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f8032688 | 1 | /* Calculate (post)dominators in slightly super-linear time. |
818ab71a | 2 | Copyright (C) 2000-2016 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 | 37 | #include "coretypes.h" |
c7131fb2 | 38 | #include "backend.h" |
74c96e0c | 39 | #include "timevar.h" |
957060b5 AM |
40 | #include "diagnostic-core.h" |
41 | #include "cfganal.h" | |
42 | #include "et-forest.h" | |
66f97d31 | 43 | #include "graphds.h" |
f8032688 | 44 | |
f8032688 MM |
45 | /* We name our nodes with integers, beginning with 1. Zero is reserved for |
46 | 'undefined' or 'end of list'. The name of each node is given by the dfs | |
47 | number of the corresponding basic block. Please note, that we include the | |
48 | artificial ENTRY_BLOCK (or EXIT_BLOCK in the post-dom case) in our lists to | |
24bd1a0b | 49 | support multiple entry points. Its dfs number is of course 1. */ |
f8032688 MM |
50 | |
51 | /* Type of Basic Block aka. TBB */ | |
52 | typedef unsigned int TBB; | |
53 | ||
2321dd91 | 54 | namespace { |
f8032688 | 55 | |
2321dd91 MM |
56 | /* This class holds various arrays reflecting the (sub)structure of the |
57 | flowgraph. Most of them are of type TBB and are also indexed by TBB. */ | |
58 | ||
59 | class dom_info | |
f8032688 | 60 | { |
2321dd91 MM |
61 | public: |
62 | dom_info (function *, cdi_direction); | |
63 | ~dom_info (); | |
64 | void calc_dfs_tree (); | |
65 | void calc_idoms (); | |
66 | ||
67 | inline basic_block get_idom (basic_block); | |
68 | private: | |
69 | void calc_dfs_tree_nonrec (basic_block); | |
70 | void compress (TBB); | |
71 | TBB eval (TBB); | |
72 | void link_roots (TBB, TBB); | |
73 | ||
f8032688 | 74 | /* The parent of a node in the DFS tree. */ |
2321dd91 MM |
75 | TBB *m_dfs_parent; |
76 | /* For a node x m_key[x] is roughly the node nearest to the root from which | |
f8032688 MM |
77 | exists a way to x only over nodes behind x. Such a node is also called |
78 | semidominator. */ | |
2321dd91 MM |
79 | TBB *m_key; |
80 | /* The value in m_path_min[x] is the node y on the path from x to the root of | |
81 | the tree x is in with the smallest m_key[y]. */ | |
82 | TBB *m_path_min; | |
83 | /* m_bucket[x] points to the first node of the set of nodes having x as | |
84 | key. */ | |
85 | TBB *m_bucket; | |
86 | /* And m_next_bucket[x] points to the next node. */ | |
87 | TBB *m_next_bucket; | |
88 | /* After the algorithm is done, m_dom[x] contains the immediate dominator | |
f8032688 | 89 | of x. */ |
2321dd91 | 90 | TBB *m_dom; |
f8032688 MM |
91 | |
92 | /* The following few fields implement the structures needed for disjoint | |
93 | sets. */ | |
2321dd91 MM |
94 | /* m_set_chain[x] is the next node on the path from x to the representative |
95 | of the set containing x. If m_set_chain[x]==0 then x is a root. */ | |
96 | TBB *m_set_chain; | |
97 | /* m_set_size[x] is the number of elements in the set named by x. */ | |
98 | unsigned int *m_set_size; | |
99 | /* m_set_child[x] is used for balancing the tree representing a set. It can | |
f8032688 | 100 | be understood as the next sibling of x. */ |
2321dd91 | 101 | TBB *m_set_child; |
f8032688 | 102 | |
2321dd91 | 103 | /* If b is the number of a basic block (BB->index), m_dfs_order[b] is the |
f8032688 MM |
104 | number of that node in DFS order counted from 1. This is an index |
105 | into most of the other arrays in this structure. */ | |
2321dd91 MM |
106 | TBB *m_dfs_order; |
107 | /* Points to last element in m_dfs_order array. */ | |
108 | TBB *m_dfs_last; | |
09da1532 | 109 | /* If x is the DFS-index of a node which corresponds with a basic block, |
2321dd91 MM |
110 | m_dfs_to_bb[x] is that basic block. Note, that in our structure there are |
111 | more nodes that basic blocks, so only | |
112 | m_dfs_to_bb[m_dfs_order[bb->index]]==bb is true for every basic block bb, | |
113 | but not the opposite. */ | |
114 | basic_block *m_dfs_to_bb; | |
f8032688 | 115 | |
26e0e410 | 116 | /* This is the next free DFS number when creating the DFS tree. */ |
2321dd91 MM |
117 | unsigned int m_dfsnum; |
118 | /* The number of nodes in the DFS tree (==m_dfsnum-1). */ | |
119 | unsigned int m_nodes; | |
26e0e410 RH |
120 | |
121 | /* Blocks with bits set here have a fake edge to EXIT. These are used | |
122 | to turn a DFS forest into a proper tree. */ | |
2321dd91 MM |
123 | bitmap m_fake_exit_edge; |
124 | ||
125 | /* Number of basic blocks in the function being compiled. */ | |
126 | size_t m_n_basic_blocks; | |
127 | ||
128 | /* True, if we are computing postdominators (rather than dominators). */ | |
129 | bool m_reverse; | |
130 | ||
131 | /* Start block (the entry block for forward problem, exit block for backward | |
132 | problem). */ | |
133 | basic_block m_start_block; | |
134 | /* Ending block. */ | |
135 | basic_block m_end_block; | |
f8032688 MM |
136 | }; |
137 | ||
2321dd91 | 138 | } // anonymous namespace |
f8032688 | 139 | |
2321dd91 MM |
140 | void debug_dominance_info (cdi_direction); |
141 | void debug_dominance_tree (cdi_direction, basic_block); | |
142 | ||
143 | /* Allocate and zero-initialize NUM elements of type T (T must be a | |
144 | POD-type). Note: after transition to C++11 or later, | |
145 | `x = new_zero_array <T> (num);' can be replaced with | |
146 | `x = new T[num] {};'. */ | |
147 | ||
148 | template<typename T> | |
149 | inline T *new_zero_array (size_t num) | |
150 | { | |
151 | T *result = new T[num]; | |
152 | memset (result, 0, sizeof (T) * num); | |
153 | return result; | |
154 | } | |
155 | ||
156 | /* Allocate all needed memory in a pessimistic fashion (so we round up). */ | |
157 | ||
158 | dom_info::dom_info (function *fn, cdi_direction dir) | |
f8032688 | 159 | { |
6fb5fa3c | 160 | /* We need memory for n_basic_blocks nodes. */ |
2321dd91 MM |
161 | size_t num = m_n_basic_blocks = n_basic_blocks_for_fn (fn); |
162 | m_dfs_parent = new_zero_array <TBB> (num); | |
163 | m_dom = new_zero_array <TBB> (num); | |
164 | ||
165 | m_path_min = new TBB[num]; | |
166 | m_key = new TBB[num]; | |
167 | m_set_size = new unsigned int[num]; | |
168 | for (size_t i = 0; i < num; i++) | |
169 | { | |
170 | m_path_min[i] = m_key[i] = i; | |
171 | m_set_size[i] = 1; | |
172 | } | |
f8032688 | 173 | |
2321dd91 MM |
174 | m_bucket = new_zero_array <TBB> (num); |
175 | m_next_bucket = new_zero_array <TBB> (num); | |
f8032688 | 176 | |
2321dd91 MM |
177 | m_set_chain = new_zero_array <TBB> (num); |
178 | m_set_child = new_zero_array <TBB> (num); | |
f8032688 | 179 | |
2321dd91 MM |
180 | unsigned last_bb_index = last_basic_block_for_fn (fn); |
181 | m_dfs_order = new_zero_array <TBB> (last_bb_index + 1); | |
182 | m_dfs_last = &m_dfs_order[last_bb_index]; | |
183 | m_dfs_to_bb = new_zero_array <basic_block> (num); | |
f8032688 | 184 | |
2321dd91 MM |
185 | m_dfsnum = 1; |
186 | m_nodes = 0; | |
26e0e410 | 187 | |
2b28c07a JC |
188 | switch (dir) |
189 | { | |
190 | case CDI_DOMINATORS: | |
2321dd91 MM |
191 | m_reverse = false; |
192 | m_fake_exit_edge = NULL; | |
193 | m_start_block = ENTRY_BLOCK_PTR_FOR_FN (fn); | |
194 | m_end_block = EXIT_BLOCK_PTR_FOR_FN (fn); | |
2b28c07a JC |
195 | break; |
196 | case CDI_POST_DOMINATORS: | |
2321dd91 MM |
197 | m_reverse = true; |
198 | m_fake_exit_edge = BITMAP_ALLOC (NULL); | |
199 | m_start_block = EXIT_BLOCK_PTR_FOR_FN (fn); | |
200 | m_end_block = ENTRY_BLOCK_PTR_FOR_FN (fn); | |
2b28c07a JC |
201 | break; |
202 | default: | |
203 | gcc_unreachable (); | |
2b28c07a | 204 | } |
f8032688 MM |
205 | } |
206 | ||
2321dd91 MM |
207 | inline basic_block |
208 | dom_info::get_idom (basic_block bb) | |
209 | { | |
210 | TBB d = m_dom[m_dfs_order[bb->index]]; | |
211 | return m_dfs_to_bb[d]; | |
212 | } | |
f8032688 | 213 | |
2b28c07a JC |
214 | /* Map dominance calculation type to array index used for various |
215 | dominance information arrays. This version is simple -- it will need | |
216 | to be modified, obviously, if additional values are added to | |
217 | cdi_direction. */ | |
218 | ||
2321dd91 MM |
219 | static inline unsigned int |
220 | dom_convert_dir_to_idx (cdi_direction dir) | |
2b28c07a | 221 | { |
2ba31c05 | 222 | gcc_checking_assert (dir == CDI_DOMINATORS || dir == CDI_POST_DOMINATORS); |
2b28c07a JC |
223 | return dir - 1; |
224 | } | |
225 | ||
2321dd91 | 226 | /* Free all allocated memory in dom_info. */ |
f8032688 | 227 | |
2321dd91 | 228 | dom_info::~dom_info () |
f8032688 | 229 | { |
2321dd91 MM |
230 | delete[] m_dfs_parent; |
231 | delete[] m_path_min; | |
232 | delete[] m_key; | |
233 | delete[] m_dom; | |
234 | delete[] m_bucket; | |
235 | delete[] m_next_bucket; | |
236 | delete[] m_set_chain; | |
237 | delete[] m_set_size; | |
238 | delete[] m_set_child; | |
239 | delete[] m_dfs_order; | |
240 | delete[] m_dfs_to_bb; | |
241 | BITMAP_FREE (m_fake_exit_edge); | |
f8032688 MM |
242 | } |
243 | ||
2321dd91 MM |
244 | /* The nonrecursive variant of creating a DFS tree. BB is the starting basic |
245 | block for this tree and m_reverse is true, if predecessors should be visited | |
246 | instead of successors of a node. After this is done all nodes reachable | |
247 | from BB were visited, have assigned their dfs number and are linked together | |
248 | to form a tree. */ | |
f8032688 | 249 | |
2321dd91 MM |
250 | void |
251 | dom_info::calc_dfs_tree_nonrec (basic_block bb) | |
f8032688 | 252 | { |
2321dd91 MM |
253 | edge_iterator *stack = new edge_iterator[m_n_basic_blocks + 1]; |
254 | int sp = 0; | |
f8032688 | 255 | |
2321dd91 MM |
256 | /* Initialize the first edge. */ |
257 | edge_iterator ei = m_reverse ? ei_start (bb->preds) | |
258 | : ei_start (bb->succs); | |
f8032688 MM |
259 | |
260 | /* When the stack is empty we break out of this loop. */ | |
261 | while (1) | |
262 | { | |
263 | basic_block bn; | |
2321dd91 | 264 | edge_iterator einext; |
f8032688 MM |
265 | |
266 | /* This loop traverses edges e in depth first manner, and fills the | |
267 | stack. */ | |
628f6a4e | 268 | while (!ei_end_p (ei)) |
f8032688 | 269 | { |
2321dd91 | 270 | edge e = ei_edge (ei); |
f8032688 MM |
271 | |
272 | /* Deduce from E the current and the next block (BB and BN), and the | |
273 | next edge. */ | |
2321dd91 | 274 | if (m_reverse) |
f8032688 MM |
275 | { |
276 | bn = e->src; | |
277 | ||
278 | /* If the next node BN is either already visited or a border | |
279 | block the current edge is useless, and simply overwritten | |
280 | with the next edge out of the current node. */ | |
2321dd91 | 281 | if (bn == m_end_block || m_dfs_order[bn->index]) |
f8032688 | 282 | { |
628f6a4e | 283 | ei_next (&ei); |
f8032688 MM |
284 | continue; |
285 | } | |
286 | bb = e->dest; | |
628f6a4e | 287 | einext = ei_start (bn->preds); |
f8032688 MM |
288 | } |
289 | else | |
290 | { | |
291 | bn = e->dest; | |
2321dd91 | 292 | if (bn == m_end_block || m_dfs_order[bn->index]) |
f8032688 | 293 | { |
628f6a4e | 294 | ei_next (&ei); |
f8032688 MM |
295 | continue; |
296 | } | |
297 | bb = e->src; | |
628f6a4e | 298 | einext = ei_start (bn->succs); |
f8032688 MM |
299 | } |
300 | ||
2321dd91 | 301 | gcc_assert (bn != m_start_block); |
f8032688 MM |
302 | |
303 | /* Fill the DFS tree info calculatable _before_ recursing. */ | |
2321dd91 MM |
304 | TBB my_i; |
305 | if (bb != m_start_block) | |
306 | my_i = m_dfs_order[bb->index]; | |
f8032688 | 307 | else |
2321dd91 MM |
308 | my_i = *m_dfs_last; |
309 | TBB child_i = m_dfs_order[bn->index] = m_dfsnum++; | |
310 | m_dfs_to_bb[child_i] = bn; | |
311 | m_dfs_parent[child_i] = my_i; | |
f8032688 MM |
312 | |
313 | /* Save the current point in the CFG on the stack, and recurse. */ | |
628f6a4e BE |
314 | stack[sp++] = ei; |
315 | ei = einext; | |
f8032688 MM |
316 | } |
317 | ||
318 | if (!sp) | |
319 | break; | |
628f6a4e | 320 | ei = stack[--sp]; |
f8032688 MM |
321 | |
322 | /* OK. The edge-list was exhausted, meaning normally we would | |
323 | end the recursion. After returning from the recursive call, | |
324 | there were (may be) other statements which were run after a | |
325 | child node was completely considered by DFS. Here is the | |
326 | point to do it in the non-recursive variant. | |
327 | E.g. The block just completed is in e->dest for forward DFS, | |
328 | the block not yet completed (the parent of the one above) | |
329 | in e->src. This could be used e.g. for computing the number of | |
330 | descendants or the tree depth. */ | |
628f6a4e | 331 | ei_next (&ei); |
f8032688 | 332 | } |
2321dd91 | 333 | delete[] stack; |
f8032688 MM |
334 | } |
335 | ||
2321dd91 MM |
336 | /* The main entry for calculating the DFS tree or forest. m_reverse is true, |
337 | if we are interested in the reverse flow graph. In that case the result is | |
338 | not necessarily a tree but a forest, because there may be nodes from which | |
339 | the EXIT_BLOCK is unreachable. */ | |
f8032688 | 340 | |
2321dd91 MM |
341 | void |
342 | dom_info::calc_dfs_tree () | |
f8032688 | 343 | { |
2321dd91 MM |
344 | *m_dfs_last = m_dfsnum; |
345 | m_dfs_to_bb[m_dfsnum] = m_start_block; | |
346 | m_dfsnum++; | |
f8032688 | 347 | |
2321dd91 | 348 | calc_dfs_tree_nonrec (m_start_block); |
f8032688 | 349 | |
2321dd91 | 350 | if (m_reverse) |
f8032688 MM |
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 | ||
2321dd91 | 365 | FOR_BB_BETWEEN (b, m_start_block->prev_bb, m_end_block, prev_bb) |
f8032688 | 366 | { |
628f6a4e | 367 | if (EDGE_COUNT (b->succs) > 0) |
26e0e410 | 368 | { |
2321dd91 | 369 | if (m_dfs_order[b->index] == 0) |
26e0e410 RH |
370 | saw_unconnected = true; |
371 | continue; | |
372 | } | |
2321dd91 MM |
373 | bitmap_set_bit (m_fake_exit_edge, b->index); |
374 | m_dfs_order[b->index] = m_dfsnum; | |
375 | m_dfs_to_bb[m_dfsnum] = b; | |
376 | m_dfs_parent[m_dfsnum] = *m_dfs_last; | |
377 | m_dfsnum++; | |
378 | calc_dfs_tree_nonrec (b); | |
f8032688 | 379 | } |
26e0e410 RH |
380 | |
381 | if (saw_unconnected) | |
382 | { | |
2321dd91 | 383 | FOR_BB_BETWEEN (b, m_start_block->prev_bb, m_end_block, prev_bb) |
26e0e410 | 384 | { |
2321dd91 | 385 | if (m_dfs_order[b->index]) |
26e0e410 | 386 | continue; |
2321dd91 MM |
387 | basic_block b2 = dfs_find_deadend (b); |
388 | gcc_checking_assert (m_dfs_order[b2->index] == 0); | |
389 | bitmap_set_bit (m_fake_exit_edge, b2->index); | |
390 | m_dfs_order[b2->index] = m_dfsnum; | |
391 | m_dfs_to_bb[m_dfsnum] = b2; | |
392 | m_dfs_parent[m_dfsnum] = *m_dfs_last; | |
393 | m_dfsnum++; | |
394 | calc_dfs_tree_nonrec (b2); | |
395 | gcc_checking_assert (m_dfs_order[b->index]); | |
26e0e410 RH |
396 | } |
397 | } | |
f8032688 MM |
398 | } |
399 | ||
2321dd91 | 400 | m_nodes = m_dfsnum - 1; |
f8032688 | 401 | |
24bd1a0b | 402 | /* This aborts e.g. when there is _no_ path from ENTRY to EXIT at all. */ |
2321dd91 | 403 | gcc_assert (m_nodes == (unsigned int) m_n_basic_blocks - 1); |
f8032688 MM |
404 | } |
405 | ||
406 | /* Compress the path from V to the root of its set and update path_min at the | |
407 | same time. After compress(di, V) set_chain[V] is the root of the set V is | |
408 | in and path_min[V] is the node with the smallest key[] value on the path | |
409 | from V to that root. */ | |
410 | ||
2321dd91 MM |
411 | void |
412 | dom_info::compress (TBB v) | |
f8032688 MM |
413 | { |
414 | /* Btw. It's not worth to unrecurse compress() as the depth is usually not | |
415 | greater than 5 even for huge graphs (I've not seen call depth > 4). | |
416 | Also performance wise compress() ranges _far_ behind eval(). */ | |
2321dd91 MM |
417 | TBB parent = m_set_chain[v]; |
418 | if (m_set_chain[parent]) | |
f8032688 | 419 | { |
2321dd91 MM |
420 | compress (parent); |
421 | if (m_key[m_path_min[parent]] < m_key[m_path_min[v]]) | |
422 | m_path_min[v] = m_path_min[parent]; | |
423 | m_set_chain[v] = m_set_chain[parent]; | |
f8032688 MM |
424 | } |
425 | } | |
426 | ||
427 | /* Compress the path from V to the set root of V if needed (when the root has | |
428 | changed since the last call). Returns the node with the smallest key[] | |
429 | value on the path from V to the root. */ | |
430 | ||
2321dd91 MM |
431 | inline TBB |
432 | dom_info::eval (TBB v) | |
f8032688 | 433 | { |
fa10beec | 434 | /* The representative of the set V is in, also called root (as the set |
f8032688 | 435 | representation is a tree). */ |
2321dd91 | 436 | TBB rep = m_set_chain[v]; |
f8032688 MM |
437 | |
438 | /* V itself is the root. */ | |
439 | if (!rep) | |
2321dd91 | 440 | return m_path_min[v]; |
f8032688 MM |
441 | |
442 | /* Compress only if necessary. */ | |
2321dd91 | 443 | if (m_set_chain[rep]) |
f8032688 | 444 | { |
2321dd91 MM |
445 | compress (v); |
446 | rep = m_set_chain[v]; | |
f8032688 MM |
447 | } |
448 | ||
2321dd91 MM |
449 | if (m_key[m_path_min[rep]] >= m_key[m_path_min[v]]) |
450 | return m_path_min[v]; | |
f8032688 | 451 | else |
2321dd91 | 452 | return m_path_min[rep]; |
f8032688 MM |
453 | } |
454 | ||
455 | /* This essentially merges the two sets of V and W, giving a single set with | |
456 | the new root V. The internal representation of these disjoint sets is a | |
457 | balanced tree. Currently link(V,W) is only used with V being the parent | |
458 | of W. */ | |
459 | ||
2321dd91 MM |
460 | void |
461 | dom_info::link_roots (TBB v, TBB w) | |
f8032688 MM |
462 | { |
463 | TBB s = w; | |
464 | ||
465 | /* Rebalance the tree. */ | |
2321dd91 | 466 | while (m_key[m_path_min[w]] < m_key[m_path_min[m_set_child[s]]]) |
f8032688 | 467 | { |
2321dd91 MM |
468 | if (m_set_size[s] + m_set_size[m_set_child[m_set_child[s]]] |
469 | >= 2 * m_set_size[m_set_child[s]]) | |
f8032688 | 470 | { |
2321dd91 MM |
471 | m_set_chain[m_set_child[s]] = s; |
472 | m_set_child[s] = m_set_child[m_set_child[s]]; | |
f8032688 MM |
473 | } |
474 | else | |
475 | { | |
2321dd91 MM |
476 | m_set_size[m_set_child[s]] = m_set_size[s]; |
477 | s = m_set_chain[s] = m_set_child[s]; | |
f8032688 MM |
478 | } |
479 | } | |
480 | ||
2321dd91 MM |
481 | m_path_min[s] = m_path_min[w]; |
482 | m_set_size[v] += m_set_size[w]; | |
483 | if (m_set_size[v] < 2 * m_set_size[w]) | |
484 | std::swap (m_set_child[v], s); | |
f8032688 MM |
485 | |
486 | /* Merge all subtrees. */ | |
487 | while (s) | |
488 | { | |
2321dd91 MM |
489 | m_set_chain[s] = v; |
490 | s = m_set_child[s]; | |
f8032688 MM |
491 | } |
492 | } | |
493 | ||
2321dd91 MM |
494 | /* This calculates the immediate dominators (or post-dominators). THIS is our |
495 | working structure and should hold the DFS forest. | |
496 | On return the immediate dominator to node V is in m_dom[V]. */ | |
f8032688 | 497 | |
2321dd91 MM |
498 | void |
499 | dom_info::calc_idoms () | |
f8032688 | 500 | { |
f8032688 | 501 | /* Go backwards in DFS order, to first look at the leafs. */ |
2321dd91 | 502 | for (TBB v = m_nodes; v > 1; v--) |
f8032688 | 503 | { |
2321dd91 | 504 | basic_block bb = m_dfs_to_bb[v]; |
628f6a4e | 505 | edge e; |
f8032688 | 506 | |
2321dd91 MM |
507 | TBB par = m_dfs_parent[v]; |
508 | TBB k = v; | |
628f6a4e | 509 | |
2321dd91 MM |
510 | edge_iterator ei = m_reverse ? ei_start (bb->succs) |
511 | : ei_start (bb->preds); | |
512 | edge_iterator einext; | |
628f6a4e | 513 | |
2321dd91 | 514 | if (m_reverse) |
26e0e410 | 515 | { |
26e0e410 | 516 | /* If this block has a fake edge to exit, process that first. */ |
2321dd91 | 517 | if (bitmap_bit_p (m_fake_exit_edge, bb->index)) |
26e0e410 | 518 | { |
628f6a4e BE |
519 | einext = ei; |
520 | einext.index = 0; | |
26e0e410 RH |
521 | goto do_fake_exit_edge; |
522 | } | |
523 | } | |
f8032688 MM |
524 | |
525 | /* Search all direct predecessors for the smallest node with a path | |
526 | to them. That way we have the smallest node with also a path to | |
527 | us only over nodes behind us. In effect we search for our | |
528 | semidominator. */ | |
628f6a4e | 529 | while (!ei_end_p (ei)) |
f8032688 | 530 | { |
f8032688 | 531 | basic_block b; |
2321dd91 | 532 | TBB k1; |
f8032688 | 533 | |
628f6a4e | 534 | e = ei_edge (ei); |
2321dd91 | 535 | b = m_reverse ? e->dest : e->src; |
628f6a4e BE |
536 | einext = ei; |
537 | ei_next (&einext); | |
538 | ||
2321dd91 | 539 | if (b == m_start_block) |
26e0e410 RH |
540 | { |
541 | do_fake_exit_edge: | |
2321dd91 | 542 | k1 = *m_dfs_last; |
26e0e410 | 543 | } |
f8032688 | 544 | else |
2321dd91 | 545 | k1 = m_dfs_order[b->index]; |
f8032688 MM |
546 | |
547 | /* Call eval() only if really needed. If k1 is above V in DFS tree, | |
548 | then we know, that eval(k1) == k1 and key[k1] == k1. */ | |
549 | if (k1 > v) | |
2321dd91 | 550 | k1 = m_key[eval (k1)]; |
f8032688 MM |
551 | if (k1 < k) |
552 | k = k1; | |
628f6a4e BE |
553 | |
554 | ei = einext; | |
f8032688 MM |
555 | } |
556 | ||
2321dd91 MM |
557 | m_key[v] = k; |
558 | link_roots (par, v); | |
559 | m_next_bucket[v] = m_bucket[k]; | |
560 | m_bucket[k] = v; | |
f8032688 MM |
561 | |
562 | /* Transform semidominators into dominators. */ | |
2321dd91 | 563 | for (TBB w = m_bucket[par]; w; w = m_next_bucket[w]) |
f8032688 | 564 | { |
2321dd91 MM |
565 | k = eval (w); |
566 | if (m_key[k] < m_key[w]) | |
567 | m_dom[w] = k; | |
f8032688 | 568 | else |
2321dd91 | 569 | m_dom[w] = par; |
f8032688 MM |
570 | } |
571 | /* We don't need to cleanup next_bucket[]. */ | |
2321dd91 | 572 | m_bucket[par] = 0; |
f8032688 MM |
573 | } |
574 | ||
a1f300c0 | 575 | /* Explicitly define the dominators. */ |
2321dd91 MM |
576 | m_dom[1] = 0; |
577 | for (TBB v = 2; v <= m_nodes; v++) | |
578 | if (m_dom[v] != m_key[v]) | |
579 | m_dom[v] = m_dom[m_dom[v]]; | |
f8032688 MM |
580 | } |
581 | ||
d47cc544 SB |
582 | /* Assign dfs numbers starting from NUM to NODE and its sons. */ |
583 | ||
584 | static void | |
585 | assign_dfs_numbers (struct et_node *node, int *num) | |
586 | { | |
587 | struct et_node *son; | |
588 | ||
589 | node->dfs_num_in = (*num)++; | |
590 | ||
591 | if (node->son) | |
592 | { | |
593 | assign_dfs_numbers (node->son, num); | |
594 | for (son = node->son->right; son != node->son; son = son->right) | |
6de9cd9a | 595 | assign_dfs_numbers (son, num); |
d47cc544 | 596 | } |
f8032688 | 597 | |
d47cc544 SB |
598 | node->dfs_num_out = (*num)++; |
599 | } | |
f8032688 | 600 | |
5d3cc252 | 601 | /* Compute the data necessary for fast resolving of dominator queries in a |
d47cc544 | 602 | static dominator tree. */ |
f8032688 | 603 | |
d47cc544 SB |
604 | static void |
605 | compute_dom_fast_query (enum cdi_direction dir) | |
606 | { | |
607 | int num = 0; | |
608 | basic_block bb; | |
2b28c07a | 609 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
d47cc544 | 610 | |
2ba31c05 | 611 | gcc_checking_assert (dom_info_available_p (dir)); |
d47cc544 | 612 | |
2b28c07a | 613 | if (dom_computed[dir_index] == DOM_OK) |
d47cc544 SB |
614 | return; |
615 | ||
04a90bec | 616 | FOR_ALL_BB_FN (bb, cfun) |
d47cc544 | 617 | { |
2b28c07a JC |
618 | if (!bb->dom[dir_index]->father) |
619 | assign_dfs_numbers (bb->dom[dir_index], &num); | |
d47cc544 SB |
620 | } |
621 | ||
2b28c07a | 622 | dom_computed[dir_index] = DOM_OK; |
d47cc544 SB |
623 | } |
624 | ||
625 | /* The main entry point into this module. DIR is set depending on whether | |
626 | we want to compute dominators or postdominators. */ | |
627 | ||
628 | void | |
2321dd91 | 629 | calculate_dominance_info (cdi_direction dir) |
f8032688 | 630 | { |
2b28c07a | 631 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
355be0dc | 632 | |
2b28c07a | 633 | if (dom_computed[dir_index] == DOM_OK) |
f3c676e1 | 634 | { |
b2b29377 | 635 | checking_verify_dominators (dir); |
f3c676e1 TV |
636 | return; |
637 | } | |
355be0dc | 638 | |
74c96e0c | 639 | timevar_push (TV_DOMINANCE); |
fce22de5 | 640 | if (!dom_info_available_p (dir)) |
d47cc544 | 641 | { |
2b28c07a | 642 | gcc_assert (!n_bbs_in_dom_tree[dir_index]); |
f8032688 | 643 | |
2321dd91 | 644 | basic_block b; |
04a90bec | 645 | FOR_ALL_BB_FN (b, cfun) |
d47cc544 | 646 | { |
2b28c07a | 647 | b->dom[dir_index] = et_new_tree (b); |
d47cc544 | 648 | } |
0cae8d31 | 649 | n_bbs_in_dom_tree[dir_index] = n_basic_blocks_for_fn (cfun); |
f8032688 | 650 | |
2321dd91 MM |
651 | dom_info di (cfun, dir); |
652 | di.calc_dfs_tree (); | |
653 | di.calc_idoms (); | |
355be0dc | 654 | |
11cd3bed | 655 | FOR_EACH_BB_FN (b, cfun) |
d47cc544 | 656 | { |
2321dd91 MM |
657 | if (basic_block d = di.get_idom (b)) |
658 | et_set_father (b->dom[dir_index], d->dom[dir_index]); | |
d47cc544 | 659 | } |
e0082a72 | 660 | |
2b28c07a | 661 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; |
355be0dc | 662 | } |
4081bdd2 | 663 | else |
b2b29377 | 664 | checking_verify_dominators (dir); |
355be0dc | 665 | |
d47cc544 | 666 | compute_dom_fast_query (dir); |
74c96e0c ZD |
667 | |
668 | timevar_pop (TV_DOMINANCE); | |
355be0dc JH |
669 | } |
670 | ||
d47cc544 | 671 | /* Free dominance information for direction DIR. */ |
355be0dc | 672 | void |
e3f613cb | 673 | free_dominance_info (function *fn, enum cdi_direction dir) |
355be0dc JH |
674 | { |
675 | basic_block bb; | |
2b28c07a | 676 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
355be0dc | 677 | |
e3f613cb | 678 | if (!dom_info_available_p (fn, dir)) |
d47cc544 SB |
679 | return; |
680 | ||
e3f613cb | 681 | FOR_ALL_BB_FN (bb, fn) |
d47cc544 | 682 | { |
2b28c07a JC |
683 | et_free_tree_force (bb->dom[dir_index]); |
684 | bb->dom[dir_index] = NULL; | |
d47cc544 | 685 | } |
5a6ccafd | 686 | et_free_pools (); |
d47cc544 | 687 | |
e3f613cb RB |
688 | fn->cfg->x_n_bbs_in_dom_tree[dir_index] = 0; |
689 | ||
690 | fn->cfg->x_dom_computed[dir_index] = DOM_NONE; | |
691 | } | |
6de9cd9a | 692 | |
e3f613cb RB |
693 | void |
694 | free_dominance_info (enum cdi_direction dir) | |
695 | { | |
696 | free_dominance_info (cfun, dir); | |
355be0dc JH |
697 | } |
698 | ||
699 | /* Return the immediate dominator of basic block BB. */ | |
700 | basic_block | |
d47cc544 | 701 | get_immediate_dominator (enum cdi_direction dir, basic_block bb) |
355be0dc | 702 | { |
2b28c07a JC |
703 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
704 | struct et_node *node = bb->dom[dir_index]; | |
d47cc544 | 705 | |
2ba31c05 | 706 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 SB |
707 | |
708 | if (!node->father) | |
709 | return NULL; | |
710 | ||
f883e0a7 | 711 | return (basic_block) node->father->data; |
355be0dc JH |
712 | } |
713 | ||
714 | /* Set the immediate dominator of the block possibly removing | |
715 | existing edge. NULL can be used to remove any edge. */ | |
7031a8b9 | 716 | void |
d47cc544 SB |
717 | set_immediate_dominator (enum cdi_direction dir, basic_block bb, |
718 | basic_block dominated_by) | |
355be0dc | 719 | { |
2b28c07a JC |
720 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
721 | struct et_node *node = bb->dom[dir_index]; | |
b8698a0f | 722 | |
2ba31c05 | 723 | gcc_checking_assert (dom_computed[dir_index]); |
355be0dc | 724 | |
d47cc544 | 725 | if (node->father) |
355be0dc | 726 | { |
d47cc544 | 727 | if (node->father->data == dominated_by) |
6de9cd9a | 728 | return; |
d47cc544 | 729 | et_split (node); |
355be0dc | 730 | } |
d47cc544 SB |
731 | |
732 | if (dominated_by) | |
2b28c07a | 733 | et_set_father (node, dominated_by->dom[dir_index]); |
d47cc544 | 734 | |
2b28c07a JC |
735 | if (dom_computed[dir_index] == DOM_OK) |
736 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
355be0dc JH |
737 | } |
738 | ||
66f97d31 ZD |
739 | /* Returns the list of basic blocks immediately dominated by BB, in the |
740 | direction DIR. */ | |
9771b263 | 741 | vec<basic_block> |
66f97d31 | 742 | get_dominated_by (enum cdi_direction dir, basic_block bb) |
355be0dc | 743 | { |
66f97d31 | 744 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
2b28c07a | 745 | struct et_node *node = bb->dom[dir_index], *son = node->son, *ason; |
6e1aa848 | 746 | vec<basic_block> bbs = vNULL; |
66f97d31 | 747 | |
2ba31c05 | 748 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 SB |
749 | |
750 | if (!son) | |
6e1aa848 | 751 | return vNULL; |
d47cc544 | 752 | |
9771b263 | 753 | bbs.safe_push ((basic_block) son->data); |
2d888286 | 754 | for (ason = son->right; ason != son; ason = ason->right) |
9771b263 | 755 | bbs.safe_push ((basic_block) ason->data); |
355be0dc | 756 | |
66f97d31 | 757 | return bbs; |
355be0dc JH |
758 | } |
759 | ||
66f97d31 ZD |
760 | /* Returns the list of basic blocks that are immediately dominated (in |
761 | direction DIR) by some block between N_REGION ones stored in REGION, | |
762 | except for blocks in the REGION itself. */ | |
b8698a0f | 763 | |
9771b263 | 764 | vec<basic_block> |
42759f1e | 765 | get_dominated_by_region (enum cdi_direction dir, basic_block *region, |
66f97d31 | 766 | unsigned n_region) |
42759f1e | 767 | { |
66f97d31 | 768 | unsigned i; |
42759f1e | 769 | basic_block dom; |
6e1aa848 | 770 | vec<basic_block> doms = vNULL; |
42759f1e ZD |
771 | |
772 | for (i = 0; i < n_region; i++) | |
6580ee77 | 773 | region[i]->flags |= BB_DUPLICATED; |
42759f1e ZD |
774 | for (i = 0; i < n_region; i++) |
775 | for (dom = first_dom_son (dir, region[i]); | |
776 | dom; | |
777 | dom = next_dom_son (dir, dom)) | |
6580ee77 | 778 | if (!(dom->flags & BB_DUPLICATED)) |
9771b263 | 779 | doms.safe_push (dom); |
42759f1e | 780 | for (i = 0; i < n_region; i++) |
6580ee77 | 781 | region[i]->flags &= ~BB_DUPLICATED; |
42759f1e | 782 | |
66f97d31 | 783 | return doms; |
42759f1e ZD |
784 | } |
785 | ||
438c239d | 786 | /* Returns the list of basic blocks including BB dominated by BB, in the |
cad9aa15 MK |
787 | direction DIR up to DEPTH in the dominator tree. The DEPTH of zero will |
788 | produce a vector containing all dominated blocks. The vector will be sorted | |
789 | in preorder. */ | |
438c239d | 790 | |
9771b263 | 791 | vec<basic_block> |
cad9aa15 | 792 | get_dominated_to_depth (enum cdi_direction dir, basic_block bb, int depth) |
438c239d | 793 | { |
6e1aa848 | 794 | vec<basic_block> bbs = vNULL; |
438c239d | 795 | unsigned i; |
cad9aa15 | 796 | unsigned next_level_start; |
438c239d RG |
797 | |
798 | i = 0; | |
9771b263 DN |
799 | bbs.safe_push (bb); |
800 | next_level_start = 1; /* = bbs.length (); */ | |
438c239d RG |
801 | |
802 | do | |
803 | { | |
804 | basic_block son; | |
805 | ||
9771b263 | 806 | bb = bbs[i++]; |
438c239d RG |
807 | for (son = first_dom_son (dir, bb); |
808 | son; | |
809 | son = next_dom_son (dir, son)) | |
9771b263 | 810 | bbs.safe_push (son); |
cad9aa15 MK |
811 | |
812 | if (i == next_level_start && --depth) | |
9771b263 | 813 | next_level_start = bbs.length (); |
438c239d | 814 | } |
cad9aa15 | 815 | while (i < next_level_start); |
438c239d RG |
816 | |
817 | return bbs; | |
818 | } | |
819 | ||
cad9aa15 MK |
820 | /* Returns the list of basic blocks including BB dominated by BB, in the |
821 | direction DIR. The vector will be sorted in preorder. */ | |
822 | ||
9771b263 | 823 | vec<basic_block> |
cad9aa15 MK |
824 | get_all_dominated_blocks (enum cdi_direction dir, basic_block bb) |
825 | { | |
826 | return get_dominated_to_depth (dir, bb, 0); | |
827 | } | |
828 | ||
355be0dc JH |
829 | /* Redirect all edges pointing to BB to TO. */ |
830 | void | |
d47cc544 SB |
831 | redirect_immediate_dominators (enum cdi_direction dir, basic_block bb, |
832 | basic_block to) | |
355be0dc | 833 | { |
2b28c07a JC |
834 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
835 | struct et_node *bb_node, *to_node, *son; | |
b8698a0f | 836 | |
2b28c07a JC |
837 | bb_node = bb->dom[dir_index]; |
838 | to_node = to->dom[dir_index]; | |
d47cc544 | 839 | |
2ba31c05 | 840 | gcc_checking_assert (dom_computed[dir_index]); |
355be0dc | 841 | |
d47cc544 SB |
842 | if (!bb_node->son) |
843 | return; | |
844 | ||
845 | while (bb_node->son) | |
355be0dc | 846 | { |
d47cc544 SB |
847 | son = bb_node->son; |
848 | ||
849 | et_split (son); | |
850 | et_set_father (son, to_node); | |
355be0dc | 851 | } |
d47cc544 | 852 | |
2b28c07a JC |
853 | if (dom_computed[dir_index] == DOM_OK) |
854 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
355be0dc JH |
855 | } |
856 | ||
857 | /* Find first basic block in the tree dominating both BB1 and BB2. */ | |
858 | basic_block | |
d47cc544 | 859 | nearest_common_dominator (enum cdi_direction dir, basic_block bb1, basic_block bb2) |
355be0dc | 860 | { |
2b28c07a JC |
861 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
862 | ||
2ba31c05 | 863 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 864 | |
355be0dc JH |
865 | if (!bb1) |
866 | return bb2; | |
867 | if (!bb2) | |
868 | return bb1; | |
d47cc544 | 869 | |
f883e0a7 | 870 | return (basic_block) et_nca (bb1->dom[dir_index], bb2->dom[dir_index])->data; |
355be0dc JH |
871 | } |
872 | ||
0bca51f0 DN |
873 | |
874 | /* Find the nearest common dominator for the basic blocks in BLOCKS, | |
875 | using dominance direction DIR. */ | |
876 | ||
877 | basic_block | |
878 | nearest_common_dominator_for_set (enum cdi_direction dir, bitmap blocks) | |
879 | { | |
880 | unsigned i, first; | |
881 | bitmap_iterator bi; | |
882 | basic_block dom; | |
b8698a0f | 883 | |
0bca51f0 | 884 | first = bitmap_first_set_bit (blocks); |
06e28de2 | 885 | dom = BASIC_BLOCK_FOR_FN (cfun, first); |
0bca51f0 | 886 | EXECUTE_IF_SET_IN_BITMAP (blocks, 0, i, bi) |
06e28de2 DM |
887 | if (dom != BASIC_BLOCK_FOR_FN (cfun, i)) |
888 | dom = nearest_common_dominator (dir, dom, BASIC_BLOCK_FOR_FN (cfun, i)); | |
0bca51f0 DN |
889 | |
890 | return dom; | |
891 | } | |
892 | ||
b629276a DB |
893 | /* Given a dominator tree, we can determine whether one thing |
894 | dominates another in constant time by using two DFS numbers: | |
895 | ||
896 | 1. The number for when we visit a node on the way down the tree | |
897 | 2. The number for when we visit a node on the way back up the tree | |
898 | ||
899 | You can view these as bounds for the range of dfs numbers the | |
900 | nodes in the subtree of the dominator tree rooted at that node | |
901 | will contain. | |
b8698a0f | 902 | |
b629276a DB |
903 | The dominator tree is always a simple acyclic tree, so there are |
904 | only three possible relations two nodes in the dominator tree have | |
905 | to each other: | |
b8698a0f | 906 | |
b629276a DB |
907 | 1. Node A is above Node B (and thus, Node A dominates node B) |
908 | ||
909 | A | |
910 | | | |
911 | C | |
912 | / \ | |
913 | B D | |
914 | ||
915 | ||
916 | In the above case, DFS_Number_In of A will be <= DFS_Number_In of | |
917 | B, and DFS_Number_Out of A will be >= DFS_Number_Out of B. This is | |
918 | because we must hit A in the dominator tree *before* B on the walk | |
919 | down, and we will hit A *after* B on the walk back up | |
b8698a0f | 920 | |
d8701f02 | 921 | 2. Node A is below node B (and thus, node B dominates node A) |
b8698a0f L |
922 | |
923 | ||
b629276a DB |
924 | B |
925 | | | |
926 | A | |
927 | / \ | |
928 | C D | |
929 | ||
930 | In the above case, DFS_Number_In of A will be >= DFS_Number_In of | |
931 | B, and DFS_Number_Out of A will be <= DFS_Number_Out of B. | |
b8698a0f | 932 | |
b629276a DB |
933 | This is because we must hit A in the dominator tree *after* B on |
934 | the walk down, and we will hit A *before* B on the walk back up | |
b8698a0f | 935 | |
b629276a DB |
936 | 3. Node A and B are siblings (and thus, neither dominates the other) |
937 | ||
938 | C | |
939 | | | |
940 | D | |
941 | / \ | |
942 | A B | |
943 | ||
944 | In the above case, DFS_Number_In of A will *always* be <= | |
945 | DFS_Number_In of B, and DFS_Number_Out of A will *always* be <= | |
946 | DFS_Number_Out of B. This is because we will always finish the dfs | |
947 | walk of one of the subtrees before the other, and thus, the dfs | |
948 | numbers for one subtree can't intersect with the range of dfs | |
949 | numbers for the other subtree. If you swap A and B's position in | |
950 | the dominator tree, the comparison changes direction, but the point | |
951 | is that both comparisons will always go the same way if there is no | |
952 | dominance relationship. | |
953 | ||
954 | Thus, it is sufficient to write | |
955 | ||
956 | A_Dominates_B (node A, node B) | |
957 | { | |
b8698a0f | 958 | return DFS_Number_In(A) <= DFS_Number_In(B) |
b629276a DB |
959 | && DFS_Number_Out (A) >= DFS_Number_Out(B); |
960 | } | |
961 | ||
962 | A_Dominated_by_B (node A, node B) | |
963 | { | |
048f1a9c | 964 | return DFS_Number_In(A) >= DFS_Number_In(B) |
b629276a DB |
965 | && DFS_Number_Out (A) <= DFS_Number_Out(B); |
966 | } */ | |
0bca51f0 | 967 | |
355be0dc JH |
968 | /* Return TRUE in case BB1 is dominated by BB2. */ |
969 | bool | |
ed7a4b4b | 970 | dominated_by_p (enum cdi_direction dir, const_basic_block bb1, const_basic_block bb2) |
b8698a0f | 971 | { |
2b28c07a JC |
972 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
973 | struct et_node *n1 = bb1->dom[dir_index], *n2 = bb2->dom[dir_index]; | |
b8698a0f | 974 | |
2ba31c05 | 975 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 976 | |
2b28c07a | 977 | if (dom_computed[dir_index] == DOM_OK) |
d47cc544 | 978 | return (n1->dfs_num_in >= n2->dfs_num_in |
6de9cd9a | 979 | && n1->dfs_num_out <= n2->dfs_num_out); |
d47cc544 SB |
980 | |
981 | return et_below (n1, n2); | |
355be0dc JH |
982 | } |
983 | ||
f074ff6c ZD |
984 | /* Returns the entry dfs number for basic block BB, in the direction DIR. */ |
985 | ||
986 | unsigned | |
987 | bb_dom_dfs_in (enum cdi_direction dir, basic_block bb) | |
988 | { | |
2b28c07a JC |
989 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
990 | struct et_node *n = bb->dom[dir_index]; | |
f074ff6c | 991 | |
2ba31c05 | 992 | gcc_checking_assert (dom_computed[dir_index] == DOM_OK); |
f074ff6c ZD |
993 | return n->dfs_num_in; |
994 | } | |
995 | ||
996 | /* Returns the exit dfs number for basic block BB, in the direction DIR. */ | |
997 | ||
998 | unsigned | |
999 | bb_dom_dfs_out (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_out; |
1006 | } | |
1007 | ||
355be0dc | 1008 | /* Verify invariants of dominator structure. */ |
24e47c76 | 1009 | DEBUG_FUNCTION void |
2321dd91 | 1010 | verify_dominators (cdi_direction dir) |
355be0dc | 1011 | { |
fce22de5 | 1012 | gcc_assert (dom_info_available_p (dir)); |
d47cc544 | 1013 | |
2321dd91 MM |
1014 | dom_info di (cfun, dir); |
1015 | di.calc_dfs_tree (); | |
1016 | di.calc_idoms (); | |
1fc3998d | 1017 | |
2321dd91 MM |
1018 | bool err = false; |
1019 | basic_block bb; | |
11cd3bed | 1020 | FOR_EACH_BB_FN (bb, cfun) |
355be0dc | 1021 | { |
2321dd91 | 1022 | basic_block imm_bb = get_immediate_dominator (dir, bb); |
1fc3998d | 1023 | if (!imm_bb) |
f8032688 | 1024 | { |
66f97d31 | 1025 | error ("dominator of %d status unknown", bb->index); |
2321dd91 | 1026 | err = true; |
355be0dc | 1027 | } |
66f97d31 | 1028 | |
2321dd91 | 1029 | basic_block imm_bb_correct = di.get_idom (bb); |
1fc3998d | 1030 | if (imm_bb != imm_bb_correct) |
e7bd94cc | 1031 | { |
66f97d31 | 1032 | error ("dominator of %d should be %d, not %d", |
1fc3998d | 1033 | bb->index, imm_bb_correct->index, imm_bb->index); |
2321dd91 | 1034 | err = true; |
e7bd94cc ZD |
1035 | } |
1036 | } | |
1037 | ||
ced3f397 | 1038 | gcc_assert (!err); |
355be0dc JH |
1039 | } |
1040 | ||
738ed977 ZD |
1041 | /* Determine immediate dominator (or postdominator, according to DIR) of BB, |
1042 | assuming that dominators of other blocks are correct. We also use it to | |
1043 | recompute the dominators in a restricted area, by iterating it until it | |
71cc389b | 1044 | reaches a fixed point. */ |
738ed977 | 1045 | |
355be0dc | 1046 | basic_block |
66f97d31 | 1047 | recompute_dominator (enum cdi_direction dir, basic_block bb) |
355be0dc | 1048 | { |
2b28c07a | 1049 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
738ed977 ZD |
1050 | basic_block dom_bb = NULL; |
1051 | edge e; | |
628f6a4e | 1052 | edge_iterator ei; |
355be0dc | 1053 | |
2ba31c05 | 1054 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 1055 | |
738ed977 ZD |
1056 | if (dir == CDI_DOMINATORS) |
1057 | { | |
628f6a4e | 1058 | FOR_EACH_EDGE (e, ei, bb->preds) |
738ed977 ZD |
1059 | { |
1060 | if (!dominated_by_p (dir, e->src, bb)) | |
1061 | dom_bb = nearest_common_dominator (dir, dom_bb, e->src); | |
1062 | } | |
1063 | } | |
1064 | else | |
1065 | { | |
628f6a4e | 1066 | FOR_EACH_EDGE (e, ei, bb->succs) |
738ed977 ZD |
1067 | { |
1068 | if (!dominated_by_p (dir, e->dest, bb)) | |
1069 | dom_bb = nearest_common_dominator (dir, dom_bb, e->dest); | |
1070 | } | |
1071 | } | |
f8032688 | 1072 | |
738ed977 | 1073 | return dom_bb; |
355be0dc JH |
1074 | } |
1075 | ||
66f97d31 ZD |
1076 | /* Use simple heuristics (see iterate_fix_dominators) to determine dominators |
1077 | of BBS. We assume that all the immediate dominators except for those of the | |
1078 | blocks in BBS are correct. If CONSERVATIVE is true, we also assume that the | |
1079 | currently recorded immediate dominators of blocks in BBS really dominate the | |
1080 | blocks. The basic blocks for that we determine the dominator are removed | |
1081 | from BBS. */ | |
1082 | ||
1083 | static void | |
9771b263 | 1084 | prune_bbs_to_update_dominators (vec<basic_block> bbs, |
66f97d31 ZD |
1085 | bool conservative) |
1086 | { | |
1087 | unsigned i; | |
1088 | bool single; | |
1089 | basic_block bb, dom = NULL; | |
1090 | edge_iterator ei; | |
1091 | edge e; | |
1092 | ||
9771b263 | 1093 | for (i = 0; bbs.iterate (i, &bb);) |
66f97d31 | 1094 | { |
fefa31b5 | 1095 | if (bb == ENTRY_BLOCK_PTR_FOR_FN (cfun)) |
66f97d31 ZD |
1096 | goto succeed; |
1097 | ||
1098 | if (single_pred_p (bb)) | |
1099 | { | |
1100 | set_immediate_dominator (CDI_DOMINATORS, bb, single_pred (bb)); | |
1101 | goto succeed; | |
1102 | } | |
1103 | ||
1104 | if (!conservative) | |
1105 | goto fail; | |
1106 | ||
1107 | single = true; | |
1108 | dom = NULL; | |
1109 | FOR_EACH_EDGE (e, ei, bb->preds) | |
1110 | { | |
1111 | if (dominated_by_p (CDI_DOMINATORS, e->src, bb)) | |
1112 | continue; | |
1113 | ||
1114 | if (!dom) | |
1115 | dom = e->src; | |
1116 | else | |
1117 | { | |
1118 | single = false; | |
1119 | dom = nearest_common_dominator (CDI_DOMINATORS, dom, e->src); | |
1120 | } | |
1121 | } | |
1122 | ||
1123 | gcc_assert (dom != NULL); | |
1124 | if (single | |
1125 | || find_edge (dom, bb)) | |
1126 | { | |
1127 | set_immediate_dominator (CDI_DOMINATORS, bb, dom); | |
1128 | goto succeed; | |
1129 | } | |
1130 | ||
1131 | fail: | |
1132 | i++; | |
1133 | continue; | |
1134 | ||
1135 | succeed: | |
9771b263 | 1136 | bbs.unordered_remove (i); |
66f97d31 ZD |
1137 | } |
1138 | } | |
1139 | ||
1140 | /* Returns root of the dominance tree in the direction DIR that contains | |
1141 | BB. */ | |
1142 | ||
1143 | static basic_block | |
1144 | root_of_dom_tree (enum cdi_direction dir, basic_block bb) | |
1145 | { | |
f883e0a7 | 1146 | return (basic_block) et_root (bb->dom[dom_convert_dir_to_idx (dir)])->data; |
66f97d31 ZD |
1147 | } |
1148 | ||
1149 | /* See the comment in iterate_fix_dominators. Finds the immediate dominators | |
1150 | for the sons of Y, found using the SON and BROTHER arrays representing | |
1151 | the dominance tree of graph G. BBS maps the vertices of G to the basic | |
1152 | blocks. */ | |
1153 | ||
1154 | static void | |
9771b263 | 1155 | determine_dominators_for_sons (struct graph *g, vec<basic_block> bbs, |
66f97d31 ZD |
1156 | int y, int *son, int *brother) |
1157 | { | |
1158 | bitmap gprime; | |
1159 | int i, a, nc; | |
9771b263 | 1160 | vec<int> *sccs; |
66f97d31 ZD |
1161 | basic_block bb, dom, ybb; |
1162 | unsigned si; | |
1163 | edge e; | |
1164 | edge_iterator ei; | |
1165 | ||
1166 | if (son[y] == -1) | |
1167 | return; | |
9771b263 | 1168 | if (y == (int) bbs.length ()) |
fefa31b5 | 1169 | ybb = ENTRY_BLOCK_PTR_FOR_FN (cfun); |
66f97d31 | 1170 | else |
9771b263 | 1171 | ybb = bbs[y]; |
66f97d31 ZD |
1172 | |
1173 | if (brother[son[y]] == -1) | |
1174 | { | |
1175 | /* Handle the common case Y has just one son specially. */ | |
9771b263 | 1176 | bb = bbs[son[y]]; |
66f97d31 ZD |
1177 | set_immediate_dominator (CDI_DOMINATORS, bb, |
1178 | recompute_dominator (CDI_DOMINATORS, bb)); | |
1179 | identify_vertices (g, y, son[y]); | |
1180 | return; | |
1181 | } | |
1182 | ||
1183 | gprime = BITMAP_ALLOC (NULL); | |
1184 | for (a = son[y]; a != -1; a = brother[a]) | |
1185 | bitmap_set_bit (gprime, a); | |
1186 | ||
1187 | nc = graphds_scc (g, gprime); | |
1188 | BITMAP_FREE (gprime); | |
1189 | ||
9771b263 DN |
1190 | /* ??? Needed to work around the pre-processor confusion with |
1191 | using a multi-argument template type as macro argument. */ | |
1192 | typedef vec<int> vec_int_heap; | |
1193 | sccs = XCNEWVEC (vec_int_heap, nc); | |
66f97d31 | 1194 | for (a = son[y]; a != -1; a = brother[a]) |
9771b263 | 1195 | sccs[g->vertices[a].component].safe_push (a); |
66f97d31 ZD |
1196 | |
1197 | for (i = nc - 1; i >= 0; i--) | |
1198 | { | |
1199 | dom = NULL; | |
9771b263 | 1200 | FOR_EACH_VEC_ELT (sccs[i], si, a) |
66f97d31 | 1201 | { |
9771b263 | 1202 | bb = bbs[a]; |
66f97d31 ZD |
1203 | FOR_EACH_EDGE (e, ei, bb->preds) |
1204 | { | |
1205 | if (root_of_dom_tree (CDI_DOMINATORS, e->src) != ybb) | |
1206 | continue; | |
1207 | ||
1208 | dom = nearest_common_dominator (CDI_DOMINATORS, dom, e->src); | |
1209 | } | |
1210 | } | |
1211 | ||
1212 | gcc_assert (dom != NULL); | |
9771b263 | 1213 | FOR_EACH_VEC_ELT (sccs[i], si, a) |
66f97d31 | 1214 | { |
9771b263 | 1215 | bb = bbs[a]; |
66f97d31 ZD |
1216 | set_immediate_dominator (CDI_DOMINATORS, bb, dom); |
1217 | } | |
1218 | } | |
1219 | ||
1220 | for (i = 0; i < nc; i++) | |
9771b263 | 1221 | sccs[i].release (); |
66f97d31 ZD |
1222 | free (sccs); |
1223 | ||
1224 | for (a = son[y]; a != -1; a = brother[a]) | |
1225 | identify_vertices (g, y, a); | |
1226 | } | |
1227 | ||
1228 | /* Recompute dominance information for basic blocks in the set BBS. The | |
1229 | function assumes that the immediate dominators of all the other blocks | |
1230 | in CFG are correct, and that there are no unreachable blocks. | |
1231 | ||
1232 | If CONSERVATIVE is true, we additionally assume that all the ancestors of | |
1233 | a block of BBS in the current dominance tree dominate it. */ | |
1234 | ||
355be0dc | 1235 | void |
9771b263 | 1236 | iterate_fix_dominators (enum cdi_direction dir, vec<basic_block> bbs, |
66f97d31 | 1237 | bool conservative) |
355be0dc | 1238 | { |
66f97d31 ZD |
1239 | unsigned i; |
1240 | basic_block bb, dom; | |
1241 | struct graph *g; | |
1242 | int n, y; | |
1243 | size_t dom_i; | |
1244 | edge e; | |
1245 | edge_iterator ei; | |
66f97d31 | 1246 | int *parent, *son, *brother; |
2b28c07a | 1247 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
355be0dc | 1248 | |
66f97d31 ZD |
1249 | /* We only support updating dominators. There are some problems with |
1250 | updating postdominators (need to add fake edges from infinite loops | |
1251 | and noreturn functions), and since we do not currently use | |
1252 | iterate_fix_dominators for postdominators, any attempt to handle these | |
1253 | problems would be unused, untested, and almost surely buggy. We keep | |
1254 | the DIR argument for consistency with the rest of the dominator analysis | |
1255 | interface. */ | |
2ba31c05 | 1256 | gcc_checking_assert (dir == CDI_DOMINATORS && dom_computed[dir_index]); |
d47cc544 | 1257 | |
66f97d31 ZD |
1258 | /* The algorithm we use takes inspiration from the following papers, although |
1259 | the details are quite different from any of them: | |
1260 | ||
1261 | [1] G. Ramalingam, T. Reps, An Incremental Algorithm for Maintaining the | |
1262 | Dominator Tree of a Reducible Flowgraph | |
1263 | [2] V. C. Sreedhar, G. R. Gao, Y.-F. Lee: Incremental computation of | |
1264 | dominator trees | |
1265 | [3] K. D. Cooper, T. J. Harvey and K. Kennedy: A Simple, Fast Dominance | |
1266 | Algorithm | |
1267 | ||
1268 | First, we use the following heuristics to decrease the size of the BBS | |
1269 | set: | |
1270 | a) if BB has a single predecessor, then its immediate dominator is this | |
1271 | predecessor | |
1272 | additionally, if CONSERVATIVE is true: | |
1273 | b) if all the predecessors of BB except for one (X) are dominated by BB, | |
1274 | then X is the immediate dominator of BB | |
1275 | c) if the nearest common ancestor of the predecessors of BB is X and | |
1276 | X -> BB is an edge in CFG, then X is the immediate dominator of BB | |
1277 | ||
1278 | Then, we need to establish the dominance relation among the basic blocks | |
1279 | in BBS. We split the dominance tree by removing the immediate dominator | |
0d52bcc1 | 1280 | edges from BBS, creating a forest F. We form a graph G whose vertices |
66f97d31 | 1281 | are BBS and ENTRY and X -> Y is an edge of G if there exists an edge |
0d52bcc1 | 1282 | X' -> Y in CFG such that X' belongs to the tree of the dominance forest |
66f97d31 ZD |
1283 | whose root is X. We then determine dominance tree of G. Note that |
1284 | for X, Y in BBS, X dominates Y in CFG if and only if X dominates Y in G. | |
1285 | In this step, we can use arbitrary algorithm to determine dominators. | |
1286 | We decided to prefer the algorithm [3] to the algorithm of | |
1287 | Lengauer and Tarjan, since the set BBS is usually small (rarely exceeding | |
1288 | 10 during gcc bootstrap), and [3] should perform better in this case. | |
1289 | ||
1290 | Finally, we need to determine the immediate dominators for the basic | |
1291 | blocks of BBS. If the immediate dominator of X in G is Y, then | |
1292 | the immediate dominator of X in CFG belongs to the tree of F rooted in | |
1293 | Y. We process the dominator tree T of G recursively, starting from leaves. | |
1294 | Suppose that X_1, X_2, ..., X_k are the sons of Y in T, and that the | |
1295 | subtrees of the dominance tree of CFG rooted in X_i are already correct. | |
1296 | Let G' be the subgraph of G induced by {X_1, X_2, ..., X_k}. We make | |
1297 | the following observations: | |
1298 | (i) the immediate dominator of all blocks in a strongly connected | |
1299 | component of G' is the same | |
1300 | (ii) if X has no predecessors in G', then the immediate dominator of X | |
1301 | is the nearest common ancestor of the predecessors of X in the | |
1302 | subtree of F rooted in Y | |
1303 | Therefore, it suffices to find the topological ordering of G', and | |
1304 | process the nodes X_i in this order using the rules (i) and (ii). | |
1305 | Then, we contract all the nodes X_i with Y in G, so that the further | |
1306 | steps work correctly. */ | |
1307 | ||
1308 | if (!conservative) | |
1309 | { | |
1310 | /* Split the tree now. If the idoms of blocks in BBS are not | |
1311 | conservatively correct, setting the dominators using the | |
1312 | heuristics in prune_bbs_to_update_dominators could | |
1313 | create cycles in the dominance "tree", and cause ICE. */ | |
9771b263 | 1314 | FOR_EACH_VEC_ELT (bbs, i, bb) |
66f97d31 ZD |
1315 | set_immediate_dominator (CDI_DOMINATORS, bb, NULL); |
1316 | } | |
1317 | ||
1318 | prune_bbs_to_update_dominators (bbs, conservative); | |
9771b263 | 1319 | n = bbs.length (); |
66f97d31 ZD |
1320 | |
1321 | if (n == 0) | |
1322 | return; | |
e7bd94cc | 1323 | |
66f97d31 | 1324 | if (n == 1) |
355be0dc | 1325 | { |
9771b263 | 1326 | bb = bbs[0]; |
66f97d31 ZD |
1327 | set_immediate_dominator (CDI_DOMINATORS, bb, |
1328 | recompute_dominator (CDI_DOMINATORS, bb)); | |
1329 | return; | |
1330 | } | |
1331 | ||
1332 | /* Construct the graph G. */ | |
1eb68d2d | 1333 | hash_map<basic_block, int> map (251); |
9771b263 | 1334 | FOR_EACH_VEC_ELT (bbs, i, bb) |
66f97d31 ZD |
1335 | { |
1336 | /* If the dominance tree is conservatively correct, split it now. */ | |
1337 | if (conservative) | |
1338 | set_immediate_dominator (CDI_DOMINATORS, bb, NULL); | |
1eb68d2d | 1339 | map.put (bb, i); |
66f97d31 | 1340 | } |
1eb68d2d | 1341 | map.put (ENTRY_BLOCK_PTR_FOR_FN (cfun), n); |
66f97d31 ZD |
1342 | |
1343 | g = new_graph (n + 1); | |
1344 | for (y = 0; y < g->n_vertices; y++) | |
1345 | g->vertices[y].data = BITMAP_ALLOC (NULL); | |
9771b263 | 1346 | FOR_EACH_VEC_ELT (bbs, i, bb) |
66f97d31 ZD |
1347 | { |
1348 | FOR_EACH_EDGE (e, ei, bb->preds) | |
355be0dc | 1349 | { |
66f97d31 ZD |
1350 | dom = root_of_dom_tree (CDI_DOMINATORS, e->src); |
1351 | if (dom == bb) | |
1352 | continue; | |
1353 | ||
1eb68d2d | 1354 | dom_i = *map.get (dom); |
66f97d31 ZD |
1355 | |
1356 | /* Do not include parallel edges to G. */ | |
fcaa4ca4 | 1357 | if (!bitmap_set_bit ((bitmap) g->vertices[dom_i].data, i)) |
66f97d31 ZD |
1358 | continue; |
1359 | ||
66f97d31 | 1360 | add_edge (g, dom_i, i); |
f8032688 MM |
1361 | } |
1362 | } | |
66f97d31 ZD |
1363 | for (y = 0; y < g->n_vertices; y++) |
1364 | BITMAP_FREE (g->vertices[y].data); | |
66f97d31 ZD |
1365 | |
1366 | /* Find the dominator tree of G. */ | |
1367 | son = XNEWVEC (int, n + 1); | |
1368 | brother = XNEWVEC (int, n + 1); | |
1369 | parent = XNEWVEC (int, n + 1); | |
1370 | graphds_domtree (g, n, parent, son, brother); | |
1371 | ||
1372 | /* Finally, traverse the tree and find the immediate dominators. */ | |
1373 | for (y = n; son[y] != -1; y = son[y]) | |
1374 | continue; | |
1375 | while (y != -1) | |
1376 | { | |
1377 | determine_dominators_for_sons (g, bbs, y, son, brother); | |
1378 | ||
1379 | if (brother[y] != -1) | |
1380 | { | |
1381 | y = brother[y]; | |
1382 | while (son[y] != -1) | |
1383 | y = son[y]; | |
1384 | } | |
1385 | else | |
1386 | y = parent[y]; | |
1387 | } | |
1388 | ||
1389 | free (son); | |
1390 | free (brother); | |
1391 | free (parent); | |
e7bd94cc | 1392 | |
66f97d31 | 1393 | free_graph (g); |
355be0dc | 1394 | } |
f8032688 | 1395 | |
355be0dc | 1396 | void |
d47cc544 | 1397 | add_to_dominance_info (enum cdi_direction dir, basic_block bb) |
355be0dc | 1398 | { |
2b28c07a JC |
1399 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1400 | ||
2ba31c05 | 1401 | gcc_checking_assert (dom_computed[dir_index] && !bb->dom[dir_index]); |
d47cc544 | 1402 | |
2b28c07a | 1403 | n_bbs_in_dom_tree[dir_index]++; |
b8698a0f | 1404 | |
2b28c07a | 1405 | bb->dom[dir_index] = et_new_tree (bb); |
d47cc544 | 1406 | |
2b28c07a JC |
1407 | if (dom_computed[dir_index] == DOM_OK) |
1408 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
355be0dc JH |
1409 | } |
1410 | ||
1411 | void | |
d47cc544 SB |
1412 | delete_from_dominance_info (enum cdi_direction dir, basic_block bb) |
1413 | { | |
2b28c07a | 1414 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
d47cc544 | 1415 | |
2ba31c05 | 1416 | gcc_checking_assert (dom_computed[dir_index]); |
d47cc544 | 1417 | |
2b28c07a JC |
1418 | et_free_tree (bb->dom[dir_index]); |
1419 | bb->dom[dir_index] = NULL; | |
1420 | n_bbs_in_dom_tree[dir_index]--; | |
1421 | ||
1422 | if (dom_computed[dir_index] == DOM_OK) | |
1423 | dom_computed[dir_index] = DOM_NO_FAST_QUERY; | |
d47cc544 SB |
1424 | } |
1425 | ||
1426 | /* Returns the first son of BB in the dominator or postdominator tree | |
1427 | as determined by DIR. */ | |
1428 | ||
1429 | basic_block | |
1430 | first_dom_son (enum cdi_direction dir, basic_block bb) | |
355be0dc | 1431 | { |
2b28c07a JC |
1432 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1433 | struct et_node *son = bb->dom[dir_index]->son; | |
d47cc544 | 1434 | |
f883e0a7 | 1435 | return (basic_block) (son ? son->data : NULL); |
d47cc544 SB |
1436 | } |
1437 | ||
1438 | /* Returns the next dominance son after BB in the dominator or postdominator | |
1439 | tree as determined by DIR, or NULL if it was the last one. */ | |
1440 | ||
1441 | basic_block | |
1442 | next_dom_son (enum cdi_direction dir, basic_block bb) | |
1443 | { | |
2b28c07a JC |
1444 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
1445 | struct et_node *next = bb->dom[dir_index]->right; | |
d47cc544 | 1446 | |
f883e0a7 | 1447 | return (basic_block) (next->father->son == next ? NULL : next->data); |
355be0dc JH |
1448 | } |
1449 | ||
2b28c07a JC |
1450 | /* Return dominance availability for dominance info DIR. */ |
1451 | ||
1452 | enum dom_state | |
e3f613cb | 1453 | dom_info_state (function *fn, enum cdi_direction dir) |
2b28c07a | 1454 | { |
e3f613cb RB |
1455 | if (!fn->cfg) |
1456 | return DOM_NONE; | |
1457 | ||
2b28c07a | 1458 | unsigned int dir_index = dom_convert_dir_to_idx (dir); |
e3f613cb RB |
1459 | return fn->cfg->x_dom_computed[dir_index]; |
1460 | } | |
2b28c07a | 1461 | |
e3f613cb RB |
1462 | enum dom_state |
1463 | dom_info_state (enum cdi_direction dir) | |
1464 | { | |
1465 | return dom_info_state (cfun, dir); | |
2b28c07a JC |
1466 | } |
1467 | ||
1468 | /* Set the dominance availability for dominance info DIR to NEW_STATE. */ | |
1469 | ||
1470 | void | |
1471 | set_dom_info_availability (enum cdi_direction dir, enum dom_state new_state) | |
1472 | { | |
1473 | unsigned int dir_index = dom_convert_dir_to_idx (dir); | |
1474 | ||
1475 | dom_computed[dir_index] = new_state; | |
1476 | } | |
1477 | ||
fce22de5 ZD |
1478 | /* Returns true if dominance information for direction DIR is available. */ |
1479 | ||
1480 | bool | |
e3f613cb | 1481 | dom_info_available_p (function *fn, enum cdi_direction dir) |
fce22de5 | 1482 | { |
e3f613cb RB |
1483 | return dom_info_state (fn, dir) != DOM_NONE; |
1484 | } | |
2b28c07a | 1485 | |
e3f613cb RB |
1486 | bool |
1487 | dom_info_available_p (enum cdi_direction dir) | |
1488 | { | |
1489 | return dom_info_available_p (cfun, dir); | |
fce22de5 ZD |
1490 | } |
1491 | ||
24e47c76 | 1492 | DEBUG_FUNCTION void |
d47cc544 | 1493 | debug_dominance_info (enum cdi_direction dir) |
355be0dc JH |
1494 | { |
1495 | basic_block bb, bb2; | |
11cd3bed | 1496 | FOR_EACH_BB_FN (bb, cfun) |
d47cc544 | 1497 | if ((bb2 = get_immediate_dominator (dir, bb))) |
355be0dc | 1498 | fprintf (stderr, "%i %i\n", bb->index, bb2->index); |
f8032688 | 1499 | } |
1fc3998d ZD |
1500 | |
1501 | /* Prints to stderr representation of the dominance tree (for direction DIR) | |
cea618ac | 1502 | rooted in ROOT, indented by INDENT tabulators. If INDENT_FIRST is false, |
1fc3998d ZD |
1503 | the first line of the output is not indented. */ |
1504 | ||
1505 | static void | |
1506 | debug_dominance_tree_1 (enum cdi_direction dir, basic_block root, | |
1507 | unsigned indent, bool indent_first) | |
1508 | { | |
1509 | basic_block son; | |
1510 | unsigned i; | |
1511 | bool first = true; | |
1512 | ||
1513 | if (indent_first) | |
1514 | for (i = 0; i < indent; i++) | |
1515 | fprintf (stderr, "\t"); | |
1516 | fprintf (stderr, "%d\t", root->index); | |
1517 | ||
1518 | for (son = first_dom_son (dir, root); | |
1519 | son; | |
1520 | son = next_dom_son (dir, son)) | |
1521 | { | |
1522 | debug_dominance_tree_1 (dir, son, indent + 1, !first); | |
1523 | first = false; | |
1524 | } | |
1525 | ||
1526 | if (first) | |
1527 | fprintf (stderr, "\n"); | |
1528 | } | |
1529 | ||
1530 | /* Prints to stderr representation of the dominance tree (for direction DIR) | |
1531 | rooted in ROOT. */ | |
1532 | ||
24e47c76 | 1533 | DEBUG_FUNCTION void |
1fc3998d ZD |
1534 | debug_dominance_tree (enum cdi_direction dir, basic_block root) |
1535 | { | |
1536 | debug_dominance_tree_1 (dir, root, 0, false); | |
1537 | } |