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 "math.h"
17 #include "math_private.h"
18 
19 static const float zero = 0.0;
20 
21 float
22 remainderf(float x, float p)
23 {
24 	int32_t hx,hp;
25 	u_int32_t sx;
26 	float p_half;
27 
28 	GET_FLOAT_WORD(hx,x);
29 	GET_FLOAT_WORD(hp,p);
30 	sx = hx&0x80000000;
31 	hp &= 0x7fffffff;
32 	hx &= 0x7fffffff;
33 
34     /* purge off exception values */
35 	if(hp==0) return (x*p)/(x*p);	 	/* p = 0 */
36 	if((hx>=0x7f800000)||			/* x not finite */
37 	  ((hp>0x7f800000)))			/* p is NaN */
38 	    return (x*p)/(x*p);
39 
40 
41 	if (hp<=0x7effffff) x = fmodf(x,p+p);	/* now x < 2p */
42 	if ((hx-hp)==0) return zero*x;
43 	x  = fabsf(x);
44 	p  = fabsf(p);
45 	if (hp<0x01000000) {
46 	    if(x+x>p) {
47 		x-=p;
48 		if(x+x>=p) x -= p;
49 	    }
50 	} else {
51 	    p_half = (float)0.5*p;
52 	    if(x>p_half) {
53 		x-=p;
54 		if(x>=p_half) x -= p;
55 	    }
56 	}
57 	GET_FLOAT_WORD(hx,x);
58 	SET_FLOAT_WORD(x,hx^sx);
59 	return x;
60 }
61