>Really?
>Really do you want me to answer on the question "why there is no any sense
>repeat 42 times some tests on the source code configuration stage?" ??

Yes, because you repeatedly make the mistake of assuming that one
dimension of a problem is the only one that matters, and that all
other considerations are irrelevant.

Just to be clear ..

So you want to say that I'm making mistake because I'm assuming that speed/performance matters?

I think people pointed out that GCC bundles several subsystems that are independently developed and therefore have their own autoconf processes. Trying to merge them together, like you propose, would make sense from the performance point of view but does not reflect the reality of how they are developed.

Jonathan is saying that efficiency has multiple axis: there's the simple 'CPU cycles' but there are others, e.g. 'how many keystrokes does a developer have to type, and how often' and 'how many people have to coordinate changes to this file'. 

It's good that people like you re-examine various assumptions, because some things can be improved on all axes simultaneously, and changing them makes life immediately better for everyone.

Other times, however, improvements on one axis make other axes worse, at least initially. If that's the case, you have to persuade people to adopt this change,  by addressing their concerns and showing a clear path forward, in a way that's acceptable to everyone. This is usually harder than solving the specific technical issue.