Re: Ada and vectorization

[Dale Stanbrough <dstanbro@bigpond.net.au>]

Guillaume Foliard wrote:

> Hello,
> 
> I start to learn how to use the Intel's SSE instruction set in Ada programs 
> with inline assembly. And while reading Intel documentation (1) I was 
> asking myself if Ada could provide a clean way of vectorization through its 
> strong-typed approach. Could it be sensible, for the next Ada revision, to 
> create some new attributes for array types to explicitly hint the compiler 
> that we want to use SIMD instructions ?
> Language lawyers comments are definitly welcome. As SIMD in modern general 
> purpose processors is largely available nowadays (SSE, SSE2, Altivec, 
> etc...), IMHO, it would be a mistake for Ada to ignore the performance 
> benefit this could bring.


I think the best way to do this is via pragmas. There is one pragma - 
Annotate - which would be perfect for the job.
I think Annotate is a Gnat only thing - the real work would have
to be done with an ASIS like tool.

Very much like the fortran world, where the structured comments can 
be ignored by ignorant compilers, and the program still behaves
correctly (if not as fast).

Dale