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/*++
Copyright (c) 1994 Microsoft Corporation
Module Name:
logops.c
Abstract:
This module implements the code to emulate the and, or, test, xor,
and not opcodes.
Author:
David N. Cutler (davec) 12-Sep-1994
Environment:
Kernel mode only.
Revision History:
--*/
#include "nthal.h"
#include "emulate.h"
//
// Define forward referenced prototypes.
//
VOID
XmSetLogicalResult (
IN PRXM_CONTEXT P,
IN ULONG Result
);
VOID
XmAndOp (
IN PRXM_CONTEXT P
)
/*++
Routine Description:
This function emulates an and opcode.
Arguments:
P - Supplies a pointer to the emulation context structure.
Return Value:
None.
--*/
{
//
// And operands and store result.
//
XmSetLogicalResult(P, P->DstValue.Long & P->SrcValue.Long);
return;
}
VOID
XmOrOp (
IN PRXM_CONTEXT P
)
/*++
Routine Description:
This function emulates an or opcode.
Arguments:
P - Supplies a pointer to the emulation context structure.
Return Value:
None.
--*/
{
//
// Or operands and store result.
//
XmSetLogicalResult(P, P->DstValue.Long | P->SrcValue.Long);
return;
}
VOID
XmTestOp (
IN PRXM_CONTEXT P
)
/*++
Routine Description:
This function emulates a test opcode.
Arguments:
P - Supplies a pointer to the emulation context structure.
Return Value:
None.
--*/
{
//
// And operands but don't store result.
//
XmSetLogicalResult(P, P->DstValue.Long & P->SrcValue.Long);
return;
}
VOID
XmXorOp (
IN PRXM_CONTEXT P
)
/*++
Routine Description:
This function emulates a xor opcode.
Arguments:
P - Supplies a pointer to the emulation context structure.
Return Value:
None.
--*/
{
//
// Xor operands and store result.
//
XmSetLogicalResult(P, P->DstValue.Long ^ P->SrcValue.Long);
return;
}
VOID
XmNotOp (
IN PRXM_CONTEXT P
)
/*++
Routine Description:
This function emulates a not opcode.
Arguments:
P - Supplies a pointer to the emulation context structure.
Return Value:
None.
--*/
{
ULONG Mask;
ULONG Shift;
//
// Complement operand and store result.
//
Shift = Shift = ((P->DataType + 1) << 3) - 1;
Mask = ((1 << Shift) - 1) | (1 << Shift);
XmStoreResult(P, ~P->DstValue.Long & Mask);
return;
}
VOID
XmSetLogicalResult (
IN PRXM_CONTEXT P,
IN ULONG Result
)
/*++
Routine Description:
This function conditionally stores the result of a logical operation
and computes the resultant condtion codes.
Arguments:
P - Supplies a pointer to the emulation context structure.
Result - Supplies the result value (note that the result is always
zero extended to a long with no carry bits into the zero extended
part).
Return Value:
None.
--*/
{
ULONG Shift;
//
// Store the result and compute auxilary carry flag, parity flag, sign
// and zero flags.
//
if (P->FunctionIndex != X86_TEST_OP) {
XmStoreResult(P, Result);
}
Shift = Shift = ((P->DataType + 1) << 3) - 1;
P->Eflags.CF = 0;
P->Eflags.PF = XmComputeParity(Result);
P->Eflags.AF = 0;
P->Eflags.ZF = (Result == 0);
P->Eflags.SF = Result >> Shift;
P->Eflags.OF = 0;
return;
}
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