decoder.hh revision 9478
19020Sgblack@eecs.umich.edu/* 29020Sgblack@eecs.umich.edu * Copyright (c) 2012 Google 39020Sgblack@eecs.umich.edu * All rights reserved. 49020Sgblack@eecs.umich.edu * 59020Sgblack@eecs.umich.edu * Redistribution and use in source and binary forms, with or without 69020Sgblack@eecs.umich.edu * modification, are permitted provided that the following conditions are 79020Sgblack@eecs.umich.edu * met: redistributions of source code must retain the above copyright 89020Sgblack@eecs.umich.edu * notice, this list of conditions and the following disclaimer; 99020Sgblack@eecs.umich.edu * redistributions in binary form must reproduce the above copyright 109020Sgblack@eecs.umich.edu * notice, this list of conditions and the following disclaimer in the 119020Sgblack@eecs.umich.edu * documentation and/or other materials provided with the distribution; 129020Sgblack@eecs.umich.edu * neither the name of the copyright holders nor the names of its 139020Sgblack@eecs.umich.edu * contributors may be used to endorse or promote products derived from 149020Sgblack@eecs.umich.edu * this software without specific prior written permission. 159020Sgblack@eecs.umich.edu * 169020Sgblack@eecs.umich.edu * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 179020Sgblack@eecs.umich.edu * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 189020Sgblack@eecs.umich.edu * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 199020Sgblack@eecs.umich.edu * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 209020Sgblack@eecs.umich.edu * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 219020Sgblack@eecs.umich.edu * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 229020Sgblack@eecs.umich.edu * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 239020Sgblack@eecs.umich.edu * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 249020Sgblack@eecs.umich.edu * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 259020Sgblack@eecs.umich.edu * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 269020Sgblack@eecs.umich.edu * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 279020Sgblack@eecs.umich.edu * 289020Sgblack@eecs.umich.edu * Authors: Gabe Black 299020Sgblack@eecs.umich.edu */ 309020Sgblack@eecs.umich.edu 319020Sgblack@eecs.umich.edu#ifndef __ARCH_X86_DECODER_HH__ 329020Sgblack@eecs.umich.edu#define __ARCH_X86_DECODER_HH__ 339020Sgblack@eecs.umich.edu 349023Sgblack@eecs.umich.edu#include <cassert> 359376Sgblack@eecs.umich.edu#include <vector> 369023Sgblack@eecs.umich.edu 379023Sgblack@eecs.umich.edu#include "arch/x86/regs/misc.hh" 389023Sgblack@eecs.umich.edu#include "arch/x86/types.hh" 399023Sgblack@eecs.umich.edu#include "base/bitfield.hh" 409023Sgblack@eecs.umich.edu#include "base/misc.hh" 419023Sgblack@eecs.umich.edu#include "base/trace.hh" 429023Sgblack@eecs.umich.edu#include "base/types.hh" 439022Sgblack@eecs.umich.edu#include "cpu/decode_cache.hh" 449024Sgblack@eecs.umich.edu#include "cpu/static_inst.hh" 459023Sgblack@eecs.umich.edu#include "debug/Decoder.hh" 469023Sgblack@eecs.umich.edu 479020Sgblack@eecs.umich.edunamespace X86ISA 489020Sgblack@eecs.umich.edu{ 499020Sgblack@eecs.umich.edu 509022Sgblack@eecs.umich.educlass Decoder 519022Sgblack@eecs.umich.edu{ 529023Sgblack@eecs.umich.edu private: 539023Sgblack@eecs.umich.edu //These are defined and documented in decoder_tables.cc 549023Sgblack@eecs.umich.edu static const uint8_t Prefixes[256]; 559023Sgblack@eecs.umich.edu static const uint8_t UsesModRM[2][256]; 569023Sgblack@eecs.umich.edu static const uint8_t ImmediateType[2][256]; 579023Sgblack@eecs.umich.edu static const uint8_t SizeTypeToSize[3][10]; 589023Sgblack@eecs.umich.edu 599023Sgblack@eecs.umich.edu protected: 609376Sgblack@eecs.umich.edu struct InstBytes 619376Sgblack@eecs.umich.edu { 629376Sgblack@eecs.umich.edu StaticInstPtr si; 639376Sgblack@eecs.umich.edu std::vector<MachInst> chunks; 649376Sgblack@eecs.umich.edu std::vector<MachInst> masks; 659376Sgblack@eecs.umich.edu int lastOffset; 669376Sgblack@eecs.umich.edu 679376Sgblack@eecs.umich.edu InstBytes() : lastOffset(0) 689376Sgblack@eecs.umich.edu {} 699376Sgblack@eecs.umich.edu }; 709376Sgblack@eecs.umich.edu 719376Sgblack@eecs.umich.edu static InstBytes dummy; 729376Sgblack@eecs.umich.edu 739023Sgblack@eecs.umich.edu //The bytes to be predecoded 749023Sgblack@eecs.umich.edu MachInst fetchChunk; 759376Sgblack@eecs.umich.edu InstBytes *instBytes; 769376Sgblack@eecs.umich.edu int chunkIdx; 779023Sgblack@eecs.umich.edu //The pc of the start of fetchChunk 789023Sgblack@eecs.umich.edu Addr basePC; 799023Sgblack@eecs.umich.edu //The pc the current instruction started at 809023Sgblack@eecs.umich.edu Addr origPC; 819023Sgblack@eecs.umich.edu //The offset into fetchChunk of current processing 829023Sgblack@eecs.umich.edu int offset; 839023Sgblack@eecs.umich.edu //The extended machine instruction being generated 849023Sgblack@eecs.umich.edu ExtMachInst emi; 859376Sgblack@eecs.umich.edu //Predecoding state 869376Sgblack@eecs.umich.edu X86Mode mode; 879376Sgblack@eecs.umich.edu X86SubMode submode; 889376Sgblack@eecs.umich.edu uint8_t altOp; 899376Sgblack@eecs.umich.edu uint8_t defOp; 909376Sgblack@eecs.umich.edu uint8_t altAddr; 919376Sgblack@eecs.umich.edu uint8_t defAddr; 929376Sgblack@eecs.umich.edu uint8_t stack; 939023Sgblack@eecs.umich.edu 949376Sgblack@eecs.umich.edu uint8_t getNextByte() 959023Sgblack@eecs.umich.edu { 969023Sgblack@eecs.umich.edu return ((uint8_t *)&fetchChunk)[offset]; 979023Sgblack@eecs.umich.edu } 989023Sgblack@eecs.umich.edu 999023Sgblack@eecs.umich.edu void getImmediate(int &collected, uint64_t ¤t, int size) 1009023Sgblack@eecs.umich.edu { 1019023Sgblack@eecs.umich.edu //Figure out how many bytes we still need to get for the 1029023Sgblack@eecs.umich.edu //immediate. 1039023Sgblack@eecs.umich.edu int toGet = size - collected; 1049023Sgblack@eecs.umich.edu //Figure out how many bytes are left in our "buffer" 1059023Sgblack@eecs.umich.edu int remaining = sizeof(MachInst) - offset; 1069023Sgblack@eecs.umich.edu //Get as much as we need, up to the amount available. 1079023Sgblack@eecs.umich.edu toGet = toGet > remaining ? remaining : toGet; 1089023Sgblack@eecs.umich.edu 1099023Sgblack@eecs.umich.edu //Shift the bytes we want to be all the way to the right 1109023Sgblack@eecs.umich.edu uint64_t partialImm = fetchChunk >> (offset * 8); 1119023Sgblack@eecs.umich.edu //Mask off what we don't want 1129023Sgblack@eecs.umich.edu partialImm &= mask(toGet * 8); 1139023Sgblack@eecs.umich.edu //Shift it over to overlay with our displacement. 1149023Sgblack@eecs.umich.edu partialImm <<= (immediateCollected * 8); 1159023Sgblack@eecs.umich.edu //Put it into our displacement 1169023Sgblack@eecs.umich.edu current |= partialImm; 1179023Sgblack@eecs.umich.edu //Update how many bytes we've collected. 1189023Sgblack@eecs.umich.edu collected += toGet; 1199023Sgblack@eecs.umich.edu consumeBytes(toGet); 1209023Sgblack@eecs.umich.edu } 1219023Sgblack@eecs.umich.edu 1229376Sgblack@eecs.umich.edu void updateOffsetState() 1239376Sgblack@eecs.umich.edu { 1249376Sgblack@eecs.umich.edu assert(offset <= sizeof(MachInst)); 1259376Sgblack@eecs.umich.edu if (offset == sizeof(MachInst)) { 1269376Sgblack@eecs.umich.edu DPRINTF(Decoder, "At the end of a chunk, idx = %d, chunks = %d.\n", 1279376Sgblack@eecs.umich.edu chunkIdx, instBytes->chunks.size()); 1289376Sgblack@eecs.umich.edu chunkIdx++; 1299376Sgblack@eecs.umich.edu if (chunkIdx == instBytes->chunks.size()) { 1309376Sgblack@eecs.umich.edu outOfBytes = true; 1319376Sgblack@eecs.umich.edu } else { 1329376Sgblack@eecs.umich.edu offset = 0; 1339376Sgblack@eecs.umich.edu fetchChunk = instBytes->chunks[chunkIdx]; 1349376Sgblack@eecs.umich.edu basePC += sizeof(MachInst); 1359376Sgblack@eecs.umich.edu } 1369376Sgblack@eecs.umich.edu } 1379376Sgblack@eecs.umich.edu } 1389376Sgblack@eecs.umich.edu 1399376Sgblack@eecs.umich.edu void consumeByte() 1409023Sgblack@eecs.umich.edu { 1419023Sgblack@eecs.umich.edu offset++; 1429376Sgblack@eecs.umich.edu updateOffsetState(); 1439023Sgblack@eecs.umich.edu } 1449023Sgblack@eecs.umich.edu 1459376Sgblack@eecs.umich.edu void consumeBytes(int numBytes) 1469023Sgblack@eecs.umich.edu { 1479023Sgblack@eecs.umich.edu offset += numBytes; 1489376Sgblack@eecs.umich.edu updateOffsetState(); 1499023Sgblack@eecs.umich.edu } 1509023Sgblack@eecs.umich.edu 1519023Sgblack@eecs.umich.edu //State machine state 1529023Sgblack@eecs.umich.edu protected: 1539023Sgblack@eecs.umich.edu //Whether or not we're out of bytes 1549023Sgblack@eecs.umich.edu bool outOfBytes; 1559023Sgblack@eecs.umich.edu //Whether we've completed generating an ExtMachInst 1569023Sgblack@eecs.umich.edu bool instDone; 1579023Sgblack@eecs.umich.edu //The size of the displacement value 1589023Sgblack@eecs.umich.edu int displacementSize; 1599023Sgblack@eecs.umich.edu //The size of the immediate value 1609023Sgblack@eecs.umich.edu int immediateSize; 1619023Sgblack@eecs.umich.edu //This is how much of any immediate value we've gotten. This is used 1629023Sgblack@eecs.umich.edu //for both the actual immediate and the displacement. 1639023Sgblack@eecs.umich.edu int immediateCollected; 1649023Sgblack@eecs.umich.edu 1659023Sgblack@eecs.umich.edu enum State { 1669023Sgblack@eecs.umich.edu ResetState, 1679376Sgblack@eecs.umich.edu FromCacheState, 1689023Sgblack@eecs.umich.edu PrefixState, 1699023Sgblack@eecs.umich.edu OpcodeState, 1709023Sgblack@eecs.umich.edu ModRMState, 1719023Sgblack@eecs.umich.edu SIBState, 1729023Sgblack@eecs.umich.edu DisplacementState, 1739023Sgblack@eecs.umich.edu ImmediateState, 1749023Sgblack@eecs.umich.edu //We should never get to this state. Getting here is an error. 1759023Sgblack@eecs.umich.edu ErrorState 1769023Sgblack@eecs.umich.edu }; 1779023Sgblack@eecs.umich.edu 1789023Sgblack@eecs.umich.edu State state; 1799023Sgblack@eecs.umich.edu 1809023Sgblack@eecs.umich.edu //Functions to handle each of the states 1819376Sgblack@eecs.umich.edu State doResetState(); 1829376Sgblack@eecs.umich.edu State doFromCacheState(); 1839023Sgblack@eecs.umich.edu State doPrefixState(uint8_t); 1849023Sgblack@eecs.umich.edu State doOpcodeState(uint8_t); 1859023Sgblack@eecs.umich.edu State doModRMState(uint8_t); 1869023Sgblack@eecs.umich.edu State doSIBState(uint8_t); 1879023Sgblack@eecs.umich.edu State doDisplacementState(); 1889023Sgblack@eecs.umich.edu State doImmediateState(); 1899023Sgblack@eecs.umich.edu 1909376Sgblack@eecs.umich.edu protected: 1919376Sgblack@eecs.umich.edu /// Caching for decoded instruction objects. 1929376Sgblack@eecs.umich.edu 1939376Sgblack@eecs.umich.edu typedef MiscReg CacheKey; 1949376Sgblack@eecs.umich.edu 1959376Sgblack@eecs.umich.edu typedef DecodeCache::AddrMap<Decoder::InstBytes> DecodePages; 1969376Sgblack@eecs.umich.edu DecodePages *decodePages; 1979376Sgblack@eecs.umich.edu typedef m5::hash_map<CacheKey, DecodePages *> AddrCacheMap; 1989376Sgblack@eecs.umich.edu AddrCacheMap addrCacheMap; 1999376Sgblack@eecs.umich.edu 2009376Sgblack@eecs.umich.edu DecodeCache::InstMap *instMap; 2019376Sgblack@eecs.umich.edu typedef m5::hash_map<CacheKey, DecodeCache::InstMap *> InstCacheMap; 2029376Sgblack@eecs.umich.edu static InstCacheMap instCacheMap; 2039376Sgblack@eecs.umich.edu 2049023Sgblack@eecs.umich.edu public: 2059377Sgblack@eecs.umich.edu Decoder() : basePC(0), origPC(0), offset(0), 2069023Sgblack@eecs.umich.edu outOfBytes(true), instDone(false), 2079023Sgblack@eecs.umich.edu state(ResetState) 2089023Sgblack@eecs.umich.edu { 2099037Sgblack@eecs.umich.edu memset(&emi, 0, sizeof(emi)); 2109376Sgblack@eecs.umich.edu mode = LongMode; 2119376Sgblack@eecs.umich.edu submode = SixtyFourBitMode; 2129376Sgblack@eecs.umich.edu emi.mode.mode = mode; 2139376Sgblack@eecs.umich.edu emi.mode.submode = submode; 2149376Sgblack@eecs.umich.edu altOp = 0; 2159376Sgblack@eecs.umich.edu defOp = 0; 2169376Sgblack@eecs.umich.edu altAddr = 0; 2179376Sgblack@eecs.umich.edu defAddr = 0; 2189376Sgblack@eecs.umich.edu stack = 0; 2199376Sgblack@eecs.umich.edu instBytes = &dummy; 2209376Sgblack@eecs.umich.edu decodePages = NULL; 2219376Sgblack@eecs.umich.edu instMap = NULL; 2229376Sgblack@eecs.umich.edu } 2239376Sgblack@eecs.umich.edu 2249376Sgblack@eecs.umich.edu void setM5Reg(HandyM5Reg m5Reg) 2259376Sgblack@eecs.umich.edu { 2269376Sgblack@eecs.umich.edu mode = (X86Mode)(uint64_t)m5Reg.mode; 2279376Sgblack@eecs.umich.edu submode = (X86SubMode)(uint64_t)m5Reg.submode; 2289376Sgblack@eecs.umich.edu emi.mode.mode = mode; 2299376Sgblack@eecs.umich.edu emi.mode.submode = submode; 2309376Sgblack@eecs.umich.edu altOp = m5Reg.altOp; 2319376Sgblack@eecs.umich.edu defOp = m5Reg.defOp; 2329376Sgblack@eecs.umich.edu altAddr = m5Reg.altAddr; 2339376Sgblack@eecs.umich.edu defAddr = m5Reg.defAddr; 2349376Sgblack@eecs.umich.edu stack = m5Reg.stack; 2359376Sgblack@eecs.umich.edu 2369376Sgblack@eecs.umich.edu AddrCacheMap::iterator amIter = addrCacheMap.find(m5Reg); 2379376Sgblack@eecs.umich.edu if (amIter != addrCacheMap.end()) { 2389376Sgblack@eecs.umich.edu decodePages = amIter->second; 2399376Sgblack@eecs.umich.edu } else { 2409376Sgblack@eecs.umich.edu decodePages = new DecodePages; 2419376Sgblack@eecs.umich.edu addrCacheMap[m5Reg] = decodePages; 2429376Sgblack@eecs.umich.edu } 2439376Sgblack@eecs.umich.edu 2449376Sgblack@eecs.umich.edu InstCacheMap::iterator imIter = instCacheMap.find(m5Reg); 2459376Sgblack@eecs.umich.edu if (imIter != instCacheMap.end()) { 2469376Sgblack@eecs.umich.edu instMap = imIter->second; 2479376Sgblack@eecs.umich.edu } else { 2489376Sgblack@eecs.umich.edu instMap = new DecodeCache::InstMap; 2499376Sgblack@eecs.umich.edu instCacheMap[m5Reg] = instMap; 2509376Sgblack@eecs.umich.edu } 2519023Sgblack@eecs.umich.edu } 2529023Sgblack@eecs.umich.edu 2539478Snilay@cs.wisc.edu void takeOverFrom(Decoder *old) 2549478Snilay@cs.wisc.edu { 2559478Snilay@cs.wisc.edu mode = old->mode; 2569478Snilay@cs.wisc.edu submode = old->submode; 2579478Snilay@cs.wisc.edu emi.mode.mode = mode; 2589478Snilay@cs.wisc.edu emi.mode.submode = submode; 2599478Snilay@cs.wisc.edu altOp = old->altOp; 2609478Snilay@cs.wisc.edu defOp = old->defOp; 2619478Snilay@cs.wisc.edu altAddr = old->altAddr; 2629478Snilay@cs.wisc.edu defAddr = old->defAddr; 2639478Snilay@cs.wisc.edu stack = old->stack; 2649478Snilay@cs.wisc.edu } 2659478Snilay@cs.wisc.edu 2669023Sgblack@eecs.umich.edu void reset() 2679023Sgblack@eecs.umich.edu { 2689023Sgblack@eecs.umich.edu state = ResetState; 2699023Sgblack@eecs.umich.edu } 2709023Sgblack@eecs.umich.edu 2719023Sgblack@eecs.umich.edu void process(); 2729023Sgblack@eecs.umich.edu 2739023Sgblack@eecs.umich.edu //Use this to give data to the decoder. This should be used 2749023Sgblack@eecs.umich.edu //when there is control flow. 2759023Sgblack@eecs.umich.edu void moreBytes(const PCState &pc, Addr fetchPC, MachInst data) 2769023Sgblack@eecs.umich.edu { 2779023Sgblack@eecs.umich.edu DPRINTF(Decoder, "Getting more bytes.\n"); 2789023Sgblack@eecs.umich.edu basePC = fetchPC; 2799023Sgblack@eecs.umich.edu offset = (fetchPC >= pc.instAddr()) ? 0 : pc.instAddr() - fetchPC; 2809023Sgblack@eecs.umich.edu fetchChunk = data; 2819023Sgblack@eecs.umich.edu outOfBytes = false; 2829023Sgblack@eecs.umich.edu process(); 2839023Sgblack@eecs.umich.edu } 2849023Sgblack@eecs.umich.edu 2859023Sgblack@eecs.umich.edu bool needMoreBytes() 2869023Sgblack@eecs.umich.edu { 2879023Sgblack@eecs.umich.edu return outOfBytes; 2889023Sgblack@eecs.umich.edu } 2899023Sgblack@eecs.umich.edu 2909023Sgblack@eecs.umich.edu bool instReady() 2919023Sgblack@eecs.umich.edu { 2929023Sgblack@eecs.umich.edu return instDone; 2939023Sgblack@eecs.umich.edu } 2949023Sgblack@eecs.umich.edu 2959023Sgblack@eecs.umich.edu void 2969023Sgblack@eecs.umich.edu updateNPC(X86ISA::PCState &nextPC) 2979023Sgblack@eecs.umich.edu { 2989023Sgblack@eecs.umich.edu if (!nextPC.size()) { 2999023Sgblack@eecs.umich.edu int size = basePC + offset - origPC; 3009023Sgblack@eecs.umich.edu DPRINTF(Decoder, 3019023Sgblack@eecs.umich.edu "Calculating the instruction size: " 3029023Sgblack@eecs.umich.edu "basePC: %#x offset: %#x origPC: %#x size: %d\n", 3039023Sgblack@eecs.umich.edu basePC, offset, origPC, size); 3049023Sgblack@eecs.umich.edu nextPC.size(size); 3059023Sgblack@eecs.umich.edu nextPC.npc(nextPC.pc() + size); 3069023Sgblack@eecs.umich.edu } 3079023Sgblack@eecs.umich.edu } 3089023Sgblack@eecs.umich.edu 3099022Sgblack@eecs.umich.edu public: 3109022Sgblack@eecs.umich.edu StaticInstPtr decodeInst(ExtMachInst mach_inst); 3119022Sgblack@eecs.umich.edu 3129022Sgblack@eecs.umich.edu /// Decode a machine instruction. 3139022Sgblack@eecs.umich.edu /// @param mach_inst The binary instruction to decode. 3149022Sgblack@eecs.umich.edu /// @retval A pointer to the corresponding StaticInst object. 3159024Sgblack@eecs.umich.edu StaticInstPtr decode(ExtMachInst mach_inst, Addr addr); 3169376Sgblack@eecs.umich.edu StaticInstPtr decode(X86ISA::PCState &nextPC); 3179022Sgblack@eecs.umich.edu}; 3189020Sgblack@eecs.umich.edu 3199020Sgblack@eecs.umich.edu} // namespace X86ISA 3209020Sgblack@eecs.umich.edu 3219020Sgblack@eecs.umich.edu#endif // __ARCH_X86_DECODER_HH__ 322