------- Additional Comments From dberlin at gcc dot gnu dot org 2005-01-20 15:06 ------- Subject: Re: unrolling happens too late/SRA does not happen late enough
On Thu, 20 Jan 2005, rguenth at tat dot physik dot uni-tuebingen dot de wrote: > > ------- Additional Comments From rguenth at tat dot physik dot uni-tuebingen > dot de 2005-01-20 14:57 ------- > Subject: Re: unrolling happens too late/SRA > does not happen late enough > >> Note PR 18755 blocks this if we go the SRA after loop optimization which >> seems like a better idea. > > I do not completely understand this sentence ;) I argue that SRA after > loop is a bad idea, because SRA, in my testcases, will expose new > oportunities for selecting ivs, so we'll need to run another loop after > SRA. Wiat, why are we running SRA twice again at all? I can't figure this out from the bug report, other than seeing that we "could sra c.array", but i don't see why that requires a loop opt first. If you are just trying to convince it that constant indexed accesses to each prat of that array is actually a different element, the structure-aliasing branch will help (though not quite yet, because i've punted on array_ref until i add the code to not punt when we have constant indexed array_ref) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18754
