after an update of clang today from a version about 3 weeks ago I had to add "-target-feature +mmx" to my command line in order to get code including xmmintrin.h compileable. Until then "-target-feature +sse4"
was sufficient. Is that intended and what has changed?
-mmmx and -mno-mmx were separated from the SSE flags for gcc compatibility.
I don't know about the gcc specifics (at least not from home). However clang's xmmintrin.h still includes mmintrin.h. Maybe that should be changed too. AFAIK newer processors don't support mmx anymore. Thus the separation makes sense at all.