X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FAnalysis%2FLoopIterator.h;h=e3dd96354c65a414969af84d0d735fd47ef9741d;hb=4f7e2c38e864d7eaeb407ac501478e9579624d1b;hp=2797e67b0967f3fa9de2310faec80fdae25f6d40;hpb=5207936a24ab9e0bfaa10e798625df65143e3716;p=oota-llvm.git

diff --git a/include/llvm/Analysis/LoopIterator.h b/include/llvm/Analysis/LoopIterator.h
index 2797e67b096..e3dd96354c6 100644
--- a/include/llvm/Analysis/LoopIterator.h
+++ b/include/llvm/Analysis/LoopIterator.h
@@ -21,10 +21,9 @@
 // reachable from the loop header.
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_ANALYSIS_LOOP_ITERATOR_H
-#define LLVM_ANALYSIS_LOOP_ITERATOR_H
+#ifndef LLVM_ANALYSIS_LOOPITERATOR_H
+#define LLVM_ANALYSIS_LOOPITERATOR_H
 
-#include "llvm/ADT/DepthFirstIterator.h"
 #include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/Analysis/LoopInfo.h"
 
@@ -61,6 +60,9 @@ public:
 
   Loop *getLoop() const { return L; }
 
+  /// Traverse the loop blocks and store the DFS result.
+  void perform(LoopInfo *LI);
+
   /// Return true if postorder numbers are assigned to all loop blocks.
   bool isComplete() const { return PostBlocks.size() == L->getNumBlocks(); }
 
@@ -106,27 +108,21 @@ public:
   }
 };
 
-/// Define a graph of blocks within a loop. Allows LoopBlocksTraversal to
-/// use the generic po_iterator with specialized GraphTraits.
-struct LoopBlocksGraph {
-  Loop *L;
-
-  LoopBlocksGraph(Loop *Container) : L(Container) {}
-};
-
-template<> struct GraphTraits<LoopBlocksGraph> :
-    public GraphTraits<BasicBlock*> {
-
-  static BasicBlock *getEntryNode(LoopBlocksGraph G) {
-    return G.L->getHeader();
-  }
+/// Specialize po_iterator_storage to record postorder numbers.
+template<> class po_iterator_storage<LoopBlocksTraversal, true> {
+  LoopBlocksTraversal &LBT;
+public:
+  po_iterator_storage(LoopBlocksTraversal &lbs) : LBT(lbs) {}
+  // These functions are defined below.
+  bool insertEdge(BasicBlock *From, BasicBlock *To);
+  void finishPostorder(BasicBlock *BB);
 };
 
 /// Traverse the blocks in a loop using a depth-first search.
 class LoopBlocksTraversal {
 public:
   /// Graph traversal iterator.
-  typedef po_iterator<LoopBlocksGraph, LoopBlocksTraversal, true> POTIterator;
+  typedef po_iterator<BasicBlock*, LoopBlocksTraversal, true> POTIterator;
 
 private:
   LoopBlocksDFS &DFS;
@@ -141,10 +137,12 @@ public:
   /// finishPostorder to record the DFS result.
   POTIterator begin() {
     assert(DFS.PostBlocks.empty() && "Need clear DFS result before traversing");
-    return po_ext_begin(LoopBlocksGraph(DFS.L), *this);
+    assert(DFS.L->getNumBlocks() && "po_iterator cannot handle an empty graph");
+    return po_ext_begin(DFS.L->getHeader(), *this);
   }
   POTIterator end() {
-    return po_ext_end(LoopBlocksGraph(DFS.L), *this);
+    // po_ext_end interface requires a basic block, but ignores its value.
+    return po_ext_end(DFS.L->getHeader(), *this);
   }
 
   /// Called by po_iterator upon reaching a block via a CFG edge. If this block
@@ -166,31 +164,17 @@ public:
     DFS.PostBlocks.push_back(BB);
     DFS.PostNumbers[BB] = DFS.PostBlocks.size();
   }
-
-  //===----------------------------------------------------------------------
-  // Implement part of the std::set interface for the purpose of driving the
-  // generic po_iterator.
-
-  /// Return true if the block is outside the loop or has already been visited.
-  /// Sorry if this is counterintuitive.
-  bool count(BasicBlock *BB) const {
-    return !DFS.L->contains(LI->getLoopFor(BB)) || DFS.PostNumbers.count(BB);
-  }
-
-  /// If this block is contained in the loop and has not been visited, return
-  /// true and assign a preorder number. This is a proxy for visitPreorder
-  /// called by POIterator.
-  bool insert(BasicBlock *BB) {
-    return visitPreorder(BB);
-  }
 };
 
-/// Specialize DFSetTraits to record postorder numbers.
-template<> struct DFSetTraits<LoopBlocksTraversal> {
-  static void finishPostorder(BasicBlock *BB, LoopBlocksTraversal& LBT) {
-    LBT.finishPostorder(BB);
-  }
-};
+inline bool po_iterator_storage<LoopBlocksTraversal, true>::
+insertEdge(BasicBlock *From, BasicBlock *To) {
+  return LBT.visitPreorder(To);
+}
+
+inline void po_iterator_storage<LoopBlocksTraversal, true>::
+finishPostorder(BasicBlock *BB) {
+  LBT.finishPostorder(BB);
+}
 
 } // End namespace llvm