//===-- NVPTXISelLowering.h - NVPTX 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 NVPTX uses to lower LLVM code into a
// selection DAG.
//
//===----------------------------------------------------------------------===//

#ifndef NVPTXISELLOWERING_H
#define NVPTXISELLOWERING_H

#include "NVPTX.h"
#include "NVPTXSubtarget.h"
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/Target/TargetLowering.h"

namespace llvm {
namespace NVPTXISD {
enum NodeType {
  // Start the numbering from where ISD NodeType finishes.
  FIRST_NUMBER = ISD::BUILTIN_OP_END,
  Wrapper,
  CALL,
  RET_FLAG,
  LOAD_PARAM,
  DeclareParam,
  DeclareScalarParam,
  DeclareRetParam,
  DeclareRet,
  DeclareScalarRet,
  PrintCall,
  PrintCallUni,
  CallArgBegin,
  CallArg,
  LastCallArg,
  CallArgEnd,
  CallVoid,
  CallVal,
  CallSymbol,
  Prototype,
  MoveParam,
  PseudoUseParam,
  RETURN,
  CallSeqBegin,
  CallSeqEnd,
  CallPrototype,
  Dummy,

  LoadV2 = ISD::FIRST_TARGET_MEMORY_OPCODE,
  LoadV4,
  LDGV2, // LDG.v2
  LDGV4, // LDG.v4
  LDUV2, // LDU.v2
  LDUV4, // LDU.v4
  StoreV2,
  StoreV4,
  LoadParam,
  LoadParamV2,
  LoadParamV4,
  StoreParam,
  StoreParamV2,
  StoreParamV4,
  StoreParamS32, // to sext and store a <32bit value, not used currently
  StoreParamU32, // to zext and store a <32bit value, not used currently 
  StoreRetval,
  StoreRetvalV2,
  StoreRetvalV4
};
}

//===--------------------------------------------------------------------===//
// TargetLowering Implementation
//===--------------------------------------------------------------------===//
class NVPTXTargetLowering : public TargetLowering {
public:
  explicit NVPTXTargetLowering(NVPTXTargetMachine &TM);
  virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const;

  SDValue LowerGlobalAddress(SDValue Op, SelectionDAG &DAG) const;
  SDValue LowerGlobalAddress(const GlobalValue *GV, int64_t Offset,
                             SelectionDAG &DAG) const;

  virtual const char *getTargetNodeName(unsigned Opcode) const;

  bool isTypeSupportedInIntrinsic(MVT VT) const;

  bool getTgtMemIntrinsic(IntrinsicInfo &Info, const CallInst &I,
                          unsigned Intrinsic) const;

  /// isLegalAddressingMode - Return true if the addressing mode represented
  /// by AM is legal for this target, for a load/store of the specified type
  /// Used to guide target specific optimizations, like loop strength
  /// reduction (LoopStrengthReduce.cpp) and memory optimization for
  /// address mode (CodeGenPrepare.cpp)
  virtual bool isLegalAddressingMode(const AddrMode &AM, Type *Ty) const;

  /// getFunctionAlignment - Return the Log2 alignment of this function.
  virtual unsigned getFunctionAlignment(const Function *F) const;

  virtual EVT getSetCCResultType(LLVMContext &, EVT VT) const {
    if (VT.isVector())
      return MVT::getVectorVT(MVT::i1, VT.getVectorNumElements());
    return MVT::i1;
  }

  ConstraintType getConstraintType(const std::string &Constraint) const;
  std::pair<unsigned, const TargetRegisterClass *>
  getRegForInlineAsmConstraint(const std::string &Constraint, MVT VT) const;

  virtual SDValue LowerFormalArguments(
      SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
      const SmallVectorImpl<ISD::InputArg> &Ins, SDLoc dl, SelectionDAG &DAG,
      SmallVectorImpl<SDValue> &InVals) const;

  virtual SDValue
  LowerCall(CallLoweringInfo &CLI, SmallVectorImpl<SDValue> &InVals) const;

  std::string getPrototype(Type *, const ArgListTy &,
                           const SmallVectorImpl<ISD::OutputArg> &,
                           unsigned retAlignment,
                           const ImmutableCallSite *CS) const;

  virtual SDValue
  LowerReturn(SDValue Chain, CallingConv::ID CallConv, bool isVarArg,
              const SmallVectorImpl<ISD::OutputArg> &Outs,
              const SmallVectorImpl<SDValue> &OutVals, SDLoc dl,
              SelectionDAG &DAG) const;

  virtual void LowerAsmOperandForConstraint(SDValue Op, std::string &Constraint,
                                            std::vector<SDValue> &Ops,
                                            SelectionDAG &DAG) const;

  NVPTXTargetMachine *nvTM;

  // PTX always uses 32-bit shift amounts
  virtual MVT getScalarShiftAmountTy(EVT LHSTy) const { return MVT::i32; }

  virtual bool shouldSplitVectorElementType(EVT VT) const;

private:
  const NVPTXSubtarget &nvptxSubtarget; // cache the subtarget here

  SDValue getExtSymb(SelectionDAG &DAG, const char *name, int idx,
                     EVT = MVT::i32) const;
  SDValue getParamSymbol(SelectionDAG &DAG, int idx, EVT) const;
  SDValue getParamHelpSymbol(SelectionDAG &DAG, int idx);

  SDValue LowerCONCAT_VECTORS(SDValue Op, SelectionDAG &DAG) const;

  SDValue LowerLOAD(SDValue Op, SelectionDAG &DAG) const;
  SDValue LowerLOADi1(SDValue Op, SelectionDAG &DAG) const;

  SDValue LowerSTORE(SDValue Op, SelectionDAG &DAG) const;
  SDValue LowerSTOREi1(SDValue Op, SelectionDAG &DAG) const;
  SDValue LowerSTOREVector(SDValue Op, SelectionDAG &DAG) const;

  virtual void ReplaceNodeResults(SDNode *N, SmallVectorImpl<SDValue> &Results,
                                  SelectionDAG &DAG) const;

  unsigned getArgumentAlignment(SDValue Callee, const ImmutableCallSite *CS,
                                Type *Ty, unsigned Idx) const;
};
} // namespace llvm

#endif // NVPTXISELLOWERING_H