[X86] Move IsNOT helper after getTargetConstantBitsFromNode helper. NFC.

A future patch will use getTargetConstantBitsFromNode inside IsNOT.

Author: RKSimon

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -4324,35 +4324,6 @@ static SDValue getBitSelect(const SDLoc &DL, MVT VT, SDValue LHS, SDValue RHS,
   return DAG.getNode(ISD::OR, DL, VT, LHS, RHS);
 }
 
-// Match (xor X, -1) -> X.
-// Match extract_subvector(xor X, -1) -> extract_subvector(X).
-// Match concat_vectors(xor X, -1, xor Y, -1) -> concat_vectors(X, Y).
-static SDValue IsNOT(SDValue V, SelectionDAG &DAG) {
-  V = peekThroughBitcasts(V);
-  if (V.getOpcode() == ISD::XOR &&
-      (ISD::isBuildVectorAllOnes(V.getOperand(1).getNode()) ||
-       isAllOnesConstant(V.getOperand(1))))
-    return V.getOperand(0);
-  if (V.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
-      (isNullConstant(V.getOperand(1)) || V.getOperand(0).hasOneUse())) {
-    if (SDValue Not = IsNOT(V.getOperand(0), DAG)) {
-      Not = DAG.getBitcast(V.getOperand(0).getValueType(), Not);
-      return DAG.getNode(ISD::EXTRACT_SUBVECTOR, SDLoc(Not), V.getValueType(),
-                         Not, V.getOperand(1));
-    }
-  }
-  SmallVector<SDValue, 2> CatOps;
-  if (collectConcatOps(V.getNode(), CatOps, DAG)) {
-    for (SDValue &CatOp : CatOps) {
-      SDValue NotCat = IsNOT(CatOp, DAG);
-      if (!NotCat) return SDValue();
-      CatOp = DAG.getBitcast(CatOp.getValueType(), NotCat);
-    }
-    return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(V), V.getValueType(), CatOps);
-  }
-  return SDValue();
-}
-
 void llvm::createUnpackShuffleMask(EVT VT, SmallVectorImpl<int> &Mask,
                                    bool Lo, bool Unary) {
   assert(VT.getScalarType().isSimple() && (VT.getSizeInBits() % 128) == 0 &&
@@ -4910,6 +4881,35 @@ static bool getTargetShuffleMaskIndices(SDValue MaskNode,
   return true;
 }
 
+// Match (xor X, -1) -> X.
+// Match extract_subvector(xor X, -1) -> extract_subvector(X).
+// Match concat_vectors(xor X, -1, xor Y, -1) -> concat_vectors(X, Y).
+static SDValue IsNOT(SDValue V, SelectionDAG &DAG) {
+  V = peekThroughBitcasts(V);
+  if (V.getOpcode() == ISD::XOR &&
+      (ISD::isBuildVectorAllOnes(V.getOperand(1).getNode()) ||
+       isAllOnesConstant(V.getOperand(1))))
+    return V.getOperand(0);
+  if (V.getOpcode() == ISD::EXTRACT_SUBVECTOR &&
+      (isNullConstant(V.getOperand(1)) || V.getOperand(0).hasOneUse())) {
+    if (SDValue Not = IsNOT(V.getOperand(0), DAG)) {
+      Not = DAG.getBitcast(V.getOperand(0).getValueType(), Not);
+      return DAG.getNode(ISD::EXTRACT_SUBVECTOR, SDLoc(Not), V.getValueType(),
+                         Not, V.getOperand(1));
+    }
+  }
+  SmallVector<SDValue, 2> CatOps;
+  if (collectConcatOps(V.getNode(), CatOps, DAG)) {
+    for (SDValue &CatOp : CatOps) {
+      SDValue NotCat = IsNOT(CatOp, DAG);
+      if (!NotCat) return SDValue();
+      CatOp = DAG.getBitcast(CatOp.getValueType(), NotCat);
+    }
+    return DAG.getNode(ISD::CONCAT_VECTORS, SDLoc(V), V.getValueType(), CatOps);
+  }
+  return SDValue();
+}
+
 /// Create a shuffle mask that matches the PACKSS/PACKUS truncation.
 /// A multi-stage pack shuffle mask is created by specifying NumStages > 1.
 /// Note: This ignores saturation, so inputs must be checked first.