llvm dev - Nov 2021 - PowerPC LLVM support much appreciated

Hello!

On 11/10/21 14:47, Nemanja Ivanovic wrote:
> While I certainly sympathize with enthusiast developers working on obsolete
> systems and doing some pretty cool hacking, I agree that the goals of an
> actively developed back end and an enthusiast-maintained back end are
> rather different.
> 
> Any code for Darwin PPC in the upstream back end is a burden for new
> development on actively supported platforms such as Linux, AIX and FreeBSD.
> Similarly, all the new code added for those actively supported platforms as
> well as new hardware is a burden for enthusiast developers looking to
> maintain support for obsolete platforms. As such, I believe that
> coexistence in the same codebase provides little benefit while causing a
> fair bit of friction. I would suggest that an out-of-tree back end for
> Darwin PPC would reduce this friction.
I fully understand the reasoning and I absolutely agree with you. However, the
the actual changes required to get LLVM to build on Darwin/PPC seem to be rather
minimal, given when we ignore the additional tests which is why I don't
think
that Darwin/PPC would actually be such a maintenance burden.

It would be different if there was no support for either Darwin or PPC at all,
but
that's not the case. It's more a question of tying to pieces of string
together
which are already there.

Adrian

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz at debian.org
`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
  `-    GPG: 62FF 8A75 84E0 2956 9546  0006 7426 3B37 F5B5 F913

On Wed, Nov 10, 2021 at 9:07 AM John Paul Adrian Glaubitz via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> I fully understand the reasoning and I absolutely agree with you. However,
> the
> the actual changes required to get LLVM to build on Darwin/PPC seem to be
> rather
> minimal, given when we ignore the additional tests which is why I don't
> think
> that Darwin/PPC would actually be such a maintenance burden.
>
> It would be different if there was no support for either Darwin or PPC at
> all, but
> that's not the case. It's more a question of tying to pieces of
string
> together
> which are already there.

I think there was a *lot* more behavior specific to the intersection of
Darwin+PPC (not applicable to other PPC OSes or other Darwin
architectures), than one might think (and than has been mentioned on this
thread so far). Fortunately, I don't recall details -- but I rather doubt
it'll be such a trivial change to resurrect Darwin PPC support.

Might I suggest installing Linux on old Mac PPC hardware, instead? MacOS
10.5 was the last release able to run on PPC, and hasn't been updated in 12
years.
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