On Tue, Sep 20, 2022 at 9:18 AM Surya Kumari Jangala via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > Hi Jeff, Richard, > Thank you for reviewing the patch! > I have committed the patch to the gcc repo. > Can I backport this patch to prior versions of gcc, as this is an easy patch > to backport and the issue exists in prior versions too?
It doesn't seem to be a regression so I'd error on the safe side here. Richard. > Regards, > Surya > > > On 31/08/22 9:09 pm, Jeff Law via Gcc-patches wrote: > > > > > > On 8/23/2022 5:49 AM, Surya Kumari Jangala via Gcc-patches wrote: > >> sched1: Fix -fcompare-debug issue in schedule_region [PR105586] > >> > >> In schedule_region(), a basic block that does not contain any real insns > >> is not scheduled and the dfa state at the entry of the bb is not copied > >> to the fallthru basic block. However a DEBUG insn is treated as a real > >> insn, and if a bb contains non-real insns and a DEBUG insn, it's dfa > >> state is copied to the fallthru bb. This was resulting in > >> -fcompare-debug failure as the incoming dfa state of the fallthru block > >> is different with -g. We should always copy the dfa state of a bb to > >> it's fallthru bb even if the bb does not contain real insns. > >> > >> 2022-08-22 Surya Kumari Jangala <jskum...@linux.ibm.com> > >> > >> gcc/ > >> PR rtl-optimization/105586 > >> * sched-rgn.cc (schedule_region): Always copy dfa state to > >> fallthru block. > >> > >> gcc/testsuite/ > >> PR rtl-optimization/105586 > >> * gcc.target/powerpc/pr105586.c: New test. > > Interesting. We may have stumbled over this bug internally a little > > while ago -- not from a compare-debug standpoint, but from a "why isn't the > > processor state copied to the fallthru block" point of view. I had it on > > my to investigate list, but hadn't gotten around to it yet. > > > > I think there were requests for ChangeLog updates and a function comment > > for save_state_for_fallthru_edge. OK with those updates. > > > > jeff > >
