diff -r 000000000000 -r 4dea14fafc31 rt/vm/src/main/java/org/apidesign/vm4brwsr/NumberOperations.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rt/vm/src/main/java/org/apidesign/vm4brwsr/NumberOperations.java	Mon Jan 25 08:14:42 2016 +0100
@@ -0,0 +1,86 @@
+/**
+ * Back 2 Browser Bytecode Translator
+ * Copyright (C) 2012-2015 Jaroslav Tulach <jaroslav.tulach@apidesign.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ * This program 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 for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. Look for COPYING file in the top folder.
+ * If not, see http://opensource.org/licenses/GPL-2.0.
+ */
+package org.apidesign.vm4brwsr;
+
+final class NumberOperations {
+    private static final int DIV32 = 1;
+    private static final int MOD32 = 2;
+    private static final int MUL32 = 4;
+
+    private int used;
+
+    public String mul32() {
+        used |= MUL32;
+        return "__mul32(@1,@2)";
+    }
+    public String div32() {
+        used |= DIV32;
+        return "__div32(@1,@2)";
+    }
+
+    public String mod32() {
+        used |= MOD32;
+        return "__mod32(@1,@2)";
+    }
+
+    public String generate() {
+        if (used == 0) {
+            return "";
+        }
+        StringBuilder sb = new StringBuilder();
+        if ((used & MUL32) != 0) {
+            sb.append(
+                "    __mul32 = function(x, y) {\n" +
+                "        return (((x * (y >> 16)) << 16) + x * (y & 0xFFFF)) | 0;\n" +
+                "    };\n" +
+                ""
+            );
+        }
+        if ((used & (MOD32 | DIV32)) != 0) {
+            sb.append(
+                "    function __handleDivByZero() {\n" +
+                "        var exception = new vm.java_lang_ArithmeticException;\n" +
+                "        vm.java_lang_ArithmeticException(false).constructor\n" +
+                "          .cons__VLjava_lang_String_2.call(exception, \"/ by zero\");\n" +
+                "\n" +
+                "        throw exception;\n" +
+                "    }\n" +
+                ""
+            );
+        }
+        if ((used & MOD32) != 0) {
+            sb.append(
+                "    function __mod32(x, y) {\n" +
+                "        if (y === 0) __handleDivByZero();\n" +
+                "        return (x % y) | 0;\n" +
+                "    }\n" +
+                ""
+            );
+        }
+        if ((used & DIV32) != 0) {
+            sb.append(
+                "    function __div32(x, y) {\n" +
+                "        if (y === 0) __handleDivByZero();\n" +
+                "        return (x / y) | 0;\n" +
+                "    }\n" +
+                ""
+            );
+        }
+        return sb.toString();
+    }
+}