[racket-dev] Release for v5.0.2 has begun

At Wed, 20 Oct 2010 07:48:20 -0700, John Clements wrote:
> 
> On Oct 20, 2010, at 7:39 AM, Doug Williams wrote:
> 
> > I downloaded the pre-release version this morning - 10/20 (I believe it was 
> a build from 10/16). The plot package and plot extensions in the science 
> collection all work as expected. But, I am getting different numeric answers 
> for some of my science collection routines (for example, the gamma function) 
> and some of my newer code (for example, FFT) either fails with an error 
> message or DrRacket just dies. All of this code uses unsafe operations and the 
> problem may lie there somewhere. I'll try digging more deeply this evening.
> 
> Focus first on uses of unsafe-vector-ref and unsafe-vector-set!. (Not the fx 
> and fl variants, just the plain ones).  I wound up removing these from the FFT 
> code in order to get it to work.  
> 
> Check out bug PR 11264. 
> 
> Also, very late flash of insight: my response (getting rid of 
> unsafe-vector-ref and unsafe-vector-set!) might explain my performance issues 
> with the FFT library.

Overall, keep in mind that changes to vector contracts mean that
vectors can be wrapped with chaperones. That's why `unsafe-vector-ref'
may need to change to `unsafe-vector*-ref', and it may explain
performance differences in general.