Fix PR23065. Avoid optimizing bitcast of build_vector with constant input to scalar_to_vector.

llvm-svn: 233778

1 files changed, 0 insertions, 5 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 0ac4b77fed5..19950f5dad1 100644
--- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -7024,7 +7024,6 @@ ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
 
   // Finally, this must be the case where we are shrinking elements: each input
   // turns into multiple outputs.
-  bool isS2V = ISD::isScalarToVector(BV);
   unsigned NumOutputsPerInput = SrcBitSize/DstBitSize;
   EVT VT = EVT::getVectorVT(*DAG.getContext(), DstEltVT,
                             NumOutputsPerInput*BV->getNumOperands());
@@ -7042,10 +7041,6 @@ ConstantFoldBITCASTofBUILD_VECTOR(SDNode *BV, EVT DstEltVT) {
     for (unsigned j = 0; j != NumOutputsPerInput; ++j) {
       APInt ThisVal = OpVal.trunc(DstBitSize);
       Ops.push_back(DAG.getConstant(ThisVal, DstEltVT));
-      if (isS2V && i == 0 && j == 0 && ThisVal.zext(SrcBitSize) == OpVal)
-        // Simply turn this into a SCALAR_TO_VECTOR of the new type.
-        return DAG.getNode(ISD::SCALAR_TO_VECTOR, SDLoc(BV), VT,
-                           Ops[0]);
       OpVal = OpVal.lshr(DstBitSize);
     }