On Wed, Dec 4, 2024 at 5:55 PM H. Peter Anvin <hpa@xxxxxxxxx> wrote: > > On December 4, 2024 5:16:50 AM PST, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote: > >On Wed, Dec 04 2024 at 11:30, Arnd Bergmann wrote: > >> From: Arnd Bergmann <arnd@xxxxxxxx> > >> > >> Both 32-bit and 64-bit builds allow optimizing using "-march=atom", but > >> this is somewhat suboptimal, as gcc and clang use this option to refer > >> to the original in-order "Bonnell" microarchitecture used in the early > >> "Diamondville" and "Silverthorne" processors that were mostly 32-bit only. > >> > >> The later 22nm "Silvermont" architecture saw a significant redesign to > >> an out-of-order architecture that is reflected in the -mtune=silvermont > >> flag in the compilers, and all of these are 64-bit capable. > > > >In theory. There are quite some crippled variants of silvermont which > >are 32-bit only (either fused or at least officially not-supported to > >run 64-bit)... > Yeah. That was a sad story, which I unfortunately am not at liberty to share. Are they available in the wild? What I know with that core are Merrifield, Moorefield, and Bay Trail that were distributed in millions and are perfectly available, but I never heard about ones that are 32-bit only. The Avoton and Rangley I have read about on https://en.wikipedia.org/wiki/Silvermont seems specific to the servers and routers and most likely are gone from use. -- With Best Regards, Andy Shevchenko
