https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81388
--- Comment #4 from Nick Terrell <terrelln at fb dot com> --- Good point Marc. The generated assembly is wrong because the loop should be run once, but it is run 2^63 times. Changing the amount dst is incremented by to 4 makes it run 2^62 times, and changing it to 8 makes it run 2^61 times.
