Update llvm to r84119.

1 files changed, 108 insertions, 0 deletions

diff --git a/include/llvm/Transforms/Utils/SSAUpdater.h b/include/llvm/Transforms/Utils/SSAUpdater.h
new file mode 100644
index 0000000..11b90d4
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+++ b/include/llvm/Transforms/Utils/SSAUpdater.h
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+//===-- SSAUpdater.h - Unstructured SSA Update Tool -------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the SSAUpdater class.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_UTILS_SSAUPDATER_H
+#define LLVM_TRANSFORMS_UTILS_SSAUPDATER_H
+
+namespace llvm {
+  class Value;
+  class BasicBlock;
+  class Use;
+  class PHINode;
+  template<typename T>
+  class SmallVectorImpl;
+  
+/// SSAUpdater - This class updates SSA form for a set of values defined in
+/// multiple blocks.  This is used when code duplication or another unstructured
+/// transformation wants to rewrite a set of uses of one value with uses of a
+/// set of values.
+class SSAUpdater {
+  /// 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.  We use
+  /// WeakVH's for the value of the map because we RAUW PHI nodes when we
+  /// eliminate them, and want the WeakVH 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;
+  
+  /// 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.
+  SmallVectorImpl<PHINode*> *InsertedPHIs;
+public:
+  /// SSAUpdater constructor.  If InsertedPHIs is specified, it will be filled
+  /// in with all PHI Nodes created by rewriting.
+  SSAUpdater(SmallVectorImpl<PHINode*> *InsertedPHIs = 0);
+  ~SSAUpdater();
+  
+  /// Initialize - Reset this object to get ready for a new set of SSA
+  /// updates.  ProtoValue is the value used to name PHI nodes.
+  void Initialize(Value *ProtoValue);
+  
+  /// AddAvailableValue - Indicate that a rewritten value is available at the
+  /// end of the specified block with the specified value.
+  void AddAvailableValue(BasicBlock *BB, Value *V);
+
+  /// HasValueForBlock - Return true if the SSAUpdater already has a value for
+  /// the specified block.
+  bool HasValueForBlock(BasicBlock *BB) const;
+  
+  /// GetValueAtEndOfBlock - Construct SSA form, materializing a value that is
+  /// live at the end of the specified block.
+  Value *GetValueAtEndOfBlock(BasicBlock *BB);
+  
+  /// GetValueInMiddleOfBlock - Construct SSA form, materializing a value that
+  /// is live in the middle of the specified block.
+  ///
+  /// GetValueInMiddleOfBlock is the same as GetValueAtEndOfBlock except in one
+  /// important case: if there is a definition of the rewritten value after the
+  /// 'use' in BB.  Consider code like this:
+  ///
+  ///      X1 = ...
+  ///   SomeBB:
+  ///      use(X)
+  ///      X2 = ...
+  ///      br Cond, SomeBB, OutBB
+  ///
+  /// In this case, there are two values (X1 and X2) added to the AvailableVals
+  /// set by the client of the rewriter, and those values are both live out of
+  /// their respective blocks.  However, the use of X happens in the *middle* of
+  /// a block.  Because of this, we need to insert a new PHI node in SomeBB to
+  /// merge the appropriate values, and this value isn't live out of the block.
+  ///
+  Value *GetValueInMiddleOfBlock(BasicBlock *BB);
+  
+  /// RewriteUse - Rewrite a use of the symbolic value.  This handles PHI nodes,
+  /// which use their value in the corresponding predecessor.  Note that this
+  /// will not work if the use is supposed to be rewritten to a value defined in
+  /// the same block as the use, but above it.  Any 'AddAvailableValue's added
+  /// for the use's block will be considered to be below it.
+  void RewriteUse(Use &U);
+  
+private:
+  Value *GetValueAtEndOfBlockInternal(BasicBlock *BB);
+  void operator=(const SSAUpdater&); // DO NOT IMPLEMENT
+  SSAUpdater(const SSAUpdater&);     // DO NOT IMPLEMENT
+};
+
+} // End llvm namespace
+
+#endif