1 //===-- BenchmarkRunner.h ---------------------------------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 /// 9 /// \file 10 /// Defines the abstract BenchmarkRunner class for measuring a certain execution 11 /// property of instructions (e.g. latency). 12 /// 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRUNNER_H 16 #define LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRUNNER_H 17 18 #include "Assembler.h" 19 #include "BenchmarkCode.h" 20 #include "BenchmarkResult.h" 21 #include "LlvmState.h" 22 #include "MCInstrDescView.h" 23 #include "SnippetRepetitor.h" 24 #include "llvm/ADT/SmallVector.h" 25 #include "llvm/MC/MCInst.h" 26 #include "llvm/Support/Error.h" 27 #include <cstdlib> 28 #include <memory> 29 #include <vector> 30 31 namespace llvm { 32 namespace exegesis { 33 34 // Common code for all benchmark modes. 35 class BenchmarkRunner { 36 public: 37 explicit BenchmarkRunner(const LLVMState &State, 38 InstructionBenchmark::ModeE Mode); 39 40 virtual ~BenchmarkRunner(); 41 42 Expected<InstructionBenchmark> 43 runConfiguration(const BenchmarkCode &Configuration, unsigned NumRepetitions, 44 unsigned LoopUnrollFactor, 45 ArrayRef<std::unique_ptr<const SnippetRepetitor>> Repetitors, 46 bool DumpObjectToDisk) const; 47 48 // Scratch space to run instructions that touch memory. 49 struct ScratchSpace { 50 static constexpr const size_t kAlignment = 1024; 51 static constexpr const size_t kSize = 1 << 20; // 1MB. ScratchSpaceScratchSpace52 ScratchSpace() 53 : UnalignedPtr(std::make_unique<char[]>(kSize + kAlignment)), 54 AlignedPtr( 55 UnalignedPtr.get() + kAlignment - 56 (reinterpret_cast<intptr_t>(UnalignedPtr.get()) % kAlignment)) {} ptrScratchSpace57 char *ptr() const { return AlignedPtr; } clearScratchSpace58 void clear() { std::memset(ptr(), 0, kSize); } 59 60 private: 61 const std::unique_ptr<char[]> UnalignedPtr; 62 char *const AlignedPtr; 63 }; 64 65 // A helper to measure counters while executing a function in a sandboxed 66 // context. 67 class FunctionExecutor { 68 public: 69 virtual ~FunctionExecutor(); 70 // FIXME deprecate this. 71 virtual Expected<int64_t> runAndMeasure(const char *Counters) const = 0; 72 73 virtual Expected<llvm::SmallVector<int64_t, 4>> 74 runAndSample(const char *Counters) const = 0; 75 }; 76 77 protected: 78 const LLVMState &State; 79 const InstructionBenchmark::ModeE Mode; 80 81 private: 82 virtual Expected<std::vector<BenchmarkMeasure>> 83 runMeasurements(const FunctionExecutor &Executor) const = 0; 84 85 Expected<std::string> writeObjectFile(const BenchmarkCode &Configuration, 86 const FillFunction &Fill) const; 87 88 const std::unique_ptr<ScratchSpace> Scratch; 89 }; 90 91 } // namespace exegesis 92 } // namespace llvm 93 94 #endif // LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRUNNER_H 95