-#if defined(darwin_TARGET_OS) && defined(i386_TARGET_ARCH)
- -- By default, gcc on OS X will generate SSE
- -- instructions, which need things 16-byte aligned,
- -- but we don't 16-byte align things. Thus drop
- -- back to generic i686 compatibility. Trac #2983.
- ++ ["-march=i686"]
-#endif