Subtracts the low double-precision floating-point value in the source operand (second operand) from the low double-precision floating-point value in the destination operand (first operand), and stores the double-precision floating-point result in the destination operand. The source operand can be an XMM register or a 64-bit memory location. The destination operand is an XMM register. The high quadword of the destination operand remains unchanged. See Figure 11-4 in the IA-32 Intel Architecture Software Developer's Manual, Volume 1 for an illustration of a scalar double-precision floating-point operation.

Destination[0..63] = Destination[0..63] - Source[0..63];
//Destination[64..127] remains unchanged