1 files changed, 13 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 36cb2cd963a..cb737dcd787 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1536,6 +1536,19 @@ bool TargetLowering::SimplifyDemandedVectorElts(
     }
     break;
   }
+  case ISD::ADD:
+  case ISD::SUB: {
+    APInt SrcUndef, SrcZero;
+    if (SimplifyDemandedVectorElts(Op.getOperand(1), DemandedElts, SrcUndef,
+                                   SrcZero, TLO, Depth + 1))
+      return true;
+    if (SimplifyDemandedVectorElts(Op.getOperand(0), DemandedElts, KnownUndef,
+                                   KnownZero, TLO, Depth + 1))
+      return true;
+    KnownZero &= SrcZero;
+    KnownUndef &= SrcUndef;
+    break;
+  }
   case ISD::TRUNCATE:
     if (SimplifyDemandedVectorElts(Op.getOperand(0), DemandedElts, KnownUndef,
                                    KnownZero, TLO, Depth + 1))