https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109137
--- Comment #21 from Jan Hubicka <hubicka at gcc dot gnu.org> --- Zen 1-3 changes were intentional in the original tuning patch (it is also briefly mentioned in the commit message). By allowing 256 bit AVX moves instead of 64bit integer moves (or 128bit) we can move bigger blocks of memory without loops and it was faster in micro-benchmarks I made on all zens, even on znver1. We also automatically go for 128bit moves when ISA allows that. We could revert that part of backport, but won't we get same hangs with -march=znver4 or core512 which also enables avx512 moves? (I am rebuilding gcc12 to see what happens)
