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