On Wed, 25 Nov 2020 07:58:42 GMT, Aleksey Shipilev <sh...@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. > > src/hotspot/share/opto/c2compiler.cpp line 476: > >> 474: if (UseCompressedOops && UseShenandoahGC) return false; >> 475: #endif >> 476: break; > > Is this intended to disable the intrinsic on all non-64-bit platforms? Is > that only for Shenandoah 64-bit? I wonder if it should just be: > > case vmIntrinsics::_PhantomReference_refersTo0: > if (UseCompressedOops && UseShenandoahGC) return false; > break; Considering `UseCompressedOops` doesn't make much sense in 32-bit mode and is set to `false`, it seems `#ifdef` can be just dropped. ------------- PR: https://git.openjdk.java.net/jdk/pull/1425
