Timer support

[awvwgk]

Support for measuring timings, having timer ranges and pretty printing of time printout would be a useful addition. This is especially helpful for comparing implementation without relying on external tools.

[ivan-pi]

Some time ago I prototyped some fypp macros for benchmarking. Not sure if they really offer any advantage vs subroutines/functions, but I think I was trying to emulate what Julia has. If I recall correctly Julia timer macros will adjust the number of calls automatically to obtain a decent sample, and then calculate some basic statistics (mean, variance).

A few more links to other timer packages can be found here: fortran-lang/benchmarks#6
The most complete one I've seen is the NIST StopWatch package but it would need a modern update.

On the other hand something more minimalistic could also be useful.

[nncarlson]

Another timer implementation here.

[urbanjost]

https://github.com/urbanjost/M_stopwatch is a version of StopWatch as an fpm package as well; albeit I use vendor utilities or gprof(1) myself for optimizing, sometimes I want an embedded timer. I found the dynamic loader module particularly interesting at the previously mentioned site; those are nicely done and look like they would be nice additions to the fpm(1) registry. At a minimum those should be added to the Fortran Wiki site.

[trippalamb]

I might be missing something, but does the System_Clock() internal not already support this basic functionality?