1 files changed, 5 insertions, 4 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index 1cb39f65e8b..0365862cc16 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -1612,10 +1612,6 @@ const SCEV *ScalarEvolution::getSignExtendExpr(const SCEV *Op,
   void *IP = nullptr;
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;
 
-  // If the input value is provably positive, build a zext instead.
-  if (isKnownNonNegative(Op))
-    return getZeroExtendExpr(Op, Ty);
-
   // sext(trunc(x)) --> sext(x) or x or trunc(x)
   if (const SCEVTruncateExpr *ST = dyn_cast<SCEVTruncateExpr>(Op)) {
     // It's possible the bits taken off by the truncate were all sign bits. If
@@ -1781,6 +1777,11 @@ const SCEV *ScalarEvolution::getSignExtendExpr(const SCEV *Op,
       }
     }
 
+  // If the input value is provably positive and we could not simplify
+  // away the sext build a zext instead.
+  if (isKnownNonNegative(Op))
+    return getZeroExtendExpr(Op, Ty);
+
   // The cast wasn't folded; create an explicit cast node.
   // Recompute the insert position, as it may have been invalidated.
   if (const SCEV *S = UniqueSCEVs.FindNodeOrInsertPos(ID, IP)) return S;