* Copyright (c) 2007 The Hewlett-Packard Development Company
* All rights reserved.
*
- * Redistribution and use of this software in source and binary forms,
- * with or without modification, are permitted provided that the
- * following conditions are met:
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder. You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
*
- * The software must be used only for Non-Commercial Use which means any
- * use which is NOT directed to receiving any direct monetary
- * compensation for, or commercial advantage from such use. Illustrative
- * examples of non-commercial use are academic research, personal study,
- * teaching, education and corporate research & development.
- * Illustrative examples of commercial use are distributing products for
- * commercial advantage and providing services using the software for
- * commercial advantage.
- *
- * If you wish to use this software or functionality therein that may be
- * covered by patents for commercial use, please contact:
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- * Office of Strategy and Technology
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- * the COPYRIGHT HOLDER(s), HEWLETT-PACKARD COMPANY, nor the names of its
+ * 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
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+ * 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
#ifndef __ARCH_X86_PREDECODER_HH__
#define __ARCH_X86_PREDECODER_HH__
+#include <cassert>
+
+#include "arch/x86/regs/misc.hh"
#include "arch/x86/types.hh"
#include "base/bitfield.hh"
#include "base/misc.hh"
-#include "sim/host.hh"
+#include "base/trace.hh"
+#include "base/types.hh"
+#include "debug/Predecoder.hh"
class ThreadContext;
class Predecoder
{
private:
+ //These are defined and documented in predecoder_tables.cc
static const uint8_t Prefixes[256];
static const uint8_t UsesModRM[2][256];
+ static const uint8_t ImmediateType[2][256];
+ static const uint8_t SizeTypeToSize[3][10];
protected:
ThreadContext * tc;
MachInst fetchChunk;
//The pc of the start of fetchChunk
Addr basePC;
+ //The pc the current instruction started at
+ Addr origPC;
//The offset into fetchChunk of current processing
int offset;
//The extended machine instruction being generated
ExtMachInst emi;
+ HandyM5Reg m5Reg;
+
+ inline uint8_t getNextByte()
+ {
+ return ((uint8_t *)&fetchChunk)[offset];
+ }
+
+ void getImmediate(int &collected, uint64_t ¤t, int size)
+ {
+ //Figure out how many bytes we still need to get for the
+ //immediate.
+ int toGet = size - collected;
+ //Figure out how many bytes are left in our "buffer"
+ int remaining = sizeof(MachInst) - offset;
+ //Get as much as we need, up to the amount available.
+ toGet = toGet > remaining ? remaining : toGet;
+
+ //Shift the bytes we want to be all the way to the right
+ uint64_t partialImm = fetchChunk >> (offset * 8);
+ //Mask off what we don't want
+ partialImm &= mask(toGet * 8);
+ //Shift it over to overlay with our displacement.
+ partialImm <<= (immediateCollected * 8);
+ //Put it into our displacement
+ current |= partialImm;
+ //Update how many bytes we've collected.
+ collected += toGet;
+ consumeBytes(toGet);
+ }
+
+ inline void consumeByte()
+ {
+ offset++;
+ assert(offset <= sizeof(MachInst));
+ if(offset == sizeof(MachInst))
+ outOfBytes = true;
+ }
+
+ inline void consumeBytes(int numBytes)
+ {
+ offset += numBytes;
+ assert(offset <= sizeof(MachInst));
+ if(offset == sizeof(MachInst))
+ outOfBytes = true;
+ }
+
+ void doReset();
//State machine state
protected:
bool emiIsReady;
//The size of the displacement value
int displacementSize;
- int displacementCollected;
//The size of the immediate value
int immediateSize;
+ //This is how much of any immediate value we've gotten. This is used
+ //for both the actual immediate and the displacement.
int immediateCollected;
- //These are local to some of the states. I need to turn the states
- //into inline functions to clean things up a bit.
- int toGet;
- int remaining;
- MachInst partialDisp;
-
enum State {
- Prefix,
- Opcode,
- ModRM,
- SIB,
- Displacement,
- Immediate
+ ResetState,
+ PrefixState,
+ OpcodeState,
+ ModRMState,
+ SIBState,
+ DisplacementState,
+ ImmediateState,
+ //We should never get to this state. Getting here is an error.
+ ErrorState
};
State state;
+ //Functions to handle each of the states
+ State doPrefixState(uint8_t);
+ State doOpcodeState(uint8_t);
+ State doModRMState(uint8_t);
+ State doSIBState(uint8_t);
+ State doDisplacementState();
+ State doImmediateState();
+
public:
Predecoder(ThreadContext * _tc) :
- tc(_tc), basePC(0), offset(0),
+ tc(_tc), basePC(0), origPC(0), offset(0),
outOfBytes(true), emiIsReady(false),
- state(Prefix)
- {}
+ state(ResetState)
+ {
+ emi.mode.mode = LongMode;
+ emi.mode.submode = SixtyFourBitMode;
+ m5Reg = 0;
+ }
+
+ void reset()
+ {
+ state = ResetState;
+ }
ThreadContext * getTC()
{
tc = _tc;
}
- void process()
- {
- warn("About to process some bytes\n");
- assert(!outOfBytes);
- assert(!emiIsReady);
- while(!emiIsReady && !outOfBytes)
- {
- uint8_t nextByte = (fetchChunk >> (offset * 8)) & 0xff;
- switch(state)
- {
- case Prefix:
- uint8_t prefix = Prefixes[nextByte];
- switch(prefix)
- {
- //Operand size override prefixes
- case OperandSizeOverride:
- warn("Found operand size override prefix!\n");
- offset++;
- break;
- case AddressSizeOverride:
- warn("Found address size override prefix!\n");
- offset++;
- break;
- //Segment override prefixes
- case CSOverride:
- warn("Found cs segment override!\n");
- offset++;
- break;
- case DSOverride:
- warn("Found ds segment override!\n");
- offset++;
- break;
- case ESOverride:
- warn("Found es segment override!\n");
- offset++;
- break;
- case FSOverride:
- warn("Found fs segment override!\n");
- offset++;
- break;
- case GSOverride:
- warn("Found gs segment override!\n");
- offset++;
- break;
- case SSOverride:
- warn("Found ss segment override!\n");
- offset++;
- break;
- case Lock:
- warn("Found lock prefix!\n");
- offset++;
- break;
- case Rep:
- warn("Found rep prefix!\n");
- offset++;
- break;
- case Repne:
- warn("Found repne prefix!\n");
- offset++;
- break;
- case Rex:
- warn("Found Rex prefix %#x!\n", nextByte);
- offset++;
- break;
- case 0:
- emi.twoByteOpcode = false;
- state = Opcode;
- break;
- default:
- panic("Unrecognized prefix %#x\n", nextByte);
- }
- break;
- case Opcode:
- if(nextByte == 0xf0)
- {
- warn("Found two byte opcode!\n");
- emi.twoByteOpcode = true;
- }
- else
- {
- warn("Found opcode %#x!\n", nextByte);
- if (UsesModRM[emi.twoByteOpcode ? 1 : 0][nextByte]) {
- state = ModRM;
- } else if(0 /* uses immediate */) {
- //Figure out how big the immediate should be
- immediateCollected = 0;
- emi.immediate = 0;
- state = Immediate;
- } else {
- emiIsReady = true;
- state = Prefix;
- }
- }
- offset++;
- break;
- case ModRM:
- warn("Found modrm byte %#x!\n", nextByte);
- if (0) {//in 16 bit mode
- //figure out 16 bit displacement size
- if(nextByte & 0xC7 == 0x06 ||
- nextByte & 0xC0 == 0x40)
- displacementSize = 1;
- else if(nextByte & 0xC7 == 0x80)
- displacementSize = 2;
- else
- displacementSize = 0;
- } else {
- //figure out 32/64 bit displacement size
- if(nextByte & 0xC7 == 0x06 ||
- nextByte & 0xC0 == 0x40)
- displacementSize = 4;
- else if(nextByte & 0xC7 == 0x80)
- displacementSize = 2;
- else
- displacementSize = 4;
- }
- //If there's an SIB, get that next.
- //There is no SIB in 16 bit mode.
- if(nextByte & 0x7 == 4 &&
- nextByte & 0xC0 != 0xC0) {
- // && in 32/64 bit mode)
- state = SIB;
- } else if(displacementSize) {
- displacementCollected = 0;
- emi.displacement = 0;
- state = Displacement;
- } else if(immediateSize) {
- immediateCollected = 0;
- emi.immediate = 0;
- state = Immediate;
- } else {
- emiIsReady = true;
- state = Prefix;
- }
- //The ModRM byte is consumed no matter what
- offset++;
- break;
- case SIB:
- warn("Found SIB byte %#x!\n", nextByte);
- offset++;
- if(displacementSize) {
- displacementCollected = 0;
- emi.displacement = 0;
- state = Displacement;
- } else if(immediateSize) {
- immediateCollected = 0;
- emi.immediate = 0;
- state = Immediate;
- } else {
- emiIsReady = true;
- state = Prefix;
- }
- break;
- case Displacement:
- //Gather up the displacement, or at least as much of it
- //as we can get.
-
- //Figure out how many bytes we still need to get for the
- //displacement.
- toGet = displacementSize - displacementCollected;
- //Figure out how many bytes are left in our "buffer"
- remaining = sizeof(MachInst) - offset;
- //Get as much as we need, up to the amount available.
- toGet = toGet > remaining ? remaining : toGet;
-
- //Shift the bytes we want to be all the way to the right
- partialDisp = fetchChunk >> offset;
- //Mask off what we don't want
- partialDisp &= mask(toGet * 8);
- //Shift it over to overlay with our displacement.
- partialDisp <<= displacementCollected;
- //Put it into our displacement
- emi.displacement |= partialDisp;
- //Update how many bytes we've collected.
- displacementCollected += toGet;
-
- if(displacementSize == displacementCollected) {
- //Sign extend the displacement
- switch(displacementSize)
- {
- case 1:
- emi.displacement = sext<8>(emi.displacement);
- break;
- case 2:
- emi.displacement = sext<16>(emi.displacement);
- break;
- case 4:
- emi.displacement = sext<32>(emi.displacement);
- break;
- default:
- panic("Undefined displacement size!\n");
- }
- if(immediateSize) {
- immediateCollected = 0;
- emi.immediate = 0;
- state = Immediate;
- } else {
- emiIsReady = true;
- state = Prefix;
- }
- }
- break;
- case Immediate:
- //Gather up the displacement, or at least as much of it
- //as we can get
-
- //Figure out how many bytes we still need to get for the
- //immediate.
- toGet = immediateSize - immediateCollected;
- //Figure out how many bytes are left in our "buffer"
- remaining = sizeof(MachInst) - offset;
- //Get as much as we need, up to the amount available.
- toGet = toGet > remaining ? remaining : toGet;
-
- //Shift the bytes we want to be all the way to the right
- partialDisp = fetchChunk >> offset;
- //Mask off what we don't want
- partialDisp &= mask(toGet * 8);
- //Shift it over to overlay with our immediate.
- partialDisp <<= displacementCollected;
- //Put it into our immediate
- emi.displacement |= partialDisp;
- //Update how many bytes we've collected.
- displacementCollected += toGet;
- if(immediateSize == immediateCollected)
- {
- emiIsReady = true;
- state = Prefix;
- }
- break;
- default:
- panic("Unrecognized state! %d\n", state);
- }
- if(offset == sizeof(MachInst))
- outOfBytes = true;
- }
- }
+ void process();
//Use this to give data to the predecoder. This should be used
//when there is control flow.
- void moreBytes(Addr currPC, Addr off, MachInst data)
+ void moreBytes(const PCState &pc, Addr fetchPC, MachInst data)
{
- basePC = currPC;
- offset = off;
+ DPRINTF(Predecoder, "Getting more bytes.\n");
+ basePC = fetchPC;
+ offset = (fetchPC >= pc.instAddr()) ? 0 : pc.instAddr() - fetchPC;
fetchChunk = data;
- assert(off < sizeof(MachInst));
outOfBytes = false;
- warn("About to call process.\n");
process();
}
- //Use this to give data to the predecoder. This should be used
- //when instructions are executed in order.
- void moreBytes(MachInst machInst)
- {
- moreBytes(basePC + sizeof(machInst), 0, machInst);
- }
-
bool needMoreBytes()
{
return outOfBytes;
return emiIsReady;
}
+ int
+ getInstSize()
+ {
+ int size = basePC + offset - origPC;
+ DPRINTF(Predecoder,
+ "Calculating the instruction size: "
+ "basePC: %#x offset: %#x origPC: %#x size: %d\n",
+ basePC, offset, origPC, size);
+ return size;
+ }
+
//This returns a constant reference to the ExtMachInst to avoid a copy
- const ExtMachInst & getExtMachInst()
+ const ExtMachInst &
+ getExtMachInst(X86ISA::PCState &nextPC)
{
assert(emiIsReady);
emiIsReady = false;
+ if (!nextPC.size()) {
+ Addr size = getInstSize();
+ nextPC.size(size);
+ nextPC.npc(nextPC.pc() + size);
+ }
return emi;
}
};
projects / gem5.git / blobdiff