Question

in computer literature it is generally recommended to write short functions as much as possible. I understand it may increase readability (although not always), and such approach also provides more flexibility. But does it have something to do with optimization as well? I mean — does it matter to a compiler to compile a bunch of small routines rather than a few large routines?

Thanks.

Answer 1

That depends on the compiler. Many older compilers only optimized a single function at a time, so writing larger functions (up to to some limit) could improve optimization — but (with most of them) exceeding that limit turned optimization off completely.

Most reasonably current compilers can generate inline code for functions (and C99 added the ineline keyword to facilitate that) and do global (cross-function) optimization, in which case it normally makes no difference at all.