NASM 2.05 based x86 Instruction Reference[ch192]

A.5.170 MOVMSKPS: Extract Packed Single-Precision FP Sign Mask MOVMSKPS reg32,xmm ; 0F 50 /r [KATMAI,SSE] MOVMSKPS inserts a 4-bit mask in r32, formed of the most significant bits of each single-precision FP number of the source operand.