关于gentoo中mplayer的几个问题

Amorous

1，我注意到“Detected host architecture: i386”这样一句，请问这是怎么回事？我的应该是i686吧？
2，rmvb不能播放了，配置的时候有这样一句：“Failed to find a Win32 codecs dir at /usr/lib/win32!”可是我明明把那些东西都放在那里呢，而且原来可以播放的，现在修改了make.conf所以才重新编译，不料不行了（我修改了对应的ebuild，包含了codecs的目录，都在/usr/lib/win32目录下）
3,我的cpu是xp2000，cpuinfo：“flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow”，这个是不是支持“3dnowex sse mmx2”这三个useflag?我在终端中运行他的时候，会显示“MMX2 supported but disabled 3DNowExt supported but disabled”，这是怎么回事？

Amorous

我用gcc4
我的emerge info:
System uname: 2.6.12-gentoo-r10 i686 AMD Athlon(tm) XP 2000+
Gentoo Base System version 1.6.13
dev-lang/python: 2.3.5-r2
sys-apps/sandbox: 1.2.12
sys-devel/autoconf: 2.13, 2.59-r6
sys-devel/automake: 1.4_p6, 1.5, 1.6.3, 1.7.9-r1, 1.8.5-r3, 1.9.6-r1
sys-devel/binutils: 2.16-r1
sys-devel/libtool: 1.5.18-r1
virtual/os-headers: 2.6.11-r2
ACCEPT_KEYWORDS="x86"
AUTOCLEAN="yes"
CBUILD="i686-pc-linux-gnu"
CFLAGS="-march=athlon-xp -mtune=athlon-xp -mfpmath=sse,387 -mmmx -msse -m3dnow -pipe -Os -fomit-frame-pointer -fforce-addr -finline-functions -finline-limit=400 -freorder-blocks -freorder-functions -falign-functions -falign-labels -falign-loops -falign-jumps -frename-registers -fweb -funit-at-a-time -fbranch-target-load-optimize -fbranch-target-load-optimize2"
CHOST="i686-pc-linux-gnu"
CONFIG_PROTECT="/usr/kde/3.4/env /usr/kde/3.4/share/config /usr/kde/3.4/shutdown /usr/lib/X11/xkb /usr/share/config"
CONFIG_PROTECT_MASK="/etc/gconf /etc/terminfo /etc/env.d"
CXXFLAGS="-march=athlon-xp -mtune=athlon-xp -mfpmath=sse,387 -mmmx -msse -m3dnow -pipe -Os -fomit-frame-pointer -fforce-addr -finline-functions -finline-limit=400 -freorder-blocks -freorder-functions -falign-functions -falign-labels -falign-loops -falign-jumps -frename-registers -fweb -funit-at-a-time -fbranch-target-load-optimize -fbranch-target-load-optimize2"
DISTDIR="/usr/portage/distfiles"
FEATURES="autoconfig ccache distlocks sandbox sfperms strice strict"
GENTOO_MIRRORS="ftp://linux.ntcu.net/dists/gentoo/ http://mirror.gentoo.gr.jp http://www.zentek-international.com/mirrors/gentoo/ http://gentoo.ccccom.com http://mirror.tucdemonic.org/gentoo/ http://gentoo.math.bme.hu http://gentoo.inode.at/ http://gentoo.mirrors.pair.com/"
LC_ALL="zh_CN.GB18030"
LDFLAGS="-Wl,-O1"
MAKEOPTS="-j2"
PKGDIR="/usr/portage/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
SYNC="rsync://rsync.asia.gentoo.org/gentoo-portage"
USE="x86 3dnow 3dnowex X acpi alsa arts avi bash-completion berkdb bitmap-fonts cdr cjk crypt dvd eds emboss encode esd fam foomaticdb fortran gdbm gif gnome gpm gstreamer gtk gtk2 imlib java jpeg junit libg++ libwww mad mikmod mmx mmx2 motif mp3 mpeg ncurses nls nptl nptlonl
y ogg oggvorbis opengl oss pam pdflib perl png python quicktime readline sdl spell sse ssl tcpd tiff truetype truetype-fonts type1-fonts unicode usb userlocales vorbis xml2 xmms xv zlib video_cards_nvidia userland_GNU kernel_linux elibc_glibc"
Unset: ASFLAGS, CTARGET, LANG, LINGUAS, PORTDIR_OVERLAY