[Bug middle-end/32667] block copy with exact overlap is expanded as memcpy

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=32667

--- Comment #59 from Richard Earnshaw <rearnsha at gcc dot gnu.org> ---
Memcpy must never write beyond the end of the specified buffer, even if reading
it is safe.  That wouldn't be thread safe.