One piece of advice I've heard is to benchmark your app under -Os compared to -O2 or higher. The idea is that in these days, cache misses are king, so smaller

One piece of advice I've heard is to benchmark your app under -Os compared to -O2 or higher. The idea is that in these days, cache misses are king, so smaller code means fewer misses. Of course, you need a real-world load, test on correct CPU architecture for your problem etc.