------- Comment #9 from hubicka at gcc dot gnu dot org 2005-11-03 20:06 -------
For reload CSE there is --param max-cselib-memory-locations=10
that cuts it's time to 1%, overall.
Since this testcase is sort of designed to excercise the worst case behaviour,
I think it is not too bad...
alias analysis has:
/* Maximum length of pbi->mem_set_list before we start dropping
new elements on the floor. */
#define MAX_MEM_SET_LIST_LEN 100
perhaps unifying all these lists would make sense. Would that be applicable
for 4.1? (Ie I would have to pick some common value, like 300 - cselib defaults
to 500)
CSE has:
/* If we have processed 1,000 insns, flush the hash table to
avoid extreme quadratic behavior. We must not include NOTEs
in the count since there may be more of them when generating
debugging information. If we clear the table at different
times, code generated with -g -O might be different than code
generated with -O but not -g.
??? This is a real kludge and needs to be done some other way.
Perhaps for 2.9. */
I am not sure if I can fit memory specific limit in this (it would be nice to
simply throw away old entries rather than flushing it all), or we can just keep
it.
None of these algorithms would grow ad infimum and manifest worse behaviour
than in this testcase, so I would not consider it P2
Honza
--
hubicka at gcc dot gnu dot org changed:
What |Removed |Added
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CC| |hubicka at gcc dot gnu dot
| |org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23490
