compiler/stdc/math/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
  16 #ifndef lint
  17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_ceilf.c,v 1.7 2002/05/28 18:15:04 alfred Exp $";
  18 #endif
  19
  20 #include "math.h"
  21 #include "math_private.h"
  22
  23 static const float huge = 1.0e30;
  24
  25 float
  26 ceilf(float x)
  27 {
  28         int32_t i0,j0;
  29         uint32_t i;
  30
  31         GET_FLOAT_WORD(i0,x);
  32         j0 = ((i0>>23)&0xff)-0x7f;
  33         if(j0<23) {
  34             if(j0<0) {  /* raise inexact if x != 0 */
  35                 if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
  36                     if(i0<0) {i0=0x80000000;}
  37                     else if(i0!=0) { i0=0x3f800000;}
  38                 }
  39             } else {
  40                 i = (0x007fffff)>>j0;
  41                 if((i0&i)==0) return x; /* x is integral */
  42                 if(huge+x>(float)0.0) { /* raise inexact flag */
  43                     if(i0>0) i0 += (0x00800000)>>j0;
  44                     i0 &= (~i);
  45                 }
  46             }
  47         } else {
  48             if(j0==0x80) return x+x;    /* inf or NaN */
  49             else return x;              /* x is integral */
  50         }
  51         SET_FLOAT_WORD(x,i0);
  52         return x;
  53 }