RFR (S) 8176580: [ppc, s390] CRC32C: wrong checksum result in some cases

[Volker Simonis]

On Tue, Mar 14, 2017 at 7:05 PM, Andrew Haley <aph at redhat.com> wrote:
> On 14/03/17 13:12, Schmidt, Lutz wrote:
>
>> Yes, one might think of running a test suite subset multiple times
>> with different parameters. In this case, -Xint and/or –Xcomp were
>> helpful. Forcing tests to run fully interpreted or fully compiled
>> helps in cases where a certain function, e.g. an intrinsic, is
>> invoked via distinct code paths.
>
> Right, so your patch should include that change to the test suite.
>

Hi Lutz,

I agree with Andrew. We should really fix the tests such that they
check the correctness of the intrinsics.

This may be tricky if all three, the interpreter, the client and the
server compiler use the same intrinsic implementation. You could
either copy the pure Java implementation into the test so that you can
compare the results of the intrinsic operation against it or you can
switch them off in the compilers with
"-XX:DisableIntrinsic=_updateBytesCRC32C
-XX:DisableIntrinsics=_updateDirectByteBufferCRC32C" and compare the
results. Not sure which solution is more practical, but I would be
really scared if we wouldn't have these test.

Regards,
Volker

> Andrew.
>