audk/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/EfiCompareMem.c

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/*++
Copyright (c) 2004, Intel Corporation
All rights reserved. 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.
Module Name:
EfiCompareMem.c
Abstract:
Generic compare-memory routine.
--*/
#include "Tiano.h"
#include "EfiDriverLib.h"
INTN
EfiCompareMem (
IN VOID *MemOne,
IN VOID *MemTwo,
IN UINTN Length
)
/*++
Routine Description:
Compares two memory buffers of a given length.
Arguments:
MemOne - First memory buffer
MemTwo - Second memory buffer
Len - Length of Mem1 and Mem2 memory regions to compare
Returns:
= 0 if MemOne == MemTwo
--*/
{
INTN ReturnValue;
if (!(EFI_UINTN_ALIGNED (MemOne) || EFI_UINTN_ALIGNED (MemTwo) || EFI_UINTN_ALIGNED (Length))) {
//
// If Destination/Source/Length are aligned do UINTN conpare
//
for (; Length > 0; Length -= sizeof (INTN), MemOne = (VOID *)((UINTN)MemOne + sizeof (INTN)), MemTwo = (VOID *)((UINTN)MemTwo + sizeof (INTN))) {
if (*(INTN *)MemOne != *(INTN *)MemTwo) {
break;
}
}
}
//
// If Destination/Source/Length not aligned do byte compare
//
for (; Length > 0; Length--, MemOne = (VOID *)((UINTN)MemOne + 1), MemTwo = (VOID *)((UINTN)MemTwo + 1)) {
ReturnValue = (INTN)(*(INT8 *)MemOne - *(INT8 *)MemTwo);
if (ReturnValue != 0) {
return ReturnValue;
}
}
return 0;
}