include/llvm/CodeGen/MachineBlockFrequencyInfo.h

   1 //====----- MachineBlockFrequencyInfo.h - MachineBlock Frequency Analysis ----====//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Loops should be simplified before this analysis.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
  15 #define LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
  16
  17 #include "llvm/CodeGen/MachineFunctionPass.h"
  18 #include "llvm/Support/BlockFrequency.h"
  19 #include <climits>
  20
  21 namespace llvm {
  22
  23 class MachineBranchProbabilityInfo;
  24 template<class BlockT, class FunctionT, class BranchProbInfoT>
  25 class BlockFrequencyImpl;
  26
  27 /// MachineBlockFrequencyInfo pass uses BlockFrequencyImpl implementation to estimate
  28 /// machine basic block frequencies.
  29 class MachineBlockFrequencyInfo : public MachineFunctionPass {
  30
  31   BlockFrequencyImpl<MachineBasicBlock, MachineFunction, MachineBranchProbabilityInfo> *MBFI;
  32
  33 public:
  34   static char ID;
  35
  36   MachineBlockFrequencyInfo();
  37
  38   ~MachineBlockFrequencyInfo();
  39
  40   void getAnalysisUsage(AnalysisUsage &AU) const;
  41
  42   bool runOnMachineFunction(MachineFunction &F);
  43
  44   /// getblockFreq - Return block frequency. Return 0 if we don't have the
  45   /// information. Please note that initial frequency is equal to 1024. It means
  46   /// that we should not rely on the value itself, but only on the comparison to
  47   /// the other block frequencies. We do this to avoid using of floating points.
  48   ///
  49   BlockFrequency getBlockFreq(MachineBasicBlock *MBB);
  50 };
  51
  52 }
  53
  54 #endif