diff options
Diffstat (limited to 'lisp/emacs-lisp')
| -rw-r--r-- | lisp/emacs-lisp/byte-opt.el | 49 |
1 files changed, 42 insertions, 7 deletions
diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el index bf9e6a728a3..971e4ddbcc9 100644 --- a/lisp/emacs-lisp/byte-opt.el +++ b/lisp/emacs-lisp/byte-opt.el @@ -557,7 +557,10 @@ (let ((args (mapcar #'byte-optimize-form (cdr form)))) (if (and (get fn 'pure) (byte-optimize-all-constp args)) - (list 'quote (apply fn (mapcar #'eval args))) + (let ((arg-values (mapcar #'eval args))) + (condition-case nil + (list 'quote (apply fn arg-values)) + (error (cons fn args)))) (cons fn args))))))) (defun byte-optimize-all-constp (list) @@ -1274,9 +1277,9 @@ ;; Pure functions are side-effect free functions whose values depend ;; only on their arguments, not on the platform. For these functions, ;; calls with constant arguments can be evaluated at compile time. -;; This may shift runtime errors to compile time. For example, logand -;; is pure since its results are machine-independent, whereas ash is -;; not pure because (ash 1 29)'s value depends on machine word size. +;; For example, ash is pure since its results are machine-independent, +;; whereas lsh is not pure because (lsh -1 -1)'s value depends on the +;; fixnum range. ;; ;; When deciding whether a function is pure, do not worry about ;; mutable strings or markers, as they are so unlikely in real code @@ -1286,9 +1289,41 @@ ;; values if a marker is moved. (let ((pure-fns - '(% concat logand logcount logior lognot logxor - regexp-opt regexp-quote - string-to-char string-to-syntax symbol-name))) + '(concat regexp-opt regexp-quote + string-to-char string-to-syntax symbol-name + eq eql + = /= < <= => > min max + + - * / % mod abs ash 1+ 1- sqrt + logand logior lognot logxor logcount + copysign isnan ldexp float logb + floor ceiling round truncate + ffloor fceiling fround ftruncate + string= string-equal string< string-lessp + consp atom listp nlistp propert-list-p + sequencep arrayp vectorp stringp bool-vector-p hash-table-p + null not + numberp integerp floatp natnump characterp + integer-or-marker-p number-or-marker-p char-or-string-p + symbolp keywordp + type-of + identity ignore + + ;; The following functions are pure up to mutation of their + ;; arguments. This is pure enough for the purposes of + ;; constant folding, but not necessarily for all kinds of + ;; code motion. + car cdr car-safe cdr-safe nth nthcdr last + equal + length safe-length + memq memql member + ;; `assoc' and `assoc-default' are excluded since they are + ;; impure if the test function is (consider `string-match'). + assq rassq rassoc + plist-get lax-plist-get plist-member + aref elt + bool-vector-subsetp + bool-vector-count-population bool-vector-count-consecutive + ))) (while pure-fns (put (car pure-fns) 'pure t) (setq pure-fns (cdr pure-fns))) |