https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112806
--- Comment #3 from Alexander Zaitsev <zamazan4ik at tut dot by> --- > https://gcc.gnu.org/onlinedocs/gcc-13.2.0/gcc/Other-Builtins.html#index-fprofile-arcs-1 I already read this and still do not understand the actual behavior. If PGO profiles show that the branch is "cold" but a user write for this branch via __builtin_expect/[[likely]] that the branch is "hot" - what decision will be made by the optimizer? On the link above there is only "In general, you should prefer to use actual profile feedback for this (-fprofile-arcs), as programmers are notoriously bad at predicting how their programs actually perform.". But it does not specify the actual behavior - it's just a recommendation to use PGO instead of manual [[likely]] hints.
