Comment by pbsd

An old version of binutils [1] explains what DDS means:

    How to encode VEX.vvvv:
    0: VEX.vvvv must be 1111b.
    1: VEX.NDS.  Register-only source is encoded in VEX.vvvv where
       the content of source registers will be preserved.
       VEX.DDS.  The second register operand is encoded in VEX.vvvv
       where the content of first source register will be overwritten
       by the result.
       VEX.NDD2.  The second destination register operand is encoded in
       VEX.vvvv for instructions with 2 destination register operands.
       For assembler, there are no difference between VEX.NDS, VEX.DDS
       and VEX.NDD2.
    2. VEX.NDD.  Register destination is encoded in VEX.vvvv for
    instructions with 1 destination register operand.
    3. VEX.LWP.  Register destination is encoded in VEX.vvvv and one
       of the operands can access a memory location.

[1] https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff;...