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3d436d2a | 1 | /* Loop manipulation code for GNU compiler. |
fa10beec RW |
2 | Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008 Free Software |
3 | Foundation, Inc. | |
3d436d2a ZD |
4 | |
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
3d436d2a ZD |
10 | version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
3d436d2a ZD |
20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
24 | #include "tm.h" | |
25 | #include "rtl.h" | |
26 | #include "hard-reg-set.h" | |
7932a3db | 27 | #include "obstack.h" |
3d436d2a ZD |
28 | #include "basic-block.h" |
29 | #include "cfgloop.h" | |
30 | #include "cfglayout.h" | |
1cb7dfc3 | 31 | #include "cfghooks.h" |
3d436d2a | 32 | #include "output.h" |
f8bf9252 | 33 | #include "tree-flow.h" |
3d436d2a | 34 | |
d73be268 ZD |
35 | static void duplicate_subloops (struct loop *, struct loop *); |
36 | static void copy_loops_to (struct loop **, int, | |
d329e058 AJ |
37 | struct loop *); |
38 | static void loop_redirect_edge (edge, basic_block); | |
d47cc544 | 39 | static void remove_bbs (basic_block *, int); |
ed7a4b4b | 40 | static bool rpe_enum_p (const_basic_block, const void *); |
d47cc544 | 41 | static int find_path (edge, basic_block **); |
d73be268 ZD |
42 | static void fix_loop_placements (struct loop *, bool *); |
43 | static bool fix_bb_placement (basic_block); | |
44 | static void fix_bb_placements (basic_block, bool *); | |
d73be268 | 45 | static void unloop (struct loop *, bool *); |
3d436d2a | 46 | |
bade3a00 JH |
47 | #define RDIV(X,Y) (((X) + (Y) / 2) / (Y)) |
48 | ||
d47cc544 | 49 | /* Checks whether basic block BB is dominated by DATA. */ |
617b465c | 50 | static bool |
ed7a4b4b | 51 | rpe_enum_p (const_basic_block bb, const void *data) |
617b465c | 52 | { |
ed7a4b4b | 53 | return dominated_by_p (CDI_DOMINATORS, bb, (const_basic_block) data); |
617b465c ZD |
54 | } |
55 | ||
598ec7bd ZD |
56 | /* Remove basic blocks BBS. NBBS is the number of the basic blocks. */ |
57 | ||
617b465c | 58 | static void |
d47cc544 | 59 | remove_bbs (basic_block *bbs, int nbbs) |
617b465c ZD |
60 | { |
61 | int i; | |
62 | ||
63 | for (i = 0; i < nbbs; i++) | |
598ec7bd | 64 | delete_basic_block (bbs[i]); |
617b465c ZD |
65 | } |
66 | ||
67 | /* Find path -- i.e. the basic blocks dominated by edge E and put them | |
68 | into array BBS, that will be allocated large enough to contain them. | |
35b07080 ZD |
69 | E->dest must have exactly one predecessor for this to work (it is |
70 | easy to achieve and we do not put it here because we do not want to | |
71 | alter anything by this function). The number of basic blocks in the | |
72 | path is returned. */ | |
617b465c | 73 | static int |
d47cc544 | 74 | find_path (edge e, basic_block **bbs) |
617b465c | 75 | { |
628f6a4e | 76 | gcc_assert (EDGE_COUNT (e->dest->preds) <= 1); |
617b465c ZD |
77 | |
78 | /* Find bbs in the path. */ | |
5ed6ace5 | 79 | *bbs = XCNEWVEC (basic_block, n_basic_blocks); |
617b465c | 80 | return dfs_enumerate_from (e->dest, 0, rpe_enum_p, *bbs, |
d47cc544 | 81 | n_basic_blocks, e->dest); |
617b465c ZD |
82 | } |
83 | ||
d73be268 | 84 | /* Fix placement of basic block BB inside loop hierarchy -- |
617b465c ZD |
85 | Let L be a loop to that BB belongs. Then every successor of BB must either |
86 | 1) belong to some superloop of loop L, or | |
87 | 2) be a header of loop K such that K->outer is superloop of L | |
88 | Returns true if we had to move BB into other loop to enforce this condition, | |
89 | false if the placement of BB was already correct (provided that placements | |
90 | of its successors are correct). */ | |
91 | static bool | |
d73be268 | 92 | fix_bb_placement (basic_block bb) |
617b465c ZD |
93 | { |
94 | edge e; | |
628f6a4e | 95 | edge_iterator ei; |
d73be268 | 96 | struct loop *loop = current_loops->tree_root, *act; |
617b465c | 97 | |
628f6a4e | 98 | FOR_EACH_EDGE (e, ei, bb->succs) |
617b465c ZD |
99 | { |
100 | if (e->dest == EXIT_BLOCK_PTR) | |
101 | continue; | |
102 | ||
103 | act = e->dest->loop_father; | |
104 | if (act->header == e->dest) | |
9ba025a2 | 105 | act = loop_outer (act); |
617b465c ZD |
106 | |
107 | if (flow_loop_nested_p (loop, act)) | |
108 | loop = act; | |
109 | } | |
110 | ||
111 | if (loop == bb->loop_father) | |
112 | return false; | |
113 | ||
114 | remove_bb_from_loops (bb); | |
115 | add_bb_to_loop (bb, loop); | |
116 | ||
117 | return true; | |
118 | } | |
119 | ||
b4c1c7e3 ZD |
120 | /* Fix placement of LOOP inside loop tree, i.e. find the innermost superloop |
121 | of LOOP to that leads at least one exit edge of LOOP, and set it | |
122 | as the immediate superloop of LOOP. Return true if the immediate superloop | |
123 | of LOOP changed. */ | |
124 | ||
125 | static bool | |
126 | fix_loop_placement (struct loop *loop) | |
127 | { | |
128 | unsigned i; | |
129 | edge e; | |
130 | VEC (edge, heap) *exits = get_loop_exit_edges (loop); | |
131 | struct loop *father = current_loops->tree_root, *act; | |
132 | bool ret = false; | |
133 | ||
134 | for (i = 0; VEC_iterate (edge, exits, i, e); i++) | |
135 | { | |
136 | act = find_common_loop (loop, e->dest->loop_father); | |
137 | if (flow_loop_nested_p (father, act)) | |
138 | father = act; | |
139 | } | |
140 | ||
9ba025a2 | 141 | if (father != loop_outer (loop)) |
b4c1c7e3 | 142 | { |
9ba025a2 | 143 | for (act = loop_outer (loop); act != father; act = loop_outer (act)) |
b4c1c7e3 ZD |
144 | act->num_nodes -= loop->num_nodes; |
145 | flow_loop_tree_node_remove (loop); | |
146 | flow_loop_tree_node_add (father, loop); | |
147 | ||
148 | /* The exit edges of LOOP no longer exits its original immediate | |
149 | superloops; remove them from the appropriate exit lists. */ | |
150 | for (i = 0; VEC_iterate (edge, exits, i, e); i++) | |
151 | rescan_loop_exit (e, false, false); | |
152 | ||
153 | ret = true; | |
154 | } | |
155 | ||
156 | VEC_free (edge, heap, exits); | |
157 | return ret; | |
158 | } | |
159 | ||
617b465c ZD |
160 | /* Fix placements of basic blocks inside loop hierarchy stored in loops; i.e. |
161 | enforce condition condition stated in description of fix_bb_placement. We | |
162 | start from basic block FROM that had some of its successors removed, so that | |
163 | his placement no longer has to be correct, and iteratively fix placement of | |
164 | its predecessors that may change if placement of FROM changed. Also fix | |
165 | placement of subloops of FROM->loop_father, that might also be altered due | |
4d6922ee | 166 | to this change; the condition for them is similar, except that instead of |
dc14f191 ZD |
167 | successors we consider edges coming out of the loops. |
168 | ||
169 | If the changes may invalidate the information about irreducible regions, | |
170 | IRRED_INVALIDATED is set to true. */ | |
171 | ||
617b465c | 172 | static void |
d73be268 | 173 | fix_bb_placements (basic_block from, |
dc14f191 | 174 | bool *irred_invalidated) |
617b465c ZD |
175 | { |
176 | sbitmap in_queue; | |
177 | basic_block *queue, *qtop, *qbeg, *qend; | |
178 | struct loop *base_loop; | |
179 | edge e; | |
180 | ||
181 | /* We pass through blocks back-reachable from FROM, testing whether some | |
182 | of their successors moved to outer loop. It may be necessary to | |
183 | iterate several times, but it is finite, as we stop unless we move | |
184 | the basic block up the loop structure. The whole story is a bit | |
185 | more complicated due to presence of subloops, those are moved using | |
186 | fix_loop_placement. */ | |
187 | ||
188 | base_loop = from->loop_father; | |
d73be268 | 189 | if (base_loop == current_loops->tree_root) |
617b465c ZD |
190 | return; |
191 | ||
192 | in_queue = sbitmap_alloc (last_basic_block); | |
193 | sbitmap_zero (in_queue); | |
194 | SET_BIT (in_queue, from->index); | |
195 | /* Prevent us from going out of the base_loop. */ | |
196 | SET_BIT (in_queue, base_loop->header->index); | |
197 | ||
5ed6ace5 | 198 | queue = XNEWVEC (basic_block, base_loop->num_nodes + 1); |
617b465c ZD |
199 | qtop = queue + base_loop->num_nodes + 1; |
200 | qbeg = queue; | |
201 | qend = queue + 1; | |
202 | *qbeg = from; | |
203 | ||
204 | while (qbeg != qend) | |
205 | { | |
628f6a4e | 206 | edge_iterator ei; |
617b465c ZD |
207 | from = *qbeg; |
208 | qbeg++; | |
209 | if (qbeg == qtop) | |
210 | qbeg = queue; | |
211 | RESET_BIT (in_queue, from->index); | |
212 | ||
213 | if (from->loop_father->header == from) | |
214 | { | |
215 | /* Subloop header, maybe move the loop upward. */ | |
216 | if (!fix_loop_placement (from->loop_father)) | |
217 | continue; | |
218 | } | |
219 | else | |
220 | { | |
221 | /* Ordinary basic block. */ | |
d73be268 | 222 | if (!fix_bb_placement (from)) |
617b465c ZD |
223 | continue; |
224 | } | |
225 | ||
dc14f191 ZD |
226 | FOR_EACH_EDGE (e, ei, from->succs) |
227 | { | |
228 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
229 | *irred_invalidated = true; | |
230 | } | |
231 | ||
617b465c | 232 | /* Something has changed, insert predecessors into queue. */ |
628f6a4e | 233 | FOR_EACH_EDGE (e, ei, from->preds) |
617b465c ZD |
234 | { |
235 | basic_block pred = e->src; | |
236 | struct loop *nca; | |
237 | ||
dc14f191 ZD |
238 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
239 | *irred_invalidated = true; | |
240 | ||
617b465c ZD |
241 | if (TEST_BIT (in_queue, pred->index)) |
242 | continue; | |
243 | ||
d329e058 | 244 | /* If it is subloop, then it either was not moved, or |
617b465c ZD |
245 | the path up the loop tree from base_loop do not contain |
246 | it. */ | |
247 | nca = find_common_loop (pred->loop_father, base_loop); | |
248 | if (pred->loop_father != base_loop | |
249 | && (nca == base_loop | |
250 | || nca != pred->loop_father)) | |
251 | pred = pred->loop_father->header; | |
252 | else if (!flow_loop_nested_p (from->loop_father, pred->loop_father)) | |
253 | { | |
254 | /* No point in processing it. */ | |
255 | continue; | |
256 | } | |
257 | ||
258 | if (TEST_BIT (in_queue, pred->index)) | |
259 | continue; | |
260 | ||
261 | /* Schedule the basic block. */ | |
262 | *qend = pred; | |
263 | qend++; | |
264 | if (qend == qtop) | |
265 | qend = queue; | |
266 | SET_BIT (in_queue, pred->index); | |
267 | } | |
268 | } | |
269 | free (in_queue); | |
270 | free (queue); | |
271 | } | |
272 | ||
273 | /* Removes path beginning at edge E, i.e. remove basic blocks dominated by E | |
d73be268 ZD |
274 | and update loop structures and dominators. Return true if we were able |
275 | to remove the path, false otherwise (and nothing is affected then). */ | |
617b465c | 276 | bool |
d73be268 | 277 | remove_path (edge e) |
617b465c ZD |
278 | { |
279 | edge ae; | |
66f97d31 ZD |
280 | basic_block *rem_bbs, *bord_bbs, from, bb; |
281 | VEC (basic_block, heap) *dom_bbs; | |
282 | int i, nrem, n_bord_bbs, nreml; | |
617b465c | 283 | sbitmap seen; |
14fa2cc0 | 284 | bool irred_invalidated = false; |
598ec7bd | 285 | struct loop **deleted_loop; |
617b465c | 286 | |
14fa2cc0 | 287 | if (!can_remove_branch_p (e)) |
35b07080 ZD |
288 | return false; |
289 | ||
dc14f191 ZD |
290 | /* Keep track of whether we need to update information about irreducible |
291 | regions. This is the case if the removed area is a part of the | |
292 | irreducible region, or if the set of basic blocks that belong to a loop | |
293 | that is inside an irreducible region is changed, or if such a loop is | |
294 | removed. */ | |
295 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
296 | irred_invalidated = true; | |
297 | ||
35b07080 ZD |
298 | /* We need to check whether basic blocks are dominated by the edge |
299 | e, but we only have basic block dominators. This is easy to | |
300 | fix -- when e->dest has exactly one predecessor, this corresponds | |
301 | to blocks dominated by e->dest, if not, split the edge. */ | |
c5cbcccf | 302 | if (!single_pred_p (e->dest)) |
598ec7bd | 303 | e = single_pred_edge (split_edge (e)); |
35b07080 ZD |
304 | |
305 | /* It may happen that by removing path we remove one or more loops | |
306 | we belong to. In this case first unloop the loops, then proceed | |
307 | normally. We may assume that e->dest is not a header of any loop, | |
308 | as it now has exactly one predecessor. */ | |
9ba025a2 | 309 | while (loop_outer (e->src->loop_father) |
d47cc544 | 310 | && dominated_by_p (CDI_DOMINATORS, |
35b07080 | 311 | e->src->loop_father->latch, e->dest)) |
d73be268 | 312 | unloop (e->src->loop_father, &irred_invalidated); |
d329e058 | 313 | |
35b07080 | 314 | /* Identify the path. */ |
d47cc544 | 315 | nrem = find_path (e, &rem_bbs); |
617b465c ZD |
316 | |
317 | n_bord_bbs = 0; | |
5ed6ace5 | 318 | bord_bbs = XCNEWVEC (basic_block, n_basic_blocks); |
617b465c ZD |
319 | seen = sbitmap_alloc (last_basic_block); |
320 | sbitmap_zero (seen); | |
321 | ||
322 | /* Find "border" hexes -- i.e. those with predecessor in removed path. */ | |
323 | for (i = 0; i < nrem; i++) | |
324 | SET_BIT (seen, rem_bbs[i]->index); | |
35b07080 | 325 | for (i = 0; i < nrem; i++) |
617b465c | 326 | { |
628f6a4e | 327 | edge_iterator ei; |
35b07080 | 328 | bb = rem_bbs[i]; |
628f6a4e | 329 | FOR_EACH_EDGE (ae, ei, rem_bbs[i]->succs) |
35b07080 ZD |
330 | if (ae->dest != EXIT_BLOCK_PTR && !TEST_BIT (seen, ae->dest->index)) |
331 | { | |
332 | SET_BIT (seen, ae->dest->index); | |
333 | bord_bbs[n_bord_bbs++] = ae->dest; | |
dc14f191 ZD |
334 | |
335 | if (ae->flags & EDGE_IRREDUCIBLE_LOOP) | |
336 | irred_invalidated = true; | |
35b07080 | 337 | } |
617b465c | 338 | } |
617b465c ZD |
339 | |
340 | /* Remove the path. */ | |
341 | from = e->src; | |
14fa2cc0 | 342 | remove_branch (e); |
66f97d31 | 343 | dom_bbs = NULL; |
617b465c ZD |
344 | |
345 | /* Cancel loops contained in the path. */ | |
598ec7bd ZD |
346 | deleted_loop = XNEWVEC (struct loop *, nrem); |
347 | nreml = 0; | |
617b465c ZD |
348 | for (i = 0; i < nrem; i++) |
349 | if (rem_bbs[i]->loop_father->header == rem_bbs[i]) | |
598ec7bd | 350 | deleted_loop[nreml++] = rem_bbs[i]->loop_father; |
617b465c | 351 | |
d47cc544 | 352 | remove_bbs (rem_bbs, nrem); |
617b465c ZD |
353 | free (rem_bbs); |
354 | ||
598ec7bd | 355 | for (i = 0; i < nreml; i++) |
d73be268 | 356 | cancel_loop_tree (deleted_loop[i]); |
598ec7bd ZD |
357 | free (deleted_loop); |
358 | ||
35b07080 | 359 | /* Find blocks whose dominators may be affected. */ |
617b465c ZD |
360 | sbitmap_zero (seen); |
361 | for (i = 0; i < n_bord_bbs; i++) | |
362 | { | |
d47cc544 | 363 | basic_block ldom; |
617b465c | 364 | |
d47cc544 | 365 | bb = get_immediate_dominator (CDI_DOMINATORS, bord_bbs[i]); |
617b465c ZD |
366 | if (TEST_BIT (seen, bb->index)) |
367 | continue; | |
368 | SET_BIT (seen, bb->index); | |
369 | ||
d47cc544 SB |
370 | for (ldom = first_dom_son (CDI_DOMINATORS, bb); |
371 | ldom; | |
372 | ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
373 | if (!dominated_by_p (CDI_DOMINATORS, from, ldom)) | |
66f97d31 | 374 | VEC_safe_push (basic_block, heap, dom_bbs, ldom); |
617b465c ZD |
375 | } |
376 | ||
617b465c ZD |
377 | free (seen); |
378 | ||
379 | /* Recount dominators. */ | |
66f97d31 ZD |
380 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, true); |
381 | VEC_free (basic_block, heap, dom_bbs); | |
35b07080 ZD |
382 | free (bord_bbs); |
383 | ||
617b465c ZD |
384 | /* Fix placements of basic blocks inside loops and the placement of |
385 | loops in the loop tree. */ | |
d73be268 ZD |
386 | fix_bb_placements (from, &irred_invalidated); |
387 | fix_loop_placements (from->loop_father, &irred_invalidated); | |
dc14f191 ZD |
388 | |
389 | if (irred_invalidated | |
f87000d0 | 390 | && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
d73be268 | 391 | mark_irreducible_loops (); |
617b465c ZD |
392 | |
393 | return true; | |
394 | } | |
395 | ||
89f8f30f ZD |
396 | /* Creates place for a new LOOP in loops structure. */ |
397 | ||
398 | static void | |
399 | place_new_loop (struct loop *loop) | |
617b465c | 400 | { |
89f8f30f | 401 | loop->num = number_of_loops (); |
9e2f83a5 | 402 | VEC_safe_push (loop_p, gc, current_loops->larray, loop); |
617b465c ZD |
403 | } |
404 | ||
405 | /* Given LOOP structure with filled header and latch, find the body of the | |
d73be268 | 406 | corresponding loop and add it to loops tree. Insert the LOOP as a son of |
598ec7bd ZD |
407 | outer. */ |
408 | ||
89f8f30f | 409 | void |
d73be268 | 410 | add_loop (struct loop *loop, struct loop *outer) |
617b465c ZD |
411 | { |
412 | basic_block *bbs; | |
413 | int i, n; | |
89f8f30f | 414 | struct loop *subloop; |
d24a32a1 ZD |
415 | edge e; |
416 | edge_iterator ei; | |
d329e058 | 417 | |
617b465c | 418 | /* Add it to loop structure. */ |
d73be268 | 419 | place_new_loop (loop); |
598ec7bd | 420 | flow_loop_tree_node_add (outer, loop); |
617b465c ZD |
421 | |
422 | /* Find its nodes. */ | |
89f8f30f ZD |
423 | bbs = XNEWVEC (basic_block, n_basic_blocks); |
424 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks); | |
617b465c ZD |
425 | |
426 | for (i = 0; i < n; i++) | |
598ec7bd | 427 | { |
89f8f30f ZD |
428 | if (bbs[i]->loop_father == outer) |
429 | { | |
430 | remove_bb_from_loops (bbs[i]); | |
431 | add_bb_to_loop (bbs[i], loop); | |
432 | continue; | |
433 | } | |
434 | ||
435 | loop->num_nodes++; | |
436 | ||
437 | /* If we find a direct subloop of OUTER, move it to LOOP. */ | |
438 | subloop = bbs[i]->loop_father; | |
9ba025a2 | 439 | if (loop_outer (subloop) == outer |
89f8f30f ZD |
440 | && subloop->header == bbs[i]) |
441 | { | |
442 | flow_loop_tree_node_remove (subloop); | |
443 | flow_loop_tree_node_add (loop, subloop); | |
444 | } | |
598ec7bd | 445 | } |
617b465c | 446 | |
d24a32a1 ZD |
447 | /* Update the information about loop exit edges. */ |
448 | for (i = 0; i < n; i++) | |
449 | { | |
450 | FOR_EACH_EDGE (e, ei, bbs[i]->succs) | |
451 | { | |
452 | rescan_loop_exit (e, false, false); | |
453 | } | |
454 | } | |
455 | ||
617b465c ZD |
456 | free (bbs); |
457 | } | |
458 | ||
617b465c | 459 | /* Multiply all frequencies in LOOP by NUM/DEN. */ |
03cb2019 | 460 | void |
d329e058 | 461 | scale_loop_frequencies (struct loop *loop, int num, int den) |
617b465c ZD |
462 | { |
463 | basic_block *bbs; | |
464 | ||
465 | bbs = get_loop_body (loop); | |
33156717 | 466 | scale_bbs_frequencies_int (bbs, loop->num_nodes, num, den); |
617b465c ZD |
467 | free (bbs); |
468 | } | |
469 | ||
f8bf9252 SP |
470 | /* Recompute dominance information for basic blocks outside LOOP. */ |
471 | ||
472 | static void | |
473 | update_dominators_in_loop (struct loop *loop) | |
474 | { | |
475 | VEC (basic_block, heap) *dom_bbs = NULL; | |
476 | sbitmap seen; | |
477 | basic_block *body; | |
478 | unsigned i; | |
479 | ||
480 | seen = sbitmap_alloc (last_basic_block); | |
481 | sbitmap_zero (seen); | |
482 | body = get_loop_body (loop); | |
483 | ||
484 | for (i = 0; i < loop->num_nodes; i++) | |
485 | SET_BIT (seen, body[i]->index); | |
486 | ||
487 | for (i = 0; i < loop->num_nodes; i++) | |
488 | { | |
489 | basic_block ldom; | |
490 | ||
491 | for (ldom = first_dom_son (CDI_DOMINATORS, body[i]); | |
492 | ldom; | |
493 | ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
494 | if (!TEST_BIT (seen, ldom->index)) | |
495 | { | |
496 | SET_BIT (seen, ldom->index); | |
497 | VEC_safe_push (basic_block, heap, dom_bbs, ldom); | |
498 | } | |
499 | } | |
500 | ||
501 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false); | |
502 | free (body); | |
503 | free (seen); | |
504 | VEC_free (basic_block, heap, dom_bbs); | |
505 | } | |
506 | ||
507 | /* Creates an if region as shown above. CONDITION is used to create | |
508 | the test for the if. | |
509 | ||
510 | | | |
511 | | ------------- ------------- | |
512 | | | pred_bb | | pred_bb | | |
513 | | ------------- ------------- | |
514 | | | | | |
515 | | | | ENTRY_EDGE | |
516 | | | ENTRY_EDGE V | |
517 | | | ====> ------------- | |
518 | | | | cond_bb | | |
519 | | | | CONDITION | | |
520 | | | ------------- | |
521 | | V / \ | |
522 | | ------------- e_false / \ e_true | |
523 | | | succ_bb | V V | |
524 | | ------------- ----------- ----------- | |
525 | | | false_bb | | true_bb | | |
526 | | ----------- ----------- | |
527 | | \ / | |
528 | | \ / | |
529 | | V V | |
530 | | ------------- | |
531 | | | join_bb | | |
532 | | ------------- | |
533 | | | exit_edge (result) | |
534 | | V | |
535 | | ----------- | |
536 | | | succ_bb | | |
537 | | ----------- | |
538 | | | |
539 | */ | |
540 | ||
541 | edge | |
542 | create_empty_if_region_on_edge (edge entry_edge, tree condition) | |
543 | { | |
544 | ||
545 | basic_block succ_bb, cond_bb, true_bb, false_bb, join_bb; | |
546 | edge e_true, e_false, exit_edge; | |
547 | gimple cond_stmt; | |
548 | tree simple_cond; | |
549 | gimple_stmt_iterator gsi; | |
550 | ||
551 | succ_bb = entry_edge->dest; | |
552 | cond_bb = split_edge (entry_edge); | |
553 | ||
554 | /* Insert condition in cond_bb. */ | |
555 | gsi = gsi_last_bb (cond_bb); | |
556 | simple_cond = | |
557 | force_gimple_operand_gsi (&gsi, condition, true, NULL, | |
558 | false, GSI_NEW_STMT); | |
559 | cond_stmt = gimple_build_cond_from_tree (simple_cond, NULL_TREE, NULL_TREE); | |
560 | gsi = gsi_last_bb (cond_bb); | |
561 | gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT); | |
562 | ||
563 | join_bb = split_edge (single_succ_edge (cond_bb)); | |
564 | ||
565 | e_true = single_succ_edge (cond_bb); | |
566 | true_bb = split_edge (e_true); | |
567 | ||
568 | e_false = make_edge (cond_bb, join_bb, 0); | |
569 | false_bb = split_edge (e_false); | |
570 | ||
571 | e_true->flags &= ~EDGE_FALLTHRU; | |
572 | e_true->flags |= EDGE_TRUE_VALUE; | |
573 | e_false->flags &= ~EDGE_FALLTHRU; | |
574 | e_false->flags |= EDGE_FALSE_VALUE; | |
575 | ||
576 | set_immediate_dominator (CDI_DOMINATORS, cond_bb, entry_edge->src); | |
577 | set_immediate_dominator (CDI_DOMINATORS, true_bb, cond_bb); | |
578 | set_immediate_dominator (CDI_DOMINATORS, false_bb, cond_bb); | |
579 | set_immediate_dominator (CDI_DOMINATORS, join_bb, cond_bb); | |
580 | ||
581 | exit_edge = single_succ_edge (join_bb); | |
582 | ||
583 | if (single_pred_p (exit_edge->dest)) | |
584 | set_immediate_dominator (CDI_DOMINATORS, exit_edge->dest, join_bb); | |
585 | ||
586 | return exit_edge; | |
587 | } | |
588 | ||
589 | /* create_empty_loop_on_edge | |
590 | | | |
591 | | ------------- ------------------------ | |
592 | | | pred_bb | | pred_bb | | |
593 | | ------------- | IV_0 = INITIAL_VALUE | | |
594 | | | ------------------------ | |
595 | | | ______ | ENTRY_EDGE | |
596 | | | ENTRY_EDGE / V V | |
597 | | | ====> | ----------------------------- | |
598 | | | | | IV_BEFORE = phi (IV_0, IV) | | |
599 | | | | | loop_header | | |
600 | | V | | IV_BEFORE <= UPPER_BOUND | | |
601 | | ------------- | -----------------------\----- | |
602 | | | succ_bb | | | \ | |
603 | | ------------- | | \ exit_e | |
604 | | | V V--------- | |
605 | | | -------------- | succ_bb | | |
606 | | | | loop_latch | ---------- | |
607 | | | |IV = IV_BEFORE + STRIDE | |
608 | | | -------------- | |
609 | | \ / | |
610 | | \ ___ / | |
611 | ||
612 | Creates an empty loop as shown above, the IV_BEFORE is the SSA_NAME | |
613 | that is used before the increment of IV. IV_BEFORE should be used for | |
614 | adding code to the body that uses the IV. OUTER is the outer loop in | |
615 | which the new loop should be inserted. */ | |
616 | ||
617 | struct loop * | |
618 | create_empty_loop_on_edge (edge entry_edge, | |
619 | tree initial_value, | |
620 | tree stride, tree upper_bound, | |
621 | tree iv, | |
622 | tree *iv_before, | |
623 | struct loop *outer) | |
624 | { | |
625 | basic_block loop_header, loop_latch, succ_bb, pred_bb; | |
626 | struct loop *loop; | |
627 | int freq; | |
628 | gcov_type cnt; | |
629 | gimple_stmt_iterator gsi; | |
630 | bool insert_after; | |
631 | gimple_seq stmts; | |
632 | gimple cond_expr; | |
633 | tree exit_test; | |
634 | edge exit_e; | |
635 | int prob; | |
636 | tree upper_bound_gimplified; | |
637 | ||
638 | gcc_assert (entry_edge && initial_value && stride && upper_bound && iv); | |
639 | ||
640 | /* Create header, latch and wire up the loop. */ | |
641 | pred_bb = entry_edge->src; | |
642 | loop_header = split_edge (entry_edge); | |
643 | loop_latch = split_edge (single_succ_edge (loop_header)); | |
644 | succ_bb = single_succ (loop_latch); | |
645 | make_edge (loop_header, succ_bb, 0); | |
646 | redirect_edge_succ_nodup (single_succ_edge (loop_latch), loop_header); | |
647 | ||
648 | /* Set immediate dominator information. */ | |
649 | set_immediate_dominator (CDI_DOMINATORS, loop_header, pred_bb); | |
650 | set_immediate_dominator (CDI_DOMINATORS, loop_latch, loop_header); | |
651 | set_immediate_dominator (CDI_DOMINATORS, succ_bb, loop_header); | |
652 | ||
653 | /* Initialize a loop structure and put it in a loop hierarchy. */ | |
654 | loop = alloc_loop (); | |
655 | loop->header = loop_header; | |
656 | loop->latch = loop_latch; | |
657 | add_loop (loop, outer); | |
658 | ||
659 | /* TODO: Fix frequencies and counts. */ | |
660 | freq = EDGE_FREQUENCY (entry_edge); | |
661 | cnt = entry_edge->count; | |
662 | ||
663 | prob = REG_BR_PROB_BASE / 2; | |
664 | ||
665 | scale_loop_frequencies (loop, REG_BR_PROB_BASE - prob, REG_BR_PROB_BASE); | |
666 | ||
667 | /* Update dominators. */ | |
668 | update_dominators_in_loop (loop); | |
669 | ||
670 | /* Construct IV code in loop. */ | |
671 | initial_value = force_gimple_operand (initial_value, &stmts, true, iv); | |
672 | if (stmts) | |
673 | { | |
674 | gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts); | |
675 | gsi_commit_edge_inserts (); | |
676 | } | |
677 | ||
678 | standard_iv_increment_position (loop, &gsi, &insert_after); | |
679 | create_iv (initial_value, stride, iv, loop, &gsi, insert_after, | |
680 | iv_before, NULL); | |
681 | ||
682 | /* Modify edge flags. */ | |
683 | exit_e = single_exit (loop); | |
684 | exit_e->flags = EDGE_LOOP_EXIT | EDGE_FALSE_VALUE; | |
685 | single_pred_edge (loop_latch)->flags = EDGE_TRUE_VALUE; | |
686 | ||
687 | gsi = gsi_last_bb (exit_e->src); | |
688 | ||
689 | upper_bound_gimplified = | |
690 | force_gimple_operand_gsi (&gsi, upper_bound, true, NULL, | |
691 | false, GSI_NEW_STMT); | |
692 | gsi = gsi_last_bb (exit_e->src); | |
693 | ||
694 | cond_expr = gimple_build_cond | |
695 | (LE_EXPR, *iv_before, upper_bound_gimplified, NULL_TREE, NULL_TREE); | |
696 | ||
697 | exit_test = gimple_cond_lhs (cond_expr); | |
698 | exit_test = force_gimple_operand_gsi (&gsi, exit_test, true, NULL, | |
699 | false, GSI_NEW_STMT); | |
700 | gimple_cond_set_lhs (cond_expr, exit_test); | |
701 | gsi = gsi_last_bb (exit_e->src); | |
702 | gsi_insert_after (&gsi, cond_expr, GSI_NEW_STMT); | |
703 | ||
704 | return loop; | |
705 | } | |
706 | ||
617b465c | 707 | /* Make area between HEADER_EDGE and LATCH_EDGE a loop by connecting |
d73be268 | 708 | latch to header and update loop tree and dominators |
617b465c ZD |
709 | accordingly. Everything between them plus LATCH_EDGE destination must |
710 | be dominated by HEADER_EDGE destination, and back-reachable from | |
711 | LATCH_EDGE source. HEADER_EDGE is redirected to basic block SWITCH_BB, | |
5132abc2 KH |
712 | FALSE_EDGE of SWITCH_BB to original destination of HEADER_EDGE and |
713 | TRUE_EDGE of SWITCH_BB to original destination of LATCH_EDGE. | |
03cb2019 ZD |
714 | Returns the newly created loop. Frequencies and counts in the new loop |
715 | are scaled by FALSE_SCALE and in the old one by TRUE_SCALE. */ | |
50654f6c | 716 | |
617b465c | 717 | struct loop * |
d73be268 | 718 | loopify (edge latch_edge, edge header_edge, |
5132abc2 | 719 | basic_block switch_bb, edge true_edge, edge false_edge, |
03cb2019 | 720 | bool redirect_all_edges, unsigned true_scale, unsigned false_scale) |
617b465c ZD |
721 | { |
722 | basic_block succ_bb = latch_edge->dest; | |
723 | basic_block pred_bb = header_edge->src; | |
6270df4c | 724 | struct loop *loop = alloc_loop (); |
9ba025a2 | 725 | struct loop *outer = loop_outer (succ_bb->loop_father); |
03cb2019 | 726 | int freq; |
617b465c ZD |
727 | gcov_type cnt; |
728 | edge e; | |
628f6a4e | 729 | edge_iterator ei; |
617b465c ZD |
730 | |
731 | loop->header = header_edge->dest; | |
732 | loop->latch = latch_edge->src; | |
733 | ||
734 | freq = EDGE_FREQUENCY (header_edge); | |
735 | cnt = header_edge->count; | |
617b465c ZD |
736 | |
737 | /* Redirect edges. */ | |
738 | loop_redirect_edge (latch_edge, loop->header); | |
5132abc2 | 739 | loop_redirect_edge (true_edge, succ_bb); |
50654f6c | 740 | |
92fc4a2f ZD |
741 | /* During loop versioning, one of the switch_bb edge is already properly |
742 | set. Do not redirect it again unless redirect_all_edges is true. */ | |
743 | if (redirect_all_edges) | |
744 | { | |
745 | loop_redirect_edge (header_edge, switch_bb); | |
c22cacf3 MS |
746 | loop_redirect_edge (false_edge, loop->header); |
747 | ||
92fc4a2f ZD |
748 | /* Update dominators. */ |
749 | set_immediate_dominator (CDI_DOMINATORS, switch_bb, pred_bb); | |
750 | set_immediate_dominator (CDI_DOMINATORS, loop->header, switch_bb); | |
751 | } | |
50654f6c | 752 | |
d47cc544 | 753 | set_immediate_dominator (CDI_DOMINATORS, succ_bb, switch_bb); |
617b465c ZD |
754 | |
755 | /* Compute new loop. */ | |
d73be268 | 756 | add_loop (loop, outer); |
617b465c ZD |
757 | |
758 | /* Add switch_bb to appropriate loop. */ | |
598ec7bd ZD |
759 | if (switch_bb->loop_father) |
760 | remove_bb_from_loops (switch_bb); | |
617b465c ZD |
761 | add_bb_to_loop (switch_bb, outer); |
762 | ||
763 | /* Fix frequencies. */ | |
03cb2019 ZD |
764 | if (redirect_all_edges) |
765 | { | |
766 | switch_bb->frequency = freq; | |
767 | switch_bb->count = cnt; | |
768 | FOR_EACH_EDGE (e, ei, switch_bb->succs) | |
769 | { | |
770 | e->count = (switch_bb->count * e->probability) / REG_BR_PROB_BASE; | |
771 | } | |
772 | } | |
773 | scale_loop_frequencies (loop, false_scale, REG_BR_PROB_BASE); | |
774 | scale_loop_frequencies (succ_bb->loop_father, true_scale, REG_BR_PROB_BASE); | |
f8bf9252 | 775 | update_dominators_in_loop (loop); |
617b465c ZD |
776 | |
777 | return loop; | |
778 | } | |
779 | ||
d73be268 | 780 | /* Remove the latch edge of a LOOP and update loops to indicate that |
35b07080 | 781 | the LOOP was removed. After this function, original loop latch will |
dc14f191 ZD |
782 | have no successor, which caller is expected to fix somehow. |
783 | ||
784 | If this may cause the information about irreducible regions to become | |
785 | invalid, IRRED_INVALIDATED is set to true. */ | |
786 | ||
25a6c68b | 787 | static void |
d73be268 | 788 | unloop (struct loop *loop, bool *irred_invalidated) |
35b07080 ZD |
789 | { |
790 | basic_block *body; | |
791 | struct loop *ploop; | |
792 | unsigned i, n; | |
793 | basic_block latch = loop->latch; | |
dc14f191 ZD |
794 | bool dummy = false; |
795 | ||
796 | if (loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP) | |
797 | *irred_invalidated = true; | |
35b07080 | 798 | |
e0bb17a8 | 799 | /* This is relatively straightforward. The dominators are unchanged, as |
35b07080 ZD |
800 | loop header dominates loop latch, so the only thing we have to care of |
801 | is the placement of loops and basic blocks inside the loop tree. We | |
802 | move them all to the loop->outer, and then let fix_bb_placements do | |
803 | its work. */ | |
804 | ||
805 | body = get_loop_body (loop); | |
35b07080 ZD |
806 | n = loop->num_nodes; |
807 | for (i = 0; i < n; i++) | |
808 | if (body[i]->loop_father == loop) | |
809 | { | |
810 | remove_bb_from_loops (body[i]); | |
9ba025a2 | 811 | add_bb_to_loop (body[i], loop_outer (loop)); |
35b07080 ZD |
812 | } |
813 | free(body); | |
814 | ||
815 | while (loop->inner) | |
816 | { | |
817 | ploop = loop->inner; | |
818 | flow_loop_tree_node_remove (ploop); | |
9ba025a2 | 819 | flow_loop_tree_node_add (loop_outer (loop), ploop); |
35b07080 ZD |
820 | } |
821 | ||
822 | /* Remove the loop and free its data. */ | |
42fd6772 | 823 | delete_loop (loop); |
35b07080 | 824 | |
c5cbcccf | 825 | remove_edge (single_succ_edge (latch)); |
dc14f191 ZD |
826 | |
827 | /* We do not pass IRRED_INVALIDATED to fix_bb_placements here, as even if | |
828 | there is an irreducible region inside the cancelled loop, the flags will | |
829 | be still correct. */ | |
d73be268 | 830 | fix_bb_placements (latch, &dummy); |
35b07080 ZD |
831 | } |
832 | ||
617b465c ZD |
833 | /* Fix placement of superloops of LOOP inside loop tree, i.e. ensure that |
834 | condition stated in description of fix_loop_placement holds for them. | |
835 | It is used in case when we removed some edges coming out of LOOP, which | |
dc14f191 ZD |
836 | may cause the right placement of LOOP inside loop tree to change. |
837 | ||
838 | IRRED_INVALIDATED is set to true if a change in the loop structures might | |
839 | invalidate the information about irreducible regions. */ | |
840 | ||
617b465c | 841 | static void |
d73be268 | 842 | fix_loop_placements (struct loop *loop, bool *irred_invalidated) |
617b465c ZD |
843 | { |
844 | struct loop *outer; | |
845 | ||
9ba025a2 | 846 | while (loop_outer (loop)) |
617b465c | 847 | { |
9ba025a2 | 848 | outer = loop_outer (loop); |
617b465c | 849 | if (!fix_loop_placement (loop)) |
c22cacf3 | 850 | break; |
1548580c EB |
851 | |
852 | /* Changing the placement of a loop in the loop tree may alter the | |
853 | validity of condition 2) of the description of fix_bb_placement | |
854 | for its preheader, because the successor is the header and belongs | |
855 | to the loop. So call fix_bb_placements to fix up the placement | |
856 | of the preheader and (possibly) of its predecessors. */ | |
d73be268 | 857 | fix_bb_placements (loop_preheader_edge (loop)->src, |
dc14f191 | 858 | irred_invalidated); |
617b465c ZD |
859 | loop = outer; |
860 | } | |
861 | } | |
862 | ||
617b465c | 863 | /* Copies copy of LOOP as subloop of TARGET loop, placing newly |
d73be268 | 864 | created loop into loops structure. */ |
f67d92e9 | 865 | struct loop * |
d73be268 | 866 | duplicate_loop (struct loop *loop, struct loop *target) |
617b465c ZD |
867 | { |
868 | struct loop *cloop; | |
6270df4c | 869 | cloop = alloc_loop (); |
d73be268 | 870 | place_new_loop (cloop); |
617b465c | 871 | |
99f8a411 | 872 | /* Mark the new loop as copy of LOOP. */ |
561e8a90 | 873 | set_loop_copy (loop, cloop); |
617b465c ZD |
874 | |
875 | /* Add it to target. */ | |
876 | flow_loop_tree_node_add (target, cloop); | |
877 | ||
878 | return cloop; | |
879 | } | |
880 | ||
881 | /* Copies structure of subloops of LOOP into TARGET loop, placing | |
d73be268 | 882 | newly created loops into loop tree. */ |
d329e058 | 883 | static void |
d73be268 | 884 | duplicate_subloops (struct loop *loop, struct loop *target) |
617b465c ZD |
885 | { |
886 | struct loop *aloop, *cloop; | |
887 | ||
888 | for (aloop = loop->inner; aloop; aloop = aloop->next) | |
889 | { | |
d73be268 ZD |
890 | cloop = duplicate_loop (aloop, target); |
891 | duplicate_subloops (aloop, cloop); | |
617b465c ZD |
892 | } |
893 | } | |
894 | ||
895 | /* Copies structure of subloops of N loops, stored in array COPIED_LOOPS, | |
d73be268 | 896 | into TARGET loop, placing newly created loops into loop tree. */ |
d329e058 | 897 | static void |
d73be268 | 898 | copy_loops_to (struct loop **copied_loops, int n, struct loop *target) |
617b465c ZD |
899 | { |
900 | struct loop *aloop; | |
901 | int i; | |
902 | ||
903 | for (i = 0; i < n; i++) | |
904 | { | |
d73be268 ZD |
905 | aloop = duplicate_loop (copied_loops[i], target); |
906 | duplicate_subloops (copied_loops[i], aloop); | |
617b465c ZD |
907 | } |
908 | } | |
909 | ||
910 | /* Redirects edge E to basic block DEST. */ | |
911 | static void | |
d329e058 | 912 | loop_redirect_edge (edge e, basic_block dest) |
617b465c ZD |
913 | { |
914 | if (e->dest == dest) | |
915 | return; | |
916 | ||
9ee634e3 | 917 | redirect_edge_and_branch_force (e, dest); |
617b465c ZD |
918 | } |
919 | ||
617b465c ZD |
920 | /* Check whether LOOP's body can be duplicated. */ |
921 | bool | |
ed7a4b4b | 922 | can_duplicate_loop_p (const struct loop *loop) |
617b465c | 923 | { |
8d28e87d ZD |
924 | int ret; |
925 | basic_block *bbs = get_loop_body (loop); | |
617b465c | 926 | |
8d28e87d | 927 | ret = can_copy_bbs_p (bbs, loop->num_nodes); |
617b465c | 928 | free (bbs); |
c22cacf3 | 929 | |
8d28e87d | 930 | return ret; |
617b465c ZD |
931 | } |
932 | ||
03cb2019 ZD |
933 | /* Sets probability and count of edge E to zero. The probability and count |
934 | is redistributed evenly to the remaining edges coming from E->src. */ | |
935 | ||
936 | static void | |
937 | set_zero_probability (edge e) | |
938 | { | |
939 | basic_block bb = e->src; | |
940 | edge_iterator ei; | |
941 | edge ae, last = NULL; | |
942 | unsigned n = EDGE_COUNT (bb->succs); | |
943 | gcov_type cnt = e->count, cnt1; | |
944 | unsigned prob = e->probability, prob1; | |
945 | ||
946 | gcc_assert (n > 1); | |
947 | cnt1 = cnt / (n - 1); | |
948 | prob1 = prob / (n - 1); | |
949 | ||
950 | FOR_EACH_EDGE (ae, ei, bb->succs) | |
951 | { | |
952 | if (ae == e) | |
953 | continue; | |
954 | ||
955 | ae->probability += prob1; | |
956 | ae->count += cnt1; | |
957 | last = ae; | |
958 | } | |
959 | ||
960 | /* Move the rest to one of the edges. */ | |
961 | last->probability += prob % (n - 1); | |
962 | last->count += cnt % (n - 1); | |
963 | ||
964 | e->probability = 0; | |
965 | e->count = 0; | |
966 | } | |
967 | ||
8d28e87d | 968 | /* Duplicates body of LOOP to given edge E NDUPL times. Takes care of updating |
d73be268 | 969 | loop structure and dominators. E's destination must be LOOP header for |
8d28e87d ZD |
970 | this to work, i.e. it must be entry or latch edge of this loop; these are |
971 | unique, as the loops must have preheaders for this function to work | |
972 | correctly (in case E is latch, the function unrolls the loop, if E is entry | |
973 | edge, it peels the loop). Store edges created by copying ORIG edge from | |
974 | copies corresponding to set bits in WONT_EXIT bitmap (bit 0 corresponds to | |
975 | original LOOP body, the other copies are numbered in order given by control | |
976 | flow through them) into TO_REMOVE array. Returns false if duplication is | |
977 | impossible. */ | |
ee8c1b05 | 978 | |
1cb7dfc3 | 979 | bool |
d73be268 | 980 | duplicate_loop_to_header_edge (struct loop *loop, edge e, |
d329e058 | 981 | unsigned int ndupl, sbitmap wont_exit, |
ee8c1b05 ZD |
982 | edge orig, VEC (edge, heap) **to_remove, |
983 | int flags) | |
617b465c ZD |
984 | { |
985 | struct loop *target, *aloop; | |
986 | struct loop **orig_loops; | |
987 | unsigned n_orig_loops; | |
988 | basic_block header = loop->header, latch = loop->latch; | |
989 | basic_block *new_bbs, *bbs, *first_active; | |
990 | basic_block new_bb, bb, first_active_latch = NULL; | |
8d28e87d ZD |
991 | edge ae, latch_edge; |
992 | edge spec_edges[2], new_spec_edges[2]; | |
993 | #define SE_LATCH 0 | |
994 | #define SE_ORIG 1 | |
617b465c ZD |
995 | unsigned i, j, n; |
996 | int is_latch = (latch == e->src); | |
997 | int scale_act = 0, *scale_step = NULL, scale_main = 0; | |
03cb2019 | 998 | int scale_after_exit = 0; |
617b465c ZD |
999 | int p, freq_in, freq_le, freq_out_orig; |
1000 | int prob_pass_thru, prob_pass_wont_exit, prob_pass_main; | |
1001 | int add_irreducible_flag; | |
b9a66240 | 1002 | basic_block place_after; |
03cb2019 ZD |
1003 | bitmap bbs_to_scale = NULL; |
1004 | bitmap_iterator bi; | |
617b465c | 1005 | |
341c100f NS |
1006 | gcc_assert (e->dest == loop->header); |
1007 | gcc_assert (ndupl > 0); | |
617b465c ZD |
1008 | |
1009 | if (orig) | |
1010 | { | |
1011 | /* Orig must be edge out of the loop. */ | |
341c100f NS |
1012 | gcc_assert (flow_bb_inside_loop_p (loop, orig->src)); |
1013 | gcc_assert (!flow_bb_inside_loop_p (loop, orig->dest)); | |
617b465c ZD |
1014 | } |
1015 | ||
b9a66240 ZD |
1016 | n = loop->num_nodes; |
1017 | bbs = get_loop_body_in_dom_order (loop); | |
1018 | gcc_assert (bbs[0] == loop->header); | |
1019 | gcc_assert (bbs[n - 1] == loop->latch); | |
617b465c ZD |
1020 | |
1021 | /* Check whether duplication is possible. */ | |
8d28e87d | 1022 | if (!can_copy_bbs_p (bbs, loop->num_nodes)) |
617b465c | 1023 | { |
8d28e87d ZD |
1024 | free (bbs); |
1025 | return false; | |
617b465c | 1026 | } |
5ed6ace5 | 1027 | new_bbs = XNEWVEC (basic_block, loop->num_nodes); |
617b465c | 1028 | |
8d28e87d ZD |
1029 | /* In case we are doing loop peeling and the loop is in the middle of |
1030 | irreducible region, the peeled copies will be inside it too. */ | |
1031 | add_irreducible_flag = e->flags & EDGE_IRREDUCIBLE_LOOP; | |
341c100f | 1032 | gcc_assert (!is_latch || !add_irreducible_flag); |
617b465c ZD |
1033 | |
1034 | /* Find edge from latch. */ | |
1035 | latch_edge = loop_latch_edge (loop); | |
1036 | ||
1037 | if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
1038 | { | |
1039 | /* Calculate coefficients by that we have to scale frequencies | |
1040 | of duplicated loop bodies. */ | |
1041 | freq_in = header->frequency; | |
1042 | freq_le = EDGE_FREQUENCY (latch_edge); | |
1043 | if (freq_in == 0) | |
1044 | freq_in = 1; | |
1045 | if (freq_in < freq_le) | |
1046 | freq_in = freq_le; | |
1047 | freq_out_orig = orig ? EDGE_FREQUENCY (orig) : freq_in - freq_le; | |
1048 | if (freq_out_orig > freq_in - freq_le) | |
1049 | freq_out_orig = freq_in - freq_le; | |
1050 | prob_pass_thru = RDIV (REG_BR_PROB_BASE * freq_le, freq_in); | |
1051 | prob_pass_wont_exit = | |
1052 | RDIV (REG_BR_PROB_BASE * (freq_le + freq_out_orig), freq_in); | |
1053 | ||
03cb2019 ZD |
1054 | if (orig |
1055 | && REG_BR_PROB_BASE - orig->probability != 0) | |
1056 | { | |
1057 | /* The blocks that are dominated by a removed exit edge ORIG have | |
1058 | frequencies scaled by this. */ | |
1059 | scale_after_exit = RDIV (REG_BR_PROB_BASE * REG_BR_PROB_BASE, | |
1060 | REG_BR_PROB_BASE - orig->probability); | |
1061 | bbs_to_scale = BITMAP_ALLOC (NULL); | |
1062 | for (i = 0; i < n; i++) | |
1063 | { | |
1064 | if (bbs[i] != orig->src | |
1065 | && dominated_by_p (CDI_DOMINATORS, bbs[i], orig->src)) | |
1066 | bitmap_set_bit (bbs_to_scale, i); | |
1067 | } | |
1068 | } | |
1069 | ||
5ed6ace5 | 1070 | scale_step = XNEWVEC (int, ndupl); |
617b465c | 1071 | |
03cb2019 ZD |
1072 | for (i = 1; i <= ndupl; i++) |
1073 | scale_step[i - 1] = TEST_BIT (wont_exit, i) | |
617b465c ZD |
1074 | ? prob_pass_wont_exit |
1075 | : prob_pass_thru; | |
1076 | ||
a4d05547 | 1077 | /* Complete peeling is special as the probability of exit in last |
c22cacf3 | 1078 | copy becomes 1. */ |
178df94f JH |
1079 | if (flags & DLTHE_FLAG_COMPLETTE_PEEL) |
1080 | { | |
1081 | int wanted_freq = EDGE_FREQUENCY (e); | |
1082 | ||
1083 | if (wanted_freq > freq_in) | |
1084 | wanted_freq = freq_in; | |
1085 | ||
1086 | gcc_assert (!is_latch); | |
a4d05547 | 1087 | /* First copy has frequency of incoming edge. Each subsequent |
178df94f JH |
1088 | frequency should be reduced by prob_pass_wont_exit. Caller |
1089 | should've managed the flags so all except for original loop | |
1090 | has won't exist set. */ | |
1091 | scale_act = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in); | |
1092 | /* Now simulate the duplication adjustments and compute header | |
1093 | frequency of the last copy. */ | |
1094 | for (i = 0; i < ndupl; i++) | |
c22cacf3 | 1095 | wanted_freq = RDIV (wanted_freq * scale_step[i], REG_BR_PROB_BASE); |
178df94f JH |
1096 | scale_main = RDIV (wanted_freq * REG_BR_PROB_BASE, freq_in); |
1097 | } | |
1098 | else if (is_latch) | |
617b465c ZD |
1099 | { |
1100 | prob_pass_main = TEST_BIT (wont_exit, 0) | |
1101 | ? prob_pass_wont_exit | |
1102 | : prob_pass_thru; | |
1103 | p = prob_pass_main; | |
1104 | scale_main = REG_BR_PROB_BASE; | |
1105 | for (i = 0; i < ndupl; i++) | |
1106 | { | |
1107 | scale_main += p; | |
1108 | p = RDIV (p * scale_step[i], REG_BR_PROB_BASE); | |
1109 | } | |
1110 | scale_main = RDIV (REG_BR_PROB_BASE * REG_BR_PROB_BASE, scale_main); | |
1111 | scale_act = RDIV (scale_main * prob_pass_main, REG_BR_PROB_BASE); | |
1112 | } | |
1113 | else | |
1114 | { | |
1115 | scale_main = REG_BR_PROB_BASE; | |
1116 | for (i = 0; i < ndupl; i++) | |
1117 | scale_main = RDIV (scale_main * scale_step[i], REG_BR_PROB_BASE); | |
1118 | scale_act = REG_BR_PROB_BASE - prob_pass_thru; | |
1119 | } | |
1120 | for (i = 0; i < ndupl; i++) | |
341c100f NS |
1121 | gcc_assert (scale_step[i] >= 0 && scale_step[i] <= REG_BR_PROB_BASE); |
1122 | gcc_assert (scale_main >= 0 && scale_main <= REG_BR_PROB_BASE | |
1123 | && scale_act >= 0 && scale_act <= REG_BR_PROB_BASE); | |
617b465c ZD |
1124 | } |
1125 | ||
1126 | /* Loop the new bbs will belong to. */ | |
8d28e87d | 1127 | target = e->src->loop_father; |
617b465c ZD |
1128 | |
1129 | /* Original loops. */ | |
1130 | n_orig_loops = 0; | |
1131 | for (aloop = loop->inner; aloop; aloop = aloop->next) | |
1132 | n_orig_loops++; | |
5ed6ace5 | 1133 | orig_loops = XCNEWVEC (struct loop *, n_orig_loops); |
617b465c ZD |
1134 | for (aloop = loop->inner, i = 0; aloop; aloop = aloop->next, i++) |
1135 | orig_loops[i] = aloop; | |
1136 | ||
561e8a90 | 1137 | set_loop_copy (loop, target); |
d329e058 | 1138 | |
5ed6ace5 | 1139 | first_active = XNEWVEC (basic_block, n); |
617b465c ZD |
1140 | if (is_latch) |
1141 | { | |
1142 | memcpy (first_active, bbs, n * sizeof (basic_block)); | |
1143 | first_active_latch = latch; | |
1144 | } | |
1145 | ||
8d28e87d ZD |
1146 | spec_edges[SE_ORIG] = orig; |
1147 | spec_edges[SE_LATCH] = latch_edge; | |
d329e058 | 1148 | |
b9a66240 | 1149 | place_after = e->src; |
617b465c ZD |
1150 | for (j = 0; j < ndupl; j++) |
1151 | { | |
1152 | /* Copy loops. */ | |
d73be268 | 1153 | copy_loops_to (orig_loops, n_orig_loops, target); |
617b465c ZD |
1154 | |
1155 | /* Copy bbs. */ | |
b9a66240 ZD |
1156 | copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop, |
1157 | place_after); | |
1158 | place_after = new_spec_edges[SE_LATCH]->src; | |
8d28e87d | 1159 | |
7f7b1718 JH |
1160 | if (flags & DLTHE_RECORD_COPY_NUMBER) |
1161 | for (i = 0; i < n; i++) | |
1162 | { | |
1163 | gcc_assert (!new_bbs[i]->aux); | |
1164 | new_bbs[i]->aux = (void *)(size_t)(j + 1); | |
1165 | } | |
113d659a | 1166 | |
84d45ad1 ZD |
1167 | /* Note whether the blocks and edges belong to an irreducible loop. */ |
1168 | if (add_irreducible_flag) | |
1169 | { | |
1170 | for (i = 0; i < n; i++) | |
6580ee77 | 1171 | new_bbs[i]->flags |= BB_DUPLICATED; |
84d45ad1 ZD |
1172 | for (i = 0; i < n; i++) |
1173 | { | |
628f6a4e | 1174 | edge_iterator ei; |
84d45ad1 ZD |
1175 | new_bb = new_bbs[i]; |
1176 | if (new_bb->loop_father == target) | |
1177 | new_bb->flags |= BB_IRREDUCIBLE_LOOP; | |
1178 | ||
628f6a4e | 1179 | FOR_EACH_EDGE (ae, ei, new_bb->succs) |
6580ee77 | 1180 | if ((ae->dest->flags & BB_DUPLICATED) |
84d45ad1 ZD |
1181 | && (ae->src->loop_father == target |
1182 | || ae->dest->loop_father == target)) | |
1183 | ae->flags |= EDGE_IRREDUCIBLE_LOOP; | |
1184 | } | |
1185 | for (i = 0; i < n; i++) | |
6580ee77 | 1186 | new_bbs[i]->flags &= ~BB_DUPLICATED; |
84d45ad1 ZD |
1187 | } |
1188 | ||
8d28e87d | 1189 | /* Redirect the special edges. */ |
617b465c | 1190 | if (is_latch) |
8d28e87d ZD |
1191 | { |
1192 | redirect_edge_and_branch_force (latch_edge, new_bbs[0]); | |
1193 | redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
1194 | loop->header); | |
d47cc544 | 1195 | set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], latch); |
b9a66240 | 1196 | latch = loop->latch = new_bbs[n - 1]; |
8d28e87d ZD |
1197 | e = latch_edge = new_spec_edges[SE_LATCH]; |
1198 | } | |
1199 | else | |
1200 | { | |
1201 | redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
1202 | loop->header); | |
1203 | redirect_edge_and_branch_force (e, new_bbs[0]); | |
d47cc544 | 1204 | set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], e->src); |
8d28e87d ZD |
1205 | e = new_spec_edges[SE_LATCH]; |
1206 | } | |
617b465c | 1207 | |
8d28e87d ZD |
1208 | /* Record exit edge in this copy. */ |
1209 | if (orig && TEST_BIT (wont_exit, j + 1)) | |
ee8c1b05 ZD |
1210 | { |
1211 | if (to_remove) | |
1212 | VEC_safe_push (edge, heap, *to_remove, new_spec_edges[SE_ORIG]); | |
03cb2019 ZD |
1213 | set_zero_probability (new_spec_edges[SE_ORIG]); |
1214 | ||
1215 | /* Scale the frequencies of the blocks dominated by the exit. */ | |
1216 | if (bbs_to_scale) | |
1217 | { | |
1218 | EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
1219 | { | |
1220 | scale_bbs_frequencies_int (new_bbs + i, 1, scale_after_exit, | |
1221 | REG_BR_PROB_BASE); | |
1222 | } | |
1223 | } | |
ee8c1b05 | 1224 | } |
d329e058 | 1225 | |
8d28e87d ZD |
1226 | /* Record the first copy in the control flow order if it is not |
1227 | the original loop (i.e. in case of peeling). */ | |
617b465c ZD |
1228 | if (!first_active_latch) |
1229 | { | |
1230 | memcpy (first_active, new_bbs, n * sizeof (basic_block)); | |
b9a66240 | 1231 | first_active_latch = new_bbs[n - 1]; |
617b465c | 1232 | } |
d329e058 | 1233 | |
8d28e87d ZD |
1234 | /* Set counts and frequencies. */ |
1235 | if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
617b465c | 1236 | { |
33156717 | 1237 | scale_bbs_frequencies_int (new_bbs, n, scale_act, REG_BR_PROB_BASE); |
8d28e87d | 1238 | scale_act = RDIV (scale_act * scale_step[j], REG_BR_PROB_BASE); |
617b465c ZD |
1239 | } |
1240 | } | |
8d28e87d ZD |
1241 | free (new_bbs); |
1242 | free (orig_loops); | |
c22cacf3 | 1243 | |
ee8c1b05 ZD |
1244 | /* Record the exit edge in the original loop body, and update the frequencies. */ |
1245 | if (orig && TEST_BIT (wont_exit, 0)) | |
1246 | { | |
1247 | if (to_remove) | |
1248 | VEC_safe_push (edge, heap, *to_remove, orig); | |
03cb2019 ZD |
1249 | set_zero_probability (orig); |
1250 | ||
1251 | /* Scale the frequencies of the blocks dominated by the exit. */ | |
1252 | if (bbs_to_scale) | |
1253 | { | |
1254 | EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
1255 | { | |
1256 | scale_bbs_frequencies_int (bbs + i, 1, scale_after_exit, | |
1257 | REG_BR_PROB_BASE); | |
1258 | } | |
1259 | } | |
ee8c1b05 ZD |
1260 | } |
1261 | ||
8d28e87d ZD |
1262 | /* Update the original loop. */ |
1263 | if (!is_latch) | |
d47cc544 | 1264 | set_immediate_dominator (CDI_DOMINATORS, e->dest, e->src); |
617b465c ZD |
1265 | if (flags & DLTHE_FLAG_UPDATE_FREQ) |
1266 | { | |
33156717 | 1267 | scale_bbs_frequencies_int (bbs, n, scale_main, REG_BR_PROB_BASE); |
617b465c ZD |
1268 | free (scale_step); |
1269 | } | |
617b465c | 1270 | |
8d28e87d | 1271 | /* Update dominators of outer blocks if affected. */ |
617b465c ZD |
1272 | for (i = 0; i < n; i++) |
1273 | { | |
66f97d31 ZD |
1274 | basic_block dominated, dom_bb; |
1275 | VEC (basic_block, heap) *dom_bbs; | |
1276 | unsigned j; | |
617b465c ZD |
1277 | |
1278 | bb = bbs[i]; | |
6580ee77 | 1279 | bb->aux = 0; |
113d659a | 1280 | |
66f97d31 ZD |
1281 | dom_bbs = get_dominated_by (CDI_DOMINATORS, bb); |
1282 | for (j = 0; VEC_iterate (basic_block, dom_bbs, j, dominated); j++) | |
617b465c | 1283 | { |
617b465c ZD |
1284 | if (flow_bb_inside_loop_p (loop, dominated)) |
1285 | continue; | |
1286 | dom_bb = nearest_common_dominator ( | |
d47cc544 | 1287 | CDI_DOMINATORS, first_active[i], first_active_latch); |
c22cacf3 | 1288 | set_immediate_dominator (CDI_DOMINATORS, dominated, dom_bb); |
617b465c | 1289 | } |
66f97d31 | 1290 | VEC_free (basic_block, heap, dom_bbs); |
617b465c ZD |
1291 | } |
1292 | free (first_active); | |
1293 | ||
1294 | free (bbs); | |
03cb2019 | 1295 | BITMAP_FREE (bbs_to_scale); |
617b465c ZD |
1296 | |
1297 | return true; | |
1298 | } | |
1299 | ||
f470c378 ZD |
1300 | /* A callback for make_forwarder block, to redirect all edges except for |
1301 | MFB_KJ_EDGE to the entry part. E is the edge for that we should decide | |
1302 | whether to redirect it. */ | |
1303 | ||
b02b9b53 ZD |
1304 | edge mfb_kj_edge; |
1305 | bool | |
f470c378 ZD |
1306 | mfb_keep_just (edge e) |
1307 | { | |
1308 | return e != mfb_kj_edge; | |
1309 | } | |
1310 | ||
e855c69d AB |
1311 | /* True when a candidate preheader BLOCK has predecessors from LOOP. */ |
1312 | ||
1313 | static bool | |
1314 | has_preds_from_loop (basic_block block, struct loop *loop) | |
1315 | { | |
1316 | edge e; | |
1317 | edge_iterator ei; | |
1318 | ||
1319 | FOR_EACH_EDGE (e, ei, block->preds) | |
1320 | if (e->src->loop_father == loop) | |
1321 | return true; | |
1322 | return false; | |
1323 | } | |
1324 | ||
3d436d2a ZD |
1325 | /* Creates a pre-header for a LOOP. Returns newly created block. Unless |
1326 | CP_SIMPLE_PREHEADERS is set in FLAGS, we only force LOOP to have single | |
1327 | entry; otherwise we also force preheader block to have only one successor. | |
e855c69d AB |
1328 | When CP_FALLTHRU_PREHEADERS is set in FLAGS, we force the preheader block |
1329 | to be a fallthru predecessor to the loop header and to have only | |
1330 | predecessors from outside of the loop. | |
f470c378 ZD |
1331 | The function also updates dominators. */ |
1332 | ||
b02b9b53 | 1333 | basic_block |
d47cc544 | 1334 | create_preheader (struct loop *loop, int flags) |
3d436d2a ZD |
1335 | { |
1336 | edge e, fallthru; | |
1337 | basic_block dummy; | |
3d436d2a | 1338 | int nentry = 0; |
f470c378 | 1339 | bool irred = false; |
c15bc84b | 1340 | bool latch_edge_was_fallthru; |
c7b852c8 | 1341 | edge one_succ_pred = NULL, single_entry = NULL; |
628f6a4e | 1342 | edge_iterator ei; |
3d436d2a | 1343 | |
628f6a4e | 1344 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
3d436d2a ZD |
1345 | { |
1346 | if (e->src == loop->latch) | |
1347 | continue; | |
f470c378 | 1348 | irred |= (e->flags & EDGE_IRREDUCIBLE_LOOP) != 0; |
3d436d2a | 1349 | nentry++; |
c7b852c8 | 1350 | single_entry = e; |
c5cbcccf | 1351 | if (single_succ_p (e->src)) |
c15bc84b | 1352 | one_succ_pred = e; |
3d436d2a | 1353 | } |
341c100f | 1354 | gcc_assert (nentry); |
3d436d2a ZD |
1355 | if (nentry == 1) |
1356 | { | |
e855c69d AB |
1357 | bool need_forwarder_block = false; |
1358 | ||
1359 | /* We do not allow entry block to be the loop preheader, since we | |
89f8f30f | 1360 | cannot emit code there. */ |
e855c69d AB |
1361 | if (single_entry->src == ENTRY_BLOCK_PTR) |
1362 | need_forwarder_block = true; | |
1363 | else | |
1364 | { | |
1365 | /* If we want simple preheaders, also force the preheader to have | |
1366 | just a single successor. */ | |
1367 | if ((flags & CP_SIMPLE_PREHEADERS) | |
1368 | && !single_succ_p (single_entry->src)) | |
1369 | need_forwarder_block = true; | |
1370 | /* If we want fallthru preheaders, also create forwarder block when | |
1371 | preheader ends with a jump or has predecessors from loop. */ | |
1372 | else if ((flags & CP_FALLTHRU_PREHEADERS) | |
1373 | && (JUMP_P (BB_END (single_entry->src)) | |
1374 | || has_preds_from_loop (single_entry->src, loop))) | |
1375 | need_forwarder_block = true; | |
1376 | } | |
1377 | if (! need_forwarder_block) | |
3d436d2a ZD |
1378 | return NULL; |
1379 | } | |
1380 | ||
f470c378 | 1381 | mfb_kj_edge = loop_latch_edge (loop); |
c15bc84b | 1382 | latch_edge_was_fallthru = (mfb_kj_edge->flags & EDGE_FALLTHRU) != 0; |
598ec7bd | 1383 | fallthru = make_forwarder_block (loop->header, mfb_keep_just, NULL); |
3d436d2a ZD |
1384 | dummy = fallthru->src; |
1385 | loop->header = fallthru->dest; | |
1386 | ||
c15bc84b EB |
1387 | /* Try to be clever in placing the newly created preheader. The idea is to |
1388 | avoid breaking any "fallthruness" relationship between blocks. | |
1389 | ||
1390 | The preheader was created just before the header and all incoming edges | |
1391 | to the header were redirected to the preheader, except the latch edge. | |
1392 | So the only problematic case is when this latch edge was a fallthru | |
1393 | edge: it is not anymore after the preheader creation so we have broken | |
1394 | the fallthruness. We're therefore going to look for a better place. */ | |
1395 | if (latch_edge_was_fallthru) | |
1396 | { | |
1397 | if (one_succ_pred) | |
1398 | e = one_succ_pred; | |
1399 | else | |
1400 | e = EDGE_PRED (dummy, 0); | |
1401 | ||
1402 | move_block_after (dummy, e->src); | |
1403 | } | |
f470c378 | 1404 | |
f470c378 | 1405 | if (irred) |
3d436d2a | 1406 | { |
f470c378 | 1407 | dummy->flags |= BB_IRREDUCIBLE_LOOP; |
c5cbcccf | 1408 | single_succ_edge (dummy)->flags |= EDGE_IRREDUCIBLE_LOOP; |
3d436d2a ZD |
1409 | } |
1410 | ||
c263766c RH |
1411 | if (dump_file) |
1412 | fprintf (dump_file, "Created preheader block for loop %i\n", | |
3d436d2a | 1413 | loop->num); |
e855c69d AB |
1414 | |
1415 | if (flags & CP_FALLTHRU_PREHEADERS) | |
1416 | gcc_assert ((single_succ_edge (dummy)->flags & EDGE_FALLTHRU) | |
1417 | && !JUMP_P (BB_END (dummy))); | |
3d436d2a ZD |
1418 | |
1419 | return dummy; | |
1420 | } | |
1421 | ||
d73be268 ZD |
1422 | /* Create preheaders for each loop; for meaning of FLAGS see create_preheader. */ |
1423 | ||
3d436d2a | 1424 | void |
d73be268 | 1425 | create_preheaders (int flags) |
3d436d2a | 1426 | { |
42fd6772 ZD |
1427 | loop_iterator li; |
1428 | struct loop *loop; | |
1429 | ||
c7b852c8 ZD |
1430 | if (!current_loops) |
1431 | return; | |
1432 | ||
42fd6772 ZD |
1433 | FOR_EACH_LOOP (li, loop, 0) |
1434 | create_preheader (loop, flags); | |
f87000d0 | 1435 | loops_state_set (LOOPS_HAVE_PREHEADERS); |
3d436d2a ZD |
1436 | } |
1437 | ||
d73be268 ZD |
1438 | /* Forces all loop latches to have only single successor. */ |
1439 | ||
3d436d2a | 1440 | void |
d73be268 | 1441 | force_single_succ_latches (void) |
3d436d2a | 1442 | { |
42fd6772 | 1443 | loop_iterator li; |
3d436d2a ZD |
1444 | struct loop *loop; |
1445 | edge e; | |
1446 | ||
42fd6772 | 1447 | FOR_EACH_LOOP (li, loop, 0) |
3d436d2a | 1448 | { |
c5cbcccf | 1449 | if (loop->latch != loop->header && single_succ_p (loop->latch)) |
3d436d2a | 1450 | continue; |
d329e058 | 1451 | |
9ff3d2de | 1452 | e = find_edge (loop->latch, loop->header); |
bc810602 | 1453 | |
598ec7bd | 1454 | split_edge (e); |
3d436d2a | 1455 | } |
f87000d0 | 1456 | loops_state_set (LOOPS_HAVE_SIMPLE_LATCHES); |
3d436d2a ZD |
1457 | } |
1458 | ||
1cb7dfc3 MH |
1459 | /* This function is called from loop_version. It splits the entry edge |
1460 | of the loop we want to version, adds the versioning condition, and | |
1461 | adjust the edges to the two versions of the loop appropriately. | |
1462 | e is an incoming edge. Returns the basic block containing the | |
1463 | condition. | |
1464 | ||
1465 | --- edge e ---- > [second_head] | |
1466 | ||
1467 | Split it and insert new conditional expression and adjust edges. | |
1468 | ||
1469 | --- edge e ---> [cond expr] ---> [first_head] | |
c22cacf3 MS |
1470 | | |
1471 | +---------> [second_head] | |
03cb2019 ZD |
1472 | |
1473 | THEN_PROB is the probability of then branch of the condition. */ | |
1cb7dfc3 MH |
1474 | |
1475 | static basic_block | |
03cb2019 ZD |
1476 | lv_adjust_loop_entry_edge (basic_block first_head, basic_block second_head, |
1477 | edge e, void *cond_expr, unsigned then_prob) | |
1cb7dfc3 MH |
1478 | { |
1479 | basic_block new_head = NULL; | |
1480 | edge e1; | |
1481 | ||
1482 | gcc_assert (e->dest == second_head); | |
1483 | ||
1484 | /* Split edge 'e'. This will create a new basic block, where we can | |
1485 | insert conditional expr. */ | |
1486 | new_head = split_edge (e); | |
1487 | ||
1cb7dfc3 MH |
1488 | lv_add_condition_to_bb (first_head, second_head, new_head, |
1489 | cond_expr); | |
1490 | ||
766613a4 | 1491 | /* Don't set EDGE_TRUE_VALUE in RTL mode, as it's invalid there. */ |
03cb2019 | 1492 | e = single_succ_edge (new_head); |
52bca999 SB |
1493 | e1 = make_edge (new_head, first_head, |
1494 | current_ir_type () == IR_GIMPLE ? EDGE_TRUE_VALUE : 0); | |
03cb2019 ZD |
1495 | e1->probability = then_prob; |
1496 | e->probability = REG_BR_PROB_BASE - then_prob; | |
1497 | e1->count = RDIV (e->count * e1->probability, REG_BR_PROB_BASE); | |
1498 | e->count = RDIV (e->count * e->probability, REG_BR_PROB_BASE); | |
1499 | ||
1cb7dfc3 MH |
1500 | set_immediate_dominator (CDI_DOMINATORS, first_head, new_head); |
1501 | set_immediate_dominator (CDI_DOMINATORS, second_head, new_head); | |
1502 | ||
1503 | /* Adjust loop header phi nodes. */ | |
1504 | lv_adjust_loop_header_phi (first_head, second_head, new_head, e1); | |
1505 | ||
1506 | return new_head; | |
1507 | } | |
1508 | ||
1509 | /* Main entry point for Loop Versioning transformation. | |
c22cacf3 | 1510 | |
b9a66240 ZD |
1511 | This transformation given a condition and a loop, creates |
1512 | -if (condition) { loop_copy1 } else { loop_copy2 }, | |
1513 | where loop_copy1 is the loop transformed in one way, and loop_copy2 | |
1514 | is the loop transformed in another way (or unchanged). 'condition' | |
1515 | may be a run time test for things that were not resolved by static | |
1516 | analysis (overlapping ranges (anti-aliasing), alignment, etc.). | |
1517 | ||
03cb2019 ZD |
1518 | THEN_PROB is the probability of the then edge of the if. THEN_SCALE |
1519 | is the ratio by that the frequencies in the original loop should | |
1520 | be scaled. ELSE_SCALE is the ratio by that the frequencies in the | |
1521 | new loop should be scaled. | |
1522 | ||
b9a66240 ZD |
1523 | If PLACE_AFTER is true, we place the new loop after LOOP in the |
1524 | instruction stream, otherwise it is placed before LOOP. */ | |
1cb7dfc3 MH |
1525 | |
1526 | struct loop * | |
d73be268 | 1527 | loop_version (struct loop *loop, |
b9a66240 | 1528 | void *cond_expr, basic_block *condition_bb, |
03cb2019 | 1529 | unsigned then_prob, unsigned then_scale, unsigned else_scale, |
b9a66240 | 1530 | bool place_after) |
1cb7dfc3 MH |
1531 | { |
1532 | basic_block first_head, second_head; | |
6270df4c | 1533 | edge entry, latch_edge, true_edge, false_edge; |
1cb7dfc3 MH |
1534 | int irred_flag; |
1535 | struct loop *nloop; | |
b9a66240 | 1536 | basic_block cond_bb; |
1cb7dfc3 | 1537 | |
1cb7dfc3 MH |
1538 | /* Record entry and latch edges for the loop */ |
1539 | entry = loop_preheader_edge (loop); | |
1540 | irred_flag = entry->flags & EDGE_IRREDUCIBLE_LOOP; | |
1541 | entry->flags &= ~EDGE_IRREDUCIBLE_LOOP; | |
c22cacf3 | 1542 | |
1cb7dfc3 MH |
1543 | /* Note down head of loop as first_head. */ |
1544 | first_head = entry->dest; | |
1545 | ||
1546 | /* Duplicate loop. */ | |
d73be268 | 1547 | if (!cfg_hook_duplicate_loop_to_header_edge (loop, entry, 1, |
ee8c1b05 | 1548 | NULL, NULL, NULL, 0)) |
1cb7dfc3 MH |
1549 | return NULL; |
1550 | ||
1551 | /* After duplication entry edge now points to new loop head block. | |
1552 | Note down new head as second_head. */ | |
1553 | second_head = entry->dest; | |
1554 | ||
1555 | /* Split loop entry edge and insert new block with cond expr. */ | |
b9a66240 | 1556 | cond_bb = lv_adjust_loop_entry_edge (first_head, second_head, |
03cb2019 | 1557 | entry, cond_expr, then_prob); |
b9a66240 ZD |
1558 | if (condition_bb) |
1559 | *condition_bb = cond_bb; | |
1560 | ||
1561 | if (!cond_bb) | |
1cb7dfc3 MH |
1562 | { |
1563 | entry->flags |= irred_flag; | |
1564 | return NULL; | |
1565 | } | |
1566 | ||
6580ee77 | 1567 | latch_edge = single_succ_edge (get_bb_copy (loop->latch)); |
c22cacf3 | 1568 | |
b9a66240 | 1569 | extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); |
d73be268 | 1570 | nloop = loopify (latch_edge, |
6580ee77 | 1571 | single_pred_edge (get_bb_copy (loop->header)), |
b9a66240 | 1572 | cond_bb, true_edge, false_edge, |
03cb2019 ZD |
1573 | false /* Do not redirect all edges. */, |
1574 | then_scale, else_scale); | |
1cb7dfc3 | 1575 | |
c22cacf3 | 1576 | /* loopify redirected latch_edge. Update its PENDING_STMTS. */ |
1cb7dfc3 MH |
1577 | lv_flush_pending_stmts (latch_edge); |
1578 | ||
c22cacf3 | 1579 | /* loopify redirected condition_bb's succ edge. Update its PENDING_STMTS. */ |
b9a66240 | 1580 | extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); |
1cb7dfc3 MH |
1581 | lv_flush_pending_stmts (false_edge); |
1582 | /* Adjust irreducible flag. */ | |
1583 | if (irred_flag) | |
1584 | { | |
b9a66240 | 1585 | cond_bb->flags |= BB_IRREDUCIBLE_LOOP; |
1cb7dfc3 MH |
1586 | loop_preheader_edge (loop)->flags |= EDGE_IRREDUCIBLE_LOOP; |
1587 | loop_preheader_edge (nloop)->flags |= EDGE_IRREDUCIBLE_LOOP; | |
b9a66240 ZD |
1588 | single_pred_edge (cond_bb)->flags |= EDGE_IRREDUCIBLE_LOOP; |
1589 | } | |
1590 | ||
1591 | if (place_after) | |
1592 | { | |
1593 | basic_block *bbs = get_loop_body_in_dom_order (nloop), after; | |
1594 | unsigned i; | |
1595 | ||
1596 | after = loop->latch; | |
1597 | ||
1598 | for (i = 0; i < nloop->num_nodes; i++) | |
1599 | { | |
1600 | move_block_after (bbs[i], after); | |
1601 | after = bbs[i]; | |
1602 | } | |
1603 | free (bbs); | |
1cb7dfc3 MH |
1604 | } |
1605 | ||
fa10beec RW |
1606 | /* At this point condition_bb is loop preheader with two successors, |
1607 | first_head and second_head. Make sure that loop preheader has only | |
1cb7dfc3 | 1608 | one successor. */ |
598ec7bd ZD |
1609 | split_edge (loop_preheader_edge (loop)); |
1610 | split_edge (loop_preheader_edge (nloop)); | |
1cb7dfc3 MH |
1611 | |
1612 | return nloop; | |
1613 | } | |
1614 | ||
d73be268 | 1615 | /* The structure of loops might have changed. Some loops might get removed |
2b271002 ZD |
1616 | (and their headers and latches were set to NULL), loop exists might get |
1617 | removed (thus the loop nesting may be wrong), and some blocks and edges | |
1618 | were changed (so the information about bb --> loop mapping does not have | |
1619 | to be correct). But still for the remaining loops the header dominates | |
fa10beec | 1620 | the latch, and loops did not get new subloops (new loops might possibly |
2b271002 | 1621 | get created, but we are not interested in them). Fix up the mess. |
c22cacf3 | 1622 | |
2b271002 ZD |
1623 | If CHANGED_BBS is not NULL, basic blocks whose loop has changed are |
1624 | marked in it. */ | |
1625 | ||
1626 | void | |
d73be268 | 1627 | fix_loop_structure (bitmap changed_bbs) |
2b271002 ZD |
1628 | { |
1629 | basic_block bb; | |
1630 | struct loop *loop, *ploop; | |
42fd6772 | 1631 | loop_iterator li; |
c7b852c8 ZD |
1632 | bool record_exits = false; |
1633 | struct loop **superloop = XNEWVEC (struct loop *, number_of_loops ()); | |
2b271002 | 1634 | |
c7b852c8 ZD |
1635 | /* Remove the old bb -> loop mapping. Remember the depth of the blocks in |
1636 | the loop hierarchy, so that we can recognize blocks whose loop nesting | |
1637 | relationship has changed. */ | |
2b271002 ZD |
1638 | FOR_EACH_BB (bb) |
1639 | { | |
c7b852c8 | 1640 | if (changed_bbs) |
9ba025a2 | 1641 | bb->aux = (void *) (size_t) loop_depth (bb->loop_father); |
d73be268 | 1642 | bb->loop_father = current_loops->tree_root; |
2b271002 ZD |
1643 | } |
1644 | ||
f87000d0 | 1645 | if (loops_state_satisfies_p (LOOPS_HAVE_RECORDED_EXITS)) |
c7b852c8 ZD |
1646 | { |
1647 | release_recorded_exits (); | |
1648 | record_exits = true; | |
1649 | } | |
1650 | ||
1651 | /* Remove the dead loops from structures. We start from the innermost | |
1652 | loops, so that when we remove the loops, we know that the loops inside | |
1653 | are preserved, and do not waste time relinking loops that will be | |
1654 | removed later. */ | |
1655 | FOR_EACH_LOOP (li, loop, LI_FROM_INNERMOST) | |
2b271002 | 1656 | { |
2b271002 ZD |
1657 | if (loop->header) |
1658 | continue; | |
1659 | ||
1660 | while (loop->inner) | |
1661 | { | |
1662 | ploop = loop->inner; | |
1663 | flow_loop_tree_node_remove (ploop); | |
9ba025a2 | 1664 | flow_loop_tree_node_add (loop_outer (loop), ploop); |
2b271002 ZD |
1665 | } |
1666 | ||
1667 | /* Remove the loop and free its data. */ | |
42fd6772 | 1668 | delete_loop (loop); |
2b271002 ZD |
1669 | } |
1670 | ||
c7b852c8 ZD |
1671 | /* Rescan the bodies of loops, starting from the outermost ones. We assume |
1672 | that no optimization interchanges the order of the loops, i.e., it cannot | |
1673 | happen that L1 was superloop of L2 before and it is subloop of L2 now | |
1674 | (without explicitly updating loop information). At the same time, we also | |
1675 | determine the new loop structure. */ | |
1676 | current_loops->tree_root->num_nodes = n_basic_blocks; | |
42fd6772 | 1677 | FOR_EACH_LOOP (li, loop, 0) |
2b271002 | 1678 | { |
c7b852c8 | 1679 | superloop[loop->num] = loop->header->loop_father; |
2b271002 ZD |
1680 | loop->num_nodes = flow_loop_nodes_find (loop->header, loop); |
1681 | } | |
1682 | ||
1683 | /* Now fix the loop nesting. */ | |
42fd6772 | 1684 | FOR_EACH_LOOP (li, loop, 0) |
2b271002 | 1685 | { |
c7b852c8 | 1686 | ploop = superloop[loop->num]; |
9ba025a2 | 1687 | if (ploop != loop_outer (loop)) |
2b271002 ZD |
1688 | { |
1689 | flow_loop_tree_node_remove (loop); | |
c7b852c8 | 1690 | flow_loop_tree_node_add (ploop, loop); |
2b271002 ZD |
1691 | } |
1692 | } | |
c7b852c8 | 1693 | free (superloop); |
2b271002 ZD |
1694 | |
1695 | /* Mark the blocks whose loop has changed. */ | |
c7b852c8 | 1696 | if (changed_bbs) |
2b271002 | 1697 | { |
c7b852c8 ZD |
1698 | FOR_EACH_BB (bb) |
1699 | { | |
9ba025a2 | 1700 | if ((void *) (size_t) loop_depth (bb->loop_father) != bb->aux) |
c7b852c8 | 1701 | bitmap_set_bit (changed_bbs, bb->index); |
2b271002 | 1702 | |
c7b852c8 ZD |
1703 | bb->aux = NULL; |
1704 | } | |
2b271002 ZD |
1705 | } |
1706 | ||
f87000d0 | 1707 | if (loops_state_satisfies_p (LOOPS_HAVE_PREHEADERS)) |
c7b852c8 ZD |
1708 | create_preheaders (CP_SIMPLE_PREHEADERS); |
1709 | ||
f87000d0 | 1710 | if (loops_state_satisfies_p (LOOPS_HAVE_SIMPLE_LATCHES)) |
af0b10e5 ZD |
1711 | force_single_succ_latches (); |
1712 | ||
f87000d0 | 1713 | if (loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
d73be268 | 1714 | mark_irreducible_loops (); |
6270df4c | 1715 | |
c7b852c8 ZD |
1716 | if (record_exits) |
1717 | record_loop_exits (); | |
1718 | ||
1719 | #ifdef ENABLE_CHECKING | |
1720 | verify_loop_structure (); | |
1721 | #endif | |
2b271002 | 1722 | } |