1 /** @file
2 64-bit left 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 left between 0 and 63 bits, filling
20 the low bits with the high bits that were rotated.
21
22 This function rotates the 64-bit value Operand to the left by Count bits. The
23 low Count bits are fill with the high Count bits of Operand. The rotated
24 value is returned.
25
26 @param Operand The 64-bit operand to rotate left.
27 @param Count The number of bits to rotate left.
28
29 @return Operand <<< Count
30
31 **/
32 UINT64
33 EFIAPI
InternalMathLRotU64(IN UINT64 Operand,IN UINTN Count)34 InternalMathLRotU64 (
35 IN UINT64 Operand,
36 IN UINTN Count
37 )
38 {
39 _asm {
40 mov cl, byte ptr [Count]
41 mov edx, dword ptr [Operand + 4]
42 mov eax, dword ptr [Operand + 0]
43 shld ebx, edx, cl
44 shld edx, eax, cl
45 ror ebx, cl
46 shld eax, 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