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f7d118a9 | 1 | /* Callgraph based analysis of static variables. |
aad93da1 | 2 | Copyright (C) 2004-2017 Free Software Foundation, Inc. |
f7d118a9 | 3 | Contributed by Kenneth Zadeck <zadeck@naturalbridge.com> |
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 | |
8c4c00c1 | 9 | Software Foundation; either version 3, or (at your option) any later |
f7d118a9 | 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 | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
f7d118a9 | 20 | |
f0b5f617 | 21 | /* This file marks functions as being either const (TREE_READONLY) or |
22 | pure (DECL_PURE_P). It can also set a variant of these that | |
23 | are allowed to loop indefinitely (DECL_LOOPING_CONST_PURE_P). | |
f7d118a9 | 24 | |
25 | This must be run after inlining decisions have been made since | |
26 | otherwise, the local sets will not contain information that is | |
27 | consistent with post inlined state. The global sets are not prone | |
28 | to this problem since they are by definition transitive. */ | |
29 | ||
30 | /* The code in this module is called by the ipa pass manager. It | |
31 | should be one of the later passes since it's information is used by | |
32 | the rest of the compilation. */ | |
33 | ||
34 | #include "config.h" | |
35 | #include "system.h" | |
36 | #include "coretypes.h" | |
9ef16211 | 37 | #include "backend.h" |
7c29e30e | 38 | #include "target.h" |
f7d118a9 | 39 | #include "tree.h" |
9ef16211 | 40 | #include "gimple.h" |
7c29e30e | 41 | #include "tree-pass.h" |
42 | #include "tree-streamer.h" | |
43 | #include "cgraph.h" | |
44 | #include "diagnostic.h" | |
9ed99284 | 45 | #include "calls.h" |
94ea8568 | 46 | #include "cfganal.h" |
bc61cadb | 47 | #include "tree-eh.h" |
dcf1a1ec | 48 | #include "gimple-iterator.h" |
49 | #include "gimple-walk.h" | |
073c1fd5 | 50 | #include "tree-cfg.h" |
05d9c18a | 51 | #include "tree-ssa-loop-niter.h" |
f7d118a9 | 52 | #include "langhooks.h" |
f7d118a9 | 53 | #include "ipa-utils.h" |
ce084dfc | 54 | #include "gimple-pretty-print.h" |
c9263b6a | 55 | #include "cfgloop.h" |
56 | #include "tree-scalar-evolution.h" | |
2c06958d | 57 | #include "intl.h" |
58 | #include "opts.h" | |
f7d118a9 | 59 | |
60 | /* Lattice values for const and pure functions. Everything starts out | |
61 | being const, then may drop to pure and then neither depending on | |
62 | what is found. */ | |
63 | enum pure_const_state_e | |
64 | { | |
65 | IPA_CONST, | |
66 | IPA_PURE, | |
67 | IPA_NEITHER | |
68 | }; | |
69 | ||
fc94a528 | 70 | const char *pure_const_names[3] = {"const", "pure", "neither"}; |
71 | ||
cb886925 | 72 | /* Holder for the const_state. There is one of these per function |
73 | decl. */ | |
48e1416a | 74 | struct funct_state_d |
f7d118a9 | 75 | { |
cb886925 | 76 | /* See above. */ |
f7d118a9 | 77 | enum pure_const_state_e pure_const_state; |
b5cebd44 | 78 | /* What user set here; we can be always sure about this. */ |
48e1416a | 79 | enum pure_const_state_e state_previously_known; |
80 | bool looping_previously_known; | |
cb886925 | 81 | |
82 | /* True if the function could possibly infinite loop. There are a | |
83 | lot of ways that this could be determined. We are pretty | |
84 | conservative here. While it is possible to cse pure and const | |
85 | calls, it is not legal to have dce get rid of the call if there | |
86 | is a possibility that the call could infinite loop since this is | |
87 | a behavioral change. */ | |
9c2a0c05 | 88 | bool looping; |
cb886925 | 89 | |
b5cebd44 | 90 | bool can_throw; |
04c849b3 | 91 | |
92 | /* If function can call free, munmap or otherwise make previously | |
93 | non-trapping memory accesses trapping. */ | |
94 | bool can_free; | |
f7d118a9 | 95 | }; |
96 | ||
db86e424 | 97 | /* State used when we know nothing about function. */ |
98 | static struct funct_state_d varying_state | |
04c849b3 | 99 | = { IPA_NEITHER, IPA_NEITHER, true, true, true, true }; |
db86e424 | 100 | |
101 | ||
f7d118a9 | 102 | typedef struct funct_state_d * funct_state; |
103 | ||
cb886925 | 104 | /* The storage of the funct_state is abstracted because there is the |
105 | possibility that it may be desirable to move this to the cgraph | |
48e1416a | 106 | local info. */ |
cb886925 | 107 | |
108 | /* Array, indexed by cgraph node uid, of function states. */ | |
109 | ||
f1f41a6c | 110 | static vec<funct_state> funct_state_vec; |
cb886925 | 111 | |
415309e2 | 112 | static bool gate_pure_const (void); |
113 | ||
7620bc82 | 114 | namespace { |
115 | ||
116 | const pass_data pass_data_ipa_pure_const = | |
415309e2 | 117 | { |
118 | IPA_PASS, /* type */ | |
119 | "pure-const", /* name */ | |
120 | OPTGROUP_NONE, /* optinfo_flags */ | |
121 | TV_IPA_PURE_CONST, /* tv_id */ | |
122 | 0, /* properties_required */ | |
123 | 0, /* properties_provided */ | |
124 | 0, /* properties_destroyed */ | |
125 | 0, /* todo_flags_start */ | |
126 | 0, /* todo_flags_finish */ | |
127 | }; | |
128 | ||
7620bc82 | 129 | class pass_ipa_pure_const : public ipa_opt_pass_d |
415309e2 | 130 | { |
131 | public: | |
132 | pass_ipa_pure_const(gcc::context *ctxt); | |
133 | ||
134 | /* opt_pass methods: */ | |
135 | bool gate (function *) { return gate_pure_const (); } | |
136 | unsigned int execute (function *fun); | |
137 | ||
138 | void register_hooks (void); | |
139 | ||
140 | private: | |
141 | bool init_p; | |
142 | ||
143 | /* Holders of ipa cgraph hooks: */ | |
144 | struct cgraph_node_hook_list *function_insertion_hook_holder; | |
145 | struct cgraph_2node_hook_list *node_duplication_hook_holder; | |
146 | struct cgraph_node_hook_list *node_removal_hook_holder; | |
147 | ||
148 | }; // class pass_ipa_pure_const | |
149 | ||
7620bc82 | 150 | } // anon namespace |
151 | ||
2c06958d | 152 | /* Try to guess if function body will always be visible to compiler |
153 | when compiling the call and whether compiler will be able | |
154 | to propagate the information by itself. */ | |
155 | ||
156 | static bool | |
157 | function_always_visible_to_compiler_p (tree decl) | |
158 | { | |
60722a03 | 159 | return (!TREE_PUBLIC (decl) || DECL_DECLARED_INLINE_P (decl) |
160 | || DECL_COMDAT (decl)); | |
2c06958d | 161 | } |
162 | ||
163 | /* Emit suggestion about attribute ATTRIB_NAME for DECL. KNOWN_FINITE | |
164 | is true if the function is known to be finite. The diagnostic is | |
431205b7 | 165 | controlled by OPTION. WARNED_ABOUT is a hash_set<tree> unique for |
2c06958d | 166 | OPTION, this function may initialize it and it is always returned |
167 | by the function. */ | |
168 | ||
431205b7 | 169 | static hash_set<tree> * |
2c06958d | 170 | suggest_attribute (int option, tree decl, bool known_finite, |
431205b7 | 171 | hash_set<tree> *warned_about, |
2c06958d | 172 | const char * attrib_name) |
173 | { | |
2c5d2e39 | 174 | if (!option_enabled (option, &global_options)) |
2c06958d | 175 | return warned_about; |
176 | if (TREE_THIS_VOLATILE (decl) | |
177 | || (known_finite && function_always_visible_to_compiler_p (decl))) | |
178 | return warned_about; | |
179 | ||
180 | if (!warned_about) | |
431205b7 | 181 | warned_about = new hash_set<tree>; |
182 | if (warned_about->contains (decl)) | |
2c06958d | 183 | return warned_about; |
431205b7 | 184 | warned_about->add (decl); |
2c06958d | 185 | warning_at (DECL_SOURCE_LOCATION (decl), |
186 | option, | |
187 | known_finite | |
ca1f4c7a | 188 | ? G_("function might be candidate for attribute %qs") |
189 | : G_("function might be candidate for attribute %qs" | |
190 | " if it is known to return normally"), attrib_name); | |
2c06958d | 191 | return warned_about; |
192 | } | |
193 | ||
194 | /* Emit suggestion about __attribute_((pure)) for DECL. KNOWN_FINITE | |
195 | is true if the function is known to be finite. */ | |
196 | ||
197 | static void | |
198 | warn_function_pure (tree decl, bool known_finite) | |
199 | { | |
431205b7 | 200 | static hash_set<tree> *warned_about; |
2c06958d | 201 | |
202 | warned_about | |
203 | = suggest_attribute (OPT_Wsuggest_attribute_pure, decl, | |
204 | known_finite, warned_about, "pure"); | |
205 | } | |
206 | ||
207 | /* Emit suggestion about __attribute_((const)) for DECL. KNOWN_FINITE | |
208 | is true if the function is known to be finite. */ | |
209 | ||
210 | static void | |
211 | warn_function_const (tree decl, bool known_finite) | |
212 | { | |
431205b7 | 213 | static hash_set<tree> *warned_about; |
2c06958d | 214 | warned_about |
215 | = suggest_attribute (OPT_Wsuggest_attribute_const, decl, | |
216 | known_finite, warned_about, "const"); | |
217 | } | |
43d60d64 | 218 | |
64641360 | 219 | static void |
43d60d64 | 220 | warn_function_noreturn (tree decl) |
221 | { | |
313dfc4e | 222 | tree original_decl = decl; |
223 | ||
224 | cgraph_node *node = cgraph_node::get (decl); | |
225 | if (node->instrumentation_clone) | |
226 | decl = node->instrumented_version->decl; | |
227 | ||
431205b7 | 228 | static hash_set<tree> *warned_about; |
08c6cbd2 | 229 | if (!lang_hooks.missing_noreturn_ok_p (decl) |
230 | && targetm.warn_func_return (decl)) | |
43d60d64 | 231 | warned_about |
313dfc4e | 232 | = suggest_attribute (OPT_Wsuggest_attribute_noreturn, original_decl, |
43d60d64 | 233 | true, warned_about, "noreturn"); |
234 | } | |
9631926a | 235 | |
60722a03 | 236 | void |
237 | warn_function_cold (tree decl) | |
238 | { | |
239 | tree original_decl = decl; | |
240 | ||
241 | cgraph_node *node = cgraph_node::get (decl); | |
242 | if (node->instrumentation_clone) | |
243 | decl = node->instrumented_version->decl; | |
244 | ||
245 | static hash_set<tree> *warned_about; | |
246 | warned_about | |
247 | = suggest_attribute (OPT_Wsuggest_attribute_cold, original_decl, | |
248 | true, warned_about, "cold"); | |
249 | } | |
250 | ||
1ee39ad1 | 251 | /* Return true if we have a function state for NODE. */ |
252 | ||
253 | static inline bool | |
254 | has_function_state (struct cgraph_node *node) | |
255 | { | |
f1f41a6c | 256 | if (!funct_state_vec.exists () |
257 | || funct_state_vec.length () <= (unsigned int)node->uid) | |
1ee39ad1 | 258 | return false; |
f1f41a6c | 259 | return funct_state_vec[node->uid] != NULL; |
1ee39ad1 | 260 | } |
261 | ||
48e1416a | 262 | /* Return the function state from NODE. */ |
f7d118a9 | 263 | |
264 | static inline funct_state | |
265 | get_function_state (struct cgraph_node *node) | |
266 | { | |
f1f41a6c | 267 | if (!funct_state_vec.exists () |
268 | || funct_state_vec.length () <= (unsigned int)node->uid | |
269 | || !funct_state_vec[node->uid]) | |
1ee39ad1 | 270 | /* We might want to put correct previously_known state into varying. */ |
db86e424 | 271 | return &varying_state; |
f1f41a6c | 272 | return funct_state_vec[node->uid]; |
cb886925 | 273 | } |
274 | ||
275 | /* Set the function state S for NODE. */ | |
276 | ||
277 | static inline void | |
278 | set_function_state (struct cgraph_node *node, funct_state s) | |
279 | { | |
f1f41a6c | 280 | if (!funct_state_vec.exists () |
281 | || funct_state_vec.length () <= (unsigned int)node->uid) | |
282 | funct_state_vec.safe_grow_cleared (node->uid + 1); | |
af91a851 | 283 | |
284 | /* If funct_state_vec already contains a funct_state, we have to release | |
285 | it before it's going to be ovewritten. */ | |
286 | if (funct_state_vec[node->uid] != NULL | |
287 | && funct_state_vec[node->uid] != &varying_state) | |
288 | free (funct_state_vec[node->uid]); | |
289 | ||
f1f41a6c | 290 | funct_state_vec[node->uid] = s; |
f7d118a9 | 291 | } |
292 | ||
f0b5f617 | 293 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
f7d118a9 | 294 | variable T is legal in a function that is either pure or const. */ |
295 | ||
48e1416a | 296 | static inline void |
297 | check_decl (funct_state local, | |
023a28e1 | 298 | tree t, bool checking_write, bool ipa) |
f7d118a9 | 299 | { |
f7d118a9 | 300 | /* Do not want to do anything with volatile except mark any |
301 | function that uses one to be not const or pure. */ | |
48e1416a | 302 | if (TREE_THIS_VOLATILE (t)) |
303 | { | |
f7d118a9 | 304 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 305 | if (dump_file) |
306 | fprintf (dump_file, " Volatile operand is not const/pure"); | |
f7d118a9 | 307 | return; |
308 | } | |
309 | ||
310 | /* Do not care about a local automatic that is not static. */ | |
311 | if (!TREE_STATIC (t) && !DECL_EXTERNAL (t)) | |
312 | return; | |
313 | ||
b5cebd44 | 314 | /* If the variable has the "used" attribute, treat it as if it had a |
315 | been touched by the devil. */ | |
83a23b05 | 316 | if (DECL_PRESERVE_P (t)) |
b5cebd44 | 317 | { |
318 | local->pure_const_state = IPA_NEITHER; | |
319 | if (dump_file) | |
320 | fprintf (dump_file, " Used static/global variable is not const/pure\n"); | |
321 | return; | |
322 | } | |
323 | ||
023a28e1 | 324 | /* In IPA mode we are not interested in checking actual loads and stores; |
325 | they will be processed at propagation time using ipa_ref. */ | |
326 | if (ipa) | |
327 | return; | |
328 | ||
f7d118a9 | 329 | /* Since we have dealt with the locals and params cases above, if we |
330 | are CHECKING_WRITE, this cannot be a pure or constant | |
331 | function. */ | |
48e1416a | 332 | if (checking_write) |
bc17fd99 | 333 | { |
334 | local->pure_const_state = IPA_NEITHER; | |
b5cebd44 | 335 | if (dump_file) |
336 | fprintf (dump_file, " static/global memory write is not const/pure\n"); | |
bc17fd99 | 337 | return; |
338 | } | |
f7d118a9 | 339 | |
340 | if (DECL_EXTERNAL (t) || TREE_PUBLIC (t)) | |
341 | { | |
b5cebd44 | 342 | /* Readonly reads are safe. */ |
343 | if (TREE_READONLY (t) && !TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (t))) | |
344 | return; /* Read of a constant, do not change the function state. */ | |
48e1416a | 345 | else |
f7d118a9 | 346 | { |
b5cebd44 | 347 | if (dump_file) |
348 | fprintf (dump_file, " global memory read is not const\n"); | |
f7d118a9 | 349 | /* Just a regular read. */ |
350 | if (local->pure_const_state == IPA_CONST) | |
351 | local->pure_const_state = IPA_PURE; | |
352 | } | |
353 | } | |
b5cebd44 | 354 | else |
355 | { | |
356 | /* Compilation level statics can be read if they are readonly | |
357 | variables. */ | |
358 | if (TREE_READONLY (t)) | |
359 | return; | |
360 | ||
361 | if (dump_file) | |
362 | fprintf (dump_file, " static memory read is not const\n"); | |
363 | /* Just a regular read. */ | |
364 | if (local->pure_const_state == IPA_CONST) | |
365 | local->pure_const_state = IPA_PURE; | |
366 | } | |
f7d118a9 | 367 | } |
368 | ||
f7d118a9 | 369 | |
b5cebd44 | 370 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
371 | variable T is legal in a function that is either pure or const. */ | |
f7d118a9 | 372 | |
48e1416a | 373 | static inline void |
5ed0b345 | 374 | check_op (funct_state local, tree t, bool checking_write) |
f7d118a9 | 375 | { |
3ae61172 | 376 | t = get_base_address (t); |
377 | if (t && TREE_THIS_VOLATILE (t)) | |
f7d118a9 | 378 | { |
5ed0b345 | 379 | local->pure_const_state = IPA_NEITHER; |
380 | if (dump_file) | |
381 | fprintf (dump_file, " Volatile indirect ref is not const/pure\n"); | |
382 | return; | |
383 | } | |
3ae61172 | 384 | else if (t |
182cf5a9 | 385 | && (INDIRECT_REF_P (t) || TREE_CODE (t) == MEM_REF) |
3ae61172 | 386 | && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME |
387 | && !ptr_deref_may_alias_global_p (TREE_OPERAND (t, 0))) | |
388 | { | |
389 | if (dump_file) | |
390 | fprintf (dump_file, " Indirect ref to local memory is OK\n"); | |
391 | return; | |
392 | } | |
5ed0b345 | 393 | else if (checking_write) |
394 | { | |
395 | local->pure_const_state = IPA_NEITHER; | |
396 | if (dump_file) | |
397 | fprintf (dump_file, " Indirect ref write is not const/pure\n"); | |
398 | return; | |
399 | } | |
400 | else | |
401 | { | |
402 | if (dump_file) | |
403 | fprintf (dump_file, " Indirect ref read is not const\n"); | |
404 | if (local->pure_const_state == IPA_CONST) | |
405 | local->pure_const_state = IPA_PURE; | |
f7d118a9 | 406 | } |
407 | } | |
408 | ||
023a28e1 | 409 | /* compute state based on ECF FLAGS and store to STATE and LOOPING. */ |
410 | ||
411 | static void | |
412 | state_from_flags (enum pure_const_state_e *state, bool *looping, | |
413 | int flags, bool cannot_lead_to_return) | |
414 | { | |
415 | *looping = false; | |
416 | if (flags & ECF_LOOPING_CONST_OR_PURE) | |
417 | { | |
418 | *looping = true; | |
419 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
420 | fprintf (dump_file, " looping"); | |
421 | } | |
422 | if (flags & ECF_CONST) | |
423 | { | |
424 | *state = IPA_CONST; | |
425 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
426 | fprintf (dump_file, " const\n"); | |
427 | } | |
428 | else if (flags & ECF_PURE) | |
429 | { | |
430 | *state = IPA_PURE; | |
431 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
432 | fprintf (dump_file, " pure\n"); | |
433 | } | |
434 | else if (cannot_lead_to_return) | |
435 | { | |
436 | *state = IPA_PURE; | |
437 | *looping = true; | |
438 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
439 | fprintf (dump_file, " ignoring side effects->pure looping\n"); | |
440 | } | |
441 | else | |
442 | { | |
443 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
9631926a | 444 | fprintf (dump_file, " neither\n"); |
023a28e1 | 445 | *state = IPA_NEITHER; |
446 | *looping = true; | |
447 | } | |
448 | } | |
449 | ||
450 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
451 | into STATE and LOOPING better of the two variants. | |
452 | Be sure to merge looping correctly. IPA_NEITHER functions | |
453 | have looping 0 even if they don't have to return. */ | |
454 | ||
455 | static inline void | |
456 | better_state (enum pure_const_state_e *state, bool *looping, | |
457 | enum pure_const_state_e state2, bool looping2) | |
458 | { | |
459 | if (state2 < *state) | |
460 | { | |
461 | if (*state == IPA_NEITHER) | |
462 | *looping = looping2; | |
463 | else | |
464 | *looping = MIN (*looping, looping2); | |
26fc128e | 465 | *state = state2; |
023a28e1 | 466 | } |
467 | else if (state2 != IPA_NEITHER) | |
468 | *looping = MIN (*looping, looping2); | |
469 | } | |
470 | ||
471 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
8b4ee73c | 472 | into STATE and LOOPING worse of the two variants. |
473 | N is the actual node called. */ | |
023a28e1 | 474 | |
475 | static inline void | |
476 | worse_state (enum pure_const_state_e *state, bool *looping, | |
8b4ee73c | 477 | enum pure_const_state_e state2, bool looping2, |
478 | struct symtab_node *from, | |
479 | struct symtab_node *to) | |
023a28e1 | 480 | { |
8b4ee73c | 481 | /* Consider function: |
482 | ||
483 | bool a(int *p) | |
484 | { | |
485 | return *p==*p; | |
486 | } | |
487 | ||
488 | During early optimization we will turn this into: | |
489 | ||
490 | bool a(int *p) | |
491 | { | |
492 | return true; | |
493 | } | |
494 | ||
495 | Now if this function will be detected as CONST however when interposed it | |
496 | may end up being just pure. We always must assume the worst scenario here. | |
497 | */ | |
498 | if (*state == IPA_CONST && state2 == IPA_CONST | |
499 | && to && !TREE_READONLY (to->decl) && !to->binds_to_current_def_p (from)) | |
500 | { | |
501 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
502 | fprintf (dump_file, "Dropping state to PURE because call to %s may not " | |
503 | "bind to current def.\n", to->name ()); | |
504 | state2 = IPA_PURE; | |
505 | } | |
023a28e1 | 506 | *state = MAX (*state, state2); |
507 | *looping = MAX (*looping, looping2); | |
508 | } | |
509 | ||
0a10fd82 | 510 | /* Recognize special cases of builtins that are by themselves not pure or const |
7dd42908 | 511 | but function using them is. */ |
512 | static bool | |
a53e7471 | 513 | special_builtin_state (enum pure_const_state_e *state, bool *looping, |
7dd42908 | 514 | tree callee) |
515 | { | |
516 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
517 | switch (DECL_FUNCTION_CODE (callee)) | |
518 | { | |
519 | case BUILT_IN_RETURN: | |
520 | case BUILT_IN_UNREACHABLE: | |
2b34677f | 521 | CASE_BUILT_IN_ALLOCA: |
7dd42908 | 522 | case BUILT_IN_STACK_SAVE: |
523 | case BUILT_IN_STACK_RESTORE: | |
524 | case BUILT_IN_EH_POINTER: | |
525 | case BUILT_IN_EH_FILTER: | |
526 | case BUILT_IN_UNWIND_RESUME: | |
527 | case BUILT_IN_CXA_END_CLEANUP: | |
528 | case BUILT_IN_EH_COPY_VALUES: | |
529 | case BUILT_IN_FRAME_ADDRESS: | |
530 | case BUILT_IN_APPLY: | |
531 | case BUILT_IN_APPLY_ARGS: | |
a940fdc7 | 532 | case BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT: |
533 | case BUILT_IN_ASAN_AFTER_DYNAMIC_INIT: | |
7dd42908 | 534 | *looping = false; |
535 | *state = IPA_CONST; | |
536 | return true; | |
537 | case BUILT_IN_PREFETCH: | |
538 | *looping = true; | |
539 | *state = IPA_CONST; | |
540 | return true; | |
5213d6c9 | 541 | default: |
542 | break; | |
7dd42908 | 543 | } |
544 | return false; | |
545 | } | |
546 | ||
f7d118a9 | 547 | /* Check the parameters of a function call to CALL_EXPR to see if |
548 | there are any references in the parameters that are not allowed for | |
549 | pure or const functions. Also check to see if this is either an | |
550 | indirect call, a call outside the compilation unit, or has special | |
551 | attributes that may also effect the purity. The CALL_EXPR node for | |
552 | the entire call expression. */ | |
553 | ||
554 | static void | |
1a91d914 | 555 | check_call (funct_state local, gcall *call, bool ipa) |
f7d118a9 | 556 | { |
75a70cf9 | 557 | int flags = gimple_call_flags (call); |
b5cebd44 | 558 | tree callee_t = gimple_call_fndecl (call); |
b5cebd44 | 559 | bool possibly_throws = stmt_could_throw_p (call); |
560 | bool possibly_throws_externally = (possibly_throws | |
561 | && stmt_can_throw_external (call)); | |
f7d118a9 | 562 | |
b5cebd44 | 563 | if (possibly_throws) |
564 | { | |
565 | unsigned int i; | |
566 | for (i = 0; i < gimple_num_ops (call); i++) | |
567 | if (gimple_op (call, i) | |
568 | && tree_could_throw_p (gimple_op (call, i))) | |
569 | { | |
cbeb677e | 570 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 571 | { |
572 | if (dump_file) | |
573 | fprintf (dump_file, " operand can throw; looping\n"); | |
574 | local->looping = true; | |
575 | } | |
576 | if (possibly_throws_externally) | |
577 | { | |
578 | if (dump_file) | |
579 | fprintf (dump_file, " operand can throw externally\n"); | |
580 | local->can_throw = true; | |
581 | } | |
582 | } | |
583 | } | |
48e1416a | 584 | |
f7d118a9 | 585 | /* The const and pure flags are set by a variety of places in the |
586 | compiler (including here). If someone has already set the flags | |
587 | for the callee, (such as for some of the builtins) we will use | |
48e1416a | 588 | them, otherwise we will compute our own information. |
589 | ||
f7d118a9 | 590 | Const and pure functions have less clobber effects than other |
591 | functions so we process these first. Otherwise if it is a call | |
592 | outside the compilation unit or an indirect call we punt. This | |
593 | leaves local calls which will be processed by following the call | |
48e1416a | 594 | graph. */ |
f7d118a9 | 595 | if (callee_t) |
596 | { | |
7dd42908 | 597 | enum pure_const_state_e call_state; |
598 | bool call_looping; | |
599 | ||
04c849b3 | 600 | if (gimple_call_builtin_p (call, BUILT_IN_NORMAL) |
601 | && !nonfreeing_call_p (call)) | |
602 | local->can_free = true; | |
603 | ||
a53e7471 | 604 | if (special_builtin_state (&call_state, &call_looping, callee_t)) |
7dd42908 | 605 | { |
606 | worse_state (&local->pure_const_state, &local->looping, | |
8b4ee73c | 607 | call_state, call_looping, |
608 | NULL, NULL); | |
7dd42908 | 609 | return; |
610 | } | |
f7d118a9 | 611 | /* When bad things happen to bad functions, they cannot be const |
612 | or pure. */ | |
613 | if (setjmp_call_p (callee_t)) | |
9c2a0c05 | 614 | { |
b5cebd44 | 615 | if (dump_file) |
616 | fprintf (dump_file, " setjmp is not const/pure\n"); | |
617 | local->looping = true; | |
9c2a0c05 | 618 | local->pure_const_state = IPA_NEITHER; |
9c2a0c05 | 619 | } |
f7d118a9 | 620 | |
621 | if (DECL_BUILT_IN_CLASS (callee_t) == BUILT_IN_NORMAL) | |
622 | switch (DECL_FUNCTION_CODE (callee_t)) | |
623 | { | |
624 | case BUILT_IN_LONGJMP: | |
625 | case BUILT_IN_NONLOCAL_GOTO: | |
b5cebd44 | 626 | if (dump_file) |
627 | fprintf (dump_file, " longjmp and nonlocal goto is not const/pure\n"); | |
f7d118a9 | 628 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 629 | local->looping = true; |
f7d118a9 | 630 | break; |
631 | default: | |
632 | break; | |
633 | } | |
634 | } | |
04c849b3 | 635 | else if (gimple_call_internal_p (call) && !nonfreeing_call_p (call)) |
636 | local->can_free = true; | |
f7d118a9 | 637 | |
b5cebd44 | 638 | /* When not in IPA mode, we can still handle self recursion. */ |
e9de52cc | 639 | if (!ipa && callee_t |
640 | && recursive_call_p (current_function_decl, callee_t)) | |
2c06958d | 641 | { |
642 | if (dump_file) | |
643 | fprintf (dump_file, " Recursive call can loop.\n"); | |
644 | local->looping = true; | |
645 | } | |
0a10fd82 | 646 | /* Either callee is unknown or we are doing local analysis. |
ef378c27 | 647 | Look to see if there are any bits available for the callee (such as by |
648 | declaration or because it is builtin) and process solely on the basis of | |
621733d8 | 649 | those bits. Handle internal calls always, those calls don't have |
650 | corresponding cgraph edges and thus aren't processed during | |
651 | the propagation. */ | |
652 | else if (!ipa || gimple_call_internal_p (call)) | |
f7d118a9 | 653 | { |
023a28e1 | 654 | enum pure_const_state_e call_state; |
655 | bool call_looping; | |
cbeb677e | 656 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 657 | { |
658 | if (dump_file) | |
659 | fprintf (dump_file, " can throw; looping\n"); | |
660 | local->looping = true; | |
661 | } | |
662 | if (possibly_throws_externally) | |
663 | { | |
664 | if (dump_file) | |
665 | { | |
e38def9c | 666 | fprintf (dump_file, " can throw externally to lp %i\n", |
667 | lookup_stmt_eh_lp (call)); | |
b5cebd44 | 668 | if (callee_t) |
669 | fprintf (dump_file, " callee:%s\n", | |
670 | IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (callee_t))); | |
671 | } | |
672 | local->can_throw = true; | |
673 | } | |
023a28e1 | 674 | if (dump_file && (dump_flags & TDF_DETAILS)) |
675 | fprintf (dump_file, " checking flags for call:"); | |
676 | state_from_flags (&call_state, &call_looping, flags, | |
677 | ((flags & (ECF_NORETURN | ECF_NOTHROW)) | |
678 | == (ECF_NORETURN | ECF_NOTHROW)) | |
679 | || (!flag_exceptions && (flags & ECF_NORETURN))); | |
680 | worse_state (&local->pure_const_state, &local->looping, | |
8b4ee73c | 681 | call_state, call_looping, NULL, NULL); |
f7d118a9 | 682 | } |
b5cebd44 | 683 | /* Direct functions calls are handled by IPA propagation. */ |
f7d118a9 | 684 | } |
685 | ||
023a28e1 | 686 | /* Wrapper around check_decl for loads in local more. */ |
5ed0b345 | 687 | |
688 | static bool | |
42acab1c | 689 | check_load (gimple *, tree op, tree, void *data) |
5ed0b345 | 690 | { |
691 | if (DECL_P (op)) | |
023a28e1 | 692 | check_decl ((funct_state)data, op, false, false); |
5ed0b345 | 693 | else |
694 | check_op ((funct_state)data, op, false); | |
695 | return false; | |
696 | } | |
697 | ||
023a28e1 | 698 | /* Wrapper around check_decl for stores in local more. */ |
5ed0b345 | 699 | |
700 | static bool | |
42acab1c | 701 | check_store (gimple *, tree op, tree, void *data) |
5ed0b345 | 702 | { |
703 | if (DECL_P (op)) | |
023a28e1 | 704 | check_decl ((funct_state)data, op, true, false); |
705 | else | |
706 | check_op ((funct_state)data, op, true); | |
707 | return false; | |
708 | } | |
709 | ||
710 | /* Wrapper around check_decl for loads in ipa mode. */ | |
711 | ||
712 | static bool | |
42acab1c | 713 | check_ipa_load (gimple *, tree op, tree, void *data) |
023a28e1 | 714 | { |
715 | if (DECL_P (op)) | |
716 | check_decl ((funct_state)data, op, false, true); | |
717 | else | |
718 | check_op ((funct_state)data, op, false); | |
719 | return false; | |
720 | } | |
721 | ||
722 | /* Wrapper around check_decl for stores in ipa mode. */ | |
723 | ||
724 | static bool | |
42acab1c | 725 | check_ipa_store (gimple *, tree op, tree, void *data) |
023a28e1 | 726 | { |
727 | if (DECL_P (op)) | |
728 | check_decl ((funct_state)data, op, true, true); | |
5ed0b345 | 729 | else |
730 | check_op ((funct_state)data, op, true); | |
731 | return false; | |
732 | } | |
733 | ||
dd277d48 | 734 | /* Look into pointer pointed to by GSIP and figure out what interesting side |
735 | effects it has. */ | |
b5cebd44 | 736 | static void |
737 | check_stmt (gimple_stmt_iterator *gsip, funct_state local, bool ipa) | |
f7d118a9 | 738 | { |
42acab1c | 739 | gimple *stmt = gsi_stmt (*gsip); |
f7d118a9 | 740 | |
9845d120 | 741 | if (is_gimple_debug (stmt)) |
742 | return; | |
743 | ||
73594827 | 744 | /* Do consider clobber as side effects before IPA, so we rather inline |
745 | C++ destructors and keep clobber semantics than eliminate them. | |
746 | ||
747 | TODO: We may get smarter during early optimizations on these and let | |
748 | functions containing only clobbers to be optimized more. This is a common | |
749 | case of C++ destructors. */ | |
750 | ||
751 | if ((ipa || cfun->after_inlining) && gimple_clobber_p (stmt)) | |
752 | return; | |
753 | ||
b5cebd44 | 754 | if (dump_file) |
f7d118a9 | 755 | { |
b5cebd44 | 756 | fprintf (dump_file, " scanning: "); |
1ffa4346 | 757 | print_gimple_stmt (dump_file, stmt, 0); |
b5cebd44 | 758 | } |
dd277d48 | 759 | |
541c6dbb | 760 | if (gimple_has_volatile_ops (stmt) |
761 | && !gimple_clobber_p (stmt)) | |
4b68df2e | 762 | { |
763 | local->pure_const_state = IPA_NEITHER; | |
764 | if (dump_file) | |
765 | fprintf (dump_file, " Volatile stmt is not const/pure\n"); | |
766 | } | |
767 | ||
5ed0b345 | 768 | /* Look for loads and stores. */ |
023a28e1 | 769 | walk_stmt_load_store_ops (stmt, local, |
770 | ipa ? check_ipa_load : check_load, | |
771 | ipa ? check_ipa_store : check_store); | |
b5cebd44 | 772 | |
773 | if (gimple_code (stmt) != GIMPLE_CALL | |
774 | && stmt_could_throw_p (stmt)) | |
775 | { | |
cbeb677e | 776 | if (cfun->can_throw_non_call_exceptions) |
b5cebd44 | 777 | { |
778 | if (dump_file) | |
10f4615f | 779 | fprintf (dump_file, " can throw; looping\n"); |
b5cebd44 | 780 | local->looping = true; |
781 | } | |
782 | if (stmt_can_throw_external (stmt)) | |
783 | { | |
784 | if (dump_file) | |
10f4615f | 785 | fprintf (dump_file, " can throw externally\n"); |
b5cebd44 | 786 | local->can_throw = true; |
787 | } | |
10f4615f | 788 | else |
789 | if (dump_file) | |
790 | fprintf (dump_file, " can throw\n"); | |
75a70cf9 | 791 | } |
75a70cf9 | 792 | switch (gimple_code (stmt)) |
793 | { | |
b5cebd44 | 794 | case GIMPLE_CALL: |
1a91d914 | 795 | check_call (local, as_a <gcall *> (stmt), ipa); |
f7d118a9 | 796 | break; |
75a70cf9 | 797 | case GIMPLE_LABEL: |
1a91d914 | 798 | if (DECL_NONLOCAL (gimple_label_label (as_a <glabel *> (stmt)))) |
f7d118a9 | 799 | /* Target of long jump. */ |
9c2a0c05 | 800 | { |
b5cebd44 | 801 | if (dump_file) |
10f4615f | 802 | fprintf (dump_file, " nonlocal label is not const/pure\n"); |
9c2a0c05 | 803 | local->pure_const_state = IPA_NEITHER; |
9c2a0c05 | 804 | } |
f7d118a9 | 805 | break; |
75a70cf9 | 806 | case GIMPLE_ASM: |
1a91d914 | 807 | if (gimple_asm_clobbers_memory_p (as_a <gasm *> (stmt))) |
b5cebd44 | 808 | { |
97cf41ec | 809 | if (dump_file) |
10f4615f | 810 | fprintf (dump_file, " memory asm clobber is not const/pure\n"); |
97cf41ec | 811 | /* Abandon all hope, ye who enter here. */ |
812 | local->pure_const_state = IPA_NEITHER; | |
04c849b3 | 813 | local->can_free = true; |
b5cebd44 | 814 | } |
1a91d914 | 815 | if (gimple_asm_volatile_p (as_a <gasm *> (stmt))) |
b5cebd44 | 816 | { |
817 | if (dump_file) | |
10f4615f | 818 | fprintf (dump_file, " volatile is not const/pure\n"); |
b5cebd44 | 819 | /* Abandon all hope, ye who enter here. */ |
820 | local->pure_const_state = IPA_NEITHER; | |
04c849b3 | 821 | local->looping = true; |
822 | local->can_free = true; | |
b5cebd44 | 823 | } |
824 | return; | |
f7d118a9 | 825 | default: |
826 | break; | |
827 | } | |
f7d118a9 | 828 | } |
829 | ||
cb886925 | 830 | |
f7d118a9 | 831 | /* This is the main routine for finding the reference patterns for |
832 | global variables within a function FN. */ | |
833 | ||
b5cebd44 | 834 | static funct_state |
835 | analyze_function (struct cgraph_node *fn, bool ipa) | |
f7d118a9 | 836 | { |
02774f2d | 837 | tree decl = fn->decl; |
b5cebd44 | 838 | funct_state l; |
839 | basic_block this_block; | |
f7d118a9 | 840 | |
b5cebd44 | 841 | l = XCNEW (struct funct_state_d); |
842 | l->pure_const_state = IPA_CONST; | |
df9b545b | 843 | l->state_previously_known = IPA_NEITHER; |
844 | l->looping_previously_known = true; | |
b5cebd44 | 845 | l->looping = false; |
846 | l->can_throw = false; | |
04c849b3 | 847 | l->can_free = false; |
91bf9d9a | 848 | state_from_flags (&l->state_previously_known, &l->looping_previously_known, |
02774f2d | 849 | flags_from_decl_or_type (fn->decl), |
415d1b9a | 850 | fn->cannot_return_p ()); |
91bf9d9a | 851 | |
02774f2d | 852 | if (fn->thunk.thunk_p || fn->alias) |
91bf9d9a | 853 | { |
854 | /* Thunk gets propagated through, so nothing interesting happens. */ | |
855 | gcc_assert (ipa); | |
cfd85d03 | 856 | if (fn->thunk.thunk_p && fn->thunk.virtual_offset_p) |
857 | l->pure_const_state = IPA_NEITHER; | |
91bf9d9a | 858 | return l; |
859 | } | |
f7d118a9 | 860 | |
861 | if (dump_file) | |
862 | { | |
48e1416a | 863 | fprintf (dump_file, "\n\n local analysis of %s\n ", |
f1c8b4d7 | 864 | fn->name ()); |
f7d118a9 | 865 | } |
48e1416a | 866 | |
b5cebd44 | 867 | push_cfun (DECL_STRUCT_FUNCTION (decl)); |
48e1416a | 868 | |
fc00614f | 869 | FOR_EACH_BB_FN (this_block, cfun) |
f7d118a9 | 870 | { |
b5cebd44 | 871 | gimple_stmt_iterator gsi; |
872 | struct walk_stmt_info wi; | |
f7d118a9 | 873 | |
9af5ce0c | 874 | memset (&wi, 0, sizeof (wi)); |
b5cebd44 | 875 | for (gsi = gsi_start_bb (this_block); |
876 | !gsi_end_p (gsi); | |
877 | gsi_next (&gsi)) | |
f7d118a9 | 878 | { |
b5cebd44 | 879 | check_stmt (&gsi, l, ipa); |
04c849b3 | 880 | if (l->pure_const_state == IPA_NEITHER |
881 | && l->looping | |
882 | && l->can_throw | |
883 | && l->can_free) | |
b5cebd44 | 884 | goto end; |
f7d118a9 | 885 | } |
886 | } | |
dcccac3e | 887 | |
888 | end: | |
b5cebd44 | 889 | if (l->pure_const_state != IPA_NEITHER) |
890 | { | |
891 | /* Const functions cannot have back edges (an | |
892 | indication of possible infinite loop side | |
893 | effect. */ | |
894 | if (mark_dfs_back_edges ()) | |
c9263b6a | 895 | { |
b1887855 | 896 | /* Preheaders are needed for SCEV to work. |
0a10fd82 | 897 | Simple latches and recorded exits improve chances that loop will |
8ff30f9a | 898 | proved to be finite in testcases such as in loop-15.c |
899 | and loop-24.c */ | |
900 | loop_optimizer_init (LOOPS_HAVE_PREHEADERS | |
901 | | LOOPS_HAVE_SIMPLE_LATCHES | |
b1887855 | 902 | | LOOPS_HAVE_RECORDED_EXITS); |
c9263b6a | 903 | if (dump_file && (dump_flags & TDF_DETAILS)) |
904 | flow_loops_dump (dump_file, NULL, 0); | |
905 | if (mark_irreducible_loops ()) | |
906 | { | |
907 | if (dump_file) | |
908 | fprintf (dump_file, " has irreducible loops\n"); | |
909 | l->looping = true; | |
910 | } | |
48e1416a | 911 | else |
c9263b6a | 912 | { |
c9263b6a | 913 | struct loop *loop; |
914 | scev_initialize (); | |
f21d4d00 | 915 | FOR_EACH_LOOP (loop, 0) |
c9263b6a | 916 | if (!finite_loop_p (loop)) |
917 | { | |
918 | if (dump_file) | |
8ff30f9a | 919 | fprintf (dump_file, " can not prove finiteness of " |
920 | "loop %i\n", loop->num); | |
c9263b6a | 921 | l->looping =true; |
f21d4d00 | 922 | break; |
c9263b6a | 923 | } |
924 | scev_finalize (); | |
925 | } | |
926 | loop_optimizer_finalize (); | |
927 | } | |
b5cebd44 | 928 | } |
929 | ||
023a28e1 | 930 | if (dump_file && (dump_flags & TDF_DETAILS)) |
931 | fprintf (dump_file, " checking previously known:"); | |
023a28e1 | 932 | |
933 | better_state (&l->pure_const_state, &l->looping, | |
934 | l->state_previously_known, | |
935 | l->looping_previously_known); | |
b5cebd44 | 936 | if (TREE_NOTHROW (decl)) |
937 | l->can_throw = false; | |
938 | ||
939 | pop_cfun (); | |
dcccac3e | 940 | if (dump_file) |
941 | { | |
b5cebd44 | 942 | if (l->looping) |
943 | fprintf (dump_file, "Function is locally looping.\n"); | |
944 | if (l->can_throw) | |
945 | fprintf (dump_file, "Function is locally throwing.\n"); | |
946 | if (l->pure_const_state == IPA_CONST) | |
947 | fprintf (dump_file, "Function is locally const.\n"); | |
948 | if (l->pure_const_state == IPA_PURE) | |
949 | fprintf (dump_file, "Function is locally pure.\n"); | |
04c849b3 | 950 | if (l->can_free) |
951 | fprintf (dump_file, "Function can locally free.\n"); | |
dcccac3e | 952 | } |
b5cebd44 | 953 | return l; |
f7d118a9 | 954 | } |
955 | ||
50828ed8 | 956 | /* Called when new function is inserted to callgraph late. */ |
957 | static void | |
958 | add_new_function (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED) | |
959 | { | |
50828ed8 | 960 | /* There are some shared nodes, in particular the initializers on |
961 | static declarations. We do not need to scan them more than once | |
962 | since all we would be interested in are the addressof | |
963 | operations. */ | |
8b4ee73c | 964 | if (opt_for_fn (node->decl, flag_ipa_pure_const)) |
2c06958d | 965 | set_function_state (node, analyze_function (node, true)); |
50828ed8 | 966 | } |
967 | ||
86844d6c | 968 | /* Called when new clone is inserted to callgraph late. */ |
969 | ||
970 | static void | |
971 | duplicate_node_data (struct cgraph_node *src, struct cgraph_node *dst, | |
972 | void *data ATTRIBUTE_UNUSED) | |
973 | { | |
1ee39ad1 | 974 | if (has_function_state (src)) |
86844d6c | 975 | { |
976 | funct_state l = XNEW (struct funct_state_d); | |
1ee39ad1 | 977 | gcc_assert (!has_function_state (dst)); |
86844d6c | 978 | memcpy (l, get_function_state (src), sizeof (*l)); |
979 | set_function_state (dst, l); | |
980 | } | |
981 | } | |
982 | ||
983 | /* Called when new clone is inserted to callgraph late. */ | |
984 | ||
985 | static void | |
986 | remove_node_data (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED) | |
987 | { | |
1ee39ad1 | 988 | if (has_function_state (node)) |
af91a851 | 989 | set_function_state (node, NULL); |
86844d6c | 990 | } |
991 | ||
f7d118a9 | 992 | \f |
415309e2 | 993 | void |
994 | pass_ipa_pure_const:: | |
7bfefa9d | 995 | register_hooks (void) |
f7d118a9 | 996 | { |
7bfefa9d | 997 | if (init_p) |
998 | return; | |
999 | ||
1000 | init_p = true; | |
f7d118a9 | 1001 | |
86844d6c | 1002 | node_removal_hook_holder = |
35ee1c66 | 1003 | symtab->add_cgraph_removal_hook (&remove_node_data, NULL); |
86844d6c | 1004 | node_duplication_hook_holder = |
35ee1c66 | 1005 | symtab->add_cgraph_duplication_hook (&duplicate_node_data, NULL); |
50828ed8 | 1006 | function_insertion_hook_holder = |
35ee1c66 | 1007 | symtab->add_cgraph_insertion_hook (&add_new_function, NULL); |
7bfefa9d | 1008 | } |
1009 | ||
1010 | ||
1011 | /* Analyze each function in the cgraph to see if it is locally PURE or | |
1012 | CONST. */ | |
1013 | ||
48e1416a | 1014 | static void |
80880eb6 | 1015 | pure_const_generate_summary (void) |
7bfefa9d | 1016 | { |
1017 | struct cgraph_node *node; | |
1018 | ||
415309e2 | 1019 | pass_ipa_pure_const *pass = static_cast <pass_ipa_pure_const *> (current_pass); |
1020 | pass->register_hooks (); | |
7bfefa9d | 1021 | |
48e1416a | 1022 | /* Process all of the functions. |
f7d118a9 | 1023 | |
415d1b9a | 1024 | We process AVAIL_INTERPOSABLE functions. We can not use the results |
ef378c27 | 1025 | by default, but the info can be used at LTO with -fwhole-program or |
0a10fd82 | 1026 | when function got cloned and the clone is AVAILABLE. */ |
ef378c27 | 1027 | |
7c455d87 | 1028 | FOR_EACH_DEFINED_FUNCTION (node) |
8b4ee73c | 1029 | if (opt_for_fn (node->decl, flag_ipa_pure_const)) |
b5cebd44 | 1030 | set_function_state (node, analyze_function (node, true)); |
cb886925 | 1031 | } |
1032 | ||
7bfefa9d | 1033 | |
1034 | /* Serialize the ipa info for lto. */ | |
1035 | ||
1036 | static void | |
eab36a5a | 1037 | pure_const_write_summary (void) |
7bfefa9d | 1038 | { |
1039 | struct cgraph_node *node; | |
1040 | struct lto_simple_output_block *ob | |
1041 | = lto_create_simple_output_block (LTO_section_ipa_pure_const); | |
1042 | unsigned int count = 0; | |
eab36a5a | 1043 | lto_symtab_encoder_iterator lsei; |
1044 | lto_symtab_encoder_t encoder; | |
7bfefa9d | 1045 | |
eab36a5a | 1046 | encoder = lto_get_out_decl_state ()->symtab_node_encoder; |
1047 | ||
1048 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); | |
1049 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 1050 | { |
eab36a5a | 1051 | node = lsei_cgraph_node (lsei); |
02774f2d | 1052 | if (node->definition && has_function_state (node)) |
7bfefa9d | 1053 | count++; |
1054 | } | |
48e1416a | 1055 | |
7f385784 | 1056 | streamer_write_uhwi_stream (ob->main_stream, count); |
48e1416a | 1057 | |
7bfefa9d | 1058 | /* Process all of the functions. */ |
eab36a5a | 1059 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); |
1060 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 1061 | { |
eab36a5a | 1062 | node = lsei_cgraph_node (lsei); |
02774f2d | 1063 | if (node->definition && has_function_state (node)) |
7bfefa9d | 1064 | { |
30baba90 | 1065 | struct bitpack_d bp; |
7bfefa9d | 1066 | funct_state fs; |
1067 | int node_ref; | |
70225339 | 1068 | lto_symtab_encoder_t encoder; |
48e1416a | 1069 | |
7bfefa9d | 1070 | fs = get_function_state (node); |
1071 | ||
70225339 | 1072 | encoder = ob->decl_state->symtab_node_encoder; |
02774f2d | 1073 | node_ref = lto_symtab_encoder_encode (encoder, node); |
7f385784 | 1074 | streamer_write_uhwi_stream (ob->main_stream, node_ref); |
48e1416a | 1075 | |
7bfefa9d | 1076 | /* Note that flags will need to be read in the opposite |
1077 | order as we are pushing the bitflags into FLAGS. */ | |
30baba90 | 1078 | bp = bitpack_create (ob->main_stream); |
1079 | bp_pack_value (&bp, fs->pure_const_state, 2); | |
1080 | bp_pack_value (&bp, fs->state_previously_known, 2); | |
1081 | bp_pack_value (&bp, fs->looping_previously_known, 1); | |
1082 | bp_pack_value (&bp, fs->looping, 1); | |
1083 | bp_pack_value (&bp, fs->can_throw, 1); | |
04c849b3 | 1084 | bp_pack_value (&bp, fs->can_free, 1); |
7f385784 | 1085 | streamer_write_bitpack (&bp); |
7bfefa9d | 1086 | } |
1087 | } | |
1088 | ||
1089 | lto_destroy_simple_output_block (ob); | |
1090 | } | |
1091 | ||
1092 | ||
1093 | /* Deserialize the ipa info for lto. */ | |
1094 | ||
48e1416a | 1095 | static void |
7bfefa9d | 1096 | pure_const_read_summary (void) |
1097 | { | |
1098 | struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); | |
1099 | struct lto_file_decl_data *file_data; | |
1100 | unsigned int j = 0; | |
1101 | ||
415309e2 | 1102 | pass_ipa_pure_const *pass = static_cast <pass_ipa_pure_const *> (current_pass); |
1103 | pass->register_hooks (); | |
1104 | ||
7bfefa9d | 1105 | while ((file_data = file_data_vec[j++])) |
1106 | { | |
1107 | const char *data; | |
1108 | size_t len; | |
1109 | struct lto_input_block *ib | |
48e1416a | 1110 | = lto_create_simple_input_block (file_data, |
1111 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1112 | &data, &len); |
1113 | if (ib) | |
1114 | { | |
1115 | unsigned int i; | |
7f385784 | 1116 | unsigned int count = streamer_read_uhwi (ib); |
7bfefa9d | 1117 | |
1118 | for (i = 0; i < count; i++) | |
1119 | { | |
1120 | unsigned int index; | |
1121 | struct cgraph_node *node; | |
30baba90 | 1122 | struct bitpack_d bp; |
7bfefa9d | 1123 | funct_state fs; |
70225339 | 1124 | lto_symtab_encoder_t encoder; |
7bfefa9d | 1125 | |
1126 | fs = XCNEW (struct funct_state_d); | |
7f385784 | 1127 | index = streamer_read_uhwi (ib); |
70225339 | 1128 | encoder = file_data->symtab_node_encoder; |
415d1b9a | 1129 | node = dyn_cast<cgraph_node *> (lto_symtab_encoder_deref (encoder, |
1130 | index)); | |
7bfefa9d | 1131 | set_function_state (node, fs); |
1132 | ||
1133 | /* Note that the flags must be read in the opposite | |
1134 | order in which they were written (the bitflags were | |
1135 | pushed into FLAGS). */ | |
7f385784 | 1136 | bp = streamer_read_bitpack (ib); |
7bfefa9d | 1137 | fs->pure_const_state |
30baba90 | 1138 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
7bfefa9d | 1139 | fs->state_previously_known |
30baba90 | 1140 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
1141 | fs->looping_previously_known = bp_unpack_value (&bp, 1); | |
1142 | fs->looping = bp_unpack_value (&bp, 1); | |
1143 | fs->can_throw = bp_unpack_value (&bp, 1); | |
04c849b3 | 1144 | fs->can_free = bp_unpack_value (&bp, 1); |
fc94a528 | 1145 | if (dump_file) |
1146 | { | |
02774f2d | 1147 | int flags = flags_from_decl_or_type (node->decl); |
0e388735 | 1148 | fprintf (dump_file, "Read info for %s ", node->dump_name ()); |
fc94a528 | 1149 | if (flags & ECF_CONST) |
1150 | fprintf (dump_file, " const"); | |
1151 | if (flags & ECF_PURE) | |
1152 | fprintf (dump_file, " pure"); | |
1153 | if (flags & ECF_NOTHROW) | |
1154 | fprintf (dump_file, " nothrow"); | |
1155 | fprintf (dump_file, "\n pure const state: %s\n", | |
1156 | pure_const_names[fs->pure_const_state]); | |
1157 | fprintf (dump_file, " previously known state: %s\n", | |
8b4ee73c | 1158 | pure_const_names[fs->state_previously_known]); |
fc94a528 | 1159 | if (fs->looping) |
1160 | fprintf (dump_file," function is locally looping\n"); | |
1161 | if (fs->looping_previously_known) | |
1162 | fprintf (dump_file," function is previously known looping\n"); | |
1163 | if (fs->can_throw) | |
1164 | fprintf (dump_file," function is locally throwing\n"); | |
04c849b3 | 1165 | if (fs->can_free) |
1166 | fprintf (dump_file," function can locally free\n"); | |
fc94a528 | 1167 | } |
7bfefa9d | 1168 | } |
1169 | ||
48e1416a | 1170 | lto_destroy_simple_input_block (file_data, |
1171 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1172 | ib, data, len); |
1173 | } | |
1174 | } | |
1175 | } | |
1176 | ||
355c1f40 | 1177 | /* We only propagate across edges that can throw externally and their callee |
1178 | is not interposable. */ | |
7bfefa9d | 1179 | |
17b28e52 | 1180 | static bool |
355c1f40 | 1181 | ignore_edge_for_nothrow (struct cgraph_edge *e) |
17b28e52 | 1182 | { |
355c1f40 | 1183 | if (!e->can_throw_external || TREE_NOTHROW (e->callee->decl)) |
1184 | return true; | |
1185 | ||
1186 | enum availability avail; | |
8b4ee73c | 1187 | cgraph_node *n = e->callee->function_or_virtual_thunk_symbol (&avail, |
1188 | e->caller); | |
ace7bf06 | 1189 | if (avail <= AVAIL_INTERPOSABLE || TREE_NOTHROW (n->decl)) |
1190 | return true; | |
1191 | return opt_for_fn (e->callee->decl, flag_non_call_exceptions) | |
1192 | && !e->callee->binds_to_current_def_p (e->caller); | |
17b28e52 | 1193 | } |
1194 | ||
b2c2e188 | 1195 | /* Return true if NODE is self recursive function. |
e9de52cc | 1196 | Indirectly recursive functions appears as non-trivial strongly |
1197 | connected components, so we need to care about self recursion | |
1198 | only. */ | |
a1e88032 | 1199 | |
1200 | static bool | |
1201 | self_recursive_p (struct cgraph_node *node) | |
1202 | { | |
1203 | struct cgraph_edge *e; | |
1204 | for (e = node->callees; e; e = e->next_callee) | |
415d1b9a | 1205 | if (e->callee->function_symbol () == node) |
a1e88032 | 1206 | return true; |
1207 | return false; | |
1208 | } | |
1209 | ||
366970c6 | 1210 | /* Return true if N is cdtor that is not const or pure. In this case we may |
1211 | need to remove unreachable function if it is marked const/pure. */ | |
1212 | ||
1213 | static bool | |
1214 | cdtor_p (cgraph_node *n, void *) | |
1215 | { | |
1216 | if (DECL_STATIC_CONSTRUCTOR (n->decl) || DECL_STATIC_DESTRUCTOR (n->decl)) | |
98b8f2a5 | 1217 | return ((!TREE_READONLY (n->decl) && !DECL_PURE_P (n->decl)) |
1218 | || DECL_LOOPING_CONST_OR_PURE_P (n->decl)); | |
366970c6 | 1219 | return false; |
1220 | } | |
1221 | ||
d2c6c2b4 | 1222 | /* We only propagate across edges with non-interposable callee. */ |
1223 | ||
1224 | static bool | |
1225 | ignore_edge_for_pure_const (struct cgraph_edge *e) | |
1226 | { | |
1227 | enum availability avail; | |
8b4ee73c | 1228 | e->callee->function_or_virtual_thunk_symbol (&avail, e->caller); |
d2c6c2b4 | 1229 | return (avail <= AVAIL_INTERPOSABLE); |
1230 | } | |
1231 | ||
1232 | ||
c0240443 | 1233 | /* Produce transitive closure over the callgraph and compute pure/const |
1234 | attributes. */ | |
023a28e1 | 1235 | |
366970c6 | 1236 | static bool |
c0240443 | 1237 | propagate_pure_const (void) |
cb886925 | 1238 | { |
1239 | struct cgraph_node *node; | |
1240 | struct cgraph_node *w; | |
1241 | struct cgraph_node **order = | |
35ee1c66 | 1242 | XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); |
cb886925 | 1243 | int order_pos; |
1244 | int i; | |
1245 | struct ipa_dfs_info * w_info; | |
366970c6 | 1246 | bool remove_p = false; |
aaa36a78 | 1247 | bool has_cdtor; |
cb886925 | 1248 | |
d2c6c2b4 | 1249 | order_pos = ipa_reduced_postorder (order, true, false, |
1250 | ignore_edge_for_pure_const); | |
f7d118a9 | 1251 | if (dump_file) |
1252 | { | |
415d1b9a | 1253 | cgraph_node::dump_cgraph (dump_file); |
48669653 | 1254 | ipa_print_order (dump_file, "reduced", order, order_pos); |
f7d118a9 | 1255 | } |
1256 | ||
9d75589a | 1257 | /* Propagate the local information through the call graph to produce |
f7d118a9 | 1258 | the global information. All the nodes within a cycle will have |
1259 | the same info so we collapse cycles first. Then we can do the | |
1260 | propagation in one pass from the leaves to the roots. */ | |
1261 | for (i = 0; i < order_pos; i++ ) | |
1262 | { | |
1263 | enum pure_const_state_e pure_const_state = IPA_CONST; | |
9c2a0c05 | 1264 | bool looping = false; |
54157bf1 | 1265 | int count = 0; |
f7d118a9 | 1266 | node = order[i]; |
1267 | ||
02774f2d | 1268 | if (node->alias) |
8c1fce46 | 1269 | continue; |
1270 | ||
fc94a528 | 1271 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1272 | fprintf (dump_file, "Starting cycle\n"); | |
1273 | ||
f7d118a9 | 1274 | /* Find the worst state for any node in the cycle. */ |
1275 | w = node; | |
023a28e1 | 1276 | while (w && pure_const_state != IPA_NEITHER) |
f7d118a9 | 1277 | { |
b5cebd44 | 1278 | struct cgraph_edge *e; |
023a28e1 | 1279 | struct cgraph_edge *ie; |
1280 | int i; | |
51ce5652 | 1281 | struct ipa_ref *ref = NULL; |
023a28e1 | 1282 | |
f7d118a9 | 1283 | funct_state w_l = get_function_state (w); |
fc94a528 | 1284 | if (dump_file && (dump_flags & TDF_DETAILS)) |
0e388735 | 1285 | fprintf (dump_file, " Visiting %s state:%s looping %i\n", |
1286 | w->dump_name (), | |
fc94a528 | 1287 | pure_const_names[w_l->pure_const_state], |
1288 | w_l->looping); | |
f7d118a9 | 1289 | |
8b4ee73c | 1290 | /* First merge in function body properties. |
1291 | We are safe to pass NULL as FROM and TO because we will take care | |
1292 | of possible interposition when walking callees. */ | |
023a28e1 | 1293 | worse_state (&pure_const_state, &looping, |
8b4ee73c | 1294 | w_l->pure_const_state, w_l->looping, |
1295 | NULL, NULL); | |
023a28e1 | 1296 | if (pure_const_state == IPA_NEITHER) |
1297 | break; | |
1298 | ||
b5cebd44 | 1299 | count++; |
1300 | ||
023a28e1 | 1301 | /* We consider recursive cycles as possibly infinite. |
1302 | This might be relaxed since infinite recursion leads to stack | |
1303 | overflow. */ | |
b5cebd44 | 1304 | if (count > 1) |
1305 | looping = true; | |
48e1416a | 1306 | |
023a28e1 | 1307 | /* Now walk the edges and merge in callee properties. */ |
d2c6c2b4 | 1308 | for (e = w->callees; e && pure_const_state != IPA_NEITHER; |
1309 | e = e->next_callee) | |
f7d118a9 | 1310 | { |
b2c2e188 | 1311 | enum availability avail; |
cfd85d03 | 1312 | struct cgraph_node *y = e->callee-> |
8b4ee73c | 1313 | function_or_virtual_thunk_symbol (&avail, |
1314 | e->caller); | |
fc94a528 | 1315 | enum pure_const_state_e edge_state = IPA_CONST; |
1316 | bool edge_looping = false; | |
54157bf1 | 1317 | |
fc94a528 | 1318 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1319 | { | |
0e388735 | 1320 | fprintf (dump_file, " Call to %s", |
1321 | e->callee->dump_name ()); | |
fc94a528 | 1322 | } |
415d1b9a | 1323 | if (avail > AVAIL_INTERPOSABLE) |
f7d118a9 | 1324 | { |
b5cebd44 | 1325 | funct_state y_l = get_function_state (y); |
fc94a528 | 1326 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1327 | { | |
1328 | fprintf (dump_file, | |
1329 | " state:%s looping:%i\n", | |
1330 | pure_const_names[y_l->pure_const_state], | |
1331 | y_l->looping); | |
1332 | } | |
4c170941 | 1333 | if (y_l->pure_const_state > IPA_PURE |
35ee1c66 | 1334 | && e->cannot_lead_to_return_p ()) |
fc94a528 | 1335 | { |
1336 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
023a28e1 | 1337 | fprintf (dump_file, |
1338 | " Ignoring side effects" | |
1339 | " -> pure, looping\n"); | |
fc94a528 | 1340 | edge_state = IPA_PURE; |
1341 | edge_looping = true; | |
1342 | } | |
1343 | else | |
1344 | { | |
1345 | edge_state = y_l->pure_const_state; | |
1346 | edge_looping = y_l->looping; | |
1347 | } | |
f7d118a9 | 1348 | } |
a53e7471 | 1349 | else if (special_builtin_state (&edge_state, &edge_looping, |
02774f2d | 1350 | y->decl)) |
7dd42908 | 1351 | ; |
ef378c27 | 1352 | else |
023a28e1 | 1353 | state_from_flags (&edge_state, &edge_looping, |
02774f2d | 1354 | flags_from_decl_or_type (y->decl), |
35ee1c66 | 1355 | e->cannot_lead_to_return_p ()); |
023a28e1 | 1356 | |
1357 | /* Merge the results with what we already know. */ | |
1358 | better_state (&edge_state, &edge_looping, | |
1359 | w_l->state_previously_known, | |
1360 | w_l->looping_previously_known); | |
1361 | worse_state (&pure_const_state, &looping, | |
8b4ee73c | 1362 | edge_state, edge_looping, e->caller, e->callee); |
023a28e1 | 1363 | if (pure_const_state == IPA_NEITHER) |
1364 | break; | |
1365 | } | |
ef378c27 | 1366 | |
023a28e1 | 1367 | /* Now process the indirect call. */ |
d2c6c2b4 | 1368 | for (ie = w->indirect_calls; |
1369 | ie && pure_const_state != IPA_NEITHER; ie = ie->next_callee) | |
023a28e1 | 1370 | { |
1371 | enum pure_const_state_e edge_state = IPA_CONST; | |
1372 | bool edge_looping = false; | |
4c170941 | 1373 | |
023a28e1 | 1374 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1375 | fprintf (dump_file, " Indirect call"); | |
1376 | state_from_flags (&edge_state, &edge_looping, | |
1377 | ie->indirect_info->ecf_flags, | |
35ee1c66 | 1378 | ie->cannot_lead_to_return_p ()); |
023a28e1 | 1379 | /* Merge the results with what we already know. */ |
1380 | better_state (&edge_state, &edge_looping, | |
1381 | w_l->state_previously_known, | |
1382 | w_l->looping_previously_known); | |
1383 | worse_state (&pure_const_state, &looping, | |
8b4ee73c | 1384 | edge_state, edge_looping, NULL, NULL); |
fc94a528 | 1385 | if (pure_const_state == IPA_NEITHER) |
1386 | break; | |
f7d118a9 | 1387 | } |
023a28e1 | 1388 | |
1389 | /* And finally all loads and stores. */ | |
d2c6c2b4 | 1390 | for (i = 0; w->iterate_reference (i, ref) |
1391 | && pure_const_state != IPA_NEITHER; i++) | |
023a28e1 | 1392 | { |
1393 | enum pure_const_state_e ref_state = IPA_CONST; | |
1394 | bool ref_looping = false; | |
1395 | switch (ref->use) | |
1396 | { | |
1397 | case IPA_REF_LOAD: | |
1398 | /* readonly reads are safe. */ | |
51ce5652 | 1399 | if (TREE_READONLY (ref->referred->decl)) |
023a28e1 | 1400 | break; |
1401 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1402 | fprintf (dump_file, " nonreadonly global var read\n"); | |
1403 | ref_state = IPA_PURE; | |
1404 | break; | |
1405 | case IPA_REF_STORE: | |
51ce5652 | 1406 | if (ref->cannot_lead_to_return ()) |
023a28e1 | 1407 | break; |
1408 | ref_state = IPA_NEITHER; | |
1409 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1410 | fprintf (dump_file, " global var write\n"); | |
1411 | break; | |
1412 | case IPA_REF_ADDR: | |
058a1b7a | 1413 | case IPA_REF_CHKP: |
023a28e1 | 1414 | break; |
5cb7c8cf | 1415 | default: |
1416 | gcc_unreachable (); | |
023a28e1 | 1417 | } |
1418 | better_state (&ref_state, &ref_looping, | |
1419 | w_l->state_previously_known, | |
1420 | w_l->looping_previously_known); | |
1421 | worse_state (&pure_const_state, &looping, | |
8b4ee73c | 1422 | ref_state, ref_looping, NULL, NULL); |
023a28e1 | 1423 | if (pure_const_state == IPA_NEITHER) |
1424 | break; | |
1425 | } | |
02774f2d | 1426 | w_info = (struct ipa_dfs_info *) w->aux; |
f7d118a9 | 1427 | w = w_info->next_cycle; |
1428 | } | |
fc94a528 | 1429 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1430 | fprintf (dump_file, "Result %s looping %i\n", | |
1431 | pure_const_names [pure_const_state], | |
1432 | looping); | |
f7d118a9 | 1433 | |
04c849b3 | 1434 | /* Find the worst state of can_free for any node in the cycle. */ |
1435 | bool can_free = false; | |
1436 | w = node; | |
1437 | while (w && !can_free) | |
1438 | { | |
1439 | struct cgraph_edge *e; | |
1440 | funct_state w_l = get_function_state (w); | |
1441 | ||
1442 | if (w_l->can_free | |
1443 | || w->get_availability () == AVAIL_INTERPOSABLE | |
1444 | || w->indirect_calls) | |
1445 | can_free = true; | |
1446 | ||
1447 | for (e = w->callees; e && !can_free; e = e->next_callee) | |
1448 | { | |
1449 | enum availability avail; | |
cfd85d03 | 1450 | struct cgraph_node *y = e->callee-> |
8b4ee73c | 1451 | function_or_virtual_thunk_symbol (&avail, |
1452 | e->caller); | |
04c849b3 | 1453 | |
1454 | if (avail > AVAIL_INTERPOSABLE) | |
1455 | can_free = get_function_state (y)->can_free; | |
1456 | else | |
1457 | can_free = true; | |
1458 | } | |
1459 | w_info = (struct ipa_dfs_info *) w->aux; | |
1460 | w = w_info->next_cycle; | |
1461 | } | |
1462 | ||
f7d118a9 | 1463 | /* Copy back the region's pure_const_state which is shared by |
1464 | all nodes in the region. */ | |
1465 | w = node; | |
1466 | while (w) | |
1467 | { | |
1468 | funct_state w_l = get_function_state (w); | |
b5cebd44 | 1469 | enum pure_const_state_e this_state = pure_const_state; |
1470 | bool this_looping = looping; | |
f7d118a9 | 1471 | |
04c849b3 | 1472 | w_l->can_free = can_free; |
1473 | w->nonfreeing_fn = !can_free; | |
1474 | if (!can_free && dump_file) | |
1475 | fprintf (dump_file, "Function found not to call free: %s\n", | |
1476 | w->name ()); | |
1477 | ||
df9b545b | 1478 | if (w_l->state_previously_known != IPA_NEITHER |
1479 | && this_state > w_l->state_previously_known) | |
4c170941 | 1480 | { |
1481 | this_state = w_l->state_previously_known; | |
d2c6c2b4 | 1482 | if (this_state == IPA_NEITHER) |
1483 | this_looping = w_l->looping_previously_known; | |
4c170941 | 1484 | } |
a1e88032 | 1485 | if (!this_looping && self_recursive_p (w)) |
1486 | this_looping = true; | |
df9b545b | 1487 | if (!w_l->looping_previously_known) |
1488 | this_looping = false; | |
cb886925 | 1489 | |
b5cebd44 | 1490 | /* All nodes within a cycle share the same info. */ |
1491 | w_l->pure_const_state = this_state; | |
1492 | w_l->looping = this_looping; | |
1493 | ||
ce2d198d | 1494 | /* Inline clones share declaration with their offline copies; |
1495 | do not modify their declarations since the offline copy may | |
1496 | be different. */ | |
1497 | if (!w->global.inlined_to) | |
1498 | switch (this_state) | |
1499 | { | |
1500 | case IPA_CONST: | |
1501 | if (!TREE_READONLY (w->decl)) | |
1502 | { | |
1503 | warn_function_const (w->decl, !this_looping); | |
1504 | if (dump_file) | |
1505 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
1506 | this_looping ? "looping " : "", | |
1507 | w->name ()); | |
1508 | } | |
aaa36a78 | 1509 | /* Turning constructor or destructor to non-looping const/pure |
1510 | enables us to possibly remove the function completely. */ | |
1511 | if (this_looping) | |
1512 | has_cdtor = false; | |
1513 | else | |
1514 | has_cdtor = w->call_for_symbol_and_aliases (cdtor_p, | |
1515 | NULL, true); | |
1516 | if (w->set_const_flag (true, this_looping)) | |
1517 | { | |
1518 | if (dump_file) | |
1519 | fprintf (dump_file, | |
1520 | "Declaration updated to be %sconst: %s\n", | |
1521 | this_looping ? "looping " : "", | |
1522 | w->name ()); | |
1523 | remove_p |= has_cdtor; | |
1524 | } | |
ce2d198d | 1525 | break; |
48e1416a | 1526 | |
ce2d198d | 1527 | case IPA_PURE: |
1528 | if (!DECL_PURE_P (w->decl)) | |
1529 | { | |
1530 | warn_function_pure (w->decl, !this_looping); | |
1531 | if (dump_file) | |
1532 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
1533 | this_looping ? "looping " : "", | |
1534 | w->name ()); | |
1535 | } | |
aaa36a78 | 1536 | if (this_looping) |
1537 | has_cdtor = false; | |
1538 | else | |
1539 | has_cdtor = w->call_for_symbol_and_aliases (cdtor_p, | |
1540 | NULL, true); | |
1541 | if (w->set_pure_flag (true, this_looping)) | |
1542 | { | |
1543 | if (dump_file) | |
1544 | fprintf (dump_file, | |
1545 | "Declaration updated to be %spure: %s\n", | |
1546 | this_looping ? "looping " : "", | |
1547 | w->name ()); | |
1548 | remove_p |= has_cdtor; | |
1549 | } | |
ce2d198d | 1550 | break; |
48e1416a | 1551 | |
ce2d198d | 1552 | default: |
1553 | break; | |
1554 | } | |
02774f2d | 1555 | w_info = (struct ipa_dfs_info *) w->aux; |
17b28e52 | 1556 | w = w_info->next_cycle; |
1557 | } | |
1558 | } | |
1559 | ||
7771d558 | 1560 | ipa_free_postorder_info (); |
c0240443 | 1561 | free (order); |
366970c6 | 1562 | return remove_p; |
c0240443 | 1563 | } |
1564 | ||
1565 | /* Produce transitive closure over the callgraph and compute nothrow | |
1566 | attributes. */ | |
1567 | ||
1568 | static void | |
1569 | propagate_nothrow (void) | |
1570 | { | |
1571 | struct cgraph_node *node; | |
1572 | struct cgraph_node *w; | |
1573 | struct cgraph_node **order = | |
35ee1c66 | 1574 | XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); |
c0240443 | 1575 | int order_pos; |
1576 | int i; | |
1577 | struct ipa_dfs_info * w_info; | |
1578 | ||
355c1f40 | 1579 | order_pos = ipa_reduced_postorder (order, true, false, |
1580 | ignore_edge_for_nothrow); | |
17b28e52 | 1581 | if (dump_file) |
1582 | { | |
415d1b9a | 1583 | cgraph_node::dump_cgraph (dump_file); |
7771d558 | 1584 | ipa_print_order (dump_file, "reduced for nothrow", order, order_pos); |
17b28e52 | 1585 | } |
c0240443 | 1586 | |
9d75589a | 1587 | /* Propagate the local information through the call graph to produce |
17b28e52 | 1588 | the global information. All the nodes within a cycle will have |
1589 | the same info so we collapse cycles first. Then we can do the | |
1590 | propagation in one pass from the leaves to the roots. */ | |
1591 | for (i = 0; i < order_pos; i++ ) | |
1592 | { | |
1593 | bool can_throw = false; | |
1594 | node = order[i]; | |
1595 | ||
02774f2d | 1596 | if (node->alias) |
8c1fce46 | 1597 | continue; |
1598 | ||
17b28e52 | 1599 | /* Find the worst state for any node in the cycle. */ |
1600 | w = node; | |
b2c90c54 | 1601 | while (w && !can_throw) |
17b28e52 | 1602 | { |
023a28e1 | 1603 | struct cgraph_edge *e, *ie; |
17b28e52 | 1604 | |
355c1f40 | 1605 | if (!TREE_NOTHROW (w->decl)) |
17b28e52 | 1606 | { |
355c1f40 | 1607 | funct_state w_l = get_function_state (w); |
17b28e52 | 1608 | |
355c1f40 | 1609 | if (w_l->can_throw |
1610 | || w->get_availability () == AVAIL_INTERPOSABLE) | |
1611 | can_throw = true; | |
1612 | ||
1613 | for (e = w->callees; e && !can_throw; e = e->next_callee) | |
17b28e52 | 1614 | { |
355c1f40 | 1615 | enum availability avail; |
1616 | ||
1617 | if (!e->can_throw_external || TREE_NOTHROW (e->callee->decl)) | |
1618 | continue; | |
1619 | ||
1620 | struct cgraph_node *y = e->callee-> | |
ace7bf06 | 1621 | function_or_virtual_thunk_symbol (&avail, |
1622 | e->caller); | |
17b28e52 | 1623 | |
355c1f40 | 1624 | /* We can use info about the callee only if we know it can |
ace7bf06 | 1625 | not be interposed. |
1626 | When callee is compiled with non-call exceptions we also | |
1627 | must check that the declaration is bound to current | |
1628 | body as other semantically equivalent body may still | |
1629 | throw. */ | |
355c1f40 | 1630 | if (avail <= AVAIL_INTERPOSABLE |
1631 | || (!TREE_NOTHROW (y->decl) | |
ace7bf06 | 1632 | && (get_function_state (y)->can_throw |
1633 | || (opt_for_fn (y->decl, flag_non_call_exceptions) | |
1634 | && !e->callee->binds_to_current_def_p (w))))) | |
17b28e52 | 1635 | can_throw = true; |
1636 | } | |
355c1f40 | 1637 | for (ie = w->indirect_calls; ie && !can_throw; |
1638 | ie = ie->next_callee) | |
1639 | if (ie->can_throw_external | |
1640 | && !(ie->indirect_info->ecf_flags & ECF_NOTHROW)) | |
1641 | can_throw = true; | |
17b28e52 | 1642 | } |
02774f2d | 1643 | w_info = (struct ipa_dfs_info *) w->aux; |
17b28e52 | 1644 | w = w_info->next_cycle; |
1645 | } | |
1646 | ||
1647 | /* Copy back the region's pure_const_state which is shared by | |
1648 | all nodes in the region. */ | |
1649 | w = node; | |
1650 | while (w) | |
1651 | { | |
ecfab407 | 1652 | funct_state w_l = get_function_state (w); |
02774f2d | 1653 | if (!can_throw && !TREE_NOTHROW (w->decl)) |
b5cebd44 | 1654 | { |
ce2d198d | 1655 | /* Inline clones share declaration with their offline copies; |
1656 | do not modify their declarations since the offline copy may | |
1657 | be different. */ | |
1658 | if (!w->global.inlined_to) | |
1659 | { | |
415d1b9a | 1660 | w->set_nothrow_flag (true); |
ce2d198d | 1661 | if (dump_file) |
1662 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
1663 | w->name ()); | |
1664 | } | |
f7d118a9 | 1665 | } |
02774f2d | 1666 | else if (can_throw && !TREE_NOTHROW (w->decl)) |
ecfab407 | 1667 | w_l->can_throw = true; |
02774f2d | 1668 | w_info = (struct ipa_dfs_info *) w->aux; |
f7d118a9 | 1669 | w = w_info->next_cycle; |
1670 | } | |
1671 | } | |
1672 | ||
7771d558 | 1673 | ipa_free_postorder_info (); |
f7d118a9 | 1674 | free (order); |
c0240443 | 1675 | } |
1676 | ||
1677 | ||
1678 | /* Produce the global information by preforming a transitive closure | |
1679 | on the local information that was produced by generate_summary. */ | |
1680 | ||
415309e2 | 1681 | unsigned int |
1682 | pass_ipa_pure_const:: | |
1683 | execute (function *) | |
c0240443 | 1684 | { |
1685 | struct cgraph_node *node; | |
366970c6 | 1686 | bool remove_p; |
c0240443 | 1687 | |
35ee1c66 | 1688 | symtab->remove_cgraph_insertion_hook (function_insertion_hook_holder); |
1689 | symtab->remove_cgraph_duplication_hook (node_duplication_hook_holder); | |
1690 | symtab->remove_cgraph_removal_hook (node_removal_hook_holder); | |
c0240443 | 1691 | |
1692 | /* Nothrow makes more function to not lead to return and improve | |
1693 | later analysis. */ | |
1694 | propagate_nothrow (); | |
366970c6 | 1695 | remove_p = propagate_pure_const (); |
c0240443 | 1696 | |
1697 | /* Cleanup. */ | |
c6d207aa | 1698 | FOR_EACH_FUNCTION (node) |
c0240443 | 1699 | if (has_function_state (node)) |
1700 | free (get_function_state (node)); | |
f1f41a6c | 1701 | funct_state_vec.release (); |
366970c6 | 1702 | return remove_p ? TODO_remove_functions : 0; |
f7d118a9 | 1703 | } |
1704 | ||
1705 | static bool | |
1706 | gate_pure_const (void) | |
1707 | { | |
d1f68cd8 | 1708 | return flag_ipa_pure_const || in_lto_p; |
f7d118a9 | 1709 | } |
1710 | ||
415309e2 | 1711 | pass_ipa_pure_const::pass_ipa_pure_const(gcc::context *ctxt) |
1712 | : ipa_opt_pass_d(pass_data_ipa_pure_const, ctxt, | |
1713 | pure_const_generate_summary, /* generate_summary */ | |
1714 | pure_const_write_summary, /* write_summary */ | |
1715 | pure_const_read_summary, /* read_summary */ | |
1716 | NULL, /* write_optimization_summary */ | |
1717 | NULL, /* read_optimization_summary */ | |
1718 | NULL, /* stmt_fixup */ | |
1719 | 0, /* function_transform_todo_flags_start */ | |
1720 | NULL, /* function_transform */ | |
1721 | NULL), /* variable_transform */ | |
1722 | init_p(false), | |
1723 | function_insertion_hook_holder(NULL), | |
1724 | node_duplication_hook_holder(NULL), | |
1725 | node_removal_hook_holder(NULL) | |
f7d118a9 | 1726 | { |
415309e2 | 1727 | } |
cbe8bda8 | 1728 | |
1729 | ipa_opt_pass_d * | |
1730 | make_pass_ipa_pure_const (gcc::context *ctxt) | |
1731 | { | |
1732 | return new pass_ipa_pure_const (ctxt); | |
1733 | } | |
1734 | ||
2c06958d | 1735 | /* Return true if function should be skipped for local pure const analysis. */ |
b5cebd44 | 1736 | |
2c06958d | 1737 | static bool |
1738 | skip_function_for_local_pure_const (struct cgraph_node *node) | |
b5cebd44 | 1739 | { |
8b4ee73c | 1740 | /* Because we do not schedule pass_fixup_cfg over whole program after early |
1741 | optimizations we must not promote functions that are called by already | |
1742 | processed functions. */ | |
b5cebd44 | 1743 | |
1744 | if (function_called_by_processed_nodes_p ()) | |
1745 | { | |
1746 | if (dump_file) | |
1747 | fprintf (dump_file, "Function called in recursive cycle; ignoring\n"); | |
2c06958d | 1748 | return true; |
b5cebd44 | 1749 | } |
aaa36a78 | 1750 | /* Save some work and do not analyze functions which are interposable and |
1751 | do not have any non-interposable aliases. */ | |
1752 | if (node->get_availability () <= AVAIL_INTERPOSABLE | |
1753 | && !node->has_aliases_p ()) | |
b5cebd44 | 1754 | { |
1755 | if (dump_file) | |
8b4ee73c | 1756 | fprintf (dump_file, |
aaa36a78 | 1757 | "Function is interposable; not analyzing.\n"); |
2c06958d | 1758 | return true; |
b5cebd44 | 1759 | } |
2c06958d | 1760 | return false; |
1761 | } | |
1762 | ||
1763 | /* Simple local pass for pure const discovery reusing the analysis from | |
1764 | ipa_pure_const. This pass is effective when executed together with | |
1765 | other optimization passes in early optimization pass queue. */ | |
b5cebd44 | 1766 | |
7620bc82 | 1767 | namespace { |
1768 | ||
1769 | const pass_data pass_data_local_pure_const = | |
65b0537f | 1770 | { |
1771 | GIMPLE_PASS, /* type */ | |
1772 | "local-pure-const", /* name */ | |
1773 | OPTGROUP_NONE, /* optinfo_flags */ | |
65b0537f | 1774 | TV_IPA_PURE_CONST, /* tv_id */ |
1775 | 0, /* properties_required */ | |
1776 | 0, /* properties_provided */ | |
1777 | 0, /* properties_destroyed */ | |
1778 | 0, /* todo_flags_start */ | |
1779 | 0, /* todo_flags_finish */ | |
1780 | }; | |
1781 | ||
7620bc82 | 1782 | class pass_local_pure_const : public gimple_opt_pass |
65b0537f | 1783 | { |
1784 | public: | |
1785 | pass_local_pure_const (gcc::context *ctxt) | |
1786 | : gimple_opt_pass (pass_data_local_pure_const, ctxt) | |
1787 | {} | |
1788 | ||
1789 | /* opt_pass methods: */ | |
1790 | opt_pass * clone () { return new pass_local_pure_const (m_ctxt); } | |
1791 | virtual bool gate (function *) { return gate_pure_const (); } | |
1792 | virtual unsigned int execute (function *); | |
1793 | ||
1794 | }; // class pass_local_pure_const | |
1795 | ||
1796 | unsigned int | |
1797 | pass_local_pure_const::execute (function *fun) | |
2c06958d | 1798 | { |
1799 | bool changed = false; | |
1800 | funct_state l; | |
1801 | bool skip; | |
1802 | struct cgraph_node *node; | |
1803 | ||
415d1b9a | 1804 | node = cgraph_node::get (current_function_decl); |
2c06958d | 1805 | skip = skip_function_for_local_pure_const (node); |
60722a03 | 1806 | |
2c06958d | 1807 | if (!warn_suggest_attribute_const |
1808 | && !warn_suggest_attribute_pure | |
1809 | && skip) | |
1810 | return 0; | |
e0933141 | 1811 | |
ab3db708 | 1812 | l = analyze_function (node, false); |
1813 | ||
1814 | /* Do NORETURN discovery. */ | |
e0933141 | 1815 | if (!skip && !TREE_THIS_VOLATILE (current_function_decl) |
65b0537f | 1816 | && EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (fun)->preds) == 0) |
e0933141 | 1817 | { |
65b0537f | 1818 | warn_function_noreturn (fun->decl); |
e0933141 | 1819 | if (dump_file) |
65b0537f | 1820 | fprintf (dump_file, "Function found to be noreturn: %s\n", |
1821 | current_function_name ()); | |
e0933141 | 1822 | |
1823 | /* Update declaration and reduce profile to executed once. */ | |
1824 | TREE_THIS_VOLATILE (current_function_decl) = 1; | |
1825 | if (node->frequency > NODE_FREQUENCY_EXECUTED_ONCE) | |
65b0537f | 1826 | node->frequency = NODE_FREQUENCY_EXECUTED_ONCE; |
e0933141 | 1827 | |
1828 | changed = true; | |
1829 | } | |
ef378c27 | 1830 | |
b5cebd44 | 1831 | switch (l->pure_const_state) |
1832 | { | |
1833 | case IPA_CONST: | |
1834 | if (!TREE_READONLY (current_function_decl)) | |
1835 | { | |
2c06958d | 1836 | warn_function_const (current_function_decl, !l->looping); |
b5cebd44 | 1837 | if (dump_file) |
1838 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
1839 | l->looping ? "looping " : "", | |
9631926a | 1840 | current_function_name ()); |
b5cebd44 | 1841 | } |
1842 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
1843 | && !l->looping) | |
1844 | { | |
b5cebd44 | 1845 | if (dump_file) |
1846 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 1847 | current_function_name ()); |
b5cebd44 | 1848 | } |
aaa36a78 | 1849 | if (!skip && node->set_const_flag (true, l->looping)) |
1850 | { | |
1851 | if (dump_file) | |
1852 | fprintf (dump_file, "Declaration updated to be %sconst: %s\n", | |
1853 | l->looping ? "looping " : "", | |
1854 | current_function_name ()); | |
1855 | changed = true; | |
1856 | } | |
b5cebd44 | 1857 | break; |
1858 | ||
1859 | case IPA_PURE: | |
2c06958d | 1860 | if (!DECL_PURE_P (current_function_decl)) |
b5cebd44 | 1861 | { |
2c06958d | 1862 | warn_function_pure (current_function_decl, !l->looping); |
b5cebd44 | 1863 | if (dump_file) |
1864 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
1865 | l->looping ? "looping " : "", | |
9631926a | 1866 | current_function_name ()); |
b5cebd44 | 1867 | } |
1868 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
1869 | && !l->looping) | |
1870 | { | |
b5cebd44 | 1871 | if (dump_file) |
1872 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 1873 | current_function_name ()); |
b5cebd44 | 1874 | } |
aaa36a78 | 1875 | if (!skip && node->set_pure_flag (true, l->looping)) |
1876 | { | |
1877 | if (dump_file) | |
1878 | fprintf (dump_file, "Declaration updated to be %spure: %s\n", | |
1879 | l->looping ? "looping " : "", | |
1880 | current_function_name ()); | |
1881 | changed = true; | |
1882 | } | |
b5cebd44 | 1883 | break; |
1884 | ||
1885 | default: | |
1886 | break; | |
1887 | } | |
1888 | if (!l->can_throw && !TREE_NOTHROW (current_function_decl)) | |
1889 | { | |
415d1b9a | 1890 | node->set_nothrow_flag (true); |
b5cebd44 | 1891 | changed = true; |
1892 | if (dump_file) | |
1893 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
9631926a | 1894 | current_function_name ()); |
b5cebd44 | 1895 | } |
dd045aee | 1896 | free (l); |
b5cebd44 | 1897 | if (changed) |
1898 | return execute_fixup_cfg (); | |
1899 | else | |
1900 | return 0; | |
1901 | } | |
1902 | ||
7620bc82 | 1903 | } // anon namespace |
1904 | ||
cbe8bda8 | 1905 | gimple_opt_pass * |
1906 | make_pass_local_pure_const (gcc::context *ctxt) | |
1907 | { | |
1908 | return new pass_local_pure_const (ctxt); | |
1909 | } | |
64641360 | 1910 | |
1911 | /* Emit noreturn warnings. */ | |
1912 | ||
7620bc82 | 1913 | namespace { |
1914 | ||
1915 | const pass_data pass_data_warn_function_noreturn = | |
64641360 | 1916 | { |
1917 | GIMPLE_PASS, /* type */ | |
1918 | "*warn_function_noreturn", /* name */ | |
1919 | OPTGROUP_NONE, /* optinfo_flags */ | |
64641360 | 1920 | TV_NONE, /* tv_id */ |
1921 | PROP_cfg, /* properties_required */ | |
1922 | 0, /* properties_provided */ | |
1923 | 0, /* properties_destroyed */ | |
1924 | 0, /* todo_flags_start */ | |
1925 | 0, /* todo_flags_finish */ | |
1926 | }; | |
1927 | ||
7620bc82 | 1928 | class pass_warn_function_noreturn : public gimple_opt_pass |
64641360 | 1929 | { |
1930 | public: | |
1931 | pass_warn_function_noreturn (gcc::context *ctxt) | |
1932 | : gimple_opt_pass (pass_data_warn_function_noreturn, ctxt) | |
1933 | {} | |
1934 | ||
1935 | /* opt_pass methods: */ | |
31315c24 | 1936 | virtual bool gate (function *) { return warn_suggest_attribute_noreturn; } |
65b0537f | 1937 | virtual unsigned int execute (function *fun) |
1938 | { | |
1939 | if (!TREE_THIS_VOLATILE (current_function_decl) | |
1940 | && EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (fun)->preds) == 0) | |
1941 | warn_function_noreturn (current_function_decl); | |
1942 | return 0; | |
1943 | } | |
64641360 | 1944 | |
1945 | }; // class pass_warn_function_noreturn | |
1946 | ||
7620bc82 | 1947 | } // anon namespace |
1948 | ||
64641360 | 1949 | gimple_opt_pass * |
1950 | make_pass_warn_function_noreturn (gcc::context *ctxt) | |
1951 | { | |
1952 | return new pass_warn_function_noreturn (ctxt); | |
1953 | } | |
73594827 | 1954 | |
1955 | /* Simple local pass for pure const discovery reusing the analysis from | |
1956 | ipa_pure_const. This pass is effective when executed together with | |
1957 | other optimization passes in early optimization pass queue. */ | |
1958 | ||
7620bc82 | 1959 | namespace { |
1960 | ||
1961 | const pass_data pass_data_nothrow = | |
73594827 | 1962 | { |
1963 | GIMPLE_PASS, /* type */ | |
1964 | "nothrow", /* name */ | |
1965 | OPTGROUP_NONE, /* optinfo_flags */ | |
1966 | TV_IPA_PURE_CONST, /* tv_id */ | |
1967 | 0, /* properties_required */ | |
1968 | 0, /* properties_provided */ | |
1969 | 0, /* properties_destroyed */ | |
1970 | 0, /* todo_flags_start */ | |
1971 | 0, /* todo_flags_finish */ | |
1972 | }; | |
1973 | ||
7620bc82 | 1974 | class pass_nothrow : public gimple_opt_pass |
73594827 | 1975 | { |
1976 | public: | |
1977 | pass_nothrow (gcc::context *ctxt) | |
1978 | : gimple_opt_pass (pass_data_nothrow, ctxt) | |
1979 | {} | |
1980 | ||
1981 | /* opt_pass methods: */ | |
1982 | opt_pass * clone () { return new pass_nothrow (m_ctxt); } | |
1983 | virtual bool gate (function *) { return optimize; } | |
1984 | virtual unsigned int execute (function *); | |
1985 | ||
1986 | }; // class pass_nothrow | |
1987 | ||
1988 | unsigned int | |
1989 | pass_nothrow::execute (function *) | |
1990 | { | |
1991 | struct cgraph_node *node; | |
1992 | basic_block this_block; | |
1993 | ||
1994 | if (TREE_NOTHROW (current_function_decl)) | |
1995 | return 0; | |
1996 | ||
1997 | node = cgraph_node::get (current_function_decl); | |
1998 | ||
1999 | /* We run during lowering, we can not really use availability yet. */ | |
2000 | if (cgraph_node::get (current_function_decl)->get_availability () | |
2001 | <= AVAIL_INTERPOSABLE) | |
2002 | { | |
2003 | if (dump_file) | |
2004 | fprintf (dump_file, "Function is interposable;" | |
2005 | " not analyzing.\n"); | |
2006 | return true; | |
2007 | } | |
2008 | ||
2009 | FOR_EACH_BB_FN (this_block, cfun) | |
2010 | { | |
2011 | for (gimple_stmt_iterator gsi = gsi_start_bb (this_block); | |
2012 | !gsi_end_p (gsi); | |
2013 | gsi_next (&gsi)) | |
2014 | if (stmt_can_throw_external (gsi_stmt (gsi))) | |
2015 | { | |
2016 | if (is_gimple_call (gsi_stmt (gsi))) | |
2017 | { | |
2018 | tree callee_t = gimple_call_fndecl (gsi_stmt (gsi)); | |
2019 | if (callee_t && recursive_call_p (current_function_decl, | |
2020 | callee_t)) | |
2021 | continue; | |
2022 | } | |
2023 | ||
2024 | if (dump_file) | |
2025 | { | |
2026 | fprintf (dump_file, "Statement can throw: "); | |
1ffa4346 | 2027 | print_gimple_stmt (dump_file, gsi_stmt (gsi), 0); |
73594827 | 2028 | } |
2029 | return 0; | |
2030 | } | |
2031 | } | |
2032 | ||
2033 | node->set_nothrow_flag (true); | |
fd499010 | 2034 | |
2035 | bool cfg_changed = false; | |
2036 | if (self_recursive_p (node)) | |
2037 | FOR_EACH_BB_FN (this_block, cfun) | |
2038 | if (gimple *g = last_stmt (this_block)) | |
2039 | if (is_gimple_call (g)) | |
2040 | { | |
2041 | tree callee_t = gimple_call_fndecl (g); | |
2042 | if (callee_t | |
2043 | && recursive_call_p (current_function_decl, callee_t) | |
2044 | && maybe_clean_eh_stmt (g) | |
2045 | && gimple_purge_dead_eh_edges (this_block)) | |
2046 | cfg_changed = true; | |
2047 | } | |
2048 | ||
73594827 | 2049 | if (dump_file) |
2050 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
2051 | current_function_name ()); | |
fd499010 | 2052 | return cfg_changed ? TODO_cleanup_cfg : 0; |
73594827 | 2053 | } |
2054 | ||
7620bc82 | 2055 | } // anon namespace |
2056 | ||
73594827 | 2057 | gimple_opt_pass * |
2058 | make_pass_nothrow (gcc::context *ctxt) | |
2059 | { | |
2060 | return new pass_nothrow (ctxt); | |
2061 | } |