More on: Small static method marked not entrant, inlining reversed?

[Rémi Forax]

I take a little time to create a simple test case to reproduce a bug
found by Charles Nutter with c2.
see 
http://groups.google.com/group/jvm-languages/browse_thread/thread/6c9e05ecd28fdcd4#

Here is the test case,
There is 3 classes A, B, C that inherit from AbstractFoo that implements 
Foo.
The method test do a virtual call to check() and because
check() is implemented in AbstractFoo we expect that this call should be
de-virtualized then inlined.

c2 fails, foo.check() is compiled as a virtual call :(
With c1, there is no problem, CHA works correctly.

Rémi

------------------------------------------------------------------------------------------------

public class InlineTest {
   interface Foo {
     public boolean check(int generation);
   }

   static class AbstractFoo implements Foo {
     private final int value;

     protected AbstractFoo(int value) {
       this.value = value;
     }

     public boolean check(int generation) {
       return this.getClass().hashCode() - value == generation;
     }
   }

   static class A extends AbstractFoo {
     public A(int value) {
       super(value);
     }
   }
   static class B extends AbstractFoo {
     public B(int value) {
       super(value);
     }
   }
   static class C extends AbstractFoo {
     public C(int value) {
       super(value);
     }
   }

   private static final int CONST = A.class.hashCode();

   private static int count;

   private static void test(Foo foo) {
     if (foo.check(0)) {
         count += 2;
         //System.out.println("foo");
     } else {
         count += 1;
         //System.out.println("bar");
     }
   }

   public static void main(String[] args) {
     Foo[] array = new Foo[100000];
     int threshold = 20000;
     for(int i=0; i<threshold; i++) {
       array[i] = new A(CONST);
     }

     for(int i=threshold; i<array.length; i++) {
       array[i] = (i%2 == 0)? new B(0): new C(CONST);
     }

     for(int i=0; i<array.length; i++) {
       test(array[i]);
     }

     System.out.println(count);
   }
}