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 __FBSDID("$FreeBSD$");
18
19 #include "math.h"
20 #include "math_private.h"
21
22 static const float one = 1.0;
23
24 float
modff(float x,float * iptr)25 modff(float x, float *iptr)
26 {
27 int32_t i0,j0;
28 u_int32_t i;
29 GET_FLOAT_WORD(i0,x);
30 j0 = ((i0>>23)&0xff)-0x7f; /* exponent of x */
31 if(j0<23) { /* integer part in x */
32 if(j0<0) { /* |x|<1 */
33 SET_FLOAT_WORD(*iptr,i0&0x80000000); /* *iptr = +-0 */
34 return x;
35 } else {
36 i = (0x007fffff)>>j0;
37 if((i0&i)==0) { /* x is integral */
38 u_int32_t ix;
39 *iptr = x;
40 GET_FLOAT_WORD(ix,x);
41 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
42 return x;
43 } else {
44 SET_FLOAT_WORD(*iptr,i0&(~i));
45 return x - *iptr;
46 }
47 }
48 } else { /* no fraction part */
49 u_int32_t ix;
50 *iptr = x*one;
51 if (x != x) /* NaN */
52 return x;
53 GET_FLOAT_WORD(ix,x);
54 SET_FLOAT_WORD(x,ix&0x80000000); /* return +-0 */
55 return x;
56 }
57 }
58