🚀 go-pugleaf

In article <1992Aug10.221247.8016@cfa.harvard.edu> alberto@cfa.harvard.edu (Alberto Accomazzi) writes:

> A far as making the loop tight and fast, if you are only accessing your data
> in a sequential way, the best thing to do is increment the pointer as in:
> 
> function (DATATYPE *data, int xsize, int ysize)
> {
>   int x, y;
>   DATATYPE *dp;
> 
>   dp = data;
>   for (y = 0; y < ysize; y++)
>     for (x = 0; x < xsize; x++, dp++)
>       *dp = ...
> }
> 
> Inner loops can be written in a similar fashion.  As far as I know, this
> will be as fast as you can get.

Actually, you can get just a smidgin faster on most machines:

  dp = data;
  for (y = 0; y < ysize; y++)
    for (x = 0; x < xsize; x++)
      *dp++ = ...
}

but this is probably even less readable than the other examples
posted.


--
 Dr Adrian F. Clark                                   JANET: alien@uk.ac.essex
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 Dept ESE, University of Essex, Wivenhoe Park, Colchester, Essex, C04 3SQ, UK.