[llvm-exegesis] Optionally ignore instructions without a sched class.

[courbet]

Summary

See PR37602.

[RKSimon]

Thanks

docs/CommandGuide/llvm-exegesis.rst

  Specify the numPoints parameters to be used for DBSCAN clustering
  (`analysis` mode).
 
 .. option:: -analysis-espilon=<dbscan epsilon parameter>
 
  Specify the numPoints parameters to be used for DBSCAN clustering
  (`analysis` mode).
 
+ .. option:: -ignore-invalid-sched-class=false
+
+  If set, ignore instructions that do not have a sched class (class idx = 0).
+
 
 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/llvm-exegesis.cpp

llvm::cl::values(
         clEnumValN(BenchmarkModeE::Uops, "uops", "Uop Decomposition"),
         clEnumValN(BenchmarkModeE::Analysis, "analysis", "Analysis")));
 
 static llvm::cl::opt<unsigned>
     NumRepetitions("num-repetitions",
                    llvm::cl::desc("number of time to repeat the asm snippet"),
                    llvm::cl::init(10000));
 
+static llvm::cl::opt<bool> IgnoreInvalidSchedClass(
+    "ignore-invalid-sched-class",
+    llvm::cl::desc("ignore instructions that do not define a sched class"),
+    llvm::cl::init(false));
+
 static llvm::cl::opt<unsigned> AnalysisNumPoints(
     "analysis-numpoints",
     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"),
void benchmarkMain() {
 
   llvm::InitializeNativeTarget();
   llvm::InitializeNativeTargetAsmPrinter();
 
   // FIXME: Target-specific filter.
   X86Filter Filter;
 
   const LLVMState State;
+  const auto Opcode = GetOpcodeOrDie(State.getInstrInfo());
+
+  // Ignore instructions without a sched class if -ignore-invalid-sched-class is
+  // passed.
+  if (IgnoreInvalidSchedClass &&
+      State.getInstrInfo().get(Opcode).getSchedClass() == 0) {
+    llvm::errs() << "ignoring instruction without sched class\n";
+    return;
+  }
 
   // FIXME: Do not require SchedModel for latency.
   if (!State.getSubtargetInfo().getSchedModel().hasExtraProcessorInfo())
     llvm::report_fatal_error("sched model is missing extra processor info!");
 
   std::unique_ptr<BenchmarkRunner> Runner;
   switch (BenchmarkMode) {
   case BenchmarkModeE::Latency:
void benchmarkMain() {
   if (NumRepetitions == 0)
     llvm::report_fatal_error("--num-repetitions must be greater than zero");
 
   // Write to standard output if file is not set.
   if (BenchmarkFile.empty())
     BenchmarkFile = "-";
 
   const BenchmarkResultContext Context = getBenchmarkResultContext(State);
-  std::vector<InstructionBenchmark> Results = ExitOnErr(Runner->run(
-      GetOpcodeOrDie(State.getInstrInfo()), Filter, NumRepetitions));
+  std::vector<InstructionBenchmark> Results =
+      ExitOnErr(Runner->run(Opcode, Filter, NumRepetitions));
   for (InstructionBenchmark &Result : Results)
     ExitOnErr(Result.writeYaml(Context, BenchmarkFile));
 
   exegesis::pfm::pfmTerminate();
 }
 
 // Prints the results of running analysis pass `Pass` to file `OutputFilename`
 // if OutputFilename is non-empty.