That arithmetic shift right implementation is also what I came up with for a video game fantasy architecture that only has logical shift right. (16-bit registers)

    ; asr rd, rs1, rs2   ; rd = signed(rs1) >> rs2

    and rt, rs1, 0x8000  ; isolate sign bit
    lsr rt, rt, rs2      ; shift sign bit to final position
    neg rt, rt           ; sign-extended part of final result
    lsr rd, rs1, rs2     ; base part of final result
    or rd, rd, rt        ; combine both parts

It might be easier to understand broken down this way for anyone who didn't understand the article's one-liner.