;;; byte-opt.el --- the optimization passes of the emacs-lisp byte compiler
-;; Copyright (C) 1991, 1994, 2000, 2001, 2002, 2003, 2004,
-;; 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+;; Copyright (C) 1991, 1994, 2000-2011 Free Software Foundation, Inc.
;; Author: Jamie Zawinski <jwz@lucid.com>
;; Hallvard Furuseth <hbf@ulrik.uio.no>
;; Maintainer: FSF
;; Keywords: internal
+;; Package: emacs
;; This file is part of GNU Emacs.
form))
((or (byte-code-function-p fn)
(eq 'lambda (car-safe fn)))
- (byte-optimize-form-code-walker
- (byte-compile-unfold-lambda form)
- for-effect))
+ (let ((newform (byte-compile-unfold-lambda form)))
+ (if (eq newform form)
+ ;; Some error occurred, avoid infinite recursion
+ form
+ (byte-optimize-form-code-walker newform for-effect))))
((memq fn '(let let*))
;; recursively enter the optimizer for the bindings and body
;; of a let or let*. This for depth-firstness: forms that
(list (apply fun (nreverse constants)))))))))
form))
+(defsubst byte-compile-butlast (form)
+ (nreverse (cdr (reverse form))))
+
(defun byte-optimize-plus (form)
- (setq form (byte-optimize-delay-constants-math form 1 '+))
+ ;; Don't call `byte-optimize-delay-constants-math' (bug#1334).
+ ;;(setq form (byte-optimize-delay-constants-math form 1 '+))
(if (memq 0 form) (setq form (delq 0 (copy-sequence form))))
- ;;(setq form (byte-optimize-associative-two-args-math form))
- (cond ((null (cdr form))
- (condition-case ()
- (eval form)
- (error form)))
-;;; It is not safe to delete the function entirely
-;;; (actually, it would be safe if we know the sole arg
-;;; is not a marker).
-;;; ((null (cdr (cdr form))) (nth 1 form))
- ((null (cddr form))
- (if (numberp (nth 1 form))
- (nth 1 form)
- form))
- ((and (null (nthcdr 3 form))
- (or (memq (nth 1 form) '(1 -1))
- (memq (nth 2 form) '(1 -1))))
- ;; Optimize (+ x 1) into (1+ x) and (+ x -1) into (1- x).
- (let ((integer
- (if (memq (nth 1 form) '(1 -1))
- (nth 1 form)
- (nth 2 form)))
- (other
- (if (memq (nth 1 form) '(1 -1))
- (nth 2 form)
- (nth 1 form))))
- (list (if (eq integer 1) '1+ '1-)
- other)))
- (t form)))
+ ;; For (+ constants...), byte-optimize-predicate does the work.
+ (when (memq nil (mapcar 'numberp (cdr form)))
+ (cond
+ ;; (+ x 1) --> (1+ x) and (+ x -1) --> (1- x).
+ ((and (= (length form) 3)
+ (or (memq (nth 1 form) '(1 -1))
+ (memq (nth 2 form) '(1 -1))))
+ (let (integer other)
+ (if (memq (nth 1 form) '(1 -1))
+ (setq integer (nth 1 form) other (nth 2 form))
+ (setq integer (nth 2 form) other (nth 1 form)))
+ (setq form
+ (list (if (eq integer 1) '1+ '1-) other))))
+ ;; Here, we could also do
+ ;; (+ x y ... 1) --> (1+ (+ x y ...))
+ ;; (+ x y ... -1) --> (1- (+ x y ...))
+ ;; The resulting bytecode is smaller, but is it faster? -- cyd
+ ))
+ (byte-optimize-predicate form))
(defun byte-optimize-minus (form)
- ;; Put constants at the end, except the last constant.
- (setq form (byte-optimize-delay-constants-math form 2 '+))
- ;; Now only first and last element can be a number.
- (let ((last (car (reverse (nthcdr 3 form)))))
- (cond ((eq 0 last)
- ;; (- x y ... 0) --> (- x y ...)
- (setq form (copy-sequence form))
- (setcdr (cdr (cdr form)) (delq 0 (nthcdr 3 form))))
- ((equal (nthcdr 2 form) '(1))
- (setq form (list '1- (nth 1 form))))
- ((equal (nthcdr 2 form) '(-1))
- (setq form (list '1+ (nth 1 form))))
- ;; If form is (- CONST foo... CONST), merge first and last.
- ((and (numberp (nth 1 form))
- (numberp last))
- (setq form (nconc (list '- (- (nth 1 form) last) (nth 2 form))
- (delq last (copy-sequence (nthcdr 3 form))))))))
-;;; It is not safe to delete the function entirely
-;;; (actually, it would be safe if we know the sole arg
-;;; is not a marker).
-;;; (if (eq (nth 2 form) 0)
-;;; (nth 1 form) ; (- x 0) --> x
- (byte-optimize-predicate
- (if (and (null (cdr (cdr (cdr form))))
- (eq (nth 1 form) 0)) ; (- 0 x) --> (- x)
- (cons (car form) (cdr (cdr form)))
- form))
-;;; )
- )
+ ;; Don't call `byte-optimize-delay-constants-math' (bug#1334).
+ ;;(setq form (byte-optimize-delay-constants-math form 2 '+))
+ ;; Remove zeros.
+ (when (and (nthcdr 3 form)
+ (memq 0 (cddr form)))
+ (setq form (nconc (list (car form) (cadr form))
+ (delq 0 (copy-sequence (cddr form)))))
+ ;; After the above, we must turn (- x) back into (- x 0)
+ (or (cddr form)
+ (setq form (nconc form (list 0)))))
+ ;; For (- constants..), byte-optimize-predicate does the work.
+ (when (memq nil (mapcar 'numberp (cdr form)))
+ (cond
+ ;; (- x 1) --> (1- x)
+ ((equal (nthcdr 2 form) '(1))
+ (setq form (list '1- (nth 1 form))))
+ ;; (- x -1) --> (1+ x)
+ ((equal (nthcdr 2 form) '(-1))
+ (setq form (list '1+ (nth 1 form))))
+ ;; (- 0 x) --> (- x)
+ ((and (eq (nth 1 form) 0)
+ (= (length form) 3))
+ (setq form (list '- (nth 2 form))))
+ ;; Here, we could also do
+ ;; (- x y ... 1) --> (1- (- x y ...))
+ ;; (- x y ... -1) --> (1+ (- x y ...))
+ ;; The resulting bytecode is smaller, but is it faster? -- cyd
+ ))
+ (byte-optimize-predicate form))
(defun byte-optimize-multiply (form)
(setq form (byte-optimize-delay-constants-math form 1 '*))
- ;; If there is a constant in FORM, it is now the last element.
- (cond ((null (cdr form)) 1)
-;;; It is not safe to delete the function entirely
-;;; (actually, it would be safe if we know the sole arg
-;;; is not a marker or if it appears in other arithmetic).
-;;; ((null (cdr (cdr form))) (nth 1 form))
- ((let ((last (car (reverse form))))
- (cond ((eq 0 last) (cons 'progn (cdr form)))
- ((eq 1 last) (delq 1 (copy-sequence form)))
- ((eq -1 last) (list '- (delq -1 (copy-sequence form))))
- ((and (eq 2 last)
- (memq t (mapcar 'symbolp (cdr form))))
- (prog1 (setq form (delq 2 (copy-sequence form)))
- (while (not (symbolp (car (setq form (cdr form))))))
- (setcar form (list '+ (car form) (car form)))))
- (form))))))
-
-(defsubst byte-compile-butlast (form)
- (nreverse (cdr (reverse form))))
+ ;; For (* constants..), byte-optimize-predicate does the work.
+ (when (memq nil (mapcar 'numberp (cdr form)))
+ ;; After `byte-optimize-predicate', if there is a INTEGER constant
+ ;; in FORM, it is in the last element.
+ (let ((last (car (reverse (cdr form)))))
+ (cond
+ ;; Would handling (* ... 0) here cause floating point errors?
+ ;; See bug#1334.
+ ((eq 1 last) (setq form (byte-compile-butlast form)))
+ ((eq -1 last)
+ (setq form (list '- (if (nthcdr 3 form)
+ (byte-compile-butlast form)
+ (nth 1 form))))))))
+ (byte-optimize-predicate form))
(defun byte-optimize-divide (form)
(setq form (byte-optimize-delay-constants-math form 2 '*))
+ ;; After `byte-optimize-predicate', if there is a INTEGER constant
+ ;; in FORM, it is in the last element.
(let ((last (car (reverse (cdr (cdr form))))))
- (if (numberp last)
- (cond ((= (length form) 3)
- (if (and (numberp (nth 1 form))
- (not (zerop last))
- (condition-case nil
- (/ (nth 1 form) last)
- (error nil)))
- (setq form (list 'progn (/ (nth 1 form) last)))))
- ((= last 1)
- (setq form (byte-compile-butlast form)))
- ((numberp (nth 1 form))
- (setq form (cons (car form)
- (cons (/ (nth 1 form) last)
- (byte-compile-butlast (cdr (cdr form)))))
- last nil))))
(cond
-;;; ((null (cdr (cdr form)))
-;;; (nth 1 form))
- ((eq (nth 1 form) 0)
- (append '(progn) (cdr (cdr form)) '(0)))
- ((eq last -1)
- (list '- (if (nthcdr 3 form)
- (byte-compile-butlast form)
- (nth 1 form))))
- (form))))
+ ;; Runtime error (leave it intact).
+ ((or (null last)
+ (eq last 0)
+ (memql 0.0 (cddr form))))
+ ;; No constants in expression
+ ((not (numberp last)))
+ ;; For (* constants..), byte-optimize-predicate does the work.
+ ((null (memq nil (mapcar 'numberp (cdr form)))))
+ ;; (/ x y.. 1) --> (/ x y..)
+ ((and (eq last 1) (nthcdr 3 form))
+ (setq form (byte-compile-butlast form)))
+ ;; (/ x -1), (/ x .. -1) --> (- x), (- (/ x ..))
+ ((eq last -1)
+ (setq form (list '- (if (nthcdr 3 form)
+ (byte-compile-butlast form)
+ (nth 1 form)))))))
+ (byte-optimize-predicate form))
(defun byte-optimize-logmumble (form)
(setq form (byte-optimize-delay-constants-math form 1 (car form)))
next-window nth nthcdr number-to-string
parse-colon-path plist-get plist-member
prefix-numeric-value previous-window prin1-to-string propertize
+ degrees-to-radians
radians-to-degrees rassq rassoc read-from-string regexp-quote
region-beginning region-end reverse round
sin sqrt string string< string= string-equal string-lessp string-to-char
"Don't call this!"
;; fetch and return the offset for the current opcode.
;; return nil if this opcode has no offset
- ;; OP, PTR and BYTES are used and set dynamically
- (defvar op)
- (defvar ptr)
- (defvar bytes)
- (cond ((< op byte-nth)
- (let ((tem (logand op 7)))
- (setq op (logand op 248))
+ ;; Used and set dynamically in byte-decompile-bytecode-1.
+ (defvar bytedecomp-op)
+ (defvar bytedecomp-ptr)
+ (defvar bytedecomp-bytes)
+ (cond ((< bytedecomp-op byte-nth)
+ (let ((tem (logand bytedecomp-op 7)))
+ (setq bytedecomp-op (logand bytedecomp-op 248))
(cond ((eq tem 6)
- (setq ptr (1+ ptr)) ;offset in next byte
- (aref bytes ptr))
+ ;; Offset in next byte.
+ (setq bytedecomp-ptr (1+ bytedecomp-ptr))
+ (aref bytedecomp-bytes bytedecomp-ptr))
((eq tem 7)
- (setq ptr (1+ ptr)) ;offset in next 2 bytes
- (+ (aref bytes ptr)
- (progn (setq ptr (1+ ptr))
- (lsh (aref bytes ptr) 8))))
+ ;; Offset in next 2 bytes.
+ (setq bytedecomp-ptr (1+ bytedecomp-ptr))
+ (+ (aref bytedecomp-bytes bytedecomp-ptr)
+ (progn (setq bytedecomp-ptr (1+ bytedecomp-ptr))
+ (lsh (aref bytedecomp-bytes bytedecomp-ptr) 8))))
(t tem)))) ;offset was in opcode
- ((>= op byte-constant)
- (prog1 (- op byte-constant) ;offset in opcode
- (setq op byte-constant)))
- ((and (>= op byte-constant2)
- (<= op byte-goto-if-not-nil-else-pop))
- (setq ptr (1+ ptr)) ;offset in next 2 bytes
- (+ (aref bytes ptr)
- (progn (setq ptr (1+ ptr))
- (lsh (aref bytes ptr) 8))))
- ((and (>= op byte-listN)
- (<= op byte-insertN))
- (setq ptr (1+ ptr)) ;offset in next byte
- (aref bytes ptr))))
+ ((>= bytedecomp-op byte-constant)
+ (prog1 (- bytedecomp-op byte-constant) ;offset in opcode
+ (setq bytedecomp-op byte-constant)))
+ ((and (>= bytedecomp-op byte-constant2)
+ (<= bytedecomp-op byte-goto-if-not-nil-else-pop))
+ ;; Offset in next 2 bytes.
+ (setq bytedecomp-ptr (1+ bytedecomp-ptr))
+ (+ (aref bytedecomp-bytes bytedecomp-ptr)
+ (progn (setq bytedecomp-ptr (1+ bytedecomp-ptr))
+ (lsh (aref bytedecomp-bytes bytedecomp-ptr) 8))))
+ ((and (>= bytedecomp-op byte-listN)
+ (<= bytedecomp-op byte-insertN))
+ (setq bytedecomp-ptr (1+ bytedecomp-ptr)) ;offset in next byte
+ (aref bytedecomp-bytes bytedecomp-ptr))))
;; This de-compiler is used for inline expansion of compiled functions,
;; If MAKE-SPLICEABLE is nil, we are being called for the disassembler.
;; In that case, we put a pc value into the list
;; before each insn (or its label).
-(defun byte-decompile-bytecode-1 (bytes constvec &optional make-spliceable)
- (let ((length (length bytes))
- (ptr 0) optr tags op offset
+(defun byte-decompile-bytecode-1 (bytedecomp-bytes constvec
+ &optional make-spliceable)
+ (let ((length (length bytedecomp-bytes))
+ (bytedecomp-ptr 0) optr tags bytedecomp-op offset
lap tmp
endtag)
- (while (not (= ptr length))
+ (while (not (= bytedecomp-ptr length))
(or make-spliceable
- (setq lap (cons ptr lap)))
- (setq op (aref bytes ptr)
- optr ptr
+ (setq lap (cons bytedecomp-ptr lap)))
+ (setq bytedecomp-op (aref bytedecomp-bytes bytedecomp-ptr)
+ optr bytedecomp-ptr
offset (disassemble-offset)) ; this does dynamic-scope magic
- (setq op (aref byte-code-vector op))
- (cond ((memq op byte-goto-ops)
+ (setq bytedecomp-op (aref byte-code-vector bytedecomp-op))
+ (cond ((memq bytedecomp-op byte-goto-ops)
;; it's a pc
(setq offset
(cdr (or (assq offset tags)
(cons (cons offset
(byte-compile-make-tag))
tags)))))))
- ((cond ((eq op 'byte-constant2) (setq op 'byte-constant) t)
- ((memq op byte-constref-ops)))
+ ((cond ((eq bytedecomp-op 'byte-constant2)
+ (setq bytedecomp-op 'byte-constant) t)
+ ((memq bytedecomp-op byte-constref-ops)))
(setq tmp (if (>= offset (length constvec))
(list 'out-of-range offset)
(aref constvec offset))
- offset (if (eq op 'byte-constant)
+ offset (if (eq bytedecomp-op 'byte-constant)
(byte-compile-get-constant tmp)
(or (assq tmp byte-compile-variables)
(car (setq byte-compile-variables
(cons (list tmp)
byte-compile-variables)))))))
((and make-spliceable
- (eq op 'byte-return))
- (if (= ptr (1- length))
- (setq op nil)
+ (eq bytedecomp-op 'byte-return))
+ (if (= bytedecomp-ptr (1- length))
+ (setq bytedecomp-op nil)
(setq offset (or endtag (setq endtag (byte-compile-make-tag)))
- op 'byte-goto))))
+ bytedecomp-op 'byte-goto))))
;; lap = ( [ (pc . (op . arg)) ]* )
- (setq lap (cons (cons optr (cons op (or offset 0)))
+ (setq lap (cons (cons optr (cons bytedecomp-op (or offset 0)))
lap))
- (setq ptr (1+ ptr)))
+ (setq bytedecomp-ptr (1+ bytedecomp-ptr)))
;; take off the dummy nil op that we replaced a trailing "return" with.
(let ((rest lap))
(while rest
byte-optimize-lapcode))))
nil)
-;; arch-tag: 0f14076b-737e-4bef-aae6-908826ec1ff1
;;; byte-opt.el ends here
HCoop / bpt / emacs.git / blobdiff