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| author | Mattias Engdegård <mattiase@acm.org> | 2020-08-03 16:29:06 +0200 |
|---|---|---|
| committer | Mattias Engdegård <mattiase@acm.org> | 2020-08-07 10:00:45 +0200 |
| commit | 0facaeec1a37481536b6cef13c88d9728c2ec29b (patch) | |
| tree | cc1c6126c46d1bc921065de555d4513de736c643 /lisp/emacs-lisp/byte-opt.el | |
| parent | 204273c3b9f0a77459661790aa929f86067a9ab1 (diff) | |
| download | emacs-0facaeec1a37481536b6cef13c88d9728c2ec29b.tar.gz emacs-0facaeec1a37481536b6cef13c88d9728c2ec29b.tar.bz2 emacs-0facaeec1a37481536b6cef13c88d9728c2ec29b.zip | |
Clean up and improve compilation of arithmetic (bug#42597)
* lisp/emacs-lisp/byte-opt.el (byte-optimize-associative-math)
(byte-optimize-min-max): Transform 3-arg min/max call into two 2-arg
calls, which is faster.
* lisp/emacs-lisp/bytecomp.el (byte-compile-associative): Rename to...
(byte-compile-variadic-numeric): ...this function and simplify,
fixing incorrect comments. The 3-arg strength reduction is now
always done in the optimisers and is no longer needed here.
(byte-compile-min-max): New function.
(byte-compile-minus): Simplify, remove incorrect comment, and use
byte-compile-variadic-numeric.
(byte-compile-quo): Simplify and fix comment.
Diffstat (limited to 'lisp/emacs-lisp/byte-opt.el')
| -rw-r--r-- | lisp/emacs-lisp/byte-opt.el | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el index 0d9c449b3b4..4987596bf95 100644 --- a/lisp/emacs-lisp/byte-opt.el +++ b/lisp/emacs-lisp/byte-opt.el @@ -648,14 +648,23 @@ (setq args (cons (car rest) args))) (setq rest (cdr rest))) (if (cdr constants) - (if args - (list (car form) - (apply (car form) constants) - (if (cdr args) - (cons (car form) (nreverse args)) - (car args))) - (apply (car form) constants)) - form))) + (let ((const (apply (car form) (nreverse constants)))) + (if args + (append (list (car form) const) + (nreverse args)) + const)) + form))) + +(defun byte-optimize-min-max (form) + "Optimize `min' and `max'." + (let ((opt (byte-optimize-associative-math form))) + (if (and (consp opt) (memq (car opt) '(min max)) + (= (length opt) 4)) + ;; (OP x y z) -> (OP (OP x y) z), in order to use binary byte ops. + (list (car opt) + (list (car opt) (nth 1 opt) (nth 2 opt)) + (nth 3 opt)) + opt))) ;; Use OP to reduce any leading prefix of constant numbers in the list ;; (cons ACCUM ARGS) down to a single number, and return the @@ -878,8 +887,8 @@ (put '* 'byte-optimizer #'byte-optimize-multiply) (put '- 'byte-optimizer #'byte-optimize-minus) (put '/ 'byte-optimizer #'byte-optimize-divide) -(put 'max 'byte-optimizer #'byte-optimize-associative-math) -(put 'min 'byte-optimizer #'byte-optimize-associative-math) +(put 'max 'byte-optimizer #'byte-optimize-min-max) +(put 'min 'byte-optimizer #'byte-optimize-min-max) (put '= 'byte-optimizer #'byte-optimize-binary-predicate) (put 'eq 'byte-optimizer #'byte-optimize-binary-predicate) |