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-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9
10 #include <string>
11 #include <tuple>
12 #include <type_traits>
13 #include <vector>
14
15 #include "benchmark/benchmark.h"
16 #include "test_macros.h"
17
18 namespace internal {
19
20 template <class D, class E, size_t I>
21 struct EnumValue : std::integral_constant<E, static_cast<E>(I)> {
nameEnumValue22 static std::string name() { return std::string("_") + D::Names[I]; }
23 };
24
25 template <class D, class E, size_t ...Idxs>
makeEnumValueTuple(std::index_sequence<Idxs...>)26 constexpr auto makeEnumValueTuple(std::index_sequence<Idxs...>) {
27 return std::make_tuple(EnumValue<D, E, Idxs>{}...);
28 }
29
30 template <class B>
31 static auto skip(const B& Bench, int) -> decltype(Bench.skip()) {
32 return Bench.skip();
33 }
34 template <class B>
skip(const B & Bench,char)35 static auto skip(const B& Bench, char) {
36 return false;
37 }
38
39 template <class B, class Args, size_t... Is>
makeBenchmarkFromValuesImpl(const Args & A,std::index_sequence<Is...>)40 void makeBenchmarkFromValuesImpl(const Args& A, std::index_sequence<Is...>) {
41 for (auto& V : A) {
42 B Bench{std::get<Is>(V)...};
43 if (!internal::skip(Bench, 0)) {
44 benchmark::RegisterBenchmark(Bench.name().c_str(),
45 [=](benchmark::State& S) { Bench.run(S); });
46 }
47 }
48 }
49
50 template <class B, class... Args>
makeBenchmarkFromValues(const std::vector<std::tuple<Args...>> & A)51 void makeBenchmarkFromValues(const std::vector<std::tuple<Args...> >& A) {
52 makeBenchmarkFromValuesImpl<B>(A, std::index_sequence_for<Args...>());
53 }
54
55 template <template <class...> class B, class Args, class... U>
makeBenchmarkImpl(const Args & A,std::tuple<U...> t)56 void makeBenchmarkImpl(const Args& A, std::tuple<U...> t) {
57 makeBenchmarkFromValues<B<U...> >(A);
58 }
59
60 template <template <class...> class B, class Args, class... U,
61 class... T, class... Tuples>
makeBenchmarkImpl(const Args & A,std::tuple<U...>,std::tuple<T...>,Tuples...rest)62 void makeBenchmarkImpl(const Args& A, std::tuple<U...>, std::tuple<T...>,
63 Tuples... rest) {
64 (internal::makeBenchmarkImpl<B>(A, std::tuple<U..., T>(), rest...), ...);
65 }
66
67 template <class R, class T>
allValueCombinations(R & Result,const T & Final)68 void allValueCombinations(R& Result, const T& Final) {
69 return Result.push_back(Final);
70 }
71
72 template <class R, class T, class V, class... Vs>
allValueCombinations(R & Result,const T & Prev,const V & Value,const Vs &...Values)73 void allValueCombinations(R& Result, const T& Prev, const V& Value,
74 const Vs&... Values) {
75 for (const auto& E : Value) {
76 allValueCombinations(Result, std::tuple_cat(Prev, std::make_tuple(E)),
77 Values...);
78 }
79 }
80
81 } // namespace internal
82
83 // CRTP class that enables using enum types as a dimension for
84 // makeCartesianProductBenchmark below.
85 // The type passed to `B` will be a std::integral_constant<E, e>, with the
86 // additional static function `name()` that returns the stringified name of the
87 // label.
88 //
89 // Eg:
90 // enum class MyEnum { A, B };
91 // struct AllMyEnum : EnumValuesAsTuple<AllMyEnum, MyEnum, 2> {
92 // static constexpr absl::string_view Names[] = {"A", "B"};
93 // };
94 template <class Derived, class EnumType, size_t NumLabels>
95 using EnumValuesAsTuple =
96 decltype(internal::makeEnumValueTuple<Derived, EnumType>(
97 std::make_index_sequence<NumLabels>{}));
98
99 // Instantiates B<T0, T1, ..., TN> where <Ti...> are the combinations in the
100 // cartesian product of `Tuples...`, and pass (arg0, ..., argN) as constructor
101 // arguments where `(argi...)` are the combination in the cartesian product of
102 // the runtime values of `A...`.
103 // B<T...> requires:
104 // - std::string name(args...): The name of the benchmark.
105 // - void run(benchmark::State&, args...): The body of the benchmark.
106 // It can also optionally provide:
107 // - bool skip(args...): When `true`, skips the combination. Default is false.
108 //
109 // Returns int to facilitate registration. The return value is unspecified.
110 template <template <class...> class B, class... Tuples, class... Args>
makeCartesianProductBenchmark(const Args &...A)111 int makeCartesianProductBenchmark(const Args&... A) {
112 std::vector<std::tuple<typename Args::value_type...> > V;
113 internal::allValueCombinations(V, std::tuple<>(), A...);
114 internal::makeBenchmarkImpl<B>(V, std::tuple<>(), Tuples()...);
115 return 0;
116 }
117
118 template <class B, class... Args>
makeCartesianProductBenchmark(const Args &...A)119 int makeCartesianProductBenchmark(const Args&... A) {
120 std::vector<std::tuple<typename Args::value_type...> > V;
121 internal::allValueCombinations(V, std::tuple<>(), A...);
122 internal::makeBenchmarkFromValues<B>(V);
123 return 0;
124 }
125
126 // When `opaque` is true, this function hides the runtime state of `value` from
127 // the optimizer.
128 // It returns `value`.
129 template <class T>
maybeOpaque(T value,bool opaque)130 TEST_ALWAYS_INLINE inline T maybeOpaque(T value, bool opaque) {
131 if (opaque) benchmark::DoNotOptimize(value);
132 return value;
133 }
134