[commonqt-devel] Microbenchmarks

[David Lichteblau]

Hi,

I've added the existing microbenchmark code to the "test" directory of
the repository, and cleaned it up a little.

(This infrastructure is best benchmark operations in the microsecond to
millisecond range.  Real-world "macrobenchmarks" should probably be done
differently.)

The instructions are at the top:

;;;; Evaluate
;;;;   (qt::microbench)
;;;; to run these benchmarks on an otherwise idle computer.  Results are
;;;; written to the REPL, and in a machine readable format also dribbled
;;;; to files.  Files names are, by default, of the form <lisp
;;;; implementation type>.txt.
;;;;
;;;; Notes:
;;;;  1. These are microbenchmarks meant to aid understanding of the
;;;;     implementation.  They do not necessarily reflect overall or
;;;;     real-world performance.
;;;;  2. Since each individual operation is too fast to benchmark, we
;;;;     invoke them a large number of times and compute the average run
;;;;     time afterwards.
;;;;  3. Before running benchmarks, we choose a repetition time depending
;;;;     on how fast (or slow) a simple test case is, so that slow Lisps
;;;;     don't waste endless time running benchmarks.
;;;;  4. Benchmarks are run three times, and only the best run of those
;;;;     three is reported, to account for issues with background activity
;;;;     on the computer ruining the results.
;;;;  5. But you should _still_ run the overall benchmarks several times
;;;;     and see how reproducible the numbers are.
;;;;
;;;; There's no tool to parse the output files and drawn graphs yet, but
;;;; there should be.  (READ-MICROBENCH-RESULTS already fetches the raw
;;;; sexps from each file though, just to check that they are READable).


d.