[APInt] Add clearSignBit method. Use it and setSignBit in a few places. NFCI

llvm-svn: 301656

2 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
index 2e2116c60e6..4f1f1949976 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp
@@ -861,7 +861,7 @@ static bool checkRippleForAdd(const APInt &Op0KnownZero,
   // Find the most significant known 0 other than the sign bit.
   int BitWidth = Op0KnownZero.getBitWidth();
   APInt Op0KnownZeroTemp(Op0KnownZero);
-  Op0KnownZeroTemp.clearBit(BitWidth - 1);
+  Op0KnownZeroTemp.clearSignBit();
   int Op0ZeroPosition = BitWidth - Op0KnownZeroTemp.countLeadingZeros() - 1;
 
   int Op1OnePosition = BitWidth - Op1MaybeOne.countLeadingZeros() - 1;
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index d3b462e08b4..60970775de6 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -190,8 +190,8 @@ static void computeSignedMinMaxValuesFromKnownBits(const KnownBits &Known,
   Max = Known.One|UnknownBits;
 
   if (UnknownBits.isNegative()) { // Sign bit is unknown
-    Min.setBit(Min.getBitWidth()-1);
-    Max.clearBit(Max.getBitWidth()-1);
+    Min.setSignBit();
+    Max.clearSignBit();
   }
 }