Re: [9fans] fast compilers

[Andrew <afrayedknot@thefrayedknot.armory.com>]

> to quote:
>
> > > gcc 3.2.1 is TWICE AS SLOW as gcc 2.95, and the more recent development
> > > are
> > > even SLOWER.
> >
> > What is making successive versions of GCC slower?
>
> I'm not exactly sure.  My theory would be that in their zeal for
> trying to get gcc to catch up to commercial compilers in quality of
> output, they have paid much less attention to ensuring the compiler
> itself is fast.
>
> Sigh.
>
> I wish the plan9 compiler was 100% free.  It's blazingly fast.
>
> And as a developer, I want a fast compiler more than I want fast output.
>

I dont think gcc 3.2.1 is twice as slow as 2.95 (3.2.2 has been released
as a side note). I will not deny that it seems a bit slower than 2.95
but not to any very noticable degree. It is worth pointing out that
between the two versions several new architectures, mostly intel based,
were added (pentium4 and athlon to name a few). I think the big push
towards 3.x was to add support for newer architectures. They've also
hit the stumbling block of complexity. It seems to be a rule that the
bigger and more complex programs get the speed at which they will run
becomes increasingly slower. There are tons of features in gcc, omit the
frame pointer? unsigned bit fields? merge constants between objects? you
can do just about anything you want with it, heck the manual is 8249
lines! I think therein lies the catch22.

it looks like in plan9 as a general rule the designers remembered the
complexity rule, and kept everything small and fast. so no wild crazy
shotgun approach to options. for better or for worse.

Andrew