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f7d118a9 | 1 | /* Callgraph based analysis of static variables. |
fbd26352 | 2 | Copyright (C) 2004-2019 Free Software Foundation, Inc. |
f7d118a9 | 3 | Contributed by Kenneth Zadeck <zadeck@naturalbridge.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 9 | Software Foundation; either version 3, or (at your option) any later |
f7d118a9 | 10 | version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
f7d118a9 | 20 | |
f0b5f617 | 21 | /* This file marks functions as being either const (TREE_READONLY) or |
22 | pure (DECL_PURE_P). It can also set a variant of these that | |
23 | are allowed to loop indefinitely (DECL_LOOPING_CONST_PURE_P). | |
f7d118a9 | 24 | |
25 | This must be run after inlining decisions have been made since | |
26 | otherwise, the local sets will not contain information that is | |
27 | consistent with post inlined state. The global sets are not prone | |
28 | to this problem since they are by definition transitive. */ | |
29 | ||
30 | /* The code in this module is called by the ipa pass manager. It | |
31 | should be one of the later passes since it's information is used by | |
32 | the rest of the compilation. */ | |
33 | ||
34 | #include "config.h" | |
35 | #include "system.h" | |
36 | #include "coretypes.h" | |
9ef16211 | 37 | #include "backend.h" |
7c29e30e | 38 | #include "target.h" |
f7d118a9 | 39 | #include "tree.h" |
9ef16211 | 40 | #include "gimple.h" |
7c29e30e | 41 | #include "tree-pass.h" |
42 | #include "tree-streamer.h" | |
43 | #include "cgraph.h" | |
44 | #include "diagnostic.h" | |
9ed99284 | 45 | #include "calls.h" |
94ea8568 | 46 | #include "cfganal.h" |
bc61cadb | 47 | #include "tree-eh.h" |
dcf1a1ec | 48 | #include "gimple-iterator.h" |
49 | #include "gimple-walk.h" | |
073c1fd5 | 50 | #include "tree-cfg.h" |
05d9c18a | 51 | #include "tree-ssa-loop-niter.h" |
f7d118a9 | 52 | #include "langhooks.h" |
f7d118a9 | 53 | #include "ipa-utils.h" |
ce084dfc | 54 | #include "gimple-pretty-print.h" |
c9263b6a | 55 | #include "cfgloop.h" |
56 | #include "tree-scalar-evolution.h" | |
2c06958d | 57 | #include "intl.h" |
58 | #include "opts.h" | |
bd5ef087 | 59 | #include "ssa.h" |
60 | #include "alloc-pool.h" | |
61 | #include "symbol-summary.h" | |
62 | #include "ipa-prop.h" | |
63 | #include "ipa-fnsummary.h" | |
f7d118a9 | 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 | ||
bd5ef087 | 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"}; | |
fc94a528 | 85 | |
cb886925 | 86 | /* Holder for the const_state. There is one of these per function |
87 | decl. */ | |
16f72bd0 | 88 | class funct_state_d |
f7d118a9 | 89 | { |
16f72bd0 | 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 | ||
cb886925 | 102 | /* See above. */ |
f7d118a9 | 103 | enum pure_const_state_e pure_const_state; |
b5cebd44 | 104 | /* What user set here; we can be always sure about this. */ |
48e1416a | 105 | enum pure_const_state_e state_previously_known; |
106 | bool looping_previously_known; | |
cb886925 | 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. */ | |
9c2a0c05 | 114 | bool looping; |
cb886925 | 115 | |
b5cebd44 | 116 | bool can_throw; |
04c849b3 | 117 | |
118 | /* If function can call free, munmap or otherwise make previously | |
119 | non-trapping memory accesses trapping. */ | |
120 | bool can_free; | |
bd5ef087 | 121 | |
122 | enum malloc_state_e malloc_state; | |
f7d118a9 | 123 | }; |
124 | ||
125 | typedef struct funct_state_d * funct_state; | |
126 | ||
cb886925 | 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 | |
48e1416a | 129 | local info. */ |
cb886925 | 130 | |
16f72bd0 | 131 | class funct_state_summary_t: public function_summary <funct_state_d *> |
132 | { | |
133 | public: | |
134 | funct_state_summary_t (symbol_table *symtab): | |
135 | function_summary <funct_state_d *> (symtab) {} | |
136 | ||
137 | virtual void insert (cgraph_node *, funct_state_d *state); | |
138 | virtual void duplicate (cgraph_node *src_node, cgraph_node *dst_node, | |
139 | funct_state_d *src_data, | |
140 | funct_state_d *dst_data); | |
141 | }; | |
cb886925 | 142 | |
16f72bd0 | 143 | static funct_state_summary_t *funct_state_summaries = NULL; |
cb886925 | 144 | |
415309e2 | 145 | static bool gate_pure_const (void); |
146 | ||
7620bc82 | 147 | namespace { |
148 | ||
149 | const pass_data pass_data_ipa_pure_const = | |
415309e2 | 150 | { |
151 | IPA_PASS, /* type */ | |
152 | "pure-const", /* name */ | |
153 | OPTGROUP_NONE, /* optinfo_flags */ | |
154 | TV_IPA_PURE_CONST, /* tv_id */ | |
155 | 0, /* properties_required */ | |
156 | 0, /* properties_provided */ | |
157 | 0, /* properties_destroyed */ | |
158 | 0, /* todo_flags_start */ | |
159 | 0, /* todo_flags_finish */ | |
160 | }; | |
161 | ||
7620bc82 | 162 | class pass_ipa_pure_const : public ipa_opt_pass_d |
415309e2 | 163 | { |
164 | public: | |
165 | pass_ipa_pure_const(gcc::context *ctxt); | |
166 | ||
167 | /* opt_pass methods: */ | |
168 | bool gate (function *) { return gate_pure_const (); } | |
169 | unsigned int execute (function *fun); | |
170 | ||
171 | void register_hooks (void); | |
172 | ||
173 | private: | |
174 | bool init_p; | |
415309e2 | 175 | }; // class pass_ipa_pure_const |
176 | ||
7620bc82 | 177 | } // anon namespace |
178 | ||
2c06958d | 179 | /* Try to guess if function body will always be visible to compiler |
180 | when compiling the call and whether compiler will be able | |
181 | to propagate the information by itself. */ | |
182 | ||
183 | static bool | |
184 | function_always_visible_to_compiler_p (tree decl) | |
185 | { | |
60722a03 | 186 | return (!TREE_PUBLIC (decl) || DECL_DECLARED_INLINE_P (decl) |
187 | || DECL_COMDAT (decl)); | |
2c06958d | 188 | } |
189 | ||
190 | /* Emit suggestion about attribute ATTRIB_NAME for DECL. KNOWN_FINITE | |
191 | is true if the function is known to be finite. The diagnostic is | |
431205b7 | 192 | controlled by OPTION. WARNED_ABOUT is a hash_set<tree> unique for |
2c06958d | 193 | OPTION, this function may initialize it and it is always returned |
194 | by the function. */ | |
195 | ||
431205b7 | 196 | static hash_set<tree> * |
2c06958d | 197 | suggest_attribute (int option, tree decl, bool known_finite, |
431205b7 | 198 | hash_set<tree> *warned_about, |
2c06958d | 199 | const char * attrib_name) |
200 | { | |
2c5d2e39 | 201 | if (!option_enabled (option, &global_options)) |
2c06958d | 202 | return warned_about; |
203 | if (TREE_THIS_VOLATILE (decl) | |
204 | || (known_finite && function_always_visible_to_compiler_p (decl))) | |
205 | return warned_about; | |
206 | ||
207 | if (!warned_about) | |
431205b7 | 208 | warned_about = new hash_set<tree>; |
209 | if (warned_about->contains (decl)) | |
2c06958d | 210 | return warned_about; |
431205b7 | 211 | warned_about->add (decl); |
2c06958d | 212 | warning_at (DECL_SOURCE_LOCATION (decl), |
213 | option, | |
214 | known_finite | |
ca1f4c7a | 215 | ? G_("function might be candidate for attribute %qs") |
216 | : G_("function might be candidate for attribute %qs" | |
217 | " if it is known to return normally"), attrib_name); | |
2c06958d | 218 | return warned_about; |
219 | } | |
220 | ||
221 | /* Emit suggestion about __attribute_((pure)) for DECL. KNOWN_FINITE | |
222 | is true if the function is known to be finite. */ | |
223 | ||
224 | static void | |
225 | warn_function_pure (tree decl, bool known_finite) | |
226 | { | |
2acafe26 | 227 | /* Declaring a void function pure makes no sense and is diagnosed |
228 | by -Wattributes because calling it would have no effect. */ | |
229 | if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) | |
230 | return; | |
2c06958d | 231 | |
2acafe26 | 232 | static hash_set<tree> *warned_about; |
233 | warned_about | |
2c06958d | 234 | = suggest_attribute (OPT_Wsuggest_attribute_pure, decl, |
235 | known_finite, warned_about, "pure"); | |
236 | } | |
237 | ||
238 | /* Emit suggestion about __attribute_((const)) for DECL. KNOWN_FINITE | |
239 | is true if the function is known to be finite. */ | |
240 | ||
241 | static void | |
242 | warn_function_const (tree decl, bool known_finite) | |
243 | { | |
2acafe26 | 244 | /* Declaring a void function const makes no sense is diagnosed |
245 | by -Wattributes because calling it would have no effect. */ | |
246 | if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (decl)))) | |
247 | return; | |
248 | ||
431205b7 | 249 | static hash_set<tree> *warned_about; |
2acafe26 | 250 | warned_about |
2c06958d | 251 | = suggest_attribute (OPT_Wsuggest_attribute_const, decl, |
252 | known_finite, warned_about, "const"); | |
253 | } | |
43d60d64 | 254 | |
bd5ef087 | 255 | /* Emit suggestion about __attribute__((malloc)) for DECL. */ |
256 | ||
257 | static void | |
258 | warn_function_malloc (tree decl) | |
259 | { | |
260 | static hash_set<tree> *warned_about; | |
261 | warned_about | |
262 | = suggest_attribute (OPT_Wsuggest_attribute_malloc, decl, | |
9deb0d09 | 263 | true, warned_about, "malloc"); |
bd5ef087 | 264 | } |
265 | ||
266 | /* Emit suggestion about __attribute__((noreturn)) for DECL. */ | |
267 | ||
64641360 | 268 | static void |
43d60d64 | 269 | warn_function_noreturn (tree decl) |
270 | { | |
313dfc4e | 271 | tree original_decl = decl; |
272 | ||
431205b7 | 273 | static hash_set<tree> *warned_about; |
08c6cbd2 | 274 | if (!lang_hooks.missing_noreturn_ok_p (decl) |
275 | && targetm.warn_func_return (decl)) | |
43d60d64 | 276 | warned_about |
313dfc4e | 277 | = suggest_attribute (OPT_Wsuggest_attribute_noreturn, original_decl, |
43d60d64 | 278 | true, warned_about, "noreturn"); |
279 | } | |
9631926a | 280 | |
60722a03 | 281 | void |
282 | warn_function_cold (tree decl) | |
283 | { | |
284 | tree original_decl = decl; | |
285 | ||
60722a03 | 286 | static hash_set<tree> *warned_about; |
287 | warned_about | |
288 | = suggest_attribute (OPT_Wsuggest_attribute_cold, original_decl, | |
289 | true, warned_about, "cold"); | |
290 | } | |
291 | ||
f0b5f617 | 292 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
f7d118a9 | 293 | variable T is legal in a function that is either pure or const. */ |
294 | ||
48e1416a | 295 | static inline void |
296 | check_decl (funct_state local, | |
023a28e1 | 297 | tree t, bool checking_write, bool ipa) |
f7d118a9 | 298 | { |
f7d118a9 | 299 | /* Do not want to do anything with volatile except mark any |
300 | function that uses one to be not const or pure. */ | |
48e1416a | 301 | if (TREE_THIS_VOLATILE (t)) |
302 | { | |
f7d118a9 | 303 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 304 | if (dump_file) |
f7d67aae | 305 | fprintf (dump_file, " Volatile operand is not const/pure\n"); |
f7d118a9 | 306 | return; |
307 | } | |
308 | ||
309 | /* Do not care about a local automatic that is not static. */ | |
310 | if (!TREE_STATIC (t) && !DECL_EXTERNAL (t)) | |
311 | return; | |
312 | ||
b5cebd44 | 313 | /* If the variable has the "used" attribute, treat it as if it had a |
314 | been touched by the devil. */ | |
83a23b05 | 315 | if (DECL_PRESERVE_P (t)) |
b5cebd44 | 316 | { |
317 | local->pure_const_state = IPA_NEITHER; | |
318 | if (dump_file) | |
319 | fprintf (dump_file, " Used static/global variable is not const/pure\n"); | |
320 | return; | |
321 | } | |
322 | ||
023a28e1 | 323 | /* In IPA mode we are not interested in checking actual loads and stores; |
324 | they will be processed at propagation time using ipa_ref. */ | |
325 | if (ipa) | |
326 | return; | |
327 | ||
f7d118a9 | 328 | /* Since we have dealt with the locals and params cases above, if we |
329 | are CHECKING_WRITE, this cannot be a pure or constant | |
330 | function. */ | |
48e1416a | 331 | if (checking_write) |
bc17fd99 | 332 | { |
333 | local->pure_const_state = IPA_NEITHER; | |
b5cebd44 | 334 | if (dump_file) |
335 | fprintf (dump_file, " static/global memory write is not const/pure\n"); | |
bc17fd99 | 336 | return; |
337 | } | |
f7d118a9 | 338 | |
339 | if (DECL_EXTERNAL (t) || TREE_PUBLIC (t)) | |
340 | { | |
b5cebd44 | 341 | /* Readonly reads are safe. */ |
7d136f71 | 342 | if (TREE_READONLY (t)) |
b5cebd44 | 343 | return; /* Read of a constant, do not change the function state. */ |
48e1416a | 344 | else |
f7d118a9 | 345 | { |
b5cebd44 | 346 | if (dump_file) |
347 | fprintf (dump_file, " global memory read is not const\n"); | |
f7d118a9 | 348 | /* Just a regular read. */ |
349 | if (local->pure_const_state == IPA_CONST) | |
350 | local->pure_const_state = IPA_PURE; | |
351 | } | |
352 | } | |
b5cebd44 | 353 | else |
354 | { | |
355 | /* Compilation level statics can be read if they are readonly | |
356 | variables. */ | |
357 | if (TREE_READONLY (t)) | |
358 | return; | |
359 | ||
360 | if (dump_file) | |
361 | fprintf (dump_file, " static memory read is not const\n"); | |
362 | /* Just a regular read. */ | |
363 | if (local->pure_const_state == IPA_CONST) | |
364 | local->pure_const_state = IPA_PURE; | |
365 | } | |
f7d118a9 | 366 | } |
367 | ||
f7d118a9 | 368 | |
b5cebd44 | 369 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
370 | variable T is legal in a function that is either pure or const. */ | |
f7d118a9 | 371 | |
48e1416a | 372 | static inline void |
5ed0b345 | 373 | check_op (funct_state local, tree t, bool checking_write) |
f7d118a9 | 374 | { |
3ae61172 | 375 | t = get_base_address (t); |
376 | if (t && TREE_THIS_VOLATILE (t)) | |
f7d118a9 | 377 | { |
5ed0b345 | 378 | local->pure_const_state = IPA_NEITHER; |
379 | if (dump_file) | |
380 | fprintf (dump_file, " Volatile indirect ref is not const/pure\n"); | |
381 | return; | |
382 | } | |
3ae61172 | 383 | else if (t |
182cf5a9 | 384 | && (INDIRECT_REF_P (t) || TREE_CODE (t) == MEM_REF) |
3ae61172 | 385 | && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME |
386 | && !ptr_deref_may_alias_global_p (TREE_OPERAND (t, 0))) | |
387 | { | |
388 | if (dump_file) | |
389 | fprintf (dump_file, " Indirect ref to local memory is OK\n"); | |
390 | return; | |
391 | } | |
5ed0b345 | 392 | else if (checking_write) |
393 | { | |
394 | local->pure_const_state = IPA_NEITHER; | |
395 | if (dump_file) | |
396 | fprintf (dump_file, " Indirect ref write is not const/pure\n"); | |
397 | return; | |
398 | } | |
399 | else | |
400 | { | |
401 | if (dump_file) | |
402 | fprintf (dump_file, " Indirect ref read is not const\n"); | |
403 | if (local->pure_const_state == IPA_CONST) | |
404 | local->pure_const_state = IPA_PURE; | |
f7d118a9 | 405 | } |
406 | } | |
407 | ||
023a28e1 | 408 | /* compute state based on ECF FLAGS and store to STATE and LOOPING. */ |
409 | ||
410 | static void | |
411 | state_from_flags (enum pure_const_state_e *state, bool *looping, | |
412 | int flags, bool cannot_lead_to_return) | |
413 | { | |
414 | *looping = false; | |
415 | if (flags & ECF_LOOPING_CONST_OR_PURE) | |
416 | { | |
417 | *looping = true; | |
418 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
f7d67aae | 419 | fprintf (dump_file, " looping\n"); |
023a28e1 | 420 | } |
421 | if (flags & ECF_CONST) | |
422 | { | |
423 | *state = IPA_CONST; | |
424 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
425 | fprintf (dump_file, " const\n"); | |
426 | } | |
427 | else if (flags & ECF_PURE) | |
428 | { | |
429 | *state = IPA_PURE; | |
430 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
431 | fprintf (dump_file, " pure\n"); | |
432 | } | |
433 | else if (cannot_lead_to_return) | |
434 | { | |
435 | *state = IPA_PURE; | |
436 | *looping = true; | |
437 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
438 | fprintf (dump_file, " ignoring side effects->pure looping\n"); | |
439 | } | |
440 | else | |
441 | { | |
442 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
9631926a | 443 | fprintf (dump_file, " neither\n"); |
023a28e1 | 444 | *state = IPA_NEITHER; |
445 | *looping = true; | |
446 | } | |
447 | } | |
448 | ||
449 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
450 | into STATE and LOOPING better of the two variants. | |
451 | Be sure to merge looping correctly. IPA_NEITHER functions | |
452 | have looping 0 even if they don't have to return. */ | |
453 | ||
454 | static inline void | |
455 | better_state (enum pure_const_state_e *state, bool *looping, | |
456 | enum pure_const_state_e state2, bool looping2) | |
457 | { | |
458 | if (state2 < *state) | |
459 | { | |
460 | if (*state == IPA_NEITHER) | |
461 | *looping = looping2; | |
462 | else | |
463 | *looping = MIN (*looping, looping2); | |
26fc128e | 464 | *state = state2; |
023a28e1 | 465 | } |
466 | else if (state2 != IPA_NEITHER) | |
467 | *looping = MIN (*looping, looping2); | |
468 | } | |
469 | ||
470 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
8b4ee73c | 471 | into STATE and LOOPING worse of the two variants. |
472 | N is the actual node called. */ | |
023a28e1 | 473 | |
474 | static inline void | |
475 | worse_state (enum pure_const_state_e *state, bool *looping, | |
8b4ee73c | 476 | enum pure_const_state_e state2, bool looping2, |
477 | struct symtab_node *from, | |
478 | struct symtab_node *to) | |
023a28e1 | 479 | { |
8b4ee73c | 480 | /* Consider function: |
481 | ||
482 | bool a(int *p) | |
483 | { | |
484 | return *p==*p; | |
485 | } | |
486 | ||
487 | During early optimization we will turn this into: | |
488 | ||
489 | bool a(int *p) | |
490 | { | |
491 | return true; | |
492 | } | |
493 | ||
494 | Now if this function will be detected as CONST however when interposed it | |
495 | may end up being just pure. We always must assume the worst scenario here. | |
496 | */ | |
497 | if (*state == IPA_CONST && state2 == IPA_CONST | |
498 | && to && !TREE_READONLY (to->decl) && !to->binds_to_current_def_p (from)) | |
499 | { | |
500 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
501 | fprintf (dump_file, "Dropping state to PURE because call to %s may not " | |
502 | "bind to current def.\n", to->name ()); | |
503 | state2 = IPA_PURE; | |
504 | } | |
023a28e1 | 505 | *state = MAX (*state, state2); |
506 | *looping = MAX (*looping, looping2); | |
507 | } | |
508 | ||
0a10fd82 | 509 | /* Recognize special cases of builtins that are by themselves not pure or const |
7dd42908 | 510 | but function using them is. */ |
511 | static bool | |
a53e7471 | 512 | special_builtin_state (enum pure_const_state_e *state, bool *looping, |
7dd42908 | 513 | tree callee) |
514 | { | |
515 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
516 | switch (DECL_FUNCTION_CODE (callee)) | |
517 | { | |
518 | case BUILT_IN_RETURN: | |
519 | case BUILT_IN_UNREACHABLE: | |
2b34677f | 520 | CASE_BUILT_IN_ALLOCA: |
7dd42908 | 521 | case BUILT_IN_STACK_SAVE: |
522 | case BUILT_IN_STACK_RESTORE: | |
523 | case BUILT_IN_EH_POINTER: | |
524 | case BUILT_IN_EH_FILTER: | |
525 | case BUILT_IN_UNWIND_RESUME: | |
526 | case BUILT_IN_CXA_END_CLEANUP: | |
527 | case BUILT_IN_EH_COPY_VALUES: | |
528 | case BUILT_IN_FRAME_ADDRESS: | |
529 | case BUILT_IN_APPLY: | |
530 | case BUILT_IN_APPLY_ARGS: | |
a940fdc7 | 531 | case BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT: |
532 | case BUILT_IN_ASAN_AFTER_DYNAMIC_INIT: | |
7dd42908 | 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; | |
5213d6c9 | 540 | default: |
541 | break; | |
7dd42908 | 542 | } |
543 | return false; | |
544 | } | |
545 | ||
f7d118a9 | 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 | |
1a91d914 | 554 | check_call (funct_state local, gcall *call, bool ipa) |
f7d118a9 | 555 | { |
75a70cf9 | 556 | int flags = gimple_call_flags (call); |
b5cebd44 | 557 | tree callee_t = gimple_call_fndecl (call); |
aac19106 | 558 | bool possibly_throws = stmt_could_throw_p (cfun, call); |
b5cebd44 | 559 | bool possibly_throws_externally = (possibly_throws |
aac19106 | 560 | && stmt_can_throw_external (cfun, call)); |
f7d118a9 | 561 | |
b5cebd44 | 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 | { | |
cbeb677e | 569 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 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 | } | |
48e1416a | 583 | |
f7d118a9 | 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 | |
48e1416a | 587 | them, otherwise we will compute our own information. |
588 | ||
f7d118a9 | 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 | |
48e1416a | 593 | graph. */ |
f7d118a9 | 594 | if (callee_t) |
595 | { | |
7dd42908 | 596 | enum pure_const_state_e call_state; |
597 | bool call_looping; | |
598 | ||
04c849b3 | 599 | if (gimple_call_builtin_p (call, BUILT_IN_NORMAL) |
600 | && !nonfreeing_call_p (call)) | |
601 | local->can_free = true; | |
602 | ||
a53e7471 | 603 | if (special_builtin_state (&call_state, &call_looping, callee_t)) |
7dd42908 | 604 | { |
605 | worse_state (&local->pure_const_state, &local->looping, | |
8b4ee73c | 606 | call_state, call_looping, |
607 | NULL, NULL); | |
7dd42908 | 608 | return; |
609 | } | |
f7d118a9 | 610 | /* When bad things happen to bad functions, they cannot be const |
611 | or pure. */ | |
612 | if (setjmp_call_p (callee_t)) | |
9c2a0c05 | 613 | { |
b5cebd44 | 614 | if (dump_file) |
615 | fprintf (dump_file, " setjmp is not const/pure\n"); | |
616 | local->looping = true; | |
9c2a0c05 | 617 | local->pure_const_state = IPA_NEITHER; |
9c2a0c05 | 618 | } |
f7d118a9 | 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: | |
b5cebd44 | 625 | if (dump_file) |
626 | fprintf (dump_file, " longjmp and nonlocal goto is not const/pure\n"); | |
f7d118a9 | 627 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 628 | local->looping = true; |
f7d118a9 | 629 | break; |
630 | default: | |
631 | break; | |
632 | } | |
633 | } | |
04c849b3 | 634 | else if (gimple_call_internal_p (call) && !nonfreeing_call_p (call)) |
635 | local->can_free = true; | |
f7d118a9 | 636 | |
b5cebd44 | 637 | /* When not in IPA mode, we can still handle self recursion. */ |
e9de52cc | 638 | if (!ipa && callee_t |
639 | && recursive_call_p (current_function_decl, callee_t)) | |
2c06958d | 640 | { |
641 | if (dump_file) | |
642 | fprintf (dump_file, " Recursive call can loop.\n"); | |
643 | local->looping = true; | |
644 | } | |
0a10fd82 | 645 | /* Either callee is unknown or we are doing local analysis. |
ef378c27 | 646 | Look to see if there are any bits available for the callee (such as by |
647 | declaration or because it is builtin) and process solely on the basis of | |
621733d8 | 648 | those bits. Handle internal calls always, those calls don't have |
649 | corresponding cgraph edges and thus aren't processed during | |
650 | the propagation. */ | |
651 | else if (!ipa || gimple_call_internal_p (call)) | |
f7d118a9 | 652 | { |
023a28e1 | 653 | enum pure_const_state_e call_state; |
654 | bool call_looping; | |
cbeb677e | 655 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 656 | { |
657 | if (dump_file) | |
658 | fprintf (dump_file, " can throw; looping\n"); | |
659 | local->looping = true; | |
660 | } | |
661 | if (possibly_throws_externally) | |
662 | { | |
663 | if (dump_file) | |
664 | { | |
e38def9c | 665 | fprintf (dump_file, " can throw externally to lp %i\n", |
666 | lookup_stmt_eh_lp (call)); | |
b5cebd44 | 667 | if (callee_t) |
668 | fprintf (dump_file, " callee:%s\n", | |
669 | IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (callee_t))); | |
670 | } | |
671 | local->can_throw = true; | |
672 | } | |
023a28e1 | 673 | if (dump_file && (dump_flags & TDF_DETAILS)) |
674 | fprintf (dump_file, " checking flags for call:"); | |
675 | state_from_flags (&call_state, &call_looping, flags, | |
676 | ((flags & (ECF_NORETURN | ECF_NOTHROW)) | |
677 | == (ECF_NORETURN | ECF_NOTHROW)) | |
678 | || (!flag_exceptions && (flags & ECF_NORETURN))); | |
679 | worse_state (&local->pure_const_state, &local->looping, | |
8b4ee73c | 680 | call_state, call_looping, NULL, NULL); |
f7d118a9 | 681 | } |
b5cebd44 | 682 | /* Direct functions calls are handled by IPA propagation. */ |
f7d118a9 | 683 | } |
684 | ||
023a28e1 | 685 | /* Wrapper around check_decl for loads in local more. */ |
5ed0b345 | 686 | |
687 | static bool | |
42acab1c | 688 | check_load (gimple *, tree op, tree, void *data) |
5ed0b345 | 689 | { |
690 | if (DECL_P (op)) | |
023a28e1 | 691 | check_decl ((funct_state)data, op, false, false); |
5ed0b345 | 692 | else |
693 | check_op ((funct_state)data, op, false); | |
694 | return false; | |
695 | } | |
696 | ||
023a28e1 | 697 | /* Wrapper around check_decl for stores in local more. */ |
5ed0b345 | 698 | |
699 | static bool | |
42acab1c | 700 | check_store (gimple *, tree op, tree, void *data) |
5ed0b345 | 701 | { |
702 | if (DECL_P (op)) | |
023a28e1 | 703 | check_decl ((funct_state)data, op, true, false); |
704 | else | |
705 | check_op ((funct_state)data, op, true); | |
706 | return false; | |
707 | } | |
708 | ||
709 | /* Wrapper around check_decl for loads in ipa mode. */ | |
710 | ||
711 | static bool | |
42acab1c | 712 | check_ipa_load (gimple *, tree op, tree, void *data) |
023a28e1 | 713 | { |
714 | if (DECL_P (op)) | |
715 | check_decl ((funct_state)data, op, false, true); | |
716 | else | |
717 | check_op ((funct_state)data, op, false); | |
718 | return false; | |
719 | } | |
720 | ||
721 | /* Wrapper around check_decl for stores in ipa mode. */ | |
722 | ||
723 | static bool | |
42acab1c | 724 | check_ipa_store (gimple *, tree op, tree, void *data) |
023a28e1 | 725 | { |
726 | if (DECL_P (op)) | |
727 | check_decl ((funct_state)data, op, true, true); | |
5ed0b345 | 728 | else |
729 | check_op ((funct_state)data, op, true); | |
730 | return false; | |
731 | } | |
732 | ||
dd277d48 | 733 | /* Look into pointer pointed to by GSIP and figure out what interesting side |
734 | effects it has. */ | |
b5cebd44 | 735 | static void |
736 | check_stmt (gimple_stmt_iterator *gsip, funct_state local, bool ipa) | |
f7d118a9 | 737 | { |
42acab1c | 738 | gimple *stmt = gsi_stmt (*gsip); |
f7d118a9 | 739 | |
9845d120 | 740 | if (is_gimple_debug (stmt)) |
741 | return; | |
742 | ||
73594827 | 743 | /* Do consider clobber as side effects before IPA, so we rather inline |
744 | C++ destructors and keep clobber semantics than eliminate them. | |
745 | ||
746 | TODO: We may get smarter during early optimizations on these and let | |
747 | functions containing only clobbers to be optimized more. This is a common | |
748 | case of C++ destructors. */ | |
749 | ||
750 | if ((ipa || cfun->after_inlining) && gimple_clobber_p (stmt)) | |
751 | return; | |
752 | ||
b5cebd44 | 753 | if (dump_file) |
f7d118a9 | 754 | { |
b5cebd44 | 755 | fprintf (dump_file, " scanning: "); |
1ffa4346 | 756 | print_gimple_stmt (dump_file, stmt, 0); |
b5cebd44 | 757 | } |
dd277d48 | 758 | |
541c6dbb | 759 | if (gimple_has_volatile_ops (stmt) |
760 | && !gimple_clobber_p (stmt)) | |
4b68df2e | 761 | { |
762 | local->pure_const_state = IPA_NEITHER; | |
763 | if (dump_file) | |
764 | fprintf (dump_file, " Volatile stmt is not const/pure\n"); | |
765 | } | |
766 | ||
5ed0b345 | 767 | /* Look for loads and stores. */ |
023a28e1 | 768 | walk_stmt_load_store_ops (stmt, local, |
769 | ipa ? check_ipa_load : check_load, | |
770 | ipa ? check_ipa_store : check_store); | |
b5cebd44 | 771 | |
772 | if (gimple_code (stmt) != GIMPLE_CALL | |
aac19106 | 773 | && stmt_could_throw_p (cfun, stmt)) |
b5cebd44 | 774 | { |
cbeb677e | 775 | if (cfun->can_throw_non_call_exceptions) |
b5cebd44 | 776 | { |
777 | if (dump_file) | |
10f4615f | 778 | fprintf (dump_file, " can throw; looping\n"); |
b5cebd44 | 779 | local->looping = true; |
780 | } | |
aac19106 | 781 | if (stmt_can_throw_external (cfun, stmt)) |
b5cebd44 | 782 | { |
783 | if (dump_file) | |
10f4615f | 784 | fprintf (dump_file, " can throw externally\n"); |
b5cebd44 | 785 | local->can_throw = true; |
786 | } | |
10f4615f | 787 | else |
788 | if (dump_file) | |
789 | fprintf (dump_file, " can throw\n"); | |
75a70cf9 | 790 | } |
75a70cf9 | 791 | switch (gimple_code (stmt)) |
792 | { | |
b5cebd44 | 793 | case GIMPLE_CALL: |
1a91d914 | 794 | check_call (local, as_a <gcall *> (stmt), ipa); |
f7d118a9 | 795 | break; |
75a70cf9 | 796 | case GIMPLE_LABEL: |
1a91d914 | 797 | if (DECL_NONLOCAL (gimple_label_label (as_a <glabel *> (stmt)))) |
f7d118a9 | 798 | /* Target of long jump. */ |
9c2a0c05 | 799 | { |
b5cebd44 | 800 | if (dump_file) |
10f4615f | 801 | fprintf (dump_file, " nonlocal label is not const/pure\n"); |
9c2a0c05 | 802 | local->pure_const_state = IPA_NEITHER; |
9c2a0c05 | 803 | } |
f7d118a9 | 804 | break; |
75a70cf9 | 805 | case GIMPLE_ASM: |
1a91d914 | 806 | if (gimple_asm_clobbers_memory_p (as_a <gasm *> (stmt))) |
b5cebd44 | 807 | { |
97cf41ec | 808 | if (dump_file) |
10f4615f | 809 | fprintf (dump_file, " memory asm clobber is not const/pure\n"); |
97cf41ec | 810 | /* Abandon all hope, ye who enter here. */ |
811 | local->pure_const_state = IPA_NEITHER; | |
04c849b3 | 812 | local->can_free = true; |
b5cebd44 | 813 | } |
1a91d914 | 814 | if (gimple_asm_volatile_p (as_a <gasm *> (stmt))) |
b5cebd44 | 815 | { |
816 | if (dump_file) | |
10f4615f | 817 | fprintf (dump_file, " volatile is not const/pure\n"); |
b5cebd44 | 818 | /* Abandon all hope, ye who enter here. */ |
819 | local->pure_const_state = IPA_NEITHER; | |
04c849b3 | 820 | local->looping = true; |
821 | local->can_free = true; | |
b5cebd44 | 822 | } |
823 | return; | |
f7d118a9 | 824 | default: |
825 | break; | |
826 | } | |
f7d118a9 | 827 | } |
828 | ||
bd5ef087 | 829 | /* Check that RETVAL is used only in STMT and in comparisons against 0. |
830 | RETVAL is return value of the function and STMT is return stmt. */ | |
831 | ||
832 | static bool | |
833 | check_retval_uses (tree retval, gimple *stmt) | |
834 | { | |
835 | imm_use_iterator use_iter; | |
836 | gimple *use_stmt; | |
837 | ||
838 | FOR_EACH_IMM_USE_STMT (use_stmt, use_iter, retval) | |
839 | if (gcond *cond = dyn_cast<gcond *> (use_stmt)) | |
840 | { | |
841 | tree op2 = gimple_cond_rhs (cond); | |
842 | if (!integer_zerop (op2)) | |
843 | RETURN_FROM_IMM_USE_STMT (use_iter, false); | |
844 | } | |
845 | else if (gassign *ga = dyn_cast<gassign *> (use_stmt)) | |
846 | { | |
847 | enum tree_code code = gimple_assign_rhs_code (ga); | |
848 | if (TREE_CODE_CLASS (code) != tcc_comparison) | |
849 | RETURN_FROM_IMM_USE_STMT (use_iter, false); | |
850 | if (!integer_zerop (gimple_assign_rhs2 (ga))) | |
851 | RETURN_FROM_IMM_USE_STMT (use_iter, false); | |
852 | } | |
853 | else if (is_gimple_debug (use_stmt)) | |
854 | ; | |
855 | else if (use_stmt != stmt) | |
856 | RETURN_FROM_IMM_USE_STMT (use_iter, false); | |
857 | ||
858 | return true; | |
859 | } | |
860 | ||
861 | /* malloc_candidate_p() checks if FUN can possibly be annotated with malloc | |
862 | attribute. Currently this function does a very conservative analysis. | |
863 | FUN is considered to be a candidate if | |
864 | 1) It returns a value of pointer type. | |
865 | 2) SSA_NAME_DEF_STMT (return_value) is either a function call or | |
866 | a phi, and element of phi is either NULL or | |
867 | SSA_NAME_DEF_STMT(element) is function call. | |
868 | 3) The return-value has immediate uses only within comparisons (gcond or gassign) | |
869 | and return_stmt (and likewise a phi arg has immediate use only within comparison | |
870 | or the phi stmt). */ | |
871 | ||
bd5ef087 | 872 | #define DUMP_AND_RETURN(reason) \ |
873 | { \ | |
874 | if (dump_file && (dump_flags & TDF_DETAILS)) \ | |
d51fd3fc | 875 | fprintf (dump_file, "\n%s is not a malloc candidate, reason: %s\n", \ |
876 | (node->name()), (reason)); \ | |
bd5ef087 | 877 | return false; \ |
878 | } | |
879 | ||
18ea7971 | 880 | static bool |
881 | malloc_candidate_p_1 (function *fun, tree retval, gimple *ret_stmt, bool ipa) | |
882 | { | |
883 | cgraph_node *node = cgraph_node::get_create (fun->decl); | |
884 | ||
885 | if (!check_retval_uses (retval, ret_stmt)) | |
886 | DUMP_AND_RETURN("Return value has uses outside return stmt" | |
887 | " and comparisons against 0.") | |
888 | ||
889 | gimple *def = SSA_NAME_DEF_STMT (retval); | |
890 | ||
891 | if (gcall *call_stmt = dyn_cast<gcall *> (def)) | |
892 | { | |
893 | tree callee_decl = gimple_call_fndecl (call_stmt); | |
894 | if (!callee_decl) | |
895 | return false; | |
896 | ||
897 | if (!ipa && !DECL_IS_MALLOC (callee_decl)) | |
898 | DUMP_AND_RETURN("callee_decl does not have malloc attribute for" | |
899 | " non-ipa mode.") | |
900 | ||
901 | cgraph_edge *cs = node->get_edge (call_stmt); | |
902 | if (cs) | |
903 | { | |
904 | ipa_call_summary *es = ipa_call_summaries->get_create (cs); | |
905 | es->is_return_callee_uncaptured = true; | |
906 | } | |
907 | } | |
908 | ||
909 | else if (gphi *phi = dyn_cast<gphi *> (def)) | |
910 | { | |
911 | bool all_args_zero = true; | |
912 | for (unsigned i = 0; i < gimple_phi_num_args (phi); ++i) | |
913 | { | |
914 | tree arg = gimple_phi_arg_def (phi, i); | |
915 | if (integer_zerop (arg)) | |
916 | continue; | |
917 | ||
918 | all_args_zero = false; | |
919 | if (TREE_CODE (arg) != SSA_NAME) | |
920 | DUMP_AND_RETURN ("phi arg is not SSA_NAME."); | |
921 | if (!check_retval_uses (arg, phi)) | |
922 | DUMP_AND_RETURN ("phi arg has uses outside phi" | |
923 | " and comparisons against 0.") | |
924 | ||
925 | gimple *arg_def = SSA_NAME_DEF_STMT (arg); | |
926 | if (is_a<gphi *> (arg_def)) | |
927 | { | |
928 | if (!malloc_candidate_p_1 (fun, arg, phi, ipa)) | |
929 | DUMP_AND_RETURN ("nested phi fail") | |
930 | continue; | |
931 | } | |
932 | ||
933 | gcall *call_stmt = dyn_cast<gcall *> (arg_def); | |
934 | if (!call_stmt) | |
935 | DUMP_AND_RETURN ("phi arg is a not a call_stmt.") | |
936 | ||
937 | tree callee_decl = gimple_call_fndecl (call_stmt); | |
938 | if (!callee_decl) | |
939 | return false; | |
940 | if (!ipa && !DECL_IS_MALLOC (callee_decl)) | |
941 | DUMP_AND_RETURN("callee_decl does not have malloc attribute" | |
942 | " for non-ipa mode.") | |
943 | ||
944 | cgraph_edge *cs = node->get_edge (call_stmt); | |
945 | if (cs) | |
946 | { | |
947 | ipa_call_summary *es = ipa_call_summaries->get_create (cs); | |
948 | es->is_return_callee_uncaptured = true; | |
949 | } | |
950 | } | |
951 | ||
952 | if (all_args_zero) | |
953 | DUMP_AND_RETURN ("Return value is a phi with all args equal to 0.") | |
954 | } | |
955 | ||
956 | else | |
957 | DUMP_AND_RETURN("def_stmt of return value is not a call or phi-stmt.") | |
958 | ||
959 | return true; | |
960 | } | |
961 | ||
962 | static bool | |
963 | malloc_candidate_p (function *fun, bool ipa) | |
964 | { | |
965 | basic_block exit_block = EXIT_BLOCK_PTR_FOR_FN (fun); | |
966 | edge e; | |
967 | edge_iterator ei; | |
968 | cgraph_node *node = cgraph_node::get_create (fun->decl); | |
969 | ||
d51fd3fc | 970 | if (EDGE_COUNT (exit_block->preds) == 0 |
971 | || !flag_delete_null_pointer_checks) | |
bd5ef087 | 972 | return false; |
973 | ||
974 | FOR_EACH_EDGE (e, ei, exit_block->preds) | |
975 | { | |
976 | gimple_stmt_iterator gsi = gsi_last_bb (e->src); | |
977 | greturn *ret_stmt = dyn_cast<greturn *> (gsi_stmt (gsi)); | |
978 | ||
979 | if (!ret_stmt) | |
980 | return false; | |
981 | ||
982 | tree retval = gimple_return_retval (ret_stmt); | |
983 | if (!retval) | |
984 | DUMP_AND_RETURN("No return value.") | |
985 | ||
986 | if (TREE_CODE (retval) != SSA_NAME | |
987 | || TREE_CODE (TREE_TYPE (retval)) != POINTER_TYPE) | |
988 | DUMP_AND_RETURN("Return value is not SSA_NAME or not a pointer type.") | |
989 | ||
18ea7971 | 990 | if (!malloc_candidate_p_1 (fun, retval, ret_stmt, ipa)) |
991 | return false; | |
bd5ef087 | 992 | } |
993 | ||
994 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
995 | fprintf (dump_file, "\nFound %s to be candidate for malloc attribute\n", | |
996 | IDENTIFIER_POINTER (DECL_NAME (fun->decl))); | |
997 | return true; | |
bd5ef087 | 998 | } |
999 | ||
18ea7971 | 1000 | #undef DUMP_AND_RETURN |
cb886925 | 1001 | |
f7d118a9 | 1002 | /* This is the main routine for finding the reference patterns for |
1003 | global variables within a function FN. */ | |
1004 | ||
b5cebd44 | 1005 | static funct_state |
1006 | analyze_function (struct cgraph_node *fn, bool ipa) | |
f7d118a9 | 1007 | { |
02774f2d | 1008 | tree decl = fn->decl; |
b5cebd44 | 1009 | funct_state l; |
1010 | basic_block this_block; | |
f7d118a9 | 1011 | |
b5cebd44 | 1012 | l = XCNEW (struct funct_state_d); |
1013 | l->pure_const_state = IPA_CONST; | |
df9b545b | 1014 | l->state_previously_known = IPA_NEITHER; |
1015 | l->looping_previously_known = true; | |
b5cebd44 | 1016 | l->looping = false; |
1017 | l->can_throw = false; | |
04c849b3 | 1018 | l->can_free = false; |
91bf9d9a | 1019 | state_from_flags (&l->state_previously_known, &l->looping_previously_known, |
02774f2d | 1020 | flags_from_decl_or_type (fn->decl), |
415d1b9a | 1021 | fn->cannot_return_p ()); |
91bf9d9a | 1022 | |
02774f2d | 1023 | if (fn->thunk.thunk_p || fn->alias) |
91bf9d9a | 1024 | { |
1025 | /* Thunk gets propagated through, so nothing interesting happens. */ | |
1026 | gcc_assert (ipa); | |
cfd85d03 | 1027 | if (fn->thunk.thunk_p && fn->thunk.virtual_offset_p) |
1028 | l->pure_const_state = IPA_NEITHER; | |
91bf9d9a | 1029 | return l; |
1030 | } | |
f7d118a9 | 1031 | |
1032 | if (dump_file) | |
1033 | { | |
48e1416a | 1034 | fprintf (dump_file, "\n\n local analysis of %s\n ", |
f1c8b4d7 | 1035 | fn->name ()); |
f7d118a9 | 1036 | } |
48e1416a | 1037 | |
b5cebd44 | 1038 | push_cfun (DECL_STRUCT_FUNCTION (decl)); |
48e1416a | 1039 | |
fc00614f | 1040 | FOR_EACH_BB_FN (this_block, cfun) |
f7d118a9 | 1041 | { |
b5cebd44 | 1042 | gimple_stmt_iterator gsi; |
1043 | struct walk_stmt_info wi; | |
f7d118a9 | 1044 | |
9af5ce0c | 1045 | memset (&wi, 0, sizeof (wi)); |
b5cebd44 | 1046 | for (gsi = gsi_start_bb (this_block); |
1047 | !gsi_end_p (gsi); | |
1048 | gsi_next (&gsi)) | |
f7d118a9 | 1049 | { |
b5cebd44 | 1050 | check_stmt (&gsi, l, ipa); |
04c849b3 | 1051 | if (l->pure_const_state == IPA_NEITHER |
1052 | && l->looping | |
1053 | && l->can_throw | |
1054 | && l->can_free) | |
b5cebd44 | 1055 | goto end; |
f7d118a9 | 1056 | } |
1057 | } | |
dcccac3e | 1058 | |
1059 | end: | |
b5cebd44 | 1060 | if (l->pure_const_state != IPA_NEITHER) |
1061 | { | |
1062 | /* Const functions cannot have back edges (an | |
1063 | indication of possible infinite loop side | |
1064 | effect. */ | |
1065 | if (mark_dfs_back_edges ()) | |
c9263b6a | 1066 | { |
b1887855 | 1067 | /* Preheaders are needed for SCEV to work. |
0a10fd82 | 1068 | Simple latches and recorded exits improve chances that loop will |
8ff30f9a | 1069 | proved to be finite in testcases such as in loop-15.c |
1070 | and loop-24.c */ | |
1071 | loop_optimizer_init (LOOPS_HAVE_PREHEADERS | |
1072 | | LOOPS_HAVE_SIMPLE_LATCHES | |
b1887855 | 1073 | | LOOPS_HAVE_RECORDED_EXITS); |
c9263b6a | 1074 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1075 | flow_loops_dump (dump_file, NULL, 0); | |
1076 | if (mark_irreducible_loops ()) | |
1077 | { | |
1078 | if (dump_file) | |
1079 | fprintf (dump_file, " has irreducible loops\n"); | |
1080 | l->looping = true; | |
1081 | } | |
48e1416a | 1082 | else |
c9263b6a | 1083 | { |
c9263b6a | 1084 | struct loop *loop; |
1085 | scev_initialize (); | |
f21d4d00 | 1086 | FOR_EACH_LOOP (loop, 0) |
c9263b6a | 1087 | if (!finite_loop_p (loop)) |
1088 | { | |
1089 | if (dump_file) | |
8ff30f9a | 1090 | fprintf (dump_file, " can not prove finiteness of " |
1091 | "loop %i\n", loop->num); | |
c9263b6a | 1092 | l->looping =true; |
f21d4d00 | 1093 | break; |
c9263b6a | 1094 | } |
1095 | scev_finalize (); | |
1096 | } | |
1097 | loop_optimizer_finalize (); | |
1098 | } | |
b5cebd44 | 1099 | } |
1100 | ||
023a28e1 | 1101 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1102 | fprintf (dump_file, " checking previously known:"); | |
023a28e1 | 1103 | |
1104 | better_state (&l->pure_const_state, &l->looping, | |
1105 | l->state_previously_known, | |
1106 | l->looping_previously_known); | |
b5cebd44 | 1107 | if (TREE_NOTHROW (decl)) |
1108 | l->can_throw = false; | |
1109 | ||
bd5ef087 | 1110 | l->malloc_state = STATE_MALLOC_BOTTOM; |
1111 | if (DECL_IS_MALLOC (decl)) | |
1112 | l->malloc_state = STATE_MALLOC; | |
1113 | else if (ipa && malloc_candidate_p (DECL_STRUCT_FUNCTION (decl), true)) | |
1114 | l->malloc_state = STATE_MALLOC_TOP; | |
1115 | else if (malloc_candidate_p (DECL_STRUCT_FUNCTION (decl), false)) | |
1116 | l->malloc_state = STATE_MALLOC; | |
1117 | ||
b5cebd44 | 1118 | pop_cfun (); |
dcccac3e | 1119 | if (dump_file) |
1120 | { | |
b5cebd44 | 1121 | if (l->looping) |
1122 | fprintf (dump_file, "Function is locally looping.\n"); | |
1123 | if (l->can_throw) | |
1124 | fprintf (dump_file, "Function is locally throwing.\n"); | |
1125 | if (l->pure_const_state == IPA_CONST) | |
1126 | fprintf (dump_file, "Function is locally const.\n"); | |
1127 | if (l->pure_const_state == IPA_PURE) | |
1128 | fprintf (dump_file, "Function is locally pure.\n"); | |
04c849b3 | 1129 | if (l->can_free) |
1130 | fprintf (dump_file, "Function can locally free.\n"); | |
bd5ef087 | 1131 | if (l->malloc_state == STATE_MALLOC) |
1132 | fprintf (dump_file, "Function is locally malloc.\n"); | |
dcccac3e | 1133 | } |
b5cebd44 | 1134 | return l; |
f7d118a9 | 1135 | } |
1136 | ||
16f72bd0 | 1137 | void |
1138 | funct_state_summary_t::insert (cgraph_node *node, funct_state_d *state) | |
50828ed8 | 1139 | { |
50828ed8 | 1140 | /* There are some shared nodes, in particular the initializers on |
1141 | static declarations. We do not need to scan them more than once | |
1142 | since all we would be interested in are the addressof | |
1143 | operations. */ | |
8b4ee73c | 1144 | if (opt_for_fn (node->decl, flag_ipa_pure_const)) |
86844d6c | 1145 | { |
16f72bd0 | 1146 | funct_state_d *a = analyze_function (node, true); |
1147 | new (state) funct_state_d (*a); | |
1148 | free (a); | |
86844d6c | 1149 | } |
1150 | } | |
1151 | ||
1152 | /* Called when new clone is inserted to callgraph late. */ | |
1153 | ||
16f72bd0 | 1154 | void |
1155 | funct_state_summary_t::duplicate (cgraph_node *, cgraph_node *, | |
1156 | funct_state_d *src_data, | |
1157 | funct_state_d *dst_data) | |
86844d6c | 1158 | { |
16f72bd0 | 1159 | new (dst_data) funct_state_d (*src_data); |
86844d6c | 1160 | } |
1161 | ||
f7d118a9 | 1162 | \f |
415309e2 | 1163 | void |
1164 | pass_ipa_pure_const:: | |
7bfefa9d | 1165 | register_hooks (void) |
f7d118a9 | 1166 | { |
7bfefa9d | 1167 | if (init_p) |
1168 | return; | |
1169 | ||
1170 | init_p = true; | |
f7d118a9 | 1171 | |
16f72bd0 | 1172 | funct_state_summaries = new funct_state_summary_t (symtab); |
7bfefa9d | 1173 | } |
1174 | ||
1175 | ||
1176 | /* Analyze each function in the cgraph to see if it is locally PURE or | |
1177 | CONST. */ | |
1178 | ||
48e1416a | 1179 | static void |
80880eb6 | 1180 | pure_const_generate_summary (void) |
7bfefa9d | 1181 | { |
1182 | struct cgraph_node *node; | |
1183 | ||
415309e2 | 1184 | pass_ipa_pure_const *pass = static_cast <pass_ipa_pure_const *> (current_pass); |
1185 | pass->register_hooks (); | |
7bfefa9d | 1186 | |
48e1416a | 1187 | /* Process all of the functions. |
f7d118a9 | 1188 | |
415d1b9a | 1189 | We process AVAIL_INTERPOSABLE functions. We can not use the results |
ef378c27 | 1190 | by default, but the info can be used at LTO with -fwhole-program or |
0a10fd82 | 1191 | when function got cloned and the clone is AVAILABLE. */ |
ef378c27 | 1192 | |
7c455d87 | 1193 | FOR_EACH_DEFINED_FUNCTION (node) |
8b4ee73c | 1194 | if (opt_for_fn (node->decl, flag_ipa_pure_const)) |
16f72bd0 | 1195 | { |
1196 | funct_state_d *a = analyze_function (node, true); | |
1197 | new (funct_state_summaries->get_create (node)) funct_state_d (*a); | |
1198 | free (a); | |
1199 | } | |
cb886925 | 1200 | } |
1201 | ||
7bfefa9d | 1202 | |
1203 | /* Serialize the ipa info for lto. */ | |
1204 | ||
1205 | static void | |
eab36a5a | 1206 | pure_const_write_summary (void) |
7bfefa9d | 1207 | { |
1208 | struct cgraph_node *node; | |
1209 | struct lto_simple_output_block *ob | |
1210 | = lto_create_simple_output_block (LTO_section_ipa_pure_const); | |
1211 | unsigned int count = 0; | |
eab36a5a | 1212 | lto_symtab_encoder_iterator lsei; |
1213 | lto_symtab_encoder_t encoder; | |
7bfefa9d | 1214 | |
eab36a5a | 1215 | encoder = lto_get_out_decl_state ()->symtab_node_encoder; |
1216 | ||
1217 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); | |
1218 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 1219 | { |
eab36a5a | 1220 | node = lsei_cgraph_node (lsei); |
16f72bd0 | 1221 | if (node->definition && funct_state_summaries->exists (node)) |
7bfefa9d | 1222 | count++; |
1223 | } | |
48e1416a | 1224 | |
7f385784 | 1225 | streamer_write_uhwi_stream (ob->main_stream, count); |
48e1416a | 1226 | |
7bfefa9d | 1227 | /* Process all of the functions. */ |
eab36a5a | 1228 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); |
1229 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 1230 | { |
eab36a5a | 1231 | node = lsei_cgraph_node (lsei); |
16f72bd0 | 1232 | funct_state_d *fs = funct_state_summaries->get (node); |
1233 | if (node->definition && fs != NULL) | |
7bfefa9d | 1234 | { |
30baba90 | 1235 | struct bitpack_d bp; |
7bfefa9d | 1236 | int node_ref; |
70225339 | 1237 | lto_symtab_encoder_t encoder; |
48e1416a | 1238 | |
70225339 | 1239 | encoder = ob->decl_state->symtab_node_encoder; |
02774f2d | 1240 | node_ref = lto_symtab_encoder_encode (encoder, node); |
7f385784 | 1241 | streamer_write_uhwi_stream (ob->main_stream, node_ref); |
48e1416a | 1242 | |
7bfefa9d | 1243 | /* Note that flags will need to be read in the opposite |
1244 | order as we are pushing the bitflags into FLAGS. */ | |
30baba90 | 1245 | bp = bitpack_create (ob->main_stream); |
1246 | bp_pack_value (&bp, fs->pure_const_state, 2); | |
1247 | bp_pack_value (&bp, fs->state_previously_known, 2); | |
1248 | bp_pack_value (&bp, fs->looping_previously_known, 1); | |
1249 | bp_pack_value (&bp, fs->looping, 1); | |
1250 | bp_pack_value (&bp, fs->can_throw, 1); | |
04c849b3 | 1251 | bp_pack_value (&bp, fs->can_free, 1); |
bd5ef087 | 1252 | bp_pack_value (&bp, fs->malloc_state, 2); |
7f385784 | 1253 | streamer_write_bitpack (&bp); |
7bfefa9d | 1254 | } |
1255 | } | |
1256 | ||
1257 | lto_destroy_simple_output_block (ob); | |
1258 | } | |
1259 | ||
1260 | ||
1261 | /* Deserialize the ipa info for lto. */ | |
1262 | ||
48e1416a | 1263 | static void |
7bfefa9d | 1264 | pure_const_read_summary (void) |
1265 | { | |
1266 | struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); | |
1267 | struct lto_file_decl_data *file_data; | |
1268 | unsigned int j = 0; | |
1269 | ||
415309e2 | 1270 | pass_ipa_pure_const *pass = static_cast <pass_ipa_pure_const *> (current_pass); |
1271 | pass->register_hooks (); | |
1272 | ||
7bfefa9d | 1273 | while ((file_data = file_data_vec[j++])) |
1274 | { | |
1275 | const char *data; | |
1276 | size_t len; | |
1277 | struct lto_input_block *ib | |
48e1416a | 1278 | = lto_create_simple_input_block (file_data, |
1279 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1280 | &data, &len); |
1281 | if (ib) | |
1282 | { | |
1283 | unsigned int i; | |
7f385784 | 1284 | unsigned int count = streamer_read_uhwi (ib); |
7bfefa9d | 1285 | |
1286 | for (i = 0; i < count; i++) | |
1287 | { | |
1288 | unsigned int index; | |
1289 | struct cgraph_node *node; | |
30baba90 | 1290 | struct bitpack_d bp; |
7bfefa9d | 1291 | funct_state fs; |
70225339 | 1292 | lto_symtab_encoder_t encoder; |
7bfefa9d | 1293 | |
7f385784 | 1294 | index = streamer_read_uhwi (ib); |
70225339 | 1295 | encoder = file_data->symtab_node_encoder; |
415d1b9a | 1296 | node = dyn_cast<cgraph_node *> (lto_symtab_encoder_deref (encoder, |
1297 | index)); | |
7bfefa9d | 1298 | |
16f72bd0 | 1299 | fs = funct_state_summaries->get_create (node); |
7bfefa9d | 1300 | /* Note that the flags must be read in the opposite |
1301 | order in which they were written (the bitflags were | |
1302 | pushed into FLAGS). */ | |
7f385784 | 1303 | bp = streamer_read_bitpack (ib); |
7bfefa9d | 1304 | fs->pure_const_state |
30baba90 | 1305 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
7bfefa9d | 1306 | fs->state_previously_known |
30baba90 | 1307 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
1308 | fs->looping_previously_known = bp_unpack_value (&bp, 1); | |
1309 | fs->looping = bp_unpack_value (&bp, 1); | |
1310 | fs->can_throw = bp_unpack_value (&bp, 1); | |
04c849b3 | 1311 | fs->can_free = bp_unpack_value (&bp, 1); |
bd5ef087 | 1312 | fs->malloc_state |
1313 | = (enum malloc_state_e) bp_unpack_value (&bp, 2); | |
1314 | ||
fc94a528 | 1315 | if (dump_file) |
1316 | { | |
02774f2d | 1317 | int flags = flags_from_decl_or_type (node->decl); |
0e388735 | 1318 | fprintf (dump_file, "Read info for %s ", node->dump_name ()); |
fc94a528 | 1319 | if (flags & ECF_CONST) |
1320 | fprintf (dump_file, " const"); | |
1321 | if (flags & ECF_PURE) | |
1322 | fprintf (dump_file, " pure"); | |
1323 | if (flags & ECF_NOTHROW) | |
1324 | fprintf (dump_file, " nothrow"); | |
1325 | fprintf (dump_file, "\n pure const state: %s\n", | |
1326 | pure_const_names[fs->pure_const_state]); | |
1327 | fprintf (dump_file, " previously known state: %s\n", | |
8b4ee73c | 1328 | pure_const_names[fs->state_previously_known]); |
fc94a528 | 1329 | if (fs->looping) |
1330 | fprintf (dump_file," function is locally looping\n"); | |
1331 | if (fs->looping_previously_known) | |
1332 | fprintf (dump_file," function is previously known looping\n"); | |
1333 | if (fs->can_throw) | |
1334 | fprintf (dump_file," function is locally throwing\n"); | |
04c849b3 | 1335 | if (fs->can_free) |
1336 | fprintf (dump_file," function can locally free\n"); | |
bd5ef087 | 1337 | fprintf (dump_file, "\n malloc state: %s\n", |
1338 | malloc_state_names[fs->malloc_state]); | |
fc94a528 | 1339 | } |
7bfefa9d | 1340 | } |
1341 | ||
48e1416a | 1342 | lto_destroy_simple_input_block (file_data, |
1343 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1344 | ib, data, len); |
1345 | } | |
1346 | } | |
1347 | } | |
1348 | ||
355c1f40 | 1349 | /* We only propagate across edges that can throw externally and their callee |
1350 | is not interposable. */ | |
7bfefa9d | 1351 | |
17b28e52 | 1352 | static bool |
355c1f40 | 1353 | ignore_edge_for_nothrow (struct cgraph_edge *e) |
17b28e52 | 1354 | { |
355c1f40 | 1355 | if (!e->can_throw_external || TREE_NOTHROW (e->callee->decl)) |
1356 | return true; | |
1357 | ||
1358 | enum availability avail; | |
8b4ee73c | 1359 | cgraph_node *n = e->callee->function_or_virtual_thunk_symbol (&avail, |
1360 | e->caller); | |
ace7bf06 | 1361 | if (avail <= AVAIL_INTERPOSABLE || TREE_NOTHROW (n->decl)) |
1362 | return true; | |
1363 | return opt_for_fn (e->callee->decl, flag_non_call_exceptions) | |
1364 | && !e->callee->binds_to_current_def_p (e->caller); | |
17b28e52 | 1365 | } |
1366 | ||
b2c2e188 | 1367 | /* Return true if NODE is self recursive function. |
e9de52cc | 1368 | Indirectly recursive functions appears as non-trivial strongly |
1369 | connected components, so we need to care about self recursion | |
1370 | only. */ | |
a1e88032 | 1371 | |
1372 | static bool | |
1373 | self_recursive_p (struct cgraph_node *node) | |
1374 | { | |
1375 | struct cgraph_edge *e; | |
1376 | for (e = node->callees; e; e = e->next_callee) | |
415d1b9a | 1377 | if (e->callee->function_symbol () == node) |
a1e88032 | 1378 | return true; |
1379 | return false; | |
1380 | } | |
1381 | ||
366970c6 | 1382 | /* Return true if N is cdtor that is not const or pure. In this case we may |
1383 | need to remove unreachable function if it is marked const/pure. */ | |
1384 | ||
1385 | static bool | |
1386 | cdtor_p (cgraph_node *n, void *) | |
1387 | { | |
1388 | if (DECL_STATIC_CONSTRUCTOR (n->decl) || DECL_STATIC_DESTRUCTOR (n->decl)) | |
98b8f2a5 | 1389 | return ((!TREE_READONLY (n->decl) && !DECL_PURE_P (n->decl)) |
1390 | || DECL_LOOPING_CONST_OR_PURE_P (n->decl)); | |
366970c6 | 1391 | return false; |
1392 | } | |
1393 | ||
d2c6c2b4 | 1394 | /* We only propagate across edges with non-interposable callee. */ |
1395 | ||
1396 | static bool | |
1397 | ignore_edge_for_pure_const (struct cgraph_edge *e) | |
1398 | { | |
1399 | enum availability avail; | |
8b4ee73c | 1400 | e->callee->function_or_virtual_thunk_symbol (&avail, e->caller); |
d2c6c2b4 | 1401 | return (avail <= AVAIL_INTERPOSABLE); |
1402 | } | |
1403 | ||
1404 | ||
c0240443 | 1405 | /* Produce transitive closure over the callgraph and compute pure/const |
1406 | attributes. */ | |
023a28e1 | 1407 | |
366970c6 | 1408 | static bool |
c0240443 | 1409 | propagate_pure_const (void) |
cb886925 | 1410 | { |
1411 | struct cgraph_node *node; | |
1412 | struct cgraph_node *w; | |
1413 | struct cgraph_node **order = | |
35ee1c66 | 1414 | XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); |
cb886925 | 1415 | int order_pos; |
1416 | int i; | |
1417 | struct ipa_dfs_info * w_info; | |
366970c6 | 1418 | bool remove_p = false; |
aaa36a78 | 1419 | bool has_cdtor; |
cb886925 | 1420 | |
d2c6c2b4 | 1421 | order_pos = ipa_reduced_postorder (order, true, false, |
1422 | ignore_edge_for_pure_const); | |
f7d118a9 | 1423 | if (dump_file) |
1424 | { | |
415d1b9a | 1425 | cgraph_node::dump_cgraph (dump_file); |
48669653 | 1426 | ipa_print_order (dump_file, "reduced", order, order_pos); |
f7d118a9 | 1427 | } |
1428 | ||
9d75589a | 1429 | /* Propagate the local information through the call graph to produce |
f7d118a9 | 1430 | the global information. All the nodes within a cycle will have |
1431 | the same info so we collapse cycles first. Then we can do the | |
1432 | propagation in one pass from the leaves to the roots. */ | |
1433 | for (i = 0; i < order_pos; i++ ) | |
1434 | { | |
1435 | enum pure_const_state_e pure_const_state = IPA_CONST; | |
9c2a0c05 | 1436 | bool looping = false; |
54157bf1 | 1437 | int count = 0; |
f7d118a9 | 1438 | node = order[i]; |
1439 | ||
02774f2d | 1440 | if (node->alias) |
8c1fce46 | 1441 | continue; |
1442 | ||
fc94a528 | 1443 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1444 | fprintf (dump_file, "Starting cycle\n"); | |
1445 | ||
f7d118a9 | 1446 | /* Find the worst state for any node in the cycle. */ |
1447 | w = node; | |
023a28e1 | 1448 | while (w && pure_const_state != IPA_NEITHER) |
f7d118a9 | 1449 | { |
b5cebd44 | 1450 | struct cgraph_edge *e; |
023a28e1 | 1451 | struct cgraph_edge *ie; |
1452 | int i; | |
51ce5652 | 1453 | struct ipa_ref *ref = NULL; |
023a28e1 | 1454 | |
16f72bd0 | 1455 | funct_state w_l = funct_state_summaries->get_create (w); |
fc94a528 | 1456 | if (dump_file && (dump_flags & TDF_DETAILS)) |
0e388735 | 1457 | fprintf (dump_file, " Visiting %s state:%s looping %i\n", |
1458 | w->dump_name (), | |
fc94a528 | 1459 | pure_const_names[w_l->pure_const_state], |
1460 | w_l->looping); | |
f7d118a9 | 1461 | |
8b4ee73c | 1462 | /* First merge in function body properties. |
1463 | We are safe to pass NULL as FROM and TO because we will take care | |
1464 | of possible interposition when walking callees. */ | |
023a28e1 | 1465 | worse_state (&pure_const_state, &looping, |
8b4ee73c | 1466 | w_l->pure_const_state, w_l->looping, |
1467 | NULL, NULL); | |
023a28e1 | 1468 | if (pure_const_state == IPA_NEITHER) |
1469 | break; | |
1470 | ||
b5cebd44 | 1471 | count++; |
1472 | ||
023a28e1 | 1473 | /* We consider recursive cycles as possibly infinite. |
1474 | This might be relaxed since infinite recursion leads to stack | |
1475 | overflow. */ | |
b5cebd44 | 1476 | if (count > 1) |
1477 | looping = true; | |
48e1416a | 1478 | |
023a28e1 | 1479 | /* Now walk the edges and merge in callee properties. */ |
d2c6c2b4 | 1480 | for (e = w->callees; e && pure_const_state != IPA_NEITHER; |
1481 | e = e->next_callee) | |
f7d118a9 | 1482 | { |
b2c2e188 | 1483 | enum availability avail; |
cfd85d03 | 1484 | struct cgraph_node *y = e->callee-> |
8b4ee73c | 1485 | function_or_virtual_thunk_symbol (&avail, |
1486 | e->caller); | |
fc94a528 | 1487 | enum pure_const_state_e edge_state = IPA_CONST; |
1488 | bool edge_looping = false; | |
54157bf1 | 1489 | |
fc94a528 | 1490 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1491 | { | |
0e388735 | 1492 | fprintf (dump_file, " Call to %s", |
1493 | e->callee->dump_name ()); | |
fc94a528 | 1494 | } |
415d1b9a | 1495 | if (avail > AVAIL_INTERPOSABLE) |
f7d118a9 | 1496 | { |
bd3c34e9 | 1497 | funct_state y_l = funct_state_summaries->get (y); |
fc94a528 | 1498 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1499 | { | |
1500 | fprintf (dump_file, | |
1501 | " state:%s looping:%i\n", | |
1502 | pure_const_names[y_l->pure_const_state], | |
1503 | y_l->looping); | |
1504 | } | |
4c170941 | 1505 | if (y_l->pure_const_state > IPA_PURE |
35ee1c66 | 1506 | && e->cannot_lead_to_return_p ()) |
fc94a528 | 1507 | { |
1508 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
023a28e1 | 1509 | fprintf (dump_file, |
1510 | " Ignoring side effects" | |
1511 | " -> pure, looping\n"); | |
fc94a528 | 1512 | edge_state = IPA_PURE; |
1513 | edge_looping = true; | |
1514 | } | |
1515 | else | |
1516 | { | |
1517 | edge_state = y_l->pure_const_state; | |
1518 | edge_looping = y_l->looping; | |
1519 | } | |
f7d118a9 | 1520 | } |
a53e7471 | 1521 | else if (special_builtin_state (&edge_state, &edge_looping, |
02774f2d | 1522 | y->decl)) |
7dd42908 | 1523 | ; |
ef378c27 | 1524 | else |
023a28e1 | 1525 | state_from_flags (&edge_state, &edge_looping, |
02774f2d | 1526 | flags_from_decl_or_type (y->decl), |
35ee1c66 | 1527 | e->cannot_lead_to_return_p ()); |
023a28e1 | 1528 | |
1529 | /* Merge the results with what we already know. */ | |
1530 | better_state (&edge_state, &edge_looping, | |
1531 | w_l->state_previously_known, | |
1532 | w_l->looping_previously_known); | |
1533 | worse_state (&pure_const_state, &looping, | |
8b4ee73c | 1534 | edge_state, edge_looping, e->caller, e->callee); |
023a28e1 | 1535 | if (pure_const_state == IPA_NEITHER) |
1536 | break; | |
1537 | } | |
ef378c27 | 1538 | |
023a28e1 | 1539 | /* Now process the indirect call. */ |
d2c6c2b4 | 1540 | for (ie = w->indirect_calls; |
1541 | ie && pure_const_state != IPA_NEITHER; ie = ie->next_callee) | |
023a28e1 | 1542 | { |
1543 | enum pure_const_state_e edge_state = IPA_CONST; | |
1544 | bool edge_looping = false; | |
4c170941 | 1545 | |
023a28e1 | 1546 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1547 | fprintf (dump_file, " Indirect call"); | |
1548 | state_from_flags (&edge_state, &edge_looping, | |
1549 | ie->indirect_info->ecf_flags, | |
35ee1c66 | 1550 | ie->cannot_lead_to_return_p ()); |
023a28e1 | 1551 | /* Merge the results with what we already know. */ |
1552 | better_state (&edge_state, &edge_looping, | |
1553 | w_l->state_previously_known, | |
1554 | w_l->looping_previously_known); | |
1555 | worse_state (&pure_const_state, &looping, | |
8b4ee73c | 1556 | edge_state, edge_looping, NULL, NULL); |
fc94a528 | 1557 | if (pure_const_state == IPA_NEITHER) |
1558 | break; | |
f7d118a9 | 1559 | } |
023a28e1 | 1560 | |
1561 | /* And finally all loads and stores. */ | |
d2c6c2b4 | 1562 | for (i = 0; w->iterate_reference (i, ref) |
1563 | && pure_const_state != IPA_NEITHER; i++) | |
023a28e1 | 1564 | { |
1565 | enum pure_const_state_e ref_state = IPA_CONST; | |
1566 | bool ref_looping = false; | |
1567 | switch (ref->use) | |
1568 | { | |
1569 | case IPA_REF_LOAD: | |
1570 | /* readonly reads are safe. */ | |
51ce5652 | 1571 | if (TREE_READONLY (ref->referred->decl)) |
023a28e1 | 1572 | break; |
1573 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1574 | fprintf (dump_file, " nonreadonly global var read\n"); | |
1575 | ref_state = IPA_PURE; | |
1576 | break; | |
1577 | case IPA_REF_STORE: | |
51ce5652 | 1578 | if (ref->cannot_lead_to_return ()) |
023a28e1 | 1579 | break; |
1580 | ref_state = IPA_NEITHER; | |
1581 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1582 | fprintf (dump_file, " global var write\n"); | |
1583 | break; | |
1584 | case IPA_REF_ADDR: | |
1585 | break; | |
5cb7c8cf | 1586 | default: |
1587 | gcc_unreachable (); | |
023a28e1 | 1588 | } |
1589 | better_state (&ref_state, &ref_looping, | |
1590 | w_l->state_previously_known, | |
1591 | w_l->looping_previously_known); | |
1592 | worse_state (&pure_const_state, &looping, | |
8b4ee73c | 1593 | ref_state, ref_looping, NULL, NULL); |
023a28e1 | 1594 | if (pure_const_state == IPA_NEITHER) |
1595 | break; | |
1596 | } | |
02774f2d | 1597 | w_info = (struct ipa_dfs_info *) w->aux; |
f7d118a9 | 1598 | w = w_info->next_cycle; |
1599 | } | |
fc94a528 | 1600 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1601 | fprintf (dump_file, "Result %s looping %i\n", | |
1602 | pure_const_names [pure_const_state], | |
1603 | looping); | |
f7d118a9 | 1604 | |
04c849b3 | 1605 | /* Find the worst state of can_free for any node in the cycle. */ |
1606 | bool can_free = false; | |
1607 | w = node; | |
1608 | while (w && !can_free) | |
1609 | { | |
1610 | struct cgraph_edge *e; | |
bd3c34e9 | 1611 | funct_state w_l = funct_state_summaries->get (w); |
04c849b3 | 1612 | |
1613 | if (w_l->can_free | |
1614 | || w->get_availability () == AVAIL_INTERPOSABLE | |
1615 | || w->indirect_calls) | |
1616 | can_free = true; | |
1617 | ||
1618 | for (e = w->callees; e && !can_free; e = e->next_callee) | |
1619 | { | |
1620 | enum availability avail; | |
cfd85d03 | 1621 | struct cgraph_node *y = e->callee-> |
8b4ee73c | 1622 | function_or_virtual_thunk_symbol (&avail, |
1623 | e->caller); | |
04c849b3 | 1624 | |
1625 | if (avail > AVAIL_INTERPOSABLE) | |
bd3c34e9 | 1626 | can_free = funct_state_summaries->get (y)->can_free; |
04c849b3 | 1627 | else |
1628 | can_free = true; | |
1629 | } | |
1630 | w_info = (struct ipa_dfs_info *) w->aux; | |
1631 | w = w_info->next_cycle; | |
1632 | } | |
1633 | ||
f7d118a9 | 1634 | /* Copy back the region's pure_const_state which is shared by |
1635 | all nodes in the region. */ | |
1636 | w = node; | |
1637 | while (w) | |
1638 | { | |
bd3c34e9 | 1639 | funct_state w_l = funct_state_summaries->get (w); |
b5cebd44 | 1640 | enum pure_const_state_e this_state = pure_const_state; |
1641 | bool this_looping = looping; | |
f7d118a9 | 1642 | |
04c849b3 | 1643 | w_l->can_free = can_free; |
1644 | w->nonfreeing_fn = !can_free; | |
1645 | if (!can_free && dump_file) | |
1646 | fprintf (dump_file, "Function found not to call free: %s\n", | |
1647 | w->name ()); | |
1648 | ||
df9b545b | 1649 | if (w_l->state_previously_known != IPA_NEITHER |
1650 | && this_state > w_l->state_previously_known) | |
4c170941 | 1651 | { |
1652 | this_state = w_l->state_previously_known; | |
d2c6c2b4 | 1653 | if (this_state == IPA_NEITHER) |
1654 | this_looping = w_l->looping_previously_known; | |
4c170941 | 1655 | } |
a1e88032 | 1656 | if (!this_looping && self_recursive_p (w)) |
1657 | this_looping = true; | |
df9b545b | 1658 | if (!w_l->looping_previously_known) |
1659 | this_looping = false; | |
cb886925 | 1660 | |
b5cebd44 | 1661 | /* All nodes within a cycle share the same info. */ |
1662 | w_l->pure_const_state = this_state; | |
1663 | w_l->looping = this_looping; | |
1664 | ||
ce2d198d | 1665 | /* Inline clones share declaration with their offline copies; |
1666 | do not modify their declarations since the offline copy may | |
1667 | be different. */ | |
1668 | if (!w->global.inlined_to) | |
1669 | switch (this_state) | |
1670 | { | |
1671 | case IPA_CONST: | |
1672 | if (!TREE_READONLY (w->decl)) | |
1673 | { | |
1674 | warn_function_const (w->decl, !this_looping); | |
1675 | if (dump_file) | |
1676 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
1677 | this_looping ? "looping " : "", | |
1678 | w->name ()); | |
1679 | } | |
aaa36a78 | 1680 | /* Turning constructor or destructor to non-looping const/pure |
1681 | enables us to possibly remove the function completely. */ | |
1682 | if (this_looping) | |
1683 | has_cdtor = false; | |
1684 | else | |
1685 | has_cdtor = w->call_for_symbol_and_aliases (cdtor_p, | |
1686 | NULL, true); | |
1687 | if (w->set_const_flag (true, this_looping)) | |
1688 | { | |
1689 | if (dump_file) | |
1690 | fprintf (dump_file, | |
1691 | "Declaration updated to be %sconst: %s\n", | |
1692 | this_looping ? "looping " : "", | |
1693 | w->name ()); | |
1694 | remove_p |= has_cdtor; | |
1695 | } | |
ce2d198d | 1696 | break; |
48e1416a | 1697 | |
ce2d198d | 1698 | case IPA_PURE: |
1699 | if (!DECL_PURE_P (w->decl)) | |
1700 | { | |
1701 | warn_function_pure (w->decl, !this_looping); | |
1702 | if (dump_file) | |
1703 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
1704 | this_looping ? "looping " : "", | |
1705 | w->name ()); | |
1706 | } | |
aaa36a78 | 1707 | if (this_looping) |
1708 | has_cdtor = false; | |
1709 | else | |
1710 | has_cdtor = w->call_for_symbol_and_aliases (cdtor_p, | |
1711 | NULL, true); | |
1712 | if (w->set_pure_flag (true, this_looping)) | |
1713 | { | |
1714 | if (dump_file) | |
1715 | fprintf (dump_file, | |
1716 | "Declaration updated to be %spure: %s\n", | |
1717 | this_looping ? "looping " : "", | |
1718 | w->name ()); | |
1719 | remove_p |= has_cdtor; | |
1720 | } | |
ce2d198d | 1721 | break; |
48e1416a | 1722 | |
ce2d198d | 1723 | default: |
1724 | break; | |
1725 | } | |
02774f2d | 1726 | w_info = (struct ipa_dfs_info *) w->aux; |
17b28e52 | 1727 | w = w_info->next_cycle; |
1728 | } | |
1729 | } | |
1730 | ||
7771d558 | 1731 | ipa_free_postorder_info (); |
c0240443 | 1732 | free (order); |
366970c6 | 1733 | return remove_p; |
c0240443 | 1734 | } |
1735 | ||
1736 | /* Produce transitive closure over the callgraph and compute nothrow | |
1737 | attributes. */ | |
1738 | ||
1739 | static void | |
1740 | propagate_nothrow (void) | |
1741 | { | |
1742 | struct cgraph_node *node; | |
1743 | struct cgraph_node *w; | |
1744 | struct cgraph_node **order = | |
35ee1c66 | 1745 | XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); |
c0240443 | 1746 | int order_pos; |
1747 | int i; | |
1748 | struct ipa_dfs_info * w_info; | |
1749 | ||
355c1f40 | 1750 | order_pos = ipa_reduced_postorder (order, true, false, |
1751 | ignore_edge_for_nothrow); | |
17b28e52 | 1752 | if (dump_file) |
1753 | { | |
415d1b9a | 1754 | cgraph_node::dump_cgraph (dump_file); |
7771d558 | 1755 | ipa_print_order (dump_file, "reduced for nothrow", order, order_pos); |
17b28e52 | 1756 | } |
c0240443 | 1757 | |
9d75589a | 1758 | /* Propagate the local information through the call graph to produce |
17b28e52 | 1759 | the global information. All the nodes within a cycle will have |
1760 | the same info so we collapse cycles first. Then we can do the | |
1761 | propagation in one pass from the leaves to the roots. */ | |
1762 | for (i = 0; i < order_pos; i++ ) | |
1763 | { | |
1764 | bool can_throw = false; | |
1765 | node = order[i]; | |
1766 | ||
02774f2d | 1767 | if (node->alias) |
8c1fce46 | 1768 | continue; |
1769 | ||
17b28e52 | 1770 | /* Find the worst state for any node in the cycle. */ |
1771 | w = node; | |
b2c90c54 | 1772 | while (w && !can_throw) |
17b28e52 | 1773 | { |
023a28e1 | 1774 | struct cgraph_edge *e, *ie; |
17b28e52 | 1775 | |
355c1f40 | 1776 | if (!TREE_NOTHROW (w->decl)) |
17b28e52 | 1777 | { |
16f72bd0 | 1778 | funct_state w_l = funct_state_summaries->get_create (w); |
17b28e52 | 1779 | |
355c1f40 | 1780 | if (w_l->can_throw |
1781 | || w->get_availability () == AVAIL_INTERPOSABLE) | |
1782 | can_throw = true; | |
1783 | ||
1784 | for (e = w->callees; e && !can_throw; e = e->next_callee) | |
17b28e52 | 1785 | { |
355c1f40 | 1786 | enum availability avail; |
1787 | ||
1788 | if (!e->can_throw_external || TREE_NOTHROW (e->callee->decl)) | |
1789 | continue; | |
1790 | ||
1791 | struct cgraph_node *y = e->callee-> | |
ace7bf06 | 1792 | function_or_virtual_thunk_symbol (&avail, |
1793 | e->caller); | |
17b28e52 | 1794 | |
355c1f40 | 1795 | /* We can use info about the callee only if we know it can |
ace7bf06 | 1796 | not be interposed. |
1797 | When callee is compiled with non-call exceptions we also | |
1798 | must check that the declaration is bound to current | |
1799 | body as other semantically equivalent body may still | |
1800 | throw. */ | |
355c1f40 | 1801 | if (avail <= AVAIL_INTERPOSABLE |
1802 | || (!TREE_NOTHROW (y->decl) | |
16f72bd0 | 1803 | && (funct_state_summaries->get_create (y)->can_throw |
ace7bf06 | 1804 | || (opt_for_fn (y->decl, flag_non_call_exceptions) |
1805 | && !e->callee->binds_to_current_def_p (w))))) | |
17b28e52 | 1806 | can_throw = true; |
1807 | } | |
355c1f40 | 1808 | for (ie = w->indirect_calls; ie && !can_throw; |
1809 | ie = ie->next_callee) | |
1810 | if (ie->can_throw_external | |
1811 | && !(ie->indirect_info->ecf_flags & ECF_NOTHROW)) | |
1812 | can_throw = true; | |
17b28e52 | 1813 | } |
02774f2d | 1814 | w_info = (struct ipa_dfs_info *) w->aux; |
17b28e52 | 1815 | w = w_info->next_cycle; |
1816 | } | |
1817 | ||
1818 | /* Copy back the region's pure_const_state which is shared by | |
1819 | all nodes in the region. */ | |
1820 | w = node; | |
1821 | while (w) | |
1822 | { | |
eb57efa5 | 1823 | funct_state w_l = funct_state_summaries->get_create (w); |
02774f2d | 1824 | if (!can_throw && !TREE_NOTHROW (w->decl)) |
b5cebd44 | 1825 | { |
ce2d198d | 1826 | /* Inline clones share declaration with their offline copies; |
1827 | do not modify their declarations since the offline copy may | |
1828 | be different. */ | |
1829 | if (!w->global.inlined_to) | |
1830 | { | |
415d1b9a | 1831 | w->set_nothrow_flag (true); |
ce2d198d | 1832 | if (dump_file) |
1833 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
1834 | w->name ()); | |
1835 | } | |
f7d118a9 | 1836 | } |
02774f2d | 1837 | else if (can_throw && !TREE_NOTHROW (w->decl)) |
ecfab407 | 1838 | w_l->can_throw = true; |
02774f2d | 1839 | w_info = (struct ipa_dfs_info *) w->aux; |
f7d118a9 | 1840 | w = w_info->next_cycle; |
1841 | } | |
1842 | } | |
1843 | ||
7771d558 | 1844 | ipa_free_postorder_info (); |
f7d118a9 | 1845 | free (order); |
c0240443 | 1846 | } |
1847 | ||
bd5ef087 | 1848 | /* Debugging function to dump state of malloc lattice. */ |
1849 | ||
1850 | DEBUG_FUNCTION | |
1851 | static void | |
1852 | dump_malloc_lattice (FILE *dump_file, const char *s) | |
1853 | { | |
1854 | if (!dump_file) | |
1855 | return; | |
1856 | ||
1857 | fprintf (dump_file, "\n\nMALLOC LATTICE %s:\n", s); | |
1858 | cgraph_node *node; | |
1859 | FOR_EACH_FUNCTION (node) | |
1860 | { | |
2c085ec2 | 1861 | funct_state fs = funct_state_summaries->get (node); |
1862 | if (fs) | |
1863 | fprintf (dump_file, "%s: %s\n", node->name (), | |
1864 | malloc_state_names[fs->malloc_state]); | |
bd5ef087 | 1865 | } |
1866 | } | |
1867 | ||
1868 | /* Propagate malloc attribute across the callgraph. */ | |
1869 | ||
1870 | static void | |
1871 | propagate_malloc (void) | |
1872 | { | |
1873 | cgraph_node *node; | |
1874 | FOR_EACH_FUNCTION (node) | |
1875 | { | |
1876 | if (DECL_IS_MALLOC (node->decl)) | |
16f72bd0 | 1877 | if (!funct_state_summaries->exists (node)) |
bd5ef087 | 1878 | { |
16f72bd0 | 1879 | funct_state fs = funct_state_summaries->get_create (node); |
1880 | fs->malloc_state = STATE_MALLOC; | |
bd5ef087 | 1881 | } |
1882 | } | |
1883 | ||
1884 | dump_malloc_lattice (dump_file, "Initial"); | |
1885 | struct cgraph_node **order | |
1886 | = XNEWVEC (struct cgraph_node *, symtab->cgraph_count); | |
1887 | int order_pos = ipa_reverse_postorder (order); | |
1888 | bool changed = true; | |
1889 | ||
1890 | while (changed) | |
1891 | { | |
1892 | changed = false; | |
1893 | /* Walk in postorder. */ | |
1894 | for (int i = order_pos - 1; i >= 0; --i) | |
1895 | { | |
1896 | cgraph_node *node = order[i]; | |
1897 | if (node->alias | |
1898 | || !node->definition | |
16f72bd0 | 1899 | || !funct_state_summaries->exists (node)) |
bd5ef087 | 1900 | continue; |
1901 | ||
2c085ec2 | 1902 | funct_state l = funct_state_summaries->get (node); |
bd5ef087 | 1903 | |
1904 | /* FIXME: add support for indirect-calls. */ | |
1905 | if (node->indirect_calls) | |
1906 | { | |
1907 | l->malloc_state = STATE_MALLOC_BOTTOM; | |
1908 | continue; | |
1909 | } | |
1910 | ||
1911 | if (node->get_availability () <= AVAIL_INTERPOSABLE) | |
1912 | { | |
1913 | l->malloc_state = STATE_MALLOC_BOTTOM; | |
1914 | continue; | |
1915 | } | |
1916 | ||
1917 | if (l->malloc_state == STATE_MALLOC_BOTTOM) | |
1918 | continue; | |
1919 | ||
1920 | vec<cgraph_node *> callees = vNULL; | |
1921 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) | |
1922 | { | |
b53d4f56 | 1923 | ipa_call_summary *es = ipa_call_summaries->get_create (cs); |
bd5ef087 | 1924 | if (es && es->is_return_callee_uncaptured) |
1925 | callees.safe_push (cs->callee); | |
1926 | } | |
1927 | ||
1928 | malloc_state_e new_state = l->malloc_state; | |
1929 | for (unsigned j = 0; j < callees.length (); j++) | |
1930 | { | |
1931 | cgraph_node *callee = callees[j]; | |
16f72bd0 | 1932 | if (!funct_state_summaries->exists (node)) |
bd5ef087 | 1933 | { |
1934 | new_state = STATE_MALLOC_BOTTOM; | |
1935 | break; | |
1936 | } | |
16f72bd0 | 1937 | malloc_state_e callee_state |
1938 | = funct_state_summaries->get_create (callee)->malloc_state; | |
bd5ef087 | 1939 | if (new_state < callee_state) |
1940 | new_state = callee_state; | |
1941 | } | |
1942 | if (new_state != l->malloc_state) | |
1943 | { | |
1944 | changed = true; | |
1945 | l->malloc_state = new_state; | |
1946 | } | |
1947 | } | |
1948 | } | |
1949 | ||
1950 | FOR_EACH_DEFINED_FUNCTION (node) | |
16f72bd0 | 1951 | if (funct_state_summaries->exists (node)) |
bd5ef087 | 1952 | { |
2c085ec2 | 1953 | funct_state l = funct_state_summaries->get (node); |
bd5ef087 | 1954 | if (!node->alias |
1955 | && l->malloc_state == STATE_MALLOC | |
1956 | && !node->global.inlined_to) | |
1957 | { | |
1958 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1959 | fprintf (dump_file, "Function %s found to be malloc\n", | |
1960 | node->name ()); | |
1961 | ||
1962 | bool malloc_decl_p = DECL_IS_MALLOC (node->decl); | |
1963 | node->set_malloc_flag (true); | |
1964 | if (!malloc_decl_p && warn_suggest_attribute_malloc) | |
1965 | warn_function_malloc (node->decl); | |
1966 | } | |
1967 | } | |
1968 | ||
1969 | dump_malloc_lattice (dump_file, "after propagation"); | |
1970 | ipa_free_postorder_info (); | |
1971 | free (order); | |
1972 | } | |
c0240443 | 1973 | |
1974 | /* Produce the global information by preforming a transitive closure | |
1975 | on the local information that was produced by generate_summary. */ | |
1976 | ||
415309e2 | 1977 | unsigned int |
1978 | pass_ipa_pure_const:: | |
1979 | execute (function *) | |
c0240443 | 1980 | { |
366970c6 | 1981 | bool remove_p; |
c0240443 | 1982 | |
c0240443 | 1983 | /* Nothrow makes more function to not lead to return and improve |
1984 | later analysis. */ | |
1985 | propagate_nothrow (); | |
bd5ef087 | 1986 | propagate_malloc (); |
366970c6 | 1987 | remove_p = propagate_pure_const (); |
c0240443 | 1988 | |
16f72bd0 | 1989 | delete funct_state_summaries; |
366970c6 | 1990 | return remove_p ? TODO_remove_functions : 0; |
f7d118a9 | 1991 | } |
1992 | ||
1993 | static bool | |
1994 | gate_pure_const (void) | |
1995 | { | |
d1f68cd8 | 1996 | return flag_ipa_pure_const || in_lto_p; |
f7d118a9 | 1997 | } |
1998 | ||
415309e2 | 1999 | pass_ipa_pure_const::pass_ipa_pure_const(gcc::context *ctxt) |
2000 | : ipa_opt_pass_d(pass_data_ipa_pure_const, ctxt, | |
2001 | pure_const_generate_summary, /* generate_summary */ | |
2002 | pure_const_write_summary, /* write_summary */ | |
2003 | pure_const_read_summary, /* read_summary */ | |
2004 | NULL, /* write_optimization_summary */ | |
2005 | NULL, /* read_optimization_summary */ | |
2006 | NULL, /* stmt_fixup */ | |
2007 | 0, /* function_transform_todo_flags_start */ | |
2008 | NULL, /* function_transform */ | |
2009 | NULL), /* variable_transform */ | |
16f72bd0 | 2010 | init_p (false) {} |
cbe8bda8 | 2011 | |
2012 | ipa_opt_pass_d * | |
2013 | make_pass_ipa_pure_const (gcc::context *ctxt) | |
2014 | { | |
2015 | return new pass_ipa_pure_const (ctxt); | |
2016 | } | |
2017 | ||
2c06958d | 2018 | /* Return true if function should be skipped for local pure const analysis. */ |
b5cebd44 | 2019 | |
2c06958d | 2020 | static bool |
2021 | skip_function_for_local_pure_const (struct cgraph_node *node) | |
b5cebd44 | 2022 | { |
8b4ee73c | 2023 | /* Because we do not schedule pass_fixup_cfg over whole program after early |
2024 | optimizations we must not promote functions that are called by already | |
2025 | processed functions. */ | |
b5cebd44 | 2026 | |
2027 | if (function_called_by_processed_nodes_p ()) | |
2028 | { | |
2029 | if (dump_file) | |
2030 | fprintf (dump_file, "Function called in recursive cycle; ignoring\n"); | |
2c06958d | 2031 | return true; |
b5cebd44 | 2032 | } |
aaa36a78 | 2033 | /* Save some work and do not analyze functions which are interposable and |
2034 | do not have any non-interposable aliases. */ | |
2035 | if (node->get_availability () <= AVAIL_INTERPOSABLE | |
2036 | && !node->has_aliases_p ()) | |
b5cebd44 | 2037 | { |
2038 | if (dump_file) | |
8b4ee73c | 2039 | fprintf (dump_file, |
aaa36a78 | 2040 | "Function is interposable; not analyzing.\n"); |
2c06958d | 2041 | return true; |
b5cebd44 | 2042 | } |
2c06958d | 2043 | return false; |
2044 | } | |
2045 | ||
2046 | /* Simple local pass for pure const discovery reusing the analysis from | |
2047 | ipa_pure_const. This pass is effective when executed together with | |
2048 | other optimization passes in early optimization pass queue. */ | |
b5cebd44 | 2049 | |
7620bc82 | 2050 | namespace { |
2051 | ||
2052 | const pass_data pass_data_local_pure_const = | |
65b0537f | 2053 | { |
2054 | GIMPLE_PASS, /* type */ | |
2055 | "local-pure-const", /* name */ | |
2056 | OPTGROUP_NONE, /* optinfo_flags */ | |
65b0537f | 2057 | TV_IPA_PURE_CONST, /* tv_id */ |
2058 | 0, /* properties_required */ | |
2059 | 0, /* properties_provided */ | |
2060 | 0, /* properties_destroyed */ | |
2061 | 0, /* todo_flags_start */ | |
2062 | 0, /* todo_flags_finish */ | |
2063 | }; | |
2064 | ||
7620bc82 | 2065 | class pass_local_pure_const : public gimple_opt_pass |
65b0537f | 2066 | { |
2067 | public: | |
2068 | pass_local_pure_const (gcc::context *ctxt) | |
2069 | : gimple_opt_pass (pass_data_local_pure_const, ctxt) | |
2070 | {} | |
2071 | ||
2072 | /* opt_pass methods: */ | |
2073 | opt_pass * clone () { return new pass_local_pure_const (m_ctxt); } | |
2074 | virtual bool gate (function *) { return gate_pure_const (); } | |
2075 | virtual unsigned int execute (function *); | |
2076 | ||
2077 | }; // class pass_local_pure_const | |
2078 | ||
2079 | unsigned int | |
2080 | pass_local_pure_const::execute (function *fun) | |
2c06958d | 2081 | { |
2082 | bool changed = false; | |
2083 | funct_state l; | |
2084 | bool skip; | |
2085 | struct cgraph_node *node; | |
2086 | ||
415d1b9a | 2087 | node = cgraph_node::get (current_function_decl); |
2c06958d | 2088 | skip = skip_function_for_local_pure_const (node); |
60722a03 | 2089 | |
2c06958d | 2090 | if (!warn_suggest_attribute_const |
2091 | && !warn_suggest_attribute_pure | |
2092 | && skip) | |
2093 | return 0; | |
e0933141 | 2094 | |
ab3db708 | 2095 | l = analyze_function (node, false); |
2096 | ||
2097 | /* Do NORETURN discovery. */ | |
e0933141 | 2098 | if (!skip && !TREE_THIS_VOLATILE (current_function_decl) |
65b0537f | 2099 | && EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (fun)->preds) == 0) |
e0933141 | 2100 | { |
65b0537f | 2101 | warn_function_noreturn (fun->decl); |
e0933141 | 2102 | if (dump_file) |
65b0537f | 2103 | fprintf (dump_file, "Function found to be noreturn: %s\n", |
2104 | current_function_name ()); | |
e0933141 | 2105 | |
2106 | /* Update declaration and reduce profile to executed once. */ | |
2107 | TREE_THIS_VOLATILE (current_function_decl) = 1; | |
2108 | if (node->frequency > NODE_FREQUENCY_EXECUTED_ONCE) | |
65b0537f | 2109 | node->frequency = NODE_FREQUENCY_EXECUTED_ONCE; |
e0933141 | 2110 | |
2111 | changed = true; | |
2112 | } | |
ef378c27 | 2113 | |
b5cebd44 | 2114 | switch (l->pure_const_state) |
2115 | { | |
2116 | case IPA_CONST: | |
2117 | if (!TREE_READONLY (current_function_decl)) | |
2118 | { | |
2c06958d | 2119 | warn_function_const (current_function_decl, !l->looping); |
b5cebd44 | 2120 | if (dump_file) |
2121 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
2122 | l->looping ? "looping " : "", | |
9631926a | 2123 | current_function_name ()); |
b5cebd44 | 2124 | } |
2125 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
2126 | && !l->looping) | |
2127 | { | |
b5cebd44 | 2128 | if (dump_file) |
2129 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 2130 | current_function_name ()); |
b5cebd44 | 2131 | } |
aaa36a78 | 2132 | if (!skip && node->set_const_flag (true, l->looping)) |
2133 | { | |
2134 | if (dump_file) | |
2135 | fprintf (dump_file, "Declaration updated to be %sconst: %s\n", | |
2136 | l->looping ? "looping " : "", | |
2137 | current_function_name ()); | |
2138 | changed = true; | |
2139 | } | |
b5cebd44 | 2140 | break; |
2141 | ||
2142 | case IPA_PURE: | |
2c06958d | 2143 | if (!DECL_PURE_P (current_function_decl)) |
b5cebd44 | 2144 | { |
2c06958d | 2145 | warn_function_pure (current_function_decl, !l->looping); |
b5cebd44 | 2146 | if (dump_file) |
2147 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
2148 | l->looping ? "looping " : "", | |
9631926a | 2149 | current_function_name ()); |
b5cebd44 | 2150 | } |
2151 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
2152 | && !l->looping) | |
2153 | { | |
b5cebd44 | 2154 | if (dump_file) |
2155 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 2156 | current_function_name ()); |
b5cebd44 | 2157 | } |
aaa36a78 | 2158 | if (!skip && node->set_pure_flag (true, l->looping)) |
2159 | { | |
2160 | if (dump_file) | |
2161 | fprintf (dump_file, "Declaration updated to be %spure: %s\n", | |
2162 | l->looping ? "looping " : "", | |
2163 | current_function_name ()); | |
2164 | changed = true; | |
2165 | } | |
b5cebd44 | 2166 | break; |
2167 | ||
2168 | default: | |
2169 | break; | |
2170 | } | |
2171 | if (!l->can_throw && !TREE_NOTHROW (current_function_decl)) | |
2172 | { | |
415d1b9a | 2173 | node->set_nothrow_flag (true); |
b5cebd44 | 2174 | changed = true; |
2175 | if (dump_file) | |
2176 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
9631926a | 2177 | current_function_name ()); |
b5cebd44 | 2178 | } |
bd5ef087 | 2179 | |
2180 | if (l->malloc_state == STATE_MALLOC | |
2181 | && !DECL_IS_MALLOC (current_function_decl)) | |
2182 | { | |
2183 | node->set_malloc_flag (true); | |
2184 | if (warn_suggest_attribute_malloc) | |
2185 | warn_function_malloc (node->decl); | |
2186 | changed = true; | |
2187 | if (dump_file) | |
2188 | fprintf (dump_file, "Function found to be malloc: %s\n", | |
2189 | node->name ()); | |
2190 | } | |
2191 | ||
dd045aee | 2192 | free (l); |
b5cebd44 | 2193 | if (changed) |
2194 | return execute_fixup_cfg (); | |
2195 | else | |
2196 | return 0; | |
2197 | } | |
2198 | ||
7620bc82 | 2199 | } // anon namespace |
2200 | ||
cbe8bda8 | 2201 | gimple_opt_pass * |
2202 | make_pass_local_pure_const (gcc::context *ctxt) | |
2203 | { | |
2204 | return new pass_local_pure_const (ctxt); | |
2205 | } | |
64641360 | 2206 | |
2207 | /* Emit noreturn warnings. */ | |
2208 | ||
7620bc82 | 2209 | namespace { |
2210 | ||
2211 | const pass_data pass_data_warn_function_noreturn = | |
64641360 | 2212 | { |
2213 | GIMPLE_PASS, /* type */ | |
2214 | "*warn_function_noreturn", /* name */ | |
2215 | OPTGROUP_NONE, /* optinfo_flags */ | |
64641360 | 2216 | TV_NONE, /* tv_id */ |
2217 | PROP_cfg, /* properties_required */ | |
2218 | 0, /* properties_provided */ | |
2219 | 0, /* properties_destroyed */ | |
2220 | 0, /* todo_flags_start */ | |
2221 | 0, /* todo_flags_finish */ | |
2222 | }; | |
2223 | ||
7620bc82 | 2224 | class pass_warn_function_noreturn : public gimple_opt_pass |
64641360 | 2225 | { |
2226 | public: | |
2227 | pass_warn_function_noreturn (gcc::context *ctxt) | |
2228 | : gimple_opt_pass (pass_data_warn_function_noreturn, ctxt) | |
2229 | {} | |
2230 | ||
2231 | /* opt_pass methods: */ | |
31315c24 | 2232 | virtual bool gate (function *) { return warn_suggest_attribute_noreturn; } |
65b0537f | 2233 | virtual unsigned int execute (function *fun) |
2234 | { | |
2235 | if (!TREE_THIS_VOLATILE (current_function_decl) | |
2236 | && EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (fun)->preds) == 0) | |
2237 | warn_function_noreturn (current_function_decl); | |
2238 | return 0; | |
2239 | } | |
64641360 | 2240 | |
2241 | }; // class pass_warn_function_noreturn | |
2242 | ||
7620bc82 | 2243 | } // anon namespace |
2244 | ||
64641360 | 2245 | gimple_opt_pass * |
2246 | make_pass_warn_function_noreturn (gcc::context *ctxt) | |
2247 | { | |
2248 | return new pass_warn_function_noreturn (ctxt); | |
2249 | } | |
73594827 | 2250 | |
2251 | /* Simple local pass for pure const discovery reusing the analysis from | |
2252 | ipa_pure_const. This pass is effective when executed together with | |
2253 | other optimization passes in early optimization pass queue. */ | |
2254 | ||
7620bc82 | 2255 | namespace { |
2256 | ||
2257 | const pass_data pass_data_nothrow = | |
73594827 | 2258 | { |
2259 | GIMPLE_PASS, /* type */ | |
2260 | "nothrow", /* name */ | |
2261 | OPTGROUP_NONE, /* optinfo_flags */ | |
2262 | TV_IPA_PURE_CONST, /* tv_id */ | |
2263 | 0, /* properties_required */ | |
2264 | 0, /* properties_provided */ | |
2265 | 0, /* properties_destroyed */ | |
2266 | 0, /* todo_flags_start */ | |
2267 | 0, /* todo_flags_finish */ | |
2268 | }; | |
2269 | ||
7620bc82 | 2270 | class pass_nothrow : public gimple_opt_pass |
73594827 | 2271 | { |
2272 | public: | |
2273 | pass_nothrow (gcc::context *ctxt) | |
2274 | : gimple_opt_pass (pass_data_nothrow, ctxt) | |
2275 | {} | |
2276 | ||
2277 | /* opt_pass methods: */ | |
2278 | opt_pass * clone () { return new pass_nothrow (m_ctxt); } | |
2279 | virtual bool gate (function *) { return optimize; } | |
2280 | virtual unsigned int execute (function *); | |
2281 | ||
2282 | }; // class pass_nothrow | |
2283 | ||
2284 | unsigned int | |
2285 | pass_nothrow::execute (function *) | |
2286 | { | |
2287 | struct cgraph_node *node; | |
2288 | basic_block this_block; | |
2289 | ||
2290 | if (TREE_NOTHROW (current_function_decl)) | |
2291 | return 0; | |
2292 | ||
2293 | node = cgraph_node::get (current_function_decl); | |
2294 | ||
2295 | /* We run during lowering, we can not really use availability yet. */ | |
2296 | if (cgraph_node::get (current_function_decl)->get_availability () | |
2297 | <= AVAIL_INTERPOSABLE) | |
2298 | { | |
2299 | if (dump_file) | |
2300 | fprintf (dump_file, "Function is interposable;" | |
2301 | " not analyzing.\n"); | |
2302 | return true; | |
2303 | } | |
2304 | ||
2305 | FOR_EACH_BB_FN (this_block, cfun) | |
2306 | { | |
2307 | for (gimple_stmt_iterator gsi = gsi_start_bb (this_block); | |
2308 | !gsi_end_p (gsi); | |
2309 | gsi_next (&gsi)) | |
aac19106 | 2310 | if (stmt_can_throw_external (cfun, gsi_stmt (gsi))) |
73594827 | 2311 | { |
2312 | if (is_gimple_call (gsi_stmt (gsi))) | |
2313 | { | |
2314 | tree callee_t = gimple_call_fndecl (gsi_stmt (gsi)); | |
2315 | if (callee_t && recursive_call_p (current_function_decl, | |
2316 | callee_t)) | |
2317 | continue; | |
2318 | } | |
2319 | ||
2320 | if (dump_file) | |
2321 | { | |
2322 | fprintf (dump_file, "Statement can throw: "); | |
1ffa4346 | 2323 | print_gimple_stmt (dump_file, gsi_stmt (gsi), 0); |
73594827 | 2324 | } |
2325 | return 0; | |
2326 | } | |
2327 | } | |
2328 | ||
2329 | node->set_nothrow_flag (true); | |
fd499010 | 2330 | |
2331 | bool cfg_changed = false; | |
2332 | if (self_recursive_p (node)) | |
2333 | FOR_EACH_BB_FN (this_block, cfun) | |
2334 | if (gimple *g = last_stmt (this_block)) | |
2335 | if (is_gimple_call (g)) | |
2336 | { | |
2337 | tree callee_t = gimple_call_fndecl (g); | |
2338 | if (callee_t | |
2339 | && recursive_call_p (current_function_decl, callee_t) | |
2340 | && maybe_clean_eh_stmt (g) | |
2341 | && gimple_purge_dead_eh_edges (this_block)) | |
2342 | cfg_changed = true; | |
2343 | } | |
2344 | ||
73594827 | 2345 | if (dump_file) |
2346 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
2347 | current_function_name ()); | |
fd499010 | 2348 | return cfg_changed ? TODO_cleanup_cfg : 0; |
73594827 | 2349 | } |
2350 | ||
7620bc82 | 2351 | } // anon namespace |
2352 | ||
73594827 | 2353 | gimple_opt_pass * |
2354 | make_pass_nothrow (gcc::context *ctxt) | |
2355 | { | |
2356 | return new pass_nothrow (ctxt); | |
2357 | } |