[llvm-commits] [llvm] r142660 - in /llvm/trunk: lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp test/CodeGen/X86/2011-20-21-zext-ui2fp.ll

[Duncan Sands]

Hi Nadav,

> --- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp (original)
> +++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeVectorTypes.cpp Fri Oct 21 12:35:19 2011
> @@ -787,7 +787,17 @@
>       break;
>     }
>     case TargetLowering::TypePromoteInteger: {
> -    SDValue InOp = GetPromotedInteger(N->getOperand(0));
> +    SDValue InOp;
> +    if (N->getOpcode() == ISD::SIGN_EXTEND ||
> +        N->getOpcode() == ISD::SINT_TO_FP) {
> +      InOp =   SExtPromotedInteger(N->getOperand(0));
> +    } else if (
> +        N->getOpcode() == ISD::ZERO_EXTEND ||
> +        N->getOpcode() == ISD::UINT_TO_FP) {
> +      InOp =   ZExtPromotedInteger(N->getOperand(0));
> +    } else {
> +      InOp = GetPromotedInteger(N->getOperand(0));
> +    }
>       EVT InNVT = EVT::getVectorVT(*DAG.getContext(),
>                                    InOp.getValueType().getVectorElementType(),
>                                    LoVT.getVectorNumElements());

how about deleting the entire switch?  Instead you can just always chop the
input in two using an EXTRACT_SUBVECTOR without trying to play with types or
do anything clever.  The type legalization machinery will take care of
legalizing the operands automatically later.  As far as I can see there is
only one useful bit of logic here: if the input is split (TypeSplitVector) then
you can do a little optimization (and that's all it is - saving some compile
time) by grabbing the split input.  So I suggest you keep that bit and in all
other cases do that same as is currently done in the TypeLegal case.

> @@ -2189,8 +2199,7 @@
>     SDValue CC = DAG.getNode(ISD::EXTRACT_SUBVECTOR, dl,
>                              ResVT, WideSETCC, DAG.getIntPtrConstant(0));
>
> -  // Convert the result mask to the correct kind.
> -  return DAG.getAnyExtOrTrunc(CC, dl, N->getValueType(0));
> +  return PromoteTargetBoolean(CC, N->getValueType(0));

PromoteTargetBoolean doesn't handle the case of truncation.  I don't know if
that can really occur here, but maybe you can teach it to do a trunc if needed
(don't forget to update the descriptive comment, in the header as well as in
LegalizeTypes.cpp).

Ciao, Duncan.