* Sync up to trunk head (r65298).

[reactos.git] / lib / fast486 / extraops.c

diff --git a/lib/fast486/extraops.c b/lib/fast486/extraops.c
index f9fe386..1f2fc72 100644 (file)
--- a/lib/fast486/extraops.c
+++ b/lib/fast486/extraops.c
@@ -2,7 +2,7 @@
  * Fast486 386/486 CPU Emulation Library
  * extraops.c
  *
- * Copyright (C) 2013 Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
+ * Copyright (C) 2014 Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -37,134 +37,135 @@
 FAST486_OPCODE_HANDLER_PROC
 Fast486ExtendedHandlers[FAST486_NUM_OPCODE_HANDLERS] =
 {
-    Fast486OpcodeGroup0F00,
-    Fast486OpcodeGroup0F01,
-    Fast486ExtOpcodeLar,
-    Fast486ExtOpcodeLsl,
-    NULL, // Invalid
-    NULL, // Invalid
-    Fast486ExtOpcodeClts,
-    NULL, // Invalid
-    NULL, // TODO: OPCODE 0x08 NOT IMPLEMENTED
-    NULL, // TODO: OPCODE 0x09 NOT IMPLEMENTED
-    NULL, // Invalid
-    NULL, // Reserved (UD1)
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    Fast486ExtOpcodeStoreControlReg,
-    Fast486ExtOpcodeStoreDebugReg,
-    Fast486ExtOpcodeLoadControlReg,
-    Fast486ExtOpcodeLoadDebugReg,
-    NULL, // TODO: OPCODE 0x24 NOT IMPLEMENTED
-    NULL, // Invalid
-    NULL, // TODO: OPCODE 0x26 NOT IMPLEMENTED
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
+    Fast486ExtOpcodeGroup0F00,          /* 0x00 - 0x01 */
+    Fast486ExtOpcodeGroup0F01,
+    Fast486ExtOpcodeLar,                /* 0x02 */
+    Fast486ExtOpcodeLsl,                /* 0x03 */
+    Fast486ExtOpcodeInvalid,            /* 0x04 - 0x05 */   // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeClts,               /* 0x06 */
+    Fast486ExtOpcodeInvalid,            /* 0x07 */          // Invalid
+    Fast486ExtOpcodeUnimplemented, // TODO: OPCODE 0x08 NOT IMPLEMENTED
+    Fast486ExtOpcodeUnimplemented, // TODO: OPCODE 0x09 NOT IMPLEMENTED
+    Fast486ExtOpcodeInvalid,            /* 0x0A */          // Invalid
+    Fast486ExtOpcode0F0B,               /* 0x0B */          // Reserved (UD2)
+    Fast486ExtOpcodeInvalid,            /* 0x0C - 0x1F */   // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeStoreControlReg,    /* 0x20 */
+    Fast486ExtOpcodeStoreDebugReg,      /* 0x21 */
+    Fast486ExtOpcodeLoadControlReg,     /* 0x22 */
+    Fast486ExtOpcodeLoadDebugReg,       /* 0x23 */
+    Fast486ExtOpcodeUnimplemented, // TODO: OPCODE 0x24 NOT IMPLEMENTED
+    Fast486ExtOpcodeInvalid,            /* 0x25 */          // Invalid
+    Fast486ExtOpcodeUnimplemented, // TODO: OPCODE 0x26 NOT IMPLEMENTED
+    Fast486ExtOpcodeInvalid,            /* 0x27 - 0x7F */   // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeConditionalJmp,     /* 0x80 - 0x8F */
     Fast486ExtOpcodeConditionalJmp,
     Fast486ExtOpcodeConditionalJmp,
     Fast486ExtOpcodeConditionalJmp,
@@ -180,8 +181,7 @@ Fast486ExtendedHandlers[FAST486_NUM_OPCODE_HANDLERS] =
     Fast486ExtOpcodeConditionalJmp,
     Fast486ExtOpcodeConditionalJmp,
     Fast486ExtOpcodeConditionalJmp,
-    Fast486ExtOpcodeConditionalJmp,
-    Fast486ExtOpcodeConditionalSet,
+    Fast486ExtOpcodeConditionalSet,     /* 0x90 - 0x9F */
     Fast486ExtOpcodeConditionalSet,
     Fast486ExtOpcodeConditionalSet,
     Fast486ExtOpcodeConditionalSet,
@@ -197,47 +197,47 @@ Fast486ExtendedHandlers[FAST486_NUM_OPCODE_HANDLERS] =
     Fast486ExtOpcodeConditionalSet,
     Fast486ExtOpcodeConditionalSet,
     Fast486ExtOpcodeConditionalSet,
-    Fast486ExtOpcodePushFs,
-    Fast486ExtOpcodePopFs,
-    NULL, // Invalid
-    Fast486ExtOpcodeBitTest,
-    Fast486ExtOpcodeShld,
+    Fast486ExtOpcodePushFs,             /* 0xA0 */
+    Fast486ExtOpcodePopFs,              /* 0xA1 */
+    Fast486ExtOpcodeInvalid,            /* 0xA2 */          // Invalid
+    Fast486ExtOpcodeBitTest,            /* 0xA3 */
+    Fast486ExtOpcodeShld,               /* 0xA4 - 0xA5 */
     Fast486ExtOpcodeShld,
-    NULL, // Invalid
-    NULL, // Invalid
-    Fast486ExtOpcodePushGs,
+    Fast486ExtOpcodeInvalid,            /* 0xA6 - 0xA7 */   // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodePushGs,             /* 0xA8 - 0xA9 */
     Fast486ExtOpcodePopGs,
-    NULL, // Invalid
-    Fast486ExtOpcodeBts,
+    Fast486ExtOpcodeInvalid,            /* 0xAA */          // Invalid
+    Fast486ExtOpcodeBts,                /* 0xAB */
+    Fast486ExtOpcodeShrd,               /* 0xAC - 0xAD */
     Fast486ExtOpcodeShrd,
-    Fast486ExtOpcodeShrd,
-    NULL, // Invalid
-    Fast486ExtOpcodeImul,
-    Fast486ExtOpcodeCmpXchgByte,
-    Fast486ExtOpcodeCmpXchg,
-    Fast486ExtOpcodeLss,
-    Fast486ExtOpcodeBtr,
-    Fast486ExtOpcodeLfsLgs,
+    Fast486ExtOpcodeInvalid,            /* 0xAE */          // Invalid
+    Fast486ExtOpcodeImul,               /* 0xAF */
+    Fast486ExtOpcodeCmpXchgByte,        /* 0xB0 */
+    Fast486ExtOpcodeCmpXchg,            /* 0xB1 */
+    Fast486ExtOpcodeLss,                /* 0xB2 */
+    Fast486ExtOpcodeBtr,                /* 0xB3 */
+    Fast486ExtOpcodeLfsLgs,             /* 0xB4 - 0xB5 */
     Fast486ExtOpcodeLfsLgs,
-    Fast486ExtOpcodeMovzxByte,
+    Fast486ExtOpcodeMovzxByte,          /* 0xB6 - 0xB7 */
     Fast486ExtOpcodeMovzxWord,
-    NULL, // Invalid
-    Fast486OpcodeGroup0FB9,
-    Fast486OpcodeGroup0FBA,
-    Fast486ExtOpcodeBtc,
-    Fast486ExtOpcodeBsf,
-    Fast486ExtOpcodeBsr,
-    Fast486ExtOpcodeMovsxByte,
+    Fast486ExtOpcodeInvalid,            /* 0xB8 */          // Invalid
+    Fast486ExtOpcodeGroup0FB9,          /* 0xB9 */
+    Fast486ExtOpcodeGroup0FBA,          /* 0xBA */
+    Fast486ExtOpcodeBtc,                /* 0xBB */
+    Fast486ExtOpcodeBsf,                /* 0xBC */
+    Fast486ExtOpcodeBsr,                /* 0xBD */
+    Fast486ExtOpcodeMovsxByte,          /* 0xBE - 0xBF */
     Fast486ExtOpcodeMovsxWord,
-    Fast486ExtOpcodeXaddByte,
+    Fast486ExtOpcodeXaddByte,           /* 0xC0 - 0xC1 */
     Fast486ExtOpcodeXadd,
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    Fast486ExtOpcodeBswap,
+    Fast486ExtOpcodeInvalid,            /* 0xC2 - 0xC7 */   // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeBswap,              /* 0xC8 - 0xCF */
     Fast486ExtOpcodeBswap,
     Fast486ExtOpcodeBswap,
     Fast486ExtOpcodeBswap,
@@ -245,62 +245,82 @@ Fast486ExtendedHandlers[FAST486_NUM_OPCODE_HANDLERS] =
     Fast486ExtOpcodeBswap,
     Fast486ExtOpcodeBswap,
     Fast486ExtOpcodeBswap,
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
-    NULL, // Invalid
+    Fast486ExtOpcodeInvalid,            /* 0xD0 - 0xFF */   // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
+    Fast486ExtOpcodeInvalid,                                // Invalid
 };
 
 /* PUBLIC FUNCTIONS ***********************************************************/
 
+FAST486_OPCODE_HANDLER(Fast486ExtOpcodeInvalid)
+{
+    DPRINT1("FAST486 -- Extended opcode 0x%02X is INVALID!\n", Opcode);
+    Fast486Exception(State, FAST486_EXCEPTION_UD);
+    return;
+}
+
+FAST486_OPCODE_HANDLER(Fast486ExtOpcodeUnimplemented)
+{
+    DPRINT1("FAST486 -- Extended opcode 0x%02X is UNIMPLEMENTED\n", Opcode);
+    // Fast486Exception(State, FAST486_EXCEPTION_UD);
+}
+
+FAST486_OPCODE_HANDLER(Fast486ExtOpcode0F0B)
+{
+    /* Reserved opcode (UD2) */
+    Fast486Exception(State, FAST486_EXCEPTION_UD);
+}
+
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLar)
 {
     BOOLEAN OperandSize, AddressSize;
     FAST486_MOD_REG_RM ModRegRm;
+    BOOLEAN Valid;
     USHORT Selector;
     FAST486_GDT_ENTRY GdtEntry;
     DWORD AccessRights;
@@ -312,7 +332,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLar)
     {
         /* Not recognized */
         Fast486Exception(State, FAST486_EXCEPTION_UD);
-        return FALSE;
+        return;
     }
 
     NO_LOCK_PREFIX();
@@ -323,7 +343,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLar)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (OperandSize)
@@ -334,7 +354,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLar)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     
         Selector = LOWORD(Value);
@@ -345,49 +365,20 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLar)
         if (!Fast486ReadModrmWordOperands(State, &ModRegRm, NULL, &Selector))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     }
 
-    if (!(Selector & SEGMENT_TABLE_INDICATOR))
+    if (!Fast486ReadDescriptorEntry(State, Selector, &Valid, &GdtEntry))
     {
-        /* Check if the GDT contains the entry */
-        if (GET_SEGMENT_INDEX(Selector) >= (State->Gdtr.Size + 1))
-        {
-            State->Flags.Zf = FALSE;
-            return TRUE;
-        }
-
-        /* Read the GDT */
-        if (!Fast486ReadLinearMemory(State,
-                                     State->Gdtr.Address
-                                     + GET_SEGMENT_INDEX(Selector),
-                                     &GdtEntry,
-                                     sizeof(GdtEntry)))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        /* Exception occurred */
+        return;
     }
-    else
-    {
-        /* Check if the LDT contains the entry */
-        if (GET_SEGMENT_INDEX(Selector) >= (State->Ldtr.Limit + 1))
-        {
-            State->Flags.Zf = FALSE;
-            return TRUE;
-        }
 
-        /* Read the LDT */
-        if (!Fast486ReadLinearMemory(State,
-                                     State->Ldtr.Base
-                                     + GET_SEGMENT_INDEX(Selector),
-                                     &GdtEntry,
-                                     sizeof(GdtEntry)))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+    if (!Valid)
+    {
+        State->Flags.Zf = FALSE;
+        return;
     }
 
     /* Privilege check */
@@ -395,7 +386,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLar)
         || (Fast486GetCurrentPrivLevel(State) > GdtEntry.Dpl))
     {
         State->Flags.Zf = FALSE;
-        return TRUE;
+        return;
     }
 
     /* Set ZF */
@@ -405,30 +396,15 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLar)
     AccessRights = ((PDWORD)&GdtEntry)[1] & 0x00F0FF00;
 
     /* Return the access rights */
-    if (OperandSize)
-    {
-        if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, AccessRights))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
-    }
-    else
-    {
-        if (!Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, LOWORD(AccessRights)))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
-    }
-
-    return TRUE;
+    if (OperandSize) Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, AccessRights);
+    else Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, LOWORD(AccessRights));
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLsl)
 {
     BOOLEAN OperandSize, AddressSize;
     FAST486_MOD_REG_RM ModRegRm;
+    BOOLEAN Valid;
     USHORT Selector;
     ULONG Limit;
     FAST486_GDT_ENTRY GdtEntry;
@@ -440,7 +416,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLsl)
     {
         /* Not recognized */
         Fast486Exception(State, FAST486_EXCEPTION_UD);
-        return FALSE;
+        return;
     }
 
     NO_LOCK_PREFIX();
@@ -451,7 +427,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLsl)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (OperandSize)
@@ -462,7 +438,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLsl)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     
         Selector = LOWORD(Value);
@@ -473,49 +449,20 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLsl)
         if (!Fast486ReadModrmWordOperands(State, &ModRegRm, NULL, &Selector))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     }
 
-    if (!(Selector & SEGMENT_TABLE_INDICATOR))
+    if (!Fast486ReadDescriptorEntry(State, Selector, &Valid, &GdtEntry))
     {
-        /* Check if the GDT contains the entry */
-        if (GET_SEGMENT_INDEX(Selector) >= (State->Gdtr.Size + 1))
-        {
-            State->Flags.Zf = FALSE;
-            return TRUE;
-        }
-
-        /* Read the GDT */
-        if (!Fast486ReadLinearMemory(State,
-                                     State->Gdtr.Address
-                                     + GET_SEGMENT_INDEX(Selector),
-                                     &GdtEntry,
-                                     sizeof(GdtEntry)))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        /* Exception occurred */
+        return;
     }
-    else
-    {
-        /* Check if the LDT contains the entry */
-        if (GET_SEGMENT_INDEX(Selector) >= (State->Ldtr.Limit + 1))
-        {
-            State->Flags.Zf = FALSE;
-            return TRUE;
-        }
 
-        /* Read the LDT */
-        if (!Fast486ReadLinearMemory(State,
-                                     State->Ldtr.Base
-                                     + GET_SEGMENT_INDEX(Selector),
-                                     &GdtEntry,
-                                     sizeof(GdtEntry)))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+    if (!Valid)
+    {
+        State->Flags.Zf = FALSE;
+        return;
     }
 
     /* Privilege check */
@@ -523,36 +470,24 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLsl)
         || (Fast486GetCurrentPrivLevel(State) > GdtEntry.Dpl))
     {
         State->Flags.Zf = FALSE;
-        return TRUE;
+        return;
     }
 
     /* Calculate the limit */
     Limit = GdtEntry.Limit | (GdtEntry.LimitHigh << 16);
-    if (GdtEntry.Granularity) Limit <<= 12;
-
-    /* Set ZF */
-    State->Flags.Zf = TRUE;
 
-    if (OperandSize)
-    {
-        /* Return the limit */
-        if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, Limit))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
-    }
-    else
+    if (GdtEntry.Granularity)
     {
-        /* Return the limit */
-        if (!Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, LOWORD(Limit)))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        Limit <<= 12;
+        Limit |= 0x00000FFF;
     }
 
-    return TRUE;
+    /* Set ZF */
+    State->Flags.Zf = TRUE;
+
+    /* Return the limit */
+    if (OperandSize) Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, Limit);
+    else Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, LOWORD(Limit));
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeClts)
@@ -563,13 +498,11 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeClts)
     if (Fast486GetCurrentPrivLevel(State) != 0)
     {
         Fast486Exception(State, FAST486_EXCEPTION_GP);
-        return FALSE;
+        return;
     }
 
     /* Clear the task switch bit */
     State->ControlRegisters[FAST486_REG_CR0] &= ~FAST486_CR0_TS;
-
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeStoreControlReg)
@@ -584,21 +517,21 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeStoreControlReg)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* The current privilege level must be zero */
     if (Fast486GetCurrentPrivLevel(State) != 0)
     {
         Fast486Exception(State, FAST486_EXCEPTION_GP);
-        return FALSE;
+        return;
     }
 
     if ((ModRegRm.Register == 1) || (ModRegRm.Register > 3))
     {
         /* CR1, CR4, CR5, CR6 and CR7 don't exist */
         Fast486Exception(State, FAST486_EXCEPTION_UD);
-        return FALSE;
+        return;
     }
 
     if (ModRegRm.Register != 0)
@@ -609,9 +542,6 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeStoreControlReg)
 
     /* Store the value of the control register */
     State->GeneralRegs[ModRegRm.SecondRegister].Long = State->ControlRegisters[ModRegRm.Register];
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeStoreDebugReg)
@@ -626,14 +556,14 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeStoreDebugReg)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* The current privilege level must be zero */
     if (Fast486GetCurrentPrivLevel(State) != 0)
     {
         Fast486Exception(State, FAST486_EXCEPTION_GP);
-        return FALSE;
+        return;
     }
 
     if ((ModRegRm.Register == 6) || (ModRegRm.Register == 7))
@@ -646,14 +576,11 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeStoreDebugReg)
     {
         /* Disallow access to debug registers */
         Fast486Exception(State, FAST486_EXCEPTION_GP);
-        return FALSE;
+        return;
     }
 
     /* Store the value of the debug register */
     State->GeneralRegs[ModRegRm.SecondRegister].Long = State->DebugRegisters[ModRegRm.Register];
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLoadControlReg)
@@ -669,21 +596,21 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLoadControlReg)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* The current privilege level must be zero */
     if (Fast486GetCurrentPrivLevel(State) != 0)
     {
         Fast486Exception(State, FAST486_EXCEPTION_GP);
-        return FALSE;
+        return;
     }
 
     if ((ModRegRm.Register == 1) || (ModRegRm.Register > 3))
     {
         /* CR1, CR4, CR5, CR6 and CR7 don't exist */
         Fast486Exception(State, FAST486_EXCEPTION_UD);
-        return FALSE;
+        return;
     }
 
     if (ModRegRm.Register != 0)
@@ -704,15 +631,23 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLoadControlReg)
         {
             /* Invalid value */
             Fast486Exception(State, FAST486_EXCEPTION_GP);
-            return FALSE;
+            return;
         }
     }
 
+#ifndef FAST486_NO_PREFETCH
+    /* Changing CR0 or CR3 can interfere with prefetching (because of paging) */
+    State->PrefetchValid = FALSE;
+#endif
+
+    if (State->Tlb && (ModRegRm.Register == (INT)FAST486_REG_CR3))
+    {
+        /* Flush the TLB */
+        RtlZeroMemory(State->Tlb, NUM_TLB_ENTRIES * sizeof(ULONG));
+    }
+
     /* Load a value to the control register */
     State->ControlRegisters[ModRegRm.Register] = Value;
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLoadDebugReg)
@@ -727,14 +662,14 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLoadDebugReg)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* The current privilege level must be zero */
     if (Fast486GetCurrentPrivLevel(State) != 0)
     {
         Fast486Exception(State, FAST486_EXCEPTION_GP);
-        return FALSE;
+        return;
     }
 
     if ((ModRegRm.Register == 6) || (ModRegRm.Register == 7))
@@ -747,7 +682,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLoadDebugReg)
     {
         /* Disallow access to debug registers */
         Fast486Exception(State, FAST486_EXCEPTION_GP);
-        return FALSE;
+        return;
     }
 
     /* Load a value to the debug register */
@@ -763,15 +698,12 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLoadDebugReg)
         /* The reserved bits are 0 */
         State->DebugRegisters[ModRegRm.Register] &= ~FAST486_DR5_RESERVED;
     }
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodePushFs)
 {
     /* Call the internal API */
-    return Fast486StackPush(State, State->SegmentRegs[FAST486_REG_FS].Selector);
+    Fast486StackPush(State, State->SegmentRegs[FAST486_REG_FS].Selector);
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodePopFs)
@@ -781,11 +713,11 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodePopFs)
     if (!Fast486StackPop(State, &NewSelector))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Call the internal API */
-    return Fast486LoadSegment(State, FAST486_REG_FS, LOWORD(NewSelector));
+    Fast486LoadSegment(State, FAST486_REG_FS, LOWORD(NewSelector));
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBitTest)
@@ -807,7 +739,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBitTest)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Get the bit number */
@@ -834,7 +766,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBitTest)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Set CF to the bit value */
@@ -848,15 +780,12 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBitTest)
         if (!Fast486ReadModrmWordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Set CF to the bit value */
         State->Flags.Cf = (Value >> BitNumber) & 1;
     }
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShld)
@@ -876,7 +805,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShld)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (Opcode == 0xA4)
@@ -885,7 +814,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShld)
         if (!Fast486FetchByte(State, &Count))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     }
     else
@@ -898,7 +827,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShld)
     Count &= 0x1F;
 
     /* Do nothing if the count is zero */
-    if (Count == 0) return TRUE;
+    if (Count == 0) return;
 
     if (OperandSize)
     {
@@ -907,7 +836,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShld)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, &Source, &Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Calculate the result */
@@ -922,7 +851,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShld)
         State->Flags.Pf = Fast486CalculateParity(Result);
 
         /* Write back the result */
-        return Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Result);
+        Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Result);
     }
     else
     {
@@ -932,7 +861,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShld)
         if (!Fast486ReadModrmWordOperands(State, &ModRegRm, &Source, &Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         DoubleSource = Source | (Source << 16);
@@ -951,14 +880,14 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShld)
         State->Flags.Pf = Fast486CalculateParity(Result);
 
         /* Write back the result */
-        return Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Result);
+        Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Result);
     }
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodePushGs)
 {
     /* Call the internal API */
-    return Fast486StackPush(State, State->SegmentRegs[FAST486_REG_GS].Selector);
+    Fast486StackPush(State, State->SegmentRegs[FAST486_REG_GS].Selector);
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodePopGs)
@@ -968,11 +897,11 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodePopGs)
     if (!Fast486StackPop(State, &NewSelector))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Call the internal API */
-    return Fast486LoadSegment(State, FAST486_REG_GS, LOWORD(NewSelector));
+    Fast486LoadSegment(State, FAST486_REG_GS, LOWORD(NewSelector));
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBts)
@@ -994,7 +923,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBts)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Get the bit number */
@@ -1021,7 +950,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBts)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Set CF to the bit value */
@@ -1031,11 +960,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBts)
         Value |= 1 << BitNumber;
 
         /* Write back the result */
-        if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value);
     }
     else
     {
@@ -1045,7 +970,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBts)
         if (!Fast486ReadModrmWordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Set CF to the bit value */
@@ -1055,15 +980,8 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBts)
         Value |= 1 << BitNumber;
 
         /* Write back the result */
-        if (!Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Value))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Value);
     }
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShrd)
@@ -1083,7 +1001,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShrd)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (Opcode == 0xAC)
@@ -1092,7 +1010,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShrd)
         if (!Fast486FetchByte(State, &Count))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     }
     else
@@ -1105,7 +1023,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShrd)
     Count &= 0x1F;
 
     /* Do nothing if the count is zero */
-    if (Count == 0) return TRUE;
+    if (Count == 0) return;
 
     if (OperandSize)
     {
@@ -1114,7 +1032,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShrd)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, &Source, &Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Calculate the result */
@@ -1129,7 +1047,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShrd)
         State->Flags.Pf = Fast486CalculateParity(Result);
 
         /* Write back the result */
-        return Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Result);
+        Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Result);
     }
     else
     {
@@ -1138,7 +1056,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShrd)
         if (!Fast486ReadModrmWordOperands(State, &ModRegRm, &Source, &Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Calculate the result */
@@ -1157,7 +1075,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeShrd)
         State->Flags.Pf = Fast486CalculateParity(Result);
 
         /* Write back the result */
-        return Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Result);
+        Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Result);
     }
 }
 
@@ -1175,7 +1093,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeImul)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (OperandSize)
@@ -1190,7 +1108,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeImul)
                                            (PULONG)&Source))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Calculate the result */
@@ -1200,7 +1118,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeImul)
         State->Flags.Cf = State->Flags.Of = ((Result < -2147483648LL) || (Result > 2147483647LL));
 
         /* Write back the result */
-        return Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, (ULONG)((LONG)Result));
+        Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, (ULONG)((LONG)Result));
     }
     else
     {
@@ -1214,7 +1132,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeImul)
                                           (PUSHORT)&Source))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Calculate the result */
@@ -1224,7 +1142,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeImul)
         State->Flags.Cf = State->Flags.Of = ((Result < -32768) || (Result > 32767));
 
         /* Write back the result */
-        return Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, (USHORT)((SHORT)Result));
+        Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, (USHORT)((SHORT)Result));
     }
 }
 
@@ -1241,14 +1159,14 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeCmpXchgByte)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Read the operands */
     if (!Fast486ReadModrmByteOperands(State, &ModRegRm, &Source, &Destination))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Compare AL with the destination */
@@ -1266,16 +1184,13 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeCmpXchgByte)
     if (State->Flags.Zf)
     {
         /* Load the source operand into the destination */
-        return Fast486WriteModrmByteOperands(State, &ModRegRm, FALSE, Source);
+        Fast486WriteModrmByteOperands(State, &ModRegRm, FALSE, Source);
     }
     else
     {
         /* Load the destination into AL */
         State->GeneralRegs[FAST486_REG_EAX].LowByte = Destination;
     }
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeCmpXchg)
@@ -1292,7 +1207,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeCmpXchg)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (OperandSize)
@@ -1304,7 +1219,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeCmpXchg)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, &Source, &Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Compare EAX with the destination */
@@ -1322,7 +1237,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeCmpXchg)
         if (State->Flags.Zf)
         {
             /* Load the source operand into the destination */
-            return Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Source);
+            Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Source);
         }
         else
         {
@@ -1339,7 +1254,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeCmpXchg)
         if (!Fast486ReadModrmWordOperands(State, &ModRegRm, &Source, &Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Compare AX with the destination */
@@ -1357,7 +1272,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeCmpXchg)
         if (State->Flags.Zf)
         {
             /* Load the source operand into the destination */
-            return Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Source);
+            Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Source);
         }
         else
         {
@@ -1365,9 +1280,6 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeCmpXchg)
             State->GeneralRegs[FAST486_REG_EAX].LowWord = Destination;
         }
     }
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLss)
@@ -1388,14 +1300,14 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLss)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (!ModRegRm.Memory)
     {
         /* Invalid */
         Fast486Exception(State, FAST486_EXCEPTION_UD);
-        return FALSE;
+        return;
     }
 
     if (!Fast486ReadMemory(State,
@@ -1407,7 +1319,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLss)
                            OperandSize ? 6 : 4))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (OperandSize)
@@ -1419,9 +1331,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLss)
         State->GeneralRegs[ModRegRm.Register].Long = Offset;
 
         /* Load the segment */
-        return Fast486LoadSegment(State,
-                                  FAST486_REG_SS,
-                                  Segment);
+        Fast486LoadSegment(State, FAST486_REG_SS, Segment);
     }
     else
     {
@@ -1432,9 +1342,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLss)
         State->GeneralRegs[ModRegRm.Register].LowWord = Offset;
 
         /* Load the segment */
-        return Fast486LoadSegment(State,
-                                  FAST486_REG_SS,
-                                  Segment);
+        Fast486LoadSegment(State, FAST486_REG_SS, Segment);
     }
 }
 
@@ -1457,7 +1365,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtr)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Get the bit number */
@@ -1484,7 +1392,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtr)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Set CF to the bit value */
@@ -1494,11 +1402,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtr)
         Value &= ~(1 << BitNumber);
 
         /* Write back the result */
-        if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value);
     }
     else
     {
@@ -1508,7 +1412,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtr)
         if (!Fast486ReadModrmWordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Set CF to the bit value */
@@ -1518,15 +1422,8 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtr)
         Value &= ~(1 << BitNumber);
 
         /* Write back the result */
-        if (!Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Value))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Value);
     }
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLfsLgs)
@@ -1547,14 +1444,14 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLfsLgs)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (!ModRegRm.Memory)
     {
         /* Invalid */
         Fast486Exception(State, FAST486_EXCEPTION_UD);
-        return FALSE;
+        return;
     }
 
     if (!Fast486ReadMemory(State,
@@ -1566,7 +1463,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLfsLgs)
                            OperandSize ? 6 : 4))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (OperandSize)
@@ -1578,10 +1475,10 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLfsLgs)
         State->GeneralRegs[ModRegRm.Register].Long = Offset;
 
         /* Load the segment */
-        return Fast486LoadSegment(State,
-                                  (Opcode == 0xB4)
-                                  ? FAST486_REG_FS : FAST486_REG_GS,
-                                  Segment);
+        Fast486LoadSegment(State,
+                           (Opcode == 0xB4)
+                           ? FAST486_REG_FS : FAST486_REG_GS,
+                           Segment);
     }
     else
     {
@@ -1592,10 +1489,10 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeLfsLgs)
         State->GeneralRegs[ModRegRm.Register].LowWord = Offset;
 
         /* Load the segment */
-        return Fast486LoadSegment(State,
-                                  (Opcode == 0xB4)
-                                  ? FAST486_REG_FS : FAST486_REG_GS,
-                                  Segment);
+        Fast486LoadSegment(State,
+                           (Opcode == 0xB4)
+                           ? FAST486_REG_FS : FAST486_REG_GS,
+                           Segment);
     }
 }
 
@@ -1614,21 +1511,21 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeMovzxByte)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Read the operands */
     if (!Fast486ReadModrmByteOperands(State, &ModRegRm, NULL, &Value))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Write back the zero-extended value */
-    return Fast486WriteModrmDwordOperands(State,
-                                          &ModRegRm,
-                                          TRUE,
-                                          (ULONG)Value);
+    Fast486WriteModrmDwordOperands(State,
+                                   &ModRegRm,
+                                   TRUE,
+                                   (ULONG)Value);
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeMovzxWord)
@@ -1646,21 +1543,21 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeMovzxWord)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Read the operands */
     if (!Fast486ReadModrmWordOperands(State, &ModRegRm, NULL, &Value))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Write back the zero-extended value */
-    return Fast486WriteModrmDwordOperands(State,
-                                          &ModRegRm,
-                                          TRUE,
-                                          (ULONG)Value);
+    Fast486WriteModrmDwordOperands(State,
+                                   &ModRegRm,
+                                   TRUE,
+                                   (ULONG)Value);
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtc)
@@ -1682,7 +1579,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtc)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Get the bit number */
@@ -1709,7 +1606,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtc)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Set CF to the bit value */
@@ -1719,11 +1616,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtc)
         Value ^= 1 << BitNumber;
 
         /* Write back the result */
-        if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Value);
     }
     else
     {
@@ -1733,7 +1626,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtc)
         if (!Fast486ReadModrmWordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Set CF to the bit value */
@@ -1743,15 +1636,8 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBtc)
         Value ^= 1 << BitNumber;
 
         /* Write back the result */
-        if (!Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Value))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Value);
     }
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsf)
@@ -1778,7 +1664,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsf)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Read the value */
@@ -1787,7 +1673,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsf)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     }
     else
@@ -1798,17 +1684,17 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsf)
                                           (PUSHORT)&Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     }
 
     /* Set ZF */
     State->Flags.Zf = (Value == 0);
-    if (State->Flags.Zf) return TRUE;
+    if (State->Flags.Zf) return;
 
     for (i = 0; i < DataSize; i++)
     {
-        if(Value & (1 << i))
+        if (Value & (1 << i))
         {
             /* Save the bit number */
             BitNumber = i;
@@ -1819,24 +1705,8 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsf)
     }
 
     /* Write back the result */
-    if (OperandSize)
-    {
-        if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, BitNumber))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
-    }
-    else
-    {
-        if (!Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, LOWORD(BitNumber)))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
-    }
-
-    return TRUE;
+    if (OperandSize) Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, BitNumber);
+    else Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, LOWORD(BitNumber));
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsr)
@@ -1863,7 +1733,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsr)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Read the value */
@@ -1872,7 +1742,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsr)
         if (!Fast486ReadModrmDwordOperands(State, &ModRegRm, NULL, &Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     }
     else
@@ -1883,17 +1753,17 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsr)
                                           (PUSHORT)&Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     }
 
     /* Set ZF according to the value */
     State->Flags.Zf = (Value == 0);
-    if (State->Flags.Zf) return TRUE;
+    if (State->Flags.Zf) return;
 
     for (i = DataSize - 1; i >= 0; i--)
     {
-        if(Value & (1 << i))
+        if (Value & (1 << i))
         {
             /* Save the bit number */
             BitNumber = i;
@@ -1904,24 +1774,8 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBsr)
     }
 
     /* Write back the result */
-    if (OperandSize)
-    {
-        if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, BitNumber))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
-    }
-    else
-    {
-        if (!Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, LOWORD(BitNumber)))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
-    }
-
-    return TRUE;
+    if (OperandSize) Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, BitNumber);
+    else Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, LOWORD(BitNumber));
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeMovsxByte)
@@ -1939,21 +1793,21 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeMovsxByte)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Read the operands */
     if (!Fast486ReadModrmByteOperands(State, &ModRegRm, NULL, (PUCHAR)&Value))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Write back the sign-extended value */
-    return Fast486WriteModrmDwordOperands(State,
-                                          &ModRegRm,
-                                          TRUE,
-                                          (ULONG)((LONG)Value));
+    Fast486WriteModrmDwordOperands(State,
+                                   &ModRegRm,
+                                   TRUE,
+                                   (ULONG)((LONG)Value));
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeMovsxWord)
@@ -1971,21 +1825,21 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeMovsxWord)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Read the operands */
     if (!Fast486ReadModrmWordOperands(State, &ModRegRm, NULL, (PUSHORT)&Value))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Write back the sign-extended value */
-    return Fast486WriteModrmDwordOperands(State,
-                                          &ModRegRm,
-                                          TRUE,
-                                          (ULONG)((LONG)Value));
+    Fast486WriteModrmDwordOperands(State,
+                                   &ModRegRm,
+                                   TRUE,
+                                   (ULONG)((LONG)Value));
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeConditionalJmp)
@@ -2006,7 +1860,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeConditionalJmp)
         if (!Fast486FetchDword(State, (PULONG)&Offset))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
     }
     else
@@ -2016,7 +1870,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeConditionalJmp)
         if (!Fast486FetchWord(State, (PUSHORT)&Value))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Sign-extend */
@@ -2093,9 +1947,6 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeConditionalJmp)
         /* Move the instruction pointer */
         State->InstPtr.Long += Offset;
     }
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeConditionalSet)
@@ -2110,7 +1961,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeConditionalSet)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Make sure this is the right instruction */
@@ -2182,7 +2033,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeConditionalSet)
     }
 
     /* Write back the result */
-    return Fast486WriteModrmByteOperands(State, &ModRegRm, FALSE, Value);
+    Fast486WriteModrmByteOperands(State, &ModRegRm, FALSE, Value);
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXaddByte)
@@ -2200,7 +2051,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXaddByte)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     if (!Fast486ReadModrmByteOperands(State,
@@ -2209,7 +2060,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXaddByte)
                                       &Destination))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Calculate the result */
@@ -2228,17 +2079,11 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXaddByte)
     if (!Fast486WriteModrmByteOperands(State, &ModRegRm, FALSE, Result))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Write the old value of the destination to the source */
-    if (!Fast486WriteModrmByteOperands(State, &ModRegRm, TRUE, Destination))
-    {
-        /* Exception occurred */
-        return FALSE;
-    }
-
-    return TRUE;
+    Fast486WriteModrmByteOperands(State, &ModRegRm, TRUE, Destination);
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXadd)
@@ -2258,7 +2103,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXadd)
     if (!Fast486ParseModRegRm(State, AddressSize, &ModRegRm))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
     /* Check the operand size */
@@ -2267,12 +2112,12 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXadd)
         ULONG Source, Destination, Result;
 
         if (!Fast486ReadModrmDwordOperands(State,
-                                          &ModRegRm,
-                                          &Source,
-                                          &Destination))
+                                           &ModRegRm,
+                                           &Source,
+                                           &Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Calculate the result */
@@ -2291,15 +2136,11 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXadd)
         if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, TRUE, Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Write the sum to the destination */
-        if (!Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Result))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        Fast486WriteModrmDwordOperands(State, &ModRegRm, FALSE, Result);
     }
     else
     {
@@ -2311,7 +2152,7 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXadd)
                                           &Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Calculate the result */
@@ -2330,18 +2171,12 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeXadd)
         if (!Fast486WriteModrmWordOperands(State, &ModRegRm, TRUE, Destination))
         {
             /* Exception occurred */
-            return FALSE;
+            return;
         }
 
         /* Write the sum to the destination */
-        if (!Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Result))
-        {
-            /* Exception occurred */
-            return FALSE;
-        }
+        Fast486WriteModrmWordOperands(State, &ModRegRm, FALSE, Result);
     }
-
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBswap)
@@ -2356,9 +2191,6 @@ FAST486_OPCODE_HANDLER(Fast486ExtOpcodeBswap)
     /* Swap the byte order */
     SWAP(Pointer[0], Pointer[3]);
     SWAP(Pointer[1], Pointer[2]);
-
-    /* Return success */
-    return TRUE;
 }
 
 FAST486_OPCODE_HANDLER(Fast486OpcodeExtended)
@@ -2369,19 +2201,11 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeExtended)
     if (!Fast486FetchByte(State, &SecondOpcode))
     {
         /* Exception occurred */
-        return FALSE;
+        return;
     }
 
-    if (Fast486ExtendedHandlers[SecondOpcode] != NULL)
-    {
-        /* Call the extended opcode handler */
-        return Fast486ExtendedHandlers[SecondOpcode](State, SecondOpcode);
-    }
-    else
-    {
-        /* This is not a valid opcode */
-        Fast486Exception(State, FAST486_EXCEPTION_UD);
-        return FALSE;
-    }
+    /* Call the extended opcode handler */
+    Fast486ExtendedHandlers[SecondOpcode](State, SecondOpcode);
 }
 
+/* EOF */