contrib/llvm/include/llvm/Analysis/BlockFrequencyInfo.h

   1 //========-------- BlockFrequencyInfo.h - Block 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_ANALYSIS_BLOCKFREQUENCYINFO_H
  15 #define LLVM_ANALYSIS_BLOCKFREQUENCYINFO_H
  16
  17 #include "llvm/Pass.h"
  18 #include "llvm/Support/BlockFrequency.h"
  19 #include <climits>
  20
  21 namespace llvm {
  22
  23 class BranchProbabilityInfo;
  24 template<class BlockT, class FunctionT, class BranchProbInfoT>
  25 class BlockFrequencyImpl;
  26
  27 /// BlockFrequencyInfo pass uses BlockFrequencyImpl implementation to estimate
  28 /// IR basic block frequencies.
  29 class BlockFrequencyInfo : public FunctionPass {
  30
  31   BlockFrequencyImpl<BasicBlock, Function, BranchProbabilityInfo> *BFI;
  32
  33 public:
  34   static char ID;
  35
  36   BlockFrequencyInfo();
  37
  38   ~BlockFrequencyInfo();
  39
  40   void getAnalysisUsage(AnalysisUsage &AU) const;
  41
  42   bool runOnFunction(Function &F);
  43   void print(raw_ostream &O, const Module *M) const;
  44
  45   /// getblockFreq - Return block frequency. Return 0 if we don't have the
  46   /// information. Please note that initial frequency is equal to 1024. It means
  47   /// that we should not rely on the value itself, but only on the comparison to
  48   /// the other block frequencies. We do this to avoid using of floating points.
  49   ///
  50   BlockFrequency getBlockFreq(const BasicBlock *BB) const;
  51 };
  52
  53 }
  54
  55 #endif