public class TestPredicate {
    static class A {
        int i;
    }

    static class B extends A {
    }

    static boolean crash = false;

    static boolean m2() {
        return crash;
    }

    static int m3(float[] arr) {
        return 0;
    }

    static float m1(A aa) {
        float res = 0;
        float[] arr = new float[10];
        for (int i = 0; i < 10; i++) {
            if (m2()) {
                arr = null;
            }
            m3(arr);
            int j = arr.length;
            int k = 0;
            for (k = 9; k < j; k++) {
            }
            if (k == 10) {
                if (aa instanceof B) {
                }
            }
            res += arr[0];
            res += arr[1];
        }
        return res;
    }

    static public void main(String args[]) {
        A a = new A();
        B b = new B();
        for (int i = 0; i < 20000; i++) {
            m1(a);
        }
        crash = true;
        m1(a);
    }
}


ran with:
java -XX:CompileOnly=TestPredicate.m1 -Xcomp TestPredicate
crashes with -XX:+StressGCM (but not with recent builds) or apply following patch:

diff --git a/src/share/vm/opto/gcm.cpp b/src/share/vm/opto/gcm.cpp
--- a/src/share/vm/opto/gcm.cpp
+++ b/src/share/vm/opto/gcm.cpp
@@ -1068,6 +1068,7 @@
 #endif
     cand_cnt++;
     if (LCA_freq < least_freq || // Better Frequency
+ (UseNewCode2 && mach && mach->ideal_Opcode() == Op_AddF) ||
         (StressGCM && Compile::randomized_select(cand_cnt)) || // Should be randomly accepted in stress mode
          (!StressGCM && // Otherwise, choose with latency
           !in_latency && // No block containing latency

and run with -XX:+UseNewCode2

Array accesses are not longer dependent on their null check.

ILW = H (could crash) L (have to use stress options to trigger the crash) M (disable compilation of method or disable predicates) = P3