Libtorrent example: /bin/sh ../../libtool --tag=CXX --mode=compile x86_64-pc-linux-gnu-g++ -DHAVE_CONFIG_H -I. -I/tmp/portage/net-libs/libtorrent-0.12.9/work/libtorrent-0.12.9/src/tracker -I../.. -I/tmp/portage/net-libs/libtorrent-0.12.9/work/libtorrent-0.12.9/src/tracker -I/tmp/portage/net-libs/libtorrent-0.12.9/work/libtorrent-0.12.9/src/tracker/.. -I/tmp/portage/net-libs/libtorrent-0.12.9/work/libtorrent-0.12.9 -march=native -O2 -g -DDEBUG -fvisibility=hidden -I/usr/include/sigc++-2.0 -I/usr/lib64/sigc++-2.0/include -c -o tracker_dht.lo /tmp/portage/net-libs/libtorrent-0.12.9/work/libtorrent-0.12.9/src/tracker/tracker_dht.cc Rtorrent example: x86_64-pc-linux-gnu-g++ -DHAVE_CONFIG_H -I. -I/tmp/portage/net-p2p/rtorrent-0.8.9/work/rtorrent-0.8.9/src/ui -I../.. -I/tmp/portage/net-p2p/rtorrent-0.8.9/work/rtorrent-0.8.9/src/ui -I/tmp/portage/net-p2p/rtorrent-0.8.9/work/rtorrent-0.8.9/src/ui/.. -I/tmp/portage/net-p2p/rtorrent-0.8.9/work/rtorrent-0.8.9 -march=native -O2 -g -DDEBUG -I/usr/include/sigc++-2.0 -I/usr/lib64/sigc++-2.0/include -I/usr/include -c -o element_text.o /tmp/portage/net-p2p/rtorrent-0.8.9/work/rtorrent-0.8.9/src/ui/element_text.cc amd64box ~ # emerge --info | grep CXX CXXFLAGS="-march=native -O2"
This was fixed long time ago.