Re: [pooma-dev] Using gcc3.0 to compile POOMA

[Tarjei Knapstad]

On Thu, 2002-12-19 at 16:59, Richard Guenther wrote:
> On Thu, 19 Dec 2002, Richard Guenther wrote:
> 
> > Hi!
> >
> > I was just using gcc3.0 (CVS head) for POOMA and now noticed that
> > even at -O the NearestNeighbors test from the Field testsuite is
> > failing (works at -O0).
> 
> Same problem with current gcc3.2 CVS (-O2 -fomit-frame-pointer
> -march=athlon) :/
> 
Those nasties in 3.0 are apparently fixed in 3.2. Have you tried running
that test through Valgrind (http://devel-home.kde.org/~sewardj/) and see
if there's anything going bad in code execution? In my experience such
behaviour as described, is (at least in my case :) almost allways due to
bad code, not bad optimization on the compilers part.

> With gcc3.3 CVS and the same flags the test segfaults...
> 
Well, I wouldn't expect a development version to save the day :)

> Oh well ;)
> 
> > Also gcc3.0 contains loop optimizer bugs
> > that cause lots of regressions if -funroll-loops is used. So I
> > recommend people _not_ to use gcc3.0 to do anything with POOMA.
> >
> > I'll check whats up with gcc3.2, but that seems to be confused by
> > either my binutils or my libc version.
> >
> > Richard.

--
Tarjei

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