comparison lisp/byte-optimize.el @ 5366:f00192e1cd49

Examining the result of #'length: `eql', not `=', it's better style & cheaper 2011-03-08 Aidan Kehoe <kehoea@parhasard.net> * buff-menu.el (list-buffers-noselect): * byte-optimize.el (byte-optimize-identity): * byte-optimize.el (byte-optimize-if): * byte-optimize.el (byte-optimize-nth): * byte-optimize.el (byte-optimize-nthcdr): * bytecomp.el (byte-compile-warn-wrong-args): * bytecomp.el (byte-compile-two-args-19->20): * bytecomp.el (byte-compile-list): * bytecomp.el (byte-compile-beginning-of-line): * bytecomp.el (byte-compile-set): * bytecomp.el (byte-compile-set-default): * bytecomp.el (byte-compile-values): * bytecomp.el (byte-compile-values-list): * bytecomp.el (byte-compile-integerp): * bytecomp.el (byte-compile-multiple-value-list-internal): * bytecomp.el (byte-compile-throw): * cl-macs.el (cl-do-arglist): * cl-macs.el (cl-parse-loop-clause): * cl-macs.el (multiple-value-bind): * cl-macs.el (multiple-value-setq): * cl-macs.el (get-setf-method): * cmdloop.el (command-error): * cmdloop.el (y-or-n-p-minibuf): * cmdloop.el (yes-or-no-p-minibuf): * coding.el (unencodable-char-position): * cus-edit.el (custom-face-prompt): * cus-edit.el (custom-buffer-create-internal): * cus-edit.el (widget-face-action): * cus-edit.el (custom-group-value-create): * descr-text.el (describe-char-unicode-data): * dialog-gtk.el (popup-builtin-question-dialog): * dragdrop.el (experimental-dragdrop-drop-log-function): * dragdrop.el (experimental-dragdrop-drop-mime-default): * easymenu.el (easy-menu-add): * easymenu.el (easy-menu-remove): * faces.el (read-face-name): * faces.el (set-face-stipple): * files.el (file-name-non-special): * font.el (font-combine-fonts): * font.el (font-set-face-font): * font.el (font-parse-rgb-components): * font.el (font-rgb-color-p): * font.el (font-color-rgb-components): * gnuserv.el (gnuserv-edit-files): * help.el (key-or-menu-binding): * help.el (function-documentation-1): * help.el (function-documentation): * info.el (info): * isearch-mode.el (isearch-exit): * isearch-mode.el (isearch-edit-string): * isearch-mode.el (isearch-*-char): * isearch-mode.el (isearch-complete1): * ldap.el (ldap-encode-country-string): * ldap.el (ldap-decode-string): * minibuf.el (read-file-name-internal-1): * minibuf.el (read-non-nil-coding-system): * minibuf.el (get-user-response): * mouse.el (drag-window-divider): * mule/ccl.el: * mule/ccl.el (ccl-compile-if): * mule/ccl.el (ccl-compile-break): * mule/ccl.el (ccl-compile-repeat): * mule/ccl.el (ccl-compile-write-repeat): * mule/ccl.el (ccl-compile-call): * mule/ccl.el (ccl-compile-end): * mule/ccl.el (ccl-compile-read-multibyte-character): * mule/ccl.el (ccl-compile-write-multibyte-character): * mule/ccl.el (ccl-compile-translate-character): * mule/ccl.el (ccl-compile-mule-to-unicode): * mule/ccl.el (ccl-compile-unicode-to-mule): * mule/ccl.el (ccl-compile-lookup-integer): * mule/ccl.el (ccl-compile-lookup-character): * mule/ccl.el (ccl-compile-map-multiple): * mule/ccl.el (ccl-compile-map-single): * mule/devan-util.el (devanagari-compose-to-one-glyph): * mule/devan-util.el (devanagari-composition-component): * mule/mule-cmds.el (finish-set-language-environment): * mule/viet-util.el: * mule/viet-util.el (viet-encode-viscii-char): * multicast.el (open-multicast-group): * newcomment.el (comment-quote-nested): * newcomment.el (comment-region): * newcomment.el (comment-dwim): * regexp-opt.el (regexp-opt-group): * replace.el (map-query-replace-regexp): * specifier.el (derive-device-type-from-tag-set): * subr.el (skip-chars-quote): * test-harness.el (test-harness-from-buffer): * test-harness.el (batch-test-emacs): * wid-edit.el (widget-choice-action): * wid-edit.el (widget-symbol-prompt-internal): * wid-edit.el (widget-color-action): * window-xemacs.el (push-window-configuration): * window-xemacs.el (pop-window-configuration): * window.el (quit-window): * x-compose.el (electric-diacritic): It's better style, and cheaper (often one assembler instruction vs. a C funcall in the byte code), to use `eql' instead of `=' when it's clear what numerical type a given result will be. Change much of our code to do this, with the help of a byte-compiler change (not comitted) that looked for calls to #'length (which always returns an integer) in its args.
author Aidan Kehoe <kehoea@parhasard.net>
date Tue, 08 Mar 2011 23:41:52 +0000
parents 07d24b1f27a7
children ac37a5f7e5be
comparison
equal deleted inserted replaced
5365:dbae25a8949d 5366:f00192e1cd49
821 (defun byte-optimize-identity (form) 821 (defun byte-optimize-identity (form)
822 (if (and (cdr form) (null (cdr (cdr form)))) 822 (if (and (cdr form) (null (cdr (cdr form))))
823 (nth 1 form) 823 (nth 1 form)
824 (byte-compile-warn "identity called with %d arg%s, but requires 1" 824 (byte-compile-warn "identity called with %d arg%s, but requires 1"
825 (length (cdr form)) 825 (length (cdr form))
826 (if (= 1 (length (cdr form))) "" "s")) 826 (if (eql 1 (length (cdr form))) "" "s"))
827 form)) 827 form))
828 828
829 (defun byte-optimize-car (form) 829 (defun byte-optimize-car (form)
830 (let ((arg (cadr form))) 830 (let ((arg (cadr form)))
831 (cond 831 (cond
1019 ((or (nth 3 form) (nthcdr 4 form)) 1019 ((or (nth 3 form) (nthcdr 4 form))
1020 (list 'if 1020 (list 'if
1021 ;; Don't make a double negative; 1021 ;; Don't make a double negative;
1022 ;; instead, take away the one that is there. 1022 ;; instead, take away the one that is there.
1023 (if (and (consp clause) (memq (car clause) '(not null)) 1023 (if (and (consp clause) (memq (car clause) '(not null))
1024 (= (length clause) 2)) ; (not xxxx) or (not (xxxx)) 1024 (eql (length clause) 2)) ; (not xxxx) or (not (xxxx))
1025 (nth 1 clause) 1025 (nth 1 clause)
1026 (list 'not clause)) 1026 (list 'not clause))
1027 (if (nthcdr 4 form) 1027 (if (nthcdr 4 form)
1028 (cons 'progn (nthcdr 3 form)) 1028 (cons 'progn (nthcdr 3 form))
1029 (nth 3 form)))) 1029 (nth 3 form))))
1161 (list 'let* (reverse (cdr binds)) (nth 1 (car binds)) nil))))) 1161 (list 'let* (reverse (cdr binds)) (nth 1 (car binds)) nil)))))
1162 1162
1163 1163
1164 (put 'nth 'byte-optimizer 'byte-optimize-nth) 1164 (put 'nth 'byte-optimizer 'byte-optimize-nth)
1165 (defun byte-optimize-nth (form) 1165 (defun byte-optimize-nth (form)
1166 (if (and (= (safe-length form) 3) (memq (nth 1 form) '(0 1))) 1166 (if (and (eql (safe-length form) 3) (memq (nth 1 form) '(0 1)))
1167 (list 'car (if (zerop (nth 1 form)) 1167 (list 'car (if (zerop (nth 1 form))
1168 (nth 2 form) 1168 (nth 2 form)
1169 (list 'cdr (nth 2 form)))) 1169 (list 'cdr (nth 2 form))))
1170 (byte-optimize-predicate form))) 1170 (byte-optimize-predicate form)))
1171 1171
1172 (put 'nthcdr 'byte-optimizer 'byte-optimize-nthcdr) 1172 (put 'nthcdr 'byte-optimizer 'byte-optimize-nthcdr)
1173 (defun byte-optimize-nthcdr (form) 1173 (defun byte-optimize-nthcdr (form)
1174 (if (and (= (safe-length form) 3) (not (memq (nth 1 form) '(0 1 2)))) 1174 (if (and (eql (safe-length form) 3) (not (memq (nth 1 form) '(0 1 2))))
1175 (byte-optimize-predicate form) 1175 (byte-optimize-predicate form)
1176 (let ((count (nth 1 form))) 1176 (let ((count (nth 1 form)))
1177 (setq form (nth 2 form)) 1177 (setq form (nth 2 form))
1178 (while (>= (setq count (1- count)) 0) 1178 (while (>= (setq count (1- count)) 0)
1179 (setq form (list 'cdr form))) 1179 (setq form (list 'cdr form)))