Tree tail merging breaks __builtin_unreachable optimization

Michael Matz matz@suse.de
Thu Jul 5 12:44:00 GMT 2012


Hi,

On Wed, 4 Jul 2012, Steven Bosscher wrote:

> On Wed, Jul 4, 2012 at 7:02 PM, Ulrich Weigand <uweigand@de.ibm.com> wrote:
> > Any suggestions how to fix this?  Should tail merging detect
> > __builtin_unreachable and not merge such block?
> 
> That seems to be the most straight-forward thing to do. I don't think
> there are any other passes that do this kind of code merging.

What do we gain by delaying to remove these blocks until RTL?  AFAICS not 
much if anything.  So removing those on the tree level would make more 
sense.


Ciao,
Michael.



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