175 lines · cpp
1//===----------------------------------------------------------------------===//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// UNSUPPORTED: c++0310 11#include <cstddef>12 13#include "benchmark/benchmark.h"14 15template <std::size_t Depth>16struct Chain : Chain<Depth - 1> {};17 18template <>19struct Chain<0> {20 virtual ~Chain() noexcept = default;21};22 23template <std::size_t Index, std::size_t Depth>24struct Dag : Dag<Index, Depth - 1>, Dag<Index + 1, Depth - 1> {};25 26template <std::size_t Index>27struct Dag<Index, 0> {28 virtual ~Dag() noexcept = default;29};30 31template <std::size_t Depth>32struct VChain : virtual VChain<Depth - 1> {};33 34template <>35struct VChain<0> {36 virtual ~VChain() noexcept = default;37};38 39template <std::size_t Index, std::size_t Depth>40struct VDag : virtual VDag<Index, Depth - 1>, virtual VDag<Index + 1, Depth - 1> {};41 42template <std::size_t Index>43struct VDag<Index, 0> {44 virtual ~VDag() noexcept = default;45};46 47template <typename Dyn, typename From, typename To = Dyn>48static void DynCast(benchmark::State& state) {49 Dyn obj;50 From* from_ptr = &obj;51 for (auto _ : state) {52 To* to_ptr = dynamic_cast<To*>(from_ptr);53 benchmark::DoNotOptimize(to_ptr);54 }55}56 57static void StaticCast(benchmark::State& state) {58 Chain<9> obj;59 Chain<0>* from_ptr = &obj;60 for (auto _ : state) {61 Chain<9>* to_ptr = static_cast<Chain<9>*>(from_ptr);62 benchmark::DoNotOptimize(to_ptr);63 }64}65 66// Downcast along a chain from base to the most derived type67BENCHMARK(DynCast<Chain<1>, Chain<0>>)->Name("Chain, 1 level");68BENCHMARK(DynCast<Chain<2>, Chain<0>>)->Name("Chain, 2 levels");69BENCHMARK(DynCast<Chain<3>, Chain<0>>)->Name("Chain, 3 levels");70BENCHMARK(DynCast<Chain<4>, Chain<0>>)->Name("Chain, 4 levels");71BENCHMARK(DynCast<Chain<5>, Chain<0>>)->Name("Chain, 5 levels");72BENCHMARK(DynCast<Chain<6>, Chain<0>>)->Name("Chain, 6 levels");73BENCHMARK(DynCast<Chain<7>, Chain<0>>)->Name("Chain, 7 levels");74BENCHMARK(DynCast<Chain<8>, Chain<0>>)->Name("Chain, 8 levels");75BENCHMARK(DynCast<Chain<9>, Chain<0>>)->Name("Chain, 9 levels");76 77// Downcast along a chain from base to the middle of the chain78BENCHMARK(DynCast<Chain<2>, Chain<0>, Chain<1>>)->Name("Chain middle, 1 level");79BENCHMARK(DynCast<Chain<4>, Chain<0>, Chain<2>>)->Name("Chain middle, 2 levels");80BENCHMARK(DynCast<Chain<6>, Chain<0>, Chain<3>>)->Name("Chain middle, 3 levels");81BENCHMARK(DynCast<Chain<8>, Chain<0>, Chain<4>>)->Name("Chain middle, 4 levels");82 83// Downcast along a chain that fails84BENCHMARK(DynCast<Chain<1>, Chain<0>, Chain<9>>)->Name("Chain fail, 1 level");85BENCHMARK(DynCast<Chain<2>, Chain<0>, Chain<9>>)->Name("Chain fail, 2 levels");86BENCHMARK(DynCast<Chain<3>, Chain<0>, Chain<9>>)->Name("Chain fail, 3 levels");87BENCHMARK(DynCast<Chain<4>, Chain<0>, Chain<9>>)->Name("Chain fail, 4 levels");88BENCHMARK(DynCast<Chain<5>, Chain<0>, Chain<9>>)->Name("Chain fail, 5 levels");89BENCHMARK(DynCast<Chain<6>, Chain<0>, Chain<9>>)->Name("Chain fail, 6 levels");90BENCHMARK(DynCast<Chain<7>, Chain<0>, Chain<9>>)->Name("Chain fail, 7 levels");91BENCHMARK(DynCast<Chain<8>, Chain<0>, Chain<9>>)->Name("Chain fail, 8 levels");92 93// Downcast along a virtual inheritance chain from base to the most derived type94BENCHMARK(DynCast<VChain<1>, VChain<0>>)->Name("VChain, 1 level");95BENCHMARK(DynCast<VChain<2>, VChain<0>>)->Name("VChain, 2 levels");96BENCHMARK(DynCast<VChain<3>, VChain<0>>)->Name("VChain, 3 levels");97BENCHMARK(DynCast<VChain<4>, VChain<0>>)->Name("VChain, 4 levels");98BENCHMARK(DynCast<VChain<5>, VChain<0>>)->Name("VChain, 5 levels");99 100// Downcast along a virtual inheritance chain from base to the middle of the chain101BENCHMARK(DynCast<VChain<2>, VChain<0>, VChain<1>>)->Name("VChain middle, 1 level");102BENCHMARK(DynCast<VChain<4>, VChain<0>, VChain<2>>)->Name("VChain middle, 2 levels");103BENCHMARK(DynCast<VChain<6>, VChain<0>, VChain<3>>)->Name("VChain middle, 3 levels");104BENCHMARK(DynCast<VChain<8>, VChain<0>, VChain<4>>)->Name("VChain middle, 4 levels");105 106// Downcast along a virtual chain that fails107BENCHMARK(DynCast<VChain<1>, VChain<0>, VChain<8>>)->Name("VChain fail, 1 level");108BENCHMARK(DynCast<VChain<2>, VChain<0>, VChain<8>>)->Name("VChain fail, 2 levels");109BENCHMARK(DynCast<VChain<3>, VChain<0>, VChain<8>>)->Name("VChain fail, 3 levels");110BENCHMARK(DynCast<VChain<4>, VChain<0>, VChain<8>>)->Name("VChain fail, 4 levels");111BENCHMARK(DynCast<VChain<5>, VChain<0>, VChain<8>>)->Name("VChain fail, 5 levels");112 113// Downcast along a DAG from base to the most derived type114BENCHMARK(DynCast<Dag<0, 3>, Dag<3, 0>>)->Name("DAG rightmost, 3 levels");115BENCHMARK(DynCast<Dag<0, 4>, Dag<4, 0>>)->Name("DAG rightmost, 4 levels");116BENCHMARK(DynCast<Dag<0, 5>, Dag<5, 0>>)->Name("DAG rightmost, 5 levels");117BENCHMARK(DynCast<Dag<0, 3>, Dag<0, 0>>)->Name("DAG leftmost, 3 levels");118BENCHMARK(DynCast<Dag<0, 4>, Dag<0, 0>>)->Name("DAG leftmost, 4 levels");119BENCHMARK(DynCast<Dag<0, 5>, Dag<0, 0>>)->Name("DAG leftmost, 5 levels");120 121// Downcast along a DAG from base to the middle of the DAG122BENCHMARK(DynCast<Dag<0, 4>, Dag<4, 0>, Dag<3, 1>>)->Name("DAG rightmost middle, 1 level");123BENCHMARK(DynCast<Dag<0, 4>, Dag<4, 0>, Dag<2, 2>>)->Name("DAG rightmost middle, 2 levels");124BENCHMARK(DynCast<Dag<0, 4>, Dag<4, 0>, Dag<1, 3>>)->Name("DAG rightmost middle, 3 levels");125BENCHMARK(DynCast<Dag<0, 4>, Dag<0, 0>, Dag<0, 1>>)->Name("DAG leftmost middle, 1 level");126BENCHMARK(DynCast<Dag<0, 4>, Dag<0, 0>, Dag<0, 2>>)->Name("DAG leftmost middle, 2 levels");127BENCHMARK(DynCast<Dag<0, 4>, Dag<0, 0>, Dag<0, 3>>)->Name("DAG leftmost middle, 3 levels");128 129// Sidecast along a DAG130BENCHMARK(DynCast<Dag<0, 3>, Dag<3, 0>, Dag<0, 0>>)->Name("DAG sidecast, 3 levels");131BENCHMARK(DynCast<Dag<0, 3>, Dag<2, 1>, Dag<0, 1>>)->Name("DAG sidecast, 2 levels");132BENCHMARK(DynCast<Dag<0, 3>, Dag<1, 2>, Dag<0, 2>>)->Name("DAG sidecast, 1 level");133 134// Sidecast along a DAG that fails135BENCHMARK(DynCast<Dag<0, 3>, Dag<3, 0>, Dag<0, 4>>)->Name("DAG sidecast fail, 3 levels");136BENCHMARK(DynCast<Dag<0, 3>, Dag<2, 1>, Dag<0, 4>>)->Name("DAG sidecast fail, 2 levels");137BENCHMARK(DynCast<Dag<0, 3>, Dag<1, 2>, Dag<0, 4>>)->Name("DAG sidecast fail, 1 level");138 139// Downcast along a virtual inheritance DAG from base to the most derived type140BENCHMARK(DynCast<VDag<0, 3>, VDag<3, 0>>)->Name("VDAG rightmost, 3 levels");141BENCHMARK(DynCast<VDag<0, 4>, VDag<4, 0>>)->Name("VDAG rightmost, 4 levels");142BENCHMARK(DynCast<VDag<0, 5>, VDag<5, 0>>)->Name("VDAG rightmost, 5 levels");143BENCHMARK(DynCast<VDag<0, 3>, VDag<0, 0>>)->Name("VDAG leftmost, 3 levels");144BENCHMARK(DynCast<VDag<0, 4>, VDag<0, 0>>)->Name("VDAG leftmost, 4 levels");145BENCHMARK(DynCast<VDag<0, 5>, VDag<0, 0>>)->Name("VDAG leftmost, 5 levels");146 147// Downcast along a virtual inheritance DAG from base to the middle of the DAG148BENCHMARK(DynCast<VDag<0, 3>, VDag<3, 0>, VDag<2, 1>>)->Name("VDAG rightmost middle, 1 level");149BENCHMARK(DynCast<VDag<0, 4>, VDag<4, 0>, VDag<2, 2>>)->Name("VDAG rightmost middle, 2 levels");150BENCHMARK(DynCast<VDag<0, 5>, VDag<5, 0>, VDag<2, 3>>)->Name("VDAG rightmost middle, 3 levels");151BENCHMARK(DynCast<VDag<0, 3>, VDag<0, 0>, VDag<0, 1>>)->Name("VDAG leftmost middle, 1 level");152BENCHMARK(DynCast<VDag<0, 4>, VDag<0, 0>, VDag<0, 2>>)->Name("VDAG leftmost middle, 2 levels");153BENCHMARK(DynCast<VDag<0, 5>, VDag<0, 0>, VDag<0, 3>>)->Name("VDAG leftmost middle, 3 levels");154 155// Sidecast along a virtual inheritance DAG156BENCHMARK(DynCast<VDag<0, 3>, VDag<3, 0>, VDag<0, 0>>)->Name("VDAG sidecast, 3 levels");157BENCHMARK(DynCast<VDag<0, 3>, VDag<2, 1>, VDag<0, 1>>)->Name("VDAG sidecast, 2 levels");158BENCHMARK(DynCast<VDag<0, 3>, VDag<1, 2>, VDag<0, 2>>)->Name("VDAG sidecast, 1 level");159 160// Sidecast along a virtual inheritance DAG that fails161BENCHMARK(DynCast<VDag<0, 3>, VDag<3, 0>, VDag<0, 4>>)->Name("VDAG sidecast fail, 3 levels");162BENCHMARK(DynCast<VDag<0, 3>, VDag<2, 1>, VDag<0, 4>>)->Name("VDAG sidecast fail, 2 levels");163BENCHMARK(DynCast<VDag<0, 3>, VDag<1, 2>, VDag<0, 4>>)->Name("VDAG sidecast fail, 1 level");164 165// Cast to complete object pointer166BENCHMARK(DynCast<Chain<8>, Chain<0>, void>)->Name("Chain to complete");167BENCHMARK(DynCast<VChain<5>, VChain<0>, void>)->Name("VChain to complete");168BENCHMARK(DynCast<Dag<0, 3>, Dag<3, 0>, void>)->Name("DAG to complete");169BENCHMARK(DynCast<VDag<0, 3>, VDag<3, 0>, void>)->Name("VDAG to complete");170 171// Static cast as the baseline.172BENCHMARK(StaticCast)->Name("Static");173 174BENCHMARK_MAIN();175