atomic_thread_fence() semantics

[Mattias Rönnblom]

Hi.

I have this code:#include <stdatomic.h>

int ready;
int message;

void send_x4711(int m) {
    message = m*4711;
    atomic_thread_fence(memory_order_release);
    ready = 1;
}

When I compile it with GCC 7.2 -O3 -std=c11 on x86_64 it produces the 
following code:
send_x4711:
.LFB0:
.LVL0:
        imul    edi, edi, 4711
.LVL1:
        mov     DWORD PTR ready[rip], 1
        mov     DWORD PTR message[rip], edi
        ret

I expected the store to 'message' and 'ready' to be in program order.

Did I misunderstand the semantics of 
atomic_thread_fence+memory_order_release?
Regards,
        Mattias