;;;; Signedness, which nothing in the corpus was exercising.
;;;;
;;;; Found by mutation testing: emit.ml chooses ashr vs lshr and slt vs ult
;;;; from the operand's type, and both choices could be hardcoded to one arm
;;;; with the whole suite still green — because no program shifted a negative
;;;; integer right, and none compared an unsigned value above 2^31.
(defn main [] i32
  ;; An arithmetic shift keeps the sign. A logical one on -8 gives a number
  ;; near 2^63, which is the wrong answer that looks like a huge right one.
  (print-i64 (>> (i64 -8) 1)) (newline)      ; -4
  (print-i64 (>> (i64 -1) 40)) (newline)     ; -1, still, however far it goes

  ;; And unsigned stays unsigned: 3000000000 has its top bit set, so a signed
  ;; compare reads it as negative and answers the other way on every operator.
  (let [big (bit-or (<< (u32 1) 31) (u32 1000))]   ; 2^31 + 1000
    (print-line (if (< big (u32 5)) "wrong: signed compare" "big is not small"))
    (print-line (if (> big (u32 5)) "big is large" "wrong: signed compare"))
    ;; The same value through >>, which is logical on an unsigned type: a
    ;; signed shift here would keep the top bit and answer near 2^31 again.
    (print-i64 (i64 (>> big 31))) (newline))  ; 1
  0)