private void addInstructionCount() {
        int count = cfw.getCurrentCodeOffset() - savedCodeOffset;
        if (count == 0)
            return;
        cfw.addALoad(contextLocal);
        cfw.addPush(count);
        addScriptRuntimeInvoke("addInstructionCount",
                "(Lorg/mozilla/javascript/Context;"
                +"I)V");
    }