Original bug ID: 2019
Reporter: administrator
Status: closed
Resolution: fixed
Priority: normal
Severity: minor
Category: ~DO NOT USE (was: OCaml general)

Bug description

Full_Name: Aleksey Nogin
Version: 3.07+12 (2004-01-03) from CVS
OS: Fedora Core Development
Submission from: charter-242-037.caltech.edu (131.215.242.37)

Summary: It seems that on AMD64 the input_binary_int function is capable of
reading an integer that's different from what was passed to output_binary_int.

One would expect that teh following code:

let f = open_out_bin "/tmp/foo";;
output_binary_int f i;;
close_out f;;
let f = open_in_bin "/tmp/foo";;
let i' = input_binary_int f;;
close_in f;;
i' = i;;

Would output "true" for any int i. However this is not the case on AMD64:

matrix41:~> ocaml
Objective Caml version 3.07+12 (2004-01-03)

let i = 0x89ac12bd;;

val i : int = 2309755581

let f = open_out_bin "/tmp/foo";;

val f : out_channel =

output_binary_int f i;;

• : unit = ()

close_out f;;

• : unit = ()

let f = open_in_bin "/tmp/foo";;

val f : in_channel =

let i' = input_binary_int f;;

val i' : int = -1985211715

close_in f;;

• : unit = ()

i' == i;;

• : bool = false

i' = i;;

• : bool = false

while the same thing works "correctly" on a 32-bit machine - at least with
3.06:

    Objective Caml version 3.06

let i = 0x89ac12bd;;

val i : int = 162271933

let f = open_out_bin "/tmp/foo";;

val f : out_channel =

output_binary_int f i;;

• : unit = ()

close_out f;;

• : unit = ()

let f = open_in_bin "/tmp/foo";;

val f : in_channel =

let i' = input_binary_int f;;

val i' : int = 162271933

close_in f;;

• : unit = ()

i' = i;;

• : bool = true

On another 32-bit machine:

   Objective Caml version 3.07+7 (2003-12-17)

let i = 0x89ac12bd;;

Integer literal exceeds the range of representable integers of type int

Which is IMO pretty reasonable.