[Bug target/103069] cmpxchg isn't optimized

[thiago at kde dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103069

--- Comment #20 from Thiago Macieira <thiago at kde dot org> ---
I think there will be cases where the relaxation makes sense and others where
it doesn't because the surrounding code already does it. So I'd like to control
per emission.

If I can't do it per code block, I suppose I could make a lambda block

  [&]() __attribute__((target("relax-cmpxchg-loop"))) { 
    return __atomic_compare_exchange_weak(....);
  }();

Of course, it might be easier to simply relax it myself at that point.