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862be747 | 1 | /* Loop manipulation code for GNU compiler. |
711789cc | 2 | Copyright (C) 2002-2013 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" | |
23 | #include "tm.h" | |
24 | #include "rtl.h" | |
862be747 | 25 | #include "basic-block.h" |
26 | #include "cfgloop.h" | |
41a8aa41 | 27 | #include "tree.h" |
bc61cadb | 28 | #include "tree-ssa-alias.h" |
29 | #include "internal-fn.h" | |
30 | #include "gimple-expr.h" | |
31 | #include "is-a.h" | |
e795d6e1 | 32 | #include "gimple.h" |
dcf1a1ec | 33 | #include "gimple-iterator.h" |
e795d6e1 | 34 | #include "gimplify-me.h" |
05d9c18a | 35 | #include "tree-ssa-loop-manip.h" |
b9ed1410 | 36 | #include "dumpfile.h" |
862be747 | 37 | |
7194de72 | 38 | static void copy_loops_to (struct loop **, int, |
4c9e08a4 | 39 | struct loop *); |
40 | static void loop_redirect_edge (edge, basic_block); | |
0051c76a | 41 | static void remove_bbs (basic_block *, int); |
7ecb5bb2 | 42 | static bool rpe_enum_p (const_basic_block, const void *); |
0051c76a | 43 | static int find_path (edge, basic_block **); |
7194de72 | 44 | static void fix_loop_placements (struct loop *, bool *); |
45 | static bool fix_bb_placement (basic_block); | |
9f0ac045 | 46 | static void fix_bb_placements (basic_block, bool *, bitmap); |
862be747 | 47 | |
0051c76a | 48 | /* Checks whether basic block BB is dominated by DATA. */ |
6a606e3c | 49 | static bool |
7ecb5bb2 | 50 | rpe_enum_p (const_basic_block bb, const void *data) |
6a606e3c | 51 | { |
7ecb5bb2 | 52 | return dominated_by_p (CDI_DOMINATORS, bb, (const_basic_block) data); |
6a606e3c | 53 | } |
54 | ||
88e6f696 | 55 | /* Remove basic blocks BBS. NBBS is the number of the basic blocks. */ |
56 | ||
6a606e3c | 57 | static void |
0051c76a | 58 | remove_bbs (basic_block *bbs, int nbbs) |
6a606e3c | 59 | { |
60 | int i; | |
61 | ||
62 | for (i = 0; i < nbbs; i++) | |
88e6f696 | 63 | delete_basic_block (bbs[i]); |
6a606e3c | 64 | } |
65 | ||
66 | /* Find path -- i.e. the basic blocks dominated by edge E and put them | |
67 | into array BBS, that will be allocated large enough to contain them. | |
a5414ff5 | 68 | E->dest must have exactly one predecessor for this to work (it is |
69 | easy to achieve and we do not put it here because we do not want to | |
70 | alter anything by this function). The number of basic blocks in the | |
71 | path is returned. */ | |
6a606e3c | 72 | static int |
0051c76a | 73 | find_path (edge e, basic_block **bbs) |
6a606e3c | 74 | { |
cd665a06 | 75 | gcc_assert (EDGE_COUNT (e->dest->preds) <= 1); |
6a606e3c | 76 | |
77 | /* Find bbs in the path. */ | |
a28770e1 | 78 | *bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
6a606e3c | 79 | return dfs_enumerate_from (e->dest, 0, rpe_enum_p, *bbs, |
a28770e1 | 80 | n_basic_blocks_for_fn (cfun), e->dest); |
6a606e3c | 81 | } |
82 | ||
7194de72 | 83 | /* Fix placement of basic block BB inside loop hierarchy -- |
6a606e3c | 84 | Let L be a loop to that BB belongs. Then every successor of BB must either |
85 | 1) belong to some superloop of loop L, or | |
86 | 2) be a header of loop K such that K->outer is superloop of L | |
87 | Returns true if we had to move BB into other loop to enforce this condition, | |
88 | false if the placement of BB was already correct (provided that placements | |
89 | of its successors are correct). */ | |
90 | static bool | |
7194de72 | 91 | fix_bb_placement (basic_block bb) |
6a606e3c | 92 | { |
93 | edge e; | |
cd665a06 | 94 | edge_iterator ei; |
7194de72 | 95 | struct loop *loop = current_loops->tree_root, *act; |
6a606e3c | 96 | |
cd665a06 | 97 | FOR_EACH_EDGE (e, ei, bb->succs) |
6a606e3c | 98 | { |
34154e27 | 99 | if (e->dest == EXIT_BLOCK_PTR_FOR_FN (cfun)) |
6a606e3c | 100 | continue; |
101 | ||
102 | act = e->dest->loop_father; | |
103 | if (act->header == e->dest) | |
9e3536f4 | 104 | act = loop_outer (act); |
6a606e3c | 105 | |
106 | if (flow_loop_nested_p (loop, act)) | |
107 | loop = act; | |
108 | } | |
109 | ||
110 | if (loop == bb->loop_father) | |
111 | return false; | |
112 | ||
113 | remove_bb_from_loops (bb); | |
114 | add_bb_to_loop (bb, loop); | |
115 | ||
116 | return true; | |
117 | } | |
118 | ||
99b6a86e | 119 | /* Fix placement of LOOP inside loop tree, i.e. find the innermost superloop |
120 | of LOOP to that leads at least one exit edge of LOOP, and set it | |
121 | as the immediate superloop of LOOP. Return true if the immediate superloop | |
c1f96968 | 122 | of LOOP changed. |
123 | ||
124 | IRRED_INVALIDATED is set to true if a change in the loop structures might | |
125 | invalidate the information about irreducible regions. */ | |
99b6a86e | 126 | |
127 | static bool | |
c1f96968 | 128 | fix_loop_placement (struct loop *loop, bool *irred_invalidated) |
99b6a86e | 129 | { |
130 | unsigned i; | |
131 | edge e; | |
f1f41a6c | 132 | vec<edge> exits = get_loop_exit_edges (loop); |
99b6a86e | 133 | struct loop *father = current_loops->tree_root, *act; |
134 | bool ret = false; | |
135 | ||
f1f41a6c | 136 | FOR_EACH_VEC_ELT (exits, i, e) |
99b6a86e | 137 | { |
138 | act = find_common_loop (loop, e->dest->loop_father); | |
139 | if (flow_loop_nested_p (father, act)) | |
140 | father = act; | |
141 | } | |
142 | ||
9e3536f4 | 143 | if (father != loop_outer (loop)) |
99b6a86e | 144 | { |
9e3536f4 | 145 | for (act = loop_outer (loop); act != father; act = loop_outer (act)) |
99b6a86e | 146 | act->num_nodes -= loop->num_nodes; |
147 | flow_loop_tree_node_remove (loop); | |
148 | flow_loop_tree_node_add (father, loop); | |
149 | ||
150 | /* The exit edges of LOOP no longer exits its original immediate | |
151 | superloops; remove them from the appropriate exit lists. */ | |
f1f41a6c | 152 | FOR_EACH_VEC_ELT (exits, i, e) |
c1f96968 | 153 | { |
154 | /* We may need to recompute irreducible loops. */ | |
155 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
156 | *irred_invalidated = true; | |
157 | rescan_loop_exit (e, false, false); | |
158 | } | |
99b6a86e | 159 | |
160 | ret = true; | |
161 | } | |
162 | ||
f1f41a6c | 163 | exits.release (); |
99b6a86e | 164 | return ret; |
165 | } | |
166 | ||
6a606e3c | 167 | /* Fix placements of basic blocks inside loop hierarchy stored in loops; i.e. |
168 | enforce condition condition stated in description of fix_bb_placement. We | |
169 | start from basic block FROM that had some of its successors removed, so that | |
170 | his placement no longer has to be correct, and iteratively fix placement of | |
171 | its predecessors that may change if placement of FROM changed. Also fix | |
172 | placement of subloops of FROM->loop_father, that might also be altered due | |
917bbcab | 173 | to this change; the condition for them is similar, except that instead of |
afd8eb66 | 174 | successors we consider edges coming out of the loops. |
48e1416a | 175 | |
afd8eb66 | 176 | If the changes may invalidate the information about irreducible regions, |
9f0ac045 | 177 | IRRED_INVALIDATED is set to true. |
178 | ||
179 | If LOOP_CLOSED_SSA_INVLIDATED is non-zero then all basic blocks with | |
180 | changed loop_father are collected there. */ | |
afd8eb66 | 181 | |
6a606e3c | 182 | static void |
7194de72 | 183 | fix_bb_placements (basic_block from, |
9f0ac045 | 184 | bool *irred_invalidated, |
185 | bitmap loop_closed_ssa_invalidated) | |
6a606e3c | 186 | { |
187 | sbitmap in_queue; | |
188 | basic_block *queue, *qtop, *qbeg, *qend; | |
6e05e600 | 189 | struct loop *base_loop, *target_loop; |
6a606e3c | 190 | edge e; |
191 | ||
192 | /* We pass through blocks back-reachable from FROM, testing whether some | |
193 | of their successors moved to outer loop. It may be necessary to | |
194 | iterate several times, but it is finite, as we stop unless we move | |
195 | the basic block up the loop structure. The whole story is a bit | |
196 | more complicated due to presence of subloops, those are moved using | |
197 | fix_loop_placement. */ | |
198 | ||
199 | base_loop = from->loop_father; | |
68fb4bc0 | 200 | /* If we are already in the outermost loop, the basic blocks cannot be moved |
201 | outside of it. If FROM is the header of the base loop, it cannot be moved | |
202 | outside of it, either. In both cases, we can end now. */ | |
203 | if (base_loop == current_loops->tree_root | |
204 | || from == base_loop->header) | |
6a606e3c | 205 | return; |
206 | ||
fe672ac0 | 207 | in_queue = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 208 | bitmap_clear (in_queue); |
08b7917c | 209 | bitmap_set_bit (in_queue, from->index); |
6a606e3c | 210 | /* Prevent us from going out of the base_loop. */ |
08b7917c | 211 | bitmap_set_bit (in_queue, base_loop->header->index); |
6a606e3c | 212 | |
4c36ffe6 | 213 | queue = XNEWVEC (basic_block, base_loop->num_nodes + 1); |
6a606e3c | 214 | qtop = queue + base_loop->num_nodes + 1; |
215 | qbeg = queue; | |
216 | qend = queue + 1; | |
217 | *qbeg = from; | |
218 | ||
219 | while (qbeg != qend) | |
220 | { | |
cd665a06 | 221 | edge_iterator ei; |
6a606e3c | 222 | from = *qbeg; |
223 | qbeg++; | |
224 | if (qbeg == qtop) | |
225 | qbeg = queue; | |
08b7917c | 226 | bitmap_clear_bit (in_queue, from->index); |
6a606e3c | 227 | |
228 | if (from->loop_father->header == from) | |
229 | { | |
230 | /* Subloop header, maybe move the loop upward. */ | |
c1f96968 | 231 | if (!fix_loop_placement (from->loop_father, irred_invalidated)) |
6a606e3c | 232 | continue; |
6e05e600 | 233 | target_loop = loop_outer (from->loop_father); |
9cad916b | 234 | if (loop_closed_ssa_invalidated) |
235 | { | |
236 | basic_block *bbs = get_loop_body (from->loop_father); | |
237 | for (unsigned i = 0; i < from->loop_father->num_nodes; ++i) | |
238 | bitmap_set_bit (loop_closed_ssa_invalidated, bbs[i]->index); | |
239 | free (bbs); | |
240 | } | |
6a606e3c | 241 | } |
242 | else | |
243 | { | |
244 | /* Ordinary basic block. */ | |
7194de72 | 245 | if (!fix_bb_placement (from)) |
6a606e3c | 246 | continue; |
9cad916b | 247 | target_loop = from->loop_father; |
9f0ac045 | 248 | if (loop_closed_ssa_invalidated) |
249 | bitmap_set_bit (loop_closed_ssa_invalidated, from->index); | |
6a606e3c | 250 | } |
251 | ||
afd8eb66 | 252 | FOR_EACH_EDGE (e, ei, from->succs) |
253 | { | |
254 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
255 | *irred_invalidated = true; | |
256 | } | |
257 | ||
6a606e3c | 258 | /* Something has changed, insert predecessors into queue. */ |
cd665a06 | 259 | FOR_EACH_EDGE (e, ei, from->preds) |
6a606e3c | 260 | { |
261 | basic_block pred = e->src; | |
262 | struct loop *nca; | |
263 | ||
afd8eb66 | 264 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) |
265 | *irred_invalidated = true; | |
266 | ||
08b7917c | 267 | if (bitmap_bit_p (in_queue, pred->index)) |
6a606e3c | 268 | continue; |
269 | ||
4c9e08a4 | 270 | /* If it is subloop, then it either was not moved, or |
6a606e3c | 271 | the path up the loop tree from base_loop do not contain |
272 | it. */ | |
273 | nca = find_common_loop (pred->loop_father, base_loop); | |
274 | if (pred->loop_father != base_loop | |
275 | && (nca == base_loop | |
276 | || nca != pred->loop_father)) | |
277 | pred = pred->loop_father->header; | |
6e05e600 | 278 | else if (!flow_loop_nested_p (target_loop, pred->loop_father)) |
6a606e3c | 279 | { |
6e05e600 | 280 | /* If PRED is already higher in the loop hierarchy than the |
281 | TARGET_LOOP to that we moved FROM, the change of the position | |
282 | of FROM does not affect the position of PRED, so there is no | |
283 | point in processing it. */ | |
6a606e3c | 284 | continue; |
285 | } | |
286 | ||
08b7917c | 287 | if (bitmap_bit_p (in_queue, pred->index)) |
6a606e3c | 288 | continue; |
289 | ||
290 | /* Schedule the basic block. */ | |
291 | *qend = pred; | |
292 | qend++; | |
293 | if (qend == qtop) | |
294 | qend = queue; | |
08b7917c | 295 | bitmap_set_bit (in_queue, pred->index); |
6a606e3c | 296 | } |
297 | } | |
298 | free (in_queue); | |
299 | free (queue); | |
300 | } | |
301 | ||
302 | /* Removes path beginning at edge E, i.e. remove basic blocks dominated by E | |
7194de72 | 303 | and update loop structures and dominators. Return true if we were able |
304 | to remove the path, false otherwise (and nothing is affected then). */ | |
6a606e3c | 305 | bool |
7194de72 | 306 | remove_path (edge e) |
6a606e3c | 307 | { |
308 | edge ae; | |
3f9439d7 | 309 | basic_block *rem_bbs, *bord_bbs, from, bb; |
f1f41a6c | 310 | vec<basic_block> dom_bbs; |
1004aace | 311 | int i, nrem, n_bord_bbs; |
6a606e3c | 312 | sbitmap seen; |
611d2ac1 | 313 | bool irred_invalidated = false; |
4d50c498 | 314 | edge_iterator ei; |
753f2949 | 315 | struct loop *l, *f; |
6a606e3c | 316 | |
611d2ac1 | 317 | if (!can_remove_branch_p (e)) |
a5414ff5 | 318 | return false; |
319 | ||
afd8eb66 | 320 | /* Keep track of whether we need to update information about irreducible |
321 | regions. This is the case if the removed area is a part of the | |
322 | irreducible region, or if the set of basic blocks that belong to a loop | |
323 | that is inside an irreducible region is changed, or if such a loop is | |
324 | removed. */ | |
325 | if (e->flags & EDGE_IRREDUCIBLE_LOOP) | |
326 | irred_invalidated = true; | |
327 | ||
a5414ff5 | 328 | /* We need to check whether basic blocks are dominated by the edge |
329 | e, but we only have basic block dominators. This is easy to | |
330 | fix -- when e->dest has exactly one predecessor, this corresponds | |
331 | to blocks dominated by e->dest, if not, split the edge. */ | |
ea091dfd | 332 | if (!single_pred_p (e->dest)) |
88e6f696 | 333 | e = single_pred_edge (split_edge (e)); |
a5414ff5 | 334 | |
335 | /* It may happen that by removing path we remove one or more loops | |
336 | we belong to. In this case first unloop the loops, then proceed | |
337 | normally. We may assume that e->dest is not a header of any loop, | |
338 | as it now has exactly one predecessor. */ | |
753f2949 | 339 | for (l = e->src->loop_father; loop_outer (l); l = f) |
340 | { | |
341 | f = loop_outer (l); | |
342 | if (dominated_by_p (CDI_DOMINATORS, l->latch, e->dest)) | |
9f0ac045 | 343 | unloop (l, &irred_invalidated, NULL); |
753f2949 | 344 | } |
4c9e08a4 | 345 | |
a5414ff5 | 346 | /* Identify the path. */ |
0051c76a | 347 | nrem = find_path (e, &rem_bbs); |
6a606e3c | 348 | |
349 | n_bord_bbs = 0; | |
a28770e1 | 350 | bord_bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
fe672ac0 | 351 | seen = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 352 | bitmap_clear (seen); |
6a606e3c | 353 | |
354 | /* Find "border" hexes -- i.e. those with predecessor in removed path. */ | |
355 | for (i = 0; i < nrem; i++) | |
08b7917c | 356 | bitmap_set_bit (seen, rem_bbs[i]->index); |
4d50c498 | 357 | if (!irred_invalidated) |
358 | FOR_EACH_EDGE (ae, ei, e->src->succs) | |
34154e27 | 359 | if (ae != e && ae->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
360 | && !bitmap_bit_p (seen, ae->dest->index) | |
4d50c498 | 361 | && ae->flags & EDGE_IRREDUCIBLE_LOOP) |
b766ccbc | 362 | { |
363 | irred_invalidated = true; | |
364 | break; | |
365 | } | |
366 | ||
a5414ff5 | 367 | for (i = 0; i < nrem; i++) |
6a606e3c | 368 | { |
a5414ff5 | 369 | bb = rem_bbs[i]; |
cd665a06 | 370 | FOR_EACH_EDGE (ae, ei, rem_bbs[i]->succs) |
34154e27 | 371 | if (ae->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) |
372 | && !bitmap_bit_p (seen, ae->dest->index)) | |
a5414ff5 | 373 | { |
08b7917c | 374 | bitmap_set_bit (seen, ae->dest->index); |
a5414ff5 | 375 | bord_bbs[n_bord_bbs++] = ae->dest; |
48e1416a | 376 | |
afd8eb66 | 377 | if (ae->flags & EDGE_IRREDUCIBLE_LOOP) |
378 | irred_invalidated = true; | |
a5414ff5 | 379 | } |
6a606e3c | 380 | } |
6a606e3c | 381 | |
382 | /* Remove the path. */ | |
383 | from = e->src; | |
611d2ac1 | 384 | remove_branch (e); |
f1f41a6c | 385 | dom_bbs.create (0); |
6a606e3c | 386 | |
387 | /* Cancel loops contained in the path. */ | |
388 | for (i = 0; i < nrem; i++) | |
389 | if (rem_bbs[i]->loop_father->header == rem_bbs[i]) | |
1004aace | 390 | cancel_loop_tree (rem_bbs[i]->loop_father); |
88e6f696 | 391 | |
16ccc50c | 392 | remove_bbs (rem_bbs, nrem); |
393 | free (rem_bbs); | |
394 | ||
a5414ff5 | 395 | /* Find blocks whose dominators may be affected. */ |
53c5d9d4 | 396 | bitmap_clear (seen); |
6a606e3c | 397 | for (i = 0; i < n_bord_bbs; i++) |
398 | { | |
0051c76a | 399 | basic_block ldom; |
6a606e3c | 400 | |
0051c76a | 401 | bb = get_immediate_dominator (CDI_DOMINATORS, bord_bbs[i]); |
08b7917c | 402 | if (bitmap_bit_p (seen, bb->index)) |
6a606e3c | 403 | continue; |
08b7917c | 404 | bitmap_set_bit (seen, bb->index); |
6a606e3c | 405 | |
0051c76a | 406 | for (ldom = first_dom_son (CDI_DOMINATORS, bb); |
407 | ldom; | |
408 | ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
409 | if (!dominated_by_p (CDI_DOMINATORS, from, ldom)) | |
f1f41a6c | 410 | dom_bbs.safe_push (ldom); |
6a606e3c | 411 | } |
412 | ||
6a606e3c | 413 | free (seen); |
414 | ||
415 | /* Recount dominators. */ | |
3f9439d7 | 416 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, true); |
f1f41a6c | 417 | dom_bbs.release (); |
a5414ff5 | 418 | free (bord_bbs); |
419 | ||
6a606e3c | 420 | /* Fix placements of basic blocks inside loops and the placement of |
421 | loops in the loop tree. */ | |
9f0ac045 | 422 | fix_bb_placements (from, &irred_invalidated, NULL); |
7194de72 | 423 | fix_loop_placements (from->loop_father, &irred_invalidated); |
afd8eb66 | 424 | |
425 | if (irred_invalidated | |
f24ec26f | 426 | && loops_state_satisfies_p (LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS)) |
7194de72 | 427 | mark_irreducible_loops (); |
6a606e3c | 428 | |
429 | return true; | |
430 | } | |
431 | ||
41f75a99 | 432 | /* Creates place for a new LOOP in loops structure of FN. */ |
4a6f9e19 | 433 | |
f6568ea4 | 434 | void |
41f75a99 | 435 | place_new_loop (struct function *fn, struct loop *loop) |
6a606e3c | 436 | { |
41f75a99 | 437 | loop->num = number_of_loops (fn); |
438 | vec_safe_push (loops_for_fn (fn)->larray, loop); | |
6a606e3c | 439 | } |
440 | ||
441 | /* Given LOOP structure with filled header and latch, find the body of the | |
7194de72 | 442 | corresponding loop and add it to loops tree. Insert the LOOP as a son of |
88e6f696 | 443 | outer. */ |
444 | ||
4a6f9e19 | 445 | void |
7194de72 | 446 | add_loop (struct loop *loop, struct loop *outer) |
6a606e3c | 447 | { |
448 | basic_block *bbs; | |
449 | int i, n; | |
4a6f9e19 | 450 | struct loop *subloop; |
e88bb328 | 451 | edge e; |
452 | edge_iterator ei; | |
4c9e08a4 | 453 | |
6a606e3c | 454 | /* Add it to loop structure. */ |
41f75a99 | 455 | place_new_loop (cfun, loop); |
88e6f696 | 456 | flow_loop_tree_node_add (outer, loop); |
6a606e3c | 457 | |
458 | /* Find its nodes. */ | |
a28770e1 | 459 | bbs = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
460 | n = get_loop_body_with_size (loop, bbs, n_basic_blocks_for_fn (cfun)); | |
6a606e3c | 461 | |
462 | for (i = 0; i < n; i++) | |
88e6f696 | 463 | { |
4a6f9e19 | 464 | if (bbs[i]->loop_father == outer) |
465 | { | |
466 | remove_bb_from_loops (bbs[i]); | |
467 | add_bb_to_loop (bbs[i], loop); | |
468 | continue; | |
469 | } | |
470 | ||
471 | loop->num_nodes++; | |
472 | ||
473 | /* If we find a direct subloop of OUTER, move it to LOOP. */ | |
474 | subloop = bbs[i]->loop_father; | |
9e3536f4 | 475 | if (loop_outer (subloop) == outer |
4a6f9e19 | 476 | && subloop->header == bbs[i]) |
477 | { | |
478 | flow_loop_tree_node_remove (subloop); | |
479 | flow_loop_tree_node_add (loop, subloop); | |
480 | } | |
88e6f696 | 481 | } |
6a606e3c | 482 | |
e88bb328 | 483 | /* Update the information about loop exit edges. */ |
484 | for (i = 0; i < n; i++) | |
485 | { | |
486 | FOR_EACH_EDGE (e, ei, bbs[i]->succs) | |
487 | { | |
488 | rescan_loop_exit (e, false, false); | |
489 | } | |
490 | } | |
491 | ||
6a606e3c | 492 | free (bbs); |
493 | } | |
494 | ||
6a606e3c | 495 | /* Multiply all frequencies in LOOP by NUM/DEN. */ |
dbaa22a9 | 496 | |
7cef6c97 | 497 | void |
4c9e08a4 | 498 | scale_loop_frequencies (struct loop *loop, int num, int den) |
6a606e3c | 499 | { |
500 | basic_block *bbs; | |
501 | ||
502 | bbs = get_loop_body (loop); | |
4d6b11ab | 503 | scale_bbs_frequencies_int (bbs, loop->num_nodes, num, den); |
6a606e3c | 504 | free (bbs); |
505 | } | |
506 | ||
dbaa22a9 | 507 | /* Multiply all frequencies in LOOP by SCALE/REG_BR_PROB_BASE. |
508 | If ITERATION_BOUND is non-zero, scale even further if loop is predicted | |
509 | to iterate too many times. */ | |
510 | ||
511 | void | |
dde4834c | 512 | scale_loop_profile (struct loop *loop, int scale, gcov_type iteration_bound) |
dbaa22a9 | 513 | { |
514 | gcov_type iterations = expected_loop_iterations_unbounded (loop); | |
515 | edge e; | |
516 | edge_iterator ei; | |
517 | ||
518 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
519 | fprintf (dump_file, ";; Scaling loop %i with scale %f, " | |
520 | "bounding iterations to %i from guessed %i\n", | |
521 | loop->num, (double)scale / REG_BR_PROB_BASE, | |
dde4834c | 522 | (int)iteration_bound, (int)iterations); |
dbaa22a9 | 523 | |
524 | /* See if loop is predicted to iterate too many times. */ | |
525 | if (iteration_bound && iterations > 0 | |
f9d4b7f4 | 526 | && apply_probability (iterations, scale) > iteration_bound) |
dbaa22a9 | 527 | { |
528 | /* Fixing loop profile for different trip count is not trivial; the exit | |
529 | probabilities has to be updated to match and frequencies propagated down | |
530 | to the loop body. | |
531 | ||
532 | We fully update only the simple case of loop with single exit that is | |
533 | either from the latch or BB just before latch and leads from BB with | |
534 | simple conditional jump. This is OK for use in vectorizer. */ | |
535 | e = single_exit (loop); | |
536 | if (e) | |
537 | { | |
538 | edge other_e; | |
539 | int freq_delta; | |
540 | gcov_type count_delta; | |
541 | ||
542 | FOR_EACH_EDGE (other_e, ei, e->src->succs) | |
543 | if (!(other_e->flags & (EDGE_ABNORMAL | EDGE_FAKE)) | |
544 | && e != other_e) | |
545 | break; | |
546 | ||
547 | /* Probability of exit must be 1/iterations. */ | |
548 | freq_delta = EDGE_FREQUENCY (e); | |
549 | e->probability = REG_BR_PROB_BASE / iteration_bound; | |
550 | other_e->probability = inverse_probability (e->probability); | |
551 | freq_delta -= EDGE_FREQUENCY (e); | |
552 | ||
553 | /* Adjust counts accordingly. */ | |
554 | count_delta = e->count; | |
555 | e->count = apply_probability (e->src->count, e->probability); | |
556 | other_e->count = apply_probability (e->src->count, other_e->probability); | |
557 | count_delta -= e->count; | |
558 | ||
559 | /* If latch exists, change its frequency and count, since we changed | |
560 | probability of exit. Theoretically we should update everything from | |
561 | source of exit edge to latch, but for vectorizer this is enough. */ | |
562 | if (loop->latch | |
563 | && loop->latch != e->src) | |
564 | { | |
565 | loop->latch->frequency += freq_delta; | |
566 | if (loop->latch->frequency < 0) | |
567 | loop->latch->frequency = 0; | |
568 | loop->latch->count += count_delta; | |
569 | if (loop->latch->count < 0) | |
570 | loop->latch->count = 0; | |
571 | } | |
572 | } | |
573 | ||
574 | /* Roughly speaking we want to reduce the loop body profile by the | |
575 | the difference of loop iterations. We however can do better if | |
576 | we look at the actual profile, if it is available. */ | |
577 | scale = RDIV (iteration_bound * scale, iterations); | |
578 | if (loop->header->count) | |
579 | { | |
580 | gcov_type count_in = 0; | |
581 | ||
582 | FOR_EACH_EDGE (e, ei, loop->header->preds) | |
583 | if (e->src != loop->latch) | |
584 | count_in += e->count; | |
585 | ||
586 | if (count_in != 0) | |
f9d4b7f4 | 587 | scale = GCOV_COMPUTE_SCALE (count_in * iteration_bound, |
588 | loop->header->count); | |
dbaa22a9 | 589 | } |
590 | else if (loop->header->frequency) | |
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 | sbitmap seen; |
623 | basic_block *body; | |
624 | unsigned i; | |
625 | ||
fe672ac0 | 626 | seen = sbitmap_alloc (last_basic_block_for_fn (cfun)); |
53c5d9d4 | 627 | bitmap_clear (seen); |
255b6be7 | 628 | body = get_loop_body (loop); |
629 | ||
630 | for (i = 0; i < loop->num_nodes; i++) | |
08b7917c | 631 | bitmap_set_bit (seen, body[i]->index); |
255b6be7 | 632 | |
633 | for (i = 0; i < loop->num_nodes; i++) | |
634 | { | |
635 | basic_block ldom; | |
636 | ||
637 | for (ldom = first_dom_son (CDI_DOMINATORS, body[i]); | |
638 | ldom; | |
639 | ldom = next_dom_son (CDI_DOMINATORS, ldom)) | |
08b7917c | 640 | if (!bitmap_bit_p (seen, ldom->index)) |
255b6be7 | 641 | { |
08b7917c | 642 | bitmap_set_bit (seen, ldom->index); |
f1f41a6c | 643 | dom_bbs.safe_push (ldom); |
255b6be7 | 644 | } |
645 | } | |
646 | ||
647 | iterate_fix_dominators (CDI_DOMINATORS, dom_bbs, false); | |
648 | free (body); | |
649 | free (seen); | |
f1f41a6c | 650 | dom_bbs.release (); |
255b6be7 | 651 | } |
652 | ||
653 | /* Creates an if region as shown above. CONDITION is used to create | |
48e1416a | 654 | the test for the if. |
255b6be7 | 655 | |
656 | | | |
657 | | ------------- ------------- | |
658 | | | pred_bb | | pred_bb | | |
659 | | ------------- ------------- | |
660 | | | | | |
661 | | | | ENTRY_EDGE | |
662 | | | ENTRY_EDGE V | |
663 | | | ====> ------------- | |
664 | | | | cond_bb | | |
665 | | | | CONDITION | | |
666 | | | ------------- | |
667 | | V / \ | |
668 | | ------------- e_false / \ e_true | |
669 | | | succ_bb | V V | |
670 | | ------------- ----------- ----------- | |
671 | | | false_bb | | true_bb | | |
672 | | ----------- ----------- | |
673 | | \ / | |
674 | | \ / | |
675 | | V V | |
676 | | ------------- | |
677 | | | join_bb | | |
678 | | ------------- | |
679 | | | exit_edge (result) | |
680 | | V | |
681 | | ----------- | |
682 | | | succ_bb | | |
683 | | ----------- | |
684 | | | |
685 | */ | |
686 | ||
687 | edge | |
688 | create_empty_if_region_on_edge (edge entry_edge, tree condition) | |
689 | { | |
690 | ||
6d86fc31 | 691 | basic_block cond_bb, true_bb, false_bb, join_bb; |
255b6be7 | 692 | edge e_true, e_false, exit_edge; |
693 | gimple cond_stmt; | |
694 | tree simple_cond; | |
695 | gimple_stmt_iterator gsi; | |
696 | ||
255b6be7 | 697 | cond_bb = split_edge (entry_edge); |
48e1416a | 698 | |
255b6be7 | 699 | /* Insert condition in cond_bb. */ |
700 | gsi = gsi_last_bb (cond_bb); | |
701 | simple_cond = | |
702 | force_gimple_operand_gsi (&gsi, condition, true, NULL, | |
703 | false, GSI_NEW_STMT); | |
704 | cond_stmt = gimple_build_cond_from_tree (simple_cond, NULL_TREE, NULL_TREE); | |
705 | gsi = gsi_last_bb (cond_bb); | |
706 | gsi_insert_after (&gsi, cond_stmt, GSI_NEW_STMT); | |
48e1416a | 707 | |
255b6be7 | 708 | join_bb = split_edge (single_succ_edge (cond_bb)); |
709 | ||
710 | e_true = single_succ_edge (cond_bb); | |
711 | true_bb = split_edge (e_true); | |
712 | ||
713 | e_false = make_edge (cond_bb, join_bb, 0); | |
714 | false_bb = split_edge (e_false); | |
715 | ||
716 | e_true->flags &= ~EDGE_FALLTHRU; | |
717 | e_true->flags |= EDGE_TRUE_VALUE; | |
718 | e_false->flags &= ~EDGE_FALLTHRU; | |
719 | e_false->flags |= EDGE_FALSE_VALUE; | |
720 | ||
721 | set_immediate_dominator (CDI_DOMINATORS, cond_bb, entry_edge->src); | |
722 | set_immediate_dominator (CDI_DOMINATORS, true_bb, cond_bb); | |
723 | set_immediate_dominator (CDI_DOMINATORS, false_bb, cond_bb); | |
724 | set_immediate_dominator (CDI_DOMINATORS, join_bb, cond_bb); | |
725 | ||
726 | exit_edge = single_succ_edge (join_bb); | |
727 | ||
728 | if (single_pred_p (exit_edge->dest)) | |
729 | set_immediate_dominator (CDI_DOMINATORS, exit_edge->dest, join_bb); | |
730 | ||
731 | return exit_edge; | |
732 | } | |
733 | ||
734 | /* create_empty_loop_on_edge | |
735 | | | |
b65ec27f | 736 | | - pred_bb - ------ pred_bb ------ |
737 | | | | | iv0 = initial_value | | |
738 | | -----|----- ---------|----------- | |
739 | | | ______ | entry_edge | |
740 | | | entry_edge / | | | |
741 | | | ====> | -V---V- loop_header ------------- | |
742 | | V | | iv_before = phi (iv0, iv_after) | | |
743 | | - succ_bb - | ---|----------------------------- | |
744 | | | | | | | |
745 | | ----------- | ---V--- loop_body --------------- | |
746 | | | | iv_after = iv_before + stride | | |
02df46c6 | 747 | | | | if (iv_before < upper_bound) | |
b65ec27f | 748 | | | ---|--------------\-------------- |
749 | | | | \ exit_e | |
750 | | | V \ | |
751 | | | - loop_latch - V- succ_bb - | |
752 | | | | | | | | |
753 | | | /------------- ----------- | |
754 | | \ ___ / | |
255b6be7 | 755 | |
756 | Creates an empty loop as shown above, the IV_BEFORE is the SSA_NAME | |
02df46c6 | 757 | that is used before the increment of IV. IV_BEFORE should be used for |
255b6be7 | 758 | adding code to the body that uses the IV. OUTER is the outer loop in |
02df46c6 | 759 | which the new loop should be inserted. |
b65ec27f | 760 | |
761 | Both INITIAL_VALUE and UPPER_BOUND expressions are gimplified and | |
762 | inserted on the loop entry edge. This implies that this function | |
763 | should be used only when the UPPER_BOUND expression is a loop | |
764 | invariant. */ | |
255b6be7 | 765 | |
766 | struct loop * | |
02df46c6 | 767 | create_empty_loop_on_edge (edge entry_edge, |
255b6be7 | 768 | tree initial_value, |
769 | tree stride, tree upper_bound, | |
770 | tree iv, | |
771 | tree *iv_before, | |
b65ec27f | 772 | tree *iv_after, |
255b6be7 | 773 | struct loop *outer) |
774 | { | |
775 | basic_block loop_header, loop_latch, succ_bb, pred_bb; | |
776 | struct loop *loop; | |
255b6be7 | 777 | gimple_stmt_iterator gsi; |
255b6be7 | 778 | gimple_seq stmts; |
779 | gimple cond_expr; | |
780 | tree exit_test; | |
781 | edge exit_e; | |
782 | int prob; | |
02df46c6 | 783 | |
255b6be7 | 784 | gcc_assert (entry_edge && initial_value && stride && upper_bound && iv); |
785 | ||
786 | /* Create header, latch and wire up the loop. */ | |
787 | pred_bb = entry_edge->src; | |
788 | loop_header = split_edge (entry_edge); | |
789 | loop_latch = split_edge (single_succ_edge (loop_header)); | |
790 | succ_bb = single_succ (loop_latch); | |
791 | make_edge (loop_header, succ_bb, 0); | |
792 | redirect_edge_succ_nodup (single_succ_edge (loop_latch), loop_header); | |
793 | ||
794 | /* Set immediate dominator information. */ | |
795 | set_immediate_dominator (CDI_DOMINATORS, loop_header, pred_bb); | |
796 | set_immediate_dominator (CDI_DOMINATORS, loop_latch, loop_header); | |
797 | set_immediate_dominator (CDI_DOMINATORS, succ_bb, loop_header); | |
798 | ||
799 | /* Initialize a loop structure and put it in a loop hierarchy. */ | |
800 | loop = alloc_loop (); | |
801 | loop->header = loop_header; | |
802 | loop->latch = loop_latch; | |
803 | add_loop (loop, outer); | |
804 | ||
805 | /* TODO: Fix frequencies and counts. */ | |
255b6be7 | 806 | prob = REG_BR_PROB_BASE / 2; |
807 | ||
808 | scale_loop_frequencies (loop, REG_BR_PROB_BASE - prob, REG_BR_PROB_BASE); | |
809 | ||
810 | /* Update dominators. */ | |
811 | update_dominators_in_loop (loop); | |
812 | ||
b65ec27f | 813 | /* Modify edge flags. */ |
814 | exit_e = single_exit (loop); | |
815 | exit_e->flags = EDGE_LOOP_EXIT | EDGE_FALSE_VALUE; | |
816 | single_pred_edge (loop_latch)->flags = EDGE_TRUE_VALUE; | |
817 | ||
255b6be7 | 818 | /* Construct IV code in loop. */ |
819 | initial_value = force_gimple_operand (initial_value, &stmts, true, iv); | |
820 | if (stmts) | |
821 | { | |
822 | gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts); | |
823 | gsi_commit_edge_inserts (); | |
824 | } | |
825 | ||
b65ec27f | 826 | upper_bound = force_gimple_operand (upper_bound, &stmts, true, NULL); |
827 | if (stmts) | |
828 | { | |
829 | gsi_insert_seq_on_edge (loop_preheader_edge (loop), stmts); | |
830 | gsi_commit_edge_inserts (); | |
831 | } | |
255b6be7 | 832 | |
b65ec27f | 833 | gsi = gsi_last_bb (loop_header); |
834 | create_iv (initial_value, stride, iv, loop, &gsi, false, | |
835 | iv_before, iv_after); | |
255b6be7 | 836 | |
b65ec27f | 837 | /* Insert loop exit condition. */ |
838 | cond_expr = gimple_build_cond | |
02df46c6 | 839 | (LT_EXPR, *iv_before, upper_bound, NULL_TREE, NULL_TREE); |
255b6be7 | 840 | |
841 | exit_test = gimple_cond_lhs (cond_expr); | |
842 | exit_test = force_gimple_operand_gsi (&gsi, exit_test, true, NULL, | |
843 | false, GSI_NEW_STMT); | |
844 | gimple_cond_set_lhs (cond_expr, exit_test); | |
845 | gsi = gsi_last_bb (exit_e->src); | |
846 | gsi_insert_after (&gsi, cond_expr, GSI_NEW_STMT); | |
847 | ||
b65ec27f | 848 | split_block_after_labels (loop_header); |
849 | ||
255b6be7 | 850 | return loop; |
851 | } | |
852 | ||
6a606e3c | 853 | /* Make area between HEADER_EDGE and LATCH_EDGE a loop by connecting |
7194de72 | 854 | latch to header and update loop tree and dominators |
6a606e3c | 855 | accordingly. Everything between them plus LATCH_EDGE destination must |
856 | be dominated by HEADER_EDGE destination, and back-reachable from | |
857 | LATCH_EDGE source. HEADER_EDGE is redirected to basic block SWITCH_BB, | |
0dc32828 | 858 | FALSE_EDGE of SWITCH_BB to original destination of HEADER_EDGE and |
859 | TRUE_EDGE of SWITCH_BB to original destination of LATCH_EDGE. | |
7cef6c97 | 860 | Returns the newly created loop. Frequencies and counts in the new loop |
861 | are scaled by FALSE_SCALE and in the old one by TRUE_SCALE. */ | |
f9cce2dc | 862 | |
6a606e3c | 863 | struct loop * |
7194de72 | 864 | loopify (edge latch_edge, edge header_edge, |
0dc32828 | 865 | basic_block switch_bb, edge true_edge, edge false_edge, |
7cef6c97 | 866 | bool redirect_all_edges, unsigned true_scale, unsigned false_scale) |
6a606e3c | 867 | { |
868 | basic_block succ_bb = latch_edge->dest; | |
869 | basic_block pred_bb = header_edge->src; | |
dce58e66 | 870 | struct loop *loop = alloc_loop (); |
9e3536f4 | 871 | struct loop *outer = loop_outer (succ_bb->loop_father); |
7cef6c97 | 872 | int freq; |
6a606e3c | 873 | gcov_type cnt; |
874 | edge e; | |
cd665a06 | 875 | edge_iterator ei; |
6a606e3c | 876 | |
877 | loop->header = header_edge->dest; | |
878 | loop->latch = latch_edge->src; | |
879 | ||
880 | freq = EDGE_FREQUENCY (header_edge); | |
881 | cnt = header_edge->count; | |
6a606e3c | 882 | |
883 | /* Redirect edges. */ | |
884 | loop_redirect_edge (latch_edge, loop->header); | |
0dc32828 | 885 | loop_redirect_edge (true_edge, succ_bb); |
f9cce2dc | 886 | |
e12d0591 | 887 | /* During loop versioning, one of the switch_bb edge is already properly |
888 | set. Do not redirect it again unless redirect_all_edges is true. */ | |
889 | if (redirect_all_edges) | |
890 | { | |
891 | loop_redirect_edge (header_edge, switch_bb); | |
a0c938f0 | 892 | loop_redirect_edge (false_edge, loop->header); |
893 | ||
e12d0591 | 894 | /* Update dominators. */ |
895 | set_immediate_dominator (CDI_DOMINATORS, switch_bb, pred_bb); | |
896 | set_immediate_dominator (CDI_DOMINATORS, loop->header, switch_bb); | |
897 | } | |
f9cce2dc | 898 | |
0051c76a | 899 | set_immediate_dominator (CDI_DOMINATORS, succ_bb, switch_bb); |
6a606e3c | 900 | |
901 | /* Compute new loop. */ | |
7194de72 | 902 | add_loop (loop, outer); |
6a606e3c | 903 | |
904 | /* Add switch_bb to appropriate loop. */ | |
88e6f696 | 905 | if (switch_bb->loop_father) |
906 | remove_bb_from_loops (switch_bb); | |
6a606e3c | 907 | add_bb_to_loop (switch_bb, outer); |
908 | ||
909 | /* Fix frequencies. */ | |
7cef6c97 | 910 | if (redirect_all_edges) |
911 | { | |
912 | switch_bb->frequency = freq; | |
913 | switch_bb->count = cnt; | |
914 | FOR_EACH_EDGE (e, ei, switch_bb->succs) | |
915 | { | |
f9d4b7f4 | 916 | e->count = apply_probability (switch_bb->count, e->probability); |
7cef6c97 | 917 | } |
918 | } | |
919 | scale_loop_frequencies (loop, false_scale, REG_BR_PROB_BASE); | |
920 | scale_loop_frequencies (succ_bb->loop_father, true_scale, REG_BR_PROB_BASE); | |
255b6be7 | 921 | update_dominators_in_loop (loop); |
6a606e3c | 922 | |
923 | return loop; | |
924 | } | |
925 | ||
7194de72 | 926 | /* Remove the latch edge of a LOOP and update loops to indicate that |
a5414ff5 | 927 | the LOOP was removed. After this function, original loop latch will |
afd8eb66 | 928 | have no successor, which caller is expected to fix somehow. |
929 | ||
930 | If this may cause the information about irreducible regions to become | |
9f0ac045 | 931 | invalid, IRRED_INVALIDATED is set to true. |
932 | ||
933 | LOOP_CLOSED_SSA_INVALIDATED, if non-NULL, is a bitmap where we store | |
934 | basic blocks that had non-trivial update on their loop_father.*/ | |
afd8eb66 | 935 | |
c790d986 | 936 | void |
9f0ac045 | 937 | unloop (struct loop *loop, bool *irred_invalidated, |
938 | bitmap loop_closed_ssa_invalidated) | |
a5414ff5 | 939 | { |
940 | basic_block *body; | |
941 | struct loop *ploop; | |
942 | unsigned i, n; | |
943 | basic_block latch = loop->latch; | |
afd8eb66 | 944 | bool dummy = false; |
945 | ||
946 | if (loop_preheader_edge (loop)->flags & EDGE_IRREDUCIBLE_LOOP) | |
947 | *irred_invalidated = true; | |
a5414ff5 | 948 | |
d01481af | 949 | /* This is relatively straightforward. The dominators are unchanged, as |
a5414ff5 | 950 | loop header dominates loop latch, so the only thing we have to care of |
951 | is the placement of loops and basic blocks inside the loop tree. We | |
952 | move them all to the loop->outer, and then let fix_bb_placements do | |
953 | its work. */ | |
954 | ||
955 | body = get_loop_body (loop); | |
a5414ff5 | 956 | n = loop->num_nodes; |
957 | for (i = 0; i < n; i++) | |
958 | if (body[i]->loop_father == loop) | |
959 | { | |
960 | remove_bb_from_loops (body[i]); | |
9e3536f4 | 961 | add_bb_to_loop (body[i], loop_outer (loop)); |
a5414ff5 | 962 | } |
9af5ce0c | 963 | free (body); |
a5414ff5 | 964 | |
965 | while (loop->inner) | |
966 | { | |
967 | ploop = loop->inner; | |
968 | flow_loop_tree_node_remove (ploop); | |
9e3536f4 | 969 | flow_loop_tree_node_add (loop_outer (loop), ploop); |
a5414ff5 | 970 | } |
971 | ||
972 | /* Remove the loop and free its data. */ | |
17519ba0 | 973 | delete_loop (loop); |
a5414ff5 | 974 | |
ea091dfd | 975 | remove_edge (single_succ_edge (latch)); |
afd8eb66 | 976 | |
977 | /* We do not pass IRRED_INVALIDATED to fix_bb_placements here, as even if | |
978 | there is an irreducible region inside the cancelled loop, the flags will | |
979 | be still correct. */ | |
9f0ac045 | 980 | fix_bb_placements (latch, &dummy, loop_closed_ssa_invalidated); |
a5414ff5 | 981 | } |
982 | ||
6a606e3c | 983 | /* Fix placement of superloops of LOOP inside loop tree, i.e. ensure that |
984 | condition stated in description of fix_loop_placement holds for them. | |
985 | It is used in case when we removed some edges coming out of LOOP, which | |
afd8eb66 | 986 | may cause the right placement of LOOP inside loop tree to change. |
48e1416a | 987 | |
afd8eb66 | 988 | IRRED_INVALIDATED is set to true if a change in the loop structures might |
989 | invalidate the information about irreducible regions. */ | |
990 | ||
6a606e3c | 991 | static void |
7194de72 | 992 | fix_loop_placements (struct loop *loop, bool *irred_invalidated) |
6a606e3c | 993 | { |
994 | struct loop *outer; | |
995 | ||
9e3536f4 | 996 | while (loop_outer (loop)) |
6a606e3c | 997 | { |
9e3536f4 | 998 | outer = loop_outer (loop); |
c1f96968 | 999 | if (!fix_loop_placement (loop, irred_invalidated)) |
a0c938f0 | 1000 | break; |
82233aad | 1001 | |
1002 | /* Changing the placement of a loop in the loop tree may alter the | |
1003 | validity of condition 2) of the description of fix_bb_placement | |
1004 | for its preheader, because the successor is the header and belongs | |
1005 | to the loop. So call fix_bb_placements to fix up the placement | |
1006 | of the preheader and (possibly) of its predecessors. */ | |
7194de72 | 1007 | fix_bb_placements (loop_preheader_edge (loop)->src, |
9f0ac045 | 1008 | irred_invalidated, NULL); |
6a606e3c | 1009 | loop = outer; |
1010 | } | |
1011 | } | |
1012 | ||
efa7c5bd | 1013 | /* Duplicate loop bounds and other information we store about |
1014 | the loop into its duplicate. */ | |
1015 | ||
1016 | void | |
1017 | copy_loop_info (struct loop *loop, struct loop *target) | |
1018 | { | |
1019 | gcc_checking_assert (!target->any_upper_bound && !target->any_estimate); | |
1020 | target->any_upper_bound = loop->any_upper_bound; | |
1021 | target->nb_iterations_upper_bound = loop->nb_iterations_upper_bound; | |
1022 | target->any_estimate = loop->any_estimate; | |
1023 | target->nb_iterations_estimate = loop->nb_iterations_estimate; | |
1024 | target->estimate_state = loop->estimate_state; | |
1025 | } | |
1026 | ||
6a606e3c | 1027 | /* Copies copy of LOOP as subloop of TARGET loop, placing newly |
7194de72 | 1028 | created loop into loops structure. */ |
50caf588 | 1029 | struct loop * |
7194de72 | 1030 | duplicate_loop (struct loop *loop, struct loop *target) |
6a606e3c | 1031 | { |
1032 | struct loop *cloop; | |
dce58e66 | 1033 | cloop = alloc_loop (); |
41f75a99 | 1034 | place_new_loop (cfun, cloop); |
efa7c5bd | 1035 | |
1036 | copy_loop_info (loop, cloop); | |
6a606e3c | 1037 | |
8543a448 | 1038 | /* Mark the new loop as copy of LOOP. */ |
96c90e5e | 1039 | set_loop_copy (loop, cloop); |
6a606e3c | 1040 | |
1041 | /* Add it to target. */ | |
1042 | flow_loop_tree_node_add (target, cloop); | |
1043 | ||
1044 | return cloop; | |
1045 | } | |
1046 | ||
1047 | /* Copies structure of subloops of LOOP into TARGET loop, placing | |
7194de72 | 1048 | newly created loops into loop tree. */ |
b0fb253a | 1049 | void |
7194de72 | 1050 | duplicate_subloops (struct loop *loop, struct loop *target) |
6a606e3c | 1051 | { |
1052 | struct loop *aloop, *cloop; | |
1053 | ||
1054 | for (aloop = loop->inner; aloop; aloop = aloop->next) | |
1055 | { | |
7194de72 | 1056 | cloop = duplicate_loop (aloop, target); |
1057 | duplicate_subloops (aloop, cloop); | |
6a606e3c | 1058 | } |
1059 | } | |
1060 | ||
1061 | /* Copies structure of subloops of N loops, stored in array COPIED_LOOPS, | |
7194de72 | 1062 | into TARGET loop, placing newly created loops into loop tree. */ |
4c9e08a4 | 1063 | static void |
7194de72 | 1064 | copy_loops_to (struct loop **copied_loops, int n, struct loop *target) |
6a606e3c | 1065 | { |
1066 | struct loop *aloop; | |
1067 | int i; | |
1068 | ||
1069 | for (i = 0; i < n; i++) | |
1070 | { | |
7194de72 | 1071 | aloop = duplicate_loop (copied_loops[i], target); |
1072 | duplicate_subloops (copied_loops[i], aloop); | |
6a606e3c | 1073 | } |
1074 | } | |
1075 | ||
1076 | /* Redirects edge E to basic block DEST. */ | |
1077 | static void | |
4c9e08a4 | 1078 | loop_redirect_edge (edge e, basic_block dest) |
6a606e3c | 1079 | { |
1080 | if (e->dest == dest) | |
1081 | return; | |
1082 | ||
1026363d | 1083 | redirect_edge_and_branch_force (e, dest); |
6a606e3c | 1084 | } |
1085 | ||
6a606e3c | 1086 | /* Check whether LOOP's body can be duplicated. */ |
1087 | bool | |
7ecb5bb2 | 1088 | can_duplicate_loop_p (const struct loop *loop) |
6a606e3c | 1089 | { |
dbfc1664 | 1090 | int ret; |
1091 | basic_block *bbs = get_loop_body (loop); | |
6a606e3c | 1092 | |
dbfc1664 | 1093 | ret = can_copy_bbs_p (bbs, loop->num_nodes); |
6a606e3c | 1094 | free (bbs); |
a0c938f0 | 1095 | |
dbfc1664 | 1096 | return ret; |
6a606e3c | 1097 | } |
1098 | ||
7cef6c97 | 1099 | /* Sets probability and count of edge E to zero. The probability and count |
1100 | is redistributed evenly to the remaining edges coming from E->src. */ | |
1101 | ||
1102 | static void | |
1103 | set_zero_probability (edge e) | |
1104 | { | |
1105 | basic_block bb = e->src; | |
1106 | edge_iterator ei; | |
1107 | edge ae, last = NULL; | |
1108 | unsigned n = EDGE_COUNT (bb->succs); | |
1109 | gcov_type cnt = e->count, cnt1; | |
1110 | unsigned prob = e->probability, prob1; | |
1111 | ||
1112 | gcc_assert (n > 1); | |
1113 | cnt1 = cnt / (n - 1); | |
1114 | prob1 = prob / (n - 1); | |
1115 | ||
1116 | FOR_EACH_EDGE (ae, ei, bb->succs) | |
1117 | { | |
1118 | if (ae == e) | |
1119 | continue; | |
1120 | ||
1121 | ae->probability += prob1; | |
1122 | ae->count += cnt1; | |
1123 | last = ae; | |
1124 | } | |
1125 | ||
1126 | /* Move the rest to one of the edges. */ | |
1127 | last->probability += prob % (n - 1); | |
1128 | last->count += cnt % (n - 1); | |
1129 | ||
1130 | e->probability = 0; | |
1131 | e->count = 0; | |
1132 | } | |
1133 | ||
dbfc1664 | 1134 | /* Duplicates body of LOOP to given edge E NDUPL times. Takes care of updating |
7194de72 | 1135 | loop structure and dominators. E's destination must be LOOP header for |
dbfc1664 | 1136 | this to work, i.e. it must be entry or latch edge of this loop; these are |
1137 | unique, as the loops must have preheaders for this function to work | |
1138 | correctly (in case E is latch, the function unrolls the loop, if E is entry | |
1139 | edge, it peels the loop). Store edges created by copying ORIG edge from | |
1140 | copies corresponding to set bits in WONT_EXIT bitmap (bit 0 corresponds to | |
1141 | original LOOP body, the other copies are numbered in order given by control | |
1142 | flow through them) into TO_REMOVE array. Returns false if duplication is | |
1143 | impossible. */ | |
f3c40e6d | 1144 | |
c50ae675 | 1145 | bool |
7194de72 | 1146 | duplicate_loop_to_header_edge (struct loop *loop, edge e, |
4c9e08a4 | 1147 | unsigned int ndupl, sbitmap wont_exit, |
f1f41a6c | 1148 | edge orig, vec<edge> *to_remove, |
f3c40e6d | 1149 | int flags) |
6a606e3c | 1150 | { |
1151 | struct loop *target, *aloop; | |
1152 | struct loop **orig_loops; | |
1153 | unsigned n_orig_loops; | |
1154 | basic_block header = loop->header, latch = loop->latch; | |
1155 | basic_block *new_bbs, *bbs, *first_active; | |
1156 | basic_block new_bb, bb, first_active_latch = NULL; | |
dbfc1664 | 1157 | edge ae, latch_edge; |
1158 | edge spec_edges[2], new_spec_edges[2]; | |
1159 | #define SE_LATCH 0 | |
1160 | #define SE_ORIG 1 | |
6a606e3c | 1161 | unsigned i, j, n; |
1162 | int is_latch = (latch == e->src); | |
1163 | int scale_act = 0, *scale_step = NULL, scale_main = 0; | |
7cef6c97 | 1164 | int scale_after_exit = 0; |
6a606e3c | 1165 | int p, freq_in, freq_le, freq_out_orig; |
1166 | int prob_pass_thru, prob_pass_wont_exit, prob_pass_main; | |
1167 | int add_irreducible_flag; | |
c4d867e0 | 1168 | basic_block place_after; |
7cef6c97 | 1169 | bitmap bbs_to_scale = NULL; |
1170 | bitmap_iterator bi; | |
6a606e3c | 1171 | |
cc636d56 | 1172 | gcc_assert (e->dest == loop->header); |
1173 | gcc_assert (ndupl > 0); | |
6a606e3c | 1174 | |
1175 | if (orig) | |
1176 | { | |
1177 | /* Orig must be edge out of the loop. */ | |
cc636d56 | 1178 | gcc_assert (flow_bb_inside_loop_p (loop, orig->src)); |
1179 | gcc_assert (!flow_bb_inside_loop_p (loop, orig->dest)); | |
6a606e3c | 1180 | } |
1181 | ||
c4d867e0 | 1182 | n = loop->num_nodes; |
1183 | bbs = get_loop_body_in_dom_order (loop); | |
1184 | gcc_assert (bbs[0] == loop->header); | |
1185 | gcc_assert (bbs[n - 1] == loop->latch); | |
6a606e3c | 1186 | |
1187 | /* Check whether duplication is possible. */ | |
dbfc1664 | 1188 | if (!can_copy_bbs_p (bbs, loop->num_nodes)) |
6a606e3c | 1189 | { |
dbfc1664 | 1190 | free (bbs); |
1191 | return false; | |
6a606e3c | 1192 | } |
4c36ffe6 | 1193 | new_bbs = XNEWVEC (basic_block, loop->num_nodes); |
6a606e3c | 1194 | |
dbfc1664 | 1195 | /* In case we are doing loop peeling and the loop is in the middle of |
1196 | irreducible region, the peeled copies will be inside it too. */ | |
1197 | add_irreducible_flag = e->flags & EDGE_IRREDUCIBLE_LOOP; | |
cc636d56 | 1198 | gcc_assert (!is_latch || !add_irreducible_flag); |
6a606e3c | 1199 | |
1200 | /* Find edge from latch. */ | |
1201 | latch_edge = loop_latch_edge (loop); | |
1202 | ||
1203 | if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
1204 | { | |
1205 | /* Calculate coefficients by that we have to scale frequencies | |
1206 | of duplicated loop bodies. */ | |
1207 | freq_in = header->frequency; | |
1208 | freq_le = EDGE_FREQUENCY (latch_edge); | |
1209 | if (freq_in == 0) | |
1210 | freq_in = 1; | |
1211 | if (freq_in < freq_le) | |
1212 | freq_in = freq_le; | |
1213 | freq_out_orig = orig ? EDGE_FREQUENCY (orig) : freq_in - freq_le; | |
1214 | if (freq_out_orig > freq_in - freq_le) | |
1215 | freq_out_orig = freq_in - freq_le; | |
1216 | prob_pass_thru = RDIV (REG_BR_PROB_BASE * freq_le, freq_in); | |
1217 | prob_pass_wont_exit = | |
1218 | RDIV (REG_BR_PROB_BASE * (freq_le + freq_out_orig), freq_in); | |
1219 | ||
7cef6c97 | 1220 | if (orig |
1221 | && REG_BR_PROB_BASE - orig->probability != 0) | |
1222 | { | |
1223 | /* The blocks that are dominated by a removed exit edge ORIG have | |
1224 | frequencies scaled by this. */ | |
f9d4b7f4 | 1225 | scale_after_exit |
1226 | = GCOV_COMPUTE_SCALE (REG_BR_PROB_BASE, | |
1227 | REG_BR_PROB_BASE - orig->probability); | |
7cef6c97 | 1228 | bbs_to_scale = BITMAP_ALLOC (NULL); |
1229 | for (i = 0; i < n; i++) | |
1230 | { | |
1231 | if (bbs[i] != orig->src | |
1232 | && dominated_by_p (CDI_DOMINATORS, bbs[i], orig->src)) | |
1233 | bitmap_set_bit (bbs_to_scale, i); | |
1234 | } | |
1235 | } | |
1236 | ||
4c36ffe6 | 1237 | scale_step = XNEWVEC (int, ndupl); |
6a606e3c | 1238 | |
7cef6c97 | 1239 | for (i = 1; i <= ndupl; i++) |
08b7917c | 1240 | scale_step[i - 1] = bitmap_bit_p (wont_exit, i) |
6a606e3c | 1241 | ? prob_pass_wont_exit |
1242 | : prob_pass_thru; | |
1243 | ||
3ce7ff97 | 1244 | /* Complete peeling is special as the probability of exit in last |
a0c938f0 | 1245 | copy becomes 1. */ |
fb54ef7c | 1246 | if (flags & DLTHE_FLAG_COMPLETTE_PEEL) |
1247 | { | |
1248 | int wanted_freq = EDGE_FREQUENCY (e); | |
1249 | ||
1250 | if (wanted_freq > freq_in) | |
1251 | wanted_freq = freq_in; | |
1252 | ||
1253 | gcc_assert (!is_latch); | |
3ce7ff97 | 1254 | /* First copy has frequency of incoming edge. Each subsequent |
fb54ef7c | 1255 | frequency should be reduced by prob_pass_wont_exit. Caller |
1256 | should've managed the flags so all except for original loop | |
1257 | has won't exist set. */ | |
f9d4b7f4 | 1258 | scale_act = GCOV_COMPUTE_SCALE (wanted_freq, freq_in); |
fb54ef7c | 1259 | /* Now simulate the duplication adjustments and compute header |
1260 | frequency of the last copy. */ | |
1261 | for (i = 0; i < ndupl; i++) | |
f9d4b7f4 | 1262 | wanted_freq = combine_probabilities (wanted_freq, scale_step[i]); |
1263 | scale_main = GCOV_COMPUTE_SCALE (wanted_freq, freq_in); | |
fb54ef7c | 1264 | } |
1265 | else if (is_latch) | |
6a606e3c | 1266 | { |
08b7917c | 1267 | prob_pass_main = bitmap_bit_p (wont_exit, 0) |
6a606e3c | 1268 | ? prob_pass_wont_exit |
1269 | : prob_pass_thru; | |
1270 | p = prob_pass_main; | |
1271 | scale_main = REG_BR_PROB_BASE; | |
1272 | for (i = 0; i < ndupl; i++) | |
1273 | { | |
1274 | scale_main += p; | |
f9d4b7f4 | 1275 | p = combine_probabilities (p, scale_step[i]); |
6a606e3c | 1276 | } |
f9d4b7f4 | 1277 | scale_main = GCOV_COMPUTE_SCALE (REG_BR_PROB_BASE, scale_main); |
1278 | scale_act = combine_probabilities (scale_main, prob_pass_main); | |
6a606e3c | 1279 | } |
1280 | else | |
1281 | { | |
1282 | scale_main = REG_BR_PROB_BASE; | |
1283 | for (i = 0; i < ndupl; i++) | |
f9d4b7f4 | 1284 | scale_main = combine_probabilities (scale_main, scale_step[i]); |
6a606e3c | 1285 | scale_act = REG_BR_PROB_BASE - prob_pass_thru; |
1286 | } | |
1287 | for (i = 0; i < ndupl; i++) | |
cc636d56 | 1288 | gcc_assert (scale_step[i] >= 0 && scale_step[i] <= REG_BR_PROB_BASE); |
1289 | gcc_assert (scale_main >= 0 && scale_main <= REG_BR_PROB_BASE | |
1290 | && scale_act >= 0 && scale_act <= REG_BR_PROB_BASE); | |
6a606e3c | 1291 | } |
1292 | ||
1293 | /* Loop the new bbs will belong to. */ | |
dbfc1664 | 1294 | target = e->src->loop_father; |
6a606e3c | 1295 | |
1296 | /* Original loops. */ | |
1297 | n_orig_loops = 0; | |
1298 | for (aloop = loop->inner; aloop; aloop = aloop->next) | |
1299 | n_orig_loops++; | |
ed7e2206 | 1300 | orig_loops = XNEWVEC (struct loop *, n_orig_loops); |
6a606e3c | 1301 | for (aloop = loop->inner, i = 0; aloop; aloop = aloop->next, i++) |
1302 | orig_loops[i] = aloop; | |
1303 | ||
96c90e5e | 1304 | set_loop_copy (loop, target); |
4c9e08a4 | 1305 | |
4c36ffe6 | 1306 | first_active = XNEWVEC (basic_block, n); |
6a606e3c | 1307 | if (is_latch) |
1308 | { | |
1309 | memcpy (first_active, bbs, n * sizeof (basic_block)); | |
1310 | first_active_latch = latch; | |
1311 | } | |
1312 | ||
dbfc1664 | 1313 | spec_edges[SE_ORIG] = orig; |
1314 | spec_edges[SE_LATCH] = latch_edge; | |
4c9e08a4 | 1315 | |
c4d867e0 | 1316 | place_after = e->src; |
6a606e3c | 1317 | for (j = 0; j < ndupl; j++) |
1318 | { | |
1319 | /* Copy loops. */ | |
7194de72 | 1320 | copy_loops_to (orig_loops, n_orig_loops, target); |
6a606e3c | 1321 | |
1322 | /* Copy bbs. */ | |
c4d867e0 | 1323 | copy_bbs (bbs, n, new_bbs, spec_edges, 2, new_spec_edges, loop, |
d99f53b2 | 1324 | place_after, true); |
c4d867e0 | 1325 | place_after = new_spec_edges[SE_LATCH]->src; |
dbfc1664 | 1326 | |
75cc36a4 | 1327 | if (flags & DLTHE_RECORD_COPY_NUMBER) |
1328 | for (i = 0; i < n; i++) | |
1329 | { | |
1330 | gcc_assert (!new_bbs[i]->aux); | |
1331 | new_bbs[i]->aux = (void *)(size_t)(j + 1); | |
1332 | } | |
a9989fb4 | 1333 | |
d493f913 | 1334 | /* Note whether the blocks and edges belong to an irreducible loop. */ |
1335 | if (add_irreducible_flag) | |
1336 | { | |
1337 | for (i = 0; i < n; i++) | |
01020a5f | 1338 | new_bbs[i]->flags |= BB_DUPLICATED; |
d493f913 | 1339 | for (i = 0; i < n; i++) |
1340 | { | |
cd665a06 | 1341 | edge_iterator ei; |
d493f913 | 1342 | new_bb = new_bbs[i]; |
1343 | if (new_bb->loop_father == target) | |
1344 | new_bb->flags |= BB_IRREDUCIBLE_LOOP; | |
1345 | ||
cd665a06 | 1346 | FOR_EACH_EDGE (ae, ei, new_bb->succs) |
01020a5f | 1347 | if ((ae->dest->flags & BB_DUPLICATED) |
d493f913 | 1348 | && (ae->src->loop_father == target |
1349 | || ae->dest->loop_father == target)) | |
1350 | ae->flags |= EDGE_IRREDUCIBLE_LOOP; | |
1351 | } | |
1352 | for (i = 0; i < n; i++) | |
01020a5f | 1353 | new_bbs[i]->flags &= ~BB_DUPLICATED; |
d493f913 | 1354 | } |
1355 | ||
dbfc1664 | 1356 | /* Redirect the special edges. */ |
6a606e3c | 1357 | if (is_latch) |
dbfc1664 | 1358 | { |
1359 | redirect_edge_and_branch_force (latch_edge, new_bbs[0]); | |
1360 | redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
1361 | loop->header); | |
0051c76a | 1362 | set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], latch); |
c4d867e0 | 1363 | latch = loop->latch = new_bbs[n - 1]; |
dbfc1664 | 1364 | e = latch_edge = new_spec_edges[SE_LATCH]; |
1365 | } | |
1366 | else | |
1367 | { | |
1368 | redirect_edge_and_branch_force (new_spec_edges[SE_LATCH], | |
1369 | loop->header); | |
1370 | redirect_edge_and_branch_force (e, new_bbs[0]); | |
0051c76a | 1371 | set_immediate_dominator (CDI_DOMINATORS, new_bbs[0], e->src); |
dbfc1664 | 1372 | e = new_spec_edges[SE_LATCH]; |
1373 | } | |
6a606e3c | 1374 | |
dbfc1664 | 1375 | /* Record exit edge in this copy. */ |
08b7917c | 1376 | if (orig && bitmap_bit_p (wont_exit, j + 1)) |
f3c40e6d | 1377 | { |
1378 | if (to_remove) | |
f1f41a6c | 1379 | to_remove->safe_push (new_spec_edges[SE_ORIG]); |
7cef6c97 | 1380 | set_zero_probability (new_spec_edges[SE_ORIG]); |
1381 | ||
1382 | /* Scale the frequencies of the blocks dominated by the exit. */ | |
1383 | if (bbs_to_scale) | |
1384 | { | |
1385 | EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
1386 | { | |
1387 | scale_bbs_frequencies_int (new_bbs + i, 1, scale_after_exit, | |
1388 | REG_BR_PROB_BASE); | |
1389 | } | |
1390 | } | |
f3c40e6d | 1391 | } |
4c9e08a4 | 1392 | |
dbfc1664 | 1393 | /* Record the first copy in the control flow order if it is not |
1394 | the original loop (i.e. in case of peeling). */ | |
6a606e3c | 1395 | if (!first_active_latch) |
1396 | { | |
1397 | memcpy (first_active, new_bbs, n * sizeof (basic_block)); | |
c4d867e0 | 1398 | first_active_latch = new_bbs[n - 1]; |
6a606e3c | 1399 | } |
4c9e08a4 | 1400 | |
dbfc1664 | 1401 | /* Set counts and frequencies. */ |
1402 | if (flags & DLTHE_FLAG_UPDATE_FREQ) | |
6a606e3c | 1403 | { |
4d6b11ab | 1404 | scale_bbs_frequencies_int (new_bbs, n, scale_act, REG_BR_PROB_BASE); |
f9d4b7f4 | 1405 | scale_act = combine_probabilities (scale_act, scale_step[j]); |
6a606e3c | 1406 | } |
1407 | } | |
dbfc1664 | 1408 | free (new_bbs); |
1409 | free (orig_loops); | |
a0c938f0 | 1410 | |
f3c40e6d | 1411 | /* Record the exit edge in the original loop body, and update the frequencies. */ |
08b7917c | 1412 | if (orig && bitmap_bit_p (wont_exit, 0)) |
f3c40e6d | 1413 | { |
1414 | if (to_remove) | |
f1f41a6c | 1415 | to_remove->safe_push (orig); |
7cef6c97 | 1416 | set_zero_probability (orig); |
1417 | ||
1418 | /* Scale the frequencies of the blocks dominated by the exit. */ | |
1419 | if (bbs_to_scale) | |
1420 | { | |
1421 | EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi) | |
1422 | { | |
1423 | scale_bbs_frequencies_int (bbs + i, 1, scale_after_exit, | |
1424 | REG_BR_PROB_BASE); | |
1425 | } | |
1426 | } | |
f3c40e6d | 1427 | } |
1428 | ||
dbfc1664 | 1429 | /* Update the original loop. */ |
1430 | if (!is_latch) | |
0051c76a | 1431 | set_immediate_dominator (CDI_DOMINATORS, e->dest, e->src); |
6a606e3c | 1432 | if (flags & DLTHE_FLAG_UPDATE_FREQ) |
1433 | { | |
4d6b11ab | 1434 | scale_bbs_frequencies_int (bbs, n, scale_main, REG_BR_PROB_BASE); |
6a606e3c | 1435 | free (scale_step); |
1436 | } | |
6a606e3c | 1437 | |
dbfc1664 | 1438 | /* Update dominators of outer blocks if affected. */ |
6a606e3c | 1439 | for (i = 0; i < n; i++) |
1440 | { | |
3f9439d7 | 1441 | basic_block dominated, dom_bb; |
f1f41a6c | 1442 | vec<basic_block> dom_bbs; |
3f9439d7 | 1443 | unsigned j; |
6a606e3c | 1444 | |
1445 | bb = bbs[i]; | |
01020a5f | 1446 | bb->aux = 0; |
a9989fb4 | 1447 | |
3f9439d7 | 1448 | dom_bbs = get_dominated_by (CDI_DOMINATORS, bb); |
f1f41a6c | 1449 | FOR_EACH_VEC_ELT (dom_bbs, j, dominated) |
6a606e3c | 1450 | { |
6a606e3c | 1451 | if (flow_bb_inside_loop_p (loop, dominated)) |
1452 | continue; | |
1453 | dom_bb = nearest_common_dominator ( | |
0051c76a | 1454 | CDI_DOMINATORS, first_active[i], first_active_latch); |
a0c938f0 | 1455 | set_immediate_dominator (CDI_DOMINATORS, dominated, dom_bb); |
6a606e3c | 1456 | } |
f1f41a6c | 1457 | dom_bbs.release (); |
6a606e3c | 1458 | } |
1459 | free (first_active); | |
1460 | ||
1461 | free (bbs); | |
7cef6c97 | 1462 | BITMAP_FREE (bbs_to_scale); |
6a606e3c | 1463 | |
1464 | return true; | |
1465 | } | |
1466 | ||
5f5d4cd1 | 1467 | /* A callback for make_forwarder block, to redirect all edges except for |
1468 | MFB_KJ_EDGE to the entry part. E is the edge for that we should decide | |
1469 | whether to redirect it. */ | |
1470 | ||
7e0311ae | 1471 | edge mfb_kj_edge; |
1472 | bool | |
5f5d4cd1 | 1473 | mfb_keep_just (edge e) |
1474 | { | |
1475 | return e != mfb_kj_edge; | |
1476 | } | |
1477 | ||
e1ab7874 | 1478 | /* True when a candidate preheader BLOCK has predecessors from LOOP. */ |
1479 | ||
1480 | static bool | |
1481 | has_preds_from_loop (basic_block block, struct loop *loop) | |
1482 | { | |
1483 | edge e; | |
1484 | edge_iterator ei; | |
48e1416a | 1485 | |
e1ab7874 | 1486 | FOR_EACH_EDGE (e, ei, block->preds) |
1487 | if (e->src->loop_father == loop) | |
1488 | return true; | |
1489 | return false; | |
1490 | } | |
1491 | ||
862be747 | 1492 | /* Creates a pre-header for a LOOP. Returns newly created block. Unless |
1493 | CP_SIMPLE_PREHEADERS is set in FLAGS, we only force LOOP to have single | |
1494 | entry; otherwise we also force preheader block to have only one successor. | |
e1ab7874 | 1495 | When CP_FALLTHRU_PREHEADERS is set in FLAGS, we force the preheader block |
48e1416a | 1496 | to be a fallthru predecessor to the loop header and to have only |
e1ab7874 | 1497 | predecessors from outside of the loop. |
5f5d4cd1 | 1498 | The function also updates dominators. */ |
1499 | ||
7e0311ae | 1500 | basic_block |
0051c76a | 1501 | create_preheader (struct loop *loop, int flags) |
862be747 | 1502 | { |
1503 | edge e, fallthru; | |
1504 | basic_block dummy; | |
862be747 | 1505 | int nentry = 0; |
5f5d4cd1 | 1506 | bool irred = false; |
478166d0 | 1507 | bool latch_edge_was_fallthru; |
d8a0d6b8 | 1508 | edge one_succ_pred = NULL, single_entry = NULL; |
cd665a06 | 1509 | edge_iterator ei; |
862be747 | 1510 | |
cd665a06 | 1511 | FOR_EACH_EDGE (e, ei, loop->header->preds) |
862be747 | 1512 | { |
1513 | if (e->src == loop->latch) | |
1514 | continue; | |
5f5d4cd1 | 1515 | irred |= (e->flags & EDGE_IRREDUCIBLE_LOOP) != 0; |
862be747 | 1516 | nentry++; |
d8a0d6b8 | 1517 | single_entry = e; |
ea091dfd | 1518 | if (single_succ_p (e->src)) |
478166d0 | 1519 | one_succ_pred = e; |
862be747 | 1520 | } |
cc636d56 | 1521 | gcc_assert (nentry); |
862be747 | 1522 | if (nentry == 1) |
1523 | { | |
e1ab7874 | 1524 | bool need_forwarder_block = false; |
48e1416a | 1525 | |
e1ab7874 | 1526 | /* We do not allow entry block to be the loop preheader, since we |
4a6f9e19 | 1527 | cannot emit code there. */ |
34154e27 | 1528 | if (single_entry->src == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
e1ab7874 | 1529 | need_forwarder_block = true; |
1530 | else | |
1531 | { | |
1532 | /* If we want simple preheaders, also force the preheader to have | |
1533 | just a single successor. */ | |
1534 | if ((flags & CP_SIMPLE_PREHEADERS) | |
1535 | && !single_succ_p (single_entry->src)) | |
1536 | need_forwarder_block = true; | |
1537 | /* If we want fallthru preheaders, also create forwarder block when | |
1538 | preheader ends with a jump or has predecessors from loop. */ | |
1539 | else if ((flags & CP_FALLTHRU_PREHEADERS) | |
1540 | && (JUMP_P (BB_END (single_entry->src)) | |
1541 | || has_preds_from_loop (single_entry->src, loop))) | |
1542 | need_forwarder_block = true; | |
1543 | } | |
1544 | if (! need_forwarder_block) | |
862be747 | 1545 | return NULL; |
1546 | } | |
1547 | ||
5f5d4cd1 | 1548 | mfb_kj_edge = loop_latch_edge (loop); |
478166d0 | 1549 | latch_edge_was_fallthru = (mfb_kj_edge->flags & EDGE_FALLTHRU) != 0; |
88e6f696 | 1550 | fallthru = make_forwarder_block (loop->header, mfb_keep_just, NULL); |
862be747 | 1551 | dummy = fallthru->src; |
1552 | loop->header = fallthru->dest; | |
1553 | ||
478166d0 | 1554 | /* Try to be clever in placing the newly created preheader. The idea is to |
1555 | avoid breaking any "fallthruness" relationship between blocks. | |
1556 | ||
1557 | The preheader was created just before the header and all incoming edges | |
1558 | to the header were redirected to the preheader, except the latch edge. | |
1559 | So the only problematic case is when this latch edge was a fallthru | |
1560 | edge: it is not anymore after the preheader creation so we have broken | |
1561 | the fallthruness. We're therefore going to look for a better place. */ | |
1562 | if (latch_edge_was_fallthru) | |
1563 | { | |
1564 | if (one_succ_pred) | |
1565 | e = one_succ_pred; | |
1566 | else | |
1567 | e = EDGE_PRED (dummy, 0); | |
1568 | ||
1569 | move_block_after (dummy, e->src); | |
1570 | } | |
5f5d4cd1 | 1571 | |
5f5d4cd1 | 1572 | if (irred) |
862be747 | 1573 | { |
5f5d4cd1 | 1574 | dummy->flags |= BB_IRREDUCIBLE_LOOP; |
ea091dfd | 1575 | single_succ_edge (dummy)->flags |= EDGE_IRREDUCIBLE_LOOP; |
862be747 | 1576 | } |
1577 | ||
450d042a | 1578 | if (dump_file) |
1579 | fprintf (dump_file, "Created preheader block for loop %i\n", | |
862be747 | 1580 | loop->num); |
48e1416a | 1581 | |
e1ab7874 | 1582 | if (flags & CP_FALLTHRU_PREHEADERS) |
1583 | gcc_assert ((single_succ_edge (dummy)->flags & EDGE_FALLTHRU) | |
1584 | && !JUMP_P (BB_END (dummy))); | |
862be747 | 1585 | |
1586 | return dummy; | |
1587 | } | |
1588 | ||
7194de72 | 1589 | /* Create preheaders for each loop; for meaning of FLAGS see create_preheader. */ |
1590 | ||
862be747 | 1591 | void |
7194de72 | 1592 | create_preheaders (int flags) |
862be747 | 1593 | { |
17519ba0 | 1594 | struct loop *loop; |
1595 | ||
d8a0d6b8 | 1596 | if (!current_loops) |
1597 | return; | |
1598 | ||
f21d4d00 | 1599 | FOR_EACH_LOOP (loop, 0) |
17519ba0 | 1600 | create_preheader (loop, flags); |
f24ec26f | 1601 | loops_state_set (LOOPS_HAVE_PREHEADERS); |
862be747 | 1602 | } |
1603 | ||
7194de72 | 1604 | /* Forces all loop latches to have only single successor. */ |
1605 | ||
862be747 | 1606 | void |
7194de72 | 1607 | force_single_succ_latches (void) |
862be747 | 1608 | { |
862be747 | 1609 | struct loop *loop; |
1610 | edge e; | |
1611 | ||
f21d4d00 | 1612 | FOR_EACH_LOOP (loop, 0) |
862be747 | 1613 | { |
ea091dfd | 1614 | if (loop->latch != loop->header && single_succ_p (loop->latch)) |
862be747 | 1615 | continue; |
4c9e08a4 | 1616 | |
c6356c17 | 1617 | e = find_edge (loop->latch, loop->header); |
8ca4cf5b | 1618 | gcc_checking_assert (e != NULL); |
b536af40 | 1619 | |
88e6f696 | 1620 | split_edge (e); |
862be747 | 1621 | } |
f24ec26f | 1622 | loops_state_set (LOOPS_HAVE_SIMPLE_LATCHES); |
862be747 | 1623 | } |
1624 | ||
c50ae675 | 1625 | /* This function is called from loop_version. It splits the entry edge |
1626 | of the loop we want to version, adds the versioning condition, and | |
1627 | adjust the edges to the two versions of the loop appropriately. | |
1628 | e is an incoming edge. Returns the basic block containing the | |
1629 | condition. | |
1630 | ||
1631 | --- edge e ---- > [second_head] | |
1632 | ||
1633 | Split it and insert new conditional expression and adjust edges. | |
1634 | ||
1635 | --- edge e ---> [cond expr] ---> [first_head] | |
a0c938f0 | 1636 | | |
1637 | +---------> [second_head] | |
7cef6c97 | 1638 | |
1639 | THEN_PROB is the probability of then branch of the condition. */ | |
c50ae675 | 1640 | |
1641 | static basic_block | |
7cef6c97 | 1642 | lv_adjust_loop_entry_edge (basic_block first_head, basic_block second_head, |
1643 | edge e, void *cond_expr, unsigned then_prob) | |
c50ae675 | 1644 | { |
1645 | basic_block new_head = NULL; | |
1646 | edge e1; | |
1647 | ||
1648 | gcc_assert (e->dest == second_head); | |
1649 | ||
1650 | /* Split edge 'e'. This will create a new basic block, where we can | |
1651 | insert conditional expr. */ | |
1652 | new_head = split_edge (e); | |
1653 | ||
c50ae675 | 1654 | lv_add_condition_to_bb (first_head, second_head, new_head, |
1655 | cond_expr); | |
1656 | ||
ed49ee5b | 1657 | /* Don't set EDGE_TRUE_VALUE in RTL mode, as it's invalid there. */ |
7cef6c97 | 1658 | e = single_succ_edge (new_head); |
15b8fe07 | 1659 | e1 = make_edge (new_head, first_head, |
1660 | current_ir_type () == IR_GIMPLE ? EDGE_TRUE_VALUE : 0); | |
7cef6c97 | 1661 | e1->probability = then_prob; |
1662 | e->probability = REG_BR_PROB_BASE - then_prob; | |
f9d4b7f4 | 1663 | e1->count = apply_probability (e->count, e1->probability); |
1664 | e->count = apply_probability (e->count, e->probability); | |
7cef6c97 | 1665 | |
c50ae675 | 1666 | set_immediate_dominator (CDI_DOMINATORS, first_head, new_head); |
1667 | set_immediate_dominator (CDI_DOMINATORS, second_head, new_head); | |
1668 | ||
1669 | /* Adjust loop header phi nodes. */ | |
1670 | lv_adjust_loop_header_phi (first_head, second_head, new_head, e1); | |
1671 | ||
1672 | return new_head; | |
1673 | } | |
1674 | ||
1675 | /* Main entry point for Loop Versioning transformation. | |
a0c938f0 | 1676 | |
c4d867e0 | 1677 | This transformation given a condition and a loop, creates |
1678 | -if (condition) { loop_copy1 } else { loop_copy2 }, | |
1679 | where loop_copy1 is the loop transformed in one way, and loop_copy2 | |
1680 | is the loop transformed in another way (or unchanged). 'condition' | |
1681 | may be a run time test for things that were not resolved by static | |
1682 | analysis (overlapping ranges (anti-aliasing), alignment, etc.). | |
1683 | ||
7cef6c97 | 1684 | THEN_PROB is the probability of the then edge of the if. THEN_SCALE |
1685 | is the ratio by that the frequencies in the original loop should | |
1686 | be scaled. ELSE_SCALE is the ratio by that the frequencies in the | |
1687 | new loop should be scaled. | |
48e1416a | 1688 | |
c4d867e0 | 1689 | If PLACE_AFTER is true, we place the new loop after LOOP in the |
1690 | instruction stream, otherwise it is placed before LOOP. */ | |
c50ae675 | 1691 | |
1692 | struct loop * | |
7194de72 | 1693 | loop_version (struct loop *loop, |
c4d867e0 | 1694 | void *cond_expr, basic_block *condition_bb, |
7cef6c97 | 1695 | unsigned then_prob, unsigned then_scale, unsigned else_scale, |
c4d867e0 | 1696 | bool place_after) |
c50ae675 | 1697 | { |
1698 | basic_block first_head, second_head; | |
dce58e66 | 1699 | edge entry, latch_edge, true_edge, false_edge; |
c50ae675 | 1700 | int irred_flag; |
1701 | struct loop *nloop; | |
c4d867e0 | 1702 | basic_block cond_bb; |
c50ae675 | 1703 | |
c50ae675 | 1704 | /* Record entry and latch edges for the loop */ |
1705 | entry = loop_preheader_edge (loop); | |
1706 | irred_flag = entry->flags & EDGE_IRREDUCIBLE_LOOP; | |
1707 | entry->flags &= ~EDGE_IRREDUCIBLE_LOOP; | |
a0c938f0 | 1708 | |
c50ae675 | 1709 | /* Note down head of loop as first_head. */ |
1710 | first_head = entry->dest; | |
1711 | ||
1712 | /* Duplicate loop. */ | |
7194de72 | 1713 | if (!cfg_hook_duplicate_loop_to_header_edge (loop, entry, 1, |
f3c40e6d | 1714 | NULL, NULL, NULL, 0)) |
48b6dfd8 | 1715 | { |
1716 | entry->flags |= irred_flag; | |
1717 | return NULL; | |
1718 | } | |
c50ae675 | 1719 | |
1720 | /* After duplication entry edge now points to new loop head block. | |
1721 | Note down new head as second_head. */ | |
1722 | second_head = entry->dest; | |
1723 | ||
1724 | /* Split loop entry edge and insert new block with cond expr. */ | |
c4d867e0 | 1725 | cond_bb = lv_adjust_loop_entry_edge (first_head, second_head, |
7cef6c97 | 1726 | entry, cond_expr, then_prob); |
c4d867e0 | 1727 | if (condition_bb) |
1728 | *condition_bb = cond_bb; | |
1729 | ||
1730 | if (!cond_bb) | |
c50ae675 | 1731 | { |
1732 | entry->flags |= irred_flag; | |
1733 | return NULL; | |
1734 | } | |
1735 | ||
01020a5f | 1736 | latch_edge = single_succ_edge (get_bb_copy (loop->latch)); |
a0c938f0 | 1737 | |
c4d867e0 | 1738 | extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); |
7194de72 | 1739 | nloop = loopify (latch_edge, |
01020a5f | 1740 | single_pred_edge (get_bb_copy (loop->header)), |
c4d867e0 | 1741 | cond_bb, true_edge, false_edge, |
7cef6c97 | 1742 | false /* Do not redirect all edges. */, |
1743 | then_scale, else_scale); | |
c50ae675 | 1744 | |
efa7c5bd | 1745 | copy_loop_info (loop, nloop); |
1746 | ||
a0c938f0 | 1747 | /* loopify redirected latch_edge. Update its PENDING_STMTS. */ |
c50ae675 | 1748 | lv_flush_pending_stmts (latch_edge); |
1749 | ||
a0c938f0 | 1750 | /* loopify redirected condition_bb's succ edge. Update its PENDING_STMTS. */ |
c4d867e0 | 1751 | extract_cond_bb_edges (cond_bb, &true_edge, &false_edge); |
c50ae675 | 1752 | lv_flush_pending_stmts (false_edge); |
1753 | /* Adjust irreducible flag. */ | |
1754 | if (irred_flag) | |
1755 | { | |
c4d867e0 | 1756 | cond_bb->flags |= BB_IRREDUCIBLE_LOOP; |
c50ae675 | 1757 | loop_preheader_edge (loop)->flags |= EDGE_IRREDUCIBLE_LOOP; |
1758 | loop_preheader_edge (nloop)->flags |= EDGE_IRREDUCIBLE_LOOP; | |
c4d867e0 | 1759 | single_pred_edge (cond_bb)->flags |= EDGE_IRREDUCIBLE_LOOP; |
1760 | } | |
1761 | ||
1762 | if (place_after) | |
1763 | { | |
1764 | basic_block *bbs = get_loop_body_in_dom_order (nloop), after; | |
1765 | unsigned i; | |
1766 | ||
1767 | after = loop->latch; | |
1768 | ||
1769 | for (i = 0; i < nloop->num_nodes; i++) | |
1770 | { | |
1771 | move_block_after (bbs[i], after); | |
1772 | after = bbs[i]; | |
1773 | } | |
1774 | free (bbs); | |
c50ae675 | 1775 | } |
1776 | ||
f0b5f617 | 1777 | /* At this point condition_bb is loop preheader with two successors, |
1778 | first_head and second_head. Make sure that loop preheader has only | |
c50ae675 | 1779 | one successor. */ |
88e6f696 | 1780 | split_edge (loop_preheader_edge (loop)); |
1781 | split_edge (loop_preheader_edge (nloop)); | |
c50ae675 | 1782 | |
1783 | return nloop; | |
1784 | } |