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 #ifndef lint
17 static char rcsid[] = "$FreeBSD: src/lib/msun/src/s_modff.c,v 1.7 2002/05/28 18:15:04 alfred Exp $";
18 #endif
19
20 #include "math.h"
21 #include "math_private.h"
22
23 static const float one = 1.0;
24
25 float
modff(float x,float * iptr)26 modff(float x, float *iptr)
27 {
28 int32_t i0,j0;
29 u_int32_t i;
30 GET_FLOAT_WORD(i0,x);
31 j0 = ((i0>>23)&0xff)-0x7f; /* exponent of x */
32 if(j0<23) { /* integer part in x */
33 if(j0<0) { /* |x|<1 */
34 SET_FLOAT_WORD(*iptr,i0&0x80000000); /* *iptr = +-0 */
35 return x;
36 } else {
37 i = (0x007fffff)>>j0;
38 if((i0&i)==0) { /* x is integral */
39 u_int32_t ix;
40 *iptr = x;
41 GET_FLOAT_WORD(ix,x);
42 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
43 return x;
44 } else {
45 SET_FLOAT_WORD(*iptr,i0&(~i));
46 return x - *iptr;
47 }
48 }
49 } else { /* no fraction part */
50 u_int32_t ix;
51 *iptr = x*one;
52 GET_FLOAT_WORD(ix,x);
53 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
54 return x;
55 }
56 }
57