+ std::string getEdgeAttributes(RegionNode *srcNode,
+ GraphTraits<RegionInfo*>::ChildIteratorType CI, RegionInfo *RI) {
+
+ RegionNode *destNode = *CI;
+
+ if (srcNode->isSubRegion() || destNode->isSubRegion())
+ return "";
+
+ // In case of a backedge, do not use it to define the layout of the nodes.
+ BasicBlock *srcBB = srcNode->getNodeAs<BasicBlock>();
+ BasicBlock *destBB = destNode->getNodeAs<BasicBlock>();
+
+ Region *R = RI->getRegionFor(destBB);
+
+ while (R && R->getParent())
+ if (R->getParent()->getEntry() == destBB)
+ R = R->getParent();
+ else
+ break;
+
+ if (R->getEntry() == destBB && R->contains(srcBB))
+ return "constraint=false";
+
+ return "";
+ }
+