1 /* Wrapper to set errno for log2. 2 Copyright (C) 2017-2022 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 /* Only build wrappers from the templates for the types that define the macro 20 below. This macro is set in math-type-macros-<type>.h in sysdeps/generic 21 for each floating-point type. */ 22 #if __USE_WRAPPER_TEMPLATE 23 24 # include <errno.h> 25 # include <fenv.h> 26 # include <math.h> 27 # include <math_private.h> 28 29 FLOAT M_DECL_FUNC(__log2)30M_DECL_FUNC (__log2) (FLOAT x) 31 { 32 if (__glibc_unlikely (islessequal (x, M_LIT (0.0)))) 33 { 34 if (x == 0) 35 /* Pole error: log2(0). */ 36 __set_errno (ERANGE); 37 else 38 /* Domain error: log2(<0). */ 39 __set_errno (EDOM); 40 } 41 return M_SUF (__ieee754_log2) (x); 42 } 43 declare_mgen_alias (__log2, log2) 44 45 #endif /* __USE_WRAPPER_TEMPLATE. */ 46