* lisp/subr.el (zerop): Move from C. Add compiler-macro.

* lisp/emacs-lisp/byte-opt.el (byte-optimize-zerop): Remove.
* src/data.c (Fzerop): Move to Elisp.
(syms_of_data): Don't defsubr it.
* src/keyboard.c (echo_keystrokes_p): New function.
(read_char, record_menu_key, read_key_sequence): Use it.

Fixes: debbugs:17475

3 files changed, 12 insertions, 11 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 8845b77b3b..22e88a453c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,10 +1,12 @@
 2014-05-28  Stefan Monnier  <[email protected]>
 
+	* subr.el (zerop): Move from C.  Add compiler-macro (bug#17475).
+	* emacs-lisp/byte-opt.el (byte-optimize-zerop): Remove.
+
 	* subr.el (internal--funcall-interactively): New.
 	(internal--call-interactively): Remove.
 	(called-interactively-p): Detect funcall-interactively instead of
 	call-interactively.
-
 	* simple.el (repeat-complex-command): Use funcall-interactively.
 	(repeat-complex-command--called-interactively-skip): Remove.
 
diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index b1e06410da..90d1dd913e 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -942,15 +942,6 @@
       form
     (nth 1 form)))
 
-(defun byte-optimize-zerop (form)
-  (cond ((numberp (nth 1 form))
-	 (eval form))
-	(byte-compile-delete-errors
-	 (list '= (nth 1 form) 0))
-	(form)))
-
-(put 'zerop 'byte-optimizer 'byte-optimize-zerop)
-
 (defun byte-optimize-and (form)
   ;; Simplify if less than 2 args.
   ;; if there is a literal nil in the args to `and', throw it and following
diff --git a/lisp/subr.el b/lisp/subr.el
index a72a026f19..8767511f65 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -334,6 +334,13 @@ Any list whose car is `frame-configuration' is assumed to be a frame
 configuration."
   (and (consp object)
        (eq (car object) 'frame-configuration)))
+
+(defun zerop (number)
+  "Return t if NUMBER is zero."
+  ;; Used to be in C, but it's pointless since (= 0 n) is faster anyway because
+  ;; = has a byte-code.
+  (declare (compiler-macro (lambda (_) `(= 0 ,number))))
+  (= 0 number))
 
 ;;;; List functions.
 
@@ -3845,7 +3852,8 @@ This function is called directly from the C code."
 	    (byte-compile-log-warning msg))
 	(run-with-timer 0 nil
 			(lambda (msg)
-			  (message "%s" msg)) msg))))
+			  (message "%s" msg))
+                        msg))))
 
   ;; Finally, run any other hook.
   (run-hook-with-args 'after-load-functions abs-file))