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).
// 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
/// 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);
/// 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.,
/// 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(); }
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
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.