</p>


<h3 id="advice">Advice</h3>

<p>
Programs that modify data being simultaneously accessed by multiple goroutines
must serialize such access.
</p>

<p>
To serialize access, protect the data with channel operations or other synchronization primitives
such as those in the <a href="/pkg/sync/"><code>sync</code></a>
and <a href="/pkg/sync/atomic/"><code>sync/atomic</code></a> packages.
</p>

<p>

		if c == r {
			return i
		}
	}
	// invalid: missing return statement
}
</pre>

<p>
A function declaration may omit the body. Such a declaration provides the
signature for a function implemented outside Go, such as an assembly routine.
</p>

<pre>
func min(x int, y int) int {
	if x &lt; y {
		return x
	}
	return y
}

</p>

<h3 id="symbols">Symbols</h3>

<p>
Some symbols, such as <code>R1</code> or <code>LR</code>,
are predefined and refer to registers.
The exact set depends on the architecture.
</p>

<p>
There are four predeclared symbols that refer to pseudo-registers.
These are not real registers, but rather virtual registers maintained by
the toolchain, such as a frame pointer.

	if x < y {
		return x
	}
	return y
}
</pre>

<p>
A function declaration without type parameters may omit the body.
Such a declaration provides the signature for a function implemented outside Go,
such as an assembly routine.
</p>

<pre>
func flushICache(begin, end uintptr)  // implemented externally
</pre>

<h3 id="Method_declarations">Method declarations</h3>