Target deprecation, round three

[Zack Weinberg]

David Edelsohn <dje@watson.ibm.com> writes:

>>>>>> Zack Weinberg writes:
>
> Zack> Please explain why the architectures and OSes supported by i370 but
> Zack> not s390 cannot be migrated to the s390 back end.
>
> 	The IBM S/390 architecture added instructions which do not exist
> in the S/370 architecture, including PC-relative addressing.  The s390
> port relies on and assumes those instructions for its addressing model.

There is no intrinsic reason why the s390 port could not be modified
to support the older addressing models as well.  I recognize that this
might be a substantial amount of effort.

> 	Red Hat delivered a GCC port for the mainframe TPF environment
> which should be merged into the FSF sources.

But they have not bothered to do so, nor am I particularly interested
in badgering them.

It is clear at this point that neither of us will convince the other
to change his position.  Therefore I am requesting the Steering
Committee to make a decision on this issue.

zw