| Index: src/x64/code-stubs-x64.cc | 
| diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc | 
| index ca6779ecf8cebb57ff322d8009d450c1262109b2..181ceb79ad876d08219d12a8c06925d6d86fae8b 100644 | 
| --- a/src/x64/code-stubs-x64.cc | 
| +++ b/src/x64/code-stubs-x64.cc | 
| @@ -1111,16 +1111,11 @@ void CompareICStub::GenerateGeneric(MacroAssembler* masm) { | 
| // Check for undefined.  undefined OP undefined is false even though | 
| // undefined == undefined. | 
| __ CompareRoot(rdx, Heap::kUndefinedValueRootIndex); | 
| -      if (is_strong(strength())) { | 
| -        // In strong mode, this comparison must throw, so call the runtime. | 
| -        __ j(equal, &runtime_call, Label::kFar); | 
| -      } else { | 
| -        Label check_for_nan; | 
| -        __ j(not_equal, &check_for_nan, Label::kNear); | 
| -        __ Set(rax, NegativeComparisonResult(cc)); | 
| -        __ ret(0); | 
| -        __ bind(&check_for_nan); | 
| -      } | 
| +      Label check_for_nan; | 
| +      __ j(not_equal, &check_for_nan, Label::kNear); | 
| +      __ Set(rax, NegativeComparisonResult(cc)); | 
| +      __ ret(0); | 
| +      __ bind(&check_for_nan); | 
| } | 
|  | 
| // Test for NaN. Sadly, we can't just compare to Factory::nan_value(), | 
| @@ -1142,12 +1137,6 @@ void CompareICStub::GenerateGeneric(MacroAssembler* masm) { | 
| // Call runtime on identical SIMD values since we must throw a TypeError. | 
| __ cmpb(rcx, Immediate(static_cast<uint8_t>(SIMD128_VALUE_TYPE))); | 
| __ j(equal, &runtime_call, Label::kFar); | 
| -      if (is_strong(strength())) { | 
| -        // We have already tested for smis and heap numbers, so if both | 
| -        // arguments are not strings we must proceed to the slow case. | 
| -        __ testb(rcx, Immediate(kIsNotStringMask)); | 
| -        __ j(not_zero, &runtime_call, Label::kFar); | 
| -      } | 
| } | 
| __ Set(rax, EQUAL); | 
| __ ret(0); | 
| @@ -1343,8 +1332,7 @@ void CompareICStub::GenerateGeneric(MacroAssembler* masm) { | 
| } else { | 
| __ Push(Smi::FromInt(NegativeComparisonResult(cc))); | 
| __ PushReturnAddressFrom(rcx); | 
| -    __ TailCallRuntime(is_strong(strength()) ? Runtime::kCompare_Strong | 
| -                                             : Runtime::kCompare); | 
| +    __ TailCallRuntime(Runtime::kCompare); | 
| } | 
|  | 
| __ bind(&miss); | 
| @@ -2901,21 +2889,17 @@ void CompareICStub::GenerateBooleans(MacroAssembler* masm) { | 
| __ movp(rbx, FieldOperand(rax, HeapObject::kMapOffset)); | 
| __ JumpIfNotRoot(rcx, Heap::kBooleanMapRootIndex, &miss, miss_distance); | 
| __ JumpIfNotRoot(rbx, Heap::kBooleanMapRootIndex, &miss, miss_distance); | 
| -  if (op() != Token::EQ_STRICT && is_strong(strength())) { | 
| -    __ TailCallRuntime(Runtime::kThrowStrongModeImplicitConversion); | 
| -  } else { | 
| -    if (!Token::IsEqualityOp(op())) { | 
| -      __ movp(rax, FieldOperand(rax, Oddball::kToNumberOffset)); | 
| -      __ AssertSmi(rax); | 
| -      __ movp(rdx, FieldOperand(rdx, Oddball::kToNumberOffset)); | 
| -      __ AssertSmi(rdx); | 
| -      __ pushq(rax); | 
| -      __ movq(rax, rdx); | 
| -      __ popq(rdx); | 
| -    } | 
| -    __ subp(rax, rdx); | 
| -    __ Ret(); | 
| +  if (!Token::IsEqualityOp(op())) { | 
| +    __ movp(rax, FieldOperand(rax, Oddball::kToNumberOffset)); | 
| +    __ AssertSmi(rax); | 
| +    __ movp(rdx, FieldOperand(rdx, Oddball::kToNumberOffset)); | 
| +    __ AssertSmi(rdx); | 
| +    __ pushq(rax); | 
| +    __ movq(rax, rdx); | 
| +    __ popq(rdx); | 
| } | 
| +  __ subp(rax, rdx); | 
| +  __ Ret(); | 
|  | 
| __ bind(&miss); | 
| GenerateMiss(masm); | 
| @@ -2998,7 +2982,7 @@ void CompareICStub::GenerateNumbers(MacroAssembler* masm) { | 
|  | 
| __ bind(&unordered); | 
| __ bind(&generic_stub); | 
| -  CompareICStub stub(isolate(), op(), strength(), CompareICState::GENERIC, | 
| +  CompareICStub stub(isolate(), op(), CompareICState::GENERIC, | 
| CompareICState::GENERIC, CompareICState::GENERIC); | 
| __ jmp(stub.GetCode(), RelocInfo::CODE_TARGET); | 
|  | 
| @@ -3232,8 +3216,6 @@ void CompareICStub::GenerateKnownReceivers(MacroAssembler* masm) { | 
| if (Token::IsEqualityOp(op())) { | 
| __ subp(rax, rdx); | 
| __ ret(0); | 
| -  } else if (is_strong(strength())) { | 
| -    __ TailCallRuntime(Runtime::kThrowStrongModeImplicitConversion); | 
| } else { | 
| __ PopReturnAddressTo(rcx); | 
| __ Push(rdx); | 
|  |