Fix a bug in LinearFunctionTestReplace that created invalid loop exit checks.
Reviewed by Andy
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193303 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index 7785855..cfd8db0 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -1479,8 +1479,14 @@
if (IndVar->getType()->isPointerTy()
&& !IVCount->getType()->isPointerTy()) {
+ // IVOffset will be the new GEP offset that is interpreted by GEP as a
+ // signed value. IVCount on the other hand represents the loop trip count,
+ // which is an unsigned value. FindLoopCounter only allows induction
+ // variables that have a positive unit stride of one. This means we don't
+ // have to handle the case of negative offsets (yet) and just need to zero
+ // extend IVCount.
Type *OfsTy = SE->getEffectiveSCEVType(IVInit->getType());
- const SCEV *IVOffset = SE->getTruncateOrSignExtend(IVCount, OfsTy);
+ const SCEV *IVOffset = SE->getTruncateOrZeroExtend(IVCount, OfsTy);
// Expand the code for the iteration count.
assert(SE->isLoopInvariant(IVOffset, L) &&