test/compiler/valhalla/valuetypes/ValueTypeTestBench.java

@@ -2564,10 +2564,49 @@
         Asserts.assertEQ(staticVal3.i, (int)staticVal3.c);
         Asserts.assertEQ(va[0].i, (int)staticVal3.c);
         Asserts.assertEQ(vt.i, (int)staticVal3.c);
     }
 
+    // Test correct handling of __Value merges through PhiNodes
+    @Test()
+    public long test93() throws Throwable {
+        // Create a new value type
+        final MethodHandle dvt = MethodHandleBuilder.loadCode(MethodHandles.lookup(), "createValueType",
+                                     MethodType.methodType(ValueType.forClass(ValueCapableClass1.class).valueClass()),
+                                     CODE -> {
+                                         CODE.
+                                         iconst_1().
+                                         anewarray(ValueType.forClass(ValueCapableClass1.class).valueClass()).
+                                         iconst_0().
+                                         vaload().
+                                         vreturn();
+                                     });
+        // Box the value type
+        final MethodHandle box = MethodHandleBuilder.loadCode(MethodHandles.lookup(), "boxValueType",
+                                     MethodType.methodType(ValueCapableClass1.class, ValueType.forClass(ValueCapableClass1.class).valueClass()),
+                                     CODE -> {
+                                         CODE.
+                                         vload(0).
+                                         vbox(ValueCapableClass1.class).
+                                         areturn();
+                                     });
+        long result = 0;
+        for (int i = 0; i < 10_000; ++i) {
+            // Merge __Value (ValueCapableClass1) from the two GWT branches, box to the VCC and access field
+            MethodHandle gwt = MethodHandles.guardWithTest(MethodHandles.constant(boolean.class, i % 2 == 0), dvt, dvt);
+            ValueCapableClass1 vcc = (ValueCapableClass1) MethodHandles.filterReturnValue(gwt, box).invokeExact();
+            result += vcc.t;
+        }
+        return result;
+    }
+
+    @DontCompile
+    public void test93_verifier(boolean warmup) throws Throwable {
+        long result = test93();
+        Asserts.assertEQ(result, 0L);
+    }
+
     // ========== Test infrastructure ==========
 
     private static final WhiteBox WHITE_BOX = WhiteBox.getWhiteBox();
     private static final int ValueTypePassFieldsAsArgsOn = 0x1;
     private static final int ValueTypePassFieldsAsArgsOff = 0x2;