lisp/emacs-lisp/benchmark.el

   1 ;;; benchmark.el --- support for benchmarking code
   2
   3 ;; Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008
   4 ;;   Free Software Foundation, Inc.
   5
   6 ;; Author: Dave Love  <fx@gnu.org>
   7 ;; Keywords: lisp, extensions
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software: you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation, either version 3 of the License, or
  14 ;; (at your option) any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; Utilities for timing the execution of forms, including the time
  27 ;; taken for GC.  Note that prior to timing code you may want to
  28 ;; ensure things like:  there has just been a GC, the relevant code is
  29 ;; already loaded (so that there's no overhead from autoloading etc.),
  30 ;; and the code is compiled if appropriate (but see
  31 ;; `benchmark-run-compiled').
  32
  33 ;;; Code:
  34
  35 (defmacro benchmark-elapse (&rest forms)
  36   "Return the time in seconds elapsed for execution of FORMS."
  37   (let ((t1 (make-symbol "t1"))
  38         (t2 (make-symbol "t2")))
  39     `(let (,t1 ,t2)
  40        (setq ,t1 (current-time))
  41        ,@forms
  42        (setq ,t2 (current-time))
  43        (+ (* (- (car ,t2) (car ,t1)) 65536.0)
  44           (- (nth 1 ,t2) (nth 1 ,t1))
  45           (* (- (nth 2 ,t2) (nth 2 ,t1)) 1.0e-6)))))
  46 (put 'benchmark-elapse 'edebug-form-spec t)
  47 (put 'benchmark-elapse 'lisp-indent-function 0)
  48
  49 ;;;###autoload
  50 (defmacro benchmark-run (&optional repetitions &rest forms)
  51   "Time execution of FORMS.
  52 If REPETITIONS is supplied as a number, run forms that many times,
  53 accounting for the overhead of the resulting loop.  Otherwise run
  54 FORMS once.
  55 Return a list of the total elapsed time for execution, the number of
  56 garbage collections that ran, and the time taken by garbage collection.
  57 See also `benchmark-run-compiled'."
  58   (unless (natnump repetitions)
  59     (setq forms (cons repetitions forms)
  60           repetitions 1))
  61   (let ((i (make-symbol "i"))
  62         (gcs (make-symbol "gcs"))
  63         (gc (make-symbol "gc")))
  64     `(let ((,gc gc-elapsed)
  65            (,gcs gcs-done))
  66        (list ,(if (> repetitions 1)
  67                   ;; Take account of the loop overhead.
  68                   `(- (benchmark-elapse (dotimes (,i ,repetitions)
  69                                           ,@forms))
  70                       (benchmark-elapse (dotimes (,i ,repetitions))))
  71                 `(benchmark-elapse ,@forms))
  72              (- gcs-done ,gcs)
  73              (- gc-elapsed ,gc)))))
  74 (put 'benchmark-run 'edebug-form-spec t)
  75 (put 'benchmark-run 'lisp-indent-function 2)
  76
  77 ;;;###autoload
  78 (defmacro benchmark-run-compiled (&optional repetitions &rest forms)
  79   "Time execution of compiled version of FORMS.
  80 This is like `benchmark-run', but what is timed is a funcall of the
  81 byte code obtained by wrapping FORMS in a `lambda' and compiling the
  82 result.  The overhead of the `lambda's is accounted for."
  83   (unless (natnump repetitions)
  84     (setq forms (cons repetitions forms)
  85           repetitions 1))
  86   (let ((i (make-symbol "i"))
  87         (gcs (make-symbol "gcs"))
  88         (gc (make-symbol "gc"))
  89         (code (byte-compile `(lambda () ,@forms)))
  90         (lambda-code (byte-compile `(lambda ()))))
  91     `(let ((,gc gc-elapsed)
  92            (,gcs gcs-done))
  93        (list ,(if (> repetitions 1)
  94                   ;; Take account of the loop overhead.
  95                   `(- (benchmark-elapse (dotimes (,i ,repetitions)
  96                                           (funcall ,code)))
  97                       (benchmark-elapse (dotimes (,i ,repetitions)
  98                                           (funcall ,lambda-code))))
  99                 `(benchmark-elapse (funcall ,code)))
 100              (- gcs-done ,gcs) (- gc-elapsed ,gc)))))
 101 (put 'benchmark-run-compiled 'edebug-form-spec t)
 102 (put 'benchmark-run-compiled 'lisp-indent-function 2)
 103
 104 ;;;###autoload
 105 (defun benchmark (repetitions form)
 106   "Print the time taken for REPETITIONS executions of FORM.
 107 Interactively, REPETITIONS is taken from the prefix arg.  For
 108 non-interactive use see also `benchmark-run' and
 109 `benchmark-run-compiled'."
 110   (interactive "p\nxForm: ")
 111   (let ((result (eval `(benchmark-run ,repetitions ,form))))
 112     (if (zerop (nth 1 result))
 113         (message "Elapsed time: %fs" (car result))
 114       (message "Elapsed time: %fs (%fs in %d GCs)" (car result)
 115                (nth 2 result) (nth 1 result)))))
 116
 117 (provide 'benchmark)
 118
 119 ;; arch-tag: be570e24-4b51-4784-adf3-fa2b56c31946
 120 ;;; benchmark.el ends here