[llvm-exegesis][NFC] Split BenchmarkRunner class

Summary:
The snippet-generation part goes to the SnippetGenerator class.

This will allow benchmarking arbitrary code (see PR38437).

Reviewers: gchatelet

Subscribers: mgorny, tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D51979

llvm-svn: 342117

1 files changed, 33 insertions, 4 deletions

diff --git a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
index 6b626b0eaa3..1465d142379 100644
--- a/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
+++ b/llvm/tools/llvm-exegesis/llvm-exegesis.cpp
@@ -119,6 +119,30 @@ getBenchmarkResultContext(const LLVMState &State) {
   return Ctx;
 }
 
+// Generates code snippets for opcode `Opcode`.
+llvm::Expected<std::vector<BenchmarkCode>>
+generateSnippets(const LLVMState &State, unsigned Opcode,
+                 unsigned NumRepetitions) {
+  const std::unique_ptr<SnippetGenerator> Generator =
+      State.getExegesisTarget().createSnippetGenerator(BenchmarkMode, State);
+  if (!Generator) {
+    llvm::report_fatal_error("cannot create snippet generator");
+  }
+
+  const llvm::MCInstrDesc &InstrDesc = State.getInstrInfo().get(Opcode);
+  // Ignore instructions that we cannot run.
+  if (InstrDesc.isPseudo())
+    return llvm::make_error<BenchmarkFailure>("Unsupported opcode: isPseudo");
+  if (InstrDesc.isBranch() || InstrDesc.isIndirectBranch())
+    return llvm::make_error<BenchmarkFailure>(
+        "Unsupported opcode: isBranch/isIndirectBranch");
+  if (InstrDesc.isCall() || InstrDesc.isReturn())
+    return llvm::make_error<BenchmarkFailure>(
+        "Unsupported opcode: isCall/isReturn");
+
+  return Generator->generateConfigurations(Opcode);
+}
+
 void benchmarkMain() {
   if (exegesis::pfm::pfmInitialize())
     llvm::report_fatal_error("cannot initialize libpfm");
@@ -140,6 +164,10 @@ void benchmarkMain() {
     return;
   }
 
+  // FIXME: Allow arbitrary code.
+  const std::vector<BenchmarkCode> Configurations =
+      ExitOnErr(generateSnippets(State, Opcode, NumRepetitions));
+
   const std::unique_ptr<BenchmarkRunner> Runner =
       State.getExegesisTarget().createBenchmarkRunner(BenchmarkMode, State);
   if (!Runner) {
@@ -154,11 +182,12 @@ void benchmarkMain() {
     BenchmarkFile = "-";
 
   const BenchmarkResultContext Context = getBenchmarkResultContext(State);
-  std::vector<InstructionBenchmark> Results =
-      ExitOnErr(Runner->run(Opcode, NumRepetitions));
-  for (InstructionBenchmark &Result : Results)
-    ExitOnErr(Result.writeYaml(Context, BenchmarkFile));
 
+  for (const BenchmarkCode &Conf : Configurations) {
+    InstructionBenchmark Result =
+        Runner->runConfiguration(Conf, NumRepetitions);
+    ExitOnErr(Result.writeYaml(Context, BenchmarkFile));
+  }
   exegesis::pfm::pfmTerminate();
 }