https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125305
--- Comment #5 from Xi Ruoyao <xry111 at gcc dot gnu.org> --- I can still observe performance gain from scheduling on LA664 for e.g. https://git.kernel.org/torvalds/c/9805f39d423a. AArch64 is even using 10 for TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD (when tuning for a core with such an issue rate) but they disable early scheduling at -O2 and only enable it at -O3 by default (they once disabled it at all but then lbm regressed for 6% on neoverse, again demonstrating the usefulness of scheduling even on OoO core). x86 disables early scheduling by default for any optimization level. IMO we should try disabling early scheduling for OoO cores like AArch64 or x86 instead of modifying the lookahead, so the people requiring "top performance" can still bring it back with -fschedule-insns. And I think we need some benchmark results to make the decision.
