Add new method for computing node mappings. This is used by the pool allocator
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@9880 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/DataStructure.cpp b/lib/Analysis/DataStructure/DataStructure.cpp
index c20299e..2883899 100644
--- a/lib/Analysis/DataStructure/DataStructure.cpp
+++ b/lib/Analysis/DataStructure/DataStructure.cpp
@@ -1638,3 +1638,34 @@
OldRetNodes.clear();
removeTriviallyDeadNodes();
}
+
+/// computeNodeMapping - Given roots in two different DSGraphs, traverse the
+/// nodes reachable from the two graphs, computing the mapping of nodes from
+/// the first to the second graph.
+///
+void DSGraph::computeNodeMapping(const DSNodeHandle &NH1,
+ const DSNodeHandle &NH2, NodeMapTy &NodeMap) {
+ DSNode *N1 = NH1.getNode(), *N2 = NH2.getNode();
+ if (N1 == 0 || N2 == 0) return;
+
+ DSNodeHandle &Entry = NodeMap[N1];
+ if (Entry.getNode()) {
+ // Termination of recursion!
+ assert(Entry.getNode() == N2 &&
+ Entry.getOffset() == (NH1.getOffset()+NH2.getOffset()) &&
+ "Inconsistent mapping detected!");
+ return;
+ }
+
+ Entry.setNode(N2);
+ Entry.setOffset(NH1.getOffset()+NH2.getOffset());
+
+ // Loop over all of the fields that N1 and N2 have in common, recursively
+ // mapping the edges together now.
+ int N2Idx = NH2.getOffset()-NH1.getOffset();
+ unsigned N2Size = N2->getSize();
+ for (unsigned i = 0, e = N1->getSize(); i < e; i += DS::PointerSize)
+ if (unsigned(N2Idx)+i < N2Size)
+ computeNodeMapping(N1->getLink(i), N2->getLink(N2Idx+i), NodeMap);
+}
+