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/** @file
64-bit right rotation for Ia32
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.
**/
/**
Rotates a 64-bit integer right between 0 and 63 bits, filling
the high bits with the high low bits that were rotated.
This function rotates the 64-bit value Operand to the right by Count bits.
The high Count bits are fill with the low Count bits of Operand. The rotated
value is returned.
@param Operand The 64-bit operand to rotate right.
@param Count The number of bits to rotate right.
@return Operand >>> Count
**/
UINT64
EFIAPI
InternalMathRRotU64 (
IN UINT64 Operand,
IN UINTN Count
)
{
_asm {
mov cl, byte ptr [Count]
mov eax, dword ptr [Operand + 0]
mov edx, dword ptr [Operand + 4]
shrd ebx, eax, cl
shrd eax, edx, cl
rol ebx, cl
shrd edx, ebx, cl
test cl, 32 // Count >= 32?
cmovnz ecx, eax
cmovnz eax, edx
cmovnz edx, ecx
}
}
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