tools/llvm-exegesis/lib/Analysis.h

   1 //===-- Analysis.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 ///
  10 /// \file
  11 /// Analysis output for benchmark results.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_TOOLS_LLVM_EXEGESIS_ANALYSIS_H
  16 #define LLVM_TOOLS_LLVM_EXEGESIS_ANALYSIS_H
  17
  18 #include "Clustering.h"
  19 #include "llvm/MC/MCContext.h"
  20 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
  21 #include "llvm/MC/MCInstPrinter.h"
  22 #include "llvm/MC/MCInstrInfo.h"
  23 #include "llvm/MC/MCObjectFileInfo.h"
  24 #include "llvm/MC/MCSubtargetInfo.h"
  25 #include "llvm/Support/Error.h"
  26 #include "llvm/Support/TargetRegistry.h"
  27 #include "llvm/Support/raw_ostream.h"
  28 #include <memory>
  29 #include <set>
  30 #include <string>
  31 #include <unordered_map>
  32
  33 namespace llvm {
  34 namespace exegesis {
  35
  36 // A helper class to analyze benchmark results for a target.
  37 class Analysis {
  38 public:
  39   Analysis(const llvm::Target &Target,
  40            const InstructionBenchmarkClustering &Clustering);
  41
  42   // Prints a csv of instructions for each cluster.
  43   struct PrintClusters {};
  44   // Find potential errors in the scheduling information given measurements.
  45   struct PrintSchedClassInconsistencies {};
  46
  47   template <typename Pass> llvm::Error run(llvm::raw_ostream &OS) const;
  48
  49 private:
  50   using ClusterId = InstructionBenchmarkClustering::ClusterId;
  51
  52   // An llvm::MCSchedClassDesc augmented with some additional data.
  53   struct ResolvedSchedClass {
  54     ResolvedSchedClass(const llvm::MCSubtargetInfo &STI,
  55                        unsigned ResolvedSchedClassId, bool WasVariant);
  56
  57     const unsigned SchedClassId;
  58     const llvm::MCSchedClassDesc *const SCDesc;
  59     const bool WasVariant; // Whether the original class was variant.
  60     const llvm::SmallVector<llvm::MCWriteProcResEntry, 8>
  61         NonRedundantWriteProcRes;
  62     const std::vector<std::pair<uint16_t, float>> IdealizedProcResPressure;
  63   };
  64
  65   // Represents the intersection of a sched class and a cluster.
  66   class SchedClassCluster {
  67   public:
  68     const InstructionBenchmarkClustering::ClusterId &id() const {
  69       return ClusterId;
  70     }
  71
  72     const std::vector<size_t> &getPointIds() const { return PointIds; }
  73
  74     // Return the cluster centroid.
  75     const std::vector<PerInstructionStats> &getRepresentative() const {
  76       return Representative;
  77     }
  78
  79     // Returns true if the cluster representative measurements match that of SC.
  80     bool
  81     measurementsMatch(const llvm::MCSubtargetInfo &STI,
  82                       const ResolvedSchedClass &SC,
  83                       const InstructionBenchmarkClustering &Clustering) const;
  84
  85     void addPoint(size_t PointId,
  86                   const InstructionBenchmarkClustering &Clustering);
  87
  88   private:
  89     InstructionBenchmarkClustering::ClusterId ClusterId;
  90     std::vector<size_t> PointIds;
  91     // Measurement stats for the points in the SchedClassCluster.
  92     std::vector<PerInstructionStats> Representative;
  93   };
  94
  95   void printInstructionRowCsv(size_t PointId, llvm::raw_ostream &OS) const;
  96
  97   void
  98   printSchedClassClustersHtml(const std::vector<SchedClassCluster> &Clusters,
  99                               const ResolvedSchedClass &SC,
 100                               llvm::raw_ostream &OS) const;
 101   void printSchedClassDescHtml(const ResolvedSchedClass &SC,
 102                                llvm::raw_ostream &OS) const;
 103
 104   // A pair of (Sched Class, indices of points that belong to the sched
 105   // class).
 106   struct ResolvedSchedClassAndPoints {
 107     explicit ResolvedSchedClassAndPoints(ResolvedSchedClass &&RSC);
 108
 109     ResolvedSchedClass RSC;
 110     std::vector<size_t> PointIds;
 111   };
 112
 113   // Builds a list of ResolvedSchedClassAndPoints.
 114   std::vector<ResolvedSchedClassAndPoints> makePointsPerSchedClass() const;
 115
 116   template <typename EscapeTag, EscapeTag Tag>
 117   void writeSnippet(llvm::raw_ostream &OS, llvm::ArrayRef<uint8_t> Bytes,
 118                     const char *Separator) const;
 119
 120   const InstructionBenchmarkClustering &Clustering_;
 121   llvm::MCObjectFileInfo ObjectFileInfo_;
 122   std::unique_ptr<llvm::MCContext> Context_;
 123   std::unique_ptr<llvm::MCSubtargetInfo> SubtargetInfo_;
 124   std::unique_ptr<llvm::MCInstrInfo> InstrInfo_;
 125   std::unique_ptr<llvm::MCRegisterInfo> RegInfo_;
 126   std::unique_ptr<llvm::MCAsmInfo> AsmInfo_;
 127   std::unique_ptr<llvm::MCInstPrinter> InstPrinter_;
 128   std::unique_ptr<llvm::MCDisassembler> Disasm_;
 129 };
 130
 131 // Computes the idealized ProcRes Unit pressure. This is the expected
 132 // distribution if the CPU scheduler can distribute the load as evenly as
 133 // possible.
 134 std::vector<std::pair<uint16_t, float>> computeIdealizedProcResPressure(
 135     const llvm::MCSchedModel &SM,
 136     llvm::SmallVector<llvm::MCWriteProcResEntry, 8> WPRS);
 137
 138 } // namespace exegesis
 139 } // namespace llvm
 140
 141 #endif // LLVM_TOOLS_LLVM_EXEGESIS_CLUSTERING_H