/* Add a specific constraint of bmap (or its opposite) to tab.
 * The position of the constraint is specified by "c", where
 * the equalities of bmap are counted twice, once for the inequality
 * that is equal to the equality, and once for its negation.
 *
 * Each of these constraints has been added to "tab" before by
 * tab_add_constraints (and later removed again), so there should
 * already be a row available for the constraint.
 */
static int tab_add_constraint(struct isl_tab *tab,
	__isl_keep isl_basic_map *bmap, int *div_map, int c, int oppose)
{
	unsigned dim;
	unsigned tab_total;
	unsigned bmap_total;
	isl_vec *v;
	int r;

	if (!tab || !bmap)
		return -1;

	tab_total = isl_basic_map_total_dim(tab->bmap);
	bmap_total = isl_basic_map_total_dim(bmap);
	dim = isl_space_dim(tab->bmap->dim, isl_dim_all);

	v = isl_vec_alloc(bmap->ctx, 1 + tab_total);
	if (!v)
		return -1;

	if (c < 2 * bmap->n_eq) {
		if ((c % 2) != oppose)
			isl_seq_neg(bmap->eq[c/2], bmap->eq[c/2],
					1 + bmap_total);
		if (oppose)
			isl_int_sub_ui(bmap->eq[c/2][0], bmap->eq[c/2][0], 1);
		expand_constraint(v, dim, bmap->eq[c/2], div_map, bmap->n_div);
		r = isl_tab_add_ineq(tab, v->el);
		if (oppose)
			isl_int_add_ui(bmap->eq[c/2][0], bmap->eq[c/2][0], 1);
		if ((c % 2) != oppose)
			isl_seq_neg(bmap->eq[c/2], bmap->eq[c/2],
					1 + bmap_total);
	} else {
		c -= 2 * bmap->n_eq;
		if (oppose) {
			isl_seq_neg(bmap->ineq[c], bmap->ineq[c],
					1 + bmap_total);
			isl_int_sub_ui(bmap->ineq[c][0], bmap->ineq[c][0], 1);
		}
		expand_constraint(v, dim, bmap->ineq[c], div_map, bmap->n_div);
		r = isl_tab_add_ineq(tab, v->el);
		if (oppose) {
			isl_int_add_ui(bmap->ineq[c][0], bmap->ineq[c][0], 1);
			isl_seq_neg(bmap->ineq[c], bmap->ineq[c],
					1 + bmap_total);
		}
	}

	isl_vec_free(v);
	return r;
}
示例#2
0
static int increment_range(struct isl_scan_callback *cb, isl_int min, isl_int max)
{
	struct isl_counter *cnt = (struct isl_counter *)cb;

	isl_int_add(cnt->count, cnt->count, max);
	isl_int_sub(cnt->count, cnt->count, min);
	isl_int_add_ui(cnt->count, cnt->count, 1);

	if (isl_int_is_zero(cnt->max) || isl_int_lt(cnt->count, cnt->max))
		return 0;
	isl_int_set(cnt->count, cnt->max);
	return -1;
}
示例#3
0
static int increment_counter(struct isl_scan_callback *cb,
	__isl_take isl_vec *sample)
{
	struct isl_counter *cnt = (struct isl_counter *)cb;

	isl_int_add_ui(cnt->count, cnt->count, 1);

	isl_vec_free(sample);

	if (isl_int_is_zero(cnt->max) || isl_int_lt(cnt->count, cnt->max))
		return 0;
	return -1;
}
示例#4
0
/* Find an integer point in the set represented by "tab"
 * that lies outside of the equality "eq" e(x) = 0.
 * If "up" is true, look for a point satisfying e(x) - 1 >= 0.
 * Otherwise, look for a point satisfying -e(x) - 1 >= 0 (i.e., e(x) <= -1).
 * The point, if found, is returned.
 * If no point can be found, a zero-length vector is returned.
 *
 * Before solving an ILP problem, we first check if simply
 * adding the normal of the constraint to one of the known
 * integer points in the basic set represented by "tab"
 * yields another point inside the basic set.
 *
 * The caller of this function ensures that the tableau is bounded or
 * that tab->basis and tab->n_unbounded have been set appropriately.
 */
static struct isl_vec *outside_point(struct isl_tab *tab, isl_int *eq, int up)
{
	struct isl_ctx *ctx;
	struct isl_vec *sample = NULL;
	struct isl_tab_undo *snap;
	unsigned dim;

	if (!tab)
		return NULL;
	ctx = tab->mat->ctx;

	dim = tab->n_var;
	sample = isl_vec_alloc(ctx, 1 + dim);
	if (!sample)
		return NULL;
	isl_int_set_si(sample->el[0], 1);
	isl_seq_combine(sample->el + 1,
		ctx->one, tab->bmap->sample->el + 1,
		up ? ctx->one : ctx->negone, eq + 1, dim);
	if (isl_basic_map_contains(tab->bmap, sample))
		return sample;
	isl_vec_free(sample);
	sample = NULL;

	snap = isl_tab_snap(tab);

	if (!up)
		isl_seq_neg(eq, eq, 1 + dim);
	isl_int_sub_ui(eq[0], eq[0], 1);

	if (isl_tab_extend_cons(tab, 1) < 0)
		goto error;
	if (isl_tab_add_ineq(tab, eq) < 0)
		goto error;

	sample = isl_tab_sample(tab);

	isl_int_add_ui(eq[0], eq[0], 1);
	if (!up)
		isl_seq_neg(eq, eq, 1 + dim);

	if (sample && isl_tab_rollback(tab, snap) < 0)
		goto error;

	return sample;
error:
	isl_vec_free(sample);
	return NULL;
}
示例#5
0
__isl_give isl_point *isl_point_add_ui(__isl_take isl_point *pnt,
	enum isl_dim_type type, int pos, unsigned val)
{
	if (!pnt || isl_point_is_void(pnt))
		return pnt;

	pnt = isl_point_cow(pnt);
	if (!pnt)
		return NULL;
	pnt->vec = isl_vec_cow(pnt->vec);
	if (!pnt->vec)
		goto error;

	if (type == isl_dim_set)
		pos += isl_dim_size(pnt->dim, isl_dim_param);

	isl_int_add_ui(pnt->vec->el[1 + pos], pnt->vec->el[1 + pos], val);

	return pnt;
error:
	isl_point_free(pnt);
	return NULL;
}
示例#6
0
/* Look for all integer points in "bset", which is assumed to be bounded,
 * and call callback->add on each of them.
 *
 * 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.
 */
int isl_basic_set_scan(struct isl_basic_set *bset,
	struct isl_scan_callback *callback)
{
	unsigned dim;
	struct isl_mat *B = NULL;
	struct isl_tab *tab = NULL;
	struct isl_vec *min;
	struct isl_vec *max;
	struct isl_tab_undo **snap;
	int level;
	int init;
	enum isl_lp_result res;

	if (!bset)
		return -1;

	dim = isl_basic_set_total_dim(bset);
	if (dim == 0)
		return scan_0D(bset, callback);

	min = isl_vec_alloc(bset->ctx, dim);
	max = isl_vec_alloc(bset->ctx, dim);
	snap = isl_alloc_array(bset->ctx, struct isl_tab_undo *, dim);

	if (!min || !max || !snap)
		goto error;

	tab = isl_tab_from_basic_set(bset, 0);
	if (!tab)
		goto error;
	if (isl_tab_extend_cons(tab, dim + 1) < 0)
		goto error;

	tab->basis = isl_mat_identity(bset->ctx, 1 + dim);
	if (1)
		tab = isl_tab_compute_reduced_basis(tab);
	if (!tab)
		goto error;
	B = isl_mat_copy(tab->basis);
	if (!B)
		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)
				if (isl_tab_rollback(tab, snap[level]) < 0)
					goto error;
			continue;
		}
		if (level == dim - 1 && callback->add == increment_counter) {
			if (increment_range(callback,
					    min->el[level], max->el[level]))
				goto error;
			level--;
			init = 0;
			if (level >= 0)
				if (isl_tab_rollback(tab, snap[level]) < 0)
					goto error;
			continue;
		}
		isl_int_neg(B->row[1 + level][0], min->el[level]);
		if (isl_tab_add_valid_eq(tab, B->row[1 + level]) < 0)
			goto error;
		isl_int_set_si(B->row[1 + level][0], 0);
		if (level < dim - 1) {
			++level;
			init = 1;
			continue;
		}
		if (add_solution(tab, callback) < 0)
			goto error;
		init = 0;
		if (isl_tab_rollback(tab, snap[level]) < 0)
			goto error;
	}

	isl_tab_free(tab);
	free(snap);
	isl_vec_free(min);
	isl_vec_free(max);
	isl_basic_set_free(bset);
	isl_mat_free(B);
	return 0;
error:
	isl_tab_free(tab);
	free(snap);
	isl_vec_free(min);
	isl_vec_free(max);
	isl_basic_set_free(bset);
	isl_mat_free(B);
	return -1;
}