https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112717
--- Comment #3 from Alexander Zaitsev <zamazan4ik at tut dot by> --- > I thought this was documented but I don't see. There is no guarantee for > forward or backwards compatibility at all. In fact iirc there is a version > stored in the files to make sure the correct version is used with the version > of tools/compiler. Could we add this information to the documentation? Would be really helpful to the users to know this detail. Since your answer am I right that right now it's a strong recommendation/requirement to regenerate PGO profiles with each GCC update?