[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
diff --git a/llvm/tools/llvm-exegesis/lib/Uops.h b/llvm/tools/llvm-exegesis/lib/Uops.h
index 0236cd9..160397a 100644
--- a/llvm/tools/llvm-exegesis/lib/Uops.h
+++ b/llvm/tools/llvm-exegesis/lib/Uops.h
@@ -16,14 +16,14 @@
 #define LLVM_TOOLS_LLVM_EXEGESIS_UOPS_H
 
 #include "BenchmarkRunner.h"
+#include "SnippetGenerator.h"
 
 namespace exegesis {
 
-class UopsBenchmarkRunner : public BenchmarkRunner {
+class UopsSnippetGenerator : public SnippetGenerator {
 public:
-  UopsBenchmarkRunner(const LLVMState &State)
-      : BenchmarkRunner(State, InstructionBenchmark::Uops) {}
-  ~UopsBenchmarkRunner() override;
+  UopsSnippetGenerator(const LLVMState &State) : SnippetGenerator(State) {}
+  ~UopsSnippetGenerator() override;
 
   llvm::Expected<CodeTemplate>
   generateCodeTemplate(unsigned Opcode) const override;
@@ -33,10 +33,6 @@
 private:
   llvm::Error isInfeasible(const llvm::MCInstrDesc &MCInstrDesc) const;
 
-  std::vector<BenchmarkMeasure>
-  runMeasurements(const ExecutableFunction &EF, ScratchSpace &Scratch,
-                  const unsigned NumRepetitions) const override;
-
   // Instantiates memory operands within a snippet.
   // To make computations as parallel as possible, we generate independant
   // memory locations for instructions that load and store. If there are less
@@ -65,6 +61,20 @@
                             std::vector<InstructionBuilder> &Snippet) const;
 };
 
+class UopsBenchmarkRunner : public BenchmarkRunner {
+public:
+  UopsBenchmarkRunner(const LLVMState &State)
+      : BenchmarkRunner(State, InstructionBenchmark::Uops) {}
+  ~UopsBenchmarkRunner() override;
+
+  static constexpr const size_t kMinNumDifferentAddresses = 6;
+
+private:
+  std::vector<BenchmarkMeasure>
+  runMeasurements(const ExecutableFunction &EF, ScratchSpace &Scratch,
+                  const unsigned NumRepetitions) const override;
+};
+
 } // namespace exegesis
 
 #endif // LLVM_TOOLS_LLVM_EXEGESIS_UOPS_H