[LCG] Switch the parent SCC tracking from a SmallSetVector to

a SmallPtrSet. Currently, there is no need for stable iteration in this
dimension, and I now thing there won't need to be going forward.

If this is ever re-introduced in any form, it needs to not be
a SetVector based solution because removal cannot be linear. There will
be many SCCs with large numbers of parents. When encountering these, the
incremental SCC update for intra-SCC edge removal was quadratic due to
linear removal (kind of).

I'm really hoping we can avoid having an ordering property here at all
though...

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@207091 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 2 deletions

diff --git a/include/llvm/Analysis/LazyCallGraph.h b/include/llvm/Analysis/LazyCallGraph.h
index ea65cbac1d..b53e77b4f7 100644
--- a/include/llvm/Analysis/LazyCallGraph.h
+++ b/include/llvm/Analysis/LazyCallGraph.h
@@ -215,7 +215,7 @@ public:
     friend class LazyCallGraph;
     friend class LazyCallGraph::Node;
 
-    SmallSetVector<SCC *, 1> ParentSCCs;
+    SmallPtrSet<SCC *, 1> ParentSCCs;
     SmallVector<Node *, 1> Nodes;
 
     SCC() {}
@@ -228,7 +228,7 @@ public:
 
   public:
     typedef SmallVectorImpl<Node *>::const_iterator iterator;
-    typedef pointee_iterator<SmallSetVector<SCC *, 1>::const_iterator> parent_iterator;
+    typedef pointee_iterator<SmallPtrSet<SCC *, 1>::const_iterator> parent_iterator;
 
     iterator begin() const { return Nodes.begin(); }
     iterator end() const { return Nodes.end(); }