http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48789
Ramana Radhakrishnan <ramana at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |ramana at gcc dot gnu.org
--- Comment #4 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> 2011-07-27
16:40:09 UTC ---
There are a number of problems and not all of them are related to the backend.
- ldm / stm aren't really first class citizens as far as GCC is concerned .
There is no way today of getting the register allocator to forcefully use
increasing addresses as a metric of choosing where to do what.
- I suspect the performance issues you are seeing are with the number of spills
and fills that are being generated in this case. If you tried -fsched-pressure
life becomes much better and in fact the amount of stack space used is 0 . I
haven't run any benchmarks to see if in this particular case you get better
performance .
