https://gcc.gnu.org/bugzilla/show_bug.cgi?id=21111
--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> --- Hmm, I don't remember whether uninit reads invoke undefined behavior, esp. result in a trap representation, but the original testcase doesn't seem to read uninitialized things. For it I suspect that store_bitfield is at fault given it will read possibly uninitialized values for the RMW cycle it performs. So one of the questions is whether we have to / want to preserve any NaT in non-speculated code which means simply clearing NaT everywhere in a mdreorg-like pass? And yes, pass_initialize_regs papers over a lot of issues here but that pass should go away and the fallout fixed since it masks a lot of otherwise latent issues given it only initializes must-undefs. There's a PR for that as well. Jim, if you no longer have access to IA64 HW does it make sense for you to be the port maintainer? Would you be willing to step down and let the port be deprecated for GCC 9 so we can remove it for GCC 10?
