1 /* Loop optimizations over tree-ssa.
2 Copyright (C) 2003, 2005 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or (at your option) any
9 later version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the Free
18 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
19 02110-1301, USA. */
20
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "tm.h"
25 #include "tree.h"
26 #include "rtl.h"
27 #include "tm_p.h"
28 #include "hard-reg-set.h"
29 #include "basic-block.h"
30 #include "output.h"
31 #include "diagnostic.h"
32 #include "tree-flow.h"
33 #include "tree-dump.h"
34 #include "tree-pass.h"
35 #include "timevar.h"
36 #include "cfgloop.h"
37 #include "flags.h"
38 #include "tree-inline.h"
39 #include "tree-scalar-evolution.h"
40
41 /* The loop tree currently optimized. */
42
43 struct loops *current_loops = NULL;
44
45 /* Initializes the loop structures. */
46
47 static struct loops *
tree_loop_optimizer_init(void)48 tree_loop_optimizer_init (void)
49 {
50 struct loops *loops;
51
52 loops = loop_optimizer_init (LOOPS_NORMAL
53 | LOOPS_HAVE_MARKED_SINGLE_EXITS);
54
55 if (!loops)
56 return NULL;
57
58 rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa);
59
60 return loops;
61 }
62
63 /* The loop superpass. */
64
65 static bool
gate_tree_loop(void)66 gate_tree_loop (void)
67 {
68 return flag_tree_loop_optimize != 0;
69 }
70
71 struct tree_opt_pass pass_tree_loop =
72 {
73 "loop", /* name */
74 gate_tree_loop, /* gate */
75 NULL, /* execute */
76 NULL, /* sub */
77 NULL, /* next */
78 0, /* static_pass_number */
79 TV_TREE_LOOP, /* tv_id */
80 PROP_cfg, /* properties_required */
81 0, /* properties_provided */
82 0, /* properties_destroyed */
83 TODO_ggc_collect, /* todo_flags_start */
84 TODO_dump_func | TODO_verify_ssa | TODO_ggc_collect, /* todo_flags_finish */
85 0 /* letter */
86 };
87
88 /* Loop optimizer initialization. */
89
90 static unsigned int
tree_ssa_loop_init(void)91 tree_ssa_loop_init (void)
92 {
93 current_loops = tree_loop_optimizer_init ();
94 if (!current_loops)
95 return 0;
96
97 scev_initialize (current_loops);
98 return 0;
99 }
100
101 struct tree_opt_pass pass_tree_loop_init =
102 {
103 "loopinit", /* name */
104 NULL, /* gate */
105 tree_ssa_loop_init, /* execute */
106 NULL, /* sub */
107 NULL, /* next */
108 0, /* static_pass_number */
109 TV_TREE_LOOP_INIT, /* tv_id */
110 PROP_cfg, /* properties_required */
111 0, /* properties_provided */
112 0, /* properties_destroyed */
113 0, /* todo_flags_start */
114 TODO_dump_func | TODO_verify_loops, /* todo_flags_finish */
115 0 /* letter */
116 };
117
118 /* Loop invariant motion pass. */
119
120 static unsigned int
tree_ssa_loop_im(void)121 tree_ssa_loop_im (void)
122 {
123 if (!current_loops)
124 return 0;
125
126 tree_ssa_lim (current_loops);
127 return 0;
128 }
129
130 static bool
gate_tree_ssa_loop_im(void)131 gate_tree_ssa_loop_im (void)
132 {
133 return flag_tree_loop_im != 0;
134 }
135
136 struct tree_opt_pass pass_lim =
137 {
138 "lim", /* name */
139 gate_tree_ssa_loop_im, /* gate */
140 tree_ssa_loop_im, /* execute */
141 NULL, /* sub */
142 NULL, /* next */
143 0, /* static_pass_number */
144 TV_LIM, /* tv_id */
145 PROP_cfg, /* properties_required */
146 0, /* properties_provided */
147 0, /* properties_destroyed */
148 0, /* todo_flags_start */
149 TODO_dump_func | TODO_verify_loops, /* todo_flags_finish */
150 0 /* letter */
151 };
152
153 /* Loop unswitching pass. */
154
155 static unsigned int
tree_ssa_loop_unswitch(void)156 tree_ssa_loop_unswitch (void)
157 {
158 if (!current_loops)
159 return 0;
160
161 return tree_ssa_unswitch_loops (current_loops);
162 }
163
164 static bool
gate_tree_ssa_loop_unswitch(void)165 gate_tree_ssa_loop_unswitch (void)
166 {
167 return flag_unswitch_loops != 0;
168 }
169
170 struct tree_opt_pass pass_tree_unswitch =
171 {
172 "unswitch", /* name */
173 gate_tree_ssa_loop_unswitch, /* gate */
174 tree_ssa_loop_unswitch, /* execute */
175 NULL, /* sub */
176 NULL, /* next */
177 0, /* static_pass_number */
178 TV_TREE_LOOP_UNSWITCH, /* tv_id */
179 PROP_cfg, /* properties_required */
180 0, /* properties_provided */
181 0, /* properties_destroyed */
182 0, /* todo_flags_start */
183 TODO_dump_func | TODO_verify_loops, /* todo_flags_finish */
184 0 /* letter */
185 };
186
187 /* Loop autovectorization. */
188
189 static unsigned int
tree_vectorize(void)190 tree_vectorize (void)
191 {
192 vectorize_loops (current_loops);
193 return 0;
194 }
195
196 static bool
gate_tree_vectorize(void)197 gate_tree_vectorize (void)
198 {
199 return flag_tree_vectorize && current_loops;
200 }
201
202 struct tree_opt_pass pass_vectorize =
203 {
204 "vect", /* name */
205 gate_tree_vectorize, /* gate */
206 tree_vectorize, /* execute */
207 NULL, /* sub */
208 NULL, /* next */
209 0, /* static_pass_number */
210 TV_TREE_VECTORIZATION, /* tv_id */
211 PROP_cfg | PROP_ssa, /* properties_required */
212 0, /* properties_provided */
213 0, /* properties_destroyed */
214 TODO_verify_loops, /* todo_flags_start */
215 TODO_dump_func | TODO_update_ssa, /* todo_flags_finish */
216 0 /* letter */
217 };
218
219 /* Loop nest optimizations. */
220
221 static unsigned int
tree_linear_transform(void)222 tree_linear_transform (void)
223 {
224 if (!current_loops)
225 return 0;
226
227 linear_transform_loops (current_loops);
228 return 0;
229 }
230
231 static bool
gate_tree_linear_transform(void)232 gate_tree_linear_transform (void)
233 {
234 return flag_tree_loop_linear != 0;
235 }
236
237 struct tree_opt_pass pass_linear_transform =
238 {
239 "ltrans", /* name */
240 gate_tree_linear_transform, /* gate */
241 tree_linear_transform, /* execute */
242 NULL, /* sub */
243 NULL, /* next */
244 0, /* static_pass_number */
245 TV_TREE_LINEAR_TRANSFORM, /* tv_id */
246 PROP_cfg | PROP_ssa, /* properties_required */
247 0, /* properties_provided */
248 0, /* properties_destroyed */
249 0, /* todo_flags_start */
250 TODO_dump_func | TODO_verify_loops, /* todo_flags_finish */
251 0 /* letter */
252 };
253
254 /* Canonical induction variable creation pass. */
255
256 static unsigned int
tree_ssa_loop_ivcanon(void)257 tree_ssa_loop_ivcanon (void)
258 {
259 if (!current_loops)
260 return 0;
261
262 return canonicalize_induction_variables (current_loops);
263 }
264
265 static bool
gate_tree_ssa_loop_ivcanon(void)266 gate_tree_ssa_loop_ivcanon (void)
267 {
268 return flag_tree_loop_ivcanon != 0;
269 }
270
271 struct tree_opt_pass pass_iv_canon =
272 {
273 "ivcanon", /* name */
274 gate_tree_ssa_loop_ivcanon, /* gate */
275 tree_ssa_loop_ivcanon, /* execute */
276 NULL, /* sub */
277 NULL, /* next */
278 0, /* static_pass_number */
279 TV_TREE_LOOP_IVCANON, /* tv_id */
280 PROP_cfg | PROP_ssa, /* properties_required */
281 0, /* properties_provided */
282 0, /* properties_destroyed */
283 0, /* todo_flags_start */
284 TODO_dump_func | TODO_verify_loops, /* todo_flags_finish */
285 0 /* letter */
286 };
287
288 /* Propagation of constants using scev. */
289
290 static bool
gate_scev_const_prop(void)291 gate_scev_const_prop (void)
292 {
293 return true;
294 }
295
296 struct tree_opt_pass pass_scev_cprop =
297 {
298 "sccp", /* name */
299 gate_scev_const_prop, /* gate */
300 scev_const_prop, /* execute */
301 NULL, /* sub */
302 NULL, /* next */
303 0, /* static_pass_number */
304 TV_SCEV_CONST, /* tv_id */
305 PROP_cfg | PROP_ssa, /* properties_required */
306 0, /* properties_provided */
307 0, /* properties_destroyed */
308 0, /* todo_flags_start */
309 TODO_dump_func | TODO_cleanup_cfg
310 | TODO_update_ssa_only_virtuals,
311 /* todo_flags_finish */
312 0 /* letter */
313 };
314
315 /* Remove empty loops. */
316
317 static unsigned int
tree_ssa_empty_loop(void)318 tree_ssa_empty_loop (void)
319 {
320 if (!current_loops)
321 return 0;
322
323 return remove_empty_loops (current_loops);
324 }
325
326 struct tree_opt_pass pass_empty_loop =
327 {
328 "empty", /* name */
329 NULL, /* gate */
330 tree_ssa_empty_loop, /* execute */
331 NULL, /* sub */
332 NULL, /* next */
333 0, /* static_pass_number */
334 TV_COMPLETE_UNROLL, /* tv_id */
335 PROP_cfg | PROP_ssa, /* properties_required */
336 0, /* properties_provided */
337 0, /* properties_destroyed */
338 0, /* todo_flags_start */
339 TODO_dump_func | TODO_verify_loops, /* todo_flags_finish */
340 0 /* letter */
341 };
342
343 /* Record bounds on numbers of iterations of loops. */
344
345 static unsigned int
tree_ssa_loop_bounds(void)346 tree_ssa_loop_bounds (void)
347 {
348 if (!current_loops)
349 return 0;
350
351 estimate_numbers_of_iterations (current_loops);
352 scev_reset ();
353 return 0;
354 }
355
356 struct tree_opt_pass pass_record_bounds =
357 {
358 NULL, /* name */
359 NULL, /* gate */
360 tree_ssa_loop_bounds, /* execute */
361 NULL, /* sub */
362 NULL, /* next */
363 0, /* static_pass_number */
364 TV_TREE_LOOP_BOUNDS, /* tv_id */
365 PROP_cfg | PROP_ssa, /* properties_required */
366 0, /* properties_provided */
367 0, /* properties_destroyed */
368 0, /* todo_flags_start */
369 0, /* todo_flags_finish */
370 0 /* letter */
371 };
372
373 /* Complete unrolling of loops. */
374
375 static unsigned int
tree_complete_unroll(void)376 tree_complete_unroll (void)
377 {
378 if (!current_loops)
379 return 0;
380
381 return tree_unroll_loops_completely (current_loops,
382 flag_unroll_loops
383 || flag_peel_loops
384 || optimize >= 3);
385 }
386
387 static bool
gate_tree_complete_unroll(void)388 gate_tree_complete_unroll (void)
389 {
390 return true;
391 }
392
393 struct tree_opt_pass pass_complete_unroll =
394 {
395 "cunroll", /* name */
396 gate_tree_complete_unroll, /* gate */
397 tree_complete_unroll, /* execute */
398 NULL, /* sub */
399 NULL, /* next */
400 0, /* static_pass_number */
401 TV_COMPLETE_UNROLL, /* tv_id */
402 PROP_cfg | PROP_ssa, /* properties_required */
403 0, /* properties_provided */
404 0, /* properties_destroyed */
405 0, /* todo_flags_start */
406 TODO_dump_func | TODO_verify_loops, /* todo_flags_finish */
407 0 /* letter */
408 };
409
410 /* Prefetching. */
411
412 static unsigned int
tree_ssa_loop_prefetch(void)413 tree_ssa_loop_prefetch (void)
414 {
415 if (!current_loops)
416 return 0;
417
418 return tree_ssa_prefetch_arrays (current_loops);
419 }
420
421 static bool
gate_tree_ssa_loop_prefetch(void)422 gate_tree_ssa_loop_prefetch (void)
423 {
424 return flag_prefetch_loop_arrays != 0;
425 }
426
427 struct tree_opt_pass pass_loop_prefetch =
428 {
429 "prefetch", /* name */
430 gate_tree_ssa_loop_prefetch, /* gate */
431 tree_ssa_loop_prefetch, /* execute */
432 NULL, /* sub */
433 NULL, /* next */
434 0, /* static_pass_number */
435 TV_TREE_PREFETCH, /* tv_id */
436 PROP_cfg | PROP_ssa, /* properties_required */
437 0, /* properties_provided */
438 0, /* properties_destroyed */
439 0, /* todo_flags_start */
440 TODO_dump_func | TODO_verify_loops, /* todo_flags_finish */
441 0 /* letter */
442 };
443
444 /* Induction variable optimizations. */
445
446 static unsigned int
tree_ssa_loop_ivopts(void)447 tree_ssa_loop_ivopts (void)
448 {
449 if (!current_loops)
450 return 0;
451
452 tree_ssa_iv_optimize (current_loops);
453 return 0;
454 }
455
456 static bool
gate_tree_ssa_loop_ivopts(void)457 gate_tree_ssa_loop_ivopts (void)
458 {
459 return flag_ivopts != 0;
460 }
461
462 struct tree_opt_pass pass_iv_optimize =
463 {
464 "ivopts", /* name */
465 gate_tree_ssa_loop_ivopts, /* gate */
466 tree_ssa_loop_ivopts, /* execute */
467 NULL, /* sub */
468 NULL, /* next */
469 0, /* static_pass_number */
470 TV_TREE_LOOP_IVOPTS, /* tv_id */
471 PROP_cfg | PROP_ssa, /* properties_required */
472 0, /* properties_provided */
473 0, /* properties_destroyed */
474 0, /* todo_flags_start */
475 TODO_dump_func
476 | TODO_verify_loops
477 | TODO_update_ssa, /* todo_flags_finish */
478 0 /* letter */
479 };
480
481 /* Loop optimizer finalization. */
482
483 static unsigned int
tree_ssa_loop_done(void)484 tree_ssa_loop_done (void)
485 {
486 if (!current_loops)
487 return 0;
488
489 free_numbers_of_iterations_estimates (current_loops);
490 scev_finalize ();
491 loop_optimizer_finalize (current_loops);
492 current_loops = NULL;
493 return 0;
494 }
495
496 struct tree_opt_pass pass_tree_loop_done =
497 {
498 "loopdone", /* name */
499 NULL, /* gate */
500 tree_ssa_loop_done, /* execute */
501 NULL, /* sub */
502 NULL, /* next */
503 0, /* static_pass_number */
504 TV_TREE_LOOP_FINI, /* tv_id */
505 PROP_cfg, /* properties_required */
506 0, /* properties_provided */
507 0, /* properties_destroyed */
508 0, /* todo_flags_start */
509 TODO_cleanup_cfg | TODO_dump_func, /* todo_flags_finish */
510 0 /* letter */
511 };
512