diff --git a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
index d93b6432e6e9fa1edad042a7ae4f793b34ebc810..728880919501a7e47c86829349f8e9f1fde5fb7c 100644
--- a/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -784,9 +784,6 @@ static void ComputeMaskedBits(Value *V, const APInt &Mask, APInt& KnownZero,
       KnownZero = APIntOps::lshr(KnownZero, ShiftAmt);
       KnownOne  = APIntOps::lshr(KnownOne, ShiftAmt);
         
-      // Handle the sign bits and adjust to where it is now in the mask.
-      APInt SignBit(APInt::getSignBit(BitWidth).lshr(ShiftAmt));
-        
       APInt HighBits(APInt::getHighBitsSet(BitWidth, ShiftAmt));
       if (KnownZero[BitWidth-ShiftAmt-1])    // New bits are known zero.
         KnownZero |= HighBits;