The following test failed in the JDK20 CI:

applications/dacapo/Dacapo.java

Here's a snippet from the log file:

Stress process main method is started.
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/opt/mach5/mesos/work_dir/slaves/0c72054a-24ab-4dbb-944f-97f9341a1b96-S8371/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/2f2a28d8-0d03-4502-8fef-7e0bc88031a9/runs/e15c09be-8f73-40e4-8ea7-c7cc0e65ace0/workspace/open/src/hotspot/share/opto/gcm.cpp:1423), pid=31698, tid=31735
# assert(false) failed: graph should be schedulable
#
# JRE version: Java(TM) SE Runtime Environment (20.0+11) (fastdebug build 20-ea+11-624)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 20-ea+11-624, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, parallel gc, linux-amd64)
# Problematic frame:
# V [libjvm.so+0xec048a] PhaseCFG::schedule_late(VectorSet&, Node_Stack&)+0xc4a
#
# Core dump will be written. Default location: Core dumps may be processed with "/opt/core.sh %p" (or dumping to /opt/mach5/mesos/work_dir/slaves/0c72054a-24ab-4dbb-944f-97f9341a1b96-S34704/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/14bc29d9-4e75-4eb8-b18d-9f07f8aa6167/runs/c9bb1327-9d72-40b3-9c11-47de7506eccd/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_dacapo_Dacapo_java/scratch/0/core.31698)
#
# JFR recording file will be written. Location: /opt/mach5/mesos/work_dir/slaves/0c72054a-24ab-4dbb-944f-97f9341a1b96-S34704/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/14bc29d9-4e75-4eb8-b18d-9f07f8aa6167/runs/c9bb1327-9d72-40b3-9c11-47de7506eccd/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_dacapo_Dacapo_java/scratch/0/hs_err_pid31698.jfr
#
Unsupported internal testing APIs have been used.

# An error report file with more information is saved as:
# /opt/mach5/mesos/work_dir/slaves/0c72054a-24ab-4dbb-944f-97f9341a1b96-S34704/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/14bc29d9-4e75-4eb8-b18d-9f07f8aa6167/runs/c9bb1327-9d72-40b3-9c11-47de7506eccd/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_dacapo_Dacapo_java/scratch/0/hs_err_pid31698.log
#
# Compiler replay data is saved as:
# /opt/mach5/mesos/work_dir/slaves/0c72054a-24ab-4dbb-944f-97f9341a1b96-S34704/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/14bc29d9-4e75-4eb8-b18d-9f07f8aa6167/runs/c9bb1327-9d72-40b3-9c11-47de7506eccd/testoutput/test-support/jtreg_closed_test_hotspot_jtreg_applications_dacapo_Dacapo_java/scratch/0/replay_pid31698.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
----------System.err:(146/18498)----------


Here's the crashing thread's stack:

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

Current thread (0x00007f1e601fbbd0): JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=31735, stack(0x00007f1e22b27000,0x00007f1e22c28000)]


Current CompileTask:
C2: 524483 62814 4 org.h2.index.BaseIndex::getCreateSQL (13 bytes)

Stack: [0x00007f1e22b27000,0x00007f1e22c28000], sp=0x00007f1e22c229a0, free space=1006k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [libjvm.so+0xec048a] PhaseCFG::schedule_late(VectorSet&, Node_Stack&)+0xc4a
V [libjvm.so+0xec0d66] PhaseCFG::global_code_motion()+0x366
V [libjvm.so+0xec4b71] PhaseCFG::do_global_code_motion()+0x51
V [libjvm.so+0xaeac65] Compile::Code_Gen()+0x285
V [libjvm.so+0xaf03c6] Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0x1686
V [libjvm.so+0x901685] C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x675
V [libjvm.so+0xaff097] CompileBroker::invoke_compiler_on_method(CompileTask*)+0xb77
V [libjvm.so+0xafffa0] CompileBroker::compiler_thread_loop()+0x650
V [libjvm.so+0x106427c] JavaThread::thread_main_inner()+0x22c
V [libjvm.so+0x1a6e4e0] Thread::call_run()+0x100
V [libjvm.so+0x17384f3] thread_native_entry(Thread*)+0x103