[Rd] Mere chat on vectorisation matters

[François Pinard]

Hi to all.  Not so long ago, I wrote:

>Allow me to chat a tiny bit on two vectorisation-related matters, in 
>the context of R.  I'm curious about if the following ideas have ever 
>been considered, and rejected already. [... then, a few words about 
>Duff's device, and operation chaining ...]

As this letter did not generate any reply, I presumed the ideas have not 
be rejected, on the premise that if they have been, someone would have 
been kind enough to tell me :-).  So, today, I went forward and added 
Duff's device within arithmetic.c.

There might have been operational or experimental error, of course, as 
I'm far from mastering R installation matters.  But if there were no 
such error, I'm now reporting, for the record, that Duff's device does 
_not_ yield an interesting speedup.

-- 
François Pinard   http://pinard.progiciels-bpi.ca