The following tests failed in the JDK18 CI:

jdk/incubator/vector/ShortMaxVectorTests.java
jdk/incubator/vector/Short64VectorTests.java
jdk/incubator/vector/Short512VectorTests.java
jdk/incubator/vector/Short256VectorTests.java
jdk/incubator/vector/Short128VectorTests.java
jdk/incubator/vector/LongMaxVectorTests.java
jdk/incubator/vector/Long512VectorTests.java
jdk/incubator/vector/Long256VectorTests.java
jdk/incubator/vector/IntMaxVectorTests.java
jdk/incubator/vector/Int512VectorTests.java
jdk/incubator/vector/Int256VectorTests.java
jdk/incubator/vector/Int128VectorTests.java

Here's a snippet from the ShortMaxVectorTests.java log file:

test ShortMaxVectorTests.ASHRShortMaxVectorTests(short[-i * 5], short[i * 5]): success
test ShortMaxVectorTests.ASHRShortMaxVectorTests(short[-i * 5], short[i + 1]): success
test ShortMaxVectorTests.ASHRShortMaxVectorTests(short[-i * 5], short[cornerCaseValue(i)]): success
#
# A fatal error has been detected by the Java Runtime Environment:
#
# EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x00007ff83675f0ba, pid=7380, tid=45900
#
# JRE version: Java(TM) SE Runtime Environment (18.0+24) (fastdebug build 18-ea+24-1585)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (fastdebug 18-ea+24-1585, compiled mode, sharing, compressed oops, compressed class ptrs, g1 gc, windows-amd64)
# Problematic frame:
# V [jvm.dll+0xdf0ba] vrshift_reg_maskedNode::emit+0x16a
#
# Core dump will be written. Default location: T:\\testoutput\\test-support\\jtreg_open_test_jdk_jdk_incubator_vector\\scratch\\0\\hs_err_pid7380.mdmp
#
# An error report file with more information is saved as:
# T:\\testoutput\\test-support\\jtreg_open_test_jdk_jdk_incubator_vector\\scratch\\0\\hs_err_pid7380.log
#
# Compiler replay data is saved as:
# T:\\testoutput\\test-support\\jtreg_open_test_jdk_jdk_incubator_vector\\scratch\\0\\replay_pid7380.log
#
# If you would like to submit a bug report, please visit:
# https://bugreport.java.com/bugreport/crash.jsp
#
----------System.err:(1/56)----------

Here's the crashing thread's stack:

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

Current thread (0x000001d16e6e2340): JavaThread "C2 CompilerThread0" daemon [_thread_in_native, id=45900, stack(0x00000082ff700000,0x00000082ff800000)]


Current CompileTask:
C2: 46159 7073 b ShortMaxVectorTests::ASHRShortMaxVectorTestsMasked (189 bytes)

Stack: [0x00000082ff700000,0x00000082ff800000], sp=0x00000082ff7faf30, free space=1003k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
V [jvm.dll+0xdf0ba] vrshift_reg_maskedNode::emit+0x16a (ad_x86.cpp:38221)
V [jvm.dll+0xbba91b] PhaseOutput::scratch_emit_size+0x26b (output.cpp:3348)
V [jvm.dll+0xbbaeb5] PhaseOutput::shorten_branches+0x435 (output.cpp:612)
V [jvm.dll+0xbb4589] PhaseOutput::Output+0x859 (output.cpp:413)
V [jvm.dll+0x4e5080] Compile::Code_Gen+0x380 (compile.cpp:2781)
V [jvm.dll+0x4e3d8f] Compile::Compile+0x162f (compile.cpp:830)
V [jvm.dll+0x4076b1] C2Compiler::compile_method+0x131 (c2compiler.cpp:111)
V [jvm.dll+0x4fcc06] CompileBroker::invoke_compiler_on_method+0x756 (compileBroker.cpp:2290)
V [jvm.dll+0x4fa3fd] CompileBroker::compiler_thread_loop+0x26d (compileBroker.cpp:1966)
V [jvm.dll+0xd6b817] JavaThread::thread_main_inner+0x297 (thread.cpp:1298)
V [jvm.dll+0xd61174] Thread::call_run+0x1b4 (thread.cpp:363)
V [jvm.dll+0xbab26e] thread_native_entry+0xae (os_windows.cpp:544)
C [ucrtbase.dll+0x26b4c]
C [KERNEL32.DLL+0x14ed0]
C [ntdll.dll+0x7e39b]


siginfo: EXCEPTION_ACCESS_VIOLATION (0xc0000005), reading address 0x0000000000000000