[SunRescue] Re: GCC code generation sucks....

[Greg A. Woods]

[ On Sunday, April 29, 2001 at 16:17:27 (-0400), Dave McGuire wrote: ]
> Subject: Re: GCC code generation sucks....  ([SunRescue] IPC dead as doornail... possible causes?    )
>
>   GCC's performance on more modern processors, however, suffers due to
> the fact that the GCC development team seems to have "intel blinders"
> on...they don't seem to understand that there's more to the computing
> world than crappy Intel processors.  So GCC's performance on the
> Pentium-of-the-week is great, while on everything else it blows dog.

I wouldn't go so far as to say that.

Indeed I've always trusted Sun's compiler on SunOS-4 (i.e. for both
mc68k and Sparc) more than GCC, though by the time GCC-2.x came out it
was getting about as good.  In theory at least EGCS now has an even
better optimiser.

Certainly for some RISC processors, such as MIPS, generating good code
is an incredibly difficult job (and can literally never be done well by
a human!).

Note that GCC does use some of the better and more recent optimisation
techniques in the industry too.  GCC supposedly doesn't even do as well
as Intel's compiler for iAPx86 platforms.  Claiming they've got "intel
blinders" on is flat out wrong.  They know more about how many different
processors there are/were out there in the world, than anyone else could!

However unfortunately the GCC team doesn't have anywhere near the
resources for all their target processors combined as even one
commercial compiler that's targeted only to a single processor, so
expecting it to be as good as any such compiler is not realistic.

GCC does fly well on some platforms and has even been chosen as the base
compiler for some commercial operating systems.  One example that comes
to mind is mc88k, where Data General used it for DG-UX.  Note also that
they put a great deal of their own effort into improving GCC for mc88k
and of course contributed their results back to the community.

Now if Red Hat, VAlinux, and similar such companies, would all throw as
much money to the GCC team (or some commercial compiler developer who
could work well with the GCC team) as any one of Intel, DEC(compaq),
Sun, etc. throw to their proprietary compiler teams, GCC would probably
beat out most commercial compilers on all platforms!  :-)

-- 
							Greg A. Woods

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