In this tutorial we'll finish up looking at MMX. We'll examine how to get the remaining comparison operations from the "PCMPGT" and "PCMPEQ" to that are supplied.
This stuff is convoluted but the gist is pretty simple: we make the remaining comparison operations by thinking about what they mean in terms of PCMPEQ, PCMPGT and the boolean operations. "Less than" for example means "Not greater than or equal to". If we find "PCMPGT" we boolean OR this with "PCMPEQ" using the POR instructions and we compliment the results (using a trick) we'll have less than!