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981db194 | 1 | /* SparseSet implementation. |
fbd26352 | 2 | Copyright (C) 2007-2019 Free Software Foundation, Inc. |
981db194 | 3 | Contributed by Peter Bergner <bergner@vnet.ibm.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify it under | |
8 | the terms of the GNU General Public License as published by the Free | |
9 | Software Foundation; either version 3, or (at your option) any later | |
10 | version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
13 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
14 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
15 | for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
3304ca2b | 21 | #include "config.h" |
22 | #include "system.h" | |
981db194 | 23 | #include "sparseset.h" |
24 | ||
981db194 | 25 | /* Allocate and clear a n_elms SparseSet. */ |
26 | ||
27 | sparseset | |
28 | sparseset_alloc (SPARSESET_ELT_TYPE n_elms) | |
29 | { | |
30 | unsigned int n_bytes = sizeof (struct sparseset_def) | |
31 | + ((n_elms - 1) * 2 * sizeof (SPARSESET_ELT_TYPE)); | |
32 | ||
9af5ce0c | 33 | sparseset set = XNEWVAR (struct sparseset_def, n_bytes); |
a353bc75 | 34 | |
35 | /* Mark the sparseset as defined to silence some valgrind uninitialized | |
2379ccd9 | 36 | read errors when accessing set->sparse[n] when "n" is not, and never has |
37 | been, in the set. These uninitialized reads are expected, by design and | |
a353bc75 | 38 | harmless. */ |
39 | VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (set, n_bytes)); | |
40 | ||
981db194 | 41 | set->dense = &(set->elms[0]); |
42 | set->sparse = &(set->elms[n_elms]); | |
43 | set->size = n_elms; | |
44 | sparseset_clear (set); | |
45 | return set; | |
46 | } | |
47 | ||
48 | /* Low level routine not meant for use outside of sparseset.[ch]. | |
49 | Assumes idx1 < s->members and idx2 < s->members. */ | |
50 | ||
51 | static inline void | |
52 | sparseset_swap (sparseset s, SPARSESET_ELT_TYPE idx1, SPARSESET_ELT_TYPE idx2) | |
53 | { | |
54 | SPARSESET_ELT_TYPE tmp = s->dense[idx2]; | |
55 | sparseset_insert_bit (s, s->dense[idx1], idx2); | |
56 | sparseset_insert_bit (s, tmp, idx1); | |
57 | } | |
58 | ||
59 | /* Operation: S = S - {e} | |
60 | Delete e from the set S if it is a member of S. */ | |
61 | ||
62 | void | |
63 | sparseset_clear_bit (sparseset s, SPARSESET_ELT_TYPE e) | |
64 | { | |
65 | if (sparseset_bit_p (s, e)) | |
66 | { | |
67 | SPARSESET_ELT_TYPE idx = s->sparse[e]; | |
68 | SPARSESET_ELT_TYPE iter = s->iter; | |
69 | SPARSESET_ELT_TYPE mem = s->members - 1; | |
70 | ||
71 | /* If we are iterating over this set and we want to delete a | |
72 | member we've already visited, then we swap the element we | |
73 | want to delete with the element at the current iteration | |
74 | index so that it plays well together with the code below | |
75 | that actually removes the element. */ | |
76 | if (s->iterating && idx <= iter) | |
77 | { | |
78 | if (idx < iter) | |
79 | { | |
80 | sparseset_swap (s, idx, iter); | |
81 | idx = iter; | |
82 | } | |
83 | s->iter_inc = 0; | |
84 | } | |
85 | ||
86 | /* Replace the element we want to delete with the last element | |
87 | in the dense array and then decrement s->members, effectively | |
88 | removing the element we want to delete. */ | |
89 | sparseset_insert_bit (s, s->dense[mem], idx); | |
90 | s->members = mem; | |
91 | } | |
92 | } | |
93 | ||
94 | /* Operation: D = S | |
95 | Restrictions: none. */ | |
96 | ||
97 | void | |
98 | sparseset_copy (sparseset d, sparseset s) | |
99 | { | |
100 | SPARSESET_ELT_TYPE i; | |
101 | ||
102 | if (d == s) | |
103 | return; | |
104 | ||
105 | sparseset_clear (d); | |
106 | for (i = 0; i < s->members; i++) | |
107 | sparseset_insert_bit (d, s->dense[i], i); | |
108 | d->members = s->members; | |
109 | } | |
110 | ||
111 | /* Operation: D = A & B. | |
112 | Restrictions: none. */ | |
113 | ||
114 | void | |
115 | sparseset_and (sparseset d, sparseset a, sparseset b) | |
116 | { | |
117 | SPARSESET_ELT_TYPE e; | |
118 | ||
119 | if (a == b) | |
120 | { | |
121 | if (d != a) | |
122 | sparseset_copy (d, a); | |
123 | return; | |
124 | } | |
125 | ||
126 | if (d == a || d == b) | |
127 | { | |
128 | sparseset s = (d == a) ? b : a; | |
129 | ||
130 | EXECUTE_IF_SET_IN_SPARSESET (d, e) | |
131 | if (!sparseset_bit_p (s, e)) | |
132 | sparseset_clear_bit (d, e); | |
133 | } | |
134 | else | |
135 | { | |
136 | sparseset sml, lrg; | |
137 | ||
138 | if (sparseset_cardinality (a) < sparseset_cardinality (b)) | |
139 | { | |
140 | sml = a; | |
141 | lrg = b; | |
142 | } | |
143 | else | |
144 | { | |
145 | sml = b; | |
146 | lrg = a; | |
147 | } | |
148 | ||
149 | sparseset_clear (d); | |
150 | EXECUTE_IF_SET_IN_SPARSESET (sml, e) | |
151 | if (sparseset_bit_p (lrg, e)) | |
152 | sparseset_set_bit (d, e); | |
153 | } | |
154 | } | |
155 | ||
156 | /* Operation: D = A & ~B. | |
157 | Restrictions: D != B, unless D == A == B. */ | |
158 | ||
159 | void | |
160 | sparseset_and_compl (sparseset d, sparseset a, sparseset b) | |
161 | { | |
162 | SPARSESET_ELT_TYPE e; | |
163 | ||
164 | if (a == b) | |
165 | { | |
166 | sparseset_clear (d); | |
167 | return; | |
168 | } | |
169 | ||
170 | gcc_assert (d != b); | |
171 | ||
172 | if (d == a) | |
173 | { | |
174 | if (sparseset_cardinality (d) < sparseset_cardinality (b)) | |
175 | { | |
176 | EXECUTE_IF_SET_IN_SPARSESET (d, e) | |
177 | if (sparseset_bit_p (b, e)) | |
178 | sparseset_clear_bit (d, e); | |
179 | } | |
180 | else | |
181 | { | |
182 | EXECUTE_IF_SET_IN_SPARSESET (b, e) | |
183 | sparseset_clear_bit (d, e); | |
184 | } | |
185 | } | |
186 | else | |
187 | { | |
188 | sparseset_clear (d); | |
189 | EXECUTE_IF_SET_IN_SPARSESET (a, e) | |
190 | if (!sparseset_bit_p (b, e)) | |
191 | sparseset_set_bit (d, e); | |
192 | } | |
193 | } | |
194 | ||
195 | /* Operation: D = A | B. | |
196 | Restrictions: none. */ | |
197 | ||
198 | void | |
199 | sparseset_ior (sparseset d, sparseset a, sparseset b) | |
200 | { | |
201 | SPARSESET_ELT_TYPE e; | |
202 | ||
203 | if (a == b) | |
204 | sparseset_copy (d, a); | |
205 | else if (d == b) | |
206 | { | |
207 | EXECUTE_IF_SET_IN_SPARSESET (a, e) | |
208 | sparseset_set_bit (d, e); | |
209 | } | |
210 | else | |
211 | { | |
212 | if (d != a) | |
213 | sparseset_copy (d, a); | |
214 | EXECUTE_IF_SET_IN_SPARSESET (b, e) | |
215 | sparseset_set_bit (d, e); | |
216 | } | |
217 | } | |
218 | ||
219 | /* Operation: A == B | |
220 | Restrictions: none. */ | |
221 | ||
222 | bool | |
223 | sparseset_equal_p (sparseset a, sparseset b) | |
224 | { | |
225 | SPARSESET_ELT_TYPE e; | |
226 | ||
227 | if (a == b) | |
228 | return true; | |
229 | ||
230 | if (sparseset_cardinality (a) != sparseset_cardinality (b)) | |
231 | return false; | |
232 | ||
233 | EXECUTE_IF_SET_IN_SPARSESET (a, e) | |
234 | if (!sparseset_bit_p (b, e)) | |
235 | return false; | |
236 | ||
237 | return true; | |
238 | } | |
239 |