why formatting an int as 6*1000*1000 and not 6000000 [duplicate]

Question

I was reading a code of a middleware that is written in c and in the code they wrote the following:

usleep(6*1000*1000);

So my question is:

Is there a reason behind writing it like this? why not just write 6000000? Doing this multiplication has any effect on the performance of the program?

Answer 1

usleep() expects the supplied argument to be in "microseconds".

This is a visual transformation of the microsecond to seconds, no impact on code expected as any half-decent compiler will compute that at compile time.

Answer 2

It just makes the source easier to read. With the multiplication, the number is obviously 6 million.

As it evaluates to a constant, the compiler will evaluate the constant at compile-time and there will be no difference in the compiled code.