[intrinsics] Kill the %_IsMinusZero intrinsic.

By now only the default %TypedArray%.prototype.sort compare function
and the JS implementation of SameValueZero were still using the odd
%_IsMinusZero intrinsic, whose semantics both included a number check
(actually HeapNumber test) plus testing if the heap number stores the
special -0 value. In both cases we already know that we deal with
number so we can reduce it to a simple number test for -0, which can
be expressed via dividing 1 by that value and checking the sign of
the result. In case of the compare function, we can be even smarter
and work with the reciprocal values in case x and y are equal to 0
(although long term we should probably rewrite the fast case for
the typed array sorting function in C++ anyway, which will be way,
way faster than our handwritten callback-style, type-feedback
polluted JS implementation).

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/1680783002

Cr-Commit-Position: refs/heads/master@{#33833}

src/compiler/js-intrinsic-lowering.cc

@@ -69,8 +69,6 @@ Reduction JSIntrinsicLowering::Reduce(Node* node) {
       return ReduceMathSqrt(node);
     case Runtime::kInlineValueOf:
       return ReduceValueOf(node);
-    case Runtime::kInlineIsMinusZero:
-      return ReduceIsMinusZero(node);
     case Runtime::kInlineFixedArrayGet:
       return ReduceFixedArrayGet(node);
     case Runtime::kInlineFixedArraySet:
@@ -338,30 +336,6 @@ Reduction JSIntrinsicLowering::Change(Node* node, const Operator* op) {
 }
 
 
-Reduction JSIntrinsicLowering::ReduceIsMinusZero(Node* node) {
-  Node* value = NodeProperties::GetValueInput(node, 0);
-  Node* effect = NodeProperties::GetEffectInput(node);
-
-  Node* double_lo =
-      graph()->NewNode(machine()->Float64ExtractLowWord32(), value);
-  Node* check1 = graph()->NewNode(machine()->Word32Equal(), double_lo,
-                                  jsgraph()->ZeroConstant());
-
-  Node* double_hi =
-      graph()->NewNode(machine()->Float64ExtractHighWord32(), value);
-  Node* check2 = graph()->NewNode(
-      machine()->Word32Equal(), double_hi,
-      jsgraph()->Int32Constant(static_cast<int32_t>(0x80000000)));
-
-  ReplaceWithValue(node, node, effect);
-
-  Node* and_result = graph()->NewNode(machine()->Word32And(), check1, check2);
-
-  return Change(node, machine()->Word32Equal(), and_result,
-                jsgraph()->Int32Constant(1));
-}
-
-
 Reduction JSIntrinsicLowering::ReduceFixedArrayGet(Node* node) {
   Node* base = node->InputAt(0);
   Node* index = node->InputAt(1);

src/compiler/js-intrinsic-lowering.h

@@ -44,7 +44,6 @@ class JSIntrinsicLowering final : public AdvancedReducer {
   Reduction ReduceDoubleHi(Node* node);
   Reduction ReduceDoubleLo(Node* node);
   Reduction ReduceIncrementStatsCounter(Node* node);
-  Reduction ReduceIsMinusZero(Node* node);
   Reduction ReduceIsInstanceType(Node* node, InstanceType instance_type);
   Reduction ReduceIsJSReceiver(Node* node);
   Reduction ReduceIsSmi(Node* node);

src/compiler/typer.cc

@@ -1564,7 +1564,6 @@ Type* Typer::Visitor::TypeJSCallRuntime(Node* node) {
     case Runtime::kInlineIsArray:
     case Runtime::kInlineIsDate:
     case Runtime::kInlineIsTypedArray:
-    case Runtime::kInlineIsMinusZero:
     case Runtime::kInlineIsRegExp:
       return Type::Boolean();
     case Runtime::kInlineDoubleLo:

src/crankshaft/arm/lithium-arm.cc

@@ -1743,14 +1743,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegister(instr->value());
-  LOperand* scratch = TempRegister();
-  return new(zone()) LCompareMinusZeroAndBranch(value, scratch);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* value = UseRegisterAtStart(instr->value());

src/crankshaft/arm/lithium-arm.h

@@ -47,7 +47,6 @@ class LCodeGen;
   V(ClampIToUint8)                           \
   V(ClampTToUint8)                           \
   V(ClassOfTestAndBranch)                    \
-  V(CompareMinusZeroAndBranch)               \
   V(CompareNumericAndBranch)                 \
   V(CmpObjectEqAndBranch)                    \
   V(CmpHoleAndBranch)                        \
@@ -991,22 +990,6 @@ class LCmpHoleAndBranch final : public LControlInstruction<1, 0> {
 };
 
 
-class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 1> {
- public:
-  LCompareMinusZeroAndBranch(LOperand* value, LOperand* temp) {
-    inputs_[0] = value;
-    temps_[0] = temp;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-  LOperand* temp() { return temps_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch,
-                               "cmp-minus-zero-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(CompareMinusZeroAndBranch)
-};
-
-
 class LIsStringAndBranch final : public LControlInstruction<1, 1> {
  public:
   LIsStringAndBranch(LOperand* value, LOperand* temp) {

src/crankshaft/arm/lithium-codegen-arm.cc

@@ -2313,33 +2313,6 @@ void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
 }
 
 
-void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
-  Representation rep = instr->hydrogen()->value()->representation();
-  DCHECK(!rep.IsInteger32());
-  Register scratch = ToRegister(instr->temp());
-
-  if (rep.IsDouble()) {
-    DwVfpRegister value = ToDoubleRegister(instr->value());
-    __ VFPCompareAndSetFlags(value, 0.0);
-    EmitFalseBranch(instr, ne);
-    __ VmovHigh(scratch, value);
-    __ cmp(scratch, Operand(0x80000000));
-  } else {
-    Register value = ToRegister(instr->value());
-    __ CheckMap(value,
-                scratch,
-                Heap::kHeapNumberMapRootIndex,
-                instr->FalseLabel(chunk()),
-                DO_SMI_CHECK);
-    __ ldr(scratch, FieldMemOperand(value, HeapNumber::kExponentOffset));
-    __ ldr(ip, FieldMemOperand(value, HeapNumber::kMantissaOffset));
-    __ cmp(scratch, Operand(0x80000000));
-    __ cmp(ip, Operand(0x00000000), eq);
-  }
-  EmitBranch(instr, eq);
-}
-
-
 Condition LCodeGen::EmitIsString(Register input,
                                  Register temp1,
                                  Label* is_not_string,

src/crankshaft/arm64/lithium-arm64.cc

@@ -1567,14 +1567,6 @@ LInstruction* LChunkBuilder::DoInvokeFunction(HInvokeFunction* instr) {
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegister(instr->value());
-  LOperand* scratch = TempRegister();
-  return new(zone()) LCompareMinusZeroAndBranch(value, scratch);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* value = UseRegisterAtStart(instr->value());

src/crankshaft/arm64/lithium-arm64.h

@@ -55,7 +55,6 @@ class LCodeGen;
   V(CmpMapAndBranch)                         \
   V(CmpObjectEqAndBranch)                    \
   V(CmpT)                                    \
-  V(CompareMinusZeroAndBranch)               \
   V(CompareNumericAndBranch)                 \
   V(ConstantD)                               \
   V(ConstantE)                               \
@@ -1146,22 +1145,6 @@ class LCmpT final : public LTemplateInstruction<1, 3, 0> {
 };
 
 
-class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 1> {
- public:
-  LCompareMinusZeroAndBranch(LOperand* value, LOperand* temp) {
-    inputs_[0] = value;
-    temps_[0] = temp;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-  LOperand* temp() { return temps_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch,
-                               "cmp-minus-zero-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(CompareMinusZeroAndBranch)
-};
-
-
 class LCompareNumericAndBranch final : public LControlInstruction<2, 0> {
  public:
   LCompareNumericAndBranch(LOperand* left, LOperand* right) {

src/crankshaft/arm64/lithium-codegen-arm64.cc

@@ -2327,24 +2327,6 @@ void LCodeGen::DoCmpMapAndBranch(LCmpMapAndBranch* instr) {
 }
 
 
-void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
-  Representation rep = instr->hydrogen()->value()->representation();
-  DCHECK(!rep.IsInteger32());
-  Register scratch = ToRegister(instr->temp());
-
-  if (rep.IsDouble()) {
-    __ JumpIfMinusZero(ToDoubleRegister(instr->value()),
-                       instr->TrueLabel(chunk()));
-  } else {
-    Register value = ToRegister(instr->value());
-    __ JumpIfNotHeapNumber(value, instr->FalseLabel(chunk()), DO_SMI_CHECK);
-    __ Ldr(scratch, FieldMemOperand(value, HeapNumber::kValueOffset));
-    __ JumpIfMinusZero(scratch, instr->TrueLabel(chunk()));
-  }
-  EmitGoto(instr->FalseDestination(chunk()));
-}
-
-
 void LCodeGen::DoCompareNumericAndBranch(LCompareNumericAndBranch* instr) {
   LOperand* left = instr->left();
   LOperand* right = instr->right();

src/crankshaft/hydrogen-instructions.cc

@@ -783,7 +783,6 @@ bool HInstruction::CanDeoptimize() {
     case HValue::kCompareGeneric:
     case HValue::kCompareHoleAndBranch:
     case HValue::kCompareMap:
-    case HValue::kCompareMinusZeroAndBranch:
     case HValue::kCompareNumericAndBranch:
     case HValue::kCompareObjectEqAndBranch:
     case HValue::kConstant:
@@ -3326,31 +3325,6 @@ bool HCompareNumericAndBranch::KnownSuccessorBlock(HBasicBlock** block) {
 }
 
 
-bool HCompareMinusZeroAndBranch::KnownSuccessorBlock(HBasicBlock** block) {
-  if (FLAG_fold_constants && value()->IsConstant()) {
-    HConstant* constant = HConstant::cast(value());
-    if (constant->HasDoubleValue()) {
-      *block = IsMinusZero(constant->DoubleValue())
-          ? FirstSuccessor() : SecondSuccessor();
-      return true;
-    }
-  }
-  if (value()->representation().IsSmiOrInteger32()) {
-    // A Smi or Integer32 cannot contain minus zero.
-    *block = SecondSuccessor();
-    return true;
-  }
-  *block = NULL;
-  return false;
-}
-
-
-void HCompareMinusZeroAndBranch::InferRepresentation(
-    HInferRepresentationPhase* h_infer) {
-  ChangeRepresentation(value()->representation());
-}
-
-
 std::ostream& HGoto::PrintDataTo(std::ostream& os) const {  // NOLINT
   return os << *SuccessorAt(0);
 }

src/crankshaft/hydrogen-instructions.h

@@ -79,7 +79,6 @@ class LChunkBuilder;
   V(CompareNumericAndBranch)                  \
   V(CompareHoleAndBranch)                     \
   V(CompareGeneric)                           \
-  V(CompareMinusZeroAndBranch)                \
   V(CompareObjectEqAndBranch)                 \
   V(CompareMap)                               \
   V(Constant)                                 \
@@ -4345,27 +4344,6 @@ class HCompareHoleAndBranch final : public HUnaryControlInstruction {
 };
 
 
-class HCompareMinusZeroAndBranch final : public HUnaryControlInstruction {
- public:
-  DECLARE_INSTRUCTION_FACTORY_P1(HCompareMinusZeroAndBranch, HValue*);
-
-  void InferRepresentation(HInferRepresentationPhase* h_infer) override;
-
-  Representation RequiredInputRepresentation(int index) override {
-    return representation();
-  }
-
-  bool KnownSuccessorBlock(HBasicBlock** block) override;
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch)
-
- private:
-  explicit HCompareMinusZeroAndBranch(HValue* value)
-      : HUnaryControlInstruction(value, NULL, NULL) {
-  }
-};
-
-
 class HCompareObjectEqAndBranch : public HTemplateControlInstruction<2, 2> {
  public:
   DECLARE_INSTRUCTION_FACTORY_P2(HCompareObjectEqAndBranch, HValue*, HValue*);

src/crankshaft/hydrogen-range-analysis.cc

@@ -71,12 +71,6 @@ void HRangeAnalysisPhase::Run() {
                 instr->to().IsSmiOrInteger32());
           PropagateMinusZeroChecks(instr->value());
         }
-      } else if (value->IsCompareMinusZeroAndBranch()) {
-        HCompareMinusZeroAndBranch* instr =
-            HCompareMinusZeroAndBranch::cast(value);
-        if (instr->value()->representation().IsSmiOrInteger32()) {
-          PropagateMinusZeroChecks(instr->value());
-        }
       }
     }
 

src/crankshaft/hydrogen.cc

@@ -12232,15 +12232,6 @@ void HOptimizedGraphBuilder::GenerateIsJSReceiver(CallRuntime* call) {
 }
 
 
-void HOptimizedGraphBuilder::GenerateIsMinusZero(CallRuntime* call) {
-  DCHECK(call->arguments()->length() == 1);
-  CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
-  HValue* value = Pop();
-  HCompareMinusZeroAndBranch* result = New<HCompareMinusZeroAndBranch>(value);
-  return ast_context()->ReturnControl(result, call->id());
-}
-
-
 void HOptimizedGraphBuilder::GenerateHasCachedArrayIndex(CallRuntime* call) {
   DCHECK(call->arguments()->length() == 1);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));

src/crankshaft/hydrogen.h

@@ -2225,7 +2225,6 @@ class HOptimizedGraphBuilder : public HGraphBuilder, public AstVisitor {
   F(ToNumber)                          \
   F(IsJSReceiver)                      \
   F(MathPow)                           \
-  F(IsMinusZero)                       \
   F(HasCachedArrayIndex)               \
   F(GetCachedArrayIndex)               \
   F(FastOneByteArrayJoin)              \

src/crankshaft/ia32/lithium-codegen-ia32.cc

@@ -2217,34 +2217,6 @@ void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
 }
 
 
-void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
-  Representation rep = instr->hydrogen()->value()->representation();
-  DCHECK(!rep.IsInteger32());
-  Register scratch = ToRegister(instr->temp());
-
-  if (rep.IsDouble()) {
-    XMMRegister value = ToDoubleRegister(instr->value());
-    XMMRegister xmm_scratch = double_scratch0();
-    __ xorps(xmm_scratch, xmm_scratch);
-    __ ucomisd(xmm_scratch, value);
-    EmitFalseBranch(instr, not_equal);
-    __ movmskpd(scratch, value);
-    __ test(scratch, Immediate(1));
-    EmitBranch(instr, not_zero);
-  } else {
-    Register value = ToRegister(instr->value());
-    Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
-    __ CheckMap(value, map, instr->FalseLabel(chunk()), DO_SMI_CHECK);
-    __ cmp(FieldOperand(value, HeapNumber::kExponentOffset),
-           Immediate(0x1));
-    EmitFalseBranch(instr, no_overflow);
-    __ cmp(FieldOperand(value, HeapNumber::kMantissaOffset),
-           Immediate(0x00000000));
-    EmitBranch(instr, equal);
-  }
-}
-
-
 Condition LCodeGen::EmitIsString(Register input,
                                  Register temp1,
                                  Label* is_not_string,

src/crankshaft/ia32/lithium-ia32.cc

@@ -1709,14 +1709,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegister(instr->value());
-  LOperand* scratch = TempRegister();
-  return new(zone()) LCompareMinusZeroAndBranch(value, scratch);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* temp = TempRegister();

src/crankshaft/ia32/lithium-ia32.h

@@ -51,7 +51,6 @@ class LCodeGen;
   V(ClampIToUint8)                           \
   V(ClampTToUint8)                           \
   V(ClassOfTestAndBranch)                    \
-  V(CompareMinusZeroAndBranch)               \
   V(CompareNumericAndBranch)                 \
   V(CmpObjectEqAndBranch)                    \
   V(CmpHoleAndBranch)                        \
@@ -974,22 +973,6 @@ class LCmpHoleAndBranch final : public LControlInstruction<1, 0> {
 };
 
 
-class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 1> {
- public:
-  LCompareMinusZeroAndBranch(LOperand* value, LOperand* temp) {
-    inputs_[0] = value;
-    temps_[0] = temp;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-  LOperand* temp() { return temps_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch,
-                               "cmp-minus-zero-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(CompareMinusZeroAndBranch)
-};
-
-
 class LIsStringAndBranch final : public LControlInstruction<1, 1> {
  public:
   LIsStringAndBranch(LOperand* value, LOperand* temp) {

src/crankshaft/mips/lithium-codegen-mips.cc

@@ -2221,32 +2221,6 @@ void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
 }
 
 
-void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
-  Representation rep = instr->hydrogen()->value()->representation();
-  DCHECK(!rep.IsInteger32());
-  Register scratch = ToRegister(instr->temp());
-
-  if (rep.IsDouble()) {
-    DoubleRegister value = ToDoubleRegister(instr->value());
-    EmitFalseBranchF(instr, ne, value, kDoubleRegZero);
-    __ FmoveHigh(scratch, value);
-    __ li(at, 0x80000000);
-  } else {
-    Register value = ToRegister(instr->value());
-    __ CheckMap(value,
-                scratch,
-                Heap::kHeapNumberMapRootIndex,
-                instr->FalseLabel(chunk()),
-                DO_SMI_CHECK);
-    __ lw(scratch, FieldMemOperand(value, HeapNumber::kExponentOffset));
-    EmitFalseBranch(instr, ne, scratch, Operand(0x80000000));
-    __ lw(scratch, FieldMemOperand(value, HeapNumber::kMantissaOffset));
-    __ mov(at, zero_reg);
-  }
-  EmitBranch(instr, eq, scratch, Operand(at));
-}
-
-
 Condition LCodeGen::EmitIsString(Register input,
                                  Register temp1,
                                  Label* is_not_string,

src/crankshaft/mips/lithium-mips.cc

@@ -1690,14 +1690,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegister(instr->value());
-  LOperand* scratch = TempRegister();
-  return new(zone()) LCompareMinusZeroAndBranch(value, scratch);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* temp = TempRegister();

src/crankshaft/mips/lithium-mips.h

@@ -47,7 +47,6 @@ class LCodeGen;
   V(ClampIToUint8)                           \
   V(ClampTToUint8)                           \
   V(ClassOfTestAndBranch)                    \
-  V(CompareMinusZeroAndBranch)               \
   V(CompareNumericAndBranch)                 \
   V(CmpObjectEqAndBranch)                    \
   V(CmpHoleAndBranch)                        \
@@ -969,22 +968,6 @@ class LCmpHoleAndBranch final : public LControlInstruction<1, 0> {
 };
 
 
-class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 1> {
- public:
-  LCompareMinusZeroAndBranch(LOperand* value, LOperand* temp) {
-    inputs_[0] = value;
-    temps_[0] = temp;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-  LOperand* temp() { return temps_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch,
-                               "cmp-minus-zero-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(CompareMinusZeroAndBranch)
-};
-
-
 class LIsStringAndBranch final : public LControlInstruction<1, 1> {
  public:
   LIsStringAndBranch(LOperand* value, LOperand* temp) {

src/crankshaft/mips64/lithium-codegen-mips64.cc

@@ -2338,35 +2338,6 @@ void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
 }
 
 
-void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
-  Representation rep = instr->hydrogen()->value()->representation();
-  DCHECK(!rep.IsInteger32());
-  Register scratch = ToRegister(instr->temp());
-
-  if (rep.IsDouble()) {
-    DoubleRegister value = ToDoubleRegister(instr->value());
-    EmitFalseBranchF(instr, ne, value, kDoubleRegZero);
-    __ FmoveHigh(scratch, value);
-    // Only use low 32-bits of value.
-    __ dsll32(scratch, scratch, 0);
-    __ dsrl32(scratch, scratch, 0);
-    __ li(at, 0x80000000);
-  } else {
-    Register value = ToRegister(instr->value());
-    __ CheckMap(value,
-                scratch,
-                Heap::kHeapNumberMapRootIndex,
-                instr->FalseLabel(chunk()),
-                DO_SMI_CHECK);
-    __ lwu(scratch, FieldMemOperand(value, HeapNumber::kExponentOffset));
-    EmitFalseBranch(instr, ne, scratch, Operand(0x80000000));
-    __ lwu(scratch, FieldMemOperand(value, HeapNumber::kMantissaOffset));
-    __ mov(at, zero_reg);
-  }
-  EmitBranch(instr, eq, scratch, Operand(at));
-}
-
-
 Condition LCodeGen::EmitIsString(Register input,
                                  Register temp1,
                                  Label* is_not_string,

src/crankshaft/mips64/lithium-mips64.cc

@@ -1696,14 +1696,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegister(instr->value());
-  LOperand* scratch = TempRegister();
-  return new(zone()) LCompareMinusZeroAndBranch(value, scratch);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* temp = TempRegister();

src/crankshaft/mips64/lithium-mips64.h

@@ -49,7 +49,6 @@ class LCodeGen;
   V(ClampIToUint8)                           \
   V(ClampTToUint8)                           \
   V(ClassOfTestAndBranch)                    \
-  V(CompareMinusZeroAndBranch)               \
   V(CompareNumericAndBranch)                 \
   V(CmpObjectEqAndBranch)                    \
   V(CmpHoleAndBranch)                        \
@@ -987,22 +986,6 @@ class LCmpHoleAndBranch final : public LControlInstruction<1, 0> {
 };
 
 
-class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 1> {
- public:
-  LCompareMinusZeroAndBranch(LOperand* value, LOperand* temp) {
-    inputs_[0] = value;
-    temps_[0] = temp;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-  LOperand* temp() { return temps_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch,
-                               "cmp-minus-zero-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(CompareMinusZeroAndBranch)
-};
-
-
 class LIsStringAndBranch final : public LControlInstruction<1, 1> {
  public:
   LIsStringAndBranch(LOperand* value, LOperand* temp) {

src/crankshaft/ppc/lithium-codegen-ppc.cc

@@ -2374,27 +2374,6 @@ void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
 }
 
 
-void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
-  Representation rep = instr->hydrogen()->value()->representation();
-  DCHECK(!rep.IsInteger32());
-  Register scratch = ToRegister(instr->temp());
-
-  if (rep.IsDouble()) {
-    DoubleRegister value = ToDoubleRegister(instr->value());
-    __ fcmpu(value, kDoubleRegZero);
-    EmitFalseBranch(instr, ne);
-    __ TestDoubleSign(value, scratch);
-    EmitBranch(instr, lt);
-  } else {
-    Register value = ToRegister(instr->value());
-    __ CheckMap(value, scratch, Heap::kHeapNumberMapRootIndex,
-                instr->FalseLabel(chunk()), DO_SMI_CHECK);
-    __ TestHeapNumberIsMinusZero(value, scratch, ip);
-    EmitBranch(instr, eq);
-  }
-}
-
-
 Condition LCodeGen::EmitIsString(Register input, Register temp1,
                                  Label* is_not_string,
                                  SmiCheck check_needed = INLINE_SMI_CHECK) {

src/crankshaft/ppc/lithium-ppc.cc

@@ -1706,14 +1706,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegister(instr->value());
-  LOperand* scratch = TempRegister();
-  return new (zone()) LCompareMinusZeroAndBranch(value, scratch);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* value = UseRegisterAtStart(instr->value());

src/crankshaft/ppc/lithium-ppc.h

@@ -47,7 +47,6 @@ class LCodeGen;
   V(ClampIToUint8)                           \
   V(ClampTToUint8)                           \
   V(ClassOfTestAndBranch)                    \
-  V(CompareMinusZeroAndBranch)               \
   V(CompareNumericAndBranch)                 \
   V(CmpObjectEqAndBranch)                    \
   V(CmpHoleAndBranch)                        \
@@ -953,22 +952,6 @@ class LCmpHoleAndBranch final : public LControlInstruction<1, 0> {
 };
 
 
-class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 1> {
- public:
-  LCompareMinusZeroAndBranch(LOperand* value, LOperand* temp) {
-    inputs_[0] = value;
-    temps_[0] = temp;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-  LOperand* temp() { return temps_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch,
-                               "cmp-minus-zero-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(CompareMinusZeroAndBranch)
-};
-
-
 class LIsStringAndBranch final : public LControlInstruction<1, 1> {
  public:
   LIsStringAndBranch(LOperand* value, LOperand* temp) {

src/crankshaft/x64/lithium-codegen-x64.cc

@@ -2283,33 +2283,6 @@ void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
 }
 
 
-void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
-  Representation rep = instr->hydrogen()->value()->representation();
-  DCHECK(!rep.IsInteger32());
-
-  if (rep.IsDouble()) {
-    XMMRegister value = ToDoubleRegister(instr->value());
-    XMMRegister xmm_scratch = double_scratch0();
-    __ Xorpd(xmm_scratch, xmm_scratch);
-    __ Ucomisd(xmm_scratch, value);
-    EmitFalseBranch(instr, not_equal);
-    __ Movmskpd(kScratchRegister, value);
-    __ testl(kScratchRegister, Immediate(1));
-    EmitBranch(instr, not_zero);
-  } else {
-    Register value = ToRegister(instr->value());
-    Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
-    __ CheckMap(value, map, instr->FalseLabel(chunk()), DO_SMI_CHECK);
-    __ cmpl(FieldOperand(value, HeapNumber::kExponentOffset),
-            Immediate(0x1));
-    EmitFalseBranch(instr, no_overflow);
-    __ cmpl(FieldOperand(value, HeapNumber::kMantissaOffset),
-            Immediate(0x00000000));
-    EmitBranch(instr, equal);
-  }
-}
-
-
 Condition LCodeGen::EmitIsString(Register input,
                                  Register temp1,
                                  Label* is_not_string,

src/crankshaft/x64/lithium-x64.cc

@@ -1702,13 +1702,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegister(instr->value());
-  return new(zone()) LCompareMinusZeroAndBranch(value);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* value = UseRegisterAtStart(instr->value());

src/crankshaft/x64/lithium-x64.h

@@ -47,7 +47,6 @@ class LCodeGen;
   V(ClampIToUint8)                           \
   V(ClampTToUint8)                           \
   V(ClassOfTestAndBranch)                    \
-  V(CompareMinusZeroAndBranch)               \
   V(CompareNumericAndBranch)                 \
   V(CmpObjectEqAndBranch)                    \
   V(CmpHoleAndBranch)                        \
@@ -967,20 +966,6 @@ class LCmpHoleAndBranch final : public LControlInstruction<1, 0> {
 };
 
 
-class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 0> {
- public:
-  explicit LCompareMinusZeroAndBranch(LOperand* value) {
-    inputs_[0] = value;
-  }
-
-  LOperand* value() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch,
-                               "cmp-minus-zero-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(CompareMinusZeroAndBranch)
-};
-
-
 class LIsStringAndBranch final : public LControlInstruction<1, 1> {
  public:
   explicit LIsStringAndBranch(LOperand* value, LOperand* temp) {

src/crankshaft/x87/lithium-codegen-x87.cc

@@ -2505,29 +2505,6 @@ void LCodeGen::DoCmpHoleAndBranch(LCmpHoleAndBranch* instr) {
 }
 
 
-void LCodeGen::DoCompareMinusZeroAndBranch(LCompareMinusZeroAndBranch* instr) {
-  Representation rep = instr->hydrogen()->value()->representation();
-  DCHECK(!rep.IsInteger32());
-
-  if (rep.IsDouble()) {
-    X87Register input = ToX87Register(instr->value());
-    X87LoadForUsage(input);
-    __ FXamMinusZero();
-    EmitBranch(instr, equal);
-  } else {
-    Register value = ToRegister(instr->value());
-    Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
-    __ CheckMap(value, map, instr->FalseLabel(chunk()), DO_SMI_CHECK);
-    __ cmp(FieldOperand(value, HeapNumber::kExponentOffset),
-           Immediate(0x1));
-    EmitFalseBranch(instr, no_overflow);
-    __ cmp(FieldOperand(value, HeapNumber::kMantissaOffset),
-           Immediate(0x00000000));
-    EmitBranch(instr, equal);
-  }
-}
-
-
 Condition LCodeGen::EmitIsString(Register input,
                                  Register temp1,
                                  Label* is_not_string,

src/crankshaft/x87/lithium-x87.cc

@@ -1715,13 +1715,6 @@ LInstruction* LChunkBuilder::DoCompareHoleAndBranch(
 }
 
 
-LInstruction* LChunkBuilder::DoCompareMinusZeroAndBranch(
-    HCompareMinusZeroAndBranch* instr) {
-  LOperand* value = UseRegisterAtStart(instr->value());
-  return new (zone()) LCompareMinusZeroAndBranch(value);
-}
-
-
 LInstruction* LChunkBuilder::DoIsStringAndBranch(HIsStringAndBranch* instr) {
   DCHECK(instr->value()->representation().IsTagged());
   LOperand* temp = TempRegister();

src/crankshaft/x87/lithium-x87.h

@@ -52,7 +52,6 @@ class LCodeGen;
   V(ClampTToUint8NoSSE2)                     \
   V(ClassOfTestAndBranch)                    \
   V(ClobberDoubles)                          \
-  V(CompareMinusZeroAndBranch)               \
   V(CompareNumericAndBranch)                 \
   V(CmpObjectEqAndBranch)                    \
   V(CmpHoleAndBranch)                        \
@@ -990,18 +989,6 @@ class LCmpHoleAndBranch final : public LControlInstruction<1, 0> {
 };
 
 
-class LCompareMinusZeroAndBranch final : public LControlInstruction<1, 0> {
- public:
-  explicit LCompareMinusZeroAndBranch(LOperand* value) { inputs_[0] = value; }
-
-  LOperand* value() { return inputs_[0]; }
-
-  DECLARE_CONCRETE_INSTRUCTION(CompareMinusZeroAndBranch,
-                               "cmp-minus-zero-and-branch")
-  DECLARE_HYDROGEN_ACCESSOR(CompareMinusZeroAndBranch)
-};
-
-
 class LIsStringAndBranch final : public LControlInstruction<1, 1> {
  public:
   LIsStringAndBranch(LOperand* value, LOperand* temp) {

src/full-codegen/arm/full-codegen-arm.cc

@@ -3024,32 +3024,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  __ CheckMap(r0, r1, Heap::kHeapNumberMapRootIndex, if_false, DO_SMI_CHECK);
-  __ ldr(r2, FieldMemOperand(r0, HeapNumber::kExponentOffset));
-  __ ldr(r1, FieldMemOperand(r0, HeapNumber::kMantissaOffset));
-  __ cmp(r2, Operand(0x80000000));
-  __ cmp(r1, Operand(0x00000000), eq);
-
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(eq, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);

src/full-codegen/arm64/full-codegen-arm64.cc

@@ -2833,33 +2833,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  // Only a HeapNumber can be -0.0, so return false if we have something else.
-  __ JumpIfNotHeapNumber(x0, if_false, DO_SMI_CHECK);
-
-  // Test the bit pattern.
-  __ Ldr(x10, FieldMemOperand(x0, HeapNumber::kValueOffset));
-  __ Cmp(x10, 1);   // Set V on 0x8000000000000000.
-
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(vs, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);

src/full-codegen/full-codegen.h

@@ -535,7 +535,6 @@ class FullCodeGenerator: public AstVisitor {
   F(IsJSReceiver)                       \
   F(IsSimdValue)                        \
   F(MathPow)                            \
-  F(IsMinusZero)                        \
   F(HasCachedArrayIndex)                \
   F(GetCachedArrayIndex)                \
   F(GetSuperConstructor)                \

src/full-codegen/ia32/full-codegen-ia32.cc

@@ -2903,33 +2903,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
-  __ CheckMap(eax, map, if_false, DO_SMI_CHECK);
-  // Check if the exponent half is 0x80000000. Comparing against 1 and
-  // checking for overflow is the shortest possible encoding.
-  __ cmp(FieldOperand(eax, HeapNumber::kExponentOffset), Immediate(0x1));
-  __ j(no_overflow, if_false);
-  __ cmp(FieldOperand(eax, HeapNumber::kMantissaOffset), Immediate(0x0));
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(equal, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);

src/full-codegen/mips/full-codegen-mips.cc

@@ -3010,36 +3010,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  __ CheckMap(v0, a1, Heap::kHeapNumberMapRootIndex, if_false, DO_SMI_CHECK);
-  __ lw(a2, FieldMemOperand(v0, HeapNumber::kExponentOffset));
-  __ lw(a1, FieldMemOperand(v0, HeapNumber::kMantissaOffset));
-  __ li(t0, 0x80000000);
-  Label not_nan;
-  __ Branch(&not_nan, ne, a2, Operand(t0));
-  __ mov(t0, zero_reg);
-  __ mov(a2, a1);
-  __ bind(&not_nan);
-
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(eq, a2, Operand(t0), if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);

src/full-codegen/mips64/full-codegen-mips64.cc

@@ -3020,36 +3020,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  __ CheckMap(v0, a1, Heap::kHeapNumberMapRootIndex, if_false, DO_SMI_CHECK);
-  __ lwu(a2, FieldMemOperand(v0, HeapNumber::kExponentOffset));
-  __ lwu(a1, FieldMemOperand(v0, HeapNumber::kMantissaOffset));
-  __ li(a4, 0x80000000);
-  Label not_nan;
-  __ Branch(&not_nan, ne, a2, Operand(a4));
-  __ mov(a4, zero_reg);
-  __ mov(a2, a1);
-  __ bind(&not_nan);
-
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(eq, a2, Operand(a4), if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);

src/full-codegen/ppc/full-codegen-ppc.cc

@@ -3011,28 +3011,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false, &if_true,
-                         &if_false, &fall_through);
-
-  __ CheckMap(r3, r4, Heap::kHeapNumberMapRootIndex, if_false, DO_SMI_CHECK);
-  __ TestHeapNumberIsMinusZero(r3, r4, r5);
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(eq, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);

src/full-codegen/x64/full-codegen-x64.cc

@@ -2889,33 +2889,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
-  __ CheckMap(rax, map, if_false, DO_SMI_CHECK);
-  __ cmpl(FieldOperand(rax, HeapNumber::kExponentOffset),
-          Immediate(0x1));
-  __ j(no_overflow, if_false);
-  __ cmpl(FieldOperand(rax, HeapNumber::kMantissaOffset),
-          Immediate(0x00000000));
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(equal, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);

src/full-codegen/x87/full-codegen-x87.cc

@@ -2903,33 +2903,6 @@ void FullCodeGenerator::EmitIsSimdValue(CallRuntime* expr) {
 }
 
 
-void FullCodeGenerator::EmitIsMinusZero(CallRuntime* expr) {
-  ZoneList<Expression*>* args = expr->arguments();
-  DCHECK(args->length() == 1);
-
-  VisitForAccumulatorValue(args->at(0));
-
-  Label materialize_true, materialize_false;
-  Label* if_true = NULL;
-  Label* if_false = NULL;
-  Label* fall_through = NULL;
-  context()->PrepareTest(&materialize_true, &materialize_false,
-                         &if_true, &if_false, &fall_through);
-
-  Handle<Map> map = masm()->isolate()->factory()->heap_number_map();
-  __ CheckMap(eax, map, if_false, DO_SMI_CHECK);
-  // Check if the exponent half is 0x80000000. Comparing against 1 and
-  // checking for overflow is the shortest possible encoding.
-  __ cmp(FieldOperand(eax, HeapNumber::kExponentOffset), Immediate(0x1));
-  __ j(no_overflow, if_false);
-  __ cmp(FieldOperand(eax, HeapNumber::kMantissaOffset), Immediate(0x0));
-  PrepareForBailoutBeforeSplit(expr, true, if_true, if_false);
-  Split(equal, if_true, if_false, fall_through);
-
-  context()->Plug(if_true, if_false);
-}
-
-
 void FullCodeGenerator::EmitIsArray(CallRuntime* expr) {
   ZoneList<Expression*>* args = expr->arguments();
   DCHECK(args->length() == 1);

src/js/runtime.js

@@ -43,11 +43,11 @@ utils.ImportFromExperimental(function(from) {
 
 // ES5, section 9.12
 function SameValue(x, y) {
-  if (typeof x != typeof y) return false;
+  if (typeof x !== typeof y) return false;
   if (IS_NUMBER(x)) {
     if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true;
     // x is +0 and y is -0 or vice versa.
-    if (x === 0 && y === 0 && %_IsMinusZero(x) != %_IsMinusZero(y)) {
+    if (x === 0 && y === 0 && 1/x !== 1/y) {
       return false;
     }
   }
@@ -58,7 +58,7 @@ function SameValue(x, y) {
 
 // ES6, section 7.2.4
 function SameValueZero(x, y) {
-  if (typeof x != typeof y) return false;
+  if (typeof x !== typeof y) return false;
   if (IS_NUMBER(x)) {
     if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true;
   }

src/js/typedarray.js

@@ -567,22 +567,20 @@ function TypedArrayReverse() {
 
 
 function TypedArrayComparefn(x, y) {
-  if (IsNaN(x) && IsNaN(y)) {
+  if (x === 0 && x === y) {
-    return IsNaN(y) ? 0 : 1;
+    x = 1 / x;
+    y = 1 / y;
   }
-  if (IsNaN(x)) {
+  if (x < y) {
+    return -1;
+  } else if (x > y) {
+    return 1;
+  } else if (IsNaN(x) && IsNaN(y)) {
+    return IsNaN(y) ? 0 : 1;
+  } else if (IsNaN(x)) {
     return 1;
   }
-  if (x === 0 && x === y) {
+  return 0;
-    if (%_IsMinusZero(x)) {
-      if (!%_IsMinusZero(y)) {
-        return -1;
-      }
-    } else if (%_IsMinusZero(y)) {
-      return 1;
-    }
-  }
-  return x - y;
 }
 
 

src/ppc/macro-assembler-ppc.cc

@@ -2207,25 +2207,6 @@ void MacroAssembler::TestDoubleIsMinusZero(DoubleRegister input,
 #endif
 }
 
-void MacroAssembler::TestHeapNumberIsMinusZero(Register input,
-                                               Register scratch1,
-                                               Register scratch2) {
-#if V8_TARGET_ARCH_PPC64
-  LoadP(scratch1, FieldMemOperand(input, HeapNumber::kValueOffset));
-  rotldi(scratch1, scratch1, 1);
-  cmpi(scratch1, Operand(1));
-#else
-  lwz(scratch1, FieldMemOperand(input, HeapNumber::kExponentOffset));
-  lwz(scratch2, FieldMemOperand(input, HeapNumber::kMantissaOffset));
-  Label done;
-  cmpi(scratch2, Operand::Zero());
-  bne(&done);
-  lis(scratch2, Operand(SIGN_EXT_IMM16(0x8000)));
-  cmp(scratch1, scratch2);
-  bind(&done);
-#endif
-}
-
 void MacroAssembler::TestDoubleSign(DoubleRegister input, Register scratch) {
 #if V8_TARGET_ARCH_PPC64
   MovDoubleToInt64(scratch, input);

src/ppc/macro-assembler-ppc.h

@@ -876,8 +876,6 @@ class MacroAssembler : public Assembler {
   // CR_EQ in cr7 holds the result.
   void TestDoubleIsMinusZero(DoubleRegister input, Register scratch1,
                              Register scratch2);
-  void TestHeapNumberIsMinusZero(Register input, Register scratch1,
-                                 Register scratch2);
 
   // Check the sign of a double.
   // CR_LT in cr7 holds the result.

src/runtime/runtime-maths.cc

@@ -238,16 +238,6 @@ RUNTIME_FUNCTION(Runtime_MathFround) {
 }
 
 
-RUNTIME_FUNCTION(Runtime_IsMinusZero) {
-  SealHandleScope shs(isolate);
-  DCHECK(args.length() == 1);
-  CONVERT_ARG_CHECKED(Object, obj, 0);
-  if (!obj->IsHeapNumber()) return isolate->heap()->false_value();
-  HeapNumber* number = HeapNumber::cast(obj);
-  return isolate->heap()->ToBoolean(IsMinusZero(number->value()));
-}
-
-
 RUNTIME_FUNCTION(Runtime_GenerateRandomNumbers) {
   HandleScope scope(isolate);
   DCHECK(args.length() == 1);

src/runtime/runtime.h

@@ -388,7 +388,6 @@ namespace internal {
   F(RoundNumber, 1, 1)              \
   F(MathSqrt, 1, 1)                 \
   F(MathFround, 1, 1)               \
-  F(IsMinusZero, 1, 1)              \
   F(GenerateRandomNumbers, 1, 1)
 
 

test/cctest/compiler/test-run-intrinsics.cc

@@ -104,18 +104,6 @@ TEST(IsFunction) {
 }
 
 
-TEST(IsMinusZero) {
-  FunctionTester T("(function(a) { return %_IsMinusZero(a); })", flags);
-
-  T.CheckFalse(T.Val(1));
-  T.CheckFalse(T.Val(1.1));
-  T.CheckTrue(T.Val(-0.0));
-  T.CheckFalse(T.Val(-2));
-  T.CheckFalse(T.Val(-2.3));
-  T.CheckFalse(T.undefined());
-}
-
-
 TEST(IsRegExp) {
   FunctionTester T("(function(a) { return %_IsRegExp(a); })", flags);
 

test/mjsunit/compiler/minus-zero.js

@@ -37,31 +37,8 @@ assertEquals(0, add(0, 0));
 assertEquals(-0, add(-0, -0));
 
 
-function test(x, y) {
-  assertTrue(%_IsMinusZero(-0));
-  assertTrue(%_IsMinusZero(1/(-Infinity)));
-  assertTrue(%_IsMinusZero(x));
-
-  assertFalse(%_IsMinusZero(0));
-  assertFalse(%_IsMinusZero(1/Infinity));
-  assertFalse(%_IsMinusZero(0.1));
-  assertFalse(%_IsMinusZero(-0.2));
-  assertFalse(%_IsMinusZero({}));
-  assertFalse(%_IsMinusZero(""));
-  assertFalse(%_IsMinusZero("-0"));
-  assertFalse(%_IsMinusZero(function() {}));
-  assertFalse(%_IsMinusZero(y));
-}
-
-test(-0, 1.2);
-test(-0, 1.2);
-%OptimizeFunctionOnNextCall(test);
-test(-0, 1.2);
-assertOptimized(test);
-
-
 function testsin() {
-  assertTrue(%_IsMinusZero(Math.sin(-0)));
+  assertEquals(-0, Math.sin(-0));
 }
 
 testsin();
@@ -71,8 +48,7 @@ testsin();
 
 
 function testfloor() {
-  assertTrue(%_IsMinusZero(Math.floor(-0)));
+  assertEquals(-0, Math.floor(-0));
-  assertFalse(%_IsMinusZero(Math.floor(2)));
 }
 
 testfloor();

test/mjsunit/constant-fold-control-instructions.js

@@ -26,10 +26,6 @@ function test() {
 
   assertTrue(%_IsJSReceiver(new Date()));
   assertFalse(%_IsJSReceiver(1));
-
-  assertTrue(%_IsMinusZero(-0.0));
-  assertFalse(%_IsMinusZero(1));
-  assertFalse(%_IsMinusZero(""));
 }