RFR (XS): 8191915: JCK tests produce incorrect results with C2
aph at redhat.com
Wed Jan 10 15:27:36 UTC 2018
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.
> 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.
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
More information about the hotspot-compiler-dev