common/m9x/lroundf.c

	lroundf.c revision 25c28e83beb90e7c80452a7c818c5e6f73a07dc8
/*
 * 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.
 */

#if defined(ELFOBJ)
#pragma weak lroundf = __lroundf
#endif

#include <sys/isa_defs.h>   /* _ILP32 */
#include "libm.h"

#if defined(_ILP32)
long
lroundf(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 ? -1L : 1L);
            return (0L);
        }

        /* round x at the integer bit */
        i = 1 << (0x95 - (hx >> 23));
        xx.i = (xx.i + i) & ~((i << 1) - 1);
        return ((long) xx.f);
    }

    /* now x is nan, inf, or integral */
    return ((long) x);
}
#else
#error Unsupported architecture
#endif  /* defined(_ILP32) */