Validity of SUBREG+AND-imm transformations

[Jeff Law]

On 03/04/2016 08:05 AM, Richard Biener wrote:
>> does that mean that the shift amount should be DImode?
>> Seems like a more flexible approach would be for the midend to be able
>> to handle these things...
>
> Or macroize for all integer modes?
That's probably worth exploring.  I wouldn't be at all surprised if it 
that turns out to be better than any individual mode,  not just for arm 
& aarch64, but would help a variety of targets.

My worry is that such a change will bleeds out beyond just the standard 
shifting and shadd style patterns in each port.  I guess that would 
largely depend on how many combiner patterns a port has which combine a 
shift with some other operation.

jeff