Add value type hash logic under Valhalla flag

- Guard zero hashcode check with Valhalla flags.

Signed-off-by: Aditi Srinivas M <Aditi.Srini@ibm.com>

Author: Aditi Srinivas M

jcl/src/java.base/share/classes/java/lang/J9VMInternals.java

@@ -504,20 +504,26 @@ static int fastIdentityHashCode(Object anObject) {
 			if ((ptr & com.ibm.oti.vm.VM.OBJECT_HEADER_HAS_BEEN_MOVED_IN_CLASS) != 0) {
 				int j9class = ptr & com.ibm.oti.vm.VM.J9_JAVA_CLASS_MASK;
 				int hashValue = h.getIntFromObject(anObject, h.getBackfillOffsetFromJ9Class32(j9class));
+/*[IF INLINE-TYPES]*/
 				/* If the hash is 0, it may be a value object and the hash should be calculated. */
-				if (0 != hashValue) {
-					return hashValue;
+				if ((0 == hashValue) && anObject.getClass().isValue()) {
+					return identityHashCode(anObject);
 				}
+/*[ENDIF] INLINE-TYPES */
+				return hashValue;
 			}
 		} else {
 			long ptr = (com.ibm.oti.vm.VM.FJ9OBJECT_SIZE == 4) ? Integer.toUnsignedLong(h.getIntFromObject(anObject, 0L)) : h.getLongFromObject(anObject, 0L);
 			if ((ptr & com.ibm.oti.vm.VM.OBJECT_HEADER_HAS_BEEN_MOVED_IN_CLASS) != 0) {
 				long j9class = ptr & com.ibm.oti.vm.VM.J9_JAVA_CLASS_MASK;
 				int hashValue = h.getIntFromObject(anObject, h.getBackfillOffsetFromJ9Class64(j9class));
+/*[IF INLINE-TYPES]*/
 				/* If the hash is 0, it may be a value object and the hash should be calculated. */
-				if (0 != hashValue) {
-					return hashValue;
+				if ((0 == hashValue) && anObject.getClass().isValue()) {
+					return identityHashCode(anObject);
 				}
+/*[ENDIF] INLINE-TYPES */
+				return hashValue;
 			}
 		}
 		return identityHashCode(anObject);

runtime/gc_glue_java/ObjectModel.hpp

@@ -422,10 +422,12 @@ class GC_ObjectModel : public GC_ObjectModelBase
 			uintptr_t hashOffset = getHashcodeOffset(object);
 			int32_t *hashCodePointer = (int32_t *)((uint8_t *)object + hashOffset);
 			result = *hashCodePointer;
+#if defined(J9VM_OPT_VALHALLA_VALUE_TYPES)
 			if (0 == result) {
 				result = internalConvertObjectToHash(vm, object);
 				*hashCodePointer = result;
 			}
+#endif /* defined(J9VM_OPT_VALHALLA_VALUE_TYPES) */
 		} else {
 			atomicSetObjectFlags(object, 0, OBJECT_HEADER_HAS_BEEN_HASHED_IN_CLASS);
 			result = internalConvertObjectToHash(vm, object);