# HG changeset patch
# User Tom Rodriguez <tom.rodriguez@oracle.com>
# Date 1415062168 28800
# Node ID 06bc22024f371e662c54c8a4c52f3392eb73342f
# Parent  31832ebd40cf45ba15a9708bbddd37d61979f29a# Parent  95b2f8b8250e41c05eda5e4c7ce5e3be8c3c3c8d
Merge

diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/LocationIdentity.java
--- a/graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/LocationIdentity.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/LocationIdentity.java	Mon Nov 03 16:49:28 2014 -0800
@@ -37,12 +37,20 @@
     LocationIdentity ANY_LOCATION = new NamedLocationIdentity("ANY_LOCATION");
 
     /**
-     * Denotes the location of a value that is guaranteed to be final.
+     * Denotes the location of a value that is guaranteed to be unchanging.
      */
-    LocationIdentity FINAL_LOCATION = new NamedLocationIdentity("FINAL_LOCATION");
+    LocationIdentity FINAL_LOCATION = new NamedLocationIdentity("FINAL_LOCATION", true);
 
     /**
      * Denotes the location of the length field of a Java array.
      */
-    LocationIdentity ARRAY_LENGTH_LOCATION = new NamedLocationIdentity("[].length");
+    LocationIdentity ARRAY_LENGTH_LOCATION = new NamedLocationIdentity("[].length", true);
+
+    /**
+     * Denotes a location is unchanging in all cases. Not that this is different than the Java
+     * notion of final which only requires definite assignment.
+     */
+    default boolean isImmutable() {
+        return false;
+    }
 }
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/NamedLocationIdentity.java
--- a/graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/NamedLocationIdentity.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/NamedLocationIdentity.java	Mon Nov 03 16:49:28 2014 -0800
@@ -31,13 +31,26 @@
 
     protected final String name;
 
+    protected final boolean immutable;
+
     /**
      * Creates a named unique location identity for read and write operations.
-     * 
+     *
      * @param name the name of the new location identity
      */
     public NamedLocationIdentity(String name) {
         this.name = name;
+        this.immutable = false;
+    }
+
+    /**
+     * Creates a named unique location identity for read and write operations.
+     *
+     * @param name the name of the new location identity
+     */
+    public NamedLocationIdentity(String name, boolean immutable) {
+        this.name = name;
+        this.immutable = immutable;
     }
 
     @Override
@@ -45,6 +58,10 @@
         return name;
     }
 
+    public boolean isImmutable() {
+        return immutable;
+    }
+
     /**
      * Returns the named location identity for an array of the given element kind. Array accesses of
      * the same kind must have the same location identity unless an alias analysis guarantees that
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.compiler.test/src/com/oracle/graal/compiler/test/ReadAfterCheckCastTest.java
--- a/graal/com.oracle.graal.compiler.test/src/com/oracle/graal/compiler/test/ReadAfterCheckCastTest.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.compiler.test/src/com/oracle/graal/compiler/test/ReadAfterCheckCastTest.java	Mon Nov 03 16:49:28 2014 -0800
@@ -25,7 +25,6 @@
 import org.junit.*;
 
 import com.oracle.graal.api.code.*;
-import com.oracle.graal.api.meta.*;
 import com.oracle.graal.debug.*;
 import com.oracle.graal.debug.Debug.Scope;
 import com.oracle.graal.nodes.*;
@@ -95,7 +94,7 @@
             for (FloatingReadNode node : graph.getNodes(ParameterNode.class).first().usages().filter(FloatingReadNode.class)) {
                 // Checking that the parameter a is not directly used for the access to field
                 // x10 (because x10 must be guarded by the checkcast).
-                Assert.assertTrue(node.location().getLocationIdentity() == LocationIdentity.FINAL_LOCATION);
+                Assert.assertTrue(node.location().getLocationIdentity().isImmutable());
             }
         } catch (Throwable e) {
             throw Debug.handle(e);
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotVMConfig.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotVMConfig.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotVMConfig.java	Mon Nov 03 16:49:28 2014 -0800
@@ -824,7 +824,6 @@
     @HotSpotVMField(name = "Klass::_modifier_flags", type = "jint", get = HotSpotVMField.Type.OFFSET) @Stable public int klassModifierFlagsOffset;
     @HotSpotVMField(name = "Klass::_access_flags", type = "AccessFlags", get = HotSpotVMField.Type.OFFSET) @Stable public int klassAccessFlagsOffset;
     @HotSpotVMField(name = "Klass::_layout_helper", type = "jint", get = HotSpotVMField.Type.OFFSET) @Stable public int klassLayoutHelperOffset;
-    @HotSpotVMField(name = "Klass::_layout_helper", type = "jint", get = HotSpotVMField.Type.OFFSET) @Stable public int klassInstanceSizeOffset;
 
     @HotSpotVMConstant(name = "Klass::_lh_neutral_value") @Stable public int klassLayoutHelperNeutralValue;
     @HotSpotVMConstant(name = "Klass::_lh_instance_slow_path_bit") @Stable public int klassLayoutHelperInstanceSlowPathBit;
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/meta/DefaultHotSpotLoweringProvider.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/meta/DefaultHotSpotLoweringProvider.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/meta/DefaultHotSpotLoweringProvider.java	Mon Nov 03 16:49:28 2014 -0800
@@ -250,7 +250,7 @@
     @Override
     protected ValueNode createReadArrayComponentHub(StructuredGraph graph, ValueNode arrayHub, FixedNode anchor) {
         Kind wordKind = runtime.getTarget().wordKind;
-        LocationNode location = ConstantLocationNode.create(FINAL_LOCATION, wordKind, runtime.getConfig().arrayClassElementOffset, graph);
+        LocationNode location = ConstantLocationNode.create(OBJ_ARRAY_KLASS_ELEMENT_KLASS_LOCATION, wordKind, runtime.getConfig().arrayClassElementOffset, graph);
         /*
          * Anchor the read of the element klass to the cfg, because it is only valid when arrayClass
          * is an object class, which might not be the case in other parts of the compiled method.
@@ -401,7 +401,7 @@
     protected ValueNode createReadHub(StructuredGraph graph, ValueNode object, GuardingNode guard) {
         Kind wordKind = target.wordKind;
         HotSpotVMConfig config = runtime.getConfig();
-        LocationNode location = ConstantLocationNode.create(FINAL_LOCATION, wordKind, config.hubOffset, graph);
+        LocationNode location = ConstantLocationNode.create(HUB_LOCATION, wordKind, config.hubOffset, graph);
         assert !object.isConstant() || object.asJavaConstant().isNull();
 
         Stamp hubStamp;
@@ -421,7 +421,7 @@
 
     private WriteNode createWriteHub(StructuredGraph graph, Kind wordKind, ValueNode object, ValueNode value) {
         HotSpotVMConfig config = runtime.getConfig();
-        LocationNode location = ConstantLocationNode.create(HUB_LOCATION, wordKind, config.hubOffset, graph);
+        LocationNode location = ConstantLocationNode.create(HUB_WRITE_LOCATION, wordKind, config.hubOffset, graph);
         assert !object.isConstant() || object.asJavaConstant().isNull();
 
         ValueNode writeValue = value;
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/phases/LoadJavaMirrorWithKlassPhase.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/phases/LoadJavaMirrorWithKlassPhase.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/phases/LoadJavaMirrorWithKlassPhase.java	Mon Nov 03 16:49:28 2014 -0800
@@ -23,6 +23,7 @@
 package com.oracle.graal.hotspot.phases;
 
 import static com.oracle.graal.api.meta.LocationIdentity.*;
+import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.*;
 import static com.oracle.graal.nodes.ConstantNode.*;
 
 import com.oracle.graal.api.meta.*;
@@ -65,7 +66,7 @@
             JavaConstant klass;
             LocationNode location;
             if (type instanceof HotSpotResolvedObjectType) {
-                location = ConstantLocationNode.create(FINAL_LOCATION, Kind.Object, classMirrorOffset, graph);
+                location = ConstantLocationNode.create(CLASS_MIRROR_LOCATION, Kind.Object, classMirrorOffset, graph);
                 klass = ((HotSpotResolvedObjectType) type).klass();
             } else {
                 /*
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ClassSubstitutions.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ClassSubstitutions.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ClassSubstitutions.java	Mon Nov 03 16:49:28 2014 -0800
@@ -27,7 +27,6 @@
 
 import java.lang.reflect.*;
 
-import com.oracle.graal.api.meta.*;
 import com.oracle.graal.api.replacements.*;
 import com.oracle.graal.hotspot.nodes.*;
 import com.oracle.graal.nodes.calc.*;
@@ -48,7 +47,7 @@
             // Class for primitive type
             return Modifier.ABSTRACT | Modifier.FINAL | Modifier.PUBLIC;
         } else {
-            return klass.readInt(klassModifierFlagsOffset(), LocationIdentity.FINAL_LOCATION);
+            return klass.readInt(klassModifierFlagsOffset(), KLASS_MODIFIER_FLAGS_LOCATION);
         }
     }
 
@@ -59,7 +58,7 @@
         if (klass.equal(0)) {
             return false;
         } else {
-            int accessFlags = klass.readInt(klassAccessFlagsOffset(), LocationIdentity.FINAL_LOCATION);
+            int accessFlags = klass.readInt(klassAccessFlagsOffset(), KLASS_ACCESS_FLAGS_LOCATION);
             return (accessFlags & Modifier.INTERFACE) != 0;
         }
     }
@@ -90,16 +89,16 @@
     public static Class<?> getSuperclass(final Class<?> thisObj) {
         Word klass = loadWordFromObject(thisObj, klassOffset());
         if (klass.notEqual(0)) {
-            int accessFlags = klass.readInt(klassAccessFlagsOffset(), LocationIdentity.FINAL_LOCATION);
+            int accessFlags = klass.readInt(klassAccessFlagsOffset(), KLASS_ACCESS_FLAGS_LOCATION);
             if ((accessFlags & Modifier.INTERFACE) == 0) {
                 if (klassIsArray(klass)) {
                     return Object.class;
                 } else {
-                    Word superKlass = klass.readWord(klassSuperKlassOffset(), LocationIdentity.FINAL_LOCATION);
+                    Word superKlass = klass.readWord(klassSuperKlassOffset(), KLASS_SUPER_KLASS_LOCATION);
                     if (superKlass.equal(0)) {
                         return null;
                     } else {
-                        return piCastExactNonNull(superKlass.readObject(classMirrorOffset(), LocationIdentity.FINAL_LOCATION), Class.class);
+                        return piCastExactNonNull(superKlass.readObject(classMirrorOffset(), CLASS_MIRROR_LOCATION), Class.class);
                     }
                 }
             }
@@ -113,7 +112,7 @@
         Word klass = loadWordFromObject(thisObj, klassOffset());
         if (klass.notEqual(0)) {
             if (klassIsArray(klass)) {
-                return piCastExactNonNull(klass.readObject(arrayKlassComponentMirrorOffset(), LocationIdentity.FINAL_LOCATION), Class.class);
+                return piCastExactNonNull(klass.readObject(arrayKlassComponentMirrorOffset(), ARRAY_KLASS_COMPONENT_MIRROR), Class.class);
             }
         }
         return null;
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/HotSpotReplacementsUtil.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/HotSpotReplacementsUtil.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/HotSpotReplacementsUtil.java	Mon Nov 03 16:49:28 2014 -0800
@@ -232,11 +232,15 @@
         return result;
     }
 
+    public static final LocationIdentity JAVA_THREAD_THREAD_OBJECT_LOCATION = new NamedLocationIdentity("JavaThread::_threadObj");
+
     @Fold
     public static int threadObjectOffset() {
         return config().threadObjectOffset;
     }
 
+    public static final LocationIdentity JAVA_THREAD_OSTHREAD_LOCATION = new NamedLocationIdentity("JavaThread::_osthread");
+
     @Fold
     public static int osThreadOffset() {
         return config().osThreadOffset;
@@ -279,18 +283,22 @@
         return config().arrayPrototypeMarkWord();
     }
 
+    public static final LocationIdentity KLASS_ACCESS_FLAGS_LOCATION = new NamedLocationIdentity("Klass::_access_flags", true);
+
     @Fold
     public static int klassAccessFlagsOffset() {
         return config().klassAccessFlagsOffset;
     }
 
+    public static final LocationIdentity KLASS_LAYOUT_HELPER_LOCATION = new NamedLocationIdentity("Klass::_layout_helper", true);
+
     @Fold
     public static int klassLayoutHelperOffset() {
         return config().klassLayoutHelperOffset;
     }
 
     public static int readLayoutHelper(Word hub) {
-        return hub.readInt(klassLayoutHelperOffset(), LocationIdentity.FINAL_LOCATION);
+        return hub.readInt(klassLayoutHelperOffset(), KLASS_LAYOUT_HELPER_LOCATION);
     }
 
     /**
@@ -311,11 +319,15 @@
         return (layoutHelper < layoutHelperNeutralValue);
     }
 
+    public static final LocationIdentity ARRAY_KLASS_COMPONENT_MIRROR = new NamedLocationIdentity("ArrayKlass::_component_mirror", true);
+
     @Fold
     public static int arrayKlassComponentMirrorOffset() {
         return config().arrayKlassComponentMirrorOffset;
     }
 
+    public static final LocationIdentity KLASS_SUPER_KLASS_LOCATION = new NamedLocationIdentity("Klass::_super", true);
+
     @Fold
     public static int klassSuperKlassOffset() {
         return config().klassSuperKlassOffset;
@@ -328,7 +340,9 @@
         return config().markOffset;
     }
 
-    public static final LocationIdentity HUB_LOCATION = new NamedLocationIdentity("Hub");
+    public static final LocationIdentity HUB_WRITE_LOCATION = new NamedLocationIdentity("Hub");
+
+    public static final LocationIdentity HUB_LOCATION = new NamedLocationIdentity("Hub", true);
 
     @Fold
     private static int hubOffset() {
@@ -465,6 +479,8 @@
         return config().g1SATBQueueBufferOffset();
     }
 
+    public static final LocationIdentity KLASS_SUPER_CHECK_OFFSET_LOCATION = new NamedLocationIdentity("Klass::_super_check_offset", true);
+
     @Fold
     public static int superCheckOffsetOffset() {
         return config().superCheckOffsetOffset;
@@ -607,6 +623,8 @@
         return hub.readByte(instanceKlassInitStateOffset(), CLASS_STATE_LOCATION);
     }
 
+    public static final LocationIdentity KLASS_MODIFIER_FLAGS_LOCATION = new NamedLocationIdentity("Klass::_modifier_flags", true);
+
     @Fold
     public static int klassModifierFlagsOffset() {
         return config().klassModifierFlagsOffset;
@@ -629,16 +647,13 @@
         return config().instanceKlassNodeClassOffset;
     }
 
+    public static final LocationIdentity CLASS_MIRROR_LOCATION = new NamedLocationIdentity("Klass::_java_mirror", true);
+
     @Fold
     public static int classMirrorOffset() {
         return config().classMirrorOffset;
     }
 
-    @Fold
-    public static int klassInstanceSizeOffset() {
-        return config().klassInstanceSizeOffset;
-    }
-
     public static final LocationIdentity HEAP_TOP_LOCATION = new NamedLocationIdentity("HeapTop");
 
     @Fold
@@ -802,4 +817,12 @@
             throw new GraalInternalError(e);
         }
     }
+
+    public static final LocationIdentity OBJ_ARRAY_KLASS_ELEMENT_KLASS_LOCATION = new NamedLocationIdentity("ObjArrayKlass::_element_klass", true);
+
+    public static final LocationIdentity PRIMARY_SUPERS_LOCATION = new NamedLocationIdentity("PrimarySupers", true);
+
+    public static final LocationIdentity METASPACE_ARRAY_LENGTH_LOCATION = new NamedLocationIdentity("MetaspaceArrayLength", true);
+
+    public static final LocationIdentity SECONDARY_SUPERS_ELEMENT_LOCATION = new NamedLocationIdentity("SecondarySupersElement", true);
 }
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/InstanceOfSnippets.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/InstanceOfSnippets.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/InstanceOfSnippets.java	Mon Nov 03 16:49:28 2014 -0800
@@ -141,7 +141,7 @@
         }
         GuardingNode anchorNode = SnippetAnchorNode.anchor();
         Word objectHub = loadHubIntrinsic(object, getWordKind(), anchorNode);
-        if (probability(NOT_LIKELY_PROBABILITY, objectHub.readWord(superCheckOffset, LocationIdentity.FINAL_LOCATION).notEqual(hub))) {
+        if (probability(NOT_LIKELY_PROBABILITY, objectHub.readWord(superCheckOffset, PRIMARY_SUPERS_LOCATION).notEqual(hub))) {
             displayMiss.inc();
             return falseValue;
         }
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ObjectSubstitutions.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ObjectSubstitutions.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ObjectSubstitutions.java	Mon Nov 03 16:49:28 2014 -0800
@@ -25,7 +25,6 @@
 import static com.oracle.graal.hotspot.replacements.HotSpotReplacementsUtil.*;
 import static com.oracle.graal.nodes.PiNode.*;
 
-import com.oracle.graal.api.meta.*;
 import com.oracle.graal.api.replacements.*;
 import com.oracle.graal.nodes.java.*;
 import com.oracle.graal.nodes.spi.*;
@@ -41,7 +40,7 @@
     @MethodSubstitution(isStatic = false, forced = true)
     public static Class<?> getClass(final Object thisObj) {
         Word hub = loadHub(thisObj);
-        return piCastExactNonNull(hub.readObject(Word.signed(classMirrorOffset()), LocationIdentity.FINAL_LOCATION), Class.class);
+        return piCastExactNonNull(hub.readObject(Word.signed(classMirrorOffset()), CLASS_MIRROR_LOCATION), Class.class);
     }
 
     @MethodSubstitution(isStatic = false)
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ThreadSubstitutions.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ThreadSubstitutions.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/ThreadSubstitutions.java	Mon Nov 03 16:49:28 2014 -0800
@@ -45,15 +45,15 @@
 
     @MethodSubstitution
     public static Thread currentThread() {
-        return PiNode.piCastNonNull(CurrentJavaThreadNode.get(getWordKind()).readObject(threadObjectOffset(), LocationIdentity.FINAL_LOCATION), Thread.class);
+        return PiNode.piCastNonNull(CurrentJavaThreadNode.get(getWordKind()).readObject(threadObjectOffset(), JAVA_THREAD_THREAD_OBJECT_LOCATION), Thread.class);
     }
 
     @MethodSubstitution(isStatic = false)
     public static boolean isInterrupted(final Thread thisObject, boolean clearInterrupted) {
         Word javaThread = CurrentJavaThreadNode.get(getWordKind());
-        Object thread = javaThread.readObject(threadObjectOffset(), LocationIdentity.FINAL_LOCATION);
+        Object thread = javaThread.readObject(threadObjectOffset(), JAVA_THREAD_THREAD_OBJECT_LOCATION);
         if (thisObject == thread) {
-            Word osThread = javaThread.readWord(osThreadOffset(), LocationIdentity.FINAL_LOCATION);
+            Word osThread = javaThread.readWord(osThreadOffset(), JAVA_THREAD_OSTHREAD_LOCATION);
             boolean interrupted = osThread.readInt(osThreadInterruptedOffset(), ANY_LOCATION) != 0;
             if (!interrupted || !clearInterrupted) {
                 return interrupted;
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/TypeCheckSnippetUtils.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/TypeCheckSnippetUtils.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/replacements/TypeCheckSnippetUtils.java	Mon Nov 03 16:49:28 2014 -0800
@@ -42,8 +42,6 @@
  */
 public class TypeCheckSnippetUtils {
 
-    public static final LocationIdentity TYPE_DISPLAY_LOCATION = new NamedLocationIdentity("TypeDisplay");
-
     static boolean checkSecondarySubType(Word t, Word s) {
         // if (S.cache == T) return true
         if (s.readWord(secondarySuperCacheOffset(), SECONDARY_SUPER_CACHE_LOCATION).equal(t)) {
@@ -56,11 +54,11 @@
 
     static boolean checkUnknownSubType(Word t, Word s) {
         // int off = T.offset
-        int superCheckOffset = t.readInt(superCheckOffsetOffset(), LocationIdentity.FINAL_LOCATION);
+        int superCheckOffset = t.readInt(superCheckOffsetOffset(), KLASS_SUPER_CHECK_OFFSET_LOCATION);
         boolean primary = superCheckOffset != secondarySuperCacheOffset();
 
         // if (T = S[off]) return true
-        if (s.readWord(superCheckOffset, TYPE_DISPLAY_LOCATION).equal(t)) {
+        if (s.readWord(superCheckOffset, PRIMARY_SUPERS_LOCATION).equal(t)) {
             if (primary) {
                 cacheHit.inc();
             } else {
@@ -87,7 +85,7 @@
 
         // if (S.scan_s_s_array(T)) { S.cache = T; return true; }
         Word secondarySupers = s.readWord(secondarySupersOffset(), SECONDARY_SUPERS_LOCATION);
-        int length = secondarySupers.readInt(metaspaceArrayLengthOffset(), LocationIdentity.FINAL_LOCATION);
+        int length = secondarySupers.readInt(metaspaceArrayLengthOffset(), METASPACE_ARRAY_LENGTH_LOCATION);
         for (int i = 0; i < length; i++) {
             if (probability(NOT_LIKELY_PROBABILITY, t.equal(loadSecondarySupersElement(secondarySupers, i)))) {
                 s.writeWord(secondarySuperCacheOffset(), t, SECONDARY_SUPER_CACHE_LOCATION);
@@ -141,7 +139,7 @@
     }
 
     static Word loadSecondarySupersElement(Word metaspaceArray, int index) {
-        return metaspaceArray.readWord(metaspaceArrayBaseOffset() + index * wordSize(), LocationIdentity.FINAL_LOCATION);
+        return metaspaceArray.readWord(metaspaceArrayBaseOffset() + index * wordSize(), SECONDARY_SUPERS_ELEMENT_LOCATION);
     }
 
     private static final SnippetCounter.Group counters = SnippetCounters.getValue() ? new SnippetCounter.Group("TypeCheck") : null;
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/stubs/NewArrayStub.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/stubs/NewArrayStub.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/stubs/NewArrayStub.java	Mon Nov 03 16:49:28 2014 -0800
@@ -83,7 +83,7 @@
      */
     @Snippet
     private static Object newArray(Word hub, int length, @ConstantParameter Word intArrayHub, @ConstantParameter Register threadRegister) {
-        int layoutHelper = hub.readInt(klassLayoutHelperOffset(), LocationIdentity.FINAL_LOCATION);
+        int layoutHelper = hub.readInt(klassLayoutHelperOffset(), KLASS_LAYOUT_HELPER_LOCATION);
         int log2ElementSize = (layoutHelper >> layoutHelperLog2ElementSizeShift()) & layoutHelperLog2ElementSizeMask();
         int headerSize = (layoutHelper >> layoutHelperHeaderSizeShift()) & layoutHelperHeaderSizeMask();
         int elementKind = (layoutHelper >> layoutHelperElementTypeShift()) & layoutHelperElementTypeMask();
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/stubs/NewInstanceStub.java
--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/stubs/NewInstanceStub.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/stubs/NewInstanceStub.java	Mon Nov 03 16:49:28 2014 -0800
@@ -96,7 +96,11 @@
      */
     @Snippet
     private static Object newInstance(Word hub, @ConstantParameter Word intArrayHub, @ConstantParameter Register threadRegister) {
-        int sizeInBytes = hub.readInt(klassInstanceSizeOffset(), LocationIdentity.FINAL_LOCATION);
+        /*
+         * The type is known to be an instance so Klass::_layout_helper is the instance size as a
+         * raw number
+         */
+        int sizeInBytes = hub.readInt(klassLayoutHelperOffset(), KLASS_LAYOUT_HELPER_LOCATION);
         Word thread = registerAsWord(threadRegister);
         if (!forceSlowPath() && inlineContiguousAllocationSupported()) {
             if (isInstanceKlassFullyInitialized(hub)) {
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/MemoryMapNode.java
--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/MemoryMapNode.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/MemoryMapNode.java	Mon Nov 03 16:49:28 2014 -0800
@@ -73,7 +73,7 @@
     }
 
     public MemoryNode getLastLocationAccess(LocationIdentity locationIdentity) {
-        if (locationIdentity == FINAL_LOCATION) {
+        if (locationIdentity.isImmutable()) {
             return null;
         } else {
             int index = locationIdentities.indexOf(locationIdentity);
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/ReadNode.java
--- a/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/ReadNode.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.nodes/src/com/oracle/graal/nodes/extended/ReadNode.java	Mon Nov 03 16:49:28 2014 -0800
@@ -120,8 +120,7 @@
         MetaAccessProvider metaAccess = tool.getMetaAccess();
         if (tool.canonicalizeReads()) {
             if (metaAccess != null && object != null && object.isConstant()) {
-                if ((location.getLocationIdentity() == LocationIdentity.FINAL_LOCATION || location.getLocationIdentity() == LocationIdentity.ARRAY_LENGTH_LOCATION) &&
-                                location instanceof ConstantLocationNode) {
+                if ((location.getLocationIdentity().isImmutable()) && location instanceof ConstantLocationNode) {
                     long displacement = ((ConstantLocationNode) location).getDisplacement();
                     JavaConstant base = object.asJavaConstant();
                     if (base != null) {
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/FloatingReadPhase.java
--- a/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/FloatingReadPhase.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.phases.common/src/com/oracle/graal/phases/common/FloatingReadPhase.java	Mon Nov 03 16:49:28 2014 -0800
@@ -67,7 +67,7 @@
         @Override
         public MemoryNode getLastLocationAccess(LocationIdentity locationIdentity) {
             MemoryNode lastLocationAccess;
-            if (locationIdentity == FINAL_LOCATION) {
+            if (locationIdentity.isImmutable()) {
                 return null;
             } else {
                 lastLocationAccess = lastMemorySnapshot.get(locationIdentity);
@@ -157,7 +157,7 @@
         for (MemoryMap other : states) {
             keys.addAll(other.getLocations());
         }
-        assert !keys.contains(FINAL_LOCATION);
+        assert checkNoImmutableLocations(keys);
 
         Map<LocationIdentity, MemoryPhiNode> existingPhis = null;
         if (updateExistingPhis) {
@@ -209,6 +209,13 @@
 
     }
 
+    private static boolean checkNoImmutableLocations(Set<LocationIdentity> keys) {
+        keys.forEach(t -> {
+            assert !t.isImmutable();
+        });
+        return true;
+    }
+
     public static class CollectMemoryCheckpointsClosure extends NodeIteratorClosure<Set<LocationIdentity>> {
 
         private final Map<LoopBeginNode, Set<LocationIdentity>> modifiedInLoops;
@@ -254,7 +261,7 @@
                 exit.addAll(modifiedLocations);
                 exit.addAll(initialState);
             }
-            assert !modifiedLocations.contains(FINAL_LOCATION);
+            assert checkNoImmutableLocations(modifiedLocations);
             modifiedInLoops.put(loop, modifiedLocations);
             return loopInfo.exitStates;
         }
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.phases/src/com/oracle/graal/phases/schedule/SchedulePhase.java
--- a/graal/com.oracle.graal.phases/src/com/oracle/graal/phases/schedule/SchedulePhase.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.phases/src/com/oracle/graal/phases/schedule/SchedulePhase.java	Mon Nov 03 16:49:28 2014 -0800
@@ -437,7 +437,7 @@
                 break;
             case LATEST:
             case LATEST_OUT_OF_LOOPS:
-                boolean scheduleRead = memsched == MemoryScheduling.OPTIMAL && node instanceof FloatingReadNode && ((FloatingReadNode) node).location().getLocationIdentity() != FINAL_LOCATION;
+                boolean scheduleRead = memsched == MemoryScheduling.OPTIMAL && node instanceof FloatingReadNode && !((FloatingReadNode) node).location().getLocationIdentity().isImmutable();
                 if (scheduleRead) {
                     FloatingReadNode read = (FloatingReadNode) node;
                     block = optimalBlock(read, strategy);
@@ -508,7 +508,7 @@
         assert memsched == MemoryScheduling.OPTIMAL;
 
         LocationIdentity locid = n.location().getLocationIdentity();
-        assert locid != FINAL_LOCATION;
+        assert !locid.isImmutable();
 
         Block upperBoundBlock = blockForMemoryNode(n.getLastLocationAccess());
         Block earliestBlock = earliestBlock(n);
@@ -996,7 +996,7 @@
             for (ScheduledNode i : instructions) {
                 if (i instanceof FloatingReadNode) {
                     FloatingReadNode frn = (FloatingReadNode) i;
-                    if (frn.location().getLocationIdentity() != FINAL_LOCATION) {
+                    if (!frn.location().getLocationIdentity().isImmutable()) {
                         state.addRead(frn);
                         if (nodesFor(b).contains(frn.getLastLocationAccess())) {
                             assert !state.isBeforeLastLocation(frn);
@@ -1043,7 +1043,7 @@
     private void processKillLocation(Node node, LocationIdentity identity, SortState state) {
         for (FloatingReadNode frn : state.readsSnapshot()) {
             LocationIdentity readLocation = frn.location().getLocationIdentity();
-            assert readLocation != FINAL_LOCATION;
+            assert !readLocation.isImmutable();
             if (frn.getLastLocationAccess() == node) {
                 assert identity == ANY_LOCATION || readLocation == identity || node instanceof MemoryCheckpoint.Multi : "location doesn't match: " + readLocation + ", " + identity;
                 state.clearBeforeLastLocation(frn);
diff -r 95b2f8b8250e -r 06bc22024f37 graal/com.oracle.graal.replacements/src/com/oracle/graal/replacements/SnippetTemplate.java
--- a/graal/com.oracle.graal.replacements/src/com/oracle/graal/replacements/SnippetTemplate.java	Tue Nov 04 00:13:30 2014 +0100
+++ b/graal/com.oracle.graal.replacements/src/com/oracle/graal/replacements/SnippetTemplate.java	Mon Nov 03 16:49:28 2014 -0800
@@ -952,7 +952,7 @@
                 for (Node usage : oldNode.usages().snapshot()) {
                     LocationIdentity identity = getLocationIdentity(usage);
                     boolean usageReplaced = false;
-                    if (identity != null && identity != FINAL_LOCATION) {
+                    if (identity != null && !identity.isImmutable()) {
                         // lastLocationAccess points into the snippet graph. find a proper
                         // MemoryCheckPoint inside the snippet graph
                         MemoryNode lastAccess = mmap.getLastLocationAccess(identity);