1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
|
/* Callgraph transformations to handle inlining
Copyright (C) 2003, 2004, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
Contributed by Jan Hubicka
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
/* The inline decisions are stored in callgraph in "inline plan" and
applied later.
To mark given call inline, use inline_call function.
The function marks the edge inlinable and, if necessary, produces
virtual clone in the callgraph representing the new copy of callee's
function body.
The inline plan is applied on given function body by inline_transform. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "langhooks.h"
#include "cgraph.h"
#include "timevar.h"
#include "output.h"
#include "intl.h"
#include "coverage.h"
#include "ggc.h"
#include "tree-flow.h"
#include "ipa-prop.h"
#include "ipa-inline.h"
#include "tree-inline.h"
#include "tree-pass.h"
int ncalls_inlined;
int nfunctions_inlined;
/* Scale frequency of NODE edges by FREQ_SCALE. */
static void
update_noncloned_frequencies (struct cgraph_node *node,
int freq_scale)
{
struct cgraph_edge *e;
/* We do not want to ignore high loop nest after freq drops to 0. */
if (!freq_scale)
freq_scale = 1;
for (e = node->callees; e; e = e->next_callee)
{
e->frequency = e->frequency * (gcov_type) freq_scale / CGRAPH_FREQ_BASE;
if (e->frequency > CGRAPH_FREQ_MAX)
e->frequency = CGRAPH_FREQ_MAX;
if (!e->inline_failed)
update_noncloned_frequencies (e->callee, freq_scale);
}
for (e = node->indirect_calls; e; e = e->next_callee)
{
e->frequency = e->frequency * (gcov_type) freq_scale / CGRAPH_FREQ_BASE;
if (e->frequency > CGRAPH_FREQ_MAX)
e->frequency = CGRAPH_FREQ_MAX;
}
}
/* We removed or are going to remove the last call to NODE.
Return true if we can and want proactively remove the NODE now.
This is important to do, since we want inliner to know when offline
copy of function was removed. */
static bool
can_remove_node_now_p_1 (struct cgraph_node *node)
{
/* FIXME: When address is taken of DECL_EXTERNAL function we still
can remove its offline copy, but we would need to keep unanalyzed node in
the callgraph so references can point to it. */
return (!node->address_taken
&& !ipa_ref_has_aliases_p (&node->ref_list)
&& cgraph_can_remove_if_no_direct_calls_p (node)
/* Inlining might enable more devirtualizing, so we want to remove
those only after all devirtualizable virtual calls are processed.
Lacking may edges in callgraph we just preserve them post
inlining. */
&& (!DECL_VIRTUAL_P (node->decl)
|| (!DECL_COMDAT (node->decl)
&& !DECL_EXTERNAL (node->decl)))
/* During early inlining some unanalyzed cgraph nodes might be in the
callgraph and they might reffer the function in question. */
&& !cgraph_new_nodes);
}
/* We are going to eliminate last direct call to NODE (or alias of it) via edge E.
Verify that the NODE can be removed from unit and if it is contained in comdat
group that the whole comdat group is removable. */
static bool
can_remove_node_now_p (struct cgraph_node *node, struct cgraph_edge *e)
{
struct cgraph_node *next;
if (!can_remove_node_now_p_1 (node))
return false;
/* When we see same comdat group, we need to be sure that all
items can be removed. */
if (!node->same_comdat_group)
return true;
for (next = node->same_comdat_group;
next != node; next = next->same_comdat_group)
if ((next->callers && next->callers != e)
|| !can_remove_node_now_p_1 (next))
return false;
return true;
}
/* E is expected to be an edge being inlined. Clone destination node of
the edge and redirect it to the new clone.
DUPLICATE is used for bookkeeping on whether we are actually creating new
clones or re-using node originally representing out-of-line function call.
*/
void
clone_inlined_nodes (struct cgraph_edge *e, bool duplicate,
bool update_original, int *overall_size)
{
if (duplicate)
{
/* We may eliminate the need for out-of-line copy to be output.
In that case just go ahead and re-use it. This is not just an
memory optimization. Making offline copy of fuction disappear
from the program will improve future decisions on inlining. */
if (!e->callee->callers->next_caller
/* Recursive inlining never wants the master clone to
be overwritten. */
&& update_original
&& can_remove_node_now_p (e->callee, e))
{
/* TODO: When callee is in a comdat group, we could remove all of it,
including all inline clones inlined into it. That would however
need small function inlining to register edge removal hook to
maintain the priority queue.
For now we keep the ohter functions in the group in program until
cgraph_remove_unreachable_functions gets rid of them. */
gcc_assert (!e->callee->global.inlined_to);
if (e->callee->analyzed && !DECL_EXTERNAL (e->callee->decl))
{
if (overall_size)
*overall_size -= inline_summary (e->callee)->size;
nfunctions_inlined++;
}
duplicate = false;
e->callee->local.externally_visible = false;
update_noncloned_frequencies (e->callee, e->frequency);
}
else
{
struct cgraph_node *n;
n = cgraph_clone_node (e->callee, e->callee->decl,
e->count, e->frequency,
update_original, NULL, true);
cgraph_redirect_edge_callee (e, n);
}
}
if (e->caller->global.inlined_to)
e->callee->global.inlined_to = e->caller->global.inlined_to;
else
e->callee->global.inlined_to = e->caller;
/* Recursively clone all bodies. */
for (e = e->callee->callees; e; e = e->next_callee)
if (!e->inline_failed)
clone_inlined_nodes (e, duplicate, update_original, overall_size);
}
/* Mark edge E as inlined and update callgraph accordingly. UPDATE_ORIGINAL
specify whether profile of original function should be updated. If any new
indirect edges are discovered in the process, add them to NEW_EDGES, unless
it is NULL. Return true iff any new callgraph edges were discovered as a
result of inlining. */
bool
inline_call (struct cgraph_edge *e, bool update_original,
VEC (cgraph_edge_p, heap) **new_edges,
int *overall_size)
{
int old_size = 0, new_size = 0;
struct cgraph_node *to = NULL;
struct cgraph_edge *curr = e;
struct cgraph_node *callee = cgraph_function_or_thunk_node (e->callee, NULL);
/* Don't inline inlined edges. */
gcc_assert (e->inline_failed);
/* Don't even think of inlining inline clone. */
gcc_assert (!callee->global.inlined_to);
e->inline_failed = CIF_OK;
DECL_POSSIBLY_INLINED (callee->decl) = true;
to = e->caller;
if (to->global.inlined_to)
to = to->global.inlined_to;
/* If aliases are involved, redirect edge to the actual destination and
possibly remove the aliases. */
if (e->callee != callee)
{
struct cgraph_node *alias = e->callee, *next_alias;
cgraph_redirect_edge_callee (e, callee);
while (alias && alias != callee)
{
if (!alias->callers
&& can_remove_node_now_p (alias, e))
{
next_alias = cgraph_alias_aliased_node (alias);
cgraph_remove_node (alias);
alias = next_alias;
}
else
break;
}
}
clone_inlined_nodes (e, true, update_original, overall_size);
gcc_assert (curr->callee->global.inlined_to == to);
old_size = inline_summary (to)->size;
inline_merge_summary (e);
new_size = inline_summary (to)->size;
if (overall_size)
*overall_size += new_size - old_size;
ncalls_inlined++;
/* This must happen after inline_merge_summary that rely on jump
functions of callee to not be updated. */
if (optimize)
return ipa_propagate_indirect_call_infos (curr, new_edges);
else
return false;
}
/* Copy function body of NODE and redirect all inline clones to it.
This is done before inline plan is applied to NODE when there are
still some inline clones if it.
This is neccesary because inline decisions are not really transitive
and the other inline clones may have different bodies. */
static struct cgraph_node *
save_inline_function_body (struct cgraph_node *node)
{
struct cgraph_node *first_clone, *n;
if (dump_file)
fprintf (dump_file, "\nSaving body of %s for later reuse\n",
cgraph_node_name (node));
gcc_assert (node == cgraph_get_node (node->decl));
/* first_clone will be turned into real function. */
first_clone = node->clones;
first_clone->decl = copy_node (node->decl);
cgraph_insert_node_to_hashtable (first_clone);
gcc_assert (first_clone == cgraph_get_node (first_clone->decl));
/* Now reshape the clone tree, so all other clones descends from
first_clone. */
if (first_clone->next_sibling_clone)
{
for (n = first_clone->next_sibling_clone; n->next_sibling_clone; n = n->next_sibling_clone)
n->clone_of = first_clone;
n->clone_of = first_clone;
n->next_sibling_clone = first_clone->clones;
if (first_clone->clones)
first_clone->clones->prev_sibling_clone = n;
first_clone->clones = first_clone->next_sibling_clone;
first_clone->next_sibling_clone->prev_sibling_clone = NULL;
first_clone->next_sibling_clone = NULL;
gcc_assert (!first_clone->prev_sibling_clone);
}
first_clone->clone_of = NULL;
/* Now node in question has no clones. */
node->clones = NULL;
/* Inline clones share decl with the function they are cloned
from. Walk the whole clone tree and redirect them all to the
new decl. */
if (first_clone->clones)
for (n = first_clone->clones; n != first_clone;)
{
gcc_assert (n->decl == node->decl);
n->decl = first_clone->decl;
if (n->clones)
n = n->clones;
else if (n->next_sibling_clone)
n = n->next_sibling_clone;
else
{
while (n != first_clone && !n->next_sibling_clone)
n = n->clone_of;
if (n != first_clone)
n = n->next_sibling_clone;
}
}
/* Copy the OLD_VERSION_NODE function tree to the new version. */
tree_function_versioning (node->decl, first_clone->decl, NULL, true, NULL,
NULL, NULL);
/* The function will be short lived and removed after we inline all the clones,
but make it internal so we won't confuse ourself. */
DECL_EXTERNAL (first_clone->decl) = 0;
DECL_COMDAT_GROUP (first_clone->decl) = NULL_TREE;
TREE_PUBLIC (first_clone->decl) = 0;
DECL_COMDAT (first_clone->decl) = 0;
VEC_free (ipa_opt_pass, heap,
first_clone->ipa_transforms_to_apply);
first_clone->ipa_transforms_to_apply = NULL;
#ifdef ENABLE_CHECKING
verify_cgraph_node (first_clone);
#endif
return first_clone;
}
/* Apply inline plan to function. */
unsigned int
inline_transform (struct cgraph_node *node)
{
unsigned int todo = 0;
struct cgraph_edge *e;
/* FIXME: Currently the pass manager is adding inline transform more than
once to some clones. This needs revisiting after WPA cleanups. */
if (cfun->after_inlining)
return 0;
/* We might need the body of this function so that we can expand
it inline somewhere else. */
if (cgraph_preserve_function_body_p (node))
save_inline_function_body (node);
for (e = node->callees; e; e = e->next_callee)
cgraph_redirect_edge_call_stmt_to_callee (e);
timevar_push (TV_INTEGRATION);
if (node->callees)
todo = optimize_inline_calls (current_function_decl);
timevar_pop (TV_INTEGRATION);
if (!(todo & TODO_update_ssa_any))
/* Redirecting edges might lead to a need for vops to be recomputed. */
todo |= TODO_update_ssa_only_virtuals;
cfun->always_inline_functions_inlined = true;
cfun->after_inlining = true;
return todo | execute_fixup_cfg ();
}
|