lib/libm/src/s_ceilf.c

   1 /* s_ceilf.c -- float version of s_ceil.c.
   2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
   3  */
   4
   5 /*
   6  * ====================================================
   7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   8  *
   9  * Developed at SunPro, a Sun Microsystems, Inc. business.
  10  * Permission to use, copy, modify, and distribute this
  11  * software is freely granted, provided that this notice
  12  * is preserved.
  13  * ====================================================
  14  *
  15  * $NetBSD: s_ceilf.c,v 1.7 2002/05/26 22:01:54 wiz Exp $
  16  * $DragonFly: src/lib/libm/src/s_ceilf.c,v 1.1 2005/07/26 21:15:20 joerg Exp $
  17  */
  18
  19 #include <math.h>
  20 #include "math_private.h"
  21
  22 static const float huge = 1.0e30;
  23
  24 float
  25 ceilf(float x)
  26 {
  27         int32_t i0,j0;
  28         u_int32_t i;
  29
  30         GET_FLOAT_WORD(i0,x);
  31         j0 = ((i0>>23)&0xff)-0x7f;
  32         if(j0<23) {
  33             if(j0<0) {  /* raise inexact if x != 0 */
  34                 if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
  35                     if(i0<0) {i0=0x80000000;}
  36                     else if(i0!=0) { i0=0x3f800000;}
  37                 }
  38             } else {
  39                 i = (0x007fffff)>>j0;
  40                 if((i0&i)==0) return x; /* x is integral */
  41                 if(huge+x>(float)0.0) { /* raise inexact flag */
  42                     if(i0>0) i0 += (0x00800000)>>j0;
  43                     i0 &= (~i);
  44                 }
  45             }
  46         } else {
  47             if(j0==0x80) return x+x;    /* inf or NaN */
  48             else return x;              /* x is integral */
  49         }
  50         SET_FLOAT_WORD(x,i0);
  51         return x;
  52 }