Bug Summary

File:polly/lib/External/isl/isl_scan.c
Warning:line 117, column 3
Value stored to 'bset' is never read

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name isl_scan.c -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/polly/lib/External -resource-dir /usr/lib/llvm-14/lib/clang/14.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/polly/lib/External -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/polly/lib/External -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/polly/lib/External/isl -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/polly/lib/External/isl/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/polly/lib/External/isl/imath -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/polly/lib/External/isl -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/polly/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/polly/lib/External/pet/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/polly/lib/External/isl/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/polly/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/include -I /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/llvm/include -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/llvm-14/lib/clang/14.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-comment -std=gnu99 -fconst-strings -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/build-llvm/tools/polly/lib/External -fdebug-prefix-map=/build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0=. -ferror-limit 19 -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-08-28-193554-24367-1 -x c /build/llvm-toolchain-snapshot-14~++20210828111110+16086d47c0d0/polly/lib/External/isl/isl_scan.c
1/*
2 * Copyright 2008-2009 Katholieke Universiteit Leuven
3 *
4 * Use of this software is governed by the MIT license
5 *
6 * Written by Sven Verdoolaege, K.U.Leuven, Departement
7 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
8 */
9
10#include <isl_ctx_private.h>
11#include <isl_map_private.h>
12#include "isl_basis_reduction.h"
13#include "isl_scan.h"
14#include <isl_seq.h>
15#include "isl_tab.h"
16#include <isl_val_private.h>
17#include <isl_vec_private.h>
18
19struct isl_counter {
20 struct isl_scan_callback callback;
21 isl_int count;
22 isl_int max;
23};
24
25static isl_stat increment_counter(struct isl_scan_callback *cb,
26 __isl_take isl_vec *sample)
27{
28 struct isl_counter *cnt = (struct isl_counter *)cb;
29
30 isl_int_add_ui(cnt->count, cnt->count, 1)isl_sioimath_add_ui((cnt->count), *(cnt->count), 1);
31
32 isl_vec_free(sample);
33
34 if (isl_int_is_zero(cnt->max)(isl_sioimath_sgn(*(cnt->max)) == 0) || isl_int_lt(cnt->count, cnt->max)(isl_sioimath_cmp(*(cnt->count), *(cnt->max)) < 0))
35 return isl_stat_ok;
36 return isl_stat_error;
37}
38
39static int increment_range(struct isl_scan_callback *cb, isl_int min, isl_int max)
40{
41 struct isl_counter *cnt = (struct isl_counter *)cb;
42
43 isl_int_add(cnt->count, cnt->count, max)isl_sioimath_add((cnt->count), *(cnt->count), *(max));
44 isl_int_sub(cnt->count, cnt->count, min)isl_sioimath_sub((cnt->count), *(cnt->count), *(min));
45 isl_int_add_ui(cnt->count, cnt->count, 1)isl_sioimath_add_ui((cnt->count), *(cnt->count), 1);
46
47 if (isl_int_is_zero(cnt->max)(isl_sioimath_sgn(*(cnt->max)) == 0) || isl_int_lt(cnt->count, cnt->max)(isl_sioimath_cmp(*(cnt->count), *(cnt->max)) < 0))
48 return 0;
49 isl_int_set(cnt->count, cnt->max)isl_sioimath_set((cnt->count), *(cnt->max));
50 return -1;
51}
52
53/* Call callback->add with the current sample value of the tableau "tab".
54 */
55static int add_solution(struct isl_tab *tab, struct isl_scan_callback *callback)
56{
57 struct isl_vec *sample;
58
59 if (!tab)
60 return -1;
61 sample = isl_tab_get_sample_value(tab);
62 if (!sample)
63 return -1;
64
65 return callback->add(callback, sample);
66}
67
68static isl_stat scan_0D(__isl_take isl_basic_setisl_basic_map *bset,
69 struct isl_scan_callback *callback)
70{
71 struct isl_vec *sample;
72
73 sample = isl_vec_alloc(bset->ctx, 1);
74 isl_basic_set_free(bset);
75
76 if (!sample)
77 return isl_stat_error;
78
79 isl_int_set_si(sample->el[0], 1)isl_sioimath_set_si((sample->el[0]), 1);
80
81 return callback->add(callback, sample);
82}
83
84/* Look for all integer points in "bset", which is assumed to be bounded,
85 * and call callback->add on each of them.
86 *
87 * We first compute a reduced basis for the set and then scan
88 * the set in the directions of this basis.
89 * We basically perform a depth first search, where in each level i
90 * we compute the range in the i-th basis vector direction, given
91 * fixed values in the directions of the previous basis vector.
92 * We then add an equality to the tableau fixing the value in the
93 * direction of the current basis vector to each value in the range
94 * in turn and then continue to the next level.
95 *
96 * The search is implemented iteratively. "level" identifies the current
97 * basis vector. "init" is true if we want the first value at the current
98 * level and false if we want the next value.
99 * Solutions are added in the leaves of the search tree, i.e., after
100 * we have fixed a value in each direction of the basis.
101 */
102isl_stat isl_basic_set_scan(__isl_take isl_basic_setisl_basic_map *bset,
103 struct isl_scan_callback *callback)
104{
105 isl_size dim;
106 struct isl_mat *B = NULL((void*)0);
107 struct isl_tab *tab = NULL((void*)0);
108 struct isl_vec *min;
109 struct isl_vec *max;
110 struct isl_tab_undo **snap;
111 int level;
112 int init;
113 enum isl_lp_result res;
114
115 dim = isl_basic_set_dim(bset, isl_dim_all);
116 if (dim < 0) {
117 bset = isl_basic_set_free(bset);
Value stored to 'bset' is never read
118 return isl_stat_error;
119 }
120
121 if (dim == 0)
122 return scan_0D(bset, callback);
123
124 min = isl_vec_alloc(bset->ctx, dim);
125 max = isl_vec_alloc(bset->ctx, dim);
126 snap = isl_alloc_array(bset->ctx, struct isl_tab_undo *, dim)((struct isl_tab_undo * *)isl_malloc_or_die(bset->ctx, (dim
)*sizeof(struct isl_tab_undo *)));
127
128 if (!min || !max || !snap)
129 goto error;
130
131 tab = isl_tab_from_basic_set(bset, 0);
132 if (!tab)
133 goto error;
134 if (isl_tab_extend_cons(tab, dim + 1) < 0)
135 goto error;
136
137 tab->basis = isl_mat_identity(bset->ctx, 1 + dim);
138 if (1)
139 tab = isl_tab_compute_reduced_basis(tab);
140 if (!tab)
141 goto error;
142 B = isl_mat_copy(tab->basis);
143 if (!B)
144 goto error;
145
146 level = 0;
147 init = 1;
148
149 while (level >= 0) {
150 int empty = 0;
151 if (init) {
152 res = isl_tab_min(tab, B->row[1 + level],
153 bset->ctx->one, &min->el[level], NULL((void*)0), 0);
154 if (res == isl_lp_empty)
155 empty = 1;
156 if (res == isl_lp_error || res == isl_lp_unbounded)
157 goto error;
158 isl_seq_neg(B->row[1 + level] + 1,
159 B->row[1 + level] + 1, dim);
160 res = isl_tab_min(tab, B->row[1 + level],
161 bset->ctx->one, &max->el[level], NULL((void*)0), 0);
162 isl_seq_neg(B->row[1 + level] + 1,
163 B->row[1 + level] + 1, dim);
164 isl_int_neg(max->el[level], max->el[level])isl_sioimath_neg((max->el[level]), *(max->el[level]));
165 if (res == isl_lp_empty)
166 empty = 1;
167 if (res == isl_lp_error || res == isl_lp_unbounded)
168 goto error;
169 snap[level] = isl_tab_snap(tab);
170 } else
171 isl_int_add_ui(min->el[level], min->el[level], 1)isl_sioimath_add_ui((min->el[level]), *(min->el[level])
, 1);
172
173 if (empty || isl_int_gt(min->el[level], max->el[level])(isl_sioimath_cmp(*(min->el[level]), *(max->el[level]))
> 0)) {
174 level--;
175 init = 0;
176 if (level >= 0)
177 if (isl_tab_rollback(tab, snap[level]) < 0)
178 goto error;
179 continue;
180 }
181 if (level == dim - 1 && callback->add == increment_counter) {
182 if (increment_range(callback,
183 min->el[level], max->el[level]))
184 goto error;
185 level--;
186 init = 0;
187 if (level >= 0)
188 if (isl_tab_rollback(tab, snap[level]) < 0)
189 goto error;
190 continue;
191 }
192 isl_int_neg(B->row[1 + level][0], min->el[level])isl_sioimath_neg((B->row[1 + level][0]), *(min->el[level
]));
193 if (isl_tab_add_valid_eq(tab, B->row[1 + level]) < 0)
194 goto error;
195 isl_int_set_si(B->row[1 + level][0], 0)isl_sioimath_set_si((B->row[1 + level][0]), 0);
196 if (level < dim - 1) {
197 ++level;
198 init = 1;
199 continue;
200 }
201 if (add_solution(tab, callback) < 0)
202 goto error;
203 init = 0;
204 if (isl_tab_rollback(tab, snap[level]) < 0)
205 goto error;
206 }
207
208 isl_tab_free(tab);
209 free(snap);
210 isl_vec_free(min);
211 isl_vec_free(max);
212 isl_basic_set_free(bset);
213 isl_mat_free(B);
214 return isl_stat_ok;
215error:
216 isl_tab_free(tab);
217 free(snap);
218 isl_vec_free(min);
219 isl_vec_free(max);
220 isl_basic_set_free(bset);
221 isl_mat_free(B);
222 return isl_stat_error;
223}
224
225isl_stat isl_set_scan(__isl_take isl_setisl_map *set,
226 struct isl_scan_callback *callback)
227{
228 int i;
229
230 if (!set || !callback)
231 goto error;
232
233 set = isl_set_cow(set);
234 set = isl_set_make_disjoint(set);
235 set = isl_set_compute_divs(set);
236 if (!set)
237 goto error;
238
239 for (i = 0; i < set->n; ++i)
240 if (isl_basic_set_scan(isl_basic_set_copy(set->p[i]),
241 callback) < 0)
242 goto error;
243
244 isl_set_free(set);
245 return isl_stat_ok;
246error:
247 isl_set_free(set);
248 return isl_stat_error;
249}
250
251int isl_basic_set_count_upto(__isl_keep isl_basic_setisl_basic_map *bset,
252 isl_int max, isl_int *count)
253{
254 struct isl_counter cnt = { { &increment_counter } };
255
256 if (!bset)
257 return -1;
258
259 isl_int_init(cnt.count)isl_sioimath_init((cnt.count));
260 isl_int_init(cnt.max)isl_sioimath_init((cnt.max));
261
262 isl_int_set_si(cnt.count, 0)isl_sioimath_set_si((cnt.count), 0);
263 isl_int_set(cnt.max, max)isl_sioimath_set((cnt.max), *(max));
264 if (isl_basic_set_scan(isl_basic_set_copy(bset), &cnt.callback) < 0 &&
265 isl_int_lt(cnt.count, cnt.max)(isl_sioimath_cmp(*(cnt.count), *(cnt.max)) < 0))
266 goto error;
267
268 isl_int_set(*count, cnt.count)isl_sioimath_set((*count), *(cnt.count));
269 isl_int_clear(cnt.max)isl_sioimath_clear((cnt.max));
270 isl_int_clear(cnt.count)isl_sioimath_clear((cnt.count));
271
272 return 0;
273error:
274 isl_int_clear(cnt.count)isl_sioimath_clear((cnt.count));
275 return -1;
276}
277
278int isl_set_count_upto(__isl_keep isl_setisl_map *set, isl_int max, isl_int *count)
279{
280 struct isl_counter cnt = { { &increment_counter } };
281
282 if (!set)
283 return -1;
284
285 isl_int_init(cnt.count)isl_sioimath_init((cnt.count));
286 isl_int_init(cnt.max)isl_sioimath_init((cnt.max));
287
288 isl_int_set_si(cnt.count, 0)isl_sioimath_set_si((cnt.count), 0);
289 isl_int_set(cnt.max, max)isl_sioimath_set((cnt.max), *(max));
290 if (isl_set_scan(isl_set_copy(set), &cnt.callback) < 0 &&
291 isl_int_lt(cnt.count, cnt.max)(isl_sioimath_cmp(*(cnt.count), *(cnt.max)) < 0))
292 goto error;
293
294 isl_int_set(*count, cnt.count)isl_sioimath_set((*count), *(cnt.count));
295 isl_int_clear(cnt.max)isl_sioimath_clear((cnt.max));
296 isl_int_clear(cnt.count)isl_sioimath_clear((cnt.count));
297
298 return 0;
299error:
300 isl_int_clear(cnt.count)isl_sioimath_clear((cnt.count));
301 return -1;
302}
303
304int isl_set_count(__isl_keep isl_setisl_map *set, isl_int *count)
305{
306 if (!set)
307 return -1;
308 return isl_set_count_upto(set, set->ctx->zero, count);
309}
310
311/* Count the total number of elements in "set" (in an inefficient way) and
312 * return the result.
313 */
314__isl_give isl_val *isl_set_count_val(__isl_keep isl_setisl_map *set)
315{
316 isl_val *v;
317
318 if (!set)
319 return NULL((void*)0);
320 v = isl_val_zero(isl_set_get_ctx(set));
321 v = isl_val_cow(v);
322 if (!v)
323 return NULL((void*)0);
324 if (isl_set_count(set, &v->n) < 0)
325 v = isl_val_free(v);
326 return v;
327}