Optimizing for space instead of speed in C++

Question

When you say "optimization", people tend to think "speed". But what about embedded systems where speed isn't all that critical, but memory is a major constraint? What are some guidelines, techniques, and tricks that can be used for shaving off those extra kilobytes in ROM and RAM? How does one "profile" code to see where the memory bloat is?

P.S. One could argue that "prematurely" optimizing for space in embedded systems isn't all that evil, because you leave yourself more room for data storage and feature creep. It also allows you to cut hardware production costs because your code can run on smaller ROM/RAM.

P.P.S. References to articles and books are welcome too!

P.P.P.S. These questions are closely related: 404615, 1561629

Answer 1

My experience from an extremely constrained embedded memory environment:

• Use fixed size buffers. Don't use pointers or dynamic allocation because they have too much overhead.
• Use the smallest int data type that works.
• Don't ever use recursion. Always use looping.
• Don't pass lots of function parameters. Use globals instead. :)