https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64172
--- Comment #6 from Siarhei Siamashka <siarhei.siamashka at gmail dot com> --- (In reply to ktkachov from comment #4) > I can't reproduce with -O2 and -mfpu=neon. > Can you please give the exact configuration of your GCC? > The output of 'arm-none-linux-gnueabi-gcc -v' should be good My apologies, you are right. Adding -march=armv7-a option appears to be also needed ("-O2 -march=armv7-a") and I had it as part of my GCC configuration: Using built-in specs. COLLECT_GCC=arm-none-linux-gnueabi-gcc-4.9.2 COLLECT_LTO_WRAPPER=/usr/libexec/gcc/arm-none-linux-gnueabi/4.9.2/lto-wrapper Target: arm-none-linux-gnueabi Configured with: /var/tmp/portage/cross-arm-none-linux-gnueabi/gcc-4.9.2/work/gcc-4.9.2/configure --host=x86_64-pc-linux-gnu --target=arm-none-linux-gnueabi --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/arm-none-linux-gnueabi/gcc-bin/4.9.2 --includedir=/usr/lib/gcc/arm-none-linux-gnueabi/4.9.2/include --datadir=/usr/share/gcc-data/arm-none-linux-gnueabi/4.9.2 --mandir=/usr/share/gcc-data/arm-none-linux-gnueabi/4.9.2/man --infodir=/usr/share/gcc-data/arm-none-linux-gnueabi/4.9.2/info --with-gxx-include-dir=/usr/lib/gcc/arm-none-linux-gnueabi/4.9.2/include/g++-v4 --with-python-dir=/share/gcc-data/arm-none-linux-gnueabi/4.9.2/python --enable-languages=c,c++ --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --disable-nls --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 4.9.2' --enable-libstdcxx-time --enable-poison-system-directories --with-sysroot=/usr/arm-none-linux-gnueabi --disable-bootstrap --enable-__cxa_atexit --enable-clocale=gnu --disable-multilib --disable-altivec --disable-fixed-point --disable-libgcj --disable-libgomp --disable-libmudflap --disable-libssp --disable-libquadmath --enable-lto --without-cloog --enable-libsanitizer --with-arch=armv7-a --with-float=hard Thread model: posix gcc version 4.9.2 (Gentoo 4.9.2)