diff --git a/dev/core/src/com/google/gwt/dev/jjs/ast/JMethod.java b/dev/core/src/com/google/gwt/dev/jjs/ast/JMethod.java
index 0512029..fa11ba6 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/ast/JMethod.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/ast/JMethod.java
@@ -18,6 +18,7 @@
 import com.google.gwt.dev.jjs.InternalCompilerException;
 import com.google.gwt.dev.jjs.SourceInfo;
 import com.google.gwt.dev.jjs.SourceOrigin;
+import com.google.gwt.dev.jjs.ast.js.JsniMethodBody;
 import com.google.gwt.dev.util.StringInterner;
 import com.google.gwt.dev.util.collect.Lists;
 
@@ -499,6 +500,9 @@
    */
   public void removeParam(int index) {
     params = Lists.remove(params, index);
+    if (isNative()) {
+      ((JsniMethodBody) getBody()).getFunc().getParameters().remove(index);
+    }
   }
 
   /**
diff --git a/dev/core/src/com/google/gwt/dev/jjs/ast/JMethodCall.java b/dev/core/src/com/google/gwt/dev/jjs/ast/JMethodCall.java
index 30c5c03..1c44461 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/ast/JMethodCall.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/ast/JMethodCall.java
@@ -145,6 +145,13 @@
   }
 
   /**
+   * Creates a new method call to the same method using the same instance but without parameters.
+   */
+  public JMethodCall cloneWithoutParameters() {
+    return new JMethodCall(this, instance);
+  }
+
+  /**
    * Returns the call arguments.
    */
   public List<JExpression> getArgs() {
@@ -197,13 +204,6 @@
   }
 
   /**
-   * Removes the argument at the specified index.
-   */
-  public void removeArg(int index) {
-    args = Lists.remove(args, index);
-  }
-
-  /**
    * Resolve an external reference during AST stitching.
    */
   public void resolve(JMethod newMethod) {
diff --git a/dev/core/src/com/google/gwt/dev/jjs/ast/JNewInstance.java b/dev/core/src/com/google/gwt/dev/jjs/ast/JNewInstance.java
index 02caf0d..8288f2e 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/ast/JNewInstance.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/ast/JNewInstance.java
@@ -36,6 +36,11 @@
     setStaticDispatchOnly();
   }
 
+  @Override
+  public JNewInstance cloneWithoutParameters() {
+    return new JNewInstance(this);
+  }
+
   public JClassType getClassType() {
     return getTarget().getEnclosingType();
   }
diff --git a/dev/core/src/com/google/gwt/dev/jjs/ast/JProgram.java b/dev/core/src/com/google/gwt/dev/jjs/ast/JProgram.java
index 35a20a2..4755cf4 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/ast/JProgram.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/ast/JProgram.java
@@ -195,9 +195,12 @@
    */
   public static JExpressionStatement createAssignmentStmt(SourceInfo info, JExpression lhs,
       JExpression rhs) {
-    JBinaryOperation assign =
-        new JBinaryOperation(info, lhs.getType(), JBinaryOperator.ASG, lhs, rhs);
-    return assign.makeStatement();
+    return createAssignment(info, lhs, rhs).makeStatement();
+  }
+
+  public static JBinaryOperation createAssignment(SourceInfo info, JExpression lhs,
+      JExpression rhs) {
+    return new JBinaryOperation(info, lhs.getType(), JBinaryOperator.ASG, lhs, rhs);
   }
 
   public static JLocal createLocal(SourceInfo info, String name, JType type, boolean isFinal,
diff --git a/dev/core/src/com/google/gwt/dev/jjs/ast/js/JMultiExpression.java b/dev/core/src/com/google/gwt/dev/jjs/ast/js/JMultiExpression.java
index 4a8d6a5..1509c47 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/ast/js/JMultiExpression.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/ast/js/JMultiExpression.java
@@ -66,6 +66,13 @@
   }
 
   /**
+   * Adds {@code expressions} to the multi expression at position {@code index}.
+   */
+  public void addExpressions(int index, JExpression...expressions) {
+    this.expressions.addAll(index, Arrays.asList(expressions));
+  }
+
+  /**
    * Adds a list of expressions to the multi expression at position {@code index}.
    */
   public void addExpressions(int index, List<JExpression> expressions) {
diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/CompoundAssignmentNormalizer.java b/dev/core/src/com/google/gwt/dev/jjs/impl/CompoundAssignmentNormalizer.java
index 947c914..e0dd5bc 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/CompoundAssignmentNormalizer.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/CompoundAssignmentNormalizer.java
@@ -61,6 +61,10 @@
    */
   private class BreakupAssignOpsVisitor extends JModVisitorWithTemporaryVariableCreation {
 
+    public BreakupAssignOpsVisitor(OptimizerContext optimizerCtx) {
+      super(optimizerCtx);
+    }
+
     /**
      * Replaces side effects in lvalue.
      */
@@ -270,11 +274,11 @@
   private final CloneExpressionVisitor cloner = new CloneExpressionVisitor();
 
   public void accept(JNode node) {
-    BreakupAssignOpsVisitor breaker = new BreakupAssignOpsVisitor();
+    BreakupAssignOpsVisitor breaker =
+        new BreakupAssignOpsVisitor(OptimizerContext.NULL_OPTIMIZATION_CONTEXT);
     breaker.accept(node);
   }
 
-
   // Name to assign to temporaries. All temporaries are created with the same name, which is
   // not a problem as they are referred to by reference.
   // {@link GenerateJavaScriptAst.FixNameClashesVisitor} will resolve into unique names when
diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/DeadCodeElimination.java b/dev/core/src/com/google/gwt/dev/jjs/impl/DeadCodeElimination.java
index 078f750..25aff76 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/DeadCodeElimination.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/DeadCodeElimination.java
@@ -71,6 +71,7 @@
 import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger;
 import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger.Event;
 import com.google.gwt.thirdparty.guava.common.annotations.VisibleForTesting;
+import com.google.gwt.thirdparty.guava.common.collect.ImmutableMap;
 import com.google.gwt.thirdparty.guava.common.collect.Lists;
 import com.google.gwt.thirdparty.guava.common.collect.Sets;
 
@@ -79,7 +80,6 @@
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashSet;
-import java.util.IdentityHashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
@@ -460,16 +460,6 @@
         ignoringExpressionOutput.remove(instance);
       }
 
-      int paramCount = target.getParams().size();
-      for (int i = paramCount; i < x.getArgs().size(); ++i) {
-        JExpression arg = x.getArgs().get(i);
-        ignoringExpressionOutput.remove(arg);
-        if (!arg.hasSideEffects()) {
-          x.removeArg(i--);
-          madeChanges();
-        }
-      }
-
       // Normal optimizations.
       JDeclaredType targetType = target.getEnclosingType();
       if (targetType == program.getTypeJavaLangString() ||
@@ -761,9 +751,6 @@
       if (target.isStatic() && x.getInstance() != null) {
         ignoringExpressionOutput.add(x.getInstance());
       }
-      List<JExpression> args = x.getArgs();
-      List<JExpression> ignoredArgs = args.subList(target.getParams().size(), args.size());
-      ignoringExpressionOutput.addAll(ignoredArgs);
       return true;
     }
 
@@ -2003,20 +1990,22 @@
 
   private final JProgram program;
 
-  private final Map<JType, Class<?>> typeClassMap = new IdentityHashMap<JType, Class<?>>();
+  private final Map<JType, Class<?>> typeClassMap;
 
   public DeadCodeElimination(JProgram program) {
     this.program = program;
-    typeClassMap.put(program.getTypeJavaLangObject(), Object.class);
-    typeClassMap.put(program.getTypeJavaLangString(), String.class);
-    typeClassMap.put(program.getTypePrimitiveBoolean(), boolean.class);
-    typeClassMap.put(program.getTypePrimitiveByte(), byte.class);
-    typeClassMap.put(program.getTypePrimitiveChar(), char.class);
-    typeClassMap.put(program.getTypePrimitiveDouble(), double.class);
-    typeClassMap.put(program.getTypePrimitiveFloat(), float.class);
-    typeClassMap.put(program.getTypePrimitiveInt(), int.class);
-    typeClassMap.put(program.getTypePrimitiveLong(), long.class);
-    typeClassMap.put(program.getTypePrimitiveShort(), short.class);
+    typeClassMap = new ImmutableMap.Builder()
+        .put(program.getTypeJavaLangObject(), Object.class)
+        .put(program.getTypeJavaLangString(), String.class)
+        .put(program.getTypePrimitiveBoolean(), boolean.class)
+        .put(program.getTypePrimitiveByte(), byte.class)
+        .put(program.getTypePrimitiveChar(), char.class)
+        .put(program.getTypePrimitiveDouble(), double.class)
+        .put(program.getTypePrimitiveFloat(), float.class)
+        .put(program.getTypePrimitiveInt(), int.class)
+        .put(program.getTypePrimitiveLong(), long.class)
+        .put(program.getTypePrimitiveShort(), short.class)
+        .build();
   }
 
   private OptimizerStats execImpl(Iterable<? extends JNode> nodes, OptimizerContext optimizerCtx) {
diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/ImplementClassLiteralsAsFields.java b/dev/core/src/com/google/gwt/dev/jjs/impl/ImplementClassLiteralsAsFields.java
index 8e72803..d622401 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/ImplementClassLiteralsAsFields.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/ImplementClassLiteralsAsFields.java
@@ -166,13 +166,8 @@
       JMethodCall createCall(SourceInfo info, JProgram program, JType type,
           JLiteral superclassLiteral) {
 
-        // Class.createForClass(packageName, typeName, runtimeTypeReference, superclassliteral)
-        JMethodCall call = createBaseCall(info, program, type, "Class.createForInterface");
-
-        call.addArg(new JRuntimeTypeReference(info, program.getTypeJavaLangObject(),
-            (JReferenceType) type));
-        call.addArg(superclassLiteral);
-        return call;
+        // Class.createForInterface(packageName, typeName)
+        return createBaseCall(info, program, type, "Class.createForInterface");
       }
     };
 
diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/JModVisitorWithTemporaryVariableCreation.java b/dev/core/src/com/google/gwt/dev/jjs/impl/JModVisitorWithTemporaryVariableCreation.java
index e4ea7f4..c9487aa 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/JModVisitorWithTemporaryVariableCreation.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/JModVisitorWithTemporaryVariableCreation.java
@@ -21,7 +21,6 @@
 import com.google.gwt.dev.jjs.ast.JLocal;
 import com.google.gwt.dev.jjs.ast.JLocalRef;
 import com.google.gwt.dev.jjs.ast.JMethodBody;
-import com.google.gwt.dev.jjs.ast.JModVisitor;
 import com.google.gwt.dev.jjs.ast.JProgram;
 import com.google.gwt.dev.jjs.ast.JStatement;
 import com.google.gwt.dev.jjs.ast.JType;
@@ -33,19 +32,16 @@
  * A JModVisitor capable of creating temporary local variables and placing their declarations in an
  * appropriate preceding place.
  */
-public abstract class JModVisitorWithTemporaryVariableCreation extends JModVisitor {
+public abstract class JModVisitorWithTemporaryVariableCreation extends JChangeTrackingVisitor {
 
   /**
    * Stack to keep track of where to insert the new variable declaration.
    * The top of the stack is the statement where declarations will be inserted.
    */
   private final Deque<Context> currentDeclarationInsertionPoint = Queues.newArrayDeque();
-  private JMethodBody currentMethodBody = null;
 
-  @Override
-  public void endVisit(JMethodBody body, Context ctx) {
-    assert currentMethodBody == body;
-    currentMethodBody = null;
+  public JModVisitorWithTemporaryVariableCreation(OptimizerContext optimizerCtx) {
+    super(optimizerCtx);
   }
 
   @Override
@@ -58,13 +54,6 @@
   }
 
   @Override
-  public boolean visit(JMethodBody body, Context ctx) {
-    assert currentMethodBody == null;
-    currentMethodBody = body;
-    return true;
-  }
-
-  @Override
   public final boolean visit(JStatement x, Context ctx) {
     if (ctx.canInsert()) {
       currentDeclarationInsertionPoint.push(ctx);
@@ -73,7 +62,8 @@
   }
 
   protected JLocal createTempLocal(SourceInfo info, JType type) {
-    assert currentMethodBody != null;
+    assert !getCurrentMethod().isNative();
+    JMethodBody currentMethodBody = (JMethodBody) getCurrentMethod().getBody();
     String temporaryLocalName = newTemporaryLocalName(info, type, currentMethodBody);
     JLocal local = JProgram.createLocal(info, temporaryLocalName, type, false, currentMethodBody);
     JDeclarationStatement declarationStatement =
diff --git a/dev/core/src/com/google/gwt/dev/jjs/impl/Pruner.java b/dev/core/src/com/google/gwt/dev/jjs/impl/Pruner.java
index 20645e1..1031899 100644
--- a/dev/core/src/com/google/gwt/dev/jjs/impl/Pruner.java
+++ b/dev/core/src/com/google/gwt/dev/jjs/impl/Pruner.java
@@ -32,6 +32,8 @@
 import com.google.gwt.dev.jjs.ast.JField;
 import com.google.gwt.dev.jjs.ast.JFieldRef;
 import com.google.gwt.dev.jjs.ast.JInterfaceType;
+import com.google.gwt.dev.jjs.ast.JLocal;
+import com.google.gwt.dev.jjs.ast.JLocalRef;
 import com.google.gwt.dev.jjs.ast.JMethod;
 import com.google.gwt.dev.jjs.ast.JMethodBody;
 import com.google.gwt.dev.jjs.ast.JMethodCall;
@@ -48,21 +50,19 @@
 import com.google.gwt.dev.jjs.ast.JVariableRef;
 import com.google.gwt.dev.jjs.ast.js.JMultiExpression;
 import com.google.gwt.dev.jjs.ast.js.JsniFieldRef;
-import com.google.gwt.dev.jjs.ast.js.JsniMethodBody;
 import com.google.gwt.dev.jjs.ast.js.JsniMethodRef;
-import com.google.gwt.dev.js.ast.JsFunction;
 import com.google.gwt.dev.util.collect.Stack;
 import com.google.gwt.dev.util.log.speedtracer.CompilerEventType;
 import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger;
 import com.google.gwt.dev.util.log.speedtracer.SpeedTracerLogger.Event;
 import com.google.gwt.thirdparty.guava.common.base.Predicate;
 import com.google.gwt.thirdparty.guava.common.base.Predicates;
+import com.google.gwt.thirdparty.guava.common.collect.ArrayListMultimap;
+import com.google.gwt.thirdparty.guava.common.collect.Iterables;
+import com.google.gwt.thirdparty.guava.common.collect.ListMultimap;
 
-import java.util.ArrayList;
-import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
-import java.util.Map;
 import java.util.Set;
 
 /**
@@ -90,9 +90,9 @@
    * references to pruned variables and methods by references to the null field
    * and null method, and drop assignments to pruned variables.
    */
-  private class CleanupRefsVisitor extends JChangeTrackingVisitor {
+  private class CleanupRefsVisitor extends JModVisitorWithTemporaryVariableCreation {
     private final Stack<JExpression> lValues = new Stack<JExpression>();
-    private final Map<JMethod, ArrayList<JParameter>> methodToOriginalParamsMap;
+    private final ListMultimap<JMethod, JParameter> priorParametersByMethod;
     private final Set<? extends JNode> referencedNonTypes;
     {
       // Initialize a sentinel value to avoid having to check for empty stack.
@@ -100,10 +100,11 @@
     }
 
     public CleanupRefsVisitor(Set<? extends JNode> referencedNodes,
-        Map<JMethod, ArrayList<JParameter>> methodToOriginalParamsMap, OptimizerContext optimizerCtx) {
+        ListMultimap<JMethod, JParameter> priorParametersByMethod,
+        OptimizerContext optimizerCtx) {
       super(optimizerCtx);
       this.referencedNonTypes = referencedNodes;
-      this.methodToOriginalParamsMap = methodToOriginalParamsMap;
+      this.priorParametersByMethod = priorParametersByMethod;
     }
 
     @Override
@@ -129,6 +130,7 @@
 
     @Override
     public void endVisit(JDeclarationStatement x, Context ctx) {
+      super.endVisit(x, ctx);
       lValues.pop();
       // The variable may have been pruned.
       if (isVariablePruned(x.getVariableRef().getTarget())) {
@@ -175,11 +177,7 @@
         return;
       }
 
-      // Did we prune the parameters of the method we're calling?
-      if (methodToOriginalParamsMap.containsKey(method)) {
-        JMethodCall newCall = new JMethodCall(x, x.getInstance());
-        replaceForPrunedParameters(x, newCall, ctx);
-      }
+      maybeReplaceForPrunedParameters(x, ctx);
     }
 
     @Override
@@ -203,11 +201,7 @@
 
     @Override
     public void endVisit(JNewInstance x, Context ctx) {
-      // Did we prune the parameters of the method we're calling?
-      if (methodToOriginalParamsMap.containsKey(x.getTarget())) {
-        JMethodCall newCall = new JNewInstance(x);
-        replaceForPrunedParameters(x, newCall, ctx);
-      }
+      maybeReplaceForPrunedParameters(x, ctx);
     }
 
     @Override
@@ -251,6 +245,7 @@
 
     @Override
     public boolean visit(JDeclarationStatement x, Context ctx) {
+      super.visit(x, ctx);
       lValues.push(x.getVariableRef());
       return true;
     }
@@ -296,41 +291,77 @@
       }
     }
 
-    private void replaceForPrunedParameters(JMethodCall x, JMethodCall newCall, Context ctx) {
+    // Arguments for pruned parameters will be pushed right into a multiexpression that will be
+    // evaluated with the next arg, e.g. m(arg1, (prunnedArg2, prunnedArg3, arg4)).
+    private void maybeReplaceForPrunedParameters(JMethodCall x, Context ctx) {
+      if (!priorParametersByMethod.containsKey(x.getTarget())) {
+        // No parameter was pruned.
+        return;
+      }
+
+      JMethodCall replacementCall = x.cloneWithoutParameters();
+
       assert !x.getTarget().canBePolymorphic();
-      List<JParameter> originalParams = methodToOriginalParamsMap.get(x.getTarget());
-      JMultiExpression currentMulti = null;
-      for (int i = 0, c = x.getArgs().size(); i < c; ++i) {
-        JExpression arg = x.getArgs().get(i);
-        JParameter param = null;
-        if (i < originalParams.size()) {
-          param = originalParams.get(i);
-        }
+      List<JParameter> originalParams = priorParametersByMethod.get(x.getTarget());
 
-        if (param != null && referencedNonTypes.contains(param)) {
-          // If there is an existing multi, terminate it.
-          if (currentMulti != null) {
-            currentMulti.addExpressions(arg);
-            newCall.addArg(currentMulti);
-            currentMulti = null;
-          } else {
-            newCall.addArg(arg);
-          }
+      // The method and the call agree in the number of parameters.
+      assert originalParams.size() == x.getArgs().size();
+
+      // Traverse the call arguments left to right.
+      SourceInfo sourceInfo = x.getSourceInfo();
+      JMultiExpression unevaluatedArgumentsForPrunedParameters =
+          new JMultiExpression(sourceInfo);
+      List<JExpression> args = x.getArgs();
+      for (int currentArgumentIndex = 0; currentArgumentIndex < args.size();
+          ++currentArgumentIndex) {
+        JExpression arg = args.get(currentArgumentIndex);
+
+        // If the parameter was not pruned .
+        if (referencedNonTypes.contains(originalParams.get(currentArgumentIndex))) {
+          // Add the current argument to the list of unevaluated arguments and pass the multi
+          // expression to the call.
+          unevaluatedArgumentsForPrunedParameters.addExpressions(arg);
+          replacementCall.addArg(unevaluatedArgumentsForPrunedParameters);
+          // Reset the accumulating multi expression.
+          unevaluatedArgumentsForPrunedParameters =  new JMultiExpression(sourceInfo);
         } else if (arg.hasSideEffects()) {
-          // The argument is only needed for side effects, add it to a multi.
-          if (currentMulti == null) {
-            currentMulti = new JMultiExpression(x.getSourceInfo());
-          }
-          currentMulti.addExpressions(arg);
+          // If the argument was pruned and has sideffects accumulate it; otherwise discard.
+          unevaluatedArgumentsForPrunedParameters.addExpressions(arg);
         }
       }
 
-      // Add any orphaned parameters on the end. Extra params are OK.
-      if (currentMulti != null) {
-        newCall.addArg(currentMulti);
+      if (unevaluatedArgumentsForPrunedParameters.isEmpty()) {
+        // We are done, all (side effectful) parameters have been evaluated.
+        ctx.replaceMe(replacementCall);
+        return;
       }
 
-      ctx.replaceMe(newCall);
+      // If the last few parameters where pruned, we need to evaluate the (side effectful) arguments
+      // for those parameters.
+      if (replacementCall.getArgs().isEmpty()) {
+        // All parameters have been pruned, replace by (prunedArg1, ..., prunedArgn, m()).
+        unevaluatedArgumentsForPrunedParameters.addExpressions(replacementCall);
+        ctx.replaceMe(unevaluatedArgumentsForPrunedParameters);
+        return;
+      }
+      // Some parameters have been pruned from the end, replace by
+      // m(arg1,..., (lastArg = lastUnprunedArg, remainingArgs, lastArg))
+      JExpression lastArg = Iterables.getLast(replacementCall.getArgs());
+      JLocal tempVar =
+          createTempLocal(sourceInfo, Iterables.getLast(
+              Iterables.filter(originalParams, Predicates.in(referencedNonTypes))).getType());
+      unevaluatedArgumentsForPrunedParameters.addExpressions(0, JProgram.createAssignment(
+          lastArg.getSourceInfo(), new JLocalRef(sourceInfo, tempVar), lastArg));
+      unevaluatedArgumentsForPrunedParameters.addExpressions(new JLocalRef(sourceInfo, tempVar));
+      replacementCall.setArg(replacementCall.getArgs().size() - 1, unevaluatedArgumentsForPrunedParameters);
+      ctx.replaceMe(replacementCall);
+    }
+
+    @Override
+    protected String newTemporaryLocalName(SourceInfo info, JType type, JMethodBody methodBody) {
+      // The name can be reused a later pass will make sure each instance of JLocal in a method
+      // has a different name.
+      return "lastArg";
     }
   }
 
@@ -339,8 +370,8 @@
    * unreferenced methods and fields from their containing classes.
    */
   private class PruneVisitor extends JChangeTrackingVisitor {
-    private final Map<JMethod, ArrayList<JParameter>> methodToOriginalParamsMap =
-        new HashMap<JMethod, ArrayList<JParameter>>();
+    private final ListMultimap<JMethod, JParameter> priorParametersByMethod =
+        ArrayListMultimap.create();
     private final Set<? extends JNode> referencedNonTypes;
     private final Set<? extends JReferenceType> referencedTypes;
 
@@ -351,8 +382,8 @@
       this.referencedNonTypes = referencedNodes;
     }
 
-    public Map<JMethod, ArrayList<JParameter>> getMethodToOriginalParamsMap() {
-      return methodToOriginalParamsMap;
+    public ListMultimap<JMethod, JParameter> getPriorParametersByMethod() {
+      return priorParametersByMethod;
     }
 
     @Override
@@ -418,21 +449,14 @@
           return true;
         }
 
-        JsFunction func = x.isNative() ? ((JsniMethodBody) x.getBody()).getFunc() : null;
-
-        ArrayList<JParameter> originalParams = new ArrayList<JParameter>(x.getParams());
+        priorParametersByMethod.putAll(x, x.getParams());
 
         for (int i = 0; i < x.getParams().size(); ++i) {
           JParameter param = x.getParams().get(i);
           if (!referencedNonTypes.contains(param)) {
             x.removeParam(i);
             madeChanges();
-            // Remove the associated JSNI parameter
-            if (func != null) {
-              func.getParameters().remove(i);
-            }
             --i;
-            methodToOriginalParamsMap.put(x, originalParams);
           }
         }
       }
@@ -659,7 +683,7 @@
     }
     CleanupRefsVisitor cleaner =
         new CleanupRefsVisitor(livenessAnalyzer.getLiveFieldsAndMethods(), pruner
-            .getMethodToOriginalParamsMap(), optimizerCtx);
+            .getPriorParametersByMethod(), optimizerCtx);
     cleaner.accept(program.getDeclaredTypes());
 
     JavaAstVerifier.assertProgramIsConsistent(program);
diff --git a/dev/core/test/com/google/gwt/dev/jjs/impl/JModVisitorWithTemporaryVariableCreationTest.java b/dev/core/test/com/google/gwt/dev/jjs/impl/JModVisitorWithTemporaryVariableCreationTest.java
index 15cc407..1dbf024 100644
--- a/dev/core/test/com/google/gwt/dev/jjs/impl/JModVisitorWithTemporaryVariableCreationTest.java
+++ b/dev/core/test/com/google/gwt/dev/jjs/impl/JModVisitorWithTemporaryVariableCreationTest.java
@@ -40,6 +40,10 @@
      */
     private JExpression dontBother;
 
+    public AlwaysReplacer() {
+      super(OptimizerContext.NULL_OPTIMIZATION_CONTEXT);
+    }
+
     @Override
     public boolean visit(JExpressionStatement x, Context ctx) {
       dontBother = x.getExpr();
diff --git a/dev/core/test/com/google/gwt/dev/jjs/impl/PrunerTest.java b/dev/core/test/com/google/gwt/dev/jjs/impl/PrunerTest.java
index 4d1916e..6e71b96 100644
--- a/dev/core/test/com/google/gwt/dev/jjs/impl/PrunerTest.java
+++ b/dev/core/test/com/google/gwt/dev/jjs/impl/PrunerTest.java
@@ -53,6 +53,9 @@
         "  public void method2() { field2 = usedConstant; }",
         "  UsedClass(UninstantiatedClass c) { }",
         "  UsedClass(UninstantiatedClass c1, UninstantiatedClass c2) { }",
+        "  UsedClass(UninstantiatedClass c1, int i, UninstantiatedClass c2) { field2 = i; }",
+        "  UsedClass(UninstantiatedClass c1, int i, UninstantiatedClass c2, int j) " +
+            "{ field2 = i + j; }",
         "}");
     addSnippetClassDecl(
         "static native void usedNativeMethod(UninstantiatedClass c, UsedClass c2)",
@@ -107,6 +110,8 @@
         "methodWithUninstantiatedParam(null);",
         "new UsedClass(null);",
         "new UsedClass(returnUninstantiatedClass(), returnUninstantiatedClass());",
+        "new UsedClass(returnUninstantiatedClass(), 3, returnUninstantiatedClass());",
+        "new UsedClass(returnUninstantiatedClass(), 3, returnUninstantiatedClass(), 4);",
         "UninstantiatedClass localUninstantiated = null;",
         "JsProtoImpl jsp = new JsProtoImpl();"
         )).intoString(
@@ -118,7 +123,12 @@
             "null.nullMethod();",
             "EntryPoint.methodWithUninstantiatedParam();",
             "new EntryPoint$UsedClass();",
-            "new EntryPoint$UsedClass((EntryPoint.returnUninstantiatedClass(), EntryPoint.returnUninstantiatedClass()));",
+            "EntryPoint.returnUninstantiatedClass();",
+            "EntryPoint.returnUninstantiatedClass();",
+            "new EntryPoint$UsedClass();",
+            "int lastArg;",
+            "new EntryPoint$UsedClass((lastArg = (EntryPoint.returnUninstantiatedClass(), 3), EntryPoint.returnUninstantiatedClass(), lastArg));",
+            "new EntryPoint$UsedClass((EntryPoint.returnUninstantiatedClass(), 3), (EntryPoint.returnUninstantiatedClass(), 4));",
             "new EntryPoint$JsProtoImpl();"
             );