invo_context

    OpenVMS usage: invo_context_blk
    type:          structure
    access:        read
    mechanism:     by reference

    Address of a valid invocation context block.

 index

    OpenVMS usage: index
    type:          longword
    access:        read
    mechanism:     by value

    Index into the register array of the XSAVE area pointed to from
    the invocation context block.

 zmm_copy

    OpenVMS usage: SSE register contents
    type:          64 bytes
    access:        write
    mechanism:     by reference

    Address of a 64-byte buffer to receive the contents of the
    specified register.