The EMMS instruction empties the MMX state.
This instruction must be used to clear the MMX state (i.e. empty the floating-point
tag word) at the end of an MMX routine before calling other routines that
can execute floating-point instructions. If a floating-point instruction
loads into one of the registers before it has been reset by the EMMS instruction,
a floating-point stack overflow can occur, which results in an floating-point
exception or incorrect result.