[fpc-devel] Messages overhead

[Michael Van Canneyt]

On Thu, 15 Jul 2010, Michael Van Canneyt wrote:

>
>
> On Thu, 15 Jul 2010, Graeme Geldenhuys wrote:
>
>> Op 2010-07-14 17:17, Daniël Mantione het geskryf:
>>>> IMO compiler messages slow down compilation a lot.
>>> 
>>> How do you know this, did you benchmark or is it just your opinion?
>> 
>> A few weeks ago, I benchmarked that too (well similar). I did a comparison
>> between Kylix 3 and FPC 2.4.x. When I disabled all compiler message output,
>> FPC compiled the test apps a bit faster that with -va parameter. It wasn't
>> an exhaustive test by any means, but there was a difference. So I would
>> imagine Hans has a point, that removing any calls to message output would
>> reduce compilation even more.
>
> I think that it is more the actual syscalls to write info which make the
> difference than the preparation of the syscall. If you wrote output to the
> terminal, then that is an additional slowing-down factor.
>
> The only way to test the impact of message preparation is to uncomment the

That should of course be 'comment out'...

Michael.

> actual write call, compile with -va and then compile again (clean) with -v0.
>
> Michael.