master 3f990c3 2/2: Simplify byte-code optimisation of pure functions

[Mattias Engdegård]

branch: master
commit 3f990c3cccf85e64399bf98ea3e61cb618e8455c
Author: Mattias Engdegård <mattiase@acm.org>
Commit: Mattias Engdegård <mattiase@acm.org>

    Simplify byte-code optimisation of pure functions
    
    Most pure functions need no explicit optimisation; we can do away with
    almost all uses of byte-optimize-predicate (now renamed to
    byte-optimize-constant-args, since it is not just for predicates).
    Also remove some superfluous arity warnings.
    
    * lisp/emacs-lisp/byte-opt.el (byte-optimize-identity, byte-optimize-memq)
    (byte-optimize-nth, byte-optimize-nthcdr):
    Remove arity warnings and simplify.
    * lisp/emacs-lisp/byte-opt.el (<, >, <=, >=, not, null, consp, listp)
    (symbolp, stringp, string<, string-lessp, proper-list-p, logand)
    (logior, logxor, lognot, car, cdr, car-safe, cdr-safe):
    Remove superfluous byte-optimizer property.
    (byte-optimize-predicate): Rename to byte-optimize-constant-args.
    All uses changed.
---
 lisp/emacs-lisp/byte-opt.el | 57 +++++++++++----------------------------------
 1 file changed, 14 insertions(+), 43 deletions(-)

diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 971e4dd..646994a 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -795,7 +795,7 @@
    (t ;; This can enable some lapcode optimizations.
     (list (car form) (nth 2 form) (nth 1 form)))))
 
-(defun byte-optimize-predicate (form)
+(defun byte-optimize-constant-args (form)
   (let ((ok t)
        (rest (cdr form)))
     (while (and rest ok)
@@ -810,9 +810,6 @@
 (defun byte-optimize-identity (form)
   (if (and (cdr form) (null (cdr (cdr form))))
       (nth 1 form)
-    (byte-compile-warn "identity called with %d arg%s, but requires 1"
-                      (length (cdr form))
-                      (if (= 1 (length (cdr form))) "" "s"))
     form))
 
 (defun byte-optimize--constant-symbol-p (expr)
@@ -847,19 +844,16 @@
 
 (defun byte-optimize-memq (form)
   ;; (memq foo '(bar)) => (and (eq foo 'bar) '(bar))
-  (if (/= (length (cdr form)) 2)
-      (byte-compile-warn "memq called with %d arg%s, but requires 2"
-                        (length (cdr form))
-                        (if (= 1 (length (cdr form))) "" "s"))
-    (let ((list (nth 2 form)))
-      (when (and (eq (car-safe list) 'quote)
+  (if (= (length (cdr form)) 2)
+      (let ((list (nth 2 form)))
+        (if (and (eq (car-safe list) 'quote)
                  (listp (setq list (cadr list)))
                  (= (length list) 1))
-        (setq form (byte-optimize-and
-                    `(and ,(byte-optimize-predicate
-                            `(eq ,(nth 1 form) ',(nth 0 list)))
-                          ',list)))))
-    (byte-optimize-predicate form)))
+            `(and (eq ,(nth 1 form) ',(nth 0 list))
+                  ',list)
+          form))
+    ;; Arity errors reported elsewhere.
+    form))
 
 (defun byte-optimize-concat (form)
   "Merge adjacent constant arguments to `concat'."
@@ -907,31 +901,8 @@
 (put 'string= 'byte-optimizer 'byte-optimize-binary-predicate)
 (put 'string-equal 'byte-optimizer 'byte-optimize-binary-predicate)
 
-(put '<   'byte-optimizer 'byte-optimize-predicate)
-(put '>   'byte-optimizer 'byte-optimize-predicate)
-(put '<=  'byte-optimizer 'byte-optimize-predicate)
-(put '>=  'byte-optimizer 'byte-optimize-predicate)
 (put '1+  'byte-optimizer 'byte-optimize-1+)
 (put '1-  'byte-optimizer 'byte-optimize-1-)
-(put 'not 'byte-optimizer 'byte-optimize-predicate)
-(put 'null  'byte-optimizer 'byte-optimize-predicate)
-(put 'consp 'byte-optimizer 'byte-optimize-predicate)
-(put 'listp 'byte-optimizer 'byte-optimize-predicate)
-(put 'symbolp 'byte-optimizer 'byte-optimize-predicate)
-(put 'stringp 'byte-optimizer 'byte-optimize-predicate)
-(put 'string< 'byte-optimizer 'byte-optimize-predicate)
-(put 'string-lessp  'byte-optimizer 'byte-optimize-predicate)
-(put 'proper-list-p 'byte-optimizer 'byte-optimize-predicate)
-
-(put 'logand 'byte-optimizer 'byte-optimize-predicate)
-(put 'logior 'byte-optimizer 'byte-optimize-predicate)
-(put 'logxor 'byte-optimizer 'byte-optimize-predicate)
-(put 'lognot 'byte-optimizer 'byte-optimize-predicate)
-
-(put 'car 'byte-optimizer 'byte-optimize-predicate)
-(put 'cdr 'byte-optimizer 'byte-optimize-predicate)
-(put 'car-safe 'byte-optimizer 'byte-optimize-predicate)
-(put 'cdr-safe 'byte-optimizer 'byte-optimize-predicate)
 
 (put 'concat 'byte-optimizer 'byte-optimize-concat)
 
@@ -962,7 +933,7 @@
               nil))
        ((null (cdr (cdr form)))
         (nth 1 form))
-       ((byte-optimize-predicate form))))
+       ((byte-optimize-constant-args form))))
 
 (defun byte-optimize-or (form)
   ;; Throw away nil's, and simplify if less than 2 args.
@@ -975,7 +946,7 @@
          (setq form (copy-sequence form)
                rest (setcdr (memq (car rest) form) nil))))
     (if (cdr (cdr form))
-       (byte-optimize-predicate form)
+       (byte-optimize-constant-args form)
       (nth 1 form))))
 
 (defun byte-optimize-cond (form)
@@ -1122,7 +1093,7 @@
          (list 'car (if (zerop (nth 1 form))
                         (nth 2 form)
                       (list 'cdr (nth 2 form))))
-       (byte-optimize-predicate form))
+       form)
     form))
 
 (put 'nthcdr 'byte-optimizer 'byte-optimize-nthcdr)
@@ -1134,7 +1105,7 @@
            (while (>= (setq count (1- count)) 0)
              (setq form (list 'cdr form)))
            form)
-       (byte-optimize-predicate form))
+       form)
     form))
 
 ;; Fixme: delete-char -> delete-region (byte-coded)
@@ -2208,7 +2179,7 @@ If FOR-EFFECT is non-nil, the return value is assumed to 
be of no importance."
               (or noninteractive (message "compiling %s...done" x)))
             '(byte-optimize-form
               byte-optimize-body
-              byte-optimize-predicate
+              byte-optimize-constant-args
               byte-optimize-binary-predicate
               ;; Inserted some more than necessary, to speed it up.
               byte-optimize-form-code-walker