Bug Summary

File:polly/lib/External/isl/isl_sample.c
Warning:line 1144, column 2
Value stored to 'ctx' is never read

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name isl_sample.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 -mthread-model posix -mframe-pointer=none -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-11/lib/clang/11.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/polly/lib/External -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/pet/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/ppcg/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/ppcg/imath -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/polly/lib/External/ppcg -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/imath -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/polly/lib/External/isl -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/polly/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/tools/polly/lib/External/isl/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include -U NDEBUG -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-11/lib/clang/11.0.0/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-11~++20200309111110+2c36c23f347/build-llvm/tools/polly/lib/External -fdebug-prefix-map=/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347=. -ferror-limit 19 -fmessage-length 0 -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2020-03-09-184146-41876-1 -x c /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.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_sample.h"
13#include <isl/vec.h>
14#include <isl/mat.h>
15#include <isl_seq.h>
16#include "isl_equalities.h"
17#include "isl_tab.h"
18#include "isl_basis_reduction.h"
19#include <isl_factorization.h>
20#include <isl_point_private.h>
21#include <isl_options_private.h>
22#include <isl_vec_private.h>
23
24#include <bset_from_bmap.c>
25#include <set_to_map.c>
26
27static __isl_give isl_vec *empty_sample(__isl_take isl_basic_setisl_basic_map *bset)
28{
29 struct isl_vec *vec;
30
31 vec = isl_vec_alloc(bset->ctx, 0);
32 isl_basic_set_free(bset);
33 return vec;
34}
35
36/* Construct a zero sample of the same dimension as bset.
37 * As a special case, if bset is zero-dimensional, this
38 * function creates a zero-dimensional sample point.
39 */
40static __isl_give isl_vec *zero_sample(__isl_take isl_basic_setisl_basic_map *bset)
41{
42 isl_size dim;
43 struct isl_vec *sample;
44
45 dim = isl_basic_set_dim(bset, isl_dim_all);
46 if (dim < 0)
47 goto error;
48 sample = isl_vec_alloc(bset->ctx, 1 + dim);
49 if (sample) {
50 isl_int_set_si(sample->el[0], 1)isl_sioimath_set_si((sample->el[0]), 1);
51 isl_seq_clr(sample->el + 1, dim);
52 }
53 isl_basic_set_free(bset);
54 return sample;
55error:
56 isl_basic_set_free(bset);
57 return NULL((void*)0);
58}
59
60static __isl_give isl_vec *interval_sample(__isl_take isl_basic_setisl_basic_map *bset)
61{
62 int i;
63 isl_int t;
64 struct isl_vec *sample;
65
66 bset = isl_basic_set_simplify(bset);
67 if (!bset)
68 return NULL((void*)0);
69 if (isl_basic_set_plain_is_empty(bset))
70 return empty_sample(bset);
71 if (bset->n_eq == 0 && bset->n_ineq == 0)
72 return zero_sample(bset);
73
74 sample = isl_vec_alloc(bset->ctx, 2);
75 if (!sample)
76 goto error;
77 if (!bset)
78 return NULL((void*)0);
79 isl_int_set_si(sample->block.data[0], 1)isl_sioimath_set_si((sample->block.data[0]), 1);
80
81 if (bset->n_eq > 0) {
82 isl_assert(bset->ctx, bset->n_eq == 1, goto error)do { if (bset->n_eq == 1) break; do { isl_handle_error(bset
->ctx, isl_error_unknown, "Assertion \"" "bset->n_eq == 1"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 82); goto error; } while (0); } while (0)
;
83 isl_assert(bset->ctx, bset->n_ineq == 0, goto error)do { if (bset->n_ineq == 0) break; do { isl_handle_error(bset
->ctx, isl_error_unknown, "Assertion \"" "bset->n_ineq == 0"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 83); goto error; } while (0); } while (0)
;
84 if (isl_int_is_one(bset->eq[0][1])(isl_sioimath_cmp_si(*(bset->eq[0][1]), 1) == 0))
85 isl_int_neg(sample->el[1], bset->eq[0][0])isl_sioimath_neg((sample->el[1]), *(bset->eq[0][0]));
86 else {
87 isl_assert(bset->ctx, isl_int_is_negone(bset->eq[0][1]),do { if ((isl_sioimath_cmp_si(*(bset->eq[0][1]), -1) == 0)
) break; do { isl_handle_error(bset->ctx, isl_error_unknown
, "Assertion \"" "(isl_sioimath_cmp_si(*(bset->eq[0][1]), -1) == 0)"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 88); goto error; } while (0); } while (0)
88 goto error)do { if ((isl_sioimath_cmp_si(*(bset->eq[0][1]), -1) == 0)
) break; do { isl_handle_error(bset->ctx, isl_error_unknown
, "Assertion \"" "(isl_sioimath_cmp_si(*(bset->eq[0][1]), -1) == 0)"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 88); goto error; } while (0); } while (0)
;
89 isl_int_set(sample->el[1], bset->eq[0][0])isl_sioimath_set((sample->el[1]), *(bset->eq[0][0]));
90 }
91 isl_basic_set_free(bset);
92 return sample;
93 }
94
95 isl_int_init(t)isl_sioimath_init((t));
96 if (isl_int_is_one(bset->ineq[0][1])(isl_sioimath_cmp_si(*(bset->ineq[0][1]), 1) == 0))
97 isl_int_neg(sample->block.data[1], bset->ineq[0][0])isl_sioimath_neg((sample->block.data[1]), *(bset->ineq[
0][0]))
;
98 else
99 isl_int_set(sample->block.data[1], bset->ineq[0][0])isl_sioimath_set((sample->block.data[1]), *(bset->ineq[
0][0]))
;
100 for (i = 1; i < bset->n_ineq; ++i) {
101 isl_seq_inner_product(sample->block.data,
102 bset->ineq[i], 2, &t);
103 if (isl_int_is_neg(t)(isl_sioimath_sgn(*(t)) < 0))
104 break;
105 }
106 isl_int_clear(t)isl_sioimath_clear((t));
107 if (i < bset->n_ineq) {
108 isl_vec_free(sample);
109 return empty_sample(bset);
110 }
111
112 isl_basic_set_free(bset);
113 return sample;
114error:
115 isl_basic_set_free(bset);
116 isl_vec_free(sample);
117 return NULL((void*)0);
118}
119
120/* Find a sample integer point, if any, in bset, which is known
121 * to have equalities. If bset contains no integer points, then
122 * return a zero-length vector.
123 * We simply remove the known equalities, compute a sample
124 * in the resulting bset, using the specified recurse function,
125 * and then transform the sample back to the original space.
126 */
127static __isl_give isl_vec *sample_eq(__isl_take isl_basic_setisl_basic_map *bset,
128 __isl_give isl_vec *(*recurse)(__isl_take isl_basic_setisl_basic_map *))
129{
130 struct isl_mat *T;
131 struct isl_vec *sample;
132
133 if (!bset)
134 return NULL((void*)0);
135
136 bset = isl_basic_set_remove_equalities(bset, &T, NULL((void*)0));
137 sample = recurse(bset);
138 if (!sample || sample->size == 0)
139 isl_mat_free(T);
140 else
141 sample = isl_mat_vec_product(T, sample);
142 return sample;
143}
144
145/* Return a matrix containing the equalities of the tableau
146 * in constraint form. The tableau is assumed to have
147 * an associated bset that has been kept up-to-date.
148 */
149static struct isl_mat *tab_equalities(struct isl_tab *tab)
150{
151 int i, j;
152 int n_eq;
153 struct isl_mat *eq;
154 struct isl_basic_setisl_basic_map *bset;
155
156 if (!tab)
157 return NULL((void*)0);
158
159 bset = isl_tab_peek_bset(tab);
160 isl_assert(tab->mat->ctx, bset, return NULL)do { if (bset) break; do { isl_handle_error(tab->mat->ctx
, isl_error_unknown, "Assertion \"" "bset" "\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 160); return ((void*)0); } while (0); } while (0)
;
161
162 n_eq = tab->n_var - tab->n_col + tab->n_dead;
163 if (tab->empty || n_eq == 0)
164 return isl_mat_alloc(tab->mat->ctx, 0, tab->n_var);
165 if (n_eq == tab->n_var)
166 return isl_mat_identity(tab->mat->ctx, tab->n_var);
167
168 eq = isl_mat_alloc(tab->mat->ctx, n_eq, tab->n_var);
169 if (!eq)
170 return NULL((void*)0);
171 for (i = 0, j = 0; i < tab->n_con; ++i) {
172 if (tab->con[i].is_row)
173 continue;
174 if (tab->con[i].index >= 0 && tab->con[i].index >= tab->n_dead)
175 continue;
176 if (i < bset->n_eq)
177 isl_seq_cpy(eq->row[j], bset->eq[i] + 1, tab->n_var);
178 else
179 isl_seq_cpy(eq->row[j],
180 bset->ineq[i - bset->n_eq] + 1, tab->n_var);
181 ++j;
182 }
183 isl_assert(bset->ctx, j == n_eq, goto error)do { if (j == n_eq) break; do { isl_handle_error(bset->ctx
, isl_error_unknown, "Assertion \"" "j == n_eq" "\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 183); goto error; } while (0); } while (0)
;
184 return eq;
185error:
186 isl_mat_free(eq);
187 return NULL((void*)0);
188}
189
190/* Compute and return an initial basis for the bounded tableau "tab".
191 *
192 * If the tableau is either full-dimensional or zero-dimensional,
193 * the we simply return an identity matrix.
194 * Otherwise, we construct a basis whose first directions correspond
195 * to equalities.
196 */
197static struct isl_mat *initial_basis(struct isl_tab *tab)
198{
199 int n_eq;
200 struct isl_mat *eq;
201 struct isl_mat *Q;
202
203 tab->n_unbounded = 0;
204 tab->n_zero = n_eq = tab->n_var - tab->n_col + tab->n_dead;
205 if (tab->empty || n_eq == 0 || n_eq == tab->n_var)
206 return isl_mat_identity(tab->mat->ctx, 1 + tab->n_var);
207
208 eq = tab_equalities(tab);
209 eq = isl_mat_left_hermite(eq, 0, NULL((void*)0), &Q);
210 if (!eq)
211 return NULL((void*)0);
212 isl_mat_free(eq);
213
214 Q = isl_mat_lin_to_aff(Q);
215 return Q;
216}
217
218/* Compute the minimum of the current ("level") basis row over "tab"
219 * and store the result in position "level" of "min".
220 *
221 * This function assumes that at least one more row and at least
222 * one more element in the constraint array are available in the tableau.
223 */
224static enum isl_lp_result compute_min(isl_ctx *ctx, struct isl_tab *tab,
225 __isl_keep isl_vec *min, int level)
226{
227 return isl_tab_min(tab, tab->basis->row[1 + level],
228 ctx->one, &min->el[level], NULL((void*)0), 0);
229}
230
231/* Compute the maximum of the current ("level") basis row over "tab"
232 * and store the result in position "level" of "max".
233 *
234 * This function assumes that at least one more row and at least
235 * one more element in the constraint array are available in the tableau.
236 */
237static enum isl_lp_result compute_max(isl_ctx *ctx, struct isl_tab *tab,
238 __isl_keep isl_vec *max, int level)
239{
240 enum isl_lp_result res;
241 unsigned dim = tab->n_var;
242
243 isl_seq_neg(tab->basis->row[1 + level] + 1,
244 tab->basis->row[1 + level] + 1, dim);
245 res = isl_tab_min(tab, tab->basis->row[1 + level],
246 ctx->one, &max->el[level], NULL((void*)0), 0);
247 isl_seq_neg(tab->basis->row[1 + level] + 1,
248 tab->basis->row[1 + level] + 1, dim);
249 isl_int_neg(max->el[level], max->el[level])isl_sioimath_neg((max->el[level]), *(max->el[level]));
250
251 return res;
252}
253
254/* Perform a greedy search for an integer point in the set represented
255 * by "tab", given that the minimal rational value (rounded up to the
256 * nearest integer) at "level" is smaller than the maximal rational
257 * value (rounded down to the nearest integer).
258 *
259 * Return 1 if we have found an integer point (if tab->n_unbounded > 0
260 * then we may have only found integer values for the bounded dimensions
261 * and it is the responsibility of the caller to extend this solution
262 * to the unbounded dimensions).
263 * Return 0 if greedy search did not result in a solution.
264 * Return -1 if some error occurred.
265 *
266 * We assign a value half-way between the minimum and the maximum
267 * to the current dimension and check if the minimal value of the
268 * next dimension is still smaller than (or equal) to the maximal value.
269 * We continue this process until either
270 * - the minimal value (rounded up) is greater than the maximal value
271 * (rounded down). In this case, greedy search has failed.
272 * - we have exhausted all bounded dimensions, meaning that we have
273 * found a solution.
274 * - the sample value of the tableau is integral.
275 * - some error has occurred.
276 */
277static int greedy_search(isl_ctx *ctx, struct isl_tab *tab,
278 __isl_keep isl_vec *min, __isl_keep isl_vec *max, int level)
279{
280 struct isl_tab_undo *snap;
281 enum isl_lp_result res;
282
283 snap = isl_tab_snap(tab);
284
285 do {
286 isl_int_add(tab->basis->row[1 + level][0],isl_sioimath_add((tab->basis->row[1 + level][0]), *(min
->el[level]), *(max->el[level]))
287 min->el[level], max->el[level])isl_sioimath_add((tab->basis->row[1 + level][0]), *(min
->el[level]), *(max->el[level]))
;
288 isl_int_fdiv_q_ui(tab->basis->row[1 + level][0],isl_sioimath_fdiv_q_ui((tab->basis->row[1 + level][0]),
*(tab->basis->row[1 + level][0]), 2)
289 tab->basis->row[1 + level][0], 2)isl_sioimath_fdiv_q_ui((tab->basis->row[1 + level][0]),
*(tab->basis->row[1 + level][0]), 2)
;
290 isl_int_neg(tab->basis->row[1 + level][0],isl_sioimath_neg((tab->basis->row[1 + level][0]), *(tab
->basis->row[1 + level][0]))
291 tab->basis->row[1 + level][0])isl_sioimath_neg((tab->basis->row[1 + level][0]), *(tab
->basis->row[1 + level][0]))
;
292 if (isl_tab_add_valid_eq(tab, tab->basis->row[1 + level]) < 0)
293 return -1;
294 isl_int_set_si(tab->basis->row[1 + level][0], 0)isl_sioimath_set_si((tab->basis->row[1 + level][0]), 0);
295
296 if (++level >= tab->n_var - tab->n_unbounded)
297 return 1;
298 if (isl_tab_sample_is_integer(tab))
299 return 1;
300
301 res = compute_min(ctx, tab, min, level);
302 if (res == isl_lp_error)
303 return -1;
304 if (res != isl_lp_ok)
305 isl_die(ctx, isl_error_internal,do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 307); return -1; } while (0)
306 "expecting bounded rational solution",do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 307); return -1; } while (0)
307 return -1)do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 307); return -1; } while (0)
;
308 res = compute_max(ctx, tab, max, level);
309 if (res == isl_lp_error)
310 return -1;
311 if (res != isl_lp_ok)
312 isl_die(ctx, isl_error_internal,do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 314); return -1; } while (0)
313 "expecting bounded rational solution",do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 314); return -1; } while (0)
314 return -1)do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 314); return -1; } while (0)
;
315 } while (isl_int_le(min->el[level], max->el[level])(isl_sioimath_cmp(*(min->el[level]), *(max->el[level]))
<= 0)
);
316
317 if (isl_tab_rollback(tab, snap) < 0)
318 return -1;
319
320 return 0;
321}
322
323/* Given a tableau representing a set, find and return
324 * an integer point in the set, if there is any.
325 *
326 * We perform a depth first search
327 * for an integer point, by scanning all possible values in the range
328 * attained by a basis vector, where an initial basis may have been set
329 * by the calling function. Otherwise an initial basis that exploits
330 * the equalities in the tableau is created.
331 * tab->n_zero is currently ignored and is clobbered by this function.
332 *
333 * The tableau is allowed to have unbounded direction, but then
334 * the calling function needs to set an initial basis, with the
335 * unbounded directions last and with tab->n_unbounded set
336 * to the number of unbounded directions.
337 * Furthermore, the calling functions needs to add shifted copies
338 * of all constraints involving unbounded directions to ensure
339 * that any feasible rational value in these directions can be rounded
340 * up to yield a feasible integer value.
341 * In particular, let B define the given basis x' = B x
342 * and let T be the inverse of B, i.e., X = T x'.
343 * Let a x + c >= 0 be a constraint of the set represented by the tableau,
344 * or a T x' + c >= 0 in terms of the given basis. Assume that
345 * the bounded directions have an integer value, then we can safely
346 * round up the values for the unbounded directions if we make sure
347 * that x' not only satisfies the original constraint, but also
348 * the constraint "a T x' + c + s >= 0" with s the sum of all
349 * negative values in the last n_unbounded entries of "a T".
350 * The calling function therefore needs to add the constraint
351 * a x + c + s >= 0. The current function then scans the first
352 * directions for an integer value and once those have been found,
353 * it can compute "T ceil(B x)" to yield an integer point in the set.
354 * Note that during the search, the first rows of B may be changed
355 * by a basis reduction, but the last n_unbounded rows of B remain
356 * unaltered and are also not mixed into the first rows.
357 *
358 * The search is implemented iteratively. "level" identifies the current
359 * basis vector. "init" is true if we want the first value at the current
360 * level and false if we want the next value.
361 *
362 * At the start of each level, we first check if we can find a solution
363 * using greedy search. If not, we continue with the exhaustive search.
364 *
365 * The initial basis is the identity matrix. If the range in some direction
366 * contains more than one integer value, we perform basis reduction based
367 * on the value of ctx->opt->gbr
368 * - ISL_GBR_NEVER: never perform basis reduction
369 * - ISL_GBR_ONCE: only perform basis reduction the first
370 * time such a range is encountered
371 * - ISL_GBR_ALWAYS: always perform basis reduction when
372 * such a range is encountered
373 *
374 * When ctx->opt->gbr is set to ISL_GBR_ALWAYS, then we allow the basis
375 * reduction computation to return early. That is, as soon as it
376 * finds a reasonable first direction.
377 */
378struct isl_vec *isl_tab_sample(struct isl_tab *tab)
379{
380 unsigned dim;
381 unsigned gbr;
382 struct isl_ctx *ctx;
383 struct isl_vec *sample;
384 struct isl_vec *min;
385 struct isl_vec *max;
386 enum isl_lp_result res;
387 int level;
388 int init;
389 int reduced;
390 struct isl_tab_undo **snap;
391
392 if (!tab)
393 return NULL((void*)0);
394 if (tab->empty)
395 return isl_vec_alloc(tab->mat->ctx, 0);
396
397 if (!tab->basis)
398 tab->basis = initial_basis(tab);
399 if (!tab->basis)
400 return NULL((void*)0);
401 isl_assert(tab->mat->ctx, tab->basis->n_row == tab->n_var + 1,do { if (tab->basis->n_row == tab->n_var + 1) break;
do { isl_handle_error(tab->mat->ctx, isl_error_unknown
, "Assertion \"" "tab->basis->n_row == tab->n_var + 1"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 402); return ((void*)0); } while (0); } while (0)
402 return NULL)do { if (tab->basis->n_row == tab->n_var + 1) break;
do { isl_handle_error(tab->mat->ctx, isl_error_unknown
, "Assertion \"" "tab->basis->n_row == tab->n_var + 1"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 402); return ((void*)0); } while (0); } while (0)
;
403 isl_assert(tab->mat->ctx, tab->basis->n_col == tab->n_var + 1,do { if (tab->basis->n_col == tab->n_var + 1) break;
do { isl_handle_error(tab->mat->ctx, isl_error_unknown
, "Assertion \"" "tab->basis->n_col == tab->n_var + 1"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 404); return ((void*)0); } while (0); } while (0)
404 return NULL)do { if (tab->basis->n_col == tab->n_var + 1) break;
do { isl_handle_error(tab->mat->ctx, isl_error_unknown
, "Assertion \"" "tab->basis->n_col == tab->n_var + 1"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 404); return ((void*)0); } while (0); } while (0)
;
405
406 ctx = tab->mat->ctx;
407 dim = tab->n_var;
408 gbr = ctx->opt->gbr;
409
410 if (tab->n_unbounded == tab->n_var) {
411 sample = isl_tab_get_sample_value(tab);
412 sample = isl_mat_vec_product(isl_mat_copy(tab->basis), sample);
413 sample = isl_vec_ceil(sample);
414 sample = isl_mat_vec_inverse_product(isl_mat_copy(tab->basis),
415 sample);
416 return sample;
417 }
418
419 if (isl_tab_extend_cons(tab, dim + 1) < 0)
420 return NULL((void*)0);
421
422 min = isl_vec_alloc(ctx, dim);
423 max = isl_vec_alloc(ctx, dim);
424 snap = isl_alloc_array(ctx, struct isl_tab_undo *, dim)((struct isl_tab_undo * *)isl_malloc_or_die(ctx, (dim)*sizeof
(struct isl_tab_undo *)))
;
425
426 if (!min || !max || !snap)
427 goto error;
428
429 level = 0;
430 init = 1;
431 reduced = 0;
432
433 while (level >= 0) {
434 if (init) {
435 int choice;
436
437 res = compute_min(ctx, tab, min, level);
438 if (res == isl_lp_error)
439 goto error;
440 if (res != isl_lp_ok)
441 isl_die(ctx, isl_error_internal,do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 443); goto error; } while (0)
442 "expecting bounded rational solution",do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 443); goto error; } while (0)
443 goto error)do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 443); goto error; } while (0)
;
444 if (isl_tab_sample_is_integer(tab))
445 break;
446 res = compute_max(ctx, tab, max, level);
447 if (res == isl_lp_error)
448 goto error;
449 if (res != isl_lp_ok)
450 isl_die(ctx, isl_error_internal,do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 452); goto error; } while (0)
451 "expecting bounded rational solution",do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 452); goto error; } while (0)
452 goto error)do { isl_handle_error(ctx, isl_error_internal, "expecting bounded rational solution"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 452); goto error; } while (0)
;
453 if (isl_tab_sample_is_integer(tab))
454 break;
455 choice = isl_int_lt(min->el[level], max->el[level])(isl_sioimath_cmp(*(min->el[level]), *(max->el[level]))
< 0)
;
456 if (choice) {
457 int g;
458 g = greedy_search(ctx, tab, min, max, level);
459 if (g < 0)
460 goto error;
461 if (g)
462 break;
463 }
464 if (!reduced && choice &&
465 ctx->opt->gbr != ISL_GBR_NEVER0) {
466 unsigned gbr_only_first;
467 if (ctx->opt->gbr == ISL_GBR_ONCE1)
468 ctx->opt->gbr = ISL_GBR_NEVER0;
469 tab->n_zero = level;
470 gbr_only_first = ctx->opt->gbr_only_first;
471 ctx->opt->gbr_only_first =
472 ctx->opt->gbr == ISL_GBR_ALWAYS2;
473 tab = isl_tab_compute_reduced_basis(tab);
474 ctx->opt->gbr_only_first = gbr_only_first;
475 if (!tab || !tab->basis)
476 goto error;
477 reduced = 1;
478 continue;
479 }
480 reduced = 0;
481 snap[level] = isl_tab_snap(tab);
482 } else
483 isl_int_add_ui(min->el[level], min->el[level], 1)isl_sioimath_add_ui((min->el[level]), *(min->el[level])
, 1)
;
484
485 if (isl_int_gt(min->el[level], max->el[level])(isl_sioimath_cmp(*(min->el[level]), *(max->el[level]))
> 0)
) {
486 level--;
487 init = 0;
488 if (level >= 0)
489 if (isl_tab_rollback(tab, snap[level]) < 0)
490 goto error;
491 continue;
492 }
493 isl_int_neg(tab->basis->row[1 + level][0], min->el[level])isl_sioimath_neg((tab->basis->row[1 + level][0]), *(min
->el[level]))
;
494 if (isl_tab_add_valid_eq(tab, tab->basis->row[1 + level]) < 0)
495 goto error;
496 isl_int_set_si(tab->basis->row[1 + level][0], 0)isl_sioimath_set_si((tab->basis->row[1 + level][0]), 0);
497 if (level + tab->n_unbounded < dim - 1) {
498 ++level;
499 init = 1;
500 continue;
501 }
502 break;
503 }
504
505 if (level >= 0) {
506 sample = isl_tab_get_sample_value(tab);
507 if (!sample)
508 goto error;
509 if (tab->n_unbounded && !isl_int_is_one(sample->el[0])(isl_sioimath_cmp_si(*(sample->el[0]), 1) == 0)) {
510 sample = isl_mat_vec_product(isl_mat_copy(tab->basis),
511 sample);
512 sample = isl_vec_ceil(sample);
513 sample = isl_mat_vec_inverse_product(
514 isl_mat_copy(tab->basis), sample);
515 }
516 } else
517 sample = isl_vec_alloc(ctx, 0);
518
519 ctx->opt->gbr = gbr;
520 isl_vec_free(min);
521 isl_vec_free(max);
522 free(snap);
523 return sample;
524error:
525 ctx->opt->gbr = gbr;
526 isl_vec_free(min);
527 isl_vec_free(max);
528 free(snap);
529 return NULL((void*)0);
530}
531
532static __isl_give isl_vec *sample_bounded(__isl_take isl_basic_setisl_basic_map *bset);
533
534/* Compute a sample point of the given basic set, based on the given,
535 * non-trivial factorization.
536 */
537static __isl_give isl_vec *factored_sample(__isl_take isl_basic_setisl_basic_map *bset,
538 __isl_take isl_factorizer *f)
539{
540 int i, n;
541 isl_vec *sample = NULL((void*)0);
542 isl_ctx *ctx;
543 isl_size nparam;
544 isl_size nvar;
545 isl_size total;
546
547 ctx = isl_basic_set_get_ctx(bset);
548 nparam = isl_basic_set_dim(bset, isl_dim_param);
549 nvar = isl_basic_set_dim(bset, isl_dim_set);
550 total = isl_basic_set_dim(bset, isl_dim_all);
551 if (!ctx || nparam < 0 || nvar < 0 || total < 0)
552 goto error;
553
554 sample = isl_vec_alloc(ctx, 1 + total);
555 if (!sample)
556 goto error;
557 isl_int_set_si(sample->el[0], 1)isl_sioimath_set_si((sample->el[0]), 1);
558
559 bset = isl_morph_basic_set(isl_morph_copy(f->morph), bset);
560
561 for (i = 0, n = 0; i < f->n_group; ++i) {
562 isl_basic_setisl_basic_map *bset_i;
563 isl_vec *sample_i;
564
565 bset_i = isl_basic_set_copy(bset);
566 bset_i = isl_basic_set_drop_constraints_involving(bset_i,
567 nparam + n + f->len[i], nvar - n - f->len[i]);
568 bset_i = isl_basic_set_drop_constraints_involving(bset_i,
569 nparam, n);
570 bset_i = isl_basic_set_drop(bset_i, isl_dim_set,
571 n + f->len[i], nvar - n - f->len[i]);
572 bset_i = isl_basic_set_drop(bset_i, isl_dim_set, 0, n);
573
574 sample_i = sample_bounded(bset_i);
575 if (!sample_i)
576 goto error;
577 if (sample_i->size == 0) {
578 isl_basic_set_free(bset);
579 isl_factorizer_free(f);
580 isl_vec_free(sample);
581 return sample_i;
582 }
583 isl_seq_cpy(sample->el + 1 + nparam + n,
584 sample_i->el + 1, f->len[i]);
585 isl_vec_free(sample_i);
586
587 n += f->len[i];
588 }
589
590 f->morph = isl_morph_inverse(f->morph);
591 sample = isl_morph_vec(isl_morph_copy(f->morph), sample);
592
593 isl_basic_set_free(bset);
594 isl_factorizer_free(f);
595 return sample;
596error:
597 isl_basic_set_free(bset);
598 isl_factorizer_free(f);
599 isl_vec_free(sample);
600 return NULL((void*)0);
601}
602
603/* Given a basic set that is known to be bounded, find and return
604 * an integer point in the basic set, if there is any.
605 *
606 * After handling some trivial cases, we construct a tableau
607 * and then use isl_tab_sample to find a sample, passing it
608 * the identity matrix as initial basis.
609 */
610static __isl_give isl_vec *sample_bounded(__isl_take isl_basic_setisl_basic_map *bset)
611{
612 isl_size dim;
613 struct isl_vec *sample;
614 struct isl_tab *tab = NULL((void*)0);
615 isl_factorizer *f;
616
617 if (!bset)
618 return NULL((void*)0);
619
620 if (isl_basic_set_plain_is_empty(bset))
621 return empty_sample(bset);
622
623 dim = isl_basic_set_dim(bset, isl_dim_all);
624 if (dim < 0)
625 bset = isl_basic_set_free(bset);
626 if (dim == 0)
627 return zero_sample(bset);
628 if (dim == 1)
629 return interval_sample(bset);
630 if (bset->n_eq > 0)
631 return sample_eq(bset, sample_bounded);
632
633 f = isl_basic_set_factorizer(bset);
634 if (!f)
635 goto error;
636 if (f->n_group != 0)
637 return factored_sample(bset, f);
638 isl_factorizer_free(f);
639
640 tab = isl_tab_from_basic_set(bset, 1);
641 if (tab && tab->empty) {
642 isl_tab_free(tab);
643 ISL_F_SET(bset, ISL_BASIC_SET_EMPTY)(((bset)->flags) |= ((1 << 1)));
644 sample = isl_vec_alloc(isl_basic_set_get_ctx(bset), 0);
645 isl_basic_set_free(bset);
646 return sample;
647 }
648
649 if (!ISL_F_ISSET(bset, ISL_BASIC_SET_NO_IMPLICIT)(!!(((bset)->flags) & ((1 << 2)))))
650 if (isl_tab_detect_implicit_equalities(tab) < 0)
651 goto error;
652
653 sample = isl_tab_sample(tab);
654 if (!sample)
655 goto error;
656
657 if (sample->size > 0) {
658 isl_vec_free(bset->sample);
659 bset->sample = isl_vec_copy(sample);
660 }
661
662 isl_basic_set_free(bset);
663 isl_tab_free(tab);
664 return sample;
665error:
666 isl_basic_set_free(bset);
667 isl_tab_free(tab);
668 return NULL((void*)0);
669}
670
671/* Given a basic set "bset" and a value "sample" for the first coordinates
672 * of bset, plug in these values and drop the corresponding coordinates.
673 *
674 * We do this by computing the preimage of the transformation
675 *
676 * [ 1 0 ]
677 * x = [ s 0 ] x'
678 * [ 0 I ]
679 *
680 * where [1 s] is the sample value and I is the identity matrix of the
681 * appropriate dimension.
682 */
683static __isl_give isl_basic_setisl_basic_map *plug_in(__isl_take isl_basic_setisl_basic_map *bset,
684 __isl_take isl_vec *sample)
685{
686 int i;
687 isl_size total;
688 struct isl_mat *T;
689
690 total = isl_basic_set_dim(bset, isl_dim_all);
691 if (total < 0 || !sample)
692 goto error;
693
694 T = isl_mat_alloc(bset->ctx, 1 + total, 1 + total - (sample->size - 1));
695 if (!T)
696 goto error;
697
698 for (i = 0; i < sample->size; ++i) {
699 isl_int_set(T->row[i][0], sample->el[i])isl_sioimath_set((T->row[i][0]), *(sample->el[i]));
700 isl_seq_clr(T->row[i] + 1, T->n_col - 1);
701 }
702 for (i = 0; i < T->n_col - 1; ++i) {
703 isl_seq_clr(T->row[sample->size + i], T->n_col);
704 isl_int_set_si(T->row[sample->size + i][1 + i], 1)isl_sioimath_set_si((T->row[sample->size + i][1 + i]), 1
)
;
705 }
706 isl_vec_free(sample);
707
708 bset = isl_basic_set_preimage(bset, T);
709 return bset;
710error:
711 isl_basic_set_free(bset);
712 isl_vec_free(sample);
713 return NULL((void*)0);
714}
715
716/* Given a basic set "bset", return any (possibly non-integer) point
717 * in the basic set.
718 */
719static __isl_give isl_vec *rational_sample(__isl_take isl_basic_setisl_basic_map *bset)
720{
721 struct isl_tab *tab;
722 struct isl_vec *sample;
723
724 if (!bset)
725 return NULL((void*)0);
726
727 tab = isl_tab_from_basic_set(bset, 0);
728 sample = isl_tab_get_sample_value(tab);
729 isl_tab_free(tab);
730
731 isl_basic_set_free(bset);
732
733 return sample;
734}
735
736/* Given a linear cone "cone" and a rational point "vec",
737 * construct a polyhedron with shifted copies of the constraints in "cone",
738 * i.e., a polyhedron with "cone" as its recession cone, such that each
739 * point x in this polyhedron is such that the unit box positioned at x
740 * lies entirely inside the affine cone 'vec + cone'.
741 * Any rational point in this polyhedron may therefore be rounded up
742 * to yield an integer point that lies inside said affine cone.
743 *
744 * Denote the constraints of cone by "<a_i, x> >= 0" and the rational
745 * point "vec" by v/d.
746 * Let b_i = <a_i, v>. Then the affine cone 'vec + cone' is given
747 * by <a_i, x> - b/d >= 0.
748 * The polyhedron <a_i, x> - ceil{b/d} >= 0 is a subset of this affine cone.
749 * We prefer this polyhedron over the actual affine cone because it doesn't
750 * require a scaling of the constraints.
751 * If each of the vertices of the unit cube positioned at x lies inside
752 * this polyhedron, then the whole unit cube at x lies inside the affine cone.
753 * We therefore impose that x' = x + \sum e_i, for any selection of unit
754 * vectors lies inside the polyhedron, i.e.,
755 *
756 * <a_i, x'> - ceil{b/d} = <a_i, x> + sum a_i - ceil{b/d} >= 0
757 *
758 * The most stringent of these constraints is the one that selects
759 * all negative a_i, so the polyhedron we are looking for has constraints
760 *
761 * <a_i, x> + sum_{a_i < 0} a_i - ceil{b/d} >= 0
762 *
763 * Note that if cone were known to have only non-negative rays
764 * (which can be accomplished by a unimodular transformation),
765 * then we would only have to check the points x' = x + e_i
766 * and we only have to add the smallest negative a_i (if any)
767 * instead of the sum of all negative a_i.
768 */
769static __isl_give isl_basic_setisl_basic_map *shift_cone(__isl_take isl_basic_setisl_basic_map *cone,
770 __isl_take isl_vec *vec)
771{
772 int i, j, k;
773 isl_size total;
774
775 struct isl_basic_setisl_basic_map *shift = NULL((void*)0);
776
777 total = isl_basic_set_dim(cone, isl_dim_all);
778 if (total < 0 || !vec)
779 goto error;
780
781 isl_assert(cone->ctx, cone->n_eq == 0, goto error)do { if (cone->n_eq == 0) break; do { isl_handle_error(cone
->ctx, isl_error_unknown, "Assertion \"" "cone->n_eq == 0"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 781); goto error; } while (0); } while (0)
;
782
783 shift = isl_basic_set_alloc_space(isl_basic_set_get_space(cone),
784 0, 0, cone->n_ineq);
785
786 for (i = 0; i < cone->n_ineq; ++i) {
787 k = isl_basic_set_alloc_inequality(shift);
788 if (k < 0)
789 goto error;
790 isl_seq_cpy(shift->ineq[k] + 1, cone->ineq[i] + 1, total);
791 isl_seq_inner_product(shift->ineq[k] + 1, vec->el + 1, total,
792 &shift->ineq[k][0]);
793 isl_int_cdiv_q(shift->ineq[k][0],isl_sioimath_cdiv_q((shift->ineq[k][0]), *(shift->ineq[
k][0]), *(vec->el[0]))
794 shift->ineq[k][0], vec->el[0])isl_sioimath_cdiv_q((shift->ineq[k][0]), *(shift->ineq[
k][0]), *(vec->el[0]))
;
795 isl_int_neg(shift->ineq[k][0], shift->ineq[k][0])isl_sioimath_neg((shift->ineq[k][0]), *(shift->ineq[k][
0]))
;
796 for (j = 0; j < total; ++j) {
797 if (isl_int_is_nonneg(shift->ineq[k][1 + j])(isl_sioimath_sgn(*(shift->ineq[k][1 + j])) >= 0))
798 continue;
799 isl_int_add(shift->ineq[k][0],isl_sioimath_add((shift->ineq[k][0]), *(shift->ineq[k][
0]), *(shift->ineq[k][1 + j]))
800 shift->ineq[k][0], shift->ineq[k][1 + j])isl_sioimath_add((shift->ineq[k][0]), *(shift->ineq[k][
0]), *(shift->ineq[k][1 + j]))
;
801 }
802 }
803
804 isl_basic_set_free(cone);
805 isl_vec_free(vec);
806
807 return isl_basic_set_finalize(shift);
808error:
809 isl_basic_set_free(shift);
810 isl_basic_set_free(cone);
811 isl_vec_free(vec);
812 return NULL((void*)0);
813}
814
815/* Given a rational point vec in a (transformed) basic set,
816 * such that cone is the recession cone of the original basic set,
817 * "round up" the rational point to an integer point.
818 *
819 * We first check if the rational point just happens to be integer.
820 * If not, we transform the cone in the same way as the basic set,
821 * pick a point x in this cone shifted to the rational point such that
822 * the whole unit cube at x is also inside this affine cone.
823 * Then we simply round up the coordinates of x and return the
824 * resulting integer point.
825 */
826static __isl_give isl_vec *round_up_in_cone(__isl_take isl_vec *vec,
827 __isl_take isl_basic_setisl_basic_map *cone, __isl_take isl_mat *U)
828{
829 isl_size total;
830
831 if (!vec || !cone || !U)
832 goto error;
833
834 isl_assert(vec->ctx, vec->size != 0, goto error)do { if (vec->size != 0) break; do { isl_handle_error(vec->
ctx, isl_error_unknown, "Assertion \"" "vec->size != 0" "\" failed"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 834); goto error; } while (0); } while (0)
;
835 if (isl_int_is_one(vec->el[0])(isl_sioimath_cmp_si(*(vec->el[0]), 1) == 0)) {
836 isl_mat_free(U);
837 isl_basic_set_free(cone);
838 return vec;
839 }
840
841 total = isl_basic_set_dim(cone, isl_dim_all);
842 if (total < 0)
843 goto error;
844 cone = isl_basic_set_preimage(cone, U);
845 cone = isl_basic_set_remove_dims(cone, isl_dim_set,
846 0, total - (vec->size - 1));
847
848 cone = shift_cone(cone, vec);
849
850 vec = rational_sample(cone);
851 vec = isl_vec_ceil(vec);
852 return vec;
853error:
854 isl_mat_free(U);
855 isl_vec_free(vec);
856 isl_basic_set_free(cone);
857 return NULL((void*)0);
858}
859
860/* Concatenate two integer vectors, i.e., two vectors with denominator
861 * (stored in element 0) equal to 1.
862 */
863static __isl_give isl_vec *vec_concat(__isl_take isl_vec *vec1,
864 __isl_take isl_vec *vec2)
865{
866 struct isl_vec *vec;
867
868 if (!vec1 || !vec2)
869 goto error;
870 isl_assert(vec1->ctx, vec1->size > 0, goto error)do { if (vec1->size > 0) break; do { isl_handle_error(vec1
->ctx, isl_error_unknown, "Assertion \"" "vec1->size > 0"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 870); goto error; } while (0); } while (0)
;
871 isl_assert(vec2->ctx, vec2->size > 0, goto error)do { if (vec2->size > 0) break; do { isl_handle_error(vec2
->ctx, isl_error_unknown, "Assertion \"" "vec2->size > 0"
"\" failed", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 871); goto error; } while (0); } while (0)
;
872 isl_assert(vec1->ctx, isl_int_is_one(vec1->el[0]), goto error)do { if ((isl_sioimath_cmp_si(*(vec1->el[0]), 1) == 0)) break
; do { isl_handle_error(vec1->ctx, isl_error_unknown, "Assertion \""
"(isl_sioimath_cmp_si(*(vec1->el[0]), 1) == 0)" "\" failed"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 872); goto error; } while (0); } while (0)
;
873 isl_assert(vec2->ctx, isl_int_is_one(vec2->el[0]), goto error)do { if ((isl_sioimath_cmp_si(*(vec2->el[0]), 1) == 0)) break
; do { isl_handle_error(vec2->ctx, isl_error_unknown, "Assertion \""
"(isl_sioimath_cmp_si(*(vec2->el[0]), 1) == 0)" "\" failed"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 873); goto error; } while (0); } while (0)
;
874
875 vec = isl_vec_alloc(vec1->ctx, vec1->size + vec2->size - 1);
876 if (!vec)
877 goto error;
878
879 isl_seq_cpy(vec->el, vec1->el, vec1->size);
880 isl_seq_cpy(vec->el + vec1->size, vec2->el + 1, vec2->size - 1);
881
882 isl_vec_free(vec1);
883 isl_vec_free(vec2);
884
885 return vec;
886error:
887 isl_vec_free(vec1);
888 isl_vec_free(vec2);
889 return NULL((void*)0);
890}
891
892/* Give a basic set "bset" with recession cone "cone", compute and
893 * return an integer point in bset, if any.
894 *
895 * If the recession cone is full-dimensional, then we know that
896 * bset contains an infinite number of integer points and it is
897 * fairly easy to pick one of them.
898 * If the recession cone is not full-dimensional, then we first
899 * transform bset such that the bounded directions appear as
900 * the first dimensions of the transformed basic set.
901 * We do this by using a unimodular transformation that transforms
902 * the equalities in the recession cone to equalities on the first
903 * dimensions.
904 *
905 * The transformed set is then projected onto its bounded dimensions.
906 * Note that to compute this projection, we can simply drop all constraints
907 * involving any of the unbounded dimensions since these constraints
908 * cannot be combined to produce a constraint on the bounded dimensions.
909 * To see this, assume that there is such a combination of constraints
910 * that produces a constraint on the bounded dimensions. This means
911 * that some combination of the unbounded dimensions has both an upper
912 * bound and a lower bound in terms of the bounded dimensions, but then
913 * this combination would be a bounded direction too and would have been
914 * transformed into a bounded dimensions.
915 *
916 * We then compute a sample value in the bounded dimensions.
917 * If no such value can be found, then the original set did not contain
918 * any integer points and we are done.
919 * Otherwise, we plug in the value we found in the bounded dimensions,
920 * project out these bounded dimensions and end up with a set with
921 * a full-dimensional recession cone.
922 * A sample point in this set is computed by "rounding up" any
923 * rational point in the set.
924 *
925 * The sample points in the bounded and unbounded dimensions are
926 * then combined into a single sample point and transformed back
927 * to the original space.
928 */
929__isl_give isl_vec *isl_basic_set_sample_with_cone(
930 __isl_take isl_basic_setisl_basic_map *bset, __isl_take isl_basic_setisl_basic_map *cone)
931{
932 isl_size total;
933 unsigned cone_dim;
934 struct isl_mat *M, *U;
935 struct isl_vec *sample;
936 struct isl_vec *cone_sample;
937 struct isl_ctx *ctx;
938 struct isl_basic_setisl_basic_map *bounded;
939
940 total = isl_basic_set_dim(cone, isl_dim_all);
941 if (!bset || total < 0)
942 goto error;
943
944 ctx = isl_basic_set_get_ctx(bset);
945 cone_dim = total - cone->n_eq;
946
947 M = isl_mat_sub_alloc6(ctx, cone->eq, 0, cone->n_eq, 1, total);
948 M = isl_mat_left_hermite(M, 0, &U, NULL((void*)0));
949 if (!M)
950 goto error;
951 isl_mat_free(M);
952
953 U = isl_mat_lin_to_aff(U);
954 bset = isl_basic_set_preimage(bset, isl_mat_copy(U));
955
956 bounded = isl_basic_set_copy(bset);
957 bounded = isl_basic_set_drop_constraints_involving(bounded,
958 total - cone_dim, cone_dim);
959 bounded = isl_basic_set_drop_dims(bounded, total - cone_dim, cone_dim);
960 sample = sample_bounded(bounded);
961 if (!sample || sample->size == 0) {
962 isl_basic_set_free(bset);
963 isl_basic_set_free(cone);
964 isl_mat_free(U);
965 return sample;
966 }
967 bset = plug_in(bset, isl_vec_copy(sample));
968 cone_sample = rational_sample(bset);
969 cone_sample = round_up_in_cone(cone_sample, cone, isl_mat_copy(U));
970 sample = vec_concat(sample, cone_sample);
971 sample = isl_mat_vec_product(U, sample);
972 return sample;
973error:
974 isl_basic_set_free(cone);
975 isl_basic_set_free(bset);
976 return NULL((void*)0);
977}
978
979static void vec_sum_of_neg(struct isl_vec *v, isl_int *s)
980{
981 int i;
982
983 isl_int_set_si(*s, 0)isl_sioimath_set_si((*s), 0);
984
985 for (i = 0; i < v->size; ++i)
986 if (isl_int_is_neg(v->el[i])(isl_sioimath_sgn(*(v->el[i])) < 0))
987 isl_int_add(*s, *s, v->el[i])isl_sioimath_add((*s), *(*s), *(v->el[i]));
988}
989
990/* Given a tableau "tab", a tableau "tab_cone" that corresponds
991 * to the recession cone and the inverse of a new basis U = inv(B),
992 * with the unbounded directions in B last,
993 * add constraints to "tab" that ensure any rational value
994 * in the unbounded directions can be rounded up to an integer value.
995 *
996 * The new basis is given by x' = B x, i.e., x = U x'.
997 * For any rational value of the last tab->n_unbounded coordinates
998 * in the update tableau, the value that is obtained by rounding
999 * up this value should be contained in the original tableau.
1000 * For any constraint "a x + c >= 0", we therefore need to add
1001 * a constraint "a x + c + s >= 0", with s the sum of all negative
1002 * entries in the last elements of "a U".
1003 *
1004 * Since we are not interested in the first entries of any of the "a U",
1005 * we first drop the columns of U that correpond to bounded directions.
1006 */
1007static int tab_shift_cone(struct isl_tab *tab,
1008 struct isl_tab *tab_cone, struct isl_mat *U)
1009{
1010 int i;
1011 isl_int v;
1012 struct isl_basic_setisl_basic_map *bset = NULL((void*)0);
1013
1014 if (tab && tab->n_unbounded == 0) {
1015 isl_mat_free(U);
1016 return 0;
1017 }
1018 isl_int_init(v)isl_sioimath_init((v));
1019 if (!tab || !tab_cone || !U)
1020 goto error;
1021 bset = isl_tab_peek_bset(tab_cone);
1022 U = isl_mat_drop_cols(U, 0, tab->n_var - tab->n_unbounded);
1023 for (i = 0; i < bset->n_ineq; ++i) {
1024 int ok;
1025 struct isl_vec *row = NULL((void*)0);
1026 if (isl_tab_is_equality(tab_cone, tab_cone->n_eq + i))
1027 continue;
1028 row = isl_vec_alloc(bset->ctx, tab_cone->n_var);
1029 if (!row)
1030 goto error;
1031 isl_seq_cpy(row->el, bset->ineq[i] + 1, tab_cone->n_var);
1032 row = isl_vec_mat_product(row, isl_mat_copy(U));
1033 if (!row)
1034 goto error;
1035 vec_sum_of_neg(row, &v);
1036 isl_vec_free(row);
1037 if (isl_int_is_zero(v)(isl_sioimath_sgn(*(v)) == 0))
1038 continue;
1039 if (isl_tab_extend_cons(tab, 1) < 0)
1040 goto error;
1041 isl_int_add(bset->ineq[i][0], bset->ineq[i][0], v)isl_sioimath_add((bset->ineq[i][0]), *(bset->ineq[i][0]
), *(v))
;
1042 ok = isl_tab_add_ineq(tab, bset->ineq[i]) >= 0;
1043 isl_int_sub(bset->ineq[i][0], bset->ineq[i][0], v)isl_sioimath_sub((bset->ineq[i][0]), *(bset->ineq[i][0]
), *(v))
;
1044 if (!ok)
1045 goto error;
1046 }
1047
1048 isl_mat_free(U);
1049 isl_int_clear(v)isl_sioimath_clear((v));
1050 return 0;
1051error:
1052 isl_mat_free(U);
1053 isl_int_clear(v)isl_sioimath_clear((v));
1054 return -1;
1055}
1056
1057/* Compute and return an initial basis for the possibly
1058 * unbounded tableau "tab". "tab_cone" is a tableau
1059 * for the corresponding recession cone.
1060 * Additionally, add constraints to "tab" that ensure
1061 * that any rational value for the unbounded directions
1062 * can be rounded up to an integer value.
1063 *
1064 * If the tableau is bounded, i.e., if the recession cone
1065 * is zero-dimensional, then we just use inital_basis.
1066 * Otherwise, we construct a basis whose first directions
1067 * correspond to equalities, followed by bounded directions,
1068 * i.e., equalities in the recession cone.
1069 * The remaining directions are then unbounded.
1070 */
1071int isl_tab_set_initial_basis_with_cone(struct isl_tab *tab,
1072 struct isl_tab *tab_cone)
1073{
1074 struct isl_mat *eq;
1075 struct isl_mat *cone_eq;
1076 struct isl_mat *U, *Q;
1077
1078 if (!tab || !tab_cone)
1079 return -1;
1080
1081 if (tab_cone->n_col == tab_cone->n_dead) {
1082 tab->basis = initial_basis(tab);
1083 return tab->basis ? 0 : -1;
1084 }
1085
1086 eq = tab_equalities(tab);
1087 if (!eq)
1088 return -1;
1089 tab->n_zero = eq->n_row;
1090 cone_eq = tab_equalities(tab_cone);
1091 eq = isl_mat_concat(eq, cone_eq);
1092 if (!eq)
1093 return -1;
1094 tab->n_unbounded = tab->n_var - (eq->n_row - tab->n_zero);
1095 eq = isl_mat_left_hermite(eq, 0, &U, &Q);
1096 if (!eq)
1097 return -1;
1098 isl_mat_free(eq);
1099 tab->basis = isl_mat_lin_to_aff(Q);
1100 if (tab_shift_cone(tab, tab_cone, U) < 0)
1101 return -1;
1102 if (!tab->basis)
1103 return -1;
1104 return 0;
1105}
1106
1107/* Compute and return a sample point in bset using generalized basis
1108 * reduction. We first check if the input set has a non-trivial
1109 * recession cone. If so, we perform some extra preprocessing in
1110 * sample_with_cone. Otherwise, we directly perform generalized basis
1111 * reduction.
1112 */
1113static __isl_give isl_vec *gbr_sample(__isl_take isl_basic_setisl_basic_map *bset)
1114{
1115 isl_size dim;
1116 struct isl_basic_setisl_basic_map *cone;
1117
1118 dim = isl_basic_set_dim(bset, isl_dim_all);
1119 if (dim < 0)
1120 goto error;
1121
1122 cone = isl_basic_set_recession_cone(isl_basic_set_copy(bset));
1123 if (!cone)
1124 goto error;
1125
1126 if (cone->n_eq < dim)
1127 return isl_basic_set_sample_with_cone(bset, cone);
1128
1129 isl_basic_set_free(cone);
1130 return sample_bounded(bset);
1131error:
1132 isl_basic_set_free(bset);
1133 return NULL((void*)0);
1134}
1135
1136static __isl_give isl_vec *basic_set_sample(__isl_take isl_basic_setisl_basic_map *bset,
1137 int bounded)
1138{
1139 struct isl_ctx *ctx;
1140 isl_size dim;
1141 if (!bset)
1142 return NULL((void*)0);
1143
1144 ctx = bset->ctx;
Value stored to 'ctx' is never read
1145 if (isl_basic_set_plain_is_empty(bset))
1146 return empty_sample(bset);
1147
1148 dim = isl_basic_set_dim(bset, isl_dim_set);
1149 if (dim < 0 ||
1150 isl_basic_set_check_no_params(bset) < 0 ||
1151 isl_basic_set_check_no_locals(bset) < 0)
1152 goto error;
1153
1154 if (bset->sample && bset->sample->size == 1 + dim) {
1155 int contains = isl_basic_set_contains(bset, bset->sample);
1156 if (contains < 0)
1157 goto error;
1158 if (contains) {
1159 struct isl_vec *sample = isl_vec_copy(bset->sample);
1160 isl_basic_set_free(bset);
1161 return sample;
1162 }
1163 }
1164 isl_vec_free(bset->sample);
1165 bset->sample = NULL((void*)0);
1166
1167 if (bset->n_eq > 0)
1168 return sample_eq(bset, bounded ? isl_basic_set_sample_bounded
1169 : isl_basic_set_sample_vec);
1170 if (dim == 0)
1171 return zero_sample(bset);
1172 if (dim == 1)
1173 return interval_sample(bset);
1174
1175 return bounded ? sample_bounded(bset) : gbr_sample(bset);
1176error:
1177 isl_basic_set_free(bset);
1178 return NULL((void*)0);
1179}
1180
1181__isl_give isl_vec *isl_basic_set_sample_vec(__isl_take isl_basic_setisl_basic_map *bset)
1182{
1183 return basic_set_sample(bset, 0);
1184}
1185
1186/* Compute an integer sample in "bset", where the caller guarantees
1187 * that "bset" is bounded.
1188 */
1189__isl_give isl_vec *isl_basic_set_sample_bounded(__isl_take isl_basic_setisl_basic_map *bset)
1190{
1191 return basic_set_sample(bset, 1);
1192}
1193
1194__isl_give isl_basic_setisl_basic_map *isl_basic_set_from_vec(__isl_take isl_vec *vec)
1195{
1196 int i;
1197 int k;
1198 struct isl_basic_setisl_basic_map *bset = NULL((void*)0);
1199 struct isl_ctx *ctx;
1200 isl_size dim;
1201
1202 if (!vec)
1203 return NULL((void*)0);
1204 ctx = vec->ctx;
1205 isl_assert(ctx, vec->size != 0, goto error)do { if (vec->size != 0) break; do { isl_handle_error(ctx,
isl_error_unknown, "Assertion \"" "vec->size != 0" "\" failed"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/polly/lib/External/isl/isl_sample.c"
, 1205); goto error; } while (0); } while (0)
;
1206
1207 bset = isl_basic_set_alloc(ctx, 0, vec->size - 1, 0, vec->size - 1, 0);
1208 dim = isl_basic_set_dim(bset, isl_dim_set);
1209 if (dim < 0)
1210 goto error;
1211 for (i = dim - 1; i >= 0; --i) {
1212 k = isl_basic_set_alloc_equality(bset);
1213 if (k < 0)
1214 goto error;
1215 isl_seq_clr(bset->eq[k], 1 + dim);
1216 isl_int_neg(bset->eq[k][0], vec->el[1 + i])isl_sioimath_neg((bset->eq[k][0]), *(vec->el[1 + i]));
1217 isl_int_set(bset->eq[k][1 + i], vec->el[0])isl_sioimath_set((bset->eq[k][1 + i]), *(vec->el[0]));
1218 }
1219 bset->sample = vec;
1220
1221 return bset;
1222error:
1223 isl_basic_set_free(bset);
1224 isl_vec_free(vec);
1225 return NULL((void*)0);
1226}
1227
1228__isl_give isl_basic_map *isl_basic_map_sample(__isl_take isl_basic_map *bmap)
1229{
1230 struct isl_basic_setisl_basic_map *bset;
1231 struct isl_vec *sample_vec;
1232
1233 bset = isl_basic_map_underlying_set(isl_basic_map_copy(bmap));
1234 sample_vec = isl_basic_set_sample_vec(bset);
1235 if (!sample_vec)
1236 goto error;
1237 if (sample_vec->size == 0) {
1238 isl_vec_free(sample_vec);
1239 return isl_basic_map_set_to_empty(bmap);
1240 }
1241 isl_vec_free(bmap->sample);
1242 bmap->sample = isl_vec_copy(sample_vec);
1243 bset = isl_basic_set_from_vec(sample_vec);
1244 return isl_basic_map_overlying_set(bset, bmap);
1245error:
1246 isl_basic_map_free(bmap);
1247 return NULL((void*)0);
1248}
1249
1250__isl_give isl_basic_setisl_basic_map *isl_basic_set_sample(__isl_take isl_basic_setisl_basic_map *bset)
1251{
1252 return isl_basic_map_sample(bset);
1253}
1254
1255__isl_give isl_basic_map *isl_map_sample(__isl_take isl_map *map)
1256{
1257 int i;
1258 isl_basic_map *sample = NULL((void*)0);
1259
1260 if (!map)
1261 goto error;
1262
1263 for (i = 0; i < map->n; ++i) {
1264 sample = isl_basic_map_sample(isl_basic_map_copy(map->p[i]));
1265 if (!sample)
1266 goto error;
1267 if (!ISL_F_ISSET(sample, ISL_BASIC_MAP_EMPTY)(!!(((sample)->flags) & ((1 << 1)))))
1268 break;
1269 isl_basic_map_free(sample);
1270 }
1271 if (i == map->n)
1272 sample = isl_basic_map_empty(isl_map_get_space(map));
1273 isl_map_free(map);
1274 return sample;
1275error:
1276 isl_map_free(map);
1277 return NULL((void*)0);
1278}
1279
1280__isl_give isl_basic_setisl_basic_map *isl_set_sample(__isl_take isl_setisl_map *set)
1281{
1282 return bset_from_bmap(isl_map_sample(set_to_map(set)));
1283}
1284
1285__isl_give isl_point *isl_basic_set_sample_point(__isl_take isl_basic_setisl_basic_map *bset)
1286{
1287 isl_vec *vec;
1288 isl_space *space;
1289
1290 space = isl_basic_set_get_space(bset);
1291 bset = isl_basic_set_underlying_set(bset);
1292 vec = isl_basic_set_sample_vec(bset);
1293
1294 return isl_point_alloc(space, vec);
1295}
1296
1297__isl_give isl_point *isl_set_sample_point(__isl_take isl_setisl_map *set)
1298{
1299 int i;
1300 isl_point *pnt;
1301
1302 if (!set)
1303 return NULL((void*)0);
1304
1305 for (i = 0; i < set->n; ++i) {
1306 pnt = isl_basic_set_sample_point(isl_basic_set_copy(set->p[i]));
1307 if (!pnt)
1308 goto error;
1309 if (!isl_point_is_void(pnt))
1310 break;
1311 isl_point_free(pnt);
1312 }
1313 if (i == set->n)
1314 pnt = isl_point_void(isl_set_get_space(set));
1315
1316 isl_set_free(set);
1317 return pnt;
1318error:
1319 isl_set_free(set);
1320 return NULL((void*)0);
1321}