gem5/arch/sparc/isa_traits.hh

/*
 * Copyright (c) 2003-2005 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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#ifndef __ARCH_SPARC_ISA_TRAITS_HH__
#define __ARCH_SPARC_ISA_TRAITS_HH__

#include "base/misc.hh"
#include "config/full_system.hh"
#include "sim/host.hh"

class ExecContext;
class FastCPU;
//class FullCPU;
class Checkpoint;

class StaticInst;
class StaticInstPtr;

namespace BigEndianGuest {}

#if !FULL_SYSTEM
class SyscallReturn
{
  public:
    template <class T>
    SyscallReturn(T v, bool s)
    {
        retval = (uint64_t)v;
        success = s;
    }

    template <class T>
    SyscallReturn(T v)
    {
        success = (v >= 0);
        retval = (uint64_t)v;
    }

    ~SyscallReturn() {}

    SyscallReturn& operator=(const SyscallReturn& s)
    {
        retval = s.retval;
        success = s.success;
        return *this;
    }

    bool successful() { return success; }
    uint64_t value() { return retval; }

    private:
    uint64_t retval;
    bool success;
};

#endif


namespace SparcISA
{

    // These enumerate all the registers for dependence tracking.
    enum DependenceTags {
        // 0..31 are the integer regs 0..31
        // 32..63 are the FP regs 0..31, i.e. use (reg + FP_Base_DepTag)
        FP_Base_DepTag = 32,
        Ctrl_Base_DepTag = 96,
    };

    //This makes sure the big endian versions of certain functions are used.
    using namespace BigEndianGuest;

    typedef uint32_t MachInst;
    typedef uint64_t ExtMachInst;

    inline ExtMachInst
    makeExtMI(MachInst inst, const Addr &pc) {
        return ExtMachInst(inst);
    }

    const int NumIntRegs = 32;
    const int NumFloatRegs = 64;
    const int NumMiscRegs = 32;

    // semantically meaningful register indices
    const int ZeroReg = 0;	// architecturally meaningful
    // the rest of these depend on the ABI
    const int StackPointerReg = 14;
    const int ReturnAddressReg = 31; // post call, precall is 15
    const int ReturnValueReg = 8; // Post return, 24 is pre-return.
    const int FramePointerReg = 30;
    const int ArgumentReg0 = 8;
    const int ArgumentReg1 = 9;
    const int ArgumentReg2 = 10;
    const int ArgumentReg3 = 11;
    const int ArgumentReg4 = 12;
    const int ArgumentReg5 = 13;
    const int SyscallNumReg = 1;
    // Some OS syscall sue a second register (o1) to return a second value
    const int SyscallPseudoReturnReg = ArgumentReg1;

    //XXX These numbers are bogus
    const int MaxInstSrcRegs = 3;
    const int MaxInstDestRegs = 2;

    typedef uint64_t IntReg;

    // control register file contents
    typedef uint64_t MiscReg;

    typedef double FloatReg;
    typedef uint64_t FloatRegBits;

    //8K. This value is implmentation specific; and should probably
    //be somewhere else.
    const int LogVMPageSize = 13;
    const int VMPageSize = (1 << LogVMPageSize);

    //Why does both the previous set of constants and this one exist?
    const int PageShift = 13;
    const int PageBytes = ULL(1) << PageShift;

    const int BranchPredAddrShiftAmt = 2;

    const int MachineBytes = 8;
    const int WordBytes = 4;
    const int HalfwordBytes = 2;
    const int ByteBytes = 1;

    void serialize(std::ostream & os);

    void unserialize(Checkpoint *cp, const std::string &section);

    StaticInstPtr decodeInst(ExtMachInst);

    // return a no-op instruction... used for instruction fetch faults
    extern const MachInst NoopMachInst;

    // Instruction address compression hooks
    inline Addr realPCToFetchPC(const Addr &addr)
    {
        return addr;
    }

    inline Addr fetchPCToRealPC(const Addr &addr)
    {
        return addr;
    }

    // the size of "fetched" instructions (not necessarily the size
    // of real instructions for PISA)
    inline size_t fetchInstSize()
    {
        return sizeof(MachInst);
    }

    /**
     * Function to insure ISA semantics about 0 registers.
     * @param xc The execution context.
     */
    template <class XC>
    void zeroRegisters(XC *xc);
}

#include "arch/sparc/regfile.hh"

namespace SparcISA
{

#if !FULL_SYSTEM
    static inline void setSyscallReturn(SyscallReturn return_value,
            RegFile *regs)
    {
        // check for error condition.  SPARC syscall convention is to
        // indicate success/failure in reg the carry bit of the ccr
        // and put the return value itself in the standard return value reg ().
        if (return_value.successful()) {
            // no error
            regs->miscRegs.setReg(MISCREG_CCR_ICC_C, 0);
            regs->intRegFile[ReturnValueReg] = return_value.value();
        } else {
            // got an error, return details
            regs->miscRegs.setReg(MISCREG_CCR_ICC_C, 1);
            regs->intRegFile[ReturnValueReg] = -return_value.value();
        }
    }
#endif
};

#endif // __ARCH_SPARC_ISA_TRAITS_HH__