> In general you CAN optimise assembly more than C in all cases but are you
> better at optimising assembly than the people who wrote the C compiler?

The fact to be working in a C Compiler producer company, writing
compilers, doesn't mean a person knows more than everybody else in the
world that is NOT working at that company. I am not saying either that
they know less, but for sure there is NOT a selection exam to choose the
best of the world software writers to be part of such software company.

During my professional life I turned to be a specialist in a half dozen
things, and I can say that there is this false presumption that only
specialists can produce something useful. They just know more about
something because they got more contact with the subject, but it doesn't
mean they are more intelligent about it. They can collect much more
information about the subject, but it doesn't mean they will use all of
it, or even remember that they have it.

So, the answer to the above question is *YES*, and probably lots of
other people too.