[15] RFR (M): 8238690: C2: Handle vector shifts by constant and non-constant scalar uniformly

[Tobias Hartmann]

+1

Best regards,
Tobias

On 07.02.20 19:15, Viswanathan, Sandhya wrote:
> Hi Vladimir,
> 
> Your patch looks good to me.
> 
> Best Regards,
> Sandhya
> 
> -----Original Message-----
> From: Vladimir Ivanov <vladimir.x.ivanov at oracle.com> 
> Sent: Friday, February 07, 2020 6:49 AM
> To: hotspot compiler <hotspot-compiler-dev at openjdk.java.net>
> Cc: Viswanathan, Sandhya <sandhya.viswanathan at intel.com>; Bhateja, Jatin <jatin.bhateja at intel.com>
> Subject: [15] RFR (M): 8238690: C2: Handle vector shifts by constant and non-constant scalar uniformly
> 
> http://cr.openjdk.java.net/~vlivanov/8238690/webrev.00/
> https://bugs.openjdk.java.net/browse/JDK-8238690
> 
> Unify IR shape for vector shifts by scalar and always use:
>     ShiftV src (ShiftCntV shift)
> 
> Right now, constant case has a special representation:
>     ShiftV src ConI
> 
> It allows to simplify generic vector logic a bit and get rid of auxilliary chain rule on x86 (vshiftcntimm).
> 
> Testing: tier1-4
> 
> Best regards,
> Vladimir Ivanov
>