[LLVMdev] SSE Scalar Convert Intrinsics

[David Greene]

On Friday 05 June 2009 15:19, Dan Gohman wrote:

> > Do we need two intrinsics for these scalar converts, one to satisfy
> > the
> > (arguably broken) GCC interface and one to really reflect the
> > operation
> > as specified by the ISA?
>
> That's what's done for most other instructions, unfortunately.
> For cvtsd2si, there's currently no "normal" version in the tree,
> but if you add one, it wouldn't be alone.

Ok.

> One thing we'd like to do at some point is have front-ends lower
> intrinsics for scalar instructions into
> extractelement+op+insertelement, so that we don't need two
> versions of each of the instructions.  Doing this for everything
> will require some work to make sure that the extra insert/extract
> operators don't incur unnecessary copying, but that's also
> something we'd like to do regardless.

So then how does one do a memop intrinsic?  Does it mean we can't
match to the memop versions of instructions?

                             -Dave