[llvm-exegesis] Write out inconsistencies to a file.

[gchatelet]

tools/llvm-exegesis/llvm-exegesis.cpp

177–181

Since there's no performance issue here, I'd rather separate the report generation from saving it:

std::string ClusterReport;
if (auto Err = Analyzer.printClusters(llvm::raw_string_ostream(ClusterReport))) {
  PrintAnalysis("analysis clusters", AnalysisClustersFile, ClusterReport );
}

std::string InconsistenciesReport;
if (auto Err = Analyzer.printClusters(llvm::raw_string_ostream(InconsistenciesReport))) {
  PrintAnalysis("sched class consistency analysis", AnalysisInconsistenciesFile, InconsistenciesReport );
}

[courbet]

Slightly better approach for analysis pass selection.

[courbet]

remove accidentally added file

[courbet]

clang-format

[courbet]

cosmetics

docs/CommandGuide/llvm-exegesis.rst

 instruction.
 The code snippet is jitted and executed on the host subtarget. The time taken
 (resp. resource usage) is measured using hardware performance counters. The
 result is printed out as YAML to the standard output.
 
 The main goal of this tool is to automatically (in)validate the LLVM's TableDef
 scheduling models.
 
+EXAMPLES
+--------
+
+ - Runnin
+
+
+
 OPTIONS
 -------
 
 .. option:: -help
 
  Print a summary of command line options.
 
 .. option:: -opcode-index=<LLVM opcode index>
 
  Specify the opcode to measure, by index.
  Either `opcode-index` or `opcode-name` must be set.
 
 .. option:: -opcode-name=<LLVM opcode name>
 
  Specify the opcode to measure, by name.
  Either `opcode-index` or `opcode-name` must be set.
 
-.. option:: -benchmark-mode=[Latency|Uops]
+.. option:: -mode=[latency|uops|analysis]
 
- Specify which characteristic of the opcode to measure.
+ Specify the operation mode. See the tool description for more information.
 
 .. option:: -num-repetitions=<Number of repetition>
 
  Specify the number of repetitions of the asm snippet.
  Higher values lead to more accurate measurements but lengthen the benchmark.
 
 
 EXIT STATUS
 -----------
 
 :program:`llvm-exegesis` returns 0 on success. Otherwise, an error message is
 printed to standard error, and the tool returns a non 0 value.

tools/llvm-exegesis/lib/Analysis.h

 
 // A helper class to analyze benchmark results for a target.
 class Analysis {
 public:
   Analysis(const llvm::Target &Target,
            const InstructionBenchmarkClustering &Clustering);
 
   // Prints a csv of instructions for each cluster.
-  llvm::Error printClusters(llvm::raw_ostream &OS) const;
-
+  struct PrintClusters {};
   // Find potential errors in the scheduling information given measurements.
-  llvm::Error printSchedClassInconsistencies(llvm::raw_ostream &OS) const;
+  struct PrintSchedClassInconsistencies {};
+
+  template <typename Pass>
+  llvm::Error run(llvm::raw_ostream &OS) const;
 
 private:
   void printInstructionRow(bool PrintSchedClass, size_t PointId,
                            llvm::raw_ostream &OS) const;
 
   // Builds a map of Sched Class -> indices of points that belong to the sched
   // class.
   std::unordered_map<unsigned, std::vector<size_t>>

tools/llvm-exegesis/lib/Analysis.cpp

Analysis::Analysis(const llvm::Target &Target,
   SubtargetInfo_.reset(Target.createMCSubtargetInfo(FirstPoint.LLVMTriple,
                                                     FirstPoint.CpuName, ""));
 
   // Build an index of mnemonic->opcode.
   for (int I = 0, E = InstrInfo_->getNumOpcodes(); I < E; ++I)
     MnemonicToOpcode_.emplace(InstrInfo_->getName(I), I);
 }
 
-llvm::Error Analysis::printClusters(llvm::raw_ostream &OS) const {
+template <>
+llvm::Error Analysis::run<Analysis::PrintClusters>(llvm::raw_ostream &OS) const {
   if (Clustering_.getPoints().empty())
     return llvm::Error::success();
 
   // Write the header.
   OS << "cluster_id" << kCsvSep << "opcode_name" << kCsvSep << "config"
      << kCsvSep << "sched_class";
   for (const auto &Measurement : Clustering_.getPoints().front().Measurements) {
     OS << kCsvSep;
if (OpcodeIt == MnemonicToOpcode_.end())
       continue;
     const unsigned SchedClassId =
         InstrInfo_->get(OpcodeIt->second).getSchedClass();
     PointsPerSchedClass[SchedClassId].push_back(PointId);
   }
   return PointsPerSchedClass;
 }
 
-llvm::Error
-Analysis::printSchedClassInconsistencies(llvm::raw_ostream &OS) const {
+template <>
+llvm::Error Analysis::run<Analysis::PrintSchedClassInconsistencies>(llvm::raw_ostream &OS) const {
   // All the points in a scheduling class should be in the same cluster.
   // Print any scheduling class for which this is not the case.
   for (const auto &SchedClassAndPoints : makePointsPerSchedClass()) {
     std::unordered_set<size_t> ClustersForSchedClass;
     for (const size_t PointId : SchedClassAndPoints.second) {
       const auto &ClusterId = Clustering_.getClusterIdForPoint(PointId);
       if (!ClusterId.isValid())
         continue; // Ignore noise and errors.
OS << " contains instructions with distinct performance "
        << ClustersForSchedClass.size() << " clusters:\n";
     for (const size_t PointId : SchedClassAndPoints.second) {
       printInstructionRow(/*PrintSchedClass*/ false, PointId, OS);
     }
   }
   return llvm::Error::success();
 }
 
+template llvm::Error
+Analysis::run<Analysis::PrintClusters>(llvm::raw_ostream &OS) const;
+template llvm::Error Analysis::run<Analysis::PrintSchedClassInconsistencies>(
+    llvm::raw_ostream &OS) const;
+
 } // namespace exegesis

tools/llvm-exegesis/llvm-exegesis.cpp

static llvm::cl::opt<unsigned> AnalysisNumPoints(
     llvm::cl::desc("minimum number of points in an analysis cluster"),
     llvm::cl::init(3));
 
 static llvm::cl::opt<float>
     AnalysisEpsilon("analysis-epsilon",
                     llvm::cl::desc("dbscan epsilon for analysis clustering"),
                     llvm::cl::init(0.1));
 
-static llvm::cl::opt<std::string> AnalysisClustersFile("analysis-clusters-file",
-                                                       llvm::cl::desc(""),
-                                                       llvm::cl::init("-"));
+static llvm::cl::opt<std::string>
+    AnalysisClustersOutputFile("analysis-clusters-output-file", llvm::cl::desc(""),
+static llvm::cl::opt<std::string>
+    AnalysisInconsistenciesOutputFile("analysis-inconsistencies-output-file",
+                                      llvm::cl::desc(""), llvm::cl::init("-"));
 
 namespace exegesis {
 
 static unsigned GetOpcodeOrDie(const llvm::MCInstrInfo &MCInstrInfo) {
   if (OpcodeName.empty() && (OpcodeIndex == 0))
     llvm::report_fatal_error(
         "please provide one and only one of 'opcode-index' or 'opcode-name'");
   if (OpcodeIndex > 0)
void benchmarkMain() {
   if (NumRepetitions == 0)
     llvm::report_fatal_error("--num-repetitions must be greater than zero");
 
   Runner->run(GetOpcodeOrDie(State.getInstrInfo()), Filter, NumRepetitions)
       .writeYamlOrDie(BenchmarkFile);
   exegesis::pfm::pfmTerminate();
 }
 
+// Prints the results of running analysis printer `Print` to file `Filename` if
+// Filename is non-empty.
+template <typename Pass>
+void maybeRunAnalysis(const Analysis &Analyzer, const std::string &Name,
+                      const std::string &OutputFilename) {
+  if (OutputFilename.empty())
+    return;
+  if (OutputFilename != "-") {
+    llvm::errs() << "Printing " << Name << " results to file '" << OutputFilename
+                 << "'\n";
+  }
+  std::error_code ErrorCode;
+  llvm::raw_fd_ostream ClustersOS(OutputFilename, ErrorCode, llvm::sys::fs::F_RW);
+  if (ErrorCode)
+    llvm::report_fatal_error("cannot open out file: " + OutputFilename);
+  if (auto Err = Analyzer.run<Pass>(ClustersOS))
+    llvm::report_fatal_error(std::move(Err));
+}
+
 void analysisMain() {
   // Read benchmarks.
   const std::vector<InstructionBenchmark> Points =
       InstructionBenchmark::readYamlsOrDie(BenchmarkFile);
   llvm::outs() << "Parsed " << Points.size() << " benchmark points\n";
   if (Points.empty()) {
     llvm::errs() << "no benchmarks to analyze\n";
     return;
if (!TheTarget) {
     llvm::errs() << "unknown target '" << Points[0].LLVMTriple << "'\n";
     return;
   }
   const auto Clustering = llvm::cantFail(InstructionBenchmarkClustering::create(
       Points, AnalysisNumPoints, AnalysisEpsilon));
 
   const Analysis Analyzer(*TheTarget, Clustering);
 
-  std::error_code ErrorCode;
-  llvm::raw_fd_ostream ClustersOS(AnalysisClustersFile, ErrorCode,
-                                  llvm::sys::fs::F_RW);
-  if (ErrorCode)
-    llvm::report_fatal_error("cannot open out file: " + AnalysisClustersFile);
-
-  if (auto Err = Analyzer.printClusters(ClustersOS))
-    llvm::report_fatal_error(std::move(Err));
-
-  if (auto Err = Analyzer.printSchedClassInconsistencies(llvm::outs()))
-    llvm::report_fatal_error(std::move(Err));
+  maybeRunAnalysis<Analysis::PrintClusters>(Analyzer, "analysis clusters",
+                                            AnalysisClustersOutputFile);
+  maybeRunAnalysis<Analysis::PrintSchedClassInconsistencies>(
+      Analyzer, "sched class consistency analysis",
+      AnalysisInconsistenciesOutputFile);
 }
 
 } // namespace exegesis
 
 int main(int Argc, char **Argv) {
   llvm::cl::ParseCommandLineOptions(Argc, Argv, "");
 
   if (BenchmarkMode == BenchmarkModeE::Analysis) {
     exegesis::analysisMain();
   } else {
     exegesis::benchmarkMain();
   }
   return EXIT_SUCCESS;
 }