John, In the FFT with unsafe-vector*-ref, etc substituted for unsafe-vector-ref, etc, the run times are up to 100% greater. There may be places I can revert to the unsafe-vector-ref, etc versions, but it would require an analysis of the code that I don't have the time to do at the moment. I guess another alternative is to keep the old behavior using the #:flat keyword on the contracts. Using your test, I had the following on my laptop on 5.0.1
> cpu time: 94 real time: 94 gc time: 0 > cpu time: 79 real time: 78 gc time: 0 > #t On 5.0.1.900 I get the following run times: cpu time: 203 real time: 203 gc time: 0 cpu time: 94 real time: 94 gc time: 0 #t I see similar results on my other tests I'll see what I get with the #:flat keyword next. Doug On Fri, Oct 22, 2010 at 9:31 PM, Doug Williams <m.douglas.willi...@gmail.com > wrote: > Matthew, would it make more sense to have unsafe-vector-ref (and related > functions) be the more general function and unsafe-vector*-ref be the one > that doesn't work on chaperoned vectors? That is just swap the definitions. > That way user code that is already using unsafe-vector-ref (etc) will > continue to work. > > As it stands, existing code that has unsafe-vector-ref (etc) will often > still work (in the sense of not getting any error or crashing), but just > gives the wrong results. For example, if you run science-test.ss from the > examples directory in the science collection, there are no errors. But, some > of the answers are wrong - for example the very first one, the gamma > function. [In other cases, like the FFT routines, there are either run-time > errors or crashes.] > > Anyway, if it isn't too late, I think swapping the definitions would make > more sense and be safer. > > Doug > > On Wed, Oct 20, 2010 at 8:56 AM, Matthew Flatt <mfl...@cs.utah.edu> wrote: > >> 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. >> >> >
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