1 /* Utilities for ipa analysis.
2 Copyright (C) 2005, 2007, 2008 Free Software Foundation, Inc.
3 Contributed by Kenneth Zadeck <zadeck@naturalbridge.com>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
26 #include "tree-flow.h"
27 #include "tree-inline.h"
28 #include "tree-pass.h"
29 #include "langhooks.h"
30 #include "pointer-set.h"
31 #include "splay-tree.h"
33 #include "ipa-utils.h"
34 #include "ipa-reference.h"
40 #include "diagnostic.h"
41 #include "langhooks.h"
43 /* Debugging function for postorder and inorder code. NOTE is a string
44 that is printed before the nodes are printed. ORDER is an array of
45 cgraph_nodes that has COUNT useful nodes in it. */
48 ipa_print_order (FILE* out,
50 struct cgraph_node** order,
54 fprintf (out, "\n\n ordered call graph: %s\n", note);
56 for (i = count - 1; i >= 0; i--)
57 dump_cgraph_node(dump_file, order[i]);
64 struct cgraph_node **stack;
66 struct cgraph_node **result;
68 splay_tree nodes_marked_new;
70 bool allow_overwritable;
74 /* This is an implementation of Tarjan's strongly connected region
75 finder as reprinted in Aho Hopcraft and Ullman's The Design and
76 Analysis of Computer Programs (1975) pages 192-193. This version
77 has been customized for cgraph_nodes. The env parameter is because
78 it is recursive and there are no nested functions here. This
79 function should only be called from itself or
80 ipa_reduced_postorder. ENV is a stack env and would be
81 unnecessary if C had nested functions. V is the node to start
85 searchc (struct searchc_env* env, struct cgraph_node *v,
86 bool (*ignore_edge) (struct cgraph_edge *))
88 struct cgraph_edge *edge;
89 struct ipa_dfs_info *v_info = (struct ipa_dfs_info *) v->aux;
91 /* mark node as old */
92 v_info->new_node = false;
93 splay_tree_remove (env->nodes_marked_new, v->uid);
95 v_info->dfn_number = env->count;
96 v_info->low_link = env->count;
98 env->stack[(env->stack_size)++] = v;
99 v_info->on_stack = true;
101 for (edge = v->callees; edge; edge = edge->next_callee)
103 struct ipa_dfs_info * w_info;
104 enum availability avail;
105 struct cgraph_node *w = cgraph_function_or_thunk_node (edge->callee, &avail);
107 if (!w || (ignore_edge && ignore_edge (edge)))
111 && (avail > AVAIL_OVERWRITABLE
112 || (env->allow_overwritable && avail == AVAIL_OVERWRITABLE)))
114 w_info = (struct ipa_dfs_info *) w->aux;
115 if (w_info->new_node)
117 searchc (env, w, ignore_edge);
119 (v_info->low_link < w_info->low_link) ?
120 v_info->low_link : w_info->low_link;
123 if ((w_info->dfn_number < v_info->dfn_number)
124 && (w_info->on_stack))
126 (w_info->dfn_number < v_info->low_link) ?
127 w_info->dfn_number : v_info->low_link;
132 if (v_info->low_link == v_info->dfn_number)
134 struct cgraph_node *last = NULL;
135 struct cgraph_node *x;
136 struct ipa_dfs_info *x_info;
138 x = env->stack[--(env->stack_size)];
139 x_info = (struct ipa_dfs_info *) x->aux;
140 x_info->on_stack = false;
141 x_info->scc_no = v_info->dfn_number;
145 x_info->next_cycle = last;
149 env->result[env->order_pos++] = x;
153 env->result[env->order_pos++] = v;
157 /* Topsort the call graph by caller relation. Put the result in ORDER.
159 The REDUCE flag is true if you want the cycles reduced to single nodes. Set
160 ALLOW_OVERWRITABLE if nodes with such availability should be included.
161 IGNORE_EDGE, if non-NULL is a hook that may make some edges insignificant
162 for the topological sort. */
165 ipa_reduced_postorder (struct cgraph_node **order,
166 bool reduce, bool allow_overwritable,
167 bool (*ignore_edge) (struct cgraph_edge *))
169 struct cgraph_node *node;
170 struct searchc_env env;
171 splay_tree_node result;
172 env.stack = XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
176 env.nodes_marked_new = splay_tree_new (splay_tree_compare_ints, 0, 0);
179 env.allow_overwritable = allow_overwritable;
181 for (node = cgraph_nodes; node; node = node->next)
183 enum availability avail = cgraph_function_body_availability (node);
185 if (avail > AVAIL_OVERWRITABLE
186 || (allow_overwritable
187 && (avail == AVAIL_OVERWRITABLE)))
189 /* Reuse the info if it is already there. */
190 struct ipa_dfs_info *info = (struct ipa_dfs_info *) node->aux;
192 info = XCNEW (struct ipa_dfs_info);
193 info->new_node = true;
194 info->on_stack = false;
195 info->next_cycle = NULL;
198 splay_tree_insert (env.nodes_marked_new,
199 (splay_tree_key)node->uid,
200 (splay_tree_value)node);
205 result = splay_tree_min (env.nodes_marked_new);
208 node = (struct cgraph_node *)result->value;
209 searchc (&env, node, ignore_edge);
210 result = splay_tree_min (env.nodes_marked_new);
212 splay_tree_delete (env.nodes_marked_new);
215 return env.order_pos;
218 /* Deallocate all ipa_dfs_info structures pointed to by the aux pointer of call
222 ipa_free_postorder_info (void)
224 struct cgraph_node *node;
225 for (node = cgraph_nodes; node; node = node->next)
227 /* Get rid of the aux information. */
236 /* Fill array order with all nodes with output flag set in the reverse
237 topological order. Return the number of elements in the array.
238 FIXME: While walking, consider aliases, too. */
241 ipa_reverse_postorder (struct cgraph_node **order)
243 struct cgraph_node *node, *node2;
246 struct cgraph_edge *edge, last;
249 struct cgraph_node **stack =
250 XCNEWVEC (struct cgraph_node *, cgraph_n_nodes);
252 /* We have to deal with cycles nicely, so use a depth first traversal
253 output algorithm. Ignore the fact that some functions won't need
254 to be output and put them into order as well, so we get dependencies
255 right through inline functions. */
256 for (node = cgraph_nodes; node; node = node->next)
258 for (pass = 0; pass < 2; pass++)
259 for (node = cgraph_nodes; node; node = node->next)
262 || (!node->address_taken
263 && !node->global.inlined_to
264 && !cgraph_only_called_directly_or_aliased_p (node))))
270 node->aux = node->callers;
273 while (node2->aux != &last)
275 edge = (struct cgraph_edge *) node2->aux;
276 if (edge->next_caller)
277 node2->aux = edge->next_caller;
280 /* Break possible cycles involving always-inline
281 functions by ignoring edges from always-inline
282 functions to non-always-inline functions. */
283 if (DECL_DISREGARD_INLINE_LIMITS (edge->caller->decl)
284 && !DECL_DISREGARD_INLINE_LIMITS (edge->callee->decl))
286 if (!edge->caller->aux)
288 if (!edge->caller->callers)
289 edge->caller->aux = &last;
291 edge->caller->aux = edge->caller->callers;
292 stack[stack_size++] = node2;
293 node2 = edge->caller;
297 if (node2->aux == &last)
299 order[order_pos++] = node2;
301 node2 = stack[--stack_size];
308 for (node = cgraph_nodes; node; node = node->next)
315 /* Given a memory reference T, will return the variable at the bottom
316 of the access. Unlike get_base_address, this will recurse thru
320 get_base_var (tree t)
322 while (!SSA_VAR_P (t)
323 && (!CONSTANT_CLASS_P (t))
324 && TREE_CODE (t) != LABEL_DECL
325 && TREE_CODE (t) != FUNCTION_DECL
326 && TREE_CODE (t) != CONST_DECL
327 && TREE_CODE (t) != CONSTRUCTOR)
329 t = TREE_OPERAND (t, 0);
335 /* Create a new cgraph node set. */
338 cgraph_node_set_new (void)
340 cgraph_node_set new_node_set;
342 new_node_set = XCNEW (struct cgraph_node_set_def);
343 new_node_set->map = pointer_map_create ();
344 new_node_set->nodes = NULL;
349 /* Add cgraph_node NODE to cgraph_node_set SET. */
352 cgraph_node_set_add (cgraph_node_set set, struct cgraph_node *node)
356 slot = pointer_map_insert (set->map, node);
360 int index = (size_t) *slot - 1;
361 gcc_checking_assert ((VEC_index (cgraph_node_ptr, set->nodes, index)
366 *slot = (void *)(size_t) (VEC_length (cgraph_node_ptr, set->nodes) + 1);
368 /* Insert into node vector. */
369 VEC_safe_push (cgraph_node_ptr, heap, set->nodes, node);
373 /* Remove cgraph_node NODE from cgraph_node_set SET. */
376 cgraph_node_set_remove (cgraph_node_set set, struct cgraph_node *node)
378 void **slot, **last_slot;
380 struct cgraph_node *last_node;
382 slot = pointer_map_contains (set->map, node);
383 if (slot == NULL || !*slot)
386 index = (size_t) *slot - 1;
387 gcc_checking_assert (VEC_index (cgraph_node_ptr, set->nodes, index)
390 /* Remove from vector. We do this by swapping node with the last element
392 last_node = VEC_pop (cgraph_node_ptr, set->nodes);
393 if (last_node != node)
395 last_slot = pointer_map_contains (set->map, last_node);
396 gcc_checking_assert (last_slot && *last_slot);
397 *last_slot = (void *)(size_t) (index + 1);
399 /* Move the last element to the original spot of NODE. */
400 VEC_replace (cgraph_node_ptr, set->nodes, index, last_node);
403 /* Remove element from hash table. */
408 /* Find NODE in SET and return an iterator to it if found. A null iterator
409 is returned if NODE is not in SET. */
411 cgraph_node_set_iterator
412 cgraph_node_set_find (cgraph_node_set set, struct cgraph_node *node)
415 cgraph_node_set_iterator csi;
417 slot = pointer_map_contains (set->map, node);
418 if (slot == NULL || !*slot)
419 csi.index = (unsigned) ~0;
421 csi.index = (size_t)*slot - 1;
428 /* Dump content of SET to file F. */
431 dump_cgraph_node_set (FILE *f, cgraph_node_set set)
433 cgraph_node_set_iterator iter;
435 for (iter = csi_start (set); !csi_end_p (iter); csi_next (&iter))
437 struct cgraph_node *node = csi_node (iter);
438 fprintf (f, " %s/%i", cgraph_node_name (node), node->uid);
444 /* Dump content of SET to stderr. */
447 debug_cgraph_node_set (cgraph_node_set set)
449 dump_cgraph_node_set (stderr, set);
453 /* Free varpool node set. */
456 free_cgraph_node_set (cgraph_node_set set)
458 VEC_free (cgraph_node_ptr, heap, set->nodes);
459 pointer_map_destroy (set->map);
464 /* Create a new varpool node set. */
467 varpool_node_set_new (void)
469 varpool_node_set new_node_set;
471 new_node_set = XCNEW (struct varpool_node_set_def);
472 new_node_set->map = pointer_map_create ();
473 new_node_set->nodes = NULL;
478 /* Add varpool_node NODE to varpool_node_set SET. */
481 varpool_node_set_add (varpool_node_set set, struct varpool_node *node)
485 slot = pointer_map_insert (set->map, node);
489 int index = (size_t) *slot - 1;
490 gcc_checking_assert ((VEC_index (varpool_node_ptr, set->nodes, index)
495 *slot = (void *)(size_t) (VEC_length (varpool_node_ptr, set->nodes) + 1);
497 /* Insert into node vector. */
498 VEC_safe_push (varpool_node_ptr, heap, set->nodes, node);
502 /* Remove varpool_node NODE from varpool_node_set SET. */
505 varpool_node_set_remove (varpool_node_set set, struct varpool_node *node)
507 void **slot, **last_slot;
509 struct varpool_node *last_node;
511 slot = pointer_map_contains (set->map, node);
512 if (slot == NULL || !*slot)
515 index = (size_t) *slot - 1;
516 gcc_checking_assert (VEC_index (varpool_node_ptr, set->nodes, index)
519 /* Remove from vector. We do this by swapping node with the last element
521 last_node = VEC_pop (varpool_node_ptr, set->nodes);
522 if (last_node != node)
524 last_slot = pointer_map_contains (set->map, last_node);
525 gcc_checking_assert (last_slot && *last_slot);
526 *last_slot = (void *)(size_t) (index + 1);
528 /* Move the last element to the original spot of NODE. */
529 VEC_replace (varpool_node_ptr, set->nodes, index, last_node);
532 /* Remove element from hash table. */
537 /* Find NODE in SET and return an iterator to it if found. A null iterator
538 is returned if NODE is not in SET. */
540 varpool_node_set_iterator
541 varpool_node_set_find (varpool_node_set set, struct varpool_node *node)
544 varpool_node_set_iterator vsi;
546 slot = pointer_map_contains (set->map, node);
547 if (slot == NULL || !*slot)
548 vsi.index = (unsigned) ~0;
550 vsi.index = (size_t)*slot - 1;
557 /* Dump content of SET to file F. */
560 dump_varpool_node_set (FILE *f, varpool_node_set set)
562 varpool_node_set_iterator iter;
564 for (iter = vsi_start (set); !vsi_end_p (iter); vsi_next (&iter))
566 struct varpool_node *node = vsi_node (iter);
567 fprintf (f, " %s", varpool_node_name (node));
573 /* Free varpool node set. */
576 free_varpool_node_set (varpool_node_set set)
578 VEC_free (varpool_node_ptr, heap, set->nodes);
579 pointer_map_destroy (set->map);
584 /* Dump content of SET to stderr. */
587 debug_varpool_node_set (varpool_node_set set)
589 dump_varpool_node_set (stderr, set);