https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111849
--- Comment #2 from Rich Felker <bugdal at aerifal dot cx> --- I agree that volatile isn't the best way to handle memcpy suppression for other purposes - it was just one of the methods I experimented with that led to me discovering this issue, which I found surprising and reported. With regards to impact of this bug, in discussion within the musl libc community where it was found, I did encounter one potentially affected user who is using volatile struct stores to write entire bitfields at once on mmio registers instead of (possibly invalid, at least inefficient) read-modify-write cycles on each bitfield member. I believe their use was unaffected, probably because the whole struct is small enouth that it gets emitted as direct load/store rather than a memcpy call.
