https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85747
--- Comment #5 from Marc Glisse <glisse at gcc dot gnu.org> --- (In reply to Antony Polukhin from comment #4) > Does providing some kind of -Oon-the-fly switch solves the issue with JIT > compile times while still allows more optimizations for the traditional non > JIT -O2 builds? Not sure what you mean by -Oon-the-fly. If you want to JIT compile the code, you more or less need to embed a compiler in the executable... The closest I can think of is -fprofile-values. It is possible to collect the values of constants during a training run and use them during a second compilation. But then knowing more constants in one compilation than the other may change the code in ways that the PGO framework will not like.