Original bug ID: 5262
Reporter: edmcman
Assigned to: @xclerc
Status: closed (set by @xavierleroy on 2012-09-25T18:06:17Z)
Resolution: fixed
Priority: normal
Severity: minor
Version: 3.12.0
Fixed in version: 3.12.1+dev
Category: ~DO NOT USE (was: OCaml general)

Bug description

Taking a small, positive integer < 2^n and shifting it to the right by n bits should result in 0. When using Big_ints, the resulting value v has the following properties: (string_of_big_int v) = "0" but (eq_big_int v zero_big_int) = false.

See the sample program:

open Big_int

let x = big_int_of_int 12;;
let sign = shift_right_big_int x 31;;

Printf.printf "sign: %s; sign==0: %b\n" (string_of_big_int sign) (eq_big_int sign zero_big_int);;

For me, this program displays: sign: 0; sign==0: false

I expect it to display: sign: 0; sign==0: true