https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120361
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution|--- |INVALID
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Because not all x86_64 include PREFETCHW.
You need to use -march=broadwell (or later) to have it emitted.
See
https://stackoverflow.com/questions/63050180/cant-use-m-prefetchw-intrinsic-with-gcc-clang-march-native-on-older-intel-cpu
and others.
