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c9784e6d | 1 | /* CFG cleanup for trees. |
23a5b65a | 2 | Copyright (C) 2001-2014 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 | 30 | #include "langhooks.h" |
2fb9a547 AM |
31 | #include "tree-ssa-alias.h" |
32 | #include "internal-fn.h" | |
33 | #include "tree-eh.h" | |
34 | #include "gimple-expr.h" | |
35 | #include "is-a.h" | |
18f429e2 | 36 | #include "gimple.h" |
45b0be94 | 37 | #include "gimplify.h" |
5be5c238 | 38 | #include "gimple-iterator.h" |
442b4905 AM |
39 | #include "gimple-ssa.h" |
40 | #include "tree-cfg.h" | |
41 | #include "tree-phinodes.h" | |
42 | #include "ssa-iterators.h" | |
d8a2d370 | 43 | #include "stringpool.h" |
442b4905 | 44 | #include "tree-ssanames.h" |
e28030cf | 45 | #include "tree-ssa-loop-manip.h" |
d8a2d370 | 46 | #include "expr.h" |
442b4905 | 47 | #include "tree-dfa.h" |
7a300452 | 48 | #include "tree-ssa.h" |
c9784e6d | 49 | #include "tree-pass.h" |
c9784e6d KH |
50 | #include "except.h" |
51 | #include "cfgloop.h" | |
c9784e6d KH |
52 | #include "hashtab.h" |
53 | #include "tree-ssa-propagate.h" | |
17684618 | 54 | #include "tree-scalar-evolution.h" |
c9784e6d | 55 | |
672987e8 ZD |
56 | /* The set of blocks in that at least one of the following changes happened: |
57 | -- the statement at the end of the block was changed | |
58 | -- the block was newly created | |
59 | -- the set of the predecessors of the block changed | |
60 | -- the set of the successors of the block changed | |
61 | ??? Maybe we could track these changes separately, since they determine | |
62 | what cleanups it makes sense to try on the block. */ | |
63 | bitmap cfgcleanup_altered_bbs; | |
64 | ||
c9784e6d KH |
65 | /* Remove any fallthru edge from EV. Return true if an edge was removed. */ |
66 | ||
67 | static bool | |
9771b263 | 68 | remove_fallthru_edge (vec<edge, va_gc> *ev) |
c9784e6d KH |
69 | { |
70 | edge_iterator ei; | |
71 | edge e; | |
72 | ||
73 | FOR_EACH_EDGE (e, ei, ev) | |
74 | if ((e->flags & EDGE_FALLTHRU) != 0) | |
75 | { | |
0107dca2 RB |
76 | if (e->flags & EDGE_COMPLEX) |
77 | e->flags &= ~EDGE_FALLTHRU; | |
78 | else | |
79 | remove_edge_and_dominated_blocks (e); | |
c9784e6d KH |
80 | return true; |
81 | } | |
82 | return false; | |
83 | } | |
84 | ||
726a989a | 85 | |
c9784e6d KH |
86 | /* Disconnect an unreachable block in the control expression starting |
87 | at block BB. */ | |
88 | ||
89 | static bool | |
726a989a | 90 | cleanup_control_expr_graph (basic_block bb, gimple_stmt_iterator gsi) |
c9784e6d KH |
91 | { |
92 | edge taken_edge; | |
93 | bool retval = false; | |
726a989a RB |
94 | gimple stmt = gsi_stmt (gsi); |
95 | tree val; | |
c9784e6d KH |
96 | |
97 | if (!single_succ_p (bb)) | |
98 | { | |
99 | edge e; | |
100 | edge_iterator ei; | |
6ac01510 | 101 | bool warned; |
37530014 | 102 | location_t loc; |
6ac01510 ILT |
103 | |
104 | fold_defer_overflow_warnings (); | |
37530014 RG |
105 | loc = gimple_location (stmt); |
106 | switch (gimple_code (stmt)) | |
107 | { | |
108 | case GIMPLE_COND: | |
fea4ea73 EB |
109 | val = fold_binary_loc (loc, gimple_cond_code (stmt), |
110 | boolean_type_node, | |
111 | gimple_cond_lhs (stmt), | |
112 | gimple_cond_rhs (stmt)); | |
113 | break; | |
37530014 RG |
114 | |
115 | case GIMPLE_SWITCH: | |
116 | val = gimple_switch_index (stmt); | |
117 | break; | |
118 | ||
119 | default: | |
120 | val = NULL_TREE; | |
121 | } | |
c9784e6d KH |
122 | taken_edge = find_taken_edge (bb, val); |
123 | if (!taken_edge) | |
6ac01510 ILT |
124 | { |
125 | fold_undefer_and_ignore_overflow_warnings (); | |
126 | return false; | |
127 | } | |
c9784e6d KH |
128 | |
129 | /* Remove all the edges except the one that is always executed. */ | |
6ac01510 | 130 | warned = false; |
c9784e6d KH |
131 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
132 | { | |
133 | if (e != taken_edge) | |
134 | { | |
6ac01510 ILT |
135 | if (!warned) |
136 | { | |
137 | fold_undefer_overflow_warnings | |
726a989a | 138 | (true, stmt, WARN_STRICT_OVERFLOW_CONDITIONAL); |
6ac01510 ILT |
139 | warned = true; |
140 | } | |
141 | ||
c9784e6d KH |
142 | taken_edge->probability += e->probability; |
143 | taken_edge->count += e->count; | |
672987e8 | 144 | remove_edge_and_dominated_blocks (e); |
c9784e6d KH |
145 | retval = true; |
146 | } | |
147 | else | |
148 | ei_next (&ei); | |
149 | } | |
6ac01510 ILT |
150 | if (!warned) |
151 | fold_undefer_and_ignore_overflow_warnings (); | |
c9784e6d KH |
152 | if (taken_edge->probability > REG_BR_PROB_BASE) |
153 | taken_edge->probability = REG_BR_PROB_BASE; | |
154 | } | |
155 | else | |
156 | taken_edge = single_succ_edge (bb); | |
157 | ||
672987e8 | 158 | bitmap_set_bit (cfgcleanup_altered_bbs, bb->index); |
726a989a | 159 | gsi_remove (&gsi, true); |
c9784e6d KH |
160 | taken_edge->flags = EDGE_FALLTHRU; |
161 | ||
c9784e6d KH |
162 | return retval; |
163 | } | |
164 | ||
672987e8 ZD |
165 | /* Try to remove superfluous control structures in basic block BB. Returns |
166 | true if anything changes. */ | |
c9784e6d KH |
167 | |
168 | static bool | |
672987e8 | 169 | cleanup_control_flow_bb (basic_block bb) |
c9784e6d | 170 | { |
726a989a | 171 | gimple_stmt_iterator gsi; |
c9784e6d | 172 | bool retval = false; |
726a989a | 173 | gimple stmt; |
c9784e6d | 174 | |
672987e8 ZD |
175 | /* If the last statement of the block could throw and now cannot, |
176 | we need to prune cfg. */ | |
726a989a | 177 | retval |= gimple_purge_dead_eh_edges (bb); |
672987e8 | 178 | |
726a989a RB |
179 | gsi = gsi_last_bb (bb); |
180 | if (gsi_end_p (gsi)) | |
672987e8 ZD |
181 | return retval; |
182 | ||
726a989a | 183 | stmt = gsi_stmt (gsi); |
672987e8 | 184 | |
726a989a RB |
185 | if (gimple_code (stmt) == GIMPLE_COND |
186 | || gimple_code (stmt) == GIMPLE_SWITCH) | |
187 | retval |= cleanup_control_expr_graph (bb, gsi); | |
188 | else if (gimple_code (stmt) == GIMPLE_GOTO | |
189 | && TREE_CODE (gimple_goto_dest (stmt)) == ADDR_EXPR | |
190 | && (TREE_CODE (TREE_OPERAND (gimple_goto_dest (stmt), 0)) | |
672987e8 | 191 | == LABEL_DECL)) |
c9784e6d | 192 | { |
726a989a RB |
193 | /* If we had a computed goto which has a compile-time determinable |
194 | destination, then we can eliminate the goto. */ | |
672987e8 ZD |
195 | edge e; |
196 | tree label; | |
197 | edge_iterator ei; | |
198 | basic_block target_block; | |
c9784e6d | 199 | |
672987e8 ZD |
200 | /* First look at all the outgoing edges. Delete any outgoing |
201 | edges which do not go to the right block. For the one | |
202 | edge which goes to the right block, fix up its flags. */ | |
726a989a | 203 | label = TREE_OPERAND (gimple_goto_dest (stmt), 0); |
672987e8 ZD |
204 | target_block = label_to_block (label); |
205 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) | |
c9784e6d | 206 | { |
672987e8 ZD |
207 | if (e->dest != target_block) |
208 | remove_edge_and_dominated_blocks (e); | |
209 | else | |
c9784e6d | 210 | { |
672987e8 ZD |
211 | /* Turn off the EDGE_ABNORMAL flag. */ |
212 | e->flags &= ~EDGE_ABNORMAL; | |
c9784e6d | 213 | |
672987e8 ZD |
214 | /* And set EDGE_FALLTHRU. */ |
215 | e->flags |= EDGE_FALLTHRU; | |
216 | ei_next (&ei); | |
217 | } | |
c9784e6d KH |
218 | } |
219 | ||
672987e8 ZD |
220 | bitmap_set_bit (cfgcleanup_altered_bbs, bb->index); |
221 | bitmap_set_bit (cfgcleanup_altered_bbs, target_block->index); | |
222 | ||
223 | /* Remove the GOTO_EXPR as it is not needed. The CFG has all the | |
224 | relevant information we need. */ | |
726a989a | 225 | gsi_remove (&gsi, true); |
672987e8 | 226 | retval = true; |
c9784e6d | 227 | } |
672987e8 ZD |
228 | |
229 | /* Check for indirect calls that have been turned into | |
230 | noreturn calls. */ | |
726a989a RB |
231 | else if (is_gimple_call (stmt) |
232 | && gimple_call_noreturn_p (stmt) | |
233 | && remove_fallthru_edge (bb->succs)) | |
672987e8 ZD |
234 | retval = true; |
235 | ||
c9784e6d KH |
236 | return retval; |
237 | } | |
238 | ||
239 | /* Return true if basic block BB does nothing except pass control | |
240 | flow to another block and that we can safely insert a label at | |
241 | the start of the successor block. | |
242 | ||
243 | As a precondition, we require that BB be not equal to | |
6626665f | 244 | the entry block. */ |
c9784e6d KH |
245 | |
246 | static bool | |
247 | tree_forwarder_block_p (basic_block bb, bool phi_wanted) | |
248 | { | |
726a989a | 249 | gimple_stmt_iterator gsi; |
f99fcb3b | 250 | location_t locus; |
c9784e6d KH |
251 | |
252 | /* BB must have a single outgoing edge. */ | |
253 | if (single_succ_p (bb) != 1 | |
254 | /* If PHI_WANTED is false, BB must not have any PHI nodes. | |
255 | Otherwise, BB must have PHI nodes. */ | |
726a989a | 256 | || gimple_seq_empty_p (phi_nodes (bb)) == phi_wanted |
6626665f | 257 | /* BB may not be a predecessor of the exit block. */ |
fefa31b5 | 258 | || single_succ (bb) == EXIT_BLOCK_PTR_FOR_FN (cfun) |
c9784e6d KH |
259 | /* Nor should this be an infinite loop. */ |
260 | || single_succ (bb) == bb | |
261 | /* BB may not have an abnormal outgoing edge. */ | |
262 | || (single_succ_edge (bb)->flags & EDGE_ABNORMAL)) | |
263 | return false; | |
264 | ||
fefa31b5 | 265 | gcc_checking_assert (bb != ENTRY_BLOCK_PTR_FOR_FN (cfun)); |
c9784e6d | 266 | |
f99fcb3b JJ |
267 | locus = single_succ_edge (bb)->goto_locus; |
268 | ||
1d65f45c RH |
269 | /* There should not be an edge coming from entry, or an EH edge. */ |
270 | { | |
271 | edge_iterator ei; | |
272 | edge e; | |
273 | ||
274 | FOR_EACH_EDGE (e, ei, bb->preds) | |
fefa31b5 | 275 | if (e->src == ENTRY_BLOCK_PTR_FOR_FN (cfun) || (e->flags & EDGE_EH)) |
1d65f45c | 276 | return false; |
f99fcb3b JJ |
277 | /* If goto_locus of any of the edges differs, prevent removing |
278 | the forwarder block for -O0. */ | |
279 | else if (optimize == 0 && e->goto_locus != locus) | |
280 | return false; | |
1d65f45c RH |
281 | } |
282 | ||
c9784e6d KH |
283 | /* Now walk through the statements backward. We can ignore labels, |
284 | anything else means this is not a forwarder block. */ | |
726a989a | 285 | for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi)) |
c9784e6d | 286 | { |
726a989a | 287 | gimple stmt = gsi_stmt (gsi); |
c9784e6d | 288 | |
726a989a | 289 | switch (gimple_code (stmt)) |
c9784e6d | 290 | { |
726a989a RB |
291 | case GIMPLE_LABEL: |
292 | if (DECL_NONLOCAL (gimple_label_label (stmt))) | |
c9784e6d | 293 | return false; |
f99fcb3b JJ |
294 | if (optimize == 0 && gimple_location (stmt) != locus) |
295 | return false; | |
c9784e6d KH |
296 | break; |
297 | ||
b5b8b0ac AO |
298 | /* ??? For now, hope there's a corresponding debug |
299 | assignment at the destination. */ | |
300 | case GIMPLE_DEBUG: | |
301 | break; | |
302 | ||
c9784e6d KH |
303 | default: |
304 | return false; | |
305 | } | |
306 | } | |
307 | ||
c9784e6d KH |
308 | if (current_loops) |
309 | { | |
310 | basic_block dest; | |
311 | /* Protect loop latches, headers and preheaders. */ | |
312 | if (bb->loop_father->header == bb) | |
313 | return false; | |
314 | dest = EDGE_SUCC (bb, 0)->dest; | |
315 | ||
316 | if (dest->loop_father->header == dest) | |
317 | return false; | |
318 | } | |
c9784e6d KH |
319 | return true; |
320 | } | |
321 | ||
c9784e6d KH |
322 | /* If all the PHI nodes in DEST have alternatives for E1 and E2 and |
323 | those alternatives are equal in each of the PHI nodes, then return | |
324 | true, else return false. */ | |
325 | ||
326 | static bool | |
327 | phi_alternatives_equal (basic_block dest, edge e1, edge e2) | |
328 | { | |
329 | int n1 = e1->dest_idx; | |
330 | int n2 = e2->dest_idx; | |
726a989a | 331 | gimple_stmt_iterator gsi; |
c9784e6d | 332 | |
726a989a | 333 | for (gsi = gsi_start_phis (dest); !gsi_end_p (gsi); gsi_next (&gsi)) |
c9784e6d | 334 | { |
726a989a RB |
335 | gimple phi = gsi_stmt (gsi); |
336 | tree val1 = gimple_phi_arg_def (phi, n1); | |
337 | tree val2 = gimple_phi_arg_def (phi, n2); | |
c9784e6d KH |
338 | |
339 | gcc_assert (val1 != NULL_TREE); | |
340 | gcc_assert (val2 != NULL_TREE); | |
341 | ||
342 | if (!operand_equal_for_phi_arg_p (val1, val2)) | |
343 | return false; | |
344 | } | |
345 | ||
346 | return true; | |
347 | } | |
348 | ||
672987e8 | 349 | /* Removes forwarder block BB. Returns false if this failed. */ |
c9784e6d KH |
350 | |
351 | static bool | |
672987e8 | 352 | remove_forwarder_block (basic_block bb) |
c9784e6d KH |
353 | { |
354 | edge succ = single_succ_edge (bb), e, s; | |
355 | basic_block dest = succ->dest; | |
726a989a | 356 | gimple label; |
c9784e6d | 357 | edge_iterator ei; |
726a989a | 358 | gimple_stmt_iterator gsi, gsi_to; |
70235ab9 | 359 | bool can_move_debug_stmts; |
c9784e6d KH |
360 | |
361 | /* We check for infinite loops already in tree_forwarder_block_p. | |
362 | However it may happen that the infinite loop is created | |
363 | afterwards due to removal of forwarders. */ | |
364 | if (dest == bb) | |
365 | return false; | |
366 | ||
28e5ca15 RB |
367 | /* If the destination block consists of a nonlocal label or is a |
368 | EH landing pad, do not merge it. */ | |
c9784e6d KH |
369 | label = first_stmt (dest); |
370 | if (label | |
726a989a | 371 | && gimple_code (label) == GIMPLE_LABEL |
28e5ca15 RB |
372 | && (DECL_NONLOCAL (gimple_label_label (label)) |
373 | || EH_LANDING_PAD_NR (gimple_label_label (label)) != 0)) | |
c9784e6d KH |
374 | return false; |
375 | ||
376 | /* If there is an abnormal edge to basic block BB, but not into | |
377 | dest, problems might occur during removal of the phi node at out | |
378 | of ssa due to overlapping live ranges of registers. | |
379 | ||
380 | If there is an abnormal edge in DEST, the problems would occur | |
381 | anyway since cleanup_dead_labels would then merge the labels for | |
382 | two different eh regions, and rest of exception handling code | |
383 | does not like it. | |
384 | ||
385 | So if there is an abnormal edge to BB, proceed only if there is | |
386 | no abnormal edge to DEST and there are no phi nodes in DEST. */ | |
31ff2426 NF |
387 | if (bb_has_abnormal_pred (bb) |
388 | && (bb_has_abnormal_pred (dest) | |
1197e789 RG |
389 | || !gimple_seq_empty_p (phi_nodes (dest)))) |
390 | return false; | |
c9784e6d KH |
391 | |
392 | /* If there are phi nodes in DEST, and some of the blocks that are | |
393 | predecessors of BB are also predecessors of DEST, check that the | |
394 | phi node arguments match. */ | |
726a989a | 395 | if (!gimple_seq_empty_p (phi_nodes (dest))) |
c9784e6d KH |
396 | { |
397 | FOR_EACH_EDGE (e, ei, bb->preds) | |
398 | { | |
399 | s = find_edge (e->src, dest); | |
400 | if (!s) | |
401 | continue; | |
402 | ||
403 | if (!phi_alternatives_equal (dest, succ, s)) | |
404 | return false; | |
405 | } | |
406 | } | |
407 | ||
dc764d10 | 408 | can_move_debug_stmts = MAY_HAVE_DEBUG_STMTS && single_pred_p (dest); |
70235ab9 | 409 | |
c9784e6d KH |
410 | /* Redirect the edges. */ |
411 | for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); ) | |
412 | { | |
672987e8 ZD |
413 | bitmap_set_bit (cfgcleanup_altered_bbs, e->src->index); |
414 | ||
c9784e6d KH |
415 | if (e->flags & EDGE_ABNORMAL) |
416 | { | |
417 | /* If there is an abnormal edge, redirect it anyway, and | |
418 | move the labels to the new block to make it legal. */ | |
419 | s = redirect_edge_succ_nodup (e, dest); | |
420 | } | |
421 | else | |
422 | s = redirect_edge_and_branch (e, dest); | |
423 | ||
424 | if (s == e) | |
425 | { | |
426 | /* Create arguments for the phi nodes, since the edge was not | |
427 | here before. */ | |
726a989a RB |
428 | for (gsi = gsi_start_phis (dest); |
429 | !gsi_end_p (gsi); | |
430 | gsi_next (&gsi)) | |
431 | { | |
432 | gimple phi = gsi_stmt (gsi); | |
f5045c96 | 433 | source_location l = gimple_phi_arg_location_from_edge (phi, succ); |
2724573f RB |
434 | tree def = gimple_phi_arg_def (phi, succ->dest_idx); |
435 | add_phi_arg (phi, unshare_expr (def), s, l); | |
726a989a | 436 | } |
c9784e6d | 437 | } |
c9784e6d KH |
438 | } |
439 | ||
1197e789 RG |
440 | /* Move nonlocal labels and computed goto targets as well as user |
441 | defined labels and labels with an EH landing pad number to the | |
442 | new block, so that the redirection of the abnormal edges works, | |
443 | jump targets end up in a sane place and debug information for | |
444 | labels is retained. */ | |
445 | gsi_to = gsi_start_bb (dest); | |
446 | for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) | |
447 | { | |
448 | tree decl; | |
449 | label = gsi_stmt (gsi); | |
450 | if (is_gimple_debug (label)) | |
451 | break; | |
452 | decl = gimple_label_label (label); | |
453 | if (EH_LANDING_PAD_NR (decl) != 0 | |
454 | || DECL_NONLOCAL (decl) | |
455 | || FORCED_LABEL (decl) | |
456 | || !DECL_ARTIFICIAL (decl)) | |
457 | { | |
458 | gsi_remove (&gsi, false); | |
459 | gsi_insert_before (&gsi_to, label, GSI_SAME_STMT); | |
460 | } | |
461 | else | |
462 | gsi_next (&gsi); | |
463 | } | |
464 | ||
dc764d10 | 465 | /* Move debug statements if the destination has a single predecessor. */ |
70235ab9 | 466 | if (can_move_debug_stmts) |
c9784e6d | 467 | { |
1197e789 RG |
468 | gsi_to = gsi_after_labels (dest); |
469 | for (gsi = gsi_after_labels (bb); !gsi_end_p (gsi); ) | |
c9784e6d | 470 | { |
70235ab9 JJ |
471 | gimple debug = gsi_stmt (gsi); |
472 | if (!is_gimple_debug (debug)) | |
1197e789 | 473 | break; |
726a989a | 474 | gsi_remove (&gsi, false); |
70235ab9 | 475 | gsi_insert_before (&gsi_to, debug, GSI_SAME_STMT); |
c9784e6d KH |
476 | } |
477 | } | |
478 | ||
672987e8 ZD |
479 | bitmap_set_bit (cfgcleanup_altered_bbs, dest->index); |
480 | ||
c9784e6d KH |
481 | /* Update the dominators. */ |
482 | if (dom_info_available_p (CDI_DOMINATORS)) | |
483 | { | |
484 | basic_block dom, dombb, domdest; | |
485 | ||
486 | dombb = get_immediate_dominator (CDI_DOMINATORS, bb); | |
487 | domdest = get_immediate_dominator (CDI_DOMINATORS, dest); | |
488 | if (domdest == bb) | |
489 | { | |
490 | /* Shortcut to avoid calling (relatively expensive) | |
491 | nearest_common_dominator unless necessary. */ | |
492 | dom = dombb; | |
493 | } | |
494 | else | |
495 | dom = nearest_common_dominator (CDI_DOMINATORS, domdest, dombb); | |
496 | ||
497 | set_immediate_dominator (CDI_DOMINATORS, dest, dom); | |
498 | } | |
499 | ||
500 | /* And kill the forwarder block. */ | |
501 | delete_basic_block (bb); | |
502 | ||
503 | return true; | |
504 | } | |
505 | ||
566d09ef JH |
506 | /* STMT is a call that has been discovered noreturn. Fixup the CFG |
507 | and remove LHS. Return true if something changed. */ | |
508 | ||
509 | bool | |
510 | fixup_noreturn_call (gimple stmt) | |
511 | { | |
512 | basic_block bb = gimple_bb (stmt); | |
513 | bool changed = false; | |
514 | ||
515 | if (gimple_call_builtin_p (stmt, BUILT_IN_RETURN)) | |
516 | return false; | |
517 | ||
518 | /* First split basic block if stmt is not last. */ | |
519 | if (stmt != gsi_stmt (gsi_last_bb (bb))) | |
520 | split_block (bb, stmt); | |
521 | ||
522 | changed |= remove_fallthru_edge (bb->succs); | |
523 | ||
524 | /* If there is LHS, remove it. */ | |
525 | if (gimple_call_lhs (stmt)) | |
526 | { | |
527 | tree op = gimple_call_lhs (stmt); | |
528 | gimple_call_set_lhs (stmt, NULL_TREE); | |
02d635a2 | 529 | |
acb6411a | 530 | /* We need to remove SSA name to avoid checking errors. |
566d09ef | 531 | All uses are dominated by the noreturn and thus will |
02d635a2 JH |
532 | be removed afterwards. |
533 | We proactively remove affected non-PHI statements to avoid | |
534 | fixup_cfg from trying to update them and crashing. */ | |
566d09ef JH |
535 | if (TREE_CODE (op) == SSA_NAME) |
536 | { | |
537 | use_operand_p use_p; | |
538 | imm_use_iterator iter; | |
539 | gimple use_stmt; | |
02d635a2 JH |
540 | bitmap_iterator bi; |
541 | unsigned int bb_index; | |
542 | ||
543 | bitmap blocks = BITMAP_ALLOC (NULL); | |
566d09ef JH |
544 | |
545 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, op) | |
02d635a2 JH |
546 | { |
547 | if (gimple_code (use_stmt) != GIMPLE_PHI) | |
548 | bitmap_set_bit (blocks, gimple_bb (use_stmt)->index); | |
549 | else | |
550 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
551 | SET_USE (use_p, error_mark_node); | |
552 | } | |
553 | EXECUTE_IF_SET_IN_BITMAP (blocks, 0, bb_index, bi) | |
06e28de2 | 554 | delete_basic_block (BASIC_BLOCK_FOR_FN (cfun, bb_index)); |
02d635a2 JH |
555 | BITMAP_FREE (blocks); |
556 | release_ssa_name (op); | |
566d09ef JH |
557 | } |
558 | update_stmt (stmt); | |
559 | changed = true; | |
560 | } | |
8ba0479e JJ |
561 | /* Similarly remove VDEF if there is any. */ |
562 | else if (gimple_vdef (stmt)) | |
563 | update_stmt (stmt); | |
566d09ef JH |
564 | return changed; |
565 | } | |
566 | ||
567 | ||
672987e8 ZD |
568 | /* Split basic blocks on calls in the middle of a basic block that are now |
569 | known not to return, and remove the unreachable code. */ | |
c9784e6d KH |
570 | |
571 | static bool | |
672987e8 | 572 | split_bbs_on_noreturn_calls (void) |
c9784e6d | 573 | { |
c9784e6d | 574 | bool changed = false; |
726a989a | 575 | gimple stmt; |
672987e8 | 576 | basic_block bb; |
c9784e6d | 577 | |
672987e8 ZD |
578 | /* Detect cases where a mid-block call is now known not to return. */ |
579 | if (cfun->gimple_df) | |
9771b263 | 580 | while (vec_safe_length (MODIFIED_NORETURN_CALLS (cfun))) |
672987e8 | 581 | { |
9771b263 | 582 | stmt = MODIFIED_NORETURN_CALLS (cfun)->pop (); |
726a989a | 583 | bb = gimple_bb (stmt); |
4d731f17 JJ |
584 | /* BB might be deleted at this point, so verify first |
585 | BB is present in the cfg. */ | |
672987e8 | 586 | if (bb == NULL |
4d731f17 | 587 | || bb->index < NUM_FIXED_BLOCKS |
8b1c6fd7 | 588 | || bb->index >= last_basic_block_for_fn (cfun) |
06e28de2 | 589 | || BASIC_BLOCK_FOR_FN (cfun, bb->index) != bb |
726a989a | 590 | || !gimple_call_noreturn_p (stmt)) |
672987e8 ZD |
591 | continue; |
592 | ||
566d09ef | 593 | changed |= fixup_noreturn_call (stmt); |
672987e8 | 594 | } |
c9784e6d | 595 | |
c9784e6d KH |
596 | return changed; |
597 | } | |
598 | ||
672987e8 ZD |
599 | /* Tries to cleanup cfg in basic block BB. Returns true if anything |
600 | changes. */ | |
c9784e6d | 601 | |
89e80dd4 | 602 | static bool |
672987e8 | 603 | cleanup_tree_cfg_bb (basic_block bb) |
c9784e6d | 604 | { |
65e7bfe3 | 605 | bool retval = cleanup_control_flow_bb (bb); |
b8698a0f | 606 | |
f99fcb3b | 607 | if (tree_forwarder_block_p (bb, false) |
672987e8 ZD |
608 | && remove_forwarder_block (bb)) |
609 | return true; | |
c9784e6d | 610 | |
89e80dd4 DN |
611 | /* Merging the blocks may create new opportunities for folding |
612 | conditional branches (due to the elimination of single-valued PHI | |
613 | nodes). */ | |
672987e8 ZD |
614 | if (single_succ_p (bb) |
615 | && can_merge_blocks_p (bb, single_succ (bb))) | |
616 | { | |
617 | merge_blocks (bb, single_succ (bb)); | |
618 | return true; | |
619 | } | |
620 | ||
621 | return retval; | |
622 | } | |
623 | ||
624 | /* Iterate the cfg cleanups, while anything changes. */ | |
625 | ||
626 | static bool | |
627 | cleanup_tree_cfg_1 (void) | |
628 | { | |
629 | bool retval = false; | |
630 | basic_block bb; | |
631 | unsigned i, n; | |
632 | ||
633 | retval |= split_bbs_on_noreturn_calls (); | |
634 | ||
635 | /* Prepare the worklists of altered blocks. */ | |
636 | cfgcleanup_altered_bbs = BITMAP_ALLOC (NULL); | |
637 | ||
638 | /* During forwarder block cleanup, we may redirect edges out of | |
639 | SWITCH_EXPRs, which can get expensive. So we want to enable | |
640 | recording of edge to CASE_LABEL_EXPR. */ | |
641 | start_recording_case_labels (); | |
89e80dd4 | 642 | |
11cd3bed | 643 | /* Start by iterating over all basic blocks. We cannot use FOR_EACH_BB_FN, |
672987e8 | 644 | since the basic blocks may get removed. */ |
8b1c6fd7 | 645 | n = last_basic_block_for_fn (cfun); |
672987e8 ZD |
646 | for (i = NUM_FIXED_BLOCKS; i < n; i++) |
647 | { | |
06e28de2 | 648 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
672987e8 ZD |
649 | if (bb) |
650 | retval |= cleanup_tree_cfg_bb (bb); | |
651 | } | |
652 | ||
653 | /* Now process the altered blocks, as long as any are available. */ | |
654 | while (!bitmap_empty_p (cfgcleanup_altered_bbs)) | |
655 | { | |
656 | i = bitmap_first_set_bit (cfgcleanup_altered_bbs); | |
657 | bitmap_clear_bit (cfgcleanup_altered_bbs, i); | |
658 | if (i < NUM_FIXED_BLOCKS) | |
659 | continue; | |
660 | ||
06e28de2 | 661 | bb = BASIC_BLOCK_FOR_FN (cfun, i); |
672987e8 ZD |
662 | if (!bb) |
663 | continue; | |
664 | ||
665 | retval |= cleanup_tree_cfg_bb (bb); | |
666 | ||
667 | /* Rerun split_bbs_on_noreturn_calls, in case we have altered any noreturn | |
668 | calls. */ | |
669 | retval |= split_bbs_on_noreturn_calls (); | |
670 | } | |
b8698a0f | 671 | |
672987e8 ZD |
672 | end_recording_case_labels (); |
673 | BITMAP_FREE (cfgcleanup_altered_bbs); | |
89e80dd4 DN |
674 | return retval; |
675 | } | |
676 | ||
677 | ||
e3594cb3 DN |
678 | /* Remove unreachable blocks and other miscellaneous clean up work. |
679 | Return true if the flowgraph was modified, false otherwise. */ | |
89e80dd4 | 680 | |
592c303d ZD |
681 | static bool |
682 | cleanup_tree_cfg_noloop (void) | |
89e80dd4 | 683 | { |
672987e8 | 684 | bool changed; |
89e80dd4 DN |
685 | |
686 | timevar_push (TV_TREE_CLEANUP_CFG); | |
687 | ||
e3594cb3 | 688 | /* Iterate until there are no more cleanups left to do. If any |
672987e8 ZD |
689 | iteration changed the flowgraph, set CHANGED to true. |
690 | ||
691 | If dominance information is available, there cannot be any unreachable | |
692 | blocks. */ | |
2b28c07a | 693 | if (!dom_info_available_p (CDI_DOMINATORS)) |
e3594cb3 | 694 | { |
672987e8 ZD |
695 | changed = delete_unreachable_blocks (); |
696 | calculate_dominance_info (CDI_DOMINATORS); | |
e3594cb3 | 697 | } |
672987e8 | 698 | else |
30251f7a ZD |
699 | { |
700 | #ifdef ENABLE_CHECKING | |
701 | verify_dominators (CDI_DOMINATORS); | |
702 | #endif | |
703 | changed = false; | |
704 | } | |
c9784e6d | 705 | |
672987e8 ZD |
706 | changed |= cleanup_tree_cfg_1 (); |
707 | ||
2b28c07a | 708 | gcc_assert (dom_info_available_p (CDI_DOMINATORS)); |
c9784e6d KH |
709 | compact_blocks (); |
710 | ||
711 | #ifdef ENABLE_CHECKING | |
712 | verify_flow_info (); | |
713 | #endif | |
89e80dd4 | 714 | |
c9784e6d | 715 | timevar_pop (TV_TREE_CLEANUP_CFG); |
89e80dd4 | 716 | |
592c303d | 717 | if (changed && current_loops) |
f87000d0 | 718 | loops_state_set (LOOPS_NEED_FIXUP); |
592c303d | 719 | |
e3594cb3 | 720 | return changed; |
c9784e6d KH |
721 | } |
722 | ||
592c303d | 723 | /* Repairs loop structures. */ |
c9784e6d | 724 | |
592c303d ZD |
725 | static void |
726 | repair_loop_structures (void) | |
c9784e6d | 727 | { |
a222c01a | 728 | bitmap changed_bbs; |
8e89b5b5 | 729 | unsigned n_new_loops; |
a222c01a | 730 | |
cc360b36 SB |
731 | calculate_dominance_info (CDI_DOMINATORS); |
732 | ||
a222c01a MM |
733 | timevar_push (TV_REPAIR_LOOPS); |
734 | changed_bbs = BITMAP_ALLOC (NULL); | |
8e89b5b5 | 735 | n_new_loops = fix_loop_structure (changed_bbs); |
c9784e6d | 736 | |
592c303d ZD |
737 | /* This usually does nothing. But sometimes parts of cfg that originally |
738 | were inside a loop get out of it due to edge removal (since they | |
8e89b5b5 RB |
739 | become unreachable by back edges from latch). Also a former |
740 | irreducible loop can become reducible - in this case force a full | |
741 | rewrite into loop-closed SSA form. */ | |
f87000d0 | 742 | if (loops_state_satisfies_p (LOOP_CLOSED_SSA)) |
8e89b5b5 RB |
743 | rewrite_into_loop_closed_ssa (n_new_loops ? NULL : changed_bbs, |
744 | TODO_update_ssa); | |
c9784e6d | 745 | |
592c303d | 746 | BITMAP_FREE (changed_bbs); |
c9784e6d KH |
747 | |
748 | #ifdef ENABLE_CHECKING | |
592c303d | 749 | verify_loop_structure (); |
c9784e6d | 750 | #endif |
592c303d ZD |
751 | scev_reset (); |
752 | ||
a222c01a | 753 | timevar_pop (TV_REPAIR_LOOPS); |
592c303d ZD |
754 | } |
755 | ||
756 | /* Cleanup cfg and repair loop structures. */ | |
757 | ||
758 | bool | |
759 | cleanup_tree_cfg (void) | |
760 | { | |
761 | bool changed = cleanup_tree_cfg_noloop (); | |
762 | ||
763 | if (current_loops != NULL | |
f87000d0 | 764 | && loops_state_satisfies_p (LOOPS_NEED_FIXUP)) |
592c303d ZD |
765 | repair_loop_structures (); |
766 | ||
1994bfea | 767 | return changed; |
c9784e6d KH |
768 | } |
769 | ||
a9e0d843 RB |
770 | /* Tries to merge the PHI nodes at BB into those at BB's sole successor. |
771 | Returns true if successful. */ | |
c9784e6d | 772 | |
a9e0d843 | 773 | static bool |
c9784e6d KH |
774 | remove_forwarder_block_with_phi (basic_block bb) |
775 | { | |
776 | edge succ = single_succ_edge (bb); | |
777 | basic_block dest = succ->dest; | |
726a989a | 778 | gimple label; |
c9784e6d KH |
779 | basic_block dombb, domdest, dom; |
780 | ||
781 | /* We check for infinite loops already in tree_forwarder_block_p. | |
782 | However it may happen that the infinite loop is created | |
783 | afterwards due to removal of forwarders. */ | |
784 | if (dest == bb) | |
a9e0d843 | 785 | return false; |
c9784e6d KH |
786 | |
787 | /* If the destination block consists of a nonlocal label, do not | |
788 | merge it. */ | |
789 | label = first_stmt (dest); | |
790 | if (label | |
726a989a RB |
791 | && gimple_code (label) == GIMPLE_LABEL |
792 | && DECL_NONLOCAL (gimple_label_label (label))) | |
a9e0d843 | 793 | return false; |
c9784e6d KH |
794 | |
795 | /* Redirect each incoming edge to BB to DEST. */ | |
796 | while (EDGE_COUNT (bb->preds) > 0) | |
797 | { | |
798 | edge e = EDGE_PRED (bb, 0), s; | |
726a989a | 799 | gimple_stmt_iterator gsi; |
c9784e6d KH |
800 | |
801 | s = find_edge (e->src, dest); | |
802 | if (s) | |
803 | { | |
804 | /* We already have an edge S from E->src to DEST. If S and | |
805 | E->dest's sole successor edge have the same PHI arguments | |
806 | at DEST, redirect S to DEST. */ | |
807 | if (phi_alternatives_equal (dest, s, succ)) | |
808 | { | |
809 | e = redirect_edge_and_branch (e, dest); | |
ea7e6d5a | 810 | redirect_edge_var_map_clear (e); |
c9784e6d KH |
811 | continue; |
812 | } | |
813 | ||
814 | /* PHI arguments are different. Create a forwarder block by | |
815 | splitting E so that we can merge PHI arguments on E to | |
816 | DEST. */ | |
817 | e = single_succ_edge (split_edge (e)); | |
818 | } | |
819 | ||
820 | s = redirect_edge_and_branch (e, dest); | |
821 | ||
822 | /* redirect_edge_and_branch must not create a new edge. */ | |
823 | gcc_assert (s == e); | |
824 | ||
825 | /* Add to the PHI nodes at DEST each PHI argument removed at the | |
826 | destination of E. */ | |
726a989a RB |
827 | for (gsi = gsi_start_phis (dest); |
828 | !gsi_end_p (gsi); | |
829 | gsi_next (&gsi)) | |
c9784e6d | 830 | { |
726a989a RB |
831 | gimple phi = gsi_stmt (gsi); |
832 | tree def = gimple_phi_arg_def (phi, succ->dest_idx); | |
f5045c96 | 833 | source_location locus = gimple_phi_arg_location_from_edge (phi, succ); |
c9784e6d KH |
834 | |
835 | if (TREE_CODE (def) == SSA_NAME) | |
836 | { | |
9771b263 | 837 | edge_var_map_vector *head; |
ea7e6d5a AH |
838 | edge_var_map *vm; |
839 | size_t i; | |
c9784e6d KH |
840 | |
841 | /* If DEF is one of the results of PHI nodes removed during | |
842 | redirection, replace it with the PHI argument that used | |
843 | to be on E. */ | |
ea7e6d5a | 844 | head = redirect_edge_var_map_vector (e); |
6fa5e0ed | 845 | FOR_EACH_VEC_SAFE_ELT (head, i, vm) |
c9784e6d | 846 | { |
ea7e6d5a AH |
847 | tree old_arg = redirect_edge_var_map_result (vm); |
848 | tree new_arg = redirect_edge_var_map_def (vm); | |
c9784e6d KH |
849 | |
850 | if (def == old_arg) | |
851 | { | |
852 | def = new_arg; | |
f5045c96 | 853 | locus = redirect_edge_var_map_location (vm); |
c9784e6d KH |
854 | break; |
855 | } | |
856 | } | |
857 | } | |
858 | ||
9e227d60 | 859 | add_phi_arg (phi, def, s, locus); |
c9784e6d KH |
860 | } |
861 | ||
ea7e6d5a | 862 | redirect_edge_var_map_clear (e); |
c9784e6d KH |
863 | } |
864 | ||
865 | /* Update the dominators. */ | |
866 | dombb = get_immediate_dominator (CDI_DOMINATORS, bb); | |
867 | domdest = get_immediate_dominator (CDI_DOMINATORS, dest); | |
868 | if (domdest == bb) | |
869 | { | |
870 | /* Shortcut to avoid calling (relatively expensive) | |
871 | nearest_common_dominator unless necessary. */ | |
872 | dom = dombb; | |
873 | } | |
874 | else | |
875 | dom = nearest_common_dominator (CDI_DOMINATORS, domdest, dombb); | |
876 | ||
877 | set_immediate_dominator (CDI_DOMINATORS, dest, dom); | |
878 | ||
879 | /* Remove BB since all of BB's incoming edges have been redirected | |
880 | to DEST. */ | |
881 | delete_basic_block (bb); | |
a9e0d843 RB |
882 | |
883 | return true; | |
c9784e6d KH |
884 | } |
885 | ||
886 | /* This pass merges PHI nodes if one feeds into another. For example, | |
887 | suppose we have the following: | |
888 | ||
889 | goto <bb 9> (<L9>); | |
890 | ||
891 | <L8>:; | |
892 | tem_17 = foo (); | |
893 | ||
894 | # tem_6 = PHI <tem_17(8), tem_23(7)>; | |
895 | <L9>:; | |
896 | ||
897 | # tem_3 = PHI <tem_6(9), tem_2(5)>; | |
898 | <L10>:; | |
899 | ||
900 | Then we merge the first PHI node into the second one like so: | |
901 | ||
902 | goto <bb 9> (<L10>); | |
903 | ||
904 | <L8>:; | |
905 | tem_17 = foo (); | |
906 | ||
907 | # tem_3 = PHI <tem_23(7), tem_2(5), tem_17(8)>; | |
908 | <L10>:; | |
909 | */ | |
910 | ||
c2924966 | 911 | static unsigned int |
c9784e6d KH |
912 | merge_phi_nodes (void) |
913 | { | |
0cae8d31 | 914 | basic_block *worklist = XNEWVEC (basic_block, n_basic_blocks_for_fn (cfun)); |
c9784e6d KH |
915 | basic_block *current = worklist; |
916 | basic_block bb; | |
917 | ||
918 | calculate_dominance_info (CDI_DOMINATORS); | |
919 | ||
920 | /* Find all PHI nodes that we may be able to merge. */ | |
11cd3bed | 921 | FOR_EACH_BB_FN (bb, cfun) |
c9784e6d KH |
922 | { |
923 | basic_block dest; | |
924 | ||
925 | /* Look for a forwarder block with PHI nodes. */ | |
926 | if (!tree_forwarder_block_p (bb, true)) | |
927 | continue; | |
928 | ||
929 | dest = single_succ (bb); | |
930 | ||
931 | /* We have to feed into another basic block with PHI | |
932 | nodes. */ | |
8eacd016 | 933 | if (gimple_seq_empty_p (phi_nodes (dest)) |
c9784e6d KH |
934 | /* We don't want to deal with a basic block with |
935 | abnormal edges. */ | |
31ff2426 | 936 | || bb_has_abnormal_pred (bb)) |
c9784e6d KH |
937 | continue; |
938 | ||
939 | if (!dominated_by_p (CDI_DOMINATORS, dest, bb)) | |
940 | { | |
941 | /* If BB does not dominate DEST, then the PHI nodes at | |
942 | DEST must be the only users of the results of the PHI | |
943 | nodes at BB. */ | |
944 | *current++ = bb; | |
945 | } | |
ea65cd37 JL |
946 | else |
947 | { | |
726a989a | 948 | gimple_stmt_iterator gsi; |
338b5886 | 949 | unsigned int dest_idx = single_succ_edge (bb)->dest_idx; |
ea65cd37 JL |
950 | |
951 | /* BB dominates DEST. There may be many users of the PHI | |
952 | nodes in BB. However, there is still a trivial case we | |
953 | can handle. If the result of every PHI in BB is used | |
954 | only by a PHI in DEST, then we can trivially merge the | |
955 | PHI nodes from BB into DEST. */ | |
726a989a RB |
956 | for (gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
957 | gsi_next (&gsi)) | |
ea65cd37 | 958 | { |
726a989a RB |
959 | gimple phi = gsi_stmt (gsi); |
960 | tree result = gimple_phi_result (phi); | |
ea65cd37 | 961 | use_operand_p imm_use; |
726a989a | 962 | gimple use_stmt; |
ea65cd37 JL |
963 | |
964 | /* If the PHI's result is never used, then we can just | |
965 | ignore it. */ | |
bfc646bf | 966 | if (has_zero_uses (result)) |
ea65cd37 JL |
967 | continue; |
968 | ||
969 | /* Get the single use of the result of this PHI node. */ | |
970 | if (!single_imm_use (result, &imm_use, &use_stmt) | |
726a989a RB |
971 | || gimple_code (use_stmt) != GIMPLE_PHI |
972 | || gimple_bb (use_stmt) != dest | |
973 | || gimple_phi_arg_def (use_stmt, dest_idx) != result) | |
ea65cd37 JL |
974 | break; |
975 | } | |
976 | ||
c0220ea4 | 977 | /* If the loop above iterated through all the PHI nodes |
ea65cd37 | 978 | in BB, then we can merge the PHIs from BB into DEST. */ |
726a989a | 979 | if (gsi_end_p (gsi)) |
ea65cd37 JL |
980 | *current++ = bb; |
981 | } | |
c9784e6d KH |
982 | } |
983 | ||
984 | /* Now let's drain WORKLIST. */ | |
a9e0d843 | 985 | bool changed = false; |
c9784e6d KH |
986 | while (current != worklist) |
987 | { | |
988 | bb = *--current; | |
a9e0d843 | 989 | changed |= remove_forwarder_block_with_phi (bb); |
c9784e6d | 990 | } |
c9784e6d | 991 | free (worklist); |
a9e0d843 RB |
992 | |
993 | /* Removing forwarder blocks can cause formerly irreducible loops | |
994 | to become reducible if we merged two entry blocks. */ | |
995 | if (changed | |
996 | && current_loops) | |
997 | loops_state_set (LOOPS_NEED_FIXUP); | |
998 | ||
c2924966 | 999 | return 0; |
c9784e6d KH |
1000 | } |
1001 | ||
1002 | static bool | |
1003 | gate_merge_phi (void) | |
1004 | { | |
1005 | return 1; | |
1006 | } | |
1007 | ||
27a4cd48 DM |
1008 | namespace { |
1009 | ||
1010 | const pass_data pass_data_merge_phi = | |
8ddbbcae | 1011 | { |
27a4cd48 DM |
1012 | GIMPLE_PASS, /* type */ |
1013 | "mergephi", /* name */ | |
1014 | OPTGROUP_NONE, /* optinfo_flags */ | |
1015 | true, /* has_gate */ | |
1016 | true, /* has_execute */ | |
1017 | TV_TREE_MERGE_PHI, /* tv_id */ | |
1018 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1019 | 0, /* properties_provided */ | |
1020 | 0, /* properties_destroyed */ | |
1021 | 0, /* todo_flags_start */ | |
1022 | TODO_verify_ssa, /* todo_flags_finish */ | |
c9784e6d | 1023 | }; |
27a4cd48 DM |
1024 | |
1025 | class pass_merge_phi : public gimple_opt_pass | |
1026 | { | |
1027 | public: | |
c3284718 RS |
1028 | pass_merge_phi (gcc::context *ctxt) |
1029 | : gimple_opt_pass (pass_data_merge_phi, ctxt) | |
27a4cd48 DM |
1030 | {} |
1031 | ||
1032 | /* opt_pass methods: */ | |
65d3284b | 1033 | opt_pass * clone () { return new pass_merge_phi (m_ctxt); } |
27a4cd48 DM |
1034 | bool gate () { return gate_merge_phi (); } |
1035 | unsigned int execute () { return merge_phi_nodes (); } | |
1036 | ||
1037 | }; // class pass_merge_phi | |
1038 | ||
1039 | } // anon namespace | |
1040 | ||
1041 | gimple_opt_pass * | |
1042 | make_pass_merge_phi (gcc::context *ctxt) | |
1043 | { | |
1044 | return new pass_merge_phi (ctxt); | |
1045 | } | |
4484a35a AM |
1046 | |
1047 | /* Pass: cleanup the CFG just before expanding trees to RTL. | |
1048 | This is just a round of label cleanups and case node grouping | |
1049 | because after the tree optimizers have run such cleanups may | |
1050 | be necessary. */ | |
1051 | ||
1052 | static unsigned int | |
1053 | execute_cleanup_cfg_post_optimizing (void) | |
1054 | { | |
1055 | unsigned int todo = 0; | |
1056 | if (cleanup_tree_cfg ()) | |
1057 | todo |= TODO_update_ssa; | |
1058 | maybe_remove_unreachable_handlers (); | |
1059 | cleanup_dead_labels (); | |
1060 | group_case_labels (); | |
1061 | if ((flag_compare_debug_opt || flag_compare_debug) | |
1062 | && flag_dump_final_insns) | |
1063 | { | |
1064 | FILE *final_output = fopen (flag_dump_final_insns, "a"); | |
1065 | ||
1066 | if (!final_output) | |
1067 | { | |
1068 | error ("could not open final insn dump file %qs: %m", | |
1069 | flag_dump_final_insns); | |
1070 | flag_dump_final_insns = NULL; | |
1071 | } | |
1072 | else | |
1073 | { | |
1074 | int save_unnumbered = flag_dump_unnumbered; | |
1075 | int save_noaddr = flag_dump_noaddr; | |
1076 | ||
1077 | flag_dump_noaddr = flag_dump_unnumbered = 1; | |
1078 | fprintf (final_output, "\n"); | |
1079 | dump_enumerated_decls (final_output, dump_flags | TDF_NOUID); | |
1080 | flag_dump_noaddr = save_noaddr; | |
1081 | flag_dump_unnumbered = save_unnumbered; | |
1082 | if (fclose (final_output)) | |
1083 | { | |
1084 | error ("could not close final insn dump file %qs: %m", | |
1085 | flag_dump_final_insns); | |
1086 | flag_dump_final_insns = NULL; | |
1087 | } | |
1088 | } | |
1089 | } | |
1090 | return todo; | |
1091 | } | |
1092 | ||
1093 | namespace { | |
1094 | ||
1095 | const pass_data pass_data_cleanup_cfg_post_optimizing = | |
1096 | { | |
1097 | GIMPLE_PASS, /* type */ | |
1098 | "optimized", /* name */ | |
1099 | OPTGROUP_NONE, /* optinfo_flags */ | |
1100 | false, /* has_gate */ | |
1101 | true, /* has_execute */ | |
1102 | TV_TREE_CLEANUP_CFG, /* tv_id */ | |
1103 | PROP_cfg, /* properties_required */ | |
1104 | 0, /* properties_provided */ | |
1105 | 0, /* properties_destroyed */ | |
1106 | 0, /* todo_flags_start */ | |
1107 | TODO_remove_unused_locals, /* todo_flags_finish */ | |
1108 | }; | |
1109 | ||
1110 | class pass_cleanup_cfg_post_optimizing : public gimple_opt_pass | |
1111 | { | |
1112 | public: | |
1113 | pass_cleanup_cfg_post_optimizing (gcc::context *ctxt) | |
1114 | : gimple_opt_pass (pass_data_cleanup_cfg_post_optimizing, ctxt) | |
1115 | {} | |
1116 | ||
1117 | /* opt_pass methods: */ | |
1118 | unsigned int execute () { | |
1119 | return execute_cleanup_cfg_post_optimizing (); | |
1120 | } | |
1121 | ||
1122 | }; // class pass_cleanup_cfg_post_optimizing | |
1123 | ||
1124 | } // anon namespace | |
1125 | ||
1126 | gimple_opt_pass * | |
1127 | make_pass_cleanup_cfg_post_optimizing (gcc::context *ctxt) | |
1128 | { | |
1129 | return new pass_cleanup_cfg_post_optimizing (ctxt); | |
1130 | } | |
1131 | ||
1132 |