A.5.226 PFSUBR: Packed Single-Precision FP Reverse Subtract
PFSUBR mm1,mm2/m64 ; 0F 0F /r AA [PENT,3DNOW]
PFSUBR subtracts the single-precision FP values in the destination from
those in the source, and stores the result in the destination operand.
dst[0-31] := src[0-31] - dst[0-31],
dst[32-63] := src[32-63] - dst[32-63].