On Wed, 25 Nov 2020 11:09:05 GMT, Per Liden <pli...@openjdk.org> wrote:
>> JDK-8188055 added the function Reference.refersTo. For performance, the >> supporting native methods Reference.refersTo0 and PhantomReference.refersTo0 >> should be intrinsified by C2. >> >> Initial patch was prepared by @fisk. >> >> Tested hs-tier1-4. Added new compiler tests to test intrinsics. >> >> Ran new test with Shenandoah. Found only one issue. As result I disable >> PhantomReference::refersTo intrinsic for COOP+ Shenandoah combination. >> Someone from Shenandoah team have to test changes if that is enough. > > ZGC changes look good! > I just pulled the fresh master, applied this patch on top, enabled > `_PhantomReference_refersTo0` in `c2compiler.cpp`, and ran > `CONF=linux-x86_64-server-fastdebug make images run-test TEST=tier1 > TEST_VM_OPTS="-XX:+UseShenandoahGC"` without problems. > > @vnkozlov, what Shenandoah failure did you see? Attention @rkennke. @shipilev 2 new tests added by JDK-8188055 does not trigger C2 compilation. You need to run my new test to trigger problem I see: java -Xbatch -XX:-TieredCompilation -XX:CICompilerCount=1 -XX:+UseShenandoahGC TestReferenceRefersTo.java # Internal Error (/open/src/hotspot/share/gc/shenandoah/c2/shenandoahSupport.cpp:999), pid=2498681, tid=2498694 # assert(!is_narrow) failed: phantom access cannot be narrow # # JRE version: Java(TM) SE Runtime Environment (16.0) (fastdebug build 16-internal+0-2020-11-24) # Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 16-internal+0-2020-11-24, mixed mode, sharing, compressed oops, shenandoah gc, linux-amd64) # Problematic frame: # V [libjvm.so+0x1862090] ShenandoahBarrierC2Support::call_lrb_stub(Node*&, Node*&, Node*, Node*&, Node*, unsigned long, PhaseIdealLoop*)+0x7e0 ------------- PR: https://git.openjdk.java.net/jdk/pull/1425
