Re: For loop benchmarks between Octave versions

[Julien Bect]

Le 25/06/2014 11:40, Julien Bect a écrit :
> Le 25/06/2014 09:54, Daniel J Sebald a écrit :
> > > Any idea about where to look next ?
> >
> > I know little about the parser, but I looked around a bit to see if I 
> > could get a feel for things to answer the question "where to look".  
> > I think it might be better to just work from the development version 
> > and look for ways to optimize code.  If you have a working profiler, 
> > that might indicate where most of the time is being spent so you can 
> > start looking there. 
>
> I don't have a working profiler, and unfortunately no experience on 
> how to set up one.
>
> Based on this (rather old) thread :
>
> http://octave.1599824.n4.nabble.com/profiling-Octave-td1634535.html
>
> it doesn't seem completely trivial.
>
> Is there a place where I can find step-by-step instructions on how to 
> build Octave for profiling ?

I have tried (and failed) to build Octave 3.8.2-RC1 for profiling with 
gprof. I need some help here...

I have compiled with the following (Ubuntu 13.04 / i686-linux-gnu / gcc 
version 4.7.3) :

    ./bootstrap

    ./configure --enable-static --disable-dl --disable-shared \
--disable-docs CFLAGS="-O2 -pg" CXXFLAGS="-O2 -pg" \
        LDFLAGS="-pg" FFLAGS="-O2 -pg"

    make

Octave fails to start without the GUI :

    $ ~/3.8.2-RC1-prof/run-octave --no-gui

Expiration de la minuterie durant l'établissement du profile
    # a.k.a. "Profiling timer expired" in english, I think

If I start Octave with the GUI it "works", but the resulting gmon.out 
seems useless :

    $ ~/3.8.2-RC1-prof/run-octave --force-gui --eval "result = perf1 ()"

    # Octave crashes on exit (but gmon.out is created)
    #    panic: Abandon -- stopping myself...
    #    attempting to save variables to 'octave-workspace'...
    #    panic: attempted clean up apparently failed -- aborting...
    #    octave exited with signal 6

    $ cd ~/3.8.2-RC1-prof
    $ gprof src/octave gmon.out

    Flat profile:

    Each sample counts as 0.01 seconds.
     no time accumulated

      %   cumulative   self              self total
     time   seconds   seconds    calls  Ts/call  Ts/call name
      0.00      0.00     0.00        1     0.00     0.00 
_GLOBAL__sub_I__Z17display_availableRSs


Wouldn't it be possible to have a --gprof option for configure that sets 
all the other options right ?