; save $1, $2, $3, and other used registers

; load array in $1, load 0 in $1
; next instruction will go into a call to getheight

; getheight($1, $2) -> $3
; $1 is the array
; $2 is the index of the current node we are at
; $3 is the register to return the height in
; set return point to end:

getheight:
  ; if cur node is -1, load 0 into $3 and return

  ; save all other registers (not $1, $2, $3) used below

  ; read array and load index of left node into $2
  ; call getheight
  ; upon returning, $3 now has height of left, save left height in another reg

  ; read array and load index of right node into $2
  ; call getheight
  ; upon returning, $3 now has height of right, save right height in another reg

  ; compare left and right and save the bigger one in one of the reg
  ; add 1 to it

  ; restore all other registers (not $1, $2, $3) saved above
  ; return

end:
  ; restore $1, $2, $3, and other used registers
  ; return