audk/MdePkg/Library/BaseLib/Ia32/SwapBytes64.c

46 lines
1.1 KiB
C

/** @file
Implementation of 64-bit swap bytes
Copyright (c) 2006 - 2007, Intel Corporation<BR>
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.
**/
//
// Include common header file for this module.
//
/**
Switches the endianess of a 64-bit integer.
This function swaps the bytes in a 64-bit unsigned value to switch the value
from little endian to big endian or vice versa. The byte swapped value is
returned.
@param Operand A 64-bit unsigned value.
@return The byte swaped Operand.
**/
UINT64
EFIAPI
InternalMathSwapBytes64 (
IN UINT64 Operand
)
{
_asm {
mov eax, dword ptr [Operand + 4]
mov edx, dword ptr [Operand + 0]
bswap eax
bswap edx
}
}