diff options
Diffstat (limited to 'math/w_pow.c')
| -rw-r--r-- | math/w_pow.c | 111 |
1 files changed, 60 insertions, 51 deletions
diff --git a/math/w_pow.c b/math/w_pow.c index e0d2a92847..4993c232a6 100644 --- a/math/w_pow.c +++ b/math/w_pow.c @@ -1,67 +1,76 @@ +/* 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. -/* @(#)w_pow.c 5.2 93/10/01 */ -/* - * ==================================================== - * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. - * - * Developed at SunPro, a Sun Microsystems, Inc. business. - * Permission to use, copy, modify, and distribute this - * software is freely granted, provided that this notice - * is preserved. - * ==================================================== - */ + 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. -/* - * wrapper pow(x,y) return x**y - */ + 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 <math.h> #include <math_private.h> -#ifdef __STDC__ - double __pow(double x, double y) /* wrapper pow */ -#else - double __pow(x,y) /* wrapper pow */ - double x,y; -#endif +/* wrapper pow */ +double +__pow (double x, double y) { -#ifdef _IEEE_LIBM - return __ieee754_pow(x,y); -#else - double z; - z=__ieee754_pow(x,y); - if(_LIB_VERSION == _IEEE_|| __isnan(y)) return z; - if(__isnan(x)) { - if(y==0.0) - return __kernel_standard(x,y,42); /* pow(NaN,0.0) */ - else - return z; - } - if(x==0.0) { - if(y==0.0) - return __kernel_standard(x,y,20); /* pow(0.0,0.0) */ - if(__finite(y)&&y<0.0) { - if (signbit (x) && signbit (z)) - return __kernel_standard(x,y,23); /* pow(-0.0,negative) */ + double z = __ieee754_pow (x, y); + if (__builtin_expect (!__finite (z), 0)) + { + if (_LIB_VERSION != _IEEE_) + { + if (__isnan (x)) + { + if (y == 0.0) + /* pow(NaN,0.0) */ + return __kernel_standard (x, y, 42); + } + else if (__finite (x) && __finite (y)) + { + if (__isnan (z)) + /* pow neg**non-int */ + return __kernel_standard (x, y, 24); + else if (x == 0.0 && y < 0.0) + { + if (signbit (x) && signbit (z)) + /* pow(-0.0,negative) */ + return __kernel_standard (x, y, 23); + else + /* pow(+0.0,negative) */ + return __kernel_standard (x, y, 43); + } else - return __kernel_standard(x,y,43); /* pow(+0.0,negative) */ + /* pow overflow */ + return __kernel_standard (x, y, 21); } - return z; } - if(!__finite(z)) { - if(__finite(x)&&__finite(y)) { - if(__isnan(z)) - return __kernel_standard(x,y,24); /* pow neg**non-int */ - else - return __kernel_standard(x,y,21); /* pow overflow */ - } + } + else if (__builtin_expect (z == 0.0, 0) && __finite (x) && __finite (y) + && _LIB_VERSION != _IEEE_) + { + if (x == 0.0) + { + if (y == 0.0) + /* pow(0.0,0.0) */ + return __kernel_standard (x, y, 20); } - if(z==0.0&&__finite(x)&&__finite(y)) - return __kernel_standard(x,y,22); /* pow underflow */ - return z; -#endif + else + /* pow underflow */ + return __kernel_standard (x, y, 22); + } + + return z; } weak_alias (__pow, pow) #ifdef NO_LONG_DOUBLE |