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