Index: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -16518,11 +16518,19 @@
     SDValue In = N->getOperand(0);
     assert(In.getValueType().isVector() && "Must concat vectors");
 
-    // Transform: concat_vectors(scalar, undef) -> scalar_to_vector(sclr).
-    if (In->getOpcode() == ISD::BITCAST &&
-        !In->getOperand(0).getValueType().isVector()) {
-      SDValue Scalar = In->getOperand(0);
+    SDValue Scalar = peekThroughOneUseBitcasts(In);
 
+    // concat_vectors(scalar_to_vector(scalar), undef) ->
+    //     scalar_to_vector(scalar)
+    if (!LegalOperations && Scalar.getOpcode() == ISD::SCALAR_TO_VECTOR &&
+         Scalar.hasOneUse()) {
+      EVT SVT = Scalar.getValueType().getVectorElementType();
+      if (SVT == Scalar.getOperand(0).getValueType())
+        Scalar = Scalar.getOperand(0);
+    }
+
+    // concat_vectors(scalar, undef) -> scalar_to_vector(scalar)
+    if (!Scalar.getValueType().isVector()) {
       // If the bitcast type isn't legal, it might be a trunc of a legal type;
       // look through the trunc so we can still do the transform:
       //   concat_vectors(trunc(scalar), undef) -> scalar_to_vector(scalar)
Index: llvm/trunk/test/CodeGen/X86/combine-concatvectors.ll
===================================================================
--- llvm/trunk/test/CodeGen/X86/combine-concatvectors.ll
+++ llvm/trunk/test/CodeGen/X86/combine-concatvectors.ll
@@ -5,8 +5,6 @@
 ; CHECK-LABEL: PR32957:
 ; CHECK:       # %bb.0:
 ; CHECK-NEXT:    vmovsd {{.*#+}} xmm0 = mem[0],zero
-; CHECK-NEXT:    vxorps %xmm1, %xmm1, %xmm1
-; CHECK-NEXT:    vblendps {{.*#+}} xmm0 = xmm0[0,1],xmm1[2,3]
 ; CHECK-NEXT:    vmovaps %ymm0, (%rsi)
 ; CHECK-NEXT:    vzeroupper
 ; CHECK-NEXT:    retq