Revert "ScheduleDAGInstrs: Rework schedule graph builder."
[oota-llvm.git] / include / llvm / CodeGen / MachineBranchProbabilityInfo.h
index 98dd03b45cf7837c837004bea216ef225ae78dd7..608e8d257874db1fb6cecb7fbe09750aa041b00e 100644 (file)
@@ -1,4 +1,4 @@
-//==- MachineBranchProbabilityInfo.h - Machine Branch Probability Analysis -==//
+//=- MachineBranchProbabilityInfo.h - Branch Probability Analysis -*- C++ -*-=//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -18,6 +18,7 @@
 #include "llvm/Pass.h"
 #include "llvm/Support/BranchProbability.h"
 #include <climits>
+#include <numeric>
 
 namespace llvm {
 
@@ -40,7 +41,7 @@ public:
     initializeMachineBranchProbabilityInfoPass(Registry);
   }
 
-  void getAnalysisUsage(AnalysisUsage &AU) const {
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesAll();
   }
 
@@ -54,32 +55,30 @@ public:
   uint32_t getEdgeWeight(const MachineBasicBlock *Src,
                          MachineBasicBlock::const_succ_iterator Dst) const;
 
-  // Get sum of the block successors' weights, potentially scaling them to fit
-  // within 32-bits. If scaling is required, sets Scale based on the necessary
-  // adjustment. Any edge weights used with the sum should be divided by Scale.
-  uint32_t getSumForBlock(const MachineBasicBlock *MBB, uint32_t &Scale) const;
+  // Return edge probability.
+  BranchProbability getEdgeProbability(const MachineBasicBlock *Src,
+                                       const MachineBasicBlock *Dst) const;
+
+  // Same as above, but using a const_succ_iterator from Src. This is faster
+  // when the iterator is already available.
+  BranchProbability
+  getEdgeProbability(const MachineBasicBlock *Src,
+                     MachineBasicBlock::const_succ_iterator Dst) const;
 
   // A 'Hot' edge is an edge which probability is >= 80%.
-  bool isEdgeHot(MachineBasicBlock *Src, MachineBasicBlock *Dst) const;
+  bool isEdgeHot(const MachineBasicBlock *Src,
+                 const MachineBasicBlock *Dst) const;
 
   // Return a hot successor for the block BB or null if there isn't one.
   // NB: This routine's complexity is linear on the number of successors.
   MachineBasicBlock *getHotSucc(MachineBasicBlock *MBB) const;
 
-  // Return a probability as a fraction between 0 (0% probability) and
-  // 1 (100% probability), however the value is never equal to 0, and can be 1
-  // only iff SRC block has only one successor.
-  // NB: This routine's complexity is linear on the number of successors of
-  // Src. Querying sequentially for each successor's probability is a quadratic
-  // query pattern.
-  BranchProbability getEdgeProbability(MachineBasicBlock *Src,
-                                       MachineBasicBlock *Dst) const;
-
   // Print value between 0 (0% probability) and 1 (100% probability),
   // however the value is never equal to 0, and can be 1 only iff SRC block
   // has only one successor.
-  raw_ostream &printEdgeProbability(raw_ostream &OS, MachineBasicBlock *Src,
-                                    MachineBasicBlock *Dst) const;
+  raw_ostream &printEdgeProbability(raw_ostream &OS,
+                                    const MachineBasicBlock *Src,
+                                    const MachineBasicBlock *Dst) const;
 };
 
 }