Minor simplification in byte-opt.el

[Stefan Monnier]

Could someone look over the patch below to confirm it's safe?

Also, as a result of this, there is only one call to
`byte-optimize-form-code-walker` left, in `byte-optimize-form`, so maybe
the two functions could be merged, tho it's probably not worth the trouble.


        Stefan


    * lisp/emacs-lisp/byte-opt.el (byte-optimize-form-code-walker):
    After inlining, use `byte-optimize-form` so the top-level function's
    optimizer (if any) is also applied.
    Simplify the pure function handling by using `byte-optimize-constant-args`.
    (byte-optimize-all-constp): Remove.
    (byte-optimize-1+, byte-optimize-1-): Remove, since `pure` already
    takes care of it.


diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 6f801be545..afe07da0ec 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -227,7 +227,7 @@ byte-compile-log-lap
 
 ;;; byte-compile optimizers to support inlining
 
-(put 'inline 'byte-optimizer 'byte-optimize-inline-handler)
+(put 'inline 'byte-optimizer #'byte-optimize-inline-handler)
 
 (defun byte-optimize-inline-handler (form)
   "byte-optimize-handler for the `inline' special-form."
@@ -396,7 +396,7 @@ byte-optimize-form-code-walker
             (if (eq newform form)
                 ;; Some error occurred, avoid infinite recursion
                 form
-              (byte-optimize-form-code-walker newform for-effect))))
+              (byte-optimize-form newform for-effect))))
          ((eq (car-safe fn) 'closure) form)
          ((memq fn '(let let*))
           ;; recursively enter the optimizer for the bindings and body
@@ -554,23 +554,10 @@ byte-optimize-form-code-walker
           ;; Otherwise, no args can be considered to be for-effect,
           ;; even if the called function is for-effect, because we
           ;; don't know anything about that function.
-          (let ((args (mapcar #'byte-optimize-form (cdr form))))
-            (if (and (get fn 'pure)
-                     (byte-optimize-all-constp 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)
-  "Non-nil if all elements of LIST satisfy `macroexp-const-p'."
-  (let ((constant t))
-    (while (and list constant)
-      (unless (macroexp-const-p (car list))
-       (setq constant nil))
-      (setq list (cdr list)))
-    constant))
+          (let ((form (cons fn (mapcar #'byte-optimize-form (cdr form)))))
+            (if (get fn 'pure)
+                (byte-optimize-constant-args form)
+              form))))))
 
 (defun byte-optimize-form (form &optional for-effect)
   "The source-level pass of the optimizer."
@@ -747,22 +734,6 @@ byte-optimize-minus
        ((equal args (cdr form)) form)
        (t (cons '- args))))))
 
-(defun byte-optimize-1+ (form)
-  (let ((args (cdr form)))
-    (when (null (cdr args))
-      (let ((n (car args)))
-        (when (numberp n)
-          (setq form (1+ n))))))
-  form)
-
-(defun byte-optimize-1- (form)
-  (let ((args (cdr form)))
-    (when (null (cdr args))
-      (let ((n (car args)))
-        (when (numberp n)
-          (setq form (1- n))))))
-  form)
-
 (defun byte-optimize-multiply (form)
   (let* ((args (remq 1 (byte-opt--arith-reduce #'* 1 (cdr form)))))
     (cond
@@ -802,7 +773,7 @@ byte-optimize-binary-predicate
     (condition-case ()
         (list 'quote (eval form))
       (error form)))
-   (t ;; This can enable some lapcode optimizations.
+   (t ;; Moving the constant to the end can enable some lapcode optimizations.
     (list (car form) (nth 2 form) (nth 1 form)))))
 
 (defun byte-optimize-constant-args (form)
@@ -901,37 +872,34 @@ byte-optimize-concat
         form          ; No improvement.
       (cons 'concat (nreverse newargs)))))
 
-(put 'identity 'byte-optimizer 'byte-optimize-identity)
-(put 'memq 'byte-optimizer 'byte-optimize-memq)
-(put 'memql  'byte-optimizer 'byte-optimize-member)
-(put 'member 'byte-optimizer 'byte-optimize-member)
-(put 'assoc 'byte-optimizer 'byte-optimize-assoc)
-(put 'rassoc 'byte-optimizer 'byte-optimize-assoc)
-
-(put '+   'byte-optimizer 'byte-optimize-plus)
-(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 '=   'byte-optimizer 'byte-optimize-binary-predicate)
-(put 'eq  'byte-optimizer 'byte-optimize-binary-predicate)
-(put 'eql   'byte-optimizer 'byte-optimize-equal)
-(put 'equal 'byte-optimizer 'byte-optimize-equal)
-(put 'string= 'byte-optimizer 'byte-optimize-binary-predicate)
-(put 'string-equal 'byte-optimizer 'byte-optimize-binary-predicate)
-
-(put '1+  'byte-optimizer 'byte-optimize-1+)
-(put '1-  'byte-optimizer 'byte-optimize-1-)
-
-(put 'concat 'byte-optimizer 'byte-optimize-concat)
+(put 'identity 'byte-optimizer #'byte-optimize-identity)
+(put 'memq 'byte-optimizer #'byte-optimize-memq)
+(put 'memql  'byte-optimizer #'byte-optimize-member)
+(put 'member 'byte-optimizer #'byte-optimize-member)
+(put 'assoc 'byte-optimizer #'byte-optimize-assoc)
+(put 'rassoc 'byte-optimizer #'byte-optimize-assoc)
+
+(put '+   'byte-optimizer #'byte-optimize-plus)
+(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 '=   'byte-optimizer #'byte-optimize-binary-predicate)
+(put 'eq  'byte-optimizer #'byte-optimize-binary-predicate)
+(put 'eql   'byte-optimizer #'byte-optimize-equal)
+(put 'equal 'byte-optimizer #'byte-optimize-equal)
+(put 'string= 'byte-optimizer #'byte-optimize-binary-predicate)
+(put 'string-equal 'byte-optimizer #'byte-optimize-binary-predicate)
+
+(put 'concat 'byte-optimizer #'byte-optimize-concat)
 
 ;; I'm not convinced that this is necessary.  Doesn't the optimizer loop
 ;; take care of this? - Jamie
 ;; I think this may some times be necessary to reduce ie (quote 5) to 5,
 ;; so arithmetic optimizers recognize the numeric constant.  - Hallvard
-(put 'quote 'byte-optimizer 'byte-optimize-quote)
+(put 'quote 'byte-optimizer #'byte-optimize-quote)
 (defun byte-optimize-quote (form)
   (if (or (consp (nth 1 form))
          (and (symbolp (nth 1 form))
@@ -1049,16 +1017,16 @@ byte-optimize-while
   (if (nth 1 form)
       form))
 
-(put 'and   'byte-optimizer 'byte-optimize-and)
-(put 'or    'byte-optimizer 'byte-optimize-or)
-(put 'cond  'byte-optimizer 'byte-optimize-cond)
-(put 'if    'byte-optimizer 'byte-optimize-if)
-(put 'while 'byte-optimizer 'byte-optimize-while)
+(put 'and   'byte-optimizer #'byte-optimize-and)
+(put 'or    'byte-optimizer #'byte-optimize-or)
+(put 'cond  'byte-optimizer #'byte-optimize-cond)
+(put 'if    'byte-optimizer #'byte-optimize-if)
+(put 'while 'byte-optimizer #'byte-optimize-while)
 
 ;; byte-compile-negation-optimizer lives in bytecomp.el
-(put '/= 'byte-optimizer 'byte-compile-negation-optimizer)
-(put 'atom 'byte-optimizer 'byte-compile-negation-optimizer)
-(put 'nlistp 'byte-optimizer 'byte-compile-negation-optimizer)
+(put '/= 'byte-optimizer #'byte-compile-negation-optimizer)
+(put 'atom 'byte-optimizer #'byte-compile-negation-optimizer)
+(put 'nlistp 'byte-optimizer #'byte-compile-negation-optimizer)
 
 
 (defun byte-optimize-funcall (form)
@@ -1086,12 +1054,12 @@ byte-optimize-apply
              nil))
        form)))
 
-(put 'funcall 'byte-optimizer 'byte-optimize-funcall)
-(put 'apply   'byte-optimizer 'byte-optimize-apply)
+(put 'funcall 'byte-optimizer #'byte-optimize-funcall)
+(put 'apply   'byte-optimizer #'byte-optimize-apply)
 
 
-(put 'let 'byte-optimizer 'byte-optimize-letX)
-(put 'let* 'byte-optimizer 'byte-optimize-letX)
+(put 'let 'byte-optimizer #'byte-optimize-letX)
+(put 'let* 'byte-optimizer #'byte-optimize-letX)
 (defun byte-optimize-letX (form)
   (cond ((null (nth 1 form))
         ;; No bindings
@@ -1107,7 +1075,7 @@ byte-optimize-letX
           (list 'let* (reverse (cdr binds)) (nth 1 (car binds)) nil)))))
 
 
-(put 'nth 'byte-optimizer 'byte-optimize-nth)
+(put 'nth 'byte-optimizer #'byte-optimize-nth)
 (defun byte-optimize-nth (form)
   (if (= (safe-length form) 3)
       (if (memq (nth 1 form) '(0 1))
@@ -1117,7 +1085,7 @@ byte-optimize-nth
        form)
     form))
 
-(put 'nthcdr 'byte-optimizer 'byte-optimize-nthcdr)
+(put 'nthcdr 'byte-optimizer #'byte-optimize-nthcdr)
 (defun byte-optimize-nthcdr (form)
   (if (= (safe-length form) 3)
       (if (memq (nth 1 form) '(0 1 2))
@@ -1133,7 +1101,7 @@ byte-optimize-nthcdr
 ;; optimize string-as-unibyte, string-as-multibyte, string-make-unibyte,
 ;; string-make-multibyte for constant args.
 
-(put 'set 'byte-optimizer 'byte-optimize-set)
+(put 'set 'byte-optimizer #'byte-optimize-set)
 (defun byte-optimize-set (form)
   (let ((var (car-safe (cdr-safe form))))
     (cond