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fee8b6da JH |
1 | /* Callgraph transformations to handle inlining |
2 | Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010, 2011 | |
3 | Free Software Foundation, Inc. | |
4 | Contributed by Jan Hubicka | |
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 | |
10 | Software Foundation; either version 3, or (at your option) any later | |
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 | |
19 | along with GCC; see the file COPYING3. If not see | |
20 | <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | /* The inline decisions are stored in callgraph in "inline plan" and | |
23 | applied later. | |
24 | ||
25 | To mark given call inline, use inline_call function. | |
26 | The function marks the edge inlinable and, if necessary, produces | |
27 | virtual clone in the callgraph representing the new copy of callee's | |
28 | function body. | |
29 | ||
30 | The inline plan is applied on given function body by inline_transform. */ | |
31 | ||
32 | #include "config.h" | |
33 | #include "system.h" | |
34 | #include "coretypes.h" | |
35 | #include "tm.h" | |
36 | #include "tree.h" | |
37 | #include "langhooks.h" | |
38 | #include "cgraph.h" | |
39 | #include "timevar.h" | |
40 | #include "output.h" | |
41 | #include "intl.h" | |
42 | #include "coverage.h" | |
43 | #include "ggc.h" | |
44 | #include "tree-flow.h" | |
45 | #include "ipa-prop.h" | |
46 | #include "ipa-inline.h" | |
47 | #include "tree-inline.h" | |
516e0768 | 48 | #include "tree-pass.h" |
fee8b6da JH |
49 | |
50 | int ncalls_inlined; | |
51 | int nfunctions_inlined; | |
52 | ||
898b8927 | 53 | /* Scale frequency of NODE edges by FREQ_SCALE. */ |
fee8b6da JH |
54 | |
55 | static void | |
56 | update_noncloned_frequencies (struct cgraph_node *node, | |
898b8927 | 57 | int freq_scale) |
fee8b6da JH |
58 | { |
59 | struct cgraph_edge *e; | |
60 | ||
61 | /* We do not want to ignore high loop nest after freq drops to 0. */ | |
62 | if (!freq_scale) | |
63 | freq_scale = 1; | |
64 | for (e = node->callees; e; e = e->next_callee) | |
65 | { | |
fee8b6da JH |
66 | e->frequency = e->frequency * (gcov_type) freq_scale / CGRAPH_FREQ_BASE; |
67 | if (e->frequency > CGRAPH_FREQ_MAX) | |
68 | e->frequency = CGRAPH_FREQ_MAX; | |
69 | if (!e->inline_failed) | |
898b8927 JH |
70 | update_noncloned_frequencies (e->callee, freq_scale); |
71 | } | |
72 | for (e = node->indirect_calls; e; e = e->next_callee) | |
73 | { | |
74 | e->frequency = e->frequency * (gcov_type) freq_scale / CGRAPH_FREQ_BASE; | |
75 | if (e->frequency > CGRAPH_FREQ_MAX) | |
76 | e->frequency = CGRAPH_FREQ_MAX; | |
fee8b6da JH |
77 | } |
78 | } | |
79 | ||
a5b1779f JH |
80 | /* We removed or are going to remove the last call to NODE. |
81 | Return true if we can and want proactively remove the NODE now. | |
82 | This is important to do, since we want inliner to know when offline | |
83 | copy of function was removed. */ | |
84 | ||
85 | static bool | |
6c69a029 | 86 | can_remove_node_now_p_1 (struct cgraph_node *node) |
a5b1779f JH |
87 | { |
88 | /* FIXME: When address is taken of DECL_EXTERNAL function we still | |
89 | can remove its offline copy, but we would need to keep unanalyzed node in | |
90 | the callgraph so references can point to it. */ | |
960bfb69 JH |
91 | return (!node->symbol.address_taken |
92 | && !ipa_ref_has_aliases_p (&node->symbol.ref_list) | |
a5b1779f JH |
93 | && cgraph_can_remove_if_no_direct_calls_p (node) |
94 | /* Inlining might enable more devirtualizing, so we want to remove | |
95 | those only after all devirtualizable virtual calls are processed. | |
96 | Lacking may edges in callgraph we just preserve them post | |
97 | inlining. */ | |
960bfb69 JH |
98 | && (!DECL_VIRTUAL_P (node->symbol.decl) |
99 | || (!DECL_COMDAT (node->symbol.decl) | |
100 | && !DECL_EXTERNAL (node->symbol.decl))) | |
a5b1779f JH |
101 | /* During early inlining some unanalyzed cgraph nodes might be in the |
102 | callgraph and they might reffer the function in question. */ | |
103 | && !cgraph_new_nodes); | |
104 | } | |
105 | ||
6c69a029 JH |
106 | /* We are going to eliminate last direct call to NODE (or alias of it) via edge E. |
107 | Verify that the NODE can be removed from unit and if it is contained in comdat | |
108 | group that the whole comdat group is removable. */ | |
109 | ||
110 | static bool | |
111 | can_remove_node_now_p (struct cgraph_node *node, struct cgraph_edge *e) | |
112 | { | |
113 | struct cgraph_node *next; | |
114 | if (!can_remove_node_now_p_1 (node)) | |
115 | return false; | |
116 | ||
117 | /* When we see same comdat group, we need to be sure that all | |
118 | items can be removed. */ | |
960bfb69 | 119 | if (!node->symbol.same_comdat_group) |
6c69a029 | 120 | return true; |
960bfb69 JH |
121 | for (next = cgraph (node->symbol.same_comdat_group); |
122 | next != node; next = cgraph (next->symbol.same_comdat_group)) | |
aa74f081 JH |
123 | if ((next->callers && next->callers != e) |
124 | || !can_remove_node_now_p_1 (next)) | |
6c69a029 JH |
125 | return false; |
126 | return true; | |
127 | } | |
128 | ||
fee8b6da JH |
129 | |
130 | /* E is expected to be an edge being inlined. Clone destination node of | |
131 | the edge and redirect it to the new clone. | |
132 | DUPLICATE is used for bookkeeping on whether we are actually creating new | |
133 | clones or re-using node originally representing out-of-line function call. | |
134 | */ | |
135 | ||
136 | void | |
137 | clone_inlined_nodes (struct cgraph_edge *e, bool duplicate, | |
138 | bool update_original, int *overall_size) | |
139 | { | |
fee8b6da JH |
140 | if (duplicate) |
141 | { | |
142 | /* We may eliminate the need for out-of-line copy to be output. | |
143 | In that case just go ahead and re-use it. This is not just an | |
144 | memory optimization. Making offline copy of fuction disappear | |
145 | from the program will improve future decisions on inlining. */ | |
146 | if (!e->callee->callers->next_caller | |
147 | /* Recursive inlining never wants the master clone to | |
148 | be overwritten. */ | |
149 | && update_original | |
6c69a029 | 150 | && can_remove_node_now_p (e->callee, e)) |
fee8b6da | 151 | { |
6c69a029 JH |
152 | /* TODO: When callee is in a comdat group, we could remove all of it, |
153 | including all inline clones inlined into it. That would however | |
154 | need small function inlining to register edge removal hook to | |
155 | maintain the priority queue. | |
156 | ||
157 | For now we keep the ohter functions in the group in program until | |
158 | cgraph_remove_unreachable_functions gets rid of them. */ | |
fee8b6da | 159 | gcc_assert (!e->callee->global.inlined_to); |
960bfb69 | 160 | if (e->callee->analyzed && !DECL_EXTERNAL (e->callee->symbol.decl)) |
fee8b6da JH |
161 | { |
162 | if (overall_size) | |
163 | *overall_size -= inline_summary (e->callee)->size; | |
164 | nfunctions_inlined++; | |
165 | } | |
166 | duplicate = false; | |
960bfb69 | 167 | e->callee->symbol.externally_visible = false; |
898b8927 | 168 | update_noncloned_frequencies (e->callee, e->frequency); |
fee8b6da JH |
169 | } |
170 | else | |
171 | { | |
172 | struct cgraph_node *n; | |
960bfb69 | 173 | n = cgraph_clone_node (e->callee, e->callee->symbol.decl, |
898b8927 | 174 | e->count, e->frequency, |
74605a11 | 175 | update_original, NULL, true); |
fee8b6da JH |
176 | cgraph_redirect_edge_callee (e, n); |
177 | } | |
178 | } | |
179 | ||
fee8b6da JH |
180 | if (e->caller->global.inlined_to) |
181 | e->callee->global.inlined_to = e->caller->global.inlined_to; | |
182 | else | |
183 | e->callee->global.inlined_to = e->caller; | |
fee8b6da JH |
184 | |
185 | /* Recursively clone all bodies. */ | |
186 | for (e = e->callee->callees; e; e = e->next_callee) | |
187 | if (!e->inline_failed) | |
188 | clone_inlined_nodes (e, duplicate, update_original, overall_size); | |
189 | } | |
190 | ||
191 | ||
192 | /* Mark edge E as inlined and update callgraph accordingly. UPDATE_ORIGINAL | |
193 | specify whether profile of original function should be updated. If any new | |
194 | indirect edges are discovered in the process, add them to NEW_EDGES, unless | |
195 | it is NULL. Return true iff any new callgraph edges were discovered as a | |
196 | result of inlining. */ | |
197 | ||
198 | bool | |
199 | inline_call (struct cgraph_edge *e, bool update_original, | |
200 | VEC (cgraph_edge_p, heap) **new_edges, | |
201 | int *overall_size) | |
202 | { | |
203 | int old_size = 0, new_size = 0; | |
204 | struct cgraph_node *to = NULL; | |
205 | struct cgraph_edge *curr = e; | |
a5b1779f | 206 | struct cgraph_node *callee = cgraph_function_or_thunk_node (e->callee, NULL); |
fee8b6da JH |
207 | |
208 | /* Don't inline inlined edges. */ | |
209 | gcc_assert (e->inline_failed); | |
210 | /* Don't even think of inlining inline clone. */ | |
a5b1779f | 211 | gcc_assert (!callee->global.inlined_to); |
fee8b6da JH |
212 | |
213 | e->inline_failed = CIF_OK; | |
960bfb69 | 214 | DECL_POSSIBLY_INLINED (callee->symbol.decl) = true; |
fee8b6da | 215 | |
632b4f8e JH |
216 | to = e->caller; |
217 | if (to->global.inlined_to) | |
218 | to = to->global.inlined_to; | |
632b4f8e | 219 | |
a5b1779f JH |
220 | /* If aliases are involved, redirect edge to the actual destination and |
221 | possibly remove the aliases. */ | |
222 | if (e->callee != callee) | |
39e2db00 JH |
223 | { |
224 | struct cgraph_node *alias = e->callee, *next_alias; | |
225 | cgraph_redirect_edge_callee (e, callee); | |
226 | while (alias && alias != callee) | |
227 | { | |
228 | if (!alias->callers | |
6c69a029 | 229 | && can_remove_node_now_p (alias, e)) |
39e2db00 JH |
230 | { |
231 | next_alias = cgraph_alias_aliased_node (alias); | |
232 | cgraph_remove_node (alias); | |
233 | alias = next_alias; | |
234 | } | |
235 | else | |
236 | break; | |
237 | } | |
238 | } | |
a5b1779f | 239 | |
fee8b6da JH |
240 | clone_inlined_nodes (e, true, update_original, overall_size); |
241 | ||
fee8b6da | 242 | gcc_assert (curr->callee->global.inlined_to == to); |
898b8927 JH |
243 | |
244 | old_size = inline_summary (to)->size; | |
245 | inline_merge_summary (e); | |
246 | new_size = inline_summary (to)->size; | |
b4c0a884 | 247 | if (overall_size) |
fee8b6da JH |
248 | *overall_size += new_size - old_size; |
249 | ncalls_inlined++; | |
250 | ||
25837a2f JH |
251 | /* This must happen after inline_merge_summary that rely on jump |
252 | functions of callee to not be updated. */ | |
5ee53a06 | 253 | if (optimize) |
fee8b6da JH |
254 | return ipa_propagate_indirect_call_infos (curr, new_edges); |
255 | else | |
256 | return false; | |
257 | } | |
258 | ||
259 | ||
260 | /* Copy function body of NODE and redirect all inline clones to it. | |
261 | This is done before inline plan is applied to NODE when there are | |
262 | still some inline clones if it. | |
263 | ||
264 | This is neccesary because inline decisions are not really transitive | |
265 | and the other inline clones may have different bodies. */ | |
266 | ||
267 | static struct cgraph_node * | |
268 | save_inline_function_body (struct cgraph_node *node) | |
269 | { | |
270 | struct cgraph_node *first_clone, *n; | |
271 | ||
272 | if (dump_file) | |
273 | fprintf (dump_file, "\nSaving body of %s for later reuse\n", | |
274 | cgraph_node_name (node)); | |
275 | ||
960bfb69 | 276 | gcc_assert (node == cgraph_get_node (node->symbol.decl)); |
fee8b6da JH |
277 | |
278 | /* first_clone will be turned into real function. */ | |
279 | first_clone = node->clones; | |
960bfb69 | 280 | first_clone->symbol.decl = copy_node (node->symbol.decl); |
1ab24192 | 281 | symtab_insert_node_to_hashtable ((symtab_node) first_clone); |
960bfb69 | 282 | gcc_assert (first_clone == cgraph_get_node (first_clone->symbol.decl)); |
fee8b6da JH |
283 | |
284 | /* Now reshape the clone tree, so all other clones descends from | |
285 | first_clone. */ | |
286 | if (first_clone->next_sibling_clone) | |
287 | { | |
288 | for (n = first_clone->next_sibling_clone; n->next_sibling_clone; n = n->next_sibling_clone) | |
289 | n->clone_of = first_clone; | |
290 | n->clone_of = first_clone; | |
291 | n->next_sibling_clone = first_clone->clones; | |
292 | if (first_clone->clones) | |
293 | first_clone->clones->prev_sibling_clone = n; | |
294 | first_clone->clones = first_clone->next_sibling_clone; | |
295 | first_clone->next_sibling_clone->prev_sibling_clone = NULL; | |
296 | first_clone->next_sibling_clone = NULL; | |
297 | gcc_assert (!first_clone->prev_sibling_clone); | |
298 | } | |
299 | first_clone->clone_of = NULL; | |
300 | ||
301 | /* Now node in question has no clones. */ | |
302 | node->clones = NULL; | |
303 | ||
1a3118e9 JH |
304 | /* Inline clones share decl with the function they are cloned |
305 | from. Walk the whole clone tree and redirect them all to the | |
306 | new decl. */ | |
fee8b6da JH |
307 | if (first_clone->clones) |
308 | for (n = first_clone->clones; n != first_clone;) | |
309 | { | |
960bfb69 JH |
310 | gcc_assert (n->symbol.decl == node->symbol.decl); |
311 | n->symbol.decl = first_clone->symbol.decl; | |
fee8b6da JH |
312 | if (n->clones) |
313 | n = n->clones; | |
314 | else if (n->next_sibling_clone) | |
315 | n = n->next_sibling_clone; | |
316 | else | |
317 | { | |
318 | while (n != first_clone && !n->next_sibling_clone) | |
319 | n = n->clone_of; | |
320 | if (n != first_clone) | |
321 | n = n->next_sibling_clone; | |
322 | } | |
323 | } | |
324 | ||
325 | /* Copy the OLD_VERSION_NODE function tree to the new version. */ | |
960bfb69 JH |
326 | tree_function_versioning (node->symbol.decl, first_clone->symbol.decl, |
327 | NULL, true, NULL, false, NULL, NULL); | |
fee8b6da | 328 | |
1a3118e9 JH |
329 | /* The function will be short lived and removed after we inline all the clones, |
330 | but make it internal so we won't confuse ourself. */ | |
960bfb69 JH |
331 | DECL_EXTERNAL (first_clone->symbol.decl) = 0; |
332 | DECL_COMDAT_GROUP (first_clone->symbol.decl) = NULL_TREE; | |
333 | TREE_PUBLIC (first_clone->symbol.decl) = 0; | |
334 | DECL_COMDAT (first_clone->symbol.decl) = 0; | |
fee8b6da JH |
335 | VEC_free (ipa_opt_pass, heap, |
336 | first_clone->ipa_transforms_to_apply); | |
337 | first_clone->ipa_transforms_to_apply = NULL; | |
338 | ||
b4e93f45 JH |
339 | /* When doing recursive inlining, the clone may become unnecessary. |
340 | This is possible i.e. in the case when the recursive function is proved to be | |
341 | non-throwing and the recursion happens only in the EH landing pad. | |
342 | We can not remove the clone until we are done with saving the body. | |
343 | Remove it now. */ | |
344 | if (!first_clone->callers) | |
345 | { | |
346 | cgraph_remove_node_and_inline_clones (first_clone, NULL); | |
347 | first_clone = NULL; | |
348 | } | |
fee8b6da | 349 | #ifdef ENABLE_CHECKING |
b4e93f45 JH |
350 | else |
351 | verify_cgraph_node (first_clone); | |
fee8b6da JH |
352 | #endif |
353 | return first_clone; | |
354 | } | |
355 | ||
356 | ||
357 | /* Apply inline plan to function. */ | |
358 | ||
359 | unsigned int | |
360 | inline_transform (struct cgraph_node *node) | |
361 | { | |
362 | unsigned int todo = 0; | |
363 | struct cgraph_edge *e; | |
c9fc06dc | 364 | |
fee8b6da JH |
365 | /* FIXME: Currently the pass manager is adding inline transform more than |
366 | once to some clones. This needs revisiting after WPA cleanups. */ | |
367 | if (cfun->after_inlining) | |
368 | return 0; | |
369 | ||
370 | /* We might need the body of this function so that we can expand | |
371 | it inline somewhere else. */ | |
85ad2ef5 | 372 | if (cgraph_preserve_function_body_p (node)) |
fee8b6da JH |
373 | save_inline_function_body (node); |
374 | ||
375 | for (e = node->callees; e; e = e->next_callee) | |
c9fc06dc CB |
376 | cgraph_redirect_edge_call_stmt_to_callee (e); |
377 | ||
378 | timevar_push (TV_INTEGRATION); | |
379 | if (node->callees) | |
55f01229 | 380 | todo = optimize_inline_calls (current_function_decl); |
c9fc06dc CB |
381 | timevar_pop (TV_INTEGRATION); |
382 | ||
f8698b37 RG |
383 | cfun->always_inline_functions_inlined = true; |
384 | cfun->after_inlining = true; | |
385 | todo |= execute_fixup_cfg (); | |
386 | ||
55f01229 RG |
387 | if (!(todo & TODO_update_ssa_any)) |
388 | /* Redirecting edges might lead to a need for vops to be recomputed. */ | |
389 | todo |= TODO_update_ssa_only_virtuals; | |
390 | ||
f8698b37 | 391 | return todo; |
fee8b6da | 392 | } |