export isl_basic_set_reduced_basis

Since this function will now be available from the outside, we
add some more checks and we allow the input to contain equalities.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/basis_reduction_templ.c b/basis_reduction_templ.c
index 305431f..375549d 100644 (file)
--- a/basis_reduction_templ.c
+++ b/basis_reduction_templ.c
@@ -302,15 +302,46 @@ error:
        return tab;
 }
 
+/* Compute an affine form of a reduced basis of the given basic
+ * non-parametric set, which is assumed to be bounded and not
+ * include any integer divisions.
+ * The first column and the first row correspond to the constant term.
+ *
+ * If the input contains any equalities, we first create an initial
+ * basis with the equalities first.  Otherwise, we start off with
+ * the identity matrix.
+ */
 struct isl_mat *isl_basic_set_reduced_basis(struct isl_basic_set *bset)
 {
        struct isl_mat *basis;
        struct isl_tab *tab;
 
-       isl_assert(bset->ctx, bset->n_eq == 0, return NULL);
+       if (!bset)
+               return NULL;
+
+       if (isl_basic_set_dim(bset, isl_dim_div) != 0)
+               isl_die(bset->ctx, isl_error_invalid,
+                       "no integer division allowed", return NULL);
+       if (isl_basic_set_dim(bset, isl_dim_param) != 0)
+               isl_die(bset->ctx, isl_error_invalid,
+                       "no parameters allowed", return NULL);
 
        tab = isl_tab_from_basic_set(bset);
-       tab->basis = isl_mat_identity(bset->ctx, 1 + tab->n_var);
+       if (!tab)
+               return NULL;
+
+       if (bset->n_eq == 0)
+               tab->basis = isl_mat_identity(bset->ctx, 1 + tab->n_var);
+       else {
+               isl_mat *eq;
+               unsigned nvar = isl_basic_set_total_dim(bset);
+               eq = isl_mat_sub_alloc(bset->ctx, bset->eq, 0, bset->n_eq,
+                                       1, nvar);
+               eq = isl_mat_left_hermite(eq, 0, NULL, &tab->basis);
+               tab->basis = isl_mat_lin_to_aff(tab->basis);
+               tab->n_zero = bset->n_eq;
+               isl_mat_free(eq);
+       }
        tab = isl_tab_compute_reduced_basis(tab);
        if (!tab)
                return NULL;

diff --git a/include/isl_set.h b/include/isl_set.h
index 4e8f725..c978d38 100644 (file)
--- a/include/isl_set.h
+++ b/include/isl_set.h
@@ -374,6 +374,8 @@ __isl_give isl_basic_set *isl_basic_set_from_constraint_matrices(
        __isl_take isl_mat *eq, __isl_take isl_mat *ineq, enum isl_dim_type c1,
        enum isl_dim_type c2, enum isl_dim_type c3, enum isl_dim_type c4);
 
+__isl_give isl_mat *isl_basic_set_reduced_basis(__isl_keep isl_basic_set *bset);
+
 #if defined(__cplusplus)
 }
 #endif

diff --git a/isl_basis_reduction.h b/isl_basis_reduction.h
index e9eb760..9b9b721 100644 (file)
--- a/isl_basis_reduction.h
+++ b/isl_basis_reduction.h
@@ -19,7 +19,6 @@ extern "C" {
 #endif
 
 struct isl_tab *isl_tab_compute_reduced_basis(struct isl_tab *tab);
-struct isl_mat *isl_basic_set_reduced_basis(struct isl_basic_set *bset);
 
 #if defined(__cplusplus)
 }