> On Fri, May 27, 2016 at 02:50:15PM +0100, Kyrill Tkachov wrote: > > > > As mentioned in > > https://gcc.gnu.org/ml/gcc-patches/2016-05/msg00297.html, > > frename-registers registers can be beneficial for aarch64 and the > > patch at https://gcc.gnu.org/ml/gcc-patches/2016-05/msg01618.html > > resolves the AESE/AESMC fusion issue that it exposed in the aarch64 > > backend. So this patch enables the pass for aarch64 at -O2 and above. > > > > Ok for trunk? > > As you're proposing to have this on by default, I'd like to give a chance to > hear whether there is consensus as to this being the right choice for the > thunderx, xgene1, exynos-m1 and qdf24xx subtargets.
Though there's a slight (<1%) overall improvement on Exynos M1, there just were too many significant (<-3%) regressions for a few significant improvements for me to be comfortable with -frename-registers being a generic default for AArch64. I'll run some larger benchmarks tonight, but I'm leaning towards having it as a target specific extra tuning option. Thank you, -- Evandro Menezes Austin, TX PS: I'm fine with refactoring aarch_option_optimization_table to aarch64_option_optimization_table.
