https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81763
--- Comment #2 from Mike Lothian <mike at fireburn dot co.uk> --- Sorry I should have been more clear, this is LLVM trunk I'm using these flags: CFLAGS="-O2 -march=native -pipe" CXXFLAGS="-O2 -march=native -pipe" LDFLAGS="-Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed" gcc -v Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/7.1.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: /var/tmp/portage/sys-devel/gcc-7.1.0-r1/work/gcc-7.1.0/configure --host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/7.1.0 --includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/7.1.0/include --datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/7.1.0 --mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/7.1.0/man --infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/7.1.0/info --with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/7.1.0/include/g++-v7 --with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/7.1.0/python --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 7.1.0-r1 p1.1' --disable-esp --enable-libstdcxx-time --enable-shared --enable-threads=posix --enable-__cxa_atexit --enable-clocale=gnu --enable-multilib --with-multilib-list=m32,m64 --disable-altivec --disable-fixed-point --enable-targets=all --disable-libgcj --enable-libgomp --disable-libmudflap --disable-libssp --disable-libcilkrts --enable-libmpx --enable-vtable-verify --enable-libvtv --enable-lto --with-isl --disable-isl-version-check --enable-libsanitizer --disable-default-pie --disable-default-ssp Thread model: posix gcc version 7.1.0 (Gentoo 7.1.0-r1 p1.1)