NASM 2.05 based x86 Instruction Reference[ch322]
A.5.297 SQRTPD: Packed Double-Precision FP Square Root SQRTPD xmm1,xmm2/m128 ; 66 0F 51 /r [WILLAMETTE,SSE2] SQRTPD calculates the square root of the packed double-precision FP value from the source operand, and stores the double-precision results in the destination register.