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/* e_fmodl.c -- long double version of e_fmod.c.
* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/* __ieee754_remainderl(x,p)
* Return :
* returns x REM p = x - [x/p]*p as if in infinite
* precise arithmetic, where [x/p] is the (infinite bit)
* integer nearest x/p (in half way case choose the even one).
* Method :
* Based on fmodl() return x-[x/p]chopped*p exactlp.
*/
#include <math.h>
#include <math_private.h>
static const long double zero = 0.0L;
long double
__ieee754_remainderl(long double x, long double p)
{
int64_t hx,hp;
u_int64_t sx,lx,lp;
long double p_half;
double xhi, xlo, phi, plo;
ldbl_unpack (x, &xhi, &xlo);
EXTRACT_WORDS64 (hx, xhi);
EXTRACT_WORDS64 (lx, xlo);
ldbl_unpack (p, &phi, &plo);
EXTRACT_WORDS64 (hp, phi);
EXTRACT_WORDS64 (lp, plo);
sx = hx&0x8000000000000000ULL;
lp ^= hp & 0x8000000000000000ULL;
hp &= 0x7fffffffffffffffLL;
lx ^= sx;
hx &= 0x7fffffffffffffffLL;
if (lp == 0x8000000000000000ULL)
lp = 0;
if (lx == 0x8000000000000000ULL)
lx = 0;
/* purge off exception values */
if(hp==0) return (x*p)/(x*p); /* p = 0 */
if((hx>=0x7ff0000000000000LL)|| /* x not finite */
(hp>0x7ff0000000000000LL)) /* p is NaN */
return (x*p)/(x*p);
if (hp<=0x7fdfffffffffffffLL) x = __ieee754_fmodl(x,p+p); /* now x < 2p */
if (((hx-hp)|(lx-lp))==0) return zero*x;
x = fabsl(x);
p = fabsl(p);
if (hp<0x0020000000000000LL) {
if(x+x>p) {
x-=p;
if(x+x>=p) x -= p;
}
} else {
p_half = 0.5L*p;
if(x>p_half) {
x-=p;
if(x>=p_half) x -= p;
}
}
if (sx)
x = -x;
return x;
}
strong_alias (__ieee754_remainderl, __remainderl_finite)
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