Re: abysmal code generated by gcc 3.2

[Denys Duchier <Denys dot Duchier at ps dot uni-sb dot de>]

Mike Stump <mrs@apple.com> writes:

> Well, if all else fails, you can build compilers from the cvs tree,
> and binary search for when code generation changed from good to bad
> for you.

That possibly could reveal what's at the root of the issue, but it
would not solve my problem which is to get my application to perform
well on today's distributions.  Every Linux distribution is now based
on gcc 3.2, thus I must get the Oz emulator to perform well when
compiled with it.

> I'd do this only after experimenting with the top of the tree (to
> ensure performance hasn't already returned for you),

yes, I definitely plan to experiment with gcc out of CVS to see what I
can expect in the future.  However, for the moment (1) I must solve
the remaining issues introduced with the switch to the new ABI, (2) I
need to make it reasonably fast across the board for the current user
base.

> and experimenting
> with all the relevant compiler flags, for example, see the following
> parameters: max-inline-insns-single, max-inline-insns,
> max-inline-slope, and min-inline-insns.

uh? except for max-inline-insns, I never heard of the others.  Are
these new (and what do they mean? - is that maybe documented in CVS).

Cheers,

-- 
Dr. Denys Duchier			Denys.Duchier@ps.uni-sb.de
Forschungsbereich Programmiersysteme	(Programming Systems Lab)
Universitaet des Saarlandes, Geb. 45	http://www.ps.uni-sb.de/~duchier
Postfach 15 11 50			Phone: +49 681 302 5618
66041 Saarbruecken, Germany		Fax:   +49 681 302 5615