On Wed, 5 Aug 2020 at 18:00, Richard Henderson <richard.hender...@linaro.org> wrote: > I've always assumed we'd never get rid of all of them. > > Older ones like XSCALE are obvious, but I don't think there's a clear > indicator > for V{5,6,7,8} either.
MIDR.Architecture lets you distinguish v4/v4T/v5/v5T/v5TE/v5TEJ/v6, and there are also some separate per-feature ID register fields for things which we currently hang off those ARM_FEATURE_Vx flags. In theory all the v7-and-later stuff should have its own ID register field... Regardless, it's hard to see a clear benefit from a hypothetical concerted effort to convert all the ARM_FEATURE_* uses to ID register checks, though we might choose to convert a few here and there if we need to overhaul the code anyway. thanks -- PMM