RFR: Fix dangling write-barrier in acmp

[Roman Kennke]

Ok, how about those?

JDK8u:
http://cr.openjdk.java.net/~rkennke/fix-acmp-jdk8u/
JDK11:
http://cr.openjdk.java.net/~rkennke/fixacmp-jdk11/webrev.01/

Good?

Roman


> On 12/12/18 1:00 PM, Roman Kennke wrote:
>> This is needed to fix the recent failure that we have observed with
>> new-shaped acmp code in jdk8u:
>>
>> http://cr.openjdk.java.net/~rkennke/fixacmp-jdk11/webrev.00/
> 
> This is shared code path, needs to be protected with INCLUDE_SHENANDOAHGC and UseShenandoahGC?
> 
> For example:
> 
> #ifdef INCLUDE_SHENANDOAHGC
>       if (UseShenandoahGC && igvn != NULL) {
>         set_req_X(1, lhs, igvn);
>         set_req_X(2, rhs, igvn);
>       } else
> #endif
>       {
>         set_req(1, lhs);
>         set_req(2, rhs);
>       }
> 
> 
>> The webrev is against sh/jdk11, where the code is also missing (but bug
>> hasn't showed up in testing). I intend to push the equivalent patch to
>> sh/jdk8u at the same time.
> 
> Remember, there is no INCLUDE_SHENANDOAHGC macro in 8u.
> 
> -Aleksey
>