--- a/graal/com.oracle.graal.compiler.common/src/com/oracle/graal/compiler/common/type/Stamp.java	Tue Jul 01 15:41:54 2014 +0200
+++ b/graal/com.oracle.graal.compiler.common/src/com/oracle/graal/compiler/common/type/Stamp.java	Tue Jul 01 15:43:48 2014 +0200
@@ -115,4 +115,19 @@
     public Constant asConstant() {
         return null;
     }
+
+    /**
+     * Tries to improve this stamp with the stamp given as parameter. If successful, returns the new
+     * improved stamp. Otherwise, returns null.
+     * 
+     * @param other the stamp that should be used to improve this stamp
+     * @return the newly improved stamp of null if an improvement was not possible
+     */
+    public Stamp tryImprove(Stamp other) {
+        Stamp newStamp = this.join(other);
+        if (newStamp.equals(this)) {
+            return null;
+        }
+        return newStamp;
+    }
 }

--- a/graal/com.oracle.graal.compiler.common/src/com/oracle/graal/compiler/common/type/StampFactory.java	Tue Jul 01 15:41:54 2014 +0200
+++ b/graal/com.oracle.graal.compiler.common/src/com/oracle/graal/compiler/common/type/StampFactory.java	Tue Jul 01 15:43:48 2014 +0200
@@ -250,4 +250,30 @@
     public static Stamp exact(ResolvedJavaType type) {
         return new ObjectStamp(type, true, false, false);
     }
+
+    public static Stamp[] createParameterStamps(ResolvedJavaMethod method) {
+        Signature sig = method.getSignature();
+        Stamp[] result = new Stamp[sig.getParameterCount(!method.isStatic())];
+        int index = 0;
+
+        if (!method.isStatic()) {
+            result[index++] = StampFactory.declaredNonNull(method.getDeclaringClass());
+        }
+
+        int max = sig.getParameterCount(false);
+        ResolvedJavaType accessingClass = method.getDeclaringClass();
+        for (int i = 0; i < max; i++) {
+            JavaType type = sig.getParameterType(i, accessingClass);
+            Kind kind = type.getKind();
+            Stamp stamp;
+            if (kind == Kind.Object && type instanceof ResolvedJavaType) {
+                stamp = StampFactory.declared((ResolvedJavaType) type);
+            } else {
+                stamp = StampFactory.forKind(kind);
+            }
+            result[index++] = stamp;
+        }
+
+        return result;
+    }
 }