Thanks for the helpful information! But I'm still checking with hardware team about the family/model/stepping numbers for Cascadelake which are not officially disclosed by Intel (to my best knowledge).
Wei Martin Liška <mli...@suse.cz> 于2018年11月26日周一 下午10:00写道： > > On 11/26/18 12:18 PM, Jakub Jelinek wrote: > > On Mon, Nov 26, 2018 at 12:03:53PM +0100, Martin Liška wrote: > >>> For Cascade Lake the model number is the same as Skylake Server, > >>> it can only be distinguished based on the stepping (5 vs 4) > >> > >> Very interesting, probably the first time a distinguish is based on > >> stepping number? > > > > Wouldn't it be better to distinguish it based on availability of VNNI, like > > we do for unknown family/model? > > > >>> Like gcc -mcpu=native needs to learn about this. > >> > >> I'm attaching patch that does that. Note that it's completely untested as > >> I don't have > >> access to any of the new machines (Skylake server). > > Would be possible, the only ugly place would be in > libgcc/config/i386/cpuinfo.c where we > call: > > get_intel_cpu (family, model, stepping, brand_id); > /* Find available features. */ > get_available_features (ecx, edx, max_level, &avx512_vnni); > > one would need a feature to distinguish CPU model. Do we really want that? > > Martin > > > > > Jakub > > >
