Where Online Learning is simpler!
The C and C++ Include Header Files
cat -n /usr/include/x86_64-linux-gnu/bits/floatn.h
1 /* Macros to control TS 18661-3 glibc features on x86. 2 Copyright (C) 2017-2026 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 5 The GNU C Library is free software; you can redistribute it and/or 6 modify it under the terms of the GNU Lesser General Public 7 License as published by the Free Software Foundation; either 8 version 2.1 of the License, or (at your option) any later version. 9 10 The GNU C Library is distributed in the hope that it will be useful, 11 but WITHOUT ANY WARRANTY; without even the implied warranty of 12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 Lesser General Public License for more details. 14 15 You should have received a copy of the GNU Lesser General Public 16 License along with the GNU C Library; if not, see 17 <https://www.gnu.org/licenses/>. */ 18 19 #ifndef _BITS_FLOATN_H 20 #define _BITS_FLOATN_H 21 22 #include <features.h> 23 24 /* Defined to 1 if the current compiler invocation provides a 25 floating-point type with the IEEE 754 binary128 format, and this 26 glibc includes corresponding *f128 interfaces for it. The required 27 libgcc support was added some time after the basic compiler 28 support, for x86_64 and x86. Intel SYCL compiler doesn't support 29 _Float128: https://github.com/intel/llvm/issues/16903 30 */ 31 #if (defined __x86_64__ \ 32 ? __GNUC_PREREQ (4, 3) \ 33 : (defined __GNU__ ? __GNUC_PREREQ (4, 5) : __GNUC_PREREQ (4, 4))) \ 34 || (__glibc_clang_prereq (3, 9) \ 35 && (!defined __INTEL_LLVM_COMPILER \ 36 || !defined SYCL_LANGUAGE_VERSION)) 37 # define __HAVE_FLOAT128 1 38 #else 39 # define __HAVE_FLOAT128 0 40 #endif 41 42 /* Defined to 1 if __HAVE_FLOAT128 is 1 and the type is ABI-distinct 43 from the default float, double and long double types in this glibc. */ 44 #if __HAVE_FLOAT128 45 # define __HAVE_DISTINCT_FLOAT128 1 46 #else 47 # define __HAVE_DISTINCT_FLOAT128 0 48 #endif 49 50 /* Defined to 1 if the current compiler invocation provides a 51 floating-point type with the right format for _Float64x, and this 52 glibc includes corresponding *f64x interfaces for it. */ 53 #define __HAVE_FLOAT64X 1 54 55 /* Defined to 1 if __HAVE_FLOAT64X is 1 and _Float64x has the format 56 of long double. Otherwise, if __HAVE_FLOAT64X is 1, _Float64x has 57 the format of _Float128, which must be different from that of long 58 double. */ 59 #define __HAVE_FLOAT64X_LONG_DOUBLE 1 60 61 #ifndef __ASSEMBLER__ 62 63 /* Defined to concatenate the literal suffix to be used with _Float128 64 types, if __HAVE_FLOAT128 is 1. */ 65 # if __HAVE_FLOAT128 66 # if !__GNUC_PREREQ (7, 0) \ 67 || (defined __cplusplus && !__GNUC_PREREQ (13, 0)) \ 68 || defined __clang__ 69 /* The literal suffix f128 exists only since GCC 7.0. */ 70 # define __f128(x) x##q 71 # else 72 # define __f128(x) x##f128 73 # endif 74 # endif 75 76 /* Defined to a complex binary128 type if __HAVE_FLOAT128 is 1. */ 77 # if __HAVE_FLOAT128 78 # if !__GNUC_PREREQ (7, 0) \ 79 || (defined __cplusplus && !__GNUC_PREREQ (13, 0)) \ 80 || defined __clang__ 81 /* Add a typedef for older GCC compilers which don't natively support 82 _Complex _Float128. */ 83 typedef _Complex float __cfloat128 __attribute__ ((__mode__ (__TC__))); 84 # define __CFLOAT128 __cfloat128 85 # else 86 # define __CFLOAT128 _Complex _Float128 87 # endif 88 # endif 89 90 /* The remaining of this file provides support for older compilers. */ 91 # if __HAVE_FLOAT128 92 93 /* The type _Float128 exists only since GCC 7.0. */ 94 # if !__GNUC_PREREQ (7, 0) \ 95 || (defined __cplusplus && !__GNUC_PREREQ (13, 0)) \ 96 || __glibc_clang_prereq (3, 9) 97 typedef __float128 _Float128; 98 # endif 99 100 /* __builtin_huge_valf128 doesn't exist before GCC 7.0 nor Clang 7.0. */ 101 # if !__GNUC_PREREQ (7, 0) && !__glibc_clang_prereq (7, 0) 102 # define __builtin_huge_valf128() ((_Float128) __builtin_huge_val ()) 103 # endif 104 105 /* Older GCC has only a subset of built-in functions for _Float128 on 106 x86, and __builtin_infq is not usable in static initializers. 107 Converting a narrower sNaN to _Float128 produces a quiet NaN, so 108 attempts to use _Float128 sNaNs will not work properly with older 109 compilers. */ 110 # if !__GNUC_PREREQ (7, 0) && !defined __clang__ 111 # define __builtin_copysignf128 __builtin_copysignq 112 # define __builtin_fabsf128 __builtin_fabsq 113 # define __builtin_inff128() ((_Float128) __builtin_inf ()) 114 # define __builtin_nanf128(x) ((_Float128) __builtin_nan (x)) 115 # define __builtin_nansf128(x) ((_Float128) __builtin_nans (x)) 116 # endif 117 118 /* In math/math.h, __MATH_TG will expand signbit to __builtin_signbit*, 119 e.g.: __builtin_signbitf128, before GCC 6. However, there has never 120 been a __builtin_signbitf128 in GCC and the type-generic builtin is 121 only available since GCC 6. signbit is expanded to __builtin_signbit 122 after Clang 3.3. */ 123 # if !__GNUC_PREREQ (6, 0) 124 # define __builtin_signbitf128 __signbitf128 125 # endif 126 127 # endif 128 129 #endif /* !__ASSEMBLER__. */ 130 131 #include <bits/floatn-common.h> 132 133 #endif /* _BITS_FLOATN_H */
