Re: gcc 3.5 integration branch proposal

[Robert Dewar <dewar@gnat.com>]

Eric Botcazou wrote:

>>That's a pretty reasonable machine at a very reasonable price.

> For a professional developer based in the US, certainly.  I'm not sure GCC 
> should primarily target such a population though.

My goodness, I would not even *consider* asking a professional developer
(someone whose time is worth in the region of $1000 a day to a typical
company) to use this low end machine. So we sure have totally different
perspectives.

The point is that you have to decide on some reasonable benchmark. To
use as the benchmark a machine bought three years ago for far more than
$400 does not seem realistic to me.

A home machine that costs $400 seems to me to be a reasonable definition 
of reasonable hardware. Note that we are not saying that gcc won't work
at all on slower smaller machines, just that we expect relatively poor
performance on such machines. If your valuation of your time is that you 
would rather put up with this poor performance than spend the $400 
that's certainly of course quite reasonable.

At some point you have to make a clear decision of whether you think of
gcc as a hobbyists tool for people who cannot afford any kind of 
reasonable hardware (remember that these days text books cost $100)
or whether it is a serious development tool usable by professionals.
Note that I did not say *only* by professionals, but to distort the
project to say that all code must compile efficiently on machines that 
are three years old seems a mistake to me. Furthermore I think it will
be counterproductive in improving peformance, since it is an unrealistic
requirement.

The idea here is to set a floor for machine performance for which we
consider that the compiler should have good performance. As I said in
my earlier note, the idea is that, at least till we update the baseline,
we do not say to people, get a faster/bigger machine. Instead we 
consider it something that needs fixing.

You might like gcc to give good performance with a three year old 
machine (that translates to approximately a 400MHz Pentium 3 with
32-64 megs of memory), but realistically I don't think this is going
to happen.

Note by the way that the pricing here was for a premium machine brand 
new from a premium vendor. If you want to rummage around the second hand 
market, or build yourself, you can obviously undercut this price (which
annoyingly for example includes the cost of Windows XP)