https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107675
--- Comment #1 from Tamar Christina <tnfchris at gcc dot gnu.org> --- Note that to test this, the glibc version stayed the same. Also when using the default dynamically linked version, pointing to the GCC-12 libstdc++ from the GCC-13 also has no slowdown. So this seems to be something in libstdc++.