[Bug c++/103966] std::atomic relaxed load, inc, store sub-optimal codegen

[witold.baryluk+gcc at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103966

--- Comment #1 from Witold Baryluk <witold.baryluk+gcc at gmail dot com> ---
Current codegen on gcc 12 on 64-bit x86:

inc_a():
        inc     QWORD PTR x[rip]
        ret
inc_b_non_atomic():
        mov     rax, QWORD PTR y[rip]
        inc     rax
        mov     QWORD PTR y[rip], rax
        ret
y:
        .zero   8
x:
        .zero   8