1 files changed, 496 insertions, 0 deletions

diff --git a/private/ntos/nthals/x86new/stringop.c b/private/ntos/nthals/x86new/stringop.c
new file mode 100644
index 000000000..61fc6998a
--- /dev/null
+++ b/private/ntos/nthals/x86new/stringop.c
@@ -0,0 +1,496 @@
+/*++
+
+Copyright (c) 1994  Microsoft Corporation
+
+Module Name:
+
+    stringop.c
+
+Abstract:
+
+    This module implements the code to emulate the string opcodes.
+
+Author:
+
+    David N. Cutler (davec) 7-Nov-1994
+
+Environment:
+
+    Kernel mode only.
+
+Revision History:
+
+--*/
+
+#include "nthal.h"
+#include "emulate.h"
+
+//
+// Define forward referenced prototypes.
+//
+
+VOID
+XmCompareOperands (
+    IN PRXM_CONTEXT P
+    );
+
+VOID
+XmCmpsOp (
+    IN PRXM_CONTEXT P
+    )
+
+/*++
+
+Routine Description:
+
+    This function emulates a cmpsb/w/d opcode.
+
+Arguments:
+
+    P - Supplies a pointer to the emulation context structure.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    ULONG Count;
+
+    //
+    // If a repeat prefix is active, then the loop count is specified
+    // by eCX. Otherwise, the loop count is one.
+    //
+
+    Count = 1;
+    if (P->RepeatPrefixActive != FALSE) {
+        if (P->OpaddrPrefixActive != FALSE) {
+            Count = P->Gpr[ECX].Exx;
+
+        } else {
+            Count = P->Gpr[CX].Xx;
+        }
+    }
+
+    //
+    // Compare items from source and destination.
+    //
+
+    while (Count != 0) {
+
+        //
+        // Set source and destination values.
+        //
+
+        XmSetSourceValue(P, XmGetStringAddress(P, P->DataSegment, ESI));
+        XmSetDestinationValue(P, XmGetStringAddress(P, ES, EDI));
+
+        //
+        // Compare source with destination operand and decrement loop count.
+        // If ZF is not equal to the repeat Z flag condition, then terminate
+        // the loop.
+        //
+
+        XmCompareOperands(P);
+        Count -= 1;
+        if (P->Eflags.ZF != P->RepeatZflag) {
+            break;
+        }
+    }
+
+    //
+    // If a repeat prefix is active, then set the final count value.
+    //
+
+    if (P->RepeatPrefixActive != FALSE) {
+        if (P->OpaddrPrefixActive != FALSE) {
+            P->Gpr[ECX].Exx = Count;
+
+        } else {
+            P->Gpr[CX].Xx = (USHORT)Count;
+        }
+    }
+
+    return;
+}
+
+VOID
+XmLodsOp (
+    IN PRXM_CONTEXT P
+    )
+
+/*++
+
+Routine Description:
+
+    This function emulates a lodsb/w/d opcode.
+
+Arguments:
+
+    P - Supplies a pointer to the emulation context structure.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    ULONG Count;
+
+    //
+    // If a repeat prefix is active, then the loop count is specified
+    // by eCX. Otherwise, the loop count is one.
+    //
+
+    Count = 1;
+    if (P->RepeatPrefixActive != FALSE) {
+        if (P->OpaddrPrefixActive != FALSE) {
+            Count = P->Gpr[ECX].Exx;
+            P->Gpr[ECX].Exx = 0;
+
+        } else {
+            Count = P->Gpr[CX].Xx;
+            P->Gpr[CX].Xx = 0;
+        }
+    }
+
+    //
+    // Set destination address.
+    //
+
+    P->DstLong = (ULONG UNALIGNED *)&P->Gpr[EAX].Exx;
+
+    //
+    // Move items from source to destination.
+    //
+
+    while (Count != 0) {
+
+        //
+        // Set source value and store result.
+        //
+
+        XmSetSourceValue(P, XmGetStringAddress(P, P->DataSegment, ESI));
+        XmStoreResult(P, P->SrcValue.Long);
+        Count -= 1;
+    }
+
+    return;
+}
+
+VOID
+XmMovsOp (
+    IN PRXM_CONTEXT P
+    )
+
+/*++
+
+Routine Description:
+
+    This function emulates a movsb/w/d opcode.
+
+Arguments:
+
+    P - Supplies a pointer to the emulation context structure.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    ULONG Count;
+
+    //
+    // If a repeat prefix is active, then the loop count is specified
+    // by eCX. Otherwise, the loop count is one.
+    //
+
+    Count = 1;
+    if (P->RepeatPrefixActive != FALSE) {
+        if (P->OpaddrPrefixActive != FALSE) {
+            Count = P->Gpr[ECX].Exx;
+            P->Gpr[ECX].Exx = 0;
+
+        } else {
+            Count = P->Gpr[CX].Xx;
+            P->Gpr[CX].Xx = 0;
+        }
+    }
+
+    //
+    // Move items from source to destination.
+    //
+
+    while (Count != 0) {
+
+        //
+        // Set source value, set destination address, and store result.
+        //
+
+        XmSetSourceValue(P, XmGetStringAddress(P, P->DataSegment, ESI));
+        P->DstLong = (ULONG UNALIGNED *)XmGetStringAddress(P, ES, EDI);
+        XmStoreResult(P, P->SrcValue.Long);
+        Count -= 1;
+    }
+
+    return;
+}
+
+VOID
+XmScasOp (
+    IN PRXM_CONTEXT P
+    )
+
+/*++
+
+Routine Description:
+
+    This function emulates a scasb/w/d opcode.
+
+Arguments:
+
+    P - Supplies a pointer to the emulation context structure.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    ULONG Count;
+
+    //
+    // If a repeat prefix is active, then the loop count is specified
+    // by eCX. Otherwise, the loop count is one.
+    //
+
+    Count = 1;
+    if (P->RepeatPrefixActive != FALSE) {
+        if (P->OpaddrPrefixActive != FALSE) {
+            Count = P->Gpr[ECX].Exx;
+
+        } else {
+            Count = P->Gpr[CX].Xx;
+        }
+    }
+
+    //
+    // Set source value.
+    //
+
+    XmSetSourceValue(P, (PVOID)&P->Gpr[EAX].Exx);
+
+    //
+    // Compare items from source and destination.
+    //
+
+    while (Count != 0) {
+
+        //
+        // Set destination value.
+        //
+
+        XmSetDestinationValue(P, XmGetStringAddress(P, ES, EDI));
+
+        //
+        // Compare source with destination operand and decrement loop count.
+        // If ZF is not equal to the repeat Z flag condition, then terminate
+        // the loop.
+        //
+
+        XmCompareOperands(P);
+        Count -= 1;
+        if (P->Eflags.ZF != P->RepeatZflag) {
+            break;
+        }
+    }
+
+    //
+    // If a repeat prefix is active, then set the final count value.
+    //
+
+    if (P->RepeatPrefixActive != FALSE) {
+        if (P->OpaddrPrefixActive != FALSE) {
+            P->Gpr[ECX].Exx = Count;
+
+        } else {
+            P->Gpr[CX].Xx = (USHORT)Count;
+        }
+    }
+
+    return;
+}
+
+VOID
+XmStosOp (
+    IN PRXM_CONTEXT P
+    )
+
+/*++
+
+Routine Description:
+
+    This function emulates a stosb/w/d opcode.
+
+Arguments:
+
+    P - Supplies a pointer to the emulation context structure.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    ULONG Count;
+
+    //
+    // If a repeat prefix is active, then the loop count is specified
+    // by eCX. Otherwise, the loop count is one.
+    //
+
+    Count = 1;
+    if (P->RepeatPrefixActive != FALSE) {
+        if (P->OpaddrPrefixActive != FALSE) {
+            Count = P->Gpr[ECX].Exx;
+            P->Gpr[ECX].Exx = 0;
+
+        } else {
+            Count = P->Gpr[CX].Xx;
+            P->Gpr[CX].Xx = 0;
+        }
+    }
+
+    //
+    // Set source value.
+    //
+
+    XmSetSourceValue(P, (PVOID)&P->Gpr[EAX].Exx);
+
+    //
+    // Move items from source to destination.
+    //
+
+    while (Count != 0) {
+
+        //
+        // Set destination address and store result.
+        //
+
+        P->DstLong = (ULONG UNALIGNED *)XmGetStringAddress(P, ES, EDI);
+        XmStoreResult(P, P->SrcValue.Long);
+        Count -= 1;
+    }
+
+    return;
+}
+
+VOID
+XmCompareOperands (
+    IN PRXM_CONTEXT P
+    )
+
+/*++
+
+Routine Description:
+
+    This function compares two operands and computes the resulting condition
+    codes.
+
+Arguments:
+
+    P - Supplies a pointer to the emulation context structure.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    ULONG CarryFlag;
+    ULONG OverflowFlag;
+    ULONG SignFlag;
+    ULONG ZeroFlag;
+    union {
+        UCHAR ResultByte;
+        ULONG ResultLong;
+        USHORT ResultWord;
+    } u;
+
+    //
+    // Switch on data type.
+    //
+
+    switch (P->DataType) {
+
+        //
+        // The operation datatype is byte.
+        //
+
+    case BYTE_DATA:
+        CarryFlag = (P->SrcValue.Byte < P->DstValue.Byte);
+        u.ResultByte = P->SrcValue.Byte - P->DstValue.Byte;
+        OverflowFlag = (((u.ResultByte ^ P->SrcValue.Byte) &
+                        (u.ResultByte ^ P->DstValue.Byte)) >> 7) & 0x1;
+
+        SignFlag = (u.ResultByte >> 7) & 0x1;
+        ZeroFlag = (u.ResultByte == 0);
+        u.ResultLong = u.ResultByte;
+        break;
+
+        //
+        // The operation datatype is word.
+        //
+
+    case WORD_DATA:
+        CarryFlag = (P->SrcValue.Word < P->DstValue.Word);
+        u.ResultWord = P->SrcValue.Word - P->DstValue.Word;
+        OverflowFlag = (((u.ResultWord ^ P->SrcValue.Word) &
+                        (u.ResultWord ^ P->DstValue.Word)) >> 15) & 0x1;
+
+        SignFlag = (u.ResultWord >> 15) & 0x1;
+        ZeroFlag = (u.ResultWord == 0);
+        u.ResultLong = u.ResultWord;
+        break;
+
+        //
+        // The operation datatype is long.
+        //
+
+    case LONG_DATA:
+        CarryFlag = (P->SrcValue.Long < P->DstValue.Long);
+        u.ResultLong = P->SrcValue.Long - P->DstValue.Long;
+        OverflowFlag = (((u.ResultLong ^ P->SrcValue.Long) &
+                        (u.ResultLong ^ P->DstValue.Long)) >> 31) & 0x1;
+
+        SignFlag = (u.ResultLong >> 31) & 0x1;
+        ZeroFlag = (u.ResultLong == 0);
+        break;
+    }
+
+    //
+    // Compute auxilary carry flag, parity flag, and store all flags in
+    // the flags register.
+    //
+
+    P->Eflags.CF = CarryFlag;
+    P->Eflags.PF = XmComputeParity(u.ResultLong);
+    P->Eflags.AF = ((P->DstValue.Byte & 0xf) + (P->SrcValue.Byte & 0xf)) >> 4;
+    P->Eflags.ZF = ZeroFlag;
+    P->Eflags.SF = SignFlag;
+    P->Eflags.OF = OverflowFlag;
+    return;
+}