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comparison lisp/byte-optimize.el @ 428:3ecd8885ac67 r21-2-22
Import from CVS: tag r21-2-22
| author | cvs |
|---|---|
| date | Mon, 13 Aug 2007 11:28:15 +0200 |
| parents | |
| children | 9d177e8d4150 |
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| 427:0a0253eac470 | 428:3ecd8885ac67 |
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| 1 ;;; byte-optimize.el --- the optimization passes of the emacs-lisp byte compiler. | |
| 2 | |
| 3 ;;; Copyright (c) 1991, 1994 Free Software Foundation, Inc. | |
| 4 | |
| 5 ;; Author: Jamie Zawinski <jwz@jwz.org> | |
| 6 ;; Hallvard Furuseth <hbf@ulrik.uio.no> | |
| 7 ;; Keywords: internal | |
| 8 | |
| 9 ;; This file is part of XEmacs. | |
| 10 | |
| 11 ;; XEmacs is free software; you can redistribute it and/or modify it | |
| 12 ;; under the terms of the GNU General Public License as published by | |
| 13 ;; the Free Software Foundation; either version 2, or (at your option) | |
| 14 ;; any later version. | |
| 15 | |
| 16 ;; XEmacs is distributed in the hope that it will be useful, but | |
| 17 ;; WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
| 19 ;; General Public License for more details. | |
| 20 | |
| 21 ;; You should have received a copy of the GNU General Public License | |
| 22 ;; along with XEmacs; see the file COPYING. If not, write to the | |
| 23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
| 24 ;; Boston, MA 02111-1307, USA. | |
| 25 | |
| 26 ;;; Synched up with: FSF 19.30. | |
| 27 | |
| 28 ;;; Commentary: | |
| 29 | |
| 30 ;; ======================================================================== | |
| 31 ;; "No matter how hard you try, you can't make a racehorse out of a pig. | |
| 32 ;; You can, however, make a faster pig." | |
| 33 ;; | |
| 34 ;; Or, to put it another way, the emacs byte compiler is a VW Bug. This code | |
| 35 ;; makes it be a VW Bug with fuel injection and a turbocharger... You're | |
| 36 ;; still not going to make it go faster than 70 mph, but it might be easier | |
| 37 ;; to get it there. | |
| 38 ;; | |
| 39 | |
| 40 ;; TO DO: | |
| 41 ;; | |
| 42 ;; (apply #'(lambda (x &rest y) ...) 1 (foo)) | |
| 43 ;; | |
| 44 ;; maintain a list of functions known not to access any global variables | |
| 45 ;; (actually, give them a 'dynamically-safe property) and then | |
| 46 ;; (let ( v1 v2 ... vM vN ) <...dynamically-safe...> ) ==> | |
| 47 ;; (let ( v1 v2 ... vM ) vN <...dynamically-safe...> ) | |
| 48 ;; by recursing on this, we might be able to eliminate the entire let. | |
| 49 ;; However certain variables should never have their bindings optimized | |
| 50 ;; away, because they affect everything. | |
| 51 ;; (put 'debug-on-error 'binding-is-magic t) | |
| 52 ;; (put 'debug-on-abort 'binding-is-magic t) | |
| 53 ;; (put 'debug-on-next-call 'binding-is-magic t) | |
| 54 ;; (put 'mocklisp-arguments 'binding-is-magic t) | |
| 55 ;; (put 'inhibit-quit 'binding-is-magic t) | |
| 56 ;; (put 'quit-flag 'binding-is-magic t) | |
| 57 ;; (put 't 'binding-is-magic t) | |
| 58 ;; (put 'nil 'binding-is-magic t) | |
| 59 ;; possibly also | |
| 60 ;; (put 'gc-cons-threshold 'binding-is-magic t) | |
| 61 ;; (put 'track-mouse 'binding-is-magic t) | |
| 62 ;; others? | |
| 63 ;; | |
| 64 ;; Simple defsubsts often produce forms like | |
| 65 ;; (let ((v1 (f1)) (v2 (f2)) ...) | |
| 66 ;; (FN v1 v2 ...)) | |
| 67 ;; It would be nice if we could optimize this to | |
| 68 ;; (FN (f1) (f2) ...) | |
| 69 ;; but we can't unless FN is dynamically-safe (it might be dynamically | |
| 70 ;; referring to the bindings that the lambda arglist established.) | |
| 71 ;; One of the uncountable lossages introduced by dynamic scope... | |
| 72 ;; | |
| 73 ;; Maybe there should be a control-structure that says "turn on | |
| 74 ;; fast-and-loose type-assumptive optimizations here." Then when | |
| 75 ;; we see a form like (car foo) we can from then on assume that | |
| 76 ;; the variable foo is of type cons, and optimize based on that. | |
| 77 ;; But, this won't win much because of (you guessed it) dynamic | |
| 78 ;; scope. Anything down the stack could change the value. | |
| 79 ;; (Another reason it doesn't work is that it is perfectly valid | |
| 80 ;; to call car with a null argument.) A better approach might | |
| 81 ;; be to allow type-specification of the form | |
| 82 ;; (put 'foo 'arg-types '(float (list integer) dynamic)) | |
| 83 ;; (put 'foo 'result-type 'bool) | |
| 84 ;; It should be possible to have these types checked to a certain | |
| 85 ;; degree. | |
| 86 ;; | |
| 87 ;; collapse common subexpressions | |
| 88 ;; | |
| 89 ;; It would be nice if redundant sequences could be factored out as well, | |
| 90 ;; when they are known to have no side-effects: | |
| 91 ;; (list (+ a b c) (+ a b c)) --> a b add c add dup list-2 | |
| 92 ;; but beware of traps like | |
| 93 ;; (cons (list x y) (list x y)) | |
| 94 ;; | |
| 95 ;; Tail-recursion elimination is not really possible in Emacs Lisp. | |
| 96 ;; Tail-recursion elimination is almost always impossible when all variables | |
| 97 ;; have dynamic scope, but given that the "return" byteop requires the | |
| 98 ;; binding stack to be empty (rather than emptying it itself), there can be | |
| 99 ;; no truly tail-recursive Emacs Lisp functions that take any arguments or | |
| 100 ;; make any bindings. | |
| 101 ;; | |
| 102 ;; Here is an example of an Emacs Lisp function which could safely be | |
| 103 ;; byte-compiled tail-recursively: | |
| 104 ;; | |
| 105 ;; (defun tail-map (fn list) | |
| 106 ;; (cond (list | |
| 107 ;; (funcall fn (car list)) | |
| 108 ;; (tail-map fn (cdr list))))) | |
| 109 ;; | |
| 110 ;; However, if there was even a single let-binding around the COND, | |
| 111 ;; it could not be byte-compiled, because there would be an "unbind" | |
| 112 ;; byte-op between the final "call" and "return." Adding a | |
| 113 ;; Bunbind_all byteop would fix this. | |
| 114 ;; | |
| 115 ;; (defun foo (x y z) ... (foo a b c)) | |
| 116 ;; ... (const foo) (varref a) (varref b) (varref c) (call 3) END: (return) | |
| 117 ;; ... (varref a) (varbind x) (varref b) (varbind y) (varref c) (varbind z) (goto 0) END: (unbind-all) (return) | |
| 118 ;; ... (varref a) (varset x) (varref b) (varset y) (varref c) (varset z) (goto 0) END: (return) | |
| 119 ;; | |
| 120 ;; this also can be considered tail recursion: | |
| 121 ;; | |
| 122 ;; ... (const foo) (varref a) (call 1) (goto X) ... X: (return) | |
| 123 ;; could generalize this by doing the optimization | |
| 124 ;; (goto X) ... X: (return) --> (return) | |
| 125 ;; | |
| 126 ;; But this doesn't solve all of the problems: although by doing tail- | |
| 127 ;; recursion elimination in this way, the call-stack does not grow, the | |
| 128 ;; binding-stack would grow with each recursive step, and would eventually | |
| 129 ;; overflow. I don't believe there is any way around this without lexical | |
| 130 ;; scope. | |
| 131 ;; | |
| 132 ;; Wouldn't it be nice if Emacs Lisp had lexical scope. | |
| 133 ;; | |
| 134 ;; Idea: the form (lexical-scope) in a file means that the file may be | |
| 135 ;; compiled lexically. This proclamation is file-local. Then, within | |
| 136 ;; that file, "let" would establish lexical bindings, and "let-dynamic" | |
| 137 ;; would do things the old way. (Or we could use CL "declare" forms.) | |
| 138 ;; We'd have to notice defvars and defconsts, since those variables should | |
| 139 ;; always be dynamic, and attempting to do a lexical binding of them | |
| 140 ;; should simply do a dynamic binding instead. | |
| 141 ;; But! We need to know about variables that were not necessarily defvarred | |
| 142 ;; in the file being compiled (doing a boundp check isn't good enough.) | |
| 143 ;; Fdefvar() would have to be modified to add something to the plist. | |
| 144 ;; | |
| 145 ;; A major disadvantage of this scheme is that the interpreter and compiler | |
| 146 ;; would have different semantics for files compiled with (dynamic-scope). | |
| 147 ;; Since this would be a file-local optimization, there would be no way to | |
| 148 ;; modify the interpreter to obey this (unless the loader was hacked | |
| 149 ;; in some grody way, but that's a really bad idea.) | |
| 150 ;; | |
| 151 ;; HA! RMS removed the following paragraph from his version of | |
| 152 ;; byte-optimize.el. | |
| 153 ;; | |
| 154 ;; Really the Right Thing is to make lexical scope the default across | |
| 155 ;; the board, in the interpreter and compiler, and just FIX all of | |
| 156 ;; the code that relies on dynamic scope of non-defvarred variables. | |
| 157 | |
| 158 ;; Other things to consider: | |
| 159 | |
| 160 ;; Associative math should recognize subcalls to identical function: | |
| 161 ;;(disassemble #'(lambda (x) (+ (+ (foo) 1) (+ (bar) 2)))) | |
| 162 ;; This should generate the same as (1+ x) and (1- x) | |
| 163 | |
| 164 ;;(disassemble #'(lambda (x) (cons (+ x 1) (- x 1)))) | |
| 165 ;; An awful lot of functions always return a non-nil value. If they're | |
| 166 ;; error free also they may act as true-constants. | |
| 167 | |
| 168 ;;(disassemble #'(lambda (x) (and (point) (foo)))) | |
| 169 ;; When | |
| 170 ;; - all but one arguments to a function are constant | |
| 171 ;; - the non-constant argument is an if-expression (cond-expression?) | |
| 172 ;; then the outer function can be distributed. If the guarding | |
| 173 ;; condition is side-effect-free [assignment-free] then the other | |
| 174 ;; arguments may be any expressions. Since, however, the code size | |
| 175 ;; can increase this way they should be "simple". Compare: | |
| 176 | |
| 177 ;;(disassemble #'(lambda (x) (eq (if (point) 'a 'b) 'c))) | |
| 178 ;;(disassemble #'(lambda (x) (if (point) (eq 'a 'c) (eq 'b 'c)))) | |
| 179 | |
| 180 ;; (car (cons A B)) -> (progn B A) | |
| 181 ;;(disassemble #'(lambda (x) (car (cons (foo) 42)))) | |
| 182 | |
| 183 ;; (cdr (cons A B)) -> (progn A B) | |
| 184 ;;(disassemble #'(lambda (x) (cdr (cons 42 (foo))))) | |
| 185 | |
| 186 ;; (car (list A B ...)) -> (progn B ... A) | |
| 187 ;;(disassemble #'(lambda (x) (car (list (foo) 42 (bar))))) | |
| 188 | |
| 189 ;; (cdr (list A B ...)) -> (progn A (list B ...)) | |
| 190 ;;(disassemble #'(lambda (x) (cdr (list 42 (foo) (bar))))) | |
| 191 | |
| 192 | |
| 193 ;;; Code: | |
| 194 | |
| 195 (require 'byte-compile "bytecomp") | |
| 196 | |
| 197 (defun byte-compile-log-lap-1 (format &rest args) | |
| 198 (if (aref byte-code-vector 0) | |
| 199 (error "The old version of the disassembler is loaded. Reload new-bytecomp as well.")) | |
| 200 (byte-compile-log-1 | |
| 201 (apply 'format format | |
| 202 (let (c a) | |
| 203 (mapcar | |
| 204 #'(lambda (arg) | |
| 205 (if (not (consp arg)) | |
| 206 (if (and (symbolp arg) | |
| 207 (string-match "^byte-" (symbol-name arg))) | |
| 208 (intern (substring (symbol-name arg) 5)) | |
| 209 arg) | |
| 210 (if (integerp (setq c (car arg))) | |
| 211 (error "non-symbolic byte-op %s" c)) | |
| 212 (if (eq c 'TAG) | |
| 213 (setq c arg) | |
| 214 (setq a (cond ((memq c byte-goto-ops) | |
| 215 (car (cdr (cdr arg)))) | |
| 216 ((memq c byte-constref-ops) | |
| 217 (car (cdr arg))) | |
| 218 (t (cdr arg)))) | |
| 219 (setq c (symbol-name c)) | |
| 220 (if (string-match "^byte-." c) | |
| 221 (setq c (intern (substring c 5))))) | |
| 222 (if (eq c 'constant) (setq c 'const)) | |
| 223 (if (and (eq (cdr arg) 0) | |
| 224 (not (memq c '(unbind call const)))) | |
| 225 c | |
| 226 (format "(%s %s)" c a)))) | |
| 227 args))))) | |
| 228 | |
| 229 (defmacro byte-compile-log-lap (format-string &rest args) | |
| 230 (list 'and | |
| 231 '(memq byte-optimize-log '(t byte)) | |
| 232 (cons 'byte-compile-log-lap-1 | |
| 233 (cons format-string args)))) | |
| 234 | |
| 235 | |
| 236 ;;; byte-compile optimizers to support inlining | |
| 237 | |
| 238 (put 'inline 'byte-optimizer 'byte-optimize-inline-handler) | |
| 239 | |
| 240 (defun byte-optimize-inline-handler (form) | |
| 241 "byte-optimize-handler for the `inline' special-form." | |
| 242 (cons | |
| 243 'progn | |
| 244 (mapcar | |
| 245 #'(lambda (sexp) | |
| 246 (let ((fn (car-safe sexp))) | |
| 247 (if (and (symbolp fn) | |
| 248 (or (cdr (assq fn byte-compile-function-environment)) | |
| 249 (and (fboundp fn) | |
| 250 (not (or (cdr (assq fn byte-compile-macro-environment)) | |
| 251 (and (consp (setq fn (symbol-function fn))) | |
| 252 (eq (car fn) 'macro)) | |
| 253 (subrp fn)))))) | |
| 254 (byte-compile-inline-expand sexp) | |
| 255 sexp))) | |
| 256 (cdr form)))) | |
| 257 | |
| 258 | |
| 259 ;; Splice the given lap code into the current instruction stream. | |
| 260 ;; If it has any labels in it, you're responsible for making sure there | |
| 261 ;; are no collisions, and that byte-compile-tag-number is reasonable | |
| 262 ;; after this is spliced in. The provided list is destroyed. | |
| 263 (defun byte-inline-lapcode (lap) | |
| 264 (setq byte-compile-output (nconc (nreverse lap) byte-compile-output))) | |
| 265 | |
| 266 | |
| 267 (defun byte-compile-inline-expand (form) | |
| 268 (let* ((name (car form)) | |
| 269 (fn (or (cdr (assq name byte-compile-function-environment)) | |
| 270 (and (fboundp name) (symbol-function name))))) | |
| 271 (if (null fn) | |
| 272 (progn | |
| 273 (byte-compile-warn "attempt to inline %s before it was defined" name) | |
| 274 form) | |
| 275 ;; else | |
| 276 (if (and (consp fn) (eq (car fn) 'autoload)) | |
| 277 (progn | |
| 278 (load (nth 1 fn)) | |
| 279 (setq fn (or (cdr (assq name byte-compile-function-environment)) | |
| 280 (and (fboundp name) (symbol-function name)))))) | |
| 281 (if (and (consp fn) (eq (car fn) 'autoload)) | |
| 282 (error "file \"%s\" didn't define \"%s\"" (nth 1 fn) name)) | |
| 283 (if (symbolp fn) | |
| 284 (byte-compile-inline-expand (cons fn (cdr form))) | |
| 285 (if (compiled-function-p fn) | |
| 286 (progn | |
| 287 (fetch-bytecode fn) | |
| 288 (cons (list 'lambda (compiled-function-arglist fn) | |
| 289 (list 'byte-code | |
| 290 (compiled-function-instructions fn) | |
| 291 (compiled-function-constants fn) | |
| 292 (compiled-function-stack-depth fn))) | |
| 293 (cdr form))) | |
| 294 (if (not (eq (car fn) 'lambda)) (error "%s is not a lambda" name)) | |
| 295 (cons fn (cdr form))))))) | |
| 296 | |
| 297 ;;; ((lambda ...) ...) | |
| 298 ;;; | |
| 299 (defun byte-compile-unfold-lambda (form &optional name) | |
| 300 (or name (setq name "anonymous lambda")) | |
| 301 (let ((lambda (car form)) | |
| 302 (values (cdr form))) | |
| 303 (if (compiled-function-p lambda) | |
| 304 (setq lambda (list 'lambda (compiled-function-arglist lambda) | |
| 305 (list 'byte-code | |
| 306 (compiled-function-instructions lambda) | |
| 307 (compiled-function-constants lambda) | |
| 308 (compiled-function-stack-depth lambda))))) | |
| 309 (let ((arglist (nth 1 lambda)) | |
| 310 (body (cdr (cdr lambda))) | |
| 311 optionalp restp | |
| 312 bindings) | |
| 313 (if (and (stringp (car body)) (cdr body)) | |
| 314 (setq body (cdr body))) | |
| 315 (if (and (consp (car body)) (eq 'interactive (car (car body)))) | |
| 316 (setq body (cdr body))) | |
| 317 (while arglist | |
| 318 (cond ((eq (car arglist) '&optional) | |
| 319 ;; ok, I'll let this slide because funcall_lambda() does... | |
| 320 ;; (if optionalp (error "multiple &optional keywords in %s" name)) | |
| 321 (if restp (error "&optional found after &rest in %s" name)) | |
| 322 (if (null (cdr arglist)) | |
| 323 (error "nothing after &optional in %s" name)) | |
| 324 (setq optionalp t)) | |
| 325 ((eq (car arglist) '&rest) | |
| 326 ;; ...but it is by no stretch of the imagination a reasonable | |
| 327 ;; thing that funcall_lambda() allows (&rest x y) and | |
| 328 ;; (&rest x &optional y) in arglists. | |
| 329 (if (null (cdr arglist)) | |
| 330 (error "nothing after &rest in %s" name)) | |
| 331 (if (cdr (cdr arglist)) | |
| 332 (error "multiple vars after &rest in %s" name)) | |
| 333 (setq restp t)) | |
| 334 (restp | |
| 335 (setq bindings (cons (list (car arglist) | |
| 336 (and values (cons 'list values))) | |
| 337 bindings) | |
| 338 values nil)) | |
| 339 ((and (not optionalp) (null values)) | |
| 340 (byte-compile-warn "attempt to open-code %s with too few arguments" name) | |
| 341 (setq arglist nil values 'too-few)) | |
| 342 (t | |
| 343 (setq bindings (cons (list (car arglist) (car values)) | |
| 344 bindings) | |
| 345 values (cdr values)))) | |
| 346 (setq arglist (cdr arglist))) | |
| 347 (if values | |
| 348 (progn | |
| 349 (or (eq values 'too-few) | |
| 350 (byte-compile-warn | |
| 351 "attempt to open-code %s with too many arguments" name)) | |
| 352 form) | |
| 353 (let ((newform | |
| 354 (if bindings | |
| 355 (cons 'let (cons (nreverse bindings) body)) | |
| 356 (cons 'progn body)))) | |
| 357 (byte-compile-log " %s\t==>\t%s" form newform) | |
| 358 newform))))) | |
| 359 | |
| 360 | |
| 361 ;;; implementing source-level optimizers | |
| 362 | |
| 363 (defun byte-optimize-form-code-walker (form for-effect) | |
| 364 ;; | |
| 365 ;; For normal function calls, We can just mapcar the optimizer the cdr. But | |
| 366 ;; we need to have special knowledge of the syntax of the special forms | |
| 367 ;; like let and defun (that's why they're special forms :-). (Actually, | |
| 368 ;; the important aspect is that they are subrs that don't evaluate all of | |
| 369 ;; their args.) | |
| 370 ;; | |
| 371 (let ((fn (car-safe form)) | |
| 372 tmp) | |
| 373 (cond ((not (consp form)) | |
| 374 (if (not (and for-effect | |
| 375 (or byte-compile-delete-errors | |
| 376 (not (symbolp form)) | |
| 377 (eq form t)))) | |
| 378 form)) | |
| 379 ((eq fn 'quote) | |
| 380 (if (cdr (cdr form)) | |
| 381 (byte-compile-warn "malformed quote form: %s" | |
| 382 (prin1-to-string form))) | |
| 383 ;; map (quote nil) to nil to simplify optimizer logic. | |
| 384 ;; map quoted constants to nil if for-effect (just because). | |
| 385 (and (nth 1 form) | |
| 386 (not for-effect) | |
| 387 form)) | |
| 388 ((or (compiled-function-p fn) | |
| 389 (eq 'lambda (car-safe fn))) | |
| 390 (byte-compile-unfold-lambda form)) | |
| 391 ((memq fn '(let let*)) | |
| 392 ;; recursively enter the optimizer for the bindings and body | |
| 393 ;; of a let or let*. This for depth-firstness: forms that | |
| 394 ;; are more deeply nested are optimized first. | |
| 395 (cons fn | |
| 396 (cons | |
| 397 (mapcar | |
| 398 #'(lambda (binding) | |
| 399 (if (symbolp binding) | |
| 400 binding | |
| 401 (if (cdr (cdr binding)) | |
| 402 (byte-compile-warn "malformed let binding: %s" | |
| 403 (prin1-to-string binding))) | |
| 404 (list (car binding) | |
| 405 (byte-optimize-form (nth 1 binding) nil)))) | |
| 406 (nth 1 form)) | |
| 407 (byte-optimize-body (cdr (cdr form)) for-effect)))) | |
| 408 ((eq fn 'cond) | |
| 409 (cons fn | |
| 410 (mapcar | |
| 411 #'(lambda (clause) | |
| 412 (if (consp clause) | |
| 413 (cons | |
| 414 (byte-optimize-form (car clause) nil) | |
| 415 (byte-optimize-body (cdr clause) for-effect)) | |
| 416 (byte-compile-warn "malformed cond form: %s" | |
| 417 (prin1-to-string clause)) | |
| 418 clause)) | |
| 419 (cdr form)))) | |
| 420 ((eq fn 'progn) | |
| 421 ;; as an extra added bonus, this simplifies (progn <x>) --> <x> | |
| 422 (if (cdr (cdr form)) | |
| 423 (progn | |
| 424 (setq tmp (byte-optimize-body (cdr form) for-effect)) | |
| 425 (if (cdr tmp) (cons 'progn tmp) (car tmp))) | |
| 426 (byte-optimize-form (nth 1 form) for-effect))) | |
| 427 ((eq fn 'prog1) | |
| 428 (if (cdr (cdr form)) | |
| 429 (cons 'prog1 | |
| 430 (cons (byte-optimize-form (nth 1 form) for-effect) | |
| 431 (byte-optimize-body (cdr (cdr form)) t))) | |
| 432 (byte-optimize-form (nth 1 form) for-effect))) | |
| 433 ((eq fn 'prog2) | |
| 434 (cons 'prog2 | |
| 435 (cons (byte-optimize-form (nth 1 form) t) | |
| 436 (cons (byte-optimize-form (nth 2 form) for-effect) | |
| 437 (byte-optimize-body (cdr (cdr (cdr form))) t))))) | |
| 438 | |
| 439 ((memq fn '(save-excursion save-restriction save-current-buffer)) | |
| 440 ;; those subrs which have an implicit progn; it's not quite good | |
| 441 ;; enough to treat these like normal function calls. | |
| 442 ;; This can turn (save-excursion ...) into (save-excursion) which | |
| 443 ;; will be optimized away in the lap-optimize pass. | |
| 444 (cons fn (byte-optimize-body (cdr form) for-effect))) | |
| 445 | |
| 446 ((eq fn 'with-output-to-temp-buffer) | |
| 447 ;; this is just like the above, except for the first argument. | |
| 448 (cons fn | |
| 449 (cons | |
| 450 (byte-optimize-form (nth 1 form) nil) | |
| 451 (byte-optimize-body (cdr (cdr form)) for-effect)))) | |
| 452 | |
| 453 ((eq fn 'if) | |
| 454 (cons fn | |
| 455 (cons (byte-optimize-form (nth 1 form) nil) | |
| 456 (cons | |
| 457 (byte-optimize-form (nth 2 form) for-effect) | |
| 458 (byte-optimize-body (nthcdr 3 form) for-effect))))) | |
| 459 | |
| 460 ((memq fn '(and or)) ; remember, and/or are control structures. | |
| 461 ;; take forms off the back until we can't any more. | |
| 462 ;; In the future it could conceivably be a problem that the | |
| 463 ;; subexpressions of these forms are optimized in the reverse | |
| 464 ;; order, but it's ok for now. | |
| 465 (if for-effect | |
| 466 (let ((backwards (reverse (cdr form)))) | |
| 467 (while (and backwards | |
| 468 (null (setcar backwards | |
| 469 (byte-optimize-form (car backwards) | |
| 470 for-effect)))) | |
| 471 (setq backwards (cdr backwards))) | |
| 472 (if (and (cdr form) (null backwards)) | |
| 473 (byte-compile-log | |
| 474 " all subforms of %s called for effect; deleted" form)) | |
| 475 (and backwards | |
| 476 (cons fn (nreverse backwards)))) | |
| 477 (cons fn (mapcar 'byte-optimize-form (cdr form))))) | |
| 478 | |
| 479 ((eq fn 'interactive) | |
| 480 (byte-compile-warn "misplaced interactive spec: %s" | |
| 481 (prin1-to-string form)) | |
| 482 nil) | |
| 483 | |
| 484 ((memq fn '(defun defmacro function | |
| 485 condition-case save-window-excursion)) | |
| 486 ;; These forms are compiled as constants or by breaking out | |
| 487 ;; all the subexpressions and compiling them separately. | |
| 488 form) | |
| 489 | |
| 490 ((eq fn 'unwind-protect) | |
| 491 ;; the "protected" part of an unwind-protect is compiled (and thus | |
| 492 ;; optimized) as a top-level form, so don't do it here. But the | |
| 493 ;; non-protected part has the same for-effect status as the | |
| 494 ;; unwind-protect itself. (The protected part is always for effect, | |
| 495 ;; but that isn't handled properly yet.) | |
| 496 (cons fn | |
| 497 (cons (byte-optimize-form (nth 1 form) for-effect) | |
| 498 (cdr (cdr form))))) | |
| 499 | |
| 500 ((eq fn 'catch) | |
| 501 ;; the body of a catch is compiled (and thus optimized) as a | |
| 502 ;; top-level form, so don't do it here. The tag is never | |
| 503 ;; for-effect. The body should have the same for-effect status | |
| 504 ;; as the catch form itself, but that isn't handled properly yet. | |
| 505 (cons fn | |
| 506 (cons (byte-optimize-form (nth 1 form) nil) | |
| 507 (cdr (cdr form))))) | |
| 508 | |
| 509 ;; If optimization is on, this is the only place that macros are | |
| 510 ;; expanded. If optimization is off, then macroexpansion happens | |
| 511 ;; in byte-compile-form. Otherwise, the macros are already expanded | |
| 512 ;; by the time that is reached. | |
| 513 ((not (eq form | |
| 514 (setq form (macroexpand form | |
| 515 byte-compile-macro-environment)))) | |
| 516 (byte-optimize-form form for-effect)) | |
| 517 | |
| 518 ((not (symbolp fn)) | |
| 519 (or (eq 'mocklisp (car-safe fn)) ; ha! | |
| 520 (byte-compile-warn "%s is a malformed function" | |
| 521 (prin1-to-string fn))) | |
| 522 form) | |
| 523 | |
| 524 ((and for-effect (setq tmp (get fn 'side-effect-free)) | |
| 525 (or byte-compile-delete-errors | |
| 526 (eq tmp 'error-free) | |
| 527 (progn | |
| 528 (byte-compile-warn "%s called for effect" | |
| 529 (prin1-to-string form)) | |
| 530 nil))) | |
| 531 (byte-compile-log " %s called for effect; deleted" fn) | |
| 532 ;; appending a nil here might not be necessary, but it can't hurt. | |
| 533 (byte-optimize-form | |
| 534 (cons 'progn (append (cdr form) '(nil))) t)) | |
| 535 | |
| 536 (t | |
| 537 ;; Otherwise, no args can be considered to be for-effect, | |
| 538 ;; even if the called function is for-effect, because we | |
| 539 ;; don't know anything about that function. | |
| 540 (cons fn (mapcar 'byte-optimize-form (cdr form))))))) | |
| 541 | |
| 542 | |
| 543 (defun byte-optimize-form (form &optional for-effect) | |
| 544 "The source-level pass of the optimizer." | |
| 545 ;; | |
| 546 ;; First, optimize all sub-forms of this one. | |
| 547 (setq form (byte-optimize-form-code-walker form for-effect)) | |
| 548 ;; | |
| 549 ;; After optimizing all subforms, optimize this form until it doesn't | |
| 550 ;; optimize any further. This means that some forms will be passed through | |
| 551 ;; the optimizer many times, but that's necessary to make the for-effect | |
| 552 ;; processing do as much as possible. | |
| 553 ;; | |
| 554 (let (opt new) | |
| 555 (if (and (consp form) | |
| 556 (symbolp (car form)) | |
| 557 (or (and for-effect | |
| 558 ;; we don't have any of these yet, but we might. | |
| 559 (setq opt (get (car form) 'byte-for-effect-optimizer))) | |
| 560 (setq opt (get (car form) 'byte-optimizer))) | |
| 561 (not (eq form (setq new (funcall opt form))))) | |
| 562 (progn | |
| 563 ;; (if (equal form new) (error "bogus optimizer -- %s" opt)) | |
| 564 (byte-compile-log " %s\t==>\t%s" form new) | |
| 565 (setq new (byte-optimize-form new for-effect)) | |
| 566 new) | |
| 567 form))) | |
| 568 | |
| 569 | |
| 570 (defun byte-optimize-body (forms all-for-effect) | |
| 571 ;; Optimize the cdr of a progn or implicit progn; `forms' is a list of | |
| 572 ;; forms, all but the last of which are optimized with the assumption that | |
| 573 ;; they are being called for effect. The last is for-effect as well if | |
| 574 ;; all-for-effect is true. Returns a new list of forms. | |
| 575 (let ((rest forms) | |
| 576 (result nil) | |
| 577 fe new) | |
| 578 (while rest | |
| 579 (setq fe (or all-for-effect (cdr rest))) | |
| 580 (setq new (and (car rest) (byte-optimize-form (car rest) fe))) | |
| 581 (if (or new (not fe)) | |
| 582 (setq result (cons new result))) | |
| 583 (setq rest (cdr rest))) | |
| 584 (nreverse result))) | |
| 585 | |
| 586 | |
| 587 ;;; some source-level optimizers | |
| 588 ;;; | |
| 589 ;;; when writing optimizers, be VERY careful that the optimizer returns | |
| 590 ;;; something not EQ to its argument if and ONLY if it has made a change. | |
| 591 ;;; This implies that you cannot simply destructively modify the list; | |
| 592 ;;; you must return something not EQ to it if you make an optimization. | |
| 593 ;;; | |
| 594 ;;; It is now safe to optimize code such that it introduces new bindings. | |
| 595 | |
| 596 ;; I'd like this to be a defsubst, but let's not be self-referential... | |
| 597 (defmacro byte-compile-trueconstp (form) | |
| 598 ;; Returns non-nil if FORM is a non-nil constant. | |
| 599 `(cond ((consp ,form) (eq (car ,form) 'quote)) | |
| 600 ((not (symbolp ,form))) | |
| 601 ((eq ,form t)) | |
| 602 ((keywordp ,form)))) | |
| 603 | |
| 604 ;; If the function is being called with constant numeric args, | |
| 605 ;; evaluate as much as possible at compile-time. This optimizer | |
| 606 ;; assumes that the function is associative, like + or *. | |
| 607 (defun byte-optimize-associative-math (form) | |
| 608 (let ((args nil) | |
| 609 (constants nil) | |
| 610 (rest (cdr form))) | |
| 611 (while rest | |
| 612 (if (numberp (car rest)) | |
| 613 (setq constants (cons (car rest) constants)) | |
| 614 (setq args (cons (car rest) args))) | |
| 615 (setq rest (cdr rest))) | |
| 616 (if (cdr constants) | |
| 617 (if args | |
| 618 (list (car form) | |
| 619 (apply (car form) constants) | |
| 620 (if (cdr args) | |
| 621 (cons (car form) (nreverse args)) | |
| 622 (car args))) | |
| 623 (apply (car form) constants)) | |
| 624 form))) | |
| 625 | |
| 626 ;; If the function is being called with constant numeric args, | |
| 627 ;; evaluate as much as possible at compile-time. This optimizer | |
| 628 ;; assumes that the function satisfies | |
| 629 ;; (op x1 x2 ... xn) == (op ...(op (op x1 x2) x3) ...xn) | |
| 630 ;; like - and /. | |
| 631 (defun byte-optimize-nonassociative-math (form) | |
| 632 (if (or (not (numberp (car (cdr form)))) | |
| 633 (not (numberp (car (cdr (cdr form)))))) | |
| 634 form | |
| 635 (let ((constant (car (cdr form))) | |
| 636 (rest (cdr (cdr form)))) | |
| 637 (while (numberp (car rest)) | |
| 638 (setq constant (funcall (car form) constant (car rest)) | |
| 639 rest (cdr rest))) | |
| 640 (if rest | |
| 641 (cons (car form) (cons constant rest)) | |
| 642 constant)))) | |
| 643 | |
| 644 ;;(defun byte-optimize-associative-two-args-math (form) | |
| 645 ;; (setq form (byte-optimize-associative-math form)) | |
| 646 ;; (if (consp form) | |
| 647 ;; (byte-optimize-two-args-left form) | |
| 648 ;; form)) | |
| 649 | |
| 650 ;;(defun byte-optimize-nonassociative-two-args-math (form) | |
| 651 ;; (setq form (byte-optimize-nonassociative-math form)) | |
| 652 ;; (if (consp form) | |
| 653 ;; (byte-optimize-two-args-right form) | |
| 654 ;; form)) | |
| 655 | |
| 656 ;; jwz: (byte-optimize-approx-equal 0.0 0.0) was returning nil | |
| 657 ;; in xemacs 19.15 because it used < instead of <=. | |
| 658 (defun byte-optimize-approx-equal (x y) | |
| 659 (<= (* (abs (- x y)) 100) (abs (+ x y)))) | |
| 660 | |
| 661 ;; Collect all the constants from FORM, after the STARTth arg, | |
| 662 ;; and apply FUN to them to make one argument at the end. | |
| 663 ;; For functions that can handle floats, that optimization | |
| 664 ;; can be incorrect because reordering can cause an overflow | |
| 665 ;; that would otherwise be avoided by encountering an arg that is a float. | |
| 666 ;; We avoid this problem by (1) not moving float constants and | |
| 667 ;; (2) not moving anything if it would cause an overflow. | |
| 668 (defun byte-optimize-delay-constants-math (form start fun) | |
| 669 ;; Merge all FORM's constants from number START, call FUN on them | |
| 670 ;; and put the result at the end. | |
| 671 (let ((rest (nthcdr (1- start) form)) | |
| 672 (orig form) | |
| 673 ;; t means we must check for overflow. | |
| 674 (overflow (memq fun '(+ *)))) | |
| 675 (while (cdr (setq rest (cdr rest))) | |
| 676 (if (integerp (car rest)) | |
| 677 (let (constants) | |
| 678 (setq form (copy-sequence form) | |
| 679 rest (nthcdr (1- start) form)) | |
| 680 (while (setq rest (cdr rest)) | |
| 681 (cond ((integerp (car rest)) | |
| 682 (setq constants (cons (car rest) constants)) | |
| 683 (setcar rest nil)))) | |
| 684 ;; If necessary, check now for overflow | |
| 685 ;; that might be caused by reordering. | |
| 686 (if (and overflow | |
| 687 ;; We have overflow if the result of doing the arithmetic | |
| 688 ;; on floats is not even close to the result | |
| 689 ;; of doing it on integers. | |
| 690 (not (byte-optimize-approx-equal | |
| 691 (apply fun (mapcar 'float constants)) | |
| 692 (float (apply fun constants))))) | |
| 693 (setq form orig) | |
| 694 (setq form (nconc (delq nil form) | |
| 695 (list (apply fun (nreverse constants))))))))) | |
| 696 form)) | |
| 697 | |
| 698 (defun byte-optimize-plus (form) | |
| 699 (setq form (byte-optimize-delay-constants-math form 1 '+)) | |
| 700 (if (memq 0 form) (setq form (delq 0 (copy-sequence form)))) | |
| 701 ;;(setq form (byte-optimize-associative-two-args-math form)) | |
| 702 (cond ((null (cdr form)) | |
| 703 (condition-case () | |
| 704 (eval form) | |
| 705 (error form))) | |
| 706 | |
| 707 ;; `add1' and `sub1' are a marginally fewer instructions | |
| 708 ;; than `plus' and `minus', so use them when possible. | |
| 709 ((and (null (nthcdr 3 form)) | |
| 710 (eq (nth 2 form) 1)) | |
| 711 (list '1+ (nth 1 form))) ; (+ x 1) --> (1+ x) | |
| 712 ((and (null (nthcdr 3 form)) | |
| 713 (eq (nth 1 form) 1)) | |
| 714 (list '1+ (nth 2 form))) ; (+ 1 x) --> (1+ x) | |
| 715 ((and (null (nthcdr 3 form)) | |
| 716 (eq (nth 2 form) -1)) | |
| 717 (list '1- (nth 1 form))) ; (+ x -1) --> (1- x) | |
| 718 ((and (null (nthcdr 3 form)) | |
| 719 (eq (nth 1 form) -1)) | |
| 720 (list '1- (nth 2 form))) ; (+ -1 x) --> (1- x) | |
| 721 | |
| 722 ;;; It is not safe to delete the function entirely | |
| 723 ;;; (actually, it would be safe if we know the sole arg | |
| 724 ;;; is not a marker). | |
| 725 ;; ((null (cdr (cdr form))) (nth 1 form)) | |
| 726 (t form))) | |
| 727 | |
| 728 (defun byte-optimize-minus (form) | |
| 729 ;; Put constants at the end, except the last constant. | |
| 730 (setq form (byte-optimize-delay-constants-math form 2 '+)) | |
| 731 ;; Now only first and last element can be a number. | |
| 732 (let ((last (car (reverse (nthcdr 3 form))))) | |
| 733 (cond ((eq 0 last) | |
| 734 ;; (- x y ... 0) --> (- x y ...) | |
| 735 (setq form (copy-sequence form)) | |
| 736 (setcdr (cdr (cdr form)) (delq 0 (nthcdr 3 form)))) | |
| 737 ;; If form is (- CONST foo... CONST), merge first and last. | |
| 738 ((and (numberp (nth 1 form)) | |
| 739 (numberp last)) | |
| 740 (setq form (nconc (list '- (- (nth 1 form) last) (nth 2 form)) | |
| 741 (delq last (copy-sequence (nthcdr 3 form)))))))) | |
| 742 (setq form | |
| 743 ;;; It is not safe to delete the function entirely | |
| 744 ;;; (actually, it would be safe if we know the sole arg | |
| 745 ;;; is not a marker). | |
| 746 ;;; (if (eq (nth 2 form) 0) | |
| 747 ;;; (nth 1 form) ; (- x 0) --> x | |
| 748 (byte-optimize-predicate | |
| 749 (if (and (null (cdr (cdr (cdr form)))) | |
| 750 (eq (nth 1 form) 0)) ; (- 0 x) --> (- x) | |
| 751 (cons (car form) (cdr (cdr form))) | |
| 752 form)) | |
| 753 ;;; ) | |
| 754 ) | |
| 755 | |
| 756 ;; `add1' and `sub1' are a marginally fewer instructions than `plus' | |
| 757 ;; and `minus', so use them when possible. | |
| 758 (cond ((and (null (nthcdr 3 form)) | |
| 759 (eq (nth 2 form) 1)) | |
| 760 (list '1- (nth 1 form))) ; (- x 1) --> (1- x) | |
| 761 ((and (null (nthcdr 3 form)) | |
| 762 (eq (nth 2 form) -1)) | |
| 763 (list '1+ (nth 1 form))) ; (- x -1) --> (1+ x) | |
| 764 (t | |
| 765 form)) | |
| 766 ) | |
| 767 | |
| 768 (defun byte-optimize-multiply (form) | |
| 769 (setq form (byte-optimize-delay-constants-math form 1 '*)) | |
| 770 ;; If there is a constant in FORM, it is now the last element. | |
| 771 (cond ((null (cdr form)) 1) | |
| 772 ;;; It is not safe to delete the function entirely | |
| 773 ;;; (actually, it would be safe if we know the sole arg | |
| 774 ;;; is not a marker or if it appears in other arithmetic). | |
| 775 ;;; ((null (cdr (cdr form))) (nth 1 form)) | |
| 776 ((let ((last (car (reverse form)))) | |
| 777 (cond ((eq 0 last) (cons 'progn (cdr form))) | |
| 778 ((eq 1 last) (delq 1 (copy-sequence form))) | |
| 779 ((eq -1 last) (list '- (delq -1 (copy-sequence form)))) | |
| 780 ((and (eq 2 last) | |
| 781 (memq t (mapcar 'symbolp (cdr form)))) | |
| 782 (prog1 (setq form (delq 2 (copy-sequence form))) | |
| 783 (while (not (symbolp (car (setq form (cdr form)))))) | |
| 784 (setcar form (list '+ (car form) (car form))))) | |
| 785 (form)))))) | |
| 786 | |
| 787 (defsubst byte-compile-butlast (form) | |
| 788 (nreverse (cdr (reverse form)))) | |
| 789 | |
| 790 (defun byte-optimize-divide (form) | |
| 791 (setq form (byte-optimize-delay-constants-math form 2 '*)) | |
| 792 (let ((last (car (reverse (cdr (cdr form)))))) | |
| 793 (if (numberp last) | |
| 794 (cond ((= (length form) 3) | |
| 795 (if (and (numberp (nth 1 form)) | |
| 796 (not (zerop last)) | |
| 797 (condition-case nil | |
| 798 (/ (nth 1 form) last) | |
| 799 (error nil))) | |
| 800 (setq form (list 'progn (/ (nth 1 form) last))))) | |
| 801 ((= last 1) | |
| 802 (setq form (byte-compile-butlast form))) | |
| 803 ((numberp (nth 1 form)) | |
| 804 (setq form (cons (car form) | |
| 805 (cons (/ (nth 1 form) last) | |
| 806 (byte-compile-butlast (cdr (cdr form))))) | |
| 807 last nil)))) | |
| 808 (cond | |
| 809 ;;; ((null (cdr (cdr form))) | |
| 810 ;;; (nth 1 form)) | |
| 811 ((eq (nth 1 form) 0) | |
| 812 (append '(progn) (cdr (cdr form)) '(0))) | |
| 813 ((eq last -1) | |
| 814 (list '- (if (nthcdr 3 form) | |
| 815 (byte-compile-butlast form) | |
| 816 (nth 1 form)))) | |
| 817 (form)))) | |
| 818 | |
| 819 (defun byte-optimize-logmumble (form) | |
| 820 (setq form (byte-optimize-delay-constants-math form 1 (car form))) | |
| 821 (byte-optimize-predicate | |
| 822 (cond ((memq 0 form) | |
| 823 (setq form (if (eq (car form) 'logand) | |
| 824 (cons 'progn (cdr form)) | |
| 825 (delq 0 (copy-sequence form))))) | |
| 826 ((and (eq (car-safe form) 'logior) | |
| 827 (memq -1 form)) | |
| 828 (cons 'progn (cdr form))) | |
| 829 (form)))) | |
| 830 | |
| 831 | |
| 832 (defun byte-optimize-binary-predicate (form) | |
| 833 (if (byte-compile-constp (nth 1 form)) | |
| 834 (if (byte-compile-constp (nth 2 form)) | |
| 835 (condition-case () | |
| 836 (list 'quote (eval form)) | |
| 837 (error form)) | |
| 838 ;; This can enable some lapcode optimizations. | |
| 839 (list (car form) (nth 2 form) (nth 1 form))) | |
| 840 form)) | |
| 841 | |
| 842 (defun byte-optimize-predicate (form) | |
| 843 (let ((ok t) | |
| 844 (rest (cdr form))) | |
| 845 (while (and rest ok) | |
| 846 (setq ok (byte-compile-constp (car rest)) | |
| 847 rest (cdr rest))) | |
| 848 (if ok | |
| 849 (condition-case () | |
| 850 (list 'quote (eval form)) | |
| 851 (error form)) | |
| 852 form))) | |
| 853 | |
| 854 (defun byte-optimize-identity (form) | |
| 855 (if (and (cdr form) (null (cdr (cdr form)))) | |
| 856 (nth 1 form) | |
| 857 (byte-compile-warn "identity called with %d arg%s, but requires 1" | |
| 858 (length (cdr form)) | |
| 859 (if (= 1 (length (cdr form))) "" "s")) | |
| 860 form)) | |
| 861 | |
| 862 (put 'identity 'byte-optimizer 'byte-optimize-identity) | |
| 863 | |
| 864 (put '+ 'byte-optimizer 'byte-optimize-plus) | |
| 865 (put '* 'byte-optimizer 'byte-optimize-multiply) | |
| 866 (put '- 'byte-optimizer 'byte-optimize-minus) | |
| 867 (put '/ 'byte-optimizer 'byte-optimize-divide) | |
| 868 (put 'max 'byte-optimizer 'byte-optimize-associative-math) | |
| 869 (put 'min 'byte-optimizer 'byte-optimize-associative-math) | |
| 870 | |
| 871 (put '= 'byte-optimizer 'byte-optimize-binary-predicate) | |
| 872 (put 'eq 'byte-optimizer 'byte-optimize-binary-predicate) | |
| 873 (put 'eql 'byte-optimizer 'byte-optimize-binary-predicate) | |
| 874 (put 'equal 'byte-optimizer 'byte-optimize-binary-predicate) | |
| 875 (put 'string= 'byte-optimizer 'byte-optimize-binary-predicate) | |
| 876 (put 'string-equal 'byte-optimizer 'byte-optimize-binary-predicate) | |
| 877 | |
| 878 (put '< 'byte-optimizer 'byte-optimize-predicate) | |
| 879 (put '> 'byte-optimizer 'byte-optimize-predicate) | |
| 880 (put '<= 'byte-optimizer 'byte-optimize-predicate) | |
| 881 (put '>= 'byte-optimizer 'byte-optimize-predicate) | |
| 882 (put '1+ 'byte-optimizer 'byte-optimize-predicate) | |
| 883 (put '1- 'byte-optimizer 'byte-optimize-predicate) | |
| 884 (put 'not 'byte-optimizer 'byte-optimize-predicate) | |
| 885 (put 'null 'byte-optimizer 'byte-optimize-predicate) | |
| 886 (put 'memq 'byte-optimizer 'byte-optimize-predicate) | |
| 887 (put 'consp 'byte-optimizer 'byte-optimize-predicate) | |
| 888 (put 'listp 'byte-optimizer 'byte-optimize-predicate) | |
| 889 (put 'symbolp 'byte-optimizer 'byte-optimize-predicate) | |
| 890 (put 'stringp 'byte-optimizer 'byte-optimize-predicate) | |
| 891 (put 'string< 'byte-optimizer 'byte-optimize-predicate) | |
| 892 (put 'string-lessp 'byte-optimizer 'byte-optimize-predicate) | |
| 893 | |
| 894 (put 'logand 'byte-optimizer 'byte-optimize-logmumble) | |
| 895 (put 'logior 'byte-optimizer 'byte-optimize-logmumble) | |
| 896 (put 'logxor 'byte-optimizer 'byte-optimize-logmumble) | |
| 897 (put 'lognot 'byte-optimizer 'byte-optimize-predicate) | |
| 898 | |
| 899 (put 'car 'byte-optimizer 'byte-optimize-predicate) | |
| 900 (put 'cdr 'byte-optimizer 'byte-optimize-predicate) | |
| 901 (put 'car-safe 'byte-optimizer 'byte-optimize-predicate) | |
| 902 (put 'cdr-safe 'byte-optimizer 'byte-optimize-predicate) | |
| 903 | |
| 904 | |
| 905 ;; I'm not convinced that this is necessary. Doesn't the optimizer loop | |
| 906 ;; take care of this? - Jamie | |
| 907 ;; I think this may some times be necessary to reduce eg. (quote 5) to 5, | |
| 908 ;; so arithmetic optimizers recognize the numeric constant. - Hallvard | |
| 909 (put 'quote 'byte-optimizer 'byte-optimize-quote) | |
| 910 (defun byte-optimize-quote (form) | |
| 911 (if (or (consp (nth 1 form)) | |
| 912 (and (symbolp (nth 1 form)) | |
| 913 ;; XEmacs addition: | |
| 914 (not (keywordp (nth 1 form))) | |
| 915 (not (memq (nth 1 form) '(nil t))))) | |
| 916 form | |
| 917 (nth 1 form))) | |
| 918 | |
| 919 (defun byte-optimize-zerop (form) | |
| 920 (cond ((numberp (nth 1 form)) | |
| 921 (eval form)) | |
| 922 (byte-compile-delete-errors | |
| 923 (list '= (nth 1 form) 0)) | |
| 924 (form))) | |
| 925 | |
| 926 (put 'zerop 'byte-optimizer 'byte-optimize-zerop) | |
| 927 | |
| 928 (defun byte-optimize-and (form) | |
| 929 ;; Simplify if less than 2 args. | |
| 930 ;; if there is a literal nil in the args to `and', throw it and following | |
| 931 ;; forms away, and surround the `and' with (progn ... nil). | |
| 932 (cond ((null (cdr form))) | |
| 933 ((memq nil form) | |
| 934 (list 'progn | |
| 935 (byte-optimize-and | |
| 936 (prog1 (setq form (copy-sequence form)) | |
| 937 (while (nth 1 form) | |
| 938 (setq form (cdr form))) | |
| 939 (setcdr form nil))) | |
| 940 nil)) | |
| 941 ((null (cdr (cdr form))) | |
| 942 (nth 1 form)) | |
| 943 ((byte-optimize-predicate form)))) | |
| 944 | |
| 945 (defun byte-optimize-or (form) | |
| 946 ;; Throw away nil's, and simplify if less than 2 args. | |
| 947 ;; If there is a literal non-nil constant in the args to `or', throw away all | |
| 948 ;; following forms. | |
| 949 (if (memq nil form) | |
| 950 (setq form (delq nil (copy-sequence form)))) | |
| 951 (let ((rest form)) | |
| 952 (while (cdr (setq rest (cdr rest))) | |
| 953 (if (byte-compile-trueconstp (car rest)) | |
| 954 (setq form (copy-sequence form) | |
| 955 rest (setcdr (memq (car rest) form) nil)))) | |
| 956 (if (cdr (cdr form)) | |
| 957 (byte-optimize-predicate form) | |
| 958 (nth 1 form)))) | |
| 959 | |
| 960 (defun byte-optimize-cond (form) | |
| 961 ;; if any clauses have a literal nil as their test, throw them away. | |
| 962 ;; if any clause has a literal non-nil constant as its test, throw | |
| 963 ;; away all following clauses. | |
| 964 (let (rest) | |
| 965 ;; This must be first, to reduce (cond (t ...) (nil)) to (progn t ...) | |
| 966 (while (setq rest (assq nil (cdr form))) | |
| 967 (setq form (delq rest (copy-sequence form)))) | |
| 968 (if (memq nil (cdr form)) | |
| 969 (setq form (delq nil (copy-sequence form)))) | |
| 970 (setq rest form) | |
| 971 (while (setq rest (cdr rest)) | |
| 972 (cond ((byte-compile-trueconstp (car-safe (car rest))) | |
| 973 (cond ((eq rest (cdr form)) | |
| 974 (setq form | |
| 975 (if (cdr (car rest)) | |
| 976 (if (cdr (cdr (car rest))) | |
| 977 (cons 'progn (cdr (car rest))) | |
| 978 (nth 1 (car rest))) | |
| 979 (car (car rest))))) | |
| 980 ((cdr rest) | |
| 981 (setq form (copy-sequence form)) | |
| 982 (setcdr (memq (car rest) form) nil))) | |
| 983 (setq rest nil))))) | |
| 984 ;; | |
| 985 ;; Turn (cond (( <x> )) ... ) into (or <x> (cond ... )) | |
| 986 (if (eq 'cond (car-safe form)) | |
| 987 (let ((clauses (cdr form))) | |
| 988 (if (and (consp (car clauses)) | |
| 989 (null (cdr (car clauses)))) | |
| 990 (list 'or (car (car clauses)) | |
| 991 (byte-optimize-cond | |
| 992 (cons (car form) (cdr (cdr form))))) | |
| 993 form)) | |
| 994 form)) | |
| 995 | |
| 996 (defun byte-optimize-if (form) | |
| 997 ;; (if <true-constant> <then> <else...>) ==> <then> | |
| 998 ;; (if <false-constant> <then> <else...>) ==> (progn <else...>) | |
| 999 ;; (if <test> nil <else...>) ==> (if (not <test>) (progn <else...>)) | |
| 1000 ;; (if <test> <then> nil) ==> (if <test> <then>) | |
| 1001 (let ((clause (nth 1 form))) | |
| 1002 (cond ((byte-compile-trueconstp clause) | |
| 1003 (nth 2 form)) | |
| 1004 ((null clause) | |
| 1005 (if (nthcdr 4 form) | |
| 1006 (cons 'progn (nthcdr 3 form)) | |
| 1007 (nth 3 form))) | |
| 1008 ((nth 2 form) | |
| 1009 (if (equal '(nil) (nthcdr 3 form)) | |
| 1010 (list 'if clause (nth 2 form)) | |
| 1011 form)) | |
| 1012 ((or (nth 3 form) (nthcdr 4 form)) | |
| 1013 (list 'if | |
| 1014 ;; Don't make a double negative; | |
| 1015 ;; instead, take away the one that is there. | |
| 1016 (if (and (consp clause) (memq (car clause) '(not null)) | |
| 1017 (= (length clause) 2)) ; (not xxxx) or (not (xxxx)) | |
| 1018 (nth 1 clause) | |
| 1019 (list 'not clause)) | |
| 1020 (if (nthcdr 4 form) | |
| 1021 (cons 'progn (nthcdr 3 form)) | |
| 1022 (nth 3 form)))) | |
| 1023 (t | |
| 1024 (list 'progn clause nil))))) | |
| 1025 | |
| 1026 (defun byte-optimize-while (form) | |
| 1027 (if (nth 1 form) | |
| 1028 form)) | |
| 1029 | |
| 1030 (put 'and 'byte-optimizer 'byte-optimize-and) | |
| 1031 (put 'or 'byte-optimizer 'byte-optimize-or) | |
| 1032 (put 'cond 'byte-optimizer 'byte-optimize-cond) | |
| 1033 (put 'if 'byte-optimizer 'byte-optimize-if) | |
| 1034 (put 'while 'byte-optimizer 'byte-optimize-while) | |
| 1035 | |
| 1036 ;; byte-compile-negation-optimizer lives in bytecomp.el | |
| 1037 ;(put '/= 'byte-optimizer 'byte-compile-negation-optimizer) | |
| 1038 (put 'atom 'byte-optimizer 'byte-compile-negation-optimizer) | |
| 1039 (put 'nlistp 'byte-optimizer 'byte-compile-negation-optimizer) | |
| 1040 | |
| 1041 | |
| 1042 (defun byte-optimize-funcall (form) | |
| 1043 ;; (funcall '(lambda ...) ...) ==> ((lambda ...) ...) | |
| 1044 ;; (funcall 'foo ...) ==> (foo ...) | |
| 1045 (let ((fn (nth 1 form))) | |
| 1046 (if (memq (car-safe fn) '(quote function)) | |
| 1047 (cons (nth 1 fn) (cdr (cdr form))) | |
| 1048 form))) | |
| 1049 | |
| 1050 (defun byte-optimize-apply (form) | |
| 1051 ;; If the last arg is a literal constant, turn this into a funcall. | |
| 1052 ;; The funcall optimizer can then transform (funcall 'foo ...) -> (foo ...). | |
| 1053 (let ((fn (nth 1 form)) | |
| 1054 (last (nth (1- (length form)) form))) ; I think this really is fastest | |
| 1055 (or (if (or (null last) | |
| 1056 (eq (car-safe last) 'quote)) | |
| 1057 (if (listp (nth 1 last)) | |
| 1058 (let ((butlast (nreverse (cdr (reverse (cdr (cdr form))))))) | |
| 1059 (nconc (list 'funcall fn) butlast | |
| 1060 (mapcar #'(lambda (x) (list 'quote x)) (nth 1 last)))) | |
| 1061 (byte-compile-warn | |
| 1062 "last arg to apply can't be a literal atom: %s" | |
| 1063 (prin1-to-string last)) | |
| 1064 nil)) | |
| 1065 form))) | |
| 1066 | |
| 1067 (put 'funcall 'byte-optimizer 'byte-optimize-funcall) | |
| 1068 (put 'apply 'byte-optimizer 'byte-optimize-apply) | |
| 1069 | |
| 1070 | |
| 1071 (put 'let 'byte-optimizer 'byte-optimize-letX) | |
| 1072 (put 'let* 'byte-optimizer 'byte-optimize-letX) | |
| 1073 (defun byte-optimize-letX (form) | |
| 1074 (cond ((null (nth 1 form)) | |
| 1075 ;; No bindings | |
| 1076 (cons 'progn (cdr (cdr form)))) | |
| 1077 ((or (nth 2 form) (nthcdr 3 form)) | |
| 1078 form) | |
| 1079 ;; The body is nil | |
| 1080 ((eq (car form) 'let) | |
| 1081 (append '(progn) (mapcar 'car-safe (mapcar 'cdr-safe (nth 1 form))) | |
| 1082 '(nil))) | |
| 1083 (t | |
| 1084 (let ((binds (reverse (nth 1 form)))) | |
| 1085 (list 'let* (reverse (cdr binds)) (nth 1 (car binds)) nil))))) | |
| 1086 | |
| 1087 | |
| 1088 (put 'nth 'byte-optimizer 'byte-optimize-nth) | |
| 1089 (defun byte-optimize-nth (form) | |
| 1090 (if (and (= (safe-length form) 3) (memq (nth 1 form) '(0 1))) | |
| 1091 (list 'car (if (zerop (nth 1 form)) | |
| 1092 (nth 2 form) | |
| 1093 (list 'cdr (nth 2 form)))) | |
| 1094 (byte-optimize-predicate form))) | |
| 1095 | |
| 1096 (put 'nthcdr 'byte-optimizer 'byte-optimize-nthcdr) | |
| 1097 (defun byte-optimize-nthcdr (form) | |
| 1098 (if (and (= (safe-length form) 3) (not (memq (nth 1 form) '(0 1 2)))) | |
| 1099 (byte-optimize-predicate form) | |
| 1100 (let ((count (nth 1 form))) | |
| 1101 (setq form (nth 2 form)) | |
| 1102 (while (>= (setq count (1- count)) 0) | |
| 1103 (setq form (list 'cdr form))) | |
| 1104 form))) | |
| 1105 | |
| 1106 ;;; enumerating those functions which need not be called if the returned | |
| 1107 ;;; value is not used. That is, something like | |
| 1108 ;;; (progn (list (something-with-side-effects) (yow)) | |
| 1109 ;;; (foo)) | |
| 1110 ;;; may safely be turned into | |
| 1111 ;;; (progn (progn (something-with-side-effects) (yow)) | |
| 1112 ;;; (foo)) | |
| 1113 ;;; Further optimizations will turn (progn (list 1 2 3) 'foo) into 'foo. | |
| 1114 | |
| 1115 ;;; I wonder if I missed any :-\) | |
| 1116 (let ((side-effect-free-fns | |
| 1117 '(% * + - / /= 1+ 1- < <= = > >= abs acos append aref ash asin atan | |
| 1118 assoc assq | |
| 1119 boundp buffer-file-name buffer-local-variables buffer-modified-p | |
| 1120 buffer-substring | |
| 1121 capitalize car-less-than-car car cdr ceiling concat | |
| 1122 ;; coordinates-in-window-p not in XEmacs | |
| 1123 copy-marker cos count-lines | |
| 1124 default-boundp default-value documentation downcase | |
| 1125 elt exp expt fboundp featurep | |
| 1126 file-directory-p file-exists-p file-locked-p file-name-absolute-p | |
| 1127 file-newer-than-file-p file-readable-p file-symlink-p file-writable-p | |
| 1128 float floor format | |
| 1129 get get-buffer get-buffer-window getenv get-file-buffer | |
| 1130 ;; hash-table functions | |
| 1131 make-hash-table copy-hash-table | |
| 1132 gethash | |
| 1133 hash-table-count | |
| 1134 hash-table-rehash-size | |
| 1135 hash-table-rehash-threshold | |
| 1136 hash-table-size | |
| 1137 hash-table-test | |
| 1138 hash-table-type | |
| 1139 ;; | |
| 1140 int-to-string | |
| 1141 length log log10 logand logb logior lognot logxor lsh | |
| 1142 marker-buffer max member memq min mod | |
| 1143 next-window nth nthcdr number-to-string | |
| 1144 parse-colon-path previous-window | |
| 1145 radians-to-degrees rassq regexp-quote reverse round | |
| 1146 sin sqrt string< string= string-equal string-lessp string-to-char | |
| 1147 string-to-int string-to-number substring symbol-plist | |
| 1148 tan upcase user-variable-p vconcat | |
| 1149 ;; XEmacs change: window-edges -> window-pixel-edges | |
| 1150 window-buffer window-dedicated-p window-pixel-edges window-height | |
| 1151 window-hscroll window-minibuffer-p window-width | |
| 1152 zerop | |
| 1153 ;; functions defined by cl | |
| 1154 oddp evenp plusp minusp | |
| 1155 abs expt signum last butlast ldiff | |
| 1156 pairlis gcd lcm | |
| 1157 isqrt floor* ceiling* truncate* round* mod* rem* subseq | |
| 1158 list-length get* getf | |
| 1159 )) | |
| 1160 (side-effect-and-error-free-fns | |
| 1161 '(arrayp atom | |
| 1162 bobp bolp buffer-end buffer-list buffer-size buffer-string bufferp | |
| 1163 car-safe case-table-p cdr-safe char-or-string-p char-table-p | |
| 1164 characterp commandp cons | |
| 1165 consolep console-live-p consp | |
| 1166 current-buffer | |
| 1167 ;; XEmacs: extent functions, frame-live-p, various other stuff | |
| 1168 devicep device-live-p | |
| 1169 dot dot-marker eobp eolp eq eql equal eventp extentp | |
| 1170 extent-live-p floatp framep frame-live-p | |
| 1171 get-largest-window get-lru-window | |
| 1172 hash-table-p | |
| 1173 identity ignore integerp integer-or-marker-p interactive-p | |
| 1174 invocation-directory invocation-name | |
| 1175 ;; keymapp may autoload in XEmacs, so not on this list! | |
| 1176 list listp | |
| 1177 make-marker mark mark-marker markerp memory-limit minibuffer-window | |
| 1178 ;; mouse-movement-p not in XEmacs | |
| 1179 natnump nlistp not null number-or-marker-p numberp | |
| 1180 one-window-p ;; overlayp not in XEmacs | |
| 1181 point point-marker point-min point-max processp | |
| 1182 range-table-p | |
| 1183 selected-window sequencep stringp subrp symbolp syntax-table-p | |
| 1184 user-full-name user-login-name user-original-login-name | |
| 1185 user-real-login-name user-real-uid user-uid | |
| 1186 vector vectorp | |
| 1187 window-configuration-p window-live-p windowp | |
| 1188 ;; Functions defined by cl | |
| 1189 eql floatp-safe list* subst acons equalp random-state-p | |
| 1190 copy-tree sublis | |
| 1191 ))) | |
| 1192 (dolist (fn side-effect-free-fns) | |
| 1193 (put fn 'side-effect-free t)) | |
| 1194 (dolist (fn side-effect-and-error-free-fns) | |
| 1195 (put fn 'side-effect-free 'error-free))) | |
| 1196 | |
| 1197 | |
| 1198 (defun byte-compile-splice-in-already-compiled-code (form) | |
| 1199 ;; form is (byte-code "..." [...] n) | |
| 1200 (if (not (memq byte-optimize '(t lap))) | |
| 1201 (byte-compile-normal-call form) | |
| 1202 (byte-inline-lapcode | |
| 1203 (byte-decompile-bytecode-1 (nth 1 form) (nth 2 form) t)) | |
| 1204 (setq byte-compile-maxdepth (max (+ byte-compile-depth (nth 3 form)) | |
| 1205 byte-compile-maxdepth)) | |
| 1206 (setq byte-compile-depth (1+ byte-compile-depth)))) | |
| 1207 | |
| 1208 (put 'byte-code 'byte-compile 'byte-compile-splice-in-already-compiled-code) | |
| 1209 | |
| 1210 | |
| 1211 (defconst byte-constref-ops | |
| 1212 '(byte-constant byte-constant2 byte-varref byte-varset byte-varbind)) | |
| 1213 | |
| 1214 ;;; This function extracts the bitfields from variable-length opcodes. | |
| 1215 ;;; Originally defined in disass.el (which no longer uses it.) | |
| 1216 | |
| 1217 (defun disassemble-offset () | |
| 1218 "Don't call this!" | |
| 1219 ;; fetch and return the offset for the current opcode. | |
| 1220 ;; return NIL if this opcode has no offset | |
| 1221 ;; OP, PTR and BYTES are used and set dynamically | |
| 1222 (defvar op) | |
| 1223 (defvar ptr) | |
| 1224 (defvar bytes) | |
| 1225 (cond ((< op byte-nth) | |
| 1226 (let ((tem (logand op 7))) | |
| 1227 (setq op (logand op 248)) | |
| 1228 (cond ((eq tem 6) | |
| 1229 (setq ptr (1+ ptr)) ;offset in next byte | |
| 1230 ;; char-to-int to avoid downstream problems | |
| 1231 ;; caused by chars appearing where ints are | |
| 1232 ;; expected. In bytecode the bytes in the | |
| 1233 ;; opcode string are always interpreted as ints. | |
| 1234 (char-to-int (aref bytes ptr))) | |
| 1235 ((eq tem 7) | |
| 1236 (setq ptr (1+ ptr)) ;offset in next 2 bytes | |
| 1237 (+ (aref bytes ptr) | |
| 1238 (progn (setq ptr (1+ ptr)) | |
| 1239 (lsh (aref bytes ptr) 8)))) | |
| 1240 (t tem)))) ;offset was in opcode | |
| 1241 ((>= op byte-constant) | |
| 1242 (prog1 (- op byte-constant) ;offset in opcode | |
| 1243 (setq op byte-constant))) | |
| 1244 ((and (>= op byte-constant2) | |
| 1245 (<= op byte-goto-if-not-nil-else-pop)) | |
| 1246 (setq ptr (1+ ptr)) ;offset in next 2 bytes | |
| 1247 (+ (aref bytes ptr) | |
| 1248 (progn (setq ptr (1+ ptr)) | |
| 1249 (lsh (aref bytes ptr) 8)))) | |
| 1250 ;; XEmacs: this code was here before. FSF's first comparison | |
| 1251 ;; is (>= op byte-listN). It appears that the rel-goto stuff | |
| 1252 ;; does not exist in FSF 19.30. It doesn't exist in 19.28 | |
| 1253 ;; either, so I'm going to assume that this is an improvement | |
| 1254 ;; on our part and leave it in. --ben | |
| 1255 ((and (>= op byte-rel-goto) | |
| 1256 (<= op byte-insertN)) | |
| 1257 (setq ptr (1+ ptr)) ;offset in next byte | |
| 1258 ;; Use char-to-int to avoid downstream problems caused by | |
| 1259 ;; chars appearing where ints are expected. In bytecode | |
| 1260 ;; the bytes in the opcode string are always interpreted as | |
| 1261 ;; ints. | |
| 1262 (char-to-int (aref bytes ptr))))) | |
| 1263 | |
| 1264 | |
| 1265 ;;; This de-compiler is used for inline expansion of compiled functions, | |
| 1266 ;;; and by the disassembler. | |
| 1267 ;;; | |
| 1268 ;;; This list contains numbers, which are pc values, | |
| 1269 ;;; before each instruction. | |
| 1270 (defun byte-decompile-bytecode (bytes constvec) | |
| 1271 "Turns BYTECODE into lapcode, referring to CONSTVEC." | |
| 1272 (let ((byte-compile-constants nil) | |
| 1273 (byte-compile-variables nil) | |
| 1274 (byte-compile-tag-number 0)) | |
| 1275 (byte-decompile-bytecode-1 bytes constvec))) | |
| 1276 | |
| 1277 ;; As byte-decompile-bytecode, but updates | |
| 1278 ;; byte-compile-{constants, variables, tag-number}. | |
| 1279 ;; If MAKE-SPLICEABLE is true, then `return' opcodes are replaced | |
| 1280 ;; with `goto's destined for the end of the code. | |
| 1281 ;; That is for use by the compiler. | |
| 1282 ;; If MAKE-SPLICEABLE is nil, we are being called for the disassembler. | |
| 1283 ;; In that case, we put a pc value into the list | |
| 1284 ;; before each insn (or its label). | |
| 1285 (defun byte-decompile-bytecode-1 (bytes constvec &optional make-spliceable) | |
| 1286 (let ((length (length bytes)) | |
| 1287 (ptr 0) optr tags op offset | |
| 1288 ;; tag unused | |
| 1289 lap tmp | |
| 1290 endtag | |
| 1291 ;; (retcount 0) unused | |
| 1292 ) | |
| 1293 (while (not (= ptr length)) | |
| 1294 (or make-spliceable | |
| 1295 (setq lap (cons ptr lap))) | |
| 1296 (setq op (aref bytes ptr) | |
| 1297 optr ptr | |
| 1298 offset (disassemble-offset)) ; this does dynamic-scope magic | |
| 1299 (setq op (aref byte-code-vector op)) | |
| 1300 ;; XEmacs: the next line in FSF 19.30 reads | |
| 1301 ;; (cond ((memq op byte-goto-ops) | |
| 1302 ;; see the comment above about byte-rel-goto in XEmacs. | |
| 1303 (cond ((or (memq op byte-goto-ops) | |
| 1304 (cond ((memq op byte-rel-goto-ops) | |
| 1305 (setq op (aref byte-code-vector | |
| 1306 (- (symbol-value op) | |
| 1307 (- byte-rel-goto byte-goto)))) | |
| 1308 (setq offset (+ ptr (- offset 127))) | |
| 1309 t))) | |
| 1310 ;; it's a pc | |
| 1311 (setq offset | |
| 1312 (cdr (or (assq offset tags) | |
| 1313 (car (setq tags | |
| 1314 (cons (cons offset | |
| 1315 (byte-compile-make-tag)) | |
| 1316 tags))))))) | |
| 1317 ((cond ((eq op 'byte-constant2) (setq op 'byte-constant) t) | |
| 1318 ((memq op byte-constref-ops))) | |
| 1319 (setq tmp (aref constvec offset) | |
| 1320 offset (if (eq op 'byte-constant) | |
| 1321 (byte-compile-get-constant tmp) | |
| 1322 (or (assq tmp byte-compile-variables) | |
| 1323 (car (setq byte-compile-variables | |
| 1324 (cons (list tmp) | |
| 1325 byte-compile-variables))))))) | |
| 1326 ((and make-spliceable | |
| 1327 (eq op 'byte-return)) | |
| 1328 (if (= ptr (1- length)) | |
| 1329 (setq op nil) | |
| 1330 (setq offset (or endtag (setq endtag (byte-compile-make-tag))) | |
| 1331 op 'byte-goto)))) | |
| 1332 ;; lap = ( [ (pc . (op . arg)) ]* ) | |
| 1333 (setq lap (cons (cons optr (cons op (or offset 0))) | |
| 1334 lap)) | |
| 1335 (setq ptr (1+ ptr))) | |
| 1336 ;; take off the dummy nil op that we replaced a trailing "return" with. | |
| 1337 (let ((rest lap)) | |
| 1338 (while rest | |
| 1339 (cond ((numberp (car rest))) | |
| 1340 ((setq tmp (assq (car (car rest)) tags)) | |
| 1341 ;; this addr is jumped to | |
| 1342 (setcdr rest (cons (cons nil (cdr tmp)) | |
| 1343 (cdr rest))) | |
| 1344 (setq tags (delq tmp tags)) | |
| 1345 (setq rest (cdr rest)))) | |
| 1346 (setq rest (cdr rest)))) | |
| 1347 (if tags (error "optimizer error: missed tags %s" tags)) | |
| 1348 (if (null (car (cdr (car lap)))) | |
| 1349 (setq lap (cdr lap))) | |
| 1350 (if endtag | |
| 1351 (setq lap (cons (cons nil endtag) lap))) | |
| 1352 ;; remove addrs, lap = ( [ (op . arg) | (TAG tagno) ]* ) | |
| 1353 (mapcar #'(lambda (elt) (if (numberp elt) elt (cdr elt))) | |
| 1354 (nreverse lap)))) | |
| 1355 | |
| 1356 | |
| 1357 ;;; peephole optimizer | |
| 1358 | |
| 1359 (defconst byte-tagref-ops (cons 'TAG byte-goto-ops)) | |
| 1360 | |
| 1361 (defconst byte-conditional-ops | |
| 1362 '(byte-goto-if-nil byte-goto-if-not-nil byte-goto-if-nil-else-pop | |
| 1363 byte-goto-if-not-nil-else-pop)) | |
| 1364 | |
| 1365 (defconst byte-after-unbind-ops | |
| 1366 '(byte-constant byte-dup | |
| 1367 byte-symbolp byte-consp byte-stringp byte-listp byte-numberp byte-integerp | |
| 1368 byte-eq byte-equal byte-not | |
| 1369 byte-cons byte-list1 byte-list2 ; byte-list3 byte-list4 | |
| 1370 byte-interactive-p) | |
| 1371 ;; How about other side-effect-free-ops? Is it safe to move an | |
| 1372 ;; error invocation (such as from nth) out of an unwind-protect? | |
| 1373 "Byte-codes that can be moved past an unbind.") | |
| 1374 | |
| 1375 (defconst byte-compile-side-effect-and-error-free-ops | |
| 1376 '(byte-constant byte-dup byte-symbolp byte-consp byte-stringp byte-listp | |
| 1377 byte-integerp byte-numberp byte-eq byte-equal byte-not byte-car-safe | |
| 1378 byte-cdr-safe byte-cons byte-list1 byte-list2 byte-point byte-point-max | |
| 1379 byte-point-min byte-following-char byte-preceding-char | |
| 1380 byte-current-column byte-eolp byte-eobp byte-bolp byte-bobp | |
| 1381 byte-current-buffer byte-interactive-p)) | |
| 1382 | |
| 1383 (defconst byte-compile-side-effect-free-ops | |
| 1384 (nconc | |
| 1385 '(byte-varref byte-nth byte-memq byte-car byte-cdr byte-length byte-aref | |
| 1386 byte-symbol-value byte-get byte-concat2 byte-concat3 byte-sub1 byte-add1 | |
| 1387 byte-eqlsign byte-gtr byte-lss byte-leq byte-geq byte-diff byte-negate | |
| 1388 byte-plus byte-max byte-min byte-mult byte-char-after byte-char-syntax | |
| 1389 byte-buffer-substring byte-string= byte-string< byte-nthcdr byte-elt | |
| 1390 byte-member byte-assq byte-quo byte-rem) | |
| 1391 byte-compile-side-effect-and-error-free-ops)) | |
| 1392 | |
| 1393 ;;; This piece of shit is because of the way DEFVAR_BOOL() variables work. | |
| 1394 ;;; Consider the code | |
| 1395 ;;; | |
| 1396 ;;; (defun foo (flag) | |
| 1397 ;;; (let ((old-pop-ups pop-up-windows) | |
| 1398 ;;; (pop-up-windows flag)) | |
| 1399 ;;; (cond ((not (eq pop-up-windows old-pop-ups)) | |
| 1400 ;;; (setq old-pop-ups pop-up-windows) | |
| 1401 ;;; ...)))) | |
| 1402 ;;; | |
| 1403 ;;; Uncompiled, old-pop-ups will always be set to nil or t, even if FLAG is | |
| 1404 ;;; something else. But if we optimize | |
| 1405 ;;; | |
| 1406 ;;; varref flag | |
| 1407 ;;; varbind pop-up-windows | |
| 1408 ;;; varref pop-up-windows | |
| 1409 ;;; not | |
| 1410 ;;; to | |
| 1411 ;;; varref flag | |
| 1412 ;;; dup | |
| 1413 ;;; varbind pop-up-windows | |
| 1414 ;;; not | |
| 1415 ;;; | |
| 1416 ;;; we break the program, because it will appear that pop-up-windows and | |
| 1417 ;;; old-pop-ups are not EQ when really they are. So we have to know what | |
| 1418 ;;; the BOOL variables are, and not perform this optimization on them. | |
| 1419 ;;; | |
| 1420 | |
| 1421 ;;; This used to hold a large list of boolean variables, which had to | |
| 1422 ;;; be updated every time a new DEFVAR_BOOL is added, making it very | |
| 1423 ;;; hard to maintain. Such a list is not necessary under XEmacs, | |
| 1424 ;;; where we can use `built-in-variable-type' to query for boolean | |
| 1425 ;;; variables. | |
| 1426 | |
| 1427 ;(defconst byte-boolean-vars | |
| 1428 ; '(abbrev-all-caps purify-flag find-file-compare-truenames | |
| 1429 ; find-file-use-truenames delete-auto-save-files byte-metering-on | |
| 1430 ; x-seppuku-on-epipe zmacs-regions zmacs-region-active-p | |
| 1431 ; zmacs-region-stays atomic-extent-goto-char-p | |
| 1432 ; suppress-early-error-handler-backtrace noninteractive | |
| 1433 ; inhibit-early-packages inhibit-autoloads debug-paths | |
| 1434 ; inhibit-site-lisp debug-on-quit debug-on-next-call | |
| 1435 ; modifier-keys-are-sticky x-allow-sendevents | |
| 1436 ; mswindows-dynamic-frame-resize focus-follows-mouse | |
| 1437 ; inhibit-input-event-recording enable-multibyte-characters | |
| 1438 ; disable-auto-save-when-buffer-shrinks | |
| 1439 ; allow-deletion-of-last-visible-frame indent-tabs-mode | |
| 1440 ; load-in-progress load-warn-when-source-newer | |
| 1441 ; load-warn-when-source-only load-ignore-elc-files | |
| 1442 ; load-force-doc-strings fail-on-bucky-bit-character-escapes | |
| 1443 ; popup-menu-titles menubar-show-keybindings completion-ignore-case | |
| 1444 ; canna-empty-info canna-through-info canna-underline | |
| 1445 ; canna-inhibit-hankakukana enable-multibyte-characters | |
| 1446 ; re-short-flag x-handle-non-fully-specified-fonts | |
| 1447 ; print-escape-newlines print-readably delete-exited-processes | |
| 1448 ; windowed-process-io visible-bell no-redraw-on-reenter | |
| 1449 ; cursor-in-echo-area inhibit-warning-display | |
| 1450 ; column-number-start-at-one parse-sexp-ignore-comments | |
| 1451 ; words-include-escapes scroll-on-clipped-lines) | |
| 1452 ; "DEFVAR_BOOL variables. Giving these any non-nil value sets them to t. | |
| 1453 ;If this does not enumerate all DEFVAR_BOOL variables, the byte-optimizer | |
| 1454 ;may generate incorrect code.") | |
| 1455 | |
| 1456 (defun byte-optimize-lapcode (lap &optional for-effect) | |
| 1457 "Simple peephole optimizer. LAP is both modified and returned." | |
| 1458 (let (lap0 ;; off0 unused | |
| 1459 lap1 ;; off1 | |
| 1460 lap2 ;; off2 | |
| 1461 (keep-going 'first-time) | |
| 1462 (add-depth 0) | |
| 1463 rest tmp tmp2 tmp3 | |
| 1464 (side-effect-free (if byte-compile-delete-errors | |
| 1465 byte-compile-side-effect-free-ops | |
| 1466 byte-compile-side-effect-and-error-free-ops))) | |
| 1467 (while keep-going | |
| 1468 (or (eq keep-going 'first-time) | |
| 1469 (byte-compile-log-lap " ---- next pass")) | |
| 1470 (setq rest lap | |
| 1471 keep-going nil) | |
| 1472 (while rest | |
| 1473 (setq lap0 (car rest) | |
| 1474 lap1 (nth 1 rest) | |
| 1475 lap2 (nth 2 rest)) | |
| 1476 | |
| 1477 ;; You may notice that sequences like "dup varset discard" are | |
| 1478 ;; optimized but sequences like "dup varset TAG1: discard" are not. | |
| 1479 ;; You may be tempted to change this; resist that temptation. | |
| 1480 (cond ;; | |
| 1481 ;; <side-effect-free> pop --> <deleted> | |
| 1482 ;; ...including: | |
| 1483 ;; const-X pop --> <deleted> | |
| 1484 ;; varref-X pop --> <deleted> | |
| 1485 ;; dup pop --> <deleted> | |
| 1486 ;; | |
| 1487 ((and (eq 'byte-discard (car lap1)) | |
| 1488 (memq (car lap0) side-effect-free)) | |
| 1489 (setq keep-going t) | |
| 1490 (setq tmp (aref byte-stack+-info (symbol-value (car lap0)))) | |
| 1491 (setq rest (cdr rest)) | |
| 1492 (cond ((= tmp 1) | |
| 1493 (byte-compile-log-lap | |
| 1494 " %s discard\t-->\t<deleted>" lap0) | |
| 1495 (setq lap (delq lap0 (delq lap1 lap)))) | |
| 1496 ((= tmp 0) | |
| 1497 (byte-compile-log-lap | |
| 1498 " %s discard\t-->\t<deleted> discard" lap0) | |
| 1499 (setq lap (delq lap0 lap))) | |
| 1500 ((= tmp -1) | |
| 1501 (byte-compile-log-lap | |
| 1502 " %s discard\t-->\tdiscard discard" lap0) | |
| 1503 (setcar lap0 'byte-discard) | |
| 1504 (setcdr lap0 0)) | |
| 1505 ((error "Optimizer error: too much on the stack")))) | |
| 1506 ;; | |
| 1507 ;; goto*-X X: --> X: | |
| 1508 ;; | |
| 1509 ((and (memq (car lap0) byte-goto-ops) | |
| 1510 (eq (cdr lap0) lap1)) | |
| 1511 (cond ((eq (car lap0) 'byte-goto) | |
| 1512 (setq lap (delq lap0 lap)) | |
| 1513 (setq tmp "<deleted>")) | |
| 1514 ((memq (car lap0) byte-goto-always-pop-ops) | |
| 1515 (setcar lap0 (setq tmp 'byte-discard)) | |
| 1516 (setcdr lap0 0)) | |
| 1517 ((error "Depth conflict at tag %d" (nth 2 lap0)))) | |
| 1518 (and (memq byte-optimize-log '(t byte)) | |
| 1519 (byte-compile-log " (goto %s) %s:\t-->\t%s %s:" | |
| 1520 (nth 1 lap1) (nth 1 lap1) | |
| 1521 tmp (nth 1 lap1))) | |
| 1522 (setq keep-going t)) | |
| 1523 ;; | |
| 1524 ;; varset-X varref-X --> dup varset-X | |
| 1525 ;; varbind-X varref-X --> dup varbind-X | |
| 1526 ;; const/dup varset-X varref-X --> const/dup varset-X const/dup | |
| 1527 ;; const/dup varbind-X varref-X --> const/dup varbind-X const/dup | |
| 1528 ;; The latter two can enable other optimizations. | |
| 1529 ;; | |
| 1530 ((and (eq 'byte-varref (car lap2)) | |
| 1531 (eq (cdr lap1) (cdr lap2)) | |
| 1532 (memq (car lap1) '(byte-varset byte-varbind))) | |
| 1533 (if (and (setq tmp (eq (built-in-variable-type (car (cdr lap2))) | |
| 1534 'boolean)) | |
| 1535 (not (eq (car lap0) 'byte-constant))) | |
| 1536 nil | |
| 1537 (setq keep-going t) | |
| 1538 (if (memq (car lap0) '(byte-constant byte-dup)) | |
| 1539 (progn | |
| 1540 (setq tmp (if (or (not tmp) | |
| 1541 (memq (car (cdr lap0)) '(nil t))) | |
| 1542 (cdr lap0) | |
| 1543 (byte-compile-get-constant t))) | |
| 1544 (byte-compile-log-lap " %s %s %s\t-->\t%s %s %s" | |
| 1545 lap0 lap1 lap2 lap0 lap1 | |
| 1546 (cons (car lap0) tmp)) | |
| 1547 (setcar lap2 (car lap0)) | |
| 1548 (setcdr lap2 tmp)) | |
| 1549 (byte-compile-log-lap " %s %s\t-->\tdup %s" lap1 lap2 lap1) | |
| 1550 (setcar lap2 (car lap1)) | |
| 1551 (setcar lap1 'byte-dup) | |
| 1552 (setcdr lap1 0) | |
| 1553 ;; The stack depth gets locally increased, so we will | |
| 1554 ;; increase maxdepth in case depth = maxdepth here. | |
| 1555 ;; This can cause the third argument to byte-code to | |
| 1556 ;; be larger than necessary. | |
| 1557 (setq add-depth 1)))) | |
| 1558 ;; | |
| 1559 ;; dup varset-X discard --> varset-X | |
| 1560 ;; dup varbind-X discard --> varbind-X | |
| 1561 ;; (the varbind variant can emerge from other optimizations) | |
| 1562 ;; | |
| 1563 ((and (eq 'byte-dup (car lap0)) | |
| 1564 (eq 'byte-discard (car lap2)) | |
| 1565 (memq (car lap1) '(byte-varset byte-varbind))) | |
| 1566 (byte-compile-log-lap " dup %s discard\t-->\t%s" lap1 lap1) | |
| 1567 (setq keep-going t | |
| 1568 rest (cdr rest)) | |
| 1569 (setq lap (delq lap0 (delq lap2 lap)))) | |
| 1570 ;; | |
| 1571 ;; not goto-X-if-nil --> goto-X-if-non-nil | |
| 1572 ;; not goto-X-if-non-nil --> goto-X-if-nil | |
| 1573 ;; | |
| 1574 ;; it is wrong to do the same thing for the -else-pop variants. | |
| 1575 ;; | |
| 1576 ((and (eq 'byte-not (car lap0)) | |
| 1577 (or (eq 'byte-goto-if-nil (car lap1)) | |
| 1578 (eq 'byte-goto-if-not-nil (car lap1)))) | |
| 1579 (byte-compile-log-lap " not %s\t-->\t%s" | |
| 1580 lap1 | |
| 1581 (cons | |
| 1582 (if (eq (car lap1) 'byte-goto-if-nil) | |
| 1583 'byte-goto-if-not-nil | |
| 1584 'byte-goto-if-nil) | |
| 1585 (cdr lap1))) | |
| 1586 (setcar lap1 (if (eq (car lap1) 'byte-goto-if-nil) | |
| 1587 'byte-goto-if-not-nil | |
| 1588 'byte-goto-if-nil)) | |
| 1589 (setq lap (delq lap0 lap)) | |
| 1590 (setq keep-going t)) | |
| 1591 ;; | |
| 1592 ;; goto-X-if-nil goto-Y X: --> goto-Y-if-non-nil X: | |
| 1593 ;; goto-X-if-non-nil goto-Y X: --> goto-Y-if-nil X: | |
| 1594 ;; | |
| 1595 ;; it is wrong to do the same thing for the -else-pop variants. | |
| 1596 ;; | |
| 1597 ((and (or (eq 'byte-goto-if-nil (car lap0)) | |
| 1598 (eq 'byte-goto-if-not-nil (car lap0))) ; gotoX | |
| 1599 (eq 'byte-goto (car lap1)) ; gotoY | |
| 1600 (eq (cdr lap0) lap2)) ; TAG X | |
| 1601 (let ((inverse (if (eq 'byte-goto-if-nil (car lap0)) | |
| 1602 'byte-goto-if-not-nil 'byte-goto-if-nil))) | |
| 1603 (byte-compile-log-lap " %s %s %s:\t-->\t%s %s:" | |
| 1604 lap0 lap1 lap2 | |
| 1605 (cons inverse (cdr lap1)) lap2) | |
| 1606 (setq lap (delq lap0 lap)) | |
| 1607 (setcar lap1 inverse) | |
| 1608 (setq keep-going t))) | |
| 1609 ;; | |
| 1610 ;; const goto-if-* --> whatever | |
| 1611 ;; | |
| 1612 ((and (eq 'byte-constant (car lap0)) | |
| 1613 (memq (car lap1) byte-conditional-ops)) | |
| 1614 (cond ((if (or (eq (car lap1) 'byte-goto-if-nil) | |
| 1615 (eq (car lap1) 'byte-goto-if-nil-else-pop)) | |
| 1616 (car (cdr lap0)) | |
| 1617 (not (car (cdr lap0)))) | |
| 1618 (byte-compile-log-lap " %s %s\t-->\t<deleted>" | |
| 1619 lap0 lap1) | |
| 1620 (setq rest (cdr rest) | |
| 1621 lap (delq lap0 (delq lap1 lap)))) | |
| 1622 (t | |
| 1623 (if (memq (car lap1) byte-goto-always-pop-ops) | |
| 1624 (progn | |
| 1625 (byte-compile-log-lap " %s %s\t-->\t%s" | |
| 1626 lap0 lap1 (cons 'byte-goto (cdr lap1))) | |
| 1627 (setq lap (delq lap0 lap))) | |
| 1628 (byte-compile-log-lap " %s %s\t-->\t%s" lap0 lap1 | |
| 1629 (cons 'byte-goto (cdr lap1)))) | |
| 1630 (setcar lap1 'byte-goto))) | |
| 1631 (setq keep-going t)) | |
| 1632 ;; | |
| 1633 ;; varref-X varref-X --> varref-X dup | |
| 1634 ;; varref-X [dup ...] varref-X --> varref-X [dup ...] dup | |
| 1635 ;; We don't optimize the const-X variations on this here, | |
| 1636 ;; because that would inhibit some goto optimizations; we | |
| 1637 ;; optimize the const-X case after all other optimizations. | |
| 1638 ;; | |
| 1639 ((and (eq 'byte-varref (car lap0)) | |
| 1640 (progn | |
| 1641 (setq tmp (cdr rest)) | |
| 1642 (while (eq (car (car tmp)) 'byte-dup) | |
| 1643 (setq tmp (cdr tmp))) | |
| 1644 t) | |
| 1645 (eq (cdr lap0) (cdr (car tmp))) | |
| 1646 (eq 'byte-varref (car (car tmp)))) | |
| 1647 (if (memq byte-optimize-log '(t byte)) | |
| 1648 (let ((str "")) | |
| 1649 (setq tmp2 (cdr rest)) | |
| 1650 (while (not (eq tmp tmp2)) | |
| 1651 (setq tmp2 (cdr tmp2) | |
| 1652 str (concat str " dup"))) | |
| 1653 (byte-compile-log-lap " %s%s %s\t-->\t%s%s dup" | |
| 1654 lap0 str lap0 lap0 str))) | |
| 1655 (setq keep-going t) | |
| 1656 (setcar (car tmp) 'byte-dup) | |
| 1657 (setcdr (car tmp) 0) | |
| 1658 (setq rest tmp)) | |
| 1659 ;; | |
| 1660 ;; TAG1: TAG2: --> TAG1: <deleted> | |
| 1661 ;; (and other references to TAG2 are replaced with TAG1) | |
| 1662 ;; | |
| 1663 ((and (eq (car lap0) 'TAG) | |
| 1664 (eq (car lap1) 'TAG)) | |
| 1665 (and (memq byte-optimize-log '(t byte)) | |
| 1666 (byte-compile-log " adjacent tags %d and %d merged" | |
| 1667 (nth 1 lap1) (nth 1 lap0))) | |
| 1668 (setq tmp3 lap) | |
| 1669 (while (setq tmp2 (rassq lap0 tmp3)) | |
| 1670 (setcdr tmp2 lap1) | |
| 1671 (setq tmp3 (cdr (memq tmp2 tmp3)))) | |
| 1672 (setq lap (delq lap0 lap) | |
| 1673 keep-going t)) | |
| 1674 ;; | |
| 1675 ;; unused-TAG: --> <deleted> | |
| 1676 ;; | |
| 1677 ((and (eq 'TAG (car lap0)) | |
| 1678 (not (rassq lap0 lap))) | |
| 1679 (and (memq byte-optimize-log '(t byte)) | |
| 1680 (byte-compile-log " unused tag %d removed" (nth 1 lap0))) | |
| 1681 (setq lap (delq lap0 lap) | |
| 1682 keep-going t)) | |
| 1683 ;; | |
| 1684 ;; goto ... --> goto <delete until TAG or end> | |
| 1685 ;; return ... --> return <delete until TAG or end> | |
| 1686 ;; | |
| 1687 ((and (memq (car lap0) '(byte-goto byte-return)) | |
| 1688 (not (memq (car lap1) '(TAG nil)))) | |
| 1689 (setq tmp rest) | |
| 1690 (let ((i 0) | |
| 1691 (opt-p (memq byte-optimize-log '(t lap))) | |
| 1692 str deleted) | |
| 1693 (while (and (setq tmp (cdr tmp)) | |
| 1694 (not (eq 'TAG (car (car tmp))))) | |
| 1695 (if opt-p (setq deleted (cons (car tmp) deleted) | |
| 1696 str (concat str " %s") | |
| 1697 i (1+ i)))) | |
| 1698 (if opt-p | |
| 1699 (let ((tagstr | |
| 1700 (if (eq 'TAG (car (car tmp))) | |
| 1701 (format "%d:" (car (cdr (car tmp)))) | |
| 1702 (or (car tmp) "")))) | |
| 1703 (if (< i 6) | |
| 1704 (apply 'byte-compile-log-lap-1 | |
| 1705 (concat " %s" str | |
| 1706 " %s\t-->\t%s <deleted> %s") | |
| 1707 lap0 | |
| 1708 (nconc (nreverse deleted) | |
| 1709 (list tagstr lap0 tagstr))) | |
| 1710 (byte-compile-log-lap | |
| 1711 " %s <%d unreachable op%s> %s\t-->\t%s <deleted> %s" | |
| 1712 lap0 i (if (= i 1) "" "s") | |
| 1713 tagstr lap0 tagstr)))) | |
| 1714 (rplacd rest tmp)) | |
| 1715 (setq keep-going t)) | |
| 1716 ;; | |
| 1717 ;; <safe-op> unbind --> unbind <safe-op> | |
| 1718 ;; (this may enable other optimizations.) | |
| 1719 ;; | |
| 1720 ((and (eq 'byte-unbind (car lap1)) | |
| 1721 (memq (car lap0) byte-after-unbind-ops)) | |
| 1722 (byte-compile-log-lap " %s %s\t-->\t%s %s" lap0 lap1 lap1 lap0) | |
| 1723 (setcar rest lap1) | |
| 1724 (setcar (cdr rest) lap0) | |
| 1725 (setq keep-going t)) | |
| 1726 ;; | |
| 1727 ;; varbind-X unbind-N --> discard unbind-(N-1) | |
| 1728 ;; save-excursion unbind-N --> unbind-(N-1) | |
| 1729 ;; save-restriction unbind-N --> unbind-(N-1) | |
| 1730 ;; | |
| 1731 ((and (eq 'byte-unbind (car lap1)) | |
| 1732 (memq (car lap0) '(byte-varbind byte-save-excursion | |
| 1733 byte-save-restriction)) | |
| 1734 (< 0 (cdr lap1))) | |
| 1735 (if (zerop (setcdr lap1 (1- (cdr lap1)))) | |
| 1736 (delq lap1 rest)) | |
| 1737 (if (eq (car lap0) 'byte-varbind) | |
| 1738 (setcar rest (cons 'byte-discard 0)) | |
| 1739 (setq lap (delq lap0 lap))) | |
| 1740 (byte-compile-log-lap " %s %s\t-->\t%s %s" | |
| 1741 lap0 (cons (car lap1) (1+ (cdr lap1))) | |
| 1742 (if (eq (car lap0) 'byte-varbind) | |
| 1743 (car rest) | |
| 1744 (car (cdr rest))) | |
| 1745 (if (and (/= 0 (cdr lap1)) | |
| 1746 (eq (car lap0) 'byte-varbind)) | |
| 1747 (car (cdr rest)) | |
| 1748 "")) | |
| 1749 (setq keep-going t)) | |
| 1750 ;; | |
| 1751 ;; goto*-X ... X: goto-Y --> goto*-Y | |
| 1752 ;; goto-X ... X: return --> return | |
| 1753 ;; | |
| 1754 ((and (memq (car lap0) byte-goto-ops) | |
| 1755 (memq (car (setq tmp (nth 1 (memq (cdr lap0) lap)))) | |
| 1756 '(byte-goto byte-return))) | |
| 1757 (cond ((and (not (eq tmp lap0)) | |
| 1758 (or (eq (car lap0) 'byte-goto) | |
| 1759 (eq (car tmp) 'byte-goto))) | |
| 1760 (byte-compile-log-lap " %s [%s]\t-->\t%s" | |
| 1761 (car lap0) tmp tmp) | |
| 1762 (if (eq (car tmp) 'byte-return) | |
| 1763 (setcar lap0 'byte-return)) | |
| 1764 (setcdr lap0 (cdr tmp)) | |
| 1765 (setq keep-going t)))) | |
| 1766 ;; | |
| 1767 ;; goto-*-else-pop X ... X: goto-if-* --> whatever | |
| 1768 ;; goto-*-else-pop X ... X: discard --> whatever | |
| 1769 ;; | |
| 1770 ((and (memq (car lap0) '(byte-goto-if-nil-else-pop | |
| 1771 byte-goto-if-not-nil-else-pop)) | |
| 1772 (memq (car (car (setq tmp (cdr (memq (cdr lap0) lap))))) | |
| 1773 (eval-when-compile | |
| 1774 (cons 'byte-discard byte-conditional-ops))) | |
| 1775 (not (eq lap0 (car tmp)))) | |
| 1776 (setq tmp2 (car tmp)) | |
| 1777 (setq tmp3 (assq (car lap0) '((byte-goto-if-nil-else-pop | |
| 1778 byte-goto-if-nil) | |
| 1779 (byte-goto-if-not-nil-else-pop | |
| 1780 byte-goto-if-not-nil)))) | |
| 1781 (if (memq (car tmp2) tmp3) | |
| 1782 (progn (setcar lap0 (car tmp2)) | |
| 1783 (setcdr lap0 (cdr tmp2)) | |
| 1784 (byte-compile-log-lap " %s-else-pop [%s]\t-->\t%s" | |
| 1785 (car lap0) tmp2 lap0)) | |
| 1786 ;; Get rid of the -else-pop's and jump one step further. | |
| 1787 (or (eq 'TAG (car (nth 1 tmp))) | |
| 1788 (setcdr tmp (cons (byte-compile-make-tag) | |
| 1789 (cdr tmp)))) | |
| 1790 (byte-compile-log-lap " %s [%s]\t-->\t%s <skip>" | |
| 1791 (car lap0) tmp2 (nth 1 tmp3)) | |
| 1792 (setcar lap0 (nth 1 tmp3)) | |
| 1793 (setcdr lap0 (nth 1 tmp))) | |
| 1794 (setq keep-going t)) | |
| 1795 ;; | |
| 1796 ;; const goto-X ... X: goto-if-* --> whatever | |
| 1797 ;; const goto-X ... X: discard --> whatever | |
| 1798 ;; | |
| 1799 ((and (eq (car lap0) 'byte-constant) | |
| 1800 (eq (car lap1) 'byte-goto) | |
| 1801 (memq (car (car (setq tmp (cdr (memq (cdr lap1) lap))))) | |
| 1802 (eval-when-compile | |
| 1803 (cons 'byte-discard byte-conditional-ops))) | |
| 1804 (not (eq lap1 (car tmp)))) | |
| 1805 (setq tmp2 (car tmp)) | |
| 1806 (cond ((memq (car tmp2) | |
| 1807 (if (null (car (cdr lap0))) | |
| 1808 '(byte-goto-if-nil byte-goto-if-nil-else-pop) | |
| 1809 '(byte-goto-if-not-nil | |
| 1810 byte-goto-if-not-nil-else-pop))) | |
| 1811 (byte-compile-log-lap " %s goto [%s]\t-->\t%s %s" | |
| 1812 lap0 tmp2 lap0 tmp2) | |
| 1813 (setcar lap1 (car tmp2)) | |
| 1814 (setcdr lap1 (cdr tmp2)) | |
| 1815 ;; Let next step fix the (const,goto-if*) sequence. | |
| 1816 (setq rest (cons nil rest))) | |
| 1817 (t | |
| 1818 ;; Jump one step further | |
| 1819 (byte-compile-log-lap | |
| 1820 " %s goto [%s]\t-->\t<deleted> goto <skip>" | |
| 1821 lap0 tmp2) | |
| 1822 (or (eq 'TAG (car (nth 1 tmp))) | |
| 1823 (setcdr tmp (cons (byte-compile-make-tag) | |
| 1824 (cdr tmp)))) | |
| 1825 (setcdr lap1 (car (cdr tmp))) | |
| 1826 (setq lap (delq lap0 lap)))) | |
| 1827 (setq keep-going t)) | |
| 1828 ;; | |
| 1829 ;; X: varref-Y ... varset-Y goto-X --> | |
| 1830 ;; X: varref-Y Z: ... dup varset-Y goto-Z | |
| 1831 ;; (varset-X goto-BACK, BACK: varref-X --> copy the varref down.) | |
| 1832 ;; (This is so usual for while loops that it is worth handling). | |
| 1833 ;; | |
| 1834 ((and (eq (car lap1) 'byte-varset) | |
| 1835 (eq (car lap2) 'byte-goto) | |
| 1836 (not (memq (cdr lap2) rest)) ;Backwards jump | |
| 1837 (eq (car (car (setq tmp (cdr (memq (cdr lap2) lap))))) | |
| 1838 'byte-varref) | |
| 1839 (eq (cdr (car tmp)) (cdr lap1)) | |
| 1840 (not (eq (built-in-variable-type (car (cdr lap1))) | |
| 1841 'boolean))) | |
| 1842 ;;(byte-compile-log-lap " Pulled %s to end of loop" (car tmp)) | |
| 1843 (let ((newtag (byte-compile-make-tag))) | |
| 1844 (byte-compile-log-lap | |
| 1845 " %s: %s ... %s %s\t-->\t%s: %s %s: ... %s %s %s" | |
| 1846 (nth 1 (cdr lap2)) (car tmp) | |
| 1847 lap1 lap2 | |
| 1848 (nth 1 (cdr lap2)) (car tmp) | |
| 1849 (nth 1 newtag) 'byte-dup lap1 | |
| 1850 (cons 'byte-goto newtag) | |
| 1851 ) | |
| 1852 (setcdr rest (cons (cons 'byte-dup 0) (cdr rest))) | |
| 1853 (setcdr tmp (cons (setcdr lap2 newtag) (cdr tmp)))) | |
| 1854 (setq add-depth 1) | |
| 1855 (setq keep-going t)) | |
| 1856 ;; | |
| 1857 ;; goto-X Y: ... X: goto-if*-Y --> goto-if-not-*-X+1 Y: | |
| 1858 ;; (This can pull the loop test to the end of the loop) | |
| 1859 ;; | |
| 1860 ((and (eq (car lap0) 'byte-goto) | |
| 1861 (eq (car lap1) 'TAG) | |
| 1862 (eq lap1 | |
| 1863 (cdr (car (setq tmp (cdr (memq (cdr lap0) lap)))))) | |
| 1864 (memq (car (car tmp)) | |
| 1865 '(byte-goto byte-goto-if-nil byte-goto-if-not-nil | |
| 1866 byte-goto-if-nil-else-pop))) | |
| 1867 ;; (byte-compile-log-lap " %s %s, %s %s --> moved conditional" | |
| 1868 ;; lap0 lap1 (cdr lap0) (car tmp)) | |
| 1869 (let ((newtag (byte-compile-make-tag))) | |
| 1870 (byte-compile-log-lap | |
| 1871 "%s %s: ... %s: %s\t-->\t%s ... %s:" | |
| 1872 lap0 (nth 1 lap1) (nth 1 (cdr lap0)) (car tmp) | |
| 1873 (cons (cdr (assq (car (car tmp)) | |
| 1874 '((byte-goto-if-nil . byte-goto-if-not-nil) | |
| 1875 (byte-goto-if-not-nil . byte-goto-if-nil) | |
| 1876 (byte-goto-if-nil-else-pop . | |
| 1877 byte-goto-if-not-nil-else-pop) | |
| 1878 (byte-goto-if-not-nil-else-pop . | |
| 1879 byte-goto-if-nil-else-pop)))) | |
| 1880 newtag) | |
| 1881 | |
| 1882 (nth 1 newtag) | |
| 1883 ) | |
| 1884 (setcdr tmp (cons (setcdr lap0 newtag) (cdr tmp))) | |
| 1885 (if (eq (car (car tmp)) 'byte-goto-if-nil-else-pop) | |
| 1886 ;; We can handle this case but not the -if-not-nil case, | |
| 1887 ;; because we won't know which non-nil constant to push. | |
| 1888 (setcdr rest (cons (cons 'byte-constant | |
| 1889 (byte-compile-get-constant nil)) | |
| 1890 (cdr rest)))) | |
| 1891 (setcar lap0 (nth 1 (memq (car (car tmp)) | |
| 1892 '(byte-goto-if-nil-else-pop | |
| 1893 byte-goto-if-not-nil | |
| 1894 byte-goto-if-nil | |
| 1895 byte-goto-if-not-nil | |
| 1896 byte-goto byte-goto)))) | |
| 1897 ) | |
| 1898 (setq keep-going t)) | |
| 1899 ) | |
| 1900 (setq rest (cdr rest))) | |
| 1901 ) | |
| 1902 ;; Cleanup stage: | |
| 1903 ;; Rebuild byte-compile-constants / byte-compile-variables. | |
| 1904 ;; Simple optimizations that would inhibit other optimizations if they | |
| 1905 ;; were done in the optimizing loop, and optimizations which there is no | |
| 1906 ;; need to do more than once. | |
| 1907 (setq byte-compile-constants nil | |
| 1908 byte-compile-variables nil) | |
| 1909 (setq rest lap) | |
| 1910 (while rest | |
| 1911 (setq lap0 (car rest) | |
| 1912 lap1 (nth 1 rest)) | |
| 1913 (if (memq (car lap0) byte-constref-ops) | |
| 1914 (if (eq (cdr lap0) 'byte-constant) | |
| 1915 (or (memq (cdr lap0) byte-compile-variables) | |
| 1916 (setq byte-compile-variables (cons (cdr lap0) | |
| 1917 byte-compile-variables))) | |
| 1918 (or (memq (cdr lap0) byte-compile-constants) | |
| 1919 (setq byte-compile-constants (cons (cdr lap0) | |
| 1920 byte-compile-constants))))) | |
| 1921 (cond (;; | |
| 1922 ;; const-C varset-X const-C --> const-C dup varset-X | |
| 1923 ;; const-C varbind-X const-C --> const-C dup varbind-X | |
| 1924 ;; | |
| 1925 (and (eq (car lap0) 'byte-constant) | |
| 1926 (eq (car (nth 2 rest)) 'byte-constant) | |
| 1927 (eq (cdr lap0) (car (nth 2 rest))) | |
| 1928 (memq (car lap1) '(byte-varbind byte-varset))) | |
| 1929 (byte-compile-log-lap " %s %s %s\t-->\t%s dup %s" | |
| 1930 lap0 lap1 lap0 lap0 lap1) | |
| 1931 (setcar (cdr (cdr rest)) (cons (car lap1) (cdr lap1))) | |
| 1932 (setcar (cdr rest) (cons 'byte-dup 0)) | |
| 1933 (setq add-depth 1)) | |
| 1934 ;; | |
| 1935 ;; const-X [dup/const-X ...] --> const-X [dup ...] dup | |
| 1936 ;; varref-X [dup/varref-X ...] --> varref-X [dup ...] dup | |
| 1937 ;; | |
| 1938 ((memq (car lap0) '(byte-constant byte-varref)) | |
| 1939 (setq tmp rest | |
| 1940 tmp2 nil) | |
| 1941 (while (progn | |
| 1942 (while (eq 'byte-dup (car (car (setq tmp (cdr tmp)))))) | |
| 1943 (and (eq (cdr lap0) (cdr (car tmp))) | |
| 1944 (eq (car lap0) (car (car tmp))))) | |
| 1945 (setcar tmp (cons 'byte-dup 0)) | |
| 1946 (setq tmp2 t)) | |
| 1947 (if tmp2 | |
| 1948 (byte-compile-log-lap | |
| 1949 " %s [dup/%s]...\t-->\t%s dup..." lap0 lap0 lap0))) | |
| 1950 ;; | |
| 1951 ;; unbind-N unbind-M --> unbind-(N+M) | |
| 1952 ;; | |
| 1953 ((and (eq 'byte-unbind (car lap0)) | |
| 1954 (eq 'byte-unbind (car lap1))) | |
| 1955 (byte-compile-log-lap " %s %s\t-->\t%s" lap0 lap1 | |
| 1956 (cons 'byte-unbind | |
| 1957 (+ (cdr lap0) (cdr lap1)))) | |
| 1958 (setq keep-going t) | |
| 1959 (setq lap (delq lap0 lap)) | |
| 1960 (setcdr lap1 (+ (cdr lap1) (cdr lap0)))) | |
| 1961 ) | |
| 1962 (setq rest (cdr rest))) | |
| 1963 (setq byte-compile-maxdepth (+ byte-compile-maxdepth add-depth))) | |
| 1964 lap) | |
| 1965 | |
| 1966 (provide 'byte-optimize) | |
| 1967 | |
| 1968 | |
| 1969 ;; To avoid "lisp nesting exceeds max-lisp-eval-depth" when this file compiles | |
| 1970 ;; itself, compile some of its most used recursive functions (at load time). | |
| 1971 ;; | |
| 1972 (eval-when-compile | |
| 1973 (or (compiled-function-p (symbol-function 'byte-optimize-form)) | |
| 1974 (assq 'byte-code (symbol-function 'byte-optimize-form)) | |
| 1975 (let ((byte-optimize nil) | |
| 1976 (byte-compile-warnings nil)) | |
| 1977 (mapcar | |
| 1978 #'(lambda (x) | |
| 1979 (or noninteractive (message "compiling %s..." x)) | |
| 1980 (byte-compile x) | |
| 1981 (or noninteractive (message "compiling %s...done" x))) | |
| 1982 '(byte-optimize-form | |
| 1983 byte-optimize-body | |
| 1984 byte-optimize-predicate | |
| 1985 byte-optimize-binary-predicate | |
| 1986 ;; Inserted some more than necessary, to speed it up. | |
| 1987 byte-optimize-form-code-walker | |
| 1988 byte-optimize-lapcode)))) | |
| 1989 nil) | |
| 1990 | |
| 1991 ;;; byte-optimize.el ends here |