Re: RFC: remove the "tile" architecture from glibc

[Joseph Myers <joseph at codesourcery dot com>]

On Mon, 4 Dec 2017, Adhemerval Zanella wrote:

> GCC version which does not support m68k (I do not think we have a policy
> to remove deprecated architecture in GCC latest version where there is still
> compiler support in older releases).

In my view, if GCC removes support for an architecture I think that's 
sufficient basis for obsoleting it in glibc as well rather than waiting a 
few more years in which it becomes increasingly hard for people to test 
changes build on that architecture because of the need to use a different 
GCC version there.  However, we don't need to decide this now, as while 
there are suggestions of obsoleting non-cc0 or non-LRA architectures, 
nothing has happened yet in that regard (and even if non-cc0 architectures 
were obsoleted for GCC 8, the removal probably wouldn't be until after GCC 
8 branched, so until then we'd just add --enable-obsolete to the GCC 
configure options for such architectures in build-many-glibcs.py).

> Now back to thread topic, Chris Metcalf gave us some indications that
> tilepro userbase and support do not justify the maintaining effort.  It
> already has kernel ABI incompatibilities (for instance ca768667d873 fix on 
> linux and some atomic unsupported operations that broke the build on
> recent glibc fixes).  I think we could at least remove old tilepro
> support. 

Certainly we can come to separate conclusions about obsoletion for tilegx 
and tilepro.  (Preferably obsoleting tilepro would mean the sysdeps 
directory structure then being simplified to avoid the unnecessary 
directory levels in tile/tilegx, just as after obsoleting ARM old-ABI I 
eliminated the eabi/ subdirectories.)

-- 
Joseph S. Myers
joseph@codesourcery.com