--- a/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotOptions.java	Tue Oct 08 00:18:11 2013 +0200
+++ b/graal/com.oracle.graal.hotspot/src/com/oracle/graal/hotspot/HotSpotOptions.java	Tue Oct 08 21:47:46 2013 +0200
@@ -131,6 +131,14 @@
         OptionDescriptor desc = options.get(optionName);
         if (desc == null) {
             Logger.info("Could not find option " + optionName + " (use -G:+PrintFlags to see Graal options)");
+            List<OptionDescriptor> matches = fuzzyMatch(optionName);
+            if (!matches.isEmpty()) {
+                Logger.info("Did you mean one of the following?");
+                for (OptionDescriptor match : matches) {
+                    boolean isBoolean = match.getType() == boolean.class;
+                    Logger.info(String.format("    %s%s%s", isBoolean ? "(+/-)" : "", match.getName(), isBoolean ? "" : "=<value>"));
+                }
+            }
             return false;
         }
 
@@ -246,4 +254,38 @@
 
         System.exit(0);
     }
+
+    /**
+     * Compute string similarity based on Dice's coefficient.
+     * 
+     * Ported from str_similar() in globals.cpp.
+     */
+    static float stringSimiliarity(String str1, String str2) {
+        int hit = 0;
+        for (int i = 0; i < str1.length() - 1; ++i) {
+            for (int j = 0; j < str2.length() - 1; ++j) {
+                if ((str1.charAt(i) == str2.charAt(j)) && (str1.charAt(i + 1) == str2.charAt(j + 1))) {
+                    ++hit;
+                    break;
+                }
+            }
+        }
+        return 2.0f * hit / (str1.length() + str2.length());
+    }
+
+    private static final float FUZZY_MATCH_THRESHOLD = 0.7F;
+
+    /**
+     * Returns the set of options that fuzzy match a given option name.
+     */
+    private static List<OptionDescriptor> fuzzyMatch(String optionName) {
+        List<OptionDescriptor> matches = new ArrayList<>();
+        for (Map.Entry<String, OptionDescriptor> e : options.entrySet()) {
+            float score = stringSimiliarity(e.getKey(), optionName);
+            if (score >= FUZZY_MATCH_THRESHOLD) {
+                matches.add(e.getValue());
+            }
+        }
+        return matches;
+    }
 }

--- a/graal/com.oracle.graal.truffle/src/com/oracle/graal/truffle/GraalTruffleRuntime.java	Tue Oct 08 00:18:11 2013 +0200
+++ b/graal/com.oracle.graal.truffle/src/com/oracle/graal/truffle/GraalTruffleRuntime.java	Tue Oct 08 21:47:46 2013 +0200
@@ -69,6 +69,11 @@
     }
 
     @Override
+    public VirtualFrame createVirtualFrame(PackedFrame caller, Arguments arguments, FrameDescriptor frameDescriptor) {
+        return OptimizedCallTarget.createFrame(frameDescriptor, caller, arguments);
+    }
+
+    @Override
     public MaterializedFrame createMaterializedFrame(Arguments arguments) {
         return createMaterializedFrame(arguments);
     }

--- a/graal/com.oracle.graal.truffle/src/com/oracle/graal/truffle/OptimizedCallTarget.java	Tue Oct 08 00:18:11 2013 +0200
+++ b/graal/com.oracle.graal.truffle/src/com/oracle/graal/truffle/OptimizedCallTarget.java	Tue Oct 08 21:47:46 2013 +0200
@@ -166,7 +166,7 @@
         return rootNode.execute(frame);
     }
 
-    private static FrameWithoutBoxing createFrame(FrameDescriptor descriptor, PackedFrame caller, Arguments args) {
+    protected static FrameWithoutBoxing createFrame(FrameDescriptor descriptor, PackedFrame caller, Arguments args) {
         return new FrameWithoutBoxing(descriptor, caller, args);
     }
 

--- a/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/TruffleRuntime.java	Tue Oct 08 00:18:11 2013 +0200
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/TruffleRuntime.java	Tue Oct 08 21:47:46 2013 +0200
@@ -77,6 +77,14 @@
     Assumption createAssumption(String name);
 
     /**
+     * Creates a new virtual frame object that can be used to store values and is potentially
+     * optimizable by the runtime.
+     * 
+     * @return the newly created virtual frame object
+     */
+    VirtualFrame createVirtualFrame(PackedFrame caller, Arguments arguments, FrameDescriptor frameDescriptor);
+
+    /**
      * Creates a new materialized frame object that can be used to store values.
      * 
      * @return the newly created materialized frame object

--- a/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/impl/DefaultTruffleRuntime.java	Tue Oct 08 00:18:11 2013 +0200
+++ b/graal/com.oracle.truffle.api/src/com/oracle/truffle/api/impl/DefaultTruffleRuntime.java	Tue Oct 08 21:47:46 2013 +0200
@@ -50,6 +50,11 @@
     }
 
     @Override
+    public VirtualFrame createVirtualFrame(PackedFrame caller, Arguments arguments, FrameDescriptor frameDescriptor) {
+        return new DefaultVirtualFrame(frameDescriptor, caller, arguments);
+    }
+
+    @Override
     public MaterializedFrame createMaterializedFrame(Arguments arguments) {
         return createMaterializedFrame(arguments, new FrameDescriptor());
     }

--- a/mx/commands.py	Tue Oct 08 00:18:11 2013 +0200
+++ b/mx/commands.py	Tue Oct 08 21:47:46 2013 +0200
@@ -365,9 +365,18 @@
 
     return jdk
 
+def _updateInstalledGraalOptionsFile(jdk):
+    graalOptions = join(_graal_home, 'graal.options')
+    jreLibDir = join(jdk, 'jre', 'lib')
+    if exists(graalOptions):
+        shutil.copy(graalOptions, join(jreLibDir, 'graal.options'))
+    else:
+        toDelete = join(jreLibDir, 'graal.options')
+        if exists(toDelete):
+            os.unlink(toDelete)
+
 def _installGraalJarInJdks(graalDist):
     graalJar = graalDist.path
-    graalOptions = join(_graal_home, 'graal.options')
     jdks = _jdksDir()
     if exists(jdks):
         for e in os.listdir(jdks):
@@ -379,9 +388,6 @@
                 os.close(fd)
                 shutil.move(tmp, join(jreLibDir, 'graal.jar'))
 
-                if exists(graalOptions):
-                    shutil.copy(graalOptions, join(jreLibDir, 'graal.options'))
-
 # run a command in the windows SDK Debug Shell
 def _runInDebugShell(cmd, workingDir, logFile=None, findInOutput=None, respondTo=None):
     if respondTo is None:
@@ -692,6 +698,7 @@
 
     build = vmbuild if vmbuild is not None else _vmbuild if _vmSourcesAvailable else 'product'
     jdk = _jdk(build, vmToCheck=vm, installGraalJar=False)
+    _updateInstalledGraalOptionsFile(jdk)
     mx.expand_project_in_args(args)
     if _make_eclipse_launch:
         mx.make_eclipse_launch(args, 'graal-' + build, name=None, deps=mx.project('com.oracle.graal.hotspot').all_deps([], True))