[MLton-user] bug with floating-point division on x86/Mac OS X

[Vesa Karvonen]

Fixed in the SVN: http://mlton.org/pipermail/mlton-commit/2009-May/003108.html .

-Vesa Karvonen

On Sat, May 30, 2009 at 10:31 PM, John Reppy <jhr at cs.uchicago.edu> wrote:
> The code generation for floating-point division is broken in certain
> situations
> on the x86 (Mac OS X).  Here is a small program that demonstrates the bug:
>
>  structure R = Real64 (* or Real32 *)
>
>  fun f (a, b) = let
>        val c = a / b
>        in
>          print(concat[R.toString a, "/", R.toString b, " = ", R.toString c,
> "\n"])
>        end;
>
>  val _ = List.app f [(0.5, 2.0), (0.5, 130.0)];
>
> It prints:
>
>  0.5/2 = 4
>  0.5/130 = 260
>
> when it should print something like
>
>  0.5/2 = 0.25
>  0.5/130 = 0.00384615384615
>
> The MLton version is revision 7103 from svn and I'm running on Mac OS X
> 10.5.7.
> The bug affects both 32 and 64-bit floats.
>
>        - John
>
>
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