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ea900239 | 1 | /* Callgraph based analysis of static variables. |
8d9254fc | 2 | Copyright (C) 2004-2020 Free Software Foundation, Inc. |
ea900239 DB |
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 | |
9dcd6f09 | 9 | Software Foundation; either version 3, or (at your option) any later |
ea900239 DB |
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/>. */ | |
ea900239 | 20 | |
fa10beec RW |
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). | |
ea900239 DB |
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" | |
c7131fb2 | 37 | #include "backend.h" |
957060b5 | 38 | #include "target.h" |
ea900239 | 39 | #include "tree.h" |
c7131fb2 | 40 | #include "gimple.h" |
957060b5 AM |
41 | #include "tree-pass.h" |
42 | #include "tree-streamer.h" | |
43 | #include "cgraph.h" | |
44 | #include "diagnostic.h" | |
d8a2d370 | 45 | #include "calls.h" |
60393bbc | 46 | #include "cfganal.h" |
2fb9a547 | 47 | #include "tree-eh.h" |
5be5c238 AM |
48 | #include "gimple-iterator.h" |
49 | #include "gimple-walk.h" | |
442b4905 | 50 | #include "tree-cfg.h" |
e28030cf | 51 | #include "tree-ssa-loop-niter.h" |
ea900239 | 52 | #include "langhooks.h" |
ea900239 | 53 | #include "ipa-utils.h" |
cf835838 | 54 | #include "gimple-pretty-print.h" |
2de58650 JH |
55 | #include "cfgloop.h" |
56 | #include "tree-scalar-evolution.h" | |
5dc16b19 MLI |
57 | #include "intl.h" |
58 | #include "opts.h" | |
0fab169b PK |
59 | #include "ssa.h" |
60 | #include "alloc-pool.h" | |
61 | #include "symbol-summary.h" | |
62 | #include "ipa-prop.h" | |
63 | #include "ipa-fnsummary.h" | |
ea900239 DB |
64 | |
65 | /* Lattice values for const and pure functions. Everything starts out | |
66 | being const, then may drop to pure and then neither depending on | |
67 | what is found. */ | |
68 | enum pure_const_state_e | |
69 | { | |
70 | IPA_CONST, | |
71 | IPA_PURE, | |
72 | IPA_NEITHER | |
73 | }; | |
74 | ||
0fab169b PK |
75 | static const char *pure_const_names[3] = {"const", "pure", "neither"}; |
76 | ||
77 | enum malloc_state_e | |
78 | { | |
79 | STATE_MALLOC_TOP, | |
80 | STATE_MALLOC, | |
81 | STATE_MALLOC_BOTTOM | |
82 | }; | |
83 | ||
84 | static const char *malloc_state_names[] = {"malloc_top", "malloc", "malloc_bottom"}; | |
d56026c2 | 85 | |
812dbce5 JH |
86 | /* Holder for the const_state. There is one of these per function |
87 | decl. */ | |
36330f82 | 88 | class funct_state_d |
ea900239 | 89 | { |
36330f82 ML |
90 | public: |
91 | funct_state_d (): pure_const_state (IPA_NEITHER), | |
92 | state_previously_known (IPA_NEITHER), looping_previously_known (true), | |
93 | looping (true), can_throw (true), can_free (true), | |
94 | malloc_state (STATE_MALLOC_BOTTOM) {} | |
95 | ||
96 | funct_state_d (const funct_state_d &s): pure_const_state (s.pure_const_state), | |
97 | state_previously_known (s.state_previously_known), | |
98 | looping_previously_known (s.looping_previously_known), | |
99 | looping (s.looping), can_throw (s.can_throw), can_free (s.can_free), | |
100 | malloc_state (s.malloc_state) {} | |
101 | ||
812dbce5 | 102 | /* See above. */ |
ea900239 | 103 | enum pure_const_state_e pure_const_state; |
33977f81 | 104 | /* What user set here; we can be always sure about this. */ |
b8698a0f L |
105 | enum pure_const_state_e state_previously_known; |
106 | bool looping_previously_known; | |
812dbce5 JH |
107 | |
108 | /* True if the function could possibly infinite loop. There are a | |
109 | lot of ways that this could be determined. We are pretty | |
110 | conservative here. While it is possible to cse pure and const | |
111 | calls, it is not legal to have dce get rid of the call if there | |
112 | is a possibility that the call could infinite loop since this is | |
113 | a behavioral change. */ | |
becfd6e5 | 114 | bool looping; |
812dbce5 | 115 | |
33977f81 | 116 | bool can_throw; |
8413ca87 JJ |
117 | |
118 | /* If function can call free, munmap or otherwise make previously | |
119 | non-trapping memory accesses trapping. */ | |
120 | bool can_free; | |
0fab169b PK |
121 | |
122 | enum malloc_state_e malloc_state; | |
ea900239 DB |
123 | }; |
124 | ||
99b1c316 | 125 | typedef class funct_state_d * funct_state; |
ea900239 | 126 | |
812dbce5 JH |
127 | /* The storage of the funct_state is abstracted because there is the |
128 | possibility that it may be desirable to move this to the cgraph | |
b8698a0f | 129 | local info. */ |
812dbce5 | 130 | |
db30281f ML |
131 | class funct_state_summary_t: |
132 | public fast_function_summary <funct_state_d *, va_heap> | |
36330f82 ML |
133 | { |
134 | public: | |
135 | funct_state_summary_t (symbol_table *symtab): | |
db30281f | 136 | fast_function_summary <funct_state_d *, va_heap> (symtab) {} |
36330f82 ML |
137 | |
138 | virtual void insert (cgraph_node *, funct_state_d *state); | |
139 | virtual void duplicate (cgraph_node *src_node, cgraph_node *dst_node, | |
140 | funct_state_d *src_data, | |
141 | funct_state_d *dst_data); | |
142 | }; | |
812dbce5 | 143 | |
36330f82 | 144 | static funct_state_summary_t *funct_state_summaries = NULL; |
812dbce5 | 145 | |
3edf64aa DM |
146 | static bool gate_pure_const (void); |
147 | ||
17795822 TS |
148 | namespace { |
149 | ||
150 | const pass_data pass_data_ipa_pure_const = | |
3edf64aa DM |
151 | { |
152 | IPA_PASS, /* type */ | |
153 | "pure-const", /* name */ | |
154 | OPTGROUP_NONE, /* optinfo_flags */ | |
155 | TV_IPA_PURE_CONST, /* tv_id */ | |
156 | 0, /* properties_required */ | |
157 | 0, /* properties_provided */ | |
158 | 0, /* properties_destroyed */ | |
159 | 0, /* todo_flags_start */ | |
160 | 0, /* todo_flags_finish */ | |
161 | }; | |
162 | ||
17795822 | 163 | class pass_ipa_pure_const : public ipa_opt_pass_d |
3edf64aa DM |
164 | { |
165 | public: | |
166 | pass_ipa_pure_const(gcc::context *ctxt); | |
167 | ||
168 | /* opt_pass methods: */ | |
169 | bool gate (function *) { return gate_pure_const (); } | |
170 | unsigned int execute (function *fun); | |
171 | ||
172 | void register_hooks (void); | |
173 | ||
174 | private: | |
175 | bool init_p; | |
3edf64aa DM |
176 | }; // class pass_ipa_pure_const |
177 | ||
17795822 TS |
178 | } // anon namespace |
179 | ||
5dc16b19 MLI |
180 | /* Try to guess if function body will always be visible to compiler |
181 | when compiling the call and whether compiler will be able | |
182 | to propagate the information by itself. */ | |
183 | ||
184 | static bool | |
185 | function_always_visible_to_compiler_p (tree decl) | |
186 | { | |
12b9f3ac JH |
187 | return (!TREE_PUBLIC (decl) || DECL_DECLARED_INLINE_P (decl) |
188 | || DECL_COMDAT (decl)); | |
5dc16b19 MLI |
189 | } |
190 | ||
191 | /* Emit suggestion about attribute ATTRIB_NAME for DECL. KNOWN_FINITE | |
192 | is true if the function is known to be finite. The diagnostic is | |
6e2830c3 | 193 | controlled by OPTION. WARNED_ABOUT is a hash_set<tree> unique for |
5dc16b19 MLI |
194 | OPTION, this function may initialize it and it is always returned |
195 | by the function. */ | |
196 | ||
6e2830c3 | 197 | static hash_set<tree> * |
5dc16b19 | 198 | suggest_attribute (int option, tree decl, bool known_finite, |
6e2830c3 | 199 | hash_set<tree> *warned_about, |
5dc16b19 MLI |
200 | const char * attrib_name) |
201 | { | |
fa5baeed | 202 | if (!option_enabled (option, lang_hooks.option_lang_mask (), &global_options)) |
5dc16b19 MLI |
203 | return warned_about; |
204 | if (TREE_THIS_VOLATILE (decl) | |
205 | || (known_finite && function_always_visible_to_compiler_p (decl))) | |
206 | return warned_about; | |
207 | ||
208 | if (!warned_about) | |
6e2830c3 TS |
209 | warned_about = new hash_set<tree>; |
210 | if (warned_about->contains (decl)) | |
5dc16b19 | 211 | return warned_about; |
6e2830c3 | 212 | warned_about->add (decl); |
5dc16b19 MLI |
213 | warning_at (DECL_SOURCE_LOCATION (decl), |
214 | option, | |
215 | known_finite | |
2f6f187a DM |
216 | ? G_("function might be candidate for attribute %qs") |
217 | : G_("function might be candidate for attribute %qs" | |
218 | " if it is known to return normally"), attrib_name); | |
5dc16b19 MLI |
219 | return warned_about; |
220 | } | |
221 | ||
222 | /* Emit suggestion about __attribute_((pure)) for DECL. KNOWN_FINITE | |
223 | is true if the function is known to be finite. */ | |
224 | ||
225 | static void | |
226 | warn_function_pure (tree decl, bool known_finite) | |
227 | { | |
a594cff3 MS |
228 | /* Declaring a void function pure makes no sense and is diagnosed |
229 | by -Wattributes because calling it would have no effect. */ | |
230 | if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) | |
231 | return; | |
5dc16b19 | 232 | |
a594cff3 MS |
233 | static hash_set<tree> *warned_about; |
234 | warned_about | |
5dc16b19 MLI |
235 | = suggest_attribute (OPT_Wsuggest_attribute_pure, decl, |
236 | known_finite, warned_about, "pure"); | |
237 | } | |
238 | ||
239 | /* Emit suggestion about __attribute_((const)) for DECL. KNOWN_FINITE | |
240 | is true if the function is known to be finite. */ | |
241 | ||
242 | static void | |
243 | warn_function_const (tree decl, bool known_finite) | |
244 | { | |
a594cff3 MS |
245 | /* Declaring a void function const makes no sense is diagnosed |
246 | by -Wattributes because calling it would have no effect. */ | |
247 | if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) | |
248 | return; | |
249 | ||
6e2830c3 | 250 | static hash_set<tree> *warned_about; |
a594cff3 | 251 | warned_about |
5dc16b19 MLI |
252 | = suggest_attribute (OPT_Wsuggest_attribute_const, decl, |
253 | known_finite, warned_about, "const"); | |
254 | } | |
7ea6b6cf | 255 | |
0fab169b PK |
256 | /* Emit suggestion about __attribute__((malloc)) for DECL. */ |
257 | ||
258 | static void | |
259 | warn_function_malloc (tree decl) | |
260 | { | |
261 | static hash_set<tree> *warned_about; | |
262 | warned_about | |
263 | = suggest_attribute (OPT_Wsuggest_attribute_malloc, decl, | |
0fac5f2a | 264 | true, warned_about, "malloc"); |
0fab169b PK |
265 | } |
266 | ||
267 | /* Emit suggestion about __attribute__((noreturn)) for DECL. */ | |
268 | ||
c1bf2a39 | 269 | static void |
7ea6b6cf JH |
270 | warn_function_noreturn (tree decl) |
271 | { | |
a48018b5 ML |
272 | tree original_decl = decl; |
273 | ||
6e2830c3 | 274 | static hash_set<tree> *warned_about; |
d45eae79 SL |
275 | if (!lang_hooks.missing_noreturn_ok_p (decl) |
276 | && targetm.warn_func_return (decl)) | |
7ea6b6cf | 277 | warned_about |
a48018b5 | 278 | = suggest_attribute (OPT_Wsuggest_attribute_noreturn, original_decl, |
7ea6b6cf JH |
279 | true, warned_about, "noreturn"); |
280 | } | |
df92c640 | 281 | |
12b9f3ac JH |
282 | void |
283 | warn_function_cold (tree decl) | |
284 | { | |
285 | tree original_decl = decl; | |
286 | ||
12b9f3ac JH |
287 | static hash_set<tree> *warned_about; |
288 | warned_about | |
289 | = suggest_attribute (OPT_Wsuggest_attribute_cold, original_decl, | |
290 | true, warned_about, "cold"); | |
291 | } | |
292 | ||
fa10beec | 293 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
ea900239 DB |
294 | variable T is legal in a function that is either pure or const. */ |
295 | ||
b8698a0f L |
296 | static inline void |
297 | check_decl (funct_state local, | |
f10ea640 | 298 | tree t, bool checking_write, bool ipa) |
ea900239 | 299 | { |
ea900239 DB |
300 | /* Do not want to do anything with volatile except mark any |
301 | function that uses one to be not const or pure. */ | |
b8698a0f L |
302 | if (TREE_THIS_VOLATILE (t)) |
303 | { | |
ea900239 | 304 | local->pure_const_state = IPA_NEITHER; |
33977f81 | 305 | if (dump_file) |
75622c9e | 306 | fprintf (dump_file, " Volatile operand is not const/pure\n"); |
ea900239 DB |
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 | ||
33977f81 JH |
314 | /* If the variable has the "used" attribute, treat it as if it had a |
315 | been touched by the devil. */ | |
b42186f1 | 316 | if (DECL_PRESERVE_P (t)) |
33977f81 JH |
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 | ||
f10ea640 JH |
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 | ||
ea900239 DB |
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. */ | |
b8698a0f | 332 | if (checking_write) |
eb80272a ST |
333 | { |
334 | local->pure_const_state = IPA_NEITHER; | |
33977f81 JH |
335 | if (dump_file) |
336 | fprintf (dump_file, " static/global memory write is not const/pure\n"); | |
eb80272a ST |
337 | return; |
338 | } | |
ea900239 DB |
339 | |
340 | if (DECL_EXTERNAL (t) || TREE_PUBLIC (t)) | |
341 | { | |
33977f81 | 342 | /* Readonly reads are safe. */ |
bd78c6d5 | 343 | if (TREE_READONLY (t)) |
33977f81 | 344 | return; /* Read of a constant, do not change the function state. */ |
b8698a0f | 345 | else |
ea900239 | 346 | { |
33977f81 JH |
347 | if (dump_file) |
348 | fprintf (dump_file, " global memory read is not const\n"); | |
ea900239 DB |
349 | /* Just a regular read. */ |
350 | if (local->pure_const_state == IPA_CONST) | |
351 | local->pure_const_state = IPA_PURE; | |
352 | } | |
353 | } | |
33977f81 JH |
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 | } | |
ea900239 DB |
367 | } |
368 | ||
ea900239 | 369 | |
33977f81 JH |
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. */ | |
ea900239 | 372 | |
b8698a0f | 373 | static inline void |
346ef3fa | 374 | check_op (funct_state local, tree t, bool checking_write) |
ea900239 | 375 | { |
3c1832c3 JH |
376 | t = get_base_address (t); |
377 | if (t && TREE_THIS_VOLATILE (t)) | |
ea900239 | 378 | { |
346ef3fa RG |
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 | } | |
3c1832c3 | 384 | else if (t |
70f34814 | 385 | && (INDIRECT_REF_P (t) || TREE_CODE (t) == MEM_REF) |
3c1832c3 JH |
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 | } | |
346ef3fa RG |
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; | |
ea900239 DB |
406 | } |
407 | } | |
408 | ||
f10ea640 JH |
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)) | |
75622c9e | 420 | fprintf (dump_file, " looping\n"); |
f10ea640 JH |
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)) | |
df92c640 | 444 | fprintf (dump_file, " neither\n"); |
f10ea640 JH |
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); | |
b0d04a5f | 465 | *state = state2; |
f10ea640 JH |
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 | |
cc950f98 JH |
472 | into STATE and LOOPING worse of the two variants. |
473 | N is the actual node called. */ | |
f10ea640 JH |
474 | |
475 | static inline void | |
476 | worse_state (enum pure_const_state_e *state, bool *looping, | |
cc950f98 JH |
477 | enum pure_const_state_e state2, bool looping2, |
478 | struct symtab_node *from, | |
479 | struct symtab_node *to) | |
f10ea640 | 480 | { |
cc950f98 JH |
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 " | |
3629ff8a | 503 | "bind to current def.\n", to->dump_name ()); |
cc950f98 JH |
504 | state2 = IPA_PURE; |
505 | } | |
f10ea640 JH |
506 | *state = MAX (*state, state2); |
507 | *looping = MAX (*looping, looping2); | |
508 | } | |
509 | ||
61502ca8 | 510 | /* Recognize special cases of builtins that are by themselves not pure or const |
0a42aa4e JH |
511 | but function using them is. */ |
512 | static bool | |
9e97ff61 | 513 | special_builtin_state (enum pure_const_state_e *state, bool *looping, |
813b70a1 | 514 | tree callee) |
0a42aa4e JH |
515 | { |
516 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
517 | switch (DECL_FUNCTION_CODE (callee)) | |
518 | { | |
813b70a1 JJ |
519 | case BUILT_IN_RETURN: |
520 | case BUILT_IN_UNREACHABLE: | |
521 | CASE_BUILT_IN_ALLOCA: | |
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_ARGS: | |
531 | case BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT: | |
532 | case BUILT_IN_ASAN_AFTER_DYNAMIC_INIT: | |
533 | *looping = false; | |
534 | *state = IPA_CONST; | |
535 | return true; | |
536 | case BUILT_IN_PREFETCH: | |
537 | *looping = true; | |
538 | *state = IPA_CONST; | |
539 | return true; | |
540 | default: | |
541 | break; | |
0a42aa4e JH |
542 | } |
543 | return false; | |
544 | } | |
545 | ||
ea900239 DB |
546 | /* Check the parameters of a function call to CALL_EXPR to see if |
547 | there are any references in the parameters that are not allowed for | |
548 | pure or const functions. Also check to see if this is either an | |
549 | indirect call, a call outside the compilation unit, or has special | |
550 | attributes that may also effect the purity. The CALL_EXPR node for | |
551 | the entire call expression. */ | |
552 | ||
553 | static void | |
538dd0b7 | 554 | check_call (funct_state local, gcall *call, bool ipa) |
ea900239 | 555 | { |
726a989a | 556 | int flags = gimple_call_flags (call); |
33977f81 | 557 | tree callee_t = gimple_call_fndecl (call); |
36bbc05d | 558 | bool possibly_throws = stmt_could_throw_p (cfun, call); |
33977f81 | 559 | bool possibly_throws_externally = (possibly_throws |
36bbc05d | 560 | && stmt_can_throw_external (cfun, call)); |
ea900239 | 561 | |
33977f81 JH |
562 | if (possibly_throws) |
563 | { | |
564 | unsigned int i; | |
565 | for (i = 0; i < gimple_num_ops (call); i++) | |
566 | if (gimple_op (call, i) | |
567 | && tree_could_throw_p (gimple_op (call, i))) | |
568 | { | |
8f4f502f | 569 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
33977f81 JH |
570 | { |
571 | if (dump_file) | |
572 | fprintf (dump_file, " operand can throw; looping\n"); | |
573 | local->looping = true; | |
574 | } | |
575 | if (possibly_throws_externally) | |
576 | { | |
577 | if (dump_file) | |
578 | fprintf (dump_file, " operand can throw externally\n"); | |
579 | local->can_throw = true; | |
580 | } | |
581 | } | |
582 | } | |
b8698a0f | 583 | |
ea900239 DB |
584 | /* The const and pure flags are set by a variety of places in the |
585 | compiler (including here). If someone has already set the flags | |
586 | for the callee, (such as for some of the builtins) we will use | |
b8698a0f L |
587 | them, otherwise we will compute our own information. |
588 | ||
ea900239 DB |
589 | Const and pure functions have less clobber effects than other |
590 | functions so we process these first. Otherwise if it is a call | |
591 | outside the compilation unit or an indirect call we punt. This | |
592 | leaves local calls which will be processed by following the call | |
b8698a0f | 593 | graph. */ |
ea900239 DB |
594 | if (callee_t) |
595 | { | |
0a42aa4e JH |
596 | enum pure_const_state_e call_state; |
597 | bool call_looping; | |
598 | ||
8413ca87 JJ |
599 | if (gimple_call_builtin_p (call, BUILT_IN_NORMAL) |
600 | && !nonfreeing_call_p (call)) | |
601 | local->can_free = true; | |
602 | ||
9e97ff61 | 603 | if (special_builtin_state (&call_state, &call_looping, callee_t)) |
0a42aa4e JH |
604 | { |
605 | worse_state (&local->pure_const_state, &local->looping, | |
cc950f98 JH |
606 | call_state, call_looping, |
607 | NULL, NULL); | |
0a42aa4e JH |
608 | return; |
609 | } | |
ea900239 DB |
610 | /* When bad things happen to bad functions, they cannot be const |
611 | or pure. */ | |
612 | if (setjmp_call_p (callee_t)) | |
becfd6e5 | 613 | { |
33977f81 JH |
614 | if (dump_file) |
615 | fprintf (dump_file, " setjmp is not const/pure\n"); | |
616 | local->looping = true; | |
becfd6e5 | 617 | local->pure_const_state = IPA_NEITHER; |
becfd6e5 | 618 | } |
ea900239 DB |
619 | |
620 | if (DECL_BUILT_IN_CLASS (callee_t) == BUILT_IN_NORMAL) | |
621 | switch (DECL_FUNCTION_CODE (callee_t)) | |
622 | { | |
623 | case BUILT_IN_LONGJMP: | |
624 | case BUILT_IN_NONLOCAL_GOTO: | |
33977f81 | 625 | if (dump_file) |
813b70a1 JJ |
626 | fprintf (dump_file, |
627 | " longjmp and nonlocal goto is not const/pure\n"); | |
ea900239 | 628 | local->pure_const_state = IPA_NEITHER; |
813b70a1 | 629 | local->looping = true; |
ea900239 DB |
630 | break; |
631 | default: | |
632 | break; | |
633 | } | |
634 | } | |
8413ca87 JJ |
635 | else if (gimple_call_internal_p (call) && !nonfreeing_call_p (call)) |
636 | local->can_free = true; | |
ea900239 | 637 | |
33977f81 | 638 | /* When not in IPA mode, we can still handle self recursion. */ |
fc11f321 JH |
639 | if (!ipa && callee_t |
640 | && recursive_call_p (current_function_decl, callee_t)) | |
5dc16b19 MLI |
641 | { |
642 | if (dump_file) | |
643 | fprintf (dump_file, " Recursive call can loop.\n"); | |
644 | local->looping = true; | |
645 | } | |
61502ca8 | 646 | /* Either callee is unknown or we are doing local analysis. |
c59f5d1b JH |
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 | |
d40790c8 JJ |
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)) | |
ea900239 | 653 | { |
f10ea640 JH |
654 | enum pure_const_state_e call_state; |
655 | bool call_looping; | |
8f4f502f | 656 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
33977f81 JH |
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 | { | |
1d65f45c RH |
666 | fprintf (dump_file, " can throw externally to lp %i\n", |
667 | lookup_stmt_eh_lp (call)); | |
33977f81 JH |
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 | } | |
f10ea640 JH |
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, | |
cc950f98 | 681 | call_state, call_looping, NULL, NULL); |
ea900239 | 682 | } |
33977f81 | 683 | /* Direct functions calls are handled by IPA propagation. */ |
ea900239 DB |
684 | } |
685 | ||
f10ea640 | 686 | /* Wrapper around check_decl for loads in local more. */ |
346ef3fa RG |
687 | |
688 | static bool | |
355fe088 | 689 | check_load (gimple *, tree op, tree, void *data) |
346ef3fa RG |
690 | { |
691 | if (DECL_P (op)) | |
f10ea640 | 692 | check_decl ((funct_state)data, op, false, false); |
346ef3fa RG |
693 | else |
694 | check_op ((funct_state)data, op, false); | |
695 | return false; | |
696 | } | |
697 | ||
f10ea640 | 698 | /* Wrapper around check_decl for stores in local more. */ |
346ef3fa RG |
699 | |
700 | static bool | |
355fe088 | 701 | check_store (gimple *, tree op, tree, void *data) |
346ef3fa RG |
702 | { |
703 | if (DECL_P (op)) | |
f10ea640 JH |
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 | |
355fe088 | 713 | check_ipa_load (gimple *, tree op, tree, void *data) |
f10ea640 JH |
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 | |
355fe088 | 725 | check_ipa_store (gimple *, tree op, tree, void *data) |
f10ea640 JH |
726 | { |
727 | if (DECL_P (op)) | |
728 | check_decl ((funct_state)data, op, true, true); | |
346ef3fa RG |
729 | else |
730 | check_op ((funct_state)data, op, true); | |
731 | return false; | |
732 | } | |
733 | ||
5006671f RG |
734 | /* Look into pointer pointed to by GSIP and figure out what interesting side |
735 | effects it has. */ | |
33977f81 JH |
736 | static void |
737 | check_stmt (gimple_stmt_iterator *gsip, funct_state local, bool ipa) | |
ea900239 | 738 | { |
355fe088 | 739 | gimple *stmt = gsi_stmt (*gsip); |
ea900239 | 740 | |
b5b8b0ac AO |
741 | if (is_gimple_debug (stmt)) |
742 | return; | |
743 | ||
38147a2a JH |
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 | ||
33977f81 | 754 | if (dump_file) |
ea900239 | 755 | { |
33977f81 | 756 | fprintf (dump_file, " scanning: "); |
ef6cb4c7 | 757 | print_gimple_stmt (dump_file, stmt, 0); |
33977f81 | 758 | } |
5006671f | 759 | |
ace018f9 RG |
760 | if (gimple_has_volatile_ops (stmt) |
761 | && !gimple_clobber_p (stmt)) | |
4e89a3fa RG |
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 | ||
346ef3fa | 768 | /* Look for loads and stores. */ |
f10ea640 JH |
769 | walk_stmt_load_store_ops (stmt, local, |
770 | ipa ? check_ipa_load : check_load, | |
771 | ipa ? check_ipa_store : check_store); | |
33977f81 JH |
772 | |
773 | if (gimple_code (stmt) != GIMPLE_CALL | |
36bbc05d | 774 | && stmt_could_throw_p (cfun, stmt)) |
33977f81 | 775 | { |
8f4f502f | 776 | if (cfun->can_throw_non_call_exceptions) |
33977f81 JH |
777 | { |
778 | if (dump_file) | |
425b784f | 779 | fprintf (dump_file, " can throw; looping\n"); |
33977f81 JH |
780 | local->looping = true; |
781 | } | |
36bbc05d | 782 | if (stmt_can_throw_external (cfun, stmt)) |
33977f81 JH |
783 | { |
784 | if (dump_file) | |
425b784f | 785 | fprintf (dump_file, " can throw externally\n"); |
33977f81 JH |
786 | local->can_throw = true; |
787 | } | |
425b784f JH |
788 | else |
789 | if (dump_file) | |
790 | fprintf (dump_file, " can throw\n"); | |
726a989a | 791 | } |
726a989a RB |
792 | switch (gimple_code (stmt)) |
793 | { | |
33977f81 | 794 | case GIMPLE_CALL: |
538dd0b7 | 795 | check_call (local, as_a <gcall *> (stmt), ipa); |
ea900239 | 796 | break; |
726a989a | 797 | case GIMPLE_LABEL: |
538dd0b7 | 798 | if (DECL_NONLOCAL (gimple_label_label (as_a <glabel *> (stmt)))) |
ea900239 | 799 | /* Target of long jump. */ |
becfd6e5 | 800 | { |
33977f81 | 801 | if (dump_file) |
425b784f | 802 | fprintf (dump_file, " nonlocal label is not const/pure\n"); |
becfd6e5 | 803 | local->pure_const_state = IPA_NEITHER; |
becfd6e5 | 804 | } |
ea900239 | 805 | break; |
726a989a | 806 | case GIMPLE_ASM: |
538dd0b7 | 807 | if (gimple_asm_clobbers_memory_p (as_a <gasm *> (stmt))) |
33977f81 | 808 | { |
edcdea5b | 809 | if (dump_file) |
425b784f | 810 | fprintf (dump_file, " memory asm clobber is not const/pure\n"); |
edcdea5b NF |
811 | /* Abandon all hope, ye who enter here. */ |
812 | local->pure_const_state = IPA_NEITHER; | |
8413ca87 | 813 | local->can_free = true; |
33977f81 | 814 | } |
538dd0b7 | 815 | if (gimple_asm_volatile_p (as_a <gasm *> (stmt))) |
33977f81 JH |
816 | { |
817 | if (dump_file) | |
425b784f | 818 | fprintf (dump_file, " volatile is not const/pure\n"); |
33977f81 JH |
819 | /* Abandon all hope, ye who enter here. */ |
820 | local->pure_const_state = IPA_NEITHER; | |
8413ca87 JJ |
821 | local->looping = true; |
822 | local->can_free = true; | |
33977f81 JH |
823 | } |
824 | return; | |
ea900239 DB |
825 | default: |
826 | break; | |
827 | } | |
ea900239 DB |
828 | } |
829 | ||
0fab169b PK |
830 | /* Check that RETVAL is used only in STMT and in comparisons against 0. |
831 | RETVAL is return value of the function and STMT is return stmt. */ | |
832 | ||
833 | static bool | |
834 | check_retval_uses (tree retval, gimple *stmt) | |
835 | { | |
836 | imm_use_iterator use_iter; | |
837 | gimple *use_stmt; | |
838 | ||
839 | FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, retval) | |
840 | if (gcond *cond = dyn_cast<gcond *> (use_stmt)) | |
841 | { | |
842 | tree op2 = gimple_cond_rhs (cond); | |
843 | if (!integer_zerop (op2)) | |
844 | RETURN_FROM_IMM_USE_STMT (use_iter, false); | |
845 | } | |
846 | else if (gassign *ga = dyn_cast<gassign *> (use_stmt)) | |
847 | { | |
848 | enum tree_code code = gimple_assign_rhs_code (ga); | |
849 | if (TREE_CODE_CLASS (code) != tcc_comparison) | |
850 | RETURN_FROM_IMM_USE_STMT (use_iter, false); | |
851 | if (!integer_zerop (gimple_assign_rhs2 (ga))) | |
852 | RETURN_FROM_IMM_USE_STMT (use_iter, false); | |
853 | } | |
854 | else if (is_gimple_debug (use_stmt)) | |
855 | ; | |
856 | else if (use_stmt != stmt) | |
857 | RETURN_FROM_IMM_USE_STMT (use_iter, false); | |
858 | ||
859 | return true; | |
860 | } | |
861 | ||
862 | /* malloc_candidate_p() checks if FUN can possibly be annotated with malloc | |
863 | attribute. Currently this function does a very conservative analysis. | |
864 | FUN is considered to be a candidate if | |
865 | 1) It returns a value of pointer type. | |
866 | 2) SSA_NAME_DEF_STMT (return_value) is either a function call or | |
867 | a phi, and element of phi is either NULL or | |
868 | SSA_NAME_DEF_STMT(element) is function call. | |
869 | 3) The return-value has immediate uses only within comparisons (gcond or gassign) | |
870 | and return_stmt (and likewise a phi arg has immediate use only within comparison | |
871 | or the phi stmt). */ | |
872 | ||
0fab169b PK |
873 | #define DUMP_AND_RETURN(reason) \ |
874 | { \ | |
875 | if (dump_file && (dump_flags & TDF_DETAILS)) \ | |
a8c80d03 | 876 | fprintf (dump_file, "\n%s is not a malloc candidate, reason: %s\n", \ |
3629ff8a | 877 | (node->dump_name ()), (reason)); \ |
0fab169b PK |
878 | return false; \ |
879 | } | |
880 | ||
9a471714 | 881 | static bool |
4882e5ba RB |
882 | malloc_candidate_p_1 (function *fun, tree retval, gimple *ret_stmt, bool ipa, |
883 | bitmap visited) | |
9a471714 PK |
884 | { |
885 | cgraph_node *node = cgraph_node::get_create (fun->decl); | |
4882e5ba RB |
886 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (retval))) |
887 | return true; | |
9a471714 PK |
888 | |
889 | if (!check_retval_uses (retval, ret_stmt)) | |
890 | DUMP_AND_RETURN("Return value has uses outside return stmt" | |
891 | " and comparisons against 0.") | |
892 | ||
893 | gimple *def = SSA_NAME_DEF_STMT (retval); | |
894 | ||
895 | if (gcall *call_stmt = dyn_cast<gcall *> (def)) | |
896 | { | |
897 | tree callee_decl = gimple_call_fndecl (call_stmt); | |
898 | if (!callee_decl) | |
899 | return false; | |
900 | ||
901 | if (!ipa && !DECL_IS_MALLOC (callee_decl)) | |
902 | DUMP_AND_RETURN("callee_decl does not have malloc attribute for" | |
903 | " non-ipa mode.") | |
904 | ||
905 | cgraph_edge *cs = node->get_edge (call_stmt); | |
906 | if (cs) | |
907 | { | |
908 | ipa_call_summary *es = ipa_call_summaries->get_create (cs); | |
909 | es->is_return_callee_uncaptured = true; | |
910 | } | |
911 | } | |
912 | ||
913 | else if (gphi *phi = dyn_cast<gphi *> (def)) | |
914 | { | |
915 | bool all_args_zero = true; | |
916 | for (unsigned i = 0; i < gimple_phi_num_args (phi); ++i) | |
917 | { | |
918 | tree arg = gimple_phi_arg_def (phi, i); | |
919 | if (integer_zerop (arg)) | |
920 | continue; | |
921 | ||
922 | all_args_zero = false; | |
923 | if (TREE_CODE (arg) != SSA_NAME) | |
924 | DUMP_AND_RETURN ("phi arg is not SSA_NAME."); | |
925 | if (!check_retval_uses (arg, phi)) | |
926 | DUMP_AND_RETURN ("phi arg has uses outside phi" | |
927 | " and comparisons against 0.") | |
928 | ||
929 | gimple *arg_def = SSA_NAME_DEF_STMT (arg); | |
930 | if (is_a<gphi *> (arg_def)) | |
931 | { | |
4882e5ba | 932 | if (!malloc_candidate_p_1 (fun, arg, phi, ipa, visited)) |
9a471714 PK |
933 | DUMP_AND_RETURN ("nested phi fail") |
934 | continue; | |
935 | } | |
936 | ||
937 | gcall *call_stmt = dyn_cast<gcall *> (arg_def); | |
938 | if (!call_stmt) | |
939 | DUMP_AND_RETURN ("phi arg is a not a call_stmt.") | |
940 | ||
941 | tree callee_decl = gimple_call_fndecl (call_stmt); | |
942 | if (!callee_decl) | |
943 | return false; | |
944 | if (!ipa && !DECL_IS_MALLOC (callee_decl)) | |
945 | DUMP_AND_RETURN("callee_decl does not have malloc attribute" | |
946 | " for non-ipa mode.") | |
947 | ||
948 | cgraph_edge *cs = node->get_edge (call_stmt); | |
949 | if (cs) | |
950 | { | |
951 | ipa_call_summary *es = ipa_call_summaries->get_create (cs); | |
952 | es->is_return_callee_uncaptured = true; | |
953 | } | |
954 | } | |
955 | ||
956 | if (all_args_zero) | |
957 | DUMP_AND_RETURN ("Return value is a phi with all args equal to 0.") | |
958 | } | |
959 | ||
960 | else | |
961 | DUMP_AND_RETURN("def_stmt of return value is not a call or phi-stmt.") | |
962 | ||
963 | return true; | |
964 | } | |
965 | ||
966 | static bool | |
967 | malloc_candidate_p (function *fun, bool ipa) | |
968 | { | |
969 | basic_block exit_block = EXIT_BLOCK_PTR_FOR_FN (fun); | |
970 | edge e; | |
971 | edge_iterator ei; | |
972 | cgraph_node *node = cgraph_node::get_create (fun->decl); | |
973 | ||
a8c80d03 PK |
974 | if (EDGE_COUNT (exit_block->preds) == 0 |
975 | || !flag_delete_null_pointer_checks) | |
0fab169b PK |
976 | return false; |
977 | ||
4882e5ba | 978 | auto_bitmap visited; |
0fab169b PK |
979 | FOR_EACH_EDGE (e, ei, exit_block->preds) |
980 | { | |
981 | gimple_stmt_iterator gsi = gsi_last_bb (e->src); | |
982 | greturn *ret_stmt = dyn_cast<greturn *> (gsi_stmt (gsi)); | |
983 | ||
984 | if (!ret_stmt) | |
985 | return false; | |
986 | ||
987 | tree retval = gimple_return_retval (ret_stmt); | |
988 | if (!retval) | |
989 | DUMP_AND_RETURN("No return value.") | |
990 | ||
991 | if (TREE_CODE (retval) != SSA_NAME | |
992 | || TREE_CODE (TREE_TYPE (retval)) != POINTER_TYPE) | |
993 | DUMP_AND_RETURN("Return value is not SSA_NAME or not a pointer type.") | |
994 | ||
4882e5ba | 995 | if (!malloc_candidate_p_1 (fun, retval, ret_stmt, ipa, visited)) |
9a471714 | 996 | return false; |
0fab169b PK |
997 | } |
998 | ||
999 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1000 | fprintf (dump_file, "\nFound %s to be candidate for malloc attribute\n", | |
1001 | IDENTIFIER_POINTER (DECL_NAME (fun->decl))); | |
1002 | return true; | |
0fab169b PK |
1003 | } |
1004 | ||
9a471714 | 1005 | #undef DUMP_AND_RETURN |
812dbce5 | 1006 | |
ea900239 DB |
1007 | /* This is the main routine for finding the reference patterns for |
1008 | global variables within a function FN. */ | |
1009 | ||
33977f81 JH |
1010 | static funct_state |
1011 | analyze_function (struct cgraph_node *fn, bool ipa) | |
ea900239 | 1012 | { |
67348ccc | 1013 | tree decl = fn->decl; |
33977f81 JH |
1014 | funct_state l; |
1015 | basic_block this_block; | |
ea900239 | 1016 | |
99b1c316 | 1017 | l = XCNEW (class funct_state_d); |
33977f81 | 1018 | l->pure_const_state = IPA_CONST; |
f87c9042 JH |
1019 | l->state_previously_known = IPA_NEITHER; |
1020 | l->looping_previously_known = true; | |
33977f81 JH |
1021 | l->looping = false; |
1022 | l->can_throw = false; | |
8413ca87 | 1023 | l->can_free = false; |
c47d0034 | 1024 | state_from_flags (&l->state_previously_known, &l->looping_previously_known, |
67348ccc | 1025 | flags_from_decl_or_type (fn->decl), |
d52f5295 | 1026 | fn->cannot_return_p ()); |
c47d0034 | 1027 | |
67348ccc | 1028 | if (fn->thunk.thunk_p || fn->alias) |
c47d0034 JH |
1029 | { |
1030 | /* Thunk gets propagated through, so nothing interesting happens. */ | |
1031 | gcc_assert (ipa); | |
6cbde2e3 BE |
1032 | if (fn->thunk.thunk_p && fn->thunk.virtual_offset_p) |
1033 | l->pure_const_state = IPA_NEITHER; | |
c47d0034 JH |
1034 | return l; |
1035 | } | |
ea900239 DB |
1036 | |
1037 | if (dump_file) | |
1038 | { | |
b8698a0f | 1039 | fprintf (dump_file, "\n\n local analysis of %s\n ", |
3629ff8a | 1040 | fn->dump_name ()); |
ea900239 | 1041 | } |
b8698a0f | 1042 | |
33977f81 | 1043 | push_cfun (DECL_STRUCT_FUNCTION (decl)); |
b8698a0f | 1044 | |
11cd3bed | 1045 | FOR_EACH_BB_FN (this_block, cfun) |
ea900239 | 1046 | { |
33977f81 JH |
1047 | gimple_stmt_iterator gsi; |
1048 | struct walk_stmt_info wi; | |
ea900239 | 1049 | |
c3284718 | 1050 | memset (&wi, 0, sizeof (wi)); |
33977f81 JH |
1051 | for (gsi = gsi_start_bb (this_block); |
1052 | !gsi_end_p (gsi); | |
1053 | gsi_next (&gsi)) | |
ea900239 | 1054 | { |
33977f81 | 1055 | check_stmt (&gsi, l, ipa); |
8413ca87 JJ |
1056 | if (l->pure_const_state == IPA_NEITHER |
1057 | && l->looping | |
1058 | && l->can_throw | |
1059 | && l->can_free) | |
33977f81 | 1060 | goto end; |
ea900239 DB |
1061 | } |
1062 | } | |
13335ae6 AP |
1063 | |
1064 | end: | |
33977f81 JH |
1065 | if (l->pure_const_state != IPA_NEITHER) |
1066 | { | |
1067 | /* Const functions cannot have back edges (an | |
1068 | indication of possible infinite loop side | |
1069 | effect. */ | |
1070 | if (mark_dfs_back_edges ()) | |
2de58650 | 1071 | { |
7351bcaa | 1072 | /* Preheaders are needed for SCEV to work. |
61502ca8 | 1073 | Simple latches and recorded exits improve chances that loop will |
0d5049b2 RB |
1074 | proved to be finite in testcases such as in loop-15.c |
1075 | and loop-24.c */ | |
1076 | loop_optimizer_init (LOOPS_HAVE_PREHEADERS | |
1077 | | LOOPS_HAVE_SIMPLE_LATCHES | |
7351bcaa | 1078 | | LOOPS_HAVE_RECORDED_EXITS); |
2de58650 JH |
1079 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1080 | flow_loops_dump (dump_file, NULL, 0); | |
1081 | if (mark_irreducible_loops ()) | |
1082 | { | |
1083 | if (dump_file) | |
1084 | fprintf (dump_file, " has irreducible loops\n"); | |
1085 | l->looping = true; | |
1086 | } | |
b8698a0f | 1087 | else |
2de58650 | 1088 | { |
99b1c316 | 1089 | class loop *loop; |
2de58650 | 1090 | scev_initialize (); |
f0bd40b1 | 1091 | FOR_EACH_LOOP (loop, 0) |
2de58650 JH |
1092 | if (!finite_loop_p (loop)) |
1093 | { | |
1094 | if (dump_file) | |
67914693 | 1095 | fprintf (dump_file, " cannot prove finiteness of " |
0d5049b2 | 1096 | "loop %i\n", loop->num); |
2de58650 | 1097 | l->looping =true; |
f0bd40b1 | 1098 | break; |
2de58650 JH |
1099 | } |
1100 | scev_finalize (); | |
1101 | } | |
1102 | loop_optimizer_finalize (); | |
1103 | } | |
33977f81 JH |
1104 | } |
1105 | ||
f10ea640 JH |
1106 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1107 | fprintf (dump_file, " checking previously known:"); | |
f10ea640 JH |
1108 | |
1109 | better_state (&l->pure_const_state, &l->looping, | |
1110 | l->state_previously_known, | |
1111 | l->looping_previously_known); | |
33977f81 JH |
1112 | if (TREE_NOTHROW (decl)) |
1113 | l->can_throw = false; | |
1114 | ||
0fab169b PK |
1115 | l->malloc_state = STATE_MALLOC_BOTTOM; |
1116 | if (DECL_IS_MALLOC (decl)) | |
1117 | l->malloc_state = STATE_MALLOC; | |
1118 | else if (ipa && malloc_candidate_p (DECL_STRUCT_FUNCTION (decl), true)) | |
1119 | l->malloc_state = STATE_MALLOC_TOP; | |
1120 | else if (malloc_candidate_p (DECL_STRUCT_FUNCTION (decl), false)) | |
1121 | l->malloc_state = STATE_MALLOC; | |
1122 | ||
33977f81 | 1123 | pop_cfun (); |
13335ae6 AP |
1124 | if (dump_file) |
1125 | { | |
33977f81 JH |
1126 | if (l->looping) |
1127 | fprintf (dump_file, "Function is locally looping.\n"); | |
1128 | if (l->can_throw) | |
1129 | fprintf (dump_file, "Function is locally throwing.\n"); | |
1130 | if (l->pure_const_state == IPA_CONST) | |
1131 | fprintf (dump_file, "Function is locally const.\n"); | |
1132 | if (l->pure_const_state == IPA_PURE) | |
1133 | fprintf (dump_file, "Function is locally pure.\n"); | |
8413ca87 JJ |
1134 | if (l->can_free) |
1135 | fprintf (dump_file, "Function can locally free.\n"); | |
0fab169b PK |
1136 | if (l->malloc_state == STATE_MALLOC) |
1137 | fprintf (dump_file, "Function is locally malloc.\n"); | |
13335ae6 | 1138 | } |
33977f81 | 1139 | return l; |
ea900239 DB |
1140 | } |
1141 | ||
36330f82 ML |
1142 | void |
1143 | funct_state_summary_t::insert (cgraph_node *node, funct_state_d *state) | |
129a37fc | 1144 | { |
129a37fc JH |
1145 | /* There are some shared nodes, in particular the initializers on |
1146 | static declarations. We do not need to scan them more than once | |
1147 | since all we would be interested in are the addressof | |
1148 | operations. */ | |
cc950f98 | 1149 | if (opt_for_fn (node->decl, flag_ipa_pure_const)) |
e2c9111c | 1150 | { |
36330f82 ML |
1151 | funct_state_d *a = analyze_function (node, true); |
1152 | new (state) funct_state_d (*a); | |
1153 | free (a); | |
e2c9111c JH |
1154 | } |
1155 | } | |
1156 | ||
1157 | /* Called when new clone is inserted to callgraph late. */ | |
1158 | ||
36330f82 | 1159 | void |
33351ff9 | 1160 | funct_state_summary_t::duplicate (cgraph_node *, cgraph_node *dst, |
36330f82 ML |
1161 | funct_state_d *src_data, |
1162 | funct_state_d *dst_data) | |
e2c9111c | 1163 | { |
36330f82 | 1164 | new (dst_data) funct_state_d (*src_data); |
33351ff9 ML |
1165 | if (dst_data->malloc_state == STATE_MALLOC |
1166 | && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (dst->decl)))) | |
1167 | dst_data->malloc_state = STATE_MALLOC_BOTTOM; | |
e2c9111c JH |
1168 | } |
1169 | ||
ea900239 | 1170 | \f |
3edf64aa DM |
1171 | void |
1172 | pass_ipa_pure_const:: | |
d7f09764 | 1173 | register_hooks (void) |
ea900239 | 1174 | { |
d7f09764 DN |
1175 | if (init_p) |
1176 | return; | |
1177 | ||
1178 | init_p = true; | |
ea900239 | 1179 | |
36330f82 | 1180 | funct_state_summaries = new funct_state_summary_t (symtab); |
d7f09764 DN |
1181 | } |
1182 | ||
1183 | ||
1184 | /* Analyze each function in the cgraph to see if it is locally PURE or | |
1185 | CONST. */ | |
1186 | ||
b8698a0f | 1187 | static void |
651df1b2 | 1188 | pure_const_generate_summary (void) |
d7f09764 DN |
1189 | { |
1190 | struct cgraph_node *node; | |
1191 | ||
3edf64aa DM |
1192 | pass_ipa_pure_const *pass = static_cast <pass_ipa_pure_const *> (current_pass); |
1193 | pass->register_hooks (); | |
d7f09764 | 1194 | |
b8698a0f | 1195 | /* Process all of the functions. |
ea900239 | 1196 | |
67914693 | 1197 | We process AVAIL_INTERPOSABLE functions. We cannot use the results |
c59f5d1b | 1198 | by default, but the info can be used at LTO with -fwhole-program or |
61502ca8 | 1199 | when function got cloned and the clone is AVAILABLE. */ |
c59f5d1b | 1200 | |
65c70e6b | 1201 | FOR_EACH_DEFINED_FUNCTION (node) |
cc950f98 | 1202 | if (opt_for_fn (node->decl, flag_ipa_pure_const)) |
36330f82 ML |
1203 | { |
1204 | funct_state_d *a = analyze_function (node, true); | |
1205 | new (funct_state_summaries->get_create (node)) funct_state_d (*a); | |
1206 | free (a); | |
1207 | } | |
812dbce5 JH |
1208 | } |
1209 | ||
d7f09764 DN |
1210 | |
1211 | /* Serialize the ipa info for lto. */ | |
1212 | ||
1213 | static void | |
f27c1867 | 1214 | pure_const_write_summary (void) |
d7f09764 DN |
1215 | { |
1216 | struct cgraph_node *node; | |
1217 | struct lto_simple_output_block *ob | |
1218 | = lto_create_simple_output_block (LTO_section_ipa_pure_const); | |
1219 | unsigned int count = 0; | |
f27c1867 JH |
1220 | lto_symtab_encoder_iterator lsei; |
1221 | lto_symtab_encoder_t encoder; | |
d7f09764 | 1222 | |
f27c1867 JH |
1223 | encoder = lto_get_out_decl_state ()->symtab_node_encoder; |
1224 | ||
1225 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); | |
1226 | lsei_next_function_in_partition (&lsei)) | |
d7f09764 | 1227 | { |
f27c1867 | 1228 | node = lsei_cgraph_node (lsei); |
36330f82 | 1229 | if (node->definition && funct_state_summaries->exists (node)) |
d7f09764 DN |
1230 | count++; |
1231 | } | |
b8698a0f | 1232 | |
412288f1 | 1233 | streamer_write_uhwi_stream (ob->main_stream, count); |
b8698a0f | 1234 | |
d7f09764 | 1235 | /* Process all of the functions. */ |
f27c1867 JH |
1236 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); |
1237 | lsei_next_function_in_partition (&lsei)) | |
d7f09764 | 1238 | { |
f27c1867 | 1239 | node = lsei_cgraph_node (lsei); |
36330f82 ML |
1240 | funct_state_d *fs = funct_state_summaries->get (node); |
1241 | if (node->definition && fs != NULL) | |
d7f09764 | 1242 | { |
2465dcc2 | 1243 | struct bitpack_d bp; |
d7f09764 | 1244 | int node_ref; |
7380e6ef | 1245 | lto_symtab_encoder_t encoder; |
b8698a0f | 1246 | |
7380e6ef | 1247 | encoder = ob->decl_state->symtab_node_encoder; |
67348ccc | 1248 | node_ref = lto_symtab_encoder_encode (encoder, node); |
412288f1 | 1249 | streamer_write_uhwi_stream (ob->main_stream, node_ref); |
b8698a0f | 1250 | |
d7f09764 DN |
1251 | /* Note that flags will need to be read in the opposite |
1252 | order as we are pushing the bitflags into FLAGS. */ | |
2465dcc2 RG |
1253 | bp = bitpack_create (ob->main_stream); |
1254 | bp_pack_value (&bp, fs->pure_const_state, 2); | |
1255 | bp_pack_value (&bp, fs->state_previously_known, 2); | |
1256 | bp_pack_value (&bp, fs->looping_previously_known, 1); | |
1257 | bp_pack_value (&bp, fs->looping, 1); | |
1258 | bp_pack_value (&bp, fs->can_throw, 1); | |
8413ca87 | 1259 | bp_pack_value (&bp, fs->can_free, 1); |
0fab169b | 1260 | bp_pack_value (&bp, fs->malloc_state, 2); |
412288f1 | 1261 | streamer_write_bitpack (&bp); |
d7f09764 DN |
1262 | } |
1263 | } | |
1264 | ||
1265 | lto_destroy_simple_output_block (ob); | |
1266 | } | |
1267 | ||
1268 | ||
1269 | /* Deserialize the ipa info for lto. */ | |
1270 | ||
b8698a0f | 1271 | static void |
d7f09764 DN |
1272 | pure_const_read_summary (void) |
1273 | { | |
1274 | struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); | |
1275 | struct lto_file_decl_data *file_data; | |
1276 | unsigned int j = 0; | |
1277 | ||
3edf64aa DM |
1278 | pass_ipa_pure_const *pass = static_cast <pass_ipa_pure_const *> (current_pass); |
1279 | pass->register_hooks (); | |
1280 | ||
d7f09764 DN |
1281 | while ((file_data = file_data_vec[j++])) |
1282 | { | |
1283 | const char *data; | |
1284 | size_t len; | |
99b1c316 | 1285 | class lto_input_block *ib |
b8698a0f L |
1286 | = lto_create_simple_input_block (file_data, |
1287 | LTO_section_ipa_pure_const, | |
d7f09764 DN |
1288 | &data, &len); |
1289 | if (ib) | |
1290 | { | |
1291 | unsigned int i; | |
412288f1 | 1292 | unsigned int count = streamer_read_uhwi (ib); |
d7f09764 DN |
1293 | |
1294 | for (i = 0; i < count; i++) | |
1295 | { | |
1296 | unsigned int index; | |
1297 | struct cgraph_node *node; | |
2465dcc2 | 1298 | struct bitpack_d bp; |
d7f09764 | 1299 | funct_state fs; |
7380e6ef | 1300 | lto_symtab_encoder_t encoder; |
d7f09764 | 1301 | |
412288f1 | 1302 | index = streamer_read_uhwi (ib); |
7380e6ef | 1303 | encoder = file_data->symtab_node_encoder; |
d52f5295 ML |
1304 | node = dyn_cast<cgraph_node *> (lto_symtab_encoder_deref (encoder, |
1305 | index)); | |
d7f09764 | 1306 | |
36330f82 | 1307 | fs = funct_state_summaries->get_create (node); |
d7f09764 DN |
1308 | /* Note that the flags must be read in the opposite |
1309 | order in which they were written (the bitflags were | |
1310 | pushed into FLAGS). */ | |
412288f1 | 1311 | bp = streamer_read_bitpack (ib); |
d7f09764 | 1312 | fs->pure_const_state |
2465dcc2 | 1313 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
d7f09764 | 1314 | fs->state_previously_known |
2465dcc2 RG |
1315 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
1316 | fs->looping_previously_known = bp_unpack_value (&bp, 1); | |
1317 | fs->looping = bp_unpack_value (&bp, 1); | |
1318 | fs->can_throw = bp_unpack_value (&bp, 1); | |
8413ca87 | 1319 | fs->can_free = bp_unpack_value (&bp, 1); |
0fab169b PK |
1320 | fs->malloc_state |
1321 | = (enum malloc_state_e) bp_unpack_value (&bp, 2); | |
1322 | ||
d56026c2 JH |
1323 | if (dump_file) |
1324 | { | |
67348ccc | 1325 | int flags = flags_from_decl_or_type (node->decl); |
464d0118 | 1326 | fprintf (dump_file, "Read info for %s ", node->dump_name ()); |
d56026c2 JH |
1327 | if (flags & ECF_CONST) |
1328 | fprintf (dump_file, " const"); | |
1329 | if (flags & ECF_PURE) | |
1330 | fprintf (dump_file, " pure"); | |
1331 | if (flags & ECF_NOTHROW) | |
1332 | fprintf (dump_file, " nothrow"); | |
1333 | fprintf (dump_file, "\n pure const state: %s\n", | |
1334 | pure_const_names[fs->pure_const_state]); | |
1335 | fprintf (dump_file, " previously known state: %s\n", | |
cc950f98 | 1336 | pure_const_names[fs->state_previously_known]); |
d56026c2 JH |
1337 | if (fs->looping) |
1338 | fprintf (dump_file," function is locally looping\n"); | |
1339 | if (fs->looping_previously_known) | |
1340 | fprintf (dump_file," function is previously known looping\n"); | |
1341 | if (fs->can_throw) | |
1342 | fprintf (dump_file," function is locally throwing\n"); | |
8413ca87 JJ |
1343 | if (fs->can_free) |
1344 | fprintf (dump_file," function can locally free\n"); | |
0fab169b PK |
1345 | fprintf (dump_file, "\n malloc state: %s\n", |
1346 | malloc_state_names[fs->malloc_state]); | |
d56026c2 | 1347 | } |
d7f09764 DN |
1348 | } |
1349 | ||
b8698a0f L |
1350 | lto_destroy_simple_input_block (file_data, |
1351 | LTO_section_ipa_pure_const, | |
d7f09764 DN |
1352 | ib, data, len); |
1353 | } | |
1354 | } | |
1355 | } | |
1356 | ||
9644e52a JH |
1357 | /* We only propagate across edges that can throw externally and their callee |
1358 | is not interposable. */ | |
d7f09764 | 1359 | |
2505c5ed | 1360 | static bool |
9644e52a | 1361 | ignore_edge_for_nothrow (struct cgraph_edge *e) |
2505c5ed | 1362 | { |
9644e52a JH |
1363 | if (!e->can_throw_external || TREE_NOTHROW (e->callee->decl)) |
1364 | return true; | |
1365 | ||
1366 | enum availability avail; | |
97e59627 ML |
1367 | cgraph_node *ultimate_target |
1368 | = e->callee->function_or_virtual_thunk_symbol (&avail, e->caller); | |
1369 | if (avail <= AVAIL_INTERPOSABLE || TREE_NOTHROW (ultimate_target->decl)) | |
a2b056a3 | 1370 | return true; |
97e59627 ML |
1371 | return ((opt_for_fn (e->callee->decl, flag_non_call_exceptions) |
1372 | && !e->callee->binds_to_current_def_p (e->caller)) | |
1373 | || !opt_for_fn (e->caller->decl, flag_ipa_pure_const) | |
1374 | || !opt_for_fn (ultimate_target->decl, flag_ipa_pure_const)); | |
2505c5ed JH |
1375 | } |
1376 | ||
fede8efa | 1377 | /* Return true if NODE is self recursive function. |
fc11f321 JH |
1378 | Indirectly recursive functions appears as non-trivial strongly |
1379 | connected components, so we need to care about self recursion | |
1380 | only. */ | |
03ec7d01 JH |
1381 | |
1382 | static bool | |
1383 | self_recursive_p (struct cgraph_node *node) | |
1384 | { | |
1385 | struct cgraph_edge *e; | |
1386 | for (e = node->callees; e; e = e->next_callee) | |
d52f5295 | 1387 | if (e->callee->function_symbol () == node) |
03ec7d01 JH |
1388 | return true; |
1389 | return false; | |
1390 | } | |
1391 | ||
17e0fc92 JH |
1392 | /* Return true if N is cdtor that is not const or pure. In this case we may |
1393 | need to remove unreachable function if it is marked const/pure. */ | |
1394 | ||
1395 | static bool | |
1396 | cdtor_p (cgraph_node *n, void *) | |
1397 | { | |
1398 | if (DECL_STATIC_CONSTRUCTOR (n->decl) || DECL_STATIC_DESTRUCTOR (n->decl)) | |
cd6d518b JJ |
1399 | return ((!TREE_READONLY (n->decl) && !DECL_PURE_P (n->decl)) |
1400 | || DECL_LOOPING_CONST_OR_PURE_P (n->decl)); | |
17e0fc92 JH |
1401 | return false; |
1402 | } | |
1403 | ||
97e59627 ML |
1404 | /* Skip edges from and to nodes without ipa_pure_const enabled. |
1405 | Ignore not available symbols. */ | |
d8e3e8a5 JH |
1406 | |
1407 | static bool | |
1408 | ignore_edge_for_pure_const (struct cgraph_edge *e) | |
1409 | { | |
1410 | enum availability avail; | |
97e59627 ML |
1411 | cgraph_node *ultimate_target |
1412 | = e->callee->function_or_virtual_thunk_symbol (&avail, e->caller); | |
d8e3e8a5 | 1413 | |
97e59627 ML |
1414 | return (avail <= AVAIL_INTERPOSABLE |
1415 | || !opt_for_fn (e->caller->decl, flag_ipa_pure_const) | |
1416 | || !opt_for_fn (ultimate_target->decl, | |
1417 | flag_ipa_pure_const)); | |
1418 | } | |
d8e3e8a5 | 1419 | |
15e80fc3 JH |
1420 | /* Produce transitive closure over the callgraph and compute pure/const |
1421 | attributes. */ | |
f10ea640 | 1422 | |
17e0fc92 | 1423 | static bool |
15e80fc3 | 1424 | propagate_pure_const (void) |
812dbce5 JH |
1425 | { |
1426 | struct cgraph_node *node; | |
1427 | struct cgraph_node *w; | |
1428 | struct cgraph_node **order = | |
3dafb85c | 1429 | XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); |
812dbce5 JH |
1430 | int order_pos; |
1431 | int i; | |
1432 | struct ipa_dfs_info * w_info; | |
17e0fc92 | 1433 | bool remove_p = false; |
6b715bf6 | 1434 | bool has_cdtor; |
812dbce5 | 1435 | |
45272fd2 | 1436 | order_pos = ipa_reduced_postorder (order, true, |
d8e3e8a5 | 1437 | ignore_edge_for_pure_const); |
ea900239 DB |
1438 | if (dump_file) |
1439 | { | |
d52f5295 | 1440 | cgraph_node::dump_cgraph (dump_file); |
40a7fe1e | 1441 | ipa_print_order (dump_file, "reduced", order, order_pos); |
ea900239 DB |
1442 | } |
1443 | ||
073a8998 | 1444 | /* Propagate the local information through the call graph to produce |
ea900239 DB |
1445 | the global information. All the nodes within a cycle will have |
1446 | the same info so we collapse cycles first. Then we can do the | |
1447 | propagation in one pass from the leaves to the roots. */ | |
1448 | for (i = 0; i < order_pos; i++ ) | |
1449 | { | |
1450 | enum pure_const_state_e pure_const_state = IPA_CONST; | |
becfd6e5 | 1451 | bool looping = false; |
17541d72 | 1452 | int count = 0; |
ea900239 DB |
1453 | node = order[i]; |
1454 | ||
67348ccc | 1455 | if (node->alias) |
71fb4f92 JH |
1456 | continue; |
1457 | ||
d56026c2 JH |
1458 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1459 | fprintf (dump_file, "Starting cycle\n"); | |
1460 | ||
ea900239 DB |
1461 | /* Find the worst state for any node in the cycle. */ |
1462 | w = node; | |
f10ea640 | 1463 | while (w && pure_const_state != IPA_NEITHER) |
ea900239 | 1464 | { |
33977f81 | 1465 | struct cgraph_edge *e; |
f10ea640 JH |
1466 | struct cgraph_edge *ie; |
1467 | int i; | |
d122681a | 1468 | struct ipa_ref *ref = NULL; |
f10ea640 | 1469 | |
36330f82 | 1470 | funct_state w_l = funct_state_summaries->get_create (w); |
d56026c2 | 1471 | if (dump_file && (dump_flags & TDF_DETAILS)) |
464d0118 ML |
1472 | fprintf (dump_file, " Visiting %s state:%s looping %i\n", |
1473 | w->dump_name (), | |
d56026c2 JH |
1474 | pure_const_names[w_l->pure_const_state], |
1475 | w_l->looping); | |
ea900239 | 1476 | |
cc950f98 JH |
1477 | /* First merge in function body properties. |
1478 | We are safe to pass NULL as FROM and TO because we will take care | |
1479 | of possible interposition when walking callees. */ | |
f10ea640 | 1480 | worse_state (&pure_const_state, &looping, |
cc950f98 JH |
1481 | w_l->pure_const_state, w_l->looping, |
1482 | NULL, NULL); | |
f10ea640 JH |
1483 | if (pure_const_state == IPA_NEITHER) |
1484 | break; | |
1485 | ||
33977f81 JH |
1486 | count++; |
1487 | ||
f10ea640 JH |
1488 | /* We consider recursive cycles as possibly infinite. |
1489 | This might be relaxed since infinite recursion leads to stack | |
1490 | overflow. */ | |
33977f81 JH |
1491 | if (count > 1) |
1492 | looping = true; | |
b8698a0f | 1493 | |
f10ea640 | 1494 | /* Now walk the edges and merge in callee properties. */ |
d8e3e8a5 JH |
1495 | for (e = w->callees; e && pure_const_state != IPA_NEITHER; |
1496 | e = e->next_callee) | |
ea900239 | 1497 | { |
fede8efa | 1498 | enum availability avail; |
6cbde2e3 | 1499 | struct cgraph_node *y = e->callee-> |
cc950f98 JH |
1500 | function_or_virtual_thunk_symbol (&avail, |
1501 | e->caller); | |
d56026c2 JH |
1502 | enum pure_const_state_e edge_state = IPA_CONST; |
1503 | bool edge_looping = false; | |
17541d72 | 1504 | |
d56026c2 JH |
1505 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1506 | { | |
464d0118 ML |
1507 | fprintf (dump_file, " Call to %s", |
1508 | e->callee->dump_name ()); | |
d56026c2 | 1509 | } |
d52f5295 | 1510 | if (avail > AVAIL_INTERPOSABLE) |
ea900239 | 1511 | { |
b3f2b048 ML |
1512 | funct_state y_l = funct_state_summaries->get_create (y); |
1513 | ||
d56026c2 JH |
1514 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1515 | { | |
1516 | fprintf (dump_file, | |
1517 | " state:%s looping:%i\n", | |
1518 | pure_const_names[y_l->pure_const_state], | |
1519 | y_l->looping); | |
1520 | } | |
da8c7675 | 1521 | if (y_l->pure_const_state > IPA_PURE |
3dafb85c | 1522 | && e->cannot_lead_to_return_p ()) |
d56026c2 JH |
1523 | { |
1524 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
f10ea640 JH |
1525 | fprintf (dump_file, |
1526 | " Ignoring side effects" | |
1527 | " -> pure, looping\n"); | |
d56026c2 JH |
1528 | edge_state = IPA_PURE; |
1529 | edge_looping = true; | |
1530 | } | |
1531 | else | |
1532 | { | |
1533 | edge_state = y_l->pure_const_state; | |
1534 | edge_looping = y_l->looping; | |
1535 | } | |
ea900239 | 1536 | } |
9e97ff61 | 1537 | else if (special_builtin_state (&edge_state, &edge_looping, |
813b70a1 | 1538 | y->decl)) |
0a42aa4e | 1539 | ; |
c59f5d1b | 1540 | else |
f10ea640 | 1541 | state_from_flags (&edge_state, &edge_looping, |
67348ccc | 1542 | flags_from_decl_or_type (y->decl), |
3dafb85c | 1543 | e->cannot_lead_to_return_p ()); |
f10ea640 JH |
1544 | |
1545 | /* Merge the results with what we already know. */ | |
1546 | better_state (&edge_state, &edge_looping, | |
1547 | w_l->state_previously_known, | |
1548 | w_l->looping_previously_known); | |
1549 | worse_state (&pure_const_state, &looping, | |
cc950f98 | 1550 | edge_state, edge_looping, e->caller, e->callee); |
f10ea640 JH |
1551 | if (pure_const_state == IPA_NEITHER) |
1552 | break; | |
1553 | } | |
c59f5d1b | 1554 | |
f10ea640 | 1555 | /* Now process the indirect call. */ |
d8e3e8a5 JH |
1556 | for (ie = w->indirect_calls; |
1557 | ie && pure_const_state != IPA_NEITHER; ie = ie->next_callee) | |
f10ea640 JH |
1558 | { |
1559 | enum pure_const_state_e edge_state = IPA_CONST; | |
1560 | bool edge_looping = false; | |
da8c7675 | 1561 | |
f10ea640 JH |
1562 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1563 | fprintf (dump_file, " Indirect call"); | |
1564 | state_from_flags (&edge_state, &edge_looping, | |
1565 | ie->indirect_info->ecf_flags, | |
3dafb85c | 1566 | ie->cannot_lead_to_return_p ()); |
f10ea640 JH |
1567 | /* Merge the results with what we already know. */ |
1568 | better_state (&edge_state, &edge_looping, | |
1569 | w_l->state_previously_known, | |
1570 | w_l->looping_previously_known); | |
1571 | worse_state (&pure_const_state, &looping, | |
cc950f98 | 1572 | edge_state, edge_looping, NULL, NULL); |
d56026c2 JH |
1573 | if (pure_const_state == IPA_NEITHER) |
1574 | break; | |
ea900239 | 1575 | } |
f10ea640 JH |
1576 | |
1577 | /* And finally all loads and stores. */ | |
d8e3e8a5 JH |
1578 | for (i = 0; w->iterate_reference (i, ref) |
1579 | && pure_const_state != IPA_NEITHER; i++) | |
f10ea640 JH |
1580 | { |
1581 | enum pure_const_state_e ref_state = IPA_CONST; | |
1582 | bool ref_looping = false; | |
1583 | switch (ref->use) | |
1584 | { | |
1585 | case IPA_REF_LOAD: | |
1586 | /* readonly reads are safe. */ | |
d122681a | 1587 | if (TREE_READONLY (ref->referred->decl)) |
f10ea640 JH |
1588 | break; |
1589 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1590 | fprintf (dump_file, " nonreadonly global var read\n"); | |
1591 | ref_state = IPA_PURE; | |
1592 | break; | |
1593 | case IPA_REF_STORE: | |
d122681a | 1594 | if (ref->cannot_lead_to_return ()) |
f10ea640 JH |
1595 | break; |
1596 | ref_state = IPA_NEITHER; | |
1597 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1598 | fprintf (dump_file, " global var write\n"); | |
1599 | break; | |
1600 | case IPA_REF_ADDR: | |
1601 | break; | |
7d2268ea MJ |
1602 | default: |
1603 | gcc_unreachable (); | |
f10ea640 JH |
1604 | } |
1605 | better_state (&ref_state, &ref_looping, | |
1606 | w_l->state_previously_known, | |
1607 | w_l->looping_previously_known); | |
1608 | worse_state (&pure_const_state, &looping, | |
cc950f98 | 1609 | ref_state, ref_looping, NULL, NULL); |
f10ea640 JH |
1610 | if (pure_const_state == IPA_NEITHER) |
1611 | break; | |
1612 | } | |
67348ccc | 1613 | w_info = (struct ipa_dfs_info *) w->aux; |
ea900239 DB |
1614 | w = w_info->next_cycle; |
1615 | } | |
d56026c2 JH |
1616 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1617 | fprintf (dump_file, "Result %s looping %i\n", | |
1618 | pure_const_names [pure_const_state], | |
1619 | looping); | |
ea900239 | 1620 | |
8413ca87 JJ |
1621 | /* Find the worst state of can_free for any node in the cycle. */ |
1622 | bool can_free = false; | |
1623 | w = node; | |
1624 | while (w && !can_free) | |
1625 | { | |
1626 | struct cgraph_edge *e; | |
a756f161 | 1627 | funct_state w_l = funct_state_summaries->get (w); |
8413ca87 JJ |
1628 | |
1629 | if (w_l->can_free | |
1630 | || w->get_availability () == AVAIL_INTERPOSABLE | |
1631 | || w->indirect_calls) | |
1632 | can_free = true; | |
1633 | ||
1634 | for (e = w->callees; e && !can_free; e = e->next_callee) | |
1635 | { | |
1636 | enum availability avail; | |
6cbde2e3 | 1637 | struct cgraph_node *y = e->callee-> |
cc950f98 JH |
1638 | function_or_virtual_thunk_symbol (&avail, |
1639 | e->caller); | |
8413ca87 JJ |
1640 | |
1641 | if (avail > AVAIL_INTERPOSABLE) | |
a756f161 | 1642 | can_free = funct_state_summaries->get (y)->can_free; |
8413ca87 JJ |
1643 | else |
1644 | can_free = true; | |
1645 | } | |
1646 | w_info = (struct ipa_dfs_info *) w->aux; | |
1647 | w = w_info->next_cycle; | |
1648 | } | |
1649 | ||
ea900239 DB |
1650 | /* Copy back the region's pure_const_state which is shared by |
1651 | all nodes in the region. */ | |
1652 | w = node; | |
1653 | while (w) | |
1654 | { | |
a756f161 | 1655 | funct_state w_l = funct_state_summaries->get (w); |
33977f81 JH |
1656 | enum pure_const_state_e this_state = pure_const_state; |
1657 | bool this_looping = looping; | |
ea900239 | 1658 | |
8413ca87 JJ |
1659 | w_l->can_free = can_free; |
1660 | w->nonfreeing_fn = !can_free; | |
1661 | if (!can_free && dump_file) | |
1662 | fprintf (dump_file, "Function found not to call free: %s\n", | |
3629ff8a | 1663 | w->dump_name ()); |
8413ca87 | 1664 | |
f87c9042 JH |
1665 | if (w_l->state_previously_known != IPA_NEITHER |
1666 | && this_state > w_l->state_previously_known) | |
da8c7675 JH |
1667 | { |
1668 | this_state = w_l->state_previously_known; | |
d8e3e8a5 JH |
1669 | if (this_state == IPA_NEITHER) |
1670 | this_looping = w_l->looping_previously_known; | |
da8c7675 | 1671 | } |
03ec7d01 JH |
1672 | if (!this_looping && self_recursive_p (w)) |
1673 | this_looping = true; | |
f87c9042 JH |
1674 | if (!w_l->looping_previously_known) |
1675 | this_looping = false; | |
812dbce5 | 1676 | |
33977f81 JH |
1677 | /* All nodes within a cycle share the same info. */ |
1678 | w_l->pure_const_state = this_state; | |
1679 | w_l->looping = this_looping; | |
1680 | ||
d7636f56 JH |
1681 | /* Inline clones share declaration with their offline copies; |
1682 | do not modify their declarations since the offline copy may | |
1683 | be different. */ | |
a62bfab5 | 1684 | if (!w->inlined_to) |
d7636f56 JH |
1685 | switch (this_state) |
1686 | { | |
1687 | case IPA_CONST: | |
1688 | if (!TREE_READONLY (w->decl)) | |
1689 | { | |
1690 | warn_function_const (w->decl, !this_looping); | |
1691 | if (dump_file) | |
1692 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
1693 | this_looping ? "looping " : "", | |
3629ff8a | 1694 | w->dump_name ()); |
d7636f56 | 1695 | } |
6b715bf6 JH |
1696 | /* Turning constructor or destructor to non-looping const/pure |
1697 | enables us to possibly remove the function completely. */ | |
1698 | if (this_looping) | |
1699 | has_cdtor = false; | |
1700 | else | |
1701 | has_cdtor = w->call_for_symbol_and_aliases (cdtor_p, | |
1702 | NULL, true); | |
1703 | if (w->set_const_flag (true, this_looping)) | |
1704 | { | |
1705 | if (dump_file) | |
1706 | fprintf (dump_file, | |
1707 | "Declaration updated to be %sconst: %s\n", | |
1708 | this_looping ? "looping " : "", | |
3629ff8a | 1709 | w->dump_name ()); |
6b715bf6 JH |
1710 | remove_p |= has_cdtor; |
1711 | } | |
d7636f56 | 1712 | break; |
b8698a0f | 1713 | |
d7636f56 JH |
1714 | case IPA_PURE: |
1715 | if (!DECL_PURE_P (w->decl)) | |
1716 | { | |
1717 | warn_function_pure (w->decl, !this_looping); | |
1718 | if (dump_file) | |
1719 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
1720 | this_looping ? "looping " : "", | |
3629ff8a | 1721 | w->dump_name ()); |
d7636f56 | 1722 | } |
6b715bf6 JH |
1723 | if (this_looping) |
1724 | has_cdtor = false; | |
1725 | else | |
1726 | has_cdtor = w->call_for_symbol_and_aliases (cdtor_p, | |
1727 | NULL, true); | |
1728 | if (w->set_pure_flag (true, this_looping)) | |
1729 | { | |
1730 | if (dump_file) | |
1731 | fprintf (dump_file, | |
1732 | "Declaration updated to be %spure: %s\n", | |
1733 | this_looping ? "looping " : "", | |
3629ff8a | 1734 | w->dump_name ()); |
6b715bf6 JH |
1735 | remove_p |= has_cdtor; |
1736 | } | |
d7636f56 | 1737 | break; |
b8698a0f | 1738 | |
d7636f56 JH |
1739 | default: |
1740 | break; | |
1741 | } | |
67348ccc | 1742 | w_info = (struct ipa_dfs_info *) w->aux; |
2505c5ed JH |
1743 | w = w_info->next_cycle; |
1744 | } | |
1745 | } | |
1746 | ||
af8bca3c | 1747 | ipa_free_postorder_info (); |
15e80fc3 | 1748 | free (order); |
17e0fc92 | 1749 | return remove_p; |
15e80fc3 JH |
1750 | } |
1751 | ||
1752 | /* Produce transitive closure over the callgraph and compute nothrow | |
1753 | attributes. */ | |
1754 | ||
1755 | static void | |
1756 | propagate_nothrow (void) | |
1757 | { | |
1758 | struct cgraph_node *node; | |
1759 | struct cgraph_node *w; | |
1760 | struct cgraph_node **order = | |
3dafb85c | 1761 | XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); |
15e80fc3 JH |
1762 | int order_pos; |
1763 | int i; | |
1764 | struct ipa_dfs_info * w_info; | |
1765 | ||
45272fd2 | 1766 | order_pos = ipa_reduced_postorder (order, true, |
9644e52a | 1767 | ignore_edge_for_nothrow); |
2505c5ed JH |
1768 | if (dump_file) |
1769 | { | |
d52f5295 | 1770 | cgraph_node::dump_cgraph (dump_file); |
af8bca3c | 1771 | ipa_print_order (dump_file, "reduced for nothrow", order, order_pos); |
2505c5ed | 1772 | } |
15e80fc3 | 1773 | |
073a8998 | 1774 | /* Propagate the local information through the call graph to produce |
2505c5ed JH |
1775 | the global information. All the nodes within a cycle will have |
1776 | the same info so we collapse cycles first. Then we can do the | |
1777 | propagation in one pass from the leaves to the roots. */ | |
1778 | for (i = 0; i < order_pos; i++ ) | |
1779 | { | |
1780 | bool can_throw = false; | |
1781 | node = order[i]; | |
1782 | ||
67348ccc | 1783 | if (node->alias) |
71fb4f92 JH |
1784 | continue; |
1785 | ||
2505c5ed JH |
1786 | /* Find the worst state for any node in the cycle. */ |
1787 | w = node; | |
abb50207 | 1788 | while (w && !can_throw) |
2505c5ed | 1789 | { |
f10ea640 | 1790 | struct cgraph_edge *e, *ie; |
2505c5ed | 1791 | |
9644e52a | 1792 | if (!TREE_NOTHROW (w->decl)) |
2505c5ed | 1793 | { |
36330f82 | 1794 | funct_state w_l = funct_state_summaries->get_create (w); |
2505c5ed | 1795 | |
9644e52a JH |
1796 | if (w_l->can_throw |
1797 | || w->get_availability () == AVAIL_INTERPOSABLE) | |
1798 | can_throw = true; | |
1799 | ||
1800 | for (e = w->callees; e && !can_throw; e = e->next_callee) | |
2505c5ed | 1801 | { |
9644e52a JH |
1802 | enum availability avail; |
1803 | ||
1804 | if (!e->can_throw_external || TREE_NOTHROW (e->callee->decl)) | |
1805 | continue; | |
1806 | ||
1807 | struct cgraph_node *y = e->callee-> | |
a2b056a3 JH |
1808 | function_or_virtual_thunk_symbol (&avail, |
1809 | e->caller); | |
2505c5ed | 1810 | |
155ed511 SL |
1811 | /* We can use info about the callee only if we know it |
1812 | cannot be interposed. | |
a2b056a3 JH |
1813 | When callee is compiled with non-call exceptions we also |
1814 | must check that the declaration is bound to current | |
1815 | body as other semantically equivalent body may still | |
1816 | throw. */ | |
9644e52a JH |
1817 | if (avail <= AVAIL_INTERPOSABLE |
1818 | || (!TREE_NOTHROW (y->decl) | |
36330f82 | 1819 | && (funct_state_summaries->get_create (y)->can_throw |
a2b056a3 JH |
1820 | || (opt_for_fn (y->decl, flag_non_call_exceptions) |
1821 | && !e->callee->binds_to_current_def_p (w))))) | |
2505c5ed JH |
1822 | can_throw = true; |
1823 | } | |
9644e52a JH |
1824 | for (ie = w->indirect_calls; ie && !can_throw; |
1825 | ie = ie->next_callee) | |
1826 | if (ie->can_throw_external | |
1827 | && !(ie->indirect_info->ecf_flags & ECF_NOTHROW)) | |
1828 | can_throw = true; | |
2505c5ed | 1829 | } |
67348ccc | 1830 | w_info = (struct ipa_dfs_info *) w->aux; |
2505c5ed JH |
1831 | w = w_info->next_cycle; |
1832 | } | |
1833 | ||
1834 | /* Copy back the region's pure_const_state which is shared by | |
1835 | all nodes in the region. */ | |
1836 | w = node; | |
1837 | while (w) | |
1838 | { | |
61c74e84 | 1839 | funct_state w_l = funct_state_summaries->get_create (w); |
67348ccc | 1840 | if (!can_throw && !TREE_NOTHROW (w->decl)) |
33977f81 | 1841 | { |
d7636f56 JH |
1842 | /* Inline clones share declaration with their offline copies; |
1843 | do not modify their declarations since the offline copy may | |
1844 | be different. */ | |
a62bfab5 | 1845 | if (!w->inlined_to) |
d7636f56 | 1846 | { |
d52f5295 | 1847 | w->set_nothrow_flag (true); |
d7636f56 JH |
1848 | if (dump_file) |
1849 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
3629ff8a | 1850 | w->dump_name ()); |
d7636f56 | 1851 | } |
ea900239 | 1852 | } |
67348ccc | 1853 | else if (can_throw && !TREE_NOTHROW (w->decl)) |
b6fa5b01 | 1854 | w_l->can_throw = true; |
67348ccc | 1855 | w_info = (struct ipa_dfs_info *) w->aux; |
ea900239 DB |
1856 | w = w_info->next_cycle; |
1857 | } | |
1858 | } | |
1859 | ||
af8bca3c | 1860 | ipa_free_postorder_info (); |
ea900239 | 1861 | free (order); |
15e80fc3 JH |
1862 | } |
1863 | ||
0fab169b PK |
1864 | /* Debugging function to dump state of malloc lattice. */ |
1865 | ||
1866 | DEBUG_FUNCTION | |
1867 | static void | |
1868 | dump_malloc_lattice (FILE *dump_file, const char *s) | |
1869 | { | |
1870 | if (!dump_file) | |
1871 | return; | |
1872 | ||
1873 | fprintf (dump_file, "\n\nMALLOC LATTICE %s:\n", s); | |
1874 | cgraph_node *node; | |
1875 | FOR_EACH_FUNCTION (node) | |
1876 | { | |
67b3b8fe ML |
1877 | funct_state fs = funct_state_summaries->get (node); |
1878 | if (fs) | |
3629ff8a | 1879 | fprintf (dump_file, "%s: %s\n", node->dump_name (), |
67b3b8fe | 1880 | malloc_state_names[fs->malloc_state]); |
0fab169b PK |
1881 | } |
1882 | } | |
1883 | ||
1884 | /* Propagate malloc attribute across the callgraph. */ | |
1885 | ||
1886 | static void | |
1887 | propagate_malloc (void) | |
1888 | { | |
1889 | cgraph_node *node; | |
1890 | FOR_EACH_FUNCTION (node) | |
1891 | { | |
1892 | if (DECL_IS_MALLOC (node->decl)) | |
36330f82 | 1893 | if (!funct_state_summaries->exists (node)) |
0fab169b | 1894 | { |
36330f82 ML |
1895 | funct_state fs = funct_state_summaries->get_create (node); |
1896 | fs->malloc_state = STATE_MALLOC; | |
0fab169b PK |
1897 | } |
1898 | } | |
1899 | ||
1900 | dump_malloc_lattice (dump_file, "Initial"); | |
1901 | struct cgraph_node **order | |
1902 | = XNEWVEC (struct cgraph_node *, symtab->cgraph_count); | |
1903 | int order_pos = ipa_reverse_postorder (order); | |
1904 | bool changed = true; | |
1905 | ||
1906 | while (changed) | |
1907 | { | |
1908 | changed = false; | |
1909 | /* Walk in postorder. */ | |
1910 | for (int i = order_pos - 1; i >= 0; --i) | |
1911 | { | |
1912 | cgraph_node *node = order[i]; | |
1913 | if (node->alias | |
1914 | || !node->definition | |
36330f82 | 1915 | || !funct_state_summaries->exists (node)) |
0fab169b PK |
1916 | continue; |
1917 | ||
67b3b8fe | 1918 | funct_state l = funct_state_summaries->get (node); |
0fab169b PK |
1919 | |
1920 | /* FIXME: add support for indirect-calls. */ | |
1921 | if (node->indirect_calls) | |
1922 | { | |
1923 | l->malloc_state = STATE_MALLOC_BOTTOM; | |
1924 | continue; | |
1925 | } | |
1926 | ||
1927 | if (node->get_availability () <= AVAIL_INTERPOSABLE) | |
1928 | { | |
1929 | l->malloc_state = STATE_MALLOC_BOTTOM; | |
1930 | continue; | |
1931 | } | |
1932 | ||
1933 | if (l->malloc_state == STATE_MALLOC_BOTTOM) | |
1934 | continue; | |
1935 | ||
1936 | vec<cgraph_node *> callees = vNULL; | |
1937 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) | |
1938 | { | |
99353fcf | 1939 | ipa_call_summary *es = ipa_call_summaries->get_create (cs); |
0fab169b PK |
1940 | if (es && es->is_return_callee_uncaptured) |
1941 | callees.safe_push (cs->callee); | |
1942 | } | |
1943 | ||
1944 | malloc_state_e new_state = l->malloc_state; | |
1945 | for (unsigned j = 0; j < callees.length (); j++) | |
1946 | { | |
1947 | cgraph_node *callee = callees[j]; | |
36330f82 | 1948 | if (!funct_state_summaries->exists (node)) |
0fab169b PK |
1949 | { |
1950 | new_state = STATE_MALLOC_BOTTOM; | |
1951 | break; | |
1952 | } | |
36330f82 ML |
1953 | malloc_state_e callee_state |
1954 | = funct_state_summaries->get_create (callee)->malloc_state; | |
0fab169b PK |
1955 | if (new_state < callee_state) |
1956 | new_state = callee_state; | |
1957 | } | |
1958 | if (new_state != l->malloc_state) | |
1959 | { | |
1960 | changed = true; | |
1961 | l->malloc_state = new_state; | |
1962 | } | |
1963 | } | |
1964 | } | |
1965 | ||
1966 | FOR_EACH_DEFINED_FUNCTION (node) | |
36330f82 | 1967 | if (funct_state_summaries->exists (node)) |
0fab169b | 1968 | { |
67b3b8fe | 1969 | funct_state l = funct_state_summaries->get (node); |
0fab169b PK |
1970 | if (!node->alias |
1971 | && l->malloc_state == STATE_MALLOC | |
a62bfab5 | 1972 | && !node->inlined_to) |
0fab169b PK |
1973 | { |
1974 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1975 | fprintf (dump_file, "Function %s found to be malloc\n", | |
3629ff8a | 1976 | node->dump_name ()); |
0fab169b PK |
1977 | |
1978 | bool malloc_decl_p = DECL_IS_MALLOC (node->decl); | |
1979 | node->set_malloc_flag (true); | |
1980 | if (!malloc_decl_p && warn_suggest_attribute_malloc) | |
1981 | warn_function_malloc (node->decl); | |
1982 | } | |
1983 | } | |
1984 | ||
1985 | dump_malloc_lattice (dump_file, "after propagation"); | |
1986 | ipa_free_postorder_info (); | |
1987 | free (order); | |
1988 | } | |
15e80fc3 JH |
1989 | |
1990 | /* Produce the global information by preforming a transitive closure | |
1991 | on the local information that was produced by generate_summary. */ | |
1992 | ||
3edf64aa DM |
1993 | unsigned int |
1994 | pass_ipa_pure_const:: | |
1995 | execute (function *) | |
15e80fc3 | 1996 | { |
17e0fc92 | 1997 | bool remove_p; |
15e80fc3 | 1998 | |
15e80fc3 JH |
1999 | /* Nothrow makes more function to not lead to return and improve |
2000 | later analysis. */ | |
2001 | propagate_nothrow (); | |
0fab169b | 2002 | propagate_malloc (); |
17e0fc92 | 2003 | remove_p = propagate_pure_const (); |
15e80fc3 | 2004 | |
36330f82 | 2005 | delete funct_state_summaries; |
17e0fc92 | 2006 | return remove_p ? TODO_remove_functions : 0; |
ea900239 DB |
2007 | } |
2008 | ||
2009 | static bool | |
2010 | gate_pure_const (void) | |
2011 | { | |
2bf86c84 | 2012 | return flag_ipa_pure_const || in_lto_p; |
ea900239 DB |
2013 | } |
2014 | ||
3edf64aa DM |
2015 | pass_ipa_pure_const::pass_ipa_pure_const(gcc::context *ctxt) |
2016 | : ipa_opt_pass_d(pass_data_ipa_pure_const, ctxt, | |
2017 | pure_const_generate_summary, /* generate_summary */ | |
2018 | pure_const_write_summary, /* write_summary */ | |
2019 | pure_const_read_summary, /* read_summary */ | |
2020 | NULL, /* write_optimization_summary */ | |
2021 | NULL, /* read_optimization_summary */ | |
2022 | NULL, /* stmt_fixup */ | |
2023 | 0, /* function_transform_todo_flags_start */ | |
2024 | NULL, /* function_transform */ | |
2025 | NULL), /* variable_transform */ | |
36330f82 | 2026 | init_p (false) {} |
27a4cd48 DM |
2027 | |
2028 | ipa_opt_pass_d * | |
2029 | make_pass_ipa_pure_const (gcc::context *ctxt) | |
2030 | { | |
2031 | return new pass_ipa_pure_const (ctxt); | |
2032 | } | |
2033 | ||
5dc16b19 | 2034 | /* Return true if function should be skipped for local pure const analysis. */ |
33977f81 | 2035 | |
5dc16b19 MLI |
2036 | static bool |
2037 | skip_function_for_local_pure_const (struct cgraph_node *node) | |
33977f81 | 2038 | { |
cc950f98 JH |
2039 | /* Because we do not schedule pass_fixup_cfg over whole program after early |
2040 | optimizations we must not promote functions that are called by already | |
2041 | processed functions. */ | |
33977f81 JH |
2042 | |
2043 | if (function_called_by_processed_nodes_p ()) | |
2044 | { | |
2045 | if (dump_file) | |
2046 | fprintf (dump_file, "Function called in recursive cycle; ignoring\n"); | |
5dc16b19 | 2047 | return true; |
33977f81 | 2048 | } |
6b715bf6 JH |
2049 | /* Save some work and do not analyze functions which are interposable and |
2050 | do not have any non-interposable aliases. */ | |
2051 | if (node->get_availability () <= AVAIL_INTERPOSABLE | |
2052 | && !node->has_aliases_p ()) | |
33977f81 JH |
2053 | { |
2054 | if (dump_file) | |
cc950f98 | 2055 | fprintf (dump_file, |
6b715bf6 | 2056 | "Function is interposable; not analyzing.\n"); |
5dc16b19 | 2057 | return true; |
33977f81 | 2058 | } |
5dc16b19 MLI |
2059 | return false; |
2060 | } | |
2061 | ||
2062 | /* Simple local pass for pure const discovery reusing the analysis from | |
2063 | ipa_pure_const. This pass is effective when executed together with | |
2064 | other optimization passes in early optimization pass queue. */ | |
33977f81 | 2065 | |
17795822 TS |
2066 | namespace { |
2067 | ||
2068 | const pass_data pass_data_local_pure_const = | |
be55bfe6 TS |
2069 | { |
2070 | GIMPLE_PASS, /* type */ | |
2071 | "local-pure-const", /* name */ | |
2072 | OPTGROUP_NONE, /* optinfo_flags */ | |
be55bfe6 TS |
2073 | TV_IPA_PURE_CONST, /* tv_id */ |
2074 | 0, /* properties_required */ | |
2075 | 0, /* properties_provided */ | |
2076 | 0, /* properties_destroyed */ | |
2077 | 0, /* todo_flags_start */ | |
2078 | 0, /* todo_flags_finish */ | |
2079 | }; | |
2080 | ||
17795822 | 2081 | class pass_local_pure_const : public gimple_opt_pass |
be55bfe6 TS |
2082 | { |
2083 | public: | |
2084 | pass_local_pure_const (gcc::context *ctxt) | |
2085 | : gimple_opt_pass (pass_data_local_pure_const, ctxt) | |
2086 | {} | |
2087 | ||
2088 | /* opt_pass methods: */ | |
2089 | opt_pass * clone () { return new pass_local_pure_const (m_ctxt); } | |
2090 | virtual bool gate (function *) { return gate_pure_const (); } | |
2091 | virtual unsigned int execute (function *); | |
2092 | ||
2093 | }; // class pass_local_pure_const | |
2094 | ||
2095 | unsigned int | |
2096 | pass_local_pure_const::execute (function *fun) | |
5dc16b19 MLI |
2097 | { |
2098 | bool changed = false; | |
2099 | funct_state l; | |
2100 | bool skip; | |
2101 | struct cgraph_node *node; | |
2102 | ||
d52f5295 | 2103 | node = cgraph_node::get (current_function_decl); |
5dc16b19 | 2104 | skip = skip_function_for_local_pure_const (node); |
12b9f3ac | 2105 | |
5dc16b19 MLI |
2106 | if (!warn_suggest_attribute_const |
2107 | && !warn_suggest_attribute_pure | |
2108 | && skip) | |
2109 | return 0; | |
73add7fe | 2110 | |
269c80f2 JJ |
2111 | l = analyze_function (node, false); |
2112 | ||
2113 | /* Do NORETURN discovery. */ | |
73add7fe | 2114 | if (!skip && !TREE_THIS_VOLATILE (current_function_decl) |
be55bfe6 | 2115 | && EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (fun)->preds) == 0) |
73add7fe | 2116 | { |
be55bfe6 | 2117 | warn_function_noreturn (fun->decl); |
73add7fe | 2118 | if (dump_file) |
be55bfe6 TS |
2119 | fprintf (dump_file, "Function found to be noreturn: %s\n", |
2120 | current_function_name ()); | |
73add7fe JH |
2121 | |
2122 | /* Update declaration and reduce profile to executed once. */ | |
2123 | TREE_THIS_VOLATILE (current_function_decl) = 1; | |
2124 | if (node->frequency > NODE_FREQUENCY_EXECUTED_ONCE) | |
be55bfe6 | 2125 | node->frequency = NODE_FREQUENCY_EXECUTED_ONCE; |
73add7fe JH |
2126 | |
2127 | changed = true; | |
2128 | } | |
c59f5d1b | 2129 | |
33977f81 JH |
2130 | switch (l->pure_const_state) |
2131 | { | |
2132 | case IPA_CONST: | |
2133 | if (!TREE_READONLY (current_function_decl)) | |
2134 | { | |
5dc16b19 | 2135 | warn_function_const (current_function_decl, !l->looping); |
33977f81 JH |
2136 | if (dump_file) |
2137 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
2138 | l->looping ? "looping " : "", | |
df92c640 | 2139 | current_function_name ()); |
33977f81 JH |
2140 | } |
2141 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
2142 | && !l->looping) | |
2143 | { | |
33977f81 JH |
2144 | if (dump_file) |
2145 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
df92c640 | 2146 | current_function_name ()); |
33977f81 | 2147 | } |
6b715bf6 JH |
2148 | if (!skip && node->set_const_flag (true, l->looping)) |
2149 | { | |
2150 | if (dump_file) | |
2151 | fprintf (dump_file, "Declaration updated to be %sconst: %s\n", | |
2152 | l->looping ? "looping " : "", | |
2153 | current_function_name ()); | |
2154 | changed = true; | |
2155 | } | |
33977f81 JH |
2156 | break; |
2157 | ||
2158 | case IPA_PURE: | |
5dc16b19 | 2159 | if (!DECL_PURE_P (current_function_decl)) |
33977f81 | 2160 | { |
5dc16b19 | 2161 | warn_function_pure (current_function_decl, !l->looping); |
33977f81 JH |
2162 | if (dump_file) |
2163 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
2164 | l->looping ? "looping " : "", | |
df92c640 | 2165 | current_function_name ()); |
33977f81 JH |
2166 | } |
2167 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
2168 | && !l->looping) | |
2169 | { | |
33977f81 JH |
2170 | if (dump_file) |
2171 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
df92c640 | 2172 | current_function_name ()); |
33977f81 | 2173 | } |
6b715bf6 JH |
2174 | if (!skip && node->set_pure_flag (true, l->looping)) |
2175 | { | |
2176 | if (dump_file) | |
2177 | fprintf (dump_file, "Declaration updated to be %spure: %s\n", | |
2178 | l->looping ? "looping " : "", | |
2179 | current_function_name ()); | |
2180 | changed = true; | |
2181 | } | |
33977f81 JH |
2182 | break; |
2183 | ||
2184 | default: | |
2185 | break; | |
2186 | } | |
2187 | if (!l->can_throw && !TREE_NOTHROW (current_function_decl)) | |
2188 | { | |
d52f5295 | 2189 | node->set_nothrow_flag (true); |
33977f81 JH |
2190 | changed = true; |
2191 | if (dump_file) | |
2192 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
df92c640 | 2193 | current_function_name ()); |
33977f81 | 2194 | } |
0fab169b PK |
2195 | |
2196 | if (l->malloc_state == STATE_MALLOC | |
2197 | && !DECL_IS_MALLOC (current_function_decl)) | |
2198 | { | |
2199 | node->set_malloc_flag (true); | |
2200 | if (warn_suggest_attribute_malloc) | |
2201 | warn_function_malloc (node->decl); | |
2202 | changed = true; | |
2203 | if (dump_file) | |
2204 | fprintf (dump_file, "Function found to be malloc: %s\n", | |
3629ff8a | 2205 | node->dump_name ()); |
0fab169b PK |
2206 | } |
2207 | ||
04695783 | 2208 | free (l); |
33977f81 JH |
2209 | if (changed) |
2210 | return execute_fixup_cfg (); | |
2211 | else | |
2212 | return 0; | |
2213 | } | |
2214 | ||
17795822 TS |
2215 | } // anon namespace |
2216 | ||
27a4cd48 DM |
2217 | gimple_opt_pass * |
2218 | make_pass_local_pure_const (gcc::context *ctxt) | |
2219 | { | |
2220 | return new pass_local_pure_const (ctxt); | |
2221 | } | |
c1bf2a39 AM |
2222 | |
2223 | /* Emit noreturn warnings. */ | |
2224 | ||
17795822 TS |
2225 | namespace { |
2226 | ||
2227 | const pass_data pass_data_warn_function_noreturn = | |
c1bf2a39 AM |
2228 | { |
2229 | GIMPLE_PASS, /* type */ | |
2230 | "*warn_function_noreturn", /* name */ | |
2231 | OPTGROUP_NONE, /* optinfo_flags */ | |
c1bf2a39 AM |
2232 | TV_NONE, /* tv_id */ |
2233 | PROP_cfg, /* properties_required */ | |
2234 | 0, /* properties_provided */ | |
2235 | 0, /* properties_destroyed */ | |
2236 | 0, /* todo_flags_start */ | |
2237 | 0, /* todo_flags_finish */ | |
2238 | }; | |
2239 | ||
17795822 | 2240 | class pass_warn_function_noreturn : public gimple_opt_pass |
c1bf2a39 AM |
2241 | { |
2242 | public: | |
2243 | pass_warn_function_noreturn (gcc::context *ctxt) | |
2244 | : gimple_opt_pass (pass_data_warn_function_noreturn, ctxt) | |
2245 | {} | |
2246 | ||
2247 | /* opt_pass methods: */ | |
1a3d085c | 2248 | virtual bool gate (function *) { return warn_suggest_attribute_noreturn; } |
be55bfe6 TS |
2249 | virtual unsigned int execute (function *fun) |
2250 | { | |
2251 | if (!TREE_THIS_VOLATILE (current_function_decl) | |
2252 | && EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (fun)->preds) == 0) | |
2253 | warn_function_noreturn (current_function_decl); | |
2254 | return 0; | |
2255 | } | |
c1bf2a39 AM |
2256 | |
2257 | }; // class pass_warn_function_noreturn | |
2258 | ||
17795822 TS |
2259 | } // anon namespace |
2260 | ||
c1bf2a39 AM |
2261 | gimple_opt_pass * |
2262 | make_pass_warn_function_noreturn (gcc::context *ctxt) | |
2263 | { | |
2264 | return new pass_warn_function_noreturn (ctxt); | |
2265 | } | |
38147a2a JH |
2266 | |
2267 | /* Simple local pass for pure const discovery reusing the analysis from | |
2268 | ipa_pure_const. This pass is effective when executed together with | |
2269 | other optimization passes in early optimization pass queue. */ | |
2270 | ||
17795822 TS |
2271 | namespace { |
2272 | ||
2273 | const pass_data pass_data_nothrow = | |
38147a2a JH |
2274 | { |
2275 | GIMPLE_PASS, /* type */ | |
2276 | "nothrow", /* name */ | |
2277 | OPTGROUP_NONE, /* optinfo_flags */ | |
2278 | TV_IPA_PURE_CONST, /* tv_id */ | |
2279 | 0, /* properties_required */ | |
2280 | 0, /* properties_provided */ | |
2281 | 0, /* properties_destroyed */ | |
2282 | 0, /* todo_flags_start */ | |
2283 | 0, /* todo_flags_finish */ | |
2284 | }; | |
2285 | ||
17795822 | 2286 | class pass_nothrow : public gimple_opt_pass |
38147a2a JH |
2287 | { |
2288 | public: | |
2289 | pass_nothrow (gcc::context *ctxt) | |
2290 | : gimple_opt_pass (pass_data_nothrow, ctxt) | |
2291 | {} | |
2292 | ||
2293 | /* opt_pass methods: */ | |
2294 | opt_pass * clone () { return new pass_nothrow (m_ctxt); } | |
2295 | virtual bool gate (function *) { return optimize; } | |
2296 | virtual unsigned int execute (function *); | |
2297 | ||
2298 | }; // class pass_nothrow | |
2299 | ||
2300 | unsigned int | |
2301 | pass_nothrow::execute (function *) | |
2302 | { | |
2303 | struct cgraph_node *node; | |
2304 | basic_block this_block; | |
2305 | ||
2306 | if (TREE_NOTHROW (current_function_decl)) | |
2307 | return 0; | |
2308 | ||
2309 | node = cgraph_node::get (current_function_decl); | |
2310 | ||
67914693 | 2311 | /* We run during lowering, we cannot really use availability yet. */ |
38147a2a JH |
2312 | if (cgraph_node::get (current_function_decl)->get_availability () |
2313 | <= AVAIL_INTERPOSABLE) | |
2314 | { | |
2315 | if (dump_file) | |
2316 | fprintf (dump_file, "Function is interposable;" | |
2317 | " not analyzing.\n"); | |
2318 | return true; | |
2319 | } | |
2320 | ||
2321 | FOR_EACH_BB_FN (this_block, cfun) | |
2322 | { | |
2323 | for (gimple_stmt_iterator gsi = gsi_start_bb (this_block); | |
2324 | !gsi_end_p (gsi); | |
2325 | gsi_next (&gsi)) | |
36bbc05d | 2326 | if (stmt_can_throw_external (cfun, gsi_stmt (gsi))) |
38147a2a JH |
2327 | { |
2328 | if (is_gimple_call (gsi_stmt (gsi))) | |
2329 | { | |
2330 | tree callee_t = gimple_call_fndecl (gsi_stmt (gsi)); | |
2331 | if (callee_t && recursive_call_p (current_function_decl, | |
2332 | callee_t)) | |
2333 | continue; | |
2334 | } | |
2335 | ||
2336 | if (dump_file) | |
2337 | { | |
2338 | fprintf (dump_file, "Statement can throw: "); | |
ef6cb4c7 | 2339 | print_gimple_stmt (dump_file, gsi_stmt (gsi), 0); |
38147a2a JH |
2340 | } |
2341 | return 0; | |
2342 | } | |
2343 | } | |
2344 | ||
2345 | node->set_nothrow_flag (true); | |
d93c452f JJ |
2346 | |
2347 | bool cfg_changed = false; | |
2348 | if (self_recursive_p (node)) | |
2349 | FOR_EACH_BB_FN (this_block, cfun) | |
2350 | if (gimple *g = last_stmt (this_block)) | |
2351 | if (is_gimple_call (g)) | |
2352 | { | |
2353 | tree callee_t = gimple_call_fndecl (g); | |
2354 | if (callee_t | |
2355 | && recursive_call_p (current_function_decl, callee_t) | |
2356 | && maybe_clean_eh_stmt (g) | |
2357 | && gimple_purge_dead_eh_edges (this_block)) | |
2358 | cfg_changed = true; | |
2359 | } | |
2360 | ||
38147a2a JH |
2361 | if (dump_file) |
2362 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
2363 | current_function_name ()); | |
d93c452f | 2364 | return cfg_changed ? TODO_cleanup_cfg : 0; |
38147a2a JH |
2365 | } |
2366 | ||
17795822 TS |
2367 | } // anon namespace |
2368 | ||
38147a2a JH |
2369 | gimple_opt_pass * |
2370 | make_pass_nothrow (gcc::context *ctxt) | |
2371 | { | |
2372 | return new pass_nothrow (ctxt); | |
2373 | } |