1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03, c++11, c++14
10
11#include "benchmark/benchmark.h"
12#include "test_macros.h"
13
14#include <mutex>
15#include <sstream>
16
17TEST_NOINLINE double istream_numbers();
18
19double istream_numbers(std::locale* loc) {
20 const char* a[] = {"-6 69 -71 2.4882e-02 -100 101 -2.00005 5000000 -50000000",
21 "-25 71 7 -9.3262e+01 -100 101 -2.00005 5000000 -50000000",
22 "-14 53 46 -6.7026e-02 -100 101 -2.00005 5000000 -50000000"};
23
24 int a1, a2, a3, a4, a5, a6, a7;
25 double f1 = 0.0, f2 = 0.0, q = 0.0;
26 for (int i = 0; i < 3; i++) {
27 std::istringstream s(a[i]);
28 if (loc)
29 s.imbue(loc: *loc);
30 s >> a1 >> a2 >> a3 >> f1 >> a4 >> a5 >> f2 >> a6 >> a7;
31 q += (a1 + a2 + a3 + a4 + a5 + a6 + a7 + f1 + f2) / 1000000;
32 }
33 return q;
34}
35
36struct LocaleSelector {
37 std::locale* imbue;
38 std::locale old;
39 static std::mutex mutex;
40
41 LocaleSelector(benchmark::State& state) {
42 std::lock_guard guard(mutex);
43 switch (state.range(0)) {
44 case 0: {
45 old = std::locale::global(loc: std::locale::classic());
46 imbue = nullptr;
47 break;
48 }
49 case 1: {
50 old = std::locale::global(loc: std::locale::classic());
51 thread_local std::locale loc("en_US.UTF-8");
52 imbue = &loc;
53 break;
54 }
55 case 2: {
56 old = std::locale::global(loc: std::locale::classic());
57 static std::locale loc("en_US.UTF-8");
58 imbue = &loc;
59 break;
60 }
61 case 3: {
62 old = std::locale::global(loc: std::locale("en_US.UTF-8"));
63 imbue = nullptr;
64 break;
65 }
66 }
67 }
68
69 ~LocaleSelector() {
70 std::lock_guard guard(mutex);
71 std::locale::global(loc: old);
72 }
73};
74
75std::mutex LocaleSelector::mutex;
76
77static void BM_Istream_numbers(benchmark::State& state) {
78 LocaleSelector sel(state);
79 double i = 0;
80 while (state.KeepRunning())
81 benchmark::DoNotOptimize(i += istream_numbers(sel.imbue));
82}
83BENCHMARK(BM_Istream_numbers)->DenseRange(0, 3)->UseRealTime()->Threads(1)->ThreadPerCpu();
84
85static void BM_Ostream_number(benchmark::State& state) {
86 LocaleSelector sel(state);
87 while (state.KeepRunning()) {
88 std::ostringstream ss;
89 if (sel.imbue)
90 ss.imbue(loc: *sel.imbue);
91 ss << 0;
92 benchmark::DoNotOptimize(ss.str().c_str());
93 }
94}
95BENCHMARK(BM_Ostream_number)->DenseRange(0, 3)->UseRealTime()->Threads(1)->ThreadPerCpu();
96
97BENCHMARK_MAIN();
98

source code of libcxx/test/benchmarks/stringstream.bench.cpp