[Mono-dev] ToString() performace in Mono

Andreas Nahr ClassDevelopment at A-SoftTech.com
Mon Nov 26 13:20:36 EST 2007

The following code (add to NumberFormatter) and redirect the ToStrings
improves performance even more:

Old Formatter: 1266
New Formatter with negative number: 953
New Formatter with positive number: 750

Tested on Windows XP, Mono 1.2.5

		internal static string FormatInteger (ref NumberStore ns)
			// Add one additional char for default sign, one for
potential 0-padding
			StringBuilder cb = new StringBuilder
(ns.IntegerDigits + 2);

			if (!ns.Positive && !ns.CheckZeroOnlyInteger ())

			ns.AppendIntegerString (ns.IntegerDigits > 0 ?
ns.IntegerDigits : 1, cb);
			return cb.ToString ();

The additional performance in Comparison to Kazuki Oikawa suggestion is
mainly gained through not retrieving NumberFormatInfo.CurrentInfo in cases
where it's not needed (and other small things like ref struct).
NumberFormatInfo.CurrentInfo should be optimized anyways. It just shouldn't
be as slow as it is as it is likely used in other situations, too.


-----Ursprüngliche Nachricht-----
Von: mono-devel-list-bounces at lists.ximian.com
[mailto:mono-devel-list-bounces at lists.ximian.com] Im Auftrag von Kazuki
Gesendet: Samstag, 24. November 2007 06:02
An: pablosantosluac
Cc: mono-devel-list at lists.ximian.com
Betreff: Re: [Mono-dev] ToString() performace in Mono


This patch improves ToString performance (30% faster).

Running on Opteron 270 (2GHz), Gentoo Linux 2007.0 x86_64 $ mono hoge.exe
val is 5999999 and time 7008 (before) $ mono hoge.exe val is 5999999 and
time 5078 (after)

Current code is use "G" format but this equals "D" format when precision is
not defined and value is integer.

Best regards.

Kazuki Oikawa

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