diff options
Diffstat (limited to 'sysdeps/generic/lldiv.c')
-rw-r--r-- | sysdeps/generic/lldiv.c | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/sysdeps/generic/lldiv.c b/sysdeps/generic/lldiv.c new file mode 100644 index 0000000000..1659e0f837 --- /dev/null +++ b/sysdeps/generic/lldiv.c @@ -0,0 +1,57 @@ +/* `long long int' divison with remainder. +Copyright (C) 1992, 1996 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. */ + +#include <stdlib.h> + + +/* Return the `lldiv_t' representation of NUMER over DENOM. */ +lldiv_t +lldiv (numer, denom) + long long int numer; + long long int denom; +{ + lldiv_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; +} |