1 files changed, 6 insertions, 8 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index ce55b9e..1407f24 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -4086,8 +4086,8 @@ static ConstantRange computeConstantRangeIncludingKnownBits(
       V, DL, Depth, AC, CxtI, DT, ORE, UseInstrInfo);
   ConstantRange CR1 = ConstantRange::fromKnownBits(Known, ForSigned);
   ConstantRange CR2 = computeConstantRange(V, UseInstrInfo);
-  // TODO: Use ForSigned to determine preferred range.
-  ConstantRange::PreferredRangeType RangeType = ConstantRange::Smallest;
+  ConstantRange::PreferredRangeType RangeType =
+      ForSigned ? ConstantRange::Signed : ConstantRange::Unsigned;
   return CR1.intersectWith(CR2, RangeType);
 }
 
@@ -4133,12 +4133,10 @@ static OverflowResult computeOverflowForSignedAdd(const Value *LHS,
       ComputeNumSignBits(RHS, DL, 0, AC, CxtI, DT) > 1)
     return OverflowResult::NeverOverflows;
 
-  KnownBits LHSKnown = computeKnownBits(LHS, DL, /*Depth=*/0, AC, CxtI, DT);
-  KnownBits RHSKnown = computeKnownBits(RHS, DL, /*Depth=*/0, AC, CxtI, DT);
-  ConstantRange LHSRange =
-      ConstantRange::fromKnownBits(LHSKnown, /*signed*/ true);
-  ConstantRange RHSRange =
-      ConstantRange::fromKnownBits(RHSKnown, /*signed*/ true);
+  ConstantRange LHSRange = computeConstantRangeIncludingKnownBits(
+      LHS, /*ForSigned=*/true, DL, /*Depth=*/0, AC, CxtI, DT);
+  ConstantRange RHSRange = computeConstantRangeIncludingKnownBits(
+      RHS, /*ForSigned=*/true, DL, /*Depth=*/0, AC, CxtI, DT);
   OverflowResult OR =
       mapOverflowResult(LHSRange.signedAddMayOverflow(RHSRange));
   if (OR != OverflowResult::MayOverflow)