When forming an ICmpZero LSRUse, normalize the non-IV operand
of the comparison, so that the resulting expression is fully
normalized. This fixes PR9939.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131576 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 0d617bf..886e143 100644
--- a/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -2073,6 +2073,10 @@
// x == y --> x - y == 0
const SCEV *N = SE.getSCEV(NV);
if (SE.isLoopInvariant(N, L)) {
+ // S is normalized, so normalize N before folding it into S
+ // to keep the result normalized.
+ N = TransformForPostIncUse(Normalize, N, CI, 0,
+ LF.PostIncLoops, SE, DT);
Kind = LSRUse::ICmpZero;
S = SE.getMinusSCEV(N, S);
}