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Re: profiler and/or debugger, loops vs vectorization
From: |
David Bateman |
Subject: |
Re: profiler and/or debugger, loops vs vectorization |
Date: |
Sat, 01 Jul 2006 18:19:42 +0200 |
User-agent: |
Mozilla Thunderbird 1.0.6-7.6.20060mdk (X11/20050322) |
David Grohmann wrote:
> So I have some code that runs in matlab (on a P3 500 mhz 512 MB ram
> windows box) about 133 times faster (33 minutes to complete something
> instead of 15 seconds) than it does in octave( on a 4 processor 3.6 ghz
> xeon machine with an ungodly amount of ram linux box). my guess is that
> it is the use of loops and not vectorization.
>
> Is such a large performance hit likely caused by loops vs vectorization
> or might there be another explanation besides that?
>
> I've searched online and haven't found anything to profile m files with,
> other than in matlab. I have profiled it in matlab and sure enough it
> does run the lines in the loops many (hundreds of thousands of times)
> times but only one of the loops actually takes up a lot of run time.
> This would probably be a good candidate for vectorizing. I suspect.
>
> So is there anything out there for profiling or stepping through code in
> an m file in octave?
>
> I know I haven't posted the offending code, that is because I currently
> don't have the authorization to do that. So my general question is how
> do people profile their code and what not. I'm not asking you to fix my
> code for me.
>
> Thank you for any help you provide,
>
My guess is that you are running a cygwin binary version of octave.
There is a major bug in the setjmp/longjmp exception handler of g++ for
versions later than 3.2 that causes major pain to octave. As far as I
know this bug in cygwin as not yet been addressed. The result is
sssllloooowwww code..
D.
- Re: profiler and/or debugger, loops vs vectorization, John W. Eaton, 2006/07/01
- Re: profiler and/or debugger, loops vs vectorization,
David Bateman <=
- Re: profiler and/or debugger, loops vs vectorization, David Grohmann, 2006/07/05
- Re: profiler and/or debugger, loops vs vectorization, David Bateman, 2006/07/05
- Re: profiler and/or debugger, loops vs vectorization, John W. Eaton, 2006/07/05
- Re: profiler and/or debugger, loops vs vectorization, Andy Adler, 2006/07/05
- Re: profiler and/or debugger, loops vs vectorization, David Grohmann, 2006/07/05
- Message not available
- Re: profiler and/or debugger, loops vs vectorization, Jordi Gutierrez Hermoso, 2006/07/05
- Re: loops vs vectorization, Robert A.Macy, 2006/07/05
- Re: loops vs vectorization, Rafael Almeida, 2006/07/05
- Re: loops vs vectorization, Robert A.Macy, 2006/07/05
- Re: loops vs vectorization, Ozzy Lash, 2006/07/05