Revert r254348: "Replace all weight-based interfaces in MBB with probability-based...

[oota-llvm.git] / include / llvm / CodeGen / MachineBasicBlock.h

diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index ac87f4f901f5d594d3f67d577b97b95c4a6d283e..a2b1a850ec76dbb255bf746d047175b769d0ca46 100644 (file)
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -91,6 +91,13 @@ private:
   std::vector<MachineBasicBlock *> Predecessors;
   std::vector<MachineBasicBlock *> Successors;
 
+  /// Keep track of the weights to the successors. This vector has the same
+  /// order as Successors, or it is empty if we don't use it (disable
+  /// optimization).
+  std::vector<uint32_t> Weights;
+  typedef std::vector<uint32_t>::iterator weight_iterator;
+  typedef std::vector<uint32_t>::const_iterator const_weight_iterator;
+
   /// Keep track of the probabilities to the successors. This vector has the
   /// same order as Successors, or it is empty if we don't use it (disable
   /// optimization).
@@ -433,16 +440,26 @@ public:
 
   // Machine-CFG mutators
 
+  /// Add Succ as a successor of this MachineBasicBlock.  The Predecessors list
+  /// of Succ is automatically updated. WEIGHT parameter is stored in Weights
+  /// list and it may be used by MachineBranchProbabilityInfo analysis to
+  /// calculate branch probability.
+  ///
+  /// Note that duplicate Machine CFG edges are not allowed.
+  void addSuccessor(MachineBasicBlock *Succ, uint32_t Weight = 0);
+
+  /// Add Succ as a successor of this MachineBasicBlock.  The Predecessors list
+  /// of Succ is automatically updated. The weight is not provided because BPI
+  /// is not available (e.g. -O0 is used), in which case edge weights won't be
+  /// used. Using this interface can save some space.
+  void addSuccessorWithoutWeight(MachineBasicBlock *Succ);
+
   /// Add Succ as a successor of this MachineBasicBlock.  The Predecessors list
   /// of Succ is automatically updated. PROB parameter is stored in
-  /// Probabilities list. The default probability is set as unknown. Mixing
-  /// known and unknown probabilities in successor list is not allowed. When all
-  /// successors have unknown probabilities, 1 / N is returned as the
-  /// probability for each successor, where N is the number of successors.
+  /// Probabilities list.
   ///
   /// Note that duplicate Machine CFG edges are not allowed.
-  void addSuccessor(MachineBasicBlock *Succ,
-                    BranchProbability Prob = BranchProbability::getUnknown());
+  void addSuccessor(MachineBasicBlock *Succ, BranchProbability Prob);
 
   /// Add Succ as a successor of this MachineBasicBlock.  The Predecessors list
   /// of Succ is automatically updated. The probability is not provided because
@@ -450,6 +467,9 @@ public:
   /// won't be used. Using this interface can save some space.
   void addSuccessorWithoutProb(MachineBasicBlock *Succ);
 
+  /// Set successor weight of a given iterator.
+  void setSuccWeight(succ_iterator I, uint32_t Weight);
+
   /// Set successor probability of a given iterator.
   void setSuccProbability(succ_iterator I, BranchProbability Prob);
 
@@ -468,7 +488,7 @@ public:
   /// Return the iterator to the element after the one removed.
   succ_iterator removeSuccessor(succ_iterator I);
 
-  /// Replace successor OLD with NEW and update probability info.
+  /// Replace successor OLD with NEW and update weight info.
   void replaceSuccessor(MachineBasicBlock *Old, MachineBasicBlock *New);
 
   /// Transfers all the successors from MBB to this machine basic block (i.e.,
@@ -480,6 +500,9 @@ public:
   /// operands in the successor blocks which refer to FromMBB to refer to this.
   void transferSuccessorsAndUpdatePHIs(MachineBasicBlock *FromMBB);
 
+  /// Return true if any of the successors have weights attached to them.
+  bool hasSuccessorWeights() const { return !Weights.empty(); }
+
   /// Return true if any of the successors have probabilities attached to them.
   bool hasSuccessorProbabilities() const { return !Probs.empty(); }
 
@@ -736,6 +759,10 @@ public:
 
 
 private:
+  /// Return weight iterator corresponding to the I successor iterator.
+  weight_iterator getWeightIterator(succ_iterator I);
+  const_weight_iterator getWeightIterator(const_succ_iterator I) const;
+
   /// Return probability iterator corresponding to the I successor iterator.
   probability_iterator getProbabilityIterator(succ_iterator I);
   const_probability_iterator
@@ -744,6 +771,11 @@ private:
   friend class MachineBranchProbabilityInfo;
   friend class MIPrinter;
 
+  /// Return weight of the edge from this block to MBB. This method should NOT
+  /// be called directly, but by using getEdgeWeight method from
+  /// MachineBranchProbabilityInfo class.
+  uint32_t getSuccWeight(const_succ_iterator Succ) const;
+
   /// Return probability of the edge from this block to MBB. This method should
   /// NOT be called directly, but by using getEdgeProbability method from
   /// MachineBranchProbabilityInfo class.