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1//
2// rotr.cpp
3//
4// Copyright (c) Microsoft Corporation. All rights reserved.
5//
6// Defines _lrotl(), _rotl(), and _rotl64(), which perform a rotate-right on an
7// integer.
8//
9#include <stdlib.h>
10#include <limits.h>
11
12
13
14#pragma function(_lrotr, _rotr, _rotr64)
15
16#if UINT_MAX != 0xffffffff
17 #error This source file assumes 32-bit integers
18#endif
19
20#if UINT_MAX != ULONG_MAX
21 #error This source file assumes sizeof(int) == sizeof(long)
22#endif
23
24
25
26extern "C" unsigned long __cdecl _lrotr(unsigned long value, int shift)
27{
28 shift &= 0x1f;
29 value = (value << (0x20 - shift)) | (value >> shift);
30 return value;
31}
32
33extern "C" unsigned __cdecl _rotr(unsigned value, int shift)
34{
35 shift &= 0x1f;
36 value = (value << (0x20 - shift)) | (value >> shift);
37 return value;
38}
39
40extern "C" unsigned __int64 __cdecl _rotr64(unsigned __int64 value, int shift)
41{
42 shift &= 0x3f;
43 value = (value << (0x40 - shift)) | (value >> shift);
44 return value;
45}