From e4c8d0eb8ef4acb5d7a4252b3b87feb391ef7e41 Mon Sep 17 00:00:00 2001 From: Abseil Team Date: Fri, 18 Oct 2019 09:06:29 -0700 Subject: Export of internal Abseil changes -- a9ac6567c0933d786d68c10011e3f3ff9deedf89 by Greg Falcon : Add absl::FunctionRef, a type analogous to the proposed C++23 std::function_ref. Like std::function, FunctionRef can be used to type-erase any callable (invokable) object. However, FunctionRef works by reference: it does not store a copy of the type-erased object. If the wrapped object is destroyed before the FunctionRef, the reference becomes dangling. FunctionRef relates to std::function in much the same way that string_view relates to std::string. Because of these limitations, FunctionRef is best used only as a function argument type, and only where the function will be invoked immediately (rather than saved for later use). When `const std::function<...>&` is used in this way, `absl::FunctionRef<...>` is a better-performing replacement. PiperOrigin-RevId: 275484044 -- 1f7c4df3760f8b93e5a5baf40b070eca1d3f4c98 by Abseil Team : Add FastHexToBufferZeroPad16() function for blazingly fast hex encoding of uint64_t. PiperOrigin-RevId: 275420901 -- 08d48ac004eba57cf2f1ada827181a2995f74807 by Abseil Team : Avoid applying the workaround for MSVC's static initialization problems when using clang-cl. PiperOrigin-RevId: 275366326 -- 40be82bd2b34670b5458c0a72a0475086153c2d6 by Abseil Team : Added comments to SimpleAtof()/SimpleAtod() that clarify that they always use the "C" locale, unlike the standard functions strtod() and strtof() referenced now in the comments. PiperOrigin-RevId: 275355815 -- 086779dacb3f6f2b3ab59947e94e79046bdb1fe1 by Jorg Brown : Move the hex conversion table used by escaping.cc into numbers.h so that other parts of Abseil can more efficiently access it. PiperOrigin-RevId: 275331251 -- 3c4ed1b04e55d96a40cbe70fb70929ffbb0c0432 by Abseil Team : Avoid applying the workaround for MSVC's static initialization problems when using clang-cl. PiperOrigin-RevId: 275323858 -- 56ceb58ab688c3761978308609b09a1ac2739c9a by Derek Mauro : Add script for testing on Alpine Linux (for musl test coverage) PiperOrigin-RevId: 275321244 GitOrigin-RevId: a9ac6567c0933d786d68c10011e3f3ff9deedf89 Change-Id: I39799fa03768ddb44f3166200c860e1da4461807 --- absl/functional/function_ref_benchmark.cc | 140 ++++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) create mode 100644 absl/functional/function_ref_benchmark.cc (limited to 'absl/functional/function_ref_benchmark.cc') diff --git a/absl/functional/function_ref_benchmark.cc b/absl/functional/function_ref_benchmark.cc new file mode 100644 index 0000000..f6dfcab --- /dev/null +++ b/absl/functional/function_ref_benchmark.cc @@ -0,0 +1,140 @@ +// Copyright 2019 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "absl/functional/function_ref.h" + +#include + +#include "benchmark/benchmark.h" +#include "absl/base/attributes.h" + +namespace absl { +namespace { + +int dummy = 0; + +void FreeFunction() { benchmark::DoNotOptimize(dummy); } + +struct TrivialFunctor { + void operator()() const { benchmark::DoNotOptimize(dummy); } +}; + +struct LargeFunctor { + void operator()() const { benchmark::DoNotOptimize(this); } + std::string a, b, c; +}; + +template +void ABSL_ATTRIBUTE_NOINLINE CallFunction(Function f, Args&&... args) { + f(std::forward(args)...); +} + +template +void ConstructAndCallFunctionBenchmark(benchmark::State& state, + const Callable& c, Args&&... args) { + for (auto _ : state) { + CallFunction(c, std::forward(args)...); + } +} + +void BM_TrivialStdFunction(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, + TrivialFunctor{}); +} +BENCHMARK(BM_TrivialStdFunction); + +void BM_TrivialFunctionRef(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, + TrivialFunctor{}); +} +BENCHMARK(BM_TrivialFunctionRef); + +void BM_LargeStdFunction(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, + LargeFunctor{}); +} +BENCHMARK(BM_LargeStdFunction); + +void BM_LargeFunctionRef(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, LargeFunctor{}); +} +BENCHMARK(BM_LargeFunctionRef); + +void BM_FunPtrStdFunction(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, FreeFunction); +} +BENCHMARK(BM_FunPtrStdFunction); + +void BM_FunPtrFunctionRef(benchmark::State& state) { + ConstructAndCallFunctionBenchmark>(state, FreeFunction); +} +BENCHMARK(BM_FunPtrFunctionRef); + +// Doesn't include construction or copy overhead in the loop. +template +void CallFunctionBenchmark(benchmark::State& state, const Callable& c, + Args... args) { + Function f = c; + for (auto _ : state) { + benchmark::DoNotOptimize(&f); + f(args...); + } +} + +struct FunctorWithTrivialArgs { + void operator()(int a, int b, int c) const { + benchmark::DoNotOptimize(a); + benchmark::DoNotOptimize(b); + benchmark::DoNotOptimize(c); + } +}; + +void BM_TrivialArgsStdFunction(benchmark::State& state) { + CallFunctionBenchmark>( + state, FunctorWithTrivialArgs{}, 1, 2, 3); +} +BENCHMARK(BM_TrivialArgsStdFunction); + +void BM_TrivialArgsFunctionRef(benchmark::State& state) { + CallFunctionBenchmark>( + state, FunctorWithTrivialArgs{}, 1, 2, 3); +} +BENCHMARK(BM_TrivialArgsFunctionRef); + +struct FunctorWithNonTrivialArgs { + void operator()(std::string a, std::string b, std::string c) const { + benchmark::DoNotOptimize(&a); + benchmark::DoNotOptimize(&b); + benchmark::DoNotOptimize(&c); + } +}; + +void BM_NonTrivialArgsStdFunction(benchmark::State& state) { + std::string a, b, c; + CallFunctionBenchmark< + std::function>( + state, FunctorWithNonTrivialArgs{}, a, b, c); +} +BENCHMARK(BM_NonTrivialArgsStdFunction); + +void BM_NonTrivialArgsFunctionRef(benchmark::State& state) { + std::string a, b, c; + CallFunctionBenchmark< + FunctionRef>( + state, FunctorWithNonTrivialArgs{}, a, b, c); +} +BENCHMARK(BM_NonTrivialArgsFunctionRef); + +} // namespace +} // namespace absl -- cgit v1.2.3