my old bytecode optimization patch

[Paul Pogonyshev <pogonyshev@gmx.net>]

Hi,

I'm not sure what became with this patch, most likely it just got
forgotten.

The patch:
http://lists.gnu.org/archive/html/emacs-devel/2004-09/msg00715.html

RMS blessing:
http://lists.gnu.org/archive/html/emacs-devel/2004-09/msg00780.html

For convenience, I also append the patch text below.

Paul


*** byte-opt.el	23 Jun 2007 12:18:07 +0300	1.94
--- byte-opt.el	01 Jul 2007 18:11:16 +0300	
***************
*** 1444,1449 ****
--- 1444,1475 ----
       byte-member byte-assq byte-quo byte-rem)
     byte-compile-side-effect-and-error-free-ops))
  
+ (defconst byte-compile-side-effect-free-dynamically-safe-ops
+   '(;; Same as `byte-compile-side-effect-free-ops' but without
+     ;; `byte-varref', `byte-symbol-value' and certain editing
+     ;; primitives.
+     byte-constant byte-dup byte-symbolp byte-consp byte-stringp byte-listp
+     byte-integerp byte-numberp byte-eq byte-equal byte-not byte-car-safe
+     byte-cdr-safe byte-cons byte-list1 byte-list2 byte-point byte-point-max
+     byte-point-min byte-following-char byte-preceding-char
+     byte-eolp byte-eobp byte-bolp byte-bobp
+     ;;
+     ;; Bytecodes from `byte-compile-side-effect-and-error-free-ops'.
+     ;; We are not going to remove them, so it is fine.
+     byte-nth byte-memq byte-car byte-cdr byte-length byte-aref
+     byte-get byte-concat2 byte-concat3 byte-sub1 byte-add1
+     byte-eqlsign byte-gtr byte-lss byte-leq byte-geq byte-diff byte-negate
+     byte-plus byte-max byte-min byte-mult byte-char-after
+     byte-string= byte-string< byte-nthcdr byte-elt
+     byte-member byte-assq byte-quo byte-rem))
+ 
+ (put 'debug-on-error 'binding-is-magic t)
+ (put 'debug-on-abort 'binding-is-magic t)
+ (put 'inhibit-quit 'binding-is-magic t)
+ (put 'quit-flag 'binding-is-magic t)
+ (put 'gc-cons-threshold 'binding-is-magic t)
+ (put 'track-mouse 'binding-is-magic t)
+ 
  ;; This crock is because of the way DEFVAR_BOOL variables work.
  ;; Consider the code
  ;;
***************
*** 1848,1853 ****
--- 1874,1928 ----
  		      (setq lap (delq lap0 lap))))
  	       (setq keep-going t))
  	      ;;
+ 	      ;; varbind-X [car/cdr/ ...] unbind-1 --> discard [car/cdr/ ...]
+ 	      ;; varbind-X [car/cdr/ ...] unbind-N
+ 	      ;;   --> discard [car/cdr/ ...] unbind-(N-1)
+ 	      ;;
+ 	      ((and (eq 'byte-varbind (car lap1))
+ 		    (not (get (cadr lap1) 'binding-is-magic)))
+ 	       (setq tmp (cdr rest))
+ 	       (while
+ 		   (or
+ 		    (memq (caar (setq tmp (cdr tmp)))
+ 			  byte-compile-side-effect-free-dynamically-safe-ops)
+ 		    (and (eq (caar tmp) 'byte-varref)
+ 			 (not (eq (cadr (car tmp)) (cadr lap1))))))
+ 	       (when (eq 'byte-unbind (caar tmp))
+ 		 ;; Avoid evalling this crap when not logging anyway
+ 		 (when (memq byte-optimize-log '(t lap))
+ 		   (let ((format-string)
+ 			 (args))
+ 		     (if (and (= (aref byte-stack+-info (symbol-value (car lap0)))
+ 				 1)
+ 			      (memq (car lap0) side-effect-free))
+ 			 (setq format-string
+ 			       "  %s %s [car/cdr/ ...] %s\t-->\t[car/cdr/ ...]"
+ 			       args (list lap0 lap1 (car tmp)))
+ 		       (setq format-string
+ 			     "  %s [car/cdr/ ...] %s\t-->\t%s [car/cdr/ ...]"
+ 			     args (list lap1 (car tmp) (cons 'byte-discard 0))))
+ 		     (when (> (cdar tmp) 1)
+ 		       (setq format-string (concat format-string " %s"))
+ 		       (nconc args (list (cons 'byte-unbind (1- (cdar tmp))))))
+ 		     (apply 'byte-compile-log-lap-1 format-string args)))
+ 		 ;; Do the real work
+ 		 (if (and (= (aref byte-stack+-info (symbol-value (car lap0)))
+ 			     1)
+ 			  (memq (car lap0) side-effect-free))
+ 		     ;; Optimization: throw const/dup/... varbind right away.
+ 		     (progn
+ 		       (setcar rest (nth 2 rest))
+ 		       (setcdr rest (nthcdr 3 rest)))
+ 		   (setcar lap1 'byte-discard)
+ 		   (setcdr lap1 0))
+ 		 (if (= (cdar tmp) 1)
+ 		     (progn
+ 		       ;; Throw away unbind-1
+ 		       (setcar tmp (nth 1 tmp))
+ 		       (setcdr tmp (nthcdr 2 tmp)))
+ 		   (setcdr (car tmp) (1- (cdar tmp))))
+ 		 (setq keep-going t)))
+ 	      ;;
  	      ;; X: varref-Y    ...     varset-Y goto-X  -->
  	      ;; X: varref-Y Z: ... dup varset-Y goto-Z
  	      ;; (varset-X goto-BACK, BACK: varref-X --> copy the varref down.)