Re: [commit-cp] [bugs #9895] double to int conversion problem

[Archie Cobbs]

David Gilbert wrote:
> public class DoubleToIntTest {
>     public static void main(String args[]) {
>         double v = Integer.MAX_VALUE + 100000.0;
>         System.out.println((int) v);
>         Double d = new Double(v);
>         System.out.println(d.intValue());
>     }
> }
> 
> With Classpath (fairly recent CVS) running on JamVM 1.1.4 (on SuSE 9.1), I 
> see the following output:
> 
> -2147483648
> -2147483648
> 
> Using Sun's JDK 1.4, the output is:
> 
> 2147483647
> 2147483647

I think this is a VM bug rather than a Classpath bug (JC has the same
bug). It results from doing the jdouble -> jint conversion in C via
a `(jint)d' cast.

JC generates this code (edited)...

    jdouble d2;
    jint i1;

    d2 = _JC_DCONST(0x41, 0xe0, 0x0, 0x30, 0xd3, 0xe0, 0x0, 0x0);
    ...
    i1 = (jint)d2;
    ...

I'm still curious what the solution is though :-)

-Archie

__________________________________________________________________________
Archie Cobbs      *        CTO, Awarix        *      http://www.awarix.com