Threading the compiler

[Robert Dewar]

Geert Bosch wrote:

> Given that CPU usage is at 100% now for most jobs, such as
> bootstrapping GCC, there is not much room for any improvement
> through threading.

Geert, I find this a bit incomprehensible, the whole point
of threading is to increase CPU availability by using
multiple cores.

> Even in the best case, large parts of the
> compilation will still be serial.
> In the non-optimizing case, which is so important for the
> compile-debug-edit cycle, almost no parallelism will be possible.

Well that is a completely different issue