/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma weak __remainderl = remainderl
#include "libm.h"
#include "longdouble.h"
/*
* remainderl(x,p)
* returns x REM p = x - [x/p]*p as if in infinite
* precise arithmetic, where [x/p] is the (inifinite bit)
* integer nearest x/p (in half way case choose the even one).
* Method :
* Based on fmodl() return x-[x/p]chopped*p exactly.
*/
#define HFMAX 5.948657476786158825428796633140035080982e+4931L
#define DBMIN 6.724206286224187012525355634643505205196e-4932L
static const long double
zero = 0.0L,
half = 0.5L,
hfmax = HFMAX, /* half of the maximum number */
dbmin = DBMIN; /* double of the minimum (normal) number */
long double
remainderl(long double x, long double p) {
long double hp;
int sx;
if (isnanl(p))
return (x + p);
if (!finitel(x))
return (x - x);
p = fabsl(p);
if (p <= hfmax)
x = fmodl(x, p + p);
sx = signbitl(x);
x = fabsl(x);
if (p < dbmin) {
if (x + x > p) {
if (x == p)
x = zero;
else
x -= p; /* avoid x-x=-0 in RM mode */
if (x + x >= p)
x -= p;
}
} else {
hp = half * p;
if (x > hp) {
if (x == p)
x = zero;
else
x -= p; /* avoid x-x=-0 in RM mode */
if (x >= hp)
x -= p;
}
}
return (sx == 0 ? x : -x);
}