1/* s_modff.c -- float version of s_modf.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 <sys/cdefs.h>
17#if defined(LIBM_SCCS) && !defined(lint)
18__RCSID("$NetBSD: s_modff.c,v 1.8 2008/04/25 22:21:53 christos Exp $");
19#endif
20
21#include "math.h"
22#include "math_private.h"
23
24static const float one = 1.0;
25
26float
27modff(float x, float *iptr)
28{
29	int32_t i0,jj0;
30	u_int32_t i;
31	GET_FLOAT_WORD(i0,x);
32	jj0 = ((i0>>23)&0xff)-0x7f;	/* exponent of x */
33	if(jj0<23) {			/* integer part in x */
34	    if(jj0<0) {			/* |x|<1 */
35	        SET_FLOAT_WORD(*iptr,i0&0x80000000);	/* *iptr = +-0 */
36		return x;
37	    } else {
38		i = (0x007fffff)>>jj0;
39		if((i0&i)==0) {			/* x is integral */
40		    u_int32_t ix;
41		    *iptr = x;
42		    GET_FLOAT_WORD(ix,x);
43		    SET_FLOAT_WORD(x,ix&0x80000000);	/* return +-0 */
44		    return x;
45		} else {
46		    SET_FLOAT_WORD(*iptr,i0&(~i));
47		    return x - *iptr;
48		}
49	    }
50	} else {			/* no fraction part */
51	    u_int32_t ix;
52	    *iptr = x*one;
53	    if (jj0 == 0x80)		/* +-inf or NaN */
54		return 0.0 / x;		/* +-0 or NaN */
55	    GET_FLOAT_WORD(ix,x);
56	    SET_FLOAT_WORD(x,ix&0x80000000);	/* return +-0 */
57	    return x;
58	}
59}
60