diff --git a/llvm/include/llvm/Support/KnownBits.h b/llvm/include/llvm/Support/KnownBits.h
--- a/llvm/include/llvm/Support/KnownBits.h
+++ b/llvm/include/llvm/Support/KnownBits.h
@@ -111,7 +111,7 @@
   }
 
   /// Return the minimal value possible given these KnownBits.
-  APInt getMinValue(bool Signed = false) const {
+  APInt getMinValue() const {
     // Assume that all bits that aren't known-ones are zeros.
     return One;
   }