/** @file | |
64-bit right rotation for Ia32 | |
Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR> | |
SPDX-License-Identifier: BSD-2-Clause-Patent | |
**/ | |
/** | |
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? | |
jz L0 | |
mov ecx, eax | |
mov eax, edx | |
mov edx, ecx | |
L0: | |
} | |
} |