lisp/emacs-lisp/benchmark.el

   1 ;;; benchmark.el --- support for benchmarking code
   2
   3 ;; Copyright (C) 2003-2014 Free Software Foundation, Inc.
   4
   5 ;; Author: Dave Love  <fx@gnu.org>
   6 ;; Keywords: lisp, extensions
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; Utilities for timing the execution of forms, including the time
  26 ;; taken for GC.  Note that prior to timing code you may want to
  27 ;; ensure things like:  there has just been a GC, the relevant code is
  28 ;; already loaded (so that there's no overhead from autoloading etc.),
  29 ;; and the code is compiled if appropriate (but see
  30 ;; `benchmark-run-compiled').
  31
  32 ;;; Code:
  33
  34 (defmacro benchmark-elapse (&rest forms)
  35   "Return the time in seconds elapsed for execution of FORMS."
  36   (let ((t1 (make-symbol "t1"))
  37         (t2 (make-symbol "t2")))
  38     `(let (,t1 ,t2)
  39        (setq ,t1 (current-time))
  40        ,@forms
  41        (setq ,t2 (current-time))
  42        (float-time (time-subtract ,t2 ,t1)))))
  43
  44 (put 'benchmark-elapse 'edebug-form-spec t)
  45 (put 'benchmark-elapse 'lisp-indent-function 0)
  46
  47 ;;;###autoload
  48 (defmacro benchmark-run (&optional repetitions &rest forms)
  49   "Time execution of FORMS.
  50 If REPETITIONS is supplied as a number, run forms that many times,
  51 accounting for the overhead of the resulting loop.  Otherwise run
  52 FORMS once.
  53 Return a list of the total elapsed time for execution, the number of
  54 garbage collections that ran, and the time taken by garbage collection.
  55 See also `benchmark-run-compiled'."
  56   (declare (indent 1) (debug t))
  57   (unless (natnump repetitions)
  58     (setq forms (cons repetitions forms)
  59           repetitions 1))
  60   (let ((i (make-symbol "i"))
  61         (gcs (make-symbol "gcs"))
  62         (gc (make-symbol "gc")))
  63     `(let ((,gc gc-elapsed)
  64            (,gcs gcs-done))
  65        (list ,(if (> repetitions 1)
  66                   ;; Take account of the loop overhead.
  67                   `(- (benchmark-elapse (dotimes (,i ,repetitions)
  68                                           ,@forms))
  69                       (benchmark-elapse (dotimes (,i ,repetitions))))
  70                 `(benchmark-elapse ,@forms))
  71              (- gcs-done ,gcs)
  72              (- gc-elapsed ,gc)))))
  73
  74 ;;;###autoload
  75 (defmacro benchmark-run-compiled (&optional repetitions &rest forms)
  76   "Time execution of compiled version of FORMS.
  77 This is like `benchmark-run', but what is timed is a funcall of the
  78 byte code obtained by wrapping FORMS in a `lambda' and compiling the
  79 result.  The overhead of the `lambda's is accounted for."
  80   (declare (indent 1) (debug t))
  81   (unless (natnump repetitions)
  82     (setq forms (cons repetitions forms)
  83           repetitions 1))
  84   (let ((i (make-symbol "i"))
  85         (gcs (make-symbol "gcs"))
  86         (gc (make-symbol "gc"))
  87         (code (byte-compile `(lambda () ,@forms)))
  88         (lambda-code (byte-compile `(lambda ()))))
  89     `(let ((,gc gc-elapsed)
  90            (,gcs gcs-done))
  91        (list ,(if (> repetitions 1)
  92                   ;; Take account of the loop overhead.
  93                   `(- (benchmark-elapse (dotimes (,i ,repetitions)
  94                                           (funcall ,code)))
  95                       (benchmark-elapse (dotimes (,i ,repetitions)
  96                                           (funcall ,lambda-code))))
  97                 `(benchmark-elapse (funcall ,code)))
  98              (- gcs-done ,gcs) (- gc-elapsed ,gc)))))
  99
 100 ;;;###autoload
 101 (defun benchmark (repetitions form)
 102   "Print the time taken for REPETITIONS executions of FORM.
 103 Interactively, REPETITIONS is taken from the prefix arg.
 104 For non-interactive use see also `benchmark-run' and
 105 `benchmark-run-compiled'."
 106   (interactive "p\nxForm: ")
 107   (let ((result (eval `(benchmark-run ,repetitions ,form))))
 108     (if (zerop (nth 1 result))
 109         (message "Elapsed time: %fs" (car result))
 110       (message "Elapsed time: %fs (%fs in %d GCs)" (car result)
 111                (nth 2 result) (nth 1 result)))))
 112
 113 (provide 'benchmark)
 114
 115 ;;; benchmark.el ends here