From e611b132f9b8abe35b362e5870b74bce94a1e58e Mon Sep 17 00:00:00 2001
From: Adam <you@example.com>
Date: Sat, 16 May 2020 20:51:50 -0700
Subject: initial commit

---
 private/ntos/nthals/x86new/mulops.c | 202 ++++++++++++++++++++++++++++++++++++
 1 file changed, 202 insertions(+)
 create mode 100644 private/ntos/nthals/x86new/mulops.c

(limited to 'private/ntos/nthals/x86new/mulops.c')

diff --git a/private/ntos/nthals/x86new/mulops.c b/private/ntos/nthals/x86new/mulops.c
new file mode 100644
index 000000000..cc020d392
--- /dev/null
+++ b/private/ntos/nthals/x86new/mulops.c
@@ -0,0 +1,202 @@
+/*++
+
+Copyright (c) 1994  Microsoft Corporation
+
+Module Name:
+
+    mulops.c
+
+Abstract:
+
+    This module implements the code to emulate the mul and imul opcodes.
+
+Author:
+
+    David N. Cutler (davec) 21-Sep-1994
+
+Environment:
+
+    Kernel mode only.
+
+Revision History:
+
+--*/
+
+#include "nthal.h"
+#include "emulate.h"
+
+VOID
+XmImulOp (
+    IN PRXM_CONTEXT P
+    )
+
+/*++
+
+Routine Description:
+
+    This function emulates an imul opcode with a single destination.
+
+Arguments:
+
+    P - Supplies a pointer to the emulation context structure.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    LARGE_INTEGER Product;
+    ULONG UpperEqual;
+
+    //
+    // Multiply the signed operands and store result.
+    //
+
+    if (P->DataType == BYTE_DATA) {
+        Product.QuadPart = Int32x32To64((LONG)((SCHAR)P->DstValue.Byte),
+                                        (LONG)((SCHAR)P->SrcValue.Byte));
+
+        XmStoreResult(P, Product.LowPart & 0xff);
+        UpperEqual = ((UCHAR)((Product.LowPart >> 8) & 0xff) !=
+                      (UCHAR)((SCHAR)Product.LowPart >> 7));
+
+    } else if (P->DataType == LONG_DATA) {
+        Product.QuadPart = Int32x32To64((LONG)P->DstValue.Long,
+                                        (LONG)P->SrcValue.Long);
+
+        XmStoreResult(P, Product.LowPart);
+        UpperEqual = (Product.HighPart != (LONG)Product.LowPart >> 31);
+
+    } else {
+        Product.QuadPart = Int32x32To64((LONG)((SHORT)P->DstValue.Word),
+                                        (LONG)((SHORT)P->SrcValue.Word));
+
+        XmStoreResult(P, Product.LowPart & 0xffff);
+        UpperEqual = ((USHORT)((Product.LowPart >> 16) & 0xffff) !=
+                      (USHORT)((SHORT)Product.LowPart >> 15));
+    }
+
+    P->Eflags.CF = UpperEqual;
+    P->Eflags.OF = UpperEqual;
+    return;
+}
+
+VOID
+XmImulxOp (
+    IN PRXM_CONTEXT P
+    )
+
+/*++
+
+Routine Description:
+
+    This function emulates an imul opcode with an extended destination.
+
+Arguments:
+
+    P - Supplies a pointer to the emulation context structure.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    LARGE_INTEGER Product;
+    ULONG UpperEqual;
+
+    //
+    // Multiply the signed operands and store the result and the extended
+    // result.
+    //
+
+    if (P->DataType == BYTE_DATA) {
+        Product.QuadPart = Int32x32To64((LONG)((SCHAR)P->DstValue.Byte),
+                                        (LONG)((SCHAR)P->SrcValue.Byte));
+
+        P->DataType = WORD_DATA;
+        XmStoreResult(P, Product.LowPart & 0xffff);
+        UpperEqual = (P->Gpr[AX].Xh != (UCHAR)((SCHAR)P->Gpr[AX].Xl >> 7));
+
+    } else if (P->DataType == LONG_DATA) {
+        Product.QuadPart = Int32x32To64((LONG)P->DstValue.Long,
+                                        (LONG)P->SrcValue.Long);
+
+        XmStoreResult(P, Product.LowPart);
+        P->DstLong = (UNALIGNED ULONG *)(&P->Gpr[EDX].Exx);
+        XmStoreResult(P, (ULONG)Product.HighPart);
+        UpperEqual = (Product.HighPart != (LONG)Product.LowPart >> 31);
+
+    } else {
+        Product.QuadPart = Int32x32To64((LONG)((SHORT)P->DstValue.Word),
+                                        (LONG)((SHORT)P->SrcValue.Word));
+
+        XmStoreResult(P, Product.LowPart & 0xffff);
+        P->DstLong = (UNALIGNED ULONG *)(&P->Gpr[DX].Exx);
+        XmStoreResult(P, Product.LowPart >> 16);
+        UpperEqual = (P->Gpr[DX].Xx != (USHORT)((SHORT)P->Gpr[AX].Xx >> 15));
+    }
+
+    P->Eflags.CF = UpperEqual;
+    P->Eflags.OF = UpperEqual;
+    return;
+}
+
+VOID
+XmMulOp (
+    IN PRXM_CONTEXT P
+    )
+
+/*++
+
+Routine Description:
+
+    This function emulates a mul opcode.
+
+Arguments:
+
+    P - Supplies a pointer to the emulation context structure.
+
+Return Value:
+
+    None.
+
+--*/
+
+{
+
+    ULARGE_INTEGER Product;
+    ULONG UpperZero;
+
+    //
+    // Multiply the unsigned operands and store result.
+    //
+
+    Product.QuadPart = UInt32x32To64(P->DstValue.Long, P->SrcValue.Long);
+    if (P->DataType == BYTE_DATA) {
+        P->DataType = WORD_DATA;
+        XmStoreResult(P, Product.LowPart);
+        UpperZero = (P->Gpr[AX].Xh != 0);
+
+    } else if (P->DataType == LONG_DATA) {
+        XmStoreResult(P, Product.LowPart);
+        P->DstLong = (UNALIGNED ULONG *)(&P->Gpr[EDX].Exx);
+        XmStoreResult(P, Product.HighPart);
+        UpperZero = (Product.HighPart != 0);
+
+    } else {
+        XmStoreResult(P, Product.LowPart & 0xffff);
+        P->DstLong = (UNALIGNED ULONG *)(&P->Gpr[DX].Exx);
+        XmStoreResult(P, Product.LowPart >> 16);
+        UpperZero = (P->Gpr[DX].Xx != 0);
+    }
+
+    P->Eflags.CF = UpperZero;
+    P->Eflags.OF = UpperZero;
+    return;
+}
-- 
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