| Index: src/x64/lithium-x64.cc | 
| diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc | 
| index f49f7d67f97f117dbc5c25b08414d05a179e662e..ef52d87380d00c96a8501749d4c046d52c9b8704 100644 | 
| --- a/src/x64/lithium-x64.cc | 
| +++ b/src/x64/lithium-x64.cc | 
| @@ -782,8 +782,8 @@ LInstruction* LChunkBuilder::DoArithmeticD(Token::Value op, | 
| ASSERT(instr->left()->representation().IsDouble()); | 
| ASSERT(instr->right()->representation().IsDouble()); | 
| ASSERT(op != Token::MOD); | 
| -  LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand()); | 
| -  LOperand* right = UseRegisterAtStart(instr->BetterRightOperand()); | 
| +  LOperand* left = UseRegisterAtStart(instr->left()); | 
| +  LOperand* right = UseRegisterAtStart(instr->right()); | 
| LArithmeticD* result = new(zone()) LArithmeticD(op, left, right); | 
| return DefineSameAsFirst(result); | 
| } | 
| @@ -1309,8 +1309,8 @@ LInstruction* LChunkBuilder::DoBitwise(HBitwise* instr) { | 
| ASSERT(instr->left()->representation().IsInteger32()); | 
| ASSERT(instr->right()->representation().IsInteger32()); | 
|  | 
| -    LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand()); | 
| -    LOperand* right = UseOrConstantAtStart(instr->BetterRightOperand()); | 
| +    LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand()); | 
| +    LOperand* right = UseOrConstantAtStart(instr->MostConstantOperand()); | 
| return DefineSameAsFirst(new(zone()) LBitI(left, right)); | 
| } else { | 
| ASSERT(instr->representation().IsTagged()); | 
| @@ -1473,8 +1473,8 @@ LInstruction* LChunkBuilder::DoMul(HMul* instr) { | 
| if (instr->representation().IsInteger32()) { | 
| ASSERT(instr->left()->representation().IsInteger32()); | 
| ASSERT(instr->right()->representation().IsInteger32()); | 
| -    LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand()); | 
| -    LOperand* right = UseOrConstant(instr->BetterRightOperand()); | 
| +    LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand()); | 
| +    LOperand* right = UseOrConstant(instr->MostConstantOperand()); | 
| LMulI* mul = new(zone()) LMulI(left, right); | 
| if (instr->CheckFlag(HValue::kCanOverflow) || | 
| instr->CheckFlag(HValue::kBailoutOnMinusZero)) { | 
| @@ -1513,24 +1513,13 @@ LInstruction* LChunkBuilder::DoSub(HSub* instr) { | 
|  | 
| LInstruction* LChunkBuilder::DoAdd(HAdd* instr) { | 
| if (instr->representation().IsInteger32()) { | 
| -    // Check to see if it would be advantageous to use an lea instruction rather | 
| -    // than an add. This is the case when no overflow check is needed and there | 
| -    // are multiple uses of the add's inputs, so using a 3-register add will | 
| -    // preserve all input values for later uses. | 
| -    bool use_lea = LAddI::UseLea(instr); | 
| ASSERT(instr->left()->representation().IsInteger32()); | 
| ASSERT(instr->right()->representation().IsInteger32()); | 
| -    LOperand* left = UseRegisterAtStart(instr->BetterLeftOperand()); | 
| -    HValue* right_candidate = instr->BetterRightOperand(); | 
| -    LOperand* right = use_lea | 
| -        ? UseRegisterOrConstantAtStart(right_candidate) | 
| -        : UseOrConstantAtStart(right_candidate); | 
| +    LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand()); | 
| +    LOperand* right = UseOrConstantAtStart(instr->MostConstantOperand()); | 
| LAddI* add = new(zone()) LAddI(left, right); | 
| -    bool can_overflow = instr->CheckFlag(HValue::kCanOverflow); | 
| -    LInstruction* result = use_lea | 
| -        ? DefineAsRegister(add) | 
| -        : DefineSameAsFirst(add); | 
| -    if (can_overflow) { | 
| +    LInstruction* result = DefineSameAsFirst(add); | 
| +    if (instr->CheckFlag(HValue::kCanOverflow)) { | 
| result = AssignEnvironment(result); | 
| } | 
| return result; | 
| @@ -1550,8 +1539,8 @@ LInstruction* LChunkBuilder::DoMathMinMax(HMathMinMax* instr) { | 
| if (instr->representation().IsInteger32()) { | 
| ASSERT(instr->left()->representation().IsInteger32()); | 
| ASSERT(instr->right()->representation().IsInteger32()); | 
| -    left = UseRegisterAtStart(instr->BetterLeftOperand()); | 
| -    right = UseOrConstantAtStart(instr->BetterRightOperand()); | 
| +    left = UseRegisterAtStart(instr->LeastConstantOperand()); | 
| +    right = UseOrConstantAtStart(instr->MostConstantOperand()); | 
| } else { | 
| ASSERT(instr->representation().IsDouble()); | 
| ASSERT(instr->left()->representation().IsDouble()); | 
|  |