diff --git a/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java b/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
index b8144652ee8..8447375e0ad 100644
--- a/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
+++ b/idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java
@@ -119,10 +119,9 @@ public class ExpressionCodegen extends JetVisitor {
         myLoopEnds.push(end);
 
         gen(expression.getCondition());
-        unboxBoolean();
-        v.ifeq(end);
+        myStack.pop().condJump(end, true, v);
 
-        genToUnit(expression.getBody());
+        gen(expression.getBody(), Type.VOID_TYPE);
         v.goTo(condition);
 
         v.mark(end);
@@ -139,7 +138,7 @@ public class ExpressionCodegen extends JetVisitor {
         Label end = new Label();
         myLoopEnds.push(end);
 
-        genToUnit(expression.getBody());
+        gen(expression.getBody(), Type.VOID_TYPE);
 
         gen(expression.getCondition());
         unboxBoolean();
@@ -178,19 +177,11 @@ public class ExpressionCodegen extends JetVisitor {
 
         myStack.pop().condJump(endLabel, inverse, v);
 
-        genToUnit(expression);
+        gen(expression, Type.VOID_TYPE);
 
         v.mark(endLabel);
     }
 
-    private void genToUnit(JetExpression expression) {
-        gen(expression);
-
-        if (!isUnitType(expression)) {
-            v.pop();
-        }
-    }
-
     @Override
     public void visitConstantExpression(JetConstantExpression expression) {
         myStack.push(StackValue.constant(expression.getValue()));
@@ -227,10 +218,24 @@ public class ExpressionCodegen extends JetVisitor {
 
     @Override
     public void visitBlockExpression(JetBlockExpression expression) {
+        List<JetElement> statements = expression.getStatements();
+        generateBlock(statements);
+    }
+
+    @Override
+    public void visitFunctionLiteralExpression(JetFunctionLiteralExpression expression) {
+        if (bindingContext.isBlock(expression)) {
+            generateBlock(expression.getBody());
+        }
+        else {
+            throw new UnsupportedOperationException("don't know how to generate non-block function literals");
+        }
+    }
+
+    private void generateBlock(List<JetElement> statements) {
         Label blockStart = new Label();
         v.mark(blockStart);
 
-        List<JetElement> statements = expression.getStatements();
         for (JetElement statement : statements) {
             if (statement instanceof JetProperty) {
                 myMap.enter(bindingContext.getPropertyDescriptor((JetProperty) statement));
@@ -254,7 +259,6 @@ public class ExpressionCodegen extends JetVisitor {
                 v.visitLocalVariable(var.getName(), outType.getDescriptor(), null, blockStart, blockEnd, index);
             }
         }
-
     }
 
     @Override
@@ -464,6 +468,9 @@ public class ExpressionCodegen extends JetVisitor {
                     if (op.getName().equals("plus")) {
                         opcode = Opcodes.IADD;
                     }
+                    else if (op.getName().equals("times")) {
+                        opcode = Opcodes.IMUL;
+                    }
                     else {
                         throw new UnsupportedOperationException("Don't know how to generate binary op method " + op.getName());
                     }
@@ -508,10 +515,6 @@ public class ExpressionCodegen extends JetVisitor {
         }
     }
 
-    private boolean isUnitType(JetExpression e) {
-        return false; // TODO:!!!
-    }
-
     @Override
     public void visitProperty(JetProperty property) {
         PropertyDescriptor propertyDescriptor = bindingContext.getPropertyDescriptor(property);
diff --git a/idea/src/org/jetbrains/jet/codegen/StackValue.java b/idea/src/org/jetbrains/jet/codegen/StackValue.java
index ed881593f5c..ddf5582a1fd 100644
--- a/idea/src/org/jetbrains/jet/codegen/StackValue.java
+++ b/idea/src/org/jetbrains/jet/codegen/StackValue.java
@@ -123,6 +123,12 @@ public abstract class StackValue {
             if (opToken == JetTokens.GT) {
                 opcode = inverse ? Opcodes.IF_ICMPLE : Opcodes.IF_ICMPGT;
             }
+            else if (opToken == JetTokens.LT) {
+                opcode = inverse ? Opcodes.IF_ICMPGE : Opcodes.IF_ICMPLT;
+            }
+            else if (opToken == JetTokens.LTEQ) {
+                opcode = inverse ? Opcodes.IF_ICMPGT : Opcodes.IF_ICMPLE;
+            }
             else {
                 throw new UnsupportedOperationException("don't know how to generate this condjump");
             }
diff --git a/idea/testData/codegen/doWhile.jet b/idea/testData/codegen/doWhile.jet
new file mode 100644
index 00000000000..1ffc78729ef
--- /dev/null
+++ b/idea/testData/codegen/doWhile.jet
@@ -0,0 +1,9 @@
+fun fac(i: Int): Int {
+    var count = 1;
+    var result = 1;
+    do {
+        count = count + 1;
+        result = result * count;
+    } while(count != i);
+    return result;
+}
diff --git a/idea/testData/codegen/while.jet b/idea/testData/codegen/while.jet
index e69de29bb2d..1324c79c0b9 100644
--- a/idea/testData/codegen/while.jet
+++ b/idea/testData/codegen/while.jet
@@ -0,0 +1,9 @@
+fun fac(i: Int): Int {
+    var count = 1;
+    var result = 1;
+    while(count < i) {
+        count = count + 1;
+        result = result * count;
+    }
+    return result;
+}
\ No newline at end of file
diff --git a/idea/tests/org/jetbrains/jet/codegen/NamespaceGenTest.java b/idea/tests/org/jetbrains/jet/codegen/NamespaceGenTest.java
index f7d9e8bb924..e63f177cca8 100644
--- a/idea/tests/org/jetbrains/jet/codegen/NamespaceGenTest.java
+++ b/idea/tests/org/jetbrains/jet/codegen/NamespaceGenTest.java
@@ -12,6 +12,7 @@ import org.objectweb.asm.util.TraceClassVisitor;
 
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 
 /**
@@ -141,6 +142,23 @@ public class NamespaceGenTest extends LightCodeInsightFixtureTestCase {
         assertEquals(false, main.invoke(null, 0));
     }
 
+    public void testWhile() throws Exception {
+        factorialTest("while.jet");
+    }
+
+    public void testDoWhile() throws Exception {
+        factorialTest("doWhile.jet");
+    }
+
+    private void factorialTest(final String name) throws IllegalAccessException, InvocationTargetException {
+        loadFile(name);
+
+        System.out.println(generateToText());
+        final Method main = generateFunction();
+        assertEquals(6, main.invoke(null, 3));
+        assertEquals(120, main.invoke(null, 5));
+    }
+
     private void loadFile(final String name) {
         myFixture.configureByFile(JetParsingTest.getTestDataDir() + "/codegen/" + name);
     }