Files
gem5/src/arch/riscv/decoder.hh
Roger Chang 5b41112e03 arch-riscv: Make RISC-V decodeInst overridable
The change will allow developers to implement and decode their
non-standard instructions to the CPU models

Bug: 289467440
Test: None
Change-Id: I67f4abc71596f819c1265e325784f51c8e9bb359
2023-09-22 11:38:22 +08:00

88 lines
2.9 KiB
C++

/*
* Copyright (c) 2012 Google
* Copyright (c) 2017 The University of Virginia
* 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.
*/
#ifndef __ARCH_RISCV_DECODER_HH__
#define __ARCH_RISCV_DECODER_HH__
#include "arch/generic/decode_cache.hh"
#include "arch/generic/decoder.hh"
#include "arch/riscv/insts/vector.hh"
#include "arch/riscv/types.hh"
#include "base/logging.hh"
#include "base/types.hh"
#include "cpu/static_inst.hh"
#include "debug/Decode.hh"
#include "params/RiscvDecoder.hh"
namespace gem5
{
class BaseISA;
namespace RiscvISA
{
class Decoder : public InstDecoder
{
private:
decode_cache::InstMap<ExtMachInst> instMap;
bool aligned;
bool mid;
protected:
//The extended machine instruction being generated
ExtMachInst emi;
uint32_t machInst;
virtual 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);
public:
Decoder(const RiscvDecoderParams &p);
void reset() override;
inline bool compressed(ExtMachInst inst) { return inst.quadRant < 0x3; }
//Use this to give data to the decoder. This should be used
//when there is control flow.
void moreBytes(const PCStateBase &pc, Addr fetchPC) override;
StaticInstPtr decode(PCStateBase &nextPC) override;
};
} // namespace RiscvISA
} // namespace gem5
#endif // __ARCH_RISCV_DECODER_HH__