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      1 //===--------------------- SchedulerStatistics.h ----------------*- C++ -*-===//
      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 /// \file
     10 ///
     11 /// This file defines class SchedulerStatistics. Class SchedulerStatistics is a
     12 /// View that listens to instruction issue events in order to print general
     13 /// statistics related to the hardware schedulers.
     14 ///
     15 /// Example:
     16 /// ========
     17 ///
     18 /// Schedulers - number of cycles where we saw N instructions issued:
     19 /// [# issued], [# cycles]
     20 ///  0,          7  (5.4%)
     21 ///  1,          4  (3.1%)
     22 ///  2,          8  (6.2%)
     23 ///
     24 /// Scheduler's queue usage:
     25 /// JALU01,  0/20
     26 /// JFPU01,  18/18
     27 /// JLSAGU,  0/12
     28 ///
     29 //===----------------------------------------------------------------------===//
     30 
     31 #ifndef LLVM_TOOLS_LLVM_MCA_SCHEDULERSTATISTICS_H
     32 #define LLVM_TOOLS_LLVM_MCA_SCHEDULERSTATISTICS_H
     33 
     34 #include "View.h"
     35 #include "llvm/ADT/SmallVector.h"
     36 #include "llvm/MC/MCSubtargetInfo.h"
     37 #include <map>
     38 
     39 namespace mca {
     40 
     41 class SchedulerStatistics : public View {
     42   const llvm::MCSchedModel &SM;
     43 
     44   using Histogram = std::map<unsigned, unsigned>;
     45   Histogram IssuedPerCycle;
     46 
     47   unsigned NumIssued;
     48   unsigned NumCycles;
     49 
     50   // Tracks the usage of a scheduler's queue.
     51   struct BufferUsage {
     52     unsigned SlotsInUse;
     53     unsigned MaxUsedSlots;
     54   };
     55 
     56   std::map<unsigned, BufferUsage> BufferedResources;
     57 
     58   void updateHistograms() {
     59     IssuedPerCycle[NumIssued]++;
     60     NumIssued = 0;
     61   }
     62 
     63   void printSchedulerStatistics(llvm::raw_ostream &OS) const;
     64   void printSchedulerUsage(llvm::raw_ostream &OS) const;
     65 
     66 public:
     67   SchedulerStatistics(const llvm::MCSubtargetInfo &STI)
     68       : SM(STI.getSchedModel()), NumIssued(0), NumCycles(0) {}
     69 
     70   void onEvent(const HWInstructionEvent &Event) override;
     71 
     72   void onCycleBegin() override { NumCycles++; }
     73 
     74   void onCycleEnd() override { updateHistograms(); }
     75 
     76   // Increases the number of used scheduler queue slots of every buffered
     77   // resource in the Buffers set.
     78   void onReservedBuffers(llvm::ArrayRef<unsigned> Buffers) override;
     79 
     80   // Decreases by one the number of used scheduler queue slots of every
     81   // buffered resource in the Buffers set.
     82   void onReleasedBuffers(llvm::ArrayRef<unsigned> Buffers) override;
     83 
     84   void printView(llvm::raw_ostream &OS) const override {
     85     printSchedulerStatistics(OS);
     86     printSchedulerUsage(OS);
     87   }
     88 };
     89 } // namespace mca
     90 
     91 #endif
     92