[llvm] RuntimeLibcalls: Stop opting out of exp10 (PR #148604)

[Nikita Popov via llvm-commits]

nikic wrote:

> I very deliberately do not want any opt-out mechanism. All target based decisions should be explicitly opt-in, and all the places that are opt-out were a mistake. It results in falsely reporting things that don't exist as available, like this. And hard to untangle messes. This is a staging step to getting all logic into tablegen to work towards that

I don't mind it being opt-in, my concern here is that you require a per-arch opt-in, even though the decision should be largely arch-independent (it should depend on os/env).

Like for example, you added the exp10 functions to most of the target system libraries here, but not to *all* of them. What about hexagon, msp430 and xcore? Were those intentionally omitted?

Even if it's not part of the default set, I think this can be structured in a better way that does not require repeating certain parts of the system library in each arch. We should extract the commonalities to the degree it is possible.

https://github.com/llvm/llvm-project/pull/148604