POK
/home/jaouen/pok_official/pok/trunk/libpok/libm/ceilf.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 /* s_ceilf.c -- float version of s_ceil.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 #ifdef POK_NEEDS_LIBMATH
00032 #include <libm.h>
00033 #include "math_private.h"
00034 
00035 static const float huge = 1.0e30;
00036 
00037 float
00038 ceilf(float x)
00039 {
00040         int32_t i0,jj0;
00041         uint32_t i;
00042 
00043         GET_FLOAT_WORD(i0,x);
00044         jj0 = ((i0>>23)&0xff)-0x7f;
00045         if(jj0<23) {
00046             if(jj0<0) {         /* raise inexact if x != 0 */
00047                 if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
00048                     if(i0<0) {i0=0x80000000;}
00049                     else if(i0!=0) { i0=0x3f800000;}
00050                 }
00051             } else {
00052                 i = (0x007fffff)>>jj0;
00053                 if((i0&i)==0) return x; /* x is integral */
00054                 if(huge+x>(float)0.0) { /* raise inexact flag */
00055                     if(i0>0) i0 += (0x00800000)>>jj0;
00056                     i0 &= (~i);
00057                 }
00058             }
00059         } else {
00060             if(jj0==0x80) return x+x;   /* inf or NaN */
00061             else return x;              /* x is integral */
00062         }
00063         SET_FLOAT_WORD(x,i0);
00064         return x;
00065 }
00066 
00067 #endif