app-pda/p3nfs-5.18-r1 compile and works on amd64. Please add ~amd64 KEYWORD. :)
Portage 2.0.53_rc7 (default-linux/amd64/2005.1, gcc-3.4.4, glibc-2.3.5-r3, 2.6.13-gentoo-r5 x86_64) ================================================================= System uname: 2.6.13-gentoo-r5 x86_64 AMD Athlon(tm) 64 Processor 3200+ Gentoo Base System version 1.12.0_pre9 ccache version 2.4 [enabled] dev-lang/python: 2.4.2 sys-apps/sandbox: 1.2.13 sys-devel/autoconf: 2.13, 2.59-r7 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: 2.16.1 sys-devel/libtool: 1.5.20 virtual/os-headers: 2.6.11-r2 ACCEPT_KEYWORDS="amd64 ~amd64" AUTOCLEAN="yes" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-O2 -march=athlon64 -fomit-frame-pointer -pipe" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3/share/config /usr/lib/X11/xkb /usr/share/config /var/qmail/control" CONFIG_PROTECT_MASK="/etc/gconf /etc/init.d /etc/splash /etc/terminfo /etc/texmf/web2c /etc/env.d" CXXFLAGS="-O2 -march=athlon64 -fomit-frame-pointer -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig candy ccache collision-protect distlocks keeptemp multilib-strict noauto parallel-fetch sandbox sfperms strict userpriv usersandbox" GENTOO_MIRRORS="http://distfiles.gentoo.org http://distro.ibiblio.org/pub/linux/distributions/gentoo" MAKEOPTS="-j2" PKGDIR="/usr/portage/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/bmg-main /usr/local/portage" SYNC="rsync://rsync.gentoo.org/gentoo-portage" USE="amd64 GAPING_SECURITY_HOLE X Xaw3d aac aim alsa avi bash-completion berkdb bitmap-fonts bluetooth buttons bzip2 cdparanoia cdr crypt cups curl dga directfb dvd dvdread emacs emboss encode fam fbcon flac foomaticdb fortran gdbm gif gimpprint gpgme gpm gstreamer gtk gtk2 hlapi icq imagemagick imap imlib ipv6 irc jabber java javascript jpeg justify leim libcaca libwww lzw lzw-tiff mad mikmod mng motif mozdevelop mozsvg mp3 mpeg mpi msn ncurses new-login nptl nvidia offensive ogg oggvorbis opengl oss pam pcre pdf pdflib perl png python quicktime readline real rtc samba scanner sdl sms spell ssl svg symlink tcpd tetex tiff truetype truetype-fonts type1-fonts udev unicode usb userlocales vorbis wmf xml2 xmms xpm xprint xv xvid yahoo zlib userland_GNU kernel_linux elibc_glibc" Unset: ASFLAGS, CTARGET, LANG, LC_ALL, LDFLAGS, LINGUAS
I can confirm it works.
marked ~amd64; sorry for the delay!