<a href="/pkg/os/exec#Cmd.Start"><code>Cmd.Start</code></a> no
      longer call <code>LookPath</code> if the path to the executable is already
      absolute and has an executable file extension. In addition,
      <code>Cmd.Start</code> no longer writes the resolved extension back to
      the <a href="/pkg/os/exec#Cmd.Path"><code>Path</code></a> field,

</p>

<p>
The architectures share syntax for common addressing modes such as
<code>(R1)</code> (register indirect),
<code>4(R1)</code> (register indirect with offset), and
<code>$foo(SB)</code> (absolute address).
The assembler also supports some (not necessarily all) addressing modes
specific to each architecture.
The sections below list these.
</p>

<p>