Hi, On Thu, 5 Jul 2012, Richard Guenther wrote:
> >> On Wed, Jul 4, 2012 at 7:02 PM, Ulrich Weigand <uweig...@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. > > The gain is to derive assertions from the conditional guarding these > blocks and optimize using that knowledge. I know that we derive assertions, but that's no reason why we couldn't remove the BBs (or move it's sideeffects) in e.g. pass_fold_builtins. It runs late enough that we don't make use of assertions afterwards. Ciao, Michael.