roundf.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 __roundf = roundf
#include "libm.h"
float
roundf(float x) {
union {
unsigned i;
float f;
} xx;
unsigned hx, sx, i;
xx.f = x;
hx = xx.i & ~0x80000000;
sx = xx.i & 0x80000000;
if (hx < 0x4b000000) { /* |x| < 2^23 */
if (hx < 0x3f800000) { /* |x| < 1 */
if (hx >= 0x3f000000)
return (sx ? -1.0F : 1.0F);
return (sx ? -0.0F : 0.0F);
}
/* round x at the integer bit */
i = 1 << (0x95 - (hx >> 23));
xx.i = (xx.i + i) & ~((i << 1) - 1);
return (xx.f);
} else if (hx < 0x7f800000) /* |x| is integral */
return (x);
else
#if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
return (hx > 0x7f800000 ? x * x : x + x);
#else
return (x + x);
#endif
}