[X86] Don't use SplitOpsAndApply for ISD::USUBSAT.

Target independent type legalization and custom lowering
should be able to handle it.

llvm-svn: 368537

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -42896,16 +42896,10 @@ static SDValue combineSubToSubus(SDNode *N, SelectionDAG &DAG,
   } else
     return SDValue();
 
-  auto USUBSATBuilder = [](SelectionDAG &DAG, const SDLoc &DL,
-                           ArrayRef<SDValue> Ops) {
-    return DAG.getNode(ISD::USUBSAT, DL, Ops[0].getValueType(), Ops);
-  };
-
   // PSUBUS doesn't support v8i32/v8i64/v16i32, but it can be enabled with
   // special preprocessing in some cases.
   if (VT != MVT::v8i32 && VT != MVT::v16i32 && VT != MVT::v8i64)
-    return SplitOpsAndApply(DAG, Subtarget, SDLoc(N), VT,
-                            { SubusLHS, SubusRHS }, USUBSATBuilder);
+    return DAG.getNode(ISD::USUBSAT, SDLoc(N), VT, SubusLHS, SubusRHS);
 
   // Special preprocessing case can be only applied
   // if the value was zero extended from 16 bit,
@@ -42934,9 +42928,9 @@ static SDValue combineSubToSubus(SDNode *N, SelectionDAG &DAG,
   SDValue NewSubusLHS =
       DAG.getZExtOrTrunc(SubusLHS, SDLoc(SubusLHS), ShrinkedType);
   SDValue NewSubusRHS = DAG.getZExtOrTrunc(UMin, SDLoc(SubusRHS), ShrinkedType);
-  SDValue Psubus =
-      SplitOpsAndApply(DAG, Subtarget, SDLoc(N), ShrinkedType,
-                       { NewSubusLHS, NewSubusRHS }, USUBSATBuilder);
+  SDValue Psubus = DAG.getNode(ISD::USUBSAT, SDLoc(N), ShrinkedType,
+                               NewSubusLHS, NewSubusRHS);
+
   // Zero extend the result, it may be used somewhere as 32 bit,
   // if not zext and following trunc will shrink.
   return DAG.getZExtOrTrunc(Psubus, SDLoc(N), ExtType);