]>
Commit | Line | Data |
---|---|---|
6de9cd9a | 1 | /* Control flow functions for trees. |
56e84019 RH |
2 | Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 |
3 | Free Software Foundation, Inc. | |
6de9cd9a DN |
4 | Contributed by Diego Novillo <dnovillo@redhat.com> |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2, or (at your option) | |
11 | any later version. | |
12 | ||
13 | GCC is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GCC; see the file COPYING. If not, write to | |
366ccddb KC |
20 | the Free Software Foundation, 51 Franklin Street, Fifth Floor, |
21 | Boston, MA 02110-1301, USA. */ | |
6de9cd9a DN |
22 | |
23 | #include "config.h" | |
24 | #include "system.h" | |
25 | #include "coretypes.h" | |
26 | #include "tm.h" | |
27 | #include "tree.h" | |
28 | #include "rtl.h" | |
29 | #include "tm_p.h" | |
30 | #include "hard-reg-set.h" | |
31 | #include "basic-block.h" | |
32 | #include "output.h" | |
6de9cd9a DN |
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" |
9af0df6b | 48 | #include "tree-ssa-propagate.h" |
6de9cd9a DN |
49 | |
50 | /* This file contains functions for building the Control Flow Graph (CFG) | |
51 | for a function tree. */ | |
52 | ||
53 | /* Local declarations. */ | |
54 | ||
55 | /* Initial capacity for the basic block array. */ | |
56 | static const int initial_cfg_capacity = 20; | |
57 | ||
d6be0d7f JL |
58 | /* This hash table allows us to efficiently lookup all CASE_LABEL_EXPRs |
59 | which use a particular edge. The CASE_LABEL_EXPRs are chained together | |
60 | via their TREE_CHAIN field, which we clear after we're done with the | |
61 | hash table to prevent problems with duplication of SWITCH_EXPRs. | |
92b6dff3 | 62 | |
d6be0d7f JL |
63 | Access to this list of CASE_LABEL_EXPRs allows us to efficiently |
64 | update the case vector in response to edge redirections. | |
92b6dff3 | 65 | |
d6be0d7f JL |
66 | Right now this table is set up and torn down at key points in the |
67 | compilation process. It would be nice if we could make the table | |
68 | more persistent. The key is getting notification of changes to | |
69 | the CFG (particularly edge removal, creation and redirection). */ | |
70 | ||
71 | struct edge_to_cases_elt | |
92b6dff3 JL |
72 | { |
73 | /* The edge itself. Necessary for hashing and equality tests. */ | |
74 | edge e; | |
75 | ||
d6be0d7f JL |
76 | /* The case labels associated with this edge. We link these up via |
77 | their TREE_CHAIN field, then we wipe out the TREE_CHAIN fields | |
78 | when we destroy the hash table. This prevents problems when copying | |
79 | SWITCH_EXPRs. */ | |
80 | tree case_labels; | |
92b6dff3 JL |
81 | }; |
82 | ||
d6be0d7f | 83 | static htab_t edge_to_cases; |
92b6dff3 | 84 | |
6de9cd9a DN |
85 | /* CFG statistics. */ |
86 | struct cfg_stats_d | |
87 | { | |
88 | long num_merged_labels; | |
89 | }; | |
90 | ||
91 | static struct cfg_stats_d cfg_stats; | |
92 | ||
93 | /* Nonzero if we found a computed goto while building basic blocks. */ | |
94 | static bool found_computed_goto; | |
95 | ||
96 | /* Basic blocks and flowgraphs. */ | |
97 | static basic_block create_bb (void *, void *, basic_block); | |
6de9cd9a DN |
98 | static void make_blocks (tree); |
99 | static void factor_computed_gotos (void); | |
6de9cd9a DN |
100 | |
101 | /* Edges. */ | |
102 | static void make_edges (void); | |
6de9cd9a DN |
103 | static void make_cond_expr_edges (basic_block); |
104 | static void make_switch_expr_edges (basic_block); | |
105 | static void make_goto_expr_edges (basic_block); | |
56e84019 | 106 | static void make_omp_sections_edges (basic_block); |
6de9cd9a DN |
107 | static edge tree_redirect_edge_and_branch (edge, basic_block); |
108 | static edge tree_try_redirect_by_replacing_jump (edge, basic_block); | |
c2924966 | 109 | static unsigned int split_critical_edges (void); |
6de9cd9a DN |
110 | |
111 | /* Various helpers. */ | |
112 | static inline bool stmt_starts_bb_p (tree, tree); | |
113 | static int tree_verify_flow_info (void); | |
114 | static void tree_make_forwarder_block (edge); | |
6de9cd9a DN |
115 | static void tree_cfg2vcg (FILE *); |
116 | ||
117 | /* Flowgraph optimization and cleanup. */ | |
118 | static void tree_merge_blocks (basic_block, basic_block); | |
119 | static bool tree_can_merge_blocks_p (basic_block, basic_block); | |
120 | static void remove_bb (basic_block); | |
be477406 | 121 | static edge find_taken_edge_computed_goto (basic_block, tree); |
6de9cd9a DN |
122 | static edge find_taken_edge_cond_expr (basic_block, tree); |
123 | static edge find_taken_edge_switch_expr (basic_block, tree); | |
124 | static tree find_case_label_for_value (tree, tree); | |
6de9cd9a | 125 | |
a930a4ef JH |
126 | void |
127 | init_empty_tree_cfg (void) | |
128 | { | |
129 | /* Initialize the basic block array. */ | |
130 | init_flow (); | |
131 | profile_status = PROFILE_ABSENT; | |
24bd1a0b DB |
132 | n_basic_blocks = NUM_FIXED_BLOCKS; |
133 | last_basic_block = NUM_FIXED_BLOCKS; | |
68f9b844 KH |
134 | basic_block_info = VEC_alloc (basic_block, gc, initial_cfg_capacity); |
135 | VEC_safe_grow (basic_block, gc, basic_block_info, initial_cfg_capacity); | |
136 | memset (VEC_address (basic_block, basic_block_info), 0, | |
137 | sizeof (basic_block) * initial_cfg_capacity); | |
a930a4ef JH |
138 | |
139 | /* Build a mapping of labels to their associated blocks. */ | |
e597f337 KH |
140 | label_to_block_map = VEC_alloc (basic_block, gc, initial_cfg_capacity); |
141 | VEC_safe_grow (basic_block, gc, label_to_block_map, initial_cfg_capacity); | |
142 | memset (VEC_address (basic_block, label_to_block_map), | |
143 | 0, sizeof (basic_block) * initial_cfg_capacity); | |
a930a4ef | 144 | |
68f9b844 KH |
145 | SET_BASIC_BLOCK (ENTRY_BLOCK, ENTRY_BLOCK_PTR); |
146 | SET_BASIC_BLOCK (EXIT_BLOCK, EXIT_BLOCK_PTR); | |
a930a4ef JH |
147 | ENTRY_BLOCK_PTR->next_bb = EXIT_BLOCK_PTR; |
148 | EXIT_BLOCK_PTR->prev_bb = ENTRY_BLOCK_PTR; | |
a930a4ef | 149 | } |
6de9cd9a DN |
150 | |
151 | /*--------------------------------------------------------------------------- | |
152 | Create basic blocks | |
153 | ---------------------------------------------------------------------------*/ | |
154 | ||
155 | /* Entry point to the CFG builder for trees. TP points to the list of | |
156 | statements to be added to the flowgraph. */ | |
157 | ||
158 | static void | |
159 | build_tree_cfg (tree *tp) | |
160 | { | |
161 | /* Register specific tree functions. */ | |
162 | tree_register_cfg_hooks (); | |
163 | ||
6de9cd9a DN |
164 | memset ((void *) &cfg_stats, 0, sizeof (cfg_stats)); |
165 | ||
a930a4ef | 166 | init_empty_tree_cfg (); |
6de9cd9a DN |
167 | |
168 | found_computed_goto = 0; | |
169 | make_blocks (*tp); | |
170 | ||
171 | /* Computed gotos are hell to deal with, especially if there are | |
172 | lots of them with a large number of destinations. So we factor | |
173 | them to a common computed goto location before we build the | |
174 | edge list. After we convert back to normal form, we will un-factor | |
175 | the computed gotos since factoring introduces an unwanted jump. */ | |
176 | if (found_computed_goto) | |
177 | factor_computed_gotos (); | |
178 | ||
f0b698c1 | 179 | /* Make sure there is always at least one block, even if it's empty. */ |
24bd1a0b | 180 | if (n_basic_blocks == NUM_FIXED_BLOCKS) |
6de9cd9a DN |
181 | create_empty_bb (ENTRY_BLOCK_PTR); |
182 | ||
6de9cd9a | 183 | /* Adjust the size of the array. */ |
68f9b844 KH |
184 | if (VEC_length (basic_block, basic_block_info) < (size_t) n_basic_blocks) |
185 | { | |
186 | size_t old_size = VEC_length (basic_block, basic_block_info); | |
187 | basic_block *p; | |
188 | VEC_safe_grow (basic_block, gc, basic_block_info, n_basic_blocks); | |
189 | p = VEC_address (basic_block, basic_block_info); | |
190 | memset (&p[old_size], 0, | |
191 | sizeof (basic_block) * (n_basic_blocks - old_size)); | |
192 | } | |
6de9cd9a | 193 | |
f667741c SB |
194 | /* To speed up statement iterator walks, we first purge dead labels. */ |
195 | cleanup_dead_labels (); | |
196 | ||
197 | /* Group case nodes to reduce the number of edges. | |
198 | We do this after cleaning up dead labels because otherwise we miss | |
199 | a lot of obvious case merging opportunities. */ | |
200 | group_case_labels (); | |
201 | ||
6de9cd9a DN |
202 | /* Create the edges of the flowgraph. */ |
203 | make_edges (); | |
204 | ||
205 | /* Debugging dumps. */ | |
206 | ||
207 | /* Write the flowgraph to a VCG file. */ | |
208 | { | |
209 | int local_dump_flags; | |
10d22567 ZD |
210 | FILE *vcg_file = dump_begin (TDI_vcg, &local_dump_flags); |
211 | if (vcg_file) | |
6de9cd9a | 212 | { |
10d22567 ZD |
213 | tree_cfg2vcg (vcg_file); |
214 | dump_end (TDI_vcg, vcg_file); | |
6de9cd9a DN |
215 | } |
216 | } | |
217 | ||
81cfbbc2 JH |
218 | #ifdef ENABLE_CHECKING |
219 | verify_stmts (); | |
220 | #endif | |
221 | ||
6de9cd9a DN |
222 | /* Dump a textual representation of the flowgraph. */ |
223 | if (dump_file) | |
224 | dump_tree_cfg (dump_file, dump_flags); | |
225 | } | |
226 | ||
c2924966 | 227 | static unsigned int |
6de9cd9a DN |
228 | execute_build_cfg (void) |
229 | { | |
230 | build_tree_cfg (&DECL_SAVED_TREE (current_function_decl)); | |
c2924966 | 231 | return 0; |
6de9cd9a DN |
232 | } |
233 | ||
234 | struct tree_opt_pass pass_build_cfg = | |
235 | { | |
236 | "cfg", /* name */ | |
237 | NULL, /* gate */ | |
238 | execute_build_cfg, /* execute */ | |
239 | NULL, /* sub */ | |
240 | NULL, /* next */ | |
241 | 0, /* static_pass_number */ | |
242 | TV_TREE_CFG, /* tv_id */ | |
243 | PROP_gimple_leh, /* properties_required */ | |
244 | PROP_cfg, /* properties_provided */ | |
245 | 0, /* properties_destroyed */ | |
246 | 0, /* todo_flags_start */ | |
9f8628ba PB |
247 | TODO_verify_stmts, /* todo_flags_finish */ |
248 | 0 /* letter */ | |
6de9cd9a DN |
249 | }; |
250 | ||
251 | /* Search the CFG for any computed gotos. If found, factor them to a | |
252 | common computed goto site. Also record the location of that site so | |
253 | that we can un-factor the gotos after we have converted back to | |
254 | normal form. */ | |
255 | ||
256 | static void | |
257 | factor_computed_gotos (void) | |
258 | { | |
259 | basic_block bb; | |
260 | tree factored_label_decl = NULL; | |
261 | tree var = NULL; | |
262 | tree factored_computed_goto_label = NULL; | |
263 | tree factored_computed_goto = NULL; | |
264 | ||
265 | /* We know there are one or more computed gotos in this function. | |
266 | Examine the last statement in each basic block to see if the block | |
267 | ends with a computed goto. */ | |
268 | ||
269 | FOR_EACH_BB (bb) | |
270 | { | |
271 | block_stmt_iterator bsi = bsi_last (bb); | |
272 | tree last; | |
273 | ||
274 | if (bsi_end_p (bsi)) | |
275 | continue; | |
276 | last = bsi_stmt (bsi); | |
277 | ||
278 | /* Ignore the computed goto we create when we factor the original | |
279 | computed gotos. */ | |
280 | if (last == factored_computed_goto) | |
281 | continue; | |
282 | ||
283 | /* If the last statement is a computed goto, factor it. */ | |
284 | if (computed_goto_p (last)) | |
285 | { | |
286 | tree assignment; | |
287 | ||
288 | /* The first time we find a computed goto we need to create | |
289 | the factored goto block and the variable each original | |
290 | computed goto will use for their goto destination. */ | |
291 | if (! factored_computed_goto) | |
292 | { | |
293 | basic_block new_bb = create_empty_bb (bb); | |
294 | block_stmt_iterator new_bsi = bsi_start (new_bb); | |
295 | ||
296 | /* Create the destination of the factored goto. Each original | |
297 | computed goto will put its desired destination into this | |
298 | variable and jump to the label we create immediately | |
299 | below. */ | |
300 | var = create_tmp_var (ptr_type_node, "gotovar"); | |
301 | ||
302 | /* Build a label for the new block which will contain the | |
303 | factored computed goto. */ | |
304 | factored_label_decl = create_artificial_label (); | |
305 | factored_computed_goto_label | |
306 | = build1 (LABEL_EXPR, void_type_node, factored_label_decl); | |
307 | bsi_insert_after (&new_bsi, factored_computed_goto_label, | |
308 | BSI_NEW_STMT); | |
309 | ||
310 | /* Build our new computed goto. */ | |
311 | factored_computed_goto = build1 (GOTO_EXPR, void_type_node, var); | |
312 | bsi_insert_after (&new_bsi, factored_computed_goto, | |
313 | BSI_NEW_STMT); | |
314 | } | |
315 | ||
316 | /* Copy the original computed goto's destination into VAR. */ | |
b4257cfc RG |
317 | assignment = build2 (MODIFY_EXPR, ptr_type_node, |
318 | var, GOTO_DESTINATION (last)); | |
6de9cd9a DN |
319 | bsi_insert_before (&bsi, assignment, BSI_SAME_STMT); |
320 | ||
321 | /* And re-vector the computed goto to the new destination. */ | |
322 | GOTO_DESTINATION (last) = factored_label_decl; | |
323 | } | |
324 | } | |
325 | } | |
326 | ||
327 | ||
6de9cd9a DN |
328 | /* Build a flowgraph for the statement_list STMT_LIST. */ |
329 | ||
330 | static void | |
331 | make_blocks (tree stmt_list) | |
332 | { | |
333 | tree_stmt_iterator i = tsi_start (stmt_list); | |
334 | tree stmt = NULL; | |
335 | bool start_new_block = true; | |
336 | bool first_stmt_of_list = true; | |
337 | basic_block bb = ENTRY_BLOCK_PTR; | |
338 | ||
339 | while (!tsi_end_p (i)) | |
340 | { | |
341 | tree prev_stmt; | |
342 | ||
343 | prev_stmt = stmt; | |
344 | stmt = tsi_stmt (i); | |
345 | ||
346 | /* If the statement starts a new basic block or if we have determined | |
347 | in a previous pass that we need to create a new block for STMT, do | |
348 | so now. */ | |
349 | if (start_new_block || stmt_starts_bb_p (stmt, prev_stmt)) | |
350 | { | |
351 | if (!first_stmt_of_list) | |
352 | stmt_list = tsi_split_statement_list_before (&i); | |
353 | bb = create_basic_block (stmt_list, NULL, bb); | |
354 | start_new_block = false; | |
355 | } | |
356 | ||
357 | /* Now add STMT to BB and create the subgraphs for special statement | |
358 | codes. */ | |
359 | set_bb_for_stmt (stmt, bb); | |
360 | ||
361 | if (computed_goto_p (stmt)) | |
362 | found_computed_goto = true; | |
363 | ||
364 | /* If STMT is a basic block terminator, set START_NEW_BLOCK for the | |
365 | next iteration. */ | |
366 | if (stmt_ends_bb_p (stmt)) | |
367 | start_new_block = true; | |
368 | ||
369 | tsi_next (&i); | |
370 | first_stmt_of_list = false; | |
371 | } | |
372 | } | |
373 | ||
374 | ||
375 | /* Create and return a new empty basic block after bb AFTER. */ | |
376 | ||
377 | static basic_block | |
378 | create_bb (void *h, void *e, basic_block after) | |
379 | { | |
380 | basic_block bb; | |
381 | ||
1e128c5f | 382 | gcc_assert (!e); |
6de9cd9a | 383 | |
27fd69fa KH |
384 | /* Create and initialize a new basic block. Since alloc_block uses |
385 | ggc_alloc_cleared to allocate a basic block, we do not have to | |
386 | clear the newly allocated basic block here. */ | |
6de9cd9a | 387 | bb = alloc_block (); |
6de9cd9a DN |
388 | |
389 | bb->index = last_basic_block; | |
390 | bb->flags = BB_NEW; | |
858904db | 391 | bb->stmt_list = h ? (tree) h : alloc_stmt_list (); |
6de9cd9a DN |
392 | |
393 | /* Add the new block to the linked list of blocks. */ | |
394 | link_block (bb, after); | |
395 | ||
396 | /* Grow the basic block array if needed. */ | |
68f9b844 | 397 | if ((size_t) last_basic_block == VEC_length (basic_block, basic_block_info)) |
6de9cd9a | 398 | { |
68f9b844 | 399 | size_t old_size = VEC_length (basic_block, basic_block_info); |
6de9cd9a | 400 | size_t new_size = last_basic_block + (last_basic_block + 3) / 4; |
68f9b844 KH |
401 | basic_block *p; |
402 | VEC_safe_grow (basic_block, gc, basic_block_info, new_size); | |
403 | p = VEC_address (basic_block, basic_block_info); | |
404 | memset (&p[old_size], 0, sizeof (basic_block) * (new_size - old_size)); | |
6de9cd9a DN |
405 | } |
406 | ||
407 | /* Add the newly created block to the array. */ | |
68f9b844 | 408 | SET_BASIC_BLOCK (last_basic_block, bb); |
6de9cd9a | 409 | |
6de9cd9a DN |
410 | n_basic_blocks++; |
411 | last_basic_block++; | |
412 | ||
6de9cd9a DN |
413 | return bb; |
414 | } | |
415 | ||
416 | ||
417 | /*--------------------------------------------------------------------------- | |
418 | Edge creation | |
419 | ---------------------------------------------------------------------------*/ | |
420 | ||
fca01525 KH |
421 | /* Fold COND_EXPR_COND of each COND_EXPR. */ |
422 | ||
e21aff8a | 423 | void |
fca01525 KH |
424 | fold_cond_expr_cond (void) |
425 | { | |
426 | basic_block bb; | |
427 | ||
428 | FOR_EACH_BB (bb) | |
429 | { | |
430 | tree stmt = last_stmt (bb); | |
431 | ||
432 | if (stmt | |
433 | && TREE_CODE (stmt) == COND_EXPR) | |
434 | { | |
435 | tree cond = fold (COND_EXPR_COND (stmt)); | |
436 | if (integer_zerop (cond)) | |
4bafe847 | 437 | COND_EXPR_COND (stmt) = boolean_false_node; |
fca01525 | 438 | else if (integer_onep (cond)) |
4bafe847 | 439 | COND_EXPR_COND (stmt) = boolean_true_node; |
fca01525 KH |
440 | } |
441 | } | |
442 | } | |
443 | ||
6de9cd9a DN |
444 | /* Join all the blocks in the flowgraph. */ |
445 | ||
446 | static void | |
447 | make_edges (void) | |
448 | { | |
449 | basic_block bb; | |
6de9cd9a DN |
450 | |
451 | /* Create an edge from entry to the first block with executable | |
452 | statements in it. */ | |
24bd1a0b | 453 | make_edge (ENTRY_BLOCK_PTR, BASIC_BLOCK (NUM_FIXED_BLOCKS), EDGE_FALLTHRU); |
6de9cd9a | 454 | |
adb35797 | 455 | /* Traverse the basic block array placing edges. */ |
6de9cd9a DN |
456 | FOR_EACH_BB (bb) |
457 | { | |
6de9cd9a | 458 | tree last = last_stmt (bb); |
56e84019 | 459 | bool fallthru; |
6de9cd9a | 460 | |
56e84019 | 461 | if (last) |
6de9cd9a | 462 | { |
56e84019 RH |
463 | switch (TREE_CODE (last)) |
464 | { | |
465 | case GOTO_EXPR: | |
466 | make_goto_expr_edges (bb); | |
467 | fallthru = false; | |
468 | break; | |
469 | case RETURN_EXPR: | |
470 | make_edge (bb, EXIT_BLOCK_PTR, 0); | |
471 | fallthru = false; | |
472 | break; | |
473 | case COND_EXPR: | |
474 | make_cond_expr_edges (bb); | |
475 | fallthru = false; | |
476 | break; | |
477 | case SWITCH_EXPR: | |
478 | make_switch_expr_edges (bb); | |
479 | fallthru = false; | |
480 | break; | |
481 | case RESX_EXPR: | |
482 | make_eh_edges (last); | |
483 | fallthru = false; | |
484 | break; | |
485 | ||
486 | case CALL_EXPR: | |
487 | /* If this function receives a nonlocal goto, then we need to | |
488 | make edges from this call site to all the nonlocal goto | |
489 | handlers. */ | |
490 | if (TREE_SIDE_EFFECTS (last) | |
491 | && current_function_has_nonlocal_label) | |
492 | make_goto_expr_edges (bb); | |
6de9cd9a | 493 | |
56e84019 RH |
494 | /* If this statement has reachable exception handlers, then |
495 | create abnormal edges to them. */ | |
496 | make_eh_edges (last); | |
497 | ||
498 | /* Some calls are known not to return. */ | |
499 | fallthru = !(call_expr_flags (last) & ECF_NORETURN); | |
500 | break; | |
501 | ||
502 | case MODIFY_EXPR: | |
503 | if (is_ctrl_altering_stmt (last)) | |
504 | { | |
505 | /* A MODIFY_EXPR may have a CALL_EXPR on its RHS and the | |
506 | CALL_EXPR may have an abnormal edge. Search the RHS for | |
507 | this case and create any required edges. */ | |
508 | tree op = get_call_expr_in (last); | |
509 | if (op && TREE_SIDE_EFFECTS (op) | |
510 | && current_function_has_nonlocal_label) | |
511 | make_goto_expr_edges (bb); | |
512 | ||
513 | make_eh_edges (last); | |
514 | } | |
515 | fallthru = true; | |
516 | break; | |
517 | ||
518 | case OMP_PARALLEL: | |
519 | case OMP_FOR: | |
520 | case OMP_SINGLE: | |
521 | case OMP_MASTER: | |
522 | case OMP_ORDERED: | |
523 | case OMP_CRITICAL: | |
524 | case OMP_SECTION: | |
525 | fallthru = true; | |
526 | break; | |
527 | ||
528 | case OMP_RETURN_EXPR: | |
529 | /* In the case of an OMP_SECTION, we may have already made | |
530 | an edge in make_omp_sections_edges. */ | |
531 | fallthru = EDGE_COUNT (bb->succs) == 0; | |
532 | break; | |
533 | ||
534 | case OMP_SECTIONS: | |
535 | make_omp_sections_edges (bb); | |
536 | fallthru = false; | |
537 | break; | |
538 | ||
539 | default: | |
540 | gcc_assert (!stmt_ends_bb_p (last)); | |
541 | fallthru = true; | |
542 | } | |
6de9cd9a | 543 | } |
56e84019 RH |
544 | else |
545 | fallthru = true; | |
6de9cd9a | 546 | |
56e84019 | 547 | if (fallthru) |
6de9cd9a DN |
548 | make_edge (bb, bb->next_bb, EDGE_FALLTHRU); |
549 | } | |
550 | ||
fca01525 KH |
551 | /* Fold COND_EXPR_COND of each COND_EXPR. */ |
552 | fold_cond_expr_cond (); | |
553 | ||
6de9cd9a DN |
554 | /* Clean up the graph and warn for unreachable code. */ |
555 | cleanup_tree_cfg (); | |
556 | } | |
557 | ||
558 | ||
50674e96 DN |
559 | /* Link an OMP_SECTIONS block to all the OMP_SECTION blocks in its body. */ |
560 | ||
561 | static void | |
562 | make_omp_sections_edges (basic_block bb) | |
563 | { | |
564 | basic_block exit_bb; | |
565 | size_t i, n; | |
566 | tree vec, stmt; | |
567 | ||
568 | stmt = last_stmt (bb); | |
569 | vec = OMP_SECTIONS_SECTIONS (stmt); | |
570 | n = TREE_VEC_LENGTH (vec); | |
571 | exit_bb = bb_for_stmt (TREE_VEC_ELT (vec, n - 1)); | |
572 | ||
573 | for (i = 0; i < n - 1; i += 2) | |
574 | { | |
575 | basic_block start_bb = bb_for_stmt (TREE_VEC_ELT (vec, i)); | |
576 | basic_block end_bb = bb_for_stmt (TREE_VEC_ELT (vec, i + 1)); | |
56e84019 | 577 | make_edge (bb, start_bb, 0); |
50674e96 DN |
578 | make_edge (end_bb, exit_bb, EDGE_FALLTHRU); |
579 | } | |
580 | ||
581 | /* Once the CFG has been built, the vector of sections is no longer | |
582 | useful. The region can be easily obtained with build_omp_regions. | |
583 | Furthermore, this sharing of tree expressions is not allowed by the | |
584 | statement verifier. */ | |
585 | OMP_SECTIONS_SECTIONS (stmt) = NULL_TREE; | |
586 | } | |
587 | ||
6de9cd9a DN |
588 | /* Create the edges for a COND_EXPR starting at block BB. |
589 | At this point, both clauses must contain only simple gotos. */ | |
590 | ||
591 | static void | |
592 | make_cond_expr_edges (basic_block bb) | |
593 | { | |
594 | tree entry = last_stmt (bb); | |
595 | basic_block then_bb, else_bb; | |
596 | tree then_label, else_label; | |
d783b2a2 | 597 | edge e; |
6de9cd9a | 598 | |
1e128c5f GB |
599 | gcc_assert (entry); |
600 | gcc_assert (TREE_CODE (entry) == COND_EXPR); | |
6de9cd9a DN |
601 | |
602 | /* Entry basic blocks for each component. */ | |
603 | then_label = GOTO_DESTINATION (COND_EXPR_THEN (entry)); | |
604 | else_label = GOTO_DESTINATION (COND_EXPR_ELSE (entry)); | |
605 | then_bb = label_to_block (then_label); | |
606 | else_bb = label_to_block (else_label); | |
607 | ||
d783b2a2 JH |
608 | e = make_edge (bb, then_bb, EDGE_TRUE_VALUE); |
609 | #ifdef USE_MAPPED_LOCATION | |
610 | e->goto_locus = EXPR_LOCATION (COND_EXPR_THEN (entry)); | |
611 | #else | |
612 | e->goto_locus = EXPR_LOCUS (COND_EXPR_THEN (entry)); | |
613 | #endif | |
614 | e = make_edge (bb, else_bb, EDGE_FALSE_VALUE); | |
615 | if (e) | |
616 | { | |
617 | #ifdef USE_MAPPED_LOCATION | |
618 | e->goto_locus = EXPR_LOCATION (COND_EXPR_ELSE (entry)); | |
619 | #else | |
620 | e->goto_locus = EXPR_LOCUS (COND_EXPR_ELSE (entry)); | |
621 | #endif | |
622 | } | |
6de9cd9a DN |
623 | } |
624 | ||
d6be0d7f | 625 | /* Hashing routine for EDGE_TO_CASES. */ |
92b6dff3 JL |
626 | |
627 | static hashval_t | |
d6be0d7f | 628 | edge_to_cases_hash (const void *p) |
92b6dff3 | 629 | { |
d6be0d7f | 630 | edge e = ((struct edge_to_cases_elt *)p)->e; |
92b6dff3 JL |
631 | |
632 | /* Hash on the edge itself (which is a pointer). */ | |
633 | return htab_hash_pointer (e); | |
634 | } | |
635 | ||
d6be0d7f | 636 | /* Equality routine for EDGE_TO_CASES, edges are unique, so testing |
92b6dff3 JL |
637 | for equality is just a pointer comparison. */ |
638 | ||
639 | static int | |
d6be0d7f | 640 | edge_to_cases_eq (const void *p1, const void *p2) |
92b6dff3 | 641 | { |
d6be0d7f JL |
642 | edge e1 = ((struct edge_to_cases_elt *)p1)->e; |
643 | edge e2 = ((struct edge_to_cases_elt *)p2)->e; | |
92b6dff3 JL |
644 | |
645 | return e1 == e2; | |
646 | } | |
647 | ||
d6be0d7f JL |
648 | /* Called for each element in the hash table (P) as we delete the |
649 | edge to cases hash table. | |
650 | ||
651 | Clear all the TREE_CHAINs to prevent problems with copying of | |
652 | SWITCH_EXPRs and structure sharing rules, then free the hash table | |
653 | element. */ | |
654 | ||
655 | static void | |
656 | edge_to_cases_cleanup (void *p) | |
657 | { | |
858904db | 658 | struct edge_to_cases_elt *elt = (struct edge_to_cases_elt *) p; |
d6be0d7f JL |
659 | tree t, next; |
660 | ||
661 | for (t = elt->case_labels; t; t = next) | |
662 | { | |
663 | next = TREE_CHAIN (t); | |
664 | TREE_CHAIN (t) = NULL; | |
665 | } | |
666 | free (p); | |
667 | } | |
668 | ||
669 | /* Start recording information mapping edges to case labels. */ | |
670 | ||
c9784e6d | 671 | void |
d6be0d7f JL |
672 | start_recording_case_labels (void) |
673 | { | |
674 | gcc_assert (edge_to_cases == NULL); | |
675 | ||
676 | edge_to_cases = htab_create (37, | |
677 | edge_to_cases_hash, | |
678 | edge_to_cases_eq, | |
679 | edge_to_cases_cleanup); | |
680 | } | |
681 | ||
682 | /* Return nonzero if we are recording information for case labels. */ | |
683 | ||
684 | static bool | |
685 | recording_case_labels_p (void) | |
686 | { | |
687 | return (edge_to_cases != NULL); | |
688 | } | |
689 | ||
690 | /* Stop recording information mapping edges to case labels and | |
691 | remove any information we have recorded. */ | |
c9784e6d | 692 | void |
d6be0d7f JL |
693 | end_recording_case_labels (void) |
694 | { | |
695 | htab_delete (edge_to_cases); | |
696 | edge_to_cases = NULL; | |
697 | } | |
698 | ||
92b6dff3 JL |
699 | /* Record that CASE_LABEL (a CASE_LABEL_EXPR) references edge E. */ |
700 | ||
701 | static void | |
702 | record_switch_edge (edge e, tree case_label) | |
703 | { | |
d6be0d7f | 704 | struct edge_to_cases_elt *elt; |
92b6dff3 JL |
705 | void **slot; |
706 | ||
707 | /* Build a hash table element so we can see if E is already | |
708 | in the table. */ | |
858904db | 709 | elt = XNEW (struct edge_to_cases_elt); |
92b6dff3 | 710 | elt->e = e; |
d6be0d7f | 711 | elt->case_labels = case_label; |
92b6dff3 | 712 | |
d6be0d7f | 713 | slot = htab_find_slot (edge_to_cases, elt, INSERT); |
92b6dff3 JL |
714 | |
715 | if (*slot == NULL) | |
716 | { | |
717 | /* E was not in the hash table. Install E into the hash table. */ | |
718 | *slot = (void *)elt; | |
719 | } | |
720 | else | |
721 | { | |
722 | /* E was already in the hash table. Free ELT as we do not need it | |
723 | anymore. */ | |
724 | free (elt); | |
725 | ||
726 | /* Get the entry stored in the hash table. */ | |
d6be0d7f | 727 | elt = (struct edge_to_cases_elt *) *slot; |
92b6dff3 | 728 | |
d6be0d7f JL |
729 | /* Add it to the chain of CASE_LABEL_EXPRs referencing E. */ |
730 | TREE_CHAIN (case_label) = elt->case_labels; | |
731 | elt->case_labels = case_label; | |
92b6dff3 JL |
732 | } |
733 | } | |
734 | ||
d6be0d7f JL |
735 | /* If we are inside a {start,end}_recording_cases block, then return |
736 | a chain of CASE_LABEL_EXPRs from T which reference E. | |
737 | ||
738 | Otherwise return NULL. */ | |
92b6dff3 JL |
739 | |
740 | static tree | |
d6be0d7f | 741 | get_cases_for_edge (edge e, tree t) |
92b6dff3 | 742 | { |
d6be0d7f | 743 | struct edge_to_cases_elt elt, *elt_p; |
92b6dff3 | 744 | void **slot; |
d6be0d7f JL |
745 | size_t i, n; |
746 | tree vec; | |
92b6dff3 | 747 | |
d6be0d7f JL |
748 | /* If we are not recording cases, then we do not have CASE_LABEL_EXPR |
749 | chains available. Return NULL so the caller can detect this case. */ | |
750 | if (!recording_case_labels_p ()) | |
751 | return NULL; | |
752 | ||
753 | restart: | |
92b6dff3 | 754 | elt.e = e; |
d6be0d7f JL |
755 | elt.case_labels = NULL; |
756 | slot = htab_find_slot (edge_to_cases, &elt, NO_INSERT); | |
92b6dff3 JL |
757 | |
758 | if (slot) | |
759 | { | |
d6be0d7f JL |
760 | elt_p = (struct edge_to_cases_elt *)*slot; |
761 | return elt_p->case_labels; | |
92b6dff3 JL |
762 | } |
763 | ||
d6be0d7f JL |
764 | /* If we did not find E in the hash table, then this must be the first |
765 | time we have been queried for information about E & T. Add all the | |
766 | elements from T to the hash table then perform the query again. */ | |
92b6dff3 | 767 | |
d6be0d7f | 768 | vec = SWITCH_LABELS (t); |
92b6dff3 | 769 | n = TREE_VEC_LENGTH (vec); |
92b6dff3 JL |
770 | for (i = 0; i < n; i++) |
771 | { | |
d6be0d7f JL |
772 | tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i)); |
773 | basic_block label_bb = label_to_block (lab); | |
774 | record_switch_edge (find_edge (e->src, label_bb), TREE_VEC_ELT (vec, i)); | |
92b6dff3 | 775 | } |
d6be0d7f | 776 | goto restart; |
92b6dff3 | 777 | } |
6de9cd9a DN |
778 | |
779 | /* Create the edges for a SWITCH_EXPR starting at block BB. | |
780 | At this point, the switch body has been lowered and the | |
781 | SWITCH_LABELS filled in, so this is in effect a multi-way branch. */ | |
782 | ||
783 | static void | |
784 | make_switch_expr_edges (basic_block bb) | |
785 | { | |
786 | tree entry = last_stmt (bb); | |
787 | size_t i, n; | |
788 | tree vec; | |
789 | ||
790 | vec = SWITCH_LABELS (entry); | |
791 | n = TREE_VEC_LENGTH (vec); | |
792 | ||
793 | for (i = 0; i < n; ++i) | |
794 | { | |
795 | tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i)); | |
796 | basic_block label_bb = label_to_block (lab); | |
d6be0d7f | 797 | make_edge (bb, label_bb, 0); |
6de9cd9a DN |
798 | } |
799 | } | |
800 | ||
801 | ||
802 | /* Return the basic block holding label DEST. */ | |
803 | ||
804 | basic_block | |
997de8ed | 805 | label_to_block_fn (struct function *ifun, tree dest) |
6de9cd9a | 806 | { |
242229bb JH |
807 | int uid = LABEL_DECL_UID (dest); |
808 | ||
f0b698c1 KH |
809 | /* We would die hard when faced by an undefined label. Emit a label to |
810 | the very first basic block. This will hopefully make even the dataflow | |
242229bb JH |
811 | and undefined variable warnings quite right. */ |
812 | if ((errorcount || sorrycount) && uid < 0) | |
813 | { | |
24bd1a0b DB |
814 | block_stmt_iterator bsi = |
815 | bsi_start (BASIC_BLOCK (NUM_FIXED_BLOCKS)); | |
242229bb JH |
816 | tree stmt; |
817 | ||
818 | stmt = build1 (LABEL_EXPR, void_type_node, dest); | |
819 | bsi_insert_before (&bsi, stmt, BSI_NEW_STMT); | |
820 | uid = LABEL_DECL_UID (dest); | |
821 | } | |
e597f337 KH |
822 | if (VEC_length (basic_block, ifun->cfg->x_label_to_block_map) |
823 | <= (unsigned int) uid) | |
98f464e0 | 824 | return NULL; |
e597f337 | 825 | return VEC_index (basic_block, ifun->cfg->x_label_to_block_map, uid); |
6de9cd9a DN |
826 | } |
827 | ||
6de9cd9a DN |
828 | /* Create edges for a goto statement at block BB. */ |
829 | ||
830 | static void | |
831 | make_goto_expr_edges (basic_block bb) | |
832 | { | |
7d3bf067 | 833 | tree goto_t; |
6de9cd9a | 834 | basic_block target_bb; |
56e84019 | 835 | bool for_call; |
6de9cd9a DN |
836 | block_stmt_iterator last = bsi_last (bb); |
837 | ||
838 | goto_t = bsi_stmt (last); | |
839 | ||
840 | /* If the last statement is not a GOTO (i.e., it is a RETURN_EXPR, | |
841 | CALL_EXPR or MODIFY_EXPR), then the edge is an abnormal edge resulting | |
842 | from a nonlocal goto. */ | |
843 | if (TREE_CODE (goto_t) != GOTO_EXPR) | |
56e84019 | 844 | for_call = true; |
6de9cd9a DN |
845 | else |
846 | { | |
7d3bf067 | 847 | tree dest = GOTO_DESTINATION (goto_t); |
56e84019 | 848 | for_call = false; |
6de9cd9a DN |
849 | |
850 | /* A GOTO to a local label creates normal edges. */ | |
851 | if (simple_goto_p (goto_t)) | |
852 | { | |
62b857ea | 853 | edge e = make_edge (bb, label_to_block (dest), EDGE_FALLTHRU); |
9506ac2b PB |
854 | #ifdef USE_MAPPED_LOCATION |
855 | e->goto_locus = EXPR_LOCATION (goto_t); | |
856 | #else | |
62b857ea | 857 | e->goto_locus = EXPR_LOCUS (goto_t); |
9506ac2b | 858 | #endif |
736432ee | 859 | bsi_remove (&last, true); |
6de9cd9a DN |
860 | return; |
861 | } | |
862 | ||
9cf737f8 | 863 | /* Nothing more to do for nonlocal gotos. */ |
6de9cd9a DN |
864 | if (TREE_CODE (dest) == LABEL_DECL) |
865 | return; | |
866 | ||
867 | /* Computed gotos remain. */ | |
868 | } | |
869 | ||
870 | /* Look for the block starting with the destination label. In the | |
871 | case of a computed goto, make an edge to any label block we find | |
872 | in the CFG. */ | |
873 | FOR_EACH_BB (target_bb) | |
874 | { | |
875 | block_stmt_iterator bsi; | |
876 | ||
877 | for (bsi = bsi_start (target_bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
878 | { | |
879 | tree target = bsi_stmt (bsi); | |
880 | ||
881 | if (TREE_CODE (target) != LABEL_EXPR) | |
882 | break; | |
883 | ||
884 | if ( | |
885 | /* Computed GOTOs. Make an edge to every label block that has | |
886 | been marked as a potential target for a computed goto. */ | |
56e84019 | 887 | (FORCED_LABEL (LABEL_EXPR_LABEL (target)) && !for_call) |
6de9cd9a DN |
888 | /* Nonlocal GOTO target. Make an edge to every label block |
889 | that has been marked as a potential target for a nonlocal | |
890 | goto. */ | |
56e84019 | 891 | || (DECL_NONLOCAL (LABEL_EXPR_LABEL (target)) && for_call)) |
6de9cd9a DN |
892 | { |
893 | make_edge (bb, target_bb, EDGE_ABNORMAL); | |
894 | break; | |
895 | } | |
896 | } | |
897 | } | |
6de9cd9a DN |
898 | } |
899 | ||
900 | ||
901 | /*--------------------------------------------------------------------------- | |
902 | Flowgraph analysis | |
903 | ---------------------------------------------------------------------------*/ | |
904 | ||
f698d217 SB |
905 | /* Cleanup useless labels in basic blocks. This is something we wish |
906 | to do early because it allows us to group case labels before creating | |
907 | the edges for the CFG, and it speeds up block statement iterators in | |
908 | all passes later on. | |
909 | We only run this pass once, running it more than once is probably not | |
910 | profitable. */ | |
911 | ||
912 | /* A map from basic block index to the leading label of that block. */ | |
913 | static tree *label_for_bb; | |
914 | ||
915 | /* Callback for for_each_eh_region. Helper for cleanup_dead_labels. */ | |
916 | static void | |
917 | update_eh_label (struct eh_region *region) | |
918 | { | |
919 | tree old_label = get_eh_region_tree_label (region); | |
920 | if (old_label) | |
921 | { | |
165b54c3 SB |
922 | tree new_label; |
923 | basic_block bb = label_to_block (old_label); | |
924 | ||
925 | /* ??? After optimizing, there may be EH regions with labels | |
926 | that have already been removed from the function body, so | |
927 | there is no basic block for them. */ | |
928 | if (! bb) | |
929 | return; | |
930 | ||
931 | new_label = label_for_bb[bb->index]; | |
f698d217 SB |
932 | set_eh_region_tree_label (region, new_label); |
933 | } | |
934 | } | |
935 | ||
242229bb JH |
936 | /* Given LABEL return the first label in the same basic block. */ |
937 | static tree | |
938 | main_block_label (tree label) | |
939 | { | |
940 | basic_block bb = label_to_block (label); | |
941 | ||
942 | /* label_to_block possibly inserted undefined label into the chain. */ | |
943 | if (!label_for_bb[bb->index]) | |
944 | label_for_bb[bb->index] = label; | |
945 | return label_for_bb[bb->index]; | |
946 | } | |
947 | ||
b986ebf3 | 948 | /* Cleanup redundant labels. This is a three-step process: |
f698d217 SB |
949 | 1) Find the leading label for each block. |
950 | 2) Redirect all references to labels to the leading labels. | |
951 | 3) Cleanup all useless labels. */ | |
6de9cd9a | 952 | |
165b54c3 | 953 | void |
6de9cd9a DN |
954 | cleanup_dead_labels (void) |
955 | { | |
956 | basic_block bb; | |
858904db | 957 | label_for_bb = XCNEWVEC (tree, last_basic_block); |
6de9cd9a DN |
958 | |
959 | /* Find a suitable label for each block. We use the first user-defined | |
f0b698c1 | 960 | label if there is one, or otherwise just the first label we see. */ |
6de9cd9a DN |
961 | FOR_EACH_BB (bb) |
962 | { | |
963 | block_stmt_iterator i; | |
964 | ||
965 | for (i = bsi_start (bb); !bsi_end_p (i); bsi_next (&i)) | |
966 | { | |
967 | tree label, stmt = bsi_stmt (i); | |
968 | ||
969 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
970 | break; | |
971 | ||
972 | label = LABEL_EXPR_LABEL (stmt); | |
973 | ||
974 | /* If we have not yet seen a label for the current block, | |
975 | remember this one and see if there are more labels. */ | |
976 | if (! label_for_bb[bb->index]) | |
977 | { | |
978 | label_for_bb[bb->index] = label; | |
979 | continue; | |
980 | } | |
981 | ||
982 | /* If we did see a label for the current block already, but it | |
983 | is an artificially created label, replace it if the current | |
984 | label is a user defined label. */ | |
985 | if (! DECL_ARTIFICIAL (label) | |
986 | && DECL_ARTIFICIAL (label_for_bb[bb->index])) | |
987 | { | |
988 | label_for_bb[bb->index] = label; | |
989 | break; | |
990 | } | |
991 | } | |
992 | } | |
993 | ||
f698d217 SB |
994 | /* Now redirect all jumps/branches to the selected label. |
995 | First do so for each block ending in a control statement. */ | |
6de9cd9a DN |
996 | FOR_EACH_BB (bb) |
997 | { | |
998 | tree stmt = last_stmt (bb); | |
999 | if (!stmt) | |
1000 | continue; | |
1001 | ||
1002 | switch (TREE_CODE (stmt)) | |
1003 | { | |
1004 | case COND_EXPR: | |
1005 | { | |
1006 | tree true_branch, false_branch; | |
6de9cd9a DN |
1007 | |
1008 | true_branch = COND_EXPR_THEN (stmt); | |
1009 | false_branch = COND_EXPR_ELSE (stmt); | |
6de9cd9a | 1010 | |
242229bb JH |
1011 | GOTO_DESTINATION (true_branch) |
1012 | = main_block_label (GOTO_DESTINATION (true_branch)); | |
1013 | GOTO_DESTINATION (false_branch) | |
1014 | = main_block_label (GOTO_DESTINATION (false_branch)); | |
6de9cd9a DN |
1015 | |
1016 | break; | |
1017 | } | |
1018 | ||
1019 | case SWITCH_EXPR: | |
1020 | { | |
1021 | size_t i; | |
1022 | tree vec = SWITCH_LABELS (stmt); | |
1023 | size_t n = TREE_VEC_LENGTH (vec); | |
1024 | ||
1025 | /* Replace all destination labels. */ | |
1026 | for (i = 0; i < n; ++i) | |
92b6dff3 JL |
1027 | { |
1028 | tree elt = TREE_VEC_ELT (vec, i); | |
1029 | tree label = main_block_label (CASE_LABEL (elt)); | |
d6be0d7f | 1030 | CASE_LABEL (elt) = label; |
92b6dff3 | 1031 | } |
6de9cd9a DN |
1032 | break; |
1033 | } | |
1034 | ||
f667741c SB |
1035 | /* We have to handle GOTO_EXPRs until they're removed, and we don't |
1036 | remove them until after we've created the CFG edges. */ | |
1037 | case GOTO_EXPR: | |
242229bb JH |
1038 | if (! computed_goto_p (stmt)) |
1039 | { | |
1040 | GOTO_DESTINATION (stmt) | |
1041 | = main_block_label (GOTO_DESTINATION (stmt)); | |
1042 | break; | |
1043 | } | |
f667741c | 1044 | |
6de9cd9a DN |
1045 | default: |
1046 | break; | |
1047 | } | |
1048 | } | |
1049 | ||
f698d217 SB |
1050 | for_each_eh_region (update_eh_label); |
1051 | ||
6de9cd9a | 1052 | /* Finally, purge dead labels. All user-defined labels and labels that |
cea0f4f1 AP |
1053 | can be the target of non-local gotos and labels which have their |
1054 | address taken are preserved. */ | |
6de9cd9a DN |
1055 | FOR_EACH_BB (bb) |
1056 | { | |
1057 | block_stmt_iterator i; | |
1058 | tree label_for_this_bb = label_for_bb[bb->index]; | |
1059 | ||
1060 | if (! label_for_this_bb) | |
1061 | continue; | |
1062 | ||
1063 | for (i = bsi_start (bb); !bsi_end_p (i); ) | |
1064 | { | |
1065 | tree label, stmt = bsi_stmt (i); | |
1066 | ||
1067 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
1068 | break; | |
1069 | ||
1070 | label = LABEL_EXPR_LABEL (stmt); | |
1071 | ||
1072 | if (label == label_for_this_bb | |
1073 | || ! DECL_ARTIFICIAL (label) | |
cea0f4f1 AP |
1074 | || DECL_NONLOCAL (label) |
1075 | || FORCED_LABEL (label)) | |
6de9cd9a DN |
1076 | bsi_next (&i); |
1077 | else | |
736432ee | 1078 | bsi_remove (&i, true); |
6de9cd9a DN |
1079 | } |
1080 | } | |
1081 | ||
1082 | free (label_for_bb); | |
1083 | } | |
1084 | ||
f667741c SB |
1085 | /* Look for blocks ending in a multiway branch (a SWITCH_EXPR in GIMPLE), |
1086 | and scan the sorted vector of cases. Combine the ones jumping to the | |
1087 | same label. | |
1088 | Eg. three separate entries 1: 2: 3: become one entry 1..3: */ | |
1089 | ||
165b54c3 | 1090 | void |
f667741c SB |
1091 | group_case_labels (void) |
1092 | { | |
1093 | basic_block bb; | |
1094 | ||
1095 | FOR_EACH_BB (bb) | |
1096 | { | |
1097 | tree stmt = last_stmt (bb); | |
1098 | if (stmt && TREE_CODE (stmt) == SWITCH_EXPR) | |
1099 | { | |
1100 | tree labels = SWITCH_LABELS (stmt); | |
1101 | int old_size = TREE_VEC_LENGTH (labels); | |
1102 | int i, j, new_size = old_size; | |
29c4d22b AP |
1103 | tree default_case = TREE_VEC_ELT (labels, old_size - 1); |
1104 | tree default_label; | |
1105 | ||
66efeafc | 1106 | /* The default label is always the last case in a switch |
29c4d22b AP |
1107 | statement after gimplification. */ |
1108 | default_label = CASE_LABEL (default_case); | |
f667741c SB |
1109 | |
1110 | /* Look for possible opportunities to merge cases. | |
1111 | Ignore the last element of the label vector because it | |
1112 | must be the default case. */ | |
1113 | i = 0; | |
d717e500 | 1114 | while (i < old_size - 1) |
f667741c | 1115 | { |
ed9cef22 | 1116 | tree base_case, base_label, base_high; |
f667741c SB |
1117 | base_case = TREE_VEC_ELT (labels, i); |
1118 | ||
1e128c5f | 1119 | gcc_assert (base_case); |
f667741c | 1120 | base_label = CASE_LABEL (base_case); |
31e9eea2 SB |
1121 | |
1122 | /* Discard cases that have the same destination as the | |
1123 | default case. */ | |
1124 | if (base_label == default_label) | |
1125 | { | |
1126 | TREE_VEC_ELT (labels, i) = NULL_TREE; | |
1127 | i++; | |
29c4d22b | 1128 | new_size--; |
31e9eea2 SB |
1129 | continue; |
1130 | } | |
1131 | ||
f667741c SB |
1132 | base_high = CASE_HIGH (base_case) ? |
1133 | CASE_HIGH (base_case) : CASE_LOW (base_case); | |
d717e500 | 1134 | i++; |
f667741c SB |
1135 | /* Try to merge case labels. Break out when we reach the end |
1136 | of the label vector or when we cannot merge the next case | |
1137 | label with the current one. */ | |
d717e500 | 1138 | while (i < old_size - 1) |
f667741c | 1139 | { |
d717e500 | 1140 | tree merge_case = TREE_VEC_ELT (labels, i); |
f667741c SB |
1141 | tree merge_label = CASE_LABEL (merge_case); |
1142 | tree t = int_const_binop (PLUS_EXPR, base_high, | |
1143 | integer_one_node, 1); | |
1144 | ||
1145 | /* Merge the cases if they jump to the same place, | |
1146 | and their ranges are consecutive. */ | |
1147 | if (merge_label == base_label | |
1148 | && tree_int_cst_equal (CASE_LOW (merge_case), t)) | |
1149 | { | |
1150 | base_high = CASE_HIGH (merge_case) ? | |
1151 | CASE_HIGH (merge_case) : CASE_LOW (merge_case); | |
1152 | CASE_HIGH (base_case) = base_high; | |
1153 | TREE_VEC_ELT (labels, i) = NULL_TREE; | |
1154 | new_size--; | |
d717e500 | 1155 | i++; |
f667741c SB |
1156 | } |
1157 | else | |
1158 | break; | |
1159 | } | |
1160 | } | |
1161 | ||
1162 | /* Compress the case labels in the label vector, and adjust the | |
1163 | length of the vector. */ | |
1164 | for (i = 0, j = 0; i < new_size; i++) | |
1165 | { | |
1166 | while (! TREE_VEC_ELT (labels, j)) | |
1167 | j++; | |
1168 | TREE_VEC_ELT (labels, i) = TREE_VEC_ELT (labels, j++); | |
1169 | } | |
1170 | TREE_VEC_LENGTH (labels) = new_size; | |
1171 | } | |
1172 | } | |
1173 | } | |
6de9cd9a DN |
1174 | |
1175 | /* Checks whether we can merge block B into block A. */ | |
1176 | ||
1177 | static bool | |
1178 | tree_can_merge_blocks_p (basic_block a, basic_block b) | |
1179 | { | |
1180 | tree stmt; | |
1181 | block_stmt_iterator bsi; | |
38965eb2 | 1182 | tree phi; |
6de9cd9a | 1183 | |
c5cbcccf | 1184 | if (!single_succ_p (a)) |
6de9cd9a DN |
1185 | return false; |
1186 | ||
c5cbcccf | 1187 | if (single_succ_edge (a)->flags & EDGE_ABNORMAL) |
6de9cd9a DN |
1188 | return false; |
1189 | ||
c5cbcccf | 1190 | if (single_succ (a) != b) |
6de9cd9a DN |
1191 | return false; |
1192 | ||
c5cbcccf | 1193 | if (!single_pred_p (b)) |
6de9cd9a DN |
1194 | return false; |
1195 | ||
26e75214 KH |
1196 | if (b == EXIT_BLOCK_PTR) |
1197 | return false; | |
1198 | ||
6de9cd9a DN |
1199 | /* If A ends by a statement causing exceptions or something similar, we |
1200 | cannot merge the blocks. */ | |
1201 | stmt = last_stmt (a); | |
1202 | if (stmt && stmt_ends_bb_p (stmt)) | |
1203 | return false; | |
1204 | ||
1205 | /* Do not allow a block with only a non-local label to be merged. */ | |
1206 | if (stmt && TREE_CODE (stmt) == LABEL_EXPR | |
1207 | && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))) | |
1208 | return false; | |
1209 | ||
38965eb2 ZD |
1210 | /* It must be possible to eliminate all phi nodes in B. If ssa form |
1211 | is not up-to-date, we cannot eliminate any phis. */ | |
1212 | phi = phi_nodes (b); | |
1213 | if (phi) | |
1214 | { | |
1215 | if (need_ssa_update_p ()) | |
1216 | return false; | |
1217 | ||
1218 | for (; phi; phi = PHI_CHAIN (phi)) | |
1219 | if (!is_gimple_reg (PHI_RESULT (phi)) | |
1220 | && !may_propagate_copy (PHI_RESULT (phi), PHI_ARG_DEF (phi, 0))) | |
1221 | return false; | |
1222 | } | |
6de9cd9a DN |
1223 | |
1224 | /* Do not remove user labels. */ | |
1225 | for (bsi = bsi_start (b); !bsi_end_p (bsi); bsi_next (&bsi)) | |
1226 | { | |
1227 | stmt = bsi_stmt (bsi); | |
1228 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
1229 | break; | |
1230 | if (!DECL_ARTIFICIAL (LABEL_EXPR_LABEL (stmt))) | |
1231 | return false; | |
1232 | } | |
1233 | ||
2b271002 ZD |
1234 | /* Protect the loop latches. */ |
1235 | if (current_loops | |
1236 | && b->loop_father->latch == b) | |
1237 | return false; | |
1238 | ||
6de9cd9a DN |
1239 | return true; |
1240 | } | |
1241 | ||
38965eb2 ZD |
1242 | /* Replaces all uses of NAME by VAL. */ |
1243 | ||
684aaf29 | 1244 | void |
38965eb2 ZD |
1245 | replace_uses_by (tree name, tree val) |
1246 | { | |
1247 | imm_use_iterator imm_iter; | |
1248 | use_operand_p use; | |
1249 | tree stmt; | |
1250 | edge e; | |
1251 | unsigned i; | |
1252 | VEC(tree,heap) *stmts = VEC_alloc (tree, heap, 20); | |
1253 | ||
1254 | FOR_EACH_IMM_USE_SAFE (use, imm_iter, name) | |
1255 | { | |
1256 | stmt = USE_STMT (use); | |
2360a4c1 | 1257 | replace_exp (use, val); |
38965eb2 ZD |
1258 | |
1259 | if (TREE_CODE (stmt) == PHI_NODE) | |
1260 | { | |
1261 | e = PHI_ARG_EDGE (stmt, PHI_ARG_INDEX_FROM_USE (use)); | |
1262 | if (e->flags & EDGE_ABNORMAL) | |
1263 | { | |
1264 | /* This can only occur for virtual operands, since | |
1265 | for the real ones SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name)) | |
1266 | would prevent replacement. */ | |
1267 | gcc_assert (!is_gimple_reg (name)); | |
1268 | SSA_NAME_OCCURS_IN_ABNORMAL_PHI (val) = 1; | |
1269 | } | |
1270 | } | |
1271 | else | |
1272 | VEC_safe_push (tree, heap, stmts, stmt); | |
1273 | } | |
1274 | ||
1275 | /* We do not update the statements in the loop above. Consider | |
1276 | x = w * w; | |
1277 | ||
1278 | If we performed the update in the first loop, the statement | |
128a79fb | 1279 | would be rescanned after first occurrence of w is replaced, |
38965eb2 ZD |
1280 | the new uses would be placed to the beginning of the list, |
1281 | and we would never process them. */ | |
1282 | for (i = 0; VEC_iterate (tree, stmts, i, stmt); i++) | |
1283 | { | |
9af0df6b JL |
1284 | tree rhs; |
1285 | ||
38965eb2 | 1286 | fold_stmt_inplace (stmt); |
9af0df6b JL |
1287 | |
1288 | rhs = get_rhs (stmt); | |
1289 | if (TREE_CODE (rhs) == ADDR_EXPR) | |
127203ac | 1290 | recompute_tree_invariant_for_addr_expr (rhs); |
9af0df6b | 1291 | |
43ec2467 | 1292 | maybe_clean_or_replace_eh_stmt (stmt, stmt); |
c4f548b8 | 1293 | mark_new_vars_to_rename (stmt); |
38965eb2 ZD |
1294 | } |
1295 | ||
1296 | VEC_free (tree, heap, stmts); | |
d5ab5675 ZD |
1297 | |
1298 | /* Also update the trees stored in loop structures. */ | |
1299 | if (current_loops) | |
1300 | { | |
1301 | struct loop *loop; | |
1302 | ||
1303 | for (i = 0; i < current_loops->num; i++) | |
1304 | { | |
1305 | loop = current_loops->parray[i]; | |
1306 | if (loop) | |
1307 | substitute_in_loop_info (loop, name, val); | |
1308 | } | |
1309 | } | |
38965eb2 | 1310 | } |
6de9cd9a DN |
1311 | |
1312 | /* Merge block B into block A. */ | |
1313 | ||
1314 | static void | |
1315 | tree_merge_blocks (basic_block a, basic_block b) | |
1316 | { | |
1317 | block_stmt_iterator bsi; | |
1318 | tree_stmt_iterator last; | |
38965eb2 | 1319 | tree phi; |
6de9cd9a DN |
1320 | |
1321 | if (dump_file) | |
1322 | fprintf (dump_file, "Merging blocks %d and %d\n", a->index, b->index); | |
1323 | ||
c4f548b8 DN |
1324 | /* Remove all single-valued PHI nodes from block B of the form |
1325 | V_i = PHI <V_j> by propagating V_j to all the uses of V_i. */ | |
38965eb2 ZD |
1326 | bsi = bsi_last (a); |
1327 | for (phi = phi_nodes (b); phi; phi = phi_nodes (b)) | |
1328 | { | |
1329 | tree def = PHI_RESULT (phi), use = PHI_ARG_DEF (phi, 0); | |
1330 | tree copy; | |
d7f0e25c ZD |
1331 | bool may_replace_uses = may_propagate_copy (def, use); |
1332 | ||
1333 | /* In case we have loops to care about, do not propagate arguments of | |
1334 | loop closed ssa phi nodes. */ | |
1335 | if (current_loops | |
1336 | && is_gimple_reg (def) | |
1337 | && TREE_CODE (use) == SSA_NAME | |
1338 | && a->loop_father != b->loop_father) | |
1339 | may_replace_uses = false; | |
1340 | ||
1341 | if (!may_replace_uses) | |
38965eb2 ZD |
1342 | { |
1343 | gcc_assert (is_gimple_reg (def)); | |
1344 | ||
128a79fb | 1345 | /* Note that just emitting the copies is fine -- there is no problem |
38965eb2 ZD |
1346 | with ordering of phi nodes. This is because A is the single |
1347 | predecessor of B, therefore results of the phi nodes cannot | |
1348 | appear as arguments of the phi nodes. */ | |
1349 | copy = build2 (MODIFY_EXPR, void_type_node, def, use); | |
1350 | bsi_insert_after (&bsi, copy, BSI_NEW_STMT); | |
1351 | SET_PHI_RESULT (phi, NULL_TREE); | |
1352 | SSA_NAME_DEF_STMT (def) = copy; | |
1353 | } | |
1354 | else | |
1355 | replace_uses_by (def, use); | |
c4f548b8 | 1356 | |
38965eb2 ZD |
1357 | remove_phi_node (phi, NULL); |
1358 | } | |
1359 | ||
6de9cd9a DN |
1360 | /* Ensure that B follows A. */ |
1361 | move_block_after (b, a); | |
1362 | ||
c5cbcccf | 1363 | gcc_assert (single_succ_edge (a)->flags & EDGE_FALLTHRU); |
1e128c5f | 1364 | gcc_assert (!last_stmt (a) || !stmt_ends_bb_p (last_stmt (a))); |
6de9cd9a DN |
1365 | |
1366 | /* Remove labels from B and set bb_for_stmt to A for other statements. */ | |
1367 | for (bsi = bsi_start (b); !bsi_end_p (bsi);) | |
1368 | { | |
1369 | if (TREE_CODE (bsi_stmt (bsi)) == LABEL_EXPR) | |
be477406 JL |
1370 | { |
1371 | tree label = bsi_stmt (bsi); | |
1372 | ||
736432ee | 1373 | bsi_remove (&bsi, false); |
be477406 JL |
1374 | /* Now that we can thread computed gotos, we might have |
1375 | a situation where we have a forced label in block B | |
1376 | However, the label at the start of block B might still be | |
1377 | used in other ways (think about the runtime checking for | |
1378 | Fortran assigned gotos). So we can not just delete the | |
1379 | label. Instead we move the label to the start of block A. */ | |
1380 | if (FORCED_LABEL (LABEL_EXPR_LABEL (label))) | |
1381 | { | |
1382 | block_stmt_iterator dest_bsi = bsi_start (a); | |
1383 | bsi_insert_before (&dest_bsi, label, BSI_NEW_STMT); | |
1384 | } | |
1385 | } | |
6de9cd9a DN |
1386 | else |
1387 | { | |
1388 | set_bb_for_stmt (bsi_stmt (bsi), a); | |
1389 | bsi_next (&bsi); | |
1390 | } | |
1391 | } | |
1392 | ||
1393 | /* Merge the chains. */ | |
1394 | last = tsi_last (a->stmt_list); | |
1395 | tsi_link_after (&last, b->stmt_list, TSI_NEW_STMT); | |
1396 | b->stmt_list = NULL; | |
1397 | } | |
1398 | ||
1399 | ||
bc23502b PB |
1400 | /* Return the one of two successors of BB that is not reachable by a |
1401 | reached by a complex edge, if there is one. Else, return BB. We use | |
1402 | this in optimizations that use post-dominators for their heuristics, | |
1403 | to catch the cases in C++ where function calls are involved. */ | |
1404 | ||
1405 | basic_block | |
1406 | single_noncomplex_succ (basic_block bb) | |
1407 | { | |
1408 | edge e0, e1; | |
1409 | if (EDGE_COUNT (bb->succs) != 2) | |
1410 | return bb; | |
1411 | ||
1412 | e0 = EDGE_SUCC (bb, 0); | |
1413 | e1 = EDGE_SUCC (bb, 1); | |
1414 | if (e0->flags & EDGE_COMPLEX) | |
1415 | return e1->dest; | |
1416 | if (e1->flags & EDGE_COMPLEX) | |
1417 | return e0->dest; | |
1418 | ||
1419 | return bb; | |
1420 | } | |
1421 | ||
1422 | ||
1423 | ||
6de9cd9a DN |
1424 | /* Walk the function tree removing unnecessary statements. |
1425 | ||
1426 | * Empty statement nodes are removed | |
1427 | ||
1428 | * Unnecessary TRY_FINALLY and TRY_CATCH blocks are removed | |
1429 | ||
1430 | * Unnecessary COND_EXPRs are removed | |
1431 | ||
1432 | * Some unnecessary BIND_EXPRs are removed | |
1433 | ||
1434 | Clearly more work could be done. The trick is doing the analysis | |
1435 | and removal fast enough to be a net improvement in compile times. | |
1436 | ||
1437 | Note that when we remove a control structure such as a COND_EXPR | |
1438 | BIND_EXPR, or TRY block, we will need to repeat this optimization pass | |
1439 | to ensure we eliminate all the useless code. */ | |
1440 | ||
1441 | struct rus_data | |
1442 | { | |
1443 | tree *last_goto; | |
1444 | bool repeat; | |
1445 | bool may_throw; | |
1446 | bool may_branch; | |
1447 | bool has_label; | |
1448 | }; | |
1449 | ||
1450 | static void remove_useless_stmts_1 (tree *, struct rus_data *); | |
1451 | ||
1452 | static bool | |
1453 | remove_useless_stmts_warn_notreached (tree stmt) | |
1454 | { | |
9506ac2b | 1455 | if (EXPR_HAS_LOCATION (stmt)) |
6de9cd9a | 1456 | { |
9506ac2b | 1457 | location_t loc = EXPR_LOCATION (stmt); |
43e05e45 SB |
1458 | if (LOCATION_LINE (loc) > 0) |
1459 | { | |
d4ee4d25 | 1460 | warning (0, "%Hwill never be executed", &loc); |
43e05e45 SB |
1461 | return true; |
1462 | } | |
6de9cd9a DN |
1463 | } |
1464 | ||
1465 | switch (TREE_CODE (stmt)) | |
1466 | { | |
1467 | case STATEMENT_LIST: | |
1468 | { | |
1469 | tree_stmt_iterator i; | |
1470 | for (i = tsi_start (stmt); !tsi_end_p (i); tsi_next (&i)) | |
1471 | if (remove_useless_stmts_warn_notreached (tsi_stmt (i))) | |
1472 | return true; | |
1473 | } | |
1474 | break; | |
1475 | ||
1476 | case COND_EXPR: | |
1477 | if (remove_useless_stmts_warn_notreached (COND_EXPR_COND (stmt))) | |
1478 | return true; | |
1479 | if (remove_useless_stmts_warn_notreached (COND_EXPR_THEN (stmt))) | |
1480 | return true; | |
1481 | if (remove_useless_stmts_warn_notreached (COND_EXPR_ELSE (stmt))) | |
1482 | return true; | |
1483 | break; | |
1484 | ||
1485 | case TRY_FINALLY_EXPR: | |
1486 | case TRY_CATCH_EXPR: | |
1487 | if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 0))) | |
1488 | return true; | |
1489 | if (remove_useless_stmts_warn_notreached (TREE_OPERAND (stmt, 1))) | |
1490 | return true; | |
1491 | break; | |
1492 | ||
1493 | case CATCH_EXPR: | |
1494 | return remove_useless_stmts_warn_notreached (CATCH_BODY (stmt)); | |
1495 | case EH_FILTER_EXPR: | |
1496 | return remove_useless_stmts_warn_notreached (EH_FILTER_FAILURE (stmt)); | |
1497 | case BIND_EXPR: | |
1498 | return remove_useless_stmts_warn_notreached (BIND_EXPR_BLOCK (stmt)); | |
1499 | ||
1500 | default: | |
1501 | /* Not a live container. */ | |
1502 | break; | |
1503 | } | |
1504 | ||
1505 | return false; | |
1506 | } | |
1507 | ||
1508 | static void | |
1509 | remove_useless_stmts_cond (tree *stmt_p, struct rus_data *data) | |
1510 | { | |
1511 | tree then_clause, else_clause, cond; | |
1512 | bool save_has_label, then_has_label, else_has_label; | |
1513 | ||
1514 | save_has_label = data->has_label; | |
1515 | data->has_label = false; | |
1516 | data->last_goto = NULL; | |
1517 | ||
1518 | remove_useless_stmts_1 (&COND_EXPR_THEN (*stmt_p), data); | |
1519 | ||
1520 | then_has_label = data->has_label; | |
1521 | data->has_label = false; | |
1522 | data->last_goto = NULL; | |
1523 | ||
1524 | remove_useless_stmts_1 (&COND_EXPR_ELSE (*stmt_p), data); | |
1525 | ||
1526 | else_has_label = data->has_label; | |
1527 | data->has_label = save_has_label | then_has_label | else_has_label; | |
1528 | ||
6de9cd9a DN |
1529 | then_clause = COND_EXPR_THEN (*stmt_p); |
1530 | else_clause = COND_EXPR_ELSE (*stmt_p); | |
18faa5da | 1531 | cond = fold (COND_EXPR_COND (*stmt_p)); |
6de9cd9a DN |
1532 | |
1533 | /* If neither arm does anything at all, we can remove the whole IF. */ | |
1534 | if (!TREE_SIDE_EFFECTS (then_clause) && !TREE_SIDE_EFFECTS (else_clause)) | |
1535 | { | |
1536 | *stmt_p = build_empty_stmt (); | |
1537 | data->repeat = true; | |
1538 | } | |
1539 | ||
1540 | /* If there are no reachable statements in an arm, then we can | |
1541 | zap the entire conditional. */ | |
1542 | else if (integer_nonzerop (cond) && !else_has_label) | |
1543 | { | |
1544 | if (warn_notreached) | |
1545 | remove_useless_stmts_warn_notreached (else_clause); | |
1546 | *stmt_p = then_clause; | |
1547 | data->repeat = true; | |
1548 | } | |
1549 | else if (integer_zerop (cond) && !then_has_label) | |
1550 | { | |
1551 | if (warn_notreached) | |
1552 | remove_useless_stmts_warn_notreached (then_clause); | |
1553 | *stmt_p = else_clause; | |
1554 | data->repeat = true; | |
1555 | } | |
1556 | ||
1557 | /* Check a couple of simple things on then/else with single stmts. */ | |
1558 | else | |
1559 | { | |
1560 | tree then_stmt = expr_only (then_clause); | |
1561 | tree else_stmt = expr_only (else_clause); | |
1562 | ||
1563 | /* Notice branches to a common destination. */ | |
1564 | if (then_stmt && else_stmt | |
1565 | && TREE_CODE (then_stmt) == GOTO_EXPR | |
1566 | && TREE_CODE (else_stmt) == GOTO_EXPR | |
1567 | && (GOTO_DESTINATION (then_stmt) == GOTO_DESTINATION (else_stmt))) | |
1568 | { | |
1569 | *stmt_p = then_stmt; | |
1570 | data->repeat = true; | |
1571 | } | |
1572 | ||
1573 | /* If the THEN/ELSE clause merely assigns a value to a variable or | |
1574 | parameter which is already known to contain that value, then | |
1575 | remove the useless THEN/ELSE clause. */ | |
1576 | else if (TREE_CODE (cond) == VAR_DECL || TREE_CODE (cond) == PARM_DECL) | |
1577 | { | |
1578 | if (else_stmt | |
1579 | && TREE_CODE (else_stmt) == MODIFY_EXPR | |
1580 | && TREE_OPERAND (else_stmt, 0) == cond | |
1581 | && integer_zerop (TREE_OPERAND (else_stmt, 1))) | |
1582 | COND_EXPR_ELSE (*stmt_p) = alloc_stmt_list (); | |
1583 | } | |
1584 | else if ((TREE_CODE (cond) == EQ_EXPR || TREE_CODE (cond) == NE_EXPR) | |
1585 | && (TREE_CODE (TREE_OPERAND (cond, 0)) == VAR_DECL | |
1586 | || TREE_CODE (TREE_OPERAND (cond, 0)) == PARM_DECL) | |
1587 | && TREE_CONSTANT (TREE_OPERAND (cond, 1))) | |
1588 | { | |
1589 | tree stmt = (TREE_CODE (cond) == EQ_EXPR | |
1590 | ? then_stmt : else_stmt); | |
1591 | tree *location = (TREE_CODE (cond) == EQ_EXPR | |
1592 | ? &COND_EXPR_THEN (*stmt_p) | |
1593 | : &COND_EXPR_ELSE (*stmt_p)); | |
1594 | ||
1595 | if (stmt | |
1596 | && TREE_CODE (stmt) == MODIFY_EXPR | |
1597 | && TREE_OPERAND (stmt, 0) == TREE_OPERAND (cond, 0) | |
1598 | && TREE_OPERAND (stmt, 1) == TREE_OPERAND (cond, 1)) | |
1599 | *location = alloc_stmt_list (); | |
1600 | } | |
1601 | } | |
1602 | ||
1603 | /* Protect GOTOs in the arm of COND_EXPRs from being removed. They | |
1604 | would be re-introduced during lowering. */ | |
1605 | data->last_goto = NULL; | |
1606 | } | |
1607 | ||
1608 | ||
1609 | static void | |
1610 | remove_useless_stmts_tf (tree *stmt_p, struct rus_data *data) | |
1611 | { | |
1612 | bool save_may_branch, save_may_throw; | |
1613 | bool this_may_branch, this_may_throw; | |
1614 | ||
1615 | /* Collect may_branch and may_throw information for the body only. */ | |
1616 | save_may_branch = data->may_branch; | |
1617 | save_may_throw = data->may_throw; | |
1618 | data->may_branch = false; | |
1619 | data->may_throw = false; | |
1620 | data->last_goto = NULL; | |
1621 | ||
1622 | remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data); | |
1623 | ||
1624 | this_may_branch = data->may_branch; | |
1625 | this_may_throw = data->may_throw; | |
1626 | data->may_branch |= save_may_branch; | |
1627 | data->may_throw |= save_may_throw; | |
1628 | data->last_goto = NULL; | |
1629 | ||
1630 | remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data); | |
1631 | ||
1632 | /* If the body is empty, then we can emit the FINALLY block without | |
1633 | the enclosing TRY_FINALLY_EXPR. */ | |
1634 | if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 0))) | |
1635 | { | |
1636 | *stmt_p = TREE_OPERAND (*stmt_p, 1); | |
1637 | data->repeat = true; | |
1638 | } | |
1639 | ||
1640 | /* If the handler is empty, then we can emit the TRY block without | |
1641 | the enclosing TRY_FINALLY_EXPR. */ | |
1642 | else if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1))) | |
1643 | { | |
1644 | *stmt_p = TREE_OPERAND (*stmt_p, 0); | |
1645 | data->repeat = true; | |
1646 | } | |
1647 | ||
1648 | /* If the body neither throws, nor branches, then we can safely | |
1649 | string the TRY and FINALLY blocks together. */ | |
1650 | else if (!this_may_branch && !this_may_throw) | |
1651 | { | |
1652 | tree stmt = *stmt_p; | |
1653 | *stmt_p = TREE_OPERAND (stmt, 0); | |
1654 | append_to_statement_list (TREE_OPERAND (stmt, 1), stmt_p); | |
1655 | data->repeat = true; | |
1656 | } | |
1657 | } | |
1658 | ||
1659 | ||
1660 | static void | |
1661 | remove_useless_stmts_tc (tree *stmt_p, struct rus_data *data) | |
1662 | { | |
1663 | bool save_may_throw, this_may_throw; | |
1664 | tree_stmt_iterator i; | |
1665 | tree stmt; | |
1666 | ||
1667 | /* Collect may_throw information for the body only. */ | |
1668 | save_may_throw = data->may_throw; | |
1669 | data->may_throw = false; | |
1670 | data->last_goto = NULL; | |
1671 | ||
1672 | remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 0), data); | |
1673 | ||
1674 | this_may_throw = data->may_throw; | |
1675 | data->may_throw = save_may_throw; | |
1676 | ||
1677 | /* If the body cannot throw, then we can drop the entire TRY_CATCH_EXPR. */ | |
1678 | if (!this_may_throw) | |
1679 | { | |
1680 | if (warn_notreached) | |
1681 | remove_useless_stmts_warn_notreached (TREE_OPERAND (*stmt_p, 1)); | |
1682 | *stmt_p = TREE_OPERAND (*stmt_p, 0); | |
1683 | data->repeat = true; | |
1684 | return; | |
1685 | } | |
1686 | ||
1687 | /* Process the catch clause specially. We may be able to tell that | |
1688 | no exceptions propagate past this point. */ | |
1689 | ||
1690 | this_may_throw = true; | |
1691 | i = tsi_start (TREE_OPERAND (*stmt_p, 1)); | |
1692 | stmt = tsi_stmt (i); | |
1693 | data->last_goto = NULL; | |
1694 | ||
1695 | switch (TREE_CODE (stmt)) | |
1696 | { | |
1697 | case CATCH_EXPR: | |
1698 | for (; !tsi_end_p (i); tsi_next (&i)) | |
1699 | { | |
1700 | stmt = tsi_stmt (i); | |
1701 | /* If we catch all exceptions, then the body does not | |
1702 | propagate exceptions past this point. */ | |
1703 | if (CATCH_TYPES (stmt) == NULL) | |
1704 | this_may_throw = false; | |
1705 | data->last_goto = NULL; | |
1706 | remove_useless_stmts_1 (&CATCH_BODY (stmt), data); | |
1707 | } | |
1708 | break; | |
1709 | ||
1710 | case EH_FILTER_EXPR: | |
1711 | if (EH_FILTER_MUST_NOT_THROW (stmt)) | |
1712 | this_may_throw = false; | |
1713 | else if (EH_FILTER_TYPES (stmt) == NULL) | |
1714 | this_may_throw = false; | |
1715 | remove_useless_stmts_1 (&EH_FILTER_FAILURE (stmt), data); | |
1716 | break; | |
1717 | ||
1718 | default: | |
1719 | /* Otherwise this is a cleanup. */ | |
1720 | remove_useless_stmts_1 (&TREE_OPERAND (*stmt_p, 1), data); | |
1721 | ||
1722 | /* If the cleanup is empty, then we can emit the TRY block without | |
1723 | the enclosing TRY_CATCH_EXPR. */ | |
1724 | if (!TREE_SIDE_EFFECTS (TREE_OPERAND (*stmt_p, 1))) | |
1725 | { | |
1726 | *stmt_p = TREE_OPERAND (*stmt_p, 0); | |
1727 | data->repeat = true; | |
1728 | } | |
1729 | break; | |
1730 | } | |
1731 | data->may_throw |= this_may_throw; | |
1732 | } | |
1733 | ||
1734 | ||
1735 | static void | |
1736 | remove_useless_stmts_bind (tree *stmt_p, struct rus_data *data) | |
1737 | { | |
1738 | tree block; | |
1739 | ||
1740 | /* First remove anything underneath the BIND_EXPR. */ | |
1741 | remove_useless_stmts_1 (&BIND_EXPR_BODY (*stmt_p), data); | |
1742 | ||
1743 | /* If the BIND_EXPR has no variables, then we can pull everything | |
1744 | up one level and remove the BIND_EXPR, unless this is the toplevel | |
1745 | BIND_EXPR for the current function or an inlined function. | |
1746 | ||
1747 | When this situation occurs we will want to apply this | |
1748 | optimization again. */ | |
1749 | block = BIND_EXPR_BLOCK (*stmt_p); | |
1750 | if (BIND_EXPR_VARS (*stmt_p) == NULL_TREE | |
1751 | && *stmt_p != DECL_SAVED_TREE (current_function_decl) | |
1752 | && (! block | |
1753 | || ! BLOCK_ABSTRACT_ORIGIN (block) | |
1754 | || (TREE_CODE (BLOCK_ABSTRACT_ORIGIN (block)) | |
1755 | != FUNCTION_DECL))) | |
1756 | { | |
1757 | *stmt_p = BIND_EXPR_BODY (*stmt_p); | |
1758 | data->repeat = true; | |
1759 | } | |
1760 | } | |
1761 | ||
1762 | ||
1763 | static void | |
1764 | remove_useless_stmts_goto (tree *stmt_p, struct rus_data *data) | |
1765 | { | |
1766 | tree dest = GOTO_DESTINATION (*stmt_p); | |
1767 | ||
1768 | data->may_branch = true; | |
1769 | data->last_goto = NULL; | |
1770 | ||
1771 | /* Record the last goto expr, so that we can delete it if unnecessary. */ | |
1772 | if (TREE_CODE (dest) == LABEL_DECL) | |
1773 | data->last_goto = stmt_p; | |
1774 | } | |
1775 | ||
1776 | ||
1777 | static void | |
1778 | remove_useless_stmts_label (tree *stmt_p, struct rus_data *data) | |
1779 | { | |
1780 | tree label = LABEL_EXPR_LABEL (*stmt_p); | |
1781 | ||
1782 | data->has_label = true; | |
1783 | ||
1784 | /* We do want to jump across non-local label receiver code. */ | |
1785 | if (DECL_NONLOCAL (label)) | |
1786 | data->last_goto = NULL; | |
1787 | ||
1788 | else if (data->last_goto && GOTO_DESTINATION (*data->last_goto) == label) | |
1789 | { | |
1790 | *data->last_goto = build_empty_stmt (); | |
1791 | data->repeat = true; | |
1792 | } | |
1793 | ||
1794 | /* ??? Add something here to delete unused labels. */ | |
1795 | } | |
1796 | ||
1797 | ||
1798 | /* If the function is "const" or "pure", then clear TREE_SIDE_EFFECTS on its | |
1799 | decl. This allows us to eliminate redundant or useless | |
1800 | calls to "const" functions. | |
1801 | ||
1802 | Gimplifier already does the same operation, but we may notice functions | |
1803 | being const and pure once their calls has been gimplified, so we need | |
1804 | to update the flag. */ | |
1805 | ||
1806 | static void | |
1807 | update_call_expr_flags (tree call) | |
1808 | { | |
1809 | tree decl = get_callee_fndecl (call); | |
1810 | if (!decl) | |
1811 | return; | |
1812 | if (call_expr_flags (call) & (ECF_CONST | ECF_PURE)) | |
1813 | TREE_SIDE_EFFECTS (call) = 0; | |
1814 | if (TREE_NOTHROW (decl)) | |
1815 | TREE_NOTHROW (call) = 1; | |
1816 | } | |
1817 | ||
1818 | ||
1819 | /* T is CALL_EXPR. Set current_function_calls_* flags. */ | |
1820 | ||
1821 | void | |
1822 | notice_special_calls (tree t) | |
1823 | { | |
1824 | int flags = call_expr_flags (t); | |
1825 | ||
1826 | if (flags & ECF_MAY_BE_ALLOCA) | |
1827 | current_function_calls_alloca = true; | |
1828 | if (flags & ECF_RETURNS_TWICE) | |
1829 | current_function_calls_setjmp = true; | |
1830 | } | |
1831 | ||
1832 | ||
1833 | /* Clear flags set by notice_special_calls. Used by dead code removal | |
1834 | to update the flags. */ | |
1835 | ||
1836 | void | |
1837 | clear_special_calls (void) | |
1838 | { | |
1839 | current_function_calls_alloca = false; | |
1840 | current_function_calls_setjmp = false; | |
1841 | } | |
1842 | ||
1843 | ||
1844 | static void | |
1845 | remove_useless_stmts_1 (tree *tp, struct rus_data *data) | |
1846 | { | |
cd709752 | 1847 | tree t = *tp, op; |
6de9cd9a DN |
1848 | |
1849 | switch (TREE_CODE (t)) | |
1850 | { | |
1851 | case COND_EXPR: | |
1852 | remove_useless_stmts_cond (tp, data); | |
1853 | break; | |
1854 | ||
1855 | case TRY_FINALLY_EXPR: | |
1856 | remove_useless_stmts_tf (tp, data); | |
1857 | break; | |
1858 | ||
1859 | case TRY_CATCH_EXPR: | |
1860 | remove_useless_stmts_tc (tp, data); | |
1861 | break; | |
1862 | ||
1863 | case BIND_EXPR: | |
1864 | remove_useless_stmts_bind (tp, data); | |
1865 | break; | |
1866 | ||
1867 | case GOTO_EXPR: | |
1868 | remove_useless_stmts_goto (tp, data); | |
1869 | break; | |
1870 | ||
1871 | case LABEL_EXPR: | |
1872 | remove_useless_stmts_label (tp, data); | |
1873 | break; | |
1874 | ||
1875 | case RETURN_EXPR: | |
53e782e5 | 1876 | fold_stmt (tp); |
6de9cd9a DN |
1877 | data->last_goto = NULL; |
1878 | data->may_branch = true; | |
1879 | break; | |
1880 | ||
1881 | case CALL_EXPR: | |
53e782e5 | 1882 | fold_stmt (tp); |
6de9cd9a DN |
1883 | data->last_goto = NULL; |
1884 | notice_special_calls (t); | |
1885 | update_call_expr_flags (t); | |
1886 | if (tree_could_throw_p (t)) | |
1887 | data->may_throw = true; | |
1888 | break; | |
1889 | ||
1890 | case MODIFY_EXPR: | |
1891 | data->last_goto = NULL; | |
53e782e5 | 1892 | fold_stmt (tp); |
cd709752 RH |
1893 | op = get_call_expr_in (t); |
1894 | if (op) | |
6de9cd9a | 1895 | { |
cd709752 RH |
1896 | update_call_expr_flags (op); |
1897 | notice_special_calls (op); | |
6de9cd9a DN |
1898 | } |
1899 | if (tree_could_throw_p (t)) | |
1900 | data->may_throw = true; | |
1901 | break; | |
1902 | ||
1903 | case STATEMENT_LIST: | |
1904 | { | |
1905 | tree_stmt_iterator i = tsi_start (t); | |
1906 | while (!tsi_end_p (i)) | |
1907 | { | |
1908 | t = tsi_stmt (i); | |
1909 | if (IS_EMPTY_STMT (t)) | |
1910 | { | |
1911 | tsi_delink (&i); | |
1912 | continue; | |
1913 | } | |
1914 | ||
1915 | remove_useless_stmts_1 (tsi_stmt_ptr (i), data); | |
1916 | ||
1917 | t = tsi_stmt (i); | |
1918 | if (TREE_CODE (t) == STATEMENT_LIST) | |
1919 | { | |
1920 | tsi_link_before (&i, t, TSI_SAME_STMT); | |
1921 | tsi_delink (&i); | |
1922 | } | |
1923 | else | |
1924 | tsi_next (&i); | |
1925 | } | |
1926 | } | |
1927 | break; | |
8e14584d | 1928 | case ASM_EXPR: |
53e782e5 AP |
1929 | fold_stmt (tp); |
1930 | data->last_goto = NULL; | |
1931 | break; | |
6de9cd9a DN |
1932 | |
1933 | default: | |
1934 | data->last_goto = NULL; | |
1935 | break; | |
1936 | } | |
1937 | } | |
1938 | ||
c2924966 | 1939 | static unsigned int |
6de9cd9a DN |
1940 | remove_useless_stmts (void) |
1941 | { | |
1942 | struct rus_data data; | |
1943 | ||
1944 | clear_special_calls (); | |
1945 | ||
1946 | do | |
1947 | { | |
1948 | memset (&data, 0, sizeof (data)); | |
1949 | remove_useless_stmts_1 (&DECL_SAVED_TREE (current_function_decl), &data); | |
1950 | } | |
1951 | while (data.repeat); | |
c2924966 | 1952 | return 0; |
6de9cd9a DN |
1953 | } |
1954 | ||
1955 | ||
1956 | struct tree_opt_pass pass_remove_useless_stmts = | |
1957 | { | |
1958 | "useless", /* name */ | |
1959 | NULL, /* gate */ | |
1960 | remove_useless_stmts, /* execute */ | |
1961 | NULL, /* sub */ | |
1962 | NULL, /* next */ | |
1963 | 0, /* static_pass_number */ | |
1964 | 0, /* tv_id */ | |
9e5a3e6c RH |
1965 | PROP_gimple_any, /* properties_required */ |
1966 | 0, /* properties_provided */ | |
6de9cd9a DN |
1967 | 0, /* properties_destroyed */ |
1968 | 0, /* todo_flags_start */ | |
9f8628ba PB |
1969 | TODO_dump_func, /* todo_flags_finish */ |
1970 | 0 /* letter */ | |
6de9cd9a DN |
1971 | }; |
1972 | ||
6de9cd9a DN |
1973 | /* Remove PHI nodes associated with basic block BB and all edges out of BB. */ |
1974 | ||
1975 | static void | |
1976 | remove_phi_nodes_and_edges_for_unreachable_block (basic_block bb) | |
1977 | { | |
1978 | tree phi; | |
1979 | ||
1980 | /* Since this block is no longer reachable, we can just delete all | |
1981 | of its PHI nodes. */ | |
1982 | phi = phi_nodes (bb); | |
1983 | while (phi) | |
1984 | { | |
17192884 | 1985 | tree next = PHI_CHAIN (phi); |
d19e3ef6 | 1986 | remove_phi_node (phi, NULL_TREE); |
6de9cd9a DN |
1987 | phi = next; |
1988 | } | |
1989 | ||
1990 | /* Remove edges to BB's successors. */ | |
628f6a4e | 1991 | while (EDGE_COUNT (bb->succs) > 0) |
d0d2cc21 | 1992 | remove_edge (EDGE_SUCC (bb, 0)); |
6de9cd9a DN |
1993 | } |
1994 | ||
1995 | ||
1996 | /* Remove statements of basic block BB. */ | |
1997 | ||
1998 | static void | |
1999 | remove_bb (basic_block bb) | |
2000 | { | |
2001 | block_stmt_iterator i; | |
dbce1570 PB |
2002 | #ifdef USE_MAPPED_LOCATION |
2003 | source_location loc = UNKNOWN_LOCATION; | |
2004 | #else | |
9506ac2b | 2005 | source_locus loc = 0; |
dbce1570 | 2006 | #endif |
6de9cd9a DN |
2007 | |
2008 | if (dump_file) | |
2009 | { | |
2010 | fprintf (dump_file, "Removing basic block %d\n", bb->index); | |
2011 | if (dump_flags & TDF_DETAILS) | |
2012 | { | |
2013 | dump_bb (bb, dump_file, 0); | |
2014 | fprintf (dump_file, "\n"); | |
2015 | } | |
2016 | } | |
2017 | ||
2b271002 ZD |
2018 | /* If we remove the header or the latch of a loop, mark the loop for |
2019 | removal by setting its header and latch to NULL. */ | |
2020 | if (current_loops) | |
2021 | { | |
2022 | struct loop *loop = bb->loop_father; | |
2023 | ||
2024 | if (loop->latch == bb | |
2025 | || loop->header == bb) | |
2026 | { | |
2027 | loop->latch = NULL; | |
2028 | loop->header = NULL; | |
c9639aae ZD |
2029 | |
2030 | /* Also clean up the information associated with the loop. Updating | |
2031 | it would waste time. More importantly, it may refer to ssa | |
2032 | names that were defined in other removed basic block -- these | |
2033 | ssa names are now removed and invalid. */ | |
2034 | free_numbers_of_iterations_estimates_loop (loop); | |
2b271002 ZD |
2035 | } |
2036 | } | |
2037 | ||
6de9cd9a | 2038 | /* Remove all the instructions in the block. */ |
77568960 | 2039 | for (i = bsi_start (bb); !bsi_end_p (i);) |
6de9cd9a DN |
2040 | { |
2041 | tree stmt = bsi_stmt (i); | |
77568960 | 2042 | if (TREE_CODE (stmt) == LABEL_EXPR |
bb1ecfe8 RH |
2043 | && (FORCED_LABEL (LABEL_EXPR_LABEL (stmt)) |
2044 | || DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)))) | |
77568960 | 2045 | { |
bb1ecfe8 RH |
2046 | basic_block new_bb; |
2047 | block_stmt_iterator new_bsi; | |
2048 | ||
2049 | /* A non-reachable non-local label may still be referenced. | |
2050 | But it no longer needs to carry the extra semantics of | |
2051 | non-locality. */ | |
2052 | if (DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))) | |
2053 | { | |
2054 | DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt)) = 0; | |
2055 | FORCED_LABEL (LABEL_EXPR_LABEL (stmt)) = 1; | |
2056 | } | |
77568960 | 2057 | |
bb1ecfe8 RH |
2058 | new_bb = bb->prev_bb; |
2059 | new_bsi = bsi_start (new_bb); | |
736432ee | 2060 | bsi_remove (&i, false); |
ef0b4f28 | 2061 | bsi_insert_before (&new_bsi, stmt, BSI_NEW_STMT); |
77568960 AP |
2062 | } |
2063 | else | |
2064 | { | |
1ff54bfb KH |
2065 | /* Release SSA definitions if we are in SSA. Note that we |
2066 | may be called when not in SSA. For example, | |
2067 | final_cleanup calls this function via | |
2068 | cleanup_tree_cfg. */ | |
2069 | if (in_ssa_p) | |
2070 | release_defs (stmt); | |
6de9cd9a | 2071 | |
736432ee | 2072 | bsi_remove (&i, true); |
77568960 | 2073 | } |
6de9cd9a DN |
2074 | |
2075 | /* Don't warn for removed gotos. Gotos are often removed due to | |
2076 | jump threading, thus resulting in bogus warnings. Not great, | |
2077 | since this way we lose warnings for gotos in the original | |
2078 | program that are indeed unreachable. */ | |
9506ac2b | 2079 | if (TREE_CODE (stmt) != GOTO_EXPR && EXPR_HAS_LOCATION (stmt) && !loc) |
43e05e45 | 2080 | { |
9506ac2b | 2081 | #ifdef USE_MAPPED_LOCATION |
dbce1570 PB |
2082 | if (EXPR_HAS_LOCATION (stmt)) |
2083 | loc = EXPR_LOCATION (stmt); | |
9506ac2b | 2084 | #else |
dbce1570 | 2085 | source_locus t; |
43e05e45 | 2086 | t = EXPR_LOCUS (stmt); |
43e05e45 SB |
2087 | if (t && LOCATION_LINE (*t) > 0) |
2088 | loc = t; | |
dbce1570 | 2089 | #endif |
43e05e45 | 2090 | } |
6de9cd9a DN |
2091 | } |
2092 | ||
2093 | /* If requested, give a warning that the first statement in the | |
2094 | block is unreachable. We walk statements backwards in the | |
2095 | loop above, so the last statement we process is the first statement | |
2096 | in the block. */ | |
9506ac2b | 2097 | #ifdef USE_MAPPED_LOCATION |
44c21c7f DD |
2098 | if (loc > BUILTINS_LOCATION) |
2099 | warning (OPT_Wunreachable_code, "%Hwill never be executed", &loc); | |
9506ac2b | 2100 | #else |
44c21c7f DD |
2101 | if (loc) |
2102 | warning (OPT_Wunreachable_code, "%Hwill never be executed", loc); | |
9506ac2b | 2103 | #endif |
6de9cd9a DN |
2104 | |
2105 | remove_phi_nodes_and_edges_for_unreachable_block (bb); | |
2106 | } | |
2107 | ||
6de9cd9a | 2108 | |
35920270 KH |
2109 | /* Given a basic block BB ending with COND_EXPR or SWITCH_EXPR, and a |
2110 | predicate VAL, return the edge that will be taken out of the block. | |
2111 | If VAL does not match a unique edge, NULL is returned. */ | |
6de9cd9a DN |
2112 | |
2113 | edge | |
2114 | find_taken_edge (basic_block bb, tree val) | |
2115 | { | |
2116 | tree stmt; | |
2117 | ||
2118 | stmt = last_stmt (bb); | |
2119 | ||
1e128c5f GB |
2120 | gcc_assert (stmt); |
2121 | gcc_assert (is_ctrl_stmt (stmt)); | |
65f4323d | 2122 | gcc_assert (val); |
6de9cd9a | 2123 | |
be477406 | 2124 | if (! is_gimple_min_invariant (val)) |
6de9cd9a DN |
2125 | return NULL; |
2126 | ||
2127 | if (TREE_CODE (stmt) == COND_EXPR) | |
2128 | return find_taken_edge_cond_expr (bb, val); | |
2129 | ||
2130 | if (TREE_CODE (stmt) == SWITCH_EXPR) | |
2131 | return find_taken_edge_switch_expr (bb, val); | |
2132 | ||
be477406 JL |
2133 | if (computed_goto_p (stmt)) |
2134 | return find_taken_edge_computed_goto (bb, TREE_OPERAND( val, 0)); | |
2135 | ||
35920270 | 2136 | gcc_unreachable (); |
6de9cd9a DN |
2137 | } |
2138 | ||
be477406 JL |
2139 | /* Given a constant value VAL and the entry block BB to a GOTO_EXPR |
2140 | statement, determine which of the outgoing edges will be taken out of the | |
2141 | block. Return NULL if either edge may be taken. */ | |
2142 | ||
2143 | static edge | |
2144 | find_taken_edge_computed_goto (basic_block bb, tree val) | |
2145 | { | |
2146 | basic_block dest; | |
2147 | edge e = NULL; | |
2148 | ||
2149 | dest = label_to_block (val); | |
2150 | if (dest) | |
2151 | { | |
2152 | e = find_edge (bb, dest); | |
2153 | gcc_assert (e != NULL); | |
2154 | } | |
2155 | ||
2156 | return e; | |
2157 | } | |
6de9cd9a DN |
2158 | |
2159 | /* Given a constant value VAL and the entry block BB to a COND_EXPR | |
2160 | statement, determine which of the two edges will be taken out of the | |
2161 | block. Return NULL if either edge may be taken. */ | |
2162 | ||
2163 | static edge | |
2164 | find_taken_edge_cond_expr (basic_block bb, tree val) | |
2165 | { | |
2166 | edge true_edge, false_edge; | |
2167 | ||
2168 | extract_true_false_edges_from_block (bb, &true_edge, &false_edge); | |
f1b19062 ZD |
2169 | |
2170 | gcc_assert (TREE_CODE (val) == INTEGER_CST); | |
2171 | return (zero_p (val) ? false_edge : true_edge); | |
6de9cd9a DN |
2172 | } |
2173 | ||
fca01525 | 2174 | /* Given an INTEGER_CST VAL and the entry block BB to a SWITCH_EXPR |
6de9cd9a DN |
2175 | statement, determine which edge will be taken out of the block. Return |
2176 | NULL if any edge may be taken. */ | |
2177 | ||
2178 | static edge | |
2179 | find_taken_edge_switch_expr (basic_block bb, tree val) | |
2180 | { | |
2181 | tree switch_expr, taken_case; | |
2182 | basic_block dest_bb; | |
2183 | edge e; | |
2184 | ||
6de9cd9a DN |
2185 | switch_expr = last_stmt (bb); |
2186 | taken_case = find_case_label_for_value (switch_expr, val); | |
2187 | dest_bb = label_to_block (CASE_LABEL (taken_case)); | |
2188 | ||
2189 | e = find_edge (bb, dest_bb); | |
1e128c5f | 2190 | gcc_assert (e); |
6de9cd9a DN |
2191 | return e; |
2192 | } | |
2193 | ||
2194 | ||
f667741c SB |
2195 | /* Return the CASE_LABEL_EXPR that SWITCH_EXPR will take for VAL. |
2196 | We can make optimal use here of the fact that the case labels are | |
2197 | sorted: We can do a binary search for a case matching VAL. */ | |
6de9cd9a DN |
2198 | |
2199 | static tree | |
2200 | find_case_label_for_value (tree switch_expr, tree val) | |
2201 | { | |
2202 | tree vec = SWITCH_LABELS (switch_expr); | |
f667741c SB |
2203 | size_t low, high, n = TREE_VEC_LENGTH (vec); |
2204 | tree default_case = TREE_VEC_ELT (vec, n - 1); | |
6de9cd9a | 2205 | |
f667741c | 2206 | for (low = -1, high = n - 1; high - low > 1; ) |
6de9cd9a | 2207 | { |
f667741c | 2208 | size_t i = (high + low) / 2; |
6de9cd9a | 2209 | tree t = TREE_VEC_ELT (vec, i); |
f667741c SB |
2210 | int cmp; |
2211 | ||
2212 | /* Cache the result of comparing CASE_LOW and val. */ | |
2213 | cmp = tree_int_cst_compare (CASE_LOW (t), val); | |
6de9cd9a | 2214 | |
f667741c SB |
2215 | if (cmp > 0) |
2216 | high = i; | |
2217 | else | |
2218 | low = i; | |
2219 | ||
2220 | if (CASE_HIGH (t) == NULL) | |
6de9cd9a | 2221 | { |
f667741c SB |
2222 | /* A singe-valued case label. */ |
2223 | if (cmp == 0) | |
6de9cd9a DN |
2224 | return t; |
2225 | } | |
2226 | else | |
2227 | { | |
2228 | /* A case range. We can only handle integer ranges. */ | |
f667741c | 2229 | if (cmp <= 0 && tree_int_cst_compare (CASE_HIGH (t), val) >= 0) |
6de9cd9a DN |
2230 | return t; |
2231 | } | |
2232 | } | |
2233 | ||
6de9cd9a DN |
2234 | return default_case; |
2235 | } | |
2236 | ||
2237 | ||
6de9cd9a DN |
2238 | |
2239 | ||
6de9cd9a DN |
2240 | /*--------------------------------------------------------------------------- |
2241 | Debugging functions | |
2242 | ---------------------------------------------------------------------------*/ | |
2243 | ||
2244 | /* Dump tree-specific information of block BB to file OUTF. */ | |
2245 | ||
2246 | void | |
2247 | tree_dump_bb (basic_block bb, FILE *outf, int indent) | |
2248 | { | |
2249 | dump_generic_bb (outf, bb, indent, TDF_VOPS); | |
2250 | } | |
2251 | ||
2252 | ||
2253 | /* Dump a basic block on stderr. */ | |
2254 | ||
2255 | void | |
2256 | debug_tree_bb (basic_block bb) | |
2257 | { | |
2258 | dump_bb (bb, stderr, 0); | |
2259 | } | |
2260 | ||
2261 | ||
2262 | /* Dump basic block with index N on stderr. */ | |
2263 | ||
2264 | basic_block | |
2265 | debug_tree_bb_n (int n) | |
2266 | { | |
2267 | debug_tree_bb (BASIC_BLOCK (n)); | |
2268 | return BASIC_BLOCK (n); | |
2269 | } | |
2270 | ||
2271 | ||
2272 | /* Dump the CFG on stderr. | |
2273 | ||
2274 | FLAGS are the same used by the tree dumping functions | |
2275 | (see TDF_* in tree.h). */ | |
2276 | ||
2277 | void | |
2278 | debug_tree_cfg (int flags) | |
2279 | { | |
2280 | dump_tree_cfg (stderr, flags); | |
2281 | } | |
2282 | ||
2283 | ||
2284 | /* Dump the program showing basic block boundaries on the given FILE. | |
2285 | ||
2286 | FLAGS are the same used by the tree dumping functions (see TDF_* in | |
2287 | tree.h). */ | |
2288 | ||
2289 | void | |
2290 | dump_tree_cfg (FILE *file, int flags) | |
2291 | { | |
2292 | if (flags & TDF_DETAILS) | |
2293 | { | |
2294 | const char *funcname | |
673fda6b | 2295 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
6de9cd9a DN |
2296 | |
2297 | fputc ('\n', file); | |
2298 | fprintf (file, ";; Function %s\n\n", funcname); | |
2299 | fprintf (file, ";; \n%d basic blocks, %d edges, last basic block %d.\n\n", | |
2300 | n_basic_blocks, n_edges, last_basic_block); | |
2301 | ||
2302 | brief_dump_cfg (file); | |
2303 | fprintf (file, "\n"); | |
2304 | } | |
2305 | ||
2306 | if (flags & TDF_STATS) | |
2307 | dump_cfg_stats (file); | |
2308 | ||
2309 | dump_function_to_file (current_function_decl, file, flags | TDF_BLOCKS); | |
2310 | } | |
2311 | ||
2312 | ||
2313 | /* Dump CFG statistics on FILE. */ | |
2314 | ||
2315 | void | |
2316 | dump_cfg_stats (FILE *file) | |
2317 | { | |
2318 | static long max_num_merged_labels = 0; | |
2319 | unsigned long size, total = 0; | |
7b0cab99 | 2320 | long num_edges; |
6de9cd9a DN |
2321 | basic_block bb; |
2322 | const char * const fmt_str = "%-30s%-13s%12s\n"; | |
f7fda749 | 2323 | const char * const fmt_str_1 = "%-30s%13d%11lu%c\n"; |
cac50d94 | 2324 | const char * const fmt_str_2 = "%-30s%13ld%11lu%c\n"; |
6de9cd9a DN |
2325 | const char * const fmt_str_3 = "%-43s%11lu%c\n"; |
2326 | const char *funcname | |
673fda6b | 2327 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
6de9cd9a DN |
2328 | |
2329 | ||
2330 | fprintf (file, "\nCFG Statistics for %s\n\n", funcname); | |
2331 | ||
2332 | fprintf (file, "---------------------------------------------------------\n"); | |
2333 | fprintf (file, fmt_str, "", " Number of ", "Memory"); | |
2334 | fprintf (file, fmt_str, "", " instances ", "used "); | |
2335 | fprintf (file, "---------------------------------------------------------\n"); | |
2336 | ||
2337 | size = n_basic_blocks * sizeof (struct basic_block_def); | |
2338 | total += size; | |
f7fda749 RH |
2339 | fprintf (file, fmt_str_1, "Basic blocks", n_basic_blocks, |
2340 | SCALE (size), LABEL (size)); | |
6de9cd9a | 2341 | |
7b0cab99 | 2342 | num_edges = 0; |
6de9cd9a | 2343 | FOR_EACH_BB (bb) |
7b0cab99 JH |
2344 | num_edges += EDGE_COUNT (bb->succs); |
2345 | size = num_edges * sizeof (struct edge_def); | |
6de9cd9a | 2346 | total += size; |
cac50d94 | 2347 | fprintf (file, fmt_str_2, "Edges", num_edges, SCALE (size), LABEL (size)); |
6de9cd9a | 2348 | |
6de9cd9a DN |
2349 | fprintf (file, "---------------------------------------------------------\n"); |
2350 | fprintf (file, fmt_str_3, "Total memory used by CFG data", SCALE (total), | |
2351 | LABEL (total)); | |
2352 | fprintf (file, "---------------------------------------------------------\n"); | |
2353 | fprintf (file, "\n"); | |
2354 | ||
2355 | if (cfg_stats.num_merged_labels > max_num_merged_labels) | |
2356 | max_num_merged_labels = cfg_stats.num_merged_labels; | |
2357 | ||
2358 | fprintf (file, "Coalesced label blocks: %ld (Max so far: %ld)\n", | |
2359 | cfg_stats.num_merged_labels, max_num_merged_labels); | |
2360 | ||
2361 | fprintf (file, "\n"); | |
2362 | } | |
2363 | ||
2364 | ||
2365 | /* Dump CFG statistics on stderr. Keep extern so that it's always | |
2366 | linked in the final executable. */ | |
2367 | ||
2368 | void | |
2369 | debug_cfg_stats (void) | |
2370 | { | |
2371 | dump_cfg_stats (stderr); | |
2372 | } | |
2373 | ||
2374 | ||
2375 | /* Dump the flowgraph to a .vcg FILE. */ | |
2376 | ||
2377 | static void | |
2378 | tree_cfg2vcg (FILE *file) | |
2379 | { | |
2380 | edge e; | |
628f6a4e | 2381 | edge_iterator ei; |
6de9cd9a DN |
2382 | basic_block bb; |
2383 | const char *funcname | |
673fda6b | 2384 | = lang_hooks.decl_printable_name (current_function_decl, 2); |
6de9cd9a DN |
2385 | |
2386 | /* Write the file header. */ | |
2387 | fprintf (file, "graph: { title: \"%s\"\n", funcname); | |
2388 | fprintf (file, "node: { title: \"ENTRY\" label: \"ENTRY\" }\n"); | |
2389 | fprintf (file, "node: { title: \"EXIT\" label: \"EXIT\" }\n"); | |
2390 | ||
2391 | /* Write blocks and edges. */ | |
628f6a4e | 2392 | FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs) |
6de9cd9a DN |
2393 | { |
2394 | fprintf (file, "edge: { sourcename: \"ENTRY\" targetname: \"%d\"", | |
2395 | e->dest->index); | |
2396 | ||
2397 | if (e->flags & EDGE_FAKE) | |
2398 | fprintf (file, " linestyle: dotted priority: 10"); | |
2399 | else | |
2400 | fprintf (file, " linestyle: solid priority: 100"); | |
2401 | ||
2402 | fprintf (file, " }\n"); | |
2403 | } | |
2404 | fputc ('\n', file); | |
2405 | ||
2406 | FOR_EACH_BB (bb) | |
2407 | { | |
2408 | enum tree_code head_code, end_code; | |
2409 | const char *head_name, *end_name; | |
2410 | int head_line = 0; | |
2411 | int end_line = 0; | |
2412 | tree first = first_stmt (bb); | |
2413 | tree last = last_stmt (bb); | |
2414 | ||
2415 | if (first) | |
2416 | { | |
2417 | head_code = TREE_CODE (first); | |
2418 | head_name = tree_code_name[head_code]; | |
2419 | head_line = get_lineno (first); | |
2420 | } | |
2421 | else | |
2422 | head_name = "no-statement"; | |
2423 | ||
2424 | if (last) | |
2425 | { | |
2426 | end_code = TREE_CODE (last); | |
2427 | end_name = tree_code_name[end_code]; | |
2428 | end_line = get_lineno (last); | |
2429 | } | |
2430 | else | |
2431 | end_name = "no-statement"; | |
2432 | ||
2433 | fprintf (file, "node: { title: \"%d\" label: \"#%d\\n%s (%d)\\n%s (%d)\"}\n", | |
2434 | bb->index, bb->index, head_name, head_line, end_name, | |
2435 | end_line); | |
2436 | ||
628f6a4e | 2437 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
2438 | { |
2439 | if (e->dest == EXIT_BLOCK_PTR) | |
2440 | fprintf (file, "edge: { sourcename: \"%d\" targetname: \"EXIT\"", bb->index); | |
2441 | else | |
2442 | fprintf (file, "edge: { sourcename: \"%d\" targetname: \"%d\"", bb->index, e->dest->index); | |
2443 | ||
2444 | if (e->flags & EDGE_FAKE) | |
2445 | fprintf (file, " priority: 10 linestyle: dotted"); | |
2446 | else | |
2447 | fprintf (file, " priority: 100 linestyle: solid"); | |
2448 | ||
2449 | fprintf (file, " }\n"); | |
2450 | } | |
2451 | ||
2452 | if (bb->next_bb != EXIT_BLOCK_PTR) | |
2453 | fputc ('\n', file); | |
2454 | } | |
2455 | ||
2456 | fputs ("}\n\n", file); | |
2457 | } | |
2458 | ||
2459 | ||
2460 | ||
2461 | /*--------------------------------------------------------------------------- | |
2462 | Miscellaneous helpers | |
2463 | ---------------------------------------------------------------------------*/ | |
2464 | ||
2465 | /* Return true if T represents a stmt that always transfers control. */ | |
2466 | ||
2467 | bool | |
2468 | is_ctrl_stmt (tree t) | |
2469 | { | |
2470 | return (TREE_CODE (t) == COND_EXPR | |
2471 | || TREE_CODE (t) == SWITCH_EXPR | |
2472 | || TREE_CODE (t) == GOTO_EXPR | |
2473 | || TREE_CODE (t) == RETURN_EXPR | |
2474 | || TREE_CODE (t) == RESX_EXPR); | |
2475 | } | |
2476 | ||
2477 | ||
2478 | /* Return true if T is a statement that may alter the flow of control | |
2479 | (e.g., a call to a non-returning function). */ | |
2480 | ||
2481 | bool | |
2482 | is_ctrl_altering_stmt (tree t) | |
2483 | { | |
cd709752 | 2484 | tree call; |
6de9cd9a | 2485 | |
1e128c5f | 2486 | gcc_assert (t); |
cd709752 RH |
2487 | call = get_call_expr_in (t); |
2488 | if (call) | |
6de9cd9a | 2489 | { |
6de9cd9a DN |
2490 | /* A non-pure/const CALL_EXPR alters flow control if the current |
2491 | function has nonlocal labels. */ | |
cd709752 | 2492 | if (TREE_SIDE_EFFECTS (call) && current_function_has_nonlocal_label) |
6de9cd9a DN |
2493 | return true; |
2494 | ||
2495 | /* A CALL_EXPR also alters control flow if it does not return. */ | |
6e14af16 | 2496 | if (call_expr_flags (call) & ECF_NORETURN) |
6de9cd9a | 2497 | return true; |
6de9cd9a DN |
2498 | } |
2499 | ||
50674e96 DN |
2500 | /* OpenMP directives alter control flow. */ |
2501 | if (flag_openmp && OMP_DIRECTIVE_P (t)) | |
2502 | return true; | |
2503 | ||
6de9cd9a DN |
2504 | /* If a statement can throw, it alters control flow. */ |
2505 | return tree_can_throw_internal (t); | |
2506 | } | |
2507 | ||
2508 | ||
2509 | /* Return true if T is a computed goto. */ | |
2510 | ||
2511 | bool | |
2512 | computed_goto_p (tree t) | |
2513 | { | |
2514 | return (TREE_CODE (t) == GOTO_EXPR | |
2515 | && TREE_CODE (GOTO_DESTINATION (t)) != LABEL_DECL); | |
2516 | } | |
2517 | ||
2518 | ||
2519 | /* Checks whether EXPR is a simple local goto. */ | |
2520 | ||
2521 | bool | |
2522 | simple_goto_p (tree expr) | |
2523 | { | |
ab8907ef RH |
2524 | return (TREE_CODE (expr) == GOTO_EXPR |
2525 | && TREE_CODE (GOTO_DESTINATION (expr)) == LABEL_DECL); | |
6de9cd9a DN |
2526 | } |
2527 | ||
2528 | ||
2529 | /* Return true if T should start a new basic block. PREV_T is the | |
2530 | statement preceding T. It is used when T is a label or a case label. | |
2531 | Labels should only start a new basic block if their previous statement | |
2532 | wasn't a label. Otherwise, sequence of labels would generate | |
2533 | unnecessary basic blocks that only contain a single label. */ | |
2534 | ||
2535 | static inline bool | |
2536 | stmt_starts_bb_p (tree t, tree prev_t) | |
2537 | { | |
6de9cd9a DN |
2538 | if (t == NULL_TREE) |
2539 | return false; | |
2540 | ||
2541 | /* LABEL_EXPRs start a new basic block only if the preceding | |
2542 | statement wasn't a label of the same type. This prevents the | |
2543 | creation of consecutive blocks that have nothing but a single | |
2544 | label. */ | |
229cc11f | 2545 | if (TREE_CODE (t) == LABEL_EXPR) |
6de9cd9a DN |
2546 | { |
2547 | /* Nonlocal and computed GOTO targets always start a new block. */ | |
229cc11f KH |
2548 | if (DECL_NONLOCAL (LABEL_EXPR_LABEL (t)) |
2549 | || FORCED_LABEL (LABEL_EXPR_LABEL (t))) | |
6de9cd9a DN |
2550 | return true; |
2551 | ||
229cc11f | 2552 | if (prev_t && TREE_CODE (prev_t) == LABEL_EXPR) |
6de9cd9a DN |
2553 | { |
2554 | if (DECL_NONLOCAL (LABEL_EXPR_LABEL (prev_t))) | |
2555 | return true; | |
2556 | ||
2557 | cfg_stats.num_merged_labels++; | |
2558 | return false; | |
2559 | } | |
2560 | else | |
2561 | return true; | |
2562 | } | |
2563 | ||
2564 | return false; | |
2565 | } | |
2566 | ||
2567 | ||
2568 | /* Return true if T should end a basic block. */ | |
2569 | ||
2570 | bool | |
2571 | stmt_ends_bb_p (tree t) | |
2572 | { | |
2573 | return is_ctrl_stmt (t) || is_ctrl_altering_stmt (t); | |
2574 | } | |
2575 | ||
2576 | ||
2577 | /* Add gotos that used to be represented implicitly in the CFG. */ | |
2578 | ||
2579 | void | |
2580 | disband_implicit_edges (void) | |
2581 | { | |
2582 | basic_block bb; | |
2583 | block_stmt_iterator last; | |
2584 | edge e; | |
628f6a4e | 2585 | edge_iterator ei; |
eb4e1c01 | 2586 | tree stmt, label; |
6de9cd9a DN |
2587 | |
2588 | FOR_EACH_BB (bb) | |
2589 | { | |
2590 | last = bsi_last (bb); | |
2591 | stmt = last_stmt (bb); | |
2592 | ||
2593 | if (stmt && TREE_CODE (stmt) == COND_EXPR) | |
2594 | { | |
2595 | /* Remove superfluous gotos from COND_EXPR branches. Moved | |
2596 | from cfg_remove_useless_stmts here since it violates the | |
2597 | invariants for tree--cfg correspondence and thus fits better | |
2598 | here where we do it anyway. */ | |
9ff3d2de JL |
2599 | e = find_edge (bb, bb->next_bb); |
2600 | if (e) | |
6de9cd9a | 2601 | { |
6de9cd9a DN |
2602 | if (e->flags & EDGE_TRUE_VALUE) |
2603 | COND_EXPR_THEN (stmt) = build_empty_stmt (); | |
2604 | else if (e->flags & EDGE_FALSE_VALUE) | |
2605 | COND_EXPR_ELSE (stmt) = build_empty_stmt (); | |
2606 | else | |
1e128c5f | 2607 | gcc_unreachable (); |
6de9cd9a DN |
2608 | e->flags |= EDGE_FALLTHRU; |
2609 | } | |
2610 | ||
2611 | continue; | |
2612 | } | |
2613 | ||
2614 | if (stmt && TREE_CODE (stmt) == RETURN_EXPR) | |
2615 | { | |
2616 | /* Remove the RETURN_EXPR if we may fall though to the exit | |
2617 | instead. */ | |
c5cbcccf ZD |
2618 | gcc_assert (single_succ_p (bb)); |
2619 | gcc_assert (single_succ (bb) == EXIT_BLOCK_PTR); | |
6de9cd9a DN |
2620 | |
2621 | if (bb->next_bb == EXIT_BLOCK_PTR | |
2622 | && !TREE_OPERAND (stmt, 0)) | |
2623 | { | |
736432ee | 2624 | bsi_remove (&last, true); |
c5cbcccf | 2625 | single_succ_edge (bb)->flags |= EDGE_FALLTHRU; |
6de9cd9a DN |
2626 | } |
2627 | continue; | |
2628 | } | |
2629 | ||
2630 | /* There can be no fallthru edge if the last statement is a control | |
2631 | one. */ | |
2632 | if (stmt && is_ctrl_stmt (stmt)) | |
2633 | continue; | |
2634 | ||
2635 | /* Find a fallthru edge and emit the goto if necessary. */ | |
628f6a4e | 2636 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
2637 | if (e->flags & EDGE_FALLTHRU) |
2638 | break; | |
2639 | ||
62b857ea | 2640 | if (!e || e->dest == bb->next_bb) |
6de9cd9a DN |
2641 | continue; |
2642 | ||
1e128c5f | 2643 | gcc_assert (e->dest != EXIT_BLOCK_PTR); |
6de9cd9a DN |
2644 | label = tree_block_label (e->dest); |
2645 | ||
62b857ea | 2646 | stmt = build1 (GOTO_EXPR, void_type_node, label); |
9506ac2b PB |
2647 | #ifdef USE_MAPPED_LOCATION |
2648 | SET_EXPR_LOCATION (stmt, e->goto_locus); | |
2649 | #else | |
62b857ea | 2650 | SET_EXPR_LOCUS (stmt, e->goto_locus); |
9506ac2b | 2651 | #endif |
62b857ea | 2652 | bsi_insert_after (&last, stmt, BSI_NEW_STMT); |
6de9cd9a DN |
2653 | e->flags &= ~EDGE_FALLTHRU; |
2654 | } | |
2655 | } | |
2656 | ||
242229bb | 2657 | /* Remove block annotations and other datastructures. */ |
6de9cd9a DN |
2658 | |
2659 | void | |
242229bb | 2660 | delete_tree_cfg_annotations (void) |
6de9cd9a | 2661 | { |
6de9cd9a | 2662 | label_to_block_map = NULL; |
6de9cd9a DN |
2663 | } |
2664 | ||
2665 | ||
2666 | /* Return the first statement in basic block BB. */ | |
2667 | ||
2668 | tree | |
2669 | first_stmt (basic_block bb) | |
2670 | { | |
2671 | block_stmt_iterator i = bsi_start (bb); | |
2672 | return !bsi_end_p (i) ? bsi_stmt (i) : NULL_TREE; | |
2673 | } | |
2674 | ||
2675 | ||
2676 | /* Return the last statement in basic block BB. */ | |
2677 | ||
2678 | tree | |
2679 | last_stmt (basic_block bb) | |
2680 | { | |
2681 | block_stmt_iterator b = bsi_last (bb); | |
2682 | return !bsi_end_p (b) ? bsi_stmt (b) : NULL_TREE; | |
2683 | } | |
2684 | ||
2685 | ||
2686 | /* Return a pointer to the last statement in block BB. */ | |
2687 | ||
2688 | tree * | |
2689 | last_stmt_ptr (basic_block bb) | |
2690 | { | |
2691 | block_stmt_iterator last = bsi_last (bb); | |
2692 | return !bsi_end_p (last) ? bsi_stmt_ptr (last) : NULL; | |
2693 | } | |
2694 | ||
2695 | ||
2696 | /* Return the last statement of an otherwise empty block. Return NULL | |
2697 | if the block is totally empty, or if it contains more than one | |
2698 | statement. */ | |
2699 | ||
2700 | tree | |
2701 | last_and_only_stmt (basic_block bb) | |
2702 | { | |
2703 | block_stmt_iterator i = bsi_last (bb); | |
2704 | tree last, prev; | |
2705 | ||
2706 | if (bsi_end_p (i)) | |
2707 | return NULL_TREE; | |
2708 | ||
2709 | last = bsi_stmt (i); | |
2710 | bsi_prev (&i); | |
2711 | if (bsi_end_p (i)) | |
2712 | return last; | |
2713 | ||
2714 | /* Empty statements should no longer appear in the instruction stream. | |
2715 | Everything that might have appeared before should be deleted by | |
2716 | remove_useless_stmts, and the optimizers should just bsi_remove | |
2717 | instead of smashing with build_empty_stmt. | |
2718 | ||
2719 | Thus the only thing that should appear here in a block containing | |
2720 | one executable statement is a label. */ | |
2721 | prev = bsi_stmt (i); | |
2722 | if (TREE_CODE (prev) == LABEL_EXPR) | |
2723 | return last; | |
2724 | else | |
2725 | return NULL_TREE; | |
2726 | } | |
2727 | ||
2728 | ||
2729 | /* Mark BB as the basic block holding statement T. */ | |
2730 | ||
2731 | void | |
2732 | set_bb_for_stmt (tree t, basic_block bb) | |
2733 | { | |
30d396e3 ZD |
2734 | if (TREE_CODE (t) == PHI_NODE) |
2735 | PHI_BB (t) = bb; | |
2736 | else if (TREE_CODE (t) == STATEMENT_LIST) | |
6de9cd9a DN |
2737 | { |
2738 | tree_stmt_iterator i; | |
2739 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
2740 | set_bb_for_stmt (tsi_stmt (i), bb); | |
2741 | } | |
2742 | else | |
2743 | { | |
2744 | stmt_ann_t ann = get_stmt_ann (t); | |
2745 | ann->bb = bb; | |
2746 | ||
50674e96 DN |
2747 | /* If the statement is a label, add the label to block-to-labels map |
2748 | so that we can speed up edge creation for GOTO_EXPRs. */ | |
2749 | if (TREE_CODE (t) == LABEL_EXPR) | |
6de9cd9a DN |
2750 | { |
2751 | int uid; | |
2752 | ||
2753 | t = LABEL_EXPR_LABEL (t); | |
2754 | uid = LABEL_DECL_UID (t); | |
2755 | if (uid == -1) | |
2756 | { | |
e597f337 | 2757 | unsigned old_len = VEC_length (basic_block, label_to_block_map); |
6de9cd9a | 2758 | LABEL_DECL_UID (t) = uid = cfun->last_label_uid++; |
e597f337 KH |
2759 | if (old_len <= (unsigned) uid) |
2760 | { | |
2761 | basic_block *addr; | |
2762 | unsigned new_len = 3 * uid / 2; | |
2763 | ||
2764 | VEC_safe_grow (basic_block, gc, label_to_block_map, | |
2765 | new_len); | |
2766 | addr = VEC_address (basic_block, label_to_block_map); | |
2767 | memset (&addr[old_len], | |
2768 | 0, sizeof (basic_block) * (new_len - old_len)); | |
2769 | } | |
6de9cd9a DN |
2770 | } |
2771 | else | |
1e128c5f GB |
2772 | /* We're moving an existing label. Make sure that we've |
2773 | removed it from the old block. */ | |
e597f337 KH |
2774 | gcc_assert (!bb |
2775 | || !VEC_index (basic_block, label_to_block_map, uid)); | |
2776 | VEC_replace (basic_block, label_to_block_map, uid, bb); | |
6de9cd9a DN |
2777 | } |
2778 | } | |
2779 | } | |
2780 | ||
8b11a64c ZD |
2781 | /* Finds iterator for STMT. */ |
2782 | ||
2783 | extern block_stmt_iterator | |
1a1804c2 | 2784 | bsi_for_stmt (tree stmt) |
8b11a64c ZD |
2785 | { |
2786 | block_stmt_iterator bsi; | |
2787 | ||
2788 | for (bsi = bsi_start (bb_for_stmt (stmt)); !bsi_end_p (bsi); bsi_next (&bsi)) | |
2789 | if (bsi_stmt (bsi) == stmt) | |
2790 | return bsi; | |
2791 | ||
1e128c5f | 2792 | gcc_unreachable (); |
8b11a64c | 2793 | } |
6de9cd9a | 2794 | |
f430bae8 AM |
2795 | /* Mark statement T as modified, and update it. */ |
2796 | static inline void | |
2797 | update_modified_stmts (tree t) | |
2798 | { | |
2799 | if (TREE_CODE (t) == STATEMENT_LIST) | |
2800 | { | |
2801 | tree_stmt_iterator i; | |
2802 | tree stmt; | |
2803 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
2804 | { | |
2805 | stmt = tsi_stmt (i); | |
2806 | update_stmt_if_modified (stmt); | |
2807 | } | |
2808 | } | |
2809 | else | |
2810 | update_stmt_if_modified (t); | |
2811 | } | |
2812 | ||
6de9cd9a DN |
2813 | /* Insert statement (or statement list) T before the statement |
2814 | pointed-to by iterator I. M specifies how to update iterator I | |
2815 | after insertion (see enum bsi_iterator_update). */ | |
2816 | ||
2817 | void | |
2818 | bsi_insert_before (block_stmt_iterator *i, tree t, enum bsi_iterator_update m) | |
2819 | { | |
2820 | set_bb_for_stmt (t, i->bb); | |
f430bae8 | 2821 | update_modified_stmts (t); |
6de9cd9a DN |
2822 | tsi_link_before (&i->tsi, t, m); |
2823 | } | |
2824 | ||
2825 | ||
2826 | /* Insert statement (or statement list) T after the statement | |
2827 | pointed-to by iterator I. M specifies how to update iterator I | |
2828 | after insertion (see enum bsi_iterator_update). */ | |
2829 | ||
2830 | void | |
2831 | bsi_insert_after (block_stmt_iterator *i, tree t, enum bsi_iterator_update m) | |
2832 | { | |
2833 | set_bb_for_stmt (t, i->bb); | |
f430bae8 | 2834 | update_modified_stmts (t); |
6de9cd9a DN |
2835 | tsi_link_after (&i->tsi, t, m); |
2836 | } | |
2837 | ||
2838 | ||
2839 | /* Remove the statement pointed to by iterator I. The iterator is updated | |
736432ee JL |
2840 | to the next statement. |
2841 | ||
2842 | When REMOVE_EH_INFO is true we remove the statement pointed to by | |
2843 | iterator I from the EH tables. Otherwise we do not modify the EH | |
2844 | tables. | |
2845 | ||
2846 | Generally, REMOVE_EH_INFO should be true when the statement is going to | |
2847 | be removed from the IL and not reinserted elsewhere. */ | |
6de9cd9a DN |
2848 | |
2849 | void | |
736432ee | 2850 | bsi_remove (block_stmt_iterator *i, bool remove_eh_info) |
6de9cd9a DN |
2851 | { |
2852 | tree t = bsi_stmt (*i); | |
2853 | set_bb_for_stmt (t, NULL); | |
f430bae8 | 2854 | delink_stmt_imm_use (t); |
6de9cd9a | 2855 | tsi_delink (&i->tsi); |
f430bae8 | 2856 | mark_stmt_modified (t); |
736432ee JL |
2857 | if (remove_eh_info) |
2858 | remove_stmt_from_eh_region (t); | |
6de9cd9a DN |
2859 | } |
2860 | ||
2861 | ||
2862 | /* Move the statement at FROM so it comes right after the statement at TO. */ | |
2863 | ||
2864 | void | |
2865 | bsi_move_after (block_stmt_iterator *from, block_stmt_iterator *to) | |
2866 | { | |
2867 | tree stmt = bsi_stmt (*from); | |
736432ee | 2868 | bsi_remove (from, false); |
6de9cd9a DN |
2869 | bsi_insert_after (to, stmt, BSI_SAME_STMT); |
2870 | } | |
2871 | ||
2872 | ||
2873 | /* Move the statement at FROM so it comes right before the statement at TO. */ | |
2874 | ||
2875 | void | |
2876 | bsi_move_before (block_stmt_iterator *from, block_stmt_iterator *to) | |
2877 | { | |
2878 | tree stmt = bsi_stmt (*from); | |
736432ee | 2879 | bsi_remove (from, false); |
6de9cd9a DN |
2880 | bsi_insert_before (to, stmt, BSI_SAME_STMT); |
2881 | } | |
2882 | ||
2883 | ||
2884 | /* Move the statement at FROM to the end of basic block BB. */ | |
2885 | ||
2886 | void | |
2887 | bsi_move_to_bb_end (block_stmt_iterator *from, basic_block bb) | |
2888 | { | |
2889 | block_stmt_iterator last = bsi_last (bb); | |
2890 | ||
2891 | /* Have to check bsi_end_p because it could be an empty block. */ | |
2892 | if (!bsi_end_p (last) && is_ctrl_stmt (bsi_stmt (last))) | |
2893 | bsi_move_before (from, &last); | |
2894 | else | |
2895 | bsi_move_after (from, &last); | |
2896 | } | |
2897 | ||
2898 | ||
2899 | /* Replace the contents of the statement pointed to by iterator BSI | |
736432ee JL |
2900 | with STMT. If UPDATE_EH_INFO is true, the exception handling |
2901 | information of the original statement is moved to the new statement. */ | |
2902 | ||
6de9cd9a DN |
2903 | |
2904 | void | |
736432ee | 2905 | bsi_replace (const block_stmt_iterator *bsi, tree stmt, bool update_eh_info) |
6de9cd9a DN |
2906 | { |
2907 | int eh_region; | |
2908 | tree orig_stmt = bsi_stmt (*bsi); | |
2909 | ||
2910 | SET_EXPR_LOCUS (stmt, EXPR_LOCUS (orig_stmt)); | |
2911 | set_bb_for_stmt (stmt, bsi->bb); | |
2912 | ||
2913 | /* Preserve EH region information from the original statement, if | |
2914 | requested by the caller. */ | |
736432ee | 2915 | if (update_eh_info) |
6de9cd9a DN |
2916 | { |
2917 | eh_region = lookup_stmt_eh_region (orig_stmt); | |
2918 | if (eh_region >= 0) | |
59bb84ef | 2919 | { |
736432ee | 2920 | remove_stmt_from_eh_region (orig_stmt); |
59bb84ef JL |
2921 | add_stmt_to_eh_region (stmt, eh_region); |
2922 | } | |
6de9cd9a DN |
2923 | } |
2924 | ||
b1ca239f | 2925 | delink_stmt_imm_use (orig_stmt); |
6de9cd9a | 2926 | *bsi_stmt_ptr (*bsi) = stmt; |
f430bae8 AM |
2927 | mark_stmt_modified (stmt); |
2928 | update_modified_stmts (stmt); | |
6de9cd9a DN |
2929 | } |
2930 | ||
2931 | ||
2932 | /* Insert the statement pointed-to by BSI into edge E. Every attempt | |
2933 | is made to place the statement in an existing basic block, but | |
2934 | sometimes that isn't possible. When it isn't possible, the edge is | |
2935 | split and the statement is added to the new block. | |
2936 | ||
2937 | In all cases, the returned *BSI points to the correct location. The | |
2938 | return value is true if insertion should be done after the location, | |
82b85a85 ZD |
2939 | or false if it should be done before the location. If new basic block |
2940 | has to be created, it is stored in *NEW_BB. */ | |
6de9cd9a DN |
2941 | |
2942 | static bool | |
82b85a85 ZD |
2943 | tree_find_edge_insert_loc (edge e, block_stmt_iterator *bsi, |
2944 | basic_block *new_bb) | |
6de9cd9a DN |
2945 | { |
2946 | basic_block dest, src; | |
2947 | tree tmp; | |
2948 | ||
2949 | dest = e->dest; | |
2950 | restart: | |
2951 | ||
2952 | /* If the destination has one predecessor which has no PHI nodes, | |
2953 | insert there. Except for the exit block. | |
2954 | ||
2955 | The requirement for no PHI nodes could be relaxed. Basically we | |
2956 | would have to examine the PHIs to prove that none of them used | |
e28d0cfb | 2957 | the value set by the statement we want to insert on E. That |
6de9cd9a | 2958 | hardly seems worth the effort. */ |
c5cbcccf | 2959 | if (single_pred_p (dest) |
6de9cd9a DN |
2960 | && ! phi_nodes (dest) |
2961 | && dest != EXIT_BLOCK_PTR) | |
2962 | { | |
2963 | *bsi = bsi_start (dest); | |
2964 | if (bsi_end_p (*bsi)) | |
2965 | return true; | |
2966 | ||
2967 | /* Make sure we insert after any leading labels. */ | |
2968 | tmp = bsi_stmt (*bsi); | |
2969 | while (TREE_CODE (tmp) == LABEL_EXPR) | |
2970 | { | |
2971 | bsi_next (bsi); | |
2972 | if (bsi_end_p (*bsi)) | |
2973 | break; | |
2974 | tmp = bsi_stmt (*bsi); | |
2975 | } | |
2976 | ||
2977 | if (bsi_end_p (*bsi)) | |
2978 | { | |
2979 | *bsi = bsi_last (dest); | |
2980 | return true; | |
2981 | } | |
2982 | else | |
2983 | return false; | |
2984 | } | |
2985 | ||
2986 | /* If the source has one successor, the edge is not abnormal and | |
2987 | the last statement does not end a basic block, insert there. | |
2988 | Except for the entry block. */ | |
2989 | src = e->src; | |
2990 | if ((e->flags & EDGE_ABNORMAL) == 0 | |
c5cbcccf | 2991 | && single_succ_p (src) |
6de9cd9a DN |
2992 | && src != ENTRY_BLOCK_PTR) |
2993 | { | |
2994 | *bsi = bsi_last (src); | |
2995 | if (bsi_end_p (*bsi)) | |
2996 | return true; | |
2997 | ||
2998 | tmp = bsi_stmt (*bsi); | |
2999 | if (!stmt_ends_bb_p (tmp)) | |
3000 | return true; | |
ce068299 JH |
3001 | |
3002 | /* Insert code just before returning the value. We may need to decompose | |
3003 | the return in the case it contains non-trivial operand. */ | |
3004 | if (TREE_CODE (tmp) == RETURN_EXPR) | |
3005 | { | |
3006 | tree op = TREE_OPERAND (tmp, 0); | |
7802250d | 3007 | if (op && !is_gimple_val (op)) |
ce068299 | 3008 | { |
1e128c5f | 3009 | gcc_assert (TREE_CODE (op) == MODIFY_EXPR); |
ce068299 JH |
3010 | bsi_insert_before (bsi, op, BSI_NEW_STMT); |
3011 | TREE_OPERAND (tmp, 0) = TREE_OPERAND (op, 0); | |
3012 | } | |
3013 | bsi_prev (bsi); | |
3014 | return true; | |
3015 | } | |
6de9cd9a DN |
3016 | } |
3017 | ||
3018 | /* Otherwise, create a new basic block, and split this edge. */ | |
3019 | dest = split_edge (e); | |
82b85a85 ZD |
3020 | if (new_bb) |
3021 | *new_bb = dest; | |
c5cbcccf | 3022 | e = single_pred_edge (dest); |
6de9cd9a DN |
3023 | goto restart; |
3024 | } | |
3025 | ||
3026 | ||
3027 | /* This routine will commit all pending edge insertions, creating any new | |
8e731e4e | 3028 | basic blocks which are necessary. */ |
6de9cd9a DN |
3029 | |
3030 | void | |
8e731e4e | 3031 | bsi_commit_edge_inserts (void) |
6de9cd9a DN |
3032 | { |
3033 | basic_block bb; | |
3034 | edge e; | |
628f6a4e | 3035 | edge_iterator ei; |
6de9cd9a | 3036 | |
c5cbcccf | 3037 | bsi_commit_one_edge_insert (single_succ_edge (ENTRY_BLOCK_PTR), NULL); |
6de9cd9a DN |
3038 | |
3039 | FOR_EACH_BB (bb) | |
628f6a4e | 3040 | FOR_EACH_EDGE (e, ei, bb->succs) |
edfaf675 | 3041 | bsi_commit_one_edge_insert (e, NULL); |
6de9cd9a DN |
3042 | } |
3043 | ||
3044 | ||
edfaf675 AM |
3045 | /* Commit insertions pending at edge E. If a new block is created, set NEW_BB |
3046 | to this block, otherwise set it to NULL. */ | |
6de9cd9a | 3047 | |
edfaf675 AM |
3048 | void |
3049 | bsi_commit_one_edge_insert (edge e, basic_block *new_bb) | |
6de9cd9a | 3050 | { |
edfaf675 AM |
3051 | if (new_bb) |
3052 | *new_bb = NULL; | |
6de9cd9a DN |
3053 | if (PENDING_STMT (e)) |
3054 | { | |
3055 | block_stmt_iterator bsi; | |
3056 | tree stmt = PENDING_STMT (e); | |
3057 | ||
3058 | PENDING_STMT (e) = NULL_TREE; | |
3059 | ||
edfaf675 | 3060 | if (tree_find_edge_insert_loc (e, &bsi, new_bb)) |
6de9cd9a DN |
3061 | bsi_insert_after (&bsi, stmt, BSI_NEW_STMT); |
3062 | else | |
3063 | bsi_insert_before (&bsi, stmt, BSI_NEW_STMT); | |
3064 | } | |
3065 | } | |
3066 | ||
3067 | ||
3068 | /* Add STMT to the pending list of edge E. No actual insertion is | |
3069 | made until a call to bsi_commit_edge_inserts () is made. */ | |
3070 | ||
3071 | void | |
3072 | bsi_insert_on_edge (edge e, tree stmt) | |
3073 | { | |
3074 | append_to_statement_list (stmt, &PENDING_STMT (e)); | |
3075 | } | |
3076 | ||
adb35797 KH |
3077 | /* Similar to bsi_insert_on_edge+bsi_commit_edge_inserts. If a new |
3078 | block has to be created, it is returned. */ | |
82b85a85 ZD |
3079 | |
3080 | basic_block | |
3081 | bsi_insert_on_edge_immediate (edge e, tree stmt) | |
3082 | { | |
3083 | block_stmt_iterator bsi; | |
3084 | basic_block new_bb = NULL; | |
3085 | ||
1e128c5f | 3086 | gcc_assert (!PENDING_STMT (e)); |
82b85a85 ZD |
3087 | |
3088 | if (tree_find_edge_insert_loc (e, &bsi, &new_bb)) | |
3089 | bsi_insert_after (&bsi, stmt, BSI_NEW_STMT); | |
3090 | else | |
3091 | bsi_insert_before (&bsi, stmt, BSI_NEW_STMT); | |
3092 | ||
3093 | return new_bb; | |
3094 | } | |
6de9cd9a | 3095 | |
6de9cd9a DN |
3096 | /*--------------------------------------------------------------------------- |
3097 | Tree specific functions for CFG manipulation | |
3098 | ---------------------------------------------------------------------------*/ | |
3099 | ||
4f7db7f7 KH |
3100 | /* Reinstall those PHI arguments queued in OLD_EDGE to NEW_EDGE. */ |
3101 | ||
3102 | static void | |
3103 | reinstall_phi_args (edge new_edge, edge old_edge) | |
3104 | { | |
3105 | tree var, phi; | |
3106 | ||
3107 | if (!PENDING_STMT (old_edge)) | |
3108 | return; | |
3109 | ||
3110 | for (var = PENDING_STMT (old_edge), phi = phi_nodes (new_edge->dest); | |
3111 | var && phi; | |
3112 | var = TREE_CHAIN (var), phi = PHI_CHAIN (phi)) | |
3113 | { | |
3114 | tree result = TREE_PURPOSE (var); | |
3115 | tree arg = TREE_VALUE (var); | |
3116 | ||
3117 | gcc_assert (result == PHI_RESULT (phi)); | |
3118 | ||
d2e398df | 3119 | add_phi_arg (phi, arg, new_edge); |
4f7db7f7 KH |
3120 | } |
3121 | ||
3122 | PENDING_STMT (old_edge) = NULL; | |
3123 | } | |
3124 | ||
b9a66240 ZD |
3125 | /* Returns the basic block after that the new basic block created |
3126 | by splitting edge EDGE_IN should be placed. Tries to keep the new block | |
3127 | near its "logical" location. This is of most help to humans looking | |
3128 | at debugging dumps. */ | |
3129 | ||
3130 | static basic_block | |
3131 | split_edge_bb_loc (edge edge_in) | |
3132 | { | |
3133 | basic_block dest = edge_in->dest; | |
3134 | ||
3135 | if (dest->prev_bb && find_edge (dest->prev_bb, dest)) | |
3136 | return edge_in->src; | |
3137 | else | |
3138 | return dest->prev_bb; | |
3139 | } | |
3140 | ||
6de9cd9a DN |
3141 | /* Split a (typically critical) edge EDGE_IN. Return the new block. |
3142 | Abort on abnormal edges. */ | |
3143 | ||
3144 | static basic_block | |
3145 | tree_split_edge (edge edge_in) | |
3146 | { | |
3147 | basic_block new_bb, after_bb, dest, src; | |
3148 | edge new_edge, e; | |
6de9cd9a DN |
3149 | |
3150 | /* Abnormal edges cannot be split. */ | |
1e128c5f | 3151 | gcc_assert (!(edge_in->flags & EDGE_ABNORMAL)); |
6de9cd9a DN |
3152 | |
3153 | src = edge_in->src; | |
3154 | dest = edge_in->dest; | |
3155 | ||
b9a66240 | 3156 | after_bb = split_edge_bb_loc (edge_in); |
6de9cd9a DN |
3157 | |
3158 | new_bb = create_empty_bb (after_bb); | |
b829f3fa JH |
3159 | new_bb->frequency = EDGE_FREQUENCY (edge_in); |
3160 | new_bb->count = edge_in->count; | |
6de9cd9a | 3161 | new_edge = make_edge (new_bb, dest, EDGE_FALLTHRU); |
b829f3fa JH |
3162 | new_edge->probability = REG_BR_PROB_BASE; |
3163 | new_edge->count = edge_in->count; | |
6de9cd9a | 3164 | |
1e128c5f GB |
3165 | e = redirect_edge_and_branch (edge_in, new_bb); |
3166 | gcc_assert (e); | |
4f7db7f7 | 3167 | reinstall_phi_args (new_edge, e); |
6de9cd9a DN |
3168 | |
3169 | return new_bb; | |
3170 | } | |
3171 | ||
3172 | ||
3173 | /* Return true when BB has label LABEL in it. */ | |
3174 | ||
3175 | static bool | |
3176 | has_label_p (basic_block bb, tree label) | |
3177 | { | |
3178 | block_stmt_iterator bsi; | |
3179 | ||
3180 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
3181 | { | |
3182 | tree stmt = bsi_stmt (bsi); | |
3183 | ||
3184 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
3185 | return false; | |
3186 | if (LABEL_EXPR_LABEL (stmt) == label) | |
3187 | return true; | |
3188 | } | |
3189 | return false; | |
3190 | } | |
3191 | ||
3192 | ||
3193 | /* Callback for walk_tree, check that all elements with address taken are | |
7a442a1d SB |
3194 | properly noticed as such. The DATA is an int* that is 1 if TP was seen |
3195 | inside a PHI node. */ | |
6de9cd9a DN |
3196 | |
3197 | static tree | |
2fbe90f2 | 3198 | verify_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) |
6de9cd9a DN |
3199 | { |
3200 | tree t = *tp, x; | |
7a442a1d | 3201 | bool in_phi = (data != NULL); |
6de9cd9a DN |
3202 | |
3203 | if (TYPE_P (t)) | |
3204 | *walk_subtrees = 0; | |
2fbe90f2 | 3205 | |
e8ca4159 | 3206 | /* Check operand N for being valid GIMPLE and give error MSG if not. */ |
2fbe90f2 | 3207 | #define CHECK_OP(N, MSG) \ |
e8ca4159 | 3208 | do { if (!is_gimple_val (TREE_OPERAND (t, N))) \ |
2fbe90f2 | 3209 | { error (MSG); return TREE_OPERAND (t, N); }} while (0) |
6de9cd9a DN |
3210 | |
3211 | switch (TREE_CODE (t)) | |
3212 | { | |
3213 | case SSA_NAME: | |
3214 | if (SSA_NAME_IN_FREE_LIST (t)) | |
3215 | { | |
3216 | error ("SSA name in freelist but still referenced"); | |
3217 | return *tp; | |
3218 | } | |
3219 | break; | |
3220 | ||
0bca51f0 DN |
3221 | case ASSERT_EXPR: |
3222 | x = fold (ASSERT_EXPR_COND (t)); | |
3223 | if (x == boolean_false_node) | |
3224 | { | |
3225 | error ("ASSERT_EXPR with an always-false condition"); | |
3226 | return *tp; | |
3227 | } | |
3228 | break; | |
3229 | ||
6de9cd9a DN |
3230 | case MODIFY_EXPR: |
3231 | x = TREE_OPERAND (t, 0); | |
3232 | if (TREE_CODE (x) == BIT_FIELD_REF | |
3233 | && is_gimple_reg (TREE_OPERAND (x, 0))) | |
3234 | { | |
3235 | error ("GIMPLE register modified with BIT_FIELD_REF"); | |
2fbe90f2 | 3236 | return t; |
6de9cd9a DN |
3237 | } |
3238 | break; | |
3239 | ||
3240 | case ADDR_EXPR: | |
81fc3052 DB |
3241 | { |
3242 | bool old_invariant; | |
3243 | bool old_constant; | |
3244 | bool old_side_effects; | |
3245 | bool new_invariant; | |
3246 | bool new_constant; | |
3247 | bool new_side_effects; | |
3248 | ||
3249 | /* ??? tree-ssa-alias.c may have overlooked dead PHI nodes, missing | |
3250 | dead PHIs that take the address of something. But if the PHI | |
3251 | result is dead, the fact that it takes the address of anything | |
3252 | is irrelevant. Because we can not tell from here if a PHI result | |
3253 | is dead, we just skip this check for PHIs altogether. This means | |
3254 | we may be missing "valid" checks, but what can you do? | |
3255 | This was PR19217. */ | |
3256 | if (in_phi) | |
3257 | break; | |
7a442a1d | 3258 | |
81fc3052 DB |
3259 | old_invariant = TREE_INVARIANT (t); |
3260 | old_constant = TREE_CONSTANT (t); | |
3261 | old_side_effects = TREE_SIDE_EFFECTS (t); | |
3262 | ||
127203ac | 3263 | recompute_tree_invariant_for_addr_expr (t); |
81fc3052 DB |
3264 | new_invariant = TREE_INVARIANT (t); |
3265 | new_side_effects = TREE_SIDE_EFFECTS (t); | |
3266 | new_constant = TREE_CONSTANT (t); | |
3267 | ||
3268 | if (old_invariant != new_invariant) | |
3269 | { | |
3270 | error ("invariant not recomputed when ADDR_EXPR changed"); | |
3271 | return t; | |
3272 | } | |
3273 | ||
3274 | if (old_constant != new_constant) | |
3275 | { | |
3276 | error ("constant not recomputed when ADDR_EXPR changed"); | |
3277 | return t; | |
3278 | } | |
3279 | if (old_side_effects != new_side_effects) | |
3280 | { | |
3281 | error ("side effects not recomputed when ADDR_EXPR changed"); | |
3282 | return t; | |
3283 | } | |
3284 | ||
3285 | /* Skip any references (they will be checked when we recurse down the | |
3286 | tree) and ensure that any variable used as a prefix is marked | |
3287 | addressable. */ | |
3288 | for (x = TREE_OPERAND (t, 0); | |
3289 | handled_component_p (x); | |
3290 | x = TREE_OPERAND (x, 0)) | |
3291 | ; | |
3292 | ||
3293 | if (TREE_CODE (x) != VAR_DECL && TREE_CODE (x) != PARM_DECL) | |
3294 | return NULL; | |
3295 | if (!TREE_ADDRESSABLE (x)) | |
3296 | { | |
3297 | error ("address taken, but ADDRESSABLE bit not set"); | |
3298 | return x; | |
3299 | } | |
3300 | break; | |
3301 | } | |
6de9cd9a DN |
3302 | |
3303 | case COND_EXPR: | |
a6234684 | 3304 | x = COND_EXPR_COND (t); |
6de9cd9a DN |
3305 | if (TREE_CODE (TREE_TYPE (x)) != BOOLEAN_TYPE) |
3306 | { | |
3307 | error ("non-boolean used in condition"); | |
3308 | return x; | |
3309 | } | |
9c691961 AP |
3310 | if (!is_gimple_condexpr (x)) |
3311 | { | |
ab532386 | 3312 | error ("invalid conditional operand"); |
9c691961 AP |
3313 | return x; |
3314 | } | |
6de9cd9a DN |
3315 | break; |
3316 | ||
3317 | case NOP_EXPR: | |
3318 | case CONVERT_EXPR: | |
3319 | case FIX_TRUNC_EXPR: | |
3320 | case FIX_CEIL_EXPR: | |
3321 | case FIX_FLOOR_EXPR: | |
3322 | case FIX_ROUND_EXPR: | |
3323 | case FLOAT_EXPR: | |
3324 | case NEGATE_EXPR: | |
3325 | case ABS_EXPR: | |
3326 | case BIT_NOT_EXPR: | |
3327 | case NON_LVALUE_EXPR: | |
3328 | case TRUTH_NOT_EXPR: | |
ab532386 | 3329 | CHECK_OP (0, "invalid operand to unary operator"); |
6de9cd9a DN |
3330 | break; |
3331 | ||
3332 | case REALPART_EXPR: | |
3333 | case IMAGPART_EXPR: | |
2fbe90f2 RK |
3334 | case COMPONENT_REF: |
3335 | case ARRAY_REF: | |
3336 | case ARRAY_RANGE_REF: | |
3337 | case BIT_FIELD_REF: | |
3338 | case VIEW_CONVERT_EXPR: | |
3339 | /* We have a nest of references. Verify that each of the operands | |
3340 | that determine where to reference is either a constant or a variable, | |
3341 | verify that the base is valid, and then show we've already checked | |
3342 | the subtrees. */ | |
afe84921 | 3343 | while (handled_component_p (t)) |
2fbe90f2 RK |
3344 | { |
3345 | if (TREE_CODE (t) == COMPONENT_REF && TREE_OPERAND (t, 2)) | |
ab532386 | 3346 | CHECK_OP (2, "invalid COMPONENT_REF offset operator"); |
2fbe90f2 RK |
3347 | else if (TREE_CODE (t) == ARRAY_REF |
3348 | || TREE_CODE (t) == ARRAY_RANGE_REF) | |
3349 | { | |
ab532386 | 3350 | CHECK_OP (1, "invalid array index"); |
2fbe90f2 | 3351 | if (TREE_OPERAND (t, 2)) |
ab532386 | 3352 | CHECK_OP (2, "invalid array lower bound"); |
2fbe90f2 | 3353 | if (TREE_OPERAND (t, 3)) |
ab532386 | 3354 | CHECK_OP (3, "invalid array stride"); |
2fbe90f2 RK |
3355 | } |
3356 | else if (TREE_CODE (t) == BIT_FIELD_REF) | |
3357 | { | |
ab532386 JM |
3358 | CHECK_OP (1, "invalid operand to BIT_FIELD_REF"); |
3359 | CHECK_OP (2, "invalid operand to BIT_FIELD_REF"); | |
2fbe90f2 RK |
3360 | } |
3361 | ||
3362 | t = TREE_OPERAND (t, 0); | |
3363 | } | |
3364 | ||
6615c446 | 3365 | if (!CONSTANT_CLASS_P (t) && !is_gimple_lvalue (t)) |
2fbe90f2 | 3366 | { |
ab532386 | 3367 | error ("invalid reference prefix"); |
2fbe90f2 RK |
3368 | return t; |
3369 | } | |
3370 | *walk_subtrees = 0; | |
6de9cd9a DN |
3371 | break; |
3372 | ||
3373 | case LT_EXPR: | |
3374 | case LE_EXPR: | |
3375 | case GT_EXPR: | |
3376 | case GE_EXPR: | |
3377 | case EQ_EXPR: | |
3378 | case NE_EXPR: | |
3379 | case UNORDERED_EXPR: | |
3380 | case ORDERED_EXPR: | |
3381 | case UNLT_EXPR: | |
3382 | case UNLE_EXPR: | |
3383 | case UNGT_EXPR: | |
3384 | case UNGE_EXPR: | |
3385 | case UNEQ_EXPR: | |
d1a7edaf | 3386 | case LTGT_EXPR: |
6de9cd9a DN |
3387 | case PLUS_EXPR: |
3388 | case MINUS_EXPR: | |
3389 | case MULT_EXPR: | |
3390 | case TRUNC_DIV_EXPR: | |
3391 | case CEIL_DIV_EXPR: | |
3392 | case FLOOR_DIV_EXPR: | |
3393 | case ROUND_DIV_EXPR: | |
3394 | case TRUNC_MOD_EXPR: | |
3395 | case CEIL_MOD_EXPR: | |
3396 | case FLOOR_MOD_EXPR: | |
3397 | case ROUND_MOD_EXPR: | |
3398 | case RDIV_EXPR: | |
3399 | case EXACT_DIV_EXPR: | |
3400 | case MIN_EXPR: | |
3401 | case MAX_EXPR: | |
3402 | case LSHIFT_EXPR: | |
3403 | case RSHIFT_EXPR: | |
3404 | case LROTATE_EXPR: | |
3405 | case RROTATE_EXPR: | |
3406 | case BIT_IOR_EXPR: | |
3407 | case BIT_XOR_EXPR: | |
3408 | case BIT_AND_EXPR: | |
ab532386 JM |
3409 | CHECK_OP (0, "invalid operand to binary operator"); |
3410 | CHECK_OP (1, "invalid operand to binary operator"); | |
6de9cd9a DN |
3411 | break; |
3412 | ||
3413 | default: | |
3414 | break; | |
3415 | } | |
3416 | return NULL; | |
2fbe90f2 RK |
3417 | |
3418 | #undef CHECK_OP | |
6de9cd9a DN |
3419 | } |
3420 | ||
3421 | ||
3422 | /* Verify STMT, return true if STMT is not in GIMPLE form. | |
3423 | TODO: Implement type checking. */ | |
3424 | ||
3425 | static bool | |
1eaba2f2 | 3426 | verify_stmt (tree stmt, bool last_in_block) |
6de9cd9a DN |
3427 | { |
3428 | tree addr; | |
3429 | ||
50674e96 DN |
3430 | if (OMP_DIRECTIVE_P (stmt)) |
3431 | { | |
3432 | /* OpenMP directives are validated by the FE and never operated | |
3433 | on by the optimizers. Furthermore, OMP_FOR may contain | |
3434 | non-gimple expressions when the main index variable has had | |
3435 | its address taken. This does not affect the loop itself | |
3436 | because the header of an OMP_FOR is merely used to determine | |
3437 | how to setup the parallel iteration. */ | |
3438 | return false; | |
3439 | } | |
3440 | ||
6de9cd9a DN |
3441 | if (!is_gimple_stmt (stmt)) |
3442 | { | |
ab532386 | 3443 | error ("is not a valid GIMPLE statement"); |
1eaba2f2 | 3444 | goto fail; |
6de9cd9a DN |
3445 | } |
3446 | ||
3447 | addr = walk_tree (&stmt, verify_expr, NULL, NULL); | |
3448 | if (addr) | |
3449 | { | |
3450 | debug_generic_stmt (addr); | |
3451 | return true; | |
3452 | } | |
3453 | ||
1eaba2f2 RH |
3454 | /* If the statement is marked as part of an EH region, then it is |
3455 | expected that the statement could throw. Verify that when we | |
3456 | have optimizations that simplify statements such that we prove | |
3457 | that they cannot throw, that we update other data structures | |
3458 | to match. */ | |
3459 | if (lookup_stmt_eh_region (stmt) >= 0) | |
3460 | { | |
3461 | if (!tree_could_throw_p (stmt)) | |
3462 | { | |
ab532386 | 3463 | error ("statement marked for throw, but doesn%'t"); |
1eaba2f2 RH |
3464 | goto fail; |
3465 | } | |
3466 | if (!last_in_block && tree_can_throw_internal (stmt)) | |
3467 | { | |
ab532386 | 3468 | error ("statement marked for throw in middle of block"); |
1eaba2f2 RH |
3469 | goto fail; |
3470 | } | |
3471 | } | |
3472 | ||
6de9cd9a | 3473 | return false; |
1eaba2f2 RH |
3474 | |
3475 | fail: | |
3476 | debug_generic_stmt (stmt); | |
3477 | return true; | |
6de9cd9a DN |
3478 | } |
3479 | ||
3480 | ||
3481 | /* Return true when the T can be shared. */ | |
3482 | ||
3483 | static bool | |
3484 | tree_node_can_be_shared (tree t) | |
3485 | { | |
6615c446 | 3486 | if (IS_TYPE_OR_DECL_P (t) |
6de9cd9a | 3487 | || is_gimple_min_invariant (t) |
5e23162d | 3488 | || TREE_CODE (t) == SSA_NAME |
953ff289 DN |
3489 | || t == error_mark_node |
3490 | || TREE_CODE (t) == IDENTIFIER_NODE) | |
6de9cd9a DN |
3491 | return true; |
3492 | ||
92b6dff3 JL |
3493 | if (TREE_CODE (t) == CASE_LABEL_EXPR) |
3494 | return true; | |
3495 | ||
44de5aeb | 3496 | while (((TREE_CODE (t) == ARRAY_REF || TREE_CODE (t) == ARRAY_RANGE_REF) |
953ff289 DN |
3497 | && is_gimple_min_invariant (TREE_OPERAND (t, 1))) |
3498 | || TREE_CODE (t) == COMPONENT_REF | |
3499 | || TREE_CODE (t) == REALPART_EXPR | |
3500 | || TREE_CODE (t) == IMAGPART_EXPR) | |
6de9cd9a DN |
3501 | t = TREE_OPERAND (t, 0); |
3502 | ||
3503 | if (DECL_P (t)) | |
3504 | return true; | |
3505 | ||
3506 | return false; | |
3507 | } | |
3508 | ||
3509 | ||
3510 | /* Called via walk_trees. Verify tree sharing. */ | |
3511 | ||
3512 | static tree | |
3513 | verify_node_sharing (tree * tp, int *walk_subtrees, void *data) | |
3514 | { | |
3515 | htab_t htab = (htab_t) data; | |
3516 | void **slot; | |
3517 | ||
3518 | if (tree_node_can_be_shared (*tp)) | |
3519 | { | |
3520 | *walk_subtrees = false; | |
3521 | return NULL; | |
3522 | } | |
3523 | ||
3524 | slot = htab_find_slot (htab, *tp, INSERT); | |
3525 | if (*slot) | |
858904db | 3526 | return (tree) *slot; |
6de9cd9a DN |
3527 | *slot = *tp; |
3528 | ||
3529 | return NULL; | |
3530 | } | |
3531 | ||
3532 | ||
3533 | /* Verify the GIMPLE statement chain. */ | |
3534 | ||
3535 | void | |
3536 | verify_stmts (void) | |
3537 | { | |
3538 | basic_block bb; | |
3539 | block_stmt_iterator bsi; | |
3540 | bool err = false; | |
3541 | htab_t htab; | |
3542 | tree addr; | |
3543 | ||
3544 | timevar_push (TV_TREE_STMT_VERIFY); | |
3545 | htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL); | |
3546 | ||
3547 | FOR_EACH_BB (bb) | |
3548 | { | |
3549 | tree phi; | |
3550 | int i; | |
3551 | ||
17192884 | 3552 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
3553 | { |
3554 | int phi_num_args = PHI_NUM_ARGS (phi); | |
3555 | ||
8de1fc1b KH |
3556 | if (bb_for_stmt (phi) != bb) |
3557 | { | |
ab532386 | 3558 | error ("bb_for_stmt (phi) is set to a wrong basic block"); |
8de1fc1b KH |
3559 | err |= true; |
3560 | } | |
3561 | ||
6de9cd9a DN |
3562 | for (i = 0; i < phi_num_args; i++) |
3563 | { | |
3564 | tree t = PHI_ARG_DEF (phi, i); | |
3565 | tree addr; | |
3566 | ||
3567 | /* Addressable variables do have SSA_NAMEs but they | |
3568 | are not considered gimple values. */ | |
3569 | if (TREE_CODE (t) != SSA_NAME | |
3570 | && TREE_CODE (t) != FUNCTION_DECL | |
3571 | && !is_gimple_val (t)) | |
3572 | { | |
3573 | error ("PHI def is not a GIMPLE value"); | |
3574 | debug_generic_stmt (phi); | |
3575 | debug_generic_stmt (t); | |
3576 | err |= true; | |
3577 | } | |
3578 | ||
7a442a1d | 3579 | addr = walk_tree (&t, verify_expr, (void *) 1, NULL); |
6de9cd9a DN |
3580 | if (addr) |
3581 | { | |
3582 | debug_generic_stmt (addr); | |
3583 | err |= true; | |
3584 | } | |
3585 | ||
3586 | addr = walk_tree (&t, verify_node_sharing, htab, NULL); | |
3587 | if (addr) | |
3588 | { | |
ab532386 | 3589 | error ("incorrect sharing of tree nodes"); |
6de9cd9a DN |
3590 | debug_generic_stmt (phi); |
3591 | debug_generic_stmt (addr); | |
3592 | err |= true; | |
3593 | } | |
3594 | } | |
3595 | } | |
3596 | ||
1eaba2f2 | 3597 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); ) |
6de9cd9a DN |
3598 | { |
3599 | tree stmt = bsi_stmt (bsi); | |
8de1fc1b KH |
3600 | |
3601 | if (bb_for_stmt (stmt) != bb) | |
3602 | { | |
ab532386 | 3603 | error ("bb_for_stmt (stmt) is set to a wrong basic block"); |
8de1fc1b KH |
3604 | err |= true; |
3605 | } | |
3606 | ||
1eaba2f2 RH |
3607 | bsi_next (&bsi); |
3608 | err |= verify_stmt (stmt, bsi_end_p (bsi)); | |
6de9cd9a DN |
3609 | addr = walk_tree (&stmt, verify_node_sharing, htab, NULL); |
3610 | if (addr) | |
3611 | { | |
ab532386 | 3612 | error ("incorrect sharing of tree nodes"); |
6de9cd9a DN |
3613 | debug_generic_stmt (stmt); |
3614 | debug_generic_stmt (addr); | |
3615 | err |= true; | |
3616 | } | |
3617 | } | |
3618 | } | |
3619 | ||
3620 | if (err) | |
ab532386 | 3621 | internal_error ("verify_stmts failed"); |
6de9cd9a DN |
3622 | |
3623 | htab_delete (htab); | |
3624 | timevar_pop (TV_TREE_STMT_VERIFY); | |
3625 | } | |
3626 | ||
3627 | ||
3628 | /* Verifies that the flow information is OK. */ | |
3629 | ||
3630 | static int | |
3631 | tree_verify_flow_info (void) | |
3632 | { | |
3633 | int err = 0; | |
3634 | basic_block bb; | |
3635 | block_stmt_iterator bsi; | |
3636 | tree stmt; | |
3637 | edge e; | |
628f6a4e | 3638 | edge_iterator ei; |
6de9cd9a DN |
3639 | |
3640 | if (ENTRY_BLOCK_PTR->stmt_list) | |
3641 | { | |
ab532386 | 3642 | error ("ENTRY_BLOCK has a statement list associated with it"); |
6de9cd9a DN |
3643 | err = 1; |
3644 | } | |
3645 | ||
3646 | if (EXIT_BLOCK_PTR->stmt_list) | |
3647 | { | |
ab532386 | 3648 | error ("EXIT_BLOCK has a statement list associated with it"); |
6de9cd9a DN |
3649 | err = 1; |
3650 | } | |
3651 | ||
628f6a4e | 3652 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds) |
6de9cd9a DN |
3653 | if (e->flags & EDGE_FALLTHRU) |
3654 | { | |
ab532386 | 3655 | error ("fallthru to exit from bb %d", e->src->index); |
6de9cd9a DN |
3656 | err = 1; |
3657 | } | |
3658 | ||
3659 | FOR_EACH_BB (bb) | |
3660 | { | |
3661 | bool found_ctrl_stmt = false; | |
3662 | ||
548414c6 KH |
3663 | stmt = NULL_TREE; |
3664 | ||
6de9cd9a DN |
3665 | /* Skip labels on the start of basic block. */ |
3666 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
3667 | { | |
548414c6 KH |
3668 | tree prev_stmt = stmt; |
3669 | ||
3670 | stmt = bsi_stmt (bsi); | |
3671 | ||
3672 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
6de9cd9a DN |
3673 | break; |
3674 | ||
548414c6 KH |
3675 | if (prev_stmt && DECL_NONLOCAL (LABEL_EXPR_LABEL (stmt))) |
3676 | { | |
953ff289 DN |
3677 | error ("nonlocal label "); |
3678 | print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0); | |
3679 | fprintf (stderr, " is not first in a sequence of labels in bb %d", | |
3680 | bb->index); | |
548414c6 KH |
3681 | err = 1; |
3682 | } | |
3683 | ||
3684 | if (label_to_block (LABEL_EXPR_LABEL (stmt)) != bb) | |
6de9cd9a | 3685 | { |
953ff289 DN |
3686 | error ("label "); |
3687 | print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0); | |
3688 | fprintf (stderr, " to block does not match in bb %d", | |
3689 | bb->index); | |
6de9cd9a DN |
3690 | err = 1; |
3691 | } | |
3692 | ||
548414c6 | 3693 | if (decl_function_context (LABEL_EXPR_LABEL (stmt)) |
6de9cd9a DN |
3694 | != current_function_decl) |
3695 | { | |
953ff289 DN |
3696 | error ("label "); |
3697 | print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0); | |
3698 | fprintf (stderr, " has incorrect context in bb %d", | |
3699 | bb->index); | |
6de9cd9a DN |
3700 | err = 1; |
3701 | } | |
3702 | } | |
3703 | ||
3704 | /* Verify that body of basic block BB is free of control flow. */ | |
3705 | for (; !bsi_end_p (bsi); bsi_next (&bsi)) | |
3706 | { | |
3707 | tree stmt = bsi_stmt (bsi); | |
3708 | ||
3709 | if (found_ctrl_stmt) | |
3710 | { | |
ab532386 | 3711 | error ("control flow in the middle of basic block %d", |
6de9cd9a DN |
3712 | bb->index); |
3713 | err = 1; | |
3714 | } | |
3715 | ||
3716 | if (stmt_ends_bb_p (stmt)) | |
3717 | found_ctrl_stmt = true; | |
3718 | ||
3719 | if (TREE_CODE (stmt) == LABEL_EXPR) | |
3720 | { | |
953ff289 DN |
3721 | error ("label "); |
3722 | print_generic_expr (stderr, LABEL_EXPR_LABEL (stmt), 0); | |
3723 | fprintf (stderr, " in the middle of basic block %d", bb->index); | |
6de9cd9a DN |
3724 | err = 1; |
3725 | } | |
3726 | } | |
953ff289 | 3727 | |
6de9cd9a DN |
3728 | bsi = bsi_last (bb); |
3729 | if (bsi_end_p (bsi)) | |
3730 | continue; | |
3731 | ||
3732 | stmt = bsi_stmt (bsi); | |
3733 | ||
cc7220fd JH |
3734 | err |= verify_eh_edges (stmt); |
3735 | ||
6de9cd9a DN |
3736 | if (is_ctrl_stmt (stmt)) |
3737 | { | |
628f6a4e | 3738 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
3739 | if (e->flags & EDGE_FALLTHRU) |
3740 | { | |
ab532386 | 3741 | error ("fallthru edge after a control statement in bb %d", |
6de9cd9a DN |
3742 | bb->index); |
3743 | err = 1; | |
3744 | } | |
3745 | } | |
3746 | ||
3747 | switch (TREE_CODE (stmt)) | |
3748 | { | |
3749 | case COND_EXPR: | |
3750 | { | |
3751 | edge true_edge; | |
3752 | edge false_edge; | |
3753 | if (TREE_CODE (COND_EXPR_THEN (stmt)) != GOTO_EXPR | |
3754 | || TREE_CODE (COND_EXPR_ELSE (stmt)) != GOTO_EXPR) | |
3755 | { | |
ab532386 | 3756 | error ("structured COND_EXPR at the end of bb %d", bb->index); |
6de9cd9a DN |
3757 | err = 1; |
3758 | } | |
3759 | ||
3760 | extract_true_false_edges_from_block (bb, &true_edge, &false_edge); | |
3761 | ||
3762 | if (!true_edge || !false_edge | |
3763 | || !(true_edge->flags & EDGE_TRUE_VALUE) | |
3764 | || !(false_edge->flags & EDGE_FALSE_VALUE) | |
3765 | || (true_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL)) | |
3766 | || (false_edge->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL)) | |
628f6a4e | 3767 | || EDGE_COUNT (bb->succs) >= 3) |
6de9cd9a | 3768 | { |
ab532386 | 3769 | error ("wrong outgoing edge flags at end of bb %d", |
6de9cd9a DN |
3770 | bb->index); |
3771 | err = 1; | |
3772 | } | |
3773 | ||
3774 | if (!has_label_p (true_edge->dest, | |
3775 | GOTO_DESTINATION (COND_EXPR_THEN (stmt)))) | |
3776 | { | |
ab532386 | 3777 | error ("%<then%> label does not match edge at end of bb %d", |
6de9cd9a DN |
3778 | bb->index); |
3779 | err = 1; | |
3780 | } | |
3781 | ||
3782 | if (!has_label_p (false_edge->dest, | |
3783 | GOTO_DESTINATION (COND_EXPR_ELSE (stmt)))) | |
3784 | { | |
ab532386 | 3785 | error ("%<else%> label does not match edge at end of bb %d", |
6de9cd9a DN |
3786 | bb->index); |
3787 | err = 1; | |
3788 | } | |
3789 | } | |
3790 | break; | |
3791 | ||
3792 | case GOTO_EXPR: | |
3793 | if (simple_goto_p (stmt)) | |
3794 | { | |
ab532386 | 3795 | error ("explicit goto at end of bb %d", bb->index); |
6de9cd9a DN |
3796 | err = 1; |
3797 | } | |
3798 | else | |
3799 | { | |
3800 | /* FIXME. We should double check that the labels in the | |
3801 | destination blocks have their address taken. */ | |
628f6a4e | 3802 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
3803 | if ((e->flags & (EDGE_FALLTHRU | EDGE_TRUE_VALUE |
3804 | | EDGE_FALSE_VALUE)) | |
3805 | || !(e->flags & EDGE_ABNORMAL)) | |
3806 | { | |
ab532386 | 3807 | error ("wrong outgoing edge flags at end of bb %d", |
6de9cd9a DN |
3808 | bb->index); |
3809 | err = 1; | |
3810 | } | |
3811 | } | |
3812 | break; | |
3813 | ||
3814 | case RETURN_EXPR: | |
c5cbcccf ZD |
3815 | if (!single_succ_p (bb) |
3816 | || (single_succ_edge (bb)->flags | |
3817 | & (EDGE_FALLTHRU | EDGE_ABNORMAL | |
3818 | | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))) | |
6de9cd9a | 3819 | { |
ab532386 | 3820 | error ("wrong outgoing edge flags at end of bb %d", bb->index); |
6de9cd9a DN |
3821 | err = 1; |
3822 | } | |
c5cbcccf | 3823 | if (single_succ (bb) != EXIT_BLOCK_PTR) |
6de9cd9a | 3824 | { |
ab532386 | 3825 | error ("return edge does not point to exit in bb %d", |
6de9cd9a DN |
3826 | bb->index); |
3827 | err = 1; | |
3828 | } | |
3829 | break; | |
3830 | ||
3831 | case SWITCH_EXPR: | |
3832 | { | |
7853504d | 3833 | tree prev; |
6de9cd9a DN |
3834 | edge e; |
3835 | size_t i, n; | |
3836 | tree vec; | |
3837 | ||
3838 | vec = SWITCH_LABELS (stmt); | |
3839 | n = TREE_VEC_LENGTH (vec); | |
3840 | ||
3841 | /* Mark all the destination basic blocks. */ | |
3842 | for (i = 0; i < n; ++i) | |
3843 | { | |
3844 | tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i)); | |
3845 | basic_block label_bb = label_to_block (lab); | |
3846 | ||
1e128c5f | 3847 | gcc_assert (!label_bb->aux || label_bb->aux == (void *)1); |
6de9cd9a DN |
3848 | label_bb->aux = (void *)1; |
3849 | } | |
3850 | ||
7853504d SB |
3851 | /* Verify that the case labels are sorted. */ |
3852 | prev = TREE_VEC_ELT (vec, 0); | |
3853 | for (i = 1; i < n - 1; ++i) | |
3854 | { | |
3855 | tree c = TREE_VEC_ELT (vec, i); | |
3856 | if (! CASE_LOW (c)) | |
3857 | { | |
ab532386 | 3858 | error ("found default case not at end of case vector"); |
7853504d SB |
3859 | err = 1; |
3860 | continue; | |
3861 | } | |
3862 | if (! tree_int_cst_lt (CASE_LOW (prev), CASE_LOW (c))) | |
3863 | { | |
953ff289 | 3864 | error ("case labels not sorted: "); |
7853504d SB |
3865 | print_generic_expr (stderr, prev, 0); |
3866 | fprintf (stderr," is greater than "); | |
3867 | print_generic_expr (stderr, c, 0); | |
3868 | fprintf (stderr," but comes before it.\n"); | |
3869 | err = 1; | |
3870 | } | |
3871 | prev = c; | |
3872 | } | |
3873 | if (CASE_LOW (TREE_VEC_ELT (vec, n - 1))) | |
3874 | { | |
ab532386 | 3875 | error ("no default case found at end of case vector"); |
7853504d SB |
3876 | err = 1; |
3877 | } | |
3878 | ||
628f6a4e | 3879 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
3880 | { |
3881 | if (!e->dest->aux) | |
3882 | { | |
ab532386 | 3883 | error ("extra outgoing edge %d->%d", |
6de9cd9a DN |
3884 | bb->index, e->dest->index); |
3885 | err = 1; | |
3886 | } | |
3887 | e->dest->aux = (void *)2; | |
3888 | if ((e->flags & (EDGE_FALLTHRU | EDGE_ABNORMAL | |
3889 | | EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))) | |
3890 | { | |
ab532386 | 3891 | error ("wrong outgoing edge flags at end of bb %d", |
6de9cd9a DN |
3892 | bb->index); |
3893 | err = 1; | |
3894 | } | |
3895 | } | |
3896 | ||
3897 | /* Check that we have all of them. */ | |
3898 | for (i = 0; i < n; ++i) | |
3899 | { | |
3900 | tree lab = CASE_LABEL (TREE_VEC_ELT (vec, i)); | |
3901 | basic_block label_bb = label_to_block (lab); | |
3902 | ||
3903 | if (label_bb->aux != (void *)2) | |
3904 | { | |
ab532386 | 3905 | error ("missing edge %i->%i", |
6de9cd9a DN |
3906 | bb->index, label_bb->index); |
3907 | err = 1; | |
3908 | } | |
3909 | } | |
3910 | ||
628f6a4e | 3911 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
3912 | e->dest->aux = (void *)0; |
3913 | } | |
3914 | ||
3915 | default: ; | |
3916 | } | |
3917 | } | |
3918 | ||
3919 | if (dom_computed[CDI_DOMINATORS] >= DOM_NO_FAST_QUERY) | |
3920 | verify_dominators (CDI_DOMINATORS); | |
3921 | ||
3922 | return err; | |
3923 | } | |
3924 | ||
3925 | ||
f0b698c1 | 3926 | /* Updates phi nodes after creating a forwarder block joined |
6de9cd9a DN |
3927 | by edge FALLTHRU. */ |
3928 | ||
3929 | static void | |
3930 | tree_make_forwarder_block (edge fallthru) | |
3931 | { | |
3932 | edge e; | |
628f6a4e | 3933 | edge_iterator ei; |
6de9cd9a | 3934 | basic_block dummy, bb; |
5ae71719 | 3935 | tree phi, new_phi, var; |
6de9cd9a DN |
3936 | |
3937 | dummy = fallthru->src; | |
3938 | bb = fallthru->dest; | |
3939 | ||
c5cbcccf | 3940 | if (single_pred_p (bb)) |
6de9cd9a DN |
3941 | return; |
3942 | ||
3943 | /* If we redirected a branch we must create new phi nodes at the | |
3944 | start of BB. */ | |
17192884 | 3945 | for (phi = phi_nodes (dummy); phi; phi = PHI_CHAIN (phi)) |
6de9cd9a DN |
3946 | { |
3947 | var = PHI_RESULT (phi); | |
3948 | new_phi = create_phi_node (var, bb); | |
3949 | SSA_NAME_DEF_STMT (var) = new_phi; | |
d00ad49b | 3950 | SET_PHI_RESULT (phi, make_ssa_name (SSA_NAME_VAR (var), phi)); |
d2e398df | 3951 | add_phi_arg (new_phi, PHI_RESULT (phi), fallthru); |
6de9cd9a DN |
3952 | } |
3953 | ||
17192884 | 3954 | /* Ensure that the PHI node chain is in the same order. */ |
5ae71719 | 3955 | set_phi_nodes (bb, phi_reverse (phi_nodes (bb))); |
6de9cd9a DN |
3956 | |
3957 | /* Add the arguments we have stored on edges. */ | |
628f6a4e | 3958 | FOR_EACH_EDGE (e, ei, bb->preds) |
6de9cd9a DN |
3959 | { |
3960 | if (e == fallthru) | |
3961 | continue; | |
3962 | ||
71882046 | 3963 | flush_pending_stmts (e); |
6de9cd9a DN |
3964 | } |
3965 | } | |
3966 | ||
3967 | ||
6de9cd9a DN |
3968 | /* Return a non-special label in the head of basic block BLOCK. |
3969 | Create one if it doesn't exist. */ | |
3970 | ||
d7621d3c | 3971 | tree |
6de9cd9a DN |
3972 | tree_block_label (basic_block bb) |
3973 | { | |
3974 | block_stmt_iterator i, s = bsi_start (bb); | |
3975 | bool first = true; | |
3976 | tree label, stmt; | |
3977 | ||
3978 | for (i = s; !bsi_end_p (i); first = false, bsi_next (&i)) | |
3979 | { | |
3980 | stmt = bsi_stmt (i); | |
3981 | if (TREE_CODE (stmt) != LABEL_EXPR) | |
3982 | break; | |
3983 | label = LABEL_EXPR_LABEL (stmt); | |
3984 | if (!DECL_NONLOCAL (label)) | |
3985 | { | |
3986 | if (!first) | |
3987 | bsi_move_before (&i, &s); | |
3988 | return label; | |
3989 | } | |
3990 | } | |
3991 | ||
3992 | label = create_artificial_label (); | |
3993 | stmt = build1 (LABEL_EXPR, void_type_node, label); | |
3994 | bsi_insert_before (&s, stmt, BSI_NEW_STMT); | |
3995 | return label; | |
3996 | } | |
3997 | ||
3998 | ||
3999 | /* Attempt to perform edge redirection by replacing a possibly complex | |
4000 | jump instruction by a goto or by removing the jump completely. | |
4001 | This can apply only if all edges now point to the same block. The | |
4002 | parameters and return values are equivalent to | |
4003 | redirect_edge_and_branch. */ | |
4004 | ||
4005 | static edge | |
4006 | tree_try_redirect_by_replacing_jump (edge e, basic_block target) | |
4007 | { | |
4008 | basic_block src = e->src; | |
6de9cd9a DN |
4009 | block_stmt_iterator b; |
4010 | tree stmt; | |
6de9cd9a | 4011 | |
07b43a87 KH |
4012 | /* We can replace or remove a complex jump only when we have exactly |
4013 | two edges. */ | |
4014 | if (EDGE_COUNT (src->succs) != 2 | |
4015 | /* Verify that all targets will be TARGET. Specifically, the | |
4016 | edge that is not E must also go to TARGET. */ | |
4017 | || EDGE_SUCC (src, EDGE_SUCC (src, 0) == e)->dest != target) | |
6de9cd9a DN |
4018 | return NULL; |
4019 | ||
4020 | b = bsi_last (src); | |
4021 | if (bsi_end_p (b)) | |
4022 | return NULL; | |
4023 | stmt = bsi_stmt (b); | |
4024 | ||
4025 | if (TREE_CODE (stmt) == COND_EXPR | |
4026 | || TREE_CODE (stmt) == SWITCH_EXPR) | |
4027 | { | |
736432ee | 4028 | bsi_remove (&b, true); |
6de9cd9a DN |
4029 | e = ssa_redirect_edge (e, target); |
4030 | e->flags = EDGE_FALLTHRU; | |
4031 | return e; | |
4032 | } | |
4033 | ||
4034 | return NULL; | |
4035 | } | |
4036 | ||
4037 | ||
4038 | /* Redirect E to DEST. Return NULL on failure. Otherwise, return the | |
4039 | edge representing the redirected branch. */ | |
4040 | ||
4041 | static edge | |
4042 | tree_redirect_edge_and_branch (edge e, basic_block dest) | |
4043 | { | |
4044 | basic_block bb = e->src; | |
4045 | block_stmt_iterator bsi; | |
4046 | edge ret; | |
4047 | tree label, stmt; | |
4048 | ||
4049 | if (e->flags & (EDGE_ABNORMAL_CALL | EDGE_EH)) | |
4050 | return NULL; | |
4051 | ||
4052 | if (e->src != ENTRY_BLOCK_PTR | |
4053 | && (ret = tree_try_redirect_by_replacing_jump (e, dest))) | |
4054 | return ret; | |
4055 | ||
4056 | if (e->dest == dest) | |
4057 | return NULL; | |
4058 | ||
4059 | label = tree_block_label (dest); | |
4060 | ||
4061 | bsi = bsi_last (bb); | |
4062 | stmt = bsi_end_p (bsi) ? NULL : bsi_stmt (bsi); | |
4063 | ||
4064 | switch (stmt ? TREE_CODE (stmt) : ERROR_MARK) | |
4065 | { | |
4066 | case COND_EXPR: | |
4067 | stmt = (e->flags & EDGE_TRUE_VALUE | |
4068 | ? COND_EXPR_THEN (stmt) | |
4069 | : COND_EXPR_ELSE (stmt)); | |
4070 | GOTO_DESTINATION (stmt) = label; | |
4071 | break; | |
4072 | ||
4073 | case GOTO_EXPR: | |
4074 | /* No non-abnormal edges should lead from a non-simple goto, and | |
4075 | simple ones should be represented implicitly. */ | |
1e128c5f | 4076 | gcc_unreachable (); |
6de9cd9a DN |
4077 | |
4078 | case SWITCH_EXPR: | |
4079 | { | |
d6be0d7f | 4080 | tree cases = get_cases_for_edge (e, stmt); |
6de9cd9a | 4081 | |
d6be0d7f JL |
4082 | /* If we have a list of cases associated with E, then use it |
4083 | as it's a lot faster than walking the entire case vector. */ | |
4084 | if (cases) | |
6de9cd9a | 4085 | { |
4edbbd3f | 4086 | edge e2 = find_edge (e->src, dest); |
d6be0d7f JL |
4087 | tree last, first; |
4088 | ||
4089 | first = cases; | |
4090 | while (cases) | |
4091 | { | |
4092 | last = cases; | |
4093 | CASE_LABEL (cases) = label; | |
4094 | cases = TREE_CHAIN (cases); | |
4095 | } | |
4096 | ||
4097 | /* If there was already an edge in the CFG, then we need | |
4098 | to move all the cases associated with E to E2. */ | |
4099 | if (e2) | |
4100 | { | |
4101 | tree cases2 = get_cases_for_edge (e2, stmt); | |
4102 | ||
4103 | TREE_CHAIN (last) = TREE_CHAIN (cases2); | |
4104 | TREE_CHAIN (cases2) = first; | |
4105 | } | |
6de9cd9a | 4106 | } |
92b6dff3 JL |
4107 | else |
4108 | { | |
d6be0d7f JL |
4109 | tree vec = SWITCH_LABELS (stmt); |
4110 | size_t i, n = TREE_VEC_LENGTH (vec); | |
4111 | ||
4112 | for (i = 0; i < n; i++) | |
4113 | { | |
4114 | tree elt = TREE_VEC_ELT (vec, i); | |
4115 | ||
4116 | if (label_to_block (CASE_LABEL (elt)) == e->dest) | |
4117 | CASE_LABEL (elt) = label; | |
4118 | } | |
92b6dff3 | 4119 | } |
d6be0d7f | 4120 | |
92b6dff3 | 4121 | break; |
6de9cd9a | 4122 | } |
6de9cd9a DN |
4123 | |
4124 | case RETURN_EXPR: | |
736432ee | 4125 | bsi_remove (&bsi, true); |
6de9cd9a DN |
4126 | e->flags |= EDGE_FALLTHRU; |
4127 | break; | |
4128 | ||
4129 | default: | |
4130 | /* Otherwise it must be a fallthru edge, and we don't need to | |
4131 | do anything besides redirecting it. */ | |
1e128c5f | 4132 | gcc_assert (e->flags & EDGE_FALLTHRU); |
6de9cd9a DN |
4133 | break; |
4134 | } | |
4135 | ||
4136 | /* Update/insert PHI nodes as necessary. */ | |
4137 | ||
4138 | /* Now update the edges in the CFG. */ | |
4139 | e = ssa_redirect_edge (e, dest); | |
4140 | ||
4141 | return e; | |
4142 | } | |
4143 | ||
4144 | ||
4145 | /* Simple wrapper, as we can always redirect fallthru edges. */ | |
4146 | ||
4147 | static basic_block | |
4148 | tree_redirect_edge_and_branch_force (edge e, basic_block dest) | |
4149 | { | |
4150 | e = tree_redirect_edge_and_branch (e, dest); | |
1e128c5f | 4151 | gcc_assert (e); |
6de9cd9a DN |
4152 | |
4153 | return NULL; | |
4154 | } | |
4155 | ||
4156 | ||
4157 | /* Splits basic block BB after statement STMT (but at least after the | |
4158 | labels). If STMT is NULL, BB is split just after the labels. */ | |
4159 | ||
4160 | static basic_block | |
4161 | tree_split_block (basic_block bb, void *stmt) | |
4162 | { | |
4163 | block_stmt_iterator bsi, bsi_tgt; | |
4164 | tree act; | |
4165 | basic_block new_bb; | |
4166 | edge e; | |
628f6a4e | 4167 | edge_iterator ei; |
6de9cd9a DN |
4168 | |
4169 | new_bb = create_empty_bb (bb); | |
4170 | ||
4171 | /* Redirect the outgoing edges. */ | |
628f6a4e BE |
4172 | new_bb->succs = bb->succs; |
4173 | bb->succs = NULL; | |
4174 | FOR_EACH_EDGE (e, ei, new_bb->succs) | |
6de9cd9a DN |
4175 | e->src = new_bb; |
4176 | ||
4177 | if (stmt && TREE_CODE ((tree) stmt) == LABEL_EXPR) | |
4178 | stmt = NULL; | |
4179 | ||
4180 | /* Move everything from BSI to the new basic block. */ | |
4181 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
4182 | { | |
4183 | act = bsi_stmt (bsi); | |
4184 | if (TREE_CODE (act) == LABEL_EXPR) | |
4185 | continue; | |
4186 | ||
4187 | if (!stmt) | |
4188 | break; | |
4189 | ||
4190 | if (stmt == act) | |
4191 | { | |
4192 | bsi_next (&bsi); | |
4193 | break; | |
4194 | } | |
4195 | } | |
4196 | ||
4197 | bsi_tgt = bsi_start (new_bb); | |
4198 | while (!bsi_end_p (bsi)) | |
4199 | { | |
4200 | act = bsi_stmt (bsi); | |
736432ee | 4201 | bsi_remove (&bsi, false); |
6de9cd9a DN |
4202 | bsi_insert_after (&bsi_tgt, act, BSI_NEW_STMT); |
4203 | } | |
4204 | ||
4205 | return new_bb; | |
4206 | } | |
4207 | ||
4208 | ||
4209 | /* Moves basic block BB after block AFTER. */ | |
4210 | ||
4211 | static bool | |
4212 | tree_move_block_after (basic_block bb, basic_block after) | |
4213 | { | |
4214 | if (bb->prev_bb == after) | |
4215 | return true; | |
4216 | ||
4217 | unlink_block (bb); | |
4218 | link_block (bb, after); | |
4219 | ||
4220 | return true; | |
4221 | } | |
4222 | ||
4223 | ||
4224 | /* Return true if basic_block can be duplicated. */ | |
4225 | ||
4226 | static bool | |
4227 | tree_can_duplicate_bb_p (basic_block bb ATTRIBUTE_UNUSED) | |
4228 | { | |
4229 | return true; | |
4230 | } | |
4231 | ||
84d65814 | 4232 | |
6de9cd9a DN |
4233 | /* Create a duplicate of the basic block BB. NOTE: This does not |
4234 | preserve SSA form. */ | |
4235 | ||
4236 | static basic_block | |
4237 | tree_duplicate_bb (basic_block bb) | |
4238 | { | |
4239 | basic_block new_bb; | |
4240 | block_stmt_iterator bsi, bsi_tgt; | |
84d65814 | 4241 | tree phi; |
6de9cd9a DN |
4242 | |
4243 | new_bb = create_empty_bb (EXIT_BLOCK_PTR->prev_bb); | |
b0382c67 | 4244 | |
84d65814 DN |
4245 | /* Copy the PHI nodes. We ignore PHI node arguments here because |
4246 | the incoming edges have not been setup yet. */ | |
bb29d951 | 4247 | for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi)) |
b0382c67 | 4248 | { |
84d65814 DN |
4249 | tree copy = create_phi_node (PHI_RESULT (phi), new_bb); |
4250 | create_new_def_for (PHI_RESULT (copy), copy, PHI_RESULT_PTR (copy)); | |
b0382c67 | 4251 | } |
84d65814 DN |
4252 | |
4253 | /* Keep the chain of PHI nodes in the same order so that they can be | |
4254 | updated by ssa_redirect_edge. */ | |
5ae71719 | 4255 | set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb))); |
b0382c67 | 4256 | |
6de9cd9a DN |
4257 | bsi_tgt = bsi_start (new_bb); |
4258 | for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) | |
4259 | { | |
84d65814 DN |
4260 | def_operand_p def_p; |
4261 | ssa_op_iter op_iter; | |
4262 | tree stmt, copy; | |
cc7220fd | 4263 | int region; |
6de9cd9a | 4264 | |
84d65814 | 4265 | stmt = bsi_stmt (bsi); |
6de9cd9a DN |
4266 | if (TREE_CODE (stmt) == LABEL_EXPR) |
4267 | continue; | |
4268 | ||
84d65814 DN |
4269 | /* Create a new copy of STMT and duplicate STMT's virtual |
4270 | operands. */ | |
5f240ec4 | 4271 | copy = unshare_expr (stmt); |
5f240ec4 | 4272 | bsi_insert_after (&bsi_tgt, copy, BSI_NEW_STMT); |
84d65814 | 4273 | copy_virtual_operands (copy, stmt); |
cc7220fd JH |
4274 | region = lookup_stmt_eh_region (stmt); |
4275 | if (region >= 0) | |
4276 | add_stmt_to_eh_region (copy, region); | |
84d65814 DN |
4277 | |
4278 | /* Create new names for all the definitions created by COPY and | |
4279 | add replacement mappings for each new name. */ | |
4280 | FOR_EACH_SSA_DEF_OPERAND (def_p, copy, op_iter, SSA_OP_ALL_DEFS) | |
4281 | create_new_def_for (DEF_FROM_PTR (def_p), copy, def_p); | |
6de9cd9a DN |
4282 | } |
4283 | ||
4284 | return new_bb; | |
4285 | } | |
4286 | ||
84d65814 | 4287 | |
42759f1e ZD |
4288 | /* Basic block BB_COPY was created by code duplication. Add phi node |
4289 | arguments for edges going out of BB_COPY. The blocks that were | |
6580ee77 | 4290 | duplicated have BB_DUPLICATED set. */ |
42759f1e ZD |
4291 | |
4292 | void | |
4293 | add_phi_args_after_copy_bb (basic_block bb_copy) | |
4294 | { | |
4295 | basic_block bb, dest; | |
4296 | edge e, e_copy; | |
628f6a4e | 4297 | edge_iterator ei; |
42759f1e ZD |
4298 | tree phi, phi_copy, phi_next, def; |
4299 | ||
6580ee77 | 4300 | bb = get_bb_original (bb_copy); |
42759f1e | 4301 | |
628f6a4e | 4302 | FOR_EACH_EDGE (e_copy, ei, bb_copy->succs) |
42759f1e ZD |
4303 | { |
4304 | if (!phi_nodes (e_copy->dest)) | |
4305 | continue; | |
4306 | ||
6580ee77 JH |
4307 | if (e_copy->dest->flags & BB_DUPLICATED) |
4308 | dest = get_bb_original (e_copy->dest); | |
42759f1e ZD |
4309 | else |
4310 | dest = e_copy->dest; | |
4311 | ||
4312 | e = find_edge (bb, dest); | |
4313 | if (!e) | |
4314 | { | |
4315 | /* During loop unrolling the target of the latch edge is copied. | |
4316 | In this case we are not looking for edge to dest, but to | |
4317 | duplicated block whose original was dest. */ | |
628f6a4e | 4318 | FOR_EACH_EDGE (e, ei, bb->succs) |
6580ee77 JH |
4319 | if ((e->dest->flags & BB_DUPLICATED) |
4320 | && get_bb_original (e->dest) == dest) | |
42759f1e ZD |
4321 | break; |
4322 | ||
4323 | gcc_assert (e != NULL); | |
4324 | } | |
4325 | ||
4326 | for (phi = phi_nodes (e->dest), phi_copy = phi_nodes (e_copy->dest); | |
4327 | phi; | |
eaf0dc02 | 4328 | phi = phi_next, phi_copy = PHI_CHAIN (phi_copy)) |
42759f1e | 4329 | { |
eaf0dc02 | 4330 | phi_next = PHI_CHAIN (phi); |
42759f1e | 4331 | def = PHI_ARG_DEF_FROM_EDGE (phi, e); |
d2e398df | 4332 | add_phi_arg (phi_copy, def, e_copy); |
42759f1e ZD |
4333 | } |
4334 | } | |
4335 | } | |
4336 | ||
4337 | /* Blocks in REGION_COPY array of length N_REGION were created by | |
4338 | duplication of basic blocks. Add phi node arguments for edges | |
4339 | going from these blocks. */ | |
4340 | ||
4341 | void | |
4342 | add_phi_args_after_copy (basic_block *region_copy, unsigned n_region) | |
4343 | { | |
4344 | unsigned i; | |
4345 | ||
4346 | for (i = 0; i < n_region; i++) | |
6580ee77 | 4347 | region_copy[i]->flags |= BB_DUPLICATED; |
42759f1e ZD |
4348 | |
4349 | for (i = 0; i < n_region; i++) | |
4350 | add_phi_args_after_copy_bb (region_copy[i]); | |
4351 | ||
4352 | for (i = 0; i < n_region; i++) | |
6580ee77 | 4353 | region_copy[i]->flags &= ~BB_DUPLICATED; |
42759f1e ZD |
4354 | } |
4355 | ||
42759f1e ZD |
4356 | /* Duplicates a REGION (set of N_REGION basic blocks) with just a single |
4357 | important exit edge EXIT. By important we mean that no SSA name defined | |
4358 | inside region is live over the other exit edges of the region. All entry | |
4359 | edges to the region must go to ENTRY->dest. The edge ENTRY is redirected | |
4360 | to the duplicate of the region. SSA form, dominance and loop information | |
4361 | is updated. The new basic blocks are stored to REGION_COPY in the same | |
4362 | order as they had in REGION, provided that REGION_COPY is not NULL. | |
4363 | The function returns false if it is unable to copy the region, | |
4364 | true otherwise. */ | |
4365 | ||
4366 | bool | |
4367 | tree_duplicate_sese_region (edge entry, edge exit, | |
4368 | basic_block *region, unsigned n_region, | |
4369 | basic_block *region_copy) | |
4370 | { | |
84d65814 | 4371 | unsigned i, n_doms; |
42759f1e ZD |
4372 | bool free_region_copy = false, copying_header = false; |
4373 | struct loop *loop = entry->dest->loop_father; | |
4374 | edge exit_copy; | |
42759f1e | 4375 | basic_block *doms; |
42759f1e | 4376 | edge redirected; |
09bac500 JH |
4377 | int total_freq = 0, entry_freq = 0; |
4378 | gcov_type total_count = 0, entry_count = 0; | |
42759f1e ZD |
4379 | |
4380 | if (!can_copy_bbs_p (region, n_region)) | |
4381 | return false; | |
4382 | ||
4383 | /* Some sanity checking. Note that we do not check for all possible | |
4384 | missuses of the functions. I.e. if you ask to copy something weird, | |
4385 | it will work, but the state of structures probably will not be | |
4386 | correct. */ | |
42759f1e ZD |
4387 | for (i = 0; i < n_region; i++) |
4388 | { | |
4389 | /* We do not handle subloops, i.e. all the blocks must belong to the | |
4390 | same loop. */ | |
4391 | if (region[i]->loop_father != loop) | |
4392 | return false; | |
4393 | ||
4394 | if (region[i] != entry->dest | |
4395 | && region[i] == loop->header) | |
4396 | return false; | |
4397 | } | |
4398 | ||
4399 | loop->copy = loop; | |
4400 | ||
4401 | /* In case the function is used for loop header copying (which is the primary | |
4402 | use), ensure that EXIT and its copy will be new latch and entry edges. */ | |
4403 | if (loop->header == entry->dest) | |
4404 | { | |
4405 | copying_header = true; | |
4406 | loop->copy = loop->outer; | |
4407 | ||
4408 | if (!dominated_by_p (CDI_DOMINATORS, loop->latch, exit->src)) | |
4409 | return false; | |
4410 | ||
4411 | for (i = 0; i < n_region; i++) | |
4412 | if (region[i] != exit->src | |
4413 | && dominated_by_p (CDI_DOMINATORS, region[i], exit->src)) | |
4414 | return false; | |
4415 | } | |
4416 | ||
4417 | if (!region_copy) | |
4418 | { | |
858904db | 4419 | region_copy = XNEWVEC (basic_block, n_region); |
42759f1e ZD |
4420 | free_region_copy = true; |
4421 | } | |
4422 | ||
84d65814 | 4423 | gcc_assert (!need_ssa_update_p ()); |
42759f1e | 4424 | |
5deaef19 | 4425 | /* Record blocks outside the region that are dominated by something |
42759f1e | 4426 | inside. */ |
858904db | 4427 | doms = XNEWVEC (basic_block, n_basic_blocks); |
6580ee77 JH |
4428 | initialize_original_copy_tables (); |
4429 | ||
42759f1e ZD |
4430 | n_doms = get_dominated_by_region (CDI_DOMINATORS, region, n_region, doms); |
4431 | ||
09bac500 JH |
4432 | if (entry->dest->count) |
4433 | { | |
4434 | total_count = entry->dest->count; | |
4435 | entry_count = entry->count; | |
4436 | /* Fix up corner cases, to avoid division by zero or creation of negative | |
4437 | frequencies. */ | |
4438 | if (entry_count > total_count) | |
4439 | entry_count = total_count; | |
4440 | } | |
4441 | else | |
4442 | { | |
4443 | total_freq = entry->dest->frequency; | |
4444 | entry_freq = EDGE_FREQUENCY (entry); | |
4445 | /* Fix up corner cases, to avoid division by zero or creation of negative | |
4446 | frequencies. */ | |
4447 | if (total_freq == 0) | |
4448 | total_freq = 1; | |
4449 | else if (entry_freq > total_freq) | |
4450 | entry_freq = total_freq; | |
4451 | } | |
5deaef19 | 4452 | |
b9a66240 ZD |
4453 | copy_bbs (region, n_region, region_copy, &exit, 1, &exit_copy, loop, |
4454 | split_edge_bb_loc (entry)); | |
09bac500 JH |
4455 | if (total_count) |
4456 | { | |
4457 | scale_bbs_frequencies_gcov_type (region, n_region, | |
4458 | total_count - entry_count, | |
4459 | total_count); | |
4460 | scale_bbs_frequencies_gcov_type (region_copy, n_region, entry_count, | |
4461 | total_count); | |
4462 | } | |
4463 | else | |
4464 | { | |
4465 | scale_bbs_frequencies_int (region, n_region, total_freq - entry_freq, | |
4466 | total_freq); | |
4467 | scale_bbs_frequencies_int (region_copy, n_region, entry_freq, total_freq); | |
4468 | } | |
42759f1e ZD |
4469 | |
4470 | if (copying_header) | |
4471 | { | |
4472 | loop->header = exit->dest; | |
4473 | loop->latch = exit->src; | |
4474 | } | |
4475 | ||
4476 | /* Redirect the entry and add the phi node arguments. */ | |
6580ee77 | 4477 | redirected = redirect_edge_and_branch (entry, get_bb_copy (entry->dest)); |
42759f1e | 4478 | gcc_assert (redirected != NULL); |
71882046 | 4479 | flush_pending_stmts (entry); |
42759f1e ZD |
4480 | |
4481 | /* Concerning updating of dominators: We must recount dominators | |
84d65814 DN |
4482 | for entry block and its copy. Anything that is outside of the |
4483 | region, but was dominated by something inside needs recounting as | |
4484 | well. */ | |
42759f1e | 4485 | set_immediate_dominator (CDI_DOMINATORS, entry->dest, entry->src); |
6580ee77 | 4486 | doms[n_doms++] = get_bb_original (entry->dest); |
42759f1e ZD |
4487 | iterate_fix_dominators (CDI_DOMINATORS, doms, n_doms); |
4488 | free (doms); | |
4489 | ||
84d65814 | 4490 | /* Add the other PHI node arguments. */ |
42759f1e ZD |
4491 | add_phi_args_after_copy (region_copy, n_region); |
4492 | ||
84d65814 DN |
4493 | /* Update the SSA web. */ |
4494 | update_ssa (TODO_update_ssa); | |
42759f1e ZD |
4495 | |
4496 | if (free_region_copy) | |
4497 | free (region_copy); | |
4498 | ||
6580ee77 | 4499 | free_original_copy_tables (); |
42759f1e ZD |
4500 | return true; |
4501 | } | |
6de9cd9a | 4502 | |
50674e96 DN |
4503 | /* |
4504 | DEF_VEC_P(basic_block); | |
4505 | DEF_VEC_ALLOC_P(basic_block,heap); | |
4506 | */ | |
4507 | ||
4508 | /* Add all the blocks dominated by ENTRY to the array BBS_P. Stop | |
4509 | adding blocks when the dominator traversal reaches EXIT. This | |
4510 | function silently assumes that ENTRY strictly dominates EXIT. */ | |
4511 | ||
4512 | static void | |
4513 | gather_blocks_in_sese_region (basic_block entry, basic_block exit, | |
4514 | VEC(basic_block,heap) **bbs_p) | |
4515 | { | |
4516 | basic_block son; | |
4517 | ||
4518 | for (son = first_dom_son (CDI_DOMINATORS, entry); | |
4519 | son; | |
4520 | son = next_dom_son (CDI_DOMINATORS, son)) | |
4521 | { | |
4522 | VEC_safe_push (basic_block, heap, *bbs_p, son); | |
4523 | if (son != exit) | |
4524 | gather_blocks_in_sese_region (son, exit, bbs_p); | |
4525 | } | |
4526 | } | |
4527 | ||
4528 | ||
4529 | struct move_stmt_d | |
4530 | { | |
4531 | tree block; | |
4532 | tree from_context; | |
4533 | tree to_context; | |
4534 | bitmap vars_to_remove; | |
fad41cd7 | 4535 | htab_t new_label_map; |
50674e96 DN |
4536 | bool remap_decls_p; |
4537 | }; | |
4538 | ||
4539 | /* Helper for move_block_to_fn. Set TREE_BLOCK in every expression | |
4540 | contained in *TP and change the DECL_CONTEXT of every local | |
4541 | variable referenced in *TP. */ | |
4542 | ||
4543 | static tree | |
fad41cd7 | 4544 | move_stmt_r (tree *tp, int *walk_subtrees, void *data) |
50674e96 DN |
4545 | { |
4546 | struct move_stmt_d *p = (struct move_stmt_d *) data; | |
fad41cd7 | 4547 | tree t = *tp; |
50674e96 | 4548 | |
fad41cd7 RH |
4549 | if (p->block && IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (TREE_CODE (t)))) |
4550 | TREE_BLOCK (t) = p->block; | |
50674e96 | 4551 | |
fad41cd7 | 4552 | if (OMP_DIRECTIVE_P (t) && TREE_CODE (t) != OMP_RETURN_EXPR) |
50674e96 DN |
4553 | { |
4554 | /* Do not remap variables inside OMP directives. Variables | |
4555 | referenced in clauses and directive header belong to the | |
4556 | parent function and should not be moved into the child | |
4557 | function. */ | |
fad41cd7 | 4558 | bool save_remap_decls_p = p->remap_decls_p; |
50674e96 | 4559 | p->remap_decls_p = false; |
fad41cd7 RH |
4560 | *walk_subtrees = 0; |
4561 | ||
4562 | walk_tree (&OMP_BODY (t), move_stmt_r, p, NULL); | |
50674e96 | 4563 | |
fad41cd7 RH |
4564 | p->remap_decls_p = save_remap_decls_p; |
4565 | } | |
4566 | else if (DECL_P (t) && DECL_CONTEXT (t) == p->from_context) | |
50674e96 | 4567 | { |
fad41cd7 RH |
4568 | if (TREE_CODE (t) == LABEL_DECL) |
4569 | { | |
4570 | if (p->new_label_map) | |
4571 | { | |
4572 | struct tree_map in, *out; | |
4573 | in.from = t; | |
4574 | out = htab_find_with_hash (p->new_label_map, &in, DECL_UID (t)); | |
4575 | if (out) | |
4576 | *tp = t = out->to; | |
4577 | } | |
50674e96 | 4578 | |
fad41cd7 RH |
4579 | DECL_CONTEXT (t) = p->to_context; |
4580 | } | |
4581 | else if (p->remap_decls_p) | |
50674e96 | 4582 | { |
fad41cd7 | 4583 | DECL_CONTEXT (t) = p->to_context; |
50674e96 | 4584 | |
fad41cd7 RH |
4585 | if (TREE_CODE (t) == VAR_DECL) |
4586 | { | |
4587 | struct function *f = DECL_STRUCT_FUNCTION (p->to_context); | |
4588 | f->unexpanded_var_list | |
4589 | = tree_cons (0, t, f->unexpanded_var_list); | |
4590 | ||
4591 | /* Mark T to be removed from the original function, | |
4592 | otherwise it will be given a DECL_RTL when the | |
4593 | original function is expanded. */ | |
4594 | bitmap_set_bit (p->vars_to_remove, DECL_UID (t)); | |
4595 | } | |
50674e96 DN |
4596 | } |
4597 | } | |
fad41cd7 RH |
4598 | else if (TYPE_P (t)) |
4599 | *walk_subtrees = 0; | |
50674e96 DN |
4600 | |
4601 | return NULL_TREE; | |
4602 | } | |
4603 | ||
4604 | ||
4605 | /* Move basic block BB from function CFUN to function DEST_FN. The | |
4606 | block is moved out of the original linked list and placed after | |
4607 | block AFTER in the new list. Also, the block is removed from the | |
4608 | original array of blocks and placed in DEST_FN's array of blocks. | |
4609 | If UPDATE_EDGE_COUNT_P is true, the edge counts on both CFGs is | |
4610 | updated to reflect the moved edges. | |
4611 | ||
4612 | On exit, local variables that need to be removed from | |
4613 | CFUN->UNEXPANDED_VAR_LIST will have been added to VARS_TO_REMOVE. */ | |
4614 | ||
4615 | static void | |
4616 | move_block_to_fn (struct function *dest_cfun, basic_block bb, | |
4617 | basic_block after, bool update_edge_count_p, | |
fad41cd7 | 4618 | bitmap vars_to_remove, htab_t new_label_map, int eh_offset) |
50674e96 DN |
4619 | { |
4620 | struct control_flow_graph *cfg; | |
4621 | edge_iterator ei; | |
4622 | edge e; | |
4623 | block_stmt_iterator si; | |
4624 | struct move_stmt_d d; | |
728b26bb DN |
4625 | unsigned old_len, new_len; |
4626 | basic_block *addr; | |
50674e96 DN |
4627 | |
4628 | /* Link BB to the new linked list. */ | |
4629 | move_block_after (bb, after); | |
4630 | ||
4631 | /* Update the edge count in the corresponding flowgraphs. */ | |
4632 | if (update_edge_count_p) | |
4633 | FOR_EACH_EDGE (e, ei, bb->succs) | |
4634 | { | |
4635 | cfun->cfg->x_n_edges--; | |
4636 | dest_cfun->cfg->x_n_edges++; | |
4637 | } | |
4638 | ||
4639 | /* Remove BB from the original basic block array. */ | |
4640 | VEC_replace (basic_block, cfun->cfg->x_basic_block_info, bb->index, NULL); | |
4641 | cfun->cfg->x_n_basic_blocks--; | |
4642 | ||
4643 | /* Grow DEST_CFUN's basic block array if needed. */ | |
4644 | cfg = dest_cfun->cfg; | |
4645 | cfg->x_n_basic_blocks++; | |
4646 | if (bb->index > cfg->x_last_basic_block) | |
4647 | cfg->x_last_basic_block = bb->index; | |
4648 | ||
728b26bb DN |
4649 | old_len = VEC_length (basic_block, cfg->x_basic_block_info); |
4650 | if ((unsigned) cfg->x_last_basic_block >= old_len) | |
50674e96 | 4651 | { |
728b26bb DN |
4652 | new_len = cfg->x_last_basic_block + (cfg->x_last_basic_block + 3) / 4; |
4653 | VEC_safe_grow (basic_block, gc, cfg->x_basic_block_info, new_len); | |
4654 | addr = VEC_address (basic_block, cfg->x_basic_block_info); | |
4655 | memset (&addr[old_len], 0, sizeof (basic_block) * (new_len - old_len)); | |
50674e96 DN |
4656 | } |
4657 | ||
4658 | VEC_replace (basic_block, cfg->x_basic_block_info, | |
4659 | cfg->x_last_basic_block, bb); | |
4660 | ||
4661 | /* The statements in BB need to be associated with a new TREE_BLOCK. | |
4662 | Labels need to be associated with a new label-to-block map. */ | |
4663 | memset (&d, 0, sizeof (d)); | |
4664 | d.vars_to_remove = vars_to_remove; | |
4665 | ||
4666 | for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si)) | |
4667 | { | |
4668 | tree stmt = bsi_stmt (si); | |
fad41cd7 | 4669 | int region; |
50674e96 DN |
4670 | |
4671 | d.from_context = cfun->decl; | |
4672 | d.to_context = dest_cfun->decl; | |
4673 | d.remap_decls_p = true; | |
fad41cd7 | 4674 | d.new_label_map = new_label_map; |
50674e96 DN |
4675 | if (TREE_BLOCK (stmt)) |
4676 | d.block = DECL_INITIAL (dest_cfun->decl); | |
4677 | ||
4678 | walk_tree (&stmt, move_stmt_r, &d, NULL); | |
4679 | ||
4680 | if (TREE_CODE (stmt) == LABEL_EXPR) | |
4681 | { | |
50674e96 DN |
4682 | tree label = LABEL_EXPR_LABEL (stmt); |
4683 | int uid = LABEL_DECL_UID (label); | |
4684 | ||
4685 | gcc_assert (uid > -1); | |
4686 | ||
4687 | old_len = VEC_length (basic_block, cfg->x_label_to_block_map); | |
4688 | if (old_len <= (unsigned) uid) | |
4689 | { | |
728b26bb | 4690 | new_len = 3 * uid / 2; |
50674e96 DN |
4691 | VEC_safe_grow (basic_block, gc, cfg->x_label_to_block_map, |
4692 | new_len); | |
4693 | addr = VEC_address (basic_block, cfg->x_label_to_block_map); | |
4694 | memset (&addr[old_len], 0, | |
4695 | sizeof (basic_block) * (new_len - old_len)); | |
4696 | } | |
4697 | ||
4698 | VEC_replace (basic_block, cfg->x_label_to_block_map, uid, bb); | |
4699 | VEC_replace (basic_block, cfun->cfg->x_label_to_block_map, uid, NULL); | |
4700 | ||
4701 | gcc_assert (DECL_CONTEXT (label) == dest_cfun->decl); | |
4702 | ||
4703 | if (uid >= dest_cfun->last_label_uid) | |
4704 | dest_cfun->last_label_uid = uid + 1; | |
4705 | } | |
fad41cd7 RH |
4706 | else if (TREE_CODE (stmt) == RESX_EXPR && eh_offset != 0) |
4707 | TREE_OPERAND (stmt, 0) = | |
4708 | build_int_cst (NULL_TREE, | |
4709 | TREE_INT_CST_LOW (TREE_OPERAND (stmt, 0)) | |
4710 | + eh_offset); | |
4711 | ||
4712 | region = lookup_stmt_eh_region (stmt); | |
4713 | if (region >= 0) | |
4714 | { | |
4715 | add_stmt_to_eh_region_fn (dest_cfun, stmt, region + eh_offset); | |
4716 | remove_stmt_from_eh_region (stmt); | |
4717 | } | |
4718 | } | |
4719 | } | |
4720 | ||
4721 | /* Examine the statements in BB (which is in SRC_CFUN); find and return | |
4722 | the outermost EH region. Use REGION as the incoming base EH region. */ | |
4723 | ||
4724 | static int | |
4725 | find_outermost_region_in_block (struct function *src_cfun, | |
4726 | basic_block bb, int region) | |
4727 | { | |
4728 | block_stmt_iterator si; | |
4729 | ||
4730 | for (si = bsi_start (bb); !bsi_end_p (si); bsi_next (&si)) | |
4731 | { | |
4732 | tree stmt = bsi_stmt (si); | |
4733 | int stmt_region; | |
1799e5d5 | 4734 | |
fad41cd7 RH |
4735 | stmt_region = lookup_stmt_eh_region_fn (src_cfun, stmt); |
4736 | if (stmt_region > 0 | |
4737 | && (region < 0 || eh_region_outer_p (src_cfun, stmt_region, region))) | |
4738 | region = stmt_region; | |
50674e96 | 4739 | } |
fad41cd7 RH |
4740 | |
4741 | return region; | |
50674e96 DN |
4742 | } |
4743 | ||
fad41cd7 RH |
4744 | static tree |
4745 | new_label_mapper (tree decl, void *data) | |
4746 | { | |
4747 | htab_t hash = (htab_t) data; | |
4748 | struct tree_map *m; | |
4749 | void **slot; | |
4750 | ||
4751 | gcc_assert (TREE_CODE (decl) == LABEL_DECL); | |
4752 | ||
4753 | m = xmalloc (sizeof (struct tree_map)); | |
4754 | m->hash = DECL_UID (decl); | |
4755 | m->from = decl; | |
4756 | m->to = create_artificial_label (); | |
4757 | LABEL_DECL_UID (m->to) = LABEL_DECL_UID (decl); | |
4758 | ||
4759 | slot = htab_find_slot_with_hash (hash, m, m->hash, INSERT); | |
4760 | gcc_assert (*slot == NULL); | |
4761 | ||
4762 | *slot = m; | |
4763 | ||
4764 | return m->to; | |
4765 | } | |
50674e96 DN |
4766 | |
4767 | /* Move a single-entry, single-exit region delimited by ENTRY_BB and | |
4768 | EXIT_BB to function DEST_CFUN. The whole region is replaced by a | |
4769 | single basic block in the original CFG and the new basic block is | |
4770 | returned. DEST_CFUN must not have a CFG yet. | |
4771 | ||
4772 | Note that the region need not be a pure SESE region. Blocks inside | |
4773 | the region may contain calls to abort/exit. The only restriction | |
4774 | is that ENTRY_BB should be the only entry point and it must | |
4775 | dominate EXIT_BB. | |
4776 | ||
4777 | All local variables referenced in the region are assumed to be in | |
4778 | the corresponding BLOCK_VARS and unexpanded variable lists | |
4779 | associated with DEST_CFUN. */ | |
4780 | ||
4781 | basic_block | |
4782 | move_sese_region_to_fn (struct function *dest_cfun, basic_block entry_bb, | |
4783 | basic_block exit_bb) | |
4784 | { | |
4785 | VEC(basic_block,heap) *bbs; | |
4786 | basic_block after, bb, *entry_pred, *exit_succ; | |
4787 | struct function *saved_cfun; | |
fad41cd7 | 4788 | int *entry_flag, *exit_flag, eh_offset; |
50674e96 DN |
4789 | unsigned i, num_entry_edges, num_exit_edges; |
4790 | edge e; | |
4791 | edge_iterator ei; | |
4792 | bitmap vars_to_remove; | |
fad41cd7 | 4793 | htab_t new_label_map; |
50674e96 DN |
4794 | |
4795 | saved_cfun = cfun; | |
4796 | ||
4797 | /* Collect all the blocks in the region. Manually add ENTRY_BB | |
4798 | because it won't be added by dfs_enumerate_from. */ | |
4799 | calculate_dominance_info (CDI_DOMINATORS); | |
4800 | ||
4801 | /* If ENTRY does not strictly dominate EXIT, this cannot be an SESE | |
4802 | region. */ | |
4803 | gcc_assert (entry_bb != exit_bb | |
4804 | && dominated_by_p (CDI_DOMINATORS, exit_bb, entry_bb)); | |
4805 | ||
4806 | bbs = NULL; | |
4807 | VEC_safe_push (basic_block, heap, bbs, entry_bb); | |
4808 | gather_blocks_in_sese_region (entry_bb, exit_bb, &bbs); | |
4809 | ||
4810 | /* Detach ENTRY_BB and EXIT_BB from CFUN->CFG. We need to remember | |
4811 | the predecessor edges to ENTRY_BB and the successor edges to | |
4812 | EXIT_BB so that we can re-attach them to the new basic block that | |
4813 | will replace the region. */ | |
4814 | num_entry_edges = EDGE_COUNT (entry_bb->preds); | |
4815 | entry_pred = (basic_block *) xcalloc (num_entry_edges, sizeof (basic_block)); | |
4816 | entry_flag = (int *) xcalloc (num_entry_edges, sizeof (int)); | |
4817 | i = 0; | |
4818 | for (ei = ei_start (entry_bb->preds); (e = ei_safe_edge (ei)) != NULL;) | |
4819 | { | |
4820 | entry_flag[i] = e->flags; | |
4821 | entry_pred[i++] = e->src; | |
4822 | remove_edge (e); | |
4823 | } | |
4824 | ||
4825 | num_exit_edges = EDGE_COUNT (exit_bb->succs); | |
4826 | exit_succ = (basic_block *) xcalloc (num_exit_edges, sizeof (basic_block)); | |
4827 | exit_flag = (int *) xcalloc (num_exit_edges, sizeof (int)); | |
4828 | i = 0; | |
4829 | for (ei = ei_start (exit_bb->succs); (e = ei_safe_edge (ei)) != NULL;) | |
4830 | { | |
4831 | exit_flag[i] = e->flags; | |
4832 | exit_succ[i++] = e->dest; | |
4833 | remove_edge (e); | |
4834 | } | |
4835 | ||
4836 | /* Switch context to the child function to initialize DEST_FN's CFG. */ | |
4837 | gcc_assert (dest_cfun->cfg == NULL); | |
4838 | cfun = dest_cfun; | |
fad41cd7 | 4839 | |
50674e96 | 4840 | init_empty_tree_cfg (); |
fad41cd7 RH |
4841 | |
4842 | /* Initialize EH information for the new function. */ | |
4843 | eh_offset = 0; | |
4844 | new_label_map = NULL; | |
4845 | if (saved_cfun->eh) | |
4846 | { | |
4847 | int region = -1; | |
4848 | ||
4849 | for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++) | |
4850 | region = find_outermost_region_in_block (saved_cfun, bb, region); | |
4851 | ||
4852 | init_eh_for_function (); | |
4853 | if (region != -1) | |
4854 | { | |
4855 | new_label_map = htab_create (17, tree_map_hash, tree_map_eq, free); | |
4856 | eh_offset = duplicate_eh_regions (saved_cfun, new_label_mapper, | |
4857 | new_label_map, region, 0); | |
4858 | } | |
4859 | } | |
4860 | ||
50674e96 DN |
4861 | cfun = saved_cfun; |
4862 | ||
4863 | /* Move blocks from BBS into DEST_CFUN. */ | |
4864 | gcc_assert (VEC_length (basic_block, bbs) >= 2); | |
4865 | after = dest_cfun->cfg->x_entry_block_ptr; | |
4866 | vars_to_remove = BITMAP_ALLOC (NULL); | |
4867 | for (i = 0; VEC_iterate (basic_block, bbs, i, bb); i++) | |
4868 | { | |
4869 | /* No need to update edge counts on the last block. It has | |
4870 | already been updated earlier when we detached the region from | |
4871 | the original CFG. */ | |
fad41cd7 RH |
4872 | move_block_to_fn (dest_cfun, bb, after, bb != exit_bb, vars_to_remove, |
4873 | new_label_map, eh_offset); | |
50674e96 DN |
4874 | after = bb; |
4875 | } | |
4876 | ||
fad41cd7 RH |
4877 | if (new_label_map) |
4878 | htab_delete (new_label_map); | |
4879 | ||
50674e96 DN |
4880 | /* Remove the variables marked in VARS_TO_REMOVE from |
4881 | CFUN->UNEXPANDED_VAR_LIST. Otherwise, they will be given a | |
4882 | DECL_RTL in the context of CFUN. */ | |
4883 | if (!bitmap_empty_p (vars_to_remove)) | |
4884 | { | |
4885 | tree *p; | |
4886 | ||
4887 | for (p = &cfun->unexpanded_var_list; *p; ) | |
4888 | { | |
4889 | tree var = TREE_VALUE (*p); | |
4890 | if (bitmap_bit_p (vars_to_remove, DECL_UID (var))) | |
4891 | { | |
4892 | *p = TREE_CHAIN (*p); | |
4893 | continue; | |
4894 | } | |
4895 | ||
4896 | p = &TREE_CHAIN (*p); | |
4897 | } | |
4898 | } | |
4899 | ||
4900 | BITMAP_FREE (vars_to_remove); | |
4901 | ||
4902 | /* Rewire the entry and exit blocks. The successor to the entry | |
4903 | block turns into the successor of DEST_FN's ENTRY_BLOCK_PTR in | |
4904 | the child function. Similarly, the predecessor of DEST_FN's | |
4905 | EXIT_BLOCK_PTR turns into the predecessor of EXIT_BLOCK_PTR. We | |
4906 | need to switch CFUN between DEST_CFUN and SAVED_CFUN so that the | |
4907 | various CFG manipulation function get to the right CFG. | |
4908 | ||
4909 | FIXME, this is silly. The CFG ought to become a parameter to | |
4910 | these helpers. */ | |
4911 | cfun = dest_cfun; | |
4912 | make_edge (ENTRY_BLOCK_PTR, entry_bb, EDGE_FALLTHRU); | |
4913 | make_edge (exit_bb, EXIT_BLOCK_PTR, 0); | |
4914 | cfun = saved_cfun; | |
4915 | ||
4916 | /* Back in the original function, the SESE region has disappeared, | |
4917 | create a new basic block in its place. */ | |
4918 | bb = create_empty_bb (entry_pred[0]); | |
4919 | for (i = 0; i < num_entry_edges; i++) | |
4920 | make_edge (entry_pred[i], bb, entry_flag[i]); | |
4921 | ||
4922 | for (i = 0; i < num_exit_edges; i++) | |
4923 | make_edge (bb, exit_succ[i], exit_flag[i]); | |
4924 | ||
4925 | free (exit_flag); | |
4926 | free (entry_flag); | |
4927 | free (entry_pred); | |
4928 | free (exit_succ); | |
4929 | free_dominance_info (CDI_DOMINATORS); | |
4930 | free_dominance_info (CDI_POST_DOMINATORS); | |
4931 | VEC_free (basic_block, heap, bbs); | |
4932 | ||
4933 | return bb; | |
4934 | } | |
4935 | ||
84d65814 | 4936 | |
6de9cd9a DN |
4937 | /* Dump FUNCTION_DECL FN to file FILE using FLAGS (see TDF_* in tree.h) */ |
4938 | ||
4939 | void | |
4940 | dump_function_to_file (tree fn, FILE *file, int flags) | |
4941 | { | |
4942 | tree arg, vars, var; | |
4943 | bool ignore_topmost_bind = false, any_var = false; | |
4944 | basic_block bb; | |
4945 | tree chain; | |
953ff289 DN |
4946 | struct function *saved_cfun; |
4947 | ||
673fda6b | 4948 | fprintf (file, "%s (", lang_hooks.decl_printable_name (fn, 2)); |
6de9cd9a DN |
4949 | |
4950 | arg = DECL_ARGUMENTS (fn); | |
4951 | while (arg) | |
4952 | { | |
4953 | print_generic_expr (file, arg, dump_flags); | |
4954 | if (TREE_CHAIN (arg)) | |
4955 | fprintf (file, ", "); | |
4956 | arg = TREE_CHAIN (arg); | |
4957 | } | |
4958 | fprintf (file, ")\n"); | |
4959 | ||
cc7220fd JH |
4960 | if (flags & TDF_DETAILS) |
4961 | dump_eh_tree (file, DECL_STRUCT_FUNCTION (fn)); | |
6de9cd9a DN |
4962 | if (flags & TDF_RAW) |
4963 | { | |
4964 | dump_node (fn, TDF_SLIM | flags, file); | |
4965 | return; | |
4966 | } | |
4967 | ||
953ff289 DN |
4968 | /* Switch CFUN to point to FN. */ |
4969 | saved_cfun = cfun; | |
4970 | cfun = DECL_STRUCT_FUNCTION (fn); | |
4971 | ||
6de9cd9a DN |
4972 | /* When GIMPLE is lowered, the variables are no longer available in |
4973 | BIND_EXPRs, so display them separately. */ | |
32a87d45 | 4974 | if (cfun && cfun->decl == fn && cfun->unexpanded_var_list) |
6de9cd9a DN |
4975 | { |
4976 | ignore_topmost_bind = true; | |
4977 | ||
4978 | fprintf (file, "{\n"); | |
4979 | for (vars = cfun->unexpanded_var_list; vars; vars = TREE_CHAIN (vars)) | |
4980 | { | |
4981 | var = TREE_VALUE (vars); | |
4982 | ||
4983 | print_generic_decl (file, var, flags); | |
4984 | fprintf (file, "\n"); | |
4985 | ||
4986 | any_var = true; | |
4987 | } | |
4988 | } | |
4989 | ||
32a87d45 | 4990 | if (cfun && cfun->decl == fn && cfun->cfg && basic_block_info) |
6de9cd9a DN |
4991 | { |
4992 | /* Make a CFG based dump. */ | |
878f99d2 | 4993 | check_bb_profile (ENTRY_BLOCK_PTR, file); |
6de9cd9a DN |
4994 | if (!ignore_topmost_bind) |
4995 | fprintf (file, "{\n"); | |
4996 | ||
4997 | if (any_var && n_basic_blocks) | |
4998 | fprintf (file, "\n"); | |
4999 | ||
5000 | FOR_EACH_BB (bb) | |
5001 | dump_generic_bb (file, bb, 2, flags); | |
5002 | ||
5003 | fprintf (file, "}\n"); | |
878f99d2 | 5004 | check_bb_profile (EXIT_BLOCK_PTR, file); |
6de9cd9a DN |
5005 | } |
5006 | else | |
5007 | { | |
5008 | int indent; | |
5009 | ||
5010 | /* Make a tree based dump. */ | |
5011 | chain = DECL_SAVED_TREE (fn); | |
5012 | ||
953ff289 | 5013 | if (chain && TREE_CODE (chain) == BIND_EXPR) |
6de9cd9a DN |
5014 | { |
5015 | if (ignore_topmost_bind) | |
5016 | { | |
5017 | chain = BIND_EXPR_BODY (chain); | |
5018 | indent = 2; | |
5019 | } | |
5020 | else | |
5021 | indent = 0; | |
5022 | } | |
5023 | else | |
5024 | { | |
5025 | if (!ignore_topmost_bind) | |
5026 | fprintf (file, "{\n"); | |
5027 | indent = 2; | |
5028 | } | |
5029 | ||
5030 | if (any_var) | |
5031 | fprintf (file, "\n"); | |
5032 | ||
5033 | print_generic_stmt_indented (file, chain, flags, indent); | |
5034 | if (ignore_topmost_bind) | |
5035 | fprintf (file, "}\n"); | |
5036 | } | |
5037 | ||
5038 | fprintf (file, "\n\n"); | |
953ff289 DN |
5039 | |
5040 | /* Restore CFUN. */ | |
5041 | cfun = saved_cfun; | |
5042 | } | |
5043 | ||
5044 | ||
5045 | /* Dump FUNCTION_DECL FN to stderr using FLAGS (see TDF_* in tree.h) */ | |
5046 | ||
5047 | void | |
5048 | debug_function (tree fn, int flags) | |
5049 | { | |
5050 | dump_function_to_file (fn, stderr, flags); | |
6de9cd9a DN |
5051 | } |
5052 | ||
5053 | ||
5054 | /* Pretty print of the loops intermediate representation. */ | |
5055 | static void print_loop (FILE *, struct loop *, int); | |
628f6a4e BE |
5056 | static void print_pred_bbs (FILE *, basic_block bb); |
5057 | static void print_succ_bbs (FILE *, basic_block bb); | |
6de9cd9a DN |
5058 | |
5059 | ||
d7770457 | 5060 | /* Print on FILE the indexes for the predecessors of basic_block BB. */ |
6de9cd9a DN |
5061 | |
5062 | static void | |
628f6a4e | 5063 | print_pred_bbs (FILE *file, basic_block bb) |
6de9cd9a | 5064 | { |
628f6a4e BE |
5065 | edge e; |
5066 | edge_iterator ei; | |
5067 | ||
5068 | FOR_EACH_EDGE (e, ei, bb->preds) | |
d7770457 | 5069 | fprintf (file, "bb_%d ", e->src->index); |
6de9cd9a DN |
5070 | } |
5071 | ||
5072 | ||
d7770457 | 5073 | /* Print on FILE the indexes for the successors of basic_block BB. */ |
6de9cd9a DN |
5074 | |
5075 | static void | |
628f6a4e | 5076 | print_succ_bbs (FILE *file, basic_block bb) |
6de9cd9a | 5077 | { |
628f6a4e BE |
5078 | edge e; |
5079 | edge_iterator ei; | |
5080 | ||
5081 | FOR_EACH_EDGE (e, ei, bb->succs) | |
d7770457 | 5082 | fprintf (file, "bb_%d ", e->dest->index); |
6de9cd9a DN |
5083 | } |
5084 | ||
5085 | ||
5086 | /* Pretty print LOOP on FILE, indented INDENT spaces. */ | |
5087 | ||
5088 | static void | |
5089 | print_loop (FILE *file, struct loop *loop, int indent) | |
5090 | { | |
5091 | char *s_indent; | |
5092 | basic_block bb; | |
5093 | ||
5094 | if (loop == NULL) | |
5095 | return; | |
5096 | ||
5097 | s_indent = (char *) alloca ((size_t) indent + 1); | |
5098 | memset ((void *) s_indent, ' ', (size_t) indent); | |
5099 | s_indent[indent] = '\0'; | |
5100 | ||
5101 | /* Print the loop's header. */ | |
5102 | fprintf (file, "%sloop_%d\n", s_indent, loop->num); | |
5103 | ||
5104 | /* Print the loop's body. */ | |
5105 | fprintf (file, "%s{\n", s_indent); | |
5106 | FOR_EACH_BB (bb) | |
5107 | if (bb->loop_father == loop) | |
5108 | { | |
5109 | /* Print the basic_block's header. */ | |
5110 | fprintf (file, "%s bb_%d (preds = {", s_indent, bb->index); | |
628f6a4e | 5111 | print_pred_bbs (file, bb); |
6de9cd9a | 5112 | fprintf (file, "}, succs = {"); |
628f6a4e | 5113 | print_succ_bbs (file, bb); |
6de9cd9a DN |
5114 | fprintf (file, "})\n"); |
5115 | ||
5116 | /* Print the basic_block's body. */ | |
5117 | fprintf (file, "%s {\n", s_indent); | |
5118 | tree_dump_bb (bb, file, indent + 4); | |
5119 | fprintf (file, "%s }\n", s_indent); | |
5120 | } | |
5121 | ||
5122 | print_loop (file, loop->inner, indent + 2); | |
5123 | fprintf (file, "%s}\n", s_indent); | |
5124 | print_loop (file, loop->next, indent); | |
5125 | } | |
5126 | ||
5127 | ||
5128 | /* Follow a CFG edge from the entry point of the program, and on entry | |
5129 | of a loop, pretty print the loop structure on FILE. */ | |
5130 | ||
5131 | void | |
5132 | print_loop_ir (FILE *file) | |
5133 | { | |
5134 | basic_block bb; | |
5135 | ||
24bd1a0b | 5136 | bb = BASIC_BLOCK (NUM_FIXED_BLOCKS); |
6de9cd9a DN |
5137 | if (bb && bb->loop_father) |
5138 | print_loop (file, bb->loop_father, 0); | |
5139 | } | |
5140 | ||
5141 | ||
5142 | /* Debugging loops structure at tree level. */ | |
5143 | ||
5144 | void | |
5145 | debug_loop_ir (void) | |
5146 | { | |
5147 | print_loop_ir (stderr); | |
5148 | } | |
5149 | ||
5150 | ||
5151 | /* Return true if BB ends with a call, possibly followed by some | |
5152 | instructions that must stay with the call. Return false, | |
5153 | otherwise. */ | |
5154 | ||
5155 | static bool | |
5156 | tree_block_ends_with_call_p (basic_block bb) | |
5157 | { | |
5158 | block_stmt_iterator bsi = bsi_last (bb); | |
cd709752 | 5159 | return get_call_expr_in (bsi_stmt (bsi)) != NULL; |
6de9cd9a DN |
5160 | } |
5161 | ||
5162 | ||
5163 | /* Return true if BB ends with a conditional branch. Return false, | |
5164 | otherwise. */ | |
5165 | ||
5166 | static bool | |
5167 | tree_block_ends_with_condjump_p (basic_block bb) | |
5168 | { | |
9885da8e ZD |
5169 | tree stmt = last_stmt (bb); |
5170 | return (stmt && TREE_CODE (stmt) == COND_EXPR); | |
6de9cd9a DN |
5171 | } |
5172 | ||
5173 | ||
5174 | /* Return true if we need to add fake edge to exit at statement T. | |
5175 | Helper function for tree_flow_call_edges_add. */ | |
5176 | ||
5177 | static bool | |
5178 | need_fake_edge_p (tree t) | |
5179 | { | |
cd709752 | 5180 | tree call; |
6de9cd9a DN |
5181 | |
5182 | /* NORETURN and LONGJMP calls already have an edge to exit. | |
321cf1f2 | 5183 | CONST and PURE calls do not need one. |
6de9cd9a DN |
5184 | We don't currently check for CONST and PURE here, although |
5185 | it would be a good idea, because those attributes are | |
5186 | figured out from the RTL in mark_constant_function, and | |
5187 | the counter incrementation code from -fprofile-arcs | |
5188 | leads to different results from -fbranch-probabilities. */ | |
cd709752 RH |
5189 | call = get_call_expr_in (t); |
5190 | if (call | |
321cf1f2 | 5191 | && !(call_expr_flags (call) & ECF_NORETURN)) |
6de9cd9a DN |
5192 | return true; |
5193 | ||
5194 | if (TREE_CODE (t) == ASM_EXPR | |
5195 | && (ASM_VOLATILE_P (t) || ASM_INPUT_P (t))) | |
5196 | return true; | |
5197 | ||
5198 | return false; | |
5199 | } | |
5200 | ||
5201 | ||
5202 | /* Add fake edges to the function exit for any non constant and non | |
5203 | noreturn calls, volatile inline assembly in the bitmap of blocks | |
5204 | specified by BLOCKS or to the whole CFG if BLOCKS is zero. Return | |
5205 | the number of blocks that were split. | |
5206 | ||
5207 | The goal is to expose cases in which entering a basic block does | |
5208 | not imply that all subsequent instructions must be executed. */ | |
5209 | ||
5210 | static int | |
5211 | tree_flow_call_edges_add (sbitmap blocks) | |
5212 | { | |
5213 | int i; | |
5214 | int blocks_split = 0; | |
5215 | int last_bb = last_basic_block; | |
5216 | bool check_last_block = false; | |
5217 | ||
24bd1a0b | 5218 | if (n_basic_blocks == NUM_FIXED_BLOCKS) |
6de9cd9a DN |
5219 | return 0; |
5220 | ||
5221 | if (! blocks) | |
5222 | check_last_block = true; | |
5223 | else | |
5224 | check_last_block = TEST_BIT (blocks, EXIT_BLOCK_PTR->prev_bb->index); | |
5225 | ||
5226 | /* In the last basic block, before epilogue generation, there will be | |
5227 | a fallthru edge to EXIT. Special care is required if the last insn | |
5228 | of the last basic block is a call because make_edge folds duplicate | |
5229 | edges, which would result in the fallthru edge also being marked | |
5230 | fake, which would result in the fallthru edge being removed by | |
5231 | remove_fake_edges, which would result in an invalid CFG. | |
5232 | ||
5233 | Moreover, we can't elide the outgoing fake edge, since the block | |
5234 | profiler needs to take this into account in order to solve the minimal | |
5235 | spanning tree in the case that the call doesn't return. | |
5236 | ||
5237 | Handle this by adding a dummy instruction in a new last basic block. */ | |
5238 | if (check_last_block) | |
5239 | { | |
5240 | basic_block bb = EXIT_BLOCK_PTR->prev_bb; | |
5241 | block_stmt_iterator bsi = bsi_last (bb); | |
5242 | tree t = NULL_TREE; | |
5243 | if (!bsi_end_p (bsi)) | |
5244 | t = bsi_stmt (bsi); | |
5245 | ||
6a60530d | 5246 | if (t && need_fake_edge_p (t)) |
6de9cd9a DN |
5247 | { |
5248 | edge e; | |
5249 | ||
9ff3d2de JL |
5250 | e = find_edge (bb, EXIT_BLOCK_PTR); |
5251 | if (e) | |
5252 | { | |
5253 | bsi_insert_on_edge (e, build_empty_stmt ()); | |
5254 | bsi_commit_edge_inserts (); | |
5255 | } | |
6de9cd9a DN |
5256 | } |
5257 | } | |
5258 | ||
5259 | /* Now add fake edges to the function exit for any non constant | |
5260 | calls since there is no way that we can determine if they will | |
5261 | return or not... */ | |
5262 | for (i = 0; i < last_bb; i++) | |
5263 | { | |
5264 | basic_block bb = BASIC_BLOCK (i); | |
5265 | block_stmt_iterator bsi; | |
5266 | tree stmt, last_stmt; | |
5267 | ||
5268 | if (!bb) | |
5269 | continue; | |
5270 | ||
5271 | if (blocks && !TEST_BIT (blocks, i)) | |
5272 | continue; | |
5273 | ||
5274 | bsi = bsi_last (bb); | |
5275 | if (!bsi_end_p (bsi)) | |
5276 | { | |
5277 | last_stmt = bsi_stmt (bsi); | |
5278 | do | |
5279 | { | |
5280 | stmt = bsi_stmt (bsi); | |
5281 | if (need_fake_edge_p (stmt)) | |
5282 | { | |
5283 | edge e; | |
5284 | /* The handling above of the final block before the | |
5285 | epilogue should be enough to verify that there is | |
5286 | no edge to the exit block in CFG already. | |
5287 | Calling make_edge in such case would cause us to | |
5288 | mark that edge as fake and remove it later. */ | |
5289 | #ifdef ENABLE_CHECKING | |
5290 | if (stmt == last_stmt) | |
628f6a4e | 5291 | { |
9ff3d2de JL |
5292 | e = find_edge (bb, EXIT_BLOCK_PTR); |
5293 | gcc_assert (e == NULL); | |
628f6a4e | 5294 | } |
6de9cd9a DN |
5295 | #endif |
5296 | ||
5297 | /* Note that the following may create a new basic block | |
5298 | and renumber the existing basic blocks. */ | |
5299 | if (stmt != last_stmt) | |
5300 | { | |
5301 | e = split_block (bb, stmt); | |
5302 | if (e) | |
5303 | blocks_split++; | |
5304 | } | |
5305 | make_edge (bb, EXIT_BLOCK_PTR, EDGE_FAKE); | |
5306 | } | |
5307 | bsi_prev (&bsi); | |
5308 | } | |
5309 | while (!bsi_end_p (bsi)); | |
5310 | } | |
5311 | } | |
5312 | ||
5313 | if (blocks_split) | |
5314 | verify_flow_info (); | |
5315 | ||
5316 | return blocks_split; | |
5317 | } | |
5318 | ||
1eaba2f2 RH |
5319 | bool |
5320 | tree_purge_dead_eh_edges (basic_block bb) | |
5321 | { | |
5322 | bool changed = false; | |
628f6a4e BE |
5323 | edge e; |
5324 | edge_iterator ei; | |
1eaba2f2 RH |
5325 | tree stmt = last_stmt (bb); |
5326 | ||
5327 | if (stmt && tree_can_throw_internal (stmt)) | |
5328 | return false; | |
5329 | ||
628f6a4e | 5330 | for (ei = ei_start (bb->succs); (e = ei_safe_edge (ei)); ) |
1eaba2f2 | 5331 | { |
1eaba2f2 RH |
5332 | if (e->flags & EDGE_EH) |
5333 | { | |
d0d2cc21 | 5334 | remove_edge (e); |
1eaba2f2 RH |
5335 | changed = true; |
5336 | } | |
628f6a4e BE |
5337 | else |
5338 | ei_next (&ei); | |
1eaba2f2 RH |
5339 | } |
5340 | ||
69d49802 JJ |
5341 | /* Removal of dead EH edges might change dominators of not |
5342 | just immediate successors. E.g. when bb1 is changed so that | |
5343 | it no longer can throw and bb1->bb3 and bb1->bb4 are dead | |
5344 | eh edges purged by this function in: | |
5345 | 0 | |
5346 | / \ | |
5347 | v v | |
5348 | 1-->2 | |
5349 | / \ | | |
5350 | v v | | |
5351 | 3-->4 | | |
5352 | \ v | |
5353 | --->5 | |
5354 | | | |
5355 | - | |
5356 | idom(bb5) must be recomputed. For now just free the dominance | |
5357 | info. */ | |
5358 | if (changed) | |
5359 | free_dominance_info (CDI_DOMINATORS); | |
5360 | ||
1eaba2f2 RH |
5361 | return changed; |
5362 | } | |
5363 | ||
5364 | bool | |
5365 | tree_purge_all_dead_eh_edges (bitmap blocks) | |
5366 | { | |
5367 | bool changed = false; | |
3cd8c58a | 5368 | unsigned i; |
87c476a2 | 5369 | bitmap_iterator bi; |
1eaba2f2 | 5370 | |
87c476a2 ZD |
5371 | EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi) |
5372 | { | |
5373 | changed |= tree_purge_dead_eh_edges (BASIC_BLOCK (i)); | |
5374 | } | |
1eaba2f2 RH |
5375 | |
5376 | return changed; | |
5377 | } | |
6de9cd9a | 5378 | |
a100ac1e KH |
5379 | /* This function is called whenever a new edge is created or |
5380 | redirected. */ | |
5381 | ||
5382 | static void | |
5383 | tree_execute_on_growing_pred (edge e) | |
5384 | { | |
5385 | basic_block bb = e->dest; | |
5386 | ||
5387 | if (phi_nodes (bb)) | |
5388 | reserve_phi_args_for_new_edge (bb); | |
5389 | } | |
5390 | ||
e51546f8 KH |
5391 | /* This function is called immediately before edge E is removed from |
5392 | the edge vector E->dest->preds. */ | |
5393 | ||
5394 | static void | |
5395 | tree_execute_on_shrinking_pred (edge e) | |
5396 | { | |
5397 | if (phi_nodes (e->dest)) | |
5398 | remove_phi_args (e); | |
5399 | } | |
5400 | ||
1cb7dfc3 MH |
5401 | /*--------------------------------------------------------------------------- |
5402 | Helper functions for Loop versioning | |
5403 | ---------------------------------------------------------------------------*/ | |
5404 | ||
5405 | /* Adjust phi nodes for 'first' basic block. 'second' basic block is a copy | |
5406 | of 'first'. Both of them are dominated by 'new_head' basic block. When | |
5407 | 'new_head' was created by 'second's incoming edge it received phi arguments | |
5408 | on the edge by split_edge(). Later, additional edge 'e' was created to | |
5409 | connect 'new_head' and 'first'. Now this routine adds phi args on this | |
5410 | additional edge 'e' that new_head to second edge received as part of edge | |
5411 | splitting. | |
5412 | */ | |
5413 | ||
5414 | static void | |
5415 | tree_lv_adjust_loop_header_phi (basic_block first, basic_block second, | |
5416 | basic_block new_head, edge e) | |
5417 | { | |
5418 | tree phi1, phi2; | |
d0e12fc6 KH |
5419 | edge e2 = find_edge (new_head, second); |
5420 | ||
5421 | /* Because NEW_HEAD has been created by splitting SECOND's incoming | |
5422 | edge, we should always have an edge from NEW_HEAD to SECOND. */ | |
5423 | gcc_assert (e2 != NULL); | |
1cb7dfc3 MH |
5424 | |
5425 | /* Browse all 'second' basic block phi nodes and add phi args to | |
5426 | edge 'e' for 'first' head. PHI args are always in correct order. */ | |
5427 | ||
5428 | for (phi2 = phi_nodes (second), phi1 = phi_nodes (first); | |
5429 | phi2 && phi1; | |
5430 | phi2 = PHI_CHAIN (phi2), phi1 = PHI_CHAIN (phi1)) | |
5431 | { | |
d0e12fc6 KH |
5432 | tree def = PHI_ARG_DEF (phi2, e2->dest_idx); |
5433 | add_phi_arg (phi1, def, e); | |
1cb7dfc3 MH |
5434 | } |
5435 | } | |
5436 | ||
5437 | /* Adds a if else statement to COND_BB with condition COND_EXPR. | |
5438 | SECOND_HEAD is the destination of the THEN and FIRST_HEAD is | |
5439 | the destination of the ELSE part. */ | |
5440 | static void | |
5441 | tree_lv_add_condition_to_bb (basic_block first_head, basic_block second_head, | |
5442 | basic_block cond_bb, void *cond_e) | |
5443 | { | |
5444 | block_stmt_iterator bsi; | |
5445 | tree goto1 = NULL_TREE; | |
5446 | tree goto2 = NULL_TREE; | |
5447 | tree new_cond_expr = NULL_TREE; | |
5448 | tree cond_expr = (tree) cond_e; | |
5449 | edge e0; | |
5450 | ||
5451 | /* Build new conditional expr */ | |
5452 | goto1 = build1 (GOTO_EXPR, void_type_node, tree_block_label (first_head)); | |
5453 | goto2 = build1 (GOTO_EXPR, void_type_node, tree_block_label (second_head)); | |
5454 | new_cond_expr = build3 (COND_EXPR, void_type_node, cond_expr, goto1, goto2); | |
5455 | ||
5456 | /* Add new cond in cond_bb. */ | |
5457 | bsi = bsi_start (cond_bb); | |
5458 | bsi_insert_after (&bsi, new_cond_expr, BSI_NEW_STMT); | |
5459 | /* Adjust edges appropriately to connect new head with first head | |
5460 | as well as second head. */ | |
5461 | e0 = single_succ_edge (cond_bb); | |
5462 | e0->flags &= ~EDGE_FALLTHRU; | |
5463 | e0->flags |= EDGE_FALSE_VALUE; | |
5464 | } | |
5465 | ||
6de9cd9a DN |
5466 | struct cfg_hooks tree_cfg_hooks = { |
5467 | "tree", | |
5468 | tree_verify_flow_info, | |
5469 | tree_dump_bb, /* dump_bb */ | |
5470 | create_bb, /* create_basic_block */ | |
5471 | tree_redirect_edge_and_branch,/* redirect_edge_and_branch */ | |
5472 | tree_redirect_edge_and_branch_force,/* redirect_edge_and_branch_force */ | |
5473 | remove_bb, /* delete_basic_block */ | |
5474 | tree_split_block, /* split_block */ | |
5475 | tree_move_block_after, /* move_block_after */ | |
5476 | tree_can_merge_blocks_p, /* can_merge_blocks_p */ | |
5477 | tree_merge_blocks, /* merge_blocks */ | |
5478 | tree_predict_edge, /* predict_edge */ | |
5479 | tree_predicted_by_p, /* predicted_by_p */ | |
5480 | tree_can_duplicate_bb_p, /* can_duplicate_block_p */ | |
5481 | tree_duplicate_bb, /* duplicate_block */ | |
5482 | tree_split_edge, /* split_edge */ | |
5483 | tree_make_forwarder_block, /* make_forward_block */ | |
5484 | NULL, /* tidy_fallthru_edge */ | |
5485 | tree_block_ends_with_call_p, /* block_ends_with_call_p */ | |
5486 | tree_block_ends_with_condjump_p, /* block_ends_with_condjump_p */ | |
d9d4706f | 5487 | tree_flow_call_edges_add, /* flow_call_edges_add */ |
a100ac1e | 5488 | tree_execute_on_growing_pred, /* execute_on_growing_pred */ |
e51546f8 | 5489 | tree_execute_on_shrinking_pred, /* execute_on_shrinking_pred */ |
1cb7dfc3 MH |
5490 | tree_duplicate_loop_to_header_edge, /* duplicate loop for trees */ |
5491 | tree_lv_add_condition_to_bb, /* lv_add_condition_to_bb */ | |
5492 | tree_lv_adjust_loop_header_phi, /* lv_adjust_loop_header_phi*/ | |
5493 | extract_true_false_edges_from_block, /* extract_cond_bb_edges */ | |
5494 | flush_pending_stmts /* flush_pending_stmts */ | |
6de9cd9a DN |
5495 | }; |
5496 | ||
5497 | ||
5498 | /* Split all critical edges. */ | |
5499 | ||
c2924966 | 5500 | static unsigned int |
6de9cd9a DN |
5501 | split_critical_edges (void) |
5502 | { | |
5503 | basic_block bb; | |
5504 | edge e; | |
628f6a4e | 5505 | edge_iterator ei; |
6de9cd9a | 5506 | |
d6be0d7f JL |
5507 | /* split_edge can redirect edges out of SWITCH_EXPRs, which can get |
5508 | expensive. So we want to enable recording of edge to CASE_LABEL_EXPR | |
5509 | mappings around the calls to split_edge. */ | |
5510 | start_recording_case_labels (); | |
6de9cd9a DN |
5511 | FOR_ALL_BB (bb) |
5512 | { | |
628f6a4e | 5513 | FOR_EACH_EDGE (e, ei, bb->succs) |
6de9cd9a DN |
5514 | if (EDGE_CRITICAL_P (e) && !(e->flags & EDGE_ABNORMAL)) |
5515 | { | |
5516 | split_edge (e); | |
5517 | } | |
5518 | } | |
d6be0d7f | 5519 | end_recording_case_labels (); |
c2924966 | 5520 | return 0; |
6de9cd9a DN |
5521 | } |
5522 | ||
5523 | struct tree_opt_pass pass_split_crit_edges = | |
5524 | { | |
5d44aeed | 5525 | "crited", /* name */ |
6de9cd9a DN |
5526 | NULL, /* gate */ |
5527 | split_critical_edges, /* execute */ | |
5528 | NULL, /* sub */ | |
5529 | NULL, /* next */ | |
5530 | 0, /* static_pass_number */ | |
5531 | TV_TREE_SPLIT_EDGES, /* tv_id */ | |
5532 | PROP_cfg, /* properties required */ | |
5533 | PROP_no_crit_edges, /* properties_provided */ | |
5534 | 0, /* properties_destroyed */ | |
5535 | 0, /* todo_flags_start */ | |
9f8628ba PB |
5536 | TODO_dump_func, /* todo_flags_finish */ |
5537 | 0 /* letter */ | |
6de9cd9a | 5538 | }; |
26277d41 PB |
5539 | |
5540 | \f | |
5541 | /* Return EXP if it is a valid GIMPLE rvalue, else gimplify it into | |
5542 | a temporary, make sure and register it to be renamed if necessary, | |
5543 | and finally return the temporary. Put the statements to compute | |
5544 | EXP before the current statement in BSI. */ | |
5545 | ||
5546 | tree | |
5547 | gimplify_val (block_stmt_iterator *bsi, tree type, tree exp) | |
5548 | { | |
5549 | tree t, new_stmt, orig_stmt; | |
5550 | ||
5551 | if (is_gimple_val (exp)) | |
5552 | return exp; | |
5553 | ||
5554 | t = make_rename_temp (type, NULL); | |
b4257cfc | 5555 | new_stmt = build2 (MODIFY_EXPR, type, t, exp); |
26277d41 PB |
5556 | |
5557 | orig_stmt = bsi_stmt (*bsi); | |
5558 | SET_EXPR_LOCUS (new_stmt, EXPR_LOCUS (orig_stmt)); | |
5559 | TREE_BLOCK (new_stmt) = TREE_BLOCK (orig_stmt); | |
5560 | ||
5561 | bsi_insert_before (bsi, new_stmt, BSI_SAME_STMT); | |
5562 | ||
5563 | return t; | |
5564 | } | |
5565 | ||
5566 | /* Build a ternary operation and gimplify it. Emit code before BSI. | |
5567 | Return the gimple_val holding the result. */ | |
5568 | ||
5569 | tree | |
5570 | gimplify_build3 (block_stmt_iterator *bsi, enum tree_code code, | |
5571 | tree type, tree a, tree b, tree c) | |
5572 | { | |
5573 | tree ret; | |
5574 | ||
987b67bc | 5575 | ret = fold_build3 (code, type, a, b, c); |
26277d41 PB |
5576 | STRIP_NOPS (ret); |
5577 | ||
5578 | return gimplify_val (bsi, type, ret); | |
5579 | } | |
5580 | ||
5581 | /* Build a binary operation and gimplify it. Emit code before BSI. | |
5582 | Return the gimple_val holding the result. */ | |
5583 | ||
5584 | tree | |
5585 | gimplify_build2 (block_stmt_iterator *bsi, enum tree_code code, | |
5586 | tree type, tree a, tree b) | |
5587 | { | |
5588 | tree ret; | |
5589 | ||
987b67bc | 5590 | ret = fold_build2 (code, type, a, b); |
26277d41 PB |
5591 | STRIP_NOPS (ret); |
5592 | ||
5593 | return gimplify_val (bsi, type, ret); | |
5594 | } | |
5595 | ||
5596 | /* Build a unary operation and gimplify it. Emit code before BSI. | |
5597 | Return the gimple_val holding the result. */ | |
5598 | ||
5599 | tree | |
5600 | gimplify_build1 (block_stmt_iterator *bsi, enum tree_code code, tree type, | |
5601 | tree a) | |
5602 | { | |
5603 | tree ret; | |
5604 | ||
987b67bc | 5605 | ret = fold_build1 (code, type, a); |
26277d41 PB |
5606 | STRIP_NOPS (ret); |
5607 | ||
5608 | return gimplify_val (bsi, type, ret); | |
5609 | } | |
5610 | ||
5611 | ||
6de9cd9a DN |
5612 | \f |
5613 | /* Emit return warnings. */ | |
5614 | ||
c2924966 | 5615 | static unsigned int |
6de9cd9a DN |
5616 | execute_warn_function_return (void) |
5617 | { | |
9506ac2b PB |
5618 | #ifdef USE_MAPPED_LOCATION |
5619 | source_location location; | |
5620 | #else | |
6de9cd9a | 5621 | location_t *locus; |
9506ac2b | 5622 | #endif |
6de9cd9a DN |
5623 | tree last; |
5624 | edge e; | |
628f6a4e | 5625 | edge_iterator ei; |
6de9cd9a | 5626 | |
6de9cd9a DN |
5627 | /* If we have a path to EXIT, then we do return. */ |
5628 | if (TREE_THIS_VOLATILE (cfun->decl) | |
628f6a4e | 5629 | && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0) |
6de9cd9a | 5630 | { |
9506ac2b PB |
5631 | #ifdef USE_MAPPED_LOCATION |
5632 | location = UNKNOWN_LOCATION; | |
5633 | #else | |
6de9cd9a | 5634 | locus = NULL; |
9506ac2b | 5635 | #endif |
628f6a4e | 5636 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds) |
6de9cd9a DN |
5637 | { |
5638 | last = last_stmt (e->src); | |
5639 | if (TREE_CODE (last) == RETURN_EXPR | |
9506ac2b PB |
5640 | #ifdef USE_MAPPED_LOCATION |
5641 | && (location = EXPR_LOCATION (last)) != UNKNOWN_LOCATION) | |
5642 | #else | |
6de9cd9a | 5643 | && (locus = EXPR_LOCUS (last)) != NULL) |
9506ac2b | 5644 | #endif |
6de9cd9a DN |
5645 | break; |
5646 | } | |
9506ac2b PB |
5647 | #ifdef USE_MAPPED_LOCATION |
5648 | if (location == UNKNOWN_LOCATION) | |
5649 | location = cfun->function_end_locus; | |
d4ee4d25 | 5650 | warning (0, "%H%<noreturn%> function does return", &location); |
9506ac2b | 5651 | #else |
6de9cd9a DN |
5652 | if (!locus) |
5653 | locus = &cfun->function_end_locus; | |
d4ee4d25 | 5654 | warning (0, "%H%<noreturn%> function does return", locus); |
9506ac2b | 5655 | #endif |
6de9cd9a DN |
5656 | } |
5657 | ||
5658 | /* If we see "return;" in some basic block, then we do reach the end | |
5659 | without returning a value. */ | |
5660 | else if (warn_return_type | |
089efaa4 | 5661 | && !TREE_NO_WARNING (cfun->decl) |
628f6a4e | 5662 | && EDGE_COUNT (EXIT_BLOCK_PTR->preds) > 0 |
6de9cd9a DN |
5663 | && !VOID_TYPE_P (TREE_TYPE (TREE_TYPE (cfun->decl)))) |
5664 | { | |
628f6a4e | 5665 | FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds) |
6de9cd9a DN |
5666 | { |
5667 | tree last = last_stmt (e->src); | |
5668 | if (TREE_CODE (last) == RETURN_EXPR | |
0c9b182b JJ |
5669 | && TREE_OPERAND (last, 0) == NULL |
5670 | && !TREE_NO_WARNING (last)) | |
6de9cd9a | 5671 | { |
9506ac2b PB |
5672 | #ifdef USE_MAPPED_LOCATION |
5673 | location = EXPR_LOCATION (last); | |
5674 | if (location == UNKNOWN_LOCATION) | |
5675 | location = cfun->function_end_locus; | |
d4ee4d25 | 5676 | warning (0, "%Hcontrol reaches end of non-void function", &location); |
9506ac2b | 5677 | #else |
6de9cd9a DN |
5678 | locus = EXPR_LOCUS (last); |
5679 | if (!locus) | |
5680 | locus = &cfun->function_end_locus; | |
d4ee4d25 | 5681 | warning (0, "%Hcontrol reaches end of non-void function", locus); |
9506ac2b | 5682 | #endif |
089efaa4 | 5683 | TREE_NO_WARNING (cfun->decl) = 1; |
6de9cd9a DN |
5684 | break; |
5685 | } | |
5686 | } | |
5687 | } | |
c2924966 | 5688 | return 0; |
6de9cd9a DN |
5689 | } |
5690 | ||
5691 | ||
5692 | /* Given a basic block B which ends with a conditional and has | |
5693 | precisely two successors, determine which of the edges is taken if | |
5694 | the conditional is true and which is taken if the conditional is | |
5695 | false. Set TRUE_EDGE and FALSE_EDGE appropriately. */ | |
5696 | ||
5697 | void | |
5698 | extract_true_false_edges_from_block (basic_block b, | |
5699 | edge *true_edge, | |
5700 | edge *false_edge) | |
5701 | { | |
628f6a4e | 5702 | edge e = EDGE_SUCC (b, 0); |
6de9cd9a DN |
5703 | |
5704 | if (e->flags & EDGE_TRUE_VALUE) | |
5705 | { | |
5706 | *true_edge = e; | |
628f6a4e | 5707 | *false_edge = EDGE_SUCC (b, 1); |
6de9cd9a DN |
5708 | } |
5709 | else | |
5710 | { | |
5711 | *false_edge = e; | |
628f6a4e | 5712 | *true_edge = EDGE_SUCC (b, 1); |
6de9cd9a DN |
5713 | } |
5714 | } | |
5715 | ||
5716 | struct tree_opt_pass pass_warn_function_return = | |
5717 | { | |
5718 | NULL, /* name */ | |
5719 | NULL, /* gate */ | |
5720 | execute_warn_function_return, /* execute */ | |
5721 | NULL, /* sub */ | |
5722 | NULL, /* next */ | |
5723 | 0, /* static_pass_number */ | |
5724 | 0, /* tv_id */ | |
00bfee6f | 5725 | PROP_cfg, /* properties_required */ |
6de9cd9a DN |
5726 | 0, /* properties_provided */ |
5727 | 0, /* properties_destroyed */ | |
5728 | 0, /* todo_flags_start */ | |
9f8628ba PB |
5729 | 0, /* todo_flags_finish */ |
5730 | 0 /* letter */ | |
6de9cd9a | 5731 | }; |
aa313ed4 JH |
5732 | |
5733 | /* Emit noreturn warnings. */ | |
5734 | ||
c2924966 | 5735 | static unsigned int |
aa313ed4 JH |
5736 | execute_warn_function_noreturn (void) |
5737 | { | |
5738 | if (warn_missing_noreturn | |
5739 | && !TREE_THIS_VOLATILE (cfun->decl) | |
5740 | && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0 | |
5741 | && !lang_hooks.function.missing_noreturn_ok_p (cfun->decl)) | |
3176a0c2 DD |
5742 | warning (OPT_Wmissing_noreturn, "%Jfunction might be possible candidate " |
5743 | "for attribute %<noreturn%>", | |
aa313ed4 | 5744 | cfun->decl); |
c2924966 | 5745 | return 0; |
aa313ed4 JH |
5746 | } |
5747 | ||
5748 | struct tree_opt_pass pass_warn_function_noreturn = | |
5749 | { | |
5750 | NULL, /* name */ | |
5751 | NULL, /* gate */ | |
5752 | execute_warn_function_noreturn, /* execute */ | |
5753 | NULL, /* sub */ | |
5754 | NULL, /* next */ | |
5755 | 0, /* static_pass_number */ | |
5756 | 0, /* tv_id */ | |
5757 | PROP_cfg, /* properties_required */ | |
5758 | 0, /* properties_provided */ | |
5759 | 0, /* properties_destroyed */ | |
5760 | 0, /* todo_flags_start */ | |
5761 | 0, /* todo_flags_finish */ | |
5762 | 0 /* letter */ | |
5763 | }; |