title: gcc LTO: Limit scope of optimization
body: <p>An LTO build of a rather large shared library (many template instantiations) takes rather long (>10min). Now I know a few things about the library, and could specify some kind of "blacklist" in the form of object files that <em>do not need</em> to be analyzed together (because there are no calls among them that should be inlined or so), or I could specify groups of object files that <em>should</em> be analyzed together. Is this possible somehow (without splitting up the lib)?</p>