[LLVMdev] Selecting Vector Shuffle of Different Types

[Bob Wilson]

On Dec 2, 2009, at 3:46 PM, David Greene wrote:
> Well, it's right!  So how do I express this kind of thing?  Since LLVM 2.5 
> shufflevector supports creating a vector of a difference size than the
> inputs.  Which is exactly what we need for VEXTRACTF128 and VINSERTF128.

I think the SelectionDAG vector_shuffle node still requires the vector types to match.  The LLVM IR shuffles can have a different size, but they are forced to match when building the SelectionDAG.