xelatihy/cpptest

Collection of test for low-level C++ implementation methods

CppTest: A Collection of C++ tests for low-level implementation

• valuesemantic.cpp compares both speed and peak memory of using purely value semantic and purely reference semantic for large objects. It simulates allocaitons in 3D scenes for path tracing.

     mode    shapes instances  vertices      time      mem1      mem2     check
    value      5000      5000     50000  00:00:04      8617      9873   1.5e+09
   unique      5000      5000     50000  00:00:04      7662      7563   1.5e+09
   shared      5000      5000     50000  00:00:04      7284      7937   1.5e+09
      raw      5000      5000     50000  00:00:04      7536      7826   1.5e+09
    value      5000     25000     50000  00:00:05      8155      8576   7.5e+09
   unique      5000     25000     50000  00:00:05      7682      7681   7.5e+09
   shared      5000     25000     50000  00:00:05      7281      7689   7.5e+09
      raw      5000     25000     50000  00:00:05      7418      7681   7.5e+09
    value     15000     15000     50000  00:00:13     24744     26368   4.5e+09
   unique     15000     15000     50000  00:00:13     24668     25729   4.5e+09
   shared     15000     15000     50000  00:00:13     24688     25473   4.5e+09
      raw     15000     15000     50000  00:00:12     24437     25472   4.5e+09
    value     15000     75000     50000  00:00:16     25211     26122  2.25e+10
   unique     15000     75000     50000  00:00:16     24296     25477  2.25e+10
   shared     15000     75000     50000  00:00:16     24630     25479  2.25e+10
      raw     15000     75000     50000  00:00:15     24550     25475  2.25e+10
  

• streamspeed.cpp compares the speed of C FILE and C++ fstream. Short conclusion is that C streams are just faster. Here are some timing results for a MacBook Pro with SSD and OSX 10.14. See the code to check what the functions do.

  print_data: 00:00:00.142
  write_data: 00:00:00.051
  print_file_directly: 00:00:00.128
  print_stream_directly: 00:00:00.219
  parse_file_directly: 00:00:00.162
  parse_stream_directly: 00:00:00.299
  parse_file_lines: 00:00:00.156
  parse_stream_lines: 00:00:00.352
  parse_file_fast: 00:00:00.071
  parse_stream_fast: 00:00:00.094
  parse_stream_fast1: 00:00:00.120
  read_file_directly: 00:00:00.052
  read_stream_directly: 00:00:00.014