[llvm-commits] [PATCH] Allow targets to prefer vector splitting over integer promotion

[Duncan Sands]

On 29/11/12 14:51, Justin Holewinski wrote:
> I'm not sure how to test this in the general case, so I've merged this with the
> hook implementation in NVPTX and its associated test case.  Is this sufficient?

I think it's OK.  One comment:

+  return VT.isSimple() && VT.getSimpleVT() == MVT::i1;

I think you can directly do: return VT == MVT::i1;

Ciao, Duncan.

>
>
> On Thu, Nov 29, 2012 at 8:08 AM, Duncan Sands <baldrick at free.fr
> <mailto:baldrick at free.fr>> wrote:
>
>     On 29/11/12 14:01, Justin Holewinski wrote:
>
>         The attached patch adds a new back-end hook that allows targets to
>         prefer vector
>         splitting over integer promotion for type legalization.  Right now,
>         TargetLowering::__computeRegisterProperties() will first try to promote
>         <N x iM>
>         to <N x iP> where P > M if <N x iM> is illegal.  However, for some
>         targets, it
>         is desirable to instead prefer splitting the vector.
>
>         The in-tree use case is the NVPTX back-end.  <N x i1> is not a legal
>         type, but
>         promotion to <N x i8> or <N x i32> is not desirable.  Instead, we want
>         to force
>         scalarization of vector code using these types (e.g. vselect).
>
>
>     This looks pretty reasonable to me.  However it needs a testcase.
>
>     Ciao, Duncan.
>
>
>
>         --
>
>         Thanks,
>
>         Justin Holewinski
>
>
>
>         _________________________________________________
>         llvm-commits mailing list
>         llvm-commits at cs.uiuc.edu <mailto:llvm-commits at cs.uiuc.edu>
>         http://lists.cs.uiuc.edu/__mailman/listinfo/llvm-commits
>         <http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits>
>
>
>     _________________________________________________
>     llvm-commits mailing list
>     llvm-commits at cs.uiuc.edu <mailto:llvm-commits at cs.uiuc.edu>
>     http://lists.cs.uiuc.edu/__mailman/listinfo/llvm-commits
>     <http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits>
>
>
>
>
> --
>
> Thanks,
>
> Justin Holewinski
>