--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/genericopenlibs/openenvcore/libc/src/stdtime/difftime.c	Fri Jun 04 16:20:51 2010 +0100
@@ -0,0 +1,101 @@
+/*
+* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description: 
+*
+*/
+
+
+#include <sys/cdefs.h>
+#ifndef lint
+#ifndef NOID
+static char	elsieid[] __unused = "@(#)difftime.c	7.9";
+#endif /* !defined NOID */
+#endif /* !defined lint */
+__FBSDID("$FreeBSD: src/lib/libc/stdtime/difftime.c,v 1.8 2004/06/14 10:31:52 stefanf Exp $");
+
+/*LINTLIBRARY*/
+
+#include "namespace.h"
+#include "private.h"
+#include "un-namespace.h"
+
+/*
+** Algorithm courtesy Paul Eggert (eggert@twinsun.com).
+*/
+
+#ifdef HAVE_LONG_DOUBLE
+#define long_double	long double
+#endif /* defined HAVE_LONG_DOUBLE */
+#ifndef HAVE_LONG_DOUBLE
+#define long_double	double
+#endif /* !defined HAVE_LONG_DOUBLE */
+
+EXPORT_C
+double
+difftime(time1, time0)
+const time_t	time1;
+const time_t	time0;
+{
+	time_t	delta;
+	time_t	hibit;
+
+	{
+		time_t		tt;
+		double		d;
+		long_double	ld;
+
+		if (sizeof tt < sizeof d)
+			return (double) time1 - (double) time0;
+		if (sizeof tt < sizeof ld)
+			return (long_double) time1 - (long_double) time0;
+	}
+	if (time1 < time0)
+		return -difftime(time0, time1);
+	/*
+	** As much as possible, avoid loss of precision
+	** by computing the difference before converting to double.
+	*/
+	delta = time1 - time0;
+	if (delta >= 0)
+		return delta;
+	/*
+	** Repair delta overflow.
+	*/
+	hibit = (~ (time_t) 0) << (TYPE_BIT(time_t) - 1);
+	/*
+	** The following expression rounds twice, which means
+	** the result may not be the closest to the true answer.
+	** For example, suppose time_t is 64-bit signed int,
+	** long_double is IEEE 754 double with default rounding,
+	** time1 = 9223372036854775807 and time0 = -1536.
+	** Then the true difference is 9223372036854777343,
+	** which rounds to 9223372036854777856
+	** with a total error of 513.
+	** But delta overflows to -9223372036854774273,
+	** which rounds to -9223372036854774784, and correcting
+	** this by subtracting 2 * (long_double) hibit
+	** (i.e. by adding 2**64 = 18446744073709551616)
+	** yields 9223372036854776832, which
+	** rounds to 9223372036854775808
+	** with a total error of 1535 instead.
+	** This problem occurs only with very large differences.
+	** It's too painful to fix this portably.
+	** We are not alone in this problem;
+	** some C compilers round twice when converting
+	** large unsigned types to small floating types,
+	** so if time_t is unsigned the "return delta" above
+	** has the same double-rounding problem with those compilers.
+	*/
+	return delta - 2 * (long_double) hibit;
+}