https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63334
H.J. Lu <hjl.tools at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|-m16 should turn off MMX, |-m16 should turn off |SSE, AVX as well as |unsupported instructions |VEX-encoded scalar | |instructions | --- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> --- Only VEX/EVEX instructions aren't supported in 16-bit mode.