From: Brian Norris <banorris@uci.edu>
Date: Wed, 6 Feb 2013 22:42:00 +0000 (-0800)
Subject: cyclegraph: mergeNodes(): return early if we violate RMW
X-Git-Tag: oopsla2013~278
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=commitdiff_plain;h=3e538ef764be5b82ef8a58f1fcdf98708cd8aa73

cyclegraph: mergeNodes(): return early if we violate RMW

To be consistent, and to prevent unecessary merging work, we should
simply return from the mergeNodes() function as soon as we know it has
failed.
---

diff --git a/cyclegraph.cc b/cyclegraph.cc
index b138372..89fc36c 100644
--- a/cyclegraph.cc
+++ b/cyclegraph.cc
@@ -147,8 +147,10 @@ bool CycleGraph::mergeNodes(CycleNode *w_node, CycleNode *p_node,
 
 	/* Transfer the RMW */
 	CycleNode *promise_rmw = p_node->getRMW();
-	if (promise_rmw && promise_rmw != w_node->getRMW() && w_node->setRMW(promise_rmw))
+	if (promise_rmw && promise_rmw != w_node->getRMW() && w_node->setRMW(promise_rmw)) {
 		hasCycles = true;
+		return false;
+	}
 
 	/* Transfer back edges to w_node */
 	while (p_node->getNumBackEdges() > 0) {