Static linking vs dynamic linking?

Question

Are there any compelling performance reasons to choose static linking over dynamic linking or vice versa in certain situations? I've heard or read the following, but I don't know enough on the subject to vouch for its veracity.1) The difference in runtime performance between static linking and dynamic linking is usually negligible.2) (1) is not true if using a profiling compiler that uses profile data to optimize program hotpaths because with static linking, the compiler can optimize both your code and the library code. With dynamic linking only your code can be optimized. If most of the time is spent running library code, this can make a big difference. Otherwise, (1) still applies.

Answer 1

The difference in runtime performance is often negligible. When choosing whether to statically or dynamically link an executable, there are often other trade-offs you're interested in. For example, if you're deploying an application diverse environments, eg many versions of an OS, you may want to statically link your executable, so you can deploy the compatible libraries with it. As for performance, if the performance critical section of code relies on many library calls, you may want to statically link the binary, then re-order blocks of code in order to increase performance. This is what you're referring to in (2). In general, indirection is expensive, the example (2) points this out.