Branch Prediction Benchmarking in D

bp.d

import std.stdio, std.random, core.time;

void main() {
  int data[32768];

  foreach(ref x; data)
    x = uniform(0, 256);

  data.sort;

  ulong sum;
  auto start = TickDuration.currSystemTick();

  for(auto i = 0; i < 100000; ++i)
    foreach(x; data)
      if (x >= 128)
        sum += x;

  writeln("Done in ", (TickDuration.currSystemTick() - start).msecs(), "ms");
  writeln("sum = ", sum);
}

Inspired by this question on StackOverflow:

Compiled with -O -release under dmd 2.057 (Win32) on Intel Core2 6420 @ 2.13GHz

• With sorting: 7367ms
• Without sorting: 20881ms