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f7d118a9 | 1 | /* Callgraph based analysis of static variables. |
71e45bc2 | 2 | Copyright (C) 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012 |
7cf0dbf3 | 3 | Free Software Foundation, Inc. |
f7d118a9 | 4 | Contributed by Kenneth Zadeck <zadeck@naturalbridge.com> |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 10 | Software Foundation; either version 3, or (at your option) any later |
f7d118a9 | 11 | version. |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 19 | along with GCC; see the file COPYING3. If not see |
20 | <http://www.gnu.org/licenses/>. */ | |
f7d118a9 | 21 | |
f0b5f617 | 22 | /* This file marks functions as being either const (TREE_READONLY) or |
23 | pure (DECL_PURE_P). It can also set a variant of these that | |
24 | are allowed to loop indefinitely (DECL_LOOPING_CONST_PURE_P). | |
f7d118a9 | 25 | |
26 | This must be run after inlining decisions have been made since | |
27 | otherwise, the local sets will not contain information that is | |
28 | consistent with post inlined state. The global sets are not prone | |
29 | to this problem since they are by definition transitive. */ | |
30 | ||
31 | /* The code in this module is called by the ipa pass manager. It | |
32 | should be one of the later passes since it's information is used by | |
33 | the rest of the compilation. */ | |
34 | ||
35 | #include "config.h" | |
36 | #include "system.h" | |
37 | #include "coretypes.h" | |
38 | #include "tm.h" | |
39 | #include "tree.h" | |
40 | #include "tree-flow.h" | |
41 | #include "tree-inline.h" | |
42 | #include "tree-pass.h" | |
43 | #include "langhooks.h" | |
44 | #include "pointer-set.h" | |
45 | #include "ggc.h" | |
46 | #include "ipa-utils.h" | |
75a70cf9 | 47 | #include "gimple.h" |
f7d118a9 | 48 | #include "cgraph.h" |
f7d118a9 | 49 | #include "flags.h" |
f7d118a9 | 50 | #include "diagnostic.h" |
ce084dfc | 51 | #include "gimple-pretty-print.h" |
f7d118a9 | 52 | #include "langhooks.h" |
959fce68 | 53 | #include "target.h" |
7bfefa9d | 54 | #include "lto-streamer.h" |
2541503d | 55 | #include "data-streamer.h" |
56 | #include "tree-streamer.h" | |
c9263b6a | 57 | #include "cfgloop.h" |
58 | #include "tree-scalar-evolution.h" | |
2c06958d | 59 | #include "intl.h" |
60 | #include "opts.h" | |
f7d118a9 | 61 | |
62 | static struct pointer_set_t *visited_nodes; | |
63 | ||
64 | /* Lattice values for const and pure functions. Everything starts out | |
65 | being const, then may drop to pure and then neither depending on | |
66 | what is found. */ | |
67 | enum pure_const_state_e | |
68 | { | |
69 | IPA_CONST, | |
70 | IPA_PURE, | |
71 | IPA_NEITHER | |
72 | }; | |
73 | ||
fc94a528 | 74 | const char *pure_const_names[3] = {"const", "pure", "neither"}; |
75 | ||
cb886925 | 76 | /* Holder for the const_state. There is one of these per function |
77 | decl. */ | |
48e1416a | 78 | struct funct_state_d |
f7d118a9 | 79 | { |
cb886925 | 80 | /* See above. */ |
f7d118a9 | 81 | enum pure_const_state_e pure_const_state; |
b5cebd44 | 82 | /* What user set here; we can be always sure about this. */ |
48e1416a | 83 | enum pure_const_state_e state_previously_known; |
84 | bool looping_previously_known; | |
cb886925 | 85 | |
86 | /* True if the function could possibly infinite loop. There are a | |
87 | lot of ways that this could be determined. We are pretty | |
88 | conservative here. While it is possible to cse pure and const | |
89 | calls, it is not legal to have dce get rid of the call if there | |
90 | is a possibility that the call could infinite loop since this is | |
91 | a behavioral change. */ | |
9c2a0c05 | 92 | bool looping; |
cb886925 | 93 | |
b5cebd44 | 94 | bool can_throw; |
f7d118a9 | 95 | }; |
96 | ||
db86e424 | 97 | /* State used when we know nothing about function. */ |
98 | static struct funct_state_d varying_state | |
99 | = { IPA_NEITHER, IPA_NEITHER, true, true, true }; | |
100 | ||
101 | ||
f7d118a9 | 102 | typedef struct funct_state_d * funct_state; |
103 | ||
cb886925 | 104 | /* The storage of the funct_state is abstracted because there is the |
105 | possibility that it may be desirable to move this to the cgraph | |
48e1416a | 106 | local info. */ |
cb886925 | 107 | |
108 | /* Array, indexed by cgraph node uid, of function states. */ | |
109 | ||
f1f41a6c | 110 | static vec<funct_state> funct_state_vec; |
cb886925 | 111 | |
50828ed8 | 112 | /* Holders of ipa cgraph hooks: */ |
113 | static struct cgraph_node_hook_list *function_insertion_hook_holder; | |
86844d6c | 114 | static struct cgraph_2node_hook_list *node_duplication_hook_holder; |
115 | static struct cgraph_node_hook_list *node_removal_hook_holder; | |
cb886925 | 116 | |
2c06958d | 117 | /* Try to guess if function body will always be visible to compiler |
118 | when compiling the call and whether compiler will be able | |
119 | to propagate the information by itself. */ | |
120 | ||
121 | static bool | |
122 | function_always_visible_to_compiler_p (tree decl) | |
123 | { | |
124 | return (!TREE_PUBLIC (decl) || DECL_DECLARED_INLINE_P (decl)); | |
125 | } | |
126 | ||
127 | /* Emit suggestion about attribute ATTRIB_NAME for DECL. KNOWN_FINITE | |
128 | is true if the function is known to be finite. The diagnostic is | |
129 | controlled by OPTION. WARNED_ABOUT is a pointer_set unique for | |
130 | OPTION, this function may initialize it and it is always returned | |
131 | by the function. */ | |
132 | ||
133 | static struct pointer_set_t * | |
134 | suggest_attribute (int option, tree decl, bool known_finite, | |
135 | struct pointer_set_t *warned_about, | |
136 | const char * attrib_name) | |
137 | { | |
2c5d2e39 | 138 | if (!option_enabled (option, &global_options)) |
2c06958d | 139 | return warned_about; |
140 | if (TREE_THIS_VOLATILE (decl) | |
141 | || (known_finite && function_always_visible_to_compiler_p (decl))) | |
142 | return warned_about; | |
143 | ||
144 | if (!warned_about) | |
145 | warned_about = pointer_set_create (); | |
146 | if (pointer_set_contains (warned_about, decl)) | |
147 | return warned_about; | |
148 | pointer_set_insert (warned_about, decl); | |
149 | warning_at (DECL_SOURCE_LOCATION (decl), | |
150 | option, | |
151 | known_finite | |
152 | ? _("function might be candidate for attribute %<%s%>") | |
153 | : _("function might be candidate for attribute %<%s%>" | |
154 | " if it is known to return normally"), attrib_name); | |
155 | return warned_about; | |
156 | } | |
157 | ||
158 | /* Emit suggestion about __attribute_((pure)) for DECL. KNOWN_FINITE | |
159 | is true if the function is known to be finite. */ | |
160 | ||
161 | static void | |
162 | warn_function_pure (tree decl, bool known_finite) | |
163 | { | |
164 | static struct pointer_set_t *warned_about; | |
165 | ||
166 | warned_about | |
167 | = suggest_attribute (OPT_Wsuggest_attribute_pure, decl, | |
168 | known_finite, warned_about, "pure"); | |
169 | } | |
170 | ||
171 | /* Emit suggestion about __attribute_((const)) for DECL. KNOWN_FINITE | |
172 | is true if the function is known to be finite. */ | |
173 | ||
174 | static void | |
175 | warn_function_const (tree decl, bool known_finite) | |
176 | { | |
177 | static struct pointer_set_t *warned_about; | |
178 | warned_about | |
179 | = suggest_attribute (OPT_Wsuggest_attribute_const, decl, | |
180 | known_finite, warned_about, "const"); | |
181 | } | |
43d60d64 | 182 | |
183 | void | |
184 | warn_function_noreturn (tree decl) | |
185 | { | |
186 | static struct pointer_set_t *warned_about; | |
08c6cbd2 | 187 | if (!lang_hooks.missing_noreturn_ok_p (decl) |
188 | && targetm.warn_func_return (decl)) | |
43d60d64 | 189 | warned_about |
190 | = suggest_attribute (OPT_Wsuggest_attribute_noreturn, decl, | |
191 | true, warned_about, "noreturn"); | |
192 | } | |
9631926a | 193 | |
cb886925 | 194 | /* Init the function state. */ |
195 | ||
196 | static void | |
197 | finish_state (void) | |
198 | { | |
f1f41a6c | 199 | funct_state_vec.release (); |
cb886925 | 200 | } |
201 | ||
202 | ||
1ee39ad1 | 203 | /* Return true if we have a function state for NODE. */ |
204 | ||
205 | static inline bool | |
206 | has_function_state (struct cgraph_node *node) | |
207 | { | |
f1f41a6c | 208 | if (!funct_state_vec.exists () |
209 | || funct_state_vec.length () <= (unsigned int)node->uid) | |
1ee39ad1 | 210 | return false; |
f1f41a6c | 211 | return funct_state_vec[node->uid] != NULL; |
1ee39ad1 | 212 | } |
213 | ||
48e1416a | 214 | /* Return the function state from NODE. */ |
f7d118a9 | 215 | |
216 | static inline funct_state | |
217 | get_function_state (struct cgraph_node *node) | |
218 | { | |
f1f41a6c | 219 | if (!funct_state_vec.exists () |
220 | || funct_state_vec.length () <= (unsigned int)node->uid | |
221 | || !funct_state_vec[node->uid]) | |
1ee39ad1 | 222 | /* We might want to put correct previously_known state into varying. */ |
db86e424 | 223 | return &varying_state; |
f1f41a6c | 224 | return funct_state_vec[node->uid]; |
cb886925 | 225 | } |
226 | ||
227 | /* Set the function state S for NODE. */ | |
228 | ||
229 | static inline void | |
230 | set_function_state (struct cgraph_node *node, funct_state s) | |
231 | { | |
f1f41a6c | 232 | if (!funct_state_vec.exists () |
233 | || funct_state_vec.length () <= (unsigned int)node->uid) | |
234 | funct_state_vec.safe_grow_cleared (node->uid + 1); | |
235 | funct_state_vec[node->uid] = s; | |
f7d118a9 | 236 | } |
237 | ||
f0b5f617 | 238 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
f7d118a9 | 239 | variable T is legal in a function that is either pure or const. */ |
240 | ||
48e1416a | 241 | static inline void |
242 | check_decl (funct_state local, | |
023a28e1 | 243 | tree t, bool checking_write, bool ipa) |
f7d118a9 | 244 | { |
f7d118a9 | 245 | /* Do not want to do anything with volatile except mark any |
246 | function that uses one to be not const or pure. */ | |
48e1416a | 247 | if (TREE_THIS_VOLATILE (t)) |
248 | { | |
f7d118a9 | 249 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 250 | if (dump_file) |
251 | fprintf (dump_file, " Volatile operand is not const/pure"); | |
f7d118a9 | 252 | return; |
253 | } | |
254 | ||
255 | /* Do not care about a local automatic that is not static. */ | |
256 | if (!TREE_STATIC (t) && !DECL_EXTERNAL (t)) | |
257 | return; | |
258 | ||
b5cebd44 | 259 | /* If the variable has the "used" attribute, treat it as if it had a |
260 | been touched by the devil. */ | |
83a23b05 | 261 | if (DECL_PRESERVE_P (t)) |
b5cebd44 | 262 | { |
263 | local->pure_const_state = IPA_NEITHER; | |
264 | if (dump_file) | |
265 | fprintf (dump_file, " Used static/global variable is not const/pure\n"); | |
266 | return; | |
267 | } | |
268 | ||
023a28e1 | 269 | /* In IPA mode we are not interested in checking actual loads and stores; |
270 | they will be processed at propagation time using ipa_ref. */ | |
271 | if (ipa) | |
272 | return; | |
273 | ||
f7d118a9 | 274 | /* Since we have dealt with the locals and params cases above, if we |
275 | are CHECKING_WRITE, this cannot be a pure or constant | |
276 | function. */ | |
48e1416a | 277 | if (checking_write) |
bc17fd99 | 278 | { |
279 | local->pure_const_state = IPA_NEITHER; | |
b5cebd44 | 280 | if (dump_file) |
281 | fprintf (dump_file, " static/global memory write is not const/pure\n"); | |
bc17fd99 | 282 | return; |
283 | } | |
f7d118a9 | 284 | |
285 | if (DECL_EXTERNAL (t) || TREE_PUBLIC (t)) | |
286 | { | |
b5cebd44 | 287 | /* Readonly reads are safe. */ |
288 | if (TREE_READONLY (t) && !TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (t))) | |
289 | return; /* Read of a constant, do not change the function state. */ | |
48e1416a | 290 | else |
f7d118a9 | 291 | { |
b5cebd44 | 292 | if (dump_file) |
293 | fprintf (dump_file, " global memory read is not const\n"); | |
f7d118a9 | 294 | /* Just a regular read. */ |
295 | if (local->pure_const_state == IPA_CONST) | |
296 | local->pure_const_state = IPA_PURE; | |
297 | } | |
298 | } | |
b5cebd44 | 299 | else |
300 | { | |
301 | /* Compilation level statics can be read if they are readonly | |
302 | variables. */ | |
303 | if (TREE_READONLY (t)) | |
304 | return; | |
305 | ||
306 | if (dump_file) | |
307 | fprintf (dump_file, " static memory read is not const\n"); | |
308 | /* Just a regular read. */ | |
309 | if (local->pure_const_state == IPA_CONST) | |
310 | local->pure_const_state = IPA_PURE; | |
311 | } | |
f7d118a9 | 312 | } |
313 | ||
f7d118a9 | 314 | |
b5cebd44 | 315 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
316 | variable T is legal in a function that is either pure or const. */ | |
f7d118a9 | 317 | |
48e1416a | 318 | static inline void |
5ed0b345 | 319 | check_op (funct_state local, tree t, bool checking_write) |
f7d118a9 | 320 | { |
3ae61172 | 321 | t = get_base_address (t); |
322 | if (t && TREE_THIS_VOLATILE (t)) | |
f7d118a9 | 323 | { |
5ed0b345 | 324 | local->pure_const_state = IPA_NEITHER; |
325 | if (dump_file) | |
326 | fprintf (dump_file, " Volatile indirect ref is not const/pure\n"); | |
327 | return; | |
328 | } | |
3ae61172 | 329 | else if (t |
182cf5a9 | 330 | && (INDIRECT_REF_P (t) || TREE_CODE (t) == MEM_REF) |
3ae61172 | 331 | && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME |
332 | && !ptr_deref_may_alias_global_p (TREE_OPERAND (t, 0))) | |
333 | { | |
334 | if (dump_file) | |
335 | fprintf (dump_file, " Indirect ref to local memory is OK\n"); | |
336 | return; | |
337 | } | |
5ed0b345 | 338 | else if (checking_write) |
339 | { | |
340 | local->pure_const_state = IPA_NEITHER; | |
341 | if (dump_file) | |
342 | fprintf (dump_file, " Indirect ref write is not const/pure\n"); | |
343 | return; | |
344 | } | |
345 | else | |
346 | { | |
347 | if (dump_file) | |
348 | fprintf (dump_file, " Indirect ref read is not const\n"); | |
349 | if (local->pure_const_state == IPA_CONST) | |
350 | local->pure_const_state = IPA_PURE; | |
f7d118a9 | 351 | } |
352 | } | |
353 | ||
023a28e1 | 354 | /* compute state based on ECF FLAGS and store to STATE and LOOPING. */ |
355 | ||
356 | static void | |
357 | state_from_flags (enum pure_const_state_e *state, bool *looping, | |
358 | int flags, bool cannot_lead_to_return) | |
359 | { | |
360 | *looping = false; | |
361 | if (flags & ECF_LOOPING_CONST_OR_PURE) | |
362 | { | |
363 | *looping = true; | |
364 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
365 | fprintf (dump_file, " looping"); | |
366 | } | |
367 | if (flags & ECF_CONST) | |
368 | { | |
369 | *state = IPA_CONST; | |
370 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
371 | fprintf (dump_file, " const\n"); | |
372 | } | |
373 | else if (flags & ECF_PURE) | |
374 | { | |
375 | *state = IPA_PURE; | |
376 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
377 | fprintf (dump_file, " pure\n"); | |
378 | } | |
379 | else if (cannot_lead_to_return) | |
380 | { | |
381 | *state = IPA_PURE; | |
382 | *looping = true; | |
383 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
384 | fprintf (dump_file, " ignoring side effects->pure looping\n"); | |
385 | } | |
386 | else | |
387 | { | |
388 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
9631926a | 389 | fprintf (dump_file, " neither\n"); |
023a28e1 | 390 | *state = IPA_NEITHER; |
391 | *looping = true; | |
392 | } | |
393 | } | |
394 | ||
395 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
396 | into STATE and LOOPING better of the two variants. | |
397 | Be sure to merge looping correctly. IPA_NEITHER functions | |
398 | have looping 0 even if they don't have to return. */ | |
399 | ||
400 | static inline void | |
401 | better_state (enum pure_const_state_e *state, bool *looping, | |
402 | enum pure_const_state_e state2, bool looping2) | |
403 | { | |
404 | if (state2 < *state) | |
405 | { | |
406 | if (*state == IPA_NEITHER) | |
407 | *looping = looping2; | |
408 | else | |
409 | *looping = MIN (*looping, looping2); | |
410 | } | |
411 | else if (state2 != IPA_NEITHER) | |
412 | *looping = MIN (*looping, looping2); | |
413 | } | |
414 | ||
415 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
416 | into STATE and LOOPING worse of the two variants. */ | |
417 | ||
418 | static inline void | |
419 | worse_state (enum pure_const_state_e *state, bool *looping, | |
420 | enum pure_const_state_e state2, bool looping2) | |
421 | { | |
422 | *state = MAX (*state, state2); | |
423 | *looping = MAX (*looping, looping2); | |
424 | } | |
425 | ||
0a10fd82 | 426 | /* Recognize special cases of builtins that are by themselves not pure or const |
7dd42908 | 427 | but function using them is. */ |
428 | static bool | |
a53e7471 | 429 | special_builtin_state (enum pure_const_state_e *state, bool *looping, |
7dd42908 | 430 | tree callee) |
431 | { | |
432 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
433 | switch (DECL_FUNCTION_CODE (callee)) | |
434 | { | |
435 | case BUILT_IN_RETURN: | |
436 | case BUILT_IN_UNREACHABLE: | |
437 | case BUILT_IN_ALLOCA: | |
581bf1c2 | 438 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
7dd42908 | 439 | case BUILT_IN_STACK_SAVE: |
440 | case BUILT_IN_STACK_RESTORE: | |
441 | case BUILT_IN_EH_POINTER: | |
442 | case BUILT_IN_EH_FILTER: | |
443 | case BUILT_IN_UNWIND_RESUME: | |
444 | case BUILT_IN_CXA_END_CLEANUP: | |
445 | case BUILT_IN_EH_COPY_VALUES: | |
446 | case BUILT_IN_FRAME_ADDRESS: | |
447 | case BUILT_IN_APPLY: | |
448 | case BUILT_IN_APPLY_ARGS: | |
7dd42908 | 449 | *looping = false; |
450 | *state = IPA_CONST; | |
451 | return true; | |
452 | case BUILT_IN_PREFETCH: | |
453 | *looping = true; | |
454 | *state = IPA_CONST; | |
455 | return true; | |
456 | } | |
457 | return false; | |
458 | } | |
459 | ||
f7d118a9 | 460 | /* Check the parameters of a function call to CALL_EXPR to see if |
461 | there are any references in the parameters that are not allowed for | |
462 | pure or const functions. Also check to see if this is either an | |
463 | indirect call, a call outside the compilation unit, or has special | |
464 | attributes that may also effect the purity. The CALL_EXPR node for | |
465 | the entire call expression. */ | |
466 | ||
467 | static void | |
b5cebd44 | 468 | check_call (funct_state local, gimple call, bool ipa) |
f7d118a9 | 469 | { |
75a70cf9 | 470 | int flags = gimple_call_flags (call); |
b5cebd44 | 471 | tree callee_t = gimple_call_fndecl (call); |
b5cebd44 | 472 | bool possibly_throws = stmt_could_throw_p (call); |
473 | bool possibly_throws_externally = (possibly_throws | |
474 | && stmt_can_throw_external (call)); | |
f7d118a9 | 475 | |
b5cebd44 | 476 | if (possibly_throws) |
477 | { | |
478 | unsigned int i; | |
479 | for (i = 0; i < gimple_num_ops (call); i++) | |
480 | if (gimple_op (call, i) | |
481 | && tree_could_throw_p (gimple_op (call, i))) | |
482 | { | |
cbeb677e | 483 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 484 | { |
485 | if (dump_file) | |
486 | fprintf (dump_file, " operand can throw; looping\n"); | |
487 | local->looping = true; | |
488 | } | |
489 | if (possibly_throws_externally) | |
490 | { | |
491 | if (dump_file) | |
492 | fprintf (dump_file, " operand can throw externally\n"); | |
493 | local->can_throw = true; | |
494 | } | |
495 | } | |
496 | } | |
48e1416a | 497 | |
f7d118a9 | 498 | /* The const and pure flags are set by a variety of places in the |
499 | compiler (including here). If someone has already set the flags | |
500 | for the callee, (such as for some of the builtins) we will use | |
48e1416a | 501 | them, otherwise we will compute our own information. |
502 | ||
f7d118a9 | 503 | Const and pure functions have less clobber effects than other |
504 | functions so we process these first. Otherwise if it is a call | |
505 | outside the compilation unit or an indirect call we punt. This | |
506 | leaves local calls which will be processed by following the call | |
48e1416a | 507 | graph. */ |
f7d118a9 | 508 | if (callee_t) |
509 | { | |
7dd42908 | 510 | enum pure_const_state_e call_state; |
511 | bool call_looping; | |
512 | ||
a53e7471 | 513 | if (special_builtin_state (&call_state, &call_looping, callee_t)) |
7dd42908 | 514 | { |
515 | worse_state (&local->pure_const_state, &local->looping, | |
516 | call_state, call_looping); | |
517 | return; | |
518 | } | |
f7d118a9 | 519 | /* When bad things happen to bad functions, they cannot be const |
520 | or pure. */ | |
521 | if (setjmp_call_p (callee_t)) | |
9c2a0c05 | 522 | { |
b5cebd44 | 523 | if (dump_file) |
524 | fprintf (dump_file, " setjmp is not const/pure\n"); | |
525 | local->looping = true; | |
9c2a0c05 | 526 | local->pure_const_state = IPA_NEITHER; |
9c2a0c05 | 527 | } |
f7d118a9 | 528 | |
529 | if (DECL_BUILT_IN_CLASS (callee_t) == BUILT_IN_NORMAL) | |
530 | switch (DECL_FUNCTION_CODE (callee_t)) | |
531 | { | |
532 | case BUILT_IN_LONGJMP: | |
533 | case BUILT_IN_NONLOCAL_GOTO: | |
b5cebd44 | 534 | if (dump_file) |
535 | fprintf (dump_file, " longjmp and nonlocal goto is not const/pure\n"); | |
f7d118a9 | 536 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 537 | local->looping = true; |
f7d118a9 | 538 | break; |
539 | default: | |
540 | break; | |
541 | } | |
542 | } | |
543 | ||
b5cebd44 | 544 | /* When not in IPA mode, we can still handle self recursion. */ |
545 | if (!ipa && callee_t == current_function_decl) | |
2c06958d | 546 | { |
547 | if (dump_file) | |
548 | fprintf (dump_file, " Recursive call can loop.\n"); | |
549 | local->looping = true; | |
550 | } | |
0a10fd82 | 551 | /* Either callee is unknown or we are doing local analysis. |
ef378c27 | 552 | Look to see if there are any bits available for the callee (such as by |
553 | declaration or because it is builtin) and process solely on the basis of | |
554 | those bits. */ | |
023a28e1 | 555 | else if (!ipa) |
f7d118a9 | 556 | { |
023a28e1 | 557 | enum pure_const_state_e call_state; |
558 | bool call_looping; | |
cbeb677e | 559 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 560 | { |
561 | if (dump_file) | |
562 | fprintf (dump_file, " can throw; looping\n"); | |
563 | local->looping = true; | |
564 | } | |
565 | if (possibly_throws_externally) | |
566 | { | |
567 | if (dump_file) | |
568 | { | |
e38def9c | 569 | fprintf (dump_file, " can throw externally to lp %i\n", |
570 | lookup_stmt_eh_lp (call)); | |
b5cebd44 | 571 | if (callee_t) |
572 | fprintf (dump_file, " callee:%s\n", | |
573 | IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (callee_t))); | |
574 | } | |
575 | local->can_throw = true; | |
576 | } | |
023a28e1 | 577 | if (dump_file && (dump_flags & TDF_DETAILS)) |
578 | fprintf (dump_file, " checking flags for call:"); | |
579 | state_from_flags (&call_state, &call_looping, flags, | |
580 | ((flags & (ECF_NORETURN | ECF_NOTHROW)) | |
581 | == (ECF_NORETURN | ECF_NOTHROW)) | |
582 | || (!flag_exceptions && (flags & ECF_NORETURN))); | |
583 | worse_state (&local->pure_const_state, &local->looping, | |
584 | call_state, call_looping); | |
f7d118a9 | 585 | } |
b5cebd44 | 586 | /* Direct functions calls are handled by IPA propagation. */ |
f7d118a9 | 587 | } |
588 | ||
023a28e1 | 589 | /* Wrapper around check_decl for loads in local more. */ |
5ed0b345 | 590 | |
591 | static bool | |
592 | check_load (gimple stmt ATTRIBUTE_UNUSED, tree op, void *data) | |
593 | { | |
594 | if (DECL_P (op)) | |
023a28e1 | 595 | check_decl ((funct_state)data, op, false, false); |
5ed0b345 | 596 | else |
597 | check_op ((funct_state)data, op, false); | |
598 | return false; | |
599 | } | |
600 | ||
023a28e1 | 601 | /* Wrapper around check_decl for stores in local more. */ |
5ed0b345 | 602 | |
603 | static bool | |
604 | check_store (gimple stmt ATTRIBUTE_UNUSED, tree op, void *data) | |
605 | { | |
606 | if (DECL_P (op)) | |
023a28e1 | 607 | check_decl ((funct_state)data, op, true, false); |
608 | else | |
609 | check_op ((funct_state)data, op, true); | |
610 | return false; | |
611 | } | |
612 | ||
613 | /* Wrapper around check_decl for loads in ipa mode. */ | |
614 | ||
615 | static bool | |
616 | check_ipa_load (gimple stmt ATTRIBUTE_UNUSED, tree op, void *data) | |
617 | { | |
618 | if (DECL_P (op)) | |
619 | check_decl ((funct_state)data, op, false, true); | |
620 | else | |
621 | check_op ((funct_state)data, op, false); | |
622 | return false; | |
623 | } | |
624 | ||
625 | /* Wrapper around check_decl for stores in ipa mode. */ | |
626 | ||
627 | static bool | |
628 | check_ipa_store (gimple stmt ATTRIBUTE_UNUSED, tree op, void *data) | |
629 | { | |
630 | if (DECL_P (op)) | |
631 | check_decl ((funct_state)data, op, true, true); | |
5ed0b345 | 632 | else |
633 | check_op ((funct_state)data, op, true); | |
634 | return false; | |
635 | } | |
636 | ||
dd277d48 | 637 | /* Look into pointer pointed to by GSIP and figure out what interesting side |
638 | effects it has. */ | |
b5cebd44 | 639 | static void |
640 | check_stmt (gimple_stmt_iterator *gsip, funct_state local, bool ipa) | |
f7d118a9 | 641 | { |
b5cebd44 | 642 | gimple stmt = gsi_stmt (*gsip); |
f7d118a9 | 643 | |
9845d120 | 644 | if (is_gimple_debug (stmt)) |
645 | return; | |
646 | ||
b5cebd44 | 647 | if (dump_file) |
f7d118a9 | 648 | { |
b5cebd44 | 649 | fprintf (dump_file, " scanning: "); |
650 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
651 | } | |
dd277d48 | 652 | |
541c6dbb | 653 | if (gimple_has_volatile_ops (stmt) |
654 | && !gimple_clobber_p (stmt)) | |
4b68df2e | 655 | { |
656 | local->pure_const_state = IPA_NEITHER; | |
657 | if (dump_file) | |
658 | fprintf (dump_file, " Volatile stmt is not const/pure\n"); | |
659 | } | |
660 | ||
5ed0b345 | 661 | /* Look for loads and stores. */ |
023a28e1 | 662 | walk_stmt_load_store_ops (stmt, local, |
663 | ipa ? check_ipa_load : check_load, | |
664 | ipa ? check_ipa_store : check_store); | |
b5cebd44 | 665 | |
666 | if (gimple_code (stmt) != GIMPLE_CALL | |
667 | && stmt_could_throw_p (stmt)) | |
668 | { | |
cbeb677e | 669 | if (cfun->can_throw_non_call_exceptions) |
b5cebd44 | 670 | { |
671 | if (dump_file) | |
10f4615f | 672 | fprintf (dump_file, " can throw; looping\n"); |
b5cebd44 | 673 | local->looping = true; |
674 | } | |
675 | if (stmt_can_throw_external (stmt)) | |
676 | { | |
677 | if (dump_file) | |
10f4615f | 678 | fprintf (dump_file, " can throw externally\n"); |
b5cebd44 | 679 | local->can_throw = true; |
680 | } | |
10f4615f | 681 | else |
682 | if (dump_file) | |
683 | fprintf (dump_file, " can throw\n"); | |
75a70cf9 | 684 | } |
75a70cf9 | 685 | switch (gimple_code (stmt)) |
686 | { | |
b5cebd44 | 687 | case GIMPLE_CALL: |
b5cebd44 | 688 | check_call (local, stmt, ipa); |
f7d118a9 | 689 | break; |
75a70cf9 | 690 | case GIMPLE_LABEL: |
691 | if (DECL_NONLOCAL (gimple_label_label (stmt))) | |
f7d118a9 | 692 | /* Target of long jump. */ |
9c2a0c05 | 693 | { |
b5cebd44 | 694 | if (dump_file) |
10f4615f | 695 | fprintf (dump_file, " nonlocal label is not const/pure\n"); |
9c2a0c05 | 696 | local->pure_const_state = IPA_NEITHER; |
9c2a0c05 | 697 | } |
f7d118a9 | 698 | break; |
75a70cf9 | 699 | case GIMPLE_ASM: |
97cf41ec | 700 | if (gimple_asm_clobbers_memory_p (stmt)) |
b5cebd44 | 701 | { |
97cf41ec | 702 | if (dump_file) |
10f4615f | 703 | fprintf (dump_file, " memory asm clobber is not const/pure\n"); |
97cf41ec | 704 | /* Abandon all hope, ye who enter here. */ |
705 | local->pure_const_state = IPA_NEITHER; | |
b5cebd44 | 706 | } |
707 | if (gimple_asm_volatile_p (stmt)) | |
708 | { | |
709 | if (dump_file) | |
10f4615f | 710 | fprintf (dump_file, " volatile is not const/pure\n"); |
b5cebd44 | 711 | /* Abandon all hope, ye who enter here. */ |
712 | local->pure_const_state = IPA_NEITHER; | |
713 | local->looping = true; | |
714 | } | |
715 | return; | |
f7d118a9 | 716 | default: |
717 | break; | |
718 | } | |
f7d118a9 | 719 | } |
720 | ||
cb886925 | 721 | |
f7d118a9 | 722 | /* This is the main routine for finding the reference patterns for |
723 | global variables within a function FN. */ | |
724 | ||
b5cebd44 | 725 | static funct_state |
726 | analyze_function (struct cgraph_node *fn, bool ipa) | |
f7d118a9 | 727 | { |
7d0d0ce1 | 728 | tree decl = fn->symbol.decl; |
b5cebd44 | 729 | funct_state l; |
730 | basic_block this_block; | |
f7d118a9 | 731 | |
b5cebd44 | 732 | l = XCNEW (struct funct_state_d); |
733 | l->pure_const_state = IPA_CONST; | |
df9b545b | 734 | l->state_previously_known = IPA_NEITHER; |
735 | l->looping_previously_known = true; | |
b5cebd44 | 736 | l->looping = false; |
737 | l->can_throw = false; | |
91bf9d9a | 738 | state_from_flags (&l->state_previously_known, &l->looping_previously_known, |
7d0d0ce1 | 739 | flags_from_decl_or_type (fn->symbol.decl), |
91bf9d9a | 740 | cgraph_node_cannot_return (fn)); |
741 | ||
b2c2e188 | 742 | if (fn->thunk.thunk_p || fn->alias) |
91bf9d9a | 743 | { |
744 | /* Thunk gets propagated through, so nothing interesting happens. */ | |
745 | gcc_assert (ipa); | |
746 | return l; | |
747 | } | |
f7d118a9 | 748 | |
749 | if (dump_file) | |
750 | { | |
48e1416a | 751 | fprintf (dump_file, "\n\n local analysis of %s\n ", |
b5cebd44 | 752 | cgraph_node_name (fn)); |
f7d118a9 | 753 | } |
48e1416a | 754 | |
b5cebd44 | 755 | push_cfun (DECL_STRUCT_FUNCTION (decl)); |
48e1416a | 756 | |
b5cebd44 | 757 | FOR_EACH_BB (this_block) |
f7d118a9 | 758 | { |
b5cebd44 | 759 | gimple_stmt_iterator gsi; |
760 | struct walk_stmt_info wi; | |
f7d118a9 | 761 | |
b5cebd44 | 762 | memset (&wi, 0, sizeof(wi)); |
763 | for (gsi = gsi_start_bb (this_block); | |
764 | !gsi_end_p (gsi); | |
765 | gsi_next (&gsi)) | |
f7d118a9 | 766 | { |
b5cebd44 | 767 | check_stmt (&gsi, l, ipa); |
768 | if (l->pure_const_state == IPA_NEITHER && l->looping && l->can_throw) | |
769 | goto end; | |
f7d118a9 | 770 | } |
771 | } | |
dcccac3e | 772 | |
773 | end: | |
b5cebd44 | 774 | if (l->pure_const_state != IPA_NEITHER) |
775 | { | |
776 | /* Const functions cannot have back edges (an | |
777 | indication of possible infinite loop side | |
778 | effect. */ | |
779 | if (mark_dfs_back_edges ()) | |
c9263b6a | 780 | { |
b1887855 | 781 | /* Preheaders are needed for SCEV to work. |
0a10fd82 | 782 | Simple latches and recorded exits improve chances that loop will |
b1887855 | 783 | proved to be finite in testcases such as in loop-15.c and loop-24.c */ |
784 | loop_optimizer_init (LOOPS_NORMAL | |
785 | | LOOPS_HAVE_RECORDED_EXITS); | |
c9263b6a | 786 | if (dump_file && (dump_flags & TDF_DETAILS)) |
787 | flow_loops_dump (dump_file, NULL, 0); | |
788 | if (mark_irreducible_loops ()) | |
789 | { | |
790 | if (dump_file) | |
791 | fprintf (dump_file, " has irreducible loops\n"); | |
792 | l->looping = true; | |
793 | } | |
48e1416a | 794 | else |
c9263b6a | 795 | { |
796 | loop_iterator li; | |
797 | struct loop *loop; | |
798 | scev_initialize (); | |
799 | FOR_EACH_LOOP (li, loop, 0) | |
800 | if (!finite_loop_p (loop)) | |
801 | { | |
802 | if (dump_file) | |
803 | fprintf (dump_file, " can not prove finiteness of loop %i\n", loop->num); | |
804 | l->looping =true; | |
83b709f2 | 805 | FOR_EACH_LOOP_BREAK (li); |
c9263b6a | 806 | } |
807 | scev_finalize (); | |
808 | } | |
809 | loop_optimizer_finalize (); | |
810 | } | |
b5cebd44 | 811 | } |
812 | ||
023a28e1 | 813 | if (dump_file && (dump_flags & TDF_DETAILS)) |
814 | fprintf (dump_file, " checking previously known:"); | |
023a28e1 | 815 | |
816 | better_state (&l->pure_const_state, &l->looping, | |
817 | l->state_previously_known, | |
818 | l->looping_previously_known); | |
b5cebd44 | 819 | if (TREE_NOTHROW (decl)) |
820 | l->can_throw = false; | |
821 | ||
822 | pop_cfun (); | |
dcccac3e | 823 | if (dump_file) |
824 | { | |
b5cebd44 | 825 | if (l->looping) |
826 | fprintf (dump_file, "Function is locally looping.\n"); | |
827 | if (l->can_throw) | |
828 | fprintf (dump_file, "Function is locally throwing.\n"); | |
829 | if (l->pure_const_state == IPA_CONST) | |
830 | fprintf (dump_file, "Function is locally const.\n"); | |
831 | if (l->pure_const_state == IPA_PURE) | |
832 | fprintf (dump_file, "Function is locally pure.\n"); | |
dcccac3e | 833 | } |
b5cebd44 | 834 | return l; |
f7d118a9 | 835 | } |
836 | ||
50828ed8 | 837 | /* Called when new function is inserted to callgraph late. */ |
838 | static void | |
839 | add_new_function (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED) | |
840 | { | |
ef378c27 | 841 | if (cgraph_function_body_availability (node) < AVAIL_OVERWRITABLE) |
86844d6c | 842 | return; |
50828ed8 | 843 | /* There are some shared nodes, in particular the initializers on |
844 | static declarations. We do not need to scan them more than once | |
845 | since all we would be interested in are the addressof | |
846 | operations. */ | |
847 | visited_nodes = pointer_set_create (); | |
2c06958d | 848 | if (cgraph_function_body_availability (node) > AVAIL_OVERWRITABLE) |
849 | set_function_state (node, analyze_function (node, true)); | |
50828ed8 | 850 | pointer_set_destroy (visited_nodes); |
851 | visited_nodes = NULL; | |
852 | } | |
853 | ||
86844d6c | 854 | /* Called when new clone is inserted to callgraph late. */ |
855 | ||
856 | static void | |
857 | duplicate_node_data (struct cgraph_node *src, struct cgraph_node *dst, | |
858 | void *data ATTRIBUTE_UNUSED) | |
859 | { | |
1ee39ad1 | 860 | if (has_function_state (src)) |
86844d6c | 861 | { |
862 | funct_state l = XNEW (struct funct_state_d); | |
1ee39ad1 | 863 | gcc_assert (!has_function_state (dst)); |
86844d6c | 864 | memcpy (l, get_function_state (src), sizeof (*l)); |
865 | set_function_state (dst, l); | |
866 | } | |
867 | } | |
868 | ||
869 | /* Called when new clone is inserted to callgraph late. */ | |
870 | ||
871 | static void | |
872 | remove_node_data (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED) | |
873 | { | |
1ee39ad1 | 874 | if (has_function_state (node)) |
86844d6c | 875 | { |
db86e424 | 876 | funct_state l = get_function_state (node); |
877 | if (l != &varying_state) | |
878 | free (l); | |
86844d6c | 879 | set_function_state (node, NULL); |
880 | } | |
881 | } | |
882 | ||
f7d118a9 | 883 | \f |
7bfefa9d | 884 | static void |
885 | register_hooks (void) | |
f7d118a9 | 886 | { |
7bfefa9d | 887 | static bool init_p = false; |
888 | ||
889 | if (init_p) | |
890 | return; | |
891 | ||
892 | init_p = true; | |
f7d118a9 | 893 | |
86844d6c | 894 | node_removal_hook_holder = |
895 | cgraph_add_node_removal_hook (&remove_node_data, NULL); | |
896 | node_duplication_hook_holder = | |
897 | cgraph_add_node_duplication_hook (&duplicate_node_data, NULL); | |
50828ed8 | 898 | function_insertion_hook_holder = |
899 | cgraph_add_function_insertion_hook (&add_new_function, NULL); | |
7bfefa9d | 900 | } |
901 | ||
902 | ||
903 | /* Analyze each function in the cgraph to see if it is locally PURE or | |
904 | CONST. */ | |
905 | ||
48e1416a | 906 | static void |
7bfefa9d | 907 | generate_summary (void) |
908 | { | |
909 | struct cgraph_node *node; | |
910 | ||
911 | register_hooks (); | |
912 | ||
f7d118a9 | 913 | /* There are some shared nodes, in particular the initializers on |
914 | static declarations. We do not need to scan them more than once | |
915 | since all we would be interested in are the addressof | |
916 | operations. */ | |
917 | visited_nodes = pointer_set_create (); | |
918 | ||
48e1416a | 919 | /* Process all of the functions. |
f7d118a9 | 920 | |
ef378c27 | 921 | We process AVAIL_OVERWRITABLE functions. We can not use the results |
922 | by default, but the info can be used at LTO with -fwhole-program or | |
0a10fd82 | 923 | when function got cloned and the clone is AVAILABLE. */ |
ef378c27 | 924 | |
7c455d87 | 925 | FOR_EACH_DEFINED_FUNCTION (node) |
ef378c27 | 926 | if (cgraph_function_body_availability (node) >= AVAIL_OVERWRITABLE) |
b5cebd44 | 927 | set_function_state (node, analyze_function (node, true)); |
f7d118a9 | 928 | |
929 | pointer_set_destroy (visited_nodes); | |
930 | visited_nodes = NULL; | |
cb886925 | 931 | } |
932 | ||
7bfefa9d | 933 | |
934 | /* Serialize the ipa info for lto. */ | |
935 | ||
936 | static void | |
eab36a5a | 937 | pure_const_write_summary (void) |
7bfefa9d | 938 | { |
939 | struct cgraph_node *node; | |
940 | struct lto_simple_output_block *ob | |
941 | = lto_create_simple_output_block (LTO_section_ipa_pure_const); | |
942 | unsigned int count = 0; | |
eab36a5a | 943 | lto_symtab_encoder_iterator lsei; |
944 | lto_symtab_encoder_t encoder; | |
7bfefa9d | 945 | |
eab36a5a | 946 | encoder = lto_get_out_decl_state ()->symtab_node_encoder; |
947 | ||
948 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); | |
949 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 950 | { |
eab36a5a | 951 | node = lsei_cgraph_node (lsei); |
1ee39ad1 | 952 | if (node->analyzed && has_function_state (node)) |
7bfefa9d | 953 | count++; |
954 | } | |
48e1416a | 955 | |
7f385784 | 956 | streamer_write_uhwi_stream (ob->main_stream, count); |
48e1416a | 957 | |
7bfefa9d | 958 | /* Process all of the functions. */ |
eab36a5a | 959 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); |
960 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 961 | { |
eab36a5a | 962 | node = lsei_cgraph_node (lsei); |
1ee39ad1 | 963 | if (node->analyzed && has_function_state (node)) |
7bfefa9d | 964 | { |
30baba90 | 965 | struct bitpack_d bp; |
7bfefa9d | 966 | funct_state fs; |
967 | int node_ref; | |
70225339 | 968 | lto_symtab_encoder_t encoder; |
48e1416a | 969 | |
7bfefa9d | 970 | fs = get_function_state (node); |
971 | ||
70225339 | 972 | encoder = ob->decl_state->symtab_node_encoder; |
973 | node_ref = lto_symtab_encoder_encode (encoder, (symtab_node)node); | |
7f385784 | 974 | streamer_write_uhwi_stream (ob->main_stream, node_ref); |
48e1416a | 975 | |
7bfefa9d | 976 | /* Note that flags will need to be read in the opposite |
977 | order as we are pushing the bitflags into FLAGS. */ | |
30baba90 | 978 | bp = bitpack_create (ob->main_stream); |
979 | bp_pack_value (&bp, fs->pure_const_state, 2); | |
980 | bp_pack_value (&bp, fs->state_previously_known, 2); | |
981 | bp_pack_value (&bp, fs->looping_previously_known, 1); | |
982 | bp_pack_value (&bp, fs->looping, 1); | |
983 | bp_pack_value (&bp, fs->can_throw, 1); | |
7f385784 | 984 | streamer_write_bitpack (&bp); |
7bfefa9d | 985 | } |
986 | } | |
987 | ||
988 | lto_destroy_simple_output_block (ob); | |
989 | } | |
990 | ||
991 | ||
992 | /* Deserialize the ipa info for lto. */ | |
993 | ||
48e1416a | 994 | static void |
7bfefa9d | 995 | pure_const_read_summary (void) |
996 | { | |
997 | struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); | |
998 | struct lto_file_decl_data *file_data; | |
999 | unsigned int j = 0; | |
1000 | ||
1001 | register_hooks (); | |
1002 | while ((file_data = file_data_vec[j++])) | |
1003 | { | |
1004 | const char *data; | |
1005 | size_t len; | |
1006 | struct lto_input_block *ib | |
48e1416a | 1007 | = lto_create_simple_input_block (file_data, |
1008 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1009 | &data, &len); |
1010 | if (ib) | |
1011 | { | |
1012 | unsigned int i; | |
7f385784 | 1013 | unsigned int count = streamer_read_uhwi (ib); |
7bfefa9d | 1014 | |
1015 | for (i = 0; i < count; i++) | |
1016 | { | |
1017 | unsigned int index; | |
1018 | struct cgraph_node *node; | |
30baba90 | 1019 | struct bitpack_d bp; |
7bfefa9d | 1020 | funct_state fs; |
70225339 | 1021 | lto_symtab_encoder_t encoder; |
7bfefa9d | 1022 | |
1023 | fs = XCNEW (struct funct_state_d); | |
7f385784 | 1024 | index = streamer_read_uhwi (ib); |
70225339 | 1025 | encoder = file_data->symtab_node_encoder; |
1026 | node = cgraph (lto_symtab_encoder_deref (encoder, index)); | |
7bfefa9d | 1027 | set_function_state (node, fs); |
1028 | ||
1029 | /* Note that the flags must be read in the opposite | |
1030 | order in which they were written (the bitflags were | |
1031 | pushed into FLAGS). */ | |
7f385784 | 1032 | bp = streamer_read_bitpack (ib); |
7bfefa9d | 1033 | fs->pure_const_state |
30baba90 | 1034 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
7bfefa9d | 1035 | fs->state_previously_known |
30baba90 | 1036 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
1037 | fs->looping_previously_known = bp_unpack_value (&bp, 1); | |
1038 | fs->looping = bp_unpack_value (&bp, 1); | |
1039 | fs->can_throw = bp_unpack_value (&bp, 1); | |
fc94a528 | 1040 | if (dump_file) |
1041 | { | |
7d0d0ce1 | 1042 | int flags = flags_from_decl_or_type (node->symbol.decl); |
fc94a528 | 1043 | fprintf (dump_file, "Read info for %s/%i ", |
1044 | cgraph_node_name (node), | |
1045 | node->uid); | |
1046 | if (flags & ECF_CONST) | |
1047 | fprintf (dump_file, " const"); | |
1048 | if (flags & ECF_PURE) | |
1049 | fprintf (dump_file, " pure"); | |
1050 | if (flags & ECF_NOTHROW) | |
1051 | fprintf (dump_file, " nothrow"); | |
1052 | fprintf (dump_file, "\n pure const state: %s\n", | |
1053 | pure_const_names[fs->pure_const_state]); | |
1054 | fprintf (dump_file, " previously known state: %s\n", | |
1055 | pure_const_names[fs->looping_previously_known]); | |
1056 | if (fs->looping) | |
1057 | fprintf (dump_file," function is locally looping\n"); | |
1058 | if (fs->looping_previously_known) | |
1059 | fprintf (dump_file," function is previously known looping\n"); | |
1060 | if (fs->can_throw) | |
1061 | fprintf (dump_file," function is locally throwing\n"); | |
1062 | } | |
7bfefa9d | 1063 | } |
1064 | ||
48e1416a | 1065 | lto_destroy_simple_input_block (file_data, |
1066 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1067 | ib, data, len); |
1068 | } | |
1069 | } | |
1070 | } | |
1071 | ||
1072 | ||
17b28e52 | 1073 | static bool |
1074 | ignore_edge (struct cgraph_edge *e) | |
1075 | { | |
1076 | return (!e->can_throw_external); | |
1077 | } | |
1078 | ||
b2c2e188 | 1079 | /* Return true if NODE is self recursive function. |
1080 | ??? self recursive and indirectly recursive funcions should | |
1081 | be the same, so this function seems unnecesary. */ | |
a1e88032 | 1082 | |
1083 | static bool | |
1084 | self_recursive_p (struct cgraph_node *node) | |
1085 | { | |
1086 | struct cgraph_edge *e; | |
1087 | for (e = node->callees; e; e = e->next_callee) | |
b2c2e188 | 1088 | if (cgraph_function_node (e->callee, NULL) == node) |
a1e88032 | 1089 | return true; |
1090 | return false; | |
1091 | } | |
1092 | ||
c0240443 | 1093 | /* Produce transitive closure over the callgraph and compute pure/const |
1094 | attributes. */ | |
023a28e1 | 1095 | |
c0240443 | 1096 | static void |
1097 | propagate_pure_const (void) | |
cb886925 | 1098 | { |
1099 | struct cgraph_node *node; | |
1100 | struct cgraph_node *w; | |
1101 | struct cgraph_node **order = | |
1102 | XCNEWVEC (struct cgraph_node *, cgraph_n_nodes); | |
1103 | int order_pos; | |
1104 | int i; | |
1105 | struct ipa_dfs_info * w_info; | |
1106 | ||
7771d558 | 1107 | order_pos = ipa_reduced_postorder (order, true, false, NULL); |
f7d118a9 | 1108 | if (dump_file) |
1109 | { | |
1110 | dump_cgraph (dump_file); | |
7771d558 | 1111 | ipa_print_order(dump_file, "reduced", order, order_pos); |
f7d118a9 | 1112 | } |
1113 | ||
9d75589a | 1114 | /* Propagate the local information through the call graph to produce |
f7d118a9 | 1115 | the global information. All the nodes within a cycle will have |
1116 | the same info so we collapse cycles first. Then we can do the | |
1117 | propagation in one pass from the leaves to the roots. */ | |
1118 | for (i = 0; i < order_pos; i++ ) | |
1119 | { | |
1120 | enum pure_const_state_e pure_const_state = IPA_CONST; | |
9c2a0c05 | 1121 | bool looping = false; |
54157bf1 | 1122 | int count = 0; |
f7d118a9 | 1123 | node = order[i]; |
1124 | ||
8c1fce46 | 1125 | if (node->alias) |
1126 | continue; | |
1127 | ||
fc94a528 | 1128 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1129 | fprintf (dump_file, "Starting cycle\n"); | |
1130 | ||
f7d118a9 | 1131 | /* Find the worst state for any node in the cycle. */ |
1132 | w = node; | |
023a28e1 | 1133 | while (w && pure_const_state != IPA_NEITHER) |
f7d118a9 | 1134 | { |
b5cebd44 | 1135 | struct cgraph_edge *e; |
023a28e1 | 1136 | struct cgraph_edge *ie; |
1137 | int i; | |
1138 | struct ipa_ref *ref; | |
1139 | ||
f7d118a9 | 1140 | funct_state w_l = get_function_state (w); |
fc94a528 | 1141 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1142 | fprintf (dump_file, " Visiting %s/%i state:%s looping %i\n", | |
1143 | cgraph_node_name (w), | |
1144 | w->uid, | |
1145 | pure_const_names[w_l->pure_const_state], | |
1146 | w_l->looping); | |
f7d118a9 | 1147 | |
023a28e1 | 1148 | /* First merge in function body properties. */ |
1149 | worse_state (&pure_const_state, &looping, | |
1150 | w_l->pure_const_state, w_l->looping); | |
1151 | if (pure_const_state == IPA_NEITHER) | |
1152 | break; | |
1153 | ||
1154 | /* For overwritable nodes we can not assume anything. */ | |
ef378c27 | 1155 | if (cgraph_function_body_availability (w) == AVAIL_OVERWRITABLE) |
1156 | { | |
023a28e1 | 1157 | worse_state (&pure_const_state, &looping, |
1158 | w_l->state_previously_known, | |
1159 | w_l->looping_previously_known); | |
fc94a528 | 1160 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1161 | { | |
1162 | fprintf (dump_file, | |
1163 | " Overwritable. state %s looping %i\n", | |
1164 | pure_const_names[w_l->state_previously_known], | |
1165 | w_l->looping_previously_known); | |
1166 | } | |
023a28e1 | 1167 | break; |
ef378c27 | 1168 | } |
9c2a0c05 | 1169 | |
b5cebd44 | 1170 | count++; |
1171 | ||
023a28e1 | 1172 | /* We consider recursive cycles as possibly infinite. |
1173 | This might be relaxed since infinite recursion leads to stack | |
1174 | overflow. */ | |
b5cebd44 | 1175 | if (count > 1) |
1176 | looping = true; | |
48e1416a | 1177 | |
023a28e1 | 1178 | /* Now walk the edges and merge in callee properties. */ |
48e1416a | 1179 | for (e = w->callees; e; e = e->next_callee) |
f7d118a9 | 1180 | { |
b2c2e188 | 1181 | enum availability avail; |
1182 | struct cgraph_node *y = cgraph_function_node (e->callee, &avail); | |
fc94a528 | 1183 | enum pure_const_state_e edge_state = IPA_CONST; |
1184 | bool edge_looping = false; | |
54157bf1 | 1185 | |
fc94a528 | 1186 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1187 | { | |
1188 | fprintf (dump_file, | |
1189 | " Call to %s/%i", | |
1190 | cgraph_node_name (e->callee), | |
1191 | e->callee->uid); | |
1192 | } | |
b2c2e188 | 1193 | if (avail > AVAIL_OVERWRITABLE) |
f7d118a9 | 1194 | { |
b5cebd44 | 1195 | funct_state y_l = get_function_state (y); |
fc94a528 | 1196 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1197 | { | |
1198 | fprintf (dump_file, | |
1199 | " state:%s looping:%i\n", | |
1200 | pure_const_names[y_l->pure_const_state], | |
1201 | y_l->looping); | |
1202 | } | |
4c170941 | 1203 | if (y_l->pure_const_state > IPA_PURE |
1ee39ad1 | 1204 | && cgraph_edge_cannot_lead_to_return (e)) |
fc94a528 | 1205 | { |
1206 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
023a28e1 | 1207 | fprintf (dump_file, |
1208 | " Ignoring side effects" | |
1209 | " -> pure, looping\n"); | |
fc94a528 | 1210 | edge_state = IPA_PURE; |
1211 | edge_looping = true; | |
1212 | } | |
1213 | else | |
1214 | { | |
1215 | edge_state = y_l->pure_const_state; | |
1216 | edge_looping = y_l->looping; | |
1217 | } | |
f7d118a9 | 1218 | } |
a53e7471 | 1219 | else if (special_builtin_state (&edge_state, &edge_looping, |
7d0d0ce1 | 1220 | y->symbol.decl)) |
7dd42908 | 1221 | ; |
ef378c27 | 1222 | else |
023a28e1 | 1223 | state_from_flags (&edge_state, &edge_looping, |
7d0d0ce1 | 1224 | flags_from_decl_or_type (y->symbol.decl), |
7dd42908 | 1225 | cgraph_edge_cannot_lead_to_return (e)); |
023a28e1 | 1226 | |
1227 | /* Merge the results with what we already know. */ | |
1228 | better_state (&edge_state, &edge_looping, | |
1229 | w_l->state_previously_known, | |
1230 | w_l->looping_previously_known); | |
1231 | worse_state (&pure_const_state, &looping, | |
1232 | edge_state, edge_looping); | |
1233 | if (pure_const_state == IPA_NEITHER) | |
1234 | break; | |
1235 | } | |
1236 | if (pure_const_state == IPA_NEITHER) | |
1237 | break; | |
ef378c27 | 1238 | |
023a28e1 | 1239 | /* Now process the indirect call. */ |
451e322a | 1240 | for (ie = w->indirect_calls; ie; ie = ie->next_callee) |
023a28e1 | 1241 | { |
1242 | enum pure_const_state_e edge_state = IPA_CONST; | |
1243 | bool edge_looping = false; | |
4c170941 | 1244 | |
023a28e1 | 1245 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1246 | fprintf (dump_file, " Indirect call"); | |
1247 | state_from_flags (&edge_state, &edge_looping, | |
1248 | ie->indirect_info->ecf_flags, | |
1249 | cgraph_edge_cannot_lead_to_return (ie)); | |
1250 | /* Merge the results with what we already know. */ | |
1251 | better_state (&edge_state, &edge_looping, | |
1252 | w_l->state_previously_known, | |
1253 | w_l->looping_previously_known); | |
1254 | worse_state (&pure_const_state, &looping, | |
1255 | edge_state, edge_looping); | |
fc94a528 | 1256 | if (pure_const_state == IPA_NEITHER) |
1257 | break; | |
f7d118a9 | 1258 | } |
023a28e1 | 1259 | if (pure_const_state == IPA_NEITHER) |
1260 | break; | |
1261 | ||
1262 | /* And finally all loads and stores. */ | |
7d0d0ce1 | 1263 | for (i = 0; ipa_ref_list_reference_iterate (&w->symbol.ref_list, i, ref); i++) |
023a28e1 | 1264 | { |
1265 | enum pure_const_state_e ref_state = IPA_CONST; | |
1266 | bool ref_looping = false; | |
1267 | switch (ref->use) | |
1268 | { | |
1269 | case IPA_REF_LOAD: | |
1270 | /* readonly reads are safe. */ | |
7d0d0ce1 | 1271 | if (TREE_READONLY (ipa_ref_varpool_node (ref)->symbol.decl)) |
023a28e1 | 1272 | break; |
1273 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1274 | fprintf (dump_file, " nonreadonly global var read\n"); | |
1275 | ref_state = IPA_PURE; | |
1276 | break; | |
1277 | case IPA_REF_STORE: | |
1278 | if (ipa_ref_cannot_lead_to_return (ref)) | |
1279 | break; | |
1280 | ref_state = IPA_NEITHER; | |
1281 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1282 | fprintf (dump_file, " global var write\n"); | |
1283 | break; | |
1284 | case IPA_REF_ADDR: | |
1285 | break; | |
1286 | } | |
1287 | better_state (&ref_state, &ref_looping, | |
1288 | w_l->state_previously_known, | |
1289 | w_l->looping_previously_known); | |
1290 | worse_state (&pure_const_state, &looping, | |
1291 | ref_state, ref_looping); | |
1292 | if (pure_const_state == IPA_NEITHER) | |
1293 | break; | |
1294 | } | |
7d0d0ce1 | 1295 | w_info = (struct ipa_dfs_info *) w->symbol.aux; |
f7d118a9 | 1296 | w = w_info->next_cycle; |
1297 | } | |
fc94a528 | 1298 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1299 | fprintf (dump_file, "Result %s looping %i\n", | |
1300 | pure_const_names [pure_const_state], | |
1301 | looping); | |
f7d118a9 | 1302 | |
1303 | /* Copy back the region's pure_const_state which is shared by | |
1304 | all nodes in the region. */ | |
1305 | w = node; | |
1306 | while (w) | |
1307 | { | |
1308 | funct_state w_l = get_function_state (w); | |
b5cebd44 | 1309 | enum pure_const_state_e this_state = pure_const_state; |
1310 | bool this_looping = looping; | |
f7d118a9 | 1311 | |
df9b545b | 1312 | if (w_l->state_previously_known != IPA_NEITHER |
1313 | && this_state > w_l->state_previously_known) | |
4c170941 | 1314 | { |
1315 | this_state = w_l->state_previously_known; | |
1316 | this_looping |= w_l->looping_previously_known; | |
1317 | } | |
a1e88032 | 1318 | if (!this_looping && self_recursive_p (w)) |
1319 | this_looping = true; | |
df9b545b | 1320 | if (!w_l->looping_previously_known) |
1321 | this_looping = false; | |
cb886925 | 1322 | |
b5cebd44 | 1323 | /* All nodes within a cycle share the same info. */ |
1324 | w_l->pure_const_state = this_state; | |
1325 | w_l->looping = this_looping; | |
1326 | ||
1327 | switch (this_state) | |
1328 | { | |
1329 | case IPA_CONST: | |
7d0d0ce1 | 1330 | if (!TREE_READONLY (w->symbol.decl)) |
2c06958d | 1331 | { |
7d0d0ce1 | 1332 | warn_function_const (w->symbol.decl, !this_looping); |
2c06958d | 1333 | if (dump_file) |
1334 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
1335 | this_looping ? "looping " : "", | |
1336 | cgraph_node_name (w)); | |
1337 | } | |
7f74ac6b | 1338 | cgraph_set_const_flag (w, true, this_looping); |
b5cebd44 | 1339 | break; |
48e1416a | 1340 | |
b5cebd44 | 1341 | case IPA_PURE: |
7d0d0ce1 | 1342 | if (!DECL_PURE_P (w->symbol.decl)) |
2c06958d | 1343 | { |
7d0d0ce1 | 1344 | warn_function_pure (w->symbol.decl, !this_looping); |
2c06958d | 1345 | if (dump_file) |
1346 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
1347 | this_looping ? "looping " : "", | |
1348 | cgraph_node_name (w)); | |
1349 | } | |
7f74ac6b | 1350 | cgraph_set_pure_flag (w, true, this_looping); |
b5cebd44 | 1351 | break; |
48e1416a | 1352 | |
b5cebd44 | 1353 | default: |
1354 | break; | |
1355 | } | |
7d0d0ce1 | 1356 | w_info = (struct ipa_dfs_info *) w->symbol.aux; |
17b28e52 | 1357 | w = w_info->next_cycle; |
1358 | } | |
1359 | } | |
1360 | ||
7771d558 | 1361 | ipa_free_postorder_info (); |
c0240443 | 1362 | free (order); |
1363 | } | |
1364 | ||
1365 | /* Produce transitive closure over the callgraph and compute nothrow | |
1366 | attributes. */ | |
1367 | ||
1368 | static void | |
1369 | propagate_nothrow (void) | |
1370 | { | |
1371 | struct cgraph_node *node; | |
1372 | struct cgraph_node *w; | |
1373 | struct cgraph_node **order = | |
1374 | XCNEWVEC (struct cgraph_node *, cgraph_n_nodes); | |
1375 | int order_pos; | |
1376 | int i; | |
1377 | struct ipa_dfs_info * w_info; | |
1378 | ||
7771d558 | 1379 | order_pos = ipa_reduced_postorder (order, true, false, ignore_edge); |
17b28e52 | 1380 | if (dump_file) |
1381 | { | |
1382 | dump_cgraph (dump_file); | |
7771d558 | 1383 | ipa_print_order (dump_file, "reduced for nothrow", order, order_pos); |
17b28e52 | 1384 | } |
c0240443 | 1385 | |
9d75589a | 1386 | /* Propagate the local information through the call graph to produce |
17b28e52 | 1387 | the global information. All the nodes within a cycle will have |
1388 | the same info so we collapse cycles first. Then we can do the | |
1389 | propagation in one pass from the leaves to the roots. */ | |
1390 | for (i = 0; i < order_pos; i++ ) | |
1391 | { | |
1392 | bool can_throw = false; | |
1393 | node = order[i]; | |
1394 | ||
8c1fce46 | 1395 | if (node->alias) |
1396 | continue; | |
1397 | ||
17b28e52 | 1398 | /* Find the worst state for any node in the cycle. */ |
1399 | w = node; | |
1400 | while (w) | |
1401 | { | |
023a28e1 | 1402 | struct cgraph_edge *e, *ie; |
17b28e52 | 1403 | funct_state w_l = get_function_state (w); |
1404 | ||
ef378c27 | 1405 | if (w_l->can_throw |
1406 | || cgraph_function_body_availability (w) == AVAIL_OVERWRITABLE) | |
17b28e52 | 1407 | can_throw = true; |
1408 | ||
1409 | if (can_throw) | |
1410 | break; | |
48e1416a | 1411 | |
1412 | for (e = w->callees; e; e = e->next_callee) | |
17b28e52 | 1413 | { |
b2c2e188 | 1414 | enum availability avail; |
1415 | struct cgraph_node *y = cgraph_function_node (e->callee, &avail); | |
17b28e52 | 1416 | |
b2c2e188 | 1417 | if (avail > AVAIL_OVERWRITABLE) |
17b28e52 | 1418 | { |
1419 | funct_state y_l = get_function_state (y); | |
1420 | ||
48e1416a | 1421 | if (can_throw) |
17b28e52 | 1422 | break; |
7d0d0ce1 | 1423 | if (y_l->can_throw && !TREE_NOTHROW (w->symbol.decl) |
17b28e52 | 1424 | && e->can_throw_external) |
1425 | can_throw = true; | |
1426 | } | |
7d0d0ce1 | 1427 | else if (e->can_throw_external && !TREE_NOTHROW (y->symbol.decl)) |
ef378c27 | 1428 | can_throw = true; |
17b28e52 | 1429 | } |
023a28e1 | 1430 | for (ie = node->indirect_calls; ie; ie = ie->next_callee) |
1431 | if (ie->can_throw_external) | |
1432 | can_throw = true; | |
7d0d0ce1 | 1433 | w_info = (struct ipa_dfs_info *) w->symbol.aux; |
17b28e52 | 1434 | w = w_info->next_cycle; |
1435 | } | |
1436 | ||
1437 | /* Copy back the region's pure_const_state which is shared by | |
1438 | all nodes in the region. */ | |
1439 | w = node; | |
1440 | while (w) | |
1441 | { | |
ecfab407 | 1442 | funct_state w_l = get_function_state (w); |
7d0d0ce1 | 1443 | if (!can_throw && !TREE_NOTHROW (w->symbol.decl)) |
b5cebd44 | 1444 | { |
16fcf0f4 | 1445 | cgraph_set_nothrow_flag (w, true); |
b5cebd44 | 1446 | if (dump_file) |
48e1416a | 1447 | fprintf (dump_file, "Function found to be nothrow: %s\n", |
b5cebd44 | 1448 | cgraph_node_name (w)); |
f7d118a9 | 1449 | } |
7d0d0ce1 | 1450 | else if (can_throw && !TREE_NOTHROW (w->symbol.decl)) |
ecfab407 | 1451 | w_l->can_throw = true; |
7d0d0ce1 | 1452 | w_info = (struct ipa_dfs_info *) w->symbol.aux; |
f7d118a9 | 1453 | w = w_info->next_cycle; |
1454 | } | |
1455 | } | |
1456 | ||
7771d558 | 1457 | ipa_free_postorder_info (); |
f7d118a9 | 1458 | free (order); |
c0240443 | 1459 | } |
1460 | ||
1461 | ||
1462 | /* Produce the global information by preforming a transitive closure | |
1463 | on the local information that was produced by generate_summary. */ | |
1464 | ||
1465 | static unsigned int | |
1466 | propagate (void) | |
1467 | { | |
1468 | struct cgraph_node *node; | |
1469 | ||
1470 | cgraph_remove_function_insertion_hook (function_insertion_hook_holder); | |
1471 | cgraph_remove_node_duplication_hook (node_duplication_hook_holder); | |
1472 | cgraph_remove_node_removal_hook (node_removal_hook_holder); | |
1473 | ||
1474 | /* Nothrow makes more function to not lead to return and improve | |
1475 | later analysis. */ | |
1476 | propagate_nothrow (); | |
1477 | propagate_pure_const (); | |
1478 | ||
1479 | /* Cleanup. */ | |
7c455d87 | 1480 | FOR_EACH_DEFINED_FUNCTION (node) |
c0240443 | 1481 | if (has_function_state (node)) |
1482 | free (get_function_state (node)); | |
f1f41a6c | 1483 | funct_state_vec.release (); |
cb886925 | 1484 | finish_state (); |
2a1990e9 | 1485 | return 0; |
f7d118a9 | 1486 | } |
1487 | ||
1488 | static bool | |
1489 | gate_pure_const (void) | |
1490 | { | |
86844d6c | 1491 | return (flag_ipa_pure_const |
f7d118a9 | 1492 | /* Don't bother doing anything if the program has errors. */ |
852f689e | 1493 | && !seen_error ()); |
f7d118a9 | 1494 | } |
1495 | ||
26dbec0a | 1496 | struct ipa_opt_pass_d pass_ipa_pure_const = |
f7d118a9 | 1497 | { |
20099e35 | 1498 | { |
cb886925 | 1499 | IPA_PASS, |
d3d7bd46 | 1500 | "pure-const", /* name */ |
c7875731 | 1501 | OPTGROUP_NONE, /* optinfo_flags */ |
f7d118a9 | 1502 | gate_pure_const, /* gate */ |
cb886925 | 1503 | propagate, /* execute */ |
f7d118a9 | 1504 | NULL, /* sub */ |
1505 | NULL, /* next */ | |
1506 | 0, /* static_pass_number */ | |
1507 | TV_IPA_PURE_CONST, /* tv_id */ | |
1508 | 0, /* properties_required */ | |
1509 | 0, /* properties_provided */ | |
1510 | 0, /* properties_destroyed */ | |
1511 | 0, /* todo_flags_start */ | |
20099e35 | 1512 | 0 /* todo_flags_finish */ |
cb886925 | 1513 | }, |
1514 | generate_summary, /* generate_summary */ | |
7bfefa9d | 1515 | pure_const_write_summary, /* write_summary */ |
1516 | pure_const_read_summary, /* read_summary */ | |
ddc90d88 | 1517 | NULL, /* write_optimization_summary */ |
1518 | NULL, /* read_optimization_summary */ | |
90464c8b | 1519 | NULL, /* stmt_fixup */ |
cb886925 | 1520 | 0, /* TODOs */ |
1521 | NULL, /* function_transform */ | |
1522 | NULL /* variable_transform */ | |
f7d118a9 | 1523 | }; |
b5cebd44 | 1524 | |
2c06958d | 1525 | /* Return true if function should be skipped for local pure const analysis. */ |
b5cebd44 | 1526 | |
2c06958d | 1527 | static bool |
1528 | skip_function_for_local_pure_const (struct cgraph_node *node) | |
b5cebd44 | 1529 | { |
b5cebd44 | 1530 | /* Because we do not schedule pass_fixup_cfg over whole program after early optimizations |
1531 | we must not promote functions that are called by already processed functions. */ | |
1532 | ||
1533 | if (function_called_by_processed_nodes_p ()) | |
1534 | { | |
1535 | if (dump_file) | |
1536 | fprintf (dump_file, "Function called in recursive cycle; ignoring\n"); | |
2c06958d | 1537 | return true; |
b5cebd44 | 1538 | } |
16fcf0f4 | 1539 | if (cgraph_function_body_availability (node) <= AVAIL_OVERWRITABLE) |
b5cebd44 | 1540 | { |
1541 | if (dump_file) | |
0a10fd82 | 1542 | fprintf (dump_file, "Function is not available or overwritable; not analyzing.\n"); |
2c06958d | 1543 | return true; |
b5cebd44 | 1544 | } |
2c06958d | 1545 | return false; |
1546 | } | |
1547 | ||
1548 | /* Simple local pass for pure const discovery reusing the analysis from | |
1549 | ipa_pure_const. This pass is effective when executed together with | |
1550 | other optimization passes in early optimization pass queue. */ | |
b5cebd44 | 1551 | |
2c06958d | 1552 | static unsigned int |
1553 | local_pure_const (void) | |
1554 | { | |
1555 | bool changed = false; | |
1556 | funct_state l; | |
1557 | bool skip; | |
1558 | struct cgraph_node *node; | |
1559 | ||
fd6a3c41 | 1560 | node = cgraph_get_node (current_function_decl); |
2c06958d | 1561 | skip = skip_function_for_local_pure_const (node); |
1562 | if (!warn_suggest_attribute_const | |
1563 | && !warn_suggest_attribute_pure | |
1564 | && skip) | |
1565 | return 0; | |
e0933141 | 1566 | |
ab3db708 | 1567 | l = analyze_function (node, false); |
1568 | ||
1569 | /* Do NORETURN discovery. */ | |
e0933141 | 1570 | if (!skip && !TREE_THIS_VOLATILE (current_function_decl) |
1571 | && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0) | |
1572 | { | |
43d60d64 | 1573 | warn_function_noreturn (cfun->decl); |
e0933141 | 1574 | if (dump_file) |
1575 | fprintf (dump_file, "Function found to be noreturn: %s\n", | |
9631926a | 1576 | current_function_name ()); |
e0933141 | 1577 | |
1578 | /* Update declaration and reduce profile to executed once. */ | |
1579 | TREE_THIS_VOLATILE (current_function_decl) = 1; | |
1580 | if (node->frequency > NODE_FREQUENCY_EXECUTED_ONCE) | |
1581 | node->frequency = NODE_FREQUENCY_EXECUTED_ONCE; | |
1582 | ||
1583 | changed = true; | |
1584 | } | |
ef378c27 | 1585 | |
b5cebd44 | 1586 | switch (l->pure_const_state) |
1587 | { | |
1588 | case IPA_CONST: | |
1589 | if (!TREE_READONLY (current_function_decl)) | |
1590 | { | |
2c06958d | 1591 | warn_function_const (current_function_decl, !l->looping); |
1592 | if (!skip) | |
1593 | { | |
7f74ac6b | 1594 | cgraph_set_const_flag (node, true, l->looping); |
2c06958d | 1595 | changed = true; |
1596 | } | |
b5cebd44 | 1597 | if (dump_file) |
1598 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
1599 | l->looping ? "looping " : "", | |
9631926a | 1600 | current_function_name ()); |
b5cebd44 | 1601 | } |
1602 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
1603 | && !l->looping) | |
1604 | { | |
2c06958d | 1605 | if (!skip) |
1606 | { | |
7f74ac6b | 1607 | cgraph_set_const_flag (node, true, false); |
2c06958d | 1608 | changed = true; |
1609 | } | |
b5cebd44 | 1610 | if (dump_file) |
1611 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 1612 | current_function_name ()); |
b5cebd44 | 1613 | } |
1614 | break; | |
1615 | ||
1616 | case IPA_PURE: | |
2c06958d | 1617 | if (!DECL_PURE_P (current_function_decl)) |
b5cebd44 | 1618 | { |
2c06958d | 1619 | if (!skip) |
1620 | { | |
7f74ac6b | 1621 | cgraph_set_pure_flag (node, true, l->looping); |
2c06958d | 1622 | changed = true; |
1623 | } | |
1624 | warn_function_pure (current_function_decl, !l->looping); | |
b5cebd44 | 1625 | if (dump_file) |
1626 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
1627 | l->looping ? "looping " : "", | |
9631926a | 1628 | current_function_name ()); |
b5cebd44 | 1629 | } |
1630 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
1631 | && !l->looping) | |
1632 | { | |
2c06958d | 1633 | if (!skip) |
1634 | { | |
7f74ac6b | 1635 | cgraph_set_pure_flag (node, true, false); |
2c06958d | 1636 | changed = true; |
1637 | } | |
b5cebd44 | 1638 | if (dump_file) |
1639 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 1640 | current_function_name ()); |
b5cebd44 | 1641 | } |
1642 | break; | |
1643 | ||
1644 | default: | |
1645 | break; | |
1646 | } | |
1647 | if (!l->can_throw && !TREE_NOTHROW (current_function_decl)) | |
1648 | { | |
16fcf0f4 | 1649 | cgraph_set_nothrow_flag (node, true); |
b5cebd44 | 1650 | changed = true; |
1651 | if (dump_file) | |
1652 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
9631926a | 1653 | current_function_name ()); |
b5cebd44 | 1654 | } |
dd045aee | 1655 | free (l); |
b5cebd44 | 1656 | if (changed) |
1657 | return execute_fixup_cfg (); | |
1658 | else | |
1659 | return 0; | |
1660 | } | |
1661 | ||
1662 | struct gimple_opt_pass pass_local_pure_const = | |
1663 | { | |
1664 | { | |
1665 | GIMPLE_PASS, | |
1666 | "local-pure-const", /* name */ | |
c7875731 | 1667 | OPTGROUP_NONE, /* optinfo_flags */ |
b5cebd44 | 1668 | gate_pure_const, /* gate */ |
1669 | local_pure_const, /* execute */ | |
1670 | NULL, /* sub */ | |
1671 | NULL, /* next */ | |
1672 | 0, /* static_pass_number */ | |
1673 | TV_IPA_PURE_CONST, /* tv_id */ | |
1674 | 0, /* properties_required */ | |
1675 | 0, /* properties_provided */ | |
1676 | 0, /* properties_destroyed */ | |
1677 | 0, /* todo_flags_start */ | |
1678 | 0 /* todo_flags_finish */ | |
1679 | } | |
1680 | }; |