xref: /openbsd-src/gnu/llvm/libcxx/include/__bit/rotate.h (revision 4bdff4bed0e3d54e55670334c7d0077db4170f86)
1*4bdff4beSrobert //===----------------------------------------------------------------------===//
2*4bdff4beSrobert //
3*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information.
5*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*4bdff4beSrobert //
7*4bdff4beSrobert //===----------------------------------------------------------------------===//
8*4bdff4beSrobert 
9*4bdff4beSrobert #ifndef _LIBCPP___BIT_ROTATE_H
10*4bdff4beSrobert #define _LIBCPP___BIT_ROTATE_H
11*4bdff4beSrobert 
12*4bdff4beSrobert #include <__concepts/arithmetic.h>
13*4bdff4beSrobert #include <__config>
14*4bdff4beSrobert #include <__type_traits/is_unsigned_integer.h>
15*4bdff4beSrobert #include <limits>
16*4bdff4beSrobert 
17*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18*4bdff4beSrobert #  pragma GCC system_header
19*4bdff4beSrobert #endif
20*4bdff4beSrobert 
21*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD
22*4bdff4beSrobert 
23*4bdff4beSrobert template<class _Tp>
24*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14
__rotr(_Tp __t,unsigned int __cnt)25*4bdff4beSrobert _Tp __rotr(_Tp __t, unsigned int __cnt) _NOEXCEPT
26*4bdff4beSrobert {
27*4bdff4beSrobert     static_assert(__libcpp_is_unsigned_integer<_Tp>::value, "__rotr requires an unsigned integer type");
28*4bdff4beSrobert     const unsigned int __dig = numeric_limits<_Tp>::digits;
29*4bdff4beSrobert     if ((__cnt % __dig) == 0)
30*4bdff4beSrobert         return __t;
31*4bdff4beSrobert     return (__t >> (__cnt % __dig)) | (__t << (__dig - (__cnt % __dig)));
32*4bdff4beSrobert }
33*4bdff4beSrobert 
34*4bdff4beSrobert #if _LIBCPP_STD_VER >= 20
35*4bdff4beSrobert 
36*4bdff4beSrobert template <__libcpp_unsigned_integer _Tp>
rotl(_Tp __t,unsigned int __cnt)37*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI constexpr _Tp rotl(_Tp __t, unsigned int __cnt) noexcept {
38*4bdff4beSrobert   const unsigned int __dig = numeric_limits<_Tp>::digits;
39*4bdff4beSrobert   if ((__cnt % __dig) == 0)
40*4bdff4beSrobert     return __t;
41*4bdff4beSrobert   return (__t << (__cnt % __dig)) | (__t >> (__dig - (__cnt % __dig)));
42*4bdff4beSrobert }
43*4bdff4beSrobert 
44*4bdff4beSrobert template <__libcpp_unsigned_integer _Tp>
rotr(_Tp __t,unsigned int __cnt)45*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI constexpr _Tp rotr(_Tp __t, unsigned int __cnt) noexcept {
46*4bdff4beSrobert   return std::__rotr(__t, __cnt);
47*4bdff4beSrobert }
48*4bdff4beSrobert 
49*4bdff4beSrobert #endif // _LIBCPP_STD_VER >= 20
50*4bdff4beSrobert 
51*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD
52*4bdff4beSrobert 
53*4bdff4beSrobert #endif // _LIBCPP___BIT_ROTATE_H
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