1 /* e_remainderf.c -- float version of e_remainder.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 zero = 0.0;
23
24
25 float
__ieee754_remainderf(float x,float p)26 __ieee754_remainderf(float x, float p)
27 {
28 int32_t hx,hp;
29 u_int32_t sx;
30 float p_half;
31
32 GET_FLOAT_WORD(hx,x);
33 GET_FLOAT_WORD(hp,p);
34 sx = hx&0x80000000;
35 hp &= 0x7fffffff;
36 hx &= 0x7fffffff;
37
38 /* purge off exception values */
39 if((hp==0)|| /* p = 0 */
40 (hx>=0x7f800000)|| /* x not finite */
41 ((hp>0x7f800000))) /* p is NaN */
42 return nan_mix_op(x, p, *)/nan_mix_op(x, p, *);
43
44
45 if (hp<=0x7effffff) x = __ieee754_fmodf(x,p+p); /* now x < 2p */
46 if ((hx-hp)==0) return zero*x;
47 x = fabsf(x);
48 p = fabsf(p);
49 if (hp<0x01000000) {
50 if(x+x>p) {
51 x-=p;
52 if(x+x>=p) x -= p;
53 }
54 } else {
55 p_half = (float)0.5*p;
56 if(x>p_half) {
57 x-=p;
58 if(x>=p_half) x -= p;
59 }
60 }
61 GET_FLOAT_WORD(hx,x);
62 if ((hx&0x7fffffff)==0) hx = 0;
63 SET_FLOAT_WORD(x,hx^sx);
64 return x;
65 }
66