[x86] Clarify that this lowering only applies to vectors and is only

used when we have SSE2.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212300 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 67fa64b29fd37c65c31087b185739078135977b3..7488cece60395f96d2eee32a557f29a9ed30fc2d 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -15481,15 +15481,14 @@ static SDValue LowerScalarVariableShift(SDValue Op, SelectionDAG &DAG,
 
 static SDValue LowerShift(SDValue Op, const X86Subtarget* Subtarget,
                           SelectionDAG &DAG) {
-
   MVT VT = Op.getSimpleValueType();
   SDLoc dl(Op);
   SDValue R = Op.getOperand(0);
   SDValue Amt = Op.getOperand(1);
   SDValue V;
 
-  if (!Subtarget->hasSSE2())
-    return SDValue();
+  assert(VT.isVector() && "Custom lowering only for vector shifts!");
+  assert(Subtarget->hasSSE2() && "Only custom lower when we have SSE2!");
 
   V = LowerScalarImmediateShift(Op, DAG, Subtarget);
   if (V.getNode())