RFR (XS): 8191915: JCK tests produce incorrect results with C2

[Rickard Bäckman]

Added a few comments. I still think I need a second reviewer to OK this.

http://cr.openjdk.java.net/~rbackman/8191915.3/

/R

On 01/11, Tobias Hartmann wrote:
> Hi Rickard,
> 
> On 11.01.2018 10:30, Rickard Bäckman wrote:
> > http://cr.openjdk.java.net/~rbackman/8191915.2/
> 
> Looks correct to me. Maybe add a comment explaining all the casting.
> 
> Best regards,
> Tobias
> 
> 
> > On 01/10, Andrew Haley wrote:
> >> On 10/01/18 14:17, Rickard Bäckman wrote:
> >>> I did the multiply as unsigned and then cast to to signed thing.
> >>> Renamed the test to LongMulOverflowTest.
> >>>
> >>> Updated.
> >>>
> >>> http://cr.openjdk.java.net/~rbackman/8191915.1/
> >>>
> >>> I agree that the best solution would be to use compiler builtins but I'm
> >>> not sure all the compilers support them and makes portability a pain.
> >>
> >> It's still wrong because
> >>
> >>     jlong ax = (val1 < 0 ? -val1 : val1);
> >>     jlong ay = (val2 < 0 ? -val2 : val2);
> >>
> >> is undefined when val1 or val2 is Long.MIN_VALUE.
> >>
> >> -- 
> >> Andrew Haley
> >> Java Platform Lead Engineer
> >> Red Hat UK Ltd. <https://www.redhat.com>
> >> EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
> > /R
> >