Revert all my SSAUpdater patches. The PHI placement algorithm is not correct

(what was I thinking?) and there's also a problem with LCSSA.  I'll try again
later with fixes.

--- Reverse-merging r100263 into '.':
U    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100177 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100148 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100147 into '.':
U    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100131 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100130 into '.':
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100126 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp
--- Reverse-merging r100050 into '.':
D    test/Transforms/GVN/2010-03-31-RedundantPHIs.ll
--- Reverse-merging r100047 into '.':
G    include/llvm/Transforms/Utils/SSAUpdater.h
G    lib/Transforms/Utils/SSAUpdater.cpp

llvm-svn: 100264

1 files changed, 9 insertions, 23 deletions

diff --git a/llvm/include/llvm/Transforms/Utils/SSAUpdater.h b/llvm/include/llvm/Transforms/Utils/SSAUpdater.h
index b29b749e8d9..927e156abfb 100644
--- a/llvm/include/llvm/Transforms/Utils/SSAUpdater.h
+++ b/llvm/include/llvm/Transforms/Utils/SSAUpdater.h
@@ -27,28 +27,22 @@ namespace llvm {
 /// transformation wants to rewrite a set of uses of one value with uses of a
 /// set of values.
 class SSAUpdater {
-public:
-  class BBInfo;
-
-private:
   /// AvailableVals - This keeps track of which value to use on a per-block
-  /// basis.  When we insert PHI nodes, we keep track of them here.
-  //typedef DenseMap<BasicBlock*, Value*> AvailableValsTy;
+  /// basis.  When we insert PHI nodes, we keep track of them here.  We use
+  /// TrackingVH's for the value of the map because we RAUW PHI nodes when we
+  /// eliminate them, and want the TrackingVH's to track this.
+  //typedef DenseMap<BasicBlock*, TrackingVH<Value> > AvailableValsTy;
   void *AV;
 
   /// PrototypeValue is an arbitrary representative value, which we derive names
   /// and a type for PHI nodes.
   Value *PrototypeValue;
 
-  /// BBMap - The GetValueAtEndOfBlock method maintains this mapping from
-  /// basic blocks to BBInfo structures.
-  /// typedef DenseMap<BasicBlock*, BBInfo*> BBMapTy;
-  void *BM;
-
-  /// Allocator - The GetValueAtEndOfBlock method uses this BumpPtrAllocator to
-  /// hold its internal data.  The allocator and its storage is created and
-  /// discarded for each invocation of GetValueAtEndOfBlock.
-  void *BPA;
+  /// IncomingPredInfo - We use this as scratch space when doing our recursive
+  /// walk.  This should only be used in GetValueInBlockInternal, normally it
+  /// should be empty.
+  //std::vector<std::pair<BasicBlock*, TrackingVH<Value> > > IncomingPredInfo;
+  void *IPI;
 
   /// InsertedPHIs - If this is non-null, the SSAUpdater adds all PHI nodes that
   /// it creates to the vector.
@@ -105,14 +99,6 @@ public:
 
 private:
   Value *GetValueAtEndOfBlockInternal(BasicBlock *BB);
-  void FindPHIPlacement(BasicBlock *BB, BBInfo *Info, bool &Changed,
-                        unsigned Counter);
-  void FindAvailableVal(BasicBlock *BB, BBInfo *Info, unsigned Counter);
-  void FindExistingPHI(BasicBlock *BB);
-  bool CheckIfPHIMatches(PHINode *PHI);
-  void RecordMatchingPHI(PHINode *PHI);
-  void ClearPHITags(PHINode *PHI);
-
   void operator=(const SSAUpdater&); // DO NOT IMPLEMENT
   SSAUpdater(const SSAUpdater&);     // DO NOT IMPLEMENT
 };