lokinet/vendor/abseil-cpp/absl/strings/internal/char_map_benchmark.cc
2019-02-03 01:56:38 +00:00

62 lines
2.0 KiB
C++

// Copyright 2017 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
//
// http://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/strings/internal/char_map.h"
#include <cstdint>
#include "benchmark/benchmark.h"
namespace {
absl::strings_internal::Charmap MakeBenchmarkMap() {
absl::strings_internal::Charmap m;
uint32_t x[] = {0x0, 0x1, 0x2, 0x3, 0xf, 0xe, 0xd, 0xc};
for (uint32_t& t : x) t *= static_cast<uint32_t>(0x11111111UL);
for (uint32_t i = 0; i < 256; ++i) {
if ((x[i / 32] >> (i % 32)) & 1)
m = m | absl::strings_internal::Charmap::Char(i);
}
return m;
}
// Micro-benchmark for Charmap::contains.
void BM_Contains(benchmark::State& state) {
// Loop-body replicated 10 times to increase time per iteration.
// Argument continuously changed to avoid generating common subexpressions.
const absl::strings_internal::Charmap benchmark_map = MakeBenchmarkMap();
unsigned char c = 0;
int ops = 0;
for (auto _ : state) {
ops += benchmark_map.contains(c++);
ops += benchmark_map.contains(c++);
ops += benchmark_map.contains(c++);
ops += benchmark_map.contains(c++);
ops += benchmark_map.contains(c++);
ops += benchmark_map.contains(c++);
ops += benchmark_map.contains(c++);
ops += benchmark_map.contains(c++);
ops += benchmark_map.contains(c++);
ops += benchmark_map.contains(c++);
}
benchmark::DoNotOptimize(ops);
}
BENCHMARK(BM_Contains);
// We don't bother benchmarking Charmap::IsZero or Charmap::IntersectsWith;
// their running time is data-dependent and it is not worth characterizing
// "typical" data.
} // namespace