How to reproduce:

make test TEST=test/hotspot/jtreg/compiler/loopopts/superword/TestSplitPacks.java JTREG="VM_OPTIONS=-XX:MaxVectorSize=8"

Here lists the snippet of error log:

Standard Output
---------------
TestVM main() called - about to run tests in class compiler.loopopts.superword.TestSplitPacks
For random generator using seed: -3377438348530957962
To re-run test with same seed value please add "-Djdk.test.lib.random.seed=-3377438348530957962" to command line.
#
# A fatal error has been detected by the Java Runtime Environment:
#
# Internal Error (/tmp/jdk-src/src/hotspot/share/opto/vtransform.cpp:53), pid=103068, tid=103091
# assert(++pass_count < 10) failed: ensure we do not have endless loops
#
# JRE version: OpenJDK Runtime Environment (26.0) (fastdebug build 26-internal-git-42b108b445b)
# Java VM: OpenJDK 64-Bit Server VM (fastdebug 26-internal-git-42b108b445b, mixed mode, sharing, tiered, compressed oops, compressed class ptrs, g1 gc, linux-aarch64)
# Problematic frame:
# V [libjvm.so+0x1bb1ae4] VTransformGraph::optimize(VTransform&)+0x1c4
#
# Core dump will be written. Default location: Core dumps may be processed with "/usr/share/apport/apport -p%p -s%s -c%c -d%d -P%P -u%u -g%g -- %E" (or dumping to /tmp/jtwork_rerun/hotspot/scratch/core.103068)
#
Unsupported internal testing APIs have been used.