[patch] Lno branch merge part 12 -- induction variable optimizations
Mon Aug 30 19:42:00 GMT 2004
> >So far I've "solved" those problems by punting and waiting for
> >DCE to clean things up. That's been pretty consistent with the
> >design decisions we've made regarding isolation of optimizations.
> >Is there some reason why that model is not appropriate? For example,
> >does leaving these dead statements in the IL until the next DCE
> >pass actually inhibit optimizations or cause correctness issues?
> >[ While I sometimes lean towards having dead code automatically go
> > away when the last use of the statement's LHS goes away, I'm
> > very leery of going that direction because of our past experiences
> > of doing this kind of thing at the RTL level. ]
> In my loops to memset optimization, I do punt almost everything to
> DCE except for the memory access which I transform to the memset
> call. So I remove the memory store as it is not removed by DCE.
> Also we don't remove loops on later passes which hurt performance.
> Can anyone say when we are going to remove empty loops even without
after my patch to do it is reviewed? I posted it sometimes in the
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