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/** @file
64-bit logical right shift function for IA-32
Copyright (c) 2006 - 2008, 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.
**/
/**
Shifts a 64-bit integer right between 0 and 63 bits. This high bits
are filled with zeros. The shifted value is returned.
This function shifts the 64-bit value Operand to the right by Count bits. The
high Count bits are set to zero. The shifted value is returned.
@param Operand The 64-bit operand to shift right.
@param Count The number of bits to shift right.
@return Operand >> Count
**/
UINT64
EFIAPI
InternalMathRShiftU64 (
IN UINT64 Operand,
IN UINTN Count
)
{
_asm {
mov cl, byte ptr [Count]
xor edx, edx
mov eax, dword ptr [Operand + 4]
test cl, 32
cmovz edx, eax
cmovz eax, dword ptr [Operand + 0]
shrd eax, edx, cl
shr edx, cl
}
}
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