Re: Congrats on G95 LAPACK Success! (fwd)

> Hello all,
> 
> My name is Tony Awtrey and I've been working on a US Government
> sponsored study on using Open Source software to reduce life-cycle
> support costs of the simulators used for training. One of the points in
> the report is recommendations on porting older Fortran code used in many
> of the simulators to modern, open platforms.
> 
> The last time I researched this area in December of 2002, I tailored a
> set of 15 linear algebra benchmarks written in Fortran 77 to test the
> affect of Fortran to C conversions using 'f2c' (Result: Doubled the SLOC
> count, ruined maintainability and reduced performance 7%-10%). I also
> took the opportunity to test the Intel compilers against the GNU
> compilers to satisfy my own curiosity, but that really isn't going to be
> part of the report we're doing.
> 
> When I visited the G95 SourceForge site today I saw you all have been
> very busy since I visited last year. Congrats on the successful LAPACK
> compile tests! I have some other good news as well. My benchmarks were
> scripted and checked into cvs last year, so I checked them out again,
> added a G95 directory and ran your compiler against my tests...
> 
> I saved the relevant test data to a PDF here: 
> 
> http://www.awtrey.com/common/compiler-benchmarks.pdf
> 
> Bottom line, your brand new G95 compiler is 7% faster than G77 on the
> same code in the same machine! Here is the link to N.Tajima's FORTRAN
> benchmark that I used in my comparison:
> 
> http://serv.apphy.fukui-u.ac.jp/~tajima/bench/source_e.html
> 
> Thanks for the hard work and I hope our report can get additional
> funding directed to some of the open source development tool projects
> like yours and the GNU Compiler Collection as a whole.

  Thanks for your kind mail.  Although I suspect the difference with g77
may be that g77 is doing some very inefficient things as a opposed to g95
doing them efficiently.  The version of the backend I am using has a very
broken optimization pass, and I haven't seen much reason to update to a
new version.  (It'll eventually happen, though).

    Thanks again,
       Andy

Oh, it looks like the URL should be:

   http://www.awtrey.com/common/compiler-performance.pdf



-------------------------------------------------------
This SF.net email is sponsored by: VM Ware
With VMware you can run multiple operating systems on a single machine.
WITHOUT REBOOTING! Mix Linux / Windows / Novell virtual machines
at the same time. Free trial click here:http://www.vmware.com/wl/offer/358/0