]>
Commit | Line | Data |
---|---|---|
726a989a | 1 | /* GIMPLE lowering pass. Converts High GIMPLE into Low GIMPLE. |
6de9cd9a | 2 | |
5624e564 | 3 | Copyright (C) 2003-2015 Free Software Foundation, Inc. |
6de9cd9a DN |
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 | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
6de9cd9a DN |
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 | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
6de9cd9a DN |
20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
c7131fb2 | 24 | #include "backend.h" |
6de9cd9a | 25 | #include "tree.h" |
c7131fb2 AM |
26 | #include "gimple.h" |
27 | #include "hard-reg-set.h" | |
28 | #include "alias.h" | |
40e23961 | 29 | #include "fold-const.h" |
d8a2d370 DN |
30 | #include "tree-nested.h" |
31 | #include "calls.h" | |
2fb9a547 | 32 | #include "internal-fn.h" |
5be5c238 | 33 | #include "gimple-iterator.h" |
726a989a | 34 | #include "tree-iterator.h" |
6de9cd9a | 35 | #include "tree-inline.h" |
6de9cd9a | 36 | #include "flags.h" |
718f9c0f | 37 | #include "diagnostic-core.h" |
6de9cd9a | 38 | #include "tree-pass.h" |
88cd0e88 | 39 | #include "langhooks.h" |
4484a35a | 40 | #include "gimple-low.h" |
1fe37220 | 41 | #include "tree-nested.h" |
6de9cd9a | 42 | |
726a989a RB |
43 | /* The differences between High GIMPLE and Low GIMPLE are the |
44 | following: | |
45 | ||
46 | 1- Lexical scopes are removed (i.e., GIMPLE_BIND disappears). | |
47 | ||
48 | 2- GIMPLE_TRY and GIMPLE_CATCH are converted to abnormal control | |
49 | flow and exception regions are built as an on-the-side region | |
50 | hierarchy (See tree-eh.c:lower_eh_constructs). | |
51 | ||
52 | 3- Multiple identical return statements are grouped into a single | |
53 | return and gotos to the unique return site. */ | |
54 | ||
55 | /* Match a return statement with a label. During lowering, we identify | |
56 | identical return statements and replace duplicates with a jump to | |
57 | the corresponding label. */ | |
58 | struct return_statements_t | |
59 | { | |
60 | tree label; | |
538dd0b7 | 61 | greturn *stmt; |
726a989a RB |
62 | }; |
63 | typedef struct return_statements_t return_statements_t; | |
64 | ||
726a989a | 65 | |
6de9cd9a DN |
66 | struct lower_data |
67 | { | |
68 | /* Block the current statement belongs to. */ | |
69 | tree block; | |
f5a76aea | 70 | |
726a989a | 71 | /* A vector of label and return statements to be moved to the end |
71877985 | 72 | of the function. */ |
9771b263 | 73 | vec<return_statements_t> return_statements; |
4f6c2131 | 74 | |
a141816c EB |
75 | /* True if the current statement cannot fall through. */ |
76 | bool cannot_fallthru; | |
6de9cd9a DN |
77 | }; |
78 | ||
726a989a RB |
79 | static void lower_stmt (gimple_stmt_iterator *, struct lower_data *); |
80 | static void lower_gimple_bind (gimple_stmt_iterator *, struct lower_data *); | |
f778c049 | 81 | static void lower_try_catch (gimple_stmt_iterator *, struct lower_data *); |
726a989a RB |
82 | static void lower_gimple_return (gimple_stmt_iterator *, struct lower_data *); |
83 | static void lower_builtin_setjmp (gimple_stmt_iterator *); | |
831806cb | 84 | static void lower_builtin_posix_memalign (gimple_stmt_iterator *); |
6de9cd9a | 85 | |
726a989a RB |
86 | |
87 | /* Lower the body of current_function_decl from High GIMPLE into Low | |
88 | GIMPLE. */ | |
6de9cd9a | 89 | |
c2924966 | 90 | static unsigned int |
6de9cd9a DN |
91 | lower_function_body (void) |
92 | { | |
93 | struct lower_data data; | |
726a989a RB |
94 | gimple_seq body = gimple_body (current_function_decl); |
95 | gimple_seq lowered_body; | |
96 | gimple_stmt_iterator i; | |
355fe088 TS |
97 | gimple *bind; |
98 | gimple *x; | |
726a989a RB |
99 | |
100 | /* The gimplifier should've left a body of exactly one statement, | |
101 | namely a GIMPLE_BIND. */ | |
102 | gcc_assert (gimple_seq_first (body) == gimple_seq_last (body) | |
103 | && gimple_code (gimple_seq_first_stmt (body)) == GIMPLE_BIND); | |
6de9cd9a | 104 | |
953ff289 | 105 | memset (&data, 0, sizeof (data)); |
6de9cd9a DN |
106 | data.block = DECL_INITIAL (current_function_decl); |
107 | BLOCK_SUBBLOCKS (data.block) = NULL_TREE; | |
108 | BLOCK_CHAIN (data.block) = NULL_TREE; | |
109 | TREE_ASM_WRITTEN (data.block) = 1; | |
9771b263 | 110 | data.return_statements.create (8); |
726a989a RB |
111 | |
112 | bind = gimple_seq_first_stmt (body); | |
113 | lowered_body = NULL; | |
114 | gimple_seq_add_stmt (&lowered_body, bind); | |
115 | i = gsi_start (lowered_body); | |
116 | lower_gimple_bind (&i, &data); | |
6de9cd9a | 117 | |
726a989a | 118 | i = gsi_last (lowered_body); |
ff98621c RH |
119 | |
120 | /* If the function falls off the end, we need a null return statement. | |
726a989a | 121 | If we've already got one in the return_statements vector, we don't |
ff98621c | 122 | need to do anything special. Otherwise build one by hand. */ |
67b69814 EB |
123 | bool may_fallthru = gimple_seq_may_fallthru (lowered_body); |
124 | if (may_fallthru | |
9771b263 | 125 | && (data.return_statements.is_empty () |
c3284718 RS |
126 | || (gimple_return_retval (data.return_statements.last().stmt) |
127 | != NULL))) | |
ff98621c | 128 | { |
726a989a RB |
129 | x = gimple_build_return (NULL); |
130 | gimple_set_location (x, cfun->function_end_locus); | |
cc2a64dd | 131 | gimple_set_block (x, DECL_INITIAL (current_function_decl)); |
726a989a | 132 | gsi_insert_after (&i, x, GSI_CONTINUE_LINKING); |
67b69814 | 133 | may_fallthru = false; |
ff98621c RH |
134 | } |
135 | ||
136 | /* If we lowered any return statements, emit the representative | |
137 | at the end of the function. */ | |
9771b263 | 138 | while (!data.return_statements.is_empty ()) |
f5a76aea | 139 | { |
9771b263 | 140 | return_statements_t t = data.return_statements.pop (); |
726a989a RB |
141 | x = gimple_build_label (t.label); |
142 | gsi_insert_after (&i, x, GSI_CONTINUE_LINKING); | |
726a989a | 143 | gsi_insert_after (&i, t.stmt, GSI_CONTINUE_LINKING); |
67b69814 EB |
144 | if (may_fallthru) |
145 | { | |
146 | /* Remove the line number from the representative return statement. | |
147 | It now fills in for the fallthru too. Failure to remove this | |
148 | will result in incorrect results for coverage analysis. */ | |
149 | gimple_set_location (t.stmt, UNKNOWN_LOCATION); | |
150 | may_fallthru = false; | |
151 | } | |
f5a76aea RH |
152 | } |
153 | ||
355a7673 MM |
154 | /* Once the old body has been lowered, replace it with the new |
155 | lowered sequence. */ | |
156 | gimple_set_body (current_function_decl, lowered_body); | |
157 | ||
282899df | 158 | gcc_assert (data.block == DECL_INITIAL (current_function_decl)); |
6de9cd9a DN |
159 | BLOCK_SUBBLOCKS (data.block) |
160 | = blocks_nreverse (BLOCK_SUBBLOCKS (data.block)); | |
161 | ||
162 | clear_block_marks (data.block); | |
9771b263 | 163 | data.return_statements.release (); |
c2924966 | 164 | return 0; |
6de9cd9a DN |
165 | } |
166 | ||
27a4cd48 DM |
167 | namespace { |
168 | ||
169 | const pass_data pass_data_lower_cf = | |
6de9cd9a | 170 | { |
27a4cd48 DM |
171 | GIMPLE_PASS, /* type */ |
172 | "lower", /* name */ | |
173 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
174 | TV_NONE, /* tv_id */ |
175 | PROP_gimple_any, /* properties_required */ | |
176 | PROP_gimple_lcf, /* properties_provided */ | |
177 | 0, /* properties_destroyed */ | |
178 | 0, /* todo_flags_start */ | |
179 | 0, /* todo_flags_finish */ | |
6de9cd9a DN |
180 | }; |
181 | ||
27a4cd48 DM |
182 | class pass_lower_cf : public gimple_opt_pass |
183 | { | |
184 | public: | |
c3284718 RS |
185 | pass_lower_cf (gcc::context *ctxt) |
186 | : gimple_opt_pass (pass_data_lower_cf, ctxt) | |
27a4cd48 DM |
187 | {} |
188 | ||
189 | /* opt_pass methods: */ | |
be55bfe6 | 190 | virtual unsigned int execute (function *) { return lower_function_body (); } |
27a4cd48 DM |
191 | |
192 | }; // class pass_lower_cf | |
193 | ||
194 | } // anon namespace | |
195 | ||
196 | gimple_opt_pass * | |
197 | make_pass_lower_cf (gcc::context *ctxt) | |
198 | { | |
199 | return new pass_lower_cf (ctxt); | |
200 | } | |
201 | ||
726a989a | 202 | /* Lower sequence SEQ. Unlike gimplification the statements are not relowered |
6de9cd9a DN |
203 | when they are changed -- if this has to be done, the lowering routine must |
204 | do it explicitly. DATA is passed through the recursion. */ | |
205 | ||
1ebf7687 | 206 | static void |
355a7673 | 207 | lower_sequence (gimple_seq *seq, struct lower_data *data) |
6de9cd9a | 208 | { |
726a989a | 209 | gimple_stmt_iterator gsi; |
6de9cd9a | 210 | |
355a7673 | 211 | for (gsi = gsi_start (*seq); !gsi_end_p (gsi); ) |
726a989a | 212 | lower_stmt (&gsi, data); |
6de9cd9a DN |
213 | } |
214 | ||
50674e96 | 215 | |
726a989a | 216 | /* Lower the OpenMP directive statement pointed by GSI. DATA is |
50674e96 DN |
217 | passed through the recursion. */ |
218 | ||
219 | static void | |
726a989a | 220 | lower_omp_directive (gimple_stmt_iterator *gsi, struct lower_data *data) |
50674e96 | 221 | { |
355fe088 | 222 | gimple *stmt; |
b8698a0f | 223 | |
726a989a | 224 | stmt = gsi_stmt (*gsi); |
50674e96 | 225 | |
355a7673 MM |
226 | lower_sequence (gimple_omp_body_ptr (stmt), data); |
227 | gsi_insert_seq_after (gsi, gimple_omp_body (stmt), GSI_CONTINUE_LINKING); | |
726a989a | 228 | gimple_omp_set_body (stmt, NULL); |
355a7673 | 229 | gsi_next (gsi); |
50674e96 DN |
230 | } |
231 | ||
232 | ||
a141816c EB |
233 | /* Lower statement GSI. DATA is passed through the recursion. We try to |
234 | track the fallthruness of statements and get rid of unreachable return | |
235 | statements in order to prevent the EH lowering pass from adding useless | |
236 | edges that can cause bogus warnings to be issued later; this guess need | |
237 | not be 100% accurate, simply be conservative and reset cannot_fallthru | |
238 | to false if we don't know. */ | |
6de9cd9a DN |
239 | |
240 | static void | |
726a989a | 241 | lower_stmt (gimple_stmt_iterator *gsi, struct lower_data *data) |
6de9cd9a | 242 | { |
355fe088 | 243 | gimple *stmt = gsi_stmt (*gsi); |
6de9cd9a | 244 | |
726a989a | 245 | gimple_set_block (stmt, data->block); |
6de9cd9a | 246 | |
726a989a | 247 | switch (gimple_code (stmt)) |
6de9cd9a | 248 | { |
726a989a RB |
249 | case GIMPLE_BIND: |
250 | lower_gimple_bind (gsi, data); | |
a141816c | 251 | /* Propagate fallthruness. */ |
f5a76aea | 252 | return; |
6de9cd9a | 253 | |
726a989a | 254 | case GIMPLE_COND: |
a141816c EB |
255 | case GIMPLE_GOTO: |
256 | case GIMPLE_SWITCH: | |
257 | data->cannot_fallthru = true; | |
258 | gsi_next (gsi); | |
259 | return; | |
726a989a RB |
260 | |
261 | case GIMPLE_RETURN: | |
a141816c EB |
262 | if (data->cannot_fallthru) |
263 | { | |
264 | gsi_remove (gsi, false); | |
265 | /* Propagate fallthruness. */ | |
266 | } | |
267 | else | |
268 | { | |
269 | lower_gimple_return (gsi, data); | |
270 | data->cannot_fallthru = true; | |
271 | } | |
726a989a RB |
272 | return; |
273 | ||
274 | case GIMPLE_TRY: | |
f778c049 EB |
275 | if (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH) |
276 | lower_try_catch (gsi, data); | |
277 | else | |
278 | { | |
279 | /* It must be a GIMPLE_TRY_FINALLY. */ | |
280 | bool cannot_fallthru; | |
281 | lower_sequence (gimple_try_eval_ptr (stmt), data); | |
282 | cannot_fallthru = data->cannot_fallthru; | |
283 | ||
284 | /* The finally clause is always executed after the try clause, | |
285 | so if it does not fall through, then the try-finally will not | |
286 | fall through. Otherwise, if the try clause does not fall | |
287 | through, then when the finally clause falls through it will | |
288 | resume execution wherever the try clause was going. So the | |
289 | whole try-finally will only fall through if both the try | |
290 | clause and the finally clause fall through. */ | |
291 | data->cannot_fallthru = false; | |
292 | lower_sequence (gimple_try_cleanup_ptr (stmt), data); | |
293 | data->cannot_fallthru |= cannot_fallthru; | |
294 | gsi_next (gsi); | |
295 | } | |
296 | return; | |
777f7f9a | 297 | |
0a35513e | 298 | case GIMPLE_EH_ELSE: |
538dd0b7 DM |
299 | { |
300 | geh_else *eh_else_stmt = as_a <geh_else *> (stmt); | |
301 | lower_sequence (gimple_eh_else_n_body_ptr (eh_else_stmt), data); | |
302 | lower_sequence (gimple_eh_else_e_body_ptr (eh_else_stmt), data); | |
303 | } | |
0a35513e AH |
304 | break; |
305 | ||
726a989a RB |
306 | case GIMPLE_NOP: |
307 | case GIMPLE_ASM: | |
308 | case GIMPLE_ASSIGN: | |
726a989a RB |
309 | case GIMPLE_PREDICT: |
310 | case GIMPLE_LABEL: | |
1d65f45c | 311 | case GIMPLE_EH_MUST_NOT_THROW: |
726a989a RB |
312 | case GIMPLE_OMP_FOR: |
313 | case GIMPLE_OMP_SECTIONS: | |
314 | case GIMPLE_OMP_SECTIONS_SWITCH: | |
315 | case GIMPLE_OMP_SECTION: | |
316 | case GIMPLE_OMP_SINGLE: | |
317 | case GIMPLE_OMP_MASTER: | |
acf0174b | 318 | case GIMPLE_OMP_TASKGROUP: |
726a989a RB |
319 | case GIMPLE_OMP_ORDERED: |
320 | case GIMPLE_OMP_CRITICAL: | |
321 | case GIMPLE_OMP_RETURN: | |
322 | case GIMPLE_OMP_ATOMIC_LOAD: | |
323 | case GIMPLE_OMP_ATOMIC_STORE: | |
324 | case GIMPLE_OMP_CONTINUE: | |
325 | break; | |
4f6c2131 | 326 | |
726a989a | 327 | case GIMPLE_CALL: |
4f6c2131 | 328 | { |
726a989a | 329 | tree decl = gimple_call_fndecl (stmt); |
f16dd822 DC |
330 | unsigned i; |
331 | ||
332 | for (i = 0; i < gimple_call_num_args (stmt); i++) | |
333 | { | |
334 | tree arg = gimple_call_arg (stmt, i); | |
335 | if (EXPR_P (arg)) | |
336 | TREE_SET_BLOCK (arg, data->block); | |
337 | } | |
726a989a | 338 | |
4f6c2131 | 339 | if (decl |
831806cb | 340 | && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL) |
4f6c2131 | 341 | { |
831806cb RB |
342 | if (DECL_FUNCTION_CODE (decl) == BUILT_IN_SETJMP) |
343 | { | |
344 | lower_builtin_setjmp (gsi); | |
345 | data->cannot_fallthru = false; | |
346 | return; | |
347 | } | |
c4c8514e | 348 | else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN |
41dd7cf7 MP |
349 | && flag_tree_bit_ccp |
350 | && gimple_builtin_call_types_compatible_p (stmt, decl)) | |
831806cb RB |
351 | { |
352 | lower_builtin_posix_memalign (gsi); | |
353 | return; | |
354 | } | |
4f6c2131 | 355 | } |
79ddec02 | 356 | |
79ddec02 EB |
357 | if (decl && (flags_from_decl_or_type (decl) & ECF_NORETURN)) |
358 | { | |
a141816c | 359 | data->cannot_fallthru = true; |
79ddec02 | 360 | gsi_next (gsi); |
79ddec02 EB |
361 | return; |
362 | } | |
4f6c2131 EB |
363 | } |
364 | break; | |
365 | ||
726a989a RB |
366 | case GIMPLE_OMP_PARALLEL: |
367 | case GIMPLE_OMP_TASK: | |
acf0174b JJ |
368 | case GIMPLE_OMP_TARGET: |
369 | case GIMPLE_OMP_TEAMS: | |
a141816c | 370 | data->cannot_fallthru = false; |
726a989a | 371 | lower_omp_directive (gsi, data); |
a141816c | 372 | data->cannot_fallthru = false; |
50674e96 DN |
373 | return; |
374 | ||
0a35513e | 375 | case GIMPLE_TRANSACTION: |
538dd0b7 DM |
376 | lower_sequence (gimple_transaction_body_ptr ( |
377 | as_a <gtransaction *> (stmt)), | |
378 | data); | |
0a35513e AH |
379 | break; |
380 | ||
6de9cd9a | 381 | default: |
282899df | 382 | gcc_unreachable (); |
6de9cd9a DN |
383 | } |
384 | ||
a141816c | 385 | data->cannot_fallthru = false; |
726a989a | 386 | gsi_next (gsi); |
6de9cd9a DN |
387 | } |
388 | ||
4f6c2131 | 389 | /* Lower a bind_expr TSI. DATA is passed through the recursion. */ |
6de9cd9a DN |
390 | |
391 | static void | |
726a989a | 392 | lower_gimple_bind (gimple_stmt_iterator *gsi, struct lower_data *data) |
6de9cd9a DN |
393 | { |
394 | tree old_block = data->block; | |
538dd0b7 | 395 | gbind *stmt = as_a <gbind *> (gsi_stmt (*gsi)); |
726a989a | 396 | tree new_block = gimple_bind_block (stmt); |
6de9cd9a DN |
397 | |
398 | if (new_block) | |
399 | { | |
400 | if (new_block == old_block) | |
401 | { | |
402 | /* The outermost block of the original function may not be the | |
403 | outermost statement chain of the gimplified function. So we | |
404 | may see the outermost block just inside the function. */ | |
282899df | 405 | gcc_assert (new_block == DECL_INITIAL (current_function_decl)); |
6de9cd9a DN |
406 | new_block = NULL; |
407 | } | |
408 | else | |
409 | { | |
410 | /* We do not expect to handle duplicate blocks. */ | |
282899df | 411 | gcc_assert (!TREE_ASM_WRITTEN (new_block)); |
6de9cd9a DN |
412 | TREE_ASM_WRITTEN (new_block) = 1; |
413 | ||
414 | /* Block tree may get clobbered by inlining. Normally this would | |
415 | be fixed in rest_of_decl_compilation using block notes, but | |
416 | since we are not going to emit them, it is up to us. */ | |
417 | BLOCK_CHAIN (new_block) = BLOCK_SUBBLOCKS (old_block); | |
418 | BLOCK_SUBBLOCKS (old_block) = new_block; | |
419 | BLOCK_SUBBLOCKS (new_block) = NULL_TREE; | |
420 | BLOCK_SUPERCONTEXT (new_block) = old_block; | |
421 | ||
422 | data->block = new_block; | |
423 | } | |
424 | } | |
425 | ||
726a989a | 426 | record_vars (gimple_bind_vars (stmt)); |
355a7673 | 427 | lower_sequence (gimple_bind_body_ptr (stmt), data); |
6de9cd9a DN |
428 | |
429 | if (new_block) | |
430 | { | |
282899df | 431 | gcc_assert (data->block == new_block); |
6de9cd9a DN |
432 | |
433 | BLOCK_SUBBLOCKS (new_block) | |
434 | = blocks_nreverse (BLOCK_SUBBLOCKS (new_block)); | |
435 | data->block = old_block; | |
436 | } | |
437 | ||
726a989a RB |
438 | /* The GIMPLE_BIND no longer carries any useful information -- kill it. */ |
439 | gsi_insert_seq_before (gsi, gimple_bind_body (stmt), GSI_SAME_STMT); | |
440 | gsi_remove (gsi, false); | |
6de9cd9a DN |
441 | } |
442 | ||
f778c049 EB |
443 | /* Same as above, but for a GIMPLE_TRY_CATCH. */ |
444 | ||
445 | static void | |
446 | lower_try_catch (gimple_stmt_iterator *gsi, struct lower_data *data) | |
447 | { | |
448 | bool cannot_fallthru; | |
355fe088 | 449 | gimple *stmt = gsi_stmt (*gsi); |
f778c049 EB |
450 | gimple_stmt_iterator i; |
451 | ||
452 | /* We don't handle GIMPLE_TRY_FINALLY. */ | |
453 | gcc_assert (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH); | |
454 | ||
455 | lower_sequence (gimple_try_eval_ptr (stmt), data); | |
456 | cannot_fallthru = data->cannot_fallthru; | |
457 | ||
458 | i = gsi_start (*gimple_try_cleanup_ptr (stmt)); | |
459 | switch (gimple_code (gsi_stmt (i))) | |
460 | { | |
461 | case GIMPLE_CATCH: | |
462 | /* We expect to see a sequence of GIMPLE_CATCH stmts, each with a | |
463 | catch expression and a body. The whole try/catch may fall | |
464 | through iff any of the catch bodies falls through. */ | |
465 | for (; !gsi_end_p (i); gsi_next (&i)) | |
466 | { | |
467 | data->cannot_fallthru = false; | |
538dd0b7 DM |
468 | lower_sequence (gimple_catch_handler_ptr ( |
469 | as_a <gcatch *> (gsi_stmt (i))), | |
470 | data); | |
f778c049 EB |
471 | if (!data->cannot_fallthru) |
472 | cannot_fallthru = false; | |
473 | } | |
474 | break; | |
475 | ||
476 | case GIMPLE_EH_FILTER: | |
477 | /* The exception filter expression only matters if there is an | |
478 | exception. If the exception does not match EH_FILTER_TYPES, | |
479 | we will execute EH_FILTER_FAILURE, and we will fall through | |
480 | if that falls through. If the exception does match | |
481 | EH_FILTER_TYPES, the stack unwinder will continue up the | |
482 | stack, so we will not fall through. We don't know whether we | |
483 | will throw an exception which matches EH_FILTER_TYPES or not, | |
484 | so we just ignore EH_FILTER_TYPES and assume that we might | |
485 | throw an exception which doesn't match. */ | |
486 | data->cannot_fallthru = false; | |
487 | lower_sequence (gimple_eh_filter_failure_ptr (gsi_stmt (i)), data); | |
488 | if (!data->cannot_fallthru) | |
489 | cannot_fallthru = false; | |
490 | break; | |
491 | ||
492 | default: | |
493 | /* This case represents statements to be executed when an | |
494 | exception occurs. Those statements are implicitly followed | |
495 | by a GIMPLE_RESX to resume execution after the exception. So | |
496 | in this case the try/catch never falls through. */ | |
497 | data->cannot_fallthru = false; | |
498 | lower_sequence (gimple_try_cleanup_ptr (stmt), data); | |
499 | break; | |
500 | } | |
501 | ||
502 | data->cannot_fallthru = cannot_fallthru; | |
503 | gsi_next (gsi); | |
504 | } | |
505 | ||
6737ba67 | 506 | |
cf2d1b38 AM |
507 | /* Try to determine whether a TRY_CATCH expression can fall through. |
508 | This is a subroutine of gimple_stmt_may_fallthru. */ | |
726a989a RB |
509 | |
510 | static bool | |
538dd0b7 | 511 | gimple_try_catch_may_fallthru (gtry *stmt) |
726a989a RB |
512 | { |
513 | gimple_stmt_iterator i; | |
514 | ||
515 | /* We don't handle GIMPLE_TRY_FINALLY. */ | |
516 | gcc_assert (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH); | |
517 | ||
518 | /* If the TRY block can fall through, the whole TRY_CATCH can | |
519 | fall through. */ | |
520 | if (gimple_seq_may_fallthru (gimple_try_eval (stmt))) | |
521 | return true; | |
522 | ||
355a7673 | 523 | i = gsi_start (*gimple_try_cleanup_ptr (stmt)); |
726a989a RB |
524 | switch (gimple_code (gsi_stmt (i))) |
525 | { | |
526 | case GIMPLE_CATCH: | |
527 | /* We expect to see a sequence of GIMPLE_CATCH stmts, each with a | |
528 | catch expression and a body. The whole try/catch may fall | |
529 | through iff any of the catch bodies falls through. */ | |
530 | for (; !gsi_end_p (i); gsi_next (&i)) | |
531 | { | |
538dd0b7 DM |
532 | if (gimple_seq_may_fallthru (gimple_catch_handler ( |
533 | as_a <gcatch *> (gsi_stmt (i))))) | |
726a989a RB |
534 | return true; |
535 | } | |
536 | return false; | |
537 | ||
538 | case GIMPLE_EH_FILTER: | |
539 | /* The exception filter expression only matters if there is an | |
540 | exception. If the exception does not match EH_FILTER_TYPES, | |
541 | we will execute EH_FILTER_FAILURE, and we will fall through | |
542 | if that falls through. If the exception does match | |
543 | EH_FILTER_TYPES, the stack unwinder will continue up the | |
544 | stack, so we will not fall through. We don't know whether we | |
545 | will throw an exception which matches EH_FILTER_TYPES or not, | |
546 | so we just ignore EH_FILTER_TYPES and assume that we might | |
547 | throw an exception which doesn't match. */ | |
548 | return gimple_seq_may_fallthru (gimple_eh_filter_failure (gsi_stmt (i))); | |
549 | ||
550 | default: | |
551 | /* This case represents statements to be executed when an | |
552 | exception occurs. Those statements are implicitly followed | |
553 | by a GIMPLE_RESX to resume execution after the exception. So | |
554 | in this case the try/catch never falls through. */ | |
555 | return false; | |
556 | } | |
557 | } | |
558 | ||
559 | ||
726a989a RB |
560 | /* Try to determine if we can continue executing the statement |
561 | immediately following STMT. This guess need not be 100% accurate; | |
562 | simply be conservative and return true if we don't know. This is | |
563 | used only to avoid stupidly generating extra code. If we're wrong, | |
564 | we'll just delete the extra code later. */ | |
565 | ||
566 | bool | |
355fe088 | 567 | gimple_stmt_may_fallthru (gimple *stmt) |
6de9cd9a | 568 | { |
726a989a RB |
569 | if (!stmt) |
570 | return true; | |
6de9cd9a | 571 | |
726a989a RB |
572 | switch (gimple_code (stmt)) |
573 | { | |
574 | case GIMPLE_GOTO: | |
575 | case GIMPLE_RETURN: | |
576 | case GIMPLE_RESX: | |
b8698a0f | 577 | /* Easy cases. If the last statement of the seq implies |
726a989a RB |
578 | control transfer, then we can't fall through. */ |
579 | return false; | |
6de9cd9a | 580 | |
726a989a | 581 | case GIMPLE_SWITCH: |
a141816c EB |
582 | /* Switch has already been lowered and represents a branch |
583 | to a selected label and hence can't fall through. */ | |
584 | return false; | |
6de9cd9a | 585 | |
726a989a RB |
586 | case GIMPLE_COND: |
587 | /* GIMPLE_COND's are already lowered into a two-way branch. They | |
588 | can't fall through. */ | |
589 | return false; | |
6de9cd9a | 590 | |
726a989a | 591 | case GIMPLE_BIND: |
538dd0b7 DM |
592 | return gimple_seq_may_fallthru ( |
593 | gimple_bind_body (as_a <gbind *> (stmt))); | |
6de9cd9a | 594 | |
726a989a RB |
595 | case GIMPLE_TRY: |
596 | if (gimple_try_kind (stmt) == GIMPLE_TRY_CATCH) | |
538dd0b7 | 597 | return gimple_try_catch_may_fallthru (as_a <gtry *> (stmt)); |
6de9cd9a | 598 | |
726a989a | 599 | /* It must be a GIMPLE_TRY_FINALLY. */ |
6de9cd9a | 600 | |
726a989a RB |
601 | /* The finally clause is always executed after the try clause, |
602 | so if it does not fall through, then the try-finally will not | |
603 | fall through. Otherwise, if the try clause does not fall | |
604 | through, then when the finally clause falls through it will | |
605 | resume execution wherever the try clause was going. So the | |
606 | whole try-finally will only fall through if both the try | |
607 | clause and the finally clause fall through. */ | |
608 | return (gimple_seq_may_fallthru (gimple_try_eval (stmt)) | |
609 | && gimple_seq_may_fallthru (gimple_try_cleanup (stmt))); | |
610 | ||
0a35513e | 611 | case GIMPLE_EH_ELSE: |
538dd0b7 DM |
612 | { |
613 | geh_else *eh_else_stmt = as_a <geh_else *> (stmt); | |
614 | return (gimple_seq_may_fallthru (gimple_eh_else_n_body (eh_else_stmt)) | |
615 | || gimple_seq_may_fallthru (gimple_eh_else_e_body ( | |
616 | eh_else_stmt))); | |
617 | } | |
0a35513e | 618 | |
726a989a RB |
619 | case GIMPLE_CALL: |
620 | /* Functions that do not return do not fall through. */ | |
621 | return (gimple_call_flags (stmt) & ECF_NORETURN) == 0; | |
a141816c | 622 | |
726a989a RB |
623 | default: |
624 | return true; | |
6de9cd9a | 625 | } |
726a989a RB |
626 | } |
627 | ||
6de9cd9a | 628 | |
726a989a | 629 | /* Same as gimple_stmt_may_fallthru, but for the gimple sequence SEQ. */ |
6de9cd9a | 630 | |
726a989a RB |
631 | bool |
632 | gimple_seq_may_fallthru (gimple_seq seq) | |
633 | { | |
634 | return gimple_stmt_may_fallthru (gimple_seq_last_stmt (seq)); | |
6de9cd9a | 635 | } |
f5a76aea | 636 | |
726a989a RB |
637 | |
638 | /* Lower a GIMPLE_RETURN GSI. DATA is passed through the recursion. */ | |
4f6c2131 | 639 | |
f5a76aea | 640 | static void |
726a989a | 641 | lower_gimple_return (gimple_stmt_iterator *gsi, struct lower_data *data) |
f5a76aea | 642 | { |
538dd0b7 | 643 | greturn *stmt = as_a <greturn *> (gsi_stmt (*gsi)); |
355fe088 | 644 | gimple *t; |
726a989a RB |
645 | int i; |
646 | return_statements_t tmp_rs; | |
f5a76aea | 647 | |
71877985 | 648 | /* Match this up with an existing return statement that's been created. */ |
9771b263 | 649 | for (i = data->return_statements.length () - 1; |
726a989a | 650 | i >= 0; i--) |
f5a76aea | 651 | { |
9771b263 | 652 | tmp_rs = data->return_statements[i]; |
71877985 | 653 | |
726a989a | 654 | if (gimple_return_retval (stmt) == gimple_return_retval (tmp_rs.stmt)) |
0efb9d64 AK |
655 | { |
656 | /* Remove the line number from the representative return statement. | |
657 | It now fills in for many such returns. Failure to remove this | |
658 | will result in incorrect results for coverage analysis. */ | |
659 | gimple_set_location (tmp_rs.stmt, UNKNOWN_LOCATION); | |
660 | ||
661 | goto found; | |
662 | } | |
f5a76aea RH |
663 | } |
664 | ||
71877985 | 665 | /* Not found. Create a new label and record the return statement. */ |
c2255bc4 | 666 | tmp_rs.label = create_artificial_label (cfun->function_end_locus); |
726a989a | 667 | tmp_rs.stmt = stmt; |
9771b263 | 668 | data->return_statements.safe_push (tmp_rs); |
71877985 RH |
669 | |
670 | /* Generate a goto statement and remove the return statement. */ | |
671 | found: | |
516426da EB |
672 | /* When not optimizing, make sure user returns are preserved. */ |
673 | if (!optimize && gimple_has_location (stmt)) | |
674 | DECL_ARTIFICIAL (tmp_rs.label) = 0; | |
726a989a RB |
675 | t = gimple_build_goto (tmp_rs.label); |
676 | gimple_set_location (t, gimple_location (stmt)); | |
cc2a64dd | 677 | gimple_set_block (t, gimple_block (stmt)); |
726a989a RB |
678 | gsi_insert_before (gsi, t, GSI_SAME_STMT); |
679 | gsi_remove (gsi, false); | |
4f6c2131 EB |
680 | } |
681 | ||
a141816c | 682 | /* Lower a __builtin_setjmp GSI. |
4f6c2131 EB |
683 | |
684 | __builtin_setjmp is passed a pointer to an array of five words (not | |
685 | all will be used on all machines). It operates similarly to the C | |
686 | library function of the same name, but is more efficient. | |
687 | ||
09b22f48 JJ |
688 | It is lowered into 2 other builtins, namely __builtin_setjmp_setup, |
689 | __builtin_setjmp_receiver. | |
4f6c2131 EB |
690 | |
691 | After full lowering, the body of the function should look like: | |
692 | ||
693 | { | |
4f6c2131 EB |
694 | int D.1844; |
695 | int D.2844; | |
696 | ||
697 | [...] | |
698 | ||
699 | __builtin_setjmp_setup (&buf, &<D1847>); | |
700 | D.1844 = 0; | |
701 | goto <D1846>; | |
702 | <D1847>:; | |
703 | __builtin_setjmp_receiver (&<D1847>); | |
704 | D.1844 = 1; | |
705 | <D1846>:; | |
706 | if (D.1844 == 0) goto <D1848>; else goto <D1849>; | |
707 | ||
708 | [...] | |
709 | ||
710 | __builtin_setjmp_setup (&buf, &<D2847>); | |
711 | D.2844 = 0; | |
712 | goto <D2846>; | |
713 | <D2847>:; | |
714 | __builtin_setjmp_receiver (&<D2847>); | |
715 | D.2844 = 1; | |
716 | <D2846>:; | |
717 | if (D.2844 == 0) goto <D2848>; else goto <D2849>; | |
718 | ||
719 | [...] | |
720 | ||
721 | <D3850>:; | |
722 | return; | |
4f6c2131 EB |
723 | } |
724 | ||
09b22f48 JJ |
725 | During cfg creation an extra per-function (or per-OpenMP region) |
726 | block with ABNORMAL_DISPATCHER internal call will be added, unique | |
727 | destination of all the abnormal call edges and the unique source of | |
728 | all the abnormal edges to the receivers, thus keeping the complexity | |
729 | explosion localized. */ | |
4f6c2131 EB |
730 | |
731 | static void | |
726a989a | 732 | lower_builtin_setjmp (gimple_stmt_iterator *gsi) |
4f6c2131 | 733 | { |
355fe088 | 734 | gimple *stmt = gsi_stmt (*gsi); |
c2255bc4 AH |
735 | location_t loc = gimple_location (stmt); |
736 | tree cont_label = create_artificial_label (loc); | |
737 | tree next_label = create_artificial_label (loc); | |
4f6c2131 | 738 | tree dest, t, arg; |
355fe088 | 739 | gimple *g; |
4f6c2131 | 740 | |
021293cb JJ |
741 | /* __builtin_setjmp_{setup,receiver} aren't ECF_RETURNS_TWICE and for RTL |
742 | these builtins are modelled as non-local label jumps to the label | |
743 | that is passed to these two builtins, so pretend we have a non-local | |
744 | label during GIMPLE passes too. See PR60003. */ | |
d764963b | 745 | cfun->has_nonlocal_label = 1; |
021293cb | 746 | |
4f6c2131 EB |
747 | /* NEXT_LABEL is the label __builtin_longjmp will jump to. Its address is |
748 | passed to both __builtin_setjmp_setup and __builtin_setjmp_receiver. */ | |
749 | FORCED_LABEL (next_label) = 1; | |
750 | ||
726a989a | 751 | dest = gimple_call_lhs (stmt); |
4f6c2131 EB |
752 | |
753 | /* Build '__builtin_setjmp_setup (BUF, NEXT_LABEL)' and insert. */ | |
5039610b | 754 | arg = build_addr (next_label, current_function_decl); |
e79983f4 | 755 | t = builtin_decl_implicit (BUILT_IN_SETJMP_SETUP); |
726a989a | 756 | g = gimple_build_call (t, 2, gimple_call_arg (stmt, 0), arg); |
db3927fb | 757 | gimple_set_location (g, loc); |
cc2a64dd | 758 | gimple_set_block (g, gimple_block (stmt)); |
726a989a | 759 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
4f6c2131 EB |
760 | |
761 | /* Build 'DEST = 0' and insert. */ | |
762 | if (dest) | |
763 | { | |
e8160c9a | 764 | g = gimple_build_assign (dest, build_zero_cst (TREE_TYPE (dest))); |
db3927fb | 765 | gimple_set_location (g, loc); |
cc2a64dd | 766 | gimple_set_block (g, gimple_block (stmt)); |
726a989a | 767 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
4f6c2131 EB |
768 | } |
769 | ||
770 | /* Build 'goto CONT_LABEL' and insert. */ | |
726a989a | 771 | g = gimple_build_goto (cont_label); |
bbbbb16a | 772 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
4f6c2131 EB |
773 | |
774 | /* Build 'NEXT_LABEL:' and insert. */ | |
726a989a RB |
775 | g = gimple_build_label (next_label); |
776 | gsi_insert_before (gsi, g, GSI_SAME_STMT); | |
4f6c2131 EB |
777 | |
778 | /* Build '__builtin_setjmp_receiver (NEXT_LABEL)' and insert. */ | |
5039610b | 779 | arg = build_addr (next_label, current_function_decl); |
e79983f4 | 780 | t = builtin_decl_implicit (BUILT_IN_SETJMP_RECEIVER); |
726a989a | 781 | g = gimple_build_call (t, 1, arg); |
db3927fb | 782 | gimple_set_location (g, loc); |
cc2a64dd | 783 | gimple_set_block (g, gimple_block (stmt)); |
726a989a | 784 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
4f6c2131 EB |
785 | |
786 | /* Build 'DEST = 1' and insert. */ | |
787 | if (dest) | |
788 | { | |
db3927fb AH |
789 | g = gimple_build_assign (dest, fold_convert_loc (loc, TREE_TYPE (dest), |
790 | integer_one_node)); | |
791 | gimple_set_location (g, loc); | |
cc2a64dd | 792 | gimple_set_block (g, gimple_block (stmt)); |
726a989a | 793 | gsi_insert_before (gsi, g, GSI_SAME_STMT); |
4f6c2131 EB |
794 | } |
795 | ||
796 | /* Build 'CONT_LABEL:' and insert. */ | |
726a989a RB |
797 | g = gimple_build_label (cont_label); |
798 | gsi_insert_before (gsi, g, GSI_SAME_STMT); | |
4f6c2131 EB |
799 | |
800 | /* Remove the call to __builtin_setjmp. */ | |
726a989a | 801 | gsi_remove (gsi, false); |
f5a76aea | 802 | } |
831806cb RB |
803 | |
804 | /* Lower calls to posix_memalign to | |
c4c8514e RB |
805 | res = posix_memalign (ptr, align, size); |
806 | if (res == 0) | |
807 | *ptr = __builtin_assume_aligned (*ptr, align); | |
831806cb RB |
808 | or to |
809 | void *tem; | |
c4c8514e RB |
810 | res = posix_memalign (&tem, align, size); |
811 | if (res == 0) | |
812 | ptr = __builtin_assume_aligned (tem, align); | |
831806cb RB |
813 | in case the first argument was &ptr. That way we can get at the |
814 | alignment of the heap pointer in CCP. */ | |
815 | ||
816 | static void | |
817 | lower_builtin_posix_memalign (gimple_stmt_iterator *gsi) | |
818 | { | |
355fe088 | 819 | gimple *stmt, *call = gsi_stmt (*gsi); |
c4c8514e RB |
820 | tree pptr = gimple_call_arg (call, 0); |
821 | tree align = gimple_call_arg (call, 1); | |
822 | tree res = gimple_call_lhs (call); | |
b731b390 | 823 | tree ptr = create_tmp_reg (ptr_type_node); |
831806cb RB |
824 | if (TREE_CODE (pptr) == ADDR_EXPR) |
825 | { | |
b731b390 | 826 | tree tem = create_tmp_var (ptr_type_node); |
831806cb | 827 | TREE_ADDRESSABLE (tem) = 1; |
c4c8514e | 828 | gimple_call_set_arg (call, 0, build_fold_addr_expr (tem)); |
831806cb RB |
829 | stmt = gimple_build_assign (ptr, tem); |
830 | } | |
831 | else | |
832 | stmt = gimple_build_assign (ptr, | |
833 | fold_build2 (MEM_REF, ptr_type_node, pptr, | |
834 | build_int_cst (ptr_type_node, 0))); | |
c4c8514e RB |
835 | if (res == NULL_TREE) |
836 | { | |
b731b390 | 837 | res = create_tmp_reg (integer_type_node); |
c4c8514e RB |
838 | gimple_call_set_lhs (call, res); |
839 | } | |
840 | tree align_label = create_artificial_label (UNKNOWN_LOCATION); | |
841 | tree noalign_label = create_artificial_label (UNKNOWN_LOCATION); | |
355fe088 | 842 | gimple *cond = gimple_build_cond (EQ_EXPR, res, integer_zero_node, |
c4c8514e RB |
843 | align_label, noalign_label); |
844 | gsi_insert_after (gsi, cond, GSI_NEW_STMT); | |
845 | gsi_insert_after (gsi, gimple_build_label (align_label), GSI_NEW_STMT); | |
831806cb RB |
846 | gsi_insert_after (gsi, stmt, GSI_NEW_STMT); |
847 | stmt = gimple_build_call (builtin_decl_implicit (BUILT_IN_ASSUME_ALIGNED), | |
848 | 2, ptr, align); | |
849 | gimple_call_set_lhs (stmt, ptr); | |
850 | gsi_insert_after (gsi, stmt, GSI_NEW_STMT); | |
851 | stmt = gimple_build_assign (fold_build2 (MEM_REF, ptr_type_node, pptr, | |
852 | build_int_cst (ptr_type_node, 0)), | |
853 | ptr); | |
854 | gsi_insert_after (gsi, stmt, GSI_NEW_STMT); | |
c4c8514e | 855 | gsi_insert_after (gsi, gimple_build_label (noalign_label), GSI_NEW_STMT); |
831806cb | 856 | } |
6de9cd9a DN |
857 | \f |
858 | ||
50674e96 | 859 | /* Record the variables in VARS into function FN. */ |
6de9cd9a DN |
860 | |
861 | void | |
50674e96 | 862 | record_vars_into (tree vars, tree fn) |
6de9cd9a | 863 | { |
910ad8de | 864 | for (; vars; vars = DECL_CHAIN (vars)) |
6de9cd9a DN |
865 | { |
866 | tree var = vars; | |
867 | ||
acb8f212 JH |
868 | /* BIND_EXPRs contains also function/type/constant declarations |
869 | we don't need to care about. */ | |
870 | if (TREE_CODE (var) != VAR_DECL) | |
871 | continue; | |
50674e96 | 872 | |
6de9cd9a DN |
873 | /* Nothing to do in this case. */ |
874 | if (DECL_EXTERNAL (var)) | |
875 | continue; | |
6de9cd9a DN |
876 | |
877 | /* Record the variable. */ | |
45b62594 | 878 | add_local_decl (DECL_STRUCT_FUNCTION (fn), var); |
6de9cd9a | 879 | } |
50674e96 DN |
880 | } |
881 | ||
882 | ||
883 | /* Record the variables in VARS into current_function_decl. */ | |
884 | ||
885 | void | |
886 | record_vars (tree vars) | |
887 | { | |
888 | record_vars_into (vars, current_function_decl); | |
6de9cd9a | 889 | } |