[RavSS]

I'd suggest `-Oz` instead, as it optimises for size above all else at the cost of performance, unlike `-Os` which is less aggressive (but likely produces similar code anyway). `-Oz` is somewhat new if I remember correctly, so it depends on the GCC version.

[jcalvinowens]

-Oz and -Os are basically identical with GCC in my experience. LLVM -Os is much less aggressive.

Random example: https://news.ycombinator.com/item?id=39547329