[Bug middle-end/108712] Missing optimization with memory-barrier

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108712

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |inline-asm,
                   |                            |missed-optimization

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The inline-asm is causing GCC not to optimize the code.
Doing the following on x86_64 allows GCC to optimize the g load/stores out of
the loop:
static volatile int flag;
static int g; 

void func(void) {
    for(int i = 0; i < 20; i++) {
        ++g;
        if (flag) {
            flag = 0;
        }
     }
}