Big changes. Interval*.h is now more or less finalized. IntervalPartition

is recoded to use IntervalIterators.  IntervalIterators can now maintain
their own memory or let an external entity do it.

Loop depth is a new user of IntervalPartition for calculating the loop
nesting depth of a basic block

TODO: add IntervalPartition capability to split intervals between the looping
portion and the "tail" portion.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/Interval.h

@@ -39,6 +39,9 @@ public:
     Nodes.push_back(Header);
   }
 
+  inline Interval(const Interval &I) // copy ctor
+    : HeaderNode(I.HeaderNode), Nodes(I.Nodes), Successors(I.Successors) {}
+
   inline BasicBlock *getHeaderNode() const { return HeaderNode; }
 
   // Nodes - The basic blocks in this interval.
@@ -74,6 +77,14 @@ public:
     //return find(Successors.begin(), Successors.end(), BB) != Successors.end();
   }
 
+  // Equality operator.  It is only valid to compare two intervals from the same
+  // partition, because of this, all we have to check is the header node for 
+  // equality.
+  //
+  inline bool operator==(const Interval &I) const {
+    return HeaderNode == I.HeaderNode;
+  }
+
   // isLoop - Find out if there is a back edge in this interval...
   bool isLoop() const;
 };