If a function is only called from a single place, consider inlining it.
If a function is called from multiple places, see if it is possible to arrange for the work to be done in a single place, perhaps with flags, and inline that.
If there are multiple versions of a function, consider making a single function with more, possibly defaulted, parameters.
If the work is close to purely functional, with few references to global state, try to make it completely functional.
Try to use const on both parameters and functions when the function really must be used in multiple places.
Minimize control flow complexity and "area under ifs", favoring consistent execution paths and times over "optimally" avoiding unnecessary work."
What I found particularly interesting was: "I now strongly encourage explicit loops for everything, and hope the compiler unrolls it properly". I suppose looking at the generated listing code will always be the final arbiter in whether the compiler does so or not for tiny loops.
"To sum up:
If a function is only called from a single place, consider inlining it.
If a function is called from multiple places, see if it is possible to arrange for the work to be done in a single place, perhaps with flags, and inline that.
If there are multiple versions of a function, consider making a single function with more, possibly defaulted, parameters.
If the work is close to purely functional, with few references to global state, try to make it completely functional.
Try to use const on both parameters and functions when the function really must be used in multiple places.
Minimize control flow complexity and "area under ifs", favoring consistent execution paths and times over "optimally" avoiding unnecessary work."
What I found particularly interesting was: "I now strongly encourage explicit loops for everything, and hope the compiler unrolls it properly". I suppose looking at the generated listing code will always be the final arbiter in whether the compiler does so or not for tiny loops.