Normalize MBB's successors' probabilities in several locations.

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

diff --git a/include/llvm/CodeGen/MachineBasicBlock.h b/include/llvm/CodeGen/MachineBasicBlock.h
index 16a349fdeb1e185ebfa656b120ced6a6db27546b..3d58c499823e86725e9263a79d29830acd4eae26 100644 (file)
--- a/include/llvm/CodeGen/MachineBasicBlock.h
+++ b/include/llvm/CodeGen/MachineBasicBlock.h
@@ -454,19 +454,32 @@ public:
   void setSuccProbability(succ_iterator I, BranchProbability Prob);
 
   /// Normalize probabilities of all successors so that the sum of them becomes
-  /// one.
+  /// one. This is usually done when the current update on this MBB is done, and
+  /// the sum of its successors' probabilities is not guaranteed to be one. The
+  /// user is responsible for the correct use of this function.
+  /// MBB::removeSuccessor() has an option to do this automatically.
   void normalizeSuccProbs() {
     BranchProbability::normalizeProbabilities(Probs.begin(), Probs.end());
   }
 
+  /// Validate successors' probabilities and check if the sum of them is
+  /// approximate one. This only works in DEBUG mode.
+  void validateSuccProbs() const;
+
   /// Remove successor from the successors list of this MachineBasicBlock. The
   /// Predecessors list of Succ is automatically updated.
-  void removeSuccessor(MachineBasicBlock *Succ);
+  /// If NormalizeSuccProbs is true, then normalize successors' probabilities
+  /// after the successor is removed.
+  void removeSuccessor(MachineBasicBlock *Succ,
+                       bool NormalizeSuccProbs = false);
 
   /// Remove specified successor from the successors list of this
   /// MachineBasicBlock. The Predecessors list of Succ is automatically updated.
+  /// If NormalizeSuccProbs is true, then normalize successors' probabilities
+  /// after the successor is removed.
   /// Return the iterator to the element after the one removed.
-  succ_iterator removeSuccessor(succ_iterator I);
+  succ_iterator removeSuccessor(succ_iterator I,
+                                bool NormalizeSuccProbs = false);
 
   /// Replace successor OLD with NEW and update probability info.
   void replaceSuccessor(MachineBasicBlock *Old, MachineBasicBlock *New);