/*      $NetBSD: div.c,v 1.8 2012/06/25 22:32:45 abs Exp $      */

/*
* Copyright (c) 1990, 1993
*      The Regents of the University of California.  All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)div.c       8.1 (Berkeley) 6/4/93";
#else
__RCSID("$NetBSD: div.c,v 1.8 2012/06/25 22:32:45 abs Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

#include <stdlib.h>             /* div_t */

div_t
div(int num, int denom)
{
       div_t r;

       r.quot = num / denom;
       r.rem = num % denom;
       /*
        * The ANSI standard says that |r.quot| <= |n/d|, where
        * n/d is to be computed in infinite precision.  In other
        * words, we should always truncate the quotient towards
        * 0, never -infinity.
        *
        * Machine division and remainer may work either way when
        * one or both of n or d is negative.  If only one is
        * negative and r.quot has been truncated towards -inf,
        * r.rem will have the same sign as denom and the opposite
        * sign of num; if both are negative and r.quot has been
        * truncated towards -inf, r.rem will be positive (will
        * have the opposite sign of num).  These are considered
        * `wrong'.
        *
        * If both are num and denom are positive, r will always
        * be positive.
        *
        * This all boils down to:
        *      if num >= 0, but r.rem < 0, we got the wrong answer.
        * In that case, to get the right answer, add 1 to r.quot and
        * subtract denom from r.rem.
        */
       if (num >= 0 && r.rem < 0) {
               r.quot++;
               r.rem -= denom;
       }
       return (r);
}