diff --git a/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h b/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h
new file mode 100644
--- /dev/null
+++ b/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.h
@@ -0,0 +1,56 @@
+//===---- RISCVISelDAGToDAG.h - A dag to dag inst selector for RISCV ------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines an instruction selector for the RISCV target.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_RISCV_RISCVISELDAGTODAG_H
+#define LLVM_LIB_TARGET_RISCV_RISCVISELDAGTODAG_H
+
+#include "RISCV.h"
+#include "RISCVTargetMachine.h"
+#include "llvm/CodeGen/SelectionDAGISel.h"
+
+// RISCV-specific code to select RISCV machine instructions for
+// SelectionDAG operations.
+namespace llvm {
+class RISCVDAGToDAGISel final : public SelectionDAGISel {
+  const RISCVSubtarget *Subtarget = nullptr;
+
+public:
+  explicit RISCVDAGToDAGISel(RISCVTargetMachine &TargetMachine)
+      : SelectionDAGISel(TargetMachine) {}
+
+  StringRef getPassName() const override {
+    return "RISCV DAG->DAG Pattern Instruction Selection";
+  }
+
+  bool runOnMachineFunction(MachineFunction &MF) override {
+    Subtarget = &MF.getSubtarget<RISCVSubtarget>();
+    return SelectionDAGISel::runOnMachineFunction(MF);
+  }
+
+  void PostprocessISelDAG() override;
+
+  void Select(SDNode *Node) override;
+
+  bool SelectInlineAsmMemoryOperand(const SDValue &Op, unsigned ConstraintID,
+                                    std::vector<SDValue> &OutOps) override;
+
+  bool SelectAddrFI(SDValue Addr, SDValue &Base);
+
+// Include the pieces autogenerated from the target description.
+#include "RISCVGenDAGISel.inc"
+
+private:
+  void doPeepholeLoadStoreADDI();
+};
+}
+
+#endif
diff --git a/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp b/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
--- a/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelDAGToDAG.cpp
@@ -10,55 +10,18 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "RISCVISelDAGToDAG.h"
 #include "MCTargetDesc/RISCVMCTargetDesc.h"
-#include "RISCV.h"
-#include "RISCVTargetMachine.h"
 #include "Utils/RISCVMatInt.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
-#include "llvm/CodeGen/SelectionDAGISel.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
 #include "llvm/Support/raw_ostream.h"
+
 using namespace llvm;
 
 #define DEBUG_TYPE "riscv-isel"
 
-// RISCV-specific code to select RISCV machine instructions for
-// SelectionDAG operations.
-namespace {
-class RISCVDAGToDAGISel final : public SelectionDAGISel {
-  const RISCVSubtarget *Subtarget = nullptr;
-
-public:
-  explicit RISCVDAGToDAGISel(RISCVTargetMachine &TargetMachine)
-      : SelectionDAGISel(TargetMachine) {}
-
-  StringRef getPassName() const override {
-    return "RISCV DAG->DAG Pattern Instruction Selection";
-  }
-
-  bool runOnMachineFunction(MachineFunction &MF) override {
-    Subtarget = &MF.getSubtarget<RISCVSubtarget>();
-    return SelectionDAGISel::runOnMachineFunction(MF);
-  }
-
-  void PostprocessISelDAG() override;
-
-  void Select(SDNode *Node) override;
-
-  bool SelectInlineAsmMemoryOperand(const SDValue &Op, unsigned ConstraintID,
-                                    std::vector<SDValue> &OutOps) override;
-
-  bool SelectAddrFI(SDValue Addr, SDValue &Base);
-
-// Include the pieces autogenerated from the target description.
-#include "RISCVGenDAGISel.inc"
-
-private:
-  void doPeepholeLoadStoreADDI();
-};
-}
-
 void RISCVDAGToDAGISel::PostprocessISelDAG() {
   doPeepholeLoadStoreADDI();
 }