From: Mattias Engdegård Date: Thu, 4 May 2023 15:37:17 +0000 (+0200) Subject: Constant-propagate cons and vector literals X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=044392c5c563a0bb2c24b65e5222b8f9b3cbe0d8;p=emacs.git Constant-propagate cons and vector literals * lisp/emacs-lisp/byte-opt.el (byte-optimize--substitutable-p): Allow quoted lists and conses, and vector literals, to be substituted from lexical variables. This can eliminate variable bindings and create new constant folding opportunities. --- diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el index d046c4d401c..8fe5066c49e 100644 --- a/lisp/emacs-lisp/byte-opt.el +++ b/lisp/emacs-lisp/byte-opt.el @@ -221,21 +221,17 @@ for speeding up processing.") (defun byte-optimize--substitutable-p (expr) "Whether EXPR is a constant that can be propagated." - ;; Only consider numbers, symbols and strings to be values for substitution - ;; purposes. Numbers and symbols are immutable, and mutating string - ;; literals (or results from constant-evaluated string-returning functions) - ;; can be considered undefined. - ;; (What about other quoted values, like conses?) (or (booleanp expr) (numberp expr) - (stringp expr) - (and (consp expr) - (or (and (memq (car expr) '(quote function)) - (symbolp (cadr expr))) - ;; (internal-get-closed-var N) can be considered constant for - ;; const-prop purposes. - (and (eq (car expr) 'internal-get-closed-var) - (integerp (cadr expr))))) + (arrayp expr) + (let ((head (car-safe expr))) + (cond ((eq head 'quote) t) + ;; Don't substitute #'(lambda ...) since that would enable + ;; uncontrolled inlining. + ((eq head 'function) (symbolp (cadr expr))) + ;; (internal-get-closed-var N) can be considered constant for + ;; const-prop purposes. + ((eq head 'internal-get-closed-var) (integerp (cadr expr))))) (keywordp expr))) (defmacro byte-optimize--pcase (exp &rest cases)