Hi, On Tue, 14 May 2019, Jakub Jelinek wrote:
> In https://gcc.gnu.org/ml/gcc-patches/2019-05/msg00484.html I've posted > a patch that would set it earlier (or it could be set during > gimplification and propagated during inlining, would need to be in > cfun->calls_eh_return instead of crtl->calls_eh_return) and then targets > for which we do not want to bother with it or where it is not beneficial > to have tail calls in functions that call __builtin_eh_return (as I said > in the thread, e.g. on x86_64-linux it is both smaller and faster), I really think you're over-obsessing with the optimization in this case. Given the general slowness of DWARF CFI interpretation (which always happens before eh_return) any optimization re tail-calls in any of _Unwind_RaiseException _Unwind_ForcedUnwind _Unwind_Resume or _Unwind_Resume_or_Rethrow (of which only the latter looks amenable) seems a bit silly. Disable tail-calls whenever builtin_eh_return is seen in the gimplifier (in all four functions in the world!), and be done. Ciao, Michael.
