isl_tab.c: add isl_tab_get_sample_value

2 files changed, 39 insertions, 0 deletions

diff --git a/isl_tab.c b/isl_tab.c
index 5ae619e4..6397e2f7 100644
--- a/isl_tab.c
+++ b/isl_tab.c
@@ -1100,6 +1100,42 @@ static struct isl_vec *extract_integer_sample(struct isl_ctx *ctx,
 	return vec;
 }
 
+struct isl_vec *isl_tab_get_sample_value(struct isl_ctx *ctx,
+						struct isl_tab *tab)
+{
+	int i;
+	struct isl_vec *vec;
+	isl_int m;
+
+	if (!tab)
+		return NULL;
+
+	vec = isl_vec_alloc(ctx, 1 + tab->n_var);
+	if (!vec)
+		return NULL;
+
+	isl_int_init(m);
+
+	isl_int_set_si(vec->block.data[0], 1);
+	for (i = 0; i < tab->n_var; ++i) {
+		int row;
+		if (!tab->var[i].is_row) {
+			isl_int_set_si(vec->block.data[1 + i], 0);
+			continue;
+		}
+		row = tab->var[i].index;
+		isl_int_gcd(m, vec->block.data[0], tab->mat->row[row][0]);
+		isl_int_divexact(m, tab->mat->row[row][0], m);
+		isl_seq_scale(vec->block.data, vec->block.data, m, 1 + i);
+		isl_int_divexact(m, vec->block.data[0], tab->mat->row[row][0]);
+		isl_int_mul(vec->block.data[1 + i], m, tab->mat->row[row][1]);
+	}
+	isl_seq_normalize(vec->block.data, vec->size);
+
+	isl_int_clear(m);
+	return vec;
+}
+
 /* Update "bmap" based on the results of the tableau "tab".
  * In particular, implicit equalities are made explicit, redundant constraints
  * are removed and if the sample value happens to be integer, it is stored
diff --git a/isl_tab.h b/isl_tab.h
index e3535f7e..e6231aac 100644
--- a/isl_tab.h
+++ b/isl_tab.h
@@ -118,6 +118,9 @@ struct isl_tab *isl_tab_add_ineq(struct isl_ctx *ctx,
 int isl_tab_is_equality(struct isl_ctx *ctx, struct isl_tab *tab, int con);
 int isl_tab_is_redundant(struct isl_ctx *ctx, struct isl_tab *tab, int con);
 
+struct isl_vec *isl_tab_get_sample_value(struct isl_ctx *ctx,
+						struct isl_tab *tab);
+
 enum isl_ineq_type {
 	isl_ineq_error = -1,
 	isl_ineq_redundant,