mirror of
https://sourceware.org/git/glibc.git
synced 2025-12-24 17:51:17 +03:00
2005-12-13 Ulrich Drepper <drepper@redhat.com>
This commit is contained in:
86
stdlib/div.c
Normal file
86
stdlib/div.c
Normal file
@@ -0,0 +1,86 @@
|
||||
/* Copyright (C) 1992, 1997, 1999 Free Software Foundation, Inc.
|
||||
This file is part of the GNU C Library.
|
||||
|
||||
The GNU C Library is free software; you can redistribute it and/or
|
||||
modify it under the terms of the GNU Lesser General Public
|
||||
License as published by the Free Software Foundation; either
|
||||
version 2.1 of the License, or (at your option) any later version.
|
||||
|
||||
The GNU C Library is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with the GNU C Library; if not, write to the Free
|
||||
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
||||
02111-1307 USA. */
|
||||
|
||||
/*
|
||||
* Copyright (c) 1990 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.
|
||||
* 4. 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 <stdlib.h>
|
||||
|
||||
/* Return the `div_t' representation of NUMER over DENOM. */
|
||||
div_t
|
||||
div (numer, denom)
|
||||
int numer, denom;
|
||||
{
|
||||
div_t result;
|
||||
|
||||
result.quot = numer / denom;
|
||||
result.rem = numer % denom;
|
||||
|
||||
/* The ANSI standard says that |QUOT| <= |NUMER / DENOM|, where
|
||||
NUMER / DENOM is to be computed in infinite precision. In
|
||||
other words, we should always truncate the quotient towards
|
||||
zero, never -infinity. Machine division and remainer may
|
||||
work either way when one or both of NUMER or DENOM is
|
||||
negative. If only one is negative and QUOT has been
|
||||
truncated towards -infinity, REM will have the same sign as
|
||||
DENOM and the opposite sign of NUMER; if both are negative
|
||||
and QUOT has been truncated towards -infinity, REM will be
|
||||
positive (will have the opposite sign of NUMER). These are
|
||||
considered `wrong'. If both are NUM and DENOM are positive,
|
||||
RESULT will always be positive. This all boils down to: if
|
||||
NUMER >= 0, but REM < 0, we got the wrong answer. In that
|
||||
case, to get the right answer, add 1 to QUOT and subtract
|
||||
DENOM from REM. */
|
||||
|
||||
if (numer >= 0 && result.rem < 0)
|
||||
{
|
||||
++result.quot;
|
||||
result.rem -= denom;
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
Reference in New Issue
Block a user