+/*
+ * 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 <isl_ctx_private.h>
+#include <isl_map_private.h>
#include "isl_sample.h"
#include "isl_sample_piplib.h"
-#include "isl_vec.h"
-#include "isl_mat.h"
-#include "isl_seq.h"
-#include "isl_map_private.h"
+#include <isl/vec.h>
+#include <isl/mat.h>
+#include <isl/seq.h>
#include "isl_equalities.h"
#include "isl_tab.h"
#include "isl_basis_reduction.h"
+#include <isl_factorization.h>
+#include <isl_point_private.h>
static struct isl_vec *empty_sample(struct isl_basic_set *bset)
{
return zero_sample(bset);
sample = isl_vec_alloc(bset->ctx, 2);
+ if (!sample)
+ goto error;
+ if (!bset)
+ return NULL;
isl_int_set_si(sample->block.data[0], 1);
if (bset->n_eq > 0) {
if (!tab)
return NULL;
- isl_assert(tab->mat->ctx, tab->bset, return NULL);
- bset = tab->bset;
+ bset = isl_tab_peek_bset(tab);
+ isl_assert(tab->mat->ctx, bset, return NULL);
n_eq = tab->n_var - tab->n_col + tab->n_dead;
if (tab->empty || n_eq == 0)
struct isl_mat *eq;
struct isl_mat *Q;
- n_eq = tab->n_var - tab->n_col + tab->n_dead;
+ tab->n_unbounded = 0;
+ tab->n_zero = n_eq = tab->n_var - tab->n_col + tab->n_dead;
if (tab->empty || n_eq == 0 || n_eq == tab->n_var)
return isl_mat_identity(tab->mat->ctx, 1 + tab->n_var);
*
* The initial basis is the identity matrix. If the range in some direction
* contains more than one integer value, we perform basis reduction based
- * on the value of ctx->gbr
+ * on the value of ctx->opt->gbr
* - ISL_GBR_NEVER: never perform basis reduction
* - ISL_GBR_ONCE: only perform basis reduction the first
* time such a range is encountered
* - ISL_GBR_ALWAYS: always perform basis reduction when
* such a range is encountered
*
- * When ctx->gbr is set to ISL_GBR_ALWAYS, then we allow the basis
+ * When ctx->opt->gbr is set to ISL_GBR_ALWAYS, then we allow the basis
* reduction computation to return early. That is, as soon as it
* finds a reasonable first direction.
*/
ctx = tab->mat->ctx;
dim = tab->n_var;
- gbr = ctx->gbr;
+ gbr = ctx->opt->gbr;
if (tab->n_unbounded == tab->n_var) {
sample = isl_tab_get_sample_value(tab);
goto error;
if (!empty && isl_tab_sample_is_integer(tab))
break;
- if (!empty && !reduced && ctx->gbr != ISL_GBR_NEVER &&
+ if (!empty && !reduced &&
+ ctx->opt->gbr != ISL_GBR_NEVER &&
isl_int_lt(min->el[level], max->el[level])) {
unsigned gbr_only_first;
- if (ctx->gbr == ISL_GBR_ONCE)
- ctx->gbr = ISL_GBR_NEVER;
+ if (ctx->opt->gbr == ISL_GBR_ONCE)
+ ctx->opt->gbr = ISL_GBR_NEVER;
tab->n_zero = level;
- gbr_only_first = ctx->gbr_only_first;
- ctx->gbr_only_first =
- ctx->gbr == ISL_GBR_ALWAYS;
+ gbr_only_first = ctx->opt->gbr_only_first;
+ ctx->opt->gbr_only_first =
+ ctx->opt->gbr == ISL_GBR_ALWAYS;
tab = isl_tab_compute_reduced_basis(tab);
- ctx->gbr_only_first = gbr_only_first;
+ ctx->opt->gbr_only_first = gbr_only_first;
if (!tab || !tab->basis)
goto error;
reduced = 1;
level--;
init = 0;
if (level >= 0)
- isl_tab_rollback(tab, snap[level]);
+ if (isl_tab_rollback(tab, snap[level]) < 0)
+ goto error;
continue;
}
isl_int_neg(tab->basis->row[1 + level][0], min->el[level]);
- tab = isl_tab_add_valid_eq(tab, tab->basis->row[1 + level]);
+ if (isl_tab_add_valid_eq(tab, tab->basis->row[1 + level]) < 0)
+ goto error;
isl_int_set_si(tab->basis->row[1 + level][0], 0);
if (level + tab->n_unbounded < dim - 1) {
++level;
} else
sample = isl_vec_alloc(ctx, 0);
- ctx->gbr = gbr;
+ ctx->opt->gbr = gbr;
isl_vec_free(min);
isl_vec_free(max);
free(snap);
return sample;
error:
- ctx->gbr = gbr;
+ ctx->opt->gbr = gbr;
isl_vec_free(min);
isl_vec_free(max);
free(snap);
return NULL;
}
+static struct isl_vec *sample_bounded(struct isl_basic_set *bset);
+
+/* Compute a sample point of the given basic set, based on the given,
+ * non-trivial factorization.
+ */
+static __isl_give isl_vec *factored_sample(__isl_take isl_basic_set *bset,
+ __isl_take isl_factorizer *f)
+{
+ int i, n;
+ isl_vec *sample = NULL;
+ isl_ctx *ctx;
+ unsigned nparam;
+ unsigned nvar;
+
+ ctx = isl_basic_set_get_ctx(bset);
+ if (!ctx)
+ goto error;
+
+ nparam = isl_basic_set_dim(bset, isl_dim_param);
+ nvar = isl_basic_set_dim(bset, isl_dim_set);
+
+ sample = isl_vec_alloc(ctx, 1 + isl_basic_set_total_dim(bset));
+ if (!sample)
+ goto error;
+ isl_int_set_si(sample->el[0], 1);
+
+ bset = isl_morph_basic_set(isl_morph_copy(f->morph), bset);
+
+ for (i = 0, n = 0; i < f->n_group; ++i) {
+ isl_basic_set *bset_i;
+ isl_vec *sample_i;
+
+ bset_i = isl_basic_set_copy(bset);
+ bset_i = isl_basic_set_drop_constraints_involving(bset_i,
+ nparam + n + f->len[i], nvar - n - f->len[i]);
+ bset_i = isl_basic_set_drop_constraints_involving(bset_i,
+ nparam, n);
+ bset_i = isl_basic_set_drop(bset_i, isl_dim_set,
+ n + f->len[i], nvar - n - f->len[i]);
+ bset_i = isl_basic_set_drop(bset_i, isl_dim_set, 0, n);
+
+ sample_i = sample_bounded(bset_i);
+ if (!sample_i)
+ goto error;
+ if (sample_i->size == 0) {
+ isl_basic_set_free(bset);
+ isl_factorizer_free(f);
+ isl_vec_free(sample);
+ return sample_i;
+ }
+ isl_seq_cpy(sample->el + 1 + nparam + n,
+ sample_i->el + 1, f->len[i]);
+ isl_vec_free(sample_i);
+
+ n += f->len[i];
+ }
+
+ f->morph = isl_morph_inverse(f->morph);
+ sample = isl_morph_vec(isl_morph_copy(f->morph), sample);
+
+ isl_basic_set_free(bset);
+ isl_factorizer_free(f);
+ return sample;
+error:
+ isl_basic_set_free(bset);
+ isl_factorizer_free(f);
+ isl_vec_free(sample);
+ return NULL;
+}
+
/* Given a basic set that is known to be bounded, find and return
* an integer point in the basic set, if there is any.
*
struct isl_ctx *ctx;
struct isl_vec *sample;
struct isl_tab *tab = NULL;
+ isl_factorizer *f;
if (!bset)
return NULL;
if (bset->n_eq > 0)
return sample_eq(bset, sample_bounded);
+ f = isl_basic_set_factorizer(bset);
+ if (!f)
+ goto error;
+ if (f->n_group != 0)
+ return factored_sample(bset, f);
+ isl_factorizer_free(f);
+
ctx = bset->ctx;
tab = isl_tab_from_basic_set(bset);
- if (!ISL_F_ISSET(bset, ISL_BASIC_SET_NO_IMPLICIT))
- tab = isl_tab_detect_implicit_equalities(tab);
- if (!tab)
- goto error;
+ if (tab && tab->empty) {
+ isl_tab_free(tab);
+ ISL_F_SET(bset, ISL_BASIC_SET_EMPTY);
+ sample = isl_vec_alloc(bset->ctx, 0);
+ isl_basic_set_free(bset);
+ return sample;
+ }
- tab->bset = isl_basic_set_copy(bset);
+ if (isl_tab_track_bset(tab, isl_basic_set_copy(bset)) < 0)
+ goto error;
+ if (!ISL_F_ISSET(bset, ISL_BASIC_SET_NO_IMPLICIT))
+ if (isl_tab_detect_implicit_equalities(tab) < 0)
+ goto error;
sample = isl_tab_sample(tab);
if (!sample)
total = isl_basic_set_total_dim(cone);
cone = isl_basic_set_preimage(cone, U);
- cone = isl_basic_set_remove_dims(cone, 0, total - (vec->size - 1));
+ cone = isl_basic_set_remove_dims(cone, isl_dim_set,
+ 0, total - (vec->size - 1));
cone = shift_cone(cone, vec);
return NULL;
}
-/* Drop all constraints in bset that involve any of the dimensions
- * first to first+n-1.
- */
-static struct isl_basic_set *drop_constraints_involving
- (struct isl_basic_set *bset, unsigned first, unsigned n)
-{
- int i;
-
- if (!bset)
- return NULL;
-
- bset = isl_basic_set_cow(bset);
-
- for (i = bset->n_ineq - 1; i >= 0; --i) {
- if (isl_seq_first_non_zero(bset->ineq[i] + 1 + first, n) == -1)
- continue;
- isl_basic_set_drop_inequality(bset, i);
- }
-
- return bset;
-}
-
/* Give a basic set "bset" with recession cone "cone", compute and
* return an integer point in bset, if any.
*
total = isl_basic_set_total_dim(cone);
cone_dim = total - cone->n_eq;
- M = isl_mat_sub_alloc(bset->ctx, cone->eq, 0, cone->n_eq, 1, total);
+ M = isl_mat_sub_alloc6(bset->ctx, cone->eq, 0, cone->n_eq, 1, total);
M = isl_mat_left_hermite(M, 0, &U, NULL);
if (!M)
goto error;
bset = isl_basic_set_preimage(bset, isl_mat_copy(U));
bounded = isl_basic_set_copy(bset);
- bounded = drop_constraints_involving(bounded, total - cone_dim, cone_dim);
+ bounded = isl_basic_set_drop_constraints_involving(bounded,
+ total - cone_dim, cone_dim);
bounded = isl_basic_set_drop_dims(bounded, total - cone_dim, cone_dim);
sample = sample_bounded(bounded);
if (!sample || sample->size == 0) {
return NULL;
}
+static void vec_sum_of_neg(struct isl_vec *v, isl_int *s)
+{
+ int i;
+
+ isl_int_set_si(*s, 0);
+
+ for (i = 0; i < v->size; ++i)
+ if (isl_int_is_neg(v->el[i]))
+ isl_int_add(*s, *s, v->el[i]);
+}
+
+/* Given a tableau "tab", a tableau "tab_cone" that corresponds
+ * to the recession cone and the inverse of a new basis U = inv(B),
+ * with the unbounded directions in B last,
+ * add constraints to "tab" that ensure any rational value
+ * in the unbounded directions can be rounded up to an integer value.
+ *
+ * The new basis is given by x' = B x, i.e., x = U x'.
+ * For any rational value of the last tab->n_unbounded coordinates
+ * in the update tableau, the value that is obtained by rounding
+ * up this value should be contained in the original tableau.
+ * For any constraint "a x + c >= 0", we therefore need to add
+ * a constraint "a x + c + s >= 0", with s the sum of all negative
+ * entries in the last elements of "a U".
+ *
+ * Since we are not interested in the first entries of any of the "a U",
+ * we first drop the columns of U that correpond to bounded directions.
+ */
+static int tab_shift_cone(struct isl_tab *tab,
+ struct isl_tab *tab_cone, struct isl_mat *U)
+{
+ int i;
+ isl_int v;
+ struct isl_basic_set *bset = NULL;
+
+ if (tab && tab->n_unbounded == 0) {
+ isl_mat_free(U);
+ return 0;
+ }
+ isl_int_init(v);
+ if (!tab || !tab_cone || !U)
+ goto error;
+ bset = isl_tab_peek_bset(tab_cone);
+ U = isl_mat_drop_cols(U, 0, tab->n_var - tab->n_unbounded);
+ for (i = 0; i < bset->n_ineq; ++i) {
+ int ok;
+ struct isl_vec *row = NULL;
+ if (isl_tab_is_equality(tab_cone, tab_cone->n_eq + i))
+ continue;
+ row = isl_vec_alloc(bset->ctx, tab_cone->n_var);
+ if (!row)
+ goto error;
+ isl_seq_cpy(row->el, bset->ineq[i] + 1, tab_cone->n_var);
+ row = isl_vec_mat_product(row, isl_mat_copy(U));
+ if (!row)
+ goto error;
+ vec_sum_of_neg(row, &v);
+ isl_vec_free(row);
+ if (isl_int_is_zero(v))
+ continue;
+ tab = isl_tab_extend(tab, 1);
+ isl_int_add(bset->ineq[i][0], bset->ineq[i][0], v);
+ ok = isl_tab_add_ineq(tab, bset->ineq[i]) >= 0;
+ isl_int_sub(bset->ineq[i][0], bset->ineq[i][0], v);
+ if (!ok)
+ goto error;
+ }
+
+ isl_mat_free(U);
+ isl_int_clear(v);
+ return 0;
+error:
+ isl_mat_free(U);
+ isl_int_clear(v);
+ return -1;
+}
+
+/* Compute and return an initial basis for the possibly
+ * unbounded tableau "tab". "tab_cone" is a tableau
+ * for the corresponding recession cone.
+ * Additionally, add constraints to "tab" that ensure
+ * that any rational value for the unbounded directions
+ * can be rounded up to an integer value.
+ *
+ * If the tableau is bounded, i.e., if the recession cone
+ * is zero-dimensional, then we just use inital_basis.
+ * Otherwise, we construct a basis whose first directions
+ * correspond to equalities, followed by bounded directions,
+ * i.e., equalities in the recession cone.
+ * The remaining directions are then unbounded.
+ */
+int isl_tab_set_initial_basis_with_cone(struct isl_tab *tab,
+ struct isl_tab *tab_cone)
+{
+ struct isl_mat *eq;
+ struct isl_mat *cone_eq;
+ struct isl_mat *U, *Q;
+
+ if (!tab || !tab_cone)
+ return -1;
+
+ if (tab_cone->n_col == tab_cone->n_dead) {
+ tab->basis = initial_basis(tab);
+ return tab->basis ? 0 : -1;
+ }
+
+ eq = tab_equalities(tab);
+ if (!eq)
+ return -1;
+ tab->n_zero = eq->n_row;
+ cone_eq = tab_equalities(tab_cone);
+ eq = isl_mat_concat(eq, cone_eq);
+ if (!eq)
+ return -1;
+ tab->n_unbounded = tab->n_var - (eq->n_row - tab->n_zero);
+ eq = isl_mat_left_hermite(eq, 0, &U, &Q);
+ if (!eq)
+ return -1;
+ isl_mat_free(eq);
+ tab->basis = isl_mat_lin_to_aff(Q);
+ if (tab_shift_cone(tab, tab_cone, U) < 0)
+ return -1;
+ if (!tab->basis)
+ return -1;
+ return 0;
+}
+
/* Compute and return a sample point in bset using generalized basis
* reduction. We first check if the input set has a non-trivial
* recession cone. If so, we perform some extra preprocessing in
dim = isl_basic_set_total_dim(bset);
cone = isl_basic_set_recession_cone(isl_basic_set_copy(bset));
+ if (!cone)
+ goto error;
if (cone->n_eq < dim)
return isl_basic_set_sample_with_cone(bset, cone);
isl_basic_set_free(cone);
return sample_bounded(bset);
+error:
+ isl_basic_set_free(bset);
+ return NULL;
}
static struct isl_vec *pip_sample(struct isl_basic_set *bset)
if (dim == 1)
return interval_sample(bset);
- switch (bset->ctx->ilp_solver) {
+ switch (bset->ctx->opt->ilp_solver) {
case ISL_ILP_PIP:
return pip_sample(bset);
case ISL_ILP_GBR:
isl_int_neg(bset->eq[k][0], vec->el[1 + i]);
isl_int_set(bset->eq[k][1 + i], vec->el[0]);
}
- isl_vec_free(vec);
+ bset->sample = vec;
return bset;
error:
{
return (isl_basic_set *) isl_map_sample((isl_map *)set);
}
+
+__isl_give isl_point *isl_basic_set_sample_point(__isl_take isl_basic_set *bset)
+{
+ isl_vec *vec;
+ isl_dim *dim;
+
+ dim = isl_basic_set_get_dim(bset);
+ bset = isl_basic_set_underlying_set(bset);
+ vec = isl_basic_set_sample_vec(bset);
+
+ return isl_point_alloc(dim, vec);
+}
+
+__isl_give isl_point *isl_set_sample_point(__isl_take isl_set *set)
+{
+ int i;
+ isl_point *pnt;
+
+ if (!set)
+ return NULL;
+
+ for (i = 0; i < set->n; ++i) {
+ pnt = isl_basic_set_sample_point(isl_basic_set_copy(set->p[i]));
+ if (!pnt)
+ goto error;
+ if (!isl_point_is_void(pnt))
+ break;
+ isl_point_free(pnt);
+ }
+ if (i == set->n)
+ pnt = isl_point_void(isl_set_get_dim(set));
+
+ isl_set_free(set);
+ return pnt;
+error:
+ isl_set_free(set);
+ return NULL;
+}
projects / platform / upstream / isl.git / blobdiff