isl_tab_sample: extract out compute_min and compute_max

We will be able to reuse them in the next commit.

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

diff --git a/isl_sample.c b/isl_sample.c
index d9cdc00..6fcec27 100644 (file)
--- a/isl_sample.c
+++ b/isl_sample.c
@@ -347,6 +347,36 @@ static struct isl_mat *initial_basis(struct isl_tab *tab)
        return Q;
 }
 
+/* Compute the minimum of the current ("level") basis row over "tab"
+ * and store the result in position "level" of "min".
+ */
+static enum isl_lp_result compute_min(isl_ctx *ctx, struct isl_tab *tab,
+       __isl_keep isl_vec *min, int level)
+{
+       return isl_tab_min(tab, tab->basis->row[1 + level],
+                           ctx->one, &min->el[level], NULL, 0);
+}
+
+/* Compute the maximum of the current ("level") basis row over "tab"
+ * and store the result in position "level" of "max".
+ */
+static enum isl_lp_result compute_max(isl_ctx *ctx, struct isl_tab *tab,
+       __isl_keep isl_vec *max, int level)
+{
+       enum isl_lp_result res;
+       unsigned dim = tab->n_var;
+
+       isl_seq_neg(tab->basis->row[1 + level] + 1,
+                   tab->basis->row[1 + level] + 1, dim);
+       res = isl_tab_min(tab, tab->basis->row[1 + level],
+                   ctx->one, &max->el[level], NULL, 0);
+       isl_seq_neg(tab->basis->row[1 + level] + 1,
+                   tab->basis->row[1 + level] + 1, dim);
+       isl_int_neg(max->el[level], max->el[level]);
+
+       return res;
+}
+
 /* Given a tableau representing a set, find and return
  * an integer point in the set, if there is any.
  *
@@ -456,8 +486,7 @@ struct isl_vec *isl_tab_sample(struct isl_tab *tab)
 
        while (level >= 0) {
                if (init) {
-                       res = isl_tab_min(tab, tab->basis->row[1 + level],
-                                   ctx->one, &min->el[level], NULL, 0);
+                       res = compute_min(ctx, tab, min, level);
                        if (res == isl_lp_error)
                                goto error;
                        if (res != isl_lp_ok)
@@ -466,13 +495,7 @@ struct isl_vec *isl_tab_sample(struct isl_tab *tab)
                                        goto error);
                        if (isl_tab_sample_is_integer(tab))
                                break;
-                       isl_seq_neg(tab->basis->row[1 + level] + 1,
-                                   tab->basis->row[1 + level] + 1, dim);
-                       res = isl_tab_min(tab, tab->basis->row[1 + level],
-                                   ctx->one, &max->el[level], NULL, 0);
-                       isl_seq_neg(tab->basis->row[1 + level] + 1,
-                                   tab->basis->row[1 + level] + 1, dim);
-                       isl_int_neg(max->el[level], max->el[level]);
+                       res = compute_max(ctx, tab, max, level);
                        if (res == isl_lp_error)
                                goto error;
                        if (res != isl_lp_ok)