root/usr/src/lib/libm/common/R/log1pf.c
/*
 * 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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma weak __log1pf = log1pf

#include "libm.h"

static const float zero = 0.0f;

float
log1pf(float x) {
        int     ix;

        ix = *(int *)&x;
        if (ix >= 0x7f800000) {
                /* x is +inf or nan */
                return (x * x);
        }
        if (ix < 0) {
                ix &= ~0x80000000;
                if (ix == 0x3f800000) /* x is -1 */
                        return (x / zero);
                if (ix > 0x3f800000) /* x is < -1 or nan */
                        return ((x * zero) / zero);
        }
        return ((float)log1p((double)x));
}