Byte

idea/src/org/jetbrains/jet/codegen/ExpressionCodegen.java

@@ -471,7 +471,8 @@ public class ExpressionCodegen extends JetVisitor {
             DeclarationDescriptor cls = op.getContainingDeclaration();
             if (cls instanceof ClassDescriptor) {
                 final String className = cls.getName();
-                if (className.equals("Int") || className.equals("Long") || className.equals("Short")) {
+                if (className.equals("Int") || className.equals("Long") || className.equals("Short") ||
+                    className.equals("Byte")) {
                     if (op.getName().equals("compareTo")) {
                         generateCompareOp(expression, opToken);
                     }

idea/src/org/jetbrains/jet/codegen/JetTypeMapper.java

@@ -26,6 +26,9 @@ public class JetTypeMapper {
         if (jetType.equals(standardLibrary.getShortType())) {
             return Type.SHORT_TYPE;
         }
+        if (jetType.equals(standardLibrary.getByteType())) {
+            return Type.BYTE_TYPE;
+        }
         if (jetType.equals(standardLibrary.getBooleanType())) {
             return Type.BOOLEAN_TYPE;
         }

idea/tests/org/jetbrains/jet/codegen/NamespaceGenTest.java

@@ -242,6 +242,11 @@ public class NamespaceGenTest extends LightCodeInsightFixtureTestCase {
                 Short.valueOf((short) 32767), Short.valueOf((short) 32767), 65534);
     }
 
+    public void testByte() throws Exception {
+        binOpTest("fun foo(a: Byte, b: Byte): Int = a + b",
+                Byte.valueOf((byte) 127), Byte.valueOf((byte) 127), 254);
+    }
+
     private void binOpTest(final String text, final Object arg1, final Object arg2, final int expected) throws Exception {
         loadText(text);
         System.out.println(generateToText());