Looking at the target architectures and compiler backend architectures, I notice use of both of these names:
aarch64. Both of them refer to the 64-bit ARM architecture, why the two names?
Apparently, GCC and other folks went with the name
aarch64. But Apple went with the
arm64 name in their operating systems and compiler backends. So both names got popular, though it seems like
aarch64 is the way to go now since Apple has switched to that too.