title: How to create a GNU GAS macro that expands to an expression like "(x+y*240)*2"?
body: <p>I'm building a program for ARM Linux using GAS, but I want to do some macros to make my development some more smart. Then I want to know:</p>
  
  <p>How could I do a macro for this: <code>(x+y*240)*2</code>, were <code>x</code> and <code>y</code> are <code>int</code>, that will be used like this:</p>
  
  <pre><code>mov r0, MACRO_SHOULD_BE_CALLED_HERE
  </code></pre>
  
  <p>And how could I do a macro that should be called like this:</p>
  
  <pre><code>JUST_MACRO_CALLED_HERE_TO_DO_SOMETHING
  </code></pre>
  
  <p>That will just do something that is already defined inside it, like a print function for example.</p>
  
  <p>Also, if I need some arguments on the macro or a function call. How I could do it?</p>
  
  <p><em>PS: <code>r0</code> is an ARM register, like <code>eax</code> of x86</em></p>