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f7d118a9 | 1 | /* Callgraph based analysis of static variables. |
711789cc | 2 | Copyright (C) 2004-2013 Free Software Foundation, Inc. |
f7d118a9 | 3 | Contributed by Kenneth Zadeck <zadeck@naturalbridge.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
8c4c00c1 | 9 | Software Foundation; either version 3, or (at your option) any later |
f7d118a9 | 10 | version. |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
8c4c00c1 | 18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
f7d118a9 | 20 | |
f0b5f617 | 21 | /* This file marks functions as being either const (TREE_READONLY) or |
22 | pure (DECL_PURE_P). It can also set a variant of these that | |
23 | are allowed to loop indefinitely (DECL_LOOPING_CONST_PURE_P). | |
f7d118a9 | 24 | |
25 | This must be run after inlining decisions have been made since | |
26 | otherwise, the local sets will not contain information that is | |
27 | consistent with post inlined state. The global sets are not prone | |
28 | to this problem since they are by definition transitive. */ | |
29 | ||
30 | /* The code in this module is called by the ipa pass manager. It | |
31 | should be one of the later passes since it's information is used by | |
32 | the rest of the compilation. */ | |
33 | ||
34 | #include "config.h" | |
35 | #include "system.h" | |
36 | #include "coretypes.h" | |
37 | #include "tm.h" | |
38 | #include "tree.h" | |
39 | #include "tree-flow.h" | |
40 | #include "tree-inline.h" | |
41 | #include "tree-pass.h" | |
42 | #include "langhooks.h" | |
43 | #include "pointer-set.h" | |
44 | #include "ggc.h" | |
45 | #include "ipa-utils.h" | |
75a70cf9 | 46 | #include "gimple.h" |
f7d118a9 | 47 | #include "cgraph.h" |
f7d118a9 | 48 | #include "flags.h" |
f7d118a9 | 49 | #include "diagnostic.h" |
ce084dfc | 50 | #include "gimple-pretty-print.h" |
f7d118a9 | 51 | #include "langhooks.h" |
959fce68 | 52 | #include "target.h" |
7bfefa9d | 53 | #include "lto-streamer.h" |
2541503d | 54 | #include "data-streamer.h" |
55 | #include "tree-streamer.h" | |
c9263b6a | 56 | #include "cfgloop.h" |
57 | #include "tree-scalar-evolution.h" | |
2c06958d | 58 | #include "intl.h" |
59 | #include "opts.h" | |
f7d118a9 | 60 | |
61 | static struct pointer_set_t *visited_nodes; | |
62 | ||
63 | /* Lattice values for const and pure functions. Everything starts out | |
64 | being const, then may drop to pure and then neither depending on | |
65 | what is found. */ | |
66 | enum pure_const_state_e | |
67 | { | |
68 | IPA_CONST, | |
69 | IPA_PURE, | |
70 | IPA_NEITHER | |
71 | }; | |
72 | ||
fc94a528 | 73 | const char *pure_const_names[3] = {"const", "pure", "neither"}; |
74 | ||
cb886925 | 75 | /* Holder for the const_state. There is one of these per function |
76 | decl. */ | |
48e1416a | 77 | struct funct_state_d |
f7d118a9 | 78 | { |
cb886925 | 79 | /* See above. */ |
f7d118a9 | 80 | enum pure_const_state_e pure_const_state; |
b5cebd44 | 81 | /* What user set here; we can be always sure about this. */ |
48e1416a | 82 | enum pure_const_state_e state_previously_known; |
83 | bool looping_previously_known; | |
cb886925 | 84 | |
85 | /* True if the function could possibly infinite loop. There are a | |
86 | lot of ways that this could be determined. We are pretty | |
87 | conservative here. While it is possible to cse pure and const | |
88 | calls, it is not legal to have dce get rid of the call if there | |
89 | is a possibility that the call could infinite loop since this is | |
90 | a behavioral change. */ | |
9c2a0c05 | 91 | bool looping; |
cb886925 | 92 | |
b5cebd44 | 93 | bool can_throw; |
f7d118a9 | 94 | }; |
95 | ||
db86e424 | 96 | /* State used when we know nothing about function. */ |
97 | static struct funct_state_d varying_state | |
98 | = { IPA_NEITHER, IPA_NEITHER, true, true, true }; | |
99 | ||
100 | ||
f7d118a9 | 101 | typedef struct funct_state_d * funct_state; |
102 | ||
cb886925 | 103 | /* The storage of the funct_state is abstracted because there is the |
104 | possibility that it may be desirable to move this to the cgraph | |
48e1416a | 105 | local info. */ |
cb886925 | 106 | |
107 | /* Array, indexed by cgraph node uid, of function states. */ | |
108 | ||
f1f41a6c | 109 | static vec<funct_state> funct_state_vec; |
cb886925 | 110 | |
50828ed8 | 111 | /* Holders of ipa cgraph hooks: */ |
112 | static struct cgraph_node_hook_list *function_insertion_hook_holder; | |
86844d6c | 113 | static struct cgraph_2node_hook_list *node_duplication_hook_holder; |
114 | static struct cgraph_node_hook_list *node_removal_hook_holder; | |
cb886925 | 115 | |
2c06958d | 116 | /* Try to guess if function body will always be visible to compiler |
117 | when compiling the call and whether compiler will be able | |
118 | to propagate the information by itself. */ | |
119 | ||
120 | static bool | |
121 | function_always_visible_to_compiler_p (tree decl) | |
122 | { | |
123 | return (!TREE_PUBLIC (decl) || DECL_DECLARED_INLINE_P (decl)); | |
124 | } | |
125 | ||
126 | /* Emit suggestion about attribute ATTRIB_NAME for DECL. KNOWN_FINITE | |
127 | is true if the function is known to be finite. The diagnostic is | |
128 | controlled by OPTION. WARNED_ABOUT is a pointer_set unique for | |
129 | OPTION, this function may initialize it and it is always returned | |
130 | by the function. */ | |
131 | ||
132 | static struct pointer_set_t * | |
133 | suggest_attribute (int option, tree decl, bool known_finite, | |
134 | struct pointer_set_t *warned_about, | |
135 | const char * attrib_name) | |
136 | { | |
2c5d2e39 | 137 | if (!option_enabled (option, &global_options)) |
2c06958d | 138 | return warned_about; |
139 | if (TREE_THIS_VOLATILE (decl) | |
140 | || (known_finite && function_always_visible_to_compiler_p (decl))) | |
141 | return warned_about; | |
142 | ||
143 | if (!warned_about) | |
144 | warned_about = pointer_set_create (); | |
145 | if (pointer_set_contains (warned_about, decl)) | |
146 | return warned_about; | |
147 | pointer_set_insert (warned_about, decl); | |
148 | warning_at (DECL_SOURCE_LOCATION (decl), | |
149 | option, | |
150 | known_finite | |
151 | ? _("function might be candidate for attribute %<%s%>") | |
152 | : _("function might be candidate for attribute %<%s%>" | |
153 | " if it is known to return normally"), attrib_name); | |
154 | return warned_about; | |
155 | } | |
156 | ||
157 | /* Emit suggestion about __attribute_((pure)) for DECL. KNOWN_FINITE | |
158 | is true if the function is known to be finite. */ | |
159 | ||
160 | static void | |
161 | warn_function_pure (tree decl, bool known_finite) | |
162 | { | |
163 | static struct pointer_set_t *warned_about; | |
164 | ||
165 | warned_about | |
166 | = suggest_attribute (OPT_Wsuggest_attribute_pure, decl, | |
167 | known_finite, warned_about, "pure"); | |
168 | } | |
169 | ||
170 | /* Emit suggestion about __attribute_((const)) for DECL. KNOWN_FINITE | |
171 | is true if the function is known to be finite. */ | |
172 | ||
173 | static void | |
174 | warn_function_const (tree decl, bool known_finite) | |
175 | { | |
176 | static struct pointer_set_t *warned_about; | |
177 | warned_about | |
178 | = suggest_attribute (OPT_Wsuggest_attribute_const, decl, | |
179 | known_finite, warned_about, "const"); | |
180 | } | |
43d60d64 | 181 | |
182 | void | |
183 | warn_function_noreturn (tree decl) | |
184 | { | |
185 | static struct pointer_set_t *warned_about; | |
08c6cbd2 | 186 | if (!lang_hooks.missing_noreturn_ok_p (decl) |
187 | && targetm.warn_func_return (decl)) | |
43d60d64 | 188 | warned_about |
189 | = suggest_attribute (OPT_Wsuggest_attribute_noreturn, decl, | |
190 | true, warned_about, "noreturn"); | |
191 | } | |
9631926a | 192 | |
cb886925 | 193 | /* Init the function state. */ |
194 | ||
195 | static void | |
196 | finish_state (void) | |
197 | { | |
f1f41a6c | 198 | funct_state_vec.release (); |
cb886925 | 199 | } |
200 | ||
201 | ||
1ee39ad1 | 202 | /* Return true if we have a function state for NODE. */ |
203 | ||
204 | static inline bool | |
205 | has_function_state (struct cgraph_node *node) | |
206 | { | |
f1f41a6c | 207 | if (!funct_state_vec.exists () |
208 | || funct_state_vec.length () <= (unsigned int)node->uid) | |
1ee39ad1 | 209 | return false; |
f1f41a6c | 210 | return funct_state_vec[node->uid] != NULL; |
1ee39ad1 | 211 | } |
212 | ||
48e1416a | 213 | /* Return the function state from NODE. */ |
f7d118a9 | 214 | |
215 | static inline funct_state | |
216 | get_function_state (struct cgraph_node *node) | |
217 | { | |
f1f41a6c | 218 | if (!funct_state_vec.exists () |
219 | || funct_state_vec.length () <= (unsigned int)node->uid | |
220 | || !funct_state_vec[node->uid]) | |
1ee39ad1 | 221 | /* We might want to put correct previously_known state into varying. */ |
db86e424 | 222 | return &varying_state; |
f1f41a6c | 223 | return funct_state_vec[node->uid]; |
cb886925 | 224 | } |
225 | ||
226 | /* Set the function state S for NODE. */ | |
227 | ||
228 | static inline void | |
229 | set_function_state (struct cgraph_node *node, funct_state s) | |
230 | { | |
f1f41a6c | 231 | if (!funct_state_vec.exists () |
232 | || funct_state_vec.length () <= (unsigned int)node->uid) | |
233 | funct_state_vec.safe_grow_cleared (node->uid + 1); | |
234 | funct_state_vec[node->uid] = s; | |
f7d118a9 | 235 | } |
236 | ||
f0b5f617 | 237 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
f7d118a9 | 238 | variable T is legal in a function that is either pure or const. */ |
239 | ||
48e1416a | 240 | static inline void |
241 | check_decl (funct_state local, | |
023a28e1 | 242 | tree t, bool checking_write, bool ipa) |
f7d118a9 | 243 | { |
f7d118a9 | 244 | /* Do not want to do anything with volatile except mark any |
245 | function that uses one to be not const or pure. */ | |
48e1416a | 246 | if (TREE_THIS_VOLATILE (t)) |
247 | { | |
f7d118a9 | 248 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 249 | if (dump_file) |
250 | fprintf (dump_file, " Volatile operand is not const/pure"); | |
f7d118a9 | 251 | return; |
252 | } | |
253 | ||
254 | /* Do not care about a local automatic that is not static. */ | |
255 | if (!TREE_STATIC (t) && !DECL_EXTERNAL (t)) | |
256 | return; | |
257 | ||
b5cebd44 | 258 | /* If the variable has the "used" attribute, treat it as if it had a |
259 | been touched by the devil. */ | |
83a23b05 | 260 | if (DECL_PRESERVE_P (t)) |
b5cebd44 | 261 | { |
262 | local->pure_const_state = IPA_NEITHER; | |
263 | if (dump_file) | |
264 | fprintf (dump_file, " Used static/global variable is not const/pure\n"); | |
265 | return; | |
266 | } | |
267 | ||
023a28e1 | 268 | /* In IPA mode we are not interested in checking actual loads and stores; |
269 | they will be processed at propagation time using ipa_ref. */ | |
270 | if (ipa) | |
271 | return; | |
272 | ||
f7d118a9 | 273 | /* Since we have dealt with the locals and params cases above, if we |
274 | are CHECKING_WRITE, this cannot be a pure or constant | |
275 | function. */ | |
48e1416a | 276 | if (checking_write) |
bc17fd99 | 277 | { |
278 | local->pure_const_state = IPA_NEITHER; | |
b5cebd44 | 279 | if (dump_file) |
280 | fprintf (dump_file, " static/global memory write is not const/pure\n"); | |
bc17fd99 | 281 | return; |
282 | } | |
f7d118a9 | 283 | |
284 | if (DECL_EXTERNAL (t) || TREE_PUBLIC (t)) | |
285 | { | |
b5cebd44 | 286 | /* Readonly reads are safe. */ |
287 | if (TREE_READONLY (t) && !TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (t))) | |
288 | return; /* Read of a constant, do not change the function state. */ | |
48e1416a | 289 | else |
f7d118a9 | 290 | { |
b5cebd44 | 291 | if (dump_file) |
292 | fprintf (dump_file, " global memory read is not const\n"); | |
f7d118a9 | 293 | /* Just a regular read. */ |
294 | if (local->pure_const_state == IPA_CONST) | |
295 | local->pure_const_state = IPA_PURE; | |
296 | } | |
297 | } | |
b5cebd44 | 298 | else |
299 | { | |
300 | /* Compilation level statics can be read if they are readonly | |
301 | variables. */ | |
302 | if (TREE_READONLY (t)) | |
303 | return; | |
304 | ||
305 | if (dump_file) | |
306 | fprintf (dump_file, " static memory read is not const\n"); | |
307 | /* Just a regular read. */ | |
308 | if (local->pure_const_state == IPA_CONST) | |
309 | local->pure_const_state = IPA_PURE; | |
310 | } | |
f7d118a9 | 311 | } |
312 | ||
f7d118a9 | 313 | |
b5cebd44 | 314 | /* Check to see if the use (or definition when CHECKING_WRITE is true) |
315 | variable T is legal in a function that is either pure or const. */ | |
f7d118a9 | 316 | |
48e1416a | 317 | static inline void |
5ed0b345 | 318 | check_op (funct_state local, tree t, bool checking_write) |
f7d118a9 | 319 | { |
3ae61172 | 320 | t = get_base_address (t); |
321 | if (t && TREE_THIS_VOLATILE (t)) | |
f7d118a9 | 322 | { |
5ed0b345 | 323 | local->pure_const_state = IPA_NEITHER; |
324 | if (dump_file) | |
325 | fprintf (dump_file, " Volatile indirect ref is not const/pure\n"); | |
326 | return; | |
327 | } | |
3ae61172 | 328 | else if (t |
182cf5a9 | 329 | && (INDIRECT_REF_P (t) || TREE_CODE (t) == MEM_REF) |
3ae61172 | 330 | && TREE_CODE (TREE_OPERAND (t, 0)) == SSA_NAME |
331 | && !ptr_deref_may_alias_global_p (TREE_OPERAND (t, 0))) | |
332 | { | |
333 | if (dump_file) | |
334 | fprintf (dump_file, " Indirect ref to local memory is OK\n"); | |
335 | return; | |
336 | } | |
5ed0b345 | 337 | else if (checking_write) |
338 | { | |
339 | local->pure_const_state = IPA_NEITHER; | |
340 | if (dump_file) | |
341 | fprintf (dump_file, " Indirect ref write is not const/pure\n"); | |
342 | return; | |
343 | } | |
344 | else | |
345 | { | |
346 | if (dump_file) | |
347 | fprintf (dump_file, " Indirect ref read is not const\n"); | |
348 | if (local->pure_const_state == IPA_CONST) | |
349 | local->pure_const_state = IPA_PURE; | |
f7d118a9 | 350 | } |
351 | } | |
352 | ||
023a28e1 | 353 | /* compute state based on ECF FLAGS and store to STATE and LOOPING. */ |
354 | ||
355 | static void | |
356 | state_from_flags (enum pure_const_state_e *state, bool *looping, | |
357 | int flags, bool cannot_lead_to_return) | |
358 | { | |
359 | *looping = false; | |
360 | if (flags & ECF_LOOPING_CONST_OR_PURE) | |
361 | { | |
362 | *looping = true; | |
363 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
364 | fprintf (dump_file, " looping"); | |
365 | } | |
366 | if (flags & ECF_CONST) | |
367 | { | |
368 | *state = IPA_CONST; | |
369 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
370 | fprintf (dump_file, " const\n"); | |
371 | } | |
372 | else if (flags & ECF_PURE) | |
373 | { | |
374 | *state = IPA_PURE; | |
375 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
376 | fprintf (dump_file, " pure\n"); | |
377 | } | |
378 | else if (cannot_lead_to_return) | |
379 | { | |
380 | *state = IPA_PURE; | |
381 | *looping = true; | |
382 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
383 | fprintf (dump_file, " ignoring side effects->pure looping\n"); | |
384 | } | |
385 | else | |
386 | { | |
387 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
9631926a | 388 | fprintf (dump_file, " neither\n"); |
023a28e1 | 389 | *state = IPA_NEITHER; |
390 | *looping = true; | |
391 | } | |
392 | } | |
393 | ||
394 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
395 | into STATE and LOOPING better of the two variants. | |
396 | Be sure to merge looping correctly. IPA_NEITHER functions | |
397 | have looping 0 even if they don't have to return. */ | |
398 | ||
399 | static inline void | |
400 | better_state (enum pure_const_state_e *state, bool *looping, | |
401 | enum pure_const_state_e state2, bool looping2) | |
402 | { | |
403 | if (state2 < *state) | |
404 | { | |
405 | if (*state == IPA_NEITHER) | |
406 | *looping = looping2; | |
407 | else | |
408 | *looping = MIN (*looping, looping2); | |
409 | } | |
410 | else if (state2 != IPA_NEITHER) | |
411 | *looping = MIN (*looping, looping2); | |
412 | } | |
413 | ||
414 | /* Merge STATE and STATE2 and LOOPING and LOOPING2 and store | |
415 | into STATE and LOOPING worse of the two variants. */ | |
416 | ||
417 | static inline void | |
418 | worse_state (enum pure_const_state_e *state, bool *looping, | |
419 | enum pure_const_state_e state2, bool looping2) | |
420 | { | |
421 | *state = MAX (*state, state2); | |
422 | *looping = MAX (*looping, looping2); | |
423 | } | |
424 | ||
0a10fd82 | 425 | /* Recognize special cases of builtins that are by themselves not pure or const |
7dd42908 | 426 | but function using them is. */ |
427 | static bool | |
a53e7471 | 428 | special_builtin_state (enum pure_const_state_e *state, bool *looping, |
7dd42908 | 429 | tree callee) |
430 | { | |
431 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
432 | switch (DECL_FUNCTION_CODE (callee)) | |
433 | { | |
434 | case BUILT_IN_RETURN: | |
435 | case BUILT_IN_UNREACHABLE: | |
436 | case BUILT_IN_ALLOCA: | |
581bf1c2 | 437 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
7dd42908 | 438 | case BUILT_IN_STACK_SAVE: |
439 | case BUILT_IN_STACK_RESTORE: | |
440 | case BUILT_IN_EH_POINTER: | |
441 | case BUILT_IN_EH_FILTER: | |
442 | case BUILT_IN_UNWIND_RESUME: | |
443 | case BUILT_IN_CXA_END_CLEANUP: | |
444 | case BUILT_IN_EH_COPY_VALUES: | |
445 | case BUILT_IN_FRAME_ADDRESS: | |
446 | case BUILT_IN_APPLY: | |
447 | case BUILT_IN_APPLY_ARGS: | |
7dd42908 | 448 | *looping = false; |
449 | *state = IPA_CONST; | |
450 | return true; | |
451 | case BUILT_IN_PREFETCH: | |
452 | *looping = true; | |
453 | *state = IPA_CONST; | |
454 | return true; | |
455 | } | |
456 | return false; | |
457 | } | |
458 | ||
f7d118a9 | 459 | /* Check the parameters of a function call to CALL_EXPR to see if |
460 | there are any references in the parameters that are not allowed for | |
461 | pure or const functions. Also check to see if this is either an | |
462 | indirect call, a call outside the compilation unit, or has special | |
463 | attributes that may also effect the purity. The CALL_EXPR node for | |
464 | the entire call expression. */ | |
465 | ||
466 | static void | |
b5cebd44 | 467 | check_call (funct_state local, gimple call, bool ipa) |
f7d118a9 | 468 | { |
75a70cf9 | 469 | int flags = gimple_call_flags (call); |
b5cebd44 | 470 | tree callee_t = gimple_call_fndecl (call); |
b5cebd44 | 471 | bool possibly_throws = stmt_could_throw_p (call); |
472 | bool possibly_throws_externally = (possibly_throws | |
473 | && stmt_can_throw_external (call)); | |
f7d118a9 | 474 | |
b5cebd44 | 475 | if (possibly_throws) |
476 | { | |
477 | unsigned int i; | |
478 | for (i = 0; i < gimple_num_ops (call); i++) | |
479 | if (gimple_op (call, i) | |
480 | && tree_could_throw_p (gimple_op (call, i))) | |
481 | { | |
cbeb677e | 482 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 483 | { |
484 | if (dump_file) | |
485 | fprintf (dump_file, " operand can throw; looping\n"); | |
486 | local->looping = true; | |
487 | } | |
488 | if (possibly_throws_externally) | |
489 | { | |
490 | if (dump_file) | |
491 | fprintf (dump_file, " operand can throw externally\n"); | |
492 | local->can_throw = true; | |
493 | } | |
494 | } | |
495 | } | |
48e1416a | 496 | |
f7d118a9 | 497 | /* The const and pure flags are set by a variety of places in the |
498 | compiler (including here). If someone has already set the flags | |
499 | for the callee, (such as for some of the builtins) we will use | |
48e1416a | 500 | them, otherwise we will compute our own information. |
501 | ||
f7d118a9 | 502 | Const and pure functions have less clobber effects than other |
503 | functions so we process these first. Otherwise if it is a call | |
504 | outside the compilation unit or an indirect call we punt. This | |
505 | leaves local calls which will be processed by following the call | |
48e1416a | 506 | graph. */ |
f7d118a9 | 507 | if (callee_t) |
508 | { | |
7dd42908 | 509 | enum pure_const_state_e call_state; |
510 | bool call_looping; | |
511 | ||
a53e7471 | 512 | if (special_builtin_state (&call_state, &call_looping, callee_t)) |
7dd42908 | 513 | { |
514 | worse_state (&local->pure_const_state, &local->looping, | |
515 | call_state, call_looping); | |
516 | return; | |
517 | } | |
f7d118a9 | 518 | /* When bad things happen to bad functions, they cannot be const |
519 | or pure. */ | |
520 | if (setjmp_call_p (callee_t)) | |
9c2a0c05 | 521 | { |
b5cebd44 | 522 | if (dump_file) |
523 | fprintf (dump_file, " setjmp is not const/pure\n"); | |
524 | local->looping = true; | |
9c2a0c05 | 525 | local->pure_const_state = IPA_NEITHER; |
9c2a0c05 | 526 | } |
f7d118a9 | 527 | |
528 | if (DECL_BUILT_IN_CLASS (callee_t) == BUILT_IN_NORMAL) | |
529 | switch (DECL_FUNCTION_CODE (callee_t)) | |
530 | { | |
531 | case BUILT_IN_LONGJMP: | |
532 | case BUILT_IN_NONLOCAL_GOTO: | |
b5cebd44 | 533 | if (dump_file) |
534 | fprintf (dump_file, " longjmp and nonlocal goto is not const/pure\n"); | |
f7d118a9 | 535 | local->pure_const_state = IPA_NEITHER; |
b5cebd44 | 536 | local->looping = true; |
f7d118a9 | 537 | break; |
538 | default: | |
539 | break; | |
540 | } | |
541 | } | |
542 | ||
b5cebd44 | 543 | /* When not in IPA mode, we can still handle self recursion. */ |
544 | if (!ipa && callee_t == current_function_decl) | |
2c06958d | 545 | { |
546 | if (dump_file) | |
547 | fprintf (dump_file, " Recursive call can loop.\n"); | |
548 | local->looping = true; | |
549 | } | |
0a10fd82 | 550 | /* Either callee is unknown or we are doing local analysis. |
ef378c27 | 551 | Look to see if there are any bits available for the callee (such as by |
552 | declaration or because it is builtin) and process solely on the basis of | |
553 | those bits. */ | |
023a28e1 | 554 | else if (!ipa) |
f7d118a9 | 555 | { |
023a28e1 | 556 | enum pure_const_state_e call_state; |
557 | bool call_looping; | |
cbeb677e | 558 | if (possibly_throws && cfun->can_throw_non_call_exceptions) |
b5cebd44 | 559 | { |
560 | if (dump_file) | |
561 | fprintf (dump_file, " can throw; looping\n"); | |
562 | local->looping = true; | |
563 | } | |
564 | if (possibly_throws_externally) | |
565 | { | |
566 | if (dump_file) | |
567 | { | |
e38def9c | 568 | fprintf (dump_file, " can throw externally to lp %i\n", |
569 | lookup_stmt_eh_lp (call)); | |
b5cebd44 | 570 | if (callee_t) |
571 | fprintf (dump_file, " callee:%s\n", | |
572 | IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (callee_t))); | |
573 | } | |
574 | local->can_throw = true; | |
575 | } | |
023a28e1 | 576 | if (dump_file && (dump_flags & TDF_DETAILS)) |
577 | fprintf (dump_file, " checking flags for call:"); | |
578 | state_from_flags (&call_state, &call_looping, flags, | |
579 | ((flags & (ECF_NORETURN | ECF_NOTHROW)) | |
580 | == (ECF_NORETURN | ECF_NOTHROW)) | |
581 | || (!flag_exceptions && (flags & ECF_NORETURN))); | |
582 | worse_state (&local->pure_const_state, &local->looping, | |
583 | call_state, call_looping); | |
f7d118a9 | 584 | } |
b5cebd44 | 585 | /* Direct functions calls are handled by IPA propagation. */ |
f7d118a9 | 586 | } |
587 | ||
023a28e1 | 588 | /* Wrapper around check_decl for loads in local more. */ |
5ed0b345 | 589 | |
590 | static bool | |
591 | check_load (gimple stmt ATTRIBUTE_UNUSED, tree op, void *data) | |
592 | { | |
593 | if (DECL_P (op)) | |
023a28e1 | 594 | check_decl ((funct_state)data, op, false, false); |
5ed0b345 | 595 | else |
596 | check_op ((funct_state)data, op, false); | |
597 | return false; | |
598 | } | |
599 | ||
023a28e1 | 600 | /* Wrapper around check_decl for stores in local more. */ |
5ed0b345 | 601 | |
602 | static bool | |
603 | check_store (gimple stmt ATTRIBUTE_UNUSED, tree op, void *data) | |
604 | { | |
605 | if (DECL_P (op)) | |
023a28e1 | 606 | check_decl ((funct_state)data, op, true, false); |
607 | else | |
608 | check_op ((funct_state)data, op, true); | |
609 | return false; | |
610 | } | |
611 | ||
612 | /* Wrapper around check_decl for loads in ipa mode. */ | |
613 | ||
614 | static bool | |
615 | check_ipa_load (gimple stmt ATTRIBUTE_UNUSED, tree op, void *data) | |
616 | { | |
617 | if (DECL_P (op)) | |
618 | check_decl ((funct_state)data, op, false, true); | |
619 | else | |
620 | check_op ((funct_state)data, op, false); | |
621 | return false; | |
622 | } | |
623 | ||
624 | /* Wrapper around check_decl for stores in ipa mode. */ | |
625 | ||
626 | static bool | |
627 | check_ipa_store (gimple stmt ATTRIBUTE_UNUSED, tree op, void *data) | |
628 | { | |
629 | if (DECL_P (op)) | |
630 | check_decl ((funct_state)data, op, true, true); | |
5ed0b345 | 631 | else |
632 | check_op ((funct_state)data, op, true); | |
633 | return false; | |
634 | } | |
635 | ||
dd277d48 | 636 | /* Look into pointer pointed to by GSIP and figure out what interesting side |
637 | effects it has. */ | |
b5cebd44 | 638 | static void |
639 | check_stmt (gimple_stmt_iterator *gsip, funct_state local, bool ipa) | |
f7d118a9 | 640 | { |
b5cebd44 | 641 | gimple stmt = gsi_stmt (*gsip); |
f7d118a9 | 642 | |
9845d120 | 643 | if (is_gimple_debug (stmt)) |
644 | return; | |
645 | ||
b5cebd44 | 646 | if (dump_file) |
f7d118a9 | 647 | { |
b5cebd44 | 648 | fprintf (dump_file, " scanning: "); |
649 | print_gimple_stmt (dump_file, stmt, 0, 0); | |
650 | } | |
dd277d48 | 651 | |
541c6dbb | 652 | if (gimple_has_volatile_ops (stmt) |
653 | && !gimple_clobber_p (stmt)) | |
4b68df2e | 654 | { |
655 | local->pure_const_state = IPA_NEITHER; | |
656 | if (dump_file) | |
657 | fprintf (dump_file, " Volatile stmt is not const/pure\n"); | |
658 | } | |
659 | ||
5ed0b345 | 660 | /* Look for loads and stores. */ |
023a28e1 | 661 | walk_stmt_load_store_ops (stmt, local, |
662 | ipa ? check_ipa_load : check_load, | |
663 | ipa ? check_ipa_store : check_store); | |
b5cebd44 | 664 | |
665 | if (gimple_code (stmt) != GIMPLE_CALL | |
666 | && stmt_could_throw_p (stmt)) | |
667 | { | |
cbeb677e | 668 | if (cfun->can_throw_non_call_exceptions) |
b5cebd44 | 669 | { |
670 | if (dump_file) | |
10f4615f | 671 | fprintf (dump_file, " can throw; looping\n"); |
b5cebd44 | 672 | local->looping = true; |
673 | } | |
674 | if (stmt_can_throw_external (stmt)) | |
675 | { | |
676 | if (dump_file) | |
10f4615f | 677 | fprintf (dump_file, " can throw externally\n"); |
b5cebd44 | 678 | local->can_throw = true; |
679 | } | |
10f4615f | 680 | else |
681 | if (dump_file) | |
682 | fprintf (dump_file, " can throw\n"); | |
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) |
10f4615f | 694 | fprintf (dump_file, " nonlocal label is not const/pure\n"); |
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) |
10f4615f | 702 | fprintf (dump_file, " memory asm clobber is not const/pure\n"); |
97cf41ec | 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) | |
10f4615f | 709 | fprintf (dump_file, " volatile is not const/pure\n"); |
b5cebd44 | 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 | ||
15ca8f90 | 741 | if (fn->thunk.thunk_p || fn->symbol.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 |
8ff30f9a | 782 | proved to be finite in testcases such as in loop-15.c |
783 | and loop-24.c */ | |
784 | loop_optimizer_init (LOOPS_HAVE_PREHEADERS | |
785 | | LOOPS_HAVE_SIMPLE_LATCHES | |
b1887855 | 786 | | LOOPS_HAVE_RECORDED_EXITS); |
c9263b6a | 787 | if (dump_file && (dump_flags & TDF_DETAILS)) |
788 | flow_loops_dump (dump_file, NULL, 0); | |
789 | if (mark_irreducible_loops ()) | |
790 | { | |
791 | if (dump_file) | |
792 | fprintf (dump_file, " has irreducible loops\n"); | |
793 | l->looping = true; | |
794 | } | |
48e1416a | 795 | else |
c9263b6a | 796 | { |
797 | loop_iterator li; | |
798 | struct loop *loop; | |
799 | scev_initialize (); | |
800 | FOR_EACH_LOOP (li, loop, 0) | |
801 | if (!finite_loop_p (loop)) | |
802 | { | |
803 | if (dump_file) | |
8ff30f9a | 804 | fprintf (dump_file, " can not prove finiteness of " |
805 | "loop %i\n", loop->num); | |
c9263b6a | 806 | l->looping =true; |
83b709f2 | 807 | FOR_EACH_LOOP_BREAK (li); |
c9263b6a | 808 | } |
809 | scev_finalize (); | |
810 | } | |
811 | loop_optimizer_finalize (); | |
812 | } | |
b5cebd44 | 813 | } |
814 | ||
023a28e1 | 815 | if (dump_file && (dump_flags & TDF_DETAILS)) |
816 | fprintf (dump_file, " checking previously known:"); | |
023a28e1 | 817 | |
818 | better_state (&l->pure_const_state, &l->looping, | |
819 | l->state_previously_known, | |
820 | l->looping_previously_known); | |
b5cebd44 | 821 | if (TREE_NOTHROW (decl)) |
822 | l->can_throw = false; | |
823 | ||
824 | pop_cfun (); | |
dcccac3e | 825 | if (dump_file) |
826 | { | |
b5cebd44 | 827 | if (l->looping) |
828 | fprintf (dump_file, "Function is locally looping.\n"); | |
829 | if (l->can_throw) | |
830 | fprintf (dump_file, "Function is locally throwing.\n"); | |
831 | if (l->pure_const_state == IPA_CONST) | |
832 | fprintf (dump_file, "Function is locally const.\n"); | |
833 | if (l->pure_const_state == IPA_PURE) | |
834 | fprintf (dump_file, "Function is locally pure.\n"); | |
dcccac3e | 835 | } |
b5cebd44 | 836 | return l; |
f7d118a9 | 837 | } |
838 | ||
50828ed8 | 839 | /* Called when new function is inserted to callgraph late. */ |
840 | static void | |
841 | add_new_function (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED) | |
842 | { | |
ef378c27 | 843 | if (cgraph_function_body_availability (node) < AVAIL_OVERWRITABLE) |
86844d6c | 844 | return; |
50828ed8 | 845 | /* There are some shared nodes, in particular the initializers on |
846 | static declarations. We do not need to scan them more than once | |
847 | since all we would be interested in are the addressof | |
848 | operations. */ | |
849 | visited_nodes = pointer_set_create (); | |
2c06958d | 850 | if (cgraph_function_body_availability (node) > AVAIL_OVERWRITABLE) |
851 | set_function_state (node, analyze_function (node, true)); | |
50828ed8 | 852 | pointer_set_destroy (visited_nodes); |
853 | visited_nodes = NULL; | |
854 | } | |
855 | ||
86844d6c | 856 | /* Called when new clone is inserted to callgraph late. */ |
857 | ||
858 | static void | |
859 | duplicate_node_data (struct cgraph_node *src, struct cgraph_node *dst, | |
860 | void *data ATTRIBUTE_UNUSED) | |
861 | { | |
1ee39ad1 | 862 | if (has_function_state (src)) |
86844d6c | 863 | { |
864 | funct_state l = XNEW (struct funct_state_d); | |
1ee39ad1 | 865 | gcc_assert (!has_function_state (dst)); |
86844d6c | 866 | memcpy (l, get_function_state (src), sizeof (*l)); |
867 | set_function_state (dst, l); | |
868 | } | |
869 | } | |
870 | ||
871 | /* Called when new clone is inserted to callgraph late. */ | |
872 | ||
873 | static void | |
874 | remove_node_data (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED) | |
875 | { | |
1ee39ad1 | 876 | if (has_function_state (node)) |
86844d6c | 877 | { |
db86e424 | 878 | funct_state l = get_function_state (node); |
879 | if (l != &varying_state) | |
880 | free (l); | |
86844d6c | 881 | set_function_state (node, NULL); |
882 | } | |
883 | } | |
884 | ||
f7d118a9 | 885 | \f |
7bfefa9d | 886 | static void |
887 | register_hooks (void) | |
f7d118a9 | 888 | { |
7bfefa9d | 889 | static bool init_p = false; |
890 | ||
891 | if (init_p) | |
892 | return; | |
893 | ||
894 | init_p = true; | |
f7d118a9 | 895 | |
86844d6c | 896 | node_removal_hook_holder = |
897 | cgraph_add_node_removal_hook (&remove_node_data, NULL); | |
898 | node_duplication_hook_holder = | |
899 | cgraph_add_node_duplication_hook (&duplicate_node_data, NULL); | |
50828ed8 | 900 | function_insertion_hook_holder = |
901 | cgraph_add_function_insertion_hook (&add_new_function, NULL); | |
7bfefa9d | 902 | } |
903 | ||
904 | ||
905 | /* Analyze each function in the cgraph to see if it is locally PURE or | |
906 | CONST. */ | |
907 | ||
48e1416a | 908 | static void |
80880eb6 | 909 | pure_const_generate_summary (void) |
7bfefa9d | 910 | { |
911 | struct cgraph_node *node; | |
912 | ||
913 | register_hooks (); | |
914 | ||
f7d118a9 | 915 | /* There are some shared nodes, in particular the initializers on |
916 | static declarations. We do not need to scan them more than once | |
917 | since all we would be interested in are the addressof | |
918 | operations. */ | |
919 | visited_nodes = pointer_set_create (); | |
920 | ||
48e1416a | 921 | /* Process all of the functions. |
f7d118a9 | 922 | |
ef378c27 | 923 | We process AVAIL_OVERWRITABLE functions. We can not use the results |
924 | by default, but the info can be used at LTO with -fwhole-program or | |
0a10fd82 | 925 | when function got cloned and the clone is AVAILABLE. */ |
ef378c27 | 926 | |
7c455d87 | 927 | FOR_EACH_DEFINED_FUNCTION (node) |
ef378c27 | 928 | if (cgraph_function_body_availability (node) >= AVAIL_OVERWRITABLE) |
b5cebd44 | 929 | set_function_state (node, analyze_function (node, true)); |
f7d118a9 | 930 | |
931 | pointer_set_destroy (visited_nodes); | |
932 | visited_nodes = NULL; | |
cb886925 | 933 | } |
934 | ||
7bfefa9d | 935 | |
936 | /* Serialize the ipa info for lto. */ | |
937 | ||
938 | static void | |
eab36a5a | 939 | pure_const_write_summary (void) |
7bfefa9d | 940 | { |
941 | struct cgraph_node *node; | |
942 | struct lto_simple_output_block *ob | |
943 | = lto_create_simple_output_block (LTO_section_ipa_pure_const); | |
944 | unsigned int count = 0; | |
eab36a5a | 945 | lto_symtab_encoder_iterator lsei; |
946 | lto_symtab_encoder_t encoder; | |
7bfefa9d | 947 | |
eab36a5a | 948 | encoder = lto_get_out_decl_state ()->symtab_node_encoder; |
949 | ||
950 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); | |
951 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 952 | { |
eab36a5a | 953 | node = lsei_cgraph_node (lsei); |
15ca8f90 | 954 | if (node->symbol.definition && has_function_state (node)) |
7bfefa9d | 955 | count++; |
956 | } | |
48e1416a | 957 | |
7f385784 | 958 | streamer_write_uhwi_stream (ob->main_stream, count); |
48e1416a | 959 | |
7bfefa9d | 960 | /* Process all of the functions. */ |
eab36a5a | 961 | for (lsei = lsei_start_function_in_partition (encoder); !lsei_end_p (lsei); |
962 | lsei_next_function_in_partition (&lsei)) | |
7bfefa9d | 963 | { |
eab36a5a | 964 | node = lsei_cgraph_node (lsei); |
15ca8f90 | 965 | if (node->symbol.definition && has_function_state (node)) |
7bfefa9d | 966 | { |
30baba90 | 967 | struct bitpack_d bp; |
7bfefa9d | 968 | funct_state fs; |
969 | int node_ref; | |
70225339 | 970 | lto_symtab_encoder_t encoder; |
48e1416a | 971 | |
7bfefa9d | 972 | fs = get_function_state (node); |
973 | ||
70225339 | 974 | encoder = ob->decl_state->symtab_node_encoder; |
975 | node_ref = lto_symtab_encoder_encode (encoder, (symtab_node)node); | |
7f385784 | 976 | streamer_write_uhwi_stream (ob->main_stream, node_ref); |
48e1416a | 977 | |
7bfefa9d | 978 | /* Note that flags will need to be read in the opposite |
979 | order as we are pushing the bitflags into FLAGS. */ | |
30baba90 | 980 | bp = bitpack_create (ob->main_stream); |
981 | bp_pack_value (&bp, fs->pure_const_state, 2); | |
982 | bp_pack_value (&bp, fs->state_previously_known, 2); | |
983 | bp_pack_value (&bp, fs->looping_previously_known, 1); | |
984 | bp_pack_value (&bp, fs->looping, 1); | |
985 | bp_pack_value (&bp, fs->can_throw, 1); | |
7f385784 | 986 | streamer_write_bitpack (&bp); |
7bfefa9d | 987 | } |
988 | } | |
989 | ||
990 | lto_destroy_simple_output_block (ob); | |
991 | } | |
992 | ||
993 | ||
994 | /* Deserialize the ipa info for lto. */ | |
995 | ||
48e1416a | 996 | static void |
7bfefa9d | 997 | pure_const_read_summary (void) |
998 | { | |
999 | struct lto_file_decl_data **file_data_vec = lto_get_file_decl_data (); | |
1000 | struct lto_file_decl_data *file_data; | |
1001 | unsigned int j = 0; | |
1002 | ||
1003 | register_hooks (); | |
1004 | while ((file_data = file_data_vec[j++])) | |
1005 | { | |
1006 | const char *data; | |
1007 | size_t len; | |
1008 | struct lto_input_block *ib | |
48e1416a | 1009 | = lto_create_simple_input_block (file_data, |
1010 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1011 | &data, &len); |
1012 | if (ib) | |
1013 | { | |
1014 | unsigned int i; | |
7f385784 | 1015 | unsigned int count = streamer_read_uhwi (ib); |
7bfefa9d | 1016 | |
1017 | for (i = 0; i < count; i++) | |
1018 | { | |
1019 | unsigned int index; | |
1020 | struct cgraph_node *node; | |
30baba90 | 1021 | struct bitpack_d bp; |
7bfefa9d | 1022 | funct_state fs; |
70225339 | 1023 | lto_symtab_encoder_t encoder; |
7bfefa9d | 1024 | |
1025 | fs = XCNEW (struct funct_state_d); | |
7f385784 | 1026 | index = streamer_read_uhwi (ib); |
70225339 | 1027 | encoder = file_data->symtab_node_encoder; |
1028 | node = cgraph (lto_symtab_encoder_deref (encoder, index)); | |
7bfefa9d | 1029 | set_function_state (node, fs); |
1030 | ||
1031 | /* Note that the flags must be read in the opposite | |
1032 | order in which they were written (the bitflags were | |
1033 | pushed into FLAGS). */ | |
7f385784 | 1034 | bp = streamer_read_bitpack (ib); |
7bfefa9d | 1035 | fs->pure_const_state |
30baba90 | 1036 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
7bfefa9d | 1037 | fs->state_previously_known |
30baba90 | 1038 | = (enum pure_const_state_e) bp_unpack_value (&bp, 2); |
1039 | fs->looping_previously_known = bp_unpack_value (&bp, 1); | |
1040 | fs->looping = bp_unpack_value (&bp, 1); | |
1041 | fs->can_throw = bp_unpack_value (&bp, 1); | |
fc94a528 | 1042 | if (dump_file) |
1043 | { | |
7d0d0ce1 | 1044 | int flags = flags_from_decl_or_type (node->symbol.decl); |
fc94a528 | 1045 | fprintf (dump_file, "Read info for %s/%i ", |
1046 | cgraph_node_name (node), | |
15c999e3 | 1047 | node->symbol.order); |
fc94a528 | 1048 | if (flags & ECF_CONST) |
1049 | fprintf (dump_file, " const"); | |
1050 | if (flags & ECF_PURE) | |
1051 | fprintf (dump_file, " pure"); | |
1052 | if (flags & ECF_NOTHROW) | |
1053 | fprintf (dump_file, " nothrow"); | |
1054 | fprintf (dump_file, "\n pure const state: %s\n", | |
1055 | pure_const_names[fs->pure_const_state]); | |
1056 | fprintf (dump_file, " previously known state: %s\n", | |
1057 | pure_const_names[fs->looping_previously_known]); | |
1058 | if (fs->looping) | |
1059 | fprintf (dump_file," function is locally looping\n"); | |
1060 | if (fs->looping_previously_known) | |
1061 | fprintf (dump_file," function is previously known looping\n"); | |
1062 | if (fs->can_throw) | |
1063 | fprintf (dump_file," function is locally throwing\n"); | |
1064 | } | |
7bfefa9d | 1065 | } |
1066 | ||
48e1416a | 1067 | lto_destroy_simple_input_block (file_data, |
1068 | LTO_section_ipa_pure_const, | |
7bfefa9d | 1069 | ib, data, len); |
1070 | } | |
1071 | } | |
1072 | } | |
1073 | ||
1074 | ||
17b28e52 | 1075 | static bool |
1076 | ignore_edge (struct cgraph_edge *e) | |
1077 | { | |
1078 | return (!e->can_throw_external); | |
1079 | } | |
1080 | ||
b2c2e188 | 1081 | /* Return true if NODE is self recursive function. |
1082 | ??? self recursive and indirectly recursive funcions should | |
a04e8d62 | 1083 | be the same, so this function seems unnecessary. */ |
a1e88032 | 1084 | |
1085 | static bool | |
1086 | self_recursive_p (struct cgraph_node *node) | |
1087 | { | |
1088 | struct cgraph_edge *e; | |
1089 | for (e = node->callees; e; e = e->next_callee) | |
b2c2e188 | 1090 | if (cgraph_function_node (e->callee, NULL) == node) |
a1e88032 | 1091 | return true; |
1092 | return false; | |
1093 | } | |
1094 | ||
c0240443 | 1095 | /* Produce transitive closure over the callgraph and compute pure/const |
1096 | attributes. */ | |
023a28e1 | 1097 | |
c0240443 | 1098 | static void |
1099 | propagate_pure_const (void) | |
cb886925 | 1100 | { |
1101 | struct cgraph_node *node; | |
1102 | struct cgraph_node *w; | |
1103 | struct cgraph_node **order = | |
1104 | XCNEWVEC (struct cgraph_node *, cgraph_n_nodes); | |
1105 | int order_pos; | |
1106 | int i; | |
1107 | struct ipa_dfs_info * w_info; | |
1108 | ||
7771d558 | 1109 | order_pos = ipa_reduced_postorder (order, true, false, NULL); |
f7d118a9 | 1110 | if (dump_file) |
1111 | { | |
1112 | dump_cgraph (dump_file); | |
48669653 | 1113 | ipa_print_order (dump_file, "reduced", order, order_pos); |
f7d118a9 | 1114 | } |
1115 | ||
9d75589a | 1116 | /* Propagate the local information through the call graph to produce |
f7d118a9 | 1117 | the global information. All the nodes within a cycle will have |
1118 | the same info so we collapse cycles first. Then we can do the | |
1119 | propagation in one pass from the leaves to the roots. */ | |
1120 | for (i = 0; i < order_pos; i++ ) | |
1121 | { | |
1122 | enum pure_const_state_e pure_const_state = IPA_CONST; | |
9c2a0c05 | 1123 | bool looping = false; |
54157bf1 | 1124 | int count = 0; |
f7d118a9 | 1125 | node = order[i]; |
1126 | ||
15ca8f90 | 1127 | if (node->symbol.alias) |
8c1fce46 | 1128 | continue; |
1129 | ||
fc94a528 | 1130 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1131 | fprintf (dump_file, "Starting cycle\n"); | |
1132 | ||
f7d118a9 | 1133 | /* Find the worst state for any node in the cycle. */ |
1134 | w = node; | |
023a28e1 | 1135 | while (w && pure_const_state != IPA_NEITHER) |
f7d118a9 | 1136 | { |
b5cebd44 | 1137 | struct cgraph_edge *e; |
023a28e1 | 1138 | struct cgraph_edge *ie; |
1139 | int i; | |
1140 | struct ipa_ref *ref; | |
1141 | ||
f7d118a9 | 1142 | funct_state w_l = get_function_state (w); |
fc94a528 | 1143 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1144 | fprintf (dump_file, " Visiting %s/%i state:%s looping %i\n", | |
1145 | cgraph_node_name (w), | |
15c999e3 | 1146 | w->symbol.order, |
fc94a528 | 1147 | pure_const_names[w_l->pure_const_state], |
1148 | w_l->looping); | |
f7d118a9 | 1149 | |
023a28e1 | 1150 | /* First merge in function body properties. */ |
1151 | worse_state (&pure_const_state, &looping, | |
1152 | w_l->pure_const_state, w_l->looping); | |
1153 | if (pure_const_state == IPA_NEITHER) | |
1154 | break; | |
1155 | ||
1156 | /* For overwritable nodes we can not assume anything. */ | |
ef378c27 | 1157 | if (cgraph_function_body_availability (w) == AVAIL_OVERWRITABLE) |
1158 | { | |
023a28e1 | 1159 | worse_state (&pure_const_state, &looping, |
1160 | w_l->state_previously_known, | |
1161 | w_l->looping_previously_known); | |
fc94a528 | 1162 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1163 | { | |
1164 | fprintf (dump_file, | |
1165 | " Overwritable. state %s looping %i\n", | |
1166 | pure_const_names[w_l->state_previously_known], | |
1167 | w_l->looping_previously_known); | |
1168 | } | |
023a28e1 | 1169 | break; |
ef378c27 | 1170 | } |
9c2a0c05 | 1171 | |
b5cebd44 | 1172 | count++; |
1173 | ||
023a28e1 | 1174 | /* We consider recursive cycles as possibly infinite. |
1175 | This might be relaxed since infinite recursion leads to stack | |
1176 | overflow. */ | |
b5cebd44 | 1177 | if (count > 1) |
1178 | looping = true; | |
48e1416a | 1179 | |
023a28e1 | 1180 | /* Now walk the edges and merge in callee properties. */ |
48e1416a | 1181 | for (e = w->callees; e; e = e->next_callee) |
f7d118a9 | 1182 | { |
b2c2e188 | 1183 | enum availability avail; |
1184 | struct cgraph_node *y = cgraph_function_node (e->callee, &avail); | |
fc94a528 | 1185 | enum pure_const_state_e edge_state = IPA_CONST; |
1186 | bool edge_looping = false; | |
54157bf1 | 1187 | |
fc94a528 | 1188 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1189 | { | |
1190 | fprintf (dump_file, | |
1191 | " Call to %s/%i", | |
1192 | cgraph_node_name (e->callee), | |
15c999e3 | 1193 | e->callee->symbol.order); |
fc94a528 | 1194 | } |
b2c2e188 | 1195 | if (avail > AVAIL_OVERWRITABLE) |
f7d118a9 | 1196 | { |
b5cebd44 | 1197 | funct_state y_l = get_function_state (y); |
fc94a528 | 1198 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1199 | { | |
1200 | fprintf (dump_file, | |
1201 | " state:%s looping:%i\n", | |
1202 | pure_const_names[y_l->pure_const_state], | |
1203 | y_l->looping); | |
1204 | } | |
4c170941 | 1205 | if (y_l->pure_const_state > IPA_PURE |
1ee39ad1 | 1206 | && cgraph_edge_cannot_lead_to_return (e)) |
fc94a528 | 1207 | { |
1208 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
023a28e1 | 1209 | fprintf (dump_file, |
1210 | " Ignoring side effects" | |
1211 | " -> pure, looping\n"); | |
fc94a528 | 1212 | edge_state = IPA_PURE; |
1213 | edge_looping = true; | |
1214 | } | |
1215 | else | |
1216 | { | |
1217 | edge_state = y_l->pure_const_state; | |
1218 | edge_looping = y_l->looping; | |
1219 | } | |
f7d118a9 | 1220 | } |
a53e7471 | 1221 | else if (special_builtin_state (&edge_state, &edge_looping, |
7d0d0ce1 | 1222 | y->symbol.decl)) |
7dd42908 | 1223 | ; |
ef378c27 | 1224 | else |
023a28e1 | 1225 | state_from_flags (&edge_state, &edge_looping, |
7d0d0ce1 | 1226 | flags_from_decl_or_type (y->symbol.decl), |
7dd42908 | 1227 | cgraph_edge_cannot_lead_to_return (e)); |
023a28e1 | 1228 | |
1229 | /* Merge the results with what we already know. */ | |
1230 | better_state (&edge_state, &edge_looping, | |
1231 | w_l->state_previously_known, | |
1232 | w_l->looping_previously_known); | |
1233 | worse_state (&pure_const_state, &looping, | |
1234 | edge_state, edge_looping); | |
1235 | if (pure_const_state == IPA_NEITHER) | |
1236 | break; | |
1237 | } | |
1238 | if (pure_const_state == IPA_NEITHER) | |
1239 | break; | |
ef378c27 | 1240 | |
023a28e1 | 1241 | /* Now process the indirect call. */ |
451e322a | 1242 | for (ie = w->indirect_calls; ie; ie = ie->next_callee) |
023a28e1 | 1243 | { |
1244 | enum pure_const_state_e edge_state = IPA_CONST; | |
1245 | bool edge_looping = false; | |
4c170941 | 1246 | |
023a28e1 | 1247 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1248 | fprintf (dump_file, " Indirect call"); | |
1249 | state_from_flags (&edge_state, &edge_looping, | |
1250 | ie->indirect_info->ecf_flags, | |
1251 | cgraph_edge_cannot_lead_to_return (ie)); | |
1252 | /* Merge the results with what we already know. */ | |
1253 | better_state (&edge_state, &edge_looping, | |
1254 | w_l->state_previously_known, | |
1255 | w_l->looping_previously_known); | |
1256 | worse_state (&pure_const_state, &looping, | |
1257 | edge_state, edge_looping); | |
fc94a528 | 1258 | if (pure_const_state == IPA_NEITHER) |
1259 | break; | |
f7d118a9 | 1260 | } |
023a28e1 | 1261 | if (pure_const_state == IPA_NEITHER) |
1262 | break; | |
1263 | ||
1264 | /* And finally all loads and stores. */ | |
7d0d0ce1 | 1265 | for (i = 0; ipa_ref_list_reference_iterate (&w->symbol.ref_list, i, ref); i++) |
023a28e1 | 1266 | { |
1267 | enum pure_const_state_e ref_state = IPA_CONST; | |
1268 | bool ref_looping = false; | |
1269 | switch (ref->use) | |
1270 | { | |
1271 | case IPA_REF_LOAD: | |
1272 | /* readonly reads are safe. */ | |
7d0d0ce1 | 1273 | if (TREE_READONLY (ipa_ref_varpool_node (ref)->symbol.decl)) |
023a28e1 | 1274 | break; |
1275 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1276 | fprintf (dump_file, " nonreadonly global var read\n"); | |
1277 | ref_state = IPA_PURE; | |
1278 | break; | |
1279 | case IPA_REF_STORE: | |
1280 | if (ipa_ref_cannot_lead_to_return (ref)) | |
1281 | break; | |
1282 | ref_state = IPA_NEITHER; | |
1283 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1284 | fprintf (dump_file, " global var write\n"); | |
1285 | break; | |
1286 | case IPA_REF_ADDR: | |
1287 | break; | |
1288 | } | |
1289 | better_state (&ref_state, &ref_looping, | |
1290 | w_l->state_previously_known, | |
1291 | w_l->looping_previously_known); | |
1292 | worse_state (&pure_const_state, &looping, | |
1293 | ref_state, ref_looping); | |
1294 | if (pure_const_state == IPA_NEITHER) | |
1295 | break; | |
1296 | } | |
7d0d0ce1 | 1297 | w_info = (struct ipa_dfs_info *) w->symbol.aux; |
f7d118a9 | 1298 | w = w_info->next_cycle; |
1299 | } | |
fc94a528 | 1300 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1301 | fprintf (dump_file, "Result %s looping %i\n", | |
1302 | pure_const_names [pure_const_state], | |
1303 | looping); | |
f7d118a9 | 1304 | |
1305 | /* Copy back the region's pure_const_state which is shared by | |
1306 | all nodes in the region. */ | |
1307 | w = node; | |
1308 | while (w) | |
1309 | { | |
1310 | funct_state w_l = get_function_state (w); | |
b5cebd44 | 1311 | enum pure_const_state_e this_state = pure_const_state; |
1312 | bool this_looping = looping; | |
f7d118a9 | 1313 | |
df9b545b | 1314 | if (w_l->state_previously_known != IPA_NEITHER |
1315 | && this_state > w_l->state_previously_known) | |
4c170941 | 1316 | { |
1317 | this_state = w_l->state_previously_known; | |
1318 | this_looping |= w_l->looping_previously_known; | |
1319 | } | |
a1e88032 | 1320 | if (!this_looping && self_recursive_p (w)) |
1321 | this_looping = true; | |
df9b545b | 1322 | if (!w_l->looping_previously_known) |
1323 | this_looping = false; | |
cb886925 | 1324 | |
b5cebd44 | 1325 | /* All nodes within a cycle share the same info. */ |
1326 | w_l->pure_const_state = this_state; | |
1327 | w_l->looping = this_looping; | |
1328 | ||
1329 | switch (this_state) | |
1330 | { | |
1331 | case IPA_CONST: | |
7d0d0ce1 | 1332 | if (!TREE_READONLY (w->symbol.decl)) |
2c06958d | 1333 | { |
7d0d0ce1 | 1334 | warn_function_const (w->symbol.decl, !this_looping); |
2c06958d | 1335 | if (dump_file) |
1336 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
1337 | this_looping ? "looping " : "", | |
1338 | cgraph_node_name (w)); | |
1339 | } | |
7f74ac6b | 1340 | cgraph_set_const_flag (w, true, this_looping); |
b5cebd44 | 1341 | break; |
48e1416a | 1342 | |
b5cebd44 | 1343 | case IPA_PURE: |
7d0d0ce1 | 1344 | if (!DECL_PURE_P (w->symbol.decl)) |
2c06958d | 1345 | { |
7d0d0ce1 | 1346 | warn_function_pure (w->symbol.decl, !this_looping); |
2c06958d | 1347 | if (dump_file) |
1348 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
1349 | this_looping ? "looping " : "", | |
1350 | cgraph_node_name (w)); | |
1351 | } | |
7f74ac6b | 1352 | cgraph_set_pure_flag (w, true, this_looping); |
b5cebd44 | 1353 | break; |
48e1416a | 1354 | |
b5cebd44 | 1355 | default: |
1356 | break; | |
1357 | } | |
7d0d0ce1 | 1358 | w_info = (struct ipa_dfs_info *) w->symbol.aux; |
17b28e52 | 1359 | w = w_info->next_cycle; |
1360 | } | |
1361 | } | |
1362 | ||
7771d558 | 1363 | ipa_free_postorder_info (); |
c0240443 | 1364 | free (order); |
1365 | } | |
1366 | ||
1367 | /* Produce transitive closure over the callgraph and compute nothrow | |
1368 | attributes. */ | |
1369 | ||
1370 | static void | |
1371 | propagate_nothrow (void) | |
1372 | { | |
1373 | struct cgraph_node *node; | |
1374 | struct cgraph_node *w; | |
1375 | struct cgraph_node **order = | |
1376 | XCNEWVEC (struct cgraph_node *, cgraph_n_nodes); | |
1377 | int order_pos; | |
1378 | int i; | |
1379 | struct ipa_dfs_info * w_info; | |
1380 | ||
7771d558 | 1381 | order_pos = ipa_reduced_postorder (order, true, false, ignore_edge); |
17b28e52 | 1382 | if (dump_file) |
1383 | { | |
1384 | dump_cgraph (dump_file); | |
7771d558 | 1385 | ipa_print_order (dump_file, "reduced for nothrow", order, order_pos); |
17b28e52 | 1386 | } |
c0240443 | 1387 | |
9d75589a | 1388 | /* Propagate the local information through the call graph to produce |
17b28e52 | 1389 | the global information. All the nodes within a cycle will have |
1390 | the same info so we collapse cycles first. Then we can do the | |
1391 | propagation in one pass from the leaves to the roots. */ | |
1392 | for (i = 0; i < order_pos; i++ ) | |
1393 | { | |
1394 | bool can_throw = false; | |
1395 | node = order[i]; | |
1396 | ||
15ca8f90 | 1397 | if (node->symbol.alias) |
8c1fce46 | 1398 | continue; |
1399 | ||
17b28e52 | 1400 | /* Find the worst state for any node in the cycle. */ |
1401 | w = node; | |
1402 | while (w) | |
1403 | { | |
023a28e1 | 1404 | struct cgraph_edge *e, *ie; |
17b28e52 | 1405 | funct_state w_l = get_function_state (w); |
1406 | ||
ef378c27 | 1407 | if (w_l->can_throw |
1408 | || cgraph_function_body_availability (w) == AVAIL_OVERWRITABLE) | |
17b28e52 | 1409 | can_throw = true; |
1410 | ||
1411 | if (can_throw) | |
1412 | break; | |
48e1416a | 1413 | |
1414 | for (e = w->callees; e; e = e->next_callee) | |
17b28e52 | 1415 | { |
b2c2e188 | 1416 | enum availability avail; |
1417 | struct cgraph_node *y = cgraph_function_node (e->callee, &avail); | |
17b28e52 | 1418 | |
b2c2e188 | 1419 | if (avail > AVAIL_OVERWRITABLE) |
17b28e52 | 1420 | { |
1421 | funct_state y_l = get_function_state (y); | |
1422 | ||
48e1416a | 1423 | if (can_throw) |
17b28e52 | 1424 | break; |
7d0d0ce1 | 1425 | if (y_l->can_throw && !TREE_NOTHROW (w->symbol.decl) |
17b28e52 | 1426 | && e->can_throw_external) |
1427 | can_throw = true; | |
1428 | } | |
7d0d0ce1 | 1429 | else if (e->can_throw_external && !TREE_NOTHROW (y->symbol.decl)) |
ef378c27 | 1430 | can_throw = true; |
17b28e52 | 1431 | } |
023a28e1 | 1432 | for (ie = node->indirect_calls; ie; ie = ie->next_callee) |
1433 | if (ie->can_throw_external) | |
73bd65ab | 1434 | { |
1435 | can_throw = true; | |
1436 | break; | |
1437 | } | |
7d0d0ce1 | 1438 | w_info = (struct ipa_dfs_info *) w->symbol.aux; |
17b28e52 | 1439 | w = w_info->next_cycle; |
1440 | } | |
1441 | ||
1442 | /* Copy back the region's pure_const_state which is shared by | |
1443 | all nodes in the region. */ | |
1444 | w = node; | |
1445 | while (w) | |
1446 | { | |
ecfab407 | 1447 | funct_state w_l = get_function_state (w); |
7d0d0ce1 | 1448 | if (!can_throw && !TREE_NOTHROW (w->symbol.decl)) |
b5cebd44 | 1449 | { |
16fcf0f4 | 1450 | cgraph_set_nothrow_flag (w, true); |
b5cebd44 | 1451 | if (dump_file) |
48e1416a | 1452 | fprintf (dump_file, "Function found to be nothrow: %s\n", |
b5cebd44 | 1453 | cgraph_node_name (w)); |
f7d118a9 | 1454 | } |
7d0d0ce1 | 1455 | else if (can_throw && !TREE_NOTHROW (w->symbol.decl)) |
ecfab407 | 1456 | w_l->can_throw = true; |
7d0d0ce1 | 1457 | w_info = (struct ipa_dfs_info *) w->symbol.aux; |
f7d118a9 | 1458 | w = w_info->next_cycle; |
1459 | } | |
1460 | } | |
1461 | ||
7771d558 | 1462 | ipa_free_postorder_info (); |
f7d118a9 | 1463 | free (order); |
c0240443 | 1464 | } |
1465 | ||
1466 | ||
1467 | /* Produce the global information by preforming a transitive closure | |
1468 | on the local information that was produced by generate_summary. */ | |
1469 | ||
1470 | static unsigned int | |
1471 | propagate (void) | |
1472 | { | |
1473 | struct cgraph_node *node; | |
1474 | ||
1475 | cgraph_remove_function_insertion_hook (function_insertion_hook_holder); | |
1476 | cgraph_remove_node_duplication_hook (node_duplication_hook_holder); | |
1477 | cgraph_remove_node_removal_hook (node_removal_hook_holder); | |
1478 | ||
1479 | /* Nothrow makes more function to not lead to return and improve | |
1480 | later analysis. */ | |
1481 | propagate_nothrow (); | |
1482 | propagate_pure_const (); | |
1483 | ||
1484 | /* Cleanup. */ | |
c6d207aa | 1485 | FOR_EACH_FUNCTION (node) |
c0240443 | 1486 | if (has_function_state (node)) |
1487 | free (get_function_state (node)); | |
f1f41a6c | 1488 | funct_state_vec.release (); |
cb886925 | 1489 | finish_state (); |
2a1990e9 | 1490 | return 0; |
f7d118a9 | 1491 | } |
1492 | ||
1493 | static bool | |
1494 | gate_pure_const (void) | |
1495 | { | |
86844d6c | 1496 | return (flag_ipa_pure_const |
f7d118a9 | 1497 | /* Don't bother doing anything if the program has errors. */ |
852f689e | 1498 | && !seen_error ()); |
f7d118a9 | 1499 | } |
1500 | ||
cbe8bda8 | 1501 | namespace { |
1502 | ||
1503 | const pass_data pass_data_ipa_pure_const = | |
f7d118a9 | 1504 | { |
cbe8bda8 | 1505 | IPA_PASS, /* type */ |
1506 | "pure-const", /* name */ | |
1507 | OPTGROUP_NONE, /* optinfo_flags */ | |
1508 | true, /* has_gate */ | |
1509 | true, /* has_execute */ | |
1510 | TV_IPA_PURE_CONST, /* tv_id */ | |
1511 | 0, /* properties_required */ | |
1512 | 0, /* properties_provided */ | |
1513 | 0, /* properties_destroyed */ | |
1514 | 0, /* todo_flags_start */ | |
1515 | 0, /* todo_flags_finish */ | |
f7d118a9 | 1516 | }; |
b5cebd44 | 1517 | |
cbe8bda8 | 1518 | class pass_ipa_pure_const : public ipa_opt_pass_d |
1519 | { | |
1520 | public: | |
1521 | pass_ipa_pure_const(gcc::context *ctxt) | |
1522 | : ipa_opt_pass_d(pass_data_ipa_pure_const, ctxt, | |
1523 | pure_const_generate_summary, /* generate_summary */ | |
1524 | pure_const_write_summary, /* write_summary */ | |
1525 | pure_const_read_summary, /* read_summary */ | |
1526 | NULL, /* write_optimization_summary */ | |
1527 | NULL, /* read_optimization_summary */ | |
1528 | NULL, /* stmt_fixup */ | |
1529 | 0, /* function_transform_todo_flags_start */ | |
1530 | NULL, /* function_transform */ | |
1531 | NULL) /* variable_transform */ | |
1532 | {} | |
1533 | ||
1534 | /* opt_pass methods: */ | |
1535 | bool gate () { return gate_pure_const (); } | |
1536 | unsigned int execute () { return propagate (); } | |
1537 | ||
1538 | }; // class pass_ipa_pure_const | |
1539 | ||
1540 | } // anon namespace | |
1541 | ||
1542 | ipa_opt_pass_d * | |
1543 | make_pass_ipa_pure_const (gcc::context *ctxt) | |
1544 | { | |
1545 | return new pass_ipa_pure_const (ctxt); | |
1546 | } | |
1547 | ||
2c06958d | 1548 | /* Return true if function should be skipped for local pure const analysis. */ |
b5cebd44 | 1549 | |
2c06958d | 1550 | static bool |
1551 | skip_function_for_local_pure_const (struct cgraph_node *node) | |
b5cebd44 | 1552 | { |
b5cebd44 | 1553 | /* Because we do not schedule pass_fixup_cfg over whole program after early optimizations |
1554 | we must not promote functions that are called by already processed functions. */ | |
1555 | ||
1556 | if (function_called_by_processed_nodes_p ()) | |
1557 | { | |
1558 | if (dump_file) | |
1559 | fprintf (dump_file, "Function called in recursive cycle; ignoring\n"); | |
2c06958d | 1560 | return true; |
b5cebd44 | 1561 | } |
16fcf0f4 | 1562 | if (cgraph_function_body_availability (node) <= AVAIL_OVERWRITABLE) |
b5cebd44 | 1563 | { |
1564 | if (dump_file) | |
0a10fd82 | 1565 | fprintf (dump_file, "Function is not available or overwritable; not analyzing.\n"); |
2c06958d | 1566 | return true; |
b5cebd44 | 1567 | } |
2c06958d | 1568 | return false; |
1569 | } | |
1570 | ||
1571 | /* Simple local pass for pure const discovery reusing the analysis from | |
1572 | ipa_pure_const. This pass is effective when executed together with | |
1573 | other optimization passes in early optimization pass queue. */ | |
b5cebd44 | 1574 | |
2c06958d | 1575 | static unsigned int |
1576 | local_pure_const (void) | |
1577 | { | |
1578 | bool changed = false; | |
1579 | funct_state l; | |
1580 | bool skip; | |
1581 | struct cgraph_node *node; | |
1582 | ||
fd6a3c41 | 1583 | node = cgraph_get_node (current_function_decl); |
2c06958d | 1584 | skip = skip_function_for_local_pure_const (node); |
1585 | if (!warn_suggest_attribute_const | |
1586 | && !warn_suggest_attribute_pure | |
1587 | && skip) | |
1588 | return 0; | |
e0933141 | 1589 | |
ab3db708 | 1590 | l = analyze_function (node, false); |
1591 | ||
1592 | /* Do NORETURN discovery. */ | |
e0933141 | 1593 | if (!skip && !TREE_THIS_VOLATILE (current_function_decl) |
1594 | && EDGE_COUNT (EXIT_BLOCK_PTR->preds) == 0) | |
1595 | { | |
43d60d64 | 1596 | warn_function_noreturn (cfun->decl); |
e0933141 | 1597 | if (dump_file) |
1598 | fprintf (dump_file, "Function found to be noreturn: %s\n", | |
9631926a | 1599 | current_function_name ()); |
e0933141 | 1600 | |
1601 | /* Update declaration and reduce profile to executed once. */ | |
1602 | TREE_THIS_VOLATILE (current_function_decl) = 1; | |
1603 | if (node->frequency > NODE_FREQUENCY_EXECUTED_ONCE) | |
1604 | node->frequency = NODE_FREQUENCY_EXECUTED_ONCE; | |
1605 | ||
1606 | changed = true; | |
1607 | } | |
ef378c27 | 1608 | |
b5cebd44 | 1609 | switch (l->pure_const_state) |
1610 | { | |
1611 | case IPA_CONST: | |
1612 | if (!TREE_READONLY (current_function_decl)) | |
1613 | { | |
2c06958d | 1614 | warn_function_const (current_function_decl, !l->looping); |
1615 | if (!skip) | |
1616 | { | |
7f74ac6b | 1617 | cgraph_set_const_flag (node, true, l->looping); |
2c06958d | 1618 | changed = true; |
1619 | } | |
b5cebd44 | 1620 | if (dump_file) |
1621 | fprintf (dump_file, "Function found to be %sconst: %s\n", | |
1622 | l->looping ? "looping " : "", | |
9631926a | 1623 | current_function_name ()); |
b5cebd44 | 1624 | } |
1625 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
1626 | && !l->looping) | |
1627 | { | |
2c06958d | 1628 | if (!skip) |
1629 | { | |
7f74ac6b | 1630 | cgraph_set_const_flag (node, true, false); |
2c06958d | 1631 | changed = true; |
1632 | } | |
b5cebd44 | 1633 | if (dump_file) |
1634 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 1635 | current_function_name ()); |
b5cebd44 | 1636 | } |
1637 | break; | |
1638 | ||
1639 | case IPA_PURE: | |
2c06958d | 1640 | if (!DECL_PURE_P (current_function_decl)) |
b5cebd44 | 1641 | { |
2c06958d | 1642 | if (!skip) |
1643 | { | |
7f74ac6b | 1644 | cgraph_set_pure_flag (node, true, l->looping); |
2c06958d | 1645 | changed = true; |
1646 | } | |
1647 | warn_function_pure (current_function_decl, !l->looping); | |
b5cebd44 | 1648 | if (dump_file) |
1649 | fprintf (dump_file, "Function found to be %spure: %s\n", | |
1650 | l->looping ? "looping " : "", | |
9631926a | 1651 | current_function_name ()); |
b5cebd44 | 1652 | } |
1653 | else if (DECL_LOOPING_CONST_OR_PURE_P (current_function_decl) | |
1654 | && !l->looping) | |
1655 | { | |
2c06958d | 1656 | if (!skip) |
1657 | { | |
7f74ac6b | 1658 | cgraph_set_pure_flag (node, true, false); |
2c06958d | 1659 | changed = true; |
1660 | } | |
b5cebd44 | 1661 | if (dump_file) |
1662 | fprintf (dump_file, "Function found to be non-looping: %s\n", | |
9631926a | 1663 | current_function_name ()); |
b5cebd44 | 1664 | } |
1665 | break; | |
1666 | ||
1667 | default: | |
1668 | break; | |
1669 | } | |
1670 | if (!l->can_throw && !TREE_NOTHROW (current_function_decl)) | |
1671 | { | |
16fcf0f4 | 1672 | cgraph_set_nothrow_flag (node, true); |
b5cebd44 | 1673 | changed = true; |
1674 | if (dump_file) | |
1675 | fprintf (dump_file, "Function found to be nothrow: %s\n", | |
9631926a | 1676 | current_function_name ()); |
b5cebd44 | 1677 | } |
dd045aee | 1678 | free (l); |
b5cebd44 | 1679 | if (changed) |
1680 | return execute_fixup_cfg (); | |
1681 | else | |
1682 | return 0; | |
1683 | } | |
1684 | ||
cbe8bda8 | 1685 | namespace { |
1686 | ||
1687 | const pass_data pass_data_local_pure_const = | |
b5cebd44 | 1688 | { |
cbe8bda8 | 1689 | GIMPLE_PASS, /* type */ |
1690 | "local-pure-const", /* name */ | |
1691 | OPTGROUP_NONE, /* optinfo_flags */ | |
1692 | true, /* has_gate */ | |
1693 | true, /* has_execute */ | |
1694 | TV_IPA_PURE_CONST, /* tv_id */ | |
1695 | 0, /* properties_required */ | |
1696 | 0, /* properties_provided */ | |
1697 | 0, /* properties_destroyed */ | |
1698 | 0, /* todo_flags_start */ | |
1699 | 0, /* todo_flags_finish */ | |
b5cebd44 | 1700 | }; |
cbe8bda8 | 1701 | |
1702 | class pass_local_pure_const : public gimple_opt_pass | |
1703 | { | |
1704 | public: | |
1705 | pass_local_pure_const(gcc::context *ctxt) | |
1706 | : gimple_opt_pass(pass_data_local_pure_const, ctxt) | |
1707 | {} | |
1708 | ||
1709 | /* opt_pass methods: */ | |
1710 | opt_pass * clone () { return new pass_local_pure_const (ctxt_); } | |
1711 | bool gate () { return gate_pure_const (); } | |
1712 | unsigned int execute () { return local_pure_const (); } | |
1713 | ||
1714 | }; // class pass_local_pure_const | |
1715 | ||
1716 | } // anon namespace | |
1717 | ||
1718 | gimple_opt_pass * | |
1719 | make_pass_local_pure_const (gcc::context *ctxt) | |
1720 | { | |
1721 | return new pass_local_pure_const (ctxt); | |
1722 | } |