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1 /* Inlining decision heuristics.
2 Copyright (C) 2003-2019 Free Software Foundation, Inc.
3 Contributed by Jan Hubicka
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
9 Software Foundation; either version 3, or (at your option) any later
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
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 /* Inlining decision heuristics
22
23 The implementation of inliner is organized as follows:
24
25 inlining heuristics limits
26
27 can_inline_edge_p allow to check that particular inlining is allowed
28 by the limits specified by user (allowed function growth, growth and so
29 on).
30
31 Functions are inlined when it is obvious the result is profitable (such
32 as functions called once or when inlining reduce code size).
33 In addition to that we perform inlining of small functions and recursive
34 inlining.
35
36 inlining heuristics
37
38 The inliner itself is split into two passes:
39
40 pass_early_inlining
41
42 Simple local inlining pass inlining callees into current function.
43 This pass makes no use of whole unit analysis and thus it can do only
44 very simple decisions based on local properties.
45
46 The strength of the pass is that it is run in topological order
47 (reverse postorder) on the callgraph. Functions are converted into SSA
48 form just before this pass and optimized subsequently. As a result, the
49 callees of the function seen by the early inliner was already optimized
50 and results of early inlining adds a lot of optimization opportunities
51 for the local optimization.
52
53 The pass handle the obvious inlining decisions within the compilation
54 unit - inlining auto inline functions, inlining for size and
55 flattening.
56
57 main strength of the pass is the ability to eliminate abstraction
58 penalty in C++ code (via combination of inlining and early
59 optimization) and thus improve quality of analysis done by real IPA
60 optimizers.
61
62 Because of lack of whole unit knowledge, the pass cannot really make
63 good code size/performance tradeoffs. It however does very simple
64 speculative inlining allowing code size to grow by
65 EARLY_INLINING_INSNS when callee is leaf function. In this case the
66 optimizations performed later are very likely to eliminate the cost.
67
68 pass_ipa_inline
69
70 This is the real inliner able to handle inlining with whole program
71 knowledge. It performs following steps:
72
73 1) inlining of small functions. This is implemented by greedy
74 algorithm ordering all inlinable cgraph edges by their badness and
75 inlining them in this order as long as inline limits allows doing so.
76
77 This heuristics is not very good on inlining recursive calls. Recursive
78 calls can be inlined with results similar to loop unrolling. To do so,
79 special purpose recursive inliner is executed on function when
80 recursive edge is met as viable candidate.
81
82 2) Unreachable functions are removed from callgraph. Inlining leads
83 to devirtualization and other modification of callgraph so functions
84 may become unreachable during the process. Also functions declared as
85 extern inline or virtual functions are removed, since after inlining
86 we no longer need the offline bodies.
87
88 3) Functions called once and not exported from the unit are inlined.
89 This should almost always lead to reduction of code size by eliminating
90 the need for offline copy of the function. */
91
92 #include "config.h"
93 #include "system.h"
94 #include "coretypes.h"
95 #include "backend.h"
96 #include "target.h"
97 #include "rtl.h"
98 #include "tree.h"
99 #include "gimple.h"
100 #include "alloc-pool.h"
101 #include "tree-pass.h"
102 #include "gimple-ssa.h"
103 #include "cgraph.h"
104 #include "lto-streamer.h"
105 #include "trans-mem.h"
106 #include "calls.h"
107 #include "tree-inline.h"
108 #include "profile.h"
109 #include "symbol-summary.h"
110 #include "tree-vrp.h"
111 #include "ipa-prop.h"
112 #include "ipa-fnsummary.h"
113 #include "ipa-inline.h"
114 #include "ipa-utils.h"
115 #include "sreal.h"
116 #include "auto-profile.h"
117 #include "builtins.h"
118 #include "fibonacci_heap.h"
119 #include "stringpool.h"
120 #include "attribs.h"
121 #include "asan.h"
122
123 typedef fibonacci_heap <sreal, cgraph_edge> edge_heap_t;
124 typedef fibonacci_node <sreal, cgraph_edge> edge_heap_node_t;
125
126 /* Statistics we collect about inlining algorithm. */
127 static int overall_size;
128 static profile_count max_count;
129 static profile_count spec_rem;
130
131 /* Return false when inlining edge E would lead to violating
132 limits on function unit growth or stack usage growth.
133
134 The relative function body growth limit is present generally
135 to avoid problems with non-linear behavior of the compiler.
136 To allow inlining huge functions into tiny wrapper, the limit
137 is always based on the bigger of the two functions considered.
138
139 For stack growth limits we always base the growth in stack usage
140 of the callers. We want to prevent applications from segfaulting
141 on stack overflow when functions with huge stack frames gets
142 inlined. */
143
144 static bool
145 caller_growth_limits (struct cgraph_edge *e)
146 {
147 struct cgraph_node *to = e->caller;
148 struct cgraph_node *what = e->callee->ultimate_alias_target ();
149 int newsize;
150 int limit = 0;
151 HOST_WIDE_INT stack_size_limit = 0, inlined_stack;
152 ipa_size_summary *outer_info = ipa_size_summaries->get (to);
153
154 /* Look for function e->caller is inlined to. While doing
155 so work out the largest function body on the way. As
156 described above, we want to base our function growth
157 limits based on that. Not on the self size of the
158 outer function, not on the self size of inline code
159 we immediately inline to. This is the most relaxed
160 interpretation of the rule "do not grow large functions
161 too much in order to prevent compiler from exploding". */
162 while (true)
163 {
164 ipa_size_summary *size_info = ipa_size_summaries->get (to);
165 if (limit < size_info->self_size)
166 limit = size_info->self_size;
167 if (stack_size_limit < size_info->estimated_self_stack_size)
168 stack_size_limit = size_info->estimated_self_stack_size;
169 if (to->inlined_to)
170 to = to->callers->caller;
171 else
172 break;
173 }
174
175 ipa_fn_summary *what_info = ipa_fn_summaries->get (what);
176 ipa_size_summary *what_size_info = ipa_size_summaries->get (what);
177
178 if (limit < what_size_info->self_size)
179 limit = what_size_info->self_size;
180
181 limit += limit * param_large_function_growth / 100;
182
183 /* Check the size after inlining against the function limits. But allow
184 the function to shrink if it went over the limits by forced inlining. */
185 newsize = estimate_size_after_inlining (to, e);
186 if (newsize >= ipa_size_summaries->get (what)->size
187 && newsize > param_large_function_insns
188 && newsize > limit)
189 {
190 e->inline_failed = CIF_LARGE_FUNCTION_GROWTH_LIMIT;
191 return false;
192 }
193
194 if (!what_info->estimated_stack_size)
195 return true;
196
197 /* FIXME: Stack size limit often prevents inlining in Fortran programs
198 due to large i/o datastructures used by the Fortran front-end.
199 We ought to ignore this limit when we know that the edge is executed
200 on every invocation of the caller (i.e. its call statement dominates
201 exit block). We do not track this information, yet. */
202 stack_size_limit += ((gcov_type)stack_size_limit
203 * param_stack_frame_growth / 100);
204
205 inlined_stack = (ipa_get_stack_frame_offset (to)
206 + outer_info->estimated_self_stack_size
207 + what_info->estimated_stack_size);
208 /* Check new stack consumption with stack consumption at the place
209 stack is used. */
210 if (inlined_stack > stack_size_limit
211 /* If function already has large stack usage from sibling
212 inline call, we can inline, too.
213 This bit overoptimistically assume that we are good at stack
214 packing. */
215 && inlined_stack > ipa_fn_summaries->get (to)->estimated_stack_size
216 && inlined_stack > param_large_stack_frame)
217 {
218 e->inline_failed = CIF_LARGE_STACK_FRAME_GROWTH_LIMIT;
219 return false;
220 }
221 return true;
222 }
223
224 /* Dump info about why inlining has failed. */
225
226 static void
227 report_inline_failed_reason (struct cgraph_edge *e)
228 {
229 if (dump_enabled_p ())
230 {
231 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
232 " not inlinable: %C -> %C, %s\n",
233 e->caller, e->callee,
234 cgraph_inline_failed_string (e->inline_failed));
235 if ((e->inline_failed == CIF_TARGET_OPTION_MISMATCH
236 || e->inline_failed == CIF_OPTIMIZATION_MISMATCH)
237 && e->caller->lto_file_data
238 && e->callee->ultimate_alias_target ()->lto_file_data)
239 {
240 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
241 " LTO objects: %s, %s\n",
242 e->caller->lto_file_data->file_name,
243 e->callee->ultimate_alias_target ()->lto_file_data->file_name);
244 }
245 if (e->inline_failed == CIF_TARGET_OPTION_MISMATCH)
246 if (dump_file)
247 cl_target_option_print_diff
248 (dump_file, 2, target_opts_for_fn (e->caller->decl),
249 target_opts_for_fn (e->callee->ultimate_alias_target ()->decl));
250 if (e->inline_failed == CIF_OPTIMIZATION_MISMATCH)
251 if (dump_file)
252 cl_optimization_print_diff
253 (dump_file, 2, opts_for_fn (e->caller->decl),
254 opts_for_fn (e->callee->ultimate_alias_target ()->decl));
255 }
256 }
257
258 /* Decide whether sanitizer-related attributes allow inlining. */
259
260 static bool
261 sanitize_attrs_match_for_inline_p (const_tree caller, const_tree callee)
262 {
263 if (!caller || !callee)
264 return true;
265
266 /* Allow inlining always_inline functions into no_sanitize_address
267 functions. */
268 if (!sanitize_flags_p (SANITIZE_ADDRESS, caller)
269 && lookup_attribute ("always_inline", DECL_ATTRIBUTES (callee)))
270 return true;
271
272 return ((sanitize_flags_p (SANITIZE_ADDRESS, caller)
273 == sanitize_flags_p (SANITIZE_ADDRESS, callee))
274 && (sanitize_flags_p (SANITIZE_POINTER_COMPARE, caller)
275 == sanitize_flags_p (SANITIZE_POINTER_COMPARE, callee))
276 && (sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, caller)
277 == sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, callee)));
278 }
279
280 /* Used for flags where it is safe to inline when caller's value is
281 grater than callee's. */
282 #define check_maybe_up(flag) \
283 (opts_for_fn (caller->decl)->x_##flag \
284 != opts_for_fn (callee->decl)->x_##flag \
285 && (!always_inline \
286 || opts_for_fn (caller->decl)->x_##flag \
287 < opts_for_fn (callee->decl)->x_##flag))
288 /* Used for flags where it is safe to inline when caller's value is
289 smaller than callee's. */
290 #define check_maybe_down(flag) \
291 (opts_for_fn (caller->decl)->x_##flag \
292 != opts_for_fn (callee->decl)->x_##flag \
293 && (!always_inline \
294 || opts_for_fn (caller->decl)->x_##flag \
295 > opts_for_fn (callee->decl)->x_##flag))
296 /* Used for flags where exact match is needed for correctness. */
297 #define check_match(flag) \
298 (opts_for_fn (caller->decl)->x_##flag \
299 != opts_for_fn (callee->decl)->x_##flag)
300
301 /* Decide if we can inline the edge and possibly update
302 inline_failed reason.
303 We check whether inlining is possible at all and whether
304 caller growth limits allow doing so.
305
306 if REPORT is true, output reason to the dump file. */
307
308 static bool
309 can_inline_edge_p (struct cgraph_edge *e, bool report,
310 bool early = false)
311 {
312 gcc_checking_assert (e->inline_failed);
313
314 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
315 {
316 if (report)
317 report_inline_failed_reason (e);
318 return false;
319 }
320
321 bool inlinable = true;
322 enum availability avail;
323 cgraph_node *caller = (e->caller->inlined_to
324 ? e->caller->inlined_to : e->caller);
325 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
326
327 if (!callee->definition)
328 {
329 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
330 inlinable = false;
331 }
332 if (!early && (!opt_for_fn (callee->decl, optimize)
333 || !opt_for_fn (caller->decl, optimize)))
334 {
335 e->inline_failed = CIF_FUNCTION_NOT_OPTIMIZED;
336 inlinable = false;
337 }
338 else if (callee->calls_comdat_local)
339 {
340 e->inline_failed = CIF_USES_COMDAT_LOCAL;
341 inlinable = false;
342 }
343 else if (avail <= AVAIL_INTERPOSABLE)
344 {
345 e->inline_failed = CIF_OVERWRITABLE;
346 inlinable = false;
347 }
348 /* All edges with call_stmt_cannot_inline_p should have inline_failed
349 initialized to one of FINAL_ERROR reasons. */
350 else if (e->call_stmt_cannot_inline_p)
351 gcc_unreachable ();
352 /* Don't inline if the functions have different EH personalities. */
353 else if (DECL_FUNCTION_PERSONALITY (caller->decl)
354 && DECL_FUNCTION_PERSONALITY (callee->decl)
355 && (DECL_FUNCTION_PERSONALITY (caller->decl)
356 != DECL_FUNCTION_PERSONALITY (callee->decl)))
357 {
358 e->inline_failed = CIF_EH_PERSONALITY;
359 inlinable = false;
360 }
361 /* TM pure functions should not be inlined into non-TM_pure
362 functions. */
363 else if (is_tm_pure (callee->decl) && !is_tm_pure (caller->decl))
364 {
365 e->inline_failed = CIF_UNSPECIFIED;
366 inlinable = false;
367 }
368 /* Check compatibility of target optimization options. */
369 else if (!targetm.target_option.can_inline_p (caller->decl,
370 callee->decl))
371 {
372 e->inline_failed = CIF_TARGET_OPTION_MISMATCH;
373 inlinable = false;
374 }
375 else if (ipa_fn_summaries->get (callee) == NULL
376 || !ipa_fn_summaries->get (callee)->inlinable)
377 {
378 e->inline_failed = CIF_FUNCTION_NOT_INLINABLE;
379 inlinable = false;
380 }
381 /* Don't inline a function with mismatched sanitization attributes. */
382 else if (!sanitize_attrs_match_for_inline_p (caller->decl, callee->decl))
383 {
384 e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
385 inlinable = false;
386 }
387 if (!inlinable && report)
388 report_inline_failed_reason (e);
389 return inlinable;
390 }
391
392 /* Return inlining_insns_single limit for function N. If HINT is true
393 scale up the bound. */
394
395 static int
396 inline_insns_single (cgraph_node *n, bool hint)
397 {
398 if (opt_for_fn (n->decl, optimize) >= 3)
399 {
400 if (hint)
401 return param_max_inline_insns_single
402 * param_inline_heuristics_hint_percent / 100;
403 return param_max_inline_insns_single;
404 }
405 else
406 {
407 if (hint)
408 return param_max_inline_insns_single_o2
409 * param_inline_heuristics_hint_percent_o2 / 100;
410 return param_max_inline_insns_single_o2;
411 }
412 }
413
414 /* Return inlining_insns_auto limit for function N. If HINT is true
415 scale up the bound. */
416
417 static int
418 inline_insns_auto (cgraph_node *n, bool hint)
419 {
420 int max_inline_insns_auto = opt_for_fn (n->decl, param_max_inline_insns_auto);
421 if (hint)
422 return max_inline_insns_auto * param_inline_heuristics_hint_percent / 100;
423 return max_inline_insns_auto;
424 }
425
426 /* Decide if we can inline the edge and possibly update
427 inline_failed reason.
428 We check whether inlining is possible at all and whether
429 caller growth limits allow doing so.
430
431 if REPORT is true, output reason to the dump file.
432
433 if DISREGARD_LIMITS is true, ignore size limits. */
434
435 static bool
436 can_inline_edge_by_limits_p (struct cgraph_edge *e, bool report,
437 bool disregard_limits = false, bool early = false)
438 {
439 gcc_checking_assert (e->inline_failed);
440
441 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
442 {
443 if (report)
444 report_inline_failed_reason (e);
445 return false;
446 }
447
448 bool inlinable = true;
449 enum availability avail;
450 cgraph_node *caller = (e->caller->inlined_to
451 ? e->caller->inlined_to : e->caller);
452 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
453 tree caller_tree = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller->decl);
454 tree callee_tree
455 = callee ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee->decl) : NULL;
456 /* Check if caller growth allows the inlining. */
457 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
458 && !disregard_limits
459 && !lookup_attribute ("flatten",
460 DECL_ATTRIBUTES (caller->decl))
461 && !caller_growth_limits (e))
462 inlinable = false;
463 else if (callee->externally_visible
464 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl)
465 && flag_live_patching == LIVE_PATCHING_INLINE_ONLY_STATIC)
466 {
467 e->inline_failed = CIF_EXTERN_LIVE_ONLY_STATIC;
468 inlinable = false;
469 }
470 /* Don't inline a function with a higher optimization level than the
471 caller. FIXME: this is really just tip of iceberg of handling
472 optimization attribute. */
473 else if (caller_tree != callee_tree)
474 {
475 bool always_inline =
476 (DECL_DISREGARD_INLINE_LIMITS (callee->decl)
477 && lookup_attribute ("always_inline",
478 DECL_ATTRIBUTES (callee->decl)));
479 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller);
480 ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
481
482 /* Until GCC 4.9 we did not check the semantics-altering flags
483 below and inlined across optimization boundaries.
484 Enabling checks below breaks several packages by refusing
485 to inline library always_inline functions. See PR65873.
486 Disable the check for early inlining for now until better solution
487 is found. */
488 if (always_inline && early)
489 ;
490 /* There are some options that change IL semantics which means
491 we cannot inline in these cases for correctness reason.
492 Not even for always_inline declared functions. */
493 else if (check_match (flag_wrapv)
494 || check_match (flag_trapv)
495 || check_match (flag_pcc_struct_return)
496 /* When caller or callee does FP math, be sure FP codegen flags
497 compatible. */
498 || ((caller_info->fp_expressions && callee_info->fp_expressions)
499 && (check_maybe_up (flag_rounding_math)
500 || check_maybe_up (flag_trapping_math)
501 || check_maybe_down (flag_unsafe_math_optimizations)
502 || check_maybe_down (flag_finite_math_only)
503 || check_maybe_up (flag_signaling_nans)
504 || check_maybe_down (flag_cx_limited_range)
505 || check_maybe_up (flag_signed_zeros)
506 || check_maybe_down (flag_associative_math)
507 || check_maybe_down (flag_reciprocal_math)
508 || check_maybe_down (flag_fp_int_builtin_inexact)
509 /* Strictly speaking only when the callee contains function
510 calls that may end up setting errno. */
511 || check_maybe_up (flag_errno_math)))
512 /* We do not want to make code compiled with exceptions to be
513 brought into a non-EH function unless we know that the callee
514 does not throw.
515 This is tracked by DECL_FUNCTION_PERSONALITY. */
516 || (check_maybe_up (flag_non_call_exceptions)
517 && DECL_FUNCTION_PERSONALITY (callee->decl))
518 || (check_maybe_up (flag_exceptions)
519 && DECL_FUNCTION_PERSONALITY (callee->decl))
520 /* When devirtualization is diabled for callee, it is not safe
521 to inline it as we possibly mangled the type info.
522 Allow early inlining of always inlines. */
523 || (!early && check_maybe_down (flag_devirtualize)))
524 {
525 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
526 inlinable = false;
527 }
528 /* gcc.dg/pr43564.c. Apply user-forced inline even at -O0. */
529 else if (always_inline)
530 ;
531 /* When user added an attribute to the callee honor it. */
532 else if (lookup_attribute ("optimize", DECL_ATTRIBUTES (callee->decl))
533 && opts_for_fn (caller->decl) != opts_for_fn (callee->decl))
534 {
535 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
536 inlinable = false;
537 }
538 /* If explicit optimize attribute are not used, the mismatch is caused
539 by different command line options used to build different units.
540 Do not care about COMDAT functions - those are intended to be
541 optimized with the optimization flags of module they are used in.
542 Also do not care about mixing up size/speed optimization when
543 DECL_DISREGARD_INLINE_LIMITS is set. */
544 else if ((callee->merged_comdat
545 && !lookup_attribute ("optimize",
546 DECL_ATTRIBUTES (caller->decl)))
547 || DECL_DISREGARD_INLINE_LIMITS (callee->decl))
548 ;
549 /* If mismatch is caused by merging two LTO units with different
550 optimizationflags we want to be bit nicer. However never inline
551 if one of functions is not optimized at all. */
552 else if (!opt_for_fn (callee->decl, optimize)
553 || !opt_for_fn (caller->decl, optimize))
554 {
555 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
556 inlinable = false;
557 }
558 /* If callee is optimized for size and caller is not, allow inlining if
559 code shrinks or we are in param_max_inline_insns_single limit and
560 callee is inline (and thus likely an unified comdat).
561 This will allow caller to run faster. */
562 else if (opt_for_fn (callee->decl, optimize_size)
563 > opt_for_fn (caller->decl, optimize_size))
564 {
565 int growth = estimate_edge_growth (e);
566 if (growth > param_max_inline_insns_size
567 && (!DECL_DECLARED_INLINE_P (callee->decl)
568 && growth >= MAX (inline_insns_single (caller, false),
569 inline_insns_auto (caller, false))))
570 {
571 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
572 inlinable = false;
573 }
574 }
575 /* If callee is more aggressively optimized for performance than caller,
576 we generally want to inline only cheap (runtime wise) functions. */
577 else if (opt_for_fn (callee->decl, optimize_size)
578 < opt_for_fn (caller->decl, optimize_size)
579 || (opt_for_fn (callee->decl, optimize)
580 > opt_for_fn (caller->decl, optimize)))
581 {
582 if (estimate_edge_time (e)
583 >= 20 + ipa_call_summaries->get (e)->call_stmt_time)
584 {
585 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
586 inlinable = false;
587 }
588 }
589
590 }
591
592 if (!inlinable && report)
593 report_inline_failed_reason (e);
594 return inlinable;
595 }
596
597
598 /* Return true if the edge E is inlinable during early inlining. */
599
600 static bool
601 can_early_inline_edge_p (struct cgraph_edge *e)
602 {
603 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
604 /* Early inliner might get called at WPA stage when IPA pass adds new
605 function. In this case we cannot really do any of early inlining
606 because function bodies are missing. */
607 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
608 return false;
609 if (!gimple_has_body_p (callee->decl))
610 {
611 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
612 return false;
613 }
614 /* In early inliner some of callees may not be in SSA form yet
615 (i.e. the callgraph is cyclic and we did not process
616 the callee by early inliner, yet). We don't have CIF code for this
617 case; later we will re-do the decision in the real inliner. */
618 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->caller->decl))
619 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
620 {
621 if (dump_enabled_p ())
622 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
623 " edge not inlinable: not in SSA form\n");
624 return false;
625 }
626 if (!can_inline_edge_p (e, true, true)
627 || !can_inline_edge_by_limits_p (e, true, false, true))
628 return false;
629 return true;
630 }
631
632
633 /* Return number of calls in N. Ignore cheap builtins. */
634
635 static int
636 num_calls (struct cgraph_node *n)
637 {
638 struct cgraph_edge *e;
639 int num = 0;
640
641 for (e = n->callees; e; e = e->next_callee)
642 if (!is_inexpensive_builtin (e->callee->decl))
643 num++;
644 return num;
645 }
646
647
648 /* Return true if we are interested in inlining small function. */
649
650 static bool
651 want_early_inline_function_p (struct cgraph_edge *e)
652 {
653 bool want_inline = true;
654 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
655
656 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
657 ;
658 /* For AutoFDO, we need to make sure that before profile summary, all
659 hot paths' IR look exactly the same as profiled binary. As a result,
660 in einliner, we will disregard size limit and inline those callsites
661 that are:
662 * inlined in the profiled binary, and
663 * the cloned callee has enough samples to be considered "hot". */
664 else if (flag_auto_profile && afdo_callsite_hot_enough_for_early_inline (e))
665 ;
666 else if (!DECL_DECLARED_INLINE_P (callee->decl)
667 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
668 {
669 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
670 report_inline_failed_reason (e);
671 want_inline = false;
672 }
673 else
674 {
675 int growth = estimate_edge_growth (e);
676 int n;
677 int early_inlining_insns = opt_for_fn (e->caller->decl, optimize) >= 3
678 ? param_early_inlining_insns
679 : param_early_inlining_insns_o2;
680
681
682 if (growth <= param_max_inline_insns_size)
683 ;
684 else if (!e->maybe_hot_p ())
685 {
686 if (dump_enabled_p ())
687 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
688 " will not early inline: %C->%C, "
689 "call is cold and code would grow by %i\n",
690 e->caller, callee,
691 growth);
692 want_inline = false;
693 }
694 else if (growth > early_inlining_insns)
695 {
696 if (dump_enabled_p ())
697 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
698 " will not early inline: %C->%C, "
699 "growth %i exceeds --param early-inlining-insns%s\n",
700 e->caller, callee, growth,
701 opt_for_fn (e->caller->decl, optimize) >= 3
702 ? "" : "-O2");
703 want_inline = false;
704 }
705 else if ((n = num_calls (callee)) != 0
706 && growth * (n + 1) > early_inlining_insns)
707 {
708 if (dump_enabled_p ())
709 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
710 " will not early inline: %C->%C, "
711 "growth %i exceeds --param early-inlining-insns%s "
712 "divided by number of calls\n",
713 e->caller, callee, growth,
714 opt_for_fn (e->caller->decl, optimize) >= 3
715 ? "" : "-O2");
716 want_inline = false;
717 }
718 }
719 return want_inline;
720 }
721
722 /* Compute time of the edge->caller + edge->callee execution when inlining
723 does not happen. */
724
725 inline sreal
726 compute_uninlined_call_time (struct cgraph_edge *edge,
727 sreal uninlined_call_time,
728 sreal freq)
729 {
730 cgraph_node *caller = (edge->caller->inlined_to
731 ? edge->caller->inlined_to
732 : edge->caller);
733
734 if (freq > 0)
735 uninlined_call_time *= freq;
736 else
737 uninlined_call_time = uninlined_call_time >> 11;
738
739 sreal caller_time = ipa_fn_summaries->get (caller)->time;
740 return uninlined_call_time + caller_time;
741 }
742
743 /* Same as compute_uinlined_call_time but compute time when inlining
744 does happen. */
745
746 inline sreal
747 compute_inlined_call_time (struct cgraph_edge *edge,
748 sreal time,
749 sreal freq)
750 {
751 cgraph_node *caller = (edge->caller->inlined_to
752 ? edge->caller->inlined_to
753 : edge->caller);
754 sreal caller_time = ipa_fn_summaries->get (caller)->time;
755
756 if (freq > 0)
757 time *= freq;
758 else
759 time = time >> 11;
760
761 /* This calculation should match one in ipa-inline-analysis.c
762 (estimate_edge_size_and_time). */
763 time -= (sreal)ipa_call_summaries->get (edge)->call_stmt_time * freq;
764 time += caller_time;
765 if (time <= 0)
766 time = ((sreal) 1) >> 8;
767 gcc_checking_assert (time >= 0);
768 return time;
769 }
770
771 /* Return true if the speedup for inlining E is bigger than
772 PARAM_MAX_INLINE_MIN_SPEEDUP. */
773
774 static bool
775 big_speedup_p (struct cgraph_edge *e)
776 {
777 sreal unspec_time;
778 sreal spec_time = estimate_edge_time (e, &unspec_time);
779 sreal freq = e->sreal_frequency ();
780 sreal time = compute_uninlined_call_time (e, unspec_time, freq);
781 sreal inlined_time = compute_inlined_call_time (e, spec_time, freq);
782 cgraph_node *caller = (e->caller->inlined_to
783 ? e->caller->inlined_to
784 : e->caller);
785 int limit = opt_for_fn (caller->decl, optimize) >= 3
786 ? param_inline_min_speedup
787 : param_inline_min_speedup_o2;
788
789 if ((time - inlined_time) * 100 > time * limit)
790 return true;
791 return false;
792 }
793
794 /* Return true if we are interested in inlining small function.
795 When REPORT is true, report reason to dump file. */
796
797 static bool
798 want_inline_small_function_p (struct cgraph_edge *e, bool report)
799 {
800 bool want_inline = true;
801 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
802
803 /* Allow this function to be called before can_inline_edge_p,
804 since it's usually cheaper. */
805 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
806 want_inline = false;
807 else if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
808 ;
809 else if (!DECL_DECLARED_INLINE_P (callee->decl)
810 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
811 {
812 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
813 want_inline = false;
814 }
815 /* Do fast and conservative check if the function can be good
816 inline candidate. */
817 else if ((!DECL_DECLARED_INLINE_P (callee->decl)
818 && (!e->count.ipa ().initialized_p () || !e->maybe_hot_p ()))
819 && ipa_fn_summaries->get (callee)->min_size
820 - ipa_call_summaries->get (e)->call_stmt_size
821 > inline_insns_auto (e->caller, true))
822 {
823 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
824 want_inline = false;
825 }
826 else if ((DECL_DECLARED_INLINE_P (callee->decl)
827 || e->count.ipa ().nonzero_p ())
828 && ipa_fn_summaries->get (callee)->min_size
829 - ipa_call_summaries->get (e)->call_stmt_size
830 > inline_insns_single (e->caller, true))
831 {
832 if (opt_for_fn (e->caller->decl, optimize) >= 3)
833 e->inline_failed = (DECL_DECLARED_INLINE_P (callee->decl)
834 ? CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
835 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT);
836 else
837 e->inline_failed = (DECL_DECLARED_INLINE_P (callee->decl)
838 ? CIF_MAX_INLINE_INSNS_SINGLE_O2_LIMIT
839 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT);
840 want_inline = false;
841 }
842 else
843 {
844 int growth = estimate_edge_growth (e);
845 ipa_hints hints = estimate_edge_hints (e);
846 bool apply_hints = (hints & (INLINE_HINT_indirect_call
847 | INLINE_HINT_known_hot
848 | INLINE_HINT_loop_iterations
849 | INLINE_HINT_loop_stride));
850
851 if (growth <= param_max_inline_insns_size)
852 ;
853 /* Apply param_max_inline_insns_single limit. Do not do so when
854 hints suggests that inlining given function is very profitable.
855 Avoid computation of big_speedup_p when not necessary to change
856 outcome of decision. */
857 else if (DECL_DECLARED_INLINE_P (callee->decl)
858 && growth >= inline_insns_single (e->caller, apply_hints)
859 && (apply_hints
860 || growth >= inline_insns_single (e->caller, true)
861 || !big_speedup_p (e)))
862 {
863 if (opt_for_fn (e->caller->decl, optimize) >= 3)
864 e->inline_failed = CIF_MAX_INLINE_INSNS_SINGLE_LIMIT;
865 else
866 e->inline_failed = CIF_MAX_INLINE_INSNS_SINGLE_O2_LIMIT;
867 want_inline = false;
868 }
869 else if (!DECL_DECLARED_INLINE_P (callee->decl)
870 && !opt_for_fn (e->caller->decl, flag_inline_functions)
871 && growth >= param_max_inline_insns_small)
872 {
873 /* growth_positive_p is expensive, always test it last. */
874 if (growth >= inline_insns_single (e->caller, false)
875 || growth_positive_p (callee, e, growth))
876 {
877 e->inline_failed = CIF_NOT_DECLARED_INLINED;
878 want_inline = false;
879 }
880 }
881 /* Apply param_max_inline_insns_auto limit for functions not declared
882 inline. Bypass the limit when speedup seems big. */
883 else if (!DECL_DECLARED_INLINE_P (callee->decl)
884 && growth >= inline_insns_auto (e->caller, apply_hints)
885 && (apply_hints
886 || growth >= inline_insns_auto (e->caller, true)
887 || !big_speedup_p (e)))
888 {
889 /* growth_positive_p is expensive, always test it last. */
890 if (growth >= inline_insns_single (e->caller, false)
891 || growth_positive_p (callee, e, growth))
892 {
893 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
894 want_inline = false;
895 }
896 }
897 /* If call is cold, do not inline when function body would grow. */
898 else if (!e->maybe_hot_p ()
899 && (growth >= inline_insns_single (e->caller, false)
900 || growth_positive_p (callee, e, growth)))
901 {
902 e->inline_failed = CIF_UNLIKELY_CALL;
903 want_inline = false;
904 }
905 }
906 if (!want_inline && report)
907 report_inline_failed_reason (e);
908 return want_inline;
909 }
910
911 /* EDGE is self recursive edge.
912 We hand two cases - when function A is inlining into itself
913 or when function A is being inlined into another inliner copy of function
914 A within function B.
915
916 In first case OUTER_NODE points to the toplevel copy of A, while
917 in the second case OUTER_NODE points to the outermost copy of A in B.
918
919 In both cases we want to be extra selective since
920 inlining the call will just introduce new recursive calls to appear. */
921
922 static bool
923 want_inline_self_recursive_call_p (struct cgraph_edge *edge,
924 struct cgraph_node *outer_node,
925 bool peeling,
926 int depth)
927 {
928 char const *reason = NULL;
929 bool want_inline = true;
930 sreal caller_freq = 1;
931 int max_depth = param_max_inline_recursive_depth_auto;
932
933 if (DECL_DECLARED_INLINE_P (edge->caller->decl))
934 max_depth = param_max_inline_recursive_depth;
935
936 if (!edge->maybe_hot_p ())
937 {
938 reason = "recursive call is cold";
939 want_inline = false;
940 }
941 else if (depth > max_depth)
942 {
943 reason = "--param max-inline-recursive-depth exceeded.";
944 want_inline = false;
945 }
946 else if (outer_node->inlined_to
947 && (caller_freq = outer_node->callers->sreal_frequency ()) == 0)
948 {
949 reason = "caller frequency is 0";
950 want_inline = false;
951 }
952
953 if (!want_inline)
954 ;
955 /* Inlining of self recursive function into copy of itself within other
956 function is transformation similar to loop peeling.
957
958 Peeling is profitable if we can inline enough copies to make probability
959 of actual call to the self recursive function very small. Be sure that
960 the probability of recursion is small.
961
962 We ensure that the frequency of recursing is at most 1 - (1/max_depth).
963 This way the expected number of recursion is at most max_depth. */
964 else if (peeling)
965 {
966 sreal max_prob = (sreal)1 - ((sreal)1 / (sreal)max_depth);
967 int i;
968 for (i = 1; i < depth; i++)
969 max_prob = max_prob * max_prob;
970 if (edge->sreal_frequency () >= max_prob * caller_freq)
971 {
972 reason = "frequency of recursive call is too large";
973 want_inline = false;
974 }
975 }
976 /* Recursive inlining, i.e. equivalent of unrolling, is profitable if
977 recursion depth is large. We reduce function call overhead and increase
978 chances that things fit in hardware return predictor.
979
980 Recursive inlining might however increase cost of stack frame setup
981 actually slowing down functions whose recursion tree is wide rather than
982 deep.
983
984 Deciding reliably on when to do recursive inlining without profile feedback
985 is tricky. For now we disable recursive inlining when probability of self
986 recursion is low.
987
988 Recursive inlining of self recursive call within loop also results in
989 large loop depths that generally optimize badly. We may want to throttle
990 down inlining in those cases. In particular this seems to happen in one
991 of libstdc++ rb tree methods. */
992 else
993 {
994 if (edge->sreal_frequency () * 100
995 <= caller_freq
996 * param_min_inline_recursive_probability)
997 {
998 reason = "frequency of recursive call is too small";
999 want_inline = false;
1000 }
1001 }
1002 if (!want_inline && dump_enabled_p ())
1003 dump_printf_loc (MSG_MISSED_OPTIMIZATION, edge->call_stmt,
1004 " not inlining recursively: %s\n", reason);
1005 return want_inline;
1006 }
1007
1008 /* Return true when NODE has uninlinable caller;
1009 set HAS_HOT_CALL if it has hot call.
1010 Worker for cgraph_for_node_and_aliases. */
1011
1012 static bool
1013 check_callers (struct cgraph_node *node, void *has_hot_call)
1014 {
1015 struct cgraph_edge *e;
1016 for (e = node->callers; e; e = e->next_caller)
1017 {
1018 if (!opt_for_fn (e->caller->decl, flag_inline_functions_called_once)
1019 || !opt_for_fn (e->caller->decl, optimize))
1020 return true;
1021 if (!can_inline_edge_p (e, true))
1022 return true;
1023 if (e->recursive_p ())
1024 return true;
1025 if (!can_inline_edge_by_limits_p (e, true))
1026 return true;
1027 if (!(*(bool *)has_hot_call) && e->maybe_hot_p ())
1028 *(bool *)has_hot_call = true;
1029 }
1030 return false;
1031 }
1032
1033 /* If NODE has a caller, return true. */
1034
1035 static bool
1036 has_caller_p (struct cgraph_node *node, void *data ATTRIBUTE_UNUSED)
1037 {
1038 if (node->callers)
1039 return true;
1040 return false;
1041 }
1042
1043 /* Decide if inlining NODE would reduce unit size by eliminating
1044 the offline copy of function.
1045 When COLD is true the cold calls are considered, too. */
1046
1047 static bool
1048 want_inline_function_to_all_callers_p (struct cgraph_node *node, bool cold)
1049 {
1050 bool has_hot_call = false;
1051
1052 /* Aliases gets inlined along with the function they alias. */
1053 if (node->alias)
1054 return false;
1055 /* Already inlined? */
1056 if (node->inlined_to)
1057 return false;
1058 /* Does it have callers? */
1059 if (!node->call_for_symbol_and_aliases (has_caller_p, NULL, true))
1060 return false;
1061 /* Inlining into all callers would increase size? */
1062 if (growth_positive_p (node, NULL, INT_MIN) > 0)
1063 return false;
1064 /* All inlines must be possible. */
1065 if (node->call_for_symbol_and_aliases (check_callers, &has_hot_call,
1066 true))
1067 return false;
1068 if (!cold && !has_hot_call)
1069 return false;
1070 return true;
1071 }
1072
1073 /* A cost model driving the inlining heuristics in a way so the edges with
1074 smallest badness are inlined first. After each inlining is performed
1075 the costs of all caller edges of nodes affected are recomputed so the
1076 metrics may accurately depend on values such as number of inlinable callers
1077 of the function or function body size. */
1078
1079 static sreal
1080 edge_badness (struct cgraph_edge *edge, bool dump)
1081 {
1082 sreal badness;
1083 int growth;
1084 sreal edge_time, unspec_edge_time;
1085 struct cgraph_node *callee = edge->callee->ultimate_alias_target ();
1086 class ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
1087 ipa_hints hints;
1088 cgraph_node *caller = (edge->caller->inlined_to
1089 ? edge->caller->inlined_to
1090 : edge->caller);
1091
1092 growth = estimate_edge_growth (edge);
1093 edge_time = estimate_edge_time (edge, &unspec_edge_time);
1094 hints = estimate_edge_hints (edge);
1095 gcc_checking_assert (edge_time >= 0);
1096 /* Check that inlined time is better, but tolerate some roundoff issues.
1097 FIXME: When callee profile drops to 0 we account calls more. This
1098 should be fixed by never doing that. */
1099 gcc_checking_assert ((edge_time * 100
1100 - callee_info->time * 101).to_int () <= 0
1101 || callee->count.ipa ().initialized_p ());
1102 gcc_checking_assert (growth <= ipa_size_summaries->get (callee)->size);
1103
1104 if (dump)
1105 {
1106 fprintf (dump_file, " Badness calculation for %s -> %s\n",
1107 edge->caller->dump_name (),
1108 edge->callee->dump_name ());
1109 fprintf (dump_file, " size growth %i, time %f unspec %f ",
1110 growth,
1111 edge_time.to_double (),
1112 unspec_edge_time.to_double ());
1113 ipa_dump_hints (dump_file, hints);
1114 if (big_speedup_p (edge))
1115 fprintf (dump_file, " big_speedup");
1116 fprintf (dump_file, "\n");
1117 }
1118
1119 /* Always prefer inlining saving code size. */
1120 if (growth <= 0)
1121 {
1122 badness = (sreal) (-SREAL_MIN_SIG + growth) << (SREAL_MAX_EXP / 256);
1123 if (dump)
1124 fprintf (dump_file, " %f: Growth %d <= 0\n", badness.to_double (),
1125 growth);
1126 }
1127 /* Inlining into EXTERNAL functions is not going to change anything unless
1128 they are themselves inlined. */
1129 else if (DECL_EXTERNAL (caller->decl))
1130 {
1131 if (dump)
1132 fprintf (dump_file, " max: function is external\n");
1133 return sreal::max ();
1134 }
1135 /* When profile is available. Compute badness as:
1136
1137 time_saved * caller_count
1138 goodness = -------------------------------------------------
1139 growth_of_caller * overall_growth * combined_size
1140
1141 badness = - goodness
1142
1143 Again use negative value to make calls with profile appear hotter
1144 then calls without.
1145 */
1146 else if (opt_for_fn (caller->decl, flag_guess_branch_prob)
1147 || caller->count.ipa ().nonzero_p ())
1148 {
1149 sreal numerator, denominator;
1150 int overall_growth;
1151 sreal freq = edge->sreal_frequency ();
1152 sreal inlined_time = compute_inlined_call_time (edge, edge_time, freq);
1153
1154 numerator = (compute_uninlined_call_time (edge, unspec_edge_time, freq)
1155 - inlined_time);
1156 if (numerator <= 0)
1157 numerator = ((sreal) 1 >> 8);
1158 if (caller->count.ipa ().nonzero_p ())
1159 numerator *= caller->count.ipa ().to_gcov_type ();
1160 else if (caller->count.ipa ().initialized_p ())
1161 numerator = numerator >> 11;
1162 denominator = growth;
1163
1164 overall_growth = callee_info->growth;
1165
1166 #if 1
1167 /* Look for inliner wrappers of the form:
1168
1169 inline_caller ()
1170 {
1171 do_fast_job...
1172 if (need_more_work)
1173 noninline_callee ();
1174 }
1175 Withhout penalizing this case, we usually inline noninline_callee
1176 into the inline_caller because overall_growth is small preventing
1177 further inlining of inline_caller.
1178
1179 Penalize only callgraph edges to functions with small overall
1180 growth ...
1181 */
1182 if (growth > overall_growth
1183 /* ... and having only one caller which is not inlined ... */
1184 && callee_info->single_caller
1185 && !edge->caller->inlined_to
1186 /* ... and edges executed only conditionally ... */
1187 && freq < 1
1188 /* ... consider case where callee is not inline but caller is ... */
1189 && ((!DECL_DECLARED_INLINE_P (edge->callee->decl)
1190 && DECL_DECLARED_INLINE_P (caller->decl))
1191 /* ... or when early optimizers decided to split and edge
1192 frequency still indicates splitting is a win ... */
1193 || (callee->split_part && !caller->split_part
1194 && freq * 100 < param_partial_inlining_entry_probability
1195 /* ... and do not overwrite user specified hints. */
1196 && (!DECL_DECLARED_INLINE_P (edge->callee->decl)
1197 || DECL_DECLARED_INLINE_P (caller->decl)))))
1198 {
1199 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller);
1200 int caller_growth = caller_info->growth;
1201
1202 /* Only apply the penalty when caller looks like inline candidate,
1203 and it is not called once. */
1204 if (!caller_info->single_caller && overall_growth < caller_growth
1205 && caller_info->inlinable
1206 && ipa_size_summaries->get (caller)->size
1207 < (DECL_DECLARED_INLINE_P (caller->decl)
1208 ? inline_insns_single (caller, false)
1209 : inline_insns_auto (caller, false)))
1210 {
1211 if (dump)
1212 fprintf (dump_file,
1213 " Wrapper penalty. Increasing growth %i to %i\n",
1214 overall_growth, caller_growth);
1215 overall_growth = caller_growth;
1216 }
1217 }
1218 #endif
1219 if (overall_growth > 0)
1220 {
1221 /* Strongly preffer functions with few callers that can be inlined
1222 fully. The square root here leads to smaller binaries at average.
1223 Watch however for extreme cases and return to linear function
1224 when growth is large. */
1225 if (overall_growth < 256)
1226 overall_growth *= overall_growth;
1227 else
1228 overall_growth += 256 * 256 - 256;
1229 denominator *= overall_growth;
1230 }
1231 denominator *= ipa_size_summaries->get (caller)->size + growth;
1232
1233 badness = - numerator / denominator;
1234
1235 if (dump)
1236 {
1237 fprintf (dump_file,
1238 " %f: guessed profile. frequency %f, count %" PRId64
1239 " caller count %" PRId64
1240 " time w/o inlining %f, time with inlining %f"
1241 " overall growth %i (current) %i (original)"
1242 " %i (compensated)\n",
1243 badness.to_double (),
1244 freq.to_double (),
1245 edge->count.ipa ().initialized_p () ? edge->count.ipa ().to_gcov_type () : -1,
1246 caller->count.ipa ().initialized_p () ? caller->count.ipa ().to_gcov_type () : -1,
1247 compute_uninlined_call_time (edge,
1248 unspec_edge_time, freq).to_double (),
1249 inlined_time.to_double (),
1250 estimate_growth (callee),
1251 callee_info->growth, overall_growth);
1252 }
1253 }
1254 /* When function local profile is not available or it does not give
1255 useful information (ie frequency is zero), base the cost on
1256 loop nest and overall size growth, so we optimize for overall number
1257 of functions fully inlined in program. */
1258 else
1259 {
1260 int nest = MIN (ipa_call_summaries->get (edge)->loop_depth, 8);
1261 badness = growth;
1262
1263 /* Decrease badness if call is nested. */
1264 if (badness > 0)
1265 badness = badness >> nest;
1266 else
1267 badness = badness << nest;
1268 if (dump)
1269 fprintf (dump_file, " %f: no profile. nest %i\n",
1270 badness.to_double (), nest);
1271 }
1272 gcc_checking_assert (badness != 0);
1273
1274 if (edge->recursive_p ())
1275 badness = badness.shift (badness > 0 ? 4 : -4);
1276 if ((hints & (INLINE_HINT_indirect_call
1277 | INLINE_HINT_loop_iterations
1278 | INLINE_HINT_loop_stride))
1279 || callee_info->growth <= 0)
1280 badness = badness.shift (badness > 0 ? -2 : 2);
1281 if (hints & (INLINE_HINT_same_scc))
1282 badness = badness.shift (badness > 0 ? 3 : -3);
1283 else if (hints & (INLINE_HINT_in_scc))
1284 badness = badness.shift (badness > 0 ? 2 : -2);
1285 else if (hints & (INLINE_HINT_cross_module))
1286 badness = badness.shift (badness > 0 ? 1 : -1);
1287 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
1288 badness = badness.shift (badness > 0 ? -4 : 4);
1289 else if ((hints & INLINE_HINT_declared_inline))
1290 badness = badness.shift (badness > 0 ? -3 : 3);
1291 if (dump)
1292 fprintf (dump_file, " Adjusted by hints %f\n", badness.to_double ());
1293 return badness;
1294 }
1295
1296 /* Recompute badness of EDGE and update its key in HEAP if needed. */
1297 static inline void
1298 update_edge_key (edge_heap_t *heap, struct cgraph_edge *edge)
1299 {
1300 sreal badness = edge_badness (edge, false);
1301 if (edge->aux)
1302 {
1303 edge_heap_node_t *n = (edge_heap_node_t *) edge->aux;
1304 gcc_checking_assert (n->get_data () == edge);
1305
1306 /* fibonacci_heap::replace_key does busy updating of the
1307 heap that is unnecesarily expensive.
1308 We do lazy increases: after extracting minimum if the key
1309 turns out to be out of date, it is re-inserted into heap
1310 with correct value. */
1311 if (badness < n->get_key ())
1312 {
1313 if (dump_file && (dump_flags & TDF_DETAILS))
1314 {
1315 fprintf (dump_file,
1316 " decreasing badness %s -> %s, %f to %f\n",
1317 edge->caller->dump_name (),
1318 edge->callee->dump_name (),
1319 n->get_key ().to_double (),
1320 badness.to_double ());
1321 }
1322 heap->decrease_key (n, badness);
1323 }
1324 }
1325 else
1326 {
1327 if (dump_file && (dump_flags & TDF_DETAILS))
1328 {
1329 fprintf (dump_file,
1330 " enqueuing call %s -> %s, badness %f\n",
1331 edge->caller->dump_name (),
1332 edge->callee->dump_name (),
1333 badness.to_double ());
1334 }
1335 edge->aux = heap->insert (badness, edge);
1336 }
1337 }
1338
1339
1340 /* NODE was inlined.
1341 All caller edges needs to be resetted because
1342 size estimates change. Similarly callees needs reset
1343 because better context may be known. */
1344
1345 static void
1346 reset_edge_caches (struct cgraph_node *node)
1347 {
1348 struct cgraph_edge *edge;
1349 struct cgraph_edge *e = node->callees;
1350 struct cgraph_node *where = node;
1351 struct ipa_ref *ref;
1352
1353 if (where->inlined_to)
1354 where = where->inlined_to;
1355
1356 reset_node_cache (where);
1357
1358 if (edge_growth_cache != NULL)
1359 for (edge = where->callers; edge; edge = edge->next_caller)
1360 if (edge->inline_failed)
1361 edge_growth_cache->remove (edge);
1362
1363 FOR_EACH_ALIAS (where, ref)
1364 reset_edge_caches (dyn_cast <cgraph_node *> (ref->referring));
1365
1366 if (!e)
1367 return;
1368
1369 while (true)
1370 if (!e->inline_failed && e->callee->callees)
1371 e = e->callee->callees;
1372 else
1373 {
1374 if (edge_growth_cache != NULL && e->inline_failed)
1375 edge_growth_cache->remove (e);
1376 if (e->next_callee)
1377 e = e->next_callee;
1378 else
1379 {
1380 do
1381 {
1382 if (e->caller == node)
1383 return;
1384 e = e->caller->callers;
1385 }
1386 while (!e->next_callee);
1387 e = e->next_callee;
1388 }
1389 }
1390 }
1391
1392 /* Recompute HEAP nodes for each of caller of NODE.
1393 UPDATED_NODES track nodes we already visited, to avoid redundant work.
1394 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that
1395 it is inlinable. Otherwise check all edges. */
1396
1397 static void
1398 update_caller_keys (edge_heap_t *heap, struct cgraph_node *node,
1399 bitmap updated_nodes,
1400 struct cgraph_edge *check_inlinablity_for)
1401 {
1402 struct cgraph_edge *edge;
1403 struct ipa_ref *ref;
1404
1405 if ((!node->alias && !ipa_fn_summaries->get (node)->inlinable)
1406 || node->inlined_to)
1407 return;
1408 if (!bitmap_set_bit (updated_nodes, node->get_uid ()))
1409 return;
1410
1411 FOR_EACH_ALIAS (node, ref)
1412 {
1413 struct cgraph_node *alias = dyn_cast <cgraph_node *> (ref->referring);
1414 update_caller_keys (heap, alias, updated_nodes, check_inlinablity_for);
1415 }
1416
1417 for (edge = node->callers; edge; edge = edge->next_caller)
1418 if (edge->inline_failed)
1419 {
1420 if (!check_inlinablity_for
1421 || check_inlinablity_for == edge)
1422 {
1423 if (can_inline_edge_p (edge, false)
1424 && want_inline_small_function_p (edge, false)
1425 && can_inline_edge_by_limits_p (edge, false))
1426 update_edge_key (heap, edge);
1427 else if (edge->aux)
1428 {
1429 report_inline_failed_reason (edge);
1430 heap->delete_node ((edge_heap_node_t *) edge->aux);
1431 edge->aux = NULL;
1432 }
1433 }
1434 else if (edge->aux)
1435 update_edge_key (heap, edge);
1436 }
1437 }
1438
1439 /* Recompute HEAP nodes for each uninlined call in NODE.
1440 This is used when we know that edge badnesses are going only to increase
1441 (we introduced new call site) and thus all we need is to insert newly
1442 created edges into heap. */
1443
1444 static void
1445 update_callee_keys (edge_heap_t *heap, struct cgraph_node *node,
1446 bitmap updated_nodes)
1447 {
1448 struct cgraph_edge *e = node->callees;
1449
1450 if (!e)
1451 return;
1452 while (true)
1453 if (!e->inline_failed && e->callee->callees)
1454 e = e->callee->callees;
1455 else
1456 {
1457 enum availability avail;
1458 struct cgraph_node *callee;
1459 /* We do not reset callee growth cache here. Since we added a new call,
1460 growth chould have just increased and consequentely badness metric
1461 don't need updating. */
1462 if (e->inline_failed
1463 && (callee = e->callee->ultimate_alias_target (&avail, e->caller))
1464 && ipa_fn_summaries->get (callee) != NULL
1465 && ipa_fn_summaries->get (callee)->inlinable
1466 && avail >= AVAIL_AVAILABLE
1467 && !bitmap_bit_p (updated_nodes, callee->get_uid ()))
1468 {
1469 if (can_inline_edge_p (e, false)
1470 && want_inline_small_function_p (e, false)
1471 && can_inline_edge_by_limits_p (e, false))
1472 update_edge_key (heap, e);
1473 else if (e->aux)
1474 {
1475 report_inline_failed_reason (e);
1476 heap->delete_node ((edge_heap_node_t *) e->aux);
1477 e->aux = NULL;
1478 }
1479 }
1480 if (e->next_callee)
1481 e = e->next_callee;
1482 else
1483 {
1484 do
1485 {
1486 if (e->caller == node)
1487 return;
1488 e = e->caller->callers;
1489 }
1490 while (!e->next_callee);
1491 e = e->next_callee;
1492 }
1493 }
1494 }
1495
1496 /* Enqueue all recursive calls from NODE into priority queue depending on
1497 how likely we want to recursively inline the call. */
1498
1499 static void
1500 lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where,
1501 edge_heap_t *heap)
1502 {
1503 struct cgraph_edge *e;
1504 enum availability avail;
1505
1506 for (e = where->callees; e; e = e->next_callee)
1507 if (e->callee == node
1508 || (e->callee->ultimate_alias_target (&avail, e->caller) == node
1509 && avail > AVAIL_INTERPOSABLE))
1510 heap->insert (-e->sreal_frequency (), e);
1511 for (e = where->callees; e; e = e->next_callee)
1512 if (!e->inline_failed)
1513 lookup_recursive_calls (node, e->callee, heap);
1514 }
1515
1516 /* Decide on recursive inlining: in the case function has recursive calls,
1517 inline until body size reaches given argument. If any new indirect edges
1518 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
1519 is NULL. */
1520
1521 static bool
1522 recursive_inlining (struct cgraph_edge *edge,
1523 vec<cgraph_edge *> *new_edges)
1524 {
1525 int limit = param_max_inline_insns_recursive_auto;
1526 edge_heap_t heap (sreal::min ());
1527 struct cgraph_node *node;
1528 struct cgraph_edge *e;
1529 struct cgraph_node *master_clone = NULL, *next;
1530 int depth = 0;
1531 int n = 0;
1532
1533 node = edge->caller;
1534 if (node->inlined_to)
1535 node = node->inlined_to;
1536
1537 if (DECL_DECLARED_INLINE_P (node->decl))
1538 limit = param_max_inline_insns_recursive;
1539
1540 /* Make sure that function is small enough to be considered for inlining. */
1541 if (estimate_size_after_inlining (node, edge) >= limit)
1542 return false;
1543 lookup_recursive_calls (node, node, &heap);
1544 if (heap.empty ())
1545 return false;
1546
1547 if (dump_file)
1548 fprintf (dump_file,
1549 " Performing recursive inlining on %s\n",
1550 node->name ());
1551
1552 /* Do the inlining and update list of recursive call during process. */
1553 while (!heap.empty ())
1554 {
1555 struct cgraph_edge *curr = heap.extract_min ();
1556 struct cgraph_node *cnode, *dest = curr->callee;
1557
1558 if (!can_inline_edge_p (curr, true)
1559 || !can_inline_edge_by_limits_p (curr, true))
1560 continue;
1561
1562 /* MASTER_CLONE is produced in the case we already started modified
1563 the function. Be sure to redirect edge to the original body before
1564 estimating growths otherwise we will be seeing growths after inlining
1565 the already modified body. */
1566 if (master_clone)
1567 {
1568 curr->redirect_callee (master_clone);
1569 if (edge_growth_cache != NULL)
1570 edge_growth_cache->remove (curr);
1571 }
1572
1573 if (estimate_size_after_inlining (node, curr) > limit)
1574 {
1575 curr->redirect_callee (dest);
1576 if (edge_growth_cache != NULL)
1577 edge_growth_cache->remove (curr);
1578 break;
1579 }
1580
1581 depth = 1;
1582 for (cnode = curr->caller;
1583 cnode->inlined_to; cnode = cnode->callers->caller)
1584 if (node->decl
1585 == curr->callee->ultimate_alias_target ()->decl)
1586 depth++;
1587
1588 if (!want_inline_self_recursive_call_p (curr, node, false, depth))
1589 {
1590 curr->redirect_callee (dest);
1591 if (edge_growth_cache != NULL)
1592 edge_growth_cache->remove (curr);
1593 continue;
1594 }
1595
1596 if (dump_file)
1597 {
1598 fprintf (dump_file,
1599 " Inlining call of depth %i", depth);
1600 if (node->count.nonzero_p () && curr->count.initialized_p ())
1601 {
1602 fprintf (dump_file, " called approx. %.2f times per call",
1603 (double)curr->count.to_gcov_type ()
1604 / node->count.to_gcov_type ());
1605 }
1606 fprintf (dump_file, "\n");
1607 }
1608 if (!master_clone)
1609 {
1610 /* We need original clone to copy around. */
1611 master_clone = node->create_clone (node->decl, node->count,
1612 false, vNULL, true, NULL, NULL);
1613 for (e = master_clone->callees; e; e = e->next_callee)
1614 if (!e->inline_failed)
1615 clone_inlined_nodes (e, true, false, NULL);
1616 curr->redirect_callee (master_clone);
1617 if (edge_growth_cache != NULL)
1618 edge_growth_cache->remove (curr);
1619 }
1620
1621 inline_call (curr, false, new_edges, &overall_size, true);
1622 reset_node_cache (node);
1623 lookup_recursive_calls (node, curr->callee, &heap);
1624 n++;
1625 }
1626
1627 if (!heap.empty () && dump_file)
1628 fprintf (dump_file, " Recursive inlining growth limit met.\n");
1629
1630 if (!master_clone)
1631 return false;
1632
1633 if (dump_enabled_p ())
1634 dump_printf_loc (MSG_NOTE, edge->call_stmt,
1635 "\n Inlined %i times, "
1636 "body grown from size %i to %i, time %f to %f\n", n,
1637 ipa_size_summaries->get (master_clone)->size,
1638 ipa_size_summaries->get (node)->size,
1639 ipa_fn_summaries->get (master_clone)->time.to_double (),
1640 ipa_fn_summaries->get (node)->time.to_double ());
1641
1642 /* Remove master clone we used for inlining. We rely that clones inlined
1643 into master clone gets queued just before master clone so we don't
1644 need recursion. */
1645 for (node = symtab->first_function (); node != master_clone;
1646 node = next)
1647 {
1648 next = symtab->next_function (node);
1649 if (node->inlined_to == master_clone)
1650 node->remove ();
1651 }
1652 master_clone->remove ();
1653 return true;
1654 }
1655
1656
1657 /* Given whole compilation unit estimate of INSNS, compute how large we can
1658 allow the unit to grow. */
1659
1660 static int
1661 compute_max_insns (int insns)
1662 {
1663 int max_insns = insns;
1664 if (max_insns < param_large_unit_insns)
1665 max_insns = param_large_unit_insns;
1666
1667 return ((int64_t) max_insns
1668 * (100 + param_inline_unit_growth) / 100);
1669 }
1670
1671
1672 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1673
1674 static void
1675 add_new_edges_to_heap (edge_heap_t *heap, vec<cgraph_edge *> new_edges)
1676 {
1677 while (new_edges.length () > 0)
1678 {
1679 struct cgraph_edge *edge = new_edges.pop ();
1680
1681 gcc_assert (!edge->aux);
1682 gcc_assert (edge->callee);
1683 if (edge->inline_failed
1684 && can_inline_edge_p (edge, true)
1685 && want_inline_small_function_p (edge, true)
1686 && can_inline_edge_by_limits_p (edge, true))
1687 edge->aux = heap->insert (edge_badness (edge, false), edge);
1688 }
1689 }
1690
1691 /* Remove EDGE from the fibheap. */
1692
1693 static void
1694 heap_edge_removal_hook (struct cgraph_edge *e, void *data)
1695 {
1696 if (e->aux)
1697 {
1698 ((edge_heap_t *)data)->delete_node ((edge_heap_node_t *)e->aux);
1699 e->aux = NULL;
1700 }
1701 }
1702
1703 /* Return true if speculation of edge E seems useful.
1704 If ANTICIPATE_INLINING is true, be conservative and hope that E
1705 may get inlined. */
1706
1707 bool
1708 speculation_useful_p (struct cgraph_edge *e, bool anticipate_inlining)
1709 {
1710 /* If we have already decided to inline the edge, it seems useful. */
1711 if (!e->inline_failed)
1712 return true;
1713
1714 enum availability avail;
1715 struct cgraph_node *target = e->callee->ultimate_alias_target (&avail,
1716 e->caller);
1717 struct cgraph_edge *direct, *indirect;
1718 struct ipa_ref *ref;
1719
1720 gcc_assert (e->speculative && !e->indirect_unknown_callee);
1721
1722 if (!e->maybe_hot_p ())
1723 return false;
1724
1725 /* See if IP optimizations found something potentially useful about the
1726 function. For now we look only for CONST/PURE flags. Almost everything
1727 else we propagate is useless. */
1728 if (avail >= AVAIL_AVAILABLE)
1729 {
1730 int ecf_flags = flags_from_decl_or_type (target->decl);
1731 if (ecf_flags & ECF_CONST)
1732 {
1733 e->speculative_call_info (direct, indirect, ref);
1734 if (!(indirect->indirect_info->ecf_flags & ECF_CONST))
1735 return true;
1736 }
1737 else if (ecf_flags & ECF_PURE)
1738 {
1739 e->speculative_call_info (direct, indirect, ref);
1740 if (!(indirect->indirect_info->ecf_flags & ECF_PURE))
1741 return true;
1742 }
1743 }
1744 /* If we did not managed to inline the function nor redirect
1745 to an ipa-cp clone (that are seen by having local flag set),
1746 it is probably pointless to inline it unless hardware is missing
1747 indirect call predictor. */
1748 if (!anticipate_inlining && !target->local)
1749 return false;
1750 /* For overwritable targets there is not much to do. */
1751 if (!can_inline_edge_p (e, false)
1752 || !can_inline_edge_by_limits_p (e, false, true))
1753 return false;
1754 /* OK, speculation seems interesting. */
1755 return true;
1756 }
1757
1758 /* We know that EDGE is not going to be inlined.
1759 See if we can remove speculation. */
1760
1761 static void
1762 resolve_noninline_speculation (edge_heap_t *edge_heap, struct cgraph_edge *edge)
1763 {
1764 if (edge->speculative && !speculation_useful_p (edge, false))
1765 {
1766 struct cgraph_node *node = edge->caller;
1767 struct cgraph_node *where = node->inlined_to
1768 ? node->inlined_to : node;
1769 auto_bitmap updated_nodes;
1770
1771 if (edge->count.ipa ().initialized_p ())
1772 spec_rem += edge->count.ipa ();
1773 edge->resolve_speculation ();
1774 reset_edge_caches (where);
1775 ipa_update_overall_fn_summary (where);
1776 update_caller_keys (edge_heap, where,
1777 updated_nodes, NULL);
1778 update_callee_keys (edge_heap, where,
1779 updated_nodes);
1780 }
1781 }
1782
1783 /* Return true if NODE should be accounted for overall size estimate.
1784 Skip all nodes optimized for size so we can measure the growth of hot
1785 part of program no matter of the padding. */
1786
1787 bool
1788 inline_account_function_p (struct cgraph_node *node)
1789 {
1790 return (!DECL_EXTERNAL (node->decl)
1791 && !opt_for_fn (node->decl, optimize_size)
1792 && node->frequency != NODE_FREQUENCY_UNLIKELY_EXECUTED);
1793 }
1794
1795 /* Count number of callers of NODE and store it into DATA (that
1796 points to int. Worker for cgraph_for_node_and_aliases. */
1797
1798 static bool
1799 sum_callers (struct cgraph_node *node, void *data)
1800 {
1801 struct cgraph_edge *e;
1802 int *num_calls = (int *)data;
1803
1804 for (e = node->callers; e; e = e->next_caller)
1805 (*num_calls)++;
1806 return false;
1807 }
1808
1809 /* We only propagate across edges with non-interposable callee. */
1810
1811 inline bool
1812 ignore_edge_p (struct cgraph_edge *e)
1813 {
1814 enum availability avail;
1815 e->callee->function_or_virtual_thunk_symbol (&avail, e->caller);
1816 return (avail <= AVAIL_INTERPOSABLE);
1817 }
1818
1819 /* We use greedy algorithm for inlining of small functions:
1820 All inline candidates are put into prioritized heap ordered in
1821 increasing badness.
1822
1823 The inlining of small functions is bounded by unit growth parameters. */
1824
1825 static void
1826 inline_small_functions (void)
1827 {
1828 struct cgraph_node *node;
1829 struct cgraph_edge *edge;
1830 edge_heap_t edge_heap (sreal::min ());
1831 auto_bitmap updated_nodes;
1832 int min_size, max_size;
1833 auto_vec<cgraph_edge *> new_indirect_edges;
1834 int initial_size = 0;
1835 struct cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count);
1836 struct cgraph_edge_hook_list *edge_removal_hook_holder;
1837 new_indirect_edges.create (8);
1838
1839 edge_removal_hook_holder
1840 = symtab->add_edge_removal_hook (&heap_edge_removal_hook, &edge_heap);
1841
1842 /* Compute overall unit size and other global parameters used by badness
1843 metrics. */
1844
1845 max_count = profile_count::uninitialized ();
1846 ipa_reduced_postorder (order, true, ignore_edge_p);
1847 free (order);
1848
1849 FOR_EACH_DEFINED_FUNCTION (node)
1850 if (!node->inlined_to)
1851 {
1852 if (!node->alias && node->analyzed
1853 && (node->has_gimple_body_p () || node->thunk.thunk_p)
1854 && opt_for_fn (node->decl, optimize))
1855 {
1856 class ipa_fn_summary *info = ipa_fn_summaries->get (node);
1857 struct ipa_dfs_info *dfs = (struct ipa_dfs_info *) node->aux;
1858
1859 /* Do not account external functions, they will be optimized out
1860 if not inlined. Also only count the non-cold portion of program. */
1861 if (inline_account_function_p (node))
1862 initial_size += ipa_size_summaries->get (node)->size;
1863 info->growth = estimate_growth (node);
1864
1865 int num_calls = 0;
1866 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
1867 true);
1868 if (num_calls == 1)
1869 info->single_caller = true;
1870 if (dfs && dfs->next_cycle)
1871 {
1872 struct cgraph_node *n2;
1873 int id = dfs->scc_no + 1;
1874 for (n2 = node; n2;
1875 n2 = ((struct ipa_dfs_info *) n2->aux)->next_cycle)
1876 if (opt_for_fn (n2->decl, optimize))
1877 {
1878 ipa_fn_summary *info2 = ipa_fn_summaries->get
1879 (n2->inlined_to ? n2->inlined_to : n2);
1880 if (info2->scc_no)
1881 break;
1882 info2->scc_no = id;
1883 }
1884 }
1885 }
1886
1887 for (edge = node->callers; edge; edge = edge->next_caller)
1888 max_count = max_count.max (edge->count.ipa ());
1889 }
1890 ipa_free_postorder_info ();
1891 initialize_growth_caches ();
1892
1893 if (dump_file)
1894 fprintf (dump_file,
1895 "\nDeciding on inlining of small functions. Starting with size %i.\n",
1896 initial_size);
1897
1898 overall_size = initial_size;
1899 max_size = compute_max_insns (overall_size);
1900 min_size = overall_size;
1901
1902 /* Populate the heap with all edges we might inline. */
1903
1904 FOR_EACH_DEFINED_FUNCTION (node)
1905 {
1906 bool update = false;
1907 struct cgraph_edge *next = NULL;
1908 bool has_speculative = false;
1909
1910 if (!opt_for_fn (node->decl, optimize))
1911 continue;
1912
1913 if (dump_file)
1914 fprintf (dump_file, "Enqueueing calls in %s.\n", node->dump_name ());
1915
1916 for (edge = node->callees; edge; edge = next)
1917 {
1918 next = edge->next_callee;
1919 if (edge->inline_failed
1920 && !edge->aux
1921 && can_inline_edge_p (edge, true)
1922 && want_inline_small_function_p (edge, true)
1923 && can_inline_edge_by_limits_p (edge, true)
1924 && edge->inline_failed)
1925 {
1926 gcc_assert (!edge->aux);
1927 update_edge_key (&edge_heap, edge);
1928 }
1929 if (edge->speculative)
1930 has_speculative = true;
1931 }
1932 if (has_speculative)
1933 for (edge = node->callees; edge; edge = next)
1934 {
1935 next = edge->next_callee;
1936 if (edge->speculative
1937 && !speculation_useful_p (edge, edge->aux != NULL))
1938 {
1939 edge->resolve_speculation ();
1940 update = true;
1941 }
1942 }
1943 if (update)
1944 {
1945 struct cgraph_node *where = node->inlined_to
1946 ? node->inlined_to : node;
1947 ipa_update_overall_fn_summary (where);
1948 reset_edge_caches (where);
1949 update_caller_keys (&edge_heap, where,
1950 updated_nodes, NULL);
1951 update_callee_keys (&edge_heap, where,
1952 updated_nodes);
1953 bitmap_clear (updated_nodes);
1954 }
1955 }
1956
1957 gcc_assert (in_lto_p
1958 || !(max_count > 0)
1959 || (profile_info && flag_branch_probabilities));
1960
1961 while (!edge_heap.empty ())
1962 {
1963 int old_size = overall_size;
1964 struct cgraph_node *where, *callee;
1965 sreal badness = edge_heap.min_key ();
1966 sreal current_badness;
1967 int growth;
1968
1969 edge = edge_heap.extract_min ();
1970 gcc_assert (edge->aux);
1971 edge->aux = NULL;
1972 if (!edge->inline_failed || !edge->callee->analyzed)
1973 continue;
1974
1975 /* Be sure that caches are maintained consistent.
1976 This check is affected by scaling roundoff errors when compiling for
1977 IPA this we skip it in that case. */
1978 if (flag_checking && !edge->callee->count.ipa_p ()
1979 && (!max_count.initialized_p () || !max_count.nonzero_p ()))
1980 {
1981 sreal cached_badness = edge_badness (edge, false);
1982
1983 int old_size_est = estimate_edge_size (edge);
1984 sreal old_time_est = estimate_edge_time (edge);
1985 int old_hints_est = estimate_edge_hints (edge);
1986
1987 if (edge_growth_cache != NULL)
1988 edge_growth_cache->remove (edge);
1989 reset_node_cache (edge->caller->inlined_to
1990 ? edge->caller->inlined_to
1991 : edge->caller);
1992 gcc_assert (old_size_est == estimate_edge_size (edge));
1993 gcc_assert (old_time_est == estimate_edge_time (edge));
1994 /* FIXME:
1995
1996 gcc_assert (old_hints_est == estimate_edge_hints (edge));
1997
1998 fails with profile feedback because some hints depends on
1999 maybe_hot_edge_p predicate and because callee gets inlined to other
2000 calls, the edge may become cold.
2001 This ought to be fixed by computing relative probabilities
2002 for given invocation but that will be better done once whole
2003 code is converted to sreals. Disable for now and revert to "wrong"
2004 value so enable/disable checking paths agree. */
2005 edge_growth_cache->get (edge)->hints = old_hints_est + 1;
2006
2007 /* When updating the edge costs, we only decrease badness in the keys.
2008 Increases of badness are handled lazilly; when we see key with out
2009 of date value on it, we re-insert it now. */
2010 current_badness = edge_badness (edge, false);
2011 gcc_assert (cached_badness == current_badness);
2012 gcc_assert (current_badness >= badness);
2013 }
2014 else
2015 current_badness = edge_badness (edge, false);
2016 if (current_badness != badness)
2017 {
2018 if (edge_heap.min () && current_badness > edge_heap.min_key ())
2019 {
2020 edge->aux = edge_heap.insert (current_badness, edge);
2021 continue;
2022 }
2023 else
2024 badness = current_badness;
2025 }
2026
2027 if (!can_inline_edge_p (edge, true)
2028 || !can_inline_edge_by_limits_p (edge, true))
2029 {
2030 resolve_noninline_speculation (&edge_heap, edge);
2031 continue;
2032 }
2033
2034 callee = edge->callee->ultimate_alias_target ();
2035 growth = estimate_edge_growth (edge);
2036 if (dump_file)
2037 {
2038 fprintf (dump_file,
2039 "\nConsidering %s with %i size\n",
2040 callee->dump_name (),
2041 ipa_size_summaries->get (callee)->size);
2042 fprintf (dump_file,
2043 " to be inlined into %s in %s:%i\n"
2044 " Estimated badness is %f, frequency %.2f.\n",
2045 edge->caller->dump_name (),
2046 edge->call_stmt
2047 && (LOCATION_LOCUS (gimple_location ((const gimple *)
2048 edge->call_stmt))
2049 > BUILTINS_LOCATION)
2050 ? gimple_filename ((const gimple *) edge->call_stmt)
2051 : "unknown",
2052 edge->call_stmt
2053 ? gimple_lineno ((const gimple *) edge->call_stmt)
2054 : -1,
2055 badness.to_double (),
2056 edge->sreal_frequency ().to_double ());
2057 if (edge->count.ipa ().initialized_p ())
2058 {
2059 fprintf (dump_file, " Called ");
2060 edge->count.ipa ().dump (dump_file);
2061 fprintf (dump_file, " times\n");
2062 }
2063 if (dump_flags & TDF_DETAILS)
2064 edge_badness (edge, true);
2065 }
2066
2067 if (overall_size + growth > max_size
2068 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2069 {
2070 edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT;
2071 report_inline_failed_reason (edge);
2072 resolve_noninline_speculation (&edge_heap, edge);
2073 continue;
2074 }
2075
2076 if (!want_inline_small_function_p (edge, true))
2077 {
2078 resolve_noninline_speculation (&edge_heap, edge);
2079 continue;
2080 }
2081
2082 /* Heuristics for inlining small functions work poorly for
2083 recursive calls where we do effects similar to loop unrolling.
2084 When inlining such edge seems profitable, leave decision on
2085 specific inliner. */
2086 if (edge->recursive_p ())
2087 {
2088 where = edge->caller;
2089 if (where->inlined_to)
2090 where = where->inlined_to;
2091 if (!recursive_inlining (edge,
2092 opt_for_fn (edge->caller->decl,
2093 flag_indirect_inlining)
2094 ? &new_indirect_edges : NULL))
2095 {
2096 edge->inline_failed = CIF_RECURSIVE_INLINING;
2097 resolve_noninline_speculation (&edge_heap, edge);
2098 continue;
2099 }
2100 reset_edge_caches (where);
2101 /* Recursive inliner inlines all recursive calls of the function
2102 at once. Consequently we need to update all callee keys. */
2103 if (opt_for_fn (edge->caller->decl, flag_indirect_inlining))
2104 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2105 update_callee_keys (&edge_heap, where, updated_nodes);
2106 bitmap_clear (updated_nodes);
2107 }
2108 else
2109 {
2110 struct cgraph_node *outer_node = NULL;
2111 int depth = 0;
2112
2113 /* Consider the case where self recursive function A is inlined
2114 into B. This is desired optimization in some cases, since it
2115 leads to effect similar of loop peeling and we might completely
2116 optimize out the recursive call. However we must be extra
2117 selective. */
2118
2119 where = edge->caller;
2120 while (where->inlined_to)
2121 {
2122 if (where->decl == callee->decl)
2123 outer_node = where, depth++;
2124 where = where->callers->caller;
2125 }
2126 if (outer_node
2127 && !want_inline_self_recursive_call_p (edge, outer_node,
2128 true, depth))
2129 {
2130 edge->inline_failed
2131 = (DECL_DISREGARD_INLINE_LIMITS (edge->callee->decl)
2132 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
2133 resolve_noninline_speculation (&edge_heap, edge);
2134 continue;
2135 }
2136 else if (depth && dump_file)
2137 fprintf (dump_file, " Peeling recursion with depth %i\n", depth);
2138
2139 gcc_checking_assert (!callee->inlined_to);
2140
2141 int old_size = ipa_size_summaries->get (where)->size;
2142 sreal old_time = ipa_fn_summaries->get (where)->time;
2143
2144 inline_call (edge, true, &new_indirect_edges, &overall_size, true);
2145 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2146
2147 reset_edge_caches (edge->callee);
2148
2149 /* If caller's size and time increased we do not need to update
2150 all edges becuase badness is not going to decrease. */
2151 if (old_size <= ipa_size_summaries->get (where)->size
2152 && old_time <= ipa_fn_summaries->get (where)->time
2153 && 0)
2154 update_callee_keys (&edge_heap, edge->callee, updated_nodes);
2155 else
2156 update_callee_keys (&edge_heap, where, updated_nodes);
2157 }
2158 where = edge->caller;
2159 if (where->inlined_to)
2160 where = where->inlined_to;
2161
2162 /* Our profitability metric can depend on local properties
2163 such as number of inlinable calls and size of the function body.
2164 After inlining these properties might change for the function we
2165 inlined into (since it's body size changed) and for the functions
2166 called by function we inlined (since number of it inlinable callers
2167 might change). */
2168 update_caller_keys (&edge_heap, where, updated_nodes, NULL);
2169 /* Offline copy count has possibly changed, recompute if profile is
2170 available. */
2171 struct cgraph_node *n = cgraph_node::get (edge->callee->decl);
2172 if (n != edge->callee && n->analyzed && n->count.ipa ().initialized_p ())
2173 update_callee_keys (&edge_heap, n, updated_nodes);
2174 bitmap_clear (updated_nodes);
2175
2176 if (dump_enabled_p ())
2177 {
2178 ipa_fn_summary *s = ipa_fn_summaries->get (where);
2179
2180 /* dump_printf can't handle %+i. */
2181 char buf_net_change[100];
2182 snprintf (buf_net_change, sizeof buf_net_change, "%+i",
2183 overall_size - old_size);
2184
2185 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, edge->call_stmt,
2186 " Inlined %C into %C which now has time %f and "
2187 "size %i, net change of %s.\n",
2188 edge->callee, edge->caller,
2189 s->time.to_double (),
2190 ipa_size_summaries->get (edge->caller)->size,
2191 buf_net_change);
2192 }
2193 if (min_size > overall_size)
2194 {
2195 min_size = overall_size;
2196 max_size = compute_max_insns (min_size);
2197
2198 if (dump_file)
2199 fprintf (dump_file, "New minimal size reached: %i\n", min_size);
2200 }
2201 }
2202
2203 free_growth_caches ();
2204 if (dump_enabled_p ())
2205 dump_printf (MSG_NOTE,
2206 "Unit growth for small function inlining: %i->%i (%i%%)\n",
2207 initial_size, overall_size,
2208 initial_size ? overall_size * 100 / (initial_size) - 100: 0);
2209 symtab->remove_edge_removal_hook (edge_removal_hook_holder);
2210 }
2211
2212 /* Flatten NODE. Performed both during early inlining and
2213 at IPA inlining time. */
2214
2215 static void
2216 flatten_function (struct cgraph_node *node, bool early, bool update)
2217 {
2218 struct cgraph_edge *e;
2219
2220 /* We shouldn't be called recursively when we are being processed. */
2221 gcc_assert (node->aux == NULL);
2222
2223 node->aux = (void *) node;
2224
2225 for (e = node->callees; e; e = e->next_callee)
2226 {
2227 struct cgraph_node *orig_callee;
2228 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2229
2230 /* We've hit cycle? It is time to give up. */
2231 if (callee->aux)
2232 {
2233 if (dump_enabled_p ())
2234 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2235 "Not inlining %C into %C to avoid cycle.\n",
2236 callee, e->caller);
2237 if (cgraph_inline_failed_type (e->inline_failed) != CIF_FINAL_ERROR)
2238 e->inline_failed = CIF_RECURSIVE_INLINING;
2239 continue;
2240 }
2241
2242 /* When the edge is already inlined, we just need to recurse into
2243 it in order to fully flatten the leaves. */
2244 if (!e->inline_failed)
2245 {
2246 flatten_function (callee, early, false);
2247 continue;
2248 }
2249
2250 /* Flatten attribute needs to be processed during late inlining. For
2251 extra code quality we however do flattening during early optimization,
2252 too. */
2253 if (!early
2254 ? !can_inline_edge_p (e, true)
2255 && !can_inline_edge_by_limits_p (e, true)
2256 : !can_early_inline_edge_p (e))
2257 continue;
2258
2259 if (e->recursive_p ())
2260 {
2261 if (dump_enabled_p ())
2262 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2263 "Not inlining: recursive call.\n");
2264 continue;
2265 }
2266
2267 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl))
2268 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
2269 {
2270 if (dump_enabled_p ())
2271 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2272 "Not inlining: SSA form does not match.\n");
2273 continue;
2274 }
2275
2276 /* Inline the edge and flatten the inline clone. Avoid
2277 recursing through the original node if the node was cloned. */
2278 if (dump_enabled_p ())
2279 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2280 " Inlining %C into %C.\n",
2281 callee, e->caller);
2282 orig_callee = callee;
2283 inline_call (e, true, NULL, NULL, false);
2284 if (e->callee != orig_callee)
2285 orig_callee->aux = (void *) node;
2286 flatten_function (e->callee, early, false);
2287 if (e->callee != orig_callee)
2288 orig_callee->aux = NULL;
2289 }
2290
2291 node->aux = NULL;
2292 cgraph_node *where = node->inlined_to ? node->inlined_to : node;
2293 if (update && opt_for_fn (where->decl, optimize))
2294 ipa_update_overall_fn_summary (where);
2295 }
2296
2297 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases.
2298 DATA points to number of calls originally found so we avoid infinite
2299 recursion. */
2300
2301 static bool
2302 inline_to_all_callers_1 (struct cgraph_node *node, void *data,
2303 hash_set<cgraph_node *> *callers)
2304 {
2305 int *num_calls = (int *)data;
2306 bool callee_removed = false;
2307
2308 while (node->callers && !node->inlined_to)
2309 {
2310 struct cgraph_node *caller = node->callers->caller;
2311
2312 if (!can_inline_edge_p (node->callers, true)
2313 || !can_inline_edge_by_limits_p (node->callers, true)
2314 || node->callers->recursive_p ())
2315 {
2316 if (dump_file)
2317 fprintf (dump_file, "Uninlinable call found; giving up.\n");
2318 *num_calls = 0;
2319 return false;
2320 }
2321
2322 if (dump_file)
2323 {
2324 cgraph_node *ultimate = node->ultimate_alias_target ();
2325 fprintf (dump_file,
2326 "\nInlining %s size %i.\n",
2327 ultimate->name (),
2328 ipa_size_summaries->get (ultimate)->size);
2329 fprintf (dump_file,
2330 " Called once from %s %i insns.\n",
2331 node->callers->caller->name (),
2332 ipa_size_summaries->get (node->callers->caller)->size);
2333 }
2334
2335 /* Remember which callers we inlined to, delaying updating the
2336 overall summary. */
2337 callers->add (node->callers->caller);
2338 inline_call (node->callers, true, NULL, NULL, false, &callee_removed);
2339 if (dump_file)
2340 fprintf (dump_file,
2341 " Inlined into %s which now has %i size\n",
2342 caller->name (),
2343 ipa_size_summaries->get (caller)->size);
2344 if (!(*num_calls)--)
2345 {
2346 if (dump_file)
2347 fprintf (dump_file, "New calls found; giving up.\n");
2348 return callee_removed;
2349 }
2350 if (callee_removed)
2351 return true;
2352 }
2353 return false;
2354 }
2355
2356 /* Wrapper around inline_to_all_callers_1 doing delayed overall summary
2357 update. */
2358
2359 static bool
2360 inline_to_all_callers (struct cgraph_node *node, void *data)
2361 {
2362 hash_set<cgraph_node *> callers;
2363 bool res = inline_to_all_callers_1 (node, data, &callers);
2364 /* Perform the delayed update of the overall summary of all callers
2365 processed. This avoids quadratic behavior in the cases where
2366 we have a lot of calls to the same function. */
2367 for (hash_set<cgraph_node *>::iterator i = callers.begin ();
2368 i != callers.end (); ++i)
2369 ipa_update_overall_fn_summary ((*i)->inlined_to ? (*i)->inlined_to : *i);
2370 return res;
2371 }
2372
2373 /* Output overall time estimate. */
2374 static void
2375 dump_overall_stats (void)
2376 {
2377 sreal sum_weighted = 0, sum = 0;
2378 struct cgraph_node *node;
2379
2380 FOR_EACH_DEFINED_FUNCTION (node)
2381 if (!node->inlined_to
2382 && !node->alias)
2383 {
2384 ipa_fn_summary *s = ipa_fn_summaries->get (node);
2385 if (s != NULL)
2386 {
2387 sum += s->time;
2388 if (node->count.ipa ().initialized_p ())
2389 sum_weighted += s->time * node->count.ipa ().to_gcov_type ();
2390 }
2391 }
2392 fprintf (dump_file, "Overall time estimate: "
2393 "%f weighted by profile: "
2394 "%f\n", sum.to_double (), sum_weighted.to_double ());
2395 }
2396
2397 /* Output some useful stats about inlining. */
2398
2399 static void
2400 dump_inline_stats (void)
2401 {
2402 int64_t inlined_cnt = 0, inlined_indir_cnt = 0;
2403 int64_t inlined_virt_cnt = 0, inlined_virt_indir_cnt = 0;
2404 int64_t noninlined_cnt = 0, noninlined_indir_cnt = 0;
2405 int64_t noninlined_virt_cnt = 0, noninlined_virt_indir_cnt = 0;
2406 int64_t inlined_speculative = 0, inlined_speculative_ply = 0;
2407 int64_t indirect_poly_cnt = 0, indirect_cnt = 0;
2408 int64_t reason[CIF_N_REASONS][2];
2409 sreal reason_freq[CIF_N_REASONS];
2410 int i;
2411 struct cgraph_node *node;
2412
2413 memset (reason, 0, sizeof (reason));
2414 for (i=0; i < CIF_N_REASONS; i++)
2415 reason_freq[i] = 0;
2416 FOR_EACH_DEFINED_FUNCTION (node)
2417 {
2418 struct cgraph_edge *e;
2419 for (e = node->callees; e; e = e->next_callee)
2420 {
2421 if (e->inline_failed)
2422 {
2423 if (e->count.ipa ().initialized_p ())
2424 reason[(int) e->inline_failed][0] += e->count.ipa ().to_gcov_type ();
2425 reason_freq[(int) e->inline_failed] += e->sreal_frequency ();
2426 reason[(int) e->inline_failed][1] ++;
2427 if (DECL_VIRTUAL_P (e->callee->decl)
2428 && e->count.ipa ().initialized_p ())
2429 {
2430 if (e->indirect_inlining_edge)
2431 noninlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2432 else
2433 noninlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2434 }
2435 else if (e->count.ipa ().initialized_p ())
2436 {
2437 if (e->indirect_inlining_edge)
2438 noninlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2439 else
2440 noninlined_cnt += e->count.ipa ().to_gcov_type ();
2441 }
2442 }
2443 else if (e->count.ipa ().initialized_p ())
2444 {
2445 if (e->speculative)
2446 {
2447 if (DECL_VIRTUAL_P (e->callee->decl))
2448 inlined_speculative_ply += e->count.ipa ().to_gcov_type ();
2449 else
2450 inlined_speculative += e->count.ipa ().to_gcov_type ();
2451 }
2452 else if (DECL_VIRTUAL_P (e->callee->decl))
2453 {
2454 if (e->indirect_inlining_edge)
2455 inlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2456 else
2457 inlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2458 }
2459 else
2460 {
2461 if (e->indirect_inlining_edge)
2462 inlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2463 else
2464 inlined_cnt += e->count.ipa ().to_gcov_type ();
2465 }
2466 }
2467 }
2468 for (e = node->indirect_calls; e; e = e->next_callee)
2469 if (e->indirect_info->polymorphic
2470 & e->count.ipa ().initialized_p ())
2471 indirect_poly_cnt += e->count.ipa ().to_gcov_type ();
2472 else if (e->count.ipa ().initialized_p ())
2473 indirect_cnt += e->count.ipa ().to_gcov_type ();
2474 }
2475 if (max_count.initialized_p ())
2476 {
2477 fprintf (dump_file,
2478 "Inlined %" PRId64 " + speculative "
2479 "%" PRId64 " + speculative polymorphic "
2480 "%" PRId64 " + previously indirect "
2481 "%" PRId64 " + virtual "
2482 "%" PRId64 " + virtual and previously indirect "
2483 "%" PRId64 "\n" "Not inlined "
2484 "%" PRId64 " + previously indirect "
2485 "%" PRId64 " + virtual "
2486 "%" PRId64 " + virtual and previously indirect "
2487 "%" PRId64 " + stil indirect "
2488 "%" PRId64 " + still indirect polymorphic "
2489 "%" PRId64 "\n", inlined_cnt,
2490 inlined_speculative, inlined_speculative_ply,
2491 inlined_indir_cnt, inlined_virt_cnt, inlined_virt_indir_cnt,
2492 noninlined_cnt, noninlined_indir_cnt, noninlined_virt_cnt,
2493 noninlined_virt_indir_cnt, indirect_cnt, indirect_poly_cnt);
2494 fprintf (dump_file, "Removed speculations ");
2495 spec_rem.dump (dump_file);
2496 fprintf (dump_file, "\n");
2497 }
2498 dump_overall_stats ();
2499 fprintf (dump_file, "\nWhy inlining failed?\n");
2500 for (i = 0; i < CIF_N_REASONS; i++)
2501 if (reason[i][1])
2502 fprintf (dump_file, "%-50s: %8i calls, %8f freq, %" PRId64" count\n",
2503 cgraph_inline_failed_string ((cgraph_inline_failed_t) i),
2504 (int) reason[i][1], reason_freq[i].to_double (), reason[i][0]);
2505 }
2506
2507 /* Called when node is removed. */
2508
2509 static void
2510 flatten_remove_node_hook (struct cgraph_node *node, void *data)
2511 {
2512 if (lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) == NULL)
2513 return;
2514
2515 hash_set<struct cgraph_node *> *removed
2516 = (hash_set<struct cgraph_node *> *) data;
2517 removed->add (node);
2518 }
2519
2520 /* Decide on the inlining. We do so in the topological order to avoid
2521 expenses on updating data structures. */
2522
2523 static unsigned int
2524 ipa_inline (void)
2525 {
2526 struct cgraph_node *node;
2527 int nnodes;
2528 struct cgraph_node **order;
2529 int i, j;
2530 int cold;
2531 bool remove_functions = false;
2532
2533 order = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count);
2534
2535 if (dump_file)
2536 ipa_dump_fn_summaries (dump_file);
2537
2538 nnodes = ipa_reverse_postorder (order);
2539 spec_rem = profile_count::zero ();
2540
2541 FOR_EACH_FUNCTION (node)
2542 {
2543 node->aux = 0;
2544
2545 /* Recompute the default reasons for inlining because they may have
2546 changed during merging. */
2547 if (in_lto_p)
2548 {
2549 for (cgraph_edge *e = node->callees; e; e = e->next_callee)
2550 {
2551 gcc_assert (e->inline_failed);
2552 initialize_inline_failed (e);
2553 }
2554 for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee)
2555 initialize_inline_failed (e);
2556 }
2557 }
2558
2559 if (dump_file)
2560 fprintf (dump_file, "\nFlattening functions:\n");
2561
2562 /* First shrink order array, so that it only contains nodes with
2563 flatten attribute. */
2564 for (i = nnodes - 1, j = i; i >= 0; i--)
2565 {
2566 node = order[i];
2567 if (node->definition
2568 && lookup_attribute ("flatten",
2569 DECL_ATTRIBUTES (node->decl)) != NULL)
2570 order[j--] = order[i];
2571 }
2572
2573 /* After the above loop, order[j + 1] ... order[nnodes - 1] contain
2574 nodes with flatten attribute. If there is more than one such
2575 node, we need to register a node removal hook, as flatten_function
2576 could remove other nodes with flatten attribute. See PR82801. */
2577 struct cgraph_node_hook_list *node_removal_hook_holder = NULL;
2578 hash_set<struct cgraph_node *> *flatten_removed_nodes = NULL;
2579 if (j < nnodes - 2)
2580 {
2581 flatten_removed_nodes = new hash_set<struct cgraph_node *>;
2582 node_removal_hook_holder
2583 = symtab->add_cgraph_removal_hook (&flatten_remove_node_hook,
2584 flatten_removed_nodes);
2585 }
2586
2587 /* In the first pass handle functions to be flattened. Do this with
2588 a priority so none of our later choices will make this impossible. */
2589 for (i = nnodes - 1; i > j; i--)
2590 {
2591 node = order[i];
2592 if (flatten_removed_nodes
2593 && flatten_removed_nodes->contains (node))
2594 continue;
2595
2596 /* Handle nodes to be flattened.
2597 Ideally when processing callees we stop inlining at the
2598 entry of cycles, possibly cloning that entry point and
2599 try to flatten itself turning it into a self-recursive
2600 function. */
2601 if (dump_file)
2602 fprintf (dump_file, "Flattening %s\n", node->name ());
2603 flatten_function (node, false, true);
2604 }
2605
2606 if (j < nnodes - 2)
2607 {
2608 symtab->remove_cgraph_removal_hook (node_removal_hook_holder);
2609 delete flatten_removed_nodes;
2610 }
2611 free (order);
2612
2613 if (dump_file)
2614 dump_overall_stats ();
2615
2616 inline_small_functions ();
2617
2618 gcc_assert (symtab->state == IPA_SSA);
2619 symtab->state = IPA_SSA_AFTER_INLINING;
2620 /* Do first after-inlining removal. We want to remove all "stale" extern
2621 inline functions and virtual functions so we really know what is called
2622 once. */
2623 symtab->remove_unreachable_nodes (dump_file);
2624
2625 /* Inline functions with a property that after inlining into all callers the
2626 code size will shrink because the out-of-line copy is eliminated.
2627 We do this regardless on the callee size as long as function growth limits
2628 are met. */
2629 if (dump_file)
2630 fprintf (dump_file,
2631 "\nDeciding on functions to be inlined into all callers and "
2632 "removing useless speculations:\n");
2633
2634 /* Inlining one function called once has good chance of preventing
2635 inlining other function into the same callee. Ideally we should
2636 work in priority order, but probably inlining hot functions first
2637 is good cut without the extra pain of maintaining the queue.
2638
2639 ??? this is not really fitting the bill perfectly: inlining function
2640 into callee often leads to better optimization of callee due to
2641 increased context for optimization.
2642 For example if main() function calls a function that outputs help
2643 and then function that does the main optmization, we should inline
2644 the second with priority even if both calls are cold by themselves.
2645
2646 We probably want to implement new predicate replacing our use of
2647 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
2648 to be hot. */
2649 for (cold = 0; cold <= 1; cold ++)
2650 {
2651 FOR_EACH_DEFINED_FUNCTION (node)
2652 {
2653 struct cgraph_edge *edge, *next;
2654 bool update=false;
2655
2656 if (!opt_for_fn (node->decl, optimize)
2657 || !opt_for_fn (node->decl, flag_inline_functions_called_once))
2658 continue;
2659
2660 for (edge = node->callees; edge; edge = next)
2661 {
2662 next = edge->next_callee;
2663 if (edge->speculative && !speculation_useful_p (edge, false))
2664 {
2665 if (edge->count.ipa ().initialized_p ())
2666 spec_rem += edge->count.ipa ();
2667 edge->resolve_speculation ();
2668 update = true;
2669 remove_functions = true;
2670 }
2671 }
2672 if (update)
2673 {
2674 struct cgraph_node *where = node->inlined_to
2675 ? node->inlined_to : node;
2676 reset_edge_caches (where);
2677 ipa_update_overall_fn_summary (where);
2678 }
2679 if (want_inline_function_to_all_callers_p (node, cold))
2680 {
2681 int num_calls = 0;
2682 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
2683 true);
2684 while (node->call_for_symbol_and_aliases
2685 (inline_to_all_callers, &num_calls, true))
2686 ;
2687 remove_functions = true;
2688 }
2689 }
2690 }
2691
2692 /* Free ipa-prop structures if they are no longer needed. */
2693 ipa_free_all_structures_after_iinln ();
2694
2695 if (dump_enabled_p ())
2696 dump_printf (MSG_NOTE,
2697 "\nInlined %i calls, eliminated %i functions\n\n",
2698 ncalls_inlined, nfunctions_inlined);
2699 if (dump_file)
2700 dump_inline_stats ();
2701
2702 if (dump_file)
2703 ipa_dump_fn_summaries (dump_file);
2704 return remove_functions ? TODO_remove_functions : 0;
2705 }
2706
2707 /* Inline always-inline function calls in NODE. */
2708
2709 static bool
2710 inline_always_inline_functions (struct cgraph_node *node)
2711 {
2712 struct cgraph_edge *e;
2713 bool inlined = false;
2714
2715 for (e = node->callees; e; e = e->next_callee)
2716 {
2717 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2718 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2719 continue;
2720
2721 if (e->recursive_p ())
2722 {
2723 if (dump_enabled_p ())
2724 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2725 " Not inlining recursive call to %C.\n",
2726 e->callee);
2727 e->inline_failed = CIF_RECURSIVE_INLINING;
2728 continue;
2729 }
2730
2731 if (!can_early_inline_edge_p (e))
2732 {
2733 /* Set inlined to true if the callee is marked "always_inline" but
2734 is not inlinable. This will allow flagging an error later in
2735 expand_call_inline in tree-inline.c. */
2736 if (lookup_attribute ("always_inline",
2737 DECL_ATTRIBUTES (callee->decl)) != NULL)
2738 inlined = true;
2739 continue;
2740 }
2741
2742 if (dump_enabled_p ())
2743 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2744 " Inlining %C into %C (always_inline).\n",
2745 e->callee, e->caller);
2746 inline_call (e, true, NULL, NULL, false);
2747 inlined = true;
2748 }
2749 if (inlined)
2750 ipa_update_overall_fn_summary (node);
2751
2752 return inlined;
2753 }
2754
2755 /* Decide on the inlining. We do so in the topological order to avoid
2756 expenses on updating data structures. */
2757
2758 static bool
2759 early_inline_small_functions (struct cgraph_node *node)
2760 {
2761 struct cgraph_edge *e;
2762 bool inlined = false;
2763
2764 for (e = node->callees; e; e = e->next_callee)
2765 {
2766 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2767
2768 /* We can enounter not-yet-analyzed function during
2769 early inlining on callgraphs with strongly
2770 connected components. */
2771 ipa_fn_summary *s = ipa_fn_summaries->get (callee);
2772 if (s == NULL || !s->inlinable || !e->inline_failed)
2773 continue;
2774
2775 /* Do not consider functions not declared inline. */
2776 if (!DECL_DECLARED_INLINE_P (callee->decl)
2777 && !opt_for_fn (node->decl, flag_inline_small_functions)
2778 && !opt_for_fn (node->decl, flag_inline_functions))
2779 continue;
2780
2781 if (dump_enabled_p ())
2782 dump_printf_loc (MSG_NOTE, e->call_stmt,
2783 "Considering inline candidate %C.\n",
2784 callee);
2785
2786 if (!can_early_inline_edge_p (e))
2787 continue;
2788
2789 if (e->recursive_p ())
2790 {
2791 if (dump_enabled_p ())
2792 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2793 " Not inlining: recursive call.\n");
2794 continue;
2795 }
2796
2797 if (!want_early_inline_function_p (e))
2798 continue;
2799
2800 if (dump_enabled_p ())
2801 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2802 " Inlining %C into %C.\n",
2803 callee, e->caller);
2804 inline_call (e, true, NULL, NULL, false);
2805 inlined = true;
2806 }
2807
2808 if (inlined)
2809 ipa_update_overall_fn_summary (node);
2810
2811 return inlined;
2812 }
2813
2814 unsigned int
2815 early_inliner (function *fun)
2816 {
2817 struct cgraph_node *node = cgraph_node::get (current_function_decl);
2818 struct cgraph_edge *edge;
2819 unsigned int todo = 0;
2820 int iterations = 0;
2821 bool inlined = false;
2822
2823 if (seen_error ())
2824 return 0;
2825
2826 /* Do nothing if datastructures for ipa-inliner are already computed. This
2827 happens when some pass decides to construct new function and
2828 cgraph_add_new_function calls lowering passes and early optimization on
2829 it. This may confuse ourself when early inliner decide to inline call to
2830 function clone, because function clones don't have parameter list in
2831 ipa-prop matching their signature. */
2832 if (ipa_node_params_sum)
2833 return 0;
2834
2835 if (flag_checking)
2836 node->verify ();
2837 node->remove_all_references ();
2838
2839 /* Even when not optimizing or not inlining inline always-inline
2840 functions. */
2841 inlined = inline_always_inline_functions (node);
2842
2843 if (!optimize
2844 || flag_no_inline
2845 || !flag_early_inlining
2846 /* Never inline regular functions into always-inline functions
2847 during incremental inlining. This sucks as functions calling
2848 always inline functions will get less optimized, but at the
2849 same time inlining of functions calling always inline
2850 function into an always inline function might introduce
2851 cycles of edges to be always inlined in the callgraph.
2852
2853 We might want to be smarter and just avoid this type of inlining. */
2854 || (DECL_DISREGARD_INLINE_LIMITS (node->decl)
2855 && lookup_attribute ("always_inline",
2856 DECL_ATTRIBUTES (node->decl))))
2857 ;
2858 else if (lookup_attribute ("flatten",
2859 DECL_ATTRIBUTES (node->decl)) != NULL)
2860 {
2861 /* When the function is marked to be flattened, recursively inline
2862 all calls in it. */
2863 if (dump_enabled_p ())
2864 dump_printf (MSG_OPTIMIZED_LOCATIONS,
2865 "Flattening %C\n", node);
2866 flatten_function (node, true, true);
2867 inlined = true;
2868 }
2869 else
2870 {
2871 /* If some always_inline functions was inlined, apply the changes.
2872 This way we will not account always inline into growth limits and
2873 moreover we will inline calls from always inlines that we skipped
2874 previously because of conditional above. */
2875 if (inlined)
2876 {
2877 timevar_push (TV_INTEGRATION);
2878 todo |= optimize_inline_calls (current_function_decl);
2879 /* optimize_inline_calls call above might have introduced new
2880 statements that don't have inline parameters computed. */
2881 for (edge = node->callees; edge; edge = edge->next_callee)
2882 {
2883 /* We can enounter not-yet-analyzed function during
2884 early inlining on callgraphs with strongly
2885 connected components. */
2886 ipa_call_summary *es = ipa_call_summaries->get_create (edge);
2887 es->call_stmt_size
2888 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2889 es->call_stmt_time
2890 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2891 }
2892 ipa_update_overall_fn_summary (node);
2893 inlined = false;
2894 timevar_pop (TV_INTEGRATION);
2895 }
2896 /* We iterate incremental inlining to get trivial cases of indirect
2897 inlining. */
2898 while (iterations < param_early_inliner_max_iterations
2899 && early_inline_small_functions (node))
2900 {
2901 timevar_push (TV_INTEGRATION);
2902 todo |= optimize_inline_calls (current_function_decl);
2903
2904 /* Technically we ought to recompute inline parameters so the new
2905 iteration of early inliner works as expected. We however have
2906 values approximately right and thus we only need to update edge
2907 info that might be cleared out for newly discovered edges. */
2908 for (edge = node->callees; edge; edge = edge->next_callee)
2909 {
2910 /* We have no summary for new bound store calls yet. */
2911 ipa_call_summary *es = ipa_call_summaries->get_create (edge);
2912 es->call_stmt_size
2913 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2914 es->call_stmt_time
2915 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2916 }
2917 if (iterations < param_early_inliner_max_iterations - 1)
2918 ipa_update_overall_fn_summary (node);
2919 timevar_pop (TV_INTEGRATION);
2920 iterations++;
2921 inlined = false;
2922 }
2923 if (dump_file)
2924 fprintf (dump_file, "Iterations: %i\n", iterations);
2925 }
2926
2927 if (inlined)
2928 {
2929 timevar_push (TV_INTEGRATION);
2930 todo |= optimize_inline_calls (current_function_decl);
2931 timevar_pop (TV_INTEGRATION);
2932 }
2933
2934 fun->always_inline_functions_inlined = true;
2935
2936 return todo;
2937 }
2938
2939 /* Do inlining of small functions. Doing so early helps profiling and other
2940 passes to be somewhat more effective and avoids some code duplication in
2941 later real inlining pass for testcases with very many function calls. */
2942
2943 namespace {
2944
2945 const pass_data pass_data_early_inline =
2946 {
2947 GIMPLE_PASS, /* type */
2948 "einline", /* name */
2949 OPTGROUP_INLINE, /* optinfo_flags */
2950 TV_EARLY_INLINING, /* tv_id */
2951 PROP_ssa, /* properties_required */
2952 0, /* properties_provided */
2953 0, /* properties_destroyed */
2954 0, /* todo_flags_start */
2955 0, /* todo_flags_finish */
2956 };
2957
2958 class pass_early_inline : public gimple_opt_pass
2959 {
2960 public:
2961 pass_early_inline (gcc::context *ctxt)
2962 : gimple_opt_pass (pass_data_early_inline, ctxt)
2963 {}
2964
2965 /* opt_pass methods: */
2966 virtual unsigned int execute (function *);
2967
2968 }; // class pass_early_inline
2969
2970 unsigned int
2971 pass_early_inline::execute (function *fun)
2972 {
2973 return early_inliner (fun);
2974 }
2975
2976 } // anon namespace
2977
2978 gimple_opt_pass *
2979 make_pass_early_inline (gcc::context *ctxt)
2980 {
2981 return new pass_early_inline (ctxt);
2982 }
2983
2984 namespace {
2985
2986 const pass_data pass_data_ipa_inline =
2987 {
2988 IPA_PASS, /* type */
2989 "inline", /* name */
2990 OPTGROUP_INLINE, /* optinfo_flags */
2991 TV_IPA_INLINING, /* tv_id */
2992 0, /* properties_required */
2993 0, /* properties_provided */
2994 0, /* properties_destroyed */
2995 0, /* todo_flags_start */
2996 ( TODO_dump_symtab ), /* todo_flags_finish */
2997 };
2998
2999 class pass_ipa_inline : public ipa_opt_pass_d
3000 {
3001 public:
3002 pass_ipa_inline (gcc::context *ctxt)
3003 : ipa_opt_pass_d (pass_data_ipa_inline, ctxt,
3004 NULL, /* generate_summary */
3005 NULL, /* write_summary */
3006 NULL, /* read_summary */
3007 NULL, /* write_optimization_summary */
3008 NULL, /* read_optimization_summary */
3009 NULL, /* stmt_fixup */
3010 0, /* function_transform_todo_flags_start */
3011 inline_transform, /* function_transform */
3012 NULL) /* variable_transform */
3013 {}
3014
3015 /* opt_pass methods: */
3016 virtual unsigned int execute (function *) { return ipa_inline (); }
3017
3018 }; // class pass_ipa_inline
3019
3020 } // anon namespace
3021
3022 ipa_opt_pass_d *
3023 make_pass_ipa_inline (gcc::context *ctxt)
3024 {
3025 return new pass_ipa_inline (ctxt);
3026 }