[Beignet] [PATCH newRT] Add cl_gen_device_common.h file.

[Song, Ruiling]

> -----Original Message-----
> From: Rebecca N. Palmer [mailto:rebecca_palmer at zoho.com]
> Sent: Friday, April 7, 2017 2:50 PM
> To: Song, Ruiling <ruiling.song at intel.com>; beignet at lists.freedesktop.org
> Subject: Re: [Beignet] [PATCH newRT] Add cl_gen_device_common.h file.
> 
> > I think a better choice is to make OpenCL 1.2 also use 64bit address. So that
> we have a unified address_bits across 1.2 and 2.0.
> > But using 64bit address would hurt some performance. I think we need more
> work on 64bit optimization to make "unified address_bits across different ocl
> version" affect as less as we can.
> 
> Will that break older hardware (no emitUntypedReadA64Instruction) like
> unconditionally enabling OpenCL 2.0 does, or is this only intended to
> apply to 2.0-capable hardware?
Older platform IVB/HSW should still use 32bit address bits. I forgot this:(
For 2.0 capable hardware, we can switch to 64bit address bits after 64bit operations will not hurt too much performance.
Sounds that it's better to leave it as it is now because we don't differentiate it for different hardware.

Thanks!
Ruiling