summaryrefslogtreecommitdiff
path: root/absl/strings/numbers_benchmark.cc
blob: 54dbedd35357772d786d121d85cda71a16831b0b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
// Copyright 2018 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 <cstdint>
#include <random>
#include <string>
#include <type_traits>
#include <vector>

#include "benchmark/benchmark.h"
#include "absl/base/internal/raw_logging.h"
#include "absl/strings/numbers.h"

namespace {

template <typename T>
void BM_FastIntToBuffer(benchmark::State& state) {
  const int inc = state.range(0);
  char buf[absl::numbers_internal::kFastToBufferSize];
  // Use the unsigned type to increment to take advantage of well-defined
  // modular arithmetic.
  typename std::make_unsigned<T>::type x = 0;
  for (auto _ : state) {
    absl::numbers_internal::FastIntToBuffer(static_cast<T>(x), buf);
    x += inc;
  }
}
BENCHMARK_TEMPLATE(BM_FastIntToBuffer, int32_t)->Range(0, 1 << 15);
BENCHMARK_TEMPLATE(BM_FastIntToBuffer, int64_t)->Range(0, 1 << 30);

// Creates an integer that would be printed as `num_digits` repeated 7s in the
// given `base`. `base` must be greater than or equal to 8.
int64_t RepeatedSevens(int num_digits, int base) {
  ABSL_RAW_CHECK(base >= 8, "");
  int64_t num = 7;
  while (--num_digits) num = base * num + 7;
  return num;
}

void BM_safe_strto32_string(benchmark::State& state) {
  const int digits = state.range(0);
  const int base = state.range(1);
  std::string str(digits, '7');  // valid in octal, decimal and hex
  int32_t value = 0;
  for (auto _ : state) {
    benchmark::DoNotOptimize(
        absl::numbers_internal::safe_strto32_base(str, &value, base));
  }
  ABSL_RAW_CHECK(value == RepeatedSevens(digits, base), "");
}
BENCHMARK(BM_safe_strto32_string)
    ->ArgPair(1, 8)
    ->ArgPair(1, 10)
    ->ArgPair(1, 16)
    ->ArgPair(2, 8)
    ->ArgPair(2, 10)
    ->ArgPair(2, 16)
    ->ArgPair(4, 8)
    ->ArgPair(4, 10)
    ->ArgPair(4, 16)
    ->ArgPair(8, 8)
    ->ArgPair(8, 10)
    ->ArgPair(8, 16)
    ->ArgPair(10, 8)
    ->ArgPair(9, 10);

void BM_safe_strto64_string(benchmark::State& state) {
  const int digits = state.range(0);
  const int base = state.range(1);
  std::string str(digits, '7');  // valid in octal, decimal and hex
  int64_t value = 0;
  for (auto _ : state) {
    benchmark::DoNotOptimize(
        absl::numbers_internal::safe_strto64_base(str, &value, base));
  }
  ABSL_RAW_CHECK(value == RepeatedSevens(digits, base), "");
}
BENCHMARK(BM_safe_strto64_string)
    ->ArgPair(1, 8)
    ->ArgPair(1, 10)
    ->ArgPair(1, 16)
    ->ArgPair(2, 8)
    ->ArgPair(2, 10)
    ->ArgPair(2, 16)
    ->ArgPair(4, 8)
    ->ArgPair(4, 10)
    ->ArgPair(4, 16)
    ->ArgPair(8, 8)
    ->ArgPair(8, 10)
    ->ArgPair(8, 16)
    ->ArgPair(16, 8)
    ->ArgPair(16, 10)
    ->ArgPair(16, 16);

void BM_safe_strtou32_string(benchmark::State& state) {
  const int digits = state.range(0);
  const int base = state.range(1);
  std::string str(digits, '7');  // valid in octal, decimal and hex
  uint32_t value = 0;
  for (auto _ : state) {
    benchmark::DoNotOptimize(
        absl::numbers_internal::safe_strtou32_base(str, &value, base));
  }
  ABSL_RAW_CHECK(value == RepeatedSevens(digits, base), "");
}
BENCHMARK(BM_safe_strtou32_string)
    ->ArgPair(1, 8)
    ->ArgPair(1, 10)
    ->ArgPair(1, 16)
    ->ArgPair(2, 8)
    ->ArgPair(2, 10)
    ->ArgPair(2, 16)
    ->ArgPair(4, 8)
    ->ArgPair(4, 10)
    ->ArgPair(4, 16)
    ->ArgPair(8, 8)
    ->ArgPair(8, 10)
    ->ArgPair(8, 16)
    ->ArgPair(10, 8)
    ->ArgPair(9, 10);

void BM_safe_strtou64_string(benchmark::State& state) {
  const int digits = state.range(0);
  const int base = state.range(1);
  std::string str(digits, '7');  // valid in octal, decimal and hex
  uint64_t value = 0;
  for (auto _ : state) {
    benchmark::DoNotOptimize(
        absl::numbers_internal::safe_strtou64_base(str, &value, base));
  }
  ABSL_RAW_CHECK(value == RepeatedSevens(digits, base), "");
}
BENCHMARK(BM_safe_strtou64_string)
    ->ArgPair(1, 8)
    ->ArgPair(1, 10)
    ->ArgPair(1, 16)
    ->ArgPair(2, 8)
    ->ArgPair(2, 10)
    ->ArgPair(2, 16)
    ->ArgPair(4, 8)
    ->ArgPair(4, 10)
    ->ArgPair(4, 16)
    ->ArgPair(8, 8)
    ->ArgPair(8, 10)
    ->ArgPair(8, 16)
    ->ArgPair(16, 8)
    ->ArgPair(16, 10)
    ->ArgPair(16, 16);

// Returns a vector of `num_strings` strings. Each string represents a
// floating point number with `num_digits` digits before the decimal point and
// another `num_digits` digits after.
std::vector<std::string> MakeFloatStrings(int num_strings, int num_digits) {
  // For convenience, use a random number generator to generate the test data.
  // We don't actually need random properties, so use a fixed seed.
  std::minstd_rand0 rng(1);
  std::uniform_int_distribution<int> random_digit('0', '9');

  std::vector<std::string> float_strings(num_strings);
  for (std::string& s : float_strings) {
    s.reserve(2 * num_digits + 1);
    for (int i = 0; i < num_digits; ++i) {
      s.push_back(static_cast<char>(random_digit(rng)));
    }
    s.push_back('.');
    for (int i = 0; i < num_digits; ++i) {
      s.push_back(static_cast<char>(random_digit(rng)));
    }
  }
  return float_strings;
}

template <typename StringType>
StringType GetStringAs(const std::string& s) {
  return static_cast<StringType>(s);
}
template <>
const char* GetStringAs<const char*>(const std::string& s) {
  return s.c_str();
}

template <typename StringType>
std::vector<StringType> GetStringsAs(const std::vector<std::string>& strings) {
  std::vector<StringType> result;
  result.reserve(strings.size());
  for (const std::string& s : strings) {
    result.push_back(GetStringAs<StringType>(s));
  }
  return result;
}

template <typename T>
void BM_SimpleAtof(benchmark::State& state) {
  const int num_strings = state.range(0);
  const int num_digits = state.range(1);
  std::vector<std::string> backing_strings =
      MakeFloatStrings(num_strings, num_digits);
  std::vector<T> inputs = GetStringsAs<T>(backing_strings);
  float value;
  for (auto _ : state) {
    for (const T& input : inputs) {
      benchmark::DoNotOptimize(absl::SimpleAtof(input, &value));
    }
  }
}
BENCHMARK_TEMPLATE(BM_SimpleAtof, absl::string_view)
    ->ArgPair(10, 1)
    ->ArgPair(10, 2)
    ->ArgPair(10, 4)
    ->ArgPair(10, 8);
BENCHMARK_TEMPLATE(BM_SimpleAtof, const char*)
    ->ArgPair(10, 1)
    ->ArgPair(10, 2)
    ->ArgPair(10, 4)
    ->ArgPair(10, 8);
BENCHMARK_TEMPLATE(BM_SimpleAtof, std::string)
    ->ArgPair(10, 1)
    ->ArgPair(10, 2)
    ->ArgPair(10, 4)
    ->ArgPair(10, 8);

template <typename T>
void BM_SimpleAtod(benchmark::State& state) {
  const int num_strings = state.range(0);
  const int num_digits = state.range(1);
  std::vector<std::string> backing_strings =
      MakeFloatStrings(num_strings, num_digits);
  std::vector<T> inputs = GetStringsAs<T>(backing_strings);
  double value;
  for (auto _ : state) {
    for (const T& input : inputs) {
      benchmark::DoNotOptimize(absl::SimpleAtod(input, &value));
    }
  }
}
BENCHMARK_TEMPLATE(BM_SimpleAtod, absl::string_view)
    ->ArgPair(10, 1)
    ->ArgPair(10, 2)
    ->ArgPair(10, 4)
    ->ArgPair(10, 8);
BENCHMARK_TEMPLATE(BM_SimpleAtod, const char*)
    ->ArgPair(10, 1)
    ->ArgPair(10, 2)
    ->ArgPair(10, 4)
    ->ArgPair(10, 8);
BENCHMARK_TEMPLATE(BM_SimpleAtod, std::string)
    ->ArgPair(10, 1)
    ->ArgPair(10, 2)
    ->ArgPair(10, 4)
    ->ArgPair(10, 8);

}  // namespace