Add Loop contains utility methods for testing whether a loop

contains another loop, or an instruction. The loop form is
substantially more efficient on large loops than the typical
code it replaces.

llvm-svn: 91654

1 files changed, 17 insertions, 1 deletions

diff --git a/llvm/include/llvm/Analysis/LoopInfo.h b/llvm/include/llvm/Analysis/LoopInfo.h
index 2294e5352cb..d513f2cb4e2 100644
--- a/llvm/include/llvm/Analysis/LoopInfo.h
+++ b/llvm/include/llvm/Analysis/LoopInfo.h
@@ -93,12 +93,28 @@ public:
   BlockT *getHeader() const { return Blocks.front(); }
   LoopT *getParentLoop() const { return ParentLoop; }
 
-  /// contains - Return true if the specified basic block is in this loop
+  /// contains - Return true if the specified loop is contained within in
+  /// this loop.
+  ///
+  bool contains(const LoopT *L) const {
+    if (L == this) return true;
+    if (L == 0)    return false;
+    return contains(L->getParentLoop());
+  }
+    
+  /// contains - Return true if the specified basic block is in this loop.
   ///
   bool contains(const BlockT *BB) const {
     return std::find(block_begin(), block_end(), BB) != block_end();
   }
 
+  /// contains - Return true if the specified instruction is in this loop.
+  ///
+  template<class InstT>
+  bool contains(const InstT *Inst) const {
+    return contains(Inst->getParent());
+  }
+
   /// iterator/begin/end - Return the loops contained entirely within this loop.
   ///
   const std::vector<LoopT *> &getSubLoops() const { return SubLoops; }