aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/ieee754/flt-32/s_frexpf.c
blob: b7403bf0d8f48f895c59180be347f6a1aabfb8c4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
/* s_frexpf.c -- float version of s_frexp.c.
 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
 */

/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, a Sun Microsystems, Inc. business.
 * Permission to use, copy, modify, and distribute this
 * software is freely granted, provided that this notice
 * is preserved.
 * ====================================================
 */

#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: s_frexpf.c,v 1.5 1995/05/10 20:47:26 jtc Exp $";
#endif

#include <math.h>
#include <math_private.h>
#include <libm-alias-float.h>

static const float
two25 =  3.3554432000e+07; /* 0x4c000000 */

float __frexpf(float x, int *eptr)
{
	int32_t hx,ix;
	GET_FLOAT_WORD(hx,x);
	ix = 0x7fffffff&hx;
	*eptr = 0;
	if(ix>=0x7f800000||(ix==0)) return x + x;	/* 0,inf,nan */
	if (ix<0x00800000) {		/* subnormal */
	    x *= two25;
	    GET_FLOAT_WORD(hx,x);
	    ix = hx&0x7fffffff;
	    *eptr = -25;
	}
	*eptr += (ix>>23)-126;
	hx = (hx&0x807fffff)|0x3f000000;
	SET_FLOAT_WORD(x,hx);
	return x;
}
libm_alias_float (__frexp, frexp)