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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 "params.h"
109 #include "profile.h"
110 #include "symbol-summary.h"
111 #include "tree-vrp.h"
112 #include "ipa-prop.h"
113 #include "ipa-fnsummary.h"
114 #include "ipa-inline.h"
115 #include "ipa-utils.h"
116 #include "sreal.h"
117 #include "auto-profile.h"
118 #include "builtins.h"
119 #include "fibonacci_heap.h"
120 #include "stringpool.h"
121 #include "attribs.h"
122 #include "asan.h"
123
124 typedef fibonacci_heap <sreal, cgraph_edge> edge_heap_t;
125 typedef fibonacci_node <sreal, cgraph_edge> edge_heap_node_t;
126
127 /* Statistics we collect about inlining algorithm. */
128 static int overall_size;
129 static profile_count max_count;
130 static profile_count spec_rem;
131
132 /* Return false when inlining edge E would lead to violating
133 limits on function unit growth or stack usage growth.
134
135 The relative function body growth limit is present generally
136 to avoid problems with non-linear behavior of the compiler.
137 To allow inlining huge functions into tiny wrapper, the limit
138 is always based on the bigger of the two functions considered.
139
140 For stack growth limits we always base the growth in stack usage
141 of the callers. We want to prevent applications from segfaulting
142 on stack overflow when functions with huge stack frames gets
143 inlined. */
144
145 static bool
146 caller_growth_limits (struct cgraph_edge *e)
147 {
148 struct cgraph_node *to = e->caller;
149 struct cgraph_node *what = e->callee->ultimate_alias_target ();
150 int newsize;
151 int limit = 0;
152 HOST_WIDE_INT stack_size_limit = 0, inlined_stack;
153 ipa_fn_summary *info, *what_info;
154 ipa_fn_summary *outer_info = ipa_fn_summaries->get (to);
155
156 /* Look for function e->caller is inlined to. While doing
157 so work out the largest function body on the way. As
158 described above, we want to base our function growth
159 limits based on that. Not on the self size of the
160 outer function, not on the self size of inline code
161 we immediately inline to. This is the most relaxed
162 interpretation of the rule "do not grow large functions
163 too much in order to prevent compiler from exploding". */
164 while (true)
165 {
166 info = ipa_fn_summaries->get (to);
167 if (limit < info->self_size)
168 limit = info->self_size;
169 if (stack_size_limit < info->estimated_self_stack_size)
170 stack_size_limit = info->estimated_self_stack_size;
171 if (to->global.inlined_to)
172 to = to->callers->caller;
173 else
174 break;
175 }
176
177 what_info = ipa_fn_summaries->get (what);
178
179 if (limit < what_info->self_size)
180 limit = what_info->self_size;
181
182 limit += limit * PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH) / 100;
183
184 /* Check the size after inlining against the function limits. But allow
185 the function to shrink if it went over the limits by forced inlining. */
186 newsize = estimate_size_after_inlining (to, e);
187 if (newsize >= info->size
188 && newsize > PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS)
189 && newsize > limit)
190 {
191 e->inline_failed = CIF_LARGE_FUNCTION_GROWTH_LIMIT;
192 return false;
193 }
194
195 if (!what_info->estimated_stack_size)
196 return true;
197
198 /* FIXME: Stack size limit often prevents inlining in Fortran programs
199 due to large i/o datastructures used by the Fortran front-end.
200 We ought to ignore this limit when we know that the edge is executed
201 on every invocation of the caller (i.e. its call statement dominates
202 exit block). We do not track this information, yet. */
203 stack_size_limit += ((gcov_type)stack_size_limit
204 * PARAM_VALUE (PARAM_STACK_FRAME_GROWTH) / 100);
205
206 inlined_stack = (outer_info->stack_frame_offset
207 + outer_info->estimated_self_stack_size
208 + what_info->estimated_stack_size);
209 /* Check new stack consumption with stack consumption at the place
210 stack is used. */
211 if (inlined_stack > stack_size_limit
212 /* If function already has large stack usage from sibling
213 inline call, we can inline, too.
214 This bit overoptimistically assume that we are good at stack
215 packing. */
216 && inlined_stack > info->estimated_stack_size
217 && inlined_stack > PARAM_VALUE (PARAM_LARGE_STACK_FRAME))
218 {
219 e->inline_failed = CIF_LARGE_STACK_FRAME_GROWTH_LIMIT;
220 return false;
221 }
222 return true;
223 }
224
225 /* Dump info about why inlining has failed. */
226
227 static void
228 report_inline_failed_reason (struct cgraph_edge *e)
229 {
230 if (dump_enabled_p ())
231 {
232 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
233 " not inlinable: %C -> %C, %s\n",
234 e->caller, e->callee,
235 cgraph_inline_failed_string (e->inline_failed));
236 if ((e->inline_failed == CIF_TARGET_OPTION_MISMATCH
237 || e->inline_failed == CIF_OPTIMIZATION_MISMATCH)
238 && e->caller->lto_file_data
239 && e->callee->ultimate_alias_target ()->lto_file_data)
240 {
241 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
242 " LTO objects: %s, %s\n",
243 e->caller->lto_file_data->file_name,
244 e->callee->ultimate_alias_target ()->lto_file_data->file_name);
245 }
246 if (e->inline_failed == CIF_TARGET_OPTION_MISMATCH)
247 if (dump_file)
248 cl_target_option_print_diff
249 (dump_file, 2, target_opts_for_fn (e->caller->decl),
250 target_opts_for_fn (e->callee->ultimate_alias_target ()->decl));
251 if (e->inline_failed == CIF_OPTIMIZATION_MISMATCH)
252 if (dump_file)
253 cl_optimization_print_diff
254 (dump_file, 2, opts_for_fn (e->caller->decl),
255 opts_for_fn (e->callee->ultimate_alias_target ()->decl));
256 }
257 }
258
259 /* Decide whether sanitizer-related attributes allow inlining. */
260
261 static bool
262 sanitize_attrs_match_for_inline_p (const_tree caller, const_tree callee)
263 {
264 if (!caller || !callee)
265 return true;
266
267 /* Allow inlining always_inline functions into no_sanitize_address
268 functions. */
269 if (!sanitize_flags_p (SANITIZE_ADDRESS, caller)
270 && lookup_attribute ("always_inline", DECL_ATTRIBUTES (callee)))
271 return true;
272
273 return ((sanitize_flags_p (SANITIZE_ADDRESS, caller)
274 == sanitize_flags_p (SANITIZE_ADDRESS, callee))
275 && (sanitize_flags_p (SANITIZE_POINTER_COMPARE, caller)
276 == sanitize_flags_p (SANITIZE_POINTER_COMPARE, callee))
277 && (sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, caller)
278 == sanitize_flags_p (SANITIZE_POINTER_SUBTRACT, callee)));
279 }
280
281 /* Used for flags where it is safe to inline when caller's value is
282 grater than callee's. */
283 #define check_maybe_up(flag) \
284 (opts_for_fn (caller->decl)->x_##flag \
285 != opts_for_fn (callee->decl)->x_##flag \
286 && (!always_inline \
287 || opts_for_fn (caller->decl)->x_##flag \
288 < opts_for_fn (callee->decl)->x_##flag))
289 /* Used for flags where it is safe to inline when caller's value is
290 smaller than callee's. */
291 #define check_maybe_down(flag) \
292 (opts_for_fn (caller->decl)->x_##flag \
293 != opts_for_fn (callee->decl)->x_##flag \
294 && (!always_inline \
295 || opts_for_fn (caller->decl)->x_##flag \
296 > opts_for_fn (callee->decl)->x_##flag))
297 /* Used for flags where exact match is needed for correctness. */
298 #define check_match(flag) \
299 (opts_for_fn (caller->decl)->x_##flag \
300 != opts_for_fn (callee->decl)->x_##flag)
301
302 /* Decide if we can inline the edge and possibly update
303 inline_failed reason.
304 We check whether inlining is possible at all and whether
305 caller growth limits allow doing so.
306
307 if REPORT is true, output reason to the dump file. */
308
309 static bool
310 can_inline_edge_p (struct cgraph_edge *e, bool report,
311 bool early = false)
312 {
313 gcc_checking_assert (e->inline_failed);
314
315 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
316 {
317 if (report)
318 report_inline_failed_reason (e);
319 return false;
320 }
321
322 bool inlinable = true;
323 enum availability avail;
324 cgraph_node *caller = e->caller->global.inlined_to
325 ? e->caller->global.inlined_to : e->caller;
326 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
327
328 if (!callee->definition)
329 {
330 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
331 inlinable = false;
332 }
333 if (!early && (!opt_for_fn (callee->decl, optimize)
334 || !opt_for_fn (caller->decl, optimize)))
335 {
336 e->inline_failed = CIF_FUNCTION_NOT_OPTIMIZED;
337 inlinable = false;
338 }
339 else if (callee->calls_comdat_local)
340 {
341 e->inline_failed = CIF_USES_COMDAT_LOCAL;
342 inlinable = false;
343 }
344 else if (avail <= AVAIL_INTERPOSABLE)
345 {
346 e->inline_failed = CIF_OVERWRITABLE;
347 inlinable = false;
348 }
349 /* All edges with call_stmt_cannot_inline_p should have inline_failed
350 initialized to one of FINAL_ERROR reasons. */
351 else if (e->call_stmt_cannot_inline_p)
352 gcc_unreachable ();
353 /* Don't inline if the functions have different EH personalities. */
354 else if (DECL_FUNCTION_PERSONALITY (caller->decl)
355 && DECL_FUNCTION_PERSONALITY (callee->decl)
356 && (DECL_FUNCTION_PERSONALITY (caller->decl)
357 != DECL_FUNCTION_PERSONALITY (callee->decl)))
358 {
359 e->inline_failed = CIF_EH_PERSONALITY;
360 inlinable = false;
361 }
362 /* TM pure functions should not be inlined into non-TM_pure
363 functions. */
364 else if (is_tm_pure (callee->decl) && !is_tm_pure (caller->decl))
365 {
366 e->inline_failed = CIF_UNSPECIFIED;
367 inlinable = false;
368 }
369 /* Check compatibility of target optimization options. */
370 else if (!targetm.target_option.can_inline_p (caller->decl,
371 callee->decl))
372 {
373 e->inline_failed = CIF_TARGET_OPTION_MISMATCH;
374 inlinable = false;
375 }
376 else if (ipa_fn_summaries->get (callee) == NULL
377 || !ipa_fn_summaries->get (callee)->inlinable)
378 {
379 e->inline_failed = CIF_FUNCTION_NOT_INLINABLE;
380 inlinable = false;
381 }
382 /* Don't inline a function with mismatched sanitization attributes. */
383 else if (!sanitize_attrs_match_for_inline_p (caller->decl, callee->decl))
384 {
385 e->inline_failed = CIF_ATTRIBUTE_MISMATCH;
386 inlinable = false;
387 }
388 if (!inlinable && report)
389 report_inline_failed_reason (e);
390 return inlinable;
391 }
392
393 /* Return inlining_insns_single limit for function N */
394
395 static int
396 inline_insns_single (cgraph_node *n)
397 {
398 if (opt_for_fn (n->decl, optimize >= 3))
399 return PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SINGLE);
400 else
401 return PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SINGLE_O2);
402 }
403
404 /* Return inlining_insns_auto limit for function N */
405
406 static int
407 inline_insns_auto (cgraph_node *n)
408 {
409 if (opt_for_fn (n->decl, optimize >= 3))
410 return PARAM_VALUE (PARAM_MAX_INLINE_INSNS_AUTO);
411 else
412 return PARAM_VALUE (PARAM_MAX_INLINE_INSNS_AUTO_O2);
413 }
414
415 /* Decide if we can inline the edge and possibly update
416 inline_failed reason.
417 We check whether inlining is possible at all and whether
418 caller growth limits allow doing so.
419
420 if REPORT is true, output reason to the dump file.
421
422 if DISREGARD_LIMITS is true, ignore size limits. */
423
424 static bool
425 can_inline_edge_by_limits_p (struct cgraph_edge *e, bool report,
426 bool disregard_limits = false, bool early = false)
427 {
428 gcc_checking_assert (e->inline_failed);
429
430 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
431 {
432 if (report)
433 report_inline_failed_reason (e);
434 return false;
435 }
436
437 bool inlinable = true;
438 enum availability avail;
439 cgraph_node *caller = e->caller->global.inlined_to
440 ? e->caller->global.inlined_to : e->caller;
441 cgraph_node *callee = e->callee->ultimate_alias_target (&avail, caller);
442 tree caller_tree = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (caller->decl);
443 tree callee_tree
444 = callee ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (callee->decl) : NULL;
445 /* Check if caller growth allows the inlining. */
446 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl)
447 && !disregard_limits
448 && !lookup_attribute ("flatten",
449 DECL_ATTRIBUTES (caller->decl))
450 && !caller_growth_limits (e))
451 inlinable = false;
452 else if (callee->externally_visible
453 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl)
454 && flag_live_patching == LIVE_PATCHING_INLINE_ONLY_STATIC)
455 {
456 e->inline_failed = CIF_EXTERN_LIVE_ONLY_STATIC;
457 inlinable = false;
458 }
459 /* Don't inline a function with a higher optimization level than the
460 caller. FIXME: this is really just tip of iceberg of handling
461 optimization attribute. */
462 else if (caller_tree != callee_tree)
463 {
464 bool always_inline =
465 (DECL_DISREGARD_INLINE_LIMITS (callee->decl)
466 && lookup_attribute ("always_inline",
467 DECL_ATTRIBUTES (callee->decl)));
468 ipa_fn_summary *caller_info = ipa_fn_summaries->get (caller);
469 ipa_fn_summary *callee_info = ipa_fn_summaries->get (callee);
470
471 /* Until GCC 4.9 we did not check the semantics-altering flags
472 below and inlined across optimization boundaries.
473 Enabling checks below breaks several packages by refusing
474 to inline library always_inline functions. See PR65873.
475 Disable the check for early inlining for now until better solution
476 is found. */
477 if (always_inline && early)
478 ;
479 /* There are some options that change IL semantics which means
480 we cannot inline in these cases for correctness reason.
481 Not even for always_inline declared functions. */
482 else if (check_match (flag_wrapv)
483 || check_match (flag_trapv)
484 || check_match (flag_pcc_struct_return)
485 /* When caller or callee does FP math, be sure FP codegen flags
486 compatible. */
487 || ((caller_info->fp_expressions && callee_info->fp_expressions)
488 && (check_maybe_up (flag_rounding_math)
489 || check_maybe_up (flag_trapping_math)
490 || check_maybe_down (flag_unsafe_math_optimizations)
491 || check_maybe_down (flag_finite_math_only)
492 || check_maybe_up (flag_signaling_nans)
493 || check_maybe_down (flag_cx_limited_range)
494 || check_maybe_up (flag_signed_zeros)
495 || check_maybe_down (flag_associative_math)
496 || check_maybe_down (flag_reciprocal_math)
497 || check_maybe_down (flag_fp_int_builtin_inexact)
498 /* Strictly speaking only when the callee contains function
499 calls that may end up setting errno. */
500 || check_maybe_up (flag_errno_math)))
501 /* We do not want to make code compiled with exceptions to be
502 brought into a non-EH function unless we know that the callee
503 does not throw.
504 This is tracked by DECL_FUNCTION_PERSONALITY. */
505 || (check_maybe_up (flag_non_call_exceptions)
506 && DECL_FUNCTION_PERSONALITY (callee->decl))
507 || (check_maybe_up (flag_exceptions)
508 && DECL_FUNCTION_PERSONALITY (callee->decl))
509 /* When devirtualization is diabled for callee, it is not safe
510 to inline it as we possibly mangled the type info.
511 Allow early inlining of always inlines. */
512 || (!early && check_maybe_down (flag_devirtualize)))
513 {
514 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
515 inlinable = false;
516 }
517 /* gcc.dg/pr43564.c. Apply user-forced inline even at -O0. */
518 else if (always_inline)
519 ;
520 /* When user added an attribute to the callee honor it. */
521 else if (lookup_attribute ("optimize", DECL_ATTRIBUTES (callee->decl))
522 && opts_for_fn (caller->decl) != opts_for_fn (callee->decl))
523 {
524 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
525 inlinable = false;
526 }
527 /* If explicit optimize attribute are not used, the mismatch is caused
528 by different command line options used to build different units.
529 Do not care about COMDAT functions - those are intended to be
530 optimized with the optimization flags of module they are used in.
531 Also do not care about mixing up size/speed optimization when
532 DECL_DISREGARD_INLINE_LIMITS is set. */
533 else if ((callee->merged_comdat
534 && !lookup_attribute ("optimize",
535 DECL_ATTRIBUTES (caller->decl)))
536 || DECL_DISREGARD_INLINE_LIMITS (callee->decl))
537 ;
538 /* If mismatch is caused by merging two LTO units with different
539 optimizationflags we want to be bit nicer. However never inline
540 if one of functions is not optimized at all. */
541 else if (!opt_for_fn (callee->decl, optimize)
542 || !opt_for_fn (caller->decl, optimize))
543 {
544 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
545 inlinable = false;
546 }
547 /* If callee is optimized for size and caller is not, allow inlining if
548 code shrinks or we are in MAX_INLINE_INSNS_SINGLE limit and callee
549 is inline (and thus likely an unified comdat). This will allow caller
550 to run faster. */
551 else if (opt_for_fn (callee->decl, optimize_size)
552 > opt_for_fn (caller->decl, optimize_size))
553 {
554 int growth = estimate_edge_growth (e);
555 if (growth > PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SIZE)
556 && (!DECL_DECLARED_INLINE_P (callee->decl)
557 && growth >= MAX (inline_insns_single (caller),
558 inline_insns_auto (caller))))
559 {
560 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
561 inlinable = false;
562 }
563 }
564 /* If callee is more aggressively optimized for performance than caller,
565 we generally want to inline only cheap (runtime wise) functions. */
566 else if (opt_for_fn (callee->decl, optimize_size)
567 < opt_for_fn (caller->decl, optimize_size)
568 || (opt_for_fn (callee->decl, optimize)
569 > opt_for_fn (caller->decl, optimize)))
570 {
571 if (estimate_edge_time (e)
572 >= 20 + ipa_call_summaries->get (e)->call_stmt_time)
573 {
574 e->inline_failed = CIF_OPTIMIZATION_MISMATCH;
575 inlinable = false;
576 }
577 }
578
579 }
580
581 if (!inlinable && report)
582 report_inline_failed_reason (e);
583 return inlinable;
584 }
585
586
587 /* Return true if the edge E is inlinable during early inlining. */
588
589 static bool
590 can_early_inline_edge_p (struct cgraph_edge *e)
591 {
592 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
593 /* Early inliner might get called at WPA stage when IPA pass adds new
594 function. In this case we cannot really do any of early inlining
595 because function bodies are missing. */
596 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
597 return false;
598 if (!gimple_has_body_p (callee->decl))
599 {
600 e->inline_failed = CIF_BODY_NOT_AVAILABLE;
601 return false;
602 }
603 /* In early inliner some of callees may not be in SSA form yet
604 (i.e. the callgraph is cyclic and we did not process
605 the callee by early inliner, yet). We don't have CIF code for this
606 case; later we will re-do the decision in the real inliner. */
607 if (!gimple_in_ssa_p (DECL_STRUCT_FUNCTION (e->caller->decl))
608 || !gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
609 {
610 if (dump_enabled_p ())
611 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
612 " edge not inlinable: not in SSA form\n");
613 return false;
614 }
615 if (!can_inline_edge_p (e, true, true)
616 || !can_inline_edge_by_limits_p (e, true, false, true))
617 return false;
618 return true;
619 }
620
621
622 /* Return number of calls in N. Ignore cheap builtins. */
623
624 static int
625 num_calls (struct cgraph_node *n)
626 {
627 struct cgraph_edge *e;
628 int num = 0;
629
630 for (e = n->callees; e; e = e->next_callee)
631 if (!is_inexpensive_builtin (e->callee->decl))
632 num++;
633 return num;
634 }
635
636
637 /* Return true if we are interested in inlining small function. */
638
639 static bool
640 want_early_inline_function_p (struct cgraph_edge *e)
641 {
642 bool want_inline = true;
643 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
644
645 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
646 ;
647 /* For AutoFDO, we need to make sure that before profile summary, all
648 hot paths' IR look exactly the same as profiled binary. As a result,
649 in einliner, we will disregard size limit and inline those callsites
650 that are:
651 * inlined in the profiled binary, and
652 * the cloned callee has enough samples to be considered "hot". */
653 else if (flag_auto_profile && afdo_callsite_hot_enough_for_early_inline (e))
654 ;
655 else if (!DECL_DECLARED_INLINE_P (callee->decl)
656 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
657 {
658 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
659 report_inline_failed_reason (e);
660 want_inline = false;
661 }
662 else
663 {
664 int growth = estimate_edge_growth (e);
665 int n;
666 int early_inlining_insns = opt_for_fn (e->caller->decl, optimize) >= 3
667 ? PARAM_VALUE (PARAM_EARLY_INLINING_INSNS)
668 : PARAM_VALUE (PARAM_EARLY_INLINING_INSNS_O2);
669
670
671 if (growth <= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SIZE))
672 ;
673 else if (!e->maybe_hot_p ())
674 {
675 if (dump_enabled_p ())
676 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
677 " will not early inline: %C->%C, "
678 "call is cold and code would grow by %i\n",
679 e->caller, callee,
680 growth);
681 want_inline = false;
682 }
683 else if (growth > early_inlining_insns)
684 {
685 if (dump_enabled_p ())
686 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
687 " will not early inline: %C->%C, "
688 "growth %i exceeds --param early-inlining-insns%s\n",
689 e->caller, callee, growth,
690 opt_for_fn (e->caller->decl, optimize) >= 3
691 ? "" : "-O2");
692 want_inline = false;
693 }
694 else if ((n = num_calls (callee)) != 0
695 && growth * (n + 1) > early_inlining_insns)
696 {
697 if (dump_enabled_p ())
698 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
699 " will not early inline: %C->%C, "
700 "growth %i exceeds --param early-inlining-insns%s "
701 "divided by number of calls\n",
702 e->caller, callee, growth,
703 opt_for_fn (e->caller->decl, optimize) >= 3
704 ? "" : "-O2");
705 want_inline = false;
706 }
707 }
708 return want_inline;
709 }
710
711 /* Compute time of the edge->caller + edge->callee execution when inlining
712 does not happen. */
713
714 inline sreal
715 compute_uninlined_call_time (struct cgraph_edge *edge,
716 sreal uninlined_call_time)
717 {
718 cgraph_node *caller = (edge->caller->global.inlined_to
719 ? edge->caller->global.inlined_to
720 : edge->caller);
721
722 sreal freq = edge->sreal_frequency ();
723 if (freq > 0)
724 uninlined_call_time *= freq;
725 else
726 uninlined_call_time = uninlined_call_time >> 11;
727
728 sreal caller_time = ipa_fn_summaries->get (caller)->time;
729 return uninlined_call_time + caller_time;
730 }
731
732 /* Same as compute_uinlined_call_time but compute time when inlining
733 does happen. */
734
735 inline sreal
736 compute_inlined_call_time (struct cgraph_edge *edge,
737 sreal time)
738 {
739 cgraph_node *caller = (edge->caller->global.inlined_to
740 ? edge->caller->global.inlined_to
741 : edge->caller);
742 sreal caller_time = ipa_fn_summaries->get (caller)->time;
743
744 sreal freq = edge->sreal_frequency ();
745 if (freq > 0)
746 time *= freq;
747 else
748 time = time >> 11;
749
750 /* This calculation should match one in ipa-inline-analysis.c
751 (estimate_edge_size_and_time). */
752 time -= (sreal)ipa_call_summaries->get (edge)->call_stmt_time * freq;
753 time += caller_time;
754 if (time <= 0)
755 time = ((sreal) 1) >> 8;
756 gcc_checking_assert (time >= 0);
757 return time;
758 }
759
760 /* Return true if the speedup for inlining E is bigger than
761 PARAM_MAX_INLINE_MIN_SPEEDUP. */
762
763 static bool
764 big_speedup_p (struct cgraph_edge *e)
765 {
766 sreal unspec_time;
767 sreal spec_time = estimate_edge_time (e, &unspec_time);
768 sreal time = compute_uninlined_call_time (e, unspec_time);
769 sreal inlined_time = compute_inlined_call_time (e, spec_time);
770 cgraph_node *caller = e->caller->global.inlined_to
771 ? e->caller->global.inlined_to
772 : e->caller;
773 int limit = opt_for_fn (caller->decl, optimize) >= 3
774 ? PARAM_VALUE (PARAM_INLINE_MIN_SPEEDUP)
775 : PARAM_VALUE (PARAM_INLINE_MIN_SPEEDUP_O2);
776
777 if ((time - inlined_time) * 100 > time * limit)
778 return true;
779 return false;
780 }
781
782 /* Return true if we are interested in inlining small function.
783 When REPORT is true, report reason to dump file. */
784
785 static bool
786 want_inline_small_function_p (struct cgraph_edge *e, bool report)
787 {
788 bool want_inline = true;
789 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
790
791 /* Allow this function to be called before can_inline_edge_p,
792 since it's usually cheaper. */
793 if (cgraph_inline_failed_type (e->inline_failed) == CIF_FINAL_ERROR)
794 want_inline = false;
795 else if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
796 ;
797 else if (!DECL_DECLARED_INLINE_P (callee->decl)
798 && !opt_for_fn (e->caller->decl, flag_inline_small_functions))
799 {
800 e->inline_failed = CIF_FUNCTION_NOT_INLINE_CANDIDATE;
801 want_inline = false;
802 }
803 /* Do fast and conservative check if the function can be good
804 inline candidate. At the moment we allow inline hints to
805 promote non-inline functions to inline and we increase
806 MAX_INLINE_INSNS_SINGLE 16-fold for inline functions. */
807 else if ((!DECL_DECLARED_INLINE_P (callee->decl)
808 && (!e->count.ipa ().initialized_p () || !e->maybe_hot_p ()))
809 && ipa_fn_summaries->get (callee)->min_size
810 - ipa_call_summaries->get (e)->call_stmt_size
811 > MAX (inline_insns_single (e->caller),
812 inline_insns_auto (e->caller)))
813 {
814 if (opt_for_fn (e->caller->decl, optimize) >= 3)
815 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
816 else
817 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_O2_LIMIT;
818 want_inline = false;
819 }
820 else if ((DECL_DECLARED_INLINE_P (callee->decl)
821 || e->count.ipa ().nonzero_p ())
822 && ipa_fn_summaries->get (callee)->min_size
823 - ipa_call_summaries->get (e)->call_stmt_size
824 > 16 * inline_insns_single (e->caller))
825 {
826 if (opt_for_fn (e->caller->decl, optimize) >= 3)
827 e->inline_failed = (DECL_DECLARED_INLINE_P (callee->decl)
828 ? CIF_MAX_INLINE_INSNS_SINGLE_LIMIT
829 : CIF_MAX_INLINE_INSNS_AUTO_LIMIT);
830 else
831 e->inline_failed = (DECL_DECLARED_INLINE_P (callee->decl)
832 ? CIF_MAX_INLINE_INSNS_SINGLE_O2_LIMIT
833 : CIF_MAX_INLINE_INSNS_AUTO_O2_LIMIT);
834 want_inline = false;
835 }
836 else
837 {
838 int growth = estimate_edge_growth (e);
839 ipa_hints hints = estimate_edge_hints (e);
840 int big_speedup = -1; /* compute this lazily */
841
842 if (growth <= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SIZE))
843 ;
844 /* Apply MAX_INLINE_INSNS_SINGLE limit. Do not do so when
845 hints suggests that inlining given function is very profitable. */
846 else if (DECL_DECLARED_INLINE_P (callee->decl)
847 && growth >= inline_insns_single (e->caller)
848 && (growth >= inline_insns_single (e->caller) * 16
849 || (!(hints & (INLINE_HINT_indirect_call
850 | INLINE_HINT_known_hot
851 | INLINE_HINT_loop_iterations
852 | INLINE_HINT_loop_stride))
853 && !(big_speedup = big_speedup_p (e)))))
854 {
855 if (opt_for_fn (e->caller->decl, optimize) >= 3)
856 e->inline_failed = CIF_MAX_INLINE_INSNS_SINGLE_LIMIT;
857 else
858 e->inline_failed = CIF_MAX_INLINE_INSNS_SINGLE_O2_LIMIT;
859 want_inline = false;
860 }
861 else if (!DECL_DECLARED_INLINE_P (callee->decl)
862 && !opt_for_fn (e->caller->decl, flag_inline_functions)
863 && growth >= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_SMALL))
864 {
865 /* growth_likely_positive is expensive, always test it last. */
866 if (growth >= inline_insns_single (e->caller)
867 || growth_likely_positive (callee, growth))
868 {
869 e->inline_failed = CIF_NOT_DECLARED_INLINED;
870 want_inline = false;
871 }
872 }
873 /* Apply MAX_INLINE_INSNS_AUTO limit for functions not declared inline
874 Upgrade it to MAX_INLINE_INSNS_SINGLE when hints suggests that
875 inlining given function is very profitable. */
876 else if (!DECL_DECLARED_INLINE_P (callee->decl)
877 && !(hints & INLINE_HINT_known_hot)
878 && growth >= ((hints & (INLINE_HINT_indirect_call
879 | INLINE_HINT_loop_iterations
880 | INLINE_HINT_loop_stride))
881 ? MAX (inline_insns_auto (e->caller),
882 inline_insns_single (e->caller))
883 : inline_insns_auto (e->caller))
884 && !(big_speedup == -1 ? big_speedup_p (e) : big_speedup))
885 {
886 /* growth_likely_positive is expensive, always test it last. */
887 if (growth >= inline_insns_single (e->caller)
888 || growth_likely_positive (callee, growth))
889 {
890 if (opt_for_fn (e->caller->decl, optimize) >= 3)
891 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_LIMIT;
892 else
893 e->inline_failed = CIF_MAX_INLINE_INSNS_AUTO_O2_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)
900 || growth_likely_positive (callee, 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_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO);
932
933 if (DECL_DECLARED_INLINE_P (edge->caller->decl))
934 max_depth = PARAM_VALUE (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->global.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_VALUE (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->global.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 (estimate_growth (node) > 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->global.inlined_to
1089 ? edge->caller->global.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 <= callee_info->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 inlined_time = compute_inlined_call_time (edge, edge_time);
1152
1153 numerator = (compute_uninlined_call_time (edge, unspec_edge_time)
1154 - inlined_time);
1155 if (numerator <= 0)
1156 numerator = ((sreal) 1 >> 8);
1157 if (caller->count.ipa ().nonzero_p ())
1158 numerator *= caller->count.ipa ().to_gcov_type ();
1159 else if (caller->count.ipa ().initialized_p ())
1160 numerator = numerator >> 11;
1161 denominator = growth;
1162
1163 overall_growth = callee_info->growth;
1164
1165 /* Look for inliner wrappers of the form:
1166
1167 inline_caller ()
1168 {
1169 do_fast_job...
1170 if (need_more_work)
1171 noninline_callee ();
1172 }
1173 Withhout panilizing this case, we usually inline noninline_callee
1174 into the inline_caller because overall_growth is small preventing
1175 further inlining of inline_caller.
1176
1177 Penalize only callgraph edges to functions with small overall
1178 growth ...
1179 */
1180 if (growth > overall_growth
1181 /* ... and having only one caller which is not inlined ... */
1182 && callee_info->single_caller
1183 && !edge->caller->global.inlined_to
1184 /* ... and edges executed only conditionally ... */
1185 && edge->sreal_frequency () < 1
1186 /* ... consider case where callee is not inline but caller is ... */
1187 && ((!DECL_DECLARED_INLINE_P (edge->callee->decl)
1188 && DECL_DECLARED_INLINE_P (caller->decl))
1189 /* ... or when early optimizers decided to split and edge
1190 frequency still indicates splitting is a win ... */
1191 || (callee->split_part && !caller->split_part
1192 && edge->sreal_frequency () * 100
1193 < PARAM_VALUE
1194 (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 and. */
1204 if (!caller_info->single_caller && overall_growth < caller_growth
1205 && caller_info->inlinable
1206 && caller_info->size
1207 < (DECL_DECLARED_INLINE_P (caller->decl)
1208 ? inline_insns_single (caller) : inline_insns_auto (caller)))
1209 {
1210 if (dump)
1211 fprintf (dump_file,
1212 " Wrapper penalty. Increasing growth %i to %i\n",
1213 overall_growth, caller_growth);
1214 overall_growth = caller_growth;
1215 }
1216 }
1217 if (overall_growth > 0)
1218 {
1219 /* Strongly preffer functions with few callers that can be inlined
1220 fully. The square root here leads to smaller binaries at average.
1221 Watch however for extreme cases and return to linear function
1222 when growth is large. */
1223 if (overall_growth < 256)
1224 overall_growth *= overall_growth;
1225 else
1226 overall_growth += 256 * 256 - 256;
1227 denominator *= overall_growth;
1228 }
1229 denominator *= ipa_fn_summaries->get (caller)->self_size + growth;
1230
1231 badness = - numerator / denominator;
1232
1233 if (dump)
1234 {
1235 fprintf (dump_file,
1236 " %f: guessed profile. frequency %f, count %" PRId64
1237 " caller count %" PRId64
1238 " time w/o inlining %f, time with inlining %f"
1239 " overall growth %i (current) %i (original)"
1240 " %i (compensated)\n",
1241 badness.to_double (),
1242 edge->sreal_frequency ().to_double (),
1243 edge->count.ipa ().initialized_p () ? edge->count.ipa ().to_gcov_type () : -1,
1244 caller->count.ipa ().initialized_p () ? caller->count.ipa ().to_gcov_type () : -1,
1245 compute_uninlined_call_time (edge,
1246 unspec_edge_time).to_double (),
1247 inlined_time.to_double (),
1248 estimate_growth (callee),
1249 callee_info->growth, overall_growth);
1250 }
1251 }
1252 /* When function local profile is not available or it does not give
1253 useful information (ie frequency is zero), base the cost on
1254 loop nest and overall size growth, so we optimize for overall number
1255 of functions fully inlined in program. */
1256 else
1257 {
1258 int nest = MIN (ipa_call_summaries->get (edge)->loop_depth, 8);
1259 badness = growth;
1260
1261 /* Decrease badness if call is nested. */
1262 if (badness > 0)
1263 badness = badness >> nest;
1264 else
1265 badness = badness << nest;
1266 if (dump)
1267 fprintf (dump_file, " %f: no profile. nest %i\n",
1268 badness.to_double (), nest);
1269 }
1270 gcc_checking_assert (badness != 0);
1271
1272 if (edge->recursive_p ())
1273 badness = badness.shift (badness > 0 ? 4 : -4);
1274 if ((hints & (INLINE_HINT_indirect_call
1275 | INLINE_HINT_loop_iterations
1276 | INLINE_HINT_loop_stride))
1277 || callee_info->growth <= 0)
1278 badness = badness.shift (badness > 0 ? -2 : 2);
1279 if (hints & (INLINE_HINT_same_scc))
1280 badness = badness.shift (badness > 0 ? 3 : -3);
1281 else if (hints & (INLINE_HINT_in_scc))
1282 badness = badness.shift (badness > 0 ? 2 : -2);
1283 else if (hints & (INLINE_HINT_cross_module))
1284 badness = badness.shift (badness > 0 ? 1 : -1);
1285 if (DECL_DISREGARD_INLINE_LIMITS (callee->decl))
1286 badness = badness.shift (badness > 0 ? -4 : 4);
1287 else if ((hints & INLINE_HINT_declared_inline))
1288 badness = badness.shift (badness > 0 ? -3 : 3);
1289 if (dump)
1290 fprintf (dump_file, " Adjusted by hints %f\n", badness.to_double ());
1291 return badness;
1292 }
1293
1294 /* Recompute badness of EDGE and update its key in HEAP if needed. */
1295 static inline void
1296 update_edge_key (edge_heap_t *heap, struct cgraph_edge *edge)
1297 {
1298 sreal badness = edge_badness (edge, false);
1299 if (edge->aux)
1300 {
1301 edge_heap_node_t *n = (edge_heap_node_t *) edge->aux;
1302 gcc_checking_assert (n->get_data () == edge);
1303
1304 /* fibonacci_heap::replace_key does busy updating of the
1305 heap that is unnecesarily expensive.
1306 We do lazy increases: after extracting minimum if the key
1307 turns out to be out of date, it is re-inserted into heap
1308 with correct value. */
1309 if (badness < n->get_key ())
1310 {
1311 if (dump_file && (dump_flags & TDF_DETAILS))
1312 {
1313 fprintf (dump_file,
1314 " decreasing badness %s -> %s, %f to %f\n",
1315 edge->caller->dump_name (),
1316 edge->callee->dump_name (),
1317 n->get_key ().to_double (),
1318 badness.to_double ());
1319 }
1320 heap->decrease_key (n, badness);
1321 }
1322 }
1323 else
1324 {
1325 if (dump_file && (dump_flags & TDF_DETAILS))
1326 {
1327 fprintf (dump_file,
1328 " enqueuing call %s -> %s, badness %f\n",
1329 edge->caller->dump_name (),
1330 edge->callee->dump_name (),
1331 badness.to_double ());
1332 }
1333 edge->aux = heap->insert (badness, edge);
1334 }
1335 }
1336
1337
1338 /* NODE was inlined.
1339 All caller edges needs to be resetted because
1340 size estimates change. Similarly callees needs reset
1341 because better context may be known. */
1342
1343 static void
1344 reset_edge_caches (struct cgraph_node *node)
1345 {
1346 struct cgraph_edge *edge;
1347 struct cgraph_edge *e = node->callees;
1348 struct cgraph_node *where = node;
1349 struct ipa_ref *ref;
1350
1351 if (where->global.inlined_to)
1352 where = where->global.inlined_to;
1353
1354 if (edge_growth_cache != NULL)
1355 for (edge = where->callers; edge; edge = edge->next_caller)
1356 if (edge->inline_failed)
1357 edge_growth_cache->remove (edge);
1358
1359 FOR_EACH_ALIAS (where, ref)
1360 reset_edge_caches (dyn_cast <cgraph_node *> (ref->referring));
1361
1362 if (!e)
1363 return;
1364
1365 while (true)
1366 if (!e->inline_failed && e->callee->callees)
1367 e = e->callee->callees;
1368 else
1369 {
1370 if (edge_growth_cache != NULL && e->inline_failed)
1371 edge_growth_cache->remove (e);
1372 if (e->next_callee)
1373 e = e->next_callee;
1374 else
1375 {
1376 do
1377 {
1378 if (e->caller == node)
1379 return;
1380 e = e->caller->callers;
1381 }
1382 while (!e->next_callee);
1383 e = e->next_callee;
1384 }
1385 }
1386 }
1387
1388 /* Recompute HEAP nodes for each of caller of NODE.
1389 UPDATED_NODES track nodes we already visited, to avoid redundant work.
1390 When CHECK_INLINABLITY_FOR is set, re-check for specified edge that
1391 it is inlinable. Otherwise check all edges. */
1392
1393 static void
1394 update_caller_keys (edge_heap_t *heap, struct cgraph_node *node,
1395 bitmap updated_nodes,
1396 struct cgraph_edge *check_inlinablity_for)
1397 {
1398 struct cgraph_edge *edge;
1399 struct ipa_ref *ref;
1400
1401 if ((!node->alias && !ipa_fn_summaries->get (node)->inlinable)
1402 || node->global.inlined_to)
1403 return;
1404 if (!bitmap_set_bit (updated_nodes, node->get_uid ()))
1405 return;
1406
1407 FOR_EACH_ALIAS (node, ref)
1408 {
1409 struct cgraph_node *alias = dyn_cast <cgraph_node *> (ref->referring);
1410 update_caller_keys (heap, alias, updated_nodes, check_inlinablity_for);
1411 }
1412
1413 for (edge = node->callers; edge; edge = edge->next_caller)
1414 if (edge->inline_failed)
1415 {
1416 if (!check_inlinablity_for
1417 || check_inlinablity_for == edge)
1418 {
1419 if (can_inline_edge_p (edge, false)
1420 && want_inline_small_function_p (edge, false)
1421 && can_inline_edge_by_limits_p (edge, false))
1422 update_edge_key (heap, edge);
1423 else if (edge->aux)
1424 {
1425 report_inline_failed_reason (edge);
1426 heap->delete_node ((edge_heap_node_t *) edge->aux);
1427 edge->aux = NULL;
1428 }
1429 }
1430 else if (edge->aux)
1431 update_edge_key (heap, edge);
1432 }
1433 }
1434
1435 /* Recompute HEAP nodes for each uninlined call in NODE.
1436 This is used when we know that edge badnesses are going only to increase
1437 (we introduced new call site) and thus all we need is to insert newly
1438 created edges into heap. */
1439
1440 static void
1441 update_callee_keys (edge_heap_t *heap, struct cgraph_node *node,
1442 bitmap updated_nodes)
1443 {
1444 struct cgraph_edge *e = node->callees;
1445
1446 if (!e)
1447 return;
1448 while (true)
1449 if (!e->inline_failed && e->callee->callees)
1450 e = e->callee->callees;
1451 else
1452 {
1453 enum availability avail;
1454 struct cgraph_node *callee;
1455 /* We do not reset callee growth cache here. Since we added a new call,
1456 growth chould have just increased and consequentely badness metric
1457 don't need updating. */
1458 if (e->inline_failed
1459 && (callee = e->callee->ultimate_alias_target (&avail, e->caller))
1460 && ipa_fn_summaries->get (callee) != NULL
1461 && ipa_fn_summaries->get (callee)->inlinable
1462 && avail >= AVAIL_AVAILABLE
1463 && !bitmap_bit_p (updated_nodes, callee->get_uid ()))
1464 {
1465 if (can_inline_edge_p (e, false)
1466 && want_inline_small_function_p (e, false)
1467 && can_inline_edge_by_limits_p (e, false))
1468 update_edge_key (heap, e);
1469 else if (e->aux)
1470 {
1471 report_inline_failed_reason (e);
1472 heap->delete_node ((edge_heap_node_t *) e->aux);
1473 e->aux = NULL;
1474 }
1475 }
1476 if (e->next_callee)
1477 e = e->next_callee;
1478 else
1479 {
1480 do
1481 {
1482 if (e->caller == node)
1483 return;
1484 e = e->caller->callers;
1485 }
1486 while (!e->next_callee);
1487 e = e->next_callee;
1488 }
1489 }
1490 }
1491
1492 /* Enqueue all recursive calls from NODE into priority queue depending on
1493 how likely we want to recursively inline the call. */
1494
1495 static void
1496 lookup_recursive_calls (struct cgraph_node *node, struct cgraph_node *where,
1497 edge_heap_t *heap)
1498 {
1499 struct cgraph_edge *e;
1500 enum availability avail;
1501
1502 for (e = where->callees; e; e = e->next_callee)
1503 if (e->callee == node
1504 || (e->callee->ultimate_alias_target (&avail, e->caller) == node
1505 && avail > AVAIL_INTERPOSABLE))
1506 heap->insert (-e->sreal_frequency (), e);
1507 for (e = where->callees; e; e = e->next_callee)
1508 if (!e->inline_failed)
1509 lookup_recursive_calls (node, e->callee, heap);
1510 }
1511
1512 /* Decide on recursive inlining: in the case function has recursive calls,
1513 inline until body size reaches given argument. If any new indirect edges
1514 are discovered in the process, add them to *NEW_EDGES, unless NEW_EDGES
1515 is NULL. */
1516
1517 static bool
1518 recursive_inlining (struct cgraph_edge *edge,
1519 vec<cgraph_edge *> *new_edges)
1520 {
1521 int limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO);
1522 edge_heap_t heap (sreal::min ());
1523 struct cgraph_node *node;
1524 struct cgraph_edge *e;
1525 struct cgraph_node *master_clone = NULL, *next;
1526 int depth = 0;
1527 int n = 0;
1528
1529 node = edge->caller;
1530 if (node->global.inlined_to)
1531 node = node->global.inlined_to;
1532
1533 if (DECL_DECLARED_INLINE_P (node->decl))
1534 limit = PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE);
1535
1536 /* Make sure that function is small enough to be considered for inlining. */
1537 if (estimate_size_after_inlining (node, edge) >= limit)
1538 return false;
1539 lookup_recursive_calls (node, node, &heap);
1540 if (heap.empty ())
1541 return false;
1542
1543 if (dump_file)
1544 fprintf (dump_file,
1545 " Performing recursive inlining on %s\n",
1546 node->name ());
1547
1548 /* Do the inlining and update list of recursive call during process. */
1549 while (!heap.empty ())
1550 {
1551 struct cgraph_edge *curr = heap.extract_min ();
1552 struct cgraph_node *cnode, *dest = curr->callee;
1553
1554 if (!can_inline_edge_p (curr, true)
1555 || !can_inline_edge_by_limits_p (curr, true))
1556 continue;
1557
1558 /* MASTER_CLONE is produced in the case we already started modified
1559 the function. Be sure to redirect edge to the original body before
1560 estimating growths otherwise we will be seeing growths after inlining
1561 the already modified body. */
1562 if (master_clone)
1563 {
1564 curr->redirect_callee (master_clone);
1565 if (edge_growth_cache != NULL)
1566 edge_growth_cache->remove (curr);
1567 }
1568
1569 if (estimate_size_after_inlining (node, curr) > limit)
1570 {
1571 curr->redirect_callee (dest);
1572 if (edge_growth_cache != NULL)
1573 edge_growth_cache->remove (curr);
1574 break;
1575 }
1576
1577 depth = 1;
1578 for (cnode = curr->caller;
1579 cnode->global.inlined_to; cnode = cnode->callers->caller)
1580 if (node->decl
1581 == curr->callee->ultimate_alias_target ()->decl)
1582 depth++;
1583
1584 if (!want_inline_self_recursive_call_p (curr, node, false, depth))
1585 {
1586 curr->redirect_callee (dest);
1587 if (edge_growth_cache != NULL)
1588 edge_growth_cache->remove (curr);
1589 continue;
1590 }
1591
1592 if (dump_file)
1593 {
1594 fprintf (dump_file,
1595 " Inlining call of depth %i", depth);
1596 if (node->count.nonzero_p ())
1597 {
1598 fprintf (dump_file, " called approx. %.2f times per call",
1599 (double)curr->count.to_gcov_type ()
1600 / node->count.to_gcov_type ());
1601 }
1602 fprintf (dump_file, "\n");
1603 }
1604 if (!master_clone)
1605 {
1606 /* We need original clone to copy around. */
1607 master_clone = node->create_clone (node->decl, node->count,
1608 false, vNULL, true, NULL, NULL);
1609 for (e = master_clone->callees; e; e = e->next_callee)
1610 if (!e->inline_failed)
1611 clone_inlined_nodes (e, true, false, NULL);
1612 curr->redirect_callee (master_clone);
1613 if (edge_growth_cache != NULL)
1614 edge_growth_cache->remove (curr);
1615 }
1616
1617 inline_call (curr, false, new_edges, &overall_size, true);
1618 lookup_recursive_calls (node, curr->callee, &heap);
1619 n++;
1620 }
1621
1622 if (!heap.empty () && dump_file)
1623 fprintf (dump_file, " Recursive inlining growth limit met.\n");
1624
1625 if (!master_clone)
1626 return false;
1627
1628 if (dump_enabled_p ())
1629 dump_printf_loc (MSG_NOTE, edge->call_stmt,
1630 "\n Inlined %i times, "
1631 "body grown from size %i to %i, time %f to %f\n", n,
1632 ipa_fn_summaries->get (master_clone)->size,
1633 ipa_fn_summaries->get (node)->size,
1634 ipa_fn_summaries->get (master_clone)->time.to_double (),
1635 ipa_fn_summaries->get (node)->time.to_double ());
1636
1637 /* Remove master clone we used for inlining. We rely that clones inlined
1638 into master clone gets queued just before master clone so we don't
1639 need recursion. */
1640 for (node = symtab->first_function (); node != master_clone;
1641 node = next)
1642 {
1643 next = symtab->next_function (node);
1644 if (node->global.inlined_to == master_clone)
1645 node->remove ();
1646 }
1647 master_clone->remove ();
1648 return true;
1649 }
1650
1651
1652 /* Given whole compilation unit estimate of INSNS, compute how large we can
1653 allow the unit to grow. */
1654
1655 static int
1656 compute_max_insns (int insns)
1657 {
1658 int max_insns = insns;
1659 if (max_insns < PARAM_VALUE (PARAM_LARGE_UNIT_INSNS))
1660 max_insns = PARAM_VALUE (PARAM_LARGE_UNIT_INSNS);
1661
1662 return ((int64_t) max_insns
1663 * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH)) / 100);
1664 }
1665
1666
1667 /* Compute badness of all edges in NEW_EDGES and add them to the HEAP. */
1668
1669 static void
1670 add_new_edges_to_heap (edge_heap_t *heap, vec<cgraph_edge *> new_edges)
1671 {
1672 while (new_edges.length () > 0)
1673 {
1674 struct cgraph_edge *edge = new_edges.pop ();
1675
1676 gcc_assert (!edge->aux);
1677 gcc_assert (edge->callee);
1678 if (edge->inline_failed
1679 && can_inline_edge_p (edge, true)
1680 && want_inline_small_function_p (edge, true)
1681 && can_inline_edge_by_limits_p (edge, true))
1682 edge->aux = heap->insert (edge_badness (edge, false), edge);
1683 }
1684 }
1685
1686 /* Remove EDGE from the fibheap. */
1687
1688 static void
1689 heap_edge_removal_hook (struct cgraph_edge *e, void *data)
1690 {
1691 if (e->aux)
1692 {
1693 ((edge_heap_t *)data)->delete_node ((edge_heap_node_t *)e->aux);
1694 e->aux = NULL;
1695 }
1696 }
1697
1698 /* Return true if speculation of edge E seems useful.
1699 If ANTICIPATE_INLINING is true, be conservative and hope that E
1700 may get inlined. */
1701
1702 bool
1703 speculation_useful_p (struct cgraph_edge *e, bool anticipate_inlining)
1704 {
1705 /* If we have already decided to inline the edge, it seems useful. */
1706 if (!e->inline_failed)
1707 return true;
1708
1709 enum availability avail;
1710 struct cgraph_node *target = e->callee->ultimate_alias_target (&avail,
1711 e->caller);
1712 struct cgraph_edge *direct, *indirect;
1713 struct ipa_ref *ref;
1714
1715 gcc_assert (e->speculative && !e->indirect_unknown_callee);
1716
1717 if (!e->maybe_hot_p ())
1718 return false;
1719
1720 /* See if IP optimizations found something potentially useful about the
1721 function. For now we look only for CONST/PURE flags. Almost everything
1722 else we propagate is useless. */
1723 if (avail >= AVAIL_AVAILABLE)
1724 {
1725 int ecf_flags = flags_from_decl_or_type (target->decl);
1726 if (ecf_flags & ECF_CONST)
1727 {
1728 e->speculative_call_info (direct, indirect, ref);
1729 if (!(indirect->indirect_info->ecf_flags & ECF_CONST))
1730 return true;
1731 }
1732 else if (ecf_flags & ECF_PURE)
1733 {
1734 e->speculative_call_info (direct, indirect, ref);
1735 if (!(indirect->indirect_info->ecf_flags & ECF_PURE))
1736 return true;
1737 }
1738 }
1739 /* If we did not managed to inline the function nor redirect
1740 to an ipa-cp clone (that are seen by having local flag set),
1741 it is probably pointless to inline it unless hardware is missing
1742 indirect call predictor. */
1743 if (!anticipate_inlining && !target->local.local)
1744 return false;
1745 /* For overwritable targets there is not much to do. */
1746 if (!can_inline_edge_p (e, false)
1747 || !can_inline_edge_by_limits_p (e, false, true))
1748 return false;
1749 /* OK, speculation seems interesting. */
1750 return true;
1751 }
1752
1753 /* We know that EDGE is not going to be inlined.
1754 See if we can remove speculation. */
1755
1756 static void
1757 resolve_noninline_speculation (edge_heap_t *edge_heap, struct cgraph_edge *edge)
1758 {
1759 if (edge->speculative && !speculation_useful_p (edge, false))
1760 {
1761 struct cgraph_node *node = edge->caller;
1762 struct cgraph_node *where = node->global.inlined_to
1763 ? node->global.inlined_to : node;
1764 auto_bitmap updated_nodes;
1765
1766 if (edge->count.ipa ().initialized_p ())
1767 spec_rem += edge->count.ipa ();
1768 edge->resolve_speculation ();
1769 reset_edge_caches (where);
1770 ipa_update_overall_fn_summary (where);
1771 update_caller_keys (edge_heap, where,
1772 updated_nodes, NULL);
1773 update_callee_keys (edge_heap, where,
1774 updated_nodes);
1775 }
1776 }
1777
1778 /* Return true if NODE should be accounted for overall size estimate.
1779 Skip all nodes optimized for size so we can measure the growth of hot
1780 part of program no matter of the padding. */
1781
1782 bool
1783 inline_account_function_p (struct cgraph_node *node)
1784 {
1785 return (!DECL_EXTERNAL (node->decl)
1786 && !opt_for_fn (node->decl, optimize_size)
1787 && node->frequency != NODE_FREQUENCY_UNLIKELY_EXECUTED);
1788 }
1789
1790 /* Count number of callers of NODE and store it into DATA (that
1791 points to int. Worker for cgraph_for_node_and_aliases. */
1792
1793 static bool
1794 sum_callers (struct cgraph_node *node, void *data)
1795 {
1796 struct cgraph_edge *e;
1797 int *num_calls = (int *)data;
1798
1799 for (e = node->callers; e; e = e->next_caller)
1800 (*num_calls)++;
1801 return false;
1802 }
1803
1804 /* We only propagate across edges with non-interposable callee. */
1805
1806 inline bool
1807 ignore_edge_p (struct cgraph_edge *e)
1808 {
1809 enum availability avail;
1810 e->callee->function_or_virtual_thunk_symbol (&avail, e->caller);
1811 return (avail <= AVAIL_INTERPOSABLE);
1812 }
1813
1814 /* We use greedy algorithm for inlining of small functions:
1815 All inline candidates are put into prioritized heap ordered in
1816 increasing badness.
1817
1818 The inlining of small functions is bounded by unit growth parameters. */
1819
1820 static void
1821 inline_small_functions (void)
1822 {
1823 struct cgraph_node *node;
1824 struct cgraph_edge *edge;
1825 edge_heap_t edge_heap (sreal::min ());
1826 auto_bitmap updated_nodes;
1827 int min_size, max_size;
1828 auto_vec<cgraph_edge *> new_indirect_edges;
1829 int initial_size = 0;
1830 struct cgraph_node **order = XCNEWVEC (cgraph_node *, symtab->cgraph_count);
1831 struct cgraph_edge_hook_list *edge_removal_hook_holder;
1832 new_indirect_edges.create (8);
1833
1834 edge_removal_hook_holder
1835 = symtab->add_edge_removal_hook (&heap_edge_removal_hook, &edge_heap);
1836
1837 /* Compute overall unit size and other global parameters used by badness
1838 metrics. */
1839
1840 max_count = profile_count::uninitialized ();
1841 ipa_reduced_postorder (order, true, ignore_edge_p);
1842 free (order);
1843
1844 FOR_EACH_DEFINED_FUNCTION (node)
1845 if (!node->global.inlined_to)
1846 {
1847 if (!node->alias && node->analyzed
1848 && (node->has_gimple_body_p () || node->thunk.thunk_p)
1849 && opt_for_fn (node->decl, optimize))
1850 {
1851 class ipa_fn_summary *info = ipa_fn_summaries->get (node);
1852 struct ipa_dfs_info *dfs = (struct ipa_dfs_info *) node->aux;
1853
1854 /* Do not account external functions, they will be optimized out
1855 if not inlined. Also only count the non-cold portion of program. */
1856 if (inline_account_function_p (node))
1857 initial_size += info->size;
1858 info->growth = estimate_growth (node);
1859
1860 int num_calls = 0;
1861 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
1862 true);
1863 if (num_calls == 1)
1864 info->single_caller = true;
1865 if (dfs && dfs->next_cycle)
1866 {
1867 struct cgraph_node *n2;
1868 int id = dfs->scc_no + 1;
1869 for (n2 = node; n2;
1870 n2 = ((struct ipa_dfs_info *) n2->aux)->next_cycle)
1871 if (opt_for_fn (n2->decl, optimize))
1872 {
1873 ipa_fn_summary *info2 = ipa_fn_summaries->get (n2);
1874 if (info2->scc_no)
1875 break;
1876 info2->scc_no = id;
1877 }
1878 }
1879 }
1880
1881 for (edge = node->callers; edge; edge = edge->next_caller)
1882 max_count = max_count.max (edge->count.ipa ());
1883 }
1884 ipa_free_postorder_info ();
1885 edge_growth_cache
1886 = new call_summary<edge_growth_cache_entry *> (symtab, false);
1887
1888 if (dump_file)
1889 fprintf (dump_file,
1890 "\nDeciding on inlining of small functions. Starting with size %i.\n",
1891 initial_size);
1892
1893 overall_size = initial_size;
1894 max_size = compute_max_insns (overall_size);
1895 min_size = overall_size;
1896
1897 /* Populate the heap with all edges we might inline. */
1898
1899 FOR_EACH_DEFINED_FUNCTION (node)
1900 {
1901 bool update = false;
1902 struct cgraph_edge *next = NULL;
1903 bool has_speculative = false;
1904
1905 if (!opt_for_fn (node->decl, optimize))
1906 continue;
1907
1908 if (dump_file)
1909 fprintf (dump_file, "Enqueueing calls in %s.\n", node->dump_name ());
1910
1911 for (edge = node->callees; edge; edge = next)
1912 {
1913 next = edge->next_callee;
1914 if (edge->inline_failed
1915 && !edge->aux
1916 && can_inline_edge_p (edge, true)
1917 && want_inline_small_function_p (edge, true)
1918 && can_inline_edge_by_limits_p (edge, true)
1919 && edge->inline_failed)
1920 {
1921 gcc_assert (!edge->aux);
1922 update_edge_key (&edge_heap, edge);
1923 }
1924 if (edge->speculative)
1925 has_speculative = true;
1926 }
1927 if (has_speculative)
1928 for (edge = node->callees; edge; edge = next)
1929 if (edge->speculative && !speculation_useful_p (edge,
1930 edge->aux != NULL))
1931 {
1932 edge->resolve_speculation ();
1933 update = true;
1934 }
1935 if (update)
1936 {
1937 struct cgraph_node *where = node->global.inlined_to
1938 ? node->global.inlined_to : node;
1939 ipa_update_overall_fn_summary (where);
1940 reset_edge_caches (where);
1941 update_caller_keys (&edge_heap, where,
1942 updated_nodes, NULL);
1943 update_callee_keys (&edge_heap, where,
1944 updated_nodes);
1945 bitmap_clear (updated_nodes);
1946 }
1947 }
1948
1949 gcc_assert (in_lto_p
1950 || !(max_count > 0)
1951 || (profile_info && flag_branch_probabilities));
1952
1953 while (!edge_heap.empty ())
1954 {
1955 int old_size = overall_size;
1956 struct cgraph_node *where, *callee;
1957 sreal badness = edge_heap.min_key ();
1958 sreal current_badness;
1959 int growth;
1960
1961 edge = edge_heap.extract_min ();
1962 gcc_assert (edge->aux);
1963 edge->aux = NULL;
1964 if (!edge->inline_failed || !edge->callee->analyzed)
1965 continue;
1966
1967 #if CHECKING_P
1968 /* Be sure that caches are maintained consistent.
1969 This check is affected by scaling roundoff errors when compiling for
1970 IPA this we skip it in that case. */
1971 if (!edge->callee->count.ipa_p ()
1972 && (!max_count.initialized_p () || !max_count.nonzero_p ()))
1973 {
1974 sreal cached_badness = edge_badness (edge, false);
1975
1976 int old_size_est = estimate_edge_size (edge);
1977 sreal old_time_est = estimate_edge_time (edge);
1978 int old_hints_est = estimate_edge_hints (edge);
1979
1980 if (edge_growth_cache != NULL)
1981 edge_growth_cache->remove (edge);
1982 gcc_assert (old_size_est == estimate_edge_size (edge));
1983 gcc_assert (old_time_est == estimate_edge_time (edge));
1984 /* FIXME:
1985
1986 gcc_assert (old_hints_est == estimate_edge_hints (edge));
1987
1988 fails with profile feedback because some hints depends on
1989 maybe_hot_edge_p predicate and because callee gets inlined to other
1990 calls, the edge may become cold.
1991 This ought to be fixed by computing relative probabilities
1992 for given invocation but that will be better done once whole
1993 code is converted to sreals. Disable for now and revert to "wrong"
1994 value so enable/disable checking paths agree. */
1995 edge_growth_cache->get (edge)->hints = old_hints_est + 1;
1996
1997 /* When updating the edge costs, we only decrease badness in the keys.
1998 Increases of badness are handled lazilly; when we see key with out
1999 of date value on it, we re-insert it now. */
2000 current_badness = edge_badness (edge, false);
2001 gcc_assert (cached_badness == current_badness);
2002 gcc_assert (current_badness >= badness);
2003 }
2004 else
2005 current_badness = edge_badness (edge, false);
2006 #else
2007 current_badness = edge_badness (edge, false);
2008 #endif
2009 if (current_badness != badness)
2010 {
2011 if (edge_heap.min () && current_badness > edge_heap.min_key ())
2012 {
2013 edge->aux = edge_heap.insert (current_badness, edge);
2014 continue;
2015 }
2016 else
2017 badness = current_badness;
2018 }
2019
2020 if (!can_inline_edge_p (edge, true)
2021 || !can_inline_edge_by_limits_p (edge, true))
2022 {
2023 resolve_noninline_speculation (&edge_heap, edge);
2024 continue;
2025 }
2026
2027 callee = edge->callee->ultimate_alias_target ();
2028 growth = estimate_edge_growth (edge);
2029 if (dump_file)
2030 {
2031 fprintf (dump_file,
2032 "\nConsidering %s with %i size\n",
2033 callee->dump_name (),
2034 ipa_fn_summaries->get (callee)->size);
2035 fprintf (dump_file,
2036 " to be inlined into %s in %s:%i\n"
2037 " Estimated badness is %f, frequency %.2f.\n",
2038 edge->caller->dump_name (),
2039 edge->call_stmt
2040 && (LOCATION_LOCUS (gimple_location ((const gimple *)
2041 edge->call_stmt))
2042 > BUILTINS_LOCATION)
2043 ? gimple_filename ((const gimple *) edge->call_stmt)
2044 : "unknown",
2045 edge->call_stmt
2046 ? gimple_lineno ((const gimple *) edge->call_stmt)
2047 : -1,
2048 badness.to_double (),
2049 edge->sreal_frequency ().to_double ());
2050 if (edge->count.ipa ().initialized_p ())
2051 {
2052 fprintf (dump_file, " Called ");
2053 edge->count.ipa ().dump (dump_file);
2054 fprintf (dump_file, " times\n");
2055 }
2056 if (dump_flags & TDF_DETAILS)
2057 edge_badness (edge, true);
2058 }
2059
2060 if (overall_size + growth > max_size
2061 && !DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2062 {
2063 edge->inline_failed = CIF_INLINE_UNIT_GROWTH_LIMIT;
2064 report_inline_failed_reason (edge);
2065 resolve_noninline_speculation (&edge_heap, edge);
2066 continue;
2067 }
2068
2069 if (!want_inline_small_function_p (edge, true))
2070 {
2071 resolve_noninline_speculation (&edge_heap, edge);
2072 continue;
2073 }
2074
2075 /* Heuristics for inlining small functions work poorly for
2076 recursive calls where we do effects similar to loop unrolling.
2077 When inlining such edge seems profitable, leave decision on
2078 specific inliner. */
2079 if (edge->recursive_p ())
2080 {
2081 where = edge->caller;
2082 if (where->global.inlined_to)
2083 where = where->global.inlined_to;
2084 if (!recursive_inlining (edge,
2085 opt_for_fn (edge->caller->decl,
2086 flag_indirect_inlining)
2087 ? &new_indirect_edges : NULL))
2088 {
2089 edge->inline_failed = CIF_RECURSIVE_INLINING;
2090 resolve_noninline_speculation (&edge_heap, edge);
2091 continue;
2092 }
2093 reset_edge_caches (where);
2094 /* Recursive inliner inlines all recursive calls of the function
2095 at once. Consequently we need to update all callee keys. */
2096 if (opt_for_fn (edge->caller->decl, flag_indirect_inlining))
2097 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2098 update_callee_keys (&edge_heap, where, updated_nodes);
2099 bitmap_clear (updated_nodes);
2100 }
2101 else
2102 {
2103 struct cgraph_node *outer_node = NULL;
2104 int depth = 0;
2105
2106 /* Consider the case where self recursive function A is inlined
2107 into B. This is desired optimization in some cases, since it
2108 leads to effect similar of loop peeling and we might completely
2109 optimize out the recursive call. However we must be extra
2110 selective. */
2111
2112 where = edge->caller;
2113 while (where->global.inlined_to)
2114 {
2115 if (where->decl == callee->decl)
2116 outer_node = where, depth++;
2117 where = where->callers->caller;
2118 }
2119 if (outer_node
2120 && !want_inline_self_recursive_call_p (edge, outer_node,
2121 true, depth))
2122 {
2123 edge->inline_failed
2124 = (DECL_DISREGARD_INLINE_LIMITS (edge->callee->decl)
2125 ? CIF_RECURSIVE_INLINING : CIF_UNSPECIFIED);
2126 resolve_noninline_speculation (&edge_heap, edge);
2127 continue;
2128 }
2129 else if (depth && dump_file)
2130 fprintf (dump_file, " Peeling recursion with depth %i\n", depth);
2131
2132 gcc_checking_assert (!callee->global.inlined_to);
2133 inline_call (edge, true, &new_indirect_edges, &overall_size, true);
2134 add_new_edges_to_heap (&edge_heap, new_indirect_edges);
2135
2136 reset_edge_caches (edge->callee);
2137
2138 update_callee_keys (&edge_heap, where, updated_nodes);
2139 }
2140 where = edge->caller;
2141 if (where->global.inlined_to)
2142 where = where->global.inlined_to;
2143
2144 /* Our profitability metric can depend on local properties
2145 such as number of inlinable calls and size of the function body.
2146 After inlining these properties might change for the function we
2147 inlined into (since it's body size changed) and for the functions
2148 called by function we inlined (since number of it inlinable callers
2149 might change). */
2150 update_caller_keys (&edge_heap, where, updated_nodes, NULL);
2151 /* Offline copy count has possibly changed, recompute if profile is
2152 available. */
2153 struct cgraph_node *n = cgraph_node::get (edge->callee->decl);
2154 if (n != edge->callee && n->analyzed && n->count.ipa ().initialized_p ())
2155 update_callee_keys (&edge_heap, n, updated_nodes);
2156 bitmap_clear (updated_nodes);
2157
2158 if (dump_enabled_p ())
2159 {
2160 ipa_fn_summary *s = ipa_fn_summaries->get (edge->caller);
2161
2162 /* dump_printf can't handle %+i. */
2163 char buf_net_change[100];
2164 snprintf (buf_net_change, sizeof buf_net_change, "%+i",
2165 overall_size - old_size);
2166
2167 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, edge->call_stmt,
2168 " Inlined %C into %C which now has time %f and "
2169 "size %i, net change of %s.\n",
2170 edge->callee, edge->caller,
2171 s->time.to_double (), s->size, buf_net_change);
2172 }
2173 if (min_size > overall_size)
2174 {
2175 min_size = overall_size;
2176 max_size = compute_max_insns (min_size);
2177
2178 if (dump_file)
2179 fprintf (dump_file, "New minimal size reached: %i\n", min_size);
2180 }
2181 }
2182
2183 free_growth_caches ();
2184 if (dump_enabled_p ())
2185 dump_printf (MSG_NOTE,
2186 "Unit growth for small function inlining: %i->%i (%i%%)\n",
2187 initial_size, overall_size,
2188 initial_size ? overall_size * 100 / (initial_size) - 100: 0);
2189 symtab->remove_edge_removal_hook (edge_removal_hook_holder);
2190 }
2191
2192 /* Flatten NODE. Performed both during early inlining and
2193 at IPA inlining time. */
2194
2195 static void
2196 flatten_function (struct cgraph_node *node, bool early, bool update)
2197 {
2198 struct cgraph_edge *e;
2199
2200 /* We shouldn't be called recursively when we are being processed. */
2201 gcc_assert (node->aux == NULL);
2202
2203 node->aux = (void *) node;
2204
2205 for (e = node->callees; e; e = e->next_callee)
2206 {
2207 struct cgraph_node *orig_callee;
2208 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2209
2210 /* We've hit cycle? It is time to give up. */
2211 if (callee->aux)
2212 {
2213 if (dump_enabled_p ())
2214 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2215 "Not inlining %C into %C to avoid cycle.\n",
2216 callee, e->caller);
2217 if (cgraph_inline_failed_type (e->inline_failed) != CIF_FINAL_ERROR)
2218 e->inline_failed = CIF_RECURSIVE_INLINING;
2219 continue;
2220 }
2221
2222 /* When the edge is already inlined, we just need to recurse into
2223 it in order to fully flatten the leaves. */
2224 if (!e->inline_failed)
2225 {
2226 flatten_function (callee, early, false);
2227 continue;
2228 }
2229
2230 /* Flatten attribute needs to be processed during late inlining. For
2231 extra code quality we however do flattening during early optimization,
2232 too. */
2233 if (!early
2234 ? !can_inline_edge_p (e, true)
2235 && !can_inline_edge_by_limits_p (e, true)
2236 : !can_early_inline_edge_p (e))
2237 continue;
2238
2239 if (e->recursive_p ())
2240 {
2241 if (dump_enabled_p ())
2242 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2243 "Not inlining: recursive call.\n");
2244 continue;
2245 }
2246
2247 if (gimple_in_ssa_p (DECL_STRUCT_FUNCTION (node->decl))
2248 != gimple_in_ssa_p (DECL_STRUCT_FUNCTION (callee->decl)))
2249 {
2250 if (dump_enabled_p ())
2251 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2252 "Not inlining: SSA form does not match.\n");
2253 continue;
2254 }
2255
2256 /* Inline the edge and flatten the inline clone. Avoid
2257 recursing through the original node if the node was cloned. */
2258 if (dump_enabled_p ())
2259 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2260 " Inlining %C into %C.\n",
2261 callee, e->caller);
2262 orig_callee = callee;
2263 inline_call (e, true, NULL, NULL, false);
2264 if (e->callee != orig_callee)
2265 orig_callee->aux = (void *) node;
2266 flatten_function (e->callee, early, false);
2267 if (e->callee != orig_callee)
2268 orig_callee->aux = NULL;
2269 }
2270
2271 node->aux = NULL;
2272 if (update)
2273 ipa_update_overall_fn_summary (node->global.inlined_to
2274 ? node->global.inlined_to : node);
2275 }
2276
2277 /* Inline NODE to all callers. Worker for cgraph_for_node_and_aliases.
2278 DATA points to number of calls originally found so we avoid infinite
2279 recursion. */
2280
2281 static bool
2282 inline_to_all_callers_1 (struct cgraph_node *node, void *data,
2283 hash_set<cgraph_node *> *callers)
2284 {
2285 int *num_calls = (int *)data;
2286 bool callee_removed = false;
2287
2288 while (node->callers && !node->global.inlined_to)
2289 {
2290 struct cgraph_node *caller = node->callers->caller;
2291
2292 if (!can_inline_edge_p (node->callers, true)
2293 || !can_inline_edge_by_limits_p (node->callers, true)
2294 || node->callers->recursive_p ())
2295 {
2296 if (dump_file)
2297 fprintf (dump_file, "Uninlinable call found; giving up.\n");
2298 *num_calls = 0;
2299 return false;
2300 }
2301
2302 if (dump_file)
2303 {
2304 cgraph_node *ultimate = node->ultimate_alias_target ();
2305 fprintf (dump_file,
2306 "\nInlining %s size %i.\n",
2307 ultimate->name (),
2308 ipa_fn_summaries->get (ultimate)->size);
2309 fprintf (dump_file,
2310 " Called once from %s %i insns.\n",
2311 node->callers->caller->name (),
2312 ipa_fn_summaries->get (node->callers->caller)->size);
2313 }
2314
2315 /* Remember which callers we inlined to, delaying updating the
2316 overall summary. */
2317 callers->add (node->callers->caller);
2318 inline_call (node->callers, true, NULL, NULL, false, &callee_removed);
2319 if (dump_file)
2320 fprintf (dump_file,
2321 " Inlined into %s which now has %i size\n",
2322 caller->name (),
2323 ipa_fn_summaries->get (caller)->size);
2324 if (!(*num_calls)--)
2325 {
2326 if (dump_file)
2327 fprintf (dump_file, "New calls found; giving up.\n");
2328 return callee_removed;
2329 }
2330 if (callee_removed)
2331 return true;
2332 }
2333 return false;
2334 }
2335
2336 /* Wrapper around inline_to_all_callers_1 doing delayed overall summary
2337 update. */
2338
2339 static bool
2340 inline_to_all_callers (struct cgraph_node *node, void *data)
2341 {
2342 hash_set<cgraph_node *> callers;
2343 bool res = inline_to_all_callers_1 (node, data, &callers);
2344 /* Perform the delayed update of the overall summary of all callers
2345 processed. This avoids quadratic behavior in the cases where
2346 we have a lot of calls to the same function. */
2347 for (hash_set<cgraph_node *>::iterator i = callers.begin ();
2348 i != callers.end (); ++i)
2349 ipa_update_overall_fn_summary (*i);
2350 return res;
2351 }
2352
2353 /* Output overall time estimate. */
2354 static void
2355 dump_overall_stats (void)
2356 {
2357 sreal sum_weighted = 0, sum = 0;
2358 struct cgraph_node *node;
2359
2360 FOR_EACH_DEFINED_FUNCTION (node)
2361 if (!node->global.inlined_to
2362 && !node->alias)
2363 {
2364 ipa_fn_summary *s = ipa_fn_summaries->get (node);
2365 if (s != NULL)
2366 {
2367 sum += s->time;
2368 if (node->count.ipa ().initialized_p ())
2369 sum_weighted += s->time * node->count.ipa ().to_gcov_type ();
2370 }
2371 }
2372 fprintf (dump_file, "Overall time estimate: "
2373 "%f weighted by profile: "
2374 "%f\n", sum.to_double (), sum_weighted.to_double ());
2375 }
2376
2377 /* Output some useful stats about inlining. */
2378
2379 static void
2380 dump_inline_stats (void)
2381 {
2382 int64_t inlined_cnt = 0, inlined_indir_cnt = 0;
2383 int64_t inlined_virt_cnt = 0, inlined_virt_indir_cnt = 0;
2384 int64_t noninlined_cnt = 0, noninlined_indir_cnt = 0;
2385 int64_t noninlined_virt_cnt = 0, noninlined_virt_indir_cnt = 0;
2386 int64_t inlined_speculative = 0, inlined_speculative_ply = 0;
2387 int64_t indirect_poly_cnt = 0, indirect_cnt = 0;
2388 int64_t reason[CIF_N_REASONS][2];
2389 sreal reason_freq[CIF_N_REASONS];
2390 int i;
2391 struct cgraph_node *node;
2392
2393 memset (reason, 0, sizeof (reason));
2394 for (i=0; i < CIF_N_REASONS; i++)
2395 reason_freq[i] = 0;
2396 FOR_EACH_DEFINED_FUNCTION (node)
2397 {
2398 struct cgraph_edge *e;
2399 for (e = node->callees; e; e = e->next_callee)
2400 {
2401 if (e->inline_failed)
2402 {
2403 if (e->count.ipa ().initialized_p ())
2404 reason[(int) e->inline_failed][0] += e->count.ipa ().to_gcov_type ();
2405 reason_freq[(int) e->inline_failed] += e->sreal_frequency ();
2406 reason[(int) e->inline_failed][1] ++;
2407 if (DECL_VIRTUAL_P (e->callee->decl)
2408 && e->count.ipa ().initialized_p ())
2409 {
2410 if (e->indirect_inlining_edge)
2411 noninlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2412 else
2413 noninlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2414 }
2415 else if (e->count.ipa ().initialized_p ())
2416 {
2417 if (e->indirect_inlining_edge)
2418 noninlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2419 else
2420 noninlined_cnt += e->count.ipa ().to_gcov_type ();
2421 }
2422 }
2423 else if (e->count.ipa ().initialized_p ())
2424 {
2425 if (e->speculative)
2426 {
2427 if (DECL_VIRTUAL_P (e->callee->decl))
2428 inlined_speculative_ply += e->count.ipa ().to_gcov_type ();
2429 else
2430 inlined_speculative += e->count.ipa ().to_gcov_type ();
2431 }
2432 else if (DECL_VIRTUAL_P (e->callee->decl))
2433 {
2434 if (e->indirect_inlining_edge)
2435 inlined_virt_indir_cnt += e->count.ipa ().to_gcov_type ();
2436 else
2437 inlined_virt_cnt += e->count.ipa ().to_gcov_type ();
2438 }
2439 else
2440 {
2441 if (e->indirect_inlining_edge)
2442 inlined_indir_cnt += e->count.ipa ().to_gcov_type ();
2443 else
2444 inlined_cnt += e->count.ipa ().to_gcov_type ();
2445 }
2446 }
2447 }
2448 for (e = node->indirect_calls; e; e = e->next_callee)
2449 if (e->indirect_info->polymorphic
2450 & e->count.ipa ().initialized_p ())
2451 indirect_poly_cnt += e->count.ipa ().to_gcov_type ();
2452 else if (e->count.ipa ().initialized_p ())
2453 indirect_cnt += e->count.ipa ().to_gcov_type ();
2454 }
2455 if (max_count.initialized_p ())
2456 {
2457 fprintf (dump_file,
2458 "Inlined %" PRId64 " + speculative "
2459 "%" PRId64 " + speculative polymorphic "
2460 "%" PRId64 " + previously indirect "
2461 "%" PRId64 " + virtual "
2462 "%" PRId64 " + virtual and previously indirect "
2463 "%" PRId64 "\n" "Not inlined "
2464 "%" PRId64 " + previously indirect "
2465 "%" PRId64 " + virtual "
2466 "%" PRId64 " + virtual and previously indirect "
2467 "%" PRId64 " + stil indirect "
2468 "%" PRId64 " + still indirect polymorphic "
2469 "%" PRId64 "\n", inlined_cnt,
2470 inlined_speculative, inlined_speculative_ply,
2471 inlined_indir_cnt, inlined_virt_cnt, inlined_virt_indir_cnt,
2472 noninlined_cnt, noninlined_indir_cnt, noninlined_virt_cnt,
2473 noninlined_virt_indir_cnt, indirect_cnt, indirect_poly_cnt);
2474 fprintf (dump_file, "Removed speculations ");
2475 spec_rem.dump (dump_file);
2476 fprintf (dump_file, "\n");
2477 }
2478 dump_overall_stats ();
2479 fprintf (dump_file, "\nWhy inlining failed?\n");
2480 for (i = 0; i < CIF_N_REASONS; i++)
2481 if (reason[i][1])
2482 fprintf (dump_file, "%-50s: %8i calls, %8f freq, %" PRId64" count\n",
2483 cgraph_inline_failed_string ((cgraph_inline_failed_t) i),
2484 (int) reason[i][1], reason_freq[i].to_double (), reason[i][0]);
2485 }
2486
2487 /* Called when node is removed. */
2488
2489 static void
2490 flatten_remove_node_hook (struct cgraph_node *node, void *data)
2491 {
2492 if (lookup_attribute ("flatten", DECL_ATTRIBUTES (node->decl)) == NULL)
2493 return;
2494
2495 hash_set<struct cgraph_node *> *removed
2496 = (hash_set<struct cgraph_node *> *) data;
2497 removed->add (node);
2498 }
2499
2500 /* Decide on the inlining. We do so in the topological order to avoid
2501 expenses on updating data structures. */
2502
2503 static unsigned int
2504 ipa_inline (void)
2505 {
2506 struct cgraph_node *node;
2507 int nnodes;
2508 struct cgraph_node **order;
2509 int i, j;
2510 int cold;
2511 bool remove_functions = false;
2512
2513 order = XCNEWVEC (struct cgraph_node *, symtab->cgraph_count);
2514
2515 if (dump_file)
2516 ipa_dump_fn_summaries (dump_file);
2517
2518 nnodes = ipa_reverse_postorder (order);
2519 spec_rem = profile_count::zero ();
2520
2521 FOR_EACH_FUNCTION (node)
2522 {
2523 node->aux = 0;
2524
2525 /* Recompute the default reasons for inlining because they may have
2526 changed during merging. */
2527 if (in_lto_p)
2528 {
2529 for (cgraph_edge *e = node->callees; e; e = e->next_callee)
2530 {
2531 gcc_assert (e->inline_failed);
2532 initialize_inline_failed (e);
2533 }
2534 for (cgraph_edge *e = node->indirect_calls; e; e = e->next_callee)
2535 initialize_inline_failed (e);
2536 }
2537 }
2538
2539 if (dump_file)
2540 fprintf (dump_file, "\nFlattening functions:\n");
2541
2542 /* First shrink order array, so that it only contains nodes with
2543 flatten attribute. */
2544 for (i = nnodes - 1, j = i; i >= 0; i--)
2545 {
2546 node = order[i];
2547 if (lookup_attribute ("flatten",
2548 DECL_ATTRIBUTES (node->decl)) != NULL)
2549 order[j--] = order[i];
2550 }
2551
2552 /* After the above loop, order[j + 1] ... order[nnodes - 1] contain
2553 nodes with flatten attribute. If there is more than one such
2554 node, we need to register a node removal hook, as flatten_function
2555 could remove other nodes with flatten attribute. See PR82801. */
2556 struct cgraph_node_hook_list *node_removal_hook_holder = NULL;
2557 hash_set<struct cgraph_node *> *flatten_removed_nodes = NULL;
2558 if (j < nnodes - 2)
2559 {
2560 flatten_removed_nodes = new hash_set<struct cgraph_node *>;
2561 node_removal_hook_holder
2562 = symtab->add_cgraph_removal_hook (&flatten_remove_node_hook,
2563 flatten_removed_nodes);
2564 }
2565
2566 /* In the first pass handle functions to be flattened. Do this with
2567 a priority so none of our later choices will make this impossible. */
2568 for (i = nnodes - 1; i > j; i--)
2569 {
2570 node = order[i];
2571 if (flatten_removed_nodes
2572 && flatten_removed_nodes->contains (node))
2573 continue;
2574
2575 /* Handle nodes to be flattened.
2576 Ideally when processing callees we stop inlining at the
2577 entry of cycles, possibly cloning that entry point and
2578 try to flatten itself turning it into a self-recursive
2579 function. */
2580 if (dump_file)
2581 fprintf (dump_file, "Flattening %s\n", node->name ());
2582 flatten_function (node, false, true);
2583 }
2584
2585 if (j < nnodes - 2)
2586 {
2587 symtab->remove_cgraph_removal_hook (node_removal_hook_holder);
2588 delete flatten_removed_nodes;
2589 }
2590 free (order);
2591
2592 if (dump_file)
2593 dump_overall_stats ();
2594
2595 inline_small_functions ();
2596
2597 gcc_assert (symtab->state == IPA_SSA);
2598 symtab->state = IPA_SSA_AFTER_INLINING;
2599 /* Do first after-inlining removal. We want to remove all "stale" extern
2600 inline functions and virtual functions so we really know what is called
2601 once. */
2602 symtab->remove_unreachable_nodes (dump_file);
2603
2604 /* Inline functions with a property that after inlining into all callers the
2605 code size will shrink because the out-of-line copy is eliminated.
2606 We do this regardless on the callee size as long as function growth limits
2607 are met. */
2608 if (dump_file)
2609 fprintf (dump_file,
2610 "\nDeciding on functions to be inlined into all callers and "
2611 "removing useless speculations:\n");
2612
2613 /* Inlining one function called once has good chance of preventing
2614 inlining other function into the same callee. Ideally we should
2615 work in priority order, but probably inlining hot functions first
2616 is good cut without the extra pain of maintaining the queue.
2617
2618 ??? this is not really fitting the bill perfectly: inlining function
2619 into callee often leads to better optimization of callee due to
2620 increased context for optimization.
2621 For example if main() function calls a function that outputs help
2622 and then function that does the main optmization, we should inline
2623 the second with priority even if both calls are cold by themselves.
2624
2625 We probably want to implement new predicate replacing our use of
2626 maybe_hot_edge interpreted as maybe_hot_edge || callee is known
2627 to be hot. */
2628 for (cold = 0; cold <= 1; cold ++)
2629 {
2630 FOR_EACH_DEFINED_FUNCTION (node)
2631 {
2632 struct cgraph_edge *edge, *next;
2633 bool update=false;
2634
2635 if (!opt_for_fn (node->decl, optimize)
2636 || !opt_for_fn (node->decl, flag_inline_functions_called_once))
2637 continue;
2638
2639 for (edge = node->callees; edge; edge = next)
2640 {
2641 next = edge->next_callee;
2642 if (edge->speculative && !speculation_useful_p (edge, false))
2643 {
2644 if (edge->count.ipa ().initialized_p ())
2645 spec_rem += edge->count.ipa ();
2646 edge->resolve_speculation ();
2647 update = true;
2648 remove_functions = true;
2649 }
2650 }
2651 if (update)
2652 {
2653 struct cgraph_node *where = node->global.inlined_to
2654 ? node->global.inlined_to : node;
2655 reset_edge_caches (where);
2656 ipa_update_overall_fn_summary (where);
2657 }
2658 if (want_inline_function_to_all_callers_p (node, cold))
2659 {
2660 int num_calls = 0;
2661 node->call_for_symbol_and_aliases (sum_callers, &num_calls,
2662 true);
2663 while (node->call_for_symbol_and_aliases
2664 (inline_to_all_callers, &num_calls, true))
2665 ;
2666 remove_functions = true;
2667 }
2668 }
2669 }
2670
2671 /* Free ipa-prop structures if they are no longer needed. */
2672 ipa_free_all_structures_after_iinln ();
2673
2674 if (dump_enabled_p ())
2675 dump_printf (MSG_NOTE,
2676 "\nInlined %i calls, eliminated %i functions\n\n",
2677 ncalls_inlined, nfunctions_inlined);
2678 if (dump_file)
2679 dump_inline_stats ();
2680
2681 if (dump_file)
2682 ipa_dump_fn_summaries (dump_file);
2683 return remove_functions ? TODO_remove_functions : 0;
2684 }
2685
2686 /* Inline always-inline function calls in NODE. */
2687
2688 static bool
2689 inline_always_inline_functions (struct cgraph_node *node)
2690 {
2691 struct cgraph_edge *e;
2692 bool inlined = false;
2693
2694 for (e = node->callees; e; e = e->next_callee)
2695 {
2696 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2697 if (!DECL_DISREGARD_INLINE_LIMITS (callee->decl))
2698 continue;
2699
2700 if (e->recursive_p ())
2701 {
2702 if (dump_enabled_p ())
2703 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2704 " Not inlining recursive call to %C.\n",
2705 e->callee);
2706 e->inline_failed = CIF_RECURSIVE_INLINING;
2707 continue;
2708 }
2709
2710 if (!can_early_inline_edge_p (e))
2711 {
2712 /* Set inlined to true if the callee is marked "always_inline" but
2713 is not inlinable. This will allow flagging an error later in
2714 expand_call_inline in tree-inline.c. */
2715 if (lookup_attribute ("always_inline",
2716 DECL_ATTRIBUTES (callee->decl)) != NULL)
2717 inlined = true;
2718 continue;
2719 }
2720
2721 if (dump_enabled_p ())
2722 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2723 " Inlining %C into %C (always_inline).\n",
2724 e->callee, e->caller);
2725 inline_call (e, true, NULL, NULL, false);
2726 inlined = true;
2727 }
2728 if (inlined)
2729 ipa_update_overall_fn_summary (node);
2730
2731 return inlined;
2732 }
2733
2734 /* Decide on the inlining. We do so in the topological order to avoid
2735 expenses on updating data structures. */
2736
2737 static bool
2738 early_inline_small_functions (struct cgraph_node *node)
2739 {
2740 struct cgraph_edge *e;
2741 bool inlined = false;
2742
2743 for (e = node->callees; e; e = e->next_callee)
2744 {
2745 struct cgraph_node *callee = e->callee->ultimate_alias_target ();
2746
2747 /* We can enounter not-yet-analyzed function during
2748 early inlining on callgraphs with strongly
2749 connected components. */
2750 ipa_fn_summary *s = ipa_fn_summaries->get (callee);
2751 if (s == NULL || !s->inlinable || !e->inline_failed)
2752 continue;
2753
2754 /* Do not consider functions not declared inline. */
2755 if (!DECL_DECLARED_INLINE_P (callee->decl)
2756 && !opt_for_fn (node->decl, flag_inline_small_functions)
2757 && !opt_for_fn (node->decl, flag_inline_functions))
2758 continue;
2759
2760 if (dump_enabled_p ())
2761 dump_printf_loc (MSG_NOTE, e->call_stmt,
2762 "Considering inline candidate %C.\n",
2763 callee);
2764
2765 if (!can_early_inline_edge_p (e))
2766 continue;
2767
2768 if (e->recursive_p ())
2769 {
2770 if (dump_enabled_p ())
2771 dump_printf_loc (MSG_MISSED_OPTIMIZATION, e->call_stmt,
2772 " Not inlining: recursive call.\n");
2773 continue;
2774 }
2775
2776 if (!want_early_inline_function_p (e))
2777 continue;
2778
2779 if (dump_enabled_p ())
2780 dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, e->call_stmt,
2781 " Inlining %C into %C.\n",
2782 callee, e->caller);
2783 inline_call (e, true, NULL, NULL, false);
2784 inlined = true;
2785 }
2786
2787 if (inlined)
2788 ipa_update_overall_fn_summary (node);
2789
2790 return inlined;
2791 }
2792
2793 unsigned int
2794 early_inliner (function *fun)
2795 {
2796 struct cgraph_node *node = cgraph_node::get (current_function_decl);
2797 struct cgraph_edge *edge;
2798 unsigned int todo = 0;
2799 int iterations = 0;
2800 bool inlined = false;
2801
2802 if (seen_error ())
2803 return 0;
2804
2805 /* Do nothing if datastructures for ipa-inliner are already computed. This
2806 happens when some pass decides to construct new function and
2807 cgraph_add_new_function calls lowering passes and early optimization on
2808 it. This may confuse ourself when early inliner decide to inline call to
2809 function clone, because function clones don't have parameter list in
2810 ipa-prop matching their signature. */
2811 if (ipa_node_params_sum)
2812 return 0;
2813
2814 if (flag_checking)
2815 node->verify ();
2816 node->remove_all_references ();
2817
2818 /* Even when not optimizing or not inlining inline always-inline
2819 functions. */
2820 inlined = inline_always_inline_functions (node);
2821
2822 if (!optimize
2823 || flag_no_inline
2824 || !flag_early_inlining
2825 /* Never inline regular functions into always-inline functions
2826 during incremental inlining. This sucks as functions calling
2827 always inline functions will get less optimized, but at the
2828 same time inlining of functions calling always inline
2829 function into an always inline function might introduce
2830 cycles of edges to be always inlined in the callgraph.
2831
2832 We might want to be smarter and just avoid this type of inlining. */
2833 || (DECL_DISREGARD_INLINE_LIMITS (node->decl)
2834 && lookup_attribute ("always_inline",
2835 DECL_ATTRIBUTES (node->decl))))
2836 ;
2837 else if (lookup_attribute ("flatten",
2838 DECL_ATTRIBUTES (node->decl)) != NULL)
2839 {
2840 /* When the function is marked to be flattened, recursively inline
2841 all calls in it. */
2842 if (dump_enabled_p ())
2843 dump_printf (MSG_OPTIMIZED_LOCATIONS,
2844 "Flattening %C\n", node);
2845 flatten_function (node, true, true);
2846 inlined = true;
2847 }
2848 else
2849 {
2850 /* If some always_inline functions was inlined, apply the changes.
2851 This way we will not account always inline into growth limits and
2852 moreover we will inline calls from always inlines that we skipped
2853 previously because of conditional above. */
2854 if (inlined)
2855 {
2856 timevar_push (TV_INTEGRATION);
2857 todo |= optimize_inline_calls (current_function_decl);
2858 /* optimize_inline_calls call above might have introduced new
2859 statements that don't have inline parameters computed. */
2860 for (edge = node->callees; edge; edge = edge->next_callee)
2861 {
2862 /* We can enounter not-yet-analyzed function during
2863 early inlining on callgraphs with strongly
2864 connected components. */
2865 ipa_call_summary *es = ipa_call_summaries->get_create (edge);
2866 es->call_stmt_size
2867 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2868 es->call_stmt_time
2869 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2870 }
2871 ipa_update_overall_fn_summary (node);
2872 inlined = false;
2873 timevar_pop (TV_INTEGRATION);
2874 }
2875 /* We iterate incremental inlining to get trivial cases of indirect
2876 inlining. */
2877 while (iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS)
2878 && early_inline_small_functions (node))
2879 {
2880 timevar_push (TV_INTEGRATION);
2881 todo |= optimize_inline_calls (current_function_decl);
2882
2883 /* Technically we ought to recompute inline parameters so the new
2884 iteration of early inliner works as expected. We however have
2885 values approximately right and thus we only need to update edge
2886 info that might be cleared out for newly discovered edges. */
2887 for (edge = node->callees; edge; edge = edge->next_callee)
2888 {
2889 /* We have no summary for new bound store calls yet. */
2890 ipa_call_summary *es = ipa_call_summaries->get_create (edge);
2891 es->call_stmt_size
2892 = estimate_num_insns (edge->call_stmt, &eni_size_weights);
2893 es->call_stmt_time
2894 = estimate_num_insns (edge->call_stmt, &eni_time_weights);
2895
2896 if (edge->callee->decl
2897 && !gimple_check_call_matching_types (
2898 edge->call_stmt, edge->callee->decl, false))
2899 {
2900 edge->inline_failed = CIF_MISMATCHED_ARGUMENTS;
2901 edge->call_stmt_cannot_inline_p = true;
2902 }
2903 }
2904 if (iterations < PARAM_VALUE (PARAM_EARLY_INLINER_MAX_ITERATIONS) - 1)
2905 ipa_update_overall_fn_summary (node);
2906 timevar_pop (TV_INTEGRATION);
2907 iterations++;
2908 inlined = false;
2909 }
2910 if (dump_file)
2911 fprintf (dump_file, "Iterations: %i\n", iterations);
2912 }
2913
2914 if (inlined)
2915 {
2916 timevar_push (TV_INTEGRATION);
2917 todo |= optimize_inline_calls (current_function_decl);
2918 timevar_pop (TV_INTEGRATION);
2919 }
2920
2921 fun->always_inline_functions_inlined = true;
2922
2923 return todo;
2924 }
2925
2926 /* Do inlining of small functions. Doing so early helps profiling and other
2927 passes to be somewhat more effective and avoids some code duplication in
2928 later real inlining pass for testcases with very many function calls. */
2929
2930 namespace {
2931
2932 const pass_data pass_data_early_inline =
2933 {
2934 GIMPLE_PASS, /* type */
2935 "einline", /* name */
2936 OPTGROUP_INLINE, /* optinfo_flags */
2937 TV_EARLY_INLINING, /* tv_id */
2938 PROP_ssa, /* properties_required */
2939 0, /* properties_provided */
2940 0, /* properties_destroyed */
2941 0, /* todo_flags_start */
2942 0, /* todo_flags_finish */
2943 };
2944
2945 class pass_early_inline : public gimple_opt_pass
2946 {
2947 public:
2948 pass_early_inline (gcc::context *ctxt)
2949 : gimple_opt_pass (pass_data_early_inline, ctxt)
2950 {}
2951
2952 /* opt_pass methods: */
2953 virtual unsigned int execute (function *);
2954
2955 }; // class pass_early_inline
2956
2957 unsigned int
2958 pass_early_inline::execute (function *fun)
2959 {
2960 return early_inliner (fun);
2961 }
2962
2963 } // anon namespace
2964
2965 gimple_opt_pass *
2966 make_pass_early_inline (gcc::context *ctxt)
2967 {
2968 return new pass_early_inline (ctxt);
2969 }
2970
2971 namespace {
2972
2973 const pass_data pass_data_ipa_inline =
2974 {
2975 IPA_PASS, /* type */
2976 "inline", /* name */
2977 OPTGROUP_INLINE, /* optinfo_flags */
2978 TV_IPA_INLINING, /* tv_id */
2979 0, /* properties_required */
2980 0, /* properties_provided */
2981 0, /* properties_destroyed */
2982 0, /* todo_flags_start */
2983 ( TODO_dump_symtab ), /* todo_flags_finish */
2984 };
2985
2986 class pass_ipa_inline : public ipa_opt_pass_d
2987 {
2988 public:
2989 pass_ipa_inline (gcc::context *ctxt)
2990 : ipa_opt_pass_d (pass_data_ipa_inline, ctxt,
2991 NULL, /* generate_summary */
2992 NULL, /* write_summary */
2993 NULL, /* read_summary */
2994 NULL, /* write_optimization_summary */
2995 NULL, /* read_optimization_summary */
2996 NULL, /* stmt_fixup */
2997 0, /* function_transform_todo_flags_start */
2998 inline_transform, /* function_transform */
2999 NULL) /* variable_transform */
3000 {}
3001
3002 /* opt_pass methods: */
3003 virtual unsigned int execute (function *) { return ipa_inline (); }
3004
3005 }; // class pass_ipa_inline
3006
3007 } // anon namespace
3008
3009 ipa_opt_pass_d *
3010 make_pass_ipa_inline (gcc::context *ctxt)
3011 {
3012 return new pass_ipa_inline (ctxt);
3013 }