1 /* Control and data flow functions for trees.
2 Copyright 2001 Free Software Foundation, Inc.
3 Contributed by Alexandre Oliva <aoliva@redhat.com>
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
26 #include "tree-inline.h"
32 #include "insn-config.h"
33 #include "integrate.h"
36 #include "splay-tree.h"
37 #include "langhooks.h"
39 /* This should be eventually be generalized to other languages, but
40 this would require a shared function-as-trees infrastructure. */
43 /* 0 if we should not perform inlining.
44 1 if we should expand functions calls inline at the tree level.
45 2 if we should consider *all* functions to be inline
48 int flag_inline_trees
= 0;
52 o In order to make inlining-on-trees work, we pessimized
53 function-local static constants. In particular, they are now
54 always output, even when not addressed. Fix this by treating
55 function-local static constants just like global static
56 constants; the back-end already knows not to output them if they
59 o Provide heuristics to clamp inlining of recursive template
62 /* Data required for function inlining. */
64 typedef struct inline_data
66 /* A stack of the functions we are inlining. For example, if we are
67 compiling `f', which calls `g', which calls `h', and we are
68 inlining the body of `h', the stack will contain, `h', followed
69 by `g', followed by `f'. The first few elements of the stack may
70 contain other functions that we know we should not recurse into,
71 even though they are not directly being inlined. */
73 /* The index of the first element of FNS that really represents an
75 unsigned first_inlined_fn
;
76 /* The label to jump to when a return statement is encountered. If
77 this value is NULL, then return statements will simply be
78 remapped as return statements, rather than as jumps. */
80 /* The map from local declarations in the inlined function to
81 equivalents in the function into which it is being inlined. */
83 /* Nonzero if we are currently within the cleanup for a
85 int in_target_cleanup_p
;
86 /* A stack of the TARGET_EXPRs that we are currently processing. */
87 varray_type target_exprs
;
88 /* A list of the functions current function has inlined. */
89 varray_type inlined_fns
;
90 /* The approximate number of statements we have inlined in the
91 current call stack. */
93 /* We use the same mechanism to build clones that we do to perform
94 inlining. However, there are a few places where we need to
95 distinguish between those two situations. This flag is true if
96 we are cloning, rather than inlining. */
98 /* Hash table used to prevent walk_tree from visiting the same node
99 umpteen million times. */
105 static tree initialize_inlined_parameters
PARAMS ((inline_data
*, tree
, tree
));
106 static tree declare_return_variable
PARAMS ((inline_data
*, tree
*));
107 static tree copy_body_r
PARAMS ((tree
*, int *, void *));
108 static tree copy_body
PARAMS ((inline_data
*));
109 static tree expand_call_inline
PARAMS ((tree
*, int *, void *));
110 static void expand_calls_inline
PARAMS ((tree
*, inline_data
*));
111 static int inlinable_function_p
PARAMS ((tree
, inline_data
*));
112 static tree remap_decl
PARAMS ((tree
, inline_data
*));
113 static void remap_block
PARAMS ((tree
, tree
, inline_data
*));
114 static void copy_scope_stmt
PARAMS ((tree
*, int *, inline_data
*));
116 /* The approximate number of instructions per statement. This number
117 need not be particularly accurate; it is used only to make
118 decisions about when a function is too big to inline. */
119 #define INSNS_PER_STMT (10)
121 /* Remap DECL during the copying of the BLOCK tree for the function. */
124 remap_decl (decl
, id
)
131 /* We only remap local variables in the current function. */
132 fn
= VARRAY_TOP_TREE (id
->fns
);
133 if (! (*lang_hooks
.tree_inlining
.auto_var_in_fn_p
) (decl
, fn
))
136 /* See if we have remapped this declaration. */
137 n
= splay_tree_lookup (id
->decl_map
, (splay_tree_key
) decl
);
138 /* If we didn't already have an equivalent for this declaration,
144 /* Make a copy of the variable or label. */
145 t
= copy_decl_for_inlining (decl
, fn
,
146 VARRAY_TREE (id
->fns
, 0));
148 /* The decl T could be a dynamic array or other variable size type,
149 in which case some fields need to be remapped because they may
150 contain SAVE_EXPRs. */
151 if (TREE_TYPE (t
) && TREE_CODE (TREE_TYPE (t
)) == ARRAY_TYPE
152 && TYPE_DOMAIN (TREE_TYPE (t
)))
154 TREE_TYPE (t
) = copy_node (TREE_TYPE (t
));
155 TYPE_DOMAIN (TREE_TYPE (t
))
156 = copy_node (TYPE_DOMAIN (TREE_TYPE (t
)));
157 walk_tree (&TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (t
))),
158 copy_body_r
, id
, NULL
);
161 if (! DECL_NAME (t
) && TREE_TYPE (t
)
162 && (*lang_hooks
.tree_inlining
.anon_aggr_type_p
) (TREE_TYPE (t
)))
164 /* For a VAR_DECL of anonymous type, we must also copy the
165 member VAR_DECLS here and rechain the
166 DECL_ANON_UNION_ELEMS. */
170 for (src
= DECL_ANON_UNION_ELEMS (t
); src
;
171 src
= TREE_CHAIN (src
))
173 tree member
= remap_decl (TREE_VALUE (src
), id
);
175 if (TREE_PURPOSE (src
))
177 members
= tree_cons (NULL
, member
, members
);
179 DECL_ANON_UNION_ELEMS (t
) = nreverse (members
);
182 /* Remember it, so that if we encounter this local entity
183 again we can reuse this copy. */
184 n
= splay_tree_insert (id
->decl_map
,
185 (splay_tree_key
) decl
,
186 (splay_tree_value
) t
);
189 return (tree
) n
->value
;
192 /* Copy the SCOPE_STMT_BLOCK associated with SCOPE_STMT to contain
193 remapped versions of the variables therein. And hook the new block
194 into the block-tree. If non-NULL, the DECLS are declarations to
195 add to use instead of the BLOCK_VARS in the old block. */
198 remap_block (scope_stmt
, decls
, id
)
203 /* We cannot do this in the cleanup for a TARGET_EXPR since we do
204 not know whether or not expand_expr will actually write out the
205 code we put there. If it does not, then we'll have more BLOCKs
206 than block-notes, and things will go awry. At some point, we
207 should make the back-end handle BLOCK notes in a tidier way,
208 without requiring a strict correspondence to the block-tree; then
209 this check can go. */
210 if (id
->in_target_cleanup_p
)
212 SCOPE_STMT_BLOCK (scope_stmt
) = NULL_TREE
;
216 /* If this is the beginning of a scope, remap the associated BLOCK. */
217 if (SCOPE_BEGIN_P (scope_stmt
) && SCOPE_STMT_BLOCK (scope_stmt
))
224 /* Make the new block. */
225 old_block
= SCOPE_STMT_BLOCK (scope_stmt
);
226 new_block
= make_node (BLOCK
);
227 TREE_USED (new_block
) = TREE_USED (old_block
);
228 BLOCK_ABSTRACT_ORIGIN (new_block
) = old_block
;
229 SCOPE_STMT_BLOCK (scope_stmt
) = new_block
;
231 /* Remap its variables. */
232 for (old_var
= decls
? decls
: BLOCK_VARS (old_block
);
234 old_var
= TREE_CHAIN (old_var
))
238 /* Remap the variable. */
239 new_var
= remap_decl (old_var
, id
);
240 /* If we didn't remap this variable, so we can't mess with
241 its TREE_CHAIN. If we remapped this variable to
242 something other than a declaration (say, if we mapped it
243 to a constant), then we must similarly omit any mention
245 if (!new_var
|| !DECL_P (new_var
))
249 TREE_CHAIN (new_var
) = BLOCK_VARS (new_block
);
250 BLOCK_VARS (new_block
) = new_var
;
253 /* We put the BLOCK_VARS in reverse order; fix that now. */
254 BLOCK_VARS (new_block
) = nreverse (BLOCK_VARS (new_block
));
255 fn
= VARRAY_TREE (id
->fns
, 0);
257 /* We're building a clone; DECL_INITIAL is still
258 error_mark_node, and current_binding_level is the parm
260 insert_block (new_block
);
263 /* Attach this new block after the DECL_INITIAL block for the
264 function into which this block is being inlined. In
265 rest_of_compilation we will straighten out the BLOCK tree. */
267 if (DECL_INITIAL (fn
))
268 first_block
= &BLOCK_CHAIN (DECL_INITIAL (fn
));
270 first_block
= &DECL_INITIAL (fn
);
271 BLOCK_CHAIN (new_block
) = *first_block
;
272 *first_block
= new_block
;
274 /* Remember the remapped block. */
275 splay_tree_insert (id
->decl_map
,
276 (splay_tree_key
) old_block
,
277 (splay_tree_value
) new_block
);
279 /* If this is the end of a scope, set the SCOPE_STMT_BLOCK to be the
281 else if (SCOPE_END_P (scope_stmt
) && SCOPE_STMT_BLOCK (scope_stmt
))
285 /* Find this block in the table of remapped things. */
286 n
= splay_tree_lookup (id
->decl_map
,
287 (splay_tree_key
) SCOPE_STMT_BLOCK (scope_stmt
));
290 SCOPE_STMT_BLOCK (scope_stmt
) = (tree
) n
->value
;
294 /* Copy the SCOPE_STMT pointed to by TP. */
297 copy_scope_stmt (tp
, walk_subtrees
, id
)
304 /* Remember whether or not this statement was nullified. When
305 making a copy, copy_tree_r always sets SCOPE_NULLIFIED_P (and
306 doesn't copy the SCOPE_STMT_BLOCK) to free callers from having to
307 deal with copying BLOCKs if they do not wish to do so. */
308 block
= SCOPE_STMT_BLOCK (*tp
);
309 /* Copy (and replace) the statement. */
310 copy_tree_r (tp
, walk_subtrees
, NULL
);
311 /* Restore the SCOPE_STMT_BLOCK. */
312 SCOPE_STMT_BLOCK (*tp
) = block
;
314 /* Remap the associated block. */
315 remap_block (*tp
, NULL_TREE
, id
);
318 /* Called from copy_body via walk_tree. DATA is really an
322 copy_body_r (tp
, walk_subtrees
, data
)
331 id
= (inline_data
*) data
;
332 fn
= VARRAY_TOP_TREE (id
->fns
);
335 /* All automatic variables should have a DECL_CONTEXT indicating
336 what function they come from. */
337 if ((TREE_CODE (*tp
) == VAR_DECL
|| TREE_CODE (*tp
) == LABEL_DECL
)
338 && DECL_NAMESPACE_SCOPE_P (*tp
))
339 if (! DECL_EXTERNAL (*tp
) && ! TREE_STATIC (*tp
))
343 /* If this is a RETURN_STMT, change it into an EXPR_STMT and a
344 GOTO_STMT with the RET_LABEL as its target. */
345 if (TREE_CODE (*tp
) == RETURN_STMT
&& id
->ret_label
)
347 tree return_stmt
= *tp
;
350 /* Build the GOTO_STMT. */
351 goto_stmt
= build_stmt (GOTO_STMT
, id
->ret_label
);
352 TREE_CHAIN (goto_stmt
) = TREE_CHAIN (return_stmt
);
353 GOTO_FAKE_P (goto_stmt
) = 1;
355 /* If we're returning something, just turn that into an
356 assignment into the equivalent of the original
358 if (RETURN_EXPR (return_stmt
))
360 *tp
= build_stmt (EXPR_STMT
,
361 RETURN_EXPR (return_stmt
));
362 STMT_IS_FULL_EXPR_P (*tp
) = 1;
363 /* And then jump to the end of the function. */
364 TREE_CHAIN (*tp
) = goto_stmt
;
366 /* If we're not returning anything just do the jump. */
370 /* Local variables and labels need to be replaced by equivalent
371 variables. We don't want to copy static variables; there's only
372 one of those, no matter how many times we inline the containing
374 else if ((*lang_hooks
.tree_inlining
.auto_var_in_fn_p
) (*tp
, fn
))
378 /* Remap the declaration. */
379 new_decl
= remap_decl (*tp
, id
);
382 /* Replace this variable with the copy. */
383 STRIP_TYPE_NOPS (new_decl
);
387 else if (nonstatic_local_decl_p (*tp
)
388 && DECL_CONTEXT (*tp
) != VARRAY_TREE (id
->fns
, 0))
391 else if (TREE_CODE (*tp
) == SAVE_EXPR
)
392 remap_save_expr (tp
, id
->decl_map
, VARRAY_TREE (id
->fns
, 0),
394 else if (TREE_CODE (*tp
) == UNSAVE_EXPR
)
395 /* UNSAVE_EXPRs should not be generated until expansion time. */
397 /* For a SCOPE_STMT, we must copy the associated block so that we
398 can write out debugging information for the inlined variables. */
399 else if (TREE_CODE (*tp
) == SCOPE_STMT
&& !id
->in_target_cleanup_p
)
400 copy_scope_stmt (tp
, walk_subtrees
, id
);
401 /* Otherwise, just copy the node. Note that copy_tree_r already
402 knows not to copy VAR_DECLs, etc., so this is safe. */
405 copy_tree_r (tp
, walk_subtrees
, NULL
);
407 /* The copied TARGET_EXPR has never been expanded, even if the
408 original node was expanded already. */
409 if (TREE_CODE (*tp
) == TARGET_EXPR
&& TREE_OPERAND (*tp
, 3))
411 TREE_OPERAND (*tp
, 1) = TREE_OPERAND (*tp
, 3);
412 TREE_OPERAND (*tp
, 3) = NULL_TREE
;
414 else if (TREE_CODE (*tp
) == MODIFY_EXPR
415 && TREE_OPERAND (*tp
, 0) == TREE_OPERAND (*tp
, 1)
416 && ((*lang_hooks
.tree_inlining
.auto_var_in_fn_p
)
417 (TREE_OPERAND (*tp
, 0), fn
)))
419 /* Some assignments VAR = VAR; don't generate any rtl code
420 and thus don't count as variable modification. Avoid
421 keeping bogosities like 0 = 0. */
422 tree decl
= TREE_OPERAND (*tp
, 0), value
;
425 n
= splay_tree_lookup (id
->decl_map
, (splay_tree_key
) decl
);
428 value
= (tree
) n
->value
;
429 STRIP_TYPE_NOPS (value
);
430 if (TREE_CONSTANT (value
) || TREE_READONLY_DECL_P (value
))
436 /* Keep iterating. */
440 /* Make a copy of the body of FN so that it can be inserted inline in
449 body
= DECL_SAVED_TREE (VARRAY_TOP_TREE (id
->fns
));
450 walk_tree (&body
, copy_body_r
, id
, NULL
);
455 /* Generate code to initialize the parameters of the function at the
456 top of the stack in ID from the ARGS (presented as a TREE_LIST). */
459 initialize_inlined_parameters (id
, args
, fn
)
469 /* Figure out what the parameters are. */
470 parms
= DECL_ARGUMENTS (fn
);
472 /* Start with no initializations whatsoever. */
473 init_stmts
= NULL_TREE
;
475 /* Loop through the parameter declarations, replacing each with an
476 equivalent VAR_DECL, appropriately initialized. */
477 for (p
= parms
, a
= args
; p
;
478 a
= a
? TREE_CHAIN (a
) : a
, p
= TREE_CHAIN (p
))
484 /* Find the initializer. */
485 value
= a
? TREE_VALUE (a
) : NULL_TREE
;
487 /* If the parameter is never assigned to, we may not need to
488 create a new variable here at all. Instead, we may be able
489 to just use the argument value. */
490 if (TREE_READONLY (p
)
491 && !TREE_ADDRESSABLE (p
)
492 && value
&& !TREE_SIDE_EFFECTS (value
))
494 /* Simplify the value, if possible. */
495 value
= fold (DECL_P (value
) ? decl_constant_value (value
) : value
);
497 /* We can't risk substituting complex expressions. They
498 might contain variables that will be assigned to later.
499 Theoretically, we could check the expression to see if
500 all of the variables that determine its value are
501 read-only, but we don't bother. */
502 if (TREE_CONSTANT (value
) || TREE_READONLY_DECL_P (value
))
504 /* If this is a declaration, wrap it a NOP_EXPR so that
505 we don't try to put the VALUE on the list of
508 value
= build1 (NOP_EXPR
, TREE_TYPE (value
), value
);
510 splay_tree_insert (id
->decl_map
,
512 (splay_tree_value
) value
);
517 /* Make an equivalent VAR_DECL. */
518 var
= copy_decl_for_inlining (p
, fn
, VARRAY_TREE (id
->fns
, 0));
519 /* Register the VAR_DECL as the equivalent for the PARM_DECL;
520 that way, when the PARM_DECL is encountered, it will be
521 automatically replaced by the VAR_DECL. */
522 splay_tree_insert (id
->decl_map
,
524 (splay_tree_value
) var
);
526 /* Declare this new variable. */
527 init_stmt
= build_stmt (DECL_STMT
, var
);
528 TREE_CHAIN (init_stmt
) = init_stmts
;
529 init_stmts
= init_stmt
;
531 /* Initialize this VAR_DECL from the equivalent argument. If
532 the argument is an object, created via a constructor or copy,
533 this will not result in an extra copy: the TARGET_EXPR
534 representing the argument will be bound to VAR, and the
535 object will be constructed in VAR. */
536 if (! TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (p
)))
537 DECL_INITIAL (var
) = value
;
540 /* Even if P was TREE_READONLY, the new VAR should not be.
541 In the original code, we would have constructed a
542 temporary, and then the function body would have never
543 changed the value of P. However, now, we will be
544 constructing VAR directly. The constructor body may
545 change its value multiple times as it is being
546 constructed. Therefore, it must not be TREE_READONLY;
547 the back-end assumes that TREE_READONLY variable is
548 assigned to only once. */
549 TREE_READONLY (var
) = 0;
551 /* Build a run-time initialization. */
552 init_stmt
= build_stmt (EXPR_STMT
,
553 build (INIT_EXPR
, TREE_TYPE (p
),
555 /* Add this initialization to the list. Note that we want the
556 declaration *after* the initialization because we are going
557 to reverse all the initialization statements below. */
558 TREE_CHAIN (init_stmt
) = init_stmts
;
559 init_stmts
= init_stmt
;
563 /* Evaluate trailing arguments. */
564 for (; a
; a
= TREE_CHAIN (a
))
569 /* Find the initializer. */
570 value
= a
? TREE_VALUE (a
) : NULL_TREE
;
572 if (! value
|| ! TREE_SIDE_EFFECTS (value
))
575 init_stmt
= build_stmt (EXPR_STMT
, value
);
576 TREE_CHAIN (init_stmt
) = init_stmts
;
577 init_stmts
= init_stmt
;
580 /* The initialization statements have been built up in reverse
581 order. Straighten them out now. */
582 return nreverse (init_stmts
);
585 /* Declare a return variable to replace the RESULT_DECL for the
586 function we are calling. An appropriate DECL_STMT is returned.
587 The USE_STMT is filled in to contain a use of the declaration to
588 indicate the return value of the function. */
591 declare_return_variable (id
, use_stmt
)
592 struct inline_data
*id
;
595 tree fn
= VARRAY_TOP_TREE (id
->fns
);
596 tree result
= DECL_RESULT (fn
);
598 int need_return_decl
= 1;
600 /* We don't need to do anything for functions that don't return
602 if (!result
|| VOID_TYPE_P (TREE_TYPE (result
)))
604 *use_stmt
= NULL_TREE
;
608 var
= ((*lang_hooks
.tree_inlining
.copy_res_decl_for_inlining
)
609 (result
, fn
, VARRAY_TREE (id
->fns
, 0), id
->decl_map
,
610 &need_return_decl
, &id
->target_exprs
));
612 /* Register the VAR_DECL as the equivalent for the RESULT_DECL; that
613 way, when the RESULT_DECL is encountered, it will be
614 automatically replaced by the VAR_DECL. */
615 splay_tree_insert (id
->decl_map
,
616 (splay_tree_key
) result
,
617 (splay_tree_value
) var
);
619 /* Build the USE_STMT. If the return type of the function was
620 promoted, convert it back to the expected type. */
621 if (TREE_TYPE (var
) == TREE_TYPE (TREE_TYPE (fn
)))
622 *use_stmt
= build_stmt (EXPR_STMT
, var
);
624 *use_stmt
= build_stmt (EXPR_STMT
,
625 build1 (NOP_EXPR
, TREE_TYPE (TREE_TYPE (fn
)),
628 /* Build the declaration statement if FN does not return an
630 if (need_return_decl
)
631 return build_stmt (DECL_STMT
, var
);
632 /* If FN does return an aggregate, there's no need to declare the
633 return variable; we're using a variable in our caller's frame. */
638 /* Returns non-zero if a function can be inlined as a tree. */
641 tree_inlinable_function_p (fn
)
644 return inlinable_function_p (fn
, NULL
);
647 /* Returns non-zero if FN is a function that can be inlined into the
648 inlining context ID_. If ID_ is NULL, check whether the function
649 can be inlined at all. */
652 inlinable_function_p (fn
, id
)
658 /* If we've already decided this function shouldn't be inlined,
659 there's no need to check again. */
660 if (DECL_UNINLINABLE (fn
))
663 /* Assume it is not inlinable. */
666 /* If we're not inlining things, then nothing is inlinable. */
667 if (! flag_inline_trees
)
669 /* If we're not inlining all functions and the function was not
670 declared `inline', we don't inline it. Don't think of
671 disregarding DECL_INLINE when flag_inline_trees == 2; it's the
672 front-end that must set DECL_INLINE in this case, because
673 dwarf2out loses if a function is inlined that doesn't have
675 else if (! DECL_INLINE (fn
))
677 /* We can't inline functions that are too big. Only allow a single
678 function to eat up half of our budget. Make special allowance
679 for extern inline functions, though. */
680 else if (! (*lang_hooks
.tree_inlining
.disregard_inline_limits
) (fn
)
681 && DECL_NUM_STMTS (fn
) * INSNS_PER_STMT
> MAX_INLINE_INSNS
/ 2)
683 /* All is well. We can inline this function. Traditionally, GCC
684 has refused to inline functions using alloca, or functions whose
685 values are returned in a PARALLEL, and a few other such obscure
686 conditions. We are not equally constrained at the tree level. */
690 /* Squirrel away the result so that we don't have to check again. */
691 DECL_UNINLINABLE (fn
) = ! inlinable
;
693 /* Even if this function is not itself too big to inline, it might
694 be that we've done so much inlining already that we don't want to
695 risk too much inlining any more and thus halve the acceptable
697 if (! (*lang_hooks
.tree_inlining
.disregard_inline_limits
) (fn
)
698 && ((DECL_NUM_STMTS (fn
) + (id
? id
->inlined_stmts
: 0)) * INSNS_PER_STMT
700 && DECL_NUM_STMTS (fn
) * INSNS_PER_STMT
> MAX_INLINE_INSNS
/ 4)
703 if (inlinable
&& (*lang_hooks
.tree_inlining
.cannot_inline_tree_fn
) (&fn
))
706 /* If we don't have the function body available, we can't inline
708 if (! DECL_SAVED_TREE (fn
))
711 /* Check again, language hooks may have modified it. */
712 if (! inlinable
|| DECL_UNINLINABLE (fn
))
715 /* Don't do recursive inlining, either. We don't record this in
716 DECL_UNINLINABLE; we may be able to inline this function later. */
721 for (i
= 0; i
< VARRAY_ACTIVE_SIZE (id
->fns
); ++i
)
722 if (VARRAY_TREE (id
->fns
, i
) == fn
)
725 if (DECL_INLINED_FNS (fn
))
728 tree inlined_fns
= DECL_INLINED_FNS (fn
);
730 for (j
= 0; j
< TREE_VEC_LENGTH (inlined_fns
); ++j
)
731 if (TREE_VEC_ELT (inlined_fns
, j
) == VARRAY_TREE (id
->fns
, 0))
736 /* Return the result. */
740 /* If *TP is a CALL_EXPR, replace it with its inline expansion. */
743 expand_call_inline (tp
, walk_subtrees
, data
)
759 /* See what we've got. */
760 id
= (inline_data
*) data
;
763 /* Recurse, but letting recursive invocations know that we are
764 inside the body of a TARGET_EXPR. */
765 if (TREE_CODE (*tp
) == TARGET_EXPR
)
767 int i
, len
= first_rtl_op (TARGET_EXPR
);
769 /* We're walking our own subtrees. */
772 /* Push *TP on the stack of pending TARGET_EXPRs. */
773 VARRAY_PUSH_TREE (id
->target_exprs
, *tp
);
775 /* Actually walk over them. This loop is the body of
776 walk_trees, omitting the case where the TARGET_EXPR
777 itself is handled. */
778 for (i
= 0; i
< len
; ++i
)
781 ++id
->in_target_cleanup_p
;
782 walk_tree (&TREE_OPERAND (*tp
, i
), expand_call_inline
, data
,
785 --id
->in_target_cleanup_p
;
788 /* We're done with this TARGET_EXPR now. */
789 VARRAY_POP (id
->target_exprs
);
795 /* Because types were not copied in copy_body, CALL_EXPRs beneath
796 them should not be expanded. This can happen if the type is a
797 dynamic array type, for example. */
800 /* From here on, we're only interested in CALL_EXPRs. */
801 if (TREE_CODE (t
) != CALL_EXPR
)
804 /* First, see if we can figure out what function is being called.
805 If we cannot, then there is no hope of inlining the function. */
806 fn
= get_callee_fndecl (t
);
810 /* If fn is a declaration of a function in a nested scope that was
811 globally declared inline, we don't set its DECL_INITIAL.
812 However, we can't blindly follow DECL_ABSTRACT_ORIGIN because the
813 C++ front-end uses it for cdtors to refer to their internal
814 declarations, that are not real functions. Fortunately those
815 don't have trees to be saved, so we can tell by checking their
817 if (! DECL_INITIAL (fn
)
818 && DECL_ABSTRACT_ORIGIN (fn
)
819 && DECL_SAVED_TREE (DECL_ABSTRACT_ORIGIN (fn
)))
820 fn
= DECL_ABSTRACT_ORIGIN (fn
);
822 /* Don't try to inline functions that are not well-suited to
824 if (!inlinable_function_p (fn
, id
))
827 if (! (*lang_hooks
.tree_inlining
.start_inlining
) (fn
))
830 /* Set the current filename and line number to the function we are
831 inlining so that when we create new _STMT nodes here they get
832 line numbers corresponding to the function we are calling. We
833 wrap the whole inlined body in an EXPR_WITH_FILE_AND_LINE as well
834 because individual statements don't record the filename. */
835 push_srcloc (fn
->decl
.filename
, fn
->decl
.linenum
);
837 /* Build a statement-expression containing code to initialize the
838 arguments, the actual inline expansion of the body, and a label
839 for the return statements within the function to jump to. The
840 type of the statement expression is the return type of the
842 expr
= build1 (STMT_EXPR
, TREE_TYPE (TREE_TYPE (fn
)), NULL_TREE
);
844 /* Local declarations will be replaced by their equivalents in this
847 id
->decl_map
= splay_tree_new (splay_tree_compare_pointers
,
850 /* Initialize the parameters. */
851 arg_inits
= initialize_inlined_parameters (id
, TREE_OPERAND (t
, 1), fn
);
852 /* Expand any inlined calls in the initializers. Do this before we
853 push FN on the stack of functions we are inlining; we want to
854 inline calls to FN that appear in the initializers for the
856 expand_calls_inline (&arg_inits
, id
);
857 /* And add them to the tree. */
858 STMT_EXPR_STMT (expr
) = chainon (STMT_EXPR_STMT (expr
), arg_inits
);
860 /* Record the function we are about to inline so that we can avoid
861 recursing into it. */
862 VARRAY_PUSH_TREE (id
->fns
, fn
);
864 /* Record the function we are about to inline if optimize_function
865 has not been called on it yet and we don't have it in the list. */
866 if (! DECL_INLINED_FNS (fn
))
870 for (i
= VARRAY_ACTIVE_SIZE (id
->inlined_fns
) - 1; i
>= 0; i
--)
871 if (VARRAY_TREE (id
->inlined_fns
, i
) == fn
)
874 VARRAY_PUSH_TREE (id
->inlined_fns
, fn
);
877 /* Return statements in the function body will be replaced by jumps
879 id
->ret_label
= build_decl (LABEL_DECL
, NULL_TREE
, NULL_TREE
);
880 DECL_CONTEXT (id
->ret_label
) = VARRAY_TREE (id
->fns
, 0);
882 if (! DECL_INITIAL (fn
)
883 || TREE_CODE (DECL_INITIAL (fn
)) != BLOCK
)
886 /* Create a block to put the parameters in. We have to do this
887 after the parameters have been remapped because remapping
888 parameters is different from remapping ordinary variables. */
889 scope_stmt
= build_stmt (SCOPE_STMT
, DECL_INITIAL (fn
));
890 SCOPE_BEGIN_P (scope_stmt
) = 1;
891 SCOPE_NO_CLEANUPS_P (scope_stmt
) = 1;
892 remap_block (scope_stmt
, DECL_ARGUMENTS (fn
), id
);
893 TREE_CHAIN (scope_stmt
) = STMT_EXPR_STMT (expr
);
894 STMT_EXPR_STMT (expr
) = scope_stmt
;
896 /* Tell the debugging backends that this block represents the
897 outermost scope of the inlined function. */
898 if (SCOPE_STMT_BLOCK (scope_stmt
))
899 BLOCK_ABSTRACT_ORIGIN (SCOPE_STMT_BLOCK (scope_stmt
)) = DECL_ORIGIN (fn
);
901 /* Declare the return variable for the function. */
902 STMT_EXPR_STMT (expr
)
903 = chainon (STMT_EXPR_STMT (expr
),
904 declare_return_variable (id
, &use_stmt
));
906 /* After we've initialized the parameters, we insert the body of the
908 inlined_body
= &STMT_EXPR_STMT (expr
);
909 while (*inlined_body
)
910 inlined_body
= &TREE_CHAIN (*inlined_body
);
911 *inlined_body
= copy_body (id
);
913 /* Close the block for the parameters. */
914 scope_stmt
= build_stmt (SCOPE_STMT
, DECL_INITIAL (fn
));
915 SCOPE_NO_CLEANUPS_P (scope_stmt
) = 1;
916 remap_block (scope_stmt
, NULL_TREE
, id
);
917 STMT_EXPR_STMT (expr
)
918 = chainon (STMT_EXPR_STMT (expr
), scope_stmt
);
920 /* After the body of the function comes the RET_LABEL. This must come
921 before we evaluate the returned value below, because that evalulation
922 may cause RTL to be generated. */
923 STMT_EXPR_STMT (expr
)
924 = chainon (STMT_EXPR_STMT (expr
),
925 build_stmt (LABEL_STMT
, id
->ret_label
));
927 /* Finally, mention the returned value so that the value of the
928 statement-expression is the returned value of the function. */
929 STMT_EXPR_STMT (expr
) = chainon (STMT_EXPR_STMT (expr
), use_stmt
);
932 splay_tree_delete (id
->decl_map
);
935 /* The new expression has side-effects if the old one did. */
936 TREE_SIDE_EFFECTS (expr
) = TREE_SIDE_EFFECTS (t
);
938 /* Replace the call by the inlined body. Wrap it in an
939 EXPR_WITH_FILE_LOCATION so that we'll get debugging line notes
940 pointing to the right place. */
941 chain
= TREE_CHAIN (*tp
);
942 *tp
= build_expr_wfl (expr
, DECL_SOURCE_FILE (fn
), DECL_SOURCE_LINE (fn
),
944 EXPR_WFL_EMIT_LINE_NOTE (*tp
) = 1;
945 TREE_CHAIN (*tp
) = chain
;
948 /* If the value of the new expression is ignored, that's OK. We
949 don't warn about this for CALL_EXPRs, so we shouldn't warn about
950 the equivalent inlined version either. */
953 /* Our function now has more statements than it did before. */
954 DECL_NUM_STMTS (VARRAY_TREE (id
->fns
, 0)) += DECL_NUM_STMTS (fn
);
955 id
->inlined_stmts
+= DECL_NUM_STMTS (fn
);
957 /* Recurse into the body of the just inlined function. */
958 expand_calls_inline (inlined_body
, id
);
959 VARRAY_POP (id
->fns
);
961 /* If we've returned to the top level, clear out the record of how
962 much inlining has been done. */
963 if (VARRAY_ACTIVE_SIZE (id
->fns
) == id
->first_inlined_fn
)
964 id
->inlined_stmts
= 0;
966 /* Don't walk into subtrees. We've already handled them above. */
969 (*lang_hooks
.tree_inlining
.end_inlining
) (fn
);
971 /* Keep iterating. */
975 /* Walk over the entire tree *TP, replacing CALL_EXPRs with inline
976 expansions as appropriate. */
979 expand_calls_inline (tp
, id
)
983 /* Search through *TP, replacing all calls to inline functions by
984 appropriate equivalents. Use walk_tree in no-duplicates mode
985 to avoid exponential time complexity. (We can't just use
986 walk_tree_without_duplicates, because of the special TARGET_EXPR
987 handling in expand_calls. The hash table is set up in
988 optimize_function. */
989 walk_tree (tp
, expand_call_inline
, id
, id
->tree_pruner
);
992 /* Expand calls to inline functions in the body of FN. */
995 optimize_inline_calls (fn
)
1002 memset (&id
, 0, sizeof (id
));
1004 /* Don't allow recursion into FN. */
1005 VARRAY_TREE_INIT (id
.fns
, 32, "fns");
1006 VARRAY_PUSH_TREE (id
.fns
, fn
);
1007 /* Or any functions that aren't finished yet. */
1008 prev_fn
= NULL_TREE
;
1009 if (current_function_decl
)
1011 VARRAY_PUSH_TREE (id
.fns
, current_function_decl
);
1012 prev_fn
= current_function_decl
;
1015 prev_fn
= ((*lang_hooks
.tree_inlining
.add_pending_fn_decls
)
1016 (&id
.fns
, prev_fn
));
1018 /* Create the stack of TARGET_EXPRs. */
1019 VARRAY_TREE_INIT (id
.target_exprs
, 32, "target_exprs");
1021 /* Create the list of functions this call will inline. */
1022 VARRAY_TREE_INIT (id
.inlined_fns
, 32, "inlined_fns");
1024 /* Keep track of the low-water mark, i.e., the point where the first
1025 real inlining is represented in ID.FNS. */
1026 id
.first_inlined_fn
= VARRAY_ACTIVE_SIZE (id
.fns
);
1028 /* Replace all calls to inline functions with the bodies of those
1030 id
.tree_pruner
= htab_create (37, htab_hash_pointer
,
1031 htab_eq_pointer
, NULL
);
1032 expand_calls_inline (&DECL_SAVED_TREE (fn
), &id
);
1035 htab_delete (id
.tree_pruner
);
1036 VARRAY_FREE (id
.fns
);
1037 VARRAY_FREE (id
.target_exprs
);
1038 if (DECL_LANG_SPECIFIC (fn
))
1040 tree ifn
= make_tree_vec (VARRAY_ACTIVE_SIZE (id
.inlined_fns
));
1042 memcpy (&TREE_VEC_ELT (ifn
, 0), &VARRAY_TREE (id
.inlined_fns
, 0),
1043 VARRAY_ACTIVE_SIZE (id
.inlined_fns
) * sizeof (tree
));
1044 DECL_INLINED_FNS (fn
) = ifn
;
1046 VARRAY_FREE (id
.inlined_fns
);
1049 /* FN is a function that has a complete body, and CLONE is a function
1050 whose body is to be set to a copy of FN, mapping argument
1051 declarations according to the ARG_MAP splay_tree. */
1054 clone_body (clone
, fn
, arg_map
)
1060 /* Clone the body, as if we were making an inline call. But, remap
1061 the parameters in the callee to the parameters of caller. If
1062 there's an in-charge parameter, map it to an appropriate
1064 memset (&id
, 0, sizeof (id
));
1065 VARRAY_TREE_INIT (id
.fns
, 2, "fns");
1066 VARRAY_PUSH_TREE (id
.fns
, clone
);
1067 VARRAY_PUSH_TREE (id
.fns
, fn
);
1068 id
.decl_map
= (splay_tree
)arg_map
;
1070 /* Cloning is treated slightly differently from inlining. Set
1071 CLONING_P so that it's clear which operation we're performing. */
1072 id
.cloning_p
= true;
1074 /* Actually copy the body. */
1075 TREE_CHAIN (DECL_SAVED_TREE (clone
)) = copy_body (&id
);
1078 VARRAY_FREE (id
.fns
);
1081 /* Apply FUNC to all the sub-trees of TP in a pre-order traversal.
1082 FUNC is called with the DATA and the address of each sub-tree. If
1083 FUNC returns a non-NULL value, the traversal is aborted, and the
1084 value returned by FUNC is returned. If HTAB is non-NULL it is used
1085 to record the nodes visited, and to avoid visiting a node more than
1089 walk_tree (tp
, func
, data
, htab_
)
1095 htab_t htab
= (htab_t
) htab_
;
1096 enum tree_code code
;
1100 #define WALK_SUBTREE(NODE) \
1103 result = walk_tree (&(NODE), func, data, htab); \
1109 #define WALK_SUBTREE_TAIL(NODE) \
1113 goto tail_recurse; \
1118 /* Skip empty subtrees. */
1126 /* Don't walk the same tree twice, if the user has requested
1127 that we avoid doing so. */
1128 if (htab_find (htab
, *tp
))
1130 /* If we haven't already seen this node, add it to the table. */
1131 slot
= htab_find_slot (htab
, *tp
, INSERT
);
1135 /* Call the function. */
1137 result
= (*func
) (tp
, &walk_subtrees
, data
);
1139 /* If we found something, return it. */
1143 code
= TREE_CODE (*tp
);
1145 /* Even if we didn't, FUNC may have decided that there was nothing
1146 interesting below this point in the tree. */
1149 if (statement_code_p (code
) || code
== TREE_LIST
1150 || (*lang_hooks
.tree_inlining
.tree_chain_matters_p
) (*tp
))
1151 /* But we still need to check our siblings. */
1152 WALK_SUBTREE_TAIL (TREE_CHAIN (*tp
));
1157 /* Handle common cases up front. */
1158 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
))
1159 || TREE_CODE_CLASS (code
) == 'r'
1160 || TREE_CODE_CLASS (code
) == 's')
1164 /* Set lineno here so we get the right instantiation context
1165 if we call instantiate_decl from inlinable_function_p. */
1166 if (statement_code_p (code
) && !STMT_LINENO_FOR_FN_P (*tp
))
1167 lineno
= STMT_LINENO (*tp
);
1169 /* Walk over all the sub-trees of this operand. */
1170 len
= first_rtl_op (code
);
1171 /* TARGET_EXPRs are peculiar: operands 1 and 3 can be the same.
1172 But, we only want to walk once. */
1173 if (code
== TARGET_EXPR
1174 && TREE_OPERAND (*tp
, 3) == TREE_OPERAND (*tp
, 1))
1176 /* Go through the subtrees. We need to do this in forward order so
1177 that the scope of a FOR_EXPR is handled properly. */
1178 for (i
= 0; i
< len
; ++i
)
1179 WALK_SUBTREE (TREE_OPERAND (*tp
, i
));
1181 /* For statements, we also walk the chain so that we cover the
1182 entire statement tree. */
1183 if (statement_code_p (code
))
1185 if (code
== DECL_STMT
1186 && DECL_STMT_DECL (*tp
)
1187 && DECL_P (DECL_STMT_DECL (*tp
)))
1189 /* Walk the DECL_INITIAL and DECL_SIZE. We don't want to walk
1190 into declarations that are just mentioned, rather than
1191 declared; they don't really belong to this part of the tree.
1192 And, we can see cycles: the initializer for a declaration can
1193 refer to the declaration itself. */
1194 WALK_SUBTREE (DECL_INITIAL (DECL_STMT_DECL (*tp
)));
1195 WALK_SUBTREE (DECL_SIZE (DECL_STMT_DECL (*tp
)));
1196 WALK_SUBTREE (DECL_SIZE_UNIT (DECL_STMT_DECL (*tp
)));
1199 /* This can be tail-recursion optimized if we write it this way. */
1200 WALK_SUBTREE_TAIL (TREE_CHAIN (*tp
));
1203 /* We didn't find what we were looking for. */
1206 else if (TREE_CODE_CLASS (code
) == 'd')
1208 WALK_SUBTREE_TAIL (TREE_TYPE (*tp
));
1211 result
= (*lang_hooks
.tree_inlining
.walk_subtrees
) (tp
, &walk_subtrees
, func
,
1213 if (result
|| ! walk_subtrees
)
1216 /* Not one of the easy cases. We must explicitly go through the
1221 case IDENTIFIER_NODE
:
1234 /* None of thse have subtrees other than those already walked
1239 case REFERENCE_TYPE
:
1240 WALK_SUBTREE_TAIL (TREE_TYPE (*tp
));
1244 WALK_SUBTREE (TREE_VALUE (*tp
));
1245 WALK_SUBTREE_TAIL (TREE_CHAIN (*tp
));
1250 int len
= TREE_VEC_LENGTH (*tp
);
1255 /* Walk all elements but the first. */
1257 WALK_SUBTREE (TREE_VEC_ELT (*tp
, len
));
1259 /* Now walk the first one as a tail call. */
1260 WALK_SUBTREE_TAIL (TREE_VEC_ELT (*tp
, 0));
1264 WALK_SUBTREE (TREE_REALPART (*tp
));
1265 WALK_SUBTREE_TAIL (TREE_IMAGPART (*tp
));
1268 WALK_SUBTREE_TAIL (CONSTRUCTOR_ELTS (*tp
));
1271 WALK_SUBTREE (TYPE_METHOD_BASETYPE (*tp
));
1275 WALK_SUBTREE (TREE_TYPE (*tp
));
1277 tree arg
= TYPE_ARG_TYPES (*tp
);
1279 /* We never want to walk into default arguments. */
1280 for (; arg
; arg
= TREE_CHAIN (arg
))
1281 WALK_SUBTREE (TREE_VALUE (arg
));
1286 WALK_SUBTREE (TREE_TYPE (*tp
));
1287 WALK_SUBTREE_TAIL (TYPE_DOMAIN (*tp
));
1290 WALK_SUBTREE (TYPE_MIN_VALUE (*tp
));
1291 WALK_SUBTREE_TAIL (TYPE_MAX_VALUE (*tp
));
1294 WALK_SUBTREE (TREE_TYPE (*tp
));
1295 WALK_SUBTREE_TAIL (TYPE_OFFSET_BASETYPE (*tp
));
1301 /* We didn't find what we were looking for. */
1307 /* Like walk_tree, but does not walk duplicate nodes more than
1311 walk_tree_without_duplicates (tp
, func
, data
)
1319 htab
= htab_create (37, htab_hash_pointer
, htab_eq_pointer
, NULL
);
1320 result
= walk_tree (tp
, func
, data
, htab
);
1325 /* Passed to walk_tree. Copies the node pointed to, if appropriate. */
1328 copy_tree_r (tp
, walk_subtrees
, data
)
1331 void *data ATTRIBUTE_UNUSED
;
1333 enum tree_code code
= TREE_CODE (*tp
);
1335 /* We make copies of most nodes. */
1336 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
))
1337 || TREE_CODE_CLASS (code
) == 'r'
1338 || TREE_CODE_CLASS (code
) == 'c'
1339 || TREE_CODE_CLASS (code
) == 's'
1340 || code
== TREE_LIST
1342 || (*lang_hooks
.tree_inlining
.tree_chain_matters_p
) (*tp
))
1344 /* Because the chain gets clobbered when we make a copy, we save it
1346 tree chain
= TREE_CHAIN (*tp
);
1348 /* Copy the node. */
1349 *tp
= copy_node (*tp
);
1351 /* Now, restore the chain, if appropriate. That will cause
1352 walk_tree to walk into the chain as well. */
1353 if (code
== PARM_DECL
|| code
== TREE_LIST
1354 || (*lang_hooks
.tree_inlining
.tree_chain_matters_p
) (*tp
)
1355 || statement_code_p (code
))
1356 TREE_CHAIN (*tp
) = chain
;
1358 /* For now, we don't update BLOCKs when we make copies. So, we
1359 have to nullify all scope-statements. */
1360 if (TREE_CODE (*tp
) == SCOPE_STMT
)
1361 SCOPE_STMT_BLOCK (*tp
) = NULL_TREE
;
1363 else if (TREE_CODE_CLASS (code
) == 't')
1364 /* There's no need to copy types, or anything beneath them. */
1370 /* The SAVE_EXPR pointed to by TP is being copied. If ST contains
1371 information indicating to what new SAVE_EXPR this one should be
1372 mapped, use that one. Otherwise, create a new node and enter it in
1373 ST. FN is the function into which the copy will be placed. */
1376 remap_save_expr (tp
, st_
, fn
, walk_subtrees
)
1382 splay_tree st
= (splay_tree
) st_
;
1385 /* See if we already encountered this SAVE_EXPR. */
1386 n
= splay_tree_lookup (st
, (splay_tree_key
) *tp
);
1388 /* If we didn't already remap this SAVE_EXPR, do so now. */
1391 tree t
= copy_node (*tp
);
1393 /* The SAVE_EXPR is now part of the function into which we
1394 are inlining this body. */
1395 SAVE_EXPR_CONTEXT (t
) = fn
;
1396 /* And we haven't evaluated it yet. */
1397 SAVE_EXPR_RTL (t
) = NULL_RTX
;
1398 /* Remember this SAVE_EXPR. */
1399 n
= splay_tree_insert (st
,
1400 (splay_tree_key
) *tp
,
1401 (splay_tree_value
) t
);
1402 /* Make sure we don't remap an already-remapped SAVE_EXPR. */
1403 splay_tree_insert (st
, (splay_tree_key
) t
,
1404 (splay_tree_value
) error_mark_node
);
1407 /* We've already walked into this SAVE_EXPR, so we needn't do it
1411 /* Replace this SAVE_EXPR with the copy. */
1412 *tp
= (tree
) n
->value
;