Comment # 14 on bug 126 from Martin Nowak

Bit-bending I/O is a counter-example against the "no performance needed"
argument, but I still think this can be achieved easily enough with the
existing tools, i.e. by inlining the asm code in your hot loop or writing an
asm function.

for (uint i = 0; i < 32; ++i)
{
    if (data & 1)
        asm { mov r0, #1; str r0, [r3]; }
    else
        asm { mov r0, #2; str r0, [r3]; }
    data >>= 1;
}

Compiler intrinsics for volatile loading/storing could be implemented with zero
overhead and it would be useful for at least one other cases (forced float
rounding to fix excess precision). So I favor this solution, but until then
core.atomic can be used.