https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102294
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|middle-end |target Keywords| |missed-optimization Target| |x86_64 --- Comment #11 from Andrew Pinski <pinskia at gcc dot gnu.org> --- With the target("no-sse") attribute, clang turns off SSE but uses a bunch of 64bit stores for the memset while GCC uses rep;stos. I don't know which one is better on which processors. So someone will need to do timings on that. My bet is clang is tuned towards intel processors more than say a generic AMD processor.