[mysterymath]

The story is a little more complex than that; the semantics were internally consistent, but foot-gun-ey, and they could technically be taken to match GCC's documentation of how they behaved, depending on an unfortunately ambiguous phrase in their docs.

The old semantics also matched GCC's actual behavior; when we brought this up in a GCC issue, those present decided that GCC's behavior was wrong, but the appropriate maintainer couldn't be reached for a final say. The issue is still hung like that.

There were also a few other folks trying to do the same kinds of whole-program call graph analysis this enables, IIRC for GPU purposes. So, there was a lot of conflicting opinions about how this should work, a lot of uncertainty, all the recipe for a big long endless thread.

EDIT: This is of course my extremely biased take on the proceedings. This was also the first and only "open source kerfluffle" I've so far been direct party to; I've seen these come and go on mailing lists before, but I was surprised how different it felt to actually be inside one.