Files
gem5/src/arch/mips/decoder.hh
Nilay Vaish fc57ae6401 x86, cpu: corrects 270c9a75e91f, take over decoder on cpu switch
The changes made by the changeset 270c9a75e91f do not work well with switching
of cpus. The problem is that decoder for the old thread context holds state
that is not taken over by the new decoder.

This patch adds a takeOverFrom() function to Decoder class in each ISA. Except
for x86, functions in other ISAs are blank. For x86, the function copies state
from the old decoder to the new decoder.
2013-01-22 00:10:10 -06:00

117 lines
3.1 KiB
C++

/*
* Copyright (c) 2012 Google
* 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,
* 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
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Authors: Gabe Black
*/
#ifndef __ARCH_MIPS_DECODER_HH__
#define __ARCH_MIPS_DECODER_HH__
#include "arch/generic/decode_cache.hh"
#include "arch/mips/types.hh"
#include "base/misc.hh"
#include "base/types.hh"
#include "cpu/static_inst.hh"
namespace MipsISA
{
class Decoder
{
protected:
//The extended machine instruction being generated
ExtMachInst emi;
bool instDone;
public:
Decoder() : instDone(false)
{}
void
process()
{
}
void
reset()
{
instDone = false;
}
//Use this to give data to the decoder. This should be used
//when there is control flow.
void
moreBytes(const PCState &pc, Addr fetchPC, MachInst inst)
{
emi = inst;
instDone = true;
}
bool
needMoreBytes()
{
return true;
}
bool
instReady()
{
return instDone;
}
void takeOverFrom(Decoder *old) {}
protected:
/// A cache of decoded instruction objects.
static GenericISA::BasicDecodeCache defaultCache;
public:
StaticInstPtr decodeInst(ExtMachInst mach_inst);
/// Decode a machine instruction.
/// @param mach_inst The binary instruction to decode.
/// @retval A pointer to the corresponding StaticInst object.
StaticInstPtr
decode(ExtMachInst mach_inst, Addr addr)
{
return defaultCache.decode(this, mach_inst, addr);
}
StaticInstPtr
decode(MipsISA::PCState &nextPC)
{
if (!instDone)
return NULL;
instDone = false;
return decode(emi, nextPC.instAddr());
}
};
} // namespace MipsISA
#endif // __ARCH_MIPS_DECODER_HH__