A.5.299 SQRTSD: Scalar Double-Precision FP Square Root
SQRTSD xmm1,xmm2/m128 ; F2 0F 51 /r [WILLAMETTE,SSE2]
SQRTSD calculates the square root of the low-order double-precision FP
value from the source operand, and stores the double-precision result in
the destination register. The high-quadword remains unchanged.