On Tue, 4 Sep 2012, Steven Bosscher wrote: > On Tue, Sep 4, 2012 at 3:19 PM, Richard Guenther <rguent...@suse.de> wrote: > > > > Currently computa_avail consumes an unreasonable amount of memory > > in the FRE case for PR46590. The following patch makes some > > obvious adjustments but does not cure the underlying issue. > > I don't think there's any way to cure the underlying issue, it's just > the result of having SSA form that so many values are available. You > can improve the representation of the sets (e.g. something similar to > the views of the tree-ssa-live machinery) but that's it.
One idea is that we only need AVAIL for the block we are currently doing elimination on (well, for FRE - PRE is another story). And we need AVAIL only for values we are going to replace. The first can be exploited by a domwalk unifying elimination and AVAIL computation for FRE, the 2nd one is harder ;) At least sounds like a reason to finally split FRE from PRE ... Richard.
