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("$MirOS: src/lib/libm/src/s_modff.c,v 1.3 2011/10/18 19:46:29 bsiegert Exp $");
19 __RCSID("$NetBSD: s_modff.c,v 1.9 2010/01/27 14:07:41 drochner Exp $");
20 #endif
21
22 #include "math.h"
23 #include "math_private.h"
24
25 static const float one = 1.0;
26
27 float
modff(float x,float * iptr)28 modff(float x, float *iptr)
29 {
30 int32_t i0,jj0;
31 u_int32_t i;
32 GET_FLOAT_WORD(i0,x);
33 jj0 = ((i0>>23)&0xff)-0x7f; /* exponent of x */
34 if(jj0<23) { /* integer part in x */
35 if(jj0<0) { /* |x|<1 */
36 SET_FLOAT_WORD(*iptr,i0&0x80000000); /* *iptr = +-0 */
37 return x;
38 } else {
39 i = (0x007fffff)>>jj0;
40 if((i0&i)==0) { /* x is integral */
41 u_int32_t ix;
42 *iptr = x;
43 GET_FLOAT_WORD(ix,x);
44 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
45 return x;
46 } else {
47 SET_FLOAT_WORD(*iptr,i0&(~i));
48 return x - *iptr;
49 }
50 }
51 } else { /* no fraction part */
52 u_int32_t ix;
53 *iptr = x*one;
54 if (jj0 == 0x80) /* +-inf or NaN */
55 return 0.0 / x; /* +-0 or NaN */
56 GET_FLOAT_WORD(ix,x);
57 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
58 return x;
59 }
60 }
61