[FunctionAttrs] Extract a helper function for the core logic used to

[oota-llvm.git] / lib / CodeGen / BranchFolding.h

diff --git a/lib/CodeGen/BranchFolding.h b/lib/CodeGen/BranchFolding.h
index 15dfa7f6bee56436e2825604dfbeb30c5f43462b..46c05dc0600a214026a668ba47bd9b41920c18d0 100644 (file)
--- a/lib/CodeGen/BranchFolding.h
+++ b/lib/CodeGen/BranchFolding.h
@@ -1,4 +1,4 @@
-//===-- BranchFolding.h - Fold machine code branch instructions --*- C++ -*===//
+//===-- BranchFolding.h - Fold machine code branch instructions -*- C++ -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
@@ -7,23 +7,28 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef LLVM_CODEGEN_BRANCHFOLDING_HPP
-#define LLVM_CODEGEN_BRANCHFOLDING_HPP
+#ifndef LLVM_LIB_CODEGEN_BRANCHFOLDING_H
+#define LLVM_LIB_CODEGEN_BRANCHFOLDING_H
 
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/CodeGen/MachineBasicBlock.h"
+#include "llvm/Support/BlockFrequency.h"
 #include <vector>
 
 namespace llvm {
+  class MachineBlockFrequencyInfo;
+  class MachineBranchProbabilityInfo;
   class MachineFunction;
   class MachineModuleInfo;
   class RegScavenger;
   class TargetInstrInfo;
   class TargetRegisterInfo;
-  template<typename T> class SmallVectorImpl;
 
-  class BranchFolder {
+  class LLVM_LIBRARY_VISIBILITY BranchFolder {
   public:
-    explicit BranchFolder(bool defaultEnableTailMerge);
+    explicit BranchFolder(bool defaultEnableTailMerge, bool CommonHoist,
+                          const MachineBlockFrequencyInfo &MBFI,
+                          const MachineBranchProbabilityInfo &MBPI);
 
     bool OptimizeFunction(MachineFunction &MF,
                           const TargetInstrInfo *tii,
@@ -48,6 +53,7 @@ namespace llvm {
     };
     typedef std::vector<MergePotentialsElt>::iterator MPIterator;
     std::vector<MergePotentialsElt> MergePotentials;
+    SmallPtrSet<const MachineBasicBlock*, 2> TriedMerging;
 
     class SameTailElt {
       MPIterator MPIter;
@@ -85,24 +91,46 @@ namespace llvm {
     std::vector<SameTailElt> SameTails;
 
     bool EnableTailMerge;
+    bool EnableHoistCommonCode;
     const TargetInstrInfo *TII;
     const TargetRegisterInfo *TRI;
     MachineModuleInfo *MMI;
     RegScavenger *RS;
 
+    /// \brief This class keeps track of branch frequencies of newly created
+    /// blocks and tail-merged blocks.
+    class MBFIWrapper {
+    public:
+      MBFIWrapper(const MachineBlockFrequencyInfo &I) : MBFI(I) {}
+      BlockFrequency getBlockFreq(const MachineBasicBlock *MBB) const;
+      void setBlockFreq(const MachineBasicBlock *MBB, BlockFrequency F);
+
+    private:
+      const MachineBlockFrequencyInfo &MBFI;
+      DenseMap<const MachineBasicBlock *, BlockFrequency> MergedBBFreq;
+    };
+
+    MBFIWrapper MBBFreqInfo;
+    const MachineBranchProbabilityInfo &MBPI;
+
     bool TailMergeBlocks(MachineFunction &MF);
     bool TryTailMergeBlocks(MachineBasicBlock* SuccBB,
                        MachineBasicBlock* PredBB);
+    void setCommonTailEdgeWeights(MachineBasicBlock &TailMBB);
+    void MaintainLiveIns(MachineBasicBlock *CurMBB,
+                         MachineBasicBlock *NewMBB);
     void ReplaceTailWithBranchTo(MachineBasicBlock::iterator OldInst,
                                  MachineBasicBlock *NewDest);
     MachineBasicBlock *SplitMBBAt(MachineBasicBlock &CurMBB,
-                                  MachineBasicBlock::iterator BBI1);
+                                  MachineBasicBlock::iterator BBI1,
+                                  const BasicBlock *BB);
     unsigned ComputeSameTails(unsigned CurHash, unsigned minCommonTailLength,
                               MachineBasicBlock *SuccBB,
                               MachineBasicBlock *PredBB);
     void RemoveBlocksWithHash(unsigned CurHash, MachineBasicBlock* SuccBB,
                                                 MachineBasicBlock* PredBB);
     bool CreateCommonTailOnlyBlock(MachineBasicBlock *&PredBB,
+                                   MachineBasicBlock *SuccBB,
                                    unsigned maxCommonTailLength,
                                    unsigned &commonTailIndex);
 
@@ -110,6 +138,9 @@ namespace llvm {
     bool OptimizeBlock(MachineBasicBlock *MBB);
     void RemoveDeadBlock(MachineBasicBlock *MBB);
     bool OptimizeImpDefsBlock(MachineBasicBlock *MBB);
+
+    bool HoistCommonCode(MachineFunction &MF);
+    bool HoistCommonCodeInSuccs(MachineBasicBlock *MBB);
   };
 }