gem5/src/arch/mips/predecoder.hh
Ali Saidi a679cd917a ARM: Cleanup implementation of ITSTATE and put important code in PCState.
Consolidate all code to handle ITSTATE in the PCState object rather than
touching a variety of structures/objects.
2011-04-04 11:42:28 -05:00

110 lines
2.8 KiB
C++

/*
* Copyright (c) 2006 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
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* 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,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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*
* Authors: Gabe Black
*/
#ifndef __ARCH_MIPS_PREDECODER_HH__
#define __ARCH_MIPS_PREDECODER_HH__
#include "arch/mips/types.hh"
#include "base/misc.hh"
#include "base/types.hh"
class ThreadContext;
namespace MipsISA
{
class Predecoder
{
protected:
ThreadContext * tc;
//The extended machine instruction being generated
ExtMachInst emi;
bool emiIsReady;
public:
Predecoder(ThreadContext * _tc) : tc(_tc), emiIsReady(false)
{}
ThreadContext *getTC()
{
return tc;
}
void
setTC(ThreadContext *_tc)
{
tc = _tc;
}
void
process()
{
}
void
reset()
{
emiIsReady = false;
}
//Use this to give data to the predecoder. This should be used
//when there is control flow.
void
moreBytes(const PCState &pc, Addr fetchPC, MachInst inst)
{
emi = inst;
emiIsReady = true;
}
bool
needMoreBytes()
{
return true;
}
bool
extMachInstReady()
{
return emiIsReady;
}
//This returns a constant reference to the ExtMachInst to avoid a copy
const ExtMachInst &
getExtMachInst(PCState &pc)
{
emiIsReady = false;
return emi;
}
};
};
#endif // __ARCH_MIPS_PREDECODER_HH__