[Mono-dev] [SPAM] Re: ToString() performace in Mono revisited

Wed Jan 2 11:55:29 EST 2008

If the null test is not desired, a nested class can be used instead and the
cctor trampoline will be patched later by the runtime.

On Jan 2, 2008 2:24 PM, Andreas Nahr <ClassDevelopment at a-softtech.com>
wrote:

> The array initialization should also be done lazily and not in the static
> constructor (should be removed completely because it drags in other static
> fields that need to be preinitialized, code compiled and so on).
> Especially the Hex support is IMHO completely off bounds. I (personally)
> rarely see hex output and making EVERYBODY pay for a hex speedup doesn't
> seem right. A simple
> if (array == null) Init ();
> will be enough. You will pay per-call, but it is relatively cheap.
> Otherwise a single
> Console.WriteLine (1.ToString());
> will get an EXTREMELY slow operation when you need to init a whole array
> just for a (potentially) single conversion.
>
> Greetings
> Andreas
>
> -----Ursprüngliche Nachricht-----
> Von: mono-devel-list-bounces at lists.ximian.com
> [mailto:mono-devel-list-bounces at lists.ximian.com] Im Auftrag von Eyal
> Alaluf
> Gesendet: Montag, 31. Dezember 2007 13:24
> An: Juraj Skripsky; Atsushi Eno
> Cc: Miguel de Icaza; mono-devel-list at lists.ximian.com
> Betreff: [SPAM] Re: [Mono-dev] ToString() performace in Mono revisited
>
> Hi, all.
>
> Thanks for the feedback. The amount of used memory is indeed not
> appropriate
> for small devices and is not economic enough.
>
> The 'DblExpTab' is essential in order for the double ToString to be
> efficient.
> As for the other two arrays they cache a simple arithmetic caclcualtion.
>
> I'll therefore eliminate the '_decHexLen' array and use
>  static readonly int[] _decHexDigits = new int [100]; I'll make DblRep
> into
> a struct and remove one member out of it (and slightly improve the
> double.ToString() perf along the way).
> This will change the allocation size to 100 * 4 + 2048 * (3 * 4) = ~25K.
>
> The performance impact is betweek 3-10% overall for simple ToString()
> depending on the hardware.
>
> Eyal.
>
> -----Original Message-----
> From: Juraj Skripsky [mailto:js at hotfeet.ch]
> Sent: 30 December 2007 19:34
> To: Atsushi Eno
> Cc: Eyal Alaluf; Miguel de Icaza; mono-devel-list at lists.ximian.com
> Subject: Re: [Mono-dev] ToString() performace in Mono revisited
>
> Hello,
>
> I think the following two arrays account for most of those 300KB:
>
> static readonly int[] _decHexDigits = new int [10000]; static readonly
> int[]
> _decHexLen = new int [0x10000];
>
> The first one consumes almost 40KB, the second one 256KB...
>
> The "DblExpTab" array uses 2048 * 4 = 8KB and its referenced DblRep
> objects
> 2048 * (8 + 4 * 4) = 48KB. This means a total of 56KB. Turning DblExbTab
> into a struct would reduce this to 2048 * (4 * 4) = 32KB.
>
> - Juraj
>
>
> On Mon, 2007-12-31 at 00:19 +0900, Atsushi Eno wrote:
> > Hello,
> >
> > Kazuki pointed out that the static initialization part of
> > NumberFormatter allocates 300KB. It is probably here:
> >
> >       public static readonly DblRep[] DblExpTab = new DblRep
> [ExponentMax + 1];
> >
> > It does not look good.
> >
> > Atsushi Eno
> >
> >
> > Eyal Alaluf wrote:
> > >
> > >
> > > With the attchments zipped to reduce size.
> > >
> > >
> > >
> > > * From: * mono-devel-list-bounces at lists.ximian.com
> > > [mailto:mono-devel-list-bounces at lists.ximian.com] *On Behalf Of
> *Eyal Alaluf
> > > *Sent:* 27 December 2007 17:28
> > > *To:* mono-devel-list at lists.ximian.com
> > > *Cc:* Miguel de Icaza
> > > *Subject:* [Mono-dev] ToString() performace in Mono revisited
> > >
> > >
> > >
> > > I got complaints that the font color within the table is white so
> this
> > > is a resent J
> > >
> > >
> > >
> > > Hi, all.
> > >
> > >
> > >
> > > Attached is a redesigned implementation of the NumberFormatter
> class.
> > > The patch includes a new algorithm for float and double ToString
> > > implementation that improves performance by a factor of 25(!) and
> upto
> > > 440(!!!). The patch includes further improvements to integer
> /ToString/
> > > as well as Andreas suggestion of avoiding calling
> > > /NumberFormatInfo.CurrentInfo/ in the case of integer types default
> > > /ToString()/ implementation.
> > >
> > > This patch should improve Mono's performance in important use cases
> such
> > > as web-services where primitive /ToString/ performance is an
> important
> > > factor.
> > >
> > >
> > >
> > > The following is a table showing the improvements for the different
> > > primitive types using the patch. All the results are in milliseconds
> and
> > > for a run of 10,000,000 iterations with warm-up of 10,000,000
> iterations
> > > as well.
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > Mono 1.2.6
> > >
> > >
> > >
> > > Patch
> > >
> > >
> > >
> > > Improvement
> > >
> > > 12345.ToString("G")
> > >
> > >
> > >
> > > 10079
> > >
> > >
> > >
> > > 7328
> > >
> > >
> > >
> > > 1.37
> > >
> > > 12345L.ToString("G")>
> > >
> > >
> > > 13203
> > >
> > >
> > >
> > > 7297
> > >
> > >
> > >
> > > 1.81
> > >
> > > 0.12345.ToString("G")
> > >
> > >
> > >
> > > 323750
> > >
> > >
> > >
> > > 13047
> > >
> > >
> > >
> > > 24.8(!)
> > >
> > > 1.2345E-200.ToString("G")
> > >
> > >
> > >
> > > 6376500
> > >
> > >
> > >
> > > 14328
> > >
> > >
> > >
> > > 445(!!!)
> > >
> > > 0.12345m.ToString("G")
> > >
> > >
> > >
> > > 51078
> > >
> > >
> > >
> > > 9875
> > >
> > >
> > >
> > > 5.2
> > >
> > > 12345.ToString()
> > >
> > >
> > >
> > > 12406/7781
> > >
> > >
> > >
> > > 5687
> > >
> > >
> > >
> > > 2.2/1.37
> > >
> > > 12345L.ToString()
> > >
> > > > >
> > >
> > > 281090
> > >
> > >
> > >
> > > 4006
> > >
> > >
> > >
> > > 3897
> > >
> > >
> > >
> > > 72.1(!!)
> > >
> > >
> > >
> > > 1.03
> > >
> > > 1.2345E-200.ToString("G")
> > >
> > >
> > >
> > > 5686000
> > >
> > >
> >12345.ToString("G")/!) and the second is after applying Andreas
> > > suggestion on top of Mono 1.2.6.
> > >
> > >
> > >
> > > The following are the results of the new algorithm compared to the
> old
> > > Mono algorithm and the .Net 2.0 native ToString performance, all
> three
> > > running on Microsoft .Net 2.0. The results show that the new code
> > > matches and even out-performs .Net /ToString/ implementation.
> > >
> > >
> > >
> > >
> > >
> > > Mono 1.2.6 algorithm
> > >
> > >
> > >
> > > Microsoft .Net 2.0
> > >
> > >
> > >
> > > New Patch algorithm
> > >
> > >
> > >
> > > Improvement over Mono 1.2.6
> > >
> > >
> > >
> > > Improvement over .Net 2.0
> > >
> > > 12345.ToString("G")
> > >
> > >
> > >
> > > 3700
> > >
> > >
> > >
> > > 2291
> > >
> > >
> > >
> > > 1827
> > >
> > >
> > >
> > > 2.0
> > >
> > >
> > >
> > > 1.25
> > >
> > > 12345L.ToString("G")
> > >
> > >
> > >
> > > 4559
> > >
> > >
> > >
> > > 2242
> > >
> > >
> > >
> > > 1919
> > >
> > >
> > >
> > > 2.38
> > >
> > >
> > >
> > > 1.17
> > >
> > > 0.12345.ToString("G")
> > >
> > >
> > >
> > > 281090
> > >
> > >
> > >
> > > 4006
> > >
> > >
> > >
> > > 3897
> > >
> > >
> > >
> > > 72.1(!!)
> > >
> > >
> > >
> > > 1.03
> > >
> > > 1.2345E-200.ToString("G")
> > >
> > >
> > >
> > > 5686000
> > >
> > >
> > >
> > > 4634
> > >
> > >
> > >
> > > 4613
> > >
> > >
> > >
> > > 1233(!!!)
> > >
> > >
> > >
> > > 1.00
> > >
> > > 0.12345m.ToString("G")
> > >
> > >
> > >
> > > 14562
> > >
> > >
> > >
> > > 3095
> > >
> > >
> > >
> > > 2294
> > >
> > >
> > >
> > > 6.3
> > >
> > >
> > >
> > > 1.35
> > >
> > > 12345.ToString()
> > >
> > >
> > >
> > > 3900/3002
> > >
> > >
> > >
> > > 2344
> > >
> > >
> > >
> > > 1313
> > >
> > >
> > >
> > > 3.0/2.3
> > >
> > >
> > >
> > > 1.79
> > >
> > > 12345L.ToString()
> > >
> > >
> > >
> > > 4684/3823
> > >
> > >
> > >
> > > 2245
> > >
> > >
> > >
> > > 1383
> > >
> > >
> > >
> > > 3.4/2.8
> > >
> > >
> > >
> > > 1.62
> > >
> > >
> > >
> > > It should be noted that the new code performance improvement are
> even
> > > more visible on top of .Net.
> > >
> > > It should also be noted that .Net runs the same algorithm 4 times
> faster
> > > then Mono. Since this code is self contained and almost completely
> > > algorithmic - I believe that it may serve as a good practical test
> case
> > > for improving Mono's JIT.
> > >
> > >
> > >
> > > The redesign is composed of three main changes
> > >
> > > *        An O(1) arithmetic transformation of a double (composed of
> > > sign, 2's exponent and mantissa bits) to sign, long and 10's
> exponent.
> > >
> > > *        Using a character array instead of a string buffer to
> construct
> > > the string result.
> > >
> > > *        Representing the number digits using hexadecimal values.
> That
> > > is /12345/ will be represented by /0x12345/.
> > >
> > >
> > >
> > > The patch passes Mono's unit tests on both 1.1 and 2.0.
> > >
> > >
> > >
> > > Please review and provide us with your feedback as soon as possible.
> > >
> > >
> > >
> > > Sasha, Roei & Eyal.
> > >
> > >
> > >
> ------------------------------------------------------------------------
> > >
> > > _______________________________________________
> > > Mono-devel-list mailing list
> > > Mono-devel-list at lists.ximian.com
> > > http://lists.ximian.com/mailman/listinfo/mono-devel-list
> >
> > _______________________________________________
> > Mono-devel-list mailing list
> > Mono-devel-list at lists.ximian.com
> > http://lists.ximian.com/mailman/listinfo/mono-devel-list
> >
>
> _______________________________________________
> Mono-devel-list mailing list
> Mono-devel-list at lists.ximian.com
> http://lists.ximian.com/mailman/listinfo/mono-devel-list
>
> _______________________________________________
> Mono-devel-list mailing list
> Mono-devel-list at lists.ximian.com
> http://lists.ximian.com/mailman/listinfo/mono-devel-list
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.ximian.com/pipermail/mono-devel-list/attachments/20080102/30befb7d/attachment.html 