On Wed, May 20, 2020 at 10:37 PM Segher Boessenkool <seg...@kernel.crashing.org> wrote: > > On Wed, May 20, 2020 at 12:30:30PM +0200, Richard Biener wrote: > > I think this is the wrong way to approach this. You're doing too many > > things at once. Try to fix the powerpc regression with the extra > > flag_rtl_unroll_loops, that could be backported. Then you can > > independently see whether enabling more unrolling at -O2 makes > > sense. Because currently we _do_ unroll at -O2 when it does > > not increase size. Its just your patches make this as aggressive > > as -O3. > > Just do a separate flag (and option) for cunroll, instead? > > The RTL unroller is *the* unroller, and has been since forever.
Sorry but that ship has sailed - I don't think we should make -O2 -funroll-loops no longer affect GIMPLE. But sure, what I am proposing is have -frtl-unroll-loops -fgimple-unroll-loops with obvious semantics and -funroll-loops enabling both. Users should not really care about what is RTL or GIMPLE. The split above allows the "bug" to be fixed (even on the branch) without introducing even more target specialities. Richard. > > Segher
