On Fri, Apr 30, 2021 at 3:31 PM Jonathan Wakely <jwak...@redhat.com> wrote: > > On 29/04/21 16:06 -0400, David Edelsohn wrote: > >On Fri, Jan 8, 2021 at 1:37 PM Jonathan Wakely <jwak...@redhat.com> wrote: > >> > >> On 06/01/21 19:41 -0500, David Edelsohn wrote: > >> >Thanks for clarifying the issue. > >> > > >> >As you implicitly point out, GCC knows the type of INT64 and defines > >> >the macro __INT64_TYPE__ . The revised code can use that directly, > >> >such as: > >> > > >> >#if defined(_GLIBCXX_HAVE_INT64_T_LONG) \ > >> > || defined(_GLIBCXX_HAVE_INT64_T_LONG_LONG) > >> > typedef __INT64_TYPE__ streamoff; > >> > #elif defined(_GLIBCXX_HAVE_INT64_T) > >> > typedef int64_t streamoff; > >> > #else > >> > typedef long long streamoff; > >> > #endif > >> > > >> >Are there any additional issues not addressed by that approach, other > >> >than possible further simplification? > >> > >> That avoids the ABI break that Jakub pointed out. But I think we can > >> simplify it further, as in the attached patch. > >> > >> This uses __INT64_TYPE__ if that's defined, and long long otherwise. I > >> think that should be equivalent in all practical cases (I can imagine > >> some strange target where __INT64_TYPE__ is defined by the compiler, > >> but int64_t isn't defined when the configure checks look for it, and > >> so the current code would use long long and with my patch would use > >> __INT64_TYPE__ which could be long ... but I think in practice that's > >> unlikely. It was probably more likely in older releases where the > >> configure test would have been done with -std=gnu++98 and so int64_t > >> might not have been declared by libc's <stdint.h>, but if that was the > >> case then any ABI break it caused happened years ago. > > > >Hi, Jonathan > > > >Polite ping. > > > >Now that GCC 11.1 has been released, can this patch be applied to > >libstdc++? As I replied at the time to Jakub's concerns, both Clang > >(since 3.0.0) and ICC (since at least 16.0.0) have defined > >__INT64_TYPE__ . > > Pushed to trunk after testing on x86_64-linux and powerpc-aix.
Hi, Jonathan Thanks very much! It's very helpful to remove the multilib differences. I'll follow up about the int128 change in a separate email. Thanks, David
