[llvm] r296535 - Fix PR 24415 (at least), by making our post-dominator tree behavior sane.

[Michael Kruse via llvm-commits]

2017-03-13 20:43 GMT+01:00 Daniel Berlin via llvm-commits
<llvm-commits at lists.llvm.org>:
> As another analysis example, this will break the linear time reverse IDF
> calculation. It already does (and adce tries to work around that now), but
> it will so even more :)

How can that be? All Tobias' suggestion does it adding a phantom edge.
The most number of edges it could add is the number of blocks.  If IDF
is linear, let's say in the number of edges, then this would just add
a constant per additional edge, or something linear in the number of
blocks.

Michael