581 lines
10 KiB
C
581 lines
10 KiB
C
/*++
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Copyright (c) 1994 Microsoft Corporation
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Module Name:
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mulops.c
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Abstract:
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This module implements the code to emulate the shift opcodes.
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Author:
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David N. Cutler (davec) 21-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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VOID
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XmRolOp (
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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 rol 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 Carry;
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ULONG Count;
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ULONG Mask;
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ULONG Shift;
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ULONG Value;
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//
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// Rotate destination left and store result.
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//
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Shift = ((P->DataType + 1) << 3) - 1;
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Mask = ((1 << Shift) - 1) | (1 << Shift);
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Value = P->DstValue.Long;
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Count = P->SrcValue.Long & Shift;
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if (Count != 0) {
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if (Count == 1) {
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P->Eflags.EFLAG_OF = (Value >> Shift) ^ (Value >> (Shift - 1));
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}
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do {
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Carry = Value >> Shift;
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Value = Carry | ((Value << 1) & Mask);
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Count -= 1;
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} while (Count != 0);
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P->Eflags.EFLAG_CF = Carry;
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}
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XmStoreResult(P, Value);
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return;
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}
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VOID
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XmRorOp (
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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 ror 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 Carry;
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ULONG Count;
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ULONG Shift;
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ULONG Value;
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//
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// Rotate destination right and store result.
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//
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Shift = ((P->DataType + 1) << 3) - 1;
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Value = P->DstValue.Long;
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Count = P->SrcValue.Long & Shift;
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if (Count != 0) {
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if (Count == 1) {
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P->Eflags.EFLAG_OF = (Value >> Shift) ^ (Value & 0x1);
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}
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do {
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Carry = Value & 1;
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Value = (Carry << Shift) | (Value >> 1);
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Count -= 1;
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} while (Count != 0 );
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P->Eflags.EFLAG_CF = Carry;
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}
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XmStoreResult(P, Value);
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return;
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}
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VOID
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XmRclOp (
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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 rcl 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 Carry;
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ULONG Count;
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ULONG Mask;
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ULONG Shift;
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ULONG Temp;
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ULONG Value;
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//
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// Rotate destination left through carry and store result.
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//
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Shift = ((P->DataType + 1) << 3) - 1;
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Mask = ((1 << Shift) - 1) | (1 << Shift);
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Value = P->DstValue.Long;
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Count = P->SrcValue.Long & Shift;
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Carry = P->Eflags.EFLAG_CF;
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if (Count != 0) {
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if (Count == 1) {
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P->Eflags.EFLAG_OF = (Value >> Shift) ^ (Value >> (Shift - 1));
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}
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do {
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Temp = Value >> Shift;
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Value = ((Value << 1) & Mask) | Carry;
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Carry = Temp;
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Count -= 1;
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} while (Count != 0);
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}
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XmStoreResult(P, Value);
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P->Eflags.EFLAG_CF = Carry;
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return;
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}
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VOID
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XmRcrOp (
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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 rcr 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 Carry;
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ULONG Count;
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ULONG Shift;
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ULONG Temp;
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ULONG Value;
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//
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// Rotate destination right through carry and store result.
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//
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Shift = ((P->DataType + 1) << 3) - 1;
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Value = P->DstValue.Long;
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Count = P->SrcValue.Long & Shift;
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Carry = P->Eflags.EFLAG_CF;
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if (Count != 0) {
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if (Count == 1) {
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P->Eflags.EFLAG_OF = (Value >> Shift) ^ Carry;
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}
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do {
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Temp = Value & 1;
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Value = (Carry << Shift) | (Value >> 1);
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Carry = Temp;
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Count -= 1;
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} while (Count != 0);
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}
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XmStoreResult(P, Value);
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P->Eflags.EFLAG_CF = Carry;
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return;
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}
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VOID
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XmShlOp (
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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 shl 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 Carry;
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ULONG Count;
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ULONG Overflow;
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ULONG Shift;
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ULONG Value;
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//
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// Shift destination left logical and store result.
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//
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Shift = ((P->DataType + 1) << 3) - 1;
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Value = P->DstValue.Long;
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Count = P->SrcValue.Long;
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if (Count != 0) {
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if (P->DataType == LONG_DATA) {
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Overflow = (Value ^ (Value << 1)) >> 31;
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Carry = Value >> (32 - Count);
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Value <<= Count;
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} else if (P->DataType == WORD_DATA) {
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Overflow = (Value ^ (Value << 1)) >> 15;
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Carry = Value >> (16 - Count);
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Value = (Value << Count) & 0xffff;
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} else {
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Overflow = (Value ^ (Value << 1)) >> 7;
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Carry = Value >> (8 - Count);
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Value = (Value << Count) & 0xff;
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}
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P->Eflags.EFLAG_CF = Carry;
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P->Eflags.EFLAG_OF = Overflow;
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P->Eflags.EFLAG_PF = XmComputeParity(Value);
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P->Eflags.EFLAG_ZF = (Value == 0);
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P->Eflags.EFLAG_SF = Value >> Shift;
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}
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XmStoreResult(P, Value);
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return;
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}
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VOID
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XmShrOp (
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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 shr 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 Carry;
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ULONG Count;
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ULONG Overflow;
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ULONG Shift;
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ULONG Value;
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//
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// Shift destination right logical and store result.
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//
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Shift = ((P->DataType + 1) << 3) - 1;
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Value = P->DstValue.Long;
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Count = P->SrcValue.Long;
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if (Count != 0) {
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if (P->DataType == LONG_DATA) {
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Overflow = Value >> 31;
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Carry = Value >> (Count - 1);
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Value >>= Count;
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} else if (P->DataType == WORD_DATA) {
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Overflow = Value >> 15;
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Carry = Value >> (Count - 1);
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Value >>= Count;
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} else {
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Overflow = Value >> 7;
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Carry = Value >> (Count - 1);
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Value >>= Count;
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}
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P->Eflags.EFLAG_CF = Carry;
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P->Eflags.EFLAG_OF = Overflow;
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P->Eflags.EFLAG_PF = XmComputeParity(Value);
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P->Eflags.EFLAG_ZF = (Value == 0);
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P->Eflags.EFLAG_SF = Value >> Shift;
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}
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XmStoreResult(P, Value);
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return;
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}
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VOID
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XmSarOp (
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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 sar 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 Carry;
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ULONG Count;
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ULONG Shift;
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LONG Value;
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//
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// Shift destination right arithmetic and store result.
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//
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Shift = ((P->DataType + 1) << 3) - 1;
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Value = (LONG)P->DstValue.Long;
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Count = P->SrcValue.Long;
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if (Count != 0) {
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if (P->DataType == LONG_DATA) {
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Carry = Value >> (Count - 1);
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Value >>= Count;
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} else if (P->DataType == WORD_DATA) {
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Carry = Value >> (Count - 1);
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Value = ((Value << 16) >> (Count + 16)) & 0xffff;
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} else {
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Carry = Value >> (Count - 1);
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Value = ((Value << 24) >> (Count + 24)) & 0xff;
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}
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P->Eflags.EFLAG_CF = Carry;
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P->Eflags.EFLAG_OF = 0;
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P->Eflags.EFLAG_PF = XmComputeParity(Value);
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P->Eflags.EFLAG_ZF = (Value == 0);
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P->Eflags.EFLAG_SF = Value >> Shift;
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}
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XmStoreResult(P, (ULONG)Value);
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return;
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}
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VOID
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XmShldOp (
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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 shld 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 Carry;
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ULONG Count;
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ULONG High;
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ULONG Low;
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ULONG Sign;
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//
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// Double shift left logical and store result.
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//
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// The low 32-bits of the shift are the source.
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// The high 32-bits of the shift are the destination.
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// The shift count has been masked modulo the datatype.
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//
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// This shift is equivalent to extracting the high 32-bits of the left
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// shifted result.
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//
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Low = P->SrcValue.Long;
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High = P->DstValue.Long;
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Count = P->Shift;
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if (Count != 0) {
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if (P->DataType == LONG_DATA) {
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if (Count == 1) {
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P->Eflags.EFLAG_OF = (High ^ (High << 1)) >> 31;
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}
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Carry = High >> (32 - Count);
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High = (High << Count) | (Low >> (32 - Count));
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Sign = High >> 31;
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} else {
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if (Count == 1) {
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P->Eflags.EFLAG_OF = (High ^ (High << 1)) >> 15;
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}
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Carry = High >> (16 - Count);
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High = ((High << Count) | (Low >> (16 - Count))) & 0xffff;
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Sign = High >> 15;
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}
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P->Eflags.EFLAG_CF = Carry;
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P->Eflags.EFLAG_PF = XmComputeParity(High);
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P->Eflags.EFLAG_ZF = (High == 0);
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P->Eflags.EFLAG_SF = Sign;
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}
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XmStoreResult(P, High);
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return;
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}
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VOID
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XmShrdOp (
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IN PRXM_CONTEXT P
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)
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||
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/*++
|
||
|
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Routine Description:
|
||
|
||
This function emulates a shrd opcode.
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Arguments:
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|
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P - Supplies a pointer to the emulation context structure.
|
||
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Return Value:
|
||
|
||
None.
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||
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--*/
|
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|
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{
|
||
|
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ULONG Carry;
|
||
ULONG Count;
|
||
ULONG High;
|
||
ULONG Low;
|
||
ULONG Sign;
|
||
|
||
//
|
||
// Double shift right logical and store result.
|
||
//
|
||
// The high 32-bits of the shift are the source.
|
||
// The low 32-bits of the shift are the destination.
|
||
// The shift count has been masked modulo the datatype.
|
||
//
|
||
// This shift is equivalent to extracting the low 32-bits of the right
|
||
// shifted result.
|
||
//
|
||
|
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High = P->SrcValue.Long;
|
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Low = P->DstValue.Long;
|
||
Count = P->Shift;
|
||
if (Count != 0) {
|
||
if (P->DataType == LONG_DATA) {
|
||
if (Count == 1) {
|
||
P->Eflags.EFLAG_OF = High ^ (Low >> 31);
|
||
}
|
||
|
||
Carry = Low >> (Count - 1);
|
||
Low = (High << (32 - Count)) | (Low >> Count);
|
||
Sign = Low >> 31;
|
||
|
||
} else {
|
||
if (Count == 1) {
|
||
P->Eflags.EFLAG_OF = High ^ (Low >> 15);
|
||
}
|
||
|
||
Carry = Low >> (Count - 1);
|
||
Low = ((High << (16 - Count)) | (Low >> Count)) & 0xffff;
|
||
Sign = Low >> 15;
|
||
}
|
||
|
||
P->Eflags.EFLAG_CF = Carry;
|
||
P->Eflags.EFLAG_PF = XmComputeParity(Low);
|
||
P->Eflags.EFLAG_ZF = (Low == 0);
|
||
P->Eflags.EFLAG_SF = Sign;
|
||
}
|
||
|
||
XmStoreResult(P, Low);
|
||
return;
|
||
}
|