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c9784e6d | 1 | /* CFG cleanup for trees. |
d1e082c2 | 2 | Copyright (C) 2001-2013 Free Software Foundation, Inc. |
c9784e6d KH |
3 | |
4 | This file is part of GCC. | |
5 | ||
6 | GCC is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
9dcd6f09 | 8 | the Free Software Foundation; either version 3, or (at your option) |
c9784e6d KH |
9 | any later version. |
10 | ||
11 | GCC is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
17 | along with GCC; see the file COPYING3. If not see |
18 | <http://www.gnu.org/licenses/>. */ | |
c9784e6d KH |
19 | |
20 | #include "config.h" | |
21 | #include "system.h" | |
22 | #include "coretypes.h" | |
23 | #include "tm.h" | |
24 | #include "tree.h" | |
c9784e6d | 25 | #include "tm_p.h" |
c9784e6d | 26 | #include "basic-block.h" |
718f9c0f | 27 | #include "diagnostic-core.h" |
c9784e6d KH |
28 | #include "flags.h" |
29 | #include "function.h" | |
c9784e6d KH |
30 | #include "ggc.h" |
31 | #include "langhooks.h" | |
442b4905 AM |
32 | #include "gimple.h" |
33 | #include "gimple-ssa.h" | |
34 | #include "tree-cfg.h" | |
35 | #include "tree-phinodes.h" | |
36 | #include "ssa-iterators.h" | |
37 | #include "tree-ssanames.h" | |
38 | #include "tree-ssa-loop.h" | |
39 | #include "tree-dfa.h" | |
7a300452 | 40 | #include "tree-ssa.h" |
c9784e6d | 41 | #include "tree-pass.h" |
c9784e6d KH |
42 | #include "except.h" |
43 | #include "cfgloop.h" | |
c9784e6d KH |
44 | #include "hashtab.h" |
45 | #include "tree-ssa-propagate.h" | |
17684618 | 46 | #include "tree-scalar-evolution.h" |
c9784e6d | 47 | |
672987e8 ZD |
48 | /* The set of blocks in that at least one of the following changes happened: |
49 | -- the statement at the end of the block was changed | |
50 | -- the block was newly created | |
51 | -- the set of the predecessors of the block changed | |
52 | -- the set of the successors of the block changed | |
53 | ??? Maybe we could track these changes separately, since they determine | |
54 | what cleanups it makes sense to try on the block. */ | |
55 | bitmap cfgcleanup_altered_bbs; | |
56 | ||
c9784e6d KH |
57 | /* Remove any fallthru edge from EV. Return true if an edge was removed. */ |
58 | ||
59 | static bool | |
9771b263 | 60 | remove_fallthru_edge (vec<edge, va_gc> *ev) |
c9784e6d KH |
61 | { |
62 | edge_iterator ei; | |
63 | edge e; | |
64 | ||
65 | FOR_EACH_EDGE (e, ei, ev) | |
66 | if ((e->flags & EDGE_FALLTHRU) != 0) | |
67 | { | |
0107dca2 RB |
68 | if (e->flags & EDGE_COMPLEX) |
69 | e->flags &= ~EDGE_FALLTHRU; | |
70 | else | |
71 | remove_edge_and_dominated_blocks (e); | |
c9784e6d KH |
72 | return true; |
73 | } | |
74 | return false; | |
75 | } | |
76 | ||
726a989a | 77 | |
c9784e6d KH |
78 | /* Disconnect an unreachable block in the control expression starting |
79 | at block BB. */ | |
80 | ||
81 | static bool | |
726a989a | 82 | cleanup_control_expr_graph (basic_block bb, gimple_stmt_iterator gsi) |
c9784e6d KH |
83 | { |
84 | edge taken_edge; | |
85 | bool retval = false; | |
726a989a RB |
86 | gimple stmt = gsi_stmt (gsi); |
87 | tree val; | |
c9784e6d KH |
88 | |
89 | if (!single_succ_p (bb)) | |
90 | { | |
91 | edge e; | |
92 | edge_iterator ei; | |
6ac01510 | 93 | bool warned; |
37530014 | 94 | location_t loc; |
6ac01510 ILT |
95 | |
96 | fold_defer_overflow_warnings (); | |
37530014 RG |
97 | loc = gimple_location (stmt); |
98 | switch (gimple_code (stmt)) | |
99 | { | |
100 | case GIMPLE_COND: | |
fea4ea73 EB |
101 | val = fold_binary_loc (loc, gimple_cond_code (stmt), |
102 | boolean_type_node, | |
103 | gimple_cond_lhs (stmt), | |
104 | gimple_cond_rhs (stmt)); | |
105 | break; | |
37530014 RG |
106 | |
107 | case GIMPLE_SWITCH: | |
108 | val = gimple_switch_index (stmt); | |
109 | break; | |
110 | ||
111 | default: | |
112 | val = NULL_TREE; | |
113 | } | |
c9784e6d KH |
114 | taken_edge = find_taken_edge (bb, val); |
115 | if (!taken_edge) | |
6ac01510 ILT |
116 | { |
117 | fold_undefer_and_ignore_overflow_warnings (); | |
118 | return false; | |
119 | } | |
c9784e6d KH |
120 | |
121 | /* Remove all the edges except the one that is always executed. */ | |
6ac01510 | 122 | warned = false; |
c9784e6d KH |
123 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
124 | { | |
125 | if (e != taken_edge) | |
126 | { | |
6ac01510 ILT |
127 | if (!warned) |
128 | { | |
129 | fold_undefer_overflow_warnings | |
726a989a | 130 | (true, stmt, WARN_STRICT_OVERFLOW_CONDITIONAL); |
6ac01510 ILT |
131 | warned = true; |
132 | } | |
133 | ||
c9784e6d KH |
134 | taken_edge->probability += e->probability; |
135 | taken_edge->count += e->count; | |
672987e8 | 136 | remove_edge_and_dominated_blocks (e); |
c9784e6d KH |
137 | retval = true; |
138 | } | |
139 | else | |
140 | ei_next (&ei); | |
141 | } | |
6ac01510 ILT |
142 | if (!warned) |
143 | fold_undefer_and_ignore_overflow_warnings (); | |
c9784e6d KH |
144 | if (taken_edge->probability > REG_BR_PROB_BASE) |
145 | taken_edge->probability = REG_BR_PROB_BASE; | |
146 | } | |
147 | else | |
148 | taken_edge = single_succ_edge (bb); | |
149 | ||
672987e8 | 150 | bitmap_set_bit (cfgcleanup_altered_bbs, bb->index); |
726a989a | 151 | gsi_remove (&gsi, true); |
c9784e6d KH |
152 | taken_edge->flags = EDGE_FALLTHRU; |
153 | ||
c9784e6d KH |
154 | return retval; |
155 | } | |
156 | ||
672987e8 ZD |
157 | /* Try to remove superfluous control structures in basic block BB. Returns |
158 | true if anything changes. */ | |
c9784e6d KH |
159 | |
160 | static bool | |
672987e8 | 161 | cleanup_control_flow_bb (basic_block bb) |
c9784e6d | 162 | { |
726a989a | 163 | gimple_stmt_iterator gsi; |
c9784e6d | 164 | bool retval = false; |
726a989a | 165 | gimple stmt; |
c9784e6d | 166 | |
672987e8 ZD |
167 | /* If the last statement of the block could throw and now cannot, |
168 | we need to prune cfg. */ | |
726a989a | 169 | retval |= gimple_purge_dead_eh_edges (bb); |
672987e8 | 170 | |
726a989a RB |
171 | gsi = gsi_last_bb (bb); |
172 | if (gsi_end_p (gsi)) | |
672987e8 ZD |
173 | return retval; |
174 | ||
726a989a | 175 | stmt = gsi_stmt (gsi); |
672987e8 | 176 | |
726a989a RB |
177 | if (gimple_code (stmt) == GIMPLE_COND |
178 | || gimple_code (stmt) == GIMPLE_SWITCH) | |
179 | retval |= cleanup_control_expr_graph (bb, gsi); | |
180 | else if (gimple_code (stmt) == GIMPLE_GOTO | |
181 | && TREE_CODE (gimple_goto_dest (stmt)) == ADDR_EXPR | |
182 | && (TREE_CODE (TREE_OPERAND (gimple_goto_dest (stmt), 0)) | |
672987e8 | 183 | == LABEL_DECL)) |
c9784e6d | 184 | { |
726a989a RB |
185 | /* If we had a computed goto which has a compile-time determinable |
186 | destination, then we can eliminate the goto. */ | |
672987e8 ZD |
187 | edge e; |
188 | tree label; | |
189 | edge_iterator ei; | |
190 | basic_block target_block; | |
c9784e6d | 191 | |
672987e8 ZD |
192 | /* First look at all the outgoing edges. Delete any outgoing |
193 | edges which do not go to the right block. For the one | |
194 | edge which goes to the right block, fix up its flags. */ | |
726a989a | 195 | label = TREE_OPERAND (gimple_goto_dest (stmt), 0); |
672987e8 ZD |
196 | target_block = label_to_block (label); |
197 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) | |
c9784e6d | 198 | { |
672987e8 ZD |
199 | if (e->dest != target_block) |
200 | remove_edge_and_dominated_blocks (e); | |
201 | else | |
c9784e6d | 202 | { |
672987e8 ZD |
203 | /* Turn off the EDGE_ABNORMAL flag. */ |
204 | e->flags &= ~EDGE_ABNORMAL; | |
c9784e6d | 205 | |
672987e8 ZD |
206 | /* And set EDGE_FALLTHRU. */ |
207 | e->flags |= EDGE_FALLTHRU; | |
208 | ei_next (&ei); | |
209 | } | |
c9784e6d KH |
210 | } |
211 | ||
672987e8 ZD |
212 | bitmap_set_bit (cfgcleanup_altered_bbs, bb->index); |
213 | bitmap_set_bit (cfgcleanup_altered_bbs, target_block->index); | |
214 | ||
215 | /* Remove the GOTO_EXPR as it is not needed. The CFG has all the | |
216 | relevant information we need. */ | |
726a989a | 217 | gsi_remove (&gsi, true); |
672987e8 | 218 | retval = true; |
c9784e6d | 219 | } |
672987e8 ZD |
220 | |
221 | /* Check for indirect calls that have been turned into | |
222 | noreturn calls. */ | |
726a989a RB |
223 | else if (is_gimple_call (stmt) |
224 | && gimple_call_noreturn_p (stmt) | |
225 | && remove_fallthru_edge (bb->succs)) | |
672987e8 ZD |
226 | retval = true; |
227 | ||
c9784e6d KH |
228 | return retval; |
229 | } | |
230 | ||
231 | /* Return true if basic block BB does nothing except pass control | |
232 | flow to another block and that we can safely insert a label at | |
233 | the start of the successor block. | |
234 | ||
235 | As a precondition, we require that BB be not equal to | |
236 | ENTRY_BLOCK_PTR. */ | |
237 | ||
238 | static bool | |
239 | tree_forwarder_block_p (basic_block bb, bool phi_wanted) | |
240 | { | |
726a989a | 241 | gimple_stmt_iterator gsi; |
f99fcb3b | 242 | location_t locus; |
c9784e6d KH |
243 | |
244 | /* BB must have a single outgoing edge. */ | |
245 | if (single_succ_p (bb) != 1 | |
246 | /* If PHI_WANTED is false, BB must not have any PHI nodes. | |
247 | Otherwise, BB must have PHI nodes. */ | |
726a989a | 248 | || gimple_seq_empty_p (phi_nodes (bb)) == phi_wanted |
c9784e6d KH |
249 | /* BB may not be a predecessor of EXIT_BLOCK_PTR. */ |
250 | || single_succ (bb) == EXIT_BLOCK_PTR | |
251 | /* Nor should this be an infinite loop. */ | |
252 | || single_succ (bb) == bb | |
253 | /* BB may not have an abnormal outgoing edge. */ | |
254 | || (single_succ_edge (bb)->flags & EDGE_ABNORMAL)) | |
255 | return false; | |
256 | ||
77a74ed7 | 257 | gcc_checking_assert (bb != ENTRY_BLOCK_PTR); |
c9784e6d | 258 | |
f99fcb3b JJ |
259 | locus = single_succ_edge (bb)->goto_locus; |
260 | ||
1d65f45c RH |
261 | /* There should not be an edge coming from entry, or an EH edge. */ |
262 | { | |
263 | edge_iterator ei; | |
264 | edge e; | |
265 | ||
266 | FOR_EACH_EDGE (e, ei, bb->preds) | |
267 | if (e->src == ENTRY_BLOCK_PTR || (e->flags & EDGE_EH)) | |
268 | return false; | |
f99fcb3b JJ |
269 | /* If goto_locus of any of the edges differs, prevent removing |
270 | the forwarder block for -O0. */ | |
271 | else if (optimize == 0 && e->goto_locus != locus) | |
272 | return false; | |
1d65f45c RH |
273 | } |
274 | ||
c9784e6d KH |
275 | /* Now walk through the statements backward. We can ignore labels, |
276 | anything else means this is not a forwarder block. */ | |
726a989a | 277 | for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi)) |
c9784e6d | 278 | { |
726a989a | 279 | gimple stmt = gsi_stmt (gsi); |
c9784e6d | 280 | |
726a989a | 281 | switch (gimple_code (stmt)) |
c9784e6d | 282 | { |
726a989a RB |
283 | case GIMPLE_LABEL: |
284 | if (DECL_NONLOCAL (gimple_label_label (stmt))) | |
c9784e6d | 285 | return false; |
f99fcb3b JJ |
286 | if (optimize == 0 && gimple_location (stmt) != locus) |
287 | return false; | |
c9784e6d KH |
288 | break; |
289 | ||
b5b8b0ac AO |
290 | /* ??? For now, hope there's a corresponding debug |
291 | assignment at the destination. */ | |
292 | case GIMPLE_DEBUG: | |
293 | break; | |
294 | ||
c9784e6d KH |
295 | default: |
296 | return false; | |
297 | } | |
298 | } | |
299 | ||
c9784e6d KH |
300 | if (current_loops) |
301 | { | |
302 | basic_block dest; | |
303 | /* Protect loop latches, headers and preheaders. */ | |
304 | if (bb->loop_father->header == bb) | |
305 | return false; | |
306 | dest = EDGE_SUCC (bb, 0)->dest; | |
307 | ||
308 | if (dest->loop_father->header == dest) | |
309 | return false; | |
310 | } | |
c9784e6d KH |
311 | return true; |
312 | } | |
313 | ||
c9784e6d KH |
314 | /* If all the PHI nodes in DEST have alternatives for E1 and E2 and |
315 | those alternatives are equal in each of the PHI nodes, then return | |
316 | true, else return false. */ | |
317 | ||
318 | static bool | |
319 | phi_alternatives_equal (basic_block dest, edge e1, edge e2) | |
320 | { | |
321 | int n1 = e1->dest_idx; | |
322 | int n2 = e2->dest_idx; | |
726a989a | 323 | gimple_stmt_iterator gsi; |
c9784e6d | 324 | |
726a989a | 325 | for (gsi = gsi_start_phis (dest); !gsi_end_p (gsi); gsi_next (&gsi)) |
c9784e6d | 326 | { |
726a989a RB |
327 | gimple phi = gsi_stmt (gsi); |
328 | tree val1 = gimple_phi_arg_def (phi, n1); | |
329 | tree val2 = gimple_phi_arg_def (phi, n2); | |
c9784e6d KH |
330 | |
331 | gcc_assert (val1 != NULL_TREE); | |
332 | gcc_assert (val2 != NULL_TREE); | |
333 | ||
334 | if (!operand_equal_for_phi_arg_p (val1, val2)) | |
335 | return false; | |
336 | } | |
337 | ||
338 | return true; | |
339 | } | |
340 | ||
672987e8 | 341 | /* Removes forwarder block BB. Returns false if this failed. */ |
c9784e6d KH |
342 | |
343 | static bool | |
672987e8 | 344 | remove_forwarder_block (basic_block bb) |
c9784e6d KH |
345 | { |
346 | edge succ = single_succ_edge (bb), e, s; | |
347 | basic_block dest = succ->dest; | |
726a989a | 348 | gimple label; |
c9784e6d | 349 | edge_iterator ei; |
726a989a | 350 | gimple_stmt_iterator gsi, gsi_to; |
70235ab9 | 351 | bool can_move_debug_stmts; |
c9784e6d KH |
352 | |
353 | /* We check for infinite loops already in tree_forwarder_block_p. | |
354 | However it may happen that the infinite loop is created | |
355 | afterwards due to removal of forwarders. */ | |
356 | if (dest == bb) | |
357 | return false; | |
358 | ||
28e5ca15 RB |
359 | /* If the destination block consists of a nonlocal label or is a |
360 | EH landing pad, do not merge it. */ | |
c9784e6d KH |
361 | label = first_stmt (dest); |
362 | if (label | |
726a989a | 363 | && gimple_code (label) == GIMPLE_LABEL |
28e5ca15 RB |
364 | && (DECL_NONLOCAL (gimple_label_label (label)) |
365 | || EH_LANDING_PAD_NR (gimple_label_label (label)) != 0)) | |
c9784e6d KH |
366 | return false; |
367 | ||
368 | /* If there is an abnormal edge to basic block BB, but not into | |
369 | dest, problems might occur during removal of the phi node at out | |
370 | of ssa due to overlapping live ranges of registers. | |
371 | ||
372 | If there is an abnormal edge in DEST, the problems would occur | |
373 | anyway since cleanup_dead_labels would then merge the labels for | |
374 | two different eh regions, and rest of exception handling code | |
375 | does not like it. | |
376 | ||
377 | So if there is an abnormal edge to BB, proceed only if there is | |
378 | no abnormal edge to DEST and there are no phi nodes in DEST. */ | |
31ff2426 NF |
379 | if (bb_has_abnormal_pred (bb) |
380 | && (bb_has_abnormal_pred (dest) | |
1197e789 RG |
381 | || !gimple_seq_empty_p (phi_nodes (dest)))) |
382 | return false; | |
c9784e6d KH |
383 | |
384 | /* If there are phi nodes in DEST, and some of the blocks that are | |
385 | predecessors of BB are also predecessors of DEST, check that the | |
386 | phi node arguments match. */ | |
726a989a | 387 | if (!gimple_seq_empty_p (phi_nodes (dest))) |
c9784e6d KH |
388 | { |
389 | FOR_EACH_EDGE (e, ei, bb->preds) | |
390 | { | |
391 | s = find_edge (e->src, dest); | |
392 | if (!s) | |
393 | continue; | |
394 | ||
395 | if (!phi_alternatives_equal (dest, succ, s)) | |
396 | return false; | |
397 | } | |
398 | } | |
399 | ||
dc764d10 | 400 | can_move_debug_stmts = MAY_HAVE_DEBUG_STMTS && single_pred_p (dest); |
70235ab9 | 401 | |
c9784e6d KH |
402 | /* Redirect the edges. */ |
403 | for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); ) | |
404 | { | |
672987e8 ZD |
405 | bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index); |
406 | ||
c9784e6d KH |
407 | if (e->flags & EDGE_ABNORMAL) |
408 | { | |
409 | /* If there is an abnormal edge, redirect it anyway, and | |
410 | move the labels to the new block to make it legal. */ | |
411 | s = redirect_edge_succ_nodup (e, dest); | |
412 | } | |
413 | else | |
414 | s = redirect_edge_and_branch (e, dest); | |
415 | ||
416 | if (s == e) | |
417 | { | |
418 | /* Create arguments for the phi nodes, since the edge was not | |
419 | here before. */ | |
726a989a RB |
420 | for (gsi = gsi_start_phis (dest); |
421 | !gsi_end_p (gsi); | |
422 | gsi_next (&gsi)) | |
423 | { | |
424 | gimple phi = gsi_stmt (gsi); | |
f5045c96 | 425 | source_location l = gimple_phi_arg_location_from_edge (phi, succ); |
2724573f RB |
426 | tree def = gimple_phi_arg_def (phi, succ->dest_idx); |
427 | add_phi_arg (phi, unshare_expr (def), s, l); | |
726a989a | 428 | } |
c9784e6d | 429 | } |
c9784e6d KH |
430 | } |
431 | ||
1197e789 RG |
432 | /* Move nonlocal labels and computed goto targets as well as user |
433 | defined labels and labels with an EH landing pad number to the | |
434 | new block, so that the redirection of the abnormal edges works, | |
435 | jump targets end up in a sane place and debug information for | |
436 | labels is retained. */ | |
437 | gsi_to = gsi_start_bb (dest); | |
438 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) | |
439 | { | |
440 | tree decl; | |
441 | label = gsi_stmt (gsi); | |
442 | if (is_gimple_debug (label)) | |
443 | break; | |
444 | decl = gimple_label_label (label); | |
445 | if (EH_LANDING_PAD_NR (decl) != 0 | |
446 | || DECL_NONLOCAL (decl) | |
447 | || FORCED_LABEL (decl) | |
448 | || !DECL_ARTIFICIAL (decl)) | |
449 | { | |
450 | gsi_remove (&gsi, false); | |
451 | gsi_insert_before (&gsi_to, label, GSI_SAME_STMT); | |
452 | } | |
453 | else | |
454 | gsi_next (&gsi); | |
455 | } | |
456 | ||
dc764d10 | 457 | /* Move debug statements if the destination has a single predecessor. */ |
70235ab9 | 458 | if (can_move_debug_stmts) |
c9784e6d | 459 | { |
1197e789 RG |
460 | gsi_to = gsi_after_labels (dest); |
461 | for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); ) | |
c9784e6d | 462 | { |
70235ab9 JJ |
463 | gimple debug = gsi_stmt (gsi); |
464 | if (!is_gimple_debug (debug)) | |
1197e789 | 465 | break; |
726a989a | 466 | gsi_remove (&gsi, false); |
70235ab9 | 467 | gsi_insert_before (&gsi_to, debug, GSI_SAME_STMT); |
c9784e6d KH |
468 | } |
469 | } | |
470 | ||
672987e8 ZD |
471 | bitmap_set_bit (cfgcleanup_altered_bbs, dest->index); |
472 | ||
c9784e6d KH |
473 | /* Update the dominators. */ |
474 | if (dom_info_available_p (CDI_DOMINATORS)) | |
475 | { | |
476 | basic_block dom, dombb, domdest; | |
477 | ||
478 | dombb = get_immediate_dominator (CDI_DOMINATORS, bb); | |
479 | domdest = get_immediate_dominator (CDI_DOMINATORS, dest); | |
480 | if (domdest == bb) | |
481 | { | |
482 | /* Shortcut to avoid calling (relatively expensive) | |
483 | nearest_common_dominator unless necessary. */ | |
484 | dom = dombb; | |
485 | } | |
486 | else | |
487 | dom = nearest_common_dominator (CDI_DOMINATORS, domdest, dombb); | |
488 | ||
489 | set_immediate_dominator (CDI_DOMINATORS, dest, dom); | |
490 | } | |
491 | ||
492 | /* And kill the forwarder block. */ | |
493 | delete_basic_block (bb); | |
494 | ||
495 | return true; | |
496 | } | |
497 | ||
566d09ef JH |
498 | /* STMT is a call that has been discovered noreturn. Fixup the CFG |
499 | and remove LHS. Return true if something changed. */ | |
500 | ||
501 | bool | |
502 | fixup_noreturn_call (gimple stmt) | |
503 | { | |
504 | basic_block bb = gimple_bb (stmt); | |
505 | bool changed = false; | |
506 | ||
507 | if (gimple_call_builtin_p (stmt, BUILT_IN_RETURN)) | |
508 | return false; | |
509 | ||
510 | /* First split basic block if stmt is not last. */ | |
511 | if (stmt != gsi_stmt (gsi_last_bb (bb))) | |
512 | split_block (bb, stmt); | |
513 | ||
514 | changed |= remove_fallthru_edge (bb->succs); | |
515 | ||
516 | /* If there is LHS, remove it. */ | |
517 | if (gimple_call_lhs (stmt)) | |
518 | { | |
519 | tree op = gimple_call_lhs (stmt); | |
520 | gimple_call_set_lhs (stmt, NULL_TREE); | |
02d635a2 | 521 | |
acb6411a | 522 | /* We need to remove SSA name to avoid checking errors. |
566d09ef | 523 | All uses are dominated by the noreturn and thus will |
02d635a2 JH |
524 | be removed afterwards. |
525 | We proactively remove affected non-PHI statements to avoid | |
526 | fixup_cfg from trying to update them and crashing. */ | |
566d09ef JH |
527 | if (TREE_CODE (op) == SSA_NAME) |
528 | { | |
529 | use_operand_p use_p; | |
530 | imm_use_iterator iter; | |
531 | gimple use_stmt; | |
02d635a2 JH |
532 | bitmap_iterator bi; |
533 | unsigned int bb_index; | |
534 | ||
535 | bitmap blocks = BITMAP_ALLOC (NULL); | |
566d09ef JH |
536 | |
537 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, op) | |
02d635a2 JH |
538 | { |
539 | if (gimple_code (use_stmt) != GIMPLE_PHI) | |
540 | bitmap_set_bit (blocks, gimple_bb (use_stmt)->index); | |
541 | else | |
542 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
543 | SET_USE (use_p, error_mark_node); | |
544 | } | |
545 | EXECUTE_IF_SET_IN_BITMAP (blocks, 0, bb_index, bi) | |
546 | delete_basic_block (BASIC_BLOCK (bb_index)); | |
547 | BITMAP_FREE (blocks); | |
548 | release_ssa_name (op); | |
566d09ef JH |
549 | } |
550 | update_stmt (stmt); | |
551 | changed = true; | |
552 | } | |
8ba0479e JJ |
553 | /* Similarly remove VDEF if there is any. */ |
554 | else if (gimple_vdef (stmt)) | |
555 | update_stmt (stmt); | |
566d09ef JH |
556 | return changed; |
557 | } | |
558 | ||
559 | ||
672987e8 ZD |
560 | /* Split basic blocks on calls in the middle of a basic block that are now |
561 | known not to return, and remove the unreachable code. */ | |
c9784e6d KH |
562 | |
563 | static bool | |
672987e8 | 564 | split_bbs_on_noreturn_calls (void) |
c9784e6d | 565 | { |
c9784e6d | 566 | bool changed = false; |
726a989a | 567 | gimple stmt; |
672987e8 | 568 | basic_block bb; |
c9784e6d | 569 | |
672987e8 ZD |
570 | /* Detect cases where a mid-block call is now known not to return. */ |
571 | if (cfun->gimple_df) | |
9771b263 | 572 | while (vec_safe_length (MODIFIED_NORETURN_CALLS (cfun))) |
672987e8 | 573 | { |
9771b263 | 574 | stmt = MODIFIED_NORETURN_CALLS (cfun)->pop (); |
726a989a | 575 | bb = gimple_bb (stmt); |
4d731f17 JJ |
576 | /* BB might be deleted at this point, so verify first |
577 | BB is present in the cfg. */ | |
672987e8 | 578 | if (bb == NULL |
4d731f17 | 579 | || bb->index < NUM_FIXED_BLOCKS |
30f1e6de | 580 | || bb->index >= last_basic_block |
4d731f17 | 581 | || BASIC_BLOCK (bb->index) != bb |
726a989a | 582 | || !gimple_call_noreturn_p (stmt)) |
672987e8 ZD |
583 | continue; |
584 | ||
566d09ef | 585 | changed |= fixup_noreturn_call (stmt); |
672987e8 | 586 | } |
c9784e6d | 587 | |
c9784e6d KH |
588 | return changed; |
589 | } | |
590 | ||
672987e8 ZD |
591 | /* Tries to cleanup cfg in basic block BB. Returns true if anything |
592 | changes. */ | |
c9784e6d | 593 | |
89e80dd4 | 594 | static bool |
672987e8 | 595 | cleanup_tree_cfg_bb (basic_block bb) |
c9784e6d | 596 | { |
65e7bfe3 | 597 | bool retval = cleanup_control_flow_bb (bb); |
b8698a0f | 598 | |
f99fcb3b | 599 | if (tree_forwarder_block_p (bb, false) |
672987e8 ZD |
600 | && remove_forwarder_block (bb)) |
601 | return true; | |
c9784e6d | 602 | |
89e80dd4 DN |
603 | /* Merging the blocks may create new opportunities for folding |
604 | conditional branches (due to the elimination of single-valued PHI | |
605 | nodes). */ | |
672987e8 ZD |
606 | if (single_succ_p (bb) |
607 | && can_merge_blocks_p (bb, single_succ (bb))) | |
608 | { | |
609 | merge_blocks (bb, single_succ (bb)); | |
610 | return true; | |
611 | } | |
612 | ||
613 | return retval; | |
614 | } | |
615 | ||
616 | /* Iterate the cfg cleanups, while anything changes. */ | |
617 | ||
618 | static bool | |
619 | cleanup_tree_cfg_1 (void) | |
620 | { | |
621 | bool retval = false; | |
622 | basic_block bb; | |
623 | unsigned i, n; | |
624 | ||
625 | retval |= split_bbs_on_noreturn_calls (); | |
626 | ||
627 | /* Prepare the worklists of altered blocks. */ | |
628 | cfgcleanup_altered_bbs = BITMAP_ALLOC (NULL); | |
629 | ||
630 | /* During forwarder block cleanup, we may redirect edges out of | |
631 | SWITCH_EXPRs, which can get expensive. So we want to enable | |
632 | recording of edge to CASE_LABEL_EXPR. */ | |
633 | start_recording_case_labels (); | |
89e80dd4 | 634 | |
672987e8 ZD |
635 | /* Start by iterating over all basic blocks. We cannot use FOR_EACH_BB, |
636 | since the basic blocks may get removed. */ | |
637 | n = last_basic_block; | |
638 | for (i = NUM_FIXED_BLOCKS; i < n; i++) | |
639 | { | |
640 | bb = BASIC_BLOCK (i); | |
641 | if (bb) | |
642 | retval |= cleanup_tree_cfg_bb (bb); | |
643 | } | |
644 | ||
645 | /* Now process the altered blocks, as long as any are available. */ | |
646 | while (!bitmap_empty_p (cfgcleanup_altered_bbs)) | |
647 | { | |
648 | i = bitmap_first_set_bit (cfgcleanup_altered_bbs); | |
649 | bitmap_clear_bit (cfgcleanup_altered_bbs, i); | |
650 | if (i < NUM_FIXED_BLOCKS) | |
651 | continue; | |
652 | ||
653 | bb = BASIC_BLOCK (i); | |
654 | if (!bb) | |
655 | continue; | |
656 | ||
657 | retval |= cleanup_tree_cfg_bb (bb); | |
658 | ||
659 | /* Rerun split_bbs_on_noreturn_calls, in case we have altered any noreturn | |
660 | calls. */ | |
661 | retval |= split_bbs_on_noreturn_calls (); | |
662 | } | |
b8698a0f | 663 | |
672987e8 ZD |
664 | end_recording_case_labels (); |
665 | BITMAP_FREE (cfgcleanup_altered_bbs); | |
89e80dd4 DN |
666 | return retval; |
667 | } | |
668 | ||
669 | ||
e3594cb3 DN |
670 | /* Remove unreachable blocks and other miscellaneous clean up work. |
671 | Return true if the flowgraph was modified, false otherwise. */ | |
89e80dd4 | 672 | |
592c303d ZD |
673 | static bool |
674 | cleanup_tree_cfg_noloop (void) | |
89e80dd4 | 675 | { |
672987e8 | 676 | bool changed; |
89e80dd4 DN |
677 | |
678 | timevar_push (TV_TREE_CLEANUP_CFG); | |
679 | ||
e3594cb3 | 680 | /* Iterate until there are no more cleanups left to do. If any |
672987e8 ZD |
681 | iteration changed the flowgraph, set CHANGED to true. |
682 | ||
683 | If dominance information is available, there cannot be any unreachable | |
684 | blocks. */ | |
2b28c07a | 685 | if (!dom_info_available_p (CDI_DOMINATORS)) |
e3594cb3 | 686 | { |
672987e8 ZD |
687 | changed = delete_unreachable_blocks (); |
688 | calculate_dominance_info (CDI_DOMINATORS); | |
e3594cb3 | 689 | } |
672987e8 | 690 | else |
30251f7a ZD |
691 | { |
692 | #ifdef ENABLE_CHECKING | |
693 | verify_dominators (CDI_DOMINATORS); | |
694 | #endif | |
695 | changed = false; | |
696 | } | |
c9784e6d | 697 | |
672987e8 ZD |
698 | changed |= cleanup_tree_cfg_1 (); |
699 | ||
2b28c07a | 700 | gcc_assert (dom_info_available_p (CDI_DOMINATORS)); |
c9784e6d KH |
701 | compact_blocks (); |
702 | ||
703 | #ifdef ENABLE_CHECKING | |
704 | verify_flow_info (); | |
705 | #endif | |
89e80dd4 | 706 | |
c9784e6d | 707 | timevar_pop (TV_TREE_CLEANUP_CFG); |
89e80dd4 | 708 | |
592c303d | 709 | if (changed && current_loops) |
f87000d0 | 710 | loops_state_set (LOOPS_NEED_FIXUP); |
592c303d | 711 | |
e3594cb3 | 712 | return changed; |
c9784e6d KH |
713 | } |
714 | ||
592c303d | 715 | /* Repairs loop structures. */ |
c9784e6d | 716 | |
592c303d ZD |
717 | static void |
718 | repair_loop_structures (void) | |
c9784e6d | 719 | { |
a222c01a | 720 | bitmap changed_bbs; |
8e89b5b5 | 721 | unsigned n_new_loops; |
a222c01a | 722 | |
cc360b36 SB |
723 | calculate_dominance_info (CDI_DOMINATORS); |
724 | ||
a222c01a MM |
725 | timevar_push (TV_REPAIR_LOOPS); |
726 | changed_bbs = BITMAP_ALLOC (NULL); | |
8e89b5b5 | 727 | n_new_loops = fix_loop_structure (changed_bbs); |
c9784e6d | 728 | |
592c303d ZD |
729 | /* This usually does nothing. But sometimes parts of cfg that originally |
730 | were inside a loop get out of it due to edge removal (since they | |
8e89b5b5 RB |
731 | become unreachable by back edges from latch). Also a former |
732 | irreducible loop can become reducible - in this case force a full | |
733 | rewrite into loop-closed SSA form. */ | |
f87000d0 | 734 | if (loops_state_satisfies_p (LOOP_CLOSED_SSA)) |
8e89b5b5 RB |
735 | rewrite_into_loop_closed_ssa (n_new_loops ? NULL : changed_bbs, |
736 | TODO_update_ssa); | |
c9784e6d | 737 | |
592c303d | 738 | BITMAP_FREE (changed_bbs); |
c9784e6d KH |
739 | |
740 | #ifdef ENABLE_CHECKING | |
592c303d | 741 | verify_loop_structure (); |
c9784e6d | 742 | #endif |
592c303d ZD |
743 | scev_reset (); |
744 | ||
a222c01a | 745 | timevar_pop (TV_REPAIR_LOOPS); |
592c303d ZD |
746 | } |
747 | ||
748 | /* Cleanup cfg and repair loop structures. */ | |
749 | ||
750 | bool | |
751 | cleanup_tree_cfg (void) | |
752 | { | |
753 | bool changed = cleanup_tree_cfg_noloop (); | |
754 | ||
755 | if (current_loops != NULL | |
f87000d0 | 756 | && loops_state_satisfies_p (LOOPS_NEED_FIXUP)) |
592c303d ZD |
757 | repair_loop_structures (); |
758 | ||
1994bfea | 759 | return changed; |
c9784e6d KH |
760 | } |
761 | ||
a9e0d843 RB |
762 | /* Tries to merge the PHI nodes at BB into those at BB's sole successor. |
763 | Returns true if successful. */ | |
c9784e6d | 764 | |
a9e0d843 | 765 | static bool |
c9784e6d KH |
766 | remove_forwarder_block_with_phi (basic_block bb) |
767 | { | |
768 | edge succ = single_succ_edge (bb); | |
769 | basic_block dest = succ->dest; | |
726a989a | 770 | gimple label; |
c9784e6d KH |
771 | basic_block dombb, domdest, dom; |
772 | ||
773 | /* We check for infinite loops already in tree_forwarder_block_p. | |
774 | However it may happen that the infinite loop is created | |
775 | afterwards due to removal of forwarders. */ | |
776 | if (dest == bb) | |
a9e0d843 | 777 | return false; |
c9784e6d KH |
778 | |
779 | /* If the destination block consists of a nonlocal label, do not | |
780 | merge it. */ | |
781 | label = first_stmt (dest); | |
782 | if (label | |
726a989a RB |
783 | && gimple_code (label) == GIMPLE_LABEL |
784 | && DECL_NONLOCAL (gimple_label_label (label))) | |
a9e0d843 | 785 | return false; |
c9784e6d KH |
786 | |
787 | /* Redirect each incoming edge to BB to DEST. */ | |
788 | while (EDGE_COUNT (bb->preds) > 0) | |
789 | { | |
790 | edge e = EDGE_PRED (bb, 0), s; | |
726a989a | 791 | gimple_stmt_iterator gsi; |
c9784e6d KH |
792 | |
793 | s = find_edge (e->src, dest); | |
794 | if (s) | |
795 | { | |
796 | /* We already have an edge S from E->src to DEST. If S and | |
797 | E->dest's sole successor edge have the same PHI arguments | |
798 | at DEST, redirect S to DEST. */ | |
799 | if (phi_alternatives_equal (dest, s, succ)) | |
800 | { | |
801 | e = redirect_edge_and_branch (e, dest); | |
ea7e6d5a | 802 | redirect_edge_var_map_clear (e); |
c9784e6d KH |
803 | continue; |
804 | } | |
805 | ||
806 | /* PHI arguments are different. Create a forwarder block by | |
807 | splitting E so that we can merge PHI arguments on E to | |
808 | DEST. */ | |
809 | e = single_succ_edge (split_edge (e)); | |
810 | } | |
811 | ||
812 | s = redirect_edge_and_branch (e, dest); | |
813 | ||
814 | /* redirect_edge_and_branch must not create a new edge. */ | |
815 | gcc_assert (s == e); | |
816 | ||
817 | /* Add to the PHI nodes at DEST each PHI argument removed at the | |
818 | destination of E. */ | |
726a989a RB |
819 | for (gsi = gsi_start_phis (dest); |
820 | !gsi_end_p (gsi); | |
821 | gsi_next (&gsi)) | |
c9784e6d | 822 | { |
726a989a RB |
823 | gimple phi = gsi_stmt (gsi); |
824 | tree def = gimple_phi_arg_def (phi, succ->dest_idx); | |
f5045c96 | 825 | source_location locus = gimple_phi_arg_location_from_edge (phi, succ); |
c9784e6d KH |
826 | |
827 | if (TREE_CODE (def) == SSA_NAME) | |
828 | { | |
9771b263 | 829 | edge_var_map_vector *head; |
ea7e6d5a AH |
830 | edge_var_map *vm; |
831 | size_t i; | |
c9784e6d KH |
832 | |
833 | /* If DEF is one of the results of PHI nodes removed during | |
834 | redirection, replace it with the PHI argument that used | |
835 | to be on E. */ | |
ea7e6d5a | 836 | head = redirect_edge_var_map_vector (e); |
6fa5e0ed | 837 | FOR_EACH_VEC_SAFE_ELT (head, i, vm) |
c9784e6d | 838 | { |
ea7e6d5a AH |
839 | tree old_arg = redirect_edge_var_map_result (vm); |
840 | tree new_arg = redirect_edge_var_map_def (vm); | |
c9784e6d KH |
841 | |
842 | if (def == old_arg) | |
843 | { | |
844 | def = new_arg; | |
f5045c96 | 845 | locus = redirect_edge_var_map_location (vm); |
c9784e6d KH |
846 | break; |
847 | } | |
848 | } | |
849 | } | |
850 | ||
9e227d60 | 851 | add_phi_arg (phi, def, s, locus); |
c9784e6d KH |
852 | } |
853 | ||
ea7e6d5a | 854 | redirect_edge_var_map_clear (e); |
c9784e6d KH |
855 | } |
856 | ||
857 | /* Update the dominators. */ | |
858 | dombb = get_immediate_dominator (CDI_DOMINATORS, bb); | |
859 | domdest = get_immediate_dominator (CDI_DOMINATORS, dest); | |
860 | if (domdest == bb) | |
861 | { | |
862 | /* Shortcut to avoid calling (relatively expensive) | |
863 | nearest_common_dominator unless necessary. */ | |
864 | dom = dombb; | |
865 | } | |
866 | else | |
867 | dom = nearest_common_dominator (CDI_DOMINATORS, domdest, dombb); | |
868 | ||
869 | set_immediate_dominator (CDI_DOMINATORS, dest, dom); | |
870 | ||
871 | /* Remove BB since all of BB's incoming edges have been redirected | |
872 | to DEST. */ | |
873 | delete_basic_block (bb); | |
a9e0d843 RB |
874 | |
875 | return true; | |
c9784e6d KH |
876 | } |
877 | ||
878 | /* This pass merges PHI nodes if one feeds into another. For example, | |
879 | suppose we have the following: | |
880 | ||
881 | goto <bb 9> (<L9>); | |
882 | ||
883 | <L8>:; | |
884 | tem_17 = foo (); | |
885 | ||
886 | # tem_6 = PHI <tem_17(8), tem_23(7)>; | |
887 | <L9>:; | |
888 | ||
889 | # tem_3 = PHI <tem_6(9), tem_2(5)>; | |
890 | <L10>:; | |
891 | ||
892 | Then we merge the first PHI node into the second one like so: | |
893 | ||
894 | goto <bb 9> (<L10>); | |
895 | ||
896 | <L8>:; | |
897 | tem_17 = foo (); | |
898 | ||
899 | # tem_3 = PHI <tem_23(7), tem_2(5), tem_17(8)>; | |
900 | <L10>:; | |
901 | */ | |
902 | ||
c2924966 | 903 | static unsigned int |
c9784e6d KH |
904 | merge_phi_nodes (void) |
905 | { | |
5ed6ace5 | 906 | basic_block *worklist = XNEWVEC (basic_block, n_basic_blocks); |
c9784e6d KH |
907 | basic_block *current = worklist; |
908 | basic_block bb; | |
909 | ||
910 | calculate_dominance_info (CDI_DOMINATORS); | |
911 | ||
912 | /* Find all PHI nodes that we may be able to merge. */ | |
913 | FOR_EACH_BB (bb) | |
914 | { | |
915 | basic_block dest; | |
916 | ||
917 | /* Look for a forwarder block with PHI nodes. */ | |
918 | if (!tree_forwarder_block_p (bb, true)) | |
919 | continue; | |
920 | ||
921 | dest = single_succ (bb); | |
922 | ||
923 | /* We have to feed into another basic block with PHI | |
924 | nodes. */ | |
8eacd016 | 925 | if (gimple_seq_empty_p (phi_nodes (dest)) |
c9784e6d KH |
926 | /* We don't want to deal with a basic block with |
927 | abnormal edges. */ | |
31ff2426 | 928 | || bb_has_abnormal_pred (bb)) |
c9784e6d KH |
929 | continue; |
930 | ||
931 | if (!dominated_by_p (CDI_DOMINATORS, dest, bb)) | |
932 | { | |
933 | /* If BB does not dominate DEST, then the PHI nodes at | |
934 | DEST must be the only users of the results of the PHI | |
935 | nodes at BB. */ | |
936 | *current++ = bb; | |
937 | } | |
ea65cd37 JL |
938 | else |
939 | { | |
726a989a | 940 | gimple_stmt_iterator gsi; |
338b5886 | 941 | unsigned int dest_idx = single_succ_edge (bb)->dest_idx; |
ea65cd37 JL |
942 | |
943 | /* BB dominates DEST. There may be many users of the PHI | |
944 | nodes in BB. However, there is still a trivial case we | |
945 | can handle. If the result of every PHI in BB is used | |
946 | only by a PHI in DEST, then we can trivially merge the | |
947 | PHI nodes from BB into DEST. */ | |
726a989a RB |
948 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
949 | gsi_next (&gsi)) | |
ea65cd37 | 950 | { |
726a989a RB |
951 | gimple phi = gsi_stmt (gsi); |
952 | tree result = gimple_phi_result (phi); | |
ea65cd37 | 953 | use_operand_p imm_use; |
726a989a | 954 | gimple use_stmt; |
ea65cd37 JL |
955 | |
956 | /* If the PHI's result is never used, then we can just | |
957 | ignore it. */ | |
bfc646bf | 958 | if (has_zero_uses (result)) |
ea65cd37 JL |
959 | continue; |
960 | ||
961 | /* Get the single use of the result of this PHI node. */ | |
962 | if (!single_imm_use (result, &imm_use, &use_stmt) | |
726a989a RB |
963 | || gimple_code (use_stmt) != GIMPLE_PHI |
964 | || gimple_bb (use_stmt) != dest | |
965 | || gimple_phi_arg_def (use_stmt, dest_idx) != result) | |
ea65cd37 JL |
966 | break; |
967 | } | |
968 | ||
c0220ea4 | 969 | /* If the loop above iterated through all the PHI nodes |
ea65cd37 | 970 | in BB, then we can merge the PHIs from BB into DEST. */ |
726a989a | 971 | if (gsi_end_p (gsi)) |
ea65cd37 JL |
972 | *current++ = bb; |
973 | } | |
c9784e6d KH |
974 | } |
975 | ||
976 | /* Now let's drain WORKLIST. */ | |
a9e0d843 | 977 | bool changed = false; |
c9784e6d KH |
978 | while (current != worklist) |
979 | { | |
980 | bb = *--current; | |
a9e0d843 | 981 | changed |= remove_forwarder_block_with_phi (bb); |
c9784e6d | 982 | } |
c9784e6d | 983 | free (worklist); |
a9e0d843 RB |
984 | |
985 | /* Removing forwarder blocks can cause formerly irreducible loops | |
986 | to become reducible if we merged two entry blocks. */ | |
987 | if (changed | |
988 | && current_loops) | |
989 | loops_state_set (LOOPS_NEED_FIXUP); | |
990 | ||
c2924966 | 991 | return 0; |
c9784e6d KH |
992 | } |
993 | ||
994 | static bool | |
995 | gate_merge_phi (void) | |
996 | { | |
997 | return 1; | |
998 | } | |
999 | ||
27a4cd48 DM |
1000 | namespace { |
1001 | ||
1002 | const pass_data pass_data_merge_phi = | |
8ddbbcae | 1003 | { |
27a4cd48 DM |
1004 | GIMPLE_PASS, /* type */ |
1005 | "mergephi", /* name */ | |
1006 | OPTGROUP_NONE, /* optinfo_flags */ | |
1007 | true, /* has_gate */ | |
1008 | true, /* has_execute */ | |
1009 | TV_TREE_MERGE_PHI, /* tv_id */ | |
1010 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1011 | 0, /* properties_provided */ | |
1012 | 0, /* properties_destroyed */ | |
1013 | 0, /* todo_flags_start */ | |
1014 | TODO_verify_ssa, /* todo_flags_finish */ | |
c9784e6d | 1015 | }; |
27a4cd48 DM |
1016 | |
1017 | class pass_merge_phi : public gimple_opt_pass | |
1018 | { | |
1019 | public: | |
c3284718 RS |
1020 | pass_merge_phi (gcc::context *ctxt) |
1021 | : gimple_opt_pass (pass_data_merge_phi, ctxt) | |
27a4cd48 DM |
1022 | {} |
1023 | ||
1024 | /* opt_pass methods: */ | |
65d3284b | 1025 | opt_pass * clone () { return new pass_merge_phi (m_ctxt); } |
27a4cd48 DM |
1026 | bool gate () { return gate_merge_phi (); } |
1027 | unsigned int execute () { return merge_phi_nodes (); } | |
1028 | ||
1029 | }; // class pass_merge_phi | |
1030 | ||
1031 | } // anon namespace | |
1032 | ||
1033 | gimple_opt_pass * | |
1034 | make_pass_merge_phi (gcc::context *ctxt) | |
1035 | { | |
1036 | return new pass_merge_phi (ctxt); | |
1037 | } | |
4484a35a AM |
1038 | |
1039 | /* Pass: cleanup the CFG just before expanding trees to RTL. | |
1040 | This is just a round of label cleanups and case node grouping | |
1041 | because after the tree optimizers have run such cleanups may | |
1042 | be necessary. */ | |
1043 | ||
1044 | static unsigned int | |
1045 | execute_cleanup_cfg_post_optimizing (void) | |
1046 | { | |
1047 | unsigned int todo = 0; | |
1048 | if (cleanup_tree_cfg ()) | |
1049 | todo |= TODO_update_ssa; | |
1050 | maybe_remove_unreachable_handlers (); | |
1051 | cleanup_dead_labels (); | |
1052 | group_case_labels (); | |
1053 | if ((flag_compare_debug_opt || flag_compare_debug) | |
1054 | && flag_dump_final_insns) | |
1055 | { | |
1056 | FILE *final_output = fopen (flag_dump_final_insns, "a"); | |
1057 | ||
1058 | if (!final_output) | |
1059 | { | |
1060 | error ("could not open final insn dump file %qs: %m", | |
1061 | flag_dump_final_insns); | |
1062 | flag_dump_final_insns = NULL; | |
1063 | } | |
1064 | else | |
1065 | { | |
1066 | int save_unnumbered = flag_dump_unnumbered; | |
1067 | int save_noaddr = flag_dump_noaddr; | |
1068 | ||
1069 | flag_dump_noaddr = flag_dump_unnumbered = 1; | |
1070 | fprintf (final_output, "\n"); | |
1071 | dump_enumerated_decls (final_output, dump_flags | TDF_NOUID); | |
1072 | flag_dump_noaddr = save_noaddr; | |
1073 | flag_dump_unnumbered = save_unnumbered; | |
1074 | if (fclose (final_output)) | |
1075 | { | |
1076 | error ("could not close final insn dump file %qs: %m", | |
1077 | flag_dump_final_insns); | |
1078 | flag_dump_final_insns = NULL; | |
1079 | } | |
1080 | } | |
1081 | } | |
1082 | return todo; | |
1083 | } | |
1084 | ||
1085 | namespace { | |
1086 | ||
1087 | const pass_data pass_data_cleanup_cfg_post_optimizing = | |
1088 | { | |
1089 | GIMPLE_PASS, /* type */ | |
1090 | "optimized", /* name */ | |
1091 | OPTGROUP_NONE, /* optinfo_flags */ | |
1092 | false, /* has_gate */ | |
1093 | true, /* has_execute */ | |
1094 | TV_TREE_CLEANUP_CFG, /* tv_id */ | |
1095 | PROP_cfg, /* properties_required */ | |
1096 | 0, /* properties_provided */ | |
1097 | 0, /* properties_destroyed */ | |
1098 | 0, /* todo_flags_start */ | |
1099 | TODO_remove_unused_locals, /* todo_flags_finish */ | |
1100 | }; | |
1101 | ||
1102 | class pass_cleanup_cfg_post_optimizing : public gimple_opt_pass | |
1103 | { | |
1104 | public: | |
1105 | pass_cleanup_cfg_post_optimizing (gcc::context *ctxt) | |
1106 | : gimple_opt_pass (pass_data_cleanup_cfg_post_optimizing, ctxt) | |
1107 | {} | |
1108 | ||
1109 | /* opt_pass methods: */ | |
1110 | unsigned int execute () { | |
1111 | return execute_cleanup_cfg_post_optimizing (); | |
1112 | } | |
1113 | ||
1114 | }; // class pass_cleanup_cfg_post_optimizing | |
1115 | ||
1116 | } // anon namespace | |
1117 | ||
1118 | gimple_opt_pass * | |
1119 | make_pass_cleanup_cfg_post_optimizing (gcc::context *ctxt) | |
1120 | { | |
1121 | return new pass_cleanup_cfg_post_optimizing (ctxt); | |
1122 | } | |
1123 | ||
1124 |