1 /* Callgraph based intraprocedural optimizations.
2 Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
3 Contributed by Jan Hubicka
5 This file is part of GCC.
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 2, or (at your option) any later
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
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* This module implements main driver of compilation process as well as
23 few basic intraprocedural optimizers.
25 The main scope of this file is to act as an interface in between
26 tree based frontends and the backend (and middle end)
28 The front-end is supposed to use following functionality:
30 - cgraph_finalize_function
32 This function is called once front-end has parsed whole body of function
33 and it is certain that the function body nor the declaration will change.
35 (There is one exception needed for implementing GCC extern inline function.)
37 - cgraph_varpool_finalize_variable
39 This function has same behavior as the above but is used for static
42 - cgraph_finalize_compilation_unit
44 This function is called once compilation unit is finalized and it will
47 In the unit-at-a-time the call-graph construction and local function
48 analysis takes place here. Bodies of unreachable functions are released
49 to conserve memory usage.
51 ??? The compilation unit in this point of view should be compilation
52 unit as defined by the language - for instance C frontend allows multiple
53 compilation units to be parsed at once and it should call function each
54 time parsing is done so we save memory.
58 In this unit-at-a-time compilation the intra procedural analysis takes
59 place here. In particular the static functions whose address is never
60 taken are marked as local. Backend can then use this information to
61 modify calling conventions, do better inlining or similar optimizations.
63 - cgraph_assemble_pending_functions
64 - cgraph_varpool_assemble_pending_variables
66 In non-unit-at-a-time mode these functions can be used to force compilation
67 of functions or variables that are known to be needed at given stage
70 - cgraph_mark_needed_node
71 - cgraph_varpool_mark_needed_node
73 When function or variable is referenced by some hidden way (for instance
74 via assembly code and marked by attribute "used"), the call-graph data structure
75 must be updated accordingly by this function.
77 - analyze_expr callback
79 This function is responsible for lowering tree nodes not understood by
80 generic code into understandable ones or alternatively marking
81 callgraph and varpool nodes referenced by the as needed.
83 ??? On the tree-ssa genericizing should take place here and we will avoid
84 need for these hooks (replacing them by genericizing hook)
86 - expand_function callback
88 This function is used to expand function and pass it into RTL back-end.
89 Front-end should not make any assumptions about when this function can be
90 called. In particular cgraph_assemble_pending_functions,
91 cgraph_varpool_assemble_pending_variables, cgraph_finalize_function,
92 cgraph_varpool_finalize_function, cgraph_optimize can cause arbitrarily
93 previously finalized functions to be expanded.
95 We implement two compilation modes.
97 - unit-at-a-time: In this mode analyzing of all functions is deferred
98 to cgraph_finalize_compilation_unit and expansion into cgraph_optimize.
100 In cgraph_finalize_compilation_unit the reachable functions are
101 analyzed. During analysis the call-graph edges from reachable
102 functions are constructed and their destinations are marked as
103 reachable. References to functions and variables are discovered too
104 and variables found to be needed output to the assembly file. Via
105 mark_referenced call in assemble_variable functions referenced by
106 static variables are noticed too.
108 The intra-procedural information is produced and its existence
109 indicated by global_info_ready. Once this flag is set it is impossible
110 to change function from !reachable to reachable and thus
111 assemble_variable no longer call mark_referenced.
113 Finally the call-graph is topologically sorted and all reachable functions
114 that has not been completely inlined or are not external are output.
116 ??? It is possible that reference to function or variable is optimized
117 out. We can not deal with this nicely because topological order is not
118 suitable for it. For tree-ssa we may consider another pass doing
119 optimization and re-discovering reachable functions.
121 ??? Reorganize code so variables are output very last and only if they
122 really has been referenced by produced code, so we catch more cases
123 where reference has been optimized out.
127 All functions are variables are output as early as possible to conserve
128 memory consumption. This may or may not result in less memory used but
129 it is still needed for some legacy code that rely on particular ordering
130 of things output from the compiler.
132 Varpool data structures are not used and variables are output directly.
134 Functions are output early using call of
135 cgraph_assemble_pending_function from cgraph_finalize_function. The
136 decision on whether function is needed is made more conservative so
137 uninlininable static functions are needed too. During the call-graph
138 construction the edge destinations are not marked as reachable and it
139 is completely relied upn assemble_variable to mark them.
141 Inlining decision heuristics
142 ??? Move this to separate file after tree-ssa merge.
144 We separate inlining decisions from the inliner itself and store it
145 inside callgraph as so called inline plan. Refer to cgraph.c
146 documentation about particular representation of inline plans in the
149 The implementation of particular heuristics is separated from
150 the rest of code to make it easier to replace it with more complicated
151 implementation in the future. The rest of inlining code acts as a
152 library aimed to modify the callgraph and verify that the parameters
153 on code size growth fits.
155 To mark given call inline, use cgraph_mark_inline function, the
156 verification is performed by cgraph_default_inline_p and
157 cgraph_check_inline_limits.
159 The heuristics implements simple knapsack style algorithm ordering
160 all functions by their "profitability" (estimated by code size growth)
161 and inlining them in priority order.
163 cgraph_decide_inlining implements heuristics taking whole callgraph
164 into account, while cgraph_decide_inlining_incrementally considers
165 only one function at a time and is used in non-unit-at-a-time mode. */
170 #include "coretypes.h"
174 #include "tree-flow.h"
175 #include "tree-inline.h"
176 #include "langhooks.h"
177 #include "pointer-set.h"
184 #include "diagnostic.h"
188 #include "c-common.h"
190 #include "function.h"
191 #include "tree-gimple.h"
194 #define INSNS_PER_CALL 10
196 static void cgraph_expand_all_functions (void);
197 static void cgraph_mark_functions_to_output (void);
198 static void cgraph_expand_function (struct cgraph_node
*);
199 static tree
record_call_1 (tree
*, int *, void *);
200 static void cgraph_mark_local_functions (void);
201 static bool cgraph_default_inline_p (struct cgraph_node
*n
);
202 static void cgraph_analyze_function (struct cgraph_node
*node
);
203 static void cgraph_decide_inlining_incrementally (struct cgraph_node
*);
205 /* Statistics we collect about inlining algorithm. */
206 static int ncalls_inlined
;
207 static int nfunctions_inlined
;
208 static int initial_insns
;
209 static int overall_insns
;
211 /* Records tree nodes seen in cgraph_create_edges. Simply using
212 walk_tree_without_duplicates doesn't guarantee each node is visited
213 once because it gets a new htab upon each recursive call from
215 static struct pointer_set_t
*visited_nodes
;
217 static FILE *cgraph_dump_file
;
219 /* Determine if function DECL is needed. That is, visible to something
220 either outside this translation unit, something magic in the system
221 configury, or (if not doing unit-at-a-time) to something we havn't
225 decide_is_function_needed (struct cgraph_node
*node
, tree decl
)
229 /* If we decided it was needed before, but at the time we didn't have
230 the body of the function available, then it's still needed. We have
231 to go back and re-check its dependencies now. */
235 /* Externally visible functions must be output. The exception is
236 COMDAT functions that must be output only when they are needed. */
237 if (TREE_PUBLIC (decl
) && !DECL_COMDAT (decl
) && !DECL_EXTERNAL (decl
))
240 /* Constructors and destructors are reachable from the runtime by
242 if (DECL_STATIC_CONSTRUCTOR (decl
) || DECL_STATIC_DESTRUCTOR (decl
))
245 /* If the user told us it is used, then it must be so. */
246 if (lookup_attribute ("used", DECL_ATTRIBUTES (decl
)))
249 /* ??? If the assembler name is set by hand, it is possible to assemble
250 the name later after finalizing the function and the fact is noticed
251 in assemble_name then. This is arguably a bug. */
252 if (DECL_ASSEMBLER_NAME_SET_P (decl
)
253 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl
)))
256 if (flag_unit_at_a_time
)
259 /* If not doing unit at a time, then we'll only defer this function
260 if its marked for inlining. Otherwise we want to emit it now. */
262 /* "extern inline" functions are never output locally. */
263 if (DECL_EXTERNAL (decl
))
265 /* Nested functions of extern inline function shall not be emit unless
266 we inlined the origin. */
267 for (origin
= decl_function_context (decl
); origin
;
268 origin
= decl_function_context (origin
))
269 if (DECL_EXTERNAL (origin
))
271 /* We want to emit COMDAT functions only when absolutely necessary. */
272 if (DECL_COMDAT (decl
))
274 if (!DECL_INLINE (decl
)
275 || (!node
->local
.disregard_inline_limits
276 /* When declared inline, defer even the uninlinable functions.
277 This allows them to be eliminated when unused. */
278 && !DECL_DECLARED_INLINE_P (decl
)
279 && (!node
->local
.inlinable
|| !cgraph_default_inline_p (node
))))
285 /* Walk the decls we marked as neccesary and see if they reference new variables
286 or functions and add them into the worklists. */
288 cgraph_varpool_analyze_pending_decls (void)
290 bool changed
= false;
291 timevar_push (TV_CGRAPH
);
293 while (cgraph_varpool_first_unanalyzed_node
)
295 tree decl
= cgraph_varpool_first_unanalyzed_node
->decl
;
297 cgraph_varpool_first_unanalyzed_node
->analyzed
= true;
299 cgraph_varpool_first_unanalyzed_node
= cgraph_varpool_first_unanalyzed_node
->next_needed
;
301 if (DECL_INITIAL (decl
))
302 cgraph_create_edges (NULL
, DECL_INITIAL (decl
));
305 timevar_pop (TV_CGRAPH
);
309 /* Optimization of function bodies might've rendered some variables as
310 unnecesary so we want to avoid these from being compiled.
312 This is done by prunning the queue and keeping only the variables that
313 really appear needed (ie thery are either externally visible or referenced
314 by compiled function). Re-doing the reachability analysis on variables
315 brings back the remaining variables referenced by these. */
317 cgraph_varpool_remove_unreferenced_decls (void)
319 struct cgraph_varpool_node
*next
, *node
= cgraph_varpool_nodes_queue
;
321 cgraph_varpool_reset_queue ();
323 if (errorcount
|| sorrycount
)
328 tree decl
= node
->decl
;
329 next
= node
->next_needed
;
333 && ((DECL_ASSEMBLER_NAME_SET_P (decl
)
334 && TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (decl
)))
335 || node
->force_output
336 || decide_is_variable_needed (node
, decl
)))
337 cgraph_varpool_mark_needed_node (node
);
341 cgraph_varpool_analyze_pending_decls ();
345 /* When not doing unit-at-a-time, output all functions enqueued.
346 Return true when such a functions were found. */
349 cgraph_assemble_pending_functions (void)
353 if (flag_unit_at_a_time
)
356 while (cgraph_nodes_queue
)
358 struct cgraph_node
*n
= cgraph_nodes_queue
;
360 cgraph_nodes_queue
= cgraph_nodes_queue
->next_needed
;
361 n
->next_needed
= NULL
;
362 if (!n
->global
.inlined_to
364 && !DECL_EXTERNAL (n
->decl
))
366 cgraph_expand_function (n
);
374 /* DECL has been parsed. Take it, queue it, compile it at the whim of the
375 logic in effect. If NESTED is true, then our caller cannot stand to have
376 the garbage collector run at the moment. We would need to either create
377 a new GC context, or just not compile right now. */
380 cgraph_finalize_function (tree decl
, bool nested
)
382 struct cgraph_node
*node
= cgraph_node (decl
);
384 if (node
->local
.finalized
)
386 /* As an GCC extension we allow redefinition of the function. The
387 semantics when both copies of bodies differ is not well defined.
388 We replace the old body with new body so in unit at a time mode
389 we always use new body, while in normal mode we may end up with
390 old body inlined into some functions and new body expanded and
393 ??? It may make more sense to use one body for inlining and other
394 body for expanding the function but this is difficult to do. */
396 /* If node->output is set, then this is a unit-at-a-time compilation
397 and we have already begun whole-unit analysis. This is *not*
398 testing for whether we've already emitted the function. That
399 case can be sort-of legitimately seen with real function
400 redefinition errors. I would argue that the front end should
401 never present us with such a case, but don't enforce that for now. */
402 gcc_assert (!node
->output
);
404 /* Reset our data structures so we can analyze the function again. */
405 memset (&node
->local
, 0, sizeof (node
->local
));
406 memset (&node
->global
, 0, sizeof (node
->global
));
407 memset (&node
->rtl
, 0, sizeof (node
->rtl
));
408 node
->analyzed
= false;
409 node
->local
.redefined_extern_inline
= true;
411 if (!flag_unit_at_a_time
)
413 struct cgraph_node
*n
;
415 for (n
= cgraph_nodes
; n
; n
= n
->next
)
416 if (n
->global
.inlined_to
== node
)
417 cgraph_remove_node (n
);
420 cgraph_node_remove_callees (node
);
422 /* We may need to re-queue the node for assembling in case
423 we already proceeded it and ignored as not needed. */
424 if (node
->reachable
&& !flag_unit_at_a_time
)
426 struct cgraph_node
*n
;
428 for (n
= cgraph_nodes_queue
; n
; n
= n
->next_needed
)
436 notice_global_symbol (decl
);
438 node
->local
.finalized
= true;
440 lower_nested_functions (decl
);
441 gcc_assert (!node
->nested
);
443 /* If not unit at a time, then we need to create the call graph
444 now, so that called functions can be queued and emitted now. */
445 if (!flag_unit_at_a_time
)
447 cgraph_analyze_function (node
);
448 cgraph_decide_inlining_incrementally (node
);
451 if (decide_is_function_needed (node
, decl
))
452 cgraph_mark_needed_node (node
);
454 /* If not unit at a time, go ahead and emit everything we've found
455 to be reachable at this time. */
458 if (!cgraph_assemble_pending_functions ())
462 /* If we've not yet emitted decl, tell the debug info about it. */
463 if (!TREE_ASM_WRITTEN (decl
))
464 (*debug_hooks
->deferred_inline_function
) (decl
);
466 /* Possibly warn about unused parameters. */
467 if (warn_unused_parameter
)
468 do_warn_unused_parameter (decl
);
471 /* Walk tree and record all calls. Called via walk_tree. */
473 record_call_1 (tree
*tp
, int *walk_subtrees
, void *data
)
477 switch (TREE_CODE (t
))
480 /* ??? Really, we should mark this decl as *potentially* referenced
481 by this function and re-examine whether the decl is actually used
482 after rtl has been generated. */
483 if (TREE_STATIC (t
) || DECL_EXTERNAL (t
))
485 cgraph_varpool_mark_needed_node (cgraph_varpool_node (t
));
486 if (lang_hooks
.callgraph
.analyze_expr
)
487 return lang_hooks
.callgraph
.analyze_expr (tp
, walk_subtrees
,
493 if (flag_unit_at_a_time
)
495 /* Record dereferences to the functions. This makes the
496 functions reachable unconditionally. */
497 tree decl
= TREE_OPERAND (*tp
, 0);
498 if (TREE_CODE (decl
) == FUNCTION_DECL
)
499 cgraph_mark_needed_node (cgraph_node (decl
));
505 tree decl
= get_callee_fndecl (*tp
);
506 if (decl
&& TREE_CODE (decl
) == FUNCTION_DECL
)
508 cgraph_create_edge (data
, cgraph_node (decl
), *tp
);
510 /* When we see a function call, we don't want to look at the
511 function reference in the ADDR_EXPR that is hanging from
512 the CALL_EXPR we're examining here, because we would
513 conclude incorrectly that the function's address could be
514 taken by something that is not a function call. So only
515 walk the function parameter list, skip the other subtrees. */
517 walk_tree (&TREE_OPERAND (*tp
, 1), record_call_1
, data
,
525 /* Save some cycles by not walking types and declaration as we
526 won't find anything useful there anyway. */
527 if (IS_TYPE_OR_DECL_P (*tp
))
533 if ((unsigned int) TREE_CODE (t
) >= LAST_AND_UNUSED_TREE_CODE
)
534 return lang_hooks
.callgraph
.analyze_expr (tp
, walk_subtrees
, data
);
541 /* Create cgraph edges for function calls inside BODY from NODE. */
544 cgraph_create_edges (struct cgraph_node
*node
, tree body
)
546 /* The nodes we're interested in are never shared, so walk
547 the tree ignoring duplicates. */
548 visited_nodes
= pointer_set_create ();
549 walk_tree (&body
, record_call_1
, node
, visited_nodes
);
550 pointer_set_destroy (visited_nodes
);
551 visited_nodes
= NULL
;
554 static bool error_found
;
556 /* Callback of verify_cgraph_node. Check that all call_exprs have
560 verify_cgraph_node_1 (tree
*tp
, int *walk_subtrees
, void *data
)
565 if (TREE_CODE (t
) == CALL_EXPR
&& (decl
= get_callee_fndecl (t
)))
567 struct cgraph_edge
*e
= cgraph_edge (data
, t
);
572 error ("Shared call_expr:");
576 if (e
->callee
->decl
!= cgraph_node (decl
)->decl
)
578 error ("Edge points to wrong declaration:");
579 debug_tree (e
->callee
->decl
);
580 fprintf (stderr
," Instead of:");
587 error ("Missing callgraph edge for call expr:");
593 /* Save some cycles by not walking types and declaration as we
594 won't find anything useful there anyway. */
595 if (IS_TYPE_OR_DECL_P (*tp
))
601 /* Verify cgraph nodes of given cgraph node. */
603 verify_cgraph_node (struct cgraph_node
*node
)
605 struct cgraph_edge
*e
;
606 struct cgraph_node
*main_clone
;
608 timevar_push (TV_CGRAPH_VERIFY
);
610 for (e
= node
->callees
; e
; e
= e
->next_callee
)
613 error ("Aux field set for edge %s->%s",
614 cgraph_node_name (e
->caller
), cgraph_node_name (e
->callee
));
617 for (e
= node
->callers
; e
; e
= e
->next_caller
)
619 if (!e
->inline_failed
)
621 if (node
->global
.inlined_to
622 != (e
->caller
->global
.inlined_to
623 ? e
->caller
->global
.inlined_to
: e
->caller
))
625 error ("Inlined_to pointer is wrong");
628 if (node
->callers
->next_caller
)
630 error ("Multiple inline callers");
635 if (node
->global
.inlined_to
)
637 error ("Inlined_to pointer set for noninline callers");
641 if (!node
->callers
&& node
->global
.inlined_to
)
643 error ("Inlined_to pointer is set but no predecesors found");
646 if (node
->global
.inlined_to
== node
)
648 error ("Inlined_to pointer reffers to itself");
652 for (main_clone
= cgraph_node (node
->decl
); main_clone
;
653 main_clone
= main_clone
->next_clone
)
654 if (main_clone
== node
)
658 error ("Node not found in DECL_ASSEMBLER_NAME hash");
663 && DECL_SAVED_TREE (node
->decl
) && !TREE_ASM_WRITTEN (node
->decl
)
664 && (!DECL_EXTERNAL (node
->decl
) || node
->global
.inlined_to
))
666 walk_tree_without_duplicates (&DECL_SAVED_TREE (node
->decl
),
667 verify_cgraph_node_1
, node
);
668 for (e
= node
->callees
; e
; e
= e
->next_callee
)
672 error ("Edge %s->%s has no corresponding call_expr",
673 cgraph_node_name (e
->caller
),
674 cgraph_node_name (e
->callee
));
682 dump_cgraph_node (stderr
, node
);
683 internal_error ("verify_cgraph_node failed.");
685 timevar_pop (TV_CGRAPH_VERIFY
);
688 /* Verify whole cgraph structure. */
692 struct cgraph_node
*node
;
694 if (sorrycount
|| errorcount
)
697 for (node
= cgraph_nodes
; node
; node
= node
->next
)
698 verify_cgraph_node (node
);
702 /* Output all variables enqueued to be assembled. */
704 cgraph_varpool_assemble_pending_decls (void)
706 bool changed
= false;
708 if (errorcount
|| sorrycount
)
711 /* EH might mark decls as needed during expansion. This should be safe since
712 we don't create references to new function, but it should not be used
714 cgraph_varpool_analyze_pending_decls ();
716 while (cgraph_varpool_nodes_queue
)
718 tree decl
= cgraph_varpool_nodes_queue
->decl
;
719 struct cgraph_varpool_node
*node
= cgraph_varpool_nodes_queue
;
721 cgraph_varpool_nodes_queue
= cgraph_varpool_nodes_queue
->next_needed
;
722 if (!TREE_ASM_WRITTEN (decl
) && !node
->alias
&& !DECL_EXTERNAL (decl
))
724 assemble_variable (decl
, 0, 1, 0);
727 node
->next_needed
= NULL
;
732 /* Analyze the function scheduled to be output. */
734 cgraph_analyze_function (struct cgraph_node
*node
)
736 tree decl
= node
->decl
;
737 struct cgraph_edge
*e
;
739 current_function_decl
= decl
;
741 /* First kill forward declaration so reverse inlining works properly. */
742 cgraph_create_edges (node
, DECL_SAVED_TREE (decl
));
744 node
->local
.inlinable
= tree_inlinable_function_p (decl
);
745 node
->local
.self_insns
= estimate_num_insns (DECL_SAVED_TREE (decl
));
746 if (node
->local
.inlinable
)
747 node
->local
.disregard_inline_limits
748 = lang_hooks
.tree_inlining
.disregard_inline_limits (decl
);
749 for (e
= node
->callers
; e
; e
= e
->next_caller
)
751 if (node
->local
.redefined_extern_inline
)
752 e
->inline_failed
= N_("redefined extern inline functions are not "
753 "considered for inlining");
754 else if (!node
->local
.inlinable
)
755 e
->inline_failed
= N_("function not inlinable");
757 e
->inline_failed
= N_("function not considered for inlining");
759 if (flag_really_no_inline
&& !node
->local
.disregard_inline_limits
)
760 node
->local
.inlinable
= 0;
761 /* Inlining characteristics are maintained by the cgraph_mark_inline. */
762 node
->global
.insns
= node
->local
.self_insns
;
764 node
->analyzed
= true;
765 current_function_decl
= NULL
;
768 /* Analyze the whole compilation unit once it is parsed completely. */
771 cgraph_finalize_compilation_unit (void)
773 struct cgraph_node
*node
;
774 /* Keep track of already processed nodes when called multiple times for
775 intermodule optmization. */
776 static struct cgraph_node
*first_analyzed
;
780 if (!flag_unit_at_a_time
)
782 cgraph_assemble_pending_functions ();
788 fprintf (stderr
, "\nAnalyzing compilation unit");
792 timevar_push (TV_CGRAPH
);
793 cgraph_varpool_analyze_pending_decls ();
794 if (cgraph_dump_file
)
796 fprintf (cgraph_dump_file
, "Initial entry points:");
797 for (node
= cgraph_nodes
; node
!= first_analyzed
; node
= node
->next
)
798 if (node
->needed
&& DECL_SAVED_TREE (node
->decl
))
799 fprintf (cgraph_dump_file
, " %s", cgraph_node_name (node
));
800 fprintf (cgraph_dump_file
, "\n");
803 /* Propagate reachability flag and lower representation of all reachable
804 functions. In the future, lowering will introduce new functions and
805 new entry points on the way (by template instantiation and virtual
806 method table generation for instance). */
807 while (cgraph_nodes_queue
)
809 struct cgraph_edge
*edge
;
810 tree decl
= cgraph_nodes_queue
->decl
;
812 node
= cgraph_nodes_queue
;
813 cgraph_nodes_queue
= cgraph_nodes_queue
->next_needed
;
814 node
->next_needed
= NULL
;
816 /* ??? It is possible to create extern inline function and later using
817 weak alas attribute to kill its body. See
818 gcc.c-torture/compile/20011119-1.c */
819 if (!DECL_SAVED_TREE (decl
))
822 gcc_assert (!node
->analyzed
&& node
->reachable
);
823 gcc_assert (DECL_SAVED_TREE (decl
));
825 cgraph_analyze_function (node
);
827 for (edge
= node
->callees
; edge
; edge
= edge
->next_callee
)
828 if (!edge
->callee
->reachable
)
829 cgraph_mark_reachable_node (edge
->callee
);
831 cgraph_varpool_analyze_pending_decls ();
834 /* Collect entry points to the unit. */
836 if (cgraph_dump_file
)
838 fprintf (cgraph_dump_file
, "Unit entry points:");
839 for (node
= cgraph_nodes
; node
!= first_analyzed
; node
= node
->next
)
840 if (node
->needed
&& DECL_SAVED_TREE (node
->decl
))
841 fprintf (cgraph_dump_file
, " %s", cgraph_node_name (node
));
842 fprintf (cgraph_dump_file
, "\n\nInitial ");
843 dump_cgraph (cgraph_dump_file
);
846 if (cgraph_dump_file
)
847 fprintf (cgraph_dump_file
, "\nReclaiming functions:");
849 for (node
= cgraph_nodes
; node
!= first_analyzed
; node
= node
->next
)
851 tree decl
= node
->decl
;
853 if (!node
->reachable
&& DECL_SAVED_TREE (decl
))
855 if (cgraph_dump_file
)
856 fprintf (cgraph_dump_file
, " %s", cgraph_node_name (node
));
857 cgraph_remove_node (node
);
860 node
->next_needed
= NULL
;
862 if (cgraph_dump_file
)
864 fprintf (cgraph_dump_file
, "\n\nReclaimed ");
865 dump_cgraph (cgraph_dump_file
);
867 first_analyzed
= cgraph_nodes
;
869 timevar_pop (TV_CGRAPH
);
871 /* Figure out what functions we want to assemble. */
874 cgraph_mark_functions_to_output (void)
876 struct cgraph_node
*node
;
878 for (node
= cgraph_nodes
; node
; node
= node
->next
)
880 tree decl
= node
->decl
;
881 struct cgraph_edge
*e
;
883 gcc_assert (!node
->output
);
885 for (e
= node
->callers
; e
; e
= e
->next_caller
)
886 if (e
->inline_failed
)
889 /* We need to output all local functions that are used and not
890 always inlined, as well as those that are reachable from
891 outside the current compilation unit. */
892 if (DECL_SAVED_TREE (decl
)
893 && !node
->global
.inlined_to
895 || (e
&& node
->reachable
))
896 && !TREE_ASM_WRITTEN (decl
)
897 && !DECL_EXTERNAL (decl
))
901 /* We should've reclaimed all functions that are not needed. */
902 #ifdef ENABLE_CHECKING
903 if (!node
->global
.inlined_to
&& DECL_SAVED_TREE (decl
)
904 && !DECL_EXTERNAL (decl
))
906 dump_cgraph_node (stderr
, node
);
907 internal_error ("failed to reclaim unneeded function");
910 gcc_assert (node
->global
.inlined_to
|| !DECL_SAVED_TREE (decl
)
911 || DECL_EXTERNAL (decl
));
918 /* Expand function specified by NODE. */
921 cgraph_expand_function (struct cgraph_node
*node
)
923 tree decl
= node
->decl
;
925 /* We ought to not compile any inline clones. */
926 gcc_assert (!node
->global
.inlined_to
);
928 if (flag_unit_at_a_time
)
929 announce_function (decl
);
931 /* Generate RTL for the body of DECL. */
932 lang_hooks
.callgraph
.expand_function (decl
);
934 /* Make sure that BE didn't give up on compiling. */
935 /* ??? Can happen with nested function of extern inline. */
936 gcc_assert (TREE_ASM_WRITTEN (node
->decl
));
938 current_function_decl
= NULL
;
939 if (!cgraph_preserve_function_body_p (node
->decl
))
941 DECL_SAVED_TREE (node
->decl
) = NULL
;
942 DECL_STRUCT_FUNCTION (node
->decl
) = NULL
;
943 DECL_INITIAL (node
->decl
) = error_mark_node
;
944 /* Eliminate all call edges. This is important so the call_expr no longer
945 points to the dead function body. */
946 cgraph_node_remove_callees (node
);
950 /* Fill array order with all nodes with output flag set in the reverse
951 topological order. */
954 cgraph_postorder (struct cgraph_node
**order
)
956 struct cgraph_node
*node
, *node2
;
959 struct cgraph_edge
*edge
, last
;
961 struct cgraph_node
**stack
=
962 xcalloc (cgraph_n_nodes
, sizeof (struct cgraph_node
*));
964 /* We have to deal with cycles nicely, so use a depth first traversal
965 output algorithm. Ignore the fact that some functions won't need
966 to be output and put them into order as well, so we get dependencies
967 right through intline functions. */
968 for (node
= cgraph_nodes
; node
; node
= node
->next
)
970 for (node
= cgraph_nodes
; node
; node
= node
->next
)
977 node
->aux
= node
->callers
;
980 while (node2
->aux
!= &last
)
983 if (edge
->next_caller
)
984 node2
->aux
= edge
->next_caller
;
987 if (!edge
->caller
->aux
)
989 if (!edge
->caller
->callers
)
990 edge
->caller
->aux
= &last
;
992 edge
->caller
->aux
= edge
->caller
->callers
;
993 stack
[stack_size
++] = node2
;
994 node2
= edge
->caller
;
998 if (node2
->aux
== &last
)
1000 order
[order_pos
++] = node2
;
1002 node2
= stack
[--stack_size
];
1013 /* Perform reachability analysis and reclaim all unreachable nodes.
1014 This function also remove unneeded bodies of extern inline functions
1015 and thus needs to be done only after inlining decisions has been made. */
1017 cgraph_remove_unreachable_nodes (void)
1019 struct cgraph_node
*first
= (void *) 1;
1020 struct cgraph_node
*node
;
1021 bool changed
= false;
1024 #ifdef ENABLE_CHECKING
1027 if (cgraph_dump_file
)
1028 fprintf (cgraph_dump_file
, "\nReclaiming functions:");
1029 #ifdef ENABLE_CHECKING
1030 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1031 gcc_assert (!node
->aux
);
1033 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1034 if (node
->needed
&& !node
->global
.inlined_to
1035 && (!DECL_EXTERNAL (node
->decl
) || !node
->analyzed
))
1041 gcc_assert (!node
->aux
);
1043 /* Perform reachability analysis. As a special case do not consider
1044 extern inline functions not inlined as live because we won't output
1046 while (first
!= (void *) 1)
1048 struct cgraph_edge
*e
;
1052 for (e
= node
->callees
; e
; e
= e
->next_callee
)
1055 && (!e
->inline_failed
|| !e
->callee
->analyzed
1056 || !DECL_EXTERNAL (e
->callee
->decl
)))
1058 e
->callee
->aux
= first
;
1063 /* Remove unreachable nodes. Extern inline functions need special care;
1064 Unreachable extern inline functions shall be removed.
1065 Reachable extern inline functions we never inlined shall get their bodies
1067 Reachable extern inline functions we sometimes inlined will be turned into
1068 unanalyzed nodes so they look like for true extern functions to the rest
1069 of code. Body of such functions is released via remove_node once the
1070 inline clones are eliminated. */
1071 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1076 tree decl
= node
->decl
;
1078 node
->global
.inlined_to
= NULL
;
1079 if (DECL_STRUCT_FUNCTION (decl
))
1080 local_insns
= node
->local
.self_insns
;
1083 if (cgraph_dump_file
)
1084 fprintf (cgraph_dump_file
, " %s", cgraph_node_name (node
));
1085 if (!node
->analyzed
|| !DECL_EXTERNAL (node
->decl
))
1086 cgraph_remove_node (node
);
1089 struct cgraph_edge
*e
;
1091 for (e
= node
->callers
; e
; e
= e
->next_caller
)
1094 if (e
|| node
->needed
)
1096 struct cgraph_node
*clone
;
1098 for (clone
= node
->next_clone
; clone
;
1099 clone
= clone
->next_clone
)
1104 DECL_SAVED_TREE (node
->decl
) = NULL
;
1105 DECL_STRUCT_FUNCTION (node
->decl
) = NULL
;
1106 DECL_INITIAL (node
->decl
) = error_mark_node
;
1108 cgraph_node_remove_callees (node
);
1109 node
->analyzed
= false;
1112 cgraph_remove_node (node
);
1114 if (!DECL_SAVED_TREE (decl
))
1115 insns
+= local_insns
;
1119 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1121 if (cgraph_dump_file
)
1122 fprintf (cgraph_dump_file
, "\nReclaimed %i insns", insns
);
1126 /* Estimate size of the function after inlining WHAT into TO. */
1129 cgraph_estimate_size_after_inlining (int times
, struct cgraph_node
*to
,
1130 struct cgraph_node
*what
)
1132 tree fndecl
= what
->decl
;
1134 int call_insns
= PARAM_VALUE (PARAM_INLINE_CALL_COST
);
1135 for (arg
= DECL_ARGUMENTS (fndecl
); arg
; arg
= TREE_CHAIN (arg
))
1136 call_insns
+= estimate_move_cost (TREE_TYPE (arg
));
1137 return (what
->global
.insns
- call_insns
) * times
+ to
->global
.insns
;
1140 /* Estimate the growth caused by inlining NODE into all callees. */
1143 cgraph_estimate_growth (struct cgraph_node
*node
)
1146 struct cgraph_edge
*e
;
1148 for (e
= node
->callers
; e
; e
= e
->next_caller
)
1149 if (e
->inline_failed
)
1150 growth
+= (cgraph_estimate_size_after_inlining (1, e
->caller
, node
)
1151 - e
->caller
->global
.insns
);
1153 /* ??? Wrong for self recursive functions or cases where we decide to not
1154 inline for different reasons, but it is not big deal as in that case
1155 we will keep the body around, but we will also avoid some inlining. */
1156 if (!node
->needed
&& !DECL_EXTERNAL (node
->decl
))
1157 growth
-= node
->global
.insns
;
1162 /* E is expected to be an edge being inlined. Clone destination node of
1163 the edge and redirect it to the new clone.
1164 DUPLICATE is used for bookkeeping on whether we are actually creating new
1165 clones or re-using node originally representing out-of-line function call.
1168 cgraph_clone_inlined_nodes (struct cgraph_edge
*e
, bool duplicate
)
1170 struct cgraph_node
*n
;
1172 /* We may eliminate the need for out-of-line copy to be output. In that
1173 case just go ahead and re-use it. */
1174 if (!e
->callee
->callers
->next_caller
1175 && (!e
->callee
->needed
|| DECL_EXTERNAL (e
->callee
->decl
))
1177 && flag_unit_at_a_time
)
1179 gcc_assert (!e
->callee
->global
.inlined_to
);
1180 if (!DECL_EXTERNAL (e
->callee
->decl
))
1181 overall_insns
-= e
->callee
->global
.insns
, nfunctions_inlined
++;
1186 n
= cgraph_clone_node (e
->callee
);
1187 cgraph_redirect_edge_callee (e
, n
);
1190 if (e
->caller
->global
.inlined_to
)
1191 e
->callee
->global
.inlined_to
= e
->caller
->global
.inlined_to
;
1193 e
->callee
->global
.inlined_to
= e
->caller
;
1195 /* Recursively clone all bodies. */
1196 for (e
= e
->callee
->callees
; e
; e
= e
->next_callee
)
1197 if (!e
->inline_failed
)
1198 cgraph_clone_inlined_nodes (e
, duplicate
);
1201 /* Mark edge E as inlined and update callgraph accordingly. */
1204 cgraph_mark_inline_edge (struct cgraph_edge
*e
)
1206 int old_insns
= 0, new_insns
= 0;
1207 struct cgraph_node
*to
= NULL
, *what
;
1209 gcc_assert (e
->inline_failed
);
1210 e
->inline_failed
= NULL
;
1212 if (!e
->callee
->global
.inlined
&& flag_unit_at_a_time
)
1213 DECL_POSSIBLY_INLINED (e
->callee
->decl
) = true;
1214 e
->callee
->global
.inlined
= true;
1216 cgraph_clone_inlined_nodes (e
, true);
1220 /* Now update size of caller and all functions caller is inlined into. */
1221 for (;e
&& !e
->inline_failed
; e
= e
->caller
->callers
)
1223 old_insns
= e
->caller
->global
.insns
;
1224 new_insns
= cgraph_estimate_size_after_inlining (1, e
->caller
,
1226 gcc_assert (new_insns
>= 0);
1228 to
->global
.insns
= new_insns
;
1230 gcc_assert (what
->global
.inlined_to
== to
);
1231 if (new_insns
> old_insns
)
1232 overall_insns
+= new_insns
- old_insns
;
1236 /* Mark all calls of EDGE->CALLEE inlined into EDGE->CALLER.
1237 Return following unredirected edge in the list of callers
1240 static struct cgraph_edge
*
1241 cgraph_mark_inline (struct cgraph_edge
*edge
)
1243 struct cgraph_node
*to
= edge
->caller
;
1244 struct cgraph_node
*what
= edge
->callee
;
1245 struct cgraph_edge
*e
, *next
;
1248 /* Look for all calls, mark them inline and clone recursively
1249 all inlined functions. */
1250 for (e
= what
->callers
; e
; e
= next
)
1252 next
= e
->next_caller
;
1253 if (e
->caller
== to
&& e
->inline_failed
)
1255 cgraph_mark_inline_edge (e
);
1265 /* Return false when inlining WHAT into TO is not good idea
1266 as it would cause too large growth of function bodies. */
1269 cgraph_check_inline_limits (struct cgraph_node
*to
, struct cgraph_node
*what
,
1270 const char **reason
)
1273 struct cgraph_edge
*e
;
1277 if (to
->global
.inlined_to
)
1278 to
= to
->global
.inlined_to
;
1280 for (e
= to
->callees
; e
; e
= e
->next_callee
)
1281 if (e
->callee
== what
)
1284 /* When inlining large function body called once into small function,
1285 take the inlined function as base for limiting the growth. */
1286 if (to
->local
.self_insns
> what
->local
.self_insns
)
1287 limit
= to
->local
.self_insns
;
1289 limit
= what
->local
.self_insns
;
1291 limit
+= limit
* PARAM_VALUE (PARAM_LARGE_FUNCTION_GROWTH
) / 100;
1293 newsize
= cgraph_estimate_size_after_inlining (times
, to
, what
);
1294 if (newsize
> PARAM_VALUE (PARAM_LARGE_FUNCTION_INSNS
)
1298 *reason
= N_("--param large-function-growth limit reached");
1304 /* Return true when function N is small enough to be inlined. */
1307 cgraph_default_inline_p (struct cgraph_node
*n
)
1309 if (!DECL_INLINE (n
->decl
) || !DECL_SAVED_TREE (n
->decl
))
1311 if (DECL_DECLARED_INLINE_P (n
->decl
))
1312 return n
->global
.insns
< MAX_INLINE_INSNS_SINGLE
;
1314 return n
->global
.insns
< MAX_INLINE_INSNS_AUTO
;
1317 /* Return true when inlining WHAT would create recursive inlining.
1318 We call recursive inlining all cases where same function appears more than
1319 once in the single recursion nest path in the inline graph. */
1322 cgraph_recursive_inlining_p (struct cgraph_node
*to
,
1323 struct cgraph_node
*what
,
1324 const char **reason
)
1327 if (to
->global
.inlined_to
)
1328 recursive
= what
->decl
== to
->global
.inlined_to
->decl
;
1330 recursive
= what
->decl
== to
->decl
;
1331 /* Marking recursive function inline has sane semantic and thus we should
1333 if (recursive
&& reason
)
1334 *reason
= (what
->local
.disregard_inline_limits
1335 ? N_("recursive inlining") : "");
1339 /* Recompute heap nodes for each of callees. */
1341 update_callee_keys (fibheap_t heap
, struct fibnode
**heap_node
,
1342 struct cgraph_node
*node
)
1344 struct cgraph_edge
*e
;
1346 for (e
= node
->callees
; e
; e
= e
->next_callee
)
1347 if (e
->inline_failed
&& heap_node
[e
->callee
->uid
])
1348 fibheap_replace_key (heap
, heap_node
[e
->callee
->uid
],
1349 cgraph_estimate_growth (e
->callee
));
1350 else if (!e
->inline_failed
)
1351 update_callee_keys (heap
, heap_node
, e
->callee
);
1354 /* Enqueue all recursive calls from NODE into queue linked via aux pointers
1355 in between FIRST and LAST. WHERE is used for bookkeeping while looking
1356 int calls inlined within NODE. */
1358 lookup_recursive_calls (struct cgraph_node
*node
, struct cgraph_node
*where
,
1359 struct cgraph_edge
**first
, struct cgraph_edge
**last
)
1361 struct cgraph_edge
*e
;
1362 for (e
= where
->callees
; e
; e
= e
->next_callee
)
1363 if (e
->callee
== node
)
1371 for (e
= where
->callees
; e
; e
= e
->next_callee
)
1372 if (!e
->inline_failed
)
1373 lookup_recursive_calls (node
, e
->callee
, first
, last
);
1376 /* Decide on recursive inlining: in the case function has recursive calls,
1377 inline until body size reaches given argument. */
1379 cgraph_decide_recursive_inlining (struct cgraph_node
*node
)
1381 int limit
= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE_AUTO
);
1382 int max_depth
= PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH_AUTO
);
1383 struct cgraph_edge
*first_call
= NULL
, *last_call
= NULL
;
1384 struct cgraph_edge
*last_in_current_depth
;
1385 struct cgraph_edge
*e
;
1386 struct cgraph_node
*master_clone
;
1390 if (DECL_DECLARED_INLINE_P (node
->decl
))
1392 limit
= PARAM_VALUE (PARAM_MAX_INLINE_INSNS_RECURSIVE
);
1393 max_depth
= PARAM_VALUE (PARAM_MAX_INLINE_RECURSIVE_DEPTH
);
1396 /* Make sure that function is small enough to be considered for inlining. */
1398 || cgraph_estimate_size_after_inlining (1, node
, node
) >= limit
)
1400 lookup_recursive_calls (node
, node
, &first_call
, &last_call
);
1404 if (cgraph_dump_file
)
1405 fprintf (cgraph_dump_file
,
1406 "\nPerforming recursive inlining on %s\n",
1407 cgraph_node_name (node
));
1409 /* We need original clone to copy around. */
1410 master_clone
= cgraph_clone_node (node
);
1411 master_clone
->needed
= true;
1412 for (e
= master_clone
->callees
; e
; e
= e
->next_callee
)
1413 if (!e
->inline_failed
)
1414 cgraph_clone_inlined_nodes (e
, true);
1416 /* Do the inlining and update list of recursive call during process. */
1417 last_in_current_depth
= last_call
;
1419 && cgraph_estimate_size_after_inlining (1, node
, master_clone
) <= limit
)
1421 struct cgraph_edge
*curr
= first_call
;
1423 first_call
= first_call
->aux
;
1426 cgraph_redirect_edge_callee (curr
, master_clone
);
1427 cgraph_mark_inline_edge (curr
);
1428 lookup_recursive_calls (node
, curr
->callee
, &first_call
, &last_call
);
1430 if (last_in_current_depth
1431 && ++depth
>= max_depth
)
1436 /* Cleanup queue pointers. */
1439 struct cgraph_edge
*next
= first_call
->aux
;
1440 first_call
->aux
= NULL
;
1443 if (cgraph_dump_file
)
1444 fprintf (cgraph_dump_file
,
1445 "\n Inlined %i times, body grown from %i to %i insns\n", n
,
1446 master_clone
->global
.insns
, node
->global
.insns
);
1448 /* Remove master clone we used for inlining. We rely that clones inlined
1449 into master clone gets queued just before master clone so we don't
1451 for (node
= cgraph_nodes
; node
!= master_clone
;
1453 if (node
->global
.inlined_to
== master_clone
)
1454 cgraph_remove_node (node
);
1455 cgraph_remove_node (master_clone
);
1458 /* Set inline_failed for all callers of given function to REASON. */
1461 cgraph_set_inline_failed (struct cgraph_node
*node
, const char *reason
)
1463 struct cgraph_edge
*e
;
1465 if (cgraph_dump_file
)
1466 fprintf (cgraph_dump_file
, "Inlining failed: %s\n", reason
);
1467 for (e
= node
->callers
; e
; e
= e
->next_caller
)
1468 if (e
->inline_failed
)
1469 e
->inline_failed
= reason
;
1472 /* We use greedy algorithm for inlining of small functions:
1473 All inline candidates are put into prioritized heap based on estimated
1474 growth of the overall number of instructions and then update the estimates.
1476 INLINED and INLINED_CALEES are just pointers to arrays large enough
1477 to be passed to cgraph_inlined_into and cgraph_inlined_callees. */
1480 cgraph_decide_inlining_of_small_functions (void)
1482 struct cgraph_node
*node
;
1483 fibheap_t heap
= fibheap_new ();
1484 struct fibnode
**heap_node
=
1485 xcalloc (cgraph_max_uid
, sizeof (struct fibnode
*));
1486 int max_insns
= ((HOST_WIDEST_INT
) initial_insns
1487 * (100 + PARAM_VALUE (PARAM_INLINE_UNIT_GROWTH
)) / 100);
1489 /* Put all inline candidates into the heap. */
1491 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1493 if (!node
->local
.inlinable
|| !node
->callers
1494 || node
->local
.disregard_inline_limits
)
1497 if (!cgraph_default_inline_p (node
))
1499 cgraph_set_inline_failed (node
,
1500 N_("--param max-inline-insns-single limit reached"));
1503 heap_node
[node
->uid
] =
1504 fibheap_insert (heap
, cgraph_estimate_growth (node
), node
);
1507 if (cgraph_dump_file
)
1508 fprintf (cgraph_dump_file
, "\nDeciding on smaller functions:\n");
1509 while (overall_insns
<= max_insns
&& (node
= fibheap_extract_min (heap
)))
1511 struct cgraph_edge
*e
, *next
;
1512 int old_insns
= overall_insns
;
1514 heap_node
[node
->uid
] = NULL
;
1515 if (cgraph_dump_file
)
1516 fprintf (cgraph_dump_file
,
1517 "\nConsidering %s with %i insns\n"
1518 " Estimated growth is %+i insns.\n",
1519 cgraph_node_name (node
), node
->global
.insns
,
1520 cgraph_estimate_growth (node
));
1521 if (!cgraph_default_inline_p (node
))
1523 cgraph_set_inline_failed (node
,
1524 N_("--param max-inline-insns-single limit reached after inlining into the callee"));
1527 for (e
= node
->callers
; e
; e
= next
)
1529 next
= e
->next_caller
;
1530 if (e
->inline_failed
)
1532 struct cgraph_node
*where
;
1534 if (cgraph_recursive_inlining_p (e
->caller
, e
->callee
,
1536 || !cgraph_check_inline_limits (e
->caller
, e
->callee
,
1539 if (cgraph_dump_file
)
1540 fprintf (cgraph_dump_file
, " Not inlining into %s:%s.\n",
1541 cgraph_node_name (e
->caller
), e
->inline_failed
);
1544 next
= cgraph_mark_inline (e
);
1546 if (where
->global
.inlined_to
)
1547 where
= where
->global
.inlined_to
;
1549 if (heap_node
[where
->uid
])
1550 fibheap_replace_key (heap
, heap_node
[where
->uid
],
1551 cgraph_estimate_growth (where
));
1553 if (cgraph_dump_file
)
1554 fprintf (cgraph_dump_file
,
1555 " Inlined into %s which now has %i insns.\n",
1556 cgraph_node_name (e
->caller
),
1557 e
->caller
->global
.insns
);
1561 cgraph_decide_recursive_inlining (node
);
1563 /* Similarly all functions called by the function we just inlined
1564 are now called more times; update keys. */
1565 update_callee_keys (heap
, heap_node
, node
);
1567 if (cgraph_dump_file
)
1568 fprintf (cgraph_dump_file
,
1569 " Inlined for a net change of %+i insns.\n",
1570 overall_insns
- old_insns
);
1572 while ((node
= fibheap_extract_min (heap
)) != NULL
)
1573 if (!node
->local
.disregard_inline_limits
)
1574 cgraph_set_inline_failed (node
, N_("--param inline-unit-growth limit reached"));
1575 fibheap_delete (heap
);
1579 /* Decide on the inlining. We do so in the topological order to avoid
1580 expenses on updating data structures. */
1583 cgraph_decide_inlining (void)
1585 struct cgraph_node
*node
;
1587 struct cgraph_node
**order
=
1588 xcalloc (cgraph_n_nodes
, sizeof (struct cgraph_node
*));
1592 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1593 initial_insns
+= node
->local
.self_insns
;
1594 overall_insns
= initial_insns
;
1596 nnodes
= cgraph_postorder (order
);
1598 if (cgraph_dump_file
)
1599 fprintf (cgraph_dump_file
,
1600 "\nDeciding on inlining. Starting with %i insns.\n",
1603 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1606 if (cgraph_dump_file
)
1607 fprintf (cgraph_dump_file
, "\nInlining always_inline functions:\n");
1609 /* In the first pass mark all always_inline edges. Do this with a priority
1610 so none of our later choices will make this impossible. */
1611 for (i
= nnodes
- 1; i
>= 0; i
--)
1613 struct cgraph_edge
*e
, *next
;
1617 if (!node
->local
.disregard_inline_limits
)
1619 if (cgraph_dump_file
)
1620 fprintf (cgraph_dump_file
,
1621 "\nConsidering %s %i insns (always inline)\n",
1622 cgraph_node_name (node
), node
->global
.insns
);
1623 old_insns
= overall_insns
;
1624 for (e
= node
->callers
; e
; e
= next
)
1626 next
= e
->next_caller
;
1627 if (!e
->inline_failed
)
1629 if (cgraph_recursive_inlining_p (e
->caller
, e
->callee
,
1632 cgraph_mark_inline_edge (e
);
1633 if (cgraph_dump_file
)
1634 fprintf (cgraph_dump_file
,
1635 " Inlined into %s which now has %i insns.\n",
1636 cgraph_node_name (e
->caller
),
1637 e
->caller
->global
.insns
);
1639 if (cgraph_dump_file
)
1640 fprintf (cgraph_dump_file
,
1641 " Inlined for a net change of %+i insns.\n",
1642 overall_insns
- old_insns
);
1645 if (!flag_really_no_inline
)
1647 cgraph_decide_inlining_of_small_functions ();
1649 if (cgraph_dump_file
)
1650 fprintf (cgraph_dump_file
, "\nDeciding on functions called once:\n");
1652 /* And finally decide what functions are called once. */
1654 for (i
= nnodes
- 1; i
>= 0; i
--)
1658 if (node
->callers
&& !node
->callers
->next_caller
&& !node
->needed
1659 && node
->local
.inlinable
&& node
->callers
->inline_failed
1660 && !DECL_EXTERNAL (node
->decl
) && !DECL_COMDAT (node
->decl
))
1663 struct cgraph_node
*node1
;
1665 /* Verify that we won't duplicate the caller. */
1666 for (node1
= node
->callers
->caller
;
1667 node1
->callers
&& !node1
->callers
->inline_failed
1668 && ok
; node1
= node1
->callers
->caller
)
1669 if (node1
->callers
->next_caller
|| node1
->needed
)
1673 if (cgraph_dump_file
)
1674 fprintf (cgraph_dump_file
,
1675 "\nConsidering %s %i insns.\n"
1676 " Called once from %s %i insns.\n",
1677 cgraph_node_name (node
), node
->global
.insns
,
1678 cgraph_node_name (node
->callers
->caller
),
1679 node
->callers
->caller
->global
.insns
);
1681 old_insns
= overall_insns
;
1683 if (cgraph_check_inline_limits (node
->callers
->caller
, node
,
1686 cgraph_mark_inline (node
->callers
);
1687 if (cgraph_dump_file
)
1688 fprintf (cgraph_dump_file
,
1689 " Inlined into %s which now has %i insns"
1690 " for a net change of %+i insns.\n",
1691 cgraph_node_name (node
->callers
->caller
),
1692 node
->callers
->caller
->global
.insns
,
1693 overall_insns
- old_insns
);
1697 if (cgraph_dump_file
)
1698 fprintf (cgraph_dump_file
,
1699 " Inline limit reached, not inlined.\n");
1706 /* We will never output extern functions we didn't inline.
1707 ??? Perhaps we can prevent accounting of growth of external
1708 inline functions. */
1709 cgraph_remove_unreachable_nodes ();
1711 if (cgraph_dump_file
)
1712 fprintf (cgraph_dump_file
,
1713 "\nInlined %i calls, eliminated %i functions, "
1714 "%i insns turned to %i insns.\n\n",
1715 ncalls_inlined
, nfunctions_inlined
, initial_insns
,
1720 /* Decide on the inlining. We do so in the topological order to avoid
1721 expenses on updating data structures. */
1724 cgraph_decide_inlining_incrementally (struct cgraph_node
*node
)
1726 struct cgraph_edge
*e
;
1728 /* First of all look for always inline functions. */
1729 for (e
= node
->callees
; e
; e
= e
->next_callee
)
1730 if (e
->callee
->local
.disregard_inline_limits
1732 && !cgraph_recursive_inlining_p (node
, e
->callee
, &e
->inline_failed
)
1733 /* ??? It is possible that renaming variable removed the function body
1734 in duplicate_decls. See gcc.c-torture/compile/20011119-2.c */
1735 && DECL_SAVED_TREE (e
->callee
->decl
))
1736 cgraph_mark_inline (e
);
1738 /* Now do the automatic inlining. */
1739 if (!flag_really_no_inline
)
1740 for (e
= node
->callees
; e
; e
= e
->next_callee
)
1741 if (e
->callee
->local
.inlinable
1743 && !e
->callee
->local
.disregard_inline_limits
1744 && !cgraph_recursive_inlining_p (node
, e
->callee
, &e
->inline_failed
)
1745 && cgraph_check_inline_limits (node
, e
->callee
, &e
->inline_failed
)
1746 && DECL_SAVED_TREE (e
->callee
->decl
))
1748 if (cgraph_default_inline_p (e
->callee
))
1749 cgraph_mark_inline (e
);
1752 = N_("--param max-inline-insns-single limit reached");
1757 /* Return true when CALLER_DECL should be inlined into CALLEE_DECL. */
1760 cgraph_inline_p (struct cgraph_edge
*e
, const char **reason
)
1762 *reason
= e
->inline_failed
;
1763 return !e
->inline_failed
;
1768 /* Expand all functions that must be output.
1770 Attempt to topologically sort the nodes so function is output when
1771 all called functions are already assembled to allow data to be
1772 propagated across the callgraph. Use a stack to get smaller distance
1773 between a function and its callees (later we may choose to use a more
1774 sophisticated algorithm for function reordering; we will likely want
1775 to use subsections to make the output functions appear in top-down
1779 cgraph_expand_all_functions (void)
1781 struct cgraph_node
*node
;
1782 struct cgraph_node
**order
=
1783 xcalloc (cgraph_n_nodes
, sizeof (struct cgraph_node
*));
1784 int order_pos
= 0, new_order_pos
= 0;
1787 order_pos
= cgraph_postorder (order
);
1788 gcc_assert (order_pos
== cgraph_n_nodes
);
1790 /* Garbage collector may remove inline clones we eliminate during
1791 optimization. So we must be sure to not reference them. */
1792 for (i
= 0; i
< order_pos
; i
++)
1793 if (order
[i
]->output
)
1794 order
[new_order_pos
++] = order
[i
];
1796 for (i
= new_order_pos
- 1; i
>= 0; i
--)
1801 gcc_assert (node
->reachable
);
1803 cgraph_expand_function (node
);
1809 /* Mark all local functions.
1811 A local function is one whose calls can occur only in the current
1812 compilation unit and all its calls are explicit, so we can change
1813 its calling convention. We simply mark all static functions whose
1814 address is not taken as local. */
1817 cgraph_mark_local_functions (void)
1819 struct cgraph_node
*node
;
1821 /* Figure out functions we want to assemble. */
1822 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1824 node
->local
.local
= (!node
->needed
1825 && DECL_SAVED_TREE (node
->decl
)
1826 && !TREE_PUBLIC (node
->decl
));
1829 if (cgraph_dump_file
)
1831 fprintf (cgraph_dump_file
, "\nMarking local functions:");
1832 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1833 if (node
->local
.local
)
1834 fprintf (cgraph_dump_file
, " %s", cgraph_node_name (node
));
1835 fprintf (cgraph_dump_file
, "\n\n");
1839 /* Return true when function body of DECL still needs to be kept around
1840 for later re-use. */
1842 cgraph_preserve_function_body_p (tree decl
)
1844 struct cgraph_node
*node
;
1845 /* Keep the body; we're going to dump it. */
1846 if (dump_enabled_p (TDI_tree_all
))
1848 if (!cgraph_global_info_ready
)
1849 return (DECL_INLINE (decl
) && !flag_really_no_inline
);
1850 /* Look if there is any clone around. */
1851 for (node
= cgraph_node (decl
); node
; node
= node
->next_clone
)
1852 if (node
->global
.inlined_to
)
1857 /* Perform simple optimizations based on callgraph. */
1860 cgraph_optimize (void)
1862 #ifdef ENABLE_CHECKING
1865 if (!flag_unit_at_a_time
)
1867 cgraph_varpool_assemble_pending_decls ();
1871 process_pending_assemble_externals ();
1873 /* Frontend may output common variables after the unit has been finalized.
1874 It is safe to deal with them here as they are always zero initialized. */
1875 cgraph_varpool_analyze_pending_decls ();
1877 timevar_push (TV_CGRAPHOPT
);
1879 fprintf (stderr
, "Performing intraprocedural optimizations\n");
1881 cgraph_mark_local_functions ();
1882 if (cgraph_dump_file
)
1884 fprintf (cgraph_dump_file
, "Marked ");
1885 dump_cgraph (cgraph_dump_file
);
1888 if (flag_inline_trees
)
1889 cgraph_decide_inlining ();
1890 cgraph_global_info_ready
= true;
1891 if (cgraph_dump_file
)
1893 fprintf (cgraph_dump_file
, "Optimized ");
1894 dump_cgraph (cgraph_dump_file
);
1895 dump_varpool (cgraph_dump_file
);
1897 timevar_pop (TV_CGRAPHOPT
);
1899 /* Output everything. */
1901 fprintf (stderr
, "Assembling functions:\n");
1902 #ifdef ENABLE_CHECKING
1906 cgraph_mark_functions_to_output ();
1907 cgraph_expand_all_functions ();
1908 cgraph_varpool_remove_unreferenced_decls ();
1910 cgraph_varpool_assemble_pending_decls ();
1912 if (cgraph_dump_file
)
1914 fprintf (cgraph_dump_file
, "\nFinal ");
1915 dump_cgraph (cgraph_dump_file
);
1917 #ifdef ENABLE_CHECKING
1919 /* Double check that all inline clones are gone and that all
1920 function bodies have been released from memory. */
1921 if (flag_unit_at_a_time
1922 && !dump_enabled_p (TDI_tree_all
)
1923 && !(sorrycount
|| errorcount
))
1925 struct cgraph_node
*node
;
1926 bool error_found
= false;
1928 for (node
= cgraph_nodes
; node
; node
= node
->next
)
1930 && (node
->global
.inlined_to
1931 || DECL_SAVED_TREE (node
->decl
)))
1934 dump_cgraph_node (stderr
, node
);
1937 internal_error ("Nodes with no released memory found.");
1942 /* Generate and emit a static constructor or destructor. WHICH must be
1943 one of 'I' or 'D'. BODY should be a STATEMENT_LIST containing
1944 GENERIC statements. */
1947 cgraph_build_static_cdtor (char which
, tree body
, int priority
)
1949 static int counter
= 0;
1951 tree decl
, name
, resdecl
;
1953 sprintf (which_buf
, "%c_%d", which
, counter
++);
1954 name
= get_file_function_name_long (which_buf
);
1956 decl
= build_decl (FUNCTION_DECL
, name
,
1957 build_function_type (void_type_node
, void_list_node
));
1958 current_function_decl
= decl
;
1960 resdecl
= build_decl (RESULT_DECL
, NULL_TREE
, void_type_node
);
1961 DECL_ARTIFICIAL (resdecl
) = 1;
1962 DECL_IGNORED_P (resdecl
) = 1;
1963 DECL_RESULT (decl
) = resdecl
;
1965 allocate_struct_function (decl
);
1967 TREE_STATIC (decl
) = 1;
1968 TREE_USED (decl
) = 1;
1969 DECL_ARTIFICIAL (decl
) = 1;
1970 DECL_IGNORED_P (decl
) = 1;
1971 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (decl
) = 1;
1972 DECL_SAVED_TREE (decl
) = body
;
1973 TREE_PUBLIC (decl
) = ! targetm
.have_ctors_dtors
;
1974 DECL_UNINLINABLE (decl
) = 1;
1976 DECL_INITIAL (decl
) = make_node (BLOCK
);
1977 TREE_USED (DECL_INITIAL (decl
)) = 1;
1979 DECL_SOURCE_LOCATION (decl
) = input_location
;
1980 cfun
->function_end_locus
= input_location
;
1985 DECL_STATIC_CONSTRUCTOR (decl
) = 1;
1988 DECL_STATIC_DESTRUCTOR (decl
) = 1;
1994 gimplify_function_tree (decl
);
1996 /* ??? We will get called LATE in the compilation process. */
1997 if (cgraph_global_info_ready
)
1998 tree_rest_of_compilation (decl
);
2000 cgraph_finalize_function (decl
, 0);
2002 if (targetm
.have_ctors_dtors
)
2004 void (*fn
) (rtx
, int);
2007 fn
= targetm
.asm_out
.constructor
;
2009 fn
= targetm
.asm_out
.destructor
;
2010 fn (XEXP (DECL_RTL (decl
), 0), priority
);
2017 cgraph_dump_file
= dump_begin (TDI_cgraph
, NULL
);