https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93564
--- Comment #1 from Vladimir Makarov <vmakarov at gcc dot gnu.org> --- Thank your for reporting this. I've changed RA heuristics. It is very rare case when you change heuristics and there is no one SPEC benchmark with performance degradation. Usually some benchmarks improve, some ones worsen. We should look at the overall rate. According to the overall CPU2017 rate I see 6.514 before my patch and 6.503 after. It is 0,17% change which is in error measure range. I've got analogous data on SPEC2000 when I tried my patch (actually the rate with the patch was better). For CPU2006 I see 50.337 before the patch and 50.107 after which is close to 0.4% degradation. This is pretty high. I will investigate what can I do to improve the heuristics but it will take some time. If nothing works probably we should revert my patch and reopen 2 PRs which it closed.
