/** @file | |
Implementation of the InternalMemCopyMem routine. This function is broken | |
out into its own source file so that it can be excluded from a build for a | |
particular platform easily if an optimized version is desired. | |
Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR> | |
This program and the accompanying materials | |
are licensed and made available under the terms and conditions of the BSD License | |
which accompanies this distribution. The full text of the license may be found at | |
http://opensource.org/licenses/bsd-license.php. | |
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
**/ | |
#include "MemLibInternals.h" | |
/** | |
Copy Length bytes from Source to Destination. | |
@param DestinationBuffer The target of the copy request. | |
@param SourceBuffer The place to copy from. | |
@param Length The number of bytes to copy. | |
@return Destination | |
**/ | |
VOID * | |
EFIAPI | |
InternalMemCopyMem ( | |
OUT VOID *DestinationBuffer, | |
IN CONST VOID *SourceBuffer, | |
IN UINTN Length | |
) | |
{ | |
// | |
// Declare the local variables that actually move the data elements as | |
// volatile to prevent the optimizer from replacing this function with | |
// the intrinsic memcpy() | |
// | |
volatile UINT8 *Destination8; | |
CONST UINT8 *Source8; | |
if (SourceBuffer > DestinationBuffer) { | |
Destination8 = (UINT8*)DestinationBuffer; | |
Source8 = (CONST UINT8*)SourceBuffer; | |
while (Length-- != 0) { | |
*(Destination8++) = *(Source8++); | |
} | |
} else if (SourceBuffer < DestinationBuffer) { | |
Destination8 = (UINT8*)DestinationBuffer + Length; | |
Source8 = (CONST UINT8*)SourceBuffer + Length; | |
while (Length-- != 0) { | |
*(--Destination8) = *(--Source8); | |
} | |
} | |
return DestinationBuffer; | |
} |