bugfix: update_scc() must mark already seen SCC nodes, else a node might be put more...

once into the SCC (causing an endless loop in the linked list ...)

[r17822]

diff --git a/ir/opt/opt_osr.c b/ir/opt/opt_osr.c
index 60cce6f..f7af05a 100644 (file)
--- a/ir/opt/opt_osr.c
+++ b/ir/opt/opt_osr.c
@@ -409,6 +409,7 @@ static void update_scc(ir_node *iv, node_entry *e, iv_env *env) {
        ir_node *header = e->header;
        waitq    *wq = new_waitq();
 
+       DB((dbg, LEVEL_2, "  Creating SCC for new an induction variable:\n  "));
        pscc->head = NULL;
        waitq_put(wq, iv);
        do {
@@ -419,16 +420,21 @@ static void update_scc(ir_node *iv, node_entry *e, iv_env *env) {
                ne->pscc   = pscc;
                ne->next   = pscc->head;
                pscc->head = irn;
+               DB((dbg, LEVEL_2, " %+F,", irn));
 
                for (i = get_irn_arity(irn) - 1; i >= 0; --i) {
                        ir_node    *pred = get_irn_n(irn, i);
                        node_entry *pe   = get_irn_ne(pred, env);
 
-                       if (pe->header == header && pe->pscc == NULL)
+                       if (pe->header == header && pe->pscc == NULL) {
+                               /* set the psc here to ensure that the node is NOT enqueued another time */
+                               pe->pscc = pscc;
                                waitq_put(wq, pred);
+                       }
                }
        } while (! waitq_empty(wq));
        del_waitq(wq);
+       DB((dbg, LEVEL_2, "\n"));
 }
 
 /**