intel v10.1 compilers

Axel akoh... at
Fri Apr 25 18:45:58 UTC 2008

On Apr 25, 2:55 am, ilya <ily... at> wrote:
> 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.

v9.1 != v9.1

the magic is in the patchlevels. if the compiler is around
long enough and has been patched often enough, it will be
working as good as possible without major rewrites.

it is just annoying to have to go through the same circle
over and over again.


> 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> 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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