TCEISelLowering.hh

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/*
    Copyright (c) 2002-2009 Tampere University.
 
    This file is part of TTA-Based Codesign Environment (TCE).
 
    Permission is hereby granted, free of charge, to any person obtaining a
    copy of this software and associated documentation files (the "Software"),
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    the rights to use, copy, modify, merge, publish, distribute, sublicense,
    and/or sell copies of the Software, and to permit persons to whom the
    Software is furnished to do so, subject to the following conditions:
 
    The above copyright notice and this permission notice shall be included in
    all copies or substantial portions of the Software.
 
    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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/**
 * @file TCETargetLowering.h
 *
 * Declaration of TCETargetLowering class.
 *
 * @author Veli-Pekka J��skel�inen 2007 (vjaaskel-no.spam-cs.tut.fi)
 * @author Mikael Lepist� 2009 (mikael.lepisto-no.spam-tut.fi)
 */
 
#ifndef TCE_TARGET_LOWERING_H
#define TCE_TARGET_LOWERING_H
 
#include <llvm/CodeGen/TargetLowering.h>
#include "TCEPlugin.hh"
#include "TCESubtarget.hh"
#include "tce_config.h"
#include "TCEString.hh"
#include <map>
#include <iostream>
 
namespace TCEISD {
    enum {
        FIRST_NUMBER = llvm::ISD::BUILTIN_OP_END,
        SELECT_I1,
        SELECT_I8,
        SELECT_I16,
        SELECT_I32,
        SELECT_I64,
        SELECT_F16,
        SELECT_F32,
        SELECT_F64,
 
        CONST_POOL,
        GLOBAL_ADDR,
        BLOCK_ADDR,
 
        Hi, Lo,      // Hi/Lo operations, typically on a global address.
 
        FTOI,        // FP to Int within a FP register.
        ITOF,        // Int to FP within a FP register.
 
        CALL,        // A call instruction.
        RET_FLAG ,    // Return with a flag operand.
        RET_FLAG_old,
        SRA_Const,
        SRL_Const,
        SHL_Const
   };
}
 
namespace llvm {
 
#define SDLOC_PARAM_TYPE const SDLoc&
 
    class TCETargetMachine;
 
    /**
     *  Lowers LLVM code to SelectionDAG for the TCE backend.
     */
    class TCETargetLowering : public llvm::TargetLowering {
        mutable int VarArgsFrameOffset;   // Frame offset to start of varargs area.
    public:
        TCETargetLowering(TargetMachine &TM, const TCESubtarget &subt);
 
        virtual SDValue LowerOperation(SDValue Op, SelectionDAG &DAG) const override;
        virtual SDValue PerformDAGCombine(
            SDNode *N, DAGCombinerInfo &DCI) const override;
 
        int getVarArgsFrameOffset() const /* override */ { return VarArgsFrameOffset; }
 
       virtual const char* getTargetNodeName(unsigned opcode) const override;
 
        ConstraintType getConstraintType(StringRef Constraint) const override;
        std::pair<unsigned, const TargetRegisterClass *>
        getRegForInlineAsmConstraint(const TargetRegisterInfo *TRI,
                                     StringRef Constraint, MVT VT) const override;
 
        void LowerAsmOperandForConstraint(
            SDValue Op,
            std::string& Constraint,
            std::vector<SDValue>& Ops,
            SelectionDAG& DAG) const override;
 
        //TODO: this is from some old version - which?
        std::vector<unsigned>
        getRegClassForInlineAsmConstraint(const std::string &Constraint,
                                          EVT VT) const;
        virtual bool isOffsetFoldingLegal(const GlobalAddressSDNode *GA) const override;
        
        /// getFunctionAlignment - Return the Log2 alignment of this function.
 
        virtual SDValue
        LowerFormalArguments(SDValue Chain,
                             CallingConv::ID CallConv,
                             bool isVarArg,
                             const SmallVectorImpl<ISD::InputArg> &Ins,
                             SDLOC_PARAM_TYPE dl, SelectionDAG &DAG,
                             SmallVectorImpl<SDValue> &InVals) const override;
 
        SDValue LowerTRAP(SDValue Op, SelectionDAG &DAG) const;
        SDValue LowerVASTART(SDValue Op, SelectionDAG &DAG) const;
        SDValue LowerBlockAddress(SDValue Op, SelectionDAG &DAG) const;
        SDValue LowerConstant(SDValue Op, SelectionDAG &DAG) const;
        SDValue LowerBuildVector(SDValue Op, SelectionDAG &DAG) const;
        SDValue LowerINLINEASM(SDValue Op, SelectionDAG &DAG) const;
        SDValue LowerShift(SDValue op, SelectionDAG& dag) const;
        SDValue LowerBuildBooleanVectorVector(
            SDValue Op, MVT newElementVT, int elemCount, SelectionDAG &DAG) const;
        SDValue lowerHWLoops(SDValue op, SelectionDAG &dag) const;
        SDValue lowerFABS(SDValue op, SelectionDAG &dag) const;
 
        SDValue lowerExtOrBoolLoad(SDValue op, SelectionDAG& DAG) const;
 
        std::pair<int, TCEString> getConstShiftNodeAndTCEOP(SDValue op) const;
 
        virtual SDValue
        LowerCall(TargetLowering::CallLoweringInfo &CLI,
                  SmallVectorImpl<SDValue> &InVals) const override;
        
        virtual SDValue
        LowerReturn(SDValue Chain,
                    CallingConv::ID CallConv, bool isVarArg,
                    const SmallVectorImpl<ISD::OutputArg> &Outs,
                    const SmallVectorImpl<SDValue> &OutVals,
                    SDLOC_PARAM_TYPE dl, SelectionDAG &DAG) const override;
 
        bool isConstantOrUndefBuild(const SDNode& node) const;
        bool canEncodeConstantOperands(const SDNode& node) const;
        bool canEncodeImmediate(const ConstantSDNode& node) const;
 
        bool shouldLoadFromConstantPool(unsigned addressSpace) const;
 
//        virtual bool allowsMisalignedMemoryAccesses(EVT VT, unsigned as, unsigned align, MachineMemOperand::Flags flags, bool* ) const override;
        // We can ignore the bitwidth differences between the pointers
        // for now. It's the programmer's responsibility to ensure they
        // fit.
        // ----------------------------------------------------
        //
        //  Below here TCE specific stuff is added, which is not copied from Sparc
        //
        // ----------------------------------------------------
 
        SDValue LowerGLOBALADDRESS(SDValue Op, SelectionDAG &DAG) const;
 
        static bool isBroadcast(SDNode *n);
 
    private:
 
        bool hasI1RegisterClass() const;
 
        /// Tells if the target machine has boolean register file.
        bool hasI1RC_ = false;
 
        TCETargetMachine& tm_;
 
        /// Predicates to tell whenever the addresses belonging to a address
        /// space should be loaded from constant pool instead of immediates.
        /// Address space as index maps to the predicate.
        std::map<unsigned, bool> loadGAFromConstantPool_;
 
        const TargetRegisterClass*
        getVectorRegClassForInlineAsmConstraint(
            const TargetRegisterInfo* TRI, MVT VT) const;
 
        /// Implementation generated to Backend.inc from TDGenSIMD.cc.
        void addVectorRegisterClasses();
 
        /// Implementation generated to Backend.inc from TDGenSIMD.cc.
        std::pair<unsigned, const TargetRegisterClass *>
        associatedVectorRegClass(const EVT &vt) const;
 
        /// Implementation generated to Backend.inc from TDGenSIMD.cc.
        virtual llvm::EVT getSetCCResultVT(const EVT &VT) const;
 
        /// Implementation generated to Backend.inc from TDGenSIMD.cc.
        void addVectorLowerings();
 
    public:
        llvm::EVT getSetCCResultType(
            const DataLayout &DL, LLVMContext &Context,
            EVT VT) const override;
 
        virtual bool isFPImmLegal(
            const APFloat& apf, EVT VT, bool forCodeSize) const override;
 
    SDValue ExpandLibCall(
        RTLIB::Libcall LC, SDNode *Node, bool isSigned, SelectionDAG &DAG)
        const;
 
        void ReplaceNodeResults(SDNode * node,
                                SmallVectorImpl< SDValue > &,
                                SelectionDAG &) const override;
 
    };
}
 
#endif