| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Copyright (C) 2011-2016 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | Contributed by Ulrich Drepper <drepper@gmail.com>, 2011. |
| 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 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include <errno.h> |
| 20 | #include <math.h> |
| 21 | #include <math_private.h> |
| 22 | |
| 23 | |
| 24 | static double |
| 25 | __attribute__ ((noinline)) |
| 26 | sysv_scalb (double x, double fn) |
| 27 | { |
| 28 | double z = __ieee754_scalb (x, fn); |
| 29 | |
| 30 | if (__glibc_unlikely (isinf (z))) |
| 31 | { |
| 32 | if (isfinite (x)) |
| 33 | return __kernel_standard (x, fn, 32); /* scalb overflow */ |
| 34 | else |
| 35 | __set_errno (ERANGE); |
| 36 | } |
| 37 | else if (__builtin_expect (z == 0.0, 0) && z != x) |
| 38 | return __kernel_standard (x, fn, 33); /* scalb underflow */ |
| 39 | |
| 40 | return z; |
| 41 | } |
| 42 | |
| 43 | |
| 44 | /* Wrapper scalb */ |
| 45 | double |
| 46 | __scalb (double x, double fn) |
| 47 | { |
| 48 | if (__glibc_unlikely (_LIB_VERSION == _SVID_)) |
| 49 | return sysv_scalb (x, fn); |
| 50 | else |
| 51 | { |
| 52 | double z = __ieee754_scalb (x, fn); |
| 53 | |
| 54 | if (__glibc_unlikely (!isfinite (z) || z == 0.0)) |
| 55 | { |
| 56 | if (isnan (z)) |
| 57 | { |
| 58 | if (!isnan (x) && !isnan (fn)) |
| 59 | __set_errno (EDOM); |
| 60 | } |
| 61 | else if (isinf (z)) |
| 62 | { |
| 63 | if (!isinf (x) && !isinf (fn)) |
| 64 | __set_errno (ERANGE); |
| 65 | } |
| 66 | else |
| 67 | { |
| 68 | /* z == 0. */ |
| 69 | if (x != 0.0 && !isinf (fn)) |
| 70 | __set_errno (ERANGE); |
| 71 | } |
| 72 | } |
| 73 | return z; |
| 74 | } |
| 75 | } |
| 76 | weak_alias (__scalb, scalb) |
| 77 | #ifdef NO_LONG_DOUBLE |
| 78 | strong_alias (__scalb, __scalbl) |
| 79 | weak_alias (__scalb, scalbl) |
| 80 | #endif |