https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81476
Markus Trippelsdorf <trippels at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |trippels at gcc dot gnu.org --- Comment #6 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- Almost all the time is spend in memcpy. Clang with libstdc++ is equally bad. Gcc with "g++ -c -nostdinc++ -nodefaultlibs -lc -isystem /usr/include/c++/v1/ -lm -lc++ -lgcc_s -O3 -I./ test.cpp" is fine. Not sure where the memcpy calls come from.