Remove dead nodes more efficiently
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5462 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/DataStructure/DataStructure.cpp b/lib/Analysis/DataStructure/DataStructure.cpp
index a0e5770..8a6eab4 100644
--- a/lib/Analysis/DataStructure/DataStructure.cpp
+++ b/lib/Analysis/DataStructure/DataStructure.cpp
@@ -1095,7 +1095,8 @@
for (unsigned i = 0; i != Nodes.size(); ++i)
if (!Alive.count(Nodes[i])) {
DSNode *N = Nodes[i];
- Nodes.erase(Nodes.begin()+i--); // Erase node from alive list.
+ std::swap(Nodes[i--], Nodes.back()); // move node to end of vector
+ Nodes.pop_back(); // Erase node from alive list.
DeadNodes.push_back(N); // Add node to our list of dead nodes
N->dropAllReferences(); // Drop all outgoing edges
}