[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...

llvm-svn: 207091

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Analysis/LazyCallGraph.cpp b/llvm/lib/Analysis/LazyCallGraph.cpp
index 832d2b9e7e6..c4d597e2f4f 100644
--- a/llvm/lib/Analysis/LazyCallGraph.cpp
+++ b/llvm/lib/Analysis/LazyCallGraph.cpp
@@ -157,7 +157,7 @@ void LazyCallGraph::SCC::removeEdge(LazyCallGraph &G, Function &Caller,
   // the caller no longer a parent of the callee. Walk the other call edges
   // in the caller to tell.
   if (!HasOtherCallToCalleeC) {
-    bool Removed = CalleeC.ParentSCCs.remove(this);
+    bool Removed = CalleeC.ParentSCCs.erase(this);
     (void)Removed;
     assert(Removed &&
            "Did not find the caller SCC in the callee SCC's parent list!");
@@ -239,7 +239,7 @@ LazyCallGraph::SCC::removeInternalEdge(LazyCallGraph &G, Node &Caller,
         // However, we do need to remove this SCC from its SCC's parent set.
         SCC &ChildSCC = *G.SCCMap.lookup(&ChildN);
         if (&ChildSCC != this) {
-          ChildSCC.ParentSCCs.remove(this);
+          ChildSCC.ParentSCCs.erase(this);
           continue;
         }