Attached sample tests, reference output -

$ ..../jdk15b27-1305/jdk-15/fastdebug/bin/javac *.java
$ ..../jdk15b27-1305/jdk-15/fastdebug/bin/java -Xmx4G -Xcomp -Xbatch -XX:+UnlockExperimentalVMOptions -XX:+EnableJVMCI -XX:+UseJVMCICompiler -Djvmci.Compiler=graal -XX:CompileOnly=Test -ea -esa -XX:CompilationMode=high-only-quick-internal Test > TestJDK15b27-1305-Graal.out
$ diff rt_out_ref TestJDK15b27-1305-Graal.out
      10c10
      < byFld sFld Test.lArrFld = -21,-2179,86978320389476000
      ---
      > byFld sFld Test.lArrFld = -21,32635,86978320389476000
      17c17
      < byFld sFld Test.lArrFld = 108,-16341,86978320389476000
      ---
      > byFld sFld Test.lArrFld = 108,13863,86978320389476000
      24c24
      < byFld sFld Test.lArrFld = -19,21209,86978320389476000
      ---
      > byFld sFld Test.lArrFld = -19,28883,86978320389476000
      31c31
      < byFld sFld Test.lArrFld = 110,-12921,86978320389476000
      ---
      > byFld sFld Test.lArrFld = 110,15231,86978320389476000
      38c38
      < byFld sFld Test.lArrFld = -17,9781,86978320389476000
      ---
      > byFld sFld Test.lArrFld = -17,-28117,86978320389476000
      45c45
      < byFld sFld Test.lArrFld = 112,-11037,86978320389476000
      ---
      > byFld sFld Test.lArrFld = 112,-23337,86978320389476000
      52c52
      < byFld sFld Test.lArrFld = -15,19857,86978320389476000
      ---
      > byFld sFld Test.lArrFld = -15,15235,86978320389476000
      59c59
      < byFld sFld Test.lArrFld = 114,-20929,86978320389476000
      ---
      > byFld sFld Test.lArrFld = 114,25135,86978320389476000
      66c66
      < byFld sFld Test.lArrFld = -13,-4883,86978320389476000
      ---
      > byFld sFld Test.lArrFld = -13,5339,86978320389476000

No similar failures with C1, C2
$ ..../jdk15b27-1305/jdk-15/fastdebug/bin/java -Xmx1G -Xcomp -Xbatch -XX:-TieredCompilation -XX:CompileOnly=Test Test > TestJDK15b27-1305-C2.out
$ diff rt_out_ref TestJDK15b27-1305-C2.out

$ ..../jdk15b27-1305/jdk-15/fastdebug/bin/java -Xmx1G -Xcomp -Xbatch -XX:TieredStopAtLevel=2 -XX:CompileOnly=Test Test > TestJDK15b27-1305-C1P.out
$ diff rt_out_ref TestJDK15b27-1305-C1P.out

$ ..../jdk15b27-1305/jdk-15/fastdebug/bin/java -Xmx1G -Xcomp -Xbatch -XX:TieredStopAtLevel=1 -XX:CompileOnly=Test Test > TestJDK15b27-1305-C1.out
$ diff rt_out_ref TestJDK15b27-1305-C1.out

Issue started after recent Graal Update (JDK-8243380) in JDK 15-ea+27-1305.