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[FAST486]
The current "fast" method used in MOVS gives incorrect results. It has been temporarily replaced with a slow method that works correctly. The string functions do nothing when CX is 0 on entry, fix CMPS and SCAS. svn path=/branches/ntvdm/; revision=61203
This commit is contained in:
Aleksandar Andrejevic
parent
84662d3de9
commit
e7a6deb93f
1 changed files with 81 additions and 145 deletions
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@ -5363,176 +5363,90 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeMovs)
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Segment = State->SegmentOverride;
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Segment = State->SegmentOverride;
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}
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}
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if (State->PrefixFlags & FAST486_PREFIX_REP)
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{
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if ((AddressSize && (State->GeneralRegs[FAST486_REG_ECX].Long == 0))
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|| (!AddressSize && (State->GeneralRegs[FAST486_REG_ECX].LowWord == 0)))
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{
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/* Do nothing */
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return TRUE;
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}
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}
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/* Calculate the size */
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/* Calculate the size */
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if (Opcode == 0xA4) DataSize = sizeof(UCHAR);
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if (Opcode == 0xA4) DataSize = sizeof(UCHAR);
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else DataSize = OperandSize ? sizeof(ULONG) : sizeof(USHORT);
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else DataSize = OperandSize ? sizeof(ULONG) : sizeof(USHORT);
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if (State->PrefixFlags & FAST486_PREFIX_REP)
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/* Read from the source operand */
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if (!Fast486ReadMemory(State,
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Segment,
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AddressSize ? State->GeneralRegs[FAST486_REG_ESI].Long
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: State->GeneralRegs[FAST486_REG_ESI].LowWord,
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FALSE,
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&Data,
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DataSize))
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{
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{
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UCHAR Block[STRING_BLOCK_SIZE];
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/* Exception occurred */
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ULONG Count = AddressSize ? State->GeneralRegs[FAST486_REG_ECX].Long
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return FALSE;
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: State->GeneralRegs[FAST486_REG_ECX].LowWord;
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}
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/* Clear the memory block */
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/* Write to the destination operand */
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RtlZeroMemory(Block, sizeof(Block));
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if (!Fast486WriteMemory(State,
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FAST486_REG_ES,
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AddressSize ? State->GeneralRegs[FAST486_REG_EDI].Long
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: State->GeneralRegs[FAST486_REG_EDI].LowWord,
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&Data,
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DataSize))
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{
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/* Exception occurred */
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return FALSE;
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}
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/* Transfer until finished */
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/* Increment/decrement ESI and EDI */
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while (Count)
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if (AddressSize)
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{
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if (!State->Flags.Df)
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{
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{
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ULONG Processed = min(Count, STRING_BLOCK_SIZE / DataSize);
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State->GeneralRegs[FAST486_REG_ESI].Long += DataSize;
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State->GeneralRegs[FAST486_REG_EDI].Long += DataSize;
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/* Simulate the 16-bit wrap-around of SI and DI in 16-bit address mode */
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}
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if (!AddressSize)
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else
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{
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{
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ULONG MaxBytesSrc = State->Flags.Df
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State->GeneralRegs[FAST486_REG_ESI].Long -= DataSize;
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? (ULONG)State->GeneralRegs[FAST486_REG_ESI].LowWord
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State->GeneralRegs[FAST486_REG_EDI].Long -= DataSize;
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: (0x10000 - (ULONG)State->GeneralRegs[FAST486_REG_ESI].LowWord);
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ULONG MaxBytesDest = State->Flags.Df
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? (ULONG)State->GeneralRegs[FAST486_REG_EDI].LowWord
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: (0x10000 - (ULONG)State->GeneralRegs[FAST486_REG_EDI].LowWord);
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Processed = min(Processed, min(MaxBytesSrc, MaxBytesDest) / DataSize);
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if (Processed == 0) Processed = 1;
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}
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if (State->Flags.Df)
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{
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/* Move ESI and EDI to the start of the block */
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if (AddressSize)
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{
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State->GeneralRegs[FAST486_REG_ESI].Long -= (Processed - 1) * DataSize;
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State->GeneralRegs[FAST486_REG_EDI].Long -= (Processed - 1) * DataSize;
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}
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else
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{
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State->GeneralRegs[FAST486_REG_ESI].LowWord -= (Processed - 1) * DataSize;
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State->GeneralRegs[FAST486_REG_EDI].LowWord -= (Processed - 1) * DataSize;
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}
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}
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/* Read from memory */
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if (!Fast486ReadMemory(State,
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Segment,
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AddressSize ? State->GeneralRegs[FAST486_REG_ESI].Long
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: State->GeneralRegs[FAST486_REG_ESI].LowWord,
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FALSE,
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Block,
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Processed * DataSize))
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{
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/* Set ECX */
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if (AddressSize) State->GeneralRegs[FAST486_REG_ECX].Long = Count;
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else State->GeneralRegs[FAST486_REG_ECX].LowWord = LOWORD(Count);
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/* Exception occurred */
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return FALSE;
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}
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/* Write to memory */
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if (!Fast486WriteMemory(State,
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FAST486_REG_ES,
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AddressSize ? State->GeneralRegs[FAST486_REG_EDI].Long
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: State->GeneralRegs[FAST486_REG_EDI].LowWord,
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Block,
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Processed * DataSize))
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{
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/* Set ECX */
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if (AddressSize) State->GeneralRegs[FAST486_REG_ECX].Long = Count;
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else State->GeneralRegs[FAST486_REG_ECX].LowWord = LOWORD(Count);
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/* Exception occurred */
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return FALSE;
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}
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if (!State->Flags.Df)
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{
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/* Increase ESI and EDI by the number of bytes transfered */
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if (AddressSize)
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{
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State->GeneralRegs[FAST486_REG_ESI].Long += Processed * DataSize;
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State->GeneralRegs[FAST486_REG_EDI].Long += Processed * DataSize;
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}
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else
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{
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State->GeneralRegs[FAST486_REG_ESI].LowWord += Processed * DataSize;
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State->GeneralRegs[FAST486_REG_EDI].LowWord += Processed * DataSize;
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}
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}
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else
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{
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/* Reduce ESI and EDI */
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if (AddressSize)
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{
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State->GeneralRegs[FAST486_REG_ESI].Long -= DataSize;
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State->GeneralRegs[FAST486_REG_EDI].Long -= DataSize;
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}
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else
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{
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State->GeneralRegs[FAST486_REG_ESI].LowWord -= DataSize;
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State->GeneralRegs[FAST486_REG_EDI].LowWord -= DataSize;
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}
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}
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/* Reduce the total count by the number processed in this run */
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Count -= Processed;
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}
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}
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/* Clear ECX */
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if (AddressSize) State->GeneralRegs[FAST486_REG_ECX].Long = 0;
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else State->GeneralRegs[FAST486_REG_ECX].LowWord = 0;
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}
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}
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else
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else
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{
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{
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/* Read from the source operand */
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if (!State->Flags.Df)
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if (!Fast486ReadMemory(State,
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FAST486_REG_DS,
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AddressSize ? State->GeneralRegs[FAST486_REG_ESI].Long
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: State->GeneralRegs[FAST486_REG_ESI].LowWord,
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FALSE,
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&Data,
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DataSize))
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{
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{
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/* Exception occurred */
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State->GeneralRegs[FAST486_REG_ESI].LowWord += DataSize;
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return FALSE;
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State->GeneralRegs[FAST486_REG_EDI].LowWord += DataSize;
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}
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}
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else
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/* Write to the destination operand */
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if (!Fast486WriteMemory(State,
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FAST486_REG_ES,
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AddressSize ? State->GeneralRegs[FAST486_REG_EDI].Long
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: State->GeneralRegs[FAST486_REG_EDI].LowWord,
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&Data,
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DataSize))
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{
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{
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/* Exception occurred */
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State->GeneralRegs[FAST486_REG_ESI].LowWord -= DataSize;
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return FALSE;
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State->GeneralRegs[FAST486_REG_EDI].LowWord -= DataSize;
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}
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}
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}
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/* Increment/decrement ESI and EDI */
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// FIXME: This method is slow!
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if (State->PrefixFlags & FAST486_PREFIX_REP)
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{
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if (AddressSize)
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if (AddressSize)
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{
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{
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if (!State->Flags.Df)
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if (--State->GeneralRegs[FAST486_REG_ECX].Long)
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{
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{
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State->GeneralRegs[FAST486_REG_ESI].Long += DataSize;
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/* Repeat the instruction */
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State->GeneralRegs[FAST486_REG_EDI].Long += DataSize;
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State->InstPtr = State->SavedInstPtr;
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}
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else
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{
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State->GeneralRegs[FAST486_REG_ESI].Long -= DataSize;
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State->GeneralRegs[FAST486_REG_EDI].Long -= DataSize;
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}
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}
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}
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}
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else
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else
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{
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{
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if (!State->Flags.Df)
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if (--State->GeneralRegs[FAST486_REG_ECX].LowWord)
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{
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{
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State->GeneralRegs[FAST486_REG_ESI].LowWord += DataSize;
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/* Repeat the instruction */
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State->GeneralRegs[FAST486_REG_EDI].LowWord += DataSize;
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State->InstPtr = State->SavedInstPtr;
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}
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else
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{
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State->GeneralRegs[FAST486_REG_ESI].LowWord -= DataSize;
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State->GeneralRegs[FAST486_REG_EDI].LowWord -= DataSize;
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}
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}
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}
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}
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}
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}
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@ -5562,6 +5476,17 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeCmps)
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Segment = State->SegmentOverride;
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Segment = State->SegmentOverride;
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}
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}
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if ((State->PrefixFlags & FAST486_PREFIX_REP)
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|| (State->PrefixFlags & FAST486_PREFIX_REPNZ))
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{
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if ((AddressSize && (State->GeneralRegs[FAST486_REG_ECX].Long == 0))
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|| (!AddressSize && (State->GeneralRegs[FAST486_REG_ECX].LowWord == 0)))
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{
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/* Do nothing */
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return TRUE;
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}
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}
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/* Calculate the size */
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/* Calculate the size */
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if (Opcode == 0xA6) DataSize = sizeof(UCHAR);
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if (Opcode == 0xA6) DataSize = sizeof(UCHAR);
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else DataSize = OperandSize ? sizeof(ULONG) : sizeof(USHORT);
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else DataSize = OperandSize ? sizeof(ULONG) : sizeof(USHORT);
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@ -5909,6 +5834,17 @@ FAST486_OPCODE_HANDLER(Fast486OpcodeScas)
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TOGGLE_OPSIZE(OperandSize);
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TOGGLE_OPSIZE(OperandSize);
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TOGGLE_ADSIZE(AddressSize);
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TOGGLE_ADSIZE(AddressSize);
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if ((State->PrefixFlags & FAST486_PREFIX_REP)
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|| (State->PrefixFlags & FAST486_PREFIX_REPNZ))
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{
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if ((AddressSize && (State->GeneralRegs[FAST486_REG_ECX].Long == 0))
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|| (!AddressSize && (State->GeneralRegs[FAST486_REG_ECX].LowWord == 0)))
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{
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/* Do nothing */
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return TRUE;
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}
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}
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/* Calculate the size */
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/* Calculate the size */
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if (Opcode == 0xAE) DataSize = sizeof(UCHAR);
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if (Opcode == 0xAE) DataSize = sizeof(UCHAR);
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else DataSize = OperandSize ? sizeof(ULONG) : sizeof(USHORT);
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else DataSize = OperandSize ? sizeof(ULONG) : sizeof(USHORT);
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