title: defuse.ca online GAS assembler accepts AT&T syntax for movb and movw, but not movl?
body: <p>I'm using <a href="https://defuse.ca/online-x86-assembler.htm#disassembly" rel="nofollow noreferrer">https://defuse.ca/online-x86-assembler.htm#disassembly</a> to assemble x86 instructions to machine code.  (Editor's note: it uses GAS in <code>.intel_syntax noprefix</code> mode.)</p>
  
  <hr>
  
  <p>The below code throws <code>Error: no such instruction: `movl $0xdeadbeef,0x08048c5f'</code></p>
  
  <pre><code>movl $0xdeadbeef,0x08048c5f
  </code></pre>
  
  <p>But the following assembly code works fine</p>
  
  <pre><code>movb $0xdeadbeef, 0x08048c5f
  movw $0xdeadbeef, 0x08048c5f
  </code></pre>