/* 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;

	uint64_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)