JDK-8371964 : C2 compilation asserts with "Unexpected load/store size"
  • Type: Bug
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 26
  • Priority: P2
  • Status: In Progress
  • Resolution: Unresolved
  • OS: linux
  • CPU: x86_64
  • Submitted: 2025-11-16
  • Updated: 2025-11-29
The Version table provides details related to the release that this issue/RFE will be addressed.

Unresolved : Release in which this issue/RFE will be addressed.
Resolved: Release in which this issue/RFE has been resolved.
Fixed : Release in which this issue/RFE has been fixed. The release containing this fix may be available for download as an Early Access Release or a General Availability Release.

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JDK 26
26Unresolved
Related Reports
Blocks :  
JDK-8371959 - [REDO] Add CTW to hotspot_compiler testing
Causes :  
JDK-8355574 - Fatal error in abort_verify_int_in_range due to Invalid CastII
Duplicate :  
JDK-8371976 - Test java_base_2.java failed during compilation of class #7294
Description
With applications/ctw/modules/java_base.java and "-ea -esa -XX:CompileThreshold=100 -XX:+UnlockExperimentalVMOptions -server -XX:-TieredCompilation -Djava.awt.headless=true"

First crash:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/opt/mach5/mesos/work_dir/slaves/526fbd26-20de-495c-9a19-a04adc16f7d1-S29062/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/a5373669-a515-4d14-bbab-09fe1d3c48b6/runs/0b0e0ee2-fd73-4f39-9375-ded88fa52412/workspace/open/src/hotspot/share/opto/vectornode.cpp:1148), pid=579901, tid=580580
#  assert(load_sz <= MaxVectorSize) failed: Unexpected load size
#
# JRE version: Java(TM) SE Runtime Environment (26.0+25) (fastdebug build 26-ea+25-2488)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 26-ea+25-2488, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# V  [libjvm.so+0x1c47d67]  LoadVectorMaskedNode::Ideal(PhaseGVN*, bool)+0x5d7
#
# 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/526fbd26-20de-495c-9a19-a04adc16f7d1-S22935/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/d46e11b7-031f-446b-8aca-f34e09eba53c/runs/55a40bd3-7793-408d-9964-4fe6e407e86d/testoutput/test-support/jtreg_open_test_hotspot_jtreg_ctw_2/scratch/0/core.579901)
#
# If you would like to submit a bug report, please visit:
#   https://bugreport.java.com/bugreport/crash.jsp
#

---------------  S U M M A R Y ------------

Command Line: -XX:MaxRAMPercentage=4.16667 -Dtest.boot.jdk=/opt/mach5/mesos/work_dir/jib-master/install/jdk/25/37/bundles/linux-x64/jdk-25_linux-x64_bin.tar.gz/jdk-25 -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/526fbd26-20de-495c-9a19-a04adc16f7d1-S22935/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/d46e11b7-031f-446b-8aca-f34e09eba53c/runs/55a40bd3-7793-408d-9964-4fe6e407e86d/testoutput/test-support/jtreg_open_test_hotspot_jtreg_ctw_2/tmp -ea -esa -XX:CompileThreshold=100 -XX:+UnlockExperimentalVMOptions -XX:+TieredCompilation -Djava.awt.headless=true -Xbatch -XX:-ShowMessageBoxOnError -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+DisplayVMOutputToStderr -DCompileTheWorldStartAt=3705 -DCompileTheWorldStopAt=7410 -XX:+WhiteBoxAPI -Xbootclasspath/a:. --add-exports=java.base/jdk.internal.jimage=ALL-UNNAMED --add-exports=java.base/jdk.internal.misc=ALL-UNNAMED --add-exports=java.base/jdk.internal.reflect=ALL-UNNAMED --add-exports=java.base/jdk.internal.access=ALL-UNNAMED -Djava.awt.headless=true -XX:+LogCompilation -XX:LogFile=hotspot_modules_java_base_3705_%p.log -XX:ErrorFile=hs_err_modules_java_base_3705_%p.log -XX:ReplayDataFile=replay_modules_java_base_3705_%p.log -XX:CompileCommand=exclude,java/lang/invoke/MethodHandle.* -XX:PerMethodTrapLimit=0 -XX:PerMethodSpecTrapLimit=0 -XX:-StackTraceInThrowable -XX:+IgnoreUnrecognizedVMOptions -XX:-VerifyInlineCaches -XX:-ZapUnusedHeapArea -XX:+StressLCM -XX:+StressGCM -XX:+StressIGVN -XX:+StressCCP -XX:+StressMacroExpansion -XX:+StressMacroElimination -XX:+StressIncrementalInlining -XX:StressSeed=1932887801 -XX:CompileCommand=memlimit,*.*,0 -XX:+StressBailout -XX:StressBailoutMean=100000 -XX:+CaptureBailoutInformation sun.hotspot.tools.ctw.CompileTheWorld modules:java.base

Host: Intel(R) Xeon(R) Platinum 8358 CPU @ 2.60GHz, 12 cores, 23G, Oracle Linux Server release 9.6
Time: Sat Nov 15 14:44:18 2025 UTC elapsed time: 246.188307 seconds (0d 0h 4m 6s)

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

Current thread (0x00007f8070381170):  JavaThread "C2 CompilerThread1" daemon [_thread_in_native, id=580580, stack(0x00007f809c6e8000,0x00007f809c7e8000) (1024K)]


Current CompileTask:
C2:246188 106241    b  4       sun.text.CompactByteArray::compact (259 bytes)

Stack: [0x00007f809c6e8000,0x00007f809c7e8000],  sp=0x00007f809c7e2f60,  free space=1003k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x1c47d67]  LoadVectorMaskedNode::Ideal(PhaseGVN*, bool)+0x5d7  (vectornode.cpp:1148)
V  [libjvm.so+0x1886b2d]  PhaseIterGVN::transform_old(Node*)+0xbd  (phaseX.cpp:668)
V  [libjvm.so+0x188b355]  PhaseIterGVN::optimize()+0xc5  (phaseX.cpp:1054)
V  [libjvm.so+0x15ec765]  PhaseMacroExpand::expand_macro_nodes()+0x255  (macro.cpp:2686)
V  [libjvm.so+0xbaced2]  Compile::Optimize()+0xf02  (compile.cpp:2545)
V  [libjvm.so+0xbafe33]  Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0x2023  (compile.cpp:860)
V  [libjvm.so+0x9cb933]  C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x4a3  (c2compiler.cpp:147)
V  [libjvm.so+0xbbf320]  CompileBroker::invoke_compiler_on_method(CompileTask*)+0x780  (compileBroker.cpp:2345)
V  [libjvm.so+0xbc0b80]  CompileBroker::compiler_thread_loop()+0x530  (compileBroker.cpp:1989)
V  [libjvm.so+0x1120e0b]  JavaThread::thread_main_inner()+0x13b  (javaThread.cpp:776)
V  [libjvm.so+0x1b96476]  Thread::call_run()+0xb6  (thread.cpp:242)
V  [libjvm.so+0x17f4af8]  thread_native_entry(Thread*)+0x118  (os_linux.cpp:877)

Second crash:

#
# A fatal error has been detected by the Java Runtime Environment:
#
#  Internal Error (/opt/mach5/mesos/work_dir/slaves/526fbd26-20de-495c-9a19-a04adc16f7d1-S29025/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/dd9b24db-ac73-4d27-8c2e-8b706666efc7/runs/fcc003cf-a308-4292-8ec1-e9a4e188392e/workspace/open/src/hotspot/share/opto/vectornode.cpp:1167), pid=2682549, tid=2682568
#  assert(load_sz <= MaxVectorSize) failed: Unexpected store size
#
# JRE version: Java(TM) SE Runtime Environment (26.0+25) (fastdebug build 26-ea+25-2489)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 26-ea+25-2489, mixed mode, sharing, compressed oops, compressed class ptrs, g1 gc, linux-amd64)
# Problematic frame:
# V  [libjvm.so+0x1c482b1]  StoreVectorMaskedNode::Ideal(PhaseGVN*, bool)+0x511
#
# 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/526fbd26-20de-495c-9a19-a04adc16f7d1-S22939/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/84a82756-330a-4914-b844-88bdf93b267a/runs/dabd7df5-de9e-4e5c-aad6-4b0d179754ca/testoutput/test-support/jtreg_open_test_hotspot_jtreg_ctw_2/scratch/3/core.2682549)
#
# If you would like to submit a bug report, please visit:
#   https://bugreport.java.com/bugreport/crash.jsp
#

---------------  S U M M A R Y ------------

Command Line: -XX:MaxRAMPercentage=4.16667 -Dtest.boot.jdk=/opt/mach5/mesos/work_dir/jib-master/install/jdk/25/37/bundles/linux-x64/jdk-25_linux-x64_bin.tar.gz/jdk-25 -Djava.io.tmpdir=/opt/mach5/mesos/work_dir/slaves/526fbd26-20de-495c-9a19-a04adc16f7d1-S22939/frameworks/1735e8a2-a1db-478c-8104-60c8b0af87dd-0196/executors/84a82756-330a-4914-b844-88bdf93b267a/runs/dabd7df5-de9e-4e5c-aad6-4b0d179754ca/testoutput/test-support/jtreg_open_test_hotspot_jtreg_ctw_2/tmp -ea -esa -XX:CompileThreshold=100 -XX:+UnlockExperimentalVMOptions -XX:-TieredCompilation -Djava.awt.headless=true -Xbatch -XX:-ShowMessageBoxOnError -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+DisplayVMOutputToStderr -DCompileTheWorldStartAt=3705 -DCompileTheWorldStopAt=7410 -XX:+WhiteBoxAPI -Xbootclasspath/a:. --add-exports=java.base/jdk.internal.jimage=ALL-UNNAMED --add-exports=java.base/jdk.internal.misc=ALL-UNNAMED --add-exports=java.base/jdk.internal.reflect=ALL-UNNAMED --add-exports=java.base/jdk.internal.access=ALL-UNNAMED -Djava.awt.headless=true -XX:+LogCompilation -XX:LogFile=hotspot_modules_java_base_3705_%p.log -XX:ErrorFile=hs_err_modules_java_base_3705_%p.log -XX:ReplayDataFile=replay_modules_java_base_3705_%p.log -XX:CompileCommand=exclude,java/lang/invoke/MethodHandle.* -XX:PerMethodTrapLimit=0 -XX:PerMethodSpecTrapLimit=0 -XX:-StackTraceInThrowable -XX:+IgnoreUnrecognizedVMOptions -XX:-VerifyInlineCaches -XX:-ZapUnusedHeapArea -XX:+StressLCM -XX:+StressGCM -XX:+StressIGVN -XX:+StressCCP -XX:+StressMacroExpansion -XX:+StressMacroElimination -XX:+StressIncrementalInlining -XX:StressSeed=1603135697 -XX:CompileCommand=memlimit,*.*,0 sun.hotspot.tools.ctw.CompileTheWorld modules:java.base

Host: Intel(R) Xeon(R) Platinum 8358 CPU @ 2.60GHz, 12 cores, 23G, Oracle Linux Server release 9.6
Time: Sun Nov 16 12:11:08 2025 UTC elapsed time: 166.959914 seconds (0d 0h 2m 46s)

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

Current thread (0x00007fd6201522f0):  JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=2682568, stack(0x00007fd6051f3000,0x00007fd6052f3000) (1024K)]


Current CompileTask:
C2:166959 26958    b        sun.text.UCompactIntArray::initPlane (130 bytes)

Stack: [0x00007fd6051f3000,0x00007fd6052f3000],  sp=0x00007fd6052edf60,  free space=1003k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V  [libjvm.so+0x1c482b1]  StoreVectorMaskedNode::Ideal(PhaseGVN*, bool)+0x511  (vectornode.cpp:1167)
V  [libjvm.so+0x1886b2d]  PhaseIterGVN::transform_old(Node*)+0xbd  (phaseX.cpp:668)
V  [libjvm.so+0x188b355]  PhaseIterGVN::optimize()+0xc5  (phaseX.cpp:1054)
V  [libjvm.so+0x15ec765]  PhaseMacroExpand::expand_macro_nodes()+0x255  (macro.cpp:2686)
V  [libjvm.so+0xbaced2]  Compile::Optimize()+0xf02  (compile.cpp:2545)
V  [libjvm.so+0xbafe33]  Compile::Compile(ciEnv*, ciMethod*, int, Options, DirectiveSet*)+0x2023  (compile.cpp:860)
V  [libjvm.so+0x9cb933]  C2Compiler::compile_method(ciEnv*, ciMethod*, int, bool, DirectiveSet*)+0x4a3  (c2compiler.cpp:147)
V  [libjvm.so+0xbbf320]  CompileBroker::invoke_compiler_on_method(CompileTask*)+0x780  (compileBroker.cpp:2345)
V  [libjvm.so+0xbc0b80]  CompileBroker::compiler_thread_loop()+0x530  (compileBroker.cpp:1989)
V  [libjvm.so+0x1120e0b]  JavaThread::thread_main_inner()+0x13b  (javaThread.cpp:776)
V  [libjvm.so+0x1b96476]  Thread::call_run()+0xb6  (thread.cpp:242)
V  [libjvm.so+0x17f4af8]  thread_native_entry(Thread*)+0x118  (os_linux.cpp:877)

Started failing when JDK-8355574 was integrated
Comments
So far 6 occurrences of this failure in our CI , all on x86_64 (Windows and Linux). First one was observed 16th November 2025 .
21-11-2025
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk/pull/28410 Date: 2025-11-20 08:42:46 +0000
20-11-2025
Same on our side. [~qamai] any timeframe for a fix?
20-11-2025
Seeing lots of failures in testing due to this. Is there a fix in sight? Otherwise I am thinking we should backout JDK-8355574 and re-do it.
20-11-2025
Also seen with compiler/arraycopy/TestArrayCopyConjoint.java
19-11-2025
We have numerous ctw failures due to this issue. Over 50 cases linked so far but not all in the CI.
18-11-2025
Also triggers with "compiler/arraycopy/TestArrayCopyDisjoint.java" and "-XX:+UnlockDiagnosticVMOptions -XX:-TieredCompilation -XX:+StressArrayCopyMacroNode -XX:+StressLCM -XX:+StressGCM -XX:+StressIGVN -XX:+StressCCP -XX:+StressMacroExpansion -XX:+StressMethodHandleLinkerInlining -XX:+StressCompiledExceptionHandlers -XX:VerifyConstraintCasts=1 -XX:+StressLoopPeeling"
17-11-2025
ILW = Assert during C2 compilation, with CTW and a few other tests, disable compilation or arraycopy (?) optimizations = HMM = P2
17-11-2025
[~qamai], could you please have a look?
17-11-2025