/*
* 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 modf = __modf
#pragma weak _modf = __modf
/*
* modf(x, iptr) decomposes x into an integral part and a fractional
* part both having the same sign as x. It stores the integral part
* in *iptr and returns the fractional part.
*
* If x is infinite, modf sets *iptr to x and returns copysign(0.0,x).
* If x is NaN, modf sets *iptr to x and returns x.
*
* If x is a signaling NaN, this code does not attempt to raise the
* invalid operation exception.
*/
#include "libm.h"
double
__modf(double x, double *iptr) {
union {
unsigned i[2];
double d;
} xx, yy;
unsigned hx, s;
xx.d = x;
hx = xx.i[HIWORD] & ~0x80000000;
if (hx >= 0x43300000) { /* x is NaN, infinite, or integral */
*iptr = x;
if (hx < 0x7ff00000 || (hx == 0x7ff00000 &&
xx.i[LOWORD] == 0)) {
xx.i[HIWORD] &= 0x80000000;
xx.i[LOWORD] = 0;
}
return (xx.d);
}
if (hx < 0x3ff00000) { /* |x| < 1 */
xx.i[HIWORD] &= 0x80000000;
xx.i[LOWORD] = 0;
*iptr = xx.d;
return (x);
}
/* split x at the binary point */
s = xx.i[HIWORD] & 0x80000000;
if (hx < 0x41400000) {
yy.i[HIWORD] = xx.i[HIWORD] & ~((1 << (0x413 - (hx >> 20))) -
1);
yy.i[LOWORD] = 0;
} else {
yy.i[HIWORD] = xx.i[HIWORD];
yy.i[LOWORD] = xx.i[LOWORD] & ~((1 << (0x433 - (hx >> 20))) -
1);
}
*iptr = yy.d;
xx.d -= yy.d;
xx.i[HIWORD] = (xx.i[HIWORD] & ~0x80000000) | s;
/* keep sign of x */
return (xx.d);
}