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f8032688 | 1 | /* Calculate (post)dominators in slightly super-linear time. |
23a5b65a | 2 | Copyright (C) 2000-2014 Free Software Foundation, Inc. |
f8032688 | 3 | Contributed by Michael Matz (matz@ifh.de). |
3a538a66 | 4 | |
1322177d | 5 | This file is part of GCC. |
3a538a66 | 6 | |
1322177d LB |
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 | |
9dcd6f09 | 9 | the Free Software Foundation; either version 3, or (at your option) |
f8032688 MM |
10 | any later version. |
11 | ||
1322177d LB |
12 | GCC is distributed in the hope that it will be useful, but WITHOUT |
13 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
14 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public | |
15 | License for more details. | |
f8032688 MM |
16 | |
17 | You should have received a copy of the GNU General Public License | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
f8032688 MM |
20 | |
21 | /* This file implements the well known algorithm from Lengauer and Tarjan | |
22 | to compute the dominators in a control flow graph. A basic block D is said | |
23 | to dominate another block X, when all paths from the entry node of the CFG | |
24 | to X go also over D. The dominance relation is a transitive reflexive | |
25 | relation and its minimal transitive reduction is a tree, called the | |
26 | dominator tree. So for each block X besides the entry block exists a | |
27 | block I(X), called the immediate dominator of X, which is the parent of X | |
28 | in the dominator tree. | |
29 | ||
a1f300c0 | 30 | The algorithm computes this dominator tree implicitly by computing for |
f8032688 | 31 | each block its immediate dominator. We use tree balancing and path |
f3b569ca | 32 | compression, so it's the O(e*a(e,v)) variant, where a(e,v) is the very |
f8032688 MM |
33 | slowly growing functional inverse of the Ackerman function. */ |
34 | ||
35 | #include "config.h" | |
36 | #include "system.h" | |
4977bab6 ZW |
37 | #include "coretypes.h" |
38 | #include "tm.h" | |
f8032688 MM |
39 | #include "rtl.h" |
40 | #include "hard-reg-set.h" | |
7932a3db | 41 | #include "obstack.h" |
f8032688 | 42 | #include "basic-block.h" |
718f9c0f | 43 | #include "diagnostic-core.h" |
355be0dc | 44 | #include "et-forest.h" |
74c96e0c | 45 | #include "timevar.h" |
1eb68d2d | 46 | #include "hash-map.h" |
66f97d31 ZD |
47 | #include "pointer-set.h" |
48 | #include "graphds.h" | |
7a8cba34 | 49 | #include "bitmap.h" |
f8032688 | 50 | |
f8032688 MM |
51 | /* We name our nodes with integers, beginning with 1. Zero is reserved for |
52 | 'undefined' or 'end of list'. The name of each node is given by the dfs | |
53 | number of the corresponding basic block. Please note, that we include the | |
54 | artificial ENTRY_BLOCK (or EXIT_BLOCK in the post-dom case) in our lists to | |
24bd1a0b | 55 | support multiple entry points. Its dfs number is of course 1. */ |
f8032688 MM |
56 | |
57 | /* Type of Basic Block aka. TBB */ | |
58 | typedef unsigned int TBB; | |
59 | ||
60 | /* We work in a poor-mans object oriented fashion, and carry an instance of | |
61 | this structure through all our 'methods'. It holds various arrays | |
62 | reflecting the (sub)structure of the flowgraph. Most of them are of type | |
63 | TBB and are also indexed by TBB. */ | |
64 | ||
65 | struct dom_info | |
66 | { | |
67 | /* The parent of a node in the DFS tree. */ | |
68 | TBB *dfs_parent; | |
69 | /* For a node x key[x] is roughly the node nearest to the root from which | |
70 | exists a way to x only over nodes behind x. Such a node is also called | |
71 | semidominator. */ | |
72 | TBB *key; | |
73 | /* The value in path_min[x] is the node y on the path from x to the root of | |
74 | the tree x is in with the smallest key[y]. */ | |
75 | TBB *path_min; | |
76 | /* bucket[x] points to the first node of the set of nodes having x as key. */ | |
77 | TBB *bucket; | |
78 | /* And next_bucket[x] points to the next node. */ | |
79 | TBB *next_bucket; | |
80 | /* After the algorithm is done, dom[x] contains the immediate dominator | |
81 | of x. */ | |
82 | TBB *dom; | |
83 | ||
84 | /* The following few fields implement the structures needed for disjoint | |
85 | sets. */ | |
fa10beec | 86 | /* set_chain[x] is the next node on the path from x to the representative |
f8032688 MM |
87 | of the set containing x. If set_chain[x]==0 then x is a root. */ |
88 | TBB *set_chain; | |
89 | /* set_size[x] is the number of elements in the set named by x. */ | |
90 | unsigned int *set_size; | |
91 | /* set_child[x] is used for balancing the tree representing a set. It can | |
92 | be understood as the next sibling of x. */ | |
93 | TBB *set_child; | |
94 | ||
95 | /* If b is the number of a basic block (BB->index), dfs_order[b] is the | |
96 | number of that node in DFS order counted from 1. This is an index | |
97 | into most of the other arrays in this structure. */ | |
98 | TBB *dfs_order; | |
09da1532 | 99 | /* If x is the DFS-index of a node which corresponds with a basic block, |
f8032688 MM |
100 | dfs_to_bb[x] is that basic block. Note, that in our structure there are |
101 | more nodes that basic blocks, so only dfs_to_bb[dfs_order[bb->index]]==bb | |
102 | is true for every basic block bb, but not the opposite. */ | |
103 | basic_block *dfs_to_bb; | |
104 | ||
26e0e410 | 105 | /* This is the next free DFS number when creating the DFS tree. */ |
f8032688 MM |
106 | unsigned int dfsnum; |
107 | /* The number of nodes in the DFS tree (==dfsnum-1). */ | |
108 | unsigned int nodes; | |
26e0e410 RH |
109 | |
110 | /* Blocks with bits set here have a fake edge to EXIT. These are used | |
111 | to turn a DFS forest into a proper tree. */ | |
112 | bitmap fake_exit_edge; | |
f8032688 MM |
113 | }; |
114 | ||
26e0e410 | 115 | static void init_dom_info (struct dom_info *, enum cdi_direction); |
7080f735 | 116 | static void free_dom_info (struct dom_info *); |
2b28c07a JC |
117 | static void calc_dfs_tree_nonrec (struct dom_info *, basic_block, bool); |
118 | static void calc_dfs_tree (struct dom_info *, bool); | |
7080f735 AJ |
119 | static void compress (struct dom_info *, TBB); |
120 | static TBB eval (struct dom_info *, TBB); | |
121 | static void link_roots (struct dom_info *, TBB, TBB); | |
2b28c07a | 122 | static void calc_idoms (struct dom_info *, bool); |
d47cc544 | 123 | void debug_dominance_info (enum cdi_direction); |
1fc3998d | 124 | void debug_dominance_tree (enum cdi_direction, basic_block); |
f8032688 MM |
125 | |
126 | /* Helper macro for allocating and initializing an array, | |
127 | for aesthetic reasons. */ | |
128 | #define init_ar(var, type, num, content) \ | |
3a538a66 KH |
129 | do \ |
130 | { \ | |
131 | unsigned int i = 1; /* Catch content == i. */ \ | |
132 | if (! (content)) \ | |
5ed6ace5 | 133 | (var) = XCNEWVEC (type, num); \ |
3a538a66 KH |
134 | else \ |
135 | { \ | |
5ed6ace5 | 136 | (var) = XNEWVEC (type, (num)); \ |
3a538a66 KH |
137 | for (i = 0; i < num; i++) \ |
138 | (var)[i] = (content); \ | |
139 | } \ | |
140 | } \ | |
141 | while (0) | |
f8032688 MM |
142 | |
143 | /* Allocate all needed memory in a pessimistic fashion (so we round up). | |
4912a07c | 144 | This initializes the contents of DI, which already must be allocated. */ |
f8032688 MM |
145 | |
146 | static void | |
26e0e410 | 147 | init_dom_info (struct dom_info *di, enum cdi_direction dir) |
f8032688 | 148 | { |
6fb5fa3c | 149 | /* We need memory for n_basic_blocks nodes. */ |
0cae8d31 | 150 | unsigned int num = n_basic_blocks_for_fn (cfun); |
f8032688 MM |
151 | init_ar (di->dfs_parent, TBB, num, 0); |
152 | init_ar (di->path_min, TBB, num, i); | |
153 | init_ar (di->key, TBB, num, i); | |
154 | init_ar (di->dom, TBB, num, 0); | |
155 | ||
156 | init_ar (di->bucket, TBB, num, 0); | |
157 | init_ar (di->next_bucket, TBB, num, 0); | |
158 | ||
159 | init_ar (di->set_chain, TBB, num, 0); | |
160 | init_ar (di->set_size, unsigned int, num, 1); | |
161 | init_ar (di->set_child, TBB, num, 0); | |
162 | ||
8b1c6fd7 DM |
163 | init_ar (di->dfs_order, TBB, |
164 | (unsigned int) last_basic_block_for_fn (cfun) + 1, 0); | |
f8032688 MM |
165 | init_ar (di->dfs_to_bb, basic_block, num, 0); |
166 | ||
167 | di->dfsnum = 1; | |
168 | di->nodes = 0; | |
26e0e410 | 169 | |
2b28c07a JC |
170 | switch (dir) |
171 | { | |
172 | case CDI_DOMINATORS: | |
173 | di->fake_exit_edge = NULL; | |
174 | break; | |
175 | case CDI_POST_DOMINATORS: | |
176 | di->fake_exit_edge = BITMAP_ALLOC (NULL); | |
177 | break; | |
178 | default: | |
179 | gcc_unreachable (); | |
180 | break; | |
181 | } | |
f8032688 MM |
182 | } |
183 | ||
184 | #undef init_ar | |
185 | ||
2b28c07a JC |
186 | /* Map dominance calculation type to array index used for various |
187 | dominance information arrays. This version is simple -- it will need | |
188 | to be modified, obviously, if additional values are added to | |
189 | cdi_direction. */ | |
190 | ||
191 | static unsigned int | |
192 | dom_convert_dir_to_idx (enum cdi_direction dir) | |
193 | { | |
2ba31c05 | 194 | gcc_checking_assert (dir == CDI_DOMINATORS || dir == CDI_POST_DOMINATORS); |
2b28c07a JC |
195 | return dir - 1; |
196 | } | |
197 | ||
f8032688 MM |
198 | /* Free all allocated memory in DI, but not DI itself. */ |
199 | ||
200 | static void | |
7080f735 | 201 | free_dom_info (struct dom_info *di) |
f8032688 MM |
202 | { |
203 | free (di->dfs_parent); | |
204 | free (di->path_min); | |
205 | free (di->key); | |
206 | free (di->dom); | |
207 | free (di->bucket); | |
208 | free (di->next_bucket); | |
209 | free (di->set_chain); | |
210 | free (di->set_size); | |
211 | free (di->set_child); | |
212 | free (di->dfs_order); | |
213 | free (di->dfs_to_bb); | |
8bdbfff5 | 214 | BITMAP_FREE (di->fake_exit_edge); |
f8032688 MM |
215 | } |
216 | ||
217 | /* The nonrecursive variant of creating a DFS tree. DI is our working | |
218 | structure, BB the starting basic block for this tree and REVERSE | |
219 | is true, if predecessors should be visited instead of successors of a | |
220 | node. After this is done all nodes reachable from BB were visited, have | |
221 | assigned their dfs number and are linked together to form a tree. */ | |
222 | ||
223 | static void | |
2b28c07a | 224 | calc_dfs_tree_nonrec (struct dom_info *di, basic_block bb, bool reverse) |
f8032688 | 225 | { |
f8032688 MM |
226 | /* We call this _only_ if bb is not already visited. */ |
227 | edge e; | |
228 | TBB child_i, my_i = 0; | |
628f6a4e BE |
229 | edge_iterator *stack; |
230 | edge_iterator ei, einext; | |
f8032688 | 231 | int sp; |
6626665f | 232 | /* Start block (the entry block for forward problem, exit block for backward |
f8032688 MM |
233 | problem). */ |
234 | basic_block en_block; | |
235 | /* Ending block. */ | |
236 | basic_block ex_block; | |
237 | ||
0cae8d31 | 238 | stack = XNEWVEC (edge_iterator, n_basic_blocks_for_fn (cfun) + 1); |
f8032688 MM |
239 | sp = 0; |
240 | ||
241 | /* Initialize our border blocks, and the first edge. */ | |
242 | if (reverse) | |
243 | { | |
628f6a4e | 244 | ei = ei_start (bb->preds); |
fefa31b5 DM |
245 | en_block = EXIT_BLOCK_PTR_FOR_FN (cfun); |
246 | ex_block = ENTRY_BLOCK_PTR_FOR_FN (cfun); | |
f8032688 MM |
247 | } |
248 | else | |
249 | { | |
628f6a4e | 250 | ei = ei_start (bb->succs); |
fefa31b5 DM |
251 | en_block = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
252 | ex_block = EXIT_BLOCK_PTR_FOR_FN (cfun); | |
f8032688 MM |
253 | } |
254 | ||
255 | /* When the stack is empty we break out of this loop. */ | |
256 | while (1) | |
257 | { | |
258 | basic_block bn; | |
259 | ||
260 | /* This loop traverses edges e in depth first manner, and fills the | |
261 | stack. */ | |
628f6a4e | 262 | while (!ei_end_p (ei)) |
f8032688 | 263 | { |
628f6a4e | 264 | e = ei_edge (ei); |
f8032688 MM |
265 | |
266 | /* Deduce from E the current and the next block (BB and BN), and the | |
267 | next edge. */ | |
268 | if (reverse) | |
269 | { | |
270 | bn = e->src; | |
271 | ||
272 | /* If the next node BN is either already visited or a border | |
273 | block the current edge is useless, and simply overwritten | |
274 | with the next edge out of the current node. */ | |
0b17ab2f | 275 | if (bn == ex_block || di->dfs_order[bn->index]) |
f8032688 | 276 | { |
628f6a4e | 277 | ei_next (&ei); |
f8032688 MM |
278 | continue; |
279 | } | |
280 | bb = e->dest; | |
628f6a4e | 281 | einext = ei_start (bn->preds); |
f8032688 MM |
282 | } |
283 | else | |
284 | { | |
285 | bn = e->dest; | |
0b17ab2f | 286 | if (bn == ex_block || di->dfs_order[bn->index]) |
f8032688 | 287 | { |
628f6a4e | 288 | ei_next (&ei); |
f8032688 MM |
289 | continue; |
290 | } | |
291 | bb = e->src; | |
628f6a4e | 292 | einext = ei_start (bn->succs); |
f8032688 MM |
293 | } |
294 | ||
ced3f397 | 295 | gcc_assert (bn != en_block); |
f8032688 MM |
296 | |
297 | /* Fill the DFS tree info calculatable _before_ recursing. */ | |
298 | if (bb != en_block) | |
0b17ab2f | 299 | my_i = di->dfs_order[bb->index]; |
f8032688 | 300 | else |
8b1c6fd7 | 301 | my_i = di->dfs_order[last_basic_block_for_fn (cfun)]; |
0b17ab2f | 302 | child_i = di->dfs_order[bn->index] = di->dfsnum++; |
f8032688 MM |
303 | di->dfs_to_bb[child_i] = bn; |
304 | di->dfs_parent[child_i] = my_i; | |
305 | ||
306 | /* Save the current point in the CFG on the stack, and recurse. */ | |
628f6a4e BE |
307 | stack[sp++] = ei; |
308 | ei = einext; | |
f8032688 MM |
309 | } |
310 | ||
311 | if (!sp) | |
312 | break; | |
628f6a4e | 313 | ei = stack[--sp]; |
f8032688 MM |
314 | |
315 | /* OK. The edge-list was exhausted, meaning normally we would | |
316 | end the recursion. After returning from the recursive call, | |
317 | there were (may be) other statements which were run after a | |
318 | child node was completely considered by DFS. Here is the | |
319 | point to do it in the non-recursive variant. | |
320 | E.g. The block just completed is in e->dest for forward DFS, | |
321 | the block not yet completed (the parent of the one above) | |
322 | in e->src. This could be used e.g. for computing the number of | |
323 | descendants or the tree depth. */ | |
628f6a4e | 324 | ei_next (&ei); |
f8032688 MM |
325 | } |
326 | free (stack); | |
327 | } | |
328 | ||
329 | /* The main entry for calculating the DFS tree or forest. DI is our working | |
330 | structure and REVERSE is true, if we are interested in the reverse flow | |
331 | graph. In that case the result is not necessarily a tree but a forest, | |
332 | because there may be nodes from which the EXIT_BLOCK is unreachable. */ | |
333 | ||
334 | static void | |
2b28c07a | 335 | calc_dfs_tree (struct dom_info *di, bool reverse) |
f8032688 MM |
336 | { |
337 | /* The first block is the ENTRY_BLOCK (or EXIT_BLOCK if REVERSE). */ | |
fefa31b5 DM |
338 | basic_block begin = (reverse |
339 | ? EXIT_BLOCK_PTR_FOR_FN (cfun) : ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
8b1c6fd7 | 340 | di->dfs_order[last_basic_block_for_fn (cfun)] = di->dfsnum; |
f8032688 MM |
341 | di->dfs_to_bb[di->dfsnum] = begin; |
342 | di->dfsnum++; | |
343 | ||
344 | calc_dfs_tree_nonrec (di, begin, reverse); | |
345 | ||
346 | if (reverse) | |
347 | { | |
348 | /* In the post-dom case we may have nodes without a path to EXIT_BLOCK. | |
349 | They are reverse-unreachable. In the dom-case we disallow such | |
26e0e410 RH |
350 | nodes, but in post-dom we have to deal with them. |
351 | ||
352 | There are two situations in which this occurs. First, noreturn | |
353 | functions. Second, infinite loops. In the first case we need to | |
354 | pretend that there is an edge to the exit block. In the second | |
355 | case, we wind up with a forest. We need to process all noreturn | |
356 | blocks before we know if we've got any infinite loops. */ | |
357 | ||
e0082a72 | 358 | basic_block b; |
26e0e410 RH |
359 | bool saw_unconnected = false; |
360 | ||
4f42035e | 361 | FOR_EACH_BB_REVERSE_FN (b, cfun) |
f8032688 | 362 | { |
628f6a4e | 363 | if (EDGE_COUNT (b->succs) > 0) |
26e0e410 RH |
364 | { |
365 | if (di->dfs_order[b->index] == 0) | |
366 | saw_unconnected = true; | |
367 | continue; | |
368 | } | |
369 | bitmap_set_bit (di->fake_exit_edge, b->index); | |
0b17ab2f | 370 | di->dfs_order[b->index] = di->dfsnum; |
f8032688 | 371 | di->dfs_to_bb[di->dfsnum] = b; |
8b1c6fd7 DM |
372 | di->dfs_parent[di->dfsnum] = |
373 | di->dfs_order[last_basic_block_for_fn (cfun)]; | |
f8032688 MM |
374 | di->dfsnum++; |
375 | calc_dfs_tree_nonrec (di, b, reverse); | |
376 | } | |
26e0e410 RH |
377 | |
378 | if (saw_unconnected) | |
379 | { | |
4f42035e | 380 | FOR_EACH_BB_REVERSE_FN (b, cfun) |
26e0e410 | 381 | { |
03b06a83 | 382 | basic_block b2; |
26e0e410 RH |
383 | if (di->dfs_order[b->index]) |
384 | continue; | |
03b06a83 SB |
385 | b2 = dfs_find_deadend (b); |
386 | gcc_checking_assert (di->dfs_order[b2->index] == 0); | |
387 | bitmap_set_bit (di->fake_exit_edge, b2->index); | |
388 | di->dfs_order[b2->index] = di->dfsnum; | |
389 | di->dfs_to_bb[di->dfsnum] = b2; | |
8b1c6fd7 DM |
390 | di->dfs_parent[di->dfsnum] = |
391 | di->dfs_order[last_basic_block_for_fn (cfun)]; | |
26e0e410 | 392 | di->dfsnum++; |
03b06a83 SB |
393 | calc_dfs_tree_nonrec (di, b2, reverse); |
394 | gcc_checking_assert (di->dfs_order[b->index]); | |
26e0e410 RH |
395 | } |
396 | } | |
f8032688 MM |
397 | } |
398 | ||
399 | di->nodes = di->dfsnum - 1; | |
400 | ||
24bd1a0b | 401 | /* This aborts e.g. when there is _no_ path from ENTRY to EXIT at all. */ |
0cae8d31 | 402 | gcc_assert (di->nodes == (unsigned int) n_basic_blocks_for_fn (cfun) - 1); |
f8032688 MM |
403 | } |
404 | ||
405 | /* Compress the path from V to the root of its set and update path_min at the | |
406 | same time. After compress(di, V) set_chain[V] is the root of the set V is | |
407 | in and path_min[V] is the node with the smallest key[] value on the path | |
408 | from V to that root. */ | |
409 | ||
410 | static void | |
7080f735 | 411 | compress (struct dom_info *di, TBB v) |
f8032688 MM |
412 | { |
413 | /* Btw. It's not worth to unrecurse compress() as the depth is usually not | |
414 | greater than 5 even for huge graphs (I've not seen call depth > 4). | |
415 | Also performance wise compress() ranges _far_ behind eval(). */ | |
416 | TBB parent = di->set_chain[v]; | |
417 | if (di->set_chain[parent]) | |
418 | { | |
419 | compress (di, parent); | |
420 | if (di->key[di->path_min[parent]] < di->key[di->path_min[v]]) | |
421 | di->path_min[v] = di->path_min[parent]; | |
422 | di->set_chain[v] = di->set_chain[parent]; | |
423 | } | |
424 | } | |
425 | ||
426 | /* Compress the path from V to the set root of V if needed (when the root has | |
427 | changed since the last call). Returns the node with the smallest key[] | |
428 | value on the path from V to the root. */ | |
429 | ||
430 | static inline TBB | |
7080f735 | 431 | eval (struct dom_info *di, TBB v) |
f8032688 | 432 | { |
fa10beec | 433 | /* The representative of the set V is in, also called root (as the set |
f8032688 MM |
434 | representation is a tree). */ |
435 | TBB rep = di->set_chain[v]; | |
436 | ||
437 | /* V itself is the root. */ | |
438 | if (!rep) | |
439 | return di->path_min[v]; | |
440 | ||
441 | /* Compress only if necessary. */ | |
442 | if (di->set_chain[rep]) | |
443 | { | |
444 | compress (di, v); | |
445 | rep = di->set_chain[v]; | |
446 | } | |
447 | ||
448 | if (di->key[di->path_min[rep]] >= di->key[di->path_min[v]]) | |
449 | return di->path_min[v]; | |
450 | else | |
451 | return di->path_min[rep]; | |
452 | } | |
453 | ||
454 | /* This essentially merges the two sets of V and W, giving a single set with | |
455 | the new root V. The internal representation of these disjoint sets is a | |
456 | balanced tree. Currently link(V,W) is only used with V being the parent | |
457 | of W. */ | |
458 | ||
459 | static void | |
7080f735 | 460 | link_roots (struct dom_info *di, TBB v, TBB w) |
f8032688 MM |
461 | { |
462 | TBB s = w; | |
463 | ||
464 | /* Rebalance the tree. */ | |
465 | while (di->key[di->path_min[w]] < di->key[di->path_min[di->set_child[s]]]) | |
466 | { | |
467 | if (di->set_size[s] + di->set_size[di->set_child[di->set_child[s]]] | |
468 | >= 2 * di->set_size[di->set_child[s]]) | |
469 | { | |
470 | di->set_chain[di->set_child[s]] = s; | |
471 | di->set_child[s] = di->set_child[di->set_child[s]]; | |
472 | } | |
473 | else | |
474 | { | |
475 | di->set_size[di->set_child[s]] = di->set_size[s]; | |
476 | s = di->set_chain[s] = di->set_child[s]; | |
477 | } | |
478 | } | |
479 | ||
480 | di->path_min[s] = di->path_min[w]; | |
481 | di->set_size[v] += di->set_size[w]; | |
482 | if (di->set_size[v] < 2 * di->set_size[w]) | |
483 | { | |
484 | TBB tmp = s; | |
485 | s = di->set_child[v]; | |
486 | di->set_child[v] = tmp; | |
487 | } | |
488 | ||
489 | /* Merge all subtrees. */ | |
490 | while (s) | |
491 | { | |
492 | di->set_chain[s] = v; | |
493 | s = di->set_child[s]; | |
494 | } | |
495 | } | |
496 | ||
497 | /* This calculates the immediate dominators (or post-dominators if REVERSE is | |
498 | true). DI is our working structure and should hold the DFS forest. | |
499 | On return the immediate dominator to node V is in di->dom[V]. */ | |
500 | ||
501 | static void | |
2b28c07a | 502 | calc_idoms (struct dom_info *di, bool reverse) |
f8032688 MM |
503 | { |
504 | TBB v, w, k, par; | |
505 | basic_block en_block; | |
628f6a4e BE |
506 | edge_iterator ei, einext; |
507 | ||
f8032688 | 508 | if (reverse) |
fefa31b5 | 509 | en_block = EXIT_BLOCK_PTR_FOR_FN (cfun); |
f8032688 | 510 | else |
fefa31b5 | 511 | en_block = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
f8032688 MM |
512 | |
513 | /* Go backwards in DFS order, to first look at the leafs. */ | |
514 | v = di->nodes; | |
515 | while (v > 1) | |
516 | { | |
517 | basic_block bb = di->dfs_to_bb[v]; | |
628f6a4e | 518 | edge e; |
f8032688 MM |
519 | |
520 | par = di->dfs_parent[v]; | |
521 | k = v; | |
628f6a4e BE |
522 | |
523 | ei = (reverse) ? ei_start (bb->succs) : ei_start (bb->preds); | |
524 | ||
f8032688 | 525 | if (reverse) |
26e0e410 | 526 | { |
26e0e410 RH |
527 | /* If this block has a fake edge to exit, process that first. */ |
528 | if (bitmap_bit_p (di->fake_exit_edge, bb->index)) | |
529 | { | |
628f6a4e BE |
530 | einext = ei; |
531 | einext.index = 0; | |
26e0e410 RH |
532 | goto do_fake_exit_edge; |
533 | } | |
534 | } | |
f8032688 MM |
535 | |
536 | /* Search all direct predecessors for the smallest node with a path | |
537 | to them. That way we have the smallest node with also a path to | |
538 | us only over nodes behind us. In effect we search for our | |
539 | semidominator. */ | |
628f6a4e | 540 | while (!ei_end_p (ei)) |
f8032688 MM |
541 | { |
542 | TBB k1; | |
543 | basic_block b; | |
544 | ||
628f6a4e BE |
545 | e = ei_edge (ei); |
546 | b = (reverse) ? e->dest : e->src; | |
547 | einext = ei; | |
548 | ei_next (&einext); | |
549 | ||
f8032688 | 550 | if (b == en_block) |
26e0e410 RH |
551 | { |
552 | do_fake_exit_edge: | |
8b1c6fd7 | 553 | k1 = di->dfs_order[last_basic_block_for_fn (cfun)]; |
26e0e410 | 554 | } |
f8032688 | 555 | else |
0b17ab2f | 556 | k1 = di->dfs_order[b->index]; |
f8032688 MM |
557 | |
558 | /* Call eval() only if really needed. If k1 is above V in DFS tree, | |
559 | then we know, that eval(k1) == k1 and key[k1] == k1. */ | |
560 | if (k1 > v) | |
561 | k1 = di->key[eval (di, k1)]; | |
562 | if (k1 < k) | |
563 | k = k1; | |
628f6a4e BE |
564 | |
565 | ei = einext; | |
f8032688 MM |
566 | } |
567 | ||
568 | di->key[v] = k; | |
569 | link_roots (di, par, v); | |
570 | di->next_bucket[v] = di->bucket[k]; | |
571 | di->bucket[k] = v; | |
572 | ||
573 | /* Transform semidominators into dominators. */ | |
574 | for (w = di->bucket[par]; w; w = di->next_bucket[w]) | |
575 | { | |
576 | k = eval (di, w); | |
577 | if (di->key[k] < di->key[w]) | |
578 | di->dom[w] = k; | |
579 | else | |
580 | di->dom[w] = par; | |
581 | } | |
582 | /* We don't need to cleanup next_bucket[]. */ | |
583 | di->bucket[par] = 0; | |
584 | v--; | |
585 | } | |
586 | ||
a1f300c0 | 587 | /* Explicitly define the dominators. */ |
f8032688 MM |
588 | di->dom[1] = 0; |
589 | for (v = 2; v <= di->nodes; v++) | |
590 | if (di->dom[v] != di->key[v]) | |
591 | di->dom[v] = di->dom[di->dom[v]]; | |
592 | } | |
593 | ||
d47cc544 SB |
594 | /* Assign dfs numbers starting from NUM to NODE and its sons. */ |
595 | ||
596 | static void | |
597 | assign_dfs_numbers (struct et_node *node, int *num) | |
598 | { | |
599 | struct et_node *son; | |
600 | ||
601 | node->dfs_num_in = (*num)++; | |
602 | ||
603 | if (node->son) | |
604 | { | |
605 | assign_dfs_numbers (node->son, num); | |
606 | for (son = node->son->right; son != node->son; son = son->right) | |
6de9cd9a | 607 | assign_dfs_numbers (son, num); |
d47cc544 | 608 | } |
f8032688 | 609 | |
d47cc544 SB |
610 | node->dfs_num_out = (*num)++; |
611 | } | |
f8032688 | 612 | |
5d3cc252 | 613 | /* Compute the data necessary for fast resolving of dominator queries in a |
d47cc544 | 614 | static dominator tree. */ |
f8032688 | 615 | |
d47cc544 SB |
616 | static void |
617 | compute_dom_fast_query (enum cdi_direction dir) | |
618 | { | |
619 | int num = 0; | |
620 | basic_block bb; | |
2b28c07a | 621 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
d47cc544 | 622 | |
2ba31c05 | 623 | gcc_checking_assert (dom_info_available_p (dir)); |
d47cc544 | 624 | |
2b28c07a | 625 | if (dom_computed[dir_index] == DOM_OK) |
d47cc544 SB |
626 | return; |
627 | ||
04a90bec | 628 | FOR_ALL_BB_FN (bb, cfun) |
d47cc544 | 629 | { |
2b28c07a JC |
630 | if (!bb->dom[dir_index]->father) |
631 | assign_dfs_numbers (bb->dom[dir_index], &num); | |
d47cc544 SB |
632 | } |
633 | ||
2b28c07a | 634 | dom_computed[dir_index] = DOM_OK; |
d47cc544 SB |
635 | } |
636 | ||
637 | /* The main entry point into this module. DIR is set depending on whether | |
638 | we want to compute dominators or postdominators. */ | |
639 | ||
640 | void | |
641 | calculate_dominance_info (enum cdi_direction dir) | |
f8032688 MM |
642 | { |
643 | struct dom_info di; | |
355be0dc | 644 | basic_block b; |
2b28c07a JC |
645 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
646 | bool reverse = (dir == CDI_POST_DOMINATORS) ? true : false; | |
355be0dc | 647 | |
2b28c07a | 648 | if (dom_computed[dir_index] == DOM_OK) |
d47cc544 | 649 | return; |
355be0dc | 650 | |
74c96e0c | 651 | timevar_push (TV_DOMINANCE); |
fce22de5 | 652 | if (!dom_info_available_p (dir)) |
d47cc544 | 653 | { |
2b28c07a | 654 | gcc_assert (!n_bbs_in_dom_tree[dir_index]); |
f8032688 | 655 | |
04a90bec | 656 | FOR_ALL_BB_FN (b, cfun) |
d47cc544 | 657 | { |
2b28c07a | 658 | b->dom[dir_index] = et_new_tree (b); |
d47cc544 | 659 | } |
0cae8d31 | 660 | n_bbs_in_dom_tree[dir_index] = n_basic_blocks_for_fn (cfun); |
f8032688 | 661 | |
26e0e410 | 662 | init_dom_info (&di, dir); |
2b28c07a JC |
663 | calc_dfs_tree (&di, reverse); |
664 | calc_idoms (&di, reverse); | |
355be0dc | 665 | |
11cd3bed | 666 | FOR_EACH_BB_FN (b, cfun) |
d47cc544 SB |
667 | { |
668 | TBB d = di.dom[di.dfs_order[b->index]]; | |
669 | ||
670 | if (di.dfs_to_bb[d]) | |
2b28c07a | 671 | et_set_father (b->dom[dir_index], di.dfs_to_bb[d]->dom[dir_index]); |
d47cc544 | 672 | } |
e0082a72 | 673 | |
d47cc544 | 674 | free_dom_info (&di); |
2b28c07a | 675 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; |
355be0dc JH |
676 | } |
677 | ||
d47cc544 | 678 | compute_dom_fast_query (dir); |
74c96e0c ZD |
679 | |
680 | timevar_pop (TV_DOMINANCE); | |
355be0dc JH |
681 | } |
682 | ||
d47cc544 | 683 | /* Free dominance information for direction DIR. */ |
355be0dc | 684 | void |
e3f613cb | 685 | free_dominance_info (function *fn, enum cdi_direction dir) |
355be0dc JH |
686 | { |
687 | basic_block bb; | |
2b28c07a | 688 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
355be0dc | 689 | |
e3f613cb | 690 | if (!dom_info_available_p (fn, dir)) |
d47cc544 SB |
691 | return; |
692 | ||
e3f613cb | 693 | FOR_ALL_BB_FN (bb, fn) |
d47cc544 | 694 | { |
2b28c07a JC |
695 | et_free_tree_force (bb->dom[dir_index]); |
696 | bb->dom[dir_index] = NULL; | |
d47cc544 | 697 | } |
5a6ccafd | 698 | et_free_pools (); |
d47cc544 | 699 | |
e3f613cb RB |
700 | fn->cfg->x_n_bbs_in_dom_tree[dir_index] = 0; |
701 | ||
702 | fn->cfg->x_dom_computed[dir_index] = DOM_NONE; | |
703 | } | |
6de9cd9a | 704 | |
e3f613cb RB |
705 | void |
706 | free_dominance_info (enum cdi_direction dir) | |
707 | { | |
708 | free_dominance_info (cfun, dir); | |
355be0dc JH |
709 | } |
710 | ||
711 | /* Return the immediate dominator of basic block BB. */ | |
712 | basic_block | |
d47cc544 | 713 | get_immediate_dominator (enum cdi_direction dir, basic_block bb) |
355be0dc | 714 | { |
2b28c07a JC |
715 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
716 | struct et_node *node = bb->dom[dir_index]; | |
d47cc544 | 717 | |
2ba31c05 | 718 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 SB |
719 | |
720 | if (!node->father) | |
721 | return NULL; | |
722 | ||
f883e0a7 | 723 | return (basic_block) node->father->data; |
355be0dc JH |
724 | } |
725 | ||
726 | /* Set the immediate dominator of the block possibly removing | |
727 | existing edge. NULL can be used to remove any edge. */ | |
7031a8b9 | 728 | void |
d47cc544 SB |
729 | set_immediate_dominator (enum cdi_direction dir, basic_block bb, |
730 | basic_block dominated_by) | |
355be0dc | 731 | { |
2b28c07a JC |
732 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
733 | struct et_node *node = bb->dom[dir_index]; | |
b8698a0f | 734 | |
2ba31c05 | 735 | gcc_checking_assert (dom_computed[dir_index]); |
355be0dc | 736 | |
d47cc544 | 737 | if (node->father) |
355be0dc | 738 | { |
d47cc544 | 739 | if (node->father->data == dominated_by) |
6de9cd9a | 740 | return; |
d47cc544 | 741 | et_split (node); |
355be0dc | 742 | } |
d47cc544 SB |
743 | |
744 | if (dominated_by) | |
2b28c07a | 745 | et_set_father (node, dominated_by->dom[dir_index]); |
d47cc544 | 746 | |
2b28c07a JC |
747 | if (dom_computed[dir_index] == DOM_OK) |
748 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
355be0dc JH |
749 | } |
750 | ||
66f97d31 ZD |
751 | /* Returns the list of basic blocks immediately dominated by BB, in the |
752 | direction DIR. */ | |
9771b263 | 753 | vec<basic_block> |
66f97d31 | 754 | get_dominated_by (enum cdi_direction dir, basic_block bb) |
355be0dc | 755 | { |
66f97d31 | 756 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
2b28c07a | 757 | struct et_node *node = bb->dom[dir_index], *son = node->son, *ason; |
6e1aa848 | 758 | vec<basic_block> bbs = vNULL; |
66f97d31 | 759 | |
2ba31c05 | 760 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 SB |
761 | |
762 | if (!son) | |
6e1aa848 | 763 | return vNULL; |
d47cc544 | 764 | |
9771b263 | 765 | bbs.safe_push ((basic_block) son->data); |
2d888286 | 766 | for (ason = son->right; ason != son; ason = ason->right) |
9771b263 | 767 | bbs.safe_push ((basic_block) ason->data); |
355be0dc | 768 | |
66f97d31 | 769 | return bbs; |
355be0dc JH |
770 | } |
771 | ||
66f97d31 ZD |
772 | /* Returns the list of basic blocks that are immediately dominated (in |
773 | direction DIR) by some block between N_REGION ones stored in REGION, | |
774 | except for blocks in the REGION itself. */ | |
b8698a0f | 775 | |
9771b263 | 776 | vec<basic_block> |
42759f1e | 777 | get_dominated_by_region (enum cdi_direction dir, basic_block *region, |
66f97d31 | 778 | unsigned n_region) |
42759f1e | 779 | { |
66f97d31 | 780 | unsigned i; |
42759f1e | 781 | basic_block dom; |
6e1aa848 | 782 | vec<basic_block> doms = vNULL; |
42759f1e ZD |
783 | |
784 | for (i = 0; i < n_region; i++) | |
6580ee77 | 785 | region[i]->flags |= BB_DUPLICATED; |
42759f1e ZD |
786 | for (i = 0; i < n_region; i++) |
787 | for (dom = first_dom_son (dir, region[i]); | |
788 | dom; | |
789 | dom = next_dom_son (dir, dom)) | |
6580ee77 | 790 | if (!(dom->flags & BB_DUPLICATED)) |
9771b263 | 791 | doms.safe_push (dom); |
42759f1e | 792 | for (i = 0; i < n_region; i++) |
6580ee77 | 793 | region[i]->flags &= ~BB_DUPLICATED; |
42759f1e | 794 | |
66f97d31 | 795 | return doms; |
42759f1e ZD |
796 | } |
797 | ||
438c239d | 798 | /* Returns the list of basic blocks including BB dominated by BB, in the |
cad9aa15 MK |
799 | direction DIR up to DEPTH in the dominator tree. The DEPTH of zero will |
800 | produce a vector containing all dominated blocks. The vector will be sorted | |
801 | in preorder. */ | |
438c239d | 802 | |
9771b263 | 803 | vec<basic_block> |
cad9aa15 | 804 | get_dominated_to_depth (enum cdi_direction dir, basic_block bb, int depth) |
438c239d | 805 | { |
6e1aa848 | 806 | vec<basic_block> bbs = vNULL; |
438c239d | 807 | unsigned i; |
cad9aa15 | 808 | unsigned next_level_start; |
438c239d RG |
809 | |
810 | i = 0; | |
9771b263 DN |
811 | bbs.safe_push (bb); |
812 | next_level_start = 1; /* = bbs.length (); */ | |
438c239d RG |
813 | |
814 | do | |
815 | { | |
816 | basic_block son; | |
817 | ||
9771b263 | 818 | bb = bbs[i++]; |
438c239d RG |
819 | for (son = first_dom_son (dir, bb); |
820 | son; | |
821 | son = next_dom_son (dir, son)) | |
9771b263 | 822 | bbs.safe_push (son); |
cad9aa15 MK |
823 | |
824 | if (i == next_level_start && --depth) | |
9771b263 | 825 | next_level_start = bbs.length (); |
438c239d | 826 | } |
cad9aa15 | 827 | while (i < next_level_start); |
438c239d RG |
828 | |
829 | return bbs; | |
830 | } | |
831 | ||
cad9aa15 MK |
832 | /* Returns the list of basic blocks including BB dominated by BB, in the |
833 | direction DIR. The vector will be sorted in preorder. */ | |
834 | ||
9771b263 | 835 | vec<basic_block> |
cad9aa15 MK |
836 | get_all_dominated_blocks (enum cdi_direction dir, basic_block bb) |
837 | { | |
838 | return get_dominated_to_depth (dir, bb, 0); | |
839 | } | |
840 | ||
355be0dc JH |
841 | /* Redirect all edges pointing to BB to TO. */ |
842 | void | |
d47cc544 SB |
843 | redirect_immediate_dominators (enum cdi_direction dir, basic_block bb, |
844 | basic_block to) | |
355be0dc | 845 | { |
2b28c07a JC |
846 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
847 | struct et_node *bb_node, *to_node, *son; | |
b8698a0f | 848 | |
2b28c07a JC |
849 | bb_node = bb->dom[dir_index]; |
850 | to_node = to->dom[dir_index]; | |
d47cc544 | 851 | |
2ba31c05 | 852 | gcc_checking_assert (dom_computed[dir_index]); |
355be0dc | 853 | |
d47cc544 SB |
854 | if (!bb_node->son) |
855 | return; | |
856 | ||
857 | while (bb_node->son) | |
355be0dc | 858 | { |
d47cc544 SB |
859 | son = bb_node->son; |
860 | ||
861 | et_split (son); | |
862 | et_set_father (son, to_node); | |
355be0dc | 863 | } |
d47cc544 | 864 | |
2b28c07a JC |
865 | if (dom_computed[dir_index] == DOM_OK) |
866 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
355be0dc JH |
867 | } |
868 | ||
869 | /* Find first basic block in the tree dominating both BB1 and BB2. */ | |
870 | basic_block | |
d47cc544 | 871 | nearest_common_dominator (enum cdi_direction dir, basic_block bb1, basic_block bb2) |
355be0dc | 872 | { |
2b28c07a JC |
873 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
874 | ||
2ba31c05 | 875 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 876 | |
355be0dc JH |
877 | if (!bb1) |
878 | return bb2; | |
879 | if (!bb2) | |
880 | return bb1; | |
d47cc544 | 881 | |
f883e0a7 | 882 | return (basic_block) et_nca (bb1->dom[dir_index], bb2->dom[dir_index])->data; |
355be0dc JH |
883 | } |
884 | ||
0bca51f0 DN |
885 | |
886 | /* Find the nearest common dominator for the basic blocks in BLOCKS, | |
887 | using dominance direction DIR. */ | |
888 | ||
889 | basic_block | |
890 | nearest_common_dominator_for_set (enum cdi_direction dir, bitmap blocks) | |
891 | { | |
892 | unsigned i, first; | |
893 | bitmap_iterator bi; | |
894 | basic_block dom; | |
b8698a0f | 895 | |
0bca51f0 | 896 | first = bitmap_first_set_bit (blocks); |
06e28de2 | 897 | dom = BASIC_BLOCK_FOR_FN (cfun, first); |
0bca51f0 | 898 | EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi) |
06e28de2 DM |
899 | if (dom != BASIC_BLOCK_FOR_FN (cfun, i)) |
900 | dom = nearest_common_dominator (dir, dom, BASIC_BLOCK_FOR_FN (cfun, i)); | |
0bca51f0 DN |
901 | |
902 | return dom; | |
903 | } | |
904 | ||
b629276a DB |
905 | /* Given a dominator tree, we can determine whether one thing |
906 | dominates another in constant time by using two DFS numbers: | |
907 | ||
908 | 1. The number for when we visit a node on the way down the tree | |
909 | 2. The number for when we visit a node on the way back up the tree | |
910 | ||
911 | You can view these as bounds for the range of dfs numbers the | |
912 | nodes in the subtree of the dominator tree rooted at that node | |
913 | will contain. | |
b8698a0f | 914 | |
b629276a DB |
915 | The dominator tree is always a simple acyclic tree, so there are |
916 | only three possible relations two nodes in the dominator tree have | |
917 | to each other: | |
b8698a0f | 918 | |
b629276a DB |
919 | 1. Node A is above Node B (and thus, Node A dominates node B) |
920 | ||
921 | A | |
922 | | | |
923 | C | |
924 | / \ | |
925 | B D | |
926 | ||
927 | ||
928 | In the above case, DFS_Number_In of A will be <= DFS_Number_In of | |
929 | B, and DFS_Number_Out of A will be >= DFS_Number_Out of B. This is | |
930 | because we must hit A in the dominator tree *before* B on the walk | |
931 | down, and we will hit A *after* B on the walk back up | |
b8698a0f | 932 | |
d8701f02 | 933 | 2. Node A is below node B (and thus, node B dominates node A) |
b8698a0f L |
934 | |
935 | ||
b629276a DB |
936 | B |
937 | | | |
938 | A | |
939 | / \ | |
940 | C D | |
941 | ||
942 | In the above case, DFS_Number_In of A will be >= DFS_Number_In of | |
943 | B, and DFS_Number_Out of A will be <= DFS_Number_Out of B. | |
b8698a0f | 944 | |
b629276a DB |
945 | This is because we must hit A in the dominator tree *after* B on |
946 | the walk down, and we will hit A *before* B on the walk back up | |
b8698a0f | 947 | |
b629276a DB |
948 | 3. Node A and B are siblings (and thus, neither dominates the other) |
949 | ||
950 | C | |
951 | | | |
952 | D | |
953 | / \ | |
954 | A B | |
955 | ||
956 | In the above case, DFS_Number_In of A will *always* be <= | |
957 | DFS_Number_In of B, and DFS_Number_Out of A will *always* be <= | |
958 | DFS_Number_Out of B. This is because we will always finish the dfs | |
959 | walk of one of the subtrees before the other, and thus, the dfs | |
960 | numbers for one subtree can't intersect with the range of dfs | |
961 | numbers for the other subtree. If you swap A and B's position in | |
962 | the dominator tree, the comparison changes direction, but the point | |
963 | is that both comparisons will always go the same way if there is no | |
964 | dominance relationship. | |
965 | ||
966 | Thus, it is sufficient to write | |
967 | ||
968 | A_Dominates_B (node A, node B) | |
969 | { | |
b8698a0f | 970 | return DFS_Number_In(A) <= DFS_Number_In(B) |
b629276a DB |
971 | && DFS_Number_Out (A) >= DFS_Number_Out(B); |
972 | } | |
973 | ||
974 | A_Dominated_by_B (node A, node B) | |
975 | { | |
976 | return DFS_Number_In(A) >= DFS_Number_In(A) | |
977 | && DFS_Number_Out (A) <= DFS_Number_Out(B); | |
978 | } */ | |
0bca51f0 | 979 | |
355be0dc JH |
980 | /* Return TRUE in case BB1 is dominated by BB2. */ |
981 | bool | |
ed7a4b4b | 982 | dominated_by_p (enum cdi_direction dir, const_basic_block bb1, const_basic_block bb2) |
b8698a0f | 983 | { |
2b28c07a JC |
984 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
985 | struct et_node *n1 = bb1->dom[dir_index], *n2 = bb2->dom[dir_index]; | |
b8698a0f | 986 | |
2ba31c05 | 987 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 988 | |
2b28c07a | 989 | if (dom_computed[dir_index] == DOM_OK) |
d47cc544 | 990 | return (n1->dfs_num_in >= n2->dfs_num_in |
6de9cd9a | 991 | && n1->dfs_num_out <= n2->dfs_num_out); |
d47cc544 SB |
992 | |
993 | return et_below (n1, n2); | |
355be0dc JH |
994 | } |
995 | ||
f074ff6c ZD |
996 | /* Returns the entry dfs number for basic block BB, in the direction DIR. */ |
997 | ||
998 | unsigned | |
999 | bb_dom_dfs_in (enum cdi_direction dir, basic_block bb) | |
1000 | { | |
2b28c07a JC |
1001 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1002 | struct et_node *n = bb->dom[dir_index]; | |
f074ff6c | 1003 | |
2ba31c05 | 1004 | gcc_checking_assert (dom_computed[dir_index] == DOM_OK); |
f074ff6c ZD |
1005 | return n->dfs_num_in; |
1006 | } | |
1007 | ||
1008 | /* Returns the exit dfs number for basic block BB, in the direction DIR. */ | |
1009 | ||
1010 | unsigned | |
1011 | bb_dom_dfs_out (enum cdi_direction dir, basic_block bb) | |
1012 | { | |
2b28c07a JC |
1013 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1014 | struct et_node *n = bb->dom[dir_index]; | |
f074ff6c | 1015 | |
2ba31c05 | 1016 | gcc_checking_assert (dom_computed[dir_index] == DOM_OK); |
f074ff6c ZD |
1017 | return n->dfs_num_out; |
1018 | } | |
1019 | ||
355be0dc | 1020 | /* Verify invariants of dominator structure. */ |
24e47c76 | 1021 | DEBUG_FUNCTION void |
d47cc544 | 1022 | verify_dominators (enum cdi_direction dir) |
355be0dc JH |
1023 | { |
1024 | int err = 0; | |
1fc3998d ZD |
1025 | basic_block bb, imm_bb, imm_bb_correct; |
1026 | struct dom_info di; | |
1027 | bool reverse = (dir == CDI_POST_DOMINATORS) ? true : false; | |
355be0dc | 1028 | |
fce22de5 | 1029 | gcc_assert (dom_info_available_p (dir)); |
d47cc544 | 1030 | |
1fc3998d ZD |
1031 | init_dom_info (&di, dir); |
1032 | calc_dfs_tree (&di, reverse); | |
1033 | calc_idoms (&di, reverse); | |
1034 | ||
11cd3bed | 1035 | FOR_EACH_BB_FN (bb, cfun) |
355be0dc | 1036 | { |
1fc3998d ZD |
1037 | imm_bb = get_immediate_dominator (dir, bb); |
1038 | if (!imm_bb) | |
f8032688 | 1039 | { |
66f97d31 | 1040 | error ("dominator of %d status unknown", bb->index); |
355be0dc JH |
1041 | err = 1; |
1042 | } | |
66f97d31 | 1043 | |
1fc3998d ZD |
1044 | imm_bb_correct = di.dfs_to_bb[di.dom[di.dfs_order[bb->index]]]; |
1045 | if (imm_bb != imm_bb_correct) | |
e7bd94cc | 1046 | { |
66f97d31 | 1047 | error ("dominator of %d should be %d, not %d", |
1fc3998d | 1048 | bb->index, imm_bb_correct->index, imm_bb->index); |
66f97d31 | 1049 | err = 1; |
e7bd94cc ZD |
1050 | } |
1051 | } | |
1052 | ||
1fc3998d | 1053 | free_dom_info (&di); |
ced3f397 | 1054 | gcc_assert (!err); |
355be0dc JH |
1055 | } |
1056 | ||
738ed977 ZD |
1057 | /* Determine immediate dominator (or postdominator, according to DIR) of BB, |
1058 | assuming that dominators of other blocks are correct. We also use it to | |
1059 | recompute the dominators in a restricted area, by iterating it until it | |
71cc389b | 1060 | reaches a fixed point. */ |
738ed977 | 1061 | |
355be0dc | 1062 | basic_block |
66f97d31 | 1063 | recompute_dominator (enum cdi_direction dir, basic_block bb) |
355be0dc | 1064 | { |
2b28c07a | 1065 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
738ed977 ZD |
1066 | basic_block dom_bb = NULL; |
1067 | edge e; | |
628f6a4e | 1068 | edge_iterator ei; |
355be0dc | 1069 | |
2ba31c05 | 1070 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 1071 | |
738ed977 ZD |
1072 | if (dir == CDI_DOMINATORS) |
1073 | { | |
628f6a4e | 1074 | FOR_EACH_EDGE (e, ei, bb->preds) |
738ed977 ZD |
1075 | { |
1076 | if (!dominated_by_p (dir, e->src, bb)) | |
1077 | dom_bb = nearest_common_dominator (dir, dom_bb, e->src); | |
1078 | } | |
1079 | } | |
1080 | else | |
1081 | { | |
628f6a4e | 1082 | FOR_EACH_EDGE (e, ei, bb->succs) |
738ed977 ZD |
1083 | { |
1084 | if (!dominated_by_p (dir, e->dest, bb)) | |
1085 | dom_bb = nearest_common_dominator (dir, dom_bb, e->dest); | |
1086 | } | |
1087 | } | |
f8032688 | 1088 | |
738ed977 | 1089 | return dom_bb; |
355be0dc JH |
1090 | } |
1091 | ||
66f97d31 ZD |
1092 | /* Use simple heuristics (see iterate_fix_dominators) to determine dominators |
1093 | of BBS. We assume that all the immediate dominators except for those of the | |
1094 | blocks in BBS are correct. If CONSERVATIVE is true, we also assume that the | |
1095 | currently recorded immediate dominators of blocks in BBS really dominate the | |
1096 | blocks. The basic blocks for that we determine the dominator are removed | |
1097 | from BBS. */ | |
1098 | ||
1099 | static void | |
9771b263 | 1100 | prune_bbs_to_update_dominators (vec<basic_block> bbs, |
66f97d31 ZD |
1101 | bool conservative) |
1102 | { | |
1103 | unsigned i; | |
1104 | bool single; | |
1105 | basic_block bb, dom = NULL; | |
1106 | edge_iterator ei; | |
1107 | edge e; | |
1108 | ||
9771b263 | 1109 | for (i = 0; bbs.iterate (i, &bb);) |
66f97d31 | 1110 | { |
fefa31b5 | 1111 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
66f97d31 ZD |
1112 | goto succeed; |
1113 | ||
1114 | if (single_pred_p (bb)) | |
1115 | { | |
1116 | set_immediate_dominator (CDI_DOMINATORS, bb, single_pred (bb)); | |
1117 | goto succeed; | |
1118 | } | |
1119 | ||
1120 | if (!conservative) | |
1121 | goto fail; | |
1122 | ||
1123 | single = true; | |
1124 | dom = NULL; | |
1125 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1126 | { | |
1127 | if (dominated_by_p (CDI_DOMINATORS, e->src, bb)) | |
1128 | continue; | |
1129 | ||
1130 | if (!dom) | |
1131 | dom = e->src; | |
1132 | else | |
1133 | { | |
1134 | single = false; | |
1135 | dom = nearest_common_dominator (CDI_DOMINATORS, dom, e->src); | |
1136 | } | |
1137 | } | |
1138 | ||
1139 | gcc_assert (dom != NULL); | |
1140 | if (single | |
1141 | || find_edge (dom, bb)) | |
1142 | { | |
1143 | set_immediate_dominator (CDI_DOMINATORS, bb, dom); | |
1144 | goto succeed; | |
1145 | } | |
1146 | ||
1147 | fail: | |
1148 | i++; | |
1149 | continue; | |
1150 | ||
1151 | succeed: | |
9771b263 | 1152 | bbs.unordered_remove (i); |
66f97d31 ZD |
1153 | } |
1154 | } | |
1155 | ||
1156 | /* Returns root of the dominance tree in the direction DIR that contains | |
1157 | BB. */ | |
1158 | ||
1159 | static basic_block | |
1160 | root_of_dom_tree (enum cdi_direction dir, basic_block bb) | |
1161 | { | |
f883e0a7 | 1162 | return (basic_block) et_root (bb->dom[dom_convert_dir_to_idx (dir)])->data; |
66f97d31 ZD |
1163 | } |
1164 | ||
1165 | /* See the comment in iterate_fix_dominators. Finds the immediate dominators | |
1166 | for the sons of Y, found using the SON and BROTHER arrays representing | |
1167 | the dominance tree of graph G. BBS maps the vertices of G to the basic | |
1168 | blocks. */ | |
1169 | ||
1170 | static void | |
9771b263 | 1171 | determine_dominators_for_sons (struct graph *g, vec<basic_block> bbs, |
66f97d31 ZD |
1172 | int y, int *son, int *brother) |
1173 | { | |
1174 | bitmap gprime; | |
1175 | int i, a, nc; | |
9771b263 | 1176 | vec<int> *sccs; |
66f97d31 ZD |
1177 | basic_block bb, dom, ybb; |
1178 | unsigned si; | |
1179 | edge e; | |
1180 | edge_iterator ei; | |
1181 | ||
1182 | if (son[y] == -1) | |
1183 | return; | |
9771b263 | 1184 | if (y == (int) bbs.length ()) |
fefa31b5 | 1185 | ybb = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
66f97d31 | 1186 | else |
9771b263 | 1187 | ybb = bbs[y]; |
66f97d31 ZD |
1188 | |
1189 | if (brother[son[y]] == -1) | |
1190 | { | |
1191 | /* Handle the common case Y has just one son specially. */ | |
9771b263 | 1192 | bb = bbs[son[y]]; |
66f97d31 ZD |
1193 | set_immediate_dominator (CDI_DOMINATORS, bb, |
1194 | recompute_dominator (CDI_DOMINATORS, bb)); | |
1195 | identify_vertices (g, y, son[y]); | |
1196 | return; | |
1197 | } | |
1198 | ||
1199 | gprime = BITMAP_ALLOC (NULL); | |
1200 | for (a = son[y]; a != -1; a = brother[a]) | |
1201 | bitmap_set_bit (gprime, a); | |
1202 | ||
1203 | nc = graphds_scc (g, gprime); | |
1204 | BITMAP_FREE (gprime); | |
1205 | ||
9771b263 DN |
1206 | /* ??? Needed to work around the pre-processor confusion with |
1207 | using a multi-argument template type as macro argument. */ | |
1208 | typedef vec<int> vec_int_heap; | |
1209 | sccs = XCNEWVEC (vec_int_heap, nc); | |
66f97d31 | 1210 | for (a = son[y]; a != -1; a = brother[a]) |
9771b263 | 1211 | sccs[g->vertices[a].component].safe_push (a); |
66f97d31 ZD |
1212 | |
1213 | for (i = nc - 1; i >= 0; i--) | |
1214 | { | |
1215 | dom = NULL; | |
9771b263 | 1216 | FOR_EACH_VEC_ELT (sccs[i], si, a) |
66f97d31 | 1217 | { |
9771b263 | 1218 | bb = bbs[a]; |
66f97d31 ZD |
1219 | FOR_EACH_EDGE (e, ei, bb->preds) |
1220 | { | |
1221 | if (root_of_dom_tree (CDI_DOMINATORS, e->src) != ybb) | |
1222 | continue; | |
1223 | ||
1224 | dom = nearest_common_dominator (CDI_DOMINATORS, dom, e->src); | |
1225 | } | |
1226 | } | |
1227 | ||
1228 | gcc_assert (dom != NULL); | |
9771b263 | 1229 | FOR_EACH_VEC_ELT (sccs[i], si, a) |
66f97d31 | 1230 | { |
9771b263 | 1231 | bb = bbs[a]; |
66f97d31 ZD |
1232 | set_immediate_dominator (CDI_DOMINATORS, bb, dom); |
1233 | } | |
1234 | } | |
1235 | ||
1236 | for (i = 0; i < nc; i++) | |
9771b263 | 1237 | sccs[i].release (); |
66f97d31 ZD |
1238 | free (sccs); |
1239 | ||
1240 | for (a = son[y]; a != -1; a = brother[a]) | |
1241 | identify_vertices (g, y, a); | |
1242 | } | |
1243 | ||
1244 | /* Recompute dominance information for basic blocks in the set BBS. The | |
1245 | function assumes that the immediate dominators of all the other blocks | |
1246 | in CFG are correct, and that there are no unreachable blocks. | |
1247 | ||
1248 | If CONSERVATIVE is true, we additionally assume that all the ancestors of | |
1249 | a block of BBS in the current dominance tree dominate it. */ | |
1250 | ||
355be0dc | 1251 | void |
9771b263 | 1252 | iterate_fix_dominators (enum cdi_direction dir, vec<basic_block> bbs, |
66f97d31 | 1253 | bool conservative) |
355be0dc | 1254 | { |
66f97d31 ZD |
1255 | unsigned i; |
1256 | basic_block bb, dom; | |
1257 | struct graph *g; | |
1258 | int n, y; | |
1259 | size_t dom_i; | |
1260 | edge e; | |
1261 | edge_iterator ei; | |
66f97d31 | 1262 | int *parent, *son, *brother; |
2b28c07a | 1263 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
355be0dc | 1264 | |
66f97d31 ZD |
1265 | /* We only support updating dominators. There are some problems with |
1266 | updating postdominators (need to add fake edges from infinite loops | |
1267 | and noreturn functions), and since we do not currently use | |
1268 | iterate_fix_dominators for postdominators, any attempt to handle these | |
1269 | problems would be unused, untested, and almost surely buggy. We keep | |
1270 | the DIR argument for consistency with the rest of the dominator analysis | |
1271 | interface. */ | |
2ba31c05 | 1272 | gcc_checking_assert (dir == CDI_DOMINATORS && dom_computed[dir_index]); |
d47cc544 | 1273 | |
66f97d31 ZD |
1274 | /* The algorithm we use takes inspiration from the following papers, although |
1275 | the details are quite different from any of them: | |
1276 | ||
1277 | [1] G. Ramalingam, T. Reps, An Incremental Algorithm for Maintaining the | |
1278 | Dominator Tree of a Reducible Flowgraph | |
1279 | [2] V. C. Sreedhar, G. R. Gao, Y.-F. Lee: Incremental computation of | |
1280 | dominator trees | |
1281 | [3] K. D. Cooper, T. J. Harvey and K. Kennedy: A Simple, Fast Dominance | |
1282 | Algorithm | |
1283 | ||
1284 | First, we use the following heuristics to decrease the size of the BBS | |
1285 | set: | |
1286 | a) if BB has a single predecessor, then its immediate dominator is this | |
1287 | predecessor | |
1288 | additionally, if CONSERVATIVE is true: | |
1289 | b) if all the predecessors of BB except for one (X) are dominated by BB, | |
1290 | then X is the immediate dominator of BB | |
1291 | c) if the nearest common ancestor of the predecessors of BB is X and | |
1292 | X -> BB is an edge in CFG, then X is the immediate dominator of BB | |
1293 | ||
1294 | Then, we need to establish the dominance relation among the basic blocks | |
1295 | in BBS. We split the dominance tree by removing the immediate dominator | |
0d52bcc1 | 1296 | edges from BBS, creating a forest F. We form a graph G whose vertices |
66f97d31 | 1297 | are BBS and ENTRY and X -> Y is an edge of G if there exists an edge |
0d52bcc1 | 1298 | X' -> Y in CFG such that X' belongs to the tree of the dominance forest |
66f97d31 ZD |
1299 | whose root is X. We then determine dominance tree of G. Note that |
1300 | for X, Y in BBS, X dominates Y in CFG if and only if X dominates Y in G. | |
1301 | In this step, we can use arbitrary algorithm to determine dominators. | |
1302 | We decided to prefer the algorithm [3] to the algorithm of | |
1303 | Lengauer and Tarjan, since the set BBS is usually small (rarely exceeding | |
1304 | 10 during gcc bootstrap), and [3] should perform better in this case. | |
1305 | ||
1306 | Finally, we need to determine the immediate dominators for the basic | |
1307 | blocks of BBS. If the immediate dominator of X in G is Y, then | |
1308 | the immediate dominator of X in CFG belongs to the tree of F rooted in | |
1309 | Y. We process the dominator tree T of G recursively, starting from leaves. | |
1310 | Suppose that X_1, X_2, ..., X_k are the sons of Y in T, and that the | |
1311 | subtrees of the dominance tree of CFG rooted in X_i are already correct. | |
1312 | Let G' be the subgraph of G induced by {X_1, X_2, ..., X_k}. We make | |
1313 | the following observations: | |
1314 | (i) the immediate dominator of all blocks in a strongly connected | |
1315 | component of G' is the same | |
1316 | (ii) if X has no predecessors in G', then the immediate dominator of X | |
1317 | is the nearest common ancestor of the predecessors of X in the | |
1318 | subtree of F rooted in Y | |
1319 | Therefore, it suffices to find the topological ordering of G', and | |
1320 | process the nodes X_i in this order using the rules (i) and (ii). | |
1321 | Then, we contract all the nodes X_i with Y in G, so that the further | |
1322 | steps work correctly. */ | |
1323 | ||
1324 | if (!conservative) | |
1325 | { | |
1326 | /* Split the tree now. If the idoms of blocks in BBS are not | |
1327 | conservatively correct, setting the dominators using the | |
1328 | heuristics in prune_bbs_to_update_dominators could | |
1329 | create cycles in the dominance "tree", and cause ICE. */ | |
9771b263 | 1330 | FOR_EACH_VEC_ELT (bbs, i, bb) |
66f97d31 ZD |
1331 | set_immediate_dominator (CDI_DOMINATORS, bb, NULL); |
1332 | } | |
1333 | ||
1334 | prune_bbs_to_update_dominators (bbs, conservative); | |
9771b263 | 1335 | n = bbs.length (); |
66f97d31 ZD |
1336 | |
1337 | if (n == 0) | |
1338 | return; | |
e7bd94cc | 1339 | |
66f97d31 | 1340 | if (n == 1) |
355be0dc | 1341 | { |
9771b263 | 1342 | bb = bbs[0]; |
66f97d31 ZD |
1343 | set_immediate_dominator (CDI_DOMINATORS, bb, |
1344 | recompute_dominator (CDI_DOMINATORS, bb)); | |
1345 | return; | |
1346 | } | |
1347 | ||
1348 | /* Construct the graph G. */ | |
1eb68d2d | 1349 | hash_map<basic_block, int> map (251); |
9771b263 | 1350 | FOR_EACH_VEC_ELT (bbs, i, bb) |
66f97d31 ZD |
1351 | { |
1352 | /* If the dominance tree is conservatively correct, split it now. */ | |
1353 | if (conservative) | |
1354 | set_immediate_dominator (CDI_DOMINATORS, bb, NULL); | |
1eb68d2d | 1355 | map.put (bb, i); |
66f97d31 | 1356 | } |
1eb68d2d | 1357 | map.put (ENTRY_BLOCK_PTR_FOR_FN (cfun), n); |
66f97d31 ZD |
1358 | |
1359 | g = new_graph (n + 1); | |
1360 | for (y = 0; y < g->n_vertices; y++) | |
1361 | g->vertices[y].data = BITMAP_ALLOC (NULL); | |
9771b263 | 1362 | FOR_EACH_VEC_ELT (bbs, i, bb) |
66f97d31 ZD |
1363 | { |
1364 | FOR_EACH_EDGE (e, ei, bb->preds) | |
355be0dc | 1365 | { |
66f97d31 ZD |
1366 | dom = root_of_dom_tree (CDI_DOMINATORS, e->src); |
1367 | if (dom == bb) | |
1368 | continue; | |
1369 | ||
1eb68d2d | 1370 | dom_i = *map.get (dom); |
66f97d31 ZD |
1371 | |
1372 | /* Do not include parallel edges to G. */ | |
fcaa4ca4 | 1373 | if (!bitmap_set_bit ((bitmap) g->vertices[dom_i].data, i)) |
66f97d31 ZD |
1374 | continue; |
1375 | ||
66f97d31 | 1376 | add_edge (g, dom_i, i); |
f8032688 MM |
1377 | } |
1378 | } | |
66f97d31 ZD |
1379 | for (y = 0; y < g->n_vertices; y++) |
1380 | BITMAP_FREE (g->vertices[y].data); | |
66f97d31 ZD |
1381 | |
1382 | /* Find the dominator tree of G. */ | |
1383 | son = XNEWVEC (int, n + 1); | |
1384 | brother = XNEWVEC (int, n + 1); | |
1385 | parent = XNEWVEC (int, n + 1); | |
1386 | graphds_domtree (g, n, parent, son, brother); | |
1387 | ||
1388 | /* Finally, traverse the tree and find the immediate dominators. */ | |
1389 | for (y = n; son[y] != -1; y = son[y]) | |
1390 | continue; | |
1391 | while (y != -1) | |
1392 | { | |
1393 | determine_dominators_for_sons (g, bbs, y, son, brother); | |
1394 | ||
1395 | if (brother[y] != -1) | |
1396 | { | |
1397 | y = brother[y]; | |
1398 | while (son[y] != -1) | |
1399 | y = son[y]; | |
1400 | } | |
1401 | else | |
1402 | y = parent[y]; | |
1403 | } | |
1404 | ||
1405 | free (son); | |
1406 | free (brother); | |
1407 | free (parent); | |
e7bd94cc | 1408 | |
66f97d31 | 1409 | free_graph (g); |
355be0dc | 1410 | } |
f8032688 | 1411 | |
355be0dc | 1412 | void |
d47cc544 | 1413 | add_to_dominance_info (enum cdi_direction dir, basic_block bb) |
355be0dc | 1414 | { |
2b28c07a JC |
1415 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1416 | ||
2ba31c05 | 1417 | gcc_checking_assert (dom_computed[dir_index] && !bb->dom[dir_index]); |
d47cc544 | 1418 | |
2b28c07a | 1419 | n_bbs_in_dom_tree[dir_index]++; |
b8698a0f | 1420 | |
2b28c07a | 1421 | bb->dom[dir_index] = et_new_tree (bb); |
d47cc544 | 1422 | |
2b28c07a JC |
1423 | if (dom_computed[dir_index] == DOM_OK) |
1424 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
355be0dc JH |
1425 | } |
1426 | ||
1427 | void | |
d47cc544 SB |
1428 | delete_from_dominance_info (enum cdi_direction dir, basic_block bb) |
1429 | { | |
2b28c07a | 1430 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
d47cc544 | 1431 | |
2ba31c05 | 1432 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 1433 | |
2b28c07a JC |
1434 | et_free_tree (bb->dom[dir_index]); |
1435 | bb->dom[dir_index] = NULL; | |
1436 | n_bbs_in_dom_tree[dir_index]--; | |
1437 | ||
1438 | if (dom_computed[dir_index] == DOM_OK) | |
1439 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
d47cc544 SB |
1440 | } |
1441 | ||
1442 | /* Returns the first son of BB in the dominator or postdominator tree | |
1443 | as determined by DIR. */ | |
1444 | ||
1445 | basic_block | |
1446 | first_dom_son (enum cdi_direction dir, basic_block bb) | |
355be0dc | 1447 | { |
2b28c07a JC |
1448 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1449 | struct et_node *son = bb->dom[dir_index]->son; | |
d47cc544 | 1450 | |
f883e0a7 | 1451 | return (basic_block) (son ? son->data : NULL); |
d47cc544 SB |
1452 | } |
1453 | ||
1454 | /* Returns the next dominance son after BB in the dominator or postdominator | |
1455 | tree as determined by DIR, or NULL if it was the last one. */ | |
1456 | ||
1457 | basic_block | |
1458 | next_dom_son (enum cdi_direction dir, basic_block bb) | |
1459 | { | |
2b28c07a JC |
1460 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1461 | struct et_node *next = bb->dom[dir_index]->right; | |
d47cc544 | 1462 | |
f883e0a7 | 1463 | return (basic_block) (next->father->son == next ? NULL : next->data); |
355be0dc JH |
1464 | } |
1465 | ||
2b28c07a JC |
1466 | /* Return dominance availability for dominance info DIR. */ |
1467 | ||
1468 | enum dom_state | |
e3f613cb | 1469 | dom_info_state (function *fn, enum cdi_direction dir) |
2b28c07a | 1470 | { |
e3f613cb RB |
1471 | if (!fn->cfg) |
1472 | return DOM_NONE; | |
1473 | ||
2b28c07a | 1474 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
e3f613cb RB |
1475 | return fn->cfg->x_dom_computed[dir_index]; |
1476 | } | |
2b28c07a | 1477 | |
e3f613cb RB |
1478 | enum dom_state |
1479 | dom_info_state (enum cdi_direction dir) | |
1480 | { | |
1481 | return dom_info_state (cfun, dir); | |
2b28c07a JC |
1482 | } |
1483 | ||
1484 | /* Set the dominance availability for dominance info DIR to NEW_STATE. */ | |
1485 | ||
1486 | void | |
1487 | set_dom_info_availability (enum cdi_direction dir, enum dom_state new_state) | |
1488 | { | |
1489 | unsigned int dir_index = dom_convert_dir_to_idx (dir); | |
1490 | ||
1491 | dom_computed[dir_index] = new_state; | |
1492 | } | |
1493 | ||
fce22de5 ZD |
1494 | /* Returns true if dominance information for direction DIR is available. */ |
1495 | ||
1496 | bool | |
e3f613cb | 1497 | dom_info_available_p (function *fn, enum cdi_direction dir) |
fce22de5 | 1498 | { |
e3f613cb RB |
1499 | return dom_info_state (fn, dir) != DOM_NONE; |
1500 | } | |
2b28c07a | 1501 | |
e3f613cb RB |
1502 | bool |
1503 | dom_info_available_p (enum cdi_direction dir) | |
1504 | { | |
1505 | return dom_info_available_p (cfun, dir); | |
fce22de5 ZD |
1506 | } |
1507 | ||
24e47c76 | 1508 | DEBUG_FUNCTION void |
d47cc544 | 1509 | debug_dominance_info (enum cdi_direction dir) |
355be0dc JH |
1510 | { |
1511 | basic_block bb, bb2; | |
11cd3bed | 1512 | FOR_EACH_BB_FN (bb, cfun) |
d47cc544 | 1513 | if ((bb2 = get_immediate_dominator (dir, bb))) |
355be0dc | 1514 | fprintf (stderr, "%i %i\n", bb->index, bb2->index); |
f8032688 | 1515 | } |
1fc3998d ZD |
1516 | |
1517 | /* Prints to stderr representation of the dominance tree (for direction DIR) | |
cea618ac | 1518 | rooted in ROOT, indented by INDENT tabulators. If INDENT_FIRST is false, |
1fc3998d ZD |
1519 | the first line of the output is not indented. */ |
1520 | ||
1521 | static void | |
1522 | debug_dominance_tree_1 (enum cdi_direction dir, basic_block root, | |
1523 | unsigned indent, bool indent_first) | |
1524 | { | |
1525 | basic_block son; | |
1526 | unsigned i; | |
1527 | bool first = true; | |
1528 | ||
1529 | if (indent_first) | |
1530 | for (i = 0; i < indent; i++) | |
1531 | fprintf (stderr, "\t"); | |
1532 | fprintf (stderr, "%d\t", root->index); | |
1533 | ||
1534 | for (son = first_dom_son (dir, root); | |
1535 | son; | |
1536 | son = next_dom_son (dir, son)) | |
1537 | { | |
1538 | debug_dominance_tree_1 (dir, son, indent + 1, !first); | |
1539 | first = false; | |
1540 | } | |
1541 | ||
1542 | if (first) | |
1543 | fprintf (stderr, "\n"); | |
1544 | } | |
1545 | ||
1546 | /* Prints to stderr representation of the dominance tree (for direction DIR) | |
1547 | rooted in ROOT. */ | |
1548 | ||
24e47c76 | 1549 | DEBUG_FUNCTION void |
1fc3998d ZD |
1550 | debug_dominance_tree (enum cdi_direction dir, basic_block root) |
1551 | { | |
1552 | debug_dominance_tree_1 (dir, root, 0, false); | |
1553 | } |