Re: [Sbcl-devel] optimizing array-in-bounds-p in case of known array dimensions

[Paul K. <pk...@gm...>]

On 29-Dec-08, at 8:40 AM, Knut Franke wrote:
> I.e., using array-in-bounds-p in a tight loop on an array of known  
> dimensions.
> Disassembling #'test shows that it contains a dynamic call to  
> #'array-in-
> bounds-p, that I think can and should be optimized away in this case.

ARRAY-IN-BOUNDS-P is only used by SBCL in an out of line PCL  
function.  The reason ARRAY-IN-BOUNDS-P isn't optimized at all is  
simply that it's not used (internally) by anything that's expected to  
be efficient (e.g. inline array access), and it seems no one yet has  
complained about its performance.  The transformation probably makes  
sense for arrays of small rank, if only to save space, but is there a  
practical reason you want ARRAY-IN-BOUNDS-P to be fast? There might be  
a better way.

Paul Khuong