Re: A bit of vector extension documentation

[Daniel Egger <degger at fhm dot edu>]

On Fre, 2001-09-28 at 09:38, Richard Henderson wrote:

> So wrap it in something.

Although being able to hack OO languages like C++ and Java
I prefer C for my daily work and it's not acceptable for
some project to introduce C++ - especially for the sole purpose
of only being compilable with most recent GCC versions and
C++ frontend; though you clearly demonstrate what I would expect
to have in the gcc compilersuite somewhere in a templateized
version for general use.

At the moment I'm using the vector extensions from Motorola for
my Altivec coding and although I understand that it might not
be acceptable to introduce something similar into GCC because
it breaks source compatibility in subtle ways I will keep on
using this special 2.95.3 around to generate scheduled ASM
code which I can easily include in applications.

For the future I'd expect to have something like a heuristic that
figures out that loops are trying to do some operations on MD that
is parallelizable and generate good SIMD code for it when the necessary
switch is flipped; yes, this will break applications when one tries to
run them on unwary processors like -mcpu=i686 breaks for i586 and it
might not be desirable in all places especially on Intel CPU where the
cost for switching between SIMD and normal FPU operation is quite costly
but this is for sure the future. There are already compilers out there
which work exactly like described (was it called VAST?) so it seems not
to be completely impossible.

--
Servus,
       Daniel