A.5.253 PSHUFLW: Shuffle Packed Low Words
PSHUFLW xmm1,xmm2/m128,imm8 ; F2 0F 70 /r ib [WILLAMETTE,SSE2]
PSHUFLW shuffles the words in the low quadword of the source (second)
operand according to the encoding specified by imm8, and stores the
result in the low quadword of the destination (first) operand.
The operation of this instruction is similar to the PSHUFW instruction,
except that the source and destination are the low quadword of a 128-bit
operand, instead of being 64-bit operands. The high quadword is copied
from the source to the destination without any changes.