Following test shows incorrect results with -XX:-TieredCompilation, but works fine with -XX:TieredStopAtLevel=1

IPROMPT>java --add-modules=jdk.incubator.vector -cp . shuffle
WARNING: Using incubator modules: jdk.incubator.vector
[res] 30378688 [time] 35 ms
IPROMPT>java --add-modules=jdk.incubator.vector -XX:TieredStopAtLevel=1 -cp . shuffle
WARNING: Using incubator modules: jdk.incubator.vector
[res] 4096 [time] 1351 ms

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import jdk.incubator.vector.*;

public class shuffle {
   public static int micro(int i) {
      return ShortVector.SPECIES_512.iotaShuffle(i, 1, false)
                                    .toVector()
                                    .reinterpretAsShorts()
                                    .reduceLanes(VectorOperators.ADD);
   }
   public static void main(String [] args) {
      int res = 0;
      for (int i = 0; i < 10000; i++) {
          res += micro(i & 31);
      }
      long t1 = System.currentTimeMillis();
      for (int i = 0; i < 1000000; i++) {
          res += micro(i & 31);
      }
      long t2 = System.currentTimeMillis();
      System.out.println("[res] " + res + " [time] " + (t2-t1) + " ms");
   }
}
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Looks like the problem with the comparison predicate in iotaShuffle inline expander.