This reliably fails on my Graviton 3 instance. I believe only test5a subset fails. I have not investigated this any deeply.

$ CONF=linux-aarch64-server-fastdebug make test TEST=compiler/loopopts/superword/TestSplitPacks.java

Failed IR Rules (1) of Methods (1)
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1) Method "static java.lang.Object[] compiler.loopopts.superword.TestSplitPacks.test5a(short[],short[],short)" - [Failed IR rules: 1]:
   * @IR rule 1: "@compiler.lib.ir_framework.IR(phase={DEFAULT}, applyIfPlatformAnd={}, applyIfCPUFeatureOr={"sse4.1", "true", "asimd", "true"}, counts={"_#V#LOAD_VECTOR_S#_", "_@2", "> 0", "_#V#LOAD_VECTOR_S#_", "_@4", "> 0", "_#V#LOAD_VECTOR_S#_", "_@8", "> 0", "_#V#ADD_VS#_", "_@2", "> 0", "_#V#ADD_VS#_", "_@8", "> 0", "_#V#ADD_VS#_", "_@4", "> 0", "_#STORE_VECTOR#_", "> 0"}, failOn={}, applyIfPlatformOr={}, applyIfPlatform={"64-bit", "true"}, applyIfOr={}, applyIfCPUFeatureAnd={}, applyIf={}, applyIfCPUFeature={}, applyIfAnd={"MaxVectorSize", ">=32", "AlignVector", "false"}, applyIfNot={})"
     > Phase "PrintIdeal":
       - counts: Graph contains wrong number of nodes:
         * Constraint 1: "(\d+(\s){2}(LoadVector.*)+(\s){2}===.*vector[A-Za-z]<S,2>)"
           - Failed comparison: [found] 0 > 0 [given]
           - No nodes matched!
         * Constraint 4: "(\d+(\s){2}(AddVS.*)+(\s){2}===.*vector[A-Za-z]<S,2>)"
           - Failed comparison: [found] 0 > 0 [given]
           - No nodes matched!