[PATCH] fix PR15296

[Michael Liao]

Hi Nadav

On Wed, 2013-02-20 at 09:27 -0800, Nadav Rotem wrote:
> Patch #1:
> 
> +SDValue X86TargetLowering::LowerShift(SDValue Op, SelectionDAG &DAG) const {
> +
> +  EVT VT = Op.getValueType();
> 
> No need for extra space. 

Will fix that.

> 
> Patch #2: 
> 
> Please write a few cost-model tests to make sure that we get the costs of the shifts right. 

Sure.

> 
> Patch #3:
> 
> In this patch you are doing two things. 1. Move code from x86combine to x86lower, and add a new optimization. Please split this into two patches.

The patch is mostly moving. The code added otherwise to handle 64-bit
shift in 32-bit mode as DAG combining won't see the extended 64-bit
type. Unless we disable some test cases, splitting this patch will break
builds.

- michael

> 
> Thanks,
> Nadav  
> 
>