RegionPrinter: Ignore back edges when layouting the graph
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126564 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/RegionPrinter.cpp b/lib/Analysis/RegionPrinter.cpp
index 0cf0f90..a1730b0 100644
--- a/lib/Analysis/RegionPrinter.cpp
+++ b/lib/Analysis/RegionPrinter.cpp
@@ -70,6 +70,32 @@
G->getTopLevelRegion());
}
+ 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 "";
+ }
+
// Print the cluster of the subregions. This groups the single basic blocks
// and adds a different background color for each group.
static void printRegionCluster(const Region *R, GraphWriter<RegionInfo*> &GW,