Timer to find elapsed time in a function call in C

Question

I want to calculate time elapsed during a function call in C, to the precision of 1 nanosecond.

Is there a timer function available in C to do it?

If yes ple

Answer 1

Any timer functionality is going to have to be platform-specific, especially with that precision requirement.

The standard solution in POSIX systems is gettimeofday(), but it has only microsecond precision.

If this is for performance benchmarking, the standard way is to make the code under test take enough time to make the precision requirement less severe. In other words, run your test code for a whole second (or more).