A.5.204 PAVEB: MMX Packed Average
PAVEB mmxreg,r/m64 ; 0F 50 /r [CYRIX,MMX]
PAVEB, specific to the Cyrix MMX extensions, treats its two operands
as vectors of eight unsigned bytes, and calculates the average of the
corresponding bytes in the operands. The resulting vector of eight
averages is stored in the first operand.
This opcode maps to MOVMSKPS r32, xmm on processors that support the SSE
instruction set.