libstdc++-v3/include/bits/std_abs.h

   1 // -*- C++ -*- C library enhancements header.
   2
   3 // Copyright (C) 2016-2024 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /** @file include/bits/std_abs.h
  26  *  This is an internal header file, included by other library headers.
  27  *  Do not attempt to use it directly. @headername{cmath, cstdlib}
  28  */
  29
  30 #ifndef _GLIBCXX_BITS_STD_ABS_H
  31 #define _GLIBCXX_BITS_STD_ABS_H
  32
  33 #pragma GCC system_header
  34
  35 #include <bits/c++config.h>
  36
  37 #define _GLIBCXX_INCLUDE_NEXT_C_HEADERS
  38 #include_next <stdlib.h>
  39 #ifdef __CORRECT_ISO_CPP_MATH_H_PROTO
  40 # include_next <math.h>
  41 #endif
  42 #undef _GLIBCXX_INCLUDE_NEXT_C_HEADERS
  43
  44 #undef abs
  45
  46 extern "C++"
  47 {
  48 namespace std _GLIBCXX_VISIBILITY(default)
  49 {
  50 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  51
  52   using ::abs;
  53
  54 #ifndef __CORRECT_ISO_CPP_STDLIB_H_PROTO
  55   inline long
  56   abs(long __i) { return __builtin_labs(__i); }
  57 #endif
  58
  59 #ifdef _GLIBCXX_USE_LONG_LONG
  60   inline long long
  61   abs(long long __x) { return __builtin_llabs (__x); }
  62 #endif
  63
  64 // _GLIBCXX_RESOLVE_LIB_DEFECTS
  65 // 2192. Validity and return type of std::abs(0u) is unclear
  66 // 2294. <cstdlib> should declare abs(double)
  67 // 2735. std::abs(short), std::abs(signed char) and others should return int
  68
  69 #ifndef __CORRECT_ISO_CPP_MATH_H_PROTO
  70   inline _GLIBCXX_CONSTEXPR double
  71   abs(double __x)
  72   { return __builtin_fabs(__x); }
  73
  74   inline _GLIBCXX_CONSTEXPR float
  75   abs(float __x)
  76   { return __builtin_fabsf(__x); }
  77
  78   inline _GLIBCXX_CONSTEXPR long double
  79   abs(long double __x)
  80   { return __builtin_fabsl(__x); }
  81 #endif
  82
  83 #if defined(__GLIBCXX_TYPE_INT_N_0)
  84   __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_0
  85   abs(__GLIBCXX_TYPE_INT_N_0 __x) { return __x >= 0 ? __x : -__x; }
  86 #endif
  87 #if defined(__GLIBCXX_TYPE_INT_N_1)
  88   __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_1
  89   abs(__GLIBCXX_TYPE_INT_N_1 __x) { return __x >= 0 ? __x : -__x; }
  90 #endif
  91 #if defined(__GLIBCXX_TYPE_INT_N_2)
  92   __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_2
  93   abs(__GLIBCXX_TYPE_INT_N_2 __x) { return __x >= 0 ? __x : -__x; }
  94 #endif
  95 #if defined(__GLIBCXX_TYPE_INT_N_3)
  96   __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_3
  97   abs(__GLIBCXX_TYPE_INT_N_3 __x) { return __x >= 0 ? __x : -__x; }
  98 #endif
  99
 100 #if defined(__STDCPP_FLOAT16_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
 101   constexpr _Float16
 102   abs(_Float16 __x)
 103   { return _Float16(__builtin_fabsf(__x)); }
 104 #endif
 105
 106 #if defined(__STDCPP_FLOAT32_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
 107   constexpr _Float32
 108   abs(_Float32 __x)
 109   { return __builtin_fabsf(__x); }
 110 #endif
 111
 112 #if defined(__STDCPP_FLOAT64_T__) && defined(_GLIBCXX_DOUBLE_IS_IEEE_BINARY64)
 113   constexpr _Float64
 114   abs(_Float64 __x)
 115   { return __builtin_fabs(__x); }
 116 #endif
 117
 118 #if defined(__STDCPP_FLOAT128_T__) && defined(_GLIBCXX_LDOUBLE_IS_IEEE_BINARY128)
 119   constexpr _Float128
 120   abs(_Float128 __x)
 121   { return __builtin_fabsl(__x); }
 122 #elif defined(__STDCPP_FLOAT128_T__) && defined(_GLIBCXX_HAVE_FLOAT128_MATH)
 123   constexpr _Float128
 124   abs(_Float128 __x)
 125   { return __builtin_fabsf128(__x); }
 126 #endif
 127
 128 #if defined(__STDCPP_BFLOAT16_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
 129   constexpr __gnu_cxx::__bfloat16_t
 130   abs(__gnu_cxx::__bfloat16_t __x)
 131   { return __gnu_cxx::__bfloat16_t(__builtin_fabsf(__x)); }
 132 #endif
 133
 134 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128)
 135   __extension__ inline _GLIBCXX_CONSTEXPR
 136   __float128
 137   abs(__float128 __x)
 138   {
 139 #if defined(_GLIBCXX_LDOUBLE_IS_IEEE_BINARY128)
 140     return __builtin_fabsl(__x);
 141 #elif defined(_GLIBCXX_HAVE_FLOAT128_MATH)
 142     return __builtin_fabsf128(__x);
 143 #else
 144     // Assume that __builtin_signbit works for __float128.
 145     return __builtin_signbit(__x) ? -__x : __x;
 146 #endif
 147   }
 148 #endif
 149
 150 _GLIBCXX_END_NAMESPACE_VERSION
 151 } // namespace
 152 } // extern "C++"
 153
 154 #endif // _GLIBCXX_BITS_STD_ABS_H