x4 difference between #to:do: and #timesRepeat - bug ?
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Hi,
I noticed quite a difference between the two method who "looks" the same to me. Is it normal ? I use a rc image (haven't tested in squeak). And it's the same on windows and linux. count := 0. [1 to: 10000000 do: [:i | count :=count + 1]] timeToRun." 677" count := 0. [10000000 timesRepeat: [count := count + 1]] timeToRun" 2571" If not normal, I'll open a issue. Thanks -- Cédrick _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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On Nov 13, 2009, at 9:51 AM, Cédrick Béler wrote: > Hi, > > I noticed quite a difference between the two method who "looks" the same to me. Is it normal ? > Normal. to:do: is lnlined (compiled as jumps in the bytecode), whereas timesRepeat: is a message send with a closure activation. Marcus fun is the difference between: (1 to : 10000) do: and 1 to: 10000 do: one is compiled to jumps, the other not and in addition creates a temp collection. Marcus > I use a rc image (haven't tested in squeak). And it's the same on windows and linux. > > count := 0. > [1 to: 10000000 do: [:i | count :=count + 1]] timeToRun." 677" > count := 0. > [10000000 timesRepeat: [count := count + 1]] timeToRun" 2571" > > If not normal, I'll open a issue. > > Thanks > > -- > Cédrick > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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Results for VisualAge (just FYI):
| count | count := 0. [1 to: 10000000 do: [:i | count :=count + 1]] timeToRun. "151702" | count | count := 0. [10000000 timesRepeat: [count := count + 1]] timeToRun. "139971" (results are in microseconds) So maybe there's a case for inlining #timesRepeat: (or making a clear comment that it is much slower in Pharo) Just my $0:02 -- Cheers, Peter
On Fri, Nov 13, 2009 at 9:59 AM, Marcus Denker <[hidden email]> wrote:
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Re: x4 difference between #to:do: and #timesRepeat - bug ?
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In reply to this post by Marcus Denker-3
There is also a difference between:
[self atEnd ifTrue: [^nil]. self next. true] whileTrue. and: [self atEnd ifTrue: [^nil] self next] repeat. Warning: it's quite easy to add Compiler inlining rules, a bit tougher to add corresponding Decompiler tricks. 2009/11/13 Marcus Denker <[hidden email]>: > > On Nov 13, 2009, at 9:51 AM, Cédrick Béler wrote: > >> Hi, >> >> I noticed quite a difference between the two method who "looks" the same to me. Is it normal ? >> > > Normal. to:do: is lnlined (compiled as jumps in the bytecode), whereas timesRepeat: is a message > send with a closure activation. > > Marcus > > fun is the difference between: > > (1 to : 10000) do: > and > 1 to: 10000 do: > > one is compiled to jumps, the other not and in addition creates a temp collection. > > Marcus > > > >> I use a rc image (haven't tested in squeak). And it's the same on windows and linux. >> >> count := 0. >> [1 to: 10000000 do: [:i | count :=count + 1]] timeToRun." 677" >> count := 0. >> [10000000 timesRepeat: [count := count + 1]] timeToRun" 2571" >> >> If not normal, I'll open a issue. >> >> Thanks >> >> -- >> Cédrick >> _______________________________________________ >> Pharo-project mailing list >> [hidden email] >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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No, please no more inilining hacks. :)
If someone wants to run everything at light speed - just code in C, but leave smalltalk honoring the message passing. And besides, these tricks won't make any difference when having good inlining JIT. In bytecode, they just add a complexity to compiler and headache to developers. 2009/11/13 Nicolas Cellier <[hidden email]>: > There is also a difference between: > > [self atEnd ifTrue: [^nil]. > self next. > true] whileTrue. > > and: > > [self atEnd ifTrue: [^nil] > self next] repeat. > > Warning: it's quite easy to add Compiler inlining rules, a bit tougher > to add corresponding Decompiler tricks. > > 2009/11/13 Marcus Denker <[hidden email]>: >> >> On Nov 13, 2009, at 9:51 AM, Cédrick Béler wrote: >> >>> Hi, >>> >>> I noticed quite a difference between the two method who "looks" the same to me. Is it normal ? >>> >> >> Normal. to:do: is lnlined (compiled as jumps in the bytecode), whereas timesRepeat: is a message >> send with a closure activation. >> >> Marcus >> >> fun is the difference between: >> >> (1 to : 10000) do: >> and >> 1 to: 10000 do: >> >> one is compiled to jumps, the other not and in addition creates a temp collection. >> >> Marcus >> >> >> >>> I use a rc image (haven't tested in squeak). And it's the same on windows and linux. >>> >>> count := 0. >>> [1 to: 10000000 do: [:i | count :=count + 1]] timeToRun." 677" >>> count := 0. >>> [10000000 timesRepeat: [count := count + 1]] timeToRun" 2571" >>> >>> If not normal, I'll open a issue. >>> >>> Thanks >>> >>> -- >>> Cédrick >>> _______________________________________________ >>> Pharo-project mailing list >>> [hidden email] >>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> >> >> _______________________________________________ >> Pharo-project mailing list >> [hidden email] >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> > > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > -- Best regards, Igor Stasenko AKA sig. _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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In reply to this post by Nicolas Cellier
Thanks all.
Interesting. I saw by using tallySends that: timesRepeat: This simulation took 6.0 seconds. **Tree** 1 SmallInteger(Integer)>>timesRepeat: **Leaves** 100001 UndefinedObject>>DoIt 1 SmallInteger(Integer)>>timesRepeat: 1 UndefinedObject>>DoIt to:do: This simulation took 3.0 seconds. **Tree** **Leaves** 1 UndefinedObject>>DoIt I guess this is one consequence of being inlined. This makes ask another questions: -how to know what's inlined, what method have suche properties (a comment would be cool, so if we had to choose...) ? -how to add Compiler inlining rules (as it's easy ;) ) ? -why not inlining timesRepeat: (as I guess we don't really change it often) ? Thanks. ps: the result is slow because I used a 5 year old (at least) computer :). I think I got a 10x difference in a 2 year one... 2009/11/13 Nicolas Cellier <[hidden email]> There is also a difference between: -- Cédrick _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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In reply to this post by Igor Stasenko
No, please no more inilining hacks. :) I agree but I asked beacause I'll make student use this method and wasn't sure of the explanation. Also, some asked me about the performance of Pharo/Smalltalk in general. I did this counter in C++ and Smalltalk. I get a 10x difference between C++ and Pharo, the inlined version, and therefore a 40x whith the other one. So does this number seems reasonnably true to you ? What would be the order of magnitude with a JIT ? TIA, Cédrick _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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2009/11/13 Cédrick Béler <[hidden email]>:
> > > >> No, please no more inilining hacks. :) >> If someone wants to run everything at light speed - just code in C, >> but leave smalltalk honoring the >> message passing. >> And besides, these tricks won't make any difference when having good >> inlining JIT. >> In bytecode, they just add a complexity to compiler and headache to >> developers. >> > > I agree but I asked beacause I'll make student use this method and wasn't > sure of the explanation. > > Also, some asked me about the performance of Pharo/Smalltalk in general. > > I did this counter in C++ and Smalltalk. > > I get a 10x difference between C++ and Pharo, the inlined version, and > therefore a 40x whith the other one. > > So does this number seems reasonnably true to you ? You are counting wrong numbers. Please count the time you have to spend to interpret closures in C++, and then using them run arbitrary code in the loop, then we will talk again when you done :) > What would be the order of magnitude with a JIT ? > > TIA, > > Cédrick > > > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > -- Best regards, Igor Stasenko AKA sig. _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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In reply to this post by cedreek
+1 for making an inlined version of #timesRepeat:
Sometimes speed matters, and for someone coming from an environment where it's faster than #to:do: it might not be so easy to detect where the unexpected time penalty came from. Unfortunately, I'm not sufficiently familiar with the Compiler/Decompiler to volunteer to do it myself :-p And to answer Cédrick's question, browsing senders of a method should tell you if it's inlined of not. In VA there are no senders of #timesRepeat: or #to:do, although both are used extensively. In case anyone is interested, here is the complete list of inlined methods in VA #== #~~ #and: #ifFalse: #ifFalse:ifTrue: #ifTrue: #ifTrue:ifFalse: #isNil #not #notNil #or: #timesRepeat: #to:do: #whileFalse: #whileTrue: How does it compare to Pharo? -- Cheers, Peter 2009/11/13 Cédrick Béler <[hidden email]> Thanks all. -- Cheers, Peter _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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> How does it compare to Pharo?
ifTrue: ifFalse: ifTrue:ifFalse: ifFalse:ifTrue: and: or: whileFalse: whileTrue: whileFalse whileTrue to:do: to:by:do: caseOf: caseOf:otherwise: ifNil: ifNotNil: ifNil:ifNotNil: ifNotNil:ifNil: See MessageNode for details. Lukas -- Lukas Renggli http://www.lukas-renggli.ch _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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In reply to this post by Peter Hugosson-Miller
On Nov 13, 2009, at 10:05 AM, Peter Hugosson-Miller wrote: > Results for VisualAge (just FYI): > > | count | > count := 0. > [1 to: 10000000 do: [:i | count :=count + 1]] timeToRun. "151702" > > | count | > count := 0. > [10000000 timesRepeat: [count := count + 1]] timeToRun. "139971" > > (results are in microseconds) > > So maybe there's a case for inlining #timesRepeat: (or making a clear comment that it is much slower in Pharo) > In general inlining is evil ;-) timesRepeat for the special case of being send to an int, detected statically... maybe I could be convinced of that. But in general, what would be much nicer would be to do it based on type-feedback information nicely hidden so nobody sees it. Marcus _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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In reply to this post by Igor Stasenko
>>>>> "Igor" == Igor Stasenko <[hidden email]> writes:
Igor> You are counting wrong numbers. Please count the time you have to spend Igor> to interpret closures in C++, and then using them run arbitrary code Igor> in the loop, Igor> then we will talk again when you done :) As we used to say in the C vs Perl debate: "Compared to Perl, C will give you the answer faster, but far later." :-) -- Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095 <[hidden email]> <URL:http://www.stonehenge.com/merlyn/> Smalltalk/Perl/Unix consulting, Technical writing, Comedy, etc. etc. See http://methodsandmessages.vox.com/ for Smalltalk and Seaside discussion _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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In reply to this post by Igor Stasenko
Igor Stasenko wrote:
> No, please no more inilining hacks. :) > If someone wants to run everything at light speed - just code in C, > but leave smalltalk honoring the > message passing. > And besides, these tricks won't make any difference when having good > inlining JIT. > In bytecode, they just add a complexity to compiler and headache to developers. +64 to banning bytecode compiler hacks and instead concentrate on producing an inlining JIT. -Martin _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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2009/11/13 Martin McClure <[hidden email]>:
> Igor Stasenko wrote: >> No, please no more inilining hacks. :) >> If someone wants to run everything at light speed - just code in C, >> but leave smalltalk honoring the >> message passing. >> And besides, these tricks won't make any difference when having good >> inlining JIT. >> In bytecode, they just add a complexity to compiler and headache to developers. > > +64 to banning bytecode compiler hacks and instead concentrate on > producing an inlining JIT. > > -Martin > The former is very easy, ugly and cheap. The later neither is easy nor cheap, and i doubt many of us will concentrate on this. Unless "concentrate" means "wait for Eliot's changes and pray". This can be reformulated as "don't bother on such details untill then". ;) Nicolas > > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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On Nov 13, 2009, at 7:24 PM, Nicolas Cellier wrote: > The former is very easy, ugly and cheap. yes. Ugly. And even wrong. I remember when I tried to explain a die-hard compiler researcher how the "optimizations" of #ifTrue: and friends work in Smalltalk... > The later neither is easy nor cheap, and i doubt many of us will > concentrate on this. > Unless "concentrate" means "wait for Eliot's changes and pray". :-) I did once do some work on Eliot's AOStA. I plan to work on resurrecting that, soon. Marcus -- Marcus Denker -- [hidden email] http://www.marcusdenker.de _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: x4 difference between #to:do: and #timesRepeat - bug ?
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In reply to this post by Martin McClure-2
On Fri, 2009-11-13 at 09:13 -0800, Martin McClure wrote:
> Igor Stasenko wrote: > > No, please no more inilining hacks. :) > > If someone wants to run everything at light speed - just code in C, > > but leave smalltalk honoring the > > message passing. > > And besides, these tricks won't make any difference when having good > > inlining JIT. > > In bytecode, they just add a complexity to compiler and headache to developers. > > +64 to banning bytecode compiler hacks and instead concentrate on > producing an inlining JIT. I'm working on inlining in Exupery now. The first three basic tests pass. Bryce _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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