http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57897
--- Comment #1 from Dongsheng Song <dongsheng.song at gmail dot com> ---
$ ~/cross/x86_64-windows-gcc49/bin/x86_64-w64-mingw32-g++ -v
Using built-in specs.
COLLECT_GCC=/home/cauchy/cross/x86_64-windows-gcc49/bin/x86_64-w64-mingw32-g++
COLLECT_LTO_WRAPPER=/home/cauchy/cross/x86_64-windows-gcc49/libexec/gcc/x86_64-w64-mingw32/4.9.0/lto-wrapper
Target: x86_64-w64-mingw32
Configured with: /home/cauchy/vcs/svn/gcc/trunk/configure
--prefix=/home/cauchy/cross/x86_64-windows-gcc49
--with-sysroot=/home/cauchy/cross/x86_64-windows-gcc49
--build=x86_64-unknown-linux-gnu --host=x86_64-unknown-linux-gnu
--target=x86_64-w64-mingw32 --disable-multilib --disable-nls
--enable-checking=release --enable-languages=c,c++,fortran --with-arch=corei7
--with-tune=generic
Thread model: win32
gcc version 4.9.0 20130714 (experimental) (GCC)
$ cat x.c
#pragma GCC target("sse4a")
$ ~/cross/x86_64-windows-gcc49/bin/x86_64-w64-mingw32-g++ -c
-fasynchronous-unwind-tables x.c
x.c:1:27: sorry, unimplemented: -mno-fentry isn't compatible with SEH
#pragma GCC target("sse4a")
^
