[aarch64-port-dev ] JDK 13 AArch64 issues to backport

[Andrew Haley]

On 6/20/19 9:15 AM, Andrew Dinn wrote:
> On 19/06/2019 17:54, Andrew Haley wrote:
> 
> So, modulo one quibble (see below) I agree with your assessment of all
> the bugs slated for backport to both jdk8u and jdk11u. They are not
> critical. However, you omitted to consider the ones which were only for
> one of the two repos.
> 
> The two issues that are to me most egregious are in the set listed only
> for jdk11u:
> 
>>   8215792: AArch64: String.indexOf generates incorrect result
>>   8218966: AArch64: String.compareTo() can read memory after string
> 
> These both produce invalid results with certain long Strings. I think it
> is quite possible for these to turn up in real applications (indeed, one
> was found during Graal testing of text processing). So, I think it is
> important to fix them.

Yes, I agree. We should try to get these into the July release.

> There are two patches to restore lost performance that are also well
> worth considering. The first was for jdk8u only:
> 
>>   8216350: AArch64: monitor unlock fast path not called
> 
> The second is the quibble in the jdk8u/11u set:
> 
>>   8217368: AArch64: C2 recursive stack locking optimisation not triggered
> 
> You are right that this does not imply a correctness issue. However it
> does harm locking performance which may matter a lot to some users. So,
> I would still urge backporting these two performance fixes unless you
> are really concerned to keep the backport set absolutely minimal.

Sure, we should backport these, but they're not critical IMO.

-- 
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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