POK
/home/jaouen/pok_official/pok/trunk/libpok/libm/gammaf.c
00001 /*
00002  *                               POK header
00003  * 
00004  * The following file is a part of the POK project. Any modification should
00005  * made according to the POK licence. You CANNOT use this file or a part of
00006  * this file is this part of a file for your own project
00007  *
00008  * For more information on the POK licence, please see our LICENCE FILE
00009  *
00010  * Please follow the coding guidelines described in doc/CODING_GUIDELINES
00011  *
00012  *                                      Copyright (c) 2007-2009 POK team 
00013  *
00014  * Created by julien on Fri Jan 30 14:41:34 2009 
00015  */
00016 
00017 /* w_gammaf.c -- float version of w_gamma.c.
00018  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
00019  */
00020 
00021 /*
00022  * ====================================================
00023  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
00024  *
00025  * Developed at SunPro, a Sun Microsystems, Inc. business.
00026  * Permission to use, copy, modify, and distribute this
00027  * software is freely granted, provided that this notice
00028  * is preserved.
00029  * ====================================================
00030  */
00031 
00032 #ifdef POK_NEEDS_LIBMATH
00033 
00034 #include <libm.h>
00035 #include "math_private.h"
00036 
00037 float
00038 gammaf(float x)
00039 {
00040 #ifdef _IEEE_LIBM
00041         return __ieee754_lgammaf_r(x,&signgam);
00042 #else
00043         float y;
00044         y = __ieee754_lgammaf_r(x,&signgam);
00045         if(_LIB_VERSION == _IEEE_) return y;
00046         if(!finitef(y)&&finitef(x)) {
00047             if(floorf(x)==x&&x<=(float)0.0)
00048                 /* gammaf pole */
00049                 return (float)__kernel_standard((double)x,(double)x,141);
00050             else
00051                 /* gammaf overflow */
00052                 return (float)__kernel_standard((double)x,(double)x,140);
00053         } else
00054             return y;
00055 #endif
00056 }
00057 
00058 #endif