contrib/llvm/include/llvm/Analysis/BlockFrequency.h

   1 //========-------- BlockFrequency.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_BLOCKFREQUENCY_H
  15 #define LLVM_ANALYSIS_BLOCKFREQUENCY_H
  16
  17 #include "llvm/Pass.h"
  18 #include <climits>
  19
  20 namespace llvm {
  21
  22 class BranchProbabilityInfo;
  23 template<class BlockT, class FunctionT, class BranchProbInfoT>
  24 class BlockFrequencyImpl;
  25
  26 /// BlockFrequency pass uses BlockFrequencyImpl implementation to estimate
  27 /// IR basic block frequencies.
  28 class BlockFrequency : public FunctionPass {
  29
  30   BlockFrequencyImpl<BasicBlock, Function, BranchProbabilityInfo> *BFI;
  31
  32 public:
  33   static char ID;
  34
  35   BlockFrequency();
  36
  37   ~BlockFrequency();
  38
  39   void getAnalysisUsage(AnalysisUsage &AU) const;
  40
  41   bool runOnFunction(Function &F);
  42
  43   /// getblockFreq - Return block frequency. Never return 0, value must be
  44   /// positive. Please note that initial frequency is equal to 1024. It means
  45   /// that we should not rely on the value itself, but only on the comparison to
  46   /// the other block frequencies. We do this to avoid using of the floating
  47   /// points.
  48   uint32_t getBlockFreq(BasicBlock *BB);
  49 };
  50
  51 }
  52
  53 #endif