Add a utility function to LoopInfo to return the exit block

when the loop has exactly one exit, and make use of it in
LoopIndexSplit.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64388 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/include/llvm/Analysis/LoopInfo.h b/include/llvm/Analysis/LoopInfo.h
index 0fa4abe056..b2268a2d74 100644
--- a/include/llvm/Analysis/LoopInfo.h
+++ b/include/llvm/Analysis/LoopInfo.h
@@ -184,6 +184,16 @@ public:
         }
   }
 
+  /// getExitingBlock - If getExitingBlocks would return exactly one block,
+  /// return that block. Otherwise return null.
+  BlockT *getExitingBlock() const {
+    SmallVector<BlockT*, 8> ExitingBlocks;
+    getExitingBlocks(ExitingBlocks);
+    if (ExitingBlocks.size() == 1)
+      return ExitingBlocks[0];
+    return 0;
+  }
+
   /// getExitBlocks - Return all of the successor blocks of this loop.  These
   /// are the blocks _outside of the current loop_ which are branched to.
   ///