[RISCV] Extract tryUnsignedBitfieldExtract as a member function of RISCVDAGToDAGISel. NFC.

Author: tclin914

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp

@@ -663,6 +663,20 @@ bool RISCVDAGToDAGISel::trySignedBitfieldExtract(SDNode *Node) {
   return false;
 }
 
+bool RISCVDAGToDAGISel::tryUnsignedBitfieldExtract(SDNode *Node, SDLoc DL,
+                                                   MVT VT, SDValue X,
+                                                   unsigned Msb, unsigned Lsb) {
+  // Only supported with XTHeadBb at the moment.
+  if (!Subtarget->hasVendorXTHeadBb())
+    return false;
+
+  SDNode *TH_EXTU = CurDAG->getMachineNode(
+      RISCV::TH_EXTU, DL, VT, X, CurDAG->getTargetConstant(Msb, DL, VT),
+      CurDAG->getTargetConstant(Lsb, DL, VT));
+  ReplaceNode(Node, TH_EXTU);
+  return true;
+}
+
 bool RISCVDAGToDAGISel::tryIndexedLoad(SDNode *Node) {
   // Target does not support indexed loads.
   if (!Subtarget->hasVendorXTHeadMemIdx())
@@ -1122,16 +1136,12 @@ void RISCVDAGToDAGISel::Select(SDNode *Node) {
       return;
     }
 
-    unsigned LShAmt = Subtarget->getXLen() - TrailingOnes;
-    if (Subtarget->hasVendorXTHeadBb()) {
-      SDNode *THEXTU = CurDAG->getMachineNode(
-          RISCV::TH_EXTU, DL, VT, N0->getOperand(0),
-          CurDAG->getTargetConstant(TrailingOnes - 1, DL, VT),
-          CurDAG->getTargetConstant(ShAmt, DL, VT));
-      ReplaceNode(Node, THEXTU);
+    const unsigned Msb = TrailingOnes - 1;
+    const unsigned Lsb = ShAmt;
+    if (tryUnsignedBitfieldExtract(Node, DL, VT, N0->getOperand(0), Msb, Lsb))
       return;
-    }
 
+    unsigned LShAmt = Subtarget->getXLen() - TrailingOnes;
     SDNode *SLLI =
         CurDAG->getMachineNode(RISCV::SLLI, DL, VT, N0->getOperand(0),
                                CurDAG->getTargetConstant(LShAmt, DL, VT));
@@ -1188,19 +1198,6 @@ void RISCVDAGToDAGISel::Select(SDNode *Node) {
 
     SDValue N0 = Node->getOperand(0);
 
-    auto tryUnsignedBitfieldExtract = [&](SDNode *Node, SDLoc DL, MVT VT,
-                                          SDValue X, unsigned Msb,
-                                          unsigned Lsb) {
-      if (!Subtarget->hasVendorXTHeadBb())
-        return false;
-
-      SDNode *TH_EXTU = CurDAG->getMachineNode(
-          RISCV::TH_EXTU, DL, VT, X, CurDAG->getTargetConstant(Msb, DL, VT),
-          CurDAG->getTargetConstant(Lsb, DL, VT));
-      ReplaceNode(Node, TH_EXTU);
-      return true;
-    };
-
     bool LeftShift = N0.getOpcode() == ISD::SHL;
     if (LeftShift || N0.getOpcode() == ISD::SRL) {
       auto *C = dyn_cast<ConstantSDNode>(N0.getOperand(1));

llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h

@@ -81,6 +81,8 @@ class RISCVDAGToDAGISel : public SelectionDAGISel {
 
   bool tryShrinkShlLogicImm(SDNode *Node);
   bool trySignedBitfieldExtract(SDNode *Node);
+  bool tryUnsignedBitfieldExtract(SDNode *Node, SDLoc DL, MVT VT, SDValue X,
+                                  unsigned Msb, unsigned Lsb);
   bool tryIndexedLoad(SDNode *Node);
 
   bool selectShiftMask(SDValue N, unsigned ShiftWidth, SDValue &ShAmt);