1*2fe8fb19SBen Gras /* s_modff.c -- float version of s_modf.c.
2*2fe8fb19SBen Gras * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3*2fe8fb19SBen Gras */
4*2fe8fb19SBen Gras
5*2fe8fb19SBen Gras /*
6*2fe8fb19SBen Gras * ====================================================
7*2fe8fb19SBen Gras * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8*2fe8fb19SBen Gras *
9*2fe8fb19SBen Gras * Developed at SunPro, a Sun Microsystems, Inc. business.
10*2fe8fb19SBen Gras * Permission to use, copy, modify, and distribute this
11*2fe8fb19SBen Gras * software is freely granted, provided that this notice
12*2fe8fb19SBen Gras * is preserved.
13*2fe8fb19SBen Gras * ====================================================
14*2fe8fb19SBen Gras */
15*2fe8fb19SBen Gras
16*2fe8fb19SBen Gras #include <sys/cdefs.h>
17*2fe8fb19SBen Gras #if defined(LIBM_SCCS) && !defined(lint)
18*2fe8fb19SBen Gras __RCSID("$NetBSD: s_modff.c,v 1.9 2010/01/27 14:07:41 drochner Exp $");
19*2fe8fb19SBen Gras #endif
20*2fe8fb19SBen Gras
21*2fe8fb19SBen Gras #include "math.h"
22*2fe8fb19SBen Gras #include "math_private.h"
23*2fe8fb19SBen Gras
24*2fe8fb19SBen Gras static const float one = 1.0;
25*2fe8fb19SBen Gras
26*2fe8fb19SBen Gras float
modff(float x,float * iptr)27*2fe8fb19SBen Gras modff(float x, float *iptr)
28*2fe8fb19SBen Gras {
29*2fe8fb19SBen Gras int32_t i0,jj0;
30*2fe8fb19SBen Gras u_int32_t i;
31*2fe8fb19SBen Gras GET_FLOAT_WORD(i0,x);
32*2fe8fb19SBen Gras jj0 = ((i0>>23)&0xff)-0x7f; /* exponent of x */
33*2fe8fb19SBen Gras if(jj0<23) { /* integer part in x */
34*2fe8fb19SBen Gras if(jj0<0) { /* |x|<1 */
35*2fe8fb19SBen Gras SET_FLOAT_WORD(*iptr,i0&0x80000000); /* *iptr = +-0 */
36*2fe8fb19SBen Gras return x;
37*2fe8fb19SBen Gras } else {
38*2fe8fb19SBen Gras i = (0x007fffff)>>jj0;
39*2fe8fb19SBen Gras if((i0&i)==0) { /* x is integral */
40*2fe8fb19SBen Gras u_int32_t ix;
41*2fe8fb19SBen Gras *iptr = x;
42*2fe8fb19SBen Gras GET_FLOAT_WORD(ix,x);
43*2fe8fb19SBen Gras SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
44*2fe8fb19SBen Gras return x;
45*2fe8fb19SBen Gras } else {
46*2fe8fb19SBen Gras SET_FLOAT_WORD(*iptr,i0&(~i));
47*2fe8fb19SBen Gras return x - *iptr;
48*2fe8fb19SBen Gras }
49*2fe8fb19SBen Gras }
50*2fe8fb19SBen Gras } else { /* no fraction part */
51*2fe8fb19SBen Gras u_int32_t ix;
52*2fe8fb19SBen Gras *iptr = x*one;
53*2fe8fb19SBen Gras if (jj0 == 0x80) /* +-inf or NaN */
54*2fe8fb19SBen Gras return 0.0 / x; /* +-0 or NaN */
55*2fe8fb19SBen Gras GET_FLOAT_WORD(ix,x);
56*2fe8fb19SBen Gras SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
57*2fe8fb19SBen Gras return x;
58*2fe8fb19SBen Gras }
59*2fe8fb19SBen Gras }
60