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The C and C++ Include Header Files
cat -n /usr/include/c++/15/bits/std_abs.h
1 // -*- C++ -*- C library enhancements header. 2 3 // Copyright (C) 2016-2025 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 #ifdef _GLIBCXX_SYSHDR 34 #pragma GCC system_header 35 #endif 36 37 #include <bits/c++config.h> 38 39 #pragma GCC diagnostic push 40 #pragma GCC diagnostic ignored "-Wpedantic" // include_next 41 #pragma GCC diagnostic ignored "-Wlong-long" 42 43 #define _GLIBCXX_INCLUDE_NEXT_C_HEADERS 44 #include_next <stdlib.h> 45 #ifdef __CORRECT_ISO_CPP_MATH_H_PROTO 46 # include_next <math.h> 47 #endif 48 #undef _GLIBCXX_INCLUDE_NEXT_C_HEADERS 49 50 #undef abs 51 52 extern "C++" 53 { 54 namespace std _GLIBCXX_VISIBILITY(default) 55 { 56 _GLIBCXX_BEGIN_NAMESPACE_VERSION 57 58 using ::abs; 59 60 #ifndef __CORRECT_ISO_CPP_STDLIB_H_PROTO 61 inline long 62 abs(long __i) { return __builtin_labs(__i); } 63 #endif 64 65 #ifdef _GLIBCXX_USE_LONG_LONG 66 inline long long 67 abs(long long __x) { return __builtin_llabs (__x); } 68 #endif 69 70 // _GLIBCXX_RESOLVE_LIB_DEFECTS 71 // 2192. Validity and return type of std::abs(0u) is unclear 72 // 2294. <cstdlib> should declare abs(double) 73 // 2735. std::abs(short), std::abs(signed char) and others should return int 74 75 #ifndef __CORRECT_ISO_CPP_MATH_H_PROTO 76 inline _GLIBCXX_CONSTEXPR double 77 abs(double __x) 78 { return __builtin_fabs(__x); } 79 80 inline _GLIBCXX_CONSTEXPR float 81 abs(float __x) 82 { return __builtin_fabsf(__x); } 83 84 inline _GLIBCXX_CONSTEXPR long double 85 abs(long double __x) 86 { return __builtin_fabsl(__x); } 87 #endif 88 89 #if defined(__GLIBCXX_TYPE_INT_N_0) 90 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_0 91 abs(__GLIBCXX_TYPE_INT_N_0 __x) { return __x >= 0 ? __x : -__x; } 92 #endif 93 #if defined(__GLIBCXX_TYPE_INT_N_1) 94 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_1 95 abs(__GLIBCXX_TYPE_INT_N_1 __x) { return __x >= 0 ? __x : -__x; } 96 #endif 97 #if defined(__GLIBCXX_TYPE_INT_N_2) 98 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_2 99 abs(__GLIBCXX_TYPE_INT_N_2 __x) { return __x >= 0 ? __x : -__x; } 100 #endif 101 #if defined(__GLIBCXX_TYPE_INT_N_3) 102 __extension__ inline _GLIBCXX_CONSTEXPR __GLIBCXX_TYPE_INT_N_3 103 abs(__GLIBCXX_TYPE_INT_N_3 __x) { return __x >= 0 ? __x : -__x; } 104 #endif 105 106 #if defined(__STDCPP_FLOAT16_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32) 107 constexpr _Float16 108 abs(_Float16 __x) 109 { return _Float16(__builtin_fabsf(__x)); } 110 #endif 111 112 #if defined(__STDCPP_FLOAT32_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32) 113 constexpr _Float32 114 abs(_Float32 __x) 115 { return __builtin_fabsf(__x); } 116 #endif 117 118 #if defined(__STDCPP_FLOAT64_T__) && defined(_GLIBCXX_DOUBLE_IS_IEEE_BINARY64) 119 constexpr _Float64 120 abs(_Float64 __x) 121 { return __builtin_fabs(__x); } 122 #endif 123 124 #if defined(__STDCPP_FLOAT128_T__) && defined(_GLIBCXX_LDOUBLE_IS_IEEE_BINARY128) 125 constexpr _Float128 126 abs(_Float128 __x) 127 { return __builtin_fabsl(__x); } 128 #elif defined(__STDCPP_FLOAT128_T__) && defined(_GLIBCXX_HAVE_FLOAT128_MATH) 129 constexpr _Float128 130 abs(_Float128 __x) 131 { return __builtin_fabsf128(__x); } 132 #endif 133 134 #if defined(__STDCPP_BFLOAT16_T__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32) 135 constexpr __gnu_cxx::__bfloat16_t 136 abs(__gnu_cxx::__bfloat16_t __x) 137 { return __gnu_cxx::__bfloat16_t(__builtin_fabsf(__x)); } 138 #endif 139 140 #if !defined(__STRICT_ANSI__) && defined(_GLIBCXX_USE_FLOAT128) && !defined(__CUDACC__) 141 __extension__ inline _GLIBCXX_CONSTEXPR 142 __float128 143 abs(__float128 __x) 144 { 145 #if defined(_GLIBCXX_LDOUBLE_IS_IEEE_BINARY128) 146 return __builtin_fabsl(__x); 147 #elif defined(_GLIBCXX_HAVE_FLOAT128_MATH) 148 return __builtin_fabsf128(__x); 149 #else 150 // Assume that __builtin_signbit works for __float128. 151 return __builtin_signbit(__x) ? -__x : __x; 152 #endif 153 } 154 #endif 155 156 _GLIBCXX_END_NAMESPACE_VERSION 157 } // namespace 158 } // extern "C++" 159 160 #pragma GCC diagnostic pop 161 162 #endif // _GLIBCXX_BITS_STD_ABS_H
