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