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/** @file
CompareMem() implementation.
The following BaseMemoryLib instances contain the same copy of this file:
BaseMemoryLib
BaseMemoryLibMmx
BaseMemoryLibSse2
BaseMemoryLibRepStr
BaseMemoryLibOptDxe
BaseMemoryLibOptPei
PeiMemoryLib
UefiMemoryLib
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "MemLibInternals.h"
/**
Compares the contents of two buffers.
This function compares Length bytes of SourceBuffer to Length bytes of DestinationBuffer.
If all Length bytes of the two buffers are identical, then 0 is returned. Otherwise, the
value returned is the first mismatched byte in SourceBuffer subtracted from the first
mismatched byte in DestinationBuffer.
If Length > 0 and DestinationBuffer is NULL, then ASSERT().
If Length > 0 and SourceBuffer is NULL, then ASSERT().
If Length is greater than (MAX_ADDRESS - DestinationBuffer + 1), then ASSERT().
If Length is greater than (MAX_ADDRESS - SourceBuffer + 1), then ASSERT().
@param DestinationBuffer The pointer to the destination buffer to compare.
@param SourceBuffer The pointer to the source buffer to compare.
@param Length The number of bytes to compare.
@return 0 All Length bytes of the two buffers are identical.
@retval Non-zero The first mismatched byte in SourceBuffer subtracted from the first
mismatched byte in DestinationBuffer.
**/
INTN
EFIAPI
CompareMem (
IN CONST VOID *DestinationBuffer,
IN CONST VOID *SourceBuffer,
IN UINTN Length
)
{
if ((Length == 0) || (DestinationBuffer == SourceBuffer)) {
return 0;
}
ASSERT (DestinationBuffer != NULL);
ASSERT (SourceBuffer != NULL);
ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)DestinationBuffer));
ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)SourceBuffer));
return InternalMemCompareMem (DestinationBuffer, SourceBuffer, Length);
}