audk/MdePkg/Library/BaseLib/Ia32/ARShiftU64.c

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/** @file
64-bit arithmetic right shift function for IA-32.
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.
**/
/**
Shifts a 64-bit integer right between 0 and 63 bits. The high bits
are filled with original integer's bit 63. 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 bit 63 of Operand. 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 arithmetically shifted right by Count
**/
UINT64
EFIAPI
InternalMathARShiftU64 (
IN UINT64 Operand,
IN UINTN Count
)
{
_asm {
mov cl, byte ptr [Count]
mov eax, dword ptr [Operand + 4]
cdq
test cl, 32
cmovz edx, eax
cmovz eax, dword ptr [Operand + 0]
shrd eax, edx, cl
sar edx, cl
}
}