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3d436d2a | 1 | /* Loop manipulation code for GNU compiler. |
d1e082c2 | 2 | Copyright (C) 2002-2013 Free Software Foundation, Inc. |
3d436d2a ZD |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify it under | |
7 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 8 | Software Foundation; either version 3, or (at your option) any later |
3d436d2a ZD |
9 | version. |
10 | ||
11 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 | 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 | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
3d436d2a ZD |
19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
23 | #include "tm.h" | |
24 | #include "rtl.h" | |
3d436d2a ZD |
25 | #include "basic-block.h" |
26 | #include "cfgloop.h" | |
f8bf9252 | 27 | #include "tree-flow.h" |
7ee2468b | 28 | #include "dumpfile.h" |
3d436d2a | 29 | |
d73be268 | 30 | static void copy_loops_to (struct loop **, int, |
d329e058 AJ |
31 | struct loop *); |
32 | static void loop_redirect_edge (edge, basic_block); | |
d47cc544 | 33 | static void remove_bbs (basic_block *, int); |
ed7a4b4b | 34 | static bool rpe_enum_p (const_basic_block, const void *); |
d47cc544 | 35 | static int find_path (edge, basic_block **); |
d73be268 ZD |
36 | static void fix_loop_placements (struct loop *, bool *); |
37 | static bool fix_bb_placement (basic_block); | |
1a7de201 | 38 | static void fix_bb_placements (basic_block, bool *, bitmap); |
3d436d2a | 39 | |
d47cc544 | 40 | /* Checks whether basic block BB is dominated by DATA. */ |
617b465c | 41 | static bool |
ed7a4b4b | 42 | rpe_enum_p (const_basic_block bb, const void *data) |
617b465c | 43 | { |
ed7a4b4b | 44 | return dominated_by_p (CDI_DOMINATORS, bb, (const_basic_block) data); |
617b465c ZD |
45 | } |
46 | ||
598ec7bd ZD |
47 | /* Remove basic blocks BBS. NBBS is the number of the basic blocks. */ |
48 | ||
617b465c | 49 | static void |
d47cc544 | 50 | remove_bbs (basic_block *bbs, int nbbs) |
617b465c ZD |
51 | { |
52 | int i; | |
53 | ||
54 | for (i = 0; i < nbbs; i++) | |
598ec7bd | 55 | delete_basic_block (bbs[i]); |
617b465c ZD |
56 | } |
57 | ||
58 | /* Find path -- i.e. the basic blocks dominated by edge E and put them | |
59 | into array BBS, that will be allocated large enough to contain them. | |
35b07080 ZD |
60 | E->dest must have exactly one predecessor for this to work (it is |
61 | easy to achieve and we do not put it here because we do not want to | |
62 | alter anything by this function). The number of basic blocks in the | |
63 | path is returned. */ | |
617b465c | 64 | static int |
d47cc544 | 65 | find_path (edge e, basic_block **bbs) |
617b465c | 66 | { |
628f6a4e | 67 | gcc_assert (EDGE_COUNT (e->dest->preds) <= 1); |
617b465c ZD |
68 | |
69 | /* Find bbs in the path. */ | |
c302207e | 70 | *bbs = XNEWVEC (basic_block, n_basic_blocks); |
617b465c | 71 | return dfs_enumerate_from (e->dest, 0, rpe_enum_p, *bbs, |
d47cc544 | 72 | n_basic_blocks, e->dest); |
617b465c ZD |
73 | } |
74 | ||
d73be268 | 75 | /* Fix placement of basic block BB inside loop hierarchy -- |
617b465c ZD |
76 | Let L be a loop to that BB belongs. Then every successor of BB must either |
77 | 1) belong to some superloop of loop L, or | |
78 | 2) be a header of loop K such that K->outer is superloop of L | |
79 | Returns true if we had to move BB into other loop to enforce this condition, | |
80 | false if the placement of BB was already correct (provided that placements | |
81 | of its successors are correct). */ | |
82 | static bool | |
d73be268 | 83 | fix_bb_placement (basic_block bb) |
617b465c ZD |
84 | { |
85 | edge e; | |
628f6a4e | 86 | edge_iterator ei; |
d73be268 | 87 | struct loop *loop = current_loops->tree_root, *act; |
617b465c | 88 | |
628f6a4e | 89 | FOR_EACH_EDGE (e, ei, bb->succs) |
617b465c ZD |
90 | { |
91 | if (e->dest == EXIT_BLOCK_PTR) | |
92 | continue; | |
93 | ||
94 | act = e->dest->loop_father; | |
95 | if (act->header == e->dest) | |
9ba025a2 | 96 | act = loop_outer (act); |
617b465c ZD |
97 | |
98 | if (flow_loop_nested_p (loop, act)) | |
99 | loop = act; | |
100 | } | |
101 | ||
102 | if (loop == bb->loop_father) | |
103 | return false; | |
104 | ||
105 | remove_bb_from_loops (bb); | |
106 | add_bb_to_loop (bb, loop); | |
107 | ||
108 | return true; | |
109 | } | |
110 | ||
b4c1c7e3 ZD |
111 | /* Fix placement of LOOP inside loop tree, i.e. find the innermost superloop |
112 | of LOOP to that leads at least one exit edge of LOOP, and set it | |
113 | as the immediate superloop of LOOP. Return true if the immediate superloop | |
114 | of LOOP changed. */ | |
115 | ||
116 | static bool | |
117 | fix_loop_placement (struct loop *loop) | |
118 | { | |
119 | unsigned i; | |
120 | edge e; | |
9771b263 | 121 | vec<edge> exits = get_loop_exit_edges (loop); |
b4c1c7e3 ZD |
122 | struct loop *father = current_loops->tree_root, *act; |
123 | bool ret = false; | |
124 | ||
9771b263 | 125 | FOR_EACH_VEC_ELT (exits, i, e) |
b4c1c7e3 ZD |
126 | { |
127 | act = find_common_loop (loop, e->dest->loop_father); | |
128 | if (flow_loop_nested_p (father, act)) | |
129 | father = act; | |
130 | } | |
131 | ||
9ba025a2 | 132 | if (father != loop_outer (loop)) |
b4c1c7e3 | 133 | { |
9ba025a2 | 134 | for (act = loop_outer (loop); act != father; act = loop_outer (act)) |
b4c1c7e3 ZD |
135 | act->num_nodes -= loop->num_nodes; |
136 | flow_loop_tree_node_remove (loop); | |
137 | flow_loop_tree_node_add (father, loop); | |
138 | ||
139 | /* The exit edges of LOOP no longer exits its original immediate | |
140 | superloops; remove them from the appropriate exit lists. */ | |
9771b263 | 141 | FOR_EACH_VEC_ELT (exits, i, e) |
b4c1c7e3 ZD |
142 | rescan_loop_exit (e, false, false); |
143 | ||
144 | ret = true; | |
145 | } | |
146 | ||
9771b263 | 147 | exits.release (); |
b4c1c7e3 ZD |
148 | return ret; |
149 | } | |
150 | ||
617b465c ZD |
151 | /* Fix placements of basic blocks inside loop hierarchy stored in loops; i.e. |
152 | enforce condition condition stated in description of fix_bb_placement. We | |
153 | start from basic block FROM that had some of its successors removed, so that | |
154 | his placement no longer has to be correct, and iteratively fix placement of | |
155 | its predecessors that may change if placement of FROM changed. Also fix | |
156 | placement of subloops of FROM->loop_father, that might also be altered due | |
4d6922ee | 157 | to this change; the condition for them is similar, except that instead of |
dc14f191 | 158 | successors we consider edges coming out of the loops. |
b8698a0f | 159 | |
dc14f191 | 160 | If the changes may invalidate the information about irreducible regions, |
1a7de201 JH |
161 | IRRED_INVALIDATED is set to true. |
162 | ||
163 | If LOOP_CLOSED_SSA_INVLIDATED is non-zero then all basic blocks with | |
164 | changed loop_father are collected there. */ | |
dc14f191 | 165 | |
617b465c | 166 | static void |
d73be268 | 167 | fix_bb_placements (basic_block from, |
1a7de201 JH |
168 | bool *irred_invalidated, |
169 | bitmap loop_closed_ssa_invalidated) | |
617b465c ZD |
170 | { |
171 | sbitmap in_queue; | |
172 | basic_block *queue, *qtop, *qbeg, *qend; | |
634ee309 | 173 | struct loop *base_loop, *target_loop; |
617b465c ZD |
174 | edge e; |
175 | ||
176 | /* We pass through blocks back-reachable from FROM, testing whether some | |
177 | of their successors moved to outer loop. It may be necessary to | |
178 | iterate several times, but it is finite, as we stop unless we move | |
179 | the basic block up the loop structure. The whole story is a bit | |
180 | more complicated due to presence of subloops, those are moved using | |
181 | fix_loop_placement. */ | |
182 | ||
183 | base_loop = from->loop_father; | |
cec8ac0b ZD |
184 | /* If we are already in the outermost loop, the basic blocks cannot be moved |
185 | outside of it. If FROM is the header of the base loop, it cannot be moved | |
186 | outside of it, either. In both cases, we can end now. */ | |
187 | if (base_loop == current_loops->tree_root | |
188 | || from == base_loop->header) | |
617b465c ZD |
189 | return; |
190 | ||
191 | in_queue = sbitmap_alloc (last_basic_block); | |
f61e445a | 192 | bitmap_clear (in_queue); |
d7c028c0 | 193 | bitmap_set_bit (in_queue, from->index); |
617b465c | 194 | /* Prevent us from going out of the base_loop. */ |
d7c028c0 | 195 | bitmap_set_bit (in_queue, base_loop->header->index); |
617b465c | 196 | |
5ed6ace5 | 197 | queue = XNEWVEC (basic_block, base_loop->num_nodes + 1); |
617b465c ZD |
198 | qtop = queue + base_loop->num_nodes + 1; |
199 | qbeg = queue; | |
200 | qend = queue + 1; | |
201 | *qbeg = from; | |
202 | ||
203 | while (qbeg != qend) | |
204 | { | |
628f6a4e | 205 | edge_iterator ei; |
617b465c ZD |
206 | from = *qbeg; |
207 | qbeg++; | |
208 | if (qbeg == qtop) | |
209 | qbeg = queue; | |
d7c028c0 | 210 | bitmap_clear_bit (in_queue, from->index); |
617b465c ZD |
211 | |
212 | if (from->loop_father->header == from) | |
213 | { | |
214 | /* Subloop header, maybe move the loop upward. */ | |
215 | if (!fix_loop_placement (from->loop_father)) | |
216 | continue; | |
634ee309 | 217 | target_loop = loop_outer (from->loop_father); |
617b465c ZD |
218 | } |
219 | else | |
220 | { | |
221 | /* Ordinary basic block. */ | |
d73be268 | 222 | if (!fix_bb_placement (from)) |
617b465c | 223 | continue; |
1a7de201 JH |
224 | if (loop_closed_ssa_invalidated) |
225 | bitmap_set_bit (loop_closed_ssa_invalidated, from->index); | |
634ee309 | 226 | target_loop = from->loop_father; |
617b465c ZD |
227 | } |
228 | ||
dc14f191 ZD |
229 | FOR_EACH_EDGE (e, ei, from->succs) |
230 | { | |
231 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
232 | *irred_invalidated = true; | |
233 | } | |
234 | ||
617b465c | 235 | /* Something has changed, insert predecessors into queue. */ |
628f6a4e | 236 | FOR_EACH_EDGE (e, ei, from->preds) |
617b465c ZD |
237 | { |
238 | basic_block pred = e->src; | |
239 | struct loop *nca; | |
240 | ||
dc14f191 ZD |
241 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
242 | *irred_invalidated = true; | |
243 | ||
d7c028c0 | 244 | if (bitmap_bit_p (in_queue, pred->index)) |
617b465c ZD |
245 | continue; |
246 | ||
d329e058 | 247 | /* If it is subloop, then it either was not moved, or |
617b465c ZD |
248 | the path up the loop tree from base_loop do not contain |
249 | it. */ | |
250 | nca = find_common_loop (pred->loop_father, base_loop); | |
251 | if (pred->loop_father != base_loop | |
252 | && (nca == base_loop | |
253 | || nca != pred->loop_father)) | |
254 | pred = pred->loop_father->header; | |
634ee309 | 255 | else if (!flow_loop_nested_p (target_loop, pred->loop_father)) |
617b465c | 256 | { |
634ee309 ZD |
257 | /* If PRED is already higher in the loop hierarchy than the |
258 | TARGET_LOOP to that we moved FROM, the change of the position | |
259 | of FROM does not affect the position of PRED, so there is no | |
260 | point in processing it. */ | |
617b465c ZD |
261 | continue; |
262 | } | |
263 | ||
d7c028c0 | 264 | if (bitmap_bit_p (in_queue, pred->index)) |
617b465c ZD |
265 | continue; |
266 | ||
267 | /* Schedule the basic block. */ | |
268 | *qend = pred; | |
269 | qend++; | |
270 | if (qend == qtop) | |
271 | qend = queue; | |
d7c028c0 | 272 | bitmap_set_bit (in_queue, pred->index); |
617b465c ZD |
273 | } |
274 | } | |
275 | free (in_queue); | |
276 | free (queue); | |
277 | } | |
278 | ||
279 | /* Removes path beginning at edge E, i.e. remove basic blocks dominated by E | |
d73be268 ZD |
280 | and update loop structures and dominators. Return true if we were able |
281 | to remove the path, false otherwise (and nothing is affected then). */ | |
617b465c | 282 | bool |
d73be268 | 283 | remove_path (edge e) |
617b465c ZD |
284 | { |
285 | edge ae; | |
66f97d31 | 286 | basic_block *rem_bbs, *bord_bbs, from, bb; |
9771b263 | 287 | vec<basic_block> dom_bbs; |
2f697bc4 | 288 | int i, nrem, n_bord_bbs; |
617b465c | 289 | sbitmap seen; |
14fa2cc0 | 290 | bool irred_invalidated = false; |
06f1716b | 291 | edge_iterator ei; |
56494762 | 292 | struct loop *l, *f; |
617b465c | 293 | |
14fa2cc0 | 294 | if (!can_remove_branch_p (e)) |
35b07080 ZD |
295 | return false; |
296 | ||
dc14f191 ZD |
297 | /* Keep track of whether we need to update information about irreducible |
298 | regions. This is the case if the removed area is a part of the | |
299 | irreducible region, or if the set of basic blocks that belong to a loop | |
300 | that is inside an irreducible region is changed, or if such a loop is | |
301 | removed. */ | |
302 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
303 | irred_invalidated = true; | |
304 | ||
35b07080 ZD |
305 | /* We need to check whether basic blocks are dominated by the edge |
306 | e, but we only have basic block dominators. This is easy to | |
307 | fix -- when e->dest has exactly one predecessor, this corresponds | |
308 | to blocks dominated by e->dest, if not, split the edge. */ | |
c5cbcccf | 309 | if (!single_pred_p (e->dest)) |
598ec7bd | 310 | e = single_pred_edge (split_edge (e)); |
35b07080 ZD |
311 | |
312 | /* It may happen that by removing path we remove one or more loops | |
313 | we belong to. In this case first unloop the loops, then proceed | |
314 | normally. We may assume that e->dest is not a header of any loop, | |
315 | as it now has exactly one predecessor. */ | |
56494762 JH |
316 | for (l = e->src->loop_father; loop_outer (l); l = f) |
317 | { | |
318 | f = loop_outer (l); | |
319 | if (dominated_by_p (CDI_DOMINATORS, l->latch, e->dest)) | |
1a7de201 | 320 | unloop (l, &irred_invalidated, NULL); |
56494762 | 321 | } |
d329e058 | 322 | |
35b07080 | 323 | /* Identify the path. */ |
d47cc544 | 324 | nrem = find_path (e, &rem_bbs); |
617b465c ZD |
325 | |
326 | n_bord_bbs = 0; | |
c302207e | 327 | bord_bbs = XNEWVEC (basic_block, n_basic_blocks); |
617b465c | 328 | seen = sbitmap_alloc (last_basic_block); |
f61e445a | 329 | bitmap_clear (seen); |
617b465c ZD |
330 | |
331 | /* Find "border" hexes -- i.e. those with predecessor in removed path. */ | |
332 | for (i = 0; i < nrem; i++) | |
d7c028c0 | 333 | bitmap_set_bit (seen, rem_bbs[i]->index); |
06f1716b JH |
334 | if (!irred_invalidated) |
335 | FOR_EACH_EDGE (ae, ei, e->src->succs) | |
d7c028c0 | 336 | if (ae != e && ae->dest != EXIT_BLOCK_PTR && !bitmap_bit_p (seen, ae->dest->index) |
06f1716b JH |
337 | && ae->flags & EDGE_IRREDUCIBLE_LOOP) |
338 | irred_invalidated = true; | |
35b07080 | 339 | for (i = 0; i < nrem; i++) |
617b465c | 340 | { |
35b07080 | 341 | bb = rem_bbs[i]; |
628f6a4e | 342 | FOR_EACH_EDGE (ae, ei, rem_bbs[i]->succs) |
d7c028c0 | 343 | if (ae->dest != EXIT_BLOCK_PTR && !bitmap_bit_p (seen, ae->dest->index)) |
35b07080 | 344 | { |
d7c028c0 | 345 | bitmap_set_bit (seen, ae->dest->index); |
35b07080 | 346 | bord_bbs[n_bord_bbs++] = ae->dest; |
b8698a0f | 347 | |
dc14f191 ZD |
348 | if (ae->flags & EDGE_IRREDUCIBLE_LOOP) |
349 | irred_invalidated = true; | |
35b07080 | 350 | } |
617b465c | 351 | } |
617b465c ZD |
352 | |
353 | /* Remove the path. */ | |
354 | from = e->src; | |
14fa2cc0 | 355 | remove_branch (e); |
9771b263 | 356 | dom_bbs.create (0); |
617b465c ZD |
357 | |
358 | /* Cancel loops contained in the path. */ | |
359 | for (i = 0; i < nrem; i++) | |
360 | if (rem_bbs[i]->loop_father->header == rem_bbs[i]) | |
2f697bc4 | 361 | cancel_loop_tree (rem_bbs[i]->loop_father); |
598ec7bd | 362 | |
9b43d37b JJ |
363 | remove_bbs (rem_bbs, nrem); |
364 | free (rem_bbs); | |
365 | ||
35b07080 | 366 | /* Find blocks whose dominators may be affected. */ |
f61e445a | 367 | bitmap_clear (seen); |
617b465c ZD |
368 | for (i = 0; i < n_bord_bbs; i++) |
369 | { | |
d47cc544 | 370 | basic_block ldom; |
617b465c | 371 | |
d47cc544 | 372 | bb = get_immediate_dominator (CDI_DOMINATORS, bord_bbs[i]); |
d7c028c0 | 373 | if (bitmap_bit_p (seen, bb->index)) |
617b465c | 374 | continue; |
d7c028c0 | 375 | bitmap_set_bit (seen, bb->index); |
617b465c | 376 | |
d47cc544 SB |
377 | for (ldom = first_dom_son (CDI_DOMINATORS, bb); |
378 | ldom; | |
379 | ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
380 | if (!dominated_by_p (CDI_DOMINATORS, from, ldom)) | |
9771b263 | 381 | dom_bbs.safe_push (ldom); |
617b465c ZD |
382 | } |
383 | ||
617b465c ZD |
384 | free (seen); |
385 | ||
386 | /* Recount dominators. */ | |
66f97d31 | 387 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, true); |
9771b263 | 388 | dom_bbs.release (); |
35b07080 ZD |
389 | free (bord_bbs); |
390 | ||
617b465c ZD |
391 | /* Fix placements of basic blocks inside loops and the placement of |
392 | loops in the loop tree. */ | |
1a7de201 | 393 | fix_bb_placements (from, &irred_invalidated, NULL); |
d73be268 | 394 | fix_loop_placements (from->loop_father, &irred_invalidated); |
dc14f191 ZD |
395 | |
396 | if (irred_invalidated | |
f87000d0 | 397 | && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
d73be268 | 398 | mark_irreducible_loops (); |
617b465c ZD |
399 | |
400 | return true; | |
401 | } | |
402 | ||
89f8f30f ZD |
403 | /* Creates place for a new LOOP in loops structure. */ |
404 | ||
405 | static void | |
406 | place_new_loop (struct loop *loop) | |
617b465c | 407 | { |
89f8f30f | 408 | loop->num = number_of_loops (); |
9771b263 | 409 | vec_safe_push (current_loops->larray, loop); |
617b465c ZD |
410 | } |
411 | ||
412 | /* Given LOOP structure with filled header and latch, find the body of the | |
d73be268 | 413 | corresponding loop and add it to loops tree. Insert the LOOP as a son of |
598ec7bd ZD |
414 | outer. */ |
415 | ||
89f8f30f | 416 | void |
d73be268 | 417 | add_loop (struct loop *loop, struct loop *outer) |
617b465c ZD |
418 | { |
419 | basic_block *bbs; | |
420 | int i, n; | |
89f8f30f | 421 | struct loop *subloop; |
d24a32a1 ZD |
422 | edge e; |
423 | edge_iterator ei; | |
d329e058 | 424 | |
617b465c | 425 | /* Add it to loop structure. */ |
d73be268 | 426 | place_new_loop (loop); |
598ec7bd | 427 | flow_loop_tree_node_add (outer, loop); |
617b465c ZD |
428 | |
429 | /* Find its nodes. */ | |
89f8f30f ZD |
430 | bbs = XNEWVEC (basic_block, n_basic_blocks); |
431 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks); | |
617b465c ZD |
432 | |
433 | for (i = 0; i < n; i++) | |
598ec7bd | 434 | { |
89f8f30f ZD |
435 | if (bbs[i]->loop_father == outer) |
436 | { | |
437 | remove_bb_from_loops (bbs[i]); | |
438 | add_bb_to_loop (bbs[i], loop); | |
439 | continue; | |
440 | } | |
441 | ||
442 | loop->num_nodes++; | |
443 | ||
444 | /* If we find a direct subloop of OUTER, move it to LOOP. */ | |
445 | subloop = bbs[i]->loop_father; | |
9ba025a2 | 446 | if (loop_outer (subloop) == outer |
89f8f30f ZD |
447 | && subloop->header == bbs[i]) |
448 | { | |
449 | flow_loop_tree_node_remove (subloop); | |
450 | flow_loop_tree_node_add (loop, subloop); | |
451 | } | |
598ec7bd | 452 | } |
617b465c | 453 | |
d24a32a1 ZD |
454 | /* Update the information about loop exit edges. */ |
455 | for (i = 0; i < n; i++) | |
456 | { | |
457 | FOR_EACH_EDGE (e, ei, bbs[i]->succs) | |
458 | { | |
459 | rescan_loop_exit (e, false, false); | |
460 | } | |
461 | } | |
462 | ||
617b465c ZD |
463 | free (bbs); |
464 | } | |
465 | ||
617b465c | 466 | /* Multiply all frequencies in LOOP by NUM/DEN. */ |
6e73e84b | 467 | |
03cb2019 | 468 | void |
d329e058 | 469 | scale_loop_frequencies (struct loop *loop, int num, int den) |
617b465c ZD |
470 | { |
471 | basic_block *bbs; | |
472 | ||
473 | bbs = get_loop_body (loop); | |
33156717 | 474 | scale_bbs_frequencies_int (bbs, loop->num_nodes, num, den); |
617b465c ZD |
475 | free (bbs); |
476 | } | |
477 | ||
6e73e84b JH |
478 | /* Multiply all frequencies in LOOP by SCALE/REG_BR_PROB_BASE. |
479 | If ITERATION_BOUND is non-zero, scale even further if loop is predicted | |
480 | to iterate too many times. */ | |
481 | ||
482 | void | |
7770c9e9 | 483 | scale_loop_profile (struct loop *loop, int scale, gcov_type iteration_bound) |
6e73e84b JH |
484 | { |
485 | gcov_type iterations = expected_loop_iterations_unbounded (loop); | |
486 | edge e; | |
487 | edge_iterator ei; | |
488 | ||
489 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
490 | fprintf (dump_file, ";; Scaling loop %i with scale %f, " | |
491 | "bounding iterations to %i from guessed %i\n", | |
492 | loop->num, (double)scale / REG_BR_PROB_BASE, | |
7770c9e9 | 493 | (int)iteration_bound, (int)iterations); |
6e73e84b JH |
494 | |
495 | /* See if loop is predicted to iterate too many times. */ | |
496 | if (iteration_bound && iterations > 0 | |
497 | && RDIV (iterations * scale, REG_BR_PROB_BASE) > iteration_bound) | |
498 | { | |
499 | /* Fixing loop profile for different trip count is not trivial; the exit | |
500 | probabilities has to be updated to match and frequencies propagated down | |
501 | to the loop body. | |
502 | ||
503 | We fully update only the simple case of loop with single exit that is | |
504 | either from the latch or BB just before latch and leads from BB with | |
505 | simple conditional jump. This is OK for use in vectorizer. */ | |
506 | e = single_exit (loop); | |
507 | if (e) | |
508 | { | |
509 | edge other_e; | |
510 | int freq_delta; | |
511 | gcov_type count_delta; | |
512 | ||
513 | FOR_EACH_EDGE (other_e, ei, e->src->succs) | |
514 | if (!(other_e->flags & (EDGE_ABNORMAL | EDGE_FAKE)) | |
515 | && e != other_e) | |
516 | break; | |
517 | ||
518 | /* Probability of exit must be 1/iterations. */ | |
519 | freq_delta = EDGE_FREQUENCY (e); | |
520 | e->probability = REG_BR_PROB_BASE / iteration_bound; | |
521 | other_e->probability = inverse_probability (e->probability); | |
522 | freq_delta -= EDGE_FREQUENCY (e); | |
523 | ||
524 | /* Adjust counts accordingly. */ | |
525 | count_delta = e->count; | |
526 | e->count = apply_probability (e->src->count, e->probability); | |
527 | other_e->count = apply_probability (e->src->count, other_e->probability); | |
528 | count_delta -= e->count; | |
529 | ||
530 | /* If latch exists, change its frequency and count, since we changed | |
531 | probability of exit. Theoretically we should update everything from | |
532 | source of exit edge to latch, but for vectorizer this is enough. */ | |
533 | if (loop->latch | |
534 | && loop->latch != e->src) | |
535 | { | |
536 | loop->latch->frequency += freq_delta; | |
537 | if (loop->latch->frequency < 0) | |
538 | loop->latch->frequency = 0; | |
539 | loop->latch->count += count_delta; | |
540 | if (loop->latch->count < 0) | |
541 | loop->latch->count = 0; | |
542 | } | |
543 | } | |
544 | ||
545 | /* Roughly speaking we want to reduce the loop body profile by the | |
546 | the difference of loop iterations. We however can do better if | |
547 | we look at the actual profile, if it is available. */ | |
548 | scale = RDIV (iteration_bound * scale, iterations); | |
549 | if (loop->header->count) | |
550 | { | |
551 | gcov_type count_in = 0; | |
552 | ||
553 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
554 | if (e->src != loop->latch) | |
555 | count_in += e->count; | |
556 | ||
557 | if (count_in != 0) | |
558 | scale = RDIV (count_in * iteration_bound * REG_BR_PROB_BASE, loop->header->count); | |
559 | } | |
560 | else if (loop->header->frequency) | |
561 | { | |
562 | int freq_in = 0; | |
563 | ||
564 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
565 | if (e->src != loop->latch) | |
566 | freq_in += EDGE_FREQUENCY (e); | |
567 | ||
568 | if (freq_in != 0) | |
569 | scale = RDIV (freq_in * iteration_bound * REG_BR_PROB_BASE, loop->header->frequency); | |
570 | } | |
571 | if (!scale) | |
572 | scale = 1; | |
573 | } | |
574 | ||
575 | if (scale == REG_BR_PROB_BASE) | |
576 | return; | |
577 | ||
578 | /* Scale the actual probabilities. */ | |
579 | scale_loop_frequencies (loop, scale, REG_BR_PROB_BASE); | |
580 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
581 | fprintf (dump_file, ";; guessed iterations are now %i\n", | |
582 | (int)expected_loop_iterations_unbounded (loop)); | |
583 | } | |
584 | ||
f8bf9252 SP |
585 | /* Recompute dominance information for basic blocks outside LOOP. */ |
586 | ||
587 | static void | |
588 | update_dominators_in_loop (struct loop *loop) | |
589 | { | |
6e1aa848 | 590 | vec<basic_block> dom_bbs = vNULL; |
f8bf9252 SP |
591 | sbitmap seen; |
592 | basic_block *body; | |
593 | unsigned i; | |
594 | ||
595 | seen = sbitmap_alloc (last_basic_block); | |
f61e445a | 596 | bitmap_clear (seen); |
f8bf9252 SP |
597 | body = get_loop_body (loop); |
598 | ||
599 | for (i = 0; i < loop->num_nodes; i++) | |
d7c028c0 | 600 | bitmap_set_bit (seen, body[i]->index); |
f8bf9252 SP |
601 | |
602 | for (i = 0; i < loop->num_nodes; i++) | |
603 | { | |
604 | basic_block ldom; | |
605 | ||
606 | for (ldom = first_dom_son (CDI_DOMINATORS, body[i]); | |
607 | ldom; | |
608 | ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
d7c028c0 | 609 | if (!bitmap_bit_p (seen, ldom->index)) |
f8bf9252 | 610 | { |
d7c028c0 | 611 | bitmap_set_bit (seen, ldom->index); |
9771b263 | 612 | dom_bbs.safe_push (ldom); |
f8bf9252 SP |
613 | } |
614 | } | |
615 | ||
616 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false); | |
617 | free (body); | |
618 | free (seen); | |
9771b263 | 619 | dom_bbs.release (); |
f8bf9252 SP |
620 | } |
621 | ||
622 | /* Creates an if region as shown above. CONDITION is used to create | |
b8698a0f | 623 | the test for the if. |
f8bf9252 SP |
624 | |
625 | | | |
626 | | ------------- ------------- | |
627 | | | pred_bb | | pred_bb | | |
628 | | ------------- ------------- | |
629 | | | | | |
630 | | | | ENTRY_EDGE | |
631 | | | ENTRY_EDGE V | |
632 | | | ====> ------------- | |
633 | | | | cond_bb | | |
634 | | | | CONDITION | | |
635 | | | ------------- | |
636 | | V / \ | |
637 | | ------------- e_false / \ e_true | |
638 | | | succ_bb | V V | |
639 | | ------------- ----------- ----------- | |
640 | | | false_bb | | true_bb | | |
641 | | ----------- ----------- | |
642 | | \ / | |
643 | | \ / | |
644 | | V V | |
645 | | ------------- | |
646 | | | join_bb | | |
647 | | ------------- | |
648 | | | exit_edge (result) | |
649 | | V | |
650 | | ----------- | |
651 | | | succ_bb | | |
652 | | ----------- | |
653 | | | |
654 | */ | |
655 | ||
656 | edge | |
657 | create_empty_if_region_on_edge (edge entry_edge, tree condition) | |
658 | { | |
659 | ||
f1ed99cd | 660 | basic_block cond_bb, true_bb, false_bb, join_bb; |
f8bf9252 SP |
661 | edge e_true, e_false, exit_edge; |
662 | gimple cond_stmt; | |
663 | tree simple_cond; | |
664 | gimple_stmt_iterator gsi; | |
665 | ||
f8bf9252 | 666 | cond_bb = split_edge (entry_edge); |
b8698a0f | 667 | |
f8bf9252 SP |
668 | /* Insert condition in cond_bb. */ |
669 | gsi = gsi_last_bb (cond_bb); | |
670 | simple_cond = | |
671 | force_gimple_operand_gsi (&gsi, condition, true, NULL, | |
672 | false, GSI_NEW_STMT); | |
673 | cond_stmt = gimple_build_cond_from_tree (simple_cond, NULL_TREE, NULL_TREE); | |
674 | gsi = gsi_last_bb (cond_bb); | |
675 | gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT); | |
b8698a0f | 676 | |
f8bf9252 SP |
677 | join_bb = split_edge (single_succ_edge (cond_bb)); |
678 | ||
679 | e_true = single_succ_edge (cond_bb); | |
680 | true_bb = split_edge (e_true); | |
681 | ||
682 | e_false = make_edge (cond_bb, join_bb, 0); | |
683 | false_bb = split_edge (e_false); | |
684 | ||
685 | e_true->flags &= ~EDGE_FALLTHRU; | |
686 | e_true->flags |= EDGE_TRUE_VALUE; | |
687 | e_false->flags &= ~EDGE_FALLTHRU; | |
688 | e_false->flags |= EDGE_FALSE_VALUE; | |
689 | ||
690 | set_immediate_dominator (CDI_DOMINATORS, cond_bb, entry_edge->src); | |
691 | set_immediate_dominator (CDI_DOMINATORS, true_bb, cond_bb); | |
692 | set_immediate_dominator (CDI_DOMINATORS, false_bb, cond_bb); | |
693 | set_immediate_dominator (CDI_DOMINATORS, join_bb, cond_bb); | |
694 | ||
695 | exit_edge = single_succ_edge (join_bb); | |
696 | ||
697 | if (single_pred_p (exit_edge->dest)) | |
698 | set_immediate_dominator (CDI_DOMINATORS, exit_edge->dest, join_bb); | |
699 | ||
700 | return exit_edge; | |
701 | } | |
702 | ||
703 | /* create_empty_loop_on_edge | |
704 | | | |
8e74b397 SP |
705 | | - pred_bb - ------ pred_bb ------ |
706 | | | | | iv0 = initial_value | | |
707 | | -----|----- ---------|----------- | |
708 | | | ______ | entry_edge | |
709 | | | entry_edge / | | | |
710 | | | ====> | -V---V- loop_header ------------- | |
711 | | V | | iv_before = phi (iv0, iv_after) | | |
712 | | - succ_bb - | ---|----------------------------- | |
713 | | | | | | | |
714 | | ----------- | ---V--- loop_body --------------- | |
715 | | | | iv_after = iv_before + stride | | |
45e76e9f | 716 | | | | if (iv_before < upper_bound) | |
8e74b397 SP |
717 | | | ---|--------------\-------------- |
718 | | | | \ exit_e | |
719 | | | V \ | |
720 | | | - loop_latch - V- succ_bb - | |
721 | | | | | | | | |
722 | | | /------------- ----------- | |
723 | | \ ___ / | |
f8bf9252 SP |
724 | |
725 | Creates an empty loop as shown above, the IV_BEFORE is the SSA_NAME | |
45e76e9f | 726 | that is used before the increment of IV. IV_BEFORE should be used for |
f8bf9252 | 727 | adding code to the body that uses the IV. OUTER is the outer loop in |
45e76e9f | 728 | which the new loop should be inserted. |
8e74b397 SP |
729 | |
730 | Both INITIAL_VALUE and UPPER_BOUND expressions are gimplified and | |
731 | inserted on the loop entry edge. This implies that this function | |
732 | should be used only when the UPPER_BOUND expression is a loop | |
733 | invariant. */ | |
f8bf9252 SP |
734 | |
735 | struct loop * | |
45e76e9f | 736 | create_empty_loop_on_edge (edge entry_edge, |
f8bf9252 SP |
737 | tree initial_value, |
738 | tree stride, tree upper_bound, | |
739 | tree iv, | |
740 | tree *iv_before, | |
8e74b397 | 741 | tree *iv_after, |
f8bf9252 SP |
742 | struct loop *outer) |
743 | { | |
744 | basic_block loop_header, loop_latch, succ_bb, pred_bb; | |
745 | struct loop *loop; | |
f8bf9252 | 746 | gimple_stmt_iterator gsi; |
f8bf9252 SP |
747 | gimple_seq stmts; |
748 | gimple cond_expr; | |
749 | tree exit_test; | |
750 | edge exit_e; | |
751 | int prob; | |
45e76e9f | 752 | |
f8bf9252 SP |
753 | gcc_assert (entry_edge && initial_value && stride && upper_bound && iv); |
754 | ||
755 | /* Create header, latch and wire up the loop. */ | |
756 | pred_bb = entry_edge->src; | |
757 | loop_header = split_edge (entry_edge); | |
758 | loop_latch = split_edge (single_succ_edge (loop_header)); | |
759 | succ_bb = single_succ (loop_latch); | |
760 | make_edge (loop_header, succ_bb, 0); | |
761 | redirect_edge_succ_nodup (single_succ_edge (loop_latch), loop_header); | |
762 | ||
763 | /* Set immediate dominator information. */ | |
764 | set_immediate_dominator (CDI_DOMINATORS, loop_header, pred_bb); | |
765 | set_immediate_dominator (CDI_DOMINATORS, loop_latch, loop_header); | |
766 | set_immediate_dominator (CDI_DOMINATORS, succ_bb, loop_header); | |
767 | ||
768 | /* Initialize a loop structure and put it in a loop hierarchy. */ | |
769 | loop = alloc_loop (); | |
770 | loop->header = loop_header; | |
771 | loop->latch = loop_latch; | |
772 | add_loop (loop, outer); | |
773 | ||
774 | /* TODO: Fix frequencies and counts. */ | |
f8bf9252 SP |
775 | prob = REG_BR_PROB_BASE / 2; |
776 | ||
777 | scale_loop_frequencies (loop, REG_BR_PROB_BASE - prob, REG_BR_PROB_BASE); | |
778 | ||
779 | /* Update dominators. */ | |
780 | update_dominators_in_loop (loop); | |
781 | ||
8e74b397 SP |
782 | /* Modify edge flags. */ |
783 | exit_e = single_exit (loop); | |
784 | exit_e->flags = EDGE_LOOP_EXIT | EDGE_FALSE_VALUE; | |
785 | single_pred_edge (loop_latch)->flags = EDGE_TRUE_VALUE; | |
786 | ||
f8bf9252 SP |
787 | /* Construct IV code in loop. */ |
788 | initial_value = force_gimple_operand (initial_value, &stmts, true, iv); | |
789 | if (stmts) | |
790 | { | |
791 | gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts); | |
792 | gsi_commit_edge_inserts (); | |
793 | } | |
794 | ||
8e74b397 SP |
795 | upper_bound = force_gimple_operand (upper_bound, &stmts, true, NULL); |
796 | if (stmts) | |
797 | { | |
798 | gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts); | |
799 | gsi_commit_edge_inserts (); | |
800 | } | |
f8bf9252 | 801 | |
8e74b397 SP |
802 | gsi = gsi_last_bb (loop_header); |
803 | create_iv (initial_value, stride, iv, loop, &gsi, false, | |
804 | iv_before, iv_after); | |
f8bf9252 | 805 | |
8e74b397 SP |
806 | /* Insert loop exit condition. */ |
807 | cond_expr = gimple_build_cond | |
45e76e9f | 808 | (LT_EXPR, *iv_before, upper_bound, NULL_TREE, NULL_TREE); |
f8bf9252 SP |
809 | |
810 | exit_test = gimple_cond_lhs (cond_expr); | |
811 | exit_test = force_gimple_operand_gsi (&gsi, exit_test, true, NULL, | |
812 | false, GSI_NEW_STMT); | |
813 | gimple_cond_set_lhs (cond_expr, exit_test); | |
814 | gsi = gsi_last_bb (exit_e->src); | |
815 | gsi_insert_after (&gsi, cond_expr, GSI_NEW_STMT); | |
816 | ||
8e74b397 SP |
817 | split_block_after_labels (loop_header); |
818 | ||
f8bf9252 SP |
819 | return loop; |
820 | } | |
821 | ||
617b465c | 822 | /* Make area between HEADER_EDGE and LATCH_EDGE a loop by connecting |
d73be268 | 823 | latch to header and update loop tree and dominators |
617b465c ZD |
824 | accordingly. Everything between them plus LATCH_EDGE destination must |
825 | be dominated by HEADER_EDGE destination, and back-reachable from | |
826 | LATCH_EDGE source. HEADER_EDGE is redirected to basic block SWITCH_BB, | |
5132abc2 KH |
827 | FALSE_EDGE of SWITCH_BB to original destination of HEADER_EDGE and |
828 | TRUE_EDGE of SWITCH_BB to original destination of LATCH_EDGE. | |
03cb2019 ZD |
829 | Returns the newly created loop. Frequencies and counts in the new loop |
830 | are scaled by FALSE_SCALE and in the old one by TRUE_SCALE. */ | |
50654f6c | 831 | |
617b465c | 832 | struct loop * |
d73be268 | 833 | loopify (edge latch_edge, edge header_edge, |
5132abc2 | 834 | basic_block switch_bb, edge true_edge, edge false_edge, |
03cb2019 | 835 | bool redirect_all_edges, unsigned true_scale, unsigned false_scale) |
617b465c ZD |
836 | { |
837 | basic_block succ_bb = latch_edge->dest; | |
838 | basic_block pred_bb = header_edge->src; | |
6270df4c | 839 | struct loop *loop = alloc_loop (); |
9ba025a2 | 840 | struct loop *outer = loop_outer (succ_bb->loop_father); |
03cb2019 | 841 | int freq; |
617b465c ZD |
842 | gcov_type cnt; |
843 | edge e; | |
628f6a4e | 844 | edge_iterator ei; |
617b465c ZD |
845 | |
846 | loop->header = header_edge->dest; | |
847 | loop->latch = latch_edge->src; | |
848 | ||
849 | freq = EDGE_FREQUENCY (header_edge); | |
850 | cnt = header_edge->count; | |
617b465c ZD |
851 | |
852 | /* Redirect edges. */ | |
853 | loop_redirect_edge (latch_edge, loop->header); | |
5132abc2 | 854 | loop_redirect_edge (true_edge, succ_bb); |
50654f6c | 855 | |
92fc4a2f ZD |
856 | /* During loop versioning, one of the switch_bb edge is already properly |
857 | set. Do not redirect it again unless redirect_all_edges is true. */ | |
858 | if (redirect_all_edges) | |
859 | { | |
860 | loop_redirect_edge (header_edge, switch_bb); | |
c22cacf3 MS |
861 | loop_redirect_edge (false_edge, loop->header); |
862 | ||
92fc4a2f ZD |
863 | /* Update dominators. */ |
864 | set_immediate_dominator (CDI_DOMINATORS, switch_bb, pred_bb); | |
865 | set_immediate_dominator (CDI_DOMINATORS, loop->header, switch_bb); | |
866 | } | |
50654f6c | 867 | |
d47cc544 | 868 | set_immediate_dominator (CDI_DOMINATORS, succ_bb, switch_bb); |
617b465c ZD |
869 | |
870 | /* Compute new loop. */ | |
d73be268 | 871 | add_loop (loop, outer); |
617b465c ZD |
872 | |
873 | /* Add switch_bb to appropriate loop. */ | |
598ec7bd ZD |
874 | if (switch_bb->loop_father) |
875 | remove_bb_from_loops (switch_bb); | |
617b465c ZD |
876 | add_bb_to_loop (switch_bb, outer); |
877 | ||
878 | /* Fix frequencies. */ | |
03cb2019 ZD |
879 | if (redirect_all_edges) |
880 | { | |
881 | switch_bb->frequency = freq; | |
882 | switch_bb->count = cnt; | |
883 | FOR_EACH_EDGE (e, ei, switch_bb->succs) | |
884 | { | |
6e73e84b | 885 | e->count = RDIV (switch_bb->count * e->probability, REG_BR_PROB_BASE); |
03cb2019 ZD |
886 | } |
887 | } | |
888 | scale_loop_frequencies (loop, false_scale, REG_BR_PROB_BASE); | |
889 | scale_loop_frequencies (succ_bb->loop_father, true_scale, REG_BR_PROB_BASE); | |
f8bf9252 | 890 | update_dominators_in_loop (loop); |
617b465c ZD |
891 | |
892 | return loop; | |
893 | } | |
894 | ||
d73be268 | 895 | /* Remove the latch edge of a LOOP and update loops to indicate that |
35b07080 | 896 | the LOOP was removed. After this function, original loop latch will |
dc14f191 ZD |
897 | have no successor, which caller is expected to fix somehow. |
898 | ||
899 | If this may cause the information about irreducible regions to become | |
1a7de201 JH |
900 | invalid, IRRED_INVALIDATED is set to true. |
901 | ||
902 | LOOP_CLOSED_SSA_INVALIDATED, if non-NULL, is a bitmap where we store | |
903 | basic blocks that had non-trivial update on their loop_father.*/ | |
dc14f191 | 904 | |
b7442c2f | 905 | void |
1a7de201 JH |
906 | unloop (struct loop *loop, bool *irred_invalidated, |
907 | bitmap loop_closed_ssa_invalidated) | |
35b07080 ZD |
908 | { |
909 | basic_block *body; | |
910 | struct loop *ploop; | |
911 | unsigned i, n; | |
912 | basic_block latch = loop->latch; | |
dc14f191 ZD |
913 | bool dummy = false; |
914 | ||
915 | if (loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP) | |
916 | *irred_invalidated = true; | |
35b07080 | 917 | |
e0bb17a8 | 918 | /* This is relatively straightforward. The dominators are unchanged, as |
35b07080 ZD |
919 | loop header dominates loop latch, so the only thing we have to care of |
920 | is the placement of loops and basic blocks inside the loop tree. We | |
921 | move them all to the loop->outer, and then let fix_bb_placements do | |
922 | its work. */ | |
923 | ||
924 | body = get_loop_body (loop); | |
35b07080 ZD |
925 | n = loop->num_nodes; |
926 | for (i = 0; i < n; i++) | |
927 | if (body[i]->loop_father == loop) | |
928 | { | |
929 | remove_bb_from_loops (body[i]); | |
9ba025a2 | 930 | add_bb_to_loop (body[i], loop_outer (loop)); |
35b07080 ZD |
931 | } |
932 | free(body); | |
933 | ||
934 | while (loop->inner) | |
935 | { | |
936 | ploop = loop->inner; | |
937 | flow_loop_tree_node_remove (ploop); | |
9ba025a2 | 938 | flow_loop_tree_node_add (loop_outer (loop), ploop); |
35b07080 ZD |
939 | } |
940 | ||
941 | /* Remove the loop and free its data. */ | |
42fd6772 | 942 | delete_loop (loop); |
35b07080 | 943 | |
c5cbcccf | 944 | remove_edge (single_succ_edge (latch)); |
dc14f191 ZD |
945 | |
946 | /* We do not pass IRRED_INVALIDATED to fix_bb_placements here, as even if | |
947 | there is an irreducible region inside the cancelled loop, the flags will | |
948 | be still correct. */ | |
1a7de201 | 949 | fix_bb_placements (latch, &dummy, loop_closed_ssa_invalidated); |
35b07080 ZD |
950 | } |
951 | ||
617b465c ZD |
952 | /* Fix placement of superloops of LOOP inside loop tree, i.e. ensure that |
953 | condition stated in description of fix_loop_placement holds for them. | |
954 | It is used in case when we removed some edges coming out of LOOP, which | |
dc14f191 | 955 | may cause the right placement of LOOP inside loop tree to change. |
b8698a0f | 956 | |
dc14f191 ZD |
957 | IRRED_INVALIDATED is set to true if a change in the loop structures might |
958 | invalidate the information about irreducible regions. */ | |
959 | ||
617b465c | 960 | static void |
d73be268 | 961 | fix_loop_placements (struct loop *loop, bool *irred_invalidated) |
617b465c ZD |
962 | { |
963 | struct loop *outer; | |
964 | ||
9ba025a2 | 965 | while (loop_outer (loop)) |
617b465c | 966 | { |
9ba025a2 | 967 | outer = loop_outer (loop); |
617b465c | 968 | if (!fix_loop_placement (loop)) |
c22cacf3 | 969 | break; |
1548580c EB |
970 | |
971 | /* Changing the placement of a loop in the loop tree may alter the | |
972 | validity of condition 2) of the description of fix_bb_placement | |
973 | for its preheader, because the successor is the header and belongs | |
974 | to the loop. So call fix_bb_placements to fix up the placement | |
975 | of the preheader and (possibly) of its predecessors. */ | |
d73be268 | 976 | fix_bb_placements (loop_preheader_edge (loop)->src, |
1a7de201 | 977 | irred_invalidated, NULL); |
617b465c ZD |
978 | loop = outer; |
979 | } | |
980 | } | |
981 | ||
bf45c4c0 JH |
982 | /* Duplicate loop bounds and other information we store about |
983 | the loop into its duplicate. */ | |
984 | ||
985 | void | |
986 | copy_loop_info (struct loop *loop, struct loop *target) | |
987 | { | |
988 | gcc_checking_assert (!target->any_upper_bound && !target->any_estimate); | |
989 | target->any_upper_bound = loop->any_upper_bound; | |
990 | target->nb_iterations_upper_bound = loop->nb_iterations_upper_bound; | |
991 | target->any_estimate = loop->any_estimate; | |
992 | target->nb_iterations_estimate = loop->nb_iterations_estimate; | |
993 | target->estimate_state = loop->estimate_state; | |
994 | } | |
995 | ||
617b465c | 996 | /* Copies copy of LOOP as subloop of TARGET loop, placing newly |
d73be268 | 997 | created loop into loops structure. */ |
f67d92e9 | 998 | struct loop * |
d73be268 | 999 | duplicate_loop (struct loop *loop, struct loop *target) |
617b465c ZD |
1000 | { |
1001 | struct loop *cloop; | |
6270df4c | 1002 | cloop = alloc_loop (); |
d73be268 | 1003 | place_new_loop (cloop); |
bf45c4c0 JH |
1004 | |
1005 | copy_loop_info (loop, cloop); | |
617b465c | 1006 | |
99f8a411 | 1007 | /* Mark the new loop as copy of LOOP. */ |
561e8a90 | 1008 | set_loop_copy (loop, cloop); |
617b465c ZD |
1009 | |
1010 | /* Add it to target. */ | |
1011 | flow_loop_tree_node_add (target, cloop); | |
1012 | ||
1013 | return cloop; | |
1014 | } | |
1015 | ||
1016 | /* Copies structure of subloops of LOOP into TARGET loop, placing | |
d73be268 | 1017 | newly created loops into loop tree. */ |
48710229 | 1018 | void |
d73be268 | 1019 | duplicate_subloops (struct loop *loop, struct loop *target) |
617b465c ZD |
1020 | { |
1021 | struct loop *aloop, *cloop; | |
1022 | ||
1023 | for (aloop = loop->inner; aloop; aloop = aloop->next) | |
1024 | { | |
d73be268 ZD |
1025 | cloop = duplicate_loop (aloop, target); |
1026 | duplicate_subloops (aloop, cloop); | |
617b465c ZD |
1027 | } |
1028 | } | |
1029 | ||
1030 | /* Copies structure of subloops of N loops, stored in array COPIED_LOOPS, | |
d73be268 | 1031 | into TARGET loop, placing newly created loops into loop tree. */ |
d329e058 | 1032 | static void |
d73be268 | 1033 | copy_loops_to (struct loop **copied_loops, int n, struct loop *target) |
617b465c ZD |
1034 | { |
1035 | struct loop *aloop; | |
1036 | int i; | |
1037 | ||
1038 | for (i = 0; i < n; i++) | |
1039 | { | |
d73be268 ZD |
1040 | aloop = duplicate_loop (copied_loops[i], target); |
1041 | duplicate_subloops (copied_loops[i], aloop); | |
617b465c ZD |
1042 | } |
1043 | } | |
1044 | ||
1045 | /* Redirects edge E to basic block DEST. */ | |
1046 | static void | |
d329e058 | 1047 | loop_redirect_edge (edge e, basic_block dest) |
617b465c ZD |
1048 | { |
1049 | if (e->dest == dest) | |
1050 | return; | |
1051 | ||
9ee634e3 | 1052 | redirect_edge_and_branch_force (e, dest); |
617b465c ZD |
1053 | } |
1054 | ||
617b465c ZD |
1055 | /* Check whether LOOP's body can be duplicated. */ |
1056 | bool | |
ed7a4b4b | 1057 | can_duplicate_loop_p (const struct loop *loop) |
617b465c | 1058 | { |
8d28e87d ZD |
1059 | int ret; |
1060 | basic_block *bbs = get_loop_body (loop); | |
617b465c | 1061 | |
8d28e87d | 1062 | ret = can_copy_bbs_p (bbs, loop->num_nodes); |
617b465c | 1063 | free (bbs); |
c22cacf3 | 1064 | |
8d28e87d | 1065 | return ret; |
617b465c ZD |
1066 | } |
1067 | ||
03cb2019 ZD |
1068 | /* Sets probability and count of edge E to zero. The probability and count |
1069 | is redistributed evenly to the remaining edges coming from E->src. */ | |
1070 | ||
1071 | static void | |
1072 | set_zero_probability (edge e) | |
1073 | { | |
1074 | basic_block bb = e->src; | |
1075 | edge_iterator ei; | |
1076 | edge ae, last = NULL; | |
1077 | unsigned n = EDGE_COUNT (bb->succs); | |
1078 | gcov_type cnt = e->count, cnt1; | |
1079 | unsigned prob = e->probability, prob1; | |
1080 | ||
1081 | gcc_assert (n > 1); | |
1082 | cnt1 = cnt / (n - 1); | |
1083 | prob1 = prob / (n - 1); | |
1084 | ||
1085 | FOR_EACH_EDGE (ae, ei, bb->succs) | |
1086 | { | |
1087 | if (ae == e) | |
1088 | continue; | |
1089 | ||
1090 | ae->probability += prob1; | |
1091 | ae->count += cnt1; | |
1092 | last = ae; | |
1093 | } | |
1094 | ||
1095 | /* Move the rest to one of the edges. */ | |
1096 | last->probability += prob % (n - 1); | |
1097 | last->count += cnt % (n - 1); | |
1098 | ||
1099 | e->probability = 0; | |
1100 | e->count = 0; | |
1101 | } | |
1102 | ||
8d28e87d | 1103 | /* Duplicates body of LOOP to given edge E NDUPL times. Takes care of updating |
d73be268 | 1104 | loop structure and dominators. E's destination must be LOOP header for |
8d28e87d ZD |
1105 | this to work, i.e. it must be entry or latch edge of this loop; these are |
1106 | unique, as the loops must have preheaders for this function to work | |
1107 | correctly (in case E is latch, the function unrolls the loop, if E is entry | |
1108 | edge, it peels the loop). Store edges created by copying ORIG edge from | |
1109 | copies corresponding to set bits in WONT_EXIT bitmap (bit 0 corresponds to | |
1110 | original LOOP body, the other copies are numbered in order given by control | |
1111 | flow through them) into TO_REMOVE array. Returns false if duplication is | |
1112 | impossible. */ | |
ee8c1b05 | 1113 | |
1cb7dfc3 | 1114 | bool |
d73be268 | 1115 | duplicate_loop_to_header_edge (struct loop *loop, edge e, |
d329e058 | 1116 | unsigned int ndupl, sbitmap wont_exit, |
9771b263 | 1117 | edge orig, vec<edge> *to_remove, |
ee8c1b05 | 1118 | int flags) |
617b465c ZD |
1119 | { |
1120 | struct loop *target, *aloop; | |
1121 | struct loop **orig_loops; | |
1122 | unsigned n_orig_loops; | |
1123 | basic_block header = loop->header, latch = loop->latch; | |
1124 | basic_block *new_bbs, *bbs, *first_active; | |
1125 | basic_block new_bb, bb, first_active_latch = NULL; | |
8d28e87d ZD |
1126 | edge ae, latch_edge; |
1127 | edge spec_edges[2], new_spec_edges[2]; | |
1128 | #define SE_LATCH 0 | |
1129 | #define SE_ORIG 1 | |
617b465c ZD |
1130 | unsigned i, j, n; |
1131 | int is_latch = (latch == e->src); | |
1132 | int scale_act = 0, *scale_step = NULL, scale_main = 0; | |
03cb2019 | 1133 | int scale_after_exit = 0; |
617b465c ZD |
1134 | int p, freq_in, freq_le, freq_out_orig; |
1135 | int prob_pass_thru, prob_pass_wont_exit, prob_pass_main; | |
1136 | int add_irreducible_flag; | |
b9a66240 | 1137 | basic_block place_after; |
03cb2019 ZD |
1138 | bitmap bbs_to_scale = NULL; |
1139 | bitmap_iterator bi; | |
617b465c | 1140 | |
341c100f NS |
1141 | gcc_assert (e->dest == loop->header); |
1142 | gcc_assert (ndupl > 0); | |
617b465c ZD |
1143 | |
1144 | if (orig) | |
1145 | { | |
1146 | /* Orig must be edge out of the loop. */ | |
341c100f NS |
1147 | gcc_assert (flow_bb_inside_loop_p (loop, orig->src)); |
1148 | gcc_assert (!flow_bb_inside_loop_p (loop, orig->dest)); | |
617b465c ZD |
1149 | } |
1150 | ||
b9a66240 ZD |
1151 | n = loop->num_nodes; |
1152 | bbs = get_loop_body_in_dom_order (loop); | |
1153 | gcc_assert (bbs[0] == loop->header); | |
1154 | gcc_assert (bbs[n - 1] == loop->latch); | |
617b465c ZD |
1155 | |
1156 | /* Check whether duplication is possible. */ | |
8d28e87d | 1157 | if (!can_copy_bbs_p (bbs, loop->num_nodes)) |
617b465c | 1158 | { |
8d28e87d ZD |
1159 | free (bbs); |
1160 | return false; | |
617b465c | 1161 | } |
5ed6ace5 | 1162 | new_bbs = XNEWVEC (basic_block, loop->num_nodes); |
617b465c | 1163 | |
8d28e87d ZD |
1164 | /* In case we are doing loop peeling and the loop is in the middle of |
1165 | irreducible region, the peeled copies will be inside it too. */ | |
1166 | add_irreducible_flag = e->flags & EDGE_IRREDUCIBLE_LOOP; | |
341c100f | 1167 | gcc_assert (!is_latch || !add_irreducible_flag); |
617b465c ZD |
1168 | |
1169 | /* Find edge from latch. */ | |
1170 | latch_edge = loop_latch_edge (loop); | |
1171 | ||
1172 | if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
1173 | { | |
1174 | /* Calculate coefficients by that we have to scale frequencies | |
1175 | of duplicated loop bodies. */ | |
1176 | freq_in = header->frequency; | |
1177 | freq_le = EDGE_FREQUENCY (latch_edge); | |
1178 | if (freq_in == 0) | |
1179 | freq_in = 1; | |
1180 | if (freq_in < freq_le) | |
1181 | freq_in = freq_le; | |
1182 | freq_out_orig = orig ? EDGE_FREQUENCY (orig) : freq_in - freq_le; | |
1183 | if (freq_out_orig > freq_in - freq_le) | |
1184 | freq_out_orig = freq_in - freq_le; | |
1185 | prob_pass_thru = RDIV (REG_BR_PROB_BASE * freq_le, freq_in); | |
1186 | prob_pass_wont_exit = | |
1187 | RDIV (REG_BR_PROB_BASE * (freq_le + freq_out_orig), freq_in); | |
1188 | ||
03cb2019 ZD |
1189 | if (orig |
1190 | && REG_BR_PROB_BASE - orig->probability != 0) | |
1191 | { | |
1192 | /* The blocks that are dominated by a removed exit edge ORIG have | |
1193 | frequencies scaled by this. */ | |
1194 | scale_after_exit = RDIV (REG_BR_PROB_BASE * REG_BR_PROB_BASE, | |
1195 | REG_BR_PROB_BASE - orig->probability); | |
1196 | bbs_to_scale = BITMAP_ALLOC (NULL); | |
1197 | for (i = 0; i < n; i++) | |
1198 | { | |
1199 | if (bbs[i] != orig->src | |
1200 | && dominated_by_p (CDI_DOMINATORS, bbs[i], orig->src)) | |
1201 | bitmap_set_bit (bbs_to_scale, i); | |
1202 | } | |
1203 | } | |
1204 | ||
5ed6ace5 | 1205 | scale_step = XNEWVEC (int, ndupl); |
617b465c | 1206 | |
03cb2019 | 1207 | for (i = 1; i <= ndupl; i++) |
d7c028c0 | 1208 | scale_step[i - 1] = bitmap_bit_p (wont_exit, i) |
617b465c ZD |
1209 | ? prob_pass_wont_exit |
1210 | : prob_pass_thru; | |
1211 | ||
a4d05547 | 1212 | /* Complete peeling is special as the probability of exit in last |
c22cacf3 | 1213 | copy becomes 1. */ |
178df94f JH |
1214 | if (flags & DLTHE_FLAG_COMPLETTE_PEEL) |
1215 | { | |
1216 | int wanted_freq = EDGE_FREQUENCY (e); | |
1217 | ||
1218 | if (wanted_freq > freq_in) | |
1219 | wanted_freq = freq_in; | |
1220 | ||
1221 | gcc_assert (!is_latch); | |
a4d05547 | 1222 | /* First copy has frequency of incoming edge. Each subsequent |
178df94f JH |
1223 | frequency should be reduced by prob_pass_wont_exit. Caller |
1224 | should've managed the flags so all except for original loop | |
1225 | has won't exist set. */ | |
1226 | scale_act = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in); | |
1227 | /* Now simulate the duplication adjustments and compute header | |
1228 | frequency of the last copy. */ | |
1229 | for (i = 0; i < ndupl; i++) | |
c22cacf3 | 1230 | wanted_freq = RDIV (wanted_freq * scale_step[i], REG_BR_PROB_BASE); |
178df94f JH |
1231 | scale_main = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in); |
1232 | } | |
1233 | else if (is_latch) | |
617b465c | 1234 | { |
d7c028c0 | 1235 | prob_pass_main = bitmap_bit_p (wont_exit, 0) |
617b465c ZD |
1236 | ? prob_pass_wont_exit |
1237 | : prob_pass_thru; | |
1238 | p = prob_pass_main; | |
1239 | scale_main = REG_BR_PROB_BASE; | |
1240 | for (i = 0; i < ndupl; i++) | |
1241 | { | |
1242 | scale_main += p; | |
1243 | p = RDIV (p * scale_step[i], REG_BR_PROB_BASE); | |
1244 | } | |
1245 | scale_main = RDIV (REG_BR_PROB_BASE * REG_BR_PROB_BASE, scale_main); | |
1246 | scale_act = RDIV (scale_main * prob_pass_main, REG_BR_PROB_BASE); | |
1247 | } | |
1248 | else | |
1249 | { | |
1250 | scale_main = REG_BR_PROB_BASE; | |
1251 | for (i = 0; i < ndupl; i++) | |
1252 | scale_main = RDIV (scale_main * scale_step[i], REG_BR_PROB_BASE); | |
1253 | scale_act = REG_BR_PROB_BASE - prob_pass_thru; | |
1254 | } | |
1255 | for (i = 0; i < ndupl; i++) | |
341c100f NS |
1256 | gcc_assert (scale_step[i] >= 0 && scale_step[i] <= REG_BR_PROB_BASE); |
1257 | gcc_assert (scale_main >= 0 && scale_main <= REG_BR_PROB_BASE | |
1258 | && scale_act >= 0 && scale_act <= REG_BR_PROB_BASE); | |
617b465c ZD |
1259 | } |
1260 | ||
1261 | /* Loop the new bbs will belong to. */ | |
8d28e87d | 1262 | target = e->src->loop_father; |
617b465c ZD |
1263 | |
1264 | /* Original loops. */ | |
1265 | n_orig_loops = 0; | |
1266 | for (aloop = loop->inner; aloop; aloop = aloop->next) | |
1267 | n_orig_loops++; | |
c302207e | 1268 | orig_loops = XNEWVEC (struct loop *, n_orig_loops); |
617b465c ZD |
1269 | for (aloop = loop->inner, i = 0; aloop; aloop = aloop->next, i++) |
1270 | orig_loops[i] = aloop; | |
1271 | ||
561e8a90 | 1272 | set_loop_copy (loop, target); |
d329e058 | 1273 | |
5ed6ace5 | 1274 | first_active = XNEWVEC (basic_block, n); |
617b465c ZD |
1275 | if (is_latch) |
1276 | { | |
1277 | memcpy (first_active, bbs, n * sizeof (basic_block)); | |
1278 | first_active_latch = latch; | |
1279 | } | |
1280 | ||
8d28e87d ZD |
1281 | spec_edges[SE_ORIG] = orig; |
1282 | spec_edges[SE_LATCH] = latch_edge; | |
d329e058 | 1283 | |
b9a66240 | 1284 | place_after = e->src; |
617b465c ZD |
1285 | for (j = 0; j < ndupl; j++) |
1286 | { | |
1287 | /* Copy loops. */ | |
d73be268 | 1288 | copy_loops_to (orig_loops, n_orig_loops, target); |
617b465c ZD |
1289 | |
1290 | /* Copy bbs. */ | |
b9a66240 ZD |
1291 | copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop, |
1292 | place_after); | |
1293 | place_after = new_spec_edges[SE_LATCH]->src; | |
8d28e87d | 1294 | |
7f7b1718 JH |
1295 | if (flags & DLTHE_RECORD_COPY_NUMBER) |
1296 | for (i = 0; i < n; i++) | |
1297 | { | |
1298 | gcc_assert (!new_bbs[i]->aux); | |
1299 | new_bbs[i]->aux = (void *)(size_t)(j + 1); | |
1300 | } | |
113d659a | 1301 | |
84d45ad1 ZD |
1302 | /* Note whether the blocks and edges belong to an irreducible loop. */ |
1303 | if (add_irreducible_flag) | |
1304 | { | |
1305 | for (i = 0; i < n; i++) | |
6580ee77 | 1306 | new_bbs[i]->flags |= BB_DUPLICATED; |
84d45ad1 ZD |
1307 | for (i = 0; i < n; i++) |
1308 | { | |
628f6a4e | 1309 | edge_iterator ei; |
84d45ad1 ZD |
1310 | new_bb = new_bbs[i]; |
1311 | if (new_bb->loop_father == target) | |
1312 | new_bb->flags |= BB_IRREDUCIBLE_LOOP; | |
1313 | ||
628f6a4e | 1314 | FOR_EACH_EDGE (ae, ei, new_bb->succs) |
6580ee77 | 1315 | if ((ae->dest->flags & BB_DUPLICATED) |
84d45ad1 ZD |
1316 | && (ae->src->loop_father == target |
1317 | || ae->dest->loop_father == target)) | |
1318 | ae->flags |= EDGE_IRREDUCIBLE_LOOP; | |
1319 | } | |
1320 | for (i = 0; i < n; i++) | |
6580ee77 | 1321 | new_bbs[i]->flags &= ~BB_DUPLICATED; |
84d45ad1 ZD |
1322 | } |
1323 | ||
8d28e87d | 1324 | /* Redirect the special edges. */ |
617b465c | 1325 | if (is_latch) |
8d28e87d ZD |
1326 | { |
1327 | redirect_edge_and_branch_force (latch_edge, new_bbs[0]); | |
1328 | redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
1329 | loop->header); | |
d47cc544 | 1330 | set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], latch); |
b9a66240 | 1331 | latch = loop->latch = new_bbs[n - 1]; |
8d28e87d ZD |
1332 | e = latch_edge = new_spec_edges[SE_LATCH]; |
1333 | } | |
1334 | else | |
1335 | { | |
1336 | redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
1337 | loop->header); | |
1338 | redirect_edge_and_branch_force (e, new_bbs[0]); | |
d47cc544 | 1339 | set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], e->src); |
8d28e87d ZD |
1340 | e = new_spec_edges[SE_LATCH]; |
1341 | } | |
617b465c | 1342 | |
8d28e87d | 1343 | /* Record exit edge in this copy. */ |
d7c028c0 | 1344 | if (orig && bitmap_bit_p (wont_exit, j + 1)) |
ee8c1b05 ZD |
1345 | { |
1346 | if (to_remove) | |
9771b263 | 1347 | to_remove->safe_push (new_spec_edges[SE_ORIG]); |
03cb2019 ZD |
1348 | set_zero_probability (new_spec_edges[SE_ORIG]); |
1349 | ||
1350 | /* Scale the frequencies of the blocks dominated by the exit. */ | |
1351 | if (bbs_to_scale) | |
1352 | { | |
1353 | EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
1354 | { | |
1355 | scale_bbs_frequencies_int (new_bbs + i, 1, scale_after_exit, | |
1356 | REG_BR_PROB_BASE); | |
1357 | } | |
1358 | } | |
ee8c1b05 | 1359 | } |
d329e058 | 1360 | |
8d28e87d ZD |
1361 | /* Record the first copy in the control flow order if it is not |
1362 | the original loop (i.e. in case of peeling). */ | |
617b465c ZD |
1363 | if (!first_active_latch) |
1364 | { | |
1365 | memcpy (first_active, new_bbs, n * sizeof (basic_block)); | |
b9a66240 | 1366 | first_active_latch = new_bbs[n - 1]; |
617b465c | 1367 | } |
d329e058 | 1368 | |
8d28e87d ZD |
1369 | /* Set counts and frequencies. */ |
1370 | if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
617b465c | 1371 | { |
33156717 | 1372 | scale_bbs_frequencies_int (new_bbs, n, scale_act, REG_BR_PROB_BASE); |
8d28e87d | 1373 | scale_act = RDIV (scale_act * scale_step[j], REG_BR_PROB_BASE); |
617b465c ZD |
1374 | } |
1375 | } | |
8d28e87d ZD |
1376 | free (new_bbs); |
1377 | free (orig_loops); | |
c22cacf3 | 1378 | |
ee8c1b05 | 1379 | /* Record the exit edge in the original loop body, and update the frequencies. */ |
d7c028c0 | 1380 | if (orig && bitmap_bit_p (wont_exit, 0)) |
ee8c1b05 ZD |
1381 | { |
1382 | if (to_remove) | |
9771b263 | 1383 | to_remove->safe_push (orig); |
03cb2019 ZD |
1384 | set_zero_probability (orig); |
1385 | ||
1386 | /* Scale the frequencies of the blocks dominated by the exit. */ | |
1387 | if (bbs_to_scale) | |
1388 | { | |
1389 | EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
1390 | { | |
1391 | scale_bbs_frequencies_int (bbs + i, 1, scale_after_exit, | |
1392 | REG_BR_PROB_BASE); | |
1393 | } | |
1394 | } | |
ee8c1b05 ZD |
1395 | } |
1396 | ||
8d28e87d ZD |
1397 | /* Update the original loop. */ |
1398 | if (!is_latch) | |
d47cc544 | 1399 | set_immediate_dominator (CDI_DOMINATORS, e->dest, e->src); |
617b465c ZD |
1400 | if (flags & DLTHE_FLAG_UPDATE_FREQ) |
1401 | { | |
33156717 | 1402 | scale_bbs_frequencies_int (bbs, n, scale_main, REG_BR_PROB_BASE); |
617b465c ZD |
1403 | free (scale_step); |
1404 | } | |
617b465c | 1405 | |
8d28e87d | 1406 | /* Update dominators of outer blocks if affected. */ |
617b465c ZD |
1407 | for (i = 0; i < n; i++) |
1408 | { | |
66f97d31 | 1409 | basic_block dominated, dom_bb; |
9771b263 | 1410 | vec<basic_block> dom_bbs; |
66f97d31 | 1411 | unsigned j; |
617b465c ZD |
1412 | |
1413 | bb = bbs[i]; | |
6580ee77 | 1414 | bb->aux = 0; |
113d659a | 1415 | |
66f97d31 | 1416 | dom_bbs = get_dominated_by (CDI_DOMINATORS, bb); |
9771b263 | 1417 | FOR_EACH_VEC_ELT (dom_bbs, j, dominated) |
617b465c | 1418 | { |
617b465c ZD |
1419 | if (flow_bb_inside_loop_p (loop, dominated)) |
1420 | continue; | |
1421 | dom_bb = nearest_common_dominator ( | |
d47cc544 | 1422 | CDI_DOMINATORS, first_active[i], first_active_latch); |
c22cacf3 | 1423 | set_immediate_dominator (CDI_DOMINATORS, dominated, dom_bb); |
617b465c | 1424 | } |
9771b263 | 1425 | dom_bbs.release (); |
617b465c ZD |
1426 | } |
1427 | free (first_active); | |
1428 | ||
1429 | free (bbs); | |
03cb2019 | 1430 | BITMAP_FREE (bbs_to_scale); |
617b465c ZD |
1431 | |
1432 | return true; | |
1433 | } | |
1434 | ||
f470c378 ZD |
1435 | /* A callback for make_forwarder block, to redirect all edges except for |
1436 | MFB_KJ_EDGE to the entry part. E is the edge for that we should decide | |
1437 | whether to redirect it. */ | |
1438 | ||
b02b9b53 ZD |
1439 | edge mfb_kj_edge; |
1440 | bool | |
f470c378 ZD |
1441 | mfb_keep_just (edge e) |
1442 | { | |
1443 | return e != mfb_kj_edge; | |
1444 | } | |
1445 | ||
e855c69d AB |
1446 | /* True when a candidate preheader BLOCK has predecessors from LOOP. */ |
1447 | ||
1448 | static bool | |
1449 | has_preds_from_loop (basic_block block, struct loop *loop) | |
1450 | { | |
1451 | edge e; | |
1452 | edge_iterator ei; | |
b8698a0f | 1453 | |
e855c69d AB |
1454 | FOR_EACH_EDGE (e, ei, block->preds) |
1455 | if (e->src->loop_father == loop) | |
1456 | return true; | |
1457 | return false; | |
1458 | } | |
1459 | ||
3d436d2a ZD |
1460 | /* Creates a pre-header for a LOOP. Returns newly created block. Unless |
1461 | CP_SIMPLE_PREHEADERS is set in FLAGS, we only force LOOP to have single | |
1462 | entry; otherwise we also force preheader block to have only one successor. | |
e855c69d | 1463 | When CP_FALLTHRU_PREHEADERS is set in FLAGS, we force the preheader block |
b8698a0f | 1464 | to be a fallthru predecessor to the loop header and to have only |
e855c69d | 1465 | predecessors from outside of the loop. |
f470c378 ZD |
1466 | The function also updates dominators. */ |
1467 | ||
b02b9b53 | 1468 | basic_block |
d47cc544 | 1469 | create_preheader (struct loop *loop, int flags) |
3d436d2a ZD |
1470 | { |
1471 | edge e, fallthru; | |
1472 | basic_block dummy; | |
3d436d2a | 1473 | int nentry = 0; |
f470c378 | 1474 | bool irred = false; |
c15bc84b | 1475 | bool latch_edge_was_fallthru; |
c7b852c8 | 1476 | edge one_succ_pred = NULL, single_entry = NULL; |
628f6a4e | 1477 | edge_iterator ei; |
3d436d2a | 1478 | |
628f6a4e | 1479 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
3d436d2a ZD |
1480 | { |
1481 | if (e->src == loop->latch) | |
1482 | continue; | |
f470c378 | 1483 | irred |= (e->flags & EDGE_IRREDUCIBLE_LOOP) != 0; |
3d436d2a | 1484 | nentry++; |
c7b852c8 | 1485 | single_entry = e; |
c5cbcccf | 1486 | if (single_succ_p (e->src)) |
c15bc84b | 1487 | one_succ_pred = e; |
3d436d2a | 1488 | } |
341c100f | 1489 | gcc_assert (nentry); |
3d436d2a ZD |
1490 | if (nentry == 1) |
1491 | { | |
e855c69d | 1492 | bool need_forwarder_block = false; |
b8698a0f | 1493 | |
e855c69d | 1494 | /* We do not allow entry block to be the loop preheader, since we |
89f8f30f | 1495 | cannot emit code there. */ |
e855c69d AB |
1496 | if (single_entry->src == ENTRY_BLOCK_PTR) |
1497 | need_forwarder_block = true; | |
1498 | else | |
1499 | { | |
1500 | /* If we want simple preheaders, also force the preheader to have | |
1501 | just a single successor. */ | |
1502 | if ((flags & CP_SIMPLE_PREHEADERS) | |
1503 | && !single_succ_p (single_entry->src)) | |
1504 | need_forwarder_block = true; | |
1505 | /* If we want fallthru preheaders, also create forwarder block when | |
1506 | preheader ends with a jump or has predecessors from loop. */ | |
1507 | else if ((flags & CP_FALLTHRU_PREHEADERS) | |
1508 | && (JUMP_P (BB_END (single_entry->src)) | |
1509 | || has_preds_from_loop (single_entry->src, loop))) | |
1510 | need_forwarder_block = true; | |
1511 | } | |
1512 | if (! need_forwarder_block) | |
3d436d2a ZD |
1513 | return NULL; |
1514 | } | |
1515 | ||
f470c378 | 1516 | mfb_kj_edge = loop_latch_edge (loop); |
c15bc84b | 1517 | latch_edge_was_fallthru = (mfb_kj_edge->flags & EDGE_FALLTHRU) != 0; |
598ec7bd | 1518 | fallthru = make_forwarder_block (loop->header, mfb_keep_just, NULL); |
3d436d2a ZD |
1519 | dummy = fallthru->src; |
1520 | loop->header = fallthru->dest; | |
1521 | ||
c15bc84b EB |
1522 | /* Try to be clever in placing the newly created preheader. The idea is to |
1523 | avoid breaking any "fallthruness" relationship between blocks. | |
1524 | ||
1525 | The preheader was created just before the header and all incoming edges | |
1526 | to the header were redirected to the preheader, except the latch edge. | |
1527 | So the only problematic case is when this latch edge was a fallthru | |
1528 | edge: it is not anymore after the preheader creation so we have broken | |
1529 | the fallthruness. We're therefore going to look for a better place. */ | |
1530 | if (latch_edge_was_fallthru) | |
1531 | { | |
1532 | if (one_succ_pred) | |
1533 | e = one_succ_pred; | |
1534 | else | |
1535 | e = EDGE_PRED (dummy, 0); | |
1536 | ||
1537 | move_block_after (dummy, e->src); | |
1538 | } | |
f470c378 | 1539 | |
f470c378 | 1540 | if (irred) |
3d436d2a | 1541 | { |
f470c378 | 1542 | dummy->flags |= BB_IRREDUCIBLE_LOOP; |
c5cbcccf | 1543 | single_succ_edge (dummy)->flags |= EDGE_IRREDUCIBLE_LOOP; |
3d436d2a ZD |
1544 | } |
1545 | ||
c263766c RH |
1546 | if (dump_file) |
1547 | fprintf (dump_file, "Created preheader block for loop %i\n", | |
3d436d2a | 1548 | loop->num); |
b8698a0f | 1549 | |
e855c69d AB |
1550 | if (flags & CP_FALLTHRU_PREHEADERS) |
1551 | gcc_assert ((single_succ_edge (dummy)->flags & EDGE_FALLTHRU) | |
1552 | && !JUMP_P (BB_END (dummy))); | |
3d436d2a ZD |
1553 | |
1554 | return dummy; | |
1555 | } | |
1556 | ||
d73be268 ZD |
1557 | /* Create preheaders for each loop; for meaning of FLAGS see create_preheader. */ |
1558 | ||
3d436d2a | 1559 | void |
d73be268 | 1560 | create_preheaders (int flags) |
3d436d2a | 1561 | { |
42fd6772 ZD |
1562 | loop_iterator li; |
1563 | struct loop *loop; | |
1564 | ||
c7b852c8 ZD |
1565 | if (!current_loops) |
1566 | return; | |
1567 | ||
42fd6772 ZD |
1568 | FOR_EACH_LOOP (li, loop, 0) |
1569 | create_preheader (loop, flags); | |
f87000d0 | 1570 | loops_state_set (LOOPS_HAVE_PREHEADERS); |
3d436d2a ZD |
1571 | } |
1572 | ||
d73be268 ZD |
1573 | /* Forces all loop latches to have only single successor. */ |
1574 | ||
3d436d2a | 1575 | void |
d73be268 | 1576 | force_single_succ_latches (void) |
3d436d2a | 1577 | { |
42fd6772 | 1578 | loop_iterator li; |
3d436d2a ZD |
1579 | struct loop *loop; |
1580 | edge e; | |
1581 | ||
42fd6772 | 1582 | FOR_EACH_LOOP (li, loop, 0) |
3d436d2a | 1583 | { |
c5cbcccf | 1584 | if (loop->latch != loop->header && single_succ_p (loop->latch)) |
3d436d2a | 1585 | continue; |
d329e058 | 1586 | |
9ff3d2de | 1587 | e = find_edge (loop->latch, loop->header); |
9dcbb380 | 1588 | gcc_checking_assert (e != NULL); |
bc810602 | 1589 | |
598ec7bd | 1590 | split_edge (e); |
3d436d2a | 1591 | } |
f87000d0 | 1592 | loops_state_set (LOOPS_HAVE_SIMPLE_LATCHES); |
3d436d2a ZD |
1593 | } |
1594 | ||
1cb7dfc3 MH |
1595 | /* This function is called from loop_version. It splits the entry edge |
1596 | of the loop we want to version, adds the versioning condition, and | |
1597 | adjust the edges to the two versions of the loop appropriately. | |
1598 | e is an incoming edge. Returns the basic block containing the | |
1599 | condition. | |
1600 | ||
1601 | --- edge e ---- > [second_head] | |
1602 | ||
1603 | Split it and insert new conditional expression and adjust edges. | |
1604 | ||
1605 | --- edge e ---> [cond expr] ---> [first_head] | |
c22cacf3 MS |
1606 | | |
1607 | +---------> [second_head] | |
03cb2019 ZD |
1608 | |
1609 | THEN_PROB is the probability of then branch of the condition. */ | |
1cb7dfc3 MH |
1610 | |
1611 | static basic_block | |
03cb2019 ZD |
1612 | lv_adjust_loop_entry_edge (basic_block first_head, basic_block second_head, |
1613 | edge e, void *cond_expr, unsigned then_prob) | |
1cb7dfc3 MH |
1614 | { |
1615 | basic_block new_head = NULL; | |
1616 | edge e1; | |
1617 | ||
1618 | gcc_assert (e->dest == second_head); | |
1619 | ||
1620 | /* Split edge 'e'. This will create a new basic block, where we can | |
1621 | insert conditional expr. */ | |
1622 | new_head = split_edge (e); | |
1623 | ||
1cb7dfc3 MH |
1624 | lv_add_condition_to_bb (first_head, second_head, new_head, |
1625 | cond_expr); | |
1626 | ||
766613a4 | 1627 | /* Don't set EDGE_TRUE_VALUE in RTL mode, as it's invalid there. */ |
03cb2019 | 1628 | e = single_succ_edge (new_head); |
52bca999 SB |
1629 | e1 = make_edge (new_head, first_head, |
1630 | current_ir_type () == IR_GIMPLE ? EDGE_TRUE_VALUE : 0); | |
03cb2019 ZD |
1631 | e1->probability = then_prob; |
1632 | e->probability = REG_BR_PROB_BASE - then_prob; | |
1633 | e1->count = RDIV (e->count * e1->probability, REG_BR_PROB_BASE); | |
1634 | e->count = RDIV (e->count * e->probability, REG_BR_PROB_BASE); | |
1635 | ||
1cb7dfc3 MH |
1636 | set_immediate_dominator (CDI_DOMINATORS, first_head, new_head); |
1637 | set_immediate_dominator (CDI_DOMINATORS, second_head, new_head); | |
1638 | ||
1639 | /* Adjust loop header phi nodes. */ | |
1640 | lv_adjust_loop_header_phi (first_head, second_head, new_head, e1); | |
1641 | ||
1642 | return new_head; | |
1643 | } | |
1644 | ||
1645 | /* Main entry point for Loop Versioning transformation. | |
c22cacf3 | 1646 | |
b9a66240 ZD |
1647 | This transformation given a condition and a loop, creates |
1648 | -if (condition) { loop_copy1 } else { loop_copy2 }, | |
1649 | where loop_copy1 is the loop transformed in one way, and loop_copy2 | |
1650 | is the loop transformed in another way (or unchanged). 'condition' | |
1651 | may be a run time test for things that were not resolved by static | |
1652 | analysis (overlapping ranges (anti-aliasing), alignment, etc.). | |
1653 | ||
03cb2019 ZD |
1654 | THEN_PROB is the probability of the then edge of the if. THEN_SCALE |
1655 | is the ratio by that the frequencies in the original loop should | |
1656 | be scaled. ELSE_SCALE is the ratio by that the frequencies in the | |
1657 | new loop should be scaled. | |
b8698a0f | 1658 | |
b9a66240 ZD |
1659 | If PLACE_AFTER is true, we place the new loop after LOOP in the |
1660 | instruction stream, otherwise it is placed before LOOP. */ | |
1cb7dfc3 MH |
1661 | |
1662 | struct loop * | |
d73be268 | 1663 | loop_version (struct loop *loop, |
b9a66240 | 1664 | void *cond_expr, basic_block *condition_bb, |
03cb2019 | 1665 | unsigned then_prob, unsigned then_scale, unsigned else_scale, |
b9a66240 | 1666 | bool place_after) |
1cb7dfc3 MH |
1667 | { |
1668 | basic_block first_head, second_head; | |
6270df4c | 1669 | edge entry, latch_edge, true_edge, false_edge; |
1cb7dfc3 MH |
1670 | int irred_flag; |
1671 | struct loop *nloop; | |
b9a66240 | 1672 | basic_block cond_bb; |
1cb7dfc3 | 1673 | |
1cb7dfc3 MH |
1674 | /* Record entry and latch edges for the loop */ |
1675 | entry = loop_preheader_edge (loop); | |
1676 | irred_flag = entry->flags & EDGE_IRREDUCIBLE_LOOP; | |
1677 | entry->flags &= ~EDGE_IRREDUCIBLE_LOOP; | |
c22cacf3 | 1678 | |
1cb7dfc3 MH |
1679 | /* Note down head of loop as first_head. */ |
1680 | first_head = entry->dest; | |
1681 | ||
1682 | /* Duplicate loop. */ | |
d73be268 | 1683 | if (!cfg_hook_duplicate_loop_to_header_edge (loop, entry, 1, |
ee8c1b05 | 1684 | NULL, NULL, NULL, 0)) |
71056fef JJ |
1685 | { |
1686 | entry->flags |= irred_flag; | |
1687 | return NULL; | |
1688 | } | |
1cb7dfc3 MH |
1689 | |
1690 | /* After duplication entry edge now points to new loop head block. | |
1691 | Note down new head as second_head. */ | |
1692 | second_head = entry->dest; | |
1693 | ||
1694 | /* Split loop entry edge and insert new block with cond expr. */ | |
b9a66240 | 1695 | cond_bb = lv_adjust_loop_entry_edge (first_head, second_head, |
03cb2019 | 1696 | entry, cond_expr, then_prob); |
b9a66240 ZD |
1697 | if (condition_bb) |
1698 | *condition_bb = cond_bb; | |
1699 | ||
1700 | if (!cond_bb) | |
1cb7dfc3 MH |
1701 | { |
1702 | entry->flags |= irred_flag; | |
1703 | return NULL; | |
1704 | } | |
1705 | ||
6580ee77 | 1706 | latch_edge = single_succ_edge (get_bb_copy (loop->latch)); |
c22cacf3 | 1707 | |
b9a66240 | 1708 | extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); |
d73be268 | 1709 | nloop = loopify (latch_edge, |
6580ee77 | 1710 | single_pred_edge (get_bb_copy (loop->header)), |
b9a66240 | 1711 | cond_bb, true_edge, false_edge, |
03cb2019 ZD |
1712 | false /* Do not redirect all edges. */, |
1713 | then_scale, else_scale); | |
1cb7dfc3 | 1714 | |
bf45c4c0 JH |
1715 | copy_loop_info (loop, nloop); |
1716 | ||
c22cacf3 | 1717 | /* loopify redirected latch_edge. Update its PENDING_STMTS. */ |
1cb7dfc3 MH |
1718 | lv_flush_pending_stmts (latch_edge); |
1719 | ||
c22cacf3 | 1720 | /* loopify redirected condition_bb's succ edge. Update its PENDING_STMTS. */ |
b9a66240 | 1721 | extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); |
1cb7dfc3 MH |
1722 | lv_flush_pending_stmts (false_edge); |
1723 | /* Adjust irreducible flag. */ | |
1724 | if (irred_flag) | |
1725 | { | |
b9a66240 | 1726 | cond_bb->flags |= BB_IRREDUCIBLE_LOOP; |
1cb7dfc3 MH |
1727 | loop_preheader_edge (loop)->flags |= EDGE_IRREDUCIBLE_LOOP; |
1728 | loop_preheader_edge (nloop)->flags |= EDGE_IRREDUCIBLE_LOOP; | |
b9a66240 ZD |
1729 | single_pred_edge (cond_bb)->flags |= EDGE_IRREDUCIBLE_LOOP; |
1730 | } | |
1731 | ||
1732 | if (place_after) | |
1733 | { | |
1734 | basic_block *bbs = get_loop_body_in_dom_order (nloop), after; | |
1735 | unsigned i; | |
1736 | ||
1737 | after = loop->latch; | |
1738 | ||
1739 | for (i = 0; i < nloop->num_nodes; i++) | |
1740 | { | |
1741 | move_block_after (bbs[i], after); | |
1742 | after = bbs[i]; | |
1743 | } | |
1744 | free (bbs); | |
1cb7dfc3 MH |
1745 | } |
1746 | ||
fa10beec RW |
1747 | /* At this point condition_bb is loop preheader with two successors, |
1748 | first_head and second_head. Make sure that loop preheader has only | |
1cb7dfc3 | 1749 | one successor. */ |
598ec7bd ZD |
1750 | split_edge (loop_preheader_edge (loop)); |
1751 | split_edge (loop_preheader_edge (nloop)); | |
1cb7dfc3 MH |
1752 | |
1753 | return nloop; | |
1754 | } | |
1755 | ||
d73be268 | 1756 | /* The structure of loops might have changed. Some loops might get removed |
2b271002 ZD |
1757 | (and their headers and latches were set to NULL), loop exists might get |
1758 | removed (thus the loop nesting may be wrong), and some blocks and edges | |
1759 | were changed (so the information about bb --> loop mapping does not have | |
1760 | to be correct). But still for the remaining loops the header dominates | |
fa10beec | 1761 | the latch, and loops did not get new subloops (new loops might possibly |
2b271002 | 1762 | get created, but we are not interested in them). Fix up the mess. |
c22cacf3 | 1763 | |
2b271002 ZD |
1764 | If CHANGED_BBS is not NULL, basic blocks whose loop has changed are |
1765 | marked in it. */ | |
1766 | ||
1767 | void | |
d73be268 | 1768 | fix_loop_structure (bitmap changed_bbs) |
2b271002 ZD |
1769 | { |
1770 | basic_block bb; | |
1771 | struct loop *loop, *ploop; | |
42fd6772 | 1772 | loop_iterator li; |
c7b852c8 ZD |
1773 | bool record_exits = false; |
1774 | struct loop **superloop = XNEWVEC (struct loop *, number_of_loops ()); | |
2b271002 | 1775 | |
cc360b36 SB |
1776 | /* We need exact and fast dominance info to be available. */ |
1777 | gcc_assert (dom_info_state (CDI_DOMINATORS) == DOM_OK); | |
1778 | ||
c7b852c8 ZD |
1779 | /* Remove the old bb -> loop mapping. Remember the depth of the blocks in |
1780 | the loop hierarchy, so that we can recognize blocks whose loop nesting | |
1781 | relationship has changed. */ | |
2b271002 ZD |
1782 | FOR_EACH_BB (bb) |
1783 | { | |
c7b852c8 | 1784 | if (changed_bbs) |
9ba025a2 | 1785 | bb->aux = (void *) (size_t) loop_depth (bb->loop_father); |
d73be268 | 1786 | bb->loop_father = current_loops->tree_root; |
2b271002 ZD |
1787 | } |
1788 | ||
f87000d0 | 1789 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
c7b852c8 ZD |
1790 | { |
1791 | release_recorded_exits (); | |
1792 | record_exits = true; | |
1793 | } | |
1794 | ||
867fdd05 RB |
1795 | /* First re-compute loop latches. */ |
1796 | FOR_EACH_LOOP (li, loop, 0) | |
1797 | { | |
1798 | edge_iterator ei; | |
1799 | edge e, first_latch = NULL, latch = NULL; | |
1800 | ||
1801 | if (!loop->header) | |
1802 | continue; | |
1803 | ||
1804 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
1805 | if (dominated_by_p (CDI_DOMINATORS, e->src, loop->header)) | |
1806 | { | |
1807 | if (!first_latch) | |
1808 | first_latch = latch = e; | |
1809 | else | |
1810 | { | |
1811 | latch = NULL; | |
1812 | break; | |
1813 | } | |
1814 | } | |
1815 | /* If there was no latch, schedule the loop for removal. */ | |
1816 | if (!first_latch) | |
1817 | loop->header = NULL; | |
1818 | /* If there was a single latch and it belongs to the loop of the | |
1819 | header, record it. */ | |
1820 | else if (latch | |
1821 | && latch->src->loop_father == loop) | |
1822 | loop->latch = latch->src; | |
1823 | /* Otherwise there are multiple latches which are eventually | |
1824 | disambiguated below. */ | |
1825 | else | |
1826 | loop->latch = NULL; | |
1827 | } | |
1828 | ||
c7b852c8 ZD |
1829 | /* Remove the dead loops from structures. We start from the innermost |
1830 | loops, so that when we remove the loops, we know that the loops inside | |
1831 | are preserved, and do not waste time relinking loops that will be | |
1832 | removed later. */ | |
1833 | FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST) | |
2b271002 | 1834 | { |
2b271002 ZD |
1835 | if (loop->header) |
1836 | continue; | |
1837 | ||
1838 | while (loop->inner) | |
1839 | { | |
1840 | ploop = loop->inner; | |
1841 | flow_loop_tree_node_remove (ploop); | |
9ba025a2 | 1842 | flow_loop_tree_node_add (loop_outer (loop), ploop); |
2b271002 ZD |
1843 | } |
1844 | ||
1845 | /* Remove the loop and free its data. */ | |
42fd6772 | 1846 | delete_loop (loop); |
2b271002 ZD |
1847 | } |
1848 | ||
c7b852c8 ZD |
1849 | /* Rescan the bodies of loops, starting from the outermost ones. We assume |
1850 | that no optimization interchanges the order of the loops, i.e., it cannot | |
1851 | happen that L1 was superloop of L2 before and it is subloop of L2 now | |
1852 | (without explicitly updating loop information). At the same time, we also | |
1853 | determine the new loop structure. */ | |
1854 | current_loops->tree_root->num_nodes = n_basic_blocks; | |
42fd6772 | 1855 | FOR_EACH_LOOP (li, loop, 0) |
2b271002 | 1856 | { |
c7b852c8 | 1857 | superloop[loop->num] = loop->header->loop_father; |
2b271002 ZD |
1858 | loop->num_nodes = flow_loop_nodes_find (loop->header, loop); |
1859 | } | |
1860 | ||
1861 | /* Now fix the loop nesting. */ | |
42fd6772 | 1862 | FOR_EACH_LOOP (li, loop, 0) |
2b271002 | 1863 | { |
c7b852c8 | 1864 | ploop = superloop[loop->num]; |
9ba025a2 | 1865 | if (ploop != loop_outer (loop)) |
2b271002 ZD |
1866 | { |
1867 | flow_loop_tree_node_remove (loop); | |
c7b852c8 | 1868 | flow_loop_tree_node_add (ploop, loop); |
2b271002 ZD |
1869 | } |
1870 | } | |
c7b852c8 | 1871 | free (superloop); |
2b271002 ZD |
1872 | |
1873 | /* Mark the blocks whose loop has changed. */ | |
c7b852c8 | 1874 | if (changed_bbs) |
2b271002 | 1875 | { |
c7b852c8 ZD |
1876 | FOR_EACH_BB (bb) |
1877 | { | |
9ba025a2 | 1878 | if ((void *) (size_t) loop_depth (bb->loop_father) != bb->aux) |
c7b852c8 | 1879 | bitmap_set_bit (changed_bbs, bb->index); |
2b271002 | 1880 | |
c7b852c8 ZD |
1881 | bb->aux = NULL; |
1882 | } | |
2b271002 ZD |
1883 | } |
1884 | ||
9dcbb380 RG |
1885 | if (!loops_state_satisfies_p (LOOPS_MAY_HAVE_MULTIPLE_LATCHES)) |
1886 | disambiguate_loops_with_multiple_latches (); | |
1887 | ||
f87000d0 | 1888 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)) |
867fdd05 RB |
1889 | { |
1890 | int cp_flags = CP_SIMPLE_PREHEADERS; | |
1891 | ||
1892 | if (loops_state_satisfies_p (LOOPS_HAVE_FALLTHRU_PREHEADERS)) | |
1893 | cp_flags |= CP_FALLTHRU_PREHEADERS; | |
1894 | ||
1895 | create_preheaders (cp_flags); | |
1896 | } | |
c7b852c8 | 1897 | |
f87000d0 | 1898 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
af0b10e5 ZD |
1899 | force_single_succ_latches (); |
1900 | ||
f87000d0 | 1901 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
d73be268 | 1902 | mark_irreducible_loops (); |
6270df4c | 1903 | |
c7b852c8 ZD |
1904 | if (record_exits) |
1905 | record_loop_exits (); | |
1906 | ||
7d776ee2 RG |
1907 | loops_state_clear (LOOPS_NEED_FIXUP); |
1908 | ||
c7b852c8 ZD |
1909 | #ifdef ENABLE_CHECKING |
1910 | verify_loop_structure (); | |
1911 | #endif | |
2b271002 | 1912 | } |