It looks like the optimization I remember was implemented in gccgo, but maybe they never added it to the main compiler: <a href="http:&#x2F;&#x2F;www.airs.com&#x2F;blog&#x2F;archives&#x2F;277" rel="nofollow">http:&#x2F;&#x2F;www.airs.com&#x2F;blog&#x2F;archives&#x2F;277</a>