contrib/openbsd_libm/src/s_frexpf.c

   1 /* s_frexpf.c -- float version of s_frexp.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 "math.h"
  17 #include "math_private.h"
  18
  19 static const float
  20 two25 =  3.3554432000e+07; /* 0x4c000000 */
  21
  22 float
  23 frexpf(float x, int *eptr)
  24 {
  25         int32_t hx,ix;
  26         GET_FLOAT_WORD(hx,x);
  27         ix = 0x7fffffff&hx;
  28         *eptr = 0;
  29         if(ix>=0x7f800000||(ix==0)) return x;   /* 0,inf,nan */
  30         if (ix<0x00800000) {            /* subnormal */
  31             x *= two25;
  32             GET_FLOAT_WORD(hx,x);
  33             ix = hx&0x7fffffff;
  34             *eptr = -25;
  35         }
  36         *eptr += (ix>>23)-126;
  37         hx = (hx&0x807fffff)|0x3f000000;
  38         SET_FLOAT_WORD(x,hx);
  39         return x;
  40 }