Good C compilers for 68000

[Ed Schwalenberg]

We've been using Microsoft's Xenix on Microbar hardware to develop and
run large C applications.  We have reached the point where our programs
are too large and too complex for the compiler provided with Xenix.
Things like limits on the number of #defines, limits on the nesting of
structures, and the like are giving us fits.  And the code produced by
this compiler (a descendent of the MIT port of the portable compiler)
is awful.

Are there better compilers out there?  Where do I get them?  Microsoft
refuses to talk with us since Microbar as OEM is supposed to handle
such things.  Microbar is too busy trying to stay afloat.  Tartan only
has products for the Vax.  We tried a Whitesmiths product several years
ago which was even worse, as was a compiler from a company called Alcyon.
I've heard rumors about the "Green Hills" compiler, but have been unable
to find out how to get in touch with them.  Any help would be appreciated.
Please reply to me directly, as I don't subscribe to these lists.