port/gen/lmath.c

	lmath.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*  Copyright (c) 1988 AT&T */
/*    All Rights Reserved   */


/*
 * This set of routines used to be implemented mostly in assembler.
 *
 * Since the purpose they have is now rather vestigial, and 64-bit
 * machines can do operations on 64-bit quantities pretty efficiently,
 * a C implementation seems quite adequate and much more maintainable.
 */

#pragma weak ladd = _ladd
#pragma weak lsub = _lsub
#pragma weak lshiftl = _lshiftl
#pragma weak lsign = _lsign
#pragma weak lmul = _lmul

#include "synonyms.h"
#include <sys/types.h>
#include <sys/dl.h>

typedef union {
    long    xword;
    dl_t    dl;
} dlx_t;

dl_t
ladd(dl_t lop, dl_t rop)
{
    dlx_t r;
    /* LINTED pointer cast may result in improper alignment */
    r.xword = *(long *)&lop + *(long *)&rop;
    return (r.dl);
}

dl_t
lshiftl(dl_t op, int cnt)
{
    dlx_t r;
    if (cnt < 0)
        /* LINTED pointer cast may result in improper alignment */
        r.xword = (long)(*(ulong_t *)&op >> (-cnt));
    else
        /* LINTED pointer cast may result in improper alignment */
        r.xword = *(long *)&op << cnt;
    return (r.dl);
}

int
lsign(dl_t op)
{
    /* LINTED pointer cast may result in improper alignment */
    return ((*(long *)&op) >> 63);
}

dl_t
lsub(dl_t lop, dl_t rop)
{
    dlx_t r;
    /* LINTED pointer cast may result in improper alignment */
    r.xword = *(long *)&lop - *(long *)&rop;
    return (r.dl);
}

dl_t
lmul(dl_t lop, dl_t rop)
{
    dlx_t r;
    /* LINTED pointer cast may result in improper alignment */
    r.xword = *(long *)&lop * *(long *)&rop;
    return (r.dl);
}