With -funsafe-math-optimizations in USE, the following error message is displayed by the configure script while emerging rrdtool: Your Compiler does not do propper IEEE math ... Please find out how to make IEEE math work with your compiler and let me know fix: add -funsafe-math-optimizations to the filter-flags call in src_compile() Reproducible: Always Steps to Reproduce: !!! Relying on the shell to locate gcc, this may break !!! DISTCC, installing gcc-config and setting your current gcc !!! profile will fix this Portage 2.0.51.19 (default-linux/x86/2005.0, gcc-3.4.3-20050110, glibc-2.3.4.20050125-r1, 2.6.11-rc4-mm1 i686) ================================================================= System uname: 2.6.11-rc4-mm1 i686 Mobile Intel(R) Pentium(R) 4 - M CPU 2.00GHz Gentoo Base System version 1.7.0 Python: dev-lang/python-2.4-r3,dev-lang/python-2.3.5 [2.4 (#1, Mar 30 2005, 19:05:47)] distcc 2.18.3 i686-pc-linux-gnu (protocols 1 and 2) (default port 3632) [enabled] dev-lang/python: 2.4-r3, 2.3.5 sys-devel/autoconf: 2.13, 2.59-r6 sys-devel/automake: 1.5, 1.8.5-r3, 1.9.5, 1.6.3, 1.4_p6, 1.7.9-r1 sys-devel/binutils: 2.15.92.0.2-r7 sys-devel/libtool: 1.5.14 virtual/os-headers: 2.6.8.1-r4 ACCEPT_KEYWORDS="x86 ~x86" AUTOCLEAN="yes" CFLAGS="-O3 -march=pentium4 -fomit-frame-pointer -fsched2-use-superblocks -ffast-math -fno-math-errno -funsafe-math-optimizations -ftracer -funit-at-a-time -pipe" CHOST="i686-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/terminfo /etc/env.d" CXXFLAGS="-O3 -march=pentium4 -fomit-frame-pointer -fsched2-use-superblocks -ffast-math -fno-math-errno -funsafe-math-optimizations -ftracer -funit-at-a-time -pipe" DISTDIR="/usr/portage/distfiles" FEATURES="autoaddcvs autoconfig ccache distcc distlocks sandbox sfperms" GENTOO_MIRRORS="ftp://ftp.lug.ro/gentoo/ http://ftp.iasi.roedu.net/mirrors/gentoo.org/" MAKEOPTS="-j4" PKGDIR="/usr/portage/packages" PORTAGE_TMPDIR="/var/tmp" PORTDIR="/usr/portage" PORTDIR_OVERLAY="/usr/local/portage" SYNC="rsync://bagica.dsd.ro/gentoo-portage/" USE="x86 X alsa apm avi berkdb bitmap-fonts cdr crypt cups curl directfb dvd emacs emboss encode esd fam foomaticdb fortran gdbm gif gnome gpm gtk gtk2 guile imlib irda java jpeg libg++ libwww mad mikmod mmx mmx2 moznocompose moznoirc moznomail mp3 mpeg ncurses oggvorbis opengl oss pam pdflib perl png python quicktime readline samba scanner sdl slang spell sse sse2 ssl tcpd tiff truetype truetype-fonts type1-fonts usb xml xml2 xmms xv xvid zlib" Unset: ASFLAGS, CBUILD, CTARGET, LANG, LC_ALL, LDFLAGS
We don't support CFLAGS such as -funsafe-math-optimizations that's already documented in the gcc documentation to generate invalid code sometimes.
