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862be747 | 1 | /* Loop manipulation code for GNU compiler. |
aad93da1 | 2 | Copyright (C) 2002-2017 Free Software Foundation, Inc. |
862be747 | 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 | |
8c4c00c1 | 8 | Software Foundation; either version 3, or (at your option) any later |
862be747 | 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 | |
8c4c00c1 | 17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
862be747 | 19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
9ef16211 | 23 | #include "backend.h" |
7c29e30e | 24 | #include "rtl.h" |
9ef16211 | 25 | #include "tree.h" |
26 | #include "gimple.h" | |
7c29e30e | 27 | #include "cfghooks.h" |
94ea8568 | 28 | #include "cfganal.h" |
862be747 | 29 | #include "cfgloop.h" |
dcf1a1ec | 30 | #include "gimple-iterator.h" |
e795d6e1 | 31 | #include "gimplify-me.h" |
05d9c18a | 32 | #include "tree-ssa-loop-manip.h" |
b9ed1410 | 33 | #include "dumpfile.h" |
862be747 | 34 | |
7194de72 | 35 | static void copy_loops_to (struct loop **, int, |
4c9e08a4 | 36 | struct loop *); |
37 | static void loop_redirect_edge (edge, basic_block); | |
0051c76a | 38 | static void remove_bbs (basic_block *, int); |
7ecb5bb2 | 39 | static bool rpe_enum_p (const_basic_block, const void *); |
0051c76a | 40 | static int find_path (edge, basic_block **); |
7194de72 | 41 | static void fix_loop_placements (struct loop *, bool *); |
42 | static bool fix_bb_placement (basic_block); | |
9f0ac045 | 43 | static void fix_bb_placements (basic_block, bool *, bitmap); |
862be747 | 44 | |
0051c76a | 45 | /* Checks whether basic block BB is dominated by DATA. */ |
6a606e3c | 46 | static bool |
7ecb5bb2 | 47 | rpe_enum_p (const_basic_block bb, const void *data) |
6a606e3c | 48 | { |
7ecb5bb2 | 49 | return dominated_by_p (CDI_DOMINATORS, bb, (const_basic_block) data); |
6a606e3c | 50 | } |
51 | ||
88e6f696 | 52 | /* Remove basic blocks BBS. NBBS is the number of the basic blocks. */ |
53 | ||
6a606e3c | 54 | static void |
0051c76a | 55 | remove_bbs (basic_block *bbs, int nbbs) |
6a606e3c | 56 | { |
57 | int i; | |
58 | ||
59 | for (i = 0; i < nbbs; i++) | |
88e6f696 | 60 | delete_basic_block (bbs[i]); |
6a606e3c | 61 | } |
62 | ||
63 | /* Find path -- i.e. the basic blocks dominated by edge E and put them | |
64 | into array BBS, that will be allocated large enough to contain them. | |
a5414ff5 | 65 | E->dest must have exactly one predecessor for this to work (it is |
66 | easy to achieve and we do not put it here because we do not want to | |
67 | alter anything by this function). The number of basic blocks in the | |
68 | path is returned. */ | |
6a606e3c | 69 | static int |
0051c76a | 70 | find_path (edge e, basic_block **bbs) |
6a606e3c | 71 | { |
cd665a06 | 72 | gcc_assert (EDGE_COUNT (e->dest->preds) <= 1); |
6a606e3c | 73 | |
74 | /* Find bbs in the path. */ | |
a28770e1 | 75 | *bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
6a606e3c | 76 | return dfs_enumerate_from (e->dest, 0, rpe_enum_p, *bbs, |
a28770e1 | 77 | n_basic_blocks_for_fn (cfun), e->dest); |
6a606e3c | 78 | } |
79 | ||
7194de72 | 80 | /* Fix placement of basic block BB inside loop hierarchy -- |
6a606e3c | 81 | Let L be a loop to that BB belongs. Then every successor of BB must either |
82 | 1) belong to some superloop of loop L, or | |
83 | 2) be a header of loop K such that K->outer is superloop of L | |
84 | Returns true if we had to move BB into other loop to enforce this condition, | |
85 | false if the placement of BB was already correct (provided that placements | |
86 | of its successors are correct). */ | |
87 | static bool | |
7194de72 | 88 | fix_bb_placement (basic_block bb) |
6a606e3c | 89 | { |
90 | edge e; | |
cd665a06 | 91 | edge_iterator ei; |
7194de72 | 92 | struct loop *loop = current_loops->tree_root, *act; |
6a606e3c | 93 | |
cd665a06 | 94 | FOR_EACH_EDGE (e, ei, bb->succs) |
6a606e3c | 95 | { |
34154e27 | 96 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
6a606e3c | 97 | continue; |
98 | ||
99 | act = e->dest->loop_father; | |
100 | if (act->header == e->dest) | |
9e3536f4 | 101 | act = loop_outer (act); |
6a606e3c | 102 | |
103 | if (flow_loop_nested_p (loop, act)) | |
104 | loop = act; | |
105 | } | |
106 | ||
107 | if (loop == bb->loop_father) | |
108 | return false; | |
109 | ||
110 | remove_bb_from_loops (bb); | |
111 | add_bb_to_loop (bb, loop); | |
112 | ||
113 | return true; | |
114 | } | |
115 | ||
99b6a86e | 116 | /* Fix placement of LOOP inside loop tree, i.e. find the innermost superloop |
117 | of LOOP to that leads at least one exit edge of LOOP, and set it | |
118 | as the immediate superloop of LOOP. Return true if the immediate superloop | |
c1f96968 | 119 | of LOOP changed. |
120 | ||
121 | IRRED_INVALIDATED is set to true if a change in the loop structures might | |
122 | invalidate the information about irreducible regions. */ | |
99b6a86e | 123 | |
124 | static bool | |
c1f96968 | 125 | fix_loop_placement (struct loop *loop, bool *irred_invalidated) |
99b6a86e | 126 | { |
127 | unsigned i; | |
128 | edge e; | |
f1f41a6c | 129 | vec<edge> exits = get_loop_exit_edges (loop); |
99b6a86e | 130 | struct loop *father = current_loops->tree_root, *act; |
131 | bool ret = false; | |
132 | ||
f1f41a6c | 133 | FOR_EACH_VEC_ELT (exits, i, e) |
99b6a86e | 134 | { |
135 | act = find_common_loop (loop, e->dest->loop_father); | |
136 | if (flow_loop_nested_p (father, act)) | |
137 | father = act; | |
138 | } | |
139 | ||
9e3536f4 | 140 | if (father != loop_outer (loop)) |
99b6a86e | 141 | { |
9e3536f4 | 142 | for (act = loop_outer (loop); act != father; act = loop_outer (act)) |
99b6a86e | 143 | act->num_nodes -= loop->num_nodes; |
144 | flow_loop_tree_node_remove (loop); | |
145 | flow_loop_tree_node_add (father, loop); | |
146 | ||
147 | /* The exit edges of LOOP no longer exits its original immediate | |
148 | superloops; remove them from the appropriate exit lists. */ | |
f1f41a6c | 149 | FOR_EACH_VEC_ELT (exits, i, e) |
c1f96968 | 150 | { |
151 | /* We may need to recompute irreducible loops. */ | |
152 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
153 | *irred_invalidated = true; | |
154 | rescan_loop_exit (e, false, false); | |
155 | } | |
99b6a86e | 156 | |
157 | ret = true; | |
158 | } | |
159 | ||
f1f41a6c | 160 | exits.release (); |
99b6a86e | 161 | return ret; |
162 | } | |
163 | ||
6a606e3c | 164 | /* Fix placements of basic blocks inside loop hierarchy stored in loops; i.e. |
47ae02b7 | 165 | enforce condition stated in description of fix_bb_placement. We |
6a606e3c | 166 | start from basic block FROM that had some of its successors removed, so that |
167 | his placement no longer has to be correct, and iteratively fix placement of | |
168 | its predecessors that may change if placement of FROM changed. Also fix | |
169 | placement of subloops of FROM->loop_father, that might also be altered due | |
917bbcab | 170 | to this change; the condition for them is similar, except that instead of |
afd8eb66 | 171 | successors we consider edges coming out of the loops. |
48e1416a | 172 | |
afd8eb66 | 173 | If the changes may invalidate the information about irreducible regions, |
9f0ac045 | 174 | IRRED_INVALIDATED is set to true. |
175 | ||
176 | If LOOP_CLOSED_SSA_INVLIDATED is non-zero then all basic blocks with | |
177 | changed loop_father are collected there. */ | |
afd8eb66 | 178 | |
6a606e3c | 179 | static void |
7194de72 | 180 | fix_bb_placements (basic_block from, |
9f0ac045 | 181 | bool *irred_invalidated, |
182 | bitmap loop_closed_ssa_invalidated) | |
6a606e3c | 183 | { |
6a606e3c | 184 | basic_block *queue, *qtop, *qbeg, *qend; |
6e05e600 | 185 | struct loop *base_loop, *target_loop; |
6a606e3c | 186 | edge e; |
187 | ||
188 | /* We pass through blocks back-reachable from FROM, testing whether some | |
189 | of their successors moved to outer loop. It may be necessary to | |
190 | iterate several times, but it is finite, as we stop unless we move | |
191 | the basic block up the loop structure. The whole story is a bit | |
192 | more complicated due to presence of subloops, those are moved using | |
193 | fix_loop_placement. */ | |
194 | ||
195 | base_loop = from->loop_father; | |
68fb4bc0 | 196 | /* If we are already in the outermost loop, the basic blocks cannot be moved |
197 | outside of it. If FROM is the header of the base loop, it cannot be moved | |
198 | outside of it, either. In both cases, we can end now. */ | |
199 | if (base_loop == current_loops->tree_root | |
200 | || from == base_loop->header) | |
6a606e3c | 201 | return; |
202 | ||
3c6549f8 | 203 | auto_sbitmap in_queue (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 204 | bitmap_clear (in_queue); |
08b7917c | 205 | bitmap_set_bit (in_queue, from->index); |
6a606e3c | 206 | /* Prevent us from going out of the base_loop. */ |
08b7917c | 207 | bitmap_set_bit (in_queue, base_loop->header->index); |
6a606e3c | 208 | |
4c36ffe6 | 209 | queue = XNEWVEC (basic_block, base_loop->num_nodes + 1); |
6a606e3c | 210 | qtop = queue + base_loop->num_nodes + 1; |
211 | qbeg = queue; | |
212 | qend = queue + 1; | |
213 | *qbeg = from; | |
214 | ||
215 | while (qbeg != qend) | |
216 | { | |
cd665a06 | 217 | edge_iterator ei; |
6a606e3c | 218 | from = *qbeg; |
219 | qbeg++; | |
220 | if (qbeg == qtop) | |
221 | qbeg = queue; | |
08b7917c | 222 | bitmap_clear_bit (in_queue, from->index); |
6a606e3c | 223 | |
224 | if (from->loop_father->header == from) | |
225 | { | |
226 | /* Subloop header, maybe move the loop upward. */ | |
c1f96968 | 227 | if (!fix_loop_placement (from->loop_father, irred_invalidated)) |
6a606e3c | 228 | continue; |
6e05e600 | 229 | target_loop = loop_outer (from->loop_father); |
9cad916b | 230 | if (loop_closed_ssa_invalidated) |
231 | { | |
232 | basic_block *bbs = get_loop_body (from->loop_father); | |
233 | for (unsigned i = 0; i < from->loop_father->num_nodes; ++i) | |
234 | bitmap_set_bit (loop_closed_ssa_invalidated, bbs[i]->index); | |
235 | free (bbs); | |
236 | } | |
6a606e3c | 237 | } |
238 | else | |
239 | { | |
240 | /* Ordinary basic block. */ | |
7194de72 | 241 | if (!fix_bb_placement (from)) |
6a606e3c | 242 | continue; |
9cad916b | 243 | target_loop = from->loop_father; |
9f0ac045 | 244 | if (loop_closed_ssa_invalidated) |
245 | bitmap_set_bit (loop_closed_ssa_invalidated, from->index); | |
6a606e3c | 246 | } |
247 | ||
afd8eb66 | 248 | FOR_EACH_EDGE (e, ei, from->succs) |
249 | { | |
250 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
251 | *irred_invalidated = true; | |
252 | } | |
253 | ||
6a606e3c | 254 | /* Something has changed, insert predecessors into queue. */ |
cd665a06 | 255 | FOR_EACH_EDGE (e, ei, from->preds) |
6a606e3c | 256 | { |
257 | basic_block pred = e->src; | |
258 | struct loop *nca; | |
259 | ||
afd8eb66 | 260 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
261 | *irred_invalidated = true; | |
262 | ||
08b7917c | 263 | if (bitmap_bit_p (in_queue, pred->index)) |
6a606e3c | 264 | continue; |
265 | ||
4c9e08a4 | 266 | /* If it is subloop, then it either was not moved, or |
6a606e3c | 267 | the path up the loop tree from base_loop do not contain |
268 | it. */ | |
269 | nca = find_common_loop (pred->loop_father, base_loop); | |
270 | if (pred->loop_father != base_loop | |
271 | && (nca == base_loop | |
272 | || nca != pred->loop_father)) | |
273 | pred = pred->loop_father->header; | |
6e05e600 | 274 | else if (!flow_loop_nested_p (target_loop, pred->loop_father)) |
6a606e3c | 275 | { |
6e05e600 | 276 | /* If PRED is already higher in the loop hierarchy than the |
277 | TARGET_LOOP to that we moved FROM, the change of the position | |
278 | of FROM does not affect the position of PRED, so there is no | |
279 | point in processing it. */ | |
6a606e3c | 280 | continue; |
281 | } | |
282 | ||
08b7917c | 283 | if (bitmap_bit_p (in_queue, pred->index)) |
6a606e3c | 284 | continue; |
285 | ||
286 | /* Schedule the basic block. */ | |
287 | *qend = pred; | |
288 | qend++; | |
289 | if (qend == qtop) | |
290 | qend = queue; | |
08b7917c | 291 | bitmap_set_bit (in_queue, pred->index); |
6a606e3c | 292 | } |
293 | } | |
6a606e3c | 294 | free (queue); |
295 | } | |
296 | ||
297 | /* Removes path beginning at edge E, i.e. remove basic blocks dominated by E | |
7194de72 | 298 | and update loop structures and dominators. Return true if we were able |
299 | to remove the path, false otherwise (and nothing is affected then). */ | |
6a606e3c | 300 | bool |
7465dbcd | 301 | remove_path (edge e, bool *irred_invalidated, |
302 | bitmap loop_closed_ssa_invalidated) | |
6a606e3c | 303 | { |
304 | edge ae; | |
3f9439d7 | 305 | basic_block *rem_bbs, *bord_bbs, from, bb; |
f1f41a6c | 306 | vec<basic_block> dom_bbs; |
1004aace | 307 | int i, nrem, n_bord_bbs; |
7465dbcd | 308 | bool local_irred_invalidated = false; |
4d50c498 | 309 | edge_iterator ei; |
753f2949 | 310 | struct loop *l, *f; |
6a606e3c | 311 | |
7465dbcd | 312 | if (! irred_invalidated) |
313 | irred_invalidated = &local_irred_invalidated; | |
314 | ||
611d2ac1 | 315 | if (!can_remove_branch_p (e)) |
a5414ff5 | 316 | return false; |
317 | ||
afd8eb66 | 318 | /* Keep track of whether we need to update information about irreducible |
319 | regions. This is the case if the removed area is a part of the | |
320 | irreducible region, or if the set of basic blocks that belong to a loop | |
321 | that is inside an irreducible region is changed, or if such a loop is | |
322 | removed. */ | |
323 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
7465dbcd | 324 | *irred_invalidated = true; |
afd8eb66 | 325 | |
a5414ff5 | 326 | /* We need to check whether basic blocks are dominated by the edge |
327 | e, but we only have basic block dominators. This is easy to | |
328 | fix -- when e->dest has exactly one predecessor, this corresponds | |
329 | to blocks dominated by e->dest, if not, split the edge. */ | |
ea091dfd | 330 | if (!single_pred_p (e->dest)) |
88e6f696 | 331 | e = single_pred_edge (split_edge (e)); |
a5414ff5 | 332 | |
333 | /* It may happen that by removing path we remove one or more loops | |
334 | we belong to. In this case first unloop the loops, then proceed | |
335 | normally. We may assume that e->dest is not a header of any loop, | |
336 | as it now has exactly one predecessor. */ | |
753f2949 | 337 | for (l = e->src->loop_father; loop_outer (l); l = f) |
338 | { | |
339 | f = loop_outer (l); | |
340 | if (dominated_by_p (CDI_DOMINATORS, l->latch, e->dest)) | |
7465dbcd | 341 | unloop (l, irred_invalidated, loop_closed_ssa_invalidated); |
753f2949 | 342 | } |
4c9e08a4 | 343 | |
a5414ff5 | 344 | /* Identify the path. */ |
0051c76a | 345 | nrem = find_path (e, &rem_bbs); |
6a606e3c | 346 | |
347 | n_bord_bbs = 0; | |
a28770e1 | 348 | bord_bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
3c6549f8 | 349 | auto_sbitmap seen (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 350 | bitmap_clear (seen); |
6a606e3c | 351 | |
352 | /* Find "border" hexes -- i.e. those with predecessor in removed path. */ | |
353 | for (i = 0; i < nrem; i++) | |
08b7917c | 354 | bitmap_set_bit (seen, rem_bbs[i]->index); |
7465dbcd | 355 | if (!*irred_invalidated) |
4d50c498 | 356 | FOR_EACH_EDGE (ae, ei, e->src->succs) |
34154e27 | 357 | if (ae != e && ae->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
358 | && !bitmap_bit_p (seen, ae->dest->index) | |
4d50c498 | 359 | && ae->flags & EDGE_IRREDUCIBLE_LOOP) |
b766ccbc | 360 | { |
7465dbcd | 361 | *irred_invalidated = true; |
b766ccbc | 362 | break; |
363 | } | |
364 | ||
a5414ff5 | 365 | for (i = 0; i < nrem; i++) |
6a606e3c | 366 | { |
a5414ff5 | 367 | bb = rem_bbs[i]; |
cd665a06 | 368 | FOR_EACH_EDGE (ae, ei, rem_bbs[i]->succs) |
34154e27 | 369 | if (ae->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
370 | && !bitmap_bit_p (seen, ae->dest->index)) | |
a5414ff5 | 371 | { |
08b7917c | 372 | bitmap_set_bit (seen, ae->dest->index); |
a5414ff5 | 373 | bord_bbs[n_bord_bbs++] = ae->dest; |
48e1416a | 374 | |
afd8eb66 | 375 | if (ae->flags & EDGE_IRREDUCIBLE_LOOP) |
7465dbcd | 376 | *irred_invalidated = true; |
a5414ff5 | 377 | } |
6a606e3c | 378 | } |
6a606e3c | 379 | |
380 | /* Remove the path. */ | |
381 | from = e->src; | |
611d2ac1 | 382 | remove_branch (e); |
f1f41a6c | 383 | dom_bbs.create (0); |
6a606e3c | 384 | |
385 | /* Cancel loops contained in the path. */ | |
386 | for (i = 0; i < nrem; i++) | |
387 | if (rem_bbs[i]->loop_father->header == rem_bbs[i]) | |
1004aace | 388 | cancel_loop_tree (rem_bbs[i]->loop_father); |
88e6f696 | 389 | |
16ccc50c | 390 | remove_bbs (rem_bbs, nrem); |
391 | free (rem_bbs); | |
392 | ||
a5414ff5 | 393 | /* Find blocks whose dominators may be affected. */ |
53c5d9d4 | 394 | bitmap_clear (seen); |
6a606e3c | 395 | for (i = 0; i < n_bord_bbs; i++) |
396 | { | |
0051c76a | 397 | basic_block ldom; |
6a606e3c | 398 | |
0051c76a | 399 | bb = get_immediate_dominator (CDI_DOMINATORS, bord_bbs[i]); |
08b7917c | 400 | if (bitmap_bit_p (seen, bb->index)) |
6a606e3c | 401 | continue; |
08b7917c | 402 | bitmap_set_bit (seen, bb->index); |
6a606e3c | 403 | |
0051c76a | 404 | for (ldom = first_dom_son (CDI_DOMINATORS, bb); |
405 | ldom; | |
406 | ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
407 | if (!dominated_by_p (CDI_DOMINATORS, from, ldom)) | |
f1f41a6c | 408 | dom_bbs.safe_push (ldom); |
6a606e3c | 409 | } |
410 | ||
6a606e3c | 411 | /* Recount dominators. */ |
3f9439d7 | 412 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, true); |
f1f41a6c | 413 | dom_bbs.release (); |
a5414ff5 | 414 | free (bord_bbs); |
415 | ||
6a606e3c | 416 | /* Fix placements of basic blocks inside loops and the placement of |
417 | loops in the loop tree. */ | |
7465dbcd | 418 | fix_bb_placements (from, irred_invalidated, loop_closed_ssa_invalidated); |
419 | fix_loop_placements (from->loop_father, irred_invalidated); | |
afd8eb66 | 420 | |
7465dbcd | 421 | if (local_irred_invalidated |
f24ec26f | 422 | && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
7194de72 | 423 | mark_irreducible_loops (); |
6a606e3c | 424 | |
425 | return true; | |
426 | } | |
427 | ||
41f75a99 | 428 | /* Creates place for a new LOOP in loops structure of FN. */ |
4a6f9e19 | 429 | |
f6568ea4 | 430 | void |
41f75a99 | 431 | place_new_loop (struct function *fn, struct loop *loop) |
6a606e3c | 432 | { |
41f75a99 | 433 | loop->num = number_of_loops (fn); |
434 | vec_safe_push (loops_for_fn (fn)->larray, loop); | |
6a606e3c | 435 | } |
436 | ||
437 | /* Given LOOP structure with filled header and latch, find the body of the | |
7194de72 | 438 | corresponding loop and add it to loops tree. Insert the LOOP as a son of |
88e6f696 | 439 | outer. */ |
440 | ||
4a6f9e19 | 441 | void |
7194de72 | 442 | add_loop (struct loop *loop, struct loop *outer) |
6a606e3c | 443 | { |
444 | basic_block *bbs; | |
445 | int i, n; | |
4a6f9e19 | 446 | struct loop *subloop; |
e88bb328 | 447 | edge e; |
448 | edge_iterator ei; | |
4c9e08a4 | 449 | |
6a606e3c | 450 | /* Add it to loop structure. */ |
41f75a99 | 451 | place_new_loop (cfun, loop); |
88e6f696 | 452 | flow_loop_tree_node_add (outer, loop); |
6a606e3c | 453 | |
454 | /* Find its nodes. */ | |
a28770e1 | 455 | bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
456 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); | |
6a606e3c | 457 | |
458 | for (i = 0; i < n; i++) | |
88e6f696 | 459 | { |
4a6f9e19 | 460 | if (bbs[i]->loop_father == outer) |
461 | { | |
462 | remove_bb_from_loops (bbs[i]); | |
463 | add_bb_to_loop (bbs[i], loop); | |
464 | continue; | |
465 | } | |
466 | ||
467 | loop->num_nodes++; | |
468 | ||
469 | /* If we find a direct subloop of OUTER, move it to LOOP. */ | |
470 | subloop = bbs[i]->loop_father; | |
9e3536f4 | 471 | if (loop_outer (subloop) == outer |
4a6f9e19 | 472 | && subloop->header == bbs[i]) |
473 | { | |
474 | flow_loop_tree_node_remove (subloop); | |
475 | flow_loop_tree_node_add (loop, subloop); | |
476 | } | |
88e6f696 | 477 | } |
6a606e3c | 478 | |
e88bb328 | 479 | /* Update the information about loop exit edges. */ |
480 | for (i = 0; i < n; i++) | |
481 | { | |
482 | FOR_EACH_EDGE (e, ei, bbs[i]->succs) | |
483 | { | |
484 | rescan_loop_exit (e, false, false); | |
485 | } | |
486 | } | |
487 | ||
6a606e3c | 488 | free (bbs); |
489 | } | |
490 | ||
6a606e3c | 491 | /* Multiply all frequencies in LOOP by NUM/DEN. */ |
dbaa22a9 | 492 | |
7cef6c97 | 493 | void |
4c9e08a4 | 494 | scale_loop_frequencies (struct loop *loop, int num, int den) |
6a606e3c | 495 | { |
496 | basic_block *bbs; | |
497 | ||
498 | bbs = get_loop_body (loop); | |
4d6b11ab | 499 | scale_bbs_frequencies_int (bbs, loop->num_nodes, num, den); |
6a606e3c | 500 | free (bbs); |
501 | } | |
502 | ||
dbaa22a9 | 503 | /* Multiply all frequencies in LOOP by SCALE/REG_BR_PROB_BASE. |
504 | If ITERATION_BOUND is non-zero, scale even further if loop is predicted | |
505 | to iterate too many times. */ | |
506 | ||
507 | void | |
dde4834c | 508 | scale_loop_profile (struct loop *loop, int scale, gcov_type iteration_bound) |
dbaa22a9 | 509 | { |
510 | gcov_type iterations = expected_loop_iterations_unbounded (loop); | |
511 | edge e; | |
512 | edge_iterator ei; | |
513 | ||
514 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
515 | fprintf (dump_file, ";; Scaling loop %i with scale %f, " | |
516 | "bounding iterations to %i from guessed %i\n", | |
517 | loop->num, (double)scale / REG_BR_PROB_BASE, | |
dde4834c | 518 | (int)iteration_bound, (int)iterations); |
dbaa22a9 | 519 | |
520 | /* See if loop is predicted to iterate too many times. */ | |
521 | if (iteration_bound && iterations > 0 | |
f9d4b7f4 | 522 | && apply_probability (iterations, scale) > iteration_bound) |
dbaa22a9 | 523 | { |
524 | /* Fixing loop profile for different trip count is not trivial; the exit | |
525 | probabilities has to be updated to match and frequencies propagated down | |
526 | to the loop body. | |
527 | ||
528 | We fully update only the simple case of loop with single exit that is | |
529 | either from the latch or BB just before latch and leads from BB with | |
530 | simple conditional jump. This is OK for use in vectorizer. */ | |
531 | e = single_exit (loop); | |
532 | if (e) | |
533 | { | |
534 | edge other_e; | |
535 | int freq_delta; | |
db9cef39 | 536 | profile_count count_delta; |
dbaa22a9 | 537 | |
538 | FOR_EACH_EDGE (other_e, ei, e->src->succs) | |
539 | if (!(other_e->flags & (EDGE_ABNORMAL | EDGE_FAKE)) | |
540 | && e != other_e) | |
541 | break; | |
542 | ||
543 | /* Probability of exit must be 1/iterations. */ | |
544 | freq_delta = EDGE_FREQUENCY (e); | |
545 | e->probability = REG_BR_PROB_BASE / iteration_bound; | |
546 | other_e->probability = inverse_probability (e->probability); | |
547 | freq_delta -= EDGE_FREQUENCY (e); | |
548 | ||
549 | /* Adjust counts accordingly. */ | |
550 | count_delta = e->count; | |
db9cef39 | 551 | e->count = e->src->count.apply_probability (e->probability); |
552 | other_e->count = e->src->count.apply_probability (other_e->probability); | |
dbaa22a9 | 553 | count_delta -= e->count; |
554 | ||
555 | /* If latch exists, change its frequency and count, since we changed | |
556 | probability of exit. Theoretically we should update everything from | |
557 | source of exit edge to latch, but for vectorizer this is enough. */ | |
558 | if (loop->latch | |
559 | && loop->latch != e->src) | |
560 | { | |
561 | loop->latch->frequency += freq_delta; | |
562 | if (loop->latch->frequency < 0) | |
563 | loop->latch->frequency = 0; | |
564 | loop->latch->count += count_delta; | |
dbaa22a9 | 565 | } |
566 | } | |
567 | ||
568 | /* Roughly speaking we want to reduce the loop body profile by the | |
4bec4fee | 569 | difference of loop iterations. We however can do better if |
dbaa22a9 | 570 | we look at the actual profile, if it is available. */ |
571 | scale = RDIV (iteration_bound * scale, iterations); | |
db9cef39 | 572 | |
573 | bool determined = false; | |
574 | if (loop->header->count.initialized_p ()) | |
dbaa22a9 | 575 | { |
db9cef39 | 576 | profile_count count_in = profile_count::zero (); |
dbaa22a9 | 577 | |
578 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
579 | if (e->src != loop->latch) | |
580 | count_in += e->count; | |
581 | ||
db9cef39 | 582 | if (count_in > profile_count::zero () ) |
583 | { | |
584 | scale = GCOV_COMPUTE_SCALE (count_in.to_gcov_type () | |
585 | * iteration_bound, | |
586 | loop->header->count.to_gcov_type ()); | |
587 | determined = true; | |
588 | } | |
dbaa22a9 | 589 | } |
db9cef39 | 590 | if (!determined) |
dbaa22a9 | 591 | { |
592 | int freq_in = 0; | |
593 | ||
594 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
595 | if (e->src != loop->latch) | |
596 | freq_in += EDGE_FREQUENCY (e); | |
597 | ||
598 | if (freq_in != 0) | |
f9d4b7f4 | 599 | scale = GCOV_COMPUTE_SCALE (freq_in * iteration_bound, |
600 | loop->header->frequency); | |
dbaa22a9 | 601 | } |
602 | if (!scale) | |
603 | scale = 1; | |
604 | } | |
605 | ||
606 | if (scale == REG_BR_PROB_BASE) | |
607 | return; | |
608 | ||
609 | /* Scale the actual probabilities. */ | |
610 | scale_loop_frequencies (loop, scale, REG_BR_PROB_BASE); | |
611 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
612 | fprintf (dump_file, ";; guessed iterations are now %i\n", | |
613 | (int)expected_loop_iterations_unbounded (loop)); | |
614 | } | |
615 | ||
255b6be7 | 616 | /* Recompute dominance information for basic blocks outside LOOP. */ |
617 | ||
618 | static void | |
619 | update_dominators_in_loop (struct loop *loop) | |
620 | { | |
1e094109 | 621 | vec<basic_block> dom_bbs = vNULL; |
255b6be7 | 622 | basic_block *body; |
623 | unsigned i; | |
624 | ||
3c6549f8 | 625 | auto_sbitmap seen (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 626 | bitmap_clear (seen); |
255b6be7 | 627 | body = get_loop_body (loop); |
628 | ||
629 | for (i = 0; i < loop->num_nodes; i++) | |
08b7917c | 630 | bitmap_set_bit (seen, body[i]->index); |
255b6be7 | 631 | |
632 | for (i = 0; i < loop->num_nodes; i++) | |
633 | { | |
634 | basic_block ldom; | |
635 | ||
636 | for (ldom = first_dom_son (CDI_DOMINATORS, body[i]); | |
637 | ldom; | |
638 | ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
08b7917c | 639 | if (!bitmap_bit_p (seen, ldom->index)) |
255b6be7 | 640 | { |
08b7917c | 641 | bitmap_set_bit (seen, ldom->index); |
f1f41a6c | 642 | dom_bbs.safe_push (ldom); |
255b6be7 | 643 | } |
644 | } | |
645 | ||
646 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false); | |
647 | free (body); | |
f1f41a6c | 648 | dom_bbs.release (); |
255b6be7 | 649 | } |
650 | ||
651 | /* Creates an if region as shown above. CONDITION is used to create | |
48e1416a | 652 | the test for the if. |
255b6be7 | 653 | |
654 | | | |
655 | | ------------- ------------- | |
656 | | | pred_bb | | pred_bb | | |
657 | | ------------- ------------- | |
658 | | | | | |
659 | | | | ENTRY_EDGE | |
660 | | | ENTRY_EDGE V | |
661 | | | ====> ------------- | |
662 | | | | cond_bb | | |
663 | | | | CONDITION | | |
664 | | | ------------- | |
665 | | V / \ | |
666 | | ------------- e_false / \ e_true | |
667 | | | succ_bb | V V | |
668 | | ------------- ----------- ----------- | |
669 | | | false_bb | | true_bb | | |
670 | | ----------- ----------- | |
671 | | \ / | |
672 | | \ / | |
673 | | V V | |
674 | | ------------- | |
675 | | | join_bb | | |
676 | | ------------- | |
677 | | | exit_edge (result) | |
678 | | V | |
679 | | ----------- | |
680 | | | succ_bb | | |
681 | | ----------- | |
682 | | | |
683 | */ | |
684 | ||
685 | edge | |
686 | create_empty_if_region_on_edge (edge entry_edge, tree condition) | |
687 | { | |
688 | ||
6d86fc31 | 689 | basic_block cond_bb, true_bb, false_bb, join_bb; |
255b6be7 | 690 | edge e_true, e_false, exit_edge; |
1a91d914 | 691 | gcond *cond_stmt; |
255b6be7 | 692 | tree simple_cond; |
693 | gimple_stmt_iterator gsi; | |
694 | ||
255b6be7 | 695 | cond_bb = split_edge (entry_edge); |
48e1416a | 696 | |
255b6be7 | 697 | /* Insert condition in cond_bb. */ |
698 | gsi = gsi_last_bb (cond_bb); | |
699 | simple_cond = | |
700 | force_gimple_operand_gsi (&gsi, condition, true, NULL, | |
701 | false, GSI_NEW_STMT); | |
702 | cond_stmt = gimple_build_cond_from_tree (simple_cond, NULL_TREE, NULL_TREE); | |
703 | gsi = gsi_last_bb (cond_bb); | |
704 | gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT); | |
48e1416a | 705 | |
255b6be7 | 706 | join_bb = split_edge (single_succ_edge (cond_bb)); |
707 | ||
708 | e_true = single_succ_edge (cond_bb); | |
709 | true_bb = split_edge (e_true); | |
710 | ||
711 | e_false = make_edge (cond_bb, join_bb, 0); | |
712 | false_bb = split_edge (e_false); | |
713 | ||
714 | e_true->flags &= ~EDGE_FALLTHRU; | |
715 | e_true->flags |= EDGE_TRUE_VALUE; | |
716 | e_false->flags &= ~EDGE_FALLTHRU; | |
717 | e_false->flags |= EDGE_FALSE_VALUE; | |
718 | ||
719 | set_immediate_dominator (CDI_DOMINATORS, cond_bb, entry_edge->src); | |
720 | set_immediate_dominator (CDI_DOMINATORS, true_bb, cond_bb); | |
721 | set_immediate_dominator (CDI_DOMINATORS, false_bb, cond_bb); | |
722 | set_immediate_dominator (CDI_DOMINATORS, join_bb, cond_bb); | |
723 | ||
724 | exit_edge = single_succ_edge (join_bb); | |
725 | ||
726 | if (single_pred_p (exit_edge->dest)) | |
727 | set_immediate_dominator (CDI_DOMINATORS, exit_edge->dest, join_bb); | |
728 | ||
729 | return exit_edge; | |
730 | } | |
731 | ||
732 | /* create_empty_loop_on_edge | |
733 | | | |
b65ec27f | 734 | | - pred_bb - ------ pred_bb ------ |
735 | | | | | iv0 = initial_value | | |
736 | | -----|----- ---------|----------- | |
737 | | | ______ | entry_edge | |
738 | | | entry_edge / | | | |
739 | | | ====> | -V---V- loop_header ------------- | |
740 | | V | | iv_before = phi (iv0, iv_after) | | |
741 | | - succ_bb - | ---|----------------------------- | |
742 | | | | | | | |
743 | | ----------- | ---V--- loop_body --------------- | |
744 | | | | iv_after = iv_before + stride | | |
02df46c6 | 745 | | | | if (iv_before < upper_bound) | |
b65ec27f | 746 | | | ---|--------------\-------------- |
747 | | | | \ exit_e | |
748 | | | V \ | |
749 | | | - loop_latch - V- succ_bb - | |
750 | | | | | | | | |
751 | | | /------------- ----------- | |
752 | | \ ___ / | |
255b6be7 | 753 | |
754 | Creates an empty loop as shown above, the IV_BEFORE is the SSA_NAME | |
02df46c6 | 755 | that is used before the increment of IV. IV_BEFORE should be used for |
255b6be7 | 756 | adding code to the body that uses the IV. OUTER is the outer loop in |
02df46c6 | 757 | which the new loop should be inserted. |
b65ec27f | 758 | |
759 | Both INITIAL_VALUE and UPPER_BOUND expressions are gimplified and | |
760 | inserted on the loop entry edge. This implies that this function | |
761 | should be used only when the UPPER_BOUND expression is a loop | |
762 | invariant. */ | |
255b6be7 | 763 | |
764 | struct loop * | |
02df46c6 | 765 | create_empty_loop_on_edge (edge entry_edge, |
255b6be7 | 766 | tree initial_value, |
767 | tree stride, tree upper_bound, | |
768 | tree iv, | |
769 | tree *iv_before, | |
b65ec27f | 770 | tree *iv_after, |
255b6be7 | 771 | struct loop *outer) |
772 | { | |
773 | basic_block loop_header, loop_latch, succ_bb, pred_bb; | |
774 | struct loop *loop; | |
255b6be7 | 775 | gimple_stmt_iterator gsi; |
255b6be7 | 776 | gimple_seq stmts; |
1a91d914 | 777 | gcond *cond_expr; |
255b6be7 | 778 | tree exit_test; |
779 | edge exit_e; | |
780 | int prob; | |
02df46c6 | 781 | |
255b6be7 | 782 | gcc_assert (entry_edge && initial_value && stride && upper_bound && iv); |
783 | ||
784 | /* Create header, latch and wire up the loop. */ | |
785 | pred_bb = entry_edge->src; | |
786 | loop_header = split_edge (entry_edge); | |
787 | loop_latch = split_edge (single_succ_edge (loop_header)); | |
788 | succ_bb = single_succ (loop_latch); | |
789 | make_edge (loop_header, succ_bb, 0); | |
790 | redirect_edge_succ_nodup (single_succ_edge (loop_latch), loop_header); | |
791 | ||
792 | /* Set immediate dominator information. */ | |
793 | set_immediate_dominator (CDI_DOMINATORS, loop_header, pred_bb); | |
794 | set_immediate_dominator (CDI_DOMINATORS, loop_latch, loop_header); | |
795 | set_immediate_dominator (CDI_DOMINATORS, succ_bb, loop_header); | |
796 | ||
797 | /* Initialize a loop structure and put it in a loop hierarchy. */ | |
798 | loop = alloc_loop (); | |
799 | loop->header = loop_header; | |
800 | loop->latch = loop_latch; | |
801 | add_loop (loop, outer); | |
802 | ||
803 | /* TODO: Fix frequencies and counts. */ | |
255b6be7 | 804 | prob = REG_BR_PROB_BASE / 2; |
805 | ||
806 | scale_loop_frequencies (loop, REG_BR_PROB_BASE - prob, REG_BR_PROB_BASE); | |
807 | ||
808 | /* Update dominators. */ | |
809 | update_dominators_in_loop (loop); | |
810 | ||
b65ec27f | 811 | /* Modify edge flags. */ |
812 | exit_e = single_exit (loop); | |
813 | exit_e->flags = EDGE_LOOP_EXIT | EDGE_FALSE_VALUE; | |
814 | single_pred_edge (loop_latch)->flags = EDGE_TRUE_VALUE; | |
815 | ||
255b6be7 | 816 | /* Construct IV code in loop. */ |
817 | initial_value = force_gimple_operand (initial_value, &stmts, true, iv); | |
818 | if (stmts) | |
819 | { | |
820 | gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts); | |
821 | gsi_commit_edge_inserts (); | |
822 | } | |
823 | ||
b65ec27f | 824 | upper_bound = force_gimple_operand (upper_bound, &stmts, true, NULL); |
825 | if (stmts) | |
826 | { | |
827 | gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts); | |
828 | gsi_commit_edge_inserts (); | |
829 | } | |
255b6be7 | 830 | |
b65ec27f | 831 | gsi = gsi_last_bb (loop_header); |
832 | create_iv (initial_value, stride, iv, loop, &gsi, false, | |
833 | iv_before, iv_after); | |
255b6be7 | 834 | |
b65ec27f | 835 | /* Insert loop exit condition. */ |
836 | cond_expr = gimple_build_cond | |
02df46c6 | 837 | (LT_EXPR, *iv_before, upper_bound, NULL_TREE, NULL_TREE); |
255b6be7 | 838 | |
839 | exit_test = gimple_cond_lhs (cond_expr); | |
840 | exit_test = force_gimple_operand_gsi (&gsi, exit_test, true, NULL, | |
841 | false, GSI_NEW_STMT); | |
842 | gimple_cond_set_lhs (cond_expr, exit_test); | |
843 | gsi = gsi_last_bb (exit_e->src); | |
844 | gsi_insert_after (&gsi, cond_expr, GSI_NEW_STMT); | |
845 | ||
b65ec27f | 846 | split_block_after_labels (loop_header); |
847 | ||
255b6be7 | 848 | return loop; |
849 | } | |
850 | ||
6a606e3c | 851 | /* Make area between HEADER_EDGE and LATCH_EDGE a loop by connecting |
7194de72 | 852 | latch to header and update loop tree and dominators |
6a606e3c | 853 | accordingly. Everything between them plus LATCH_EDGE destination must |
854 | be dominated by HEADER_EDGE destination, and back-reachable from | |
855 | LATCH_EDGE source. HEADER_EDGE is redirected to basic block SWITCH_BB, | |
0dc32828 | 856 | FALSE_EDGE of SWITCH_BB to original destination of HEADER_EDGE and |
857 | TRUE_EDGE of SWITCH_BB to original destination of LATCH_EDGE. | |
7cef6c97 | 858 | Returns the newly created loop. Frequencies and counts in the new loop |
859 | are scaled by FALSE_SCALE and in the old one by TRUE_SCALE. */ | |
f9cce2dc | 860 | |
6a606e3c | 861 | struct loop * |
7194de72 | 862 | loopify (edge latch_edge, edge header_edge, |
0dc32828 | 863 | basic_block switch_bb, edge true_edge, edge false_edge, |
7cef6c97 | 864 | bool redirect_all_edges, unsigned true_scale, unsigned false_scale) |
6a606e3c | 865 | { |
866 | basic_block succ_bb = latch_edge->dest; | |
867 | basic_block pred_bb = header_edge->src; | |
dce58e66 | 868 | struct loop *loop = alloc_loop (); |
9e3536f4 | 869 | struct loop *outer = loop_outer (succ_bb->loop_father); |
7cef6c97 | 870 | int freq; |
db9cef39 | 871 | profile_count cnt; |
6a606e3c | 872 | edge e; |
cd665a06 | 873 | edge_iterator ei; |
6a606e3c | 874 | |
875 | loop->header = header_edge->dest; | |
876 | loop->latch = latch_edge->src; | |
877 | ||
878 | freq = EDGE_FREQUENCY (header_edge); | |
879 | cnt = header_edge->count; | |
6a606e3c | 880 | |
881 | /* Redirect edges. */ | |
882 | loop_redirect_edge (latch_edge, loop->header); | |
0dc32828 | 883 | loop_redirect_edge (true_edge, succ_bb); |
f9cce2dc | 884 | |
e12d0591 | 885 | /* During loop versioning, one of the switch_bb edge is already properly |
886 | set. Do not redirect it again unless redirect_all_edges is true. */ | |
887 | if (redirect_all_edges) | |
888 | { | |
889 | loop_redirect_edge (header_edge, switch_bb); | |
a0c938f0 | 890 | loop_redirect_edge (false_edge, loop->header); |
891 | ||
e12d0591 | 892 | /* Update dominators. */ |
893 | set_immediate_dominator (CDI_DOMINATORS, switch_bb, pred_bb); | |
894 | set_immediate_dominator (CDI_DOMINATORS, loop->header, switch_bb); | |
895 | } | |
f9cce2dc | 896 | |
0051c76a | 897 | set_immediate_dominator (CDI_DOMINATORS, succ_bb, switch_bb); |
6a606e3c | 898 | |
899 | /* Compute new loop. */ | |
7194de72 | 900 | add_loop (loop, outer); |
6a606e3c | 901 | |
902 | /* Add switch_bb to appropriate loop. */ | |
88e6f696 | 903 | if (switch_bb->loop_father) |
904 | remove_bb_from_loops (switch_bb); | |
6a606e3c | 905 | add_bb_to_loop (switch_bb, outer); |
906 | ||
907 | /* Fix frequencies. */ | |
7cef6c97 | 908 | if (redirect_all_edges) |
909 | { | |
910 | switch_bb->frequency = freq; | |
911 | switch_bb->count = cnt; | |
912 | FOR_EACH_EDGE (e, ei, switch_bb->succs) | |
913 | { | |
db9cef39 | 914 | e->count = switch_bb->count.apply_probability (e->probability); |
7cef6c97 | 915 | } |
916 | } | |
917 | scale_loop_frequencies (loop, false_scale, REG_BR_PROB_BASE); | |
918 | scale_loop_frequencies (succ_bb->loop_father, true_scale, REG_BR_PROB_BASE); | |
255b6be7 | 919 | update_dominators_in_loop (loop); |
6a606e3c | 920 | |
921 | return loop; | |
922 | } | |
923 | ||
7194de72 | 924 | /* Remove the latch edge of a LOOP and update loops to indicate that |
a5414ff5 | 925 | the LOOP was removed. After this function, original loop latch will |
afd8eb66 | 926 | have no successor, which caller is expected to fix somehow. |
927 | ||
928 | If this may cause the information about irreducible regions to become | |
9f0ac045 | 929 | invalid, IRRED_INVALIDATED is set to true. |
930 | ||
931 | LOOP_CLOSED_SSA_INVALIDATED, if non-NULL, is a bitmap where we store | |
932 | basic blocks that had non-trivial update on their loop_father.*/ | |
afd8eb66 | 933 | |
c790d986 | 934 | void |
9f0ac045 | 935 | unloop (struct loop *loop, bool *irred_invalidated, |
936 | bitmap loop_closed_ssa_invalidated) | |
a5414ff5 | 937 | { |
938 | basic_block *body; | |
939 | struct loop *ploop; | |
940 | unsigned i, n; | |
941 | basic_block latch = loop->latch; | |
afd8eb66 | 942 | bool dummy = false; |
943 | ||
944 | if (loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP) | |
945 | *irred_invalidated = true; | |
a5414ff5 | 946 | |
d01481af | 947 | /* This is relatively straightforward. The dominators are unchanged, as |
a5414ff5 | 948 | loop header dominates loop latch, so the only thing we have to care of |
949 | is the placement of loops and basic blocks inside the loop tree. We | |
950 | move them all to the loop->outer, and then let fix_bb_placements do | |
951 | its work. */ | |
952 | ||
953 | body = get_loop_body (loop); | |
a5414ff5 | 954 | n = loop->num_nodes; |
955 | for (i = 0; i < n; i++) | |
956 | if (body[i]->loop_father == loop) | |
957 | { | |
958 | remove_bb_from_loops (body[i]); | |
9e3536f4 | 959 | add_bb_to_loop (body[i], loop_outer (loop)); |
a5414ff5 | 960 | } |
9af5ce0c | 961 | free (body); |
a5414ff5 | 962 | |
963 | while (loop->inner) | |
964 | { | |
965 | ploop = loop->inner; | |
966 | flow_loop_tree_node_remove (ploop); | |
9e3536f4 | 967 | flow_loop_tree_node_add (loop_outer (loop), ploop); |
a5414ff5 | 968 | } |
969 | ||
970 | /* Remove the loop and free its data. */ | |
17519ba0 | 971 | delete_loop (loop); |
a5414ff5 | 972 | |
ea091dfd | 973 | remove_edge (single_succ_edge (latch)); |
afd8eb66 | 974 | |
975 | /* We do not pass IRRED_INVALIDATED to fix_bb_placements here, as even if | |
976 | there is an irreducible region inside the cancelled loop, the flags will | |
977 | be still correct. */ | |
9f0ac045 | 978 | fix_bb_placements (latch, &dummy, loop_closed_ssa_invalidated); |
a5414ff5 | 979 | } |
980 | ||
6a606e3c | 981 | /* Fix placement of superloops of LOOP inside loop tree, i.e. ensure that |
982 | condition stated in description of fix_loop_placement holds for them. | |
983 | It is used in case when we removed some edges coming out of LOOP, which | |
afd8eb66 | 984 | may cause the right placement of LOOP inside loop tree to change. |
48e1416a | 985 | |
afd8eb66 | 986 | IRRED_INVALIDATED is set to true if a change in the loop structures might |
987 | invalidate the information about irreducible regions. */ | |
988 | ||
6a606e3c | 989 | static void |
7194de72 | 990 | fix_loop_placements (struct loop *loop, bool *irred_invalidated) |
6a606e3c | 991 | { |
992 | struct loop *outer; | |
993 | ||
9e3536f4 | 994 | while (loop_outer (loop)) |
6a606e3c | 995 | { |
9e3536f4 | 996 | outer = loop_outer (loop); |
c1f96968 | 997 | if (!fix_loop_placement (loop, irred_invalidated)) |
a0c938f0 | 998 | break; |
82233aad | 999 | |
1000 | /* Changing the placement of a loop in the loop tree may alter the | |
1001 | validity of condition 2) of the description of fix_bb_placement | |
1002 | for its preheader, because the successor is the header and belongs | |
1003 | to the loop. So call fix_bb_placements to fix up the placement | |
1004 | of the preheader and (possibly) of its predecessors. */ | |
7194de72 | 1005 | fix_bb_placements (loop_preheader_edge (loop)->src, |
9f0ac045 | 1006 | irred_invalidated, NULL); |
6a606e3c | 1007 | loop = outer; |
1008 | } | |
1009 | } | |
1010 | ||
efa7c5bd | 1011 | /* Duplicate loop bounds and other information we store about |
1012 | the loop into its duplicate. */ | |
1013 | ||
1014 | void | |
1015 | copy_loop_info (struct loop *loop, struct loop *target) | |
1016 | { | |
1017 | gcc_checking_assert (!target->any_upper_bound && !target->any_estimate); | |
1018 | target->any_upper_bound = loop->any_upper_bound; | |
1019 | target->nb_iterations_upper_bound = loop->nb_iterations_upper_bound; | |
8e3ffe30 | 1020 | target->any_likely_upper_bound = loop->any_likely_upper_bound; |
1021 | target->nb_iterations_likely_upper_bound | |
1022 | = loop->nb_iterations_likely_upper_bound; | |
efa7c5bd | 1023 | target->any_estimate = loop->any_estimate; |
1024 | target->nb_iterations_estimate = loop->nb_iterations_estimate; | |
1025 | target->estimate_state = loop->estimate_state; | |
85168485 | 1026 | target->constraints = loop->constraints; |
a5229641 | 1027 | target->warned_aggressive_loop_optimizations |
1028 | |= loop->warned_aggressive_loop_optimizations; | |
1a40f20b | 1029 | target->in_oacc_kernels_region = loop->in_oacc_kernels_region; |
efa7c5bd | 1030 | } |
1031 | ||
6a606e3c | 1032 | /* Copies copy of LOOP as subloop of TARGET loop, placing newly |
7194de72 | 1033 | created loop into loops structure. */ |
50caf588 | 1034 | struct loop * |
7194de72 | 1035 | duplicate_loop (struct loop *loop, struct loop *target) |
6a606e3c | 1036 | { |
1037 | struct loop *cloop; | |
dce58e66 | 1038 | cloop = alloc_loop (); |
41f75a99 | 1039 | place_new_loop (cfun, cloop); |
efa7c5bd | 1040 | |
1041 | copy_loop_info (loop, cloop); | |
6a606e3c | 1042 | |
8543a448 | 1043 | /* Mark the new loop as copy of LOOP. */ |
96c90e5e | 1044 | set_loop_copy (loop, cloop); |
6a606e3c | 1045 | |
1046 | /* Add it to target. */ | |
1047 | flow_loop_tree_node_add (target, cloop); | |
1048 | ||
1049 | return cloop; | |
1050 | } | |
1051 | ||
1052 | /* Copies structure of subloops of LOOP into TARGET loop, placing | |
7194de72 | 1053 | newly created loops into loop tree. */ |
b0fb253a | 1054 | void |
7194de72 | 1055 | duplicate_subloops (struct loop *loop, struct loop *target) |
6a606e3c | 1056 | { |
1057 | struct loop *aloop, *cloop; | |
1058 | ||
1059 | for (aloop = loop->inner; aloop; aloop = aloop->next) | |
1060 | { | |
7194de72 | 1061 | cloop = duplicate_loop (aloop, target); |
1062 | duplicate_subloops (aloop, cloop); | |
6a606e3c | 1063 | } |
1064 | } | |
1065 | ||
1066 | /* Copies structure of subloops of N loops, stored in array COPIED_LOOPS, | |
7194de72 | 1067 | into TARGET loop, placing newly created loops into loop tree. */ |
4c9e08a4 | 1068 | static void |
7194de72 | 1069 | copy_loops_to (struct loop **copied_loops, int n, struct loop *target) |
6a606e3c | 1070 | { |
1071 | struct loop *aloop; | |
1072 | int i; | |
1073 | ||
1074 | for (i = 0; i < n; i++) | |
1075 | { | |
7194de72 | 1076 | aloop = duplicate_loop (copied_loops[i], target); |
1077 | duplicate_subloops (copied_loops[i], aloop); | |
6a606e3c | 1078 | } |
1079 | } | |
1080 | ||
1081 | /* Redirects edge E to basic block DEST. */ | |
1082 | static void | |
4c9e08a4 | 1083 | loop_redirect_edge (edge e, basic_block dest) |
6a606e3c | 1084 | { |
1085 | if (e->dest == dest) | |
1086 | return; | |
1087 | ||
1026363d | 1088 | redirect_edge_and_branch_force (e, dest); |
6a606e3c | 1089 | } |
1090 | ||
6a606e3c | 1091 | /* Check whether LOOP's body can be duplicated. */ |
1092 | bool | |
7ecb5bb2 | 1093 | can_duplicate_loop_p (const struct loop *loop) |
6a606e3c | 1094 | { |
dbfc1664 | 1095 | int ret; |
1096 | basic_block *bbs = get_loop_body (loop); | |
6a606e3c | 1097 | |
dbfc1664 | 1098 | ret = can_copy_bbs_p (bbs, loop->num_nodes); |
6a606e3c | 1099 | free (bbs); |
a0c938f0 | 1100 | |
dbfc1664 | 1101 | return ret; |
6a606e3c | 1102 | } |
1103 | ||
7cef6c97 | 1104 | /* Sets probability and count of edge E to zero. The probability and count |
1105 | is redistributed evenly to the remaining edges coming from E->src. */ | |
1106 | ||
1107 | static void | |
1108 | set_zero_probability (edge e) | |
1109 | { | |
1110 | basic_block bb = e->src; | |
1111 | edge_iterator ei; | |
1112 | edge ae, last = NULL; | |
1113 | unsigned n = EDGE_COUNT (bb->succs); | |
db9cef39 | 1114 | profile_count cnt = e->count, cnt1; |
7cef6c97 | 1115 | unsigned prob = e->probability, prob1; |
1116 | ||
1117 | gcc_assert (n > 1); | |
db9cef39 | 1118 | cnt1 = cnt.apply_scale (1, (n - 1)); |
7cef6c97 | 1119 | prob1 = prob / (n - 1); |
1120 | ||
1121 | FOR_EACH_EDGE (ae, ei, bb->succs) | |
1122 | { | |
1123 | if (ae == e) | |
1124 | continue; | |
1125 | ||
1126 | ae->probability += prob1; | |
1127 | ae->count += cnt1; | |
1128 | last = ae; | |
1129 | } | |
1130 | ||
1131 | /* Move the rest to one of the edges. */ | |
1132 | last->probability += prob % (n - 1); | |
db9cef39 | 1133 | /* TODO: Remove once we have fractional counts. */ |
1134 | if (cnt.initialized_p ()) | |
1135 | last->count += profile_count::from_gcov_type (cnt.to_gcov_type () % (n - 1)); | |
7cef6c97 | 1136 | |
1137 | e->probability = 0; | |
db9cef39 | 1138 | e->count = profile_count::zero (); |
7cef6c97 | 1139 | } |
1140 | ||
dbfc1664 | 1141 | /* Duplicates body of LOOP to given edge E NDUPL times. Takes care of updating |
7194de72 | 1142 | loop structure and dominators. E's destination must be LOOP header for |
dbfc1664 | 1143 | this to work, i.e. it must be entry or latch edge of this loop; these are |
1144 | unique, as the loops must have preheaders for this function to work | |
1145 | correctly (in case E is latch, the function unrolls the loop, if E is entry | |
1146 | edge, it peels the loop). Store edges created by copying ORIG edge from | |
1147 | copies corresponding to set bits in WONT_EXIT bitmap (bit 0 corresponds to | |
1148 | original LOOP body, the other copies are numbered in order given by control | |
1149 | flow through them) into TO_REMOVE array. Returns false if duplication is | |
1150 | impossible. */ | |
f3c40e6d | 1151 | |
c50ae675 | 1152 | bool |
7194de72 | 1153 | duplicate_loop_to_header_edge (struct loop *loop, edge e, |
4c9e08a4 | 1154 | unsigned int ndupl, sbitmap wont_exit, |
f1f41a6c | 1155 | edge orig, vec<edge> *to_remove, |
f3c40e6d | 1156 | int flags) |
6a606e3c | 1157 | { |
1158 | struct loop *target, *aloop; | |
1159 | struct loop **orig_loops; | |
1160 | unsigned n_orig_loops; | |
1161 | basic_block header = loop->header, latch = loop->latch; | |
1162 | basic_block *new_bbs, *bbs, *first_active; | |
1163 | basic_block new_bb, bb, first_active_latch = NULL; | |
dbfc1664 | 1164 | edge ae, latch_edge; |
1165 | edge spec_edges[2], new_spec_edges[2]; | |
1166 | #define SE_LATCH 0 | |
1167 | #define SE_ORIG 1 | |
6a606e3c | 1168 | unsigned i, j, n; |
1169 | int is_latch = (latch == e->src); | |
1170 | int scale_act = 0, *scale_step = NULL, scale_main = 0; | |
7cef6c97 | 1171 | int scale_after_exit = 0; |
6a606e3c | 1172 | int p, freq_in, freq_le, freq_out_orig; |
1173 | int prob_pass_thru, prob_pass_wont_exit, prob_pass_main; | |
1174 | int add_irreducible_flag; | |
c4d867e0 | 1175 | basic_block place_after; |
7cef6c97 | 1176 | bitmap bbs_to_scale = NULL; |
1177 | bitmap_iterator bi; | |
6a606e3c | 1178 | |
cc636d56 | 1179 | gcc_assert (e->dest == loop->header); |
1180 | gcc_assert (ndupl > 0); | |
6a606e3c | 1181 | |
1182 | if (orig) | |
1183 | { | |
1184 | /* Orig must be edge out of the loop. */ | |
cc636d56 | 1185 | gcc_assert (flow_bb_inside_loop_p (loop, orig->src)); |
1186 | gcc_assert (!flow_bb_inside_loop_p (loop, orig->dest)); | |
6a606e3c | 1187 | } |
1188 | ||
c4d867e0 | 1189 | n = loop->num_nodes; |
1190 | bbs = get_loop_body_in_dom_order (loop); | |
1191 | gcc_assert (bbs[0] == loop->header); | |
1192 | gcc_assert (bbs[n - 1] == loop->latch); | |
6a606e3c | 1193 | |
1194 | /* Check whether duplication is possible. */ | |
dbfc1664 | 1195 | if (!can_copy_bbs_p (bbs, loop->num_nodes)) |
6a606e3c | 1196 | { |
dbfc1664 | 1197 | free (bbs); |
1198 | return false; | |
6a606e3c | 1199 | } |
4c36ffe6 | 1200 | new_bbs = XNEWVEC (basic_block, loop->num_nodes); |
6a606e3c | 1201 | |
dbfc1664 | 1202 | /* In case we are doing loop peeling and the loop is in the middle of |
1203 | irreducible region, the peeled copies will be inside it too. */ | |
1204 | add_irreducible_flag = e->flags & EDGE_IRREDUCIBLE_LOOP; | |
cc636d56 | 1205 | gcc_assert (!is_latch || !add_irreducible_flag); |
6a606e3c | 1206 | |
1207 | /* Find edge from latch. */ | |
1208 | latch_edge = loop_latch_edge (loop); | |
1209 | ||
1210 | if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
1211 | { | |
1212 | /* Calculate coefficients by that we have to scale frequencies | |
1213 | of duplicated loop bodies. */ | |
1214 | freq_in = header->frequency; | |
1215 | freq_le = EDGE_FREQUENCY (latch_edge); | |
1216 | if (freq_in == 0) | |
1217 | freq_in = 1; | |
1218 | if (freq_in < freq_le) | |
1219 | freq_in = freq_le; | |
1220 | freq_out_orig = orig ? EDGE_FREQUENCY (orig) : freq_in - freq_le; | |
1221 | if (freq_out_orig > freq_in - freq_le) | |
1222 | freq_out_orig = freq_in - freq_le; | |
1223 | prob_pass_thru = RDIV (REG_BR_PROB_BASE * freq_le, freq_in); | |
1224 | prob_pass_wont_exit = | |
1225 | RDIV (REG_BR_PROB_BASE * (freq_le + freq_out_orig), freq_in); | |
1226 | ||
7cef6c97 | 1227 | if (orig |
1228 | && REG_BR_PROB_BASE - orig->probability != 0) | |
1229 | { | |
1230 | /* The blocks that are dominated by a removed exit edge ORIG have | |
1231 | frequencies scaled by this. */ | |
f9d4b7f4 | 1232 | scale_after_exit |
1233 | = GCOV_COMPUTE_SCALE (REG_BR_PROB_BASE, | |
1234 | REG_BR_PROB_BASE - orig->probability); | |
7cef6c97 | 1235 | bbs_to_scale = BITMAP_ALLOC (NULL); |
1236 | for (i = 0; i < n; i++) | |
1237 | { | |
1238 | if (bbs[i] != orig->src | |
1239 | && dominated_by_p (CDI_DOMINATORS, bbs[i], orig->src)) | |
1240 | bitmap_set_bit (bbs_to_scale, i); | |
1241 | } | |
1242 | } | |
1243 | ||
4c36ffe6 | 1244 | scale_step = XNEWVEC (int, ndupl); |
6a606e3c | 1245 | |
7cef6c97 | 1246 | for (i = 1; i <= ndupl; i++) |
08b7917c | 1247 | scale_step[i - 1] = bitmap_bit_p (wont_exit, i) |
6a606e3c | 1248 | ? prob_pass_wont_exit |
1249 | : prob_pass_thru; | |
1250 | ||
3ce7ff97 | 1251 | /* Complete peeling is special as the probability of exit in last |
a0c938f0 | 1252 | copy becomes 1. */ |
fb54ef7c | 1253 | if (flags & DLTHE_FLAG_COMPLETTE_PEEL) |
1254 | { | |
1255 | int wanted_freq = EDGE_FREQUENCY (e); | |
1256 | ||
1257 | if (wanted_freq > freq_in) | |
1258 | wanted_freq = freq_in; | |
1259 | ||
1260 | gcc_assert (!is_latch); | |
3ce7ff97 | 1261 | /* First copy has frequency of incoming edge. Each subsequent |
fb54ef7c | 1262 | frequency should be reduced by prob_pass_wont_exit. Caller |
1263 | should've managed the flags so all except for original loop | |
1264 | has won't exist set. */ | |
f9d4b7f4 | 1265 | scale_act = GCOV_COMPUTE_SCALE (wanted_freq, freq_in); |
fb54ef7c | 1266 | /* Now simulate the duplication adjustments and compute header |
1267 | frequency of the last copy. */ | |
1268 | for (i = 0; i < ndupl; i++) | |
f9d4b7f4 | 1269 | wanted_freq = combine_probabilities (wanted_freq, scale_step[i]); |
1270 | scale_main = GCOV_COMPUTE_SCALE (wanted_freq, freq_in); | |
fb54ef7c | 1271 | } |
1272 | else if (is_latch) | |
6a606e3c | 1273 | { |
08b7917c | 1274 | prob_pass_main = bitmap_bit_p (wont_exit, 0) |
6a606e3c | 1275 | ? prob_pass_wont_exit |
1276 | : prob_pass_thru; | |
1277 | p = prob_pass_main; | |
1278 | scale_main = REG_BR_PROB_BASE; | |
1279 | for (i = 0; i < ndupl; i++) | |
1280 | { | |
1281 | scale_main += p; | |
f9d4b7f4 | 1282 | p = combine_probabilities (p, scale_step[i]); |
6a606e3c | 1283 | } |
f9d4b7f4 | 1284 | scale_main = GCOV_COMPUTE_SCALE (REG_BR_PROB_BASE, scale_main); |
1285 | scale_act = combine_probabilities (scale_main, prob_pass_main); | |
6a606e3c | 1286 | } |
1287 | else | |
1288 | { | |
305db1a8 | 1289 | int preheader_freq = EDGE_FREQUENCY (e); |
6a606e3c | 1290 | scale_main = REG_BR_PROB_BASE; |
1291 | for (i = 0; i < ndupl; i++) | |
f9d4b7f4 | 1292 | scale_main = combine_probabilities (scale_main, scale_step[i]); |
305db1a8 | 1293 | if (preheader_freq > freq_in) |
1294 | preheader_freq = freq_in; | |
1295 | scale_act = GCOV_COMPUTE_SCALE (preheader_freq, freq_in); | |
6a606e3c | 1296 | } |
1297 | for (i = 0; i < ndupl; i++) | |
cc636d56 | 1298 | gcc_assert (scale_step[i] >= 0 && scale_step[i] <= REG_BR_PROB_BASE); |
1299 | gcc_assert (scale_main >= 0 && scale_main <= REG_BR_PROB_BASE | |
1300 | && scale_act >= 0 && scale_act <= REG_BR_PROB_BASE); | |
6a606e3c | 1301 | } |
1302 | ||
1303 | /* Loop the new bbs will belong to. */ | |
dbfc1664 | 1304 | target = e->src->loop_father; |
6a606e3c | 1305 | |
1306 | /* Original loops. */ | |
1307 | n_orig_loops = 0; | |
1308 | for (aloop = loop->inner; aloop; aloop = aloop->next) | |
1309 | n_orig_loops++; | |
ed7e2206 | 1310 | orig_loops = XNEWVEC (struct loop *, n_orig_loops); |
6a606e3c | 1311 | for (aloop = loop->inner, i = 0; aloop; aloop = aloop->next, i++) |
1312 | orig_loops[i] = aloop; | |
1313 | ||
96c90e5e | 1314 | set_loop_copy (loop, target); |
4c9e08a4 | 1315 | |
4c36ffe6 | 1316 | first_active = XNEWVEC (basic_block, n); |
6a606e3c | 1317 | if (is_latch) |
1318 | { | |
1319 | memcpy (first_active, bbs, n * sizeof (basic_block)); | |
1320 | first_active_latch = latch; | |
1321 | } | |
1322 | ||
dbfc1664 | 1323 | spec_edges[SE_ORIG] = orig; |
1324 | spec_edges[SE_LATCH] = latch_edge; | |
4c9e08a4 | 1325 | |
c4d867e0 | 1326 | place_after = e->src; |
6a606e3c | 1327 | for (j = 0; j < ndupl; j++) |
1328 | { | |
1329 | /* Copy loops. */ | |
7194de72 | 1330 | copy_loops_to (orig_loops, n_orig_loops, target); |
6a606e3c | 1331 | |
1332 | /* Copy bbs. */ | |
c4d867e0 | 1333 | copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop, |
d99f53b2 | 1334 | place_after, true); |
c4d867e0 | 1335 | place_after = new_spec_edges[SE_LATCH]->src; |
dbfc1664 | 1336 | |
75cc36a4 | 1337 | if (flags & DLTHE_RECORD_COPY_NUMBER) |
1338 | for (i = 0; i < n; i++) | |
1339 | { | |
1340 | gcc_assert (!new_bbs[i]->aux); | |
1341 | new_bbs[i]->aux = (void *)(size_t)(j + 1); | |
1342 | } | |
a9989fb4 | 1343 | |
d493f913 | 1344 | /* Note whether the blocks and edges belong to an irreducible loop. */ |
1345 | if (add_irreducible_flag) | |
1346 | { | |
1347 | for (i = 0; i < n; i++) | |
01020a5f | 1348 | new_bbs[i]->flags |= BB_DUPLICATED; |
d493f913 | 1349 | for (i = 0; i < n; i++) |
1350 | { | |
cd665a06 | 1351 | edge_iterator ei; |
d493f913 | 1352 | new_bb = new_bbs[i]; |
1353 | if (new_bb->loop_father == target) | |
1354 | new_bb->flags |= BB_IRREDUCIBLE_LOOP; | |
1355 | ||
cd665a06 | 1356 | FOR_EACH_EDGE (ae, ei, new_bb->succs) |
01020a5f | 1357 | if ((ae->dest->flags & BB_DUPLICATED) |
d493f913 | 1358 | && (ae->src->loop_father == target |
1359 | || ae->dest->loop_father == target)) | |
1360 | ae->flags |= EDGE_IRREDUCIBLE_LOOP; | |
1361 | } | |
1362 | for (i = 0; i < n; i++) | |
01020a5f | 1363 | new_bbs[i]->flags &= ~BB_DUPLICATED; |
d493f913 | 1364 | } |
1365 | ||
dbfc1664 | 1366 | /* Redirect the special edges. */ |
6a606e3c | 1367 | if (is_latch) |
dbfc1664 | 1368 | { |
1369 | redirect_edge_and_branch_force (latch_edge, new_bbs[0]); | |
1370 | redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
1371 | loop->header); | |
0051c76a | 1372 | set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], latch); |
c4d867e0 | 1373 | latch = loop->latch = new_bbs[n - 1]; |
dbfc1664 | 1374 | e = latch_edge = new_spec_edges[SE_LATCH]; |
1375 | } | |
1376 | else | |
1377 | { | |
1378 | redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
1379 | loop->header); | |
1380 | redirect_edge_and_branch_force (e, new_bbs[0]); | |
0051c76a | 1381 | set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], e->src); |
dbfc1664 | 1382 | e = new_spec_edges[SE_LATCH]; |
1383 | } | |
6a606e3c | 1384 | |
dbfc1664 | 1385 | /* Record exit edge in this copy. */ |
08b7917c | 1386 | if (orig && bitmap_bit_p (wont_exit, j + 1)) |
f3c40e6d | 1387 | { |
1388 | if (to_remove) | |
f1f41a6c | 1389 | to_remove->safe_push (new_spec_edges[SE_ORIG]); |
7cef6c97 | 1390 | set_zero_probability (new_spec_edges[SE_ORIG]); |
1391 | ||
1392 | /* Scale the frequencies of the blocks dominated by the exit. */ | |
1393 | if (bbs_to_scale) | |
1394 | { | |
1395 | EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
1396 | { | |
1397 | scale_bbs_frequencies_int (new_bbs + i, 1, scale_after_exit, | |
1398 | REG_BR_PROB_BASE); | |
1399 | } | |
1400 | } | |
f3c40e6d | 1401 | } |
4c9e08a4 | 1402 | |
dbfc1664 | 1403 | /* Record the first copy in the control flow order if it is not |
1404 | the original loop (i.e. in case of peeling). */ | |
6a606e3c | 1405 | if (!first_active_latch) |
1406 | { | |
1407 | memcpy (first_active, new_bbs, n * sizeof (basic_block)); | |
c4d867e0 | 1408 | first_active_latch = new_bbs[n - 1]; |
6a606e3c | 1409 | } |
4c9e08a4 | 1410 | |
dbfc1664 | 1411 | /* Set counts and frequencies. */ |
1412 | if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
6a606e3c | 1413 | { |
4d6b11ab | 1414 | scale_bbs_frequencies_int (new_bbs, n, scale_act, REG_BR_PROB_BASE); |
f9d4b7f4 | 1415 | scale_act = combine_probabilities (scale_act, scale_step[j]); |
6a606e3c | 1416 | } |
1417 | } | |
dbfc1664 | 1418 | free (new_bbs); |
1419 | free (orig_loops); | |
a0c938f0 | 1420 | |
f3c40e6d | 1421 | /* Record the exit edge in the original loop body, and update the frequencies. */ |
08b7917c | 1422 | if (orig && bitmap_bit_p (wont_exit, 0)) |
f3c40e6d | 1423 | { |
1424 | if (to_remove) | |
f1f41a6c | 1425 | to_remove->safe_push (orig); |
7cef6c97 | 1426 | set_zero_probability (orig); |
1427 | ||
1428 | /* Scale the frequencies of the blocks dominated by the exit. */ | |
1429 | if (bbs_to_scale) | |
1430 | { | |
1431 | EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
1432 | { | |
1433 | scale_bbs_frequencies_int (bbs + i, 1, scale_after_exit, | |
1434 | REG_BR_PROB_BASE); | |
1435 | } | |
1436 | } | |
f3c40e6d | 1437 | } |
1438 | ||
dbfc1664 | 1439 | /* Update the original loop. */ |
1440 | if (!is_latch) | |
0051c76a | 1441 | set_immediate_dominator (CDI_DOMINATORS, e->dest, e->src); |
6a606e3c | 1442 | if (flags & DLTHE_FLAG_UPDATE_FREQ) |
1443 | { | |
4d6b11ab | 1444 | scale_bbs_frequencies_int (bbs, n, scale_main, REG_BR_PROB_BASE); |
6a606e3c | 1445 | free (scale_step); |
1446 | } | |
6a606e3c | 1447 | |
dbfc1664 | 1448 | /* Update dominators of outer blocks if affected. */ |
6a606e3c | 1449 | for (i = 0; i < n; i++) |
1450 | { | |
3f9439d7 | 1451 | basic_block dominated, dom_bb; |
f1f41a6c | 1452 | vec<basic_block> dom_bbs; |
3f9439d7 | 1453 | unsigned j; |
6a606e3c | 1454 | |
1455 | bb = bbs[i]; | |
01020a5f | 1456 | bb->aux = 0; |
a9989fb4 | 1457 | |
3f9439d7 | 1458 | dom_bbs = get_dominated_by (CDI_DOMINATORS, bb); |
f1f41a6c | 1459 | FOR_EACH_VEC_ELT (dom_bbs, j, dominated) |
6a606e3c | 1460 | { |
6a606e3c | 1461 | if (flow_bb_inside_loop_p (loop, dominated)) |
1462 | continue; | |
1463 | dom_bb = nearest_common_dominator ( | |
0051c76a | 1464 | CDI_DOMINATORS, first_active[i], first_active_latch); |
a0c938f0 | 1465 | set_immediate_dominator (CDI_DOMINATORS, dominated, dom_bb); |
6a606e3c | 1466 | } |
f1f41a6c | 1467 | dom_bbs.release (); |
6a606e3c | 1468 | } |
1469 | free (first_active); | |
1470 | ||
1471 | free (bbs); | |
7cef6c97 | 1472 | BITMAP_FREE (bbs_to_scale); |
6a606e3c | 1473 | |
1474 | return true; | |
1475 | } | |
1476 | ||
5f5d4cd1 | 1477 | /* A callback for make_forwarder block, to redirect all edges except for |
1478 | MFB_KJ_EDGE to the entry part. E is the edge for that we should decide | |
1479 | whether to redirect it. */ | |
1480 | ||
7e0311ae | 1481 | edge mfb_kj_edge; |
1482 | bool | |
5f5d4cd1 | 1483 | mfb_keep_just (edge e) |
1484 | { | |
1485 | return e != mfb_kj_edge; | |
1486 | } | |
1487 | ||
e1ab7874 | 1488 | /* True when a candidate preheader BLOCK has predecessors from LOOP. */ |
1489 | ||
1490 | static bool | |
1491 | has_preds_from_loop (basic_block block, struct loop *loop) | |
1492 | { | |
1493 | edge e; | |
1494 | edge_iterator ei; | |
48e1416a | 1495 | |
e1ab7874 | 1496 | FOR_EACH_EDGE (e, ei, block->preds) |
1497 | if (e->src->loop_father == loop) | |
1498 | return true; | |
1499 | return false; | |
1500 | } | |
1501 | ||
862be747 | 1502 | /* Creates a pre-header for a LOOP. Returns newly created block. Unless |
1503 | CP_SIMPLE_PREHEADERS is set in FLAGS, we only force LOOP to have single | |
1504 | entry; otherwise we also force preheader block to have only one successor. | |
e1ab7874 | 1505 | When CP_FALLTHRU_PREHEADERS is set in FLAGS, we force the preheader block |
48e1416a | 1506 | to be a fallthru predecessor to the loop header and to have only |
e1ab7874 | 1507 | predecessors from outside of the loop. |
5f5d4cd1 | 1508 | The function also updates dominators. */ |
1509 | ||
7e0311ae | 1510 | basic_block |
0051c76a | 1511 | create_preheader (struct loop *loop, int flags) |
862be747 | 1512 | { |
ec969ce4 | 1513 | edge e; |
862be747 | 1514 | basic_block dummy; |
862be747 | 1515 | int nentry = 0; |
5f5d4cd1 | 1516 | bool irred = false; |
478166d0 | 1517 | bool latch_edge_was_fallthru; |
d8a0d6b8 | 1518 | edge one_succ_pred = NULL, single_entry = NULL; |
cd665a06 | 1519 | edge_iterator ei; |
862be747 | 1520 | |
cd665a06 | 1521 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
862be747 | 1522 | { |
1523 | if (e->src == loop->latch) | |
1524 | continue; | |
5f5d4cd1 | 1525 | irred |= (e->flags & EDGE_IRREDUCIBLE_LOOP) != 0; |
862be747 | 1526 | nentry++; |
d8a0d6b8 | 1527 | single_entry = e; |
ea091dfd | 1528 | if (single_succ_p (e->src)) |
478166d0 | 1529 | one_succ_pred = e; |
862be747 | 1530 | } |
cc636d56 | 1531 | gcc_assert (nentry); |
862be747 | 1532 | if (nentry == 1) |
1533 | { | |
e1ab7874 | 1534 | bool need_forwarder_block = false; |
48e1416a | 1535 | |
e1ab7874 | 1536 | /* We do not allow entry block to be the loop preheader, since we |
4a6f9e19 | 1537 | cannot emit code there. */ |
34154e27 | 1538 | if (single_entry->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
e1ab7874 | 1539 | need_forwarder_block = true; |
1540 | else | |
1541 | { | |
1542 | /* If we want simple preheaders, also force the preheader to have | |
1543 | just a single successor. */ | |
1544 | if ((flags & CP_SIMPLE_PREHEADERS) | |
1545 | && !single_succ_p (single_entry->src)) | |
1546 | need_forwarder_block = true; | |
1547 | /* If we want fallthru preheaders, also create forwarder block when | |
1548 | preheader ends with a jump or has predecessors from loop. */ | |
1549 | else if ((flags & CP_FALLTHRU_PREHEADERS) | |
1550 | && (JUMP_P (BB_END (single_entry->src)) | |
1551 | || has_preds_from_loop (single_entry->src, loop))) | |
1552 | need_forwarder_block = true; | |
1553 | } | |
1554 | if (! need_forwarder_block) | |
862be747 | 1555 | return NULL; |
1556 | } | |
1557 | ||
5f5d4cd1 | 1558 | mfb_kj_edge = loop_latch_edge (loop); |
478166d0 | 1559 | latch_edge_was_fallthru = (mfb_kj_edge->flags & EDGE_FALLTHRU) != 0; |
ec969ce4 | 1560 | if (nentry == 1) |
1561 | dummy = split_edge (single_entry); | |
1562 | else | |
1563 | { | |
1564 | edge fallthru = make_forwarder_block (loop->header, mfb_keep_just, NULL); | |
1565 | dummy = fallthru->src; | |
1566 | loop->header = fallthru->dest; | |
1567 | } | |
862be747 | 1568 | |
478166d0 | 1569 | /* Try to be clever in placing the newly created preheader. The idea is to |
1570 | avoid breaking any "fallthruness" relationship between blocks. | |
1571 | ||
1572 | The preheader was created just before the header and all incoming edges | |
1573 | to the header were redirected to the preheader, except the latch edge. | |
1574 | So the only problematic case is when this latch edge was a fallthru | |
1575 | edge: it is not anymore after the preheader creation so we have broken | |
1576 | the fallthruness. We're therefore going to look for a better place. */ | |
1577 | if (latch_edge_was_fallthru) | |
1578 | { | |
1579 | if (one_succ_pred) | |
1580 | e = one_succ_pred; | |
1581 | else | |
1582 | e = EDGE_PRED (dummy, 0); | |
1583 | ||
1584 | move_block_after (dummy, e->src); | |
1585 | } | |
5f5d4cd1 | 1586 | |
5f5d4cd1 | 1587 | if (irred) |
862be747 | 1588 | { |
5f5d4cd1 | 1589 | dummy->flags |= BB_IRREDUCIBLE_LOOP; |
ea091dfd | 1590 | single_succ_edge (dummy)->flags |= EDGE_IRREDUCIBLE_LOOP; |
862be747 | 1591 | } |
1592 | ||
450d042a | 1593 | if (dump_file) |
1594 | fprintf (dump_file, "Created preheader block for loop %i\n", | |
862be747 | 1595 | loop->num); |
48e1416a | 1596 | |
e1ab7874 | 1597 | if (flags & CP_FALLTHRU_PREHEADERS) |
1598 | gcc_assert ((single_succ_edge (dummy)->flags & EDGE_FALLTHRU) | |
1599 | && !JUMP_P (BB_END (dummy))); | |
862be747 | 1600 | |
1601 | return dummy; | |
1602 | } | |
1603 | ||
7194de72 | 1604 | /* Create preheaders for each loop; for meaning of FLAGS see create_preheader. */ |
1605 | ||
862be747 | 1606 | void |
7194de72 | 1607 | create_preheaders (int flags) |
862be747 | 1608 | { |
17519ba0 | 1609 | struct loop *loop; |
1610 | ||
d8a0d6b8 | 1611 | if (!current_loops) |
1612 | return; | |
1613 | ||
f21d4d00 | 1614 | FOR_EACH_LOOP (loop, 0) |
17519ba0 | 1615 | create_preheader (loop, flags); |
f24ec26f | 1616 | loops_state_set (LOOPS_HAVE_PREHEADERS); |
862be747 | 1617 | } |
1618 | ||
7194de72 | 1619 | /* Forces all loop latches to have only single successor. */ |
1620 | ||
862be747 | 1621 | void |
7194de72 | 1622 | force_single_succ_latches (void) |
862be747 | 1623 | { |
862be747 | 1624 | struct loop *loop; |
1625 | edge e; | |
1626 | ||
f21d4d00 | 1627 | FOR_EACH_LOOP (loop, 0) |
862be747 | 1628 | { |
ea091dfd | 1629 | if (loop->latch != loop->header && single_succ_p (loop->latch)) |
862be747 | 1630 | continue; |
4c9e08a4 | 1631 | |
c6356c17 | 1632 | e = find_edge (loop->latch, loop->header); |
8ca4cf5b | 1633 | gcc_checking_assert (e != NULL); |
b536af40 | 1634 | |
88e6f696 | 1635 | split_edge (e); |
862be747 | 1636 | } |
f24ec26f | 1637 | loops_state_set (LOOPS_HAVE_SIMPLE_LATCHES); |
862be747 | 1638 | } |
1639 | ||
c50ae675 | 1640 | /* This function is called from loop_version. It splits the entry edge |
1641 | of the loop we want to version, adds the versioning condition, and | |
1642 | adjust the edges to the two versions of the loop appropriately. | |
1643 | e is an incoming edge. Returns the basic block containing the | |
1644 | condition. | |
1645 | ||
1646 | --- edge e ---- > [second_head] | |
1647 | ||
1648 | Split it and insert new conditional expression and adjust edges. | |
1649 | ||
1650 | --- edge e ---> [cond expr] ---> [first_head] | |
a0c938f0 | 1651 | | |
1652 | +---------> [second_head] | |
7cef6c97 | 1653 | |
b6863ffa | 1654 | THEN_PROB is the probability of then branch of the condition. |
1655 | ELSE_PROB is the probability of else branch. Note that they may be both | |
1656 | REG_BR_PROB_BASE when condition is IFN_LOOP_VECTORIZED. */ | |
c50ae675 | 1657 | |
1658 | static basic_block | |
7cef6c97 | 1659 | lv_adjust_loop_entry_edge (basic_block first_head, basic_block second_head, |
b6863ffa | 1660 | edge e, void *cond_expr, unsigned then_prob, |
1661 | unsigned else_prob) | |
c50ae675 | 1662 | { |
1663 | basic_block new_head = NULL; | |
1664 | edge e1; | |
1665 | ||
1666 | gcc_assert (e->dest == second_head); | |
1667 | ||
1668 | /* Split edge 'e'. This will create a new basic block, where we can | |
1669 | insert conditional expr. */ | |
1670 | new_head = split_edge (e); | |
1671 | ||
c50ae675 | 1672 | lv_add_condition_to_bb (first_head, second_head, new_head, |
1673 | cond_expr); | |
1674 | ||
ed49ee5b | 1675 | /* Don't set EDGE_TRUE_VALUE in RTL mode, as it's invalid there. */ |
7cef6c97 | 1676 | e = single_succ_edge (new_head); |
15b8fe07 | 1677 | e1 = make_edge (new_head, first_head, |
1678 | current_ir_type () == IR_GIMPLE ? EDGE_TRUE_VALUE : 0); | |
7cef6c97 | 1679 | e1->probability = then_prob; |
b6863ffa | 1680 | e->probability = else_prob; |
db9cef39 | 1681 | e1->count = e->count.apply_probability (e1->probability); |
1682 | e->count = e->count.apply_probability (e->probability); | |
7cef6c97 | 1683 | |
c50ae675 | 1684 | set_immediate_dominator (CDI_DOMINATORS, first_head, new_head); |
1685 | set_immediate_dominator (CDI_DOMINATORS, second_head, new_head); | |
1686 | ||
1687 | /* Adjust loop header phi nodes. */ | |
1688 | lv_adjust_loop_header_phi (first_head, second_head, new_head, e1); | |
1689 | ||
1690 | return new_head; | |
1691 | } | |
1692 | ||
1693 | /* Main entry point for Loop Versioning transformation. | |
a0c938f0 | 1694 | |
c4d867e0 | 1695 | This transformation given a condition and a loop, creates |
1696 | -if (condition) { loop_copy1 } else { loop_copy2 }, | |
1697 | where loop_copy1 is the loop transformed in one way, and loop_copy2 | |
d249e327 | 1698 | is the loop transformed in another way (or unchanged). COND_EXPR |
c4d867e0 | 1699 | may be a run time test for things that were not resolved by static |
1700 | analysis (overlapping ranges (anti-aliasing), alignment, etc.). | |
1701 | ||
d249e327 | 1702 | If non-NULL, CONDITION_BB is set to the basic block containing the |
1703 | condition. | |
1704 | ||
7cef6c97 | 1705 | THEN_PROB is the probability of the then edge of the if. THEN_SCALE |
1706 | is the ratio by that the frequencies in the original loop should | |
1707 | be scaled. ELSE_SCALE is the ratio by that the frequencies in the | |
1708 | new loop should be scaled. | |
48e1416a | 1709 | |
c4d867e0 | 1710 | If PLACE_AFTER is true, we place the new loop after LOOP in the |
1711 | instruction stream, otherwise it is placed before LOOP. */ | |
c50ae675 | 1712 | |
1713 | struct loop * | |
7194de72 | 1714 | loop_version (struct loop *loop, |
c4d867e0 | 1715 | void *cond_expr, basic_block *condition_bb, |
b6863ffa | 1716 | unsigned then_prob, unsigned else_prob, |
1717 | unsigned then_scale, unsigned else_scale, | |
c4d867e0 | 1718 | bool place_after) |
c50ae675 | 1719 | { |
1720 | basic_block first_head, second_head; | |
dce58e66 | 1721 | edge entry, latch_edge, true_edge, false_edge; |
c50ae675 | 1722 | int irred_flag; |
1723 | struct loop *nloop; | |
c4d867e0 | 1724 | basic_block cond_bb; |
c50ae675 | 1725 | |
c50ae675 | 1726 | /* Record entry and latch edges for the loop */ |
1727 | entry = loop_preheader_edge (loop); | |
1728 | irred_flag = entry->flags & EDGE_IRREDUCIBLE_LOOP; | |
1729 | entry->flags &= ~EDGE_IRREDUCIBLE_LOOP; | |
a0c938f0 | 1730 | |
c50ae675 | 1731 | /* Note down head of loop as first_head. */ |
1732 | first_head = entry->dest; | |
1733 | ||
1734 | /* Duplicate loop. */ | |
7194de72 | 1735 | if (!cfg_hook_duplicate_loop_to_header_edge (loop, entry, 1, |
f3c40e6d | 1736 | NULL, NULL, NULL, 0)) |
48b6dfd8 | 1737 | { |
1738 | entry->flags |= irred_flag; | |
1739 | return NULL; | |
1740 | } | |
c50ae675 | 1741 | |
1742 | /* After duplication entry edge now points to new loop head block. | |
1743 | Note down new head as second_head. */ | |
1744 | second_head = entry->dest; | |
1745 | ||
1746 | /* Split loop entry edge and insert new block with cond expr. */ | |
c4d867e0 | 1747 | cond_bb = lv_adjust_loop_entry_edge (first_head, second_head, |
b6863ffa | 1748 | entry, cond_expr, then_prob, else_prob); |
c4d867e0 | 1749 | if (condition_bb) |
1750 | *condition_bb = cond_bb; | |
1751 | ||
1752 | if (!cond_bb) | |
c50ae675 | 1753 | { |
1754 | entry->flags |= irred_flag; | |
1755 | return NULL; | |
1756 | } | |
1757 | ||
01020a5f | 1758 | latch_edge = single_succ_edge (get_bb_copy (loop->latch)); |
a0c938f0 | 1759 | |
c4d867e0 | 1760 | extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); |
7194de72 | 1761 | nloop = loopify (latch_edge, |
01020a5f | 1762 | single_pred_edge (get_bb_copy (loop->header)), |
c4d867e0 | 1763 | cond_bb, true_edge, false_edge, |
7cef6c97 | 1764 | false /* Do not redirect all edges. */, |
1765 | then_scale, else_scale); | |
c50ae675 | 1766 | |
efa7c5bd | 1767 | copy_loop_info (loop, nloop); |
1768 | ||
a0c938f0 | 1769 | /* loopify redirected latch_edge. Update its PENDING_STMTS. */ |
c50ae675 | 1770 | lv_flush_pending_stmts (latch_edge); |
1771 | ||
a0c938f0 | 1772 | /* loopify redirected condition_bb's succ edge. Update its PENDING_STMTS. */ |
c4d867e0 | 1773 | extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); |
c50ae675 | 1774 | lv_flush_pending_stmts (false_edge); |
1775 | /* Adjust irreducible flag. */ | |
1776 | if (irred_flag) | |
1777 | { | |
c4d867e0 | 1778 | cond_bb->flags |= BB_IRREDUCIBLE_LOOP; |
c50ae675 | 1779 | loop_preheader_edge (loop)->flags |= EDGE_IRREDUCIBLE_LOOP; |
1780 | loop_preheader_edge (nloop)->flags |= EDGE_IRREDUCIBLE_LOOP; | |
c4d867e0 | 1781 | single_pred_edge (cond_bb)->flags |= EDGE_IRREDUCIBLE_LOOP; |
1782 | } | |
1783 | ||
1784 | if (place_after) | |
1785 | { | |
1786 | basic_block *bbs = get_loop_body_in_dom_order (nloop), after; | |
1787 | unsigned i; | |
1788 | ||
1789 | after = loop->latch; | |
1790 | ||
1791 | for (i = 0; i < nloop->num_nodes; i++) | |
1792 | { | |
1793 | move_block_after (bbs[i], after); | |
1794 | after = bbs[i]; | |
1795 | } | |
1796 | free (bbs); | |
c50ae675 | 1797 | } |
1798 | ||
f0b5f617 | 1799 | /* At this point condition_bb is loop preheader with two successors, |
1800 | first_head and second_head. Make sure that loop preheader has only | |
c50ae675 | 1801 | one successor. */ |
88e6f696 | 1802 | split_edge (loop_preheader_edge (loop)); |
1803 | split_edge (loop_preheader_edge (nloop)); | |
c50ae675 | 1804 | |
1805 | return nloop; | |
1806 | } |