I've been asking the compiler people for a storage class modifier that could
be added to type declarations.  The modifier would indicate whether the
data object is stored in big-endian or little-endian format.
The compiler would generate byte swizzles or not, depending on whether
the native execution mode agrees with the indicated storage class.

or you could always look at the gokhale/minnich paper from 1993 (SEDMS) in
which we built a compiler that did just that, conforming to the IEEE
1596.5 standard (which I helped get going along with David James). It's 
not that hard.

We did a bit more than that, maybe too much more, but still ...

I still think it's a good idea :-)

ron