intel v10.1 compilers

ilya ily... at gmail.com
Fri Apr 25 08:55:39 CEST 2008


Hi !!!

I remember that when I tried to compile the whole cp2k with intel 9.1
on opteron I've got a lot of strange problems with seg faults etc.

Upgrading to 10.1 allowed me to successfully compile the thing.

In both cases of course I turned off Intel specific optimizations (no -
xSomething key; -O2).

It's interesting whether intel provides some sort of 'official'
support for nonintel x86 and x86_64 cpus
(and for intel cpus too :-)  ).

I also know that they replaced vectorization module in intel 10.1
(compared to 9.1). And in some cases this new vectorizer generates
code that runs several times slower (i've made a simple synthetic test
-- mandelbrot fractal generator). Some people on their developer forum
also reported such performance problems on new compilers.
Of course for real-problem code I think there is no such degradation.
But anyway...

So it's interesting what are they doing there in intel???

PS To tell the truth, their performance suites are rather handy and
FREE for linux. So it's very unpleasant to see such problems.
Unfortunately...


On Apr 24, 8:58 pm, Axel <akoh... at gmail.com> wrote:
> hi everybody,
>
> it may perhaps of interest to several people here, that after
> extensive
> testing, i have to come to the conclusion that the current intel
> v10.1
> compilers invariably miscompile some modules of cp2k on all platforms
> (but different ones on each) and regardless of the optimization level
> and
> patchlevel of the compiler. most problems show only up when running
> in parallel.
>
> in all the problematic cases, using a g95 or intel v9.1
> compiled executable (with -O2 optimization only) was
> fixing the problems.
>
> cheers,
>      axel.


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