1 /* Perform optimizations on tree structure.
2 Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
3 Written by Mark Michell (mark@codesourcery.com).
5 This file is part of GCC.
7 GCC 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 GCC 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 GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
29 #include "insn-config.h"
31 #include "integrate.h"
37 #include "tree-inline.h"
41 static tree calls_setjmp_r (tree *, int *, void *);
42 static void update_cloned_parm (tree, tree);
43 static void dump_function (enum tree_dump_index, tree);
45 /* Optimize the body of FN. */
48 optimize_function (tree fn)
50 dump_function (TDI_original, fn);
52 /* While in this function, we may choose to go off and compile
53 another function. For example, we might instantiate a function
54 in the hopes of inlining it. Normally, that wouldn't trigger any
55 actual RTL code-generation -- but it will if the template is
56 actually needed. (For example, if it's address is taken, or if
57 some other function already refers to the template.) If
58 code-generation occurs, then garbage collection will occur, so we
59 must protect ourselves, just as we do while building up the body
64 /* We do not inline thunks, as (a) the backend tries to optimize
65 the call to the thunkee, (b) tree based inlining breaks that
66 optimization, (c) virtual functions are rarely inlineable,
67 and (d) TARGET_ASM_OUTPUT_MI_THUNK is there to DTRT anyway. */
68 && !DECL_THUNK_P (fn))
70 optimize_inline_calls (fn);
72 dump_function (TDI_inlined, fn);
75 /* Undo the call to ggc_push_context above. */
78 dump_function (TDI_optimized, fn);
81 /* Called from calls_setjmp_p via walk_tree. */
84 calls_setjmp_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
85 void *data ATTRIBUTE_UNUSED)
87 /* We're only interested in FUNCTION_DECLS. */
88 if (TREE_CODE (*tp) != FUNCTION_DECL)
91 return setjmp_call_p (*tp) ? *tp : NULL_TREE;
94 /* Returns nonzero if FN calls `setjmp' or some other function that
95 can return more than once. This function is conservative; it may
96 occasionally return a nonzero value even when FN does not actually
100 calls_setjmp_p (tree fn)
102 return walk_tree_without_duplicates (&DECL_SAVED_TREE (fn),
107 /* CLONED_PARM is a copy of CLONE, generated for a cloned constructor
108 or destructor. Update it to ensure that the source-position for
109 the cloned parameter matches that for the original, and that the
110 debugging generation code will be able to find the original PARM. */
113 update_cloned_parm (tree parm, tree cloned_parm)
115 DECL_ABSTRACT_ORIGIN (cloned_parm) = parm;
117 /* We may have taken its address. */
118 TREE_ADDRESSABLE (cloned_parm) = TREE_ADDRESSABLE (parm);
120 /* The definition might have different constness. */
121 TREE_READONLY (cloned_parm) = TREE_READONLY (parm);
123 TREE_USED (cloned_parm) = TREE_USED (parm);
125 /* The name may have changed from the declaration. */
126 DECL_NAME (cloned_parm) = DECL_NAME (parm);
127 DECL_SOURCE_LOCATION (cloned_parm) = DECL_SOURCE_LOCATION (parm);
130 /* FN is a function that has a complete body. Clone the body as
131 necessary. Returns nonzero if there's no longer any need to
132 process the main body. */
135 maybe_clone_body (tree fn)
140 /* We only clone constructors and destructors. */
141 if (!DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn)
142 && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn))
145 /* Emit the DWARF1 abstract instance. */
146 (*debug_hooks->deferred_inline_function) (fn);
148 /* We know that any clones immediately follow FN in the TYPE_METHODS
150 for (clone = TREE_CHAIN (fn);
151 clone && DECL_CLONED_FUNCTION_P (clone);
152 clone = TREE_CHAIN (clone), first = false)
159 /* Update CLONE's source position information to match FN's. */
160 DECL_SOURCE_LOCATION (clone) = DECL_SOURCE_LOCATION (fn);
161 DECL_INLINE (clone) = DECL_INLINE (fn);
162 DECL_DECLARED_INLINE_P (clone) = DECL_DECLARED_INLINE_P (fn);
163 DECL_COMDAT (clone) = DECL_COMDAT (fn);
164 DECL_WEAK (clone) = DECL_WEAK (fn);
165 DECL_ONE_ONLY (clone) = DECL_ONE_ONLY (fn);
166 DECL_SECTION_NAME (clone) = DECL_SECTION_NAME (fn);
167 DECL_USE_TEMPLATE (clone) = DECL_USE_TEMPLATE (fn);
168 DECL_EXTERNAL (clone) = DECL_EXTERNAL (fn);
169 DECL_INTERFACE_KNOWN (clone) = DECL_INTERFACE_KNOWN (fn);
170 DECL_NOT_REALLY_EXTERN (clone) = DECL_NOT_REALLY_EXTERN (fn);
171 TREE_PUBLIC (clone) = TREE_PUBLIC (fn);
173 /* Adjust the parameter names and locations. */
174 parm = DECL_ARGUMENTS (fn);
175 clone_parm = DECL_ARGUMENTS (clone);
176 /* Update the `this' parameter, which is always first. */
177 update_cloned_parm (parm, clone_parm);
178 parm = TREE_CHAIN (parm);
179 clone_parm = TREE_CHAIN (clone_parm);
180 if (DECL_HAS_IN_CHARGE_PARM_P (fn))
181 parm = TREE_CHAIN (parm);
182 if (DECL_HAS_VTT_PARM_P (fn))
183 parm = TREE_CHAIN (parm);
184 if (DECL_HAS_VTT_PARM_P (clone))
185 clone_parm = TREE_CHAIN (clone_parm);
187 parm = TREE_CHAIN (parm), clone_parm = TREE_CHAIN (clone_parm))
189 /* Update this parameter. */
190 update_cloned_parm (parm, clone_parm);
191 /* We should only give unused information for one clone. */
193 TREE_USED (clone_parm) = 1;
196 /* Start processing the function. */
197 push_to_top_level ();
198 start_function (NULL_TREE, clone, NULL_TREE, SF_PRE_PARSED);
200 /* Remap the parameters. */
201 decl_map = splay_tree_new (splay_tree_compare_pointers, NULL, NULL);
203 parm = DECL_ARGUMENTS (fn),
204 clone_parm = DECL_ARGUMENTS (clone);
207 parm = TREE_CHAIN (parm))
209 /* Map the in-charge parameter to an appropriate constant. */
210 if (DECL_HAS_IN_CHARGE_PARM_P (fn) && parmno == 1)
213 in_charge = in_charge_arg_for_name (DECL_NAME (clone));
214 splay_tree_insert (decl_map,
215 (splay_tree_key) parm,
216 (splay_tree_value) in_charge);
218 else if (DECL_ARTIFICIAL (parm)
219 && DECL_NAME (parm) == vtt_parm_identifier)
221 /* For a subobject constructor or destructor, the next
222 argument is the VTT parameter. Remap the VTT_PARM
223 from the CLONE to this parameter. */
224 if (DECL_HAS_VTT_PARM_P (clone))
226 DECL_ABSTRACT_ORIGIN (clone_parm) = parm;
227 splay_tree_insert (decl_map,
228 (splay_tree_key) parm,
229 (splay_tree_value) clone_parm);
230 clone_parm = TREE_CHAIN (clone_parm);
232 /* Otherwise, map the VTT parameter to `NULL'. */
235 splay_tree_insert (decl_map,
236 (splay_tree_key) parm,
237 (splay_tree_value) null_pointer_node);
240 /* Map other parameters to their equivalents in the cloned
244 splay_tree_insert (decl_map,
245 (splay_tree_key) parm,
246 (splay_tree_value) clone_parm);
247 clone_parm = TREE_CHAIN (clone_parm);
251 /* Clone the body. */
252 clone_body (clone, fn, decl_map);
254 /* There are as many statements in the clone as in the
256 DECL_ESTIMATED_INSNS (clone) = DECL_ESTIMATED_INSNS (fn);
259 splay_tree_delete (decl_map);
261 /* The clone can throw iff the original function can throw. */
262 cp_function_chain->can_throw = !TREE_NOTHROW (fn);
264 /* Now, expand this function into RTL, if appropriate. */
266 BLOCK_ABSTRACT_ORIGIN (DECL_INITIAL (clone)) = DECL_INITIAL (fn);
267 expand_or_defer_fn (clone);
268 pop_from_top_level ();
271 /* We don't need to process the original function any further. */
275 /* Dump FUNCTION_DECL FN as tree dump PHASE. */
278 dump_function (enum tree_dump_index phase, tree fn)
283 stream = dump_begin (phase, &flags);
286 fprintf (stream, "\n;; Function %s",
287 decl_as_string (fn, TFF_DECL_SPECIFIERS));
288 fprintf (stream, " (%s)\n",
289 decl_as_string (DECL_ASSEMBLER_NAME (fn), 0));
290 fprintf (stream, ";; enabled by -fdump-%s\n", dump_flag_name (phase));
291 fprintf (stream, "\n");
293 dump_node (fn, TDF_SLIM | flags, stream);
294 dump_end (phase, stream);