Reading the AMD Volume 4(26568-Rev. 3.20): 128-Bit and 256-Bit Media Instructions Page 23 says:
The first source operand is an XMM register. The second source operand is either an XMM register ora 128-bit memory location.
This has to be wrong. Memory locations in AMD64 are 64-bits in size. Shouldn't it read: The second source operand is either an XMM register or a memory location of the first byte of a 128-bit value.