consider node latency now when sorting nodes for scheduling

diff --git a/ir/be/beilpsched.c b/ir/be/beilpsched.c
index 4065e95..5b2abc9 100644 (file)
--- a/ir/be/beilpsched.c
+++ b/ir/be/beilpsched.c
@@ -71,6 +71,7 @@ typedef struct _ilp_var_types_t {
 typedef struct _ilpsched_node_attr_t {
        unsigned asap;                     /**< The ASAP scheduling control step */
        unsigned alap;                     /**< The ALAP scheduling control step */
+       unsigned latency;                  /**< Latency of this node (needed for sorting) */
        unsigned sched_point;              /**< the step in which the node is finally scheduled */
        unsigned visit_idx;                /**< Index of the node having visited this node last */
        unsigned consumer_idx;             /**< Index of the node having counted this node as consumer last */
@@ -235,7 +236,12 @@ static int cmp_ilpsched_irn(const void *a, const void *b) {
                        return 1;
                if (heights_reachable_in_block(glob_heights, irn_b, irn_a))
                        return -1;
-               return 0;
+
+               /*
+                       Ok, timestep is equal and the nodes are parallel,
+                       so check latency and schedule high latency first.
+               */
+               return QSORT_CMP(n2_a->latency, n1_a->latency);
        }
        else
                return QSORT_CMP(n1_a->sched_point, n2_a->sched_point);
@@ -471,8 +477,9 @@ static void calculate_irn_asap(ir_node *irn, void *walk_env) {
                        ilpsched_node_attr_t *pna       = get_ilpsched_node_attr(pred_node);
                        unsigned             lat;
 
-                       lat      = fixed_latency(env->sel, pred, env->block_env);
-                       na->asap = MAX(na->asap, pna->asap + lat);
+                       lat         = fixed_latency(env->sel, pred, env->block_env);
+                       na->latency = lat;
+                       na->asap    = MAX(na->asap, pna->asap + lat);
                }
        }