diff options
Diffstat (limited to 'math/w_log2f.c')
| -rw-r--r-- | math/w_log2f.c | 53 |
1 files changed, 34 insertions, 19 deletions
diff --git a/math/w_log2f.c b/math/w_log2f.c index 10d73ffd1b..7c64ad8b81 100644 --- a/math/w_log2f.c +++ b/math/w_log2f.c @@ -1,30 +1,45 @@ -/* - * wrapper log2(X) - */ +/* Copyright (C) 2011 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <fenv.h> #include <math.h> #include <math_private.h> + +/* wrapper log2f(x) */ float -__log2f (float x) /* wrapper log2f */ +__log2f (float x) { -#ifdef _IEEE_LIBM - return __ieee754_log2f (x); -#else - float z; - z = __ieee754_log2f (x); - if (_LIB_VERSION == _IEEE_ || __isnanf (x)) return z; - if (x <= 0.0f) + if (__builtin_expect (x <= 0.0f, 0) && _LIB_VERSION != _IEEE_) { - if (x == 0.0f) - /* log2f (0) */ - return __kernel_standard ((double) x, (double) x, 148); + if (x == 0.0) + { + feraiseexcept (FE_DIVBYZERO); + return __kernel_standard_f (x, x, 148); /* log2(0) */ + } else - /* log2f (x < 0) */ - return __kernel_standard ((double) x, (double) x, 149); + { + feraiseexcept (FE_INVALID); + return __kernel_standard_f (x, x, 149); /* log2(x<0) */ + } } - else - return z; -#endif + + return __ieee754_log2f (x); } weak_alias (__log2f, log2f) |