[Bug c++/71753] Clamp function does not work with O3 optimization

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71753

--- Comment #5 from Marc Glisse <glisse at gcc dot gnu.org> ---
(In reply to Łukasz Spintzyk from comment #4)
> Looking from this point of view is this really invalid?

There is a perfectly valid way to write such code:

"You need to use an unsigned type for this type of computation."