I just installed and tested lprof (lcms profiling app) on my amd64 machine. The tests worked and it appears that lprof is stable on amd64. At the very least this package should be marked ~amd64 so that others running this arch will test it.
I will mark this has TESTED it works fine. Thanks Portage 2.0.51.22-r2 (default-linux/amd64/2005.0, gcc-3.4.3, glibc-2.3.5-r0, 2.6.12-gentoo-r6 x86_64) ================================================================= System uname: 2.6.12-gentoo-r6 x86_64 AMD Athlon(tm) 64 Processor 3500+ Gentoo Base System version 1.6.13 dev-lang/python: 2.3.5 sys-apps/sandbox: 1.2.11 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, 1.9.5 sys-devel/binutils: 2.15.92.0.2-r10 sys-devel/libtool: 1.5.18-r1 virtual/os-headers: 2.6.11-r2 ACCEPT_KEYWORDS="amd64" AUTOCLEAN="yes" CBUILD="x86_64-pc-linux-gnu" CFLAGS="-march=athlon64 -O2 -pipe -fomit-frame-pointer" CHOST="x86_64-pc-linux-gnu" CONFIG_PROTECT="/etc /usr/kde/2/share/config /usr/kde/3.4/env /usr/kde/3.4/share/config /usr/kde/3.4/shutdown /usr/kde/3/share/config /usr/lib/X11/xkb /usr/lib/mozilla/defaults/pref /usr/share/config /var/qmail/control" CONFIG_PROTECT_MASK="/etc/gconf /etc/splash /etc/terminfo /etc/env.d" CXXFLAGS="-march=athlon64 -O2 -pipe -fomit-frame-pointer" DISTDIR="/usr/portage/distfiles" FEATURES="autoconfig distlocks sandbox sfperms strict" GENTOO_MIRRORS="ftp://mirrors1.netvisao.pt/gentoo/ http://darkstar.ist.utl.pt/gentoo http://distfiles.gentoo.org" LINGUAS="pt en" MAKEOPTS="-j2" PKGDIR="/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage" SYNC="rsync://rsync.europe.gentoo.org/gentoo-portage" USE="amd64 16bit X aalib alsa arts artworkextra avi berkdb bitmap-fonts bzip2 cdparanoia cdr cdrom chroot cpudetection crypt cups curl dvd dvdr dvdread eds emul-linux-x86 encode esd fam foomaticdb fortran gdbm gif gimpprint gmail gmailtimestamps gnome gnome-print gpm gstreamer gtk gtk2 hal imagemagick imlib imlib2 ipv6 java jpeg junit kde lame logitech-mouse lzw lzw-tiff mad mbox mikmod mozilla moznoirc moznomail mp3 mpeg msn ncurses net nls nptl nvidia octave offensive ogg opengl openssh openssl pam pdflib perl png ppds print python qt quicktime rar readline rhythmbox sdl spell ssl startup-notification subtitles tcpd tiff toolbar truetype-fonts type1-fonts usb userlocales videos vorbis xine xml2 xmms xpm xscreensaver xv xvid zlib linguas_pt linguas_en userland_GNU kernel_linux elibc_glibc" Unset: ASFLAGS, CTARGET, LANG, LC_ALL, LDFLAGS
fixed, thanks