https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173
--- Comment #21 from rguenther at suse dot de <rguenther at suse dot de> --- On Mon, 26 Jan 2015, ramana at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=62173 > > --- Comment #19 from Ramana Radhakrishnan <ramana at gcc dot gnu.org> --- > (In reply to Richard Biener from comment #18) > > It's probably not correct to simply transfer range info from *idx to > > iv->base. > > Instead SCEV analysis needs to track the range of CHREC_LEFT when it > > analyzes > > the SSA use-def chain. That's of course a much bigger change :/ > > > > The patch may still help in some cases - I suppose the original testcase is > > reduced from sth else? > > Not sure if this is related to comment #c2 where the reference is to a 15% > regression in bzip2 compress at O3. Sebastian could probably confirm. > > I don't think we can ignore the regression though, can we ? We should try not to.
