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
  16 #include <sys/cdefs.h>
  17 #if defined(LIBM_SCCS) && !defined(lint)
  18 __RCSID("$NetBSD: s_ceilf.c,v 1.8 2008/04/25 22:21:53 christos Exp $");
  19 #endif
  20
  21 #include "math.h"
  22 #include "math_private.h"
  23
  24 static const float huge = 1.0e30;
  25
  26 float
  27 ceilf(float x)
  28 {
  29         int32_t i0,jj0;
  30         u_int32_t i;
  31
  32         GET_FLOAT_WORD(i0,x);
  33         jj0 = ((i0>>23)&0xff)-0x7f;
  34         if(jj0<23) {
  35             if(jj0<0) {         /* raise inexact if x != 0 */
  36                 if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
  37                     if(i0<0) {i0=0x80000000;}
  38                     else if(i0!=0) { i0=0x3f800000;}
  39                 }
  40             } else {
  41                 i = (0x007fffff)>>jj0;
  42                 if((i0&i)==0) return x; /* x is integral */
  43                 if(huge+x>(float)0.0) { /* raise inexact flag */
  44                     if(i0>0) i0 += (0x00800000)>>jj0;
  45                     i0 &= (~i);
  46                 }
  47             }
  48         } else {
  49             if(jj0==0x80) return x+x;   /* inf or NaN */
  50             else return x;              /* x is integral */
  51         }
  52         SET_FLOAT_WORD(x,i0);
  53         return x;
  54 }