This patch series improves -fprefetch-loop-arrays pass through small fixes and tweaks, and then enables it for several AArch64 cores.
My tunings were done on and for Qualcomm hardware, with results varying between +0.5-1.9% for SPEC2006 INT and +0.25%-1.0% for SPEC2006 FP at -O3, depending on hardware revision. This patch series enables restricted -fprefetch-loop-arrays at -O2, which also improves SPEC2006 numbers Biggest progressions are on 419.mcf and 437.leslie3d, with no serious regressions on other benchmarks. I'm now investigating making -fprefetch-loop-arrays more aggressive for Qualcomm hardware, which improves performance on most benchmarks, but also causes big regressions on 454.calculix and 462.libquantum. If I can fix these two regressions, prefetching will give another boost to AArch64. Andrew just posted similar prefetching tunings for Cavium's cores, and the two patches have trivial conflicts. I'll post mine as-is, since it address one of the comments on Andrew's review (adding a stand-alone struct for tuning parameters). Andrew, feel free to just copy-paste it to your patch, since it is just a mechanical change. All patches were bootstrapped and regtested on x86_64-linux-gnu and aarch64-linux-gnu. -- Maxim Kuvyrkov www.linaro.org
