s_frexpf.c revision 2116 
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#ifndef lint
17static char rcsid[] = "$Id: s_frexpf.c,v 1.2 1994/08/18 23:06:51 jtc Exp $";
18#endif
19
20#include "math.h"
21#include "math_private.h"
22
23#ifdef __STDC__
24static const float
25#else
26static float
27#endif
28one   =  1.0000000000e+00, /* 0x3F800000 */
29two25 =  3.3554432000e+07; /* 0x4c000000 */
30
31#ifdef __STDC__
32	float frexpf(float x, int *eptr)
33#else
34	float frexpf(x, eptr)
35	float x; int *eptr;
36#endif
37{
38	int32_t hx,ix;
39	GET_FLOAT_WORD(hx,x);
40	ix = 0x7fffffff&hx;
41	*eptr = 0;
42	if(ix>=0x7f800000||(ix==0)) return x;	/* 0,inf,nan */
43	if (ix<0x00800000) {		/* subnormal */
44	    x *= two25;
45	    GET_FLOAT_WORD(hx,x);
46	    ix = hx&0x7fffffff;
47	    *eptr = -25;
48	}
49	*eptr += (ix>>23)-126;
50	hx = (hx&0x807fffff)|0x3f000000;
51	*(int*)&x = hx;
52	return x;
53}
54