1 files changed, 9 insertions, 3 deletions

diff --git a/llvm/lib/CodeGen/BranchFolding.h b/llvm/lib/CodeGen/BranchFolding.h
index 36a5a2e2c97..bce8d62b14c 100644
--- a/llvm/lib/CodeGen/BranchFolding.h
+++ b/llvm/lib/CodeGen/BranchFolding.h
@@ -29,9 +29,13 @@ namespace llvm {
   public:
     class MBFIWrapper;
 
-    explicit BranchFolder(bool defaultEnableTailMerge, bool CommonHoist,
+    explicit BranchFolder(bool defaultEnableTailMerge,
+                          bool CommonHoist,
                           MBFIWrapper &MBFI,
-                          const MachineBranchProbabilityInfo &MBPI);
+                          const MachineBranchProbabilityInfo &MBPI,
+                          // Min tail length to merge. Defaults to commandline
+                          // flag. Ignored for optsize.
+                          unsigned MinCommonTailLength = 0);
 
     bool OptimizeFunction(MachineFunction &MF, const TargetInstrInfo *tii,
                           const TargetRegisterInfo *tri, MachineModuleInfo *mmi,
@@ -99,6 +103,7 @@ namespace llvm {
     bool EnableTailMerge;
     bool EnableHoistCommonCode;
     bool UpdateLiveIns;
+    unsigned MinCommonTailLength;
     const TargetInstrInfo *TII;
     const TargetRegisterInfo *TRI;
     MachineModuleInfo *MMI;
@@ -129,7 +134,8 @@ namespace llvm {
 
     bool TailMergeBlocks(MachineFunction &MF);
     bool TryTailMergeBlocks(MachineBasicBlock* SuccBB,
-                       MachineBasicBlock* PredBB);
+                       MachineBasicBlock* PredBB,
+                       unsigned MinCommonTailLength);
     void setCommonTailEdgeWeights(MachineBasicBlock &TailMBB);
     void computeLiveIns(MachineBasicBlock &MBB);
     void ReplaceTailWithBranchTo(MachineBasicBlock::iterator OldInst,