libcxx/benchmarks/stringstream.bench.cpp

   1 #include "benchmark/benchmark.h"
   2 #include "test_macros.h"
   3
   4 #include <sstream>
   5
   6 TEST_NOINLINE double istream_numbers();
   7
   8 double istream_numbers() {
   9   const char* a[] = {"-6  69 -71  2.4882e-02 -100 101 -2.00005 5000000 -50000000",
  10                      "-25 71   7 -9.3262e+01 -100 101 -2.00005 5000000 -50000000",
  11                      "-14 53  46 -6.7026e-02 -100 101 -2.00005 5000000 -50000000"};
  12
  13   int a1, a2, a3, a4, a5, a6, a7;
  14   double f1 = 0.0, f2 = 0.0, q = 0.0;
  15   for (int i = 0; i < 3; i++) {
  16     std::istringstream s(a[i]);
  17     s >> a1 >> a2 >> a3 >> f1 >> a4 >> a5 >> f2 >> a6 >> a7;
  18     q += (a1 + a2 + a3 + a4 + a5 + a6 + a7 + f1 + f2) / 1000000;
  19   }
  20   return q;
  21 }
  22
  23 static void BM_Istream_numbers(benchmark::State& state) {
  24   double i = 0;
  25   while (state.KeepRunning())
  26     benchmark::DoNotOptimize(i += istream_numbers());
  27 }
  28
  29 BENCHMARK(BM_Istream_numbers)->RangeMultiplier(2)->Range(1024, 4096);
  30 BENCHMARK_MAIN();