On Mon, May 05, 2014 at 07:32:31PM +0200, Richard Biener wrote: > > void_zero_node is used for ubsan too, and survives into gimple. > > I did hit this in real tests, it wasn't just theoretical. > > Ugh - for what does it use that ... :/
It's used like this: t = fold_build3 (COND_EXPR, void_type_node, t, tt, void_zero_node); so if condition T isn't true, nothing should happen. I remember that initially I used something similar to void_zero_node, but that resulted in ICEs. Marek