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- /* Copyright (C) 1992, 1997 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 Library General Public License as
- published by the Free Software Foundation; either version 2 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
- Library General Public License for more details.
- You should have received a copy of the GNU Library General Public
- License along with the GNU C Library; see the file COPYING.LIB. If not,
- write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
- typedef struct {
- long quot;
- long rem;
- } ldiv_t;
- /* Return the `ldiv_t' representation of NUMER over DENOM. */
- ldiv_t
- ldiv (long int numer, long int denom)
- {
- ldiv_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;
- }
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