https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96015
--- Comment #33 from Jeffrey A. Law <law at redhat dot com> --- Have I mentioned before that I think __builtin_unreachable is fundamentally broken/wrong :-) I could argue that the BARRIER in the IL is wrong because it doesn't actually line up with the semantics of the instruction stream. But that's probably a losing battle with those who think that __builtin_unreachable's current behavior is sensible. One thought would be to turn a conditional jump followed by a barrier into an unconditional jump in jump.c. But I fear that just papers over the problem and that we'd see the same issue raise its head again in a slightly perturbed form that wasn't recognized by jump.c, but tripped the same code as we have now in reorg.c. Another thought would be to detect this in relax_delay_slots and twiddle the transformation to avoid the problematic behavior. I think we could detect just by seeing if there's a barrier after INSN in the same hunk of code that Eric quoted and changing the behavior slightly when that's detected. I hate special casing things like that and there's a reasonable chance other parts of GCC are affected by the same problem. That may argue for implementing both approaches. But I'd really just like to change how __builtin_unreachable works. Eric, thoughts? jeff
