source code
/* The Computer Language Benchmarks Game
http://benchmarksgame.alioth.debian.org/
started with Java #2 program (Krause/Whipkey/Bennet/AhnTran/Enotus/Stalcup)
adapted for C# by Jan de Vaan
simplified and optimised to use TPL by Anthony Lloyd
optimized to use Vector<double> by Tanner Gooding
small optimisations by Anthony Lloyd
*/
using System;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;
public class MandelBrot
{
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static unsafe byte GetByte(double* pCrb, double Ciby)
{
var res = 0;
for (var i=0; i<8; i+=2)
{
var vCrbx = Unsafe.Read<Vector<double>>(pCrb+i);
var vCiby = new Vector<double>(Ciby);
var Zr = vCrbx;
var Zi = vCiby;
int b = 0, j = 49;
do
{
var nZr = Zr * Zr - Zi * Zi + vCrbx;
var ZrZi = Zr * Zi;
Zi = ZrZi + ZrZi + vCiby;
Zr = nZr;
var t = Zr * Zr + Zi * Zi;
if (t[0]>4.0) { b|=2; if (b==3) break; }
if (t[1]>4.0) { b|=1; if (b==3) break; }
} while (--j>0);
res = (res << 2) + b;
}
return (byte)(res^-1);
}
public static unsafe void Main(string[] args)
{
var size = args.Length==0 ? 200 : int.Parse(args[0]);
Console.Out.WriteAsync(String.Concat("P4\n",size," ",size,"\n"));
var Crb = new double[size+2];
var lineLength = size >> 3;
var data = new byte[size * lineLength];
fixed (double* pCrb = &Crb[0])
fixed (byte* pdata = &data[0])
{
var value = new Vector<double>(
new double[] {0,1,0,0,0,0,0,0}
);
var invN = new Vector<double>(2.0/size);
var onePtFive = new Vector<double>(1.5);
var step = new Vector<double>(2);
for (var i=0; i<size; i+=2)
{
Unsafe.Write(pCrb+i, value*invN-onePtFive);
value += step;
}
var _Crb = pCrb;
var _pdata = pdata;
Parallel.For(0, size, y =>
{
var Ciby = _Crb[y]+0.5;
for (var x=0; x<lineLength; x++)
{
_pdata[y*lineLength+x] = GetByte(_Crb+x*8, Ciby);
}
});
Console.OpenStandardOutput().Write(data, 0, data.Length);
}
}
}