sysdeps/ieee754/flt-32/s_frexpf.c

   1 /* s_frexpf.c -- float version of s_frexp.c.
   2  */
   3
   4 /*
   5  * ====================================================
   6  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   7  *
   8  * Developed at SunPro, a Sun Microsystems, Inc. business.
   9  * Permission to use, copy, modify, and distribute this
  10  * software is freely granted, provided that this notice
  11  * is preserved.
  12  * ====================================================
  13  */
  14
  15 #if defined(LIBM_SCCS) && !defined(lint)
  16 static char rcsid[] = "$NetBSD: s_frexpf.c,v 1.5 1995/05/10 20:47:26 jtc Exp $";
  17 #endif
  18
  19 #include <math.h>
  20 #include <math_private.h>
  21 #include <libm-alias-float.h>
  22
  23 static const float
  24 two25 =  3.3554432000e+07; /* 0x4c000000 */
  25
  26 float __frexpf(float x, int *eptr)
  27 {
  28         int32_t hx,ix;
  29         GET_FLOAT_WORD(hx,x);
  30         ix = 0x7fffffff&hx;
  31         *eptr = 0;
  32         if(ix>=0x7f800000||(ix==0)) return x + x;       /* 0,inf,nan */
  33         if (ix<0x00800000) {            /* subnormal */
  34             x *= two25;
  35             GET_FLOAT_WORD(hx,x);
  36             ix = hx&0x7fffffff;
  37             *eptr = -25;
  38         }
  39         *eptr += (ix>>23)-126;
  40         hx = (hx&0x807fffff)|0x3f000000;
  41         SET_FLOAT_WORD(x,hx);
  42         return x;
  43 }
  44 libm_alias_float (__frexp, frexp)