f14fb60209
* Updating common/lib * Updating lib/csu * Updating lib/libc * Updating libexec/ld.elf_so * Corrected test on __minix in featuretest to actually follow the meaning of the comment. * Cleaned up _REENTRANT-related defintions. * Disabled -D_REENTRANT for libfetch * Removing some unneeded __NBSD_LIBC defines and tests Change-Id: Ic1394baef74d11b9f86b312f5ff4bbc3cbf72ce2
82 lines
3.0 KiB
C
82 lines
3.0 KiB
C
/* $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);
|
|
}
|