/** @file | |
64-bit arithmetic right shift function for IA-32. | |
Copyright (c) 2006 - 2015, 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. 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 | |
jnz L0 | |
mov edx, eax | |
mov eax, dword ptr [Operand + 0] | |
L0: | |
shrd eax, edx, cl | |
sar edx, cl | |
} | |
} | |