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"
39 o In order to make inlining-on-trees work, we pessimized
40 function-local static constants. In particular, they are now
41 always output, even when not addressed. Fix this by treating
42 function-local static constants just like global static
43 constants; the back-end already knows not to output them if they
46 o Provide heuristics to clamp inlining of recursive template
49 /* Data required for function inlining. */
51 typedef struct inline_data
53 /* A stack of the functions we are inlining. For example, if we are
54 compiling `f', which calls `g', which calls `h', and we are
55 inlining the body of `h', the stack will contain, `h', followed
56 by `g', followed by `f'. The first few elements of the stack may
57 contain other functions that we know we should not recurse into,
58 even though they are not directly being inlined. */
60 /* The index of the first element of FNS that really represents an
62 unsigned first_inlined_fn;
63 /* The label to jump to when a return statement is encountered. If
64 this value is NULL, then return statements will simply be
65 remapped as return statements, rather than as jumps. */
67 /* The map from local declarations in the inlined function to
68 equivalents in the function into which it is being inlined. */
70 /* Nonzero if we are currently within the cleanup for a
72 int in_target_cleanup_p;
73 /* A stack of the TARGET_EXPRs that we are currently processing. */
74 varray_type target_exprs;
75 /* A list of the functions current function has inlined. */
76 varray_type inlined_fns;
77 /* The approximate number of statements we have inlined in the
78 current call stack. */
80 /* We use the same mechanism to build clones that we do to perform
81 inlining. However, there are a few places where we need to
82 distinguish between those two situations. This flag is true if
83 we are cloning, rather than inlining. */
85 /* Hash table used to prevent walk_tree from visiting the same node
86 umpteen million times. */
92 static tree initialize_inlined_parameters PARAMS ((inline_data *, tree, tree));
93 static tree declare_return_variable PARAMS ((inline_data *, tree *));
94 static tree copy_body_r PARAMS ((tree *, int *, void *));
95 static tree copy_body PARAMS ((inline_data *));
96 static tree expand_call_inline PARAMS ((tree *, int *, void *));
97 static void expand_calls_inline PARAMS ((tree *, inline_data *));
98 static int inlinable_function_p PARAMS ((tree, inline_data *));
99 static tree remap_decl PARAMS ((tree, inline_data *));
100 static void remap_block PARAMS ((tree, tree, inline_data *));
101 static void copy_scope_stmt PARAMS ((tree *, int *, inline_data *));
102 static void optimize_inline_calls PARAMS ((tree));
103 static tree calls_setjmp_r PARAMS ((tree *, int *, void *));
104 static void update_cloned_parm PARAMS ((tree, tree));
105 static void dump_function PARAMS ((enum tree_dump_index, tree));
107 /* The approximate number of instructions per statement. This number
108 need not be particularly accurate; it is used only to make
109 decisions about when a function is too big to inline. */
110 #define INSNS_PER_STMT (10)
112 /* Remap DECL during the copying of the BLOCK tree for the function. */
115 remap_decl (decl, id)
122 /* We only remap local variables in the current function. */
123 fn = VARRAY_TOP_TREE (id->fns);
124 if (!nonstatic_local_decl_p (decl) || DECL_CONTEXT (decl) != fn)
127 /* See if we have remapped this declaration. */
128 n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl);
129 /* If we didn't already have an equivalent for this declaration,
135 /* Make a copy of the variable or label. */
136 t = copy_decl_for_inlining (decl, fn,
137 VARRAY_TREE (id->fns, 0));
139 /* The decl T could be a dynamic array or other variable size type,
140 in which case some fields need to be remapped because they may
141 contain SAVE_EXPRs. */
142 walk_tree (&DECL_SIZE (t), copy_body_r, id, NULL);
143 walk_tree (&DECL_SIZE_UNIT (t), copy_body_r, id, NULL);
144 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE
145 && TYPE_DOMAIN (TREE_TYPE (t)))
147 TREE_TYPE (t) = copy_node (TREE_TYPE (t));
148 TYPE_DOMAIN (TREE_TYPE (t))
149 = copy_node (TYPE_DOMAIN (TREE_TYPE (t)));
150 walk_tree (&TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (t))),
151 copy_body_r, id, NULL);
154 if (!DECL_NAME (t) && TREE_TYPE (t)
155 && ANON_AGGR_TYPE_P (TREE_TYPE ((t))))
157 /* For a VAR_DECL of anonymous type, we must also copy the
158 member VAR_DECLS here and rechain the
159 DECL_ANON_UNION_ELEMS. */
163 for (src = DECL_ANON_UNION_ELEMS (t); src;
164 src = TREE_CHAIN (src))
166 tree member = remap_decl (TREE_VALUE (src), id);
168 my_friendly_assert (!TREE_PURPOSE (src), 20010529);
169 members = tree_cons (NULL, member, members);
171 DECL_ANON_UNION_ELEMS (t) = nreverse (members);
174 /* Remember it, so that if we encounter this local entity
175 again we can reuse this copy. */
176 n = splay_tree_insert (id->decl_map,
177 (splay_tree_key) decl,
178 (splay_tree_value) t);
181 return (tree) n->value;
184 /* Copy the SCOPE_STMT_BLOCK associated with SCOPE_STMT to contain
185 remapped versions of the variables therein. And hook the new block
186 into the block-tree. If non-NULL, the DECLS are declarations to
187 add to use instead of the BLOCK_VARS in the old block. */
190 remap_block (scope_stmt, decls, id)
195 /* We cannot do this in the cleanup for a TARGET_EXPR since we do
196 not know whether or not expand_expr will actually write out the
197 code we put there. If it does not, then we'll have more BLOCKs
198 than block-notes, and things will go awry. At some point, we
199 should make the back-end handle BLOCK notes in a tidier way,
200 without requiring a strict correspondence to the block-tree; then
201 this check can go. */
202 if (id->in_target_cleanup_p)
204 SCOPE_STMT_BLOCK (scope_stmt) = NULL_TREE;
208 /* If this is the beginning of a scope, remap the associated BLOCK. */
209 if (SCOPE_BEGIN_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt))
216 /* Make the new block. */
217 old_block = SCOPE_STMT_BLOCK (scope_stmt);
218 new_block = make_node (BLOCK);
219 TREE_USED (new_block) = TREE_USED (old_block);
220 BLOCK_ABSTRACT_ORIGIN (new_block) = old_block;
221 SCOPE_STMT_BLOCK (scope_stmt) = new_block;
223 /* Remap its variables. */
224 for (old_var = decls ? decls : BLOCK_VARS (old_block);
226 old_var = TREE_CHAIN (old_var))
230 /* Remap the variable. */
231 new_var = remap_decl (old_var, id);
232 /* If we didn't remap this variable, so we can't mess with
233 its TREE_CHAIN. If we remapped this variable to
234 something other than a declaration (say, if we mapped it
235 to a constant), then we must similarly omit any mention
237 if (!new_var || !DECL_P (new_var))
241 TREE_CHAIN (new_var) = BLOCK_VARS (new_block);
242 BLOCK_VARS (new_block) = new_var;
245 /* We put the BLOCK_VARS in reverse order; fix that now. */
246 BLOCK_VARS (new_block) = nreverse (BLOCK_VARS (new_block));
247 fn = VARRAY_TREE (id->fns, 0);
249 /* We're building a clone; DECL_INITIAL is still
250 error_mark_node, and current_binding_level is the parm
252 insert_block (new_block);
255 /* Attach this new block after the DECL_INITIAL block for the
256 function into which this block is being inlined. In
257 rest_of_compilation we will straighten out the BLOCK tree. */
259 if (DECL_INITIAL (fn))
260 first_block = &BLOCK_CHAIN (DECL_INITIAL (fn));
262 first_block = &DECL_INITIAL (fn);
263 BLOCK_CHAIN (new_block) = *first_block;
264 *first_block = new_block;
266 /* Remember the remapped block. */
267 splay_tree_insert (id->decl_map,
268 (splay_tree_key) old_block,
269 (splay_tree_value) new_block);
271 /* If this is the end of a scope, set the SCOPE_STMT_BLOCK to be the
273 else if (SCOPE_END_P (scope_stmt) && SCOPE_STMT_BLOCK (scope_stmt))
277 /* Find this block in the table of remapped things. */
278 n = splay_tree_lookup (id->decl_map,
279 (splay_tree_key) SCOPE_STMT_BLOCK (scope_stmt));
280 my_friendly_assert (n != NULL, 19991203);
281 SCOPE_STMT_BLOCK (scope_stmt) = (tree) n->value;
285 /* Copy the SCOPE_STMT pointed to by TP. */
288 copy_scope_stmt (tp, walk_subtrees, id)
295 /* Remember whether or not this statement was nullified. When
296 making a copy, copy_tree_r always sets SCOPE_NULLIFIED_P (and
297 doesn't copy the SCOPE_STMT_BLOCK) to free callers from having to
298 deal with copying BLOCKs if they do not wish to do so. */
299 block = SCOPE_STMT_BLOCK (*tp);
300 /* Copy (and replace) the statement. */
301 copy_tree_r (tp, walk_subtrees, NULL);
302 /* Restore the SCOPE_STMT_BLOCK. */
303 SCOPE_STMT_BLOCK (*tp) = block;
305 /* Remap the associated block. */
306 remap_block (*tp, NULL_TREE, id);
309 /* Called from copy_body via walk_tree. DATA is really an
313 copy_body_r (tp, walk_subtrees, data)
322 id = (inline_data *) data;
323 fn = VARRAY_TOP_TREE (id->fns);
325 /* All automatic variables should have a DECL_CONTEXT indicating
326 what function they come from. */
327 if ((TREE_CODE (*tp) == VAR_DECL || TREE_CODE (*tp) == LABEL_DECL)
328 && DECL_NAMESPACE_SCOPE_P (*tp))
329 my_friendly_assert (DECL_EXTERNAL (*tp) || TREE_STATIC (*tp),
332 /* If this is a RETURN_STMT, change it into an EXPR_STMT and a
333 GOTO_STMT with the RET_LABEL as its target. */
334 if (TREE_CODE (*tp) == RETURN_STMT && id->ret_label)
336 tree return_stmt = *tp;
339 /* Build the GOTO_STMT. */
340 goto_stmt = build_stmt (GOTO_STMT, id->ret_label);
341 TREE_CHAIN (goto_stmt) = TREE_CHAIN (return_stmt);
343 /* If we're returning something, just turn that into an
344 assignment into the equivalent of the original
346 if (RETURN_EXPR (return_stmt))
348 *tp = build_stmt (EXPR_STMT,
349 RETURN_EXPR (return_stmt));
350 STMT_IS_FULL_EXPR_P (*tp) = 1;
351 /* And then jump to the end of the function. */
352 TREE_CHAIN (*tp) = goto_stmt;
354 /* If we're not returning anything just do the jump. */
358 /* Local variables and labels need to be replaced by equivalent
359 variables. We don't want to copy static variables; there's only
360 one of those, no matter how many times we inline the containing
362 else if (nonstatic_local_decl_p (*tp) && DECL_CONTEXT (*tp) == fn)
366 /* Remap the declaration. */
367 new_decl = remap_decl (*tp, id);
368 my_friendly_assert (new_decl != NULL_TREE, 19991203);
369 /* Replace this variable with the copy. */
370 STRIP_TYPE_NOPS (new_decl);
373 else if (nonstatic_local_decl_p (*tp)
374 && DECL_CONTEXT (*tp) != VARRAY_TREE (id->fns, 0))
375 my_friendly_abort (0);
376 else if (TREE_CODE (*tp) == SAVE_EXPR)
377 remap_save_expr (tp, id->decl_map, VARRAY_TREE (id->fns, 0),
379 else if (TREE_CODE (*tp) == UNSAVE_EXPR)
380 /* UNSAVE_EXPRs should not be generated until expansion time. */
381 my_friendly_abort (19991113);
382 /* For a SCOPE_STMT, we must copy the associated block so that we
383 can write out debugging information for the inlined variables. */
384 else if (TREE_CODE (*tp) == SCOPE_STMT && !id->in_target_cleanup_p)
385 copy_scope_stmt (tp, walk_subtrees, id);
386 /* Otherwise, just copy the node. Note that copy_tree_r already
387 knows not to copy VAR_DECLs, etc., so this is safe. */
390 copy_tree_r (tp, walk_subtrees, NULL);
392 /* The copied TARGET_EXPR has never been expanded, even if the
393 original node was expanded already. */
394 if (TREE_CODE (*tp) == TARGET_EXPR && TREE_OPERAND (*tp, 3))
396 TREE_OPERAND (*tp, 1) = TREE_OPERAND (*tp, 3);
397 TREE_OPERAND (*tp, 3) = NULL_TREE;
399 else if (TREE_CODE (*tp) == MODIFY_EXPR
400 && TREE_OPERAND (*tp, 0) == TREE_OPERAND (*tp, 1)
401 && nonstatic_local_decl_p (TREE_OPERAND (*tp, 0))
402 && DECL_CONTEXT (TREE_OPERAND (*tp, 0)) == fn)
404 /* Some assignments VAR = VAR; don't generate any rtl code
405 and thus don't count as variable modification. Avoid
406 keeping bogosities like 0 = 0. */
407 tree decl = TREE_OPERAND (*tp, 0), value;
410 n = splay_tree_lookup (id->decl_map, (splay_tree_key) decl);
413 value = (tree) n->value;
414 STRIP_TYPE_NOPS (value);
415 if (TREE_CONSTANT (value) || TREE_READONLY_DECL_P (value))
421 /* Keep iterating. */
425 /* Make a copy of the body of FN so that it can be inserted inline in
434 body = DECL_SAVED_TREE (VARRAY_TOP_TREE (id->fns));
435 walk_tree (&body, copy_body_r, id, NULL);
440 /* Generate code to initialize the parameters of the function at the
441 top of the stack in ID from the ARGS (presented as a TREE_LIST). */
444 initialize_inlined_parameters (id, args, fn)
454 /* Figure out what the parameters are. */
455 parms = DECL_ARGUMENTS (fn);
457 /* Start with no initializations whatsoever. */
458 init_stmts = NULL_TREE;
460 /* Loop through the parameter declarations, replacing each with an
461 equivalent VAR_DECL, appropriately initialized. */
462 for (p = parms, a = args; p; a = TREE_CHAIN (a), p = TREE_CHAIN (p))
468 /* Find the initializer. */
469 value = TREE_VALUE (a);
470 /* If the parameter is never assigned to, we may not need to
471 create a new variable here at all. Instead, we may be able
472 to just use the argument value. */
473 if (TREE_READONLY (p)
474 && !TREE_ADDRESSABLE (p)
475 && !TREE_SIDE_EFFECTS (value))
477 /* Simplify the value, if possible. */
478 value = fold (decl_constant_value (value));
480 /* We can't risk substituting complex expressions. They
481 might contain variables that will be assigned to later.
482 Theoretically, we could check the expression to see if
483 all of the variables that determine its value are
484 read-only, but we don't bother. */
485 if (TREE_CONSTANT (value) || TREE_READONLY_DECL_P (value))
487 /* If this is a declaration, wrap it a NOP_EXPR so that
488 we don't try to put the VALUE on the list of
491 value = build1 (NOP_EXPR, TREE_TYPE (value), value);
493 splay_tree_insert (id->decl_map,
495 (splay_tree_value) value);
500 /* Make an equivalent VAR_DECL. */
501 var = copy_decl_for_inlining (p, fn, VARRAY_TREE (id->fns, 0));
502 /* Register the VAR_DECL as the equivalent for the PARM_DECL;
503 that way, when the PARM_DECL is encountered, it will be
504 automatically replaced by the VAR_DECL. */
505 splay_tree_insert (id->decl_map,
507 (splay_tree_value) var);
509 /* Declare this new variable. */
510 init_stmt = build_stmt (DECL_STMT, var);
511 TREE_CHAIN (init_stmt) = init_stmts;
512 init_stmts = init_stmt;
514 /* Initialize this VAR_DECL from the equivalent argument. If
515 the argument is an object, created via a constructor or copy,
516 this will not result in an extra copy: the TARGET_EXPR
517 representing the argument will be bound to VAR, and the
518 object will be constructed in VAR. */
519 if (! TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (p)))
520 DECL_INITIAL (var) = value;
523 /* Even if P was TREE_READONLY, the new VAR should not be.
524 In the original code, we would have constructed a
525 temporary, and then the function body would have never
526 changed the value of P. However, now, we will be
527 constructing VAR directly. The constructor body may
528 change its value multiple times as it is being
529 constructed. Therefore, it must not be TREE_READONLY;
530 the back-end assumes that TREE_READONLY variable is
531 assigned to only once. */
532 TREE_READONLY (var) = 0;
534 /* Build a run-time initialization. */
535 init_stmt = build_stmt (EXPR_STMT,
536 build (INIT_EXPR, TREE_TYPE (p),
538 /* Add this initialization to the list. Note that we want the
539 declaration *after* the initialization because we are going
540 to reverse all the initialization statements below. */
541 TREE_CHAIN (init_stmt) = init_stmts;
542 init_stmts = init_stmt;
546 /* The initialization statements have been built up in reverse
547 order. Straighten them out now. */
548 return nreverse (init_stmts);
551 /* Declare a return variable to replace the RESULT_DECL for the
552 function we are calling. An appropriate DECL_STMT is returned.
553 The USE_STMT is filled in to contain a use of the declaration to
554 indicate the return value of the function. */
557 declare_return_variable (id, use_stmt)
558 struct inline_data *id;
561 tree fn = VARRAY_TOP_TREE (id->fns);
562 tree result = DECL_RESULT (fn);
564 int aggregate_return_p;
566 /* We don't need to do anything for functions that don't return
568 if (!result || VOID_TYPE_P (TREE_TYPE (result)))
570 *use_stmt = NULL_TREE;
574 /* Figure out whether or not FN returns an aggregate. */
575 aggregate_return_p = IS_AGGR_TYPE (TREE_TYPE (result));
577 /* If FN returns an aggregate then the caller will always create the
578 temporary (using a TARGET_EXPR) and the call will be the
579 initializing expression for the TARGET_EXPR. If we were just to
580 create a new VAR_DECL here, then the result of this function
581 would be copied (bitwise) into the variable initialized by the
582 TARGET_EXPR. That's incorrect, so we must transform any
583 references to the RESULT into references to the target. */
584 if (aggregate_return_p)
586 my_friendly_assert (VARRAY_ACTIVE_SIZE (id->target_exprs) != 0,
588 var = TREE_OPERAND (VARRAY_TOP_TREE (id->target_exprs), 0);
590 (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (var),
594 /* Otherwise, make an appropriate copy. */
596 var = copy_decl_for_inlining (result, fn, VARRAY_TREE (id->fns, 0));
598 /* Register the VAR_DECL as the equivalent for the RESULT_DECL; that
599 way, when the RESULT_DECL is encountered, it will be
600 automatically replaced by the VAR_DECL. */
601 splay_tree_insert (id->decl_map,
602 (splay_tree_key) result,
603 (splay_tree_value) var);
605 if (DECL_SAVED_FUNCTION_DATA (fn))
607 tree nrv = DECL_SAVED_FUNCTION_DATA (fn)->x_return_value;
610 /* We have a named return value; copy the name and source
611 position so we can get reasonable debugging information, and
612 register the return variable as its equivalent. */
613 DECL_NAME (var) = DECL_NAME (nrv);
614 DECL_SOURCE_FILE (var) = DECL_SOURCE_FILE (nrv);
615 DECL_SOURCE_LINE (var) = DECL_SOURCE_LINE (nrv);
616 splay_tree_insert (id->decl_map,
617 (splay_tree_key) nrv,
618 (splay_tree_value) var);
622 /* Build the USE_STMT. */
623 *use_stmt = build_stmt (EXPR_STMT, var);
625 /* Build the declaration statement if FN does not return an
627 if (!aggregate_return_p)
628 return build_stmt (DECL_STMT, var);
629 /* If FN does return an aggregate, there's no need to declare the
630 return variable; we're using a variable in our caller's frame. */
635 /* Returns non-zero if FN is a function that can be inlined. */
638 inlinable_function_p (fn, id)
644 /* If we've already decided this function shouldn't be inlined,
645 there's no need to check again. */
646 if (DECL_UNINLINABLE (fn))
649 /* Assume it is not inlinable. */
652 /* If we're not inlining things, then nothing is inlinable. */
653 if (!flag_inline_trees)
655 /* If the function was not declared `inline', then we don't inline
657 else if (!DECL_INLINE (fn))
659 /* We can't inline varargs functions. */
660 else if (varargs_function_p (fn))
662 /* We can't inline functions that are too big.
663 * Only allow a single function to eat up half of our budget. */
664 else if (DECL_NUM_STMTS (fn) * INSNS_PER_STMT > MAX_INLINE_INSNS / 2)
666 /* All is well. We can inline this function. Traditionally, GCC
667 has refused to inline functions using alloca, or functions whose
668 values are returned in a PARALLEL, and a few other such obscure
669 conditions. We are not equally constrained at the tree level. */
673 /* Squirrel away the result so that we don't have to check again. */
674 DECL_UNINLINABLE (fn) = !inlinable;
676 /* Even if this function is not itself too big to inline, it might
677 be that we've done so much inlining already that we don't want to
678 risk too much inlining any more and thus halve the acceptable size. */
679 if ((DECL_NUM_STMTS (fn) + id->inlined_stmts) * INSNS_PER_STMT
681 && DECL_NUM_STMTS (fn) * INSNS_PER_STMT > MAX_INLINE_INSNS / 4)
684 /* We can inline a template instantiation only if it's fully
687 && DECL_TEMPLATE_INFO (fn)
688 && TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (fn)))
690 fn = instantiate_decl (fn, /*defer_ok=*/0);
691 inlinable = !TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (fn));
694 /* If we don't have the function body available, we can't inline
696 if (!DECL_SAVED_TREE (fn))
699 /* Don't do recursive inlining, either. We don't record this in
700 DECL_UNINLINABLE; we may be able to inline this function later. */
705 for (i = 0; i < VARRAY_ACTIVE_SIZE (id->fns); ++i)
706 if (VARRAY_TREE (id->fns, i) == fn)
709 if (inlinable && DECL_LANG_SPECIFIC (fn) && DECL_INLINED_FNS (fn))
712 tree inlined_fns = DECL_INLINED_FNS (fn);
714 for (j = 0; j < TREE_VEC_LENGTH (inlined_fns); ++j)
715 if (TREE_VEC_ELT (inlined_fns, j) == VARRAY_TREE (id->fns, 0))
720 /* Return the result. */
724 /* If *TP is a CALL_EXPR, replace it with its inline expansion. */
727 expand_call_inline (tp, walk_subtrees, data)
743 /* See what we've got. */
744 id = (inline_data *) data;
747 /* Recurse, but letting recursive invocations know that we are
748 inside the body of a TARGET_EXPR. */
749 if (TREE_CODE (*tp) == TARGET_EXPR)
751 int i, len = first_rtl_op (TARGET_EXPR);
753 /* We're walking our own subtrees. */
756 /* Push *TP on the stack of pending TARGET_EXPRs. */
757 VARRAY_PUSH_TREE (id->target_exprs, *tp);
759 /* Actually walk over them. This loop is the body of
760 walk_trees, omitting the case where the TARGET_EXPR
761 itself is handled. */
762 for (i = 0; i < len; ++i)
765 ++id->in_target_cleanup_p;
766 walk_tree (&TREE_OPERAND (*tp, i), expand_call_inline, data,
769 --id->in_target_cleanup_p;
772 /* We're done with this TARGET_EXPR now. */
773 VARRAY_POP (id->target_exprs);
779 /* Because types were not copied in copy_body, CALL_EXPRs beneath
780 them should not be expanded. This can happen if the type is a
781 dynamic array type, for example. */
784 /* From here on, we're only interested in CALL_EXPRs. */
785 if (TREE_CODE (t) != CALL_EXPR)
788 /* First, see if we can figure out what function is being called.
789 If we cannot, then there is no hope of inlining the function. */
790 fn = get_callee_fndecl (t);
794 /* Don't try to inline functions that are not well-suited to
796 if (!inlinable_function_p (fn, id))
799 /* Set the current filename and line number to the function we are
800 inlining so that when we create new _STMT nodes here they get
801 line numbers corresponding to the function we are calling. We
802 wrap the whole inlined body in an EXPR_WITH_FILE_AND_LINE as well
803 because individual statements don't record the filename. */
804 push_srcloc (fn->decl.filename, fn->decl.linenum);
806 /* Build a statement-expression containing code to initialize the
807 arguments, the actual inline expansion of the body, and a label
808 for the return statements within the function to jump to. The
809 type of the statement expression is the return type of the
811 expr = build_min (STMT_EXPR, TREE_TYPE (TREE_TYPE (fn)), NULL_TREE);
813 /* Local declarations will be replaced by their equivalents in this
816 id->decl_map = splay_tree_new (splay_tree_compare_pointers,
819 /* Initialize the parameters. */
820 arg_inits = initialize_inlined_parameters (id, TREE_OPERAND (t, 1), fn);
821 /* Expand any inlined calls in the initializers. Do this before we
822 push FN on the stack of functions we are inlining; we want to
823 inline calls to FN that appear in the initializers for the
825 expand_calls_inline (&arg_inits, id);
826 /* And add them to the tree. */
827 STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), arg_inits);
829 /* Record the function we are about to inline so that we can avoid
830 recursing into it. */
831 VARRAY_PUSH_TREE (id->fns, fn);
833 /* Record the function we are about to inline if optimize_function
834 has not been called on it yet and we don't have it in the list. */
835 if (DECL_LANG_SPECIFIC (fn) && !DECL_INLINED_FNS (fn))
839 for (i = VARRAY_ACTIVE_SIZE (id->inlined_fns) - 1; i >= 0; i--)
840 if (VARRAY_TREE (id->inlined_fns, i) == fn)
843 VARRAY_PUSH_TREE (id->inlined_fns, fn);
846 /* Return statements in the function body will be replaced by jumps
848 id->ret_label = build_decl (LABEL_DECL, NULL_TREE, NULL_TREE);
849 DECL_CONTEXT (id->ret_label) = VARRAY_TREE (id->fns, 0);
851 /* Create a block to put the parameters in. We have to do this
852 after the parameters have been remapped because remapping
853 parameters is different from remapping ordinary variables. */
854 scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
855 SCOPE_BEGIN_P (scope_stmt) = 1;
856 SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
857 remap_block (scope_stmt, DECL_ARGUMENTS (fn), id);
858 TREE_CHAIN (scope_stmt) = STMT_EXPR_STMT (expr);
859 STMT_EXPR_STMT (expr) = scope_stmt;
861 /* Tell the debugging backends that this block represents the
862 outermost scope of the inlined function. */
863 if (SCOPE_STMT_BLOCK (scope_stmt))
864 BLOCK_ABSTRACT_ORIGIN (SCOPE_STMT_BLOCK (scope_stmt)) = DECL_ORIGIN (fn);
866 /* Declare the return variable for the function. */
867 STMT_EXPR_STMT (expr)
868 = chainon (STMT_EXPR_STMT (expr),
869 declare_return_variable (id, &use_stmt));
871 /* After we've initialized the parameters, we insert the body of the
873 inlined_body = &STMT_EXPR_STMT (expr);
874 while (*inlined_body)
875 inlined_body = &TREE_CHAIN (*inlined_body);
876 *inlined_body = copy_body (id);
878 /* Close the block for the parameters. */
879 scope_stmt = build_stmt (SCOPE_STMT, DECL_INITIAL (fn));
880 SCOPE_NO_CLEANUPS_P (scope_stmt) = 1;
881 my_friendly_assert (DECL_INITIAL (fn)
882 && TREE_CODE (DECL_INITIAL (fn)) == BLOCK,
884 remap_block (scope_stmt, NULL_TREE, id);
885 STMT_EXPR_STMT (expr)
886 = chainon (STMT_EXPR_STMT (expr), scope_stmt);
888 /* After the body of the function comes the RET_LABEL. This must come
889 before we evaluate the returned value below, because that evalulation
890 may cause RTL to be generated. */
891 STMT_EXPR_STMT (expr)
892 = chainon (STMT_EXPR_STMT (expr),
893 build_stmt (LABEL_STMT, id->ret_label));
895 /* Finally, mention the returned value so that the value of the
896 statement-expression is the returned value of the function. */
897 STMT_EXPR_STMT (expr) = chainon (STMT_EXPR_STMT (expr), use_stmt);
900 splay_tree_delete (id->decl_map);
903 /* The new expression has side-effects if the old one did. */
904 TREE_SIDE_EFFECTS (expr) = TREE_SIDE_EFFECTS (t);
906 /* Replace the call by the inlined body. Wrap it in an
907 EXPR_WITH_FILE_LOCATION so that we'll get debugging line notes
908 pointing to the right place. */
909 chain = TREE_CHAIN (*tp);
910 *tp = build_expr_wfl (expr, DECL_SOURCE_FILE (fn), DECL_SOURCE_LINE (fn),
912 EXPR_WFL_EMIT_LINE_NOTE (*tp) = 1;
913 TREE_CHAIN (*tp) = chain;
916 /* If the value of the new expression is ignored, that's OK. We
917 don't warn about this for CALL_EXPRs, so we shouldn't warn about
918 the equivalent inlined version either. */
921 /* Our function now has more statements than it did before. */
922 DECL_NUM_STMTS (VARRAY_TREE (id->fns, 0)) += DECL_NUM_STMTS (fn);
923 id->inlined_stmts += DECL_NUM_STMTS (fn);
925 /* Recurse into the body of the just inlined function. */
926 expand_calls_inline (inlined_body, id);
927 VARRAY_POP (id->fns);
929 /* If we've returned to the top level, clear out the record of how
930 much inlining has been done. */
931 if (VARRAY_ACTIVE_SIZE (id->fns) == id->first_inlined_fn)
932 id->inlined_stmts = 0;
934 /* Don't walk into subtrees. We've already handled them above. */
937 /* Keep iterating. */
941 /* Walk over the entire tree *TP, replacing CALL_EXPRs with inline
942 expansions as appropriate. */
945 expand_calls_inline (tp, id)
949 /* Search through *TP, replacing all calls to inline functions by
950 appropriate equivalents. Use walk_tree in no-duplicates mode
951 to avoid exponential time complexity. (We can't just use
952 walk_tree_without_duplicates, because of the special TARGET_EXPR
953 handling in expand_calls. The hash table is set up in
954 optimize_function. */
955 walk_tree (tp, expand_call_inline, id, id->tree_pruner);
958 /* Expand calls to inline functions in the body of FN. */
961 optimize_inline_calls (fn)
966 struct saved_scope *s;
969 memset (&id, 0, sizeof (id));
971 /* Don't allow recursion into FN. */
972 VARRAY_TREE_INIT (id.fns, 32, "fns");
973 VARRAY_PUSH_TREE (id.fns, fn);
974 /* Or any functions that aren't finished yet. */
976 if (current_function_decl)
978 VARRAY_PUSH_TREE (id.fns, current_function_decl);
979 prev_fn = current_function_decl;
981 for (s = scope_chain; s; s = s->prev)
982 if (s->function_decl && s->function_decl != prev_fn)
984 VARRAY_PUSH_TREE (id.fns, s->function_decl);
985 prev_fn = s->function_decl;
988 /* Create the stack of TARGET_EXPRs. */
989 VARRAY_TREE_INIT (id.target_exprs, 32, "target_exprs");
991 /* Create the list of functions this call will inline. */
992 VARRAY_TREE_INIT (id.inlined_fns, 32, "inlined_fns");
994 /* Keep track of the low-water mark, i.e., the point where the first
995 real inlining is represented in ID.FNS. */
996 id.first_inlined_fn = VARRAY_ACTIVE_SIZE (id.fns);
998 /* Replace all calls to inline functions with the bodies of those
1000 id.tree_pruner = htab_create (37, htab_hash_pointer,
1001 htab_eq_pointer, NULL);
1002 expand_calls_inline (&DECL_SAVED_TREE (fn), &id);
1005 htab_delete (id.tree_pruner);
1006 VARRAY_FREE (id.fns);
1007 VARRAY_FREE (id.target_exprs);
1008 if (DECL_LANG_SPECIFIC (fn))
1010 tree ifn = make_tree_vec (VARRAY_ACTIVE_SIZE (id.inlined_fns));
1012 memcpy (&TREE_VEC_ELT (ifn, 0), &VARRAY_TREE (id.inlined_fns, 0),
1013 VARRAY_ACTIVE_SIZE (id.inlined_fns) * sizeof (tree));
1014 DECL_INLINED_FNS (fn) = ifn;
1016 VARRAY_FREE (id.inlined_fns);
1018 dump_function (TDI_inlined, fn);
1021 /* Optimize the body of FN. */
1024 optimize_function (fn)
1027 dump_function (TDI_original, fn);
1029 /* While in this function, we may choose to go off and compile
1030 another function. For example, we might instantiate a function
1031 in the hopes of inlining it. Normally, that wouldn't trigger any
1032 actual RTL code-generation -- but it will if the template is
1033 actually needed. (For example, if it's address is taken, or if
1034 some other function already refers to the template.) If
1035 code-generation occurs, then garbage collection will occur, so we
1036 must protect ourselves, just as we do while building up the body
1040 if (flag_inline_trees
1041 /* We do not inline thunks, as (a) the backend tries to optimize
1042 the call to the thunkee, (b) tree based inlining breaks that
1043 optimization, (c) virtual functions are rarely inlineable,
1044 and (d) ASM_OUTPUT_MI_THUNK is there to DTRT anyway. */
1045 && !DECL_THUNK_P (fn))
1046 optimize_inline_calls (fn);
1048 /* Undo the call to ggc_push_context above. */
1051 dump_function (TDI_optimized, fn);
1054 /* Called from calls_setjmp_p via walk_tree. */
1057 calls_setjmp_r (tp, walk_subtrees, data)
1059 int *walk_subtrees ATTRIBUTE_UNUSED;
1060 void *data ATTRIBUTE_UNUSED;
1062 /* We're only interested in FUNCTION_DECLS. */
1063 if (TREE_CODE (*tp) != FUNCTION_DECL)
1066 return setjmp_call_p (*tp) ? *tp : NULL_TREE;
1069 /* Returns non-zero if FN calls `setjmp' or some other function that
1070 can return more than once. This function is conservative; it may
1071 occasionally return a non-zero value even when FN does not actually
1078 return walk_tree_without_duplicates (&DECL_SAVED_TREE (fn),
1083 /* CLONED_PARM is a copy of CLONE, generated for a cloned constructor
1084 or destructor. Update it to ensure that the source-position for
1085 the cloned parameter matches that for the original, and that the
1086 debugging generation code will be able to find the original PARM. */
1089 update_cloned_parm (parm, cloned_parm)
1093 DECL_ABSTRACT_ORIGIN (cloned_parm) = parm;
1095 /* We may have taken its address. */
1096 TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm);
1098 /* The definition might have different constness. */
1099 TREE_READONLY (cloned_parm) = TREE_READONLY (parm);
1101 TREE_USED (cloned_parm) = TREE_USED (parm);
1103 /* The name may have changed from the declaration. */
1104 DECL_NAME (cloned_parm) = DECL_NAME (parm);
1105 DECL_SOURCE_FILE (cloned_parm) = DECL_SOURCE_FILE (parm);
1106 DECL_SOURCE_LINE (cloned_parm) = DECL_SOURCE_LINE (parm);
1109 /* FN is a function that has a complete body. Clone the body as
1110 necessary. Returns non-zero if there's no longer any need to
1111 process the main body. */
1114 maybe_clone_body (fn)
1121 /* We only clone constructors and destructors. */
1122 if (!DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)
1123 && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn))
1126 /* Emit the DWARF1 abstract instance. */
1127 (*debug_hooks->deferred_inline_function) (fn);
1129 /* We know that any clones immediately follow FN in the TYPE_METHODS
1131 for (clone = TREE_CHAIN (fn);
1132 clone && DECL_CLONED_FUNCTION_P (clone);
1133 clone = TREE_CHAIN (clone), first = 0)
1139 /* Update CLONE's source position information to match FN's. */
1140 DECL_SOURCE_FILE (clone) = DECL_SOURCE_FILE (fn);
1141 DECL_SOURCE_LINE (clone) = DECL_SOURCE_LINE (fn);
1142 DECL_INLINE (clone) = DECL_INLINE (fn);
1143 DECL_DECLARED_INLINE_P (clone) = DECL_DECLARED_INLINE_P (fn);
1144 DECL_COMDAT (clone) = DECL_COMDAT (fn);
1145 DECL_WEAK (clone) = DECL_WEAK (fn);
1146 DECL_ONE_ONLY (clone) = DECL_ONE_ONLY (fn);
1147 DECL_SECTION_NAME (clone) = DECL_SECTION_NAME (fn);
1148 DECL_USE_TEMPLATE (clone) = DECL_USE_TEMPLATE (fn);
1149 DECL_EXTERNAL (clone) = DECL_EXTERNAL (fn);
1150 DECL_INTERFACE_KNOWN (clone) = DECL_INTERFACE_KNOWN (fn);
1151 DECL_NOT_REALLY_EXTERN (clone) = DECL_NOT_REALLY_EXTERN (fn);
1152 TREE_PUBLIC (clone) = TREE_PUBLIC (fn);
1154 /* Adjust the parameter names and locations. */
1155 parm = DECL_ARGUMENTS (fn);
1156 clone_parm = DECL_ARGUMENTS (clone);
1157 /* Update the `this' parameter, which is always first.
1158 Sometimes, we end update the `this' parameter twice because
1159 we process it again in the loop below. That is harmless. */
1160 update_cloned_parm (parm, clone_parm);
1161 if (DECL_HAS_IN_CHARGE_PARM_P (fn))
1162 parm = TREE_CHAIN (parm);
1163 if (DECL_HAS_VTT_PARM_P (fn))
1164 parm = TREE_CHAIN (parm);
1165 if (DECL_HAS_VTT_PARM_P (clone))
1166 clone_parm = TREE_CHAIN (clone_parm);
1168 parm = TREE_CHAIN (parm), clone_parm = TREE_CHAIN (clone_parm))
1170 /* Update this paramter. */
1171 update_cloned_parm (parm, clone_parm);
1172 /* We should only give unused information for one clone. */
1174 TREE_USED (clone_parm) = 1;
1177 /* Start processing the function. */
1178 push_to_top_level ();
1179 start_function (NULL_TREE, clone, NULL_TREE, SF_PRE_PARSED);
1181 /* Just clone the body, as if we were making an inline call.
1182 But, remap the parameters in the callee to the parameters of
1183 caller. If there's an in-charge parameter, map it to an
1184 appropriate constant. */
1185 memset (&id, 0, sizeof (id));
1186 VARRAY_TREE_INIT (id.fns, 2, "fns");
1187 VARRAY_PUSH_TREE (id.fns, clone);
1188 VARRAY_PUSH_TREE (id.fns, fn);
1190 /* Cloning is treated slightly differently from inlining. Set
1191 CLONING_P so that its clear which operation we're performing. */
1192 id.cloning_p = true;
1194 /* Remap the parameters. */
1195 id.decl_map = splay_tree_new (splay_tree_compare_pointers,
1198 parm = DECL_ARGUMENTS (fn),
1199 clone_parm = DECL_ARGUMENTS (clone);
1202 parm = TREE_CHAIN (parm))
1204 /* Map the in-charge parameter to an appropriate constant. */
1205 if (DECL_HAS_IN_CHARGE_PARM_P (fn) && parmno == 1)
1208 in_charge = in_charge_arg_for_name (DECL_NAME (clone));
1209 splay_tree_insert (id.decl_map,
1210 (splay_tree_key) parm,
1211 (splay_tree_value) in_charge);
1213 else if (DECL_ARTIFICIAL (parm)
1214 && DECL_NAME (parm) == vtt_parm_identifier)
1216 /* For a subobject constructor or destructor, the next
1217 argument is the VTT parameter. Remap the VTT_PARM
1218 from the CLONE to this parameter. */
1219 if (DECL_HAS_VTT_PARM_P (clone))
1221 DECL_ABSTRACT_ORIGIN (clone_parm) = parm;
1222 splay_tree_insert (id.decl_map,
1223 (splay_tree_key) parm,
1224 (splay_tree_value) clone_parm);
1225 clone_parm = TREE_CHAIN (clone_parm);
1227 /* Otherwise, map the VTT parameter to `NULL'. */
1230 splay_tree_insert (id.decl_map,
1231 (splay_tree_key) parm,
1232 (splay_tree_value) null_pointer_node);
1235 /* Map other parameters to their equivalents in the cloned
1239 splay_tree_insert (id.decl_map,
1240 (splay_tree_key) parm,
1241 (splay_tree_value) clone_parm);
1242 clone_parm = TREE_CHAIN (clone_parm);
1246 /* Actually copy the body. */
1247 TREE_CHAIN (DECL_SAVED_TREE (clone)) = copy_body (&id);
1249 /* There are as many statements in the clone as in the
1251 DECL_NUM_STMTS (clone) = DECL_NUM_STMTS (fn);
1254 splay_tree_delete (id.decl_map);
1255 VARRAY_FREE (id.fns);
1257 /* Now, expand this function into RTL, if appropriate. */
1258 finish_function (0);
1259 BLOCK_ABSTRACT_ORIGIN (DECL_INITIAL (clone)) = DECL_INITIAL (fn);
1260 expand_body (clone);
1261 pop_from_top_level ();
1264 /* We don't need to process the original function any further. */
1268 /* Dump FUNCTION_DECL FN as tree dump PHASE. */
1271 dump_function (phase, fn)
1272 enum tree_dump_index phase;
1278 stream = dump_begin (phase, &flags);
1281 fprintf (stream, "\n;; Function %s",
1282 decl_as_string (fn, TFF_DECL_SPECIFIERS));
1283 fprintf (stream, " (%s)\n",
1284 decl_as_string (DECL_ASSEMBLER_NAME (fn), 0));
1285 fprintf (stream, ";; enabled by -%s\n", dump_flag_name (phase));
1286 fprintf (stream, "\n");
1288 dump_node (fn, TDF_SLIM | flags, stream);
1289 dump_end (phase, stream);