Faster compilation speed

[Neil Booth]

Stan Shebs wrote:-

> Is this assertion based on empirical measurement, and if so, for what
> source code and what system?  For instance, the longest source file
> in GCC is about 15K lines, and at -O2, only a small percentage of
> time is spent messing with files.  If I use -save-temps on cp/decl.c on
> one of my (Linux) machines, I get a total time of about 38 sec from
> source to asm.  If I just compile decl.i, it's about 37 sec, so that's
> 1 sec for *all* preprocessing, including all file opening/closing.

Yes, it's very rare that preprocessing is more than 2% of -O2 time;
it's often less than 1%.  IMO that says more about the efficiency
of the rest than of CPP.

Neil.