char_map_benchmark.cc
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1 // Copyright 2017 The Abseil Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
16 
17 #include <cstdint>
18 
19 #include "benchmark/benchmark.h"
20 
21 namespace {
22 
23 absl::strings_internal::Charmap MakeBenchmarkMap() {
25  uint32_t x[] = {0x0, 0x1, 0x2, 0x3, 0xf, 0xe, 0xd, 0xc};
26  for (uint32_t& t : x) t *= static_cast<uint32_t>(0x11111111UL);
27  for (uint32_t i = 0; i < 256; ++i) {
28  if ((x[i / 32] >> (i % 32)) & 1)
30  }
31  return m;
32 }
33 
34 // Micro-benchmark for Charmap::contains.
35 void BM_Contains(benchmark::State& state) {
36  // Loop-body replicated 10 times to increase time per iteration.
37  // Argument continuously changed to avoid generating common subexpressions.
38  const absl::strings_internal::Charmap benchmark_map = MakeBenchmarkMap();
39  unsigned char c = 0;
40  int ops = 0;
41  for (auto _ : state) {
42  ops += benchmark_map.contains(c++);
43  ops += benchmark_map.contains(c++);
44  ops += benchmark_map.contains(c++);
45  ops += benchmark_map.contains(c++);
46  ops += benchmark_map.contains(c++);
47  ops += benchmark_map.contains(c++);
48  ops += benchmark_map.contains(c++);
49  ops += benchmark_map.contains(c++);
50  ops += benchmark_map.contains(c++);
51  ops += benchmark_map.contains(c++);
52  }
53  benchmark::DoNotOptimize(ops);
54 }
55 BENCHMARK(BM_Contains);
56 
57 // We don't bother benchmarking Charmap::IsZero or Charmap::IntersectsWith;
58 // their running time is data-dependent and it is not worth characterizing
59 // "typical" data.
60 
61 } // namespace
static constexpr Charmap Char(char x)
Definition: char_map.h:69
constexpr bool contains(unsigned char c) const
Definition: char_map.h:49


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autogenerated on Mon Feb 28 2022 21:31:17