/etc/make.conf
# These settings were set by the catalyst build script that automatically
# built this stage.
# Please consult /usr/share/portage/config/make.conf.example for a more
# detailed example.
CHOST="x86_64-pc-linux-gnu"
CFLAGS="-march=core2 -mtune=generic -O3 -pipe"
CXXFLAGS="${CFLAGS}"
MAKEOPTS="-j9"
# WARNING: Changing your CHOST is not something that should be done lightly.
# Please consult http://www.gentoo.org/doc/en/change-chost.xml before changing.
CHOST="x86_64-pc-linux-gnu"
# These are the USE flags that were used in addition to what is provided by the
# profile used for building.
USE="-gnome -kde -cups -gtk -alsa -canna -dvd -cdr mmx sse sse2"
GENTOO_MIRRORS="ftp://ftp.iij.ad.jp/pub/linux/gentoo/"
SYNC="rsync://rsync.jp.gentoo.org/gentoo-portage"
CFLAGS の見直し
（gcc 4.2 から -march=native が導入された）
（USE の見直し）
全体的な見直しが必要かも！
おもに CFLAGS 調べんとあかん for i7 or Xeon