Add missing imaxdiv and lldiv needed for SuSv3. Adjust ldiv to

match glibc's quotient truncation behavior.

1 files changed, 54 insertions, 24 deletions

diff --git a/libc/stdlib/ldiv.c b/libc/stdlib/ldiv.c
index 230b6a944..c66470fb2 100644
--- a/libc/stdlib/ldiv.c
+++ b/libc/stdlib/ldiv.c
@@ -1,32 +1,62 @@
-/* vi: set sw=4 ts=4: */
-/* ldiv for uClibc
- *
- * Copyright (C) 2000 by Lineo, inc. and Erik Andersen
- * Copyright (C) 2000,2001 by Erik Andersen <andersen@uclibc.org>
- * Written by Erik Andersen <andersen@uclibc.org>
- *
- * This program 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.
- *
- * This program 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 this program; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
 
+/* 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 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.  */
+
+#include <features.h>
 #include <stdlib.h>
 
-ldiv_t ldiv(long numer, long denom)
+
+/* 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 - (result.quot * denom);
-    return(result);
+    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;
 }
 
+#if __WORDSIZE == 64
+#undef imaxdiv
+weak_alias (ldiv, imaxdiv);
+#endif
+