1 /** @file 2 64-bit right rotation for Ia32 3 4 Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR> 5 This program and the accompanying materials 6 are licensed and made available under the terms and conditions of the BSD License 7 which accompanies this distribution. The full text of the license may be found at 8 http://opensource.org/licenses/bsd-license.php. 9 10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 12 13 **/ 14 15 16 17 18 /** 19 Rotates a 64-bit integer right between 0 and 63 bits, filling 20 the high bits with the high low bits that were rotated. 21 22 This function rotates the 64-bit value Operand to the right by Count bits. 23 The high Count bits are fill with the low Count bits of Operand. The rotated 24 value is returned. 25 26 @param Operand The 64-bit operand to rotate right. 27 @param Count The number of bits to rotate right. 28 29 @return Operand >>> Count 30 31 **/ 32 UINT64 33 EFIAPI 34 InternalMathRRotU64 ( 35 IN UINT64 Operand, 36 IN UINTN Count 37 ) 38 { 39 _asm { 40 mov cl, byte ptr [Count] 41 mov eax, dword ptr [Operand + 0] 42 mov edx, dword ptr [Operand + 4] 43 shrd ebx, eax, cl 44 shrd eax, edx, cl 45 rol ebx, cl 46 shrd edx, ebx, cl 47 test cl, 32 // Count >= 32? 48 jz L0 49 mov ecx, eax 50 mov eax, edx 51 mov edx, ecx 52 L0: 53 } 54 } 55 56
