ldexp.c revision ddc0e0b53c661f6e439e3b7072b3ef353eadb4af
/*
* 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 __ldexp = ldexp
#include "libm.h"
#include <errno.h>
double
ldexp(double x, int n) {
int *px = (int *) &x, ix = px[HIWORD] & ~0x80000000;
if (ix >= 0x7ff00000 || (px[LOWORD] | ix) == 0)
#if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
return (ix >= 0x7ff80000 ? x : x + x);
/* assumes sparc-like QNaN */
#else
return (x + x);
#endif
x = scalbn(x, n);
ix = px[HIWORD] & ~0x80000000;
/*
* SVID3 requires both overflow and underflow cases to set errno
* XPG3/XPG4/XPG4.2/SUSv2 requires overflow to set errno
*/
if (ix >= 0x7ff00000 || (px[LOWORD] | ix) == 0)
errno = ERANGE;
return (x);
}