https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80298
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The other way to get rid of those errors would be wrap the MMX/3dNOW headers
into additional #pragma GCC target("sse") for 64-bit, but then you wouldn't be
able to use the MMX intrinsics with -mno-sse -mmmx -m64 (of course, nobody
really should be using those, but that is a different matter), while with the
proposed patch you can use them, you just can't have your own non-inlined
functions that have __m64 etc. as arguments or return values, because that
requires -msse. As long as all functions pass __m64 by reference or take it
only from memory or deal with it only internally, -mmmx -mno-sse -m64 should be
fine.
