringMask =
      kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask;

  andl(scratch, Immediate(kFlatAsciiStringMask));
  cmpl(scratch, Immediate(kStringTag | kSeqStringTag | kAsciiStringTag));
  j(not_equal, failure, near_jump);
}


void MacroAssembler::JumpIfBothInstanceTypesAreNotSequentialAscii(
    Register first_object_instance_type,
    Register second_object_instance_type,
    Register scratch1,
    Register scratch2,
    Label* on_fail,
    Label::Distance near_jump) {
  // Load instance type for both strings.
  movq(scratch1, first_object_instance_type);
  movq(scratch2, second_object_instance_type);

  // Check that both are flat ASCII strings.
  ASSERT(kNotStringTag != 0);
  const int kFlatAsciiStringMask =
      kIsNotStringMask | kStringRepresentationMask | kStringEncodingMask;
  const int kFlatAsciiStringTag = ASCII_STRING_TYPE;

  andl(scratch1, Immediate(kFlatAsciiStringMask));
  andl(scratch2, Immediate(kFlatAsciiStringMask));
  // Interleave the bits to check both scratch1 and scratch2 in one test.
  ASSERT_EQ(0, kFlatAsciiStringMask & (kFlatAsciiStringMask << 3));
  lea(scratch1, Operand(scratch1, scratch2, times_8, 0));
  cmpl(scratch1,
       Immediate(kFlatAsciiStringTag + (kFlatAsciiStringTag << 3)));
  j(not_equal, on_fail, near_jump);
}



void MacroAssembler::Move(Register dst, Register src) {
  if (!dst.is(src)) {
    movq(dst, src);
  }
}


void MacroAssembler::Move(Register dst, Handle<Object> source) {
  ASSERT(!source->IsFailure());
  if (source->IsSmi()) {
    Move(dst, Smi::cast(*source));
  } else {
    movq(dst, source, RelocInfo::EMBEDDED_OBJECT);
  }
}


void MacroAssembler::Move(const Operand& dst, Handle<Object> source) {
  ASSERT(!source->IsFailure());
  if (source->IsSmi()) {
    Move(dst, Smi::cast(*source));
  } else {
    movq(kScratchRegister, source, RelocInfo::EMBEDDED_OBJECT);
    movq(dst, kScratchRegister);
  }
}


void MacroAssembler::Cmp(Register dst, Handle<Object> source) {
  if (source->IsSmi()) {
    Cmp(dst, Smi::cast(*source));
  } else {
    Move(kScratchRegister, source);
    cmpq(dst, kScratchRegister);
  }
}


void MacroAssembler::Cmp(const Operand& dst, Handle<Object> source) {
  if (source->IsSmi()) {
    Cmp(dst, Smi::cast(*source));
  } else {
    ASSERT(source->IsHeapObject());
    movq(kScratchRegister, source, RelocInfo::EMBEDDED_OBJECT);
    cmpq(dst, kScratchRegister);
  }
}


void MacroAssembler::Push(Handle<Object> source) {
  if (source->IsSmi()) {
    Push(Smi::cast(*source));
  } else {
    ASSERT(source->IsHeapObject());
    movq(kScratchRegister, source, RelocInfo::EMBEDDED_OBJECT);
    push(kScratchRegister);
  }
}


void MacroAssembler::LoadHeapObject(Register result,
                                    Handle<HeapObject> object) {
  if (isolate()->heap()->InNewSpace(*object)) {
    Handle<JSGlobalPropertyCell> cell =
        isolate()->factory()->NewJSGlobalPropertyCell(object);
    movq(result, cell, RelocInfo::GLOBAL_PROPERTY_CELL);
    movq(result, Operand(result, 0));
  } else {
    Move(result, object);
  }
}


void MacroAssembler::PushHeapObject(Handle<HeapObject> object) {
  if (isolate()->heap()->InNewSpace(*object)) {
    Handle<JSGlobalPropertyCell> cell =
        isolate()->factory()->NewJSGlobalPropertyCell(object);
    movq(kScratchRegister, cell, RelocInfo::GLOBAL_PROPERTY_CELL);
    movq(kScratchRegister, Operand(kScratchRegister, 0));
    push(kScratchRegister);
  } else {
    Push(object);
  }
}


void MacroAssembler::LoadGlobalCell(Register dst,
                                    Handle<JSGlobalPropertyCell> cell) {
  if (dst.is(rax)) {
    load_rax(cell.location(), RelocInfo::GLOBAL_PROPERTY_CELL);
  } else {
    movq(dst, cell, RelocInfo::GLOBAL_PROPERTY_CELL);
    movq(dst, Operand(dst, 0));
  }
}


void MacroAssembler::Push(Smi* source) {
  intptr_t smi = reinterpret_cast<intptr_t>(source);
  if (is_int32(smi)) {
    push(Immediate(static_cast<int32_t>(smi)));
  } else {
    Register constant = GetSmiConstant(source);
    push(constant);
  }
}


void MacroAssembler::Drop(int stack_elements) {
  if (stack_elements > 0) {
    addq(rsp, Immediate(stack_elements * kPointerSize));
  }
}


void MacroAssembler::Test(const Operand& src, Smi* source) {
  testl(Operand(src, kIntSize), Immediate(source->value()));
}


void MacroAssembler::TestBit(const Operand& src, int bits) {
  int byte_offset = bits / kBitsPerByte;
  int bit_in_byte = bits & (kBitsPerByte - 1);
  testb(Operand(src, byte_offset), Immediate(1 << bit_in_byte));
}


void MacroAssembler::Jump(ExternalReference ext) {
  LoadAddress(kScratchRegister, ext);
  jmp(kScratchRegister);
}


void MacroAssembler::Jump(Address destination, RelocInfo::Mode rmode) {
  movq(kScratchRegister, destination, rmode);
  jmp(kScratchRegister);
}


void MacroAssembler::Jump(Handle<Code> code_object, RelocInfo::Mode rmode) {
  // TODO(X64): Inline this
  jmp(code_object, rmode);
}


int MacroAssembler::CallSize(ExternalReference ext) {
  // Opcode for call kScratchRegister is: Rex.B FF D4 (three bytes).
  const int kCallInstructionSize = 3;
  return LoadAddressSize(ext) + kCallInstructionSize;
}


void MacroAssembler::Call(ExternalReference ext) {
#ifdef DEBUG
  int end_position = pc_offset() + CallSize(ext);
#endif
  LoadAddress(kScratchRegister, ext);
  call(kScratchRegister);
#ifdef DEBUG
  CHECK_EQ(end_position, pc_offset());
#endif
}


void MacroAssembler::Call(Address destination, RelocInfo::Mode rmode) {
#ifdef DEBUG
  int end_position = pc_offset() + CallSize(destination, rmode);
#endif
  movq(kScratchRegister, destination, rmode);
  call(kScratchRegister);
#ifdef DEBUG
  CHECK_EQ(pc_offset(), end_position);
#endif
}


void MacroAssembler::Call(Handle<Code> code_object,
                          RelocInfo::Mode rmode,
                          unsigned ast_id) {
#ifdef DEBUG
  int end_position = pc_offset() + CallSize(code_object);
#endif
  ASSERT(RelocInfo::IsCodeTarget(rmode));
  call(code_object, rmode, ast_id);
#ifdef DEBUG
  CHECK_EQ(end_position, pc_offset());
#endif
}


void MacroAssembler::Pushad() {
  push(rax);
  push(rcx);
  push(rdx);
  push(rbx);
  // Not pushing rsp or rbp.
  push(rsi);
  push(rdi);
  push(r8);
  push(r9);
  // r10 is kScratchRegister.
  push(r11);
  // r12 is kSmiConstantRegister.
  // r13 is kRootRegister.
  push(r14);
  push(r15);
  STATIC_ASSERT(11 == kNumSafepointSavedRegisters);
  // Use lea for symmetry with Popad.
  int sp_delta =
      (kNumSafepointRegisters - kNumSafepointSavedRegisters) * kPointerSize;
  lea(rsp, Operand(rsp, -sp_delta));
}


void MacroAssembler::Popad() {
  // Popad must not change the flags, so use lea instead of addq.
  int sp_delta =
      (kNumSafepointRegisters - kNumSafepointSavedRegisters) * kPointerSize;
  lea(rsp, Operand(rsp, sp_delta));
  pop(r15);
  pop(r14);
  pop(r11);
  pop(r9);
  pop(r8);
  pop(rdi);
  pop(rsi);
  pop(rbx);
  pop(rdx);
  pop(rcx);
  pop(rax);
}


void MacroAssembler::Dropad() {
  addq(rsp, Immediate(kNumSafepointRegisters * kPointerSize));
}


// Order general registers are pushed by Pushad:
// rax, rcx, rdx, rbx, rsi, rdi, r8, r9, r11, r14, r15.
const int
MacroAssembler::kSafepointPushRegisterIndices[Register::kNumRegisters] = {
    0,
    1,
    2,
    3,
    -1,
    -1,
    4,
    5,
    6,
    7,
    -1,
    8,
    -1,
    -1,
    9,
    10
};


void MacroAssembler::StoreToSafepointRegisterSlot(Register dst, Register src) {
  movq(SafepointRegisterSlot(dst), src);
}


void MacroAssembler::LoadFromSafepointRegisterSlot(Register dst, Register src) {
  movq(dst, SafepointRegisterSlot(src));
}


Operand MacroAssembler::SafepointRegisterSlot(Register reg) {
  return Operand(rsp, SafepointRegisterStackIndex(reg.code()) * kPointerSize);
}


void MacroAssembler::PushTryHandler(StackHandler::Kind kind,
                                    int handler_index) {
  // Adjust this code if not the case.
  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);

  // We will build up the handler from the bottom by pushing on the stack.
  // First push the frame pointer and context.
  if (kind == StackHandler::JS_ENTRY) {
    // The frame pointer does not point to a JS frame so we save NULL for
    // rbp. We expect the code throwing an exception to check rbp before
    // dereferencing it to restore the context.
    push(Immediate(0));  // NULL frame pointer.
    Push(Smi::FromInt(0));  // No context.
  } else {
    push(rbp);
    push(rsi);
  }

  // Push the state and the code object.
  unsigned state =
      StackHandler::IndexField::encode(handler_index) |
      StackHandler::KindField::encode(kind);
  push(Immediate(state));
  Push(CodeObject());

  // Link the current handler as the next handler.
  ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
  push(ExternalOperand(handler_address));
  // Set this new handler as the current one.
  movq(ExternalOperand(handler_address), rsp);
}


void MacroAssembler::PopTryHandler() {
  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
  ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
  pop(ExternalOperand(handler_address));
  addq(rsp, Immediate(StackHandlerConstants::kSize - kPointerSize));
}


void MacroAssembler::JumpToHandlerEntry() {
  // Compute the handler entry address and jump to it.  The handler table is
  // a fixed array of (smi-tagged) code offsets.
  // rax = exception, rdi = code object, rdx = state.
  movq(rbx, FieldOperand(rdi, Code::kHandlerTableOffset));
  shr(rdx, Immediate(StackHandler::kKindWidth));
  movq(rdx, FieldOperand(rbx, rdx, times_8, FixedArray::kHeaderSize));
  SmiToInteger64(rdx, rdx);
  lea(rdi, FieldOperand(rdi, rdx, times_1, Code::kHeaderSize));
  jmp(rdi);
}


void MacroAssembler::Throw(Register value) {
  // Adjust this code if not the case.
  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);

  // The exception is expected in rax.
  if (!value.is(rax)) {
    movq(rax, value);
  }
  // Drop the stack pointer to the top of the top handler.
  ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
  movq(rsp, ExternalOperand(handler_address));
  // Restore the next handler.
  pop(ExternalOperand(handler_address));

  // Remove the code object and state, compute the handler address in rdi.
  pop(rdi);  // Code object.
  pop(rdx);  // Offset and state.

  // Restore the context and frame pointer.
  pop(rsi);  // Context.
  pop(rbp);  // Frame pointer.

  // If the handler is a JS frame, restore the context to the frame.
  // (kind == ENTRY) == (rbp == 0) == (rsi == 0), so we could test either
  // rbp or rsi.
  Label skip;
  testq(rsi, rsi);
  j(zero, &skip, Label::kNear);
  movq(Operand(rbp, StandardFrameConstants::kContextOffset), rsi);
  bind(&skip);

  JumpToHandlerEntry();
}


void MacroAssembler::ThrowUncatchable(Register value) {
  // Adjust this code if not the case.
  STATIC_ASSERT(StackHandlerConstants::kSize == 5 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kNextOffset == 0);
  STATIC_ASSERT(StackHandlerConstants::kCodeOffset == 1 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kStateOffset == 2 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kContextOffset == 3 * kPointerSize);
  STATIC_ASSERT(StackHandlerConstants::kFPOffset == 4 * kPointerSize);

  // The exception is expected in rax.
  if (!value.is(rax)) {
    movq(rax, value);
  }
  // Drop the stack pointer to the top of the top stack handler.
  ExternalReference handler_address(Isolate::kHandlerAddress, isolate());
  Load(rsp, handler_address);

  // Unwind the handlers until the top ENTRY handler is found.
  Label fetch_next, check_kind;
  jmp(&check_kind, Label::kNear);
  bind(&fetch_next);
  movq(rsp, Operand(rsp, StackHandlerConstants::kNextOffset));

  bind(&check_kind);
  STATIC_ASSERT(StackHandler::JS_ENTRY == 0);
  testl(Operand(rsp, StackHandlerConstants::kStateOffset),
        Immediate(StackHandler::KindField::kMask));
  j(not_zero, &fetch_next);

  // Set the top handler address to next handler past the top ENTRY handler.
  pop(ExternalOperand(handler_address));

  // Remove the code object and state, compute the handler address in rdi.
  pop(rdi);  // Code object.
  pop(rdx);  // Offset and state.

  // Clear the context pointer and frame pointer (0 was saved in the handler).
  pop(rsi);
  pop(rbp);

  JumpToHandlerEntry();
}


void MacroAssembler::Ret() {
  ret(0);
}


void MacroAssembler::Ret(int bytes_dropped, Register scratch) {
  if (is_uint16(bytes_dropped)) {
    ret(bytes_dropped);
  } else {
    pop(scratch);
    addq(rsp, Immediate(bytes_dropped));
    push(scratch);
    ret(0);
  }
}


void MacroAssembler::FCmp() {
  fucomip();
  fstp(0);
}


void MacroAssembler::CmpObjectType(Register heap_object,
                                   InstanceType type,
                                   Register map) {
  movq(map, FieldOperand(heap_object, HeapObject::kMapOffset));
  CmpInstanceType(map, type);
}


void MacroAssembler::CmpInstanceType(Register map, InstanceType type) {
  cmpb(FieldOperand(map, Map::kInstanceTypeOffset),
       Immediate(static_cast<int8_t>(type)));
}


void MacroAssembler::CheckFastElements(Register map,
                                       Label* fail,
                                       Label::Distance distance) {
  STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
  STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
  STATIC_ASSERT(FAST_ELEMENTS == 2);
  STATIC_ASSERT(FAST_HOLEY_ELEMENTS == 3);
  cmpb(FieldOperand(map, Map::kBitField2Offset),
       Immediate(Map::kMaximumBitField2FastHoleyElementValue));
  j(above, fail, distance);
}


void MacroAssembler::CheckFastObjectElements(Register map,
                                             Label* fail,
                                             Label::Distance distance) {
  STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
  STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
  STATIC_ASSERT(FAST_ELEMENTS == 2);
  STATIC_ASSERT(FAST_HOLEY_ELEMENTS == 3);
  cmpb(FieldOperand(map, Map::kBitField2Offset),
       Immediate(Map::kMaximumBitField2FastHoleySmiElementValue));
  j(below_equal, fail, distance);
  cmpb(FieldOperand(map, Map::kBitField2Offset),
       Immediate(Map::kMaximumBitField2FastHoleyElementValue));
  j(above, fail, distance);
}


void MacroAssembler::CheckFastSmiElements(Register map,
                                          Label* fail,
                                          Label::Distance distance) {
  STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
  STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
  cmpb(FieldOperand(map, Map::kBitField2Offset),
       Immediate(Map::kMaximumBitField2FastHoleySmiElementValue));
  j(above, fail, distance);
}


void MacroAssembler::StoreNumberToDoubleElements(
    Register maybe_number,
    Register elements,
    Register index,
    XMMRegister xmm_scratch,
    Label* fail) {
  Label smi_value, is_nan, maybe_nan, not_nan, have_double_value, done;

  JumpIfSmi(maybe_number, &smi_value, Label::kNear);

  CheckMap(maybe_number,
           isolate()->factory()->heap_number_map(),
           fail,
           DONT_DO_SMI_CHECK);

  // Double value, canonicalize NaN.
  uint32_t offset = HeapNumber::kValueOffset + sizeof(kHoleNanLower32);
  cmpl(FieldOperand(maybe_number, offset),
       Immediate(kNaNOrInfinityLowerBoundUpper32));
  j(greater_equal, &maybe_nan, Label::kNear);

  bind(&not_nan);
  movsd(xmm_scratch, FieldOperand(maybe_number, HeapNumber::kValueOffset));
  bind(&have_double_value);
  movsd(FieldOperand(elements, index, times_8, FixedDoubleArray::kHeaderSize),
        xmm_scratch);
  jmp(&done);

  bind(&maybe_nan);
  // Could be NaN or Infinity. If fraction is not zero, it's NaN, otherwise
  // it's an Infinity, and the non-NaN code path applies.
  j(greater, &is_nan, Label::kNear);
  cmpl(FieldOperand(maybe_number, HeapNumber::kValueOffset), Immediate(0));
  j(zero, &not_nan);
  bind(&is_nan);
  // Convert all NaNs to the same canonical NaN value when they are stored in
  // the double array.
  Set(kScratchRegister, BitCast<uint64_t>(
      FixedDoubleArray::canonical_not_the_hole_nan_as_double()));
  movq(xmm_scratch, kScratchRegister);
  jmp(&have_double_value, Label::kNear);

  bind(&smi_value);
  // Value is a smi. convert to a double and store.
  // Preserve original value.
  SmiToInteger32(kScratchRegister, maybe_number);
  cvtlsi2sd(xmm_scratch, kScratchRegister);
  movsd(FieldOperand(elements, index, times_8, FixedDoubleArray::kHeaderSize),
        xmm_scratch);
  bind(&done);
}


void MacroAssembler::CompareMap(Register obj,
                                Handle<Map> map,
                                Label* early_success,
                                CompareMapMode mode) {
  Cmp(FieldOperand(obj, HeapObject::kMapOffset), map);
  if (mode == ALLOW_ELEMENT_TRANSITION_MAPS) {
    ElementsKind kind = map->elements_kind();
    if (IsFastElementsKind(kind)) {
      bool packed = IsFastPackedElementsKind(kind);
      Map* current_map = *map;
      while (CanTransitionToMoreGeneralFastElementsKind(kind, packed)) {
        kind = GetNextMoreGeneralFastElementsKind(kind, packed);
        current_map = current_map->LookupElementsTransitionMap(kind);
        if (!current_map) break;
        j(equal, early_success, Label::kNear);
        Cmp(FieldOperand(obj, HeapObject::kMapOffset),
            Handle<Map>(current_map));
      }
    }
  }
}


void MacroAssembler::CheckMap(Register obj,
                              Handle<Map> map,
                              Label* fail,
                              SmiCheckType smi_check_type,
                              CompareMapMode mode) {
  if (smi_check_type == DO_SMI_CHECK) {
    JumpIfSmi(obj, fail);
  }

  Label success;
  CompareMap(obj, map, &success, mode);
  j(not_equal, fail);
  bind(&success);
}


void MacroAssembler::ClampUint8(Register reg) {
  Label done;
  testl(reg, Immediate(0xFFFFFF00));
  j(zero, &done, Label::kNear);
  setcc(negative, reg);  // 1 if negative, 0 if positive.
  decb(reg);  // 0 if negative, 255 if positive.
  bind(&done);
}


void MacroAssembler::ClampDoubleToUint8(XMMRegister input_reg,
                                        XMMRegister temp_xmm_reg,
                                        Register result_reg,
                                        Register temp_reg) {
  Label done;
  Set(result_reg, 0);
  xorps(temp_xmm_reg, temp_xmm_reg);
  ucomisd(input_reg, temp_xmm_reg);
  j(below, &done, Label::kNear);
  uint64_t one_half = BitCast<uint64_t, double>(0.5);
  Set(temp_reg, one_half);
  movq(temp_xmm_reg, temp_reg);
  addsd(temp_xmm_reg, input_reg);
  cvttsd2si(result_reg, temp_xmm_reg);
  testl(result_reg, Immediate(0xFFFFFF00));
  j(zero, &done, Label::kNear);
  Set(result_reg, 255);
  bind(&done);
}


void MacroAssembler::LoadInstanceDescriptors(Register map,
                                             Register descriptors) {
  movq(descriptors, FieldOperand(map,
                                 Map::kInstanceDescriptorsOrBackPointerOffset));

  Label ok, fail;
  CheckMap(descriptors,
           isolate()->factory()->fixed_array_map(),
           &fail,
           DONT_DO_SMI_CHECK);
  jmp(&ok);
  bind(&fail);
  Move(descriptors, isolate()->factory()->empty_descriptor_array());
  bind(&ok);
}


void MacroAssembler::DispatchMap(Register obj,
                                 Handle<Map> map,
                                 Handle<Code> success,
                                 SmiCheckType smi_check_type) {
  Label fail;
  if (smi_check_type == DO_SMI_CHECK) {
    JumpIfSmi(obj, &fail);
  }
  Cmp(FieldOperand(obj, HeapObject::kMapOffset), map);
  j(equal, success, RelocInfo::CODE_TARGET);

  bind(&fail);
}


void MacroAssembler::AbortIfNotNumber(Register object) {
  Label ok;
  Condition is_smi = CheckSmi(object);
  j(is_smi, &ok, Label::kNear);
  Cmp(FieldOperand(object, HeapObject::kMapOffset),
      isolate()->factory()->heap_number_map());
  Assert(equal, "Operand not a number");
  bind(&ok);
}


void MacroAssembler::AbortIfSmi(Register object) {
  Condition is_smi = CheckSmi(object);
  Assert(NegateCondition(is_smi), "Operand is a smi");
}


void MacroAssembler::AbortIfNotSmi(Register object) {
  Condition is_smi = CheckSmi(object);
  Assert(is_smi, "Operand is not a smi");
}


void MacroAssembler::AbortIfNotSmi(const Operand& object) {
  Condition is_smi = CheckSmi(object);
  Assert(is_smi, "Operand is not a smi");
}


void MacroAssembler::AbortIfNotZeroExtended(Register int32_register) {
  ASSERT(!int32_register.is(kScratchRegister));
  movq(kScratchRegister, 0x100000000l, RelocInfo::NONE);
  cmpq(kScratchRegister, int32_register);
  Assert(above_equal, "32 bit value in register is not zero-extended");
}


void MacroAssembler::AbortIfNotString(Register object) {
  testb(object, Immediate(kSmiTagMask));
  Assert(not_equal, "Operand is not a string");
  push(object);
  movq(object, FieldOperand(object, HeapObject::kMapOffset));
  CmpInstanceType(object, FIRST_NONSTRING_TYPE);
  pop(object);
  Assert(below, "Operand is not a string");
}


void MacroAssembler::AbortIfNotRootValue(Register src,
                                         Heap::RootListIndex root_value_index,
                                         const char* message) {
  ASSERT(!src.is(kScratchRegister));
  LoadRoot(kScratchRegister, root_value_index);
  cmpq(src, kScratchRegister);
  Check(equal, message);
}



Condition MacroAssembler::IsObjectStringType(Register heap_object,
                                             Register map,
                                             Register instance_type) {
  movq(map, FieldOperand(heap_object, HeapObject::kMapOffset));
  movzxbl(instance_type, FieldOperand(map, Map::kInstanceTypeOffset));
  STATIC_ASSERT(kNotStringTag != 0);
  testb(instance_type, Immediate(kIsNotStringMask));
  return zero;
}


void MacroAssembler::TryGetFunctionPrototype(Register function,
                                             Register result,
                                             Label* miss,
                                             bool miss_on_bound_function) {
  // Check that the receiver isn't a smi.
  testl(function, Immediate(kSmiTagMask));
  j(zero, miss);

  // Check that the function really is a function.
  CmpObjectType(function, JS_FUNCTION_TYPE, result);
  j(not_equal, miss);

  if (miss_on_bound_function) {
    movq(kScratchRegister,
         FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
    // It's not smi-tagged (stored in the top half of a smi-tagged 8-byte
    // field).
    TestBit(FieldOperand(kScratchRegister,
                         SharedFunctionInfo::kCompilerHintsOffset),
            SharedFunctionInfo::kBoundFunction);
    j(not_zero, miss);
  }

  // Make sure that the function has an instance prototype.
  Label non_instance;
  testb(FieldOperand(result, Map::kBitFieldOffset),
        Immediate(1 << Map::kHasNonInstancePrototype));
  j(not_zero, &non_instance, Label::kNear);

  // Get the prototype or initial map from the function.
  movq(result,
       FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset));

  // If the prototype or initial map is the hole, don't return it and
  // simply miss the cache instead. This will allow us to allocate a
  // prototype object on-demand in the runtime system.
  CompareRoot(result, Heap::kTheHoleValueRootIndex);
  j(equal, miss);

  // If the function does not have an initial map, we're done.
  Label done;
  CmpObjectType(result, MAP_TYPE, kScratchRegister);
  j(not_equal, &done, Label::kNear);

  // Get the prototype from the initial map.
  movq(result, FieldOperand(result, Map::kPrototypeOffset));
  jmp(&done, Label::kNear);

  // Non-instance prototype: Fetch prototype from constructor field
  // in initial map.
  bind(&non_instance);
  movq(result, FieldOperand(result, Map::kConstructorOffset));

  // All done.
  bind(&done);
}


void MacroAssembler::SetCounter(StatsCounter* counter, int value) {
  if (FLAG_native_code_counters && counter->Enabled()) {
    Operand counter_operand = ExternalOperand(ExternalReference(counter));
    movl(counter_operand, Immediate(value));
  }
}


void MacroAssembler::IncrementCounter(StatsCounter* counter, int value) {
  ASSERT(value > 0);
  if (FLAG_native_code_counters && counter->Enabled()) {
    Operand counter_operand = ExternalOperand(ExternalReference(counter));
    if (value == 1) {
      incl(counter_operand);
    } else {
      addl(counter_operand, Immediate(value));
    }
  }
}


void MacroAssembler::DecrementCounter(StatsCounter* counter, int value) {
  ASSERT(value > 0);
  if (FLAG_native_code_counters && counter->Enabled()) {
    Operand counter_operand = ExternalOperand(ExternalReference(counter));
    if (value == 1) {
      decl(counter_operand);
    } else {
      subl(counter_operand, Immediate(value));
    }
  }
}


#ifdef ENABLE_DEBUGGER_SUPPORT
void MacroAssembler::DebugBreak() {
  Set(rax, 0);  // No arguments.
  LoadAddress(rbx, ExternalReference(Runtime::kDebugBreak, isolate()));
  CEntryStub ces(1);
  ASSERT(AllowThisStubCall(&ces));
  Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
}
#endif  // ENABLE_DEBUGGER_SUPPORT


void MacroAssembler::SetCallKind(Register dst, CallKind call_kind) {
  // This macro takes the dst register to make the code more readable
  // at the call sites. However, the dst register has to be rcx to
  // follow the calling convention which requires the call type to be
  // in rcx.
  ASSERT(dst.is(rcx));
  if (call_kind == CALL_AS_FUNCTION) {
    LoadSmiConstant(dst, Smi::FromInt(1));
  } else {
    LoadSmiConstant(dst, Smi::FromInt(0));
  }
}


void MacroAssembler::InvokeCode(Register code,
                                const ParameterCount& expected,
                                const ParameterCount& actual,
                                InvokeFlag flag,
                                const CallWrapper& call_wrapper,
                                CallKind call_kind) {
  // You can't call a function without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  Label done;
  bool definitely_mismatches = false;
  InvokePrologue(expected,
                 actual,
                 Handle<Code>::null(),
                 code,
                 &done,
                 &definitely_mismatches,
                 flag,
                 Label::kNear,
                 call_wrapper,
                 call_kind);
  if (!definitely_mismatches) {
    if (flag == CALL_FUNCTION) {
      call_wrapper.BeforeCall(CallSize(code));
      SetCallKind(rcx, call_kind);
      call(code);
      call_wrapper.AfterCall();
    } else {
      ASSERT(flag == JUMP_FUNCTION);
      SetCallKind(rcx, call_kind);
      jmp(code);
    }
    bind(&done);
  }
}


void MacroAssembler::InvokeCode(Handle<Code> code,
                                const ParameterCount& expected,
                                const ParameterCount& actual,
                                RelocInfo::Mode rmode,
                                InvokeFlag flag,
                                const CallWrapper& call_wrapper,
                                CallKind call_kind) {
  // You can't call a function without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  Label done;
  bool definitely_mismatches = false;
  Register dummy = rax;
  InvokePrologue(expected,
                 actual,
                 code,
                 dummy,
                 &done,
                 &definitely_mismatches,
                 flag,
                 Label::kNear,
                 call_wrapper,
                 call_kind);
  if (!definitely_mismatches) {
    if (flag == CALL_FUNCTION) {
      call_wrapper.BeforeCall(CallSize(code));
      SetCallKind(rcx, call_kind);
      Call(code, rmode);
      call_wrapper.AfterCall();
    } else {
      ASSERT(flag == JUMP_FUNCTION);
      SetCallKind(rcx, call_kind);
      Jump(code, rmode);
    }
    bind(&done);
  }
}


void MacroAssembler::InvokeFunction(Register function,
                                    const ParameterCount& actual,
                                    InvokeFlag flag,
                                    const CallWrapper& call_wrapper,
                                    CallKind call_kind) {
  // You can't call a function without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  ASSERT(function.is(rdi));
  movq(rdx, FieldOperand(function, JSFunction::kSharedFunctionInfoOffset));
  movq(rsi, FieldOperand(function, JSFunction::kContextOffset));
  movsxlq(rbx,
          FieldOperand(rdx, SharedFunctionInfo::kFormalParameterCountOffset));
  // Advances rdx to the end of the Code object header, to the start of
  // the executable code.
  movq(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));

  ParameterCount expected(rbx);
  InvokeCode(rdx, expected, actual, flag, call_wrapper, call_kind);
}


void MacroAssembler::InvokeFunction(Handle<JSFunction> function,
                                    const ParameterCount& actual,
                                    InvokeFlag flag,
                                    const CallWrapper& call_wrapper,
                                    CallKind call_kind) {
  // You can't call a function without a valid frame.
  ASSERT(flag == JUMP_FUNCTION || has_frame());

  // Get the function and setup the context.
  LoadHeapObject(rdi, function);
  movq(rsi, FieldOperand(rdi, JSFunction::kContextOffset));

  // We call indirectly through the code field in the function to
  // allow recompilation to take effect without changing any of the
  // call sites.
  movq(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
  ParameterCount expected(function->shared()->formal_parameter_count());
  InvokeCode(rdx, expected, actual, flag, call_wrapper, call_kind);
}


void MacroAssembler::InvokePrologue(const ParameterCount& expected,
                                    const ParameterCount& actual,
                                    Handle<Code> code_constant,
                                    Register code_register,
                                    Label* done,
                                    bool* definitely_mismatches,
                                    InvokeFlag flag,
                                    Label::Distance near_jump,
                                    const CallWrapper& call_wrapper,
                                    CallKind call_kind) {
  bool definitely_matches = false;
  *definitely_mismatches = false;
  Label invoke;
  if (expected.is_immediate()) {
    ASSERT(actual.is_immediate());
    if (expected.immediate() == actual.immediate()) {
      definitely_matches = true;
    } else {
      Set(rax, actual.immediate());
      if (expected.immediate() ==
              SharedFunctionInfo::kDontAdaptArgumentsSentinel) {
        // Don't worry about adapting arguments for built-ins that
        // don't want that done. Skip adaption code by making it look
        // like we have a match between expected and actual number of
        // arguments.
        definitely_matches = true;
      } else {
        *definitely_mismatches = true;
        Set(rbx, expected.immediate());
      }
    }
  } else {
    if (actual.is_immediate()) {
      // Expected is in register, actual is immediate. This is the
      // case when we invoke function values without going through the
      // IC mechanism.
      cmpq(expected.reg(), Immediate(actual.immediate()));
      j(equal, &invoke, Label::kNear);
      ASSERT(expected.reg().is(rbx));
      Set(rax, actual.immediate());
    } else if (!expected.reg().is(actual.reg())) {
      // Both expected and actual are in (different) registers. This
      // is the case when we invoke functions using call and apply.
      cmpq(expected.reg(), actual.reg());
      j(equal, &invoke, Label::kNear);
      ASSERT(actual.reg().is(rax));
      ASSERT(expected.reg().is(rbx));
    }
  }

  if (!definitely_matches) {
    Handle<Code> adaptor = isolate()->builtins()->ArgumentsAdaptorTrampoline();
    if (!code_constant.is_null()) {
      movq(rdx, code_constant, RelocInfo::EMBEDDED_OBJECT);
      addq(rdx, Immediate(Code::kHeaderSize - kHeapObjectTag));
    } else if (!code_register.is(rdx)) {
      movq(rdx, code_register);
    }

    if (flag == CALL_FUNCTION) {
      call_wrapper.BeforeCall(CallSize(adaptor));
      SetCallKind(rcx, call_kind);
      Call(adaptor, RelocInfo::CODE_TARGET);
      call_wrapper.AfterCall();
      if (!*definitely_mismatches) {
        jmp(done, near_jump);
      }
    } else {
      SetCallKind(rcx, call_kind);
      Jump(adaptor, RelocInfo::CODE_TARGET);
    }
    bind(&invoke);
  }
}


void MacroAssembler::EnterFrame(StackFrame::Type type) {
  push(rbp);
  movq(rbp, rsp);
  push(rsi);  // Context.
  Push(Smi::FromInt(type));
  movq(kScratchRegister, CodeObject(), RelocInfo::EMBEDDED_OBJECT);
  push(kScratchRegister);
  if (emit_debug_code()) {
    movq(kScratchRegister,
         isolate()->factory()->undefined_value(),
         RelocInfo::EMBEDDED_OBJECT);
    cmpq(Operand(rsp, 0), kScratchRegister);
    Check(not_equal, "code object not properly patched");
  }
}


void MacroAssembler::LeaveFrame(StackFrame::Type type) {
  if (emit_debug_code()) {
    Move(kScratchRegister, Smi::FromInt(type));
    cmpq(Operand(rbp, StandardFrameConstants::kMarkerOffset), kScratchRegister);
    Check(equal, "stack frame types must match");
  }
  movq(rsp, rbp);
  pop(rbp);
}


void MacroAssembler::EnterExitFramePrologue(bool save_rax) {
  // Set up the frame structure on the stack.
  // All constants are relative to the frame pointer of the exit frame.
  ASSERT(ExitFrameConstants::kCallerSPDisplacement == +2 * kPointerSize);
  ASSERT(ExitFrameConstants::kCallerPCOffset == +1 * kPointerSize);
  ASSERT(ExitFrameConstants::kCallerFPOffset ==  0 * kPointerSize);
  push(rbp);
  movq(rbp, rsp);

  // Reserve room for entry stack pointer and push the code object.
  ASSERT(ExitFrameConstants::kSPOffset == -1 * kPointerSize);
  push(Immediate(0));  // Saved entry sp, patched before call.
  movq(kScratchRegister, CodeObject(), RelocInfo::EMBEDDED_OBJECT);
  push(kScratchRegister);  // Accessed from EditFrame::code_slot.

  // Save the frame pointer and the context in top.
  if (save_rax) {
    movq(r14, rax);  // Backup rax in callee-save register.
  }

  Store(ExternalReference(Isolate::kCEntryFPAddress, isolate()), rbp);
  Store(ExternalReference(Isolate::kContextAddress, isolate()), rsi);
}


void MacroAssembler::EnterExitFrameEpilogue(int arg_stack_space,
                                            bool save_doubles) {
#ifdef _WIN64
  const int kShadowSpace = 4;
  arg_stack_space += kShadowSpace;
#endif
  // Optionally save all XMM registers.
  if (save_doubles) {
    int space = XMMRegister::kNumRegisters * kDoubleSize +
        arg_stack_space * kPointerSize;
    subq(rsp, Immediate(space));
    int offset = -2 * kPointerSize;
    for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; i++) {
      XMMRegister reg = XMMRegister::FromAllocationIndex(i);
      movsd(Operand(rbp, offset - ((i + 1) * kDoubleSize)), reg);
    }
  } else if (arg_stack_space > 0) {
    subq(rsp, Immediate(arg_stack_space * kPointerSize));
  }

  // Get the required frame alignment for the OS.
  const int kFrameAlignment = OS::ActivationFrameAlignment();
  if (kFrameAlignment > 0) {
    ASSERT(IsPowerOf2(kFrameAlignment));
    ASSERT(is_int8(kFrameAlignment));
    and_(rsp, Immediate(-kFrameAlignment));
  }

  // Patch the saved entry sp.
  movq(Operand(rbp, ExitFrameConstants::kSPOffset), rsp);
}


void MacroAssembler::EnterExitFrame(int arg_stack_space, bool save_doubles) {
  EnterExitFramePrologue(true);

  // Set up argv in callee-saved register r15. It is reused in LeaveExitFrame,
  // so it must be retained across the C-call.
  int offset = StandardFrameConstants::kCallerSPOffset - kPointerSize;
  lea(r15, Operand(rbp, r14, times_pointer_size, offset));

  EnterExitFrameEpilogue(arg_stack_space, save_doubles);
}


void MacroAssembler::EnterApiExitFrame(int arg_stack_space) {
  EnterExitFramePrologue(false);
  EnterExitFrameEpilogue(arg_stack_space, false);
}


void MacroAssembler::LeaveExitFrame(bool save_doubles) {
  // Registers:
  // r15 : argv
  if (save_doubles) {
    int offset = -2 * kPointerSize;
    for (int i = 0; i < XMMRegister::kNumAllocatableRegisters; i++) {
      XMMRegister reg = XMMRegister::FromAllocationIndex(i);
      movsd(reg, Operand(rbp, offset - ((i + 1) * kDoubleSize)));
    }
  }
  // Get the return address from the stack and restore the frame pointer.
  movq(rcx, Operand(rbp, 1 * kPointerSize));
  movq(rbp, Operand(rbp, 0 * kPointerSize));

  // Drop everything up to and including the arguments and the receiver
  // from the caller stack.
  lea(rsp, Operand(r15, 1 * kPointerSize));

  // Push the return address to get ready to return.
  push(rcx);

  LeaveExitFrameEpilogue();
}


void MacroAssembler::LeaveApiExitFrame() {
  movq(rsp, rbp);
  pop(rbp);

  LeaveExitFrameEpilogue();
}


void MacroAssembler::LeaveExitFrameEpilogue() {
  // Restore current context from top and clear it in debug mode.
  ExternalReference context_address(Isolate::kContextAddress, isolate());
  Operand context_operand = ExternalOperand(context_address);
  movq(rsi, context_operand);
#ifdef DEBUG
  movq(context_operand, Immediate(0));
#endif

  // Clear the top frame.
  ExternalReference c_entry_fp_address(Isolate::kCEntryFPAddress,
                                       isolate());
  Operand c_entry_fp_operand = ExternalOperand(c_entry_fp_address);
  movq(c_entry_fp_operand, Immediate(0));
}


void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
                                            Register scratch,
                                            Label* miss) {
  Label same_contexts;

  ASSERT(!holder_reg.is(scratch));
  ASSERT(!scratch.is(kScratchRegister));
  // Load current lexical context from the stack frame.
  movq(scratch, Operand(rbp, StandardFrameConstants::kContextOffset));

  // When generating debug code, make sure the lexical context is set.
  if (emit_debug_code()) {
    cmpq(scratch, Immediate(0));
    Check(not_equal, "we should not have an empty lexical context");
  }
  // Load the global context of the current context.
  int offset = Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
  movq(scratch, FieldOperand(scratch, offset));
  movq(scratch, FieldOperand(scratch, GlobalObject::kGlobalContextOffset));

  // Check the context is a global context.
  if (emit_debug_code()) {
    Cmp(FieldOperand(scratch, HeapObject::kMapOffset),
        isolate()->factory()->global_context_map());
    Check(equal, "JSGlobalObject::global_context should be a global context.");
  }

  // Check if both contexts are the same.
  cmpq(scratch, FieldOperand(holder_reg, JSGlobalProxy::kContextOffset));
  j(equal, &same_contexts);

  // Compare security tokens.
  // Check that the security token in the calling global object is
  // compatible with the security token in the receiving global
  // object.

  // Check the context is a global context.
  if (emit_debug_code()) {
    // Preserve original value of holder_reg.
    push(holder_reg);
    movq(holder_reg, FieldOperand(holder_reg, JSGlobalProxy::kContextOffset));
    CompareRoot(holder_reg, Heap::kNullValueRootIndex);
    Check(not_equal, "JSGlobalProxy::context() should not be null.");

    // Read the first word and compare to global_context_map(),
    movq(holder_reg, FieldOperand(holder_reg, HeapObject::kMapOffset));
    CompareRoot(holder_reg, Heap::kGlobalContextMapRootIndex);
    Check(equal, "JSGlobalObject::global_context should be a global context.");
    pop(holder_reg);
  }

  movq(kScratchRegister,
       FieldOperand(holder_reg, JSGlobalProxy::kContextOffset));
  int token_offset =
      Context::kHeaderSize + Context::SECURITY_TOKEN_INDEX * kPointerSize;
  movq(scratch, FieldOperand(scratch, token_offset));
  cmpq(scratch, FieldOperand(kScratchRegister, token_offset));
  j(not_equal, miss);

  bind(&same_contexts);
}


void MacroAssembler::GetNumberHash(Register r0, Register scratch) {
  // First of all we assign the hash seed to scratch.
  LoadRoot(scratch, Heap::kHashSeedRootIndex);
  SmiToInteger32(scratch, scratch);

  // Xor original key with a seed.
  xorl(r0, scratch);

  // Compute the hash code from the untagged key.  This must be kept in sync
  // with ComputeIntegerHash in utils.h.
  //
  // hash = ~hash + (hash << 15);
  movl(scratch, r0);
  notl(r0);
  shll(scratch, Immediate(15));
  addl(r0, scratch);
  // hash = hash ^ (hash >> 12);
  movl(scratch, r0);
  shrl(scratch, Immediate(12));
  xorl(r0, scratch);
  // hash = hash + (hash << 2);
  leal(r0, Operand(r0, r0, times_4, 0));
  // hash = hash ^ (hash >> 4);
  movl(scratch, r0);
  shrl(scratch, Immediate(4));
  xorl(r0, scratch);
  // hash = hash * 2057;
  imull(r0, r0, Immediate(2057));
  // hash = hash ^ (hash >> 16);
  movl(scratch, r0);
  shrl(scratch, Immediate(16));
  xorl(r0, scratch);
}



void MacroAssembler::LoadFromNumberDictionary(Label* miss,
                                              Register elements,
                                              Register key,
                                              Register r0,
                                              Register r1,
                                              Register r2,
                                              Register result) {
  // Register use:
  //
  // elements - holds the slow-case elements of the receiver on entry.
  //            Unchanged unless 'result' is the same register.
  //
  // key      - holds the smi key on entry.
  //            Unchanged unless 'result' is the same register.
  //
  // Scratch registers:
  //
  // r0 - holds the untagged key on entry and holds the hash once computed.
  //
  // r1 - used to hold the capacity mask of the dictionary
  //
  // r2 - used for the index into the dictionary.
  //
  // result - holds the result on exit if the load succeeded.
  //          Allowed to be the same as 'key' or 'result'.
  //          Unchanged on bailout so 'key' or 'result' can be used
  //          in further computation.

  Label done;

  GetNumberHash(r0, r1);

  // Compute capacity mask.
  SmiToInteger32(r1, FieldOperand(elements,
                                  SeededNumberDictionary::kCapacityOffset));
  decl(r1);

  // Generate an unrolled loop that performs a few probes before giving up.
  const int kProbes = 4;
  for (int i = 0; i < kProbes; i++) {
    // Use r2 for index calculations and keep the hash intact in r0.
    movq(r2, r0);
    // Compute the masked index: (hash + i + i * i) & mask.
    if (i > 0) {
      addl(r2, Immediate(SeededNumberDictionary::GetProbeOffset(i)));
    }
    and_(r2, r1);

    // Scale the index by multiplying by the entry size.
    ASSERT(SeededNumberDictionary::kEntrySize == 3);
    lea(r2, Operand(r2, r2, times_2, 0));  // r2 = r2 * 3

    // Check if the key matches.
    cmpq(key, FieldOperand(elements,
                           r2,
                           times_pointer_size,
                           SeededNumberDictionary::kElementsStartOffset));
    if (i != (kProbes - 1)) {
      j(equal, &done);
    } else {
      j(not_equal, miss);
    }
  }

  bind(&done);
  // Check that the value is a normal propety.
  const int kDetailsOffset =
      SeededNumberDictionary::kElementsStartOffset + 2 * kPointerSize;
  ASSERT_EQ(NORMAL, 0);
  Test(FieldOperand(elements, r2, times_pointer_size, kDetailsOffset),
       Smi::FromInt(PropertyDetails::TypeField::kMask));
  j(not_zero, miss);

  // Get the value at the masked, scaled index.
  const int kValueOffset =
      SeededNumberDictionary::kElementsStartOffset + kPointerSize;
  movq(result, FieldOperand(elements, r2, times_pointer_size, kValueOffset));
}


void MacroAssembler::LoadAllocationTopHelper(Register result,
                                             Register scratch,
                                             AllocationFlags flags) {
  ExternalReference new_space_allocation_top =
      ExternalReference::new_space_allocation_top_address(isolate());

  // Just return if allocation top is already known.
  if ((flags & RESULT_CONTAINS_TOP) != 0) {
    // No use of scratch if allocation top is provided.
    ASSERT(!scratch.is_valid());
#ifdef DEBUG
    // Assert that result actually contains top on entry.
    Operand top_operand = ExternalOperand(new_space_allocation_top);
    cmpq(result, top_operand);
    Check(equal, "Unexpected allocation top");
#endif
    return;
  }

  // Move address of new object to result. Use scratch register if available,
  // and keep address in scratch until call to UpdateAllocationTopHelper.
  if (scratch.is_valid()) {
    LoadAddress(scratch, new_space_allocation_top);
    movq(result, Operand(scratch, 0));
  } else {
    Load(result, new_space_allocation_top);
  }
}


void MacroAssembler::UpdateAllocationTopHelper(Register result_end,
                                               Register scratch) {
  if (emit_debug_code()) {
    testq(result_end, Immediate(kObjectAlignmentMask));
    Check(zero, "Unaligned allocation in new space");
  }

  ExternalReference new_space_allocation_top =
      ExternalReference::new_space_allocation_top_address(isolate());

  // Update new top.
  if (scratch.is_valid()) {
    // Scratch already contains address of allocation top.
    movq(Operand(scratch, 0), result_end);
  } else {
    Store(new_space_allocation_top, result_end);
  }
}


void MacroAssembler::AllocateInNewSpace(int object_size,
                                        Register result,
                                        Register result_end,
                                        Register scratch,
                                        Label* gc_required,
                                        AllocationFlags flags) {
  if (!FLAG_inline_new) {
    if (emit_debug_code()) {
      // Trash the registers to simulate an allocation failure.
      movl(result, Immediate(0x7091));
      if (result_end.is_valid()) {
        movl(result_end, Immediate(0x7191));
      }
      if (scratch.is_valid()) {
        movl(scratch, Immediate(0x7291));
      }
    }
    jmp(gc_required);
    return;
  }
  ASSERT(!result.is(result_end));

  // Load address of new object into result.
  LoadAllocationTopHelper(result, scratch, flags);

  // Calculate new top and bail out if new space is exhausted.
  ExternalReference new_space_allocation_limit =
      ExternalReference::new_space_allocation_limit_address(isolate());

  Register top_reg = result_end.is_valid() ? result_end : result;

  if (!top_reg.is(result)) {
    movq(top_reg, result);
  }
  addq(top_reg, Immediate(object_size));
  j(carry, gc_required);
  Operand limit_operand = ExternalOperand(new_space_allocation_limit);
  cmpq(top_reg, limit_operand);
  j(above, gc_required);

  // Update allocation top.
  UpdateAllocationTopHelper(top_reg, scratch);

  if (top_reg.is(result)) {
    if ((flags & TAG_OBJECT) != 0) {
      subq(result, Immediate(object_size - kHeapObjectTag));
    } else {
      subq(result, Immediate(object_size));
    }
  } else if ((flags & TAG_OBJECT) != 0) {
    // Tag the result if requested.
    addq(result, Immediate(kHeapObjectTag));
  }
}


void MacroAssembler::AllocateInNewSpace(int header_size,
                                        ScaleFactor element_size,
                                        Register element_count,
                                        Register result,
                                        Register result_end,
                                        Register scratch,
                                        Label* gc_required,
                                        AllocationFlags flags) {
  if (!FLAG_inline_new) {
    if (emit_debug_code()) {
      // Trash the registers to simulate an allocation failure.
      movl(result, Immediate(0x7091));
      movl(result_end, Immediate(0x7191));
      if (scratch.is_valid()) {
        movl(scratch, Immediate(0x7291));
      }
      // Register element_count is not modified by the function.
    }
    jmp(gc_required);
    return;
  }
  ASSERT(!result.is(result_end));

  // Load address of new object into result.
  LoadAllocationTopHelper(result, scratch, flags);

  // Calculate new top and bail out if new space is exhausted.
  ExternalReference new_space_allocation_limit =
      ExternalReference::new_space_allocation_limit_address(isolate());

  // We assume that element_count*element_size + header_size does not
  // overflow.
  lea(result_end, Operand(element_count, element_size, header_size));
  addq(result_end, result);
  j(carry, gc_required);
  Operand limit_operand = ExternalOperand(new_space_allocation_limit);
  cmpq(result_end, limit_operand);
  j(above, gc_required);

  // Update allocation top.
  UpdateAllocationTopHelper(result_end, scratch);

  // Tag the result if requested.
  if ((flags & TAG_OBJECT) != 0) {
    addq(result, Immediate(kHeapObjectTag));
  }
}


void MacroAssembler::AllocateInNewSpace(Register object_size,
                                        Register result,
                                        Register result_end,
                                        Register scratch,
                                        Label* gc_required,
                                        AllocationFlags flags) {
  if (!FLAG_inline_new) {
    if (emit_debug_code()) {
      // Trash the registers to simulate an allocation failure.
      movl(result, Immediate(0x7091));
      movl(result_end, Immediate(0x7191));
      if (scratch.is_valid()) {
        movl(scratch, Immediate(0x7291));
      }
      // object_size is left unchanged by this function.
    }
    jmp(gc_required);
    return;
  }
  ASSERT(!result.is(result_end));

  // Load address of new object into result.
  LoadAllocationTopHelper(result, scratch, flags);

  // Calculate new top and bail out if new space is exhausted.
  ExternalReference new_space_allocation_limit =
      ExternalReference::new_space_allocation_limit_address(isolate());
  if (!object_size.is(result_end)) {
    movq(result_end, object_size);
  }
  addq(result_end, result);
  j(carry, gc_required);
  Operand limit_operand = ExternalOperand(new_space_allocation_limit);
  cmpq(result_end, limit_operand);
  j(above, gc_required);

  // Update allocation top.
  UpdateAllocationTopHelper(result_end, scratch);

  // Tag the result if requested.
  if ((flags & TAG_OBJECT) != 0) {
    addq(result, Immediate(kHeapObjectTag));
  }
}


void MacroAssembler::UndoAllocationInNewSpace(Register object) {
  ExternalReference new_space_allocation_top =
      ExternalReference::new_space_allocation_top_address(isolate());

  // Make sure the object has no tag before resetting top.
  and_(object, Immediate(~kHeapObjectTagMask));
  Operand top_operand = ExternalOperand(new_space_allocation_top);
#ifdef DEBUG
  cmpq(object, top_operand);
  Check(below, "Undo allocation of non allocated memory");
#endif
  movq(top_operand, object);
}


void MacroAssembler::AllocateHeapNumber(Register result,
                                        Register scratch,
                                        Label* gc_required) {
  // Allocate heap number in new space.
  AllocateInNewSpace(HeapNumber::kSize,
                     result,
                     scratch,
                     no_reg,
                     gc_required,
                     TAG_OBJECT);

  // Set the map.
  LoadRoot(kScratchRegister, Heap::kHeapNumberMapRootIndex);
  movq(FieldOperand(result, HeapObject::kMapOffset), kScratchRegister);
}


void MacroAssembler::AllocateTwoByteString(Register result,
                                           Register length,
                                           Register scratch1,
                                           Register scratch2,
                                           Register scratch3,
                                           Label* gc_required) {
  // Calculate the number of bytes needed for the characters in the string while
  // observing object alignment.
  const int kHeaderAlignment = SeqTwoByteString::kHeaderSize &
                               kObjectAlignmentMask;
  ASSERT(kShortSize == 2);
  // scratch1 = length * 2 + kObjectAlignmentMask.
  lea(scratch1, Operand(length, length, times_1, kObjectAlignmentMask +
                kHeaderAlignment));
  and_(scratch1, Immediate(~kObjectAlignmentMask));
  if (kHeaderAlignment > 0) {
    subq(scratch1, Immediate(kHeaderAlignment));
  }

  // Allocate two byte string in new space.
  AllocateInNewSpace(SeqTwoByteString::kHeaderSize,
                     times_1,
                     scratch1,
                     result,
                     scratch2,
                     scratch3,
                     gc_required,
                     TAG_OBJECT);

  // Set the map, length and hash field.
  LoadRoot(kScratchRegister, Heap::kStringMapRootIndex);
  movq(FieldOperand(result, HeapObject::kMapOffset), kScratchRegister);
  Integer32ToSmi(scratch1, length);
  movq(FieldOperand(result, String::kLengthOffset), scratch1);
  movq(FieldOperand(result, String::kHashFieldOffset),
       Immediate(String::kEmptyHashField));
}


void MacroAssembler::AllocateAsciiString(Register result,
                                         Register length,
                                         Register scratch1,
                                         Register scratch2,
                                         Register scratch3,
                                         Label* gc_required) {
  // Calculate the number of bytes needed for the characters in the string while
  // observing object alignment.
  const int kHeaderAlignment = SeqAsciiString::kHeaderSize &
                               kObjectAlignmentMask;
  movl(scratch1, length);
  ASSERT(kCharSize == 1);
  addq(scratch1, Immediate(kObjectAlignmentMask + kHeaderAlignment));
  and_(scratch1, Immediate(~kObjectAlignmentMask));
  if (kHeaderAlignment > 0) {
    subq(scratch1, Immediate(kHeaderAlignment));
  }

  // Allocate ASCII string in new space.
  AllocateInNewSpace(SeqAsciiString::kHeaderSize,
                     times_1,
                     scratch1,
                     result,
                     scratch2,
                     scratch3,
                     gc_required,
                     TAG_OBJECT);

  // Set the map, length and hash field.
  LoadRoot(kScratchRegister, Heap::kAsciiStringMapRootIndex);
  movq(FieldOperand(result, HeapObject::kMapOffset), kScratchRegister);
  Integer32ToSmi(scratch1, length);
  movq(FieldOperand(result, String::kLengthOffset), scratch1);
  movq(FieldOperand(result, String::kHashFieldOffset),
       Immediate(String::kEmptyHashField));
}


void MacroAssembler::AllocateTwoByteConsString(Register result,
                                        Register scratch1,
                                        Register scratch2,
                                        Label* gc_required) {
  // Allocate heap number in new space.
  AllocateInNewSpace(ConsString::kSize,
                     result,
                     scratch1,
                     scratch2,
                     gc_required,
                     TAG_OBJECT);

  // Set the map. The other fields are left uninitialized.
  LoadRoot(kScratchRegister, Heap::kConsStringMapRootIndex);
  movq(FieldOperand(result, HeapObject::kMapOffset), kScratchRegister);
}


void MacroAssembler::AllocateAsciiConsString(Register result,
                                             Register scratch1,
                                             Register scratch2,
                                             Label* gc_required) {
  // Allocate heap number in new space.
  AllocateInNewSpace(ConsString::kSize,
                     result,
                     scratch1,
                     scratch2,
                     gc_required,
                     TAG_OBJECT);

  // Set the map. The other fields are left uninitialized.
  LoadRoot(kScratchRegister, Heap::kConsAsciiStringMapRootIndex);
  movq(FieldOperand(result, HeapObject::kMapOffset), kScratchRegister);
}


void MacroAssembler::AllocateTwoByteSlicedString(Register result,
                                          Register scratch1,
                                          Register scratch2,
                                          Label* gc_required) {
  // Allocate heap number in new space.
  AllocateInNewSpace(SlicedString::kSize,
                     result,
                     scratch1,
                     scratch2,
                     gc_required,
                     TAG_OBJECT);

  // Set the map. The other fields are left uninitialized.
  LoadRoot(kScratchRegister, Heap::kSlicedStringMapRootIndex);
  movq(FieldOperand(result, HeapObject::kMapOffset), kScratchRegister);
}


void MacroAssembler::AllocateAsciiSlicedString(Register result,
                                               Register scratch1,
                                               Register scratch2,
                                               Label* gc_required) {
  // Allocate heap number in new space.
  AllocateInNewSpace(SlicedString::kSize,
                     result,
                     scratch1,
                     scratch2,
                     gc_required,
                     TAG_OBJECT);

  // Set the map. The other fields are left uninitialized.
  LoadRoot(kScratchRegister, Heap::kSlicedAsciiStringMapRootIndex);
  movq(FieldOperand(result, HeapObject::kMapOffset), kScratchRegister);
}


// Copy memory, byte-by-byte, from source to destination.  Not optimized for
// long or aligned copies.  The contents of scratch and length are destroyed.
// Destination is incremented by length, source, length and scratch are
// clobbered.
// A simpler loop is faster on small copies, but slower on large ones.
// The cld() instruction must have been emitted, to set the direction flag(),
// before calling this function.
void MacroAssembler::CopyBytes(Register destination,
                               Register source,
                               Register length,
                               int min_length,
                               Register scratch) {
  ASSERT(min_length >= 0);
  if (FLAG_debug_code) {
    cmpl(length, Immediate(min_length));
    Assert(greater_equal, "Invalid min_length");
  }
  Label loop, done, short_string, short_loop;

  const int kLongStringLimit = 20;
  if (min_length <= kLongStringLimit) {
    cmpl(length, Immediate(kLongStringLimit));
    j(less_equal, &short_string);
  }

  ASSERT(source.is(rsi));
  ASSERT(destination.is(rdi));
  ASSERT(length.is(rcx));

  // Because source is 8-byte aligned in our uses of this function,
  // we keep source aligned for the rep movs operation by copying the odd bytes
  // at the end of the ranges.
  movq(scratch, length);
  shrl(length, Immediate(3));
  repmovsq();
  // Move remaining bytes of length.
  andl(scratch, Immediate(0x7));
  movq(length, Operand(source, scratch, times_1, -8));
  movq(Operand(destination, scratch, times_1, -8), length);
  addq(destination, scratch);

  if (min_length <= kLongStringLimit) {
    jmp(&done);

    bind(&short_string);
    if (min_length == 0) {
      testl(length, length);
      j(zero, &done);
    }
    lea(scratch, Operand(destination, length, times_1, 0));

    bind(&short_loop);
    movb(length, Operand(source, 0));
    movb(Operand(destination, 0), length);
    incq(source);
    incq(destination);
    cmpq(destination, scratch);
    j(not_equal, &short_loop);

    bind(&done);
  }
}


void MacroAssembler::InitializeFieldsWithFiller(Register start_offset,
                                                Register end_offset,
                                                Register filler) {
  Label loop, entry;
  jmp(&entry);
  bind(&loop);
  movq(Operand(start_offset, 0), filler);
  addq(start_offset, Immediate(kPointerSize));
  bind(&entry);
  cmpq(start_offset, end_offset);
  j(less, &loop);
}


void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
  if (context_chain_length > 0) {
    // Move up the chain of contexts to the context containing the slot.
    movq(dst, Operand(rsi, Context::SlotOffset(Context::PREVIOUS_INDEX)));
    for (int i = 1; i < context_chain_length; i++) {
      movq(dst, Operand(dst, Context::SlotOffset(Context::PREVIOUS_INDEX)));
    }
  } else {
    // Slot is in the current function context.  Move it into the
    // destination register in case we store into it (the write barrier
    // cannot be allowed to destroy the context in rsi).
    movq(dst, rsi);
  }

  // We should not have found a with context by walking the context
  // chain (i.e., the static scope chain and runtime context chain do
  // not agree).  A variable occurring in such a scope should have
  // slot type LOOKUP and not CONTEXT.
  if (emit_debug_code()) {
    CompareRoot(FieldOperand(dst, HeapObject::kMapOffset),
                Heap::kWithContextMapRootIndex);
    Check(not_equal, "Variable resolved to with context.");
  }
}


void MacroAssembler::LoadTransitionedArrayMapConditional(
    ElementsKind expected_kind,
    ElementsKind transitioned_kind,
    Register map_in_out,
    Register scratch,
    Label* no_map_match) {
  // Load the global or builtins object from the current context.
  movq(scratch, Operand(rsi, Context::SlotOffset(Context::GLOBAL_INDEX)));
  movq(scratch, FieldOperand(scratch, GlobalObject::kGlobalContextOffset));

  // Check that the function's map is the same as the expected cached map.
  movq(scratch, Operand(scratch,
                        Context::SlotOffset(Context::JS_ARRAY_MAPS_INDEX)));

  int offset = expected_kind * kPointerSize +
      FixedArrayBase::kHeaderSize;
  cmpq(map_in_out, FieldOperand(scratch, offset));
  j(not_equal, no_map_match);

  // Use the transitioned cached map.
  offset = transitioned_kind * kPointerSize +
      FixedArrayBase::kHeaderSize;
  movq(map_in_out, FieldOperand(scratch, offset));
}


void MacroAssembler::LoadInitialArrayMap(
    Register function_in, Register scratch,
    Register map_out, bool can_have_holes) {
  ASSERT(!function_in.is(map_out));
  Label done;
  movq(map_out, FieldOperand(function_in,
                             JSFunction::kPrototypeOrInitialMapOffset));
  if (!FLAG_smi_only_arrays) {
    ElementsKind kind = can_have_holes ? FAST_HOLEY_ELEMENTS : FAST_ELEMENTS;
    LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                        kind,
                                        map_out,
                                        scratch,
                                        &done);
  } else if (can_have_holes) {
    LoadTransitionedArrayMapConditional(FAST_SMI_ELEMENTS,
                                        FAST_HOLEY_SMI_ELEMENTS,
                                        map_out,
                                        scratch,
                                        &done);
  }
  bind(&done);
}

#ifdef _WIN64
static const int kRegisterPassedArguments = 4;
#else
static const int kRegisterPassedArguments = 6;
#endif

void MacroAssembler::LoadGlobalFunction(int index, Register function) {
  // Load the global or builtins object from the current context.
  movq(function, Operand(rsi, Context::SlotOffset(Context::GLOBAL_INDEX)));
  // Load the global context from the global or builtins object.
  movq(function, FieldOperand(function, GlobalObject::kGlobalContextOffset));
  // Load the function from the global context.
  movq(function, Operand(function, Context::SlotOffset(index)));
}


void MacroAssembler::LoadGlobalFunctionInitialMap(Register function,
                                                  Register map) {
  // Load the initial map.  The global functions all have initial maps.
  movq(map, FieldOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
  if (emit_debug_code()) {
    Label ok, fail;
    CheckMap(map, isolate()->factory()->meta_map(), &fail, DO_SMI_CHECK);
    jmp(&ok);
    bind(&fail);
    Abort("Global functions must have initial map");
    bind(&ok);
  }
}


int MacroAssembler::ArgumentStackSlotsForCFunctionCall(int num_arguments) {
  // On Windows 64 stack slots are reserved by the caller for all arguments
  // including the ones passed in registers, and space is always allocated for
  // the four register arguments even if the function takes fewer than four
  // arguments.
  // On AMD64 ABI (Linux/Mac) the first six arguments are passed in registers
  // and the caller does not reserve stack slots for them.
  ASSERT(num_arguments >= 0);
#ifdef _WIN64
  const int kMinimumStackSlots = kRegisterPassedArguments;
  if (num_arguments < kMinimumStackSlots) return kMinimumStackSlots;
  return num_arguments;
#else
  if (num_arguments < kRegisterPassedArguments) return 0;
  return num_arguments - kRegisterPassedArguments;
#endif
}


void MacroAssembler::PrepareCallCFunction(int num_arguments) {
  int frame_alignment = OS::ActivationFrameAlignment();
  ASSERT(frame_alignment != 0);
  ASSERT(num_arguments >= 0);

  // Make stack end at alignment and allocate space for arguments and old rsp.
  movq(kScratchRegister, rsp);
  ASSERT(IsPowerOf2(frame_alignment));
  int argument_slots_on_stack =
      ArgumentStackSlotsForCFunctionCall(num_arguments);
  subq(rsp, Immediate((argument_slots_on_stack + 1) * kPointerSize));
  and_(rsp, Immediate(-frame_alignment));
  movq(Operand(rsp, argument_slots_on_stack * kPointerSize), kScratchRegister);
}


void MacroAssembler::CallCFunction(ExternalReference function,
                                   int num_arguments) {
  LoadAddress(rax, function);
  CallCFunction(rax, num_arguments);
}


void MacroAssembler::CallCFunction(Register function, int num_arguments) {
  ASSERT(has_frame());
  // Check stack alignment.
  if (emit_debug_code()) {
    CheckStackAlignment();
  }

  call(function);
  ASSERT(OS::ActivationFrameAlignment() != 0);
  ASSERT(num_arguments >= 0);
  int argument_slots_on_stack =
      ArgumentStackSlotsForCFunctionCall(num_arguments);
  movq(rsp, Operand(rsp, argument_slots_on_stack * kPointerSize));
}


bool AreAliased(Register r1, Register r2, Register r3, Register r4) {
  if (r1.is(r2)) return true;
  if (r1.is(r3)) return true;
  if (r1.is(r4)) return true;
  if (r2.is(r3)) return true;
  if (r2.is(r4)) return true;
  if (r3.is(r4)) return true;
  return false;
}


CodePatcher::CodePatcher(byte* address, int size)
    : address_(address),
      size_(size),
      masm_(NULL, address, size + Assembler::kGap) {
  // Create a new macro assembler pointing to the address of the code to patch.
  // The size is adjusted with kGap on order for the assembler to generate size
  // bytes of instructions without failing with buffer size constraints.
  ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
}


CodePatcher::~CodePatcher() {
  // Indicate that code has changed.
  CPU::FlushICache(address_, size_);

  // Check that the code was patched as expected.
  ASSERT(masm_.pc_ == address_ + size_);
  ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
}


void MacroAssembler::CheckPageFlag(
    Register object,
    Register scratch,
    int mask,
    Condition cc,
    Label* condition_met,
    Label::Distance condition_met_distance) {
  ASSERT(cc == zero || cc == not_zero);
  if (scratch.is(object)) {
    and_(scratch, Immediate(~Page::kPageAlignmentMask));
  } else {
    movq(scratch, Immediate(~Page::kPageAlignmentMask));
    and_(scratch, object);
  }
  if (mask < (1 << kBitsPerByte)) {
    testb(Operand(scratch, MemoryChunk::kFlagsOffset),
          Immediate(static_cast<uint8_t>(mask)));
  } else {
    testl(Operand(scratch, MemoryChunk::kFlagsOffset), Immediate(mask));
  }
  j(cc, condition_met, condition_met_distance);
}


void MacroAssembler::JumpIfBlack(Register object,
                                 Register bitmap_scratch,
                                 Register mask_scratch,
                                 Label* on_black,
                                 Label::Distance on_black_distance) {
  ASSERT(!AreAliased(object, bitmap_scratch, mask_scratch, rcx));
  GetMarkBits(object, bitmap_scratch, mask_scratch);

  ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
  // The mask_scratch register contains a 1 at the position of the first bit
  // and a 0 at all other positions, including the position of the second bit.
  movq(rcx, mask_scratch);
  // Make rcx into a mask that covers both marking bits using the operation
  // rcx = mask | (mask << 1).
  lea(rcx, Operand(mask_scratch, mask_scratch, times_2, 0));
  // Note that we are using a 4-byte aligned 8-byte load.
  and_(rcx, Operand(bitmap_scratch, MemoryChunk::kHeaderSize));
  cmpq(mask_scratch, rcx);
  j(equal, on_black, on_black_distance);
}


// Detect some, but not all, common pointer-free objects.  This is used by the
// incremental write barrier which doesn't care about oddballs (they are always
// marked black immediately so this code is not hit).
void MacroAssembler::JumpIfDataObject(
    Register value,
    Register scratch,
    Label* not_data_object,
    Label::Distance not_data_object_distance) {
  Label is_data_object;
  movq(scratch, FieldOperand(value, HeapObject::kMapOffset));
  CompareRoot(scratch, Heap::kHeapNumberMapRootIndex);
  j(equal, &is_data_object, Label::kNear);
  ASSERT(kIsIndirectStringTag == 1 && kIsIndirectStringMask == 1);
  ASSERT(kNotStringTag == 0x80 && kIsNotStringMask == 0x80);
  // If it's a string and it's not a cons string then it's an object containing
  // no GC pointers.
  testb(FieldOperand(scratch, Map::kInstanceTypeOffset),
        Immediate(kIsIndirectStringMask | kIsNotStringMask));
  j(not_zero, not_data_object, not_data_object_distance);
  bind(&is_data_object);
}


void MacroAssembler::GetMarkBits(Register addr_reg,
                                 Register bitmap_reg,
                                 Register mask_reg) {
  ASSERT(!AreAliased(addr_reg, bitmap_reg, mask_reg, rcx));
  movq(bitmap_reg, addr_reg);
  // Sign extended 32 bit immediate.
  and_(bitmap_reg, Immediate(~Page::kPageAlignmentMask));
  movq(rcx, addr_reg);
  int shift =
      Bitmap::kBitsPerCellLog2 + kPointerSizeLog2 - Bitmap::kBytesPerCellLog2;
  shrl(rcx, Immediate(shift));
  and_(rcx,
       Immediate((Page::kPageAlignmentMask >> shift) &
                 ~(Bitmap::kBytesPerCell - 1)));

  addq(bitmap_reg, rcx);
  movq(rcx, addr_reg);
  shrl(rcx, Immediate(kPointerSizeLog2));
  and_(rcx, Immediate((1 << Bitmap::kBitsPerCellLog2) - 1));
  movl(mask_reg, Immediate(1));
  shl_cl(mask_reg);
}


void MacroAssembler::EnsureNotWhite(
    Register value,
    Register bitmap_scratch,
    Register mask_scratch,
    Label* value_is_white_and_not_data,
    Label::Distance distance) {
  ASSERT(!AreAliased(value, bitmap_scratch, mask_scratch, rcx));
  GetMarkBits(value, bitmap_scratch, mask_scratch);

  // If the value is black or grey we don't need to do anything.
  ASSERT(strcmp(Marking::kWhiteBitPattern, "00") == 0);
  ASSERT(strcmp(Marking::kBlackBitPattern, "10") == 0);
  ASSERT(strcmp(Marking::kGreyBitPattern, "11") == 0);
  ASSERT(strcmp(Marking::kImpossibleBitPattern, "01") == 0);

  Label done;

  // Since both black and grey have a 1 in the first position and white does
  // not have a 1 there we only need to check one bit.
  testq(Operand(bitmap_scratch, MemoryChunk::kHeaderSize), mask_scratch);
  j(not_zero, &done, Label::kNear);

  if (FLAG_debug_code) {
    // Check for impossible bit pattern.
    Label ok;
    push(mask_scratch);
    // shl.  May overflow making the check conservative.
    addq(mask_scratch, mask_scratch);
    testq(Operand(bitmap_scratch, MemoryChunk::kHeaderSize), mask_scratch);
    j(zero, &ok, Label::kNear);
    int3();
    bind(&ok);
    pop(mask_scratch);
  }

  // Value is white.  We check whether it is data that doesn't need scanning.
  // Currently only checks for HeapNumber and non-cons strings.
  Register map = rcx;  // Holds map while checking type.
  Register length = rcx;  // Holds length of object after checking type.
  Label not_heap_number;
  Label is_data_object;

  // Check for heap-number
  movq(map, FieldOperand(value, HeapObject::kMapOffset));
  CompareRoot(map, Heap::kHeapNumberMapRootIndex);
  j(not_equal, &not_heap_number, Label::kNear);
  movq(length, Immediate(HeapNumber::kSize));
  jmp(&is_data_object, Label::kNear);

  bind(&not_heap_number);
  // Check for strings.
  ASSERT(kIsIndirectStringTag == 1 && kIsIndirectStringMask == 1);
  ASSERT(kNotStringTag == 0x80 && kIsNotStringMask == 0x80);
  // If it's a string and it's not a cons string then it's an object containing
  // no GC pointers.
  Register instance_type = rcx;
  movzxbl(instance_type, FieldOperand(map, Map::kInstanceTypeOffset));
  testb(instance_type, Immediate(kIsIndirectStringMask | kIsNotStringMask));
  j(not_zero, value_is_white_and_not_data);
  // It's a non-indirect (non-cons and non-slice) string.
  // If it's external, the length is just ExternalString::kSize.
  // Otherwise it's String::kHeaderSize + string->length() * (1 or 2).
  Label not_external;
  // External strings are the only ones with the kExternalStringTag bit
  // set.
  ASSERT_EQ(0, kSeqStringTag & kExternalStringTag);
  ASSERT_EQ(0, kConsStringTag & kExternalStringTag);
  testb(instance_type, Immediate(kExternalStringTag));
  j(zero, &not_external, Label::kNear);
  movq(length, Immediate(ExternalString::kSize));
  jmp(&is_data_object, Label::kNear);

  bind(&not_external);
  // Sequential string, either ASCII or UC16.
  ASSERT(kAsciiStringTag == 0x04);
  and_(length, Immediate(kStringEncodingMask));
  xor_(length, Immediate(kStringEncodingMask));
  addq(length, Immediate(0x04));
  // Value now either 4 (if ASCII) or 8 (if UC16), i.e. char-size shifted by 2.
  imul(length, FieldOperand(value, String::kLengthOffset));
  shr(length, Immediate(2 + kSmiTagSize + kSmiShiftSize));
  addq(length, Immediate(SeqString::kHeaderSize + kObjectAlignmentMask));
  and_(length, Immediate(~kObjectAlignmentMask));

  bind(&is_data_object);
  // Value is a data object, and it is white.  Mark it black.  Since we know
  // that the object is white we can make it black by flipping one bit.
  or_(Operand(bitmap_scratch, MemoryChunk::kHeaderSize), mask_scratch);

  and_(bitmap_scratch, Immediate(~Page::kPageAlignmentMask));
  addl(Operand(bitmap_scratch, MemoryChunk::kLiveBytesOffset), length);

  bind(&done);
}


void MacroAssembler::CheckEnumCache(Register null_value, Label* call_runtime) {
  Label next;
  Register empty_fixed_array_value = r8;
  LoadRoot(empty_fixed_array_value, Heap::kEmptyFixedArrayRootIndex);
  Register empty_descriptor_array_value = r9;
  LoadRoot(empty_descriptor_array_value,
              Heap::kEmptyDescriptorArrayRootIndex);
  movq(rcx, rax);
  bind(&next);

  // Check that there are no elements.  Register rcx contains the
  // current JS object we've reached through the prototype chain.
  cmpq(empty_fixed_array_value,
       FieldOperand(rcx, JSObject::kElementsOffset));
  j(not_equal, call_runtime);

  // Check that instance descriptors are not empty so that we can
  // check for an enum cache.  Leave the map in rbx for the subsequent
  // prototype load.
  movq(rbx, FieldOperand(rcx, HeapObject::kMapOffset));
  movq(rdx, FieldOperand(rbx, Map::kInstanceDescriptorsOrBackPointerOffset));

  CheckMap(rdx,
           isolate()->factory()->fixed_array_map(),
           call_runtime,
           DONT_DO_SMI_CHECK);

  // Check that there is an enum cache in the non-empty instance
  // descriptors (rdx).  This is the case if the next enumeration
  // index field does not contain a smi.
  movq(rdx, FieldOperand(rdx, DescriptorArray::kLastAddedOffset));
  JumpIfSmi(rdx, call_runtime);

  // For all objects but the receiver, check that the cache is empty.
  Label check_prototype;
  cmpq(rcx, rax);
  j(equal, &check_prototype, Label::kNear);
  movq(rdx, FieldOperand(rdx, DescriptorArray::kEnumCacheBridgeCacheOffset));
  cmpq(rdx, empty_fixed_array_value);
  j(not_equal, call_runtime);

  // Load the prototype from the map and loop if non-null.
  bind(&check_prototype);
  movq(rcx, FieldOperand(rbx, Map::kPrototypeOffset));
  cmpq(rcx, null_value);
  j(not_equal, &next);
}


} }  // namespace v8::internal

#endif  // V8_TARGET_ARCH_X64

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