--- a/graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/Kind.java	Sat Jan 17 11:26:18 2015 +0100
+++ b/graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/Kind.java	Mon Jan 19 14:46:21 2015 +0100
@@ -70,6 +70,7 @@
     private final boolean isStackInt;
     private final Class<?> primitiveJavaClass;
     private final Class<?> boxedJavaClass;
+    private final EnumKey key = new EnumKey(this);
 
     private Kind(char typeChar, String javaName, boolean isStackInt, Class<?> primitiveJavaClass, Class<?> boxedJavaClass) {
         this.typeChar = typeChar;
@@ -95,6 +96,10 @@
         return javaName;
     }
 
+    public Key getKey() {
+        return key;
+    }
+
     /**
      * Checks whether this type is a Java primitive type.
      *

--- a/graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/PlatformKind.java	Sat Jan 17 11:26:18 2015 +0100
+++ b/graal/com.oracle.graal.api.meta/src/com/oracle/graal/api/meta/PlatformKind.java	Mon Jan 19 14:46:21 2015 +0100
@@ -22,6 +22,8 @@
  */
 package com.oracle.graal.api.meta;
 
+import com.sun.javafx.collections.MappingChange.Map;
+
 /**
  * Represents a platform-specific low-level type for values.
  */
@@ -31,6 +33,43 @@
 
     JavaConstant getDefaultValue();
 
+    public interface Key {
+
+    }
+
+    public class EnumKey implements Key {
+        @SuppressWarnings("rawtypes") private final Enum e;
+
+        @SuppressWarnings("rawtypes")
+        public EnumKey(Enum e) {
+            this.e = e;
+        }
+
+        @Override
+        public int hashCode() {
+            return e.ordinal() ^ e.name().hashCode();
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (obj == this) {
+                return true;
+            }
+            if (obj instanceof EnumKey) {
+                EnumKey that = (EnumKey) obj;
+                return this.e == that.e;
+            }
+            return false;
+        }
+    }
+
+    /**
+     * Gets a value associated with this object that can be used as a stable key in a {@link Map}.
+     * The {@link Object#hashCode()} implementation of the returned value should be stable between
+     * VM executions.
+     */
+    Key getKey();
+
     default int getVectorLength() {
         return 1;
     }

--- a/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotRegisterConfig.java	Sat Jan 17 11:26:18 2015 +0100
+++ b/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotRegisterConfig.java	Mon Jan 19 14:46:21 2015 +0100
@@ -52,7 +52,7 @@
 
     private final boolean allAllocatableAreCallerSaved;
 
-    private final Map<PlatformKind, Register[]> categorized = new ConcurrentHashMap<>();
+    private final Map<PlatformKind.Key, Register[]> categorized = new ConcurrentHashMap<>();
 
     private final RegisterAttributes[] attributesMap;
 
@@ -66,8 +66,10 @@
     }
 
     public Register[] getAllocatableRegisters(PlatformKind kind) {
-        if (categorized.containsKey(kind)) {
-            return categorized.get(kind);
+        PlatformKind.Key key = kind.getKey();
+        if (categorized.containsKey(key)) {
+            Register[] val = categorized.get(key);
+            return val;
         }
 
         ArrayList<Register> list = new ArrayList<>();
@@ -78,7 +80,7 @@
         }
 
         Register[] ret = list.toArray(new Register[list.size()]);
-        categorized.put(kind, ret);
+        categorized.put(key, ret);
         return ret;
     }