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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 | ||
2e966e2a | 125 | typedef class funct_state_d * funct_state; |
f7d118a9 | 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 | |
1add72d5 | 131 | class funct_state_summary_t: |
132 | public fast_function_summary <funct_state_d *, va_heap> | |
16f72bd0 | 133 | { |
134 | public: | |
135 | funct_state_summary_t (symbol_table *symtab): | |
1add72d5 | 136 | fast_function_summary <funct_state_d *, va_heap> (symtab) {} |
16f72bd0 | 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 | }; | |
cb886925 | 143 | |
16f72bd0 | 144 | static funct_state_summary_t *funct_state_summaries = NULL; |
cb886925 | 145 | |
415309e2 | 146 | static bool gate_pure_const (void); |
147 | ||
7620bc82 | 148 | namespace { |
149 | ||
150 | const pass_data pass_data_ipa_pure_const = | |
415309e2 | 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 | ||
7620bc82 | 163 | class pass_ipa_pure_const : public ipa_opt_pass_d |
415309e2 | 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; | |
415309e2 | 176 | }; // class pass_ipa_pure_const |
177 | ||
7620bc82 | 178 | } // anon namespace |
179 | ||
2c06958d | 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 | { | |
60722a03 | 187 | return (!TREE_PUBLIC (decl) || DECL_DECLARED_INLINE_P (decl) |
188 | || DECL_COMDAT (decl)); | |
2c06958d | 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 | |
431205b7 | 193 | controlled by OPTION. WARNED_ABOUT is a hash_set<tree> unique for |
2c06958d | 194 | OPTION, this function may initialize it and it is always returned |
195 | by the function. */ | |
196 | ||
431205b7 | 197 | static hash_set<tree> * |
2c06958d | 198 | suggest_attribute (int option, tree decl, bool known_finite, |
431205b7 | 199 | hash_set<tree> *warned_about, |
2c06958d | 200 | const char * attrib_name) |
201 | { | |
a02d8e72 | 202 | if (!option_enabled (option, lang_hooks.option_lang_mask (), &global_options)) |
2c06958d | 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) | |
431205b7 | 209 | warned_about = new hash_set<tree>; |
210 | if (warned_about->contains (decl)) | |
2c06958d | 211 | return warned_about; |
431205b7 | 212 | warned_about->add (decl); |
2c06958d | 213 | warning_at (DECL_SOURCE_LOCATION (decl), |
214 | option, | |
215 | known_finite | |
ca1f4c7a | 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); | |
2c06958d | 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 | { | |
2acafe26 | 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; | |
2c06958d | 232 | |
2acafe26 | 233 | static hash_set<tree> *warned_about; |
234 | warned_about | |
2c06958d | 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 | { | |
2acafe26 | 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 | ||
431205b7 | 250 | static hash_set<tree> *warned_about; |
2acafe26 | 251 | warned_about |
2c06958d | 252 | = suggest_attribute (OPT_Wsuggest_attribute_const, decl, |
253 | known_finite, warned_about, "const"); | |
254 | } | |
43d60d64 | 255 | |
bd5ef087 | 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, | |
9deb0d09 | 264 | true, warned_about, "malloc"); |
bd5ef087 | 265 | } |
266 | ||
267 | /* Emit suggestion about __attribute__((noreturn)) for DECL. */ | |
268 | ||
64641360 | 269 | static void |
43d60d64 | 270 | warn_function_noreturn (tree decl) |
271 | { | |
313dfc4e | 272 | tree original_decl = decl; |
273 | ||
431205b7 | 274 | static hash_set<tree> *warned_about; |
08c6cbd2 | 275 | if (!lang_hooks.missing_noreturn_ok_p (decl) |
276 | && targetm.warn_func_return (decl)) | |
43d60d64 | 277 | warned_about |
313dfc4e | 278 | = suggest_attribute (OPT_Wsuggest_attribute_noreturn, original_decl, |
43d60d64 | 279 | true, warned_about, "noreturn"); |
280 | } | |
9631926a | 281 | |
60722a03 | 282 | void |
283 | warn_function_cold (tree decl) | |
284 | { | |
285 | tree original_decl = decl; | |
286 | ||
60722a03 | 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 | ||
f0b5f617 | 293 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
f7d118a9 | 294 | variable T is legal in a function that is either pure or const. */ |
295 | ||
48e1416a | 296 | static inline void |
297 | check_decl (funct_state local, | |
023a28e1 | 298 | tree t, bool checking_write, bool ipa) |
f7d118a9 | 299 | { |
f7d118a9 | 300 | /* Do not want to do anything with volatile except mark any |
301 | function that uses one to be not const or pure. */ | |
48e1416a | 302 | if (TREE_THIS_VOLATILE (t)) |
303 | { | |
f7d118a9 | 304 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 305 | if (dump_file) |
f7d67aae | 306 | fprintf (dump_file, " Volatile operand is not const/pure\n"); |
f7d118a9 | 307 | return; |
308 | } | |
309 | ||
310 | /* Do not care about a local automatic that is not static. */ | |
311 | if (!TREE_STATIC (t) && !DECL_EXTERNAL (t)) | |
312 | return; | |
313 | ||
b5cebd44 | 314 | /* If the variable has the "used" attribute, treat it as if it had a |
315 | been touched by the devil. */ | |
83a23b05 | 316 | if (DECL_PRESERVE_P (t)) |
b5cebd44 | 317 | { |
318 | local->pure_const_state = IPA_NEITHER; | |
319 | if (dump_file) | |
320 | fprintf (dump_file, " Used static/global variable is not const/pure\n"); | |
321 | return; | |
322 | } | |
323 | ||
023a28e1 | 324 | /* In IPA mode we are not interested in checking actual loads and stores; |
325 | they will be processed at propagation time using ipa_ref. */ | |
326 | if (ipa) | |
327 | return; | |
328 | ||
f7d118a9 | 329 | /* Since we have dealt with the locals and params cases above, if we |
330 | are CHECKING_WRITE, this cannot be a pure or constant | |
331 | function. */ | |
48e1416a | 332 | if (checking_write) |
bc17fd99 | 333 | { |
334 | local->pure_const_state = IPA_NEITHER; | |
b5cebd44 | 335 | if (dump_file) |
336 | fprintf (dump_file, " static/global memory write is not const/pure\n"); | |
bc17fd99 | 337 | return; |
338 | } | |
f7d118a9 | 339 | |
340 | if (DECL_EXTERNAL (t) || TREE_PUBLIC (t)) | |
341 | { | |
b5cebd44 | 342 | /* Readonly reads are safe. */ |
7d136f71 | 343 | if (TREE_READONLY (t)) |
b5cebd44 | 344 | return; /* Read of a constant, do not change the function state. */ |
48e1416a | 345 | else |
f7d118a9 | 346 | { |
b5cebd44 | 347 | if (dump_file) |
348 | fprintf (dump_file, " global memory read is not const\n"); | |
f7d118a9 | 349 | /* Just a regular read. */ |
350 | if (local->pure_const_state == IPA_CONST) | |
351 | local->pure_const_state = IPA_PURE; | |
352 | } | |
353 | } | |
b5cebd44 | 354 | else |
355 | { | |
356 | /* Compilation level statics can be read if they are readonly | |
357 | variables. */ | |
358 | if (TREE_READONLY (t)) | |
359 | return; | |
360 | ||
361 | if (dump_file) | |
362 | fprintf (dump_file, " static memory read is not const\n"); | |
363 | /* Just a regular read. */ | |
364 | if (local->pure_const_state == IPA_CONST) | |
365 | local->pure_const_state = IPA_PURE; | |
366 | } | |
f7d118a9 | 367 | } |
368 | ||
f7d118a9 | 369 | |
b5cebd44 | 370 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
371 | variable T is legal in a function that is either pure or const. */ | |
f7d118a9 | 372 | |
48e1416a | 373 | static inline void |
5ed0b345 | 374 | check_op (funct_state local, tree t, bool checking_write) |
f7d118a9 | 375 | { |
3ae61172 | 376 | t = get_base_address (t); |
377 | if (t && TREE_THIS_VOLATILE (t)) | |
f7d118a9 | 378 | { |
5ed0b345 | 379 | local->pure_const_state = IPA_NEITHER; |
380 | if (dump_file) | |
381 | fprintf (dump_file, " Volatile indirect ref is not const/pure\n"); | |
382 | return; | |
383 | } | |
3ae61172 | 384 | else if (t |
182cf5a9 | 385 | && (INDIRECT_REF_P (t) || TREE_CODE (t) == MEM_REF) |
3ae61172 | 386 | && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME |
387 | && !ptr_deref_may_alias_global_p (TREE_OPERAND (t, 0))) | |
388 | { | |
389 | if (dump_file) | |
390 | fprintf (dump_file, " Indirect ref to local memory is OK\n"); | |
391 | return; | |
392 | } | |
5ed0b345 | 393 | else if (checking_write) |
394 | { | |
395 | local->pure_const_state = IPA_NEITHER; | |
396 | if (dump_file) | |
397 | fprintf (dump_file, " Indirect ref write is not const/pure\n"); | |
398 | return; | |
399 | } | |
400 | else | |
401 | { | |
402 | if (dump_file) | |
403 | fprintf (dump_file, " Indirect ref read is not const\n"); | |
404 | if (local->pure_const_state == IPA_CONST) | |
405 | local->pure_const_state = IPA_PURE; | |
f7d118a9 | 406 | } |
407 | } | |
408 | ||
023a28e1 | 409 | /* compute state based on ECF FLAGS and store to STATE and LOOPING. */ |
410 | ||
411 | static void | |
412 | state_from_flags (enum pure_const_state_e *state, bool *looping, | |
413 | int flags, bool cannot_lead_to_return) | |
414 | { | |
415 | *looping = false; | |
416 | if (flags & ECF_LOOPING_CONST_OR_PURE) | |
417 | { | |
418 | *looping = true; | |
419 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
f7d67aae | 420 | fprintf (dump_file, " looping\n"); |
023a28e1 | 421 | } |
422 | if (flags & ECF_CONST) | |
423 | { | |
424 | *state = IPA_CONST; | |
425 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
426 | fprintf (dump_file, " const\n"); | |
427 | } | |
428 | else if (flags & ECF_PURE) | |
429 | { | |
430 | *state = IPA_PURE; | |
431 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
432 | fprintf (dump_file, " pure\n"); | |
433 | } | |
434 | else if (cannot_lead_to_return) | |
435 | { | |
436 | *state = IPA_PURE; | |
437 | *looping = true; | |
438 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
439 | fprintf (dump_file, " ignoring side effects->pure looping\n"); | |
440 | } | |
441 | else | |
442 | { | |
443 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
9631926a | 444 | fprintf (dump_file, " neither\n"); |
023a28e1 | 445 | *state = IPA_NEITHER; |
446 | *looping = true; | |
447 | } | |
448 | } | |
449 | ||
450 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
451 | into STATE and LOOPING better of the two variants. | |
452 | Be sure to merge looping correctly. IPA_NEITHER functions | |
453 | have looping 0 even if they don't have to return. */ | |
454 | ||
455 | static inline void | |
456 | better_state (enum pure_const_state_e *state, bool *looping, | |
457 | enum pure_const_state_e state2, bool looping2) | |
458 | { | |
459 | if (state2 < *state) | |
460 | { | |
461 | if (*state == IPA_NEITHER) | |
462 | *looping = looping2; | |
463 | else | |
464 | *looping = MIN (*looping, looping2); | |
26fc128e | 465 | *state = state2; |
023a28e1 | 466 | } |
467 | else if (state2 != IPA_NEITHER) | |
468 | *looping = MIN (*looping, looping2); | |
469 | } | |
470 | ||
471 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
8b4ee73c | 472 | into STATE and LOOPING worse of the two variants. |
473 | N is the actual node called. */ | |
023a28e1 | 474 | |
475 | static inline void | |
476 | worse_state (enum pure_const_state_e *state, bool *looping, | |
8b4ee73c | 477 | enum pure_const_state_e state2, bool looping2, |
478 | struct symtab_node *from, | |
479 | struct symtab_node *to) | |
023a28e1 | 480 | { |
8b4ee73c | 481 | /* Consider function: |
482 | ||
483 | bool a(int *p) | |
484 | { | |
485 | return *p==*p; | |
486 | } | |
487 | ||
488 | During early optimization we will turn this into: | |
489 | ||
490 | bool a(int *p) | |
491 | { | |
492 | return true; | |
493 | } | |
494 | ||
495 | Now if this function will be detected as CONST however when interposed it | |
496 | may end up being just pure. We always must assume the worst scenario here. | |
497 | */ | |
498 | if (*state == IPA_CONST && state2 == IPA_CONST | |
499 | && to && !TREE_READONLY (to->decl) && !to->binds_to_current_def_p (from)) | |
500 | { | |
501 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
502 | fprintf (dump_file, "Dropping state to PURE because call to %s may not " | |
503 | "bind to current def.\n", to->name ()); | |
504 | state2 = IPA_PURE; | |
505 | } | |
023a28e1 | 506 | *state = MAX (*state, state2); |
507 | *looping = MAX (*looping, looping2); | |
508 | } | |
509 | ||
0a10fd82 | 510 | /* Recognize special cases of builtins that are by themselves not pure or const |
7dd42908 | 511 | but function using them is. */ |
512 | static bool | |
a53e7471 | 513 | special_builtin_state (enum pure_const_state_e *state, bool *looping, |
7dd42908 | 514 | tree callee) |
515 | { | |
516 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
517 | switch (DECL_FUNCTION_CODE (callee)) | |
518 | { | |
519 | case BUILT_IN_RETURN: | |
520 | case BUILT_IN_UNREACHABLE: | |
2b34677f | 521 | CASE_BUILT_IN_ALLOCA: |
7dd42908 | 522 | case BUILT_IN_STACK_SAVE: |
523 | case BUILT_IN_STACK_RESTORE: | |
524 | case BUILT_IN_EH_POINTER: | |
525 | case BUILT_IN_EH_FILTER: | |
526 | case BUILT_IN_UNWIND_RESUME: | |
527 | case BUILT_IN_CXA_END_CLEANUP: | |
528 | case BUILT_IN_EH_COPY_VALUES: | |
529 | case BUILT_IN_FRAME_ADDRESS: | |
530 | case BUILT_IN_APPLY: | |
531 | case BUILT_IN_APPLY_ARGS: | |
a940fdc7 | 532 | case BUILT_IN_ASAN_BEFORE_DYNAMIC_INIT: |
533 | case BUILT_IN_ASAN_AFTER_DYNAMIC_INIT: | |
7dd42908 | 534 | *looping = false; |
535 | *state = IPA_CONST; | |
536 | return true; | |
537 | case BUILT_IN_PREFETCH: | |
538 | *looping = true; | |
539 | *state = IPA_CONST; | |
540 | return true; | |
5213d6c9 | 541 | default: |
542 | break; | |
7dd42908 | 543 | } |
544 | return false; | |
545 | } | |
546 | ||
f7d118a9 | 547 | /* Check the parameters of a function call to CALL_EXPR to see if |
548 | there are any references in the parameters that are not allowed for | |
549 | pure or const functions. Also check to see if this is either an | |
550 | indirect call, a call outside the compilation unit, or has special | |
551 | attributes that may also effect the purity. The CALL_EXPR node for | |
552 | the entire call expression. */ | |
553 | ||
554 | static void | |
1a91d914 | 555 | check_call (funct_state local, gcall *call, bool ipa) |
f7d118a9 | 556 | { |
75a70cf9 | 557 | int flags = gimple_call_flags (call); |
b5cebd44 | 558 | tree callee_t = gimple_call_fndecl (call); |
aac19106 | 559 | bool possibly_throws = stmt_could_throw_p (cfun, call); |
b5cebd44 | 560 | bool possibly_throws_externally = (possibly_throws |
aac19106 | 561 | && stmt_can_throw_external (cfun, call)); |
f7d118a9 | 562 | |
b5cebd44 | 563 | if (possibly_throws) |
564 | { | |
565 | unsigned int i; | |
566 | for (i = 0; i < gimple_num_ops (call); i++) | |
567 | if (gimple_op (call, i) | |
568 | && tree_could_throw_p (gimple_op (call, i))) | |
569 | { | |
cbeb677e | 570 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 571 | { |
572 | if (dump_file) | |
573 | fprintf (dump_file, " operand can throw; looping\n"); | |
574 | local->looping = true; | |
575 | } | |
576 | if (possibly_throws_externally) | |
577 | { | |
578 | if (dump_file) | |
579 | fprintf (dump_file, " operand can throw externally\n"); | |
580 | local->can_throw = true; | |
581 | } | |
582 | } | |
583 | } | |
48e1416a | 584 | |
f7d118a9 | 585 | /* The const and pure flags are set by a variety of places in the |
586 | compiler (including here). If someone has already set the flags | |
587 | for the callee, (such as for some of the builtins) we will use | |
48e1416a | 588 | them, otherwise we will compute our own information. |
589 | ||
f7d118a9 | 590 | Const and pure functions have less clobber effects than other |
591 | functions so we process these first. Otherwise if it is a call | |
592 | outside the compilation unit or an indirect call we punt. This | |
593 | leaves local calls which will be processed by following the call | |
48e1416a | 594 | graph. */ |
f7d118a9 | 595 | if (callee_t) |
596 | { | |
7dd42908 | 597 | enum pure_const_state_e call_state; |
598 | bool call_looping; | |
599 | ||
04c849b3 | 600 | if (gimple_call_builtin_p (call, BUILT_IN_NORMAL) |
601 | && !nonfreeing_call_p (call)) | |
602 | local->can_free = true; | |
603 | ||
a53e7471 | 604 | if (special_builtin_state (&call_state, &call_looping, callee_t)) |
7dd42908 | 605 | { |
606 | worse_state (&local->pure_const_state, &local->looping, | |
8b4ee73c | 607 | call_state, call_looping, |
608 | NULL, NULL); | |
7dd42908 | 609 | return; |
610 | } | |
f7d118a9 | 611 | /* When bad things happen to bad functions, they cannot be const |
612 | or pure. */ | |
613 | if (setjmp_call_p (callee_t)) | |
9c2a0c05 | 614 | { |
b5cebd44 | 615 | if (dump_file) |
616 | fprintf (dump_file, " setjmp is not const/pure\n"); | |
617 | local->looping = true; | |
9c2a0c05 | 618 | local->pure_const_state = IPA_NEITHER; |
9c2a0c05 | 619 | } |
f7d118a9 | 620 | |
621 | if (DECL_BUILT_IN_CLASS (callee_t) == BUILT_IN_NORMAL) | |
622 | switch (DECL_FUNCTION_CODE (callee_t)) | |
623 | { | |
624 | case BUILT_IN_LONGJMP: | |
625 | case BUILT_IN_NONLOCAL_GOTO: | |
b5cebd44 | 626 | if (dump_file) |
627 | fprintf (dump_file, " longjmp and nonlocal goto is not const/pure\n"); | |
f7d118a9 | 628 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 629 | local->looping = true; |
f7d118a9 | 630 | break; |
631 | default: | |
632 | break; | |
633 | } | |
634 | } | |
04c849b3 | 635 | else if (gimple_call_internal_p (call) && !nonfreeing_call_p (call)) |
636 | local->can_free = true; | |
f7d118a9 | 637 | |
b5cebd44 | 638 | /* When not in IPA mode, we can still handle self recursion. */ |
e9de52cc | 639 | if (!ipa && callee_t |
640 | && recursive_call_p (current_function_decl, callee_t)) | |
2c06958d | 641 | { |
642 | if (dump_file) | |
643 | fprintf (dump_file, " Recursive call can loop.\n"); | |
644 | local->looping = true; | |
645 | } | |
0a10fd82 | 646 | /* Either callee is unknown or we are doing local analysis. |
ef378c27 | 647 | Look to see if there are any bits available for the callee (such as by |
648 | declaration or because it is builtin) and process solely on the basis of | |
621733d8 | 649 | those bits. Handle internal calls always, those calls don't have |
650 | corresponding cgraph edges and thus aren't processed during | |
651 | the propagation. */ | |
652 | else if (!ipa || gimple_call_internal_p (call)) | |
f7d118a9 | 653 | { |
023a28e1 | 654 | enum pure_const_state_e call_state; |
655 | bool call_looping; | |
cbeb677e | 656 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 657 | { |
658 | if (dump_file) | |
659 | fprintf (dump_file, " can throw; looping\n"); | |
660 | local->looping = true; | |
661 | } | |
662 | if (possibly_throws_externally) | |
663 | { | |
664 | if (dump_file) | |
665 | { | |
e38def9c | 666 | fprintf (dump_file, " can throw externally to lp %i\n", |
667 | lookup_stmt_eh_lp (call)); | |
b5cebd44 | 668 | if (callee_t) |
669 | fprintf (dump_file, " callee:%s\n", | |
670 | IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (callee_t))); | |
671 | } | |
672 | local->can_throw = true; | |
673 | } | |
023a28e1 | 674 | if (dump_file && (dump_flags & TDF_DETAILS)) |
675 | fprintf (dump_file, " checking flags for call:"); | |
676 | state_from_flags (&call_state, &call_looping, flags, | |
677 | ((flags & (ECF_NORETURN | ECF_NOTHROW)) | |
678 | == (ECF_NORETURN | ECF_NOTHROW)) | |
679 | || (!flag_exceptions && (flags & ECF_NORETURN))); | |
680 | worse_state (&local->pure_const_state, &local->looping, | |
8b4ee73c | 681 | call_state, call_looping, NULL, NULL); |
f7d118a9 | 682 | } |
b5cebd44 | 683 | /* Direct functions calls are handled by IPA propagation. */ |
f7d118a9 | 684 | } |
685 | ||
023a28e1 | 686 | /* Wrapper around check_decl for loads in local more. */ |
5ed0b345 | 687 | |
688 | static bool | |
42acab1c | 689 | check_load (gimple *, tree op, tree, void *data) |
5ed0b345 | 690 | { |
691 | if (DECL_P (op)) | |
023a28e1 | 692 | check_decl ((funct_state)data, op, false, false); |
5ed0b345 | 693 | else |
694 | check_op ((funct_state)data, op, false); | |
695 | return false; | |
696 | } | |
697 | ||
023a28e1 | 698 | /* Wrapper around check_decl for stores in local more. */ |
5ed0b345 | 699 | |
700 | static bool | |
42acab1c | 701 | check_store (gimple *, tree op, tree, void *data) |
5ed0b345 | 702 | { |
703 | if (DECL_P (op)) | |
023a28e1 | 704 | check_decl ((funct_state)data, op, true, false); |
705 | else | |
706 | check_op ((funct_state)data, op, true); | |
707 | return false; | |
708 | } | |
709 | ||
710 | /* Wrapper around check_decl for loads in ipa mode. */ | |
711 | ||
712 | static bool | |
42acab1c | 713 | check_ipa_load (gimple *, tree op, tree, void *data) |
023a28e1 | 714 | { |
715 | if (DECL_P (op)) | |
716 | check_decl ((funct_state)data, op, false, true); | |
717 | else | |
718 | check_op ((funct_state)data, op, false); | |
719 | return false; | |
720 | } | |
721 | ||
722 | /* Wrapper around check_decl for stores in ipa mode. */ | |
723 | ||
724 | static bool | |
42acab1c | 725 | check_ipa_store (gimple *, tree op, tree, void *data) |
023a28e1 | 726 | { |
727 | if (DECL_P (op)) | |
728 | check_decl ((funct_state)data, op, true, true); | |
5ed0b345 | 729 | else |
730 | check_op ((funct_state)data, op, true); | |
731 | return false; | |
732 | } | |
733 | ||
dd277d48 | 734 | /* Look into pointer pointed to by GSIP and figure out what interesting side |
735 | effects it has. */ | |
b5cebd44 | 736 | static void |
737 | check_stmt (gimple_stmt_iterator *gsip, funct_state local, bool ipa) | |
f7d118a9 | 738 | { |
42acab1c | 739 | gimple *stmt = gsi_stmt (*gsip); |
f7d118a9 | 740 | |
9845d120 | 741 | if (is_gimple_debug (stmt)) |
742 | return; | |
743 | ||
73594827 | 744 | /* Do consider clobber as side effects before IPA, so we rather inline |
745 | C++ destructors and keep clobber semantics than eliminate them. | |
746 | ||
747 | TODO: We may get smarter during early optimizations on these and let | |
748 | functions containing only clobbers to be optimized more. This is a common | |
749 | case of C++ destructors. */ | |
750 | ||
751 | if ((ipa || cfun->after_inlining) && gimple_clobber_p (stmt)) | |
752 | return; | |
753 | ||
b5cebd44 | 754 | if (dump_file) |
f7d118a9 | 755 | { |
b5cebd44 | 756 | fprintf (dump_file, " scanning: "); |
1ffa4346 | 757 | print_gimple_stmt (dump_file, stmt, 0); |
b5cebd44 | 758 | } |
dd277d48 | 759 | |
541c6dbb | 760 | if (gimple_has_volatile_ops (stmt) |
761 | && !gimple_clobber_p (stmt)) | |
4b68df2e | 762 | { |
763 | local->pure_const_state = IPA_NEITHER; | |
764 | if (dump_file) | |
765 | fprintf (dump_file, " Volatile stmt is not const/pure\n"); | |
766 | } | |
767 | ||
5ed0b345 | 768 | /* Look for loads and stores. */ |
023a28e1 | 769 | walk_stmt_load_store_ops (stmt, local, |
770 | ipa ? check_ipa_load : check_load, | |
771 | ipa ? check_ipa_store : check_store); | |
b5cebd44 | 772 | |
773 | if (gimple_code (stmt) != GIMPLE_CALL | |
aac19106 | 774 | && stmt_could_throw_p (cfun, stmt)) |
b5cebd44 | 775 | { |
cbeb677e | 776 | if (cfun->can_throw_non_call_exceptions) |
b5cebd44 | 777 | { |
778 | if (dump_file) | |
10f4615f | 779 | fprintf (dump_file, " can throw; looping\n"); |
b5cebd44 | 780 | local->looping = true; |
781 | } | |
aac19106 | 782 | if (stmt_can_throw_external (cfun, stmt)) |
b5cebd44 | 783 | { |
784 | if (dump_file) | |
10f4615f | 785 | fprintf (dump_file, " can throw externally\n"); |
b5cebd44 | 786 | local->can_throw = true; |
787 | } | |
10f4615f | 788 | else |
789 | if (dump_file) | |
790 | fprintf (dump_file, " can throw\n"); | |
75a70cf9 | 791 | } |
75a70cf9 | 792 | switch (gimple_code (stmt)) |
793 | { | |
b5cebd44 | 794 | case GIMPLE_CALL: |
1a91d914 | 795 | check_call (local, as_a <gcall *> (stmt), ipa); |
f7d118a9 | 796 | break; |
75a70cf9 | 797 | case GIMPLE_LABEL: |
1a91d914 | 798 | if (DECL_NONLOCAL (gimple_label_label (as_a <glabel *> (stmt)))) |
f7d118a9 | 799 | /* Target of long jump. */ |
9c2a0c05 | 800 | { |
b5cebd44 | 801 | if (dump_file) |
10f4615f | 802 | fprintf (dump_file, " nonlocal label is not const/pure\n"); |
9c2a0c05 | 803 | local->pure_const_state = IPA_NEITHER; |
9c2a0c05 | 804 | } |
f7d118a9 | 805 | break; |
75a70cf9 | 806 | case GIMPLE_ASM: |
1a91d914 | 807 | if (gimple_asm_clobbers_memory_p (as_a <gasm *> (stmt))) |
b5cebd44 | 808 | { |
97cf41ec | 809 | if (dump_file) |
10f4615f | 810 | fprintf (dump_file, " memory asm clobber is not const/pure\n"); |
97cf41ec | 811 | /* Abandon all hope, ye who enter here. */ |
812 | local->pure_const_state = IPA_NEITHER; | |
04c849b3 | 813 | local->can_free = true; |
b5cebd44 | 814 | } |
1a91d914 | 815 | if (gimple_asm_volatile_p (as_a <gasm *> (stmt))) |
b5cebd44 | 816 | { |
817 | if (dump_file) | |
10f4615f | 818 | fprintf (dump_file, " volatile is not const/pure\n"); |
b5cebd44 | 819 | /* Abandon all hope, ye who enter here. */ |
820 | local->pure_const_state = IPA_NEITHER; | |
04c849b3 | 821 | local->looping = true; |
822 | local->can_free = true; | |
b5cebd44 | 823 | } |
824 | return; | |
f7d118a9 | 825 | default: |
826 | break; | |
827 | } | |
f7d118a9 | 828 | } |
829 | ||
bd5ef087 | 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 | ||
bd5ef087 | 873 | #define DUMP_AND_RETURN(reason) \ |
874 | { \ | |
875 | if (dump_file && (dump_flags & TDF_DETAILS)) \ | |
d51fd3fc | 876 | fprintf (dump_file, "\n%s is not a malloc candidate, reason: %s\n", \ |
877 | (node->name()), (reason)); \ | |
bd5ef087 | 878 | return false; \ |
879 | } | |
880 | ||
18ea7971 | 881 | static bool |
b5f91d03 | 882 | malloc_candidate_p_1 (function *fun, tree retval, gimple *ret_stmt, bool ipa, |
883 | bitmap visited) | |
18ea7971 | 884 | { |
885 | cgraph_node *node = cgraph_node::get_create (fun->decl); | |
b5f91d03 | 886 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (retval))) |
887 | return true; | |
18ea7971 | 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 | { | |
b5f91d03 | 932 | if (!malloc_candidate_p_1 (fun, arg, phi, ipa, visited)) |
18ea7971 | 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 | ||
d51fd3fc | 974 | if (EDGE_COUNT (exit_block->preds) == 0 |
975 | || !flag_delete_null_pointer_checks) | |
bd5ef087 | 976 | return false; |
977 | ||
b5f91d03 | 978 | auto_bitmap visited; |
bd5ef087 | 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 | ||
b5f91d03 | 995 | if (!malloc_candidate_p_1 (fun, retval, ret_stmt, ipa, visited)) |
18ea7971 | 996 | return false; |
bd5ef087 | 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; | |
bd5ef087 | 1003 | } |
1004 | ||
18ea7971 | 1005 | #undef DUMP_AND_RETURN |
cb886925 | 1006 | |
f7d118a9 | 1007 | /* This is the main routine for finding the reference patterns for |
1008 | global variables within a function FN. */ | |
1009 | ||
b5cebd44 | 1010 | static funct_state |
1011 | analyze_function (struct cgraph_node *fn, bool ipa) | |
f7d118a9 | 1012 | { |
02774f2d | 1013 | tree decl = fn->decl; |
b5cebd44 | 1014 | funct_state l; |
1015 | basic_block this_block; | |
f7d118a9 | 1016 | |
2e966e2a | 1017 | l = XCNEW (class funct_state_d); |
b5cebd44 | 1018 | l->pure_const_state = IPA_CONST; |
df9b545b | 1019 | l->state_previously_known = IPA_NEITHER; |
1020 | l->looping_previously_known = true; | |
b5cebd44 | 1021 | l->looping = false; |
1022 | l->can_throw = false; | |
04c849b3 | 1023 | l->can_free = false; |
91bf9d9a | 1024 | state_from_flags (&l->state_previously_known, &l->looping_previously_known, |
02774f2d | 1025 | flags_from_decl_or_type (fn->decl), |
415d1b9a | 1026 | fn->cannot_return_p ()); |
91bf9d9a | 1027 | |
02774f2d | 1028 | if (fn->thunk.thunk_p || fn->alias) |
91bf9d9a | 1029 | { |
1030 | /* Thunk gets propagated through, so nothing interesting happens. */ | |
1031 | gcc_assert (ipa); | |
cfd85d03 | 1032 | if (fn->thunk.thunk_p && fn->thunk.virtual_offset_p) |
1033 | l->pure_const_state = IPA_NEITHER; | |
91bf9d9a | 1034 | return l; |
1035 | } | |
f7d118a9 | 1036 | |
1037 | if (dump_file) | |
1038 | { | |
48e1416a | 1039 | fprintf (dump_file, "\n\n local analysis of %s\n ", |
f1c8b4d7 | 1040 | fn->name ()); |
f7d118a9 | 1041 | } |
48e1416a | 1042 | |
b5cebd44 | 1043 | push_cfun (DECL_STRUCT_FUNCTION (decl)); |
48e1416a | 1044 | |
fc00614f | 1045 | FOR_EACH_BB_FN (this_block, cfun) |
f7d118a9 | 1046 | { |
b5cebd44 | 1047 | gimple_stmt_iterator gsi; |
1048 | struct walk_stmt_info wi; | |
f7d118a9 | 1049 | |
9af5ce0c | 1050 | memset (&wi, 0, sizeof (wi)); |
b5cebd44 | 1051 | for (gsi = gsi_start_bb (this_block); |
1052 | !gsi_end_p (gsi); | |
1053 | gsi_next (&gsi)) | |
f7d118a9 | 1054 | { |
b5cebd44 | 1055 | check_stmt (&gsi, l, ipa); |
04c849b3 | 1056 | if (l->pure_const_state == IPA_NEITHER |
1057 | && l->looping | |
1058 | && l->can_throw | |
1059 | && l->can_free) | |
b5cebd44 | 1060 | goto end; |
f7d118a9 | 1061 | } |
1062 | } | |
dcccac3e | 1063 | |
1064 | end: | |
b5cebd44 | 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 ()) | |
c9263b6a | 1071 | { |
b1887855 | 1072 | /* Preheaders are needed for SCEV to work. |
0a10fd82 | 1073 | Simple latches and recorded exits improve chances that loop will |
8ff30f9a | 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 | |
b1887855 | 1078 | | LOOPS_HAVE_RECORDED_EXITS); |
c9263b6a | 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 | } | |
48e1416a | 1087 | else |
c9263b6a | 1088 | { |
2e966e2a | 1089 | class loop *loop; |
c9263b6a | 1090 | scev_initialize (); |
f21d4d00 | 1091 | FOR_EACH_LOOP (loop, 0) |
c9263b6a | 1092 | if (!finite_loop_p (loop)) |
1093 | { | |
1094 | if (dump_file) | |
f4d3c071 | 1095 | fprintf (dump_file, " cannot prove finiteness of " |
8ff30f9a | 1096 | "loop %i\n", loop->num); |
c9263b6a | 1097 | l->looping =true; |
f21d4d00 | 1098 | break; |
c9263b6a | 1099 | } |
1100 | scev_finalize (); | |
1101 | } | |
1102 | loop_optimizer_finalize (); | |
1103 | } | |
b5cebd44 | 1104 | } |
1105 | ||
023a28e1 | 1106 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1107 | fprintf (dump_file, " checking previously known:"); | |
023a28e1 | 1108 | |
1109 | better_state (&l->pure_const_state, &l->looping, | |
1110 | l->state_previously_known, | |
1111 | l->looping_previously_known); | |
b5cebd44 | 1112 | if (TREE_NOTHROW (decl)) |
1113 | l->can_throw = false; | |
1114 | ||
bd5ef087 | 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 | ||
b5cebd44 | 1123 | pop_cfun (); |
dcccac3e | 1124 | if (dump_file) |
1125 | { | |
b5cebd44 | 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"); | |
04c849b3 | 1134 | if (l->can_free) |
1135 | fprintf (dump_file, "Function can locally free.\n"); | |
bd5ef087 | 1136 | if (l->malloc_state == STATE_MALLOC) |
1137 | fprintf (dump_file, "Function is locally malloc.\n"); | |
dcccac3e | 1138 | } |
b5cebd44 | 1139 | return l; |
f7d118a9 | 1140 | } |
1141 | ||
16f72bd0 | 1142 | void |
1143 | funct_state_summary_t::insert (cgraph_node *node, funct_state_d *state) | |
50828ed8 | 1144 | { |
50828ed8 | 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. */ | |
8b4ee73c | 1149 | if (opt_for_fn (node->decl, flag_ipa_pure_const)) |
86844d6c | 1150 | { |
16f72bd0 | 1151 | funct_state_d *a = analyze_function (node, true); |
1152 | new (state) funct_state_d (*a); | |
1153 | free (a); | |
86844d6c | 1154 | } |
1155 | } | |
1156 | ||
1157 | /* Called when new clone is inserted to callgraph late. */ | |
1158 | ||
16f72bd0 | 1159 | void |
1160 | funct_state_summary_t::duplicate (cgraph_node *, cgraph_node *, | |
1161 | funct_state_d *src_data, | |
1162 | funct_state_d *dst_data) | |
86844d6c | 1163 | { |
16f72bd0 | 1164 | new (dst_data) funct_state_d (*src_data); |
86844d6c | 1165 | } |
1166 | ||
f7d118a9 | 1167 | \f |
415309e2 | 1168 | void |
1169 | pass_ipa_pure_const:: | |
7bfefa9d | 1170 | register_hooks (void) |
f7d118a9 | 1171 | { |
7bfefa9d | 1172 | if (init_p) |
1173 | return; | |
1174 | ||
1175 | init_p = true; | |
f7d118a9 | 1176 | |
16f72bd0 | 1177 | funct_state_summaries = new funct_state_summary_t (symtab); |
7bfefa9d | 1178 | } |
1179 | ||
1180 | ||
1181 | /* Analyze each function in the cgraph to see if it is locally PURE or | |
1182 | CONST. */ | |
1183 | ||
48e1416a | 1184 | static void |
80880eb6 | 1185 | pure_const_generate_summary (void) |
7bfefa9d | 1186 | { |
1187 | struct cgraph_node *node; | |
1188 | ||
415309e2 | 1189 | pass_ipa_pure_const *pass = static_cast <pass_ipa_pure_const *> (current_pass); |
1190 | pass->register_hooks (); | |
7bfefa9d | 1191 | |
48e1416a | 1192 | /* Process all of the functions. |
f7d118a9 | 1193 | |
f4d3c071 | 1194 | We process AVAIL_INTERPOSABLE functions. We cannot use the results |
ef378c27 | 1195 | by default, but the info can be used at LTO with -fwhole-program or |
0a10fd82 | 1196 | when function got cloned and the clone is AVAILABLE. */ |
ef378c27 | 1197 | |
7c455d87 | 1198 | FOR_EACH_DEFINED_FUNCTION (node) |
8b4ee73c | 1199 | if (opt_for_fn (node->decl, flag_ipa_pure_const)) |
16f72bd0 | 1200 | { |
1201 | funct_state_d *a = analyze_function (node, true); | |
1202 | new (funct_state_summaries->get_create (node)) funct_state_d (*a); | |
1203 | free (a); | |
1204 | } | |
cb886925 | 1205 | } |
1206 | ||
7bfefa9d | 1207 | |
1208 | /* Serialize the ipa info for lto. */ | |
1209 | ||
1210 | static void | |
eab36a5a | 1211 | pure_const_write_summary (void) |
7bfefa9d | 1212 | { |
1213 | struct cgraph_node *node; | |
1214 | struct lto_simple_output_block *ob | |
1215 | = lto_create_simple_output_block (LTO_section_ipa_pure_const); | |
1216 | unsigned int count = 0; | |
eab36a5a | 1217 | lto_symtab_encoder_iterator lsei; |
1218 | lto_symtab_encoder_t encoder; | |
7bfefa9d | 1219 | |
eab36a5a | 1220 | encoder = lto_get_out_decl_state ()->symtab_node_encoder; |
1221 | ||
1222 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); | |
1223 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 1224 | { |
eab36a5a | 1225 | node = lsei_cgraph_node (lsei); |
16f72bd0 | 1226 | if (node->definition && funct_state_summaries->exists (node)) |
7bfefa9d | 1227 | count++; |
1228 | } | |
48e1416a | 1229 | |
7f385784 | 1230 | streamer_write_uhwi_stream (ob->main_stream, count); |
48e1416a | 1231 | |
7bfefa9d | 1232 | /* Process all of the functions. */ |
eab36a5a | 1233 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); |
1234 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 1235 | { |
eab36a5a | 1236 | node = lsei_cgraph_node (lsei); |
16f72bd0 | 1237 | funct_state_d *fs = funct_state_summaries->get (node); |
1238 | if (node->definition && fs != NULL) | |
7bfefa9d | 1239 | { |
30baba90 | 1240 | struct bitpack_d bp; |
7bfefa9d | 1241 | int node_ref; |
70225339 | 1242 | lto_symtab_encoder_t encoder; |
48e1416a | 1243 | |
70225339 | 1244 | encoder = ob->decl_state->symtab_node_encoder; |
02774f2d | 1245 | node_ref = lto_symtab_encoder_encode (encoder, node); |
7f385784 | 1246 | streamer_write_uhwi_stream (ob->main_stream, node_ref); |
48e1416a | 1247 | |
7bfefa9d | 1248 | /* Note that flags will need to be read in the opposite |
1249 | order as we are pushing the bitflags into FLAGS. */ | |
30baba90 | 1250 | bp = bitpack_create (ob->main_stream); |
1251 | bp_pack_value (&bp, fs->pure_const_state, 2); | |
1252 | bp_pack_value (&bp, fs->state_previously_known, 2); | |
1253 | bp_pack_value (&bp, fs->looping_previously_known, 1); | |
1254 | bp_pack_value (&bp, fs->looping, 1); | |
1255 | bp_pack_value (&bp, fs->can_throw, 1); | |
04c849b3 | 1256 | bp_pack_value (&bp, fs->can_free, 1); |
bd5ef087 | 1257 | bp_pack_value (&bp, fs->malloc_state, 2); |
7f385784 | 1258 | streamer_write_bitpack (&bp); |
7bfefa9d | 1259 | } |
1260 | } | |
1261 | ||
1262 | lto_destroy_simple_output_block (ob); | |
1263 | } | |
1264 | ||
1265 | ||
1266 | /* Deserialize the ipa info for lto. */ | |
1267 | ||
48e1416a | 1268 | static void |
7bfefa9d | 1269 | pure_const_read_summary (void) |
1270 | { | |
1271 | struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); | |
1272 | struct lto_file_decl_data *file_data; | |
1273 | unsigned int j = 0; | |
1274 | ||
415309e2 | 1275 | pass_ipa_pure_const *pass = static_cast <pass_ipa_pure_const *> (current_pass); |
1276 | pass->register_hooks (); | |
1277 | ||
7bfefa9d | 1278 | while ((file_data = file_data_vec[j++])) |
1279 | { | |
1280 | const char *data; | |
1281 | size_t len; | |
2e966e2a | 1282 | class lto_input_block *ib |
48e1416a | 1283 | = lto_create_simple_input_block (file_data, |
1284 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1285 | &data, &len); |
1286 | if (ib) | |
1287 | { | |
1288 | unsigned int i; | |
7f385784 | 1289 | unsigned int count = streamer_read_uhwi (ib); |
7bfefa9d | 1290 | |
1291 | for (i = 0; i < count; i++) | |
1292 | { | |
1293 | unsigned int index; | |
1294 | struct cgraph_node *node; | |
30baba90 | 1295 | struct bitpack_d bp; |
7bfefa9d | 1296 | funct_state fs; |
70225339 | 1297 | lto_symtab_encoder_t encoder; |
7bfefa9d | 1298 | |
7f385784 | 1299 | index = streamer_read_uhwi (ib); |
70225339 | 1300 | encoder = file_data->symtab_node_encoder; |
415d1b9a | 1301 | node = dyn_cast<cgraph_node *> (lto_symtab_encoder_deref (encoder, |
1302 | index)); | |
7bfefa9d | 1303 | |
16f72bd0 | 1304 | fs = funct_state_summaries->get_create (node); |
7bfefa9d | 1305 | /* Note that the flags must be read in the opposite |
1306 | order in which they were written (the bitflags were | |
1307 | pushed into FLAGS). */ | |
7f385784 | 1308 | bp = streamer_read_bitpack (ib); |
7bfefa9d | 1309 | fs->pure_const_state |
30baba90 | 1310 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
7bfefa9d | 1311 | fs->state_previously_known |
30baba90 | 1312 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
1313 | fs->looping_previously_known = bp_unpack_value (&bp, 1); | |
1314 | fs->looping = bp_unpack_value (&bp, 1); | |
1315 | fs->can_throw = bp_unpack_value (&bp, 1); | |
04c849b3 | 1316 | fs->can_free = bp_unpack_value (&bp, 1); |
bd5ef087 | 1317 | fs->malloc_state |
1318 | = (enum malloc_state_e) bp_unpack_value (&bp, 2); | |
1319 | ||
fc94a528 | 1320 | if (dump_file) |
1321 | { | |
02774f2d | 1322 | int flags = flags_from_decl_or_type (node->decl); |
0e388735 | 1323 | fprintf (dump_file, "Read info for %s ", node->dump_name ()); |
fc94a528 | 1324 | if (flags & ECF_CONST) |
1325 | fprintf (dump_file, " const"); | |
1326 | if (flags & ECF_PURE) | |
1327 | fprintf (dump_file, " pure"); | |
1328 | if (flags & ECF_NOTHROW) | |
1329 | fprintf (dump_file, " nothrow"); | |
1330 | fprintf (dump_file, "\n pure const state: %s\n", | |
1331 | pure_const_names[fs->pure_const_state]); | |
1332 | fprintf (dump_file, " previously known state: %s\n", | |
8b4ee73c | 1333 | pure_const_names[fs->state_previously_known]); |
fc94a528 | 1334 | if (fs->looping) |
1335 | fprintf (dump_file," function is locally looping\n"); | |
1336 | if (fs->looping_previously_known) | |
1337 | fprintf (dump_file," function is previously known looping\n"); | |
1338 | if (fs->can_throw) | |
1339 | fprintf (dump_file," function is locally throwing\n"); | |
04c849b3 | 1340 | if (fs->can_free) |
1341 | fprintf (dump_file," function can locally free\n"); | |
bd5ef087 | 1342 | fprintf (dump_file, "\n malloc state: %s\n", |
1343 | malloc_state_names[fs->malloc_state]); | |
fc94a528 | 1344 | } |
7bfefa9d | 1345 | } |
1346 | ||
48e1416a | 1347 | lto_destroy_simple_input_block (file_data, |
1348 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1349 | ib, data, len); |
1350 | } | |
1351 | } | |
1352 | } | |
1353 | ||
355c1f40 | 1354 | /* We only propagate across edges that can throw externally and their callee |
1355 | is not interposable. */ | |
7bfefa9d | 1356 | |
17b28e52 | 1357 | static bool |
355c1f40 | 1358 | ignore_edge_for_nothrow (struct cgraph_edge *e) |
17b28e52 | 1359 | { |
355c1f40 | 1360 | if (!e->can_throw_external || TREE_NOTHROW (e->callee->decl)) |
1361 | return true; | |
1362 | ||
1363 | enum availability avail; | |
d02f3bb1 | 1364 | cgraph_node *ultimate_target |
1365 | = e->callee->function_or_virtual_thunk_symbol (&avail, e->caller); | |
1366 | if (avail <= AVAIL_INTERPOSABLE || TREE_NOTHROW (ultimate_target->decl)) | |
ace7bf06 | 1367 | return true; |
d02f3bb1 | 1368 | return ((opt_for_fn (e->callee->decl, flag_non_call_exceptions) |
1369 | && !e->callee->binds_to_current_def_p (e->caller)) | |
1370 | || !opt_for_fn (e->caller->decl, flag_ipa_pure_const) | |
1371 | || !opt_for_fn (ultimate_target->decl, flag_ipa_pure_const)); | |
17b28e52 | 1372 | } |
1373 | ||
b2c2e188 | 1374 | /* Return true if NODE is self recursive function. |
e9de52cc | 1375 | Indirectly recursive functions appears as non-trivial strongly |
1376 | connected components, so we need to care about self recursion | |
1377 | only. */ | |
a1e88032 | 1378 | |
1379 | static bool | |
1380 | self_recursive_p (struct cgraph_node *node) | |
1381 | { | |
1382 | struct cgraph_edge *e; | |
1383 | for (e = node->callees; e; e = e->next_callee) | |
415d1b9a | 1384 | if (e->callee->function_symbol () == node) |
a1e88032 | 1385 | return true; |
1386 | return false; | |
1387 | } | |
1388 | ||
366970c6 | 1389 | /* Return true if N is cdtor that is not const or pure. In this case we may |
1390 | need to remove unreachable function if it is marked const/pure. */ | |
1391 | ||
1392 | static bool | |
1393 | cdtor_p (cgraph_node *n, void *) | |
1394 | { | |
1395 | if (DECL_STATIC_CONSTRUCTOR (n->decl) || DECL_STATIC_DESTRUCTOR (n->decl)) | |
98b8f2a5 | 1396 | return ((!TREE_READONLY (n->decl) && !DECL_PURE_P (n->decl)) |
1397 | || DECL_LOOPING_CONST_OR_PURE_P (n->decl)); | |
366970c6 | 1398 | return false; |
1399 | } | |
1400 | ||
d02f3bb1 | 1401 | /* Skip edges from and to nodes without ipa_pure_const enabled. |
1402 | Ignore not available symbols. */ | |
d2c6c2b4 | 1403 | |
1404 | static bool | |
1405 | ignore_edge_for_pure_const (struct cgraph_edge *e) | |
1406 | { | |
1407 | enum availability avail; | |
d02f3bb1 | 1408 | cgraph_node *ultimate_target |
1409 | = e->callee->function_or_virtual_thunk_symbol (&avail, e->caller); | |
d2c6c2b4 | 1410 | |
d02f3bb1 | 1411 | return (avail <= AVAIL_INTERPOSABLE |
1412 | || !opt_for_fn (e->caller->decl, flag_ipa_pure_const) | |
1413 | || !opt_for_fn (ultimate_target->decl, | |
1414 | flag_ipa_pure_const)); | |
1415 | } | |
d2c6c2b4 | 1416 | |
c0240443 | 1417 | /* Produce transitive closure over the callgraph and compute pure/const |
1418 | attributes. */ | |
023a28e1 | 1419 | |
366970c6 | 1420 | static bool |
c0240443 | 1421 | propagate_pure_const (void) |
cb886925 | 1422 | { |
1423 | struct cgraph_node *node; | |
1424 | struct cgraph_node *w; | |
1425 | struct cgraph_node **order = | |
35ee1c66 | 1426 | XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); |
cb886925 | 1427 | int order_pos; |
1428 | int i; | |
1429 | struct ipa_dfs_info * w_info; | |
366970c6 | 1430 | bool remove_p = false; |
aaa36a78 | 1431 | bool has_cdtor; |
cb886925 | 1432 | |
8cdb0206 | 1433 | order_pos = ipa_reduced_postorder (order, true, |
d2c6c2b4 | 1434 | ignore_edge_for_pure_const); |
f7d118a9 | 1435 | if (dump_file) |
1436 | { | |
415d1b9a | 1437 | cgraph_node::dump_cgraph (dump_file); |
48669653 | 1438 | ipa_print_order (dump_file, "reduced", order, order_pos); |
f7d118a9 | 1439 | } |
1440 | ||
9d75589a | 1441 | /* Propagate the local information through the call graph to produce |
f7d118a9 | 1442 | the global information. All the nodes within a cycle will have |
1443 | the same info so we collapse cycles first. Then we can do the | |
1444 | propagation in one pass from the leaves to the roots. */ | |
1445 | for (i = 0; i < order_pos; i++ ) | |
1446 | { | |
1447 | enum pure_const_state_e pure_const_state = IPA_CONST; | |
9c2a0c05 | 1448 | bool looping = false; |
54157bf1 | 1449 | int count = 0; |
f7d118a9 | 1450 | node = order[i]; |
1451 | ||
02774f2d | 1452 | if (node->alias) |
8c1fce46 | 1453 | continue; |
1454 | ||
fc94a528 | 1455 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1456 | fprintf (dump_file, "Starting cycle\n"); | |
1457 | ||
f7d118a9 | 1458 | /* Find the worst state for any node in the cycle. */ |
1459 | w = node; | |
023a28e1 | 1460 | while (w && pure_const_state != IPA_NEITHER) |
f7d118a9 | 1461 | { |
b5cebd44 | 1462 | struct cgraph_edge *e; |
023a28e1 | 1463 | struct cgraph_edge *ie; |
1464 | int i; | |
51ce5652 | 1465 | struct ipa_ref *ref = NULL; |
023a28e1 | 1466 | |
16f72bd0 | 1467 | funct_state w_l = funct_state_summaries->get_create (w); |
fc94a528 | 1468 | if (dump_file && (dump_flags & TDF_DETAILS)) |
0e388735 | 1469 | fprintf (dump_file, " Visiting %s state:%s looping %i\n", |
1470 | w->dump_name (), | |
fc94a528 | 1471 | pure_const_names[w_l->pure_const_state], |
1472 | w_l->looping); | |
f7d118a9 | 1473 | |
8b4ee73c | 1474 | /* First merge in function body properties. |
1475 | We are safe to pass NULL as FROM and TO because we will take care | |
1476 | of possible interposition when walking callees. */ | |
023a28e1 | 1477 | worse_state (&pure_const_state, &looping, |
8b4ee73c | 1478 | w_l->pure_const_state, w_l->looping, |
1479 | NULL, NULL); | |
023a28e1 | 1480 | if (pure_const_state == IPA_NEITHER) |
1481 | break; | |
1482 | ||
b5cebd44 | 1483 | count++; |
1484 | ||
023a28e1 | 1485 | /* We consider recursive cycles as possibly infinite. |
1486 | This might be relaxed since infinite recursion leads to stack | |
1487 | overflow. */ | |
b5cebd44 | 1488 | if (count > 1) |
1489 | looping = true; | |
48e1416a | 1490 | |
023a28e1 | 1491 | /* Now walk the edges and merge in callee properties. */ |
d2c6c2b4 | 1492 | for (e = w->callees; e && pure_const_state != IPA_NEITHER; |
1493 | e = e->next_callee) | |
f7d118a9 | 1494 | { |
b2c2e188 | 1495 | enum availability avail; |
cfd85d03 | 1496 | struct cgraph_node *y = e->callee-> |
8b4ee73c | 1497 | function_or_virtual_thunk_symbol (&avail, |
1498 | e->caller); | |
fc94a528 | 1499 | enum pure_const_state_e edge_state = IPA_CONST; |
1500 | bool edge_looping = false; | |
54157bf1 | 1501 | |
fc94a528 | 1502 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1503 | { | |
0e388735 | 1504 | fprintf (dump_file, " Call to %s", |
1505 | e->callee->dump_name ()); | |
fc94a528 | 1506 | } |
415d1b9a | 1507 | if (avail > AVAIL_INTERPOSABLE) |
f7d118a9 | 1508 | { |
d3fb548c | 1509 | funct_state y_l = funct_state_summaries->get_create (y); |
1510 | ||
fc94a528 | 1511 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1512 | { | |
1513 | fprintf (dump_file, | |
1514 | " state:%s looping:%i\n", | |
1515 | pure_const_names[y_l->pure_const_state], | |
1516 | y_l->looping); | |
1517 | } | |
4c170941 | 1518 | if (y_l->pure_const_state > IPA_PURE |
35ee1c66 | 1519 | && e->cannot_lead_to_return_p ()) |
fc94a528 | 1520 | { |
1521 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
023a28e1 | 1522 | fprintf (dump_file, |
1523 | " Ignoring side effects" | |
1524 | " -> pure, looping\n"); | |
fc94a528 | 1525 | edge_state = IPA_PURE; |
1526 | edge_looping = true; | |
1527 | } | |
1528 | else | |
1529 | { | |
1530 | edge_state = y_l->pure_const_state; | |
1531 | edge_looping = y_l->looping; | |
1532 | } | |
f7d118a9 | 1533 | } |
a53e7471 | 1534 | else if (special_builtin_state (&edge_state, &edge_looping, |
02774f2d | 1535 | y->decl)) |
7dd42908 | 1536 | ; |
ef378c27 | 1537 | else |
023a28e1 | 1538 | state_from_flags (&edge_state, &edge_looping, |
02774f2d | 1539 | flags_from_decl_or_type (y->decl), |
35ee1c66 | 1540 | e->cannot_lead_to_return_p ()); |
023a28e1 | 1541 | |
1542 | /* Merge the results with what we already know. */ | |
1543 | better_state (&edge_state, &edge_looping, | |
1544 | w_l->state_previously_known, | |
1545 | w_l->looping_previously_known); | |
1546 | worse_state (&pure_const_state, &looping, | |
8b4ee73c | 1547 | edge_state, edge_looping, e->caller, e->callee); |
023a28e1 | 1548 | if (pure_const_state == IPA_NEITHER) |
1549 | break; | |
1550 | } | |
ef378c27 | 1551 | |
023a28e1 | 1552 | /* Now process the indirect call. */ |
d2c6c2b4 | 1553 | for (ie = w->indirect_calls; |
1554 | ie && pure_const_state != IPA_NEITHER; ie = ie->next_callee) | |
023a28e1 | 1555 | { |
1556 | enum pure_const_state_e edge_state = IPA_CONST; | |
1557 | bool edge_looping = false; | |
4c170941 | 1558 | |
023a28e1 | 1559 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1560 | fprintf (dump_file, " Indirect call"); | |
1561 | state_from_flags (&edge_state, &edge_looping, | |
1562 | ie->indirect_info->ecf_flags, | |
35ee1c66 | 1563 | ie->cannot_lead_to_return_p ()); |
023a28e1 | 1564 | /* Merge the results with what we already know. */ |
1565 | better_state (&edge_state, &edge_looping, | |
1566 | w_l->state_previously_known, | |
1567 | w_l->looping_previously_known); | |
1568 | worse_state (&pure_const_state, &looping, | |
8b4ee73c | 1569 | edge_state, edge_looping, NULL, NULL); |
fc94a528 | 1570 | if (pure_const_state == IPA_NEITHER) |
1571 | break; | |
f7d118a9 | 1572 | } |
023a28e1 | 1573 | |
1574 | /* And finally all loads and stores. */ | |
d2c6c2b4 | 1575 | for (i = 0; w->iterate_reference (i, ref) |
1576 | && pure_const_state != IPA_NEITHER; i++) | |
023a28e1 | 1577 | { |
1578 | enum pure_const_state_e ref_state = IPA_CONST; | |
1579 | bool ref_looping = false; | |
1580 | switch (ref->use) | |
1581 | { | |
1582 | case IPA_REF_LOAD: | |
1583 | /* readonly reads are safe. */ | |
51ce5652 | 1584 | if (TREE_READONLY (ref->referred->decl)) |
023a28e1 | 1585 | break; |
1586 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1587 | fprintf (dump_file, " nonreadonly global var read\n"); | |
1588 | ref_state = IPA_PURE; | |
1589 | break; | |
1590 | case IPA_REF_STORE: | |
51ce5652 | 1591 | if (ref->cannot_lead_to_return ()) |
023a28e1 | 1592 | break; |
1593 | ref_state = IPA_NEITHER; | |
1594 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1595 | fprintf (dump_file, " global var write\n"); | |
1596 | break; | |
1597 | case IPA_REF_ADDR: | |
1598 | break; | |
5cb7c8cf | 1599 | default: |
1600 | gcc_unreachable (); | |
023a28e1 | 1601 | } |
1602 | better_state (&ref_state, &ref_looping, | |
1603 | w_l->state_previously_known, | |
1604 | w_l->looping_previously_known); | |
1605 | worse_state (&pure_const_state, &looping, | |
8b4ee73c | 1606 | ref_state, ref_looping, NULL, NULL); |
023a28e1 | 1607 | if (pure_const_state == IPA_NEITHER) |
1608 | break; | |
1609 | } | |
02774f2d | 1610 | w_info = (struct ipa_dfs_info *) w->aux; |
f7d118a9 | 1611 | w = w_info->next_cycle; |
1612 | } | |
fc94a528 | 1613 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1614 | fprintf (dump_file, "Result %s looping %i\n", | |
1615 | pure_const_names [pure_const_state], | |
1616 | looping); | |
f7d118a9 | 1617 | |
04c849b3 | 1618 | /* Find the worst state of can_free for any node in the cycle. */ |
1619 | bool can_free = false; | |
1620 | w = node; | |
1621 | while (w && !can_free) | |
1622 | { | |
1623 | struct cgraph_edge *e; | |
bd3c34e9 | 1624 | funct_state w_l = funct_state_summaries->get (w); |
04c849b3 | 1625 | |
1626 | if (w_l->can_free | |
1627 | || w->get_availability () == AVAIL_INTERPOSABLE | |
1628 | || w->indirect_calls) | |
1629 | can_free = true; | |
1630 | ||
1631 | for (e = w->callees; e && !can_free; e = e->next_callee) | |
1632 | { | |
1633 | enum availability avail; | |
cfd85d03 | 1634 | struct cgraph_node *y = e->callee-> |
8b4ee73c | 1635 | function_or_virtual_thunk_symbol (&avail, |
1636 | e->caller); | |
04c849b3 | 1637 | |
1638 | if (avail > AVAIL_INTERPOSABLE) | |
bd3c34e9 | 1639 | can_free = funct_state_summaries->get (y)->can_free; |
04c849b3 | 1640 | else |
1641 | can_free = true; | |
1642 | } | |
1643 | w_info = (struct ipa_dfs_info *) w->aux; | |
1644 | w = w_info->next_cycle; | |
1645 | } | |
1646 | ||
f7d118a9 | 1647 | /* Copy back the region's pure_const_state which is shared by |
1648 | all nodes in the region. */ | |
1649 | w = node; | |
1650 | while (w) | |
1651 | { | |
bd3c34e9 | 1652 | funct_state w_l = funct_state_summaries->get (w); |
b5cebd44 | 1653 | enum pure_const_state_e this_state = pure_const_state; |
1654 | bool this_looping = looping; | |
f7d118a9 | 1655 | |
04c849b3 | 1656 | w_l->can_free = can_free; |
1657 | w->nonfreeing_fn = !can_free; | |
1658 | if (!can_free && dump_file) | |
1659 | fprintf (dump_file, "Function found not to call free: %s\n", | |
1660 | w->name ()); | |
1661 | ||
df9b545b | 1662 | if (w_l->state_previously_known != IPA_NEITHER |
1663 | && this_state > w_l->state_previously_known) | |
4c170941 | 1664 | { |
1665 | this_state = w_l->state_previously_known; | |
d2c6c2b4 | 1666 | if (this_state == IPA_NEITHER) |
1667 | this_looping = w_l->looping_previously_known; | |
4c170941 | 1668 | } |
a1e88032 | 1669 | if (!this_looping && self_recursive_p (w)) |
1670 | this_looping = true; | |
df9b545b | 1671 | if (!w_l->looping_previously_known) |
1672 | this_looping = false; | |
cb886925 | 1673 | |
b5cebd44 | 1674 | /* All nodes within a cycle share the same info. */ |
1675 | w_l->pure_const_state = this_state; | |
1676 | w_l->looping = this_looping; | |
1677 | ||
ce2d198d | 1678 | /* Inline clones share declaration with their offline copies; |
1679 | do not modify their declarations since the offline copy may | |
1680 | be different. */ | |
1681 | if (!w->global.inlined_to) | |
1682 | switch (this_state) | |
1683 | { | |
1684 | case IPA_CONST: | |
1685 | if (!TREE_READONLY (w->decl)) | |
1686 | { | |
1687 | warn_function_const (w->decl, !this_looping); | |
1688 | if (dump_file) | |
1689 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
1690 | this_looping ? "looping " : "", | |
1691 | w->name ()); | |
1692 | } | |
aaa36a78 | 1693 | /* Turning constructor or destructor to non-looping const/pure |
1694 | enables us to possibly remove the function completely. */ | |
1695 | if (this_looping) | |
1696 | has_cdtor = false; | |
1697 | else | |
1698 | has_cdtor = w->call_for_symbol_and_aliases (cdtor_p, | |
1699 | NULL, true); | |
1700 | if (w->set_const_flag (true, this_looping)) | |
1701 | { | |
1702 | if (dump_file) | |
1703 | fprintf (dump_file, | |
1704 | "Declaration updated to be %sconst: %s\n", | |
1705 | this_looping ? "looping " : "", | |
1706 | w->name ()); | |
1707 | remove_p |= has_cdtor; | |
1708 | } | |
ce2d198d | 1709 | break; |
48e1416a | 1710 | |
ce2d198d | 1711 | case IPA_PURE: |
1712 | if (!DECL_PURE_P (w->decl)) | |
1713 | { | |
1714 | warn_function_pure (w->decl, !this_looping); | |
1715 | if (dump_file) | |
1716 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
1717 | this_looping ? "looping " : "", | |
1718 | w->name ()); | |
1719 | } | |
aaa36a78 | 1720 | if (this_looping) |
1721 | has_cdtor = false; | |
1722 | else | |
1723 | has_cdtor = w->call_for_symbol_and_aliases (cdtor_p, | |
1724 | NULL, true); | |
1725 | if (w->set_pure_flag (true, this_looping)) | |
1726 | { | |
1727 | if (dump_file) | |
1728 | fprintf (dump_file, | |
1729 | "Declaration updated to be %spure: %s\n", | |
1730 | this_looping ? "looping " : "", | |
1731 | w->name ()); | |
1732 | remove_p |= has_cdtor; | |
1733 | } | |
ce2d198d | 1734 | break; |
48e1416a | 1735 | |
ce2d198d | 1736 | default: |
1737 | break; | |
1738 | } | |
02774f2d | 1739 | w_info = (struct ipa_dfs_info *) w->aux; |
17b28e52 | 1740 | w = w_info->next_cycle; |
1741 | } | |
1742 | } | |
1743 | ||
7771d558 | 1744 | ipa_free_postorder_info (); |
c0240443 | 1745 | free (order); |
366970c6 | 1746 | return remove_p; |
c0240443 | 1747 | } |
1748 | ||
1749 | /* Produce transitive closure over the callgraph and compute nothrow | |
1750 | attributes. */ | |
1751 | ||
1752 | static void | |
1753 | propagate_nothrow (void) | |
1754 | { | |
1755 | struct cgraph_node *node; | |
1756 | struct cgraph_node *w; | |
1757 | struct cgraph_node **order = | |
35ee1c66 | 1758 | XCNEWVEC (struct cgraph_node *, symtab->cgraph_count); |
c0240443 | 1759 | int order_pos; |
1760 | int i; | |
1761 | struct ipa_dfs_info * w_info; | |
1762 | ||
8cdb0206 | 1763 | order_pos = ipa_reduced_postorder (order, true, |
355c1f40 | 1764 | ignore_edge_for_nothrow); |
17b28e52 | 1765 | if (dump_file) |
1766 | { | |
415d1b9a | 1767 | cgraph_node::dump_cgraph (dump_file); |
7771d558 | 1768 | ipa_print_order (dump_file, "reduced for nothrow", order, order_pos); |
17b28e52 | 1769 | } |
c0240443 | 1770 | |
9d75589a | 1771 | /* Propagate the local information through the call graph to produce |
17b28e52 | 1772 | the global information. All the nodes within a cycle will have |
1773 | the same info so we collapse cycles first. Then we can do the | |
1774 | propagation in one pass from the leaves to the roots. */ | |
1775 | for (i = 0; i < order_pos; i++ ) | |
1776 | { | |
1777 | bool can_throw = false; | |
1778 | node = order[i]; | |
1779 | ||
02774f2d | 1780 | if (node->alias) |
8c1fce46 | 1781 | continue; |
1782 | ||
17b28e52 | 1783 | /* Find the worst state for any node in the cycle. */ |
1784 | w = node; | |
b2c90c54 | 1785 | while (w && !can_throw) |
17b28e52 | 1786 | { |
023a28e1 | 1787 | struct cgraph_edge *e, *ie; |
17b28e52 | 1788 | |
355c1f40 | 1789 | if (!TREE_NOTHROW (w->decl)) |
17b28e52 | 1790 | { |
16f72bd0 | 1791 | funct_state w_l = funct_state_summaries->get_create (w); |
17b28e52 | 1792 | |
355c1f40 | 1793 | if (w_l->can_throw |
1794 | || w->get_availability () == AVAIL_INTERPOSABLE) | |
1795 | can_throw = true; | |
1796 | ||
1797 | for (e = w->callees; e && !can_throw; e = e->next_callee) | |
17b28e52 | 1798 | { |
355c1f40 | 1799 | enum availability avail; |
1800 | ||
1801 | if (!e->can_throw_external || TREE_NOTHROW (e->callee->decl)) | |
1802 | continue; | |
1803 | ||
1804 | struct cgraph_node *y = e->callee-> | |
ace7bf06 | 1805 | function_or_virtual_thunk_symbol (&avail, |
1806 | e->caller); | |
17b28e52 | 1807 | |
07c11f2b | 1808 | /* We can use info about the callee only if we know it |
1809 | cannot be interposed. | |
ace7bf06 | 1810 | When callee is compiled with non-call exceptions we also |
1811 | must check that the declaration is bound to current | |
1812 | body as other semantically equivalent body may still | |
1813 | throw. */ | |
355c1f40 | 1814 | if (avail <= AVAIL_INTERPOSABLE |
1815 | || (!TREE_NOTHROW (y->decl) | |
16f72bd0 | 1816 | && (funct_state_summaries->get_create (y)->can_throw |
ace7bf06 | 1817 | || (opt_for_fn (y->decl, flag_non_call_exceptions) |
1818 | && !e->callee->binds_to_current_def_p (w))))) | |
17b28e52 | 1819 | can_throw = true; |
1820 | } | |
355c1f40 | 1821 | for (ie = w->indirect_calls; ie && !can_throw; |
1822 | ie = ie->next_callee) | |
1823 | if (ie->can_throw_external | |
1824 | && !(ie->indirect_info->ecf_flags & ECF_NOTHROW)) | |
1825 | can_throw = true; | |
17b28e52 | 1826 | } |
02774f2d | 1827 | w_info = (struct ipa_dfs_info *) w->aux; |
17b28e52 | 1828 | w = w_info->next_cycle; |
1829 | } | |
1830 | ||
1831 | /* Copy back the region's pure_const_state which is shared by | |
1832 | all nodes in the region. */ | |
1833 | w = node; | |
1834 | while (w) | |
1835 | { | |
eb57efa5 | 1836 | funct_state w_l = funct_state_summaries->get_create (w); |
02774f2d | 1837 | if (!can_throw && !TREE_NOTHROW (w->decl)) |
b5cebd44 | 1838 | { |
ce2d198d | 1839 | /* Inline clones share declaration with their offline copies; |
1840 | do not modify their declarations since the offline copy may | |
1841 | be different. */ | |
1842 | if (!w->global.inlined_to) | |
1843 | { | |
415d1b9a | 1844 | w->set_nothrow_flag (true); |
ce2d198d | 1845 | if (dump_file) |
1846 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
1847 | w->name ()); | |
1848 | } | |
f7d118a9 | 1849 | } |
02774f2d | 1850 | else if (can_throw && !TREE_NOTHROW (w->decl)) |
ecfab407 | 1851 | w_l->can_throw = true; |
02774f2d | 1852 | w_info = (struct ipa_dfs_info *) w->aux; |
f7d118a9 | 1853 | w = w_info->next_cycle; |
1854 | } | |
1855 | } | |
1856 | ||
7771d558 | 1857 | ipa_free_postorder_info (); |
f7d118a9 | 1858 | free (order); |
c0240443 | 1859 | } |
1860 | ||
bd5ef087 | 1861 | /* Debugging function to dump state of malloc lattice. */ |
1862 | ||
1863 | DEBUG_FUNCTION | |
1864 | static void | |
1865 | dump_malloc_lattice (FILE *dump_file, const char *s) | |
1866 | { | |
1867 | if (!dump_file) | |
1868 | return; | |
1869 | ||
1870 | fprintf (dump_file, "\n\nMALLOC LATTICE %s:\n", s); | |
1871 | cgraph_node *node; | |
1872 | FOR_EACH_FUNCTION (node) | |
1873 | { | |
2c085ec2 | 1874 | funct_state fs = funct_state_summaries->get (node); |
1875 | if (fs) | |
1876 | fprintf (dump_file, "%s: %s\n", node->name (), | |
1877 | malloc_state_names[fs->malloc_state]); | |
bd5ef087 | 1878 | } |
1879 | } | |
1880 | ||
1881 | /* Propagate malloc attribute across the callgraph. */ | |
1882 | ||
1883 | static void | |
1884 | propagate_malloc (void) | |
1885 | { | |
1886 | cgraph_node *node; | |
1887 | FOR_EACH_FUNCTION (node) | |
1888 | { | |
1889 | if (DECL_IS_MALLOC (node->decl)) | |
16f72bd0 | 1890 | if (!funct_state_summaries->exists (node)) |
bd5ef087 | 1891 | { |
16f72bd0 | 1892 | funct_state fs = funct_state_summaries->get_create (node); |
1893 | fs->malloc_state = STATE_MALLOC; | |
bd5ef087 | 1894 | } |
1895 | } | |
1896 | ||
1897 | dump_malloc_lattice (dump_file, "Initial"); | |
1898 | struct cgraph_node **order | |
1899 | = XNEWVEC (struct cgraph_node *, symtab->cgraph_count); | |
1900 | int order_pos = ipa_reverse_postorder (order); | |
1901 | bool changed = true; | |
1902 | ||
1903 | while (changed) | |
1904 | { | |
1905 | changed = false; | |
1906 | /* Walk in postorder. */ | |
1907 | for (int i = order_pos - 1; i >= 0; --i) | |
1908 | { | |
1909 | cgraph_node *node = order[i]; | |
1910 | if (node->alias | |
1911 | || !node->definition | |
16f72bd0 | 1912 | || !funct_state_summaries->exists (node)) |
bd5ef087 | 1913 | continue; |
1914 | ||
2c085ec2 | 1915 | funct_state l = funct_state_summaries->get (node); |
bd5ef087 | 1916 | |
1917 | /* FIXME: add support for indirect-calls. */ | |
1918 | if (node->indirect_calls) | |
1919 | { | |
1920 | l->malloc_state = STATE_MALLOC_BOTTOM; | |
1921 | continue; | |
1922 | } | |
1923 | ||
1924 | if (node->get_availability () <= AVAIL_INTERPOSABLE) | |
1925 | { | |
1926 | l->malloc_state = STATE_MALLOC_BOTTOM; | |
1927 | continue; | |
1928 | } | |
1929 | ||
1930 | if (l->malloc_state == STATE_MALLOC_BOTTOM) | |
1931 | continue; | |
1932 | ||
1933 | vec<cgraph_node *> callees = vNULL; | |
1934 | for (cgraph_edge *cs = node->callees; cs; cs = cs->next_callee) | |
1935 | { | |
b53d4f56 | 1936 | ipa_call_summary *es = ipa_call_summaries->get_create (cs); |
bd5ef087 | 1937 | if (es && es->is_return_callee_uncaptured) |
1938 | callees.safe_push (cs->callee); | |
1939 | } | |
1940 | ||
1941 | malloc_state_e new_state = l->malloc_state; | |
1942 | for (unsigned j = 0; j < callees.length (); j++) | |
1943 | { | |
1944 | cgraph_node *callee = callees[j]; | |
16f72bd0 | 1945 | if (!funct_state_summaries->exists (node)) |
bd5ef087 | 1946 | { |
1947 | new_state = STATE_MALLOC_BOTTOM; | |
1948 | break; | |
1949 | } | |
16f72bd0 | 1950 | malloc_state_e callee_state |
1951 | = funct_state_summaries->get_create (callee)->malloc_state; | |
bd5ef087 | 1952 | if (new_state < callee_state) |
1953 | new_state = callee_state; | |
1954 | } | |
1955 | if (new_state != l->malloc_state) | |
1956 | { | |
1957 | changed = true; | |
1958 | l->malloc_state = new_state; | |
1959 | } | |
1960 | } | |
1961 | } | |
1962 | ||
1963 | FOR_EACH_DEFINED_FUNCTION (node) | |
16f72bd0 | 1964 | if (funct_state_summaries->exists (node)) |
bd5ef087 | 1965 | { |
2c085ec2 | 1966 | funct_state l = funct_state_summaries->get (node); |
bd5ef087 | 1967 | if (!node->alias |
1968 | && l->malloc_state == STATE_MALLOC | |
1969 | && !node->global.inlined_to) | |
1970 | { | |
1971 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1972 | fprintf (dump_file, "Function %s found to be malloc\n", | |
1973 | node->name ()); | |
1974 | ||
1975 | bool malloc_decl_p = DECL_IS_MALLOC (node->decl); | |
1976 | node->set_malloc_flag (true); | |
1977 | if (!malloc_decl_p && warn_suggest_attribute_malloc) | |
1978 | warn_function_malloc (node->decl); | |
1979 | } | |
1980 | } | |
1981 | ||
1982 | dump_malloc_lattice (dump_file, "after propagation"); | |
1983 | ipa_free_postorder_info (); | |
1984 | free (order); | |
1985 | } | |
c0240443 | 1986 | |
1987 | /* Produce the global information by preforming a transitive closure | |
1988 | on the local information that was produced by generate_summary. */ | |
1989 | ||
415309e2 | 1990 | unsigned int |
1991 | pass_ipa_pure_const:: | |
1992 | execute (function *) | |
c0240443 | 1993 | { |
366970c6 | 1994 | bool remove_p; |
c0240443 | 1995 | |
c0240443 | 1996 | /* Nothrow makes more function to not lead to return and improve |
1997 | later analysis. */ | |
1998 | propagate_nothrow (); | |
bd5ef087 | 1999 | propagate_malloc (); |
366970c6 | 2000 | remove_p = propagate_pure_const (); |
c0240443 | 2001 | |
16f72bd0 | 2002 | delete funct_state_summaries; |
366970c6 | 2003 | return remove_p ? TODO_remove_functions : 0; |
f7d118a9 | 2004 | } |
2005 | ||
2006 | static bool | |
2007 | gate_pure_const (void) | |
2008 | { | |
d1f68cd8 | 2009 | return flag_ipa_pure_const || in_lto_p; |
f7d118a9 | 2010 | } |
2011 | ||
415309e2 | 2012 | pass_ipa_pure_const::pass_ipa_pure_const(gcc::context *ctxt) |
2013 | : ipa_opt_pass_d(pass_data_ipa_pure_const, ctxt, | |
2014 | pure_const_generate_summary, /* generate_summary */ | |
2015 | pure_const_write_summary, /* write_summary */ | |
2016 | pure_const_read_summary, /* read_summary */ | |
2017 | NULL, /* write_optimization_summary */ | |
2018 | NULL, /* read_optimization_summary */ | |
2019 | NULL, /* stmt_fixup */ | |
2020 | 0, /* function_transform_todo_flags_start */ | |
2021 | NULL, /* function_transform */ | |
2022 | NULL), /* variable_transform */ | |
16f72bd0 | 2023 | init_p (false) {} |
cbe8bda8 | 2024 | |
2025 | ipa_opt_pass_d * | |
2026 | make_pass_ipa_pure_const (gcc::context *ctxt) | |
2027 | { | |
2028 | return new pass_ipa_pure_const (ctxt); | |
2029 | } | |
2030 | ||
2c06958d | 2031 | /* Return true if function should be skipped for local pure const analysis. */ |
b5cebd44 | 2032 | |
2c06958d | 2033 | static bool |
2034 | skip_function_for_local_pure_const (struct cgraph_node *node) | |
b5cebd44 | 2035 | { |
8b4ee73c | 2036 | /* Because we do not schedule pass_fixup_cfg over whole program after early |
2037 | optimizations we must not promote functions that are called by already | |
2038 | processed functions. */ | |
b5cebd44 | 2039 | |
2040 | if (function_called_by_processed_nodes_p ()) | |
2041 | { | |
2042 | if (dump_file) | |
2043 | fprintf (dump_file, "Function called in recursive cycle; ignoring\n"); | |
2c06958d | 2044 | return true; |
b5cebd44 | 2045 | } |
aaa36a78 | 2046 | /* Save some work and do not analyze functions which are interposable and |
2047 | do not have any non-interposable aliases. */ | |
2048 | if (node->get_availability () <= AVAIL_INTERPOSABLE | |
2049 | && !node->has_aliases_p ()) | |
b5cebd44 | 2050 | { |
2051 | if (dump_file) | |
8b4ee73c | 2052 | fprintf (dump_file, |
aaa36a78 | 2053 | "Function is interposable; not analyzing.\n"); |
2c06958d | 2054 | return true; |
b5cebd44 | 2055 | } |
2c06958d | 2056 | return false; |
2057 | } | |
2058 | ||
2059 | /* Simple local pass for pure const discovery reusing the analysis from | |
2060 | ipa_pure_const. This pass is effective when executed together with | |
2061 | other optimization passes in early optimization pass queue. */ | |
b5cebd44 | 2062 | |
7620bc82 | 2063 | namespace { |
2064 | ||
2065 | const pass_data pass_data_local_pure_const = | |
65b0537f | 2066 | { |
2067 | GIMPLE_PASS, /* type */ | |
2068 | "local-pure-const", /* name */ | |
2069 | OPTGROUP_NONE, /* optinfo_flags */ | |
65b0537f | 2070 | TV_IPA_PURE_CONST, /* tv_id */ |
2071 | 0, /* properties_required */ | |
2072 | 0, /* properties_provided */ | |
2073 | 0, /* properties_destroyed */ | |
2074 | 0, /* todo_flags_start */ | |
2075 | 0, /* todo_flags_finish */ | |
2076 | }; | |
2077 | ||
7620bc82 | 2078 | class pass_local_pure_const : public gimple_opt_pass |
65b0537f | 2079 | { |
2080 | public: | |
2081 | pass_local_pure_const (gcc::context *ctxt) | |
2082 | : gimple_opt_pass (pass_data_local_pure_const, ctxt) | |
2083 | {} | |
2084 | ||
2085 | /* opt_pass methods: */ | |
2086 | opt_pass * clone () { return new pass_local_pure_const (m_ctxt); } | |
2087 | virtual bool gate (function *) { return gate_pure_const (); } | |
2088 | virtual unsigned int execute (function *); | |
2089 | ||
2090 | }; // class pass_local_pure_const | |
2091 | ||
2092 | unsigned int | |
2093 | pass_local_pure_const::execute (function *fun) | |
2c06958d | 2094 | { |
2095 | bool changed = false; | |
2096 | funct_state l; | |
2097 | bool skip; | |
2098 | struct cgraph_node *node; | |
2099 | ||
415d1b9a | 2100 | node = cgraph_node::get (current_function_decl); |
2c06958d | 2101 | skip = skip_function_for_local_pure_const (node); |
60722a03 | 2102 | |
2c06958d | 2103 | if (!warn_suggest_attribute_const |
2104 | && !warn_suggest_attribute_pure | |
2105 | && skip) | |
2106 | return 0; | |
e0933141 | 2107 | |
ab3db708 | 2108 | l = analyze_function (node, false); |
2109 | ||
2110 | /* Do NORETURN discovery. */ | |
e0933141 | 2111 | if (!skip && !TREE_THIS_VOLATILE (current_function_decl) |
65b0537f | 2112 | && EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (fun)->preds) == 0) |
e0933141 | 2113 | { |
65b0537f | 2114 | warn_function_noreturn (fun->decl); |
e0933141 | 2115 | if (dump_file) |
65b0537f | 2116 | fprintf (dump_file, "Function found to be noreturn: %s\n", |
2117 | current_function_name ()); | |
e0933141 | 2118 | |
2119 | /* Update declaration and reduce profile to executed once. */ | |
2120 | TREE_THIS_VOLATILE (current_function_decl) = 1; | |
2121 | if (node->frequency > NODE_FREQUENCY_EXECUTED_ONCE) | |
65b0537f | 2122 | node->frequency = NODE_FREQUENCY_EXECUTED_ONCE; |
e0933141 | 2123 | |
2124 | changed = true; | |
2125 | } | |
ef378c27 | 2126 | |
b5cebd44 | 2127 | switch (l->pure_const_state) |
2128 | { | |
2129 | case IPA_CONST: | |
2130 | if (!TREE_READONLY (current_function_decl)) | |
2131 | { | |
2c06958d | 2132 | warn_function_const (current_function_decl, !l->looping); |
b5cebd44 | 2133 | if (dump_file) |
2134 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
2135 | l->looping ? "looping " : "", | |
9631926a | 2136 | current_function_name ()); |
b5cebd44 | 2137 | } |
2138 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
2139 | && !l->looping) | |
2140 | { | |
b5cebd44 | 2141 | if (dump_file) |
2142 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 2143 | current_function_name ()); |
b5cebd44 | 2144 | } |
aaa36a78 | 2145 | if (!skip && node->set_const_flag (true, l->looping)) |
2146 | { | |
2147 | if (dump_file) | |
2148 | fprintf (dump_file, "Declaration updated to be %sconst: %s\n", | |
2149 | l->looping ? "looping " : "", | |
2150 | current_function_name ()); | |
2151 | changed = true; | |
2152 | } | |
b5cebd44 | 2153 | break; |
2154 | ||
2155 | case IPA_PURE: | |
2c06958d | 2156 | if (!DECL_PURE_P (current_function_decl)) |
b5cebd44 | 2157 | { |
2c06958d | 2158 | warn_function_pure (current_function_decl, !l->looping); |
b5cebd44 | 2159 | if (dump_file) |
2160 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
2161 | l->looping ? "looping " : "", | |
9631926a | 2162 | current_function_name ()); |
b5cebd44 | 2163 | } |
2164 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
2165 | && !l->looping) | |
2166 | { | |
b5cebd44 | 2167 | if (dump_file) |
2168 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 2169 | current_function_name ()); |
b5cebd44 | 2170 | } |
aaa36a78 | 2171 | if (!skip && node->set_pure_flag (true, l->looping)) |
2172 | { | |
2173 | if (dump_file) | |
2174 | fprintf (dump_file, "Declaration updated to be %spure: %s\n", | |
2175 | l->looping ? "looping " : "", | |
2176 | current_function_name ()); | |
2177 | changed = true; | |
2178 | } | |
b5cebd44 | 2179 | break; |
2180 | ||
2181 | default: | |
2182 | break; | |
2183 | } | |
2184 | if (!l->can_throw && !TREE_NOTHROW (current_function_decl)) | |
2185 | { | |
415d1b9a | 2186 | node->set_nothrow_flag (true); |
b5cebd44 | 2187 | changed = true; |
2188 | if (dump_file) | |
2189 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
9631926a | 2190 | current_function_name ()); |
b5cebd44 | 2191 | } |
bd5ef087 | 2192 | |
2193 | if (l->malloc_state == STATE_MALLOC | |
2194 | && !DECL_IS_MALLOC (current_function_decl)) | |
2195 | { | |
2196 | node->set_malloc_flag (true); | |
2197 | if (warn_suggest_attribute_malloc) | |
2198 | warn_function_malloc (node->decl); | |
2199 | changed = true; | |
2200 | if (dump_file) | |
2201 | fprintf (dump_file, "Function found to be malloc: %s\n", | |
2202 | node->name ()); | |
2203 | } | |
2204 | ||
dd045aee | 2205 | free (l); |
b5cebd44 | 2206 | if (changed) |
2207 | return execute_fixup_cfg (); | |
2208 | else | |
2209 | return 0; | |
2210 | } | |
2211 | ||
7620bc82 | 2212 | } // anon namespace |
2213 | ||
cbe8bda8 | 2214 | gimple_opt_pass * |
2215 | make_pass_local_pure_const (gcc::context *ctxt) | |
2216 | { | |
2217 | return new pass_local_pure_const (ctxt); | |
2218 | } | |
64641360 | 2219 | |
2220 | /* Emit noreturn warnings. */ | |
2221 | ||
7620bc82 | 2222 | namespace { |
2223 | ||
2224 | const pass_data pass_data_warn_function_noreturn = | |
64641360 | 2225 | { |
2226 | GIMPLE_PASS, /* type */ | |
2227 | "*warn_function_noreturn", /* name */ | |
2228 | OPTGROUP_NONE, /* optinfo_flags */ | |
64641360 | 2229 | TV_NONE, /* tv_id */ |
2230 | PROP_cfg, /* properties_required */ | |
2231 | 0, /* properties_provided */ | |
2232 | 0, /* properties_destroyed */ | |
2233 | 0, /* todo_flags_start */ | |
2234 | 0, /* todo_flags_finish */ | |
2235 | }; | |
2236 | ||
7620bc82 | 2237 | class pass_warn_function_noreturn : public gimple_opt_pass |
64641360 | 2238 | { |
2239 | public: | |
2240 | pass_warn_function_noreturn (gcc::context *ctxt) | |
2241 | : gimple_opt_pass (pass_data_warn_function_noreturn, ctxt) | |
2242 | {} | |
2243 | ||
2244 | /* opt_pass methods: */ | |
31315c24 | 2245 | virtual bool gate (function *) { return warn_suggest_attribute_noreturn; } |
65b0537f | 2246 | virtual unsigned int execute (function *fun) |
2247 | { | |
2248 | if (!TREE_THIS_VOLATILE (current_function_decl) | |
2249 | && EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (fun)->preds) == 0) | |
2250 | warn_function_noreturn (current_function_decl); | |
2251 | return 0; | |
2252 | } | |
64641360 | 2253 | |
2254 | }; // class pass_warn_function_noreturn | |
2255 | ||
7620bc82 | 2256 | } // anon namespace |
2257 | ||
64641360 | 2258 | gimple_opt_pass * |
2259 | make_pass_warn_function_noreturn (gcc::context *ctxt) | |
2260 | { | |
2261 | return new pass_warn_function_noreturn (ctxt); | |
2262 | } | |
73594827 | 2263 | |
2264 | /* Simple local pass for pure const discovery reusing the analysis from | |
2265 | ipa_pure_const. This pass is effective when executed together with | |
2266 | other optimization passes in early optimization pass queue. */ | |
2267 | ||
7620bc82 | 2268 | namespace { |
2269 | ||
2270 | const pass_data pass_data_nothrow = | |
73594827 | 2271 | { |
2272 | GIMPLE_PASS, /* type */ | |
2273 | "nothrow", /* name */ | |
2274 | OPTGROUP_NONE, /* optinfo_flags */ | |
2275 | TV_IPA_PURE_CONST, /* tv_id */ | |
2276 | 0, /* properties_required */ | |
2277 | 0, /* properties_provided */ | |
2278 | 0, /* properties_destroyed */ | |
2279 | 0, /* todo_flags_start */ | |
2280 | 0, /* todo_flags_finish */ | |
2281 | }; | |
2282 | ||
7620bc82 | 2283 | class pass_nothrow : public gimple_opt_pass |
73594827 | 2284 | { |
2285 | public: | |
2286 | pass_nothrow (gcc::context *ctxt) | |
2287 | : gimple_opt_pass (pass_data_nothrow, ctxt) | |
2288 | {} | |
2289 | ||
2290 | /* opt_pass methods: */ | |
2291 | opt_pass * clone () { return new pass_nothrow (m_ctxt); } | |
2292 | virtual bool gate (function *) { return optimize; } | |
2293 | virtual unsigned int execute (function *); | |
2294 | ||
2295 | }; // class pass_nothrow | |
2296 | ||
2297 | unsigned int | |
2298 | pass_nothrow::execute (function *) | |
2299 | { | |
2300 | struct cgraph_node *node; | |
2301 | basic_block this_block; | |
2302 | ||
2303 | if (TREE_NOTHROW (current_function_decl)) | |
2304 | return 0; | |
2305 | ||
2306 | node = cgraph_node::get (current_function_decl); | |
2307 | ||
f4d3c071 | 2308 | /* We run during lowering, we cannot really use availability yet. */ |
73594827 | 2309 | if (cgraph_node::get (current_function_decl)->get_availability () |
2310 | <= AVAIL_INTERPOSABLE) | |
2311 | { | |
2312 | if (dump_file) | |
2313 | fprintf (dump_file, "Function is interposable;" | |
2314 | " not analyzing.\n"); | |
2315 | return true; | |
2316 | } | |
2317 | ||
2318 | FOR_EACH_BB_FN (this_block, cfun) | |
2319 | { | |
2320 | for (gimple_stmt_iterator gsi = gsi_start_bb (this_block); | |
2321 | !gsi_end_p (gsi); | |
2322 | gsi_next (&gsi)) | |
aac19106 | 2323 | if (stmt_can_throw_external (cfun, gsi_stmt (gsi))) |
73594827 | 2324 | { |
2325 | if (is_gimple_call (gsi_stmt (gsi))) | |
2326 | { | |
2327 | tree callee_t = gimple_call_fndecl (gsi_stmt (gsi)); | |
2328 | if (callee_t && recursive_call_p (current_function_decl, | |
2329 | callee_t)) | |
2330 | continue; | |
2331 | } | |
2332 | ||
2333 | if (dump_file) | |
2334 | { | |
2335 | fprintf (dump_file, "Statement can throw: "); | |
1ffa4346 | 2336 | print_gimple_stmt (dump_file, gsi_stmt (gsi), 0); |
73594827 | 2337 | } |
2338 | return 0; | |
2339 | } | |
2340 | } | |
2341 | ||
2342 | node->set_nothrow_flag (true); | |
fd499010 | 2343 | |
2344 | bool cfg_changed = false; | |
2345 | if (self_recursive_p (node)) | |
2346 | FOR_EACH_BB_FN (this_block, cfun) | |
2347 | if (gimple *g = last_stmt (this_block)) | |
2348 | if (is_gimple_call (g)) | |
2349 | { | |
2350 | tree callee_t = gimple_call_fndecl (g); | |
2351 | if (callee_t | |
2352 | && recursive_call_p (current_function_decl, callee_t) | |
2353 | && maybe_clean_eh_stmt (g) | |
2354 | && gimple_purge_dead_eh_edges (this_block)) | |
2355 | cfg_changed = true; | |
2356 | } | |
2357 | ||
73594827 | 2358 | if (dump_file) |
2359 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
2360 | current_function_name ()); | |
fd499010 | 2361 | return cfg_changed ? TODO_cleanup_cfg : 0; |
73594827 | 2362 | } |
2363 | ||
7620bc82 | 2364 | } // anon namespace |
2365 | ||
73594827 | 2366 | gimple_opt_pass * |
2367 | make_pass_nothrow (gcc::context *ctxt) | |
2368 | { | |
2369 | return new pass_nothrow (ctxt); | |
2370 | } |