* @param irn The node.
* @param bl The block.
*/
-static unsigned compute_height(heights_t *h, const ir_node *irn, const ir_node *bl)
+static unsigned compute_height(heights_t *h, ir_node *irn, const ir_node *bl)
{
irn_height_t *ih = phase_get_or_set_irn_data(&h->ph, irn);
int is_sink;