nsz Git - libm/blob - src/math/ceilf.c

   1 /* origin: FreeBSD /usr/src/lib/msun/src/s_ceilf.c */
   2 /*
   3  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
   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 "libm.h"
  17
  18 static const float huge = 1.0e30;
  19
  20 float ceilf(float x)
  21 {
  22         int32_t i0,j0;
  23         uint32_t i;
  24
  25         GET_FLOAT_WORD(i0, x);
  26         j0 = ((i0>>23)&0xff) - 0x7f;
  27         if (j0 < 23) {
  28                 if (j0 < 0) {
  29                         /* raise inexact if x != 0 */
  30                         if (huge+x > (float)0.0) {
  31                                 /* return 0*sign(x) if |x|<1 */
  32                                 if (i0 < 0)
  33                                         i0 = 0x80000000;
  34                                 else if(i0 != 0)
  35                                         i0 = 0x3f800000;
  36                         }
  37                 } else {
  38                         i = 0x007fffff>>j0;
  39                         if ((i0&i) == 0)
  40                                 return x; /* x is integral */
  41                         /* raise inexact flag */
  42                         if (huge+x > (float)0.0) {
  43                                 if (i0 > 0)
  44                                         i0 += 0x00800000>>j0;
  45                                 i0 &= ~i;
  46                         }
  47                 }
  48         } else {
  49                 if (j0 == 0x80)  /* inf or NaN */
  50                         return x+x;
  51                 return x; /* x is integral */
  52         }
  53         SET_FLOAT_WORD(x, i0);
  54         return x;
  55 }