X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FBranchFolding.h;h=3653a2ccd62375462bf2d1e911ae74c8c16ef9b4;hb=08f77a9f422e96110d8400e4caaf6a51be49a1f3;hp=648ec92b1eb60fc10f3378a96e4d0df01f08bf7f;hpb=72b2990a7495b9df89e151eb711c1e7abdd5f2e5;p=oota-llvm.git

diff --git a/lib/CodeGen/BranchFolding.h b/lib/CodeGen/BranchFolding.h
index 648ec92b1eb..3653a2ccd62 100644
--- 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 {
   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;
@@ -85,39 +91,56 @@ 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);
-    unsigned CreateCommonTailOnlyBlock(MachineBasicBlock *&PredBB,
-                                       unsigned maxCommonTailLength);
+    bool CreateCommonTailOnlyBlock(MachineBasicBlock *&PredBB,
+                                   MachineBasicBlock *SuccBB,
+                                   unsigned maxCommonTailLength,
+                                   unsigned &commonTailIndex);
 
-    bool TailDuplicate(MachineBasicBlock *TailBB,
-                       bool PrevFallsThrough,
-                       MachineFunction &MF);
-    
     bool OptimizeBranches(MachineFunction &MF);
     bool OptimizeBlock(MachineBasicBlock *MBB);
     void RemoveDeadBlock(MachineBasicBlock *MBB);
     bool OptimizeImpDefsBlock(MachineBasicBlock *MBB);
-    
-    bool CanFallThrough(MachineBasicBlock *CurBB);
-    bool CanFallThrough(MachineBasicBlock *CurBB, bool BranchUnAnalyzable,
-                        MachineBasicBlock *TBB, MachineBasicBlock *FBB,
-                        const SmallVectorImpl<MachineOperand> &Cond);
+
+    bool HoistCommonCode(MachineFunction &MF);
+    bool HoistCommonCodeInSuccs(MachineBasicBlock *MBB);
   };
 }