From: Vibhav Pant <vibhavp@gmail.com>
Date: Sun, 15 Jan 2017 16:08:31 +0000 (+0530)
Subject: * lisp/emacs-lisp/byte-opt.el: Optimize how tags are checked for use.
X-Git-Tag: emacs-26.0.90~887
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=309b46420e83826ed1e0b947f98a47e8525e3c36;p=emacs.git

* lisp/emacs-lisp/byte-opt.el: Optimize how tags are checked for use.

* byte-opt.el: (byte-optimize-lapcode): Return nil instantly on
  finding the tag in a jump table.
---

diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 9412ce3b26d..c774d26c04b 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -1730,10 +1730,9 @@ If FOR-EFFECT is non-nil, the return value is assumed to be of no importance."
 	      ;;
 	      ((and (eq 'TAG (car lap0))
 		    (not (rassq lap0 lap))
-                    (= (length (cl-loop for table in byte-compile-jump-tables
-                                        when (member lap0 (hash-table-values table))
-                                        collect t))
-                       0))
+                    (cl-loop for table in byte-compile-jump-tables
+                             when (member lap0 (hash-table-values table))
+                             return nil finally return t))
 	       (and (memq byte-optimize-log '(t byte))
 		    (byte-compile-log "  unused tag %d removed" (nth 1 lap0)))
 	       (setq lap (delq lap0 lap)