1 | /* GIMPLE lowering pass. Converts High GIMPLE into Low GIMPLE. |
2 | |
3 | Copyright (C) 2003-2023 Free Software Foundation, Inc. |
4 | |
5 | This file is part of GCC. |
6 | |
7 | GCC is free software; you can redistribute it and/or modify it under |
8 | the terms of the GNU General Public License as published by the Free |
9 | Software Foundation; either version 3, or (at your option) any later |
10 | version. |
11 | |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
15 | for more details. |
16 | |
17 | You should have received a copy of the GNU General Public License |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ |
20 | |
21 | #include "config.h" |
22 | #include "system.h" |
23 | #include "coretypes.h" |
24 | #include "backend.h" |
25 | #include "tree.h" |
26 | #include "gimple.h" |
27 | #include "tree-pass.h" |
28 | #include "fold-const.h" |
29 | #include "tree-nested.h" |
30 | #include "calls.h" |
31 | #include "gimple-iterator.h" |
32 | #include "gimple-low.h" |
33 | #include "predict.h" |
34 | #include "gimple-predict.h" |
35 | #include "gimple-fold.h" |
36 | #include "cgraph.h" |
37 | #include "tree-ssa.h" |
38 | #include "value-range.h" |
39 | #include "stringpool.h" |
40 | #include "tree-ssanames.h" |
41 | #include "tree-inline.h" |
42 | #include "gimple-walk.h" |
43 | #include "attribs.h" |
44 | |
45 | /* The differences between High GIMPLE and Low GIMPLE are the |
46 | following: |
47 | |
48 | 1- Lexical scopes are removed (i.e., GIMPLE_BIND disappears). |
49 | |
50 | 2- GIMPLE_TRY and GIMPLE_CATCH are converted to abnormal control |
51 | flow and exception regions are built as an on-the-side region |
52 | hierarchy (See tree-eh.cc:lower_eh_constructs). |
53 | |
54 | 3- Multiple identical return statements are grouped into a single |
55 | return and gotos to the unique return site. */ |
56 | |
57 | /* Match a return statement with a label. During lowering, we identify |
58 | identical return statements and replace duplicates with a jump to |
59 | the corresponding label. */ |
60 | struct return_statements_t |
61 | { |
62 | tree label; |
63 | greturn *stmt; |
64 | }; |
65 | typedef struct return_statements_t return_statements_t; |
66 | |
67 | |
68 | struct lower_data |
69 | { |
70 | /* Block the current statement belongs to. */ |
71 | tree block; |
72 | |
73 | /* A vector of label and return statements to be moved to the end |
74 | of the function. */ |
75 | vec<return_statements_t> return_statements; |
76 | |
77 | /* True if the current statement cannot fall through. */ |
78 | bool cannot_fallthru; |
79 | }; |
80 | |
81 | static void lower_stmt (gimple_stmt_iterator *, struct lower_data *); |
82 | static void lower_gimple_bind (gimple_stmt_iterator *, struct lower_data *); |
83 | static void lower_try_catch (gimple_stmt_iterator *, struct lower_data *); |
84 | static void lower_gimple_return (gimple_stmt_iterator *, struct lower_data *); |
85 | static void lower_builtin_setjmp (gimple_stmt_iterator *); |
86 | static void lower_builtin_posix_memalign (gimple_stmt_iterator *); |
87 | static void lower_builtin_assume_aligned (gimple_stmt_iterator *); |
88 | |
89 | |
90 | /* Lower the body of current_function_decl from High GIMPLE into Low |
91 | GIMPLE. */ |
92 | |
93 | static unsigned int |
94 | lower_function_body (void) |
95 | { |
96 | struct lower_data data; |
97 | gimple_seq body = gimple_body (current_function_decl); |
98 | gimple_seq lowered_body; |
99 | gimple_stmt_iterator i; |
100 | gimple *bind; |
101 | gimple *x; |
102 | |
103 | /* The gimplifier should've left a body of exactly one statement, |
104 | namely a GIMPLE_BIND. */ |
105 | gcc_assert (gimple_seq_first (body) == gimple_seq_last (body) |
106 | && gimple_code (gimple_seq_first_stmt (body)) == GIMPLE_BIND); |
107 | |
108 | memset (s: &data, c: 0, n: sizeof (data)); |
109 | data.block = DECL_INITIAL (current_function_decl); |
110 | BLOCK_SUBBLOCKS (data.block) = NULL_TREE; |
111 | BLOCK_CHAIN (data.block) = NULL_TREE; |
112 | TREE_ASM_WRITTEN (data.block) = 1; |
113 | data.return_statements.create (nelems: 8); |
114 | |
115 | bind = gimple_seq_first_stmt (s: body); |
116 | lowered_body = NULL; |
117 | gimple_seq_add_stmt (&lowered_body, bind); |
118 | i = gsi_start (seq&: lowered_body); |
119 | lower_gimple_bind (&i, &data); |
120 | |
121 | i = gsi_last (seq&: lowered_body); |
122 | |
123 | /* If we had begin stmt markers from e.g. PCH, but this compilation |
124 | doesn't want them, lower_stmt will have cleaned them up; we can |
125 | now clear the flag that indicates we had them. */ |
126 | if (!MAY_HAVE_DEBUG_MARKER_STMTS && cfun->debug_nonbind_markers) |
127 | { |
128 | /* This counter needs not be exact, but before lowering it will |
129 | most certainly be. */ |
130 | gcc_assert (cfun->debug_marker_count == 0); |
131 | cfun->debug_nonbind_markers = false; |
132 | } |
133 | |
134 | /* If the function falls off the end, we need a null return statement. |
135 | If we've already got one in the return_statements vector, we don't |
136 | need to do anything special. Otherwise build one by hand. */ |
137 | bool may_fallthru = gimple_seq_may_fallthru (lowered_body); |
138 | if (may_fallthru |
139 | && (data.return_statements.is_empty () |
140 | || (gimple_return_retval (gs: data.return_statements.last().stmt) |
141 | != NULL))) |
142 | { |
143 | x = gimple_build_return (NULL); |
144 | gimple_set_location (g: x, cfun->function_end_locus); |
145 | gimple_set_block (g: x, DECL_INITIAL (current_function_decl)); |
146 | gsi_insert_after (&i, x, GSI_CONTINUE_LINKING); |
147 | may_fallthru = false; |
148 | } |
149 | |
150 | /* If we lowered any return statements, emit the representative |
151 | at the end of the function. */ |
152 | while (!data.return_statements.is_empty ()) |
153 | { |
154 | return_statements_t t = data.return_statements.pop (); |
155 | x = gimple_build_label (label: t.label); |
156 | gsi_insert_after (&i, x, GSI_CONTINUE_LINKING); |
157 | gsi_insert_after (&i, t.stmt, GSI_CONTINUE_LINKING); |
158 | if (may_fallthru) |
159 | { |
160 | /* Remove the line number from the representative return statement. |
161 | It now fills in for the fallthru too. Failure to remove this |
162 | will result in incorrect results for coverage analysis. */ |
163 | gimple_set_location (g: t.stmt, UNKNOWN_LOCATION); |
164 | may_fallthru = false; |
165 | } |
166 | } |
167 | |
168 | /* Once the old body has been lowered, replace it with the new |
169 | lowered sequence. */ |
170 | gimple_set_body (current_function_decl, lowered_body); |
171 | |
172 | gcc_assert (data.block == DECL_INITIAL (current_function_decl)); |
173 | BLOCK_SUBBLOCKS (data.block) |
174 | = blocks_nreverse (BLOCK_SUBBLOCKS (data.block)); |
175 | |
176 | clear_block_marks (data.block); |
177 | data.return_statements.release (); |
178 | return 0; |
179 | } |
180 | |
181 | namespace { |
182 | |
183 | const pass_data pass_data_lower_cf = |
184 | { |
185 | .type: GIMPLE_PASS, /* type */ |
186 | .name: "lower" , /* name */ |
187 | .optinfo_flags: OPTGROUP_NONE, /* optinfo_flags */ |
188 | .tv_id: TV_NONE, /* tv_id */ |
189 | PROP_gimple_any, /* properties_required */ |
190 | PROP_gimple_lcf, /* properties_provided */ |
191 | .properties_destroyed: 0, /* properties_destroyed */ |
192 | .todo_flags_start: 0, /* todo_flags_start */ |
193 | .todo_flags_finish: 0, /* todo_flags_finish */ |
194 | }; |
195 | |
196 | class pass_lower_cf : public gimple_opt_pass |
197 | { |
198 | public: |
199 | pass_lower_cf (gcc::context *ctxt) |
200 | : gimple_opt_pass (pass_data_lower_cf, ctxt) |
201 | {} |
202 | |
203 | /* opt_pass methods: */ |
204 | unsigned int execute (function *) final override |
205 | { |
206 | return lower_function_body (); |
207 | } |
208 | |
209 | }; // class pass_lower_cf |
210 | |
211 | } // anon namespace |
212 | |
213 | gimple_opt_pass * |
214 | make_pass_lower_cf (gcc::context *ctxt) |
215 | { |
216 | return new pass_lower_cf (ctxt); |
217 | } |
218 | |
219 | /* Lower sequence SEQ. Unlike gimplification the statements are not relowered |
220 | when they are changed -- if this has to be done, the lowering routine must |
221 | do it explicitly. DATA is passed through the recursion. */ |
222 | |
223 | static void |
224 | lower_sequence (gimple_seq *seq, struct lower_data *data) |
225 | { |
226 | gimple_stmt_iterator gsi; |
227 | |
228 | for (gsi = gsi_start (seq&: *seq); !gsi_end_p (i: gsi); ) |
229 | lower_stmt (&gsi, data); |
230 | } |
231 | |
232 | |
233 | /* Lower the OpenMP directive statement pointed by GSI. DATA is |
234 | passed through the recursion. */ |
235 | |
236 | static void |
237 | lower_omp_directive (gimple_stmt_iterator *gsi, struct lower_data *data) |
238 | { |
239 | gimple *stmt; |
240 | |
241 | stmt = gsi_stmt (i: *gsi); |
242 | |
243 | lower_sequence (seq: gimple_omp_body_ptr (gs: stmt), data); |
244 | gsi_insert_seq_after (gsi, gimple_omp_body (gs: stmt), GSI_CONTINUE_LINKING); |
245 | gimple_omp_set_body (gs: stmt, NULL); |
246 | gsi_next (i: gsi); |
247 | } |
248 | |
249 | /* Create an artificial FUNCTION_DECL for assumption at LOC. */ |
250 | |
251 | static tree |
252 | create_assumption_fn (location_t loc) |
253 | { |
254 | tree name = clone_function_name_numbered (decl: current_function_decl, suffix: "_assume" ); |
255 | /* Temporarily, until we determine all the arguments. */ |
256 | tree type = build_varargs_function_type_list (boolean_type_node, NULL_TREE); |
257 | tree decl = build_decl (loc, FUNCTION_DECL, name, type); |
258 | TREE_STATIC (decl) = 1; |
259 | TREE_USED (decl) = 1; |
260 | DECL_ARTIFICIAL (decl) = 1; |
261 | DECL_IGNORED_P (decl) = 1; |
262 | DECL_NAMELESS (decl) = 1; |
263 | TREE_PUBLIC (decl) = 0; |
264 | DECL_UNINLINABLE (decl) = 1; |
265 | DECL_EXTERNAL (decl) = 0; |
266 | DECL_CONTEXT (decl) = NULL_TREE; |
267 | DECL_INITIAL (decl) = make_node (BLOCK); |
268 | tree attributes = DECL_ATTRIBUTES (current_function_decl); |
269 | if (lookup_attribute (attr_name: "noipa" , list: attributes) == NULL) |
270 | { |
271 | attributes = tree_cons (get_identifier ("noipa" ), NULL, attributes); |
272 | if (lookup_attribute (attr_name: "noinline" , list: attributes) == NULL) |
273 | attributes = tree_cons (get_identifier ("noinline" ), NULL, attributes); |
274 | if (lookup_attribute (attr_name: "noclone" , list: attributes) == NULL) |
275 | attributes = tree_cons (get_identifier ("noclone" ), NULL, attributes); |
276 | if (lookup_attribute (attr_name: "no_icf" , list: attributes) == NULL) |
277 | attributes = tree_cons (get_identifier ("no_icf" ), NULL, attributes); |
278 | } |
279 | DECL_ATTRIBUTES (decl) = attributes; |
280 | BLOCK_SUPERCONTEXT (DECL_INITIAL (decl)) = decl; |
281 | DECL_FUNCTION_SPECIFIC_OPTIMIZATION (decl) |
282 | = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (current_function_decl); |
283 | DECL_FUNCTION_SPECIFIC_TARGET (decl) |
284 | = DECL_FUNCTION_SPECIFIC_TARGET (current_function_decl); |
285 | tree t = build_decl (DECL_SOURCE_LOCATION (decl), |
286 | RESULT_DECL, NULL_TREE, boolean_type_node); |
287 | DECL_ARTIFICIAL (t) = 1; |
288 | DECL_IGNORED_P (t) = 1; |
289 | DECL_CONTEXT (t) = decl; |
290 | DECL_RESULT (decl) = t; |
291 | push_struct_function (fndecl: decl); |
292 | cfun->function_end_locus = loc; |
293 | init_tree_ssa (cfun); |
294 | return decl; |
295 | } |
296 | |
297 | struct lower_assumption_data |
298 | { |
299 | copy_body_data id; |
300 | tree return_false_label; |
301 | tree guard_copy; |
302 | auto_vec<tree> decls; |
303 | }; |
304 | |
305 | /* Helper function for lower_assumptions. Find local vars and labels |
306 | in the assumption sequence and remove debug stmts. */ |
307 | |
308 | static tree |
309 | find_assumption_locals_r (gimple_stmt_iterator *gsi_p, bool *, |
310 | struct walk_stmt_info *wi) |
311 | { |
312 | lower_assumption_data *data = (lower_assumption_data *) wi->info; |
313 | gimple *stmt = gsi_stmt (i: *gsi_p); |
314 | tree lhs = gimple_get_lhs (stmt); |
315 | if (lhs && TREE_CODE (lhs) == SSA_NAME) |
316 | { |
317 | gcc_assert (SSA_NAME_VAR (lhs) == NULL_TREE); |
318 | data->id.decl_map->put (k: lhs, NULL_TREE); |
319 | data->decls.safe_push (obj: lhs); |
320 | } |
321 | switch (gimple_code (g: stmt)) |
322 | { |
323 | case GIMPLE_BIND: |
324 | for (tree var = gimple_bind_vars (bind_stmt: as_a <gbind *> (p: stmt)); |
325 | var; var = DECL_CHAIN (var)) |
326 | if (VAR_P (var) |
327 | && !DECL_EXTERNAL (var) |
328 | && DECL_CONTEXT (var) == data->id.src_fn) |
329 | { |
330 | data->id.decl_map->put (k: var, v: var); |
331 | data->decls.safe_push (obj: var); |
332 | } |
333 | break; |
334 | case GIMPLE_LABEL: |
335 | { |
336 | tree label = gimple_label_label (gs: as_a <glabel *> (p: stmt)); |
337 | data->id.decl_map->put (k: label, v: label); |
338 | break; |
339 | } |
340 | case GIMPLE_RETURN: |
341 | /* If something in assumption tries to return from parent function, |
342 | if it would be reached in hypothetical evaluation, it would be UB, |
343 | so transform such returns into return false; */ |
344 | { |
345 | gimple *g = gimple_build_assign (data->guard_copy, boolean_false_node); |
346 | gsi_insert_before (gsi_p, g, GSI_SAME_STMT); |
347 | gimple_return_set_retval (gs: as_a <greturn *> (p: stmt), retval: data->guard_copy); |
348 | break; |
349 | } |
350 | case GIMPLE_DEBUG: |
351 | /* As assumptions won't be emitted, debug info stmts in them |
352 | are useless. */ |
353 | gsi_remove (gsi_p, true); |
354 | wi->removed_stmt = true; |
355 | break; |
356 | default: |
357 | break; |
358 | } |
359 | return NULL_TREE; |
360 | } |
361 | |
362 | /* Create a new PARM_DECL that is indentical in all respect to DECL except that |
363 | DECL can be either a VAR_DECL, a PARM_DECL or RESULT_DECL. The original |
364 | DECL must come from ID->src_fn and the copy will be part of ID->dst_fn. */ |
365 | |
366 | static tree |
367 | assumption_copy_decl (tree decl, copy_body_data *id) |
368 | { |
369 | tree type = TREE_TYPE (decl); |
370 | |
371 | if (is_global_var (t: decl)) |
372 | return decl; |
373 | |
374 | gcc_assert (VAR_P (decl) |
375 | || TREE_CODE (decl) == PARM_DECL |
376 | || TREE_CODE (decl) == RESULT_DECL); |
377 | tree copy = build_decl (DECL_SOURCE_LOCATION (decl), |
378 | PARM_DECL, DECL_NAME (decl), type); |
379 | if (DECL_PT_UID_SET_P (decl)) |
380 | SET_DECL_PT_UID (copy, DECL_PT_UID (decl)); |
381 | TREE_ADDRESSABLE (copy) = TREE_ADDRESSABLE (decl); |
382 | TREE_READONLY (copy) = TREE_READONLY (decl); |
383 | TREE_THIS_VOLATILE (copy) = TREE_THIS_VOLATILE (decl); |
384 | DECL_NOT_GIMPLE_REG_P (copy) = DECL_NOT_GIMPLE_REG_P (decl); |
385 | DECL_BY_REFERENCE (copy) = DECL_BY_REFERENCE (decl); |
386 | DECL_ARG_TYPE (copy) = type; |
387 | ((lower_assumption_data *) id)->decls.safe_push (obj: decl); |
388 | return copy_decl_for_dup_finish (id, decl, copy); |
389 | } |
390 | |
391 | /* Transform gotos out of the assumption into return false. */ |
392 | |
393 | static tree |
394 | adjust_assumption_stmt_r (gimple_stmt_iterator *gsi_p, bool *, |
395 | struct walk_stmt_info *wi) |
396 | { |
397 | lower_assumption_data *data = (lower_assumption_data *) wi->info; |
398 | gimple *stmt = gsi_stmt (i: *gsi_p); |
399 | tree lab = NULL_TREE; |
400 | unsigned int idx = 0; |
401 | if (gimple_code (g: stmt) == GIMPLE_GOTO) |
402 | lab = gimple_goto_dest (gs: stmt); |
403 | else if (gimple_code (g: stmt) == GIMPLE_COND) |
404 | { |
405 | repeat: |
406 | if (idx == 0) |
407 | lab = gimple_cond_true_label (gs: as_a <gcond *> (p: stmt)); |
408 | else |
409 | lab = gimple_cond_false_label (gs: as_a <gcond *> (p: stmt)); |
410 | } |
411 | else if (gimple_code (g: stmt) == GIMPLE_LABEL) |
412 | { |
413 | tree label = gimple_label_label (gs: as_a <glabel *> (p: stmt)); |
414 | DECL_CONTEXT (label) = current_function_decl; |
415 | } |
416 | if (lab) |
417 | { |
418 | if (!data->id.decl_map->get (k: lab)) |
419 | { |
420 | if (!data->return_false_label) |
421 | data->return_false_label |
422 | = create_artificial_label (UNKNOWN_LOCATION); |
423 | if (gimple_code (g: stmt) == GIMPLE_GOTO) |
424 | gimple_goto_set_dest (gs: as_a <ggoto *> (p: stmt), |
425 | dest: data->return_false_label); |
426 | else if (idx == 0) |
427 | gimple_cond_set_true_label (gs: as_a <gcond *> (p: stmt), |
428 | label: data->return_false_label); |
429 | else |
430 | gimple_cond_set_false_label (gs: as_a <gcond *> (p: stmt), |
431 | label: data->return_false_label); |
432 | } |
433 | if (gimple_code (g: stmt) == GIMPLE_COND && idx == 0) |
434 | { |
435 | idx = 1; |
436 | goto repeat; |
437 | } |
438 | } |
439 | return NULL_TREE; |
440 | } |
441 | |
442 | /* Adjust trees in the assumption body. Called through walk_tree. */ |
443 | |
444 | static tree |
445 | adjust_assumption_stmt_op (tree *tp, int *, void *datap) |
446 | { |
447 | struct walk_stmt_info *wi = (struct walk_stmt_info *) datap; |
448 | lower_assumption_data *data = (lower_assumption_data *) wi->info; |
449 | tree t = *tp; |
450 | tree *newt; |
451 | switch (TREE_CODE (t)) |
452 | { |
453 | case SSA_NAME: |
454 | newt = data->id.decl_map->get (k: t); |
455 | /* There shouldn't be SSA_NAMEs other than ones defined in the |
456 | assumption's body. */ |
457 | gcc_assert (newt); |
458 | *tp = *newt; |
459 | break; |
460 | case LABEL_DECL: |
461 | newt = data->id.decl_map->get (k: t); |
462 | if (newt) |
463 | *tp = *newt; |
464 | break; |
465 | case VAR_DECL: |
466 | case PARM_DECL: |
467 | case RESULT_DECL: |
468 | *tp = remap_decl (decl: t, id: &data->id); |
469 | break; |
470 | default: |
471 | break; |
472 | } |
473 | return NULL_TREE; |
474 | } |
475 | |
476 | /* Lower assumption. |
477 | The gimplifier transformed: |
478 | .ASSUME (cond); |
479 | into: |
480 | [[assume (guard)]] |
481 | { |
482 | guard = cond; |
483 | } |
484 | which we should transform into: |
485 | .ASSUME (&artificial_fn, args...); |
486 | where artificial_fn will look like: |
487 | bool artificial_fn (args...) |
488 | { |
489 | guard = cond; |
490 | return guard; |
491 | } |
492 | with any debug stmts in the block removed and jumps out of |
493 | the block or return stmts replaced with return false; */ |
494 | |
495 | static void |
496 | lower_assumption (gimple_stmt_iterator *gsi, struct lower_data *data) |
497 | { |
498 | gimple *stmt = gsi_stmt (i: *gsi); |
499 | tree guard = gimple_assume_guard (gs: stmt); |
500 | gimple *bind = gimple_assume_body (gs: stmt); |
501 | location_t loc = gimple_location (g: stmt); |
502 | gcc_assert (gimple_code (bind) == GIMPLE_BIND); |
503 | |
504 | lower_assumption_data lad; |
505 | hash_map<tree, tree> decl_map; |
506 | memset (s: &lad.id, c: 0, n: sizeof (lad.id)); |
507 | lad.return_false_label = NULL_TREE; |
508 | lad.id.src_fn = current_function_decl; |
509 | lad.id.dst_fn = create_assumption_fn (loc); |
510 | lad.id.src_cfun = DECL_STRUCT_FUNCTION (lad.id.src_fn); |
511 | lad.id.decl_map = &decl_map; |
512 | lad.id.copy_decl = assumption_copy_decl; |
513 | lad.id.transform_call_graph_edges = CB_CGE_DUPLICATE; |
514 | lad.id.transform_parameter = true; |
515 | lad.id.do_not_unshare = true; |
516 | lad.id.do_not_fold = true; |
517 | cfun->curr_properties = lad.id.src_cfun->curr_properties; |
518 | lad.guard_copy = create_tmp_var (boolean_type_node); |
519 | decl_map.put (k: lad.guard_copy, v: lad.guard_copy); |
520 | decl_map.put (k: guard, v: lad.guard_copy); |
521 | cfun->assume_function = 1; |
522 | |
523 | /* Find variables, labels and SSA_NAMEs local to the assume GIMPLE_BIND. */ |
524 | gimple_stmt_iterator gsi2 = gsi_start (seq&: *gimple_assume_body_ptr (gs: stmt)); |
525 | struct walk_stmt_info wi; |
526 | memset (s: &wi, c: 0, n: sizeof (wi)); |
527 | wi.info = (void *) &lad; |
528 | walk_gimple_stmt (&gsi2, find_assumption_locals_r, NULL, &wi); |
529 | unsigned int sz = lad.decls.length (); |
530 | for (unsigned i = 0; i < sz; ++i) |
531 | { |
532 | tree v = lad.decls[i]; |
533 | tree newv; |
534 | /* SSA_NAMEs defined in the assume condition should be replaced |
535 | by new SSA_NAMEs in the artificial function. */ |
536 | if (TREE_CODE (v) == SSA_NAME) |
537 | { |
538 | newv = make_ssa_name (var: remap_type (TREE_TYPE (v), id: &lad.id)); |
539 | decl_map.put (k: v, v: newv); |
540 | } |
541 | /* Local vars should have context and type adjusted to the |
542 | new artificial function. */ |
543 | else if (VAR_P (v)) |
544 | { |
545 | if (is_global_var (t: v) && !DECL_ASSEMBLER_NAME_SET_P (v)) |
546 | DECL_ASSEMBLER_NAME (v); |
547 | TREE_TYPE (v) = remap_type (TREE_TYPE (v), id: &lad.id); |
548 | DECL_CONTEXT (v) = current_function_decl; |
549 | } |
550 | } |
551 | /* References to other automatic vars should be replaced by |
552 | PARM_DECLs to the artificial function. */ |
553 | memset (s: &wi, c: 0, n: sizeof (wi)); |
554 | wi.info = (void *) &lad; |
555 | walk_gimple_stmt (&gsi2, adjust_assumption_stmt_r, |
556 | adjust_assumption_stmt_op, &wi); |
557 | |
558 | /* At the start prepend guard = false; */ |
559 | gimple_seq body = NULL; |
560 | gimple *g = gimple_build_assign (lad.guard_copy, boolean_false_node); |
561 | gimple_seq_add_stmt (&body, g); |
562 | gimple_seq_add_stmt (&body, bind); |
563 | /* At the end add return guard; */ |
564 | greturn *gr = gimple_build_return (lad.guard_copy); |
565 | gimple_seq_add_stmt (&body, gr); |
566 | /* If there were any jumps to labels outside of the condition, |
567 | replace them with a jump to |
568 | return_false_label: |
569 | guard = false; |
570 | return guard; */ |
571 | if (lad.return_false_label) |
572 | { |
573 | g = gimple_build_label (label: lad.return_false_label); |
574 | gimple_seq_add_stmt (&body, g); |
575 | g = gimple_build_assign (lad.guard_copy, boolean_false_node); |
576 | gimple_seq_add_stmt (&body, g); |
577 | gr = gimple_build_return (lad.guard_copy); |
578 | gimple_seq_add_stmt (&body, gr); |
579 | } |
580 | bind = gimple_build_bind (NULL_TREE, body, NULL_TREE); |
581 | body = NULL; |
582 | gimple_seq_add_stmt (&body, bind); |
583 | gimple_set_body (current_function_decl, body); |
584 | pop_cfun (); |
585 | |
586 | tree parms = NULL_TREE; |
587 | tree parmt = void_list_node; |
588 | auto_vec<tree, 8> vargs; |
589 | vargs.safe_grow (len: 1 + (lad.decls.length () - sz), exact: true); |
590 | /* First argument to IFN_ASSUME will be address of the |
591 | artificial function. */ |
592 | vargs[0] = build_fold_addr_expr (lad.id.dst_fn); |
593 | for (unsigned i = lad.decls.length (); i > sz; --i) |
594 | { |
595 | tree *v = decl_map.get (k: lad.decls[i - 1]); |
596 | gcc_assert (v && TREE_CODE (*v) == PARM_DECL); |
597 | DECL_CHAIN (*v) = parms; |
598 | parms = *v; |
599 | parmt = tree_cons (NULL_TREE, TREE_TYPE (*v), parmt); |
600 | /* Remaining arguments will be the variables/parameters |
601 | mentioned in the condition. */ |
602 | vargs[i - sz] = lad.decls[i - 1]; |
603 | /* If they have gimple types, we might need to regimplify |
604 | them to make the IFN_ASSUME call valid. */ |
605 | if (is_gimple_reg_type (TREE_TYPE (vargs[i - sz])) |
606 | && !is_gimple_val (vargs[i - sz])) |
607 | { |
608 | tree t = make_ssa_name (TREE_TYPE (vargs[i - sz])); |
609 | g = gimple_build_assign (t, vargs[i - sz]); |
610 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
611 | vargs[i - sz] = t; |
612 | } |
613 | } |
614 | DECL_ARGUMENTS (lad.id.dst_fn) = parms; |
615 | TREE_TYPE (lad.id.dst_fn) = build_function_type (boolean_type_node, parmt); |
616 | |
617 | cgraph_node::add_new_function (fndecl: lad.id.dst_fn, lowered: false); |
618 | |
619 | for (unsigned i = 0; i < sz; ++i) |
620 | { |
621 | tree v = lad.decls[i]; |
622 | if (TREE_CODE (v) == SSA_NAME) |
623 | release_ssa_name (name: v); |
624 | } |
625 | |
626 | data->cannot_fallthru = false; |
627 | /* Replace GIMPLE_ASSUME statement with IFN_ASSUME call. */ |
628 | gcall *call = gimple_build_call_internal_vec (IFN_ASSUME, vargs); |
629 | gimple_set_location (g: call, location: loc); |
630 | gsi_replace (gsi, call, true); |
631 | } |
632 | |
633 | /* Lower statement GSI. DATA is passed through the recursion. We try to |
634 | track the fallthruness of statements and get rid of unreachable return |
635 | statements in order to prevent the EH lowering pass from adding useless |
636 | edges that can cause bogus warnings to be issued later; this guess need |
637 | not be 100% accurate, simply be conservative and reset cannot_fallthru |
638 | to false if we don't know. */ |
639 | |
640 | static void |
641 | lower_stmt (gimple_stmt_iterator *gsi, struct lower_data *data) |
642 | { |
643 | gimple *stmt = gsi_stmt (i: *gsi); |
644 | |
645 | gimple_set_block (g: stmt, block: data->block); |
646 | |
647 | switch (gimple_code (g: stmt)) |
648 | { |
649 | case GIMPLE_BIND: |
650 | lower_gimple_bind (gsi, data); |
651 | /* Propagate fallthruness. */ |
652 | return; |
653 | |
654 | case GIMPLE_COND: |
655 | case GIMPLE_GOTO: |
656 | case GIMPLE_SWITCH: |
657 | data->cannot_fallthru = true; |
658 | gsi_next (i: gsi); |
659 | return; |
660 | |
661 | case GIMPLE_RETURN: |
662 | if (data->cannot_fallthru) |
663 | { |
664 | gsi_remove (gsi, false); |
665 | /* Propagate fallthruness. */ |
666 | } |
667 | else |
668 | { |
669 | lower_gimple_return (gsi, data); |
670 | data->cannot_fallthru = true; |
671 | } |
672 | return; |
673 | |
674 | case GIMPLE_TRY: |
675 | if (gimple_try_kind (gs: stmt) == GIMPLE_TRY_CATCH) |
676 | lower_try_catch (gsi, data); |
677 | else |
678 | { |
679 | /* It must be a GIMPLE_TRY_FINALLY. */ |
680 | bool cannot_fallthru; |
681 | lower_sequence (seq: gimple_try_eval_ptr (gs: stmt), data); |
682 | cannot_fallthru = data->cannot_fallthru; |
683 | |
684 | /* The finally clause is always executed after the try clause, |
685 | so if it does not fall through, then the try-finally will not |
686 | fall through. Otherwise, if the try clause does not fall |
687 | through, then when the finally clause falls through it will |
688 | resume execution wherever the try clause was going. So the |
689 | whole try-finally will only fall through if both the try |
690 | clause and the finally clause fall through. */ |
691 | data->cannot_fallthru = false; |
692 | lower_sequence (seq: gimple_try_cleanup_ptr (gs: stmt), data); |
693 | data->cannot_fallthru |= cannot_fallthru; |
694 | gsi_next (i: gsi); |
695 | } |
696 | return; |
697 | |
698 | case GIMPLE_EH_ELSE: |
699 | { |
700 | geh_else *eh_else_stmt = as_a <geh_else *> (p: stmt); |
701 | lower_sequence (seq: gimple_eh_else_n_body_ptr (eh_else_stmt), data); |
702 | lower_sequence (seq: gimple_eh_else_e_body_ptr (eh_else_stmt), data); |
703 | } |
704 | break; |
705 | |
706 | case GIMPLE_DEBUG: |
707 | gcc_checking_assert (cfun->debug_nonbind_markers); |
708 | /* We can't possibly have debug bind stmts before lowering, we |
709 | first emit them when entering SSA. */ |
710 | gcc_checking_assert (gimple_debug_nonbind_marker_p (stmt)); |
711 | /* Propagate fallthruness. */ |
712 | /* If the function (e.g. from PCH) had debug stmts, but they're |
713 | disabled for this compilation, remove them. */ |
714 | if (!MAY_HAVE_DEBUG_MARKER_STMTS) |
715 | gsi_remove (gsi, true); |
716 | else |
717 | gsi_next (i: gsi); |
718 | return; |
719 | |
720 | case GIMPLE_OMP_STRUCTURED_BLOCK: |
721 | /* These are supposed to be removed already in OMP lowering. */ |
722 | gcc_unreachable (); |
723 | |
724 | case GIMPLE_NOP: |
725 | case GIMPLE_ASM: |
726 | case GIMPLE_ASSIGN: |
727 | case GIMPLE_PREDICT: |
728 | case GIMPLE_LABEL: |
729 | case GIMPLE_EH_MUST_NOT_THROW: |
730 | case GIMPLE_OMP_FOR: |
731 | case GIMPLE_OMP_SCOPE: |
732 | case GIMPLE_OMP_SECTIONS: |
733 | case GIMPLE_OMP_SECTIONS_SWITCH: |
734 | case GIMPLE_OMP_SECTION: |
735 | case GIMPLE_OMP_SINGLE: |
736 | case GIMPLE_OMP_MASTER: |
737 | case GIMPLE_OMP_MASKED: |
738 | case GIMPLE_OMP_TASKGROUP: |
739 | case GIMPLE_OMP_ORDERED: |
740 | case GIMPLE_OMP_SCAN: |
741 | case GIMPLE_OMP_CRITICAL: |
742 | case GIMPLE_OMP_RETURN: |
743 | case GIMPLE_OMP_ATOMIC_LOAD: |
744 | case GIMPLE_OMP_ATOMIC_STORE: |
745 | case GIMPLE_OMP_CONTINUE: |
746 | break; |
747 | |
748 | case GIMPLE_CALL: |
749 | { |
750 | tree decl = gimple_call_fndecl (gs: stmt); |
751 | unsigned i; |
752 | |
753 | for (i = 0; i < gimple_call_num_args (gs: stmt); i++) |
754 | { |
755 | tree arg = gimple_call_arg (gs: stmt, index: i); |
756 | if (EXPR_P (arg)) |
757 | TREE_SET_BLOCK (arg, data->block); |
758 | } |
759 | |
760 | if (decl |
761 | && fndecl_built_in_p (node: decl, klass: BUILT_IN_NORMAL)) |
762 | { |
763 | if (DECL_FUNCTION_CODE (decl) == BUILT_IN_SETJMP) |
764 | { |
765 | lower_builtin_setjmp (gsi); |
766 | data->cannot_fallthru = false; |
767 | return; |
768 | } |
769 | else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN |
770 | && flag_tree_bit_ccp |
771 | && gimple_builtin_call_types_compatible_p (stmt, decl)) |
772 | { |
773 | lower_builtin_posix_memalign (gsi); |
774 | return; |
775 | } |
776 | else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_ASSUME_ALIGNED |
777 | && !optimize) |
778 | { |
779 | lower_builtin_assume_aligned (gsi); |
780 | data->cannot_fallthru = false; |
781 | gsi_next (i: gsi); |
782 | return; |
783 | } |
784 | } |
785 | |
786 | if (decl && (flags_from_decl_or_type (decl) & ECF_NORETURN)) |
787 | { |
788 | data->cannot_fallthru = true; |
789 | gsi_next (i: gsi); |
790 | return; |
791 | } |
792 | |
793 | /* We delay folding of built calls from gimplification to |
794 | here so the IL is in consistent state for the diagnostic |
795 | machineries job. */ |
796 | if (gimple_call_builtin_p (stmt)) |
797 | fold_stmt (gsi); |
798 | } |
799 | break; |
800 | |
801 | case GIMPLE_OMP_PARALLEL: |
802 | case GIMPLE_OMP_TASK: |
803 | case GIMPLE_OMP_TARGET: |
804 | case GIMPLE_OMP_TEAMS: |
805 | data->cannot_fallthru = false; |
806 | lower_omp_directive (gsi, data); |
807 | data->cannot_fallthru = false; |
808 | return; |
809 | |
810 | case GIMPLE_ASSUME: |
811 | lower_assumption (gsi, data); |
812 | return; |
813 | |
814 | case GIMPLE_TRANSACTION: |
815 | lower_sequence (seq: gimple_transaction_body_ptr ( |
816 | transaction_stmt: as_a <gtransaction *> (p: stmt)), |
817 | data); |
818 | break; |
819 | |
820 | default: |
821 | gcc_unreachable (); |
822 | } |
823 | |
824 | data->cannot_fallthru = false; |
825 | gsi_next (i: gsi); |
826 | } |
827 | |
828 | /* Lower a bind_expr TSI. DATA is passed through the recursion. */ |
829 | |
830 | static void |
831 | lower_gimple_bind (gimple_stmt_iterator *gsi, struct lower_data *data) |
832 | { |
833 | tree old_block = data->block; |
834 | gbind *stmt = as_a <gbind *> (p: gsi_stmt (i: *gsi)); |
835 | tree new_block = gimple_bind_block (bind_stmt: stmt); |
836 | |
837 | if (new_block) |
838 | { |
839 | if (new_block == old_block) |
840 | { |
841 | /* The outermost block of the original function may not be the |
842 | outermost statement chain of the gimplified function. So we |
843 | may see the outermost block just inside the function. */ |
844 | gcc_assert (new_block == DECL_INITIAL (current_function_decl)); |
845 | new_block = NULL; |
846 | } |
847 | else |
848 | { |
849 | /* We do not expect to handle duplicate blocks. */ |
850 | gcc_assert (!TREE_ASM_WRITTEN (new_block)); |
851 | TREE_ASM_WRITTEN (new_block) = 1; |
852 | |
853 | /* Block tree may get clobbered by inlining. Normally this would |
854 | be fixed in rest_of_decl_compilation using block notes, but |
855 | since we are not going to emit them, it is up to us. */ |
856 | BLOCK_CHAIN (new_block) = BLOCK_SUBBLOCKS (old_block); |
857 | BLOCK_SUBBLOCKS (old_block) = new_block; |
858 | BLOCK_SUBBLOCKS (new_block) = NULL_TREE; |
859 | BLOCK_SUPERCONTEXT (new_block) = old_block; |
860 | |
861 | data->block = new_block; |
862 | } |
863 | } |
864 | |
865 | record_vars (gimple_bind_vars (bind_stmt: stmt)); |
866 | |
867 | /* Scrap DECL_CHAIN up to BLOCK_VARS to ease GC after we no longer |
868 | need gimple_bind_vars. */ |
869 | tree next; |
870 | /* BLOCK_VARS and gimple_bind_vars share a common sub-chain. Find |
871 | it by marking all BLOCK_VARS. */ |
872 | if (gimple_bind_block (bind_stmt: stmt)) |
873 | for (tree t = BLOCK_VARS (gimple_bind_block (stmt)); t; t = DECL_CHAIN (t)) |
874 | TREE_VISITED (t) = 1; |
875 | for (tree var = gimple_bind_vars (bind_stmt: stmt); |
876 | var && ! TREE_VISITED (var); var = next) |
877 | { |
878 | next = DECL_CHAIN (var); |
879 | DECL_CHAIN (var) = NULL_TREE; |
880 | } |
881 | /* Unmark BLOCK_VARS. */ |
882 | if (gimple_bind_block (bind_stmt: stmt)) |
883 | for (tree t = BLOCK_VARS (gimple_bind_block (stmt)); t; t = DECL_CHAIN (t)) |
884 | TREE_VISITED (t) = 0; |
885 | |
886 | lower_sequence (seq: gimple_bind_body_ptr (bind_stmt: stmt), data); |
887 | |
888 | if (new_block) |
889 | { |
890 | gcc_assert (data->block == new_block); |
891 | |
892 | BLOCK_SUBBLOCKS (new_block) |
893 | = blocks_nreverse (BLOCK_SUBBLOCKS (new_block)); |
894 | data->block = old_block; |
895 | } |
896 | |
897 | /* The GIMPLE_BIND no longer carries any useful information -- kill it. */ |
898 | gsi_insert_seq_before (gsi, gimple_bind_body (gs: stmt), GSI_SAME_STMT); |
899 | gsi_remove (gsi, false); |
900 | } |
901 | |
902 | /* Same as above, but for a GIMPLE_TRY_CATCH. */ |
903 | |
904 | static void |
905 | lower_try_catch (gimple_stmt_iterator *gsi, struct lower_data *data) |
906 | { |
907 | bool cannot_fallthru; |
908 | gimple *stmt = gsi_stmt (i: *gsi); |
909 | gimple_stmt_iterator i; |
910 | |
911 | /* We don't handle GIMPLE_TRY_FINALLY. */ |
912 | gcc_assert (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH); |
913 | |
914 | lower_sequence (seq: gimple_try_eval_ptr (gs: stmt), data); |
915 | cannot_fallthru = data->cannot_fallthru; |
916 | |
917 | i = gsi_start (seq&: *gimple_try_cleanup_ptr (gs: stmt)); |
918 | switch (gimple_code (g: gsi_stmt (i))) |
919 | { |
920 | case GIMPLE_CATCH: |
921 | /* We expect to see a sequence of GIMPLE_CATCH stmts, each with a |
922 | catch expression and a body. The whole try/catch may fall |
923 | through iff any of the catch bodies falls through. */ |
924 | for (; !gsi_end_p (i); gsi_next (i: &i)) |
925 | { |
926 | data->cannot_fallthru = false; |
927 | lower_sequence (seq: gimple_catch_handler_ptr ( |
928 | catch_stmt: as_a <gcatch *> (p: gsi_stmt (i))), |
929 | data); |
930 | if (!data->cannot_fallthru) |
931 | cannot_fallthru = false; |
932 | } |
933 | break; |
934 | |
935 | case GIMPLE_EH_FILTER: |
936 | /* The exception filter expression only matters if there is an |
937 | exception. If the exception does not match EH_FILTER_TYPES, |
938 | we will execute EH_FILTER_FAILURE, and we will fall through |
939 | if that falls through. If the exception does match |
940 | EH_FILTER_TYPES, the stack unwinder will continue up the |
941 | stack, so we will not fall through. We don't know whether we |
942 | will throw an exception which matches EH_FILTER_TYPES or not, |
943 | so we just ignore EH_FILTER_TYPES and assume that we might |
944 | throw an exception which doesn't match. */ |
945 | data->cannot_fallthru = false; |
946 | lower_sequence (seq: gimple_eh_filter_failure_ptr (gs: gsi_stmt (i)), data); |
947 | if (!data->cannot_fallthru) |
948 | cannot_fallthru = false; |
949 | break; |
950 | |
951 | case GIMPLE_DEBUG: |
952 | gcc_checking_assert (gimple_debug_begin_stmt_p (stmt)); |
953 | break; |
954 | |
955 | default: |
956 | /* This case represents statements to be executed when an |
957 | exception occurs. Those statements are implicitly followed |
958 | by a GIMPLE_RESX to resume execution after the exception. So |
959 | in this case the try/catch never falls through. */ |
960 | data->cannot_fallthru = false; |
961 | lower_sequence (seq: gimple_try_cleanup_ptr (gs: stmt), data); |
962 | break; |
963 | } |
964 | |
965 | data->cannot_fallthru = cannot_fallthru; |
966 | gsi_next (i: gsi); |
967 | } |
968 | |
969 | |
970 | /* Try to determine whether a TRY_CATCH expression can fall through. |
971 | This is a subroutine of gimple_stmt_may_fallthru. */ |
972 | |
973 | static bool |
974 | gimple_try_catch_may_fallthru (gtry *stmt) |
975 | { |
976 | gimple_stmt_iterator i; |
977 | |
978 | /* We don't handle GIMPLE_TRY_FINALLY. */ |
979 | gcc_assert (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH); |
980 | |
981 | /* If the TRY block can fall through, the whole TRY_CATCH can |
982 | fall through. */ |
983 | if (gimple_seq_may_fallthru (gimple_try_eval (gs: stmt))) |
984 | return true; |
985 | |
986 | i = gsi_start (seq&: *gimple_try_cleanup_ptr (gs: stmt)); |
987 | switch (gimple_code (g: gsi_stmt (i))) |
988 | { |
989 | case GIMPLE_CATCH: |
990 | /* We expect to see a sequence of GIMPLE_CATCH stmts, each with a |
991 | catch expression and a body. The whole try/catch may fall |
992 | through iff any of the catch bodies falls through. */ |
993 | for (; !gsi_end_p (i); gsi_next (i: &i)) |
994 | { |
995 | if (gimple_seq_may_fallthru (gimple_catch_handler ( |
996 | catch_stmt: as_a <gcatch *> (p: gsi_stmt (i))))) |
997 | return true; |
998 | } |
999 | return false; |
1000 | |
1001 | case GIMPLE_EH_FILTER: |
1002 | /* The exception filter expression only matters if there is an |
1003 | exception. If the exception does not match EH_FILTER_TYPES, |
1004 | we will execute EH_FILTER_FAILURE, and we will fall through |
1005 | if that falls through. If the exception does match |
1006 | EH_FILTER_TYPES, the stack unwinder will continue up the |
1007 | stack, so we will not fall through. We don't know whether we |
1008 | will throw an exception which matches EH_FILTER_TYPES or not, |
1009 | so we just ignore EH_FILTER_TYPES and assume that we might |
1010 | throw an exception which doesn't match. */ |
1011 | return gimple_seq_may_fallthru (gimple_eh_filter_failure (gs: gsi_stmt (i))); |
1012 | |
1013 | default: |
1014 | /* This case represents statements to be executed when an |
1015 | exception occurs. Those statements are implicitly followed |
1016 | by a GIMPLE_RESX to resume execution after the exception. So |
1017 | in this case the try/catch never falls through. */ |
1018 | return false; |
1019 | } |
1020 | } |
1021 | |
1022 | |
1023 | /* Try to determine if we can continue executing the statement |
1024 | immediately following STMT. This guess need not be 100% accurate; |
1025 | simply be conservative and return true if we don't know. This is |
1026 | used only to avoid stupidly generating extra code. If we're wrong, |
1027 | we'll just delete the extra code later. */ |
1028 | |
1029 | bool |
1030 | gimple_stmt_may_fallthru (gimple *stmt) |
1031 | { |
1032 | if (!stmt) |
1033 | return true; |
1034 | |
1035 | switch (gimple_code (g: stmt)) |
1036 | { |
1037 | case GIMPLE_GOTO: |
1038 | case GIMPLE_RETURN: |
1039 | case GIMPLE_RESX: |
1040 | /* Easy cases. If the last statement of the seq implies |
1041 | control transfer, then we can't fall through. */ |
1042 | return false; |
1043 | |
1044 | case GIMPLE_SWITCH: |
1045 | /* Switch has already been lowered and represents a branch |
1046 | to a selected label and hence can't fall through. */ |
1047 | return false; |
1048 | |
1049 | case GIMPLE_COND: |
1050 | /* GIMPLE_COND's are already lowered into a two-way branch. They |
1051 | can't fall through. */ |
1052 | return false; |
1053 | |
1054 | case GIMPLE_BIND: |
1055 | return gimple_seq_may_fallthru ( |
1056 | gimple_bind_body (gs: as_a <gbind *> (p: stmt))); |
1057 | |
1058 | case GIMPLE_TRY: |
1059 | if (gimple_try_kind (gs: stmt) == GIMPLE_TRY_CATCH) |
1060 | return gimple_try_catch_may_fallthru (stmt: as_a <gtry *> (p: stmt)); |
1061 | |
1062 | /* It must be a GIMPLE_TRY_FINALLY. */ |
1063 | |
1064 | /* The finally clause is always executed after the try clause, |
1065 | so if it does not fall through, then the try-finally will not |
1066 | fall through. Otherwise, if the try clause does not fall |
1067 | through, then when the finally clause falls through it will |
1068 | resume execution wherever the try clause was going. So the |
1069 | whole try-finally will only fall through if both the try |
1070 | clause and the finally clause fall through. */ |
1071 | return (gimple_seq_may_fallthru (gimple_try_eval (gs: stmt)) |
1072 | && gimple_seq_may_fallthru (gimple_try_cleanup (gs: stmt))); |
1073 | |
1074 | case GIMPLE_EH_ELSE: |
1075 | { |
1076 | geh_else *eh_else_stmt = as_a <geh_else *> (p: stmt); |
1077 | return (gimple_seq_may_fallthru (gimple_eh_else_n_body (eh_else_stmt)) |
1078 | || gimple_seq_may_fallthru (gimple_eh_else_e_body ( |
1079 | eh_else_stmt))); |
1080 | } |
1081 | |
1082 | case GIMPLE_CALL: |
1083 | /* Functions that do not return do not fall through. */ |
1084 | return !gimple_call_noreturn_p (s: stmt); |
1085 | |
1086 | default: |
1087 | return true; |
1088 | } |
1089 | } |
1090 | |
1091 | |
1092 | /* Same as gimple_stmt_may_fallthru, but for the gimple sequence SEQ. */ |
1093 | |
1094 | bool |
1095 | gimple_seq_may_fallthru (gimple_seq seq) |
1096 | { |
1097 | return gimple_stmt_may_fallthru (stmt: gimple_seq_last_nondebug_stmt (s: seq)); |
1098 | } |
1099 | |
1100 | |
1101 | /* Lower a GIMPLE_RETURN GSI. DATA is passed through the recursion. */ |
1102 | |
1103 | static void |
1104 | lower_gimple_return (gimple_stmt_iterator *gsi, struct lower_data *data) |
1105 | { |
1106 | greturn *stmt = as_a <greturn *> (p: gsi_stmt (i: *gsi)); |
1107 | gimple *t; |
1108 | int i; |
1109 | return_statements_t tmp_rs; |
1110 | |
1111 | /* Match this up with an existing return statement that's been created. */ |
1112 | for (i = data->return_statements.length () - 1; |
1113 | i >= 0; i--) |
1114 | { |
1115 | tmp_rs = data->return_statements[i]; |
1116 | |
1117 | if (gimple_return_retval (gs: stmt) == gimple_return_retval (gs: tmp_rs.stmt)) |
1118 | { |
1119 | /* Remove the line number from the representative return statement. |
1120 | It now fills in for many such returns. Failure to remove this |
1121 | will result in incorrect results for coverage analysis. */ |
1122 | gimple_set_location (g: tmp_rs.stmt, UNKNOWN_LOCATION); |
1123 | |
1124 | goto found; |
1125 | } |
1126 | } |
1127 | |
1128 | /* Not found. Create a new label and record the return statement. */ |
1129 | tmp_rs.label = create_artificial_label (cfun->function_end_locus); |
1130 | tmp_rs.stmt = stmt; |
1131 | data->return_statements.safe_push (obj: tmp_rs); |
1132 | |
1133 | /* Generate a goto statement and remove the return statement. */ |
1134 | found: |
1135 | /* When not optimizing, make sure user returns are preserved. */ |
1136 | if (!optimize && gimple_has_location (g: stmt)) |
1137 | DECL_ARTIFICIAL (tmp_rs.label) = 0; |
1138 | t = gimple_build_goto (dest: tmp_rs.label); |
1139 | /* location includes block. */ |
1140 | gimple_set_location (g: t, location: gimple_location (g: stmt)); |
1141 | gsi_insert_before (gsi, t, GSI_SAME_STMT); |
1142 | gsi_remove (gsi, false); |
1143 | } |
1144 | |
1145 | /* Lower a __builtin_setjmp GSI. |
1146 | |
1147 | __builtin_setjmp is passed a pointer to an array of five words (not |
1148 | all will be used on all machines). It operates similarly to the C |
1149 | library function of the same name, but is more efficient. |
1150 | |
1151 | It is lowered into 2 other builtins, namely __builtin_setjmp_setup, |
1152 | __builtin_setjmp_receiver. |
1153 | |
1154 | After full lowering, the body of the function should look like: |
1155 | |
1156 | { |
1157 | int D.1844; |
1158 | int D.2844; |
1159 | |
1160 | [...] |
1161 | |
1162 | __builtin_setjmp_setup (&buf, &<D1847>); |
1163 | D.1844 = 0; |
1164 | goto <D1846>; |
1165 | <D1847>:; |
1166 | __builtin_setjmp_receiver (&<D1847>); |
1167 | D.1844 = 1; |
1168 | <D1846>:; |
1169 | if (D.1844 == 0) goto <D1848>; else goto <D1849>; |
1170 | |
1171 | [...] |
1172 | |
1173 | __builtin_setjmp_setup (&buf, &<D2847>); |
1174 | D.2844 = 0; |
1175 | goto <D2846>; |
1176 | <D2847>:; |
1177 | __builtin_setjmp_receiver (&<D2847>); |
1178 | D.2844 = 1; |
1179 | <D2846>:; |
1180 | if (D.2844 == 0) goto <D2848>; else goto <D2849>; |
1181 | |
1182 | [...] |
1183 | |
1184 | <D3850>:; |
1185 | return; |
1186 | } |
1187 | |
1188 | During cfg creation an extra per-function (or per-OpenMP region) |
1189 | block with ABNORMAL_DISPATCHER internal call will be added, unique |
1190 | destination of all the abnormal call edges and the unique source of |
1191 | all the abnormal edges to the receivers, thus keeping the complexity |
1192 | explosion localized. */ |
1193 | |
1194 | static void |
1195 | lower_builtin_setjmp (gimple_stmt_iterator *gsi) |
1196 | { |
1197 | gimple *stmt = gsi_stmt (i: *gsi); |
1198 | location_t loc = gimple_location (g: stmt); |
1199 | tree cont_label = create_artificial_label (loc); |
1200 | tree next_label = create_artificial_label (loc); |
1201 | tree dest, t, arg; |
1202 | gimple *g; |
1203 | |
1204 | /* __builtin_setjmp_{setup,receiver} aren't ECF_RETURNS_TWICE and for RTL |
1205 | these builtins are modelled as non-local label jumps to the label |
1206 | that is passed to these two builtins, so pretend we have a non-local |
1207 | label during GIMPLE passes too. See PR60003. */ |
1208 | cfun->has_nonlocal_label = 1; |
1209 | |
1210 | /* NEXT_LABEL is the label __builtin_longjmp will jump to. Its address is |
1211 | passed to both __builtin_setjmp_setup and __builtin_setjmp_receiver. */ |
1212 | FORCED_LABEL (next_label) = 1; |
1213 | |
1214 | tree orig_dest = dest = gimple_call_lhs (gs: stmt); |
1215 | if (orig_dest && TREE_CODE (orig_dest) == SSA_NAME) |
1216 | dest = create_tmp_reg (TREE_TYPE (orig_dest)); |
1217 | |
1218 | /* Build '__builtin_setjmp_setup (BUF, NEXT_LABEL)' and insert. */ |
1219 | arg = build_addr (next_label); |
1220 | t = builtin_decl_implicit (fncode: BUILT_IN_SETJMP_SETUP); |
1221 | g = gimple_build_call (t, 2, gimple_call_arg (gs: stmt, index: 0), arg); |
1222 | /* location includes block. */ |
1223 | gimple_set_location (g, location: loc); |
1224 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
1225 | |
1226 | /* Build 'DEST = 0' and insert. */ |
1227 | if (dest) |
1228 | { |
1229 | g = gimple_build_assign (dest, build_zero_cst (TREE_TYPE (dest))); |
1230 | gimple_set_location (g, location: loc); |
1231 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
1232 | } |
1233 | |
1234 | /* Build 'goto CONT_LABEL' and insert. */ |
1235 | g = gimple_build_goto (dest: cont_label); |
1236 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
1237 | |
1238 | /* Build 'NEXT_LABEL:' and insert. */ |
1239 | g = gimple_build_label (label: next_label); |
1240 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
1241 | |
1242 | /* Build '__builtin_setjmp_receiver (NEXT_LABEL)' and insert. */ |
1243 | arg = build_addr (next_label); |
1244 | t = builtin_decl_implicit (fncode: BUILT_IN_SETJMP_RECEIVER); |
1245 | g = gimple_build_call (t, 1, arg); |
1246 | gimple_set_location (g, location: loc); |
1247 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
1248 | |
1249 | /* Build 'DEST = 1' and insert. */ |
1250 | if (dest) |
1251 | { |
1252 | g = gimple_build_assign (dest, fold_convert_loc (loc, TREE_TYPE (dest), |
1253 | integer_one_node)); |
1254 | gimple_set_location (g, location: loc); |
1255 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
1256 | } |
1257 | |
1258 | /* Build 'CONT_LABEL:' and insert. */ |
1259 | g = gimple_build_label (label: cont_label); |
1260 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
1261 | |
1262 | /* Build orig_dest = dest if necessary. */ |
1263 | if (dest != orig_dest) |
1264 | { |
1265 | g = gimple_build_assign (orig_dest, dest); |
1266 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
1267 | } |
1268 | |
1269 | /* Remove the call to __builtin_setjmp. */ |
1270 | gsi_remove (gsi, false); |
1271 | } |
1272 | |
1273 | /* Lower calls to posix_memalign to |
1274 | res = posix_memalign (ptr, align, size); |
1275 | if (res == 0) |
1276 | *ptr = __builtin_assume_aligned (*ptr, align); |
1277 | or to |
1278 | void *tem; |
1279 | res = posix_memalign (&tem, align, size); |
1280 | if (res == 0) |
1281 | ptr = __builtin_assume_aligned (tem, align); |
1282 | in case the first argument was &ptr. That way we can get at the |
1283 | alignment of the heap pointer in CCP. */ |
1284 | |
1285 | static void |
1286 | lower_builtin_posix_memalign (gimple_stmt_iterator *gsi) |
1287 | { |
1288 | gimple *stmt, *call = gsi_stmt (i: *gsi); |
1289 | tree pptr = gimple_call_arg (gs: call, index: 0); |
1290 | tree align = gimple_call_arg (gs: call, index: 1); |
1291 | tree res = gimple_call_lhs (gs: call); |
1292 | tree ptr = create_tmp_reg (ptr_type_node); |
1293 | if (TREE_CODE (pptr) == ADDR_EXPR) |
1294 | { |
1295 | tree tem = create_tmp_var (ptr_type_node); |
1296 | TREE_ADDRESSABLE (tem) = 1; |
1297 | gimple_call_set_arg (gs: call, index: 0, build_fold_addr_expr (tem)); |
1298 | stmt = gimple_build_assign (ptr, tem); |
1299 | } |
1300 | else |
1301 | stmt = gimple_build_assign (ptr, |
1302 | fold_build2 (MEM_REF, ptr_type_node, pptr, |
1303 | build_int_cst (ptr_type_node, 0))); |
1304 | if (res == NULL_TREE) |
1305 | { |
1306 | res = create_tmp_reg (integer_type_node); |
1307 | gimple_call_set_lhs (gs: call, lhs: res); |
1308 | } |
1309 | tree align_label = create_artificial_label (UNKNOWN_LOCATION); |
1310 | tree noalign_label = create_artificial_label (UNKNOWN_LOCATION); |
1311 | gimple *cond = gimple_build_cond (EQ_EXPR, res, integer_zero_node, |
1312 | align_label, noalign_label); |
1313 | gsi_insert_after (gsi, cond, GSI_NEW_STMT); |
1314 | gsi_insert_after (gsi, gimple_build_label (label: align_label), GSI_NEW_STMT); |
1315 | gsi_insert_after (gsi, stmt, GSI_NEW_STMT); |
1316 | stmt = gimple_build_call (builtin_decl_implicit (fncode: BUILT_IN_ASSUME_ALIGNED), |
1317 | 2, ptr, align); |
1318 | gimple_call_set_lhs (gs: stmt, lhs: ptr); |
1319 | gsi_insert_after (gsi, stmt, GSI_NEW_STMT); |
1320 | stmt = gimple_build_assign (fold_build2 (MEM_REF, ptr_type_node, pptr, |
1321 | build_int_cst (ptr_type_node, 0)), |
1322 | ptr); |
1323 | gsi_insert_after (gsi, stmt, GSI_NEW_STMT); |
1324 | gsi_insert_after (gsi, gimple_build_label (label: noalign_label), GSI_NEW_STMT); |
1325 | } |
1326 | |
1327 | /* Lower calls to __builtin_assume_aligned when not optimizing. */ |
1328 | |
1329 | static void |
1330 | lower_builtin_assume_aligned (gimple_stmt_iterator *gsi) |
1331 | { |
1332 | gcall *call = as_a <gcall *> (p: gsi_stmt (i: *gsi)); |
1333 | |
1334 | tree lhs = gimple_call_lhs (gs: call); |
1335 | if (!lhs || !POINTER_TYPE_P (TREE_TYPE (lhs)) || TREE_CODE (lhs) != SSA_NAME) |
1336 | return; |
1337 | |
1338 | tree align = gimple_call_arg (gs: call, index: 1); |
1339 | tree misalign = (gimple_call_num_args (gs: call) > 2 |
1340 | ? gimple_call_arg (gs: call, index: 2) : NULL_TREE); |
1341 | if (!tree_fits_uhwi_p (align) |
1342 | || (misalign && !tree_fits_uhwi_p (misalign))) |
1343 | return; |
1344 | |
1345 | unsigned aligni = TREE_INT_CST_LOW (align); |
1346 | unsigned misaligni = misalign ? TREE_INT_CST_LOW (misalign) : 0; |
1347 | if (aligni <= 1 |
1348 | || (aligni & (aligni - 1)) != 0 |
1349 | || (misaligni & ~(aligni - 1)) != 0) |
1350 | return; |
1351 | |
1352 | /* For lowering we simply transfer alignment information to the |
1353 | result and leave the call otherwise unchanged, it will be elided |
1354 | at RTL expansion time. */ |
1355 | ptr_info_def *pi = get_ptr_info (lhs); |
1356 | set_ptr_info_alignment (pi, aligni, misaligni); |
1357 | } |
1358 | |
1359 | |
1360 | /* Record the variables in VARS into function FN. */ |
1361 | |
1362 | void |
1363 | record_vars_into (tree vars, tree fn) |
1364 | { |
1365 | for (; vars; vars = DECL_CHAIN (vars)) |
1366 | { |
1367 | tree var = vars; |
1368 | |
1369 | /* BIND_EXPRs contains also function/type/constant declarations |
1370 | we don't need to care about. */ |
1371 | if (!VAR_P (var)) |
1372 | continue; |
1373 | |
1374 | /* Nothing to do in this case. */ |
1375 | if (DECL_EXTERNAL (var)) |
1376 | continue; |
1377 | |
1378 | /* Record the variable. */ |
1379 | add_local_decl (DECL_STRUCT_FUNCTION (fn), d: var); |
1380 | } |
1381 | } |
1382 | |
1383 | |
1384 | /* Record the variables in VARS into current_function_decl. */ |
1385 | |
1386 | void |
1387 | record_vars (tree vars) |
1388 | { |
1389 | record_vars_into (vars, fn: current_function_decl); |
1390 | } |
1391 | |