decoder.hh

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/*
 * Copyright (c) 2012 Google
 * Copyright (c) 2021 IBM Corporation
 * 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
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 * this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef __ARCH_POWER_DECODER_HH__
#define __ARCH_POWER_DECODER_HH__
 
#include "arch/generic/decode_cache.hh"
#include "arch/generic/decoder.hh"
#include "arch/power/types.hh"
#include "cpu/static_inst.hh"
#include "debug/Decode.hh"
#include "params/PowerDecoder.hh"
 
namespace gem5
{
 
namespace PowerISA
{
 
class ISA;
class Decoder : public InstDecoder
{
  protected:
    // The extended machine instruction being generated
    ExtMachInst emi;
 
  public:
    Decoder(const PowerDecoderParams &p) : InstDecoder(p, &emi) {}
 
    // Use this to give data to the predecoder. This should be used
    // when there is control flow.
    void
    moreBytes(const PCStateBase &pc, Addr fetchPC) override
    {
        emi = gtoh(emi, pc.as<PCState>().byteOrder());
        instDone = true;
    }
 
  protected:
    static GenericISA::BasicDecodeCache<Decoder, ExtMachInst> defaultCache;
    friend class GenericISA::BasicDecodeCache<Decoder, ExtMachInst>;
 
    StaticInstPtr decodeInst(ExtMachInst mach_inst);
 
    StaticInstPtr
    decode(ExtMachInst mach_inst, Addr addr)
    {
        StaticInstPtr si = defaultCache.decode(this, mach_inst, addr);
        DPRINTF(Decode, "Decode: Decoded %s instruction: %#x\n",
                si->getName(), mach_inst);
        return si;
    }
 
  public:
    StaticInstPtr
    decode(PCStateBase &next_pc) override
    {
        if (!instDone)
            return NULL;
        instDone = false;
        return decode(emi, next_pc.instAddr());
    }
};
 
} // namespace PowerISA
} // namespace gem5
 
#endif // __ARCH_POWER_DECODER_HH__