Tree-ssa status with POOMA

[Jan Hubicka]

> Hi!
> 
> I promised to give some updates on tree-ssa and POOMA.  Tree-ssa is
> currently failing three regression tests that 3.4 succeeds in.  One
> is a clear miscompilation resulting in wrong results, two look like the
> same bug causing a SIGSEGV.  As usual the testcases would be incredibly
> large and hard to debug, so this is mainly a heads-up (though 3.3.3 won't
> be any better here).
> 
> For my real-world application I'm quite happy with tree-ssa:
> 
> -O2 -funroll-loops -ffast-math -march=athlon -fno-exceptions
> 
> 		memory	compile-time	run-time	stripped static size
> tree-ssa	450MB	3m57s		46s		1729680
> gcc3.4		530MB	3m16s		44s		1734596
> 
> compile times are slightly in favor of 3.4, but it was compiled with a
> profiledbootstrap (with a usual bootstrap I remember about 3m40s compile
> time).  Runtime is also slightly in favor of 3.4, but memory usage and
> binary size are really fine.  Results are identical for both 3.4 and
> tree-ssa runs as far as correctness is concerned.

Out of curiosity, if you use -Winline, how does the amount of inline
failures compare?  I wonder how much the memory differences can be
attributed to simple fact that tree-ssa inline less because functions
looks bigger after gimplified.  That would explain the runtime and code
size difference too.
It would also suggest that the inline limits are still bit too up for
3.4.  How did you measured the memory usage?

Honza
> 
> Richard.
> 
> --
> Richard Guenther <richard dot guenther at uni-tuebingen dot de>
> WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/