On Sat, Sep 24, 2022 at 1:37 PM Jeff Law <jeffreya...@gmail.com> wrote: > > > On 9/21/22 16:11, H.J. Lu wrote: > > On Wed, Sep 7, 2022 at 10:03 AM Jeff Law via Gcc-patches > > <gcc-patches@gcc.gnu.org> wrote: > >> > >> > >> On 9/2/2022 8:36 AM, H.J. Lu via Gcc-patches wrote: > >>> CONCAT and CONCATN never appear in the insn chain. They are only used > >>> in debug insn. Ignore debug insns with CONCAT and CONCATN for insn > >>> scheduling to avoid different insn orders with and without debug insn. > >>> > >>> gcc/ > >>> > >>> PR rtl-optimization/106746 > >>> * sched-deps.cc (sched_analyze_2): Ignore debug insns with CONCAT > >>> and CONCATN. > >> Shouldn't we be ignoring everything in a debug insn? I don't see why > >> CONCAT/CONCATN are special here. > > Debug insns are processed by insn scheduling. I think it is to improve > > debug > > experiences. It is just that there are no matching usages of CONCAT/CONCATN > > in non-debug insns. > > But from a dependency standpoint ISTM all debug insn can be ignored. I > still don't see why concat/concatn should be special here. >
I tried to ignore everything in a debug insn. It caused many regressions in the GCC testsuite. -- H.J.
