https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81614
--- Comment #5 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to Cody Gray from comment #3) > > Also, it is hard to confirm tuning PRs without hard benchmark data. > > No, it really isn't. I know that's a canned response, likely brought about > by hard-won experience with a lot of dubious "tuning" feature requests, but > it's just a cop-out in this case, if not outright dismissive. Partial > register stalls are a well-documented phenomenon, confirmed by multiple > sources, and have been a significant source of performance degradation since > the Pentium Pro was released circa 1995. Well, then please find some representative benchmark suite and test the effect of -mtune-ctrl=partial_reg_stall on your target. There are plenty of benchmarks listed at [1]. It is an one-line change in the compiler source to set the new default then. [1] https://gcc.opensuse.org/specs/cxx_groups
