1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef _LIBCPP___MATH_GAMMA_H
10#define _LIBCPP___MATH_GAMMA_H
11
12#include <__config>
13#include <__type_traits/enable_if.h>
14#include <__type_traits/is_integral.h>
15
16#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17# pragma GCC system_header
18#endif
19
20_LIBCPP_BEGIN_NAMESPACE_STD
21
22namespace __math {
23
24// lgamma
25
26inline _LIBCPP_HIDE_FROM_ABI float lgamma(float __x) _NOEXCEPT { return __builtin_lgammaf(__x); }
27
28template <class = int>
29_LIBCPP_HIDE_FROM_ABI double lgamma(double __x) _NOEXCEPT {
30 return __builtin_lgamma(__x);
31}
32
33inline _LIBCPP_HIDE_FROM_ABI long double lgamma(long double __x) _NOEXCEPT { return __builtin_lgammal(__x); }
34
35template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
36inline _LIBCPP_HIDE_FROM_ABI double lgamma(_A1 __x) _NOEXCEPT {
37 return __builtin_lgamma((double)__x);
38}
39
40// nan
41
42// tgamma
43
44inline _LIBCPP_HIDE_FROM_ABI float tgamma(float __x) _NOEXCEPT { return __builtin_tgammaf(__x); }
45
46template <class = int>
47_LIBCPP_HIDE_FROM_ABI double tgamma(double __x) _NOEXCEPT {
48 return __builtin_tgamma(__x);
49}
50
51inline _LIBCPP_HIDE_FROM_ABI long double tgamma(long double __x) _NOEXCEPT { return __builtin_tgammal(__x); }
52
53template <class _A1, __enable_if_t<is_integral<_A1>::value, int> = 0>
54inline _LIBCPP_HIDE_FROM_ABI double tgamma(_A1 __x) _NOEXCEPT {
55 return __builtin_tgamma((double)__x);
56}
57
58// __lgamma_r
59//
60// POSIX systems provide a function named lgamma_r which is a reentrant version of lgamma. Use that
61// whenever possible. However, we avoid re-declaring the actual function since different platforms
62// declare it differently in the first place: instead use `asm` to get the compiler to call the right
63// function.
64
65#if defined(_LIBCPP_MSVCRT_LIKE) // reentrant version is not available on Windows
66
67inline _LIBCPP_HIDE_FROM_ABI double __lgamma_r(double __d) _NOEXCEPT { return __builtin_lgamma(__d); }
68
69#else
70
71# if defined(_LIBCPP_OBJECT_FORMAT_MACHO)
72double __lgamma_r_shim(double, int*) _NOEXCEPT __asm__("_lgamma_r");
73# else
74double __lgamma_r_shim(double, int*) _NOEXCEPT __asm__("lgamma_r");
75# endif
76
77inline _LIBCPP_HIDE_FROM_ABI double __lgamma_r(double __d) _NOEXCEPT {
78 int __sign;
79 return __math::__lgamma_r_shim(__d, &__sign);
80}
81
82#endif
83
84} // namespace __math
85
86_LIBCPP_END_NAMESPACE_STD
87
88#endif // _LIBCPP___MATH_GAMMA_H
89