1 files changed, 12 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index d784eb9ace4..42e38ca8049 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -1559,6 +1559,18 @@ const SCEV *ScalarEvolution::getZeroExtendExpr(const SCEV *Op,
       }
     }
 
+  if (auto *SA = dyn_cast<SCEVAddExpr>(Op)) {
+    // zext((A + B + ...)<nuw>) --> (zext(A) + zext(B) + ...)<nuw>
+    if (SA->getNoWrapFlags(SCEV::FlagNUW)) {
+      // If the addition does not unsign overflow then we can, by definition,
+      // commute the zero extension with the addition operation.
+      SmallVector<const SCEV *, 4> Ops;
+      for (const auto *Op : SA->operands())
+        Ops.push_back(getZeroExtendExpr(Op, Ty));
+      return getAddExpr(Ops, SCEV::FlagNUW);
+    }
+  }
+
   // 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;