cpplib: Separate out translation phases 1 and 2

[Devang Patel]

On Friday, April 18, 2003, at 03:33 PM, Neil Booth wrote:

>   I think it's slightly unfair
> you're beating me up on CPP - I suggest you concentrate on areas
> of the compiler that take more than 1-2% for the slow compilations.
> I've put a lot of effort into making CPP fast, and whilst

Don't ignore 1-2% slowdowns. Neglecting them has caused
all of us (those who case for speed) lots of grief when we
encounter that newly released GCC is slower and after weeks of
search we realized that it is not one single patch that caused it. ;-)

(Besides, it is not important for you to care where I spend my time
and energy. You're free to reject my patches and you're free to
ignore my comments.)

Do you think, CPP is responsible for only 1-2% of compile time in
real world programs ? :-)

> I'm maintaining it I intend that CPP stays fast.

Everyone's goal is same, to make it fast, but role of maintainer
carries extra burden!

There are situations when there is no alternative and to accept,
slowdown, I agree. But it is very important to know where we are
and keep measurements around so that later we do not have to start
expensive search on why 3.4 is slower than 3.3.
We did expensive searches for previous releases.

I think, for such a big change it useful to keep before and after
performance numbers.

-Devang