177 lines · cpp
1//===-- Benchmark function tests -----------------------------------------===//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-exception6//7//===----------------------------------------------------------------------===//8 9#include "LibcBenchmark.h"10#include "llvm/ADT/ArrayRef.h"11#include "llvm/ADT/SmallVector.h"12#include "gmock/gmock.h"13#include "gtest/gtest.h"14#include <chrono>15#include <limits>16#include <optional>17#include <queue>18#include <vector>19 20using std::chrono::nanoseconds;21using ::testing::ElementsAre;22using ::testing::Field;23using ::testing::IsEmpty;24using ::testing::SizeIs;25 26namespace llvm {27namespace libc_benchmarks {28namespace {29 30// A simple parameter provider returning a zero initialized vector of size31// `iterations`.32struct DummyParameterProvider {33 std::vector<char> generateBatch(size_t iterations) {34 return std::vector<char>(iterations);35 }36};37 38class LibcBenchmark : public ::testing::Test {39public:40 // A Clock interface suitable for testing.41 // - Either it returns 0,42 // - Or a timepoint coming from the `setMeasurements` call.43 Duration now() {44 if (!MaybeTimepoints)45 return {};46 assert(!MaybeTimepoints->empty());47 const Duration timepoint = MaybeTimepoints->front();48 MaybeTimepoints->pop();49 return timepoint;50 }51 52protected:53 void SetUp() override { Options.Log = BenchmarkLog::Full; }54 55 void TearDown() override {56 // We make sure all the expected measurements were performed.57 if (MaybeTimepoints)58 EXPECT_THAT(*MaybeTimepoints, IsEmpty());59 }60 61 BenchmarkResult run() {62 return benchmark(Options, ParameterProvider, DummyFunction, *this);63 }64 65 void setMeasurements(llvm::ArrayRef<Duration> Durations) {66 MaybeTimepoints.emplace(); // Create the optional value.67 Duration CurrentTime = nanoseconds(1);68 for (const auto &Duration : Durations) {69 MaybeTimepoints->push(CurrentTime);70 CurrentTime += Duration;71 MaybeTimepoints->push(CurrentTime);72 CurrentTime += nanoseconds(1);73 }74 }75 76 BenchmarkOptions Options;77 78private:79 DummyParameterProvider ParameterProvider;80 static char DummyFunction(char Payload) { return Payload; }81 std::optional<std::queue<Duration>> MaybeTimepoints;82};83 84TEST_F(LibcBenchmark, MaxSamplesReached) {85 Options.MaxSamples = 1;86 const auto Result = run();87 EXPECT_THAT(Result.MaybeBenchmarkLog->size(), 1);88 EXPECT_THAT(Result.TerminationStatus, BenchmarkStatus::MaxSamplesReached);89}90 91TEST_F(LibcBenchmark, MaxDurationReached) {92 Options.MaxDuration = nanoseconds(10);93 setMeasurements({nanoseconds(11)});94 const auto Result = run();95 EXPECT_THAT(Result.MaybeBenchmarkLog->size(), 1);96 EXPECT_THAT(Result.TerminationStatus, BenchmarkStatus::MaxDurationReached);97}98 99TEST_F(LibcBenchmark, MaxIterationsReached) {100 Options.InitialIterations = 1;101 Options.MaxIterations = 20;102 Options.ScalingFactor = 2;103 Options.Epsilon = 0; // unreachable.104 const auto Result = run();105 EXPECT_THAT(*Result.MaybeBenchmarkLog,106 ElementsAre(Field(&BenchmarkState::LastSampleIterations, 1),107 Field(&BenchmarkState::LastSampleIterations, 2),108 Field(&BenchmarkState::LastSampleIterations, 4),109 Field(&BenchmarkState::LastSampleIterations, 8),110 Field(&BenchmarkState::LastSampleIterations, 16),111 Field(&BenchmarkState::LastSampleIterations, 32)));112 EXPECT_THAT(Result.MaybeBenchmarkLog->size(), 6);113 EXPECT_THAT(Result.TerminationStatus, BenchmarkStatus::MaxIterationsReached);114}115 116TEST_F(LibcBenchmark, MinSamples) {117 Options.MinSamples = 4;118 Options.ScalingFactor = 2;119 Options.Epsilon = std::numeric_limits<double>::max(); // always reachable.120 setMeasurements(121 {nanoseconds(1), nanoseconds(2), nanoseconds(4), nanoseconds(8)});122 const auto Result = run();123 EXPECT_THAT(*Result.MaybeBenchmarkLog,124 ElementsAre(Field(&BenchmarkState::LastSampleIterations, 1),125 Field(&BenchmarkState::LastSampleIterations, 2),126 Field(&BenchmarkState::LastSampleIterations, 4),127 Field(&BenchmarkState::LastSampleIterations, 8)));128 EXPECT_THAT(Result.MaybeBenchmarkLog->size(), 4);129 EXPECT_THAT(Result.TerminationStatus, BenchmarkStatus::PrecisionReached);130}131 132TEST_F(LibcBenchmark, Epsilon) {133 Options.MinSamples = 4;134 Options.ScalingFactor = 2;135 Options.Epsilon = std::numeric_limits<double>::max(); // always reachable.136 setMeasurements(137 {nanoseconds(1), nanoseconds(2), nanoseconds(4), nanoseconds(8)});138 const auto Result = run();139 EXPECT_THAT(*Result.MaybeBenchmarkLog,140 ElementsAre(Field(&BenchmarkState::LastSampleIterations, 1),141 Field(&BenchmarkState::LastSampleIterations, 2),142 Field(&BenchmarkState::LastSampleIterations, 4),143 Field(&BenchmarkState::LastSampleIterations, 8)));144 EXPECT_THAT(Result.MaybeBenchmarkLog->size(), 4);145 EXPECT_THAT(Result.TerminationStatus, BenchmarkStatus::PrecisionReached);146}147 148TEST(ArrayRefLoop, Cycle) {149 std::array<int, 2> array = {1, 2};150 EXPECT_THAT(cycle(array, 0), ElementsAre());151 EXPECT_THAT(cycle(array, 1), ElementsAre(1));152 EXPECT_THAT(cycle(array, 2), ElementsAre(1, 2));153 EXPECT_THAT(cycle(array, 3), ElementsAre(1, 2, 1));154 EXPECT_THAT(cycle(array, 4), ElementsAre(1, 2, 1, 2));155 EXPECT_THAT(cycle(array, 5), ElementsAre(1, 2, 1, 2, 1));156}157 158TEST(ByteConstrainedArray, Simple) {159 EXPECT_THAT((ByteConstrainedArray<char, 17>()), SizeIs(17));160 EXPECT_THAT((ByteConstrainedArray<uint16_t, 17>()), SizeIs(8));161 EXPECT_THAT((ByteConstrainedArray<uint32_t, 17>()), SizeIs(4));162 EXPECT_THAT((ByteConstrainedArray<uint64_t, 17>()), SizeIs(2));163 164 EXPECT_LE(sizeof(ByteConstrainedArray<char, 17>), 17U);165 EXPECT_LE(sizeof(ByteConstrainedArray<uint16_t, 17>), 17U);166 EXPECT_LE(sizeof(ByteConstrainedArray<uint32_t, 17>), 17U);167 EXPECT_LE(sizeof(ByteConstrainedArray<uint64_t, 17>), 17U);168}169 170TEST(ByteConstrainedArray, Cycle) {171 ByteConstrainedArray<uint64_t, 17> TwoValues{{1UL, 2UL}};172 EXPECT_THAT(cycle(TwoValues, 5), ElementsAre(1, 2, 1, 2, 1));173}174} // namespace175} // namespace libc_benchmarks176} // namespace llvm177