In ChangeCompareStride, when the stride to be reused is truncated to
a smaller type, promoted its offset back up to the type of the new
comparison. This fixes PR4222.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72493 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index adfa527..834a95d 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -2005,11 +2005,16 @@
ConstantInt *CI = ConstantInt::get(NewCmpIntTy, NewCmpVal);
NewCmpRHS = ConstantExpr::getIntToPtr(CI, NewCmpTy);
}
+ NewOffset = CondUse->getOffset();
+ if (CondUse->isSigned())
+ NewOffset = SE->getNoopOrSignExtend(CondUse->getOffset(), NewCmpTy);
+ else
+ NewOffset = SE->getNoopOrZeroExtend(CondUse->getOffset(), NewCmpTy);
NewOffset = TyBits == NewTyBits
- ? SE->getMulExpr(CondUse->getOffset(),
+ ? SE->getMulExpr(NewOffset,
SE->getConstant(ConstantInt::get(CmpTy, Scale)))
: SE->getConstant(ConstantInt::get(NewCmpIntTy,
- cast<SCEVConstant>(CondUse->getOffset())->getValue()
+ cast<SCEVConstant>(NewOffset)->getValue()
->getSExtValue()*Scale));
break;
}