Original bug ID: 834
Reporter: administrator
Status: closed
Resolution: not a bug
Priority: normal
Severity: minor
Category: ~DO NOT USE (was: OCaml general)

Bug description

Hello,

[Ocaml v3.04, Linux 2.4.2]

I've attached below a program that terminates abnormally with a
floating point exception if compiled with ocamlopt, but not with
ocamlc. Maybe I'm doing something wrong, but I can't find the
problem easily since it is not there in the byte-compiled version
so I can't use the debugger. Anyway, I suspect that since the
behavior is different between ocamlopt/ocamlc, then it may indeed
be a bug, so I'm submitting it for your consideration. Thanks.

cheers,
doug

(*
flt.pt.exc.ml

This causes a floating point exception:

ocamlopt flt.pt.exc.ml && ./a.out
i = 2
i = 3
Floating point exception (core dumped)

But if compiled with ocamlc the program runs to completion:

ocamlc flt.pt.exc.ml && ./a.out
i = 2
i = 3
i = 4

*)

let _ =
let ops = [| ( / ); ( * ) |] in
let tab = Hashtbl.create 1000 in
let put op x y =
try (let k = op x y in
try Hashtbl.find tab k with Not_found -> Hashtbl.add tab k ())
with Division_by_zero -> () in
let puts op x y = put op x y; put op (-x) y; put op x (-y) in
Hashtbl.add tab 9 ();
for i = 2 to 4 do
prerr_endline (Printf.sprintf "i = %d" i);
Hashtbl.iter (fun n _ -> Array.iter (fun op -> puts op 9 n) ops) tab
done;