Add Region::isTopLevelRegion().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116402 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 8 insertions, 3 deletions

diff --git a/include/llvm/Analysis/RegionInfo.h b/include/llvm/Analysis/RegionInfo.h
index 4e7d303..b6ac1b3 100644
--- a/include/llvm/Analysis/RegionInfo.h
+++ b/include/llvm/Analysis/RegionInfo.h
@@ -292,6 +292,11 @@ public:
   /// @return The depth of the region.
   unsigned getDepth() const;
 
+  /// @brief Check if a Region is the TopLevel region.
+  ///
+  /// The toplevel region represents the whole function.
+  bool isTopLevelRegion() const { return exit == NULL; };
+
   /// @brief Return a new (non canonical) region, that is obtained by joining
   ///        this region with its predecessors.
   ///
diff --git a/lib/Analysis/RegionInfo.cpp b/lib/Analysis/RegionInfo.cpp
index 9d84f55..d26135c 100644
--- a/lib/Analysis/RegionInfo.cpp
+++ b/lib/Analysis/RegionInfo.cpp
@@ -140,8 +140,7 @@ bool Region::isSimple() const {
 
   BasicBlock *entry = getEntry(), *exit = getExit();
 
-  // TopLevelRegion
-  if (!exit)
+  if (isTopLevelRegion())
     return false;
 
   for (pred_iterator PI = pred_begin(entry), PE = pred_end(entry); PI != PE;
@@ -810,9 +809,10 @@ RegionInfo::getCommonRegion(SmallVectorImpl<BasicBlock*> &BBs) const {
 void RegionInfo::splitBlock(BasicBlock* NewBB, BasicBlock *OldBB)
 {
   Region *R = getRegionFor(OldBB);
+
   setRegionFor(NewBB, R);
 
-  while (R->getEntry() == OldBB && R->getParent()) {
+  while (R->getEntry() == OldBB && !R->isTopLevelRegion()) {
     R->replaceEntry(NewBB);
     R = R->getParent();
   }