gcc and compiling speed

[Theo de Raadt]

> > > Marc,
> > > Now I know you have been asked before every time you bring up on the
> > > GCC's mailing list about a set of preprocessed source for openbsd so
> > > that the speed of GCC will improve.
> > 
> > How will this improve the speed of gcc?
> > 
> > Are pre-processed headers the way that gcc3 is going to recover
> > the speed that it has lost?
> 
> I found pretty Andrew's request very confusingly worded (sorry
> Andrew!), so let me rephrase it: preprocessed (-E, -save-temps) output
> for specific test cases that have slowed down.  This is what people ask
> Marc for every time he reports slowdown numbers, and so far he hasn't
> provided any.

Is include file parsing a time critical component of gcc?

Is it a part that has slowed down a lot?

Quite frankly, I bet that cpp performance is entirely lost in the
noise...

> Not that we're disputing that GCC has slowed down.  But without
> specific testcases that have regressed, it's hard to do anything about
> it.

Please.... an entire operating system compiles slower, on every
architecture we have tested it, and I have not heard of any case which
compiles faster (except sha1.c on sparc cpus, where gcc got into some
optimizer loop).