1 /* @(#)e_remainder.c 5.1 93/09/24 */
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
10 * ====================================================
14 static char rcsid[] = "$FreeBSD$";
17 /* __ieee754_remainder(x,p)
19 * returns x REM p = x - [x/p]*p as if in infinite
20 * precise arithmetic, where [x/p] is the (infinite bit)
21 * integer nearest x/p (in half way case choose the even one).
23 * Based on fmod() return x-[x/p]chopped*p exactlp.
27 #include "math_private.h"
29 static const double zero = 0.0;
33 __ieee754_remainder(double x, double p)
39 EXTRACT_WORDS(hx,lx,x);
40 EXTRACT_WORDS(hp,lp,p);
45 /* purge off exception values */
46 if((hp|lp)==0) return (x*p)/(x*p); /* p = 0 */
47 if((hx>=0x7ff00000)|| /* x not finite */
48 ((hp>=0x7ff00000)&& /* p is NaN */
49 (((hp-0x7ff00000)|lp)!=0)))
53 if (hp<=0x7fdfffff) x = __ieee754_fmod(x,p+p); /* now x < 2p */
54 if (((hx-hp)|(lx-lp))==0) return zero*x;
70 SET_HIGH_WORD(x,hx^sx);