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bba752f8 | 1 | ;;; byte-opt.el --- the optimization passes of the emacs-lisp byte compiler -*- lexical-binding: t -*- |
3eac9910 | 2 | |
ab422c4d | 3 | ;; Copyright (C) 1991, 1994, 2000-2013 Free Software Foundation, Inc. |
3eac9910 JB |
4 | |
5 | ;; Author: Jamie Zawinski <jwz@lucid.com> | |
6 | ;; Hallvard Furuseth <hbf@ulrik.uio.no> | |
e1f0df62 | 7 | ;; Maintainer: FSF |
3eac9910 | 8 | ;; Keywords: internal |
bd78fa1d | 9 | ;; Package: emacs |
1c393159 JB |
10 | |
11 | ;; This file is part of GNU Emacs. | |
12 | ||
d6cba7ae | 13 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
1c393159 | 14 | ;; it under the terms of the GNU General Public License as published by |
d6cba7ae GM |
15 | ;; the Free Software Foundation, either version 3 of the License, or |
16 | ;; (at your option) any later version. | |
1c393159 JB |
17 | |
18 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | ;; GNU General Public License for more details. | |
22 | ||
23 | ;; You should have received a copy of the GNU General Public License | |
d6cba7ae | 24 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
1c393159 | 25 | |
3eac9910 JB |
26 | ;;; Commentary: |
27 | ||
b578f267 EN |
28 | ;; ======================================================================== |
29 | ;; "No matter how hard you try, you can't make a racehorse out of a pig. | |
30 | ;; You can, however, make a faster pig." | |
31 | ;; | |
40fafc21 | 32 | ;; Or, to put it another way, the Emacs byte compiler is a VW Bug. This code |
a1506d29 | 33 | ;; makes it be a VW Bug with fuel injection and a turbocharger... You're |
b578f267 EN |
34 | ;; still not going to make it go faster than 70 mph, but it might be easier |
35 | ;; to get it there. | |
36 | ;; | |
1c393159 | 37 | |
b578f267 EN |
38 | ;; TO DO: |
39 | ;; | |
72d8b544 | 40 | ;; (apply (lambda (x &rest y) ...) 1 (foo)) |
b578f267 EN |
41 | ;; |
42 | ;; maintain a list of functions known not to access any global variables | |
43 | ;; (actually, give them a 'dynamically-safe property) and then | |
44 | ;; (let ( v1 v2 ... vM vN ) <...dynamically-safe...> ) ==> | |
45 | ;; (let ( v1 v2 ... vM ) vN <...dynamically-safe...> ) | |
46 | ;; by recursing on this, we might be able to eliminate the entire let. | |
47 | ;; However certain variables should never have their bindings optimized | |
48 | ;; away, because they affect everything. | |
49 | ;; (put 'debug-on-error 'binding-is-magic t) | |
50 | ;; (put 'debug-on-abort 'binding-is-magic t) | |
51 | ;; (put 'debug-on-next-call 'binding-is-magic t) | |
b578f267 EN |
52 | ;; (put 'inhibit-quit 'binding-is-magic t) |
53 | ;; (put 'quit-flag 'binding-is-magic t) | |
54 | ;; (put 't 'binding-is-magic t) | |
55 | ;; (put 'nil 'binding-is-magic t) | |
56 | ;; possibly also | |
57 | ;; (put 'gc-cons-threshold 'binding-is-magic t) | |
58 | ;; (put 'track-mouse 'binding-is-magic t) | |
59 | ;; others? | |
60 | ;; | |
61 | ;; Simple defsubsts often produce forms like | |
62 | ;; (let ((v1 (f1)) (v2 (f2)) ...) | |
63 | ;; (FN v1 v2 ...)) | |
a1506d29 | 64 | ;; It would be nice if we could optimize this to |
b578f267 EN |
65 | ;; (FN (f1) (f2) ...) |
66 | ;; but we can't unless FN is dynamically-safe (it might be dynamically | |
67 | ;; referring to the bindings that the lambda arglist established.) | |
68 | ;; One of the uncountable lossages introduced by dynamic scope... | |
69 | ;; | |
a1506d29 | 70 | ;; Maybe there should be a control-structure that says "turn on |
b578f267 EN |
71 | ;; fast-and-loose type-assumptive optimizations here." Then when |
72 | ;; we see a form like (car foo) we can from then on assume that | |
73 | ;; the variable foo is of type cons, and optimize based on that. | |
a1506d29 | 74 | ;; But, this won't win much because of (you guessed it) dynamic |
b578f267 EN |
75 | ;; scope. Anything down the stack could change the value. |
76 | ;; (Another reason it doesn't work is that it is perfectly valid | |
77 | ;; to call car with a null argument.) A better approach might | |
78 | ;; be to allow type-specification of the form | |
79 | ;; (put 'foo 'arg-types '(float (list integer) dynamic)) | |
80 | ;; (put 'foo 'result-type 'bool) | |
81 | ;; It should be possible to have these types checked to a certain | |
82 | ;; degree. | |
83 | ;; | |
84 | ;; collapse common subexpressions | |
85 | ;; | |
86 | ;; It would be nice if redundant sequences could be factored out as well, | |
87 | ;; when they are known to have no side-effects: | |
88 | ;; (list (+ a b c) (+ a b c)) --> a b add c add dup list-2 | |
89 | ;; but beware of traps like | |
90 | ;; (cons (list x y) (list x y)) | |
91 | ;; | |
92 | ;; Tail-recursion elimination is not really possible in Emacs Lisp. | |
93 | ;; Tail-recursion elimination is almost always impossible when all variables | |
94 | ;; have dynamic scope, but given that the "return" byteop requires the | |
95 | ;; binding stack to be empty (rather than emptying it itself), there can be | |
96 | ;; no truly tail-recursive Emacs Lisp functions that take any arguments or | |
97 | ;; make any bindings. | |
98 | ;; | |
99 | ;; Here is an example of an Emacs Lisp function which could safely be | |
100 | ;; byte-compiled tail-recursively: | |
101 | ;; | |
102 | ;; (defun tail-map (fn list) | |
103 | ;; (cond (list | |
104 | ;; (funcall fn (car list)) | |
105 | ;; (tail-map fn (cdr list))))) | |
106 | ;; | |
107 | ;; However, if there was even a single let-binding around the COND, | |
108 | ;; it could not be byte-compiled, because there would be an "unbind" | |
a1506d29 | 109 | ;; byte-op between the final "call" and "return." Adding a |
b578f267 EN |
110 | ;; Bunbind_all byteop would fix this. |
111 | ;; | |
112 | ;; (defun foo (x y z) ... (foo a b c)) | |
113 | ;; ... (const foo) (varref a) (varref b) (varref c) (call 3) END: (return) | |
114 | ;; ... (varref a) (varbind x) (varref b) (varbind y) (varref c) (varbind z) (goto 0) END: (unbind-all) (return) | |
115 | ;; ... (varref a) (varset x) (varref b) (varset y) (varref c) (varset z) (goto 0) END: (return) | |
116 | ;; | |
117 | ;; this also can be considered tail recursion: | |
118 | ;; | |
119 | ;; ... (const foo) (varref a) (call 1) (goto X) ... X: (return) | |
120 | ;; could generalize this by doing the optimization | |
121 | ;; (goto X) ... X: (return) --> (return) | |
122 | ;; | |
123 | ;; But this doesn't solve all of the problems: although by doing tail- | |
124 | ;; recursion elimination in this way, the call-stack does not grow, the | |
125 | ;; binding-stack would grow with each recursive step, and would eventually | |
126 | ;; overflow. I don't believe there is any way around this without lexical | |
127 | ;; scope. | |
128 | ;; | |
129 | ;; Wouldn't it be nice if Emacs Lisp had lexical scope. | |
130 | ;; | |
a1506d29 JB |
131 | ;; Idea: the form (lexical-scope) in a file means that the file may be |
132 | ;; compiled lexically. This proclamation is file-local. Then, within | |
b578f267 EN |
133 | ;; that file, "let" would establish lexical bindings, and "let-dynamic" |
134 | ;; would do things the old way. (Or we could use CL "declare" forms.) | |
135 | ;; We'd have to notice defvars and defconsts, since those variables should | |
136 | ;; always be dynamic, and attempting to do a lexical binding of them | |
137 | ;; should simply do a dynamic binding instead. | |
e4769531 | 138 | ;; But! We need to know about variables that were not necessarily defvared |
b578f267 EN |
139 | ;; in the file being compiled (doing a boundp check isn't good enough.) |
140 | ;; Fdefvar() would have to be modified to add something to the plist. | |
141 | ;; | |
a1506d29 JB |
142 | ;; A major disadvantage of this scheme is that the interpreter and compiler |
143 | ;; would have different semantics for files compiled with (dynamic-scope). | |
b578f267 | 144 | ;; Since this would be a file-local optimization, there would be no way to |
a1506d29 | 145 | ;; modify the interpreter to obey this (unless the loader was hacked |
b578f267 | 146 | ;; in some grody way, but that's a really bad idea.) |
97e6527f KH |
147 | |
148 | ;; Other things to consider: | |
149 | ||
6b61353c KH |
150 | ;; ;; Associative math should recognize subcalls to identical function: |
151 | ;; (disassemble (lambda (x) (+ (+ (foo) 1) (+ (bar) 2)))) | |
152 | ;; ;; This should generate the same as (1+ x) and (1- x) | |
c1fe6512 | 153 | |
6b61353c KH |
154 | ;; (disassemble (lambda (x) (cons (+ x 1) (- x 1)))) |
155 | ;; ;; An awful lot of functions always return a non-nil value. If they're | |
156 | ;; ;; error free also they may act as true-constants. | |
c1fe6512 | 157 | |
6b61353c KH |
158 | ;; (disassemble (lambda (x) (and (point) (foo)))) |
159 | ;; ;; When | |
160 | ;; ;; - all but one arguments to a function are constant | |
161 | ;; ;; - the non-constant argument is an if-expression (cond-expression?) | |
162 | ;; ;; then the outer function can be distributed. If the guarding | |
163 | ;; ;; condition is side-effect-free [assignment-free] then the other | |
164 | ;; ;; arguments may be any expressions. Since, however, the code size | |
165 | ;; ;; can increase this way they should be "simple". Compare: | |
c1fe6512 | 166 | |
6b61353c KH |
167 | ;; (disassemble (lambda (x) (eq (if (point) 'a 'b) 'c))) |
168 | ;; (disassemble (lambda (x) (if (point) (eq 'a 'c) (eq 'b 'c)))) | |
c1fe6512 | 169 | |
6b61353c KH |
170 | ;; ;; (car (cons A B)) -> (prog1 A B) |
171 | ;; (disassemble (lambda (x) (car (cons (foo) 42)))) | |
c1fe6512 | 172 | |
6b61353c KH |
173 | ;; ;; (cdr (cons A B)) -> (progn A B) |
174 | ;; (disassemble (lambda (x) (cdr (cons 42 (foo))))) | |
c1fe6512 | 175 | |
6b61353c KH |
176 | ;; ;; (car (list A B ...)) -> (prog1 A B ...) |
177 | ;; (disassemble (lambda (x) (car (list (foo) 42 (bar))))) | |
c1fe6512 | 178 | |
6b61353c KH |
179 | ;; ;; (cdr (list A B ...)) -> (progn A (list B ...)) |
180 | ;; (disassemble (lambda (x) (cdr (list 42 (foo) (bar))))) | |
97e6527f | 181 | |
1c393159 | 182 | |
3eac9910 | 183 | ;;; Code: |
1c393159 | 184 | |
c144230d | 185 | (require 'bytecomp) |
f80efb86 | 186 | (eval-when-compile (require 'cl-lib)) |
4dd1c416 | 187 | (require 'macroexp) |
c144230d | 188 | |
1c393159 | 189 | (defun byte-compile-log-lap-1 (format &rest args) |
a647cb26 SM |
190 | ;; Newer byte codes for stack-ref make the slot 0 non-nil again. |
191 | ;; But the "old disassembler" is *really* ancient by now. | |
192 | ;; (if (aref byte-code-vector 0) | |
193 | ;; (error "The old version of the disassembler is loaded. Reload new-bytecomp as well")) | |
1c393159 JB |
194 | (byte-compile-log-1 |
195 | (apply 'format format | |
196 | (let (c a) | |
72d8b544 | 197 | (mapcar (lambda (arg) |
1c393159 JB |
198 | (if (not (consp arg)) |
199 | (if (and (symbolp arg) | |
200 | (string-match "^byte-" (symbol-name arg))) | |
201 | (intern (substring (symbol-name arg) 5)) | |
202 | arg) | |
203 | (if (integerp (setq c (car arg))) | |
204 | (error "non-symbolic byte-op %s" c)) | |
205 | (if (eq c 'TAG) | |
206 | (setq c arg) | |
207 | (setq a (cond ((memq c byte-goto-ops) | |
208 | (car (cdr (cdr arg)))) | |
209 | ((memq c byte-constref-ops) | |
210 | (car (cdr arg))) | |
211 | (t (cdr arg)))) | |
212 | (setq c (symbol-name c)) | |
213 | (if (string-match "^byte-." c) | |
214 | (setq c (intern (substring c 5))))) | |
215 | (if (eq c 'constant) (setq c 'const)) | |
216 | (if (and (eq (cdr arg) 0) | |
217 | (not (memq c '(unbind call const)))) | |
218 | c | |
219 | (format "(%s %s)" c a)))) | |
220 | args))))) | |
221 | ||
222 | (defmacro byte-compile-log-lap (format-string &rest args) | |
6b61353c KH |
223 | `(and (memq byte-optimize-log '(t byte)) |
224 | (byte-compile-log-lap-1 ,format-string ,@args))) | |
1c393159 JB |
225 | |
226 | \f | |
227 | ;;; byte-compile optimizers to support inlining | |
228 | ||
229 | (put 'inline 'byte-optimizer 'byte-optimize-inline-handler) | |
230 | ||
231 | (defun byte-optimize-inline-handler (form) | |
232 | "byte-optimize-handler for the `inline' special-form." | |
233 | (cons 'progn | |
234 | (mapcar | |
72d8b544 | 235 | (lambda (sexp) |
08d72d13 SM |
236 | (let ((f (car-safe sexp))) |
237 | (if (and (symbolp f) | |
238 | (or (cdr (assq f byte-compile-function-environment)) | |
239 | (not (or (not (fboundp f)) | |
240 | (cdr (assq f byte-compile-macro-environment)) | |
241 | (and (consp (setq f (symbol-function f))) | |
242 | (eq (car f) 'macro)) | |
243 | (subrp f))))) | |
244 | (byte-compile-inline-expand sexp) | |
245 | sexp))) | |
1c393159 JB |
246 | (cdr form)))) |
247 | ||
1c393159 JB |
248 | (defun byte-compile-inline-expand (form) |
249 | (let* ((name (car form)) | |
ca105506 SM |
250 | (localfn (cdr (assq name byte-compile-function-environment))) |
251 | (fn (or localfn (and (fboundp name) (symbol-function name))))) | |
7abaf5cc SM |
252 | (when (autoloadp fn) |
253 | (autoload-do-load fn) | |
ca105506 SM |
254 | (setq fn (or (and (fboundp name) (symbol-function name)) |
255 | (cdr (assq name byte-compile-function-environment))))) | |
256 | (pcase fn | |
257 | (`nil | |
258 | (byte-compile-warn "attempt to inline `%s' before it was defined" | |
259 | name) | |
260 | form) | |
261 | (`(autoload . ,_) | |
262 | (error "File `%s' didn't define `%s'" (nth 1 fn) name)) | |
263 | ((and (pred symbolp) (guard (not (eq fn t)))) ;A function alias. | |
264 | (byte-compile-inline-expand (cons fn (cdr form)))) | |
29a4dcb0 SM |
265 | ((pred byte-code-function-p) |
266 | ;; (message "Inlining byte-code for %S!" name) | |
267 | ;; The byte-code will be really inlined in byte-compile-unfold-bcf. | |
268 | `(,fn ,@(cdr form))) | |
c207708c | 269 | ((or `(lambda . ,_) `(closure . ,_)) |
29a4dcb0 | 270 | (if (not (or (eq fn localfn) ;From the same file => same mode. |
c207708c SM |
271 | (eq (car fn) ;Same mode. |
272 | (if lexical-binding 'closure 'lambda)))) | |
29a4dcb0 SM |
273 | ;; While byte-compile-unfold-bcf can inline dynbind byte-code into |
274 | ;; letbind byte-code (or any other combination for that matter), we | |
275 | ;; can only inline dynbind source into dynbind source or letbind | |
276 | ;; source into letbind source. | |
c207708c SM |
277 | (progn |
278 | ;; We can of course byte-compile the inlined function | |
279 | ;; first, and then inline its byte-code. | |
280 | (byte-compile name) | |
281 | `(,(symbol-function name) ,@(cdr form))) | |
282 | (let ((newfn (if (eq fn localfn) | |
283 | ;; If `fn' is from the same file, it has already | |
284 | ;; been preprocessed! | |
285 | `(function ,fn) | |
286 | (byte-compile-preprocess | |
e3ac1281 | 287 | (byte-compile--reify-function fn))))) |
c207708c SM |
288 | (if (eq (car-safe newfn) 'function) |
289 | (byte-compile-unfold-lambda `(,(cadr newfn) ,@(cdr form))) | |
0b31660d | 290 | ;; This can happen because of macroexp-warn-and-return &co. |
c207708c SM |
291 | (byte-compile-log-warning |
292 | (format "Inlining closure %S failed" name)) | |
293 | form)))) | |
ca105506 SM |
294 | |
295 | (t ;; Give up on inlining. | |
296 | form)))) | |
1c393159 | 297 | |
6b61353c | 298 | ;; ((lambda ...) ...) |
1c393159 | 299 | (defun byte-compile-unfold-lambda (form &optional name) |
d032d5e7 | 300 | ;; In lexical-binding mode, let and functions don't bind vars in the same way |
2ec42da9 SM |
301 | ;; (let obey special-variable-p, but functions don't). But luckily, this |
302 | ;; doesn't matter here, because function's behavior is underspecified so it | |
303 | ;; can safely be turned into a `let', even though the reverse is not true. | |
1c393159 JB |
304 | (or name (setq name "anonymous lambda")) |
305 | (let ((lambda (car form)) | |
306 | (values (cdr form))) | |
1c393159 JB |
307 | (let ((arglist (nth 1 lambda)) |
308 | (body (cdr (cdr lambda))) | |
309 | optionalp restp | |
310 | bindings) | |
311 | (if (and (stringp (car body)) (cdr body)) | |
312 | (setq body (cdr body))) | |
313 | (if (and (consp (car body)) (eq 'interactive (car (car body)))) | |
314 | (setq body (cdr body))) | |
29a4dcb0 | 315 | ;; FIXME: The checks below do not belong in an optimization phase. |
1c393159 JB |
316 | (while arglist |
317 | (cond ((eq (car arglist) '&optional) | |
318 | ;; ok, I'll let this slide because funcall_lambda() does... | |
319 | ;; (if optionalp (error "multiple &optional keywords in %s" name)) | |
320 | (if restp (error "&optional found after &rest in %s" name)) | |
321 | (if (null (cdr arglist)) | |
322 | (error "nothing after &optional in %s" name)) | |
323 | (setq optionalp t)) | |
324 | ((eq (car arglist) '&rest) | |
325 | ;; ...but it is by no stretch of the imagination a reasonable | |
326 | ;; thing that funcall_lambda() allows (&rest x y) and | |
327 | ;; (&rest x &optional y) in arglists. | |
328 | (if (null (cdr arglist)) | |
329 | (error "nothing after &rest in %s" name)) | |
330 | (if (cdr (cdr arglist)) | |
331 | (error "multiple vars after &rest in %s" name)) | |
332 | (setq restp t)) | |
333 | (restp | |
334 | (setq bindings (cons (list (car arglist) | |
335 | (and values (cons 'list values))) | |
336 | bindings) | |
337 | values nil)) | |
338 | ((and (not optionalp) (null values)) | |
244bbdc5 | 339 | (byte-compile-warn "attempt to open-code `%s' with too few arguments" name) |
1c393159 JB |
340 | (setq arglist nil values 'too-few)) |
341 | (t | |
342 | (setq bindings (cons (list (car arglist) (car values)) | |
343 | bindings) | |
344 | values (cdr values)))) | |
345 | (setq arglist (cdr arglist))) | |
346 | (if values | |
347 | (progn | |
348 | (or (eq values 'too-few) | |
349 | (byte-compile-warn | |
244bbdc5 | 350 | "attempt to open-code `%s' with too many arguments" name)) |
1c393159 | 351 | form) |
a1506d29 | 352 | |
936ae731 GM |
353 | ;; The following leads to infinite recursion when loading a |
354 | ;; file containing `(defsubst f () (f))', and then trying to | |
355 | ;; byte-compile that file. | |
356 | ;(setq body (mapcar 'byte-optimize-form body))) | |
a1506d29 JB |
357 | |
358 | (let ((newform | |
1c393159 JB |
359 | (if bindings |
360 | (cons 'let (cons (nreverse bindings) body)) | |
361 | (cons 'progn body)))) | |
362 | (byte-compile-log " %s\t==>\t%s" form newform) | |
363 | newform))))) | |
364 | ||
365 | \f | |
366 | ;;; implementing source-level optimizers | |
367 | ||
2ec42da9 | 368 | (defun byte-optimize-form-code-walker (form for-effect) |
1c393159 JB |
369 | ;; |
370 | ;; For normal function calls, We can just mapcar the optimizer the cdr. But | |
371 | ;; we need to have special knowledge of the syntax of the special forms | |
372 | ;; like let and defun (that's why they're special forms :-). (Actually, | |
373 | ;; the important aspect is that they are subrs that don't evaluate all of | |
374 | ;; their args.) | |
375 | ;; | |
2ec42da9 | 376 | (let ((fn (car-safe form)) |
1c393159 JB |
377 | tmp) |
378 | (cond ((not (consp form)) | |
379 | (if (not (and for-effect | |
380 | (or byte-compile-delete-errors | |
381 | (not (symbolp form)) | |
382 | (eq form t)))) | |
383 | form)) | |
384 | ((eq fn 'quote) | |
385 | (if (cdr (cdr form)) | |
244bbdc5 | 386 | (byte-compile-warn "malformed quote form: `%s'" |
1c393159 JB |
387 | (prin1-to-string form))) |
388 | ;; map (quote nil) to nil to simplify optimizer logic. | |
389 | ;; map quoted constants to nil if for-effect (just because). | |
390 | (and (nth 1 form) | |
391 | (not for-effect) | |
392 | form)) | |
29a4dcb0 | 393 | ((eq 'lambda (car-safe fn)) |
c19f76a1 AS |
394 | (let ((newform (byte-compile-unfold-lambda form))) |
395 | (if (eq newform form) | |
c0943d3d | 396 | ;; Some error occurred, avoid infinite recursion |
c19f76a1 AS |
397 | form |
398 | (byte-optimize-form-code-walker newform for-effect)))) | |
1c393159 JB |
399 | ((memq fn '(let let*)) |
400 | ;; recursively enter the optimizer for the bindings and body | |
401 | ;; of a let or let*. This for depth-firstness: forms that | |
402 | ;; are more deeply nested are optimized first. | |
403 | (cons fn | |
404 | (cons | |
72d8b544 | 405 | (mapcar (lambda (binding) |
1c393159 JB |
406 | (if (symbolp binding) |
407 | binding | |
408 | (if (cdr (cdr binding)) | |
244bbdc5 | 409 | (byte-compile-warn "malformed let binding: `%s'" |
1c393159 JB |
410 | (prin1-to-string binding))) |
411 | (list (car binding) | |
412 | (byte-optimize-form (nth 1 binding) nil)))) | |
413 | (nth 1 form)) | |
414 | (byte-optimize-body (cdr (cdr form)) for-effect)))) | |
415 | ((eq fn 'cond) | |
416 | (cons fn | |
72d8b544 | 417 | (mapcar (lambda (clause) |
1c393159 JB |
418 | (if (consp clause) |
419 | (cons | |
420 | (byte-optimize-form (car clause) nil) | |
421 | (byte-optimize-body (cdr clause) for-effect)) | |
244bbdc5 | 422 | (byte-compile-warn "malformed cond form: `%s'" |
1c393159 JB |
423 | (prin1-to-string clause)) |
424 | clause)) | |
425 | (cdr form)))) | |
426 | ((eq fn 'progn) | |
4dd1c416 | 427 | ;; As an extra added bonus, this simplifies (progn <x>) --> <x>. |
1c393159 | 428 | (if (cdr (cdr form)) |
4dd1c416 | 429 | (macroexp-progn (byte-optimize-body (cdr form) for-effect)) |
1c393159 JB |
430 | (byte-optimize-form (nth 1 form) for-effect))) |
431 | ((eq fn 'prog1) | |
432 | (if (cdr (cdr form)) | |
433 | (cons 'prog1 | |
434 | (cons (byte-optimize-form (nth 1 form) for-effect) | |
435 | (byte-optimize-body (cdr (cdr form)) t))) | |
436 | (byte-optimize-form (nth 1 form) for-effect))) | |
437 | ((eq fn 'prog2) | |
438 | (cons 'prog2 | |
439 | (cons (byte-optimize-form (nth 1 form) t) | |
440 | (cons (byte-optimize-form (nth 2 form) for-effect) | |
441 | (byte-optimize-body (cdr (cdr (cdr form))) t))))) | |
a1506d29 | 442 | |
2754fefa | 443 | ((memq fn '(save-excursion save-restriction save-current-buffer)) |
1c393159 JB |
444 | ;; those subrs which have an implicit progn; it's not quite good |
445 | ;; enough to treat these like normal function calls. | |
446 | ;; This can turn (save-excursion ...) into (save-excursion) which | |
447 | ;; will be optimized away in the lap-optimize pass. | |
448 | (cons fn (byte-optimize-body (cdr form) for-effect))) | |
a1506d29 | 449 | |
1c393159 JB |
450 | ((eq fn 'with-output-to-temp-buffer) |
451 | ;; this is just like the above, except for the first argument. | |
452 | (cons fn | |
453 | (cons | |
454 | (byte-optimize-form (nth 1 form) nil) | |
455 | (byte-optimize-body (cdr (cdr form)) for-effect)))) | |
a1506d29 | 456 | |
1c393159 | 457 | ((eq fn 'if) |
aefd695a | 458 | (when (< (length form) 3) |
244bbdc5 | 459 | (byte-compile-warn "too few arguments for `if'")) |
1c393159 JB |
460 | (cons fn |
461 | (cons (byte-optimize-form (nth 1 form) nil) | |
462 | (cons | |
463 | (byte-optimize-form (nth 2 form) for-effect) | |
464 | (byte-optimize-body (nthcdr 3 form) for-effect))))) | |
a1506d29 | 465 | |
2ec42da9 SM |
466 | ((memq fn '(and or)) ; Remember, and/or are control structures. |
467 | ;; Take forms off the back until we can't any more. | |
eb8c3be9 | 468 | ;; In the future it could conceivably be a problem that the |
1c393159 JB |
469 | ;; subexpressions of these forms are optimized in the reverse |
470 | ;; order, but it's ok for now. | |
471 | (if for-effect | |
472 | (let ((backwards (reverse (cdr form)))) | |
473 | (while (and backwards | |
474 | (null (setcar backwards | |
475 | (byte-optimize-form (car backwards) | |
476 | for-effect)))) | |
477 | (setq backwards (cdr backwards))) | |
478 | (if (and (cdr form) (null backwards)) | |
479 | (byte-compile-log | |
480 | " all subforms of %s called for effect; deleted" form)) | |
481 | (and backwards | |
2ec42da9 SM |
482 | (cons fn (nreverse (mapcar 'byte-optimize-form |
483 | backwards))))) | |
1c393159 JB |
484 | (cons fn (mapcar 'byte-optimize-form (cdr form))))) |
485 | ||
486 | ((eq fn 'interactive) | |
244bbdc5 | 487 | (byte-compile-warn "misplaced interactive spec: `%s'" |
1c393159 JB |
488 | (prin1-to-string form)) |
489 | nil) | |
a1506d29 | 490 | |
61b108cc | 491 | ((memq fn '(function condition-case)) |
1c393159 JB |
492 | ;; These forms are compiled as constants or by breaking out |
493 | ;; all the subexpressions and compiling them separately. | |
494 | form) | |
495 | ||
496 | ((eq fn 'unwind-protect) | |
497 | ;; the "protected" part of an unwind-protect is compiled (and thus | |
498 | ;; optimized) as a top-level form, so don't do it here. But the | |
499 | ;; non-protected part has the same for-effect status as the | |
500 | ;; unwind-protect itself. (The protected part is always for effect, | |
501 | ;; but that isn't handled properly yet.) | |
502 | (cons fn | |
503 | (cons (byte-optimize-form (nth 1 form) for-effect) | |
504 | (cdr (cdr form))))) | |
a1506d29 | 505 | |
1c393159 JB |
506 | ((eq fn 'catch) |
507 | ;; the body of a catch is compiled (and thus optimized) as a | |
508 | ;; top-level form, so don't do it here. The tag is never | |
509 | ;; for-effect. The body should have the same for-effect status | |
510 | ;; as the catch form itself, but that isn't handled properly yet. | |
511 | (cons fn | |
512 | (cons (byte-optimize-form (nth 1 form) nil) | |
513 | (cdr (cdr form))))) | |
514 | ||
8c26d7b3 RS |
515 | ((eq fn 'ignore) |
516 | ;; Don't treat the args to `ignore' as being | |
517 | ;; computed for effect. We want to avoid the warnings | |
518 | ;; that might occur if they were treated that way. | |
519 | ;; However, don't actually bother calling `ignore'. | |
520 | `(prog1 nil . ,(mapcar 'byte-optimize-form (cdr form)))) | |
521 | ||
09e80d9f | 522 | ;; Needed as long as we run byte-optimize-form after cconv. |
2ec42da9 | 523 | ((eq fn 'internal-make-closure) form) |
29a4dcb0 SM |
524 | |
525 | ((byte-code-function-p fn) | |
526 | (cons fn (mapcar #'byte-optimize-form (cdr form)))) | |
527 | ||
1c393159 | 528 | ((not (symbolp fn)) |
5f11d42c PJ |
529 | (byte-compile-warn "`%s' is a malformed function" |
530 | (prin1-to-string fn)) | |
1c393159 JB |
531 | form) |
532 | ||
533 | ((and for-effect (setq tmp (get fn 'side-effect-free)) | |
534 | (or byte-compile-delete-errors | |
535 | (eq tmp 'error-free) | |
8c26d7b3 RS |
536 | ;; Detect the expansion of (pop foo). |
537 | ;; There is no need to compile the call to `car' there. | |
538 | (and (eq fn 'car) | |
539 | (eq (car-safe (cadr form)) 'prog1) | |
540 | (let ((var (cadr (cadr form))) | |
541 | (last (nth 2 (cadr form)))) | |
542 | (and (symbolp var) | |
543 | (null (nthcdr 3 (cadr form))) | |
544 | (eq (car-safe last) 'setq) | |
545 | (eq (cadr last) var) | |
546 | (eq (car-safe (nth 2 last)) 'cdr) | |
547 | (eq (cadr (nth 2 last)) var)))) | |
1c393159 | 548 | (progn |
1fbb84da CY |
549 | (byte-compile-warn "value returned from %s is unused" |
550 | (prin1-to-string form)) | |
1c393159 JB |
551 | nil))) |
552 | (byte-compile-log " %s called for effect; deleted" fn) | |
553 | ;; appending a nil here might not be necessary, but it can't hurt. | |
554 | (byte-optimize-form | |
555 | (cons 'progn (append (cdr form) '(nil))) t)) | |
a1506d29 | 556 | |
1c393159 JB |
557 | (t |
558 | ;; Otherwise, no args can be considered to be for-effect, | |
559 | ;; even if the called function is for-effect, because we | |
560 | ;; don't know anything about that function. | |
fb67ebdf CY |
561 | (let ((args (mapcar #'byte-optimize-form (cdr form)))) |
562 | (if (and (get fn 'pure) | |
563 | (byte-optimize-all-constp args)) | |
564 | (list 'quote (apply fn (mapcar #'eval args))) | |
565 | (cons fn args))))))) | |
566 | ||
567 | (defun byte-optimize-all-constp (list) | |
4dd1c416 | 568 | "Non-nil if all elements of LIST satisfy `macroexp-const-p" |
fb67ebdf CY |
569 | (let ((constant t)) |
570 | (while (and list constant) | |
4dd1c416 | 571 | (unless (macroexp-const-p (car list)) |
fb67ebdf CY |
572 | (setq constant nil)) |
573 | (setq list (cdr list))) | |
574 | constant)) | |
1c393159 | 575 | |
2ec42da9 | 576 | (defun byte-optimize-form (form &optional for-effect) |
1c393159 JB |
577 | "The source-level pass of the optimizer." |
578 | ;; | |
579 | ;; First, optimize all sub-forms of this one. | |
2ec42da9 | 580 | (setq form (byte-optimize-form-code-walker form for-effect)) |
1c393159 JB |
581 | ;; |
582 | ;; after optimizing all subforms, optimize this form until it doesn't | |
583 | ;; optimize any further. This means that some forms will be passed through | |
584 | ;; the optimizer many times, but that's necessary to make the for-effect | |
585 | ;; processing do as much as possible. | |
586 | ;; | |
2ec42da9 | 587 | (let (opt new) |
1c393159 JB |
588 | (if (and (consp form) |
589 | (symbolp (car form)) | |
7abaf5cc SM |
590 | (or ;; (and for-effect |
591 | ;; ;; We don't have any of these yet, but we might. | |
592 | ;; (setq opt (get (car form) | |
593 | ;; 'byte-for-effect-optimizer))) | |
594 | (setq opt (function-get (car form) 'byte-optimizer))) | |
1c393159 JB |
595 | (not (eq form (setq new (funcall opt form))))) |
596 | (progn | |
597 | ;; (if (equal form new) (error "bogus optimizer -- %s" opt)) | |
598 | (byte-compile-log " %s\t==>\t%s" form new) | |
599 | (setq new (byte-optimize-form new for-effect)) | |
600 | new) | |
601 | form))) | |
602 | ||
603 | ||
604 | (defun byte-optimize-body (forms all-for-effect) | |
2ec42da9 | 605 | ;; Optimize the cdr of a progn or implicit progn; all forms is a list of |
1c393159 JB |
606 | ;; forms, all but the last of which are optimized with the assumption that |
607 | ;; they are being called for effect. the last is for-effect as well if | |
608 | ;; all-for-effect is true. returns a new list of forms. | |
609 | (let ((rest forms) | |
610 | (result nil) | |
611 | fe new) | |
612 | (while rest | |
613 | (setq fe (or all-for-effect (cdr rest))) | |
614 | (setq new (and (car rest) (byte-optimize-form (car rest) fe))) | |
615 | (if (or new (not fe)) | |
616 | (setq result (cons new result))) | |
617 | (setq rest (cdr rest))) | |
618 | (nreverse result))) | |
619 | ||
620 | \f | |
6b61353c KH |
621 | ;; some source-level optimizers |
622 | ;; | |
623 | ;; when writing optimizers, be VERY careful that the optimizer returns | |
624 | ;; something not EQ to its argument if and ONLY if it has made a change. | |
625 | ;; This implies that you cannot simply destructively modify the list; | |
626 | ;; you must return something not EQ to it if you make an optimization. | |
627 | ;; | |
628 | ;; It is now safe to optimize code such that it introduces new bindings. | |
1c393159 | 629 | |
d8947b79 DN |
630 | (defsubst byte-compile-trueconstp (form) |
631 | "Return non-nil if FORM always evaluates to a non-nil value." | |
20ce031c SM |
632 | (while (eq (car-safe form) 'progn) |
633 | (setq form (car (last (cdr form))))) | |
d8947b79 | 634 | (cond ((consp form) |
f58e0fd5 SM |
635 | (pcase (car form) |
636 | (`quote (cadr form)) | |
20ce031c | 637 | ;; Can't use recursion in a defsubst. |
f58e0fd5 | 638 | ;; (`progn (byte-compile-trueconstp (car (last (cdr form))))) |
20ce031c | 639 | )) |
d8947b79 DN |
640 | ((not (symbolp form))) |
641 | ((eq form t)) | |
642 | ((keywordp form)))) | |
643 | ||
644 | (defsubst byte-compile-nilconstp (form) | |
645 | "Return non-nil if FORM always evaluates to a nil value." | |
20ce031c SM |
646 | (while (eq (car-safe form) 'progn) |
647 | (setq form (car (last (cdr form))))) | |
d8947b79 | 648 | (cond ((consp form) |
f58e0fd5 SM |
649 | (pcase (car form) |
650 | (`quote (null (cadr form))) | |
20ce031c | 651 | ;; Can't use recursion in a defsubst. |
f58e0fd5 | 652 | ;; (`progn (byte-compile-nilconstp (car (last (cdr form))))) |
20ce031c | 653 | )) |
d8947b79 DN |
654 | ((not (symbolp form)) nil) |
655 | ((null form)))) | |
1c393159 | 656 | |
70e1dad8 | 657 | ;; If the function is being called with constant numeric args, |
a1506d29 | 658 | ;; evaluate as much as possible at compile-time. This optimizer |
70e1dad8 | 659 | ;; assumes that the function is associative, like + or *. |
1c393159 | 660 | (defun byte-optimize-associative-math (form) |
1c393159 JB |
661 | (let ((args nil) |
662 | (constants nil) | |
663 | (rest (cdr form))) | |
664 | (while rest | |
665 | (if (numberp (car rest)) | |
666 | (setq constants (cons (car rest) constants)) | |
667 | (setq args (cons (car rest) args))) | |
668 | (setq rest (cdr rest))) | |
669 | (if (cdr constants) | |
670 | (if args | |
671 | (list (car form) | |
672 | (apply (car form) constants) | |
673 | (if (cdr args) | |
674 | (cons (car form) (nreverse args)) | |
675 | (car args))) | |
676 | (apply (car form) constants)) | |
677 | form))) | |
678 | ||
70e1dad8 | 679 | ;; If the function is being called with constant numeric args, |
97e6527f KH |
680 | ;; evaluate as much as possible at compile-time. This optimizer |
681 | ;; assumes that the function satisfies | |
682 | ;; (op x1 x2 ... xn) == (op ...(op (op x1 x2) x3) ...xn) | |
683 | ;; like - and /. | |
1c393159 | 684 | (defun byte-optimize-nonassociative-math (form) |
1c393159 JB |
685 | (if (or (not (numberp (car (cdr form)))) |
686 | (not (numberp (car (cdr (cdr form)))))) | |
687 | form | |
688 | (let ((constant (car (cdr form))) | |
689 | (rest (cdr (cdr form)))) | |
690 | (while (numberp (car rest)) | |
691 | (setq constant (funcall (car form) constant (car rest)) | |
692 | rest (cdr rest))) | |
693 | (if rest | |
694 | (cons (car form) (cons constant rest)) | |
695 | constant)))) | |
696 | ||
697 | ;;(defun byte-optimize-associative-two-args-math (form) | |
698 | ;; (setq form (byte-optimize-associative-math form)) | |
699 | ;; (if (consp form) | |
700 | ;; (byte-optimize-two-args-left form) | |
701 | ;; form)) | |
702 | ||
703 | ;;(defun byte-optimize-nonassociative-two-args-math (form) | |
704 | ;; (setq form (byte-optimize-nonassociative-math form)) | |
705 | ;; (if (consp form) | |
706 | ;; (byte-optimize-two-args-right form) | |
707 | ;; form)) | |
708 | ||
97e6527f | 709 | (defun byte-optimize-approx-equal (x y) |
1fa68f21 | 710 | (<= (* (abs (- x y)) 100) (abs (+ x y)))) |
97e6527f KH |
711 | |
712 | ;; Collect all the constants from FORM, after the STARTth arg, | |
713 | ;; and apply FUN to them to make one argument at the end. | |
714 | ;; For functions that can handle floats, that optimization | |
715 | ;; can be incorrect because reordering can cause an overflow | |
716 | ;; that would otherwise be avoided by encountering an arg that is a float. | |
717 | ;; We avoid this problem by (1) not moving float constants and | |
718 | ;; (2) not moving anything if it would cause an overflow. | |
1c393159 JB |
719 | (defun byte-optimize-delay-constants-math (form start fun) |
720 | ;; Merge all FORM's constants from number START, call FUN on them | |
721 | ;; and put the result at the end. | |
97e6527f KH |
722 | (let ((rest (nthcdr (1- start) form)) |
723 | (orig form) | |
724 | ;; t means we must check for overflow. | |
725 | (overflow (memq fun '(+ *)))) | |
1c393159 | 726 | (while (cdr (setq rest (cdr rest))) |
97e6527f | 727 | (if (integerp (car rest)) |
1c393159 JB |
728 | (let (constants) |
729 | (setq form (copy-sequence form) | |
730 | rest (nthcdr (1- start) form)) | |
731 | (while (setq rest (cdr rest)) | |
97e6527f | 732 | (cond ((integerp (car rest)) |
1c393159 JB |
733 | (setq constants (cons (car rest) constants)) |
734 | (setcar rest nil)))) | |
97e6527f KH |
735 | ;; If necessary, check now for overflow |
736 | ;; that might be caused by reordering. | |
737 | (if (and overflow | |
738 | ;; We have overflow if the result of doing the arithmetic | |
739 | ;; on floats is not even close to the result | |
740 | ;; of doing it on integers. | |
741 | (not (byte-optimize-approx-equal | |
742 | (apply fun (mapcar 'float constants)) | |
743 | (float (apply fun constants))))) | |
744 | (setq form orig) | |
745 | (setq form (nconc (delq nil form) | |
746 | (list (apply fun (nreverse constants))))))))) | |
1c393159 JB |
747 | form)) |
748 | ||
cbe5b0eb CY |
749 | (defsubst byte-compile-butlast (form) |
750 | (nreverse (cdr (reverse form)))) | |
751 | ||
1c393159 | 752 | (defun byte-optimize-plus (form) |
cbe5b0eb CY |
753 | ;; Don't call `byte-optimize-delay-constants-math' (bug#1334). |
754 | ;;(setq form (byte-optimize-delay-constants-math form 1 '+)) | |
1c393159 | 755 | (if (memq 0 form) (setq form (delq 0 (copy-sequence form)))) |
cbe5b0eb CY |
756 | ;; For (+ constants...), byte-optimize-predicate does the work. |
757 | (when (memq nil (mapcar 'numberp (cdr form))) | |
758 | (cond | |
759 | ;; (+ x 1) --> (1+ x) and (+ x -1) --> (1- x). | |
760 | ((and (= (length form) 3) | |
761 | (or (memq (nth 1 form) '(1 -1)) | |
762 | (memq (nth 2 form) '(1 -1)))) | |
763 | (let (integer other) | |
764 | (if (memq (nth 1 form) '(1 -1)) | |
765 | (setq integer (nth 1 form) other (nth 2 form)) | |
766 | (setq integer (nth 2 form) other (nth 1 form))) | |
767 | (setq form | |
768 | (list (if (eq integer 1) '1+ '1-) other)))) | |
769 | ;; Here, we could also do | |
770 | ;; (+ x y ... 1) --> (1+ (+ x y ...)) | |
771 | ;; (+ x y ... -1) --> (1- (+ x y ...)) | |
772 | ;; The resulting bytecode is smaller, but is it faster? -- cyd | |
773 | )) | |
774 | (byte-optimize-predicate form)) | |
1c393159 JB |
775 | |
776 | (defun byte-optimize-minus (form) | |
cbe5b0eb CY |
777 | ;; Don't call `byte-optimize-delay-constants-math' (bug#1334). |
778 | ;;(setq form (byte-optimize-delay-constants-math form 2 '+)) | |
779 | ;; Remove zeros. | |
780 | (when (and (nthcdr 3 form) | |
781 | (memq 0 (cddr form))) | |
782 | (setq form (nconc (list (car form) (cadr form)) | |
783 | (delq 0 (copy-sequence (cddr form))))) | |
784 | ;; After the above, we must turn (- x) back into (- x 0) | |
785 | (or (cddr form) | |
786 | (setq form (nconc form (list 0))))) | |
787 | ;; For (- constants..), byte-optimize-predicate does the work. | |
788 | (when (memq nil (mapcar 'numberp (cdr form))) | |
789 | (cond | |
790 | ;; (- x 1) --> (1- x) | |
791 | ((equal (nthcdr 2 form) '(1)) | |
792 | (setq form (list '1- (nth 1 form)))) | |
793 | ;; (- x -1) --> (1+ x) | |
794 | ((equal (nthcdr 2 form) '(-1)) | |
795 | (setq form (list '1+ (nth 1 form)))) | |
796 | ;; (- 0 x) --> (- x) | |
797 | ((and (eq (nth 1 form) 0) | |
798 | (= (length form) 3)) | |
799 | (setq form (list '- (nth 2 form)))) | |
800 | ;; Here, we could also do | |
801 | ;; (- x y ... 1) --> (1- (- x y ...)) | |
802 | ;; (- x y ... -1) --> (1+ (- x y ...)) | |
803 | ;; The resulting bytecode is smaller, but is it faster? -- cyd | |
804 | )) | |
805 | (byte-optimize-predicate form)) | |
1c393159 JB |
806 | |
807 | (defun byte-optimize-multiply (form) | |
808 | (setq form (byte-optimize-delay-constants-math form 1 '*)) | |
cbe5b0eb CY |
809 | ;; For (* constants..), byte-optimize-predicate does the work. |
810 | (when (memq nil (mapcar 'numberp (cdr form))) | |
811 | ;; After `byte-optimize-predicate', if there is a INTEGER constant | |
812 | ;; in FORM, it is in the last element. | |
813 | (let ((last (car (reverse (cdr form))))) | |
814 | (cond | |
815 | ;; Would handling (* ... 0) here cause floating point errors? | |
816 | ;; See bug#1334. | |
817 | ((eq 1 last) (setq form (byte-compile-butlast form))) | |
818 | ((eq -1 last) | |
819 | (setq form (list '- (if (nthcdr 3 form) | |
820 | (byte-compile-butlast form) | |
821 | (nth 1 form)))))))) | |
822 | (byte-optimize-predicate form)) | |
1c393159 JB |
823 | |
824 | (defun byte-optimize-divide (form) | |
825 | (setq form (byte-optimize-delay-constants-math form 2 '*)) | |
cbe5b0eb CY |
826 | ;; After `byte-optimize-predicate', if there is a INTEGER constant |
827 | ;; in FORM, it is in the last element. | |
1c393159 | 828 | (let ((last (car (reverse (cdr (cdr form)))))) |
a1506d29 | 829 | (cond |
cbe5b0eb CY |
830 | ;; Runtime error (leave it intact). |
831 | ((or (null last) | |
832 | (eq last 0) | |
833 | (memql 0.0 (cddr form)))) | |
834 | ;; No constants in expression | |
835 | ((not (numberp last))) | |
836 | ;; For (* constants..), byte-optimize-predicate does the work. | |
837 | ((null (memq nil (mapcar 'numberp (cdr form))))) | |
838 | ;; (/ x y.. 1) --> (/ x y..) | |
839 | ((and (eq last 1) (nthcdr 3 form)) | |
840 | (setq form (byte-compile-butlast form))) | |
841 | ;; (/ x -1), (/ x .. -1) --> (- x), (- (/ x ..)) | |
842 | ((eq last -1) | |
843 | (setq form (list '- (if (nthcdr 3 form) | |
844 | (byte-compile-butlast form) | |
845 | (nth 1 form))))))) | |
846 | (byte-optimize-predicate form)) | |
1c393159 JB |
847 | |
848 | (defun byte-optimize-logmumble (form) | |
849 | (setq form (byte-optimize-delay-constants-math form 1 (car form))) | |
850 | (byte-optimize-predicate | |
851 | (cond ((memq 0 form) | |
852 | (setq form (if (eq (car form) 'logand) | |
853 | (cons 'progn (cdr form)) | |
854 | (delq 0 (copy-sequence form))))) | |
855 | ((and (eq (car-safe form) 'logior) | |
856 | (memq -1 form)) | |
97e6527f | 857 | (cons 'progn (cdr form))) |
1c393159 JB |
858 | (form)))) |
859 | ||
860 | ||
861 | (defun byte-optimize-binary-predicate (form) | |
4dd1c416 SM |
862 | (if (macroexp-const-p (nth 1 form)) |
863 | (if (macroexp-const-p (nth 2 form)) | |
1c393159 JB |
864 | (condition-case () |
865 | (list 'quote (eval form)) | |
866 | (error form)) | |
867 | ;; This can enable some lapcode optimizations. | |
868 | (list (car form) (nth 2 form) (nth 1 form))) | |
869 | form)) | |
870 | ||
871 | (defun byte-optimize-predicate (form) | |
872 | (let ((ok t) | |
873 | (rest (cdr form))) | |
874 | (while (and rest ok) | |
4dd1c416 | 875 | (setq ok (macroexp-const-p (car rest)) |
1c393159 JB |
876 | rest (cdr rest))) |
877 | (if ok | |
878 | (condition-case () | |
879 | (list 'quote (eval form)) | |
880 | (error form)) | |
881 | form))) | |
882 | ||
883 | (defun byte-optimize-identity (form) | |
884 | (if (and (cdr form) (null (cdr (cdr form)))) | |
885 | (nth 1 form) | |
244bbdc5 | 886 | (byte-compile-warn "identity called with %d arg%s, but requires 1" |
1c393159 JB |
887 | (length (cdr form)) |
888 | (if (= 1 (length (cdr form))) "" "s")) | |
889 | form)) | |
890 | ||
891 | (put 'identity 'byte-optimizer 'byte-optimize-identity) | |
892 | ||
893 | (put '+ 'byte-optimizer 'byte-optimize-plus) | |
894 | (put '* 'byte-optimizer 'byte-optimize-multiply) | |
895 | (put '- 'byte-optimizer 'byte-optimize-minus) | |
896 | (put '/ 'byte-optimizer 'byte-optimize-divide) | |
897 | (put 'max 'byte-optimizer 'byte-optimize-associative-math) | |
898 | (put 'min 'byte-optimizer 'byte-optimize-associative-math) | |
899 | ||
900 | (put '= 'byte-optimizer 'byte-optimize-binary-predicate) | |
901 | (put 'eq 'byte-optimizer 'byte-optimize-binary-predicate) | |
1c393159 JB |
902 | (put 'equal 'byte-optimizer 'byte-optimize-binary-predicate) |
903 | (put 'string= 'byte-optimizer 'byte-optimize-binary-predicate) | |
904 | (put 'string-equal 'byte-optimizer 'byte-optimize-binary-predicate) | |
905 | ||
906 | (put '< 'byte-optimizer 'byte-optimize-predicate) | |
907 | (put '> 'byte-optimizer 'byte-optimize-predicate) | |
908 | (put '<= 'byte-optimizer 'byte-optimize-predicate) | |
909 | (put '>= 'byte-optimizer 'byte-optimize-predicate) | |
910 | (put '1+ 'byte-optimizer 'byte-optimize-predicate) | |
911 | (put '1- 'byte-optimizer 'byte-optimize-predicate) | |
912 | (put 'not 'byte-optimizer 'byte-optimize-predicate) | |
913 | (put 'null 'byte-optimizer 'byte-optimize-predicate) | |
914 | (put 'memq 'byte-optimizer 'byte-optimize-predicate) | |
915 | (put 'consp 'byte-optimizer 'byte-optimize-predicate) | |
916 | (put 'listp 'byte-optimizer 'byte-optimize-predicate) | |
917 | (put 'symbolp 'byte-optimizer 'byte-optimize-predicate) | |
918 | (put 'stringp 'byte-optimizer 'byte-optimize-predicate) | |
919 | (put 'string< 'byte-optimizer 'byte-optimize-predicate) | |
920 | (put 'string-lessp 'byte-optimizer 'byte-optimize-predicate) | |
921 | ||
922 | (put 'logand 'byte-optimizer 'byte-optimize-logmumble) | |
923 | (put 'logior 'byte-optimizer 'byte-optimize-logmumble) | |
924 | (put 'logxor 'byte-optimizer 'byte-optimize-logmumble) | |
925 | (put 'lognot 'byte-optimizer 'byte-optimize-predicate) | |
926 | ||
927 | (put 'car 'byte-optimizer 'byte-optimize-predicate) | |
928 | (put 'cdr 'byte-optimizer 'byte-optimize-predicate) | |
929 | (put 'car-safe 'byte-optimizer 'byte-optimize-predicate) | |
930 | (put 'cdr-safe 'byte-optimizer 'byte-optimize-predicate) | |
931 | ||
932 | ||
a1506d29 | 933 | ;; I'm not convinced that this is necessary. Doesn't the optimizer loop |
1c393159 JB |
934 | ;; take care of this? - Jamie |
935 | ;; I think this may some times be necessary to reduce ie (quote 5) to 5, | |
eb8c3be9 | 936 | ;; so arithmetic optimizers recognize the numeric constant. - Hallvard |
1c393159 JB |
937 | (put 'quote 'byte-optimizer 'byte-optimize-quote) |
938 | (defun byte-optimize-quote (form) | |
939 | (if (or (consp (nth 1 form)) | |
940 | (and (symbolp (nth 1 form)) | |
4dd1c416 | 941 | (not (macroexp--const-symbol-p form)))) |
1c393159 JB |
942 | form |
943 | (nth 1 form))) | |
944 | ||
945 | (defun byte-optimize-zerop (form) | |
946 | (cond ((numberp (nth 1 form)) | |
947 | (eval form)) | |
948 | (byte-compile-delete-errors | |
949 | (list '= (nth 1 form) 0)) | |
950 | (form))) | |
951 | ||
952 | (put 'zerop 'byte-optimizer 'byte-optimize-zerop) | |
953 | ||
954 | (defun byte-optimize-and (form) | |
955 | ;; Simplify if less than 2 args. | |
956 | ;; if there is a literal nil in the args to `and', throw it and following | |
957 | ;; forms away, and surround the `and' with (progn ... nil). | |
958 | (cond ((null (cdr form))) | |
959 | ((memq nil form) | |
960 | (list 'progn | |
961 | (byte-optimize-and | |
962 | (prog1 (setq form (copy-sequence form)) | |
963 | (while (nth 1 form) | |
964 | (setq form (cdr form))) | |
965 | (setcdr form nil))) | |
966 | nil)) | |
967 | ((null (cdr (cdr form))) | |
968 | (nth 1 form)) | |
969 | ((byte-optimize-predicate form)))) | |
970 | ||
971 | (defun byte-optimize-or (form) | |
972 | ;; Throw away nil's, and simplify if less than 2 args. | |
973 | ;; If there is a literal non-nil constant in the args to `or', throw away all | |
974 | ;; following forms. | |
975 | (if (memq nil form) | |
976 | (setq form (delq nil (copy-sequence form)))) | |
977 | (let ((rest form)) | |
978 | (while (cdr (setq rest (cdr rest))) | |
979 | (if (byte-compile-trueconstp (car rest)) | |
980 | (setq form (copy-sequence form) | |
981 | rest (setcdr (memq (car rest) form) nil)))) | |
982 | (if (cdr (cdr form)) | |
983 | (byte-optimize-predicate form) | |
984 | (nth 1 form)))) | |
985 | ||
986 | (defun byte-optimize-cond (form) | |
987 | ;; if any clauses have a literal nil as their test, throw them away. | |
988 | ;; if any clause has a literal non-nil constant as its test, throw | |
989 | ;; away all following clauses. | |
990 | (let (rest) | |
991 | ;; This must be first, to reduce (cond (t ...) (nil)) to (progn t ...) | |
992 | (while (setq rest (assq nil (cdr form))) | |
993 | (setq form (delq rest (copy-sequence form)))) | |
994 | (if (memq nil (cdr form)) | |
995 | (setq form (delq nil (copy-sequence form)))) | |
996 | (setq rest form) | |
997 | (while (setq rest (cdr rest)) | |
998 | (cond ((byte-compile-trueconstp (car-safe (car rest))) | |
d8947b79 DN |
999 | ;; This branch will always be taken: kill the subsequent ones. |
1000 | (cond ((eq rest (cdr form)) ;First branch of `cond'. | |
1001 | (setq form `(progn ,@(car rest)))) | |
1c393159 JB |
1002 | ((cdr rest) |
1003 | (setq form (copy-sequence form)) | |
1004 | (setcdr (memq (car rest) form) nil))) | |
d8947b79 DN |
1005 | (setq rest nil)) |
1006 | ((and (consp (car rest)) | |
1007 | (byte-compile-nilconstp (caar rest))) | |
1008 | ;; This branch will never be taken: kill its body. | |
1009 | (setcdr (car rest) nil))))) | |
1c393159 JB |
1010 | ;; |
1011 | ;; Turn (cond (( <x> )) ... ) into (or <x> (cond ... )) | |
1012 | (if (eq 'cond (car-safe form)) | |
1013 | (let ((clauses (cdr form))) | |
1014 | (if (and (consp (car clauses)) | |
1015 | (null (cdr (car clauses)))) | |
1016 | (list 'or (car (car clauses)) | |
1017 | (byte-optimize-cond | |
1018 | (cons (car form) (cdr (cdr form))))) | |
1019 | form)) | |
1020 | form)) | |
1021 | ||
1022 | (defun byte-optimize-if (form) | |
40fafc21 | 1023 | ;; (if (progn <insts> <test>) <rest>) ==> (progn <insts> (if <test> <rest>)) |
1c393159 JB |
1024 | ;; (if <true-constant> <then> <else...>) ==> <then> |
1025 | ;; (if <false-constant> <then> <else...>) ==> (progn <else...>) | |
1026 | ;; (if <test> nil <else...>) ==> (if (not <test>) (progn <else...>)) | |
1027 | ;; (if <test> <then> nil) ==> (if <test> <then>) | |
1028 | (let ((clause (nth 1 form))) | |
9d693d80 SM |
1029 | (cond ((and (eq (car-safe clause) 'progn) |
1030 | ;; `clause' is a proper list. | |
1031 | (null (cdr (last clause)))) | |
40fafc21 SM |
1032 | (if (null (cddr clause)) |
1033 | ;; A trivial `progn'. | |
1034 | (byte-optimize-if `(if ,(cadr clause) ,@(nthcdr 2 form))) | |
1035 | (nconc (butlast clause) | |
1036 | (list | |
1037 | (byte-optimize-if | |
1038 | `(if ,(car (last clause)) ,@(nthcdr 2 form))))))) | |
1039 | ((byte-compile-trueconstp clause) | |
d8947b79 DN |
1040 | `(progn ,clause ,(nth 2 form))) |
1041 | ((byte-compile-nilconstp clause) | |
1042 | `(progn ,clause ,@(nthcdr 3 form))) | |
1c393159 JB |
1043 | ((nth 2 form) |
1044 | (if (equal '(nil) (nthcdr 3 form)) | |
1045 | (list 'if clause (nth 2 form)) | |
1046 | form)) | |
1047 | ((or (nth 3 form) (nthcdr 4 form)) | |
97e6527f KH |
1048 | (list 'if |
1049 | ;; Don't make a double negative; | |
1050 | ;; instead, take away the one that is there. | |
1051 | (if (and (consp clause) (memq (car clause) '(not null)) | |
1052 | (= (length clause) 2)) ; (not xxxx) or (not (xxxx)) | |
1053 | (nth 1 clause) | |
1054 | (list 'not clause)) | |
1c393159 JB |
1055 | (if (nthcdr 4 form) |
1056 | (cons 'progn (nthcdr 3 form)) | |
1057 | (nth 3 form)))) | |
1058 | (t | |
1059 | (list 'progn clause nil))))) | |
1060 | ||
1061 | (defun byte-optimize-while (form) | |
aefd695a | 1062 | (when (< (length form) 2) |
244bbdc5 | 1063 | (byte-compile-warn "too few arguments for `while'")) |
1c393159 JB |
1064 | (if (nth 1 form) |
1065 | form)) | |
1066 | ||
1067 | (put 'and 'byte-optimizer 'byte-optimize-and) | |
1068 | (put 'or 'byte-optimizer 'byte-optimize-or) | |
1069 | (put 'cond 'byte-optimizer 'byte-optimize-cond) | |
1070 | (put 'if 'byte-optimizer 'byte-optimize-if) | |
1071 | (put 'while 'byte-optimizer 'byte-optimize-while) | |
1072 | ||
1073 | ;; byte-compile-negation-optimizer lives in bytecomp.el | |
1074 | (put '/= 'byte-optimizer 'byte-compile-negation-optimizer) | |
1075 | (put 'atom 'byte-optimizer 'byte-compile-negation-optimizer) | |
1076 | (put 'nlistp 'byte-optimizer 'byte-compile-negation-optimizer) | |
1077 | ||
1078 | ||
1079 | (defun byte-optimize-funcall (form) | |
72d8b544 SM |
1080 | ;; (funcall (lambda ...) ...) ==> ((lambda ...) ...) |
1081 | ;; (funcall foo ...) ==> (foo ...) | |
1c393159 JB |
1082 | (let ((fn (nth 1 form))) |
1083 | (if (memq (car-safe fn) '(quote function)) | |
1084 | (cons (nth 1 fn) (cdr (cdr form))) | |
ca105506 | 1085 | form))) |
1c393159 JB |
1086 | |
1087 | (defun byte-optimize-apply (form) | |
1088 | ;; If the last arg is a literal constant, turn this into a funcall. | |
1089 | ;; The funcall optimizer can then transform (funcall 'foo ...) -> (foo ...). | |
1090 | (let ((fn (nth 1 form)) | |
1091 | (last (nth (1- (length form)) form))) ; I think this really is fastest | |
1092 | (or (if (or (null last) | |
1093 | (eq (car-safe last) 'quote)) | |
1094 | (if (listp (nth 1 last)) | |
1095 | (let ((butlast (nreverse (cdr (reverse (cdr (cdr form))))))) | |
7e1dae73 | 1096 | (nconc (list 'funcall fn) butlast |
72d8b544 | 1097 | (mapcar (lambda (x) (list 'quote x)) (nth 1 last)))) |
1c393159 | 1098 | (byte-compile-warn |
244bbdc5 | 1099 | "last arg to apply can't be a literal atom: `%s'" |
1c393159 JB |
1100 | (prin1-to-string last)) |
1101 | nil)) | |
1102 | form))) | |
1103 | ||
1104 | (put 'funcall 'byte-optimizer 'byte-optimize-funcall) | |
1105 | (put 'apply 'byte-optimizer 'byte-optimize-apply) | |
1106 | ||
1107 | ||
1108 | (put 'let 'byte-optimizer 'byte-optimize-letX) | |
1109 | (put 'let* 'byte-optimizer 'byte-optimize-letX) | |
1110 | (defun byte-optimize-letX (form) | |
1111 | (cond ((null (nth 1 form)) | |
1112 | ;; No bindings | |
1113 | (cons 'progn (cdr (cdr form)))) | |
1114 | ((or (nth 2 form) (nthcdr 3 form)) | |
1115 | form) | |
1116 | ;; The body is nil | |
1117 | ((eq (car form) 'let) | |
5d265171 RS |
1118 | (append '(progn) (mapcar 'car-safe (mapcar 'cdr-safe (nth 1 form))) |
1119 | '(nil))) | |
1c393159 JB |
1120 | (t |
1121 | (let ((binds (reverse (nth 1 form)))) | |
1122 | (list 'let* (reverse (cdr binds)) (nth 1 (car binds)) nil))))) | |
1123 | ||
1124 | ||
1125 | (put 'nth 'byte-optimizer 'byte-optimize-nth) | |
1126 | (defun byte-optimize-nth (form) | |
56cfa244 DL |
1127 | (if (= (safe-length form) 3) |
1128 | (if (memq (nth 1 form) '(0 1)) | |
1129 | (list 'car (if (zerop (nth 1 form)) | |
1130 | (nth 2 form) | |
1131 | (list 'cdr (nth 2 form)))) | |
1132 | (byte-optimize-predicate form)) | |
1133 | form)) | |
1c393159 JB |
1134 | |
1135 | (put 'nthcdr 'byte-optimizer 'byte-optimize-nthcdr) | |
1136 | (defun byte-optimize-nthcdr (form) | |
56cfa244 DL |
1137 | (if (= (safe-length form) 3) |
1138 | (if (memq (nth 1 form) '(0 1 2)) | |
1139 | (let ((count (nth 1 form))) | |
1140 | (setq form (nth 2 form)) | |
1141 | (while (>= (setq count (1- count)) 0) | |
1142 | (setq form (list 'cdr form))) | |
1143 | form) | |
1144 | (byte-optimize-predicate form)) | |
1145 | form)) | |
79d137ff | 1146 | |
e5c230f4 DL |
1147 | ;; Fixme: delete-char -> delete-region (byte-coded) |
1148 | ;; optimize string-as-unibyte, string-as-multibyte, string-make-unibyte, | |
1149 | ;; string-make-multibyte for constant args. | |
1150 | ||
66ff2893 SM |
1151 | (put 'set 'byte-optimizer 'byte-optimize-set) |
1152 | (defun byte-optimize-set (form) | |
1153 | (let ((var (car-safe (cdr-safe form)))) | |
1154 | (cond | |
1155 | ((and (eq (car-safe var) 'quote) (consp (cdr var))) | |
e64e9e6a | 1156 | `(setq ,(cadr var) ,@(cddr form))) |
66ff2893 SM |
1157 | ((and (eq (car-safe var) 'make-local-variable) |
1158 | (eq (car-safe (setq var (car-safe (cdr var)))) 'quote) | |
1159 | (consp (cdr var))) | |
1160 | `(progn ,(cadr form) (setq ,(cadr var) ,@(cddr form)))) | |
1161 | (t form)))) | |
1c393159 | 1162 | \f |
6b61353c KH |
1163 | ;; enumerating those functions which need not be called if the returned |
1164 | ;; value is not used. That is, something like | |
1165 | ;; (progn (list (something-with-side-effects) (yow)) | |
1166 | ;; (foo)) | |
1167 | ;; may safely be turned into | |
1168 | ;; (progn (progn (something-with-side-effects) (yow)) | |
1169 | ;; (foo)) | |
1170 | ;; Further optimizations will turn (progn (list 1 2 3) 'foo) into 'foo. | |
1171 | ||
1172 | ;; Some of these functions have the side effect of allocating memory | |
1173 | ;; and it would be incorrect to replace two calls with one. | |
1174 | ;; But we don't try to do those kinds of optimizations, | |
1175 | ;; so it is safe to list such functions here. | |
1176 | ;; Some of these functions return values that depend on environment | |
1177 | ;; state, so that constant folding them would be wrong, | |
1178 | ;; but we don't do constant folding based on this list. | |
1179 | ||
1180 | ;; However, at present the only optimization we normally do | |
1181 | ;; is delete calls that need not occur, and we only do that | |
1182 | ;; with the error-free functions. | |
1183 | ||
1184 | ;; I wonder if I missed any :-\) | |
1c393159 | 1185 | (let ((side-effect-free-fns |
c20a77cc RS |
1186 | '(% * + - / /= 1+ 1- < <= = > >= abs acos append aref ash asin atan |
1187 | assoc assq | |
1188 | boundp buffer-file-name buffer-local-variables buffer-modified-p | |
1fc9ee97 | 1189 | buffer-substring byte-code-function-p |
049a65a3 | 1190 | capitalize car-less-than-car car cdr ceiling char-after char-before |
8e6a67b7 DA |
1191 | char-equal char-to-string char-width compare-strings |
1192 | compare-window-configurations concat coordinates-in-window-p | |
1fc9ee97 | 1193 | copy-alist copy-sequence copy-marker cos count-lines |
9e60aa0b | 1194 | decode-char |
1fc9ee97 | 1195 | decode-time default-boundp default-value documentation downcase |
8f924df7 | 1196 | elt encode-char exp expt encode-time error-message-string |
1fc9ee97 | 1197 | fboundp fceiling featurep ffloor |
1c393159 JB |
1198 | file-directory-p file-exists-p file-locked-p file-name-absolute-p |
1199 | file-newer-than-file-p file-readable-p file-symlink-p file-writable-p | |
8e6a67b7 DA |
1200 | float float-time floor format format-time-string frame-first-window |
1201 | frame-root-window frame-selected-window | |
1202 | frame-visible-p fround ftruncate | |
2412aadb DL |
1203 | get gethash get-buffer get-buffer-window getenv get-file-buffer |
1204 | hash-table-count | |
1fc9ee97 | 1205 | int-to-string intern-soft |
f34bba69 | 1206 | keymap-parent |
e1f0df62 | 1207 | length local-variable-if-set-p local-variable-p log log10 logand |
f9cbd456 | 1208 | logb logior lognot logxor lsh langinfo |
8e6a67b7 DA |
1209 | make-list make-string make-symbol marker-buffer max member memq min |
1210 | minibuffer-selected-window minibuffer-window | |
1211 | mod multibyte-char-to-unibyte next-window nth nthcdr number-to-string | |
1fc9ee97 RS |
1212 | parse-colon-path plist-get plist-member |
1213 | prefix-numeric-value previous-window prin1-to-string propertize | |
ba661bf0 | 1214 | degrees-to-radians |
1fc9ee97 RS |
1215 | radians-to-degrees rassq rassoc read-from-string regexp-quote |
1216 | region-beginning region-end reverse round | |
049a65a3 | 1217 | sin sqrt string string< string= string-equal string-lessp string-to-char |
1fc9ee97 | 1218 | string-to-int string-to-number substring sxhash symbol-function |
d9881cf1 DL |
1219 | symbol-name symbol-plist symbol-value string-make-unibyte |
1220 | string-make-multibyte string-as-multibyte string-as-unibyte | |
8f924df7 | 1221 | string-to-multibyte |
1fc9ee97 RS |
1222 | tan truncate |
1223 | unibyte-char-to-multibyte upcase user-full-name | |
b4d3bc10 | 1224 | user-login-name user-original-login-name custom-variable-p |
1fc9ee97 | 1225 | vconcat |
8e6a67b7 DA |
1226 | window-absolute-pixel-edges window-at window-body-height |
1227 | window-body-width window-buffer window-dedicated-p window-display-table | |
1228 | window-combination-limit window-edges window-frame window-fringes | |
1229 | window-height window-hscroll window-inside-edges | |
1230 | window-inside-absolute-pixel-edges window-inside-pixel-edges | |
1231 | window-left-child window-left-column window-margins window-minibuffer-p | |
1232 | window-next-buffers window-next-sibling window-new-normal | |
1233 | window-new-total window-normal-size window-parameter window-parameters | |
1234 | window-parent window-pixel-edges window-point window-prev-buffers | |
1235 | window-prev-sibling window-redisplay-end-trigger window-scroll-bars | |
1236 | window-start window-text-height window-top-child window-top-line | |
1237 | window-total-height window-total-width window-use-time window-vscroll | |
1238 | window-width zerop)) | |
1c393159 | 1239 | (side-effect-and-error-free-fns |
c20a77cc | 1240 | '(arrayp atom |
a1506d29 | 1241 | bobp bolp bool-vector-p |
1fc9ee97 | 1242 | buffer-end buffer-list buffer-size buffer-string bufferp |
354a6a95 | 1243 | car-safe case-table-p cdr-safe char-or-string-p characterp |
85eb6576 | 1244 | charsetp commandp cons consp |
f34bba69 | 1245 | current-buffer current-global-map current-indentation |
1fc9ee97 RS |
1246 | current-local-map current-minor-mode-maps current-time |
1247 | current-time-string current-time-zone | |
1248 | eobp eolp eq equal eventp | |
049a65a3 | 1249 | floatp following-char framep |
c20a77cc | 1250 | get-largest-window get-lru-window |
2412aadb | 1251 | hash-table-p |
c20a77cc RS |
1252 | identity ignore integerp integer-or-marker-p interactive-p |
1253 | invocation-directory invocation-name | |
f34bba69 DL |
1254 | keymapp |
1255 | line-beginning-position line-end-position list listp | |
8f924df7 KH |
1256 | make-marker mark mark-marker markerp max-char |
1257 | memory-limit minibuffer-window | |
c20a77cc RS |
1258 | mouse-movement-p |
1259 | natnump nlistp not null number-or-marker-p numberp | |
1260 | one-window-p overlayp | |
85eb6576 DL |
1261 | point point-marker point-min point-max preceding-char primary-charset |
1262 | processp | |
f34bba69 | 1263 | recent-keys recursion-depth |
1fc9ee97 RS |
1264 | safe-length selected-frame selected-window sequencep |
1265 | standard-case-table standard-syntax-table stringp subrp symbolp | |
1266 | syntax-table syntax-table-p | |
f34bba69 DL |
1267 | this-command-keys this-command-keys-vector this-single-command-keys |
1268 | this-single-command-raw-keys | |
c20a77cc | 1269 | user-real-login-name user-real-uid user-uid |
f34bba69 | 1270 | vector vectorp visible-frame-list |
8e6a67b7 DA |
1271 | wholenump window-configuration-p window-live-p |
1272 | window-valid-p windowp))) | |
1c393159 JB |
1273 | (while side-effect-free-fns |
1274 | (put (car side-effect-free-fns) 'side-effect-free t) | |
1275 | (setq side-effect-free-fns (cdr side-effect-free-fns))) | |
1276 | (while side-effect-and-error-free-fns | |
1277 | (put (car side-effect-and-error-free-fns) 'side-effect-free 'error-free) | |
1278 | (setq side-effect-and-error-free-fns (cdr side-effect-and-error-free-fns))) | |
1279 | nil) | |
1280 | ||
fb67ebdf CY |
1281 | \f |
1282 | ;; pure functions are side-effect free functions whose values depend | |
1283 | ;; only on their arguments. For these functions, calls with constant | |
1284 | ;; arguments can be evaluated at compile time. This may shift run time | |
1285 | ;; errors to compile time. | |
1286 | ||
1287 | (let ((pure-fns | |
1288 | '(concat symbol-name regexp-opt regexp-quote string-to-syntax))) | |
1289 | (while pure-fns | |
1290 | (put (car pure-fns) 'pure t) | |
1291 | (setq pure-fns (cdr pure-fns))) | |
1292 | nil) | |
1c393159 JB |
1293 | \f |
1294 | (defconst byte-constref-ops | |
1295 | '(byte-constant byte-constant2 byte-varref byte-varset byte-varbind)) | |
1296 | ||
f619ad4c SM |
1297 | ;; Used and set dynamically in byte-decompile-bytecode-1. |
1298 | (defvar bytedecomp-op) | |
1299 | (defvar bytedecomp-ptr) | |
f619ad4c | 1300 | |
6b61353c KH |
1301 | ;; This function extracts the bitfields from variable-length opcodes. |
1302 | ;; Originally defined in disass.el (which no longer uses it.) | |
ca105506 | 1303 | (defun disassemble-offset (bytes) |
1c393159 | 1304 | "Don't call this!" |
ca105506 SM |
1305 | ;; Fetch and return the offset for the current opcode. |
1306 | ;; Return nil if this opcode has no offset. | |
17fc58c9 GM |
1307 | (cond ((< bytedecomp-op byte-nth) |
1308 | (let ((tem (logand bytedecomp-op 7))) | |
1309 | (setq bytedecomp-op (logand bytedecomp-op 248)) | |
1c393159 | 1310 | (cond ((eq tem 6) |
17fc58c9 GM |
1311 | ;; Offset in next byte. |
1312 | (setq bytedecomp-ptr (1+ bytedecomp-ptr)) | |
ca105506 | 1313 | (aref bytes bytedecomp-ptr)) |
1c393159 | 1314 | ((eq tem 7) |
17fc58c9 GM |
1315 | ;; Offset in next 2 bytes. |
1316 | (setq bytedecomp-ptr (1+ bytedecomp-ptr)) | |
ca105506 | 1317 | (+ (aref bytes bytedecomp-ptr) |
17fc58c9 | 1318 | (progn (setq bytedecomp-ptr (1+ bytedecomp-ptr)) |
ca105506 SM |
1319 | (lsh (aref bytes bytedecomp-ptr) 8)))) |
1320 | (t tem)))) ;Offset was in opcode. | |
17fc58c9 | 1321 | ((>= bytedecomp-op byte-constant) |
ca105506 | 1322 | (prog1 (- bytedecomp-op byte-constant) ;Offset in opcode. |
17fc58c9 | 1323 | (setq bytedecomp-op byte-constant))) |
2c302df3 SM |
1324 | ((or (and (>= bytedecomp-op byte-constant2) |
1325 | (<= bytedecomp-op byte-goto-if-not-nil-else-pop)) | |
1326 | (= bytedecomp-op byte-stack-set2)) | |
17fc58c9 GM |
1327 | ;; Offset in next 2 bytes. |
1328 | (setq bytedecomp-ptr (1+ bytedecomp-ptr)) | |
ca105506 | 1329 | (+ (aref bytes bytedecomp-ptr) |
17fc58c9 | 1330 | (progn (setq bytedecomp-ptr (1+ bytedecomp-ptr)) |
ca105506 | 1331 | (lsh (aref bytes bytedecomp-ptr) 8)))) |
17fc58c9 | 1332 | ((and (>= bytedecomp-op byte-listN) |
2c302df3 | 1333 | (<= bytedecomp-op byte-discardN)) |
ca105506 SM |
1334 | (setq bytedecomp-ptr (1+ bytedecomp-ptr)) ;Offset in next byte. |
1335 | (aref bytes bytedecomp-ptr)))) | |
1c393159 | 1336 | |
bba752f8 | 1337 | (defvar byte-compile-tag-number) |
1c393159 | 1338 | |
6b61353c KH |
1339 | ;; This de-compiler is used for inline expansion of compiled functions, |
1340 | ;; and by the disassembler. | |
1341 | ;; | |
1342 | ;; This list contains numbers, which are pc values, | |
1343 | ;; before each instruction. | |
1c393159 | 1344 | (defun byte-decompile-bytecode (bytes constvec) |
40fafc21 | 1345 | "Turn BYTECODE into lapcode, referring to CONSTVEC." |
1c393159 JB |
1346 | (let ((byte-compile-constants nil) |
1347 | (byte-compile-variables nil) | |
1348 | (byte-compile-tag-number 0)) | |
1349 | (byte-decompile-bytecode-1 bytes constvec))) | |
1350 | ||
70e1dad8 RS |
1351 | ;; As byte-decompile-bytecode, but updates |
1352 | ;; byte-compile-{constants, variables, tag-number}. | |
cffcfe66 | 1353 | ;; If MAKE-SPLICEABLE is true, then `return' opcodes are replaced |
70e1dad8 | 1354 | ;; with `goto's destined for the end of the code. |
cffcfe66 RS |
1355 | ;; That is for use by the compiler. |
1356 | ;; If MAKE-SPLICEABLE is nil, we are being called for the disassembler. | |
1357 | ;; In that case, we put a pc value into the list | |
1358 | ;; before each insn (or its label). | |
bba752f8 | 1359 | (defun byte-decompile-bytecode-1 (bytes constvec &optional make-spliceable) |
29a4dcb0 | 1360 | (let ((length (length bytes)) |
ca105506 | 1361 | (bytedecomp-ptr 0) optr tags bytedecomp-op offset |
332e62ab | 1362 | lap tmp) |
17fc58c9 | 1363 | (while (not (= bytedecomp-ptr length)) |
cffcfe66 | 1364 | (or make-spliceable |
ca105506 | 1365 | (push bytedecomp-ptr lap)) |
29a4dcb0 | 1366 | (setq bytedecomp-op (aref bytes bytedecomp-ptr) |
17fc58c9 | 1367 | optr bytedecomp-ptr |
ca105506 | 1368 | ;; This uses dynamic-scope magic. |
29a4dcb0 | 1369 | offset (disassemble-offset bytes)) |
332e62ab | 1370 | (let ((opcode (aref byte-code-vector bytedecomp-op))) |
f80efb86 | 1371 | (cl-assert opcode) |
332e62ab | 1372 | (setq bytedecomp-op opcode)) |
17fc58c9 | 1373 | (cond ((memq bytedecomp-op byte-goto-ops) |
ca105506 | 1374 | ;; It's a pc. |
1c393159 JB |
1375 | (setq offset |
1376 | (cdr (or (assq offset tags) | |
ca105506 SM |
1377 | (let ((new (cons offset (byte-compile-make-tag)))) |
1378 | (push new tags) | |
1379 | new))))) | |
17fc58c9 GM |
1380 | ((cond ((eq bytedecomp-op 'byte-constant2) |
1381 | (setq bytedecomp-op 'byte-constant) t) | |
1382 | ((memq bytedecomp-op byte-constref-ops))) | |
6ebe9f82 RS |
1383 | (setq tmp (if (>= offset (length constvec)) |
1384 | (list 'out-of-range offset) | |
1385 | (aref constvec offset)) | |
17fc58c9 | 1386 | offset (if (eq bytedecomp-op 'byte-constant) |
1c393159 JB |
1387 | (byte-compile-get-constant tmp) |
1388 | (or (assq tmp byte-compile-variables) | |
ca105506 SM |
1389 | (let ((new (list tmp))) |
1390 | (push new byte-compile-variables) | |
1391 | new))))) | |
2c302df3 SM |
1392 | ((eq bytedecomp-op 'byte-stack-set2) |
1393 | (setq bytedecomp-op 'byte-stack-set)) | |
1394 | ((and (eq bytedecomp-op 'byte-discardN) (>= offset #x80)) | |
b9598260 SM |
1395 | ;; The top bit of the operand for byte-discardN is a flag, |
1396 | ;; saying whether the top-of-stack is preserved. In | |
1397 | ;; lapcode, we represent this by using a different opcode | |
1398 | ;; (with the flag removed from the operand). | |
2c302df3 | 1399 | (setq bytedecomp-op 'byte-discardN-preserve-tos) |
b9598260 | 1400 | (setq offset (- offset #x80)))) |
1c393159 | 1401 | ;; lap = ( [ (pc . (op . arg)) ]* ) |
ca105506 SM |
1402 | (push (cons optr (cons bytedecomp-op (or offset 0))) |
1403 | lap) | |
17fc58c9 | 1404 | (setq bytedecomp-ptr (1+ bytedecomp-ptr))) |
1c393159 JB |
1405 | (let ((rest lap)) |
1406 | (while rest | |
41cf13b9 RS |
1407 | (cond ((numberp (car rest))) |
1408 | ((setq tmp (assq (car (car rest)) tags)) | |
ca105506 | 1409 | ;; This addr is jumped to. |
1c393159 JB |
1410 | (setcdr rest (cons (cons nil (cdr tmp)) |
1411 | (cdr rest))) | |
1412 | (setq tags (delq tmp tags)) | |
1413 | (setq rest (cdr rest)))) | |
1414 | (setq rest (cdr rest)))) | |
1415 | (if tags (error "optimizer error: missed tags %s" tags)) | |
ca105506 | 1416 | ;; Remove addrs, lap = ( [ (op . arg) | (TAG tagno) ]* ) |
41cf13b9 RS |
1417 | (mapcar (function (lambda (elt) |
1418 | (if (numberp elt) | |
1419 | elt | |
1420 | (cdr elt)))) | |
1421 | (nreverse lap)))) | |
1c393159 JB |
1422 | |
1423 | \f | |
1424 | ;;; peephole optimizer | |
1425 | ||
1426 | (defconst byte-tagref-ops (cons 'TAG byte-goto-ops)) | |
1427 | ||
1428 | (defconst byte-conditional-ops | |
1429 | '(byte-goto-if-nil byte-goto-if-not-nil byte-goto-if-nil-else-pop | |
1430 | byte-goto-if-not-nil-else-pop)) | |
1431 | ||
1432 | (defconst byte-after-unbind-ops | |
1433 | '(byte-constant byte-dup | |
1434 | byte-symbolp byte-consp byte-stringp byte-listp byte-numberp byte-integerp | |
43fd1680 | 1435 | byte-eq byte-not |
1c393159 | 1436 | byte-cons byte-list1 byte-list2 ; byte-list3 byte-list4 |
cb88b56e RS |
1437 | byte-interactive-p) |
1438 | ;; How about other side-effect-free-ops? Is it safe to move an | |
1439 | ;; error invocation (such as from nth) out of an unwind-protect? | |
43fd1680 RS |
1440 | ;; No, it is not, because the unwind-protect forms can alter |
1441 | ;; the inside of the object to which nth would apply. | |
1442 | ;; For the same reason, byte-equal was deleted from this list. | |
cb88b56e | 1443 | "Byte-codes that can be moved past an unbind.") |
1c393159 JB |
1444 | |
1445 | (defconst byte-compile-side-effect-and-error-free-ops | |
1446 | '(byte-constant byte-dup byte-symbolp byte-consp byte-stringp byte-listp | |
1447 | byte-integerp byte-numberp byte-eq byte-equal byte-not byte-car-safe | |
1448 | byte-cdr-safe byte-cons byte-list1 byte-list2 byte-point byte-point-max | |
1449 | byte-point-min byte-following-char byte-preceding-char | |
1450 | byte-current-column byte-eolp byte-eobp byte-bolp byte-bobp | |
7200d79c | 1451 | byte-current-buffer byte-stack-ref)) |
1c393159 JB |
1452 | |
1453 | (defconst byte-compile-side-effect-free-ops | |
a1506d29 | 1454 | (nconc |
1c393159 JB |
1455 | '(byte-varref byte-nth byte-memq byte-car byte-cdr byte-length byte-aref |
1456 | byte-symbol-value byte-get byte-concat2 byte-concat3 byte-sub1 byte-add1 | |
1457 | byte-eqlsign byte-gtr byte-lss byte-leq byte-geq byte-diff byte-negate | |
1458 | byte-plus byte-max byte-min byte-mult byte-char-after byte-char-syntax | |
1459 | byte-buffer-substring byte-string= byte-string< byte-nthcdr byte-elt | |
ce5b520a | 1460 | byte-member byte-assq byte-quo byte-rem) |
1c393159 JB |
1461 | byte-compile-side-effect-and-error-free-ops)) |
1462 | ||
6b61353c KH |
1463 | ;; This crock is because of the way DEFVAR_BOOL variables work. |
1464 | ;; Consider the code | |
1465 | ;; | |
1466 | ;; (defun foo (flag) | |
1467 | ;; (let ((old-pop-ups pop-up-windows) | |
1468 | ;; (pop-up-windows flag)) | |
1469 | ;; (cond ((not (eq pop-up-windows old-pop-ups)) | |
1470 | ;; (setq old-pop-ups pop-up-windows) | |
1471 | ;; ...)))) | |
1472 | ;; | |
1473 | ;; Uncompiled, old-pop-ups will always be set to nil or t, even if FLAG is | |
1474 | ;; something else. But if we optimize | |
1475 | ;; | |
1476 | ;; varref flag | |
1477 | ;; varbind pop-up-windows | |
1478 | ;; varref pop-up-windows | |
1479 | ;; not | |
1480 | ;; to | |
1481 | ;; varref flag | |
1482 | ;; dup | |
1483 | ;; varbind pop-up-windows | |
1484 | ;; not | |
1485 | ;; | |
1486 | ;; we break the program, because it will appear that pop-up-windows and | |
1487 | ;; old-pop-ups are not EQ when really they are. So we have to know what | |
1488 | ;; the BOOL variables are, and not perform this optimization on them. | |
1489 | ||
1490 | ;; The variable `byte-boolean-vars' is now primitive and updated | |
1491 | ;; automatically by DEFVAR_BOOL. | |
1c393159 | 1492 | |
bba752f8 | 1493 | (defun byte-optimize-lapcode (lap &optional _for-effect) |
6b61353c KH |
1494 | "Simple peephole optimizer. LAP is both modified and returned. |
1495 | If FOR-EFFECT is non-nil, the return value is assumed to be of no importance." | |
944425c0 DL |
1496 | (let (lap0 |
1497 | lap1 | |
1498 | lap2 | |
1c393159 JB |
1499 | (keep-going 'first-time) |
1500 | (add-depth 0) | |
1501 | rest tmp tmp2 tmp3 | |
1502 | (side-effect-free (if byte-compile-delete-errors | |
1503 | byte-compile-side-effect-free-ops | |
1504 | byte-compile-side-effect-and-error-free-ops))) | |
1505 | (while keep-going | |
1506 | (or (eq keep-going 'first-time) | |
1507 | (byte-compile-log-lap " ---- next pass")) | |
1508 | (setq rest lap | |
1509 | keep-going nil) | |
1510 | (while rest | |
1511 | (setq lap0 (car rest) | |
1512 | lap1 (nth 1 rest) | |
1513 | lap2 (nth 2 rest)) | |
1514 | ||
1515 | ;; You may notice that sequences like "dup varset discard" are | |
1516 | ;; optimized but sequences like "dup varset TAG1: discard" are not. | |
1517 | ;; You may be tempted to change this; resist that temptation. | |
1518 | (cond ;; | |
1519 | ;; <side-effect-free> pop --> <deleted> | |
1520 | ;; ...including: | |
1521 | ;; const-X pop --> <deleted> | |
1522 | ;; varref-X pop --> <deleted> | |
1523 | ;; dup pop --> <deleted> | |
1524 | ;; | |
1525 | ((and (eq 'byte-discard (car lap1)) | |
1526 | (memq (car lap0) side-effect-free)) | |
1527 | (setq keep-going t) | |
a647cb26 | 1528 | (setq tmp (aref byte-stack+-info (symbol-value (car lap0)))) |
1c393159 | 1529 | (setq rest (cdr rest)) |
a647cb26 | 1530 | (cond ((= tmp 1) |
1c393159 JB |
1531 | (byte-compile-log-lap |
1532 | " %s discard\t-->\t<deleted>" lap0) | |
1533 | (setq lap (delq lap0 (delq lap1 lap)))) | |
a647cb26 | 1534 | ((= tmp 0) |
1c393159 JB |
1535 | (byte-compile-log-lap |
1536 | " %s discard\t-->\t<deleted> discard" lap0) | |
1537 | (setq lap (delq lap0 lap))) | |
a647cb26 | 1538 | ((= tmp -1) |
1c393159 JB |
1539 | (byte-compile-log-lap |
1540 | " %s discard\t-->\tdiscard discard" lap0) | |
1541 | (setcar lap0 'byte-discard) | |
1542 | (setcdr lap0 0)) | |
a647cb26 | 1543 | ((error "Optimizer error: too much on the stack")))) |
1c393159 JB |
1544 | ;; |
1545 | ;; goto*-X X: --> X: | |
1546 | ;; | |
1547 | ((and (memq (car lap0) byte-goto-ops) | |
1548 | (eq (cdr lap0) lap1)) | |
1549 | (cond ((eq (car lap0) 'byte-goto) | |
1550 | (setq lap (delq lap0 lap)) | |
1551 | (setq tmp "<deleted>")) | |
1552 | ((memq (car lap0) byte-goto-always-pop-ops) | |
1553 | (setcar lap0 (setq tmp 'byte-discard)) | |
1554 | (setcdr lap0 0)) | |
1555 | ((error "Depth conflict at tag %d" (nth 2 lap0)))) | |
1556 | (and (memq byte-optimize-log '(t byte)) | |
1557 | (byte-compile-log " (goto %s) %s:\t-->\t%s %s:" | |
1558 | (nth 1 lap1) (nth 1 lap1) | |
1559 | tmp (nth 1 lap1))) | |
1560 | (setq keep-going t)) | |
1561 | ;; | |
1562 | ;; varset-X varref-X --> dup varset-X | |
1563 | ;; varbind-X varref-X --> dup varbind-X | |
1564 | ;; const/dup varset-X varref-X --> const/dup varset-X const/dup | |
1565 | ;; const/dup varbind-X varref-X --> const/dup varbind-X const/dup | |
1566 | ;; The latter two can enable other optimizations. | |
1567 | ;; | |
3e21b6a7 SM |
1568 | ;; For lexical variables, we could do the same |
1569 | ;; stack-set-X+1 stack-ref-X --> dup stack-set-X+2 | |
1570 | ;; but this is a very minor gain, since dup is stack-ref-0, | |
1571 | ;; i.e. it's only better if X>5, and even then it comes | |
5a5fa834 | 1572 | ;; at the cost of an extra stack slot. Let's not bother. |
3e21b6a7 SM |
1573 | ((and (eq 'byte-varref (car lap2)) |
1574 | (eq (cdr lap1) (cdr lap2)) | |
1575 | (memq (car lap1) '(byte-varset byte-varbind))) | |
1576 | (if (and (setq tmp (memq (car (cdr lap2)) byte-boolean-vars)) | |
1c393159 JB |
1577 | (not (eq (car lap0) 'byte-constant))) |
1578 | nil | |
1579 | (setq keep-going t) | |
4dd1c416 SM |
1580 | (if (memq (car lap0) '(byte-constant byte-dup)) |
1581 | (progn | |
1582 | (setq tmp (if (or (not tmp) | |
1583 | (macroexp--const-symbol-p | |
1584 | (car (cdr lap0)))) | |
1585 | (cdr lap0) | |
1586 | (byte-compile-get-constant t))) | |
1c393159 JB |
1587 | (byte-compile-log-lap " %s %s %s\t-->\t%s %s %s" |
1588 | lap0 lap1 lap2 lap0 lap1 | |
1589 | (cons (car lap0) tmp)) | |
1590 | (setcar lap2 (car lap0)) | |
1591 | (setcdr lap2 tmp)) | |
1592 | (byte-compile-log-lap " %s %s\t-->\tdup %s" lap1 lap2 lap1) | |
1593 | (setcar lap2 (car lap1)) | |
1594 | (setcar lap1 'byte-dup) | |
1595 | (setcdr lap1 0) | |
1596 | ;; The stack depth gets locally increased, so we will | |
1597 | ;; increase maxdepth in case depth = maxdepth here. | |
1598 | ;; This can cause the third argument to byte-code to | |
1599 | ;; be larger than necessary. | |
1600 | (setq add-depth 1)))) | |
1601 | ;; | |
1602 | ;; dup varset-X discard --> varset-X | |
1603 | ;; dup varbind-X discard --> varbind-X | |
3e21b6a7 | 1604 | ;; dup stack-set-X discard --> stack-set-X-1 |
1c393159 JB |
1605 | ;; (the varbind variant can emerge from other optimizations) |
1606 | ;; | |
1607 | ((and (eq 'byte-dup (car lap0)) | |
1608 | (eq 'byte-discard (car lap2)) | |
3e21b6a7 SM |
1609 | (memq (car lap1) '(byte-varset byte-varbind |
1610 | byte-stack-set))) | |
1c393159 JB |
1611 | (byte-compile-log-lap " dup %s discard\t-->\t%s" lap1 lap1) |
1612 | (setq keep-going t | |
a647cb26 | 1613 | rest (cdr rest)) |
f80efb86 | 1614 | (if (eq 'byte-stack-set (car lap1)) (cl-decf (cdr lap1))) |
1c393159 JB |
1615 | (setq lap (delq lap0 (delq lap2 lap)))) |
1616 | ;; | |
1617 | ;; not goto-X-if-nil --> goto-X-if-non-nil | |
1618 | ;; not goto-X-if-non-nil --> goto-X-if-nil | |
1619 | ;; | |
1620 | ;; it is wrong to do the same thing for the -else-pop variants. | |
1621 | ;; | |
1622 | ((and (eq 'byte-not (car lap0)) | |
ba83908c | 1623 | (memq (car lap1) '(byte-goto-if-nil byte-goto-if-not-nil))) |
1c393159 JB |
1624 | (byte-compile-log-lap " not %s\t-->\t%s" |
1625 | lap1 | |
1626 | (cons | |
1627 | (if (eq (car lap1) 'byte-goto-if-nil) | |
1628 | 'byte-goto-if-not-nil | |
1629 | 'byte-goto-if-nil) | |
1630 | (cdr lap1))) | |
1631 | (setcar lap1 (if (eq (car lap1) 'byte-goto-if-nil) | |
1632 | 'byte-goto-if-not-nil | |
1633 | 'byte-goto-if-nil)) | |
1634 | (setq lap (delq lap0 lap)) | |
a647cb26 | 1635 | (setq keep-going t)) |
1c393159 JB |
1636 | ;; |
1637 | ;; goto-X-if-nil goto-Y X: --> goto-Y-if-non-nil X: | |
1638 | ;; goto-X-if-non-nil goto-Y X: --> goto-Y-if-nil X: | |
1639 | ;; | |
1640 | ;; it is wrong to do the same thing for the -else-pop variants. | |
a1506d29 | 1641 | ;; |
ba83908c SM |
1642 | ((and (memq (car lap0) |
1643 | '(byte-goto-if-nil byte-goto-if-not-nil)) ; gotoX | |
1c393159 JB |
1644 | (eq 'byte-goto (car lap1)) ; gotoY |
1645 | (eq (cdr lap0) lap2)) ; TAG X | |
1646 | (let ((inverse (if (eq 'byte-goto-if-nil (car lap0)) | |
1647 | 'byte-goto-if-not-nil 'byte-goto-if-nil))) | |
1648 | (byte-compile-log-lap " %s %s %s:\t-->\t%s %s:" | |
1649 | lap0 lap1 lap2 | |
1650 | (cons inverse (cdr lap1)) lap2) | |
a647cb26 | 1651 | (setq lap (delq lap0 lap)) |
1c393159 JB |
1652 | (setcar lap1 inverse) |
1653 | (setq keep-going t))) | |
1654 | ;; | |
1655 | ;; const goto-if-* --> whatever | |
1656 | ;; | |
1657 | ((and (eq 'byte-constant (car lap0)) | |
876c194c SM |
1658 | (memq (car lap1) byte-conditional-ops) |
1659 | ;; If the `byte-constant's cdr is not a cons cell, it has | |
1660 | ;; to be an index into the constant pool); even though | |
1661 | ;; it'll be a constant, that constant is not known yet | |
1662 | ;; (it's typically a free variable of a closure, so will | |
1663 | ;; only be known when the closure will be built at | |
1664 | ;; run-time). | |
1665 | (consp (cdr lap0))) | |
ba83908c SM |
1666 | (cond ((if (memq (car lap1) '(byte-goto-if-nil |
1667 | byte-goto-if-nil-else-pop)) | |
876c194c SM |
1668 | (car (cdr lap0)) |
1669 | (not (car (cdr lap0)))) | |
1c393159 JB |
1670 | (byte-compile-log-lap " %s %s\t-->\t<deleted>" |
1671 | lap0 lap1) | |
1672 | (setq rest (cdr rest) | |
1673 | lap (delq lap0 (delq lap1 lap)))) | |
1674 | (t | |
b9598260 SM |
1675 | (byte-compile-log-lap " %s %s\t-->\t%s" |
1676 | lap0 lap1 | |
1677 | (cons 'byte-goto (cdr lap1))) | |
1678 | (when (memq (car lap1) byte-goto-always-pop-ops) | |
1679 | (setq lap (delq lap0 lap))) | |
1c393159 | 1680 | (setcar lap1 'byte-goto))) |
876c194c | 1681 | (setq keep-going t)) |
1c393159 JB |
1682 | ;; |
1683 | ;; varref-X varref-X --> varref-X dup | |
1684 | ;; varref-X [dup ...] varref-X --> varref-X [dup ...] dup | |
876c194c | 1685 | ;; stackref-X [dup ...] stackref-X+N --> stackref-X [dup ...] dup |
1c393159 JB |
1686 | ;; We don't optimize the const-X variations on this here, |
1687 | ;; because that would inhibit some goto optimizations; we | |
1688 | ;; optimize the const-X case after all other optimizations. | |
1689 | ;; | |
b9598260 | 1690 | ((and (memq (car lap0) '(byte-varref byte-stack-ref)) |
1c393159 | 1691 | (progn |
3e21b6a7 SM |
1692 | (setq tmp (cdr rest)) |
1693 | (setq tmp2 0) | |
1c393159 | 1694 | (while (eq (car (car tmp)) 'byte-dup) |
3e21b6a7 SM |
1695 | (setq tmp2 (1+ tmp2)) |
1696 | (setq tmp (cdr tmp))) | |
1c393159 | 1697 | t) |
3e21b6a7 SM |
1698 | (eq (if (eq 'byte-stack-ref (car lap0)) |
1699 | (+ tmp2 1 (cdr lap0)) | |
1700 | (cdr lap0)) | |
1701 | (cdr (car tmp))) | |
1702 | (eq (car lap0) (car (car tmp)))) | |
1c393159 JB |
1703 | (if (memq byte-optimize-log '(t byte)) |
1704 | (let ((str "")) | |
1705 | (setq tmp2 (cdr rest)) | |
1706 | (while (not (eq tmp tmp2)) | |
1707 | (setq tmp2 (cdr tmp2) | |
1708 | str (concat str " dup"))) | |
1709 | (byte-compile-log-lap " %s%s %s\t-->\t%s%s dup" | |
1710 | lap0 str lap0 lap0 str))) | |
1711 | (setq keep-going t) | |
1712 | (setcar (car tmp) 'byte-dup) | |
1713 | (setcdr (car tmp) 0) | |
a647cb26 | 1714 | (setq rest tmp)) |
1c393159 JB |
1715 | ;; |
1716 | ;; TAG1: TAG2: --> TAG1: <deleted> | |
1717 | ;; (and other references to TAG2 are replaced with TAG1) | |
1718 | ;; | |
1719 | ((and (eq (car lap0) 'TAG) | |
1720 | (eq (car lap1) 'TAG)) | |
1721 | (and (memq byte-optimize-log '(t byte)) | |
eb8c3be9 | 1722 | (byte-compile-log " adjacent tags %d and %d merged" |
1c393159 JB |
1723 | (nth 1 lap1) (nth 1 lap0))) |
1724 | (setq tmp3 lap) | |
1725 | (while (setq tmp2 (rassq lap0 tmp3)) | |
1726 | (setcdr tmp2 lap1) | |
1727 | (setq tmp3 (cdr (memq tmp2 tmp3)))) | |
1728 | (setq lap (delq lap0 lap) | |
1729 | keep-going t)) | |
1730 | ;; | |
1731 | ;; unused-TAG: --> <deleted> | |
1732 | ;; | |
1733 | ((and (eq 'TAG (car lap0)) | |
1734 | (not (rassq lap0 lap))) | |
1735 | (and (memq byte-optimize-log '(t byte)) | |
1736 | (byte-compile-log " unused tag %d removed" (nth 1 lap0))) | |
1737 | (setq lap (delq lap0 lap) | |
1738 | keep-going t)) | |
1739 | ;; | |
1740 | ;; goto ... --> goto <delete until TAG or end> | |
1741 | ;; return ... --> return <delete until TAG or end> | |
1742 | ;; | |
1743 | ((and (memq (car lap0) '(byte-goto byte-return)) | |
1744 | (not (memq (car lap1) '(TAG nil)))) | |
1745 | (setq tmp rest) | |
1746 | (let ((i 0) | |
1747 | (opt-p (memq byte-optimize-log '(t lap))) | |
1748 | str deleted) | |
1749 | (while (and (setq tmp (cdr tmp)) | |
1750 | (not (eq 'TAG (car (car tmp))))) | |
1751 | (if opt-p (setq deleted (cons (car tmp) deleted) | |
1752 | str (concat str " %s") | |
1753 | i (1+ i)))) | |
1754 | (if opt-p | |
a1506d29 | 1755 | (let ((tagstr |
1c393159 | 1756 | (if (eq 'TAG (car (car tmp))) |
dec4e22e | 1757 | (format "%d:" (car (cdr (car tmp)))) |
1c393159 JB |
1758 | (or (car tmp) "")))) |
1759 | (if (< i 6) | |
1760 | (apply 'byte-compile-log-lap-1 | |
1761 | (concat " %s" str | |
1762 | " %s\t-->\t%s <deleted> %s") | |
1763 | lap0 | |
1764 | (nconc (nreverse deleted) | |
1765 | (list tagstr lap0 tagstr))) | |
1766 | (byte-compile-log-lap | |
1767 | " %s <%d unreachable op%s> %s\t-->\t%s <deleted> %s" | |
1768 | lap0 i (if (= i 1) "" "s") | |
1769 | tagstr lap0 tagstr)))) | |
1770 | (rplacd rest tmp)) | |
1771 | (setq keep-going t)) | |
1772 | ;; | |
1773 | ;; <safe-op> unbind --> unbind <safe-op> | |
1774 | ;; (this may enable other optimizations.) | |
1775 | ;; | |
1776 | ((and (eq 'byte-unbind (car lap1)) | |
1777 | (memq (car lap0) byte-after-unbind-ops)) | |
1778 | (byte-compile-log-lap " %s %s\t-->\t%s %s" lap0 lap1 lap1 lap0) | |
1779 | (setcar rest lap1) | |
1780 | (setcar (cdr rest) lap0) | |
a647cb26 | 1781 | (setq keep-going t)) |
1c393159 JB |
1782 | ;; |
1783 | ;; varbind-X unbind-N --> discard unbind-(N-1) | |
1784 | ;; save-excursion unbind-N --> unbind-(N-1) | |
1785 | ;; save-restriction unbind-N --> unbind-(N-1) | |
1786 | ;; | |
1787 | ((and (eq 'byte-unbind (car lap1)) | |
1788 | (memq (car lap0) '(byte-varbind byte-save-excursion | |
1789 | byte-save-restriction)) | |
1790 | (< 0 (cdr lap1))) | |
1791 | (if (zerop (setcdr lap1 (1- (cdr lap1)))) | |
1792 | (delq lap1 rest)) | |
1793 | (if (eq (car lap0) 'byte-varbind) | |
1794 | (setcar rest (cons 'byte-discard 0)) | |
1795 | (setq lap (delq lap0 lap))) | |
1796 | (byte-compile-log-lap " %s %s\t-->\t%s %s" | |
1797 | lap0 (cons (car lap1) (1+ (cdr lap1))) | |
1798 | (if (eq (car lap0) 'byte-varbind) | |
1799 | (car rest) | |
1800 | (car (cdr rest))) | |
1801 | (if (and (/= 0 (cdr lap1)) | |
1802 | (eq (car lap0) 'byte-varbind)) | |
1803 | (car (cdr rest)) | |
1804 | "")) | |
1805 | (setq keep-going t)) | |
1806 | ;; | |
1807 | ;; goto*-X ... X: goto-Y --> goto*-Y | |
1808 | ;; goto-X ... X: return --> return | |
1809 | ;; | |
1810 | ((and (memq (car lap0) byte-goto-ops) | |
1811 | (memq (car (setq tmp (nth 1 (memq (cdr lap0) lap)))) | |
1812 | '(byte-goto byte-return))) | |
1813 | (cond ((and (not (eq tmp lap0)) | |
1814 | (or (eq (car lap0) 'byte-goto) | |
1815 | (eq (car tmp) 'byte-goto))) | |
1816 | (byte-compile-log-lap " %s [%s]\t-->\t%s" | |
1817 | (car lap0) tmp tmp) | |
1818 | (if (eq (car tmp) 'byte-return) | |
1819 | (setcar lap0 'byte-return)) | |
1820 | (setcdr lap0 (cdr tmp)) | |
1821 | (setq keep-going t)))) | |
1822 | ;; | |
1823 | ;; goto-*-else-pop X ... X: goto-if-* --> whatever | |
1824 | ;; goto-*-else-pop X ... X: discard --> whatever | |
1825 | ;; | |
1826 | ((and (memq (car lap0) '(byte-goto-if-nil-else-pop | |
1827 | byte-goto-if-not-nil-else-pop)) | |
1828 | (memq (car (car (setq tmp (cdr (memq (cdr lap0) lap))))) | |
1829 | (eval-when-compile | |
1830 | (cons 'byte-discard byte-conditional-ops))) | |
1831 | (not (eq lap0 (car tmp)))) | |
1832 | (setq tmp2 (car tmp)) | |
1833 | (setq tmp3 (assq (car lap0) '((byte-goto-if-nil-else-pop | |
1834 | byte-goto-if-nil) | |
1835 | (byte-goto-if-not-nil-else-pop | |
1836 | byte-goto-if-not-nil)))) | |
1837 | (if (memq (car tmp2) tmp3) | |
1838 | (progn (setcar lap0 (car tmp2)) | |
1839 | (setcdr lap0 (cdr tmp2)) | |
1840 | (byte-compile-log-lap " %s-else-pop [%s]\t-->\t%s" | |
1841 | (car lap0) tmp2 lap0)) | |
1842 | ;; Get rid of the -else-pop's and jump one step further. | |
1843 | (or (eq 'TAG (car (nth 1 tmp))) | |
1844 | (setcdr tmp (cons (byte-compile-make-tag) | |
1845 | (cdr tmp)))) | |
1846 | (byte-compile-log-lap " %s [%s]\t-->\t%s <skip>" | |
1847 | (car lap0) tmp2 (nth 1 tmp3)) | |
1848 | (setcar lap0 (nth 1 tmp3)) | |
1849 | (setcdr lap0 (nth 1 tmp))) | |
1850 | (setq keep-going t)) | |
1851 | ;; | |
1852 | ;; const goto-X ... X: goto-if-* --> whatever | |
1853 | ;; const goto-X ... X: discard --> whatever | |
1854 | ;; | |
1855 | ((and (eq (car lap0) 'byte-constant) | |
1856 | (eq (car lap1) 'byte-goto) | |
1857 | (memq (car (car (setq tmp (cdr (memq (cdr lap1) lap))))) | |
1858 | (eval-when-compile | |
1859 | (cons 'byte-discard byte-conditional-ops))) | |
1860 | (not (eq lap1 (car tmp)))) | |
1861 | (setq tmp2 (car tmp)) | |
876c194c SM |
1862 | (cond ((when (consp (cdr lap0)) |
1863 | (memq (car tmp2) | |
1864 | (if (null (car (cdr lap0))) | |
1865 | '(byte-goto-if-nil byte-goto-if-nil-else-pop) | |
1866 | '(byte-goto-if-not-nil | |
1867 | byte-goto-if-not-nil-else-pop)))) | |
1c393159 JB |
1868 | (byte-compile-log-lap " %s goto [%s]\t-->\t%s %s" |
1869 | lap0 tmp2 lap0 tmp2) | |
1870 | (setcar lap1 (car tmp2)) | |
1871 | (setcdr lap1 (cdr tmp2)) | |
1872 | ;; Let next step fix the (const,goto-if*) sequence. | |
876c194c SM |
1873 | (setq rest (cons nil rest)) |
1874 | (setq keep-going t)) | |
1875 | ((or (consp (cdr lap0)) | |
1876 | (eq (car tmp2) 'byte-discard)) | |
1c393159 JB |
1877 | ;; Jump one step further |
1878 | (byte-compile-log-lap | |
1879 | " %s goto [%s]\t-->\t<deleted> goto <skip>" | |
1880 | lap0 tmp2) | |
1881 | (or (eq 'TAG (car (nth 1 tmp))) | |
1882 | (setcdr tmp (cons (byte-compile-make-tag) | |
1883 | (cdr tmp)))) | |
1884 | (setcdr lap1 (car (cdr tmp))) | |
876c194c SM |
1885 | (setq lap (delq lap0 lap)) |
1886 | (setq keep-going t)))) | |
1c393159 JB |
1887 | ;; |
1888 | ;; X: varref-Y ... varset-Y goto-X --> | |
1889 | ;; X: varref-Y Z: ... dup varset-Y goto-Z | |
1890 | ;; (varset-X goto-BACK, BACK: varref-X --> copy the varref down.) | |
1891 | ;; (This is so usual for while loops that it is worth handling). | |
3e21b6a7 SM |
1892 | ;; |
1893 | ;; Here again, we could do it for stack-ref/stack-set, but | |
1894 | ;; that's replacing a stack-ref-Y with a stack-ref-0, which | |
1895 | ;; is a very minor improvement (if any), at the cost of | |
1896 | ;; more stack use and more byte-code. Let's not do it. | |
1c393159 | 1897 | ;; |
3e21b6a7 | 1898 | ((and (eq (car lap1) 'byte-varset) |
1c393159 JB |
1899 | (eq (car lap2) 'byte-goto) |
1900 | (not (memq (cdr lap2) rest)) ;Backwards jump | |
1901 | (eq (car (car (setq tmp (cdr (memq (cdr lap2) lap))))) | |
a647cb26 | 1902 | 'byte-varref) |
1c393159 | 1903 | (eq (cdr (car tmp)) (cdr lap1)) |
a647cb26 | 1904 | (not (memq (car (cdr lap1)) byte-boolean-vars))) |
1c393159 JB |
1905 | ;;(byte-compile-log-lap " Pulled %s to end of loop" (car tmp)) |
1906 | (let ((newtag (byte-compile-make-tag))) | |
1907 | (byte-compile-log-lap | |
1908 | " %s: %s ... %s %s\t-->\t%s: %s %s: ... %s %s %s" | |
1909 | (nth 1 (cdr lap2)) (car tmp) | |
1910 | lap1 lap2 | |
1911 | (nth 1 (cdr lap2)) (car tmp) | |
1912 | (nth 1 newtag) 'byte-dup lap1 | |
1913 | (cons 'byte-goto newtag) | |
1914 | ) | |
1915 | (setcdr rest (cons (cons 'byte-dup 0) (cdr rest))) | |
1916 | (setcdr tmp (cons (setcdr lap2 newtag) (cdr tmp)))) | |
1917 | (setq add-depth 1) | |
1918 | (setq keep-going t)) | |
1919 | ;; | |
1920 | ;; goto-X Y: ... X: goto-if*-Y --> goto-if-not-*-X+1 Y: | |
1921 | ;; (This can pull the loop test to the end of the loop) | |
1922 | ;; | |
1923 | ((and (eq (car lap0) 'byte-goto) | |
1924 | (eq (car lap1) 'TAG) | |
1925 | (eq lap1 | |
1926 | (cdr (car (setq tmp (cdr (memq (cdr lap0) lap)))))) | |
1927 | (memq (car (car tmp)) | |
1928 | '(byte-goto byte-goto-if-nil byte-goto-if-not-nil | |
1929 | byte-goto-if-nil-else-pop))) | |
1930 | ;; (byte-compile-log-lap " %s %s, %s %s --> moved conditional" | |
1931 | ;; lap0 lap1 (cdr lap0) (car tmp)) | |
1932 | (let ((newtag (byte-compile-make-tag))) | |
1933 | (byte-compile-log-lap | |
1934 | "%s %s: ... %s: %s\t-->\t%s ... %s:" | |
1935 | lap0 (nth 1 lap1) (nth 1 (cdr lap0)) (car tmp) | |
1936 | (cons (cdr (assq (car (car tmp)) | |
1937 | '((byte-goto-if-nil . byte-goto-if-not-nil) | |
1938 | (byte-goto-if-not-nil . byte-goto-if-nil) | |
1939 | (byte-goto-if-nil-else-pop . | |
1940 | byte-goto-if-not-nil-else-pop) | |
1941 | (byte-goto-if-not-nil-else-pop . | |
1942 | byte-goto-if-nil-else-pop)))) | |
1943 | newtag) | |
a1506d29 | 1944 | |
1c393159 JB |
1945 | (nth 1 newtag) |
1946 | ) | |
1947 | (setcdr tmp (cons (setcdr lap0 newtag) (cdr tmp))) | |
1948 | (if (eq (car (car tmp)) 'byte-goto-if-nil-else-pop) | |
1949 | ;; We can handle this case but not the -if-not-nil case, | |
1950 | ;; because we won't know which non-nil constant to push. | |
1951 | (setcdr rest (cons (cons 'byte-constant | |
1952 | (byte-compile-get-constant nil)) | |
1953 | (cdr rest)))) | |
1954 | (setcar lap0 (nth 1 (memq (car (car tmp)) | |
1955 | '(byte-goto-if-nil-else-pop | |
1956 | byte-goto-if-not-nil | |
1957 | byte-goto-if-nil | |
1958 | byte-goto-if-not-nil | |
1959 | byte-goto byte-goto)))) | |
1960 | ) | |
a647cb26 | 1961 | (setq keep-going t)) |
1c393159 JB |
1962 | ) |
1963 | (setq rest (cdr rest))) | |
1964 | ) | |
1965 | ;; Cleanup stage: | |
1966 | ;; Rebuild byte-compile-constants / byte-compile-variables. | |
1967 | ;; Simple optimizations that would inhibit other optimizations if they | |
1968 | ;; were done in the optimizing loop, and optimizations which there is no | |
3e21b6a7 | 1969 | ;; need to do more than once. |
1c393159 JB |
1970 | (setq byte-compile-constants nil |
1971 | byte-compile-variables nil) | |
a647cb26 | 1972 | (setq rest lap) |
b9598260 | 1973 | (byte-compile-log-lap " ---- final pass") |
1c393159 JB |
1974 | (while rest |
1975 | (setq lap0 (car rest) | |
1976 | lap1 (nth 1 rest)) | |
1977 | (if (memq (car lap0) byte-constref-ops) | |
e2abe5a1 | 1978 | (if (memq (car lap0) '(byte-constant byte-constant2)) |
3ecf67a1 | 1979 | (unless (memq (cdr lap0) byte-compile-constants) |
1c393159 | 1980 | (setq byte-compile-constants (cons (cdr lap0) |
3ecf67a1 GM |
1981 | byte-compile-constants))) |
1982 | (unless (memq (cdr lap0) byte-compile-variables) | |
1983 | (setq byte-compile-variables (cons (cdr lap0) | |
1984 | byte-compile-variables))))) | |
1c393159 JB |
1985 | (cond (;; |
1986 | ;; const-C varset-X const-C --> const-C dup varset-X | |
1987 | ;; const-C varbind-X const-C --> const-C dup varbind-X | |
1988 | ;; | |
1989 | (and (eq (car lap0) 'byte-constant) | |
1990 | (eq (car (nth 2 rest)) 'byte-constant) | |
3ecf67a1 | 1991 | (eq (cdr lap0) (cdr (nth 2 rest))) |
1c393159 JB |
1992 | (memq (car lap1) '(byte-varbind byte-varset))) |
1993 | (byte-compile-log-lap " %s %s %s\t-->\t%s dup %s" | |
1994 | lap0 lap1 lap0 lap0 lap1) | |
1995 | (setcar (cdr (cdr rest)) (cons (car lap1) (cdr lap1))) | |
1996 | (setcar (cdr rest) (cons 'byte-dup 0)) | |
1997 | (setq add-depth 1)) | |
1998 | ;; | |
1999 | ;; const-X [dup/const-X ...] --> const-X [dup ...] dup | |
2000 | ;; varref-X [dup/varref-X ...] --> varref-X [dup ...] dup | |
2001 | ;; | |
2002 | ((memq (car lap0) '(byte-constant byte-varref)) | |
2003 | (setq tmp rest | |
2004 | tmp2 nil) | |
2005 | (while (progn | |
2006 | (while (eq 'byte-dup (car (car (setq tmp (cdr tmp)))))) | |
2007 | (and (eq (cdr lap0) (cdr (car tmp))) | |
2008 | (eq (car lap0) (car (car tmp))))) | |
2009 | (setcar tmp (cons 'byte-dup 0)) | |
2010 | (setq tmp2 t)) | |
2011 | (if tmp2 | |
2012 | (byte-compile-log-lap | |
dec4e22e | 2013 | " %s [dup/%s]...\t-->\t%s dup..." lap0 lap0 lap0))) |
1c393159 JB |
2014 | ;; |
2015 | ;; unbind-N unbind-M --> unbind-(N+M) | |
2016 | ;; | |
2017 | ((and (eq 'byte-unbind (car lap0)) | |
2018 | (eq 'byte-unbind (car lap1))) | |
2019 | (byte-compile-log-lap " %s %s\t-->\t%s" lap0 lap1 | |
2020 | (cons 'byte-unbind | |
2021 | (+ (cdr lap0) (cdr lap1)))) | |
1c393159 JB |
2022 | (setq lap (delq lap0 lap)) |
2023 | (setcdr lap1 (+ (cdr lap1) (cdr lap0)))) | |
7200d79c | 2024 | |
b9598260 SM |
2025 | ;; |
2026 | ;; stack-set-M [discard/discardN ...] --> discardN-preserve-tos | |
2027 | ;; stack-set-M [discard/discardN ...] --> discardN | |
2028 | ;; | |
3e21b6a7 SM |
2029 | ((and (eq (car lap0) 'byte-stack-set) |
2030 | (memq (car lap1) '(byte-discard byte-discardN)) | |
2031 | (progn | |
2032 | ;; See if enough discard operations follow to expose or | |
2033 | ;; destroy the value stored by the stack-set. | |
2034 | (setq tmp (cdr rest)) | |
2035 | (setq tmp2 (1- (cdr lap0))) | |
2036 | (setq tmp3 0) | |
2037 | (while (memq (car (car tmp)) '(byte-discard byte-discardN)) | |
2038 | (setq tmp3 | |
2039 | (+ tmp3 (if (eq (car (car tmp)) 'byte-discard) | |
2040 | 1 | |
2041 | (cdr (car tmp))))) | |
2042 | (setq tmp (cdr tmp))) | |
2043 | (>= tmp3 tmp2))) | |
2044 | ;; Do the optimization. | |
b9598260 | 2045 | (setq lap (delq lap0 lap)) |
3e21b6a7 SM |
2046 | (setcar lap1 |
2047 | (if (= tmp2 tmp3) | |
7200d79c SM |
2048 | ;; The value stored is the new TOS, so pop one more |
2049 | ;; value (to get rid of the old value) using the | |
2050 | ;; TOS-preserving discard operator. | |
3e21b6a7 SM |
2051 | 'byte-discardN-preserve-tos |
2052 | ;; Otherwise, the value stored is lost, so just use a | |
2053 | ;; normal discard. | |
2054 | 'byte-discardN)) | |
2055 | (setcdr lap1 (1+ tmp3)) | |
b9598260 | 2056 | (setcdr (cdr rest) tmp) |
b9598260 | 2057 | (byte-compile-log-lap " %s [discard/discardN]...\t-->\t%s" |
3e21b6a7 | 2058 | lap0 lap1)) |
b9598260 SM |
2059 | |
2060 | ;; | |
2061 | ;; discard/discardN/discardN-preserve-tos-X discard/discardN-Y --> | |
2062 | ;; discardN-(X+Y) | |
2063 | ;; | |
2064 | ((and (memq (car lap0) | |
7200d79c | 2065 | '(byte-discard byte-discardN |
b9598260 SM |
2066 | byte-discardN-preserve-tos)) |
2067 | (memq (car lap1) '(byte-discard byte-discardN))) | |
2068 | (setq lap (delq lap0 lap)) | |
2069 | (byte-compile-log-lap | |
2070 | " %s %s\t-->\t(discardN %s)" | |
2071 | lap0 lap1 | |
2072 | (+ (if (eq (car lap0) 'byte-discard) 1 (cdr lap0)) | |
2073 | (if (eq (car lap1) 'byte-discard) 1 (cdr lap1)))) | |
2074 | (setcdr lap1 (+ (if (eq (car lap0) 'byte-discard) 1 (cdr lap0)) | |
2075 | (if (eq (car lap1) 'byte-discard) 1 (cdr lap1)))) | |
a647cb26 | 2076 | (setcar lap1 'byte-discardN)) |
b9598260 SM |
2077 | |
2078 | ;; | |
2079 | ;; discardN-preserve-tos-X discardN-preserve-tos-Y --> | |
2080 | ;; discardN-preserve-tos-(X+Y) | |
2081 | ;; | |
2082 | ((and (eq (car lap0) 'byte-discardN-preserve-tos) | |
2083 | (eq (car lap1) 'byte-discardN-preserve-tos)) | |
2084 | (setq lap (delq lap0 lap)) | |
2085 | (setcdr lap1 (+ (cdr lap0) (cdr lap1))) | |
b9598260 SM |
2086 | (byte-compile-log-lap " %s %s\t-->\t%s" lap0 lap1 (car rest))) |
2087 | ||
2088 | ;; | |
2089 | ;; discardN-preserve-tos return --> return | |
2090 | ;; dup return --> return | |
2091 | ;; stack-set-N return --> return ; where N is TOS-1 | |
2092 | ;; | |
3e21b6a7 SM |
2093 | ((and (eq (car lap1) 'byte-return) |
2094 | (or (memq (car lap0) '(byte-discardN-preserve-tos byte-dup)) | |
2095 | (and (eq (car lap0) 'byte-stack-set) | |
2096 | (= (cdr lap0) 1)))) | |
2097 | ;; The byte-code interpreter will pop the stack for us, so | |
2098 | ;; we can just leave stuff on it. | |
b9598260 | 2099 | (setq lap (delq lap0 lap)) |
b9598260 | 2100 | (byte-compile-log-lap " %s %s\t-->\t%s" lap0 lap1 lap1)) |
3e21b6a7 | 2101 | ) |
1c393159 JB |
2102 | (setq rest (cdr rest))) |
2103 | (setq byte-compile-maxdepth (+ byte-compile-maxdepth add-depth))) | |
2104 | lap) | |
2105 | ||
1ffa4286 | 2106 | (provide 'byte-opt) |
1c393159 JB |
2107 | |
2108 | \f | |
2109 | ;; To avoid "lisp nesting exceeds max-lisp-eval-depth" when this file compiles | |
2110 | ;; itself, compile some of its most used recursive functions (at load time). | |
2111 | ;; | |
2112 | (eval-when-compile | |
96d699f3 | 2113 | (or (byte-code-function-p (symbol-function 'byte-optimize-form)) |
1c393159 JB |
2114 | (assq 'byte-code (symbol-function 'byte-optimize-form)) |
2115 | (let ((byte-optimize nil) | |
2116 | (byte-compile-warnings nil)) | |
988e2906 GM |
2117 | (mapc (lambda (x) |
2118 | (or noninteractive (message "compiling %s..." x)) | |
2119 | (byte-compile x) | |
2120 | (or noninteractive (message "compiling %s...done" x))) | |
2121 | '(byte-optimize-form | |
2122 | byte-optimize-body | |
2123 | byte-optimize-predicate | |
2124 | byte-optimize-binary-predicate | |
2125 | ;; Inserted some more than necessary, to speed it up. | |
2126 | byte-optimize-form-code-walker | |
2127 | byte-optimize-lapcode)))) | |
1c393159 | 2128 | nil) |
3eac9910 JB |
2129 | |
2130 | ;;; byte-opt.el ends here |