The following test failed in the JDK16 CI:

applications/microbenchmarks/other/Test_2.java#id15

Here's a snippet from the log file:

[jmh] # JMH version: 1.21
[jmh] # VM version: JDK 16-ea, Java HotSpot(TM) 64-Bit Server VM, 16-ea+13-504
[jmh] # VM invoker: /System/Volumes/Data/mesos/work_dir/jib-master/install/jdk-16+13-504/macosx-x64-debug.jdk/jdk-16/fastdebug/bin/java
[jmh] # VM options: -XX:+UnlockExperimentalVMOptions -XX:hashCode=5 -XX:MaxRAMPercentage=4 -Djava.io.tmpdir=/System/Volumes/Data/mesos/work_dir/slaves/4076d11c-c6ed-4d07-84c1-4ab8d55cd975-S34176/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/771a6090-ba7a-4361-bb6f-eea99a3698bf/runs/3c9e9390-1c96-4281-b84c-df4e3569498f/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_microbenchmarks_other_Test_2_java/tmp -XX:+CreateCoredumpOnCrash -ea -esa -XX:CompileThreshold=100 -XX:+UnlockExperimentalVMOptions -XX:-TieredCompilation -XX:-DoEscapeAnalysis --add-opens=java.base/java.io=ALL-UNNAMED -Djmh.ignoreLock=true -Djava.io.tmpdir=/System/Volumes/Data/mesos/work_dir/slaves/4076d11c-c6ed-4d07-84c1-4ab8d55cd975-S34176/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/771a6090-ba7a-4361-bb6f-eea99a3698bf/runs/3c9e9390-1c96-4281-b84c-df4e3569498f/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_microbenchmarks_other_Test_2_java/scratch/3
[jmh] # Warmup: 5 iterations, 10 s each
[jmh] # Measurement: 5 iterations, 10 s each
[jmh] # Timeout: 10 min per iteration
[jmh] # Threads: 1 thread, will synchronize iterations
[jmh] # Benchmark mode: Throughput, ops/time
[jmh] # Benchmark: net.openjdk.micro.lang.ObjectHashcodeBench.objectHashCode_5
[jmh] # Run progress: 0.00% complete, ETA 00:01:40
[jmh] # Fork: 1 of 1
[jmh] # Warmup Iteration 1: #
[jmh] # A fatal error has been detected by the Java Runtime Environment:
[jmh] #
[jmh] # SIGSEGV (0xb) at pc=0x0000000103a481c9, pid=36025, tid=25347
[jmh] #
[jmh] # JRE version: Java(TM) SE Runtime Environment (16.0+13) (fastdebug build 16-ea+13-504)
[jmh] # Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 16-ea+13-504, mixed mode, sharing, compressed oops, g1 gc, bsd-amd64)
[jmh] # Problematic frame:
[jmh] # V [libjvm.dylib+0x4481c9] PhaseChaitin::gather_lrg_masks(bool)+0x9e9

Here's the crashing thread's stack:

--------------- T H R E A D ---------------

Current thread (0x00007fcf71013420): JavaThread "C2 CompilerThread1" daemon [_thread_in_native, id=25347, stack(0x000070000b740000,0x000070000b840000)]


Current CompileTask:
C2: 9293 494 ! jdk.internal.loader.BuiltinClassLoader::loadClassOrNull (143 bytes)

Stack: [0x000070000b740000,0x000070000b840000], sp=0x000070000b83c340, free space=1008k
Native frames: (J=compiled Java code, A=aot compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.dylib+0x4481c9] PhaseChaitin::gather_lrg_masks(bool)+0x9e9
V [libjvm.dylib+0x748f28] PhaseCFG::global_code_motion()+0x758
V [libjvm.dylib+0x7492e1] PhaseCFG::do_global_code_motion()+0x41
V [libjvm.dylib+0x5191df] Compile::Code_Gen()+0x24f
V [libjvm.dylib+0x515ec7] Compile::Compile(ciEnv*, ciMethod*, int, bool, bool, bool, bool, DirectiveSet*)+0x14d7
V [libjvm.dylib+0x40b6b0] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x1d0
V [libjvm.dylib+0x532528] CompileBroker::invoke_compiler_on_method(CompileTask*)+0x6c8
V [libjvm.dylib+0x531b6c] CompileBroker::compiler_thread_loop()+0x34c
V [libjvm.dylib+0x10147d6] JavaThread::thread_main_inner()+0x316
V [libjvm.dylib+0x100f967] Thread::call_run()+0x1b7
V [libjvm.dylib+0xdd161f] thread_native_entry(Thread*)+0x15f
C [libsystem_pthread.dylib+0x6109] _pthread_start+0x94
C [libsystem_pthread.dylib+0x1b8b] thread_start+0xf


siginfo: si_signo: 11 (SIGSEGV), si_code: 1 (SEGV_MAPERR), si_addr: 0x00006fcf6830bc08