str_cat_benchmark.cc
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1 // Copyright 2018 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 
15 #include "absl/strings/str_cat.h"
16 
17 #include <cstdint>
18 #include <string>
19 
20 #include "benchmark/benchmark.h"
22 
23 namespace {
24 
25 const char kStringOne[] = "Once Upon A Time, ";
26 const char kStringTwo[] = "There was a std::string benchmark";
27 
28 // We want to include negative numbers in the benchmark, so this function
29 // is used to count 0, 1, -1, 2, -2, 3, -3, ...
30 inline int IncrementAlternatingSign(int i) {
31  return i > 0 ? -i : 1 - i;
32 }
33 
34 void BM_Sum_By_StrCat(benchmark::State& state) {
35  int i = 0;
36  char foo[100];
37  for (auto _ : state) {
38  // NOLINTNEXTLINE(runtime/printf)
39  strcpy(foo, absl::StrCat(kStringOne, i, kStringTwo, i * 65536ULL).c_str());
40  int sum = 0;
41  for (char* f = &foo[0]; *f != 0; ++f) {
42  sum += *f;
43  }
44  benchmark::DoNotOptimize(sum);
45  i = IncrementAlternatingSign(i);
46  }
47 }
48 BENCHMARK(BM_Sum_By_StrCat);
49 
50 void BM_StrCat_By_snprintf(benchmark::State& state) {
51  int i = 0;
52  char on_stack[1000];
53  for (auto _ : state) {
54  snprintf(on_stack, sizeof(on_stack), "%s %s:%d", kStringOne, kStringTwo, i);
55  i = IncrementAlternatingSign(i);
56  }
57 }
58 BENCHMARK(BM_StrCat_By_snprintf);
59 
60 void BM_StrCat_By_Strings(benchmark::State& state) {
61  int i = 0;
62  for (auto _ : state) {
63  std::string result =
64  std::string(kStringOne) + " " + kStringTwo + ":" + absl::StrCat(i);
65  benchmark::DoNotOptimize(result);
66  i = IncrementAlternatingSign(i);
67  }
68 }
69 BENCHMARK(BM_StrCat_By_Strings);
70 
71 void BM_StrCat_By_StringOpPlus(benchmark::State& state) {
72  int i = 0;
73  for (auto _ : state) {
74  std::string result = kStringOne;
75  result += " ";
76  result += kStringTwo;
77  result += ":";
78  result += absl::StrCat(i);
79  benchmark::DoNotOptimize(result);
80  i = IncrementAlternatingSign(i);
81  }
82 }
83 BENCHMARK(BM_StrCat_By_StringOpPlus);
84 
85 void BM_StrCat_By_StrCat(benchmark::State& state) {
86  int i = 0;
87  for (auto _ : state) {
88  std::string result = absl::StrCat(kStringOne, " ", kStringTwo, ":", i);
89  benchmark::DoNotOptimize(result);
90  i = IncrementAlternatingSign(i);
91  }
92 }
93 BENCHMARK(BM_StrCat_By_StrCat);
94 
95 void BM_HexCat_By_StrCat(benchmark::State& state) {
96  int i = 0;
97  for (auto _ : state) {
98  std::string result =
99  absl::StrCat(kStringOne, " ", absl::Hex(int64_t{i} + 0x10000000));
100  benchmark::DoNotOptimize(result);
101  i = IncrementAlternatingSign(i);
102  }
103 }
104 BENCHMARK(BM_HexCat_By_StrCat);
105 
106 void BM_HexCat_By_Substitute(benchmark::State& state) {
107  int i = 0;
108  for (auto _ : state) {
109  std::string result = absl::Substitute(
110  "$0 $1", kStringOne, reinterpret_cast<void*>(int64_t{i} + 0x10000000));
111  benchmark::DoNotOptimize(result);
112  i = IncrementAlternatingSign(i);
113  }
114 }
115 BENCHMARK(BM_HexCat_By_Substitute);
116 
117 void BM_FloatToString_By_StrCat(benchmark::State& state) {
118  int i = 0;
119  float foo = 0.0f;
120  for (auto _ : state) {
121  std::string result = absl::StrCat(foo += 1.001f, " != ", int64_t{i});
122  benchmark::DoNotOptimize(result);
123  i = IncrementAlternatingSign(i);
124  }
125 }
126 BENCHMARK(BM_FloatToString_By_StrCat);
127 
128 void BM_DoubleToString_By_SixDigits(benchmark::State& state) {
129  int i = 0;
130  double foo = 0.0;
131  for (auto _ : state) {
132  std::string result =
133  absl::StrCat(absl::SixDigits(foo += 1.001), " != ", int64_t{i});
134  benchmark::DoNotOptimize(result);
135  i = IncrementAlternatingSign(i);
136  }
137 }
138 BENCHMARK(BM_DoubleToString_By_SixDigits);
139 
140 } // namespace
std::string StrCat(const AlphaNum &a, const AlphaNum &b)
Definition: str_cat.cc:98
strings_internal::AlphaNumBuffer< numbers_internal::kSixDigitsToBufferSize > SixDigits(double d)
Definition: str_cat.h:395
int foo
ABSL_MUST_USE_RESULT std::string Substitute(absl::string_view format)
Definition: substitute.h:473


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autogenerated on Wed Jun 19 2019 19:19:58