I found these headers were needed for invoking the different versions of SSE from GCC:
extern "C"
{
#include <emmintrin.h>
#include <mmintrin.h>
}
extern "C"
{
#include <pmmintrin.h>
#include <immintrin.h> // (Meta-header)
}
extern "C"
{
#include <smmintrin.h>
}
In modern versions of the compilers, all the headers seem to be common to Visual Studio and GCC.