Question for maintainers: ARCv3 port feasibility

[Andrew Stubbs]

Dear GCC Maintainers and Steering Committee,

I'm currently doing a feasibility study and effort estimate for 
upstreaming the existing ARCv3 out-of-tree port [1].

Question: Is there likely to be any objection to adding a new "arc64" 
port in addition to the existing "arc" port?

At this point, I would like to check that the general approach is likely 
to be accepted at the end of the project. Or, at least not rejected for 
this most fundamental of reasons.

The ARCv3 port has been written as a new backend because it is not just 
a simple evolution of the ARC architecture and starting afresh made more 
sense to the developers at the time.  I'm aware that there are some 
precedents for this (sh64, ia64, aarch64), so I think it's probably 
fine, right?

If necessary, I can do a closer analysis of the two ports and figure out 
how to unify them, but of course that's going to take longer and cost more.

Any advice would be appreciated.

Thanks very much,

Andrew


[1] https://github.com/foss-for-synopsys-dwc-arc-processors/gcc/tree/arc64