llvm dev - May 2017 - MBB reordering vs. MBB fall-through

Hi,

Is it valid for an MBB to not have a final unconditional jump if the jump 
would be to the next MBB anyway? If yes, how is that supposed to interact 
with MBB reordering?

I'm asking because I've encountered a problem with the AVR backend where
an MBB falls through to the wrong MBB due to reordering, and I'd like to 
know if the problem is having fall-throughs in the first place, or not 
communicating their presence somehow with other parts of LLVM.

Thanks,
 	Gergo

On 9 May 2017 at 22:21, Dr. ERDI Gergo via llvm-dev
<llvm-dev at lists.llvm.org> wrote:
> Is it valid for an MBB to not have a final unconditional jump if the jump
> would be to the next MBB anyway? If yes, how is that supposed to interact
> with MBB reordering?
That is valid. Passes that want to reorder basic blocks should only do
so if the AnalyzeBranch and related target hooks (Insert/Remove) allow
it. They're capable of reconstructing the branches so they point to
arbitrary destinations.

Cheers.

Tim.