There is no support for instructions from the 3DNow! instruction set used by the
AMD-K6-2 processor. The opcodes must be written with ".byte".

Like with bug report 238, this is the wrong place to report this
bug. Actually, I wouldn't personally call this a bug at all. It's
a missing feature, and given the fact that AMD's '3DNow' is *very*
new, you shouldn't really expect support for it, yet. 

But feel free to volunteer writing the necessary support and submitting
it to the FSF.