[Bug target/96327] Inefficient increment through pointer to volatile on x86

[paulmckrcu at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96327

--- Comment #6 from Paul McKenney <paulmckrcu at gmail dot com> ---
(In reply to Marc Glisse from comment #5)
> I don't think bug 3506 has been fixed (its status seems wrong to me). But
> don't worry, there are several other duplicates that still have status NEW
> (bug 50677 for instance).
> This is a sensible enhancement request, I think some gcc backends already do
> a similar optimization, it simply isn't a priority, because volatile almost
> means "don't optimize this".
> At least the difference between the gcc and clang codes matches those other
> PRs. Not sure why you are talking of address computations.

Probably because I was confused by the addressing mode and by wishful thinking,
and yes, you are quite correct.

Anyway, if you look at https://godbolt.org/z/fGze8E, you can see that
Clang/LLVM is using a to-memory addl rather than loading, adding, and storing.