[X86] Remove custom lowering of vXi1 ADD/SUB now that they are canonicalized to XOR in getNode.

[RKSimon]

LGTM

[RKSimon]

llvm/lib/Target/X86/X86ISelLowering.cpp

1475

I've moved the ADD/SUB SAT folds at rG9490b9f14b899ff07f3cfab7ad64e5fed8f48746 - are you OK with me removing these as well?

[craig.topper]

llvm/lib/Target/X86/X86ISelLowering.cpp

1475

Yes. What about MUL?

llvm/lib/Target/X86/X86ISelLowering.cpp

if (!Subtarget.useSoftFloat() && Subtarget.hasAVX512()) {
     // Extends of v16i1/v8i1/v4i1/v2i1 to 128-bit vectors.
     for (auto VT : { MVT::v16i8, MVT::v8i16, MVT::v4i32, MVT::v2i64 }) {
       setOperationAction(ISD::SIGN_EXTEND, VT, Custom);
       setOperationAction(ISD::ZERO_EXTEND, VT, Custom);
       setOperationAction(ISD::ANY_EXTEND,  VT, Custom);
     }
 
     for (auto VT : { MVT::v1i1, MVT::v2i1, MVT::v4i1, MVT::v8i1, MVT::v16i1 }) {
-      setOperationAction(ISD::ADD,              VT, Custom);
-      setOperationAction(ISD::SUB,              VT, Custom);
       setOperationAction(ISD::MUL,              VT, Custom);
       setOperationAction(ISD::UADDSAT,          VT, Custom);
       setOperationAction(ISD::SADDSAT,          VT, Custom);
       setOperationAction(ISD::USUBSAT,          VT, Custom);
       setOperationAction(ISD::SSUBSAT,          VT, Custom);
       setOperationAction(ISD::VSELECT,          VT,  Expand);
     }
 
     for (auto VT : { MVT::v2i1, MVT::v4i1, MVT::v8i1, MVT::v16i1 }) {
       setOperationAction(ISD::SETCC,            VT, Custom);
       setOperationAction(ISD::STRICT_FSETCC,    VT, Custom);
       setOperationAction(ISD::STRICT_FSETCCS,   VT, Custom);
       setOperationAction(ISD::SELECT,           VT, Custom);

 }
 
 static SDValue lowerAddSub(SDValue Op, SelectionDAG &DAG,
                            const X86Subtarget &Subtarget) {
   MVT VT = Op.getSimpleValueType();
   if (VT == MVT::i16 || VT == MVT::i32)
     return lowerAddSubToHorizontalOp(Op, DAG, Subtarget);
 
-  if (VT.getScalarType() == MVT::i1)
-    return DAG.getNode(ISD::XOR, SDLoc(Op), VT,
-                       Op.getOperand(0), Op.getOperand(1));
-
   if (VT == MVT::v32i16 || VT == MVT::v64i8)
     return splitVectorIntBinary(Op, DAG);
 
   assert(Op.getSimpleValueType().is256BitVector() &&
          Op.getSimpleValueType().isInteger() &&
          "Only handle AVX 256-bit vector integer operation");
   return splitVectorIntBinary(Op, DAG);
 }