On 31.10.2023 08:43, Jan Beulich wrote: > What I would consider scope creep I > specifically didn't even ask for: I'd like this macro to be overridable > by an arch. Specifically (see my earlier naming hint) I'd like to use > x86's BMI insn BLSI in the context of "x86: allow Kconfig control over > psABI level", when ABI v2 or higher is in use.
Actually I need to withdraw that. It meanwhile occurred to me that the compiler ought to recognize this pattern. And indeed gcc doesn't even have a builtin for it; its BMI intrinsic for BLSI (on x86 that is) specifically expands to x & -x, which the backend then is expected to deal with as appropriate. And indeed it can be observed to, with my "x86: allow Kconfig control over psABI level" in place. Just as a reminder: I'd still like to see the further renaming done (to ISOLATE_LSB()). If I was to commit this patch, I'd be fine doing so while committing. Jan
