audk/MdePkg/Library/BaseLib/Ia32/DivU64x32.c

51 lines
1.5 KiB
C

/** @file
Calculate the quotient of a 64-bit integer by a 32-bit integer
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.
**/
/**
Divides a 64-bit unsigned integer by a 32-bit unsigned integer and
generates a 64-bit unsigned result.
This function divides the 64-bit unsigned value Dividend by the 32-bit
unsigned value Divisor and generates a 64-bit unsigned quotient. This
function returns the 64-bit unsigned quotient.
@param Dividend A 64-bit unsigned value.
@param Divisor A 32-bit unsigned value.
@return Dividend / Divisor
**/
UINT64
EFIAPI
InternalMathDivU64x32 (
IN UINT64 Dividend,
IN UINT32 Divisor
)
{
_asm {
mov eax, dword ptr [Dividend + 4]
mov ecx, Divisor
xor edx, edx
div ecx
push eax ; save quotient on stack
mov eax, dword ptr [Dividend]
div ecx
pop edx ; restore high-order dword of the quotient
}
}