modules/fdlibm/src/s_ceilf.cpp

   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 //__FBSDID("$FreeBSD$");
  18
  19 #include "math_private.h"
  20
  21 static const float huge = 1.0e30;
  22
  23 float
  24 ceilf(float x)
  25 {
  26         int32_t i0,j0;
  27         u_int32_t i;
  28
  29         GET_FLOAT_WORD(i0,x);
  30         j0 = ((i0>>23)&0xff)-0x7f;
  31         if(j0<23) {
  32             if(j0<0) {  /* raise inexact if x != 0 */
  33                 if(huge+x>(float)0.0) {/* return 0*sign(x) if |x|<1 */
  34                     if(i0<0) {i0=0x80000000;}
  35                     else if(i0!=0) { i0=0x3f800000;}
  36                 }
  37             } else {
  38                 i = (0x007fffff)>>j0;
  39                 if((i0&i)==0) return x; /* x is integral */
  40                 if(huge+x>(float)0.0) { /* raise inexact flag */
  41                     if(i0>0) i0 += (0x00800000)>>j0;
  42                     i0 &= (~i);
  43                 }
  44             }
  45         } else {
  46             if(j0==0x80) return x+x;    /* inf or NaN */
  47             else return x;              /* x is integral */
  48         }
  49         SET_FLOAT_WORD(x,i0);
  50         return x;
  51 }