Multilib
Exherbo supports multilib natively, but it's not enabled by default yet.
First we enable the multilib profile by changing the profiles variable in arbor.conf.
File: /etc/paludis/repositories/arbor.conf
...
profiles = ${location}/profiles/amd64/multilib
...
Remove the CHOST entry from bashrc and either set C{,XX}FLAGS which apply to all C targets, or define individual ones.
File: /etc/paludis/bashrc
CFLAGS="-march=native -pipe -O2"
CXXFLAGS="${CFLAGS}"
#MULTIBUILD_C_32_USER_CFLAGS="-march=native -pipe -O2"
#MULTIBUILD_C_32_USER_CXXFLAGS="${MULTIBUILD_C_32_USER_CFLAGS}"
#MULTIBUILD_C_64_USER_CFLAGS="-march=native -pipe -O2"
#MULTIBUILD_C_64_USER_CXXFLAGS="${MULTIBUILD_C_64_USER_CFLAGS}"