[X86] Minor cleanup to getExtendInVec. NFCI

Use unsigned to calculate the subvector index to avoid a cast.

Remove an unnecessary condition and replace it with a stronger assert.

Use the InVT variable we updated when we extracted instead of grabbing it from the In SDValue.

llvm-svn: 346983

1 files changed, 7 insertions, 4 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index ecdabf6..4d1d8ae1 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -5492,17 +5492,20 @@ static SDValue getOnesVector(EVT VT, SelectionDAG &DAG, const SDLoc &dl) {
 static SDValue getExtendInVec(bool Signed, const SDLoc &DL, EVT VT, SDValue In,
                               SelectionDAG &DAG) {
   EVT InVT = In.getValueType();
+  assert(VT.isVector() && InVT.isVector() && "Expected vector VTs.");
 
   // For 256-bit vectors, we only need the lower (128-bit) input half.
   // For 512-bit vectors, we only need the lower input half or quarter.
-  if (VT.getSizeInBits() > 128 && InVT.getSizeInBits() > 128) {
-    int Scale = VT.getScalarSizeInBits() / InVT.getScalarSizeInBits();
+  if (InVT.getSizeInBits() > 128) {
+    assert(VT.getSizeInBits() == InVT.getSizeInBits() &&
+           "Expected VTs to be the same size!");
+    unsigned Scale = VT.getScalarSizeInBits() / InVT.getScalarSizeInBits();
     In = extractSubVector(In, 0, DAG, DL,
-                          std::max(128, (int)VT.getSizeInBits() / Scale));
+                          std::max(128U, VT.getSizeInBits() / Scale));
     InVT = In.getValueType();
   }
 
-  if (VT.getVectorNumElements() == In.getValueType().getVectorNumElements())
+  if (VT.getVectorNumElements() == InVT.getVectorNumElements())
     return DAG.getNode(Signed ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND,
                        DL, VT, In);