reactos/lib/soft386/opgroups.c
Aleksandar Andrejevic 17a32f3b2a [SOFT386]
Change the license of Soft386 to GPLv2. The previous license was also
GPLv2, but it had a runtime linking exception. The new license is the
original GPLv2 with no exceptions.


svn path=/branches/ntvdm/; revision=60485
2013-09-30 22:01:38 +00:00

1067 lines
28 KiB
C

/*
* Soft386 386/486 CPU Emulation Library
* opgroups.c
*
* Copyright (C) 2013 Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/* INCLUDES *******************************************************************/
// #define WIN32_NO_STATUS
// #define _INC_WINDOWS
#include <windef.h>
// #define NDEBUG
#include <debug.h>
#include <soft386.h>
#include "opcodes.h"
#include "common.h"
/* PRIVATE FUNCTIONS **********************************************************/
inline
static
ULONG
Soft386ArithmeticOperation(PSOFT386_STATE State,
INT Operation,
ULONG FirstValue,
ULONG SecondValue,
UCHAR Bits)
{
ULONG Result;
ULONG SignFlag = 1 << (Bits - 1);
ULONG MaxValue = (1 << Bits) - 1;
/* Make sure the values don't exceed the maximum for their size */
FirstValue &= MaxValue;
SecondValue &= MaxValue;
/* Check which operation is this */
switch (Operation)
{
/* ADD */
case 0:
{
Result = (FirstValue + SecondValue) & MaxValue;
/* Update CF, OF and AF */
State->Flags.Cf = (Result < FirstValue) && (Result < SecondValue);
State->Flags.Of = ((FirstValue & SignFlag) == (SecondValue & SignFlag))
&& ((FirstValue & SignFlag) != (Result & SignFlag));
State->Flags.Af = (((FirstValue & 0x0F) + (SecondValue & 0x0F)) & 0x10) ? TRUE : FALSE;
break;
}
/* OR */
case 1:
{
Result = FirstValue | SecondValue;
break;
}
/* ADC */
case 2:
{
INT Carry = State->Flags.Cf ? 1 : 0;
Result = (FirstValue + SecondValue + Carry) & MaxValue;
/* Update CF, OF and AF */
State->Flags.Cf = ((SecondValue == MaxValue) && (Carry == 1))
|| ((Result < FirstValue) && (Result < (SecondValue + Carry)));
State->Flags.Of = ((FirstValue & SignFlag) == (SecondValue & SignFlag))
&& ((FirstValue & SignFlag) != (Result & SignFlag));
State->Flags.Af = (((FirstValue & 0x0F) + ((SecondValue + Carry) & 0x0F)) & 0x10)
? TRUE : FALSE;
break;
}
/* SBB */
case 3:
{
INT Carry = State->Flags.Cf ? 1 : 0;
Result = (FirstValue - SecondValue - Carry) & MaxValue;
/* Update CF, OF and AF */
State->Flags.Cf = FirstValue < (SecondValue + Carry);
State->Flags.Of = ((FirstValue & SignFlag) != (SecondValue & SignFlag))
&& ((FirstValue & SignFlag) != (Result & SignFlag));
State->Flags.Af = (FirstValue & 0x0F) < ((SecondValue + Carry) & 0x0F);
break;
}
/* AND */
case 4:
{
Result = FirstValue & SecondValue;
break;
}
/* SUB or CMP */
case 5:
case 7:
{
Result = (FirstValue - SecondValue) & MaxValue;
/* Update CF, OF and AF */
State->Flags.Cf = FirstValue < SecondValue;
State->Flags.Of = ((FirstValue & SignFlag) != (SecondValue & SignFlag))
&& ((FirstValue & SignFlag) != (Result & SignFlag));
State->Flags.Af = (FirstValue & 0x0F) < (SecondValue & 0x0F);
break;
}
/* XOR */
case 6:
{
Result = FirstValue ^ SecondValue;
break;
}
default:
{
/* Shouldn't happen */
ASSERT(FALSE);
}
}
/* Update ZF, SF and PF */
State->Flags.Zf = (Result == 0) ? TRUE : FALSE;
State->Flags.Sf = (Result & SignFlag) ? TRUE : FALSE;
State->Flags.Pf = Soft386CalculateParity(LOBYTE(Result));
/* Return the result */
return Result;
}
static
inline
ULONG
Soft386RotateOperation(PSOFT386_STATE State,
INT Operation,
ULONG Value,
UCHAR Bits,
UCHAR Count)
{
ULONG HighestBit = 1 << (Bits - 1);
ULONG Result;
if ((Operation != 2) && (Operation != 3))
{
/* Mask the count */
Count &= Bits - 1;
}
else
{
/* For RCL and RCR, the CF is included in the value */
Count %= Bits + 1;
}
/* Check which operation is this */
switch (Operation)
{
/* ROL */
case 0:
{
Result = (Value << Count) | (Value >> (Bits - Count));
/* Update CF and OF */
State->Flags.Cf = Result & 1;
if (Count == 1) State->Flags.Of = ((Result & HighestBit) ? TRUE : FALSE)
^ State->Flags.Cf;
break;
}
/* ROR */
case 1:
{
Result = (Value >> Count) | (Value << (Bits - Count));
/* Update CF and OF */
State->Flags.Cf = (Result & HighestBit) ? TRUE : FALSE;
if (Count == 1) State->Flags.Of = State->Flags.Cf
^ ((Result & (HighestBit >> 1))
? TRUE : FALSE);
break;
}
/* RCL */
case 2:
{
Result = (Value << Count)
| (State->Flags.Cf << (Count - 1))
| (Value >> (Bits - Count + 1));
/* Update CF and OF */
State->Flags.Cf = (Value & (1 << (Bits - Count))) ? TRUE : FALSE;
if (Count == 1) State->Flags.Of = ((Result & HighestBit) ? TRUE : FALSE)
^ State->Flags.Cf;
break;
}
/* RCR */
case 3:
{
Result = (Value >> Count)
| (State->Flags.Cf << (Bits - Count))
| (Value << (Bits - Count + 1));
/* Update CF and OF */
State->Flags.Cf = (Value & (1 << (Bits - Count))) ? TRUE : FALSE;
if (Count == 1) State->Flags.Of = State->Flags.Cf
^ ((Result & (HighestBit >> 1))
? TRUE : FALSE);
break;
}
/* SHL/SAL */
case 4:
case 6:
{
Result = Value << Count;
/* Update CF and OF */
State->Flags.Cf = (Value & (1 << (Bits - Count))) ? TRUE : FALSE;
if (Count == 1) State->Flags.Of = ((Result & HighestBit) ? TRUE : FALSE)
^ (State->Flags.Cf ? TRUE : FALSE);
break;
}
/* SHR */
case 5:
{
Result = Value >> Count;
/* Update CF and OF */
State->Flags.Cf = (Value & (1 << (Count - 1))) ? TRUE : FALSE;
if (Count == 1) State->Flags.Of = (Value & HighestBit) ? TRUE : FALSE;
break;
}
/* SAR */
case 7:
{
Result = Value >> Count;
/* Fill the top Count bits with the sign bit */
if (Value & HighestBit) Result |= ((1 << Count) - 1) << (Bits - Count);
/* Update CF and OF */
State->Flags.Cf = Value & 1;
if (Count == 1) State->Flags.Of = FALSE;
break;
}
}
/* Update ZF, SF and PF */
State->Flags.Zf = (Result == 0) ? TRUE : FALSE;
State->Flags.Sf = (Result & HighestBit) ? TRUE : FALSE;
State->Flags.Pf = Soft386CalculateParity(Result);
/* Return the result */
return Result;
}
/* PUBLIC FUNCTIONS ***********************************************************/
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroup8082)
{
UCHAR Immediate, Dummy, Value;
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
/* Fetch the immediate operand */
if (!Soft386FetchByte(State, &Immediate))
{
/* Exception occurred */
return FALSE;
}
/* Read the operands */
if (!Soft386ReadModrmByteOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = Soft386ArithmeticOperation(State, ModRegRm.Register, Value, Immediate, 8);
/* Unless this is CMP, write back the result */
if (ModRegRm.Register != 7)
{
return Soft386WriteModrmByteOperands(State, &ModRegRm, FALSE, Value);
}
return TRUE;
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroup81)
{
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN OperandSize, AddressSize;
OperandSize = AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_OPSIZE)
{
/* The OPSIZE prefix toggles the size */
OperandSize = !OperandSize;
}
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
if (OperandSize)
{
ULONG Immediate, Value, Dummy;
/* Fetch the immediate operand */
if (!Soft386FetchDword(State, &Immediate))
{
/* Exception occurred */
return FALSE;
}
/* Read the operands */
if (!Soft386ReadModrmDwordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = Soft386ArithmeticOperation(State, ModRegRm.Register, Value, Immediate, 32);
/* Unless this is CMP, write back the result */
if (ModRegRm.Register != 7)
{
return Soft386WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value);
}
}
else
{
USHORT Immediate, Value, Dummy;
/* Fetch the immediate operand */
if (!Soft386FetchWord(State, &Immediate))
{
/* Exception occurred */
return FALSE;
}
/* Read the operands */
if (!Soft386ReadModrmWordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = Soft386ArithmeticOperation(State, ModRegRm.Register, Value, Immediate, 16);
/* Unless this is CMP, write back the result */
if (ModRegRm.Register != 7)
{
return Soft386WriteModrmWordOperands(State, &ModRegRm, FALSE, Value);
}
}
return TRUE;
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroup83)
{
CHAR ImmByte;
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN OperandSize, AddressSize;
OperandSize = AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_OPSIZE)
{
/* The OPSIZE prefix toggles the size */
OperandSize = !OperandSize;
}
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
/* Fetch the immediate operand */
if (!Soft386FetchByte(State, (PUCHAR)&ImmByte))
{
/* Exception occurred */
return FALSE;
}
if (OperandSize)
{
ULONG Immediate = (ULONG)((LONG)ImmByte); // Sign extend
ULONG Value, Dummy;
/* Read the operands */
if (!Soft386ReadModrmDwordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = Soft386ArithmeticOperation(State, ModRegRm.Register, Value, Immediate, 32);
/* Unless this is CMP, write back the result */
if (ModRegRm.Register != 7)
{
return Soft386WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value);
}
}
else
{
USHORT Immediate = (USHORT)((SHORT)ImmByte); // Sign extend
USHORT Value, Dummy;
/* Read the operands */
if (!Soft386ReadModrmWordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = Soft386ArithmeticOperation(State, ModRegRm.Register, Value, Immediate, 16);
/* Unless this is CMP, write back the result */
if (ModRegRm.Register != 7)
{
return Soft386WriteModrmWordOperands(State, &ModRegRm, FALSE, Value);
}
}
return TRUE;
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroup8F)
{
ULONG Value;
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN OperandSize, AddressSize;
OperandSize = AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_OPSIZE)
{
/* The OPSIZE prefix toggles the size */
OperandSize = !OperandSize;
}
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
if (ModRegRm.Register != 0)
{
/* Invalid */
Soft386Exception(State, SOFT386_EXCEPTION_UD);
return FALSE;
}
/* Pop a value from the stack */
if (!Soft386StackPop(State, &Value))
{
/* Exception occurred */
return FALSE;
}
if (OperandSize)
{
return Soft386WriteModrmDwordOperands(State,
&ModRegRm,
FALSE,
Value);
}
else
{
return Soft386WriteModrmWordOperands(State,
&ModRegRm,
FALSE,
LOWORD(Value));
}
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupC0)
{
UCHAR Dummy, Value, Count;
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
/* Fetch the count */
if (!Soft386FetchByte(State, &Count))
{
/* Exception occurred */
return FALSE;
}
/* Read the operands */
if (!Soft386ReadModrmByteOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = LOBYTE(Soft386RotateOperation(State,
ModRegRm.Register,
Value,
8,
Count));
/* Write back the result */
return Soft386WriteModrmByteOperands(State,
&ModRegRm,
FALSE,
Value);
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupC1)
{
UCHAR Count;
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN OperandSize, AddressSize;
OperandSize = AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_OPSIZE)
{
/* The OPSIZE prefix toggles the size */
OperandSize = !OperandSize;
}
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
/* Fetch the count */
if (!Soft386FetchByte(State, &Count))
{
/* Exception occurred */
return FALSE;
}
if (OperandSize)
{
ULONG Dummy, Value;
/* Read the operands */
if (!Soft386ReadModrmDwordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = Soft386RotateOperation(State,
ModRegRm.Register,
Value,
32,
Count);
/* Write back the result */
return Soft386WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value);
}
else
{
USHORT Dummy, Value;
/* Read the operands */
if (!Soft386ReadModrmWordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = LOWORD(Soft386RotateOperation(State,
ModRegRm.Register,
Value,
16,
Count));
/* Write back the result */
return Soft386WriteModrmWordOperands(State, &ModRegRm, FALSE, Value);
}
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupC6)
{
UCHAR Immediate;
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
if (ModRegRm.Register != 0)
{
/* Invalid */
Soft386Exception(State, SOFT386_EXCEPTION_UD);
return FALSE;
}
/* Get the immediate operand */
if (!Soft386FetchByte(State, &Immediate))
{
/* Exception occurred */
return FALSE;
}
return Soft386WriteModrmByteOperands(State,
&ModRegRm,
FALSE,
Immediate);
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupC7)
{
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN OperandSize, AddressSize;
OperandSize = AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_OPSIZE)
{
/* The OPSIZE prefix toggles the size */
OperandSize = !OperandSize;
}
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
if (ModRegRm.Register != 0)
{
/* Invalid */
Soft386Exception(State, SOFT386_EXCEPTION_UD);
return FALSE;
}
if (OperandSize)
{
ULONG Immediate;
/* Get the immediate operand */
if (!Soft386FetchDword(State, &Immediate))
{
/* Exception occurred */
return FALSE;
}
return Soft386WriteModrmDwordOperands(State,
&ModRegRm,
FALSE,
Immediate);
}
else
{
USHORT Immediate;
/* Get the immediate operand */
if (!Soft386FetchWord(State, &Immediate))
{
/* Exception occurred */
return FALSE;
}
return Soft386WriteModrmWordOperands(State,
&ModRegRm,
FALSE,
Immediate);
}
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupD0)
{
UCHAR Dummy, Value;
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
/* Read the operands */
if (!Soft386ReadModrmByteOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = LOBYTE(Soft386RotateOperation(State, ModRegRm.Register, Value, 8, 1));
/* Write back the result */
return Soft386WriteModrmByteOperands(State,
&ModRegRm,
FALSE,
Value);
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupD1)
{
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN OperandSize, AddressSize;
OperandSize = AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_OPSIZE)
{
/* The OPSIZE prefix toggles the size */
OperandSize = !OperandSize;
}
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
if (OperandSize)
{
ULONG Dummy, Value;
/* Read the operands */
if (!Soft386ReadModrmDwordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = Soft386RotateOperation(State, ModRegRm.Register, Value, 32, 1);
/* Write back the result */
return Soft386WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value);
}
else
{
USHORT Dummy, Value;
/* Read the operands */
if (!Soft386ReadModrmWordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = LOWORD(Soft386RotateOperation(State, ModRegRm.Register, Value, 16, 1));
/* Write back the result */
return Soft386WriteModrmWordOperands(State, &ModRegRm, FALSE, Value);
}
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupD2)
{
UCHAR Dummy, Value;
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
/* Read the operands */
if (!Soft386ReadModrmByteOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = LOBYTE(Soft386RotateOperation(State,
ModRegRm.Register,
Value,
8,
State->GeneralRegs[SOFT386_REG_ECX].LowByte));
/* Write back the result */
return Soft386WriteModrmByteOperands(State,
&ModRegRm,
FALSE,
Value);
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupD3)
{
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN OperandSize, AddressSize;
OperandSize = AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_OPSIZE)
{
/* The OPSIZE prefix toggles the size */
OperandSize = !OperandSize;
}
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
if (OperandSize)
{
ULONG Dummy, Value;
/* Read the operands */
if (!Soft386ReadModrmDwordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = Soft386RotateOperation(State,
ModRegRm.Register,
Value,
32,
State->GeneralRegs[SOFT386_REG_ECX].LowByte);
/* Write back the result */
return Soft386WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value);
}
else
{
USHORT Dummy, Value;
/* Read the operands */
if (!Soft386ReadModrmWordOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
/* Calculate the result */
Value = LOWORD(Soft386RotateOperation(State,
ModRegRm.Register,
Value,
16,
State->GeneralRegs[SOFT386_REG_ECX].LowByte));
/* Write back the result */
return Soft386WriteModrmWordOperands(State, &ModRegRm, FALSE, Value);
}
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupF6)
{
UNIMPLEMENTED;
return FALSE; // TODO: NOT IMPLEMENTED
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupF7)
{
UNIMPLEMENTED;
return FALSE; // TODO: NOT IMPLEMENTED
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupFE)
{
UCHAR Dummy, Value;
SOFT386_MOD_REG_RM ModRegRm;
BOOLEAN AddressSize = State->SegmentRegs[SOFT386_REG_CS].Size;
if (State->PrefixFlags & SOFT386_PREFIX_ADSIZE)
{
/* The ADSIZE prefix toggles the size */
AddressSize = !AddressSize;
}
if (!Soft386ParseModRegRm(State, AddressSize, &ModRegRm))
{
/* Exception occurred */
return FALSE;
}
if (ModRegRm.Register > 1)
{
/* Invalid */
Soft386Exception(State, SOFT386_EXCEPTION_UD);
return FALSE;
}
/* Read the operands */
if (!Soft386ReadModrmByteOperands(State, &ModRegRm, &Dummy, &Value))
{
/* Exception occurred */
return FALSE;
}
if (ModRegRm.Register == 0)
{
/* Increment and update OF */
Value++;
State->Flags.Of = (Value == SIGN_FLAG_BYTE) ? TRUE : FALSE;
}
else
{
/* Decrement and update OF */
State->Flags.Of = (Value == SIGN_FLAG_BYTE) ? TRUE : FALSE;
Value--;
}
/* Update flags */
State->Flags.Sf = (Value & SIGN_FLAG_BYTE) ? TRUE : FALSE;
State->Flags.Zf = (Value == 0) ? TRUE : FALSE;
State->Flags.Af = ((Value & 0x0F) == 0) ? TRUE : FALSE;
State->Flags.Pf = Soft386CalculateParity(Value);
/* Write back the result */
return Soft386WriteModrmByteOperands(State,
&ModRegRm,
FALSE,
Value);
}
SOFT386_OPCODE_HANDLER(Soft386OpcodeGroupFF)
{
UNIMPLEMENTED;
return FALSE; // TODO: NOT IMPLEMENTED
}
/* EOF */