summaryrefslogtreecommitdiffstats
path: root/lib/ldiv.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/ldiv.c')
-rw-r--r--lib/ldiv.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/lib/ldiv.c b/lib/ldiv.c
new file mode 100644
index 0000000000..5d231a2a65
--- /dev/null
+++ b/lib/ldiv.c
@@ -0,0 +1,55 @@
+/* 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;
+}
OpenPOWER on IntegriCloud