[LLVMdev] [cfe-dev] AArch64 Clang CLI interface proposal

[Amara Emerson]

Upon thinking about this more, we could go with my original proposal about
-march accepting both architectures and cores, which would be a superset of
the values that gcc accepts for -march.

Once we have that, we can simply alias -mcpu to -march, perhaps taking
precedence over -march in the case where they're both specified. This should
give enough compatibility with gcc while also using the -march scheme that
Eric wanted.

On a related note, clang doesn't seem to do anything with -mtune for any
target, not even x86. Do we still want to keep it around? We never make the
distinction in the backend between a core that we do isel for and a core
that we optimize for.

Amara