[X86] Address post-commit review from code I accidentally commited in r373136.

See https://reviews.llvm.org/D68167

llvm-svn: 373245

Author: topperc

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -43479,16 +43479,19 @@ static SDValue combineAdd(SDNode *N, SelectionDAG &DAG,
   // FIXME: We have the (sub Y, (zext (vXi1 X))) -> (add (sext (vXi1 X)), Y) in
   // generic DAG combine without a legal type check, but adding this there
   // caused regressions.
-  if (Subtarget.hasAVX512() && VT.isVector()) {
+  if (VT.isVector()) {
+    const TargetLowering &TLI = DAG.getTargetLoweringInfo();
     if (Op0.getOpcode() == ISD::ZERO_EXTEND &&
-        Op0.getOperand(0).getValueType().getVectorElementType() == MVT::i1) {
+        Op0.getOperand(0).getValueType().getVectorElementType() == MVT::i1 &&
+        TLI.isTypeLegal(Op0.getOperand(0).getValueType())) {
       SDLoc DL(N);
       SDValue SExt = DAG.getNode(ISD::SIGN_EXTEND, DL, VT, Op0.getOperand(0));
       return DAG.getNode(ISD::SUB, DL, VT, Op1, SExt);
     }
 
     if (Op1.getOpcode() == ISD::ZERO_EXTEND &&
-        Op1.getOperand(0).getValueType().getVectorElementType() == MVT::i1) {
+        Op1.getOperand(0).getValueType().getVectorElementType() == MVT::i1 &&
+        TLI.isTypeLegal(Op1.getOperand(0).getValueType())) {
       SDLoc DL(N);
       SDValue SExt = DAG.getNode(ISD::SIGN_EXTEND, DL, VT, Op1.getOperand(0));
       return DAG.getNode(ISD::SUB, DL, VT, Op0, SExt);