Fib: C++, C# and GDC

As a reference implementation, I added C++ one:


#include "time.h"
int fib(int n){
if (n < 2) return n;
return fib(n - 1) + fib(n - 2);
}
int _tmain(int argc, _TCHAR* argv [])
{
auto begin = clock();
for (int n = 0; n < 40; n++) {
printf("fib (%d) = %d\n", n, fib(n));
}
auto end = clock();
auto elapsed_secs = double(end - begin) / CLOCKS_PER_SEC;
printf("elapsed: %f secs\n", elapsed_secs);
return 0;
}
view raw fib.cpp hosted with ❤ by GitHub
It's execution time is 1.33 seconds, which surprisingly is not the best result so far.
A C# version:

class MainClass {
static int Fib (int n) { return n < 2 ? n : Fib (n - 1) + Fib (n - 2); }
public static void Main (string[] args) {
var w = Stopwatch.StartNew ();
for (var n = 0; n < 40; n++)
Console.WriteLine("fib({0}) = {1}", n, Fib(n));
Console.WriteLine ("{0} elapsed.", w.Elapsed);
Console.ReadKey ();
}
}
view raw fib.cs hosted with ❤ by GitHub
Also, I compiled this D code with GDC compiler and it executed in 990 ms, which is the best result:

  • D (GDC) - 0.990
  • C# - 1.26
  • D (DMD) - 1.3
  • C++ - 1.33
  • F# - 1.38
  • Nemerle - 1.45
  • Rust - 1.66
  • Go - 2.38
  • Haskell - 2.8
  • Clojure - 9
  • Erlang - 17
  • Ruby - 60
  • Python - 120

Unfortunately, I have not managed to compile the D code with LDC compiler, it returns the following error:

Building: DFib (Release)
Performing main compilation...
Current dictionary: d:\git\DFib\DFib
D:\ldc2-0.15.2-beta1-win64-msvc\bin\ldc2.exe -O3 -release "main.d"   "-od=obj\Release" "-of=d:\git\DFib\DFib\bin\Release\DFib.exe"
LINK : fatal error LNK1181: cannot open input file 'kernel32.lib'
Error: C:\Program Files (x86)\Microsoft Visual Studio 12.0\VC\bin\link.exe failed with status: 1181
Exit code 1181

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