1 /* Perform optimizations on tree structure.
2 Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
3 Written by Mark Michell (mark@codesourcery.com).
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify it
8 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, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 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 the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
27 #include "insn-config.h"
29 #include "integrate.h"
38 o In order to make inlining-on-trees work, we pessimized
39 function-local static constants. In particular, they are now
40 always output, even when not addressed. Fix this by treating
41 function-local static constants just like global static
42 constants; the back-end already knows not to output them if they
45 o Provide heuristics to clamp inlining of recursive template
48 /* Data required for function inlining. */
50 typedef struct inline_data
52 /* A stack of the functions we are inlining. For example, if we are
53 compiling `f', which calls `g', which calls `h', and we are
54 inlining the body of `h', the stack will contain, `h', followed
55 by `g', followed by `f'. The first few elements of the stack may
56 contain other functions that we know we should not recurse into,
57 even though they are not directly being inlined. */
59 /* The index of the first element of FNS that really represents an
61 unsigned first_inlined_fn;
62 /* The label to jump to when a return statement is encountered. If
63 this value is NULL, then return statements will simply be
64 remapped as return statements, rather than as jumps. */
66 /* The map from local declarations in the inlined function to
67 equivalents in the function into which it is being inlined. */
69 /* Nonzero if we are currently within the cleanup for a
71 int in_target_cleanup_p;
72 /* A stack of the TARGET_EXPRs that we are currently processing. */
73 varray_type target_exprs;
74 /* A list of the functions current function has inlined. */
75 varray_type inlined_fns;
76 /* The approximate number of statements we have inlined in the
77 current call stack. */
79 /* We use the same mechanism to build clones that we do to perform
80 inlining. However, there are a few places where we need to
81 distinguish between those two situations. This flag is true nif
82 we are cloning, rather than inlining. */
84 /* Hash table used to prevent walk_tree from visiting the same node
85 umpteen million times. */
91 static tree initialize_inlined_parameters PARAMS ((inline_data *, tree, tree));
92 static tree declare_return_variable PARAMS ((inline_data *, tree *));
93 static tree copy_body_r PARAMS ((tree *, int *, void *));
94 static tree copy_body PARAMS ((inline_data *));
95 static tree expand_call_inline PARAMS ((tree *, int *, void *));
96 static void expand_calls_inline PARAMS ((tree *, inline_data *));
97 static int inlinable_function_p PARAMS ((tree, inline_data *));
98 static tree remap_decl PARAMS ((tree, inline_data *));
99 static void remap_block PARAMS ((tree, tree, inline_data *));
100 static void copy_scope_stmt PARAMS ((tree *, int *, inline_data *));
101 static tree calls_setjmp_r PARAMS ((tree *, int *, void *));
102 static void update_cloned_parm PARAMS ((tree, tree));
104 /* The approximate number of instructions per statement. This number
105 need not be particularly accurate; it is used only to make
106 decisions about when a function is too big to inline. */
107 #define INSNS_PER_STMT (10)
109 /* Remap DECL during the copying of the BLOCK tree for the function.
110 DATA is really an `inline_data *'. */
113 remap_decl (decl, id)
120 /* We only remap local variables in the current function. */
121 fn = VARRAY_TOP_TREE (id->fns);
122 if (!nonstatic_local_decl_p (decl) || DECL_CONTEXT (decl) != fn)
125 /* See if we have remapped this declaration. */
126 n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl);
127 /* If we didn't already have an equivalent for this declaration,
133 /* Make a copy of the variable or label. */
134 t = copy_decl_for_inlining (decl, fn,
135 VARRAY_TREE (id->fns, 0));
137 /* The decl T could be a dynamic array or other variable size type,
138 in which case some fields need to be remapped because they may
139 contain SAVE_EXPRs. */
140 walk_tree (&DECL_SIZE (t), copy_body_r, id, NULL);
141 walk_tree (&DECL_SIZE_UNIT (t), copy_body_r, id, NULL);
142 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE
143 && TYPE_DOMAIN (TREE_TYPE (t)))
145 TREE_TYPE (t) = copy_node (TREE_TYPE (t));
146 TYPE_DOMAIN (TREE_TYPE (t))
147 = copy_node (TYPE_DOMAIN (TREE_TYPE (t)));
148 walk_tree (&TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (t))),
149 copy_body_r, id, NULL);
152 /* Remember it, so that if we encounter this local entity
153 again we can reuse this copy. */
154 n = splay_tree_insert (id->decl_map,
155 (splay_tree_key) decl,
156 (splay_tree_value) t);
159 return (tree) n->value;
162 /* Copy the SCOPE_STMT_BLOCK associated with SCOPE_STMT to contain
163 remapped versions of the variables therein. And hook the new block
164 into the block-tree. If non-NULL, the DECLS are declarations to
165 add to use instead of the BLOCK_VARS in the old block. */
168 remap_block (scope_stmt, decls, id)
173 /* We cannot do this in the cleanup for a TARGET_EXPR since we do
174 not know whether or not expand_expr will actually write out the
175 code we put there. If it does not, then we'll have more BLOCKs
176 than block-notes, and things will go awry. At some point, we
177 should make the back-end handle BLOCK notes in a tidier way,
178 without requiring a strict correspondence to the block-tree; then
179 this check can go. */
180 if (id->in_target_cleanup_p)
182 SCOPE_STMT_BLOCK (scope_stmt) = NULL_TREE;
186 /* If this is the beginning of a scope, remap the associated BLOCK. */
187 if (SCOPE_BEGIN_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt))
194 /* Make the new block. */
195 old_block = SCOPE_STMT_BLOCK (scope_stmt);
196 new_block = make_node (BLOCK);
197 TREE_USED (new_block) = TREE_USED (old_block);
198 BLOCK_ABSTRACT_ORIGIN (new_block) = old_block;
199 SCOPE_STMT_BLOCK (scope_stmt) = new_block;
201 /* Remap its variables. */
202 for (old_var = decls ? decls : BLOCK_VARS (old_block);
204 old_var = TREE_CHAIN (old_var))
208 /* Remap the variable. */
209 new_var = remap_decl (old_var, id);
210 /* If we didn't remap this variable, so we can't mess with
211 its TREE_CHAIN. If we remapped this variable to
212 something other than a declaration (say, if we mapped it
213 to a constant), then we must similarly omit any mention
215 if (!new_var || !DECL_P (new_var))
219 TREE_CHAIN (new_var) = BLOCK_VARS (new_block);
220 BLOCK_VARS (new_block) = new_var;
223 /* We put the BLOCK_VARS in reverse order; fix that now. */
224 BLOCK_VARS (new_block) = nreverse (BLOCK_VARS (new_block));
225 fn = VARRAY_TREE (id->fns, 0);
227 /* We're building a clone; DECL_INITIAL is still
228 error_mark_node, and current_binding_level is the parm
230 insert_block (new_block);
233 /* Attach this new block after the DECL_INITIAL block for the
234 function into which this block is being inlined. In
235 rest_of_compilation we will straighten out the BLOCK tree. */
237 if (DECL_INITIAL (fn))
238 first_block = &BLOCK_CHAIN (DECL_INITIAL (fn));
240 first_block = &DECL_INITIAL (fn);
241 BLOCK_CHAIN (new_block) = *first_block;
242 *first_block = new_block;
244 /* Remember the remapped block. */
245 splay_tree_insert (id->decl_map,
246 (splay_tree_key) old_block,
247 (splay_tree_value) new_block);
249 /* If this is the end of a scope, set the SCOPE_STMT_BLOCK to be the
251 else if (SCOPE_END_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt))
255 /* Find this block in the table of remapped things. */
256 n = splay_tree_lookup (id->decl_map,
257 (splay_tree_key) SCOPE_STMT_BLOCK (scope_stmt));
258 my_friendly_assert (n != NULL, 19991203);
259 SCOPE_STMT_BLOCK (scope_stmt) = (tree) n->value;
263 /* Copy the SCOPE_STMT pointed to by TP. */
266 copy_scope_stmt (tp, walk_subtrees, id)
273 /* Remember whether or not this statement was nullified. When
274 making a copy, copy_tree_r always sets SCOPE_NULLIFIED_P (and
275 doesn't copy the SCOPE_STMT_BLOCK) to free callers from having to
276 deal with copying BLOCKs if they do not wish to do so. */
277 block = SCOPE_STMT_BLOCK (*tp);
278 /* Copy (and replace) the statement. */
279 copy_tree_r (tp, walk_subtrees, NULL);
280 /* Restore the SCOPE_STMT_BLOCK. */
281 SCOPE_STMT_BLOCK (*tp) = block;
283 /* Remap the associated block. */
284 remap_block (*tp, NULL_TREE, id);
287 /* Called from copy_body via walk_tree. DATA is really an
291 copy_body_r (tp, walk_subtrees, data)
300 id = (inline_data *) data;
301 fn = VARRAY_TOP_TREE (id->fns);
303 /* All automatic variables should have a DECL_CONTEXT indicating
304 what function they come from. */
305 if ((TREE_CODE (*tp) == VAR_DECL || TREE_CODE (*tp) == LABEL_DECL)
306 && DECL_NAMESPACE_SCOPE_P (*tp))
307 my_friendly_assert (DECL_EXTERNAL (*tp) || TREE_STATIC (*tp),
310 /* If this is a RETURN_STMT, change it into an EXPR_STMT and a
311 GOTO_STMT with the RET_LABEL as its target. */
312 if (TREE_CODE (*tp) == RETURN_STMT && id->ret_label)
314 tree return_stmt = *tp;
317 /* Build the GOTO_STMT. */
318 goto_stmt = build_stmt (GOTO_STMT, id->ret_label);
319 TREE_CHAIN (goto_stmt) = TREE_CHAIN (return_stmt);
321 /* If we're returning something, just turn that into an
322 assignment into the equivalent of the original
324 if (RETURN_EXPR (return_stmt))
326 *tp = build_stmt (EXPR_STMT,
327 RETURN_EXPR (return_stmt));
328 STMT_IS_FULL_EXPR_P (*tp) = 1;
329 /* And then jump to the end of the function. */
330 TREE_CHAIN (*tp) = goto_stmt;
332 /* If we're not returning anything just do the jump. */
336 /* Local variables and labels need to be replaced by equivalent
337 variables. We don't want to copy static variables; there's only
338 one of those, no matter how many times we inline the containing
340 else if (nonstatic_local_decl_p (*tp) && DECL_CONTEXT (*tp) == fn)
344 /* Remap the declaration. */
345 new_decl = remap_decl (*tp, id);
346 my_friendly_assert (new_decl != NULL_TREE, 19991203);
347 /* Replace this variable with the copy. */
348 STRIP_TYPE_NOPS (new_decl);
351 else if (nonstatic_local_decl_p (*tp)
352 && DECL_CONTEXT (*tp) != VARRAY_TREE (id->fns, 0))
353 my_friendly_abort (0);
354 else if (TREE_CODE (*tp) == SAVE_EXPR)
355 remap_save_expr (tp, id->decl_map, VARRAY_TREE (id->fns, 0),
357 else if (TREE_CODE (*tp) == UNSAVE_EXPR)
358 /* UNSAVE_EXPRs should not be generated until expansion time. */
359 my_friendly_abort (19991113);
360 /* For a SCOPE_STMT, we must copy the associated block so that we
361 can write out debugging information for the inlined variables. */
362 else if (TREE_CODE (*tp) == SCOPE_STMT && !id->in_target_cleanup_p)
363 copy_scope_stmt (tp, walk_subtrees, id);
364 /* Otherwise, just copy the node. Note that copy_tree_r already
365 knows not to copy VAR_DECLs, etc., so this is safe. */
368 copy_tree_r (tp, walk_subtrees, NULL);
370 /* The copied TARGET_EXPR has never been expanded, even if the
371 original node was expanded already. */
372 if (TREE_CODE (*tp) == TARGET_EXPR && TREE_OPERAND (*tp, 3))
374 TREE_OPERAND (*tp, 1) = TREE_OPERAND (*tp, 3);
375 TREE_OPERAND (*tp, 3) = NULL_TREE;
377 else if (TREE_CODE (*tp) == MODIFY_EXPR
378 && TREE_OPERAND (*tp, 0) == TREE_OPERAND (*tp, 1)
379 && nonstatic_local_decl_p (TREE_OPERAND (*tp, 0))
380 && DECL_CONTEXT (TREE_OPERAND (*tp, 0)) == fn)
382 /* Some assignments VAR = VAR; don't generate any rtl code
383 and thus don't count as variable modification. Avoid
384 keeping bogosities like 0 = 0. */
385 tree decl = TREE_OPERAND (*tp, 0), value;
388 n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl);
391 value = (tree) n->value;
392 STRIP_TYPE_NOPS (value);
393 if (TREE_CONSTANT (value) || TREE_READONLY_DECL_P (value))
399 /* Keep iterating. */
403 /* Make a copy of the body of FN so that it can be inserted inline in
412 body = DECL_SAVED_TREE (VARRAY_TOP_TREE (id->fns));
413 walk_tree (&body, copy_body_r, id, NULL);
418 /* Generate code to initialize the parameters of the function at the
419 top of the stack in ID from the ARGS (presented as a TREE_LIST). */
422 initialize_inlined_parameters (id, args, fn)
432 /* Figure out what the parameters are. */
433 parms = DECL_ARGUMENTS (fn);
435 /* Start with no initializations whatsoever. */
436 init_stmts = NULL_TREE;
438 /* Loop through the parameter declarations, replacing each with an
439 equivalent VAR_DECL, appropriately initialized. */
440 for (p = parms, a = args; p; a = TREE_CHAIN (a), p = TREE_CHAIN (p))
446 /* Find the initializer. */
447 value = TREE_VALUE (a);
448 /* If the parameter is never assigned to, we may not need to
449 create a new variable here at all. Instead, we may be able
450 to just use the argument value. */
451 if (TREE_READONLY (p)
452 && !TREE_ADDRESSABLE (p)
453 && !TREE_SIDE_EFFECTS (value))
455 /* Simplify the value, if possible. */
456 value = fold (decl_constant_value (value));
458 /* We can't risk substituting complex expressions. They
459 might contain variables that will be assigned to later.
460 Theoretically, we could check the expression to see if
461 all of the variables that determine its value are
462 read-only, but we don't bother. */
463 if (TREE_CONSTANT (value) || TREE_READONLY_DECL_P (value))
465 /* If this is a declaration, wrap it a NOP_EXPR so that
466 we don't try to put the VALUE on the list of
469 value = build1 (NOP_EXPR, TREE_TYPE (value), value);
471 splay_tree_insert (id->decl_map,
473 (splay_tree_value) value);
478 /* Make an equivalent VAR_DECL. */
479 var = copy_decl_for_inlining (p, fn, VARRAY_TREE (id->fns, 0));
480 /* Register the VAR_DECL as the equivalent for the PARM_DECL;
481 that way, when the PARM_DECL is encountered, it will be
482 automatically replaced by the VAR_DECL. */
483 splay_tree_insert (id->decl_map,
485 (splay_tree_value) var);
487 /* Declare this new variable. */
488 init_stmt = build_stmt (DECL_STMT, var);
489 TREE_CHAIN (init_stmt) = init_stmts;
490 init_stmts = init_stmt;
492 /* Initialize this VAR_DECL from the equivalent argument. If
493 the argument is an object, created via a constructor or copy,
494 this will not result in an extra copy: the TARGET_EXPR
495 representing the argument will be bound to VAR, and the
496 object will be constructed in VAR. */
497 if (! TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (p)))
498 DECL_INITIAL (var) = value;
501 init_stmt = build_stmt (EXPR_STMT,
502 build (INIT_EXPR, TREE_TYPE (p),
504 /* Add this initialization to the list. Note that we want the
505 declaration *after* the initialization because we are going
506 to reverse all the initialization statements below. */
507 TREE_CHAIN (init_stmt) = init_stmts;
508 init_stmts = init_stmt;
512 /* The initialization statements have been built up in reverse
513 order. Straighten them out now. */
514 return nreverse (init_stmts);
517 /* Declare a return variable to replace the RESULT_DECL for the
518 function we are calling. An appropriate DECL_STMT is returned.
519 The USE_STMT is filled in to contain a use of the declaration to
520 indicate the return value of the function. */
523 declare_return_variable (id, use_stmt)
524 struct inline_data *id;
527 tree fn = VARRAY_TOP_TREE (id->fns);
528 tree result = DECL_RESULT (fn);
530 int aggregate_return_p;
532 /* We don't need to do anything for functions that don't return
534 if (!result || VOID_TYPE_P (TREE_TYPE (result)))
536 *use_stmt = NULL_TREE;
540 /* Figure out whether or not FN returns an aggregate. */
541 aggregate_return_p = IS_AGGR_TYPE (TREE_TYPE (result));
543 /* If FN returns an aggregate then the caller will always create the
544 temporary (using a TARGET_EXPR) and the call will be the
545 initializing expression for the TARGET_EXPR. If we were just to
546 create a new VAR_DECL here, then the result of this function
547 would be copied (bitwise) into the variable initialized by the
548 TARGET_EXPR. That's incorrect, so we must transform any
549 references to the RESULT into references to the target. */
550 if (aggregate_return_p)
552 my_friendly_assert (VARRAY_ACTIVE_SIZE (id->target_exprs) != 0,
554 var = TREE_OPERAND (VARRAY_TOP_TREE (id->target_exprs), 0);
556 (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (var),
560 /* Otherwise, make an appropriate copy. */
562 var = copy_decl_for_inlining (result, fn, VARRAY_TREE (id->fns, 0));
564 /* Register the VAR_DECL as the equivalent for the RESULT_DECL; that
565 way, when the RESULT_DECL is encountered, it will be
566 automatically replaced by the VAR_DECL. */
567 splay_tree_insert (id->decl_map,
568 (splay_tree_key) result,
569 (splay_tree_value) var);
571 /* Build the USE_STMT. */
572 *use_stmt = build_stmt (EXPR_STMT, var);
574 /* Build the declaration statement if FN does not return an
576 if (!aggregate_return_p)
577 return build_stmt (DECL_STMT, var);
578 /* If FN does return an aggregate, there's no need to declare the
579 return variable; we're using a variable in our caller's frame. */
584 /* Returns non-zero if FN is a function that can be inlined. */
587 inlinable_function_p (fn, id)
593 /* If we've already decided this function shouldn't be inlined,
594 there's no need to check again. */
595 if (DECL_UNINLINABLE (fn))
598 /* Assume it is not inlinable. */
601 /* If we're not inlining things, then nothing is inlinable. */
602 if (!flag_inline_trees)
604 /* If the function was not declared `inline', then we don't inline
606 else if (!DECL_INLINE (fn))
608 /* We can't inline varargs functions. */
609 else if (varargs_function_p (fn))
611 /* We can't inline functions that are too big. */
612 else if (DECL_NUM_STMTS (fn) * INSNS_PER_STMT > MAX_INLINE_INSNS)
614 /* All is well. We can inline this function. Traditionally, GCC
615 has refused to inline functions using alloca, or functions whose
616 values are returned in a PARALLEL, and a few other such obscure
617 conditions. We are not equally constrained at the tree level. */
621 /* Squirrel away the result so that we don't have to check again. */
622 DECL_UNINLINABLE (fn) = !inlinable;
624 /* Even if this function is not itself too big to inline, it might
625 be that we've done so much inlining already that we don't want to
626 risk inlining any more. */
627 if ((DECL_NUM_STMTS (fn) + id->inlined_stmts) * INSNS_PER_STMT
631 /* We can inline a template instantiation only if it's fully
634 && DECL_TEMPLATE_INFO (fn)
635 && TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (fn)))
637 fn = instantiate_decl (fn, /*defer_ok=*/0);
638 inlinable = !TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (fn));
641 /* If we don't have the function body available, we can't inline
643 if (!DECL_SAVED_TREE (fn))
646 /* Don't do recursive inlining, either. We don't record this in
647 DECL_UNINLINABLE; we may be able to inline this function later. */
652 for (i = 0; i < VARRAY_ACTIVE_SIZE (id->fns); ++i)
653 if (VARRAY_TREE (id->fns, i) == fn)
656 if (inlinable && DECL_LANG_SPECIFIC (fn) && DECL_INLINED_FNS (fn))
659 tree inlined_fns = DECL_INLINED_FNS (fn);
661 for (j = 0; j < TREE_VEC_LENGTH (inlined_fns); ++j)
662 if (TREE_VEC_ELT (inlined_fns, j) == VARRAY_TREE (id->fns, 0))
667 /* Return the result. */
671 /* If *TP is a CALL_EXPR, replace it with its inline expansion. */
674 expand_call_inline (tp, walk_subtrees, data)
690 /* See what we've got. */
691 id = (inline_data *) data;
694 /* Recurse, but letting recursive invocations know that we are
695 inside the body of a TARGET_EXPR. */
696 if (TREE_CODE (*tp) == TARGET_EXPR)
698 int i, len = first_rtl_op (TARGET_EXPR);
700 /* We're walking our own subtrees. */
703 /* Push *TP on the stack of pending TARGET_EXPRs. */
704 VARRAY_PUSH_TREE (id->target_exprs, *tp);
706 /* Actually walk over them. This loop is the body of
707 walk_trees, omitting the case where the TARGET_EXPR
708 itself is handled. */
709 for (i = 0; i < len; ++i)
712 ++id->in_target_cleanup_p;
713 walk_tree (&TREE_OPERAND (*tp, i), expand_call_inline, data,
716 --id->in_target_cleanup_p;
719 /* We're done with this TARGET_EXPR now. */
720 VARRAY_POP (id->target_exprs);
726 /* Because types were not copied in copy_body, CALL_EXPRs beneath
727 them should not be expanded. This can happen if the type is a
728 dynamic array type, for example. */
731 /* From here on, we're only interested in CALL_EXPRs. */
732 if (TREE_CODE (t) != CALL_EXPR)
735 /* First, see if we can figure out what function is being called.
736 If we cannot, then there is no hope of inlining the function. */
737 fn = get_callee_fndecl (t);
741 /* Don't try to inline functions that are not well-suited to
743 if (!inlinable_function_p (fn, id))
746 /* Set the current filename and line number to the function we are
747 inlining so that when we create new _STMT nodes here they get
748 line numbers corresponding to the function we are calling. We
749 wrap the whole inlined body in an EXPR_WITH_FILE_AND_LINE as well
750 because individual statements don't record the filename. */
751 push_srcloc (fn->decl.filename, fn->decl.linenum);
753 /* Build a statement-expression containing code to initialize the
754 arguments, the actual inline expansion of the body, and a label
755 for the return statements within the function to jump to. The
756 type of the statement expression is the return type of the
758 expr = build_min (STMT_EXPR, TREE_TYPE (TREE_TYPE (fn)), NULL_TREE);
760 /* Local declarations will be replaced by their equivalents in this
763 id->decl_map = splay_tree_new (splay_tree_compare_pointers,
766 /* Initialize the parameters. */
767 arg_inits = initialize_inlined_parameters (id, TREE_OPERAND (t, 1), fn);
768 /* Expand any inlined calls in the initializers. Do this before we
769 push FN on the stack of functions we are inlining; we want to
770 inline calls to FN that appear in the initializers for the
772 expand_calls_inline (&arg_inits, id);
773 /* And add them to the tree. */
774 STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), arg_inits);
776 /* Record the function we are about to inline so that we can avoid
777 recursing into it. */
778 VARRAY_PUSH_TREE (id->fns, fn);
780 /* Record the function we are about to inline if optimize_function
781 has not been called on it yet and we don't have it in the list. */
782 if (DECL_LANG_SPECIFIC (fn) && !DECL_INLINED_FNS (fn))
786 for (i = VARRAY_ACTIVE_SIZE (id->inlined_fns) - 1; i >= 0; i--)
787 if (VARRAY_TREE (id->inlined_fns, i) == fn)
790 VARRAY_PUSH_TREE (id->inlined_fns, fn);
793 /* Return statements in the function body will be replaced by jumps
795 id->ret_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
796 DECL_CONTEXT (id->ret_label) = VARRAY_TREE (id->fns, 0);
798 /* Create a block to put the parameters in. We have to do this
799 after the parameters have been remapped because remapping
800 parameters is different from remapping ordinary variables. */
801 scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
802 SCOPE_BEGIN_P (scope_stmt) = 1;
803 SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
804 remap_block (scope_stmt, DECL_ARGUMENTS (fn), id);
805 TREE_CHAIN (scope_stmt) = STMT_EXPR_STMT (expr);
806 STMT_EXPR_STMT (expr) = scope_stmt;
808 /* Tell the debugging backends that this block represents the
809 outermost scope of the inlined function. */
810 if (SCOPE_STMT_BLOCK (scope_stmt))
811 BLOCK_ABSTRACT_ORIGIN (SCOPE_STMT_BLOCK (scope_stmt)) = DECL_ORIGIN (fn);
813 /* Declare the return variable for the function. */
814 STMT_EXPR_STMT (expr)
815 = chainon (STMT_EXPR_STMT (expr),
816 declare_return_variable (id, &use_stmt));
818 /* After we've initialized the parameters, we insert the body of the
820 inlined_body = &STMT_EXPR_STMT (expr);
821 while (*inlined_body)
822 inlined_body = &TREE_CHAIN (*inlined_body);
823 *inlined_body = copy_body (id);
825 /* Close the block for the parameters. */
826 scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
827 SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
828 my_friendly_assert (DECL_INITIAL (fn)
829 && TREE_CODE (DECL_INITIAL (fn)) == BLOCK,
831 remap_block (scope_stmt, NULL_TREE, id);
832 STMT_EXPR_STMT (expr)
833 = chainon (STMT_EXPR_STMT (expr), scope_stmt);
835 /* After the body of the function comes the RET_LABEL. This must come
836 before we evaluate the returned value below, because that evalulation
837 may cause RTL to be generated. */
838 STMT_EXPR_STMT (expr)
839 = chainon (STMT_EXPR_STMT (expr),
840 build_stmt (LABEL_STMT, id->ret_label));
842 /* Finally, mention the returned value so that the value of the
843 statement-expression is the returned value of the function. */
844 STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), use_stmt);
847 splay_tree_delete (id->decl_map);
850 /* The new expression has side-effects if the old one did. */
851 TREE_SIDE_EFFECTS (expr) = TREE_SIDE_EFFECTS (t);
853 /* Replace the call by the inlined body. Wrap it in an
854 EXPR_WITH_FILE_LOCATION so that we'll get debugging line notes
855 pointing to the right place. */
856 chain = TREE_CHAIN (*tp);
857 *tp = build_expr_wfl (expr, DECL_SOURCE_FILE (fn), DECL_SOURCE_LINE (fn),
859 EXPR_WFL_EMIT_LINE_NOTE (*tp) = 1;
860 TREE_CHAIN (*tp) = chain;
863 /* If the value of the new expression is ignored, that's OK. We
864 don't warn about this for CALL_EXPRs, so we shouldn't warn about
865 the equivalent inlined version either. */
868 /* Our function now has more statements than it did before. */
869 DECL_NUM_STMTS (VARRAY_TREE (id->fns, 0)) += DECL_NUM_STMTS (fn);
870 id->inlined_stmts += DECL_NUM_STMTS (fn);
872 /* Recurse into the body of the just inlined function. */
873 expand_calls_inline (inlined_body, id);
874 VARRAY_POP (id->fns);
876 /* If we've returned to the top level, clear out the record of how
877 much inlining has been done. */
878 if (VARRAY_ACTIVE_SIZE (id->fns) == id->first_inlined_fn)
879 id->inlined_stmts = 0;
881 /* Don't walk into subtrees. We've already handled them above. */
884 /* Keep iterating. */
888 /* Walk over the entire tree *TP, replacing CALL_EXPRs with inline
889 expansions as appropriate. */
892 expand_calls_inline (tp, id)
896 /* Search through *TP, replacing all calls to inline functions by
897 appropriate equivalents. Use walk_tree in no-duplicates mode
898 to avoid exponential time complexity. (We can't just use
899 walk_tree_without_duplicates, because of the special TARGET_EXPR
900 handling in expand_calls. The hash table is set up in
901 optimize_function. */
902 walk_tree (tp, expand_call_inline, id, id->tree_pruner);
905 /* Optimize the body of FN. */
908 optimize_function (fn)
911 /* While in this function, we may choose to go off and compile
912 another function. For example, we might instantiate a function
913 in the hopes of inlining it. Normally, that wouldn't trigger any
914 actual RTL code-generation -- but it will if the template is
915 actually needed. (For example, if it's address is taken, or if
916 some other function already refers to the template.) If
917 code-generation occurs, then garbage collection will occur, so we
918 must protect ourselves, just as we do while building up the body
922 /* Expand calls to inline functions. */
923 if (flag_inline_trees)
927 struct saved_scope *s;
930 memset (&id, 0, sizeof (id));
932 /* Don't allow recursion into FN. */
933 VARRAY_TREE_INIT (id.fns, 32, "fns");
934 VARRAY_PUSH_TREE (id.fns, fn);
935 /* Or any functions that aren't finished yet. */
937 if (current_function_decl)
939 VARRAY_PUSH_TREE (id.fns, current_function_decl);
940 prev_fn = current_function_decl;
942 for (s = scope_chain; s; s = s->prev)
943 if (s->function_decl && s->function_decl != prev_fn)
945 VARRAY_PUSH_TREE (id.fns, s->function_decl);
946 prev_fn = s->function_decl;
949 /* Create the stack of TARGET_EXPRs. */
950 VARRAY_TREE_INIT (id.target_exprs, 32, "target_exprs");
952 /* Create the list of functions this call will inline. */
953 VARRAY_TREE_INIT (id.inlined_fns, 32, "inlined_fns");
955 /* Keep track of the low-water mark, i.e., the point where
956 the first real inlining is represented in ID.FNS. */
957 id.first_inlined_fn = VARRAY_ACTIVE_SIZE (id.fns);
959 /* Replace all calls to inline functions with the bodies of those
961 id.tree_pruner = htab_create (37, htab_hash_pointer,
962 htab_eq_pointer, NULL);
963 expand_calls_inline (&DECL_SAVED_TREE (fn), &id);
966 htab_delete (id.tree_pruner);
967 VARRAY_FREE (id.fns);
968 VARRAY_FREE (id.target_exprs);
969 if (DECL_LANG_SPECIFIC (fn))
971 tree ifn = make_tree_vec (VARRAY_ACTIVE_SIZE (id.inlined_fns));
973 memcpy (&TREE_VEC_ELT (ifn, 0), &VARRAY_TREE (id.inlined_fns, 0),
974 VARRAY_ACTIVE_SIZE (id.inlined_fns) * sizeof (tree));
975 DECL_INLINED_FNS (fn) = ifn;
977 VARRAY_FREE (id.inlined_fns);
980 /* Undo the call to ggc_push_context above. */
984 /* Called from calls_setjmp_p via walk_tree. */
987 calls_setjmp_r (tp, walk_subtrees, data)
989 int *walk_subtrees ATTRIBUTE_UNUSED;
990 void *data ATTRIBUTE_UNUSED;
992 /* We're only interested in FUNCTION_DECLS. */
993 if (TREE_CODE (*tp) != FUNCTION_DECL)
996 return setjmp_call_p (*tp) ? *tp : NULL_TREE;
999 /* Returns non-zero if FN calls `setjmp' or some other function that
1000 can return more than once. This function is conservative; it may
1001 occasionally return a non-zero value even when FN does not actually
1008 return walk_tree_without_duplicates (&DECL_SAVED_TREE (fn),
1013 /* CLONED_PARM is a copy of CLONE, generated for a cloned constructor
1014 or destructor. Update it to ensure that the source-position for
1015 the cloned parameter matches that for the original, and that the
1016 debugging generation code will be able to find the original PARM. */
1019 update_cloned_parm (parm, cloned_parm)
1023 DECL_ABSTRACT_ORIGIN (cloned_parm) = parm;
1025 /* The name may have changed from the declaration. */
1026 DECL_NAME (cloned_parm) = DECL_NAME (parm);
1027 DECL_SOURCE_FILE (cloned_parm) = DECL_SOURCE_FILE (parm);
1028 DECL_SOURCE_LINE (cloned_parm) = DECL_SOURCE_LINE (parm);
1032 /* FN is a function that has a complete body. Clone the body as
1033 necessary. Returns non-zero if there's no longer any need to
1034 process the main body. */
1037 maybe_clone_body (fn)
1044 /* We only clone constructors and destructors. */
1045 if (!DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)
1046 && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn))
1049 /* Emit the DWARF1 abstract instance. */
1050 note_deferral_of_defined_inline_function (fn);
1052 /* We know that any clones immediately follow FN in the TYPE_METHODS
1054 for (clone = TREE_CHAIN (fn);
1055 clone && DECL_CLONED_FUNCTION_P (clone);
1056 clone = TREE_CHAIN (clone), first = 0)
1062 /* Update CLONE's source position information to match FN's. */
1063 DECL_SOURCE_FILE (clone) = DECL_SOURCE_FILE (fn);
1064 DECL_SOURCE_LINE (clone) = DECL_SOURCE_LINE (fn);
1065 DECL_INLINE (clone) = DECL_INLINE (fn);
1066 DECL_DECLARED_INLINE_P (clone) = DECL_DECLARED_INLINE_P (fn);
1067 DECL_COMDAT (clone) = DECL_COMDAT (fn);
1068 DECL_WEAK (clone) = DECL_WEAK (fn);
1069 DECL_ONE_ONLY (clone) = DECL_ONE_ONLY (fn);
1070 DECL_SECTION_NAME (clone) = DECL_SECTION_NAME (fn);
1071 DECL_USE_TEMPLATE (clone) = DECL_USE_TEMPLATE (fn);
1072 DECL_EXTERNAL (clone) = DECL_EXTERNAL (fn);
1073 DECL_INTERFACE_KNOWN (clone) = DECL_INTERFACE_KNOWN (fn);
1074 DECL_NOT_REALLY_EXTERN (clone) = DECL_NOT_REALLY_EXTERN (fn);
1075 TREE_PUBLIC (clone) = TREE_PUBLIC (fn);
1077 /* Adjust the parameter names and locations. */
1078 parm = DECL_ARGUMENTS (fn);
1079 clone_parm = DECL_ARGUMENTS (clone);
1080 /* Update the `this' parameter, which is always first.
1081 Sometimes, we end update the `this' parameter twice because
1082 we process it again in the loop below. That is harmless. */
1083 update_cloned_parm (parm, clone_parm);
1084 if (DECL_HAS_IN_CHARGE_PARM_P (fn))
1085 parm = TREE_CHAIN (parm);
1086 if (DECL_HAS_VTT_PARM_P (fn))
1087 parm = TREE_CHAIN (parm);
1088 if (DECL_HAS_VTT_PARM_P (clone))
1089 clone_parm = TREE_CHAIN (clone_parm);
1091 parm = TREE_CHAIN (parm), clone_parm = TREE_CHAIN (clone_parm))
1093 /* Update this paramter. */
1094 update_cloned_parm (parm, clone_parm);
1095 /* We should only give unused information for one clone. */
1097 TREE_USED (clone_parm) = 1;
1100 /* Start processing the function. */
1101 push_to_top_level ();
1102 start_function (NULL_TREE, clone, NULL_TREE, SF_PRE_PARSED);
1104 /* Just clone the body, as if we were making an inline call.
1105 But, remap the parameters in the callee to the parameters of
1106 caller. If there's an in-charge parameter, map it to an
1107 appropriate constant. */
1108 memset (&id, 0, sizeof (id));
1109 VARRAY_TREE_INIT (id.fns, 2, "fns");
1110 VARRAY_PUSH_TREE (id.fns, clone);
1111 VARRAY_PUSH_TREE (id.fns, fn);
1113 /* Cloning is treated slightly differently from inlining. Set
1114 CLONING_P so that its clear which operation we're performing. */
1115 id.cloning_p = true;
1117 /* Remap the parameters. */
1118 id.decl_map = splay_tree_new (splay_tree_compare_pointers,
1121 parm = DECL_ARGUMENTS (fn),
1122 clone_parm = DECL_ARGUMENTS (clone);
1125 parm = TREE_CHAIN (parm))
1127 /* Map the in-charge parameter to an appropriate constant. */
1128 if (DECL_HAS_IN_CHARGE_PARM_P (fn) && parmno == 1)
1131 in_charge = in_charge_arg_for_name (DECL_NAME (clone));
1132 splay_tree_insert (id.decl_map,
1133 (splay_tree_key) parm,
1134 (splay_tree_value) in_charge);
1136 else if (DECL_ARTIFICIAL (parm)
1137 && DECL_NAME (parm) == vtt_parm_identifier)
1139 /* For a subobject constructor or destructor, the next
1140 argument is the VTT parameter. Remap the VTT_PARM
1141 from the CLONE to this parameter. */
1142 if (DECL_HAS_VTT_PARM_P (clone))
1144 DECL_ABSTRACT_ORIGIN (clone_parm) = parm;
1145 splay_tree_insert (id.decl_map,
1146 (splay_tree_key) parm,
1147 (splay_tree_value) clone_parm);
1148 clone_parm = TREE_CHAIN (clone_parm);
1150 /* Otherwise, map the VTT parameter to `NULL'. */
1153 splay_tree_insert (id.decl_map,
1154 (splay_tree_key) parm,
1155 (splay_tree_value) null_pointer_node);
1158 /* Map other parameters to their equivalents in the cloned
1162 splay_tree_insert (id.decl_map,
1163 (splay_tree_key) parm,
1164 (splay_tree_value) clone_parm);
1165 clone_parm = TREE_CHAIN (clone_parm);
1169 /* Actually copy the body. */
1170 TREE_CHAIN (DECL_SAVED_TREE (clone)) = copy_body (&id);
1172 /* There are as many statements in the clone as in the
1174 DECL_NUM_STMTS (clone) = DECL_NUM_STMTS (fn);
1177 splay_tree_delete (id.decl_map);
1178 VARRAY_FREE (id.fns);
1180 /* Now, expand this function into RTL, if appropriate. */
1181 finish_function (0);
1182 BLOCK_ABSTRACT_ORIGIN (DECL_INITIAL (clone)) = DECL_INITIAL (fn);
1183 expand_body (clone);
1184 pop_from_top_level ();
1187 /* We don't need to process the original function any further. */