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6de9cd9a | 1 | /* Control flow functions for trees. |
43e05e45 | 2 | Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. |
6de9cd9a DN |
3 | Contributed by Diego Novillo <dnovillo@redhat.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 2, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING. If not, write to | |
19 | the Free Software Foundation, 59 Temple Place - Suite 330, | |
20 | Boston, MA 02111-1307, USA. */ | |
21 | ||
22 | #include "config.h" | |
23 | #include "system.h" | |
24 | #include "coretypes.h" | |
25 | #include "tm.h" | |
26 | #include "tree.h" | |
27 | #include "rtl.h" | |
28 | #include "tm_p.h" | |
29 | #include "hard-reg-set.h" | |
30 | #include "basic-block.h" | |
31 | #include "output.h" | |
32 | #include "errors.h" | |
33 | #include "flags.h" | |
34 | #include "function.h" | |
35 | #include "expr.h" | |
36 | #include "ggc.h" | |
37 | #include "langhooks.h" | |
38 | #include "diagnostic.h" | |
39 | #include "tree-flow.h" | |
40 | #include "timevar.h" | |
41 | #include "tree-dump.h" | |
42 | #include "tree-pass.h" | |
43 | #include "toplev.h" | |
44 | #include "except.h" | |
45 | #include "cfgloop.h" | |
42759f1e | 46 | #include "cfglayout.h" |
92b6dff3 | 47 | #include "hashtab.h" |
6de9cd9a DN |
48 | |
49 | /* This file contains functions for building the Control Flow Graph (CFG) | |
50 | for a function tree. */ | |
51 | ||
52 | /* Local declarations. */ | |
53 | ||
54 | /* Initial capacity for the basic block array. */ | |
55 | static const int initial_cfg_capacity = 20; | |
56 | ||
57 | /* Mapping of labels to their associated blocks. This can greatly speed up | |
58 | building of the CFG in code with lots of gotos. */ | |
59 | static GTY(()) varray_type label_to_block_map; | |
60 | ||
d6be0d7f JL |
61 | /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs |
62 | which use a particular edge. The CASE_LABEL_EXPRs are chained together | |
63 | via their TREE_CHAIN field, which we clear after we're done with the | |
64 | hash table to prevent problems with duplication of SWITCH_EXPRs. | |
92b6dff3 | 65 | |
d6be0d7f JL |
66 | Access to this list of CASE_LABEL_EXPRs allows us to efficiently |
67 | update the case vector in response to edge redirections. | |
92b6dff3 | 68 | |
d6be0d7f JL |
69 | Right now this table is set up and torn down at key points in the |
70 | compilation process. It would be nice if we could make the table | |
71 | more persistent. The key is getting notification of changes to | |
72 | the CFG (particularly edge removal, creation and redirection). */ | |
73 | ||
74 | struct edge_to_cases_elt | |
92b6dff3 JL |
75 | { |
76 | /* The edge itself. Necessary for hashing and equality tests. */ | |
77 | edge e; | |
78 | ||
d6be0d7f JL |
79 | /* The case labels associated with this edge. We link these up via |
80 | their TREE_CHAIN field, then we wipe out the TREE_CHAIN fields | |
81 | when we destroy the hash table. This prevents problems when copying | |
82 | SWITCH_EXPRs. */ | |
83 | tree case_labels; | |
92b6dff3 JL |
84 | }; |
85 | ||
d6be0d7f | 86 | static htab_t edge_to_cases; |
92b6dff3 | 87 | |
6de9cd9a DN |
88 | /* CFG statistics. */ |
89 | struct cfg_stats_d | |
90 | { | |
91 | long num_merged_labels; | |
92 | }; | |
93 | ||
94 | static struct cfg_stats_d cfg_stats; | |
95 | ||
96 | /* Nonzero if we found a computed goto while building basic blocks. */ | |
97 | static bool found_computed_goto; | |
98 | ||
99 | /* Basic blocks and flowgraphs. */ | |
100 | static basic_block create_bb (void *, void *, basic_block); | |
101 | static void create_block_annotation (basic_block); | |
102 | static void free_blocks_annotations (void); | |
103 | static void clear_blocks_annotations (void); | |
104 | static void make_blocks (tree); | |
105 | static void factor_computed_gotos (void); | |
6de9cd9a DN |
106 | |
107 | /* Edges. */ | |
108 | static void make_edges (void); | |
109 | static void make_ctrl_stmt_edges (basic_block); | |
110 | static void make_exit_edges (basic_block); | |
111 | static void make_cond_expr_edges (basic_block); | |
112 | static void make_switch_expr_edges (basic_block); | |
113 | static void make_goto_expr_edges (basic_block); | |
114 | static edge tree_redirect_edge_and_branch (edge, basic_block); | |
115 | static edge tree_try_redirect_by_replacing_jump (edge, basic_block); | |
116 | static void split_critical_edges (void); | |
d7f3fc19 | 117 | static bool remove_fallthru_edge (VEC(edge) *); |
6de9cd9a DN |
118 | |
119 | /* Various helpers. */ | |
120 | static inline bool stmt_starts_bb_p (tree, tree); | |
121 | static int tree_verify_flow_info (void); | |
122 | static void tree_make_forwarder_block (edge); | |
23ab2e4e | 123 | static bool tree_forwarder_block_p (basic_block, bool); |
6de9cd9a DN |
124 | static void tree_cfg2vcg (FILE *); |
125 | ||
126 | /* Flowgraph optimization and cleanup. */ | |
127 | static void tree_merge_blocks (basic_block, basic_block); | |
128 | static bool tree_can_merge_blocks_p (basic_block, basic_block); | |
129 | static void remove_bb (basic_block); | |
6de9cd9a DN |
130 | static bool cleanup_control_flow (void); |
131 | static bool cleanup_control_expr_graph (basic_block, block_stmt_iterator); | |
be477406 | 132 | static edge find_taken_edge_computed_goto (basic_block, tree); |
6de9cd9a DN |
133 | static edge find_taken_edge_cond_expr (basic_block, tree); |
134 | static edge find_taken_edge_switch_expr (basic_block, tree); | |
135 | static tree find_case_label_for_value (tree, tree); | |
136 | static bool phi_alternatives_equal (basic_block, edge, edge); | |
63bb59a3 | 137 | static bool cleanup_forwarder_blocks (void); |
6de9cd9a DN |
138 | |
139 | ||
140 | /*--------------------------------------------------------------------------- | |
141 | Create basic blocks | |
142 | ---------------------------------------------------------------------------*/ | |
143 | ||
144 | /* Entry point to the CFG builder for trees. TP points to the list of | |
145 | statements to be added to the flowgraph. */ | |
146 | ||
147 | static void | |
148 | build_tree_cfg (tree *tp) | |
149 | { | |
150 | /* Register specific tree functions. */ | |
151 | tree_register_cfg_hooks (); | |
152 | ||
153 | /* Initialize rbi_pool. */ | |
154 | alloc_rbi_pool (); | |
155 | ||
156 | /* Initialize the basic block array. */ | |
157 | init_flow (); | |
878f99d2 | 158 | profile_status = PROFILE_ABSENT; |
6de9cd9a DN |
159 | n_basic_blocks = 0; |
160 | last_basic_block = 0; | |
161 | VARRAY_BB_INIT (basic_block_info, initial_cfg_capacity, "basic_block_info"); | |
162 | memset ((void *) &cfg_stats, 0, sizeof (cfg_stats)); | |
163 | ||
164 | /* Build a mapping of labels to their associated blocks. */ | |
165 | VARRAY_BB_INIT (label_to_block_map, initial_cfg_capacity, | |
166 | "label to block map"); | |
167 | ||
168 | ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR; | |
169 | EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR; | |
170 | ||
171 | found_computed_goto = 0; | |
172 | make_blocks (*tp); | |
173 | ||
174 | /* Computed gotos are hell to deal with, especially if there are | |
175 | lots of them with a large number of destinations. So we factor | |
176 | them to a common computed goto location before we build the | |
177 | edge list. After we convert back to normal form, we will un-factor | |
178 | the computed gotos since factoring introduces an unwanted jump. */ | |
179 | if (found_computed_goto) | |
180 | factor_computed_gotos (); | |
181 | ||
f0b698c1 | 182 | /* Make sure there is always at least one block, even if it's empty. */ |
6de9cd9a DN |
183 | if (n_basic_blocks == 0) |
184 | create_empty_bb (ENTRY_BLOCK_PTR); | |
185 | ||
186 | create_block_annotation (ENTRY_BLOCK_PTR); | |
187 | create_block_annotation (EXIT_BLOCK_PTR); | |
188 | ||
189 | /* Adjust the size of the array. */ | |
190 | VARRAY_GROW (basic_block_info, n_basic_blocks); | |
191 | ||
f667741c SB |
192 | /* To speed up statement iterator walks, we first purge dead labels. */ |
193 | cleanup_dead_labels (); | |
194 | ||
195 | /* Group case nodes to reduce the number of edges. | |
196 | We do this after cleaning up dead labels because otherwise we miss | |
197 | a lot of obvious case merging opportunities. */ | |
198 | group_case_labels (); | |
199 | ||
6de9cd9a DN |
200 | /* Create the edges of the flowgraph. */ |
201 | make_edges (); | |
202 | ||
203 | /* Debugging dumps. */ | |
204 | ||
205 | /* Write the flowgraph to a VCG file. */ | |
206 | { | |
207 | int local_dump_flags; | |
208 | FILE *dump_file = dump_begin (TDI_vcg, &local_dump_flags); | |
209 | if (dump_file) | |
210 | { | |
211 | tree_cfg2vcg (dump_file); | |
212 | dump_end (TDI_vcg, dump_file); | |
213 | } | |
214 | } | |
215 | ||
216 | /* Dump a textual representation of the flowgraph. */ | |
217 | if (dump_file) | |
218 | dump_tree_cfg (dump_file, dump_flags); | |
219 | } | |
220 | ||
221 | static void | |
222 | execute_build_cfg (void) | |
223 | { | |
224 | build_tree_cfg (&DECL_SAVED_TREE (current_function_decl)); | |
225 | } | |
226 | ||
227 | struct tree_opt_pass pass_build_cfg = | |
228 | { | |
229 | "cfg", /* name */ | |
230 | NULL, /* gate */ | |
231 | execute_build_cfg, /* execute */ | |
232 | NULL, /* sub */ | |
233 | NULL, /* next */ | |
234 | 0, /* static_pass_number */ | |
235 | TV_TREE_CFG, /* tv_id */ | |
236 | PROP_gimple_leh, /* properties_required */ | |
237 | PROP_cfg, /* properties_provided */ | |
238 | 0, /* properties_destroyed */ | |
239 | 0, /* todo_flags_start */ | |
9f8628ba PB |
240 | TODO_verify_stmts, /* todo_flags_finish */ |
241 | 0 /* letter */ | |
6de9cd9a DN |
242 | }; |
243 | ||
244 | /* Search the CFG for any computed gotos. If found, factor them to a | |
245 | common computed goto site. Also record the location of that site so | |
246 | that we can un-factor the gotos after we have converted back to | |
247 | normal form. */ | |
248 | ||
249 | static void | |
250 | factor_computed_gotos (void) | |
251 | { | |
252 | basic_block bb; | |
253 | tree factored_label_decl = NULL; | |
254 | tree var = NULL; | |
255 | tree factored_computed_goto_label = NULL; | |
256 | tree factored_computed_goto = NULL; | |
257 | ||
258 | /* We know there are one or more computed gotos in this function. | |
259 | Examine the last statement in each basic block to see if the block | |
260 | ends with a computed goto. */ | |
261 | ||
262 | FOR_EACH_BB (bb) | |
263 | { | |
264 | block_stmt_iterator bsi = bsi_last (bb); | |
265 | tree last; | |
266 | ||
267 | if (bsi_end_p (bsi)) | |
268 | continue; | |
269 | last = bsi_stmt (bsi); | |
270 | ||
271 | /* Ignore the computed goto we create when we factor the original | |
272 | computed gotos. */ | |
273 | if (last == factored_computed_goto) | |
274 | continue; | |
275 | ||
276 | /* If the last statement is a computed goto, factor it. */ | |
277 | if (computed_goto_p (last)) | |
278 | { | |
279 | tree assignment; | |
280 | ||
281 | /* The first time we find a computed goto we need to create | |
282 | the factored goto block and the variable each original | |
283 | computed goto will use for their goto destination. */ | |
284 | if (! factored_computed_goto) | |
285 | { | |
286 | basic_block new_bb = create_empty_bb (bb); | |
287 | block_stmt_iterator new_bsi = bsi_start (new_bb); | |
288 | ||
289 | /* Create the destination of the factored goto. Each original | |
290 | computed goto will put its desired destination into this | |
291 | variable and jump to the label we create immediately | |
292 | below. */ | |
293 | var = create_tmp_var (ptr_type_node, "gotovar"); | |
294 | ||
295 | /* Build a label for the new block which will contain the | |
296 | factored computed goto. */ | |
297 | factored_label_decl = create_artificial_label (); | |
298 | factored_computed_goto_label | |
299 | = build1 (LABEL_EXPR, void_type_node, factored_label_decl); | |
300 | bsi_insert_after (&new_bsi, factored_computed_goto_label, | |
301 | BSI_NEW_STMT); | |
302 | ||
303 | /* Build our new computed goto. */ | |
304 | factored_computed_goto = build1 (GOTO_EXPR, void_type_node, var); | |
305 | bsi_insert_after (&new_bsi, factored_computed_goto, | |
306 | BSI_NEW_STMT); | |
307 | } | |
308 | ||
309 | /* Copy the original computed goto's destination into VAR. */ | |
310 | assignment = build (MODIFY_EXPR, ptr_type_node, | |
311 | var, GOTO_DESTINATION (last)); | |
312 | bsi_insert_before (&bsi, assignment, BSI_SAME_STMT); | |
313 | ||
314 | /* And re-vector the computed goto to the new destination. */ | |
315 | GOTO_DESTINATION (last) = factored_label_decl; | |
316 | } | |
317 | } | |
318 | } | |
319 | ||
320 | ||
321 | /* Create annotations for a single basic block. */ | |
322 | ||
323 | static void | |
324 | create_block_annotation (basic_block bb) | |
325 | { | |
326 | /* Verify that the tree_annotations field is clear. */ | |
1e128c5f | 327 | gcc_assert (!bb->tree_annotations); |
6de9cd9a DN |
328 | bb->tree_annotations = ggc_alloc_cleared (sizeof (struct bb_ann_d)); |
329 | } | |
330 | ||
331 | ||
332 | /* Free the annotations for all the basic blocks. */ | |
333 | ||
334 | static void free_blocks_annotations (void) | |
335 | { | |
336 | clear_blocks_annotations (); | |
337 | } | |
338 | ||
339 | ||
340 | /* Clear the annotations for all the basic blocks. */ | |
341 | ||
342 | static void | |
343 | clear_blocks_annotations (void) | |
344 | { | |
345 | basic_block bb; | |
346 | ||
347 | FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR, NULL, next_bb) | |
348 | bb->tree_annotations = NULL; | |
349 | } | |
350 | ||
351 | ||
352 | /* Build a flowgraph for the statement_list STMT_LIST. */ | |
353 | ||
354 | static void | |
355 | make_blocks (tree stmt_list) | |
356 | { | |
357 | tree_stmt_iterator i = tsi_start (stmt_list); | |
358 | tree stmt = NULL; | |
359 | bool start_new_block = true; | |
360 | bool first_stmt_of_list = true; | |
361 | basic_block bb = ENTRY_BLOCK_PTR; | |
362 | ||
363 | while (!tsi_end_p (i)) | |
364 | { | |
365 | tree prev_stmt; | |
366 | ||
367 | prev_stmt = stmt; | |
368 | stmt = tsi_stmt (i); | |
369 | ||
370 | /* If the statement starts a new basic block or if we have determined | |
371 | in a previous pass that we need to create a new block for STMT, do | |
372 | so now. */ | |
373 | if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt)) | |
374 | { | |
375 | if (!first_stmt_of_list) | |
376 | stmt_list = tsi_split_statement_list_before (&i); | |
377 | bb = create_basic_block (stmt_list, NULL, bb); | |
378 | start_new_block = false; | |
379 | } | |
380 | ||
381 | /* Now add STMT to BB and create the subgraphs for special statement | |
382 | codes. */ | |
383 | set_bb_for_stmt (stmt, bb); | |
384 | ||
385 | if (computed_goto_p (stmt)) | |
386 | found_computed_goto = true; | |
387 | ||
388 | /* If STMT is a basic block terminator, set START_NEW_BLOCK for the | |
389 | next iteration. */ | |
390 | if (stmt_ends_bb_p (stmt)) | |
391 | start_new_block = true; | |
392 | ||
393 | tsi_next (&i); | |
394 | first_stmt_of_list = false; | |
395 | } | |
396 | } | |
397 | ||
398 | ||
399 | /* Create and return a new empty basic block after bb AFTER. */ | |
400 | ||
401 | static basic_block | |
402 | create_bb (void *h, void *e, basic_block after) | |
403 | { | |
404 | basic_block bb; | |
405 | ||
1e128c5f | 406 | gcc_assert (!e); |
6de9cd9a | 407 | |
27fd69fa KH |
408 | /* Create and initialize a new basic block. Since alloc_block uses |
409 | ggc_alloc_cleared to allocate a basic block, we do not have to | |
410 | clear the newly allocated basic block here. */ | |
6de9cd9a | 411 | bb = alloc_block (); |
6de9cd9a DN |
412 | |
413 | bb->index = last_basic_block; | |
414 | bb->flags = BB_NEW; | |
415 | bb->stmt_list = h ? h : alloc_stmt_list (); | |
416 | ||
417 | /* Add the new block to the linked list of blocks. */ | |
418 | link_block (bb, after); | |
419 | ||
420 | /* Grow the basic block array if needed. */ | |
421 | if ((size_t) last_basic_block == VARRAY_SIZE (basic_block_info)) | |
422 | { | |
423 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; | |
424 | VARRAY_GROW (basic_block_info, new_size); | |
425 | } | |
426 | ||
427 | /* Add the newly created block to the array. */ | |
428 | BASIC_BLOCK (last_basic_block) = bb; | |
429 | ||
430 | create_block_annotation (bb); | |
431 | ||
432 | n_basic_blocks++; | |
433 | last_basic_block++; | |
434 | ||
435 | initialize_bb_rbi (bb); | |
436 | return bb; | |
437 | } | |
438 | ||
439 | ||
440 | /*--------------------------------------------------------------------------- | |
441 | Edge creation | |
442 | ---------------------------------------------------------------------------*/ | |
443 | ||
fca01525 KH |
444 | /* Fold COND_EXPR_COND of each COND_EXPR. */ |
445 | ||
446 | static void | |
447 | fold_cond_expr_cond (void) | |
448 | { | |
449 | basic_block bb; | |
450 | ||
451 | FOR_EACH_BB (bb) | |
452 | { | |
453 | tree stmt = last_stmt (bb); | |
454 | ||
455 | if (stmt | |
456 | && TREE_CODE (stmt) == COND_EXPR) | |
457 | { | |
458 | tree cond = fold (COND_EXPR_COND (stmt)); | |
459 | if (integer_zerop (cond)) | |
460 | COND_EXPR_COND (stmt) = integer_zero_node; | |
461 | else if (integer_onep (cond)) | |
462 | COND_EXPR_COND (stmt) = integer_one_node; | |
463 | } | |
464 | } | |
465 | } | |
466 | ||
6de9cd9a DN |
467 | /* Join all the blocks in the flowgraph. */ |
468 | ||
469 | static void | |
470 | make_edges (void) | |
471 | { | |
472 | basic_block bb; | |
6de9cd9a DN |
473 | |
474 | /* Create an edge from entry to the first block with executable | |
475 | statements in it. */ | |
476 | make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (0), EDGE_FALLTHRU); | |
477 | ||
adb35797 | 478 | /* Traverse the basic block array placing edges. */ |
6de9cd9a DN |
479 | FOR_EACH_BB (bb) |
480 | { | |
481 | tree first = first_stmt (bb); | |
482 | tree last = last_stmt (bb); | |
483 | ||
484 | if (first) | |
485 | { | |
486 | /* Edges for statements that always alter flow control. */ | |
487 | if (is_ctrl_stmt (last)) | |
488 | make_ctrl_stmt_edges (bb); | |
489 | ||
490 | /* Edges for statements that sometimes alter flow control. */ | |
491 | if (is_ctrl_altering_stmt (last)) | |
492 | make_exit_edges (bb); | |
493 | } | |
494 | ||
495 | /* Finally, if no edges were created above, this is a regular | |
496 | basic block that only needs a fallthru edge. */ | |
628f6a4e | 497 | if (EDGE_COUNT (bb->succs) == 0) |
6de9cd9a DN |
498 | make_edge (bb, bb->next_bb, EDGE_FALLTHRU); |
499 | } | |
500 | ||
6de9cd9a DN |
501 | /* We do not care about fake edges, so remove any that the CFG |
502 | builder inserted for completeness. */ | |
6809cbf9 | 503 | remove_fake_exit_edges (); |
6de9cd9a | 504 | |
fca01525 KH |
505 | /* Fold COND_EXPR_COND of each COND_EXPR. */ |
506 | fold_cond_expr_cond (); | |
507 | ||
6de9cd9a DN |
508 | /* Clean up the graph and warn for unreachable code. */ |
509 | cleanup_tree_cfg (); | |
510 | } | |
511 | ||
512 | ||
513 | /* Create edges for control statement at basic block BB. */ | |
514 | ||
515 | static void | |
516 | make_ctrl_stmt_edges (basic_block bb) | |
517 | { | |
518 | tree last = last_stmt (bb); | |
6de9cd9a | 519 | |
1e128c5f | 520 | gcc_assert (last); |
6de9cd9a DN |
521 | switch (TREE_CODE (last)) |
522 | { | |
523 | case GOTO_EXPR: | |
524 | make_goto_expr_edges (bb); | |
525 | break; | |
526 | ||
527 | case RETURN_EXPR: | |
528 | make_edge (bb, EXIT_BLOCK_PTR, 0); | |
529 | break; | |
530 | ||
531 | case COND_EXPR: | |
532 | make_cond_expr_edges (bb); | |
533 | break; | |
534 | ||
535 | case SWITCH_EXPR: | |
536 | make_switch_expr_edges (bb); | |
537 | break; | |
538 | ||
539 | case RESX_EXPR: | |
540 | make_eh_edges (last); | |
541 | /* Yet another NORETURN hack. */ | |
628f6a4e | 542 | if (EDGE_COUNT (bb->succs) == 0) |
6de9cd9a DN |
543 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); |
544 | break; | |
545 | ||
546 | default: | |
1e128c5f | 547 | gcc_unreachable (); |
6de9cd9a DN |
548 | } |
549 | } | |
550 | ||
551 | ||
552 | /* Create exit edges for statements in block BB that alter the flow of | |
553 | control. Statements that alter the control flow are 'goto', 'return' | |
554 | and calls to non-returning functions. */ | |
555 | ||
556 | static void | |
557 | make_exit_edges (basic_block bb) | |
558 | { | |
cd709752 | 559 | tree last = last_stmt (bb), op; |
6de9cd9a | 560 | |
1e128c5f | 561 | gcc_assert (last); |
6de9cd9a DN |
562 | switch (TREE_CODE (last)) |
563 | { | |
564 | case CALL_EXPR: | |
565 | /* If this function receives a nonlocal goto, then we need to | |
566 | make edges from this call site to all the nonlocal goto | |
567 | handlers. */ | |
568 | if (TREE_SIDE_EFFECTS (last) | |
569 | && current_function_has_nonlocal_label) | |
570 | make_goto_expr_edges (bb); | |
571 | ||
572 | /* If this statement has reachable exception handlers, then | |
573 | create abnormal edges to them. */ | |
574 | make_eh_edges (last); | |
575 | ||
576 | /* Some calls are known not to return. For such calls we create | |
577 | a fake edge. | |
578 | ||
579 | We really need to revamp how we build edges so that it's not | |
580 | such a bloody pain to avoid creating edges for this case since | |
581 | all we do is remove these edges when we're done building the | |
582 | CFG. */ | |
6e14af16 | 583 | if (call_expr_flags (last) & ECF_NORETURN) |
6de9cd9a DN |
584 | { |
585 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
586 | return; | |
587 | } | |
588 | ||
589 | /* Don't forget the fall-thru edge. */ | |
590 | make_edge (bb, bb->next_bb, EDGE_FALLTHRU); | |
591 | break; | |
592 | ||
593 | case MODIFY_EXPR: | |
594 | /* A MODIFY_EXPR may have a CALL_EXPR on its RHS and the CALL_EXPR | |
595 | may have an abnormal edge. Search the RHS for this case and | |
596 | create any required edges. */ | |
cd709752 RH |
597 | op = get_call_expr_in (last); |
598 | if (op && TREE_SIDE_EFFECTS (op) | |
6de9cd9a DN |
599 | && current_function_has_nonlocal_label) |
600 | make_goto_expr_edges (bb); | |
601 | ||
602 | make_eh_edges (last); | |
603 | make_edge (bb, bb->next_bb, EDGE_FALLTHRU); | |
604 | break; | |
605 | ||
606 | default: | |
1e128c5f | 607 | gcc_unreachable (); |
6de9cd9a DN |
608 | } |
609 | } | |
610 | ||
611 | ||
612 | /* Create the edges for a COND_EXPR starting at block BB. | |
613 | At this point, both clauses must contain only simple gotos. */ | |
614 | ||
615 | static void | |
616 | make_cond_expr_edges (basic_block bb) | |
617 | { | |
618 | tree entry = last_stmt (bb); | |
619 | basic_block then_bb, else_bb; | |
620 | tree then_label, else_label; | |
621 | ||
1e128c5f GB |
622 | gcc_assert (entry); |
623 | gcc_assert (TREE_CODE (entry) == COND_EXPR); | |
6de9cd9a DN |
624 | |
625 | /* Entry basic blocks for each component. */ | |
626 | then_label = GOTO_DESTINATION (COND_EXPR_THEN (entry)); | |
627 | else_label = GOTO_DESTINATION (COND_EXPR_ELSE (entry)); | |
628 | then_bb = label_to_block (then_label); | |
629 | else_bb = label_to_block (else_label); | |
630 | ||
631 | make_edge (bb, then_bb, EDGE_TRUE_VALUE); | |
632 | make_edge (bb, else_bb, EDGE_FALSE_VALUE); | |
633 | } | |
634 | ||
d6be0d7f | 635 | /* Hashing routine for EDGE_TO_CASES. */ |
92b6dff3 JL |
636 | |
637 | static hashval_t | |
d6be0d7f | 638 | edge_to_cases_hash (const void *p) |
92b6dff3 | 639 | { |
d6be0d7f | 640 | edge e = ((struct edge_to_cases_elt *)p)->e; |
92b6dff3 JL |
641 | |
642 | /* Hash on the edge itself (which is a pointer). */ | |
643 | return htab_hash_pointer (e); | |
644 | } | |
645 | ||
d6be0d7f | 646 | /* Equality routine for EDGE_TO_CASES, edges are unique, so testing |
92b6dff3 JL |
647 | for equality is just a pointer comparison. */ |
648 | ||
649 | static int | |
d6be0d7f | 650 | edge_to_cases_eq (const void *p1, const void *p2) |
92b6dff3 | 651 | { |
d6be0d7f JL |
652 | edge e1 = ((struct edge_to_cases_elt *)p1)->e; |
653 | edge e2 = ((struct edge_to_cases_elt *)p2)->e; | |
92b6dff3 JL |
654 | |
655 | return e1 == e2; | |
656 | } | |
657 | ||
d6be0d7f JL |
658 | /* Called for each element in the hash table (P) as we delete the |
659 | edge to cases hash table. | |
660 | ||
661 | Clear all the TREE_CHAINs to prevent problems with copying of | |
662 | SWITCH_EXPRs and structure sharing rules, then free the hash table | |
663 | element. */ | |
664 | ||
665 | static void | |
666 | edge_to_cases_cleanup (void *p) | |
667 | { | |
668 | struct edge_to_cases_elt *elt = p; | |
669 | tree t, next; | |
670 | ||
671 | for (t = elt->case_labels; t; t = next) | |
672 | { | |
673 | next = TREE_CHAIN (t); | |
674 | TREE_CHAIN (t) = NULL; | |
675 | } | |
676 | free (p); | |
677 | } | |
678 | ||
679 | /* Start recording information mapping edges to case labels. */ | |
680 | ||
681 | static void | |
682 | start_recording_case_labels (void) | |
683 | { | |
684 | gcc_assert (edge_to_cases == NULL); | |
685 | ||
686 | edge_to_cases = htab_create (37, | |
687 | edge_to_cases_hash, | |
688 | edge_to_cases_eq, | |
689 | edge_to_cases_cleanup); | |
690 | } | |
691 | ||
692 | /* Return nonzero if we are recording information for case labels. */ | |
693 | ||
694 | static bool | |
695 | recording_case_labels_p (void) | |
696 | { | |
697 | return (edge_to_cases != NULL); | |
698 | } | |
699 | ||
700 | /* Stop recording information mapping edges to case labels and | |
701 | remove any information we have recorded. */ | |
702 | static void | |
703 | end_recording_case_labels (void) | |
704 | { | |
705 | htab_delete (edge_to_cases); | |
706 | edge_to_cases = NULL; | |
707 | } | |
708 | ||
92b6dff3 JL |
709 | /* Record that CASE_LABEL (a CASE_LABEL_EXPR) references edge E. */ |
710 | ||
711 | static void | |
712 | record_switch_edge (edge e, tree case_label) | |
713 | { | |
d6be0d7f | 714 | struct edge_to_cases_elt *elt; |
92b6dff3 JL |
715 | void **slot; |
716 | ||
717 | /* Build a hash table element so we can see if E is already | |
718 | in the table. */ | |
d6be0d7f | 719 | elt = xmalloc (sizeof (struct edge_to_cases_elt)); |
92b6dff3 | 720 | elt->e = e; |
d6be0d7f | 721 | elt->case_labels = case_label; |
92b6dff3 | 722 | |
d6be0d7f | 723 | slot = htab_find_slot (edge_to_cases, elt, INSERT); |
92b6dff3 JL |
724 | |
725 | if (*slot == NULL) | |
726 | { | |
727 | /* E was not in the hash table. Install E into the hash table. */ | |
728 | *slot = (void *)elt; | |
729 | } | |
730 | else | |
731 | { | |
732 | /* E was already in the hash table. Free ELT as we do not need it | |
733 | anymore. */ | |
734 | free (elt); | |
735 | ||
736 | /* Get the entry stored in the hash table. */ | |
d6be0d7f | 737 | elt = (struct edge_to_cases_elt *) *slot; |
92b6dff3 | 738 | |
d6be0d7f JL |
739 | /* Add it to the chain of CASE_LABEL_EXPRs referencing E. */ |
740 | TREE_CHAIN (case_label) = elt->case_labels; | |
741 | elt->case_labels = case_label; | |
92b6dff3 JL |
742 | } |
743 | } | |
744 | ||
d6be0d7f JL |
745 | /* If we are inside a {start,end}_recording_cases block, then return |
746 | a chain of CASE_LABEL_EXPRs from T which reference E. | |
747 | ||
748 | Otherwise return NULL. */ | |
92b6dff3 JL |
749 | |
750 | static tree | |
d6be0d7f | 751 | get_cases_for_edge (edge e, tree t) |
92b6dff3 | 752 | { |
d6be0d7f | 753 | struct edge_to_cases_elt elt, *elt_p; |
92b6dff3 | 754 | void **slot; |
d6be0d7f JL |
755 | size_t i, n; |
756 | tree vec; | |
92b6dff3 | 757 | |
d6be0d7f JL |
758 | /* If we are not recording cases, then we do not have CASE_LABEL_EXPR |
759 | chains available. Return NULL so the caller can detect this case. */ | |
760 | if (!recording_case_labels_p ()) | |
761 | return NULL; | |
762 | ||
763 | restart: | |
92b6dff3 | 764 | elt.e = e; |
d6be0d7f JL |
765 | elt.case_labels = NULL; |
766 | slot = htab_find_slot (edge_to_cases, &elt, NO_INSERT); | |
92b6dff3 JL |
767 | |
768 | if (slot) | |
769 | { | |
d6be0d7f JL |
770 | elt_p = (struct edge_to_cases_elt *)*slot; |
771 | return elt_p->case_labels; | |
92b6dff3 JL |
772 | } |
773 | ||
d6be0d7f JL |
774 | /* If we did not find E in the hash table, then this must be the first |
775 | time we have been queried for information about E & T. Add all the | |
776 | elements from T to the hash table then perform the query again. */ | |
92b6dff3 | 777 | |
d6be0d7f | 778 | vec = SWITCH_LABELS (t); |
92b6dff3 | 779 | n = TREE_VEC_LENGTH (vec); |
92b6dff3 JL |
780 | for (i = 0; i < n; i++) |
781 | { | |
d6be0d7f JL |
782 | tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i)); |
783 | basic_block label_bb = label_to_block (lab); | |
784 | record_switch_edge (find_edge (e->src, label_bb), TREE_VEC_ELT (vec, i)); | |
92b6dff3 | 785 | } |
d6be0d7f | 786 | goto restart; |
92b6dff3 | 787 | } |
6de9cd9a DN |
788 | |
789 | /* Create the edges for a SWITCH_EXPR starting at block BB. | |
790 | At this point, the switch body has been lowered and the | |
791 | SWITCH_LABELS filled in, so this is in effect a multi-way branch. */ | |
792 | ||
793 | static void | |
794 | make_switch_expr_edges (basic_block bb) | |
795 | { | |
796 | tree entry = last_stmt (bb); | |
797 | size_t i, n; | |
798 | tree vec; | |
799 | ||
800 | vec = SWITCH_LABELS (entry); | |
801 | n = TREE_VEC_LENGTH (vec); | |
802 | ||
803 | for (i = 0; i < n; ++i) | |
804 | { | |
805 | tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i)); | |
806 | basic_block label_bb = label_to_block (lab); | |
d6be0d7f | 807 | make_edge (bb, label_bb, 0); |
6de9cd9a DN |
808 | } |
809 | } | |
810 | ||
811 | ||
812 | /* Return the basic block holding label DEST. */ | |
813 | ||
814 | basic_block | |
815 | label_to_block (tree dest) | |
816 | { | |
242229bb JH |
817 | int uid = LABEL_DECL_UID (dest); |
818 | ||
f0b698c1 KH |
819 | /* We would die hard when faced by an undefined label. Emit a label to |
820 | the very first basic block. This will hopefully make even the dataflow | |
242229bb JH |
821 | and undefined variable warnings quite right. */ |
822 | if ((errorcount || sorrycount) && uid < 0) | |
823 | { | |
824 | block_stmt_iterator bsi = bsi_start (BASIC_BLOCK (0)); | |
825 | tree stmt; | |
826 | ||
827 | stmt = build1 (LABEL_EXPR, void_type_node, dest); | |
828 | bsi_insert_before (&bsi, stmt, BSI_NEW_STMT); | |
829 | uid = LABEL_DECL_UID (dest); | |
830 | } | |
831 | return VARRAY_BB (label_to_block_map, uid); | |
6de9cd9a DN |
832 | } |
833 | ||
834 | ||
835 | /* Create edges for a goto statement at block BB. */ | |
836 | ||
837 | static void | |
838 | make_goto_expr_edges (basic_block bb) | |
839 | { | |
7d3bf067 | 840 | tree goto_t; |
6de9cd9a DN |
841 | basic_block target_bb; |
842 | int for_call; | |
843 | block_stmt_iterator last = bsi_last (bb); | |
844 | ||
845 | goto_t = bsi_stmt (last); | |
846 | ||
847 | /* If the last statement is not a GOTO (i.e., it is a RETURN_EXPR, | |
848 | CALL_EXPR or MODIFY_EXPR), then the edge is an abnormal edge resulting | |
849 | from a nonlocal goto. */ | |
850 | if (TREE_CODE (goto_t) != GOTO_EXPR) | |
7d3bf067 | 851 | for_call = 1; |
6de9cd9a DN |
852 | else |
853 | { | |
7d3bf067 | 854 | tree dest = GOTO_DESTINATION (goto_t); |
6de9cd9a DN |
855 | for_call = 0; |
856 | ||
857 | /* A GOTO to a local label creates normal edges. */ | |
858 | if (simple_goto_p (goto_t)) | |
859 | { | |
62b857ea | 860 | edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU); |
9506ac2b PB |
861 | #ifdef USE_MAPPED_LOCATION |
862 | e->goto_locus = EXPR_LOCATION (goto_t); | |
863 | #else | |
62b857ea | 864 | e->goto_locus = EXPR_LOCUS (goto_t); |
9506ac2b | 865 | #endif |
6de9cd9a DN |
866 | bsi_remove (&last); |
867 | return; | |
868 | } | |
869 | ||
9cf737f8 | 870 | /* Nothing more to do for nonlocal gotos. */ |
6de9cd9a DN |
871 | if (TREE_CODE (dest) == LABEL_DECL) |
872 | return; | |
873 | ||
874 | /* Computed gotos remain. */ | |
875 | } | |
876 | ||
877 | /* Look for the block starting with the destination label. In the | |
878 | case of a computed goto, make an edge to any label block we find | |
879 | in the CFG. */ | |
880 | FOR_EACH_BB (target_bb) | |
881 | { | |
882 | block_stmt_iterator bsi; | |
883 | ||
884 | for (bsi = bsi_start (target_bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
885 | { | |
886 | tree target = bsi_stmt (bsi); | |
887 | ||
888 | if (TREE_CODE (target) != LABEL_EXPR) | |
889 | break; | |
890 | ||
891 | if ( | |
892 | /* Computed GOTOs. Make an edge to every label block that has | |
893 | been marked as a potential target for a computed goto. */ | |
894 | (FORCED_LABEL (LABEL_EXPR_LABEL (target)) && for_call == 0) | |
895 | /* Nonlocal GOTO target. Make an edge to every label block | |
896 | that has been marked as a potential target for a nonlocal | |
897 | goto. */ | |
898 | || (DECL_NONLOCAL (LABEL_EXPR_LABEL (target)) && for_call == 1)) | |
899 | { | |
900 | make_edge (bb, target_bb, EDGE_ABNORMAL); | |
901 | break; | |
902 | } | |
903 | } | |
904 | } | |
905 | ||
906 | /* Degenerate case of computed goto with no labels. */ | |
628f6a4e | 907 | if (!for_call && EDGE_COUNT (bb->succs) == 0) |
6de9cd9a DN |
908 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); |
909 | } | |
910 | ||
911 | ||
912 | /*--------------------------------------------------------------------------- | |
913 | Flowgraph analysis | |
914 | ---------------------------------------------------------------------------*/ | |
915 | ||
916 | /* Remove unreachable blocks and other miscellaneous clean up work. */ | |
917 | ||
56b043c8 | 918 | bool |
6de9cd9a DN |
919 | cleanup_tree_cfg (void) |
920 | { | |
56b043c8 | 921 | bool retval = false; |
6de9cd9a DN |
922 | |
923 | timevar_push (TV_TREE_CLEANUP_CFG); | |
924 | ||
8f28be81 | 925 | retval = cleanup_control_flow (); |
26d4492f | 926 | retval |= delete_unreachable_blocks (); |
d6be0d7f | 927 | |
63bb59a3 ZD |
928 | /* cleanup_forwarder_blocks can redirect edges out of SWITCH_EXPRs, |
929 | which can get expensive. So we want to enable recording of edge | |
930 | to CASE_LABEL_EXPR mappings around the call to | |
931 | cleanup_forwarder_blocks. */ | |
d6be0d7f | 932 | start_recording_case_labels (); |
63bb59a3 | 933 | retval |= cleanup_forwarder_blocks (); |
d6be0d7f | 934 | end_recording_case_labels (); |
6de9cd9a | 935 | |
8f28be81 KH |
936 | #ifdef ENABLE_CHECKING |
937 | if (retval) | |
26d4492f KH |
938 | { |
939 | gcc_assert (!cleanup_control_flow ()); | |
940 | gcc_assert (!delete_unreachable_blocks ()); | |
63bb59a3 | 941 | gcc_assert (!cleanup_forwarder_blocks ()); |
26d4492f | 942 | } |
8f28be81 KH |
943 | #endif |
944 | ||
6de9cd9a DN |
945 | /* Merging the blocks creates no new opportunities for the other |
946 | optimizations, so do it here. */ | |
086aa12e | 947 | retval |= merge_seq_blocks (); |
6de9cd9a DN |
948 | |
949 | compact_blocks (); | |
950 | ||
951 | #ifdef ENABLE_CHECKING | |
952 | verify_flow_info (); | |
953 | #endif | |
954 | timevar_pop (TV_TREE_CLEANUP_CFG); | |
56b043c8 | 955 | return retval; |
6de9cd9a DN |
956 | } |
957 | ||
958 | ||
2b271002 ZD |
959 | /* Cleanup cfg and repair loop structures. */ |
960 | ||
961 | void | |
962 | cleanup_tree_cfg_loop (void) | |
963 | { | |
964 | bitmap changed_bbs = BITMAP_ALLOC (NULL); | |
965 | ||
966 | cleanup_tree_cfg (); | |
967 | ||
968 | fix_loop_structure (current_loops, changed_bbs); | |
969 | calculate_dominance_info (CDI_DOMINATORS); | |
970 | ||
971 | /* This usually does nothing. But sometimes parts of cfg that originally | |
972 | were inside a loop get out of it due to edge removal (since they | |
973 | become unreachable by back edges from latch). */ | |
974 | rewrite_into_loop_closed_ssa (changed_bbs); | |
975 | ||
976 | BITMAP_FREE (changed_bbs); | |
977 | ||
978 | #ifdef ENABLE_CHECKING | |
979 | verify_loop_structure (current_loops); | |
980 | #endif | |
981 | } | |
982 | ||
f698d217 SB |
983 | /* Cleanup useless labels in basic blocks. This is something we wish |
984 | to do early because it allows us to group case labels before creating | |
985 | the edges for the CFG, and it speeds up block statement iterators in | |
986 | all passes later on. | |
987 | We only run this pass once, running it more than once is probably not | |
988 | profitable. */ | |
989 | ||
990 | /* A map from basic block index to the leading label of that block. */ | |
991 | static tree *label_for_bb; | |
992 | ||
993 | /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */ | |
994 | static void | |
995 | update_eh_label (struct eh_region *region) | |
996 | { | |
997 | tree old_label = get_eh_region_tree_label (region); | |
998 | if (old_label) | |
999 | { | |
165b54c3 SB |
1000 | tree new_label; |
1001 | basic_block bb = label_to_block (old_label); | |
1002 | ||
1003 | /* ??? After optimizing, there may be EH regions with labels | |
1004 | that have already been removed from the function body, so | |
1005 | there is no basic block for them. */ | |
1006 | if (! bb) | |
1007 | return; | |
1008 | ||
1009 | new_label = label_for_bb[bb->index]; | |
f698d217 SB |
1010 | set_eh_region_tree_label (region, new_label); |
1011 | } | |
1012 | } | |
1013 | ||
242229bb JH |
1014 | /* Given LABEL return the first label in the same basic block. */ |
1015 | static tree | |
1016 | main_block_label (tree label) | |
1017 | { | |
1018 | basic_block bb = label_to_block (label); | |
1019 | ||
1020 | /* label_to_block possibly inserted undefined label into the chain. */ | |
1021 | if (!label_for_bb[bb->index]) | |
1022 | label_for_bb[bb->index] = label; | |
1023 | return label_for_bb[bb->index]; | |
1024 | } | |
1025 | ||
b986ebf3 | 1026 | /* Cleanup redundant labels. This is a three-step process: |
f698d217 SB |
1027 | 1) Find the leading label for each block. |
1028 | 2) Redirect all references to labels to the leading labels. | |
1029 | 3) Cleanup all useless labels. */ | |
6de9cd9a | 1030 | |
165b54c3 | 1031 | void |
6de9cd9a DN |
1032 | cleanup_dead_labels (void) |
1033 | { | |
1034 | basic_block bb; | |
f698d217 | 1035 | label_for_bb = xcalloc (last_basic_block, sizeof (tree)); |
6de9cd9a DN |
1036 | |
1037 | /* Find a suitable label for each block. We use the first user-defined | |
f0b698c1 | 1038 | label if there is one, or otherwise just the first label we see. */ |
6de9cd9a DN |
1039 | FOR_EACH_BB (bb) |
1040 | { | |
1041 | block_stmt_iterator i; | |
1042 | ||
1043 | for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i)) | |
1044 | { | |
1045 | tree label, stmt = bsi_stmt (i); | |
1046 | ||
1047 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
1048 | break; | |
1049 | ||
1050 | label = LABEL_EXPR_LABEL (stmt); | |
1051 | ||
1052 | /* If we have not yet seen a label for the current block, | |
1053 | remember this one and see if there are more labels. */ | |
1054 | if (! label_for_bb[bb->index]) | |
1055 | { | |
1056 | label_for_bb[bb->index] = label; | |
1057 | continue; | |
1058 | } | |
1059 | ||
1060 | /* If we did see a label for the current block already, but it | |
1061 | is an artificially created label, replace it if the current | |
1062 | label is a user defined label. */ | |
1063 | if (! DECL_ARTIFICIAL (label) | |
1064 | && DECL_ARTIFICIAL (label_for_bb[bb->index])) | |
1065 | { | |
1066 | label_for_bb[bb->index] = label; | |
1067 | break; | |
1068 | } | |
1069 | } | |
1070 | } | |
1071 | ||
f698d217 SB |
1072 | /* Now redirect all jumps/branches to the selected label. |
1073 | First do so for each block ending in a control statement. */ | |
6de9cd9a DN |
1074 | FOR_EACH_BB (bb) |
1075 | { | |
1076 | tree stmt = last_stmt (bb); | |
1077 | if (!stmt) | |
1078 | continue; | |
1079 | ||
1080 | switch (TREE_CODE (stmt)) | |
1081 | { | |
1082 | case COND_EXPR: | |
1083 | { | |
1084 | tree true_branch, false_branch; | |
6de9cd9a DN |
1085 | |
1086 | true_branch = COND_EXPR_THEN (stmt); | |
1087 | false_branch = COND_EXPR_ELSE (stmt); | |
6de9cd9a | 1088 | |
242229bb JH |
1089 | GOTO_DESTINATION (true_branch) |
1090 | = main_block_label (GOTO_DESTINATION (true_branch)); | |
1091 | GOTO_DESTINATION (false_branch) | |
1092 | = main_block_label (GOTO_DESTINATION (false_branch)); | |
6de9cd9a DN |
1093 | |
1094 | break; | |
1095 | } | |
1096 | ||
1097 | case SWITCH_EXPR: | |
1098 | { | |
1099 | size_t i; | |
1100 | tree vec = SWITCH_LABELS (stmt); | |
1101 | size_t n = TREE_VEC_LENGTH (vec); | |
1102 | ||
1103 | /* Replace all destination labels. */ | |
1104 | for (i = 0; i < n; ++i) | |
92b6dff3 JL |
1105 | { |
1106 | tree elt = TREE_VEC_ELT (vec, i); | |
1107 | tree label = main_block_label (CASE_LABEL (elt)); | |
d6be0d7f | 1108 | CASE_LABEL (elt) = label; |
92b6dff3 | 1109 | } |
6de9cd9a DN |
1110 | break; |
1111 | } | |
1112 | ||
f667741c SB |
1113 | /* We have to handle GOTO_EXPRs until they're removed, and we don't |
1114 | remove them until after we've created the CFG edges. */ | |
1115 | case GOTO_EXPR: | |
242229bb JH |
1116 | if (! computed_goto_p (stmt)) |
1117 | { | |
1118 | GOTO_DESTINATION (stmt) | |
1119 | = main_block_label (GOTO_DESTINATION (stmt)); | |
1120 | break; | |
1121 | } | |
f667741c | 1122 | |
6de9cd9a DN |
1123 | default: |
1124 | break; | |
1125 | } | |
1126 | } | |
1127 | ||
f698d217 SB |
1128 | for_each_eh_region (update_eh_label); |
1129 | ||
6de9cd9a DN |
1130 | /* Finally, purge dead labels. All user-defined labels and labels that |
1131 | can be the target of non-local gotos are preserved. */ | |
1132 | FOR_EACH_BB (bb) | |
1133 | { | |
1134 | block_stmt_iterator i; | |
1135 | tree label_for_this_bb = label_for_bb[bb->index]; | |
1136 | ||
1137 | if (! label_for_this_bb) | |
1138 | continue; | |
1139 | ||
1140 | for (i = bsi_start (bb); !bsi_end_p (i); ) | |
1141 | { | |
1142 | tree label, stmt = bsi_stmt (i); | |
1143 | ||
1144 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
1145 | break; | |
1146 | ||
1147 | label = LABEL_EXPR_LABEL (stmt); | |
1148 | ||
1149 | if (label == label_for_this_bb | |
1150 | || ! DECL_ARTIFICIAL (label) | |
1151 | || DECL_NONLOCAL (label)) | |
1152 | bsi_next (&i); | |
1153 | else | |
1154 | bsi_remove (&i); | |
1155 | } | |
1156 | } | |
1157 | ||
1158 | free (label_for_bb); | |
1159 | } | |
1160 | ||
f667741c SB |
1161 | /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE), |
1162 | and scan the sorted vector of cases. Combine the ones jumping to the | |
1163 | same label. | |
1164 | Eg. three separate entries 1: 2: 3: become one entry 1..3: */ | |
1165 | ||
165b54c3 | 1166 | void |
f667741c SB |
1167 | group_case_labels (void) |
1168 | { | |
1169 | basic_block bb; | |
1170 | ||
1171 | FOR_EACH_BB (bb) | |
1172 | { | |
1173 | tree stmt = last_stmt (bb); | |
1174 | if (stmt && TREE_CODE (stmt) == SWITCH_EXPR) | |
1175 | { | |
1176 | tree labels = SWITCH_LABELS (stmt); | |
1177 | int old_size = TREE_VEC_LENGTH (labels); | |
1178 | int i, j, new_size = old_size; | |
29c4d22b AP |
1179 | tree default_case = TREE_VEC_ELT (labels, old_size - 1); |
1180 | tree default_label; | |
1181 | ||
66efeafc | 1182 | /* The default label is always the last case in a switch |
29c4d22b AP |
1183 | statement after gimplification. */ |
1184 | default_label = CASE_LABEL (default_case); | |
f667741c SB |
1185 | |
1186 | /* Look for possible opportunities to merge cases. | |
1187 | Ignore the last element of the label vector because it | |
1188 | must be the default case. */ | |
1189 | i = 0; | |
d717e500 | 1190 | while (i < old_size - 1) |
f667741c | 1191 | { |
ed9cef22 | 1192 | tree base_case, base_label, base_high; |
f667741c SB |
1193 | base_case = TREE_VEC_ELT (labels, i); |
1194 | ||
1e128c5f | 1195 | gcc_assert (base_case); |
f667741c | 1196 | base_label = CASE_LABEL (base_case); |
31e9eea2 SB |
1197 | |
1198 | /* Discard cases that have the same destination as the | |
1199 | default case. */ | |
1200 | if (base_label == default_label) | |
1201 | { | |
1202 | TREE_VEC_ELT (labels, i) = NULL_TREE; | |
1203 | i++; | |
29c4d22b | 1204 | new_size--; |
31e9eea2 SB |
1205 | continue; |
1206 | } | |
1207 | ||
f667741c SB |
1208 | base_high = CASE_HIGH (base_case) ? |
1209 | CASE_HIGH (base_case) : CASE_LOW (base_case); | |
d717e500 | 1210 | i++; |
f667741c SB |
1211 | /* Try to merge case labels. Break out when we reach the end |
1212 | of the label vector or when we cannot merge the next case | |
1213 | label with the current one. */ | |
d717e500 | 1214 | while (i < old_size - 1) |
f667741c | 1215 | { |
d717e500 | 1216 | tree merge_case = TREE_VEC_ELT (labels, i); |
f667741c SB |
1217 | tree merge_label = CASE_LABEL (merge_case); |
1218 | tree t = int_const_binop (PLUS_EXPR, base_high, | |
1219 | integer_one_node, 1); | |
1220 | ||
1221 | /* Merge the cases if they jump to the same place, | |
1222 | and their ranges are consecutive. */ | |
1223 | if (merge_label == base_label | |
1224 | && tree_int_cst_equal (CASE_LOW (merge_case), t)) | |
1225 | { | |
1226 | base_high = CASE_HIGH (merge_case) ? | |
1227 | CASE_HIGH (merge_case) : CASE_LOW (merge_case); | |
1228 | CASE_HIGH (base_case) = base_high; | |
1229 | TREE_VEC_ELT (labels, i) = NULL_TREE; | |
1230 | new_size--; | |
d717e500 | 1231 | i++; |
f667741c SB |
1232 | } |
1233 | else | |
1234 | break; | |
1235 | } | |
1236 | } | |
1237 | ||
1238 | /* Compress the case labels in the label vector, and adjust the | |
1239 | length of the vector. */ | |
1240 | for (i = 0, j = 0; i < new_size; i++) | |
1241 | { | |
1242 | while (! TREE_VEC_ELT (labels, j)) | |
1243 | j++; | |
1244 | TREE_VEC_ELT (labels, i) = TREE_VEC_ELT (labels, j++); | |
1245 | } | |
1246 | TREE_VEC_LENGTH (labels) = new_size; | |
1247 | } | |
1248 | } | |
1249 | } | |
6de9cd9a DN |
1250 | |
1251 | /* Checks whether we can merge block B into block A. */ | |
1252 | ||
1253 | static bool | |
1254 | tree_can_merge_blocks_p (basic_block a, basic_block b) | |
1255 | { | |
1256 | tree stmt; | |
1257 | block_stmt_iterator bsi; | |
1258 | ||
c5cbcccf | 1259 | if (!single_succ_p (a)) |
6de9cd9a DN |
1260 | return false; |
1261 | ||
c5cbcccf | 1262 | if (single_succ_edge (a)->flags & EDGE_ABNORMAL) |
6de9cd9a DN |
1263 | return false; |
1264 | ||
c5cbcccf | 1265 | if (single_succ (a) != b) |
6de9cd9a DN |
1266 | return false; |
1267 | ||
c5cbcccf | 1268 | if (!single_pred_p (b)) |
6de9cd9a DN |
1269 | return false; |
1270 | ||
26e75214 KH |
1271 | if (b == EXIT_BLOCK_PTR) |
1272 | return false; | |
1273 | ||
6de9cd9a DN |
1274 | /* If A ends by a statement causing exceptions or something similar, we |
1275 | cannot merge the blocks. */ | |
1276 | stmt = last_stmt (a); | |
1277 | if (stmt && stmt_ends_bb_p (stmt)) | |
1278 | return false; | |
1279 | ||
1280 | /* Do not allow a block with only a non-local label to be merged. */ | |
1281 | if (stmt && TREE_CODE (stmt) == LABEL_EXPR | |
1282 | && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))) | |
1283 | return false; | |
1284 | ||
1285 | /* There may be no phi nodes at the start of b. Most of these degenerate | |
1286 | phi nodes should be cleaned up by kill_redundant_phi_nodes. */ | |
1287 | if (phi_nodes (b)) | |
1288 | return false; | |
1289 | ||
1290 | /* Do not remove user labels. */ | |
1291 | for (bsi = bsi_start (b); !bsi_end_p (bsi); bsi_next (&bsi)) | |
1292 | { | |
1293 | stmt = bsi_stmt (bsi); | |
1294 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
1295 | break; | |
1296 | if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt))) | |
1297 | return false; | |
1298 | } | |
1299 | ||
2b271002 ZD |
1300 | /* Protect the loop latches. */ |
1301 | if (current_loops | |
1302 | && b->loop_father->latch == b) | |
1303 | return false; | |
1304 | ||
6de9cd9a DN |
1305 | return true; |
1306 | } | |
1307 | ||
1308 | ||
1309 | /* Merge block B into block A. */ | |
1310 | ||
1311 | static void | |
1312 | tree_merge_blocks (basic_block a, basic_block b) | |
1313 | { | |
1314 | block_stmt_iterator bsi; | |
1315 | tree_stmt_iterator last; | |
1316 | ||
1317 | if (dump_file) | |
1318 | fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index); | |
1319 | ||
1320 | /* Ensure that B follows A. */ | |
1321 | move_block_after (b, a); | |
1322 | ||
c5cbcccf | 1323 | gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU); |
1e128c5f | 1324 | gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a))); |
6de9cd9a DN |
1325 | |
1326 | /* Remove labels from B and set bb_for_stmt to A for other statements. */ | |
1327 | for (bsi = bsi_start (b); !bsi_end_p (bsi);) | |
1328 | { | |
1329 | if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR) | |
be477406 JL |
1330 | { |
1331 | tree label = bsi_stmt (bsi); | |
1332 | ||
1333 | bsi_remove (&bsi); | |
1334 | /* Now that we can thread computed gotos, we might have | |
1335 | a situation where we have a forced label in block B | |
1336 | However, the label at the start of block B might still be | |
1337 | used in other ways (think about the runtime checking for | |
1338 | Fortran assigned gotos). So we can not just delete the | |
1339 | label. Instead we move the label to the start of block A. */ | |
1340 | if (FORCED_LABEL (LABEL_EXPR_LABEL (label))) | |
1341 | { | |
1342 | block_stmt_iterator dest_bsi = bsi_start (a); | |
1343 | bsi_insert_before (&dest_bsi, label, BSI_NEW_STMT); | |
1344 | } | |
1345 | } | |
6de9cd9a DN |
1346 | else |
1347 | { | |
1348 | set_bb_for_stmt (bsi_stmt (bsi), a); | |
1349 | bsi_next (&bsi); | |
1350 | } | |
1351 | } | |
1352 | ||
1353 | /* Merge the chains. */ | |
1354 | last = tsi_last (a->stmt_list); | |
1355 | tsi_link_after (&last, b->stmt_list, TSI_NEW_STMT); | |
1356 | b->stmt_list = NULL; | |
1357 | } | |
1358 | ||
1359 | ||
1360 | /* Walk the function tree removing unnecessary statements. | |
1361 | ||
1362 | * Empty statement nodes are removed | |
1363 | ||
1364 | * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed | |
1365 | ||
1366 | * Unnecessary COND_EXPRs are removed | |
1367 | ||
1368 | * Some unnecessary BIND_EXPRs are removed | |
1369 | ||
1370 | Clearly more work could be done. The trick is doing the analysis | |
1371 | and removal fast enough to be a net improvement in compile times. | |
1372 | ||
1373 | Note that when we remove a control structure such as a COND_EXPR | |
1374 | BIND_EXPR, or TRY block, we will need to repeat this optimization pass | |
1375 | to ensure we eliminate all the useless code. */ | |
1376 | ||
1377 | struct rus_data | |
1378 | { | |
1379 | tree *last_goto; | |
1380 | bool repeat; | |
1381 | bool may_throw; | |
1382 | bool may_branch; | |
1383 | bool has_label; | |
1384 | }; | |
1385 | ||
1386 | static void remove_useless_stmts_1 (tree *, struct rus_data *); | |
1387 | ||
1388 | static bool | |
1389 | remove_useless_stmts_warn_notreached (tree stmt) | |
1390 | { | |
9506ac2b | 1391 | if (EXPR_HAS_LOCATION (stmt)) |
6de9cd9a | 1392 | { |
9506ac2b | 1393 | location_t loc = EXPR_LOCATION (stmt); |
43e05e45 SB |
1394 | if (LOCATION_LINE (loc) > 0) |
1395 | { | |
1396 | warning ("%Hwill never be executed", &loc); | |
1397 | return true; | |
1398 | } | |
6de9cd9a DN |
1399 | } |
1400 | ||
1401 | switch (TREE_CODE (stmt)) | |
1402 | { | |
1403 | case STATEMENT_LIST: | |
1404 | { | |
1405 | tree_stmt_iterator i; | |
1406 | for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i)) | |
1407 | if (remove_useless_stmts_warn_notreached (tsi_stmt (i))) | |
1408 | return true; | |
1409 | } | |
1410 | break; | |
1411 | ||
1412 | case COND_EXPR: | |
1413 | if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt))) | |
1414 | return true; | |
1415 | if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt))) | |
1416 | return true; | |
1417 | if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt))) | |
1418 | return true; | |
1419 | break; | |
1420 | ||
1421 | case TRY_FINALLY_EXPR: | |
1422 | case TRY_CATCH_EXPR: | |
1423 | if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 0))) | |
1424 | return true; | |
1425 | if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 1))) | |
1426 | return true; | |
1427 | break; | |
1428 | ||
1429 | case CATCH_EXPR: | |
1430 | return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt)); | |
1431 | case EH_FILTER_EXPR: | |
1432 | return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt)); | |
1433 | case BIND_EXPR: | |
1434 | return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt)); | |
1435 | ||
1436 | default: | |
1437 | /* Not a live container. */ | |
1438 | break; | |
1439 | } | |
1440 | ||
1441 | return false; | |
1442 | } | |
1443 | ||
1444 | static void | |
1445 | remove_useless_stmts_cond (tree *stmt_p, struct rus_data *data) | |
1446 | { | |
1447 | tree then_clause, else_clause, cond; | |
1448 | bool save_has_label, then_has_label, else_has_label; | |
1449 | ||
1450 | save_has_label = data->has_label; | |
1451 | data->has_label = false; | |
1452 | data->last_goto = NULL; | |
1453 | ||
1454 | remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p), data); | |
1455 | ||
1456 | then_has_label = data->has_label; | |
1457 | data->has_label = false; | |
1458 | data->last_goto = NULL; | |
1459 | ||
1460 | remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p), data); | |
1461 | ||
1462 | else_has_label = data->has_label; | |
1463 | data->has_label = save_has_label | then_has_label | else_has_label; | |
1464 | ||
6de9cd9a DN |
1465 | then_clause = COND_EXPR_THEN (*stmt_p); |
1466 | else_clause = COND_EXPR_ELSE (*stmt_p); | |
18faa5da | 1467 | cond = fold (COND_EXPR_COND (*stmt_p)); |
6de9cd9a DN |
1468 | |
1469 | /* If neither arm does anything at all, we can remove the whole IF. */ | |
1470 | if (!TREE_SIDE_EFFECTS (then_clause) && !TREE_SIDE_EFFECTS (else_clause)) | |
1471 | { | |
1472 | *stmt_p = build_empty_stmt (); | |
1473 | data->repeat = true; | |
1474 | } | |
1475 | ||
1476 | /* If there are no reachable statements in an arm, then we can | |
1477 | zap the entire conditional. */ | |
1478 | else if (integer_nonzerop (cond) && !else_has_label) | |
1479 | { | |
1480 | if (warn_notreached) | |
1481 | remove_useless_stmts_warn_notreached (else_clause); | |
1482 | *stmt_p = then_clause; | |
1483 | data->repeat = true; | |
1484 | } | |
1485 | else if (integer_zerop (cond) && !then_has_label) | |
1486 | { | |
1487 | if (warn_notreached) | |
1488 | remove_useless_stmts_warn_notreached (then_clause); | |
1489 | *stmt_p = else_clause; | |
1490 | data->repeat = true; | |
1491 | } | |
1492 | ||
1493 | /* Check a couple of simple things on then/else with single stmts. */ | |
1494 | else | |
1495 | { | |
1496 | tree then_stmt = expr_only (then_clause); | |
1497 | tree else_stmt = expr_only (else_clause); | |
1498 | ||
1499 | /* Notice branches to a common destination. */ | |
1500 | if (then_stmt && else_stmt | |
1501 | && TREE_CODE (then_stmt) == GOTO_EXPR | |
1502 | && TREE_CODE (else_stmt) == GOTO_EXPR | |
1503 | && (GOTO_DESTINATION (then_stmt) == GOTO_DESTINATION (else_stmt))) | |
1504 | { | |
1505 | *stmt_p = then_stmt; | |
1506 | data->repeat = true; | |
1507 | } | |
1508 | ||
1509 | /* If the THEN/ELSE clause merely assigns a value to a variable or | |
1510 | parameter which is already known to contain that value, then | |
1511 | remove the useless THEN/ELSE clause. */ | |
1512 | else if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL) | |
1513 | { | |
1514 | if (else_stmt | |
1515 | && TREE_CODE (else_stmt) == MODIFY_EXPR | |
1516 | && TREE_OPERAND (else_stmt, 0) == cond | |
1517 | && integer_zerop (TREE_OPERAND (else_stmt, 1))) | |
1518 | COND_EXPR_ELSE (*stmt_p) = alloc_stmt_list (); | |
1519 | } | |
1520 | else if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR) | |
1521 | && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL | |
1522 | || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL) | |
1523 | && TREE_CONSTANT (TREE_OPERAND (cond, 1))) | |
1524 | { | |
1525 | tree stmt = (TREE_CODE (cond) == EQ_EXPR | |
1526 | ? then_stmt : else_stmt); | |
1527 | tree *location = (TREE_CODE (cond) == EQ_EXPR | |
1528 | ? &COND_EXPR_THEN (*stmt_p) | |
1529 | : &COND_EXPR_ELSE (*stmt_p)); | |
1530 | ||
1531 | if (stmt | |
1532 | && TREE_CODE (stmt) == MODIFY_EXPR | |
1533 | && TREE_OPERAND (stmt, 0) == TREE_OPERAND (cond, 0) | |
1534 | && TREE_OPERAND (stmt, 1) == TREE_OPERAND (cond, 1)) | |
1535 | *location = alloc_stmt_list (); | |
1536 | } | |
1537 | } | |
1538 | ||
1539 | /* Protect GOTOs in the arm of COND_EXPRs from being removed. They | |
1540 | would be re-introduced during lowering. */ | |
1541 | data->last_goto = NULL; | |
1542 | } | |
1543 | ||
1544 | ||
1545 | static void | |
1546 | remove_useless_stmts_tf (tree *stmt_p, struct rus_data *data) | |
1547 | { | |
1548 | bool save_may_branch, save_may_throw; | |
1549 | bool this_may_branch, this_may_throw; | |
1550 | ||
1551 | /* Collect may_branch and may_throw information for the body only. */ | |
1552 | save_may_branch = data->may_branch; | |
1553 | save_may_throw = data->may_throw; | |
1554 | data->may_branch = false; | |
1555 | data->may_throw = false; | |
1556 | data->last_goto = NULL; | |
1557 | ||
1558 | remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data); | |
1559 | ||
1560 | this_may_branch = data->may_branch; | |
1561 | this_may_throw = data->may_throw; | |
1562 | data->may_branch |= save_may_branch; | |
1563 | data->may_throw |= save_may_throw; | |
1564 | data->last_goto = NULL; | |
1565 | ||
1566 | remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data); | |
1567 | ||
1568 | /* If the body is empty, then we can emit the FINALLY block without | |
1569 | the enclosing TRY_FINALLY_EXPR. */ | |
1570 | if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 0))) | |
1571 | { | |
1572 | *stmt_p = TREE_OPERAND (*stmt_p, 1); | |
1573 | data->repeat = true; | |
1574 | } | |
1575 | ||
1576 | /* If the handler is empty, then we can emit the TRY block without | |
1577 | the enclosing TRY_FINALLY_EXPR. */ | |
1578 | else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1))) | |
1579 | { | |
1580 | *stmt_p = TREE_OPERAND (*stmt_p, 0); | |
1581 | data->repeat = true; | |
1582 | } | |
1583 | ||
1584 | /* If the body neither throws, nor branches, then we can safely | |
1585 | string the TRY and FINALLY blocks together. */ | |
1586 | else if (!this_may_branch && !this_may_throw) | |
1587 | { | |
1588 | tree stmt = *stmt_p; | |
1589 | *stmt_p = TREE_OPERAND (stmt, 0); | |
1590 | append_to_statement_list (TREE_OPERAND (stmt, 1), stmt_p); | |
1591 | data->repeat = true; | |
1592 | } | |
1593 | } | |
1594 | ||
1595 | ||
1596 | static void | |
1597 | remove_useless_stmts_tc (tree *stmt_p, struct rus_data *data) | |
1598 | { | |
1599 | bool save_may_throw, this_may_throw; | |
1600 | tree_stmt_iterator i; | |
1601 | tree stmt; | |
1602 | ||
1603 | /* Collect may_throw information for the body only. */ | |
1604 | save_may_throw = data->may_throw; | |
1605 | data->may_throw = false; | |
1606 | data->last_goto = NULL; | |
1607 | ||
1608 | remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data); | |
1609 | ||
1610 | this_may_throw = data->may_throw; | |
1611 | data->may_throw = save_may_throw; | |
1612 | ||
1613 | /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */ | |
1614 | if (!this_may_throw) | |
1615 | { | |
1616 | if (warn_notreached) | |
1617 | remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p, 1)); | |
1618 | *stmt_p = TREE_OPERAND (*stmt_p, 0); | |
1619 | data->repeat = true; | |
1620 | return; | |
1621 | } | |
1622 | ||
1623 | /* Process the catch clause specially. We may be able to tell that | |
1624 | no exceptions propagate past this point. */ | |
1625 | ||
1626 | this_may_throw = true; | |
1627 | i = tsi_start (TREE_OPERAND (*stmt_p, 1)); | |
1628 | stmt = tsi_stmt (i); | |
1629 | data->last_goto = NULL; | |
1630 | ||
1631 | switch (TREE_CODE (stmt)) | |
1632 | { | |
1633 | case CATCH_EXPR: | |
1634 | for (; !tsi_end_p (i); tsi_next (&i)) | |
1635 | { | |
1636 | stmt = tsi_stmt (i); | |
1637 | /* If we catch all exceptions, then the body does not | |
1638 | propagate exceptions past this point. */ | |
1639 | if (CATCH_TYPES (stmt) == NULL) | |
1640 | this_may_throw = false; | |
1641 | data->last_goto = NULL; | |
1642 | remove_useless_stmts_1 (&CATCH_BODY (stmt), data); | |
1643 | } | |
1644 | break; | |
1645 | ||
1646 | case EH_FILTER_EXPR: | |
1647 | if (EH_FILTER_MUST_NOT_THROW (stmt)) | |
1648 | this_may_throw = false; | |
1649 | else if (EH_FILTER_TYPES (stmt) == NULL) | |
1650 | this_may_throw = false; | |
1651 | remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt), data); | |
1652 | break; | |
1653 | ||
1654 | default: | |
1655 | /* Otherwise this is a cleanup. */ | |
1656 | remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data); | |
1657 | ||
1658 | /* If the cleanup is empty, then we can emit the TRY block without | |
1659 | the enclosing TRY_CATCH_EXPR. */ | |
1660 | if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1))) | |
1661 | { | |
1662 | *stmt_p = TREE_OPERAND (*stmt_p, 0); | |
1663 | data->repeat = true; | |
1664 | } | |
1665 | break; | |
1666 | } | |
1667 | data->may_throw |= this_may_throw; | |
1668 | } | |
1669 | ||
1670 | ||
1671 | static void | |
1672 | remove_useless_stmts_bind (tree *stmt_p, struct rus_data *data) | |
1673 | { | |
1674 | tree block; | |
1675 | ||
1676 | /* First remove anything underneath the BIND_EXPR. */ | |
1677 | remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p), data); | |
1678 | ||
1679 | /* If the BIND_EXPR has no variables, then we can pull everything | |
1680 | up one level and remove the BIND_EXPR, unless this is the toplevel | |
1681 | BIND_EXPR for the current function or an inlined function. | |
1682 | ||
1683 | When this situation occurs we will want to apply this | |
1684 | optimization again. */ | |
1685 | block = BIND_EXPR_BLOCK (*stmt_p); | |
1686 | if (BIND_EXPR_VARS (*stmt_p) == NULL_TREE | |
1687 | && *stmt_p != DECL_SAVED_TREE (current_function_decl) | |
1688 | && (! block | |
1689 | || ! BLOCK_ABSTRACT_ORIGIN (block) | |
1690 | || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block)) | |
1691 | != FUNCTION_DECL))) | |
1692 | { | |
1693 | *stmt_p = BIND_EXPR_BODY (*stmt_p); | |
1694 | data->repeat = true; | |
1695 | } | |
1696 | } | |
1697 | ||
1698 | ||
1699 | static void | |
1700 | remove_useless_stmts_goto (tree *stmt_p, struct rus_data *data) | |
1701 | { | |
1702 | tree dest = GOTO_DESTINATION (*stmt_p); | |
1703 | ||
1704 | data->may_branch = true; | |
1705 | data->last_goto = NULL; | |
1706 | ||
1707 | /* Record the last goto expr, so that we can delete it if unnecessary. */ | |
1708 | if (TREE_CODE (dest) == LABEL_DECL) | |
1709 | data->last_goto = stmt_p; | |
1710 | } | |
1711 | ||
1712 | ||
1713 | static void | |
1714 | remove_useless_stmts_label (tree *stmt_p, struct rus_data *data) | |
1715 | { | |
1716 | tree label = LABEL_EXPR_LABEL (*stmt_p); | |
1717 | ||
1718 | data->has_label = true; | |
1719 | ||
1720 | /* We do want to jump across non-local label receiver code. */ | |
1721 | if (DECL_NONLOCAL (label)) | |
1722 | data->last_goto = NULL; | |
1723 | ||
1724 | else if (data->last_goto && GOTO_DESTINATION (*data->last_goto) == label) | |
1725 | { | |
1726 | *data->last_goto = build_empty_stmt (); | |
1727 | data->repeat = true; | |
1728 | } | |
1729 | ||
1730 | /* ??? Add something here to delete unused labels. */ | |
1731 | } | |
1732 | ||
1733 | ||
1734 | /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its | |
1735 | decl. This allows us to eliminate redundant or useless | |
1736 | calls to "const" functions. | |
1737 | ||
1738 | Gimplifier already does the same operation, but we may notice functions | |
1739 | being const and pure once their calls has been gimplified, so we need | |
1740 | to update the flag. */ | |
1741 | ||
1742 | static void | |
1743 | update_call_expr_flags (tree call) | |
1744 | { | |
1745 | tree decl = get_callee_fndecl (call); | |
1746 | if (!decl) | |
1747 | return; | |
1748 | if (call_expr_flags (call) & (ECF_CONST | ECF_PURE)) | |
1749 | TREE_SIDE_EFFECTS (call) = 0; | |
1750 | if (TREE_NOTHROW (decl)) | |
1751 | TREE_NOTHROW (call) = 1; | |
1752 | } | |
1753 | ||
1754 | ||
1755 | /* T is CALL_EXPR. Set current_function_calls_* flags. */ | |
1756 | ||
1757 | void | |
1758 | notice_special_calls (tree t) | |
1759 | { | |
1760 | int flags = call_expr_flags (t); | |
1761 | ||
1762 | if (flags & ECF_MAY_BE_ALLOCA) | |
1763 | current_function_calls_alloca = true; | |
1764 | if (flags & ECF_RETURNS_TWICE) | |
1765 | current_function_calls_setjmp = true; | |
1766 | } | |
1767 | ||
1768 | ||
1769 | /* Clear flags set by notice_special_calls. Used by dead code removal | |
1770 | to update the flags. */ | |
1771 | ||
1772 | void | |
1773 | clear_special_calls (void) | |
1774 | { | |
1775 | current_function_calls_alloca = false; | |
1776 | current_function_calls_setjmp = false; | |
1777 | } | |
1778 | ||
1779 | ||
1780 | static void | |
1781 | remove_useless_stmts_1 (tree *tp, struct rus_data *data) | |
1782 | { | |
cd709752 | 1783 | tree t = *tp, op; |
6de9cd9a DN |
1784 | |
1785 | switch (TREE_CODE (t)) | |
1786 | { | |
1787 | case COND_EXPR: | |
1788 | remove_useless_stmts_cond (tp, data); | |
1789 | break; | |
1790 | ||
1791 | case TRY_FINALLY_EXPR: | |
1792 | remove_useless_stmts_tf (tp, data); | |
1793 | break; | |
1794 | ||
1795 | case TRY_CATCH_EXPR: | |
1796 | remove_useless_stmts_tc (tp, data); | |
1797 | break; | |
1798 | ||
1799 | case BIND_EXPR: | |
1800 | remove_useless_stmts_bind (tp, data); | |
1801 | break; | |
1802 | ||
1803 | case GOTO_EXPR: | |
1804 | remove_useless_stmts_goto (tp, data); | |
1805 | break; | |
1806 | ||
1807 | case LABEL_EXPR: | |
1808 | remove_useless_stmts_label (tp, data); | |
1809 | break; | |
1810 | ||
1811 | case RETURN_EXPR: | |
53e782e5 | 1812 | fold_stmt (tp); |
6de9cd9a DN |
1813 | data->last_goto = NULL; |
1814 | data->may_branch = true; | |
1815 | break; | |
1816 | ||
1817 | case CALL_EXPR: | |
53e782e5 | 1818 | fold_stmt (tp); |
6de9cd9a DN |
1819 | data->last_goto = NULL; |
1820 | notice_special_calls (t); | |
1821 | update_call_expr_flags (t); | |
1822 | if (tree_could_throw_p (t)) | |
1823 | data->may_throw = true; | |
1824 | break; | |
1825 | ||
1826 | case MODIFY_EXPR: | |
1827 | data->last_goto = NULL; | |
53e782e5 | 1828 | fold_stmt (tp); |
cd709752 RH |
1829 | op = get_call_expr_in (t); |
1830 | if (op) | |
6de9cd9a | 1831 | { |
cd709752 RH |
1832 | update_call_expr_flags (op); |
1833 | notice_special_calls (op); | |
6de9cd9a DN |
1834 | } |
1835 | if (tree_could_throw_p (t)) | |
1836 | data->may_throw = true; | |
1837 | break; | |
1838 | ||
1839 | case STATEMENT_LIST: | |
1840 | { | |
1841 | tree_stmt_iterator i = tsi_start (t); | |
1842 | while (!tsi_end_p (i)) | |
1843 | { | |
1844 | t = tsi_stmt (i); | |
1845 | if (IS_EMPTY_STMT (t)) | |
1846 | { | |
1847 | tsi_delink (&i); | |
1848 | continue; | |
1849 | } | |
1850 | ||
1851 | remove_useless_stmts_1 (tsi_stmt_ptr (i), data); | |
1852 | ||
1853 | t = tsi_stmt (i); | |
1854 | if (TREE_CODE (t) == STATEMENT_LIST) | |
1855 | { | |
1856 | tsi_link_before (&i, t, TSI_SAME_STMT); | |
1857 | tsi_delink (&i); | |
1858 | } | |
1859 | else | |
1860 | tsi_next (&i); | |
1861 | } | |
1862 | } | |
1863 | break; | |
8e14584d | 1864 | case ASM_EXPR: |
53e782e5 AP |
1865 | fold_stmt (tp); |
1866 | data->last_goto = NULL; | |
1867 | break; | |
6de9cd9a DN |
1868 | |
1869 | default: | |
1870 | data->last_goto = NULL; | |
1871 | break; | |
1872 | } | |
1873 | } | |
1874 | ||
1875 | static void | |
1876 | remove_useless_stmts (void) | |
1877 | { | |
1878 | struct rus_data data; | |
1879 | ||
1880 | clear_special_calls (); | |
1881 | ||
1882 | do | |
1883 | { | |
1884 | memset (&data, 0, sizeof (data)); | |
1885 | remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl), &data); | |
1886 | } | |
1887 | while (data.repeat); | |
1888 | } | |
1889 | ||
1890 | ||
1891 | struct tree_opt_pass pass_remove_useless_stmts = | |
1892 | { | |
1893 | "useless", /* name */ | |
1894 | NULL, /* gate */ | |
1895 | remove_useless_stmts, /* execute */ | |
1896 | NULL, /* sub */ | |
1897 | NULL, /* next */ | |
1898 | 0, /* static_pass_number */ | |
1899 | 0, /* tv_id */ | |
1900 | PROP_gimple_any, /* properties_required */ | |
1901 | 0, /* properties_provided */ | |
1902 | 0, /* properties_destroyed */ | |
1903 | 0, /* todo_flags_start */ | |
9f8628ba PB |
1904 | TODO_dump_func, /* todo_flags_finish */ |
1905 | 0 /* letter */ | |
6de9cd9a DN |
1906 | }; |
1907 | ||
1908 | ||
1909 | /* Remove obviously useless statements in basic block BB. */ | |
1910 | ||
1911 | static void | |
1912 | cfg_remove_useless_stmts_bb (basic_block bb) | |
1913 | { | |
1914 | block_stmt_iterator bsi; | |
1915 | tree stmt = NULL_TREE; | |
1916 | tree cond, var = NULL_TREE, val = NULL_TREE; | |
1917 | struct var_ann_d *ann; | |
1918 | ||
1919 | /* Check whether we come here from a condition, and if so, get the | |
1920 | condition. */ | |
c5cbcccf ZD |
1921 | if (!single_pred_p (bb) |
1922 | || !(single_pred_edge (bb)->flags | |
1923 | & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))) | |
6de9cd9a DN |
1924 | return; |
1925 | ||
c5cbcccf | 1926 | cond = COND_EXPR_COND (last_stmt (single_pred (bb))); |
6de9cd9a DN |
1927 | |
1928 | if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL) | |
1929 | { | |
1930 | var = cond; | |
c5cbcccf | 1931 | val = (single_pred_edge (bb)->flags & EDGE_FALSE_VALUE |
6de9cd9a DN |
1932 | ? boolean_false_node : boolean_true_node); |
1933 | } | |
1934 | else if (TREE_CODE (cond) == TRUTH_NOT_EXPR | |
1935 | && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL | |
1936 | || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL)) | |
1937 | { | |
1938 | var = TREE_OPERAND (cond, 0); | |
c5cbcccf | 1939 | val = (single_pred_edge (bb)->flags & EDGE_FALSE_VALUE |
6de9cd9a DN |
1940 | ? boolean_true_node : boolean_false_node); |
1941 | } | |
1942 | else | |
1943 | { | |
c5cbcccf | 1944 | if (single_pred_edge (bb)->flags & EDGE_FALSE_VALUE) |
6de9cd9a DN |
1945 | cond = invert_truthvalue (cond); |
1946 | if (TREE_CODE (cond) == EQ_EXPR | |
1947 | && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL | |
1948 | || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL) | |
1949 | && (TREE_CODE (TREE_OPERAND (cond, 1)) == VAR_DECL | |
1950 | || TREE_CODE (TREE_OPERAND (cond, 1)) == PARM_DECL | |
1951 | || TREE_CONSTANT (TREE_OPERAND (cond, 1)))) | |
1952 | { | |
1953 | var = TREE_OPERAND (cond, 0); | |
1954 | val = TREE_OPERAND (cond, 1); | |
1955 | } | |
1956 | else | |
1957 | return; | |
1958 | } | |
1959 | ||
1960 | /* Only work for normal local variables. */ | |
1961 | ann = var_ann (var); | |
1962 | if (!ann | |
1963 | || ann->may_aliases | |
1964 | || TREE_ADDRESSABLE (var)) | |
1965 | return; | |
1966 | ||
1967 | if (! TREE_CONSTANT (val)) | |
1968 | { | |
1969 | ann = var_ann (val); | |
1970 | if (!ann | |
1971 | || ann->may_aliases | |
1972 | || TREE_ADDRESSABLE (val)) | |
1973 | return; | |
1974 | } | |
1975 | ||
1976 | /* Ignore floating point variables, since comparison behaves weird for | |
1977 | them. */ | |
1978 | if (FLOAT_TYPE_P (TREE_TYPE (var))) | |
1979 | return; | |
1980 | ||
1981 | for (bsi = bsi_start (bb); !bsi_end_p (bsi);) | |
1982 | { | |
1983 | stmt = bsi_stmt (bsi); | |
1984 | ||
1985 | /* If the THEN/ELSE clause merely assigns a value to a variable/parameter | |
1986 | which is already known to contain that value, then remove the useless | |
1987 | THEN/ELSE clause. */ | |
1988 | if (TREE_CODE (stmt) == MODIFY_EXPR | |
1989 | && TREE_OPERAND (stmt, 0) == var | |
1990 | && operand_equal_p (val, TREE_OPERAND (stmt, 1), 0)) | |
1991 | { | |
1992 | bsi_remove (&bsi); | |
1993 | continue; | |
1994 | } | |
1995 | ||
631b67ce RK |
1996 | /* Invalidate the var if we encounter something that could modify it. |
1997 | Likewise for the value it was previously set to. Note that we only | |
1998 | consider values that are either a VAR_DECL or PARM_DECL so we | |
1999 | can test for conflict very simply. */ | |
6de9cd9a | 2000 | if (TREE_CODE (stmt) == ASM_EXPR |
6de9cd9a | 2001 | || (TREE_CODE (stmt) == MODIFY_EXPR |
631b67ce RK |
2002 | && (TREE_OPERAND (stmt, 0) == var |
2003 | || TREE_OPERAND (stmt, 0) == val))) | |
6de9cd9a DN |
2004 | return; |
2005 | ||
2006 | bsi_next (&bsi); | |
2007 | } | |
2008 | } | |
2009 | ||
2010 | ||
2011 | /* A CFG-aware version of remove_useless_stmts. */ | |
2012 | ||
2013 | void | |
2014 | cfg_remove_useless_stmts (void) | |
2015 | { | |
2016 | basic_block bb; | |
2017 | ||
2018 | #ifdef ENABLE_CHECKING | |
2019 | verify_flow_info (); | |
2020 | #endif | |
2021 | ||
2022 | FOR_EACH_BB (bb) | |
2023 | { | |
2024 | cfg_remove_useless_stmts_bb (bb); | |
2025 | } | |
2026 | } | |
2027 | ||
2028 | ||
2029 | /* Remove PHI nodes associated with basic block BB and all edges out of BB. */ | |
2030 | ||
2031 | static void | |
2032 | remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb) | |
2033 | { | |
2034 | tree phi; | |
2035 | ||
2036 | /* Since this block is no longer reachable, we can just delete all | |
2037 | of its PHI nodes. */ | |
2038 | phi = phi_nodes (bb); | |
2039 | while (phi) | |
2040 | { | |
17192884 | 2041 | tree next = PHI_CHAIN (phi); |
d19e3ef6 | 2042 | remove_phi_node (phi, NULL_TREE); |
6de9cd9a DN |
2043 | phi = next; |
2044 | } | |
2045 | ||
2046 | /* Remove edges to BB's successors. */ | |
628f6a4e | 2047 | while (EDGE_COUNT (bb->succs) > 0) |
d0d2cc21 | 2048 | remove_edge (EDGE_SUCC (bb, 0)); |
6de9cd9a DN |
2049 | } |
2050 | ||
2051 | ||
2052 | /* Remove statements of basic block BB. */ | |
2053 | ||
2054 | static void | |
2055 | remove_bb (basic_block bb) | |
2056 | { | |
2057 | block_stmt_iterator i; | |
dbce1570 PB |
2058 | #ifdef USE_MAPPED_LOCATION |
2059 | source_location loc = UNKNOWN_LOCATION; | |
2060 | #else | |
9506ac2b | 2061 | source_locus loc = 0; |
dbce1570 | 2062 | #endif |
6de9cd9a DN |
2063 | |
2064 | if (dump_file) | |
2065 | { | |
2066 | fprintf (dump_file, "Removing basic block %d\n", bb->index); | |
2067 | if (dump_flags & TDF_DETAILS) | |
2068 | { | |
2069 | dump_bb (bb, dump_file, 0); | |
2070 | fprintf (dump_file, "\n"); | |
2071 | } | |
2072 | } | |
2073 | ||
2b271002 ZD |
2074 | /* If we remove the header or the latch of a loop, mark the loop for |
2075 | removal by setting its header and latch to NULL. */ | |
2076 | if (current_loops) | |
2077 | { | |
2078 | struct loop *loop = bb->loop_father; | |
2079 | ||
2080 | if (loop->latch == bb | |
2081 | || loop->header == bb) | |
2082 | { | |
2083 | loop->latch = NULL; | |
2084 | loop->header = NULL; | |
2085 | } | |
2086 | } | |
2087 | ||
6de9cd9a | 2088 | /* Remove all the instructions in the block. */ |
77568960 | 2089 | for (i = bsi_start (bb); !bsi_end_p (i);) |
6de9cd9a DN |
2090 | { |
2091 | tree stmt = bsi_stmt (i); | |
77568960 AP |
2092 | if (TREE_CODE (stmt) == LABEL_EXPR |
2093 | && FORCED_LABEL (LABEL_EXPR_LABEL (stmt))) | |
2094 | { | |
2095 | basic_block new_bb = bb->prev_bb; | |
ef0b4f28 | 2096 | block_stmt_iterator new_bsi = bsi_start (new_bb); |
77568960 AP |
2097 | |
2098 | bsi_remove (&i); | |
ef0b4f28 | 2099 | bsi_insert_before (&new_bsi, stmt, BSI_NEW_STMT); |
77568960 AP |
2100 | } |
2101 | else | |
2102 | { | |
2103 | release_defs (stmt); | |
6de9cd9a | 2104 | |
77568960 AP |
2105 | set_bb_for_stmt (stmt, NULL); |
2106 | bsi_remove (&i); | |
2107 | } | |
6de9cd9a DN |
2108 | |
2109 | /* Don't warn for removed gotos. Gotos are often removed due to | |
2110 | jump threading, thus resulting in bogus warnings. Not great, | |
2111 | since this way we lose warnings for gotos in the original | |
2112 | program that are indeed unreachable. */ | |
9506ac2b | 2113 | if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc) |
43e05e45 | 2114 | { |
9506ac2b | 2115 | #ifdef USE_MAPPED_LOCATION |
dbce1570 PB |
2116 | if (EXPR_HAS_LOCATION (stmt)) |
2117 | loc = EXPR_LOCATION (stmt); | |
9506ac2b | 2118 | #else |
dbce1570 | 2119 | source_locus t; |
43e05e45 | 2120 | t = EXPR_LOCUS (stmt); |
43e05e45 SB |
2121 | if (t && LOCATION_LINE (*t) > 0) |
2122 | loc = t; | |
dbce1570 | 2123 | #endif |
43e05e45 | 2124 | } |
6de9cd9a DN |
2125 | } |
2126 | ||
2127 | /* If requested, give a warning that the first statement in the | |
2128 | block is unreachable. We walk statements backwards in the | |
2129 | loop above, so the last statement we process is the first statement | |
2130 | in the block. */ | |
9506ac2b | 2131 | #ifdef USE_MAPPED_LOCATION |
dbce1570 | 2132 | if (warn_notreached && loc != UNKNOWN_LOCATION) |
9506ac2b PB |
2133 | warning ("%Hwill never be executed", &loc); |
2134 | #else | |
dbce1570 | 2135 | if (warn_notreached && loc) |
6de9cd9a | 2136 | warning ("%Hwill never be executed", loc); |
9506ac2b | 2137 | #endif |
6de9cd9a DN |
2138 | |
2139 | remove_phi_nodes_and_edges_for_unreachable_block (bb); | |
2140 | } | |
2141 | ||
7ded35b4 RS |
2142 | /* A list of all the noreturn calls passed to modify_stmt. |
2143 | cleanup_control_flow uses it to detect cases where a mid-block | |
2144 | indirect call has been turned into a noreturn call. When this | |
2145 | happens, all the instructions after the call are no longer | |
2146 | reachable and must be deleted as dead. */ | |
2147 | ||
2148 | VEC(tree) *modified_noreturn_calls; | |
2149 | ||
6de9cd9a DN |
2150 | /* Try to remove superfluous control structures. */ |
2151 | ||
2152 | static bool | |
2153 | cleanup_control_flow (void) | |
2154 | { | |
2155 | basic_block bb; | |
2156 | block_stmt_iterator bsi; | |
2157 | bool retval = false; | |
7ded35b4 RS |
2158 | tree stmt; |
2159 | ||
2160 | /* Detect cases where a mid-block call is now known not to return. */ | |
2161 | while (VEC_length (tree, modified_noreturn_calls)) | |
2162 | { | |
2163 | stmt = VEC_pop (tree, modified_noreturn_calls); | |
2164 | bb = bb_for_stmt (stmt); | |
2165 | if (bb != NULL && last_stmt (bb) != stmt && noreturn_call_p (stmt)) | |
2166 | split_block (bb, stmt); | |
2167 | } | |
6de9cd9a DN |
2168 | |
2169 | FOR_EACH_BB (bb) | |
2170 | { | |
2171 | bsi = bsi_last (bb); | |
2172 | ||
2173 | if (bsi_end_p (bsi)) | |
2174 | continue; | |
2175 | ||
2176 | stmt = bsi_stmt (bsi); | |
2177 | if (TREE_CODE (stmt) == COND_EXPR | |
2178 | || TREE_CODE (stmt) == SWITCH_EXPR) | |
2179 | retval |= cleanup_control_expr_graph (bb, bsi); | |
d7f3fc19 | 2180 | |
be477406 JL |
2181 | /* If we had a computed goto which has a compile-time determinable |
2182 | destination, then we can eliminate the goto. */ | |
2183 | if (TREE_CODE (stmt) == GOTO_EXPR | |
2184 | && TREE_CODE (GOTO_DESTINATION (stmt)) == ADDR_EXPR | |
2185 | && TREE_CODE (TREE_OPERAND (GOTO_DESTINATION (stmt), 0)) == LABEL_DECL) | |
2186 | { | |
2187 | edge e; | |
2188 | tree label; | |
2189 | edge_iterator ei; | |
2190 | basic_block target_block; | |
b0c32a73 | 2191 | bool removed_edge = false; |
be477406 JL |
2192 | |
2193 | /* First look at all the outgoing edges. Delete any outgoing | |
2194 | edges which do not go to the right block. For the one | |
2195 | edge which goes to the right block, fix up its flags. */ | |
2196 | label = TREE_OPERAND (GOTO_DESTINATION (stmt), 0); | |
2197 | target_block = label_to_block (label); | |
2198 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) | |
2199 | { | |
2200 | if (e->dest != target_block) | |
b0c32a73 JL |
2201 | { |
2202 | removed_edge = true; | |
2203 | remove_edge (e); | |
2204 | } | |
be477406 JL |
2205 | else |
2206 | { | |
2207 | /* Turn off the EDGE_ABNORMAL flag. */ | |
c5cbcccf | 2208 | e->flags &= ~EDGE_ABNORMAL; |
be477406 JL |
2209 | |
2210 | /* And set EDGE_FALLTHRU. */ | |
c5cbcccf | 2211 | e->flags |= EDGE_FALLTHRU; |
be477406 JL |
2212 | ei_next (&ei); |
2213 | } | |
2214 | } | |
2215 | ||
b0c32a73 JL |
2216 | /* If we removed one or more edges, then we will need to fix the |
2217 | dominators. It may be possible to incrementally update them. */ | |
2218 | if (removed_edge) | |
2219 | free_dominance_info (CDI_DOMINATORS); | |
2220 | ||
be477406 JL |
2221 | /* Remove the GOTO_EXPR as it is not needed. The CFG has all the |
2222 | relevant information we need. */ | |
2223 | bsi_remove (&bsi); | |
2224 | retval = true; | |
2225 | } | |
2226 | ||
d7f3fc19 RS |
2227 | /* Check for indirect calls that have been turned into |
2228 | noreturn calls. */ | |
7ded35b4 | 2229 | if (noreturn_call_p (stmt) && remove_fallthru_edge (bb->succs)) |
d7f3fc19 RS |
2230 | { |
2231 | free_dominance_info (CDI_DOMINATORS); | |
2232 | retval = true; | |
2233 | } | |
6de9cd9a DN |
2234 | } |
2235 | return retval; | |
2236 | } | |
2237 | ||
2238 | ||
2239 | /* Disconnect an unreachable block in the control expression starting | |
2240 | at block BB. */ | |
2241 | ||
2242 | static bool | |
2243 | cleanup_control_expr_graph (basic_block bb, block_stmt_iterator bsi) | |
2244 | { | |
2245 | edge taken_edge; | |
2246 | bool retval = false; | |
2247 | tree expr = bsi_stmt (bsi), val; | |
2248 | ||
c5cbcccf | 2249 | if (!single_succ_p (bb)) |
6de9cd9a | 2250 | { |
628f6a4e BE |
2251 | edge e; |
2252 | edge_iterator ei; | |
6de9cd9a DN |
2253 | |
2254 | switch (TREE_CODE (expr)) | |
2255 | { | |
2256 | case COND_EXPR: | |
2257 | val = COND_EXPR_COND (expr); | |
2258 | break; | |
2259 | ||
2260 | case SWITCH_EXPR: | |
2261 | val = SWITCH_COND (expr); | |
2262 | if (TREE_CODE (val) != INTEGER_CST) | |
2263 | return false; | |
2264 | break; | |
2265 | ||
2266 | default: | |
1e128c5f | 2267 | gcc_unreachable (); |
6de9cd9a DN |
2268 | } |
2269 | ||
2270 | taken_edge = find_taken_edge (bb, val); | |
2271 | if (!taken_edge) | |
2272 | return false; | |
2273 | ||
2274 | /* Remove all the edges except the one that is always executed. */ | |
628f6a4e | 2275 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
6de9cd9a | 2276 | { |
6de9cd9a DN |
2277 | if (e != taken_edge) |
2278 | { | |
2279 | taken_edge->probability += e->probability; | |
2280 | taken_edge->count += e->count; | |
d0d2cc21 | 2281 | remove_edge (e); |
6de9cd9a DN |
2282 | retval = true; |
2283 | } | |
628f6a4e BE |
2284 | else |
2285 | ei_next (&ei); | |
6de9cd9a DN |
2286 | } |
2287 | if (taken_edge->probability > REG_BR_PROB_BASE) | |
2288 | taken_edge->probability = REG_BR_PROB_BASE; | |
2289 | } | |
2290 | else | |
c5cbcccf | 2291 | taken_edge = single_succ_edge (bb); |
6de9cd9a DN |
2292 | |
2293 | bsi_remove (&bsi); | |
2294 | taken_edge->flags = EDGE_FALLTHRU; | |
2295 | ||
2296 | /* We removed some paths from the cfg. */ | |
fce22de5 | 2297 | free_dominance_info (CDI_DOMINATORS); |
6de9cd9a DN |
2298 | |
2299 | return retval; | |
2300 | } | |
2301 | ||
d7f3fc19 RS |
2302 | /* Remove any fallthru edge from EV. Return true if an edge was removed. */ |
2303 | ||
2304 | static bool | |
2305 | remove_fallthru_edge (VEC(edge) *ev) | |
2306 | { | |
2307 | edge_iterator ei; | |
2308 | edge e; | |
2309 | ||
2310 | FOR_EACH_EDGE (e, ei, ev) | |
2311 | if ((e->flags & EDGE_FALLTHRU) != 0) | |
2312 | { | |
2313 | remove_edge (e); | |
2314 | return true; | |
2315 | } | |
2316 | return false; | |
2317 | } | |
6de9cd9a | 2318 | |
35920270 KH |
2319 | /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a |
2320 | predicate VAL, return the edge that will be taken out of the block. | |
2321 | If VAL does not match a unique edge, NULL is returned. */ | |
6de9cd9a DN |
2322 | |
2323 | edge | |
2324 | find_taken_edge (basic_block bb, tree val) | |
2325 | { | |
2326 | tree stmt; | |
2327 | ||
2328 | stmt = last_stmt (bb); | |
2329 | ||
1e128c5f GB |
2330 | gcc_assert (stmt); |
2331 | gcc_assert (is_ctrl_stmt (stmt)); | |
65f4323d | 2332 | gcc_assert (val); |
6de9cd9a | 2333 | |
be477406 | 2334 | if (! is_gimple_min_invariant (val)) |
6de9cd9a DN |
2335 | return NULL; |
2336 | ||
2337 | if (TREE_CODE (stmt) == COND_EXPR) | |
2338 | return find_taken_edge_cond_expr (bb, val); | |
2339 | ||
2340 | if (TREE_CODE (stmt) == SWITCH_EXPR) | |
2341 | return find_taken_edge_switch_expr (bb, val); | |
2342 | ||
be477406 JL |
2343 | if (computed_goto_p (stmt)) |
2344 | return find_taken_edge_computed_goto (bb, TREE_OPERAND( val, 0)); | |
2345 | ||
35920270 | 2346 | gcc_unreachable (); |
6de9cd9a DN |
2347 | } |
2348 | ||
be477406 JL |
2349 | /* Given a constant value VAL and the entry block BB to a GOTO_EXPR |
2350 | statement, determine which of the outgoing edges will be taken out of the | |
2351 | block. Return NULL if either edge may be taken. */ | |
2352 | ||
2353 | static edge | |
2354 | find_taken_edge_computed_goto (basic_block bb, tree val) | |
2355 | { | |
2356 | basic_block dest; | |
2357 | edge e = NULL; | |
2358 | ||
2359 | dest = label_to_block (val); | |
2360 | if (dest) | |
2361 | { | |
2362 | e = find_edge (bb, dest); | |
2363 | gcc_assert (e != NULL); | |
2364 | } | |
2365 | ||
2366 | return e; | |
2367 | } | |
6de9cd9a DN |
2368 | |
2369 | /* Given a constant value VAL and the entry block BB to a COND_EXPR | |
2370 | statement, determine which of the two edges will be taken out of the | |
2371 | block. Return NULL if either edge may be taken. */ | |
2372 | ||
2373 | static edge | |
2374 | find_taken_edge_cond_expr (basic_block bb, tree val) | |
2375 | { | |
2376 | edge true_edge, false_edge; | |
2377 | ||
2378 | extract_true_false_edges_from_block (bb, &true_edge, &false_edge); | |
2379 | ||
6de9cd9a DN |
2380 | /* Otherwise, try to determine which branch of the if() will be taken. |
2381 | If VAL is a constant but it can't be reduced to a 0 or a 1, then | |
2382 | we don't really know which edge will be taken at runtime. This | |
2383 | may happen when comparing addresses (e.g., if (&var1 == 4)). */ | |
2384 | if (integer_nonzerop (val)) | |
2385 | return true_edge; | |
2386 | else if (integer_zerop (val)) | |
2387 | return false_edge; | |
fca01525 KH |
2388 | |
2389 | gcc_unreachable (); | |
6de9cd9a DN |
2390 | } |
2391 | ||
2392 | ||
fca01525 | 2393 | /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR |
6de9cd9a DN |
2394 | statement, determine which edge will be taken out of the block. Return |
2395 | NULL if any edge may be taken. */ | |
2396 | ||
2397 | static edge | |
2398 | find_taken_edge_switch_expr (basic_block bb, tree val) | |
2399 | { | |
2400 | tree switch_expr, taken_case; | |
2401 | basic_block dest_bb; | |
2402 | edge e; | |
2403 | ||
6de9cd9a DN |
2404 | switch_expr = last_stmt (bb); |
2405 | taken_case = find_case_label_for_value (switch_expr, val); | |
2406 | dest_bb = label_to_block (CASE_LABEL (taken_case)); | |
2407 | ||
2408 | e = find_edge (bb, dest_bb); | |
1e128c5f | 2409 | gcc_assert (e); |
6de9cd9a DN |
2410 | return e; |
2411 | } | |
2412 | ||
2413 | ||
f667741c SB |
2414 | /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL. |
2415 | We can make optimal use here of the fact that the case labels are | |
2416 | sorted: We can do a binary search for a case matching VAL. */ | |
6de9cd9a DN |
2417 | |
2418 | static tree | |
2419 | find_case_label_for_value (tree switch_expr, tree val) | |
2420 | { | |
2421 | tree vec = SWITCH_LABELS (switch_expr); | |
f667741c SB |
2422 | size_t low, high, n = TREE_VEC_LENGTH (vec); |
2423 | tree default_case = TREE_VEC_ELT (vec, n - 1); | |
6de9cd9a | 2424 | |
f667741c | 2425 | for (low = -1, high = n - 1; high - low > 1; ) |
6de9cd9a | 2426 | { |
f667741c | 2427 | size_t i = (high + low) / 2; |
6de9cd9a | 2428 | tree t = TREE_VEC_ELT (vec, i); |
f667741c SB |
2429 | int cmp; |
2430 | ||
2431 | /* Cache the result of comparing CASE_LOW and val. */ | |
2432 | cmp = tree_int_cst_compare (CASE_LOW (t), val); | |
6de9cd9a | 2433 | |
f667741c SB |
2434 | if (cmp > 0) |
2435 | high = i; | |
2436 | else | |
2437 | low = i; | |
2438 | ||
2439 | if (CASE_HIGH (t) == NULL) | |
6de9cd9a | 2440 | { |
f667741c SB |
2441 | /* A singe-valued case label. */ |
2442 | if (cmp == 0) | |
6de9cd9a DN |
2443 | return t; |
2444 | } | |
2445 | else | |
2446 | { | |
2447 | /* A case range. We can only handle integer ranges. */ | |
f667741c | 2448 | if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0) |
6de9cd9a DN |
2449 | return t; |
2450 | } | |
2451 | } | |
2452 | ||
6de9cd9a DN |
2453 | return default_case; |
2454 | } | |
2455 | ||
2456 | ||
2457 | /* If all the PHI nodes in DEST have alternatives for E1 and E2 and | |
2458 | those alternatives are equal in each of the PHI nodes, then return | |
2459 | true, else return false. */ | |
2460 | ||
2461 | static bool | |
2462 | phi_alternatives_equal (basic_block dest, edge e1, edge e2) | |
2463 | { | |
5dd8841a KH |
2464 | int n1 = e1->dest_idx; |
2465 | int n2 = e2->dest_idx; | |
2466 | tree phi; | |
6de9cd9a | 2467 | |
17192884 | 2468 | for (phi = phi_nodes (dest); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a | 2469 | { |
5dd8841a KH |
2470 | tree val1 = PHI_ARG_DEF (phi, n1); |
2471 | tree val2 = PHI_ARG_DEF (phi, n2); | |
6de9cd9a | 2472 | |
5dd8841a KH |
2473 | gcc_assert (val1 != NULL_TREE); |
2474 | gcc_assert (val2 != NULL_TREE); | |
6de9cd9a | 2475 | |
cdef8bc6 | 2476 | if (!operand_equal_for_phi_arg_p (val1, val2)) |
6de9cd9a DN |
2477 | return false; |
2478 | } | |
2479 | ||
2480 | return true; | |
2481 | } | |
2482 | ||
2483 | ||
6de9cd9a DN |
2484 | /*--------------------------------------------------------------------------- |
2485 | Debugging functions | |
2486 | ---------------------------------------------------------------------------*/ | |
2487 | ||
2488 | /* Dump tree-specific information of block BB to file OUTF. */ | |
2489 | ||
2490 | void | |
2491 | tree_dump_bb (basic_block bb, FILE *outf, int indent) | |
2492 | { | |
2493 | dump_generic_bb (outf, bb, indent, TDF_VOPS); | |
2494 | } | |
2495 | ||
2496 | ||
2497 | /* Dump a basic block on stderr. */ | |
2498 | ||
2499 | void | |
2500 | debug_tree_bb (basic_block bb) | |
2501 | { | |
2502 | dump_bb (bb, stderr, 0); | |
2503 | } | |
2504 | ||
2505 | ||
2506 | /* Dump basic block with index N on stderr. */ | |
2507 | ||
2508 | basic_block | |
2509 | debug_tree_bb_n (int n) | |
2510 | { | |
2511 | debug_tree_bb (BASIC_BLOCK (n)); | |
2512 | return BASIC_BLOCK (n); | |
2513 | } | |
2514 | ||
2515 | ||
2516 | /* Dump the CFG on stderr. | |
2517 | ||
2518 | FLAGS are the same used by the tree dumping functions | |
2519 | (see TDF_* in tree.h). */ | |
2520 | ||
2521 | void | |
2522 | debug_tree_cfg (int flags) | |
2523 | { | |
2524 | dump_tree_cfg (stderr, flags); | |
2525 | } | |
2526 | ||
2527 | ||
2528 | /* Dump the program showing basic block boundaries on the given FILE. | |
2529 | ||
2530 | FLAGS are the same used by the tree dumping functions (see TDF_* in | |
2531 | tree.h). */ | |
2532 | ||
2533 | void | |
2534 | dump_tree_cfg (FILE *file, int flags) | |
2535 | { | |
2536 | if (flags & TDF_DETAILS) | |
2537 | { | |
2538 | const char *funcname | |
673fda6b | 2539 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
6de9cd9a DN |
2540 | |
2541 | fputc ('\n', file); | |
2542 | fprintf (file, ";; Function %s\n\n", funcname); | |
2543 | fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n", | |
2544 | n_basic_blocks, n_edges, last_basic_block); | |
2545 | ||
2546 | brief_dump_cfg (file); | |
2547 | fprintf (file, "\n"); | |
2548 | } | |
2549 | ||
2550 | if (flags & TDF_STATS) | |
2551 | dump_cfg_stats (file); | |
2552 | ||
2553 | dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS); | |
2554 | } | |
2555 | ||
2556 | ||
2557 | /* Dump CFG statistics on FILE. */ | |
2558 | ||
2559 | void | |
2560 | dump_cfg_stats (FILE *file) | |
2561 | { | |
2562 | static long max_num_merged_labels = 0; | |
2563 | unsigned long size, total = 0; | |
f7fda749 | 2564 | int n_edges; |
6de9cd9a DN |
2565 | basic_block bb; |
2566 | const char * const fmt_str = "%-30s%-13s%12s\n"; | |
f7fda749 | 2567 | const char * const fmt_str_1 = "%-30s%13d%11lu%c\n"; |
6de9cd9a DN |
2568 | const char * const fmt_str_3 = "%-43s%11lu%c\n"; |
2569 | const char *funcname | |
673fda6b | 2570 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
6de9cd9a DN |
2571 | |
2572 | ||
2573 | fprintf (file, "\nCFG Statistics for %s\n\n", funcname); | |
2574 | ||
2575 | fprintf (file, "---------------------------------------------------------\n"); | |
2576 | fprintf (file, fmt_str, "", " Number of ", "Memory"); | |
2577 | fprintf (file, fmt_str, "", " instances ", "used "); | |
2578 | fprintf (file, "---------------------------------------------------------\n"); | |
2579 | ||
2580 | size = n_basic_blocks * sizeof (struct basic_block_def); | |
2581 | total += size; | |
f7fda749 RH |
2582 | fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks, |
2583 | SCALE (size), LABEL (size)); | |
6de9cd9a DN |
2584 | |
2585 | n_edges = 0; | |
2586 | FOR_EACH_BB (bb) | |
628f6a4e | 2587 | n_edges += EDGE_COUNT (bb->succs); |
6de9cd9a DN |
2588 | size = n_edges * sizeof (struct edge_def); |
2589 | total += size; | |
2590 | fprintf (file, fmt_str_1, "Edges", n_edges, SCALE (size), LABEL (size)); | |
2591 | ||
2592 | size = n_basic_blocks * sizeof (struct bb_ann_d); | |
2593 | total += size; | |
2594 | fprintf (file, fmt_str_1, "Basic block annotations", n_basic_blocks, | |
2595 | SCALE (size), LABEL (size)); | |
2596 | ||
2597 | fprintf (file, "---------------------------------------------------------\n"); | |
2598 | fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total), | |
2599 | LABEL (total)); | |
2600 | fprintf (file, "---------------------------------------------------------\n"); | |
2601 | fprintf (file, "\n"); | |
2602 | ||
2603 | if (cfg_stats.num_merged_labels > max_num_merged_labels) | |
2604 | max_num_merged_labels = cfg_stats.num_merged_labels; | |
2605 | ||
2606 | fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n", | |
2607 | cfg_stats.num_merged_labels, max_num_merged_labels); | |
2608 | ||
2609 | fprintf (file, "\n"); | |
2610 | } | |
2611 | ||
2612 | ||
2613 | /* Dump CFG statistics on stderr. Keep extern so that it's always | |
2614 | linked in the final executable. */ | |
2615 | ||
2616 | void | |
2617 | debug_cfg_stats (void) | |
2618 | { | |
2619 | dump_cfg_stats (stderr); | |
2620 | } | |
2621 | ||
2622 | ||
2623 | /* Dump the flowgraph to a .vcg FILE. */ | |
2624 | ||
2625 | static void | |
2626 | tree_cfg2vcg (FILE *file) | |
2627 | { | |
2628 | edge e; | |
628f6a4e | 2629 | edge_iterator ei; |
6de9cd9a DN |
2630 | basic_block bb; |
2631 | const char *funcname | |
673fda6b | 2632 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
6de9cd9a DN |
2633 | |
2634 | /* Write the file header. */ | |
2635 | fprintf (file, "graph: { title: \"%s\"\n", funcname); | |
2636 | fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n"); | |
2637 | fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n"); | |
2638 | ||
2639 | /* Write blocks and edges. */ | |
628f6a4e | 2640 | FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs) |
6de9cd9a DN |
2641 | { |
2642 | fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"", | |
2643 | e->dest->index); | |
2644 | ||
2645 | if (e->flags & EDGE_FAKE) | |
2646 | fprintf (file, " linestyle: dotted priority: 10"); | |
2647 | else | |
2648 | fprintf (file, " linestyle: solid priority: 100"); | |
2649 | ||
2650 | fprintf (file, " }\n"); | |
2651 | } | |
2652 | fputc ('\n', file); | |
2653 | ||
2654 | FOR_EACH_BB (bb) | |
2655 | { | |
2656 | enum tree_code head_code, end_code; | |
2657 | const char *head_name, *end_name; | |
2658 | int head_line = 0; | |
2659 | int end_line = 0; | |
2660 | tree first = first_stmt (bb); | |
2661 | tree last = last_stmt (bb); | |
2662 | ||
2663 | if (first) | |
2664 | { | |
2665 | head_code = TREE_CODE (first); | |
2666 | head_name = tree_code_name[head_code]; | |
2667 | head_line = get_lineno (first); | |
2668 | } | |
2669 | else | |
2670 | head_name = "no-statement"; | |
2671 | ||
2672 | if (last) | |
2673 | { | |
2674 | end_code = TREE_CODE (last); | |
2675 | end_name = tree_code_name[end_code]; | |
2676 | end_line = get_lineno (last); | |
2677 | } | |
2678 | else | |
2679 | end_name = "no-statement"; | |
2680 | ||
2681 | fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n", | |
2682 | bb->index, bb->index, head_name, head_line, end_name, | |
2683 | end_line); | |
2684 | ||
628f6a4e | 2685 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
2686 | { |
2687 | if (e->dest == EXIT_BLOCK_PTR) | |
2688 | fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index); | |
2689 | else | |
2690 | fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index); | |
2691 | ||
2692 | if (e->flags & EDGE_FAKE) | |
2693 | fprintf (file, " priority: 10 linestyle: dotted"); | |
2694 | else | |
2695 | fprintf (file, " priority: 100 linestyle: solid"); | |
2696 | ||
2697 | fprintf (file, " }\n"); | |
2698 | } | |
2699 | ||
2700 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
2701 | fputc ('\n', file); | |
2702 | } | |
2703 | ||
2704 | fputs ("}\n\n", file); | |
2705 | } | |
2706 | ||
2707 | ||
2708 | ||
2709 | /*--------------------------------------------------------------------------- | |
2710 | Miscellaneous helpers | |
2711 | ---------------------------------------------------------------------------*/ | |
2712 | ||
2713 | /* Return true if T represents a stmt that always transfers control. */ | |
2714 | ||
2715 | bool | |
2716 | is_ctrl_stmt (tree t) | |
2717 | { | |
2718 | return (TREE_CODE (t) == COND_EXPR | |
2719 | || TREE_CODE (t) == SWITCH_EXPR | |
2720 | || TREE_CODE (t) == GOTO_EXPR | |
2721 | || TREE_CODE (t) == RETURN_EXPR | |
2722 | || TREE_CODE (t) == RESX_EXPR); | |
2723 | } | |
2724 | ||
2725 | ||
2726 | /* Return true if T is a statement that may alter the flow of control | |
2727 | (e.g., a call to a non-returning function). */ | |
2728 | ||
2729 | bool | |
2730 | is_ctrl_altering_stmt (tree t) | |
2731 | { | |
cd709752 | 2732 | tree call; |
6de9cd9a | 2733 | |
1e128c5f | 2734 | gcc_assert (t); |
cd709752 RH |
2735 | call = get_call_expr_in (t); |
2736 | if (call) | |
6de9cd9a | 2737 | { |
6de9cd9a DN |
2738 | /* A non-pure/const CALL_EXPR alters flow control if the current |
2739 | function has nonlocal labels. */ | |
cd709752 | 2740 | if (TREE_SIDE_EFFECTS (call) && current_function_has_nonlocal_label) |
6de9cd9a DN |
2741 | return true; |
2742 | ||
2743 | /* A CALL_EXPR also alters control flow if it does not return. */ | |
6e14af16 | 2744 | if (call_expr_flags (call) & ECF_NORETURN) |
6de9cd9a | 2745 | return true; |
6de9cd9a DN |
2746 | } |
2747 | ||
2748 | /* If a statement can throw, it alters control flow. */ | |
2749 | return tree_can_throw_internal (t); | |
2750 | } | |
2751 | ||
2752 | ||
2753 | /* Return true if T is a computed goto. */ | |
2754 | ||
2755 | bool | |
2756 | computed_goto_p (tree t) | |
2757 | { | |
2758 | return (TREE_CODE (t) == GOTO_EXPR | |
2759 | && TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL); | |
2760 | } | |
2761 | ||
2762 | ||
2763 | /* Checks whether EXPR is a simple local goto. */ | |
2764 | ||
2765 | bool | |
2766 | simple_goto_p (tree expr) | |
2767 | { | |
ab8907ef RH |
2768 | return (TREE_CODE (expr) == GOTO_EXPR |
2769 | && TREE_CODE (GOTO_DESTINATION (expr)) == LABEL_DECL); | |
6de9cd9a DN |
2770 | } |
2771 | ||
2772 | ||
2773 | /* Return true if T should start a new basic block. PREV_T is the | |
2774 | statement preceding T. It is used when T is a label or a case label. | |
2775 | Labels should only start a new basic block if their previous statement | |
2776 | wasn't a label. Otherwise, sequence of labels would generate | |
2777 | unnecessary basic blocks that only contain a single label. */ | |
2778 | ||
2779 | static inline bool | |
2780 | stmt_starts_bb_p (tree t, tree prev_t) | |
2781 | { | |
6de9cd9a DN |
2782 | if (t == NULL_TREE) |
2783 | return false; | |
2784 | ||
2785 | /* LABEL_EXPRs start a new basic block only if the preceding | |
2786 | statement wasn't a label of the same type. This prevents the | |
2787 | creation of consecutive blocks that have nothing but a single | |
2788 | label. */ | |
229cc11f | 2789 | if (TREE_CODE (t) == LABEL_EXPR) |
6de9cd9a DN |
2790 | { |
2791 | /* Nonlocal and computed GOTO targets always start a new block. */ | |
229cc11f KH |
2792 | if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t)) |
2793 | || FORCED_LABEL (LABEL_EXPR_LABEL (t))) | |
6de9cd9a DN |
2794 | return true; |
2795 | ||
229cc11f | 2796 | if (prev_t && TREE_CODE (prev_t) == LABEL_EXPR) |
6de9cd9a DN |
2797 | { |
2798 | if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t))) | |
2799 | return true; | |
2800 | ||
2801 | cfg_stats.num_merged_labels++; | |
2802 | return false; | |
2803 | } | |
2804 | else | |
2805 | return true; | |
2806 | } | |
2807 | ||
2808 | return false; | |
2809 | } | |
2810 | ||
2811 | ||
2812 | /* Return true if T should end a basic block. */ | |
2813 | ||
2814 | bool | |
2815 | stmt_ends_bb_p (tree t) | |
2816 | { | |
2817 | return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t); | |
2818 | } | |
2819 | ||
2820 | ||
2821 | /* Add gotos that used to be represented implicitly in the CFG. */ | |
2822 | ||
2823 | void | |
2824 | disband_implicit_edges (void) | |
2825 | { | |
2826 | basic_block bb; | |
2827 | block_stmt_iterator last; | |
2828 | edge e; | |
628f6a4e | 2829 | edge_iterator ei; |
eb4e1c01 | 2830 | tree stmt, label; |
6de9cd9a DN |
2831 | |
2832 | FOR_EACH_BB (bb) | |
2833 | { | |
2834 | last = bsi_last (bb); | |
2835 | stmt = last_stmt (bb); | |
2836 | ||
2837 | if (stmt && TREE_CODE (stmt) == COND_EXPR) | |
2838 | { | |
2839 | /* Remove superfluous gotos from COND_EXPR branches. Moved | |
2840 | from cfg_remove_useless_stmts here since it violates the | |
2841 | invariants for tree--cfg correspondence and thus fits better | |
2842 | here where we do it anyway. */ | |
9ff3d2de JL |
2843 | e = find_edge (bb, bb->next_bb); |
2844 | if (e) | |
6de9cd9a | 2845 | { |
6de9cd9a DN |
2846 | if (e->flags & EDGE_TRUE_VALUE) |
2847 | COND_EXPR_THEN (stmt) = build_empty_stmt (); | |
2848 | else if (e->flags & EDGE_FALSE_VALUE) | |
2849 | COND_EXPR_ELSE (stmt) = build_empty_stmt (); | |
2850 | else | |
1e128c5f | 2851 | gcc_unreachable (); |
6de9cd9a DN |
2852 | e->flags |= EDGE_FALLTHRU; |
2853 | } | |
2854 | ||
2855 | continue; | |
2856 | } | |
2857 | ||
2858 | if (stmt && TREE_CODE (stmt) == RETURN_EXPR) | |
2859 | { | |
2860 | /* Remove the RETURN_EXPR if we may fall though to the exit | |
2861 | instead. */ | |
c5cbcccf ZD |
2862 | gcc_assert (single_succ_p (bb)); |
2863 | gcc_assert (single_succ (bb) == EXIT_BLOCK_PTR); | |
6de9cd9a DN |
2864 | |
2865 | if (bb->next_bb == EXIT_BLOCK_PTR | |
2866 | && !TREE_OPERAND (stmt, 0)) | |
2867 | { | |
2868 | bsi_remove (&last); | |
c5cbcccf | 2869 | single_succ_edge (bb)->flags |= EDGE_FALLTHRU; |
6de9cd9a DN |
2870 | } |
2871 | continue; | |
2872 | } | |
2873 | ||
2874 | /* There can be no fallthru edge if the last statement is a control | |
2875 | one. */ | |
2876 | if (stmt && is_ctrl_stmt (stmt)) | |
2877 | continue; | |
2878 | ||
2879 | /* Find a fallthru edge and emit the goto if necessary. */ | |
628f6a4e | 2880 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
2881 | if (e->flags & EDGE_FALLTHRU) |
2882 | break; | |
2883 | ||
62b857ea | 2884 | if (!e || e->dest == bb->next_bb) |
6de9cd9a DN |
2885 | continue; |
2886 | ||
1e128c5f | 2887 | gcc_assert (e->dest != EXIT_BLOCK_PTR); |
6de9cd9a DN |
2888 | label = tree_block_label (e->dest); |
2889 | ||
62b857ea | 2890 | stmt = build1 (GOTO_EXPR, void_type_node, label); |
9506ac2b PB |
2891 | #ifdef USE_MAPPED_LOCATION |
2892 | SET_EXPR_LOCATION (stmt, e->goto_locus); | |
2893 | #else | |
62b857ea | 2894 | SET_EXPR_LOCUS (stmt, e->goto_locus); |
9506ac2b | 2895 | #endif |
62b857ea | 2896 | bsi_insert_after (&last, stmt, BSI_NEW_STMT); |
6de9cd9a DN |
2897 | e->flags &= ~EDGE_FALLTHRU; |
2898 | } | |
2899 | } | |
2900 | ||
242229bb | 2901 | /* Remove block annotations and other datastructures. */ |
6de9cd9a DN |
2902 | |
2903 | void | |
242229bb | 2904 | delete_tree_cfg_annotations (void) |
6de9cd9a | 2905 | { |
242229bb | 2906 | basic_block bb; |
6de9cd9a DN |
2907 | if (n_basic_blocks > 0) |
2908 | free_blocks_annotations (); | |
2909 | ||
6de9cd9a DN |
2910 | label_to_block_map = NULL; |
2911 | free_rbi_pool (); | |
242229bb JH |
2912 | FOR_EACH_BB (bb) |
2913 | bb->rbi = NULL; | |
6de9cd9a DN |
2914 | } |
2915 | ||
2916 | ||
2917 | /* Return the first statement in basic block BB. */ | |
2918 | ||
2919 | tree | |
2920 | first_stmt (basic_block bb) | |
2921 | { | |
2922 | block_stmt_iterator i = bsi_start (bb); | |
2923 | return !bsi_end_p (i) ? bsi_stmt (i) : NULL_TREE; | |
2924 | } | |
2925 | ||
2926 | ||
2927 | /* Return the last statement in basic block BB. */ | |
2928 | ||
2929 | tree | |
2930 | last_stmt (basic_block bb) | |
2931 | { | |
2932 | block_stmt_iterator b = bsi_last (bb); | |
2933 | return !bsi_end_p (b) ? bsi_stmt (b) : NULL_TREE; | |
2934 | } | |
2935 | ||
2936 | ||
2937 | /* Return a pointer to the last statement in block BB. */ | |
2938 | ||
2939 | tree * | |
2940 | last_stmt_ptr (basic_block bb) | |
2941 | { | |
2942 | block_stmt_iterator last = bsi_last (bb); | |
2943 | return !bsi_end_p (last) ? bsi_stmt_ptr (last) : NULL; | |
2944 | } | |
2945 | ||
2946 | ||
2947 | /* Return the last statement of an otherwise empty block. Return NULL | |
2948 | if the block is totally empty, or if it contains more than one | |
2949 | statement. */ | |
2950 | ||
2951 | tree | |
2952 | last_and_only_stmt (basic_block bb) | |
2953 | { | |
2954 | block_stmt_iterator i = bsi_last (bb); | |
2955 | tree last, prev; | |
2956 | ||
2957 | if (bsi_end_p (i)) | |
2958 | return NULL_TREE; | |
2959 | ||
2960 | last = bsi_stmt (i); | |
2961 | bsi_prev (&i); | |
2962 | if (bsi_end_p (i)) | |
2963 | return last; | |
2964 | ||
2965 | /* Empty statements should no longer appear in the instruction stream. | |
2966 | Everything that might have appeared before should be deleted by | |
2967 | remove_useless_stmts, and the optimizers should just bsi_remove | |
2968 | instead of smashing with build_empty_stmt. | |
2969 | ||
2970 | Thus the only thing that should appear here in a block containing | |
2971 | one executable statement is a label. */ | |
2972 | prev = bsi_stmt (i); | |
2973 | if (TREE_CODE (prev) == LABEL_EXPR) | |
2974 | return last; | |
2975 | else | |
2976 | return NULL_TREE; | |
2977 | } | |
2978 | ||
2979 | ||
2980 | /* Mark BB as the basic block holding statement T. */ | |
2981 | ||
2982 | void | |
2983 | set_bb_for_stmt (tree t, basic_block bb) | |
2984 | { | |
30d396e3 ZD |
2985 | if (TREE_CODE (t) == PHI_NODE) |
2986 | PHI_BB (t) = bb; | |
2987 | else if (TREE_CODE (t) == STATEMENT_LIST) | |
6de9cd9a DN |
2988 | { |
2989 | tree_stmt_iterator i; | |
2990 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
2991 | set_bb_for_stmt (tsi_stmt (i), bb); | |
2992 | } | |
2993 | else | |
2994 | { | |
2995 | stmt_ann_t ann = get_stmt_ann (t); | |
2996 | ann->bb = bb; | |
2997 | ||
2998 | /* If the statement is a label, add the label to block-to-labels map | |
2999 | so that we can speed up edge creation for GOTO_EXPRs. */ | |
3000 | if (TREE_CODE (t) == LABEL_EXPR) | |
3001 | { | |
3002 | int uid; | |
3003 | ||
3004 | t = LABEL_EXPR_LABEL (t); | |
3005 | uid = LABEL_DECL_UID (t); | |
3006 | if (uid == -1) | |
3007 | { | |
3008 | LABEL_DECL_UID (t) = uid = cfun->last_label_uid++; | |
3009 | if (VARRAY_SIZE (label_to_block_map) <= (unsigned) uid) | |
3010 | VARRAY_GROW (label_to_block_map, 3 * uid / 2); | |
3011 | } | |
3012 | else | |
1e128c5f GB |
3013 | /* We're moving an existing label. Make sure that we've |
3014 | removed it from the old block. */ | |
3015 | gcc_assert (!bb || !VARRAY_BB (label_to_block_map, uid)); | |
6de9cd9a DN |
3016 | VARRAY_BB (label_to_block_map, uid) = bb; |
3017 | } | |
3018 | } | |
3019 | } | |
3020 | ||
8b11a64c ZD |
3021 | /* Finds iterator for STMT. */ |
3022 | ||
3023 | extern block_stmt_iterator | |
1a1804c2 | 3024 | bsi_for_stmt (tree stmt) |
8b11a64c ZD |
3025 | { |
3026 | block_stmt_iterator bsi; | |
3027 | ||
3028 | for (bsi = bsi_start (bb_for_stmt (stmt)); !bsi_end_p (bsi); bsi_next (&bsi)) | |
3029 | if (bsi_stmt (bsi) == stmt) | |
3030 | return bsi; | |
3031 | ||
1e128c5f | 3032 | gcc_unreachable (); |
8b11a64c | 3033 | } |
6de9cd9a DN |
3034 | |
3035 | /* Insert statement (or statement list) T before the statement | |
3036 | pointed-to by iterator I. M specifies how to update iterator I | |
3037 | after insertion (see enum bsi_iterator_update). */ | |
3038 | ||
3039 | void | |
3040 | bsi_insert_before (block_stmt_iterator *i, tree t, enum bsi_iterator_update m) | |
3041 | { | |
3042 | set_bb_for_stmt (t, i->bb); | |
6de9cd9a | 3043 | tsi_link_before (&i->tsi, t, m); |
68b9f53b | 3044 | modify_stmt (t); |
6de9cd9a DN |
3045 | } |
3046 | ||
3047 | ||
3048 | /* Insert statement (or statement list) T after the statement | |
3049 | pointed-to by iterator I. M specifies how to update iterator I | |
3050 | after insertion (see enum bsi_iterator_update). */ | |
3051 | ||
3052 | void | |
3053 | bsi_insert_after (block_stmt_iterator *i, tree t, enum bsi_iterator_update m) | |
3054 | { | |
3055 | set_bb_for_stmt (t, i->bb); | |
6de9cd9a | 3056 | tsi_link_after (&i->tsi, t, m); |
68b9f53b | 3057 | modify_stmt (t); |
6de9cd9a DN |
3058 | } |
3059 | ||
3060 | ||
3061 | /* Remove the statement pointed to by iterator I. The iterator is updated | |
3062 | to the next statement. */ | |
3063 | ||
3064 | void | |
3065 | bsi_remove (block_stmt_iterator *i) | |
3066 | { | |
3067 | tree t = bsi_stmt (*i); | |
3068 | set_bb_for_stmt (t, NULL); | |
6de9cd9a DN |
3069 | tsi_delink (&i->tsi); |
3070 | } | |
3071 | ||
3072 | ||
3073 | /* Move the statement at FROM so it comes right after the statement at TO. */ | |
3074 | ||
3075 | void | |
3076 | bsi_move_after (block_stmt_iterator *from, block_stmt_iterator *to) | |
3077 | { | |
3078 | tree stmt = bsi_stmt (*from); | |
3079 | bsi_remove (from); | |
3080 | bsi_insert_after (to, stmt, BSI_SAME_STMT); | |
3081 | } | |
3082 | ||
3083 | ||
3084 | /* Move the statement at FROM so it comes right before the statement at TO. */ | |
3085 | ||
3086 | void | |
3087 | bsi_move_before (block_stmt_iterator *from, block_stmt_iterator *to) | |
3088 | { | |
3089 | tree stmt = bsi_stmt (*from); | |
3090 | bsi_remove (from); | |
3091 | bsi_insert_before (to, stmt, BSI_SAME_STMT); | |
3092 | } | |
3093 | ||
3094 | ||
3095 | /* Move the statement at FROM to the end of basic block BB. */ | |
3096 | ||
3097 | void | |
3098 | bsi_move_to_bb_end (block_stmt_iterator *from, basic_block bb) | |
3099 | { | |
3100 | block_stmt_iterator last = bsi_last (bb); | |
3101 | ||
3102 | /* Have to check bsi_end_p because it could be an empty block. */ | |
3103 | if (!bsi_end_p (last) && is_ctrl_stmt (bsi_stmt (last))) | |
3104 | bsi_move_before (from, &last); | |
3105 | else | |
3106 | bsi_move_after (from, &last); | |
3107 | } | |
3108 | ||
3109 | ||
3110 | /* Replace the contents of the statement pointed to by iterator BSI | |
3111 | with STMT. If PRESERVE_EH_INFO is true, the exception handling | |
3112 | information of the original statement is preserved. */ | |
3113 | ||
3114 | void | |
3115 | bsi_replace (const block_stmt_iterator *bsi, tree stmt, bool preserve_eh_info) | |
3116 | { | |
3117 | int eh_region; | |
3118 | tree orig_stmt = bsi_stmt (*bsi); | |
3119 | ||
3120 | SET_EXPR_LOCUS (stmt, EXPR_LOCUS (orig_stmt)); | |
3121 | set_bb_for_stmt (stmt, bsi->bb); | |
3122 | ||
3123 | /* Preserve EH region information from the original statement, if | |
3124 | requested by the caller. */ | |
3125 | if (preserve_eh_info) | |
3126 | { | |
3127 | eh_region = lookup_stmt_eh_region (orig_stmt); | |
3128 | if (eh_region >= 0) | |
3129 | add_stmt_to_eh_region (stmt, eh_region); | |
3130 | } | |
3131 | ||
3132 | *bsi_stmt_ptr (*bsi) = stmt; | |
3133 | modify_stmt (stmt); | |
3134 | } | |
3135 | ||
3136 | ||
3137 | /* Insert the statement pointed-to by BSI into edge E. Every attempt | |
3138 | is made to place the statement in an existing basic block, but | |
3139 | sometimes that isn't possible. When it isn't possible, the edge is | |
3140 | split and the statement is added to the new block. | |
3141 | ||
3142 | In all cases, the returned *BSI points to the correct location. The | |
3143 | return value is true if insertion should be done after the location, | |
82b85a85 ZD |
3144 | or false if it should be done before the location. If new basic block |
3145 | has to be created, it is stored in *NEW_BB. */ | |
6de9cd9a DN |
3146 | |
3147 | static bool | |
82b85a85 ZD |
3148 | tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi, |
3149 | basic_block *new_bb) | |
6de9cd9a DN |
3150 | { |
3151 | basic_block dest, src; | |
3152 | tree tmp; | |
3153 | ||
3154 | dest = e->dest; | |
3155 | restart: | |
3156 | ||
3157 | /* If the destination has one predecessor which has no PHI nodes, | |
3158 | insert there. Except for the exit block. | |
3159 | ||
3160 | The requirement for no PHI nodes could be relaxed. Basically we | |
3161 | would have to examine the PHIs to prove that none of them used | |
e28d0cfb | 3162 | the value set by the statement we want to insert on E. That |
6de9cd9a | 3163 | hardly seems worth the effort. */ |
c5cbcccf | 3164 | if (single_pred_p (dest) |
6de9cd9a DN |
3165 | && ! phi_nodes (dest) |
3166 | && dest != EXIT_BLOCK_PTR) | |
3167 | { | |
3168 | *bsi = bsi_start (dest); | |
3169 | if (bsi_end_p (*bsi)) | |
3170 | return true; | |
3171 | ||
3172 | /* Make sure we insert after any leading labels. */ | |
3173 | tmp = bsi_stmt (*bsi); | |
3174 | while (TREE_CODE (tmp) == LABEL_EXPR) | |
3175 | { | |
3176 | bsi_next (bsi); | |
3177 | if (bsi_end_p (*bsi)) | |
3178 | break; | |
3179 | tmp = bsi_stmt (*bsi); | |
3180 | } | |
3181 | ||
3182 | if (bsi_end_p (*bsi)) | |
3183 | { | |
3184 | *bsi = bsi_last (dest); | |
3185 | return true; | |
3186 | } | |
3187 | else | |
3188 | return false; | |
3189 | } | |
3190 | ||
3191 | /* If the source has one successor, the edge is not abnormal and | |
3192 | the last statement does not end a basic block, insert there. | |
3193 | Except for the entry block. */ | |
3194 | src = e->src; | |
3195 | if ((e->flags & EDGE_ABNORMAL) == 0 | |
c5cbcccf | 3196 | && single_succ_p (src) |
6de9cd9a DN |
3197 | && src != ENTRY_BLOCK_PTR) |
3198 | { | |
3199 | *bsi = bsi_last (src); | |
3200 | if (bsi_end_p (*bsi)) | |
3201 | return true; | |
3202 | ||
3203 | tmp = bsi_stmt (*bsi); | |
3204 | if (!stmt_ends_bb_p (tmp)) | |
3205 | return true; | |
ce068299 JH |
3206 | |
3207 | /* Insert code just before returning the value. We may need to decompose | |
3208 | the return in the case it contains non-trivial operand. */ | |
3209 | if (TREE_CODE (tmp) == RETURN_EXPR) | |
3210 | { | |
3211 | tree op = TREE_OPERAND (tmp, 0); | |
3212 | if (!is_gimple_val (op)) | |
3213 | { | |
1e128c5f | 3214 | gcc_assert (TREE_CODE (op) == MODIFY_EXPR); |
ce068299 JH |
3215 | bsi_insert_before (bsi, op, BSI_NEW_STMT); |
3216 | TREE_OPERAND (tmp, 0) = TREE_OPERAND (op, 0); | |
3217 | } | |
3218 | bsi_prev (bsi); | |
3219 | return true; | |
3220 | } | |
6de9cd9a DN |
3221 | } |
3222 | ||
3223 | /* Otherwise, create a new basic block, and split this edge. */ | |
3224 | dest = split_edge (e); | |
82b85a85 ZD |
3225 | if (new_bb) |
3226 | *new_bb = dest; | |
c5cbcccf | 3227 | e = single_pred_edge (dest); |
6de9cd9a DN |
3228 | goto restart; |
3229 | } | |
3230 | ||
3231 | ||
3232 | /* This routine will commit all pending edge insertions, creating any new | |
8e731e4e | 3233 | basic blocks which are necessary. */ |
6de9cd9a DN |
3234 | |
3235 | void | |
8e731e4e | 3236 | bsi_commit_edge_inserts (void) |
6de9cd9a DN |
3237 | { |
3238 | basic_block bb; | |
3239 | edge e; | |
628f6a4e | 3240 | edge_iterator ei; |
6de9cd9a | 3241 | |
c5cbcccf | 3242 | bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL); |
6de9cd9a DN |
3243 | |
3244 | FOR_EACH_BB (bb) | |
628f6a4e | 3245 | FOR_EACH_EDGE (e, ei, bb->succs) |
edfaf675 | 3246 | bsi_commit_one_edge_insert (e, NULL); |
6de9cd9a DN |
3247 | } |
3248 | ||
3249 | ||
edfaf675 AM |
3250 | /* Commit insertions pending at edge E. If a new block is created, set NEW_BB |
3251 | to this block, otherwise set it to NULL. */ | |
6de9cd9a | 3252 | |
edfaf675 AM |
3253 | void |
3254 | bsi_commit_one_edge_insert (edge e, basic_block *new_bb) | |
6de9cd9a | 3255 | { |
edfaf675 AM |
3256 | if (new_bb) |
3257 | *new_bb = NULL; | |
6de9cd9a DN |
3258 | if (PENDING_STMT (e)) |
3259 | { | |
3260 | block_stmt_iterator bsi; | |
3261 | tree stmt = PENDING_STMT (e); | |
3262 | ||
3263 | PENDING_STMT (e) = NULL_TREE; | |
3264 | ||
edfaf675 | 3265 | if (tree_find_edge_insert_loc (e, &bsi, new_bb)) |
6de9cd9a DN |
3266 | bsi_insert_after (&bsi, stmt, BSI_NEW_STMT); |
3267 | else | |
3268 | bsi_insert_before (&bsi, stmt, BSI_NEW_STMT); | |
3269 | } | |
3270 | } | |
3271 | ||
3272 | ||
3273 | /* Add STMT to the pending list of edge E. No actual insertion is | |
3274 | made until a call to bsi_commit_edge_inserts () is made. */ | |
3275 | ||
3276 | void | |
3277 | bsi_insert_on_edge (edge e, tree stmt) | |
3278 | { | |
3279 | append_to_statement_list (stmt, &PENDING_STMT (e)); | |
3280 | } | |
3281 | ||
adb35797 KH |
3282 | /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new |
3283 | block has to be created, it is returned. */ | |
82b85a85 ZD |
3284 | |
3285 | basic_block | |
3286 | bsi_insert_on_edge_immediate (edge e, tree stmt) | |
3287 | { | |
3288 | block_stmt_iterator bsi; | |
3289 | basic_block new_bb = NULL; | |
3290 | ||
1e128c5f | 3291 | gcc_assert (!PENDING_STMT (e)); |
82b85a85 ZD |
3292 | |
3293 | if (tree_find_edge_insert_loc (e, &bsi, &new_bb)) | |
3294 | bsi_insert_after (&bsi, stmt, BSI_NEW_STMT); | |
3295 | else | |
3296 | bsi_insert_before (&bsi, stmt, BSI_NEW_STMT); | |
3297 | ||
3298 | return new_bb; | |
3299 | } | |
6de9cd9a | 3300 | |
6de9cd9a DN |
3301 | /*--------------------------------------------------------------------------- |
3302 | Tree specific functions for CFG manipulation | |
3303 | ---------------------------------------------------------------------------*/ | |
3304 | ||
4f7db7f7 KH |
3305 | /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */ |
3306 | ||
3307 | static void | |
3308 | reinstall_phi_args (edge new_edge, edge old_edge) | |
3309 | { | |
3310 | tree var, phi; | |
3311 | ||
3312 | if (!PENDING_STMT (old_edge)) | |
3313 | return; | |
3314 | ||
3315 | for (var = PENDING_STMT (old_edge), phi = phi_nodes (new_edge->dest); | |
3316 | var && phi; | |
3317 | var = TREE_CHAIN (var), phi = PHI_CHAIN (phi)) | |
3318 | { | |
3319 | tree result = TREE_PURPOSE (var); | |
3320 | tree arg = TREE_VALUE (var); | |
3321 | ||
3322 | gcc_assert (result == PHI_RESULT (phi)); | |
3323 | ||
d2e398df | 3324 | add_phi_arg (phi, arg, new_edge); |
4f7db7f7 KH |
3325 | } |
3326 | ||
3327 | PENDING_STMT (old_edge) = NULL; | |
3328 | } | |
3329 | ||
6de9cd9a DN |
3330 | /* Split a (typically critical) edge EDGE_IN. Return the new block. |
3331 | Abort on abnormal edges. */ | |
3332 | ||
3333 | static basic_block | |
3334 | tree_split_edge (edge edge_in) | |
3335 | { | |
3336 | basic_block new_bb, after_bb, dest, src; | |
3337 | edge new_edge, e; | |
6de9cd9a DN |
3338 | |
3339 | /* Abnormal edges cannot be split. */ | |
1e128c5f | 3340 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
6de9cd9a DN |
3341 | |
3342 | src = edge_in->src; | |
3343 | dest = edge_in->dest; | |
3344 | ||
3345 | /* Place the new block in the block list. Try to keep the new block | |
3346 | near its "logical" location. This is of most help to humans looking | |
3347 | at debugging dumps. */ | |
7510740d | 3348 | if (dest->prev_bb && find_edge (dest->prev_bb, dest)) |
6de9cd9a | 3349 | after_bb = edge_in->src; |
7510740d KH |
3350 | else |
3351 | after_bb = dest->prev_bb; | |
6de9cd9a DN |
3352 | |
3353 | new_bb = create_empty_bb (after_bb); | |
b829f3fa JH |
3354 | new_bb->frequency = EDGE_FREQUENCY (edge_in); |
3355 | new_bb->count = edge_in->count; | |
6de9cd9a | 3356 | new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU); |
b829f3fa JH |
3357 | new_edge->probability = REG_BR_PROB_BASE; |
3358 | new_edge->count = edge_in->count; | |
6de9cd9a | 3359 | |
1e128c5f GB |
3360 | e = redirect_edge_and_branch (edge_in, new_bb); |
3361 | gcc_assert (e); | |
4f7db7f7 | 3362 | reinstall_phi_args (new_edge, e); |
6de9cd9a DN |
3363 | |
3364 | return new_bb; | |
3365 | } | |
3366 | ||
3367 | ||
3368 | /* Return true when BB has label LABEL in it. */ | |
3369 | ||
3370 | static bool | |
3371 | has_label_p (basic_block bb, tree label) | |
3372 | { | |
3373 | block_stmt_iterator bsi; | |
3374 | ||
3375 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
3376 | { | |
3377 | tree stmt = bsi_stmt (bsi); | |
3378 | ||
3379 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
3380 | return false; | |
3381 | if (LABEL_EXPR_LABEL (stmt) == label) | |
3382 | return true; | |
3383 | } | |
3384 | return false; | |
3385 | } | |
3386 | ||
3387 | ||
3388 | /* Callback for walk_tree, check that all elements with address taken are | |
7a442a1d SB |
3389 | properly noticed as such. The DATA is an int* that is 1 if TP was seen |
3390 | inside a PHI node. */ | |
6de9cd9a DN |
3391 | |
3392 | static tree | |
2fbe90f2 | 3393 | verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) |
6de9cd9a DN |
3394 | { |
3395 | tree t = *tp, x; | |
7a442a1d | 3396 | bool in_phi = (data != NULL); |
6de9cd9a DN |
3397 | |
3398 | if (TYPE_P (t)) | |
3399 | *walk_subtrees = 0; | |
2fbe90f2 | 3400 | |
50b04185 RK |
3401 | /* Check operand N for being valid GIMPLE and give error MSG if not. |
3402 | We check for constants explicitly since they are not considered | |
3403 | gimple invariants if they overflowed. */ | |
2fbe90f2 | 3404 | #define CHECK_OP(N, MSG) \ |
6615c446 JO |
3405 | do { if (!CONSTANT_CLASS_P (TREE_OPERAND (t, N)) \ |
3406 | && !is_gimple_val (TREE_OPERAND (t, N))) \ | |
2fbe90f2 | 3407 | { error (MSG); return TREE_OPERAND (t, N); }} while (0) |
6de9cd9a DN |
3408 | |
3409 | switch (TREE_CODE (t)) | |
3410 | { | |
3411 | case SSA_NAME: | |
3412 | if (SSA_NAME_IN_FREE_LIST (t)) | |
3413 | { | |
3414 | error ("SSA name in freelist but still referenced"); | |
3415 | return *tp; | |
3416 | } | |
3417 | break; | |
3418 | ||
3419 | case MODIFY_EXPR: | |
3420 | x = TREE_OPERAND (t, 0); | |
3421 | if (TREE_CODE (x) == BIT_FIELD_REF | |
3422 | && is_gimple_reg (TREE_OPERAND (x, 0))) | |
3423 | { | |
3424 | error ("GIMPLE register modified with BIT_FIELD_REF"); | |
2fbe90f2 | 3425 | return t; |
6de9cd9a DN |
3426 | } |
3427 | break; | |
3428 | ||
3429 | case ADDR_EXPR: | |
7a442a1d SB |
3430 | /* ??? tree-ssa-alias.c may have overlooked dead PHI nodes, missing |
3431 | dead PHIs that take the address of something. But if the PHI | |
3432 | result is dead, the fact that it takes the address of anything | |
3433 | is irrelevant. Because we can not tell from here if a PHI result | |
3434 | is dead, we just skip this check for PHIs altogether. This means | |
3435 | we may be missing "valid" checks, but what can you do? | |
3436 | This was PR19217. */ | |
3437 | if (in_phi) | |
3438 | break; | |
3439 | ||
2fbe90f2 RK |
3440 | /* Skip any references (they will be checked when we recurse down the |
3441 | tree) and ensure that any variable used as a prefix is marked | |
3442 | addressable. */ | |
3443 | for (x = TREE_OPERAND (t, 0); | |
afe84921 | 3444 | handled_component_p (x); |
44de5aeb RK |
3445 | x = TREE_OPERAND (x, 0)) |
3446 | ; | |
3447 | ||
6de9cd9a DN |
3448 | if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL) |
3449 | return NULL; | |
3450 | if (!TREE_ADDRESSABLE (x)) | |
3451 | { | |
3452 | error ("address taken, but ADDRESSABLE bit not set"); | |
3453 | return x; | |
3454 | } | |
3455 | break; | |
3456 | ||
3457 | case COND_EXPR: | |
a6234684 | 3458 | x = COND_EXPR_COND (t); |
6de9cd9a DN |
3459 | if (TREE_CODE (TREE_TYPE (x)) != BOOLEAN_TYPE) |
3460 | { | |
3461 | error ("non-boolean used in condition"); | |
3462 | return x; | |
3463 | } | |
3464 | break; | |
3465 | ||
3466 | case NOP_EXPR: | |
3467 | case CONVERT_EXPR: | |
3468 | case FIX_TRUNC_EXPR: | |
3469 | case FIX_CEIL_EXPR: | |
3470 | case FIX_FLOOR_EXPR: | |
3471 | case FIX_ROUND_EXPR: | |
3472 | case FLOAT_EXPR: | |
3473 | case NEGATE_EXPR: | |
3474 | case ABS_EXPR: | |
3475 | case BIT_NOT_EXPR: | |
3476 | case NON_LVALUE_EXPR: | |
3477 | case TRUTH_NOT_EXPR: | |
2fbe90f2 | 3478 | CHECK_OP (0, "Invalid operand to unary operator"); |
6de9cd9a DN |
3479 | break; |
3480 | ||
3481 | case REALPART_EXPR: | |
3482 | case IMAGPART_EXPR: | |
2fbe90f2 RK |
3483 | case COMPONENT_REF: |
3484 | case ARRAY_REF: | |
3485 | case ARRAY_RANGE_REF: | |
3486 | case BIT_FIELD_REF: | |
3487 | case VIEW_CONVERT_EXPR: | |
3488 | /* We have a nest of references. Verify that each of the operands | |
3489 | that determine where to reference is either a constant or a variable, | |
3490 | verify that the base is valid, and then show we've already checked | |
3491 | the subtrees. */ | |
afe84921 | 3492 | while (handled_component_p (t)) |
2fbe90f2 RK |
3493 | { |
3494 | if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2)) | |
3495 | CHECK_OP (2, "Invalid COMPONENT_REF offset operator"); | |
3496 | else if (TREE_CODE (t) == ARRAY_REF | |
3497 | || TREE_CODE (t) == ARRAY_RANGE_REF) | |
3498 | { | |
3499 | CHECK_OP (1, "Invalid array index."); | |
3500 | if (TREE_OPERAND (t, 2)) | |
3501 | CHECK_OP (2, "Invalid array lower bound."); | |
3502 | if (TREE_OPERAND (t, 3)) | |
3503 | CHECK_OP (3, "Invalid array stride."); | |
3504 | } | |
3505 | else if (TREE_CODE (t) == BIT_FIELD_REF) | |
3506 | { | |
3507 | CHECK_OP (1, "Invalid operand to BIT_FIELD_REF"); | |
3508 | CHECK_OP (2, "Invalid operand to BIT_FIELD_REF"); | |
3509 | } | |
3510 | ||
3511 | t = TREE_OPERAND (t, 0); | |
3512 | } | |
3513 | ||
6615c446 | 3514 | if (!CONSTANT_CLASS_P (t) && !is_gimple_lvalue (t)) |
2fbe90f2 RK |
3515 | { |
3516 | error ("Invalid reference prefix."); | |
3517 | return t; | |
3518 | } | |
3519 | *walk_subtrees = 0; | |
6de9cd9a DN |
3520 | break; |
3521 | ||
3522 | case LT_EXPR: | |
3523 | case LE_EXPR: | |
3524 | case GT_EXPR: | |
3525 | case GE_EXPR: | |
3526 | case EQ_EXPR: | |
3527 | case NE_EXPR: | |
3528 | case UNORDERED_EXPR: | |
3529 | case ORDERED_EXPR: | |
3530 | case UNLT_EXPR: | |
3531 | case UNLE_EXPR: | |
3532 | case UNGT_EXPR: | |
3533 | case UNGE_EXPR: | |
3534 | case UNEQ_EXPR: | |
d1a7edaf | 3535 | case LTGT_EXPR: |
6de9cd9a DN |
3536 | case PLUS_EXPR: |
3537 | case MINUS_EXPR: | |
3538 | case MULT_EXPR: | |
3539 | case TRUNC_DIV_EXPR: | |
3540 | case CEIL_DIV_EXPR: | |
3541 | case FLOOR_DIV_EXPR: | |
3542 | case ROUND_DIV_EXPR: | |
3543 | case TRUNC_MOD_EXPR: | |
3544 | case CEIL_MOD_EXPR: | |
3545 | case FLOOR_MOD_EXPR: | |
3546 | case ROUND_MOD_EXPR: | |
3547 | case RDIV_EXPR: | |
3548 | case EXACT_DIV_EXPR: | |
3549 | case MIN_EXPR: | |
3550 | case MAX_EXPR: | |
3551 | case LSHIFT_EXPR: | |
3552 | case RSHIFT_EXPR: | |
3553 | case LROTATE_EXPR: | |
3554 | case RROTATE_EXPR: | |
3555 | case BIT_IOR_EXPR: | |
3556 | case BIT_XOR_EXPR: | |
3557 | case BIT_AND_EXPR: | |
50b04185 RK |
3558 | CHECK_OP (0, "Invalid operand to binary operator"); |
3559 | CHECK_OP (1, "Invalid operand to binary operator"); | |
6de9cd9a DN |
3560 | break; |
3561 | ||
3562 | default: | |
3563 | break; | |
3564 | } | |
3565 | return NULL; | |
2fbe90f2 RK |
3566 | |
3567 | #undef CHECK_OP | |
6de9cd9a DN |
3568 | } |
3569 | ||
3570 | ||
3571 | /* Verify STMT, return true if STMT is not in GIMPLE form. | |
3572 | TODO: Implement type checking. */ | |
3573 | ||
3574 | static bool | |
1eaba2f2 | 3575 | verify_stmt (tree stmt, bool last_in_block) |
6de9cd9a DN |
3576 | { |
3577 | tree addr; | |
3578 | ||
3579 | if (!is_gimple_stmt (stmt)) | |
3580 | { | |
3581 | error ("Is not a valid GIMPLE statement."); | |
1eaba2f2 | 3582 | goto fail; |
6de9cd9a DN |
3583 | } |
3584 | ||
3585 | addr = walk_tree (&stmt, verify_expr, NULL, NULL); | |
3586 | if (addr) | |
3587 | { | |
3588 | debug_generic_stmt (addr); | |
3589 | return true; | |
3590 | } | |
3591 | ||
1eaba2f2 RH |
3592 | /* If the statement is marked as part of an EH region, then it is |
3593 | expected that the statement could throw. Verify that when we | |
3594 | have optimizations that simplify statements such that we prove | |
3595 | that they cannot throw, that we update other data structures | |
3596 | to match. */ | |
3597 | if (lookup_stmt_eh_region (stmt) >= 0) | |
3598 | { | |
3599 | if (!tree_could_throw_p (stmt)) | |
3600 | { | |
971801ff | 3601 | error ("Statement marked for throw, but doesn%'t."); |
1eaba2f2 RH |
3602 | goto fail; |
3603 | } | |
3604 | if (!last_in_block && tree_can_throw_internal (stmt)) | |
3605 | { | |
3606 | error ("Statement marked for throw in middle of block."); | |
3607 | goto fail; | |
3608 | } | |
3609 | } | |
3610 | ||
6de9cd9a | 3611 | return false; |
1eaba2f2 RH |
3612 | |
3613 | fail: | |
3614 | debug_generic_stmt (stmt); | |
3615 | return true; | |
6de9cd9a DN |
3616 | } |
3617 | ||
3618 | ||
3619 | /* Return true when the T can be shared. */ | |
3620 | ||
3621 | static bool | |
3622 | tree_node_can_be_shared (tree t) | |
3623 | { | |
6615c446 | 3624 | if (IS_TYPE_OR_DECL_P (t) |
6de9cd9a DN |
3625 | /* We check for constants explicitly since they are not considered |
3626 | gimple invariants if they overflowed. */ | |
6615c446 | 3627 | || CONSTANT_CLASS_P (t) |
6de9cd9a | 3628 | || is_gimple_min_invariant (t) |
5e23162d | 3629 | || TREE_CODE (t) == SSA_NAME |
bac8beb4 | 3630 | || t == error_mark_node) |
6de9cd9a DN |
3631 | return true; |
3632 | ||
92b6dff3 JL |
3633 | if (TREE_CODE (t) == CASE_LABEL_EXPR) |
3634 | return true; | |
3635 | ||
44de5aeb | 3636 | while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF) |
6de9cd9a DN |
3637 | /* We check for constants explicitly since they are not considered |
3638 | gimple invariants if they overflowed. */ | |
6615c446 | 3639 | && (CONSTANT_CLASS_P (TREE_OPERAND (t, 1)) |
6de9cd9a DN |
3640 | || is_gimple_min_invariant (TREE_OPERAND (t, 1)))) |
3641 | || (TREE_CODE (t) == COMPONENT_REF | |
3642 | || TREE_CODE (t) == REALPART_EXPR | |
3643 | || TREE_CODE (t) == IMAGPART_EXPR)) | |
3644 | t = TREE_OPERAND (t, 0); | |
3645 | ||
3646 | if (DECL_P (t)) | |
3647 | return true; | |
3648 | ||
3649 | return false; | |
3650 | } | |
3651 | ||
3652 | ||
3653 | /* Called via walk_trees. Verify tree sharing. */ | |
3654 | ||
3655 | static tree | |
3656 | verify_node_sharing (tree * tp, int *walk_subtrees, void *data) | |
3657 | { | |
3658 | htab_t htab = (htab_t) data; | |
3659 | void **slot; | |
3660 | ||
3661 | if (tree_node_can_be_shared (*tp)) | |
3662 | { | |
3663 | *walk_subtrees = false; | |
3664 | return NULL; | |
3665 | } | |
3666 | ||
3667 | slot = htab_find_slot (htab, *tp, INSERT); | |
3668 | if (*slot) | |
3669 | return *slot; | |
3670 | *slot = *tp; | |
3671 | ||
3672 | return NULL; | |
3673 | } | |
3674 | ||
3675 | ||
3676 | /* Verify the GIMPLE statement chain. */ | |
3677 | ||
3678 | void | |
3679 | verify_stmts (void) | |
3680 | { | |
3681 | basic_block bb; | |
3682 | block_stmt_iterator bsi; | |
3683 | bool err = false; | |
3684 | htab_t htab; | |
3685 | tree addr; | |
3686 | ||
3687 | timevar_push (TV_TREE_STMT_VERIFY); | |
3688 | htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); | |
3689 | ||
3690 | FOR_EACH_BB (bb) | |
3691 | { | |
3692 | tree phi; | |
3693 | int i; | |
3694 | ||
17192884 | 3695 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
3696 | { |
3697 | int phi_num_args = PHI_NUM_ARGS (phi); | |
3698 | ||
8de1fc1b KH |
3699 | if (bb_for_stmt (phi) != bb) |
3700 | { | |
3701 | error ("bb_for_stmt (phi) is set to a wrong basic block\n"); | |
3702 | err |= true; | |
3703 | } | |
3704 | ||
6de9cd9a DN |
3705 | for (i = 0; i < phi_num_args; i++) |
3706 | { | |
3707 | tree t = PHI_ARG_DEF (phi, i); | |
3708 | tree addr; | |
3709 | ||
3710 | /* Addressable variables do have SSA_NAMEs but they | |
3711 | are not considered gimple values. */ | |
3712 | if (TREE_CODE (t) != SSA_NAME | |
3713 | && TREE_CODE (t) != FUNCTION_DECL | |
3714 | && !is_gimple_val (t)) | |
3715 | { | |
3716 | error ("PHI def is not a GIMPLE value"); | |
3717 | debug_generic_stmt (phi); | |
3718 | debug_generic_stmt (t); | |
3719 | err |= true; | |
3720 | } | |
3721 | ||
7a442a1d | 3722 | addr = walk_tree (&t, verify_expr, (void *) 1, NULL); |
6de9cd9a DN |
3723 | if (addr) |
3724 | { | |
3725 | debug_generic_stmt (addr); | |
3726 | err |= true; | |
3727 | } | |
3728 | ||
3729 | addr = walk_tree (&t, verify_node_sharing, htab, NULL); | |
3730 | if (addr) | |
3731 | { | |
3732 | error ("Incorrect sharing of tree nodes"); | |
3733 | debug_generic_stmt (phi); | |
3734 | debug_generic_stmt (addr); | |
3735 | err |= true; | |
3736 | } | |
3737 | } | |
3738 | } | |
3739 | ||
1eaba2f2 | 3740 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); ) |
6de9cd9a DN |
3741 | { |
3742 | tree stmt = bsi_stmt (bsi); | |
8de1fc1b KH |
3743 | |
3744 | if (bb_for_stmt (stmt) != bb) | |
3745 | { | |
3746 | error ("bb_for_stmt (stmt) is set to a wrong basic block\n"); | |
3747 | err |= true; | |
3748 | } | |
3749 | ||
1eaba2f2 RH |
3750 | bsi_next (&bsi); |
3751 | err |= verify_stmt (stmt, bsi_end_p (bsi)); | |
6de9cd9a DN |
3752 | addr = walk_tree (&stmt, verify_node_sharing, htab, NULL); |
3753 | if (addr) | |
3754 | { | |
3755 | error ("Incorrect sharing of tree nodes"); | |
3756 | debug_generic_stmt (stmt); | |
3757 | debug_generic_stmt (addr); | |
3758 | err |= true; | |
3759 | } | |
3760 | } | |
3761 | } | |
3762 | ||
3763 | if (err) | |
3764 | internal_error ("verify_stmts failed."); | |
3765 | ||
3766 | htab_delete (htab); | |
3767 | timevar_pop (TV_TREE_STMT_VERIFY); | |
3768 | } | |
3769 | ||
3770 | ||
3771 | /* Verifies that the flow information is OK. */ | |
3772 | ||
3773 | static int | |
3774 | tree_verify_flow_info (void) | |
3775 | { | |
3776 | int err = 0; | |
3777 | basic_block bb; | |
3778 | block_stmt_iterator bsi; | |
3779 | tree stmt; | |
3780 | edge e; | |
628f6a4e | 3781 | edge_iterator ei; |
6de9cd9a DN |
3782 | |
3783 | if (ENTRY_BLOCK_PTR->stmt_list) | |
3784 | { | |
3785 | error ("ENTRY_BLOCK has a statement list associated with it\n"); | |
3786 | err = 1; | |
3787 | } | |
3788 | ||
3789 | if (EXIT_BLOCK_PTR->stmt_list) | |
3790 | { | |
3791 | error ("EXIT_BLOCK has a statement list associated with it\n"); | |
3792 | err = 1; | |
3793 | } | |
3794 | ||
628f6a4e | 3795 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds) |
6de9cd9a DN |
3796 | if (e->flags & EDGE_FALLTHRU) |
3797 | { | |
3798 | error ("Fallthru to exit from bb %d\n", e->src->index); | |
3799 | err = 1; | |
3800 | } | |
3801 | ||
3802 | FOR_EACH_BB (bb) | |
3803 | { | |
3804 | bool found_ctrl_stmt = false; | |
3805 | ||
548414c6 KH |
3806 | stmt = NULL_TREE; |
3807 | ||
6de9cd9a DN |
3808 | /* Skip labels on the start of basic block. */ |
3809 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
3810 | { | |
548414c6 KH |
3811 | tree prev_stmt = stmt; |
3812 | ||
3813 | stmt = bsi_stmt (bsi); | |
3814 | ||
3815 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
6de9cd9a DN |
3816 | break; |
3817 | ||
548414c6 KH |
3818 | if (prev_stmt && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))) |
3819 | { | |
3820 | error ("Nonlocal label %s is not first " | |
cde68236 | 3821 | "in a sequence of labels in bb %d", |
548414c6 KH |
3822 | IDENTIFIER_POINTER (DECL_NAME (LABEL_EXPR_LABEL (stmt))), |
3823 | bb->index); | |
3824 | err = 1; | |
3825 | } | |
3826 | ||
3827 | if (label_to_block (LABEL_EXPR_LABEL (stmt)) != bb) | |
6de9cd9a DN |
3828 | { |
3829 | error ("Label %s to block does not match in bb %d\n", | |
77568960 | 3830 | IDENTIFIER_POINTER (DECL_NAME (LABEL_EXPR_LABEL (stmt))), |
6de9cd9a DN |
3831 | bb->index); |
3832 | err = 1; | |
3833 | } | |
3834 | ||
548414c6 | 3835 | if (decl_function_context (LABEL_EXPR_LABEL (stmt)) |
6de9cd9a DN |
3836 | != current_function_decl) |
3837 | { | |
3838 | error ("Label %s has incorrect context in bb %d\n", | |
77568960 | 3839 | IDENTIFIER_POINTER (DECL_NAME (LABEL_EXPR_LABEL (stmt))), |
6de9cd9a DN |
3840 | bb->index); |
3841 | err = 1; | |
3842 | } | |
3843 | } | |
3844 | ||
3845 | /* Verify that body of basic block BB is free of control flow. */ | |
3846 | for (; !bsi_end_p (bsi); bsi_next (&bsi)) | |
3847 | { | |
3848 | tree stmt = bsi_stmt (bsi); | |
3849 | ||
3850 | if (found_ctrl_stmt) | |
3851 | { | |
3852 | error ("Control flow in the middle of basic block %d\n", | |
3853 | bb->index); | |
3854 | err = 1; | |
3855 | } | |
3856 | ||
3857 | if (stmt_ends_bb_p (stmt)) | |
3858 | found_ctrl_stmt = true; | |
3859 | ||
3860 | if (TREE_CODE (stmt) == LABEL_EXPR) | |
3861 | { | |
3862 | error ("Label %s in the middle of basic block %d\n", | |
3863 | IDENTIFIER_POINTER (DECL_NAME (stmt)), | |
3864 | bb->index); | |
3865 | err = 1; | |
3866 | } | |
3867 | } | |
3868 | bsi = bsi_last (bb); | |
3869 | if (bsi_end_p (bsi)) | |
3870 | continue; | |
3871 | ||
3872 | stmt = bsi_stmt (bsi); | |
3873 | ||
3874 | if (is_ctrl_stmt (stmt)) | |
3875 | { | |
628f6a4e | 3876 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
3877 | if (e->flags & EDGE_FALLTHRU) |
3878 | { | |
3879 | error ("Fallthru edge after a control statement in bb %d \n", | |
3880 | bb->index); | |
3881 | err = 1; | |
3882 | } | |
3883 | } | |
3884 | ||
3885 | switch (TREE_CODE (stmt)) | |
3886 | { | |
3887 | case COND_EXPR: | |
3888 | { | |
3889 | edge true_edge; | |
3890 | edge false_edge; | |
3891 | if (TREE_CODE (COND_EXPR_THEN (stmt)) != GOTO_EXPR | |
3892 | || TREE_CODE (COND_EXPR_ELSE (stmt)) != GOTO_EXPR) | |
3893 | { | |
3894 | error ("Structured COND_EXPR at the end of bb %d\n", bb->index); | |
3895 | err = 1; | |
3896 | } | |
3897 | ||
3898 | extract_true_false_edges_from_block (bb, &true_edge, &false_edge); | |
3899 | ||
3900 | if (!true_edge || !false_edge | |
3901 | || !(true_edge->flags & EDGE_TRUE_VALUE) | |
3902 | || !(false_edge->flags & EDGE_FALSE_VALUE) | |
3903 | || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL)) | |
3904 | || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL)) | |
628f6a4e | 3905 | || EDGE_COUNT (bb->succs) >= 3) |
6de9cd9a DN |
3906 | { |
3907 | error ("Wrong outgoing edge flags at end of bb %d\n", | |
3908 | bb->index); | |
3909 | err = 1; | |
3910 | } | |
3911 | ||
3912 | if (!has_label_p (true_edge->dest, | |
3913 | GOTO_DESTINATION (COND_EXPR_THEN (stmt)))) | |
3914 | { | |
971801ff | 3915 | error ("%<then%> label does not match edge at end of bb %d\n", |
6de9cd9a DN |
3916 | bb->index); |
3917 | err = 1; | |
3918 | } | |
3919 | ||
3920 | if (!has_label_p (false_edge->dest, | |
3921 | GOTO_DESTINATION (COND_EXPR_ELSE (stmt)))) | |
3922 | { | |
971801ff | 3923 | error ("%<else%> label does not match edge at end of bb %d\n", |
6de9cd9a DN |
3924 | bb->index); |
3925 | err = 1; | |
3926 | } | |
3927 | } | |
3928 | break; | |
3929 | ||
3930 | case GOTO_EXPR: | |
3931 | if (simple_goto_p (stmt)) | |
3932 | { | |
3933 | error ("Explicit goto at end of bb %d\n", bb->index); | |
3934 | err = 1; | |
3935 | } | |
3936 | else | |
3937 | { | |
3938 | /* FIXME. We should double check that the labels in the | |
3939 | destination blocks have their address taken. */ | |
628f6a4e | 3940 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
3941 | if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE |
3942 | | EDGE_FALSE_VALUE)) | |
3943 | || !(e->flags & EDGE_ABNORMAL)) | |
3944 | { | |
3945 | error ("Wrong outgoing edge flags at end of bb %d\n", | |
3946 | bb->index); | |
3947 | err = 1; | |
3948 | } | |
3949 | } | |
3950 | break; | |
3951 | ||
3952 | case RETURN_EXPR: | |
c5cbcccf ZD |
3953 | if (!single_succ_p (bb) |
3954 | || (single_succ_edge (bb)->flags | |
3955 | & (EDGE_FALLTHRU | EDGE_ABNORMAL | |
3956 | | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))) | |
6de9cd9a DN |
3957 | { |
3958 | error ("Wrong outgoing edge flags at end of bb %d\n", bb->index); | |
3959 | err = 1; | |
3960 | } | |
c5cbcccf | 3961 | if (single_succ (bb) != EXIT_BLOCK_PTR) |
6de9cd9a DN |
3962 | { |
3963 | error ("Return edge does not point to exit in bb %d\n", | |
3964 | bb->index); | |
3965 | err = 1; | |
3966 | } | |
3967 | break; | |
3968 | ||
3969 | case SWITCH_EXPR: | |
3970 | { | |
7853504d | 3971 | tree prev; |
6de9cd9a DN |
3972 | edge e; |
3973 | size_t i, n; | |
3974 | tree vec; | |
3975 | ||
3976 | vec = SWITCH_LABELS (stmt); | |
3977 | n = TREE_VEC_LENGTH (vec); | |
3978 | ||
3979 | /* Mark all the destination basic blocks. */ | |
3980 | for (i = 0; i < n; ++i) | |
3981 | { | |
3982 | tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i)); | |
3983 | basic_block label_bb = label_to_block (lab); | |
3984 | ||
1e128c5f | 3985 | gcc_assert (!label_bb->aux || label_bb->aux == (void *)1); |
6de9cd9a DN |
3986 | label_bb->aux = (void *)1; |
3987 | } | |
3988 | ||
7853504d SB |
3989 | /* Verify that the case labels are sorted. */ |
3990 | prev = TREE_VEC_ELT (vec, 0); | |
3991 | for (i = 1; i < n - 1; ++i) | |
3992 | { | |
3993 | tree c = TREE_VEC_ELT (vec, i); | |
3994 | if (! CASE_LOW (c)) | |
3995 | { | |
3996 | error ("Found default case not at end of case vector"); | |
3997 | err = 1; | |
3998 | continue; | |
3999 | } | |
4000 | if (! tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c))) | |
4001 | { | |
4002 | error ("Case labels not sorted:\n "); | |
4003 | print_generic_expr (stderr, prev, 0); | |
4004 | fprintf (stderr," is greater than "); | |
4005 | print_generic_expr (stderr, c, 0); | |
4006 | fprintf (stderr," but comes before it.\n"); | |
4007 | err = 1; | |
4008 | } | |
4009 | prev = c; | |
4010 | } | |
4011 | if (CASE_LOW (TREE_VEC_ELT (vec, n - 1))) | |
4012 | { | |
4013 | error ("No default case found at end of case vector"); | |
4014 | err = 1; | |
4015 | } | |
4016 | ||
628f6a4e | 4017 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
4018 | { |
4019 | if (!e->dest->aux) | |
4020 | { | |
4021 | error ("Extra outgoing edge %d->%d\n", | |
4022 | bb->index, e->dest->index); | |
4023 | err = 1; | |
4024 | } | |
4025 | e->dest->aux = (void *)2; | |
4026 | if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL | |
4027 | | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))) | |
4028 | { | |
4029 | error ("Wrong outgoing edge flags at end of bb %d\n", | |
4030 | bb->index); | |
4031 | err = 1; | |
4032 | } | |
4033 | } | |
4034 | ||
4035 | /* Check that we have all of them. */ | |
4036 | for (i = 0; i < n; ++i) | |
4037 | { | |
4038 | tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i)); | |
4039 | basic_block label_bb = label_to_block (lab); | |
4040 | ||
4041 | if (label_bb->aux != (void *)2) | |
4042 | { | |
6ade0959 | 4043 | error ("Missing edge %i->%i", |
6de9cd9a DN |
4044 | bb->index, label_bb->index); |
4045 | err = 1; | |
4046 | } | |
4047 | } | |
4048 | ||
628f6a4e | 4049 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
4050 | e->dest->aux = (void *)0; |
4051 | } | |
4052 | ||
4053 | default: ; | |
4054 | } | |
4055 | } | |
4056 | ||
4057 | if (dom_computed[CDI_DOMINATORS] >= DOM_NO_FAST_QUERY) | |
4058 | verify_dominators (CDI_DOMINATORS); | |
4059 | ||
4060 | return err; | |
4061 | } | |
4062 | ||
4063 | ||
f0b698c1 | 4064 | /* Updates phi nodes after creating a forwarder block joined |
6de9cd9a DN |
4065 | by edge FALLTHRU. */ |
4066 | ||
4067 | static void | |
4068 | tree_make_forwarder_block (edge fallthru) | |
4069 | { | |
4070 | edge e; | |
628f6a4e | 4071 | edge_iterator ei; |
6de9cd9a | 4072 | basic_block dummy, bb; |
5ae71719 | 4073 | tree phi, new_phi, var; |
6de9cd9a DN |
4074 | |
4075 | dummy = fallthru->src; | |
4076 | bb = fallthru->dest; | |
4077 | ||
c5cbcccf | 4078 | if (single_pred_p (bb)) |
6de9cd9a DN |
4079 | return; |
4080 | ||
4081 | /* If we redirected a branch we must create new phi nodes at the | |
4082 | start of BB. */ | |
17192884 | 4083 | for (phi = phi_nodes (dummy); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
4084 | { |
4085 | var = PHI_RESULT (phi); | |
4086 | new_phi = create_phi_node (var, bb); | |
4087 | SSA_NAME_DEF_STMT (var) = new_phi; | |
d00ad49b | 4088 | SET_PHI_RESULT (phi, make_ssa_name (SSA_NAME_VAR (var), phi)); |
d2e398df | 4089 | add_phi_arg (new_phi, PHI_RESULT (phi), fallthru); |
6de9cd9a DN |
4090 | } |
4091 | ||
17192884 | 4092 | /* Ensure that the PHI node chain is in the same order. */ |
5ae71719 | 4093 | set_phi_nodes (bb, phi_reverse (phi_nodes (bb))); |
6de9cd9a DN |
4094 | |
4095 | /* Add the arguments we have stored on edges. */ | |
628f6a4e | 4096 | FOR_EACH_EDGE (e, ei, bb->preds) |
6de9cd9a DN |
4097 | { |
4098 | if (e == fallthru) | |
4099 | continue; | |
4100 | ||
71882046 | 4101 | flush_pending_stmts (e); |
6de9cd9a DN |
4102 | } |
4103 | } | |
4104 | ||
4105 | ||
4106 | /* Return true if basic block BB does nothing except pass control | |
4107 | flow to another block and that we can safely insert a label at | |
10a52335 KH |
4108 | the start of the successor block. |
4109 | ||
4110 | As a precondition, we require that BB be not equal to | |
4111 | ENTRY_BLOCK_PTR. */ | |
6de9cd9a DN |
4112 | |
4113 | static bool | |
23ab2e4e | 4114 | tree_forwarder_block_p (basic_block bb, bool phi_wanted) |
6de9cd9a DN |
4115 | { |
4116 | block_stmt_iterator bsi; | |
6de9cd9a | 4117 | |
10a52335 | 4118 | /* BB must have a single outgoing edge. */ |
c5cbcccf | 4119 | if (single_succ_p (bb) != 1 |
23ab2e4e KH |
4120 | /* If PHI_WANTED is false, BB must not have any PHI nodes. |
4121 | Otherwise, BB must have PHI nodes. */ | |
4122 | || (phi_nodes (bb) != NULL_TREE) != phi_wanted | |
10a52335 | 4123 | /* BB may not be a predecessor of EXIT_BLOCK_PTR. */ |
c5cbcccf | 4124 | || single_succ (bb) == EXIT_BLOCK_PTR |
63bb59a3 | 4125 | /* Nor should this be an infinite loop. */ |
c5cbcccf | 4126 | || single_succ (bb) == bb |
10a52335 | 4127 | /* BB may not have an abnormal outgoing edge. */ |
c5cbcccf | 4128 | || (single_succ_edge (bb)->flags & EDGE_ABNORMAL)) |
78b6731d | 4129 | return false; |
6de9cd9a | 4130 | |
10a52335 KH |
4131 | #if ENABLE_CHECKING |
4132 | gcc_assert (bb != ENTRY_BLOCK_PTR); | |
4133 | #endif | |
4134 | ||
f8ef82ea KH |
4135 | /* Now walk through the statements backward. We can ignore labels, |
4136 | anything else means this is not a forwarder block. */ | |
4137 | for (bsi = bsi_last (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
6de9cd9a DN |
4138 | { |
4139 | tree stmt = bsi_stmt (bsi); | |
4140 | ||
4141 | switch (TREE_CODE (stmt)) | |
4142 | { | |
4143 | case LABEL_EXPR: | |
4144 | if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))) | |
4145 | return false; | |
4146 | break; | |
4147 | ||
4148 | default: | |
6de9cd9a DN |
4149 | return false; |
4150 | } | |
4151 | } | |
4152 | ||
91d9ede4 KH |
4153 | if (find_edge (ENTRY_BLOCK_PTR, bb)) |
4154 | return false; | |
4155 | ||
2b271002 ZD |
4156 | if (current_loops) |
4157 | { | |
4158 | basic_block dest; | |
4159 | /* Protect loop latches, headers and preheaders. */ | |
4160 | if (bb->loop_father->header == bb) | |
4161 | return false; | |
4162 | dest = EDGE_SUCC (bb, 0)->dest; | |
4163 | ||
4164 | if (dest->loop_father->header == dest) | |
4165 | return false; | |
4166 | } | |
4167 | ||
6de9cd9a DN |
4168 | return true; |
4169 | } | |
4170 | ||
63bb59a3 ZD |
4171 | /* Return true if BB has at least one abnormal incoming edge. */ |
4172 | ||
4173 | static inline bool | |
4174 | has_abnormal_incoming_edge_p (basic_block bb) | |
4175 | { | |
4176 | edge e; | |
4177 | edge_iterator ei; | |
4178 | ||
4179 | FOR_EACH_EDGE (e, ei, bb->preds) | |
4180 | if (e->flags & EDGE_ABNORMAL) | |
4181 | return true; | |
4182 | ||
4183 | return false; | |
4184 | } | |
4185 | ||
adb35797 | 4186 | /* Removes forwarder block BB. Returns false if this failed. If a new |
63bb59a3 ZD |
4187 | forwarder block is created due to redirection of edges, it is |
4188 | stored to worklist. */ | |
072269d8 KH |
4189 | |
4190 | static bool | |
63bb59a3 | 4191 | remove_forwarder_block (basic_block bb, basic_block **worklist) |
072269d8 | 4192 | { |
c5cbcccf | 4193 | edge succ = single_succ_edge (bb), e, s; |
63bb59a3 ZD |
4194 | basic_block dest = succ->dest; |
4195 | tree label; | |
4196 | tree phi; | |
072269d8 | 4197 | edge_iterator ei; |
63bb59a3 ZD |
4198 | block_stmt_iterator bsi, bsi_to; |
4199 | bool seen_abnormal_edge = false; | |
4200 | ||
4201 | /* We check for infinite loops already in tree_forwarder_block_p. | |
4202 | However it may happen that the infinite loop is created | |
4203 | afterwards due to removal of forwarders. */ | |
4204 | if (dest == bb) | |
4205 | return false; | |
072269d8 | 4206 | |
a85ba5a8 | 4207 | /* If the destination block consists of a nonlocal label, do not merge |
63bb59a3 | 4208 | it. */ |
04d38c3b | 4209 | label = first_stmt (dest); |
63bb59a3 ZD |
4210 | if (label |
4211 | && TREE_CODE (label) == LABEL_EXPR | |
4212 | && DECL_NONLOCAL (LABEL_EXPR_LABEL (label))) | |
4213 | return false; | |
4214 | ||
4215 | /* If there is an abnormal edge to basic block BB, but not into | |
4216 | dest, problems might occur during removal of the phi node at out | |
4217 | of ssa due to overlapping live ranges of registers. | |
4218 | ||
4219 | If there is an abnormal edge in DEST, the problems would occur | |
4220 | anyway since cleanup_dead_labels would then merge the labels for | |
4221 | two different eh regions, and rest of exception handling code | |
4222 | does not like it. | |
4223 | ||
4224 | So if there is an abnormal edge to BB, proceed only if there is | |
4225 | no abnormal edge to DEST and there are no phi nodes in DEST. */ | |
4226 | if (has_abnormal_incoming_edge_p (bb)) | |
072269d8 | 4227 | { |
63bb59a3 | 4228 | seen_abnormal_edge = true; |
072269d8 | 4229 | |
63bb59a3 ZD |
4230 | if (has_abnormal_incoming_edge_p (dest) |
4231 | || phi_nodes (dest) != NULL_TREE) | |
4232 | return false; | |
4233 | } | |
072269d8 | 4234 | |
63bb59a3 ZD |
4235 | /* If there are phi nodes in DEST, and some of the blocks that are |
4236 | predecessors of BB are also predecessors of DEST, check that the | |
4237 | phi node arguments match. */ | |
4238 | if (phi_nodes (dest)) | |
4239 | { | |
4240 | FOR_EACH_EDGE (e, ei, bb->preds) | |
072269d8 | 4241 | { |
63bb59a3 ZD |
4242 | s = find_edge (e->src, dest); |
4243 | if (!s) | |
4244 | continue; | |
4245 | ||
4246 | if (!phi_alternatives_equal (dest, succ, s)) | |
4247 | return false; | |
072269d8 | 4248 | } |
63bb59a3 | 4249 | } |
072269d8 | 4250 | |
63bb59a3 ZD |
4251 | /* Redirect the edges. */ |
4252 | for (ei = ei_start (bb->preds); (e = ei_safe_edge (ei)); ) | |
4253 | { | |
4254 | if (e->flags & EDGE_ABNORMAL) | |
072269d8 | 4255 | { |
63bb59a3 ZD |
4256 | /* If there is an abnormal edge, redirect it anyway, and |
4257 | move the labels to the new block to make it legal. */ | |
4258 | s = redirect_edge_succ_nodup (e, dest); | |
072269d8 | 4259 | } |
63bb59a3 ZD |
4260 | else |
4261 | s = redirect_edge_and_branch (e, dest); | |
072269d8 | 4262 | |
63bb59a3 | 4263 | if (s == e) |
072269d8 | 4264 | { |
63bb59a3 ZD |
4265 | /* Create arguments for the phi nodes, since the edge was not |
4266 | here before. */ | |
072269d8 | 4267 | for (phi = phi_nodes (dest); phi; phi = PHI_CHAIN (phi)) |
63bb59a3 | 4268 | add_phi_arg (phi, PHI_ARG_DEF (phi, succ->dest_idx), s); |
072269d8 | 4269 | } |
63bb59a3 | 4270 | else |
072269d8 | 4271 | { |
63bb59a3 ZD |
4272 | /* The source basic block might become a forwarder. We know |
4273 | that it was not a forwarder before, since it used to have | |
4274 | at least two outgoing edges, so we may just add it to | |
4275 | worklist. */ | |
23ab2e4e | 4276 | if (tree_forwarder_block_p (s->src, false)) |
63bb59a3 | 4277 | *(*worklist)++ = s->src; |
072269d8 | 4278 | } |
63bb59a3 | 4279 | } |
072269d8 | 4280 | |
63bb59a3 ZD |
4281 | if (seen_abnormal_edge) |
4282 | { | |
4283 | /* Move the labels to the new block, so that the redirection of | |
4284 | the abnormal edges works. */ | |
072269d8 | 4285 | |
63bb59a3 ZD |
4286 | bsi_to = bsi_start (dest); |
4287 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); ) | |
4288 | { | |
4289 | label = bsi_stmt (bsi); | |
4290 | gcc_assert (TREE_CODE (label) == LABEL_EXPR); | |
4291 | bsi_remove (&bsi); | |
4292 | bsi_insert_before (&bsi_to, label, BSI_CONTINUE_LINKING); | |
072269d8 KH |
4293 | } |
4294 | } | |
4295 | ||
63bb59a3 ZD |
4296 | /* Update the dominators. */ |
4297 | if (dom_info_available_p (CDI_DOMINATORS)) | |
4298 | { | |
4299 | basic_block dom, dombb, domdest; | |
4300 | ||
4301 | dombb = get_immediate_dominator (CDI_DOMINATORS, bb); | |
4302 | domdest = get_immediate_dominator (CDI_DOMINATORS, dest); | |
4303 | if (domdest == bb) | |
4304 | { | |
4305 | /* Shortcut to avoid calling (relatively expensive) | |
4306 | nearest_common_dominator unless necessary. */ | |
4307 | dom = dombb; | |
4308 | } | |
4309 | else | |
4310 | dom = nearest_common_dominator (CDI_DOMINATORS, domdest, dombb); | |
072269d8 | 4311 | |
63bb59a3 ZD |
4312 | set_immediate_dominator (CDI_DOMINATORS, dest, dom); |
4313 | } | |
6de9cd9a | 4314 | |
63bb59a3 ZD |
4315 | /* And kill the forwarder block. */ |
4316 | delete_basic_block (bb); | |
6de9cd9a | 4317 | |
63bb59a3 ZD |
4318 | return true; |
4319 | } | |
2abacef0 | 4320 | |
63bb59a3 | 4321 | /* Removes forwarder blocks. */ |
072269d8 | 4322 | |
6de9cd9a | 4323 | static bool |
63bb59a3 | 4324 | cleanup_forwarder_blocks (void) |
6de9cd9a | 4325 | { |
072269d8 | 4326 | basic_block bb; |
63bb59a3 | 4327 | bool changed = false; |
29cc8719 | 4328 | basic_block *worklist = xmalloc (sizeof (basic_block) * n_basic_blocks); |
31864f59 | 4329 | basic_block *current = worklist; |
6de9cd9a DN |
4330 | |
4331 | FOR_EACH_BB (bb) | |
08445125 | 4332 | { |
23ab2e4e | 4333 | if (tree_forwarder_block_p (bb, false)) |
63bb59a3 | 4334 | *current++ = bb; |
08445125 | 4335 | } |
6de9cd9a | 4336 | |
63bb59a3 | 4337 | while (current != worklist) |
08445125 | 4338 | { |
31864f59 | 4339 | bb = *--current; |
63bb59a3 | 4340 | changed |= remove_forwarder_block (bb, ¤t); |
6de9cd9a | 4341 | } |
08445125 KH |
4342 | |
4343 | free (worklist); | |
63bb59a3 | 4344 | return changed; |
6de9cd9a DN |
4345 | } |
4346 | ||
23ab2e4e KH |
4347 | /* Merge the PHI nodes at BB into those at BB's sole successor. */ |
4348 | ||
4349 | static void | |
4350 | remove_forwarder_block_with_phi (basic_block bb) | |
4351 | { | |
c5cbcccf | 4352 | edge succ = single_succ_edge (bb); |
23ab2e4e | 4353 | basic_block dest = succ->dest; |
28773f15 | 4354 | tree label; |
23ab2e4e | 4355 | basic_block dombb, domdest, dom; |
23ab2e4e KH |
4356 | |
4357 | /* We check for infinite loops already in tree_forwarder_block_p. | |
4358 | However it may happen that the infinite loop is created | |
4359 | afterwards due to removal of forwarders. */ | |
4360 | if (dest == bb) | |
4361 | return; | |
4362 | ||
4363 | /* If the destination block consists of a nonlocal label, do not | |
4364 | merge it. */ | |
28773f15 KH |
4365 | label = first_stmt (dest); |
4366 | if (label | |
4367 | && TREE_CODE (label) == LABEL_EXPR | |
4368 | && DECL_NONLOCAL (LABEL_EXPR_LABEL (label))) | |
4369 | return; | |
23ab2e4e KH |
4370 | |
4371 | /* Redirect each incoming edge to BB to DEST. */ | |
4372 | while (EDGE_COUNT (bb->preds) > 0) | |
4373 | { | |
4374 | edge e = EDGE_PRED (bb, 0), s; | |
4375 | tree phi; | |
4376 | ||
4377 | s = find_edge (e->src, dest); | |
4378 | if (s) | |
4379 | { | |
4380 | /* We already have an edge S from E->src to DEST. If S and | |
4381 | E->dest's sole successor edge have the same PHI arguments | |
4382 | at DEST, redirect S to DEST. */ | |
4383 | if (phi_alternatives_equal (dest, s, succ)) | |
4384 | { | |
4385 | e = redirect_edge_and_branch (e, dest); | |
4386 | PENDING_STMT (e) = NULL_TREE; | |
4387 | continue; | |
4388 | } | |
4389 | ||
a85ba5a8 | 4390 | /* PHI arguments are different. Create a forwarder block by |
23ab2e4e KH |
4391 | splitting E so that we can merge PHI arguments on E to |
4392 | DEST. */ | |
c5cbcccf | 4393 | e = single_succ_edge (split_edge (e)); |
23ab2e4e KH |
4394 | } |
4395 | ||
4396 | s = redirect_edge_and_branch (e, dest); | |
4397 | ||
4398 | /* redirect_edge_and_branch must not create a new edge. */ | |
4399 | gcc_assert (s == e); | |
4400 | ||
4401 | /* Add to the PHI nodes at DEST each PHI argument removed at the | |
4402 | destination of E. */ | |
4403 | for (phi = phi_nodes (dest); phi; phi = PHI_CHAIN (phi)) | |
4404 | { | |
4405 | tree def = PHI_ARG_DEF (phi, succ->dest_idx); | |
4406 | ||
4407 | if (TREE_CODE (def) == SSA_NAME) | |
4408 | { | |
4409 | tree var; | |
4410 | ||
4411 | /* If DEF is one of the results of PHI nodes removed during | |
4412 | redirection, replace it with the PHI argument that used | |
4413 | to be on E. */ | |
4414 | for (var = PENDING_STMT (e); var; var = TREE_CHAIN (var)) | |
4415 | { | |
4416 | tree old_arg = TREE_PURPOSE (var); | |
4417 | tree new_arg = TREE_VALUE (var); | |
4418 | ||
4419 | if (def == old_arg) | |
4420 | { | |
4421 | def = new_arg; | |
4422 | break; | |
4423 | } | |
4424 | } | |
4425 | } | |
4426 | ||
4427 | add_phi_arg (phi, def, s); | |
4428 | } | |
4429 | ||
4430 | PENDING_STMT (e) = NULL; | |
4431 | } | |
4432 | ||
4433 | /* Update the dominators. */ | |
4434 | dombb = get_immediate_dominator (CDI_DOMINATORS, bb); | |
4435 | domdest = get_immediate_dominator (CDI_DOMINATORS, dest); | |
4436 | if (domdest == bb) | |
4437 | { | |
4438 | /* Shortcut to avoid calling (relatively expensive) | |
4439 | nearest_common_dominator unless necessary. */ | |
4440 | dom = dombb; | |
4441 | } | |
4442 | else | |
4443 | dom = nearest_common_dominator (CDI_DOMINATORS, domdest, dombb); | |
4444 | ||
4445 | set_immediate_dominator (CDI_DOMINATORS, dest, dom); | |
4446 | ||
4447 | /* Remove BB since all of BB's incoming edges have been redirected | |
4448 | to DEST. */ | |
4449 | delete_basic_block (bb); | |
4450 | } | |
4451 | ||
a85ba5a8 KH |
4452 | /* This pass merges PHI nodes if one feeds into another. For example, |
4453 | suppose we have the following: | |
23ab2e4e KH |
4454 | |
4455 | goto <bb 9> (<L9>); | |
4456 | ||
4457 | <L8>:; | |
4458 | tem_17 = foo (); | |
4459 | ||
4460 | # tem_6 = PHI <tem_17(8), tem_23(7)>; | |
4461 | <L9>:; | |
4462 | ||
4463 | # tem_3 = PHI <tem_6(9), tem_2(5)>; | |
4464 | <L10>:; | |
4465 | ||
4466 | Then we merge the first PHI node into the second one like so: | |
4467 | ||
4468 | goto <bb 9> (<L10>); | |
4469 | ||
4470 | <L8>:; | |
4471 | tem_17 = foo (); | |
4472 | ||
4473 | # tem_3 = PHI <tem_23(7), tem_2(5), tem_17(8)>; | |
4474 | <L10>:; | |
4475 | */ | |
4476 | ||
4477 | static void | |
4478 | merge_phi_nodes (void) | |
4479 | { | |
4480 | basic_block *worklist = xmalloc (sizeof (basic_block) * n_basic_blocks); | |
4481 | basic_block *current = worklist; | |
4482 | basic_block bb; | |
4483 | ||
4484 | calculate_dominance_info (CDI_DOMINATORS); | |
4485 | ||
4486 | /* Find all PHI nodes that we may be able to merge. */ | |
4487 | FOR_EACH_BB (bb) | |
4488 | { | |
4489 | basic_block dest; | |
4490 | ||
4491 | /* Look for a forwarder block with PHI nodes. */ | |
4492 | if (!tree_forwarder_block_p (bb, true)) | |
4493 | continue; | |
4494 | ||
c5cbcccf | 4495 | dest = single_succ (bb); |
23ab2e4e KH |
4496 | |
4497 | /* We have to feed into another basic block with PHI | |
4498 | nodes. */ | |
4499 | if (!phi_nodes (dest) | |
4500 | /* We don't want to deal with a basic block with | |
4501 | abnormal edges. */ | |
4502 | || has_abnormal_incoming_edge_p (bb)) | |
4503 | continue; | |
4504 | ||
4505 | if (!dominated_by_p (CDI_DOMINATORS, dest, bb)) | |
4506 | { | |
4507 | /* If BB does not dominate DEST, then the PHI nodes at | |
4508 | DEST must be the only users of the results of the PHI | |
4509 | nodes at BB. */ | |
4510 | *current++ = bb; | |
4511 | } | |
4512 | } | |
4513 | ||
4514 | /* Now let's drain WORKLIST. */ | |
4515 | while (current != worklist) | |
4516 | { | |
4517 | bb = *--current; | |
4518 | remove_forwarder_block_with_phi (bb); | |
4519 | } | |
4520 | ||
4521 | free (worklist); | |
4522 | } | |
4523 | ||
4524 | static bool | |
4525 | gate_merge_phi (void) | |
4526 | { | |
4527 | return 1; | |
4528 | } | |
4529 | ||
4530 | struct tree_opt_pass pass_merge_phi = { | |
4531 | "mergephi", /* name */ | |
4532 | gate_merge_phi, /* gate */ | |
4533 | merge_phi_nodes, /* execute */ | |
4534 | NULL, /* sub */ | |
4535 | NULL, /* next */ | |
4536 | 0, /* static_pass_number */ | |
4537 | TV_TREE_MERGE_PHI, /* tv_id */ | |
4538 | PROP_cfg | PROP_ssa, /* properties_required */ | |
4539 | 0, /* properties_provided */ | |
4540 | 0, /* properties_destroyed */ | |
4541 | 0, /* todo_flags_start */ | |
4542 | TODO_dump_func | TODO_ggc_collect /* todo_flags_finish */ | |
4543 | | TODO_verify_ssa, | |
4544 | 0 /* letter */ | |
4545 | }; | |
4546 | ||
6de9cd9a DN |
4547 | /* Return a non-special label in the head of basic block BLOCK. |
4548 | Create one if it doesn't exist. */ | |
4549 | ||
d7621d3c | 4550 | tree |
6de9cd9a DN |
4551 | tree_block_label (basic_block bb) |
4552 | { | |
4553 | block_stmt_iterator i, s = bsi_start (bb); | |
4554 | bool first = true; | |
4555 | tree label, stmt; | |
4556 | ||
4557 | for (i = s; !bsi_end_p (i); first = false, bsi_next (&i)) | |
4558 | { | |
4559 | stmt = bsi_stmt (i); | |
4560 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
4561 | break; | |
4562 | label = LABEL_EXPR_LABEL (stmt); | |
4563 | if (!DECL_NONLOCAL (label)) | |
4564 | { | |
4565 | if (!first) | |
4566 | bsi_move_before (&i, &s); | |
4567 | return label; | |
4568 | } | |
4569 | } | |
4570 | ||
4571 | label = create_artificial_label (); | |
4572 | stmt = build1 (LABEL_EXPR, void_type_node, label); | |
4573 | bsi_insert_before (&s, stmt, BSI_NEW_STMT); | |
4574 | return label; | |
4575 | } | |
4576 | ||
4577 | ||
4578 | /* Attempt to perform edge redirection by replacing a possibly complex | |
4579 | jump instruction by a goto or by removing the jump completely. | |
4580 | This can apply only if all edges now point to the same block. The | |
4581 | parameters and return values are equivalent to | |
4582 | redirect_edge_and_branch. */ | |
4583 | ||
4584 | static edge | |
4585 | tree_try_redirect_by_replacing_jump (edge e, basic_block target) | |
4586 | { | |
4587 | basic_block src = e->src; | |
6de9cd9a DN |
4588 | block_stmt_iterator b; |
4589 | tree stmt; | |
6de9cd9a | 4590 | |
07b43a87 KH |
4591 | /* We can replace or remove a complex jump only when we have exactly |
4592 | two edges. */ | |
4593 | if (EDGE_COUNT (src->succs) != 2 | |
4594 | /* Verify that all targets will be TARGET. Specifically, the | |
4595 | edge that is not E must also go to TARGET. */ | |
4596 | || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target) | |
6de9cd9a DN |
4597 | return NULL; |
4598 | ||
4599 | b = bsi_last (src); | |
4600 | if (bsi_end_p (b)) | |
4601 | return NULL; | |
4602 | stmt = bsi_stmt (b); | |
4603 | ||
4604 | if (TREE_CODE (stmt) == COND_EXPR | |
4605 | || TREE_CODE (stmt) == SWITCH_EXPR) | |
4606 | { | |
4607 | bsi_remove (&b); | |
4608 | e = ssa_redirect_edge (e, target); | |
4609 | e->flags = EDGE_FALLTHRU; | |
4610 | return e; | |
4611 | } | |
4612 | ||
4613 | return NULL; | |
4614 | } | |
4615 | ||
4616 | ||
4617 | /* Redirect E to DEST. Return NULL on failure. Otherwise, return the | |
4618 | edge representing the redirected branch. */ | |
4619 | ||
4620 | static edge | |
4621 | tree_redirect_edge_and_branch (edge e, basic_block dest) | |
4622 | { | |
4623 | basic_block bb = e->src; | |
4624 | block_stmt_iterator bsi; | |
4625 | edge ret; | |
4626 | tree label, stmt; | |
4627 | ||
4628 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
4629 | return NULL; | |
4630 | ||
4631 | if (e->src != ENTRY_BLOCK_PTR | |
4632 | && (ret = tree_try_redirect_by_replacing_jump (e, dest))) | |
4633 | return ret; | |
4634 | ||
4635 | if (e->dest == dest) | |
4636 | return NULL; | |
4637 | ||
4638 | label = tree_block_label (dest); | |
4639 | ||
4640 | bsi = bsi_last (bb); | |
4641 | stmt = bsi_end_p (bsi) ? NULL : bsi_stmt (bsi); | |
4642 | ||
4643 | switch (stmt ? TREE_CODE (stmt) : ERROR_MARK) | |
4644 | { | |
4645 | case COND_EXPR: | |
4646 | stmt = (e->flags & EDGE_TRUE_VALUE | |
4647 | ? COND_EXPR_THEN (stmt) | |
4648 | : COND_EXPR_ELSE (stmt)); | |
4649 | GOTO_DESTINATION (stmt) = label; | |
4650 | break; | |
4651 | ||
4652 | case GOTO_EXPR: | |
4653 | /* No non-abnormal edges should lead from a non-simple goto, and | |
4654 | simple ones should be represented implicitly. */ | |
1e128c5f | 4655 | gcc_unreachable (); |
6de9cd9a DN |
4656 | |
4657 | case SWITCH_EXPR: | |
4658 | { | |
d6be0d7f | 4659 | tree cases = get_cases_for_edge (e, stmt); |
6de9cd9a | 4660 | |
d6be0d7f JL |
4661 | /* If we have a list of cases associated with E, then use it |
4662 | as it's a lot faster than walking the entire case vector. */ | |
4663 | if (cases) | |
6de9cd9a | 4664 | { |
4edbbd3f | 4665 | edge e2 = find_edge (e->src, dest); |
d6be0d7f JL |
4666 | tree last, first; |
4667 | ||
4668 | first = cases; | |
4669 | while (cases) | |
4670 | { | |
4671 | last = cases; | |
4672 | CASE_LABEL (cases) = label; | |
4673 | cases = TREE_CHAIN (cases); | |
4674 | } | |
4675 | ||
4676 | /* If there was already an edge in the CFG, then we need | |
4677 | to move all the cases associated with E to E2. */ | |
4678 | if (e2) | |
4679 | { | |
4680 | tree cases2 = get_cases_for_edge (e2, stmt); | |
4681 | ||
4682 | TREE_CHAIN (last) = TREE_CHAIN (cases2); | |
4683 | TREE_CHAIN (cases2) = first; | |
4684 | } | |
6de9cd9a | 4685 | } |
92b6dff3 JL |
4686 | else |
4687 | { | |
d6be0d7f JL |
4688 | tree vec = SWITCH_LABELS (stmt); |
4689 | size_t i, n = TREE_VEC_LENGTH (vec); | |
4690 | ||
4691 | for (i = 0; i < n; i++) | |
4692 | { | |
4693 | tree elt = TREE_VEC_ELT (vec, i); | |
4694 | ||
4695 | if (label_to_block (CASE_LABEL (elt)) == e->dest) | |
4696 | CASE_LABEL (elt) = label; | |
4697 | } | |
92b6dff3 | 4698 | } |
d6be0d7f | 4699 | |
92b6dff3 | 4700 | break; |
6de9cd9a | 4701 | } |
6de9cd9a DN |
4702 | |
4703 | case RETURN_EXPR: | |
4704 | bsi_remove (&bsi); | |
4705 | e->flags |= EDGE_FALLTHRU; | |
4706 | break; | |
4707 | ||
4708 | default: | |
4709 | /* Otherwise it must be a fallthru edge, and we don't need to | |
4710 | do anything besides redirecting it. */ | |
1e128c5f | 4711 | gcc_assert (e->flags & EDGE_FALLTHRU); |
6de9cd9a DN |
4712 | break; |
4713 | } | |
4714 | ||
4715 | /* Update/insert PHI nodes as necessary. */ | |
4716 | ||
4717 | /* Now update the edges in the CFG. */ | |
4718 | e = ssa_redirect_edge (e, dest); | |
4719 | ||
4720 | return e; | |
4721 | } | |
4722 | ||
4723 | ||
4724 | /* Simple wrapper, as we can always redirect fallthru edges. */ | |
4725 | ||
4726 | static basic_block | |
4727 | tree_redirect_edge_and_branch_force (edge e, basic_block dest) | |
4728 | { | |
4729 | e = tree_redirect_edge_and_branch (e, dest); | |
1e128c5f | 4730 | gcc_assert (e); |
6de9cd9a DN |
4731 | |
4732 | return NULL; | |
4733 | } | |
4734 | ||
4735 | ||
4736 | /* Splits basic block BB after statement STMT (but at least after the | |
4737 | labels). If STMT is NULL, BB is split just after the labels. */ | |
4738 | ||
4739 | static basic_block | |
4740 | tree_split_block (basic_block bb, void *stmt) | |
4741 | { | |
4742 | block_stmt_iterator bsi, bsi_tgt; | |
4743 | tree act; | |
4744 | basic_block new_bb; | |
4745 | edge e; | |
628f6a4e | 4746 | edge_iterator ei; |
6de9cd9a DN |
4747 | |
4748 | new_bb = create_empty_bb (bb); | |
4749 | ||
4750 | /* Redirect the outgoing edges. */ | |
628f6a4e BE |
4751 | new_bb->succs = bb->succs; |
4752 | bb->succs = NULL; | |
4753 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
6de9cd9a DN |
4754 | e->src = new_bb; |
4755 | ||
4756 | if (stmt && TREE_CODE ((tree) stmt) == LABEL_EXPR) | |
4757 | stmt = NULL; | |
4758 | ||
4759 | /* Move everything from BSI to the new basic block. */ | |
4760 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
4761 | { | |
4762 | act = bsi_stmt (bsi); | |
4763 | if (TREE_CODE (act) == LABEL_EXPR) | |
4764 | continue; | |
4765 | ||
4766 | if (!stmt) | |
4767 | break; | |
4768 | ||
4769 | if (stmt == act) | |
4770 | { | |
4771 | bsi_next (&bsi); | |
4772 | break; | |
4773 | } | |
4774 | } | |
4775 | ||
4776 | bsi_tgt = bsi_start (new_bb); | |
4777 | while (!bsi_end_p (bsi)) | |
4778 | { | |
4779 | act = bsi_stmt (bsi); | |
4780 | bsi_remove (&bsi); | |
4781 | bsi_insert_after (&bsi_tgt, act, BSI_NEW_STMT); | |
4782 | } | |
4783 | ||
4784 | return new_bb; | |
4785 | } | |
4786 | ||
4787 | ||
4788 | /* Moves basic block BB after block AFTER. */ | |
4789 | ||
4790 | static bool | |
4791 | tree_move_block_after (basic_block bb, basic_block after) | |
4792 | { | |
4793 | if (bb->prev_bb == after) | |
4794 | return true; | |
4795 | ||
4796 | unlink_block (bb); | |
4797 | link_block (bb, after); | |
4798 | ||
4799 | return true; | |
4800 | } | |
4801 | ||
4802 | ||
4803 | /* Return true if basic_block can be duplicated. */ | |
4804 | ||
4805 | static bool | |
4806 | tree_can_duplicate_bb_p (basic_block bb ATTRIBUTE_UNUSED) | |
4807 | { | |
4808 | return true; | |
4809 | } | |
4810 | ||
6de9cd9a DN |
4811 | /* Create a duplicate of the basic block BB. NOTE: This does not |
4812 | preserve SSA form. */ | |
4813 | ||
4814 | static basic_block | |
4815 | tree_duplicate_bb (basic_block bb) | |
4816 | { | |
4817 | basic_block new_bb; | |
4818 | block_stmt_iterator bsi, bsi_tgt; | |
4c124b4c AM |
4819 | tree phi, val; |
4820 | ssa_op_iter op_iter; | |
6de9cd9a DN |
4821 | |
4822 | new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb); | |
b0382c67 | 4823 | |
42759f1e ZD |
4824 | /* First copy the phi nodes. We do not copy phi node arguments here, |
4825 | since the edges are not ready yet. Keep the chain of phi nodes in | |
4826 | the same order, so that we can add them later. */ | |
bb29d951 | 4827 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
b0382c67 ZD |
4828 | { |
4829 | mark_for_rewrite (PHI_RESULT (phi)); | |
42759f1e | 4830 | create_phi_node (PHI_RESULT (phi), new_bb); |
b0382c67 | 4831 | } |
5ae71719 | 4832 | set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb))); |
b0382c67 | 4833 | |
6de9cd9a DN |
4834 | bsi_tgt = bsi_start (new_bb); |
4835 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
4836 | { | |
4837 | tree stmt = bsi_stmt (bsi); | |
5f240ec4 | 4838 | tree copy; |
6de9cd9a DN |
4839 | |
4840 | if (TREE_CODE (stmt) == LABEL_EXPR) | |
4841 | continue; | |
4842 | ||
b0382c67 ZD |
4843 | /* Record the definitions. */ |
4844 | get_stmt_operands (stmt); | |
4845 | ||
4c124b4c AM |
4846 | FOR_EACH_SSA_TREE_OPERAND (val, stmt, op_iter, SSA_OP_ALL_DEFS) |
4847 | mark_for_rewrite (val); | |
b0382c67 | 4848 | |
5f240ec4 ZD |
4849 | copy = unshare_expr (stmt); |
4850 | ||
4851 | /* Copy also the virtual operands. */ | |
4852 | get_stmt_ann (copy); | |
4853 | copy_virtual_operands (copy, stmt); | |
4854 | ||
4855 | bsi_insert_after (&bsi_tgt, copy, BSI_NEW_STMT); | |
6de9cd9a DN |
4856 | } |
4857 | ||
4858 | return new_bb; | |
4859 | } | |
4860 | ||
42759f1e ZD |
4861 | /* Basic block BB_COPY was created by code duplication. Add phi node |
4862 | arguments for edges going out of BB_COPY. The blocks that were | |
4863 | duplicated have rbi->duplicated set to one. */ | |
4864 | ||
4865 | void | |
4866 | add_phi_args_after_copy_bb (basic_block bb_copy) | |
4867 | { | |
4868 | basic_block bb, dest; | |
4869 | edge e, e_copy; | |
628f6a4e | 4870 | edge_iterator ei; |
42759f1e ZD |
4871 | tree phi, phi_copy, phi_next, def; |
4872 | ||
4873 | bb = bb_copy->rbi->original; | |
4874 | ||
628f6a4e | 4875 | FOR_EACH_EDGE (e_copy, ei, bb_copy->succs) |
42759f1e ZD |
4876 | { |
4877 | if (!phi_nodes (e_copy->dest)) | |
4878 | continue; | |
4879 | ||
4880 | if (e_copy->dest->rbi->duplicated) | |
4881 | dest = e_copy->dest->rbi->original; | |
4882 | else | |
4883 | dest = e_copy->dest; | |
4884 | ||
4885 | e = find_edge (bb, dest); | |
4886 | if (!e) | |
4887 | { | |
4888 | /* During loop unrolling the target of the latch edge is copied. | |
4889 | In this case we are not looking for edge to dest, but to | |
4890 | duplicated block whose original was dest. */ | |
628f6a4e | 4891 | FOR_EACH_EDGE (e, ei, bb->succs) |
42759f1e ZD |
4892 | if (e->dest->rbi->duplicated |
4893 | && e->dest->rbi->original == dest) | |
4894 | break; | |
4895 | ||
4896 | gcc_assert (e != NULL); | |
4897 | } | |
4898 | ||
4899 | for (phi = phi_nodes (e->dest), phi_copy = phi_nodes (e_copy->dest); | |
4900 | phi; | |
eaf0dc02 | 4901 | phi = phi_next, phi_copy = PHI_CHAIN (phi_copy)) |
42759f1e | 4902 | { |
eaf0dc02 | 4903 | phi_next = PHI_CHAIN (phi); |
42759f1e ZD |
4904 | |
4905 | gcc_assert (PHI_RESULT (phi) == PHI_RESULT (phi_copy)); | |
4906 | def = PHI_ARG_DEF_FROM_EDGE (phi, e); | |
d2e398df | 4907 | add_phi_arg (phi_copy, def, e_copy); |
42759f1e ZD |
4908 | } |
4909 | } | |
4910 | } | |
4911 | ||
4912 | /* Blocks in REGION_COPY array of length N_REGION were created by | |
4913 | duplication of basic blocks. Add phi node arguments for edges | |
4914 | going from these blocks. */ | |
4915 | ||
4916 | void | |
4917 | add_phi_args_after_copy (basic_block *region_copy, unsigned n_region) | |
4918 | { | |
4919 | unsigned i; | |
4920 | ||
4921 | for (i = 0; i < n_region; i++) | |
4922 | region_copy[i]->rbi->duplicated = 1; | |
4923 | ||
4924 | for (i = 0; i < n_region; i++) | |
4925 | add_phi_args_after_copy_bb (region_copy[i]); | |
4926 | ||
4927 | for (i = 0; i < n_region; i++) | |
4928 | region_copy[i]->rbi->duplicated = 0; | |
4929 | } | |
4930 | ||
4931 | /* Maps the old ssa name FROM_NAME to TO_NAME. */ | |
4932 | ||
4933 | struct ssa_name_map_entry | |
4934 | { | |
4935 | tree from_name; | |
4936 | tree to_name; | |
4937 | }; | |
4938 | ||
4939 | /* Hash function for ssa_name_map_entry. */ | |
4940 | ||
4941 | static hashval_t | |
4942 | ssa_name_map_entry_hash (const void *entry) | |
4943 | { | |
4944 | const struct ssa_name_map_entry *en = entry; | |
4945 | return SSA_NAME_VERSION (en->from_name); | |
4946 | } | |
4947 | ||
4948 | /* Equality function for ssa_name_map_entry. */ | |
4949 | ||
4950 | static int | |
4951 | ssa_name_map_entry_eq (const void *in_table, const void *ssa_name) | |
4952 | { | |
4953 | const struct ssa_name_map_entry *en = in_table; | |
4954 | ||
4955 | return en->from_name == ssa_name; | |
4956 | } | |
4957 | ||
4958 | /* Allocate duplicates of ssa names in list DEFINITIONS and store the mapping | |
4959 | to MAP. */ | |
4960 | ||
4961 | void | |
4962 | allocate_ssa_names (bitmap definitions, htab_t *map) | |
4963 | { | |
4964 | tree name; | |
4965 | struct ssa_name_map_entry *entry; | |
4966 | PTR *slot; | |
4967 | unsigned ver; | |
87c476a2 | 4968 | bitmap_iterator bi; |
42759f1e ZD |
4969 | |
4970 | if (!*map) | |
4971 | *map = htab_create (10, ssa_name_map_entry_hash, | |
4972 | ssa_name_map_entry_eq, free); | |
87c476a2 | 4973 | EXECUTE_IF_SET_IN_BITMAP (definitions, 0, ver, bi) |
42759f1e ZD |
4974 | { |
4975 | name = ssa_name (ver); | |
4976 | slot = htab_find_slot_with_hash (*map, name, SSA_NAME_VERSION (name), | |
4977 | INSERT); | |
4978 | if (*slot) | |
4979 | entry = *slot; | |
4980 | else | |
4981 | { | |
4982 | entry = xmalloc (sizeof (struct ssa_name_map_entry)); | |
4983 | entry->from_name = name; | |
4984 | *slot = entry; | |
4985 | } | |
4986 | entry->to_name = duplicate_ssa_name (name, SSA_NAME_DEF_STMT (name)); | |
87c476a2 | 4987 | } |
42759f1e ZD |
4988 | } |
4989 | ||
4990 | /* Rewrite the definition DEF in statement STMT to new ssa name as specified | |
4991 | by the mapping MAP. */ | |
4992 | ||
4993 | static void | |
4994 | rewrite_to_new_ssa_names_def (def_operand_p def, tree stmt, htab_t map) | |
4995 | { | |
4996 | tree name = DEF_FROM_PTR (def); | |
4997 | struct ssa_name_map_entry *entry; | |
4998 | ||
4999 | gcc_assert (TREE_CODE (name) == SSA_NAME); | |
5000 | ||
5001 | entry = htab_find_with_hash (map, name, SSA_NAME_VERSION (name)); | |
5002 | if (!entry) | |
5003 | return; | |
5004 | ||
5005 | SET_DEF (def, entry->to_name); | |
5006 | SSA_NAME_DEF_STMT (entry->to_name) = stmt; | |
5007 | } | |
5008 | ||
5009 | /* Rewrite the USE to new ssa name as specified by the mapping MAP. */ | |
5010 | ||
5011 | static void | |
5012 | rewrite_to_new_ssa_names_use (use_operand_p use, htab_t map) | |
5013 | { | |
5014 | tree name = USE_FROM_PTR (use); | |
5015 | struct ssa_name_map_entry *entry; | |
5016 | ||
5017 | if (TREE_CODE (name) != SSA_NAME) | |
5018 | return; | |
5019 | ||
5020 | entry = htab_find_with_hash (map, name, SSA_NAME_VERSION (name)); | |
5021 | if (!entry) | |
5022 | return; | |
5023 | ||
5024 | SET_USE (use, entry->to_name); | |
5025 | } | |
5026 | ||
5027 | /* Rewrite the ssa names in basic block BB to new ones as specified by the | |
5028 | mapping MAP. */ | |
5029 | ||
5030 | void | |
5031 | rewrite_to_new_ssa_names_bb (basic_block bb, htab_t map) | |
5032 | { | |
5033 | unsigned i; | |
5034 | edge e; | |
628f6a4e | 5035 | edge_iterator ei; |
42759f1e ZD |
5036 | tree phi, stmt; |
5037 | block_stmt_iterator bsi; | |
5038 | use_optype uses; | |
5039 | vuse_optype vuses; | |
5040 | def_optype defs; | |
5041 | v_may_def_optype v_may_defs; | |
5042 | v_must_def_optype v_must_defs; | |
5043 | stmt_ann_t ann; | |
5044 | ||
628f6a4e | 5045 | FOR_EACH_EDGE (e, ei, bb->preds) |
42759f1e ZD |
5046 | if (e->flags & EDGE_ABNORMAL) |
5047 | break; | |
5048 | ||
bb29d951 | 5049 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
42759f1e ZD |
5050 | { |
5051 | rewrite_to_new_ssa_names_def (PHI_RESULT_PTR (phi), phi, map); | |
5052 | if (e) | |
5053 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi)) = 1; | |
5054 | } | |
5055 | ||
5056 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
5057 | { | |
5058 | stmt = bsi_stmt (bsi); | |
5059 | get_stmt_operands (stmt); | |
5060 | ann = stmt_ann (stmt); | |
5061 | ||
5062 | uses = USE_OPS (ann); | |
5063 | for (i = 0; i < NUM_USES (uses); i++) | |
5064 | rewrite_to_new_ssa_names_use (USE_OP_PTR (uses, i), map); | |
5065 | ||
5066 | defs = DEF_OPS (ann); | |
5067 | for (i = 0; i < NUM_DEFS (defs); i++) | |
5068 | rewrite_to_new_ssa_names_def (DEF_OP_PTR (defs, i), stmt, map); | |
5069 | ||
5070 | vuses = VUSE_OPS (ann); | |
5071 | for (i = 0; i < NUM_VUSES (vuses); i++) | |
5072 | rewrite_to_new_ssa_names_use (VUSE_OP_PTR (vuses, i), map); | |
5073 | ||
5074 | v_may_defs = V_MAY_DEF_OPS (ann); | |
5075 | for (i = 0; i < NUM_V_MAY_DEFS (v_may_defs); i++) | |
5076 | { | |
5077 | rewrite_to_new_ssa_names_use | |
5078 | (V_MAY_DEF_OP_PTR (v_may_defs, i), map); | |
5079 | rewrite_to_new_ssa_names_def | |
5080 | (V_MAY_DEF_RESULT_PTR (v_may_defs, i), stmt, map); | |
5081 | } | |
5082 | ||
5083 | v_must_defs = V_MUST_DEF_OPS (ann); | |
5084 | for (i = 0; i < NUM_V_MUST_DEFS (v_must_defs); i++) | |
52328bf6 DB |
5085 | { |
5086 | rewrite_to_new_ssa_names_def | |
5087 | (V_MUST_DEF_RESULT_PTR (v_must_defs, i), stmt, map); | |
5088 | rewrite_to_new_ssa_names_use | |
5089 | (V_MUST_DEF_KILL_PTR (v_must_defs, i), map); | |
5090 | } | |
42759f1e ZD |
5091 | } |
5092 | ||
628f6a4e | 5093 | FOR_EACH_EDGE (e, ei, bb->succs) |
bb29d951 | 5094 | for (phi = phi_nodes (e->dest); phi; phi = PHI_CHAIN (phi)) |
42759f1e ZD |
5095 | { |
5096 | rewrite_to_new_ssa_names_use | |
5097 | (PHI_ARG_DEF_PTR_FROM_EDGE (phi, e), map); | |
5098 | ||
5099 | if (e->flags & EDGE_ABNORMAL) | |
5100 | { | |
5101 | tree op = PHI_ARG_DEF_FROM_EDGE (phi, e); | |
5102 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op) = 1; | |
5103 | } | |
5104 | } | |
5105 | } | |
5106 | ||
5107 | /* Rewrite the ssa names in N_REGION blocks REGION to the new ones as specified | |
5108 | by the mapping MAP. */ | |
5109 | ||
5110 | void | |
5111 | rewrite_to_new_ssa_names (basic_block *region, unsigned n_region, htab_t map) | |
5112 | { | |
5113 | unsigned r; | |
5114 | ||
5115 | for (r = 0; r < n_region; r++) | |
5116 | rewrite_to_new_ssa_names_bb (region[r], map); | |
5117 | } | |
5118 | ||
5119 | /* Duplicates a REGION (set of N_REGION basic blocks) with just a single | |
5120 | important exit edge EXIT. By important we mean that no SSA name defined | |
5121 | inside region is live over the other exit edges of the region. All entry | |
5122 | edges to the region must go to ENTRY->dest. The edge ENTRY is redirected | |
5123 | to the duplicate of the region. SSA form, dominance and loop information | |
5124 | is updated. The new basic blocks are stored to REGION_COPY in the same | |
5125 | order as they had in REGION, provided that REGION_COPY is not NULL. | |
5126 | The function returns false if it is unable to copy the region, | |
5127 | true otherwise. */ | |
5128 | ||
5129 | bool | |
5130 | tree_duplicate_sese_region (edge entry, edge exit, | |
5131 | basic_block *region, unsigned n_region, | |
5132 | basic_block *region_copy) | |
5133 | { | |
5134 | unsigned i, n_doms, ver; | |
5135 | bool free_region_copy = false, copying_header = false; | |
5136 | struct loop *loop = entry->dest->loop_father; | |
5137 | edge exit_copy; | |
5138 | bitmap definitions; | |
71882046 | 5139 | tree phi; |
42759f1e ZD |
5140 | basic_block *doms; |
5141 | htab_t ssa_name_map = NULL; | |
5142 | edge redirected; | |
87c476a2 | 5143 | bitmap_iterator bi; |
42759f1e ZD |
5144 | |
5145 | if (!can_copy_bbs_p (region, n_region)) | |
5146 | return false; | |
5147 | ||
5148 | /* Some sanity checking. Note that we do not check for all possible | |
5149 | missuses of the functions. I.e. if you ask to copy something weird, | |
5150 | it will work, but the state of structures probably will not be | |
5151 | correct. */ | |
5152 | ||
5153 | for (i = 0; i < n_region; i++) | |
5154 | { | |
5155 | /* We do not handle subloops, i.e. all the blocks must belong to the | |
5156 | same loop. */ | |
5157 | if (region[i]->loop_father != loop) | |
5158 | return false; | |
5159 | ||
5160 | if (region[i] != entry->dest | |
5161 | && region[i] == loop->header) | |
5162 | return false; | |
5163 | } | |
5164 | ||
5165 | loop->copy = loop; | |
5166 | ||
5167 | /* In case the function is used for loop header copying (which is the primary | |
5168 | use), ensure that EXIT and its copy will be new latch and entry edges. */ | |
5169 | if (loop->header == entry->dest) | |
5170 | { | |
5171 | copying_header = true; | |
5172 | loop->copy = loop->outer; | |
5173 | ||
5174 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src)) | |
5175 | return false; | |
5176 | ||
5177 | for (i = 0; i < n_region; i++) | |
5178 | if (region[i] != exit->src | |
5179 | && dominated_by_p (CDI_DOMINATORS, region[i], exit->src)) | |
5180 | return false; | |
5181 | } | |
5182 | ||
5183 | if (!region_copy) | |
5184 | { | |
5185 | region_copy = xmalloc (sizeof (basic_block) * n_region); | |
5186 | free_region_copy = true; | |
5187 | } | |
5188 | ||
5189 | gcc_assert (!any_marked_for_rewrite_p ()); | |
5190 | ||
5191 | /* Record blocks outside the region that are duplicated by something | |
5192 | inside. */ | |
5193 | doms = xmalloc (sizeof (basic_block) * n_basic_blocks); | |
5194 | n_doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region, doms); | |
5195 | ||
5196 | copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop); | |
5197 | definitions = marked_ssa_names (); | |
5198 | ||
5199 | if (copying_header) | |
5200 | { | |
5201 | loop->header = exit->dest; | |
5202 | loop->latch = exit->src; | |
5203 | } | |
5204 | ||
5205 | /* Redirect the entry and add the phi node arguments. */ | |
5206 | redirected = redirect_edge_and_branch (entry, entry->dest->rbi->copy); | |
5207 | gcc_assert (redirected != NULL); | |
71882046 | 5208 | flush_pending_stmts (entry); |
42759f1e ZD |
5209 | |
5210 | /* Concerning updating of dominators: We must recount dominators | |
5211 | for entry block and its copy. Anything that is outside of the region, but | |
5212 | was dominated by something inside needs recounting as well. */ | |
5213 | set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src); | |
5214 | doms[n_doms++] = entry->dest->rbi->original; | |
5215 | iterate_fix_dominators (CDI_DOMINATORS, doms, n_doms); | |
5216 | free (doms); | |
5217 | ||
5218 | /* Add the other phi node arguments. */ | |
5219 | add_phi_args_after_copy (region_copy, n_region); | |
5220 | ||
5221 | /* Add phi nodes for definitions at exit. TODO -- once we have immediate | |
5222 | uses, it should be possible to emit phi nodes just for definitions that | |
5223 | are used outside region. */ | |
87c476a2 | 5224 | EXECUTE_IF_SET_IN_BITMAP (definitions, 0, ver, bi) |
42759f1e ZD |
5225 | { |
5226 | tree name = ssa_name (ver); | |
5227 | ||
5228 | phi = create_phi_node (name, exit->dest); | |
d2e398df KH |
5229 | add_phi_arg (phi, name, exit); |
5230 | add_phi_arg (phi, name, exit_copy); | |
42759f1e ZD |
5231 | |
5232 | SSA_NAME_DEF_STMT (name) = phi; | |
87c476a2 | 5233 | } |
42759f1e ZD |
5234 | |
5235 | /* And create new definitions inside region and its copy. TODO -- once we | |
5236 | have immediate uses, it might be better to leave definitions in region | |
5237 | unchanged, create new ssa names for phi nodes on exit, and rewrite | |
5238 | the uses, to avoid changing the copied region. */ | |
5239 | allocate_ssa_names (definitions, &ssa_name_map); | |
5240 | rewrite_to_new_ssa_names (region, n_region, ssa_name_map); | |
5241 | allocate_ssa_names (definitions, &ssa_name_map); | |
5242 | rewrite_to_new_ssa_names (region_copy, n_region, ssa_name_map); | |
5243 | htab_delete (ssa_name_map); | |
5244 | ||
5245 | if (free_region_copy) | |
5246 | free (region_copy); | |
5247 | ||
5248 | unmark_all_for_rewrite (); | |
8bdbfff5 | 5249 | BITMAP_FREE (definitions); |
42759f1e ZD |
5250 | |
5251 | return true; | |
5252 | } | |
6de9cd9a DN |
5253 | |
5254 | /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */ | |
5255 | ||
5256 | void | |
5257 | dump_function_to_file (tree fn, FILE *file, int flags) | |
5258 | { | |
5259 | tree arg, vars, var; | |
5260 | bool ignore_topmost_bind = false, any_var = false; | |
5261 | basic_block bb; | |
5262 | tree chain; | |
5263 | ||
673fda6b | 5264 | fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2)); |
6de9cd9a DN |
5265 | |
5266 | arg = DECL_ARGUMENTS (fn); | |
5267 | while (arg) | |
5268 | { | |
5269 | print_generic_expr (file, arg, dump_flags); | |
5270 | if (TREE_CHAIN (arg)) | |
5271 | fprintf (file, ", "); | |
5272 | arg = TREE_CHAIN (arg); | |
5273 | } | |
5274 | fprintf (file, ")\n"); | |
5275 | ||
5276 | if (flags & TDF_RAW) | |
5277 | { | |
5278 | dump_node (fn, TDF_SLIM | flags, file); | |
5279 | return; | |
5280 | } | |
5281 | ||
5282 | /* When GIMPLE is lowered, the variables are no longer available in | |
5283 | BIND_EXPRs, so display them separately. */ | |
5284 | if (cfun && cfun->unexpanded_var_list) | |
5285 | { | |
5286 | ignore_topmost_bind = true; | |
5287 | ||
5288 | fprintf (file, "{\n"); | |
5289 | for (vars = cfun->unexpanded_var_list; vars; vars = TREE_CHAIN (vars)) | |
5290 | { | |
5291 | var = TREE_VALUE (vars); | |
5292 | ||
5293 | print_generic_decl (file, var, flags); | |
5294 | fprintf (file, "\n"); | |
5295 | ||
5296 | any_var = true; | |
5297 | } | |
5298 | } | |
5299 | ||
5300 | if (basic_block_info) | |
5301 | { | |
5302 | /* Make a CFG based dump. */ | |
878f99d2 | 5303 | check_bb_profile (ENTRY_BLOCK_PTR, file); |
6de9cd9a DN |
5304 | if (!ignore_topmost_bind) |
5305 | fprintf (file, "{\n"); | |
5306 | ||
5307 | if (any_var && n_basic_blocks) | |
5308 | fprintf (file, "\n"); | |
5309 | ||
5310 | FOR_EACH_BB (bb) | |
5311 | dump_generic_bb (file, bb, 2, flags); | |
5312 | ||
5313 | fprintf (file, "}\n"); | |
878f99d2 | 5314 | check_bb_profile (EXIT_BLOCK_PTR, file); |
6de9cd9a DN |
5315 | } |
5316 | else | |
5317 | { | |
5318 | int indent; | |
5319 | ||
5320 | /* Make a tree based dump. */ | |
5321 | chain = DECL_SAVED_TREE (fn); | |
5322 | ||
5323 | if (TREE_CODE (chain) == BIND_EXPR) | |
5324 | { | |
5325 | if (ignore_topmost_bind) | |
5326 | { | |
5327 | chain = BIND_EXPR_BODY (chain); | |
5328 | indent = 2; | |
5329 | } | |
5330 | else | |
5331 | indent = 0; | |
5332 | } | |
5333 | else | |
5334 | { | |
5335 | if (!ignore_topmost_bind) | |
5336 | fprintf (file, "{\n"); | |
5337 | indent = 2; | |
5338 | } | |
5339 | ||
5340 | if (any_var) | |
5341 | fprintf (file, "\n"); | |
5342 | ||
5343 | print_generic_stmt_indented (file, chain, flags, indent); | |
5344 | if (ignore_topmost_bind) | |
5345 | fprintf (file, "}\n"); | |
5346 | } | |
5347 | ||
5348 | fprintf (file, "\n\n"); | |
5349 | } | |
5350 | ||
5351 | ||
5352 | /* Pretty print of the loops intermediate representation. */ | |
5353 | static void print_loop (FILE *, struct loop *, int); | |
628f6a4e BE |
5354 | static void print_pred_bbs (FILE *, basic_block bb); |
5355 | static void print_succ_bbs (FILE *, basic_block bb); | |
6de9cd9a DN |
5356 | |
5357 | ||
5358 | /* Print the predecessors indexes of edge E on FILE. */ | |
5359 | ||
5360 | static void | |
628f6a4e | 5361 | print_pred_bbs (FILE *file, basic_block bb) |
6de9cd9a | 5362 | { |
628f6a4e BE |
5363 | edge e; |
5364 | edge_iterator ei; | |
5365 | ||
5366 | FOR_EACH_EDGE (e, ei, bb->preds) | |
6de9cd9a | 5367 | fprintf (file, "bb_%d", e->src->index); |
6de9cd9a DN |
5368 | } |
5369 | ||
5370 | ||
5371 | /* Print the successors indexes of edge E on FILE. */ | |
5372 | ||
5373 | static void | |
628f6a4e | 5374 | print_succ_bbs (FILE *file, basic_block bb) |
6de9cd9a | 5375 | { |
628f6a4e BE |
5376 | edge e; |
5377 | edge_iterator ei; | |
5378 | ||
5379 | FOR_EACH_EDGE (e, ei, bb->succs) | |
5380 | fprintf (file, "bb_%d", e->src->index); | |
6de9cd9a DN |
5381 | } |
5382 | ||
5383 | ||
5384 | /* Pretty print LOOP on FILE, indented INDENT spaces. */ | |
5385 | ||
5386 | static void | |
5387 | print_loop (FILE *file, struct loop *loop, int indent) | |
5388 | { | |
5389 | char *s_indent; | |
5390 | basic_block bb; | |
5391 | ||
5392 | if (loop == NULL) | |
5393 | return; | |
5394 | ||
5395 | s_indent = (char *) alloca ((size_t) indent + 1); | |
5396 | memset ((void *) s_indent, ' ', (size_t) indent); | |
5397 | s_indent[indent] = '\0'; | |
5398 | ||
5399 | /* Print the loop's header. */ | |
5400 | fprintf (file, "%sloop_%d\n", s_indent, loop->num); | |
5401 | ||
5402 | /* Print the loop's body. */ | |
5403 | fprintf (file, "%s{\n", s_indent); | |
5404 | FOR_EACH_BB (bb) | |
5405 | if (bb->loop_father == loop) | |
5406 | { | |
5407 | /* Print the basic_block's header. */ | |
5408 | fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index); | |
628f6a4e | 5409 | print_pred_bbs (file, bb); |
6de9cd9a | 5410 | fprintf (file, "}, succs = {"); |
628f6a4e | 5411 | print_succ_bbs (file, bb); |
6de9cd9a DN |
5412 | fprintf (file, "})\n"); |
5413 | ||
5414 | /* Print the basic_block's body. */ | |
5415 | fprintf (file, "%s {\n", s_indent); | |
5416 | tree_dump_bb (bb, file, indent + 4); | |
5417 | fprintf (file, "%s }\n", s_indent); | |
5418 | } | |
5419 | ||
5420 | print_loop (file, loop->inner, indent + 2); | |
5421 | fprintf (file, "%s}\n", s_indent); | |
5422 | print_loop (file, loop->next, indent); | |
5423 | } | |
5424 | ||
5425 | ||
5426 | /* Follow a CFG edge from the entry point of the program, and on entry | |
5427 | of a loop, pretty print the loop structure on FILE. */ | |
5428 | ||
5429 | void | |
5430 | print_loop_ir (FILE *file) | |
5431 | { | |
5432 | basic_block bb; | |
5433 | ||
5434 | bb = BASIC_BLOCK (0); | |
5435 | if (bb && bb->loop_father) | |
5436 | print_loop (file, bb->loop_father, 0); | |
5437 | } | |
5438 | ||
5439 | ||
5440 | /* Debugging loops structure at tree level. */ | |
5441 | ||
5442 | void | |
5443 | debug_loop_ir (void) | |
5444 | { | |
5445 | print_loop_ir (stderr); | |
5446 | } | |
5447 | ||
5448 | ||
5449 | /* Return true if BB ends with a call, possibly followed by some | |
5450 | instructions that must stay with the call. Return false, | |
5451 | otherwise. */ | |
5452 | ||
5453 | static bool | |
5454 | tree_block_ends_with_call_p (basic_block bb) | |
5455 | { | |
5456 | block_stmt_iterator bsi = bsi_last (bb); | |
cd709752 | 5457 | return get_call_expr_in (bsi_stmt (bsi)) != NULL; |
6de9cd9a DN |
5458 | } |
5459 | ||
5460 | ||
5461 | /* Return true if BB ends with a conditional branch. Return false, | |
5462 | otherwise. */ | |
5463 | ||
5464 | static bool | |
5465 | tree_block_ends_with_condjump_p (basic_block bb) | |
5466 | { | |
5467 | tree stmt = tsi_stmt (bsi_last (bb).tsi); | |
5468 | return (TREE_CODE (stmt) == COND_EXPR); | |
5469 | } | |
5470 | ||
5471 | ||
5472 | /* Return true if we need to add fake edge to exit at statement T. | |
5473 | Helper function for tree_flow_call_edges_add. */ | |
5474 | ||
5475 | static bool | |
5476 | need_fake_edge_p (tree t) | |
5477 | { | |
cd709752 | 5478 | tree call; |
6de9cd9a DN |
5479 | |
5480 | /* NORETURN and LONGJMP calls already have an edge to exit. | |
321cf1f2 | 5481 | CONST and PURE calls do not need one. |
6de9cd9a DN |
5482 | We don't currently check for CONST and PURE here, although |
5483 | it would be a good idea, because those attributes are | |
5484 | figured out from the RTL in mark_constant_function, and | |
5485 | the counter incrementation code from -fprofile-arcs | |
5486 | leads to different results from -fbranch-probabilities. */ | |
cd709752 RH |
5487 | call = get_call_expr_in (t); |
5488 | if (call | |
321cf1f2 | 5489 | && !(call_expr_flags (call) & ECF_NORETURN)) |
6de9cd9a DN |
5490 | return true; |
5491 | ||
5492 | if (TREE_CODE (t) == ASM_EXPR | |
5493 | && (ASM_VOLATILE_P (t) || ASM_INPUT_P (t))) | |
5494 | return true; | |
5495 | ||
5496 | return false; | |
5497 | } | |
5498 | ||
5499 | ||
5500 | /* Add fake edges to the function exit for any non constant and non | |
5501 | noreturn calls, volatile inline assembly in the bitmap of blocks | |
5502 | specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return | |
5503 | the number of blocks that were split. | |
5504 | ||
5505 | The goal is to expose cases in which entering a basic block does | |
5506 | not imply that all subsequent instructions must be executed. */ | |
5507 | ||
5508 | static int | |
5509 | tree_flow_call_edges_add (sbitmap blocks) | |
5510 | { | |
5511 | int i; | |
5512 | int blocks_split = 0; | |
5513 | int last_bb = last_basic_block; | |
5514 | bool check_last_block = false; | |
5515 | ||
5516 | if (n_basic_blocks == 0) | |
5517 | return 0; | |
5518 | ||
5519 | if (! blocks) | |
5520 | check_last_block = true; | |
5521 | else | |
5522 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
5523 | ||
5524 | /* In the last basic block, before epilogue generation, there will be | |
5525 | a fallthru edge to EXIT. Special care is required if the last insn | |
5526 | of the last basic block is a call because make_edge folds duplicate | |
5527 | edges, which would result in the fallthru edge also being marked | |
5528 | fake, which would result in the fallthru edge being removed by | |
5529 | remove_fake_edges, which would result in an invalid CFG. | |
5530 | ||
5531 | Moreover, we can't elide the outgoing fake edge, since the block | |
5532 | profiler needs to take this into account in order to solve the minimal | |
5533 | spanning tree in the case that the call doesn't return. | |
5534 | ||
5535 | Handle this by adding a dummy instruction in a new last basic block. */ | |
5536 | if (check_last_block) | |
5537 | { | |
5538 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
5539 | block_stmt_iterator bsi = bsi_last (bb); | |
5540 | tree t = NULL_TREE; | |
5541 | if (!bsi_end_p (bsi)) | |
5542 | t = bsi_stmt (bsi); | |
5543 | ||
5544 | if (need_fake_edge_p (t)) | |
5545 | { | |
5546 | edge e; | |
5547 | ||
9ff3d2de JL |
5548 | e = find_edge (bb, EXIT_BLOCK_PTR); |
5549 | if (e) | |
5550 | { | |
5551 | bsi_insert_on_edge (e, build_empty_stmt ()); | |
5552 | bsi_commit_edge_inserts (); | |
5553 | } | |
6de9cd9a DN |
5554 | } |
5555 | } | |
5556 | ||
5557 | /* Now add fake edges to the function exit for any non constant | |
5558 | calls since there is no way that we can determine if they will | |
5559 | return or not... */ | |
5560 | for (i = 0; i < last_bb; i++) | |
5561 | { | |
5562 | basic_block bb = BASIC_BLOCK (i); | |
5563 | block_stmt_iterator bsi; | |
5564 | tree stmt, last_stmt; | |
5565 | ||
5566 | if (!bb) | |
5567 | continue; | |
5568 | ||
5569 | if (blocks && !TEST_BIT (blocks, i)) | |
5570 | continue; | |
5571 | ||
5572 | bsi = bsi_last (bb); | |
5573 | if (!bsi_end_p (bsi)) | |
5574 | { | |
5575 | last_stmt = bsi_stmt (bsi); | |
5576 | do | |
5577 | { | |
5578 | stmt = bsi_stmt (bsi); | |
5579 | if (need_fake_edge_p (stmt)) | |
5580 | { | |
5581 | edge e; | |
5582 | /* The handling above of the final block before the | |
5583 | epilogue should be enough to verify that there is | |
5584 | no edge to the exit block in CFG already. | |
5585 | Calling make_edge in such case would cause us to | |
5586 | mark that edge as fake and remove it later. */ | |
5587 | #ifdef ENABLE_CHECKING | |
5588 | if (stmt == last_stmt) | |
628f6a4e | 5589 | { |
9ff3d2de JL |
5590 | e = find_edge (bb, EXIT_BLOCK_PTR); |
5591 | gcc_assert (e == NULL); | |
628f6a4e | 5592 | } |
6de9cd9a DN |
5593 | #endif |
5594 | ||
5595 | /* Note that the following may create a new basic block | |
5596 | and renumber the existing basic blocks. */ | |
5597 | if (stmt != last_stmt) | |
5598 | { | |
5599 | e = split_block (bb, stmt); | |
5600 | if (e) | |
5601 | blocks_split++; | |
5602 | } | |
5603 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
5604 | } | |
5605 | bsi_prev (&bsi); | |
5606 | } | |
5607 | while (!bsi_end_p (bsi)); | |
5608 | } | |
5609 | } | |
5610 | ||
5611 | if (blocks_split) | |
5612 | verify_flow_info (); | |
5613 | ||
5614 | return blocks_split; | |
5615 | } | |
5616 | ||
1eaba2f2 RH |
5617 | bool |
5618 | tree_purge_dead_eh_edges (basic_block bb) | |
5619 | { | |
5620 | bool changed = false; | |
628f6a4e BE |
5621 | edge e; |
5622 | edge_iterator ei; | |
1eaba2f2 RH |
5623 | tree stmt = last_stmt (bb); |
5624 | ||
5625 | if (stmt && tree_can_throw_internal (stmt)) | |
5626 | return false; | |
5627 | ||
628f6a4e | 5628 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
1eaba2f2 | 5629 | { |
1eaba2f2 RH |
5630 | if (e->flags & EDGE_EH) |
5631 | { | |
d0d2cc21 | 5632 | remove_edge (e); |
1eaba2f2 RH |
5633 | changed = true; |
5634 | } | |
628f6a4e BE |
5635 | else |
5636 | ei_next (&ei); | |
1eaba2f2 RH |
5637 | } |
5638 | ||
69d49802 JJ |
5639 | /* Removal of dead EH edges might change dominators of not |
5640 | just immediate successors. E.g. when bb1 is changed so that | |
5641 | it no longer can throw and bb1->bb3 and bb1->bb4 are dead | |
5642 | eh edges purged by this function in: | |
5643 | 0 | |
5644 | / \ | |
5645 | v v | |
5646 | 1-->2 | |
5647 | / \ | | |
5648 | v v | | |
5649 | 3-->4 | | |
5650 | \ v | |
5651 | --->5 | |
5652 | | | |
5653 | - | |
5654 | idom(bb5) must be recomputed. For now just free the dominance | |
5655 | info. */ | |
5656 | if (changed) | |
5657 | free_dominance_info (CDI_DOMINATORS); | |
5658 | ||
1eaba2f2 RH |
5659 | return changed; |
5660 | } | |
5661 | ||
5662 | bool | |
5663 | tree_purge_all_dead_eh_edges (bitmap blocks) | |
5664 | { | |
5665 | bool changed = false; | |
3cd8c58a | 5666 | unsigned i; |
87c476a2 | 5667 | bitmap_iterator bi; |
1eaba2f2 | 5668 | |
87c476a2 ZD |
5669 | EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi) |
5670 | { | |
5671 | changed |= tree_purge_dead_eh_edges (BASIC_BLOCK (i)); | |
5672 | } | |
1eaba2f2 RH |
5673 | |
5674 | return changed; | |
5675 | } | |
6de9cd9a | 5676 | |
a100ac1e KH |
5677 | /* This function is called whenever a new edge is created or |
5678 | redirected. */ | |
5679 | ||
5680 | static void | |
5681 | tree_execute_on_growing_pred (edge e) | |
5682 | { | |
5683 | basic_block bb = e->dest; | |
5684 | ||
5685 | if (phi_nodes (bb)) | |
5686 | reserve_phi_args_for_new_edge (bb); | |
5687 | } | |
5688 | ||
e51546f8 KH |
5689 | /* This function is called immediately before edge E is removed from |
5690 | the edge vector E->dest->preds. */ | |
5691 | ||
5692 | static void | |
5693 | tree_execute_on_shrinking_pred (edge e) | |
5694 | { | |
5695 | if (phi_nodes (e->dest)) | |
5696 | remove_phi_args (e); | |
5697 | } | |
5698 | ||
6de9cd9a DN |
5699 | struct cfg_hooks tree_cfg_hooks = { |
5700 | "tree", | |
5701 | tree_verify_flow_info, | |
5702 | tree_dump_bb, /* dump_bb */ | |
5703 | create_bb, /* create_basic_block */ | |
5704 | tree_redirect_edge_and_branch,/* redirect_edge_and_branch */ | |
5705 | tree_redirect_edge_and_branch_force,/* redirect_edge_and_branch_force */ | |
5706 | remove_bb, /* delete_basic_block */ | |
5707 | tree_split_block, /* split_block */ | |
5708 | tree_move_block_after, /* move_block_after */ | |
5709 | tree_can_merge_blocks_p, /* can_merge_blocks_p */ | |
5710 | tree_merge_blocks, /* merge_blocks */ | |
5711 | tree_predict_edge, /* predict_edge */ | |
5712 | tree_predicted_by_p, /* predicted_by_p */ | |
5713 | tree_can_duplicate_bb_p, /* can_duplicate_block_p */ | |
5714 | tree_duplicate_bb, /* duplicate_block */ | |
5715 | tree_split_edge, /* split_edge */ | |
5716 | tree_make_forwarder_block, /* make_forward_block */ | |
5717 | NULL, /* tidy_fallthru_edge */ | |
5718 | tree_block_ends_with_call_p, /* block_ends_with_call_p */ | |
5719 | tree_block_ends_with_condjump_p, /* block_ends_with_condjump_p */ | |
d9d4706f | 5720 | tree_flow_call_edges_add, /* flow_call_edges_add */ |
a100ac1e | 5721 | tree_execute_on_growing_pred, /* execute_on_growing_pred */ |
e51546f8 | 5722 | tree_execute_on_shrinking_pred, /* execute_on_shrinking_pred */ |
6de9cd9a DN |
5723 | }; |
5724 | ||
5725 | ||
5726 | /* Split all critical edges. */ | |
5727 | ||
5728 | static void | |
5729 | split_critical_edges (void) | |
5730 | { | |
5731 | basic_block bb; | |
5732 | edge e; | |
628f6a4e | 5733 | edge_iterator ei; |
6de9cd9a | 5734 | |
d6be0d7f JL |
5735 | /* split_edge can redirect edges out of SWITCH_EXPRs, which can get |
5736 | expensive. So we want to enable recording of edge to CASE_LABEL_EXPR | |
5737 | mappings around the calls to split_edge. */ | |
5738 | start_recording_case_labels (); | |
6de9cd9a DN |
5739 | FOR_ALL_BB (bb) |
5740 | { | |
628f6a4e | 5741 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
5742 | if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL)) |
5743 | { | |
5744 | split_edge (e); | |
5745 | } | |
5746 | } | |
d6be0d7f | 5747 | end_recording_case_labels (); |
6de9cd9a DN |
5748 | } |
5749 | ||
5750 | struct tree_opt_pass pass_split_crit_edges = | |
5751 | { | |
5d44aeed | 5752 | "crited", /* name */ |
6de9cd9a DN |
5753 | NULL, /* gate */ |
5754 | split_critical_edges, /* execute */ | |
5755 | NULL, /* sub */ | |
5756 | NULL, /* next */ | |
5757 | 0, /* static_pass_number */ | |
5758 | TV_TREE_SPLIT_EDGES, /* tv_id */ | |
5759 | PROP_cfg, /* properties required */ | |
5760 | PROP_no_crit_edges, /* properties_provided */ | |
5761 | 0, /* properties_destroyed */ | |
5762 | 0, /* todo_flags_start */ | |
9f8628ba PB |
5763 | TODO_dump_func, /* todo_flags_finish */ |
5764 | 0 /* letter */ | |
6de9cd9a | 5765 | }; |
26277d41 PB |
5766 | |
5767 | \f | |
5768 | /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into | |
5769 | a temporary, make sure and register it to be renamed if necessary, | |
5770 | and finally return the temporary. Put the statements to compute | |
5771 | EXP before the current statement in BSI. */ | |
5772 | ||
5773 | tree | |
5774 | gimplify_val (block_stmt_iterator *bsi, tree type, tree exp) | |
5775 | { | |
5776 | tree t, new_stmt, orig_stmt; | |
5777 | ||
5778 | if (is_gimple_val (exp)) | |
5779 | return exp; | |
5780 | ||
5781 | t = make_rename_temp (type, NULL); | |
5782 | new_stmt = build (MODIFY_EXPR, type, t, exp); | |
5783 | ||
5784 | orig_stmt = bsi_stmt (*bsi); | |
5785 | SET_EXPR_LOCUS (new_stmt, EXPR_LOCUS (orig_stmt)); | |
5786 | TREE_BLOCK (new_stmt) = TREE_BLOCK (orig_stmt); | |
5787 | ||
5788 | bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT); | |
5789 | ||
5790 | return t; | |
5791 | } | |
5792 | ||
5793 | /* Build a ternary operation and gimplify it. Emit code before BSI. | |
5794 | Return the gimple_val holding the result. */ | |
5795 | ||
5796 | tree | |
5797 | gimplify_build3 (block_stmt_iterator *bsi, enum tree_code code, | |
5798 | tree type, tree a, tree b, tree c) | |
5799 | { | |
5800 | tree ret; | |
5801 | ||
5802 | ret = fold (build3 (code, type, a, b, c)); | |
5803 | STRIP_NOPS (ret); | |
5804 | ||
5805 | return gimplify_val (bsi, type, ret); | |
5806 | } | |
5807 | ||
5808 | /* Build a binary operation and gimplify it. Emit code before BSI. | |
5809 | Return the gimple_val holding the result. */ | |
5810 | ||
5811 | tree | |
5812 | gimplify_build2 (block_stmt_iterator *bsi, enum tree_code code, | |
5813 | tree type, tree a, tree b) | |
5814 | { | |
5815 | tree ret; | |
5816 | ||
5817 | ret = fold (build2 (code, type, a, b)); | |
5818 | STRIP_NOPS (ret); | |
5819 | ||
5820 | return gimplify_val (bsi, type, ret); | |
5821 | } | |
5822 | ||
5823 | /* Build a unary operation and gimplify it. Emit code before BSI. | |
5824 | Return the gimple_val holding the result. */ | |
5825 | ||
5826 | tree | |
5827 | gimplify_build1 (block_stmt_iterator *bsi, enum tree_code code, tree type, | |
5828 | tree a) | |
5829 | { | |
5830 | tree ret; | |
5831 | ||
5832 | ret = fold (build1 (code, type, a)); | |
5833 | STRIP_NOPS (ret); | |
5834 | ||
5835 | return gimplify_val (bsi, type, ret); | |
5836 | } | |
5837 | ||
5838 | ||
6de9cd9a DN |
5839 | \f |
5840 | /* Emit return warnings. */ | |
5841 | ||
5842 | static void | |
5843 | execute_warn_function_return (void) | |
5844 | { | |
9506ac2b PB |
5845 | #ifdef USE_MAPPED_LOCATION |
5846 | source_location location; | |
5847 | #else | |
6de9cd9a | 5848 | location_t *locus; |
9506ac2b | 5849 | #endif |
6de9cd9a DN |
5850 | tree last; |
5851 | edge e; | |
628f6a4e | 5852 | edge_iterator ei; |
6de9cd9a DN |
5853 | |
5854 | if (warn_missing_noreturn | |
5855 | && !TREE_THIS_VOLATILE (cfun->decl) | |
628f6a4e | 5856 | && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0 |
6de9cd9a | 5857 | && !lang_hooks.function.missing_noreturn_ok_p (cfun->decl)) |
971801ff JM |
5858 | warning ("%Jfunction might be possible candidate for " |
5859 | "attribute %<noreturn%>", | |
6de9cd9a DN |
5860 | cfun->decl); |
5861 | ||
5862 | /* If we have a path to EXIT, then we do return. */ | |
5863 | if (TREE_THIS_VOLATILE (cfun->decl) | |
628f6a4e | 5864 | && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0) |
6de9cd9a | 5865 | { |
9506ac2b PB |
5866 | #ifdef USE_MAPPED_LOCATION |
5867 | location = UNKNOWN_LOCATION; | |
5868 | #else | |
6de9cd9a | 5869 | locus = NULL; |
9506ac2b | 5870 | #endif |
628f6a4e | 5871 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds) |
6de9cd9a DN |
5872 | { |
5873 | last = last_stmt (e->src); | |
5874 | if (TREE_CODE (last) == RETURN_EXPR | |
9506ac2b PB |
5875 | #ifdef USE_MAPPED_LOCATION |
5876 | && (location = EXPR_LOCATION (last)) != UNKNOWN_LOCATION) | |
5877 | #else | |
6de9cd9a | 5878 | && (locus = EXPR_LOCUS (last)) != NULL) |
9506ac2b | 5879 | #endif |
6de9cd9a DN |
5880 | break; |
5881 | } | |
9506ac2b PB |
5882 | #ifdef USE_MAPPED_LOCATION |
5883 | if (location == UNKNOWN_LOCATION) | |
5884 | location = cfun->function_end_locus; | |
971801ff | 5885 | warning ("%H%<noreturn%> function does return", &location); |
9506ac2b | 5886 | #else |
6de9cd9a DN |
5887 | if (!locus) |
5888 | locus = &cfun->function_end_locus; | |
971801ff | 5889 | warning ("%H%<noreturn%> function does return", locus); |
9506ac2b | 5890 | #endif |
6de9cd9a DN |
5891 | } |
5892 | ||
5893 | /* If we see "return;" in some basic block, then we do reach the end | |
5894 | without returning a value. */ | |
5895 | else if (warn_return_type | |
089efaa4 | 5896 | && !TREE_NO_WARNING (cfun->decl) |
628f6a4e | 5897 | && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0 |
6de9cd9a DN |
5898 | && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl)))) |
5899 | { | |
628f6a4e | 5900 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds) |
6de9cd9a DN |
5901 | { |
5902 | tree last = last_stmt (e->src); | |
5903 | if (TREE_CODE (last) == RETURN_EXPR | |
5904 | && TREE_OPERAND (last, 0) == NULL) | |
5905 | { | |
9506ac2b PB |
5906 | #ifdef USE_MAPPED_LOCATION |
5907 | location = EXPR_LOCATION (last); | |
5908 | if (location == UNKNOWN_LOCATION) | |
5909 | location = cfun->function_end_locus; | |
5910 | warning ("%Hcontrol reaches end of non-void function", &location); | |
5911 | #else | |
6de9cd9a DN |
5912 | locus = EXPR_LOCUS (last); |
5913 | if (!locus) | |
5914 | locus = &cfun->function_end_locus; | |
5915 | warning ("%Hcontrol reaches end of non-void function", locus); | |
9506ac2b | 5916 | #endif |
089efaa4 | 5917 | TREE_NO_WARNING (cfun->decl) = 1; |
6de9cd9a DN |
5918 | break; |
5919 | } | |
5920 | } | |
5921 | } | |
5922 | } | |
5923 | ||
5924 | ||
5925 | /* Given a basic block B which ends with a conditional and has | |
5926 | precisely two successors, determine which of the edges is taken if | |
5927 | the conditional is true and which is taken if the conditional is | |
5928 | false. Set TRUE_EDGE and FALSE_EDGE appropriately. */ | |
5929 | ||
5930 | void | |
5931 | extract_true_false_edges_from_block (basic_block b, | |
5932 | edge *true_edge, | |
5933 | edge *false_edge) | |
5934 | { | |
628f6a4e | 5935 | edge e = EDGE_SUCC (b, 0); |
6de9cd9a DN |
5936 | |
5937 | if (e->flags & EDGE_TRUE_VALUE) | |
5938 | { | |
5939 | *true_edge = e; | |
628f6a4e | 5940 | *false_edge = EDGE_SUCC (b, 1); |
6de9cd9a DN |
5941 | } |
5942 | else | |
5943 | { | |
5944 | *false_edge = e; | |
628f6a4e | 5945 | *true_edge = EDGE_SUCC (b, 1); |
6de9cd9a DN |
5946 | } |
5947 | } | |
5948 | ||
5949 | struct tree_opt_pass pass_warn_function_return = | |
5950 | { | |
5951 | NULL, /* name */ | |
5952 | NULL, /* gate */ | |
5953 | execute_warn_function_return, /* execute */ | |
5954 | NULL, /* sub */ | |
5955 | NULL, /* next */ | |
5956 | 0, /* static_pass_number */ | |
5957 | 0, /* tv_id */ | |
00bfee6f | 5958 | PROP_cfg, /* properties_required */ |
6de9cd9a DN |
5959 | 0, /* properties_provided */ |
5960 | 0, /* properties_destroyed */ | |
5961 | 0, /* todo_flags_start */ | |
9f8628ba PB |
5962 | 0, /* todo_flags_finish */ |
5963 | 0 /* letter */ | |
6de9cd9a DN |
5964 | }; |
5965 | ||
5966 | #include "gt-tree-cfg.h" |