[Speed] Autoit vs. C

#include <cstdlib>
#include <iostream>


using namespace std;


int main(int argc, char *argv[])
{
    int mytest = 0;
    while (mytest < 1000000) //1000000000
    {
      mytest += 1;
    }

    return EXIT_SUCCESS;
}

int faltung_8bit_grey
(
 const unsigned char *inBuffer,
 unsigned char       *outBuffer,
 const int           width,
 const int           alignedWidth,
 const int           height,
 register int		 *mask,
 int				 size
 )
{
	int i;
	int x, y;
	int relX, relY;
	int relYab;
	register int maskpos;
	int pixel;
	int middlePixel;
	int halfsize = (size/2);
	int letztesPixel = (alignedWidth * (height - 1)) + width - 1;
	int filterSumme = 0;
	int tmp;	


	for(i=0; i<(size*size); i++)
		filterSumme += mask[i];


	if(filterSumme == 0)
		filterSumme = 1;	


	tmp = alignedWidth * halfsize;
	for(y = halfsize; y < (height - halfsize); y++)
	{
		for(x = halfsize; x < (width - halfsize); x++)
		{
			pixel = 0;
			middlePixel = x + tmp;
			maskpos = 0;


			for(relY = -halfsize; relY <= halfsize; relY++)
			{
				relYab = alignedWidth * relY;
				for(relX = -halfsize; relX <= halfsize; relX++, maskpos++)
				{
					pixel += *(inBuffer + middlePixel + relX + relYab) * mask[maskpos];
				}
			}
			pixel /= filterSumme;
			outBuffer[middlePixel] = (pixel < 0) ? 0 : (pixel > MAX_GRAY) ? MAX_GRAY : pixel;
		}
		tmp += alignedWidth;
	}


	return 0;
}

public const int MAX_GRAY = 255;


        private void bStart_Click(object sender, EventArgs e)
        {
            byte[] inImage = new byte[480000];
            byte[] outImage = new byte[480000];
            int[] filterMask = new int[9];
            Stopwatch stopWatch = new Stopwatch();


            stopWatch.Start();
            faltung_8bit_grey(ref inImage, ref outImage, 800, 800, 600, ref filterMask, 3);
            stopWatch.Stop();


            tbSekunden.Text = ((double)stopWatch.ElapsedMilliseconds / 1000) + " Sekunden";
        }


        private int faltung_8bit_grey(
            ref byte[]  inBuffer,
            ref byte[]  outBuffer,
            int         width,
            int         alignedWidth,
            int         height,
            ref int[]   mask,
            int	        size)
        {
            int i;
	    int x, y;
	    int relX, relY;
	    int relYab;
	    int maskpos;
	    int pixel;
	    int middlePixel;
	    int halfsize = (size/2);
	    int lastPixel = (alignedWidth * (height - 1)) + width - 1;
	    int filterSumme = 0;
	    int tmp;


            for (i = 0; i < (size * size); i++)
                filterSumme += mask[i];


            if (filterSumme == 0)
                filterSumme = 1;


            tmp = alignedWidth * halfsize;
            for (y = halfsize; y < (height - halfsize); y++)
            {
                for (x = halfsize; x < (width - halfsize); x++)
                {
                    pixel = 0;
                    middlePixel = x + tmp;
                    maskpos = 0;


                    for (relY = -halfsize; relY <= halfsize; relY++)
                    {
                        relYab = alignedWidth * relY;
                        for (relX = -halfsize; relX <= halfsize; relX++, maskpos++)
                        {
                            pixel += inBuffer[middlePixel + relX + relYab] * mask[maskpos];
                        }
                    }
                    pixel /= filterSumme;
                    outBuffer[middlePixel] = (byte) ((pixel < 0) ? 0 : (pixel > MAX_GRAY) ? MAX_GRAY : pixel);                    
                }
                tmp += alignedWidth;
            }

            return 0;
        }