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Re: Status of SSE builtins
> On Wed, Oct 30, 2002 at 10:41:40PM +0100, Jan Hubicka wrote:
> > We generate instruction dealing with elements of the vector using
> > subregs, like (subreg:HI (reg:V4HI) 2) is expected to access and modify
> > only the second field of the vector. However the subregs gneerally
> > clobber whole word in GCC and are not allowed in such general forms.
>
> Yes, I was talking with Aldy about this recently. He has the
> same problem for Motorola BookE vectors.
>
> I think the proper solution is to have named patterns in the md file
> that the rtl expander will use to satisfy these insertions and extractions.
> If the named patterns do not exist, or FAIL, then we fall back to a
> combination of subreg and insert/extract bitfield.
This sounds good to me, even when the SSE code would be lousy
(to set given QImode of V16QI seems to be dificult). I won't be able to
do this before weekend, but I can take a look.
What names would you propose?
Perhaps extract_vec_fieldM/set_vec_fieldM?
Honza
>
>
> r~