[Bug tree-optimization/59660] We fail to optimize common boolean checks pre-inlining

[hubicka at ucw dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59660

--- Comment #2 from Jan Hubicka <hubicka at ucw dot cz> ---
> I have noticed these, too (-Og is pessimzed by them).  The pattern is generated
> by gimplifying.

I wondered why we can't simply update gimplifier to not produce them?
(this is what I wanted to look into today, it seems pretty common pattern
confusing inliner).
For sure we should better also handle it either in cfg-cleanup or copyprop
for cases that arrise as a result of other optimizations, but it seems it
would speed things up if we did not wrap each predicate calls in its own three
BBs.