Comment by bob1029
1 year ago
This gets even more complex once you start looking at dynamic compilations. Some of the JIT compilers have the ability to hot patch functions based upon runtime statistics. In very large, enterprisey applications with unknowns regarding how they will actually be used at build time, this can make a difference.
You can go nuclear option with your static compilations and turn on all the optimizations everywhere, but this kills inner loop iteration speed. I believe there are aspects of some dynamic compiling runtimes that can make them superior to static compilations - even if we don't care how long the build takes.
Statistics aren't magic and it's not going to find superoptimizing cases like this by using them. I think this is only helpful when you get a lot of incoming poorly written/dynamic code needing a lot of inlining, that maybe just got generated in the first place. So basically serving ads on websites.
In ffmpeg's case you can just always be the correct thing.