POK
frexpf.c
1 /*
2  * POK header
3  *
4  * The following file is a part of the POK project. Any modification should
5  * made according to the POK licence. You CANNOT use this file or a part of
6  * this file is this part of a file for your own project
7  *
8  * For more information on the POK licence, please see our LICENCE FILE
9  *
10  * Please follow the coding guidelines described in doc/CODING_GUIDELINES
11  *
12  * Copyright (c) 2007-2009 POK team
13  *
14  * Created by julien on Fri Jan 30 14:41:34 2009
15  */
16 
17 /* s_frexpf.c -- float version of s_frexp.c.
18  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
19  */
20 
21 /*
22  * ====================================================
23  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
24  *
25  * Developed at SunPro, a Sun Microsystems, Inc. business.
26  * Permission to use, copy, modify, and distribute this
27  * software is freely granted, provided that this notice
28  * is preserved.
29  * ====================================================
30  */
31 
32 #ifdef POK_NEEDS_LIBMATH
33 
34 #include <libm.h>
35 #include "math_private.h"
36 
37 static const float
38 two25 = 3.3554432000e+07; /* 0x4c000000 */
39 
40 float
41 frexpf(float x, int *eptr)
42 {
43  int32_t hx,ix;
44  GET_FLOAT_WORD(hx,x);
45  ix = 0x7fffffff&hx;
46  *eptr = 0;
47  if(ix>=0x7f800000||(ix==0)) return x; /* 0,inf,nan */
48  if (ix<0x00800000) { /* subnormal */
49  x *= two25;
50  GET_FLOAT_WORD(hx,x);
51  ix = hx&0x7fffffff;
52  *eptr = -25;
53  }
54  *eptr += (ix>>23)-126;
55  hx = (hx&0x807fffff)|0x3f000000;
56  SET_FLOAT_WORD(x,hx);
57  return x;
58 }
59 
60 #endif
61