https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90418
--- Comment #5 from Iain Sandoe <iains at gcc dot gnu.org> --- (In reply to Iain Sandoe from comment #4) > (In reply to Jakub Jelinek from comment #3) > > (In reply to Iain Sandoe from comment #2) > > > (In reply to Jakub Jelinek from comment #1) > > > Though, I don't understand why that > > if (DEFAULT_ABI == ABI_DARWIN && crtl->calls_eh_return) return false; > > wouldn't work in rs6000_function_ok_for_sibcall, because that conditional > > should make sure we don't have any tail calls in such functions and thus the > > above shouldn't trigger. > > Agreed, and that's exactly the code I have present, and I just did a clean > build. However, as you suspect the sibcall is still present. Perhaps > crtl->calls_eh_return is not somehow set or somehow a sib call is generated > without checking it's OK. Will look more later. Hm. So it seems that the problem is in expand - the call to rs6000_function_ok_for_sibcall() occurs when the tail call is encountered, but that is before the call to expand_eh_return() - which sets crtl->calls_eh_return. If I jam sibcalls off completely, of course, it works. Trying the posted patch for gcc/tree-tailcall.c
