Bad performance on alpha? (make buildworld)

[Alain Fauconnet]

On Mon, Feb 23, 2004 at 07:21:03PM +0100, Oliver Lehmann wrote:
> Hi,
> 
> I run several buildworld's on both, an Alpha EV56 and a Intel PII. I'm
> wondering that the Pentium beats the Alpha. Both systems have INVARIANTS*
> and WITNESS* disabled. Furthermore, no special tweakups - nearly "out of
> the box" configured.
> 
(rest deleted)

Just a wild guess: I happen to have had the luck of  counting  one  of
the very few guys outside of the US involved in the development of the
Alpha  chip among my friends. I remember the long fascinating talks we
were  having  when Alpha came out (touch of nostalgia here ;-) and him
explaining to me how difficult it was to write a good compiler for the
beast.

The  optimization  pass  is  a  real  nightmare.  At that time we were
talking  about  the EV4 chip, I can only imagine that things have gone
worse with the newer generation  chips  supporting  more  parallelism,
deeper prefetch, branch prediction and all that.

So I'm not overly  surprised  that  a  job  made  almost  entirely  of
compiles takes a significant  longer time, even though the CPU is more
powerful.

Now  I'll  let  it  to the really knowledgeable persons to give better
reasons ;-)

Greets,
_Alain_