1 /* Wrapper to set errno for pow. 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(__pow)30M_DECL_FUNC (__pow) (FLOAT x, FLOAT y) 31 { 32 FLOAT z = M_SUF (__ieee754_pow) (x, y); 33 if (__glibc_unlikely (!isfinite (z))) 34 { 35 if (isfinite (x) && isfinite (y)) 36 { 37 if (isnan (z)) 38 /* Domain error: pow(x<0,y=non-integer). */ 39 __set_errno (EDOM); 40 else 41 /* Pole error: pow(x=0,y<0). Or overflow. */ 42 __set_errno (ERANGE); 43 } 44 } 45 else if (__glibc_unlikely (z == 0) && isfinite (x) && x != 0 && isfinite (y)) 46 /* Underflow. */ 47 __set_errno (ERANGE); 48 return z; 49 } 50 declare_mgen_alias (__pow, pow) 51 52 #endif /* __USE_WRAPPER_TEMPLATE. */ 53