llvm-project/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.h

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3.0 KiB
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//===-- BenchmarkRunner.h ---------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
///
/// \file
/// Defines the abstract BenchmarkRunner class for measuring a certain execution
/// property of instructions (e.g. latency).
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRUNNER_H
#define LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRUNNER_H
#include "Assembler.h"
#include "BenchmarkCode.h"
#include "BenchmarkResult.h"
#include "LlvmState.h"
#include "MCInstrDescView.h"
#include "SnippetRepetitor.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/MC/MCInst.h"
#include "llvm/Support/Error.h"
#include <cstdlib>
#include <memory>
#include <vector>
namespace llvm {
namespace exegesis {
// Common code for all benchmark modes.
class BenchmarkRunner {
public:
explicit BenchmarkRunner(const LLVMState &State,
InstructionBenchmark::ModeE Mode);
virtual ~BenchmarkRunner();
Expected<InstructionBenchmark>
runConfiguration(const BenchmarkCode &Configuration, unsigned NumRepetitions,
unsigned LoopUnrollFactor,
ArrayRef<std::unique_ptr<const SnippetRepetitor>> Repetitors,
bool DumpObjectToDisk) const;
// Scratch space to run instructions that touch memory.
struct ScratchSpace {
static constexpr const size_t kAlignment = 1024;
static constexpr const size_t kSize = 1 << 20; // 1MB.
ScratchSpace()
: UnalignedPtr(std::make_unique<char[]>(kSize + kAlignment)),
AlignedPtr(
UnalignedPtr.get() + kAlignment -
(reinterpret_cast<intptr_t>(UnalignedPtr.get()) % kAlignment)) {}
char *ptr() const { return AlignedPtr; }
void clear() { std::memset(ptr(), 0, kSize); }
private:
const std::unique_ptr<char[]> UnalignedPtr;
char *const AlignedPtr;
};
// A helper to measure counters while executing a function in a sandboxed
// context.
class FunctionExecutor {
public:
virtual ~FunctionExecutor();
// FIXME deprecate this.
virtual Expected<int64_t> runAndMeasure(const char *Counters) const = 0;
virtual Expected<llvm::SmallVector<int64_t, 4>>
runAndSample(const char *Counters) const = 0;
};
protected:
const LLVMState &State;
const InstructionBenchmark::ModeE Mode;
private:
virtual Expected<std::vector<BenchmarkMeasure>>
runMeasurements(const FunctionExecutor &Executor) const = 0;
Expected<std::string> writeObjectFile(const BenchmarkCode &Configuration,
const FillFunction &Fill) const;
const std::unique_ptr<ScratchSpace> Scratch;
};
} // namespace exegesis
} // namespace llvm
#endif // LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRUNNER_H