From 9d35afed49896928433bb28a781b6060bc1601b1 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Mattias=20Engdeg=C3=A5rd?= Date: Tue, 9 Aug 2022 10:57:46 +0200 Subject: [PATCH] Extend LAP optimisations to more operations Extend the set of eligible opcodes for certain peephole transformations, which then provide further optimisation opportunities. * lisp/emacs-lisp/byte-opt.el (byte-optimize-lapcode): Optimise empty save-current-buffer in the same way as we already do for save-excursion and save-restriction. This is safe because (save-current-buffer) is a no-op. (byte-compile-side-effect-and-error-free-ops): Add list3, list4 and listN. These were all apparent oversights as list1 and list2 were already included. (byte-after-unbind-ops): Add stack-ref, stack-set, discard, list3, list4 and listN. Stack manipulation is safe because unbind cannot read or modify stack entries. --- lisp/emacs-lisp/byte-opt.el | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el index 7a4bbf2e8af..a7edecfac73 100644 --- a/lisp/emacs-lisp/byte-opt.el +++ b/lisp/emacs-lisp/byte-opt.el @@ -1747,10 +1747,10 @@ See Info node `(elisp) Integer Basics'." byte-goto-if-not-nil-else-pop)) (defconst byte-after-unbind-ops - '(byte-constant byte-dup + '(byte-constant byte-dup byte-stack-ref byte-stack-set byte-discard byte-symbolp byte-consp byte-stringp byte-listp byte-numberp byte-integerp byte-eq byte-not - byte-cons byte-list1 byte-list2 ; byte-list3 byte-list4 + byte-cons byte-list1 byte-list2 byte-list3 byte-list4 byte-listN byte-interactive-p) ;; How about other side-effect-free-ops? Is it safe to move an ;; error invocation (such as from nth) out of an unwind-protect? @@ -1762,7 +1762,8 @@ See Info node `(elisp) Integer Basics'." (defconst byte-compile-side-effect-and-error-free-ops '(byte-constant byte-dup byte-symbolp byte-consp byte-stringp byte-listp byte-integerp byte-numberp byte-eq byte-equal byte-not byte-car-safe - byte-cdr-safe byte-cons byte-list1 byte-list2 byte-point byte-point-max + byte-cdr-safe byte-cons byte-list1 byte-list2 byte-list3 byte-list4 + byte-listN byte-point byte-point-max byte-point-min byte-following-char byte-preceding-char byte-current-column byte-eolp byte-eobp byte-bolp byte-bobp byte-current-buffer byte-stack-ref)) @@ -2113,13 +2114,15 @@ If FOR-EFFECT is non-nil, the return value is assumed to be of no importance." (setcar (cdr rest) lap0) (setq keep-going t)) ;; - ;; varbind-X unbind-N --> discard unbind-(N-1) - ;; save-excursion unbind-N --> unbind-(N-1) - ;; save-restriction unbind-N --> unbind-(N-1) + ;; varbind-X unbind-N --> discard unbind-(N-1) + ;; save-excursion unbind-N --> unbind-(N-1) + ;; save-restriction unbind-N --> unbind-(N-1) + ;; save-current-buffer unbind-N --> unbind-(N-1) ;; ((and (eq 'byte-unbind (car lap1)) (memq (car lap0) '(byte-varbind byte-save-excursion - byte-save-restriction)) + byte-save-restriction + byte-save-current-buffer)) (< 0 (cdr lap1))) (if (zerop (setcdr lap1 (1- (cdr lap1)))) (delq lap1 rest)) -- 2.39.5