Emacs Lisp: Benchmark, Test Speed

benchmark-run

(benchmark-run &optional REPETITIONS &rest FORMS)

Time execution of FORMS.

If REPETITIONS is supplied as a number, run FORMS that many times, accounting for the overhead of the resulting loop. Otherwise run FORMS once.

Return a list of the total elapsed time for execution, the number of garbage collections that ran, and the time taken by garbage collection. See also benchmark-run-compiled .

;; -*- coding: utf-8; lexical-binding: t; -*-
;; 2023-08-07
;; comparing speed of compiled code

(require 'benchmark)

(defun xtest (n)
  "Return the time, in seconds, to run N iterations of a loop."
  (while (> (setq n (1- n)) 0))
  n
  )

(setq xi (expt 10 7))

(benchmark-run 1 (xtest xi))
;; (0.7 0 0.0)

;; using benchmark-run-compiled does not make a difference. strange
(benchmark-run-compiled 1 (xtest xi))
;; (0.6 0 0.0)

;; actually compile the code make a difference
(byte-compile 'xtest)
(benchmark-run 1 (xtest xi))
;; (0.1 0 0.0)

;; bytecompiled code is some 7 times faster in this example

;; -*- coding: utf-8; lexical-binding: t; -*-
;; 2023-08-02 2023-08-07
;; comparing speed of ways to get current word

(require 'benchmark)

(setq xi 100000)

(benchmark-run xi (current-word))
;; some
;; (0.19 7 0.15)

(benchmark-run xi (xah-get-thing-at-point 'word))
;; some
;; (0.55 14 0.33)

;; byte compiled version
(benchmark-run xi (xah-get-thing-at-point 'word))
;; some
;; (0.24 5 0.11)

(benchmark-run xi (thing-at-point 'word))
;; some
;; (1.1 28 0.6)

;; -*- coding: utf-8; lexical-binding: t; -*-
;; 2023-08-02
;; comparing speed of diff ways of checking the char before cursor is any of whitespace

(require 'benchmark)

(setq xi (expt 10 6))

(benchmark-run xi
  (progn
    (or
     (eq (char-before) 32)
     (eq (char-before) 9)
     (eq (char-before) 10))))
;; (0.21 0 0.0)

(benchmark-run xi
  (if (eq (point-min) (point))
      nil
    (prog2
        (backward-char)
        (looking-at "[ \t\n]")
      (forward-char))))
;; (0.43 0 0.0)

(benchmark-run xi
  (string-match "[ \t\n]" (char-to-string (char-before))))
;; (0.73 20 0.47)

(benchmark-run xi (looking-back "[ \t\n]"))
;; (1.5 43 1.0)

(benchmark-run xi (looking-back "[ \t\n]" (1- (point))))
;; (1.6 42 1.0)

(benchmark-run 1 (xahsite-update-search))
;; (15.871795 34 0.7105949999999996)
;; (15.694725 35 0.7229780000000003)