1/* e_fmodl.c -- long double version of e_fmod.c.
2 * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
3 */
4/*
5 * ====================================================
6 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
7 *
8 * Developed at SunPro, a Sun Microsystems, Inc. business.
9 * Permission to use, copy, modify, and distribute this
10 * software is freely granted, provided that this notice
11 * is preserved.
12 * ====================================================
13 */
14
15/* __ieee754_remainderl(x,p)
16 * Return :
17 * returns x REM p = x - [x/p]*p as if in infinite
18 * precise arithmetic, where [x/p] is the (infinite bit)
19 * integer nearest x/p (in half way case choose the even one).
20 * Method :
21 * Based on fmodl() return x-[x/p]chopped*p exactlp.
22 */
23
24#include <math.h>
25#include <math_private.h>
26
27static const _Float128 zero = 0;
28
29
30_Float128
31__ieee754_remainderl(_Float128 x, _Float128 p)
32{
33 int64_t hx,hp;
34 u_int64_t sx,lx,lp;
35 _Float128 p_half;
36
37 GET_LDOUBLE_WORDS64(hx,lx,x);
38 GET_LDOUBLE_WORDS64(hp,lp,p);
39 sx = hx&0x8000000000000000ULL;
40 hp &= 0x7fffffffffffffffLL;
41 hx &= 0x7fffffffffffffffLL;
42
43 /* purge off exception values */
44 if((hp|lp)==0) return (x*p)/(x*p); /* p = 0 */
45 if((hx>=0x7fff000000000000LL)|| /* x not finite */
46 ((hp>=0x7fff000000000000LL)&& /* p is NaN */
47 (((hp-0x7fff000000000000LL)|lp)!=0)))
48 return (x*p)/(x*p);
49
50
51 if (hp<=0x7ffdffffffffffffLL) x = __ieee754_fmodl(x,p+p); /* now x < 2p */
52 if (((hx-hp)|(lx-lp))==0) return zero*x;
53 x = fabsl(x);
54 p = fabsl(p);
55 if (hp<0x0002000000000000LL) {
56 if(x+x>p) {
57 x-=p;
58 if(x+x>=p) x -= p;
59 }
60 } else {
61 p_half = L(0.5)*p;
62 if(x>p_half) {
63 x-=p;
64 if(x>=p_half) x -= p;
65 }
66 }
67 GET_LDOUBLE_MSW64(hx,x);
68 SET_LDOUBLE_MSW64(x,hx^sx);
69 return x;
70}
71strong_alias (__ieee754_remainderl, __remainderl_finite)
72