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"
38 /* This should be eventually be generalized to other languages, but
39 this would require a shared function-as-trees infrastructure. */
42 /* 0 if we should not perform inlining.
43 1 if we should expand functions calls inline at the tree level.
44 2 if we should consider *all* functions to be inline
47 int flag_inline_trees = 0;
51 o In order to make inlining-on-trees work, we pessimized
52 function-local static constants. In particular, they are now
53 always output, even when not addressed. Fix this by treating
54 function-local static constants just like global static
55 constants; the back-end already knows not to output them if they
58 o Provide heuristics to clamp inlining of recursive template
61 /* Data required for function inlining. */
63 typedef struct inline_data
65 /* A stack of the functions we are inlining. For example, if we are
66 compiling `f', which calls `g', which calls `h', and we are
67 inlining the body of `h', the stack will contain, `h', followed
68 by `g', followed by `f'. The first few elements of the stack may
69 contain other functions that we know we should not recurse into,
70 even though they are not directly being inlined. */
72 /* The index of the first element of FNS that really represents an
74 unsigned first_inlined_fn;
75 /* The label to jump to when a return statement is encountered. If
76 this value is NULL, then return statements will simply be
77 remapped as return statements, rather than as jumps. */
79 /* The map from local declarations in the inlined function to
80 equivalents in the function into which it is being inlined. */
82 /* Nonzero if we are currently within the cleanup for a
84 int in_target_cleanup_p;
85 /* A stack of the TARGET_EXPRs that we are currently processing. */
86 varray_type target_exprs;
87 /* A list of the functions current function has inlined. */
88 varray_type inlined_fns;
89 /* The approximate number of statements we have inlined in the
90 current call stack. */
92 /* We use the same mechanism to build clones that we do to perform
93 inlining. However, there are a few places where we need to
94 distinguish between those two situations. This flag is true if
95 we are cloning, rather than inlining. */
97 /* Hash table used to prevent walk_tree from visiting the same node
98 umpteen million times. */
104 static tree initialize_inlined_parameters PARAMS ((inline_data *, tree, tree));
105 static tree declare_return_variable PARAMS ((inline_data *, tree *));
106 static tree copy_body_r PARAMS ((tree *, int *, void *));
107 static tree copy_body PARAMS ((inline_data *));
108 static tree expand_call_inline PARAMS ((tree *, int *, void *));
109 static void expand_calls_inline PARAMS ((tree *, inline_data *));
110 static int inlinable_function_p PARAMS ((tree, inline_data *));
111 static tree remap_decl PARAMS ((tree, inline_data *));
112 static void remap_block PARAMS ((tree, tree, inline_data *));
113 static void copy_scope_stmt PARAMS ((tree *, int *, inline_data *));
115 /* The approximate number of instructions per statement. This number
116 need not be particularly accurate; it is used only to make
117 decisions about when a function is too big to inline. */
118 #define INSNS_PER_STMT (10)
120 /* Remap DECL during the copying of the BLOCK tree for the function. */
123 remap_decl (decl, id)
130 /* We only remap local variables in the current function. */
131 fn = VARRAY_TOP_TREE (id->fns);
132 if (! (*lang_hooks.tree_inlining.auto_var_in_fn_p) (decl, fn))
135 /* See if we have remapped this declaration. */
136 n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl);
137 /* If we didn't already have an equivalent for this declaration,
143 /* Make a copy of the variable or label. */
144 t = copy_decl_for_inlining (decl, fn,
145 VARRAY_TREE (id->fns, 0));
147 /* The decl T could be a dynamic array or other variable size type,
148 in which case some fields need to be remapped because they may
149 contain SAVE_EXPRs. */
150 walk_tree (&DECL_SIZE (t), copy_body_r, id, NULL);
151 walk_tree (&DECL_SIZE_UNIT (t), copy_body_r, id, NULL);
152 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE
153 && TYPE_DOMAIN (TREE_TYPE (t)))
155 TREE_TYPE (t) = copy_node (TREE_TYPE (t));
156 TYPE_DOMAIN (TREE_TYPE (t))
157 = copy_node (TYPE_DOMAIN (TREE_TYPE (t)));
158 walk_tree (&TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (t))),
159 copy_body_r, id, NULL);
162 if (! DECL_NAME (t) && TREE_TYPE (t)
163 && (*lang_hooks.tree_inlining.anon_aggr_type_p) (TREE_TYPE (t)))
165 /* For a VAR_DECL of anonymous type, we must also copy the
166 member VAR_DECLS here and rechain the
167 DECL_ANON_UNION_ELEMS. */
171 for (src = DECL_ANON_UNION_ELEMS (t); src;
172 src = TREE_CHAIN (src))
174 tree member = remap_decl (TREE_VALUE (src), id);
176 if (TREE_PURPOSE (src))
178 members = tree_cons (NULL, member, members);
180 DECL_ANON_UNION_ELEMS (t) = nreverse (members);
183 /* Remember it, so that if we encounter this local entity
184 again we can reuse this copy. */
185 n = splay_tree_insert (id->decl_map,
186 (splay_tree_key) decl,
187 (splay_tree_value) t);
190 return (tree) n->value;
193 /* Copy the SCOPE_STMT_BLOCK associated with SCOPE_STMT to contain
194 remapped versions of the variables therein. And hook the new block
195 into the block-tree. If non-NULL, the DECLS are declarations to
196 add to use instead of the BLOCK_VARS in the old block. */
199 remap_block (scope_stmt, decls, id)
204 /* We cannot do this in the cleanup for a TARGET_EXPR since we do
205 not know whether or not expand_expr will actually write out the
206 code we put there. If it does not, then we'll have more BLOCKs
207 than block-notes, and things will go awry. At some point, we
208 should make the back-end handle BLOCK notes in a tidier way,
209 without requiring a strict correspondence to the block-tree; then
210 this check can go. */
211 if (id->in_target_cleanup_p)
213 SCOPE_STMT_BLOCK (scope_stmt) = NULL_TREE;
217 /* If this is the beginning of a scope, remap the associated BLOCK. */
218 if (SCOPE_BEGIN_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt))
225 /* Make the new block. */
226 old_block = SCOPE_STMT_BLOCK (scope_stmt);
227 new_block = make_node (BLOCK);
228 TREE_USED (new_block) = TREE_USED (old_block);
229 BLOCK_ABSTRACT_ORIGIN (new_block) = old_block;
230 SCOPE_STMT_BLOCK (scope_stmt) = new_block;
232 /* Remap its variables. */
233 for (old_var = decls ? decls : BLOCK_VARS (old_block);
235 old_var = TREE_CHAIN (old_var))
239 /* Remap the variable. */
240 new_var = remap_decl (old_var, id);
241 /* If we didn't remap this variable, so we can't mess with
242 its TREE_CHAIN. If we remapped this variable to
243 something other than a declaration (say, if we mapped it
244 to a constant), then we must similarly omit any mention
246 if (!new_var || !DECL_P (new_var))
250 TREE_CHAIN (new_var) = BLOCK_VARS (new_block);
251 BLOCK_VARS (new_block) = new_var;
254 /* We put the BLOCK_VARS in reverse order; fix that now. */
255 BLOCK_VARS (new_block) = nreverse (BLOCK_VARS (new_block));
256 fn = VARRAY_TREE (id->fns, 0);
258 /* We're building a clone; DECL_INITIAL is still
259 error_mark_node, and current_binding_level is the parm
261 insert_block (new_block);
264 /* Attach this new block after the DECL_INITIAL block for the
265 function into which this block is being inlined. In
266 rest_of_compilation we will straighten out the BLOCK tree. */
268 if (DECL_INITIAL (fn))
269 first_block = &BLOCK_CHAIN (DECL_INITIAL (fn));
271 first_block = &DECL_INITIAL (fn);
272 BLOCK_CHAIN (new_block) = *first_block;
273 *first_block = new_block;
275 /* Remember the remapped block. */
276 splay_tree_insert (id->decl_map,
277 (splay_tree_key) old_block,
278 (splay_tree_value) new_block);
280 /* If this is the end of a scope, set the SCOPE_STMT_BLOCK to be the
282 else if (SCOPE_END_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt))
286 /* Find this block in the table of remapped things. */
287 n = splay_tree_lookup (id->decl_map,
288 (splay_tree_key) SCOPE_STMT_BLOCK (scope_stmt));
291 SCOPE_STMT_BLOCK (scope_stmt) = (tree) n->value;
295 /* Copy the SCOPE_STMT pointed to by TP. */
298 copy_scope_stmt (tp, walk_subtrees, id)
305 /* Remember whether or not this statement was nullified. When
306 making a copy, copy_tree_r always sets SCOPE_NULLIFIED_P (and
307 doesn't copy the SCOPE_STMT_BLOCK) to free callers from having to
308 deal with copying BLOCKs if they do not wish to do so. */
309 block = SCOPE_STMT_BLOCK (*tp);
310 /* Copy (and replace) the statement. */
311 copy_tree_r (tp, walk_subtrees, NULL);
312 /* Restore the SCOPE_STMT_BLOCK. */
313 SCOPE_STMT_BLOCK (*tp) = block;
315 /* Remap the associated block. */
316 remap_block (*tp, NULL_TREE, id);
319 /* Called from copy_body via walk_tree. DATA is really an
323 copy_body_r (tp, walk_subtrees, data)
332 id = (inline_data *) data;
333 fn = VARRAY_TOP_TREE (id->fns);
336 /* All automatic variables should have a DECL_CONTEXT indicating
337 what function they come from. */
338 if ((TREE_CODE (*tp) == VAR_DECL || TREE_CODE (*tp) == LABEL_DECL)
339 && DECL_NAMESPACE_SCOPE_P (*tp))
340 if (! DECL_EXTERNAL (*tp) && ! TREE_STATIC (*tp))
344 /* If this is a RETURN_STMT, change it into an EXPR_STMT and a
345 GOTO_STMT with the RET_LABEL as its target. */
346 if (TREE_CODE (*tp) == RETURN_STMT && id->ret_label)
348 tree return_stmt = *tp;
351 /* Build the GOTO_STMT. */
352 goto_stmt = build_stmt (GOTO_STMT, id->ret_label);
353 TREE_CHAIN (goto_stmt) = TREE_CHAIN (return_stmt);
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. */
671 else if (flag_inline_trees < 2 && ! DECL_INLINE (fn))
673 /* We can't inline functions that are too big. Only allow a single
674 function to eat up half of our budget. Make special allowance
675 for extern inline functions, though. */
676 else if (! (*lang_hooks.tree_inlining.disregard_inline_limits) (fn)
677 && DECL_NUM_STMTS (fn) * INSNS_PER_STMT > MAX_INLINE_INSNS / 2)
679 /* All is well. We can inline this function. Traditionally, GCC
680 has refused to inline functions using alloca, or functions whose
681 values are returned in a PARALLEL, and a few other such obscure
682 conditions. We are not equally constrained at the tree level. */
686 /* Squirrel away the result so that we don't have to check again. */
687 DECL_UNINLINABLE (fn) = ! inlinable;
689 /* Even if this function is not itself too big to inline, it might
690 be that we've done so much inlining already that we don't want to
691 risk too much inlining any more and thus halve the acceptable
693 if (! (*lang_hooks.tree_inlining.disregard_inline_limits) (fn)
694 && ((DECL_NUM_STMTS (fn) + (id ? id->inlined_stmts : 0)) * INSNS_PER_STMT
696 && DECL_NUM_STMTS (fn) * INSNS_PER_STMT > MAX_INLINE_INSNS / 4)
699 if (inlinable && (*lang_hooks.tree_inlining.cannot_inline_tree_fn) (&fn))
702 /* If we don't have the function body available, we can't inline
704 if (! DECL_SAVED_TREE (fn))
707 /* Check again, language hooks may have modified it. */
708 if (! inlinable || DECL_UNINLINABLE (fn))
711 /* Don't do recursive inlining, either. We don't record this in
712 DECL_UNINLINABLE; we may be able to inline this function later. */
717 for (i = 0; i < VARRAY_ACTIVE_SIZE (id->fns); ++i)
718 if (VARRAY_TREE (id->fns, i) == fn)
721 if (DECL_INLINED_FNS (fn))
724 tree inlined_fns = DECL_INLINED_FNS (fn);
726 for (j = 0; j < TREE_VEC_LENGTH (inlined_fns); ++j)
727 if (TREE_VEC_ELT (inlined_fns, j) == VARRAY_TREE (id->fns, 0))
732 /* Return the result. */
736 /* If *TP is a CALL_EXPR, replace it with its inline expansion. */
739 expand_call_inline (tp, walk_subtrees, data)
755 /* See what we've got. */
756 id = (inline_data *) data;
759 /* Recurse, but letting recursive invocations know that we are
760 inside the body of a TARGET_EXPR. */
761 if (TREE_CODE (*tp) == TARGET_EXPR)
763 int i, len = first_rtl_op (TARGET_EXPR);
765 /* We're walking our own subtrees. */
768 /* Push *TP on the stack of pending TARGET_EXPRs. */
769 VARRAY_PUSH_TREE (id->target_exprs, *tp);
771 /* Actually walk over them. This loop is the body of
772 walk_trees, omitting the case where the TARGET_EXPR
773 itself is handled. */
774 for (i = 0; i < len; ++i)
777 ++id->in_target_cleanup_p;
778 walk_tree (&TREE_OPERAND (*tp, i), expand_call_inline, data,
781 --id->in_target_cleanup_p;
784 /* We're done with this TARGET_EXPR now. */
785 VARRAY_POP (id->target_exprs);
791 /* Because types were not copied in copy_body, CALL_EXPRs beneath
792 them should not be expanded. This can happen if the type is a
793 dynamic array type, for example. */
796 /* From here on, we're only interested in CALL_EXPRs. */
797 if (TREE_CODE (t) != CALL_EXPR)
800 /* First, see if we can figure out what function is being called.
801 If we cannot, then there is no hope of inlining the function. */
802 fn = get_callee_fndecl (t);
806 /* Don't try to inline functions that are not well-suited to
808 if (!inlinable_function_p (fn, id))
811 /* Set the current filename and line number to the function we are
812 inlining so that when we create new _STMT nodes here they get
813 line numbers corresponding to the function we are calling. We
814 wrap the whole inlined body in an EXPR_WITH_FILE_AND_LINE as well
815 because individual statements don't record the filename. */
816 push_srcloc (fn->decl.filename, fn->decl.linenum);
818 /* Build a statement-expression containing code to initialize the
819 arguments, the actual inline expansion of the body, and a label
820 for the return statements within the function to jump to. The
821 type of the statement expression is the return type of the
823 expr = build1 (STMT_EXPR, TREE_TYPE (TREE_TYPE (fn)), NULL_TREE);
825 /* Local declarations will be replaced by their equivalents in this
828 id->decl_map = splay_tree_new (splay_tree_compare_pointers,
831 /* Initialize the parameters. */
832 arg_inits = initialize_inlined_parameters (id, TREE_OPERAND (t, 1), fn);
833 /* Expand any inlined calls in the initializers. Do this before we
834 push FN on the stack of functions we are inlining; we want to
835 inline calls to FN that appear in the initializers for the
837 expand_calls_inline (&arg_inits, id);
838 /* And add them to the tree. */
839 STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), arg_inits);
841 /* Record the function we are about to inline so that we can avoid
842 recursing into it. */
843 VARRAY_PUSH_TREE (id->fns, fn);
845 /* Record the function we are about to inline if optimize_function
846 has not been called on it yet and we don't have it in the list. */
847 if (! DECL_INLINED_FNS (fn))
851 for (i = VARRAY_ACTIVE_SIZE (id->inlined_fns) - 1; i >= 0; i--)
852 if (VARRAY_TREE (id->inlined_fns, i) == fn)
855 VARRAY_PUSH_TREE (id->inlined_fns, fn);
858 /* Return statements in the function body will be replaced by jumps
860 id->ret_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
861 DECL_CONTEXT (id->ret_label) = VARRAY_TREE (id->fns, 0);
863 /* Create a block to put the parameters in. We have to do this
864 after the parameters have been remapped because remapping
865 parameters is different from remapping ordinary variables. */
866 scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
867 SCOPE_BEGIN_P (scope_stmt) = 1;
868 SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
869 remap_block (scope_stmt, DECL_ARGUMENTS (fn), id);
870 TREE_CHAIN (scope_stmt) = STMT_EXPR_STMT (expr);
871 STMT_EXPR_STMT (expr) = scope_stmt;
873 /* Tell the debugging backends that this block represents the
874 outermost scope of the inlined function. */
875 if (SCOPE_STMT_BLOCK (scope_stmt))
876 BLOCK_ABSTRACT_ORIGIN (SCOPE_STMT_BLOCK (scope_stmt)) = DECL_ORIGIN (fn);
878 /* Declare the return variable for the function. */
879 STMT_EXPR_STMT (expr)
880 = chainon (STMT_EXPR_STMT (expr),
881 declare_return_variable (id, &use_stmt));
883 /* After we've initialized the parameters, we insert the body of the
885 inlined_body = &STMT_EXPR_STMT (expr);
886 while (*inlined_body)
887 inlined_body = &TREE_CHAIN (*inlined_body);
888 *inlined_body = copy_body (id);
890 /* Close the block for the parameters. */
891 scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
892 SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
893 if (! DECL_INITIAL (fn)
894 || TREE_CODE (DECL_INITIAL (fn)) != BLOCK)
896 remap_block (scope_stmt, NULL_TREE, id);
897 STMT_EXPR_STMT (expr)
898 = chainon (STMT_EXPR_STMT (expr), scope_stmt);
900 /* After the body of the function comes the RET_LABEL. This must come
901 before we evaluate the returned value below, because that evalulation
902 may cause RTL to be generated. */
903 STMT_EXPR_STMT (expr)
904 = chainon (STMT_EXPR_STMT (expr),
905 build_stmt (LABEL_STMT, id->ret_label));
907 /* Finally, mention the returned value so that the value of the
908 statement-expression is the returned value of the function. */
909 STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), use_stmt);
912 splay_tree_delete (id->decl_map);
915 /* The new expression has side-effects if the old one did. */
916 TREE_SIDE_EFFECTS (expr) = TREE_SIDE_EFFECTS (t);
918 /* Replace the call by the inlined body. Wrap it in an
919 EXPR_WITH_FILE_LOCATION so that we'll get debugging line notes
920 pointing to the right place. */
921 chain = TREE_CHAIN (*tp);
922 *tp = build_expr_wfl (expr, DECL_SOURCE_FILE (fn), DECL_SOURCE_LINE (fn),
924 EXPR_WFL_EMIT_LINE_NOTE (*tp) = 1;
925 TREE_CHAIN (*tp) = chain;
928 /* If the value of the new expression is ignored, that's OK. We
929 don't warn about this for CALL_EXPRs, so we shouldn't warn about
930 the equivalent inlined version either. */
933 /* Our function now has more statements than it did before. */
934 DECL_NUM_STMTS (VARRAY_TREE (id->fns, 0)) += DECL_NUM_STMTS (fn);
935 id->inlined_stmts += DECL_NUM_STMTS (fn);
937 /* Recurse into the body of the just inlined function. */
938 expand_calls_inline (inlined_body, id);
939 VARRAY_POP (id->fns);
941 /* If we've returned to the top level, clear out the record of how
942 much inlining has been done. */
943 if (VARRAY_ACTIVE_SIZE (id->fns) == id->first_inlined_fn)
944 id->inlined_stmts = 0;
946 /* Don't walk into subtrees. We've already handled them above. */
949 /* Keep iterating. */
953 /* Walk over the entire tree *TP, replacing CALL_EXPRs with inline
954 expansions as appropriate. */
957 expand_calls_inline (tp, id)
961 /* Search through *TP, replacing all calls to inline functions by
962 appropriate equivalents. Use walk_tree in no-duplicates mode
963 to avoid exponential time complexity. (We can't just use
964 walk_tree_without_duplicates, because of the special TARGET_EXPR
965 handling in expand_calls. The hash table is set up in
966 optimize_function. */
967 walk_tree (tp, expand_call_inline, id, id->tree_pruner);
970 /* Expand calls to inline functions in the body of FN. */
973 optimize_inline_calls (fn)
980 memset (&id, 0, sizeof (id));
982 /* Don't allow recursion into FN. */
983 VARRAY_TREE_INIT (id.fns, 32, "fns");
984 VARRAY_PUSH_TREE (id.fns, fn);
985 /* Or any functions that aren't finished yet. */
987 if (current_function_decl)
989 VARRAY_PUSH_TREE (id.fns, current_function_decl);
990 prev_fn = current_function_decl;
993 prev_fn = ((*lang_hooks.tree_inlining.add_pending_fn_decls)
996 /* Create the stack of TARGET_EXPRs. */
997 VARRAY_TREE_INIT (id.target_exprs, 32, "target_exprs");
999 /* Create the list of functions this call will inline. */
1000 VARRAY_TREE_INIT (id.inlined_fns, 32, "inlined_fns");
1002 /* Keep track of the low-water mark, i.e., the point where the first
1003 real inlining is represented in ID.FNS. */
1004 id.first_inlined_fn = VARRAY_ACTIVE_SIZE (id.fns);
1006 /* Replace all calls to inline functions with the bodies of those
1008 id.tree_pruner = htab_create (37, htab_hash_pointer,
1009 htab_eq_pointer, NULL);
1010 expand_calls_inline (&DECL_SAVED_TREE (fn), &id);
1013 htab_delete (id.tree_pruner);
1014 VARRAY_FREE (id.fns);
1015 VARRAY_FREE (id.target_exprs);
1016 if (DECL_LANG_SPECIFIC (fn))
1018 tree ifn = make_tree_vec (VARRAY_ACTIVE_SIZE (id.inlined_fns));
1020 memcpy (&TREE_VEC_ELT (ifn, 0), &VARRAY_TREE (id.inlined_fns, 0),
1021 VARRAY_ACTIVE_SIZE (id.inlined_fns) * sizeof (tree));
1022 DECL_INLINED_FNS (fn) = ifn;
1024 VARRAY_FREE (id.inlined_fns);
1027 /* FN is a function that has a complete body, and CLONE is a function
1028 whose body is to be set to a copy of FN, mapping argument
1029 declarations according to the ARG_MAP splay_tree. */
1032 clone_body (clone, fn, arg_map)
1038 /* Clone the body, as if we were making an inline call. But, remap
1039 the parameters in the callee to the parameters of caller. If
1040 there's an in-charge parameter, map it to an appropriate
1042 memset (&id, 0, sizeof (id));
1043 VARRAY_TREE_INIT (id.fns, 2, "fns");
1044 VARRAY_PUSH_TREE (id.fns, clone);
1045 VARRAY_PUSH_TREE (id.fns, fn);
1046 id.decl_map = (splay_tree)arg_map;
1048 /* Cloning is treated slightly differently from inlining. Set
1049 CLONING_P so that it's clear which operation we're performing. */
1050 id.cloning_p = true;
1052 /* Actually copy the body. */
1053 TREE_CHAIN (DECL_SAVED_TREE (clone)) = copy_body (&id);
1056 VARRAY_FREE (id.fns);
1059 /* Apply FUNC to all the sub-trees of TP in a pre-order traversal.
1060 FUNC is called with the DATA and the address of each sub-tree. If
1061 FUNC returns a non-NULL value, the traversal is aborted, and the
1062 value returned by FUNC is returned. If HTAB is non-NULL it is used
1063 to record the nodes visited, and to avoid visiting a node more than
1067 walk_tree (tp, func, data, htab_)
1073 htab_t htab = (htab_t) htab_;
1074 enum tree_code code;
1078 #define WALK_SUBTREE(NODE) \
1081 result = walk_tree (&(NODE), func, data, htab); \
1087 /* Skip empty subtrees. */
1095 /* Don't walk the same tree twice, if the user has requested
1096 that we avoid doing so. */
1097 if (htab_find (htab, *tp))
1099 /* If we haven't already seen this node, add it to the table. */
1100 slot = htab_find_slot (htab, *tp, INSERT);
1104 /* Call the function. */
1106 result = (*func) (tp, &walk_subtrees, data);
1108 /* If we found something, return it. */
1112 code = TREE_CODE (*tp);
1114 /* Even if we didn't, FUNC may have decided that there was nothing
1115 interesting below this point in the tree. */
1118 if (statement_code_p (code) || code == TREE_LIST
1119 || (*lang_hooks.tree_inlining.tree_chain_matters_p) (*tp))
1120 /* But we still need to check our siblings. */
1121 return walk_tree (&TREE_CHAIN (*tp), func, data, htab);
1126 /* Handle common cases up front. */
1127 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
1128 || TREE_CODE_CLASS (code) == 'r'
1129 || TREE_CODE_CLASS (code) == 's')
1133 /* Set lineno here so we get the right instantiation context
1134 if we call instantiate_decl from inlinable_function_p. */
1135 if (statement_code_p (code) && !STMT_LINENO_FOR_FN_P (*tp))
1136 lineno = STMT_LINENO (*tp);
1138 /* Walk over all the sub-trees of this operand. */
1139 len = first_rtl_op (code);
1140 /* TARGET_EXPRs are peculiar: operands 1 and 3 can be the same.
1141 But, we only want to walk once. */
1142 if (code == TARGET_EXPR
1143 && TREE_OPERAND (*tp, 3) == TREE_OPERAND (*tp, 1))
1145 /* Go through the subtrees. We need to do this in forward order so
1146 that the scope of a FOR_EXPR is handled properly. */
1147 for (i = 0; i < len; ++i)
1148 WALK_SUBTREE (TREE_OPERAND (*tp, i));
1150 /* For statements, we also walk the chain so that we cover the
1151 entire statement tree. */
1152 if (statement_code_p (code))
1154 if (code == DECL_STMT
1155 && DECL_STMT_DECL (*tp)
1156 && DECL_P (DECL_STMT_DECL (*tp)))
1158 /* Walk the DECL_INITIAL and DECL_SIZE. We don't want to walk
1159 into declarations that are just mentioned, rather than
1160 declared; they don't really belong to this part of the tree.
1161 And, we can see cycles: the initializer for a declaration can
1162 refer to the declaration itself. */
1163 WALK_SUBTREE (DECL_INITIAL (DECL_STMT_DECL (*tp)));
1164 WALK_SUBTREE (DECL_SIZE (DECL_STMT_DECL (*tp)));
1165 WALK_SUBTREE (DECL_SIZE_UNIT (DECL_STMT_DECL (*tp)));
1168 /* This can be tail-recursion optimized if we write it this way. */
1169 return walk_tree (&TREE_CHAIN (*tp), func, data, htab);
1172 /* We didn't find what we were looking for. */
1175 else if (TREE_CODE_CLASS (code) == 'd')
1177 WALK_SUBTREE (TREE_TYPE (*tp));
1179 /* We didn't find what we were looking for. */
1183 result = (*lang_hooks.tree_inlining.walk_subtrees) (tp, &walk_subtrees, func,
1185 if (result || ! walk_subtrees)
1188 /* Not one of the easy cases. We must explicitly go through the
1193 case IDENTIFIER_NODE:
1206 /* None of thse have subtrees other than those already walked
1211 case REFERENCE_TYPE:
1212 WALK_SUBTREE (TREE_TYPE (*tp));
1216 WALK_SUBTREE (TREE_VALUE (*tp));
1217 WALK_SUBTREE (TREE_CHAIN (*tp));
1222 int len = TREE_VEC_LENGTH (*tp);
1224 WALK_SUBTREE (TREE_VEC_ELT (*tp, len));
1229 WALK_SUBTREE (TREE_REALPART (*tp));
1230 WALK_SUBTREE (TREE_IMAGPART (*tp));
1234 WALK_SUBTREE (CONSTRUCTOR_ELTS (*tp));
1238 WALK_SUBTREE (TYPE_METHOD_BASETYPE (*tp));
1242 WALK_SUBTREE (TREE_TYPE (*tp));
1244 tree arg = TYPE_ARG_TYPES (*tp);
1246 /* We never want to walk into default arguments. */
1247 for (; arg; arg = TREE_CHAIN (arg))
1248 WALK_SUBTREE (TREE_VALUE (arg));
1253 WALK_SUBTREE (TREE_TYPE (*tp));
1254 WALK_SUBTREE (TYPE_DOMAIN (*tp));
1258 WALK_SUBTREE (TYPE_MIN_VALUE (*tp));
1259 WALK_SUBTREE (TYPE_MAX_VALUE (*tp));
1263 WALK_SUBTREE (TREE_TYPE (*tp));
1264 WALK_SUBTREE (TYPE_OFFSET_BASETYPE (*tp));
1271 /* We didn't find what we were looking for. */
1277 /* Like walk_tree, but does not walk duplicate nodes more than
1281 walk_tree_without_duplicates (tp, func, data)
1289 htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL);
1290 result = walk_tree (tp, func, data, htab);
1295 /* Passed to walk_tree. Copies the node pointed to, if appropriate. */
1298 copy_tree_r (tp, walk_subtrees, data)
1301 void *data ATTRIBUTE_UNUSED;
1303 enum tree_code code = TREE_CODE (*tp);
1305 /* We make copies of most nodes. */
1306 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
1307 || TREE_CODE_CLASS (code) == 'r'
1308 || TREE_CODE_CLASS (code) == 'c'
1309 || TREE_CODE_CLASS (code) == 's'
1310 || code == TREE_LIST
1312 || (*lang_hooks.tree_inlining.tree_chain_matters_p) (*tp))
1314 /* Because the chain gets clobbered when we make a copy, we save it
1316 tree chain = TREE_CHAIN (*tp);
1318 /* Copy the node. */
1319 *tp = copy_node (*tp);
1321 /* Now, restore the chain, if appropriate. That will cause
1322 walk_tree to walk into the chain as well. */
1323 if (code == PARM_DECL || code == TREE_LIST
1324 || (*lang_hooks.tree_inlining.tree_chain_matters_p) (*tp)
1325 || statement_code_p (code))
1326 TREE_CHAIN (*tp) = chain;
1328 /* For now, we don't update BLOCKs when we make copies. So, we
1329 have to nullify all scope-statements. */
1330 if (TREE_CODE (*tp) == SCOPE_STMT)
1331 SCOPE_STMT_BLOCK (*tp) = NULL_TREE;
1333 else if (TREE_CODE_CLASS (code) == 't')
1334 /* There's no need to copy types, or anything beneath them. */
1340 /* The SAVE_EXPR pointed to by TP is being copied. If ST contains
1341 information indicating to what new SAVE_EXPR this one should be
1342 mapped, use that one. Otherwise, create a new node and enter it in
1343 ST. FN is the function into which the copy will be placed. */
1346 remap_save_expr (tp, st_, fn, walk_subtrees)
1352 splay_tree st = (splay_tree) st_;
1355 /* See if we already encountered this SAVE_EXPR. */
1356 n = splay_tree_lookup (st, (splay_tree_key) *tp);
1358 /* If we didn't already remap this SAVE_EXPR, do so now. */
1361 tree t = copy_node (*tp);
1363 /* The SAVE_EXPR is now part of the function into which we
1364 are inlining this body. */
1365 SAVE_EXPR_CONTEXT (t) = fn;
1366 /* And we haven't evaluated it yet. */
1367 SAVE_EXPR_RTL (t) = NULL_RTX;
1368 /* Remember this SAVE_EXPR. */
1369 n = splay_tree_insert (st,
1370 (splay_tree_key) *tp,
1371 (splay_tree_value) t);
1374 /* We've already walked into this SAVE_EXPR, so we needn't do it
1378 /* Replace this SAVE_EXPR with the copy. */
1379 *tp = (tree) n->value;