Optimization and flags for making a static library with g++

Question

I am just starting with g++ compiler on Linux and got some questions on the compiler flags. Here are they

Optimizations

I read about optimizatio

Answer 1

The rule of thumb:

When you need to debug, use -O0 (and -g to generate debugging symbols.)

When you are preparing to ship it, use -O2.

When you use gentoo, use -O3...!

When you need to put it on an embedded system, use -Os (optimize for size, not for efficiency.)