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. 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 /* Don't try to inline functions that are not well-suited to
812 if (!inlinable_function_p (fn, id))
815 /* Set the current filename and line number to the function we are
816 inlining so that when we create new _STMT nodes here they get
817 line numbers corresponding to the function we are calling. We
818 wrap the whole inlined body in an EXPR_WITH_FILE_AND_LINE as well
819 because individual statements don't record the filename. */
820 push_srcloc (fn->decl.filename, fn->decl.linenum);
822 /* Build a statement-expression containing code to initialize the
823 arguments, the actual inline expansion of the body, and a label
824 for the return statements within the function to jump to. The
825 type of the statement expression is the return type of the
827 expr = build1 (STMT_EXPR, TREE_TYPE (TREE_TYPE (fn)), NULL_TREE);
829 /* Local declarations will be replaced by their equivalents in this
832 id->decl_map = splay_tree_new (splay_tree_compare_pointers,
835 /* Initialize the parameters. */
836 arg_inits = initialize_inlined_parameters (id, TREE_OPERAND (t, 1), fn);
837 /* Expand any inlined calls in the initializers. Do this before we
838 push FN on the stack of functions we are inlining; we want to
839 inline calls to FN that appear in the initializers for the
841 expand_calls_inline (&arg_inits, id);
842 /* And add them to the tree. */
843 STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), arg_inits);
845 /* Record the function we are about to inline so that we can avoid
846 recursing into it. */
847 VARRAY_PUSH_TREE (id->fns, fn);
849 /* Record the function we are about to inline if optimize_function
850 has not been called on it yet and we don't have it in the list. */
851 if (! DECL_INLINED_FNS (fn))
855 for (i = VARRAY_ACTIVE_SIZE (id->inlined_fns) - 1; i >= 0; i--)
856 if (VARRAY_TREE (id->inlined_fns, i) == fn)
859 VARRAY_PUSH_TREE (id->inlined_fns, fn);
862 /* Return statements in the function body will be replaced by jumps
864 id->ret_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
865 DECL_CONTEXT (id->ret_label) = VARRAY_TREE (id->fns, 0);
867 /* Create a block to put the parameters in. We have to do this
868 after the parameters have been remapped because remapping
869 parameters is different from remapping ordinary variables. */
870 scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
871 SCOPE_BEGIN_P (scope_stmt) = 1;
872 SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
873 remap_block (scope_stmt, DECL_ARGUMENTS (fn), id);
874 TREE_CHAIN (scope_stmt) = STMT_EXPR_STMT (expr);
875 STMT_EXPR_STMT (expr) = scope_stmt;
877 /* Tell the debugging backends that this block represents the
878 outermost scope of the inlined function. */
879 if (SCOPE_STMT_BLOCK (scope_stmt))
880 BLOCK_ABSTRACT_ORIGIN (SCOPE_STMT_BLOCK (scope_stmt)) = DECL_ORIGIN (fn);
882 /* Declare the return variable for the function. */
883 STMT_EXPR_STMT (expr)
884 = chainon (STMT_EXPR_STMT (expr),
885 declare_return_variable (id, &use_stmt));
887 /* After we've initialized the parameters, we insert the body of the
889 inlined_body = &STMT_EXPR_STMT (expr);
890 while (*inlined_body)
891 inlined_body = &TREE_CHAIN (*inlined_body);
892 *inlined_body = copy_body (id);
894 /* Close the block for the parameters. */
895 scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
896 SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
897 if (! DECL_INITIAL (fn)
898 || TREE_CODE (DECL_INITIAL (fn)) != BLOCK)
900 remap_block (scope_stmt, NULL_TREE, id);
901 STMT_EXPR_STMT (expr)
902 = chainon (STMT_EXPR_STMT (expr), scope_stmt);
904 /* After the body of the function comes the RET_LABEL. This must come
905 before we evaluate the returned value below, because that evalulation
906 may cause RTL to be generated. */
907 STMT_EXPR_STMT (expr)
908 = chainon (STMT_EXPR_STMT (expr),
909 build_stmt (LABEL_STMT, id->ret_label));
911 /* Finally, mention the returned value so that the value of the
912 statement-expression is the returned value of the function. */
913 STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), use_stmt);
916 splay_tree_delete (id->decl_map);
919 /* The new expression has side-effects if the old one did. */
920 TREE_SIDE_EFFECTS (expr) = TREE_SIDE_EFFECTS (t);
922 /* Replace the call by the inlined body. Wrap it in an
923 EXPR_WITH_FILE_LOCATION so that we'll get debugging line notes
924 pointing to the right place. */
925 chain = TREE_CHAIN (*tp);
926 *tp = build_expr_wfl (expr, DECL_SOURCE_FILE (fn), DECL_SOURCE_LINE (fn),
928 EXPR_WFL_EMIT_LINE_NOTE (*tp) = 1;
929 TREE_CHAIN (*tp) = chain;
932 /* If the value of the new expression is ignored, that's OK. We
933 don't warn about this for CALL_EXPRs, so we shouldn't warn about
934 the equivalent inlined version either. */
937 /* Our function now has more statements than it did before. */
938 DECL_NUM_STMTS (VARRAY_TREE (id->fns, 0)) += DECL_NUM_STMTS (fn);
939 id->inlined_stmts += DECL_NUM_STMTS (fn);
941 /* Recurse into the body of the just inlined function. */
942 expand_calls_inline (inlined_body, id);
943 VARRAY_POP (id->fns);
945 /* If we've returned to the top level, clear out the record of how
946 much inlining has been done. */
947 if (VARRAY_ACTIVE_SIZE (id->fns) == id->first_inlined_fn)
948 id->inlined_stmts = 0;
950 /* Don't walk into subtrees. We've already handled them above. */
953 /* Keep iterating. */
957 /* Walk over the entire tree *TP, replacing CALL_EXPRs with inline
958 expansions as appropriate. */
961 expand_calls_inline (tp, id)
965 /* Search through *TP, replacing all calls to inline functions by
966 appropriate equivalents. Use walk_tree in no-duplicates mode
967 to avoid exponential time complexity. (We can't just use
968 walk_tree_without_duplicates, because of the special TARGET_EXPR
969 handling in expand_calls. The hash table is set up in
970 optimize_function. */
971 walk_tree (tp, expand_call_inline, id, id->tree_pruner);
974 /* Expand calls to inline functions in the body of FN. */
977 optimize_inline_calls (fn)
984 memset (&id, 0, sizeof (id));
986 /* Don't allow recursion into FN. */
987 VARRAY_TREE_INIT (id.fns, 32, "fns");
988 VARRAY_PUSH_TREE (id.fns, fn);
989 /* Or any functions that aren't finished yet. */
991 if (current_function_decl)
993 VARRAY_PUSH_TREE (id.fns, current_function_decl);
994 prev_fn = current_function_decl;
997 prev_fn = ((*lang_hooks.tree_inlining.add_pending_fn_decls)
1000 /* Create the stack of TARGET_EXPRs. */
1001 VARRAY_TREE_INIT (id.target_exprs, 32, "target_exprs");
1003 /* Create the list of functions this call will inline. */
1004 VARRAY_TREE_INIT (id.inlined_fns, 32, "inlined_fns");
1006 /* Keep track of the low-water mark, i.e., the point where the first
1007 real inlining is represented in ID.FNS. */
1008 id.first_inlined_fn = VARRAY_ACTIVE_SIZE (id.fns);
1010 /* Replace all calls to inline functions with the bodies of those
1012 id.tree_pruner = htab_create (37, htab_hash_pointer,
1013 htab_eq_pointer, NULL);
1014 expand_calls_inline (&DECL_SAVED_TREE (fn), &id);
1017 htab_delete (id.tree_pruner);
1018 VARRAY_FREE (id.fns);
1019 VARRAY_FREE (id.target_exprs);
1020 if (DECL_LANG_SPECIFIC (fn))
1022 tree ifn = make_tree_vec (VARRAY_ACTIVE_SIZE (id.inlined_fns));
1024 memcpy (&TREE_VEC_ELT (ifn, 0), &VARRAY_TREE (id.inlined_fns, 0),
1025 VARRAY_ACTIVE_SIZE (id.inlined_fns) * sizeof (tree));
1026 DECL_INLINED_FNS (fn) = ifn;
1028 VARRAY_FREE (id.inlined_fns);
1031 /* FN is a function that has a complete body, and CLONE is a function
1032 whose body is to be set to a copy of FN, mapping argument
1033 declarations according to the ARG_MAP splay_tree. */
1036 clone_body (clone, fn, arg_map)
1042 /* Clone the body, as if we were making an inline call. But, remap
1043 the parameters in the callee to the parameters of caller. If
1044 there's an in-charge parameter, map it to an appropriate
1046 memset (&id, 0, sizeof (id));
1047 VARRAY_TREE_INIT (id.fns, 2, "fns");
1048 VARRAY_PUSH_TREE (id.fns, clone);
1049 VARRAY_PUSH_TREE (id.fns, fn);
1050 id.decl_map = (splay_tree)arg_map;
1052 /* Cloning is treated slightly differently from inlining. Set
1053 CLONING_P so that it's clear which operation we're performing. */
1054 id.cloning_p = true;
1056 /* Actually copy the body. */
1057 TREE_CHAIN (DECL_SAVED_TREE (clone)) = copy_body (&id);
1060 VARRAY_FREE (id.fns);
1063 /* Apply FUNC to all the sub-trees of TP in a pre-order traversal.
1064 FUNC is called with the DATA and the address of each sub-tree. If
1065 FUNC returns a non-NULL value, the traversal is aborted, and the
1066 value returned by FUNC is returned. If HTAB is non-NULL it is used
1067 to record the nodes visited, and to avoid visiting a node more than
1071 walk_tree (tp, func, data, htab_)
1077 htab_t htab = (htab_t) htab_;
1078 enum tree_code code;
1082 #define WALK_SUBTREE(NODE) \
1085 result = walk_tree (&(NODE), func, data, htab); \
1091 /* Skip empty subtrees. */
1099 /* Don't walk the same tree twice, if the user has requested
1100 that we avoid doing so. */
1101 if (htab_find (htab, *tp))
1103 /* If we haven't already seen this node, add it to the table. */
1104 slot = htab_find_slot (htab, *tp, INSERT);
1108 /* Call the function. */
1110 result = (*func) (tp, &walk_subtrees, data);
1112 /* If we found something, return it. */
1116 code = TREE_CODE (*tp);
1118 /* Even if we didn't, FUNC may have decided that there was nothing
1119 interesting below this point in the tree. */
1122 if (statement_code_p (code) || code == TREE_LIST
1123 || (*lang_hooks.tree_inlining.tree_chain_matters_p) (*tp))
1124 /* But we still need to check our siblings. */
1125 return walk_tree (&TREE_CHAIN (*tp), func, data, htab);
1130 /* Handle common cases up front. */
1131 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
1132 || TREE_CODE_CLASS (code) == 'r'
1133 || TREE_CODE_CLASS (code) == 's')
1137 /* Set lineno here so we get the right instantiation context
1138 if we call instantiate_decl from inlinable_function_p. */
1139 if (statement_code_p (code) && !STMT_LINENO_FOR_FN_P (*tp))
1140 lineno = STMT_LINENO (*tp);
1142 /* Walk over all the sub-trees of this operand. */
1143 len = first_rtl_op (code);
1144 /* TARGET_EXPRs are peculiar: operands 1 and 3 can be the same.
1145 But, we only want to walk once. */
1146 if (code == TARGET_EXPR
1147 && TREE_OPERAND (*tp, 3) == TREE_OPERAND (*tp, 1))
1149 /* Go through the subtrees. We need to do this in forward order so
1150 that the scope of a FOR_EXPR is handled properly. */
1151 for (i = 0; i < len; ++i)
1152 WALK_SUBTREE (TREE_OPERAND (*tp, i));
1154 /* For statements, we also walk the chain so that we cover the
1155 entire statement tree. */
1156 if (statement_code_p (code))
1158 if (code == DECL_STMT
1159 && DECL_STMT_DECL (*tp)
1160 && DECL_P (DECL_STMT_DECL (*tp)))
1162 /* Walk the DECL_INITIAL and DECL_SIZE. We don't want to walk
1163 into declarations that are just mentioned, rather than
1164 declared; they don't really belong to this part of the tree.
1165 And, we can see cycles: the initializer for a declaration can
1166 refer to the declaration itself. */
1167 WALK_SUBTREE (DECL_INITIAL (DECL_STMT_DECL (*tp)));
1168 WALK_SUBTREE (DECL_SIZE (DECL_STMT_DECL (*tp)));
1169 WALK_SUBTREE (DECL_SIZE_UNIT (DECL_STMT_DECL (*tp)));
1172 /* This can be tail-recursion optimized if we write it this way. */
1173 return walk_tree (&TREE_CHAIN (*tp), func, data, htab);
1176 /* We didn't find what we were looking for. */
1179 else if (TREE_CODE_CLASS (code) == 'd')
1181 WALK_SUBTREE (TREE_TYPE (*tp));
1183 /* We didn't find what we were looking for. */
1187 result = (*lang_hooks.tree_inlining.walk_subtrees) (tp, &walk_subtrees, func,
1189 if (result || ! walk_subtrees)
1192 /* Not one of the easy cases. We must explicitly go through the
1197 case IDENTIFIER_NODE:
1210 /* None of thse have subtrees other than those already walked
1215 case REFERENCE_TYPE:
1216 WALK_SUBTREE (TREE_TYPE (*tp));
1220 WALK_SUBTREE (TREE_VALUE (*tp));
1221 WALK_SUBTREE (TREE_CHAIN (*tp));
1226 int len = TREE_VEC_LENGTH (*tp);
1228 WALK_SUBTREE (TREE_VEC_ELT (*tp, len));
1233 WALK_SUBTREE (TREE_REALPART (*tp));
1234 WALK_SUBTREE (TREE_IMAGPART (*tp));
1238 WALK_SUBTREE (CONSTRUCTOR_ELTS (*tp));
1242 WALK_SUBTREE (TYPE_METHOD_BASETYPE (*tp));
1246 WALK_SUBTREE (TREE_TYPE (*tp));
1248 tree arg = TYPE_ARG_TYPES (*tp);
1250 /* We never want to walk into default arguments. */
1251 for (; arg; arg = TREE_CHAIN (arg))
1252 WALK_SUBTREE (TREE_VALUE (arg));
1257 WALK_SUBTREE (TREE_TYPE (*tp));
1258 WALK_SUBTREE (TYPE_DOMAIN (*tp));
1262 WALK_SUBTREE (TYPE_MIN_VALUE (*tp));
1263 WALK_SUBTREE (TYPE_MAX_VALUE (*tp));
1267 WALK_SUBTREE (TREE_TYPE (*tp));
1268 WALK_SUBTREE (TYPE_OFFSET_BASETYPE (*tp));
1275 /* We didn't find what we were looking for. */
1281 /* Like walk_tree, but does not walk duplicate nodes more than
1285 walk_tree_without_duplicates (tp, func, data)
1293 htab = htab_create (37, htab_hash_pointer, htab_eq_pointer, NULL);
1294 result = walk_tree (tp, func, data, htab);
1299 /* Passed to walk_tree. Copies the node pointed to, if appropriate. */
1302 copy_tree_r (tp, walk_subtrees, data)
1305 void *data ATTRIBUTE_UNUSED;
1307 enum tree_code code = TREE_CODE (*tp);
1309 /* We make copies of most nodes. */
1310 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code))
1311 || TREE_CODE_CLASS (code) == 'r'
1312 || TREE_CODE_CLASS (code) == 'c'
1313 || TREE_CODE_CLASS (code) == 's'
1314 || code == TREE_LIST
1316 || (*lang_hooks.tree_inlining.tree_chain_matters_p) (*tp))
1318 /* Because the chain gets clobbered when we make a copy, we save it
1320 tree chain = TREE_CHAIN (*tp);
1322 /* Copy the node. */
1323 *tp = copy_node (*tp);
1325 /* Now, restore the chain, if appropriate. That will cause
1326 walk_tree to walk into the chain as well. */
1327 if (code == PARM_DECL || code == TREE_LIST
1328 || (*lang_hooks.tree_inlining.tree_chain_matters_p) (*tp)
1329 || statement_code_p (code))
1330 TREE_CHAIN (*tp) = chain;
1332 /* For now, we don't update BLOCKs when we make copies. So, we
1333 have to nullify all scope-statements. */
1334 if (TREE_CODE (*tp) == SCOPE_STMT)
1335 SCOPE_STMT_BLOCK (*tp) = NULL_TREE;
1337 else if (TREE_CODE_CLASS (code) == 't')
1338 /* There's no need to copy types, or anything beneath them. */
1344 /* The SAVE_EXPR pointed to by TP is being copied. If ST contains
1345 information indicating to what new SAVE_EXPR this one should be
1346 mapped, use that one. Otherwise, create a new node and enter it in
1347 ST. FN is the function into which the copy will be placed. */
1350 remap_save_expr (tp, st_, fn, walk_subtrees)
1356 splay_tree st = (splay_tree) st_;
1359 /* See if we already encountered this SAVE_EXPR. */
1360 n = splay_tree_lookup (st, (splay_tree_key) *tp);
1362 /* If we didn't already remap this SAVE_EXPR, do so now. */
1365 tree t = copy_node (*tp);
1367 /* The SAVE_EXPR is now part of the function into which we
1368 are inlining this body. */
1369 SAVE_EXPR_CONTEXT (t) = fn;
1370 /* And we haven't evaluated it yet. */
1371 SAVE_EXPR_RTL (t) = NULL_RTX;
1372 /* Remember this SAVE_EXPR. */
1373 n = splay_tree_insert (st,
1374 (splay_tree_key) *tp,
1375 (splay_tree_value) t);
1378 /* We've already walked into this SAVE_EXPR, so we needn't do it
1382 /* Replace this SAVE_EXPR with the copy. */
1383 *tp = (tree) n->value;