https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89275
--- Comment #3 from Bill Schmidt <wschmidt at gcc dot gnu.org> --- I just heard back from the performance lead. He indicates that they can reproduce the numbers from 9.0 trunk (compiled Feb 8, versus Feb 3 as reported by Phoronix), but the numbers from 8.2 as tagged do not reproduce. GCC 9 degrades a little on Add, but is in the noise range for Set/Append. If we accept this (and I see no reason not to at the moment), we still have the question of why GCC lags LLVM on this benchmark for *both* 8 and 9. So we will continue to work on root-cause analysis.