merging cccp and cpplib

[Zack Weinberg]

On Mon, 07 Dec 1998 16:09:30 -0800, Per Bothner wrote:
>> But unfortunately, the last time I checked, the cpplib-based preprocessor wa
>s
>> considerably slower than the cccp.c version.
>
>One other point:  This is quite uninteresting.  What we do care about
>is how standalone cpp plus cc1/cc1plus compares with cc1/cc1plus with
>integrated cpplib.  That is the performance we want to optimize; not
>that of stand-alone cpp.

Right now they are the same thing performance-wise.  cpplib has
several sources of obscene overhead which crush out any gains from
integration.  Also, the speed win from an integrated preprocessor will
be because cc1 won't have to duplicate effort on things like input
file stacks, first stage lexical analysis, etc.  and that has not yet
been implemented.

Some hard numbers: wall-clock time to compile glibc with:

cccp			1:44:37
cpplib standalone	2:28:33
cpplib integrated	2:28:03

same version of cc1, otherwise completely idle system.

zw