Why I love Python (warning: rambling)

[Jeremy Fincher]

Re: Why I love Python: More rambling...

Paul Rubin <http://phr.cx@NOSPAM.i nvalid> wrote in message news:<7xekwr6zs r.fsf@ruckus.br ouhaha.com>...[color=blue]
> Fernando Perez <fperez528@yaho o.com> writes:[color=green]
> > Full optimizations on, all debugging off. The bottleneck was not
> > the STL, but the Blitz++ array code. The problem is that blitz
> > template expressions are extremely complicated, and g++ is just not
> > up to the task. Tests made by a blitz developer with the SGI C++
> > compiler show far better scaling (with the rank of the tensors), but
> > I needed to run this on linux boxes using g++.[/color]
>
> What is that madness? Why not just write in C?[/color]

Blitz++ is even faster than FORTRAN for some numeric computations. I
doubt C could beat it.

Jeremy

[Juha Autero]

Re: Why I love Python: More rambling...

Fernando Perez <fperez528@yaho o.com> writes:
[color=blue]
> Tests made by a blitz developer with the SGI C++ compiler show far
> better scaling (with the rank of the tensors), but I needed to run
> this on linux boxes using g++.[/color]

What kind of Linux boxes? Intel has a C++ compiler for Linux that is
clamed to be better than GCC. It is not free and naturally only
available for x86, but if you can live with those terms, you could try
the free evaluation version to see if it helps.

--
Juha Autero

http://www.iki.fi/jautero/

Eschew obscurity!

[Fernando Perez]

Re: Why I love Python: More rambling...

Paul Rubin wrote:
[color=blue]
> Fernando Perez <fperez528@yaho o.com> writes:[color=green]
>> Full optimizations on, all debugging off. The bottleneck was not
>> the STL, but the Blitz++ array code. The problem is that blitz
>> template expressions are extremely complicated, and g++ is just not
>> up to the task. Tests made by a blitz developer with the SGI C++
>> compiler show far better scaling (with the rank of the tensors), but
>> I needed to run this on linux boxes using g++.[/color]
>
> What is that madness? Why not just write in C?[/color]

Have you seen how much fun it is to handle 6-index Numeric arrays in C? That's
why I used blitz++.

Best,

f

[Fernando Perez]

Re: Why I love Python: More rambling...

Fernando Perez wrote:
[color=blue]
> Juha Autero wrote:
>[color=green]
>> Fernando Perez <fperez528@yaho o.com> writes:
>>[color=darkred]
>>> Tests made by a blitz developer with the SGI C++ compiler show far
>>> better scaling (with the rank of the tensors), but I needed to run
>>> this on linux boxes using g++.[/color]
>>
>> What kind of Linux boxes? Intel has a C++ compiler for Linux that is
>> clamed to be better than GCC. It is not free and naturally only
>> available for x86, but if you can live with those terms, you could try
>> the free evaluation version to see if it helps.
>>[/color]
>
> I tested ifc on blitz++ code, and it's not significantly better than g++.[/color]

I mean: icc (ifc is their Fortran compiler, not the C/C++ one)

f

[Fernando Perez]

Re: Why I love Python: More rambling...

Juha Autero wrote:
[color=blue]
> Fernando Perez <fperez528@yaho o.com> writes:
>[color=green]
>> Tests made by a blitz developer with the SGI C++ compiler show far
>> better scaling (with the rank of the tensors), but I needed to run
>> this on linux boxes using g++.[/color]
>
> What kind of Linux boxes? Intel has a C++ compiler for Linux that is
> clamed to be better than GCC. It is not free and naturally only
> available for x86, but if you can live with those terms, you could try
> the free evaluation version to see if it helps.
>[/color]

I tested ifc on blitz++ code, and it's not significantly better than g++. The
issue is the expression templates used by blitz++, which ifc doesn't seem to
handle any better than g++. Granted, my testing was not exhaustive, but that
was the quick feeling I got.

Note that these issues creep up in blitz++ only when using their tensor index
objects at high rank, a somewhat dark corner case which obviously puts
compilers in a world of pain.

Best,

f