decoder.hh revision 12120:133620bfc43b
1/* 2 * Copyright (c) 2012 Google 3 * Copyright (c) 2017 The University of Virginia 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are 8 * met: redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer; 10 * redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution; 13 * neither the name of the copyright holders nor the names of its 14 * contributors may be used to endorse or promote products derived from 15 * this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * Authors: Gabe Black 30 * Alec Roelke 31 */ 32 33#ifndef __ARCH_RISCV_DECODER_HH__ 34#define __ARCH_RISCV_DECODER_HH__ 35 36#include "arch/generic/decode_cache.hh" 37#include "arch/riscv/isa_traits.hh" 38#include "arch/riscv/types.hh" 39#include "base/misc.hh" 40#include "base/types.hh" 41#include "cpu/static_inst.hh" 42#include "debug/Decode.hh" 43 44namespace RiscvISA 45{ 46 47class ISA; 48class Decoder 49{ 50 private: 51 DecodeCache::InstMap instMap; 52 bool mid; 53 54 protected: 55 //The extended machine instruction being generated 56 ExtMachInst emi; 57 bool instDone; 58 59 public: 60 Decoder(ISA* isa=nullptr) 61 : mid(false), emi(NoopMachInst), instDone(false) 62 {} 63 64 void process() {} 65 void reset() { instDone = false; } 66 67 //Use this to give data to the decoder. This should be used 68 //when there is control flow. 69 void moreBytes(const PCState &pc, Addr fetchPC, MachInst inst); 70 71 bool needMoreBytes() { return true; } 72 bool instReady() { return instDone; } 73 void takeOverFrom(Decoder *old) {} 74 75 StaticInstPtr decodeInst(ExtMachInst mach_inst); 76 77 /// Decode a machine instruction. 78 /// @param mach_inst The binary instruction to decode. 79 /// @retval A pointer to the corresponding StaticInst object. 80 StaticInstPtr decode(ExtMachInst mach_inst, Addr addr); 81 82 StaticInstPtr decode(RiscvISA::PCState &nextPC); 83}; 84 85} // namespace RiscvISA 86 87#endif // __ARCH_RISCV_DECODER_HH__ 88