x86 Instruction Set Reference

Performs an interleaved unpack of the high double-precision floating-point values from the source operand (second operand) and the destination operand (first operand).

The source operand can be an XMM register or a 128-bit memory location; the destination operand is an XMM register.

When unpacking from a memory operand, an implementation may fetch only the appropriate 64 bits; however, alignment to 16-byte boundary and normal segment checking will still be enforced.

Destination[0..63] = Destination[64..127];
Destination[64..127] = Source[64..127];