This is the mail archive of the
gcc-help@gcc.gnu.org
mailing list for the GCC project.
RE: Linux c++ opmization--- linux runs at half the speed of windows?
- From: "Atwood, Robert C" <r dot atwood at imperial dot ac dot uk>
- To: "Shane R" <crazguy22 at hotmail dot com>
- Cc: <gcc-help at gcc dot gnu dot org>
- Date: Thu, 8 Mar 2007 15:01:05 -0000
- Subject: RE: Linux c++ opmization--- linux runs at half the speed of windows?
> On another note does anyone have any experience with the
> Intel drop in
> replacement for GCC?
>
> Thanks in advance for any help,
>
> Shane
Yes but not very good experience, perhaps mediocre. I had very annoying
problems with a bug in the intel optimizer .. It seemed like my code was
way faster, until I noticed that it was not giving the correct results,
and observed that the optimizer was reducing precision when it should
not. There was also some case where it kept optimizing a=b; b=c; into
effectively a=b=c; not the same thing at all!
THe recommended workaround was to reduce the optimization level , at
which point it was no longer faster and I had lost my own time faffing
about with it. Since then that bug was supposedly fixed in later
release, but they lost my confidence and convinced me further that free
software is the way to go, not only for political, but also practical
reasons.