On Sun, Oct 5, 2014 at 6:06 PM, Bill Schmidt <wschm...@linux.vnet.ibm.com> wrote: > Hi, > > I spent some time thinking about handling vperm instructions in the > analyze_swaps pass, and convinced myself that it isn't necessarily wise > to do so. At the least it will require adding a cost model to the pass > to determine whether a computation involving permutes should be > optimized. > > At this time I don't intend to implement this, but I want to record the > information about how it could be done should it be deemed necessary. > So this patch just adds a few paragraphs of documentation about the > issue. No change in behavior intended. > > I've ensured that rs6000.c still compiles successfully on > powerpc64le-unknown-linux-gnu. Is this ok for trunk? > > Thanks, > Bill > > > 2014-10-05 Bill Schmidt <wschm...@linux.vnet.ibm.com> > > * config/rs6000/rs6000.c (analyze_swaps commentary): Add > discussion of permutes and why we don't handle them.
Great! Thanks, David
