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

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4.0 KiB
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//===-- BenchmarkResult.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 classes to represent measurements and serialize/deserialize them to
// Yaml.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRESULT_H
#define LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRESULT_H
#include "LlvmState.h"
#include "RegisterValue.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/Support/YAMLTraits.h"
#include <limits>
#include <string>
#include <unordered_map>
#include <vector>
namespace llvm {
class Error;
namespace exegesis {
struct InstructionBenchmarkKey {
// The LLVM opcode name.
std::vector<MCInst> Instructions;
// The initial values of the registers.
std::vector<RegisterValue> RegisterInitialValues;
// An opaque configuration, that can be used to separate several benchmarks of
// the same instruction under different configurations.
std::string Config;
};
struct BenchmarkMeasure {
// A helper to create an unscaled BenchmarkMeasure.
static BenchmarkMeasure Create(std::string Key, double Value) {
return {Key, Value, Value};
}
std::string Key;
// This is the per-instruction value, i.e. measured quantity scaled per
// instruction.
double PerInstructionValue;
// This is the per-snippet value, i.e. measured quantity for one repetition of
// the whole snippet.
double PerSnippetValue;
};
// The result of an instruction benchmark.
struct InstructionBenchmark {
InstructionBenchmarkKey Key;
enum ModeE { Unknown, Latency, Uops, InverseThroughput };
ModeE Mode;
std::string CpuName;
std::string LLVMTriple;
// Which instruction is being benchmarked here?
const MCInst &keyInstruction() const { return Key.Instructions[0]; }
// The number of instructions inside the repeated snippet. For example, if a
// snippet of 3 instructions is repeated 4 times, this is 12.
unsigned NumRepetitions = 0;
enum RepetitionModeE { Duplicate, Loop, AggregateMin };
// Note that measurements are per instruction.
std::vector<BenchmarkMeasure> Measurements;
std::string Error;
std::string Info;
std::vector<uint8_t> AssembledSnippet;
// How to aggregate measurements.
enum ResultAggregationModeE { Min, Max, Mean, MinVariance };
// Read functions.
static Expected<InstructionBenchmark> readYaml(const LLVMState &State,
StringRef Filename);
static Expected<std::vector<InstructionBenchmark>>
readYamls(const LLVMState &State, StringRef Filename);
class Error readYamlFrom(const LLVMState &State, StringRef InputContent);
// Write functions, non-const because of YAML traits.
class Error writeYamlTo(const LLVMState &State, raw_ostream &S);
class Error writeYaml(const LLVMState &State, const StringRef Filename);
};
bool operator==(const BenchmarkMeasure &A, const BenchmarkMeasure &B);
//------------------------------------------------------------------------------
// Utilities to work with Benchmark measures.
// A class that measures stats over benchmark measures.
class PerInstructionStats {
public:
void push(const BenchmarkMeasure &BM);
double avg() const {
assert(NumValues);
return SumValues / NumValues;
}
double min() const { return MinValue; }
double max() const { return MaxValue; }
const std::string &key() const { return Key; }
private:
std::string Key;
double SumValues = 0.0;
int NumValues = 0;
double MaxValue = std::numeric_limits<double>::min();
double MinValue = std::numeric_limits<double>::max();
};
} // namespace exegesis
} // namespace llvm
#endif // LLVM_TOOLS_LLVM_EXEGESIS_BENCHMARKRESULT_H