in case you haven't seen my response to blake in this thread, you may want to look for it and read it before what follows

if your compiler inserts hidden blobs that are not present in its source code, then you're not using a free compiler, right? whereas if you start from fully-free tools, whatever you build with them from free sources should also be free.

verifying only comes into play if you wish to take shortcuts by using binaries supplied by third parties that can't be assumed/trusted to be free. and if they can't, and verification involves *not* taking the shortcut, it's not much of a shortcut, is it? :-/