(benchmark-run-compiled): Make it work like 'benchmark-run' again

* lisp/emacs-lisp/benchmark.el (benchmark-run): Add special case for
nil repetitions.

3 files changed, 17 insertions, 10 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 04774c13e55..fd1d04b8a04 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -326,6 +326,7 @@ names" in the Tramp manual for full documentation of these facilities.
 
 * Incompatible Lisp Changes in Emacs 27.1
 
+** The 'repetitions' argument of 'benchmark-run' can now also be a variable.
 ** The FILENAME argument to 'file-name-base' is now mandatory and no
 longer defaults to 'buffer-file-name'.
 
diff --git a/lisp/emacs-lisp/benchmark.el b/lisp/emacs-lisp/benchmark.el
index 2f4e38fe356..e062a1867a8 100644
--- a/lisp/emacs-lisp/benchmark.el
+++ b/lisp/emacs-lisp/benchmark.el
@@ -50,7 +50,7 @@ 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'."
   (declare (indent 1) (debug t))
-  (unless (or (natnump repetitions) (symbolp repetitions))
+  (unless (or (natnump repetitions) (and repetitions (symbolp repetitions)))
     (setq forms (cons repetitions forms)
           repetitions 1))
   (let ((i (make-symbol "i"))
@@ -74,7 +74,7 @@ This is like `benchmark-run', but what is timed is a funcall of the
 byte code obtained by wrapping FORMS in a `lambda' and compiling the
 result.  The overhead of the `lambda's is accounted for."
   (declare (indent 1) (debug t))
-  (unless (natnump repetitions)
+  (unless (or (natnump repetitions) (and repetitions (symbolp repetitions)))
     (setq forms (cons repetitions forms)
           repetitions 1))
   (let ((i (make-symbol "i"))
@@ -84,7 +84,7 @@ result.  The overhead of the `lambda's is accounted for."
         (lambda-code (byte-compile `(lambda ()))))
     `(let ((,gc gc-elapsed)
            (,gcs gcs-done))
-       (list ,(if (> repetitions 1)
+       (list ,(if (or (symbolp repetitions) (> repetitions 1))
                   ;; Take account of the loop overhead.
                   `(- (benchmark-elapse (dotimes (,i ,repetitions)
                                           (funcall ,code)))
diff --git a/test/lisp/emacs-lisp/benchmark-tests.el b/test/lisp/emacs-lisp/benchmark-tests.el
index cba53aefc9f..26bd3ff08a8 100644
--- a/test/lisp/emacs-lisp/benchmark-tests.el
+++ b/test/lisp/emacs-lisp/benchmark-tests.el
@@ -28,18 +28,24 @@
     (should (consp (benchmark-run 1 (setq m (1+ 0)))))
     (should (stringp (benchmark nil (1+ 0))))
     (should (stringp (benchmark 1 (1+ 0))))
-    (should (consp (benchmark-run-compiled nil (1+ 0))))
+    (should (consp (benchmark-run-compiled (1+ 0))))
     (should (consp (benchmark-run-compiled 1 (1+ 0))))
     ;; First test is heavier, must need longer time.
-    (should (> (car (benchmark-run nil
+    (let ((count1 0)
+          (count2 0)
+          (repeat 2))
+      (ignore (benchmark-run (setq count1 (1+ count1))))
+      (ignore (benchmark-run repeat (setq count2 (1+ count2))))
+      (should (> count2 count1)))
+    (should (> (car (benchmark-run
                       (let ((n 100000)) (while (> n 1) (setq n (1- n))))))
-               (car (benchmark-run nil (setq m (1+ 0))))))
-    (should (> (car (benchmark-run nil
+               (car (benchmark-run (setq m (1+ 0))))))
+    (should (> (car (benchmark-run
                       (let ((n 100000)) (while (> n 1) (setq n (1- n))))))
-               (car (benchmark-run nil (setq m (1+ 0))))))
-    (should (> (car (benchmark-run-compiled nil
+               (car (benchmark-run (setq m (1+ 0))))))
+    (should (> (car (benchmark-run-compiled
                       (let ((n 100000)) (while (> n 1) (setq n (1- n))))))
-               (car (benchmark-run-compiled nil (1+ 0)))))
+               (car (benchmark-run-compiled (1+ 0)))))
     (setq str (benchmark nil '(let ((n 100000)) (while (> n 1) (setq n (1- n))))))
     (string-match "Elapsed time: \\([0-9.]+\\)" str)
     (setq t-long (string-to-number (match-string 1 str)))