How to get GCC on par with ICC?

[Dmitry Mikushin]

Dear Paul,

The opinion you've mentioned is common in scientific community. However, in
more detail it often surfaces that the used set of GCC compiler options
simply does not correspond to that "fast" version of Intel. For instance,
when you do "-O3" for Intel it actually corresponds to (at least) "-O3
-ffast-math -march=native" of GCC. Omitting "-ffast-math" obviously
introduces significant performance gap.

Kind regards,
- Dmitry Mikushin | Applied Parallel Computing LLC |
https://parallel-computing.pro


2018-06-06 18:51 GMT+03:00 Paul Menzel <pmenzel+gcc.gnu.org@molgen.mpg.de>:

> Dear GCC folks,
>
>
> Some scientists in our organization still want to use the Intel compiler,
> as they say, it produces faster code, which is then executed on clusters.
> Some resources on the Web [1][2] confirm this. (I am aware, that it’s
> heavily dependent on the actual program.)
>
> My question is, is it realistic, that GCC could catch up and that the
> scientists will start to use it over Intel’s compiler? Or will Intel
> developers always have the lead, because they have secret documentation and
> direct contact with the processor designers?
>
> If it is realistic, how can we get there? Would first the program be
> written, and then the compiler be optimized for that? Or are just more GCC
> developers needed?
>
>
> Kind regards,
>
> Paul
>
>
> [1]: https://colfaxresearch.com/compiler-comparison/
> [2]: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.679
> .1280&rep=rep1&type=pdf
>
>