[llvm-commits] [llvm] r44676 - in /llvm/trunk: lib/Target/X86/X86ISelLowering.cpp test/CodeGen/X86/2007-12-05-VectorShuffle.ll test/CodeGen/X86/vec_shuffle-12.ll

[Chris Lattner]

Hey Evan,

> +++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Fri Dec  7  
> 02:07:39 2007
> @@ -2754,10 +2754,33 @@
>    }
>
>    std::swap(V1, V2);
> -  Mask = DAG.getNode(ISD::BUILD_VECTOR, MaskVT, &MaskVec[0],  
> MaskVec.size());
> +  Mask = DAG.getNode(ISD::BUILD_VECTOR, MaskVT, &MaskVec[0],  
> NumElems);
>    return DAG.getNode(ISD::VECTOR_SHUFFLE, VT, V1, V2, Mask);
>  }
>
> +static
> +SDOperand CommuteVectorShuffleMask(SDOperand Mask, SelectionDAG  
> &DAG) {

Please add a comment over this that gives an example of what it  
does.  I kept misreading the name as "compute..." and couldn't figure  
out what it did :)

> +static
> +SDOperand LowerVECTOR_SHUFFLEv8i16(SDOperand V1, SDOperand V2,
> +                                   SDOperand PermMask,  
> SelectionDAG &DAG,
> +                                   TargetLowering &TLI) {

Does this cause any pessimizations for v8i16 shuffles that could be  
done as v4i32?

-Chris