about summary refs log tree commit diff
path: root/sysdeps/generic/lldiv.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/generic/lldiv.c')
-rw-r--r--sysdeps/generic/lldiv.c57
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;
+}