Transform assertion into optimization hints

Marc Glisse
Mon Sep 17 21:16:00 GMT 2018

On Mon, 17 Sep 2018, François Dumont wrote:

> We talk about it a while back.
> I've run testsuite several times since I have this patch on my local copy. 
> Note that when I implemented it the wrong way tests started to fail so it is 
> clearly having an effect on the generated code.
> * include/bits/c++config [__OPTIMIZE__](__glibcxx_assert): Define as 
> optimization hint
> using __builtin_unreachable.
> Ok to commit ?

I see for instance in bits/regex_automaton.tcc:

               __glibcxx_assert(__m.count(__ref._M_next) > 0);

where __m is a map, which does not look so well suited for a 
__builtin_unreachable. Is it using the wrong macro?

Marc Glisse

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