Re: [Gcl-devel] arrays

[Vanuxem Grégory]

Le dimanche 04 septembre 2005 à 23:38 -0400, Camm Maguire a écrit :
> Greetings!
> 
> What is '(array nil) suposed to mean?
> 
> I noticed that cmucl has support for 1 2 4 8 16 and 32bit array
> integers.  GCL has 1, 8, 16 and 32 (on 32bit machines).

Is it possible to send a 32 bits static array to cline ?

I have stopped my lapack implementation, since on my 64 bits machine,
arrays of int are array of long (8 bytes), and this will probably not
change in the future.


Cheers,

Greg

> 
> 1) Is there any real benefit to 2 and 4 bit integer types, considering
>    the access overhead vs space tradeoff?
> 2) My understanding is that the simple (signed-byte
>    2^n),(unsigned-byte 2^n) strategy will not pass all Paul's tests,
>    as upgraded-array-element-type must preserve subtypep relationships
>    -- one needs at least (unsigned-byte 2^n-1), etc.
>    I.e. non-negative-char, signed-char, and (optionally) (unsigned
>    char) for each size type.  This is what I've implemented at
>    present, and I'm passing all relevant tests.  I'd obviously like to
>    support the minimum number of types possible, if for no other
>    reason than it slows down subtypep et. al. on (array *).
> 
> Take care,
>