isl_set_dim_residue_class: correctly consider all basic sets in the set

[platform/upstream/isl.git] / isl_tab_pip.c

diff --git a/isl_tab_pip.c b/isl_tab_pip.c
index 4764334..dd95d88 100644 (file)
--- a/isl_tab_pip.c
+++ b/isl_tab_pip.c
@@ -745,6 +745,30 @@ static struct isl_vec *get_row_parameter_ineq(struct isl_tab *tab, int row)
        return ineq;
 }
 
+/* Normalize a div expression of the form
+ *
+ *     [(g*f(x) + c)/(g * m)]
+ *
+ * with c the constant term and f(x) the remaining coefficients, to
+ *
+ *     [(f(x) + [c/g])/m]
+ */
+static void normalize_div(__isl_keep isl_vec *div)
+{
+       isl_ctx *ctx = isl_vec_get_ctx(div);
+       int len = div->size - 2;
+
+       isl_seq_gcd(div->el + 2, len, &ctx->normalize_gcd);
+       isl_int_gcd(ctx->normalize_gcd, ctx->normalize_gcd, div->el[0]);
+
+       if (isl_int_is_one(ctx->normalize_gcd))
+               return;
+
+       isl_int_divexact(div->el[0], div->el[0], ctx->normalize_gcd);
+       isl_int_fdiv_q(div->el[1], div->el[1], ctx->normalize_gcd);
+       isl_seq_scale_down(div->el + 2, div->el + 2, ctx->normalize_gcd, len);
+}
+
 /* Return a integer division for use in a parametric cut based on the given row.
  * In particular, let the parametric constant of the row be
  *
@@ -765,8 +789,8 @@ static struct isl_vec *get_row_parameter_div(struct isl_tab *tab, int row)
 
        isl_int_set(div->el[0], tab->mat->row[row][0]);
        get_row_parameter_line(tab, row, div->el + 1);
-       div = isl_vec_normalize(div);
        isl_seq_neg(div->el + 1, div->el + 1, div->size - 1);
+       normalize_div(div);
        isl_seq_fdiv_r(div->el + 1, div->el + 1, div->el[0], div->size - 1);
 
        return div;
@@ -793,7 +817,7 @@ static struct isl_vec *get_row_split_div(struct isl_tab *tab, int row)
 
        isl_int_set(div->el[0], tab->mat->row[row][0]);
        get_row_parameter_line(tab, row, div->el + 1);
-       div = isl_vec_normalize(div);
+       normalize_div(div);
        isl_seq_fdiv_r(div->el + 1, div->el + 1, div->el[0], div->size - 1);
 
        return div;
@@ -1153,8 +1177,8 @@ static int report_conflicting_constraint(struct isl_tab *tab, int con)
 
 /* Given a conflicting row in the tableau, report all constraints
  * involved in the row to the caller.  That is, the row itself
- * (if represents a constraint) and all constraint columns with
- * non-zero (and therefore negative) coefficient.
+ * (if it represents a constraint) and all constraint columns with
+ * non-zero (and therefore negative) coefficients.
  */
 static int report_conflict(struct isl_tab *tab, int row)
 {
@@ -1606,6 +1630,9 @@ static int add_cut(struct isl_tab *tab, int row)
        return tab->con[r].index;
 }
 
+#define CUT_ALL 1
+#define CUT_ONE 0
+
 /* Given a non-parametric tableau, add cuts until an integer
  * sample point is obtained or until the tableau is determined
  * to be integer infeasible.
@@ -1617,8 +1644,12 @@ static int add_cut(struct isl_tab *tab, int row)
  * combination of variables/constraints plus a non-integral constant,
  * then there is no way to obtain an integer point and we return
  * a tableau that is marked empty.
+ * The parameter cutting_strategy controls the strategy used when adding cuts
+ * to remove non-integer points. CUT_ALL adds all possible cuts
+ * before continuing the search. CUT_ONE adds only one cut at a time.
  */
-static struct isl_tab *cut_to_integer_lexmin(struct isl_tab *tab)
+static struct isl_tab *cut_to_integer_lexmin(struct isl_tab *tab,
+       int cutting_strategy)
 {
        int var;
        int row;
@@ -1640,6 +1671,8 @@ static struct isl_tab *cut_to_integer_lexmin(struct isl_tab *tab)
                        row = add_cut(tab, row);
                        if (row < 0)
                                goto error;
+                       if (cutting_strategy == CUT_ONE)
+                               break;
                } while ((var = next_non_integer_var(tab, var, &flags)) != -1);
                if (restore_lexmin(tab) < 0)
                        goto error;
@@ -1730,7 +1763,7 @@ static struct isl_tab *check_integer_feasible(struct isl_tab *tab)
        if (isl_tab_push_basis(tab) < 0)
                goto error;
 
-       tab = cut_to_integer_lexmin(tab);
+       tab = cut_to_integer_lexmin(tab, CUT_ALL);
        if (!tab)
                goto error;
 
@@ -4958,7 +4991,7 @@ __isl_give isl_vec *isl_tab_basic_set_non_trivial_lexmin(
                int side, base;
 
                if (init) {
-                       tab = cut_to_integer_lexmin(tab);
+                       tab = cut_to_integer_lexmin(tab, CUT_ONE);
                        if (!tab)
                                goto error;
                        if (tab->empty)