Add function DominatorTree::getDescendants().

  As its name suggests, this function will return all basic blocks
dominated by a given block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191014 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 20 insertions, 0 deletions

diff --git a/include/llvm/Analysis/Dominators.h b/include/llvm/Analysis/Dominators.h
index 81c04bb6b0..3aa0beb6bb 100644
--- a/include/llvm/Analysis/Dominators.h
+++ b/include/llvm/Analysis/Dominators.h
@@ -346,6 +346,20 @@ public:
   DomTreeNodeBase<NodeT> *getRootNode() { return RootNode; }
   const DomTreeNodeBase<NodeT> *getRootNode() const { return RootNode; }
 
+  /// Get all nodes dominated by R, including R itself. Return true on success.
+  void getDescendants(NodeT *R, SmallVectorImpl<NodeT *> &Result) const {
+    const DomTreeNodeBase<NodeT> *RN = getNode(R);
+    SmallVector<const DomTreeNodeBase<NodeT> *, 8> WL;
+    WL.push_back(RN);
+    Result.clear();
+
+    while (!WL.empty()) {
+      const DomTreeNodeBase<NodeT> *N = WL.pop_back_val();
+      Result.push_back(N->getBlock());
+      WL.append(N->begin(), N->end());
+    }
+  }
+
   /// properlyDominates - Returns true iff A dominates B and A != B.
   /// Note that this is not a constant time operation!
   ///
@@ -755,6 +769,12 @@ public:
     return DT->getRootNode();
   }
 
+  /// Get all nodes dominated by R, including R itself. Return true on success.
+  void getDescendants(BasicBlock *R,
+                     SmallVectorImpl<BasicBlock *> &Result) const {
+    DT->getDescendants(R, Result);
+  }
+
   /// compare - Return false if the other dominator tree matches this
   /// dominator tree. Otherwise return true.
   inline bool compare(DominatorTree &Other) const {