mirror of https://github.com/acidanthera/audk.git
54 lines
1.5 KiB
C
54 lines
1.5 KiB
C
/** @file
|
|
64-bit right rotation for Ia32
|
|
|
|
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.
|
|
|
|
**/
|
|
|
|
|
|
|
|
|
|
/**
|
|
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
|
|
}
|
|
}
|
|
|