isl_union_set_compute_schedule: only carry validity dependences

If we are forced to try and carry come dependences because of some conflict,
then we only need to carry those dependences that may lead to a conflict.
That is, we only need to carry validity dependences.

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

diff --git a/isl_schedule.c b/isl_schedule.c
index 3e56153..0807fce 100644 (file)
--- a/isl_schedule.c
+++ b/isl_schedule.c
@@ -1042,8 +1042,8 @@ static int node_update_cmap(struct isl_sched_node *node)
 
 /* Count the number of equality and inequality constraints
  * that will be added for the given map.
- * If carry is set, then we are counting the number of constraints
- * that will be added in setup_carry_lp and we count
+ * If carry is set, then we are counting the number of (validity)
+ * constraints that will be added in setup_carry_lp and we count
  * each edge exactly once.  Otherwise, we count as follows
  * validity            -> 1 (>= 0)
  * validity+proximity  -> 2 (>= 0 and upper bound)
@@ -1056,6 +1056,11 @@ static int count_map_constraints(struct isl_sched_graph *graph,
        isl_basic_set *coef;
        int f = carry ? 1 : edge->proximity ? 2 : 1;
 
+       if (carry && !edge->validity) {
+               isl_map_free(map);
+               return 0;
+       }
+
        if (edge->src == edge->dst)
                coef = intra_coefficients(graph, map);
        else
@@ -2110,7 +2115,7 @@ static int add_inter_constraints(struct isl_sched_graph *graph,
        return 0;
 }
 
-/* Add constraints to graph->lp that force all dependences
+/* Add constraints to graph->lp that force all validity dependences
  * to be respected and attempt to carry them.
  */
 static int add_all_constraints(struct isl_sched_graph *graph)
@@ -2121,6 +2126,10 @@ static int add_all_constraints(struct isl_sched_graph *graph)
        pos = 0;
        for (i = 0; i < graph->n_edge; ++i) {
                struct isl_sched_edge *edge= &graph->edge[i];
+
+               if (!edge->validity)
+                       continue;
+
                for (j = 0; j < edge->map->n; ++j) {
                        isl_basic_map *bmap;
                        isl_map *map;
@@ -2198,7 +2207,7 @@ static int count_all_constraints(struct isl_sched_graph *graph,
  *             - positive and negative parts of c_i_n (if parametric)
  *             - positive and negative parts of c_i_x
  *
- * The constraints are those from the edges plus three equalities
+ * The constraints are those from the (validity) edges plus three equalities
  * to express the sums and n_edge inequalities to express e_i <= 1.
  */
 static int setup_carry_lp(isl_ctx *ctx, struct isl_sched_graph *graph)