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?
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 >
