[racket-dev] [plt] Push #28281: master branch updated

At Mon, 3 Mar 2014 08:35:42 -0500, Sam Tobin-Hochstadt wrote:
> A few questions about this:
> 
> 1. Why not keep the 7x faster version as the fallback?

I expect the fallback to be almost never used, and so it would be lots
of `unsafe-...` calls to worry about with almost no benefit.

> 2. How much of the performance difference is 31/63-bit integers vs the
> C code using 32/64 bit?

My guesses (for 64-bit Racket): About half, where the other half is
poor use of registers by the JIT.

> 3. I think you could have used `define-inline` from
> `racket/performance-hint` here.

Yes, but it pulls in more dependencies than I wanted here.


> On Mon, Mar 3, 2014 at 7:55 AM,  <mflatt at racket-lang.org> wrote:
> >
> > ~~~~~~~~~~
> >
> > 7e546d1 Matthew Flatt <mflatt at racket-lang.org> 2014-03-02 17:46
> > :
> > | file/md5: faster
> > |
> > | Use unsafe operations and forced inlining to speed up
> > | MD5 calculation by about x2.25 on 32-bit platforms, and
> > | use all that plus fixnums to speed up by about x7 on
> > | 64-bit platforms.
> > |
> > | This implementation is still about a factor of 5 off
> > | a C implementation. So, while this was a fun little
> > | experiment, I'll revert this commit and add a binding
> > | to the OpenSSL MD5 implementation, instead.
> > :
> >   M racket/collects/file/md5.rkt | 520 
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