kcov vs lcov vs raw performance?

Question

Anyone able to give me some info on the relative performance of code running under following conditions,

1. Just compiled
2. Compiled with --coverage
3. Running under kcov

Am I going to need twice a long to run my test suite if I integrated code coverage tool like gcov or kcov?

Answer 1

My experience with this is as follows but note that actual results will probably depend heavily on your code.

• Running with compiled '--coverage' is about half the speed of just compiled code.

• Running with kcov is significantly (x6 - x10) times slower than just compiled code.

So what I'm doing is:

• For a lot of runs or something that I know takes sometime, use '--coverage' then gcovr/lcov
• For a one-off run of a shortish executable, use kcov.