mirror of
https://github.com/ziglang/zig.git
synced 2024-12-04 02:48:50 +00:00
101 lines
3.2 KiB
C++
Vendored
101 lines
3.2 KiB
C++
Vendored
// -*- C++ -*-
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef _LIBCPP___NUMERIC_GCD_LCM_H
|
|
#define _LIBCPP___NUMERIC_GCD_LCM_H
|
|
|
|
#include <__assert>
|
|
#include <__config>
|
|
#include <__type_traits/common_type.h>
|
|
#include <__type_traits/is_integral.h>
|
|
#include <__type_traits/is_same.h>
|
|
#include <__type_traits/is_signed.h>
|
|
#include <__type_traits/make_unsigned.h>
|
|
#include <limits>
|
|
|
|
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
|
|
# pragma GCC system_header
|
|
#endif
|
|
|
|
_LIBCPP_PUSH_MACROS
|
|
#include <__undef_macros>
|
|
|
|
_LIBCPP_BEGIN_NAMESPACE_STD
|
|
|
|
#if _LIBCPP_STD_VER > 14
|
|
|
|
template <typename _Result, typename _Source, bool _IsSigned = is_signed<_Source>::value> struct __ct_abs;
|
|
|
|
template <typename _Result, typename _Source>
|
|
struct __ct_abs<_Result, _Source, true> {
|
|
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
|
|
_Result operator()(_Source __t) const noexcept
|
|
{
|
|
if (__t >= 0) return __t;
|
|
if (__t == numeric_limits<_Source>::min()) return -static_cast<_Result>(__t);
|
|
return -__t;
|
|
}
|
|
};
|
|
|
|
template <typename _Result, typename _Source>
|
|
struct __ct_abs<_Result, _Source, false> {
|
|
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
|
|
_Result operator()(_Source __t) const noexcept { return __t; }
|
|
};
|
|
|
|
|
|
template<class _Tp>
|
|
_LIBCPP_CONSTEXPR _LIBCPP_HIDDEN
|
|
_Tp __gcd(_Tp __m, _Tp __n)
|
|
{
|
|
static_assert((!is_signed<_Tp>::value), "");
|
|
return __n == 0 ? __m : _VSTD::__gcd<_Tp>(__n, __m % __n);
|
|
}
|
|
|
|
template<class _Tp, class _Up>
|
|
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
|
|
common_type_t<_Tp,_Up>
|
|
gcd(_Tp __m, _Up __n)
|
|
{
|
|
static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to gcd must be integer types");
|
|
static_assert((!is_same<__remove_cv_t<_Tp>, bool>::value), "First argument to gcd cannot be bool" );
|
|
static_assert((!is_same<__remove_cv_t<_Up>, bool>::value), "Second argument to gcd cannot be bool" );
|
|
using _Rp = common_type_t<_Tp,_Up>;
|
|
using _Wp = make_unsigned_t<_Rp>;
|
|
return static_cast<_Rp>(_VSTD::__gcd(
|
|
static_cast<_Wp>(__ct_abs<_Rp, _Tp>()(__m)),
|
|
static_cast<_Wp>(__ct_abs<_Rp, _Up>()(__n))));
|
|
}
|
|
|
|
template<class _Tp, class _Up>
|
|
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
|
|
common_type_t<_Tp,_Up>
|
|
lcm(_Tp __m, _Up __n)
|
|
{
|
|
static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to lcm must be integer types");
|
|
static_assert((!is_same<__remove_cv_t<_Tp>, bool>::value), "First argument to lcm cannot be bool" );
|
|
static_assert((!is_same<__remove_cv_t<_Up>, bool>::value), "Second argument to lcm cannot be bool" );
|
|
if (__m == 0 || __n == 0)
|
|
return 0;
|
|
|
|
using _Rp = common_type_t<_Tp,_Up>;
|
|
_Rp __val1 = __ct_abs<_Rp, _Tp>()(__m) / _VSTD::gcd(__m, __n);
|
|
_Rp __val2 = __ct_abs<_Rp, _Up>()(__n);
|
|
_LIBCPP_ASSERT((numeric_limits<_Rp>::max() / __val1 > __val2), "Overflow in lcm");
|
|
return __val1 * __val2;
|
|
}
|
|
|
|
#endif // _LIBCPP_STD_VER
|
|
|
|
_LIBCPP_END_NAMESPACE_STD
|
|
|
|
_LIBCPP_POP_MACROS
|
|
|
|
#endif // _LIBCPP___NUMERIC_GCD_LCM_H
|