My assumption (perhaps incorrect) is that once pcc is up to speed it
might well generate better
code for the vax than gcc does, with less cpu and memory.
I wouldn't count on it. Today's pcc is of course better than "traditional"
pcc but, for what it's worth, when I was running a real 11/750 as a
fairly busy UUCP and Usenet site, I eked at least another year of life
out of the tired old beast just by recompiling everything I could with
GCC -- which I think at the time was 1.21. This was after we'd long
since switched from the 4.3 UUCP to Vixie's UUCP to Taylor UUCP,
moved the modems from DHU11 to DMF32 and removed all vestige of DZ
serial controllers from the system.
My hazy memory tells me that compress(1) got around 25% faster when
compiled with GCC. Modern GCC probably does better still.