Using SSE2 intrinsics with GCC compiler on windows

[Darin Starkey]

 I am trying to use SSE2 intrinsic instructions to do double precision
operations.  I am unable to compile the code with GCC however.  I was
wondering what to do to get it to compile.  My code compiles in
windows Intel compiler just fine.

 I've searched the Internet and have yet to come up with something
useful.  I'm running GCC4.0.2 on Windows.  I'm a very much a noob
here.  My GCC environment was set up by another guy that is since
gone.  I'll be happy to provide more details, just not sure what that
would be.

I have:

#include "emmintrin.h"
…
__m128d                       m_Isa64Src0;
m_Isa64Src0 = _mm_set_pd(0.0, m_Src[0][Element].FloatData);

And get these errors:
: error: '__m128d' does not name a type
: error: 'm_Isa64Src0' was not declared in this scope

Thanks,
Darin