lib/Target/RISCV/RISCVISelLowering.h

//===-- RISCVISelLowering.h - RISCV DAG Lowering Interface ------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the interfaces that RISCV uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_RISCV_RISCVISELLOWERING_H
#define LLVM_LIB_TARGET_RISCV_RISCVISELLOWERING_H

#include "RISCV.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/Target/TargetLowering.h"

namespace llvm {
class RISCVSubtarget;
namespace RISCVISD {
enum NodeType : unsigned {
  FIRST_NUMBER = ISD::BUILTIN_OP_END,
  RET_FLAG,
  CALL
};
}

class RISCVTargetLowering : public TargetLowering {
  const RISCVSubtarget &Subtarget;

public:
  explicit RISCVTargetLowering(const TargetMachine &TM,
                               const RISCVSubtarget &STI);

  // Provide custom lowering hooks for some operations.
  SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;

  // This method returns the name of a target specific DAG node.
  const char *getTargetNodeName(unsigned Opcode) const override;

private:
  // Lower incoming arguments, copy physregs into vregs
  SDValue LowerFormalArguments(SDValue Chain, CallingConv::ID CallConv,
                               bool IsVarArg,
                               const SmallVectorImpl<ISD::InputArg> &Ins,
                               const SDLoc &DL, SelectionDAG &DAG,
                               SmallVectorImpl<SDValue> &InVals) const override;
  SDValue LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool IsVarArg,
                      const SmallVectorImpl<ISD::OutputArg> &Outs,
                      const SmallVectorImpl<SDValue> &OutVals, const SDLoc &DL,
                      SelectionDAG &DAG) const override;
  SDValue LowerCall(TargetLowering::CallLoweringInfo &CLI,
                    SmallVectorImpl<SDValue> &InVals) const override;
  bool shouldConvertConstantLoadToIntImm(const APInt &Imm,
                                         Type *Ty) const override {
    return true;
  }
  SDValue lowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
};
}

#endif