Basic support of A64FX was added in D75594 but its scheduling model
was missing. This commit adds the scheduling model. Also, this commit
amends/adds some subtarget parameters of A64FX.
The A64FX Microarchitecture Manual, which is source information of
this commit, is on GitHub.
https://github.com/fujitsu/A64FX/
I'm on holiday till January 4. I'll address comments and commit
to GitHub after that.
Is this used anywhere? If so, for what?