| /* Copyright (C) 2011-2018 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@gmail.com>, 2011. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <errno.h> |
| #include <math.h> |
| #include <math_private.h> |
| #include <math-svid-compat.h> |
| |
| |
| #if LIBM_SVID_COMPAT |
| static double |
| __attribute__ ((noinline)) |
| sysv_scalb (double x, double fn) |
| { |
| double z = __ieee754_scalb (x, fn); |
| |
| if (__glibc_unlikely (isinf (z))) |
| { |
| if (isfinite (x)) |
| return __kernel_standard (x, fn, 32); /* scalb overflow */ |
| else |
| __set_errno (ERANGE); |
| } |
| else if (__builtin_expect (z == 0.0, 0) && z != x) |
| return __kernel_standard (x, fn, 33); /* scalb underflow */ |
| |
| return z; |
| } |
| #endif |
| |
| |
| /* Wrapper scalb */ |
| double |
| __scalb (double x, double fn) |
| { |
| #if LIBM_SVID_COMPAT |
| if (__glibc_unlikely (_LIB_VERSION == _SVID_)) |
| return sysv_scalb (x, fn); |
| else |
| #endif |
| { |
| double z = __ieee754_scalb (x, fn); |
| |
| if (__glibc_unlikely (!isfinite (z) || z == 0.0)) |
| { |
| if (isnan (z)) |
| { |
| if (!isnan (x) && !isnan (fn)) |
| __set_errno (EDOM); |
| } |
| else if (isinf (z)) |
| { |
| if (!isinf (x) && !isinf (fn)) |
| __set_errno (ERANGE); |
| } |
| else |
| { |
| /* z == 0. */ |
| if (x != 0.0 && !isinf (fn)) |
| __set_errno (ERANGE); |
| } |
| } |
| return z; |
| } |
| } |
| weak_alias (__scalb, scalb) |
| #ifdef NO_LONG_DOUBLE |
| strong_alias (__scalb, __scalbl) |
| weak_alias (__scalb, scalbl) |
| #endif |