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[] = {
  10     "-6  69 -71  2.4882e-02 -100 101 -2.00005 5000000 -50000000",
  11     "-25 71   7 -9.3262e+01 -100 101 -2.00005 5000000 -50000000",
  12     "-14 53  46 -6.7026e-02 -100 101 -2.00005 5000000 -50000000"
  13   };
  14
  15   int a1, a2, a3, a4, a5, a6, a7;
  16   double f1 = 0.0, f2 = 0.0, q = 0.0;
  17   for (int i=0; i < 3; i++) {
  18     std::istringstream s(a[i]);
  19     s >> a1
  20       >> a2
  21       >> a3
  22       >> f1
  23       >> a4
  24       >> a5
  25       >> f2
  26       >> a6
  27       >> a7;
  28     q += (a1 + a2 + a3 + a4 + a5 + a6 + a7 + f1 + f2)/1000000;
  29   }
  30   return q;
  31 }
  32
  33 static void BM_Istream_numbers(benchmark::State &state) {
  34   double i = 0;
  35   while (state.KeepRunning())
  36     benchmark::DoNotOptimize(i += istream_numbers());
  37 }
  38
  39 BENCHMARK(BM_Istream_numbers)->RangeMultiplier(2)->Range(1024, 4096);
  40 BENCHMARK_MAIN();