micha@uunet.uu.net (Micha Meier) (04/26/89)
We have a problem with the C optimizer in 4.0: if we use anything higher
than cc -O1, the resulting code uses no hardware registers and so it runs
about half the speed of the non-optimized program (!). I first thought
that the optimizer does not work at all but then we found out that for
some programs it works just fine. Does anybody know what criteria
/usr/lib/iropt uses to allocate program variables to hardware registers?
I don't know whether this is a bug or a feature but in any case we need a
solution.
The problem is crucial since the concerned function is the core of our
system and when it runs slowly, so does the whole system. Please answer
by email.
--Micha {pyramid,unido}!ecrcvax!micha