On Fri, 22 May 2015, Andreas Krebbel wrote: > On 05/22/2015 10:22 AM, Richard Biener wrote: > > On Fri, 22 May 2015, Andreas Krebbel wrote: > > > >> Hi, > >> > >> in order to get the IBM z13 support into present distros the Linux > >> distributors asked me to get this > >> stuff upstream into the older GCC branches first. This would ease the > >> whole backporting efforts, > >> interactions with other patches and would make sure that everybody uses > >> the same code level. > >> > >> This would affect at least the GCC 4.8 and 5 branches but for continuity > >> reasons it probably also > >> should go into 4.9 then. > >> > >> The patchset requires only very minor common code changes and therefore > >> imposes only a low risk for > >> other platforms: > >> > >> recog: Increased max number of alternatives - v2 > >> https://gcc.gnu.org/ml/gcc-patches/2015-05/msg02059.html > > > > On branches you'd have to use unsigned HOST_WIDE_INT (where that might > > be 32bits on some hosts!). We still support hosts without uint64_t > > here. So this might already be a no-go. > > > >> optabs: Fix vec_perm -> V16QI middle end lowering. > >> https://gcc.gnu.org/ml/gcc-patches/2015-05/msg02058.html > >> > >> There is definitely some risk for S/390 but this again should be > >> relatively low when compiling for CPU levels prio to z13. > >> > >> For the z13 support itself I've added a bunch of testcases but I've also > >> run checks with about 10000 automatically generated testcases not part > >> of the patchset. > >> > >> We also ran the ABI comparison testsuite to compare the GCC and LLVM > >> implementations regarding vector data types. > >> > >> Is it ok to apply the patchset to GCC 4.8, 4.9, and 5 branches as well? > > > > I'm somewhat missing the point of backporting z13 support. ppc64le > > enablement was a different story (IBM basically saying ppc64-linux > > is dead), but surely all z13 machines can run non-z13 code just fine. > > > > s390x-linux-gnu is a secondary platform so I don't think we'd want > > to destabilize it (esp. on the 4.8 branch where I expect only one > > more release around the end of June with no chance to fix things up). > > > > So that's a "no" from me basically. But I'm willing to be convinced > > otherwise (not having looked into the z13 backend patches at all). > > Ok. What about GCC 5 branch?
All arguments still apply apart from the fact that we'll have plenty of releases from the GCC 5 branch (and the alternatives patch is safe there). So for GCC 5 I'm willing to leave it to the architecture maintainers, but please wait for other RMs to chime in. Thanks, Richard. > > -Andreas- > > > -- Richard Biener <rguent...@suse.de> SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Dilip Upmanyu, Graham Norton, HRB 21284 (AG Nuernberg)
