+/*
+ * Copyright 2008-2009 Katholieke Universiteit Leuven
+ *
+ * Use of this software is governed by the GNU LGPLv2.1 license
+ *
+ * Written by Sven Verdoolaege, K.U.Leuven, Departement
+ * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
+ */
+
#include <assert.h>
-#include "isl_basis_reduction.h"
#include "isl_equalities.h"
#include "isl_seq.h"
-#include "isl_tab.h"
-#include "isl_vec.h"
+#include "isl_scan.h"
/* The input of this program is the same as that of the "polytope_scan"
* program from the barvinok distribution.
* The input set is assumed to be bounded.
*/
-static struct isl_mat *isl_basic_set_samples(struct isl_basic_set *bset);
-
-static struct isl_mat *samples_eq(struct isl_basic_set *bset)
-{
- struct isl_mat *T;
+struct scan_samples {
+ struct isl_scan_callback callback;
struct isl_mat *samples;
+};
- bset = isl_basic_set_remove_equalities(bset, &T, NULL);
- samples = isl_basic_set_samples(bset);
- return isl_mat_product(samples, isl_mat_transpose(T));
-}
-
-/* Add the current sample value of the tableau "tab" to the list
- * in "samples".
- */
-static struct isl_mat *add_solution(struct isl_mat *samples,
- struct isl_tab *tab)
+static int scan_samples_add_sample(struct isl_scan_callback *cb,
+ __isl_take isl_vec *sample)
{
- struct isl_vec *sample;
+ struct scan_samples *ss = (struct scan_samples *)cb;
- if (!samples || !tab)
- goto error;
- samples = isl_mat_extend(samples, samples->n_row + 1, samples->n_col);
- if (!samples)
- return NULL;
- sample = isl_tab_get_sample_value(tab);
- if (!sample)
+ ss->samples = isl_mat_extend(ss->samples, ss->samples->n_row + 1,
+ ss->samples->n_col);
+ if (!ss->samples)
goto error;
- isl_seq_cpy(samples->row[samples->n_row - 1], sample->el, sample->size);
+
+ isl_seq_cpy(ss->samples->row[ss->samples->n_row - 1],
+ sample->el, sample->size);
+
isl_vec_free(sample);
- return samples;
+ return 0;
error:
- isl_mat_free(samples);
- return NULL;
+ isl_vec_free(sample);
+ return -1;
}
-/* Look for and return all integer points in "bset", which is assumed
- * to be unbounded.
- *
- * We first compute a reduced basis for the set and then scan
- * the set in the directions of this basis.
- * We basically perform a depth first search, where in each level i
- * we compute the range in the i-th basis vector direction, given
- * fixed values in the directions of the previous basis vector.
- * We then add an equality to the tableau fixing the value in the
- * direction of the current basis vector to each value in the range
- * in turn and then continue to the next level.
- *
- * The search is implemented iteratively. "level" identifies the current
- * basis vector. "init" is true if we want the first value at the current
- * level and false if we want the next value.
- * Solutions are added in the leaves of the search tree, i.e., after
- * we have fixed a value in each direction of the basis.
- */
-static struct isl_mat *isl_basic_set_samples(struct isl_basic_set *bset)
+static struct isl_mat *isl_basic_set_scan_samples(struct isl_basic_set *bset)
{
unsigned dim;
- struct isl_mat *B = NULL;
- struct isl_tab *tab = NULL;
- struct isl_vec *min;
- struct isl_vec *max;
- struct isl_mat *samples;
- struct isl_tab_undo **snap;
- int level;
- int init;
- enum isl_lp_result res;
-
- if (bset->n_eq)
- return samples_eq(bset);
+ struct scan_samples ss;
dim = isl_basic_set_total_dim(bset);
-
- min = isl_vec_alloc(bset->ctx, dim);
- max = isl_vec_alloc(bset->ctx, dim);
- samples = isl_mat_alloc(bset->ctx, 0, 1 + dim);
- snap = isl_alloc_array(bset->ctx, struct isl_tab_undo *, dim);
-
- if (!min || !max || !samples || !snap)
- goto error;
-
- tab = isl_tab_from_basic_set(bset);
- if (!tab)
- goto error;
-
- tab->basis = isl_mat_identity(bset->ctx, dim);
- if (1)
- tab = isl_tab_compute_reduced_basis(tab);
- if (!tab)
- goto error;
- B = isl_mat_lin_to_aff(isl_mat_copy(tab->basis));
- if (!B)
+ ss.callback.add = scan_samples_add_sample;
+ ss.samples = isl_mat_alloc(bset->ctx, 0, 1 + dim);
+ if (!ss.samples)
goto error;
- level = 0;
- init = 1;
-
- while (level >= 0) {
- int empty = 0;
- if (init) {
- res = isl_tab_min(tab, B->row[1 + level],
- bset->ctx->one, &min->el[level], NULL, 0);
- if (res == isl_lp_empty)
- empty = 1;
- if (res == isl_lp_error || res == isl_lp_unbounded)
- goto error;
- isl_seq_neg(B->row[1 + level] + 1,
- B->row[1 + level] + 1, dim);
- res = isl_tab_min(tab, B->row[1 + level],
- bset->ctx->one, &max->el[level], NULL, 0);
- isl_seq_neg(B->row[1 + level] + 1,
- B->row[1 + level] + 1, dim);
- isl_int_neg(max->el[level], max->el[level]);
- if (res == isl_lp_empty)
- empty = 1;
- if (res == isl_lp_error || res == isl_lp_unbounded)
- goto error;
- snap[level] = isl_tab_snap(tab);
- } else
- isl_int_add_ui(min->el[level], min->el[level], 1);
-
- if (empty || isl_int_gt(min->el[level], max->el[level])) {
- level--;
- init = 0;
- if (level >= 0)
- isl_tab_rollback(tab, snap[level]);
- continue;
- }
- isl_int_neg(B->row[1 + level][0], min->el[level]);
- tab = isl_tab_add_valid_eq(tab, B->row[1 + level]);
- isl_int_set_si(B->row[1 + level][0], 0);
- if (level < dim - 1) {
- ++level;
- init = 1;
- continue;
- }
- samples = add_solution(samples, tab);
- init = 0;
- isl_tab_rollback(tab, snap[level]);
+ if (isl_basic_set_scan(bset, &ss.callback) < 0) {
+ isl_mat_free(ss.samples);
+ return NULL;
}
- isl_tab_free(tab);
- free(snap);
- isl_vec_free(min);
- isl_vec_free(max);
- isl_basic_set_free(bset);
- isl_mat_free(B);
- return samples;
+ return ss.samples;
error:
- isl_tab_free(tab);
- free(snap);
- isl_mat_free(samples);
- isl_vec_free(min);
- isl_vec_free(max);
isl_basic_set_free(bset);
- isl_mat_free(B);
return NULL;
}
+static struct isl_mat *isl_basic_set_samples(struct isl_basic_set *bset)
+{
+ struct isl_mat *T;
+ struct isl_mat *samples;
+
+ if (bset->n_eq == 0)
+ return isl_basic_set_scan_samples(bset);
+
+ bset = isl_basic_set_remove_equalities(bset, &T, NULL);
+ samples = isl_basic_set_scan_samples(bset);
+ return isl_mat_product(samples, isl_mat_transpose(T));
+}
+
int main(int argc, char **argv)
{
struct isl_ctx *ctx = isl_ctx_alloc();
struct isl_basic_set *bset;
struct isl_mat *samples;
- bset = isl_basic_set_read_from_file(ctx, stdin, 0, ISL_FORMAT_POLYLIB);
+ bset = isl_basic_set_read_from_file(ctx, stdin, 0);
samples = isl_basic_set_samples(bset);
isl_mat_dump(samples, stdout, 0);
isl_mat_free(samples);