[Bug target/84719] gcc's __builtin_memcpy performance with certain number of bytes is terrible compared to clang's

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84719

--- Comment #7 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
I wonder if this is not __builtin_memcpy but rather how to optimize and putting
in the lower bytes of an uint64_t.  I think your benchmark is not benchmarking
what you think it is benchmarking.