https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65233
--- Comment #19 from Jeffrey A. Law <law at redhat dot com> --- Right. That's the last step for updating the CFG for a series of jump threads. It's certainly the case that the redirections can leave unreachable blocks. But the first thing that the cfg cleanup routines ought to be doing is removing those unreachable blocks -- before we call any of the block merging code. That happens in cleanup_tree_cfg_noloop. So I'd be real interested to know if we have any unreachable blocks in the CFG after cleanup_tree_cfg_noloop has completed.
