[InstCombine] fix constant to be signed for signed comparisons

This bug was introduced in r269728 and is the likely cause of many stage 2 ubsan bot failures.
I'll add a test in a follow-up commit assuming this fixes things properly.

llvm-svn: 269797

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 447c43763f3..f51cf7321f2 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -3150,7 +3150,7 @@ static ICmpInst *canonicalizeCmpWithConstant(ICmpInst &I) {
 
   // Increment or decrement the constant and set the new comparison predicate:
   // ULE -> ULT ; UGE -> UGT ; SLE -> SLT ; SGE -> SGT
-  Constant *OneOrNegOne = ConstantInt::get(Op1Type, IsLE ? 1 : -1);
+  Constant *OneOrNegOne = ConstantInt::get(Op1Type, IsLE ? 1 : -1, IsSigned);
   CmpInst::Predicate NewPred = IsLE ? ICmpInst::ICMP_ULT: ICmpInst::ICMP_UGT;
   NewPred = IsSigned ? ICmpInst::getSignedPredicate(NewPred) : NewPred;
   return new ICmpInst(NewPred, Op0, ConstantExpr::getAdd(Op1C, OneOrNegOne));