tools/llvm-mca/Views/SchedulerStatistics.h

   1 //===--------------------- SchedulerStatistics.h ----------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 /// \file
   9 ///
  10 /// This file defines class SchedulerStatistics. Class SchedulerStatistics is a
  11 /// View that listens to instruction issue events in order to print general
  12 /// statistics related to the hardware schedulers.
  13 ///
  14 /// Example:
  15 /// ========
  16 ///
  17 /// Schedulers - number of cycles where we saw N instructions issued:
  18 /// [# issued], [# cycles]
  19 ///  0,          6  (2.9%)
  20 ///  1,          106  (50.7%)
  21 ///  2,          97  (46.4%)
  22 ///
  23 /// Scheduler's queue usage:
  24 /// [1] Resource name.
  25 /// [2] Average number of used buffer entries.
  26 /// [3] Maximum number of used buffer entries.
  27 /// [4] Total number of buffer entries.
  28 ///
  29 ///  [1]            [2]        [3]        [4]
  30 /// JALU01           0          0          20
  31 /// JFPU01           15         18         18
  32 /// JLSAGU           0          0          12
  33 //
  34 //===----------------------------------------------------------------------===//
  35
  36 #ifndef LLVM_TOOLS_LLVM_MCA_SCHEDULERSTATISTICS_H
  37 #define LLVM_TOOLS_LLVM_MCA_SCHEDULERSTATISTICS_H
  38
  39 #include "Views/View.h"
  40 #include "llvm/ADT/SmallVector.h"
  41 #include "llvm/MC/MCSubtargetInfo.h"
  42 #include <map>
  43
  44 namespace llvm {
  45 namespace mca {
  46
  47 class SchedulerStatistics final : public View {
  48   const llvm::MCSchedModel &SM;
  49   unsigned LQResourceID;
  50   unsigned SQResourceID;
  51
  52   unsigned NumIssued;
  53   unsigned NumCycles;
  54
  55   unsigned MostRecentLoadDispatched;
  56   unsigned MostRecentStoreDispatched;
  57
  58   // Tracks the usage of a scheduler's queue.
  59   struct BufferUsage {
  60     unsigned SlotsInUse;
  61     unsigned MaxUsedSlots;
  62     uint64_t CumulativeNumUsedSlots;
  63   };
  64
  65   using Histogram = std::map<unsigned, unsigned>;
  66   Histogram IssueWidthPerCycle;
  67
  68   std::vector<BufferUsage> Usage;
  69
  70   void updateHistograms();
  71   void printSchedulerStats(llvm::raw_ostream &OS) const;
  72   void printSchedulerUsage(llvm::raw_ostream &OS) const;
  73
  74 public:
  75   SchedulerStatistics(const llvm::MCSubtargetInfo &STI);
  76   void onEvent(const HWInstructionEvent &Event) override;
  77   void onCycleBegin() override { NumCycles++; }
  78   void onCycleEnd() override { updateHistograms(); }
  79
  80   // Increases the number of used scheduler queue slots of every buffered
  81   // resource in the Buffers set.
  82   void onReservedBuffers(const InstRef &IR,
  83                          llvm::ArrayRef<unsigned> Buffers) override;
  84
  85   // Decreases by one the number of used scheduler queue slots of every
  86   // buffered resource in the Buffers set.
  87   void onReleasedBuffers(const InstRef &IR,
  88                          llvm::ArrayRef<unsigned> Buffers) override;
  89
  90   void printView(llvm::raw_ostream &OS) const override;
  91 };
  92 } // namespace mca
  93 } // namespace llvm
  94
  95 #endif