CCL: Intel Fortran compiler
- From: "Perry E. Metzger"
<perry-,-piermont.com>
- Subject: CCL: Intel Fortran compiler
- Date: Thu, 10 Nov 2005 13:50:59 -0500
Sent to CCL by: "Perry E. Metzger" [perry::piermont.com]
"David F. Green dfgreen,+,ams.sunysb.edu"
<owner-chemistry/./ccl.net> writes:
> I should note, I'm generally a big fan of Free Software, and the Gnu
> compilers are impressive in the range of achitectures they support,
> but they simply do not produce particularly fast code, and sometimes
> that needs to be considered (this applies to C/C++ as well as to
> Fortran).
That depends. For some architectures, languages, target programs, and
versions of GCC, GCC works best. For others, it does not. It is very
dependent, as I said, on the architecture you're running on, the
language you're compiling, what code you're compiling, and (very very
important!) which version of gcc and which optimization flags you set.
I recommend benchmarking the code you're actually going to run on the
machines you'll run it on -- nothing beats an actual experiment in
cases like this. Especially if you're going to do a lot of
computation, taking a little bit of time and trying a few things
(including different settings of the optimization flags in your
compilers) pays off handsomely in the end.
Oh, and repeating that last bit one more time -- modern compilers have
LOTS of optimizations you can turn on and off. Reading the
documentation and experimenting with the flags is key. Never assume
that the same optimizations will produce the best results for all
programs you compile.
Perry