On 5/14/19 4:57 PM, Jakub Jelinek wrote: > On Tue, May 14, 2019 at 01:08:27PM -0600, Jeff Law 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), the targets which we expect to >>> fail currently or even have a proof of that can just punt. >> I would go with a patch that got the info set earlier and just punt in >> the generic code. I just don't see this case as terribly important to >> optimize. > > So like this? Bootstrapped/regtested on x86_64-linux and i686-linux, > verified _Unwind_Resume_or_Rethrow no longer has a tail call. > > 2019-05-14 Jakub Jelinek <ja...@redhat.com> > > PR c++/59813 > PR target/90418 > * function.h (struct function): Add calls_eh_return member. > * gimplify.c (gimplify_call_expr): Set cfun->calls_eh_return when > gimplifying __builtin_eh_return call. > * tree-inline.c (initialize_cfun): Copy calls_eh_return from src_cfun > to cfun. > (expand_call_inline): Or in src_cfun->calls_eh_return into > dst_cfun->calls_eh_return. > * tree-tailcall.c (suitable_for_tail_call_opt_p): Return false if > cfun->calls_eh_return. > * lto-streamer-in.c (input_struct_function_base): Read calls_eh_return. > * lto-streamer-out.c (output_struct_function_base): Write > calls_eh_return. Yea, this is how I envisioned it working. I think we should just run with this.
Jeff
