https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102844
--- Comment #20 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Aldy Hernandez from comment #18) > (In reply to rguent...@suse.de from comment #17) > > On Wed, 20 Oct 2021, aldyh at gcc dot gnu.org wrote: > > > > Silly question, why is the SSA form invalid on entry to VRP2? That's just > > > asking for trouble. Is this related to how asserts work? > > > > Well, DOM threading creates invalid SSA (definition not dominating use). > > Doesn't have to do anything with VRP or asserts. > > Ah, I see. > > BTW, if this is still the case in mainline, this is bound to be a problem > for the ranger. Andrew, won't we get an UNDEFINED / unreachable if we query > the non dominating use at this point? Well, invalid IL is invalid - there's no need to "cope" with it. We have to fix the (forward) threading code.
