--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/GraalCompiler/src/com/sun/c1x/opt/TypeAnalyzer.java	Wed Apr 27 11:50:44 2011 +0200
@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.sun.c1x.opt;
+
+import com.sun.c1x.graph.IR;
+import com.sun.cri.ri.*;
+
+/**
+ * This class implements an iterative, flow-sensitve type analysis that can be
+ * used to remove redundant checkcasts and instanceof tests as well as devirtualize
+ * and deinterface method calls.
+ *
+ * @author Ben L. Titzer
+ */
+public class TypeAnalyzer {
+
+    final IR ir;
+
+    public TypeAnalyzer(IR ir) {
+        this.ir = ir;
+    }
+
+    // type information sources:
+    // new, anewarray, newarray
+    // parameter types
+    // instanceof
+    // checkcast
+    // array stores
+    // array loads
+    // field loads
+    // exception handler type
+    // equality comparison
+    // call to Object.clone()
+    // call to Class.newInstance()
+    // call to Array.newInstance()
+    // call to Class.isInstance()
+
+    // possible optimizations:
+    // remove redundant checkcasts
+    // fold instanceof tests
+    // remove dead branches in folded instanceof
+    // detect redundant store checks
+    // convert invokeinterface to invokevirtual when possible
+    // convert invokevirtual to invokespecial when possible
+    // remove finalizer checks
+    // specialize array copy calls
+    // transform reflective Class.newInstance() into allocation
+    // transform reflective Array.newInstance() into allocation
+    // transform reflective Class.isInstance() to checkcast
+    // transform reflective method invocation to direct method invocation
+
+    private static class TypeApprox {
+        final RiType type = null;
+        final boolean exact = false;
+    }
+}