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84eb345f | 1 | /* Induction variable canonicalization and loop peeling. |
f1717362 | 2 | Copyright (C) 2004-2016 Free Software Foundation, Inc. |
48e1416a | 3 | |
bb445479 | 4 | This file is part of GCC. |
48e1416a | 5 | |
bb445479 | 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 | |
8c4c00c1 | 8 | Free Software Foundation; either version 3, or (at your option) any |
bb445479 | 9 | later version. |
48e1416a | 10 | |
bb445479 | 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. | |
48e1416a | 15 | |
bb445479 | 16 | You should have received a copy of the GNU General Public License |
8c4c00c1 | 17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
bb445479 | 19 | |
20 | /* This pass detects the loops that iterate a constant number of times, | |
48e1416a | 21 | adds a canonical induction variable (step -1, tested against 0) |
bb445479 | 22 | and replaces the exit test. This enables the less powerful rtl |
23 | level analysis to use this information. | |
24 | ||
25 | This might spoil the code in some cases (by increasing register pressure). | |
26 | Note that in the case the new variable is not needed, ivopts will get rid | |
27 | of it, so it might only be a problem when there are no other linear induction | |
28 | variables. In that case the created optimization possibilities are likely | |
29 | to pay up. | |
30 | ||
c836de3f | 31 | We also perform |
4cf494ec | 32 | - complete unrolling (or peeling) when the loops is rolling few enough |
c836de3f | 33 | times |
34 | - simple peeling (i.e. copying few initial iterations prior the loop) | |
35 | when number of iteration estimate is known (typically by the profile | |
36 | info). */ | |
bb445479 | 37 | |
38 | #include "config.h" | |
39 | #include "system.h" | |
40 | #include "coretypes.h" | |
9ef16211 | 41 | #include "backend.h" |
bb445479 | 42 | #include "tree.h" |
9ef16211 | 43 | #include "gimple.h" |
7c29e30e | 44 | #include "cfghooks.h" |
45 | #include "tree-pass.h" | |
9ef16211 | 46 | #include "ssa.h" |
7c29e30e | 47 | #include "cgraph.h" |
48 | #include "gimple-pretty-print.h" | |
b20a8bb4 | 49 | #include "fold-const.h" |
886c1262 | 50 | #include "profile.h" |
bc61cadb | 51 | #include "gimple-fold.h" |
52 | #include "tree-eh.h" | |
dcf1a1ec | 53 | #include "gimple-iterator.h" |
073c1fd5 | 54 | #include "tree-cfg.h" |
05d9c18a | 55 | #include "tree-ssa-loop-manip.h" |
56 | #include "tree-ssa-loop-niter.h" | |
073c1fd5 | 57 | #include "tree-ssa-loop.h" |
58 | #include "tree-into-ssa.h" | |
bb445479 | 59 | #include "cfgloop.h" |
bb445479 | 60 | #include "tree-chrec.h" |
61 | #include "tree-scalar-evolution.h" | |
62 | #include "params.h" | |
bb445479 | 63 | #include "tree-inline.h" |
424a4a92 | 64 | #include "tree-cfgcleanup.h" |
f7715905 | 65 | #include "builtins.h" |
bb445479 | 66 | |
604f7b8a | 67 | /* Specifies types of loops that may be unrolled. */ |
68 | ||
69 | enum unroll_level | |
70 | { | |
6414dd4c | 71 | UL_SINGLE_ITER, /* Only loops that exit immediately in the first |
604f7b8a | 72 | iteration. */ |
73 | UL_NO_GROWTH, /* Only loops whose unrolling will not cause increase | |
74 | of code size. */ | |
75 | UL_ALL /* All suitable loops. */ | |
76 | }; | |
77 | ||
bb445479 | 78 | /* Adds a canonical induction variable to LOOP iterating NITER times. EXIT |
79 | is the exit edge whose condition is replaced. */ | |
80 | ||
81 | static void | |
82 | create_canonical_iv (struct loop *loop, edge exit, tree niter) | |
83 | { | |
84 | edge in; | |
75a70cf9 | 85 | tree type, var; |
1a91d914 | 86 | gcond *cond; |
75a70cf9 | 87 | gimple_stmt_iterator incr_at; |
bb445479 | 88 | enum tree_code cmp; |
89 | ||
90 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
91 | { | |
92 | fprintf (dump_file, "Added canonical iv to loop %d, ", loop->num); | |
93 | print_generic_expr (dump_file, niter, TDF_SLIM); | |
94 | fprintf (dump_file, " iterations.\n"); | |
95 | } | |
96 | ||
1a91d914 | 97 | cond = as_a <gcond *> (last_stmt (exit->src)); |
cd665a06 | 98 | in = EDGE_SUCC (exit->src, 0); |
bb445479 | 99 | if (in == exit) |
cd665a06 | 100 | in = EDGE_SUCC (exit->src, 1); |
bb445479 | 101 | |
102 | /* Note that we do not need to worry about overflows, since | |
103 | type of niter is always unsigned and all comparisons are | |
104 | just for equality/nonequality -- i.e. everything works | |
105 | with a modulo arithmetics. */ | |
106 | ||
107 | type = TREE_TYPE (niter); | |
49d00087 | 108 | niter = fold_build2 (PLUS_EXPR, type, |
109 | niter, | |
110 | build_int_cst (type, 1)); | |
75a70cf9 | 111 | incr_at = gsi_last_bb (in->src); |
bb445479 | 112 | create_iv (niter, |
3c6185f1 | 113 | build_int_cst (type, -1), |
bb445479 | 114 | NULL_TREE, loop, |
115 | &incr_at, false, NULL, &var); | |
116 | ||
117 | cmp = (exit->flags & EDGE_TRUE_VALUE) ? EQ_EXPR : NE_EXPR; | |
75a70cf9 | 118 | gimple_cond_set_code (cond, cmp); |
119 | gimple_cond_set_lhs (cond, var); | |
120 | gimple_cond_set_rhs (cond, build_int_cst (type, 0)); | |
22aa74c4 | 121 | update_stmt (cond); |
bb445479 | 122 | } |
123 | ||
aa2ba534 | 124 | /* Describe size of loop as detected by tree_estimate_loop_size. */ |
125 | struct loop_size | |
126 | { | |
127 | /* Number of instructions in the loop. */ | |
128 | int overall; | |
129 | ||
130 | /* Number of instructions that will be likely optimized out in | |
131 | peeled iterations of loop (i.e. computation based on induction | |
132 | variable where induction variable starts at known constant.) */ | |
133 | int eliminated_by_peeling; | |
134 | ||
135 | /* Same statistics for last iteration of loop: it is smaller because | |
136 | instructions after exit are not executed. */ | |
137 | int last_iteration; | |
138 | int last_iteration_eliminated_by_peeling; | |
d583c979 | 139 | |
140 | /* If some IV computation will become constant. */ | |
141 | bool constant_iv; | |
142 | ||
143 | /* Number of call stmts that are not a builtin and are pure or const | |
144 | present on the hot path. */ | |
145 | int num_pure_calls_on_hot_path; | |
146 | /* Number of call stmts that are not a builtin and are not pure nor const | |
147 | present on the hot path. */ | |
148 | int num_non_pure_calls_on_hot_path; | |
149 | /* Number of statements other than calls in the loop. */ | |
150 | int non_call_stmts_on_hot_path; | |
151 | /* Number of branches seen on the hot path. */ | |
152 | int num_branches_on_hot_path; | |
aa2ba534 | 153 | }; |
154 | ||
155 | /* Return true if OP in STMT will be constant after peeling LOOP. */ | |
156 | ||
157 | static bool | |
42acab1c | 158 | constant_after_peeling (tree op, gimple *stmt, struct loop *loop) |
aa2ba534 | 159 | { |
160 | affine_iv iv; | |
161 | ||
162 | if (is_gimple_min_invariant (op)) | |
163 | return true; | |
48e1416a | 164 | |
aa2ba534 | 165 | /* We can still fold accesses to constant arrays when index is known. */ |
166 | if (TREE_CODE (op) != SSA_NAME) | |
167 | { | |
168 | tree base = op; | |
169 | ||
170 | /* First make fast look if we see constant array inside. */ | |
171 | while (handled_component_p (base)) | |
172 | base = TREE_OPERAND (base, 0); | |
248022b2 | 173 | if ((DECL_P (base) |
df8d3e89 | 174 | && ctor_for_folding (base) != error_mark_node) |
aa2ba534 | 175 | || CONSTANT_CLASS_P (base)) |
176 | { | |
177 | /* If so, see if we understand all the indices. */ | |
178 | base = op; | |
179 | while (handled_component_p (base)) | |
180 | { | |
181 | if (TREE_CODE (base) == ARRAY_REF | |
182 | && !constant_after_peeling (TREE_OPERAND (base, 1), stmt, loop)) | |
183 | return false; | |
184 | base = TREE_OPERAND (base, 0); | |
185 | } | |
186 | return true; | |
187 | } | |
188 | return false; | |
189 | } | |
190 | ||
191 | /* Induction variables are constants. */ | |
192 | if (!simple_iv (loop, loop_containing_stmt (stmt), op, &iv, false)) | |
193 | return false; | |
194 | if (!is_gimple_min_invariant (iv.base)) | |
195 | return false; | |
196 | if (!is_gimple_min_invariant (iv.step)) | |
197 | return false; | |
198 | return true; | |
199 | } | |
200 | ||
d583c979 | 201 | /* Computes an estimated number of insns in LOOP. |
202 | EXIT (if non-NULL) is an exite edge that will be eliminated in all but last | |
203 | iteration of the loop. | |
204 | EDGE_TO_CANCEL (if non-NULL) is an non-exit edge eliminated in the last iteration | |
205 | of loop. | |
84eb345f | 206 | Return results in SIZE, estimate benefits for complete unrolling exiting by EXIT. |
04437ab6 | 207 | Stop estimating after UPPER_BOUND is met. Return true in this case. */ |
aa2ba534 | 208 | |
84eb345f | 209 | static bool |
f18de397 | 210 | tree_estimate_loop_size (struct loop *loop, edge exit, edge edge_to_cancel, |
211 | struct loop_size *size, int upper_bound) | |
aa2ba534 | 212 | { |
213 | basic_block *body = get_loop_body (loop); | |
214 | gimple_stmt_iterator gsi; | |
215 | unsigned int i; | |
216 | bool after_exit; | |
f1f41a6c | 217 | vec<basic_block> path = get_loop_hot_path (loop); |
aa2ba534 | 218 | |
219 | size->overall = 0; | |
220 | size->eliminated_by_peeling = 0; | |
221 | size->last_iteration = 0; | |
222 | size->last_iteration_eliminated_by_peeling = 0; | |
d583c979 | 223 | size->num_pure_calls_on_hot_path = 0; |
224 | size->num_non_pure_calls_on_hot_path = 0; | |
225 | size->non_call_stmts_on_hot_path = 0; | |
226 | size->num_branches_on_hot_path = 0; | |
227 | size->constant_iv = 0; | |
aa2ba534 | 228 | |
229 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
230 | fprintf (dump_file, "Estimating sizes for loop %i\n", loop->num); | |
231 | for (i = 0; i < loop->num_nodes; i++) | |
232 | { | |
c790d986 | 233 | if (edge_to_cancel && body[i] != edge_to_cancel->src |
234 | && dominated_by_p (CDI_DOMINATORS, body[i], edge_to_cancel->src)) | |
aa2ba534 | 235 | after_exit = true; |
236 | else | |
237 | after_exit = false; | |
238 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
f18de397 | 239 | fprintf (dump_file, " BB: %i, after_exit: %i\n", body[i]->index, |
240 | after_exit); | |
aa2ba534 | 241 | |
242 | for (gsi = gsi_start_bb (body[i]); !gsi_end_p (gsi); gsi_next (&gsi)) | |
243 | { | |
42acab1c | 244 | gimple *stmt = gsi_stmt (gsi); |
aa2ba534 | 245 | int num = estimate_num_insns (stmt, &eni_size_weights); |
246 | bool likely_eliminated = false; | |
d583c979 | 247 | bool likely_eliminated_last = false; |
248 | bool likely_eliminated_peeled = false; | |
aa2ba534 | 249 | |
250 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
251 | { | |
252 | fprintf (dump_file, " size: %3i ", num); | |
253 | print_gimple_stmt (dump_file, gsi_stmt (gsi), 0, 0); | |
254 | } | |
255 | ||
256 | /* Look for reasons why we might optimize this stmt away. */ | |
257 | ||
ae8a8b85 | 258 | if (gimple_has_side_effects (stmt)) |
259 | ; | |
aa2ba534 | 260 | /* Exit conditional. */ |
ae8a8b85 | 261 | else if (exit && body[i] == exit->src |
d583c979 | 262 | && stmt == last_stmt (exit->src)) |
aa2ba534 | 263 | { |
264 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
d583c979 | 265 | fprintf (dump_file, " Exit condition will be eliminated " |
266 | "in peeled copies.\n"); | |
267 | likely_eliminated_peeled = true; | |
268 | } | |
269 | else if (edge_to_cancel && body[i] == edge_to_cancel->src | |
270 | && stmt == last_stmt (edge_to_cancel->src)) | |
271 | { | |
272 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
273 | fprintf (dump_file, " Exit condition will be eliminated " | |
274 | "in last copy.\n"); | |
275 | likely_eliminated_last = true; | |
aa2ba534 | 276 | } |
277 | /* Sets of IV variables */ | |
278 | else if (gimple_code (stmt) == GIMPLE_ASSIGN | |
279 | && constant_after_peeling (gimple_assign_lhs (stmt), stmt, loop)) | |
280 | { | |
281 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
282 | fprintf (dump_file, " Induction variable computation will" | |
283 | " be folded away.\n"); | |
284 | likely_eliminated = true; | |
285 | } | |
286 | /* Assignments of IV variables. */ | |
287 | else if (gimple_code (stmt) == GIMPLE_ASSIGN | |
288 | && TREE_CODE (gimple_assign_lhs (stmt)) == SSA_NAME | |
f18de397 | 289 | && constant_after_peeling (gimple_assign_rhs1 (stmt), stmt, |
290 | loop) | |
aa2ba534 | 291 | && (gimple_assign_rhs_class (stmt) != GIMPLE_BINARY_RHS |
292 | || constant_after_peeling (gimple_assign_rhs2 (stmt), | |
293 | stmt, loop))) | |
294 | { | |
d583c979 | 295 | size->constant_iv = true; |
aa2ba534 | 296 | if (dump_file && (dump_flags & TDF_DETAILS)) |
f18de397 | 297 | fprintf (dump_file, |
298 | " Constant expression will be folded away.\n"); | |
aa2ba534 | 299 | likely_eliminated = true; |
300 | } | |
301 | /* Conditionals. */ | |
d583c979 | 302 | else if ((gimple_code (stmt) == GIMPLE_COND |
f18de397 | 303 | && constant_after_peeling (gimple_cond_lhs (stmt), stmt, |
304 | loop) | |
305 | && constant_after_peeling (gimple_cond_rhs (stmt), stmt, | |
306 | loop) | |
93505d22 | 307 | /* We don't simplify all constant compares so make sure |
308 | they are not both constant already. See PR70288. */ | |
309 | && (! is_gimple_min_invariant (gimple_cond_lhs (stmt)) | |
310 | || ! is_gimple_min_invariant (gimple_cond_rhs (stmt)))) | |
d583c979 | 311 | || (gimple_code (stmt) == GIMPLE_SWITCH |
1a91d914 | 312 | && constant_after_peeling (gimple_switch_index ( |
313 | as_a <gswitch *> (stmt)), | |
93505d22 | 314 | stmt, loop) |
f18de397 | 315 | && ! is_gimple_min_invariant |
316 | (gimple_switch_index (as_a <gswitch *> (stmt))))) | |
aa2ba534 | 317 | { |
318 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
319 | fprintf (dump_file, " Constant conditional.\n"); | |
320 | likely_eliminated = true; | |
321 | } | |
322 | ||
323 | size->overall += num; | |
d583c979 | 324 | if (likely_eliminated || likely_eliminated_peeled) |
aa2ba534 | 325 | size->eliminated_by_peeling += num; |
326 | if (!after_exit) | |
327 | { | |
328 | size->last_iteration += num; | |
d583c979 | 329 | if (likely_eliminated || likely_eliminated_last) |
aa2ba534 | 330 | size->last_iteration_eliminated_by_peeling += num; |
331 | } | |
84eb345f | 332 | if ((size->overall * 3 / 2 - size->eliminated_by_peeling |
333 | - size->last_iteration_eliminated_by_peeling) > upper_bound) | |
334 | { | |
335 | free (body); | |
04437ab6 | 336 | path.release (); |
84eb345f | 337 | return true; |
338 | } | |
aa2ba534 | 339 | } |
340 | } | |
f1f41a6c | 341 | while (path.length ()) |
d583c979 | 342 | { |
f1f41a6c | 343 | basic_block bb = path.pop (); |
d583c979 | 344 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) |
345 | { | |
42acab1c | 346 | gimple *stmt = gsi_stmt (gsi); |
f18de397 | 347 | if (gimple_code (stmt) == GIMPLE_CALL |
348 | && !gimple_inexpensive_call_p (as_a <gcall *> (stmt))) | |
d583c979 | 349 | { |
350 | int flags = gimple_call_flags (stmt); | |
f18de397 | 351 | if (flags & (ECF_PURE | ECF_CONST)) |
d583c979 | 352 | size->num_pure_calls_on_hot_path++; |
353 | else | |
354 | size->num_non_pure_calls_on_hot_path++; | |
355 | size->num_branches_on_hot_path ++; | |
356 | } | |
f18de397 | 357 | /* Count inexpensive calls as non-calls, because they will likely |
358 | expand inline. */ | |
359 | else if (gimple_code (stmt) != GIMPLE_DEBUG) | |
d583c979 | 360 | size->non_call_stmts_on_hot_path++; |
361 | if (((gimple_code (stmt) == GIMPLE_COND | |
362 | && (!constant_after_peeling (gimple_cond_lhs (stmt), stmt, loop) | |
f18de397 | 363 | || constant_after_peeling (gimple_cond_rhs (stmt), stmt, |
364 | loop))) | |
d583c979 | 365 | || (gimple_code (stmt) == GIMPLE_SWITCH |
1a91d914 | 366 | && !constant_after_peeling (gimple_switch_index ( |
367 | as_a <gswitch *> (stmt)), | |
368 | stmt, loop))) | |
d583c979 | 369 | && (!exit || bb != exit->src)) |
370 | size->num_branches_on_hot_path++; | |
371 | } | |
372 | } | |
f1f41a6c | 373 | path.release (); |
aa2ba534 | 374 | if (dump_file && (dump_flags & TDF_DETAILS)) |
375 | fprintf (dump_file, "size: %i-%i, last_iteration: %i-%i\n", size->overall, | |
376 | size->eliminated_by_peeling, size->last_iteration, | |
377 | size->last_iteration_eliminated_by_peeling); | |
48e1416a | 378 | |
aa2ba534 | 379 | free (body); |
84eb345f | 380 | return false; |
aa2ba534 | 381 | } |
604f7b8a | 382 | |
aa2ba534 | 383 | /* Estimate number of insns of completely unrolled loop. |
384 | It is (NUNROLL + 1) * size of loop body with taking into account | |
385 | the fact that in last copy everything after exit conditional | |
386 | is dead and that some instructions will be eliminated after | |
387 | peeling. | |
604f7b8a | 388 | |
c31fb425 | 389 | Loop body is likely going to simplify further, this is difficult |
aa2ba534 | 390 | to guess, we just decrease the result by 1/3. */ |
604f7b8a | 391 | |
392 | static unsigned HOST_WIDE_INT | |
aa2ba534 | 393 | estimated_unrolled_size (struct loop_size *size, |
604f7b8a | 394 | unsigned HOST_WIDE_INT nunroll) |
395 | { | |
aa2ba534 | 396 | HOST_WIDE_INT unr_insns = ((nunroll) |
397 | * (HOST_WIDE_INT) (size->overall | |
398 | - size->eliminated_by_peeling)); | |
399 | if (!nunroll) | |
400 | unr_insns = 0; | |
401 | unr_insns += size->last_iteration - size->last_iteration_eliminated_by_peeling; | |
402 | ||
403 | unr_insns = unr_insns * 2 / 3; | |
604f7b8a | 404 | if (unr_insns <= 0) |
405 | unr_insns = 1; | |
604f7b8a | 406 | |
407 | return unr_insns; | |
408 | } | |
409 | ||
c790d986 | 410 | /* Loop LOOP is known to not loop. See if there is an edge in the loop |
411 | body that can be remove to make the loop to always exit and at | |
412 | the same time it does not make any code potentially executed | |
413 | during the last iteration dead. | |
414 | ||
4cf494ec | 415 | After complete unrolling we still may get rid of the conditional |
c790d986 | 416 | on the exit in the last copy even if we have no idea what it does. |
417 | This is quite common case for loops of form | |
418 | ||
419 | int a[5]; | |
420 | for (i=0;i<b;i++) | |
421 | a[i]=0; | |
422 | ||
423 | Here we prove the loop to iterate 5 times but we do not know | |
424 | it from induction variable. | |
425 | ||
426 | For now we handle only simple case where there is exit condition | |
427 | just before the latch block and the latch block contains no statements | |
428 | with side effect that may otherwise terminate the execution of loop | |
429 | (such as by EH or by terminating the program or longjmp). | |
430 | ||
431 | In the general case we may want to cancel the paths leading to statements | |
432 | loop-niter identified as having undefined effect in the last iteration. | |
433 | The other cases are hopefully rare and will be cleaned up later. */ | |
434 | ||
f86b328b | 435 | static edge |
c790d986 | 436 | loop_edge_to_cancel (struct loop *loop) |
437 | { | |
f1f41a6c | 438 | vec<edge> exits; |
c790d986 | 439 | unsigned i; |
440 | edge edge_to_cancel; | |
441 | gimple_stmt_iterator gsi; | |
442 | ||
443 | /* We want only one predecestor of the loop. */ | |
444 | if (EDGE_COUNT (loop->latch->preds) > 1) | |
445 | return NULL; | |
446 | ||
447 | exits = get_loop_exit_edges (loop); | |
448 | ||
f1f41a6c | 449 | FOR_EACH_VEC_ELT (exits, i, edge_to_cancel) |
c790d986 | 450 | { |
451 | /* Find the other edge than the loop exit | |
452 | leaving the conditoinal. */ | |
453 | if (EDGE_COUNT (edge_to_cancel->src->succs) != 2) | |
454 | continue; | |
455 | if (EDGE_SUCC (edge_to_cancel->src, 0) == edge_to_cancel) | |
456 | edge_to_cancel = EDGE_SUCC (edge_to_cancel->src, 1); | |
457 | else | |
458 | edge_to_cancel = EDGE_SUCC (edge_to_cancel->src, 0); | |
459 | ||
248022b2 | 460 | /* We only can handle conditionals. */ |
461 | if (!(edge_to_cancel->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))) | |
462 | continue; | |
463 | ||
c790d986 | 464 | /* We should never have conditionals in the loop latch. */ |
465 | gcc_assert (edge_to_cancel->dest != loop->header); | |
466 | ||
467 | /* Check that it leads to loop latch. */ | |
468 | if (edge_to_cancel->dest != loop->latch) | |
469 | continue; | |
470 | ||
f1f41a6c | 471 | exits.release (); |
c790d986 | 472 | |
473 | /* Verify that the code in loop latch does nothing that may end program | |
474 | execution without really reaching the exit. This may include | |
475 | non-pure/const function calls, EH statements, volatile ASMs etc. */ | |
476 | for (gsi = gsi_start_bb (loop->latch); !gsi_end_p (gsi); gsi_next (&gsi)) | |
477 | if (gimple_has_side_effects (gsi_stmt (gsi))) | |
478 | return NULL; | |
479 | return edge_to_cancel; | |
480 | } | |
f1f41a6c | 481 | exits.release (); |
c790d986 | 482 | return NULL; |
483 | } | |
484 | ||
72276d01 | 485 | /* Remove all tests for exits that are known to be taken after LOOP was |
486 | peeled NPEELED times. Put gcc_unreachable before every statement | |
487 | known to not be executed. */ | |
488 | ||
489 | static bool | |
490 | remove_exits_and_undefined_stmts (struct loop *loop, unsigned int npeeled) | |
491 | { | |
492 | struct nb_iter_bound *elt; | |
493 | bool changed = false; | |
494 | ||
495 | for (elt = loop->bounds; elt; elt = elt->next) | |
496 | { | |
497 | /* If statement is known to be undefined after peeling, turn it | |
498 | into unreachable (or trap when debugging experience is supposed | |
499 | to be good). */ | |
500 | if (!elt->is_exit | |
796b6678 | 501 | && wi::ltu_p (elt->bound, npeeled)) |
72276d01 | 502 | { |
503 | gimple_stmt_iterator gsi = gsi_for_stmt (elt->stmt); | |
1a91d914 | 504 | gcall *stmt = gimple_build_call |
72276d01 | 505 | (builtin_decl_implicit (BUILT_IN_UNREACHABLE), 0); |
72276d01 | 506 | gimple_set_location (stmt, gimple_location (elt->stmt)); |
507 | gsi_insert_before (&gsi, stmt, GSI_NEW_STMT); | |
3b43af65 | 508 | split_block (gimple_bb (stmt), stmt); |
72276d01 | 509 | changed = true; |
510 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
511 | { | |
512 | fprintf (dump_file, "Forced statement unreachable: "); | |
513 | print_gimple_stmt (dump_file, elt->stmt, 0, 0); | |
514 | } | |
515 | } | |
516 | /* If we know the exit will be taken after peeling, update. */ | |
517 | else if (elt->is_exit | |
796b6678 | 518 | && wi::leu_p (elt->bound, npeeled)) |
72276d01 | 519 | { |
520 | basic_block bb = gimple_bb (elt->stmt); | |
521 | edge exit_edge = EDGE_SUCC (bb, 0); | |
522 | ||
523 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
524 | { | |
525 | fprintf (dump_file, "Forced exit to be taken: "); | |
526 | print_gimple_stmt (dump_file, elt->stmt, 0, 0); | |
527 | } | |
528 | if (!loop_exit_edge_p (loop, exit_edge)) | |
529 | exit_edge = EDGE_SUCC (bb, 1); | |
530 | gcc_checking_assert (loop_exit_edge_p (loop, exit_edge)); | |
1a91d914 | 531 | gcond *cond_stmt = as_a <gcond *> (elt->stmt); |
72276d01 | 532 | if (exit_edge->flags & EDGE_TRUE_VALUE) |
1a91d914 | 533 | gimple_cond_make_true (cond_stmt); |
72276d01 | 534 | else |
1a91d914 | 535 | gimple_cond_make_false (cond_stmt); |
536 | update_stmt (cond_stmt); | |
72276d01 | 537 | changed = true; |
538 | } | |
539 | } | |
540 | return changed; | |
541 | } | |
542 | ||
543 | /* Remove all exits that are known to be never taken because of the loop bound | |
544 | discovered. */ | |
545 | ||
546 | static bool | |
547 | remove_redundant_iv_tests (struct loop *loop) | |
548 | { | |
549 | struct nb_iter_bound *elt; | |
550 | bool changed = false; | |
551 | ||
552 | if (!loop->any_upper_bound) | |
553 | return false; | |
554 | for (elt = loop->bounds; elt; elt = elt->next) | |
555 | { | |
556 | /* Exit is pointless if it won't be taken before loop reaches | |
557 | upper bound. */ | |
558 | if (elt->is_exit && loop->any_upper_bound | |
796b6678 | 559 | && wi::ltu_p (loop->nb_iterations_upper_bound, elt->bound)) |
72276d01 | 560 | { |
561 | basic_block bb = gimple_bb (elt->stmt); | |
562 | edge exit_edge = EDGE_SUCC (bb, 0); | |
563 | struct tree_niter_desc niter; | |
564 | ||
565 | if (!loop_exit_edge_p (loop, exit_edge)) | |
566 | exit_edge = EDGE_SUCC (bb, 1); | |
567 | ||
568 | /* Only when we know the actual number of iterations, not | |
569 | just a bound, we can remove the exit. */ | |
570 | if (!number_of_iterations_exit (loop, exit_edge, | |
3a690dce | 571 | &niter, false, false) |
572 | || !integer_onep (niter.assumptions) | |
72276d01 | 573 | || !integer_zerop (niter.may_be_zero) |
574 | || !niter.niter | |
575 | || TREE_CODE (niter.niter) != INTEGER_CST | |
cd9b5516 | 576 | || !wi::ltu_p (loop->nb_iterations_upper_bound, |
577 | wi::to_widest (niter.niter))) | |
72276d01 | 578 | continue; |
579 | ||
580 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
581 | { | |
582 | fprintf (dump_file, "Removed pointless exit: "); | |
583 | print_gimple_stmt (dump_file, elt->stmt, 0, 0); | |
584 | } | |
1a91d914 | 585 | gcond *cond_stmt = as_a <gcond *> (elt->stmt); |
72276d01 | 586 | if (exit_edge->flags & EDGE_TRUE_VALUE) |
1a91d914 | 587 | gimple_cond_make_false (cond_stmt); |
72276d01 | 588 | else |
1a91d914 | 589 | gimple_cond_make_true (cond_stmt); |
590 | update_stmt (cond_stmt); | |
72276d01 | 591 | changed = true; |
592 | } | |
593 | } | |
594 | return changed; | |
595 | } | |
596 | ||
0cfe7a23 | 597 | /* Stores loops that will be unlooped and edges that will be removed |
598 | after we process whole loop tree. */ | |
f1f41a6c | 599 | static vec<loop_p> loops_to_unloop; |
600 | static vec<int> loops_to_unloop_nunroll; | |
0cfe7a23 | 601 | static vec<edge> edges_to_remove; |
b96f8145 | 602 | /* Stores loops that has been peeled. */ |
603 | static bitmap peeled_loops; | |
72276d01 | 604 | |
605 | /* Cancel all fully unrolled loops by putting __builtin_unreachable | |
606 | on the latch edge. | |
607 | We do it after all unrolling since unlooping moves basic blocks | |
608 | across loop boundaries trashing loop closed SSA form as well | |
609 | as SCEV info needed to be intact during unrolling. | |
610 | ||
c790d986 | 611 | IRRED_INVALIDATED is used to bookkeep if information about |
612 | irreducible regions may become invalid as a result | |
9f0ac045 | 613 | of the transformation. |
614 | LOOP_CLOSED_SSA_INVALIDATED is used to bookkepp the case | |
615 | when we need to go into loop closed SSA form. */ | |
bb445479 | 616 | |
f86b328b | 617 | static void |
72276d01 | 618 | unloop_loops (bitmap loop_closed_ssa_invalidated, |
619 | bool *irred_invalidated) | |
620 | { | |
f1f41a6c | 621 | while (loops_to_unloop.length ()) |
72276d01 | 622 | { |
f1f41a6c | 623 | struct loop *loop = loops_to_unloop.pop (); |
624 | int n_unroll = loops_to_unloop_nunroll.pop (); | |
72276d01 | 625 | basic_block latch = loop->latch; |
626 | edge latch_edge = loop_latch_edge (loop); | |
627 | int flags = latch_edge->flags; | |
628 | location_t locus = latch_edge->goto_locus; | |
1a91d914 | 629 | gcall *stmt; |
72276d01 | 630 | gimple_stmt_iterator gsi; |
631 | ||
632 | remove_exits_and_undefined_stmts (loop, n_unroll); | |
633 | ||
634 | /* Unloop destroys the latch edge. */ | |
635 | unloop (loop, irred_invalidated, loop_closed_ssa_invalidated); | |
636 | ||
637 | /* Create new basic block for the latch edge destination and wire | |
638 | it in. */ | |
639 | stmt = gimple_build_call (builtin_decl_implicit (BUILT_IN_UNREACHABLE), 0); | |
640 | latch_edge = make_edge (latch, create_basic_block (NULL, NULL, latch), flags); | |
641 | latch_edge->probability = 0; | |
642 | latch_edge->count = 0; | |
643 | latch_edge->flags |= flags; | |
644 | latch_edge->goto_locus = locus; | |
645 | ||
646 | latch_edge->dest->loop_father = current_loops->tree_root; | |
647 | latch_edge->dest->count = 0; | |
648 | latch_edge->dest->frequency = 0; | |
649 | set_immediate_dominator (CDI_DOMINATORS, latch_edge->dest, latch_edge->src); | |
650 | ||
651 | gsi = gsi_start_bb (latch_edge->dest); | |
652 | gsi_insert_after (&gsi, stmt, GSI_NEW_STMT); | |
653 | } | |
f1f41a6c | 654 | loops_to_unloop.release (); |
655 | loops_to_unloop_nunroll.release (); | |
be6d8ddc | 656 | |
657 | /* Remove edges in peeled copies. */ | |
658 | unsigned i; | |
659 | edge e; | |
660 | FOR_EACH_VEC_ELT (edges_to_remove, i, e) | |
661 | { | |
662 | bool ok = remove_path (e); | |
663 | gcc_assert (ok); | |
664 | } | |
665 | edges_to_remove.release (); | |
72276d01 | 666 | } |
667 | ||
668 | /* Tries to unroll LOOP completely, i.e. NITER times. | |
669 | UL determines which loops we are allowed to unroll. | |
f55775aa | 670 | EXIT is the exit of the loop that should be eliminated. |
72276d01 | 671 | MAXITER specfy bound on number of iterations, -1 if it is |
f55775aa | 672 | not known or too large for HOST_WIDE_INT. The location |
673 | LOCUS corresponding to the loop is used when emitting | |
674 | a summary of the unroll to the dump file. */ | |
72276d01 | 675 | |
bb445479 | 676 | static bool |
7194de72 | 677 | try_unroll_loop_completely (struct loop *loop, |
bb445479 | 678 | edge exit, tree niter, |
c790d986 | 679 | enum unroll_level ul, |
f55775aa | 680 | HOST_WIDE_INT maxiter, |
681 | location_t locus) | |
bb445479 | 682 | { |
04e3ee8a | 683 | unsigned HOST_WIDE_INT n_unroll = 0, ninsns, unr_insns; |
aa2ba534 | 684 | struct loop_size size; |
c790d986 | 685 | bool n_unroll_found = false; |
c790d986 | 686 | edge edge_to_cancel = NULL; |
c836de3f | 687 | int report_flags = MSG_OPTIMIZED_LOCATIONS | TDF_RTL | TDF_DETAILS; |
bb445479 | 688 | |
c790d986 | 689 | /* See if we proved number of iterations to be low constant. |
bb445479 | 690 | |
c790d986 | 691 | EXIT is an edge that will be removed in all but last iteration of |
692 | the loop. | |
693 | ||
694 | EDGE_TO_CACNEL is an edge that will be removed from the last iteration | |
695 | of the unrolled sequence and is expected to make the final loop not | |
696 | rolling. | |
697 | ||
698 | If the number of execution of loop is determined by standard induction | |
699 | variable test, then EXIT and EDGE_TO_CANCEL are the two edges leaving | |
700 | from the iv test. */ | |
e913b5cd | 701 | if (tree_fits_uhwi_p (niter)) |
c790d986 | 702 | { |
e913b5cd | 703 | n_unroll = tree_to_uhwi (niter); |
c790d986 | 704 | n_unroll_found = true; |
705 | edge_to_cancel = EDGE_SUCC (exit->src, 0); | |
706 | if (edge_to_cancel == exit) | |
707 | edge_to_cancel = EDGE_SUCC (exit->src, 1); | |
708 | } | |
709 | /* We do not know the number of iterations and thus we can not eliminate | |
710 | the EXIT edge. */ | |
711 | else | |
52c6c602 | 712 | exit = NULL; |
c790d986 | 713 | |
714 | /* See if we can improve our estimate by using recorded loop bounds. */ | |
c790d986 | 715 | if (maxiter >= 0 |
716 | && (!n_unroll_found || (unsigned HOST_WIDE_INT)maxiter < n_unroll)) | |
717 | { | |
718 | n_unroll = maxiter; | |
719 | n_unroll_found = true; | |
720 | /* Loop terminates before the IV variable test, so we can not | |
721 | remove it in the last iteration. */ | |
722 | edge_to_cancel = NULL; | |
723 | } | |
724 | ||
725 | if (!n_unroll_found) | |
bb445479 | 726 | return false; |
bb445479 | 727 | |
04e3ee8a | 728 | if (n_unroll > (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEEL_TIMES)) |
729 | { | |
730 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
731 | fprintf (dump_file, "Not unrolling loop %d " | |
2c290da1 | 732 | "(--param max-completely-peel-times limit reached).\n", |
04e3ee8a | 733 | loop->num); |
734 | return false; | |
735 | } | |
bb445479 | 736 | |
c790d986 | 737 | if (!edge_to_cancel) |
738 | edge_to_cancel = loop_edge_to_cancel (loop); | |
739 | ||
bb445479 | 740 | if (n_unroll) |
741 | { | |
c790d986 | 742 | sbitmap wont_exit; |
84eb345f | 743 | bool large; |
604f7b8a | 744 | if (ul == UL_SINGLE_ITER) |
bb445479 | 745 | return false; |
746 | ||
eedd711b | 747 | /* EXIT can be removed only if we are sure it passes first N_UNROLL |
748 | iterations. */ | |
749 | bool remove_exit = (exit && niter | |
750 | && TREE_CODE (niter) == INTEGER_CST | |
751 | && wi::leu_p (n_unroll, wi::to_widest (niter))); | |
752 | ||
84eb345f | 753 | large = tree_estimate_loop_size |
eedd711b | 754 | (loop, remove_exit ? exit : NULL, edge_to_cancel, &size, |
84eb345f | 755 | PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS)); |
aa2ba534 | 756 | ninsns = size.overall; |
84eb345f | 757 | if (large) |
758 | { | |
759 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
760 | fprintf (dump_file, "Not unrolling loop %d: it is too large.\n", | |
761 | loop->num); | |
762 | return false; | |
763 | } | |
bb445479 | 764 | |
aa2ba534 | 765 | unr_insns = estimated_unrolled_size (&size, n_unroll); |
d88fd237 | 766 | if (dump_file && (dump_flags & TDF_DETAILS)) |
767 | { | |
768 | fprintf (dump_file, " Loop size: %d\n", (int) ninsns); | |
769 | fprintf (dump_file, " Estimated size after unrolling: %d\n", | |
770 | (int) unr_insns); | |
771 | } | |
772 | ||
d583c979 | 773 | /* If the code is going to shrink, we don't need to be extra cautious |
774 | on guessing if the unrolling is going to be profitable. */ | |
775 | if (unr_insns | |
776 | /* If there is IV variable that will become constant, we save | |
777 | one instruction in the loop prologue we do not account | |
778 | otherwise. */ | |
779 | <= ninsns + (size.constant_iv != false)) | |
780 | ; | |
c790d986 | 781 | /* We unroll only inner loops, because we do not consider it profitable |
782 | otheriwse. We still can cancel loopback edge of not rolling loop; | |
783 | this is always a good idea. */ | |
d583c979 | 784 | else if (ul == UL_NO_GROWTH) |
785 | { | |
786 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
787 | fprintf (dump_file, "Not unrolling loop %d: size would grow.\n", | |
788 | loop->num); | |
789 | return false; | |
790 | } | |
4cf494ec | 791 | /* Outer loops tend to be less interesting candidates for complete |
d583c979 | 792 | unrolling unless we can do a lot of propagation into the inner loop |
793 | body. For now we disable outer loop unrolling when the code would | |
794 | grow. */ | |
795 | else if (loop->inner) | |
c790d986 | 796 | { |
797 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
d583c979 | 798 | fprintf (dump_file, "Not unrolling loop %d: " |
c790d986 | 799 | "it is not innermost and code would grow.\n", |
800 | loop->num); | |
801 | return false; | |
802 | } | |
d583c979 | 803 | /* If there is call on a hot path through the loop, then |
804 | there is most probably not much to optimize. */ | |
805 | else if (size.num_non_pure_calls_on_hot_path) | |
f00b5e35 | 806 | { |
807 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
d583c979 | 808 | fprintf (dump_file, "Not unrolling loop %d: " |
809 | "contains call and code would grow.\n", | |
f00b5e35 | 810 | loop->num); |
811 | return false; | |
812 | } | |
d583c979 | 813 | /* If there is pure/const call in the function, then we |
814 | can still optimize the unrolled loop body if it contains | |
815 | some other interesting code than the calls and code | |
816 | storing or cumulating the return value. */ | |
817 | else if (size.num_pure_calls_on_hot_path | |
818 | /* One IV increment, one test, one ivtmp store | |
c31fb425 | 819 | and one useful stmt. That is about minimal loop |
d583c979 | 820 | doing pure call. */ |
821 | && (size.non_call_stmts_on_hot_path | |
822 | <= 3 + size.num_pure_calls_on_hot_path)) | |
604f7b8a | 823 | { |
604f7b8a | 824 | if (dump_file && (dump_flags & TDF_DETAILS)) |
d583c979 | 825 | fprintf (dump_file, "Not unrolling loop %d: " |
826 | "contains just pure calls and code would grow.\n", | |
827 | loop->num); | |
828 | return false; | |
829 | } | |
39e9b130 | 830 | /* Complete unrolling is a major win when control flow is removed and |
d583c979 | 831 | one big basic block is created. If the loop contains control flow |
832 | the optimization may still be a win because of eliminating the loop | |
833 | overhead but it also may blow the branch predictor tables. | |
834 | Limit number of branches on the hot path through the peeled | |
835 | sequence. */ | |
836 | else if (size.num_branches_on_hot_path * (int)n_unroll | |
837 | > PARAM_VALUE (PARAM_MAX_PEEL_BRANCHES)) | |
838 | { | |
839 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
840 | fprintf (dump_file, "Not unrolling loop %d: " | |
841 | " number of branches on hot path in the unrolled sequence" | |
842 | " reach --param max-peel-branches limit.\n", | |
843 | loop->num); | |
844 | return false; | |
845 | } | |
846 | else if (unr_insns | |
847 | > (unsigned) PARAM_VALUE (PARAM_MAX_COMPLETELY_PEELED_INSNS)) | |
848 | { | |
849 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
850 | fprintf (dump_file, "Not unrolling loop %d: " | |
851 | "(--param max-completely-peeled-insns limit reached).\n", | |
c790d986 | 852 | loop->num); |
d88fd237 | 853 | return false; |
604f7b8a | 854 | } |
c836de3f | 855 | dump_printf_loc (report_flags, locus, |
856 | "loop turned into non-loop; it never loops.\n"); | |
fb54ef7c | 857 | |
01020a5f | 858 | initialize_original_copy_tables (); |
fb54ef7c | 859 | wont_exit = sbitmap_alloc (n_unroll + 1); |
eedd711b | 860 | if (exit && niter |
861 | && TREE_CODE (niter) == INTEGER_CST | |
862 | && wi::leu_p (n_unroll, wi::to_widest (niter))) | |
863 | { | |
864 | bitmap_ones (wont_exit); | |
865 | if (wi::eq_p (wi::to_widest (niter), n_unroll) | |
866 | || edge_to_cancel) | |
867 | bitmap_clear_bit (wont_exit, 0); | |
868 | } | |
869 | else | |
870 | { | |
871 | exit = NULL; | |
872 | bitmap_clear (wont_exit); | |
873 | } | |
fb54ef7c | 874 | |
75a70cf9 | 875 | if (!gimple_duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
876 | n_unroll, wont_exit, | |
0cfe7a23 | 877 | exit, &edges_to_remove, |
75a70cf9 | 878 | DLTHE_FLAG_UPDATE_FREQ |
879 | | DLTHE_FLAG_COMPLETTE_PEEL)) | |
bb445479 | 880 | { |
01020a5f | 881 | free_original_copy_tables (); |
fb54ef7c | 882 | free (wont_exit); |
d583c979 | 883 | if (dump_file && (dump_flags & TDF_DETAILS)) |
884 | fprintf (dump_file, "Failed to duplicate the loop\n"); | |
bb445479 | 885 | return false; |
886 | } | |
40ffaada | 887 | |
fb54ef7c | 888 | free (wont_exit); |
01020a5f | 889 | free_original_copy_tables (); |
bb445479 | 890 | } |
bb445479 | 891 | |
c790d986 | 892 | /* Remove the conditional from the last copy of the loop. */ |
893 | if (edge_to_cancel) | |
894 | { | |
1a91d914 | 895 | gcond *cond = as_a <gcond *> (last_stmt (edge_to_cancel->src)); |
eedd711b | 896 | force_edge_cold (edge_to_cancel, true); |
c790d986 | 897 | if (edge_to_cancel->flags & EDGE_TRUE_VALUE) |
898 | gimple_cond_make_false (cond); | |
899 | else | |
900 | gimple_cond_make_true (cond); | |
901 | update_stmt (cond); | |
902 | /* Do not remove the path. Doing so may remove outer loop | |
903 | and confuse bookkeeping code in tree_unroll_loops_completelly. */ | |
904 | } | |
c790d986 | 905 | |
72276d01 | 906 | /* Store the loop for later unlooping and exit removal. */ |
f1f41a6c | 907 | loops_to_unloop.safe_push (loop); |
908 | loops_to_unloop_nunroll.safe_push (n_unroll); | |
095dcfa3 | 909 | |
f55775aa | 910 | if (dump_enabled_p ()) |
c790d986 | 911 | { |
912 | if (!n_unroll) | |
f55775aa | 913 | dump_printf_loc (MSG_OPTIMIZED_LOCATIONS | TDF_DETAILS, locus, |
6ee2edad | 914 | "loop turned into non-loop; it never loops\n"); |
c790d986 | 915 | else |
f55775aa | 916 | { |
917 | dump_printf_loc (MSG_OPTIMIZED_LOCATIONS | TDF_DETAILS, locus, | |
6ee2edad | 918 | "loop with %d iterations completely unrolled", |
919 | (int) (n_unroll + 1)); | |
f55775aa | 920 | if (profile_info) |
921 | dump_printf (MSG_OPTIMIZED_LOCATIONS | TDF_DETAILS, | |
922 | " (header execution count %d)", | |
923 | (int)loop->header->count); | |
924 | dump_printf (MSG_OPTIMIZED_LOCATIONS | TDF_DETAILS, "\n"); | |
925 | } | |
926 | } | |
927 | ||
928 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
929 | { | |
c790d986 | 930 | if (exit) |
931 | fprintf (dump_file, "Exit condition of peeled iterations was " | |
932 | "eliminated.\n"); | |
933 | if (edge_to_cancel) | |
934 | fprintf (dump_file, "Last iteration exit edge was proved true.\n"); | |
935 | else | |
936 | fprintf (dump_file, "Latch of last iteration was marked by " | |
937 | "__builtin_unreachable ().\n"); | |
938 | } | |
bb445479 | 939 | |
940 | return true; | |
941 | } | |
942 | ||
c836de3f | 943 | /* Return number of instructions after peeling. */ |
944 | static unsigned HOST_WIDE_INT | |
945 | estimated_peeled_sequence_size (struct loop_size *size, | |
946 | unsigned HOST_WIDE_INT npeel) | |
947 | { | |
948 | return MAX (npeel * (HOST_WIDE_INT) (size->overall | |
949 | - size->eliminated_by_peeling), 1); | |
950 | } | |
951 | ||
952 | /* If the loop is expected to iterate N times and is | |
953 | small enough, duplicate the loop body N+1 times before | |
954 | the loop itself. This way the hot path will never | |
955 | enter the loop. | |
956 | Parameters are the same as for try_unroll_loops_completely */ | |
957 | ||
958 | static bool | |
959 | try_peel_loop (struct loop *loop, | |
960 | edge exit, tree niter, | |
961 | HOST_WIDE_INT maxiter) | |
962 | { | |
39ab2939 | 963 | HOST_WIDE_INT npeel; |
c836de3f | 964 | struct loop_size size; |
965 | int peeled_size; | |
966 | sbitmap wont_exit; | |
c836de3f | 967 | |
b96f8145 | 968 | if (!flag_peel_loops || PARAM_VALUE (PARAM_MAX_PEEL_TIMES) <= 0 |
969 | || !peeled_loops) | |
c836de3f | 970 | return false; |
971 | ||
b96f8145 | 972 | if (bitmap_bit_p (peeled_loops, loop->num)) |
973 | { | |
974 | if (dump_file) | |
975 | fprintf (dump_file, "Not peeling: loop is already peeled\n"); | |
976 | return false; | |
977 | } | |
978 | ||
3ccfbed6 | 979 | /* Peel only innermost loops. |
980 | While the code is perfectly capable of peeling non-innermost loops, | |
981 | the heuristics would probably need some improvements. */ | |
c836de3f | 982 | if (loop->inner) |
983 | { | |
984 | if (dump_file) | |
985 | fprintf (dump_file, "Not peeling: outer loop\n"); | |
986 | return false; | |
987 | } | |
988 | ||
989 | if (!optimize_loop_for_speed_p (loop)) | |
990 | { | |
991 | if (dump_file) | |
992 | fprintf (dump_file, "Not peeling: cold loop\n"); | |
993 | return false; | |
994 | } | |
995 | ||
996 | /* Check if there is an estimate on the number of iterations. */ | |
997 | npeel = estimated_loop_iterations_int (loop); | |
b96f8145 | 998 | if (npeel < 0) |
999 | npeel = likely_max_loop_iterations_int (loop); | |
c836de3f | 1000 | if (npeel < 0) |
1001 | { | |
1002 | if (dump_file) | |
1003 | fprintf (dump_file, "Not peeling: number of iterations is not " | |
1004 | "estimated\n"); | |
1005 | return false; | |
1006 | } | |
1007 | if (maxiter >= 0 && maxiter <= npeel) | |
1008 | { | |
1009 | if (dump_file) | |
1010 | fprintf (dump_file, "Not peeling: upper bound is known so can " | |
4cf494ec | 1011 | "unroll completely\n"); |
c836de3f | 1012 | return false; |
1013 | } | |
1014 | ||
1015 | /* We want to peel estimated number of iterations + 1 (so we never | |
1016 | enter the loop on quick path). Check against PARAM_MAX_PEEL_TIMES | |
1017 | and be sure to avoid overflows. */ | |
1018 | if (npeel > PARAM_VALUE (PARAM_MAX_PEEL_TIMES) - 1) | |
1019 | { | |
1020 | if (dump_file) | |
1021 | fprintf (dump_file, "Not peeling: rolls too much " | |
39ab2939 | 1022 | "(%i + 1 > --param max-peel-times)\n", (int) npeel); |
c836de3f | 1023 | return false; |
1024 | } | |
1025 | npeel++; | |
1026 | ||
1027 | /* Check peeled loops size. */ | |
1028 | tree_estimate_loop_size (loop, exit, NULL, &size, | |
1029 | PARAM_VALUE (PARAM_MAX_PEELED_INSNS)); | |
39ab2939 | 1030 | if ((peeled_size = estimated_peeled_sequence_size (&size, (int) npeel)) |
c836de3f | 1031 | > PARAM_VALUE (PARAM_MAX_PEELED_INSNS)) |
1032 | { | |
1033 | if (dump_file) | |
1034 | fprintf (dump_file, "Not peeling: peeled sequence size is too large " | |
1035 | "(%i insns > --param max-peel-insns)", peeled_size); | |
1036 | return false; | |
1037 | } | |
1038 | ||
1039 | /* Duplicate possibly eliminating the exits. */ | |
1040 | initialize_original_copy_tables (); | |
1041 | wont_exit = sbitmap_alloc (npeel + 1); | |
3ccfbed6 | 1042 | if (exit && niter |
1043 | && TREE_CODE (niter) == INTEGER_CST | |
1044 | && wi::leu_p (npeel, wi::to_widest (niter))) | |
1045 | { | |
1046 | bitmap_ones (wont_exit); | |
b96f8145 | 1047 | bitmap_clear_bit (wont_exit, 0); |
3ccfbed6 | 1048 | } |
1049 | else | |
1050 | { | |
1051 | exit = NULL; | |
1052 | bitmap_clear (wont_exit); | |
1053 | } | |
c836de3f | 1054 | if (!gimple_duplicate_loop_to_header_edge (loop, loop_preheader_edge (loop), |
1055 | npeel, wont_exit, | |
0cfe7a23 | 1056 | exit, &edges_to_remove, |
3ccfbed6 | 1057 | DLTHE_FLAG_UPDATE_FREQ)) |
c836de3f | 1058 | { |
1059 | free_original_copy_tables (); | |
1060 | free (wont_exit); | |
1061 | return false; | |
1062 | } | |
c836de3f | 1063 | free (wont_exit); |
1064 | free_original_copy_tables (); | |
1065 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1066 | { | |
1067 | fprintf (dump_file, "Peeled loop %d, %i times.\n", | |
39ab2939 | 1068 | loop->num, (int) npeel); |
c836de3f | 1069 | } |
3ccfbed6 | 1070 | if (loop->any_estimate) |
1071 | { | |
1072 | if (wi::ltu_p (npeel, loop->nb_iterations_estimate)) | |
1073 | loop->nb_iterations_estimate -= npeel; | |
1074 | else | |
1075 | loop->nb_iterations_estimate = 0; | |
1076 | } | |
c836de3f | 1077 | if (loop->any_upper_bound) |
3ccfbed6 | 1078 | { |
b96f8145 | 1079 | if (wi::ltu_p (npeel, loop->nb_iterations_upper_bound)) |
3ccfbed6 | 1080 | loop->nb_iterations_upper_bound -= npeel; |
1081 | else | |
1082 | loop->nb_iterations_upper_bound = 0; | |
1083 | } | |
8e3ffe30 | 1084 | if (loop->any_likely_upper_bound) |
3ccfbed6 | 1085 | { |
b96f8145 | 1086 | if (wi::ltu_p (npeel, loop->nb_iterations_likely_upper_bound)) |
3ccfbed6 | 1087 | loop->nb_iterations_likely_upper_bound -= npeel; |
1088 | else | |
1089 | { | |
1090 | loop->any_estimate = true; | |
1091 | loop->nb_iterations_estimate = 0; | |
1092 | loop->nb_iterations_likely_upper_bound = 0; | |
1093 | } | |
1094 | } | |
1095 | gcov_type entry_count = 0; | |
1096 | int entry_freq = 0; | |
1097 | ||
0cfe7a23 | 1098 | edge e; |
3ccfbed6 | 1099 | edge_iterator ei; |
1100 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
1101 | if (e->src != loop->latch) | |
1102 | { | |
1103 | entry_count += e->src->count; | |
1104 | entry_freq += e->src->frequency; | |
1105 | gcc_assert (!flow_bb_inside_loop_p (loop, e->src)); | |
1106 | } | |
1107 | int scale = 1; | |
1108 | if (loop->header->count) | |
1109 | scale = RDIV (entry_count * REG_BR_PROB_BASE, loop->header->count); | |
1110 | else if (loop->header->frequency) | |
1111 | scale = RDIV (entry_freq * REG_BR_PROB_BASE, loop->header->frequency); | |
1112 | scale_loop_profile (loop, scale, 0); | |
b96f8145 | 1113 | bitmap_set_bit (peeled_loops, loop->num); |
c836de3f | 1114 | return true; |
1115 | } | |
7194de72 | 1116 | /* Adds a canonical induction variable to LOOP if suitable. |
48e1416a | 1117 | CREATE_IV is true if we may create a new iv. UL determines |
604f7b8a | 1118 | which loops we are allowed to completely unroll. If TRY_EVAL is true, we try |
48e1416a | 1119 | to determine the number of iterations of a loop by direct evaluation. |
72276d01 | 1120 | Returns true if cfg is changed. */ |
bb445479 | 1121 | |
1122 | static bool | |
7194de72 | 1123 | canonicalize_loop_induction_variables (struct loop *loop, |
604f7b8a | 1124 | bool create_iv, enum unroll_level ul, |
72276d01 | 1125 | bool try_eval) |
bb445479 | 1126 | { |
1127 | edge exit = NULL; | |
1128 | tree niter; | |
72276d01 | 1129 | HOST_WIDE_INT maxiter; |
1130 | bool modified = false; | |
f55775aa | 1131 | location_t locus = UNKNOWN_LOCATION; |
bb445479 | 1132 | |
0c3c2e56 | 1133 | niter = number_of_latch_executions (loop); |
f55775aa | 1134 | exit = single_exit (loop); |
bb445479 | 1135 | if (TREE_CODE (niter) == INTEGER_CST) |
f55775aa | 1136 | locus = gimple_location (last_stmt (exit->src)); |
b091dc59 | 1137 | else |
1138 | { | |
1139 | /* If the loop has more than one exit, try checking all of them | |
1140 | for # of iterations determinable through scev. */ | |
f55775aa | 1141 | if (!exit) |
b091dc59 | 1142 | niter = find_loop_niter (loop, &exit); |
1143 | ||
1144 | /* Finally if everything else fails, try brute force evaluation. */ | |
1145 | if (try_eval | |
1146 | && (chrec_contains_undetermined (niter) | |
1147 | || TREE_CODE (niter) != INTEGER_CST)) | |
1148 | niter = find_loop_niter_by_eval (loop, &exit); | |
1149 | ||
f55775aa | 1150 | if (exit) |
1151 | locus = gimple_location (last_stmt (exit->src)); | |
1152 | ||
c790d986 | 1153 | if (TREE_CODE (niter) != INTEGER_CST) |
1154 | exit = NULL; | |
b091dc59 | 1155 | } |
bb445479 | 1156 | |
c790d986 | 1157 | /* We work exceptionally hard here to estimate the bound |
1158 | by find_loop_niter_by_eval. Be sure to keep it for future. */ | |
1159 | if (niter && TREE_CODE (niter) == INTEGER_CST) | |
57337fec | 1160 | { |
5de9d3ed | 1161 | record_niter_bound (loop, wi::to_widest (niter), |
57337fec | 1162 | exit == single_likely_exit (loop), true); |
1163 | } | |
c790d986 | 1164 | |
72276d01 | 1165 | /* Force re-computation of loop bounds so we can remove redundant exits. */ |
1166 | maxiter = max_loop_iterations_int (loop); | |
1167 | ||
c790d986 | 1168 | if (dump_file && (dump_flags & TDF_DETAILS) |
1169 | && TREE_CODE (niter) == INTEGER_CST) | |
bb445479 | 1170 | { |
1171 | fprintf (dump_file, "Loop %d iterates ", loop->num); | |
1172 | print_generic_expr (dump_file, niter, TDF_SLIM); | |
1173 | fprintf (dump_file, " times.\n"); | |
1174 | } | |
c790d986 | 1175 | if (dump_file && (dump_flags & TDF_DETAILS) |
72276d01 | 1176 | && maxiter >= 0) |
c790d986 | 1177 | { |
1178 | fprintf (dump_file, "Loop %d iterates at most %i times.\n", loop->num, | |
72276d01 | 1179 | (int)maxiter); |
c790d986 | 1180 | } |
8e3ffe30 | 1181 | if (dump_file && (dump_flags & TDF_DETAILS) |
1182 | && likely_max_loop_iterations_int (loop) >= 0) | |
1183 | { | |
eedd711b | 1184 | fprintf (dump_file, "Loop %d likely iterates at most %i times.\n", |
1185 | loop->num, (int)likely_max_loop_iterations_int (loop)); | |
8e3ffe30 | 1186 | } |
bb445479 | 1187 | |
72276d01 | 1188 | /* Remove exits that are known to be never taken based on loop bound. |
1189 | Needs to be called after compilation of max_loop_iterations_int that | |
1190 | populates the loop bounds. */ | |
1191 | modified |= remove_redundant_iv_tests (loop); | |
1192 | ||
f55775aa | 1193 | if (try_unroll_loop_completely (loop, exit, niter, ul, maxiter, locus)) |
bb445479 | 1194 | return true; |
1195 | ||
c790d986 | 1196 | if (create_iv |
57337fec | 1197 | && niter && !chrec_contains_undetermined (niter) |
1198 | && exit && just_once_each_iteration_p (loop, exit->src)) | |
bb445479 | 1199 | create_canonical_iv (loop, exit, niter); |
1200 | ||
c836de3f | 1201 | if (ul == UL_ALL) |
1202 | modified |= try_peel_loop (loop, exit, niter, maxiter); | |
1203 | ||
72276d01 | 1204 | return modified; |
bb445479 | 1205 | } |
1206 | ||
1207 | /* The main entry point of the pass. Adds canonical induction variables | |
7194de72 | 1208 | to the suitable loops. */ |
bb445479 | 1209 | |
4c641bf8 | 1210 | unsigned int |
7194de72 | 1211 | canonicalize_induction_variables (void) |
bb445479 | 1212 | { |
bb445479 | 1213 | struct loop *loop; |
053fdd99 | 1214 | bool changed = false; |
c790d986 | 1215 | bool irred_invalidated = false; |
9f0ac045 | 1216 | bitmap loop_closed_ssa_invalidated = BITMAP_ALLOC (NULL); |
48e1416a | 1217 | |
d4f078b5 | 1218 | free_numbers_of_iterations_estimates (cfun); |
72276d01 | 1219 | estimate_numbers_of_iterations (); |
1220 | ||
f21d4d00 | 1221 | FOR_EACH_LOOP (loop, LI_FROM_INNERMOST) |
bb445479 | 1222 | { |
17519ba0 | 1223 | changed |= canonicalize_loop_induction_variables (loop, |
1224 | true, UL_SINGLE_ITER, | |
72276d01 | 1225 | true); |
bb445479 | 1226 | } |
ea1c5c31 | 1227 | gcc_assert (!need_ssa_update_p (cfun)); |
bb445479 | 1228 | |
72276d01 | 1229 | unloop_loops (loop_closed_ssa_invalidated, &irred_invalidated); |
c790d986 | 1230 | if (irred_invalidated |
1231 | && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) | |
1232 | mark_irreducible_loops (); | |
1233 | ||
08162157 | 1234 | /* Clean up the information about numbers of iterations, since brute force |
1235 | evaluation could reveal new information. */ | |
1236 | scev_reset (); | |
1237 | ||
9f0ac045 | 1238 | if (!bitmap_empty_p (loop_closed_ssa_invalidated)) |
1239 | { | |
1240 | gcc_checking_assert (loops_state_satisfies_p (LOOP_CLOSED_SSA)); | |
1241 | rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); | |
1242 | } | |
1243 | BITMAP_FREE (loop_closed_ssa_invalidated); | |
1244 | ||
bb445479 | 1245 | if (changed) |
4c641bf8 | 1246 | return TODO_cleanup_cfg; |
1247 | return 0; | |
bb445479 | 1248 | } |
1249 | ||
2ebfc881 | 1250 | /* Propagate constant SSA_NAMEs defined in basic block BB. */ |
1251 | ||
1252 | static void | |
1253 | propagate_constants_for_unrolling (basic_block bb) | |
1254 | { | |
2ebfc881 | 1255 | /* Look for degenerate PHI nodes with constant argument. */ |
1a91d914 | 1256 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); ) |
2ebfc881 | 1257 | { |
1a91d914 | 1258 | gphi *phi = gsi.phi (); |
2ebfc881 | 1259 | tree result = gimple_phi_result (phi); |
1260 | tree arg = gimple_phi_arg_def (phi, 0); | |
1261 | ||
2eaaa4e7 | 1262 | if (! SSA_NAME_OCCURS_IN_ABNORMAL_PHI (result) |
1263 | && gimple_phi_num_args (phi) == 1 | |
1264 | && TREE_CODE (arg) == INTEGER_CST) | |
2ebfc881 | 1265 | { |
d33914da | 1266 | replace_uses_by (result, arg); |
2ebfc881 | 1267 | gsi_remove (&gsi, true); |
1268 | release_ssa_name (result); | |
1269 | } | |
1270 | else | |
1271 | gsi_next (&gsi); | |
1272 | } | |
1273 | ||
1274 | /* Look for assignments to SSA names with constant RHS. */ | |
1a91d914 | 1275 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) |
2ebfc881 | 1276 | { |
42acab1c | 1277 | gimple *stmt = gsi_stmt (gsi); |
2ebfc881 | 1278 | tree lhs; |
1279 | ||
1280 | if (is_gimple_assign (stmt) | |
fca2aa67 | 1281 | && gimple_assign_rhs_code (stmt) == INTEGER_CST |
2ebfc881 | 1282 | && (lhs = gimple_assign_lhs (stmt), TREE_CODE (lhs) == SSA_NAME) |
fca2aa67 | 1283 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) |
2ebfc881 | 1284 | { |
d33914da | 1285 | replace_uses_by (lhs, gimple_assign_rhs1 (stmt)); |
2ebfc881 | 1286 | gsi_remove (&gsi, true); |
1287 | release_ssa_name (lhs); | |
1288 | } | |
1289 | else | |
1290 | gsi_next (&gsi); | |
1291 | } | |
1292 | } | |
1293 | ||
042301ef | 1294 | /* Process loops from innermost to outer, stopping at the innermost |
1295 | loop we unrolled. */ | |
1296 | ||
1297 | static bool | |
1298 | tree_unroll_loops_completely_1 (bool may_increase_size, bool unroll_outer, | |
0cfe7a23 | 1299 | bitmap father_bbs, struct loop *loop) |
042301ef | 1300 | { |
1301 | struct loop *loop_father; | |
1302 | bool changed = false; | |
1303 | struct loop *inner; | |
1304 | enum unroll_level ul; | |
1305 | ||
1306 | /* Process inner loops first. */ | |
1307 | for (inner = loop->inner; inner != NULL; inner = inner->next) | |
1308 | changed |= tree_unroll_loops_completely_1 (may_increase_size, | |
0cfe7a23 | 1309 | unroll_outer, father_bbs, |
042301ef | 1310 | inner); |
1311 | ||
1312 | /* If we changed an inner loop we cannot process outer loops in this | |
1313 | iteration because SSA form is not up-to-date. Continue with | |
1314 | siblings of outer loops instead. */ | |
1315 | if (changed) | |
1316 | return true; | |
1317 | ||
3d483a94 | 1318 | /* Don't unroll #pragma omp simd loops until the vectorizer |
1319 | attempts to vectorize those. */ | |
4c73695b | 1320 | if (loop->force_vectorize) |
3d483a94 | 1321 | return false; |
1322 | ||
042301ef | 1323 | /* Try to unroll this loop. */ |
1324 | loop_father = loop_outer (loop); | |
1325 | if (!loop_father) | |
1326 | return false; | |
1327 | ||
1328 | if (may_increase_size && optimize_loop_nest_for_speed_p (loop) | |
1329 | /* Unroll outermost loops only if asked to do so or they do | |
1330 | not cause code growth. */ | |
1331 | && (unroll_outer || loop_outer (loop_father))) | |
1332 | ul = UL_ALL; | |
1333 | else | |
1334 | ul = UL_NO_GROWTH; | |
1335 | ||
1336 | if (canonicalize_loop_induction_variables | |
1337 | (loop, false, ul, !flag_tree_loop_ivcanon)) | |
1338 | { | |
1339 | /* If we'll continue unrolling, we need to propagate constants | |
1340 | within the new basic blocks to fold away induction variable | |
1341 | computations; otherwise, the size might blow up before the | |
1342 | iteration is complete and the IR eventually cleaned up. */ | |
0cfe7a23 | 1343 | if (loop_outer (loop_father)) |
1344 | bitmap_set_bit (father_bbs, loop_father->header->index); | |
042301ef | 1345 | |
1346 | return true; | |
1347 | } | |
1348 | ||
1349 | return false; | |
1350 | } | |
1351 | ||
604f7b8a | 1352 | /* Unroll LOOPS completely if they iterate just few times. Unless |
1353 | MAY_INCREASE_SIZE is true, perform the unrolling only if the | |
1354 | size of the code does not increase. */ | |
bb445479 | 1355 | |
4c641bf8 | 1356 | unsigned int |
d88fd237 | 1357 | tree_unroll_loops_completely (bool may_increase_size, bool unroll_outer) |
bb445479 | 1358 | { |
0cfe7a23 | 1359 | bitmap father_bbs = BITMAP_ALLOC (NULL); |
d88fd237 | 1360 | bool changed; |
793a0ab5 | 1361 | int iteration = 0; |
9f0ac045 | 1362 | bool irred_invalidated = false; |
bb445479 | 1363 | |
d88fd237 | 1364 | do |
bb445479 | 1365 | { |
d88fd237 | 1366 | changed = false; |
9f0ac045 | 1367 | bitmap loop_closed_ssa_invalidated = NULL; |
1368 | ||
1369 | if (loops_state_satisfies_p (LOOP_CLOSED_SSA)) | |
1370 | loop_closed_ssa_invalidated = BITMAP_ALLOC (NULL); | |
bb445479 | 1371 | |
d4f078b5 | 1372 | free_numbers_of_iterations_estimates (cfun); |
72276d01 | 1373 | estimate_numbers_of_iterations (); |
1374 | ||
042301ef | 1375 | changed = tree_unroll_loops_completely_1 (may_increase_size, |
0cfe7a23 | 1376 | unroll_outer, father_bbs, |
042301ef | 1377 | current_loops->tree_root); |
d88fd237 | 1378 | if (changed) |
1379 | { | |
2ebfc881 | 1380 | unsigned i; |
1381 | ||
72276d01 | 1382 | unloop_loops (loop_closed_ssa_invalidated, &irred_invalidated); |
c790d986 | 1383 | |
72276d01 | 1384 | /* We can not use TODO_update_ssa_no_phi because VOPS gets confused. */ |
9f0ac045 | 1385 | if (loop_closed_ssa_invalidated |
1386 | && !bitmap_empty_p (loop_closed_ssa_invalidated)) | |
1387 | rewrite_into_loop_closed_ssa (loop_closed_ssa_invalidated, | |
1388 | TODO_update_ssa); | |
1389 | else | |
1390 | update_ssa (TODO_update_ssa); | |
ea1c5c31 | 1391 | |
0cfe7a23 | 1392 | /* father_bbs is a bitmap of loop father header BB indices. |
1393 | Translate that to what non-root loops these BBs belong to now. */ | |
1394 | bitmap_iterator bi; | |
1395 | bitmap fathers = BITMAP_ALLOC (NULL); | |
1396 | EXECUTE_IF_SET_IN_BITMAP (father_bbs, 0, i, bi) | |
1397 | { | |
1398 | basic_block unrolled_loop_bb = BASIC_BLOCK_FOR_FN (cfun, i); | |
1399 | if (! unrolled_loop_bb) | |
1400 | continue; | |
1401 | if (loop_outer (unrolled_loop_bb->loop_father)) | |
1402 | bitmap_set_bit (fathers, | |
1403 | unrolled_loop_bb->loop_father->num); | |
1404 | } | |
1405 | bitmap_clear (father_bbs); | |
2ebfc881 | 1406 | /* Propagate the constants within the new basic blocks. */ |
0cfe7a23 | 1407 | EXECUTE_IF_SET_IN_BITMAP (fathers, 0, i, bi) |
1408 | { | |
1409 | loop_p father = get_loop (cfun, i); | |
1410 | basic_block *body = get_loop_body_in_dom_order (father); | |
1411 | for (unsigned j = 0; j < father->num_nodes; j++) | |
1412 | propagate_constants_for_unrolling (body[j]); | |
1413 | free (body); | |
1414 | } | |
1415 | BITMAP_FREE (fathers); | |
2ebfc881 | 1416 | |
d88fd237 | 1417 | /* This will take care of removing completely unrolled loops |
1418 | from the loop structures so we can continue unrolling now | |
1419 | innermost loops. */ | |
b2a225ba | 1420 | if (cleanup_tree_cfg ()) |
1421 | update_ssa (TODO_update_ssa_only_virtuals); | |
d88fd237 | 1422 | |
1423 | /* Clean up the information about numbers of iterations, since | |
1424 | complete unrolling might have invalidated it. */ | |
1425 | scev_reset (); | |
382ecba7 | 1426 | if (flag_checking && loops_state_satisfies_p (LOOP_CLOSED_SSA)) |
9f0ac045 | 1427 | verify_loop_closed_ssa (true); |
d88fd237 | 1428 | } |
9f0ac045 | 1429 | if (loop_closed_ssa_invalidated) |
1430 | BITMAP_FREE (loop_closed_ssa_invalidated); | |
d88fd237 | 1431 | } |
793a0ab5 | 1432 | while (changed |
1433 | && ++iteration <= PARAM_VALUE (PARAM_MAX_UNROLL_ITERATIONS)); | |
08162157 | 1434 | |
0cfe7a23 | 1435 | BITMAP_FREE (father_bbs); |
2ebfc881 | 1436 | |
9f0ac045 | 1437 | if (irred_invalidated |
1438 | && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) | |
1439 | mark_irreducible_loops (); | |
1440 | ||
4c641bf8 | 1441 | return 0; |
bb445479 | 1442 | } |
f86b328b | 1443 | |
1444 | /* Canonical induction variable creation pass. */ | |
1445 | ||
f86b328b | 1446 | namespace { |
1447 | ||
1448 | const pass_data pass_data_iv_canon = | |
1449 | { | |
1450 | GIMPLE_PASS, /* type */ | |
1451 | "ivcanon", /* name */ | |
1452 | OPTGROUP_LOOP, /* optinfo_flags */ | |
f86b328b | 1453 | TV_TREE_LOOP_IVCANON, /* tv_id */ |
1454 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1455 | 0, /* properties_provided */ | |
1456 | 0, /* properties_destroyed */ | |
1457 | 0, /* todo_flags_start */ | |
1458 | 0, /* todo_flags_finish */ | |
1459 | }; | |
1460 | ||
1461 | class pass_iv_canon : public gimple_opt_pass | |
1462 | { | |
1463 | public: | |
1464 | pass_iv_canon (gcc::context *ctxt) | |
1465 | : gimple_opt_pass (pass_data_iv_canon, ctxt) | |
1466 | {} | |
1467 | ||
1468 | /* opt_pass methods: */ | |
31315c24 | 1469 | virtual bool gate (function *) { return flag_tree_loop_ivcanon != 0; } |
65b0537f | 1470 | virtual unsigned int execute (function *fun); |
f86b328b | 1471 | |
1472 | }; // class pass_iv_canon | |
1473 | ||
65b0537f | 1474 | unsigned int |
1475 | pass_iv_canon::execute (function *fun) | |
1476 | { | |
1477 | if (number_of_loops (fun) <= 1) | |
1478 | return 0; | |
1479 | ||
1480 | return canonicalize_induction_variables (); | |
1481 | } | |
1482 | ||
f86b328b | 1483 | } // anon namespace |
1484 | ||
1485 | gimple_opt_pass * | |
1486 | make_pass_iv_canon (gcc::context *ctxt) | |
1487 | { | |
1488 | return new pass_iv_canon (ctxt); | |
1489 | } | |
1490 | ||
1491 | /* Complete unrolling of loops. */ | |
1492 | ||
f86b328b | 1493 | namespace { |
1494 | ||
1495 | const pass_data pass_data_complete_unroll = | |
1496 | { | |
1497 | GIMPLE_PASS, /* type */ | |
1498 | "cunroll", /* name */ | |
1499 | OPTGROUP_LOOP, /* optinfo_flags */ | |
f86b328b | 1500 | TV_COMPLETE_UNROLL, /* tv_id */ |
1501 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1502 | 0, /* properties_provided */ | |
1503 | 0, /* properties_destroyed */ | |
1504 | 0, /* todo_flags_start */ | |
1505 | 0, /* todo_flags_finish */ | |
1506 | }; | |
1507 | ||
1508 | class pass_complete_unroll : public gimple_opt_pass | |
1509 | { | |
1510 | public: | |
1511 | pass_complete_unroll (gcc::context *ctxt) | |
1512 | : gimple_opt_pass (pass_data_complete_unroll, ctxt) | |
1513 | {} | |
1514 | ||
1515 | /* opt_pass methods: */ | |
65b0537f | 1516 | virtual unsigned int execute (function *); |
f86b328b | 1517 | |
1518 | }; // class pass_complete_unroll | |
1519 | ||
65b0537f | 1520 | unsigned int |
1521 | pass_complete_unroll::execute (function *fun) | |
1522 | { | |
1523 | if (number_of_loops (fun) <= 1) | |
1524 | return 0; | |
1525 | ||
b96f8145 | 1526 | /* If we ever decide to run loop peeling more than once, we will need to |
1527 | track loops already peeled in loop structures themselves to avoid | |
1528 | re-peeling the same loop multiple times. */ | |
1529 | if (flag_peel_loops) | |
1530 | peeled_loops = BITMAP_ALLOC (NULL); | |
1531 | int val = tree_unroll_loops_completely (flag_unroll_loops | |
1532 | || flag_peel_loops | |
1533 | || optimize >= 3, true); | |
1534 | if (peeled_loops) | |
1535 | { | |
1536 | BITMAP_FREE (peeled_loops); | |
1537 | peeled_loops = NULL; | |
1538 | } | |
1539 | return val; | |
65b0537f | 1540 | } |
1541 | ||
f86b328b | 1542 | } // anon namespace |
1543 | ||
1544 | gimple_opt_pass * | |
1545 | make_pass_complete_unroll (gcc::context *ctxt) | |
1546 | { | |
1547 | return new pass_complete_unroll (ctxt); | |
1548 | } | |
1549 | ||
1550 | /* Complete unrolling of inner loops. */ | |
1551 | ||
f86b328b | 1552 | namespace { |
1553 | ||
1554 | const pass_data pass_data_complete_unrolli = | |
1555 | { | |
1556 | GIMPLE_PASS, /* type */ | |
1557 | "cunrolli", /* name */ | |
1558 | OPTGROUP_LOOP, /* optinfo_flags */ | |
f86b328b | 1559 | TV_COMPLETE_UNROLL, /* tv_id */ |
1560 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1561 | 0, /* properties_provided */ | |
1562 | 0, /* properties_destroyed */ | |
1563 | 0, /* todo_flags_start */ | |
8b88439e | 1564 | 0, /* todo_flags_finish */ |
f86b328b | 1565 | }; |
1566 | ||
1567 | class pass_complete_unrolli : public gimple_opt_pass | |
1568 | { | |
1569 | public: | |
1570 | pass_complete_unrolli (gcc::context *ctxt) | |
1571 | : gimple_opt_pass (pass_data_complete_unrolli, ctxt) | |
1572 | {} | |
1573 | ||
1574 | /* opt_pass methods: */ | |
31315c24 | 1575 | virtual bool gate (function *) { return optimize >= 2; } |
65b0537f | 1576 | virtual unsigned int execute (function *); |
f86b328b | 1577 | |
1578 | }; // class pass_complete_unrolli | |
1579 | ||
65b0537f | 1580 | unsigned int |
1581 | pass_complete_unrolli::execute (function *fun) | |
1582 | { | |
1583 | unsigned ret = 0; | |
1584 | ||
1585 | loop_optimizer_init (LOOPS_NORMAL | |
1586 | | LOOPS_HAVE_RECORDED_EXITS); | |
1587 | if (number_of_loops (fun) > 1) | |
1588 | { | |
1589 | scev_initialize (); | |
1590 | ret = tree_unroll_loops_completely (optimize >= 3, false); | |
d4f078b5 | 1591 | free_numbers_of_iterations_estimates (fun); |
65b0537f | 1592 | scev_finalize (); |
1593 | } | |
1594 | loop_optimizer_finalize (); | |
1595 | ||
1596 | return ret; | |
1597 | } | |
1598 | ||
f86b328b | 1599 | } // anon namespace |
1600 | ||
1601 | gimple_opt_pass * | |
1602 | make_pass_complete_unrolli (gcc::context *ctxt) | |
1603 | { | |
1604 | return new pass_complete_unrolli (ctxt); | |
1605 | } | |
1606 | ||
1607 |