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f8032688 | 1 | /* Calculate (post)dominators in slightly super-linear time. |
5624e564 | 2 | Copyright (C) 2000-2015 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" |
60393bbc | 42 | #include "predict.h" |
60393bbc AM |
43 | #include "function.h" |
44 | #include "dominance.h" | |
45 | #include "cfg.h" | |
46 | #include "cfganal.h" | |
f8032688 | 47 | #include "basic-block.h" |
718f9c0f | 48 | #include "diagnostic-core.h" |
64afff5b | 49 | #include "alloc-pool.h" |
355be0dc | 50 | #include "et-forest.h" |
74c96e0c | 51 | #include "timevar.h" |
66f97d31 | 52 | #include "graphds.h" |
7a8cba34 | 53 | #include "bitmap.h" |
f8032688 | 54 | |
f8032688 MM |
55 | /* We name our nodes with integers, beginning with 1. Zero is reserved for |
56 | 'undefined' or 'end of list'. The name of each node is given by the dfs | |
57 | number of the corresponding basic block. Please note, that we include the | |
58 | artificial ENTRY_BLOCK (or EXIT_BLOCK in the post-dom case) in our lists to | |
24bd1a0b | 59 | support multiple entry points. Its dfs number is of course 1. */ |
f8032688 MM |
60 | |
61 | /* Type of Basic Block aka. TBB */ | |
62 | typedef unsigned int TBB; | |
63 | ||
64 | /* We work in a poor-mans object oriented fashion, and carry an instance of | |
65 | this structure through all our 'methods'. It holds various arrays | |
66 | reflecting the (sub)structure of the flowgraph. Most of them are of type | |
67 | TBB and are also indexed by TBB. */ | |
68 | ||
69 | struct dom_info | |
70 | { | |
71 | /* The parent of a node in the DFS tree. */ | |
72 | TBB *dfs_parent; | |
73 | /* For a node x key[x] is roughly the node nearest to the root from which | |
74 | exists a way to x only over nodes behind x. Such a node is also called | |
75 | semidominator. */ | |
76 | TBB *key; | |
77 | /* The value in path_min[x] is the node y on the path from x to the root of | |
78 | the tree x is in with the smallest key[y]. */ | |
79 | TBB *path_min; | |
80 | /* bucket[x] points to the first node of the set of nodes having x as key. */ | |
81 | TBB *bucket; | |
82 | /* And next_bucket[x] points to the next node. */ | |
83 | TBB *next_bucket; | |
84 | /* After the algorithm is done, dom[x] contains the immediate dominator | |
85 | of x. */ | |
86 | TBB *dom; | |
87 | ||
88 | /* The following few fields implement the structures needed for disjoint | |
89 | sets. */ | |
fa10beec | 90 | /* set_chain[x] is the next node on the path from x to the representative |
f8032688 MM |
91 | of the set containing x. If set_chain[x]==0 then x is a root. */ |
92 | TBB *set_chain; | |
93 | /* set_size[x] is the number of elements in the set named by x. */ | |
94 | unsigned int *set_size; | |
95 | /* set_child[x] is used for balancing the tree representing a set. It can | |
96 | be understood as the next sibling of x. */ | |
97 | TBB *set_child; | |
98 | ||
99 | /* If b is the number of a basic block (BB->index), dfs_order[b] is the | |
100 | number of that node in DFS order counted from 1. This is an index | |
101 | into most of the other arrays in this structure. */ | |
102 | TBB *dfs_order; | |
09da1532 | 103 | /* If x is the DFS-index of a node which corresponds with a basic block, |
f8032688 MM |
104 | dfs_to_bb[x] is that basic block. Note, that in our structure there are |
105 | more nodes that basic blocks, so only dfs_to_bb[dfs_order[bb->index]]==bb | |
106 | is true for every basic block bb, but not the opposite. */ | |
107 | basic_block *dfs_to_bb; | |
108 | ||
26e0e410 | 109 | /* This is the next free DFS number when creating the DFS tree. */ |
f8032688 MM |
110 | unsigned int dfsnum; |
111 | /* The number of nodes in the DFS tree (==dfsnum-1). */ | |
112 | unsigned int nodes; | |
26e0e410 RH |
113 | |
114 | /* Blocks with bits set here have a fake edge to EXIT. These are used | |
115 | to turn a DFS forest into a proper tree. */ | |
116 | bitmap fake_exit_edge; | |
f8032688 MM |
117 | }; |
118 | ||
26e0e410 | 119 | static void init_dom_info (struct dom_info *, enum cdi_direction); |
7080f735 | 120 | static void free_dom_info (struct dom_info *); |
2b28c07a JC |
121 | static void calc_dfs_tree_nonrec (struct dom_info *, basic_block, bool); |
122 | static void calc_dfs_tree (struct dom_info *, bool); | |
7080f735 AJ |
123 | static void compress (struct dom_info *, TBB); |
124 | static TBB eval (struct dom_info *, TBB); | |
125 | static void link_roots (struct dom_info *, TBB, TBB); | |
2b28c07a | 126 | static void calc_idoms (struct dom_info *, bool); |
d47cc544 | 127 | void debug_dominance_info (enum cdi_direction); |
1fc3998d | 128 | void debug_dominance_tree (enum cdi_direction, basic_block); |
f8032688 MM |
129 | |
130 | /* Helper macro for allocating and initializing an array, | |
131 | for aesthetic reasons. */ | |
132 | #define init_ar(var, type, num, content) \ | |
3a538a66 KH |
133 | do \ |
134 | { \ | |
135 | unsigned int i = 1; /* Catch content == i. */ \ | |
136 | if (! (content)) \ | |
5ed6ace5 | 137 | (var) = XCNEWVEC (type, num); \ |
3a538a66 KH |
138 | else \ |
139 | { \ | |
5ed6ace5 | 140 | (var) = XNEWVEC (type, (num)); \ |
3a538a66 KH |
141 | for (i = 0; i < num; i++) \ |
142 | (var)[i] = (content); \ | |
143 | } \ | |
144 | } \ | |
145 | while (0) | |
f8032688 MM |
146 | |
147 | /* Allocate all needed memory in a pessimistic fashion (so we round up). | |
4912a07c | 148 | This initializes the contents of DI, which already must be allocated. */ |
f8032688 MM |
149 | |
150 | static void | |
26e0e410 | 151 | init_dom_info (struct dom_info *di, enum cdi_direction dir) |
f8032688 | 152 | { |
6fb5fa3c | 153 | /* We need memory for n_basic_blocks nodes. */ |
0cae8d31 | 154 | unsigned int num = n_basic_blocks_for_fn (cfun); |
f8032688 MM |
155 | init_ar (di->dfs_parent, TBB, num, 0); |
156 | init_ar (di->path_min, TBB, num, i); | |
157 | init_ar (di->key, TBB, num, i); | |
158 | init_ar (di->dom, TBB, num, 0); | |
159 | ||
160 | init_ar (di->bucket, TBB, num, 0); | |
161 | init_ar (di->next_bucket, TBB, num, 0); | |
162 | ||
163 | init_ar (di->set_chain, TBB, num, 0); | |
164 | init_ar (di->set_size, unsigned int, num, 1); | |
165 | init_ar (di->set_child, TBB, num, 0); | |
166 | ||
8b1c6fd7 DM |
167 | init_ar (di->dfs_order, TBB, |
168 | (unsigned int) last_basic_block_for_fn (cfun) + 1, 0); | |
f8032688 MM |
169 | init_ar (di->dfs_to_bb, basic_block, num, 0); |
170 | ||
171 | di->dfsnum = 1; | |
172 | di->nodes = 0; | |
26e0e410 | 173 | |
2b28c07a JC |
174 | switch (dir) |
175 | { | |
176 | case CDI_DOMINATORS: | |
177 | di->fake_exit_edge = NULL; | |
178 | break; | |
179 | case CDI_POST_DOMINATORS: | |
180 | di->fake_exit_edge = BITMAP_ALLOC (NULL); | |
181 | break; | |
182 | default: | |
183 | gcc_unreachable (); | |
184 | break; | |
185 | } | |
f8032688 MM |
186 | } |
187 | ||
188 | #undef init_ar | |
189 | ||
2b28c07a JC |
190 | /* Map dominance calculation type to array index used for various |
191 | dominance information arrays. This version is simple -- it will need | |
192 | to be modified, obviously, if additional values are added to | |
193 | cdi_direction. */ | |
194 | ||
195 | static unsigned int | |
196 | dom_convert_dir_to_idx (enum cdi_direction dir) | |
197 | { | |
2ba31c05 | 198 | gcc_checking_assert (dir == CDI_DOMINATORS || dir == CDI_POST_DOMINATORS); |
2b28c07a JC |
199 | return dir - 1; |
200 | } | |
201 | ||
f8032688 MM |
202 | /* Free all allocated memory in DI, but not DI itself. */ |
203 | ||
204 | static void | |
7080f735 | 205 | free_dom_info (struct dom_info *di) |
f8032688 MM |
206 | { |
207 | free (di->dfs_parent); | |
208 | free (di->path_min); | |
209 | free (di->key); | |
210 | free (di->dom); | |
211 | free (di->bucket); | |
212 | free (di->next_bucket); | |
213 | free (di->set_chain); | |
214 | free (di->set_size); | |
215 | free (di->set_child); | |
216 | free (di->dfs_order); | |
217 | free (di->dfs_to_bb); | |
8bdbfff5 | 218 | BITMAP_FREE (di->fake_exit_edge); |
f8032688 MM |
219 | } |
220 | ||
221 | /* The nonrecursive variant of creating a DFS tree. DI is our working | |
222 | structure, BB the starting basic block for this tree and REVERSE | |
223 | is true, if predecessors should be visited instead of successors of a | |
224 | node. After this is done all nodes reachable from BB were visited, have | |
225 | assigned their dfs number and are linked together to form a tree. */ | |
226 | ||
227 | static void | |
2b28c07a | 228 | calc_dfs_tree_nonrec (struct dom_info *di, basic_block bb, bool reverse) |
f8032688 | 229 | { |
f8032688 MM |
230 | /* We call this _only_ if bb is not already visited. */ |
231 | edge e; | |
232 | TBB child_i, my_i = 0; | |
628f6a4e BE |
233 | edge_iterator *stack; |
234 | edge_iterator ei, einext; | |
f8032688 | 235 | int sp; |
6626665f | 236 | /* Start block (the entry block for forward problem, exit block for backward |
f8032688 MM |
237 | problem). */ |
238 | basic_block en_block; | |
239 | /* Ending block. */ | |
240 | basic_block ex_block; | |
241 | ||
0cae8d31 | 242 | stack = XNEWVEC (edge_iterator, n_basic_blocks_for_fn (cfun) + 1); |
f8032688 MM |
243 | sp = 0; |
244 | ||
245 | /* Initialize our border blocks, and the first edge. */ | |
246 | if (reverse) | |
247 | { | |
628f6a4e | 248 | ei = ei_start (bb->preds); |
fefa31b5 DM |
249 | en_block = EXIT_BLOCK_PTR_FOR_FN (cfun); |
250 | ex_block = ENTRY_BLOCK_PTR_FOR_FN (cfun); | |
f8032688 MM |
251 | } |
252 | else | |
253 | { | |
628f6a4e | 254 | ei = ei_start (bb->succs); |
fefa31b5 DM |
255 | en_block = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
256 | ex_block = EXIT_BLOCK_PTR_FOR_FN (cfun); | |
f8032688 MM |
257 | } |
258 | ||
259 | /* When the stack is empty we break out of this loop. */ | |
260 | while (1) | |
261 | { | |
262 | basic_block bn; | |
263 | ||
264 | /* This loop traverses edges e in depth first manner, and fills the | |
265 | stack. */ | |
628f6a4e | 266 | while (!ei_end_p (ei)) |
f8032688 | 267 | { |
628f6a4e | 268 | e = ei_edge (ei); |
f8032688 MM |
269 | |
270 | /* Deduce from E the current and the next block (BB and BN), and the | |
271 | next edge. */ | |
272 | if (reverse) | |
273 | { | |
274 | bn = e->src; | |
275 | ||
276 | /* If the next node BN is either already visited or a border | |
277 | block the current edge is useless, and simply overwritten | |
278 | with the next edge out of the current node. */ | |
0b17ab2f | 279 | if (bn == ex_block || di->dfs_order[bn->index]) |
f8032688 | 280 | { |
628f6a4e | 281 | ei_next (&ei); |
f8032688 MM |
282 | continue; |
283 | } | |
284 | bb = e->dest; | |
628f6a4e | 285 | einext = ei_start (bn->preds); |
f8032688 MM |
286 | } |
287 | else | |
288 | { | |
289 | bn = e->dest; | |
0b17ab2f | 290 | if (bn == ex_block || di->dfs_order[bn->index]) |
f8032688 | 291 | { |
628f6a4e | 292 | ei_next (&ei); |
f8032688 MM |
293 | continue; |
294 | } | |
295 | bb = e->src; | |
628f6a4e | 296 | einext = ei_start (bn->succs); |
f8032688 MM |
297 | } |
298 | ||
ced3f397 | 299 | gcc_assert (bn != en_block); |
f8032688 MM |
300 | |
301 | /* Fill the DFS tree info calculatable _before_ recursing. */ | |
302 | if (bb != en_block) | |
0b17ab2f | 303 | my_i = di->dfs_order[bb->index]; |
f8032688 | 304 | else |
8b1c6fd7 | 305 | my_i = di->dfs_order[last_basic_block_for_fn (cfun)]; |
0b17ab2f | 306 | child_i = di->dfs_order[bn->index] = di->dfsnum++; |
f8032688 MM |
307 | di->dfs_to_bb[child_i] = bn; |
308 | di->dfs_parent[child_i] = my_i; | |
309 | ||
310 | /* Save the current point in the CFG on the stack, and recurse. */ | |
628f6a4e BE |
311 | stack[sp++] = ei; |
312 | ei = einext; | |
f8032688 MM |
313 | } |
314 | ||
315 | if (!sp) | |
316 | break; | |
628f6a4e | 317 | ei = stack[--sp]; |
f8032688 MM |
318 | |
319 | /* OK. The edge-list was exhausted, meaning normally we would | |
320 | end the recursion. After returning from the recursive call, | |
321 | there were (may be) other statements which were run after a | |
322 | child node was completely considered by DFS. Here is the | |
323 | point to do it in the non-recursive variant. | |
324 | E.g. The block just completed is in e->dest for forward DFS, | |
325 | the block not yet completed (the parent of the one above) | |
326 | in e->src. This could be used e.g. for computing the number of | |
327 | descendants or the tree depth. */ | |
628f6a4e | 328 | ei_next (&ei); |
f8032688 MM |
329 | } |
330 | free (stack); | |
331 | } | |
332 | ||
333 | /* The main entry for calculating the DFS tree or forest. DI is our working | |
334 | structure and REVERSE is true, if we are interested in the reverse flow | |
335 | graph. In that case the result is not necessarily a tree but a forest, | |
336 | because there may be nodes from which the EXIT_BLOCK is unreachable. */ | |
337 | ||
338 | static void | |
2b28c07a | 339 | calc_dfs_tree (struct dom_info *di, bool reverse) |
f8032688 MM |
340 | { |
341 | /* The first block is the ENTRY_BLOCK (or EXIT_BLOCK if REVERSE). */ | |
fefa31b5 DM |
342 | basic_block begin = (reverse |
343 | ? EXIT_BLOCK_PTR_FOR_FN (cfun) : ENTRY_BLOCK_PTR_FOR_FN (cfun)); | |
8b1c6fd7 | 344 | di->dfs_order[last_basic_block_for_fn (cfun)] = di->dfsnum; |
f8032688 MM |
345 | di->dfs_to_bb[di->dfsnum] = begin; |
346 | di->dfsnum++; | |
347 | ||
348 | calc_dfs_tree_nonrec (di, begin, reverse); | |
349 | ||
350 | if (reverse) | |
351 | { | |
352 | /* In the post-dom case we may have nodes without a path to EXIT_BLOCK. | |
353 | They are reverse-unreachable. In the dom-case we disallow such | |
26e0e410 RH |
354 | nodes, but in post-dom we have to deal with them. |
355 | ||
356 | There are two situations in which this occurs. First, noreturn | |
357 | functions. Second, infinite loops. In the first case we need to | |
358 | pretend that there is an edge to the exit block. In the second | |
359 | case, we wind up with a forest. We need to process all noreturn | |
360 | blocks before we know if we've got any infinite loops. */ | |
361 | ||
e0082a72 | 362 | basic_block b; |
26e0e410 RH |
363 | bool saw_unconnected = false; |
364 | ||
4f42035e | 365 | FOR_EACH_BB_REVERSE_FN (b, cfun) |
f8032688 | 366 | { |
628f6a4e | 367 | if (EDGE_COUNT (b->succs) > 0) |
26e0e410 RH |
368 | { |
369 | if (di->dfs_order[b->index] == 0) | |
370 | saw_unconnected = true; | |
371 | continue; | |
372 | } | |
373 | bitmap_set_bit (di->fake_exit_edge, b->index); | |
0b17ab2f | 374 | di->dfs_order[b->index] = di->dfsnum; |
f8032688 | 375 | di->dfs_to_bb[di->dfsnum] = b; |
8b1c6fd7 DM |
376 | di->dfs_parent[di->dfsnum] = |
377 | di->dfs_order[last_basic_block_for_fn (cfun)]; | |
f8032688 MM |
378 | di->dfsnum++; |
379 | calc_dfs_tree_nonrec (di, b, reverse); | |
380 | } | |
26e0e410 RH |
381 | |
382 | if (saw_unconnected) | |
383 | { | |
4f42035e | 384 | FOR_EACH_BB_REVERSE_FN (b, cfun) |
26e0e410 | 385 | { |
03b06a83 | 386 | basic_block b2; |
26e0e410 RH |
387 | if (di->dfs_order[b->index]) |
388 | continue; | |
03b06a83 SB |
389 | b2 = dfs_find_deadend (b); |
390 | gcc_checking_assert (di->dfs_order[b2->index] == 0); | |
391 | bitmap_set_bit (di->fake_exit_edge, b2->index); | |
392 | di->dfs_order[b2->index] = di->dfsnum; | |
393 | di->dfs_to_bb[di->dfsnum] = b2; | |
8b1c6fd7 DM |
394 | di->dfs_parent[di->dfsnum] = |
395 | di->dfs_order[last_basic_block_for_fn (cfun)]; | |
26e0e410 | 396 | di->dfsnum++; |
03b06a83 SB |
397 | calc_dfs_tree_nonrec (di, b2, reverse); |
398 | gcc_checking_assert (di->dfs_order[b->index]); | |
26e0e410 RH |
399 | } |
400 | } | |
f8032688 MM |
401 | } |
402 | ||
403 | di->nodes = di->dfsnum - 1; | |
404 | ||
24bd1a0b | 405 | /* This aborts e.g. when there is _no_ path from ENTRY to EXIT at all. */ |
0cae8d31 | 406 | gcc_assert (di->nodes == (unsigned int) n_basic_blocks_for_fn (cfun) - 1); |
f8032688 MM |
407 | } |
408 | ||
409 | /* Compress the path from V to the root of its set and update path_min at the | |
410 | same time. After compress(di, V) set_chain[V] is the root of the set V is | |
411 | in and path_min[V] is the node with the smallest key[] value on the path | |
412 | from V to that root. */ | |
413 | ||
414 | static void | |
7080f735 | 415 | compress (struct dom_info *di, TBB v) |
f8032688 MM |
416 | { |
417 | /* Btw. It's not worth to unrecurse compress() as the depth is usually not | |
418 | greater than 5 even for huge graphs (I've not seen call depth > 4). | |
419 | Also performance wise compress() ranges _far_ behind eval(). */ | |
420 | TBB parent = di->set_chain[v]; | |
421 | if (di->set_chain[parent]) | |
422 | { | |
423 | compress (di, parent); | |
424 | if (di->key[di->path_min[parent]] < di->key[di->path_min[v]]) | |
425 | di->path_min[v] = di->path_min[parent]; | |
426 | di->set_chain[v] = di->set_chain[parent]; | |
427 | } | |
428 | } | |
429 | ||
430 | /* Compress the path from V to the set root of V if needed (when the root has | |
431 | changed since the last call). Returns the node with the smallest key[] | |
432 | value on the path from V to the root. */ | |
433 | ||
434 | static inline TBB | |
7080f735 | 435 | eval (struct dom_info *di, TBB v) |
f8032688 | 436 | { |
fa10beec | 437 | /* The representative of the set V is in, also called root (as the set |
f8032688 MM |
438 | representation is a tree). */ |
439 | TBB rep = di->set_chain[v]; | |
440 | ||
441 | /* V itself is the root. */ | |
442 | if (!rep) | |
443 | return di->path_min[v]; | |
444 | ||
445 | /* Compress only if necessary. */ | |
446 | if (di->set_chain[rep]) | |
447 | { | |
448 | compress (di, v); | |
449 | rep = di->set_chain[v]; | |
450 | } | |
451 | ||
452 | if (di->key[di->path_min[rep]] >= di->key[di->path_min[v]]) | |
453 | return di->path_min[v]; | |
454 | else | |
455 | return di->path_min[rep]; | |
456 | } | |
457 | ||
458 | /* This essentially merges the two sets of V and W, giving a single set with | |
459 | the new root V. The internal representation of these disjoint sets is a | |
460 | balanced tree. Currently link(V,W) is only used with V being the parent | |
461 | of W. */ | |
462 | ||
463 | static void | |
7080f735 | 464 | link_roots (struct dom_info *di, TBB v, TBB w) |
f8032688 MM |
465 | { |
466 | TBB s = w; | |
467 | ||
468 | /* Rebalance the tree. */ | |
469 | while (di->key[di->path_min[w]] < di->key[di->path_min[di->set_child[s]]]) | |
470 | { | |
471 | if (di->set_size[s] + di->set_size[di->set_child[di->set_child[s]]] | |
472 | >= 2 * di->set_size[di->set_child[s]]) | |
473 | { | |
474 | di->set_chain[di->set_child[s]] = s; | |
475 | di->set_child[s] = di->set_child[di->set_child[s]]; | |
476 | } | |
477 | else | |
478 | { | |
479 | di->set_size[di->set_child[s]] = di->set_size[s]; | |
480 | s = di->set_chain[s] = di->set_child[s]; | |
481 | } | |
482 | } | |
483 | ||
484 | di->path_min[s] = di->path_min[w]; | |
485 | di->set_size[v] += di->set_size[w]; | |
486 | if (di->set_size[v] < 2 * di->set_size[w]) | |
6b4db501 | 487 | std::swap (di->set_child[v], s); |
f8032688 MM |
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) |
f3c676e1 TV |
649 | { |
650 | #if ENABLE_CHECKING | |
4081bdd2 | 651 | verify_dominators (dir); |
f3c676e1 TV |
652 | #endif |
653 | return; | |
654 | } | |
355be0dc | 655 | |
74c96e0c | 656 | timevar_push (TV_DOMINANCE); |
fce22de5 | 657 | if (!dom_info_available_p (dir)) |
d47cc544 | 658 | { |
2b28c07a | 659 | gcc_assert (!n_bbs_in_dom_tree[dir_index]); |
f8032688 | 660 | |
04a90bec | 661 | FOR_ALL_BB_FN (b, cfun) |
d47cc544 | 662 | { |
2b28c07a | 663 | b->dom[dir_index] = et_new_tree (b); |
d47cc544 | 664 | } |
0cae8d31 | 665 | n_bbs_in_dom_tree[dir_index] = n_basic_blocks_for_fn (cfun); |
f8032688 | 666 | |
26e0e410 | 667 | init_dom_info (&di, dir); |
2b28c07a JC |
668 | calc_dfs_tree (&di, reverse); |
669 | calc_idoms (&di, reverse); | |
355be0dc | 670 | |
11cd3bed | 671 | FOR_EACH_BB_FN (b, cfun) |
d47cc544 SB |
672 | { |
673 | TBB d = di.dom[di.dfs_order[b->index]]; | |
674 | ||
675 | if (di.dfs_to_bb[d]) | |
2b28c07a | 676 | et_set_father (b->dom[dir_index], di.dfs_to_bb[d]->dom[dir_index]); |
d47cc544 | 677 | } |
e0082a72 | 678 | |
d47cc544 | 679 | free_dom_info (&di); |
2b28c07a | 680 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; |
355be0dc | 681 | } |
4081bdd2 TV |
682 | else |
683 | { | |
684 | #if ENABLE_CHECKING | |
685 | verify_dominators (dir); | |
686 | #endif | |
687 | } | |
355be0dc | 688 | |
d47cc544 | 689 | compute_dom_fast_query (dir); |
74c96e0c ZD |
690 | |
691 | timevar_pop (TV_DOMINANCE); | |
355be0dc JH |
692 | } |
693 | ||
d47cc544 | 694 | /* Free dominance information for direction DIR. */ |
355be0dc | 695 | void |
e3f613cb | 696 | free_dominance_info (function *fn, enum cdi_direction dir) |
355be0dc JH |
697 | { |
698 | basic_block bb; | |
2b28c07a | 699 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
355be0dc | 700 | |
e3f613cb | 701 | if (!dom_info_available_p (fn, dir)) |
d47cc544 SB |
702 | return; |
703 | ||
e3f613cb | 704 | FOR_ALL_BB_FN (bb, fn) |
d47cc544 | 705 | { |
2b28c07a JC |
706 | et_free_tree_force (bb->dom[dir_index]); |
707 | bb->dom[dir_index] = NULL; | |
d47cc544 | 708 | } |
5a6ccafd | 709 | et_free_pools (); |
d47cc544 | 710 | |
e3f613cb RB |
711 | fn->cfg->x_n_bbs_in_dom_tree[dir_index] = 0; |
712 | ||
713 | fn->cfg->x_dom_computed[dir_index] = DOM_NONE; | |
714 | } | |
6de9cd9a | 715 | |
e3f613cb RB |
716 | void |
717 | free_dominance_info (enum cdi_direction dir) | |
718 | { | |
719 | free_dominance_info (cfun, dir); | |
355be0dc JH |
720 | } |
721 | ||
722 | /* Return the immediate dominator of basic block BB. */ | |
723 | basic_block | |
d47cc544 | 724 | get_immediate_dominator (enum cdi_direction dir, basic_block bb) |
355be0dc | 725 | { |
2b28c07a JC |
726 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
727 | struct et_node *node = bb->dom[dir_index]; | |
d47cc544 | 728 | |
2ba31c05 | 729 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 SB |
730 | |
731 | if (!node->father) | |
732 | return NULL; | |
733 | ||
f883e0a7 | 734 | return (basic_block) node->father->data; |
355be0dc JH |
735 | } |
736 | ||
737 | /* Set the immediate dominator of the block possibly removing | |
738 | existing edge. NULL can be used to remove any edge. */ | |
7031a8b9 | 739 | void |
d47cc544 SB |
740 | set_immediate_dominator (enum cdi_direction dir, basic_block bb, |
741 | basic_block dominated_by) | |
355be0dc | 742 | { |
2b28c07a JC |
743 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
744 | struct et_node *node = bb->dom[dir_index]; | |
b8698a0f | 745 | |
2ba31c05 | 746 | gcc_checking_assert (dom_computed[dir_index]); |
355be0dc | 747 | |
d47cc544 | 748 | if (node->father) |
355be0dc | 749 | { |
d47cc544 | 750 | if (node->father->data == dominated_by) |
6de9cd9a | 751 | return; |
d47cc544 | 752 | et_split (node); |
355be0dc | 753 | } |
d47cc544 SB |
754 | |
755 | if (dominated_by) | |
2b28c07a | 756 | et_set_father (node, dominated_by->dom[dir_index]); |
d47cc544 | 757 | |
2b28c07a JC |
758 | if (dom_computed[dir_index] == DOM_OK) |
759 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
355be0dc JH |
760 | } |
761 | ||
66f97d31 ZD |
762 | /* Returns the list of basic blocks immediately dominated by BB, in the |
763 | direction DIR. */ | |
9771b263 | 764 | vec<basic_block> |
66f97d31 | 765 | get_dominated_by (enum cdi_direction dir, basic_block bb) |
355be0dc | 766 | { |
66f97d31 | 767 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
2b28c07a | 768 | struct et_node *node = bb->dom[dir_index], *son = node->son, *ason; |
6e1aa848 | 769 | vec<basic_block> bbs = vNULL; |
66f97d31 | 770 | |
2ba31c05 | 771 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 SB |
772 | |
773 | if (!son) | |
6e1aa848 | 774 | return vNULL; |
d47cc544 | 775 | |
9771b263 | 776 | bbs.safe_push ((basic_block) son->data); |
2d888286 | 777 | for (ason = son->right; ason != son; ason = ason->right) |
9771b263 | 778 | bbs.safe_push ((basic_block) ason->data); |
355be0dc | 779 | |
66f97d31 | 780 | return bbs; |
355be0dc JH |
781 | } |
782 | ||
66f97d31 ZD |
783 | /* Returns the list of basic blocks that are immediately dominated (in |
784 | direction DIR) by some block between N_REGION ones stored in REGION, | |
785 | except for blocks in the REGION itself. */ | |
b8698a0f | 786 | |
9771b263 | 787 | vec<basic_block> |
42759f1e | 788 | get_dominated_by_region (enum cdi_direction dir, basic_block *region, |
66f97d31 | 789 | unsigned n_region) |
42759f1e | 790 | { |
66f97d31 | 791 | unsigned i; |
42759f1e | 792 | basic_block dom; |
6e1aa848 | 793 | vec<basic_block> doms = vNULL; |
42759f1e ZD |
794 | |
795 | for (i = 0; i < n_region; i++) | |
6580ee77 | 796 | region[i]->flags |= BB_DUPLICATED; |
42759f1e ZD |
797 | for (i = 0; i < n_region; i++) |
798 | for (dom = first_dom_son (dir, region[i]); | |
799 | dom; | |
800 | dom = next_dom_son (dir, dom)) | |
6580ee77 | 801 | if (!(dom->flags & BB_DUPLICATED)) |
9771b263 | 802 | doms.safe_push (dom); |
42759f1e | 803 | for (i = 0; i < n_region; i++) |
6580ee77 | 804 | region[i]->flags &= ~BB_DUPLICATED; |
42759f1e | 805 | |
66f97d31 | 806 | return doms; |
42759f1e ZD |
807 | } |
808 | ||
438c239d | 809 | /* Returns the list of basic blocks including BB dominated by BB, in the |
cad9aa15 MK |
810 | direction DIR up to DEPTH in the dominator tree. The DEPTH of zero will |
811 | produce a vector containing all dominated blocks. The vector will be sorted | |
812 | in preorder. */ | |
438c239d | 813 | |
9771b263 | 814 | vec<basic_block> |
cad9aa15 | 815 | get_dominated_to_depth (enum cdi_direction dir, basic_block bb, int depth) |
438c239d | 816 | { |
6e1aa848 | 817 | vec<basic_block> bbs = vNULL; |
438c239d | 818 | unsigned i; |
cad9aa15 | 819 | unsigned next_level_start; |
438c239d RG |
820 | |
821 | i = 0; | |
9771b263 DN |
822 | bbs.safe_push (bb); |
823 | next_level_start = 1; /* = bbs.length (); */ | |
438c239d RG |
824 | |
825 | do | |
826 | { | |
827 | basic_block son; | |
828 | ||
9771b263 | 829 | bb = bbs[i++]; |
438c239d RG |
830 | for (son = first_dom_son (dir, bb); |
831 | son; | |
832 | son = next_dom_son (dir, son)) | |
9771b263 | 833 | bbs.safe_push (son); |
cad9aa15 MK |
834 | |
835 | if (i == next_level_start && --depth) | |
9771b263 | 836 | next_level_start = bbs.length (); |
438c239d | 837 | } |
cad9aa15 | 838 | while (i < next_level_start); |
438c239d RG |
839 | |
840 | return bbs; | |
841 | } | |
842 | ||
cad9aa15 MK |
843 | /* Returns the list of basic blocks including BB dominated by BB, in the |
844 | direction DIR. The vector will be sorted in preorder. */ | |
845 | ||
9771b263 | 846 | vec<basic_block> |
cad9aa15 MK |
847 | get_all_dominated_blocks (enum cdi_direction dir, basic_block bb) |
848 | { | |
849 | return get_dominated_to_depth (dir, bb, 0); | |
850 | } | |
851 | ||
355be0dc JH |
852 | /* Redirect all edges pointing to BB to TO. */ |
853 | void | |
d47cc544 SB |
854 | redirect_immediate_dominators (enum cdi_direction dir, basic_block bb, |
855 | basic_block to) | |
355be0dc | 856 | { |
2b28c07a JC |
857 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
858 | struct et_node *bb_node, *to_node, *son; | |
b8698a0f | 859 | |
2b28c07a JC |
860 | bb_node = bb->dom[dir_index]; |
861 | to_node = to->dom[dir_index]; | |
d47cc544 | 862 | |
2ba31c05 | 863 | gcc_checking_assert (dom_computed[dir_index]); |
355be0dc | 864 | |
d47cc544 SB |
865 | if (!bb_node->son) |
866 | return; | |
867 | ||
868 | while (bb_node->son) | |
355be0dc | 869 | { |
d47cc544 SB |
870 | son = bb_node->son; |
871 | ||
872 | et_split (son); | |
873 | et_set_father (son, to_node); | |
355be0dc | 874 | } |
d47cc544 | 875 | |
2b28c07a JC |
876 | if (dom_computed[dir_index] == DOM_OK) |
877 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
355be0dc JH |
878 | } |
879 | ||
880 | /* Find first basic block in the tree dominating both BB1 and BB2. */ | |
881 | basic_block | |
d47cc544 | 882 | nearest_common_dominator (enum cdi_direction dir, basic_block bb1, basic_block bb2) |
355be0dc | 883 | { |
2b28c07a JC |
884 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
885 | ||
2ba31c05 | 886 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 887 | |
355be0dc JH |
888 | if (!bb1) |
889 | return bb2; | |
890 | if (!bb2) | |
891 | return bb1; | |
d47cc544 | 892 | |
f883e0a7 | 893 | return (basic_block) et_nca (bb1->dom[dir_index], bb2->dom[dir_index])->data; |
355be0dc JH |
894 | } |
895 | ||
0bca51f0 DN |
896 | |
897 | /* Find the nearest common dominator for the basic blocks in BLOCKS, | |
898 | using dominance direction DIR. */ | |
899 | ||
900 | basic_block | |
901 | nearest_common_dominator_for_set (enum cdi_direction dir, bitmap blocks) | |
902 | { | |
903 | unsigned i, first; | |
904 | bitmap_iterator bi; | |
905 | basic_block dom; | |
b8698a0f | 906 | |
0bca51f0 | 907 | first = bitmap_first_set_bit (blocks); |
06e28de2 | 908 | dom = BASIC_BLOCK_FOR_FN (cfun, first); |
0bca51f0 | 909 | EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi) |
06e28de2 DM |
910 | if (dom != BASIC_BLOCK_FOR_FN (cfun, i)) |
911 | dom = nearest_common_dominator (dir, dom, BASIC_BLOCK_FOR_FN (cfun, i)); | |
0bca51f0 DN |
912 | |
913 | return dom; | |
914 | } | |
915 | ||
b629276a DB |
916 | /* Given a dominator tree, we can determine whether one thing |
917 | dominates another in constant time by using two DFS numbers: | |
918 | ||
919 | 1. The number for when we visit a node on the way down the tree | |
920 | 2. The number for when we visit a node on the way back up the tree | |
921 | ||
922 | You can view these as bounds for the range of dfs numbers the | |
923 | nodes in the subtree of the dominator tree rooted at that node | |
924 | will contain. | |
b8698a0f | 925 | |
b629276a DB |
926 | The dominator tree is always a simple acyclic tree, so there are |
927 | only three possible relations two nodes in the dominator tree have | |
928 | to each other: | |
b8698a0f | 929 | |
b629276a DB |
930 | 1. Node A is above Node B (and thus, Node A dominates node B) |
931 | ||
932 | A | |
933 | | | |
934 | C | |
935 | / \ | |
936 | B D | |
937 | ||
938 | ||
939 | In the above case, DFS_Number_In of A will be <= DFS_Number_In of | |
940 | B, and DFS_Number_Out of A will be >= DFS_Number_Out of B. This is | |
941 | because we must hit A in the dominator tree *before* B on the walk | |
942 | down, and we will hit A *after* B on the walk back up | |
b8698a0f | 943 | |
d8701f02 | 944 | 2. Node A is below node B (and thus, node B dominates node A) |
b8698a0f L |
945 | |
946 | ||
b629276a DB |
947 | B |
948 | | | |
949 | A | |
950 | / \ | |
951 | C D | |
952 | ||
953 | In the above case, DFS_Number_In of A will be >= DFS_Number_In of | |
954 | B, and DFS_Number_Out of A will be <= DFS_Number_Out of B. | |
b8698a0f | 955 | |
b629276a DB |
956 | This is because we must hit A in the dominator tree *after* B on |
957 | the walk down, and we will hit A *before* B on the walk back up | |
b8698a0f | 958 | |
b629276a DB |
959 | 3. Node A and B are siblings (and thus, neither dominates the other) |
960 | ||
961 | C | |
962 | | | |
963 | D | |
964 | / \ | |
965 | A B | |
966 | ||
967 | In the above case, DFS_Number_In of A will *always* be <= | |
968 | DFS_Number_In of B, and DFS_Number_Out of A will *always* be <= | |
969 | DFS_Number_Out of B. This is because we will always finish the dfs | |
970 | walk of one of the subtrees before the other, and thus, the dfs | |
971 | numbers for one subtree can't intersect with the range of dfs | |
972 | numbers for the other subtree. If you swap A and B's position in | |
973 | the dominator tree, the comparison changes direction, but the point | |
974 | is that both comparisons will always go the same way if there is no | |
975 | dominance relationship. | |
976 | ||
977 | Thus, it is sufficient to write | |
978 | ||
979 | A_Dominates_B (node A, node B) | |
980 | { | |
b8698a0f | 981 | return DFS_Number_In(A) <= DFS_Number_In(B) |
b629276a DB |
982 | && DFS_Number_Out (A) >= DFS_Number_Out(B); |
983 | } | |
984 | ||
985 | A_Dominated_by_B (node A, node B) | |
986 | { | |
048f1a9c | 987 | return DFS_Number_In(A) >= DFS_Number_In(B) |
b629276a DB |
988 | && DFS_Number_Out (A) <= DFS_Number_Out(B); |
989 | } */ | |
0bca51f0 | 990 | |
355be0dc JH |
991 | /* Return TRUE in case BB1 is dominated by BB2. */ |
992 | bool | |
ed7a4b4b | 993 | dominated_by_p (enum cdi_direction dir, const_basic_block bb1, const_basic_block bb2) |
b8698a0f | 994 | { |
2b28c07a JC |
995 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
996 | struct et_node *n1 = bb1->dom[dir_index], *n2 = bb2->dom[dir_index]; | |
b8698a0f | 997 | |
2ba31c05 | 998 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 999 | |
2b28c07a | 1000 | if (dom_computed[dir_index] == DOM_OK) |
d47cc544 | 1001 | return (n1->dfs_num_in >= n2->dfs_num_in |
6de9cd9a | 1002 | && n1->dfs_num_out <= n2->dfs_num_out); |
d47cc544 SB |
1003 | |
1004 | return et_below (n1, n2); | |
355be0dc JH |
1005 | } |
1006 | ||
f074ff6c ZD |
1007 | /* Returns the entry dfs number for basic block BB, in the direction DIR. */ |
1008 | ||
1009 | unsigned | |
1010 | bb_dom_dfs_in (enum cdi_direction dir, basic_block bb) | |
1011 | { | |
2b28c07a JC |
1012 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1013 | struct et_node *n = bb->dom[dir_index]; | |
f074ff6c | 1014 | |
2ba31c05 | 1015 | gcc_checking_assert (dom_computed[dir_index] == DOM_OK); |
f074ff6c ZD |
1016 | return n->dfs_num_in; |
1017 | } | |
1018 | ||
1019 | /* Returns the exit dfs number for basic block BB, in the direction DIR. */ | |
1020 | ||
1021 | unsigned | |
1022 | bb_dom_dfs_out (enum cdi_direction dir, basic_block bb) | |
1023 | { | |
2b28c07a JC |
1024 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1025 | struct et_node *n = bb->dom[dir_index]; | |
f074ff6c | 1026 | |
2ba31c05 | 1027 | gcc_checking_assert (dom_computed[dir_index] == DOM_OK); |
f074ff6c ZD |
1028 | return n->dfs_num_out; |
1029 | } | |
1030 | ||
355be0dc | 1031 | /* Verify invariants of dominator structure. */ |
24e47c76 | 1032 | DEBUG_FUNCTION void |
d47cc544 | 1033 | verify_dominators (enum cdi_direction dir) |
355be0dc JH |
1034 | { |
1035 | int err = 0; | |
1fc3998d ZD |
1036 | basic_block bb, imm_bb, imm_bb_correct; |
1037 | struct dom_info di; | |
1038 | bool reverse = (dir == CDI_POST_DOMINATORS) ? true : false; | |
355be0dc | 1039 | |
fce22de5 | 1040 | gcc_assert (dom_info_available_p (dir)); |
d47cc544 | 1041 | |
1fc3998d ZD |
1042 | init_dom_info (&di, dir); |
1043 | calc_dfs_tree (&di, reverse); | |
1044 | calc_idoms (&di, reverse); | |
1045 | ||
11cd3bed | 1046 | FOR_EACH_BB_FN (bb, cfun) |
355be0dc | 1047 | { |
1fc3998d ZD |
1048 | imm_bb = get_immediate_dominator (dir, bb); |
1049 | if (!imm_bb) | |
f8032688 | 1050 | { |
66f97d31 | 1051 | error ("dominator of %d status unknown", bb->index); |
355be0dc JH |
1052 | err = 1; |
1053 | } | |
66f97d31 | 1054 | |
1fc3998d ZD |
1055 | imm_bb_correct = di.dfs_to_bb[di.dom[di.dfs_order[bb->index]]]; |
1056 | if (imm_bb != imm_bb_correct) | |
e7bd94cc | 1057 | { |
66f97d31 | 1058 | error ("dominator of %d should be %d, not %d", |
1fc3998d | 1059 | bb->index, imm_bb_correct->index, imm_bb->index); |
66f97d31 | 1060 | err = 1; |
e7bd94cc ZD |
1061 | } |
1062 | } | |
1063 | ||
1fc3998d | 1064 | free_dom_info (&di); |
ced3f397 | 1065 | gcc_assert (!err); |
355be0dc JH |
1066 | } |
1067 | ||
738ed977 ZD |
1068 | /* Determine immediate dominator (or postdominator, according to DIR) of BB, |
1069 | assuming that dominators of other blocks are correct. We also use it to | |
1070 | recompute the dominators in a restricted area, by iterating it until it | |
71cc389b | 1071 | reaches a fixed point. */ |
738ed977 | 1072 | |
355be0dc | 1073 | basic_block |
66f97d31 | 1074 | recompute_dominator (enum cdi_direction dir, basic_block bb) |
355be0dc | 1075 | { |
2b28c07a | 1076 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
738ed977 ZD |
1077 | basic_block dom_bb = NULL; |
1078 | edge e; | |
628f6a4e | 1079 | edge_iterator ei; |
355be0dc | 1080 | |
2ba31c05 | 1081 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 1082 | |
738ed977 ZD |
1083 | if (dir == CDI_DOMINATORS) |
1084 | { | |
628f6a4e | 1085 | FOR_EACH_EDGE (e, ei, bb->preds) |
738ed977 ZD |
1086 | { |
1087 | if (!dominated_by_p (dir, e->src, bb)) | |
1088 | dom_bb = nearest_common_dominator (dir, dom_bb, e->src); | |
1089 | } | |
1090 | } | |
1091 | else | |
1092 | { | |
628f6a4e | 1093 | FOR_EACH_EDGE (e, ei, bb->succs) |
738ed977 ZD |
1094 | { |
1095 | if (!dominated_by_p (dir, e->dest, bb)) | |
1096 | dom_bb = nearest_common_dominator (dir, dom_bb, e->dest); | |
1097 | } | |
1098 | } | |
f8032688 | 1099 | |
738ed977 | 1100 | return dom_bb; |
355be0dc JH |
1101 | } |
1102 | ||
66f97d31 ZD |
1103 | /* Use simple heuristics (see iterate_fix_dominators) to determine dominators |
1104 | of BBS. We assume that all the immediate dominators except for those of the | |
1105 | blocks in BBS are correct. If CONSERVATIVE is true, we also assume that the | |
1106 | currently recorded immediate dominators of blocks in BBS really dominate the | |
1107 | blocks. The basic blocks for that we determine the dominator are removed | |
1108 | from BBS. */ | |
1109 | ||
1110 | static void | |
9771b263 | 1111 | prune_bbs_to_update_dominators (vec<basic_block> bbs, |
66f97d31 ZD |
1112 | bool conservative) |
1113 | { | |
1114 | unsigned i; | |
1115 | bool single; | |
1116 | basic_block bb, dom = NULL; | |
1117 | edge_iterator ei; | |
1118 | edge e; | |
1119 | ||
9771b263 | 1120 | for (i = 0; bbs.iterate (i, &bb);) |
66f97d31 | 1121 | { |
fefa31b5 | 1122 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
66f97d31 ZD |
1123 | goto succeed; |
1124 | ||
1125 | if (single_pred_p (bb)) | |
1126 | { | |
1127 | set_immediate_dominator (CDI_DOMINATORS, bb, single_pred (bb)); | |
1128 | goto succeed; | |
1129 | } | |
1130 | ||
1131 | if (!conservative) | |
1132 | goto fail; | |
1133 | ||
1134 | single = true; | |
1135 | dom = NULL; | |
1136 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1137 | { | |
1138 | if (dominated_by_p (CDI_DOMINATORS, e->src, bb)) | |
1139 | continue; | |
1140 | ||
1141 | if (!dom) | |
1142 | dom = e->src; | |
1143 | else | |
1144 | { | |
1145 | single = false; | |
1146 | dom = nearest_common_dominator (CDI_DOMINATORS, dom, e->src); | |
1147 | } | |
1148 | } | |
1149 | ||
1150 | gcc_assert (dom != NULL); | |
1151 | if (single | |
1152 | || find_edge (dom, bb)) | |
1153 | { | |
1154 | set_immediate_dominator (CDI_DOMINATORS, bb, dom); | |
1155 | goto succeed; | |
1156 | } | |
1157 | ||
1158 | fail: | |
1159 | i++; | |
1160 | continue; | |
1161 | ||
1162 | succeed: | |
9771b263 | 1163 | bbs.unordered_remove (i); |
66f97d31 ZD |
1164 | } |
1165 | } | |
1166 | ||
1167 | /* Returns root of the dominance tree in the direction DIR that contains | |
1168 | BB. */ | |
1169 | ||
1170 | static basic_block | |
1171 | root_of_dom_tree (enum cdi_direction dir, basic_block bb) | |
1172 | { | |
f883e0a7 | 1173 | return (basic_block) et_root (bb->dom[dom_convert_dir_to_idx (dir)])->data; |
66f97d31 ZD |
1174 | } |
1175 | ||
1176 | /* See the comment in iterate_fix_dominators. Finds the immediate dominators | |
1177 | for the sons of Y, found using the SON and BROTHER arrays representing | |
1178 | the dominance tree of graph G. BBS maps the vertices of G to the basic | |
1179 | blocks. */ | |
1180 | ||
1181 | static void | |
9771b263 | 1182 | determine_dominators_for_sons (struct graph *g, vec<basic_block> bbs, |
66f97d31 ZD |
1183 | int y, int *son, int *brother) |
1184 | { | |
1185 | bitmap gprime; | |
1186 | int i, a, nc; | |
9771b263 | 1187 | vec<int> *sccs; |
66f97d31 ZD |
1188 | basic_block bb, dom, ybb; |
1189 | unsigned si; | |
1190 | edge e; | |
1191 | edge_iterator ei; | |
1192 | ||
1193 | if (son[y] == -1) | |
1194 | return; | |
9771b263 | 1195 | if (y == (int) bbs.length ()) |
fefa31b5 | 1196 | ybb = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
66f97d31 | 1197 | else |
9771b263 | 1198 | ybb = bbs[y]; |
66f97d31 ZD |
1199 | |
1200 | if (brother[son[y]] == -1) | |
1201 | { | |
1202 | /* Handle the common case Y has just one son specially. */ | |
9771b263 | 1203 | bb = bbs[son[y]]; |
66f97d31 ZD |
1204 | set_immediate_dominator (CDI_DOMINATORS, bb, |
1205 | recompute_dominator (CDI_DOMINATORS, bb)); | |
1206 | identify_vertices (g, y, son[y]); | |
1207 | return; | |
1208 | } | |
1209 | ||
1210 | gprime = BITMAP_ALLOC (NULL); | |
1211 | for (a = son[y]; a != -1; a = brother[a]) | |
1212 | bitmap_set_bit (gprime, a); | |
1213 | ||
1214 | nc = graphds_scc (g, gprime); | |
1215 | BITMAP_FREE (gprime); | |
1216 | ||
9771b263 DN |
1217 | /* ??? Needed to work around the pre-processor confusion with |
1218 | using a multi-argument template type as macro argument. */ | |
1219 | typedef vec<int> vec_int_heap; | |
1220 | sccs = XCNEWVEC (vec_int_heap, nc); | |
66f97d31 | 1221 | for (a = son[y]; a != -1; a = brother[a]) |
9771b263 | 1222 | sccs[g->vertices[a].component].safe_push (a); |
66f97d31 ZD |
1223 | |
1224 | for (i = nc - 1; i >= 0; i--) | |
1225 | { | |
1226 | dom = NULL; | |
9771b263 | 1227 | FOR_EACH_VEC_ELT (sccs[i], si, a) |
66f97d31 | 1228 | { |
9771b263 | 1229 | bb = bbs[a]; |
66f97d31 ZD |
1230 | FOR_EACH_EDGE (e, ei, bb->preds) |
1231 | { | |
1232 | if (root_of_dom_tree (CDI_DOMINATORS, e->src) != ybb) | |
1233 | continue; | |
1234 | ||
1235 | dom = nearest_common_dominator (CDI_DOMINATORS, dom, e->src); | |
1236 | } | |
1237 | } | |
1238 | ||
1239 | gcc_assert (dom != NULL); | |
9771b263 | 1240 | FOR_EACH_VEC_ELT (sccs[i], si, a) |
66f97d31 | 1241 | { |
9771b263 | 1242 | bb = bbs[a]; |
66f97d31 ZD |
1243 | set_immediate_dominator (CDI_DOMINATORS, bb, dom); |
1244 | } | |
1245 | } | |
1246 | ||
1247 | for (i = 0; i < nc; i++) | |
9771b263 | 1248 | sccs[i].release (); |
66f97d31 ZD |
1249 | free (sccs); |
1250 | ||
1251 | for (a = son[y]; a != -1; a = brother[a]) | |
1252 | identify_vertices (g, y, a); | |
1253 | } | |
1254 | ||
1255 | /* Recompute dominance information for basic blocks in the set BBS. The | |
1256 | function assumes that the immediate dominators of all the other blocks | |
1257 | in CFG are correct, and that there are no unreachable blocks. | |
1258 | ||
1259 | If CONSERVATIVE is true, we additionally assume that all the ancestors of | |
1260 | a block of BBS in the current dominance tree dominate it. */ | |
1261 | ||
355be0dc | 1262 | void |
9771b263 | 1263 | iterate_fix_dominators (enum cdi_direction dir, vec<basic_block> bbs, |
66f97d31 | 1264 | bool conservative) |
355be0dc | 1265 | { |
66f97d31 ZD |
1266 | unsigned i; |
1267 | basic_block bb, dom; | |
1268 | struct graph *g; | |
1269 | int n, y; | |
1270 | size_t dom_i; | |
1271 | edge e; | |
1272 | edge_iterator ei; | |
66f97d31 | 1273 | int *parent, *son, *brother; |
2b28c07a | 1274 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
355be0dc | 1275 | |
66f97d31 ZD |
1276 | /* We only support updating dominators. There are some problems with |
1277 | updating postdominators (need to add fake edges from infinite loops | |
1278 | and noreturn functions), and since we do not currently use | |
1279 | iterate_fix_dominators for postdominators, any attempt to handle these | |
1280 | problems would be unused, untested, and almost surely buggy. We keep | |
1281 | the DIR argument for consistency with the rest of the dominator analysis | |
1282 | interface. */ | |
2ba31c05 | 1283 | gcc_checking_assert (dir == CDI_DOMINATORS && dom_computed[dir_index]); |
d47cc544 | 1284 | |
66f97d31 ZD |
1285 | /* The algorithm we use takes inspiration from the following papers, although |
1286 | the details are quite different from any of them: | |
1287 | ||
1288 | [1] G. Ramalingam, T. Reps, An Incremental Algorithm for Maintaining the | |
1289 | Dominator Tree of a Reducible Flowgraph | |
1290 | [2] V. C. Sreedhar, G. R. Gao, Y.-F. Lee: Incremental computation of | |
1291 | dominator trees | |
1292 | [3] K. D. Cooper, T. J. Harvey and K. Kennedy: A Simple, Fast Dominance | |
1293 | Algorithm | |
1294 | ||
1295 | First, we use the following heuristics to decrease the size of the BBS | |
1296 | set: | |
1297 | a) if BB has a single predecessor, then its immediate dominator is this | |
1298 | predecessor | |
1299 | additionally, if CONSERVATIVE is true: | |
1300 | b) if all the predecessors of BB except for one (X) are dominated by BB, | |
1301 | then X is the immediate dominator of BB | |
1302 | c) if the nearest common ancestor of the predecessors of BB is X and | |
1303 | X -> BB is an edge in CFG, then X is the immediate dominator of BB | |
1304 | ||
1305 | Then, we need to establish the dominance relation among the basic blocks | |
1306 | in BBS. We split the dominance tree by removing the immediate dominator | |
0d52bcc1 | 1307 | edges from BBS, creating a forest F. We form a graph G whose vertices |
66f97d31 | 1308 | are BBS and ENTRY and X -> Y is an edge of G if there exists an edge |
0d52bcc1 | 1309 | X' -> Y in CFG such that X' belongs to the tree of the dominance forest |
66f97d31 ZD |
1310 | whose root is X. We then determine dominance tree of G. Note that |
1311 | for X, Y in BBS, X dominates Y in CFG if and only if X dominates Y in G. | |
1312 | In this step, we can use arbitrary algorithm to determine dominators. | |
1313 | We decided to prefer the algorithm [3] to the algorithm of | |
1314 | Lengauer and Tarjan, since the set BBS is usually small (rarely exceeding | |
1315 | 10 during gcc bootstrap), and [3] should perform better in this case. | |
1316 | ||
1317 | Finally, we need to determine the immediate dominators for the basic | |
1318 | blocks of BBS. If the immediate dominator of X in G is Y, then | |
1319 | the immediate dominator of X in CFG belongs to the tree of F rooted in | |
1320 | Y. We process the dominator tree T of G recursively, starting from leaves. | |
1321 | Suppose that X_1, X_2, ..., X_k are the sons of Y in T, and that the | |
1322 | subtrees of the dominance tree of CFG rooted in X_i are already correct. | |
1323 | Let G' be the subgraph of G induced by {X_1, X_2, ..., X_k}. We make | |
1324 | the following observations: | |
1325 | (i) the immediate dominator of all blocks in a strongly connected | |
1326 | component of G' is the same | |
1327 | (ii) if X has no predecessors in G', then the immediate dominator of X | |
1328 | is the nearest common ancestor of the predecessors of X in the | |
1329 | subtree of F rooted in Y | |
1330 | Therefore, it suffices to find the topological ordering of G', and | |
1331 | process the nodes X_i in this order using the rules (i) and (ii). | |
1332 | Then, we contract all the nodes X_i with Y in G, so that the further | |
1333 | steps work correctly. */ | |
1334 | ||
1335 | if (!conservative) | |
1336 | { | |
1337 | /* Split the tree now. If the idoms of blocks in BBS are not | |
1338 | conservatively correct, setting the dominators using the | |
1339 | heuristics in prune_bbs_to_update_dominators could | |
1340 | create cycles in the dominance "tree", and cause ICE. */ | |
9771b263 | 1341 | FOR_EACH_VEC_ELT (bbs, i, bb) |
66f97d31 ZD |
1342 | set_immediate_dominator (CDI_DOMINATORS, bb, NULL); |
1343 | } | |
1344 | ||
1345 | prune_bbs_to_update_dominators (bbs, conservative); | |
9771b263 | 1346 | n = bbs.length (); |
66f97d31 ZD |
1347 | |
1348 | if (n == 0) | |
1349 | return; | |
e7bd94cc | 1350 | |
66f97d31 | 1351 | if (n == 1) |
355be0dc | 1352 | { |
9771b263 | 1353 | bb = bbs[0]; |
66f97d31 ZD |
1354 | set_immediate_dominator (CDI_DOMINATORS, bb, |
1355 | recompute_dominator (CDI_DOMINATORS, bb)); | |
1356 | return; | |
1357 | } | |
1358 | ||
1359 | /* Construct the graph G. */ | |
1eb68d2d | 1360 | hash_map<basic_block, int> map (251); |
9771b263 | 1361 | FOR_EACH_VEC_ELT (bbs, i, bb) |
66f97d31 ZD |
1362 | { |
1363 | /* If the dominance tree is conservatively correct, split it now. */ | |
1364 | if (conservative) | |
1365 | set_immediate_dominator (CDI_DOMINATORS, bb, NULL); | |
1eb68d2d | 1366 | map.put (bb, i); |
66f97d31 | 1367 | } |
1eb68d2d | 1368 | map.put (ENTRY_BLOCK_PTR_FOR_FN (cfun), n); |
66f97d31 ZD |
1369 | |
1370 | g = new_graph (n + 1); | |
1371 | for (y = 0; y < g->n_vertices; y++) | |
1372 | g->vertices[y].data = BITMAP_ALLOC (NULL); | |
9771b263 | 1373 | FOR_EACH_VEC_ELT (bbs, i, bb) |
66f97d31 ZD |
1374 | { |
1375 | FOR_EACH_EDGE (e, ei, bb->preds) | |
355be0dc | 1376 | { |
66f97d31 ZD |
1377 | dom = root_of_dom_tree (CDI_DOMINATORS, e->src); |
1378 | if (dom == bb) | |
1379 | continue; | |
1380 | ||
1eb68d2d | 1381 | dom_i = *map.get (dom); |
66f97d31 ZD |
1382 | |
1383 | /* Do not include parallel edges to G. */ | |
fcaa4ca4 | 1384 | if (!bitmap_set_bit ((bitmap) g->vertices[dom_i].data, i)) |
66f97d31 ZD |
1385 | continue; |
1386 | ||
66f97d31 | 1387 | add_edge (g, dom_i, i); |
f8032688 MM |
1388 | } |
1389 | } | |
66f97d31 ZD |
1390 | for (y = 0; y < g->n_vertices; y++) |
1391 | BITMAP_FREE (g->vertices[y].data); | |
66f97d31 ZD |
1392 | |
1393 | /* Find the dominator tree of G. */ | |
1394 | son = XNEWVEC (int, n + 1); | |
1395 | brother = XNEWVEC (int, n + 1); | |
1396 | parent = XNEWVEC (int, n + 1); | |
1397 | graphds_domtree (g, n, parent, son, brother); | |
1398 | ||
1399 | /* Finally, traverse the tree and find the immediate dominators. */ | |
1400 | for (y = n; son[y] != -1; y = son[y]) | |
1401 | continue; | |
1402 | while (y != -1) | |
1403 | { | |
1404 | determine_dominators_for_sons (g, bbs, y, son, brother); | |
1405 | ||
1406 | if (brother[y] != -1) | |
1407 | { | |
1408 | y = brother[y]; | |
1409 | while (son[y] != -1) | |
1410 | y = son[y]; | |
1411 | } | |
1412 | else | |
1413 | y = parent[y]; | |
1414 | } | |
1415 | ||
1416 | free (son); | |
1417 | free (brother); | |
1418 | free (parent); | |
e7bd94cc | 1419 | |
66f97d31 | 1420 | free_graph (g); |
355be0dc | 1421 | } |
f8032688 | 1422 | |
355be0dc | 1423 | void |
d47cc544 | 1424 | add_to_dominance_info (enum cdi_direction dir, basic_block bb) |
355be0dc | 1425 | { |
2b28c07a JC |
1426 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1427 | ||
2ba31c05 | 1428 | gcc_checking_assert (dom_computed[dir_index] && !bb->dom[dir_index]); |
d47cc544 | 1429 | |
2b28c07a | 1430 | n_bbs_in_dom_tree[dir_index]++; |
b8698a0f | 1431 | |
2b28c07a | 1432 | bb->dom[dir_index] = et_new_tree (bb); |
d47cc544 | 1433 | |
2b28c07a JC |
1434 | if (dom_computed[dir_index] == DOM_OK) |
1435 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
355be0dc JH |
1436 | } |
1437 | ||
1438 | void | |
d47cc544 SB |
1439 | delete_from_dominance_info (enum cdi_direction dir, basic_block bb) |
1440 | { | |
2b28c07a | 1441 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
d47cc544 | 1442 | |
2ba31c05 | 1443 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 1444 | |
2b28c07a JC |
1445 | et_free_tree (bb->dom[dir_index]); |
1446 | bb->dom[dir_index] = NULL; | |
1447 | n_bbs_in_dom_tree[dir_index]--; | |
1448 | ||
1449 | if (dom_computed[dir_index] == DOM_OK) | |
1450 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
d47cc544 SB |
1451 | } |
1452 | ||
1453 | /* Returns the first son of BB in the dominator or postdominator tree | |
1454 | as determined by DIR. */ | |
1455 | ||
1456 | basic_block | |
1457 | first_dom_son (enum cdi_direction dir, basic_block bb) | |
355be0dc | 1458 | { |
2b28c07a JC |
1459 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1460 | struct et_node *son = bb->dom[dir_index]->son; | |
d47cc544 | 1461 | |
f883e0a7 | 1462 | return (basic_block) (son ? son->data : NULL); |
d47cc544 SB |
1463 | } |
1464 | ||
1465 | /* Returns the next dominance son after BB in the dominator or postdominator | |
1466 | tree as determined by DIR, or NULL if it was the last one. */ | |
1467 | ||
1468 | basic_block | |
1469 | next_dom_son (enum cdi_direction dir, basic_block bb) | |
1470 | { | |
2b28c07a JC |
1471 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1472 | struct et_node *next = bb->dom[dir_index]->right; | |
d47cc544 | 1473 | |
f883e0a7 | 1474 | return (basic_block) (next->father->son == next ? NULL : next->data); |
355be0dc JH |
1475 | } |
1476 | ||
2b28c07a JC |
1477 | /* Return dominance availability for dominance info DIR. */ |
1478 | ||
1479 | enum dom_state | |
e3f613cb | 1480 | dom_info_state (function *fn, enum cdi_direction dir) |
2b28c07a | 1481 | { |
e3f613cb RB |
1482 | if (!fn->cfg) |
1483 | return DOM_NONE; | |
1484 | ||
2b28c07a | 1485 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
e3f613cb RB |
1486 | return fn->cfg->x_dom_computed[dir_index]; |
1487 | } | |
2b28c07a | 1488 | |
e3f613cb RB |
1489 | enum dom_state |
1490 | dom_info_state (enum cdi_direction dir) | |
1491 | { | |
1492 | return dom_info_state (cfun, dir); | |
2b28c07a JC |
1493 | } |
1494 | ||
1495 | /* Set the dominance availability for dominance info DIR to NEW_STATE. */ | |
1496 | ||
1497 | void | |
1498 | set_dom_info_availability (enum cdi_direction dir, enum dom_state new_state) | |
1499 | { | |
1500 | unsigned int dir_index = dom_convert_dir_to_idx (dir); | |
1501 | ||
1502 | dom_computed[dir_index] = new_state; | |
1503 | } | |
1504 | ||
fce22de5 ZD |
1505 | /* Returns true if dominance information for direction DIR is available. */ |
1506 | ||
1507 | bool | |
e3f613cb | 1508 | dom_info_available_p (function *fn, enum cdi_direction dir) |
fce22de5 | 1509 | { |
e3f613cb RB |
1510 | return dom_info_state (fn, dir) != DOM_NONE; |
1511 | } | |
2b28c07a | 1512 | |
e3f613cb RB |
1513 | bool |
1514 | dom_info_available_p (enum cdi_direction dir) | |
1515 | { | |
1516 | return dom_info_available_p (cfun, dir); | |
fce22de5 ZD |
1517 | } |
1518 | ||
24e47c76 | 1519 | DEBUG_FUNCTION void |
d47cc544 | 1520 | debug_dominance_info (enum cdi_direction dir) |
355be0dc JH |
1521 | { |
1522 | basic_block bb, bb2; | |
11cd3bed | 1523 | FOR_EACH_BB_FN (bb, cfun) |
d47cc544 | 1524 | if ((bb2 = get_immediate_dominator (dir, bb))) |
355be0dc | 1525 | fprintf (stderr, "%i %i\n", bb->index, bb2->index); |
f8032688 | 1526 | } |
1fc3998d ZD |
1527 | |
1528 | /* Prints to stderr representation of the dominance tree (for direction DIR) | |
cea618ac | 1529 | rooted in ROOT, indented by INDENT tabulators. If INDENT_FIRST is false, |
1fc3998d ZD |
1530 | the first line of the output is not indented. */ |
1531 | ||
1532 | static void | |
1533 | debug_dominance_tree_1 (enum cdi_direction dir, basic_block root, | |
1534 | unsigned indent, bool indent_first) | |
1535 | { | |
1536 | basic_block son; | |
1537 | unsigned i; | |
1538 | bool first = true; | |
1539 | ||
1540 | if (indent_first) | |
1541 | for (i = 0; i < indent; i++) | |
1542 | fprintf (stderr, "\t"); | |
1543 | fprintf (stderr, "%d\t", root->index); | |
1544 | ||
1545 | for (son = first_dom_son (dir, root); | |
1546 | son; | |
1547 | son = next_dom_son (dir, son)) | |
1548 | { | |
1549 | debug_dominance_tree_1 (dir, son, indent + 1, !first); | |
1550 | first = false; | |
1551 | } | |
1552 | ||
1553 | if (first) | |
1554 | fprintf (stderr, "\n"); | |
1555 | } | |
1556 | ||
1557 | /* Prints to stderr representation of the dominance tree (for direction DIR) | |
1558 | rooted in ROOT. */ | |
1559 | ||
24e47c76 | 1560 | DEBUG_FUNCTION void |
1fc3998d ZD |
1561 | debug_dominance_tree (enum cdi_direction dir, basic_block root) |
1562 | { | |
1563 | debug_dominance_tree_1 (dir, root, 0, false); | |
1564 | } |