Tartan C compiler revisited

[jqj at cornell.UUCP]

From: jqj (J Q Johnson)

Now that the flames about optimizing C compilers are dieing down, perhaps
we could return to the subject that spurred the furious debate:  the
merits and demerits of the Tartan C compiler.  Specifically, does anyone
yet have any hands-on experience with it?

Lets grant that the Tartan compiler will change the behavior of some
programs (at least make them run faster!).  Let's grant that it would
NOT be possible to simply recompile the 4.2BSD kernel and expect it
to run correctly.  But would it be possible to recompile the (vast)
majority of user programs distributed as part of 4.2BSD?

Tartan reports quite substantial performance improvements for typical
C programs.  For example, Baskett's "puzzle" program runs 3 times faster
and is 22% smaller in code size compared to PCC.  On the other hand,
none of the sample programs Tartan benchmarks have been hand optimized
(they don't even have any "register" declarations); this suggests that
real Tartan C improvements might be much less than advertised.  I would
be most interested in anyone's actual handson experience; speculation
on possible performance is much less useful.